Variability of back carbon in Northwest Greenland during the past 350 years

NASA Astrophysics Data System (ADS)

Goto-Azuma, Kumiko; Ogawa-Tsukagawa, Yoshimi; Kondo, Yutaka; Dallmayr, Remi; Hirabayashi, Motohiro; Ogata, Jun; Kitamura, Kyotaro; Kawamura, Kenji; Motoyama, Hideaki; Matoba, Sumito; Aoki, Teruo; Moteki, Nobuhiro; Ohata, Sho; Mori, Tatsuhiro; Koike, Makoto; Komuro, Yuki; Tsushima, Akane; Nagatsuka, Naoko

2017-04-01

An ice core to the depth of 225 m was drilled at the SIGMA-D site, Northwest Greenland, in 2014 under the SIGMA (Snow Impurity and Glacial Microbe Effects on Abrupt Warming in the Arctic) project (Matoba et al., 2015). The ice core was analyzed to the depth of 113 m with a Continuous Flow Analysis (CFA) system, which was recently built at the National Institute of Polar Research, Japan. The CFA system allowed high resolution analyses of black carbon (BC), stable isotopes of water, microparticles, electric conductivity, and trace elements (Na, K, Mg, Ca, Fe, and Al). BC was analyzed with a Wide Range SP2, which was recently developed by University of Tokyo (Mori et al., 2016). The Wide Range SP2 enabled us to measure BC particles with the size range between 40 and 4000 nm. Here we report the variability of BC concentrations and size distributions during the past 350 years. Anthropogenic impacts on concentrations, size distributions, and their seasonal variations were clearly seen during the first half of the 20th Century. References Matoba, S., H. Motoyama, K. Fujita. T. Yamasaki, M. Minowa, Y. Onuma Y. Komuro, T. Aoki, S. Yamaguchi, S. Sugiyama and H. Enomoto, Glaciological and meteorological observations at the SIGMA-D site, northwestern Greenland Ice Sheet. Bulletin of Glaciological Research 33, 7-10, 2015. Mori, T., N. Moteki, S. Ohata, M. Koike, K. Goto-Azuma, Y. Miyazaki and Y. Kondo, Improved technique for measuring the size distribution of black carbon particles in liquid water, Aerosol Science & Technology, 50, 3, 242-254, DOI: 10.1080/02786826.2016.1147644, 2016.

Vertical profiles of black carbon concentration and particle number size distribution in the North China Plain

NASA Astrophysics Data System (ADS)

Ran, L.; Deng, Z.

2013-12-01

The vertical distribution of aerosols is of great importance to our understanding in the impacts of aerosols on radiation balance and climate, as well as air quality and public health. To better understand and estimate the effects of atmospheric components including trace gases and aerosols on atmospheric environment and climate, an intensive field campaign, Vertical Observations of trace Gases and Aerosols in the North China Plain (VOGA-NCP), was carried out from late July to early August 2013 over a rural site in the polluted NCP. During the campaign, vertical profiles of black carbon (BC) concentration and particle number size distribution were measured respectively by a micro-Aethalometer and an optical particle counter attached to a tethered balloon within 1000 m height. Meteorological parameters, including temperature, relative humidity, wind speed and wind direction, were measured simultaneously by a radiosonde also attached to the tethered balloon. Preliminary results showed distinct diurnal variations of the vertical distribution of aerosol total number concentration and BC concentration, following the development of the mixing layer. Generally, there was a well mixing of aerosols within the mixing layer and a sharp decrease above the mixing layer. Particularly, a small peak of BC concentrations was observed around 400-500 m height for several profiles. Further analysis would be needed to explain such phenomenon. It was also found that measured vertical profiles of BC using the filter-based method might be affected by the vertical distribution of relative humidity.

Black Carbon Particle Number Distribution Measurements during the ATHENS-2013 Winter Campaign

NASA Astrophysics Data System (ADS)

Gkatzelis, Georgios; Papanastasiou, Dimitris; Florou, Kalliopi; Kaltsonoudis, Christos; Louvaris, Eyaggelos; Bezentakos, Spiridon; Biskos, Georgios; Pandis, Spuros

2014-05-01

Black Carbon (BC) particles emitted by anthropogenic sources play an important role both in climate change and in air quality degradation. Open burning in forests and savannas, combustion of diesel and solid fuels for cooking and heating in homes represent the majority of BC emissions. Earlier work has focused on the BC atmospheric direct radiative forcing that is mostly related to its mass concentration and optical properties of the corresponding particles. A variety of measurement techniques are used to measure the mass concentration of BC by taking advantage of its optical or physical properties. Moreover, the carbonaceous particles containing BC are also important for the indirect forcing of climate. This effect is mostly related to the number concentration of BC particles. The number distribution of BC particles especially below 100 nm is quite uncertain due to limitations of the existing measurement techniques. In this work we employed a thermodenuder-based method as an approach for the measurement of the BC number distribution. More specifically, we combined a thermodenuder (TD) operating at temperatures up to 300 ° C, with a Scanning Mobility Particle Sizer (SMPS) and a High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF AMS). Aerosol size and composition measurements were carried out both at ambient and at elevated TD temperatures in Athens field campaign during January and February of 2013. In parallel, a Multi-Angle Absorption Photometer (MAAP) provided information about the BC mass concentration while a Hygroscopic Tandem Differential Mobility Analyzer (HTDMA) measured the mixing state and the hygroscopicity of the particles as a function of their size. These measurements were then combined to estimate the number concentration of BC particles. Our analysis focused on different periods during the study. During some of them one source dominated the carbonaceous aerosol concentration. Such periods included rush hour traffic, nighttime wood burning, clean air transported from other areas, mixed sources, etc. The number fraction remaining after heating at 300 ° C for approximately 15 s during wood burning events was 80-90%, suggesting that practically all particles contained nonvolatile material. Combining the SMPS, MAAP, AMS, and HTDMA measurements we show that most of the sampled material was BC. On the contrary, during rush hour traffic the number fraction remaining was only 50-60% suggesting that more than half of the particles did not contain BC.

Preliminary Estimation of Black Carbon Deposition from Nepal Climate Observatory-Pyramid Data and Its Possible Impact on Snow Albedo Changes Over Himalayan Glaciers During the Pre-Monsoon Season

NASA Technical Reports Server (NTRS)

Yasunari, T. J.; Bonasoni, P.; Laj, P.; Fujita, K.; Vuillermoz, E.; Marinoni, A.; Cristofanelli, P.; Duchi, R.; Tartari, G.; Lau, K.-M.

2010-01-01

The possible minimal range of reduction in snow surface albedo due to dry deposition of black carbon (BC) in the pre-monsoon period (March-May) was estimated as a lower bound together with the estimation of its accuracy, based on atmospheric observations at the Nepal Climate Observatory-Pyramid (NCO-P) sited at 5079 m a.s.l. in the Himalayan region. We estimated a total BC deposition rate of 2.89 g m-2 day-1 providing a total deposition of 266 micrograms/ square m for March-May at the site, based on a calculation with a minimal deposition velocity of 1.0 10(exp -4) m/s with atmospheric data of equivalent BC concentration. Main BC size at NCO-P site was determined as 103.1-669.8 nm by correlation analysis between equivalent BC concentration and particulate size distribution in the atmosphere. We also estimated BC deposition from the size distribution data and found that 8.7% of the estimated dry deposition corresponds to the estimated BC deposition from equivalent BC concentration data. If all the BC is deposited uniformly on the top 2-cm pure snow, the corresponding BC concentration is 26.0-68.2 microgram/kg assuming snow density variations of 195-512 kg/ cubic m of Yala Glacier close to NCO-P site. Such a concentration of BC in snow could result in 2.0-5.2% albedo reductions. From a simple numerical calculations and if assuming these albedo reductions continue throughout the year, this would lead to a runoff increases of 70-204 mm of water drainage equivalent of 11.6-33.9% of the annual discharge of a typical Tibetan glacier. Our estimates of BC concentration in snow surface for pre-monsoon season can be considered comparable to those at similar altitude in the Himalayan region, where glaciers and perpetual snow region starts in the vicinity of NCO-P. Our estimates from only BC are likely to represent a lower bound for snow albedo reductions, since a fixed slower deposition velocity was used and atmospheric wind and turbulence effects, snow aging, dust deposition, and snow albedo feedbacks were not considered. This study represents the first investigation about BC deposition on snow from atmospheric aerosol data in Himalayas and related albedo effect is especially the first track at the southern slope of Himalayas.

Emissions of Black Carbon, Organic, and Inorganic Aerosols From Biomass Burning in North America and Asia in 2008

NASA Technical Reports Server (NTRS)

Kondo, Y.; Matsui, H.; Moteki, N.; Sahu, L.; Takegawa, N.; Kajino, M.; Zhao, Y.; Cubison, M. J.; Jimenez, J. L.; Vay, S.;

Global direct radiative forcing by process-parameterized aerosol optical properties

NASA Astrophysics Data System (ADS)

KirkevâG, Alf; Iversen, Trond

2002-10-01

A parameterization of aerosol optical parameters is developed and implemented in an extended version of the community climate model version 3.2 (CCM3) of the U.S. National Center for Atmospheric Research. Direct radiative forcing (DRF) by monthly averaged calculated concentrations of non-sea-salt sulfate and black carbon (BC) is estimated. Inputs are production-specific BC and sulfate from [2002] and background aerosol size distribution and composition. The scheme interpolates between tabulated values to obtain the aerosol single scattering albedo, asymmetry factor, extinction coefficient, and specific extinction coefficient. The tables are constructed by full calculations of optical properties for an array of aerosol input values, for which size-distributed aerosol properties are estimated from theory for condensation and Brownian coagulation, assumed distribution of cloud-droplet residuals from aqueous phase oxidation, and prescribed properties of the background aerosols. Humidity swelling is estimated from the Köhler equation, and Mie calculations finally yield spectrally resolved aerosol optical parameters for 13 solar bands. The scheme is shown to give excellent agreement with nonparameterized DRF calculations for a wide range of situations. Using IPCC emission scenarios for the years 2000 and 2100, calculations with an atmospheric global cliamte model (AFCM) yield a global net anthropogenic DRF of -0.11 and 0.11 W m-2, respectively, when 90% of BC from biomass burning is assumed anthropogenic. In the 2000 scenario, the individual DRF due to sulfate and BC has separately been estimated to -0.29 and 0.19 W m-2, respectively. Our estimates of DRF by BC per BC mass burden are lower than earlier published estimates. Some sensitivity tests are included to investigate to what extent uncertain assumptions may influence these results.

Characteristics of Ambient Black Carbon Mass and Size-Resolved Particle Number Concentrations during Corn Straw Open-Field Burning Episode Observations at a Rural Site in Southern Taiwan.

PubMed

Cheng, Yu-Hsiang; Yang, Li-Sing

2016-07-08

Information on the effect of open-field burning of agricultural residues on ambient black carbon (BC) mass and size-resolved particle number concentrations is scarce. In this study, to understand the effect of such open-field burning on short-term air quality, real-time variations of the BC mass and size-resolved particle number concentrations were monitored before and during a corn straw open-field burning episode at a rural site. Correlations between the BC mass and size-resolved particle number concentrations during the episode were investigated. Moreover, the particle number size distribution and absorption Ångström exponent were determined for obtaining the characteristics of aerosol emissions from the corn straw open-field burning. The results can be used to address public health concerns and as a reference for managing similar episodes of open-field burning of agricultural residues.

Diurnal variations of aerosol characteristics at a rural measuring site close to the Ruhr-Area, Germany

NASA Astrophysics Data System (ADS)

Kuhlbusch, T. A. J.; John, A. C.; Fissan, H.

PM10, PM2.5, and Black Carbon (BC) mass concentrations as well as number size distributions were measured quasi-online at a rural sampling site from 18 September to 17 October 1997. Average PM10, PM2.5, and BC mass concentrations were 37 ± 25, 25 ± 23, and 2 ± 1 μgm -3, respectively. All determined aerosol characteristics showed significant diurnal variations with generally higher concentrations during daytime compared to nights. Maxima in mass concentrations were around 11 AM and 8 PM during weekdays, most likely caused by commuter traffic. Decreased mass concentrations, changes in chemical composition and size distribution have been observed for the time from 12 to 5 PM. Diurnal variations of the BC/PM2.5 mass ratio revealed a minimum between 12 and 4 PM. The ratio of particle volume (0.5-2.5 μm) to particle mass (PM2.5) called 'potential density' also showed significant diurnal changes. These changes could be attributed to increasing in mixing height and windspeed. The determined diurnal variations in particle mass, composition, and size distribution may be relevant for epidemiological studies. We propose that diurnally weighted averages of relevant aerosol characteristics, which take diurnal patterns of human activities into account, should be used in epidemiological studies.

Microphysics-based black carbon aging in a global CTM: constraints from HIPPO observations and implications for global black carbon budget

NASA Astrophysics Data System (ADS)

He, Cenlin; Li, Qinbin; Liou, Kuo-Nan; Qi, Ling; Tao, Shu; Schwarz, Joshua P.

2016-03-01

We develop and examine a microphysics-based black carbon (BC) aerosol aging scheme that accounts for condensation, coagulation, and heterogeneous chemical oxidation processes in a global 3-D chemical transport model (GEOS-Chem) by interpreting the BC measurements from the HIAPER Pole-to-Pole Observations (HIPPO, 2009-2011) using the model. We convert aerosol mass in the model to number concentration by assuming lognormal aerosol size distributions and compute the microphysical BC aging rate (excluding chemical oxidation aging) explicitly from the condensation of soluble materials onto hydrophobic BC and the coagulation between hydrophobic BC and preexisting soluble particles. The chemical oxidation aging is tested in the sensitivity simulation. The microphysical aging rate is ˜ 4 times higher in the lower troposphere over source regions than that from a fixed aging scheme with an e-folding time of 1.2 days. The higher aging rate reflects the large emissions of sulfate-nitrate and secondary organic aerosol precursors hence faster BC aging through condensation and coagulation. In contrast, the microphysical aging is more than 5-fold slower than the fixed aging in remote regions, where condensation and coagulation are weak. Globally, BC microphysical aging is dominated by condensation, while coagulation contribution is largest over eastern China, India, and central Africa. The fixed aging scheme results in an overestimate of HIPPO BC throughout the troposphere by a factor of 6 on average. The microphysical scheme reduces this discrepancy by a factor of ˜ 3, particularly in the middle and upper troposphere. It also leads to a 3-fold reduction in model bias in the latitudinal BC column burden averaged along the HIPPO flight tracks, with largest improvements in the tropics. The resulting global annual mean BC lifetime is 4.2 days and BC burden is 0.25 mg m-2, with 7.3 % of the burden at high altitudes (above 5 km). Wet scavenging accounts for 80.3 % of global BC deposition. We find that, in source regions, the microphysical aging rate is insensitive to aerosol size distribution, condensation threshold, and chemical oxidation aging, while it is the opposite in remote regions, where the aging rate is orders of magnitude smaller. As a result, global BC burden and lifetime show little sensitivity (< 5 % change) to these three factors.

Microphysics-based black carbon aging in a global CTM: constraints from HIPPO observations and implications for global black carbon budget

NASA Astrophysics Data System (ADS)

He, C.; Li, Q.; Liou, K. N.; Qi, L.; Tao, S.; Schwarz, J. P.

2015-11-01

We develop and examine a microphysics-based black carbon (BC) aerosol aging scheme that accounts for condensation and coagulation processes in a global 3-D chemical transport model (GEOS-Chem) by interpreting the BC measurements from the HIAPER Pole-to-Pole Observations (HIPPO, 2009-2011) using the model. We convert aerosol mass in the model to number concentration by assuming lognormal aerosol size distributions and compute the microphysical BC aging rate explicitly from the condensation of soluble materials onto hydrophobic BC and the coagulation between hydrophobic BC and preexisting soluble particles. The resulting aging rate is ∼ 4 times higher in the lower troposphere over source regions than that from a fixed aging scheme with an e-folding time of 1.2 days. The higher aging rate reflects the large emissions of sulfate-nitrate and secondary organic aerosol precursors hence faster BC aging through condensation and coagulation. In contrast, the microphysical aging is more than fivefold slower than the fixed aging in remote regions, where condensation and coagulation are weak. Globally BC microphysical aging is dominated by condensation, while coagulation contribution is largest over East China, India, and Central Africa. The fixed aging scheme results in an overestimate of HIPPO BC throughout the troposphere by a factor of 6 on average. The microphysical scheme reduces this discrepancy by a factor of ∼ 3, particularly in the middle and upper troposphere. It also leads to a threefold reduction in model bias in the latitudinal BC column burden averaged along the HIPPO flight tracks, with largest improvements in the tropics. The resulting global annual mean BC lifetime is 4.2 days and BC burden is 0.25 mg m-2, with 7.3 % of the burden at high altitudes (above 5 km). Wet scavenging accounts for 80.3 % of global BC deposition. We find that in source regions the microphysical aging rate is insensitive to aerosol size distribution, condensation threshold, and chemical oxidation aging, while it is the opposite in remote regions, where the aging rate is orders of magnitude smaller. As a result, global BC burden and lifetime show little sensitivity (< 5 % change) to these three factors.

Black carbon aerosol characterization in a remote area of Qinghai-Tibetan Plateau, western China.

PubMed

Wang, Qiyuan; Schwarz, J P; Cao, Junji; Gao, Rushan; Fahey, D W; Hu, Tafeng; Huang, R-J; Han, Yongming; Shen, Zhenxing

2014-05-01

The concentrations, size distributions, and mixing states of refractory black carbon (rBC) aerosols were measured with a ground-based Single Particle Soot Photometer (SP2), and aerosol absorption was measured with an Aethalometer at Qinghai Lake (QHL), a rural area in the Northeastern Tibetan Plateau of China in October 2011. The area was not pristine, with an average rBC mass concentration of 0.36 μg STP-m(-3) during the two-week campaign period. The rBC concentration peaked at night and reached the minimal in the afternoon. This diurnal cycle of concentration is negatively correlated with the mixed layer depth and ventilation. When air masses from the west of QHL were sampled in late afternoon to early evening, the average rBC concentration of 0.21 μg STP-m(-3) was observed, representing the rBC level in a larger Tibetan Plateau region because of the highest mixed layer depth. A lognormal primary mode with mass median diameter (MMD) of ~175 nm, and a small secondary lognormal mode with MMD of 470-500 nm of rBC were observed. Relative reduction in the secondary mode during a snow event supports recent work that suggested size dependent removal of rBC by precipitation. About 50% of the observed rBC cores were identified as thickly coated by non-BC material. A comparison of the Aethalometer and SP2 measurements suggests that non-BC species significantly affect the Aethalometer measurements in this region. A scaling factor for the Aethalometer data at a wavelength of 880 nm is therefore calculated based on the measurements, which may be used to correct other Aethalometer datasets collected in this region for a more accurate estimate of the rBC loading. The results present here significantly improve our understanding of the characteristics of rBC aerosol in the less studied Tibetan Plateau region and further highlight the size dependent removal of BC via precipitation. Copyright © 2014 Elsevier B.V. All rights reserved.

Arctic Black Carbon Loading and Profile Using the Single-Particle Soot Photometer (SP2) Field Campaign Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sedlacek, Arthur J

One of the major issues confronting aerosol climate simulations of the Arctic and Antarctic cryospheres is the lack of detailed data on the vertical and spatial distribution of aerosols with which to test these models. This is due, in part, to the inherent difficulty of conducting such measurements in extreme environments. However given the pronounced sensitivity of the polar regions to radiative balance perturbations, it is incumbent upon our community to better understand and quantify these perturbations, and their unique feedbacks, so that robust model predictions of this region can be realized. One class of under-measured radiative forcing agents inmore » the polar region is the absorbing aerosol—black carbon and brown carbon. Black carbon (BC; also referred to as light-absorbing carbon [LAC], refractory black carbon [rBC], and soot) is second only to CO2 as a positive forcing agent. Roughly 60% of BC emissions can be attributed to anthropogenic sources (fossil fuel combustion and open-pit cooking), with the remaining fraction being due to biomass burning. Brown carbon (BrC), a major component of biomass burning, collectively refers to non-BC carbonaceous aerosols that typically possess minimal light absorption at visible wavelengths but exhibit pronounced light absorption in the near-ultraviolet (UV) spectrum. Both species can be sourced locally or be remotely transported to the Arctic region and are expected to perturb the radiative balance. The work conducted in this field campaign addresses one of the more glaring deficiencies currently limiting improved quantification of the impact of BC radiative forcing in the cryosphere: the paucity of data on the vertical and spatial distributions of BC. By expanding the Gulfstream aircraft (G-1) payload for the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility-sponsored ACME-V campaign to include the Single-Particle Soot Photometer (SP2)) and leveraging the ACME-V campaign’s deployment within the Arctic Circle during the summer of 2015 (Deadhorse, Alaska [70° 12' 20" N, 148° 30' 42" W]), the truly unique opportunity presented itself to acquire profile data on BC loading at little additional cost. Since the SP2 is a particle-resolved measurement, the resulting data set provides refractory black carbon (rBC) mass loadings, size and mass distributions, and rBC-containing particle mixing state, all of which are expected to readily find value in the modeling community. As part of the ACME-V (http://www.arm.gov/campaigns/aaf2014armacmev) campaign, CO, CO2, and CH4 were also measured, providing the unique opportunity for carbon closure. We will also work closely with modelers who require such data and expect this collaboration will lead directly to a better understanding of the climate impacts of BC in the Arctic. The primary measurement objective was to acquire airborne data on the vertical and spatial distributions of refractory black carbon (rBC) loading, size and mass distribution, and particle mixing state. The primary scientific objective was to provide a targeted data set of rBC particle distributions to better understand and constrain the impact of black carbon radiative forcing in the cryosphere. The SP2-based data set during this campaign is available in the DOE-ARM archive (http://www.arm.gov/campaigns/aaf2015abclp).« less

Distribution, Sources, and Association of Polycyclic Aromatic Hydrocarbons, Black Carbon, and Total Organic Carbon in Size-Segregated Soil Samples Along a Background–Urban–Rural Transect

PubMed Central

Ray, Sharmila; Khillare, Pandit Sudan; Kim, Ki-Hyun; Brown, Richard J.C.

2012-01-01

Abstract Soil samples were collected over a year-long period along a background–urban–rural transect in Delhi, India for the analysis of polycyclic aromatic hydrocarbons (PAHs), black carbon (BC), and total organic carbon (TOC) in five grain size fractions, x, in μm of 0≤x<53 (I), 53≤x<250 (II), 250≤x<500 (III), 500≤x<2000 (IV), and their sum (total: T). Maximum concentrations of PAH, BC, and TOC were observed in the smallest fraction (I) comprising silt and clay, irrespective of site or season. Results of the molecular diagnostic ratios and principal component analysis (PCA) identified coal, wood, biomass burning, and vehicular emissions as major sources of PAHs at all the three sites, while BC/TOC ratios pointed toward biomass combustion as the chief source of carbonaceous species. This work presents the first such rural-urban transect study considering PAH, BC, and TOC in soil. PMID:23133309

Development of an aerosol microphysical module: Aerosol Two-dimensional bin module for foRmation and Aging Simulation (ATRAS)

NASA Astrophysics Data System (ADS)

Matsui, H.; Koike, M.; Kondo, Y.; Fast, J. D.; Takigawa, M.

2014-09-01

Number concentrations, size distributions, and mixing states of aerosols are essential parameters for accurate estimations of aerosol direct and indirect effects. In this study, we develop an aerosol module, designated the Aerosol Two-dimensional bin module for foRmation and Aging Simulation (ATRAS), that can explicitly represent these parameters by considering new particle formation (NPF), black carbon (BC) aging, and secondary organic aerosol (SOA) processes. A two-dimensional bin representation is used for particles with dry diameters from 40 nm to 10 μm to resolve both aerosol sizes (12 bins) and BC mixing states (10 bins) for a total of 120 bins. The particles with diameters between 1 and 40 nm are resolved using additional eight size bins to calculate NPF. The ATRAS module is implemented in the WRF-Chem model and applied to examine the sensitivity of simulated mass, number, size distributions, and optical and radiative parameters of aerosols to NPF, BC aging, and SOA processes over East Asia during the spring of 2009. The BC absorption enhancement by coating materials is about 50% over East Asia during the spring, and the contribution of SOA processes to the absorption enhancement is estimated to be 10-20% over northern East Asia and 20-35% over southern East Asia. A clear north-south contrast is also found between the impacts of NPF and SOA processes on cloud condensation nuclei (CCN) concentrations: NPF increases CCN concentrations at higher supersaturations (smaller particles) over northern East Asia, whereas SOA increases CCN concentrations at lower supersaturations (larger particles) over southern East Asia. The application of ATRAS in East Asia also shows that the impact of each process on each optical and radiative parameter depends strongly on the process and the parameter in question. The module can be used in the future as a benchmark model to evaluate the accuracy of simpler aerosol models and examine interactions between NPF, BC aging, and SOA processes under different meteorological conditions and emissions.

Aerosol optical properties at a coastal site in Hong Kong, South China: temporal features, size dependencies and source analysis

NASA Astrophysics Data System (ADS)

Wang, Jiaping; Ding, Aijun; Virkkula, Aki; Lee, Shuncheng; Shen, Yicheng; Chi, Xuguang; Xu, Zheng

2016-04-01

Hong Kong is a typical coastal city adjacent to the Pearl River Delta (PRD) region in southern China, which is one of the regions suffering from severe air pollution. Atmospheric aerosols can affect the earth's radiative balance by scattering and absorbing incoming solar radiation. Black Carbon (BC) aerosol is a particularly emphasized component due to its strong light absorption. Aerosol transported from different source areas consists of distinct size distributions, leading to different optical properties. As the byproducts of the incomplete oxidation, BC and CO both have relatively long life time, their relationship is a good indicator for distinguishing different pollutant sources. In this study, temporal variations of aerosol optical properties and concentrations of BC and CO at a coastal background station in Hong Kong were investigated. Transport characteristics and origins of aerosol were elucidated by analyzing backward Lagrangian particle dispersion modeling (LPDM) results, together with related parameters including the relationships between optical properties and particle size, BC-CO correlations, ship location data and meteorological variables. From February 2012 to September 2013 and March 2014 to February 2015, continuous in-situ measurements of light scattering and absorption coefficients, particle size distribution and concentrations of BC and CO were conducted at Hok Tsui (HT), a coastal background station on the southeast tip of Hong Kong Island (22.22°N, 114.25°E, 60 m above the sea level) with few local anthropogenic activities. Affected by the Asian monsoon, this region is dominated by continental outflow in winter and by marine inflow from the South China Sea in summer, which is an ideal station for identifying the transport characteristics of aerosol and their effects on optical properties from different anthropogenic emission sources. 7-day backward Lagrangian particle dispersion modeling was performed for source identification. Three types of cases dominantly influenced by the PRD regional emission, long-range transport and marine exhaust were compared and discussed in detail.

ACMEV-SP2 (Single Particle Soot Photometer)

DOE Data Explorer

Sedlacek, Arthur

2015-06-01

The SP2 provides information on the amounts of rBC (refractory black carbon) and of other, non-refractory substances associated with individual rBC containing particles by simultaneously measuring the scattering and incandescence signals of such particles that are directed through the cavity of a 1064 nm Nd:YAG laser. (refractory Black Carbon) rBC mixing ratio (ng/Kg) and number size distribution time series collected during the DOE-ARM sponsored ACME-V field campaign held from June 1 to September 15, 2015 rBC mixing ratio is reported at STP conditions Time resolution: 10 sec Uncertainty: ~ 30% SP2 Unit: 25 Location: Deadhorse, AK Location: N 70-degree 11' 41'' - W 148-degress. 27' 55'' SP2_dateTime: UTC rBC concentration is in units of ng/Kg - dry air. Mass Equivalent Diameters [MED] used for size distribution (SP2_min; SP2_geo; and SP2_max) are in units of micrometers dN/dlogDp counts for a given size bin (SP2_geo) listed as 'SP2_cnts_0 - SP2_cnts_199' and are in units of #/cc. Column naming convention: 'SP2_cnts_X' are the number of particles in bin number _X. , where _X is the row number within the 'SP2_geo' size bin column that contains the mass equivalent diameter (e.g., SP2_cnts_0 = 0.01 microns; SP2_cnts_10 = 0.060 microns, etc.). The dN/dlogDp data is time-resolved where a given row is associated with the timestamp for that row. Note that the rBC column length is one field shorter than the SP2_datetime column. Last time field is not relevant to the rBC time series (see comment below on length of SP2_datetime column) Lengths for SP2_max; SP2_min; SP2_geo are one field longer then the number of SP2_cnts_XX columns . This is to provide bounds for image plots (if desired). Length for SP2_datetime is one field longer than that length of the SP2_cnts_XX columns This is to provide bounds for image plots (if desired) SP2 Calibration: Fullerene soot with corrrection applied for particle density as a function of particle size. No correction for OC content in Fullerene (recent study on SP2 sensitivity to differing black carbon types reports that non-refractory material content for fullerene soot is about 20%).

The number and distribution of AMPA receptor channels containing fast kinetic GluA3 and GluA4 subunits at auditory nerve synapses depend on the target cells.

PubMed

Rubio, María E; Matsui, Ko; Fukazawa, Yugo; Kamasawa, Naomi; Harada, Harumi; Itakura, Makoto; Molnár, Elek; Abe, Manabu; Sakimura, Kenji; Shigemoto, Ryuichi

2017-11-01

The neurotransmitter receptor subtype, number, density, and distribution relative to the location of transmitter release sites are key determinants of signal transmission. AMPA-type ionotropic glutamate receptors (AMPARs) containing GluA3 and GluA4 subunits are prominently expressed in subsets of neurons capable of firing action potentials at high frequencies, such as auditory relay neurons. The auditory nerve (AN) forms glutamatergic synapses on two types of relay neurons, bushy cells (BCs) and fusiform cells (FCs) of the cochlear nucleus. AN-BC and AN-FC synapses have distinct kinetics; thus, we investigated whether the number, density, and localization of GluA3 and GluA4 subunits in these synapses are differentially organized using quantitative freeze-fracture replica immunogold labeling. We identify a positive correlation between the number of AMPARs and the size of AN-BC and AN-FC synapses. Both types of AN synapses have similar numbers of AMPARs; however, the AN-BC have a higher density of AMPARs than AN-FC synapses, because the AN-BC synapses are smaller. A higher number and density of GluA3 subunits are observed at AN-BC synapses, whereas a higher number and density of GluA4 subunits are observed at AN-FC synapses. The intrasynaptic distribution of immunogold labeling revealed that AMPAR subunits, particularly GluA3, are concentrated at the center of the AN-BC synapses. The central distribution of AMPARs is absent in GluA3-knockout mice, and gold particles are evenly distributed along the postsynaptic density. GluA4 gold labeling was homogenously distributed along both synapse types. Thus, GluA3 and GluA4 subunits are distributed at AN synapses in a target-cell-dependent manner.

The colors of biomass burning aerosols in the atmosphere.

PubMed

Liu, Chao; Chung, Chul Eddy; Zhang, Feng; Yin, Yan

2016-06-16

Biomass burning aerosols mainly consist of black carbon (BC) and organic aerosols (OAs), and some of OAs are brown carbon (BrC). This study simulates the colors of BrC, BC and their mixture with scattering OAs in the ambient atmosphere by using a combination of light scattering simulations, a two-stream radiative transfer model and a RGB (Red, Green, Blue) color model. We find that both BCs and tar balls (a class of BrC) appear brownish at small particle sizes and blackish at large sizes. This is because the aerosol absorption Ångström exponent (AAE) largely controls the color and larger particles give smaller AAE values. At realistic size distributions, BCs look more blackish than tar balls, but still exhibit some brown color. However, when the absorptance of aerosol layer at green wavelength becomes larger than approximately 0.8, all biomass burning aerosols look blackish. The colors for mixture of purely scattering and absorptive carbonaceous aerosol layers in the atmosphere are also investigated. We suggest that the brownishness of biomass burning aerosols indicates the amount of BC/BrC as well as the ratio of BC to BrC.

Light-Absorbing Aerosol during NASA GRIP: Overview of Observations in the Free Troposphere and Associated with Tropical Storm Systems

NASA Astrophysics Data System (ADS)

Ziemba, L. D.; Beyersdorf, A. J.; Chen, G.; Corr, C. A.; Craig, L.; Dhaniyala, S.; Dibb, J. E.; Hudgins, C. H.; Ismail, S.; Latham, T.; Nenes, A.; Thornhill, K. L.; Winstead, E.; Anderson, B. E.

2010-12-01

Aerosols play a significant role in regulating Earth’s climate. Absorbing aerosols typically constitute a small fraction of ambient particle mass but can contribute significantly to direct and indirect climate forcing depending on size, mixing state, concentration, chemical composition, and vertical and spatial distribution. Aerosols may also significantly affect tropical storm/hurricane dynamics through direct light absorption and activation as cloud nuclei. An extensive suite of instrumentation measuring aerosol chemical, physical, and optical properties was deployed aboard the NASA DC-8 to characterize aerosol during the NASA GRIP (Genesis and Rapid Intensification Processes; August-September 2010) mission. The majority of flight time was spent at high altitude (greater than 9 km) and thus much of the sampling was done in the free troposphere, including extensive sampling in the vicinity of tropical storm systems and more diffuse cirrus clouds. With operations based in Fort Lauderdale, FL and St. Croix, U.S. Virgin Islands, a large geographic region was sampled including much of the Gulf of Mexico and tropical Atlantic Ocean. Observations are reported for light-absorbing carbon aerosol (mainly black carbon, BC) primarily using a single particle soot photometer (SP2). The SP2 employs single-particle laser-induced incandescence to provide a mass-specific measurement not subject to scattering interference that is optimal for the low concentration environments like those encountered during GRIP. BC mass concentrations, 100-500 nm size distributions, and mixing state (i.e. coating thickness of scattering material) are presented. Total and sub-micron aerosol absorption coefficients (principally from BC and dust aerosol) are reported using a particle soot absorption photometer (PSAP) along with comparisons with calculated absorption coefficients derived from SP2 observations in various conditions. In addition, dust aerosol is specifically identified using optical and aerodynamic size distributions obtained from an optical particle counter (OPC) and aerodynamic particle sizer (APS), respectively, as well as by filter-based analyses of chemical composition. BC and dust concentrations, size distribution, and optical properties are reported for clear-sky conditions and in the regions surrounding tropical storms to better understand the radial and vertical distribution of light-absorbing aerosol associated with hurricanes. Observations during GRIP are compared to an extensive characterization of the Saharan Air Layer (SAL) made during the 2006 NAMMA (NASA African Monsoon Multidisciplinary Analyses) mission to assess changes in concentration and aerosol size distribution during transport and cloud interaction.

Black carbon aerosol properties measured by a single particle soot photometer in emissions from biomass burning in the laboratory and field

Treesearch

G. R. McMeeking; J. W. Taylor; A. P. Sullivan; M. J. Flynn; S. K. Akagi; C. M. Carrico; J. L. Collett; E. Fortner; T. B. Onasch; S. M. Kreidenweis; R. J. Yokelson; C. Hennigan; A. L. Robinson; H. Coe

2010-01-01

We present SP2 observations of BC mass, size distributions and mixing state in emissions from laboratory and field biomass fires in California, USA. Biomass burning is the primary global black carbon (BC) source, but understanding of the amount emitted and its physical properties at and following emission are limited. The single particle soot photometer (SP2) uses a...

Characterizing the vertical presence of atmospheric black carbon in the in the high Arctic region from airborne measurements

NASA Astrophysics Data System (ADS)

Schulz, H.; Zanatta, M.; Stefanie, W.; Herber, A. B.

2016-12-01

Black carbon (BC) is an important contributor to climate change in the Arctic region. Due to its light absorption behavior, BC leads to a direct warming of the corresponding aerosol layer. Nevertheless, the net Arctic warming induced by BC strongly depends on its vertical distribution. At present, the low level of knowledge in BC vertical variability in the Arctic region may introduce a strong source of uncertainty in radiative forcing estimations. Vertical distribution of refractory black carbon (rBC) was investigated in spring 2015 during an aircraft campaign, as part of the NETCARE (Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments) project. A single particle soot photometer was deployed on the research aircraft POLAR-6 during nine flights over the European and Canadian high Arctic. In the European Arctic, a decreasing vertical trend of rBC mass concentration was observed, with an average of 40 ng m-3 below 1000 m asl, and less than 10 ng m-3 above 3000 m asl. Combining potential temperature trends and number fraction of rBC particles, plume events were isolated from background conditions. At the Canadian site of Alert, low and high altitude background conditions were characterized by an average rBC number fraction below 10%, while higher values (17%) were observed during plume events. rBC mass concentration was found to decrease by a factor of five from low altitude background (27 ng m-3) to high altitude background (5.4 ng m-3). The plume event, located between 2500 and 3000 m asl, represented a discontinuity point in the decreasing vertical trend showing a rBC concentration of 25 ng m-3. Moreover, background conditions were characterized by a rBC mass mean diameter of 230 nm, while during plume events the observed mean size distribution was peaking at 180 nm only. Our work provides new insights on vertical variability of rBC properties and plume outbreaks in the high Arctic. This information is of actual interest for decreasing the high uncertainty of radiative forcing and atmospheric warming estimations in the Arctic region.

Black carbon aerosol size in snow.

PubMed

Schwarz, J P; Gao, R S; Perring, A E; Spackman, J R; Fahey, D W

2013-01-01

The effect of anthropogenic black carbon (BC) aerosol on snow is of enduring interest due to its consequences for climate forcing. Until now, too little attention has been focused on BC's size in snow, an important parameter affecting BC light absorption in snow. Here we present first observations of this parameter, revealing that BC can be shifted to larger sizes in snow than are typically seen in the atmosphere, in part due to the processes associated with BC removal from the atmosphere. Mie theory analysis indicates a corresponding reduction in BC absorption in snow of 40%, making BC size in snow the dominant source of uncertainty in BC's absorption properties for calculations of BC's snow albedo climate forcing. The shift reduces estimated BC global mean snow forcing by 30%, and has scientific implications for our understanding of snow albedo and the processing of atmospheric BC aerosol in snowfall.

Impact of Combustion Efficiency of Open Biomass Burning on the Mixing State of Black Carbon Containing Particles

NASA Astrophysics Data System (ADS)

PAN, X.; Kanaya, Y.; Taketani, F.; Miyakawa, T.; Inomata, S.; Komazaki, Y.; Tanimoto, H.; Uno, I.; Wang, Z.

2014-12-01

Open biomass burning (OBB) experiments were performed in the laboratory environment to investigate the mixing state of refractory black carbon (rBC) in fresh smoke and its dependence on combustion state. A Single-Particle Soot Photometer (SP2) was adopted to measure variation of number size distribution of rBC-containing particles in high temporal resolution. General combustion state of each OBB case was indicated by modified combustion efficiency (MCE) using accumulated enhancement of mixing ratios of carbon dioxide and carbon monoxide during the experiments. We found that mass equivalent diameter (MED) of rBC increased apparently with increase of MCE values, indicating the flaming-dominant combustion tend to produce the rBC particles with relative larger size, probably because of coagulation processes in high concentration condition. Coating thickness of rBC-containing particle was calculated by leading edge only fitting (LEO-fitting) method. In the present study we defined the rBC-containing particles with shell/core (S/C) ratio larger than 2 as "thickly coated" and that less then 1.5 as "thinly coated". As a result, thickly coated rBC particles normally had a relatively small core (MED of rBC less than 150 nm) and its number fraction showed an evident decrease as a function of MCE value, whereas, larger rBC particles (MED larger than 150 nm) were normally thinly coated. Number fraction of both thinly coated and uncoated rBC particles had an positive correlation with MCE value. Substantial amount of light scattering particles (LSP) observed in the smoldering-dominant OBB plumes could partially explain the increase of number fraction of coated rBC particles. ΔrBC/ΔCO ratio showed a good positive correlation with MCE with an average value of 16.8 (1.2 - 51.6) ng/m3/ppbv, and ΔrBC/ΔCO2 ratio was found 628.7 ng/m3/ppmv, generally consistent with previous studies.

Emission characteristics of refractory black carbon aerosols from fresh biomass burning: a perspective from laboratory experiments

NASA Astrophysics Data System (ADS)

Pan, Xiaole; Kanaya, Yugo; Taketani, Fumikazu; Miyakawa, Takuma; Inomata, Satoshi; Komazaki, Yuichi; Tanimoto, Hiroshi; Wang, Zhe; Uno, Itsushi; Wang, Zifa

2017-11-01

The emission characteristics of refractory black carbon (rBC) from biomass burning are essential information for numerical simulations of regional pollution and climate effects. We conducted combustion experiments in the laboratory to investigate the emission ratio and mixing state of rBC from the burning of wheat straw and rapeseed plants, which are the main crops cultivated in the Yangtze River Delta region of China. A single particle soot photometer (SP2) was used to measure rBC-containing particles at high temporal resolution and with high accuracy. The combustion state of each burning case was indicated by the modified combustion efficiency (MCE), which is calculated using the integrated enhancement of carbon dioxide and carbon monoxide concentrations relative to their background values. The mass size distribution of the rBC particles showed a lognormal shape with a mode mass equivalent diameter (MED) of 189 nm (ranging from 152 to 215 nm), assuming an rBC density of 1.8 g cm-3. rBC particles less than 80 nm in size (the lower detection limit of the SP2) accounted for ˜ 5 % of the total rBC mass, on average. The emission ratios, which are expressed as ΔrBC / ΔCO (Δ indicates the difference between the observed and background values), displayed a significant positive correlation with the MCE values and varied between 1.8 and 34 ng m-3 ppbv-1. Multi-peak fitting analysis of the delay time (Δt, or the time of occurrence of the scattering peak minus that of the incandescence peak) distribution showed that rBC-containing particles with rBC MED = 200 ± 10 nm displayed two peaks at Δt = 1.7 µs and Δt = 3.2 µs, which could be attributed to the contributions from both flaming and smoldering combustion in each burning case. Both the Δt values and the shell / core ratios of the rBC-containing particles clearly increased as the MCE decreased from 0.98 (smoldering-dominant combustion) to 0.86 (flaming-dominant combustion), implying the great importance of the rapid condensation of semi-volatile organics. This laboratory study found that the mixing state of rBC particles from biomass burning strongly depends on its combustion processes, and overall MCE should be taken carefully into consideration while the climate effect of rBC particles from open biomass burning is simulated.

Development of the Small Package Single Particle Soot Photometer with extended range (SP2-XR) and black carbon detection efficiency compared to its predecessor, the SP2

NASA Astrophysics Data System (ADS)

Schulz, H.; Kok, G. L.; Zanatta, M.; Schwarz, J. P.; Herber, A. B.

2016-12-01

Black carbon (BC) aerosol is an important contributor to climate change due to its ability to very efficiently absorb solar radiation. The Single Particle Soot Photometer (SP2) is an instrument that quantifies the refractory mass of individual BC-containing particles with a laser-induced incandescence method. The SP2 has been deployed on ships, at ground based sites, and on research aircraft to quantify BC's mass loadings and microphysical properties. However, the SP2's particle detection range is generally limited to 70-700 nm volume-equivalent diameter for ambient BC. Ambient air typically contains substantial number concentrations below and mass concentrations above the limits of this range. To account for the unquantified particles, it is common to fit a log-normal distribution to the measured size distributions — an approach that leaves the BC community with uncertain results, and a need to learn about the occurrence of very small particles or very large BC aggregates. The SP2 is also large and heavy enough to limit its usability for aircraft and unmanned or towed airborne vehicles. We have developed a miniaturized SP2 to dramatically extend the range of applications for which the SP2 technique can be used. This new instrument, with the additional target of an extended measurement range, has been named the SP2-XR, and incorporates a newly designed optical block with updated electronics for signal recording and on-the-fly processing (gain stitching and peak analysis). The optical block improves the light-collection of both scattered and incandescent light from sampled particles. The target measurement range is 40-1000 nm. At the same time, the SP2-XR weighs less than half of an SP2 (15 kg for the complete system), and about 1/4 the volume ( 20 cm x 20 cm x 40 cm). The instrument software is designed to produce ready to use particle mass and binned size distributions or full particle trace records, according to different scientific needs. Thus, an SP2-XR may produce a much slimmer data set while deployed in the field, compared to the SP2. We have compared the size-resolved detection efficiency and performance of the SP2-XR to two classic SP2 system using a DMA/CPC system. Measurements covered different BC standards (Aquadag and Fullerene Soot), PSL particles, and ambient aerosol. Test results will be presented.

Size-resolved chemical composition, effective density, and optical properties of biomass burning particles

NASA Astrophysics Data System (ADS)

Zhai, Jinghao; Lu, Xiaohui; Li, Ling; Zhang, Qi; Zhang, Ci; Chen, Hong; Yang, Xin; Chen, Jianmin

2017-06-01

Biomass burning aerosol has an important impact on the global radiative budget. A better understanding of the correlations between the mixing states of biomass burning particles and their optical properties is the goal of a number of current studies. In this work, the effective density, chemical composition, and optical properties of rice straw burning particles in the size range of 50-400 nm were measured using a suite of online methods. We found that the major components of particles produced by burning rice straw included black carbon (BC), organic carbon (OC), and potassium salts, but the mixing states of particles were strongly size dependent. Particles of 50 nm had the smallest effective density (1.16 g cm-3) due to a relatively large proportion of aggregate BC. The average effective densities of 100-400 nm particles ranged from 1.35 to 1.51 g cm-3 with OC and inorganic salts as dominant components. Both density distribution and single-particle mass spectrometry showed more complex mixing states in larger particles. Upon heating, the separation of the effective density distribution modes confirmed the external mixing state of less-volatile BC or soot and potassium salts. The size-resolved optical properties of biomass burning particles were investigated at two wavelengths (λ = 450 and 530 nm). The single-scattering albedo (SSA) showed the lowest value for 50 nm particles (0.741 ± 0.007 and 0.889 ± 0.006) because of the larger proportion of BC content. Brown carbon played an important role for the SSA of 100-400 nm particles. The Ångström absorption exponent (AAE) values for all particles were above 1.6, indicating the significant presence of brown carbon in all sizes. Concurrent measurements in our work provide a basis for discussing the physicochemical properties of biomass burning aerosol and its effects on the global climate and atmospheric environment.

AERONET derived (BC) aerosol absorption

NASA Astrophysics Data System (ADS)

Kinne, S.

2015-12-01

AERONET is a ground-based sun-/sky-photometer network with good annual statistics at more than 400 sites worldwide. Inversion methods applied to these data define all relevant column aerosol optical properties and reveal even microphysical detail. The extracted data include estimates for aerosol size-distributions and for aerosol refractive indices at four different solar wavelengths. Hereby, the imaginary parts of the refractive indices define the aerosol column absorption. For regional and global averages and radiative impact assessment with off-line radiative transfer, these local data have been extended with distribution patterns offered by AeroCom modeling experiments. Annual and seasonal absorption distributions for total aerosol and estimates for component contributions (such as BC) are presented and associated direct forcing impacts are quantified.

Development of an aerosol microphysical module: Aerosol Two-dimensional bin module for foRmation and Aging Simulation (ATRAS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsui, H.; Koike, Makoto; Kondo, Yutaka

2014-09-30

Number concentrations, size distributions, and mixing states of aerosols are essential parameters for accurate estimation of aerosol direct and indirect effects. In this study, we developed an aerosol module, designated Aerosol Two-dimensional bin module for foRmation and Aging Simulation (ATRAS), that can represent these parameters explicitly by considering new particle formation (NPF), black carbon (BC) aging, and secondary organic aerosol (SOA) processes. A two-dimensional bin representation is used for particles with dry diameters from 40 nm to 10 µm to resolve both aerosol size (12 bins) and BC mixing state (10 bins) for a total of 120 bins. The particlesmore » with diameters from 1 to 40 nm are resolved using an additional 8 size bins to calculate NPF. The ATRAS module was implemented in the WRF-chem model and applied to examine the sensitivity of simulated mass, number, size distributions, and optical and radiative parameters of aerosols to NPF, BC aging and SOA processes over East Asia during the spring of 2009. BC absorption enhancement by coating materials was about 50% over East Asia during the spring, and the contribution of SOA processes to the absorption enhancement was estimated to be 10 – 20% over northern East Asia and 20 – 35% over southern East Asia. A clear north-south contrast was also found between the impacts of NPF and SOA processes on cloud condensation nuclei (CCN) concentrations: NPF increased CCN concentrations at higher supersaturations (smaller particles) over northern East Asia, whereas SOA increased CCN concentrations at lower supersaturations (larger particles) over southern East Asia. Application of ATRAS to East Asia also showed that the impact of each process on each optical and radiative parameter depended strongly on the process and the parameter in question. The module can be used in the future as a benchmark model to evaluate the accuracy of simpler aerosol models and examine interactions between NPF, BC aging, and SOA processes under different meteorological conditions and emissions.« less

Sub-micron particle number size distribution characteristics at two urban locations in Leicester

NASA Astrophysics Data System (ADS)

Hama, Sarkawt M. L.; Cordell, Rebecca L.; Kos, Gerard P. A.; Weijers, E. P.; Monks, Paul S.

2017-09-01

The particle number size distribution (PNSD) of atmospheric particles not only provides information about sources and atmospheric processing of particles, but also plays an important role in determining regional lung dose. Owing to the importance of PNSD in understanding particulate pollution two short-term campaigns (March-June 2014) measurements of sub-micron PNSD were conducted at two urban background locations in Leicester, UK. At the first site, Leicester Automatic Urban Rural Network (AURN), the mean number concentrations of nucleation, Aitken, accumulation modes, the total particles, equivalent black carbon (eBC) mass concentrations were 2002, 3258, 1576, 6837 # cm-3, 1.7 μg m-3, respectively, and at the second site, Brookfield (BF), were 1455, 2407, 874, 4737 # cm-3, 0.77 μg m-3, respectively. The total particle number was dominated by the nucleation and Aitken modes, with both consisting of 77%, and 81% of total number concentrations at AURN and BF sites, respectively. This behaviour could be attributed to primary emissions (traffic) of ultrafine particles and the temporal evolution of mixing layer. The size distribution at the AURN site shows bimodal distribution at 22 nm with a minor peak at 70 nm. The size distribution at BF site, however, exhibits unimodal distribution at 35 nm. This study has for the first time investigated the effect of Easter holiday on PNSD in UK. The temporal variation of PNSD demonstrated a good degree of correlation with traffic-related pollutants (NOX, and eBC at both sites). The meteorological conditions, also had an impact on the PNSD and eBC at both sites. During the measurement period, the frequency of NPF events was calculated to be 13.3%, and 22.2% at AURN and BF sites, respectively. The average value of formation and growth rates of nucleation mode particles were 1.3, and 1.17 cm-3 s-1 and 7.42, and 5.3 nm h-1 at AURN, and BF sites, respectively. It can suggested that aerosol particles in Leicester originate mainly from traffic and domestic heating emissions.

Aerosol Size, CCN, and Black Carbon Properties at a Coastal Site in the Eastern U.S.

NASA Astrophysics Data System (ADS)

Royalty, T. M.; Petters, M. D.; Grieshop, A. P.; Meskhidze, N.; Reed, R. E.; Phillips, B.; Dawson, K. W.

2015-12-01

Atmospheric aerosols play an important role in regulating the global radiative budget through direct and indirect effects. To date, the role of sea spray aerosols in modulating climate remains poorly understood. Here we present results from measurements performed at the United States Army Corps of Engineers' Field Research Facility in Duck, North Carolina, USA. Aerosol mobility size distributions (10-600 nm), refractory black carbon (rBC) and scattering particle size distributions (200-620 nm), and size resolved cloud condensation nuclei distributions (.07% - .6% supersaturation) were collected at the end of a 560m pier. Aerosol characteristics associated with northerly, high wind speed (15+ m s-1) flow originating from an oceanic trajectory are contrasted with aerosol properties observed during a weak to moderate westerly flow originating from a continental trajectory. Both marine and continental air masses had aerosol with bi-modal number size distributions with modes centered at 30nm and 140nm. In the marine air-mass, the CCN concentration at supersaturation of 0.4%, total aerosol number, surface, and volume concentration were low. rBC number concentration (D > 200 nm) associated with the marine air-mass was an order of magnitude less than continental number concentration and indicative of relatively unpolluted air. These measurements are consistent with measurements from other coastal sites under marine influence. The relative proportion of Aitken mode size particles increased from 1:2 to 2:1 while aerosol surface area was < 25 μm2 cm-3, suggesting that conditions upwind were potentially conducive to new particle formation. Overall, these results will contribute a better understanding to composition and size variation of marine aerosols.

Parametric uncertainties in global model simulations of black carbon column mass concentration

NASA Astrophysics Data System (ADS)

Pearce, Hana; Lee, Lindsay; Reddington, Carly; Carslaw, Ken; Mann, Graham

2016-04-01

Previous studies have deduced that the annual mean direct radiative forcing from black carbon (BC) aerosol may regionally be up to 5 W m-2 larger than expected due to underestimation of global atmospheric BC absorption in models. We have identified the magnitude and important sources of parametric uncertainty in simulations of BC column mass concentration from a global aerosol microphysics model (GLOMAP-Mode). A variance-based uncertainty analysis of 28 parameters has been performed, based on statistical emulators trained on model output from GLOMAP-Mode. This is the largest number of uncertain model parameters to be considered in a BC uncertainty analysis to date and covers primary aerosol emissions, microphysical processes and structural parameters related to the aerosol size distribution. We will present several recommendations for further research to improve the fidelity of simulated BC. In brief, we find that the standard deviation around the simulated mean annual BC column mass concentration varies globally between 2.5 x 10-9 g cm-2 in remote marine regions and 1.25 x 10-6 g cm-2 near emission sources due to parameter uncertainty Between 60 and 90% of the variance over source regions is due to uncertainty associated with primary BC emission fluxes, including biomass burning, fossil fuel and biofuel emissions. While the contributions to BC column uncertainty from microphysical processes, for example those related to dry and wet deposition, are increased over remote regions, we find that emissions still make an important contribution in these areas. It is likely, however, that the importance of structural model error, i.e. differences between models, is greater than parametric uncertainty. We have extended our analysis to emulate vertical BC profiles at several locations in the mid-Pacific Ocean and identify the parameters contributing to uncertainty in the vertical distribution of black carbon at these locations. We will present preliminary comparisons of emulated BC vertical profiles from the AeroCom multi-model ensemble and Hiaper Pole-to-Pole (HIPPO) observations.

Toward a mechanistic understanding of the effect of biochar addition on soil water retention

NASA Astrophysics Data System (ADS)

Yi, S.; Chang, N.; Guo, M.; Imhoff, P. T.

2014-12-01

Biochar (BC) is a carbon-rich product produced by thermal degradation of biomass in an oxygen-free environment, whose application to sediment is said to improve water retention. However, BC produced from different feedstocks and pyrolyzed at different temperatures have distinct properties, which may alter water retention in ways difficult to predict a priori. Our goal is to develop a mechanistic understanding of BC addition on water retention by examining the impact of BC from two feedstocks, poultry litter (PL) and hardwood (HW), on the soil-water retention curves (SWRC) of a uniform sand and a sandy loam (SL). For experiments with sand, BC and sand were sieved to the same particle size (~ 0.547 mm) to minimize effects of BC addition on particle size distribution. Experiments with SL contained the same sieved BC. PL and HW bicohars were added at 2 and 7% (w/w), and water retention was measured from 0 to -4.38 × 106 cm-H2O. Both BCs increased porosities for sand and SL, up to 39 and 13% for sand and SL, respectively, with 7% HW BC addition. The primary cause for these increases was the internal porosity of BC particles. While the matric potential for air-entry was unchanged with BC addition, BC amendment increased water retention for sand and SL in the capillary region (0 to -15,000 cm-H2O) by an average of 26 and 33 % for 7% PL and HW BC in sand, respectively, but only 7 and 14 % for 7% PL and HW BC in SL. The most dramatic influence of BC amendment on water retention occurred in the adsorption region (< -15,000 cm-H2O), where water retention increased by a factor of 11 and 22 for 7% PL and HW BC in sand, respectively, but by 140 and 190 % for 7% PL and HW BC in SL, respectively. The impact of BC on water retention in these sediments is explained primarily by the additional surface area and internal porosity of PL and HW BC particles. van Genuchten (VG) models were fitted to the water retention data. For SL where the impact of BC addition on water retention was less significant, a unimodal model fit water retention data well for unamended and BC-amended media: the addition of BC did not create a new class of small pores that could not be described with a unimodal VG model. While a unimodal model fitted the sand data well, a bimodal model was required for all BC-amended sand. The influence of BC type, mass fraction and sediment on water retention models will be discussed.

Characterization of Ambient Black Carbon Aerosols

NASA Astrophysics Data System (ADS)

Zhang, R.; Levy, M. E.; Zheng, J.; Molina, L. T.

2013-12-01

Because of the strong absorption over a broad range of the electromagnetic spectra, black carbon (BC) is a key short-lived climate forcer, which contributes significantly to climate change by direct radiative forcing and is the second most important component causing global warming after carbon dioxide. The impact of BC on the radiative forcing of the Earth-Atmosphere system is highly dependent of the particle properties. In this presentation, emphasis will be placed on characterizing BC containing aerosols in at the California-Mexico border to obtain a greater understanding of the atmospheric aging and properties of ambient BC aerosols. A comprehensive set of directly measured aerosol properties, including the particle size distribution, effective density, hygroscopicity, volatility, and several optical properties, will be discussed to quantify the mixing state and composition of ambient particles. In Tijuana, Mexico, submicron aerosols are strongly influenced by vehicle emissions; subsequently, the BC concentration in Tijuana is considerably higher than most US cities with an average BC concentration of 2.71 × 2.65 g cm-3. BC accounts for 24.75 % × 9.44 of the total submicron concentration on average, but periodically accounts for over 50%. This high concentration of BC strongly influences many observed aerosol properties such as single scattering albedo, hygroscopicity, effective density, and volatility.

Vertical profiles of aerosol and black carbon in the Arctic: a seasonal phenomenology along 2 years (2011-2012) of field campaigns

NASA Astrophysics Data System (ADS)

Ferrero, Luca; Cappelletti, David; Busetto, Maurizio; Mazzola, Mauro; Lupi, Angelo; Lanconelli, Christian; Becagli, Silvia; Traversi, Rita; Caiazzo, Laura; Giardi, Fabio; Moroni, Beatrice; Crocchianti, Stefano; Fierz, Martin; Močnik, Griša; Sangiorgi, Giorgia; Perrone, Maria G.; Maturilli, Marion; Vitale, Vito; Udisti, Roberto; Bolzacchini, Ezio

2016-10-01

We present results from a systematic study of vertical profiles of aerosol number size distribution and black carbon (BC) concentrations conducted in the Arctic, over Ny-Ålesund (Svalbard). The campaign lasted 2 years (2011-2012) and resulted in 200 vertical profiles measured by means of a tethered balloon (up to 1200 m a.g.l.) during the spring and summer seasons. In addition, chemical analysis of filter samples, aerosol size distribution and a full set of meteorological parameters were determined at ground. The collected experimental data allowed a classification of the vertical profiles into different typologies, which allowed us to describe the seasonal phenomenology of vertical aerosol properties in the Arctic. During spring, four main types of profiles were found and their behavior was related to the main aerosol and atmospheric dynamics occurring at the measuring site. Background conditions generated homogenous profiles. Transport events caused an increase of aerosol concentration with altitude. High Arctic haze pollution trapped below thermal inversions promoted a decrease of aerosol concentration with altitude. Finally, ground-based plumes of locally formed secondary aerosol determined profiles with decreasing aerosol concentration located at different altitude as a function of size. During the summer season, the impact from shipping caused aerosol and BC pollution plumes to be constrained close to the ground, indicating that increasing shipping emissions in the Arctic could bring anthropogenic aerosol and BC in the Arctic summer, affecting the climate.

Properties of refractory BC containing particles during the ACRIDICON-CHUVA aircraft campaign in the Amazon basin

NASA Astrophysics Data System (ADS)

Holanda, Bruna; Pöhlker, Mira; Klimach, Thomas; Saturno, Jorge; Ditas, Florian; Ditas, Jeannine; Ma, Nan; Zhang, Yuxuan; Cheng, Yafang; Wendisch, Manfred; Machado, Luiz; Barbosa, Henrique; Pöhlker, Christopher; Artaxo, Paulo; Pöschl, Ulrich; Andreae, Meinrat

2017-04-01

Black carbon (BC) particles are emitted directly into the atmosphere by processes of incomplete combustion and therefore can be used as a tracer of atmospheric pollution. BC is considered one of the drivers of global warming due to its efficient absorption of solar and infra-red radiation (Bond et al., 2013). Depending on abundance and size, aerosols can also modify the characteristics of clouds and enhance or suppress precipitation (Pöschl et al., 2010). The BC particles can gain surface coatings by condensation of low and semi-volatile compounds, coagulation, and cloud processing. The inclusion of a non-absorbing coating influences the way that BC particles act as cloud nuclei and may increase their absorption through the lensing effect (Fuller et al., 1999). These aging processes change significantly the optical, chemical and physical properties of the particles, as well as their atmospheric lifetime, making BC a source of large uncertainties in current atmospheric models. Taking into account the complex dynamics of BC particles in the atmosphere, we are analyzing data from the ACRIDICON-CHUVA aircraft campaign, which took place in the Amazon basin, Brazil, during the dry season of 2014 (Wendisch et al., 2016). A detailed characterization of BC particles was done using the Single Particle Soot Photometer (SP2) instrument, which directly measures the mass of individual refractory BC particles (rBC). Additionally, the SP2 provides information about the size distribution of rBC cores and their associated coatings. These properties were measured covering a wide geographic area with different pollution conditions and at several levels of the atmosphere at high time resolution. The rBC concentrations change significantly with altitude and with the source of pollution, being a few nanograms per cubic meter for altitudes higher that 5 km. In the surroundings of Manaus city, the mean BC concentration was 0.7 μg/m3, with core sizes peaking at 180 nm. The highest BC mass values were observed over fresh biomass burning plumes (6 μg/m3) with smaller core sizes ( 150 nm). Moreover, in a specific flight (AC19) we identified an extended layer of pollution at 4 km altitude. Backward trajectories calculated using FLEXPART suggest that this pollution layer originated in Africa and has aged few days during its travel over the Atlantic. Similarities in the properties of rBC particles within the pollution and boundary layers suggest that the long range transport of pollution from Africa can be an important source of BC to the Amazonian atmosphere. Here we present first results from our analyses that characterize the various pollution aerosols and their properties in the Amazon basin. References Bond, T.C. et al., 2013. Bounding the role of black carbon in the climate system: A scientific assessment. Journal of Geophysical Research: Atmospheres, 118(11), pp.5380-5552. Fuller, K. A. et al., 1999. Effects of mixing on extinction by carbonaceous particles. Journal of Geophysical Research: Atmospheres, 104(D13), 15941-15954. Pöschl, U. et al., 2010. Rainforest aerosols as biogenic nuclei of clouds and precipitation in the Amazon. Science 329, 1513. Wendisch, M. et al., 2016. The ACRIDICON-CHUVA campaign: Studying tropical deep convective clouds and precipitation over Amazonia using the new German research aircraft HALO. Bull. Amer. Meteor. Soc.

Diurnal cycling of urban aerosols under different weather regimes

NASA Astrophysics Data System (ADS)

Gregorič, Asta; Drinovec, Luka; Močnik, Griša; Remškar, Maja; Vaupotič, Janja; Stanič, Samo

2016-04-01

A one month measurement campaign was performed in summer 2014 in Ljubljana, the capital of Slovenia (population 280,000), aiming to study temporal and spatial distribution of urban aerosols and the mixing state of primary and secondary aerosols. Two background locations were chosen for this purpose, the first one in the city center (urban background - KIS) and the second one in the suburban background (Brezovica). Simultaneous measurements of black carbon (BC) and particle number size distribution of submicron aerosols (PM1) were conducted at both locations. In the summer season emission from traffic related sources is expected to be the main local contribution to BC concentration. Concentrations of aerosol species and gaseous pollutants within the planetary boundary layer are controlled by the balance between emission sources of primary aerosols and gases, production of secondary aerosols, chemical reactions of precursor gases under solar radiation and the rate of dilution by mixing within the planetary boundary layer (PBL) as well as with tropospheric air. Only local emission sources contribute to BC concentration during the stable PBL with low mixing layer height, whereas during the time of fully mixed PBL, regionally transported BC and other aerosols can contribute to the surface measurements. The study describes the diurnal behaviour of the submicron aerosol at the urban and suburban background location under different weather regimes. Particles in three size modes - nucleation (< 25 nm, NUM), Aitken (25 - 90 nm, AIM) and accumulation mode (90 - 800 nm, ACM), as well as BC mass concentration were evaluated separately for sunny, cloudy and rainy days, taking into account modelled values of PBL height. Higher particle number and black carbon concentrations were observed at the urban background (KIS) than at the suburban background location (Brezovica). Significant diurnal pattern of total particle concentration and black carbon concentration was observed at both locations, with a distinct morning and late afternoon peak. As a consequence of different PBL dynamics and atmospheric processes (photochemical effects, humidity, wind speed and direction), diurnal profile differs for sunny, cloudy and rainy days. Nucleation mode particles were found to be subjected to lower daily variation and only slightly influenced by weather, as opposed to Aitken and accumulation mode particles. The highest correlation between BC and particle number concentration is observed during stable atmospheric conditions in the night and morning hours and is attributed to different particle size modes, depending on the distance to local BC emission sources. In sunny weather conditions, correlation between BC and particle number concentration decreases during the day due to mixing in the atmosphere and formation of secondary aerosols. Black carbon aging and mixing with secondary aerosols was additionally studied on the aerosol samples taken from the morning to the evening of a sunny day using SEM-EDX technique.

Scavenging of black carbon in mixed phase clouds at the high alpine site Jungfraujoch

NASA Astrophysics Data System (ADS)

Cozic, J.; Verheggen, B.; Mertes, S.; Connolly, P.; Bower, K.; Petzold, A.; Baltensperger, U.; Weingartner, E.

2007-04-01

The scavenging of black carbon (BC) in liquid and mixed phase clouds was investigated during intensive experiments in winter 2004, summer 2004 and winter 2005 at the high alpine research station Jungfraujoch (3580 m a.s.l., Switzerland). Aerosol residuals were sampled behind two well characterized inlets; a total inlet which collected cloud particles (droplets and ice particles) as well as interstitial (unactivated) aerosol particles; an interstitial inlet which collected only interstitial aerosol particles. BC concentrations were measured behind each of these inlets along with the submicrometer aerosol number size distribution, from which a volume concentration was derived. These measurements were complemented by in-situ measurements of cloud microphysical parameters. BC was found to be scavenged into the condensed phase to the same extent as the bulk aerosol, which suggests that BC was covered with soluble material through aging processes, rendering it more hygroscopic. The scavenged fraction of BC (FScav,BC), defined as the fraction of BC that is incorporated into cloud droplets and ice crystals, decreases with increasing cloud ice mass fraction (IMF) from FScav,BC=60% in liquid phase clouds to FScav,BC~5-10% in mixed-phase clouds with IMF>0.2. This can be explained by the evaporation of liquid droplets in the presence of ice crystals (Wegener-Bergeron-Findeisen process), releasing BC containing cloud condensation nuclei back into the interstitial phase. In liquid clouds, the scavenged BC fraction is found to decrease with decreasing cloud liquid water content. The scavenged BC fraction is also found to decrease with increasing BC mass concentration since there is an increased competition for the available water vapour.

Scavenging of black carbon in mixed phase clouds at the high alpine site Jungfraujoch

NASA Astrophysics Data System (ADS)

Cozic, J.; Verheggen, B.; Mertes, S.; Connolly, P.; Bower, K.; Petzold, A.; Baltensperger, U.; Weingartner, E.

2006-11-01

The scavenging of black carbon (BC) in liquid and mixed phase clouds was investigated during intensive experiments in winter 2004, summer 2004 and winter 2005 at the high alpine research station Jungfraujoch (3580 m a.s.l., Switzerland). Aerosol residuals were sampled behind two well characterized inlets; a total inlet which collected cloud particles (drops and ice particles) as well as interstitial aerosol particles; an interstitial inlet which collected only interstitial (unactivated) aerosol particles. BC concentrations were measured behind each of these inlets along with the submicrometer aerosol number size distribution, from which a volume concentration was derived. These measurements were complemented by in-situ measurements of cloud microphysical parameters. BC was found to be scavenged into the cloud phase to the same extent as the bulk aerosol, which suggests that BC was covered with soluble material through aging processes, rendering it more hygroscopic. The scavenged fraction of BC (FScav,BC), defined as the fraction of BC that is incorporated into cloud droplets and ice crystals, decreases with increasing cloud ice mass fraction (IMF) from FScav,BC=60% in liquid phase clouds to FScav,BC~10% in mixed-phase clouds with IMF>0.2. This is explained by the evaporation of liquid droplets in the presence of ice crystals (Wegener-Bergeron-Findeisen process), releasing BC containing cloud condensation nuclei back into the interstitial phase. In liquid clouds, the scavenged BC fraction is found to decrease with decreasing cloud liquid water content. The scavenged BC fraction is also found to decrease with increasing BC mass concentration since there is an increased competition for the available water vapour.

Micropore clogging by leachable pyrogenic organic carbon: A new perspective on sorption irreversibility and kinetics of hydrophobic organic contaminants to black carbon.

PubMed

Wang, Bingyu; Zhang, Wei; Li, Hui; Fu, Heyun; Qu, Xiaolei; Zhu, Dongqiang

2017-01-01

Black carbon (BC) plays a crucial role in sequestering hydrophobic organic contaminants in the environment. This study investigated key factors and mechanisms controlling nonideal sorption (e.g., sorption irreversibility and slow kinetics) of model hydrophobic organic contaminants (nitrobenzene, naphthalene, and atrazine) by rice-straw-derived BC. After removing the fraction of leachable pyrogenic organic carbon (LPyOC) (referring to composites of dissoluble non-condensed organic carbon and associated mineral components) with deionized water or 0.5 M NaOH, sorption of these sorbates to BC was enhanced. The sorption enhancement was positively correlated with sorbate molecular size in the order of atrazine > naphthalene > nitrobenzene. The removal of LPyOC also accelerated sorption kinetics and reduced sorption irreversibility. These observations were attributed to increased accessibility of BC micropores initially clogged by the LPyOC. Comparison of BC pore size distributions before and after atrazine sorption further suggested that the sorbate molecules preferred to access the micropores that were more open, and the micropore accessibility was enhanced by the removal of LPyOC. Consistently, the sorption of nitrobenzene and atrazine to template-synthesized mesoporous carbon (CMK3), a model sorbent with homogeneous pore structures, showed decreased kinetics, but increased irreversibility by impregnating sorbent pores with surface-grafted alkylamino groups and by subsequent loading of humic acid. These findings indicated an important and previously unrecognized role of LPyOC (i.e., micropore clogging) in the nonideal sorption of organic contaminants to BC. Copyright © 2016 Elsevier Ltd. All rights reserved.

Distribution, input pathway and mass inventory of black carbon in sediments of the Gulf of Thailand, SE Asia

NASA Astrophysics Data System (ADS)

Hu, Limin; Shi, Xuefa; Bai, Yazhi; Fang, Yin; Chen, Yingjun; Qiao, Shuqing; Liu, Shengfa; Yang, Gang; Kornkanitnan, Narumol; Khokiattiwong, Somkiat

2016-03-01

The coastal margins around Southeast Asia (SE Asia) may serve as an ideal location to study the source-sink process of sedimentary black carbon (BC) because SE Asia has been identified as one of the major BC emission source regions in the world. This study provides an extensive picture of recent regional-scale sedimentary BC sequestration in the Gulf of Thailand (GOT), a tropical marine system in SE Asia. Generally, the sedimentary BC concentrations (0.07-3.99 mg/g) were in the low to moderate ranges of those obtained in other coastal sediments around the world. Regional variability of the BC and its correlation with the sediment grain size and total organic carbon (TOC) content indicated a general hydrodynamic constraint on BC occurrence in the lower Gulf in contrast to the upper Gulf with a more source dependence due to the direct land-based input. BC/TOC% values and the varied BC components (char and soot), as well as their correlations suggested that char was the predominant constituents of sedimentary BC both in the upper and lower Gulf, which could be mainly derived from biomass burning and entered into the nearshore region through direct fluvial transport and surface run-off. The estimated BC burial flux (∼212 μg/cm2/y) and mass inventory (∼200 Gg/y) in the GOT on the hundred-year timescale were of the same order of magnitude compared with other oceanic margins, and thus the tropical shelf sediments from SE Asia could serve as an important sink of land-emitted BC.

Variation of the radiative properties during black carbon aging: theoretical and experimental intercomparison

DOE PAGES

He, C.; Liou, K.-N.; Takano, Y.; ...

2015-10-28

A theoretical black carbon (BC) aging model is developed to account for three typical evolution stages, namely, freshly emitted aggregates, BC coated by soluble material, and BC particles undergoing further hygroscopic growth. The geometric-optics surface-wave (GOS) approach is employed to compute the BC single-scattering properties at each aging stage, which are subsequently compared with laboratory measurements. Theoretical calculations are consistent with measurements in extinction and absorption cross sections for fresh BC aggregates with different BC sizes (i.e., mobility diameters of 155, 245, and 320 nm), with differences of ≤ 25 %. The measured optical cross sections for BC coated bymore » sulfuric acid and for that undergoing further hygroscopic growth are generally captured (differences < 30 %) by theoretical calculations using a concentric core-shell structure, with an overestimate in extinction and absorption of the smallest BC size and an underestimate in scattering of the largest BC size. We find that the absorption and scattering cross sections of fresh BC aggregates vary by 20–40 and 50–65 %, respectively, due to the use of upper (1.95–0.79 i) and lower (1.75–0.63 i) bounds of BC refractive index, while the variations are < 20 % in absorption and < 50 % in scattering in the case of coated BC particles. Sensitivity analyses of the BC morphology show that the optical properties of fresh BC aggregates are more sensitive to fractal dimension than primary spherule size. The absorption and scattering cross sections of coated BC particles vary by more than a factor of 2 due to different coating structures. We find an increase of 20–250 % in absorption and a factor of 3–15 in scattering during aging, significantly depending on coating morphology and aging stages. This study suggests that an accurate estimate of BC radiative effects requires the incorporation of a dynamic BC aging process that accounts for realistic coating structures in climate models.« less

Variation of the radiative properties during black carbon aging: theoretical and experimental intercomparison

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, C.; Liou, K.-N.; Takano, Y.

A theoretical black carbon (BC) aging model is developed to account for three typical evolution stages, namely, freshly emitted aggregates, BC coated by soluble material, and BC particles undergoing further hygroscopic growth. The geometric-optics surface-wave (GOS) approach is employed to compute the BC single-scattering properties at each aging stage, which are subsequently compared with laboratory measurements. Theoretical calculations are consistent with measurements in extinction and absorption cross sections for fresh BC aggregates with different BC sizes (i.e., mobility diameters of 155, 245, and 320 nm), with differences of ≤ 25 %. The measured optical cross sections for BC coated bymore » sulfuric acid and for that undergoing further hygroscopic growth are generally captured (differences < 30 %) by theoretical calculations using a concentric core-shell structure, with an overestimate in extinction and absorption of the smallest BC size and an underestimate in scattering of the largest BC size. We find that the absorption and scattering cross sections of fresh BC aggregates vary by 20–40 and 50–65 %, respectively, due to the use of upper (1.95–0.79 i) and lower (1.75–0.63 i) bounds of BC refractive index, while the variations are < 20 % in absorption and < 50 % in scattering in the case of coated BC particles. Sensitivity analyses of the BC morphology show that the optical properties of fresh BC aggregates are more sensitive to fractal dimension than primary spherule size. The absorption and scattering cross sections of coated BC particles vary by more than a factor of 2 due to different coating structures. We find an increase of 20–250 % in absorption and a factor of 3–15 in scattering during aging, significantly depending on coating morphology and aging stages. This study suggests that an accurate estimate of BC radiative effects requires the incorporation of a dynamic BC aging process that accounts for realistic coating structures in climate models.« less

Diesel vehicle and urban burning contributions to black carbon concentrations and size distributions in Tijuana, Mexico, during the Cal-Mex 2010 campaign

NASA Astrophysics Data System (ADS)

Takahama, S.; Russell, L. M.; Shores, C. A.; Marr, L. C.; Zheng, J.; Levy, M.; Zhang, R.; Castillo, E.; Rodriguez-Ventura, J. G.; Quintana, P. J. E.; Subramanian, R.; Zavala, M.; Molina, L. T.

2014-05-01

Black carbon (BC) was characterized by three complementary techniques - incandescence (single particle soot photometer, SP2, at Parque Morelos), light absorption (cavity ringdown spectrometer with integrating nephelometer, CRDS-Neph, at Parque Morelos and Aethalometers at seven locations), and volatility (volatility tandem differential mobility analyzer, V-TDMA) during the Cal-Mex 2010 campaign. SP2, CRDS-Neph, and Aethalometer measurements characterized the BC mass, and SP2 and V-TDMA measurements also quantified BC-containing particle number, from which mass-mean BC diameters were calculated. On average, the mass concentrations measured in Tijuana (1.8 ± 2.6 μg m-3 at Parque Morelos and 2.6 μg m-3 in other regions of Tijuana) were higher than in San Diego or the international border crossing (0.5 ± 0.6 μg m-3). The observed BC mass concentrations were attributable to nighttime urban burning activities and diesel vehicles, both from the local (Baja California) and transported (Southern California) diesel vehicle fleets. Comparisons of the SP2 and co-located Aethalometers indicated that the two methods measured similar variations in BC mass concentrations (correlation coefficients greater than 0.85), and the mass concentrations were similar for the BC particles identified from nighttime urban burning sources. When the BC source changed to diesel vehicle emissions, the SP2 mass concentrations were lower than the Aethalometer mass concentrations by about 50%, likely indicating a change in the mass absorption efficiency and quantification by the Aethalometers. At Parque Morelos there were up to three different-sized modes of BC mass in particles: one mode below 100 nm, one near 100 nm, and another between 200 and 300 nm. The mode between 200 and 300 nm was associated with urban burning activities that influenced the site during evening hours. When backtrajectories indicated that airmasses came from the south to the Parque Morelos site, BC mass in particles was also larger (mass median diameter of 170 nm rather than 155 nm), consistent with the higher fraction of older diesel vehicles in the Tijuana fleet compared to the vehicles found in southern California.

Characteristics of breast cancer in Central China, literature review and comparison with USA.

PubMed

Chen, Chuang; Sun, Si; Yuan, Jing-Ping; Wang, Yao-Huai; Cao, Tian-Ze; Zheng, Hong-Mei; Jiang, Xue-Qing; Gong, Yi-Ping; Tu, Yi; Yao, Feng; Hu, Ming-Bai; Li, Juan-Juan; Sun, Sheng-Rong; Wei, Wen

2016-12-01

This work was to analyze characteristics of breast cancer (BC) in Central China, summarize main characteristics in China and compare with USA. BC main characteristics from four hospitals in Central China from 2002 to 2012 were collected and analyzed. All the single and large-scale clinical reports covering at least ten years were selected and summarized to calculate the BC characteristics of China. BC Characteristics in USA were selected based on the database from Surveillance, Epidemiology, and End Results (SEER) Program. Age distribution in Central China was normal with one age peak at 45-49 years, displaying differences from USA and Chinese American with two age peaks. BC characteristics in Central China displayed distinct features from USA and Chinese American, including significant younger onset age, lower proportion of patients with stage I, lymph node negative, small tumor size and ER positive. A total ten long-term and large-scale clinical reports were selected for BC characteristics of Mainland China analysis. A total of 53,571 BC patients were enrolled from 1995 to 2012. The main characteristics of BC in Mainland China were similar as that in Central China, but were significant different from developed regions of China (Hong Kong and Taiwan), USA and Chinese American. BC characteristics in Central China displayed representative patterns of Mainland China, while showed distinct patterns from Chinese patients in other developed areas and USA. Copyright © 2016 Elsevier Ltd. All rights reserved.

Body size in early life and risk of breast cancer.

PubMed

Shawon, Md Shajedur Rahman; Eriksson, Mikael; Li, Jingmei

2017-07-21

Body size in early life is inversely associated with adult breast cancer (BC) risk, but it is unclear whether the associations differ by tumor characteristics. In a pooled analysis of two Swedish population-based studies consisting of 6731 invasive BC cases and 28,705 age-matched cancer-free controls, we examined the associations between body size in early life and BC risk. Self-reported body sizes at ages 7 and 18 years were collected by a validated nine-level pictogram (aggregated into three categories: small, medium and large). Odds ratios (OR) and corresponding 95% confidence intervals (CI) were estimated from multivariable logistic regression models in case-control analyses, adjusting for study, age at diagnosis, age at menarche, number of children, hormone replacement therapy, and family history of BC. Body size change between ages 7 and 18 were also examined in relation to BC risk. Case-only analyses were performed to test whether the associations differed by tumor characteristics. Medium or large body size at age 7 and 18 was associated with a statistically significant decreased BC risk compared to small body size (pooled OR (95% CI): comparing large to small, 0.78 (0.70-0.86), P trend <0.001 and 0.72 (0.64-0.80), P trend <0.001, respectively). The majority of the women (~85%) did not change body size categories between age 7 and 18 . Women who remained medium or large between ages 7 and 18 had significantly decreased BC risk compared to those who remained small. A reduction in body size between ages 7 and 18 was also found to be inversely associated with BC risk (0.90 (0.81-1.00)). No significant association was found between body size at age 7 and tumor characteristics. Body size at age 18 was found to be inversely associated with tumor size (P trend  = 0.006), but not estrogen receptor status and lymph node involvement. For all analyses, the overall inferences did not change appreciably after further adjustment for adult body mass index. Our data provide further support for a strong and independent inverse relationship between early life body size and BC risk. The association between body size at age 18 and tumor size could be mediated by mammographic density.

Macroporous Carbon Supported Zerovalent Iron for Remediation of Trichloroethylene

DOE PAGES

Lawrinenko, Michael; Wang, Zhuangji; Horton, Robert; ...

2016-12-26

Groundwater contamination with chlorinated hydrocarbons has become a widespread problem that threatens water quality and human health. Permeable reactive barriers (PRBs), which employ zerovalent iron, are effective for remediation; however, a need exists to reduce the economic and environmental costs associated with constructing PRBs. Here, we present a method to produce zerovalent iron supported on macroporous carbon using only lignin and magnetite. Biochar- ZVI (BC-ZVI) produced by this method exhibits a broad pore size distribution with micrometer sized ZVI phases dispersed throughout a carbon matrix. X-ray diffraction revealed that pyrolysis at 900 °C of a 50/50 lignin$-$magnetite mixture resulted inmore » almost complete reduction of magnetite to ZVI and that compression molding promotes iron reduction in pyrolysis due to mixing of starting materials. High temperature pyrolysis of lignin yields some graphite in BC-ZVI due to reduction of carbonaceous gases on iron oxides. TCE was removed from water as it passed through a column packed with BC-ZVI at flow rates representative of average and high groundwater flow. Lastly, one-dimensional convection$-$dispersion modeling revealed that adsorption by biochar influences TCE transport and that BC-ZVI facilitated removal of TCE from contaminated water by both adsorption and degradation.« less

Climate Impacts of CALIPSO-Guided Corrections to Black Carbon Aerosol Vertical Distributions in a Global Climate Model

NASA Astrophysics Data System (ADS)

Kovilakam, Mahesh; Mahajan, Salil; Saravanan, R.; Chang, Ping

2017-10-01

We alleviate the bias in the tropospheric vertical distribution of black carbon aerosols (BC) in the Community Atmosphere Model (CAM4) using the Cloud-Aerosol and Infrared Pathfinder Satellite Observations (CALIPSO)-derived vertical profiles. A suite of sensitivity experiments are conducted with 1x, 5x, and 10x the present-day model estimated BC concentration climatology, with (corrected, CC) and without (uncorrected, UC) CALIPSO-corrected BC vertical distribution. The globally averaged top of the atmosphere radiative flux perturbation of CC experiments is ˜8-50% smaller compared to uncorrected (UC) BC experiments largely due to an increase in low-level clouds. The global average surface temperature increases, the global average precipitation decreases, and the ITCZ moves northward with the increase in BC radiative forcing, irrespective of the vertical distribution of BC. Further, tropical expansion metrics for the poleward extent of the Northern Hemisphere Hadley cell (HC) indicate that simulated HC expansion is not sensitive to existing model biases in BC vertical distribution.

The atmospheric lifetime of black carbon

NASA Astrophysics Data System (ADS)

Cape, J. N.; Coyle, M.; Dumitrean, P.

2012-11-01

Black carbon (BC) in the atmosphere contributes to the human health effects of particulate matter and contributes to radiative forcing of climate. The lifetime of BC, particularly the smaller particle sizes (PM2.5) which can be transported over long distances, is therefore an important factor in determining the range of such effects, and the spatial footprint of emission controls. Theory and models suggest that the typical lifetime of BC is around one week. The frequency distributions of measurements of a range of hydrocarbons at a remote rural site in southern Scotland (Auchencorth Moss) between 2007 and 2010 have been used to quantify the relationship between atmospheric lifetime and the geometric standard deviation of observed concentration. The analysis relies on an assumed common major emission source for hydrocarbons and BC, namely diesel-engined vehicles. The logarithm of the standard deviation of the log-transformed concentration data is linearly related to hydrocarbon lifetime, and the same statistic for BC can be used to assess the lifetime of BC relative to the hydrocarbons. Annual average data show BC lifetimes in the range 4-12 days, for an assumed OH concentration of 7 × 105 cm-3. At this site there is little difference in BC lifetime between winter and summer, despite a 3-fold difference in relative hydrocarbon lifetimes. This observation confirms the role of wet deposition as an important removal process for BC, as there is no difference in precipitation between winter and summer at this site. BC lifetime was significantly greater in 2010, which had 23% less rainfall than the preceding 3 years.

Using Combustion Tracers to Estimate Surface Black Carbon Distributions in WRF-Chem

NASA Astrophysics Data System (ADS)

Raman, A.; Arellano, A. F.

2015-12-01

Black Carbon (BC) emissions significantly affect the global and regional climate, air quality, and human health. However, BC observations are currently limited in space and time; leading to considerable uncertainties in the estimates of BC distribution from regional and global models. Here, we investigate the usefulness of carbon monoxide (CO) in quantifying BC across continental United States (CONUS). We use high resolution EPA AQS observations of CO and IMPROVE BC to estimate BC/CO ratios. We model the BC and CO distribution using the community Weather Research and Forecasting model with Chemistry (WRF-Chem). We configured WRF-Chem using MOZART chemistry, NEI 2005, MEGAN, and FINNv1.5 for anthropogenic, biogenic and fire emissions, respectively. In this work, we address the following three key questions: 1) What are the discrepancies in the estimates of BC and CO distributions across CONUS during summer and winter periods?, 2) How do BC/CO ratios change for different spatial and temporal regimes?, 3) Can we get better estimates of BC from WRF-Chem if we use BC/CO ratios along with optimizing CO concentrations? We compare ratios derived from the model and observations and develop characteristic ratios for several geographical and temporal regimes. We use an independent set of measurements of BC and CO to evaluate these ratios. Finally, we use a Bayesian synthesis inversion to optimize CO from WRF-Chem using regionally tagged CO tracers. We multiply the characteristic ratios we derived with the optimized CO to obtain BC distributions. Our initial results suggest that the maximum ratios of BC versus CO occur in the western US during the summer (average: 4 ng/m3/ppbv) and in the southeast during the winter (average: 5 ng/m3/ppbv). However, we find that these relationships vary in space and time and are highly dependent on fuel usage and meteorology. We find that optimizing CO using EPA-AQS provides improvements in BC but only over areas where BC/CO ratios are close to observed values.Black Carbon (BC) emissions significantly affect the global and regional climate, air quality, and human health. However, BC observations are currently limited in space and time; leading to considerable uncertainties in the estimates of BC distribution from regional and global models. Here, we investigate the usefulness of carbon monoxide (CO) in quantifying BC across continental United States (CONUS). We use high resolution EPA AQS observations of CO and IMPROVE BC to estimate BC/CO ratios. We model the BC and CO distribution using the community Weather Research and Forecasting model with Chemistry (WRF-Chem). We configured WRF-Chem using MOZART chemistry, NEI 2005, MEGAN, and FINNv1.5 for anthropogenic, biogenic and fire emissions, respectively. In this work, we address the following three key questions: 1) What are the discrepancies in the estimates of BC and CO distributions across CONUS during summer and winter periods?, 2) How do BC/CO ratios change for different spatial and temporal regimes?, 3) Can we get better estimates of BC from WRF-Chem if we use BC/CO ratios along with optimizing CO concentrations? We compare ratios derived from the model and observations and develop characteristic ratios for several geographical and temporal regimes. We use an independent set of measurements of BC and CO to evaluate these ratios. Finally, we use a Bayesian synthesis inversion to optimize CO from WRF-Chem using regionally tagged CO tracers. We multiply the characteristic ratios we derived with the optimized CO to obtain BC distributions. Our initial results suggest that the maximum ratios of BC versus CO occur in the western US during the summer (average: 4 ng/m3/ppbv) and in the southeast during the winter (average: 5 ng/m3/ppbv). However, we find that these relationships vary in space and time and are highly dependent on fuel usage and meteorology. We find that optimizing CO using EPA-AQS provides improvements in BC but only over areas where BC/CO ratios are close to observed values.

Transport of dissolved organic matter in Boom Clay: Size effects

NASA Astrophysics Data System (ADS)

Durce, D.; Aertsens, M.; Jacques, D.; Maes, N.; Van Gompel, M.

2018-01-01

A coupled experimental-modelling approach was developed to evaluate the effects of molecular weight (MW) of dissolved organic matter (DOM) on its transport through intact Boom Clay (BC) samples. Natural DOM was sampled in-situ in the BC layer. Transport was investigated with percolation experiments on 1.5 cm BC samples by measuring the outflow MW distribution (MWD) by size exclusion chromatography (SEC). A one-dimensional reactive transport model was developed to account for retardation, diffusion and entrapment (attachment and/or straining) of DOM. These parameters were determined along the MWD by implementing a discretisation of DOM into several MW points and modelling the breakthrough of each point. The pore throat diameter of BC was determined as 6.6-7.6 nm. Below this critical size, transport of DOM is MW dependent and two major types of transport were identified. Below MW of 2 kDa, DOM was neither strongly trapped nor strongly retarded. This fraction had an averaged capacity factor of 1.19 ± 0.24 and an apparent dispersion coefficient ranging from 7.5 × 10- 11 to 1.7 × 10- 11 m2/s with increasing MW. DOM with MW > 2 kDa was affected by both retardation and straining that increased significantly with increasing MW while apparent dispersion coefficients decreased. Values ranging from 1.36 to 19.6 were determined for the capacity factor and 3.2 × 10- 11 to 1.0 × 10- 11 m2/s for the apparent dispersion coefficient for species with 2.2 kDa < MW < 9.3 kDa. Straining resulted in an immobilisation of in average 49 ± 6% of the injected 9.3 kDa species. Our findings show that an accurate description of DOM transport requires the consideration of the size effects.

Sparse targets in hydroacoustic surveys: Balancing quantity and quality of in situ target strength data

USGS Publications Warehouse

DuFour, Mark R.; Mayer, Christine M.; Kocovsky, Patrick; Qian, Song; Warner, David M.; Kraus, Richard T.; Vandergoot, Christopher

2017-01-01

Hydroacoustic sampling of low-density fish in shallow water can lead to low sample sizes of naturally variable target strength (TS) estimates, resulting in both sparse and variable data. Increasing maximum beam compensation (BC) beyond conventional values (i.e., 3 dB beam width) can recover more targets during data analysis; however, data quality decreases near the acoustic beam edges. We identified the optimal balance between data quantity and quality with increasing BC using a standard sphere calibration, and we quantified the effect of BC on fish track variability, size structure, and density estimates of Lake Erie walleye (Sander vitreus). Standard sphere mean TS estimates were consistent with theoretical values (−39.6 dB) up to 18-dB BC, while estimates decreased at greater BC values. Natural sources (i.e., residual and mean TS) dominated total fish track variation, while contributions from measurement related error (i.e., number of single echo detections (SEDs) and BC) were proportionally low. Increasing BC led to more fish encounters and SEDs per fish, while stability in size structure and density were observed at intermediate values (e.g., 18 dB). Detection of medium to large fish (i.e., age-2+ walleye) benefited most from increasing BC, as proportional changes in size structure and density were greatest in these size categories. Therefore, when TS data are sparse and variable, increasing BC to an optimal value (here 18 dB) will maximize the TS data quantity while limiting lower-quality data near the beam edges.

Climate Impacts of CALIPSO-Guided Corrections to Black Carbon Aerosol Vertical Distributions in a Global Climate Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kovilakam, Mahesh; Mahajan, Salil; Saravanan, R.

Here, we alleviate the bias in the tropospheric vertical distribution of black carbon aerosols (BC) in the Community Atmosphere Model (CAM4) using the Cloud-Aerosol and Infrared Pathfinder Satellite Observations (CALIPSO)-derived vertical profiles. A suite of sensitivity experiments are conducted with 1x, 5x, and 10x the present-day model estimated BC concentration climatology, with (corrected, CC) and without (uncorrected, UC) CALIPSO-corrected BC vertical distribution. The globally averaged top of the atmosphere radiative flux perturbation of CC experiments is ~8–50% smaller compared to uncorrected (UC) BC experiments largely due to an increase in low-level clouds. The global average surface temperature increases, the globalmore » average precipitation decreases, and the ITCZ moves northward with the increase in BC radiative forcing, irrespective of the vertical distribution of BC. Further, tropical expansion metrics for the poleward extent of the Northern Hemisphere Hadley cell (HC) indicate that simulated HC expansion is not sensitive to existing model biases in BC vertical distribution.« less

Climate Impacts of CALIPSO-Guided Corrections to Black Carbon Aerosol Vertical Distributions in a Global Climate Model

DOE PAGES

Kovilakam, Mahesh; Mahajan, Salil; Saravanan, R.; ...

2017-09-13

Here, we alleviate the bias in the tropospheric vertical distribution of black carbon aerosols (BC) in the Community Atmosphere Model (CAM4) using the Cloud-Aerosol and Infrared Pathfinder Satellite Observations (CALIPSO)-derived vertical profiles. A suite of sensitivity experiments are conducted with 1x, 5x, and 10x the present-day model estimated BC concentration climatology, with (corrected, CC) and without (uncorrected, UC) CALIPSO-corrected BC vertical distribution. The globally averaged top of the atmosphere radiative flux perturbation of CC experiments is ~8–50% smaller compared to uncorrected (UC) BC experiments largely due to an increase in low-level clouds. The global average surface temperature increases, the globalmore » average precipitation decreases, and the ITCZ moves northward with the increase in BC radiative forcing, irrespective of the vertical distribution of BC. Further, tropical expansion metrics for the poleward extent of the Northern Hemisphere Hadley cell (HC) indicate that simulated HC expansion is not sensitive to existing model biases in BC vertical distribution.« less

75 FR 16513 - B&C Corporation, JR Engineering Division, Including B&C Distribution Center, Including On-Site...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-01

... Engineering Division, Including B&C Distribution Center, Including On-Site Leased Workers From B&C Services, Inc., Barberton, OH; Amended Certification Regarding Eligibility To Apply for Worker Adjustment... Department of Labor issued a Certification of Eligibility to Apply for Worker Adjustment Assistance on...

Laser Intensity Scaling Through Stimulated Scattering in Optical Fibers

DTIC Science & Technology

2001-12-17

Stokes beams transmitted through a 300 m multimode fiber. ..................................127 Figure 58: Circles (squares) indicate the measured size...circles) and first order Stokes (squares) beams at the fiber facet. (b,c) Pump (left) and Stokes (right) intensity distributions for a 300 m and...75 m fiber respectively. .......................................................................................130 Figure 61: Double clad fiber

A Year-round Observation of Size Distribution of Aerosol Particles at the Cape Ochiishi, Japan

NASA Astrophysics Data System (ADS)

Miura, K.; Mukai, H.; Hashimoto, S.; Uematsu, M.

2010-12-01

New particle formation by nucleation of gas-phase compounds emitted from marine biogenic sources is very important for climate change. To clarify the mechanism of the formation, size distributions of submicron aerosols have been measured at the Cape Ochiishi, facing the North Western Pacific Ocean where primary productivity is high. A test observation was done from 22nd May to 18th June 2008 and a year-round observation has been performed from 16th October 2009 to 7th September 2010. The size distribution from 10 nm to 487 nm in diameter was measured with a scanning mobility particle sizer (SMPS, TSI 3034). Sample air was dried to lower than 40%. Transport of sulfate, organic carbon (OC), and black carbon (BC) was estimated with Chemical weather FORecasting System (CFORS), developed by Prof. Uno, Kyushu University, Japan. Existence of inversion layer was estimated with temperature profile measured at surface, 10m, 30m, and 50m in altitude. The burst of the particles smaller than 20nm in diameter continuing longer than 3 hrs was observed ten times until 3rd November 2009. Two were observed in early summer and the other was in autumn. Banana shape was faintly observed five times. Transport of sulfate, OC, and BC was observed 3, 8, 9 times, respectively. Source of air mass was estimated with these elements, weather map, and wind direction. Five air masses were estimated to continental. Clearly nucleation related to marine sources was not observed. The size distribution of burst evens of maritime and continental air mass showed the shift of mode to larger diameter. Strong inversion of temperature was observed once. The value of size distribution did not show high. Minimum value of size distribution was observed in the strong rain on 27th October. Acknowledgments This study was partly supported by the Grant-in-Aids for Scientific Research on Priority Areas from the Ministry of Education, Culture, Sports, Science and Technology, Japan (18067005). The observation was performed at the monitoring station of the National Institute for Environmental Studies.

Impact of Snow Grain Shape and Internal Mixing with Black Carbon Aerosol on Snow Optical Properties for use in Climate Models

NASA Astrophysics Data System (ADS)

He, C.; Liou, K. N.; Takano, Y.; Yang, P.; Li, Q.; Chen, F.

2017-12-01

A set of parameterizations is developed for spectral single-scattering properties of clean and black carbon (BC)-contaminated snow based on geometric-optic surface-wave (GOS) computations, which explicitly resolves BC-snow internal mixing and various snow grain shapes. GOS calculations show that, compared with nonspherical grains, volume-equivalent snow spheres show up to 20% larger asymmetry factors and hence stronger forward scattering, particularly at wavelengths <1 mm. In contrast, snow grain sizes have a rather small impact on the asymmetry factor at wavelengths <1 mm, whereas size effects are important at longer wavelengths. The snow asymmetry factor is parameterized as a function of effective size, aspect ratio, and shape factor, and shows excellent agreement with GOS calculations. According to GOS calculations, the single-scattering coalbedo of pure snow is predominantly affected by grain sizes, rather than grain shapes, with higher values for larger grains. The snow single-scattering coalbedo is parameterized in terms of the effective size that combines shape and size effects, with an accuracy of >99%. Based on GOS calculations, BC-snow internal mixing enhances the snow single-scattering coalbedo at wavelengths <1 mm, but it does not alter the snow asymmetry factor. The BC-induced enhancement ratio of snow single-scattering coalbedo, independent of snow grain size and shape, is parameterized as a function of BC concentration with an accuracy of >99%. Overall, in addition to snow grain size, both BC-snow internal mixing and snow grain shape play critical roles in quantifying BC effects on snow optical properties. The present parameterizations can be conveniently applied to snow, land surface, and climate models including snowpack radiative transfer processes.

Spatiotemporal Co-existence of Female Thyroid and Breast Cancers in Hangzhou, China

NASA Astrophysics Data System (ADS)

Fei, Xufeng; Christakos, George; Lou, Zhaohan; Ren, Yanjun; Liu, Qingmin; Wu, Jiaping

2016-06-01

Thyroid and breast cancers (TC, BC) are common female malignant tumors worldwide. Studies suggest that TC patients have a higher BC risk, and vice versa. However, it has not been investigated quantitatively if there is an association between the space-time TC and BC incidence distributions at the population level. This work aims to answer this question. 5358 TC and 8784 BC (female) cases were diagnosed in Hangzhou (China, 2008-2012). Pearson and Spearman rank correlation coefficients of the TC and BC incidences were high, and their patterns were geographically similar. The spatiotemporal co-existence of TC and BC distributions was investigated using the integrative disease predictability (IDP) criterion: if TC-BC association is part of the disease mapping knowledge bases, it should yield improved space-time incidence predictions. Improved TC (BC) incidence predictions were generated when integrating both TC and BC data than when using only TC (BC) data. IDP consistently demonstrated the spatiotemporal co-existence of TC and BC distributions throughout Hangzhou (2008-2012), which means that when the population experiences high incidences of one kind of cancer attention should be paid to the other kind of cancer too. The strength of TC-BC association was measured by the IDP coefficients and incidence prediction accuracy.

Spatiotemporal Co-existence of Female Thyroid and Breast Cancers in Hangzhou, China

PubMed Central

Fei, Xufeng; Christakos, George; Lou, Zhaohan; Ren, Yanjun; Liu, Qingmin; Wu, Jiaping

2016-01-01

Thyroid and breast cancers (TC, BC) are common female malignant tumors worldwide. Studies suggest that TC patients have a higher BC risk, and vice versa. However, it has not been investigated quantitatively if there is an association between the space-time TC and BC incidence distributions at the population level. This work aims to answer this question. 5358 TC and 8784 BC (female) cases were diagnosed in Hangzhou (China, 2008–2012). Pearson and Spearman rank correlation coefficients of the TC and BC incidences were high, and their patterns were geographically similar. The spatiotemporal co-existence of TC and BC distributions was investigated using the integrative disease predictability (IDP) criterion: if TC-BC association is part of the disease mapping knowledge bases, it should yield improved space-time incidence predictions. Improved TC (BC) incidence predictions were generated when integrating both TC and BC data than when using only TC (BC) data. IDP consistently demonstrated the spatiotemporal co-existence of TC and BC distributions throughout Hangzhou (2008–2012), which means that when the population experiences high incidences of one kind of cancer attention should be paid to the other kind of cancer too. The strength of TC-BC association was measured by the IDP coefficients and incidence prediction accuracy. PMID:27341638

Enhanced Solar Energy Absorption by Internally-mixed Black Carbon in Snow Grains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flanner, M. G.; Liu, Xiaohong; Zhou, Cheng

2012-05-30

Here we explore light absorption by snowpack containing black carbon (BC) particles residing within ice grains. Basic considerations of particle volumes and BC/snow mass concentrations show that there are generally 0:05-109 BC particles for each ice grain. This suggests that internal BC is likely distributed as multiple inclusions within ice grains, and thus the dynamic effective medium approximation (DEMA) (Chylek and Srivastava, 1983) is a more appropriate optical representation for BC/ice composites than coated-sphere or standard mixing approximations. DEMA calculations show that the 460 nm absorption cross-section of BC/ice composites, normalized to the mass of BC, is typically enhanced bymore » factors of 1.8-2.1 relative to interstitial BC. BC effective radius is the dominant cause of variation in this enhancement, compared with ice grain size and BC volume fraction. We apply two atmospheric aerosol models that simulate interstitial and within-hydrometeor BC lifecycles. Although only {approx}2% of the atmospheric BC burden is cloud-borne, 71-83% of the BC deposited to global snow and sea-ice surfaces occurs within hydrometeors. Key processes responsible for within-snow BC deposition are development of hydrophilic coatings on BC, activation of liquid droplets, and subsequent snow formation through riming or ice nucleation by other species and aggregation/accretion of ice particles. Applying deposition fields from these aerosol models in offline snow and sea-ice simulations, we calculate that 32-73% of BC in global surface snow resides within ice grains. This fraction is smaller than the within-hydrometeor deposition fraction because meltwater flux preferentially removes internal BC, while sublimation and freezing within snowpack expose internal BC. Incorporating the DEMA into a global climate model, we simulate increases in BC/snow radiative forcing of 43-86%, relative to scenarios that apply external optical properties to all BC. We show that snow metamorphism driven by diffusive vapor transfer likely proceeds too slowly to alter the mass of internal BC while it is radiatively active, but neglected processes like wind pumping and convection may play much larger roles. These results suggest that a large portion of BC in surface snowpack may reside within ice grains and increase BC/snow radiative forcing, although measurements to evaluate this are lacking. Finally, previous studies of BC/snow forcing that neglected this absorption enhancement are not necessarily biased low, because of application of absorption-enhancing sulfate coatings to hydrophilic BC, neglect of coincident absorption by dust in snow, and implicit treatment of cloud-borne BC resulting in longer-range transport.« less

Vertical profiles of BC direct radiative effect over Italy: high vertical resolution data and atmospheric feedbacks

NASA Astrophysics Data System (ADS)

Močnik, Griša; Ferrero, Luca; Castelli, Mariapina; Ferrini, Barbara S.; Moscatelli, Marco; Grazia Perrone, Maria; Sangiorgi, Giorgia; Rovelli, Grazia; D'Angelo, Luca; Moroni, Beatrice; Scardazza, Francesco; Bolzacchini, Ezio; Petitta, Marcello; Cappelletti, David

2016-04-01

Black carbon (BC), and its vertical distribution, affects the climate. Global measurements of BC vertical profiles are lacking to support climate change research. To fill this gap, a campaign was conducted over three Italian basin valleys, Terni Valley (Appennines), Po Valley and Passiria Valley (Alps), to characterize the impact of BC on the radiative budget under similar orographic conditions. 120 vertical profiles were measured in winter 2010. The BC vertical profiles, together with aerosol size distribution, aerosol chemistry and meteorological parameters, have been determined using a tethered balloon-based platform equipped with: a micro-Aethalometer AE51 (Magee Scientific), a 1.107 Grimm OPC (0.25-32 μm, 31 size classes), a cascade impactor (Siuotas SKC), and a meteorological station (LSI-Lastem). The aerosol chemical composition was determined from collected PM2.5 samples. The aerosol absorption along the vertical profiles was measured and optical properties calculated using the Mie theory applied to the aerosol size distribution. The aerosol optical properties were validated with AERONET data and then used as inputs to the radiative transfer model libRadtran. Vertical profiles of the aerosol direct radiative effect, the related atmospheric absorption and the heating rate were calculated. Vertical profile measurements revealed some common behaviors over the studied basin valleys. From below the mixing height to above it, a marked concentration drop was found for both BC (from -48.4±5.3% up to -69.1±5.5%) and aerosol number concentration (from -23.9±4.3% up to -46.5±7.3%). These features reflected on the optical properties of the aerosol. Absorption and scattering coefficients decreased from below the MH to above it (babs from -47.6±2.5% up to -71.3±3.0% and bsca from -23.5±0.8% up to -61.2±3.1%, respectively). Consequently, the Single Scattering Albedo increased above the MH (from +4.9±2.2% to +7.4±1.0%). The highest aerosol absorption was observed below the MH. The radiative power density absorbed into each atmospheric layer was normalized by the layer height to compare measurements taken at different sites with different vertical resolutions. The atmospheric absorption of radiative power below the MH ranged from +45.2±5.1 mW/m3 up to +103.3±16.2 mW/m3 and was ~2-3 times higher than above MH. The resulting heating rate was characterized by a vertical negative gradient with increasing height, from -2.6±0.2 K/(day km) up to -8.3±1.2 K/(day km), exerting a negative feedback on the atmospheric stability over basin valleys, weakening the ground-based thermal inversions and increasing the dispersal conditions.

Variations of aerosol size distribution, chemical composition and optical properties from roadside to ambient environment: A case study in Hong Kong, China

NASA Astrophysics Data System (ADS)

Zhang, Qian; Ning, Zhi; Shen, Zhenxing; Li, Guoliang; Zhang, Junke; Lei, Yali; Xu, Hongmei; Sun, Jian; Zhang, Leiming; Westerdahl, Dane; Gali, Nirmal Kumar; Gong, Xuesong

2017-10-01

This study investigated the ;roadside-to-ambient; evolution of particle physicochemical and optical properties in typical urban atmospheres of Hong Kong through collection of chemically-resolved PM2.5 data and PM2.5 size distribution at a roadside and an ambient site. Roadside particle size distribution showed typical peaks in the nuclei mode (30-40 nm) while ambient measurements peaked in the Aitken mode (50-70 nm), revealing possible condensation and coagulation growth of freshly emitted particles during aging processes. Much higher levels of anthropogenic chemical components, i.e. nitrate, sulfate, ammonium, organic carbon (OC) and elemental carbon (EC), but lower levels of OC/EC and secondary inorganic aerosols (SIA)/EC ratios appeared in roadside than ambient particles. The high OC/EC and SIA/EC ratios in ambient particles implied high contributions from secondary aerosols. Black carbon (BC), a strong light absorbing material, showed large variations in optical properties when mixed with other inorganic and organic components. Particle-bound polycyclic aromatic hydrocarbons (p-PAHs), an indicator of brown carbon (BrC), showed significant UV-absorbing ability. The average BC and p-PAHs concentrations were 3.8 and 87.6 ng m-3, respectively, at the roadside, but were only 1.5 and 18.1 ng m-3 at the ambient site, suggesting BC and p-PAHs concentrations heavily driven by traffic emissions. In contrast, PM2.5 UV light absorption coefficients (babs-BrC,370nm) at the ambient site (4.2 Mm-1) and at the roadside site (4.1 Mm-1) were similar, emphasizing that particle aging processes enhanced UV light-absorbing properties, a conclusion that was also supported by the finding that the Absorption Ångström coefficient (AAC) value at UV wavelengths (AAC_UV band) at the ambient site were ∼1.7 times higher than that at the roadside. Both aqueous reaction and photochemically produced secondary organic aerosol (SOA) for ambient aerosols contributed to the peak values of babs-BrC,370nm in ambient particles at midnight and around noon, highlighting that secondary BrC had different sources and particle aging in the atmosphere affected BrC and BC properties and related aerosol light absorption.

Improvement and comparison of likelihood functions for model calibration and parameter uncertainty analysis within a Markov chain Monte Carlo scheme

NASA Astrophysics Data System (ADS)

Cheng, Qin-Bo; Chen, Xi; Xu, Chong-Yu; Reinhardt-Imjela, Christian; Schulte, Achim

2014-11-01

In this study, the likelihood functions for uncertainty analysis of hydrological models are compared and improved through the following steps: (1) the equivalent relationship between the Nash-Sutcliffe Efficiency coefficient (NSE) and the likelihood function with Gaussian independent and identically distributed residuals is proved; (2) a new estimation method of the Box-Cox transformation (BC) parameter is developed to improve the effective elimination of the heteroscedasticity of model residuals; and (3) three likelihood functions-NSE, Generalized Error Distribution with BC (BC-GED) and Skew Generalized Error Distribution with BC (BC-SGED)-are applied for SWAT-WB-VSA (Soil and Water Assessment Tool - Water Balance - Variable Source Area) model calibration in the Baocun watershed, Eastern China. Performances of calibrated models are compared using the observed river discharges and groundwater levels. The result shows that the minimum variance constraint can effectively estimate the BC parameter. The form of the likelihood function significantly impacts on the calibrated parameters and the simulated results of high and low flow components. SWAT-WB-VSA with the NSE approach simulates flood well, but baseflow badly owing to the assumption of Gaussian error distribution, where the probability of the large error is low, but the small error around zero approximates equiprobability. By contrast, SWAT-WB-VSA with the BC-GED or BC-SGED approach mimics baseflow well, which is proved in the groundwater level simulation. The assumption of skewness of the error distribution may be unnecessary, because all the results of the BC-SGED approach are nearly the same as those of the BC-GED approach.

Interparticle interactions mediated superspin glass to superferromagnetic transition in Ni-bacterial cellulose aerogel nanocomposites

NASA Astrophysics Data System (ADS)

Thiruvengadam, V.; Vitta, Satish

2016-06-01

The interparticle interactions in the magnetic nanocomposites play a dominant role in controlling phase transitions: superparamagnetic to superspin glass and to superferromagnetic. These interactions can be tuned by controlling the size and number density of nanoparticles. The aerogel composites, 0.3Ni-BC and 0.7Ni-BC, consisting of Ni nanoparticles distributed in the bacterial cellulose have been used as a model system to study these interactions. Contrary to conventional approach, size of Ni-nanoparticles is not controlled and allowed to form naturally in bacterial cellulose template. The uncontrolled growth of Ni results in the formation of nanoparticles with 3 different size distributions - <10 nm particles along the length of fibrils, 50 nm particles in the intermediate spaces between the fibrils, and >100 nm particles in voids formed by reticulate structure. At room temperature, the composites exhibit a weakly ferromagnetic behaviour with a coercivity of 40 Oe, which increases to 160 Oe at 10 K. The transition from weakly ferromagnetic state to superferromagnetic state at low temperatures is mediated by the superspin glass state at intermediate temperatures via the interparticle interactions aided by nanoparticles present along the length of fibres. A temperature dependent microstructural model has been developed to understand the magnetic behaviour of nanocomposite aerogels.

RICE ice core: Black Carbon reflects climate variability at Roosevelt Island, West Antarctica

NASA Astrophysics Data System (ADS)

Ellis, Aja; Edwards, Ross; Bertler, Nancy; Winton, Holly; Goodwin, Ian; Neff, Peter; Tuohy, Andrea; Proemse, Bernadette; Hogan, Chad; Feiteng, Wang

2015-04-01

The Roosevelt Island Climate Evolution (RICE) project successfully drilled a deep ice core from Roosevelt Island during the 2011/2012 and 2012/2013 seasons. Located in the Ross Ice Shelf in West Antarctica, the site is an ideal location for investigating climate variability and the past stability of the Ross Ice Shelf. Black carbon (BC) aerosols are emitted by both biomass burning and fossil fuels, and BC particles emitted in the southern hemisphere are transported in the atmosphere and preserved in Antarctic ice. The past record of BC is expected to be sensitive to climate variability, as it is modulated by both emissions and transport. To investigate BC variability over the past 200 years, we developed a BC record from two overlapping ice cores (~1850-2012) and a high-resolution snow pit spanning 2010-2012 (cal. yr). Consistent results are found between the snow pit profiles and ice core records. Distinct decadal trends are found with respect to BC particle size, and the record indicates a steady rise in BC particle size over the last 100 years. Differences in emission sources and conditions may be a possible explanation for changes in BC size. These records also show a significant increase in BC concentration over the past decade with concentrations rising over 1.5 ppb (1.5*10^-9 ng/g), suggesting a fundamental shift in BC deposition to the site.

Evaluating Model Parameterizations of Submicron Aerosol Scattering and Absorption with in situ Data from ARCTAS 2008

NASA Technical Reports Server (NTRS)

Alvarado, Matthew J.; Lonsdale, Chantelle R.; Macintyre, Helen L.; Bian, Huisheng; Chin, Mian; Ridley, David A.; Heald, Colette L.; Thornhill, Kenneth L.; Anderson, Bruce E.; Cubison, Michael J.;

Evaluating model parameterizations of submicron aerosol scattering and absorption with in situ data from ARCTAS 2008

NASA Astrophysics Data System (ADS)

Alvarado, Matthew J.; Lonsdale, Chantelle R.; Macintyre, Helen L.; Bian, Huisheng; Chin, Mian; Ridley, David A.; Heald, Colette L.; Thornhill, Kenneth L.; Anderson, Bruce E.; Cubison, Michael J.; Jimenez, Jose L.; Kondo, Yutaka; Sahu, Lokesh K.; Dibb, Jack E.; Wang, Chien

2016-07-01

Accurate modeling of the scattering and absorption of ultraviolet and visible radiation by aerosols is essential for accurate simulations of atmospheric chemistry and climate. Closure studies using in situ measurements of aerosol scattering and absorption can be used to evaluate and improve models of aerosol optical properties without interference from model errors in aerosol emissions, transport, chemistry, or deposition rates. Here we evaluate the ability of four externally mixed, fixed size distribution parameterizations used in global models to simulate submicron aerosol scattering and absorption at three wavelengths using in situ data gathered during the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign. The four models are the NASA Global Modeling Initiative (GMI) Combo model, GEOS-Chem v9-02, the baseline configuration of a version of GEOS-Chem with online radiative transfer calculations (called GC-RT), and the Optical Properties of Aerosol and Clouds (OPAC v3.1) package. We also use the ARCTAS data to perform the first evaluation of the ability of the Aerosol Simulation Program (ASP v2.1) to simulate submicron aerosol scattering and absorption when in situ data on the aerosol size distribution are used, and examine the impact of different mixing rules for black carbon (BC) on the results. We find that the GMI model tends to overestimate submicron scattering and absorption at shorter wavelengths by 10-23 %, and that GMI has smaller absolute mean biases for submicron absorption than OPAC v3.1, GEOS-Chem v9-02, or GC-RT. However, the changes to the density and refractive index of BC in GC-RT improve the simulation of submicron aerosol absorption at all wavelengths relative to GEOS-Chem v9-02. Adding a variable size distribution, as in ASP v2.1, improves model performance for scattering but not for absorption, likely due to the assumption in ASP v2.1 that BC is present at a constant mass fraction throughout the aerosol size distribution. Using a core-shell mixing rule in ASP overestimates aerosol absorption, especially for the fresh biomass burning aerosol measured in ARCTAS-B, suggesting the need for modeling the time-varying mixing states of aerosols in future versions of ASP.

Impact of breast cancer family history on tumor detection and tumor size in women newly-diagnosed with invasive breast cancer.

PubMed

Schwab, Fabienne Dominique; Bürki, Nicole; Huang, Dorothy Jane; Heinzelmann-Schwarz, Viola; Schmid, Seraina Margaretha; Vetter, Marcus; Schötzau, Andreas; Güth, Uwe

2014-03-01

This study evaluated the impact of family history (FH) on tumor detection, the patient's age and tumor size at diagnosis in breast cancer (BC). Furthermore, we investigated whether the impact of FH on these features was dependent on degree of relationship, number of relatives with a BC history, or the age of the affected relative at the time that her BC was diagnosed. Out of the entire cohort (n = 1,037), 244 patients (23.5%) had a positive FH; 159 (15.3%) had first-degree relatives affected with BC and 85 patients (8.2%) had second-degree affected relatives. Compared to women who had no BC-affected relatives, the tumors of women who had positive FH were more often found by radiological breast examination (RBE: 31.7%/27.2%, p = 0.008), and they were smaller (general tumor size: 21.8 mm/26.4 mm, p = 0.003; size of tumors found by breast self-examination (BSE): 26.1 mm/30.6 mm, p = 0.041). However, this positive effect of increased use of BC screening and smaller tumor sizes was only observed in patients whose first-degree relatives were affected (comparison with second-degree affected relatives: RBE: 43.8%/24.7%; odds ratio 2.38, p = 0.007; general tumor size: 19.3 mm/26.3 mm; mean difference (MD) -6.9, p = 0.025; tumor size found by BSE: 22.5 mm/31.0 mm; MD -8.5, p = 0.044). When more second-degree relatives or older relatives were diagnosed with BC, the tumors of these patients were similarly often detected by RBE (relationship: 24.7%/27.2%, p = 0.641; age: 33.7 %/27.2 %, p = 0.177) and had similar tumor sizes (general size: 26.3 mm/26.4 mm, p = 0.960; BSE: 31.0 mm/30.6 mm, p = 0.902) as those of women without a FH. Women with a positive FH generally use mammography screening more often and perceive changes in the breast earlier than women without such history. The increased awareness of BC risk decreases if the relationship is more distant.

Vertical profiles of aerosol absorption coefficient from micro-Aethalometer data and Mie calculation over Milan.

PubMed

Ferrero, L; Mocnik, G; Ferrini, B S; Perrone, M G; Sangiorgi, G; Bolzacchini, E

2011-06-15

Vertical profiles of aerosol number-size distribution and black carbon (BC) concentration were measured between ground-level and 500m AGL over Milan. A tethered balloon was fitted with an instrumentation package consisting of the newly-developed micro-Aethalometer (microAeth® Model AE51, Magee Scientific, USA), an optical particle counter, and a portable meteorological station. At the same time, PM(2.5) samples were collected both at ground-level and at a high altitude sampling site, enabling particle chemical composition to be determined. Vertical profiles and PM(2.5) data were collected both within and above the mixing layer. Absorption coefficient (b(abs)) profiles were calculated from the Aethalometer data: in order to do so, an optical enhancement factor (C), accounting for multiple light-scattering within the filter of the new microAeth® Model AE51, was determined for the first time. The value of this parameter C (2.05±0.03 at λ=880nm) was calculated by comparing the Aethalometer attenuation coefficient and aerosol optical properties determined from OPC data along vertical profiles. Mie calculations were applied to the OPC number-size distribution data, and the aerosol refractive index was calculated using the effective medium approximation applied to aerosol chemical composition. The results compare well with AERONET data. The BC and b(abs) profiles showed a sharp decrease at the mixing height (MH), and fairly constant values of b(abs) and BC were found above the MH, representing 17±2% of those values measured within the mixing layer. The BC fraction of aerosol volume was found to be lower above the MH: 48±8% of the corresponding ground-level values. A statistical mean profile was calculated, both for BC and b(abs), to better describe their behaviour; the model enabled us to compute their average behaviour as a function of height, thus laying the foundations for valid parametrizations of vertical profile data which can be useful in both remote sensing and climatic studies. Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of equal-channel angular pressing and annealing conditions on the texture, microstructure, and deformability of an MA2-1 alloy

NASA Astrophysics Data System (ADS)

Serebryany, V. N.; Ivanova, T. M.; Kopylov, V. I.; Dobatkin, S. V.; Pozdnyakova, N. N.; Pimenov, V. A.; Savelova, T. I.

2010-07-01

Equal-channel angular pressing (ECAP) of am MA2-1 alloy according to routes A and Bc is used to study the possibility of increasing the low-temperature deformability of the alloy due to grain refinement and a change in its texture. To separate the grain refinement effect from the effect of texture on the deformability of the alloy, samples after ECAP are subjected to recrystallization annealing that provides grain growth to the grain size characteristic of the initial state (IS) of the alloy. Upon ECAP, the average grain size is found to decrease to 2-2.4 μm and the initial sharp axial texture changes substantially (it decomposes into several scattered orientations). The type of orientations and the degree of their scattering depend on the type of ECAP routes. The detected change in the texture is accompanied by an increase in the deformability parameters (normal plastic anisotropy coefficient R, strain-hardening exponent n, relative uniform elongation δu) determined upon tensile tests at 20°C for the states of the alloy formed in the IS-4A-4Bc and IS-4Ao-4BcO sequences. The experimental values of R agree with the values calculated in terms of the Taylor model of plastic deformation in the Bishop-Hill approximation using quantitative texture data in the form of orientation distribution function coefficients with allowance for the activation of prismatic slip, especially for ECAP routes 4Bc and 4BcO. When the simulation results, the Hall-Petch relation, and the generalized Schmid factors are taken into account, a correlation is detected between the deformability parameter, the Hall-Petch coefficient, and the ratio of the critical shear stresses on prismatic and basal planes.

Near-Surface Refractory Black Carbon Observations in the Atmosphere and Snow in the McMurdo Dry Valleys, Antarctica, and Potential Impacts of Foehn Winds

NASA Astrophysics Data System (ADS)

Khan, Alia L.; McMeeking, Gavin R.; Schwarz, Joshua P.; Xian, Peng; Welch, Kathleen A.; Berry Lyons, W.; McKnight, Diane M.

2018-03-01

Measurements of light-absorbing particles in the boundary layer of the high southern latitudes are scarce, particularly in the McMurdo Dry Valleys (MDV), Antarctica. During the 2013-2014 austral summer near-surface boundary layer refractory black carbon (rBC) aerosols were measured in air by a single-particle soot photometer (SP2) at multiple locations in the MDV. Near-continuous rBC atmospheric measurements were collected at Lake Hoare Camp (LH) over 2 months and for several hours at more remote locations away from established field camps. We investigated periods dominated by both upvalley and downvalley winds to explore the causes of differences in rBC concentrations and size distributions. Snow samples were also collected in a 1 m pit on a glacier near the camp. The range of concentrations rBC in snow was 0.3-1.2 ± 0.3 μg-rBC/L-H2O, and total organic carbon was 0.3-1.4 ± 0.3 mg/L. The rBC concentrations measured in this snow pit are not sufficient to reduce surface albedo; however, there is potential for accumulation of rBC on snow and ice surfaces at low elevation throughout the MDV, which were not measured as part of this study. At LH, the average background rBC mass aerosol concentrations were 1.3 ng/m3. rBC aerosol mass concentrations were slightly lower, 0.09-1.3 ng/m3, at the most remote sites in the MDV. Concentration spikes as high as 200 ng/m3 were observed at LH, associated with local activities. During a foehn wind event, the average rBC mass concentration increased to 30-50 ng/m3. Here we show that the rBC increase could be due to resuspension of locally produced BC from generators, rocket toilets, and helicopters, which may remain on the soil surface until redistributed during high wind events. Quantification of local production and long-range atmospheric transport of rBC to the MDV is necessary for understanding the impacts of this species on regional climate.

A novel inversion method to calculate the mass fraction of coated refractory black carbon using a centrifugal particle mass analyzer and single particle soot photometer

NASA Astrophysics Data System (ADS)

Irwin, M.; Broda, K.; Olfert, J. S.; Schill, G. P.; McMeeking, G. R.; Schnitzler, E.; Jäger, W.

2016-12-01

Refractory black carbon (rBC) has important atmospheric impacts due to its ability to absorb light, and its interactions with light are partly governed by the acquisition of coatings or other mixing processes. Here, a novel inversion method is presented which derives the mass fraction of coated rBC using a coupled centrifugal particle mass analyzer (CPMA) and single particle soot photometer (SP2). The CPMA selects particles of a known mass-­to-­charge ratio, and the SP2 detects the mass of rBC in each individual particle. The results of the inversion are the simultaneous number distributions of both rBC mass and total particle mass. Practically, the distribution can be integrated to find properties of the total aerosol population, for example, i) mass fraction of coating and ii) mass of coating on a particle of known total mass. This was demonstrated via smog chamber experiments. Initially, particles in the chamber were pure rBC, produced from a methane burner and passed through a diffusion dryer and thermal denuder. An organic (non-rBC) coating was then grown onto the aerosol over several hours via photooxidation with p-xylene. The CPMA-SP2 coupled system sampled the aerosol over the reaction period as the coating grew. The CPMA was sequentially stepped over a mass range from 0.3 to 28 fg and the SP2 measured the mass of rBC in each individual CPMA-classified particle. The number and mass distributions were constructed using the inversion. As expected, the mass and number distributions of rBC and total mass were equivalent for uncoated particles. As the non-rBC coating thickness increased over time, a shift in the number distribution towards higher total mass was observed. At the end of the experiment, fresh rBC (i.e. uncoated, bare particles) was injected into the chamber, creating an external mixture of coated and uncoated particles. This external mixture was clearly resolved in the number distribution of rBC and total particle mass. It is expected that the CPMA-SP2 methodology and inversion technique would be useful for field measurements where the rBC mass fraction, and mixing state of rBC-containing particles, could be accurately measured continuously. This methodology is not limited to evaluating coating mass—unlike SP2 only methods, it gives an unambiguous measure of any non-rBC material mixed with the particle.

Nanomaterial release characteristics in a single-walled carbon nanotube manufacturing workplace

NASA Astrophysics Data System (ADS)

Ji, Jun Ho; Kim, Jong Bum; Lee, Gwangjae; Bae, Gwi-Nam

2015-02-01

As carbon nanotubes (CNTs) are widely used in various applications, exposure assessment also increases in importance with other various toxicity tests for CNTs. We conducted 24-h continuous nanoaerosol measurements to identify possible nanomaterial release in a single-walled carbon nanotube (SWCNT) manufacturing workplace. Four real-time aerosol instruments were used to determine the nanosized and microsized particle numbers, particle surface area, and carbonaceous species. Task-based exposure assessment was carried out for SWCNT synthesis using the arc plasma and thermal decomposition processes to remove amorphous carbon components as impurities. During the SWCNT synthesis, the black carbon (BC) concentration was 2-12 μg/m3. The maximum BC mass concentrations occurred when the synthesis chamber was opened for harvesting the SWCNTs. The number concentrations of particles with sizes 10-420 nm were 10,000-40,000 particles/cm3 during the tasks. The maximum number concentration existed when a vacuum pump was operated to remove exhaust air from the SWCNT synthesis chamber due to the penetration of highly concentrated oil mists through the window opened. We analyzed the particle mass size distribution and particle number size distribution for each peak episode. Using real-time aerosol detectors, we distinguished the SWCNT releases from background nanoaerosols such as oil mist and atmospheric photochemical smog particles. SWCNT aggregates with sizes of 1-10 μm were mainly released from the arc plasma synthesis. The harvesting process was the main release route of SWCNTs in the workplace.

Emissions of Black Carbon Particles in Anthropogenic and Biomass Plumes over California during CARB 2008

NASA Astrophysics Data System (ADS)

Sahu, L. K.; Kondo, Y.; Moteki, N.; Takegawa, N.; Zhao, Y.; Vay, S. A.; Diskin, G. S.; Wisthaler, A.; Huey, L. G.

2009-12-01

Measurements of black carbon (BC) and other chemical species were made from the NASA DC-8 aircraft during the CARB campaign conducted over California in June 2008. We operated an SP2 system that measured BC and scattering particles. The vertical profiles of BC and scattering particles show enhancements in the lower troposphere. We have used relations of CO-CH3CN-SO2 to identify the sources of major plumes. The plumes originating from anthropogenic activities, mainly due to the use of fossil fuels (FF), were observed near the surface. However, the influence of smoke plumes from wild fire or biomass-burning (BB) sources was observed up to 3 km. Overall, the 1-minute average BC mass concentrations were in the ranges of about 90-500 ng/m3 and 300-700 ng/m3 in FF and BB plumes, respectively. The shell/core diameter ratios were much lagerer in BB plumes than those in FF plumes. Namely, the median shell/core ratios were 1.2-1.4 for FF plumes, while they were 1.4-1.7 for BB plumes. In both FF and BB plumes, the mass-size distributions of BC were single mode lognormal. However, the mass median diameters FF plumes were considerably smaller. The BC-CO2 regression slopes were 19±9 ng m-3/ppmv and 270±90 ng m-3/ppmv for FF and BB plumes, respectively. On the other hand the regression slopes of BC-CO were about 3.3 ng m-3/ppbv in both the plumes. Conversely, the regression slopes of BC with other co-emitted combustions products can be used to estimate the contributions of emissions from different sources.

Ship-based Observations of Atmospheric Black Carbon Particles over the Arctic Ocean, Bering Sea, and North Western Pacific Ocean on 2016: Comparisons with Regional Chemical Transport Model simulations

NASA Astrophysics Data System (ADS)

Taketani, F.; Miyakawa, T.; Takigawa, M.; Yamaguchi, M.; Kanaya, Y.; Komazaki, Y.; Takashima, H.; Mordovskoi, P.; Tohjima, Y.

2017-12-01

Black carbon (BC), formed through the incomplete combustion of fossil fuels, biofuels, and biomass, is a major component of light-absorbing particulate matter in the atmosphere, causing positive radiative forcing. Also, BC deposition on the surface reduces the Earth's albedo and accelerates snow/ice melting by absorbing the sunlight. Therefore, the impact of BC on the Arctic climate needs to be assessed; however, observational information has been still insufficient. Over the Arctic Ocean, we have been conducting ship-based BC observations using a single particle soot photometer (SP2) on R/V Mirai every summer since 2014. To estimate the transport pathways of BC, we have also conducted model simulations during the period of cruise using a regional transport model (WRF-Chem 3.8.1). Here we focus on observations conducted on-board the R/V Mirai from 22 August to 5 October 2016 in a round trip to the Arctic Ocean through the Bering Strait from a port of Hachinohe (40.52N, 141.51E), Japan. We captured relatively high BC mass concentration events in this observation. The observed average BC mass concentration during 2016 was 0.8 ± 1.4 ng/m3 in >70N, similar to the levels ( 1.0ng/m3) recorded during our previous observations in the Arctic during 2014 and 2015. The variations in the observed concentrations in 2016 were qualitatively well reproduced by the regional chemical transport model. Quantitatively, however, the model tended to overestimate the BC levels, suggesting the possibilities that the emission rates were overestimated and/or the removal rates were underestimated. We will present further analysis on the size distribution, coating, and possible sources.

Simulation of black carbon aerosol distribution over India: A sensitivity study to different convective schemes

NASA Astrophysics Data System (ADS)

Ghosh, Sudipta; Dey, Sagnik; Das, Sushant; Venkataraman, Chandra; Patil, Nitin U.

2017-04-01

Black carbon (BC) aerosols absorb solar radiation, thereby causing a warming at the top-of-the-atmosphere (TOA) in contrast to most of the other aerosol species that scatter radiation causing a cooling at TOA. BC is considered to be an important contributor of global warming, second only to CO2 with a net radiative forcing of 1.1 w/m2. They have important regional climate effects, because of their spatially non-uniform heating and cooling. So it is very important to understand the spatio-temporal distribution of BC over India. In this study, we have used a regional climate model RegCM4.5 to simulate BC distribution over India with a focus on the BC estimation. The importance of incorporation of regional emission inventory has been shown and the sensitivity of BC distribution to various convective schemes in the model has been explored. The model output has been validated with in-situ observations. It is quite evident that regional inventory is capturing larger columnar burden of BC and OC than the global inventory. The difference in BC burden is clear at many places with the largest difference (in the order from 2 x 10-11 kg m-2 sec-1 in global inventory to 4 x 10-11 kg m-2 sec-1 in regional inventory) being observed over the Indo-Gangetic Basin. This difference is mainly attributed to the local sources like kerosene lamp burning, residential cooking on solid biomass fuel and agricultural residue burning etc., that are not considered in the global inventory. The difference is also noticeable for OC. Thus BC burden has increased with incorporation of regional emission inventory in the model, suggesting the importance of regional inventory in improved simulation and estimation of aerosols in this region. BC distribution is also sensitive to choice of scheme with Emanuel scheme capturing a comparatively smaller BC burden during the monsoon than Tiedtke scheme. Further long-term simulation with customized model is required to examine impact of BC. Keywords: Black carbon, RegCM4, regional emission inventory, convective schemes.

Measurements of Refractory Black Carbon (rBC) Aerosols in the McMurdo Dry Valleys, Antarctica

NASA Astrophysics Data System (ADS)

Khan, A. L.; McMeeking, G. R.; Lyons, W. B.; Schwarz, J. P.; Welch, K. A.; McKnight, D. M.

2015-12-01

Measurements of light absorbing particles in the boundary layer of the high southern latitudes are scarce. During the 2013-2014 austral summer field season refractory black carbon (rBC) aerosols were quantified by a single particle soot photometer (SP2) in the McMurdo Dry Valleys, Antarctica. The dark rBC particles absorb more radiation thereby increasing atmospheric heating, as well as reducing surface albedo and enhancing hydrologic melt when deposited on highly reflective surfaces such as snow and ice. Quantifying both local and long-range atmospheric transport of rBC to this region of a remote continent mostly covered by ice and snow would be useful in understanding meltwater generation as climate changes. Although the Dry Valleys are the largest ice-free region of Antarctica, they contain many alpine glaciers, some of which are fed from the East Antarctic Ice Sheet (EAIS). Continuous rBC measurements were collected at Lake Hoare Camp in the Taylor Valley for two months, along with shorter periods at more remote locations within the Dry Valleys. Conditions at the Lake Hoare Camp were dominated by up-valley winds from McMurdo Sound, however, winds also brought air down-valley from the EAIS polar plateau. Here we investigated periods dominated by both up and down-valley winds to explore differences in rBC concentrations, size distributions, and scattering properties. The average background rBC mass concentration was 1ng/m3, though concentrations as high as 50 ng/m3 were observed at times, likely due to local sources.

Characteristics of black carbon emissions from in-use light-duty passenger vehicles.

PubMed

Zheng, Xuan; Zhang, Shaojun; Wu, Ye; Zhang, K Max; Wu, Xian; Li, Zhenhua; Hao, Jiming

2017-12-01

Mitigating black carbon (BC) emissions from various combustion sources has been considered an urgent policy issue to address the challenges of climate change, air pollution and health risks. Vehicles contribute considerably to total anthropogenic BC emissions and urban BC concentrations. Compared with heavy-duty diesel vehicles, there is much larger uncertainty in BC emission factors for light-duty passenger vehicles (LDPVs), in particular for gasoline LDPVs, which warrants further studies. In this study, we employed the dynamometer and the Aethalometer (AE-51) to measure second-by-second BC emissions from eight LDPVs by engine technology and driving cycle. The average BC emission factors under transient cycles (e.g., ECE-15, New European Driving Cycle, NEDC, Worldwide Harmonized Light Vehicles Test Cycle, WLTC) are 3.6-91.5 mg/km, 7.6 mg/km and 0.13-0.58 mg/km, respectively, for diesel (N = 3), gasoline direct injection (GDI) (N = 1) and gasoline port-fuel injection (PFI) engine categories (N = 4). For gasoline PFI LDPVs, the instantaneous emission profiles show a strong association of peak BC emissions with cold-start and high-speed aggressive driving. Such impacts lead to considerable BC emission contributions in cold-start periods (e.g., the first 47 s-94 s) over the entire cycle (e.g., 18-76% of the NEDC and 13-36% of the WLTC) and increased BC emission factors by 80-440% under the WLTC compared to the NEDC. For diesel BC emissions, the size distribution exhibits a typical unimodal pattern with one single peak appearing approximately from 120 to 150 nm, which is largely consistent with previous studies. Nevertheless, the average mass ratios of BC to particle mass (PM) range from 0.38 to 0.54 for three diesel samples, representing substantial impacts from both driving and engine conditions. The significant discrepancy between gasoline BC emission factors obtained from tailpipe exhaust versus ambient conditions suggest that more comparative measurements and fine-grained simulations should be designed and implemented to address this discrepancy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular Subtypes of Indonesian Breast Carcinomas - Lack of Association with Patient Age and Tumor Size

PubMed Central

Rahmawati, Yeni; Setyawati, Yunita; Widodo, Irianiwati; Ghozali, Ahmad; Purnomosari, Dewajani

2018-01-01

Objective: Breast carcinoma (BC) is a heterogeneous disease that exhibits variation in biological behaviour, prognosis and response to therapy. Molecular classification is generally into Luminal A, Luminal B, HER2+ and triple negative/basal-like, depending on receptor characteristics. Clinical factors that determined the BC prognosis are age and tumor size. Since information on molecular subtypes of Indonesian BCs is limited, the present study was conducted, with attention to subtypes in relation to age and tumor size. Methods: A retrospective cross-sectional study of 247 paraffin-embedded samples of invasive BC from Dr. Sardjito General Hospital Yogyakarta in the year 2012- 2015 was performed. Immunohistochemical staining using anti- ER, PR, HER2, Ki-67 and CK 5/6 antibodies was applied to classify molecular subtypes. Associations with age and tumor size were analyzed using the Chi Square Test. Results: The Luminal A was the most common subtype of Indonesian BC (41.3%), followed by triple negative (25.5%), HER2 (19.4%) and luminal B (13.8%). Among the triple negative lesions, the basal-like subtype was more frequent than the non basal-like (58.8 % vs 41.2%). Luminal B accounted for the highest percentage of younger age cases (< 40 years old) while HER2+ was most common in older age (> 50 years old) patients. Triple negative/basal-like were commonly large in size. Age (p = 0.080) and tumor size (p = 0.462) were not significantly associated with molecular subtypes of BC. Conclusion: The most common molecular subtype of Indonesian BC is luminal A, followed by triple-negative, HER2+ and luminal B. The majority of triple-negative lesions are basal-like. There are no association between age and tumor size with molecular subtypes of Indonesian BCs. PMID:29373908

Molecular Subtypes of Indonesian Breast Carcinomas - Lack of Association with Patient Age and Tumor Size

PubMed

Rahmawati, Yeni; Setyawati, Yunita; Widodo, Irianiwati; Ghozali, Ahmad; Purnomosari, Dewajani

2018-01-27

Objective: Breast carcinoma (BC) is a heterogeneous disease that exhibits variation in biological behaviour, prognosis and response to therapy. Molecular classification is generally into Luminal A, Luminal B, HER2+ and triple negative/basal-like, depending on receptor characteristics. Clinical factors that determined the BC prognosis are age and tumor size. Since information on molecular subtypes of Indonesian BCs is limited, the present study was conducted, with attention to subtypes in relation to age and tumor size. Methods: A retrospective cross-sectional study of 247 paraffin-embedded samples of invasive BC from Dr. Sardjito General Hospital Yogyakarta in the year 2012- 2015 was performed. Immunohistochemical staining using anti- ER, PR, HER2, Ki-67 and CK 5/6 antibodies was applied to classify molecular subtypes. Associations with age and tumor size were analyzed using the Chi Square Test. Results: The Luminal A was the most common subtype of Indonesian BC (41.3%), followed by triple negative (25.5%), HER2 (19.4%) and luminal B (13.8%). Among the triple negative lesions, the basal-like subtype was more frequent than the non basal-like (58.8 % vs 41.2%). Luminal B accounted for the highest percentage of younger age cases (< 40 years old) while HER2+ was most common in older age (> 50 years old) patients. Triple negative/basal-like were commonly large in size. Age (p = 0.080) and tumor size (p = 0.462) were not significantly associated with molecular subtypes of BC. Conclusion: The most common molecular subtype of Indonesian BC is luminal A, followed by triple-negative, HER2+ and luminal B. The majority of triple-negative lesions are basal-like. There are no association between age and tumor size with molecular subtypes of Indonesian BCs. Creative Commons Attribution License

Changes in physical, chemical, and microbiological properties during the two-stage co-composting of green waste with spent mushroom compost and biochar.

PubMed

Zhang, Lu; Sun, Xiangyang

2014-11-01

This research determined whether the two-stage co-composting can be used to convert green waste (GW) into a useful compost. The GW was co-composted with spent mushroom compost (SMC) (at 0%, 35%, and 55%) and biochar (BC) (at 0%, 20%, and 30%). The combined addition of SMC and BC greatly increased the nutrient contents of the compost product and also improved the compost quality in terms of composting temperature, particle-size distribution, free air space, cation exchange capacity, nitrogen transformation, organic matter degradation, humification, element contents, abundance of aerobic heterotrophs, dehydrogenase activity, and toxicity to germinating seeds. The addition of 35% SMC and 20% BC to GW (dry weight % of initial GW) and the two-stage co-composting technology resulted in the production of the highest quality compost product in only 24 days rather than the 90-270 days required with traditional composting. Copyright © 2014 Elsevier Ltd. All rights reserved.

Production of nano bacterial cellulose from waste water of candied jujube-processing industry using Acetobacter xylinum.

PubMed

Li, Zheng; Wang, Lifen; Hua, Jiachuan; Jia, Shiru; Zhang, Jianfei; Liu, Hao

2015-04-20

The work is aimed to investigate the suitability of waste water of candied jujube-processing industry for the production of bacterial cellulose (BC) by Gluconacetobacter xylinum CGMCC No.2955 and to study the structure properties of bacterial cellulose membranes. After acid pretreatment, the glucose of hydrolysate was higher than that of waste water of candied jujube. The volumetric yield of bacterial cellulose in hydrolysate was 2.25 g/L, which was 1.5-folds of that in waste water of candied jujube. The structures indicated that the fiber size distribution was 3-14 nm in those media with an average diameter being around 5.9 nm. The crystallinity index of BC from pretreatment medium was lower than that of without pretreatment medium and BCs from various media had similar chemical binding. Ammonium citrate was a key factor for improving production yield and the crystallinity index of BC. Copyright © 2014 Elsevier Ltd. All rights reserved.

Impact of Grain Shape and Multiple Black Carbon Internal Mixing on Snow Albedo: Parameterization and Radiative Effect Analysis

NASA Astrophysics Data System (ADS)

He, Cenlin; Liou, Kuo-Nan; Takano, Yoshi; Yang, Ping; Qi, Ling; Chen, Fei

2018-01-01

We quantify the effects of grain shape and multiple black carbon (BC)-snow internal mixing on snow albedo by explicitly resolving shape and mixing structures. Nonspherical snow grains tend to have higher albedos than spheres with the same effective sizes, while the albedo difference due to shape effects increases with grain size, with up to 0.013 and 0.055 for effective radii of 1,000 μm at visible and near-infrared bands, respectively. BC-snow internal mixing reduces snow albedo at wavelengths < 1.5 μm, with negligible effects at longer wavelengths. Nonspherical snow grains show less BC-induced albedo reductions than spheres with the same effective sizes by up to 0.06 at ultraviolet and visible bands. Compared with external mixing, internal mixing enhances snow albedo reduction by a factor of 1.2-2.0 at visible wavelengths depending on BC concentration and snow shape. The opposite effects on albedo reductions due to snow grain nonsphericity and BC-snow internal mixing point toward a careful investigation of these two factors simultaneously in climate modeling. We further develop parameterizations for snow albedo and its reduction by accounting for grain shape and BC-snow internal/external mixing. Combining the parameterizations with BC-in-snow measurements in China, North America, and the Arctic, we estimate that nonspherical snow grains reduce BC-induced albedo radiative effects by up to 50% compared with spherical grains. Moreover, BC-snow internal mixing enhances the albedo effects by up to 30% (130%) for spherical (nonspherical) grains relative to external mixing. The overall uncertainty induced by snow shape and BC-snow mixing state is about 21-32%.

Inference of Spatiotemporal Distribution of Black Carbon Aerosols over Northern Pacific from Satellite Observations (2005-2012)

NASA Astrophysics Data System (ADS)

Liu, J.; Li, Z.; Mauzerall, D. L.; Fan, S.; Horowitz, L. W.; He, C.; Yi, K.; Tao, S.

2015-12-01

Knowledge on the spatiotemporal distribution of black carbon aerosol over the Northern Pacific is limited by a deficiency of observations. The HIAPER Pole-to-Pole Observation (HIPPO) program from 2009 to 2011 is the most comprehensive data source available and it reveals a 2 to 10 times overestimates of BC by current global models. Incorporation and assimilation of more data sources is needed to increase our understanding of the spatiotemporal distribution of black carbon aerosol and its corresponding climate effects. Based on measurements from aircraft campaigns and satellites, a robust association is observed between BC concentrations and satellite retrieved CO, tropospheric NO2, and aerosol optical depth (AOD) (R2 > 0.7). Such robust relationships indicate that BC aerosols share a similar emission sources, evolution processes and transport characteristics with other pollutants measured by satellite observations. It also establishes a basis to derive a satellite-based proxy (BC*) over remote oceans. The inferred satellite-based BC* shows that Asian export events in spring bring much more BC aerosols to the mid-Pacific than occurs in other seasons. In addition, inter-annual variability of BC* is seen over the Northern Pacific, with abundances correlated to the springtime Pacific/North American (PNA) index. The inferred BC* dataset also indicates a widespread overestimation of BC loadings by models over most remote oceans beyond the Pacific. Our method presents a novel approach to infer BC concentrations by combining satellite and aircraft observations.

Association of marine viral and bacterial communities with reference black carbon particles under experimental conditions: an analysis with scanning electron, epifluorescence and confocal laser scanning microscopy.

PubMed

Cattaneo, Raffaela; Rouviere, Christian; Rassoulzadegan, Fereidoun; Weinbauer, Markus G

2010-11-01

Black carbon (BC), the product of incomplete combustion of fossil fuels and biomass, constitutes a significant fraction of the marine organic carbon pool. However, little is known about the possible interactions of BC and marine microorganisms. Here, we report the results of experiments using a standard reference BC material in high concentrations to investigate basic principles of the dynamics of natural bacterial and viral communities with BC particles. We assessed the attachment of viral and bacterial communities using scanning electron, epifluorescence and confocal laser scanning microscopy and shifts in bacterial community composition using 16S rRNA gene denaturing gradient gel electrophoresis (DGGE). In 24-h time-course experiments, BC particles showed a strong potential for absorbing viruses and bacteria. Total viral abundance was reduced, whereas total bacterial abundance was stimulated in the BC treatments. Viral and bacterial abundance on BC particles increased with particle size, whereas the abundances of BC-associated viruses and bacteria per square micrometer surface area decreased significantly with BC particle size. DGGE results suggested that BC has the potential to change bacterial community structure and favour phylotypes related to Glaciecola sp. Our study indicates that BC could influence processes mediated by bacteria and viruses in marine ecosystems. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

From the Cover: Disease-Induced Disparities in Formation of the Nanoparticle-Biocorona and the Toxicological Consequences

PubMed Central

Shannahan, Jonathan H.; Fritz, Kristofer S.; Raghavendra, Achyut J.; Podila, Ramakrishna; Persaud, Indushekar; Brown, Jared M.

2016-01-01

Nanoparticle (NP) association with macromolecules in a physiological environment forms a biocorona (BC), which alters NP distribution, activity, and toxicity. While BC formation is dependent on NP physicochemical properties, little information exists on the influence of the physiological environment. Obese individuals and those with cardiovascular disease exist with altered serum chemistry, which is expected to influence BC formation and NP toxicity. We hypothesize that a BC formed on NPs following incubation in hyperlipidemic serum will result in altered NP–BC protein content, cellular association, and toxicity compared to normal serum conditions. We utilized Fe3O4 NPs, which are being developed as MRI contrast and tumor targeting agents to test our hypothesis. We used rat aortic endothelial cells (RAECs) within a dynamic flow in vitro exposure system to more accurately depict the in vivo environment. A BC was formed on 20nm PVP-suspended Fe3O4 NPs following incubation in water, 10% normal or hyperlipidemic rat serum. Addition of BCs resulted in increased hydrodynamic size and decreased surface charge. More cholesterol associated with Fe3O4 NPs after incubation in hyperlipidemic as compared with normal serum. Using quantitative proteomics, we identified unique differences in BC protein components between the 2 serum types. Under flow conditions, formation of a BC from both serum types reduced RAECs association of Fe3O4 NPs. Addition of BCs was found to exacerbate RAECs inflammatory gene responses to Fe3O4 NPs (Fe3O4-hyperlipidemic > Fe3O4-normal > Fe3O4) including increased expression of IL-6, TNF-α, Cxcl-2, VCAM-1, and ICAM-1. Overall, these findings demonstrate that disease-induced variations in physiological environments have a significant impact NP-BC formation, cellular association, and cell response. PMID:27255384

Cloning, monoclonal antibody production, and bodily distribution pattern of a bovine lipocalin.

PubMed

Japaridze, Tamar; Senda, Akitsugu; Nozaki, Hirofumi; Yanagida, Mayumi; Suzuki, Takumi; Ganzorig, Khuukhenbaatar; Kushi, Yasunori; Kida, Katsuya; Urashima, Tadasu; Bruckmaier, Rupert M; Fukuda, Kenji

2012-01-01

A bovine lipocalin, previously identified as a putative odorant-binding protein in bovine colostrum (bcOBP), was cloned and expressed, and its monoclonal antibody was established. bcOBP was constantly secreted into milk on day of parturition until at least 10 d postpartum at a concentration of 181±39 µg/L. Besides milk, bcOBP occurred in the nasal mucus, saliva, amniotic fluid, vaginal discharge, and blood plasma. Despite its low concentration, the distribution pattern and the finding that bcOBP harbored a characteristic sequence motif, CxxxC, which is conserved among insect and mammal pheromone binding proteins, suggest that bcOBP functions as a pheromone carrier. The presence of bcOBP in the plasma at varied concentrations depending on the lactation period does not exclude the possibility that bcOBP is secreted into milk from the blood. Cross-reactivity of the monoclonal antibody indicated presence of proteins homologous to bcOBP in the colostrum of farm animals of Cetartiodactyla.

Black carbon radiative forcing derived from AERONET measurements and models over an urban location in the southeastern Iberian Peninsula

NASA Astrophysics Data System (ADS)

Valenzuela, A.; Arola, A.; Antón, M.; Quirantes, A.; Alados-Arboledas, L.

2017-07-01

This paper provides an account of observed variations in Black carbon (BC) aerosol concentrations and their induced radiative forcing for the first time over Granada a measurement site in Southeastern Iberian Peninsula. Column-integrated BC concentrations were retrieved for the period 2005-2012. Monthly averages of BC concentrations (± one standard deviation) ranged from higher values in January and December with 4.0 ± 2.5 and 4 ± 3 mg/m2, respectively, to lower values in July and August with 1.6 ± 1.2 and 2.0 ± 0.5 mg/m2, respectively. This reduction is not only observed in the average values, but also in the median, third and first quartiles. The average BC concentration in winter (3.8 ± 0.6 mg/m2) was substantially higher than in summer (1.9 ± 0.3 mg/m2), being the eight-year average of 2.9 ± 0.9 mg/m2. The reduction in the use of fossil fuels during the economic crisis contributed significantly to reduced atmospheric loadings of BC. According to our analysis this situation persisted until 2010. BC concentration values were analyzed in terms of air mass influence using cluster analysis. BC concentrations for cluster 1 (local and regional areas) showed high correlations with air masses frequency in winter and autumn. In these seasons BC sources were related to the intense road traffic and increased BC emissions from domestic heating. High BC concentrations were found in autumn just when air mass frequencies for cluster 3 (Mediterranean region) were more elevated, suggesting that air masses coming from that area transport biomass burning particles towards Granada. BC aerosol optical properties were retrieved from BC fraction using aerosol AERONET size volume distribution and Mie theory. A radiative transfer model (SBDART) was used to estimate the aerosol radiative forcing separately for composite aerosol (total aerosols) and exclusively for BC aerosols. The mean radiative forcing for composite aerosol was + 23 ± 6 W/m2 (heating rate of + 0.21 ± 0.06 K/day) and + 15 ± 6 W/m2 for BC aerosol (heating rate of + 0.15 ± 0.06 K/day). These values of radiative forcing and heating rate for BC aerosol represent about 70% of their values for composite aerosol, which highlights the crucial role that BC aerosols play in modifying the radiation budget and climate.

Preserved Network Metrics across Translated Texts

NASA Astrophysics Data System (ADS)

Cabatbat, Josephine Jill T.; Monsanto, Jica P.; Tapang, Giovanni A.

2014-09-01

Co-occurrence language networks based on Bible translations and the Universal Declaration of Human Rights (UDHR) translations in different languages were constructed and compared with random text networks. Among the considered network metrics, the network size, N, the normalized betweenness centrality (BC), and the average k-nearest neighbors, knn, were found to be the most preserved across translations. Moreover, similar frequency distributions of co-occurring network motifs were observed for translated texts networks.

Enhanced light absorption due to the mixing state of black carbon in fresh biomass burning emissions

NASA Astrophysics Data System (ADS)

Wang, Qiyuan; Cao, Junji; Han, Yongming; Tian, Jie; Zhang, Yue; Pongpiachan, Siwatt; Zhang, Yonggang; Li, Li; Niu, Xinyi; Shen, Zhenxing; Zhao, Zhuzi; Tipmanee, Danai; Bunsomboonsakul, Suratta; Chen, Yang; Sun, Jian

2018-05-01

A lack of information on the radiative effects of refractory black carbon (rBC) emitted from biomass burning is a significant gap in our understanding of climate change. A custom-made combustion chamber was used to simulate the open burning of crop residues and investigate the impacts of rBC size and mixing state on the particles' optical properties. Average rBC mass median diameters ranged from 141 to 162 nm for the rBC produced from different types of crop residues. The number fraction of thickly-coated rBC varied from 53 to 64%, suggesting that a majority of the freshly emitted rBC were internally mixed. By comparing the result of observed mass absorption cross-section to that calculated with Mie theory, large light absorption enhancement factors (1.7-1.9) were found for coated particles relative to uncoated cores. These effects were strongly positively correlated with the percentage of coated particles but independent of rBC core size. We suggest that rBC from open biomass burning may have strong impact on air pollution and radiative forcing immediately after their production.

Size resolved Internally Mixed Black Carbon and the Absorption Enhancement in the Indo-Gangetic Plain due to internally mixed BC

NASA Astrophysics Data System (ADS)

Tripathi, S. N.; Thamban, N.

2017-12-01

Indo-Gangetic Plain (IGP) is one of the most populated and polluted regions in northern India. Even though IGP is a well-known "absorbing aerosol hotspot", information of BC mixing state in IGP is mostly unknown. Our calculation on size resolved mixing state in IGP shown that the mixing state of BC changes with the core diameter of BC. The majority of BC particle were thickly coated ( 80%) at lower diameter (75-125 nm) and the externally mixed BC fraction was gradually increased at higher core diameter of BC (125-250 nm). The mean fraction of "thickly coated BC" particles (fTCBC) was found to be 61.6% for a BC core diameter of 70 to 450 nm, indicating that a large fraction of BC particles was internally mixed in IGP. The fTCBC increased after sunrise with a peak at about noontime, indicating that the formation of secondary organic aerosol under active photochemistry can enhance organic coating on a core of black carbon. A positive correlation between the fTCBC and the mass absorption cross-section at 781nm (MAC781) was also observed (r=0.58). Our results identify that the observed fTCBC in IGP could amplify the MAC781 approximately by a factor of 1.8, which may catalyze the positive radiative forcing.

FIREX-Related Biomass Burning Research Using ARM Single-Particle Soot Photometer Field Campaign Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onasch, Timothy B; Sedlacek, Arthur J

The scientific focus of this study was to investigate and quantify the mass loadings, chemical compositions, and optical properties of biomass burning particulate emissions generated in the laboratory from Western U.S. fuels using a similar instrument suite to the one deployed on the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility Gulfstream-1 (G-1) aircraft during the 2013 Biomass Burning Observation Project (BBOP) field study (Kleinman and Sedlacek, 2013). We deployed the single-particle soot photometer (SP2) to make measurements of biomass burning refractory black carbon (rBC) mass loadings and size distributions to correlate with non-refractory particulate mattermore » (NR-PM; i.e., HR-AMS) and rBC (SP-AMS) measurements as a function of photo-oxidation processes in an environmental chamber. With these measurements, we will address the following scientific questions: 1. What are the emission indices (g/kg fuel) of rBC from various wildland fuels from the Pacific Northwest (i.e., relevant to BBOP analysis) as a function of combustion conditions and simulated atmospheric processing in an environmental chamber? 2. What are the optical properties (e.g., mass-specific absorption cross-section [MAC], single-scattering albedo [SSA], and absorption Angstrom exponent [AAE)] of rBC emitted from various wildland fuels and how are they impacted by atmospheric processing? 3. How does the mixing state of rBC in biomass-burning plumes relate to the optical properties? 4. How does the emitted rBC affect radiative forcing?« less

Downwind evolution of the volatility and mixing state of near-road aerosols near a US interstate highway

NASA Astrophysics Data System (ADS)

Saha, Provat K.; Khlystov, Andrey; Grieshop, Andrew P.

2018-02-01

We present spatial measurements of particle volatility and mixing state at a site near a North Carolina interstate highway (I-40) applying several heating (thermodenuder; TD) experimental approaches. Measurements were conducted in summer 2015 and winter 2016 in a roadside trailer (10 m from road edge) and during downwind transects at different distances from the highway under favorable wind conditions using a mobile platform. Results show that the relative abundance of semi-volatile species (SVOCs) in ultrafine particles decreases with downwind distance, which is consistent with the dilution and mixing of traffic-sourced particles with background air and evaporation of semi-volatile species during downwind transport. An evaporation kinetics model was used to derive particle volatility distributions by fitting TD data. While the TD-derived distribution apportions about 20-30 % of particle mass as semi-volatile (SVOCs; effective saturation concentration, C∗ ≥ 1µm-3) at 10 m from the road edge, approximately 10 % of particle mass is attributed to SVOCs at 220 m, showing that the particle-phase semi-volatile fraction decreases with downwind distance. The relative abundance of semi-volatile material in the particle phase increased during winter. Downwind spatial gradients of the less volatile particle fraction (that remaining after heating at 180 °C) were strongly correlated with black carbon (BC). BC size distribution and mixing state measured using a single-particle soot photometer (SP2) at the roadside trailer showed that a large fraction (70-80 %) of BC particles were externally mixed. Heating experiments with a volatility tandem differential mobility analyzer (V-TDMA) also showed that the nonvolatile fraction in roadside aerosols is mostly externally mixed. V-TDMA measurements at different distances downwind from the highway indicate that the mixing state of roadside aerosols does not change significantly (e.g., BC mostly remains externally mixed) within a few hundred meters from the highway. Our analysis indicates that a superposition of volatility distributions measured in laboratory vehicle tests and of background aerosol can be used to represent the observed partitioning of near-road particles. The results from this study show that exposures and impacts of BC and semi-volatile organics-containing particles in a roadside microenvironment may differ across seasons and under changing ambient conditions.

Preliminary Results from VOC measurements in the Lower Fraser Valley in July/Aug 2012

NASA Astrophysics Data System (ADS)

Schiller, C. L.; Jones, K.; Vingarzan, R.; Leaitch, R.; Macdonald, A.; Osthoff, H. D.; Reid, K.

2012-12-01

In July/August 2012, a pilot study looking at the effect of ClNO2 production on the ozone concentrations in the lower Fraser valley near Abbotsford, BC was conducted. The lower Fraser valley in British Columbia Canada has some of the highest ozone concentrations and visibility issues in Canada. Abbotsford is located approximately 80 kms east of Vancouver, BC and approximately 30 kms from the ocean. The site was located in a largely agricultural area with fruit farms (raspberries and blueberries) and poultry barns predominating. During the study biogenic and anthropogenic VOCs were measured in situ using a GCMS/FID with hourly samples. Particle composition was measured using an ACSM and size distribution using an SMPS. Preliminary results from the study will be discussed.

[Analysis on HIV-1 subtypes and transmission clusters in newly reported HIV/AIDS cases in Yiwu, Zhejiang Province, 2016].

PubMed

Zhang, J F; Yao, J M; Fan, Q; Chen, W J; Pan, X H; Ding, X B; Yang, J Z; Fu, T

2017-12-10

Objective: To understand the characteristics of distribution on HIV-1 subtypes and the transmission clusters in Yiwu in Zhejiang province. Methods: A cross-sectional study of molecular epidemiology was carried out on newly reported HIV/AIDS cases in Yiwu. RNA was extracted from 168 plasma samples, followed by RT-PCR and nest-PCR for pol gene amplification, sequencing, phylogenetic tree construction used for analyzing the subtypes and transmission clusters. Mutations on drug resistance was analyzed by CPR 6.0 online tool. Results: Subjects were mainly males (86.3%, 145/168), with average age as (39.1±13.4) years old and most of them were migrants (66.7%, 112/168). The major routes of transmission included homosexual (51.2%, 86/168) and heterosexual (48.8%, 82/168) contacts. The rate of success for sequence acquisition was 89.9% (151/168). The dominant subtypes showed as CRF01_AE (74, 49.0%) and CRF07_BC (64, 42.4%), followed by CRF08_BC (5, 3.3%), CRF55_01B (3, 2.0%), each case of subtype B, CRF45_cpx, CRF59_01B, CRF85_BC and URF (B/C). CRF45_cpx and CRF85_BC were discovered the first time in Zhejiang province. Twenty-six transmission clusters involving 65 cases were found, with the total clustered rate as 43.0% (65/151), in which the CRF01_AE clustered rate appeared as 54.1% (40/74), higher than that of CRF07_BC (21/64, 32.8%). The average size of cluster was 2.5 cases/cluster, with average size of cluster in CRF01_AE patients infected through heterosexual transmission as the largest (3.5 cases/cluster). The prevalence of transmitted drug resistance was 4.6% (7/151). Seven cases with surveillance drug resistant mutations (SDRM) were found, including 5 cases of M46L (3.3%), and one case of F77L or Y181C. Conclusion: HIV genetic diversity and a variety of transmission clusters had been noticed in this study area (Yiwu). Programs on monitoring the subtypes and transmission clusters should be continued and strengthened.

Radiative effects of light-absorbing particles deposited in snow over Himalayas using WRF-Chem simulations

NASA Astrophysics Data System (ADS)

Sarangi, C.; Qian, Y.; Painter, T. H.; Liu, Y.; Lin, G.; Wang, H.

2017-12-01

Radiative forcing induced by light-absorbing particles (LAP) deposited on snow is an important surface forcing. It has been debated that an aerosol-induced increase in atmospheric and surface warming over Tibetan Plateau (TP) prior to the South Asian summer monsoon can have a significant effect on the regional thermodynamics and South Asian monsoon circulation. However, knowledge about the radiative effects due to deposition of LAP in snow over TP is limited. In this study we have used a high-resolution WRF-Chem (coupled with online chemistry and snow-LAP-radiation model) simulations during 2013-2014 to estimate the spatio-temporal variation in LAP deposition on snow, specifically black carbon (BC) and dust particles, in Himalayas. Simulated distributions in meteorology, aerosol concentrations, snow albedo, snow grain size and snow depth are evaluated against satellite and in-situ measurements. The spatio-temporal change in snow albedo and snow grain size with variation in LAP deposition is investigated and the resulting shortwave LAP radiative forcing at surface is calculated. The LAP-radiative forcing due to aerosol deposition, both BC and dust, is higher in magnitude over Himalayan slopes (terrain height below 4 km) compared to that over TP (terrain height above 4 km). We found that the shortwave aerosol radiative forcing efficiency at surface due to increase in deposited mass of BC particles in snow layer ( 25 (W/m2)/ (mg/m2)) is manifold higher than the efficiency of dust particles ( 0.1 (W/m2)/ (mg/m2)) over TP. However, the radiative forcing of dust deposited in snow is similar in magnitude (maximum 20-30 W/m2) to that of BC deposited in snow over TP. This is mainly because the amount of dust deposited in snow over TP can be about 100 times greater than the amount of BC deposited in snow during polluted conditions. The impact of LAP on surface energy balance, snow melting and atmospheric thermodynamics is also examined.

The Distribution of Snow Black Carbon observed in the Arctic and Compared to the GISS-PUCCINI Model

NASA Technical Reports Server (NTRS)

Dou, T.; Xiao, C.; Shindell, D. T.; Liu, J.; Eleftheriadis, K.; Ming, J.; Qin, D.

2012-01-01

In this study, we evaluate the ability of the latest NASA GISS composition-climate model, GISS-E2- PUCCINI, to simulate the spatial distribution of snow BC (sBC) in the Arctic relative to present-day observations. Radiative forcing due to BC deposition onto Arctic snow and sea ice is also estimated. Two sets of model simulations are analyzed, where meteorology is linearly relaxed towards National Centers for Environmental Prediction (NCEP) and towards NASA Modern Era Reanalysis for Research and Applications (MERRA) reanalyses. Results indicate that the modeled concentrations of sBC are comparable with presentday observations in and around the Arctic Ocean, except for apparent underestimation at a few sites in the Russian Arctic. That said, the model has some biases in its simulated spatial distribution of BC deposition to the Arctic. The simulations from the two model runs are roughly equal, indicating that discrepancies between model and observations come from other sources. Underestimation of biomass burning emissions in Northern Eurasia may be the main cause of the low biases in the Russian Arctic. Comparisons of modeled aerosol BC (aBC) with long-term surface observations at Barrow, Alert, Zeppelin and Nord stations show significant underestimation in winter and spring concentrations in the Arctic (most significant in Alaska), although the simulated seasonality of aBC has been greatly improved relative to earlier model versions. This is consistent with simulated biases in vertical profiles of aBC, with underestimation in the lower and middle troposphere but overestimation in the upper troposphere and lower stratosphere, suggesting that the wet removal processes in the current model may be too weak or that vertical transport is too rapid, although the simulated BC lifetime seems reasonable. The combination of observations and modeling provides a comprehensive distribution of sBC over the Arctic. On the basis of this distribution, we estimate the decrease in snow and sea ice albedo and the resulting radiative forcing. We suggest that the albedo reduction due to BC deposition presents significant space-time variations, with highest mean reductions of 1.25% in the Russian Arctic, which are much larger than those in other Arctic regions (0.39% to 0.64 %). The averaged value over the Arctic north of 66degN is 0.4-0.6% during spring, leading to regional surface radiative forcings of 0.7, 1.1 and 1.0Wm(exp-2) in spring 2007, 2008 and 2009, respectively.

Black carbon emissions from trucks and trains in the Midwestern and Northeastern United States from 1977 to 2007

NASA Astrophysics Data System (ADS)

Brown-Steiner, Benjamin; Hess, Peter; Chen, Jialie; Donaghy, Kieran

2016-03-01

We have developed a framework to estimate BC emissions from heavy-duty diesel trucks and trains engaged in transporting freight in the Midwestern and Northeastern United States (MNUS) from 1977 to 2007. We first expand on a previous development of a regional econometric input-output model (REIM) that has been used to estimate commodity flows between 13 states in the MNUS (plus the rest of the US) and 13 industrial sectors. These commodity flow data are then distributed over the MNUS using a stylized link-and-node network, which creates great circle transportation links between nodes in each state at the county with the largest population. Freight flows are converted to BC transportation emissions and the resulting BC emissions are compared to the MACCity BC emissions inventory. We find that from 1977 to 2007 potential emission growth from the continued increase in freight tonnage in the MWUS is counteracted by decreases in the BC emission factor of heavy-duty diesel trucks, which results in an overall decrease of BC emissions by 2007. One sector (fabricated metal product manufacturing) has dominated the BC transportation emissions throughout 1977 to 2007 with transportation emissions remaining relatively unchanged from 1977 to 1997 and then decreasing out to 2007. The BC transportation emissions are concentrated in and around the urban centers, which serve as transportation and production nodes for industrial manufacturing. Our BC emissions are distributed along stylized transportation corridors that are not well represented in emissions inventories that largely distribute emissions via a population proxy. The framework established in this study can be used to estimate future BC transportation emissions under a set of stylized economic, technological, and regulatory scenarios.

Fractal scaling laws of black carbon aerosol and their influence on spectral radiative properties

NASA Astrophysics Data System (ADS)

Tiwari, S.; Chakrabarty, R. K.; Heinson, W.

2016-12-01

Current estimates of the direct radiative forcing for Black Carbon (BC) aerosol span over a poorly constrained range between 0.2 and 1 W.m-2. To improve this large uncertainty, tighter constraints need to be placed on BC's key wavelength-dependent optical properties, namely, the absorption (MAC) and scattering (MSC) cross sections per unit mass and hemispherical upscatter fraction (β; a dimensionless scattering directionality parameter). These parameters are very sensitive to changes in particle morphology and complex refractive index nindex. Their interplay determines the magnitude of net positive or negative radiative forcing efficiencies. The current approach among climate modelers for estimating MAC and MSC values of BC is from their optical cross-sections calculated assuming spherical particle morphology with homogeneous, constant-valued refractive index in the visible solar spectrum. The β values are typically assumed to be a constant across this spectrum. This approach, while being computationally inexpensive and convenient, ignores the inherent fractal morphology of BC and its scaling behaviors, and resulting optical properties. In this talk, I will present recent results from my laboratory on determination of the fractal scaling laws of BC aggregate packing density and its complex refractive index for size spanning across three orders of magnitude, and their effects on spectral (Visible-infrared wavelength) scaling of MAC, MSC, and β values. Our experiments synergistically combined novel BC generation techniques, aggregation models, contact-free multi-wavelength optical measurements, and electron microscopy analysis. The scale dependence of nindex on aggregate size followed power-law exponents of -1.4 and -0.5 for sub- and super-micron size aggregates, respectively. The spherical Rayleigh-optics approximation limits, used by climate models for spectral extrapolation of BC optical cross-sections and deconvolution of multi-species mixing ratios, are redefined using the concept of phase shift parameter. I will highlight the importance of size-dependent β values and its role in offsetting the strong light absorbing nature of BC. Finally, the errors introduced in forcing efficiency calculations of BC by assuming spherical homogeneous morphology will be evaluated.

Comprehensive Characterization Of Ultrafine Particulate Emission From 2007 Diesel Engines: PM Size Distribution, Loading And Indidividual Particle Size And Composition.

NASA Astrophysics Data System (ADS)

Zelenyuk, A.; Cuadra-Rodriguez, L. A.; Imre, D.; Shimpi, S.; Warey, A.

2006-12-01

The strong absorption of solar radiation by black carbon (BC) impacts the atmospheric radiative balance in a complex and significant manner. One of the most important sources of BC is vehicular emissions, of which diesel represents a significant fraction. To address this issue the EPA has issues new stringent regulations that will be in effect in 2007, limiting the amount of particulate mass that can be emitted by diesel engines. The new engines are equipped with aftertreatments that reduce PM emissions to the point, where filter measurements are subject to significant artifacts and characterization by other techniques presents new challenges. We will present the results of the multidisciplinary study conducted at the Cummins Technical Center in which a suite of instruments was deployed to yield comprehensive, temporally resolved information on the diesel exhaust particle loadings and properties in real-time: Particle size distributions were measured by Engine Exhaust Particle Sizer (EEPS) and Scanning Mobility Particle Sizer (SMPS). Total particle diameter concentration was obtained using Electrical Aerosol Detector (EAD). Laser Induced Incandescence and photoacoustic techniques were used to monitor the PM soot content. Single Particle Laser Ablation Time-of- flight Mass Spectrometer (SPLAT) provided the aerodynamic diameter and chemical composition of individual diesel exhaust particles. Measurements were conducted on a number of heavy duty diesel engines operated under variety of operating conditions, including FTP transient cycles, ramped-modal cycles and steady states runs. We have also characterized PM emissions during diesel particulate filter regeneration cycles. We will present a comparison of PM characteristics observed during identical cycles, but with and without the use of aftertreatment. A total of approximately 100,000 individual particles were sized and their composition characterized by SPLAT. The aerodynamic size distributions of the characterized particles were between 50 and 300 nm, depending on engine operating conditions and particle composition. We will show that while the drastically reduced diesel PM emissions often render the PM filter measurements inadequate due to organic vapor artifacts SPLAT demonstrated its capability to provide real-time information on size and composition of individual diesel exhaust particles as function of engine operating conditions with better than 1 minute resolution.

Mutations in BRCA1, BRCA2 and other breast and ovarian cancer susceptibility genes in Central and South American populations.

PubMed

Jara, Lilian; Morales, Sebastian; de Mayo, Tomas; Gonzalez-Hormazabal, Patricio; Carrasco, Valentina; Godoy, Raul

2017-10-06

Breast cancer (BC) is the most common malignancy among women worldwide. A major advance in the understanding of the genetic etiology of BC was the discovery of BRCA1 and BRCA2 (BRCA1/2) genes, which are considered high-penetrance BC genes. In non-carriers of BRCA1/2 mutations, disease susceptibility may be explained of a small number of mutations in BRCA1/2 and a much higher proportion of mutations in ethnicity-specific moderate- and/or low-penetrance genes. In Central and South American populations, studied have focused on analyzing the distribution and prevalence of BRCA1/2 mutations and other susceptibility genes that are scarce in Latin America as compared to North America, Europe, Australia, and Israel. Thus, the aim of this review is to present the current state of knowledge regarding pathogenic BRCA variants and other BC susceptibility genes. We conducted a comprehensive review of 47 studies from 12 countries in Central and South America published between 2002 and 2017 reporting the prevalence and/or spectrum of mutations and pathogenic variants in BRCA1/2 and other BC susceptibility genes. The studies on BRCA1/2 mutations screened a total of 5956 individuals, and studies on susceptibility genes analyzed a combined sample size of 11,578 individuals. To date, a total of 190 different BRCA1/2 pathogenic mutations in Central and South American populations have been reported in the literature. Pathogenic mutations or variants that increase BC risk have been reported in the following genes or genomic regions: ATM, BARD1, CHECK2, FGFR2, GSTM1, MAP3K1, MTHFR, PALB2, RAD51, TOX3, TP53, XRCC1, and 2q35.

46 CFR 199.175 - Survival craft and rescue boat equipment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... breakage-resistant material. (9) Fire extinguisher. The fire extinguisher must be approved under approval series 162.028. The fire extinguisher must be type B-C, size II, or larger. Two type B-C, size I fire... portions of the hull. (4) Bucket. The bucket must be made of corrosion-resistant material and should either...

Reduction in advanced breast cancer after introduction of a mammography screening program in Tyrol/Austria.

PubMed

Oberaigner, W; Geiger-Gritsch, Sabine; Edlinger, M; Daniaux, M; Knapp, R; Hubalek, M; Siebert, U; Marth, C; Buchberger, W

2017-06-01

We analysed all female breast cancer (BC) cases in Tyrol/Austria regarding the shift in cancer characteristics, especially the shift in advanced BC, for the group exposed to screening as compared to the group unexposed to screening. The analysis was based on all BC cases diagnosed in women aged 40-69 years, resident in Tyrol, and diagnosed between 2009 and 2013. The data were linked to the Tyrolean mammography screening programme database to classify BC cases as "exposed to screening" or "unexposed to screening". Age-adjusted relative risks (RR) were estimated by relating the exposed to the unexposed group. In a total of about 145,000 women aged 40-69 years living in Tyrol during the study period, 1475 invasive BC cases were registered. We estimated an age-adjusted relative risk (RR) for tumour size ≥ 21 mm of 0.72 (95% confidence interval (CI) 0.60 to 0.86), for metastatic BC of 0.27 (95% CI 0.17 to 0.46) and for advanced BC of 0.83 (95% CI 0.71 to 0.96), each comparing those exposed to those unexposed to screening, respectively. In our population-based registry analysis we observed that participation in the mammography screening programme in Tyrol is associated with a 28% decrease in risk for BC cases with tumour size ≥ 21 mm and a 17% decrease in risk for advanced BC. We therefore expect the Tyrolean mammography programme to show a reduction in BC mortality. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterisation of Black Carbon (BC) mixing state and flux in Beijing using single particle measurements.

NASA Astrophysics Data System (ADS)

Joshi, Rutambhara; Liu, Dantong; Allan, James; Coe, Hugh; Flynn, Michael; Broda, Kurtis; Olfert, Jason; Irwin, Martin; Sun, Yele; Fu, Pingqing; Wang, Junfeng; Ge, Xinlei; Langford, Ben; Nemitz, Eiko; Mullinger, Neil

2017-04-01

BC is generated by the incomplete combustion of carbonaceous fuels and it is an important component of fine PM2.5. In the atmosphere BC particles have a complex structure and its mixing state has crucial impact on optical properties. Quantifying the sources and emissions of black carbon in urban environments is important and presently uncertain, particularly in megacities undergoing rapid growth and change in emissions. During the winter of 2016 (10th Nov-10th Dec) the BC was characterised as part of a large joint UK-China field experiment in Beijing. This paper focuses on understanding the mixing state of BC as well as identification and quantification of BC sources. We used a combination of a Centrifugal Particle Mass Analyser (CPMA) and a Single Particle Soot Photometer (SP2) to uniquely quantify the morphology independent mass of single refractory BC particles and their coating content. The CPMA allows us to select pre-charged aerosol particles according to their mass to charge ratio and the SP2 provides information on the mass of refractory BC through a laser-induced incandescence method. Furthermore, another SP2 was used to measure the BC flux at 100m height using the Eddy Covariance method. We have successfully gathered 4 weeks of continuous measurements which include several severe pollution events in Beijing. Here we present preliminary results, characterising the distribution of coating mass on BC particles in Beijing and linking this to the main sources of BC in the city. We will provide initial estimates of the BC flux over a several kilometre footprint. Such analysis will provide important information for the further investigation of source distribution, emission, lifetime and optical properties of BC under complex environments in Beijing.

Latitudinal distribution of aerosol black carbon and its mass fraction to composite aerosols over peninsular India during winter season

NASA Astrophysics Data System (ADS)

Moorthy, K. Krishna; Babu, S. Suresh; Badarinath, K. V. S.; Sunilkumar, S. V.; Kiranchand, T. R.; Ahmed, Y. Nazeer

2007-04-01

During a land campaign to characterise the spatial distribution of aerosols over peninsular India during the winter season, extensive, collocated, and spatially resolved measurements of mass concentration of the composite aerosols (MT) as well as that (MB) of aerosol Black Carbon (BC) were made over different environments (coastal, industrial, urban, village, remote, semiarid) of the western peninsular India. High concentrations of BC, >2.5 μg m-3, were observed along the west coast, from ~8°N up to 14.5°N, and moderate values (1.0 to 2.5 μg m-3) over inland regions from 15 to 18°N. Latitudinally, BC concentration decreased from south to north, @~160 ng m-3 for every degree increase in latitude. The spatial pattern of BC mass fraction differed from that of MB, with regions of high (8 to 16%) ratios spreading more interior, implying higher fractional load of BC at locations where the BC concentrations remain lower.

Global-mean BC lifetime as an indicator of model skill? Constraining the vertical aerosol distribution using aircraft observations

NASA Astrophysics Data System (ADS)

Lund, M. T.; Samset, B. H.; Skeie, R. B.; Berntsen, T.

2017-12-01

Several recent studies have used observations from the HIPPO flight campaigns to constrain the modeled vertical distribution of black carbon (BC) over the Pacific. Results indicate a relatively linear relationship between global-mean atmospheric BC residence time, or lifetime, and bias in current models. A lifetime of less than 5 days is necessary for models to reasonably reproduce these observations. This is shorter than what many global models predict, which will in turn affect their estimates of BC climate impacts. Here we use the chemistry-transport model OsloCTM to examine whether this relationship between global BC lifetime and model skill also holds for a broader a set of flight campaigns from 2009-2013 covering both remote marine and continental regions at a range of latitudes. We perform four sets of simulations with varying scavenging efficiency to obtain a spread in the modeled global BC lifetime and calculate the model error and bias for each campaign and region. Vertical BC profiles are constructed using an online flight simulator, as well by averaging and interpolating monthly mean model output, allowing us to quantify sampling errors arising when measurements are compared with model output at different spatial and temporal resolutions. Using the OsloCTM coupled with a microphysical aerosol parameterization, we investigate the sensitivity of modeled BC vertical distribution to uncertainties in the aerosol aging and scavenging processes in more detail. From this, we can quantify how model uncertainties in the BC life cycle propagate into uncertainties in its climate impacts. For most campaigns and regions, a short global-mean BC lifetime corresponds with the lowest model error and bias. On an aggregated level, sampling errors appear to be small, but larger differences are seen in individual regions. However, we also find that model-measurement discrepancies in BC vertical profiles cannot be uniquely attributed to uncertainties in a single process or parameter, at least in this model. Model development therefore needs to focus on improvements to individual processes, supported by a broad range of observational and experimental data, rather than tuning individual, effective parameters such as global BC lifetime.

The physical properties of black carbon and other light-absorbing material emitted from prescribed fires in the United States

NASA Astrophysics Data System (ADS)

McMeeking, G. R.; Kreidenweis, S. M.; Yokelson, R. J.; Sullivan, A. P.; Lee, T.; Collett, J. L.; Fortner, E.; Onasch, T. B.; Akagi, S. K.; Taylor, J.; Coe, H.

2012-12-01

Black carbon (BC) aerosol emitted from fires absorbs light, leading to visibility degradation as well as regional and global climate impacts. Fires also emit a wide range of trace gases and particulates that can interact with emitted BC and alter its optical properties and atmospheric lifetime. Non-BC particulate species emitted by fires can also scatter and absorb light, leading to additional effects on visibility. Recent work has shown that certain organic species can absorb light strongly at shorter wavelengths, giving it a brown or yellow color. This material has been classified as brown carbon, though it is not yet well defined. Land managers must find a balance between the negative impacts of prescribed fire emissions on visibility and air quality and the need to prevent future catastrophic wildfire as well as manage ecosystems for habitat restoration or other purposes. This decision process requires accurate assessments of the visibility impacts of fire emissions, including BC and brown carbon, which in turn depend on their optical properties. We present recent laboratory and aircraft measurements of black carbon and aerosol optical properties emitted from biomass burning. All measurement campaigns included a single particle soot photometer (SP2) instrument capable of providing size-resolved measurements of BC mass and number distributions and mixing state, which are needed to separate the BC and brown carbon contributions to total light absorption. The laboratory experiments also included a three-wavelength photoacoustic spectrometer that provided accurate measurements of aerosol light absorption. The laboratory systems also characterized emissions after they had been treated with a thermal denuder to remove semi-volatile coatings, allowing an assessment of the role of non-BC coatings on bulk aerosol optical properties. Emissions were also aged in an environmental smog chamber to examine the role of secondary aerosol production on aerosol optical properties.

Plackett-Burman experimental design for bacterial cellulose-silica composites synthesis.

PubMed

Guzun, Anicuta Stoica; Stroescu, Marta; Jinga, Sorin Ion; Voicu, Georgeta; Grumezescu, Alexandru Mihai; Holban, Alina Maria

2014-09-01

Bacterial cellulose-silica hybrid composites were prepared starting from wet bacterial cellulose (BC) membranes using Stöber reaction. The structure and surface morphology of hybrid composites were examined by FTIR and SEM. The SEM pictures revealed that the silica particles are attached to BC fibrils and are well dispersed in the BC matrix. The influence of silica particles upon BC crystallinity was studied using XRD analysis. Thermogravimetric (TG) analysis showed that the composites are stable up to 300°C. A Plackett-Burman design was applied in order to investigate the influence of process parameters upon silica particle sizes and silica content of BC-silica composites. The statistical model predicted that it is possible for silica particles size to vary the synthesis parameters in order to obtain silica particles deposed on BC membranes in the range from 34.5 to 500 nm, the significant parameters being ammonia concentration, reaction time and temperature. The silica content also varies depending on process parameters, the statistical model predicting that the most influential parameters are water-tetraethoxysilane (TEOS) ratio and reaction temperature. The antimicrobial behavior on Staphylococcus aureus of BC-silica composites functionalized with usnic acid (UA) was also studied, in order to create improved surfaces with antiadherence and anti-biofilm properties. Copyright © 2014 Elsevier B.V. All rights reserved.

Distribution and Fate of Black Carbon Nanoparticles from Regional Urban Pollution and Wildfire at a Large Subalpine Lake in the Western United States

NASA Astrophysics Data System (ADS)

Bisiaux, M. M.; Heyvaert, A. C.; Edwards, R.

2012-04-01

Emitted to the atmosphere through fire and fossil fuel combustion, refractory black carbon nanoparticles (rBC) impact human health, climate, atmospheric chemistry, and the carbon cycle. Eventually these particles enter aquatic environments, where their distribution, fate and association with other pollutants are still poorly characterized. This study presents results from an evaluation of rBC in the waters of oligotrophic Lake Tahoe and its watershed in the western United States. The study period included a large wildfire within the Tahoe basin, seasonal snowmelt, and a number of storm events that resulted in pulsed urban runoff into the lake with rBC concentrations up to four orders of magnitude higher than mid-lake concentrations. The results show that elevated rBC concentrations from wildfire and urban runoff were rapidly attenuated in the lake, suggesting unexpected aggregation or degradation of the particles that prevent rBC concentrations from building up in the water of this lake, renowned for its clarity. The rBC concentrations were also measured in sediment cores from Lake Tahoe to evaluate the sediment archive as a potential combustion record. The evidence suggests that rBC is efficiently transferred to these sediments, which preserve a local-to-regional scale history of rBC emissions, as revealed by comparison with other pollutant records in the sediment. Rapid removal of rBC soon after entry into the lake has implications for transport of rBC in the global aquatic environment and flux of rBC from continents to the global ocean.

Examination of Broad Symptom Improvement Resulting From Mindfulness-Based Stress Reduction in Breast Cancer Survivors: A Randomized Controlled Trial

PubMed Central

Reich, Richard R.; Paterson, Carly L.; Ramesar, Sophia; Park, Jong Y.; Alinat, Carissa; Johnson-Mallard, Versie; Moscoso, Manolete; Budhrani-Shani, Pinky; Miladinovic, Branko; Jacobsen, Paul B.; Cox, Charles E.; Goodman, Matthew; Kip, Kevin E.

2016-01-01

Purpose The purpose of this randomized trial was to evaluate the efficacy of the Mindfulness-Based Stress Reduction for Breast Cancer (MBSR[BC]) program in improving psychological and physical symptoms and quality of life among breast cancer survivors (BCSs) who completed treatment. Outcomes were assessed immediately after 6 weeks of MBSR(BC) training and 6 weeks later to test efficacy over an extended timeframe. Patients and Methods A total of 322 BCSs were randomly assigned to either a 6-week MBSR(BC) program (n = 155) or a usual care group (n = 167). Psychological (depression, anxiety, stress, and fear of recurrence) and physical symptoms (fatigue and pain) and quality of life (as related to health) were assessed at baseline and at 6 and 12 weeks. Linear mixed models were used to assess MBSR(BC) effects over time, and participant characteristics at baseline were also tested as moderators of MBSR(BC) effects. Results Results demonstrated extended improvement for the MBSR(BC) group compared with usual care in both psychological symptoms of anxiety, fear of recurrence overall, and fear of recurrence problems and physical symptoms of fatigue severity and fatigue interference (P < .01). Overall effect sizes were largest for fear of recurrence problems (d = 0.35) and fatigue severity (d = 0.27). Moderation effects showed BCSs with the highest levels of stress at baseline experienced the greatest benefit from MBSR(BC). Conclusion The MBSR(BC) program significantly improved a broad range of symptoms among BCSs up to 6 weeks after MBSR(BC) training, with generally small to moderate overall effect sizes. PMID:27247219

Impact of polymer electrolyte membrane fuel cell microporous layer nano-scale features on thermal conductance

NASA Astrophysics Data System (ADS)

Botelho, S. J.; Bazylak, A.

2015-04-01

In this study, the microporous layer (MPL) of the polymer electrolyte membrane (PEM) fuel cell was analysed at the nano-scale. Atomic force microscopy (AFM) was utilized to image the top layer of MPL particles, and a curve fitting algorithm was used to determine the particle size and filling radius distributions for SGL-10BB and SGL-10BC. The particles in SGL-10BC (approximately 60 nm in diameter) have been found to be larger than those in SGL-10BB (approximately 40 nm in diameter), highlighting structural variability between the two materials. The impact of the MPL particle interactions on the effective thermal conductivity of the bulk MPL was analysed using a discretization of the Fourier equation with the Gauss-Seidel iterative method. It was found that the particle spacing and filling radius dominates the effective thermal conductivity, a result which provides valuable insight for future MPL design.

Unifying distance-based goodness-of-fit indicators for hydrologic model assessment

NASA Astrophysics Data System (ADS)

Cheng, Qinbo; Reinhardt-Imjela, Christian; Chen, Xi; Schulte, Achim

2014-05-01

The goodness-of-fit indicator, i.e. efficiency criterion, is very important for model calibration. However, recently the knowledge about the goodness-of-fit indicators is all empirical and lacks a theoretical support. Based on the likelihood theory, a unified distance-based goodness-of-fit indicator termed BC-GED model is proposed, which uses the Box-Cox (BC) transformation to remove the heteroscedasticity of model errors and the generalized error distribution (GED) with zero-mean to fit the distribution of model errors after BC. The BC-GED model can unify all recent distance-based goodness-of-fit indicators, and reveals the mean square error (MSE) and the mean absolute error (MAE) that are widely used goodness-of-fit indicators imply statistic assumptions that the model errors follow the Gaussian distribution and the Laplace distribution with zero-mean, respectively. The empirical knowledge about goodness-of-fit indicators can be also easily interpreted by BC-GED model, e.g. the sensitivity to high flow of the goodness-of-fit indicators with large power of model errors results from the low probability of large model error in the assumed distribution of these indicators. In order to assess the effect of the parameters (i.e. the BC transformation parameter λ and the GED kurtosis coefficient β also termed the power of model errors) of BC-GED model on hydrologic model calibration, six cases of BC-GED model were applied in Baocun watershed (East China) with SWAT-WB-VSA model. Comparison of the inferred model parameters and model simulation results among the six indicators demonstrates these indicators can be clearly separated two classes by the GED kurtosis β: β >1 and β ≤ 1. SWAT-WB-VSA calibrated by the class β >1 of distance-based goodness-of-fit indicators captures high flow very well and mimics the baseflow very badly, but it calibrated by the class β ≤ 1 mimics the baseflow very well, because first the larger value of β, the greater emphasis is put on high flow and second the derivative of GED probability density function at zero is zero as β >1, but discontinuous as β ≤ 1, and even infinity as β < 1 with which the maximum likelihood estimation can guarantee the model errors approach zero as well as possible. The BC-GED that estimates the parameters (i.e. λ and β) of BC-GED model as well as hydrologic model parameters is the best distance-based goodness-of-fit indicator because not only the model validation using groundwater levels is very good, but also the model errors fulfill the statistic assumption best. However, in some cases of model calibration with a few observations e.g. calibration of single-event model, for avoiding estimation of the parameters of BC-GED model the MAE i.e. the boundary indicator (β = 1) of the two classes, can replace the BC-GED, because the model validation of MAE is best.

Geomicrobiology of the Ocean Crust: The Phylogenetic Diversity, Abundance, and Distribution of Microbial Communities Inhabiting Basalt and Implications for Rock Alteration Processes

DTIC Science & Technology

2007-06-01

AF317741) 93 EPR3970- MOlA -Bc32 gamma-Proteobacteria Uncultured gamma proteobacterium clone AT-s80 (AY225635) 99 FPR3970-MO IA-Bc33 Actinobacteria...bacterium partial I AJ966584) 99 1iPR3970- MOlA -Bc65 Unidentified Uncultured bacterium clone CV90 (DQ499320) 89 1iPR3970- MOlA -Bc66 Unidentified Uncultured

A 65 Ah rechargeable lithium molybdenum disulfide battery

NASA Technical Reports Server (NTRS)

Brandt, K.

1986-01-01

A rechargeable lithium molybdenum disulfide battery which has a number of superior performance characteristics which includes a high energy density, a high power density, and a long charge retention time was developed. The first cell sizes developed included a C size cell and an AA size cell. Over the last two years, a project to demonstrate the feasibility of the scale up to this technology to a BC size cell with 65 Ah capacity was undertaken. The objective was to develop, build, and test a .6 kWh storage battery consisting of 6 BC cells in series.

Surface functional group dependent apatite formation on bacterial cellulose microfibrils network in a simulated body fluid.

PubMed

Nge, Thi Thi; Sugiyama, Junji

2007-04-01

The apatite forming ability of biopolymer bacterial cellulose (BC) has been investigated by soaking different BC specimens in a simulated body fluid (1.5 SBF) under physiological conditions, at 37 degrees C and pH 7.4, mimicking the natural process of apatite formation. From ATR-FTIR spectra and ICP-AES analysis, the crystalline phase nucleated on the BC microfibrils surface was calcium deficient carbonated apatite through initial formation of octacalcium phosphate (OCP) or OCP like calcium phosphate phase regardless of the substrates. Morphology of the deposits from SEM, FE-SEM, and TEM observations revealed the fine structure of thin film plates uniting together to form apatite globules of various size (from <1 mum to 3 mum) with respect to the substrates. Surface modification by TEMPO (2,2,6,6-tetramethylpyperidine-1-oxyl)-mediated oxidation, which can readily form active carboxyl functional groups upon selective oxidation of primary hydroxyl groups on the surface of BC microfibrils, enhanced the rate of apatite nucleation. Ion exchanged treatment with calcium chloride solution after TEMPO-mediated oxidation was found to be remarkably different from other BC substrates with the highest deposit weight and the smallest apatite globules size. The role of BC substrates to induce mineralization rate differs according to the nature of the BC substrates, which strongly influences the growth behavior of the apatite crystals. (c) 2006 Wiley Periodicals, Inc.

Impact of Wet Deposition of Black Carbon on Particle Dynamics in Surface Waters of Halong Bay, North Vietnam

NASA Astrophysics Data System (ADS)

Mari, X.; Guinot, B. P.; Thuoc, C. V.; Brune, J.; Lefebvre, J. P.; Raimbault, P.; Niggemann, J.; Dittmar, T.

2016-02-01

Black Carbon (BC) is an aerosol emitted during biomass burning and fossil fuel combustion. The atmospheric lifetime of Black Carbon (BC) ranges from a few days in rainy climates up to one month in dry regions, and on a global scale wet deposition of atmospheric BC accounts for about 80% of the BC input to the ocean. The rain-mediated input of BC to the ocean was studied in a coastal site located in a regional hotspot of atmospheric BC concentration, North Vietnam. We monitored changes in atmospheric and marine BC during a 24-h cycle impacted by a short and heavy rainfall event. During the rainfall event, atmospheric BC concentration decreased by a factor of 8 (i.e. from 5230 to 660 µg BC m-3). This cleaning of the air column was immediately followed by a significant increase (by a factor of 2 to 4) of particulate BC (PBC) and POC concentrations in the surface microlayer (SML) and at 1.5 m depth. In the SML, this event was also followed by a significant increase of DOC and dissolved BC (DBC) concentrations. Interestingly, the concentration of DOC decreased by >10% after the rainfall at 1.5 m depth, suggesting an adsorption of DOC onto sinking PBC. Concomitantly with the increase in particulate BC, nutrient concentrations increased by a factor of 2 in the SML, while no change was observed in the underlying water column. After the rainfall, the particle size spectra, measured along the water column with a LISST (Laser In-Situ Scattering and Transmissometry probe), changed in that the concentration of small particles (<5 µm) decreased and the concentration of large particles (>100 µm) increased. This alteration of the particle size spectra was restricted to a thin layer of about 20 cm thickness, probably corresponding to a BC-enriched layer adsorbing DOC and small particles, and stimulating aggregation during sinking from the surface to deeper water layers. The concentrations of POC, DOC, PBC, DBC and nutrients reached pre-rainfall levels 4 hours after the event.

Sources and mixing state of size-resolved elemental carbon particles in a European megacity: Paris

NASA Astrophysics Data System (ADS)

Healy, R. M.; Sciare, J.; Poulain, L.; Kamili, K.; Merkel, M.; Müller, T.; Wiedensohler, A.; Eckhardt, S.; Stohl, A.; Sarda-Estève, R.; McGillicuddy, E.; O'Connor, I. P.; Sodeau, J. R.; Wenger, J. C.

2012-02-01

An Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS) was deployed to investigate the size-resolved chemical composition of single particles at an urban background site in Paris, France, as part of the MEGAPOLI winter campaign in January/February 2010. ATOFMS particle counts were scaled to match coincident Twin Differential Mobility Particle Sizer (TDMPS) data in order to generate hourly size-resolved mass concentrations for the single particle classes observed. The total scaled ATOFMS particle mass concentration in the size range 150-1067 nm was found to agree very well with the sum of concurrent High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and Multi-Angle Absorption Photometer (MAAP) mass concentration measurements of organic carbon (OC), inorganic ions and black carbon (BC) (R2 = 0.91). Clustering analysis of the ATOFMS single particle mass spectra allowed the separation of elemental carbon (EC) particles into four classes: (i) EC attributed to biomass burning (ECbiomass), (ii) EC attributed to traffic (ECtraffic), (iii) EC internally mixed with OC and ammonium sulfate (ECOCSOx), and (iv) EC internally mixed with OC and ammonium nitrate (ECOCNOx). Average hourly mass concentrations for EC-containing particles detected by the ATOFMS were found to agree reasonably well with semi-continuous quantitative thermal/optical EC and optical BC measurements (r2 = 0.61 and 0.65-0.68 respectively, n = 552). The EC particle mass assigned to fossil fuel and biomass burning sources also agreed reasonably well with BC mass fractions assigned to the same sources using seven-wavelength aethalometer data (r2 = 0.60 and 0.48, respectively, n = 568). Agreement between the ATOFMS and other instrumentation improved noticeably when a period influenced by significantly aged, internally mixed EC particles was removed from the intercomparison. 88% and 12% of EC particle mass was apportioned to fossil fuel and biomass burning respectively using the ATOFMS data compared with 85% and 15% respectively for BC estimated from the aethalometer model. On average, the mass size distribution for EC particles is bimodal; the smaller mode is attributed to locally emitted, mostly externally mixed EC particles, while the larger mode is dominated by aged, internally mixed ECOCNOx particles associated with continental transport events. Periods of continental influence were identified using the Lagrangian Particle Dispersion Model (LPDM) "FLEXPART". A consistent minimum between the two EC mass size modes was observed at approximately 400 nm for the measurement period. EC particles below this size are attributed to local emissions using chemical mixing state information and contribute 79% of the scaled ATOFMS EC particle mass, while particles above this size are attributed to continental transport events and contribute 21% of the EC particle mass. These results clearly demonstrate the potential benefit of monitoring size-resolved mass concentrations for the separation of local and continental EC emissions. Knowledge of the relative input of these emissions is essential for assessing the effectiveness of local abatement strategies.

Effect of boundary conditions on the numerical solutions of representative volume element problems for random heterogeneous composite microstructures

NASA Astrophysics Data System (ADS)

Cho, Yi Je; Lee, Wook Jin; Park, Yong Ho

2014-11-01

Aspects of numerical results from computational experiments on representative volume element (RVE) problems using finite element analyses are discussed. Two different boundary conditions (BCs) are examined and compared numerically for volume elements with different sizes, where tests have been performed on the uniaxial tensile deformation of random particle reinforced composites. Structural heterogeneities near model boundaries such as the free-edges of particle/matrix interfaces significantly influenced the overall numerical solutions, producing force and displacement fluctuations along the boundaries. Interestingly, this effect was shown to be limited to surface regions within a certain distance of the boundaries, while the interior of the model showed almost identical strain fields regardless of the applied BCs. Also, the thickness of the BC-affected regions remained constant with varying volume element sizes in the models. When the volume element size was large enough compared to the thickness of the BC-affected regions, the structural response of most of the model was found to be almost independent of the applied BC such that the apparent properties converged to the effective properties. Finally, the mechanism that leads a RVE model for random heterogeneous materials to be representative is discussed in terms of the size of the volume element and the thickness of the BC-affected region.

Role of black carbon in the sorption of polychlorinated dibenzo-p-dioxins and dibenzofurans at the Diamond Alkali superfund site, Newark Bay, New Jersey.

PubMed

Lambert, Matthew K; Friedman, Carey; Luey, Pamela; Lohmann, Rainer

2011-05-15

The sorption of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) to organic carbon (OC) and black carbon (BC) was measured in two sediment cores taken near the Diamond Alkali superfund site (DA) in the Passaic River and Newark Bay, New Jersey (U.S.A.). An OC partitioning model and a BC-inclusive, Freundlich distribution model were used to interpret measurements of freely dissolved PCDD/Fs using passive samplers in sediment incubations, together with measured sedimentary concentrations of OC, BC, and PCDD/Fs. Samples were also analyzed for polycyclic aromatic hydrocarbons (PAHs) as controls on the two distribution models. The OC partitioning model underpredicted the distribution of PAHs and PCDD/Fs by 10-100-fold. The Freundlich model predicted the distribution of PAHs at the DA to within a factor of 2-3 of observations. Black carbon-water partition coefficients (K(iBC)) for PCDD/Fs, derived from literature results of both field and laboratory studies differed up to 1000-fold from values derived from this study. Contrary to expectations, PCDDs displayed stronger sorption than either PCDFs or PAHs relative to their subcooled liquid aqueous solubilities. Even though the presence of BC in the sediments reduced the overall bioavailability of PCDD/Fs by >90%, the sediments at 2 m depth continue to display the highest pore water activities of PCDD/Fs.

The single-particle mixing state and cloud scavenging of black carbon: a case study at a high-altitude mountain site in southern China

NASA Astrophysics Data System (ADS)

Zhang, Guohua; Lin, Qinhao; Peng, Long; Bi, Xinhui; Chen, Duohong; Li, Mei; Li, Lei; Brechtel, Fred J.; Chen, Jianxin; Yan, Weijun; Wang, Xinming; Peng, Ping'an; Sheng, Guoying; Zhou, Zhen

2017-12-01

In the present study, a ground-based counterflow virtual impactor (GCVI) was used to sample cloud droplet residual (cloud RES) particles, while a parallel PM2.5 inlet was used to sample cloud-free or cloud interstitial (cloud INT) particles. The mixing state of black carbon (BC)-containing particles and the mass concentrations of BC in the cloud-free, RES and INT particles were investigated using a single-particle aerosol mass spectrometer (SPAMS) and two aethalometers, respectively, at a mountain site (1690 m a. s. l. ) in southern China. The measured BC-containing particles were extensively internally mixed with sulfate and were scavenged into cloud droplets (with number fractions of 0.05-0.45) to a similar (or slightly lower) extent as all the measured particles (0.07-0.6) over the measured size range of 0.1-1.6 µm. The results indicate the preferential activation of larger particles and/or that the production of secondary compositions shifts the BC-containing particles towards larger sizes. BC-containing particles with an abundance of both sulfate and organics were scavenged less than those with sulfate but limited organics, implying the importance of the mixing state on the incorporation of BC-containing particles into cloud droplets. The mass scavenging efficiency of BC with an average of 33 % was similar for different cloud events independent of the air mass. This is the first time that both the mixing state and cloud scavenging of BC in China have been reported. Our results would improve the knowledge on the concentration, mixing state, and cloud scavenging of BC in the free troposphere.

Black carbon vertical profiles strongly affect its radiative forcing uncertainty

NASA Astrophysics Data System (ADS)

Samset, B. H.; Myhre, G.; Schulz, M.; Balkanski, Y.; Bauer, S.; Berntsen, T. K.; Bian, H.; Bellouin, N.; Diehl, T.; Easter, R. C.; Ghan, S. J.; Iversen, T.; Kinne, S.; Kirkevåg, A.; Lamarque, J.-F.; Lin, G.; Liu, X.; Penner, J.; Seland, Ø.; Skeie, R. B.; Stier, P.; Takemura, T.; Tsigaridis, K.; Zhang, K.

2012-11-01

The impact of black carbon (BC) aerosols on the global radiation balance is not well constrained. Here twelve global aerosol models are used to show that at least 20% of the present uncertainty in modeled BC direct radiative forcing (RF) is due to diversity in the simulated vertical profile of BC mass. Results are from phases 1 and 2 of the global aerosol model intercomparison project (AeroCom). Additionally, a significant fraction of the variability is shown to come from high altitudes, as, globally, more than 40% of the total BC RF is exerted above 5 km. BC emission regions and areas with transported BC are found to have differing characteristics. These insights into the importance of the vertical profile of BC lead us to suggest that observational studies are needed to better characterize the global distribution of BC, including in the upper troposphere.

Black carbon vertical profiles strongly affect its radiative forcing uncertainty

NASA Astrophysics Data System (ADS)

Samset, B. H.; Myhre, G.; Schulz, M.; Balkanski, Y.; Bauer, S.; Berntsen, T. K.; Bian, H.; Bellouin, N.; Diehl, T.; Easter, R. C.; Ghan, S. J.; Iversen, T.; Kinne, S.; Kirkevåg, A.; Lamarque, J.-F.; Lin, G.; Liu, X.; Penner, J. E.; Seland, Ø.; Skeie, R. B.; Stier, P.; Takemura, T.; Tsigaridis, K.; Zhang, K.

2013-03-01

The impact of black carbon (BC) aerosols on the global radiation balance is not well constrained. Here twelve global aerosol models are used to show that at least 20% of the present uncertainty in modeled BC direct radiative forcing (RF) is due to diversity in the simulated vertical profile of BC mass. Results are from phases 1 and 2 of the global aerosol model intercomparison project (AeroCom). Additionally, a significant fraction of the variability is shown to come from high altitudes, as, globally, more than 40% of the total BC RF is exerted above 5 km. BC emission regions and areas with transported BC are found to have differing characteristics. These insights into the importance of the vertical profile of BC lead us to suggest that observational studies are needed to better characterize the global distribution of BC, including in the upper troposphere.

Black Carbon Vertical Profiles Strongly Affect Its Radiative Forcing Uncertainty

NASA Technical Reports Server (NTRS)

Samset, B. H.; Myhre, G.; Schulz, M.; Balkanski, Y.; Bauer, S.; Berntsen, T. K.; Bian, H.; Bellouin, N.; Diehl, T.; Easter, R. C.;

Body composition and body fat distribution are related to cardiac autonomic control in non-alcoholic fatty liver disease patients.

PubMed

Pimenta, N M; Santa-Clara, H; Cortez-Pinto, H; Silva-Nunes, J; da Lapa Rosado, M; Sousa, P J; Calé, R; Melo, X; Sardinha, L B; Fernhall, B

2014-02-01

Heart rate recovery (HRR), a cardiac autonomic control marker, was shown to be related to body composition (BC), yet this was not tested in non-alcoholic fatty liver disease (NAFLD) patients. The aim of this study was to determine if, and to what extent, markers of BC and body fat (BF) distribution are related to cardiac autonomic control in NAFLD patients. BC was assessed with dual-energy X-ray absorptiometry in 28 NAFLD patients (19 men, 51±13 years, and 9 women, 47±13 years). BF depots ratios were calculated to assess BF distribution. Subjects' HRR was recorded 1 (HRR1) and 2 min (HRR2) immediately after a maximum graded exercise test. BC and BF distribution were related to HRR; particularly weight, trunk BF and trunk BF-to-appendicular BF ratio showed a negative relation with HRR1 (r=-0.613, r=-0.597 and r=-0.547, respectively, P<0.01) and HRR2 (r=-0.484, r=-0.446, P<0.05, and r=-0.590, P<0.01, respectively). Age seems to be related to both HRR1 and HRR2 except when controlled for BF distribution. The preferred model in multiple regression should include trunk BF-to-appendicular BF ratio and BF to predict HRR1 (r2=0.549; P<0.05), and trunk BF-to-appendicular BF ratio alone to predict HRR2 (r2=0.430; P<0.001). BC and BF distribution were related to HRR in NAFLD patients. Trunk BF-to-appendicular BF ratio was the best independent predictor of HRR and therefore may be best related to cardiovascular increased risk, and possibly act as a mediator in age-related cardiac autonomic control variation.

HD-SP2 Measurements of Black Carbon Containing Aerosols in South Korea during KORUS-AQ

NASA Astrophysics Data System (ADS)

Lamb, K. D.; Perring, A. E.; Ahn, J.; Schwarz, J. P.

2016-12-01

Black carbon (BC) is a light-absorbing aerosol with strong anthropogenic sources that has important climatic and health impacts, both regionally and globally. Materials internally mixed with BC, including water, affect its optical properties and lifetime in the atmosphere, and thus are critical to determining BC's ultimate impacts. The NASA KORUS-AQ campaign during the spring/summer of 2016 was a multi-platform research campaign focused on air quality over South Korea, in a region with particularly high BC emissions and loadings. The NOAA Humidified-Dual Single Particle Soot Photometer (HD-SP2) was deployed on the NASA DC-8 aircraft to measure the optical size and refractory BC content of individual particles under dry and humidified conditions as well as the BC mass mixing ratio. We focus on evaluating BC MMR in the free troposphere up to 400 hPa in the context of previous measurements; assessing the optical impacts of observed internal mixtures with BC at different times of day; and evaluating the contribution of water uptake on BC absorption and atmospheric lifetime over Korea in ambient conditions.

Characterization of carbonaceous aerosols during the MINOS campaign in Crete, July August 2001: a multi-analytical approach

NASA Astrophysics Data System (ADS)

Sciare, J.; Cachier, H.; Oikonomou, K.; Ausset, P.; Sarda-Estève, R.; Mihalopoulos, N.

2003-10-01

During the major part of the Mediterranean Intensive Oxidant Study (MINOS) campaign (summer 2001, Crete Isl.), the Marine Boundary Layer (MBL) air was influenced by long range transport of biomass burning from the northern and western part of the Black Sea. During this campaign, carbonaceous aerosols were collected on quartz filters at a Free Tropospheric (FT) site, and at a MBL site together with size-resolved distribution of aerosols. Three Evolution Gas Analysis (EGA) protocols have been tested in order to better characterize the collected aged biomass burning smoke: A 2-step thermal method (Cachier et al., 1989) and a thermo-optical technique using two different temperature programs. The later temperature programs are those used for IMPROVE (Interagency Monitoring of Protected Visual Environments) and NIOSH 5040 (National Institute of Occupational Safety and Health). Artifacts were observed using the NIOSH temperature program and identified as interactions between carbon and dust deposited on the filter matrix at high temperature (T>550ºC) under the pure helium step of the analysis. During the MINOS campaign, Black Carbon (BC) and Organic Carbon (OC) mass concentrations were on average respectively 1.19±0.56 and 3.62±1.08 mgC/m3 for the IMPROVE temperature program, and 1.09±0.36 and 3.75±1.24 mgC/m3 for the thermal method. Though these values compare well on average and the agreement between the Total Carbon (TC) measurements sample to sample was excellent (slope=1.00, r2=0.93, n=56), important discrepancies were observed in determining BC concentrations from these two methods (average error of 33±22%). BC from the IMPROVE temperature program compared well with non-sea-salt potassium (nss-K) pointing out an optical sensitivity to biomass burning. On the other hand, BC from the thermal method showed a better agreement with non-sea-salt sulfate (nss-SO4), considered as a tracer for fossil fuel combustion during the MINOS campaign. The coupling between these two methods for determining BC brings here new insights on the origin of carbonaceous aerosols in a complex mixture of different sources. It brings also to our attention that important deviations in BC levels are observed using three widely used EGA's techniques and most probably none of the EGA tested here are well adapted to fully characterize this aerosol mixture. Spherical, smooth and silico-aluminated fly-ash observed by an Analytical Scanning Electron Microscope (ASEM) confirm the influence of coal combustion on the carbonaceous aerosol load throughout the campaign. A rough calculation based on a BC/nss-SO4 mass ratio suggests that biomass burning could be responsible for half of the BC concentration recorded during the MINOS campaign. From the plot of BC as a function of TC, two linear correlations were observed corresponding to 2 times series (before and after 12 August). Such good correlations suggest, from a first look, that both BC and OC have similar origin and atmospheric transport. On the other hand, the plot of BC as a function of TC obtained from the 2-step thermal method applied to DEKATI Low Pressure Cascade Impactor samples does not show a similar correlation and points out a non conservative distribution of this ratio with 2 super micron modes enriched in OC, correlated with sea salt aerosols and probably originating from gas-to-particle conversion.

Characterization of carbonaceous aerosols during the MINOS campaign in Crete, July-August 2001: a multi-analytical approach

NASA Astrophysics Data System (ADS)

Sciare, J.; Cachier, H.; Oikonomou, K.; Ausset, P.; Sarda-Estève, R.; Mihalopoulos, N.

2003-07-01

During the major part of the Mediterranean Intensive Oxidant Study (MINOS) campaign (summer 2001, Crete Isl.), the Marine Boundary Layer (MBL) air was influenced by long range transport of biomass burning from the northern and western part of the Black Sea. During this campaign, carbonaceous aerosols were collected on quartz filters at a Free Tropospheric (FT) site, and at a MBL site together with size-resolved distribution of aerosols. Three Evolution Gas Analysis (EGA) protocols have been tested in order to better characterize the collected aged biomass burning smoke: A 2-step thermal method (Cachier et al., 1989) and a thermo-optical technique using two different temperature programs. The later temperature programs are those used for IMPROVE (Interagency Monitoring of Protected Visual Environments) and NIOSH 5040 (National Institute of Occupational Safety and Health). Artifacts were observed using the NIOSH temperature program and identified as interactions between carbon and dust deposited on the filter matrix at high temperature (T=550°C) under the pure helium step of the analysis. During the MINOS campaign, Black Carbon (BC) and Organic Carbon (OC) concentrations were on average respectively 1.19±0.56 and 3.62±1.08 μgC/m3 for the IMPROVE temperature program, and 1.09±0.36 and 3.75±1.24 μgC/m3 for the thermal method. Though these values compare well on average and the agreement between the Total Carbon (TC) measurements sample to sample was excellent (slope = 1.00, r2=0.93, n=56), important discrepancies were observed in determining BC concentrations from these two methods (average error of 33±22%). BC from the IMPROVE temperature program compared well with non-sea-salt potassium (nss-K) pointing out an optical sensitivity to biomass burning. On the other hand, BC from the thermal method showed a better agreement with non-sea-salt sulfate (nss-SO4), considered as a tracer for fossil fuel combustion during the MINOS campaign. The coupling between these two methods for determining BC brings here new insights on the origin of carbonaceous aerosols in a complex mixture of different sources. It brings also to our attention that important deviations in BC levels are observed using three widely used EGA techniques and most probably none of the EGA tested here are well adapted to fully characterize this aerosol mixture. Spherical, smooth and silico-aluminated fly-ash observed by Analytical Scanning Electron Microscope (ASEM) confirm the influence of coal combustion on the carbonaceous aerosol load throughout the campaign. A raw calculation based on BC/nss-SO4 mass ratio suggests that biomass burning could be responsible for half of the BC concentration recorded during the MINOS campaign. From the plot of BC as a function of TC, two linear correlations were observed corresponding to 2 times series (before and after 12 August). Such good correlations suggest, from a first look, that both BC and OC have similar origin and atmospheric transport. On the other hand, the plot of BC as a function of TC obtained from the 2-step thermal method applied to DEKATI Low Pressure Cascade Impactor samples does not show a similar correlation and points out a non conservative distribution of this ratio with 2 super micron modes enriched in OC, correlated with sea salt aerosols and probably originating from gas-to-particle conversion.

Biomass burning emissions of trace gases and particles in marine air at Cape Grim, Tasmania

NASA Astrophysics Data System (ADS)

Lawson, S. J.; Keywood, M. D.; Galbally, I. E.; Gras, J. L.; Cainey, J. M.; Cope, M. E.; Krummel, P. B.; Fraser, P. J.; Steele, L. P.; Bentley, S. T.; Meyer, C. P.; Ristovski, Z.; Goldstein, A. H.

2015-12-01

Biomass burning (BB) plumes were measured at the Cape Grim Baseline Air Pollution Station during the 2006 Precursors to Particles campaign, when emissions from a fire on nearby Robbins Island impacted the station. Measurements made included non-methane organic compounds (NMOCs) (PTR-MS), particle number size distribution, condensation nuclei (CN) > 3 nm, black carbon (BC) concentration, cloud condensation nuclei (CCN) number, ozone (O3), methane (CH4), carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), nitrous oxide (N2O), halocarbons and meteorology. During the first plume strike event (BB1), a 4 h enhancement of CO (max ~ 2100 ppb), BC (~ 1400 ng m-3) and particles > 3 nm (~ 13 000 cm-3) with dominant particle mode of 120 nm were observed overnight. A wind direction change lead to a dramatic reduction in BB tracers and a drop in the dominant particle mode to 50 nm. The dominant mode increased in size to 80 nm over 5 h in calm sunny conditions, accompanied by an increase in ozone. Due to an enhancement in BC but not CO during particle growth, the presence of BB emissions during this period could not be confirmed. The ability of particles > 80 nm (CN80) to act as CCN at 0.5 % supersaturation was investigated. The ΔCCN / ΔCN80 ratio was lowest during the fresh BB plume (56 ± 8 %), higher during the particle growth period (77 ± 4 %) and higher still (104 ± 3 %) in background marine air. Particle size distributions indicate that changes to particle chemical composition, rather than particle size, are driving these changes. Hourly average CCN during both BB events were between 2000 and 5000 CCN cm-3, which were enhanced above typical background levels by a factor of 6-34, highlighting the dramatic impact BB plumes can have on CCN number in clean marine regions. During the 29 h of the second plume strike event (BB2) CO, BC and a range of NMOCs including acetonitrile and hydrogen cyanide (HCN) were clearly enhanced and some enhancements in O3 were observed (ΔO3 / ΔCO 0.001-0.074). A short-lived increase in NMOCs by a factor of 10 corresponded with a large CO enhancement, an increase of the NMOC / CO emission ratio (ER) by a factor of 2-4 and a halving of the BC / CO ratio. Rainfall on Robbins Island was observed by radar during this period which likely resulted in a lower fire combustion efficiency, and higher emission of compounds associated with smouldering. This highlights the importance of relatively minor meteorological events on BB emission ratios. Emission factors (EFs) were derived for a range of trace gases, some never before reported for Australian fires, (including hydrogen, phenol and toluene) using the carbon mass balance method. This provides a unique set of EFs for Australian coastal heathland fires. Methyl halide EFs were higher than EFs reported from other studies in Australia and the Northern Hemisphere which is likely due to high halogen content in vegetation on Robbins Island. This work demonstrates the substantial impact that BB plumes can have on the composition of marine air, and the significant changes that can occur as the plume interacts with terrestrial, aged urban and marine emission sources.

Molecular epidemiology of Mycobacterium tuberculosis in Baja California, Mexico: A result of human migration?

PubMed

Flores-López, Carlos A; Zenteno-Cuevas, Roberto; Laniado-Laborín, Rafael; Reynaud, Yann; García-Ortiz, Rosa Alejandra; González-Y-Merchand, Jorge A; Rivera, Sandra; Vázquez-Chacón, Carlos A; Vaughan, Gilberto; Martínez-Guarneros, José Armando; Victoria-Cota, Nelva Lorena; Cruz-Rivera, Mayra; Rastogi, Nalin; Muñiz-Salazar, Raquel

2017-11-01

The State of Baja California (BC) exhibits the highest incidence and prevalence rates of tuberculosis (TB), and multidrug-resistant TB (MDR-TB) in Mexico. However information about the circulation of M. tuberculosis lineages in BC and Mexico as a whole is limited. Here, we describe the genetic relationship and genetic diversity among M. tuberculosis clinical isolates (n=140) collected in BC between October 2009 and April 2011 with other regions of Mexico, the United States, and Latin America. All specimens were genotyped based on 24 mycobacterial interspersed repetitive units (MIRU)-variable number of tandem repeats (VNTR) loci. Population structure and minimum spanning tree (MST) analyses were used to assess the genetic diversity and distribution of BC isolates in comparison to USA and South America strains. Among the nine lineages observed, LAM, Haarlem and S were the most frequent identified in BC. Population structure analysis clustered most BC isolates (41%) into three distinctive groups that included strains from San Diego and South America, whereas other BC strains (22%) clustered with other Mexican strains. A subset of isolates (12%) seemed to be autochthonous of BC, while 25% were cosmopolitan and grouped into multiple clusters. It is highly likely that the TB genetic structure observed in BC is due to human migration. Additional studies are required to determine the mechanism involved in the phylogeographic distribution of M. tuberculosis in Mexico. Implementation of domestic molecular TB surveillance programs is required to better understand the molecular epidemiology of TB not only in the region but at the national level. Copyright © 2016 Elsevier B.V. All rights reserved.

Spatial and kinematic distributions of transition populations in intermediate redshift galaxy clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crawford, Steven M.; Wirth, Gregory D.; Bershady, Matthew A., E-mail: crawford@saao.ac.za, E-mail: wirth@keck.hawaii.edu, E-mail: mab@astro.wisc.edu

2014-05-01

We analyze the spatial and velocity distributions of confirmed members in five massive clusters of galaxies at intermediate redshift (0.5 < z < 0.9) to investigate the physical processes driving galaxy evolution. Based on spectral classifications derived from broad- and narrow-band photometry, we define four distinct galaxy populations representing different evolutionary stages: red sequence (RS) galaxies, blue cloud (BC) galaxies, green valley (GV) galaxies, and luminous compact blue galaxies (LCBGs). For each galaxy class, we derive the projected spatial and velocity distribution and characterize the degree of subclustering. We find that RS, BC, and GV galaxies in these clusters havemore » similar velocity distributions, but that BC and GV galaxies tend to avoid the core of the two z ≈ 0.55 clusters. GV galaxies exhibit subclustering properties similar to RS galaxies, but their radial velocity distribution is significantly platykurtic compared to the RS galaxies. The absence of GV galaxies in the cluster cores may explain their somewhat prolonged star-formation history. The LCBGs appear to have recently fallen into the cluster based on their larger velocity dispersion, absence from the cores of the clusters, and different radial velocity distribution than the RS galaxies. Both LCBG and BC galaxies show a high degree of subclustering on the smallest scales, leading us to conclude that star formation is likely triggered by galaxy-galaxy interactions during infall into the cluster.« less

Improved perturbative QCD formalism for Bc meson decays

NASA Astrophysics Data System (ADS)

Liu, Xin; Li, Hsiang-nan; Xiao, Zhen-Jun

2018-06-01

We derive the kT resummation for doubly heavy-flavored Bc meson decays by including the charm quark mass effect into the known formula for a heavy-light system. The resultant Sudakov factor is employed in the perutrbative QCD study of the "golden channel" Bc+→J /ψ π+. With a reasonable model for the Bc meson distribution amplitude, which maintains approximate on-shell conditions of both the partonic bottom and charm quarks, it is observed that the imaginary piece of the Bc→J /ψ transition form factor appears to be power suppressed, and the Bc+→J /ψ π+ branching ratio is not lower than 10-3. The above improved perturbative QCD formalism is applicable to Bc meson decays to other charmonia and charmed mesons.

A potential large and persistent black carbon forcing over Northern Pacific inferred from satellite observations.

PubMed

Li, Zhongshu; Liu, Junfeng; Mauzerall, Denise L; Li, Xiaoyuan; Fan, Songmiao; Horowitz, Larry W; He, Cenlin; Yi, Kan; Tao, Shu

2017-03-07

Black carbon (BC) aerosol strongly absorbs solar radiation, which warms climate. However, accurate estimation of BC's climate effect is limited by the uncertainties of its spatiotemporal distribution, especially over remote oceanic areas. The HIAPER Pole-to-Pole Observation (HIPPO) program from 2009 to 2011 intercepted multiple snapshots of BC profiles over Pacific in various seasons, and revealed a 2 to 5 times overestimate of BC by current global models. In this study, we compared the measurements from aircraft campaigns and satellites, and found a robust association between BC concentrations and satellite-retrieved CO, tropospheric NO 2 , and aerosol optical depth (AOD) (R 2  > 0.8). This establishes a basis to construct a satellite-based column BC approximation (sBC*) over remote oceans. The inferred sBC* shows that Asian outflows in spring bring much more BC aerosols to the mid-Pacific than those occurring in other seasons. In addition, inter-annual variability of sBC* is seen over the Northern Pacific, with abundances varying consistently with the springtime Pacific/North American (PNA) index. Our sBC* dataset infers a widespread overestimation of BC loadings and BC Direct Radiative Forcing by current models over North Pacific, which further suggests that large uncertainties exist on aerosol-climate interactions over other remote oceanic areas beyond Pacific.

Primary carbonaceous aerosols and climate modeling: Classifications, global emission inventories, and observations

NASA Astrophysics Data System (ADS)

Sun, H.; Bond, T.

2004-12-01

Carbonaceous aerosols, including black carbon (BC) and organic carbon (OC), make up a large fraction of the atmospheric aerosols and affect the radiative balance of the earth either by directly scattering and absorbing solar radiation or through indirect influence on cloud optical properties and cloud lifetimes. The major sources of BC and OC emissions are from combustion processes, mainly.fossil-fuel burning, biofuels burning, and open biomass burning. OC is nearly always emitted with BC. Because different combustion practices contribute to the emission of BC and OC to the atmosphere, the magnitude and characteristics of carbonaceous aerosols vary between regions. Since OC mainly scatters light and BC absorbs it, it is possible that OC can oppose the warming effect of BC, so that the net climatic effect of carbonaceous aerosols is not known. There is presently disagreement on whether carbonaceous aerosols produce a net warming or cooling effect on climate. Some differences in model prediction may result from model differences, such as dynamics and treatment of cloud feedbacks. However, large differences also result from initial assumptions about the properties of BC and OC: optical properties, size distribution, and interaction with water. Although there are hundreds of different organic species in atmospheric aerosols, with widely varying properties, global climate models to date have treated organics as one ¡°compound.¡± In addition, emissions of OC are often derived by multiplying BC emissions by a constant factor, so that the balance between these different compounds is assumed. Addressing these critical model assumptions is a necessary step toward estimating the net climatic impact of carbonaceous aerosols, and different human activities. We aim to contribute to this effort by tabulating important climate-relevant properties of both emissions and ambient measurements. Since one single organic ¡°compound¡± is not sufficient to represent all the organics in aerosols, we propose a Climate-Relevant Optical & Structural Subgroups of OC (CROSS-OC) which is a classification for organic aerosols based on structural and optical properties. We provide broad classes aiming at global models instead of very detailed classifications, which are not amenable for use in global-scale models due to the calculation cost. Organic matter (OM) which includes the hydrogen and oxygen bound to this carbon is divided into classes with varied absorption and scattering capabilities. Because our inventory tabulates emissions from specific sources, we make use of data available from source characterization. We present a global emission inventory of primary carbonaceous aerosols that has been designed for global climate modeling purpose. The inventory is based on our CROSS-OC classification and considers emissions from fossil fuels, biofuels, and open biomass burning. Fuel type, combustion type, and emission controls, and their prevalence on a regional basis are combined to determine emission factors for all types of carbonaceous aerosols. We also categorize surface concentration observations for BC and OC by region, size (super vs. sub micron), measurement type, time (including season) and date. We parallel the data format suggested by the Global Atmosphere Watch aerosol database. Work underway includes providing information on the CROSS-OC divisions in ambient aerosol when measurements contain sufficient detail.

A three-dimensional sectional representation of aerosol mixing state for simulating optical properties and cloud condensation nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ching, Ping Pui; Zaveri, Rahul A.; Easter, Richard C.

2016-05-27

Light absorption by black carbon (BC) particles emitted from fossil fuel combustion depends on the how thickly they are coated with non-refractory species such as ammonium, sulfate, nitrate, organics, and water. The cloud condensation nuclei (CCN) activation property of a particle depends on its dry size and the hygroscopicities of all the individual species mixed together. It is therefore necessary to represent both size and mixing state of aerosols to reliably predict their climate-relevant properties in atmospheric models. Here we describe and evaluate a novel sectional framework in the Model for Simulating Aerosol Interactions and Chemistry, referred to as MOSAIC-mix,more » that represents the mixing state by resolving aerosol dry size (Ddry), BC dry mass fraction (wBC), and hygroscopicity (κ). Using ten idealized urban plume scenarios in which different types of aerosols evolve over 24 hours under a range of atmospherically relevant environmental conditions, we examine errors in CCN concentrations and optical properties with respect to a more explicit aerosol mixing state representation. We find that only a small number of wBC and κ bins are needed to achieve significant reductions in the errors, and propose a configuration consisting of 24 Ddry bins, 2 wBC bins, and 2 κ bins that gives 24-hour average errors of about 5% or less in CCN concentrations and optical properties, 3-4 times lower than those from size-only-resolved simulations. These results show that MOSAIC-mix is suitable for use in regional and global models to examine the effects of evolving aerosol mixing states on aerosol-radiation-cloud feedbacks.« less

Insights into the binding behavior of bovine serum albumin to black carbon nanoparticles and induced cytotoxicity

NASA Astrophysics Data System (ADS)

Wu, Hai; Chen, Miaomiao; Shang, Mengting; Li, Xiang; Mu, Kui; Fan, Suhua; Jiang, Shuanglin; Li, Wenyong

2018-07-01

Black carbon (BC) is a main component of particulate matter (PM2.5). Due to their small size (<100 nm), inhaled ultrafine BC nanoparticles may penetrate the lung alveoli, where they interact with surfactant proteins and lipids, causing more serious damage to human health. Here, BC was analyzed to investigate the binding mechanism of its interaction with protein and induction of cytotoxicity changes. The binding process and protein conformation between BC and a serum protein (bovine serum albumin, BSA) were monitored by using a fluorescence quenching technique and UV-vis absorption, Fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopies. The experimental results revealed that the fluorescence quenching of BSA induced by BC was a static quenching process and the hydrophobic force played the critical role in the interaction. The native conformation of BSA on the BC surface was slightly disturbed but obvious structural unfolding of the secondary structure did not occur. In the cytotoxicity study, BC nanoparticles with low concentrations exhibited strong toxicity towards BEAS-2B cells. However, the toxicity of BC nanoparticles could be mitigated by the presence of BSA. Therefore, proteins in biological fluids likely reduce the toxic effect of BC on human health. These findings delineated the binding mechanism and the toxicity between BC and the BSA-BC system, contributing to the understanding of the biological effects of BC exposure on human health in polluted atmospheres.

Ablation of SNX6 leads to defects in synaptic function of CA1 pyramidal neurons and spatial memory

PubMed Central

Niu, Yang; Dai, Zhonghua; Liu, Wenxue; Zhang, Cheng; Yang, Yanrui; Guo, Zhenzhen; Li, Xiaoyu; Xu, Chenchang; Huang, Xiahe; Wang, Yingchun; Shi, Yun S; Liu, Jia-Jia

2017-01-01

SNX6 is a ubiquitously expressed PX-BAR protein that plays important roles in retromer-mediated retrograde vesicular transport from endosomes. Here we report that CNS-specific Snx6 knockout mice exhibit deficits in spatial learning and memory, accompanied with loss of spines from distal dendrites of hippocampal CA1 pyramidal cells. SNX6 interacts with Homer1b/c, a postsynaptic scaffold protein crucial for the synaptic distribution of other postsynaptic density (PSD) proteins and structural integrity of dendritic spines. We show that SNX6 functions independently of retromer to regulate distribution of Homer1b/c in the dendritic shaft. We also find that Homer1b/c translocates from shaft to spines by protein diffusion, which does not require SNX6. Ablation of SNX6 causes reduced distribution of Homer1b/c in distal dendrites, decrease in surface levels of AMPAR and impaired AMPAR-mediated synaptic transmission. These findings reveal a physiological role of SNX6 in CNS excitatory neurons. DOI: http://dx.doi.org/10.7554/eLife.20991.001 PMID:28134614

Observation of an excited Bc(±) meson state with the ATLAS detector.

PubMed

Aad, G; Abbott, B; Abdallah, J; Abdel Khalek, S; Abdinov, O; Aben, R; Abi, B; Abolins, M; AbouZeid, O S; Abramowicz, H; Abreu, H; Abreu, R; Abulaiti, Y; Acharya, B S; Adamczyk, L; Adams, D L; Adelman, J; Adomeit, S; Adye, T; Agatonovic-Jovin, T; Aguilar-Saavedra, J A; Agustoni, M; Ahlen, S P; Ahmadov, F; Aielli, G; Akerstedt, H; Åkesson, T P A; Akimoto, G; Akimov, A V; Alberghi, G L; Albert, J; Albrand, S; Alconada Verzini, M J; Aleksa, M; Aleksandrov, I N; Alexa, C; Alexander, G; Alexandre, G; Alexopoulos, T; Alhroob, M; Alimonti, G; Alio, L; Alison, J; Allbrooke, B M M; Allison, L J; Allport, P P; Almond, J; Aloisio, A; Alonso, A; Alonso, F; Alpigiani, C; Altheimer, A; Alvarez Gonzalez, B; Alviggi, M G; Amako, K; Amaral Coutinho, Y; Amelung, C; Amidei, D; Amor Dos Santos, S P; Amorim, A; Amoroso, S; Amram, N; Amundsen, G; Anastopoulos, C; Ancu, L S; Andari, N; Andeen, T; Anders, C F; Anders, G; Anderson, K J; Andreazza, A; Andrei, V; Anduaga, X S; Angelidakis, S; Angelozzi, I; Anger, P; Angerami, A; Anghinolfi, F; Anisenkov, A V; Anjos, N; Annovi, A; Antonaki, A; Antonelli, M; Antonov, A; Antos, J; Anulli, F; Aoki, M; Aperio Bella, L; Apolle, R; Arabidze, G; Aracena, I; Arai, Y; Araque, J P; Arce, A T H; Arguin, J-F; Argyropoulos, S; Arik, M; Armbruster, A J; Arnaez, O; Arnal, V; Arnold, H; Arratia, M; Arslan, O; Artamonov, A; Artoni, G; Asai, S; Asbah, N; Ashkenazi, A; Åsman, B; Asquith, L; Assamagan, K; Astalos, R; Atkinson, M; Atlay, N B; Auerbach, B; Augsten, K; Aurousseau, M; Avolio, G; Azuelos, G; Azuma, Y; Baak, M A; Baas, A; Bacci, C; Bachacou, H; Bachas, K; Backes, M; Backhaus, M; Backus Mayes, J; Badescu, E; Bagiacchi, P; Bagnaia, P; Bai, Y; Bain, T; Baines, J T; Baker, O K; Balek, P; Balli, F; Banas, E; Banerjee, Sw; Bannoura, A A E; Bansal, V; Bansil, H S; Barak, L; Baranov, S P; Barberio, E L; Barberis, D; Barbero, M; Barillari, T; Barisonzi, M; Barklow, T; Barlow, N; Barnett, B M; Barnett, R M; Barnovska, Z; Baroncelli, A; Barone, G; Barr, A J; Barreiro, F; Barreiro Guimarães da Costa, J; Bartoldus, R; Barton, A E; Bartos, P; Bartsch, V; Bassalat, A; Basye, A; Bates, R L; Batkova, L; Batley, J R; Battaglia, M; Battistin, M; Bauer, F; Bawa, H S; Beau, T; Beauchemin, P H; Beccherle, R; Bechtle, P; Beck, H P; Becker, K; Becker, S; Beckingham, M; Becot, C; Beddall, A J; Beddall, A; Bedikian, S; Bednyakov, V A; Bee, C P; Beemster, L J; Beermann, T A; Begel, M; Behr, K; Belanger-Champagne, C; Bell, P J; Bell, W H; Bella, G; Bellagamba, L; Bellerive, A; Bellomo, M; Belotskiy, K; Beltramello, O; Benary, O; Benchekroun, D; Bendtz, K; Benekos, N; Benhammou, Y; Benhar Noccioli, E; Benitez Garcia, J A; Benjamin, D P; Bensinger, J R; Benslama, K; Bentvelsen, S; Berge, D; Bergeaas Kuutmann, E; Berger, N; Berghaus, F; Beringer, J; Bernard, C; Bernat, P; Bernius, C; Bernlochner, F U; Berry, T; Berta, P; Bertella, C; Bertoli, G; Bertolucci, F; Bertsche, D; Besana, M I; Besjes, G J; Bessidskaia, O; Bessner, M; Besson, N; Betancourt, C; Bethke, S; Bhimji, W; Bianchi, R M; Bianchini, L; Bianco, M; Biebel, O; Bieniek, S P; Bierwagen, K; Biesiada, J; Biglietti, M; Bilbao De Mendizabal, J; Bilokon, H; Bindi, M; Binet, S; Bingul, A; Bini, C; Black, C W; Black, J E; Black, K M; Blackburn, D; Blair, R E; Blanchard, J-B; Blazek, T; Bloch, I; Blocker, C; Blum, W; Blumenschein, U; Bobbink, G J; Bobrovnikov, V S; Bocchetta, S S; Bocci, A; Bock, C; Boddy, C R; Boehler, M; Boek, T T; Bogaerts, J A; Bogdanchikov, A G; Bogouch, A; Bohm, C; Bohm, J; Boisvert, V; Bold, T; Boldea, V; Boldyrev, A S; Bomben, M; Bona, M; Boonekamp, M; Borisov, A; Borissov, G; Borri, M; Borroni, S; Bortfeldt, J; Bortolotto, V; Bos, K; Boscherini, D; Bosman, M; Boterenbrood, H; Boudreau, J; Bouffard, J; Bouhova-Thacker, E V; Boumediene, D; Bourdarios, C; Bousson, N; Boutouil, S; Boveia, A; Boyd, J; Boyko, I R; Bracinik, J; Brandt, A; Brandt, G; Brandt, O; Bratzler, U; Brau, B; Brau, J E; Braun, H M; Brazzale, S F; Brelier, B; Brendlinger, K; Brennan, A J; Brenner, R; Bressler, S; Bristow, K; Bristow, T M; Britton, D; Brochu, F M; Brock, I; Brock, R; Bromberg, C; Bronner, J; Brooijmans, G; Brooks, T; Brooks, W K; Brosamer, J; Brost, E; Brown, J; Bruckman de Renstrom, P A; Bruncko, D; Bruneliere, R; Brunet, S; Bruni, A; Bruni, G; Bruschi, M; Bryngemark, L; Buanes, T; Buat, Q; Bucci, F; Buchholz, P; Buckingham, R M; Buckley, A G; Buda, S I; Budagov, I A; Buehrer, F; Bugge, L; Bugge, M K; Bulekov, O; Bundock, A C; Burckhart, H; Burdin, S; Burghgrave, B; Burke, S; Burmeister, I; Busato, E; Büscher, D; Büscher, V; Bussey, P; Buszello, C P; Butler, B; Butler, J M; Butt, A I; Buttar, C M; Butterworth, J M; Butti, P; Buttinger, W; Buzatu, A; Byszewski, M; Cabrera Urbán, S; Caforio, D; Cakir, O; Calafiura, P; Calandri, A; Calderini, G; Calfayan, P; Calkins, R; Caloba, L P; Calvet, D; Calvet, S; Camacho Toro, R; Camarda, S; Cameron, D; Caminada, L M; Caminal Armadans, R; Campana, S; Campanelli, M; Campoverde, A; Canale, V; Canepa, A; Cano Bret, M; Cantero, J; Cantrill, R; Cao, T; Capeans Garrido, M D M; Caprini, I; Caprini, M; Capua, M; Caputo, R; Cardarelli, R; Carli, T; Carlino, G; Carminati, L; Caron, S; Carquin, E; Carrillo-Montoya, G D; Carter, J R; Carvalho, J; Casadei, D; Casado, M P; Casolino, M; Castaneda-Miranda, E; Castelli, A; Castillo Gimenez, V; Castro, N F; Catastini, P; Catinaccio, A; Catmore, J R; Cattai, A; Cattani, G; Caughron, S; Cavaliere, V; Cavalli, D; Cavalli-Sforza, M; Cavasinni, V; Ceradini, F; Cerio, B; Cerny, K; Cerqueira, A S; Cerri, A; Cerrito, L; Cerutti, F; Cerv, M; Cervelli, A; Cetin, S A; Chafaq, A; Chakraborty, D; Chalupkova, I; Chang, P; Chapleau, B; Chapman, J D; Charfeddine, D; Charlton, D G; Chau, C C; Chavez Barajas, C A; Cheatham, S; Chegwidden, A; Chekanov, S; Chekulaev, S V; Chelkov, G A; Chelstowska, M A; Chen, C; Chen, H; Chen, K; Chen, L; Chen, S; Chen, X; Chen, Y; Cheng, H C; Cheng, Y; Cheplakov, A; Cherkaoui El Moursli, R; Chernyatin, V; Cheu, E; Chevalier, L; Chiarella, V; Chiefari, G; Childers, J T; Chilingarov, A; Chiodini, G; Chisholm, A S; Chislett, R T; Chitan, A; Chizhov, M V; Chouridou, S; Chow, B K B; Chromek-Burckhart, D; Chu, M L; Chudoba, J; Chwastowski, J J; Chytka, L; Ciapetti, G; Ciftci, A K; Ciftci, R; Cinca, D; Cindro, V; Ciocio, A; Cirkovic, P; Citron, Z H; Citterio, M; Ciubancan, M; Clark, A; Clark, P J; Clarke, R N; Cleland, W; Clemens, J C; Clement, C; Coadou, Y; Cobal, M; Coccaro, A; Cochran, J; Coffey, L; Cogan, J G; Coggeshall, J; Cole, B; Cole, S; Colijn, A P; Collot, J; Colombo, T; Colon, G; Compostella, G; Conde Muiño, P; Coniavitis, E; Conidi, M C; Connell, S H; Connelly, I A; Consonni, S M; Consorti, V; Constantinescu, S; Conta, C; Conti, G; Conventi, F; Cooke, M; Cooper, B D; Cooper-Sarkar, A M; Cooper-Smith, N J; Copic, K; Cornelissen, T; Corradi, M; Corriveau, F; Corso-Radu, A; Cortes-Gonzalez, A; Cortiana, G; Costa, G; Costa, M J; Costanzo, D; Côté, D; Cottin, G; Cowan, G; Cox, B E; Cranmer, K; Cree, G; Crépé-Renaudin, S; Crescioli, F; Cribbs, W A; Crispin Ortuzar, M; Cristinziani, M; Croft, V; Crosetti, G; Cuciuc, C-M; Cuhadar Donszelmann, T; Cummings, J; Curatolo, M; Cuthbert, C; Czirr, H; Czodrowski, P; Czyczula, Z; D'Auria, S; D'Onofrio, M; Da Cunha Sargedas De Sousa, M J; Da Via, C; Dabrowski, W; Dafinca, A; Dai, T; Dale, O; Dallaire, F; Dallapiccola, C; Dam, M; Daniells, A C; Dano Hoffmann, M; Dao, V; Darbo, G; Darmora, S; Dassoulas, J A; Dattagupta, A; Davey, W; David, C; Davidek, T; Davies, E; Davies, M; Davignon, O; Davison, A R; Davison, P; Davygora, Y; Dawe, E; Dawson, I; Daya-Ishmukhametova, R K; De, K; de Asmundis, R; De Castro, S; De Cecco, S; De Groot, N; de Jong, P; De la Torre, H; De Lorenzi, F; De Nooij, L; De Pedis, D; De Salvo, A; De Sanctis, U; De Santo, A; De Vivie De Regie, J B; Dearnaley, W J; Debbe, R; Debenedetti, C; Dechenaux, B; Dedovich, D V; Deigaard, I; Del Peso, J; Del Prete, T; Deliot, F; Delitzsch, C M; Deliyergiyev, M; Dell'Acqua, A; Dell'Asta, L; Dell'Orso, M; Della Pietra, M; della Volpe, D; Delmastro, M; Delsart, P A; Deluca, C; Demers, S; Demichev, M; Demilly, A; Denisov, S P; Derendarz, D; Derkaoui, J E; Derue, F; Dervan, P; Desch, K; Deterre, C; Deviveiros, P O; Dewhurst, A; Dhaliwal, S; Di Ciaccio, A; Di Ciaccio, L; Di Domenico, A; Di Donato, C; Di Girolamo, A; Di Girolamo, B; Di Mattia, A; Di Micco, B; Di Nardo, R; Di Simone, A; Di Sipio, R; Di Valentino, D; Dias, F A; Diaz, M A; Diehl, E B; Dietrich, J; Dietzsch, T A; Diglio, S; Dimitrievska, A; Dingfelder, J; Dionisi, C; Dita, P; Dita, S; Dittus, F; Djama, F; Djobava, T; do Vale, M A B; Do Valle Wemans, A; Doan, T K O; Dobos, D; Doglioni, C; Doherty, T; Dohmae, T; Dolejsi, J; Dolezal, Z; Dolgoshein, B A; Donadelli, M; Donati, S; Dondero, P; Donini, J; Dopke, J; Doria, A; Dova, M T; Doyle, A T; Dris, M; Dubbert, J; Dube, S; Dubreuil, E; Duchovni, E; Duckeck, G; Ducu, O A; Duda, D; Dudarev, A; Dudziak, F; Duflot, L; Duguid, L; Dührssen, M; Dunford, M; Duran Yildiz, H; Düren, M; Durglishvili, A; Dwuznik, M; Dyndal, M; Ebke, J; Edson, W; Edwards, N C; Ehrenfeld, W; Eifert, T; Eigen, G; Einsweiler, K; Ekelof, T; El Kacimi, M; Ellert, M; Elles, S; Ellinghaus, F; Ellis, N; Elmsheuser, J; Elsing, M; Emeliyanov, D; Enari, Y; Endner, O C; Endo, M; Engelmann, R; Erdmann, J; Ereditato, A; Eriksson, D; Ernis, G; Ernst, J; Ernst, M; Ernwein, J; Errede, D; Errede, S; Ertel, E; Escalier, M; Esch, H; Escobar, C; Esposito, B; Etienvre, A I; Etzion, E; Evans, H; Ezhilov, A; Fabbri, L; Facini, G; Fakhrutdinov, R M; Falciano, S; Falla, R J; Faltova, J; Fang, Y; Fanti, M; Farbin, A; Farilla, A; Farooque, T; Farrell, S; Farrington, S M; Farthouat, P; Fassi, F; Fassnacht, P; Fassouliotis, D; Favareto, A; Fayard, L; Federic, P; Fedin, O L; Fedorko, W; Fehling-Kaschek, M; Feigl, S; Feligioni, L; Feng, C; Feng, E J; Feng, H; Fenyuk, A B; Fernandez Perez, S; Ferrag, S; Ferrando, J; Ferrari, A; Ferrari, P; Ferrari, R; Ferreira de Lima, D E; Ferrer, A; Ferrere, D; Ferretti, C; Ferretto Parodi, A; Fiascaris, M; Fiedler, F; Filipčič, A; Filipuzzi, M; Filthaut, F; Fincke-Keeler, M; Finelli, K D; Fiolhais, M C N; Fiorini, L; Firan, A; Fischer, A; Fischer, J; Fisher, W C; Fitzgerald, E A; Flechl, M; Fleck, I; Fleischmann, P; Fleischmann, S; Fletcher, G T; Fletcher, G; Flick, T; Floderus, A; Flores Castillo, L R; Florez Bustos, A C; Flowerdew, M J; Formica, A; Forti, A; Fortin, D; Fournier, D; Fox, H; Fracchia, S; Francavilla, P; Franchini, M; Franchino, S; Francis, D; Franklin, M; Franz, S; Fraternali, M; French, S T; Friedrich, C; Friedrich, F; Froidevaux, D; Frost, J A; Fukunaga, C; Fullana Torregrosa, E; Fulsom, B G; Fuster, J; Gabaldon, C; Gabizon, O; Gabrielli, A; Gabrielli, A; Gadatsch, S; Gadomski, S; Gagliardi, G; Gagnon, P; Galea, C; Galhardo, B; Gallas, E J; Gallo, V; Gallop, B J; Gallus, P; Galster, G; Gan, K K; Gandrajula, R P; Gao, J; Gao, Y S; Garay Walls, F M; Garberson, F; García, C; García Navarro, J E; Garcia-Sciveres, M; Gardner, R W; Garelli, N; Garonne, V; Gatti, C; Gaudio, G; Gaur, B; Gauthier, L; Gauzzi, P; Gavrilenko, I L; Gay, C; Gaycken, G; Gazis, E N; Ge, P; Gecse, Z; Gee, C N P; Geerts, D A A; Geich-Gimbel, Ch; Gellerstedt, K; Gemme, C; Gemmell, A; Genest, M H; Gentile, S; George, M; George, S; Gerbaudo, D; Gershon, A; Ghazlane, H; Ghodbane, N; Giacobbe, B; Giagu, S; Giangiobbe, V; Giannetti, P; Gianotti, F; Gibbard, B; Gibson, S M; Gilchriese, M; Gillam, T P S; Gillberg, D; Gilles, G; Gingrich, D M; Giokaris, N; Giordani, M P; Giordano, R; Giorgi, F M; Giorgi, F M; Giraud, P F; Giugni, D; Giuliani, C; Giulini, M; Gjelsten, B K; Gkaitatzis, S; Gkialas, I; Gladilin, L K; Glasman, C; Glatzer, J; Glaysher, P C F; Glazov, A; Glonti, G L; Goblirsch-Kolb, M; Goddard, J R; Godfrey, J; Godlewski, J; Goeringer, C; Goldfarb, S; Golling, T; Golubkov, D; Gomes, A; Gomez Fajardo, L S; Gonçalo, R; Goncalves Pinto Firmino Da Costa, J; Gonella, L; González de la Hoz, S; Gonzalez Parra, G; Gonzalez-Sevilla, S; Goossens, L; Gorbounov, P A; Gordon, H A; Gorelov, I; Gorini, B; Gorini, E; Gorišek, A; Gornicki, E; Goshaw, A T; Gössling, C; Gostkin, M I; Gouighri, M; Goujdami, D; Goulette, M P; Goussiou, A G; Goy, C; Gozpinar, S; Grabas, H M X; Graber, L; Grabowska-Bold, I; Grafström, P; Grahn, K-J; Gramling, J; Gramstad, E; Grancagnolo, S; Grassi, V; Gratchev, V; Gray, H M; Graziani, E; Grebenyuk, O G; Greenwood, Z D; Gregersen, K; Gregor, I M; Grenier, P; Griffiths, J; Grillo, A A; Grimm, K; Grinstein, S; Gris, Ph; Grishkevich, Y V; Grivaz, J-F; Grohs, J P; Grohsjean, A; Gross, E; Grosse-Knetter, J; Grossi, G C; Groth-Jensen, J; Grout, Z J; Guan, L; Guescini, F; Guest, D; Gueta, O; Guicheney, C; Guido, E; Guillemin, T; Guindon, S; Gul, U; Gumpert, C; Gunther, J; Guo, J; Gupta, S; Gutierrez, P; Gutierrez Ortiz, N G; Gutschow, C; Guttman, N; Guyot, C; Gwenlan, C; Gwilliam, C B; Haas, A; Haber, C; Hadavand, H K; Haddad, N; Haefner, P; Hageböck, S; Hajduk, Z; Hakobyan, H; Haleem, M; Hall, D; Halladjian, G; Hamacher, K; Hamal, P; Hamano, K; Hamer, M; Hamilton, A; Hamilton, S; Hamnett, P G; Han, L; Hanagaki, K; Hanawa, K; Hance, M; Hanke, P; Hanna, R; Hansen, J B; Hansen, J D; Hansen, P H; Hara, K; Hard, A S; Harenberg, T; Hariri, F; Harkusha, S; Harper, D; Harrington, R D; Harris, O M; Harrison, P F; Hartjes, F; Hasegawa, S; Hasegawa, Y; Hasib, A; Hassani, S; Haug, S; Hauschild, M; Hauser, R; Havranek, M; Hawkes, C M; Hawkings, R J; Hawkins, A D; Hayashi, T; Hayden, D; Hays, C P; Hayward, H S; Haywood, S J; Head, S J; Heck, T; Hedberg, V; Heelan, L; Heim, S; Heim, T; Heinemann, B; Heinrich, L; Hejbal, J; Helary, L; Heller, C; Heller, M; Hellman, S; Hellmich, D; Helsens, C; Henderson, J; Henderson, R C W; Heng, Y; Hengler, C; Henrichs, A; Henriques Correia, A M; Henrot-Versille, S; Hensel, C; Herbert, G H; Hernández Jiménez, Y; Herrberg-Schubert, R; Herten, G; Hertenberger, R; Hervas, L; Hesketh, G G; Hessey, N P; Hickling, R; Higón-Rodriguez, E; Hill, E; Hill, J C; Hiller, K H; Hillert, S; Hillier, S J; Hinchliffe, I; Hines, E; Hirose, M; Hirschbuehl, D; Hobbs, J; Hod, N; Hodgkinson, M C; Hodgson, P; Hoecker, A; Hoeferkamp, M R; Hoffman, J; Hoffmann, D; Hofmann, J I; Hohlfeld, M; Holmes, T R; Hong, T M; Hooft van Huysduynen, L; Hostachy, J-Y; Hou, S; Hoummada, A; Howard, J; Howarth, J; Hrabovsky, M; Hristova, I; Hrivnac, J; Hryn'ova, T; Hsu, C; Hsu, P J; Hsu, S-C; Hu, D; Hu, X; Huang, Y; Hubacek, Z; Hubaut, F; Huegging, F; Huffman, T B; Hughes, E W; Hughes, G; Huhtinen, M; Hülsing, T A; Hurwitz, M; Huseynov, N; Huston, J; Huth, J; Iacobucci, G; Iakovidis, G; Ibragimov, I; Iconomidou-Fayard, L; Ideal, E; Iengo, P; Igonkina, O; Iizawa, T; Ikegami, Y; Ikematsu, K; Ikeno, M; Ilchenko, Y; Iliadis, D; Ilic, N; Inamaru, Y; Ince, T; Ioannou, P; Iodice, M; Iordanidou, K; Ippolito, V; Irles Quiles, A; Isaksson, C; Ishino, M; Ishitsuka, M; Ishmukhametov, R; Issever, C; Istin, S; Iturbe Ponce, J M; Iuppa, R; Ivarsson, J; Iwanski, W; Iwasaki, H; Izen, J M; Izzo, V; Jackson, B; Jackson, M; Jackson, P; Jaekel, M R; Jain, V; Jakobs, K; Jakobsen, S; Jakoubek, T; Jakubek, J; Jamin, D O; Jana, D K; Jansen, E; Jansen, H; Janssen, J; Janus, M; Jarlskog, G; Javadov, N; Javůrek, T; Jeanty, L; Jejelava, J; Jeng, G-Y; Jennens, D; Jenni, P; Jentzsch, J; Jeske, C; Jézéquel, S; Ji, H; Ji, W; Jia, J; Jiang, Y; Jimenez Belenguer, M; Jin, S; Jinaru, A; Jinnouchi, O; Joergensen, M D; Johansson, K E; Johansson, P; Johns, K A; Jon-And, K; Jones, G; Jones, R W L; Jones, T J; Jongmanns, J; Jorge, P M; Joshi, K D; Jovicevic, J; Ju, X; Jung, C A; Jungst, R M; Jussel, P; Juste Rozas, A; Kaci, M; Kaczmarska, A; Kado, M; Kagan, H; Kagan, M; Kajomovitz, E; Kalderon, C W; Kama, S; Kamenshchikov, A; Kanaya, N; Kaneda, M; Kaneti, S; Kantserov, V A; Kanzaki, J; Kaplan, B; Kapliy, A; Kar, D; Karakostas, K; Karastathis, N; Karnevskiy, M; Karpov, S N; Karpova, Z M; Karthik, K; Kartvelishvili, V; Karyukhin, A N; Kashif, L; Kasieczka, G; Kass, R D; Kastanas, A; Kataoka, Y; Katre, A; Katzy, J; Kaushik, V; Kawagoe, K; Kawamoto, T; Kawamura, G; Kazama, S; Kazanin, V F; Kazarinov, M Y; Keeler, R; Kehoe, R; Keil, M; Keller, J S; Kempster, J J; Keoshkerian, H; Kepka, O; Kerševan, B P; Kersten, S; Kessoku, K; Keung, J; Khalil-zada, F; Khandanyan, H; Khanov, A; Khodinov, A; Khomich, A; Khoo, T J; Khoriauli, G; Khoroshilov, A; Khovanskiy, V; Khramov, E; Khubua, J; Kim, H Y; Kim, H; Kim, S H; Kimura, N; Kind, O; King, B T; King, M; King, R S B; King, S B; Kirk, J; Kiryunin, A E; Kishimoto, T; Kisielewska, D; Kiss, F; Kittelmann, T; Kiuchi, K; Kladiva, E; Klein, M; Klein, U; Kleinknecht, K; Klimek, P; Klimentov, A; Klingenberg, R; Klinger, J A; Klioutchnikova, T; Klok, P F; Kluge, E-E; Kluit, P; Kluth, S; Kneringer, E; Knoops, E B F G; Knue, A; Kobayashi, D; Kobayashi, T; Kobel, M; Kocian, M; Kodys, P; Koevesarki, P; Koffas, T; Koffeman, E; Kogan, L A; Kohlmann, S; Kohout, Z; Kohriki, T; Koi, T; Kolanoski, H; Koletsou, I; Koll, J; Komar, A A; Komori, Y; Kondo, T; Kondrashova, N; Köneke, K; König, A C; König, S; Kono, T; Konoplich, R; Konstantinidis, N; Kopeliansky, R; Koperny, S; Köpke, L; Kopp, A K; Korcyl, K; Kordas, K; Korn, A; Korol, A A; Korolkov, I; Korolkova, E V; Korotkov, V A; Kortner, O; Kortner, S; Kostyukhin, V V; Kotov, V M; Kotwal, A; Kourkoumelis, C; Kouskoura, V; Koutsman, A; Kowalewski, R; Kowalski, T Z; Kozanecki, W; Kozhin, A S; Kral, V; Kramarenko, V A; Kramberger, G; Krasnopevtsev, D; Krasny, M W; Krasznahorkay, A; Kraus, J K; Kravchenko, A; Kreiss, S; Kretz, M; Kretzschmar, J; Kreutzfeldt, K; Krieger, P; Kroeninger, K; Kroha, H; Kroll, J; Kroseberg, J; Krstic, J; Kruchonak, U; Krüger, H; Kruker, T; Krumnack, N; Krumshteyn, Z V; Kruse, A; Kruse, M C; Kruskal, M; Kubota, T; Kuday, S; Kuehn, S; Kugel, A; Kuhl, A; Kuhl, T; Kukhtin, V; Kulchitsky, Y; Kuleshov, S; Kuna, M; Kunkle, J; Kupco, A; Kurashige, H; Kurochkin, Y A; Kurumida, R; Kus, V; Kuwertz, E S; Kuze, M; Kvita, J; La Rosa, A; La Rotonda, L; Lacasta, C; Lacava, F; Lacey, J; Lacker, H; Lacour, D; Lacuesta, V R; Ladygin, E; Lafaye, R; Laforge, B; Lagouri, T; Lai, S; Laier, H; Lambourne, L; Lammers, S; Lampen, C L; Lampl, W; Lançon, E; Landgraf, U; Landon, M P J; Lang, V S; Lankford, A J; Lanni, F; Lantzsch, K; Laplace, S; Lapoire, C; Laporte, J F; Lari, T; Lassnig, M; Laurelli, P; Lavrijsen, W; Law, A T; Laycock, P; Le, B T; Le Dortz, O; Le Guirriec, E; Le Menedeu, E; LeCompte, T; Ledroit-Guillon, F; Lee, C A; Lee, H; Lee, J S H; Lee, S C; Lee, L; Lefebvre, G; Lefebvre, M; Legger, F; Leggett, C; Lehan, A; Lehmacher, M; Lehmann Miotto, G; Lei, X; Leight, W A; Leisos, A; Leister, A G; Leite, M A L; Leitner, R; Lellouch, D; Lemmer, B; Leney, K J C; Lenz, T; Lenzen, G; Lenzi, B; Leone, R; Leone, S; Leonhardt, K; Leonidopoulos, C; Leontsinis, S; Leroy, C; Lester, C G; Lester, C M; Levchenko, M; Levêque, J; Levin, D; Levinson, L J; Levy, M; Lewis, A; Lewis, G H; Leyko, A M; Leyton, M; Li, B; Li, B; Li, H; Li, H L; Li, L; Li, L; Li, S; Li, Y; Liang, Z; Liao, H; Liberti, B; Lichard, P; Lie, K; Liebal, J; Liebig, W; Limbach, C; Limosani, A; Lin, S C; Lin, T H; Linde, F; Lindquist, B E; Linnemann, J T; Lipeles, E; Lipniacka, A; Lisovyi, M; Liss, T M; Lissauer, D; Lister, A; Litke, A M; Liu, B; Liu, D; Liu, J B; Liu, K; Liu, L; Liu, M; Liu, M; Liu, Y; Livan, M; Livermore, S S A; Lleres, A; Llorente Merino, J; Lloyd, S L; Lo Sterzo, F; Lobodzinska, E; Loch, P; Lockman, W S; Loddenkoetter, T; Loebinger, F K; Loevschall-Jensen, A E; Loginov, A; Loh, C W; Lohse, T; Lohwasser, K; Lokajicek, M; Lombardo, V P; Long, B A; Long, J D; Long, R E; Lopes, L; Lopez Mateos, D; Lopez Paredes, B; Lopez Paz, I; Lorenz, J; Lorenzo Martinez, N; Losada, M; Loscutoff, P; Lou, X; Lounis, A; Love, J; Love, P A; Lowe, A J; Lu, F; Lubatti, H J; Luci, C; Lucotte, A; Luehring, F; Lukas, W; Luminari, L; Lundberg, O; Lund-Jensen, B; Lungwitz, M; Lynn, D; Lysak, R; Lytken, E; Ma, H; Ma, L L; Maccarrone, G; Macchiolo, A; Machado Miguens, J; Macina, D; Madaffari, D; Madar, R; Maddocks, H J; Mader, W F; Madsen, A; Maeno, M; Maeno, T; Magradze, E; Mahboubi, K; Mahlstedt, J; Mahmoud, S; Maiani, C; Maidantchik, C; Maier, A A; Maio, A; Majewski, S; Makida, Y; Makovec, N; Mal, P; Malaescu, B; Malecki, Pa; Maleev, V P; Malek, F; Mallik, U; Malon, D; Malone, C; Maltezos, S; Malyshev, V M; Malyukov, S; Mamuzic, J; Mandelli, B; Mandelli, L; Mandić, I; Mandrysch, R; Maneira, J; Manfredini, A; Manhaes de Andrade Filho, L; Manjarres Ramos, J A; Mann, A; Manning, P M; Manousakis-Katsikakis, A; Mansoulie, B; Mantifel, R; Mapelli, L; March, L; Marchand, J F; Marchiori, G; Marcisovsky, M; Marino, C P; Marjanovic, M; Marques, C N; Marroquim, F; Marsden, S P; Marshall, Z; Marti, L F; Marti-Garcia, S; Martin, B; Martin, B; Martin, T A; Martin, V J; Martin dit Latour, B; Martinez, H; Martinez, M; Martin-Haugh, S; Martyniuk, A C; Marx, M; Marzano, F; Marzin, A; Masetti, L; Mashimo, T; Mashinistov, R; Masik, J; Maslennikov, A L; Massa, I; Massol, N; Mastrandrea, P; Mastroberardino, A; Masubuchi, T; Mättig, P; Mattmann, J; Maurer, J; Maxfield, S J; Maximov, D A; Mazini, R; Mazzaferro, L; Mc Goldrick, G; Mc Kee, S P; McCarn, A; McCarthy, R L; McCarthy, T G; McCubbin, N A; McFarlane, K W; Mcfayden, J A; Mchedlidze, G; McMahon, S J; McPherson, R A; Meade, A; Mechnich, J; Medinnis, M; Meehan, S; Mehlhase, S; Mehta, A; Meier, K; Meineck, C; Meirose, B; Melachrinos, C; Mellado Garcia, B R; Meloni, F; Mengarelli, A; Menke, S; Meoni, E; Mercurio, K M; Mergelmeyer, S; Meric, N; Mermod, P; Merola, L; Meroni, C; Merritt, F S; Merritt, H; Messina, A; Metcalfe, J; Mete, A S; Meyer, C; Meyer, C; Meyer, J-P; Meyer, J; Middleton, R P; Migas, S; Mijović, L; Mikenberg, G; Mikestikova, M; Mikuž, M; Milic, A; Miller, D W; Mills, C; Milov, A; Milstead, D A; Milstein, D; Minaenko, A A; Minashvili, I A; Mincer, A I; Mindur, B; Mineev, M; Ming, Y; Mir, L M; Mirabelli, G; Mitani, T; Mitrevski, J; Mitsou, V A; Mitsui, S; Miucci, A; Miyagawa, P S; Mjörnmark, J U; Moa, T; Mochizuki, K; Mohapatra, S; Mohr, W; Molander, S; Moles-Valls, R; Mönig, K; Monini, C; Monk, J; Monnier, E; Montejo Berlingen, J; Monticelli, F; Monzani, S; Moore, R W; Moraes, A; Morange, N; Moreno, D; Moreno Llácer, M; Morettini, P; Morgenstern, M; Morii, M; Moritz, S; Morley, A K; Mornacchi, G; Morris, J D; Morvaj, L; Moser, H G; Mosidze, M; Moss, J; Motohashi, K; Mount, R; Mountricha, E; Mouraviev, S V; Moyse, E J W; Muanza, S; Mudd, R D; Mueller, F; Mueller, J; Mueller, K; Mueller, T; Mueller, T; Muenstermann, D; Munwes, Y; Murillo Quijada, J A; Murray, W J; Musheghyan, H; Musto, E; Myagkov, A G; Myska, M; Nackenhorst, O; Nadal, J; Nagai, K; Nagai, R; Nagai, Y; Nagano, K; Nagarkar, A; Nagasaka, Y; Nagel, M; Nairz, A M; Nakahama, Y; Nakamura, K; Nakamura, T; Nakano, I; Namasivayam, H; Nanava, G; Narayan, R; Nattermann, T; Naumann, T; Navarro, G; Nayyar, R; Neal, H A; Nechaeva, P Yu; Neep, T J; Nef, P D; Negri, A; Negri, G; Negrini, M; Nektarijevic, S; Nelson, A; Nelson, T K; Nemecek, S; Nemethy, P; Nepomuceno, A A; Nessi, M; Neubauer, M S; Neumann, M; Neves, R M; Nevski, P; Newman, P R; Nguyen, D H; Nickerson, R B; Nicolaidou, R; Nicquevert, B; Nielsen, J; Nikiforou, N; Nikiforov, A; Nikolaenko, V; Nikolic-Audit, I; Nikolics, K; Nikolopoulos, K; Nilsson, P; Ninomiya, Y; Nisati, A; Nisius, R; Nobe, T; Nodulman, L; Nomachi, M; Nomidis, I; Norberg, S; Nordberg, M; Novgorodova, O; Nowak, S; Nozaki, M; Nozka, L; Ntekas, K; Nunes Hanninger, G; Nunnemann, T; Nurse, E; Nuti, F; O'Brien, B J; O'grady, F; O'Neil, D C; O'Shea, V; Oakham, F G; Oberlack, H; Obermann, T; Ocariz, J; Ochi, A; Ochoa, M I; Oda, S; Odaka, S; Ogren, H; Oh, A; Oh, S H; Ohm, C C; Ohman, H; Ohshima, T; Okamura, W; Okawa, H; Okumura, Y; Okuyama, T; Olariu, A; Olchevski, A G; Olivares Pino, S A; Oliveira Damazio, D; Oliver Garcia, E; Olszewski, A; Olszowska, J; Onofre, A; Onyisi, P U E; Oram, C J; Oreglia, M J; Oren, Y; Orestano, D; Orlando, N; Oropeza Barrera, C; Orr, R S; Osculati, B; Ospanov, R; Otero y Garzon, G; Otono, H; Ouchrif, M; Ouellette, E A; Ould-Saada, F; Ouraou, A; Oussoren, K P; Ouyang, Q; Ovcharova, A; Owen, M; Ozcan, V E; Ozturk, N; Pachal, K; Pacheco Pages, A; Padilla Aranda, C; Pagáčová, M; Pagan Griso, S; Paganis, E; Pahl, C; Paige, F; Pais, P; Pajchel, K; Palacino, G; Palestini, S; Palka, M; Pallin, D; Palma, A; Palmer, J D; Pan, Y B; Panagiotopoulou, E; Panduro Vazquez, J G; Pani, P; Panikashvili, N; Panitkin, S; Pantea, D; Paolozzi, L; Papadopoulou, Th D; Papageorgiou, K; Paramonov, A; Paredes Hernandez, D; Parker, M A; Parodi, F; Parsons, J A; Parzefall, U; Pasqualucci, E; Passaggio, S; Passeri, A; Pastore, F; Pastore, Fr; Pásztor, G; Pataraia, S; Patel, N D; Pater, J R; Patricelli, S; Pauly, T; Pearce, J; Pedersen, M; Pedraza Lopez, S; Pedro, R; Peleganchuk, S V; Pelikan, D; Peng, H; Penning, B; Penwell, J; Perepelitsa, D V; Perez Codina, E; Pérez García-Estañ, M T; Perez Reale, V; Perini, L; Pernegger, H; Perrino, R; Peschke, R; Peshekhonov, V D; Peters, K; Peters, R F Y; Petersen, B A; Petersen, T C; Petit, E; Petridis, A; Petridou, C; Petrolo, E; Petrucci, F; Pettersson, N E; Pezoa, R; Phillips, P W; Piacquadio, G; Pianori, E; Picazio, A; Piccaro, E; Piccinini, M; Piegaia, R; Pignotti, D T; Pilcher, J E; Pilkington, A D; Pina, J; Pinamonti, M; Pinder, A; Pinfold, J L; Pingel, A; Pinto, B; Pires, S; Pitt, M; Pizio, C; Plazak, L; Pleier, M-A; Pleskot, V; Plotnikova, E; Plucinski, P; Poddar, S; Podlyski, F; Poettgen, R; Poggioli, L; Pohl, D; Pohl, M; Polesello, G; Policicchio, A; Polifka, R; Polini, A; Pollard, C S; Polychronakos, V; Pommès, K; Pontecorvo, L; Pope, B G; Popeneciu, G A; Popovic, D S; Poppleton, A; Portell Bueso, X; Pospisil, S; Potamianos, K; Potrap, I N; Potter, C J; Potter, C T; Poulard, G; Poveda, J; Pozdnyakov, V; Pralavorio, P; Pranko, A; Prasad, S; Pravahan, R; Prell, S; Price, D; Price, J; Price, L E; Prieur, D; Primavera, M; Proissl, M; Prokofiev, K; Prokoshin, F; Protopapadaki, E; Protopopescu, S; Proudfoot, J; Przybycien, M; Przysiezniak, H; Ptacek, E; Puddu, D; Pueschel, E; Puldon, D; Purohit, M; Puzo, P; Qian, J; Qin, G; Qin, Y; Quadt, A; Quarrie, D R; Quayle, W B; Queitsch-Maitland, M; Quilty, D; Qureshi, A; Radeka, V; Radescu, V; Radhakrishnan, S K; Radloff, P; Rados, P; Ragusa, F; Rahal, G; Rajagopalan, S; Rammensee, M; Randle-Conde, A S; Rangel-Smith, C; Rao, K; Rauscher, F; Rave, T C; Ravenscroft, T; Raymond, M; Read, A L; Readioff, N P; Rebuzzi, D M; Redelbach, A; Redlinger, G; Reece, R; Reeves, K; Rehnisch, L; Reisin, H; Relich, M; Rembser, C; Ren, H; Ren, Z L; Renaud, A; Rescigno, M; Resconi, S; Rezanova, O L; Reznicek, P; Rezvani, R; Richter, R; Ridel, M; Rieck, P; Rieger, J; Rijssenbeek, M; Rimoldi, A; Rinaldi, L; Ritsch, E; Riu, I; Rizatdinova, F; Rizvi, E; Robertson, S H; Robichaud-Veronneau, A; Robinson, D; Robinson, J E M; Robson, A; Roda, C; Rodrigues, L; Roe, S; Røhne, O; Rolli, S; Romaniouk, A; Romano, M; Romero Adam, E; Rompotis, N; Roos, L; Ros, E; Rosati, S; Rosbach, K; Rose, M; Rosendahl, P L; Rosenthal, O; Rossetti, V; Rossi, E; Rossi, L P; Rosten, R; Rotaru, M; Roth, I; Rothberg, J; Rousseau, D; Royon, C R; Rozanov, A; Rozen, Y; Ruan, X; Rubbo, F; Rubinskiy, I; Rud, V I; Rudolph, C; Rudolph, M S; Rühr, F; Ruiz-Martinez, A; Rurikova, Z; Rusakovich, N A; Ruschke, A; Rutherfoord, J P; Ruthmann, N; Ryabov, Y F; Rybar, M; Rybkin, G; Ryder, N C; Saavedra, A F; Sacerdoti, S; Saddique, A; Sadeh, I; Sadrozinski, H F-W; Sadykov, R; Safai Tehrani, F; Sakamoto, H; Sakurai, Y; Salamanna, G; Salamon, A; Saleem, M; Salek, D; Sales De Bruin, P H; Salihagic, D; Salnikov, A; Salt, J; Salvachua Ferrando, B M; Salvatore, D; Salvatore, F; Salvucci, A; Salzburger, A; Sampsonidis, D; Sanchez, A; Sánchez, J; Sanchez Martinez, V; Sandaker, H; Sandbach, R L; Sander, H G; Sanders, M P; Sandhoff, M; Sandoval, T; Sandoval, C; Sandstroem, R; Sankey, D P C; Sansoni, A; Santoni, C; Santonico, R; Santos, H; Santoyo Castillo, I; Sapp, K; Sapronov, A; Saraiva, J G; Sarrazin, B; Sartisohn, G; Sasaki, O; Sasaki, Y; Sauvage, G; Sauvan, E; Savard, P; Savu, D O; Sawyer, C; Sawyer, L; Saxon, D H; Saxon, J; Sbarra, C; Sbrizzi, A; Scanlon, T; Scannicchio, D A; Scarcella, M; Scarfone, V; Schaarschmidt, J; Schacht, P; Schaefer, D; Schaefer, R; Schaepe, S; Schaetzel, S; Schäfer, U; Schaffer, A C; Schaile, D; Schamberger, R D; Scharf, V; Schegelsky, V A; Scheirich, D; Schernau, M; Scherzer, M I; Schiavi, C; Schieck, J; Schillo, C; Schioppa, M; Schlenker, S; Schmidt, E; Schmieden, K; Schmitt, C; Schmitt, S; Schneider, B; Schnellbach, Y J; Schnoor, U; Schoeffel, L; Schoening, A; Schoenrock, B D; Schorlemmer, A L S; Schott, M; Schouten, D; Schovancova, J; Schramm, S; Schreyer, M; Schroeder, C; Schuh, N; Schultens, M J; Schultz-Coulon, H-C; Schulz, H; Schumacher, M; Schumm, B A; Schune, Ph; Schwanenberger, C; Schwartzman, A; Schwegler, Ph; Schwemling, Ph; Schwienhorst, R; Schwindling, J; Schwindt, T; Schwoerer, M; Sciacca, F G; Scifo, E; Sciolla, G; Scott, W G; Scuri, F; Scutti, F; Searcy, J; Sedov, G; Sedykh, E; Seidel, S C; Seiden, A; Seifert, F; Seixas, J M; Sekhniaidze, G; Sekula, S J; Selbach, K E; Seliverstov, D M; Sellers, G; Semprini-Cesari, N; Serfon, C; Serin, L; Serkin, L; Serre, T; Seuster, R; Severini, H; Sfiligoj, T; Sforza, F; Sfyrla, A; Shabalina, E; Shamim, M; Shan, L Y; Shang, R; Shank, J T; Shapiro, M; Shatalov, P B; Shaw, K; Shehu, C Y; Sherwood, P; Shi, L; Shimizu, S; Shimmin, C O; Shimojima, M; Shiyakova, M; Shmeleva, A; Shochet, M J; Short, D; Shrestha, S; Shulga, E; Shupe, M A; Shushkevich, S; Sicho, P; Sidiropoulou, O; Sidorov, D; Sidoti, A; Siegert, F; Sijacki, Dj; Silva, J; Silver, Y; Silverstein, D; Silverstein, S B; Simak, V; Simard, O; Simic, Lj; Simion, S; Simioni, E; Simmons, B; Simoniello, R; Simonyan, M; Sinervo, P; Sinev, N B; Sipica, V; Siragusa, G; Sircar, A; Sisakyan, A N; Sivoklokov, S Yu; Sjölin, J; Sjursen, T B; Skottowe, H P; Skovpen, K Yu; Skubic, P; Slater, M; Slavicek, T; Sliwa, K; Smakhtin, V; Smart, B H; Smestad, L; Smirnov, S Yu; Smirnov, Y; Smirnova, L N; Smirnova, O; Smith, K M; Smizanska, M; Smolek, K; Snesarev, A A; Snidero, G; Snyder, S; Sobie, R; Socher, F; Soffer, A; Soh, D A; Solans, C A; Solar, M; Solc, J; Soldatov, E Yu; Soldevila, U; Solfaroli Camillocci, E; Solodkov, A A; Soloshenko, A; Solovyanov, O V; Solovyev, V; Sommer, P; Song, H Y; Soni, N; Sood, A; Sopczak, A; Sopko, B; Sopko, V; Sorin, V; Sosebee, M; Soualah, R; Soueid, P; Soukharev, A M; South, D; Spagnolo, S; Spanò, F; Spearman, W R; Spettel, F; Spighi, R; Spigo, G; Spiller, L A; Spousta, M; Spreitzer, T; Spurlock, B; St Denis, R D; Staerz, S; Stahlman, J; Stamen, R; Stanecka, E; Stanek, R W; Stanescu, C; Stanescu-Bellu, M; Stanitzki, M M; Stapnes, S; Starchenko, E A; Stark, J; Staroba, P; Starovoitov, P; Staszewski, R; Stavina, P; Steinberg, P; Stelzer, B; Stelzer, H J; Stelzer-Chilton, O; Stenzel, H; Stern, S; Stewart, G A; Stillings, J A; Stockton, M C; Stoebe, M; Stoicea, G; Stolte, P; Stonjek, S; Stradling, A R; Straessner, A; Stramaglia, M E; Strandberg, J; Strandberg, S; Strandlie, A; Strauss, E; Strauss, M; Strizenec, P; Ströhmer, R; Strom, D M; Stroynowski, R; Stucci, S A; Stugu, B; Styles, N A; Su, D; Su, J; Subramania, Hs; Subramaniam, R; Succurro, A; Sugaya, Y; Suhr, C; Suk, M; Sulin, V V; Sultansoy, S; Sumida, T; Sun, X; Sundermann, J E; Suruliz, K; Susinno, G; Sutton, M R; Suzuki, Y; Svatos, M; Swedish, S; Swiatlowski, M; Sykora, I; Sykora, T; Ta, D; Taccini, C; Tackmann, K; Taenzer, J; Taffard, A; Tafirout, R; Taiblum, N; Takahashi, Y; Takai, H; Takashima, R; Takeda, H; Takeshita, T; Takubo, Y; Talby, M; Talyshev, A A; Tam, J Y C; Tan, K G; Tanaka, J; Tanaka, R; Tanaka, S; Tanaka, S; Tanasijczuk, A J; Tannenwald, B B; Tannoury, N; Tapprogge, S; Tarem, S; Tarrade, F; Tartarelli, G F; Tas, P; Tasevsky, M; Tashiro, T; Tassi, E; Tavares Delgado, A; Tayalati, Y; Taylor, F E; Taylor, G N; Taylor, W; Teischinger, F A; Teixeira Dias Castanheira, M; Teixeira-Dias, P; Temming, K K; Ten Kate, H; Teng, P K; Teoh, J J; Terada, S; Terashi, K; Terron, J; Terzo, S; Testa, M; Teuscher, R J; Therhaag, J; Theveneaux-Pelzer, T; Thomas, J P; Thomas-Wilsker, J; Thompson, E N; Thompson, P D; Thompson, P D; Thompson, A S; Thomsen, L A; Thomson, E; Thomson, M; Thong, W M; Thun, R P; Tian, F; Tibbetts, M J; Tikhomirov, V O; Tikhonov, Yu A; Timoshenko, S; Tiouchichine, E; Tipton, P; Tisserant, S; Todorov, T; Todorova-Nova, S; Toggerson, B; Tojo, J; Tokár, S; Tokushuku, K; Tollefson, K; Tomlinson, L; Tomoto, M; Tompkins, L; Toms, K; Topilin, N D; Torrence, E; Torres, H; Torró Pastor, E; Toth, J; Touchard, F; Tovey, D R; Tran, H L; Trefzger, T; Tremblet, L; Tricoli, A; Trigger, I M; Trincaz-Duvoid, S; Tripiana, M F; Triplett, N; Trischuk, W; Trocmé, B; Troncon, C; Trottier-McDonald, M; Trovatelli, M; True, P; Trzebinski, M; Trzupek, A; Tsarouchas, C; Tseng, J C-L; Tsiareshka, P V; Tsionou, D; Tsipolitis, G; Tsirintanis, N; Tsiskaridze, S; Tsiskaridze, V; Tskhadadze, E G; Tsukerman, I I; Tsulaia, V; Tsuno, S; Tsybychev, D; Tudorache, A; Tudorache, V; Tuna, A N; Tupputi, S A; Turchikhin, S; Turecek, D; Turk Cakir, I; Turra, R; Tuts, P M; Tykhonov, A; Tylmad, M; Tyndel, M; Uchida, K; Ueda, I; Ueno, R; Ughetto, M; Ugland, M; Uhlenbrock, M; Ukegawa, F; Unal, G; Undrus, A; Unel, G; Ungaro, F C; Unno, Y; Unverdorben, C; Urbaniec, D; Urquijo, P; Usai, G; Usanova, A; Vacavant, L; Vacek, V; Vachon, B; Valencic, N; Valentinetti, S; Valero, A; Valery, L; Valkar, S; Valladolid Gallego, E; Vallecorsa, S; Valls Ferrer, J A; Van Den Wollenberg, W; Van Der Deijl, P C; van der Geer, R; van der Graaf, H; Van Der Leeuw, R; van der Ster, D; van Eldik, N; van Gemmeren, P; Van Nieuwkoop, J; van Vulpen, I; van Woerden, M C; Vanadia, M; Vandelli, W; Vanguri, R; Vaniachine, A; Vankov, P; Vannucci, F; Vardanyan, G; Vari, R; Varnes, E W; Varol, T; Varouchas, D; Vartapetian, A; Varvell, K E; Vazeille, F; Vazquez Schroeder, T; Veatch, J; Veloso, F; Veneziano, S; Ventura, A; Ventura, D; Venturi, M; Venturi, N; Venturini, A; Vercesi, V; Verducci, M; Verkerke, W; Vermeulen, J C; Vest, A; Vetterli, M C; Viazlo, O; Vichou, I; Vickey, T; Vickey Boeriu, O E; Viehhauser, G H A; Viel, S; Vigne, R; Villa, M; Villaplana Perez, M; Vilucchi, E; Vincter, M G; Vinogradov, V B; Virzi, J; Vivarelli, I; Vives Vaque, F; Vlachos, S; Vladoiu, D; Vlasak, M; Vogel, A; Vogel, M; Vokac, P; Volpi, G; Volpi, M; von der Schmitt, H; von Radziewski, H; von Toerne, E; Vorobel, V; Vorobev, K; Vos, M; Voss, R; Vossebeld, J H; Vranjes, N; Vranjes Milosavljevic, M; Vrba, V; Vreeswijk, M; Vu Anh, T; Vuillermet, R; Vukotic, I; Vykydal, Z; Wagner, P; Wagner, W; Wahlberg, H; Wahrmund, S; Wakabayashi, J; Walder, J; Walker, R; Walkowiak, W; Wall, R; Waller, P; Walsh, B; Wang, C; Wang, C; Wang, F; Wang, H; Wang, H; Wang, J; Wang, J; Wang, K; Wang, R; Wang, S M; Wang, T; Wang, X; Wanotayaroj, C; Warburton, A; Ward, C P; Wardrope, D R; Warsinsky, M; Washbrook, A; Wasicki, C; Watkins, P M; Watson, A T; Watson, I J; Watson, M F; Watts, G; Watts, S; Waugh, B M; Webb, S; Weber, M S; Weber, S W; Webster, J S; Weidberg, A R; Weigell, P; Weinert, B; Weingarten, J; Weiser, C; Weits, H; Wells, P S; Wenaus, T; Wendland, D; Weng, Z; Wengler, T; Wenig, S; Wermes, N; Werner, M; Werner, P; Wessels, M; Wetter, J; Whalen, K; White, A; White, M J; White, R; White, S; Whiteson, D; Wicke, D; Wickens, F J; Wiedenmann, W; Wielers, M; Wienemann, P; Wiglesworth, C; Wiik-Fuchs, L A M; Wijeratne, P A; Wildauer, A; Wildt, M A; Wilkens, H G; Will, J Z; Williams, H H; Williams, S; Willis, C; Willocq, S; Wilson, A; Wilson, J A; Wingerter-Seez, I; Winklmeier, F; Winter, B T; Wittgen, M; Wittig, T; Wittkowski, J; Wollstadt, S J; Wolter, M W; Wolters, H; Wosiek, B K; Wotschack, J; Woudstra, M J; Wozniak, K W; Wright, M; Wu, M; Wu, S L; Wu, X; Wu, Y; Wulf, E; Wyatt, T R; Wynne, B M; Xella, S; Xiao, M; Xu, D; Xu, L; Yabsley, B; Yacoob, S; Yamada, M; Yamaguchi, H; Yamaguchi, Y; Yamamoto, A; Yamamoto, K; Yamamoto, S; Yamamura, T; Yamanaka, T; Yamauchi, K; Yamazaki, Y; Yan, Z; Yang, H; Yang, H; Yang, U K; Yang, Y; Yanush, S; Yao, L; Yao, W-M; Yasu, Y; Yatsenko, E; Yau Wong, K H; Ye, J; Ye, S; Yen, A L; Yildirim, E; Yilmaz, M; Yoosoofmiya, R; Yorita, K; Yoshida, R; Yoshihara, K; Young, C; Young, C J S; Youssef, S; Yu, D R; Yu, J; Yu, J M; Yu, J; Yuan, L; Yurkewicz, A; Yusuff, I; Zabinski, B; Zaidan, R; Zaitsev, A M; Zaman, A; Zambito, S; Zanello, L; Zanzi, D; Zeitnitz, C; Zeman, M; Zemla, A; Zengel, K; Zenin, O; Ženiš, T; Zerwas, D; Zevi della Porta, G; Zhang, D; Zhang, F; Zhang, H; Zhang, J; Zhang, L; Zhang, X; Zhang, Z; Zhao, Z; Zhemchugov, A; Zhong, J; Zhou, B; Zhou, L; Zhou, N; Zhu, C G; Zhu, H; Zhu, J; Zhu, Y; Zhuang, X; Zhukov, K; Zibell, A; Zieminska, D; Zimine, N I; Zimmermann, C; Zimmermann, R; Zimmermann, S; Zimmermann, S; Zinonos, Z; Ziolkowski, M; Zobernig, G; Zoccoli, A; zur Nedden, M; Zurzolo, G; Zutshi, V; Zwalinski, L

2014-11-21

A search for excited states of the Bc(±) meson is performed using 4.9  fb(-1) of 7 TeV and 19.2  fb(-1) of 8 TeV pp collision data collected by the ATLAS experiment at the LHC. A new state is observed through its hadronic transition to the ground state, with the latter detected in the decay Bc(±)→J/ψπ(±). The state appears in the m(Bc(±)π(+)π(-))-m(Bc(±))-2m(π(±)) mass difference distribution with a significance of 5.2 standard deviations. The mass of the observed state is 6842±4±5  MeV, where the first error is statistical and the second is systematic. The mass and decay of this state are consistent with expectations for the second S-wave state of the Bc(±) meson, Bc(±)(2S).

Are emissions of black carbon from gasoline vehicles overestimated? Real-time, in situ measurement of black carbon emission factors.

PubMed

Wang, Yang; Xing, Zhenyu; Zhao, Shuhui; Zheng, Mei; Mu, Chao; Du, Ke

2016-03-15

Accurately quantifying black carbon (BC) emission factors (EFs) is a prerequisite for estimation of BC emission inventory. BC EFs determined by measuring BC at the roadside or chasing a vehicle on-road may introduce large uncertainty for low emission vehicles. In this study, BC concentrations were measured inside the tailpipe of gasoline vehicles with different engine sizes under different driving modes to determine the respective EFs. BC EFs ranged from 0.005-7.14 mg/kg-fuel under the speeds of 20-70 km/h, 0.05-28.95 mg/kg-fuel under the accelerations of 0.5-1.5m/s(2). Although the water vapor in the sampling stream could result in an average of 12% negative bias, the BC EFs are significantly lower than the published results obtained with roadside or chasing vehicle measurement. It is suggested to conduct measurement at the tailpipe of gasoline vehicles instead of in the atmosphere behind the vehicles to reduce the uncertainty from fluctuation in ambient BC concentration. Copyright © 2015 Elsevier B.V. All rights reserved.

A potential large and persistent black carbon forcing over Northern Pacific inferred from satellite observations

NASA Astrophysics Data System (ADS)

Li, Zhongshu; Liu, Junfeng; Mauzerall, Denise L.; Li, Xiaoyuan; Fan, Songmiao; Horowitz, Larry W.; He, Cenlin; Yi, Kan; Tao, Shu

2017-03-01

Black carbon (BC) aerosol strongly absorbs solar radiation, which warms climate. However, accurate estimation of BC’s climate effect is limited by the uncertainties of its spatiotemporal distribution, especially over remote oceanic areas. The HIAPER Pole-to-Pole Observation (HIPPO) program from 2009 to 2011 intercepted multiple snapshots of BC profiles over Pacific in various seasons, and revealed a 2 to 5 times overestimate of BC by current global models. In this study, we compared the measurements from aircraft campaigns and satellites, and found a robust association between BC concentrations and satellite-retrieved CO, tropospheric NO2, and aerosol optical depth (AOD) (R2 > 0.8). This establishes a basis to construct a satellite-based column BC approximation (sBC*) over remote oceans. The inferred sBC* shows that Asian outflows in spring bring much more BC aerosols to the mid-Pacific than those occurring in other seasons. In addition, inter-annual variability of sBC* is seen over the Northern Pacific, with abundances varying consistently with the springtime Pacific/North American (PNA) index. Our sBC* dataset infers a widespread overestimation of BC loadings and BC Direct Radiative Forcing by current models over North Pacific, which further suggests that large uncertainties exist on aerosol-climate interactions over other remote oceanic areas beyond Pacific.

Perturbations of the optical properties of mineral dust particles by mixing with black carbon: a numerical simulation study

DOE PAGES

Scarnato, B. V.; China, S.; Nielsen, K.; ...

2015-06-25

Field observations show that individual aerosol particles are a complex mixture of a wide variety of species, reflecting different sources and physico-chemical transformations. The impacts of individual aerosol morphology and mixing characteristics on the Earth system are not yet fully understood. Here we present a sensitivity study on climate-relevant aerosols optical properties to various approximations. Based on aerosol samples collected in various geographical locations, we have observationally constrained size, morphology and mixing, and accordingly simulated, using the discrete dipole approximation model (DDSCAT), optical properties of three aerosols types: (1) bare black carbon (BC) aggregates, (2) bare mineral dust, and (3)more » an internal mixture of a BC aggregate laying on top of a mineral dust particle, also referred to as polluted dust. DDSCAT predicts optical properties and their spectral dependence consistently with observations for all the studied cases. Predicted values of mass absorption, scattering and extinction coefficients (MAC, MSC, MEC) for bare BC show a weak dependence on the BC aggregate size, while the asymmetry parameter ( g) shows the opposite behavior. The simulated optical properties of bare mineral dust present a large variability depending on the modeled dust shape, confirming the limited range of applicability of spheroids over different types and size of mineral dust aerosols, in agreement with previous modeling studies. The polluted dust cases show a strong decrease in MAC values with the increase in dust particle size (for the same BC size) and an increase of the single scattering albedo (SSA). Furthermore, particles with a radius between 180 and 300 nm are characterized by a decrease in SSA values compared to bare dust, in agreement with field observations.This paper demonstrates that observationally constrained DDSCAT simulations allow one to better understand the variability of the measured aerosol optical properties in ambient air and to define benchmark biases due to different approximations in aerosol parametrization.« less

Optimized breeding strategies for multiple trait integration: I. Minimizing linkage drag in single event introgression.

PubMed

Peng, Ting; Sun, Xiaochun; Mumm, Rita H

2014-01-01

From a breeding standpoint, multiple trait integration (MTI) is a four-step process of converting an elite variety/hybrid for value-added traits (e.g. transgenic events) using backcross breeding, ultimately regaining the performance attributes of the target hybrid along with reliable expression of the value-added traits. In the light of the overarching goal of recovering equivalent performance in the finished conversion, this study focuses on the first step of MTI, single event introgression, exploring the feasibility of marker-aided backcross conversion of a target maize hybrid for 15 transgenic events, incorporating eight events into the female hybrid parent and seven into the male parent. Single event introgression is conducted in parallel streams to convert the recurrent parent (RP) for individual events, with the primary objective of minimizing residual non-recurrent parent (NRP) germplasm, especially in the chromosomal proximity to the event (i.e. linkage drag). In keeping with a defined lower limit of 96.66 % overall RP germplasm recovery (i.e. ≤120 cM NRP germplasm given a genome size of 1,788 cM), a breeding goal for each of the 15 single event conversions was developed: <8 cM of residual NRP germplasm across the genome with ~1 cM in the 20 cM region flanking the event. Using computer simulation, we aimed to identify optimal breeding strategies for single event introgression to achieve this breeding goal, measuring efficiency in terms of number of backcross generations required, marker data points needed, and total population size across generations. Various selection schemes classified as three-stage, modified two-stage, and combined selection conducted from BC1 through BC3, BC4, or BC5 were compared. The breeding goal was achieved with a selection scheme involving five generations of marker-aided backcrossing, with BC1 through BC3 selected for the event of interest and minimal linkage drag at population size of 600, and BC4 and BC5 selected for the event of interest and recovery of the RP germplasm across the genome at population size of 400, with selection intensity of 0.01 for all generations. In addition, strategies for choice of donor parent to facilitate conversion efficiency and quality were evaluated. Two essential criteria for choosing an optimal donor parent for a given RP were established: introgression history showing reduction of linkage drag to ~1 cM in the 20 cM region flanking the event and genetic similarity between the RP and potential donor parents. Computer simulation demonstrated that single event conversions with <8 cM residual NRP germplasm can be accomplished by BC5 with no genetic similarity, by BC4 with 30 % genetic similarity, and by BC3 with 86 % genetic similarity using previously converted RPs as event donors. This study indicates that MTI to produce a 'quality' 15-event-stacked hybrid conversion is achievable. Furthermore, it lays the groundwork for a comprehensive approach to MTI by outlining a pathway to produce appropriate starting materials with which to proceed with event pyramiding and trait fixation before version testing.

Rheological performance of bacterial cellulose based nonmineralized and mineralized hydrogel scaffolds

NASA Astrophysics Data System (ADS)

Basu, Probal; Saha, Nabanita; Bandyopadhyay, Smarak; Saha, Petr

2017-05-01

Bacterial cellulose (BC) based hydrogels (BC-PVP and BC-CMC) are modified with β-tri-calcium phosphate (β-TCP) and hydroxyapatite (HA) to improve the structural and functional properties of the existing hydrogel scaffolds. The modified hydrogels are then biomineralized with CaCO3 following liquid diffusion technique, where salt solutions of Na2CO3 (5.25 g/100 mL) and CaCl2 (7.35 g/100 mL) were involved. The BC-PVP and BC-CMC are being compared with the non-mineralized (BC-PVP-β-TCP/HA and BC-CMC-β-TCP/HA) and biomineralized (BC-PVP-β-TCP/HA-CaCO3 and BC-CMC-β-TCP/HA-CaCO3) hydrogels on the basis of their structural and rheological properties. The Fourier Transform Infrared (FTIR) spectral analysis demonstrated the presence of BC, CMC, PVP, β-TCP, HA in the non-mineralized and BC, CMC, PVP, β-TCP, HA and CaCO3 in the biomineralized samples. Interestingly, the morphological property of non-mineralized and biomineralized, hydrogels are different than that of BC-PVP and BC-CMC based novel biomaterials. The Scanning Electron Microscopic (SEM) images of the before mentioned samples reveal the denser structures than BC-PVP and BC-CMC, which exhibits the changes in their pore sizes. Concerning rheological analysis point of view, all the non-mineralized and biomineralized hydrogel scaffolds have shown significant elastic property. Additionally, the complex viscosity (η*) values have also found in decreasing order with the increase of angular frequency (ω) 0.1 rad.sec-1 to 100 rad.sec-1. All these BC based hydrogel scaffolds are elastic in nature, can be recommended for their application as an implant for bone tissue engineering.

Phylodynamic Analysis Revealed That Epidemic of CRF07_BC Strain in Men Who Have Sex with Men Drove Its Second Spreading Wave in China.

PubMed

Zhang, Min; Jia, Dijing; Li, Hanping; Gui, Tao; Jia, Lei; Wang, Xiaolin; Li, Tianyi; Liu, Yongjian; Bao, Zuoyi; Liu, Siyang; Zhuang, Daomin; Li, Jingyun; Li, Lin

2017-10-01

CRF07_BC was originally formed in Yunnan province of China in 1980s and spread quickly in injecting drug users (IDUs). In recent years, it has been introduced into men who have sex with men (MSM) and become the most dominant strain in China. In this study, we performed a comprehensively phylodynamic analysis of CRF07_BC sequences from China. All CRF07_BC sequences identified in China were retrieved from database. More sequences obtained in our laboratory were added to make the dataset more representative. A maximum-likelihood (ML) tree was constructed with PhyML3.0. Maximum clade credibility (MCC) tree and effective population size were predicted by using Markov Chains Monte Carlo sampling method with Beast software. A total of 610 CRF07_BC sequences coving 1,473 bp of the gag gene (from 817 to 2,289 according to HXB2 calculator) were included into the dataset. Three epidemic clusters were identified; two clusters comprised sequences from IDUs, while one cluster mainly contained sequences from MSMs. The time of the most recent common ancestor of clusters that composed of sequences from MSMs was estimated to be in 2000. Two rapid spreading waves of effective population size of CRF07_BC infections were identified in the skyline plot. The second wave coincided with the expanding of MSM cluster. The results indicated that the control of CRF07_BC infections in MSMs would help to decrease its epidemic in China.

Emissions from prescribed burning of agricultural fields in the Pacific Northwest

NASA Astrophysics Data System (ADS)

Holder, A. L.; Gullett, B. K.; Urbanski, S. P.; Elleman, R.; O'Neill, S.; Tabor, D.; Mitchell, W.; Baker, K. R.

2017-10-01

Prescribed burns of winter wheat stubble and Kentucky bluegrass fields in northern Idaho and eastern Washington states (U.S.A.) were sampled using ground-, aerostat-, airplane-, and laboratory-based measurement platforms to determine emission factors, compare methods, and provide a current and comprehensive set of emissions data for air quality models, climate models, and emission inventories. Batch measurements of PM2.5, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated dibenzodioxins/dibenzofurans (PCDDs/PCDFs), and continuous measurements of black carbon (BC), particle mass by size, CO, CO2, CH4, and aerosol characteristics were taken at ground level, on an aerostat-lofted instrument package, and from an airplane. Biomass samples gathered from the field were burned in a laboratory combustion facility for comparison with these ground and aerial field measurements. Emission factors for PM2.5, organic carbon (OC), CH4, and CO measured in the field study platforms were typically higher than those measured in the laboratory combustion facility. Field data for Kentucky bluegrass suggest that biomass residue loading is directly proportional to the PM2.5 emission factor; no such relationship was found with the limited wheat data. CO2 and BC emissions were higher in laboratory burn tests than in the field, reflecting greater carbon oxidation and flaming combustion conditions. These distinctions between field and laboratory results can be explained by measurements of the modified combustion efficiency (MCE). Higher MCEs were recorded in the laboratory burns than from the airplane platform. These MCE/emission factor trends are supported by 1-2 min grab samples from the ground and aerostat platforms. Emission factors measured here are similar to other studies measuring comparable fuels, pollutants, and combustion conditions. The size distribution of refractory BC (rBC) was single modal with a log-normal shape, which was consistent among fuel types when normalized by total rBC mass. The field and laboratory measurements of the Angstrom exponent (α) and single scattering albedo (ω) exhibit a strong decreasing trend with increasing MCEs in the range of 0.9-0.99. Field measurements of α and ω were consistently higher than laboratory burns, which is likely due to less complete combustion. When VOC emissions are compared with MCE, the results are consistent for both fuel types: emission factors increase as MCE decreases.

Methane, Black Carbon, and Ethane Emissions from Natural Gas Flares in the Bakken Shale, North Dakota.

PubMed

Gvakharia, Alexander; Kort, Eric A; Brandt, Adam; Peischl, Jeff; Ryerson, Thomas B; Schwarz, Joshua P; Smith, Mackenzie L; Sweeney, Colm

2017-05-02

Incomplete combustion during flaring can lead to production of black carbon (BC) and loss of methane and other pollutants to the atmosphere, impacting climate and air quality. However, few studies have measured flare efficiency in a real-world setting. We use airborne data of plume samples from 37 unique flares in the Bakken region of North Dakota in May 2014 to calculate emission factors for BC, methane, ethane, and combustion efficiency for methane and ethane. We find no clear relationship between emission factors and aircraft-level wind speed or between methane and BC emission factors. Observed median combustion efficiencies for methane and ethane are close to expected values for typical flares according to the US EPA (98%). However, we find that the efficiency distribution is skewed, exhibiting log-normal behavior. This suggests incomplete combustion from flares contributes almost 1/5 of the total field emissions of methane and ethane measured in the Bakken shale, more than double the expected value if 98% efficiency was representative. BC emission factors also have a skewed distribution, but we find lower emission values than previous studies. The direct observation for the first time of a heavy-tail emissions distribution from flares suggests the need to consider skewed distributions when assessing flare impacts globally.

Discrete size optimization of steel trusses using a refined big bang-big crunch algorithm

NASA Astrophysics Data System (ADS)

Hasançebi, O.; Kazemzadeh Azad, S.

2014-01-01

This article presents a methodology that provides a method for design optimization of steel truss structures based on a refined big bang-big crunch (BB-BC) algorithm. It is shown that a standard formulation of the BB-BC algorithm occasionally falls short of producing acceptable solutions to problems from discrete size optimum design of steel trusses. A reformulation of the algorithm is proposed and implemented for design optimization of various discrete truss structures according to American Institute of Steel Construction Allowable Stress Design (AISC-ASD) specifications. Furthermore, the performance of the proposed BB-BC algorithm is compared to its standard version as well as other well-known metaheuristic techniques. The numerical results confirm the efficiency of the proposed algorithm in practical design optimization of truss structures.

More than just needles: An evidence-informed approach to enhancing harm reduction supply distribution in British Columbia

PubMed Central

Buxton, Jane A; Preston, Emma C; Mak, Sunny; Harvard, Stephanie; Barley, Jenny

2008-01-01

Background The BC Harm Reduction Strategies and Services (HRSS) policy states that each health authority (HA) and their community partners will provide a full range of harm reduction (HR) services to their jurisdictions and these HR products should be available to all who need them regardless of where they live and choice of drug. Preliminary analysis revealed wide variations between and within HAs. Methods The objective of this study is to analyze distribution of HR products by site using Geographic Information Systems (GIS) and to investigate the range, adequacy and methods of HR product distribution using qualitative interviews. The BC Centre for Disease Control pharmacy database tracks HR supplies distributed to health units and community agencies. Additionally, eleven face-to-face interviews were conducted in eight mainland BC communities using an open-ended questionnaire. Results There is evidence in BC that HR supplies are not equally available throughout the province. There are variations within jurisdictions in how HR supplies are distributed, adequacy of current HR products, collection of used needles, alternative uses of supplies and community attitudes towards HR. GIS illustrates where HR supplies are ordered but with secondary distribution, true reach and availability of supplies cannot be determined. Conclusion Currently, a consultant is employed to develop a 'best practice' document; relevant health files, standard training and protocols within HAs are also being developed. There is a need to enhance the profile and availability of culturally appropriate HR services for Aboriginal populations. Distribution of crackpipe mouthpieces is being investigated. PMID:19108726

In Vitro and In Vivo Characterization of Drug Nanoparticles Prepared Using PureNano™ Continuous Crystallizer to Improve the Bioavailability of Poorly Water Soluble Drugs.

PubMed

Tahara, Kohei; Nishikawa, Masahiro; Matsui, Ko; Hisazumi, Koji; Onodera, Risako; Tozuka, Yuichi; Takeuchi, Hirofumi

2016-09-01

The aim of this study was to enhance the dissolution and oral absorption of poorly water-soluble active pharmaceutical ingredients (APIs) using nanoparticle suspensions prepared with a PureNano™ continuous crystallizer (PCC). Nanoparticle suspensions were prepared with a PCC, which is based on microfluidics reaction technology and solvent-antisolvent crystallization. Phenytoin, bezafibrate, flurbiprofen, and miconazole were used as model APIs. These APIs were dissolved in ethanol and precipitated by the addition of water and polyvinyl alcohol. Batch crystallization (BC) using a beaker was also performed to prepare the suspensions. Both PCC and BC formulations were freeze-dried before being characterized in vitro and in vivo. The particle sizes of the nanoparticle suspensions prepared with the PCC were smaller than those prepared by BC. The dissolution rate of each API in vitro significantly increased after crystallization. Reducing the particle size of either the BC or PCC formulation led to increased API flux across Caco-2 cell monolayers. PCC preparations showed higher plasma concentrations after oral administration, demonstrating the advantages of a fast dissolution rate and increased interaction with the gastrointestinal tract owing to the smaller particle size. PCC can continuously produce nanoparticle APIs and is an efficient approach for improving their oral bioavailability.

Insights into the binding behavior of bovine serum albumin to black carbon nanoparticles and induced cytotoxicity.

PubMed

Wu, Hai; Chen, Miaomiao; Shang, Mengting; Li, Xiang; Mu, Kui; Fan, Suhua; Jiang, Shuanglin; Li, Wenyong

2018-07-05

Black carbon (BC) is a main component of particulate matter (PM 2.5 ). Due to their small size (<100nm), inhaled ultrafine BC nanoparticles may penetrate the lung alveoli, where they interact with surfactant proteins and lipids, causing more serious damage to human health. Here, BC was analyzed to investigate the binding mechanism of its interaction with protein and induction of cytotoxicity changes. The binding process and protein conformation between BC and a serum protein (bovine serum albumin, BSA) were monitored by using a fluorescence quenching technique and UV-vis absorption, Fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopies. The experimental results revealed that the fluorescence quenching of BSA induced by BC was a static quenching process and the hydrophobic force played the critical role in the interaction. The native conformation of BSA on the BC surface was slightly disturbed but obvious structural unfolding of the secondary structure did not occur. In the cytotoxicity study, BC nanoparticles with low concentrations exhibited strong toxicity towards BEAS-2B cells. However, the toxicity of BC nanoparticles could be mitigated by the presence of BSA. Therefore, proteins in biological fluids likely reduce the toxic effect of BC on human health. These findings delineated the binding mechanism and the toxicity between BC and the BSA-BC system, contributing to the understanding of the biological effects of BC exposure on human health in polluted atmospheres. Copyright © 2018 Elsevier B.V. All rights reserved.

Distribution and relative abundance of humpback whales in relation to environmental variables in coastal British Columbia and adjacent waters

NASA Astrophysics Data System (ADS)

Dalla Rosa, Luciano; Ford, John K. B.; Trites, Andrew W.

2012-03-01

Humpback whales are common in feeding areas off British Columbia (BC) from spring to fall, and are widely distributed along the coast. Climate change and the increase in population size of North Pacific humpback whales may lead to increased anthropogenic impact and require a better understanding of species-habitat relationships. We investigated the distribution and relative abundance of humpback whales in relation to environmental variables and processes in BC waters using GIS and generalized additive models (GAMs). Six non-systematic cetacean surveys were conducted between 2004 and 2006. Whale encounter rates and environmental variables (oceanographic and remote sensing data) were recorded along transects divided into 4 km segments. A combined 3-year model and individual year models (two surveys each) were fitted with the mgcv R package. Model selection was based primarily on GCV scores. The explained deviance of our models ranged from 39% for the 3-year model to 76% for the 2004 model. Humpback whales were strongly associated with latitude and bathymetric features, including depth, slope and distance to the 100-m isobath. Distance to sea-surface-temperature fronts and salinity (climatology) were also constantly selected by the models. The shapes of smooth functions estimated for variables based on chlorophyll concentration or net primary productivity with different temporal resolutions and time lags were not consistent, even though higher numbers of whales seemed to be associated with higher primary productivity for some models. These and other selected explanatory variables may reflect areas of higher biological productivity that favor top predators. Our study confirms the presence of at least three important regions for humpback whales along the BC coast: south Dixon Entrance, middle and southwestern Hecate Strait and the area between La Perouse Bank and the southern edge of Juan de Fuca Canyon.

Stabilization of nanoscale zero-valent iron (nZVI) with modified biochar for Cr(VI) removal from aqueous solution.

PubMed

Dong, Haoran; Deng, Junmin; Xie, Yankai; Zhang, Cong; Jiang, Zhao; Cheng, Yujun; Hou, Kunjie; Zeng, Guangming

2017-06-15

Three types of modified biochar (BC) were produced respectively with acid (HCl) treatment (HCl-BC), base (KOH) treatment (KOH-BC) and oxidation (H 2 O 2 ) treatment (H 2 O 2 -BC) of raw biochar. Both the raw biochar and modified biochars supported zero valent iron nanopartilces (nZVI) (i.e. nZVI@BC, nZVI@HCl-BC, nZVI@KOH-BC and nZVI@H 2 O 2 -BC) were synthesized and their capacities for Cr(VI) removal were compared. The results showed that the nZVI@HCl-BC exhibited the best performance and the underlying mechanisms were discussed. The surface elemental distribution maps of the nZVI@HCl-BC after reaction with Cr(VI) showed that Fe, Cr and O elements were deposited on the surface of HCl-BC evenly, indicating that the formed Cr(III)/Fe(III) could settle on the surface of HCl-BC uniformly rather than coated only on the nZVI surface. This reveals that the supporter HCl-BC could also play a role in alleviating the passivation of nZVI. Besides, the effects of mass ratio (nZVI/HCl-BC), pH, and initial Cr(VI) concentration on Cr(VI) removal were examined. At lower mass of HCl-BC, nZVI aggregation cannot be fully inhibited on the surface of HCl-BC, whereas excessive biochar can block the active sites of nZVI. Additionally, it was found that Cr(VI) removal by nZVI@HCl-BC was dependent on both pH and initial Cr(VI) concentration. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Particle Filters and Accelerated Engine Replacement on Heavy-Duty Diesel Vehicle Emissions of Black Carbon, Nitrogen Oxides, and Ultrafine Particles

NASA Astrophysics Data System (ADS)

Kirchstetter, T.; Preble, C.; Dallmann, T. R.; DeMartini, S. J.; Tang, N. W.; Kreisberg, N. M.; Hering, S. V.; Harley, R. A.

2013-12-01

Diesel particle filters have become widely used in the United States since the introduction in 2007 of a more stringent exhaust particulate matter emission standard for new heavy-duty diesel vehicle engines. California has instituted additional regulations requiring retrofit or replacement of older in-use engines to accelerate emission reductions and air quality improvements. This presentation summarizes pollutant emission changes measured over several field campaigns at the Port of Oakland in the San Francisco Bay Area associated with diesel particulate filter use and accelerated modernization of the heavy-duty truck fleet. Pollutants in the exhaust plumes of hundreds of heavy-duty trucks en route to the Port were measured in 2009, 2010, 2011, and 2013. Ultrafine particle number, black carbon (BC), nitrogen oxides (NOx), and nitrogen dioxide (NO2) concentrations were measured at a frequency ≤ 1 Hz and normalized to measured carbon dioxide concentrations to quantify fuel-based emission factors (grams of pollutant emitted per kilogram of diesel consumed). The size distribution of particles in truck exhaust plumes was also measured at 1 Hz. In the two most recent campaigns, emissions were linked on a truck-by-truck basis to installed emission control equipment via the matching of transcribed license plates to a Port truck database. Accelerated replacement of older engines with newer engines and retrofit of trucks with diesel particle filters reduced fleet-average emissions of BC and NOx. Preliminary results from the two most recent field campaigns indicate that trucks without diesel particle filters emit 4 times more BC than filter-equipped trucks. Diesel particle filters increase emissions of NO2, however, and filter-equipped trucks have NO2/NOx ratios that are 4 to 7 times greater than trucks without filters. Preliminary findings related to particle size distribution indicate that (a) most trucks emitted particles characterized by a single mode of approximately 100 nm in diameter and (b) new trucks originally equipped with diesel particle filters were 5 to 6 times more likely than filter-retrofitted trucks and trucks without filters to emit particles characterized by a single mode in the range of 10 to 30 nm in diameter.

Aerosol physical and chemical properties retrieved from ground-based remote sensing measurements during heavy haze days in Beijing winter

NASA Astrophysics Data System (ADS)

Li, Z. Q.; Gu, X.; Wang, L.; Li, D.; Li, K.; Dubovik, O.; Schuster, G.; Goloub, P.; Zhang, Y.; Li, L.; Xie, Y.; Ma, Y.; Xu, H.

2013-02-01

With the development of economy in the past thirty years, many large cities in the eastern and southwestern China are experiencing increased haze events and atmospheric pollution, causing significant impacts on the regional environment and even climate. However, knowledge on the aerosol physical and chemical properties in heavy haze conditions is still insufficient. In this study, two winter heavy haze events in Beijing occurred in 2011 and 2012 were selected and investigated by using the ground-based remote sensing measurements. We used CIMEL CE318 sun-sky radiometer to derive haze aerosol optical, physical and chemical properties, including aerosol optical depth (AOD), size distribution, complex refractive indices and fractions of chemical components like black carbon (BC), brown carbon (BrC), mineral dust (DU), ammonium sulfate-like (AS) components and aerosol water content (AW). The retrieval results from a total of five haze days showed that the aerosol loading and properties during the two winter haze events were relatively stable. Therefore, a parameterized heavy haze characterization was drawn to present a research case for future studies. The averaged AOD is 3.2 at 440 nm and Ångström exponent is 1.3 from 440-870 nm. The coarse particles occupied a considerable fraction of the bimodal size distribution in winter haze events, with the mean particle radius of 0.21 and 2.9 μm for the fine and coarse mode respectively. The real part of the refractive indices exhibited a relatively flat spectral behavior with an average value of 1.48 from 440 to 1020 nm. The imaginary part showed obviously spectral variation with the value at 440 nm (about 0.013) higher than other three wavelengths (e.g. about 0.008 at 675 nm). The chemical composition retrieval results showed that BC, BrC, DU, AS and AW occupied 1%, 2%, 49%, 15% and 33% respectively on average for the investigated haze events. The comparison of these remote sensing results with in situ BC and PM2.5 measurements were also presented in the paper.

A potential large and persistent black carbon forcing over Northern Pacific inferred from satellite observations

PubMed Central

Li, Zhongshu; Liu, Junfeng; Mauzerall, Denise L.; Li, Xiaoyuan; Fan, Songmiao; Horowitz, Larry W.; He, Cenlin; Yi, Kan; Tao, Shu

2017-01-01

Black carbon (BC) aerosol strongly absorbs solar radiation, which warms climate. However, accurate estimation of BC’s climate effect is limited by the uncertainties of its spatiotemporal distribution, especially over remote oceanic areas. The HIAPER Pole-to-Pole Observation (HIPPO) program from 2009 to 2011 intercepted multiple snapshots of BC profiles over Pacific in various seasons, and revealed a 2 to 5 times overestimate of BC by current global models. In this study, we compared the measurements from aircraft campaigns and satellites, and found a robust association between BC concentrations and satellite-retrieved CO, tropospheric NO2, and aerosol optical depth (AOD) (R2 > 0.8). This establishes a basis to construct a satellite-based column BC approximation (sBC*) over remote oceans. The inferred sBC* shows that Asian outflows in spring bring much more BC aerosols to the mid-Pacific than those occurring in other seasons. In addition, inter-annual variability of sBC* is seen over the Northern Pacific, with abundances varying consistently with the springtime Pacific/North American (PNA) index. Our sBC* dataset infers a widespread overestimation of BC loadings and BC Direct Radiative Forcing by current models over North Pacific, which further suggests that large uncertainties exist on aerosol-climate interactions over other remote oceanic areas beyond Pacific. PMID:28266532

An experimental and numerical study of the light scattering properties of ice crystals with black carbon inclusions

NASA Astrophysics Data System (ADS)

Arienti, Marco; Geier, Manfred; Yang, Xiaoyuan; Orcutt, John; Zenker, Jake; Brooks, Sarah D.

2018-05-01

We investigate the optical properties of ice crystals nucleated on atmospheric black carbon (BC). The parameters examined in this study are the shape of the ice crystal, the volume fraction of the BC inclusion, and its location inside the crystal. We report on new spectrometer measurements of forward scattering and backward polarization from ice crystals nucleated on BC particles and grown under laboratory-controlled conditions. Data from the Cloud and Aerosol Spectrometer with Polarization (CASPOL) are used for direct comparison with single-particle calculations of the scattering phase matrix. Geometrical optics and discrete dipole approximation techniques are jointly used to provide the best compromise of flexibility and accuracy over a broad range of size parameters. Together with the interpretation of the trends revealed by the CASPOL measurements, the numerical results confirm previous reports on absorption cross-section magnification in the visible light range. Even taking into account effects of crystal shape and inclusion position, the ratio between absorption cross-section of the compound particle and the absorption cross-section of the BC inclusion alone (the absorption magnification) has a lower bound of 1.5; this value increases to 1.7 if the inclusion is centered with respect to the crystal. The simple model of BC-ice particle presented here also offers new insights on the effect of the relative position of the BC inclusion with respect to the crystal's outer surfaces, the shape of the crystal, and its size.

What are the controls on mountain snowmelt and runoff around the globe?

NASA Astrophysics Data System (ADS)

Painter, T. H.

2017-12-01

The Anthropocene has seen a marked expulsion of mass from mountain glaciers to oceans and earlier snowmelt that evacuates the mountains earlier in the year. The loss of ice mass and snow cover is often attributed to increasing temperatures. However, process studies across the last two decades indicate that acceleration of melt by dust/black carbon (BC) may dominate in some regions. Process studies with detailed energy balance measurements around the globe are relatively sparse but strongly suggestive of the impact of dust and BC. Mesoscale and global scale modeling have recently taken on radiative transfer modeling of snow albedo that accounts for changes in grain size and dust/BC concentrations and optical properties. However, our understanding of metamorphism and changes in grain growth still has considerable range of uncertainty that, when passed through radiative transfer modeling, far exceeds in magnitude the at-surface greenhouse gas forcing of 3 W m-2. Likewise, it is a rare study that provides the quantitative knowledge of seasonal variation of dust and BC concentrations, let alone the range of optical properties. Therefore, the energy balance of snow in mountains around the globe is poorly understood and our capacity to model past, present, and future hydrologic responses is relatively weak. Atop the energy balance uncertainties, we also still do not know the spatio-temporal distributions of snow water equivalent in mountain basins around the globe. With the advent of the NASA Airborne Snow Observatory in 2013, we entered a new era of understanding mountain basin SWE. ASO uses scanning lidar, imaging spectrometer, and physical modeling to map distributions across basins in California, Colorado, and the Swiss Alps. The program is expanding in these and other regions for water management. However, in the science realm, in addition to providing the capacity to understand distributed SWE and its change, ASO is also pathfinding through the NASA Snow Experiment (SnowEx) for a spaceborne snow depth and SWE mission that can provide the global perspective we need. The next few decades hold enormous potential to quantify mountain snow pack and to constrain physically-based climate models to allow us to answer the title question here and where the cryosphere-water cycles are heading.

Constraining Black Carbon Aerosol over Asia using OMI Aerosol Absorption Optical Depth and the Adjoint of GEOS-Chem

NASA Technical Reports Server (NTRS)

Zhang, Li; Henze, David K.; Grell, Georg A.; Carmichael. Gregory R.; Bousserez, Nicolas; Zhang, Qiang; Torres, Omar; Ahn, Changwoo; Lu, Zifeng; Cao, Junji;

Heuristics guide the implementation of social preferences in one-shot Prisoner's Dilemma experiments

PubMed Central

Capraro, Valerio; Jordan, Jillian J.; Rand, David G.

2014-01-01

Cooperation in one-shot anonymous interactions is a widely documented aspect of human behaviour. Here we shed light on the motivations behind this behaviour by experimentally exploring cooperation in a one-shot continuous-strategy Prisoner's Dilemma (i.e. one-shot two-player Public Goods Game). We examine the distribution of cooperation amounts, and how that distribution varies based on the benefit-to-cost ratio of cooperation (b/c). Interestingly, we find a trimodal distribution at all b/c values investigated. Increasing b/c decreases the fraction of participants engaging in zero cooperation and increases the fraction engaging in maximal cooperation, suggesting a role for efficiency concerns. However, a substantial fraction of participants consistently engage in 50% cooperation regardless of b/c. The presence of these persistent 50% cooperators is surprising, and not easily explained by standard models of social preferences. We present evidence that this behaviour is a result of social preferences guided by simple decision heuristics, rather than the rational examination of payoffs assumed by most social preference models. We also find a strong correlation between play in the Prisoner's Dilemma and in a subsequent Dictator Game, confirming previous findings suggesting a common prosocial motivation underlying altruism and cooperation. PMID:25348470

Heuristics guide the implementation of social preferences in one-shot Prisoner's Dilemma experiments.

PubMed

Capraro, Valerio; Jordan, Jillian J; Rand, David G

2014-10-28

Cooperation in one-shot anonymous interactions is a widely documented aspect of human behaviour. Here we shed light on the motivations behind this behaviour by experimentally exploring cooperation in a one-shot continuous-strategy Prisoner's Dilemma (i.e. one-shot two-player Public Goods Game). We examine the distribution of cooperation amounts, and how that distribution varies based on the benefit-to-cost ratio of cooperation (b/c). Interestingly, we find a trimodal distribution at all b/c values investigated. Increasing b/c decreases the fraction of participants engaging in zero cooperation and increases the fraction engaging in maximal cooperation, suggesting a role for efficiency concerns. However, a substantial fraction of participants consistently engage in 50% cooperation regardless of b/c. The presence of these persistent 50% cooperators is surprising, and not easily explained by standard models of social preferences. We present evidence that this behaviour is a result of social preferences guided by simple decision heuristics, rather than the rational examination of payoffs assumed by most social preference models. We also find a strong correlation between play in the Prisoner's Dilemma and in a subsequent Dictator Game, confirming previous findings suggesting a common prosocial motivation underlying altruism and cooperation.

Relating black carbon content to reduction of snow albedo

NASA Astrophysics Data System (ADS)

Brandt, R. E.; Warren, S. G.; Clarke, A. D.

2011-12-01

In remote snow of the Northern Hemisphere, the levels of soot pollution are in the parts-per-billion (ppb) range, where the effect on albedo is at the level of a few percent. A reduction of albedo by 1-2% is significant for climate but is difficult to detect experimentally, because snow albedo depends on several other variables. In our work to quantify the climatic effect of black carbon (BC) in snow, we therefore do not directly measure the albedo reduction. Instead, we use a two-step procedure: (1) We collect snow samples, melt and filter them, and analyze the filters spectrophotometrically for BC concentration. (2) We use the BC amount from the filter measurement, together with snow grain size, in a radiative transfer model to compute the albedo reduction. Our radiative transfer model uses the discrete ordinates algorithm DISORT 2.0. We have chosen a representative BC size distribution and optical constants, and have incorporated those of mineral dust as well. While a given mass of BC causes over an order of magnitude more snow albedo reduction compared to dust, a snowpack containing dust mutes the albedo-reducing effect of BC. Because the computed reduction of snow albedo is model-based, it requires experimental verification. We doubt that direct measurement of albedo-reduction will be feasible in nature, because of the vertical variation of both snow grain size and soot content, and because the natural soot content is small. We conclude that what is needed is an artificial snowpack, with uniform grain size and large uniform soot content (ppm not ppb), to produce a large signal on albedo. We have chosen to pursue this experiment outdoors rather than in the laboratory, for the following reasons: (1) The snowpack in the field of view is uniformly illuminated if the source of radiation is the Sun. (2) Visible radiation penetrates into the snow, so photons emerge horizontally distant from where they entered. In the limited width of a laboratory snowpack, radiation may be absorbed by the walls of the container. (3) In a laboratory experiment only a narrow field of view can be measured, rather than a hemispheric field of view, so a laboratory experiment measures the bidirectional reflectance for particular angles rather than albedo. The disadvantage of an outdoor experiment is that one must wait for appropriate weather: low temperature (-20 to -40 C), calm winds, diffuse incident radiation, and no precipitation during the experiment. Using a small snowmaking machine, a snowpack of area 75 square meters and depth 15 cm is made in a period of 4 hours, deposited over a natural snowpack. A soot suspension is maintained in a sonicated bath, which can be entrained into the water stream. Two snowpacks are made side-by-side, with and without added soot. For a soot content of 1 ppm, 3 g soot were dispersed into 3 tons of snow. The spectral albedos of the two snowpacks are in agreement for near-infrared wavelengths beyond 1 micrometer, but diverge at shorter wavelengths, as expected. The soot particles in the artificial snowpack are probably located mostly inside ice grains, but the measured albedo reduction implies a mass-absorption cross-section of about 6 square meters per gram, close to that expected for an external mixture.

Black carbon aerosol-induced Northern Hemisphere tropical expansion

DOE PAGES

Kovilakam, Mahesh; Mahajan, Salil

2015-06-23

Global climate models (GCMs) underestimate the observed trend in tropical expansion. Recent studies partly attribute it to black carbon (BC) aerosols, which are poorly represented in GCMs. In this paper, we conduct a suite of idealized experiments with the Community Atmosphere Model version 4 coupled to a slab ocean model forced with increasing BC concentrations covering a large swath of the estimated range of current BC radiative forcing while maintaining their spatial distribution. The Northern Hemisphere (NH) tropics expand poleward nearly linearly as BC radiative forcing increases (0.7° W -1 m 2), indicating that a realistic representation of BC couldmore » reduce GCM biases. We find support for the mechanism where BC-induced midlatitude tropospheric heating shifts the maximum meridional tropospheric temperature gradient poleward resulting in tropical expansion. Finally, we also find that the NH poleward tropical edge is nearly linearly correlated with the location of the Intertropical Convergence Zone, which shifts northward in response to increasing BC.« less

In situ synthesis of silver-nanoparticles/bacterial cellulose composites for slow-released antimicrobial wound dressing.

PubMed

Wu, Jian; Zheng, Yudong; Song, Wenhui; Luan, Jiabin; Wen, Xiaoxiao; Wu, Zhigu; Chen, Xiaohua; Wang, Qi; Guo, Shaolin

2014-02-15

Bacterial cellulose has attracted increasing attention as a novel wound dressing material, but it has no antimicrobial activity, which is one of critical skin-barrier functions in wound healing. To overcome such deficiency, we developed a novel method to synthesize and impregnate silver nanoparticles on to bacterial cellulose nanofibres (AgNP-BC). Uniform spherical silver nano-particles (10-30 nm) were generated and self-assembled on the surface of BC nano-fibers, forming a stable and evenly distributed Ag nanoparticles coated BC nanofiber. Such hybrid nanostructure prevented Ag nanoparticles from dropping off BC network and thus minimized the toxicity of nanoparticles. Regardless the slow Ag(+) release, AgNP-BC still exhibited significant antibacterial activities with more than 99% reductions in Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Moreover, AgNP-BC allowed attachment and growth of epidermal cells with no cytotoxicity emerged. The results demonstrated that AgNP-BC could reduce inflammation and promote wound healing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Towards Soil and Sediment Inventories of Black Carbon

NASA Astrophysics Data System (ADS)

Masiello, C. A.

2008-12-01

A body of literature on black carbon (BC) concentrations in soils and sediments is rapidly accumulating, but as of yet, there are no global or regional inventories of BC in either reservoir. Soil and sediment BC inventories are badly needed for a range of fields. For example, in oceanography a global sediment BC inventory is crucial in understanding the role of biomass burning in the development of stable marine carbon reservoirs, including dissolved organic carbon and sedimentary organic carbon. Again in the marine environment, BC likely strongly impacts the fate and transport of anthropogenic pollutants: regional inventories of BC in sediments will help develop better environmental remediation strategies. In terrestrial systems well-constrained natural BC soil inventories would help refine ecological, agricultural, and soil biogeochemical studies. BC is highly sorptive of nutrients including nitrogen and phosphorous. The presence of BC in ecosystems almost certainly alters N and P cycling; however, without soil BC inventories, we cannot know where BC has a significant impact. BC's nutrient sorptivity and water-holding capacity make it an important component of agricultural soils, and some researchers have proposed artificially increasing soil BC inventories to improve soil fertility. Natural soil BC concentrations in some regions are quite high, but without a baseline inventory, it is challenging to predict when agricultural amendment will significantly exceed natural conditions. And finally, because BC is one of the most stable fractions of organic carbon in soils, understanding its concentration and regional distribution will help us track the dynamics of soil organic matter response to changing environmental conditions. Developing effective regional and global BC inventories is challenging both because of data sparsity and methodological intercomparison issues. In this presentation I will describe a roadmap to generating these valuable inventories.

Evaluation of Methods for the Determination of Black Carbon Emissions from an Aircraft Gas Turbine Engine

EPA Science Inventory

The emissions from aircraft gas turbine engines consist of nanometer size black carbon (BC) particles plus gas-phase sulfur and organic compounds which undergo gas-to-particle conversion downstream of the engine as the plume cools and dilutes. In this study, four BC measurement ...

Carbon and nitrogen mineralization and enzyme activities in soil aggregate-size classes: Effects of biochar, oyster shells, and polymers.

PubMed

Awad, Yasser Mahmoud; Lee, Sang Soo; Kim, Ki-Hyun; Ok, Yong Sik; Kuzyakov, Yakov

2018-05-01

Biochar (BC) and polymers are cost-effective additives for soil quality improvement and long-term sustainability. The additional use of the oyster shells (OS) powder in BC- or polymer-treated soils is recommended as a nutrient source, to enhance aggregation and to increase enzyme activities. The effects of soil treatments (i.e., BC (5 Mg ha -1 ) and polymers (biopolymer at 0.4 Mg ha -1 or polyacrylamide at 0.4 Mg ha -1 ) with or without the OS (1%)) on the short-term changes were evaluated based on a 30-day incubation experiment with respect to several variables (e.g., CO 2 release, NH 4 + and NO 3 - concentrations, aggregate-size classes, and enzyme activities in an agricultural Luvisol). The BC and BP with the addition of OS increased the portion of microaggregates (<0.25 mm) relative to the control soil without any additions, while PAM alone increased the portion of large macroaggregates (1-2 mm). Concentrations of NO 3 - also increased in soils treated with OS, OS + BC, and OS + BP as result of the increased chitinase and leucine aminopeptidase activities. The BC and BP when treated with the additional OS had significant short-term impacts on N mineralization without affecting C mineralization in soil. Consequently, the combination of BC or BP with OS was seen to accelerate N turnover without affecting C turnover (and related C losses) from soil. As such, the addition of these additives contributed considerably to the improvement of soil fertility and C sequestration. Copyright © 2018 Elsevier Ltd. All rights reserved.

An insight into the adsorption of diclofenac on different biochars: Mechanisms, surface chemistry, and thermodynamics.

PubMed

Lonappan, Linson; Rouissi, Tarek; Kaur Brar, Satinder; Verma, Mausam; Surampalli, Rao Y

2018-02-01

Biochars were prepared from feedstocks pinewood and pig manure. Biochar microparticles obtained through grinding were evaluated for the removal of emerging contaminant diclofenac (DCF) and the underlying mechanism were thoroughly studied. Characterization of biochar was carried out using particle size analyzer, SEM, BET, FT-IR, XRD, XPS and zeta potential instrument. Pig manure biochar (BC-PM) exhibited excellent removal efficiency (99.6%) over pine wood biochar (BC-PW) at 500 µg L -1 of DCF (environmentally significant concentration). Intraparticle diffusion was found to be the major process facilitated the adsorption. BC-PW followed pseudo first-order kinetics whereas BC-PM followed pseudo second-order kinetics. Pine wood biochar was largely affected by pH variations whereas for pig manure biochar, pH effects were minimal owing to its surface functional groups and DCF hydrophobicity. Thermodynamics, presence of co-existing ions, initial adsorbate concentration and particles size played substantial role in adsorption. Various isotherms models were also studied and results are presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Study on BC Emission from Vehicles using Different Types of Fuel

NASA Astrophysics Data System (ADS)

Kim, K.; Son, J.; Kim, J.; Kim, S.; Park, G.; Sung, K.; Kim, I.; Chung, T.; Park, T.; Kang, S.; Ban, J.; Kim, J.; Hong, Y. D.; Woo, J. H.; Lee, T.

2017-12-01

Black carbon (BC) is an anthropogenic aerosol from fossil fuels, and biomass burning. It absorbs solar radiation, and heats the atmosphere leading 0.4W m-2 radiative forcing. BC is a particle that can cause serious effects on human body as well. Toxicological studies of black carbon suggests that BC may be an important carrier of toxic chemicals to human body. The recent researches show that one of the main precursor of BC is vehicle emission, but the inventory of BC emission rate from vehicle is inadequate in South Korea. This study tries to find differences of BC emission from different sizes of vehicles using different types of fuels. Fuels used in vehicles are gasoline, liquefied petroleum gas (LPG), and diesel. BC was directly measured from the tail pipe of vehicles using Aethalometer (AE33, Magee Scientific Corporation). This study was conducted in Transport Pollutant Research Center, National Institute of Environmental Research, South Korea. Measurement was progressed with the five different test modes of speeds. Speed modes includes 4.7, 17.3, 34.1, 65.4, and 97.3 km h-1. Emission rate of BC was high in the slowest speed mode, and showed decrease with increase of the speed of vehicles. Gasoline vehicles had the relatively higher emission rate of BC than the LPG vehicle, while the emission rate of BC for Diesel with DPF (Diesel Particle Filter) was observed to be the lowest.

Efficient Extraction of High Centrality Vertices in Distributed Graphs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumbhare, Alok; Frincu, Marc; Raghavendra, Cauligi S.

2014-09-09

Betweenness centrality (BC) is an important measure for identifying high value or critical vertices in graphs, in variety of domains such as communication networks, road networks, and social graphs. However, calculating betweenness values is prohibitively expensive and, more often, domain experts are interested only in the vertices with the highest centrality values. In this paper, we first propose a partition-centric algorithm (MS-BC) to calculate BC for a large distributed graph that optimizes resource utilization and improves overall performance. Further, we extend the notion of approximate BC by pruning the graph and removing a subset of edges and vertices that contributemore » the least to the betweenness values of other vertices (MSL-BC), which further improves the runtime performance. We evaluate the proposed algorithms using a mix of real-world and synthetic graphs on an HPC cluster and analyze its strengths and weaknesses. The experimental results show an improvement in performance of upto 12x for large sparse graphs as compared to the state-of-the-art, and at the same time highlights the need for better partitioning methods to enable a balanced workload across partitions for unbalanced graphs such as small-world or power-law graphs.« less

Can Breast Cancer Biopsy Influence Sentinel Lymph Node Status?

PubMed

Giuliani, Michela; Patrolecco, Federica; Rella, Rossella; Di Giovanni, Silvia Eleonora; Infante, Amato; Rinaldi, Pierluigi; Romani, Maurizio; Mulè, Antonino; Arciuolo, Damiano; Belli, Paolo; Bonomo, Lorenzo

2016-12-01

We evaluated whether the needle size could influence metastasis occurrence in the axillary sentinel lymph node (SLN) in ultrasound-guided core needle biopsy (US-CNB) of breast cancer (BC). The data from all patients with breast lesions who had undergone US-CNB at our institution from January 2011 to January 2015 were retrospectively reviewed. A total of 377 BC cases were included using the following criteria: (1) percutaneous biopsy-proven invasive BC; and (2) SLN dissection with histopathologic examination. The patients were divided into 2 groups according to the needle size used: 14 gauge versus 16 or 18 gauge. SLN metastasis classification followed the 7th American Joint Committee on Cancer (2010) TNM pathologic staging factors: macrometastases, micrometastases, isolated tumor cells, or negative. Only macrometastases and micrometastases were considered positive, and the positive and negative rates were calculated for the overall population and for both needle size groups. Of the 377 BC cases, 268 US-CNB procedures were performed using a 14-gauge needle and 109 with a 16- or 18-gauge needle, respectively. The negative rate was significantly related statistically with the needle size, with a greater prevalence in the 14-gauge group on both extemporaneous analysis (P = .019) and definitive analysis (P = .002). The macrometastasis rate was 17% (63 of 377) for the 14-gauge and 3% (12 of 377) for the 16- and 18-gauge needles, respectively. Our preliminary results have suggested that use of a large needle size in CNB does not influence SLN status; thus, preoperative breast biopsy can be considered a safe procedure in the diagnosis of malignant breast lesions. Copyright © 2016 Elsevier Inc. All rights reserved.

Black Carbon in Estuarine and Coastal Ocean Dissolved Organic Matter

NASA Technical Reports Server (NTRS)

Mannino, Antonio; Harvey, H. Rodger

2003-01-01

Black carbon (BC) in ultrafiltered high-molecular-weight DOM (UDOM) was measured in surface waters of Delaware Bay, Chesapeake Bay and the adjacent Atlantic Ocean (USA) to ascertain the importance of riverine and estuarine DOM as a source of BC to the ocean. BC comprised 5-72% of UDOM-C (27+/-l7%) and on average 8.9+/-6.5% of dissolved organic carbon (DOC) with higher values in the turbid region of the Delaware Estuary and lower yields in the river and coastal ocean. The spatial and seasonal distributions of BC along the salinity gradient of Delaware Bay suggest that the higher levels of BC in surface water UDOM originated from localized sources, possibly from atmospheric deposition or released from resuspended sediments. Black carbon comprised 4 to 7% of the DOC in the coastal Atlantic Ocean, revealing that river-estuary systems are important exporters of colloidal BC to the ocean. The annual flux of BC from Delaware Bay UDOM to the Atlantic Ocean was estimated at 2.4x10(exp 10) g BC yr(exp -1). The global river flux of BC through DOM to the ocean could be on the order of 5.5x1O(exp 12)g BC yr (exp -1). These results support the hypothesis that the DOC pool is the intermediate reservoir in which BC ages prior to sedimentary deposition.

Historical record of black carbon in urban soils and its environmental implications.

PubMed

He, Yue; Zhang, Gan-Lin

2009-10-01

Energy use in urbanization has fundamentally changed the pattern and fluxes of carbon cycling, which has global and local environmental impacts. Here we have investigated organic carbon (OC) and black carbon (BC) in six soil profiles from two contrast zones in an ancient city (Nanjing) in China. BC in soils was widely variable, from 0.22 to 32.19 g kg(-1). Its average concentration in an ancient residential area (Zone 1) was, 0.91 g kg(-1), whereas in Zone 2, an industrial and commercial area, the figure was 8.62 g kg(-1). The ratio of BC/OC ranged from 0.06 to 1.29 in soil profiles, with an average of 0.29. The vertical distribution of BC in soil is suggested to reflect the history of BC formation from burning of biomass and/or fossil fuel. BC in the surface layer of soils was mainly from traffic emission (especially from diesel vehicles). In contrast, in cultural layers BC was formed from historical coal use. The contents of BC and the ratio of BC/OC may reflect different human activities and pollution sources in the contrasting urban zones. In addition, the significant correlation of heavy metals (Cu, Pb, and Zn) with BC contents in some culture layers suggests the sorption of the metals by BC or their coexistence resulted from the coal-involved smelting.

Scavenging ratio of black carbon in the Arctic and the Antarctic

NASA Astrophysics Data System (ADS)

Gogoi, Mukunda M.; Babu, S. Suresh; Pandey, Santosh K.; Nair, Vijayakumar S.; Vaishya, Aditya; Girach, I. A.; Koushik, N.

2018-06-01

Long-term monitoring of atmospheric aerosols and their interaction with radiation, cloud, and cryosphere over the Arctic and the Antarctic are very important for the global climate change related issues. In this regard, for conducting aerosol measurements, India has extended the concerted efforts to the Svalbard region of the Norwegian Arctic (Himadri, 78°55‧N 11°56‧E, 8 m a.s.l.) in the northern hemisphere and the Larsemann Hills of coastal Antarctic (Bharati, 69°24.4‧S 76°11.7‧E, 40 m a.s.l.) in the southern hemisphere. In the present study, we have examined the role of black carbon (BC) deposition in darkening the polar snow in different sunlit seasons and estimated the scavenging ratio of BC over both the poles from simultaneous measurements of atmospheric and snow deposited BC concentrations. The study reveals distinct spatio-temporal variability of BC in polar snow, even though the concentrations are, in general, low (<12 ppbw, parts per billion by weight). During local summer seasons, the BC in snow at the Arctic (median ∼ 7.98 ppbw) was higher than that at the Antarctica (median ∼ 1.70 ppbw). Concurrent with this, the scavenging ratio (SR) also showed large variability over both the poles. Relatively higher values of SR over the Antarctica (mean ∼ 119.54 ± 23.04; during southern hemispheric summer) in comparison to that over the Arctic (mean ∼ 69.48 ± 4.79; during northern hemispheric spring) clearly indicate the difference in removal mechanisms (aerosol mixing, aging and size distribution) of BC from the atmosphere over distinct polar environments. Measurement of spectral incoming and reflected radiances over the Arctic snow during the early spring season of 2017 indicated the values of surface broadband albedo varying between 0.64 and 0.79. The Snow, Ice and Aerosol Radiative (SNICAR) model simulated values of spectral albedo correlated well with the measured ones and indicated the role of dust absorption, in addition to that of BC, in changing the snow albedo. This information needs to be accurately incorporated in the radiative transfer models for the accurate estimation of snow albedo forcing over the Polar Regions.

Seasonality of global and Arctic black carbon processes in the Arctic Monitoring and Assessment Programme models: Global and Arctic Black Carbon Processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahmood, Rashed; von Salzen, Knut; Flanner, Mark

2016-06-22

This study quantifies black carbon (BC) processes in three global climate models and one chemistry transport model, with focus on the seasonality of BC transport, emissions, wet and dry deposition in the Arctic. In the models, transport of BC to the Arctic from lower latitudes is the major BC source for this region while Arctic emissions are very small. All models simulated a similar annual cycle of BC transport from lower latitudes to the Arctic, with maximum transport occurring in July. Substantial differences were found in simulated BC burdens and vertical distributions, with CanAM (NorESM) producing the strongest (weakest) seasonalmore » cycle. CanAM also has the shortest annual mean residence time for BC in the Arctic followed by SMHI-MATCH, CESM and NorESM. The relative contribution of wet and dry deposition rates in removing BC varies seasonally and is one of the major factors causing seasonal variations in BC burdens in the Arctic. Overall, considerable differences in wet deposition efficiencies in the models exist and are a leading cause of differences in simulated BC burdens. Results from model sensitivity experiments indicate that scavenging of BC in convective clouds acts to substantially increase the overall efficiency of BC wet deposition in the Arctic, which leads to low BC burdens and a more pronounced seasonal cycle compared to simulations without convective BC scavenging. In contrast, the simulated seasonality of BC concentrations in the upper troposphere is only weakly influenced by wet deposition in stratiform (layer) clouds whereas lower tropospheric concentrations are highly sensitive.« less

PTK 7 Is a Transforming Gene and Prognostic Marker for Breast Cancer and Nodal Metastasis Involvement

PubMed Central

Knyazeva, Tatiana; Wolf, Petra; Högel, Bernhard; Eiermann, Wolfgang; Ullrich, Axel; Knyazev, Pjotr; Ataseven, Beyhan

2014-01-01

Protein Tyrosin Kinase 7 (PTK7) is upregulated in several human cancers; however, its clinical implication in breast cancer (BC) and lymph node (LN) is still unclear. In order to investigate the function of PTK7 in mediating BC cell motility and invasivity, PTK7 expression in BC cell lines was determined. PTK7 signaling in highly invasive breast cancer cells was inhibited by a dominant-negative PTK7 mutant, an antibody against the extracellular domain of PTK7, and siRNA knockdown of PTK7. This resulted in decreased motility and invasivity of BC cells. We further examined PTK7 expression in BC and LN tissue of 128 BC patients by RT-PCR and its correlation with BC related genes like HER2, HER3, PAI1, MMP1, K19, and CD44. Expression profiling in BC cell lines and primary tumors showed association of PTK7 with ER/PR/HER2-negative (TNBC-triple negative BC) cancer. Oncomine data analysis confirmed this observation and classified PTK7 in a cluster with genes associated with agressive behavior of primary BC. Furthermore PTK7 expression was significantly different with respect to tumor size (ANOVA, p = 0.033) in BC and nodal involvement (ANOVA, p = 0.007) in LN. PTK7 expression in metastatic LN was related to shorter DFS (Cox Regression, p = 0.041). Our observations confirmed the transforming potential of PTK7, as well as its involvement in motility and invasivity of BC cells. PTK7 is highly expressed in TNBC cell lines. It represents a novel prognostic marker for BC patients and has potential therapeutic significance. PMID:24409301

Cross-polar transport and scavenging of Siberian aerosols containing black carbon during the 2012 ACCESS summer campaign

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raut, Jean -Christophe; Marelle, Louis; Fast, Jerome D.

During the ACCESS airborne campaign in July 2012, extensive boreal forest fires resulted in significant aerosol transport to the Arctic. A 10-day episode combining intense biomass burning over Siberia and low-pressure systems over the Arctic Ocean resulted in efficient transport of plumes containing black carbon (BC) towards the Arctic, mostly in the upper troposphere (6–8 km). Here, a combination of in situ observations (DLR Falcon aircraft), satellite analysis and WRF-Chem simulations is used to understand the vertical and horizontal transport mechanisms of BC with a focus on the role of wet removal. Between the northwestern Norwegian coast and the Svalbardmore » archipelago, the Falcon aircraft sampled plumes with enhanced CO concentrations up to 200 ppbv and BC mixing ratios up to 25 ng kg –1. During transport to the Arctic region, a large fraction of BC particles are scavenged by two wet deposition processes, namely wet removal by large-scale precipitation and removal in wet convective updrafts, with both processes contributing almost equally to the total accumulated deposition of BC. Our results underline that applying a finer horizontal resolution (40 instead of 100 km) improves the model performance, as it significantly reduces the overestimation of BC levels observed at a coarser resolution in the mid-troposphere. According to the simulations at 40 km, the transport efficiency of BC (TE BC) in biomass burning plumes was larger (60 %), because it was impacted by small accumulated precipitation along trajectory (1 mm). In contrast TE BC was small (< 30 %) and accumulated precipitation amounts were larger (5–10 mm) in plumes influenced by urban anthropogenic sources and flaring activities in northern Russia, resulting in transport to lower altitudes. TE BC due to large-scale precipitation is responsible for a sharp meridional gradient in the distribution of BC concentrations. Wet removal in cumulus clouds is the cause of modeled vertical gradient of TE BC, especially in the mid-latitudes, reflecting the distribution of convective precipitation, but is dominated in the Arctic region by the large-scale wet removal associated with the formation of stratocumulus clouds in the planetary boundary layer (PBL) that produce frequent drizzle.« less

Cross-polar transport and scavenging of Siberian aerosols containing black carbon during the 2012 ACCESS summer campaign

DOE PAGES

Raut, Jean -Christophe; Marelle, Louis; Fast, Jerome D.; ...

2017-09-15

During the ACCESS airborne campaign in July 2012, extensive boreal forest fires resulted in significant aerosol transport to the Arctic. A 10-day episode combining intense biomass burning over Siberia and low-pressure systems over the Arctic Ocean resulted in efficient transport of plumes containing black carbon (BC) towards the Arctic, mostly in the upper troposphere (6–8 km). Here, a combination of in situ observations (DLR Falcon aircraft), satellite analysis and WRF-Chem simulations is used to understand the vertical and horizontal transport mechanisms of BC with a focus on the role of wet removal. Between the northwestern Norwegian coast and the Svalbardmore » archipelago, the Falcon aircraft sampled plumes with enhanced CO concentrations up to 200 ppbv and BC mixing ratios up to 25 ng kg –1. During transport to the Arctic region, a large fraction of BC particles are scavenged by two wet deposition processes, namely wet removal by large-scale precipitation and removal in wet convective updrafts, with both processes contributing almost equally to the total accumulated deposition of BC. Our results underline that applying a finer horizontal resolution (40 instead of 100 km) improves the model performance, as it significantly reduces the overestimation of BC levels observed at a coarser resolution in the mid-troposphere. According to the simulations at 40 km, the transport efficiency of BC (TE BC) in biomass burning plumes was larger (60 %), because it was impacted by small accumulated precipitation along trajectory (1 mm). In contrast TE BC was small (< 30 %) and accumulated precipitation amounts were larger (5–10 mm) in plumes influenced by urban anthropogenic sources and flaring activities in northern Russia, resulting in transport to lower altitudes. TE BC due to large-scale precipitation is responsible for a sharp meridional gradient in the distribution of BC concentrations. Wet removal in cumulus clouds is the cause of modeled vertical gradient of TE BC, especially in the mid-latitudes, reflecting the distribution of convective precipitation, but is dominated in the Arctic region by the large-scale wet removal associated with the formation of stratocumulus clouds in the planetary boundary layer (PBL) that produce frequent drizzle.« less

High resolution of black carbon and organic carbon emissions in the Pearl River Delta region, China.

PubMed

Zheng, Junyu; He, Min; Shen, Xingling; Yin, Shasha; Yuan, Zibing

2012-11-01

A high-resolution regional black carbon (BC) and organic carbon (OC) emission inventory for the year 2009 was developed for the Pearl River Delta (PRD) region, China, based on the collected activity data and the latest emission factors. PM(2.5), BC and OC emissions were estimated to be 303 kt, 39 kt and 31 kt, respectively. Industrial processes were major contributing sources to PM(2.5) emissions. BC emissions were mainly from mobile sources, accounting for 65.0%, while 34.1% of OC emissions were from residential combustion. The primary OC/BC ratios for individual cities in the PRD region were dependent on the levels of economic development due to differences in source characteristics, with high ratios in the less developed cities and low ratios in the central and southern developed areas. The preliminary temporal profiles were established, showing the highest OC emissions in winter and relatively constant BC emissions throughout the year. The emissions were spatially allocated into grid cells with a resolution of 3 km × 3 km. Large amounts of BC emissions were distributed over the central-southern PRD city clusters, while OC emissions exhibited a relatively even spatial distribution due to the significant biomass burning emissions from the outlying area of the PRD region. Uncertainties in carbonaceous aerosol emissions were usually higher than in other primary pollutants like SO(2), NO(x), and PM(10). One of the key uncertainty sources was the emission factor, due to the absence of direct measurements of BC and OC emission rates. Copyright © 2012 Elsevier B.V. All rights reserved.

Dependence of columnar aerosol size distribution, optical properties, and chemical components on regional transport in Beijing

NASA Astrophysics Data System (ADS)

Wang, Shuo; Zhao, Weixiong; Xu, Xuezhe; Fang, Bo; Zhang, Qilei; Qian, Xiaodong; Zhang, Weijun; Chen, Weidong; Pu, Wei; Wang, Xin

2017-11-01

Seasonal dependence of the columnar aerosol optical and chemical properties on regional transport in Beijing over 10 years (from January 2005 to December 2014) were analyzed by using the ground-based remote sensing combined with backward trajectory analysis. Daily air mass backward trajectories terminated in Beijing were computed with HYSPLIT-4 model and were categorized into five clusters. The columnar mass concentrations of black carbon (BC), brown carbon (BrC), dust (DU), aerosol water content (AW), and ammonium sulfate like aerosol (AS) of each cluster were retrieved from the optical data obtained from the Aerosol Robotic NETwork (AERONET) with five-component model. It was found that the columnar aerosol properties in different seasons were changed, and they were related to the air mass origins. In spring, aerosol was dominated by coarse particles. Summer was characterized by higher single scattering albedo (SSA), lower real part of complex refractive index (n), and obvious hygroscopic growth due to humid air from the south. During autumn and winter, there was an observable increase in absorption aerosol optical thickness (AAOT) and the imaginary part of complex refraction (k), with high levels of retrieved BC and BrC. However, concentrations of BC showed less dependence on the clusters during the two seasons owing to the widely spread coal heating in north China.

Targeting Androgen Receptor in Breast Cancer: Enzalutamide as a Novel Breast Cancer Therapeutic

DTIC Science & Technology

2016-09-01

for Public Release; Distribution Unlimited The views, opinions and/or findings contained in this report are those of the author(s) and should not be...activity in breast cancer as a single agent and in combination with exemestane. Activity is seen in both triple negative AR + BC and also ER+ AR + BC...Clinical data in Her2+ AR + BC is too immature to make conclusions. The proposed clinical trials for Years 3-5 appear to be justified based on

Reduction of uncertainty in global black carbon direct radiative forcing constrained by observations

NASA Astrophysics Data System (ADS)

Wang, R.; Balkanski, Y.; Boucher, O.; Ciais, P.; Schuster, G. L.; Chevallier, F.; Samset, B. H.; Valari, M.; Liu, J.; Tao, S.

2017-12-01

Black carbon (BC) absorbs sunlight and contributes to global warming. However, the size of this effect, namely the direct radiative forcing (DRF), ranges from +0.1 to +1.0 W m-2, largely due to discrepancies between modeled and observed BC radiation absorption. Studies that adjusted emissions to correct biases of models resulted in a revised upward estimate of the BC DRF. However, the observation-based BC RF was not optimized against observations in a rigorous mathematical manner, because uncertainties in emissions and the representativeness errors due to use of coarse-resolution models were not fully assessed. Here we simulated the absorption of solar radiation by BC from all sources at the 10-km resolution by combining a nested aerosol model with a downscaling method. The normalized mean bias in BC radiation absorption was reduced from -51% to -24% in Asia and from -57% to -50% elsewhere. We applied a Bayesian method that account for model, representativeness and observational uncertainties to estimate the BC RF and its uncertainty. Using the high-resolution model reduces uncertainty in BC DRF from -101%/+152% to -70%/+71% over Asia and from -83%/+108% to -64%/+68% over other continental regions. We derived an observation-based BC DRF of 0.61 Wm-2 (0.16 to 1.40 as 90% confidence) as our best estimate.

Single-Particle Measurements of Midlatitude Black Carbon and Light-Scattering Aerosols from the Boundary Layer to the Lower Stratosphere

NASA Technical Reports Server (NTRS)

Schwartz, J. P.; Gao, R. S.; Fahey, D. W.; Thomson, D. S.; Watts, L. A.; Wilson, J. C.; Reeves, J. M.; Darbeheshti, M.; Baumgardner, D. G.; Kok, G. L.;

Temporal variations and spatial distribution of ambient PM2.2 and PM10 concentrations in Dhaka, Bangladesh.

PubMed

Begum, Bilkis A; Biswas, Swapan K; Hopke, Philip K

2006-04-01

Concentrations and characteristics of airborne particulate matter (PM(10), PM(2.2) and BC) on air quality have been studied at two air quality-monitoring stations in Dhaka, the capital of Bangladesh. One site is at the Farm Gate area, a hot spot with very high pollutant concentrations because of its proximity to major roadways. The other site is at a semi-residential area located at the Atomic Energy Centre, Dhaka Campus, (AECD) with relatively less traffic. The samples were collected using a 'Gent' stacked filter unit in two fractions of 0-2.2 mum and 2.2-10 mum sizes. Samples of fine (PM(2.2)) and coarse (PM(2.2-10)) airborne particulate matter fractions collected from 2000 to 2003 were studied. It has been observed that fine particulate matter has a decreasing trend, from prior year measurements, because of Government policy interventions like phase-wise plans to take two-stroke three-wheelers off the roads in Dhaka and finally banned from January 1, 2003. Other policy interventions were banning of old buses and trucks to ply on Dhaka city promotion of the using compressed natural gas (CNG), introducing air pollution control devices in vehicles, etc. It was found that both local (mostly from vehicular emissions) and possibly some regional emission sources are responsible for high PM(2.2) and BC concentrations in Dhaka. PM(2.2), PM(2.2-10) and black carbon concentration levels depend on the season, wind direction and wind speed. Transport related emissions are the major source of BC and long-range transportation from fossil fuel related sources and biomass burning could be another substantial source of BC.

A theory-based parameterization for heterogeneous ice nucleation and implications for the simulation of ice processes in atmospheric models

NASA Astrophysics Data System (ADS)

Savre, J.; Ekman, A. M. L.

2015-05-01

A new parameterization for heterogeneous ice nucleation constrained by laboratory data and based on classical nucleation theory is introduced. Key features of the parameterization include the following: a consistent and modular modeling framework for treating condensation/immersion and deposition freezing, the possibility to consider various potential ice nucleating particle types (e.g., dust, black carbon, and bacteria), and the possibility to account for an aerosol size distribution. The ice nucleating ability of each aerosol type is described using a contact angle (θ) probability density function (PDF). A new modeling strategy is described to allow the θ PDF to evolve in time so that the most efficient ice nuclei (associated with the lowest θ values) are progressively removed as they nucleate ice. A computationally efficient quasi Monte Carlo method is used to integrate the computed ice nucleation rates over both size and contact angle distributions. The parameterization is employed in a parcel model, forced by an ensemble of Lagrangian trajectories extracted from a three-dimensional simulation of a springtime low-level Arctic mixed-phase cloud, in order to evaluate the accuracy and convergence of the method using different settings. The same model setup is then employed to examine the importance of various parameters for the simulated ice production. Modeling the time evolution of the θ PDF is found to be particularly crucial; assuming a time-independent θ PDF significantly overestimates the ice nucleation rates. It is stressed that the capacity of black carbon (BC) to form ice in the condensation/immersion freezing mode is highly uncertain, in particular at temperatures warmer than -20°C. In its current version, the parameterization most likely overestimates ice initiation by BC.

Early postnatal response of the spinal nucleus of the bulbocavernosus and target muscles to testosterone in male gerbils.

PubMed

Hadi Mansouri, S; Siegford, Janice M; Ulibarri, Catherine

2003-05-14

This study examined the response of the spinal nucleus of the bulbocavernosus (SNB) and the bulbocavernosus (BC) muscle, to testosterone in male Mongolian gerbils (Meriones unguiculatus) during the early postnatal period. Male gerbil pups were given testosterone propionate (TP) or vehicle for 2 days, then perfused on postnatal day (PND) 3, 5, 10 or 15. The BC and levator ani (LA) muscles were removed, weighed, and sectioned. Cross-sections of BC muscle fibers were measured and muscle fiber morphology examined. Spinal cords were removed and coronally sectioned in order to count and measure the SNB motoneurons. Following TP treatment, male pups of all ages had significantly heavier BC-LA muscles and larger fibers in the BC muscle compared to age-matched controls. The increase in muscle weight following TP treatment was greatest at PND10, while fiber size increased to a similar degree at all ages suggesting that hyperplasia as well as hypertrophy was responsible for the increase in muscle mass at this time. SNB motoneurons increased significantly in number and size with age and TP treatment. We hypothesize that the increase in SNB motoneuron number during normal ontogeny that can be augmented by TP treatment and represents an unusual means of establishing sexual dimorphism in the nervous system of a mammal through cell recruitment to the motor pool of a postnatal animal.

Black Carbon at the Mt. Bachelor Observatory Field Campaign Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaffe, Dan A.; Sedlacek, Arthur; Laing, James R.

This campaign was initiated to measure refractory black carbon (rBC, as defined in Schwarz et al. (2010)) at the Mt. Bachelor Observatory (MBO) using the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility single-particle soot photometer (SP2; unit 54). MBO is a high-elevation site located on the summit of Mt. Bachelor in central Oregon, USA (43.979°N, 121.687°W, 2,763 meters ASL). This site is operated by Professor Dan Jaffe’s group at the University of Washington Bothell and has been used continuously as an atmospheric observatory for the past 12 years (Jaffe et al., 2005; Gratz et al.,more » 2014). The location of MBO allows frequent sampling of the free troposphere along with a wide array of plumes from regional and distant sources. MBO is currently supported with funding from the National Science Foundation (NSF) to the Principal Investigator (PI; D. Jaffe) via the project “Influence of Free Tropospheric Ozone and PM on Surface Air Quality in the Western U.S.” (#1447832) covering the period 03/15/2015 to 02/28/2018. The SP2 instrument from Droplet Measurement Technologies provides particle-resolved measurements of rBC mass loading, size and mass distributions, and mixing state. The SP2 was installed at MBO on 6/27/2016 and ran through 9/23/2016. Additional measurements at MBO during this campaign included carbon monoxide (CO), fine particulate matter (PM1), aerosol light scattering coefficients (σscat) at three wavelengths using a TSI nephelometer, aerosol absorption coefficients (σabs) with the Brechtel tricolor absorption photometer (TAP), aerosol number size distributions with a scanning mobility particle sizer spectrometer (SMPS), and black carbon (eBC) with an aethalometer. BC data from this campaign have been submitted to the ARM Data Archive. Black carbon (BC) is the predominant light-absorbing aerosol constituent in the atmosphere, and is estimated to exert a positive radiative forcing second only to CO 2 (Ramanathan and Carmichael, 2008). One of the largest sources of BC globally is biomass burning (BB). (Akagi et al., 2011; Andreae and Merlet, 2001; Bond et al., 2013; Bond et al., 2004; Reid et al., 2005b): a source that is likely to increase in the Western U.S. due to climate change (Dennison et al., 2014; Abatzoglon and Williams, 2016; Westerling et al., 2006). Given the likely increased role of BB aerosol in atmospheric forcing, we need to improve our understanding of the physical and optical properties of aged BB aerosol. During the SP2 deployment period at MBO we observed seven BB events, all of which originated from the Gap Fire in Northern California, which burned 33,867 acres in the Klamath National Forest (https://inciweb.nwcg.gov/incident/4997/). Heavy smoke plumes from this fire were transported to MBO from 8/29/2016 to 8/31/2016. We calculated back-trajectories using the National Oceanic and Atmospheric Administration (NOAA) Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, version 4 (Draxler, 1999; Draxler and Hess, 1997, 1998; Stein et al., 2015) to confirm transport from the fire locations to MBO. We identified the fire locations using moderate resolution imaging spectroradiometer (MODIS) satellite-derived active fire counts (Justice et al., 2002). Transport time for all of the BB events ranged from 8 to 32 hours.« less

Quantification of black carbon mixing state from traffic: Implications for aerosol optical properties

DOE PAGES

Willis, Megan D.; Healy, Robert M.; Riemer, Nicole; ...

2016-04-14

The climatic impacts of black carbon (BC) aerosol, an important absorber of solar radiation in the atmosphere, remain poorly constrained and are intimately related to its particle-scale physical and chemical properties. Using particle-resolved modelling informed by quantitative measurements from a soot-particle aerosol mass spectrometer, we confirm that the mixing state (the distribution of co-emitted aerosol amongst fresh BC-containing particles) at the time of emission significantly affects BC-aerosol optical properties even after a day of atmospheric processing. Both single particle and ensemble aerosol mass spectrometry observations indicate that BC near the point of emission co-exists with hydrocarbon-like organic aerosol (HOA) inmore » two distinct particle types: HOA-rich and BC-rich particles. The average mass fraction of black carbon in HOA-rich and BC-rich particle classes was < 0.1 and 0.8, respectively. Notably, approximately 90 % of BC mass resides in BC-rich particles. This new measurement capability provides quantitative insight into the physical and chemical nature of BC-containing particles and is used to drive a particle-resolved aerosol box model. Lastly, significant differences in calculated single scattering albedo (an increase of 0.1) arise from accurate treatment of initial particle mixing state as compared to the assumption of uniform aerosol composition at the point of BC injection into the atmosphere.« less

Distribution and Sources of Black Carbon in the Arctic

NASA Astrophysics Data System (ADS)

Qi, Ling

The Arctic is warming at twice the global rate over recent decades. To slow down this warming trend, there is growing interest in reducing the impact from short-lived climate forcers, such as black carbon (BC), because the benefits of mitigation are seen more quickly relative to CO2 reduction. To propose efficient mitigation policies, it is imperative to improve our understanding of BC distribution in the Arctic and to identify the sources. In this dissertation, we investigate the sensitivity of BC in the Arctic, including BC concentrations in snow (BCsnow) and BC concentrations in air (BCair), to emissions, dry deposition and wet scavenging using a global 3-D chemical transport model (CTM) GEOS-Chem. By including flaring emissions, estimating dry deposition velocity using resistance-in-series method, and including Wegener-Bergeron-Findeisen (WBF) in wet scavenging, simulated BCsnow in the eight Arctic sub-regions agree with the observations within a factor of two, and simulated BCair fall within the uncertainty range of observations. Specifically, we find that natural gas flaring emissions in Western Extreme North of Russia (WENR) strongly enhance BCsnow (by up to ?50%) and BCair (by 20-32%) during snow season in the so-called 'Arctic front', but has negligible impact on BC in the free troposphere. The updated dry deposition velocity over snow and ice is much larger than those used in most of global CTMs and agrees better with observation. The resulting BCsnow changes marginally because of the offsetting of higher dry and lower wet deposition fluxes. In contrast, surface BCair decreases strongly due to the faster dry deposition (by 27-68%). WBF occurs when the environmental vapor pressure is in between the saturation vapor pressure of ice crystals and water drops in mixed-phase clouds. As a result, water drops evaporate and releases BC particles in them back into the interstitial air. In most CTMs, WBF is either missing or represented by a uniform and low BC scavenging efficiency. In this dissertation, we relate WBF with temperature and ice mass fraction based on long-term observations in mixed-phase clouds. We find that WBF reduces BC scavenging efficiency globally, with larger decrease at higher latitude and altitude (from 8% in the tropics to 76% in the Arctic). WBF slows down and reduces wet deposition of BC and leave more BC in the atmosphere. Higher BC air results in larger dry deposition. The resulting total deposition is lower in mid-latitudes (by 12-34%) and higher in the Arctic (2-29%). Globally, including WBF significantly reduces the discrepancy of BCsnow (by 50%), BCair (by 50%), and washout ratios (by a factor of two to four). The remaining discrepancies in these variables suggest that in-cloud removal is likely still excessive over land. In the last part, we identify sources of surface atmospheric BC in the Arctic in springtime, when radiative forcing is the largest due to the high insolation and surface albedo. We find a large contribution from Asian anthropogenic sources (40-43%) and open biomass burning emissions from forest fires in South Siberia (29-41%). Outside the Arctic front, BC is strongly enhanced by episodic, direct transport events from Asia and Siberia after 12 days of transport. In contrast, in the Arctic front, a large fraction of the Asian contribution is in the form of 'chronic' pollution on 1-2 month timescale. As such, it is likely that previous studies using 5- or 10-day trajectory analyses strongly underestimated the contribution from Asia to surface BC in the Arctic. Our results point toward an urgent need for better characterization of flaring emissions of BC (e.g. the emission factors, temporal and spatial distribution), extensive measurements of both the dry deposition of BC over snow and ice, and the scavenging efficiency of BC in mixed-phase clouds, particularly over Ocean. More measurements of 14C are needed to better understand sources of BC (fossil fuel combustion versus biomass burning) and to provide additional constrain on BC simulations.

Radiative effect of black carbon aerosol on a squall line case in North China

NASA Astrophysics Data System (ADS)

Fu, Shizuo; Deng, Xin; Li, Zhe; Xue, Huiwen

2017-11-01

The radiative effect of black carbon aerosol (BC) on a squall line case in north China is studied with the Weather Research and Forecasting model. Before the initiation of the squall line, the surface-emitted BC is mixed only in the boundary layer (BL). BC is then transported from the BL into the free troposphere by the updrafts in the squall line system. Once distributed in the atmosphere, BC absorbs solar radiation and heats the surrounding air. The maximum increase of temperature is 0.05 K for the moderately polluted case bc2 and 0.37 K for the heavily polluted case bc20. In case bc2, where the BC concentration is not very high, the solar flux reaching the surface, the sensible heat flux, and the latent heat flux are not significantly affected by BC. In case bc20, the solar flux reaching the surface, the sensible heat flux, and the latent heat flux are reduced by up to 80, 30, and 21 W m- 2, respectively. The reduced surface evaporation leads to a reduced vapor amount at the early stage. After some time, the heating effect causes a large-scale convergence and brings slightly more vapor into the domain. The effect of BC on the cold pool strength and low-level wind shear is small and hence does not significantly affect the triggering of new convections. In addition, our results show that the effect of BC is negligible on the strength and rain rate of the squall line case.

Long non-coding RNA BRAF-regulated lncRNA 1 promotes lymph node invasion, metastasis and proliferation, and predicts poor prognosis in breast cancer.

PubMed

Jiang, Jing; Shi, Sheng-Hong; Li, Xu-Jun; Sun, Long; Ge, Qi-Dong; Li, Chao; Zhang, Wei

2018-06-01

Long non-coding RNAs (lncRNAs) are primary regulators of cancer development via their involvement in almost every aspect of cell biology. Recent studies have indicated that lncRNAs serve pivotal roles in breast cancer (BC) progression; however, to the best of our knowledge, the role of the lncRNA BRAF-regulated lncRNA 1 (BANCR) in BC has not yet been elucidated. The present study revealed that BANCR was overexpressed in BC cell lines and tissues, and could promote the clinical progression of disease, including increases in tumor size, lymph node metastasis and Tumor-Node-Metastasis stage. Furthermore, high BANCR expression was demonstrated to be associated with poor overall survival rates and early recurrence of BC in patients. Additionally, univariate and multivariate COX regression analyses identified high BANCR expression as an independent risk factor of poor prognosis of patients with BC. In addition, to verify the function of BANCR in BC cell lines, BANCR expression was silenced using short hairpin RNAs in MDA-MB-231 cells and overexpressed in MDA-MB-468 cells. An MTT assay and colony formation assay indicated that BANCR knockdown could suppress the proliferation of BC cells, whereas BANCR upregulation induced the proliferation of BC cells. Furthermore, BANCR silencing also reduced the migration and invasion of BC cells, as demonstrated via transwell migration and invasion assays. Consistently, the migration and invasion of BC cells increased upon BANCR ectopic overexpression in MDA-MB-468 cells. Mechanistically, matrix metallopeptidase 2/9 and epithelial-mesenchymal transition markers may be the potential targets of BANCR in regulating BC metastasis. In conclusion, BANCR overexpression could promote the clinical progression, metastasis and proliferation of BC and indicate poor prognosis of patients with BC. BANCR may therefore be a potential prognostic marker and therapeutic target of patients with BC.

Genome-wide association study to identify common variants associated with brachial circumference: a meta-analysis of 14 cohorts.

PubMed

Boraska, Vesna; Day-Williams, Aaron; Franklin, Christopher S; Elliott, Katherine S; Panoutsopoulou, Kalliope; Tachmazidou, Ioanna; Albrecht, Eva; Bandinelli, Stefania; Beilin, Lawrence J; Bochud, Murielle; Cadby, Gemma; Ernst, Florian; Evans, David M; Hayward, Caroline; Hicks, Andrew A; Huffman, Jennifer; Huth, Cornelia; James, Alan L; Klopp, Norman; Kolcic, Ivana; Kutalik, Zoltán; Lawlor, Debbie A; Musk, Arthur W; Pehlic, Marina; Pennell, Craig E; Perry, John R B; Peters, Annette; Polasek, Ozren; St Pourcain, Beate; Ring, Susan M; Salvi, Erika; Schipf, Sabine; Staessen, Jan A; Teumer, Alexander; Timpson, Nicholas; Vitart, Veronique; Warrington, Nicole M; Yaghootkar, Hanieh; Zemunik, Tatijana; Zgaga, Lina; An, Ping; Anttila, Verneri; Borecki, Ingrid B; Holmen, Jostein; Ntalla, Ioanna; Palotie, Aarno; Pietiläinen, Kirsi H; Wedenoja, Juho; Winsvold, Bendik S; Dedoussis, George V; Kaprio, Jaakko; Province, Michael A; Zwart, John-Anker; Burnier, Michel; Campbell, Harry; Cusi, Daniele; Smith, George Davey; Frayling, Timothy M; Gieger, Christian; Palmer, Lyle J; Pramstaller, Peter P; Rudan, Igor; Völzke, Henry; Wichmann, H-Erich; Wright, Alan F; Zeggini, Eleftheria

2012-01-01

Brachial circumference (BC), also known as upper arm or mid arm circumference, can be used as an indicator of muscle mass and fat tissue, which are distributed differently in men and women. Analysis of anthropometric measures of peripheral fat distribution such as BC could help in understanding the complex pathophysiology behind overweight and obesity. The purpose of this study is to identify genetic variants associated with BC through a large-scale genome-wide association scan (GWAS) meta-analysis. We used fixed-effects meta-analysis to synthesise summary results across 14 GWAS discovery and 4 replication cohorts comprising overall 22,376 individuals (12,031 women and 10,345 men) of European ancestry. Individual analyses were carried out for men, women, and combined across sexes using linear regression and an additive genetic model: adjusted for age and adjusted for age and BMI. We prioritised signals for follow-up in two-stages. We did not detect any signals reaching genome-wide significance. The FTO rs9939609 SNP showed nominal evidence for association (p<0.05) in the age-adjusted strata for men and across both sexes. In this first GWAS meta-analysis for BC to date, we have not identified any genome-wide significant signals and do not observe robust association of previously established obesity loci with BC. Large-scale collaborations will be necessary to achieve higher power to detect loci underlying BC.

Genome-Wide Association Study to Identify Common Variants Associated with Brachial Circumference: A Meta-Analysis of 14 Cohorts

PubMed Central

Boraska, Vesna; Day-Williams, Aaron; Franklin, Christopher S.; Elliott, Katherine S.; Panoutsopoulou, Kalliope; Tachmazidou, Ioanna; Albrecht, Eva; Bandinelli, Stefania; Beilin, Lawrence J.; Bochud, Murielle; Cadby, Gemma; Ernst, Florian; Evans, David M.; Hayward, Caroline; Hicks, Andrew A.; Huffman, Jennifer; Huth, Cornelia; James, Alan L.; Klopp, Norman; Kolcic, Ivana; Kutalik, Zoltán; Lawlor, Debbie A.; Musk, Arthur W.; Pehlic, Marina; Pennell, Craig E.; Perry, John R. B.; Peters, Annette; Polasek, Ozren; Pourcain, Beate St; Ring, Susan M.; Salvi, Erika; Schipf, Sabine; Staessen, Jan A.; Teumer, Alexander; Timpson, Nicholas; Vitart, Veronique; Warrington, Nicole M.; Yaghootkar, Hanieh; Zemunik, Tatijana; Zgaga, Lina; An, Ping; Anttila, Verneri; Borecki, Ingrid B.; Holmen, Jostein; Ntalla, Ioanna; Palotie, Aarno; Pietiläinen, Kirsi H.; Wedenoja, Juho; Winsvold, Bendik S.; Dedoussis, George V.; Kaprio, Jaakko; Province, Michael A.; Zwart, John-Anker; Burnier, Michel; Campbell, Harry; Cusi, Daniele; Davey Smith, George; Frayling, Timothy M.; Gieger, Christian; Palmer, Lyle J.; Pramstaller, Peter P.; Rudan, Igor; Völzke, Henry; Wichmann, H. -Erich; Wright, Alan F.; Zeggini, Eleftheria

2012-01-01

Brachial circumference (BC), also known as upper arm or mid arm circumference, can be used as an indicator of muscle mass and fat tissue, which are distributed differently in men and women. Analysis of anthropometric measures of peripheral fat distribution such as BC could help in understanding the complex pathophysiology behind overweight and obesity. The purpose of this study is to identify genetic variants associated with BC through a large-scale genome-wide association scan (GWAS) meta-analysis. We used fixed-effects meta-analysis to synthesise summary results across 14 GWAS discovery and 4 replication cohorts comprising overall 22,376 individuals (12,031 women and 10,345 men) of European ancestry. Individual analyses were carried out for men, women, and combined across sexes using linear regression and an additive genetic model: adjusted for age and adjusted for age and BMI. We prioritised signals for follow-up in two-stages. We did not detect any signals reaching genome-wide significance. The FTO rs9939609 SNP showed nominal evidence for association (p<0.05) in the age-adjusted strata for men and across both sexes. In this first GWAS meta-analysis for BC to date, we have not identified any genome-wide significant signals and do not observe robust association of previously established obesity loci with BC. Large-scale collaborations will be necessary to achieve higher power to detect loci underlying BC. PMID:22479309

Effect of MERRA-2 initial and boundary conditions on WRF-Chem aerosol simulations over the Arabian Peninsula

NASA Astrophysics Data System (ADS)

Ukhov, Alexander; Stenchikov, Georgiy

2017-04-01

In this study, we test the sensitivity of the horizontal and vertical distributions of aerosols to the initial and boundary conditions (IC&BC) of the aerosol/chemistry. We use the WRF-Chem model configured over the Arabian Peninsula to study both dust and anthropogenic aerosols. Currently, in the WRF-Chem the aerosol/chemistry IC&BC are constructed using either default aerosol/chemistry profiles with no inflow of aerosols and chemicals through the lateral boundaries or using the aerosol/chemistry fields from MOZART, the model for ozone and related chemical tracers from the NCAR. Here, we construct aerosol/chemistry IC&BC using MERRA-2 output. MERRA-2 is a recently developed reanalysis that assimilates ground-based and satellite observations to provide the improved distributions of aerosols and chemical species. We ran WRF-Chem simulations for July-August 2015 using GOCART/AFWA dust emission and GOCART aerosol schemes. We used the EDGAR HTAP V4 dataset to calculate SO2 emissions. Comparison of three runs initiated using the same ERA-Interim reanalysis fields but different aerosol/chemistry IC&BC (default WRF-Chem, MOZART, and MERRA-2) with AERONET, Micropulse Lidar, Balloon, and satellite observations shows that the MERRA-2 IC&BC are superior.

Analysis of transpacific transport of black carbon during HIPPO-3: implications for black carbon aging

NASA Astrophysics Data System (ADS)

Shen, Z.; Liu, J.; Horowitz, L. W.; Henze, D. K.; Fan, S.; Levy, H., II; Mauzerall, D. L.; Lin, J.-T.; Tao, S.

2014-06-01

Long-range transport of black carbon (BC) is a growing concern as a result of the efficiency of BC in warming the climate and its adverse impact on human health. We study transpacific transport of BC during HIPPO-3 using a combination of inverse modeling and sensitivity analysis. We use the GEOS-Chem chemical transport model and its adjoint to constrain Asian BC emissions and estimate the source of BC over the North Pacific. We find that different sources of BC dominate the transport to the North Pacific during the southbound (29 March 2010) and northbound (13 April 2010) measurements in HIPPO-3. While biomass burning in Southeast Asia (SE) contributes about 60% of BC in March, more than 90% of BC comes from fossil fuel and biofuel combustion in East Asia (EA) during the April mission. GEOS-Chem simulations generally resolve the spatial and temporal variation of BC concentrations over the North Pacific, but are unable to reproduce the low and high tails of the observed BC distribution. We find that the optimized BC emissions derived from inverse modeling fail to improve model simulations significantly. This failure indicates that uncertainties in BC removal as well as transport, rather than in emissions, account for the major biases in GEOS-Chem simulations of BC over the North Pacific. The aging process, transforming BC from hydrophobic into hydrophilic form, is one of the key factors controlling wet scavenging and remote concentrations of BC. Sensitivity tests on BC aging (ignoring uncertainties of other factors controlling BC long range transport) suggest that in order to fit HIPPO-3 observations, the aging timescale of anthropogenic BC from EA may be several hours (faster than assumed in most global models), while the aging process of biomass burning BC from SE may occur much slower, with a timescale of a few days. To evaluate the effects of BC aging and wet deposition on transpacific transport of BC, we develop an idealized model of BC transport. We find that the mid-latitude air masses sampled during HIPPO-3 may have experienced a series of precipitation events, particularly near the EA and SE source region. Transpacific transport of BC is sensitive to BC aging when the aging rate is fast; this sensitivity peaks when the aging timescale is in the range of 1-1.5 d. Our findings indicate that BC aging close to the source must be simulated accurately at a process level in order to simulate better the global abundance and climate forcing of BC.

Spatializing 6,000 years of global urbanization from 3700 BC to AD 2000

NASA Astrophysics Data System (ADS)

Reba, Meredith; Reitsma, Femke; Seto, Karen C.

2016-06-01

How were cities distributed globally in the past? How many people lived in these cities? How did cities influence their local and regional environments? In order to understand the current era of urbanization, we must understand long-term historical urbanization trends and patterns. However, to date there is no comprehensive record of spatially explicit, historic, city-level population data at the global scale. Here, we developed the first spatially explicit dataset of urban settlements from 3700 BC to AD 2000, by digitizing, transcribing, and geocoding historical, archaeological, and census-based urban population data previously published in tabular form by Chandler and Modelski. The dataset creation process also required data cleaning and harmonization procedures to make the data internally consistent. Additionally, we created a reliability ranking for each geocoded location to assess the geographic uncertainty of each data point. The dataset provides the first spatially explicit archive of the location and size of urban populations over the last 6,000 years and can contribute to an improved understanding of contemporary and historical urbanization trends.

Spatializing 6,000 years of global urbanization from 3700 BC to AD 2000

PubMed Central

Reba, Meredith; Reitsma, Femke; Seto, Karen C.

2016-01-01

How were cities distributed globally in the past? How many people lived in these cities? How did cities influence their local and regional environments? In order to understand the current era of urbanization, we must understand long-term historical urbanization trends and patterns. However, to date there is no comprehensive record of spatially explicit, historic, city-level population data at the global scale. Here, we developed the first spatially explicit dataset of urban settlements from 3700 BC to AD 2000, by digitizing, transcribing, and geocoding historical, archaeological, and census-based urban population data previously published in tabular form by Chandler and Modelski. The dataset creation process also required data cleaning and harmonization procedures to make the data internally consistent. Additionally, we created a reliability ranking for each geocoded location to assess the geographic uncertainty of each data point. The dataset provides the first spatially explicit archive of the location and size of urban populations over the last 6,000 years and can contribute to an improved understanding of contemporary and historical urbanization trends. PMID:27271481

Comparing four methods to estimate usual intake distributions.

PubMed

Souverein, O W; Dekkers, A L; Geelen, A; Haubrock, J; de Vries, J H; Ocké, M C; Harttig, U; Boeing, H; van 't Veer, P

2011-07-01

The aim of this paper was to compare methods to estimate usual intake distributions of nutrients and foods. As 'true' usual intake distributions are not known in practice, the comparison was carried out through a simulation study, as well as empirically, by application to data from the European Food Consumption Validation (EFCOVAL) Study in which two 24-h dietary recalls (24-HDRs) and food frequency data were collected. The methods being compared were the Iowa State University Method (ISU), National Cancer Institute Method (NCI), Multiple Source Method (MSM) and Statistical Program for Age-adjusted Dietary Assessment (SPADE). Simulation data were constructed with varying numbers of subjects (n), different values for the Box-Cox transformation parameter (λ(BC)) and different values for the ratio of the within- and between-person variance (r(var)). All data were analyzed with the four different methods and the estimated usual mean intake and selected percentiles were obtained. Moreover, the 2-day within-person mean was estimated as an additional 'method'. These five methods were compared in terms of the mean bias, which was calculated as the mean of the differences between the estimated value and the known true value. The application of data from the EFCOVAL Project included calculations of nutrients (that is, protein, potassium, protein density) and foods (that is, vegetables, fruit and fish). Overall, the mean bias of the ISU, NCI, MSM and SPADE Methods was small. However, for all methods, the mean bias and the variation of the bias increased with smaller sample size, higher variance ratios and with more pronounced departures from normality. Serious mean bias (especially in the 95th percentile) was seen using the NCI Method when r(var) = 9, λ(BC) = 0 and n = 1000. The ISU Method and MSM showed a somewhat higher s.d. of the bias compared with NCI and SPADE Methods, indicating a larger method uncertainty. Furthermore, whereas the ISU, NCI and SPADE Methods produced unimodal density functions by definition, MSM produced distributions with 'peaks', when sample size was small, because of the fact that the population's usual intake distribution was based on estimated individual usual intakes. The application to the EFCOVAL data showed that all estimates of the percentiles and mean were within 5% of each other for the three nutrients analyzed. For vegetables, fruit and fish, the differences were larger than that for nutrients, but overall the sample mean was estimated reasonably. The four methods that were compared seem to provide good estimates of the usual intake distribution of nutrients. Nevertheless, care needs to be taken when a nutrient has a high within-person variation or has a highly skewed distribution, and when the sample size is small. As the methods offer different features, practical reasons may exist to prefer one method over the other.

Breast cancer age at diagnosis patterns in four Latin American Populations: A comparison with North American countries.

PubMed

Franco-Marina, Francisco; López-Carrillo, Lizbeth; Keating, Nancy L; Arreola-Ornelas, Hector; Marie Knaul, Felicia

2015-12-01

In the Latin America countries (LAC), one in five breast cancer (BC) cases occur in women younger than 45 years, almost twice the frequency seen in developed countries. Most BC cases in younger women are premenopausal and are generally more difficult to detect at early stages and to treat than postmenopausal cancers. We employ data from four high quality population-based registries located in LAC and assess the extent to which the higher frequency of BC occurring in younger women is due to a younger population structure, compared to that of developed countries. Next, we analyze secular and generational trends of incidence rates in search for additional explanations. Using data from the International Agency for Research on cancer, between 1988 and 2007, the age distribution of BC incident cases for registries located in Brazil, Colombia, Costa Rica, Ecuador is compared to that of USA and Canadian registries, both before and after removing differences in population age structure. An age-period-cohort modelling of incidence rates is also conducted in all compared registries to identify secular and generational effects. BC incident cases in the LAC registries present, on average, at an earlier age than in the USA and Canadian registries and for 2003-2007, between 20 and 27% of cases occur in women aged 20-44. About two thirds of the difference in age distribution between LAC and USA registries is attributable to the younger age distribution in the LAC base populations. The USA registries show the highest age-specific BC incidence rates of all compared aggregated registries, at all ages. However, in all the LAC registries incidence rates are rapidly increasing, fueled by a strong birth cohort effect. This cohort effect may be explained by important reduction in fertility rates occurring during the second half of the 20th century, but also by a greater exposure to other risk factors for BC related to the adoption of life styles more prevalent in developed countries. The younger age at presentation of BC incident cases seen in the analyzed LAC registries, and possibly in many Latin American countries, is not only attributable to their relatively young population age structure but also to the low incidence rates in older women. As more recently born cohorts, with greater exposure to risk factors for postmenopausal BC, reach older age, incidence rates will be more similar to the rates seen in the USA and Canadian registries. There is a need for additional research to identify determinants of the higher BC rate among younger women in these countries. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impact of Plasma Surface Treatment on Bamboo Charcoal/silver Nanocomposite

NASA Astrophysics Data System (ADS)

Vignesh, K.; Vijayalakshmi, K. A.; Karthikeyan, N.

2016-10-01

Bamboo charcoal (BC) accompanied silver (Ag) nanocomposite is synthesized through sol-gel method. The produced BC/Ag nanocomposite was surface modified by air and oxygen plasma treatments. Silver ions (Ag+) will serve to improve the antibacterial activity as well as the surface area of BC. Plasma treatment has improved the surface functional groups, crystalline intensity and antibacterial activity of the prepared nanocomposite. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies show that Ag nanoparticles have good agreement with BC and the particle size has a mean diameter of 20-40nm. We observe the carboxyl functional groups in Fourier transform infrared spectroscopy (FTIR) after the oxygen plasma treatment. Moreover surface area and adsorption were analyzed by using the Brunauer, Emmett and Teller (BET) surface area (SBET) and UV-Vis spectroscopy.

Importance of suspended sediment (SPS) composition and grain size in the bioavailability of SPS-associated pyrene to Daphnia magna.

PubMed

Xia, Xinghui; Zhang, Xiaotian; Zhou, Dong; Bao, Yimeng; Li, Husheng; Zhai, Yawei

2016-07-01

Hydrophobic organic compounds (HOCs) tend to associate with suspended sediment (SPS) in aquatic environments; the composition and grain size of SPS will affect the bioavailability of SPS-associated HOCs. However, the bioavailability of HOCs sorbed on SPS with different compositions and grain sizes is not well understood. In this work, passive dosing devices were made to control the freely dissolved concentration of pyrene, a typical HOC, in the exposure systems. The effect of pyrene associated with amorphous organic carbon (AOC), black carbon (BC), and minerals of SPS with grain sizes of 0-50 μm and 50-100 μm on the immobilization and enzymatic activities of Daphnia magna was investigated to quantify the bioavailability of pyrene sorbed on SPS with different grain sizes and compositions. The results showed that the contribution of AOC-, BC-, and mineral-associated pyrene to the total bioavailability of SPS-associated pyrene was approximately 50%-60%, 10%-29%, and 20%-30%, respectively. The bioavailable fraction of pyrene sorbed on the three components of SPS was ordered as AOC (22.4%-67.3%) > minerals (20.1%-46.0%) > BC (9.11%-16.8%), and the bioavailable fraction sorbed on SPS of 50-100 μm grain size was higher than those of 0-50 μm grain size. This is because the SPS grain size will affect the ingestion of SPS and the SPS composition will affect the desorption of SPS-associated pyrene in Daphnia magna. According to the results obtained in this study, a model has been developed to calculate the bioavailability of HOCs to aquatic organisms in natural waters considering both SPS grain size and composition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Temporal variation and source identification of black carbon at Lin'an and Longfengshan regional background stations in China

NASA Astrophysics Data System (ADS)

Cheng, Siyang; Wang, Yaqiang; An, Xingqin

2017-12-01

Black carbon (BC) is a component of fine particulate matter (PM2.5), associated with climate, weather, air quality, and people's health. However, studies on temporal variation of atmospheric BC concentration at background stations in China and its source area identification are lacking. In this paper, we use 2-yr BC observations from two background stations, Lin'an (LAN) and Longfengshan (LFS), to perform the investigation. The results show that the mean diurnal variation of BC has two significant peaks at LAN while different characteristics are found in the BC variation at LFS, which are probably caused by the difference in emission source contributions. Seasonal variation of monthly BC shows double peaks at LAN but a single peak at LFS. The annual mean concentrations of BC at LAN and LFS decrease by 1.63 and 0.26 μg m-3 from 2009 to 2010, respectively. The annual background concentration of BC at LAN is twice higher than that at LFS. The major source of the LAN BC is industrial emission while the source of the LFS BC is residential emission. Based on transport climatology on a 7-day timescale, LAN and LFS stations are sensitive to surface emissions respectively in belt or approximately circular area, which are dominated by summer monsoon or colder land air flows in Northwest China. In addition, we statistically analyze the BC source regions by using BC observation and FLEXible PARTicle dispersion model (FLEXPART) simulation. In summer, the source regions of BC are distributed in the northwest and south of LAN and the southwest of LFS. Low BC concentration is closely related to air mass from the sea. In winter, the source regions of BC are concentrated in the west and south of LAN and the northeast of the threshold area of s tot at LFS. The cold air mass in the northwest plays an important role in the purification of atmospheric BC. On a yearly scale, sources of BC are approximately from five provinces in the northwest/southeast of LAN and the west of LFS. These findings are helpful in reducing BC emission and controlling air pollution.

Mobility of black carbon in drained peatland soils

NASA Astrophysics Data System (ADS)

Leifeld, J.; Fenner, S.; Müller, M.

2007-06-01

Amount, stability, and distribution of black carbon (BC) were studied at four sites of a large peatland ("Witzwil") formerly used as a disposal for combustion residues from households to derive BC displacement rates in the profile. Possible artefacts from thermal oxidation with Differential Scanning Calorimetry (DSC) on BC quantification of C-rich deposits were inferred by choosing three sites from a second peatland with no historical record of waste disposal as a reference ("Seebodenalp"). All sites were under grassland at time of sampling, but were partially cropped in the past at Witzwil. Mean BC contents in topsoils of Witzwil ranged from 10.7 to 91.5 (0-30 cm) and from 0.44 to 51.3 (30-140 cm) mg BC g-1 soil, corresponding to BC/OC ratios of 0.04 to 0.3 (topsoil) and 0.02 to 0.18 (deeper soil). At three sites of Seebodenalp, BC was below the detection limit of 0.4 mg g-1 organic soil, indicating negligible formation of BC during thermal oxidation of peat. 13C NMR spectra corroborated the high BC contents at Witzwil. The data support a considerable vertical transport of BC given that soils were ploughed not deeper than 30 cm since abandonment of waste application about 50 years ago. The total amount of BC in the Witzwil profiles ranged from 3.2 to 7.5 kg BC m-2, with 21 to 69 percent of it stemming from below the former ploughing depth. Under the premise of negligible rates of BC consumption since abandonment of waste application, minimum BC transport rates in these peats are 0.6 to 1.2 cm a-1. The high mobility of BC might be explained by high macro-pore volumes in combination with occasional water saturation. By means of DSC peak temperatures, different types of BC could be distinguished, with deeper horizons containing BC of higher thermal stability. Application of combustion residues likely involved a mixture of various BC types, of which thermally more stable ones, most likely soots, were preferentially transported downwards.

Mobility of black carbon in drained peatland soils

NASA Astrophysics Data System (ADS)

Leifeld, J.; Fenner, S.; Müller, M.

2007-03-01

Amount, stability, and distribution of black carbon BC were studied at four sites of a large peatland ("Witzwil") formerly used as a disposal for combustion residues from households to derive BC displacement rates in the profile. Possible artefacts from thermal oxidation with Differential Scanning Calorimetry (DSC) on BC quantification of C-rich deposits were inferred by choosing three sites from a second peatland with no historical record of waste disposal as a reference ("Seebodenalp"). All sites were under grassland at time of sampling, but were partially cropped in the past at Witzwil. Mean BC contents in topsoils of Witzwil ranged from 10.7 to 91.5 (0-30 cm) and from 0.44 to 51.3 (30-140 cm) mg BC g-1 soil, corresponding to BC/OC ratios of 0.04 to 0.3 (topsoil) and 0.02 to 0.18 (deeper soil). At three sites of Seebodenalp, BC was below the detection limit of 0.4 mg g-1 organic soil, indicating negligible formation of BC during thermal oxidation of peat. 13C NMR spectra corroborated the high BC contents at Witzwil. The data refer to a considerable vertical transport of BC given that soils were ploughed not deeper than 30 cm since abandonment of waste application about 50 years ago. The total amount of BC in the Witzwil profiles ranged from 3.2 to 7.5 kg BC m-2, with 21 to 69 percent of it stemming from below the former ploughing depth. Under the premise of negligible rates of BC consumption since abandonment of waste application, minimum BC transport rates in these peats are 0.6 to 1.2 cm a-1. The high mobility of BC might be explained by high macro-pore volumes in combination with occasional water saturation. By means of DSC peak temperatures, different types of BC could be distinguished, with deeper horizons containing BC of higher thermal stability. Application of combustion residues likely involved a mixture of various BC types, of which thermally more stable ones, most likely soots, were preferentially transported downwards.

Flux, Budget and Sources of Black Carbon (BC) in the Continental Shelf of the Bohai and Yellow Seas, China

NASA Astrophysics Data System (ADS)

Fang, Y.; Chen, Y.; Tian, C.

2015-12-01

Black carbon (BC) derived from incomplete combustion of fossil fuels and biomass has received increasing attention due to their potential importance in a wide range of biogeochemical processes. China has been generally considered as the world's largest BC emitter. Due to a combination of the prevailing East Asia monsoon and large amounts of riverine outflow, BC released from China can be transported to the adjacent continental shelf seas, the Bohai Sea (BS) and Yellow Sea (YS). Based on measurements of BC in 191 surface sediments, 36 riverine water, and 2 seawater samples, as well as the reported BC data set of the aerosol samples in the Bohai Rim, the concentration, flux, and budget of BC in the BS and YS were investigated. The spatial distribution of the BC concentration in surface sediments was largely influenced by the regional hydrodynamic conditions, with high values mainly occurring in the central mud areas. The BC burial flux in the BS and YS ranged from 4 to 1100 μg/cm2/yr, and averaged 166 ± 200 μg/cm2/yr. The area-integrated sedimentary BC sink flux in the entire BS and YS was ~325 Gg/yr. The BC budget calculated in the BS showed that atmospheric deposition and riverine discharge played comparable importance in delivering BC to the BS, and sequestration to bottom sediments was the major BC output pattern, accounting for ~88% of the total input BC. Besides, we attempted to apportion the BC sources in the BS and YS surface sediments using PAHs (organic molecular proxies cogenerated with BC) and BC as an input data to the Positive Matrix Factorization (PMF) receptor model. Results showed that ~83% of the sediment BC was attributed to the combustion of fossil fuels, and the remaining ~17% was from biomass burning. Due to the differences in their production mechanisms and therefore physicochemical properties, the above distinction and quantification would help us better understand their different environmental behaviors in the complex continental shelf regimes.

Factors Affecting Aerosol Radiative Forcing

NASA Astrophysics Data System (ADS)

Wang, Jingxu; Lin, Jintai; Ni, Ruijing

2016-04-01

Rapid industrial and economic growth has meant a large amount of aerosols in the atmosphere with strong radiative forcing (RF) upon the climate system. Over parts of the globe, the negative forcing of aerosols has overcompensated for the positive forcing of greenhouse gases. Aerosol RF is determined by emissions and various chemical-transport-radiative processes in the atmosphere, a multi-factor problem whose individual contributors have not been well quantified. In this study, we analyze the major factors affecting RF of secondary inorganic aerosols (SIOAs, including sulfate, nitrate and ammonium), primary organic aerosol (POA), and black carbon (BC). We analyze the RF of aerosols produced by 11 major regions across the globe, including but not limited to East Asia, Southeast Asia, South Asia, North America, and Western Europe. Factors analyzed include population size, per capita gross domestic production (GDP), emission intensity (i.e., emissions per unit GDP), chemical efficiency (i.e., mass per unit emissions) and radiative efficiency (i.e., RF per unit mass). We find that among the 11 regions, East Asia produces the largest emissions and aerosol RF, due to relatively high emission intensity and a tremendous population size. South Asia produce the second largest RF of SIOA and BC and the highest RF of POA, in part due to its highest chemical efficiency among all regions. Although Southeast Asia also has large emissions, its aerosol RF is alleviated by its lowest chemical efficiency. The chemical efficiency and radiative efficiency of BC produced by the Middle East-North Africa are the highest across the regions, whereas its RF is lowered by a small per capita GDP. Both North America and Western Europe have low emission intensity, compensating for the effects on RF of large population sizes and per capita GDP. There has been a momentum to transfer industries to Southeast Asia and South Asia, and such transition is expected to continue in the coming years. The resulting relocation of emissions would meant drastic changes in both the spatial distribution and the magnitude of RF, with consequences on regional and global climate forcing. Our findings are relevant to global aerosol control and climate mitigation.

Factors Affecting Aerosol Radiative Forcing

NASA Astrophysics Data System (ADS)

Wang, J.; Lin, J.; Ni, R.

2016-12-01

Rapid industrial and economic growth has meant large amount of aerosols in the atmosphere with strong radiative forcing (RF) upon the climate system. Over parts of the globe, the negative forcing of aerosols has overcompensated for the positive forcing of greenhouse gases. Aerosol RF is determined by emissions and various chemical-transport-radiative processes in the atmosphere, a multi-factor problem whose individual contributors have not been well quantified. In this study, we analyze the major factors affecting RF of secondary inorganic aerosols (SIOAs, including sulfate, nitrate and ammonium), primary organic aerosol (POA), and black carbon (BC). We analyze the RFof aerosols produced by 11 major regions across the globe, including but not limited to East Asia, Southeast Asia, South Asia, North America, and Western Europe. Factors analyzed include population size, per capita gross domestic production (GDP), emission intensity (i.e., emissionsper unit GDP), chemical efficiency (i.e., mass per unit emissions) and radiative efficiency (i.e., RF per unit mass). We find that among the 11 regions, East Asia produces the largest emissions and aerosol RF, due to relatively high emission intensity and a tremendous population size.South Asia produce the second largest RF of SIOA and BC and the highest RF of POA, in part due to its highest chemical efficiency among all regions. Although Southeast Asia also has large emissions,its aerosol RF is alleviated by its lowest chemical efficiency.The chemical efficiency and radiative efficiency of BC produced by the Middle East-North Africa are the highest across the regions, whereas its RF is loweredbyasmall per capita GDP.Both North America and Western Europe have low emission intensity, compensating for the effects on RF of large population sizes and per capita GDP. There has been a momentum to transfer industries to Southeast Asia and South Asia, and such transition is expected to continue in the coming years. The resulting relocation of emissions would meant drastic changes in both the spatial distribution and the magnitude of RF, with consequences on regional and global climate forcing. Our findings are relevant to global aerosol control and climate mitigation.

Modeling the Origin of Anthropogenic Black Carbon and Its Climatic Effect Over the Tibetan Plateau and Surrounding Regions

NASA Astrophysics Data System (ADS)

Yang, Junhua; Kang, Shichang; Ji, Zhenming; Chen, Deliang

2018-01-01

Black carbon (BC) in snow/ice induces enhanced snow and glacier melting. As over 60% of atmospheric BC is emitted from anthropogenic sources, which directly impacts the distribution and concentration of BC in snow/ice, it is essential to assess the origin of anthropogenic BC transported to the Tibetan Plateau (TP) where there are few direct emissions attributable to local human activities. In this study, we used a regional climate-atmospheric chemistry model and a set of BC scenarios for quantitative evaluation of the impact of anthropogenic BC from various sources and its climate effects over the TP in 2013. The results showed that the model performed well in terms of climatology, aerosol optical properties, and near-surface concentrations, which indicates that this modeling framework is appropriate to characterize anthropogenic BC source-receptor relationships over the TP. The simulated surface concentration associated with the anthropogenic sources showed seasonal differences. In the monsoon season, the contribution of anthropogenic BC was less than in the nonmonsoon season. In the nonmonsoon season, westerly winds prevailed and transported BC from central Asia and north India to the western TP. In the monsoon season, BC aerosol was transported to the middle-upper troposphere over the Indo-Gangetic Plain and crossed the Himalayas via southwesterly winds. The majority of anthropogenic BC over the TP was transported from South Asia, which contributed to 40%-80% (mean of 61.3%) of surface BC in the nonmonsoon season, and 10%-50% (mean of 19.4%) in the monsoon season. For the northeastern TP, anthropogenic BC from eastern China accounted for less than 10% of the total in the nonmonsoon season but can be up to 50% in the monsoon season. Averaged over the TP, the eastern China anthropogenic sources accounted for 6.2% and 8.4% of surface BC in the nonmonsoon and monsoon seasons, respectively. The anthropogenic BC induced negative radiative forcing and cooling effects at the near surface over the TP.

Plastic scintillator detector for pulsed flux measurements

NASA Astrophysics Data System (ADS)

Kadilin, V. V.; Kaplun, A. A.; Taraskin, A. A.

2017-01-01

A neutron detector, providing charged particle detection capability, has been designed. The main purpose of the detector is to measure pulsed fluxes of both charged particles and neutrons during scientific experiments. The detector consists of commonly used neutron-sensitive ZnS(Ag) / 6LiF scintillator screens wrapping a layer of polystyrene based scintillator (BC-454, EJ-254 or equivalent boron loaded plastic). This type of detector design is able to log a spatial distribution of events and may be scaled to any size. Different variations of the design were considered and modelled in specialized toolkits. The article presents a review of the detector design features as well as simulation results.

Understanding the fate of black (pyrogenic) carbon in soil: Preliminary results from a long term field trial

NASA Astrophysics Data System (ADS)

Meredith, Will; Ascough, Philippa; Bird, Michael; Large, David; Shen, Licheng; Snape, Colin

2014-05-01

Black carbon (BC, also known as pyrogenic carbon) is an 'inert' form of carbon and has been proposed as a means of long-term carbon sequestration, particularly by amending soils and sediments with BC known as biochar. While there is abundant anecdotal evidence of biochar stability over extended timescales it is essential to gain a greater understanding of the degree and mechanisms of biochar degradation in the environment. This study aims to quantitatively assess the stability of biochar by investigating samples from field degradation trials first buried during 2009 in a tropical soil, and recovered after 12 and 36 month intervals. Catalytic hydropyrolysis (HyPy) is a novel analytical tool for the isolation of BC [1] in which high hydrogen pressure (150 bar) and a sulphided Mo catalyst reductively remove the non-BC fraction of the chars, and so isolate the most stable portion of the biochar, defined as BC(HyPy). This method also allows for the non-BC(HyPy) fraction of a sample, which from charcoal is known to include small ring PAHs (<7 rings) of pyrogenic origin to be recovered for molecular characterisation by GC-MS [2]. Biochars made from algae, sugarcane bagasse, and beech wood at 305, 414 and 512°C were emplaced under a variety of conditions allowing variables such as leaf cover, soil depth and pH to be investigated. Char stability (as measured by BC(HyPy) content) is dependent on both the feedstock and temperature of formation. HyPy is known to discriminate (in terms of BC isolation) against low temperature chars, composed of relatively small aromatic clusters [1], resulting in the low BC(HyPy) contents reported for the 305°C chars. Fresh charcoals, and those not subject to environmental degradation have display a similar distribution of aromatic clusters in the non-BC(HyPy) fraction, with 2 to 7 ring PAHs abundant [2]. However, environmentally degraded charcoals such as that from a Chinese river sediment, and an Australian river estuary [3] show a more restricted distribution with markedly fewer 2- and 3- ring PAH structures apparent. This may be evidence for the partial solubilisation of the charcoal as observed for a forest soil [4] and suggested as a mechanism for the transport of BC to the oceans [5], implying that BC cycling could be faster than previously thought [6]. Longer term field trials will be required (analysis of the 36 month samples) to observe systematic changes in the PAH distribution of the non-BCC(HyPy) fractions isolated form aged chars, although natural analogues with a better constrained environmental history may also be useful. [1] Meredith, W. et al., 2012. Geochimica et Cosmochimica Acta 97, 131-147. [2] Ascough, P.L. et al., 2010. Radiocarbon 52, 1336-1350. [3] Lockhart, R.S. et al., 2013. Journal of Analytical and Applied Pyrolysis 104, 640-652. [4] Hockaday, W.C. et al., 2007. Geochimica et Cosmochimica Acta 71, 3432-3445. [5] Jaffe, R. et al., 2013. Science 340, 345-347. [6] Zimmerman, M. et al., 2012. Global Change Biology 18, 3306-3316.

Do Regional Aerosols Contribute to the Riverine Export of Dissolved Black Carbon?

NASA Astrophysics Data System (ADS)

Jones, M. W.; Quine, T. A.; de Rezende, C. E.; Dittmar, T.; Johnson, B.; Manecki, M.; Marques, J. S. J.; de Aragão, L. E. O. C.

2017-11-01

The fate of black carbon (BC), a stable form of thermally altered organic carbon produced during biomass and fuel combustion, remains an area of uncertainty in the global carbon cycle. The transfer of photosynthetically derived BC into extremely long-term oceanic storage is of particular significance and rivers are the key linkage between terrestrial sources and oceanic stores. Significant fluvial fluxes of dissolved BC to oceans result from the slow release of BC from degrading charcoal stocks; however, these fluvial fluxes may also include undetermined contributions of aerosol BC, produced by biomass and fossil fuel combustion, which are deposited in river catchments following atmospheric transport. By investigation of the Paraíba do Sul River catchment in Southeast Brazil we show that aerosol deposits can be substantial contributors to fluvial fluxes of BC. We derived spatial distributions of BC stocks within the catchment associated with soil charcoal and with aerosol from both open biomass burning and fuel combustion. We then modeled the fluvial concentrations of dissolved BC (DBC) in scenarios with varying rates of export from each stock. We analyzed the ability of each scenario to reproduce the variability in DBC concentrations measured in four data sets of river water samples collected between 2010 and 2014 and found that the best performing scenarios included a 5-18% (135-486 Mg DBC year-1) aerosol contribution. Our results suggest that aerosol deposits of BC in river catchments have a shorter residence time in catchments than charcoal BC and, therefore, contribute disproportionately (with respect to stock magnitude) toward fluvial fluxes of BC.

Biophysical Characterization of the Strong Stabilization of the RNA Triplex poly(U)•poly(A)*poly(U) by 9-O-(ω-amino) Alkyl Ether Berberine Analogs

PubMed Central

Hossain, Maidul; Haq, Lucy; Suresh Kumar, Gopinatha

2012-01-01

Background Binding of two 9-O-(ω-amino) alkyl ether berberine analogs BC1 and BC2 to the RNA triplex poly(U)•poly(A)*poly(U) was studied by various biophysical techniques. Methodology/Principal Findings Berberine analogs bind to the RNA triplex non-cooperatively. The affinity of binding was remarkably high by about 5 and 15 times, respectively, for BC1 and BC2 compared to berberine. The site size for the binding was around 4.3 for all. Based on ferrocyanide quenching, fluorescence polarization, quantum yield values and viscosity results a strong intercalative binding of BC1 and BC2 to the RNA triplex has been demonstrated. BC1 and BC2 stabilized the Hoogsteen base paired third strand by about 18.1 and 20.5°C compared to a 17.5°C stabilization by berberine. The binding was entropy driven compared to the enthalpy driven binding of berbeine, most likely due to additional contacts within the grooves of the triplex and disruption of the water structure by the alkyl side chain. Conclusions/Significance Remarkably higher binding affinity and stabilization effect of the RNA triplex by the amino alkyl berberine analogs was achieved compared to berberine. The length of the alkyl side chain influence in the triplex stabilization phenomena. PMID:22666416

Investigating the Vertical Distribution and Source Attribution of Black Carbon over the Pacific Ocean

NASA Astrophysics Data System (ADS)

Zhang, J.; Liu, J.; Ban-Weiss, G. A.; Tao, S.

2014-12-01

Long-range transport of black carbon (BC) aerosols to the Pacific Ocean can potentially play a significant role in changing the marine climate through influences on temperature and cloud profiles and the top-of-atmosphere and surface energy balance. Therefore, quantitatively understanding sources of BC over the Pacific, particularly at different altitudes, is of great importance. In this study, we simulate the transport of thirteen continental BC tracers with a variety of e-folding aging times (few hours to 1 month) using the global chemical transport model MOZART-4. We then optimize BC aging rate according to different source regions by constraining the vertical profile of BC concentrations to the HAIPER Polo-to-Pole Observations (HIPPO). We find that for all HIPPO deployments, a shorter BC aging timescale (less than half day) for tropical and mid-latitude tracers and a longer aging timescale (2-10 days) for high-latitude tracers (except summer) in most cases significantly reduces model biases. By comparing the source-receptor relationship between the optimized BC tracers over the Pacific, we find that during 2009-2011, East Asia contributes most to the BC loading over the Northern Pacific in all seasons except summer, while South American, African and Australian tracers dominate the BC loadings over the Southern Pacific. In addition, unlike other tracers, African BC is a dominant contributor over a larger area in the free troposphere versus the boundary layer. Our findings indicate that the aging rate of BC strongly depends on source location and season, which may significantly influence the contribution of different source regions to BC forcing over the Pacific Ocean.

Evidence that the assembly of the yeast cytochrome bc1 complex involves the formation of a large core structure in the inner mitochondrial membrane.

PubMed

Zara, Vincenzo; Conte, Laura; Trumpower, Bernard L

2009-04-01

The assembly status of the cytochrome bc(1) complex has been analyzed in distinct yeast deletion strains in which genes for one or more of the bc(1) subunits were deleted. In all the yeast strains tested, a bc(1) sub-complex of approximately 500 kDa was found when the mitochondrial membranes were analyzed by blue native electrophoresis. The subsequent molecular characterization of this sub-complex, carried out in the second dimension by SDS/PAGE and immunodecoration, revealed the presence of the two catalytic subunits, cytochrome b and cytochrome c(1), associated with the noncatalytic subunits core protein 1, core protein 2, Qcr7p and Qcr8p. Together, these bc(1) subunits build up the core structure of the cytochrome bc(1) complex, which is then able to sequentially bind the remaining subunits, such as Qcr6p, Qcr9p, the Rieske iron-sulfur protein and Qcr10p. This bc(1) core structure may represent a true assembly intermediate during the maturation of the bc(1) complex; first, because of its wide distribution in distinct yeast deletion strains and, second, for its characteristics of stability, which resemble those of the intact homodimeric bc(1) complex. By contrast, the bc(1) core structure is unable to interact with the cytochrome c oxidase complex to form respiratory supercomplexes. The characterization of this novel core structure of the bc(1) complex provides a number of new elements clarifying the molecular events leading to the maturation of the yeast cytochrome bc(1) complex in the inner mitochondrial membrane.

Evidence that assembly of the yeast cytochrome bc1 complex involves formation of a large core structure in the inner mitochondrial membrane

PubMed Central

Zara, Vincenzo; Conte, Laura; Trumpower, Bernard L.

2009-01-01

The assembly status of the cytochrome bc1 complex has been analyzed in distinct yeast deletion strains in which genes for one or more of the bc1 subunits had been deleted. In all the yeast strains tested a bc1 sub-complex of about 500 kDa was found when the mitochondrial membranes were analyzed by blue native electrophoresis. The subsequent molecular characterization of this sub-complex, carried out in the second dimension by SDS-PAGE and immunodecoration, revealed the presence of the two catalytic subunits cytochrome b and cytochrome c1, associated with the non catalytic subunits core protein 1, core protein 2, Qcr7p and Qcr8p. Altogether these bc1 subunits build up the core structure of the cytochrome bc1 complex which is then able to sequentially bind the remaining subunits, such as Qcr6p, Qcr9p, the Rieske iron-sulfur protein and Qcr10p. This bc1 core structure may represent a true assembly intermediate during the maturation of the bc1 complex, first because of its wide distribution in distinct yeast deletion strains and second for its characteristics of stability which resemble those of the intact homodimeric bc1 complex. Differently from this latter, however, the bc1 core structure is not able to interact with the cytochrome c oxidase complex to form respiratory supercomplexes. The characterization of this novel core structure of the bc1 complex provides a number of new elements for clarification of the molecular events leading to the maturation of the yeast cytochrome bc1 complex in the inner mitochondrial membrane. PMID:19236481

Efficient production of Trastuzumab Fab antibody fragments in Brevibacillus choshinensis expression system.

PubMed

Mizukami, Makoto; Onishi, Hiromasa; Hanagata, Hiroshi; Miyauchi, Akira; Ito, Yuji; Tokunaga, Hiroko; Ishibashi, Matsujiro; Arakawa, Tsutomu; Tokunaga, Masao

2018-10-01

The Brevibacillus expression system has been successfully employed for the efficient productions of a variety of recombinant proteins, including enzymes, cytokines, antigens and antibody fragments. Here, we succeeded in secretory expression of Trastuzumab Fab antibody fragments using B. choshinensis/BIC (Brevibacillus in vivocloning) expression system. In the fed-batch high-density cell culture, recombinant Trastuzumab Fab with amino-terminal His-tag (His-BcFab) was secreted at high level, 1.25 g/liter, and Fab without His-tag (BcFab) at ∼145 mg/L of culture supernatant. His-BcFab and BcFab were purified to homogeneity using combination of conventional column chromatographies with a yield of 10-13%. This BcFab preparation exhibited native structure and functions evaluated by enzyme-linked immunosorbent assay, surface plasmon resonance, circular dichroism measurements and size exclusion chromatography. To our knowledge, this is the highest production of Fab antibody fragments in gram-positive bacterial expression/secretion systems. Copyright © 2018 Elsevier Inc. All rights reserved.

Variation of the radiative properties during black carbon aging: theoretical and experimental intercomparison

DOE PAGES

He, C.; Liou, K.-N.; Takano, Y.; ...

2015-07-20

A theoretical black carbon (BC) aging model is developed to account for three typical evolution stages, namely, freshly emitted aggregates, coated BC by soluble material, and BC particles undergoing further hygroscopic growth. The geometric-optics surface-wave (GOS) approach is employed to compute the BC single-scattering properties at each aging stage, which are subsequently compared with laboratory measurements. Theoretical calculations are consistent with measurements in extinction and absorption cross sections for fresh BC aggregates, but overestimate the scattering cross sections for BC mobility diameters of 155, 245, and 320 nm, because of uncertainties associated with theoretical calculations for small particles as wellmore » as laboratory scattering measurements. The measured optical cross sections for coated BC by sulfuric acid and for those undergoing further hygroscopic growth are captured by theoretical calculations using a concentric core-shell structure, with differences of less than 20 %. This suggests that the core-shell shape represents the realistic BC coating morphology reasonably well in this case, which is consistent with the observed strong structure compaction during aging. We find that the absorption and scattering properties of fresh BC aggregates vary by up to 60 % due to uncertainty in the BC refractive index, which, however, is a factor of two smaller in the case of coated BC particles. Sensitivity analyses on the BC morphology show that the optical properties of fresh BC aggregates are more sensitive to fractal dimension than primary spherule size. The absorption and scattering cross sections of coated BC particles vary by more than a factor of two due to different coating structures. We find an increase of 20–250 % in absorption and a factor of 3–15 in scattering during aging, significantly depending on coating morphology and aging stages. Applying the aging model to CalNex 2010 field measurements, we show that the resulting BC direct radiative forcing (DRF) first increases from 1.5 to 1.7 W m -2 and subsequently decreases to 1.0 W m -2 during the transport from the Los Angeles Basin to downwind regions, as a result of the competition between absorption enhancement due to coating and dilution of BC concentration. The BC DRF can vary by up to a factor of two due to differences in BC coating morphology. Thus, an accurate estimate of BC DRF requires the incorporation of a dynamic BC aging process that accounts for realistic morphology in climate models, particularly for the regional analysis with high atmospheric heterogeneity.« less

Variation of the radiative properties during black carbon aging: theoretical and experimental intercomparison

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, C.; Liou, K.-N.; Takano, Y.

A theoretical black carbon (BC) aging model is developed to account for three typical evolution stages, namely, freshly emitted aggregates, coated BC by soluble material, and BC particles undergoing further hygroscopic growth. The geometric-optics surface-wave (GOS) approach is employed to compute the BC single-scattering properties at each aging stage, which are subsequently compared with laboratory measurements. Theoretical calculations are consistent with measurements in extinction and absorption cross sections for fresh BC aggregates, but overestimate the scattering cross sections for BC mobility diameters of 155, 245, and 320 nm, because of uncertainties associated with theoretical calculations for small particles as wellmore » as laboratory scattering measurements. The measured optical cross sections for coated BC by sulfuric acid and for those undergoing further hygroscopic growth are captured by theoretical calculations using a concentric core-shell structure, with differences of less than 20 %. This suggests that the core-shell shape represents the realistic BC coating morphology reasonably well in this case, which is consistent with the observed strong structure compaction during aging. We find that the absorption and scattering properties of fresh BC aggregates vary by up to 60 % due to uncertainty in the BC refractive index, which, however, is a factor of two smaller in the case of coated BC particles. Sensitivity analyses on the BC morphology show that the optical properties of fresh BC aggregates are more sensitive to fractal dimension than primary spherule size. The absorption and scattering cross sections of coated BC particles vary by more than a factor of two due to different coating structures. We find an increase of 20–250 % in absorption and a factor of 3–15 in scattering during aging, significantly depending on coating morphology and aging stages. Applying the aging model to CalNex 2010 field measurements, we show that the resulting BC direct radiative forcing (DRF) first increases from 1.5 to 1.7 W m -2 and subsequently decreases to 1.0 W m -2 during the transport from the Los Angeles Basin to downwind regions, as a result of the competition between absorption enhancement due to coating and dilution of BC concentration. The BC DRF can vary by up to a factor of two due to differences in BC coating morphology. Thus, an accurate estimate of BC DRF requires the incorporation of a dynamic BC aging process that accounts for realistic morphology in climate models, particularly for the regional analysis with high atmospheric heterogeneity.« less

Determination of PM mass emissions from an aircraft turbine engine using particle effective density

NASA Astrophysics Data System (ADS)

Durdina, L.; Brem, B. T.; Abegglen, M.; Lobo, P.; Rindlisbacher, T.; Thomson, K. A.; Smallwood, G. J.; Hagen, D. E.; Sierau, B.; Wang, J.

2014-12-01

Inventories of particulate matter (PM) emissions from civil aviation and air quality models need to be validated using up-to-date measurement data corrected for sampling artifacts. We compared the measured black carbon (BC) mass and the total PM mass determined from particle size distributions (PSD) and effective density for a commercial turbofan engine CFM56-7B26/3. The effective density was then used to calculate the PM mass losses in the sampling system. The effective density was determined using a differential mobility analyzer and a centrifugal particle mass analyzer, and increased from engine idle to take-off by up to 60%. The determined mass-mobility exponents ranged from 2.37 to 2.64. The mean effective density determined by weighting the effective density distributions by PM volume was within 10% of the unit density (1000 kg/m3) that is widely assumed in aircraft PM studies. We found ratios close to unity between the PM mass determined by the integrated PSD method and the real-time BC mass measurements. The integrated PSD method achieved higher precision at ultra-low PM concentrations at which current mass instruments reach their detection limit. The line loss model predicted ∼60% PM mass loss at engine idle, decreasing to ∼27% at high thrust. Replacing the effective density distributions with unit density lead to comparable estimates that were within 20% and 5% at engine idle and high thrust, respectively. These results could be used for the development of a robust method for sampling loss correction of the future PM emissions database from commercial aircraft engines.

Uptake mechanism for iodine species to black carbon.

PubMed

Choung, Sungwook; Um, Wooyong; Kim, Minkyung; Kim, Min-Gyu

2013-09-17

Natural organic matter (NOM) plays an important role in determining the fate and transport of iodine species such as iodide (I(-)) and iodate (IO3(-)) in groundwater system. Although NOM exists as diverse forms in environments, prior iodine studies have mainly focused on uptake processes of iodide and iodate to humic materials. This study was conducted to determine the iodide and iodate uptake potential for a particulate NOM (i.e., black carbon [BC]). A laboratory-produced BC and commercial humic acid were used for batch experiments to compare their iodine uptake properties. The BC exhibited >100 times greater uptake capability for iodide than iodate at low pH of ~3, while iodide uptake was negligible for the humic acid. The uptake properties of both solids strongly depend on the initial iodine aqueous concentrations. After uptake reaction of iodide to the BC, X-ray absorption fine structure spectroscopy results indicated that the iodide was converted to electrophilic species, and iodine was covalently bound to carbon atom in polycyclic aromatic hydrocarbons present in the BC. The computed distribution coefficients (i.e., Kd values) suggest that the BC materials retard significantly the transport of iodide at low pH in environmental systems containing even a small amount of BC.

Aerosol physical and chemical properties retrieved from ground-based remote sensing measurements during heavy haze days in Beijing winter

NASA Astrophysics Data System (ADS)

Li, Z.; Gu, X.; Wang, L.; Li, D.; Xie, Y.; Li, K.; Dubovik, O.; Schuster, G.; Goloub, P.; Zhang, Y.; Li, L.; Ma, Y.; Xu, H.

2013-10-01

With the increase in economic development over the past thirty years, many large cities in eastern and southwestern China are experiencing increased haze events and atmospheric pollution, causing significant impacts on the regional environment and even climate. However, knowledge on the aerosol physical and chemical properties in heavy haze conditions is still insufficient. In this study, two winter heavy haze events in Beijing that occurred in 2011 and 2012 were selected and investigated by using the ground-based remote sensing measurements. We used a CIMEL CE318 sun-sky radiometer to retrieve haze aerosol optical, physical and chemical properties, including aerosol optical depth (AOD), size distribution, complex refractive indices and aerosol fractions identified as black carbon (BC), brown carbon (BrC), mineral dust (DU), ammonium sulfate-like (AS) components and aerosol water content (AW). The retrieval results from a total of five haze days showed that the aerosol loading and properties during the two winter haze events were comparable. Therefore, average heavy haze property parameters were drawn to present a research case for future studies. The average AOD is about 3.0 at 440 nm, and the Ångström exponent is 1.3 from 440 to 870 nm. The fine-mode AOD is 2.8 corresponding to a fine-mode fraction of 0.93. The coarse particles occupied a considerable volume fraction of the bimodal size distribution in winter haze events, with the mean particle radius of 0.21 and 2.9 μm for the fine and coarse modes respectively. The real part of the refractive indices exhibited a relatively flat spectral behavior with an average value of 1.48 from 440 to 1020 nm. The imaginary part showed spectral variation, with the value at 440 nm (about 0.013) higher than the other three wavelengths (about 0.008 at 675 nm). The aerosol composition retrieval results showed that volume fractions of BC, BrC, DU, AS and AW are 1, 2, 49, 15 and 33%, respectively, on average for the investigated haze events. The preliminary uncertainty estimation and comparison of these remote sensing results with in situ BC and PM2.5 measurements are also presented in the paper.

Biomass burning emissions of trace gases and particles in marine air at Cape Grim, Tasmania, 41° S

NASA Astrophysics Data System (ADS)

Lawson, S. J.; Keywood, M. D.; Galbally, I. E.; Gras, J. L.; Cainey, J. M.; Cope, M. E.; Krummel, P. B.; Fraser, P. J.; Steele, L. P.; Bentley, S. T.; Meyer, C. P.; Ristovski, Z.; Goldstein, A. H.

2015-07-01

Biomass burning (BB) plumes were measured at the Cape Grim Baseline Air Pollution Station during the 2006 Precursors to Particles campaign, when emissions from a fire on nearby Robbins Island impacted the station. Measurements made included non methane organic compounds (NMOCs) (PTR-MS), particle number size distribution, condensation nuclei (CN) > 3 nm, black carbon (BC) concentration, cloud condensation nuclei (CCN) number, ozone (O3), methane (CH4), carbon monixide (CO), hydrogen (H2), carbon dioxide (CO2), nitrous oxide (N2O), halocarbons and meteorology. During the first plume strike event (BB1), a four hour enhancement of CO (max ~ 2100 ppb), BC (~ 1400 ng m-3) and particles > 3 nm (~ 13 000 cm-3) with dominant particle mode of 120 nm were observed overnight. Dilution of the plume resulted in a drop in the dominant particle mode to 50 nm, and then growth to 80 nm over 5 h. This was accompanied by an increase in O3, suggesting that photochemical processing of air and condensation of low volatility oxidation products may be driving particle growth. The ability of particles > 80 nm (CN80) to act as CCN at 0.5 % supersaturation was investigated. The ΔCCN / ΔCN80 ratio was lowest during the fresh BB plume (56 %), higher during the particle growth event (77 %) and higher still (104 %) in background marine air. Particle size distributions indicate that changes to particle chemical composition, rather than particle size, are driving these changes. Hourly average CCN during both BB events were between 2000-5000 CCN cm-3, which were enhanced above typical background levels by a factor of 6-34, highlighting the dramatic impact BB plumes can have on CCN number in clean marine regions. During the 29 h of the second plume strike event (BB2) CO, BC and a range of NMOCs including acetonitrile and hydrogen cyanide (HCN) were clearly enhanced and some enhancements in O3 were observed (ΔO3 / ΔCO 0.001-0.074). A shortlived increase in NMOCs by a factor of 10 corresponded with a large CO enhancement, an increase of the NMOC / CO emission ratio (ER) by a factor of 2-4 and a halving of the BC / CO ratio. Rainfall on Robbins Island was observed by radar during this period which likely resulted in a lower fire combustion efficiency, and higher emission of compounds associated with smouldering. This highlights the importance of relatively minor meterological events on BB emissions. Emission factors (EF) were derived for a range of trace gases, some never before reported for Australian conditions, (including hydrogen, phenol and toluene) using a calculated ER to CO and a published CO EF. The EF derived for most species are comparable to other temperate Australian studies but lower than Northern Hemisphere temperate studies. This work demonstrates the substantial impact that BB plumes have on the composition of marine air, and the significant changes that can occur as the plume is diluted and interacts with other emission sources. We also provide new trace gas and particle EF for temperate southern Australia.

Enhanced production of bacterial cellulose by using a biofilm reactor and its material property analysis

PubMed Central

Cheng, Kuan-Chen; Catchmark, Jeff M; Demirci, Ali

2009-01-01

Bacterial cellulose has been used in the food industry for applications such as low-calorie desserts, salads, and fabricated foods. It has also been used in the paper manufacturing industry to enhance paper strength, the electronics industry in acoustic diaphragms for audio speakers, the pharmaceutical industry as filtration membranes, and in the medical field as wound dressing and artificial skin material. In this study, different types of plastic composite support (PCS) were implemented separately within a fermentation medium in order to enhance bacterial cellulose (BC) production by Acetobacter xylinum. The optimal composition of nutritious compounds in PCS was chosen based on the amount of BC produced. The selected PCS was implemented within a bioreactor to examine the effects on BC production in a batch fermentation. The produced BC was analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA). Among thirteen types of PCS, the type SFYR+ was selected as solid support for BC production by A. xylinum in a batch biofilm reactor due to its high nitrogen content, moderate nitrogen leaching rate, and sufficient biomass attached on PCS. The PCS biofilm reactor yielded BC production (7.05 g/L) that was 2.5-fold greater than the control (2.82 g/L). The XRD results indicated that the PCS-grown BC exhibited higher crystallinity (93%) and similar crystal size (5.2 nm) to the control. FESEM results showed the attachment of A. xylinum on PCS, producing an interweaving BC product. TGA results demonstrated that PCS-grown BC had about 95% water retention ability, which was lower than BC produced within suspended-cell reactor. PCS-grown BC also exhibited higher Tmax compared to the control. Finally, DMA results showed that BC from the PCS biofilm reactor increased its mechanical property values, i.e., stress at break and Young's modulus when compared to the control BC. The results clearly demonstrated that implementation of PCS within agitated fermentation enhanced BC production and improved its mechanical properties and thermal stability. PMID:19630969

Novel Piezoelectric Paper‐Based Flexible Nanogenerators Composed of BaTiO3 Nanoparticles and Bacterial Cellulose

PubMed Central

Zhang, Guangjie; Liao, Qingliang; Zhang, Zheng; Liang, Qijie; Zhao, Yingli; Zheng, Xin

2015-01-01

A piezoelectric paper based on BaTiO3 (BTO) nanoparticles and bacterial cellulose (BC) with excellent output properties for application of nanogenerators (NGs) is reported. A facile and scalable vacuum filtration method is used to fabricate the piezoelectric paper. The BTO/BC piezoelectric paper based NG shows outstanding output performance with open‐circuit voltage of 14 V and short‐circuit current density of 190 nA cm−2. The maximum power density generated by this unique BTO/BC structure is more than ten times higher than BTO/polydimethylsiloxane structure. In bending conditions, the NG device can generate output voltage of 1.5 V, which is capable of driving a liquid crystal display screen. The improved performance can be ascribed to homogeneous distribution of piezoelectric BTO nanoparticles in the BC matrix as well as the enhanced stress on piezoelectric nanoparticles implemented by the unique percolated networks of BC nanofibers. The flexible BTO/BC piezoelectric paper based NG is lightweight, eco‐friendly, and cost‐effective, which holds great promises for achieving wearable or implantable energy harvesters and self‐powered electronics. PMID:27774389

Nanocellulose based asymmetric composite membrane for the multiple functions in cell encapsulation.

PubMed

Park, Minsung; Shin, Sungchul; Cheng, Jie; Hyun, Jinho

2017-02-20

We describe the nanocomposite membrane for cell encapsulation using nanocelluose hydrogels. One of the surfaces of bacterial cellulose (BC) pellicles was coated with collagen to enhance cell adhesion and the opposite side of the BC pellicles was coated with alginate to protect transplanted cells from immune rejection by the reduced pore size of the composite membrane. The morphology of nanocomposite membrane was observed by scanning electron microscopy and the permeability of the membrane was estimated by the release test using different molecular weights of polymer solution. The nanocomposite membrane was permeable to small molecules but impermeable to large molecules such as IgG antibodies inferring the potential use in cell implantation. In addition, the BC-based nanocomposite membrane showed a superior mechanical property due to the incorporation of compared with alginate membranes. The cells attached efficiently to the surface of BC composite membranes with a high level of cell viability as well as bioactivity. Cells grown on the BC composite membrane kit released dopamine freely to the medium through the membrane, which showed that the BC composite membrane would be a promising cell encapsulation material in implantation. Copyright © 2016 Elsevier Ltd. All rights reserved.

XRD and solid state 13C-NMR evaluation of the crystallinity enhancement of 13C-labeled bacterial cellulose biosynthesized by Komagataeibacter xylinus under different stimuli: A comparative strategy of analyses.

PubMed

Meza-Contreras, Juan C; Manriquez-Gonzalez, Ricardo; Gutiérrez-Ortega, José A; Gonzalez-Garcia, Yolanda

2018-05-22

The production and crystallinity of 13 C bacterial cellulose (BC) was examined in static culture of Komagataeibacter xylinus with different chemical and physical stimuli: the addition of NaCl or cloramphenicol as well as exposure to a magnetic field or to UV light. Crystalline BC biosynthesized under each stimulus was studied by XRD and solid state 13 C NMR analyses. All treatments produced BC with enhanced crystallinity over 90% (XRD) and 80% (NMR) compared to the control (83 and 76%, respectively) or to Avicel (77 and 62%, respectively). The XRD data indicated that the crystallite size was 80-85 Å. Furthermore, changes on the allomorphs (I α and I β ) ratio tendency of BC samples addressed to the stimuli were estimated using the C4 signal from 13 C NMR data. These results showed a decrease of the allomorph I α (3%) when BC was biosynthesized with UV light and chloramphenicol compared to control (58.79%). In contrast, the BC obtained with NaCl increased up to 60.31% of the I α allomorph ratio. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characterization of Cyt2Bc Toxin from Bacillus thuringiensis subsp. medellin

PubMed Central

Juárez-Pérez, Victor; Guerchicoff, Alejandra; Rubinstein, Clara; Delécluse, Armelle

2002-01-01

We cloned and sequenced a new cytolysin gene from Bacillus thuringiensis subsp. medellin. Three IS240-like insertion sequence elements and the previously cloned cyt1Ab and p21 genes were found in the vicinity of the cytolysin gene. The cytolysin gene encodes a protein 29.7 kDa in size that is 91.5% identical to Cyt2Ba from Bacillus thuringiensis subsp. israelensis and has been designated Cyt2Bc. Inclusions containing Cyt2Bc were purified from the crystal-negative strain SPL407 of B. thuringiensis. Cyt2Bc reacted weakly with antibodies directed against Cyt2Ba and was not recognized by an antiserum directed against the reference cytolysin Cyt1Aa. Cyt2Bc was hemolytic only upon activation with trypsin and had only one-third to one-fifth of the activity of Cyt2Ba, depending on the activation time. Cyt2Bc was also mosquitocidal against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus, including strains resistant to the Bacillus sphaericus binary toxin. Its toxicity was half of that of Cyt2Ba on all mosquito species except resistant C. quinquefasciatus. PMID:11872472

Glucose and lipoprotein biomarkers and breast cancer severity using data from the Swedish AMORIS cohort.

PubMed

Melvin, Jennifer C; Garmo, Hans; Holmberg, Lars; Hammar, Niklas; Walldius, Göran; Jungner, Ingmar; Lambe, Mats; Van Hemelrijck, Mieke

2017-04-04

The lipid and glucose metabolisms are postulated as possible intermediary mechanisms in linking obesity and breast cancer (BC). Links between serum lipid and glucose biomarkers and BC risk has been observed in the Swedish Apolipoprotein MORtality RISk (AMORIS) cohort. We conducted a follow-up analysis including information on tumour characteristics. One thousand eight hundred twenty-four women diagnosed with BC, with serum biomarker levels of glucose, triglycerides, cholesterol (total, HDL, and LDL), and apolipoproteins A-1 and B recorded in a routine health check at baseline were included. BC severity was split into categories (good, moderate, and poor prognosis) based on ER status, TNM stage, and age at diagnosis. Proportional odds models were used to obtain odds ratios (ORs) and 95% confidence intervals (CI), with the interval time between baseline measurement and BC diagnosis accounted for. Serum glucose and the ApoB/ApoA-1 ratio showed a non-statistically significant positive association with BC severity (proportional OR: 1.25 (95%CI: 0.92-1.70) for glucose (

Black carbon mixing state impacts on cloud microphysical properties: effects of aerosol plume and environmental conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ching, Ping Pui; Riemer, Nicole; West, Matthew

2016-05-27

Black carbon (BC) is usually mixed with other aerosol species within individual aerosol particles. This mixture, along with the particles' size and morphology, determines the particles' optical and cloud condensation nuclei properties, and hence black carbon's climate impacts. In this study the particle-resolved aerosol model PartMC-MOSAIC was used to quantify the importance of black carbon mixing state for predicting cloud microphysical quantities. Based on a set of about 100 cloud parcel simulations a process level analysis framework was developed to attribute the response in cloud microphysical properties to changes in the underlying aerosol population ("plume effect") and the cloud parcelmore » cooling rate ("parcel effect"). It shows that the response of cloud droplet number concentration to changes in BC emissions depends on the BC mixing state. When the aerosol population contains mainly aged BC particles an increase in BC emission results in increasing cloud droplet number concentrations ("additive effect"). In contrast, when the aerosol population contains mainly fresh BC particles they act as sinks for condensable gaseous species, resulting in a decrease in cloud droplet number concentration as BC emissions are increased ("competition effect"). Additionally, we quantified the error in cloud microphysical quantities when neglecting the information on BC mixing state, which is often done in aerosol models. The errors ranged from -12% to +45% for the cloud droplet number fraction, from 0% to +1022% for the nucleation-scavenged black carbon (BC) mass fraction, from -12% to +4% for the effective radius, and from -30% to +60% for the relative dispersion.« less

Roosevelt Island Climate Evolution Project (RICE): A 65 Kyr ice core record of black carbon aerosol deposition to the Ross Ice Shelf, West Antarctica.

NASA Astrophysics Data System (ADS)

Edwards, Ross; Bertler, Nancy; Tuohy, Andrea; Neff, Peter; Proemse, Bernedette; Feiteng, Wang; Goodwin, Ian; Hogan, Chad

2015-04-01

Emitted by fires, black carbon aerosols (rBC) perturb the atmosphere's physical and chemical properties and are climatically active. Sedimentary charcoal and other paleo-fire records suggest that rBC emissions have varied significantly in the past due to human activity and climate variability. However, few paleo rBC records exist to constrain reconstructions of the past rBC atmospheric distribution and its climate interaction. As part of the international Roosevelt Island Climate Evolution (RICE) project, we have developed an Antarctic rBC ice core record spanning the past ~65 Kyr. The RICE deep ice core was drilled from the Roosevelt Island ice dome in West Antarctica from 2011 to 2013. The high depth resolution (~ 1 cm) record was developed using a single particle intracavity laser-induced incandescence soot photometer (SP2) coupled to an ice core melter system. The rBC record displays sub-annual variability consistent with both austral dry-season and summer biomass burning. The record exhibits significant decadal to millennial-scale variability consistent with known changes in climate. Glacial rBC concentrations were much lower than Holocene concentrations with the exception of several periods of abrupt increases in rBC. The transition from glacial to interglacial rBC concentrations occurred over a much longer time relative to other ice core climate proxies such as water isotopes and suggests . The protracted increase in rBC during the transition may reflected Southern hemisphere ecosystem / fire regime changes in response to hydroclimate and human activity.

Atmospheric Sampling of Aerosols to Stratospheric Altitudes using High Altitude Balloons

NASA Astrophysics Data System (ADS)

Jerde, E. A.; Thomas, E.

2010-12-01

Although carbon dioxide represents a long-lived atmospheric component relevant to global climate change, it is also understood that many additional contributors influence the overall climate of Earth. Among these, short-lived components are more difficult to incorporate into models due to uncertainties in the abundances of these both spatially and temporally. Possibly the most significant of these short-lived components falls under the heading of “black carbon” (BC). There are numerous overlapping definitions of BC, but it is basically carbonaceous in nature and light absorbing. Due to its potential as a climate forcer, an understanding of the BC population in the atmosphere is critical for modeling of radiative forcing. Prior measurements of atmospheric BC generally consist of airplane- and ground-based sampling, typically below 5000 m and restricted in time and space. Given that BC has a residence time on the order of days, short-term variability is easily missed. Further, since the radiative forcing is a result of BC distributed through the entire atmospheric column, aircraft sampling is by definition incomplete. We are in the process of planning a more comprehensive sampling of the atmosphere for BC using high-altitude balloons. Balloon-borne sampling is a highly reliable means to sample air through the entire troposphere and into the lower stratosphere. Our system will incorporate a balloon and a flight train of two modules. One module will house an atmospheric sampler. This sampler will be single-stage (samples all particle sizes together), and will place particles directly on an SEM sample stub for analysis. The nozzle depositing the sample will be offset from the center of the stub, placing the aerosol particles toward the edge. At various altitudes, the stub will be rotated 45 degrees, providing 6-8 sample “cuts” of particle populations through the atmospheric column. The flights will reach approximately 27 km altitude, above which the balloons burst and the modules return to the surface. The second module will contain instrumentation recording temperature, pressure, and humidity, plus a radio beacon to track the location, facilitating recovery. Another instrument we are planning is a small, lightweight optical aerosol spectrometer probe. This would provide a valuable secondary set of data to compare with the actual sampling. The aerosol particle population will be assessed using the SEM at Morehead State University. Over the next several years, sampling is planned at locations both near and far from urban areas, and at intermediate locations. Sampling will be conducted at four times during the year to assess seasonal variations and, at some sites, repeated short-term samplings (e.g., 5 flights in 10 days) will be undertaken to assess short-term variations. In addition, the SEM should permit the assessment of the ratio of BC to organic carbon (OC). Like BC, organic carbon species are produced through biomass burning, but are not as effective as light absorbers, so are not responsible for as much forcing as black carbon. The atmosphere is sampled at a known volumetric rate, resulting in a picture of the atmospheric column density for both BC and OC, information of great use in modeling of the aerosol contribution to climate change.

Short-Range-Order Mineral Physical Protection On Black Carbon Stabilization

NASA Astrophysics Data System (ADS)

Liang, B.; Weng, Y. T.; Wang, C. C.; Song, Y. F.; Lehmann, J.; Wang, C. H.

2015-12-01

Soil organic matter is one of the largest reservoirs in global carbon cycle, and black carbon (BC) represents a chemical resistant component. Black C plays an important role in global climate change. Generally considered recalcitrant due to high aromaticity, the reactive surface and functional groups of BC are crucial for carbon sequestration in soils. Mineral sorption and physical protection is an important mechanism for BC long term stabilization and sequestration in environments. Previous studies on mineral protection of BC were limited to analysis techniques in two-dimensions, for example, by SEM, TEM, and NanoSIMS. Little is known about the scope of organo-mineral association, the in-situ distribution and forms of minerals, and the ultimate interplay of BC and minerals. The aim of this study is to investigate the three-dimensional interaction of organic C and minerals in submicron scale using synchrotron-based Transmission X-ray Microcopy (TXM) and Fourier-Transform Infrared Spectroscopy (FTIR). Abundant poorly-crystallined nano-minerals particles were observed. These short-range-order (SRO) minerals also aggregate into clusters and sheets, and form envelops-like structures on the surface of BC. On top of large surface contact area, the intimate interplay between BC and minerals reinforces the stability of both organic C and minerals, resulting from chemical bonding through cation bridging and ligand exchange. The mineral protection enhances BC stabilization and sequestration and lowers its bioavailability in environment. The results suggest that mineral physical protection for BC sequestration may be more important than previous understanding.

A study on the relationship between mass concentrations, chemistry and number size distribution of urban fine aerosols in Milan, Barcelona and London

NASA Astrophysics Data System (ADS)

Rodríguez, S.; van Dingenen, R.; Putaud, J.-P.; Dell'Acqua, A.; Pey, J.; Querol, X.; Alastuey, A.; Chenery, S.; Ho, K.-F.; Harrison, R. M.; Tardivo, R.; Scarnato, B.; Gianelle, V.

2007-01-01

A physicochemical characterization of the urban fine aerosol (aerosol number size distribution, chemical composition and mass concentrations) in Milan, Barcelona and London is presented in this article. The objective is to obtain a comprehensive picture on the involvement of the microphysical processes of the aerosol dynamic in the: 1) regular evolution of the urban aerosol (daily, weekly and seasonal basis) and in the day-to-day variations (from clean-air to pollution-events), and 2) link between "aerosol chemistry and mass concentrations" with the "number size distribution". The mass concentrations of the fine PM2.5 aerosol exhibit a high correlation with the number concentration of particles >100 nm (which only accounts for <20% of the total number concentration N of fine aerosols) and do not correlate with the number of particles <100 nm ("ultrafine particles", which accounts for >80% of fine particles). Organic matter (OM) and black-carbon (BC) are the only aerosol components showing a significant correlation with ultrafine particles (attributed to vehicles emissions), whereas ammonium-nitrate, ammonium-sulphate and also OM and BC correlate with N>100(nm) (attributed to gas-to-particle transformation mechanisms and some primary emissions). Time series of the aerosol DpN diameter (dN/dlogD mode), mass PM2.5 concentrations and number N>100(nm) concentrations, exhibit correlated day-to-day variations which point to a significant involvement of condensation of semi-volatile compounds during urban pollution events. This agrees with the fact that ammonium-nitrate is the component exhibiting the highest increases from mid-to-high pollution episodes, when the highest DpN increases are observed. The results indicates that "fine PM2.5 particles urban pollution events" tend to occur when condensation processes have made particles grow enough to produce significant concentrations of N>100(nm). In contrast, because the low contribution of ultrafine particles to the fine aerosol mass concentrations, high "ultrafine particles N<100(nm) events" frequently occurs under low PM2.5 conditions. The data of this study point that vehicles emissions are strongly involved in this ultrafine particles aerosol pollution (for example, the "morning-rush-hours to nocturnal-background" concentrations ratio is 1.5-2.5 for "particles 10-100 nm" and <1.5 for both "particle >100 nm and PM2.5").

Camptothecin prodrug nanomicelle based on a boronate ester-linked diblock copolymer as the carrier of doxorubicin with enhanced cellular uptake.

PubMed

Gao, Ya; Xiao, Yi; Liu, Shiyuan; Yu, Jiahui

2018-02-01

A novel pH-sensitive polymeric prodrug of camptothecin (CPT) by polymerizing γ-camptothecin-glutamate N-carboxyanhydride (Glu (CPT)-NCA) on boronate ester-linked poly (ethyleneglycol) (PEG) directly via the amine-initiated ring open polymerization (ROP) has been developed. The resulting amphiphilic prodrug (mPEG-BC-PGluCPT) could self-assemble into nanoparticles and encapsulate doxorubicin (Dox) simultaneously in aqueous solution for dual-drug delivery. The formation of polymeric prodrug micelles (mPEG-BC@PGluCPT) was confirmed by the measurements of critical aggregation concentration (CAC), particle size, and morphology observations. The mPEG-BC@PGluCPT micelles were colloidally stable in solutions for two weeks. Polymeric prodrug micelles mPEG-BC@PGluCPT and Dox-loaded micelles mPEG-BC@PGluCPT⋅Dox showed sustained drug release profiles over 48 h. As expected, drug release was accelerated by the decreasement of pH value from 7.4 to 6.0, which demonstrated pH-dependent manner of drug release. Additionally, it was found that cellular uptake of mPEG-BC@PGluCPT⋅Dox micelles on HepG2 cells was higher than that on HL-7702 cells, especially in culture medium at pH 6.0. The enhanced cellular uptake of mPEG-BC@PGluCPT⋅Dox micelles under acidic condition on HepG2 cells resulted in the higher cytotoxicity of mPEG-BC@PGluCPT⋅Dox micelles at acidic pH than that at pH 7.4.

Using an Explicit Emission Tagging Method in Global Modeling of Source-Receptor Relationships for Black Carbon in the Arctic: Variations, Sources and Transport Pathways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hailong; Rasch, Philip J.; Easter, Richard C.

2014-11-27

We introduce an explicit emission tagging technique in the Community Atmosphere Model to quantify source-region-resolved characteristics of black carbon (BC), focusing on the Arctic. Explicit tagging of BC source regions without perturbing the emissions makes it straightforward to establish source-receptor relationships and transport pathways, providing a physically consistent and computationally efficient approach to produce a detailed characterization of the destiny of regional BC emissions and the potential for mitigation actions. Our analysis shows that the contributions of major source regions to the global BC burden are not proportional to the respective emissions due to strong region-dependent removal rates and lifetimes,more » while the contributions to BC direct radiative forcing show a near-linear dependence on their respective contributions to the burden. Distant sources contribute to BC in remote regions mostly in the mid- and upper troposphere, having much less impact on lower-level concentrations (and deposition) than on burden. Arctic BC concentrations, deposition and source contributions all have strong seasonal variations. Eastern Asia contributes the most to the wintertime Arctic burden. Northern Europe emissions are more important to both surface concentration and deposition in winter than in summer. The largest contribution to Arctic BC in the summer is from Northern Asia. Although local emissions contribute less than 10% to the annual mean BC burden and deposition within the Arctic, the per-emission efficiency is much higher than for major non-Arctic sources. The interannual variability (1996-2005) due to meteorology is small in annual mean BC burden and radiative forcing but is significant in yearly seasonal means over the Arctic. When a slow aging treatment of BC is introduced, the increase of BC lifetime and burden is source-dependent. Global BC forcing-per-burden efficiency also increases primarily due to changes in BC vertical distributions. The relative contribution from major non-Arctic sources to the Arctic BC burden increases only slightly, although the contribution of Arctic local sources is reduced by a factor of 2 due to the slow aging treatment.« less

[Genetic subtype and epidemiological feature of HIV-1 circulating strains among recently infected patients in Fujian province].

PubMed

Deng, Yongyue; Zhang, Chunyang; Yan, Yansheng; Yan, Pingping; Wu, Shouli

2014-06-01

In order to evaluate the distribution of genetic subtypes and epidemiological feature of HIV-1 circulating strains in Fujian province. Blood samples and epidemiological data were collected from 104 newly infected patients who were distinguished by BED-CEIA methodology, during 2011-2012. Viral sequences(n = 81) of HIV-1 gag, env, and pol segments were amplified by nested PCR. Subtypes B and four Circulating Recombinant Forms, (CRF01_AE, CRF07_BC, CRF08_BC and CRF55_01B) were found in the samples, CRF01_AE(45.68%)and CRF07_BC(35.80%) were the two main HIV-1 strains in Fujian province. Compared with previous data, the proportion of CRF07_BC rose significantly while it gradually decreased in CRF01_AE. Heterosexual contact was still the principal transmission route in Fujian province, but the number of infection among men-who-have-sex-with- men grew rapidly. Results from this study suggested that different subtypes of HIV-1 strain existed in Fujian province. The distribution of subtypes and the mode of transmission were changing with the progress of epidemic. Dynamic monitoring of the molecular epidemiology trends of HIV-1 infection should be enhanced.

Estimates of spatially and temporally resolved constrained black carbon emission over the Indian region using a strategic integrated modelling approach

NASA Astrophysics Data System (ADS)

Verma, S.; Reddy, D. Manigopal; Ghosh, S.; Kumar, D. Bharath; Chowdhury, A. Kundu

2017-10-01

We estimated the latest spatially and temporally resolved gridded constrained black carbon (BC) emissions over the Indian region using a strategic integrated modelling approach. This was done extracting information on initial bottom-up emissions and atmospheric BC concentration from a general circulation model (GCM) simulation in conjunction with the receptor modelling approach. Monthly BC emission (83-364 Gg) obtained from the present study exhibited a spatial and temporal variability with this being the highest (lowest) during February (July). Monthly BC emission flux was considerably high (> 100 kg km- 2) over the entire Indo-Gangetic plain (IGP), east and the west coast during winter months. This was relatively higher over the central and western India than over the IGP during summer months. Annual BC emission rate was 2534 Gg y- 1 with that over the IGP and central India respectively comprising 50% and 40% of the total annual BC emissions over India. A high relative increase was observed in modified BC emissions (more than five times the initial emissions) over the most part of the IGP, east coast, central/northwestern India. The relative predominance of monthly BC emission flux over a region (as depicted from z-score distribution maps) was inferred being consistent with the prevalence of region- and season-specific anthropogenic activity.

Evaluation of black carbon estimations in global aerosol models

NASA Astrophysics Data System (ADS)

Koch, D.; Schulz, M.; Kinne, S.; McNaughton, C.; Spackman, J. R.; Balkanski, Y.; Bauer, S.; Berntsen, T.; Bond, T. C.; Boucher, O.; Chin, M.; Clarke, A.; de Luca, N.; Dentener, F.; Diehl, T.; Dubovik, O.; Easter, R.; Fahey, D. W.; Feichter, J.; Fillmore, D.; Freitag, S.; Ghan, S.; Ginoux, P.; Gong, S.; Horowitz, L.; Iversen, T.; Kirkevåg, A.; Klimont, Z.; Kondo, Y.; Krol, M.; Liu, X.; Miller, R.; Montanaro, V.; Moteki, N.; Myhre, G.; Penner, J. E.; Perlwitz, J.; Pitari, G.; Reddy, S.; Sahu, L.; Sakamoto, H.; Schuster, G.; Schwarz, J. P.; Seland, Ø.; Stier, P.; Takegawa, N.; Takemura, T.; Textor, C.; van Aardenne, J. A.; Zhao, Y.

2009-11-01

We evaluate black carbon (BC) model predictions from the AeroCom model intercomparison project by considering the diversity among year 2000 model simulations and comparing model predictions with available measurements. These model-measurement intercomparisons include BC surface and aircraft concentrations, aerosol absorption optical depth (AAOD) retrievals from AERONET and Ozone Monitoring Instrument (OMI) and BC column estimations based on AERONET. In regions other than Asia, most models are biased high compared to surface concentration measurements. However compared with (column) AAOD or BC burden retreivals, the models are generally biased low. The average ratio of model to retrieved AAOD is less than 0.7 in South American and 0.6 in African biomass burning regions; both of these regions lack surface concentration measurements. In Asia the average model to observed ratio is 0.7 for AAOD and 0.5 for BC surface concentrations. Compared with aircraft measurements over the Americas at latitudes between 0 and 50N, the average model is a factor of 8 larger than observed, and most models exceed the measured BC standard deviation in the mid to upper troposphere. At higher latitudes the average model to aircraft BC ratio is 0.4 and models underestimate the observed BC loading in the lower and middle troposphere associated with springtime Arctic haze. Low model bias for AAOD but overestimation of surface and upper atmospheric BC concentrations at lower latitudes suggests that most models are underestimating BC absorption and should improve estimates for refractive index, particle size, and optical effects of BC coating. Retrieval uncertainties and/or differences with model diagnostic treatment may also contribute to the model-measurement disparity. Largest AeroCom model diversity occurred in northern Eurasia and the remote Arctic, regions influenced by anthropogenic sources. Changing emissions, aging, removal, or optical properties within a single model generated a smaller change in model predictions than the range represented by the full set of AeroCom models. Upper tropospheric concentrations of BC mass from the aircraft measurements are suggested to provide a unique new benchmark to test scavenging and vertical dispersion of BC in global models.

Culture medium pH influence on Gluconacetobacter physiology: Cellulose production rate and yield enhancement in presence of multiple carbon sources.

PubMed

Yassine, Fatima; Bassil, Nathalie; Flouty, Roula; Chokr, Ali; Samrani, Antoine El; Boiteux, Gisèle; Tahchi, Mario El

2016-08-01

Gluconacetobacter genera are valued for bacterial cellulose (BC) and acetic acid production. BC is produced at optimal yields in classical microbiological media that are expensive for a large scale of production. In addition, BC usage for industrial purposes is limited due to low conversion rate into cellulose and to long incubation duration. In this paper, Gluconacetobacter isolated from apple vinegar was kinetically studied to evaluate cellulose production in presence of different carbon sources. Acetic and citric acid effect on Gluconacetobacter metabolism is clarified. It was shown that Gluconacetobacter uses glucose as a primary carbon source for cells growth and products formation. Acetic acid employment as a co-carbon source in Hestrin Schramm medium showed an increase of 17% in BC yield with a moderate decrease in the crystallite size of the resulting polymer. Copyright © 2016 Elsevier Ltd. All rights reserved.

75 FR 7426 - Periodic Reporting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-19

... change in transportation cost system sampling. The proposal involves distributing rail costs using inter...) sampling, and proposes instead to distribute rail costs using the Inter-BC highway distribution factors. \\1... rail sampling, and to use the TRACS inter-BMC distribtion in place of the Rail distribution key in Cost...

On the spatial distribution and evolution of ultrafine aerosols in urban air

NASA Astrophysics Data System (ADS)

Dall'Osto, M.; Querol, X.; Alastuey, A.; O'Dowd, C.; Harrison, R. M.; Wenger, J.; Gómez-Moreno, F. J.

2012-07-01

Sources and evolution of ultrafine particles (<0.1 μ m diameter) were investigated both horizontally and vertically in the large urban agglomerate of Barcelona, Spain. Within the SAPUSS project (Solving Aerosol Problems by Using Synergistic Strategies), a large number of instruments was deployed simultaneously at different monitoring sites (road, two urban background, regional background, urban tower 150 μa.s.l., urban background tower site 80 m a.s.l.) during a 4 week period in September-October 2010. Particle number concentrations (N>5nm) are highly correlated with black carbon (BC) at all sites only under strong vehicular traffic influences. By contrast, under clean atmospheric conditions (low condensation sinks, CS) such correlation diverges towards much higher N/BC ratios at all sites, indicating additional sources of particles including secondary production of freshly nucleated particles. This is also evident in the urban background annual mean diurnal trend of N/BC, showing a midday peak in all seasons. Size-resolved aerosol distributions (N10-500) as well as particle number concentrations (N>5nm) allow us to identify two types of nucleation and growth events: a regional type event originating in the whole study region and impacting almost simultaneously the urban city of Barcelona and the surrounding background area; and an urban type which originates only within the city centre but whose growth continues while transported away from the city to the regional background. Furthermore, during these clean air days, higher N are found at tower level than at ground level only in the city centre whereas such a difference is not so pronounced at the remote urban background tower. In other words, this study suggests that the column of air above the city ground level possesses the best compromise between low CS and high vapour source, hence enhancing the concentrations of freshly nucleated particles. By contrast, within stagnant polluted atmospheric conditions, higher N and BC concentrations are always measured at ground level relative to tower level at all sites. Our study suggests that the city centre is a source of both non-volatile traffic primary (29-39%) and secondary freshly nucleated particles (up to 61-71%) at all sites. We suggest that organic compounds evaporating from freshly emitted traffic particles are a possible candidate for new particle formation within the city and urban plume.

Factors controlling black carbon distribution in the Arctic

NASA Astrophysics Data System (ADS)

Qi, Ling; Li, Qinbin; Li, Yinrui; He, Cenlin

2017-01-01

We investigate the sensitivity of black carbon (BC) in the Arctic, including BC concentration in snow (BCsnow, ng g-1) and surface air (BCair, ng m-3), as well as emissions, dry deposition, and wet scavenging using the global three-dimensional (3-D) chemical transport model (CTM) GEOS-Chem. We find that the model underestimates BCsnow in the Arctic by 40 % on average (median = 11.8 ng g-1). Natural gas flaring substantially increases total BC emissions in the Arctic (by ˜ 70 %). The flaring emissions lead to up to 49 % increases (0.1-8.5 ng g-1) in Arctic BCsnow, dramatically improving model comparison with observations (50 % reduction in discrepancy) near flaring source regions (the western side of the extreme north of Russia). Ample observations suggest that BC dry deposition velocities over snow and ice in current CTMs (0.03 cm s-1 in the GEOS-Chem) are too small. We apply the resistance-in-series method to compute a dry deposition velocity (vd) that varies with local meteorological and surface conditions. The resulting velocity is significantly larger and varies by a factor of 8 in the Arctic (0.03-0.24 cm s-1), which increases the fraction of dry to total BC deposition (16 to 25 %) yet leaves the total BC deposition and BCsnow in the Arctic unchanged. This is largely explained by the offsetting higher dry and lower wet deposition fluxes. Additionally, we account for the effect of the Wegener-Bergeron-Findeisen (WBF) process in mixed-phase clouds, which releases BC particles from condensed phases (water drops and ice crystals) back to the interstitial air and thereby substantially reduces the scavenging efficiency of clouds for BC (by 43-76 % in the Arctic). The resulting BCsnow is up to 80 % higher, BC loading is considerably larger (from 0.25 to 0.43 mg m-2), and BC lifetime is markedly prolonged (from 9 to 16 days) in the Arctic. Overall, flaring emissions increase BCair in the Arctic (by ˜ 20 ng m-3), the updated vd more than halves BCair (by ˜ 20 ng m-3), and the WBF effect increases BCair by 25-70 % during winter and early spring. The resulting model simulation of BCsnow is substantially improved (within 10 % of the observations) and the discrepancies of BCair are much smaller during the snow season at Barrow, Alert, and Summit (from -67-47 % to -46-3 %). Our results point toward an urgent need for better characterization of flaring emissions of BC (e.g., the emission factors, temporal, and spatial distribution), extensive measurements of both the dry deposition of BC over snow and ice, and the scavenging efficiency of BC in mixed-phase clouds. In addition, we find that the poorly constrained precipitation in the Arctic may introduce large uncertainties in estimating BCsnow. Doubling precipitation introduces a positive bias approximately as large as the overall effects of flaring emissions and the WBF effect; halving precipitation produces a similarly large negative bias.

Neolithic mitochondrial haplogroup H genomes and the genetic origins of Europeans

PubMed Central

Templeton, Jennifer; Brandt, Guido; Soubrier, Julien; Jane Adler, Christina; Richards, Stephen M.; Der Sarkissian, Clio; Ganslmeier, Robert; Friederich, Susanne; Dresely, Veit; van Oven, Mannis; Kenyon, Rosalie; Van der Hoek, Mark B.; Korlach, Jonas; Luong, Khai; Ho, Simon Y. W.; Quintana-Murci, Lluis; Behar, Doron M.; Meller, Harald; Alt, Kurt W.; Cooper, Alan

2014-01-01

Haplogroup (hg) H dominates present-day Western European mitochondrial (mt) DNA variability (>40%), yet was less common (~19%) amongst Early Neolithic farmers (~5450 BC) and virtually absent in Mesolithic hunter-gatherers. Here we investigate this major component of the maternal population history of modern Europeans and sequence 39 complete hg H mitochondrial genomes from ancient human remains. We then compare this ‘real-time’ genetic data with cultural changes taking place between the Early Neolithic (~5450 BC) and Bronze Age (~2200 BC) in Central Europe. Our results reveal that the current diversity and distribution of hg H were largely established by the Mid-Neolithic (~4000 BC), but with substantial genetic contributions from subsequent pan-European cultures such as the Bell Beakers expanding out of Iberia in the Late Neolithic (~2800 BC). Dated hg H genomes allow us to reconstruct the recent evolutionary history of hg H and reveal a mutation rate 45% higher than current estimates for human mitochondria. PMID:23612305

Cross-polar transport and scavenging of Siberian aerosols containing black carbon during the 2012 ACCESS summer campaign

NASA Astrophysics Data System (ADS)

Raut, Jean-Christophe; Marelle, Louis; Fast, Jerome D.; Thomas, Jennie L.; Weinzierl, Bernadett; Law, Katharine S.; Berg, Larry K.; Roiger, Anke; Easter, Richard C.; Heimerl, Katharina; Onishi, Tatsuo; Delanoë, Julien; Schlager, Hans

2017-09-01

During the ACCESS airborne campaign in July 2012, extensive boreal forest fires resulted in significant aerosol transport to the Arctic. A 10-day episode combining intense biomass burning over Siberia and low-pressure systems over the Arctic Ocean resulted in efficient transport of plumes containing black carbon (BC) towards the Arctic, mostly in the upper troposphere (6-8 km). A combination of in situ observations (DLR Falcon aircraft), satellite analysis and WRF-Chem simulations is used to understand the vertical and horizontal transport mechanisms of BC with a focus on the role of wet removal. Between the northwestern Norwegian coast and the Svalbard archipelago, the Falcon aircraft sampled plumes with enhanced CO concentrations up to 200 ppbv and BC mixing ratios up to 25 ng kg-1. During transport to the Arctic region, a large fraction of BC particles are scavenged by two wet deposition processes, namely wet removal by large-scale precipitation and removal in wet convective updrafts, with both processes contributing almost equally to the total accumulated deposition of BC. Our results underline that applying a finer horizontal resolution (40 instead of 100 km) improves the model performance, as it significantly reduces the overestimation of BC levels observed at a coarser resolution in the mid-troposphere. According to the simulations at 40 km, the transport efficiency of BC (TEBC) in biomass burning plumes was larger (60 %), because it was impacted by small accumulated precipitation along trajectory (1 mm). In contrast TEBC was small (< 30 %) and accumulated precipitation amounts were larger (5-10 mm) in plumes influenced by urban anthropogenic sources and flaring activities in northern Russia, resulting in transport to lower altitudes. TEBC due to large-scale precipitation is responsible for a sharp meridional gradient in the distribution of BC concentrations. Wet removal in cumulus clouds is the cause of modeled vertical gradient of TEBC, especially in the mid-latitudes, reflecting the distribution of convective precipitation, but is dominated in the Arctic region by the large-scale wet removal associated with the formation of stratocumulus clouds in the planetary boundary layer (PBL) that produce frequent drizzle.

Bayesian prediction of lung and breast cancer mortality among women in Spain (2014-2020).

PubMed

Martín-Sánchez, Juan Carlos; Clèries, Ramon; Lidón, Cristina; González-de Paz, Luís; Lunet, Nuno; Martínez-Sánchez, Jose M

2016-08-01

Breast cancer (BC) is the main cause of cancer mortality among women, and mortality from lung cancer (LC) is increasing among women. The purpose of the present study was to project the mortality rates of both cancers and predict when LC mortality will exceed BC mortality. The cancer mortality data and female population distribution were obtained from the Spanish National Statistics Institute. Crude rate (CR), age-standardized rate (ASR), and age-specific rate were calculated for the period 1980-2013 and projected for the period 2014-2020 using a Bayesian log-linear Poisson model. All calculated rates were greater for BC than for LC in 2013 (CR, 27.3 versus 17.3; ASR, 13.5 versus 9.3), and the CR was not projected to change by 2020 (29.2 versus 27.6). The ASR for LC is expected to surpass that of BC in 2019 (12.9 versus 12.7). By 2020 the LC mortality rates may exceed those of BC for ages 55-74 years, possibly because of the prevalence of smoking among women, and the screening for and more effective treatment of BC. BC screening could be a good opportunity to help smokers quit by offering counseling and behavioral intervention. Copyright © 2016 Elsevier Ltd. All rights reserved.

Distribution of black carbon in Ponderosa pine litter and soils following the High Park wildfire

NASA Astrophysics Data System (ADS)

Boot, C. M.; Haddix, M.; Paustian, K.; Cotrufo, M. F.

2014-12-01

Black carbon (BC), the heterogeneous product of burned biomass, is a critical component in the global carbon cycle, yet timescales and mechanisms for incorporation into the soil profile are not well understood. The High Park Fire, which took place in northwestern Colorado in the summer of 2012, provided an opportunity to study the effects of both fire intenstiy and geomorphology on properties of carbon (C), nitrogen (N), and BC in the Cache La Poudre River drainage. We sampled montane Ponderosa pine litter, 0-5 cm soils, and 5-15 cm soils four months post-fire in order to examine the effects of slope and burn intensity on %C, C stocks, %N and black carbon (g kg-1 C, and g m-2). We developed and implemented the benzene polycarboxylic acid (BPCA) method for quantifying BC. With regard to slope, we found that steeper slopes had higher C : N than shallow slopes, but that there was no difference in black carbon content or stocks. BC content was greatest in the litter in burned sites (19 g kg-1 C), while BC stocks were greatest in the 5-15 cm subsurface soils (23 g m-2). At the time of sampling, none of the BC deposited on the land surface post-fire had been incorporated into to either the 0-5 cm or 5-15 cm soil layers. The ratio of B5CA : B6CA (less condensed to more condensed BC) indicated there was significantly more older, more processed BC at depth. Total BC soil stocks were relatively low compared to other fire-prone grassland and boreal forest systems, indicating most of the BC produced in this system is likely transported off the surface through erosion events. Future work examining mechanisms for BC transport will be required for understanding the role BC plays in the global carbon cycle.

A Microphysics-Based Black Carbon Aging Scheme in a Global Chemical Transport Model: Constraints from HIPPO Observations

NASA Astrophysics Data System (ADS)

He, C.; Li, Q.; Liou, K. N.; Qi, L.; Tao, S.; Schwarz, J. P.

2015-12-01

Black carbon (BC) aging significantly affects its distributions and radiative properties, which is an important uncertainty source in estimating BC climatic effects. Global models often use a fixed aging timescale for the hydrophobic-to-hydrophilic BC conversion or a simple parameterization. We have developed and implemented a microphysics-based BC aging scheme that accounts for condensation and coagulation processes into a global 3-D chemical transport model (GEOS-Chem). Model results are systematically evaluated by comparing with the HIPPO observations across the Pacific (67°S-85°N) during 2009-2011. We find that the microphysics-based scheme substantially increases the BC aging rate over source regions as compared with the fixed aging timescale (1.2 days), due to the condensation of sulfate and secondary organic aerosols (SOA) and coagulation with pre-existing hydrophilic aerosols. However, the microphysics-based scheme slows down BC aging over Polar regions where condensation and coagulation are rather weak. We find that BC aging is primarily dominated by condensation process that accounts for ~75% of global BC aging, while the coagulation process is important over source regions where a large amount of pre-existing aerosols are available. Model results show that the fixed aging scheme tends to overestimate BC concentrations over the Pacific throughout the troposphere by a factor of 2-5 at different latitudes, while the microphysics-based scheme reduces the discrepancies by up to a factor of 2, particularly in the middle troposphere. The microphysics-based scheme developed in this work decreases BC column total concentrations at all latitudes and seasons, especially over tropical regions, leading to large improvement in model simulations. We are presently analyzing the impact of this scheme on global BC budget and lifetime, quantifying its uncertainty associated with key parameters, and investigating the effects of heterogeneous chemical oxidation on BC aging.

Does the 1H-NMR plasma metabolome reflect the host-tumor interactions in human breast cancer?

PubMed

Richard, Vincent; Conotte, Raphaël; Mayne, David; Colet, Jean-Marie

2017-07-25

Breast cancer (BC) is the most common diagnosed cancer and the leading cause of cancer death in women worldwide. There is an obvious need for a better understanding of BC biology. Alterations in the serum metabolome of BC patients have been identified but their clinical significance remains elusive. We evaluated by 1H-Nuclear Magnetic Resonance (1H-NMR) spectroscopy, filtered plasma metabolome of 50 early (EBC) and 15 metastatic BC (MBC) patients. Using Principal Component Analysis, Partial Least-Squares Discriminant Analysis and Hierarchical Clustering we show that plasma levels of glucose, lactate, pyruvate, alanine, leucine, isoleucine, glutamate, glutamine, valine, lysine, glycine, threonine, tyrosine, phenylalanine, acetate, acetoacetate, β-hydroxy-butyrate, urea, creatine and creatinine are modulated across patients clusters. In particular lactate levels are inversely correlated with the tumor size in the EBC cohort (Pearson correlation r = -0.309; p = 0.044). We suggest that, in BC patients, tumor cells could induce modulation of the whole patient's metabolism even at early stages. If confirmed in a lager study these observations could be of clinical importance.

Inter-comparison of Speciated Aerosol Loading over India for Global and Regional Emission Inventory using a Chemical Transport Model

NASA Astrophysics Data System (ADS)

Upadhyay, Abhishek; Dey, Sagnik; Goyal, Pramila

2017-04-01

Air quality of a region directly affects health of entire biotic and abiotic components of ecosystem. Exposure to particulate matter smaller than 2.5 µm (PM2.5) in atmosphere has been directly related to mortality and mobility in various studies. India is one of the aerosol hotspots globally with 0.8 million premature death attributed to exposure to ambient PM2.5. Robust long-term in-situ data of speciated PM2.5 is lacking in India. The problem cannot be resolved by utilizing satellite data as inferring composition is difficult. Therefore a modelling approach is required. We examine spatial and temporal distribution of PM2.5 and its constituent species with a regional and global inventory through chemical transport model (WRF-Chem) over India. The simulation is conducted with RADM2 chemistry and GOCART aerosol module for 8 years (2007-2014). Emissions are interpolated for domain from global anthropogenic emission inventory RETRO and EDGAR for species other than BC, OC and Sulfate. Results from GOCART global inventory are compared with results from a regional inventory for species OC, BC and Sulfate. Validation of CTM simulations against observations (ground based monitoring stations and satellite observations) demonstrates the capability of the CTM to represent space-time variation of aerosols in this region. For example, the build-up of aerosols over the eastern part of the Indo-Gangetic Basin (IGB) during winter (as observed by space-borne sensors) due to the meteorological influence is well captured by the CTM. A correlation of 0.51 and 0.52 has been observed between monitored and model simulated PM2.5 at the two big cities of India, New Delhi and Mumbai respectively. Distribution of PM2.5 is high in the Indo-Gangetic Basin (IGB) and distribution of OC and BC is also more in IGB region with both emission inventories. In the IGB region OC and BC contribute 8 - 20 % and 2.5 - 5 % to total PM2.5. Global and regional emission inventories are showing similar distribution pattern for OC, BC and Sulfate. GOCART emission inventory is underestimating BC and OC emission in comparison to IITB inventory by almost 50% over the IGB region. Better spatial resolution in the regional inventory may be the reason. WRF-Chem simulated OC and BC concentration is underestimated by 25% and 50% over the IGB region with GOCART inventory compare to regional inventory. In comparison to IGB region other parts of India has lower concentration and these reasons are showing comparatively less difference in concentration in both emission scenario. Vertical distribution of extinction coefficient showing that aerosol concentration is confined to lower levels in winter but it is geting elevated in summer. Our results provide a comprehensive picture of aerosol speciation over India and can be used for further climate and health impact studies.

New archaeomagnetic data from three roman kilns in northeast Spain: a contribution to the Iberian palaeosecular variation curve

NASA Astrophysics Data System (ADS)

Beamud, E.; Gómez-Paccard, M.; McIntosh, G.; Larrasoaña, J. C.

2012-04-01

New archaeomagnetic results from three kilns recovered from a roman age archaeological site in Badalona (northeast Spain) are reported. Archaeological evidences constrain the abandonment of kilns BC1 and BC2 between 0 and 50 yrs AD, whereas the abandonment of kiln BC3 is established between 50 and 150 yrs AD. In order to perform the archaeomagnetic study 12 to 14 samples per kiln were collected using a portable electrical drill with a water-cooled diamond bit, following standard palaeomagnetic sampling methods. Samples were distributed all around the combustion chambers, being obtained in different orientations from the burnt walls and central pillars. Rock magnetic measurements revealed a dominance of low titanium titanomagnetite or substituted magnetite as the main carrier of the magnetic signal and a minor contribution of maghemite. The presence of single domain material, along with the thermal stability of the samples, means that they are suitable candidates for archaeomagnetic studies, and in particular intensity determinations. Archaeomagnetic experiments were attempted on 32 specimens characterised by NRM intensities between 0.5 and 8.3 A/m. Mean archaeomagnetic directions and archaeointensities have been obtained from the original Thellier method with regular partial thermoremanent magnetisation (pTRM) checks being used to estimate archaeointensities. Mean intensities of 68.3 ± 4.2 µT, 72.4 ± 5.0 µT and 72.9 ± 3.7 µT were obtained for kilns BC1, BC2 and BC3, respectively. A cooling rate correction factor of 5% has been applied to mean intensities and the values obtained have been relocated to Paris and Madrid through the virtual dipole moment VDM. The mean directions of the characteristic magnetization of each kiln and their associated statistical parameters were derived from principal component analysis and Fisher statistics. Very similar directions were obtained for BC1 and BC2 with the circle of confidence (α95) of the BC2 direction falling within that of BC1. This is in agreement with archaeological evidence that proposed the same age interval for the abandonment of kilns BC1 and BC2. On the contrary, there is only a small overlapping between the circles of confidence of BC1-BC2 and the BC3 circle of confidence. Moreover, the inclination obtained for the mean BC3 direction is lower than those obtained for kilns BC1-BC2, suggesting that kiln BC3 was abandoned latter than kilns BC1 and BC2. This is in agreement with archaeological evidence that proposed that kiln BC3 was abandoned about 60 years later than kilns BC1 and BC2. The new data are also consistent with previous archaeomagnetic data for the Iberian Peninsula. They add to and improve the description of palaeosecular variation during Roman times in Iberia.

An investigation of the leaf retention capacity, efficiency and mechanism for atmospheric particulate matter of five greening tree species in Beijing, China.

PubMed

Liu, Jinqiang; Cao, Zhiguo; Zou, Songyan; Liu, Huanhuan; Hai, Xiao; Wang, Shihua; Duan, Jie; Xi, Benye; Yan, Guangxuan; Zhang, Shaowei; Jia, Zhongkui

2018-03-01

Urban trees have the potential to reduce air pollution, but the retention capacity and efficiency of different tree species for atmospheric particulate matter (PM) accumulation and the underlying mechanism hasn't been well understood. To select tree species with high air purification abilities, the supplementing ultrasonic cleaning (UC) procedure was first introduced into the conventional leaf cleaning methods [single water cleaning (WC) or plus brush cleaning (BC)] for eluting the leaf-retained PM. Further updates to the methodology were applied to investigate the retention capacity, efficiency, and mechanism for PM of five typical greening tree species in Beijing, China. Meanwhile, the particle size distribution of PM on the leaves, the PM retention efficiencies of easily removable (ERP), difficult-to-remove (DRP) and totally removable (TRP) particles on the leaf (AE leaf ), and the individual tree scales were estimated. The experimental leaf samples were collected from trees with similar sizes 4 (SDR) and 14days (LDR) after rainfall. When the leaves were cleaned by WC+BC, there was, on average, 29%-46% of the PM remaining on the leaves of different species, which could be removed almost completely if UC was supplemented. From SDR to LDR, the mass of the leaf-retained PM increased greatly, and the particle size distribution changed markedly for all species except for Sophorajaponica. Pinus tabuliformis retains particles with the largest average diameter (34.2μm), followed by Ginkgo biloba (20.5μm), Sabina chinensis (16.4μm), Salix babylonica (16.0μm), and S. japonica (13.1μm). S. japonica and S. chinensis had the highest AE leaf to retain the TRP and ERP of both PM 1 and PM 1-2.5 , respectively. Conversely, S. babylonica and P. tabuliformis could retain both TRP and ERP of PM 2.5-5 and PM 5-10 , and PM >10 and TSP with the highest AE leaf , respectively. In conclusion, our results could be useful in selecting greening tree species with high air purification abilities. Copyright © 2017 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, R.; Barth, M. C.; Nair, V. S.

This study examines differences in the surface black carbon (BC) aerosol loading between the Bay of Bengal (BoB) and the Arabian Sea (AS) and identifies dominant sources of BC in South Asia and surrounding regions during March-May 2006 (Integrated Campaign for Aerosols, Gases and Radiation Budget, ICARB) period. A total of 13 BC tracers are introduced in the Weather Research and Forecasting Model coupled with Chemistry to address these objectives. The model reproduced the temporal and spatial variability of BC distribution observed over the AS and the BoB during the ICARB ship cruise and captured spatial variability at the inlandmore » sites. In general, the model underestimates the observed BC mass concentrations. However, the model-observation discrepancy in this study is smaller compared to previous studies. Model results show that ICARB measurements were fairly well representative of the AS and the BoB during the pre-monsoon season. Elevated BC mass concentrations in the BoB are due to 5 times stronger influence of anthropogenic emissions on the BoB compared to the AS. Biomass burning in Burma also affects the BoB much more strongly than the AS. Results show that anthropogenic and biomass burning emissions, respectively, accounted for 60 and 37% of the average +/- standard deviation (representing spatial and temporal variability) BC mass concentration (1341 +/- 2353 ng m(-3)) in South Asia. BC emissions from residential (61 %) and industrial (23 %) sectors are the major anthropogenic sources, except in the Himalayas where vehicular emissions dominate. We find that regional-scale transport of anthropogenic emissions contributes up to 25% of BC mass concentrations in western and eastern India, suggesting that surface BC mass concentrations cannot be linked directly to the local emissions in different regions of South Asia.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, R.; Barth, M. C.; Nair, V. S.

This study examines differences in the surface black carbon (BC) aerosol loading between the Bay of Bengal (BoB) and the Arabian Sea (AS) and identifies dominant sources of BC in South Asia and surrounding regions during March–May 2006 (Integrated Campaign for Aerosols, Gases and Radiation Budget, ICARB) period. A total of 13 BC tracers are introduced in the Weather Research and Forecasting Model coupled with Chemistry to address these objectives. The model reproduced the temporal and spatial variability of BC distribution observed over the AS and the BoB during the ICARB ship cruise and captured spatial variability at the inlandmore » sites. In general, the model underestimates the observed BC mass concentrations. However, the model–observation discrepancy in this study is smaller compared to previous studies. Model results show that ICARB measurements were fairly well representative of the AS and the BoB during the pre-monsoon season. Elevated BC mass concentrations in the BoB are due to 5 times stronger influence of anthropogenic emissions on the BoB compared to the AS. Biomass burning in Burma also affects the BoB much more strongly than the AS. Results show that anthropogenic and biomass burning emissions, respectively, accounted for 60 and 37% of the average ± standard deviation (representing spatial and temporal variability) BC mass concentration (1341 ± 2353 ng m -3) in South Asia. BC emissions from residential (61%) and industrial (23%) sectors are the major anthropogenic sources, except in the Himalayas where vehicular emissions dominate. We find that regional-scale transport of anthropogenic emissions contributes up to 25% of BC mass concentrations in western and eastern India, suggesting that surface BC mass concentrations cannot be linked directly to the local emissions in different regions of South Asia.« less

Dome effect of black carbon and its key influencing factors: a one-dimensional modelling study

NASA Astrophysics Data System (ADS)

Wang, Zilin; Huang, Xin; Ding, Aijun

2018-02-01

Black carbon (BC) has been identified to play a critical role in aerosol-planetary boundary layer (PBL) interaction and further deterioration of near-surface air pollution in megacities, which has been referred to as the dome effect. However, the impacts of key factors that influence this effect, such as the vertical distribution and aging processes of BC, as well as the underlying land surface, have not been quantitatively explored yet. Here, based on available in situ measurements of meteorology and atmospheric aerosols together with the meteorology-chemistry online coupled model WRF-Chem, we conduct a set of parallel simulations to quantify the roles of these factors in influencing the BC dome effect and surface haze pollution. Furthermore, we discuss the main implications of the results to air pollution mitigation in China. We found that the impact of BC on the PBL is very sensitive to the altitude of aerosol layer. The upper-level BC, especially that near the capping inversion, is more essential in suppressing the PBL height and weakening the turbulent mixing. The dome effect of BC tends to be significantly intensified as BC mixed with scattering aerosols during winter haze events, resulting in a decrease in PBL height by more than 15 %. In addition, the dome effect is more substantial (up to 15 %) in rural areas than that in the urban areas with the same BC loading, indicating an unexpected regional impact of such an effect to air quality in countryside. This study indicates that China's regional air pollution would greatly benefit from BC emission reductions, especially those from elevated sources from chimneys and also domestic combustion in rural areas, through weakening the aerosol-boundary layer interactions that are triggered by BC.

RNA recognition by a human antibody against brain cytoplasmic 200 RNA

PubMed Central

Jung, Euihan; Lee, Jungmin; Hong, Hyo Jeong; Park, Insoo; Lee, Younghoon

2014-01-01

Diverse functional RNAs participate in a wide range of cellular processes. The RNA structure is critical for function, either on its own or as a complex form with proteins and other ligands. Therefore, analysis of the RNA conformation in cells is essential for understanding their functional mechanisms. However, no appropriate methods have been established as yet. Here, we developed an efficient strategy for panning and affinity maturation of anti-RNA human monoclonal antibodies from a naïve antigen binding fragment (Fab) combinatorial phage library. Brain cytoplasmic 200 (BC200) RNA, which is also highly expressed in some tumors, was used as an RNA antigen. We identified MabBC200-A3 as the optimal binding antibody. Mutagenesis and SELEX experiments showed that the antibody recognized a domain of BC200 in a structure- and sequence-dependent manner. Various breast cancer cell lines were further examined for BC200 RNA expression using conventional hybridization and immunoanalysis with MabBC200-A3 to see whether the antibody specifically recognizes BC200 RNA among the total purified RNAs. The amounts of antibody-recognizable BC200 RNA were consistent with hybridization signals among the cell lines. Furthermore, the antibody was able to discriminate BC200 RNA from other RNAs, supporting the utility of this antibody as a specific RNA structure-recognizing probe. Intriguingly, however, when permeabilized cells were subjected to immunoanalysis instead of purified total RNA, the amount of antibody-recognizable RNA was not correlated with the cellular level of BC200 RNA, indicating that BC200 RNA exists as two distinct forms (antibody-recognizable and nonrecognizable) in breast cancer cells and that their distribution depends on the cell type. Our results clearly demonstrate that anti-RNA antibodies provide an effective novel tool for detecting and analyzing RNA conformation. PMID:24759090

Comparative Analysis of Calcium Silicate-based Root Filling Materials Using an Open Apex Model.

PubMed

Tran, Dennis; He, Jianing; Glickman, Gerald N; Woodmansey, Karl F

2016-04-01

Many new calcium silicate-based root filling materials have emerged in the market; however, their performance in the orthograde obturation of an open apex has not been evaluated. The purpose of this study was to compare the marginal adaptation of ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK), NeoMTA Plus (Avalon Biomed Inc, Bradenton, FL), and Endosequence BC RRM-Fast Set Putty (BC RRM-FS; Brasseler USA, Savannah, GA) after orthograde placement in roots with open apices. Palatal roots of maxillary molars were instrumented to create divergent open apices and divided into 4 groups for orthograde obturation: ProRoot MTA, NeoMTA Plus, BC RRM-FS, and BC RRM-FS + BC Sealer. Using a scanning electron microscope, the quality of material adaptation at the anatomic apex was evaluated by 5 blinded examiners; 3 mm of the root end was sectioned, and gap distance was measured at the material-dentin interface. Statistical analyses were performed using the Kruskal-Wallis test. There were no significant differences in marginal adaptation among the 4 groups at the level of the anatomic apex (P = .175). BC RRM-FS + BC Sealer had a significantly smaller gap size after 3-mm root end resection compared with the other 3 groups (P < .01). No differences were observed among the other 3 materials. All materials showed comparable marginal adaptation at the anatomic apex when used for orthograde obturation of open apices. Application of BC Sealer before the delivery of BC RRM-FS Putty enhanced the quality of adaptation coronal to the apex. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Controlled release of β-carotene in β-lactoglobulin-dextran-conjugated nanoparticles' in vitro digestion and transport with Caco-2 monolayers.

PubMed

Yi, Jiang; Lam, Tina I; Yokoyama, Wallace; Cheng, Luisa W; Zhong, Fang

2014-09-03

Undesirable aggregation of nanoparticles stabilized by proteins may occur at the protein's isoelectric point when the particle has zero net charge. Stability against aggregation of nanoparticles may be improved by reacting free amino groups with reducing sugars by the Maillard reaction. β-Lactoglobulin (BLG)-dextran conjugates were characterized by SDS-PAGE and CD. Nanoparticles (60-70 nm diameter) of β-carotene (BC) encapsulated by BLG or BLG-dextran were prepared by the homogenization-evaporation method. Both BLG and BLG-dextran nanoparticles appeared to be spherically shaped and uniformly dispersed by TEM. The stability and release of BC from the nanoparticles under simulated gastrointestinal conditions were evaluated. Dextran conjugation prevented the flocculation or aggregation of BLG-dextran particles at pH ∼4-5 compared to very large sized aggregates of BLG nanoparticles. The released contents of BC from BLG and BLG-dextran nanoparticles under acidic gastric conditions were 6.2 ± 0.9 and 5.4 ± 0.3%, respectively. The release of BC from BLG-dextran nanoparticles by trypsin digestion was 51.8 ± 4.3% of total encapsulated BC, and that from BLG nanoparticles was 60.9 ± 2.9%. Neither BLG-BC nanoparticles nor the Maillard-reacted BLG-dextran conjugates were cytotoxic to Caco-2 cells, even at 10 mg/mL. The apparent permeability coefficient (Papp) of Caco-2 cells to BC was improved by nanoencapsulation, compared to free BC suspension. The results indicate that BC-encapsulated β-lactoglobulin-dextran-conjugated nanoparticles are more stable to aggregation under gastric pH conditions with good release and permeability properties.

Facile synthesis of cobalt ferrite nanotubes using bacterial nanocellulose as template.

PubMed

Menchaca-Nal, S; Londoño-Calderón, C L; Cerrutti, P; Foresti, M L; Pampillo, L; Bilovol, V; Candal, R; Martínez-García, R

2016-02-10

A facile method for the preparation of cobalt ferrite nanotubes by use of bacterial cellulose nanoribbons as a template is described. The proposed method relays on a simple coprecipitation operation, which is a technique extensively used for the synthesis of nanoparticles (either isolated or as aggregates) but not for the synthesis of nanotubes. The precursors employed in the synthesis are chlorides, and the procedure is carried out at low temperature (90 °C). By the method proposed a homogeneous distribution of cobalt ferrite nanotubes with an average diameter of 217 nm in the bacterial nanocellulose (BC) aerogel (3%) was obtained. The obtained nanotubes are formed by 26-102 nm cobalt ferrite clusters of cobalt ferrite nanoparticles with diameters in the 9-13 nm interval. The nanoparticles that form the nanotubes showed to have a certain crystalline disorder, which could be attributed in a greater extent to the small crystallite size, and, in a lesser extent, to microstrains existing in the crystalline lattice. The BC-templated-CoFe2O4 nanotubes exhibited magnetic behavior at room temperature. The magnetic properties showed to be influenced by a fraction of nanoparticles in superparamagnetic state. Copyright © 2015 Elsevier Ltd. All rights reserved.

[C677T-SNP of methylenetetrahydrofolate reductase gene and breast cancer in Mexican women].

PubMed

Calderón-Garcidueñas, Ana Laura; Cerda-Flores, Ricardo Martín; Castruita-Ávila, Ana Lilia; González-Guerrero, Juan Francisco; Barrera-Saldaña, Hugo Alberto

2017-01-01

Low-penetrance susceptibility genes such as 5,10-methylenetetrahydrofolate reductase gene (MTHFR) have been considered in the progression of breast cancer (BC). Cancer is a result of genetic, environmental and epigenetic interactions; therefore, these genes should be studied in environmental context, because the results can vary between populations and even within the same country. The objective was to analyze the allelic and genotypic frequencies of the MTHFR C667T SNP in Mexican Mestizo patients with BC and controls from Northeastern Mexico. 243 patients and 118 healthy women were studied. The analysis of the polymorphism was performed with a DNA microarray. Once the frequency of the polymorphism was obtained, Hardy-Weinberg equilibrium test was carried out for the genotypes. Chi square test was used to compare the distribution of frequencies. The allele frequency in patients was: C = 0.5406; T = 0.4594 and in controls C = 0.5678, T = 0.4322. Genotype in BC patients was: C / C = 29.9%, C / T = 48.3% and T / T = 21.8. The distribution in controls was: C / C = 31.4%, C / T = 50.8%, T / T = 17.8% (chi squared 0.77, p = 0.6801). Northeastern Mexican women in this study showed no association between MTFHR C667T SNP and the risk of BC. It seems that the contribution of this polymorphism to BC in Mexico varies depending on various factors, both genetic and environmental.

A Statistical Investigation of the Sensitivity of Ensemble-Based Kalman Filters to Covariance Filtering

DTIC Science & Technology

2011-09-01

the ensemble perturbations fXb(k): k5 1, . . . , Kg are from the same distribution; thus P̂bc ’ 1 K 2 1 K21 k51 Pbtc ’ Pbtc, and (18) p̂bcu ’ p btc u...19) where p̂bcu and p btc u are the uth column of P̂ bc u and P btc u , respectively. Similar arguments can be made to show that the filtered...estimate should also satisfy ~pbcu ’ p btc u , (20) where ~pbcu is the uth column of ~P bc u . We emphasize that Eqs. (19) and (20) do not provide

Effect of secondary organic aerosol coating thickness on the real-time detection and characterization of biomass-burning soot by two particle mass spectrometers

DOE PAGES

Ahern, Adam T.; Subramanian, Ramachandran; Saliba, Georges; ...

2016-12-22

Biomass burning is a large source of light-absorbing refractory black carbon (rBC) particles with a wide range of morphologies and sizes. The net radiative forcing from these particles is strongly dependent on the amount and composition of non-light-absorbing material internally mixed with the rBC and on the morphology of the mixed particles. Understanding how the mixing state and morphology of biomass-burning aerosol evolves in the atmosphere is critical for constraining the influence of these particles on radiative forcing and climate. We investigated the response of two commercial laser-based particle mass spectrometers, the vacuum ultraviolet (VUV) ablation LAAPTOF and the IRmore » vaporization SP-AMS, to monodisperse biomass-burning particles as we sequentially coated the particles with secondary organic aerosol (SOA) from α-pinene ozonolysis. We studied three mobility-selected soot core sizes, each with a number of successively thicker coatings of SOA applied. Using IR laser vaporization, the SP-AMS had different changes in sensitivity to rBC compared to potassium as a function of applied SOA coatings. We show that this is due to different effective beam widths for the IR laser vaporization region of potassium versus black carbon. The SP-AMS's sensitivity to black carbon (BC) mass was not observed to plateau following successive SOA coatings, despite achieving high OA : BC mass ratios greater than 9. We also measured the ion fragmentation pattern of biomass-burning rBC and found it changed only slightly with increasing SOA mass. The average organic matter ion signal measured by the LAAPTOF demonstrated a positive correlation with the condensed SOA mass on individual particles, despite the inhomogeneity of the particle core compositions. This demonstrates that the LAAPTOF can obtain quantitative mass measurements of aged soot-particle composition from realistic biomass-burning particles with complex morphologies and composition.« less

Effect of secondary organic aerosol coating thickness on the real-time detection and characterization of biomass-burning soot by two particle mass spectrometers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahern, Adam T.; Subramanian, Ramachandran; Saliba, Georges

Biomass burning is a large source of light-absorbing refractory black carbon (rBC) particles with a wide range of morphologies and sizes. The net radiative forcing from these particles is strongly dependent on the amount and composition of non-light-absorbing material internally mixed with the rBC and on the morphology of the mixed particles. Understanding how the mixing state and morphology of biomass-burning aerosol evolves in the atmosphere is critical for constraining the influence of these particles on radiative forcing and climate. We investigated the response of two commercial laser-based particle mass spectrometers, the vacuum ultraviolet (VUV) ablation LAAPTOF and the IRmore » vaporization SP-AMS, to monodisperse biomass-burning particles as we sequentially coated the particles with secondary organic aerosol (SOA) from α-pinene ozonolysis. We studied three mobility-selected soot core sizes, each with a number of successively thicker coatings of SOA applied. Using IR laser vaporization, the SP-AMS had different changes in sensitivity to rBC compared to potassium as a function of applied SOA coatings. We show that this is due to different effective beam widths for the IR laser vaporization region of potassium versus black carbon. The SP-AMS's sensitivity to black carbon (BC) mass was not observed to plateau following successive SOA coatings, despite achieving high OA : BC mass ratios greater than 9. We also measured the ion fragmentation pattern of biomass-burning rBC and found it changed only slightly with increasing SOA mass. The average organic matter ion signal measured by the LAAPTOF demonstrated a positive correlation with the condensed SOA mass on individual particles, despite the inhomogeneity of the particle core compositions. This demonstrates that the LAAPTOF can obtain quantitative mass measurements of aged soot-particle composition from realistic biomass-burning particles with complex morphologies and composition.« less

The ``Micro'' Aethalometer - an enabling technology for new applications in the measurement of Aerosol Black Carbon

NASA Astrophysics Data System (ADS)

Hansen, A. D.; Močnik, G.

2010-12-01

Aerosol Black Carbon (BC) is a tracer for combustion emissions; a primary indicator of adverse health effects; and the second leading contributor to Global Climate Change. The “Micro” Aethalometer is a recently-developed miniature instrument that makes a real-time measurement of BC on a very short timebase in a self-contained, battery-powered package that is lightweight and pocket sized. This technological development critically enables new areas of research: Measurements of the vertical profile of BC, by carrying the sampler aloft on a balloon (tethered or released) or aircraft (piloted or UAV); Estimates of the concentration of BC in the troposphere and lower stratosphere in the 8 - 12 km. altitude range, by measurements in the passenger cabin during commercial air travel; Epidemiological studies of personal exposure to BC, by carrying the sampler on a subject person in health studies; Measurements of the concentration of BC in rural and remote regions, by means of a small, battery-powered instrument that is convenient to deploy; measurements of high concentrations of “smoke” in indoor and outdoor environments in developing countries; Unobtrusive monitoring of BC infiltration into indoor environments, by means of a small, quiet instrument that can be placed in publicly-used spaces, school classrooms, museums, and other potentially-impacted locations; Adaptation of the technology to the direct source measurement of BC concentrations in emissions from diesel exhausts, combustion plumes, and other sources. We will show examples of data from various recent projects to illustrate the capabilities and applications of this new instrument.

Preparation and Characterization of PVA Alkaline Solid Polymer Electrolyte with Addition of Bamboo Charcoal.

PubMed

Fan, Lidan; Wang, Mengyue; Zhang, Zhen; Qin, Gang; Hu, Xiaoyi; Chen, Qiang

2018-04-26

Natural bamboo charcoal (BC) powder has been developed as a novel filler in order to further improve performances of the polyvinyl alcohol (PVA)-based alkaline solid polymer electrolyte (ASPE) by solution casting method. X-ray diffraction patterns of composite polymer electrolyte with BC revealed the decrease in the degree of crystallinity with increasing content of BC. Scanning electron microscopy images showed pores on a micrometer scale (average diameter about 2 μm) distributed inside and on the surface of the membranes, indicating a three-dimension network formed in the polymer framework. The ionic conductivity was measured by the alternating-current (AC) impedance method, and the highest conductivity value of 6.63 × 10 −2 S·cm −1 was obtained with 16 wt % of BC content and m KOH : m PVA = 2:1.5 at 30 °C. The contents of BC and KOH could significantly influence the conductivity. The temperature dependence of the bulk electrical conductivity displayed a combination of Arrhenius nature, and the activation energy for the ion in polymer electrolyte has been calculated. The electrochemical stability window of the electrolyte membrane was over 1.6 V. The thermogravimetric analysis curves showed that the degradation temperatures of PVA-BC-KOH ASPE membranes shifted toward higher with adding BC. A simple nickel-hydrogen battery containing PVA-BC-KOH electrolyte membrane was assembled with a maximum discharge capacity of 193 mAh·g −1 .

Seasonal and Interannual Variations in BC Emissions From Open Biomass Burning in Southern Africa From 1998 to 2005

NASA Astrophysics Data System (ADS)

Ito, A.; Akimoto, H.

2006-12-01

We estimate the emissions of black carbon (BC) from open vegetation fires in southern hemisphere Africa from 1998 to 2005 using satellite information in conjunction with a biogeochemical model. Monthly burned areas at a 0.5-degree resolution are estimated from the Visible and Infrared Scanner (VIRS) fire count product and the Moderate Resolution Imaging Spectroradiometer (MODIS) burned area data set associated with the MODIS tree cover imagery in grasslands and woodlands. The monthly fuel load distribution is derived from a 0.5- degree terrestrial carbon cycle model in conjunction with satellite data. The monthly maps of combustion factor and emission factor are estimated using empirical models that predict the effects of fuel conditions on these factors in grasslands and woodlands. Our annual averaged BC emitted per unit area burned is 0.17 g BC m-2 which is consistent with the product of fuel consumption and emission factor typically measured in southern Africa. The BC emissions from open vegetation burning in southern Africa ranged from 0.26 Tg BC yr-1 for 2002 to 0.42 Tg BC yr-1 for 1998. The peak in BC emissions is identical to that from previous top-down estimate using the Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI) data. The sum of monthly emissions during the burning season in 2000 is in good agreement between our estimate (0.38 Tg) and previous estimate constrained by numerical model and measurements (0.47 Tg).

Knockdown of synaptic scaffolding protein Homer 1b/c attenuates secondary hyperalgesia induced by complete Freund's adjuvant in rats.

PubMed

Yao, Yong-Xing; Jiang, Zhen; Zhao, Zhi-Qi

2011-12-01

Previous studies have demonstrated that Homer 1b/c, a postsynaptic molecular scaffolding protein that binds and clusters metabotropic glutamate receptors at neuronal synapses, has an important role in the metabotropic glutamate receptor signaling process. In the current study, we investigated the possible involvement of Homer 1b/c in secondary hyperalgesia induced by complete Freund's adjuvant (CFA). Chronic inflammation was induced by injecting CFA into the left hind ankle of Wistar rats. Homer 1b/c antisense or missense oligonucleotides were intrathecally administrated (antisense, 10 μg/10 μL, 5 μg/10 μL, or 2.5 μg/10 μL, once a day; missense, 10 μg/10 μL) from 5 to 8 days after the onset of inflammation. The withdrawal threshold and withdrawal latency to mechanical or thermal stimuli were determined before and after the intrathecal administration. The expression and distribution of Homer 1b/c were examined in the spinal cord using immunological techniques. Mechanical allodynia and thermal hyperalgesia were induced within 24 hours and maintained for >2 weeks after the CFA injection. The expression of Homer 1b/c reached the highest level 7 days after inflammation and returned to baseline at day 28. Intrathecal administration of Homer 1b/c antisense oligonucleotides markedly reduced the expression of Homer 1b/c protein in the spinal cord. Additionally, administration of Homer 1b/c antisense oligonucleotides attenuated secondary mechanical hypersensitization on days 2 to 5 and reduced thermal hypersensitization on days 3 to 4. There were no effects of missense oligonucleotides on hypersensitization and the expression of Homer 1b/c. In the naïve rats, Homer 1b/c antisense oligonucleotides did not affect the mechanical and thermal responses or locomotor activity. These novel results demonstrate that Homer 1b/c in the spinal cord contributes to the maintenance of secondary hyperalgesia induced by CFA and suggest that Homer 1b/c may be a novel target for pain therapy.

Size-resolved measurements of mixing state and cloud-nucleating ability of aerosols in Nanjing, China

NASA Astrophysics Data System (ADS)

Ma, Yan; Li, Shizheng; Zheng, Jun; Khalizov, Alexei; Wang, Xing; Wang, Zhen; Zhou, Yaoyao

2017-09-01

An integrated aerosol analytical system was deployed in Nanjing, a megacity in the Yangtze River Delta, to measure size-resolved aerosol mixing states, effective densities, cloud condensation nucleus (CCN) activities, and chemical composition in August 2013. It was found that aerosols were predominantly internally mixed. The average effective densities were 1.38 ± 0.09, 1.48 ± 0.08, and 1.53 ± 0.07 g cm-3 for 50, 80, and 120 nm particles, respectively. Although black carbon (BC) represented only 0.3%, 1.6%, and 3.3% of the particle mass, on average, it was present in 7%, 38%, and 47% of the total particle number concentration at 50, 80, and 120 nm, respectively, indicating that BC particles may contribute significantly to the total atmospheric aerosol population. Externally mixed BC was only occasionally observed with an effective density of 0.67-0.97 g cm-3. Aerosols sampled generally exhibited a relatively high CCN activity and hygroscopicity (κ = 0.35 ± 0.13). Both newly formed particles and freshly emitted BC particles were observed to age rapidly from photochemical processes, with a significant enhancement in the particle CCN activity and an increase in the effective density. Aerosols influenced by four different air masses presented similar CCN activation, indicating that CCN activation would be primarily dependent on the particle size rather than the particle origin (and hence original composition). Our results suggest that under highly active photochemical conditions as encountered in this study, particles from both local sources and regional transport can be rapidly converted into efficient CCN by photochemical aging, thereby making important contributions to the atmospheric CCN budget and exerting profound implications on aerosol indirect climate forcing.

Clinical and histopathological factors associated with Ki-67 expression in breast cancer patients

PubMed Central

ALCO, GUL; BOZDOGAN, ATILLA; SELAMOGLU, DERYA; PILANCI, KEZBAN NUR; TUZLALI, SITKI; ORDU, CETIN; IGDEM, SEFIK; OKKAN, SAIT; DINCER, MAKTAV; DEMIR, GOKHAN; OZMEN, VAHIT

2015-01-01

The aim of the present study was to identify the optimal Ki-67 cut-off value in breast cancer (BC) patients, and investigate the association of Ki-67 expression levels with other prognostic factors. Firstly, a retrospective search was performed to identify patients with stage I–III BC (n=462). A range of Ki-67 index values were then assigned to five groups (<10, 10–14, 15–19, 20–24 and ≥25%). The correlation between the Ki-67 index and other prognostic factors [age, tumor type, histological and nuclear grade, tumor size, multifocality, an in situ component, lymphovascular invasion (LVI), estrogen and progesterone receptor (ER/PR) expression, human epidermal growth factor receptor (HER-2) status, axillary involvement and tumor stage] were investigated in each group. The median Ki-67 value was revealed to be 20% (range, 1–95%). A young age (≤40 years old), tumor type, size and grade, LVI, ER/PR negativity and HER-2 positivity were revealed to be associated with the Ki-67 level. Furthermore, Ki-67 was demonstrated to be negatively correlated with ER/PR expression (P<0.001), but positively correlated with tumor size (P<0.001). The multivariate analysis revealed that a Ki-67 value of ≥15% was associated with the largest number of poor prognostic factors (P=0.036). In addition, a Ki-67 value of ≥15% was identified to be statistically significant in association with certain luminal subtypes. The rate of disease-free survival was higher in patients with luminal A subtype BC (P=0.036). Following the correlation analysis for the Ki-67 index and the other prognostic factors, a Ki-67 value of ≥15% was revealed to be the optimal cut-off level for BC patients. PMID:25663855

Prognostic Effects of Adjuvant Chemotherapy-Induced Amenorrhea and Subsequent Resumption of Menstruation for Premenopausal Breast Cancer Patients.

PubMed

Jeon, Se Jeong; Lee, Jae Il; Jeon, Myung Jae; Lee, Maria

2016-04-01

Chemotherapy-induced amenorrhea (CIA) is a side effect that occurs in patients with breast cancer (BC) as a result of chemotherapy. These patients require special treatments to avoid infertility and menopause. However, the factors controlling CIA, resumption of menstruation (RM), and persistence of menstruation after chemotherapy are unknown. The long-term prognosis for premenopausal patients with BC and the prognostic factors associated with CIA and RM are subject to debate. We performed a retrospective study by reviewing the medical records of 249 patients with BC (stage I to stage III) who were treated with cytotoxic chemotherapy. The median patient age was 43 (range, 26-55 years) and the median duration of follow-up was 64 months (range, 28-100 months). The medical records indicated that 219 patients (88.0%) scored as positive for the hormone receptor (HR); the majority of these patients completed chemotherapy and then received additional therapy of tamoxifen. Our analyses revealed that 88.0% (n = 219) of patients experienced CIA, and the percentage of RM during follow-up was 48.6% (n = 121). A total of 30 patients (12.0%) did not experience CIA. Disease-free survival (DFS) was affected by several factors, including tumour size ≥2 cm, node positivity, HR negative status, and body mass index ≥23 kg/m. Multivariate analysis indicated that tumour size ≥2 cm remained as a significant factor for DFS (hazard ratio = 3.3, P = 0.034). In summary, this study finds that the majority of premenopausal patients with BC (stage I to stage III) who receive chemotherapy experience CIA and subsequent RM. Although tumour size ≥2 cm is negatively associated with DFS, RM after CIA is not associated with poor prognosis.

Distribution and sources of dissolved black carbon in surface waters of the Chukchi Sea, Bering Sea, and the North Pacific Ocean

NASA Astrophysics Data System (ADS)

Nakane, Motohiro; Ajioka, Taku; Yamashita, Youhei

2017-05-01

Pyrogenic carbon, also called black carbon (BC), is an important component in the global carbon cycle. BC produced by biomass burning or fossil fuel combustion is transported to oceans by the atmosphere or rivers. However, environmental dynamics (i.e., major sources and sinks) of BC in marine environments have not been well documented. In this study, dissolved BC (DBC) collected from surface waters of the Chukchi Sea, the Bering Sea, and the subarctic and subtropical North Pacific were analyzed using the benzene polycarboxylic acid (BPCA) method. The DBC concentration and the ratio of B5CA and B6CA to all BPCAs (an index of the DBC condensation degree) ranged from 4.8 to 15.5 µg-C L-1 and from 0.20 to 0.43, respectively, in surface waters of the Chukchi/Bering Seas and the North Pacific Ocean. The concentration and condensation degree of DBC in the Chukchi/Bering Seas were higher and more variable than those in the subarctic and subtropical North Pacific, which implies that the major factors controlling DBC distribution were different in these marine provinces. In the Chukchi/Bering Seas, the DBC concentration was negatively correlated to salinity but positively correlated to chromophoric dissolved organic matter (CDOM) quantity and total dissolved lignin phenol concentration estimated by CDOM parameters. These correlations indicated that the possible major source of DBC in the Chukchi/Bering Seas was Arctic rivers. However, in the North Pacific, where riverine inputs are negligible for most sampling sites, DBC was possibly derived from the atmosphere. Although spectral slopes of CDOM at 275-295 nm (an index of the photodegradation degree of CDOM) differed widely between the subarctic and subtropical North Pacific, the concentration and condensation degrees of DBC were similar between the subarctic and subtropical North Pacific, which suggests that photodegradation was not the only major factor controlling DBC distribution. Therefore, DBC distributions of the North Pacific Ocean were considered to be mainly controlled by atmospheric deposition of BC and subsequent losses by photodegradation and adsorption onto sinking particles. This study implies that the main influence on DBC distribution in the open ocean and the coastal ocean are atmospheric deposition and fluvial inputs, respectively.

Acute Respiratory Inflammation in Children and Black Carbon in Ambient Air before and during the 2008 Beijing Olympics

PubMed Central

Lin, Weiwei; Huang, Wei; Hu, Min; Brunekreef, Bert; Zhang, Yuanhang; Liu, Xingang; Cheng, Hong; Gehring, Ulrike; Li, Chengcai; Tang, Xiaoyan

2011-01-01

Background: Epidemiologic evidence for a causative association between black carbon (BC) and health outcomes is limited. Objectives: We estimated associations and exposure–response relationships between acute respiratory inflammation in schoolchildren and concentrations of BC and particulate matter with an aerodynamic diameter of ≤ 2.5 μm (PM2.5) in ambient air before and during the air pollution intervention for the 2008 Beijing Olympics. Methods: We measured exhaled nitric oxide (eNO) as an acute respiratory inflammation biomarker and hourly mean air pollutant concentrations to estimate BC and PM2.5 exposure. We used 1,581 valid observations of 36 subjects over five visits in 2 years to estimate associations of eNO with BC and PM2.5 according to generalized estimating equations with polynomial distributed-lag models, controlling for body mass index, asthma, temperature, and relative humidity. We also assessed the relative importance of BC and PM2.5 with two-pollutant models. Results: Air pollution concentrations and eNO were clearly lower during the 2008 Olympics. BC and PM2.5 concentrations averaged over 0–24 hr were strongly associated with eNO, which increased by 16.6% [95% confidence interval (CI), 14.1–19.2%] and 18.7% (95% CI, 15.0–22.5%) per interquartile range (IQR) increase in BC (4.0 μg/m3) and PM2.5 (149 μg/m3), respectively. In the two-pollutant model, estimated effects of BC were robust, but associations between PM2.5 and eNO decreased with adjustment for BC. We found that eNO was associated with IQR increases in hourly BC concentrations up to 10 hr after exposure, consistent with effects primarily in the first hours after exposure. Conclusions: Recent exposure to BC was associated with acute respiratory inflammation in schoolchildren in Beijing. Lower air pollution levels during the 2008 Olympics also were associated with reduced eNO. PMID:21642045

Evaluation of preindustrial to present-day black carbon and its albedo forcing from Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

NASA Technical Reports Server (NTRS)

Lee, Y. H.; Lamarque, J.-F.; Flanner, M. G.; Jiao, C.; Shindell, D. T.; Bernsten, T.; Bisiaux, M. M.; Cao, J.; Collins, W. J.; Curran, M.;

Impulse noise: can hitting a softball harm your hearing?

PubMed

Cook, Korrine; Atcherson, Samuel R

2014-01-01

The purpose of this study is to identify whether or not different materials of softball bats (wooden, aluminum, and composite) are a potential risk harm to hearing when batting players strike a 12'' core .40 softball during slow, underhand pitch typical of recreational games. Peak sound pressure level measurements and spectral analyses were conducted for three controlled softball pitches to a batting participant using each of the different bat materials in an unused outdoor playing field with regulation distances between the pitcher's mound and batter's box. The results revealed that highest recorded peak sound pressure level was recorded from the aluminum (124.6 dBC) bat followed by the composite (121.2 dBC) and wooden (120.0 dBC) bats. Spectral analysis revealed composite and wooden bats with similar broadly distributed amplitude-frequency response. The aluminum bat also produced a broadly distributed amplitude-frequency response, but there were also two very distinct peaks at around 1700 Hz and 2260 Hz above the noise floor that produced its ringing (or ping) sound after being struck. Impulse (transient) sounds less than 140 dBC may permit multiple exposures, and softball bats used in a recreational slow pitch may pose little to no risk to hearing.

Impulse Noise: Can Hitting a Softball Harm Your Hearing?

PubMed Central

Atcherson, Samuel R.

2014-01-01

The purpose of this study is to identify whether or not different materials of softball bats (wooden, aluminum, and composite) are a potential risk harm to hearing when batting players strike a 12′′ core .40 softball during slow, underhand pitch typical of recreational games. Peak sound pressure level measurements and spectral analyses were conducted for three controlled softball pitches to a batting participant using each of the different bat materials in an unused outdoor playing field with regulation distances between the pitcher's mound and batter's box. The results revealed that highest recorded peak sound pressure level was recorded from the aluminum (124.6 dBC) bat followed by the composite (121.2 dBC) and wooden (120.0 dBC) bats. Spectral analysis revealed composite and wooden bats with similar broadly distributed amplitude-frequency response. The aluminum bat also produced a broadly distributed amplitude-frequency response, but there were also two very distinct peaks at around 1700 Hz and 2260 Hz above the noise floor that produced its ringing (or ping) sound after being struck. Impulse (transient) sounds less than 140 dBC may permit multiple exposures, and softball bats used in a recreational slow pitch may pose little to no risk to hearing. PMID:24778596

Re-evaluating black carbon in the Himalayas and the Tibetan Plateau: concentrations and deposition

NASA Astrophysics Data System (ADS)

Li, Chaoliu; Yan, Fangping; Kang, Shichang; Chen, Pengfei; Han, Xiaowen; Hu, Zhaofu; Zhang, Guoshuai; Hong, Ye; Gao, Shaopeng; Qu, Bin; Zhu, Zhejing; Li, Jiwei; Chen, Bing; Sillanpää, Mika

2017-10-01

Black carbon (BC) is the second most important warming component in the atmosphere after CO2. The BC in the Himalayas and the Tibetan Plateau (HTP) has influenced the Indian monsoon and accelerated the retreat of glaciers, resulting in serious consequences for billions of Asian residents. Although a number of related studies have been conducted in this region, the BC concentrations and deposition rates remain poorly constrained. Because of the presence of arid environments and the potential influence of carbonates in mineral dust (MD), the reported BC concentrations in the HTP are overestimated. In addition, large discrepancies have been reported among the BC deposition derived from lake cores, ice cores, snow pits and models. Therefore, the actual BC concentration and deposition values in this sensitive region must be determined. A comparison between the BC concentrations in acid (HCl)-treated and untreated total suspected particle samples from the HTP showed that the BC concentrations previously reported for the Nam Co station (central part of the HTP) and the Everest station (northern slope of the central Himalayas) were overestimated by approximately 52 ± 35 and 39 ± 24 %, respectively, because of the influence of carbonates in MD. Additionally, the organic carbon (OC) levels were overestimated by approximately 22 ± 10 and 22 ± 12 % for the same reason. Based on previously reported values from the study region, we propose that the actual BC concentrations at the Nam Co and Everest stations are 61 and 154 ng m-3, respectively. Furthermore, a comprehensive comparison of the BC deposition rates obtained via different methods indicated that the deposition of BC in HTP lake cores was mainly related to river sediment transport from the lake basin as a result of climate change (e.g., increases in temperature and precipitation) and that relatively little BC deposition occurred via atmospheric deposition. Therefore, previously reported BC deposition rates from lake cores overestimated the atmospheric deposition of BC in the HTP. Correspondingly, BC deposition derived from snow pits and ice cores agreed well with that derived from models, implying that the BC depositions of these two methods reflect the actual values in the HTP. Therefore, based on reported values from snow pits and ice cores, we propose that the BC deposition in the HTP is 17. 9 ± 5. 3 mg m-2 a-1, with higher and lower values appearing along the fringes and central areas of the HTP, respectively. These adjusted BC concentrations and deposition values in the HTP are critical for performing accurate evaluations of other BC factors, such as atmospheric distribution, radiative forcing and chemical transport in the HTP.

Multi-Wavelength Measurement of Soot Optical Properties: Influence of Non-Absorbing Coatings

NASA Astrophysics Data System (ADS)

Freedman, Andrew; Renbaum-Wollf, Lindsay; Forestieri, Sara; Lambe, Andrew; Cappa, Christopher; Davidovits, Paul; Onasch, Timothy

2015-04-01

Soot, a product of incomplete combustion, plays an important role in the earth's climate system through the absorption and scattering of solar radiation. Important in quantifying the direct radiative impacts of soot in climate models, and specifically of black carbon (BC), is the assumed BC refractive index and shape-dependent interaction of light with BC particles. The latter assumption carries significant uncertainty because BC particles are fractal-like, being agglomerates of smaller (20-40 nm) spherules, yet many optical models such as Mie theory in particular, typically assume a spherical particle morphology. It remains unclear under what conditions this is an acceptable assumption. To investigate the ability of various optical models to reproduce observed BC optical properties, we obtained measurements of light absorption, scattering and extinction coefficients and thus single scattering albedo (SSA) of size-resolved soot particles. Measurements were made on denuded soot particles produced using both methane and ethylene as fuels. In addition, these soot particles were coated with dioctyl sebacate or sulfuric acid and the enhancement in the apparent mass absorption coefficient determined. Extinction and absorption were measured using a dual cavity ringdown photoacoustic spectrometer (CRD-PAS) at 405 nm and 532 nm. Scattering and extinction were measured using a CAPS PMssa single scattering albedo monitor (Aerodyne) at 630 nm. Soot particle mass was quantified using a centrifugal particle mass analyzer (CPMA, Cambustion), mobility size with a scanning mobility particle sizer (SMPS, TSI) and soot concentration with a CPC (Brechtel). The results will be interpreted in light of both Mie theory which assumes spherical and uniform particles and Rayleigh-Debye-Gans (RDG) theory, which assumes that the absorption properties of soot are dictated by the individual spherules. For denuded soot, effective refractive indices will be determined.

Quantification of online removal of refractory black carbon using laser-induced incandescence in the single particle soot photometer

DOE PAGES

Aiken, Allison C.; McMeeking, Gavin R.; Levin, Ezra J. T.; ...

2016-04-05

Refractory black carbon (rBC) is an aerosol that has important impacts on climate and human health. rBC is often mixed with other species, making it difficult to isolate and quantify its important effects on physical and optical properties of ambient aerosol. To solve this measurement challenge, a new method to remove rBC was developed using laser-induced incandescence (LII) by Levin et al. in 2014. Application of the method with the Single Particle Soot Photometer (SP2) is used to determine the effects of rBC on ice nucleating particles (INP). Here, we quantify the efficacy of the method in the laboratory usingmore » the rBC surrogate Aquadag. Polydisperse and mobility-selected samples (100–500 nm diameter, 0.44–36.05 fg), are quantified by a second SP2. Removal rates are reported by mass and number. For the mobility-selected samples, the average percentages removed by mass and number of the original size are 88.9 ± 18.6% and 87.3 ± 21.9%, respectively. Removal of Aquadag is efficient for particles >100 nm mass-equivalent diameter (d me), enabling application for microphysical studies. However, the removal of particles ≤100 nm d me is less efficient. Absorption and scattering measurements are reported to assess its use to isolate brown carbon (BrC) absorption. Scattering removal rates for the mobility-selected samples are >90% on average, yet absorption rates are 53% on average across all wavelengths. Therefore, application to isolate effects of microphysical properties determined by larger sizes is promising, but will be challenging for optical properties. Lastly, the results reported also have implications for other instruments employing internal LII, e.g., the Soot Particle Aerosol Mass Spectrometer (SP-AMS).« less

Siberian Arctic black carbon sources constrained by model and observation

PubMed Central

Andersson, August; Eckhardt, Sabine; Stohl, Andreas; Semiletov, Igor P.; Dudarev, Oleg V.; Charkin, Alexander; Shakhova, Natalia; Klimont, Zbigniew; Heyes, Chris; Gustafsson, Örjan

2017-01-01

Black carbon (BC) in haze and deposited on snow and ice can have strong effects on the radiative balance of the Arctic. There is a geographic bias in Arctic BC studies toward the Atlantic sector, with lack of observational constraints for the extensive Russian Siberian Arctic, spanning nearly half of the circum-Arctic. Here, 2 y of observations at Tiksi (East Siberian Arctic) establish a strong seasonality in both BC concentrations (8 ng⋅m−3 to 302 ng⋅m−3) and dual-isotope–constrained sources (19 to 73% contribution from biomass burning). Comparisons between observations and a dispersion model, coupled to an anthropogenic emissions inventory and a fire emissions inventory, give mixed results. In the European Arctic, this model has proven to simulate BC concentrations and source contributions well. However, the model is less successful in reproducing BC concentrations and sources for the Russian Arctic. Using a Bayesian approach, we show that, in contrast to earlier studies, contributions from gas flaring (6%), power plants (9%), and open fires (12%) are relatively small, with the major sources instead being domestic (35%) and transport (38%). The observation-based evaluation of reported emissions identifies errors in spatial allocation of BC sources in the inventory and highlights the importance of improving emission distribution and source attribution, to develop reliable mitigation strategies for efficient reduction of BC impact on the Russian Arctic, one of the fastest-warming regions on Earth. PMID:28137854

Women's Benefits and Harms Trade-Offs in Breast Cancer Screening: Results from a Discrete-Choice Experiment.

PubMed

Sicsic, Jonathan; Pelletier-Fleury, Nathalie; Moumjid, Nora

2018-01-01

Over the past decade, the benefits and harms balance of breast cancer (BC) screening has been widely debated. To elicit women's trade-offs between the benefits and harms of BC screening and to analyze the main determinants of these trade-offs. A discrete-choice experiment with seven attributes depicting BC screening programs including varying levels of BC mortality, overdiagnosis, and false-positive result was used. Eight hundred twelve women aged 40 to 74 years with no personal history of BC recruited by a survey institute and representative of the French general population (age, socioeconomic level, and geographical location) completed the discrete-choice experiment. Preference heterogeneity was investigated using generalized multinomial logit models from which individual trade-offs were derived, and their main determinants were assessed using generalized linear models. Screening acceptance rates under various benefits and harms ratios were simulated on the basis of the distribution of individual preferences. The women would be willing to accept on average 14.1 overdiagnosis cases (median = 9.6) and 47.8 false-positive results (median = 27.2) to avoid one BC-related death. After accounting for preference heterogeneity, less than 50% of women would be willing to accept 10 overdiagnosis cases for one BC-related death avoided. Screening acceptance rates were higher among women with higher socioeconomic level and lower among women with poor health. Women are sensitive to both the benefits and the harms of BC screening and their preferences are highly heterogeneous. Our study provides useful results for public health authorities and clinicians willing to improve their recommendations of BC screening on the basis of women's preferences. Copyright © 2018 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Body composition for health and performance: a survey of body composition assessment practice carried out by the Ad Hoc Research Working Group on Body Composition, Health and Performance under the auspices of the IOC Medical Commission.

PubMed

Meyer, Nanna L; Sundgot-Borgen, Jorunn; Lohman, Timothy G; Ackland, Timothy R; Stewart, Arthur D; Maughan, Ronald J; Smith, Suzanne; Müller, Wolfram

2013-11-01

Successful performers in weight-sensitive sports are characterised by low body mass (BM) and fat content. This often requires chronic energy restriction and acute weight loss practices. To evaluate current use of body composition (BC) assessment methods and identify problems and solutions with current BC approaches. A 40-item survey was developed, including demographic and content questions related to BC assessment. The survey was electronically distributed among international sporting organisations. Frequencies and χ(2) analyses were computed. 216 responses were received, from 33 countries, representing various institutions, sports and competitive levels. Of the sample, 86% of respondents currently assess BC, most frequently using skinfolds (International Society for the Advancement of Kinanthropometry (ISAK): 50%; non-ISAK, conventional: 40%; both: 28%), dual energy X-ray absorptiometry (38%), bioelectrical impedance (29%), air displacement plethysmography (17%) and hydrostatic weighing (10%). Of those using skinfolds, more at the international level used ISAK, whereas conventional approaches were more reported at regional/national level (p=0.006). The sport dietitian/nutritionist (57%) and physiologist/sports scientist (54%) were most frequently the professionals assessing BC, followed by MDs and athletic trainers, with some reporting coaches (5%). 36% of 116 respondents assessed hydration status and more (64%) did so at international than regional/national level (36%, p=0.028). Of 125 participants answering the question of whether they thought that BC assessment raised problems, 69% said 'yes', with most providing ideas for solutions. Results show high use of BC assessment but also a lack of standardisation and widespread perception of problems related to BM and BC in sport. Future work should emphasise standardisation with appropriate training opportunities and more research on BC and performance.

Distribution of black carbon in ponderosa pine forest floor and soils following the High Park wildfire

NASA Astrophysics Data System (ADS)

Boot, C. M.; Haddix, M.; Paustian, K.; Cotrufo, M. F.

2015-05-01

Biomass burning produces black carbon (BC), effectively transferring a fraction of the biomass C from an actively cycling pool to a passive C pool, which may be stored in the soil. Yet the timescales and mechanisms for incorporation of BC into the soil profile are not well understood. The High Park fire (HPF), which occurred in northwestern Colorado in the summer of 2012, provided an opportunity to study the effects of both fire severity and geomorphology on properties of carbon (C), nitrogen (N) and BC in the Cache La Poudre River drainage. We sampled montane ponderosa pine forest floor (litter plus O-horizon) and soils at 0-5 and 5-15 cm depth 4 months post-fire in order to examine the effects of slope and burn severity on %C, C stocks, %N and BC. We used the benzene polycarboxylic acid (BPCA) method for quantifying BC. With regard to slope, we found that steeper slopes had higher C : N than shallow slopes but that there was no difference in BPCA-C content or stocks. BC content was greatest in the forest floor at burned sites (19 g BPCA-C kg-1 C), while BC stocks were greatest in the 5-15 cm subsurface soils (23 g BPCA-C m-2). At the time of sampling, unburned and burned soils had equivalent BC content, indicating none of the BC deposited on the land surface post-fire had been incorporated into either the 0-5 or 5-15 cm soil layers. The ratio of B6CA : total BPCAs, an index of the degree of aromatic C condensation, suggested that BC in the 5-15 cm soil layer may have been formed at higher temperatures or experienced selective degradation relative to the forest floor and 0-5 cm soils. Total BC soil stocks were relatively low compared to other fire-prone grassland and boreal forest systems, indicating most of the BC produced in this system is likely lost, either through erosion events, degradation or translocation to deeper soils. Future work examining mechanisms for BC losses from forest soils will be required for understanding the role BC plays in the global carbon cycle.

Impacts of global, regional, and sectoral black carbon emission reductions on surface air quality and human mortality

NASA Astrophysics Data System (ADS)

Anenberg, S. C.; Talgo, K.; Arunachalam, S.; Dolwick, P.; Jang, C.; West, J. J.

2011-07-01

As a component of fine particulate matter (PM2.5), black carbon (BC) is associated with premature human mortality. BC also affects climate by absorbing solar radiation and reducing planetary albedo. Several studies have examined the climate impacts of BC emissions, but the associated health impacts have been studied less extensively. Here, we examine the surface PM2.5 and premature mortality impacts of halving anthropogenic BC emissions globally and individually from eight world regions and three major economic sectors. We use a global chemical transport model, MOZART-4, to simulate PM2.5 concentrations and a health impact function to calculate premature cardiopulmonary and lung cancer deaths. We estimate that halving global anthropogenic BC emissions reduces outdoor population-weighted average PM2.5 by 542 ng m-3 (1.8 %) and avoids 157 000 (95 % confidence interval, 120 000-194 000) annual premature deaths globally, with the vast majority occurring within the source region. Most of these avoided deaths can be achieved by halving emissions in East Asia (China; 54 %), followed by South Asia (India; 31 %), however South Asian emissions have 50 % greater mortality impacts per unit BC emitted than East Asian emissions. Globally, halving residential, industrial, and transportation emissions contributes 47 %, 35 %, and 15 % to the avoided deaths from halving all anthropogenic BC emissions. These contributions are 1.2, 1.2, and 0.6 times each sector's portion of global BC emissions, owing to the degree of co-location with population globally. We find that reducing BC emissions increases regional SO4 concentrations by up to 28 % of the magnitude of the regional BC concentration reductions, due to reduced absorption of radiation that drives photochemistry. Impacts of residential BC emissions are likely underestimated since indoor PM2.5 exposure is excluded. We estimate ∼8 times more avoided deaths when BC and organic carbon (OC) emissions are halved together, suggesting that these results greatly underestimate the full air pollution-related mortality benefits of BC mitigation strategies which generally decrease both BC and OC. The choice of concentration-response factor and health effect thresholds affects estimated global avoided deaths by as much as 56 % but does not strongly affect the regional distribution. Confidence in our results would be strengthened by reducing uncertainties in emissions, model parameterization of aerosol processes, grid resolution, and PM2.5 concentration-mortality relationships globally.

Estimation of the cure rate in Iranian breast cancer patients.

PubMed

Rahimzadeh, Mitra; Baghestani, Ahmad Reza; Gohari, Mahmood Reza; Pourhoseingholi, Mohamad Amin

2014-01-01

Although the Cox's proportional hazard model is the popular approach for survival analysis to investigate significant risk factors of cancer patient survival, it is not appropriate in the case of log-term disease free survival. Recently, cure rate models have been introduced to distinguish between clinical determinants of cure and variables associated with the time to event of interest. The aim of this study was to use a cure rate model to determine the clinical associated factors for cure rates of patients with breast cancer (BC). This prospective cohort study covered 305 patients with BC, admitted at Shahid Faiazbakhsh Hospital, Tehran, during 2006 to 2008 and followed until April 2012. Cases of patient death were confirmed by telephone contact. For data analysis, a non-mixed cure rate model with Poisson distribution and negative binomial distribution were employed. All analyses were carried out using a developed Macro in WinBugs. Deviance information criteria (DIC) were employed to find the best model. The overall 1-year, 3-year and 5-year relative survival rates were 97%, 89% and 74%. Metastasis and stage of BC were the significant factors, but age was significant only in negative binomial model. The DIC also showed that the negative binomial model had a better fit. This study indicated that, metastasis and stage of BC were identified as the clinical criteria for cure rates. There are limited studies on BC survival which employed these cure rate models to identify the clinical factors associated with cure. These models are better than Cox, in the case of long-term survival.

Characterization of LiBC by phase-contrast scanning transmission electron microscopy.

PubMed

Krumeich, Frank; Wörle, Michael; Reibisch, Philipp; Nesper, Reinhard

2014-08-01

LiBC was used as a model compound for probing the applicability of phase-contrast (PC) imaging in an aberration-corrected scanning transmission electron microscope (STEM) to visualize lithium distributions. In the LiBC structure, boron and carbon are arranged to hetero graphite layers between which lithium is incorporated. The crystal structure is reflected in the PC-STEM images recorded perpendicular to the layers. The experimental images and their defocus dependence match with multi-slice simulations calculated utilizing the reciprocity principle. The observation that a part of the Li positions is not occupied is likely an effect of the intense electron beam triggering Li displacement. Copyright © 2013 Elsevier Ltd. All rights reserved.

Magnetic, electronic and optical properties of different graphene, BN and BC2N nanoribbons

NASA Astrophysics Data System (ADS)

Guerra, T.; Leite, L.; Azevedo, S.; de Lima Bernardo, B.

2017-04-01

Graphene nanoribbons are predicted to be essential components in future nanoelectronics. The size, edge type, form, arrangement of atoms and width of nanoribbons drastically change their properties. However, magnetic, electronic and optical properties of armchair, chevron and sawtooth of graphene, BN and BC2N nanoribbons are not fully understood so far. Here, we make use of first-principles calculations based on the density functional theory (DFT) to investigate the structural, magnetic, electronic and optical properties of nanoribbons of graphene, boron nitride and BC2N with armchair edge, chevron-type and sawtooth forms. The lowest formation energies were found for the armchair and chevron nanoribbons of graphene and boron nitride. We have shown that the imbalance of carbon atoms between different sublattices generates a net magnetic moment. Chevron-type nanoribbons of BC2N and graphene showed a band gap comparable with silicon, and a high light absorption in the visible spectrum when compared to the other configurations.

Towards Distributed Leadership as Standards-Based Practice in British Columbia

ERIC Educational Resources Information Center

Cherkowski, Sabre; Brown, Willow

2013-01-01

This narrative study of four BC principals was an initial investigation of distributed leadership using their provincial leadership standards as an organizing framework. The researchers invited participants to describe their understanding and practice of distributed leadership in terms of the Standards. Findings revealed three themes, or sets of…

Expression profile of BRCA1 and BRCA2 genes in premenopausal Mexican women with breast cancer: clinical and immunohistochemical correlates.

PubMed

Loredo-Pozos, Gloria; Chiquete, Erwin; Oceguera-Villanueva, Antonio; Panduro, Arturo; Siller-López, Fernando; Ramos-Márquez, Martha E

2009-01-01

Low BRCA1 gene expression is associated with increased invasiveness and influences the response of breast carcinoma (BC) to chemotherapeutics. However, expression of BRCA1 and BRCA2 genes has not been completely characterized in premenopausal BC. We analyzed the clinical and immunohistochemical correlates of BRCA1 and BRCA2 expression in young BC women. We studied 62 women (mean age 38.8 years) who developed BC before the age of 45 years. BRCA1 and BRCA2 mRNA expression was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) and that of HER-2 and p53 proteins by immunohistochemistry. Body mass index (BMI) > or = 27 (52%) and a declared family history of BC (26%) were the main risk factors. Ductal infiltrative adenocarcinoma was found in 86% of the cases (tumor size >5 cm in 48%). Disease stages I-IV occurred in 2, 40, 55, and 3%, respectively (73% implicating lymph nodes). Women aged < or = 35 years (24%) had more family history of cervical cancer, stage III/IV disease, HER-2 positivity, and lower BRCA1 expression than older women (P < 0.05). BRCA1 and BRCA2 expression correlated in healthy, but not in tumor tissues (TT). Neither BRCA1 nor BRCA2 expression was associated with tumor histology, differentiation, nodal metastasis or p53 and HER-2 expression. After multivariate analysis, only disease stage explained BRCA1 mRNA levels in the lowest quartile. Premenopausal BC has aggressive clinical and molecular characteristics. Low BRCA1 mRNA expression is associated mainly with younger ages and advanced clinical stage of premenopausal BC. BRCA2 expression is not associated with disease severity in young BC women.

A comparative DFT study on CO oxidation reaction over Si-doped BC2N nanosheet and nanotube

NASA Astrophysics Data System (ADS)

Nematollahi, Parisa; Neyts, Erik C.

2018-05-01

In this study, we performed density functional theory (DFT) calculations to investigate different reaction mechanisms of CO oxidation catalyzed by the Si atom embedded defective BC2N nanostructures as well as the analysis of the structural and electronic properties. The structures of all the complexes are optimized and characterized by frequency calculations at the M062X/6-31G∗ computational level. Also, The electronic structures and thermodynamic parameters of adsorbed CO and O2 molecules over Si-doped BC2N nanostructures are examined in detail. Moreover, to investigate the curvature effect on the CO oxidation reaction, all the adsorption and CO oxidation reactions on a finite-sized armchair (6,6) Si-BC2NNT are also studied. Our results indicate that there can be two possible pathways for the CO oxidation with O2 molecule: O2(g) + CO(g) → O2(ads) + CO(ads) → CO2(g) + O(ads) and O(ads) + CO(g) → CO2(g). The first reaction proceeds via the Langmuir-Hinshelwood (LH) mechanism while the second goes through the Eley-Rideal (ER) mechanism. On the other hand, by increasing the tube diameter, the energy barrier increases due to the strong adsorption energy of the O2 molecule which is related to its dissociation over the tube surface. Our calculations indicate that the two step energy barrier of the oxidation reaction over Si-BC2NNS is less than that over the Si-BC2NNT. Hence, Si-BC2NNS may serve as an efficient and highly activated substrate to CO oxidation rather than (4,4) Si-BC2NNT.

Quantifying Black Carbon emissions in high northern latitudes using an Atmospheric Bayesian Inversion

NASA Astrophysics Data System (ADS)

Evangeliou, Nikolaos; Thompson, Rona; Stohl, Andreas; Shevchenko, Vladimir P.

2016-04-01

Black carbon (BC) is the main light absorbing aerosol species and it has important impacts on air quality, weather and climate. The major source of BC is incomplete combustion of fossil fuels and the burning of biomass or bio-fuels (soot). Therefore, to understand to what extent BC affects climate change and pollutant dynamics, accurate knowledge of the emissions, distribution and variation of BC is required. Most commonly, BC emission inventory datasets are built by "bottom up" approaches based on activity data and emissions factors, but these methods are considered to have large uncertainty (Cao et al, 2006). In this study, we have used a Bayesian Inversion to estimate spatially resolved BC emissions. Emissions are estimated monthly for 2014 and over the domain from 180°W to 180°E and 50°N to 90°N. Atmospheric transport is modeled using the Lagrangian Particle Dispersion Model, FLEXPART (Stohl et al., 1998; 2005), and the inversion framework, FLEXINVERT, developed by Thompson and Stohl, (2014). The study domain is of particular interest concerning the identification and estimation of BC sources. In contrast to Europe and North America, where BC sources are comparatively well documented as a result of intense monitoring, only one station recording BC concentrations exists in the whole of Siberia. In addition, emissions from gas flaring by the oil industry have been geographically misplaced in most emission inventories and may be an important source of BC at high latitudes since a significant proportion of the total gas flared occurs at these high latitudes (Stohl et al., 2013). Our results show large differences with the existing BC inventories, whereas the estimated fluxes improve modeled BC concentrations with respect to observations. References Cao, G. et al. Atmos. Environ., 40, 6516-6527, 2006. Stohl, A. et al. Atmos. Environ., 32(24), 4245-4264, 1998. Stohl, A. et al. Atmos. Chem. Phys., 5(9), 2461-2474, 2005. Stohl, A. et al. Atmos. Chem. Phys., 13, 8833-8855, 2013. Thompson, R. L., and Stohl A. Geosci. Model Dev., 7, 2223-2242, 2014.

Quantifying the uncertainties of a bottom-up emission inventory of anthropogenic atmospheric pollutants in China

NASA Astrophysics Data System (ADS)

Zhao, Y.; Nielsen, C. P.; Lei, Y.; McElroy, M. B.; Hao, J.

2010-11-01

The uncertainties of a national, bottom-up inventory of Chinese emissions of anthropogenic SO2, NOx, and particulate matter (PM) of different size classes and carbonaceous species are comprehensively quantified, for the first time, using Monte Carlo simulation. The inventory is structured by seven dominant sectors: coal-fired electric power, cement, iron and steel, other industry (boiler combustion), other industry (non-combustion processes), transportation, and residential. For each parameter related to emission factors or activity-level calculations, the uncertainties, represented as probability distributions, are either statistically fitted using results of domestic field tests or, when these are lacking, estimated based on foreign or other domestic data. The uncertainties (i.e., 95% confidence intervals around the central estimates) of Chinese emissions of SO2, NOx, total PM, PM10, PM2.5, black carbon (BC), and organic carbon (OC) in 2005 are estimated to be -14%~12%, -10%~36%, -10%~36%, -12%~42% -16%~52%, -23%~130%, and -37%~117%, respectively. Variations at activity levels (e.g., energy consumption or industrial production) are not the main source of emission uncertainties. Due to narrow classification of source types, large sample sizes, and relatively high data quality, the coal-fired power sector is estimated to have the smallest emission uncertainties for all species except BC and OC. Due to poorer source classifications and a wider range of estimated emission factors, considerable uncertainties of NOx and PM emissions from cement production and boiler combustion in other industries are found. The probability distributions of emission factors for biomass burning, the largest source of BC and OC, are fitted based on very limited domestic field measurements, and special caution should thus be taken interpreting these emission uncertainties. Although Monte Carlo simulation yields narrowed estimates of uncertainties compared to previous bottom-up emission studies, the results are not always consistent with those derived from satellite observations. The results thus represent an incremental research advance; while the analysis provides current estimates of uncertainty to researchers investigating Chinese and global atmospheric transport and chemistry, it also identifies specific needs in data collection and analysis to improve on them. Strengthened quantification of emissions of the included species and other, closely associated ones - notably CO2, generated largely by the same processes and thus subject to many of the same parameter uncertainties - is essential not only for science but for the design of policies to redress critical atmospheric environmental hazards at local, regional, and global scales.

Quantifying the uncertainties of a bottom-up emission inventory of anthropogenic atmospheric pollutants in China

NASA Astrophysics Data System (ADS)

Zhao, Y.; Nielsen, C. P.; Lei, Y.; McElroy, M. B.; Hao, J.

2011-03-01

The uncertainties of a national, bottom-up inventory of Chinese emissions of anthropogenic SO2, NOx, and particulate matter (PM) of different size classes and carbonaceous species are comprehensively quantified, for the first time, using Monte Carlo simulation. The inventory is structured by seven dominant sectors: coal-fired electric power, cement, iron and steel, other industry (boiler combustion), other industry (non-combustion processes), transportation, and residential. For each parameter related to emission factors or activity-level calculations, the uncertainties, represented as probability distributions, are either statistically fitted using results of domestic field tests or, when these are lacking, estimated based on foreign or other domestic data. The uncertainties (i.e., 95% confidence intervals around the central estimates) of Chinese emissions of SO2, NOx, total PM, PM10, PM2.5, black carbon (BC), and organic carbon (OC) in 2005 are estimated to be -14%~13%, -13%~37%, -11%~38%, -14%~45%, -17%~54%, -25%~136%, and -40%~121%, respectively. Variations at activity levels (e.g., energy consumption or industrial production) are not the main source of emission uncertainties. Due to narrow classification of source types, large sample sizes, and relatively high data quality, the coal-fired power sector is estimated to have the smallest emission uncertainties for all species except BC and OC. Due to poorer source classifications and a wider range of estimated emission factors, considerable uncertainties of NOx and PM emissions from cement production and boiler combustion in other industries are found. The probability distributions of emission factors for biomass burning, the largest source of BC and OC, are fitted based on very limited domestic field measurements, and special caution should thus be taken interpreting these emission uncertainties. Although Monte Carlo simulation yields narrowed estimates of uncertainties compared to previous bottom-up emission studies, the results are not always consistent with those derived from satellite observations. The results thus represent an incremental research advance; while the analysis provides current estimates of uncertainty to researchers investigating Chinese and global atmospheric transport and chemistry, it also identifies specific needs in data collection and analysis to improve on them. Strengthened quantification of emissions of the included species and other, closely associated ones - notably CO2, generated largely by the same processes and thus subject to many of the same parameter uncertainties - is essential not only for science but for the design of policies to redress critical atmospheric environmental hazards at local, regional, and global scales.

Vertical profiles of black carbon measured by a micro-aethalometer in summer in the North China Plain

NASA Astrophysics Data System (ADS)

Ran, Liang; Deng, Zhaoze; Xu, Xiaobin; Yan, Peng; Lin, Weili; Wang, Ying; Tian, Ping; Wang, Pucai; Pan, Weilin; Lu, Daren

2016-08-01

Black carbon (BC) is a dominant absorber in the visible spectrum and a potent factor in climatic effects. Vertical profiles of BC were measured using a micro-aethalometer attached to a tethered balloon during the Vertical Observations of trace Gases and Aerosols (VOGA) field campaign, in summer 2014 at a semirural site in the North China Plain (NCP). The diurnal cycle of BC vertical distributions following the evolution of the mixing layer (ML) was investigated for the first time in the NCP region. Statistical parameters including identified mixing height (Hm) and average BC mass concentrations within the ML (Cm) and in the free troposphere (Cf) were obtained for a selected dataset of 67 vertical profiles. Hm was usually lower than 0.2 km in the early morning and rapidly rose thereafter due to strengthened turbulence. The maximum height of the ML was reached in the late afternoon. The top of a full developed ML exceeded 1 km on sunny days in summer, while it stayed much lower on cloudy days. The sunset triggered the collapse of the ML, and a stable nocturnal boundary layer (NBL) gradually formed. Accordingly, the highest level Cm was found in the early morning and the lowest was found in the afternoon. In the daytime, BC was almost uniformly distributed within the ML and significantly decreased above the ML. During the field campaign, Cm averaged about 5.16 ± 2.49 µg m-3, with a range of 1.12 to 14.49 µg m-3, comparable with observational results in many polluted urban areas such as Milan in Italy and Shanghai in China. As evening approached, BC gradually built up near the surface and exponentially declined with height. In contrast to the large variability found both in Hm and Cm, Cf stayed relatively unaffected through the day. Cf was less than 10 % of the ground level under clean conditions, while it amounted to half of the ground level in some polluted cases. In situ measurements of BC vertical profiles would hopefully have an important implication for accurately estimating direct radiative forcing by BC and improving the retrieval of aerosol optical properties by remote sensing in this region.

Grey Tienshan Urumqi Glacier No.1 and light-absorbing impurities.

PubMed

Ming, Jing; Xiao, Cunde; Wang, Feiteng; Li, Zhongqin; Li, Yamin

2016-05-01

The Tienshan Urumqi Glacier No.1 (TUG1) usually shows "grey" surfaces in summers. Besides known regional warming, what should be responsible for largely reducing its surface albedo and making it look "grey"? A field campaign was conducted on the TUG1 on a selected cloud-free day of 2013 after a snow fall at night. Fresh and aged snow samples were collected in the field, and snow densities, grain sizes, and spectral reflectances were measured. Light-absorbing impurities (LAIs) including black carbon (BC) and dust, and number concentrations and sizes of the insoluble particles (IPs) in the samples were measured in the laboratory. High temperatures in summer probably enhanced the snow ageing. During the snow ageing process, the snow density varied from 243 to 458 kg m(-3), associated with the snow grain size varying from 290 to 2500 μm. The concentrations of LAIs in aged snow were significantly higher than those in fresh snow. Dust and BC varied from 16 ppm and 25 ppb in fresh snow to 1507 ppm and 1738 ppb in aged snow, respectively. Large albedo difference between the fresh and aged snow suggests a consequent forcing of 180 W m(-2). Simulations under scenarios show that snow ageing, BC, and dust were responsible for 44, 25, and 7 % of the albedo reduction in the accumulation zone, respectively.

Sources of black carbon aerosols in South Asia and surrounding regions during the Integrated Campaign for Aerosols, Gases and Radiation Budget (ICARB)

DOE PAGES

Kumar, R.; Barth, M. C.; Nair, V. S.; ...

2015-05-19

This study examines differences in the surface black carbon (BC) aerosol loading between the Bay of Bengal (BoB) and the Arabian Sea (AS) and identifies dominant sources of BC in South Asia and surrounding regions during March–May 2006 (Integrated Campaign for Aerosols, Gases and Radiation Budget, ICARB) period. A total of 13 BC tracers are introduced in the Weather Research and Forecasting Model coupled with Chemistry to address these objectives. The model reproduced the temporal and spatial variability of BC distribution observed over the AS and the BoB during the ICARB ship cruise and captured spatial variability at the inlandmore » sites. In general, the model underestimates the observed BC mass concentrations. However, the model–observation discrepancy in this study is smaller compared to previous studies. Model results show that ICARB measurements were fairly well representative of the AS and the BoB during the pre-monsoon season. Elevated BC mass concentrations in the BoB are due to 5 times stronger influence of anthropogenic emissions on the BoB compared to the AS. Biomass burning in Burma also affects the BoB much more strongly than the AS. Results show that anthropogenic and biomass burning emissions, respectively, accounted for 60 and 37% of the average ± standard deviation (representing spatial and temporal variability) BC mass concentration (1341 ± 2353 ng m -3) in South Asia. BC emissions from residential (61%) and industrial (23%) sectors are the major anthropogenic sources, except in the Himalayas where vehicular emissions dominate. We find that regional-scale transport of anthropogenic emissions contributes up to 25% of BC mass concentrations in western and eastern India, suggesting that surface BC mass concentrations cannot be linked directly to the local emissions in different regions of South Asia.« less

Exploiting simultaneous observational constraints on mass and absorption to estimate the global direct radiative forcing of black carbon and brown carbon

NASA Astrophysics Data System (ADS)

Wang, X.; Heald, C. L.; Ridley, D. A.; Schwarz, J. P.; Spackman, J. R.; Perring, A. E.; Coe, H.; Liu, D.; Clarke, A. D.

2014-06-01

Atmospheric black carbon (BC) is a leading climate warming agent, yet uncertainties on the global direct radiative forcing (DRF) remain large. Here we expand a global model simulation (GEOS-Chem) of BC to include the absorption enhancement associated with BC coating and separately treat both the aging and physical properties of fossil fuel and biomass burning BC. In addition we develop a global simulation of Brown Carbon (BrC) from both secondary (aromatic) and primary (biomass burning and biofuel) sources. The global mean lifetime of BC in this simulation (4.4 days) is substantially lower compared to the AeroCom I model means (7.3 days), and as a result, this model captures both the mass concentrations measured in near-source airborne field campaigns (ARCTAS, EUCAARI) and surface sites within 30%, and in remote regions (HIPPO) within a factor of two. We show that the new BC optical properties together with the inclusion of BrC reduces the model bias in Absorption Aerosol Optical Depth (AAOD) at multiple wavelengths by more than 50% at AERONET sites worldwide. However our improved model still underestimates AAOD by a factor of 1.4 to 2.8 regionally, with largest underestimates in regions influenced by fire. Using the RRTMG model integrated with GEOS-Chem we estimate that the all-sky top-of-atmosphere DRF of BC is +0.13 W m-2 (0.08 W m-2 from anthropogenic sources and 0.05 W m-2 from biomass burning). If we scale our model to match AERONET AAOD observations we estimate the DRF of BC is +0.21 W m-2, with an additional +0.11 W m-2 of warming from BrC. Uncertainties in size, optical properties, observations, and emissions suggest an overall uncertainty in BC DRF of -80% / +140%. Our estimates are at the lower end of the 0.2-1.0 W m-2 range from previous studies, and substantially less than the +0.6 W m-2 DRF estimated in the IPCC 5th Assessment Report. We suggest that the DRF of BC has previously been overestimated due to the overestimation of the BC lifetime and the incorrect attribution of BrC absorption to BC.

Exploiting simultaneous observational constraints on mass and absorption to estimate the global direct radiative forcing of black carbon and brown carbon

NASA Astrophysics Data System (ADS)

Wang, X.; Heald, C. L.; Ridley, D. A.; Schwarz, J. P.; Spackman, J. R.; Perring, A. E.; Coe, H.; Liu, D.; Clarke, A. D.

2014-10-01

Atmospheric black carbon (BC) is a leading climate warming agent, yet uncertainties on the global direct radiative forcing (DRF) remain large. Here we expand a global model simulation (GEOS-Chem) of BC to include the absorption enhancement associated with BC coating and separately treat both the aging and physical properties of fossil-fuel and biomass-burning BC. In addition we develop a global simulation of brown carbon (BrC) from both secondary (aromatic) and primary (biomass burning and biofuel) sources. The global mean lifetime of BC in this simulation (4.4 days) is substantially lower compared to the AeroCom I model means (7.3 days), and as a result, this model captures both the mass concentrations measured in near-source airborne field campaigns (ARCTAS, EUCAARI) and surface sites within 30%, and in remote regions (HIPPO) within a factor of 2. We show that the new BC optical properties together with the inclusion of BrC reduces the model bias in absorption aerosol optical depth (AAOD) at multiple wavelengths by more than 50% at AERONET sites worldwide. However our improved model still underestimates AAOD by a factor of 1.4 to 2.8 regionally, with the largest underestimates in regions influenced by fire. Using the RRTMG model integrated with GEOS-Chem we estimate that the all-sky top-of-atmosphere DRF of BC is +0.13 Wm-2 (0.08 Wm-2 from anthropogenic sources and 0.05 Wm-2 from biomass burning). If we scale our model to match AERONET AAOD observations we estimate the DRF of BC is +0.21 Wm-2, with an additional +0.11 Wm-2 of warming from BrC. Uncertainties in size, optical properties, observations, and emissions suggest an overall uncertainty in BC DRF of -80%/+140%. Our estimates are at the lower end of the 0.2-1.0 Wm-2 range from previous studies, and substantially less than the +0.6 Wm-2 DRF estimated in the IPCC 5th Assessment Report. We suggest that the DRF of BC has previously been overestimated due to the overestimation of the BC lifetime (including the effect on the vertical profile) and the incorrect attribution of BrC absorption to BC.

Time-resolved measurements of black carbon light absorption enhancement in urban and near-urban locations of Southern Ontario, Canada

NASA Astrophysics Data System (ADS)

Chan, T. W.; Brook, J. R.; Smallwood, G. J.; Lu, G.

2010-08-01

In this study a photoacoustic spectrometer (PA), a laser-induced incandescence instrument system (LII) and an aerosol mass spectrometer were operated in parallel for in situ measurements of black carbon (BC) light absorption enhancement. Results of a thermodenuder experiment using ambient particles in Toronto are presented first to show that LII measurements of BC are not influenced by particle coating while the PA response is enhanced and also that the nature of this enhancement is influenced by particle morphology. Comparisons of ambient PA and LII measurements at four different locations (suburban Toronto; a street canyon with heavy diesel bus traffic in Ottawa; adjacent to a commuter highway in Ottawa and; regional background air in and around Windsor, Ontario), show that the different meteorological conditions and atmospheric processes result in different particle light absorption enhancement and hence the specific attenuation coefficient (SAC). Depending upon location of measurement and the BC spherule diameter (primary particle size - PPS) measurement from the LII, the SAC varies from 2.6±0.04 to 22.5±0.7 m2 g-1. Observations from this study also show the active surface area of the BC aggregate, inferred from PPS, is an important parameter for inferring the degree of particle collapse of a BC particle. The predictability of the overall BC light absorption enhancement in the atmosphere depends not only on the coating mass but also on the source of the BC and on our ability to predict or measure the change in particle morphology as particles evolve.

Distribution and clinical determinants of time-to-positivity of blood cultures in patients with neutropenia.

PubMed

Lambregts, Merel M C; Warreman, Eva B; Bernards, Alexandra T; Veelken, Hendrik; von dem Borne, Peter A; Dekkers, Olaf M; Visser, Leo G; de Boer, Mark G

2018-02-01

Blood cultures (BCs) are essential in the evaluation of neutropenic fever. Modern BC systems have significantly reduced the time-to-positivity (TTP) of BC. This study explores the probability of bacteraemia when BCs have remained negative for different periods of time. All adult patients with neutropenia and bacteraemia were included (January 2012-February 2016). Predictive clinical factors for short (≤16 hours) and long (>24 hours) TTP were determined. The residual probability of bacteraemia was estimated for the scenario of negative BC 24 hours after collection. The cohort consisted of 154 patients, accounting for 190 episodes of bacteraemia. Median age of 61 years, 60.5% were male. In 123 (64.7%) episodes, BC yielded a single Gram-positive micro-organism and in 49 (25.8%) a Gram-negative micro-organism (median TTP 16.7, 14.5 hours respectively, P < .01). TTP was ≤24 hours in 91.6% of episodes. Central line-associated bacteraemia was associated with long TTP. The probability of bacteraemia if BC had remained negative for 24 hours was 1%-3%. The expected TTP offers guidance in the management of patients with neutropenia and suspected bacteraemia. The knowledge of negative BC can support a change in working diagnosis, and impact clinical decisions as soon as 24 hours after BC collection. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Parametric modelling of cost data in medical studies.

PubMed

Nixon, R M; Thompson, S G

2004-04-30

The cost of medical resources used is often recorded for each patient in clinical studies in order to inform decision-making. Although cost data are generally skewed to the right, interest is in making inferences about the population mean cost. Common methods for non-normal data, such as data transformation, assuming asymptotic normality of the sample mean or non-parametric bootstrapping, are not ideal. This paper describes possible parametric models for analysing cost data. Four example data sets are considered, which have different sample sizes and degrees of skewness. Normal, gamma, log-normal, and log-logistic distributions are fitted, together with three-parameter versions of the latter three distributions. Maximum likelihood estimates of the population mean are found; confidence intervals are derived by a parametric BC(a) bootstrap and checked by MCMC methods. Differences between model fits and inferences are explored.Skewed parametric distributions fit cost data better than the normal distribution, and should in principle be preferred for estimating the population mean cost. However for some data sets, we find that models that fit badly can give similar inferences to those that fit well. Conversely, particularly when sample sizes are not large, different parametric models that fit the data equally well can lead to substantially different inferences. We conclude that inferences are sensitive to choice of statistical model, which itself can remain uncertain unless there is enough data to model the tail of the distribution accurately. Investigating the sensitivity of conclusions to choice of model should thus be an essential component of analysing cost data in practice. Copyright 2004 John Wiley & Sons, Ltd.

Biochar derived from corn straw affected availability and distribution of soil nutrients and cotton yield.

PubMed

Tian, Xiaofei; Li, Chengliang; Zhang, Min; Wan, Yongshan; Xie, Zhihua; Chen, Baocheng; Li, Wenqing

2018-01-01

Biochar application as a soil amendment has been proposed as a strategy to improve soil fertility and increase crop yields. However, the effects of successive biochar applications on cotton yields and nutrient distribution in soil are not well documented. A three-year field study was conducted to investigate the effects of successive biochar applications at different rates on cotton yield and on the soil nutrient distribution in the 0-100 cm soil profile. Biochar was applied at 0, 5, 10, and 20 t ha-1 (expressed as Control, BC5, BC10, and BC20, respectively) for each cotton season, with identical doses of chemical fertilizers. Biochar enhanced the cotton lint yield by 8.0-15.8%, 9.3-13.9%, and 9.2-21.9% in 2013, 2014, and 2015, respectively, and high levels of biochar application achieved high cotton yields each year. Leaching of soil nitrate was reduced, while the pH values, soil organic carbon, total nitrogen (N), and available K content of the 0-20 cm soil layer were increased in 2014 and 2015. However, the changes in the soil available P content were less substantial. This study suggests that successive biochar amendments have the potential to enhance cotton productivity and soil fertility while reducing nitrate leaching.

Measurement of non-volatile particle number size distribution

NASA Astrophysics Data System (ADS)

Gkatzelis, G. I.; Papanastasiou, D. K.; Florou, K.; Kaltsonoudis, C.; Louvaris, E.; Pandis, S. N.

2015-06-01

An experimental methodology was developed to measure the non-volatile particle number concentration using a thermodenuder (TD). The TD was coupled with a high-resolution time-of-flight aerosol mass spectrometer, measuring the chemical composition and mass size distribution of the submicrometer aerosol and a scanning mobility particle sizer (SMPS) that provided the number size distribution of the aerosol in the range from 10 to 500 nm. The method was evaluated with a set of smog chamber experiments and achieved almost complete evaporation (> 98 %) of secondary organic as well as freshly nucleated particles, using a TD temperature of 400 °C and a centerline residence time of 15 s. This experimental approach was applied in a winter field campaign in Athens and provided a direct measurement of number concentration and size distribution for particles emitted from major pollution sources. During periods in which the contribution of biomass burning sources was dominant, more than 80 % of particle number concentration remained after passing through the thermodenuder, suggesting that nearly all biomass burning particles had a non-volatile core. These remaining particles consisted mostly of black carbon (60 % mass contribution) and organic aerosol, OA (40 %). Organics that had not evaporated through the TD were mostly biomass burning OA (BBOA) and oxygenated OA (OOA) as determined from AMS source apportionment analysis. For periods during which traffic contribution was dominant 50-60 % of the particles had a non-volatile core while the rest evaporated at 400 °C. The remaining particle mass consisted mostly of black carbon (BC) with an 80 % contribution, while OA was responsible for another 15-20 %. Organics were mostly hydrocarbon-like OA (HOA) and OOA. These results suggest that even at 400 °C some fraction of the OA does not evaporate from particles emitted from common combustion processes, such as biomass burning and car engines, indicating that a fraction of this type of OA is of extremely low volatility.

Negative feedback regulation of Homer 1a on norepinephrine-dependent cardiac hypertrophy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiarello, Carmelina; Bortoloso, Elena; Carpi, Andrea

2013-07-15

Homers are scaffolding proteins that modulate diverse cell functions being able to assemble signalling complexes. In this study, the presence, sub-cellular distribution and function of Homer 1 was investigated. Homer 1a and Homer 1b/c are constitutively expressed in cardiac muscle of both mouse and rat and in HL-1 cells, a cardiac cell line. As judged by confocal immunofluorescence microscopy, Homer 1a displays sarcomeric and peri-nuclear localization. In cardiomyocytes and cultured HL-1 cells, the hypertrophic agonist norepinephrine (NE) induces α{sub 1}-adrenergic specific Homer 1a over-expression, with a two-to-three-fold increase within 1 h, and no up-regulation of Homer 1b/c, as judged bymore » Western blot and qPCR. In HL-1 cells, plasmid-driven over-expression of Homer 1a partially antagonizes activation of ERK phosphorylation and ANF up-regulation, two well-established, early markers of hypertrophy. At the morphometric level, NE-induced increase of cell size is likewise and partially counteracted by exogenous Homer 1a. Under the same experimental conditions, Homer 1b/c does not have any effect on ANF up-regulation nor on cell hypertrophy. Thus, Homer 1a up-regulation is associated to early stages of cardiac hypertrophy and appears to play a negative feedback regulation on molecular transducers of hypertrophy. -- Highlights: • Homer 1a is constitutively expressed in cardiac tissue. • In HL-1 cells, norepinephrine activates signaling pathways leading to hypertrophy. • Homer 1a up-regulation is an early event of norepinephrine-induced hypertrophy. • Homer 1a plays a negative feedback regulation modulating pathological hypertrophy. • Over-expression of Homer 1a per se does not induce hypertrophy.« less

{sup 25}Na and {sup 25}Mg fragmentation on {sup 12}C at 9.23 MeV per nucleon at TRIUMF

DOE Office of Scientific and Technical Information (OSTI.GOV)

St-Onge, Patrick; Boisjoli, Mark; Fregeau, Marc-Olivier

2012-10-20

HERACLES is a multidetector that is used to study heavy-ion collisions, with ion beams with an energy range between 8 to 15 MeV per nucleon. It has 78 detectors axially distributed around the beam axis in 6 rings allowing detection of multiple charged fragments from nuclear reactions. HERACLES has 4 different types of detectors, BC408/BaF{sub 2} phoswich, Si/CsI(Tl) telescope, BC408/BC444 phoswich and CsI(Tl) detectors. The multidetector has been run with a radioactive {sup 25}Na beam and a stable {sup 25}Mg beam at 9.23 MeV per nucleon on a carbon target.

Temporal variation of aqueous-extractable Ca, Mg and K in acidified forest mountainous soils under different vegetation cover

NASA Astrophysics Data System (ADS)

Tejnecky, V.; Bradová, M.; Boruvka, L.; Vasat, R.; Nemecek, K.; Ash, C.; Sebek, O.; Rejzek, J.; Drabek, O.

2012-12-01

Acidification of forest soils is a natural degradation process which can be significantly enhanced by anthropogenic activities. Inputs of basic cations (BC - Ca, Mg and K) via precipitation, litter and soil organic matter decomposition and also via inter-soil weathering may partially mitigate the consequences of this degradation process. The aim of this study is to assess the temporal variation of aqueous-extractable Ca, Mg and K in acidified forest mountainous soils under different vegetation cover. The Jizera Mountains region (Czech Republic, northern Bohemia) was chosen as a representative soil mountainous ecosystem strongly affected by acidification. Soil and precipitation samples were collected at monthly basis from April till October/ November during the years 2009-2011. Study spots were delimited under two contrasting vegetation covers - beech and spruce monoculture. Prevailing soil types were classified as Alumic Cambisols under beech and Entic Podzols under spruce stands (according to FAO classification). Soil samples were collected from surface fermentation (F) and humified (H) organic horizons and subsurface B horizons (cambic or spodic). The collected soil samples were analyzed immediately under laboratory condition in a "fresh" state. Unsieved fresh samples were extracted by deionised water. The content of main elements (Ca, Mg, K, Al and Fe) was determined by ICP-OES. The content of major anions (SO42-, NO3-, Cl- and F-) was determined by ion-exchange chromatography (IC). Content of major anions and main elements were determined in the precipitation samples (throughfall, stemflow and bulk) as well. Besides computing the basic statistical parameters (mean, median, variance, maximum, minimum, etc.) we also employed other statistical methods such as T-test and ANOVA to assess the differences between beech and spruce vegetation spots. To carry out the temporal variability in the data we used the time series analysis and short-term forecasting by Holt-Winters exponential smoothing and ARIMA models. Our results clearly exhibit differences in the horizontal and spatial distribution of BC. The influences of the study spot, i.e. the influence of stand factors e.g. vegetation covers on BC distribution are well pronounced. The highest amounts of aqueous extractable BC were identified in the F and H organic horizons. The contents of Ca and Mg were significantly higher under beech cover than under spruce cover. The influence of seasonality on BC content and distribution was the strongest in the upper organic horizons. The annual changes are less pronounced in inner mineral B horizons. We have observed a significant influence of the snow melting period - after this event the content of BC was the lowest. In contrast, the BC content rises during the summer period - the time of high biological activity and accelerated organic matter decomposition. This period is again followed by a BC content decrease during the fall period - the time of gradually decreasing biological activity and high precipitation. Generally, we can conclude that the seasonal variations are higher than annual and spatial for both sites.

Metric substage according to micro and extensive lamina propria invasion improves prognostics in T1 bladder cancer.

PubMed

Fransen van de Putte, Elisabeth E; Otto, Wolfgang; Hartmann, Arndt; Bertz, Simone; Mayr, Roman; Bründl, Johannes; Breyer, Johannes; Manach, Quentin; Compérat, Eva M; Boormans, Joost L; Bosschieter, Judith; Jewett, Michael A S; Stoehr, Robert; van Leenders, Geert J L H; Nieuwenhuijzen, Jakko A; Zlotta, Alexandre R; Hendricksen, Kees; Rouprêt, Morgan; Burger, Maximilian; van der Kwast, Theo H; van Rhijn, Bas W G

2018-06-04

Reliable prognosticators for T1 bladder cancer (T1BC) are urgently needed. To compare the prognostic value of 2 substage systems for T1BC in patients treated by transurethral resection (TUR) and adjuvant bacillus Calmette-Guérin therapy. The slides of 601 primary T1BCs from four institutes were reviewed by 2 uropathologists and substaged according to 2 classifications: metric substage according to T1 microinvasive (T1m-lamina propria invasion <0.5mm) and T1 extensive invasive (pT1e-invasion ≥ 0.5mm), and according to invasion of the muscularis mucosae (MM) (T1a-invasion above or into MM/T1b). Multivariable analyses for progression-free (PFS) and cancer-specific survival (CSS) were performed including substage, size, multiplicity, carcinoma in situ, sex, age, WHO-grade 1973, and WHO-grade 2004 as variables. Median follow-up was 5.9 years (interquartile range: 3.3-9.0). Progression to T2BC was observed in 148 (25%) patients and 94 (16%) died of BC. The MM was not present at the invasion front in 135 (22%) of tumors. Slides were substaged as follows: 213 T1m and 388 T1e and 281 T1a and 320 T1b. On multivariable analysis, T1m/e substage and WHO 1973 grade were the strongest prognosticators for PFS (hazard ratio [HR] = 3.8 and HR = 1.8) and CSS (HR = 2.7 and HR = 2.6), respectively. Other prognostic factors for CSS were age (HR = 1.03), and tumor size (HR = 1.8). Substage according to MM-invasion was not significant. Our study was limited by its retrospective design and that standard re-TUR was not performed if TUR was macroscopically complete and muscularis propria was present in resected specimens. Metric substaging of T1BC was possible in all cases of 601 T1BC patients and it was a strong independent prognosticator of both PFS and CSS. Copyright © 2018 Elsevier Inc. All rights reserved.

Role of the blocking capacitor in control of ion energy distributions in pulsed capacitively coupled plasmas sustained in Ar/CF{sub 4}/O{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Sang-Heon, E-mail: ssongs@umich.edu; Kushner, Mark J., E-mail: mjkush@umich.edu

2014-03-15

In plasma etching for microelectronics fabrication, the quality of the process is in large part determined by the ability to control the ion energy distribution (IED) onto the wafer. To achieve this control, dual frequency capacitively coupled plasmas (DF-CCPs) have been developed with the goal of separately controlling the magnitude of the fluxes of ions and radicals with the high frequency (HF) and the shape of the IED with the low frequency (LF). In steady state operation, plasma properties are determined by a real time balance between electron sources and losses. As such, for a given geometry, pressure, and frequencymore » of operation, the latitude for controlling the IED may be limited. Pulsed power is one technique being investigated to provide additional degrees of freedom to control the IED. In one configuration of a DF-CCP, the HF power is applied to the upper electrode and LF power is applied to the lower electrode which is serially connected to a blocking capacitor (BC) which generates a self dc-bias. In the steady state, the value of the dc-bias is, in fact, constant. During pulsed operation, however, there may be time modulation of the dc-bias which provides an additional means to control the IED. In this paper, IEDs to the wafer in pulsed DF-CCPs sustained in Ar/CF{sub 4}/O{sub 2} are discussed with results from a two-dimensional plasma hydrodynamics model. The IED can be manipulated depending on whether the LF or HF power is pulsed. The dynamic range of the control can be tuned by the dc-bias generated on the substrate, whose time variation depends on the size of the BC during pulsed operation. It was found that high energy ions can be preferentially produced when pulsing the HF power and low energy ions are preferentially produced when pulsing the LF power. A smaller BC value which allows the bias to follow the change in charged particle fluxes produces a larger dynamic range with which to control IEDs.« less

Seasonal and interannual variations in CO and BC emissions from open biomass burning in Southern Africa during 1998-2005

NASA Astrophysics Data System (ADS)

Ito, Akinori; Ito, Akihiko; Akimoto, Hajime

2007-06-01

We estimate the emissions of carbon monoxide (CO) and black carbon (BC) from open vegetation fires in the Southern Hemisphere Africa from 1998 to 2005 using satellite information in conjunction with a biogeochemical model. Monthly burned areas at a 0.5-degree resolution are estimated from the Visible InfraRed Scanner (VIRS) fire count product and the MODerate resolution Imaging Spectroradiometer (MODIS) burned area data set associated with the MODIS tree cover imagery in grasslands and woodlands. The monthly fuel load distributions are derived from a 0.5-degree terrestrial carbon cycle model in conjunction with satellite data. The monthly maps of combustion factors and emission factors are estimated using empirical models that predict the effects of fuel conditions on these factors in grasslands and woodlands. Our annually averaged effective CO and BC emissions per area burned are 27 g CO m-2 and 0.17 g BC m-2 which are consistent with the products of fuel consumption and emission factors typically measured in southern Africa. The CO and BC emissions from open vegetation burning in southern Africa range from 45 Tg CO yr-1 and 0.26 Tg BC yr-1 for 2002 to 75 Tg CO yr-1 and 0.42 Tg BC yr-1 for 1998. The monthly averaged burned areas from VIRS fire counts peak earlier than modeled CO emissions. This characteristic delay between burned areas and emissions is mainly explained by significant changes in combustion factors for woodlands in our model. Consequently, the peaks in CO and BC emissions from our bottom-up approach are identical to those from previous top-down estimates using the Measurement Of the Pollution In The Troposphere (MOPITT) and the Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI) data.

Broad-Range PCR Coupled with Electrospray Ionization Time of Flight Mass Spectrometry for Detection of Bacteremia and Fungemia in Patients with Neutropenic Fever

PubMed Central

Maertens, J.; Bueselinck, K.; Lagrou, K.

2016-01-01

Infection is an important complication in patients with hematologic malignancies or solid tumors undergoing intensive cytotoxic chemotherapy. In only 20 to 30% of the febrile neutropenic episodes, an infectious agent is detected by conventional cultures. In this prospective study, the performance of broad-range PCR coupled with electrospray ionization time of flight mass spectrometry (PCR/ESI-MS) technology was compared to conventional blood cultures (BC) in a consecutive series of samples from high-risk hematology patients. In 74 patients, BC and a whole-blood sample for PCR/ESI-MS (Iridica BAC BSI; Abbott, Carlsbad, CA, USA) were collected at the start of each febrile neutropenic episode and, in case of persistent fever, also at day 5. During 100 different febrile episodes, 105 blood samples were collected and analyzed by PCR/ESI-MS. There was evidence of a bloodstream infection (BSI) in 36/105 cases (34%), based on 14 cases with both PCR/ESI-MS and BC positivity, 17 cases with BC positivity only, and 5 cases with PCR/ESI-MS positivity only. The sensitivity of PCR/ESI-MS was 45%, specificity was 93%, and the negative predictive value was 80% compared to blood culture. PCR/ESI-MS detected definite pathogens (Fusobacterium nucleatum and Streptococcus pneumoniae) missed by BC, whereas it missed both Gram-negative and Gram-positive organisms detected by BC. PCR/ESI-MS testing detected additional microorganisms but showed a low sensitivity (45%) compared to BC in neutropenic patients. Our results indicate a lower concordance between BC and PCR/ESI-MS in the neutropenic population than what has been previously reported in other patient groups with normal white blood cell distribution, and a lower sensitivity than other PCR-based methods. PMID:27440820

Quasi-two-body decays Bc → D(s)[ρ(770),ρ(1450),ρ(1700)→]ππ in the perturbative QCD factorization approach

NASA Astrophysics Data System (ADS)

Ma, Ai-Jun; Li, Ya; Xiao, Zhen-Jun

2018-01-01

In this paper, we studied the quasi-two-body Bc →D(s) [ ρ (770) , ρ (1450) , ρ (1700) → ] ππ decays by employing the perturbative QCD (PQCD) factorization approach. The two-pion distribution amplitudes Φππ are applied to include the final-state interactions between the pion pair, while the time-like form factors Fπ (w2) associated with the P-wave resonant states ρ (770), ρ (1450) and ρ (1700) are extracted from the experimental data of the e+e- annihilation. We found that: (a) the PQCD predictions for the branching ratios of the quasi-two-body Bc →D(s) [ ρ (770) , ρ (1450) , ρ (1700) → ] ππ decays are in the order of 10-9 to 10-5 and the direct CP violations around (10 - 40)% in magnitude; (b) the two sets of the large hierarchy R 1 a , 1 b , 1 c and R 2 a , 2 b , 2 c for the ratios of the branching ratios of the considered decays are defined and can be understood in the PQCD factorization approach, while the self-consistency between the quasi-two-body and two-body framework for Bc →D(s) [ ρ (770) → ] ππ and Bc →D(s) ρ (770) decays are confirmed by our numerical results; (c) taking currently known B (ρ (1450) → ππ) and B (ρ (1700) → ππ) as input, we extracted the theoretical predictions for B (Bc → Dρ (1450)) and B (Bc → Dρ (1700)) from the PQCD predictions for the decay rates of the quasi-two-body decays Bc → D [ ρ (1450) , ρ (1700) → ] ππ. All the PQCD predictions will be tested in the future experiments.

Brown carbon in fresh and aged biomass burning emissions

NASA Astrophysics Data System (ADS)

Saleh, R.; Robinson, E.; Tkacik, D. S.; Ahern, A.; Liu, S.; Aiken, A. C.; Sullivan, R. C.; Presto, A. A.; Dubey, M.; Donahue, N. M.; Robinson, A. L.

2013-12-01

To date, most climate forcing calculations treat black carbon (BC) and dust as the only particulate light absorbers. Numerous studies have shown that some organic aerosols (OA), referred to as brown carbon (BrC), also absorb light. BrC has been identified in biomass burning emissions; however, its light absorption properties are poorly constrained. Literature values of the imaginary part of the refractive indices of biomass burning OA (kOA) span two orders of magnitude. This variability, attributed to differences in fuel type and burning conditions, complicates the representation of biomass burning BrC in climate models. Proper accounting for BrC absorption in climate forcing calculations is of great importance. It can enhance the models' performance, bringing estimates of climate sensitivity to better agreement with observations. Here, we investigate the source of variability in absorptivity of biomass-burning OA observed in this study. We show that absorptivity is closely linked to OA volatility. Specifically, low-volatility organic compounds (LVOCs) are responsible for most of the light absorption, with effective kOA 1-2 orders of magnitude greater than the semi-volatile organic compounds (SVOCs). The effective kOA of biomass-burning emissions thus depends on the extent to which SVOCs partition to the condensed phase, which is sensitive to OA loading. kOA increases by a factor of 3-4 when the emissions are diluted from source concentrations (1-10 mg/m3) to atmospheric-like concentrations (1-10 μg/m3), as the partitioning of SVOCs shifts towards the gas phase. More importantly, we demonstrate that the effective kOA depends largely on burn conditions, and not fuel type. Burns which produce high levels of BC emit OA that is more absorptive than burns which produce low levels of BC. The dependence of kOA on OA loading and burn conditions can be parameterized as a function of a single property of the emissions, namely the BC-to-OA ratio. Specifically, kOA at wavelength (lambda) of 550 nm increases linearly with the BC-to-OA ratio, while the spectral-dependence, w, where k¬OA = kOA,550nm*(550/lambda)w, is inversely proportional to the BC-to-OA ratio. These correlations were determined by examining emissions from small scale laboratory burns of six globally relevant fuels (black spruce, ponderosa pine, hay, rice straw, saw grass, and wire grass), assuming that their behavior can be extrapolated to other biomass fuels. Experiments were conducted during the Fire Laboratory at Missoula Campaign (FLAME 4). The BC-to-OA ratios in the experiments were between 0.01 and 0.2. Aging of the emissions (photo-oxidation or dark ozonolysis) was performed in a smog chamber. To determine the dependence of absorptivity on volatility, the SVOCs were stripped from the condensed phase by heating the emissions to 250 C inside a thermodenuder. This allowed for constraining the optical properties of the low-volatility residue. kOA values were retrieved by performing optical closure, which combines Mie theory calculations with measurements of light absorption, and total and BC size distributions.

Characteristics of Aerosols over the Garhwal Himalayas: India

NASA Astrophysics Data System (ADS)

Soni, A.; Panwar, P.; Sundriyal, S.; Prabhu, V.; Shridhar, V.

2017-12-01

Aerosols and Black Carbon (BC) is very important pollutants in context of global warming study. Due to high spatio-temporal variation in aerosols, there is a large uncertainty in climate change study. This study was conducted to understand the particulate pollution level in different altitude ranging from 300 m AMSL to 2600 m AMSL (see fig.). In this study eight different sizes of aerosols (10 µm to 0.43 µm) concentration along with BC measured during summer season (MJJ) of 2014-2016 over 5 different locations of Garhwal Himalayas using Anderson Cascade Impactor (ACI) and Aethalometer AE-33. Sampling was performed continuously for 15-20 days at each site. It is the preliminary study to understand the sources of aerosols. Further chemical analysis of different sizes of aerosols helps to identify sources accurately. It will also help in future policies implications. High altitude site i.e. at 2600 m was very close to the Gangotri Glacier where river Ganga originates. The Ganga is one of the most important river in India, millions people rely on the water of this river. Since last decade many catastrophic events happened in this region because of melting of glacier fastly. Previously, no one studies BC and aerosols over this important fragile landscape. BC concentration was ranging from 4.72 ± 5.64 µg m-3 to 15.06 ± 7.69 µg m-3 at 2600 m to 300 m AMSL. At high altitude site highest aerosol concentration was observed to be 56.43 µg m-3 on the size range of PM3.3-4.7. During April-May there was a big fire event (around 3500 hector forest burnt) and the sampling period at 2600 m was on May. So that, to understand transportation of aerosols from forest fire region backward trajectories were calculated using HYSPLIT model. It gives evidence that during summer months aerosols transported from neighbouring forest fire area. While the concentration at lowest altitude was observed to be 248.95 µg m-3 in the size range of PM9-10 which is much higher than the permissible limit of PM10. This site is situated in foothills of Shivalik ranges and it surrounded by industries.

Assessment of Residential Biomass Burning During Winter in Las Vegas, Nevada

NASA Astrophysics Data System (ADS)

Brown, S. G.; Lee, T.; Olson, D.; Norris, G.; Roberts, P. T.; Collett, J. L.

2011-12-01

Concentrations of organic matter (OM) and black carbon (BC) were measured at a site in a residential area of Las Vegas, Nevada, and multiple analytical methods were used to determine the amounts attributable to biomass burning. In January 2008, measurements of a wood burning tracer, levoglucosan, were made via gas chromatography-mass spectroscopy (n=17). In addition, an Aerodyne High Resolution Aerosol Mass Spectrometer (HR-AMS) measured OM and C2H4O2+, a levoglucosan-derived fragment. During 2007 and 2008, two-channel Aethalometer data were also collected; the difference between the 370 nm and 880 nm channels (UV-BC difference) was used to indicate the presence of wood smoke. Concentrations of OM, BC, C2H4O2+, and levoglucosan, as well as the UV-BC difference, were all highest during the evening hours (generally between 1800 and 0000 LST). Average OM concentrations were 3.3 μg/m3 during January but were 6.9 μg/m3 during the overnight hours (between 1700 and 0000 LST). Median levoglucosan concentrations were 0.14 μg/m3. The correlation of levoglucosan with C2H4O2+ was very high (r2=0.92). During the evening hours, correlation between BC and C2H4O2+ was good (r2=0.79); however, correlation was poor during other hours (r2<0.40), suggesting that other emissions such as mobile-source emissions were likely the dominant source of BC during those hours. C2H4O2+ showed modest correlation with UV-BC (e.g., r2=0.45). Using EPA's positive matrix factorization tool, EPA PMF, on the January HR-AMS data, we determined that biomass burning organic aerosol (BBOA) constituted 12% of the OM on average, but about 25% of the OM during evening hours. BBOA correlated well with levoglucosan (r2=0.82) and C2H4O2+ (r2=0.93). Levoglucosan measurements suggested that wood burning could constitute 38% of the OM during the overnight periods on average, although this number greatly depends on the assumed ratio of levoglucosan to OM in a source profile for residential biomass burning. The particle size distributions of mass for OM and m/z 60 (which includes other ions but is dominated by C2H4O2+) were quite broad, peaking between 100 nm and 450 nm for m/z 60 and between 200 nm and 450 nm for OM, suggesting relatively fresh aerosol. H/C ratios were highest (typically 1.57) and O/C ratios were lowest (typically 0.25) during evening hours, and the OM/OC ratio was, on average, 1.47, also indicating very fresh aerosol. Using levoglucosan and AMS markers, we can separate residential biomass burning influences from other sources of carbonaceous aerosol in the area.

Evaluation of Polygenic Risk Scores for Breast and Ovarian Cancer Risk Prediction in BRCA1 and BRCA2 Mutation Carriers

PubMed Central

Kuchenbaecker, Karoline B.; McGuffog, Lesley; Barrowdale, Daniel; Lee, Andrew; Soucy, Penny; Healey, Sue; Dennis, Joe; Lush, Michael; Robson, Mark; Spurdle, Amanda B.; Ramus, Susan J.; Mavaddat, Nasim; Terry, Mary Beth; Neuhausen, Susan L.; Hamann, Ute; Southey, Melissa; John, Esther M.; Chung, Wendy K.; Daly, Mary B.; Buys, Saundra S.; Goldgar, David E.; Dorfling, Cecilia M.; van Rensburg, Elizabeth J.; Ding, Yuan Chun; Ejlertsen, Bent; Gerdes, Anne-Marie; Hansen, Thomas V. O.; Slager, Susan; Hallberg, Emily; Benitez, Javier; Osorio, Ana; Cohen, Nancy; Lawler, William; Weitzel, Jeffrey N.; Peterlongo, Paolo; Pensotti, Valeria; Dolcetti, Riccardo; Barile, Monica; Bonanni, Bernardo; Azzollini, Jacopo; Manoukian, Siranoush; Peissel, Bernard; Radice, Paolo; Savarese, Antonella; Papi, Laura; Giannini, Giuseppe; Fostira, Florentia; Konstantopoulou, Irene; Adlard, Julian; Brewer, Carole; Cook, Jackie; Davidson, Rosemarie; Eccles, Diana; Eeles, Ros; Ellis, Steve; Frost, Debra; Hodgson, Shirley; Izatt, Louise; Lalloo, Fiona; Ong, Kai-ren; Godwin, Andrew K.; Arnold, Norbert; Dworniczak, Bernd; Engel, Christoph; Gehrig, Andrea; Hahnen, Eric; Hauke, Jan; Kast, Karin; Meindl, Alfons; Niederacher, Dieter; Schmutzler, Rita Katharina; Varon-Mateeva, Raymonda; Wang-Gohrke, Shan; Wappenschmidt, Barbara; Barjhoux, Laure; Collonge-Rame, Marie-Agnès; Elan, Camille; Golmard, Lisa; Barouk-Simonet, Emmanuelle; Lesueur, Fabienne; Mazoyer, Sylvie; Sokolowska, Joanna; Stoppa-Lyonnet, Dominique; Isaacs, Claudine; Claes, Kathleen B. M.; Poppe, Bruce; de la Hoya, Miguel; Garcia-Barberan, Vanesa; Aittomäki, Kristiina; Nevanlinna, Heli; Ausems, Margreet G. E. M.; de Lange, J. L.; Gómez Garcia, Encarna B.; Hogervorst, Frans B. L.; Kets, Carolien M.; Meijers-Heijboer, Hanne E. J.; Oosterwijk, Jan C.; Rookus, Matti A.; van Asperen, Christi J.; van den Ouweland, Ans M. W.; van Doorn, Helena C.; van Os, Theo A. M.; Kwong, Ava; Olah, Edith; Diez, Orland; Brunet, Joan; Lazaro, Conxi; Teulé, Alex; Gronwald, Jacek; Jakubowska, Anna; Kaczmarek, Katarzyna; Lubinski, Jan; Sukiennicki, Grzegorz; Barkardottir, Rosa B.; Chiquette, Jocelyne; Agata, Simona; Montagna, Marco; Teixeira, Manuel R.; Park, Sue Kyung; Olswold, Curtis; Tischkowitz, Marc; Foretova, Lenka; Gaddam, Pragna; Vijai, Joseph; Pfeiler, Georg; Rappaport-Fuerhauser, Christine; Singer, Christian F.; Tea, Muy-Kheng M.; Greene, Mark H.; Loud, Jennifer T.; Rennert, Gad; Imyanitov, Evgeny N.; Hulick, Peter J.; Hays, John L.; Piedmonte, Marion; Rodriguez, Gustavo C.; Martyn, Julie; Glendon, Gord; Mulligan, Anna Marie; Andrulis, Irene L.; Toland, Amanda Ewart; Jensen, Uffe Birk; Kruse, Torben A.; Pedersen, Inge Sokilde; Thomassen, Mads; Caligo, Maria A.; Teo, Soo-Hwang; Berger, Raanan; Friedman, Eitan; Laitman, Yael; Arver, Brita; Borg, Ake; Ehrencrona, Hans; Rantala, Johanna; Olopade, Olufunmilayo I.; Ganz, Patricia A.; Nussbaum, Robert L.; Bradbury, Angela R.; Domchek, Susan M.; Nathanson, Katherine L.; Arun, Banu K.; James, Paul; Karlan, Beth Y.; Lester, Jenny; Simard, Jacques; Pharoah, Paul D. P.; Offit, Kenneth; Couch, Fergus J.; Chenevix-Trench, Georgia; Easton, Douglas F.

2017-01-01

Background: Genome-wide association studies (GWAS) have identified 94 common single-nucleotide polymorphisms (SNPs) associated with breast cancer (BC) risk and 18 associated with ovarian cancer (OC) risk. Several of these are also associated with risk of BC or OC for women who carry a pathogenic mutation in the high-risk BC and OC genes BRCA1 or BRCA2. The combined effects of these variants on BC or OC risk for BRCA1 and BRCA2 mutation carriers have not yet been assessed while their clinical management could benefit from improved personalized risk estimates. Methods: We constructed polygenic risk scores (PRS) using BC and OC susceptibility SNPs identified through population-based GWAS: for BC (overall, estrogen receptor [ER]–positive, and ER-negative) and for OC. Using data from 15 252 female BRCA1 and 8211 BRCA2 carriers, the association of each PRS with BC or OC risk was evaluated using a weighted cohort approach, with time to diagnosis as the outcome and estimation of the hazard ratios (HRs) per standard deviation increase in the PRS. Results: The PRS for ER-negative BC displayed the strongest association with BC risk in BRCA1 carriers (HR = 1.27, 95% confidence interval [CI] = 1.23 to 1.31, P = 8.2×10−53). In BRCA2 carriers, the strongest association with BC risk was seen for the overall BC PRS (HR = 1.22, 95% CI = 1.17 to 1.28, P = 7.2×10−20). The OC PRS was strongly associated with OC risk for both BRCA1 and BRCA2 carriers. These translate to differences in absolute risks (more than 10% in each case) between the top and bottom deciles of the PRS distribution; for example, the OC risk was 6% by age 80 years for BRCA2 carriers at the 10th percentile of the OC PRS compared with 19% risk for those at the 90th percentile of PRS. Conclusions: BC and OC PRS are predictive of cancer risk in BRCA1 and BRCA2 carriers. Incorporation of the PRS into risk prediction models has promise to better inform decisions on cancer risk management. PMID:28376175

Evaluation of Polygenic Risk Scores for Breast and Ovarian Cancer Risk Prediction in BRCA1 and BRCA2 Mutation Carriers.

PubMed

Kuchenbaecker, Karoline B; McGuffog, Lesley; Barrowdale, Daniel; Lee, Andrew; Soucy, Penny; Dennis, Joe; Domchek, Susan M; Robson, Mark; Spurdle, Amanda B; Ramus, Susan J; Mavaddat, Nasim; Terry, Mary Beth; Neuhausen, Susan L; Schmutzler, Rita Katharina; Simard, Jacques; Pharoah, Paul D P; Offit, Kenneth; Couch, Fergus J; Chenevix-Trench, Georgia; Easton, Douglas F; Antoniou, Antonis C

2017-07-01

Genome-wide association studies (GWAS) have identified 94 common single-nucleotide polymorphisms (SNPs) associated with breast cancer (BC) risk and 18 associated with ovarian cancer (OC) risk. Several of these are also associated with risk of BC or OC for women who carry a pathogenic mutation in the high-risk BC and OC genes BRCA1 or BRCA2. The combined effects of these variants on BC or OC risk for BRCA1 and BRCA2 mutation carriers have not yet been assessed while their clinical management could benefit from improved personalized risk estimates. We constructed polygenic risk scores (PRS) using BC and OC susceptibility SNPs identified through population-based GWAS: for BC (overall, estrogen receptor [ER]-positive, and ER-negative) and for OC. Using data from 15 252 female BRCA1 and 8211 BRCA2 carriers, the association of each PRS with BC or OC risk was evaluated using a weighted cohort approach, with time to diagnosis as the outcome and estimation of the hazard ratios (HRs) per standard deviation increase in the PRS. The PRS for ER-negative BC displayed the strongest association with BC risk in BRCA1 carriers (HR = 1.27, 95% confidence interval [CI] = 1.23 to 1.31, P =  8.2×10 -53 ). In BRCA2 carriers, the strongest association with BC risk was seen for the overall BC PRS (HR = 1.22, 95% CI = 1.17 to 1.28, P =  7.2×10 -20 ). The OC PRS was strongly associated with OC risk for both BRCA1 and BRCA2 carriers. These translate to differences in absolute risks (more than 10% in each case) between the top and bottom deciles of the PRS distribution; for example, the OC risk was 6% by age 80 years for BRCA2 carriers at the 10th percentile of the OC PRS compared with 19% risk for those at the 90th percentile of PRS. BC and OC PRS are predictive of cancer risk in BRCA1 and BRCA2 carriers. Incorporation of the PRS into risk prediction models has promise to better inform decisions on cancer risk management. © The Author 2017. Published by Oxford University Press.

Blood based cell biopsy for early detection of cancer

NASA Astrophysics Data System (ADS)

Tang, Cha-Mei; Adams, Daniel; Adams, Diane; Alpaugh, R. Katherine; Cristofanilli, Massimo; Martin, Stuart; Chumsri, Saranya; Marks, Jeffrey

Early detection (ED) of cancer holds the promise for less aggressive treatments and better outcome. However, there are few accepted methods for ED. We report on a previously unknown blood cell found specifically in the peripheral blood of many solid tumors. They are defined as Cancer Associated Macrophage-Like cells (CAMLs) and are characterized by large size (25-300 μm) and expression of cancer markers. CAMLs were isolated on precision filters during blood filtration. We conducted prospective studies in breast cancer (BC) to ascertain CAML prevalence, specificity and sensitivity in relation to disease status at clinical presentation. We report on two related but separate studies: 1) the isolation of CAMLs from patients with known invasive BC, compared to healthy volunteers and, 2) a double blind study conducted on women undergoing core needle biopsy to evaluate suspicious breast masses. The studies show that CAMLs are found in all stages of BC and suggest that detection of CAMLs can differentiate patients with BC from those with benign breast conditions and healthy individuals. This non-invasive blood test can be potentially used for ED of BC and other malignancies after validation studies with the advantage of a minimally invasive procedure and longitudinal monitoring. This work was supported by Grants from Maryland TEDCO MTTCF, R01-CA154624 from NIH, KG100240 from Susan G. Komen Foundation, Era of Hope Scholar award from DoD (BC100675), and U01-CA084955 from NCI EDRN.

Nanoparticle string formation on self-assembled copolymer films

NASA Astrophysics Data System (ADS)

Jenczyk, J.; Woźniak-Budych, M.; Jarek, M.; Grzeszkowiak, M.; Nowaczyk, G.; Jurga, S.

2017-06-01

Nanoparticles (NP) string formations on self-assembled copolymeric substrates has been observed. These "thread of beads" like structures develop via simple colloidal droplet evaporation during meniscus rim withdrawal on polystyrene-block-poly(ethylene oxide) (PS-PEO) copolymer surfaces. It is shown that the process is triggered by the presence of the substrate impurities, which lead to NP aggregate formations serving as string initiation sites. The growth mechanism of these linear structures seems to be capillarity-driven. Moreover, there is an exceptional alignment coupling between NP strips and the block copolymer (BC) domains observed. BC directed NP assembly stems from a gold nanocrystal surface functionalization, which introduces selective affinity for one particular type of BC domain. The presented results reveal a potential fabrication method of NP wires characterized by remarkably low width and thickness comparable with the size of the individual constituent NP.

76 FR 20049 - Notice of Revised Determination on Reconsideration

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-11

... Distribution Center, 100 T.G. Vaughan, Jr. Road, Galax, Virginia On December 3, 2010, the Department of Labor... Company, Inc., T.G. Vaughan Distribution Center, 100 T.G. Vaughan, Jr. Road, Galax, Virginia (TA-W-74,551B... to B.C. Vaughan Factory/Chestnut Creek Veneer Building (TA-W-74,551A) and T.G. Vaughan Distribution...

An AeroCom Assessment of Black Carbon in Arctic Snow and Sea Ice

NASA Technical Reports Server (NTRS)

Jiao, C.; Flanner, M. G.; Balkanski, Y.; Bauer, S. E.; Bellouin, N.; Bernsten, T. K.; Bian, H.; Carslaw, K. S.; Chin, M.; DeLuca, N.;

Black carbon in deep-sea sediments from the northeastern equatorial Pacific Ocean

NASA Astrophysics Data System (ADS)

Kim, D.; Lee, Y.; Hyeong, K.; Yoo, C.

2011-12-01

Deep-sea sediment core is a good archive for understanding the land-ocean interactions via atmosphere, due to it is little influenced by fluvial and continental shelf processes. This study dealt with black carbon(BC) in a 328 cm-long piston core collected from the northeastern equatorial Pacific Ocean (16°12'N, 125°59'W), covering the last 15 Ma (Hyeong at al., 2004). BC is a common name of carbon continuum formed by incomplete combustion of fossil fuels and plant materials. Though it may react with ozone and produce water-soluble organic carbon, BC has commonly refractory nature. Thus BC in preindustrial sediment can be a tracer of forest-fire events. BC is purely terrestrial in origin, and is transported to marine environments by atmospheric and fluvial processes. Therefore, distribution of BC in deep-sea sediments could be used to understand atmospheric circulation. Chemical oxidation was used to determine BC in this study following Lim and Cachier (1996). Concentration of BC varies from 0.010% to 0.233% of total sediments. Mass accumulation rate (MAR) of BC ranged between 0.077 mg/cm^2/1000 yrs and 47.49 mg/cm^21000 yrs. It is noted that MAR in sediments younger than 8 Ma (av. 9.0 mg/cm^2/1000 yrs) is higher than that in sediments older than 8 Ma (av. 3.2 mg/cm^2/1000 yrs). Stable carbon isotope value of BC increases with time from the low δ13C value near 13 Ma until it reaches the highest value near 4 Ma. Change of MAR seems to be related to the meridional migration of Intertropical Convergence Zone (ITCZ) at around 8 Ma in the study area (cf., Hyeong at al., 2004). Accordingly, higher BC content in sediment younger than 8 Ma seems to be accounted for by its derivation from the Northern Hemisphere compared to that from the Southern Hemisphere in older sediment. Increase of carbon isotope value with time seems to be related to expansion of C4 grassland. C4 grassland expansion might have been caused by change of atmosphreic cycle, which moved dry subtropical ridge. The migration of high pressure zone caused development of new arid region, resulting in C3 forest-fire, and expansion of C4 vegetation (Bond, W.J. et al. 2005). keywords : black carbon; northeastern equatorial Pacific Ocean; Intertropical Convergence Zone Hyeong, K., S.-H. Park, C.M. Yoo, and K-H. KIm, 2005, Mineralogical and geochemical compositions of the eolian dust from the northeast equatorial Pacific and their implications on paleolocation of Intertropical Convergence Zone, Paleoceanography, 20, PA1010, doi:10.1029/2004PA001053 Bond, W.J., Woodward, F.I. and Midgley, G.F., 2005, The global distribution of ecosystems in a world without fire. New Phytologist, v. 165, p. 525-538. Lim, B. and Cachier, H., 1996, Determination of black carbon by chemical oxidation and thermal treatment in recent marine and lake sediments and Cretaceous-Tertiary clays. Chemical Geology, 131, 143-154.

Factors affecting pollutant concentrations in the near-road environment

NASA Astrophysics Data System (ADS)

Baldwin, Nichole; Gilani, Owais; Raja, Suresh; Batterman, Stuart; Ganguly, Rajiv; Hopke, Philip; Berrocal, Veronica; Robins, Thomas; Hoogterp, Sarah

2015-08-01

An improved understanding of traffic-related air pollutants is needed to estimate exposures and adverse health impacts in traffic corridors and near-road environments. In this study, concentrations of black carbon (BC), nitrogen oxides (NO, NO2, NOx), sulfur dioxide (SO2), and particulate matter (PM2.5, PM10, ultrafine particles, and accumulation mode particles, AMP) were measured using a mobile air pollutant laboratory along nine transects across major roads in Detroit, MI in winter 2012. Repeated measurements were taken during rush-hour periods at sites in residential neighborhoods located 50-500 m from both sides of the road. Concentration gradients attributable to on-road emissions were estimated by accounting for traffic volume and mix, wind speed, wind direction, and background concentrations. BC, NO, NOx, and UFP had the strongest gradients, and elevated concentrations of NOx, NO2, PM2.5 and PM10, as well as decreased particle size, were found at the 50 m sites compared to background levels. Exponential models incorporating effects of road size, wind speed, and up- and downwind distance explained from 31 to 53% of the variability in concentration gradients for BC, NO, NOx, UFP and particle size. The expected concentration increments 50 m from the study roads were 17.0 ppb for NO, 17.7 ppb for NOx, 2245 particles/cm3 for UFP, and 0.24 μg/m3 for BC, and the expected distance to decrease increments by half was 89-129 m in the downwind direction, and 14-20 m in the upwind direction. While accounting for portion of the temporal and spatial variability across transects and measurement periods, these results highlight the influence of road-to-road differences and other locally-varying factors important in urban and industrial settings. The study demonstrates a methodology to quantify near-road concentrations and influences on these concentrations while accounting for temporal and spatial variability, and it provides information useful for estimating exposures of traffic-related air pollutants in urban environments.

Prognostic Effects of Adjuvant Chemotherapy-Induced Amenorrhea and Subsequent Resumption of Menstruation for Premenopausal Breast Cancer Patients

PubMed Central

Jeon, Se Jeong; Lee, Jae Il; Jeon, Myung Jae; Lee, Maria

2016-01-01

Abstract Chemotherapy-induced amenorrhea (CIA) is a side effect that occurs in patients with breast cancer (BC) as a result of chemotherapy. These patients require special treatments to avoid infertility and menopause. However, the factors controlling CIA, resumption of menstruation (RM), and persistence of menstruation after chemotherapy are unknown. The long-term prognosis for premenopausal patients with BC and the prognostic factors associated with CIA and RM are subject to debate. We performed a retrospective study by reviewing the medical records of 249 patients with BC (stage I to stage III) who were treated with cytotoxic chemotherapy. The median patient age was 43 (range, 26–55 years) and the median duration of follow-up was 64 months (range, 28–100 months). The medical records indicated that 219 patients (88.0%) scored as positive for the hormone receptor (HR); the majority of these patients completed chemotherapy and then received additional therapy of tamoxifen. Our analyses revealed that 88.0% (n = 219) of patients experienced CIA, and the percentage of RM during follow-up was 48.6% (n = 121). A total of 30 patients (12.0%) did not experience CIA. Disease-free survival (DFS) was affected by several factors, including tumour size ≥2 cm, node positivity, HR negative status, and body mass index ≥23 kg/m2. Multivariate analysis indicated that tumour size ≥2 cm remained as a significant factor for DFS (hazard ratio = 3.3, P = 0.034). In summary, this study finds that the majority of premenopausal patients with BC (stage I to stage III) who receive chemotherapy experience CIA and subsequent RM. Although tumour size ≥2 cm is negatively associated with DFS, RM after CIA is not associated with poor prognosis. PMID:27057900

Persistence in Breast Cancer Disparities Between African Americans and Whites in Wisconsin

PubMed Central

Lepeak, Lisa; Tevaarwerk, Amye; Jones, Nathan; Williamson, Amy; Cetnar, Jeremy; LoConte, Noelle

2011-01-01

Background Breast cancer (BC) mortality is higher in African American women compared to white women despite having a lower incidence. The reasons for this remain unclear, despite decades of research. Reducing BC health disparities is a priority but has had limited success. Objective To assess progress in eliminating breast cancer-related health disparities in Wisconsin by comparing trends in breast cancer outcomes in African American and white women from 1995 to 2006 and comparing results nationally. Methods Age-adjusted breast cancer (BC) incidence and stage data from the Wisconsin Cancer Reporting System and age-adjusted mortality data from National Center of Health Statistics were used to evaluate trends in incidence and mortality from 1995 to 2006 for African Americans and whites. The relative disparity was evaluated by rate ratios. Trends in distribution of in situ versus malignant disease were examined. National trend data were obtained from the Nationa Cancer Institute (NCI) Surveillance, Epidemiology and End Results (SEER) database. Results Age-adjusted incidence decreased 10% in Wisconsin compared to 7% nationally. Incidence of BC was lower in African American compared to white women. BC mortality in African American women declined in Wisconsin, but remained higher than white females. Age-adjusted mortality in Wisconsin declined approximately 23%, matching national trends. Non age-adjusted stage data trended toward a decrease in malignant, but increased in situ disease. Conclusions Despite an overall reduction in BC mortality from 1995 to 2006, a persistent disparity in mortality remains for African American women, demonstrating no significant progress in reducing BC health disparities. PMID:21473509

Atmospheric black carbon in the Russian Arctic: anthropogenic inputs in comparison with average or extremal wood fires' ones

NASA Astrophysics Data System (ADS)

Vinogradova, Anna A.; Smirnov, Nikolay S.; Korotkov, Vladimir N.

2016-04-01

Model estimates of atmospheric black carbon concentrations were made for different points of the Russian Arctic. Anthropogenic BC emissions and wood fires' ones were calculated from Russian official statistics for the 2000s. We used the data of Ministry of Natural Resources and Environment of RF on anthropogenic air emissions of pollution in Russian cities and regions [1], as well as the data of Federal Forestry Agency of RF (Rosleshoz) [2] on wood fires. We considered the area within (50-72)N and (20-180)E, which covers about 94% of the Russian territory, where both anthropogenic and fire BC emissions have been arranged through grid cells (1×1) deg. Anthropogenic BC emissions are estimated as annual values based on the data for 54 regions and more than 100 cities. Total emission is estimated as (220 ± 30) Gg BC in 2010 [3], including emissions from open flares associated with gas/oil extractive industry which are about (25 ± 8) Gg/yr. We analyzed the data on wood fires (detailing crown, ground and underground fires in forests and fires on non-forest lands) with their spatial and seasonal variations during 15 years (2000-2014). Different combustion factors [4] and BC emission coefficients [5] were used in calculations for different types of burning. Russian total average annual BC emission from fires, occurring mainly in summertime, was estimated as 30 Gg with large variations (4-100 Gg/yr) from year to year. Asian territory emits about 90% of this value. We estimated anthropogenic (BC_A) and fires' (BC_F) contributions to BC air concentrations at different Russian Arctic points using the approach [6] - decadal back-trajectory analysis combined with spatial distribution of sensitivity pollution emission function (SPEF). Extraordinary atmospheric circulation causing, to a great extent, abnormally intensive fires in the middle latitudes often leads to a decrease in SPEF values for these territories. As a result, fires are not so dangerous for the whole Arctic, as it is believed. But there are distinctions at various points: Kola Peninsula - annually BC concentrations in air are not sizable and BCA prevails, but BCF prevails in summer. SE of Arkhangelsk region - annually BCA prevails, but in summer BCA is equal to BC_F, and in summer 2010 BCF was 2 times higher. Nenetsky Nature Reserve - BCF always prevails. Gydansky Nature Reserve - BCA prevails through a year, previously from oil/gas flares. Ust'-Lensky Nature Reserve - annually BC concentrations in air are not sizable, but in summer 2012 BCF prevails and is near the same as at Nenetsky Nature Reserve. The work was supported by RFBR, grants: 14-05-00059, 14-05-93089. _____________________ 1. Yearbook 2010 on Atmospheric Emissions of Pollution in Towns and Regions of Russian Federation. St.Petersburg, SRI Atmosphere, 2011. - 560 pp. [in Russian]. 2. http://www.rosleshoz.gov.ru/; http://www.aviales.ru/ 3. Vinogradova A.A. Anthropogenic Black Carbon Emissions to the Atmosphere: Surface Distribution through Russian Territory // DOI: 10.1134/S1024856015020141 4. http://www.ipcc-nggip.iges.or.jp/public/2006gl/vol4.html 5. Akagi S.K. et al. Emission factors for open and domestic biomass burning for use in atmospheric models // DOI: 10.5194/acp-11-4039-2011 6. Vinogradova A.A. Distant evaluation of atmospheric pollution influence on the remote territories // DOI:10.1134/S0001433815070099

Physical and chemical characterization of urban winter-time aerosols by mobile measurements in Helsinki, Finland

NASA Astrophysics Data System (ADS)

Pirjola, Liisa; Niemi, Jarkko V.; Saarikoski, Sanna; Aurela, Minna; Enroth, Joonas; Carbone, Samara; Saarnio, Karri; Kuuluvainen, Heino; Kousa, Anu; Rönkkö, Topi; Hillamo, Risto

2017-06-01

A two-week measurement campaign by a mobile laboratory van was performed in urban environments in the Helsinki metropolitan area, Finland, in winter 2012, to obtain a comprehensive view on aerosol properties and sources. The abundances and physico-chemical properties of particles varied strongly in time and space, depending on the main sources of aerosols. Four major types of winter aerosol were recognized: 1) clean background aerosol with low particle number (Ntot) and lung deposited surface area (LDSA) concentrations due to marine air flows from the Atlantic Ocean; 2) long-range transported (LRT) pollution aerosol due to air flows from eastern Europe where the particles were characterized by the high contribution of oxygenated organic aerosol (OOA) and inorganic species, particularly sulphate, but low BC contribution, and their size distribution possessed an additional accumulation mode; 3) fresh smoke plumes from residential wood combustion in suburban small houses, these particles were characterized by high biomass burning organic aerosol (BBOA) and black carbon (BC) concentrations; and 4) fresh emissions from traffic while driving on busy streets in the city centre and on the highways during morning rush hours. This aerosol was characterized by high concentration of Ntot, LDSA, small particles in the nucleation mode, as well as high hydrocarbon-like organic aerosol (HOA) and BC concentrations. In general, secondary components (OOA, NO3, NH4, and SO4) dominated the PM1 chemical composition during the LRT episode accounting for 70-80% of the PM1 mass, whereas fresh primary emissions (BC, HOA and BBOA) dominated the local traffic and wood burning emissions. The major individual particle types observed with electron microscopy analysis (TEM/EDX) were mainly related to residential wood combustion (K/S/C-rich, soot, other C-rich particles), traffic (soot, Si/Al-rich, Fe-rich), heavy fuel oil combustion in heat plants or ships (S with V-Ni-Fe), LRT pollutants (S/C-rich secondary particles) and sea salt (Na/Cl-rich). Tar balls from wood combustion were also observed, especially (∼5%) during the LRT pollution episode.

Collection efficiency of the soot-particle aerosol mass spectrometer (SP-AMS) for internally mixed particulate black carbon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Willis, M. D.; Lee, A. K. Y.; Onasch, T. B.

The soot-particle aerosol mass spectrometer (SP-AMS) uses an intra-cavity infrared laser to vaporize refractory black carbon (rBC) containing particles, making the particle beam–laser beam overlap critical in determining the collection efficiency (CE) for rBC and associated non-refractory particulate matter (NR-PM). This work evaluates the ability of the SP-AMS to quantify rBC and NR-PM mass in internally mixed particles with different thicknesses of organic coating. Using apparent relative ionization efficiencies for uncoated and thickly coated rBC particles, we report measurements of SP-AMS sensitivity to NR-PM and rBC, for Regal Black, the recommended particulate calibration material. Beam width probe (BWP) measurements aremore » used to illustrate an increase in sensitivity for highly coated particles due to narrowing of the particle beam, which enhances the CE of the SP-AMS by increasing the laser beam–particle beam overlap. Assuming complete overlap for thick coatings, we estimate CE for bare Regal Black particles of 0.6 ± 0.1, which suggests that previously measured SP-AMS sensitivities to Regal Black were underestimated by up to a factor of 2. The efficacy of the BWP measurements is highlighted by studies at a busy road in downtown Toronto and at a non-roadside location, which show particle beam widths similar to, but greater than that of bare Regal Black and coated Regal Black, respectively. Further BWP measurements at field locations will help to constrain the range of CE for fresh and aged rBC-containing particles. The ability of the SP-AMS to quantitatively assess the composition of internally mixed particles is validated through measurements of laboratory-generated organic coated particles, which demonstrate that the SP-AMS can quantify rBC and NR-PM over a wide range of particle compositions and rBC core sizes.« less

Collection efficiency of the soot-particle aerosol mass spectrometer (SP-AMS) for internally mixed particulate black carbon

DOE PAGES

Willis, M. D.; Lee, A. K. Y.; Onasch, T. B.; ...

2014-12-18

The soot-particle aerosol mass spectrometer (SP-AMS) uses an intra-cavity infrared laser to vaporize refractory black carbon (rBC) containing particles, making the particle beam–laser beam overlap critical in determining the collection efficiency (CE) for rBC and associated non-refractory particulate matter (NR-PM). This work evaluates the ability of the SP-AMS to quantify rBC and NR-PM mass in internally mixed particles with different thicknesses of organic coating. Using apparent relative ionization efficiencies for uncoated and thickly coated rBC particles, we report measurements of SP-AMS sensitivity to NR-PM and rBC, for Regal Black, the recommended particulate calibration material. Beam width probe (BWP) measurements aremore » used to illustrate an increase in sensitivity for highly coated particles due to narrowing of the particle beam, which enhances the CE of the SP-AMS by increasing the laser beam–particle beam overlap. Assuming complete overlap for thick coatings, we estimate CE for bare Regal Black particles of 0.6 ± 0.1, which suggests that previously measured SP-AMS sensitivities to Regal Black were underestimated by up to a factor of 2. The efficacy of the BWP measurements is highlighted by studies at a busy road in downtown Toronto and at a non-roadside location, which show particle beam widths similar to, but greater than that of bare Regal Black and coated Regal Black, respectively. Further BWP measurements at field locations will help to constrain the range of CE for fresh and aged rBC-containing particles. The ability of the SP-AMS to quantitatively assess the composition of internally mixed particles is validated through measurements of laboratory-generated organic coated particles, which demonstrate that the SP-AMS can quantify rBC and NR-PM over a wide range of particle compositions and rBC core sizes.« less

Comparison of MADE3-simulated and observed aerosol distributions with a focus on aerosol vertical profiles

NASA Astrophysics Data System (ADS)

Kaiser, Christopher; Hendricks, Johannes; Righi, Mattia; Jöckel, Patrick

2016-04-01

The reliability of aerosol radiative forcing estimates from climate models depends on the accuracy of simulated global aerosol distribution and composition, as well as on the models' representation of the aerosol-cloud and aerosol-radiation interactions. To help improve on previous modeling studies, we recently developed the new aerosol microphysics submodel MADE3 that explicitly tracks particle mixing state in the Aitken, accumulation, and coarse mode size ranges. We implemented MADE3 into the global atmospheric chemistry general circulation model EMAC and evaluated it by comparison of simulated aerosol properties to observations. Compared properties include continental near-surface aerosol component concentrations and size distributions, continental and marine aerosol vertical profiles, and nearly global aerosol optical depth. Recent studies have shown the specific importance of aerosol vertical profiles for determination of the aerosol radiative forcing. Therefore, our focus here is on the evaluation of simulated vertical profiles. The observational data is taken from campaigns between 1990 and 2011 over the Pacific Ocean, over North and South America, and over Europe. The datasets include black carbon and total aerosol mass mixing ratios, as well as aerosol particle number concentrations. Compared to other models, EMAC with MADE3 yields good agreement with the observations - despite a general high bias of the simulated mass mixing ratio profiles. However, BC concentrations are generally overestimated by many models in the upper troposphere. With MADE3 in EMAC, we find better agreement of the simulated BC profiles with HIPPO data than the multi-model average of the models that took part in the AeroCom project. There is an interesting difference between the profiles from individual campaigns and more "climatological" datasets. For instance, compared to spatially and temporally localized campaigns, the model simulates a more continuous decline in both total aerosol and black carbon mass mixing ratio with altitude than found in the observations. In contrast, measured profiles from the HIPPO project are qualitatively captured well. Similar conclusions hold for the comparison of simulated and measured aerosol particle number concentrations. On the one hand, these results exemplify the difficulty in evaluating the representativeness of the simulated global climatological state of the aerosol by means of comparison with individually measured vertical profiles. On the other hand, it highlights the value of aircraft campaigns with large spatial and temporal coverage for model evaluation.

Cognizance and utilization about breast cancer screening among the health professional female students and staffs of University Kuala Lumpur, Royal College of Medicine Perak, Malaysia

PubMed Central

Haque, A. T. M. Emdadul; Mohd Hisham, Muhammad Afif Bin; Ahmad Adzman, Noor Azwa Laili Binti; Azudin, Nur Atiqah Binti; Shafri, Nursakinah Binti; Haque, Mainul

2016-01-01

Background: Breast cancer (BC) is a major life-threatening problem and a global concern including Malaysia. BC is an equal threat for both developing and developed countries. The aim of this study was to determine the relationship between sociodemographic factors with knowledge, attitude, and perception on BC screening among the females of University Kuala Lumpur, Royal College of Medicine Perak (UniKL RCMP). Materials and Methods: This cross-sectional study was conducted from 2015 to 2016. The populations included were the students and staff of UniKL RCMP. The simple sampling method was used and a set of questionnaire was prepared and distributed to the participants who were willing to participate. The data were analyzed by using the SPSS version 17. Results: Of the 220 only 203 questionnaires were returned. Nearly 87.7% of participants indicated genetic factors as the cause of BC, followed by exposure to carcinogenic and X-ray. Excessive smoking (54.2%) and sedentary lifestyle (52.2%) were the risk factors of the BC. 100% of participants thought that breast self-examination (BSE) is important to detect a breast lump and most of them (76.8%) knew what a mammogram is but only 2.0% went for a mammogram. Chemotherapy (71.9%) and surgery (71.9%) were treatments options according to study participants. Nearly 91.1% agreed that regular mammogram could help to detect BC at an early stage. Nearly 88.2% thought BC is not easily curable. Finally, for the attitude on BC screening, most of them knew how to perform BSE (69.0%) with the frequency of 36.0% doing it once a year. Conclusions: The majority of the participants found the good knowledge on BC and on how to perform BSE. Although most of them knew what a mammogram is, only a few have gone for it since perhaps it is recommended for those who are above 50-year-old. Therefore, researchers believe and trust that there is an urgent need of state-funded multicenter study to prevent and early diagnosis of BC in Malaysia. PMID:28144097

Cognizance and utilization about breast cancer screening among the health professional female students and staffs of University Kuala Lumpur, Royal College of Medicine Perak, Malaysia.

PubMed

Haque, A T M Emdadul; Mohd Hisham, Muhammad Afif Bin; Ahmad Adzman, Noor Azwa Laili Binti; Azudin, Nur Atiqah Binti; Shafri, Nursakinah Binti; Haque, Mainul

2016-01-01

Breast cancer (BC) is a major life-threatening problem and a global concern including Malaysia. BC is an equal threat for both developing and developed countries. The aim of this study was to determine the relationship between sociodemographic factors with knowledge, attitude, and perception on BC screening among the females of University Kuala Lumpur, Royal College of Medicine Perak (UniKL RCMP). This cross-sectional study was conducted from 2015 to 2016. The populations included were the students and staff of UniKL RCMP. The simple sampling method was used and a set of questionnaire was prepared and distributed to the participants who were willing to participate. The data were analyzed by using the SPSS version 17. Of the 220 only 203 questionnaires were returned. Nearly 87.7% of participants indicated genetic factors as the cause of BC, followed by exposure to carcinogenic and X-ray. Excessive smoking (54.2%) and sedentary lifestyle (52.2%) were the risk factors of the BC. 100% of participants thought that breast self-examination (BSE) is important to detect a breast lump and most of them (76.8%) knew what a mammogram is but only 2.0% went for a mammogram. Chemotherapy (71.9%) and surgery (71.9%) were treatments options according to study participants. Nearly 91.1% agreed that regular mammogram could help to detect BC at an early stage. Nearly 88.2% thought BC is not easily curable. Finally, for the attitude on BC screening, most of them knew how to perform BSE (69.0%) with the frequency of 36.0% doing it once a year. The majority of the participants found the good knowledge on BC and on how to perform BSE. Although most of them knew what a mammogram is, only a few have gone for it since perhaps it is recommended for those who are above 50-year-old. Therefore, researchers believe and trust that there is an urgent need of state-funded multicenter study to prevent and early diagnosis of BC in Malaysia.

Estimation of columnar concentrations of absorbing and scattering fine mode aerosol components using AERONET data

NASA Astrophysics Data System (ADS)

Choi, Yongjoo; Ghim, Young Sung

2016-11-01

Columnar concentrations of absorbing and scattering components of fine mode aerosols were estimated using Aerosol Robotic Network (AERONET) data for a site downwind of Seoul. The study period was between March 2012 and April 2013 including the period of the Distributed Regional Aerosol Gridded Observation Networks (DRAGON)-Asia campaign in March to May 2012. The Maxwell Garnett mixing rule was assumed for insoluble components embedded in a host solution, while the volume average mixing rule was assumed for the aqueous solution of soluble components. During the DRAGON-Asia campaign the surface concentrations of major components of fine particles were measured. The columnar mass fractions of black carbon (BC), organic carbon (OC), mineral dust (MD), and ammonium sulfate (AS) were 1.5, 5.9, 6.6, and 52%, respectively, which were comparable to the mass fractions measured at the surface for BC, OC, and secondary inorganic aerosols at 2.3, 18, and 55%. The vertical distributions of BC and AS were investigated by employing the concept of a column height. While the column height for BC was similar to the planetary boundary layer (PBL) height, that for AS was 4.4 times higher than the PBL height and increased with air temperature from March to May. The monthly variations of the columnar mass concentrations during the study period were generally well explained in term of meteorology and emission characteristics. However, certain variations of MD were different from those typically observed primarily because only fine mode aerosols were considered.

Streambed Mobility and Dispersal of Aquatic Insect Larvae: Results from a Laboratory Study.

NASA Astrophysics Data System (ADS)

Kenworthy, S. T.

2002-12-01

Three series of flume experiments were conducted to quantify relationships between entrainment of surface layer gravels and displacement of benthic insect larvae. One series (B) utilized a sediment mixture with a median size 6.9 mm, maximum size 45 mm, and 10% < 2mm. Two other series examined the effects of locally coarsening the bed surface (Bc) and increasing the < 2mm fraction to 20% (S). Aquatic insect larvae were collected in the field and placed in an upstream segment of the flume bed. Flow rate, flume slope, and sediment transport rate were varied systematically among experiments. Displaced larvae were collected in a net at the end of the flume. The distribution of larvae remaining in the bed was obtained by sorting larvae from the sediment in 25 channel segments. Flow rate and mean boundary shear stress varied among runs by factors of 1.2 and 2.4 respectively. Proportional entrainment of >11mm surface grains ranged from <0.05 to >0.90. Displacement of insect larvae increased in a regular and consistent manner with increasing flow strength and surface sediment entrainment. Significant displacement occurred for some types of larvae (Ephemerellid mayflies) over a relatively low range of shear stress and bed surface entrainment. Other larvae (Atherix sp.) were displaced only at the highest levels of bed surface entrainment. Displacement was lower from coarsened bed surfaces in series Bc, and higher from sandier sediments in series S experiments. The differential effects of bed surface entrainment upon various types of larvae are consistent with anatomical and behavioral differences that influence exposure to near-bed flow and bedload transport. These results suggest that spatial patterns of sediment mobilization are important for understanding patterns of dispersal and disturbance of streambed communities.

Black carbon from ships: a review of the effects of ship speed, fuel quality and exhaust gas scrubbing

NASA Astrophysics Data System (ADS)

Lack, D. A.; Corbett, J. J.

2012-01-01

The International Maritime Organization (IMO) has moved to address the health and climate impact of the emissions from the combustion of low-quality residual fuels within the commercial shipping industry. Fuel sulfur content (FS) limits and an efficiency design index for future ships are examples of such IMO actions. The impacts of black carbon (BC) emissions from shipping are now under review by the IMO, with a particular focus on the potential impacts of future Arctic shipping. Recognizing that associating impacts with BC emissions requires both ambient and onboard observations, we provide recommendations for the measurement of BC. We also evaluate current insights regarding the effect of ship speed (engine load), fuel quality and exhaust gas scrubbing on BC emissions from ships. Observations demonstrate that BC emission factors (EFBC) increases 3 to 6 times at very low engine loads (<25% compared to EFBC at 85-100% load); absolute BC emissions (per nautical mile of travel) also increase up to 100% depending on engine load, even with reduced load fuel savings. If fleets were required to operate at lower maximum engine loads, presumably associated with reduced speeds, then engines could be re-tuned, which would reduce BC emissions. Ships operating in the Arctic are likely running at highly variable engine loads (25-100%) depending on ice conditions and ice breaking requirements. The ships operating at low load may be emitting up to 50% more BC than they would at their rated load. Such variable load conditions make it difficult to assess the likely emissions rate of BC. Current fuel sulfur regulations have the effect of reducing EFBC by an average of 30% and potentially up to 80% regardless of engine load; a removal rate similar to that of scrubbers. Uncertainties among current observations demonstrate there is a need for more information on (a) the impact of fuel quality on EFBC using robust measurement methods and (b) the efficacy of scrubbers for the removal of particulate matter by size and composition.

Black carbon from ships: a review of the effects of ship speed, fuel quality and exhaust gas scrubbing

NASA Astrophysics Data System (ADS)

Lack, D. A.; Corbett, J. J.

2012-05-01

The International Maritime Organization (IMO) has moved to address the health and climate impact of the emissions from the combustion of low-quality residual fuels within the commercial shipping industry. Fuel sulfur content (FS) limits and an efficiency design index for future ships are examples of such IMO actions. The impacts of black carbon (BC) emissions from shipping are now under review by the IMO, with a particular focus on the potential impacts of future Arctic shipping. Recognizing that associating impacts with BC emissions requires both ambient and onboard observations, we provide recommendations for the measurement of BC. We also evaluate current insights regarding the effect of ship speed (engine load), fuel quality and exhaust gas scrubbing on BC emissions from ships. Observations demonstrate that BC emission factors (EFBC) increases 3 to 6 times at very low engine loads (<25% compared to EFBC at 85-100% load); absolute BC emissions (per nautical mile of travel) also increase up to 100% depending on engine load, even with reduced load fuel savings. If fleets were required to operate at lower maximum engine loads, presumably associated with reduced speeds, then engines could be re-tuned, which would reduce BC emissions. Ships operating in the Arctic are likely running at highly variable engine loads (25-100%) depending on ice conditions and ice breaking requirements. The ships operating at low load may be emitting up to 50% more BC than they would at their rated load. Such variable load conditions make it difficult to assess the likely emissions rate of BC. Current fuel sulfur regulations have the effect of reducing EFBC by an average of 30% and potentially up to 80% regardless of engine load; a removal rate similar to that of scrubbers. Uncertainties among current observations demonstrate there is a need for more information on a) the impact of fuel quality on EFBC using robust measurement methods and b) the efficacy of scrubbers for the removal of particulate matter by size and composition.

Biochar derived from corn straw affected availability and distribution of soil nutrients and cotton yield

PubMed Central

Tian, Xiaofei; Zhang, Min; Wan, Yongshan; Xie, Zhihua; Chen, Baocheng; Li, Wenqing

2018-01-01

Biochar application as a soil amendment has been proposed as a strategy to improve soil fertility and increase crop yields. However, the effects of successive biochar applications on cotton yields and nutrient distribution in soil are not well documented. A three-year field study was conducted to investigate the effects of successive biochar applications at different rates on cotton yield and on the soil nutrient distribution in the 0–100 cm soil profile. Biochar was applied at 0, 5, 10, and 20 t ha-1 (expressed as Control, BC5, BC10, and BC20, respectively) for each cotton season, with identical doses of chemical fertilizers. Biochar enhanced the cotton lint yield by 8.0–15.8%, 9.3–13.9%, and 9.2–21.9% in 2013, 2014, and 2015, respectively, and high levels of biochar application achieved high cotton yields each year. Leaching of soil nitrate was reduced, while the pH values, soil organic carbon, total nitrogen (N), and available K content of the 0–20 cm soil layer were increased in 2014 and 2015. However, the changes in the soil available P content were less substantial. This study suggests that successive biochar amendments have the potential to enhance cotton productivity and soil fertility while reducing nitrate leaching. PMID:29324750

Effects of Wegener-Bergeron-Findeisen Process on Global Black Carbon Distribution

NASA Astrophysics Data System (ADS)

Qi, L.

2016-12-01

In mixed-phase clouds, the Wegener-Bergeron-Findeisen (WBF) process (ice crystals may grow while water drops evaporate, thereby releasing black carbon (BC) particles into the interstitial air) slows down wet scavenging of BC. Rimming (snowflakes fall and collect cloud water drops and the BC in them along their pathways), in contrast, results in more efficient wet scavenging. We systematically investigate the effects of WBF on BC scavenging efficiency, surface BCair, deposition flux, concentration in snow, and washout ratio using a global 3D chemical transport model. We differentiate riming- vs WBF-dominated in-cloud scavenging based on liquid water content and temperature. Specifically, we relate WBF to either temperature or ice mass fraction in mixed-phase clouds. We find that at Jungfraujoch, Switzerland and Abisko, Sweden, where WBF dominates, the discrepancies of simulated BC scavenging efficiency and washout ratio are significantly reduced (from a factor of 3 to 10% and from a factor of 4-5 to a factor of two). However, at Zeppelin, Norway, where riming dominates, simulation of BC scavenging efficiency, BCair, and washout ratio become worse (relative to observations) when WBF is included. There is thus an urgent need for extensive observations to distinguish and characterize riming- versus WBF-dominated aerosol scavenging in mixed-phase clouds and the associated BC scavenging efficiency. We find the reduction resulting from WBF to global BC scavenging efficiency varies substantially, from 8% in the tropics to 76% in the Arctic. The resulting annual mean BCair increases by up to 156% at high altitudes and at northern high latitudes. Overall, WBF halves the model-observation discrepancy (from -65% to -30%) of BCair across North America, Europe, China and the Arctic. Globally WBF increases BC burden from 0.22 to 0.29-0.35 mg m-2 yr-1, which partially explains the gap between observed and previous model simulated BC burdens over land (Bond et al., 2013). In addition, WBF significantly increases BC lifetime from 5.7 days to 8 days. We find that WBF decreases BCsnow at mid-latitudes (by 15%) but increases it in the Arctic (by 26%) while improving model comparisons with observations. In addition, WBF dramatically reduces the model-observation discrepancy of washout ratios in winter (from a factor of 16 to 4).

Arctic Black Carbon Initiative: Reducing Emissions of Black Carbon from Power & Industry in Russia

NASA Astrophysics Data System (ADS)

Cresko, J.; Hodson, E. L.; Cheng, M.; Fu, J. S.; Huang, K.; Storey, J.

2012-12-01

Deposition of black carbon (BC) on snow and ice is widely considered to have a climate warming effect by reducing the surface albedo and promoting snowmelt. Such positive climate feedbacks in the Arctic are especially problematic because rising surface temperatures may trigger the release of large Arctic stores of terrestrial carbon, further amplifying current warming trends. Recognizing the Arctic as a vulnerable region, the U.S. government committed funds in Copenhagen in 2009 for international cooperation targeting Arctic BC emissions reductions. As a result, the U.S. Department of State has funded three research and demonstration projects with the goal to better understand and mitigate BC deposition in the Russian Arctic from a range of sources. The U.S. Department of Energy's (DOE) Arctic BC initiative presented here is focused on mitigating BC emissions resulting from heat and power generation as well as industrial applications. A detailed understanding of BC sources and its transport and fate is required to prioritize efforts to reduce BC emissions from sources that deposit in the Russian Arctic. Sources of BC include the combustion of fossil fuels (e.g. coal, fuel oil, diesel) and the combustion of biomass (e.g. wildfires, agricultural burning, residential heating and cooking). Information on fuel use and associated emissions from the industrial and heat & power sectors in Russia is scarce and difficult to obtain from the open literature. Hence, our project includes a research component designed to locate Arctic BC emissions sources in Russia and determine associated BC transport patterns. We use results from the research phase to inform a subsequent assessment/demonstration phase. We use a back-trajectory modeling method (potential source contribution function - PSCF), which combines multi-year, high-frequency measurements with knowledge about atmospheric transport patterns. The PSCF modeling allows us to map the probability (by season and year) at course resolution (2.5° x 2.5° spatial resolution) that a particular region emits BC which deposits in the Russian Arctic. We utilize data from three Arctic measurement stations during the most recent decade: Alert, Northwest Territories, Canada; Barrow, Alaska; and Tiksi Bay, Russia. To understand more about individual Arctic BC sources, we conduct further research to improve inventory estimates of Russian industrial and energy sector BC emissions. By comparing inventory data on power plant locations and emissions from two publically-available databases (EDGAR-HTAP and CARMA databases) to each other and to additional observations from satellites and the AERONET observation network in Russia, we assess the accuracy of the Russian BC emission inventory in EDGAR-HTAP, a commonly used database for atmospheric transport modeling. We then use a global (GEOS-CHEM) atmospheric transport model to quantify the finer spatial distribution of BC within the Arctic. Lastly, we use data on Russian fuel use combined with published emissions factors to build a national-scale model of energy use and associated emissions from critical industrial and heat & power sources of BC. We use this model to estimate the technical potential of reducing BC emissions through proven mitigation efforts such as improvements in energy efficiency and in emission control technologies.

Energetics of the Brazil Current in the Rio Grande Cone region

NASA Astrophysics Data System (ADS)

Brum, André Lopes; Azevedo, José Luiz Lima de; Oliveira, Leopoldo Rota de; Calil, Paulo Henrique Rezende

2017-10-01

The energetics of the Brazil Current (BC) in the region of the Rio Grande Cone (RGC, 30-35.5°S), a topographic rise in the southwest portion of the Brazilian continental margin, are analyzed using 16 years of numerical data from the Ocean General Circulation Model (OGCM) for the Earth Simulator (OFES). The main focus of this study is the eddy-mean flow interactions of the BC and the local energy budgets in the study region. The kinetic and potential energy balance equations are derived for mean and eddy flows, and the resulting terms are presented and discussed. The eddy-mean flow interactions exhibit complex spatial distributions, and the intensities of the energy budgets decrease with increasing depth. However, only the mean potential energy (MPE) budget decreases southward. Eddy kinetic energy (EKE) and eddy potential energy (EPE) exhibit similar horizontal distribution patterns. Additionally, the baroclinic and barotropic conversion rates increase downstream of the bump, where the eddy energy field exhibits along-stream variability that increases southward. Barotropic conversion is more intense between 50 and 200 m, where mean kinetic energy (MKE) and EKE are concentrated, and it exhibits a horizontal cross-stream variation pattern, with mean-to-eddy energy conversion observed on the offshore side of the BC. This result indicates that the turbulence associated with the stream jet increases as the BC moves away from the coast, with the conversion term acting to stabilize the flow. Baroclinic conversion exhibits a high intensity below 300 m (where MPE and EPE display peaks), and it has a greater influence on the eddy-mean flow interaction than does the barotropic conversion. The RGC directly affects the local dynamics of the BC by increasing the eddy field as soon as the BC reaches the bump. The energy diagrams illustrate a stream characterized by evolving barotropic and baroclinic instability processes throughout the water column. This result indicates an intrinsically unstable jet in the study region. Moreover, baroclinic instability is the main source of EKE in the RGC region.

Anthropogenic iron oxide aerosols enhance atmospheric heating

NASA Astrophysics Data System (ADS)

Moteki, Nobuhiro; Adachi, Kouji; Ohata, Sho; Yoshida, Atsushi; Harigaya, Tomoo; Koike, Makoto; Kondo, Yutaka

2017-05-01

Combustion-induced carbonaceous aerosols, particularly black carbon (BC) and brown carbon (BrC), have been largely considered as the only significant anthropogenic contributors to shortwave atmospheric heating. Natural iron oxide (FeOx) has been recognized as an important contributor, but the potential contribution of anthropogenic FeOx is unknown. In this study, we quantify the abundance of FeOx over East Asia through aircraft measurements using a modified single-particle soot photometer. The majority of airborne FeOx particles in the continental outflows are of anthropogenic origin in the form of aggregated magnetite nanoparticles. The shortwave absorbing powers (Pabs) attributable to FeOx and to BC are calculated on the basis of their size-resolved mass concentrations and the mean Pabs(FeOx)/Pabs(BC) ratio in the continental outflows is estimated to be at least 4-7%. We demonstrate that in addition to carbonaceous aerosols the aggregate of magnetite nanoparticles is a significant anthropogenic contributor to shortwave atmospheric heating.

Breast Reference Set Application: Chris Li-FHCRC (2014) — EDRN Public Portal

Cancer.gov

This application proposes to use Reference Set #1. We request access to serum samples collected at the time of breast biopsy from subjects with IC (n=30) or benign disease without atypia (n=30). Statistical power: With 30 BC cases and 30 normal controls, a 25% difference in mean metabolite levels can be detected between groups with 80% power and α=0.05, assuming coefficients of variation of 30%, consistent with our past studies. These sample sizes appear sufficient to enable detection of changes similar in magnitude to those previously reported in pre-clinical (BC recurrence) specimens (20).

A fractional-N frequency synthesizer for WCDMA/Bluetooth/ZigBee applications

NASA Astrophysics Data System (ADS)

Chunyuan, Zhou; Guolin, Li; Chun, Zhang; Baoyong, Chi; Dongmei, Li; Zhihua, Wang

2009-07-01

A triple-mode fractional-N frequency synthesizer with a noise-filter voltage controlled oscillator (VCO) for WCDMA/Bluetooth/ZigBee applications has been implemented in 0.18-μm RF-CMOS technology. The proposed synthesizer achieves a good phase noise lower than -80 dBc/Hz in band and -115 dBc/Hz@1 MHz for the three modes, and only draws 21 mA from a 1.8 V supply. It has a high hardware sharing and a small size, only 1.5 × 1.4 mm2. The system architecture, circuit design, and measured results are also presented.

[Accelerated partial breast irradiation with multicatheters during breast conserving surgery for cancer].

PubMed

Rodríguez-Spiteri Sagredo, Natalia; Martínez Regueira, Fernando; Olartecoechea Linaje, Begoña; Arredondo Chaves, Jorge; Cambeiro Vázquez, Mauricio; Pina Insausti, Luis Javier; Elizalde Pérez, Arlette; y García-Lallana, Amaya; Sola Gallego, Jose Javier

2013-10-01

Accelerated partial breast irradiation (APBI) with multicatheters after lumpectomy for breast cancer (BC) may be an alternative to whole breast irradiation in selected patients. The aim is to show our 5 year experience. Between June 2007 and June 2012, 87 BC patients have been evaluated for APBI. Inclusion criteria were: age over 40 years, unifocal tumour, infiltrating ductal or intraductal carcinoma, tumour size smaller than 3 cm and no lymph node involvement. Complications, cosmetic results and local and distant recurrences were evaluated. Treatment was completed in 48 patients and contraindicated in 39. The average age of treated patients was 59 years. Operating time was 123 min with 9 implanted catheters in each patient. No complications were observed during surgery or radiotherapy. Patients were discharged from hospital after 4 days. Tumour size was 11 mm. Of these, 35 were infiltrating ductal and 13 intraductal carcinomas. A total of 44 patients received adjuvant treatment. Mean follow-up was 22 months with no evidence of local or distant recurrence. The cosmetic outcome was good or excellent in 66% of cases. APBI with multicatheter placed after lumpectomy for BC is feasible and safe but requires a strict selection of patients. Copyright © 2012 AEC. Published by Elsevier Espana. All rights reserved.

Preparation and evaluation of nanocellulose-gold nanoparticle nanocomposites for SERS applications.

PubMed

Wei, Haoran; Rodriguez, Katia; Renneckar, Scott; Leng, Weinan; Vikesland, Peter J

2015-08-21

Nanocellulose is of research interest due to its extraordinary optical, thermal, and mechanical properties. The incorporation of guest nanoparticles into nanocellulose substrates enables production of novel nanocomposites with a broad range of applications. In this study, gold nanoparticle/bacterial cellulose (AuNP/BC) nanocomposites were prepared and evaluated for their applicability as surface-enhanced Raman scattering (SERS) substrates. The nanocomposites were prepared by citrate mediated in situ reduction of Au(3+) in the presence of a BC hydrogel at 303 K. Both the size and morphology of the AuNPs were functions of the HAuCl4 and citrate concentrations. At high HAuCl4 concentrations, Au nanoplates form within the nanocomposites and are responsible for high SERS enhancements. At lower HAuCl4 concentrations, uniform nanospheres form and the SERS enhancement is dependent on the nanosphere size. The time-resolved increase in the SERS signal was probed as a function of drying time with SERS 'hot-spots' primarily forming in the final minutes of nanocomposite drying. The application of the AuNP/BC nanocomposites for detection of the SERS active dyes MGITC and R6G as well as the environmental contaminant atrazine is illustrated as is its use under low and high pH conditions. The results indicate the broad applicability of this nanocomposite for analyte detection.

Top-down Estimates of Biomass Burning Emissions of Black Carbon in the Western United States

NASA Astrophysics Data System (ADS)

Mao, Y.; Li, Q.; Randerson, J. T.; Liou, K.

2011-12-01

We apply a Bayesian linear inversion to derive top-down estimates of biomass burning emissions of black carbon (BC) in the western United States (WUS) for May-November 2006 by inverting surface BC concentrations from the IMPROVE network using the GEOS-Chem chemical transport model. Model simulations are conducted at both 2°×2.5° (globally) and 0.55°×0.66° (nested over North America) horizontal resolutions. We first improve the spatial distributions and seasonal and interannual variations of the BC emissions from the Global Fire Emissions Database (GFEDv2) using MODIS 8-day active fire counts from 2005-2007. The GFEDv2 emissions in N. America are adjusted for three zones: boreal N. America, temperate N. America, and Mexico plus Central America. The resulting emissions are then used as a priori for the inversion. The a posteriori emissions are 2-5 times higher than the a priori in California and the Rockies. Model surface BC concentrations using the a posteriori estimate provide better agreement with IMPROVE observations (~20% increase in the Taylor skill score), including improved ability to capture the observed variability especially during June-July. However, model surface BC concentrations are still biased low by ~30%. Comparisons with the Fire Locating and Modeling of Burning Emissions (FLAMBE) are included.

Top-down Estimates of Biomass Burning Emissions of Black Carbon in the Western United States

NASA Astrophysics Data System (ADS)

Mao, Y.; Li, Q.; Randerson, J. T.; CHEN, D.; Zhang, L.; Liou, K.

2012-12-01

We apply a Bayesian linear inversion to derive top-down estimates of biomass burning emissions of black carbon (BC) in the western United States (WUS) for May-November 2006 by inverting surface BC concentrations from the IMPROVE network using the GEOS-Chem chemical transport model. Model simulations are conducted at both 2°×2.5° (globally) and 0.5°×0.667° (nested over North America) horizontal resolutions. We first improve the spatial distributions and seasonal and interannual variations of the BC emissions from the Global Fire Emissions Database (GFEDv2) using MODIS 8-day active fire counts from 2005-2007. The GFEDv2 emissions in N. America are adjusted for three zones: boreal N. America, temperate N. America, and Mexico plus Central America. The resulting emissions are then used as a priori for the inversion. The a posteriori emissions are 2-5 times higher than the a priori in California and the Rockies. Model surface BC concentrations using the a posteriori estimate provide better agreement with IMPROVE observations (~50% increase in the Taylor skill score), including improved ability to capture the observed variability especially during June-September. However, model surface BC concentrations are still biased low by ~30%. Comparisons with the Fire Locating and Modeling of Burning Emissions (FLAMBE) are included.

Trends of HIV-1 Subtypes Among Young People in Hangzhou, China.

PubMed

Zhang, Wenjun; Chen, Junfang; Pan, Xiaohong; Zhang, Jiafeng; Guo, Zhihong; Luo, Yan; Yang, Jiezhe; Xia, Yan; He, Lin; Xu, Yun; Xu, Ke; Ding, Xiaobei

2017-03-01

To investigate the HIV-1 molecular epidemiology among young people (18 to 25 years old) in Hangzhou. Plasma samples from 262 newly diagnosed HIV-1-infected patients were collected between 2009 and 2013 from Hangzhou of Zhejiang province. HIV-1 nucleotide sequences of pol gene regions were amplified using a nested polymerase chain reaction method and sequenced. Phylogenetic and recombination analyses were used to determine the HIV-1 genotypes. Based on all sequences generated, the subtype/circulating recombinant forms (CRFs) distribution was as follows: CRF01_AE (68.70%), CRF07_BC (21.54%), subtype B (3.66%), CRF08_BC (2.44%), 01B (2.03%), BC (0.81%), and C (0.41%). We found that the percentage of CRF07_BC was increasing year by year among young people in Hangzhou. Novel CRFs such as CRF67_01B (HZ2011-15 CD4-4516) and CRF68_01B (HZ2011-20 CD4-4530 and HZ2011-29 CD4-4087) were first discovered in the area in this study. Our study presents a molecular epidemiology investigation describing the structure of HIV-1 strains cocirculating in young people in Hangzhou. Increasing CRF07_BC and new CRFs popular in young people are a challenge for future prevention in Hangzhou.

Variability of Black Carbon Deposition to the East Antarctic Plateau, 1800-2000 AD

NASA Technical Reports Server (NTRS)

Bisiaux, M. M.; Edwards, R.; McConnell, J. R.; Albert, M. R.; Anschutz, H.; Neumann, T. A.; Isaksson, E.; Penner, J. E.

2012-01-01

Refractory black carbon aerosols (rBC) from biomass burning and fossil fuel combustion are deposited to the Antarctic ice sheet and preserve a history of emissions and long-range transport from low- and mid-latitudes. Antarctic ice core rBC records may thus provide information with respect to past combustion aerosol emissions and atmospheric circulation. Here, we present six East Antarctic ice core records of rBC concentrations and fluxes covering the last two centuries with approximately annual resolution (cal. yr. 1800 to 2000). The ice cores were drilled in disparate regions of the high East Antarctic ice sheet, at different elevations and net snow accumulation rates. Annual rBC concentrations were log-normally distributed and geometric means of annual concentrations ranged from 0.10 to 0.18 m cro-g/kg. Average rBC fluxes were determined over the time periods 1800 to 2000 and 1963 to 2000 and ranged from 3.4 to 15.5 m /a and 3.6 to 21.8 micro-g/sq m/a, respectively. Geometric mean concentrations spanning 1800 to 2000 increased linearly with elevation at a rate of 0.025 micro-g/kg/500 m. Spectral analysis of the records revealed significant decadal-scale variability, which at several sites was comparable to decadal ENSO variability.

Vertical dependence of black carbon, sulphate and biomass burning aerosol radiative forcing

NASA Astrophysics Data System (ADS)

Samset, Bjørn H.; Myhre, Gunnar

2011-12-01

A global radiative transfer model is used to calculate the vertical profile of shortwave radiative forcing from a prescribed amount of aerosols. We study black carbon (BC), sulphate (SO4) and a black and organic carbon mixture typical of biomass burning (BIO), by prescribing aerosol burdens in layers between 1000 hPa and 20 hPa and calculating the resulting direct radiative forcing divided by the burden (NDRF). We find a strong sensitivity in the NDRF for BC with altitude, with a tenfold increase between BC close to the surface and the lower part of the stratosphere. Clouds are a major contributor to this dependence with altitude, but other factors also contribute. We break down and explain the different physical contributors to this strong sensitivity. The results show a modest regional dependence of the altitudinal dependence of BC NDRF between industrial regions, while for regions with properties deviating from the global mean NDRF variability is significant. Variations due to seasons and interannual changes in cloud conditions are found to be small. We explore the effect that large altitudinal variation in NDRF may have on model estimates of BC radiative forcing when vertical aerosol distributions are insufficiently constrained, and discuss possible applications of the present results for reducing inter-model differences.

The polygalacturonase gene BcMF2 from Brassica campestris is associated with intine development

PubMed Central

Huang, Li; Cao, Jiashu; Zhang, Aihong; Ye, Yiqun; Zhang, Yuchao; Liu, Tingting

2009-01-01

Brassica campestris Male Fertility 2 (BcMF2) is a putative polygalacturonase (PG) gene previously isolated from the flower bud of Chinese cabbage (Brassica campestris L. ssp. chinensis Makino, syn. B. rapa ssp. chinensis). This gene was found to be expressed specifically in tapetum and pollen after the tetrad stage of anther development. Antisense RNA technology was used to study the function of BcMF2 in Chinese cabbage. Scanning and transmission electron microscopy revealed that there were deformities in the transgenic mature pollen grains such as abnormal location of germinal furrows. In addition, the homogeneous pectic exintine layer facing the exterior seemed to be overdeveloped and predominantly occupied the intine, thus reversing the normal proportional distribution of the internal endintine layer and the external exintine layer. Since it is a continuation of the intine layer, the pollen tube wall could not grow normally. This resulted in the formation of a balloon-like swelling structure in the pollen tube tip in nearly 80% of the transgenic pollen grains. Premature degradation of tapetum was also found in these transgenic plants, which displayed decreased expression of the BcMF2 gene. BcMF2 might therefore encode a new PG with an important role in pollen wall development, possibly via regulation of pectin's dynamic metabolism. PMID:19039102

Tumour Necrosis Factor-α Gene Polymorphism Is Associated with Metastasis in Patients with Triple Negative Breast Cancer.

PubMed

Li, Hui-Hui; Zhu, Hui; Liu, Li-Sheng; Huang, Yong; Guo, Jun; Li, Jie; Sun, Xin-Ping; Chang, Chun-Xiao; Wang, Zhe-Hai; Zhai, Kan

2015-07-13

Tumour necrosis factor-α (TNF-α) is critical in the regulation of inflammation and tumour progression. TNF-α-308G > A is associated with constitutively elevated TNF-α expression. The purpose of this study was to assess the association between TNF-α-308G > A and breast cancer (BC) risk by subtype and the connection between genotypes and clinical features of BC. A total of 768 patients and 565 controls were enrolled in this study, and genotypes were detected using the TaqMan assay. No effect on susceptibility for any BC subtype was found for the TNF-α-308 polymorphism in our study or in the pooled meta-analysis. This polymorphism was shown to be associated with age at menarche in all BC and in progesterone receptor-negative BC. Interestingly, triple negative breast cancer (TNBC) patients with TNF-α-308A had an increased risk of distant tumour metastasis (OR = 3.80, 95% CI: 1.31-11.02, P = 0.009). Multi-regression analysis showed that TNF-α-308A was also a risk factor for distant tumour metastasis after adjustment for tumour size and lymph node metastasis status (OR = 6.26, 95% CI: 1.88-20.87, P = 0.003). These findings indicate that TNF-α might play a distinct role in the progression of TNBC, especially in distant tumour metastasis of TNBC.

Longitudinal leading-twist distribution amplitude of the J /ψ meson within the background field theory

NASA Astrophysics Data System (ADS)

Fu, Hai-Bing; Zeng, Long; Cheng, Wei; Wu, Xing-Gang; Zhong, Tao

2018-04-01

We make a detailed study on the J /ψ meson longitudinal leading-twist distribution amplitude ϕ2;J /ψ ∥ by using the QCD sum rules within the background field theory. By keeping all the nonperturbative condensates up to dimension 6, we obtain accurate QCD sum rules for the moments ⟨ξn;J /ψ ∥⟩. The first three ones are ⟨ξ2;J /ψ ∥⟩=0.083 (12 ), ⟨ξ4;J /ψ ∥⟩=0.015 (5 ), and ⟨ξ6;J /ψ ∥⟩=0.003 (2 ), respectively. Those values indicate a single peaked behavior for ϕ2;J /ψ ∥. As an application, we adopt the QCD light-cone sum rules to calculate the Bc meson semileptonic decay Bc+→J /ψ ℓ+νℓ. We obtain Γ (Bc+→J /ψ ℓ+νℓ)=(89.67-19.06+24.76)×10-15 GeV and ℜ(J /ψ ℓ+νℓ)=0.21 7-0.057+0.069, which agree with both the extrapolated next-to-leading order pQCD prediction and the new CDF measurement within errors.

An AeroCom assessment of black carbon in Arctic snow and sea ice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiao, C.; Flanner, M. G.; Balkanski, Y.

2014-01-01

Though many global aerosols models prognose surface deposition, only a few models have been used to directly simulate the radiative effect from black carbon (BC) deposition to snow and sea ice. In this paper, we apply aerosol deposition fields from 25 models contributing to two phases of the Aerosol Comparisons between Observations and Models (AeroCom) project to simulate and evaluate within-snow BC concentrations and radiative effect in the Arctic. We accomplish this by driving the offline land and sea ice components of the Community Earth System Model with different deposition fields and meteorological conditions from 2004 to 2009, during whichmore » an extensive field campaign of BC measurements in Arctic snow occurred. We find that models generally underestimate BC concentrations in snow in northern Russia and Norway, while overestimating BC amounts elsewhere in the Arctic. Although simulated BC distributions in snow are poorly correlated with measurements, mean values are reasonable. The multi-model mean (range) bias in BC concentrations, sampled over the same grid cells, snow depths, and months of measurements, are -4.4 (-13.2 to +10.7) ng g -1 for an earlier phase of AeroCom models (phase I), and +4.1 (-13.0 to +21.4) ng g -1 for a more recent phase of AeroCom models (phase II), compared to the observational mean of 19.2 ng g -1. Factors determining model BC concentrations in Arctic snow include Arctic BC emissions, transport of extra-Arctic aerosols, precipitation, deposition efficiency of aerosols within the Arctic, and meltwater removal of particles in snow. Sensitivity studies show that the model–measurement evaluation is only weakly affected by meltwater scavenging efficiency because most measurements were conducted in non-melting snow. The Arctic (60–90° N) atmospheric residence time for BC in phase II models ranges from 3.7 to 23.2 days, implying large inter-model variation in local BC deposition efficiency. Combined with the fact that most Arctic BC deposition originates from extra-Arctic emissions, these results suggest that aerosol removal processes are a leading source of variation in model performance. The multi-model mean (full range) of Arctic radiative effect from BC in snow is 0.15 (0.07–0.25) W m -2 and 0.18 (0.06–0.28) W m -2 in phase I and phase II models, respectively. After correcting for model biases relative to observed BC concentrations in different regions of the Arctic, we obtain a multi-model mean Arctic radiative effect of 0.17 W m -2 for the combined AeroCom ensembles. Finally, there is a high correlation between modeled BC concentrations sampled over the observational sites and the Arctic as a whole, indicating that the field campaign provided a reasonable sample of the Arctic.« less

Tobacco smoking patterns and differential food effects on prostate and breast cancers among smokers and nonsmokers in Córdoba, Argentina.

PubMed

Román, María D; Niclis, Camila; Tumas, Natalia; Díaz, María Del Pilar; Osella, Alberto R; Muñoz, Sonia E

2014-07-01

The aim of this study was to estimate the effect of diet on prostate and breast cancer (PC and BC) risks in smokers and nonsmokers and to explore the effect modification between smoking and dietary patterns. PC or BC incidence rates were assessed spatially according to tobacco exposure, age-adjusted standardization using lung cancer mortality as a proxy. Two case-control studies were carried out in Argentina (2008-2012). Participants were interviewed about their diet, smoking habits, and other lifestyle factors. Multilevel models were fitted including family history of cancer as the random intercept for the second level, and diet and lifestyle variables as covariates. Tobacco exposure was aggregated spatially. Family history of cancer significantly accounts for PC and BC. In smokers, high intake of fat meat increased PC and BC risks [odds ratio (OR) 1.56, 95% confidence interval (CI) 0.81-3.05 and OR 6.01, 95% CI 1.99-8.19, respectively]. PC and BC risks were also greater in smokers with high intakes of fatty foods (OR 1.95, 95% CI 1.09-3.50 and OR 24.2, 95% CI 0.82-7.21, respectively). Moderate intake of nonstarchy vegetables and risk of PC were inversely associated in nonsmokers (OR 0.55, 95% CI 0.20-1.48). In smoker women, BC risk was associated with sweet drink consumption (OR 2.96, 95% CI 1.10-7.92) and ethanol intake (OR 5.15, 95% CI 1.88-14.16). Spatial distributions of cancer incidence rates match those of tobacco exposure. Differential effects of diet on PC and BC risks were found in smokers and nonsmokers.

Spatiotemporal Association of Real-Time Concentrations of Black Carbon (BC) with Fine Particulate Matters (PM2.5) in Urban Hotspots of South Korea.

PubMed

Kim, Sungroul; Yu, Sol; Yun, Dongmin

2017-11-06

We evaluated the spatiotemporal distributions of black carbon (BC) and particulate matters with aerodynamic diameters of less than 2.5 m (PM 2.5 ) concentrations at urban diesel engine emission (DEE) hotspots of South Korea. Concentrations of BC and PM 2.5 were measured at the entrance gate of two diesel bus terminals and a train station, in 2014. Measurements were conducted simultaneously at the hotspot (Site 1) and at its adjacent, randomly selected, residential areas, apartment complex near major roadways, located with the same direction of 300 m (Site 2) and 500 m (Site 3) away from Site 1 on 4 different days over the season, thrice per day; morning ( n = 120 measurements for each day and site), evening ( n = 120), and noon ( n = 120). The median (interquartile range) PM 2.5 ranged from 12.6 (11.3-14.3) to 60.1 (47.0-76.0) μg/m³ while those of BC concentrations ranged from 2.6 (1.9-3.7) to 6.3 (4.2-10.3) μg/m³. We observed a strong relationship of PM 2.5 concentrations between sites (slopes 0.89-0.9, the coefficient of determination 0.89-0.96) while the relationship for BC concentrations between sites was relatively weak (slopes 0.76-0.85, the coefficient of determination 0.54-0.72). PM 2.5 concentrations were changed from 4% to 140% by unit increase of BC concentration, depending on site and time while likely supporting the necessity of monitoring of BC as well as PM 2.5 , especially at urban DEE related hotspot areas.

Temporal Trends and Future Prediction of Breast Cancer Incidence Across Age Groups in Trivandrum, South India.

PubMed

Mathew, Aleyamma; George, Preethi Sara; Arjunan, Asha; Augustine, Paul; Kalavathy, Mc; Padmakumari, G; Mathew, Beela Sarah

2016-01-01

Increasing breast cancer (BC) incidence rates have been reported from India; causal factors for this increased incidence are not understood and diagnosis is mostly in advanced stages. Trivandrum exhibits the highest BC incidence rates in India. This study aimed to estimate trends in incidence by age from 2005- 2014, to predict rates through 2020 and to assess the stage at diagnosis of BC in Trivandrum. BC cases were obtained from the Population Based Cancer Registry, Trivandrum. Distribution of stage at diagnosis and incidence rates of BC [Age-specific (ASpR), crude (CR) and age-standardized (ASR)] are described and employed with a joinpoint regression model to estimate average annual percent changes (AAPC) and a Bayesian model to estimate predictive rates. BC accounts for 31% (2681/8737) of all female cancers in Trivandrum. Thirty-five percent (944/2681) are <50 years of age and only 9% present with stage I disease. Average age increased from 53 to 56.4 years (p=0.0001), CR (per 105 women) increased from 39 (ASR: 35.2) to 55.4 (ASR: 43.4), AAPC for CR was 5.0 (p=0.001) and ASR was 3.1 (p=0.001). Rates increased from 50 years. Predicted ASpR is 174 in 50-59 years, 231 in > 60 years and overall CR is 80 (ASR: 57) for 2019- 20. BC, mostly diagnosed in advanced stages, is rising rapidly in South India with large increases likely in the future; particularly among post-menopausal women. This increase might be due to aging and/or changes in lifestyle factors. Reasons for the increased incidence and late stage diagnosis need to be studied.

Processing of micro-nano bacterial cellulose with hydrolysis method as a reinforcing bioplastic

NASA Astrophysics Data System (ADS)

Maryam, Maryam; Dedy, Rahmad; Yunizurwan, Yunizurwan

2017-01-01

Nanotechnology is the ability to create and manipulate atoms and molecules on the smallest of scales. Their size allows them to exhibit novel and significantly improved physical, chemical, biological properties, phenomena, and processes because of their size. The purpose of this research is obtaining micro-nano bacterial cellulose as reinforcing bioplastics. Bacterial cellulose (BC) was made from coconut water for two weeks. BC was dried and grinded. Bacterial cellulose was given purification process with NaOH 5% for 6 hours. Making the micro-nano bacterial cellulose with hydrolysis method. Hydrolysis process with hydrochloric acid (HCl) at the conditions 3,5M, 55°C, 6 hours. Drying process used spray dryer. The hydrolysis process was obtained bacterial cellulose with ±7 μm. The addition 2% micro-nano bacterial cellulose as reinforcing in bioplastics composite can improve the physical characteristics.

National Register Testing at 23BE1007, 23BE1008, and 23BE1010, Downstream from the Harry S. Truman Dam and Reservoir, Benton County, Missouri.

DTIC Science & Technology

1988-01-01

major biomes of North America --the oak-hickory forest and the bluestem prairie (Fig. 5). The composition and distribution of these biomes have been...Paleo-Indian Period in North America is a distinct cultural tradition appearing between 12,000 B.C. and 8,000 B.C. Chapman (1975:30) refers to this...throughout North America . Cultural adaptations to this new ecological order resulted in the replace- ment of Paleo-Indian technologies with a new

Light and the City: Breast Cancer Risk Factors Differ Between Urban and Rural Women in Israel.

PubMed

Keshet-Sitton, Atalya; Or-Chen, Keren; Yitzhak, Sara; Tzabary, Ilana; Haim, Abraham

2017-06-01

Women are exposed to indoor and outdoor artificial light at night (ALAN) in urban and rural environments. Excessive exposure to hazardous ALAN containing short wavelength light may suppress pineal melatonin production and lead to an increased breast cancer (BC) risk. Our objective was to address the differences in BC risks related to light exposure in urban and rural communities. We examined indoor and outdoor light habits of BC patients and controls that had lived in urban and rural areas in a 5-year period, 10 to 15 years before the time of the study. Individual data, night time sleeping habits and individual exposure to ALAN habits were collected using a questionnaire. A total of 252 women (110 BC patients and 142 controls) participated in this study. The sample was divided to subgroups according to dwelling area and disease status. Age matching was completed between all subgroups. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated for urban and rural women separately, using binary logistic regression. OR results of urban population (92 BC patients and 72 control) revealed that BC risk increases with daily use of cellphone (OR = 2.13, 95% CI = 1.01-4.49, P < .05) and residence near strong ALAN sources (OR = 1.51, 95% CI = 0.99-2.30, P < .06). Nevertheless, BC risk decreases if a woman was born in Israel (OR = 0.44, 95% CI = 0.21-0.93, P < .03), longer sleep duration (OR = 0.75, 95% CI = 0.53-1.05, P < .1), and reading with bed light illumination before retiring to sleep (OR = 0.77, 95% CI = 0.61-0.96, P < .02). Furthermore, in the rural population (18 BC patients and 66 control) BC risk increases with the number of years past since the last menstruation (OR = 1.12, 95% CI = 1.03-1.22, P < .01). However, BC risk decreases with longer sleep duration (OR = 0.53, 95% CI = 0.24-1.14, P < .1), reading with room light illumination before retiring to sleep (OR = 0.55, 95% CI = 0.29-1.06, P < .07), and sleeping with closed shutters during the night (OR = 0.66, 95% CI = 0.41-1.04, P < .08). These data support the idea that indoor and outdoor nighttime light exposures differ between urban and rural women. Therefore, we suggest that women can influence BC risk and incidence by applying protective personal lighting habits. Further studies with larger sample sizes are needed to strengthen the results.

Monthly and spatially resolved black carbon emission inventory of India: uncertainty analysis

NASA Astrophysics Data System (ADS)

Paliwal, Umed; Sharma, Mukesh; Burkhart, John F.

2016-10-01

Black carbon (BC) emissions from India for the year 2011 are estimated to be 901.11 ± 151.56 Gg yr-1 based on a new ground-up, GIS-based inventory. The grid-based, spatially resolved emission inventory includes, in addition to conventional sources, emissions from kerosene lamps, forest fires, diesel-powered irrigation pumps and electricity generators at mobile towers. The emissions have been estimated at district level and were spatially distributed onto grids at a resolution of 40 × 40 km2. The uncertainty in emissions has been estimated using a Monte Carlo simulation by considering the variability in activity data and emission factors. Monthly variation of BC emissions has also been estimated to account for the seasonal variability. To the total BC emissions, domestic fuels contributed most significantly (47 %), followed by industry (22 %), transport (17 %), open burning (12 %) and others (2 %). The spatial and seasonal resolution of the inventory will be useful for modeling BC transport in the atmosphere for air quality, global warming and other process-level studies that require greater temporal resolution than traditional inventories.

NLO QCD corrections to B c( B*c) production around the Z pole at an e + e - collider

NASA Astrophysics Data System (ADS)

Zheng, XuChang; Chang, ChaoHsi; Feng, TaiFu; Pan, Zan

2018-03-01

The production of B c and B*c mesons at a Z-factory (an e + e - collider operating at energies around the Z pole) is calculated up to the next-to-leading order (NLO) QCD accuracy. The results show that the dependence of the total cross sections on the renormalization scale μ is suppressed by the corrections, and the NLO corrections enhance the total cross sections of B c by 52% and of B*c by 33% when the renormalization scale is taken at μ = 2 m b . To observe the various behaviors of the production of the mesons B c and B*c, such as the differential cross section vs. the out-going angle, the forward-backward asymmetry, and the distribution vs. the energy fraction z up to NLO QCD accuracy as well as the relevant K-factor (NLO to LO) for the production, are calculated, and it is pointed out that some of the observables obtained in the present work may be used as a specific precision test of the standard model.

Acoustic characteristics of modern Greek Orthodox Church music.

PubMed

Delviniotis, Dimitrios S

2013-09-01

Some acoustic characteristics of the two types of vocal music of the Greek Orthodox Church Music, the Byzantine chant (BC) and ecclesiastical speech (ES), are studied in relation to the common Greek speech and the Western opera. Vocal samples were obtained, and their acoustic parameters of sound pressure level (SPL), fundamental frequency (F0), and the long-time average spectrum (LTAS) characteristics were analyzed. Twenty chanters, including two chanters-singers of opera, sang (BC) and read (ES) the same hymn of Byzantine music (BM), the two opera singers sang the same aria of opera, and common speech samples were obtained, and all audio were analyzed. The distribution of SPL values showed that the BC and ES have higher SPL by 9 and 12 dB, respectively, than common speech. The average F0 in ES tends to be lower than the common speech, and the smallest standard deviation (SD) of F0 values characterizes its monotonicity. The tone-scale intervals of BC are close enough to the currently accepted theory with SD equal to 0.24 semitones. The rate and extent of vibrato, which is rare in BC, equals 4.1 Hz and 0.6 semitones, respectively. The average LTAS slope is greatest in BC (+4.5 dB) but smaller than in opera (+5.7 dB). In both BC and ES, instead of a singer's formant appearing in an opera voice, a speaker's formant (SPF) was observed around 3300 Hz, with relative levels of +6.3 and +4.6 dB, respectively. The two vocal types of BM, BC, and ES differ both to each other and common Greek speech and opera style regarding SPL, the mean and SD of F0, the LTAS slope, and the relative level of SPF. Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Broad-Range PCR Coupled with Electrospray Ionization Time of Flight Mass Spectrometry for Detection of Bacteremia and Fungemia in Patients with Neutropenic Fever.

PubMed

Desmet, S; Maertens, J; Bueselinck, K; Lagrou, K

2016-10-01

Infection is an important complication in patients with hematologic malignancies or solid tumors undergoing intensive cytotoxic chemotherapy. In only 20 to 30% of the febrile neutropenic episodes, an infectious agent is detected by conventional cultures. In this prospective study, the performance of broad-range PCR coupled with electrospray ionization time of flight mass spectrometry (PCR/ESI-MS) technology was compared to conventional blood cultures (BC) in a consecutive series of samples from high-risk hematology patients. In 74 patients, BC and a whole-blood sample for PCR/ESI-MS (Iridica BAC BSI; Abbott, Carlsbad, CA, USA) were collected at the start of each febrile neutropenic episode and, in case of persistent fever, also at day 5. During 100 different febrile episodes, 105 blood samples were collected and analyzed by PCR/ESI-MS. There was evidence of a bloodstream infection (BSI) in 36/105 cases (34%), based on 14 cases with both PCR/ESI-MS and BC positivity, 17 cases with BC positivity only, and 5 cases with PCR/ESI-MS positivity only. The sensitivity of PCR/ESI-MS was 45%, specificity was 93%, and the negative predictive value was 80% compared to blood culture. PCR/ESI-MS detected definite pathogens (Fusobacterium nucleatum and Streptococcus pneumoniae) missed by BC, whereas it missed both Gram-negative and Gram-positive organisms detected by BC. PCR/ESI-MS testing detected additional microorganisms but showed a low sensitivity (45%) compared to BC in neutropenic patients. Our results indicate a lower concordance between BC and PCR/ESI-MS in the neutropenic population than what has been previously reported in other patient groups with normal white blood cell distribution, and a lower sensitivity than other PCR-based methods. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Simple model for lambda-doublet propensities in bimolecular reactions

NASA Technical Reports Server (NTRS)

Bronikowski, Michael J.; Zare, Richard N.

1990-01-01

A simple geometric model is presented to account for lambda-doublet propensities in bimolecular reactions A + BC - AB + C. It applies to reactions in which AB is formed in a pi state, and in which the unpaired molecular orbital responsible for lambda-doubling arises from breaking the B-C bond. The lambda-doublet population ratio is predicted to be 2:1 provided that: (1) the motion of A in the transition state determines the plane of rotation of AB; (2) the unpaired pi orbital lying initially along the B-C bond may be resolved into a projection onto the AB plane of rotation and a projection perpendicular to this plane; (3) there is no preferred geometry for dissociation of ABC. The 2:1 lambda-doublet ratio is the 'unconstrained dynamics prior' lambda-doublet distribution for such reactions.

Holocene flood stack from three Eifel maar lakes

NASA Astrophysics Data System (ADS)

Brunck, Heiko; Sirocko, Frank

2015-04-01

Lacustrine sediments are very sensitive to natural and anthropogenically enviromental changes. Thus, lake sediments are excellent climate archives and can be used for reconstructions of past precipitation and flood events. However, we extend our flood record for MIS 2/3 to the entire Holocene up to recent years to get a complete flood stack for the last 60 000 years. The present study reconstructs paleo floods from event layers in the sediment, of Schalkenmehren Maar (SM3), Ulmen Maar (UM1) and Holzmaar (HM1) combined with recent gauge time-series. All three maar lakes has an inflow by a local stream. Accordingly the sedimentation rate is directly linked to runoff activity and the bioturbation was low so that event layers become visible, but varves are only preserved in lake Holzmaar. The maar sites are situated in the Eifel near to the town of Daun and were drilled in the ELSA (Eifel Laminated Sediment archive) project. The Eifel area is well suited to approximate Central European weather, because modern water level gauge data from Eifel rivers correlate with respective data from the Rhine (Wernli and Pfahl, 2009). Combined sedimentological, paleobotanical and geochemical data received from SM3, UM1 and HM1 builds the foundation of the 14C based chronology. The synchronisation of the record is controlled by tephra time markers and pollen. Both are used to align the main cores of the ELSA project and construct an integrated age model for the last 220 000 years [b2k] (Förster and Sirocko, 2014). For the extension of our MIS 2/3 flood stack we used the Laacher See Tephra (10 900 BC) as marker for the correlation with the Holocene cores. To study the flood events in detail, 10 cm long thin sections were used to distinguish flood layers from distal turbidites. Turbidites have a continuous grain size gradation; the grains size profile of flood events is in contrast characterized by several grain size maxima over the entire layer thickness. A flood event over several days shows numerous peaks of intense discharge, which lead to a discontinuous grain size gradient. The thickness of each flood layer was measured for the classification of the event intensity. As a consequence, 118 flood layers over 7.5 mm thickness were detected in all 3 cores. Flood layers in the interval 10 900 BC up to 4000 BC are not as clearly visible in Holzmaar or Schalkenmehrener Maar as during the later Holocene (when humans cultivated the landscape) but visible flood layers are regularly observed in the record from Ulmen. The Flood layers from 4000 BC up to now are most common in the medieval and Roman sections of the cores; the major events have occurred at 1342 AD, 800 BC and 2100 BC. Our time-series represents the first highly-resolved chronology for flood events from 60 000 years until present times and indicates variable periodicities of flood activity linked to predominant climatic and anthropogenic development.

Comparison of human platelet lysate alternatives using expired and freshly isolated platelet concentrates for adipose-derived stromal cell expansion.

PubMed

Dessels, Carla; Durandt, Chrisna; Pepper, Michael S

2018-03-19

Pooled human platelet lysate (pHPL) has been used to expand adipose-derived stromal cells (ASCs) and can be formulated using fresh or expired buffy coats (BCs) which are then resuspended in either plasma or an additive solution. Not much is known about the effects that expired products and additive solutions have on ASC expansion, and the need for quality control and release criteria has been expressed. This pilot study compared proliferation, cell size, morphology and immunophenotype of ASCs expanded in the different pHPL alternatives versus foetal bovine serum (FBS). Quality control criteria were assessed prior to and during the manufacture of the pHPL alternatives. ASCs were then expanded in 1%, 2.5%, 5% or 10% of the different pHPL alternatives or in 10% FBS. Cell size, morphology, cell number and immunophenotype were measured using microscopy and flow cytometry. The majority of the pHPL alternatives were within the recommended ranges for the quality control criteria. ASCs expanded in the pHPL alternatives were smaller in size, displayed a tighter spindle-shaped morphology, increased cell growth and had a similar immunophenotype (with the exception of CD34 and CD36) when compared to ASCs expanded in FBS. Here we report on the effects that expired BC products and additive solutions have on ASC expansion. When taken together, our findings indicate that all of the pHPL alternatives can be considered to be suitable replacements for FBS for ASC expansion, and that expired BC products can be used as an alternative to fresh BC products.

Contributions of dynamic environmental signals during life-cycle transitions to early life-history traits in lodgepole pine (Pinus contorta Dougl.)

NASA Astrophysics Data System (ADS)

Liu, Y.; Wang, T.; El-Kassaby, Y. A.

2015-08-01

Environmental signals are important triggers in the life-cycle transitions and play a crucial role in the life-history evolution. Yet, very little is known about the leading ecological factors contributing to the variations of life-history traits in perennial plants. This paper explores both the causes and consequences for the evolution of life-history traits (i.e., seed dormancy and size) in lodgepole pine (Pinus contorta Dougl.) across British Columbia (B.C.), Canada. We selected 83 logepole pine populations covering 22 ecosystem zones of B.C. and through their geographic coordinate, 197 climatic variables were generated accordingly for the reference (1961-1990) and future (2041-2070) periods. We found that dynamic climatic variables rather than constant geographic variables are the true environmental driving forces in seed dormancy and size variations and thus provide reliable predictors in response to global climate change. Evapotranspiration and precipitation in the plant-to-seed chronology are the most critical climate variables for seed dormancy and size variations, respectively. Hence, we predicted that levels of seed dormancy in lodgepole pine would increase across large tracts of B.C. in 2050s. Winter-chilling is able to increase the magnitude of life-history plasticity and lower the bet-hedge strategy in the seed-to-plant transition; however, winter-chilling is likely to be insufficient in the north of 49° N in 2050s, which may delay germination while unfavourable conditions during dry summers may result in adverse consequences in the survival of seedlings owing to extended germination span.

A New Paradigm for Teaching Histology Laboratories in Canada's First Distributed Medical School

ERIC Educational Resources Information Center

Pinder, Karen E.; Ford, Jason C.; Ovalle, William K.

2008-01-01

To address the critical problem of inadequate physician supply in rural British Columbia, The University of British Columbia (UBC) launched an innovative, expanded and distributed medical program in 2004-2005. Medical students engage in a common curriculum at three geographically distinct sites across B.C.: in Vancouver, Prince George and…

Microbial interactions in marine water amended by eroded benthic biofilm: A case study from an intertidal mudflat

NASA Astrophysics Data System (ADS)

Montanié, Hélène; Ory, Pascaline; Orvain, Francis; Delmas, Daniel; Dupuy, Christine; Hartmann, Hans J.

2014-09-01

In shallow macrotidal ecosystems with large intertidal mudflats, the sediment-water coupling plays a crucial role in structuring the pelagic microbial food web functioning, since inorganic and organic matter and microbial components (viruses and microbes) of the microphytobenthic biofilm can be suspended toward the water column. Two experimental bioassays were conducted in March and July 2008 to investigate the importance of biofilm input for the pelagic microbial and viral loops. Pelagic inocula (< 0.6 μ- and < 10 μ filtrates) were diluted either with < 30 kDa-ultrafiltered seawater or with this ultrafiltrate enriched with the respective size-fractionated benthic biofilm or with < 30 kDa-benthic compounds (BC). The kinetics of heterotrophic nanoflagellates (HNF), bacteria and viruses were assessed together with bacterial and viral genomic fingerprints, bacterial enzymatic activities and viral life strategies. The experimental design allowed us to evaluate the effect of BC modulated by those of benthic size-fractionated microorganisms (virus + bacteria, + HNF). BC presented (1) in March, a positive effect on viruses and bacteria weakened by pelagic HNF. Benthic microorganisms consolidated this negative effect and sustained the viral production together with a relatively diverse and uneven bacterial assemblage structure; (2) in July, no direct impact on viruses but a positive effect on bacteria modulated by HNF, which indirectly enhanced viral multiplication. Both effects were intensified by benthic microorganisms and bacterial assemblage structure became more even. HNF indirectly profited from BC more in March than in July. The microbial loop would be stimulated by biofilm during periods of high resources (March) and the viral loop during periods of depleted resources (July).

The World Health Organization 1973 classification system for grade is an important prognosticator in T1 non-muscle-invasive bladder cancer.

PubMed

van de Putte, Elisabeth E Fransen; Bosschieter, Judith; van der Kwast, Theo H; Bertz, Simone; Denzinger, Stefan; Manach, Quentin; Compérat, Eva M; Boormans, Joost L; Jewett, Michael A S; Stoehr, Robert; van Leenders, Geert J L H; Nieuwenhuijzen, Jakko A; Zlotta, Alexandre R; Hendricksen, Kees; Rouprêt, Morgan; Otto, Wolfgang; Burger, Maximilian; Hartmann, Arndt; van Rhijn, Bas W G

2018-04-10

To compare the prognostic value of the World Health Organization (WHO) 1973 and 2004 classification systems for grade in T1 bladder cancer (T1-BC), as both are currently recommended in international guidelines. Three uro-pathologists re-revised slides of 601 primary (first diagnosis) T1-BCs, initially managed conservatively (bacille Calmette-Guérin) in four hospitals. Grade was defined according to WHO1973 (Grade 1-3) and WHO2004 (low-grade [LG] and high-grade [HG]). This resulted in a lack of Grade 1 tumours, 188 (31%) Grade 2, and 413 (69%) Grade 3 tumours. There were 47 LG (8%) vs 554 (92%) HG tumours. We determined the prognostic value for progression-free survival (PFS) and cancer-specific survival (CSS) in Cox-regression models and corrected for age, sex, multiplicity, size and concomitant carcinoma in situ. At a median follow-up of 5.9 years, 148 patients showed progression and 94 died from BC. The WHO1973 Grade 3 was negatively associated with PFS (hazard ratio [HR] 2.1) and CSS (HR 3.4), whilst WHO2004 grade was not prognostic. On multivariable analysis, WHO1973 grade was the only prognostic factor for progression (HR 2.0). Grade 3 tumours (HR 3.0), older age (HR 1.03) and tumour size >3 cm (HR 1.8) were all independently associated with worse CSS. The WHO1973 classification system for grade has strong prognostic value in T1-BC, compared to the WHO2004 system. Our present results suggest that WHO1973 grade cannot be replaced by the WHO2004 classification in non-muscle-invasive BC guidelines. © 2018 The Authors BJU International © 2018 BJU International Published by John Wiley & Sons Ltd.

Assessment of the systemic distribution of a bioconjugated anti-Her2 magnetic nanoparticle in a breast cancer model by means of magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Huerta-Núñez, L. F. E.; Villanueva-Lopez, G. Cleva; Morales-Guadarrama, A.; Soto, S.; López, J.; Silva, J. G.; Perez-Vielma, N.; Sacristán, E.; Gudiño-Zayas, Marco E.; González, C. A.

2016-09-01

The aim of this study was to determine the systemic distribution of magnetic nanoparticles of 100 nm diameter (MNPs) coupled to a specific monoclonal antibody anti-Her2 in an experimental breast cancer (BC) model. The study was performed in two groups of Sprague-Dawley rats: control ( n = 6) and BC chemically induced ( n = 3). Bioconjugated "anti-Her2-MNPs" were intravenously administered, and magnetic resonance imaging (MRI) monitored its systemic distribution at seven times after administration. Non-heme iron presence associated with the location of the bioconjugated anti-Her2-MNPs in splenic, hepatic, cardiac and tumor tissues was detected by Perl's Prussian blue (PPB) stain. Optical density measurements were used to semiquantitatively determine the iron presence in tissues on the basis of a grayscale values integration of T1 and T2 MRI sequence images. The results indicated a delayed systemic distribution of MNPs in cancer compared to healthy conditions with a maximum concentration of MNPs in cancer tissue at 24 h post-infusion.

A cross-sectional study of elderly Asian and European women with primary operable breast cancer aged 70 and older. Are there differences?

PubMed

Tea, Muy-Kheng M; Tang, Lichen; Di, Gen-Hong; Muin, Dana; Steurer, Stefan; Delancey, James W; Shao, Zhi-Ming; Singer, Christian F

2012-11-01

Breast cancer (BC) is becoming a disease of the elderly. Additionally, BC-incidence is rising in Asia. The aim of this study was to explore clinico-pathological characteristics and differences of breast cancer in elderly Asian/Han-Chinese compared to Caucasian/Austrian women. A total number of 630 consecutive primary operable, unilateral breast cancer cases, 70 years and older, were analyzed. Histo-pathological findings and biological characteristics of 198 Caucasian/Austrian were compared with 432 Asian/Han-Chinese. Pearson's chi-square test was used to assess differences in the analyzed populations. A significantly higher rate of triple-negative BC (p=0.027) was diagnosed among the Chinese geriatric population. More estrogen-receptor positive BC was detected in the Caucasian study group (p<0.001). No statistically significant differences were detected based on tumor size, axillary lymph-node status, nor HER2-receptor expression. This study will help us gain additional ethnic-specific insight into the biological characteristics of breast cancer in the elderly Caucasian/Austrian and Asian/Han-Chinese populations. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Black carbon over the Amazon during SAMBBA: it gets everywhere

NASA Astrophysics Data System (ADS)

Morgan, W.; Allan, J. D.; Flynn, M.; Darbyshire, E.; Liu, D.; Szpek, K.; Langridge, J.; Johnson, B. T.; Haywood, J.; Longo, K.; Artaxo, P.; Coe, H.

2014-12-01

Biomass burning represents a major source of Black Carbon (BC) aerosol to the atmosphere, which can result in major perturbations to weather, climate and ecosystem development. Large uncertainties in these impacts prevail, particularly on regional scales. One such region is the Amazon Basin, where large, intense and frequent burning occurs on an annual basis during the dry season. Absorption by atmospheric aerosols is underestimated by models over South America, which points to significant uncertainties relating to BC aerosol properties. Results from the South American Biomass Burning Analysis (SAMBBA) field experiment, which took place during September and October 2012 over Brazil on-board the UK Facility for Airborne Atmospheric Measurement (FAAM) BAe-146 research aircraft, are presented here. Aerosol chemical composition was measured by a DMT Single Particle Soot Photometer (SP2) and an Aerodyne Aerosol Mass Spectrometer (AMS). The physical, chemical and optical properties of BC-containing particles across the region will be characterised, with particular emphasis on the vertical distribution. BC was ubiquitous across the region, with measurements extending from heavily deforested regions in the Western Amazon Basin, through to agricultural fires in the Cerrado (Savannah-like) region and more pristine areas over the Amazon Rainforest. Measurements in the vicinity of Manaus (a city located deep into the jungle) were also conducted. BC concentrations peaked within the boundary layer at a height of around 1.5km. BC-containing particles were found to be rapidly coated in the near-field, with little evidence for additional coating upon advection and dilution. Biomass burning layers within the free troposphere were routinely observed. BC-containing particles within such layers were typically associated with less coating than those within the boundary layer, suggestive of wet removal of more coated BC particles. The importance of such properties in relation to the optical properties of BC and its resultant impact will be investigated. The prevalence of elevated biomass burning layers above the frequent build-up of shallow cumulus clouds during the afternoon will also be characterised. This will provide improved constraint upon the highly uncertain impact of biomass burning aerosol over the region.

Field assessment of the impacts of landscape structure on different-sized airborne particles in residential areas of Beijing, China

NASA Astrophysics Data System (ADS)

Fan, Shuxin; Li, Xiaopeng; Han, Jing; Cao, Yu; Dong, Li

2017-10-01

In high-density metropolis, residential areas are important human living environments. Aimed at investigating the impacts of landscape structure on the levels of different-sized airborne particle in residential areas, we conducted field monitoring of the levels of TSP, PM10, PM2.5 and PM1 using mobile traverses in 18 residential areas during the daytime in winter (Dec. 2015-Feb. 2016) and summer (Jun.-Aug. 2016) in Beijing, China. The net concentration differences (d) of the four-sized particles (dTSP, dPM10, dPM2.5 and dPM1) between residential environments and nearby corresponding urban backgrounds, which can be regarded as the reduction of particle concentration in residential environments, were calculated. The effects and relative contributions of different landscape structure parameters on these net concentration differences were further investigated. Results showed that the distribution of particle concentrations has great spatial variation in urban environments. Within the residential environment, there were overall lower concentrations of the four-sized particles compared with the nearby urban background. The net concentration differences of the four-sized particles were all significantly different among the 18 studied residential areas. The average dTSP, dPM10, dPM2.5 and dPM1 reached 18.92, 12.28, 2.01 and 0.53 μg/m3 in summer, and 9.91, 7.81, 1.39 and 0.38 μg/m3 in winter, respectively. The impacts and relative contribution of different landscape structure parameters on the reductions of TSP, PM10, PM2.5 and PM1 in residential environments differed and showed seasonal variation. Percentage of vegetation cover (PerVC) and building cover (PerBC) had the greatest impact. A 10% increase in PerVC would increase about 5.03, 8.15, 2.16 and 0.20 μg/m3 of dTSP, dPM10, dPM2.5 and dPM1 in summer, and a 10% increase in PerBC would decreased about 41.37, 16.54, 2.47 and 0.95 μg/m3 of them in winter. Increased vegetation coverage and decreased building construction were found to be conducive to ameliorate airborne particle levels in residential environments. Moreover, landscape structure parameters can be served as indicators for predicting the potential particle reduction at local scale.

3-Dimensional Microstructure of Al-Al3Ti Alloy Severely Deformed by ECAP

NASA Astrophysics Data System (ADS)

Sato, Hisashi; Hishikawa, Takahisa; Makino, Yuuki; Kunimine, Takahiro; Watanabe, Yoshimi

Microstructure of Al-Al3Ti alloy deformed by Equal-Channel-Angular Pressing (ECAP) is 3-dimensionally investigated. Especially, distribution of Al3Ti particles is focused in this study. The Al-Al3Ti alloy has coarse Al3Ti platelet particles in α-Al matrix. When the Al-Al3Ti alloy is deformed by ECAP under route A, fine Al3Ti platelet particles are observed. These Al3Ti platelet particles are aligned along to deformation axis, and its plane normal is perpendicular to the deformation axis. On the other hand, Al-Al3Ti alloy ECAPed under route Bc forms several groups consisted of fine Al3Ti platelet particles. Moreover, longitudinal size of the Al3Ti particle groups is close to that of initial Al3Ti particles with 4-pass ECAP specimen. These distribution behaviors of the Al3Ti particle can be explained by plastic flow of α-Al matrix. Finally, it is concluded that distribution of Al3Ti particle in Al-Al3Ti alloy by ECAP is controlled by plastic deformation of α-Al matrix.

Identification of arginine and its "Downstream" molecules as potential markers of breast cancer.

PubMed

Hu, Lu; Gao, Yu; Cao, Yunfeng; Zhang, Yinxu; Xu, Minghao; Wang, Yuanyuan; Jing, Yu; Guo, Shengnan; Jing, Fangyu; Hu, Xiaodan; Zhu, Zhitu

2016-10-01

Breast cancer (BC) is the most commonly diagnosed cancer in women worldwide. Arginine is a semiessential amino acid in humans and is essential for several biological pathways in malignant and normal cells, such as ornithine and N1, N12-diacetylspermine (DiAcSpm). This study aimed to determine the role of arginine and these downstream molecules in BC. Plasma arginine, ornithine, and arginine-to-ornithine ratio (AOR) were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Urine samples were measured by the colloid gold aggregation to test determination of urinary diAcSpm. A principal component analysis was performed to evaluate the results observed between breast tumor and control characteristics. Differences in individual metabolite concentrations between BC patients and controls were tested by receiver operating characteristics (ROC) analyses. Student's t tests were used to detect the differences between two groups of normally distributed variables, and Wilcoxon sign rank tests were performed for asymmetrically distributed variables. As we analyzed, BC patients had lower plasma arginine and arginine/ornithine level, and higher plasma ornithine and urinary DiAcSpm concentrations as compared with control patients (P = 0.028, 0.020, 0.002, and 0.011, respectively). And the ROC curve was drawn and the area under the curve of the metabolites was calculated to be 0.659 (P = 0.028), 0.645 (P = 0.045), 0.7233 (P = 0.002), 0.683 (P = 0.011), respectively. In addition, our analysis showed that arginine concentrations and AOR had a positive correlation with ER status, while ornithine had a negative correlation with T stage (P = 0.042, 0.023, respectively).In conclusion, arginine and these downstream molecules were biomarkers for BC. More studies are needed to highlight the theoretical strengths. © 2016 IUBMB Life, 68(10):817-822, 2016. © 2016 International Union of Biochemistry and Molecular Biology.

Elemental distribution in ascending aortic after radiotherapy and chemotherapy by Low Energy X-ray Fluorescence spectroscopy

NASA Astrophysics Data System (ADS)

Mantuano, A.; Mota, C. L.; Pickler, A.; Sena, G.; Braz, D.; Salata, C.; de Almeida, C. E.; Costa, F. N.; Barroso, R. C.

2018-05-01

Breast cancer (BC) is the most frequent cancer and the leading cause of cancer-related mortality in women. The treatment techniques for the BC include chemotherapy (CT) and/or radiotherapy (RT) and can modify elementary the cell matrix by calcificating tissues due to biological and morphological changes. Also, treatments for BC induce cardiotoxicity and it is important to understand the mechanisms involved in order to prevent this late effect in treated breast cancer patients. The high incidence of cardiovascular mortality in breast cancer patients is partially credited to increased intimal and medial calcifications of the aorta. The aim of this work is to investigate the distibution of low atomic number elements such as Magnesium (Mg), due to its importance for the cardiac metabolism; iron (Fe), since BC treatment may be associated with oxidative stress; and Sodium (Na), that is extremely related to the damage of endothelial cells. An optimal technique to observe these changes in aorta tissue is soft X-ray FLuorescence that can provide elemental maps of these important elements. The results performed by Low Energy X-ray Fluorescence LEXRF analyses showed that when the tissue is submitted to treatments with CT and/or RT, some normal structures become disorganized, and consequently the intensity of elemental compounds can be changed. All the experiments were carried out at the TwinMic beamline at Elettra Synchrotron facility using as animal model Wistar rats in order to evaluate the distribution of Na, Mg and Fe in aorta walls of Wistar rats, after BC treatment. Simultaneous acquisition of LEXRF and attenuation coefficient maps suggest that the combined chemotherapy and radiotherapy caused more damage to the aortic tissue as compared to radiation therapy alone. These findings add an in-depth understanding of elemental lack or excess in the tissue and contribute to locate these changes.

Light-absorbing impurities in a southern Tibetan Plateau glacier: Variations and potential impact on snow albedo and radiative forcing

NASA Astrophysics Data System (ADS)

Li, Xiaofei; Kang, Shichang; Zhang, Guoshuai; Qu, Bin; Tripathee, Lekhendra; Paudyal, Rukumesh; Jing, Zhefan; Zhang, Yulan; Yan, Fangping; Li, Gang; Cui, Xiaoqing; Xu, Rui; Hu, Zhaofu; Li, Chaoliu

2018-02-01

Light-absorbing impurities (LAIs), such as organic carbon (OC), black carbon (BC), and mineral dust (MD), deposited on the surface snow of glacier can reduce the surface albedo. As there exists insufficient knowledge to completely characterize LAIs variations and difference in LAIs distributions, it is essential to investigate the behaviors of LAIs and their influence on the glaciers across the Tibetan Plateau (TP). Therefore, surface snow and snowpit samples were collected during September 2014 to September 2015 from Zhadang (ZD) glacier in the southern TP to investigate the role of LAIs in the glacier. LAIs concentrations were observed to be higher in surface aged snow than in the fresh snow possibly due to post-depositional processes such as melting or sublimation. The LAIs concentrations showed a significant spatial distribution and marked negative relationship with elevation. Impurity concentrations varied significantly with depth in the vertical profile of the snowpit, with maximum LAIs concentrations frequently occurred in the distinct dust layers which were deposited in non-monsoon, and the bottom of snowpit due to the eluviation in monsoon. Major ions in snowpit and backward trajectory analysis indicated that regional activities and South Asian emissions were the major sources. According to the SNow ICe Aerosol Radiative (SNICAR) model, the average simulated albedo caused by MD and BC in aged snow collected on 31 May 2015 accounts for about 13% ± 3% and 46% ± 2% of the albedo reduction. Furthermore, we also found that instantaneous RF caused by MD and BC in aged snow collected on 31 May 2015 varied between 4-16 W m- 2 and 7-64 W m- 2, respectively. The effect of BC exceeds that of MD on albedo reduction and instantaneous RF in the study area, indicating that BC played a major role on the surface of the ZD glacier.

Prevalence of ERα-397 PvuII C/T, ERα-351 XbaI A/G and PGR PROGINS polymorphisms in Brazilian breast cancer-unaffected women

PubMed Central

Giacomazzi, J.; Aguiar, E.; Palmero, E.I.; Schmidt, A.V.; Skonieski, G.; Filho, D.D.; Bock, H.; Saraiva-Pereira, M.L.; Ewald, I.P.; Schuler-Faccini, L.; Camey, S.A.; Caleffi, M.; Giugliani, R.; Ashton-Prolla, P.

2012-01-01

Polymorphisms of hormone receptor genes have been linked to modifications in reproductive factors and to an increased risk of breast cancer (BC). In the present study, we have determined the allelic and genotypic frequencies of the ERα-397 PvuII C/T, ERα-351 XbaI A/G and PGR PROGINS polymorphisms and investigated their relationship with mammographic density, body mass index (BMI) and other risk factors for BC. A consecutive and unselected sample of 750 Brazilian BC-unaffected women enrolled in a mammography screening program was recruited. The distribution of PGR PROGINS genotypic frequencies was 72.5, 25.5 and 2.0% for A1A1, A1A2 and A2A2, respectively, which was equivalent to that encountered in other studies with healthy women. The distribution of ERα genotypes was: ERα-397 PvuII C/T: 32.3% TT, 47.5% TC, and 20.2% CC; ERα-351 XbaI A/G: 46.3% AA, 41.7% AG and 12.0% GG. ERα haplotypes were 53.5% PX, 14.3% Px, 0.3% pX, and 32.0% px. These were significantly different from most previously published reports worldwide (P < 0.05). Overall, the PGR PROGINS genotypes A2A2 and A1A2 were associated with fatty and moderately fatty breast tissue. The same genotypes were also associated with a high BMI in postmenopausal women. In addition, the ERα-351 XbaI GG genotype was associated with menarche ≥12 years (P = 0.02). ERα and PGR polymorphisms have a phenotypic effect and may play an important role in BC risk determination. Finally, if confirmed in BC patients, these associations could have important implications for mammographic screening and strategies and may be helpful to identify women at higher risk for the disease. PMID:22584640

Wintertime aerosol in Las Vegas, Nevada

NASA Astrophysics Data System (ADS)

Brown, Steven G.

Numerous studies have found adverse health effects in subjects who live next to major roadways due to air pollution; in particular, there can be severe impacts on lung function and development in children living and/or attending school next to major roadways due to their exposure to air pollutants, including particulate matter (PM) or aerosol. The composition of aerosol at an elementary school next to a major freeway in Las Vegas, Nevada during winter 2008 was measured using a suite of measurements. An Aerodyne High Resolution Aerosol Mass Spectrometer (HR-AMS) was used to quantify the composition of non-refractory PM1 aerosol, including organic matter (OM); an Aethalometer was used to quantify black carbon (BC); a Sunset OCEC analyzer was used to measure organic and elemental carbon (OC, EC); and a particle-into-liquid system (PILS) coupled to two ion chromatographs (IC) was used to measure fine particle ions. Hi-volume PM2.5 samplers were used to collect aerosol on quartz fiber filters at between 2 and 24 hour intervals during the study, a subset of which were analyzed for PAHs and the biomass burning tracer levoglucosan. Data were analyzed by positive matrix factorization (PMF) to determine the amount of fresh, hydrocarbon-like organic aerosol (HOA), more oxidized OA (low-volatility and semi-volatile OA [LV-OOA, SV-OOA]) and biomass burning OA (BBOA). PM1 aerosol was predominantly carbonaceous, with OM plus BC accounting for 74% of the overall average 6.9 mug/m3 of PM measured. BC had a diurnal pattern similar to traffic volume, while OM was higher in the evening compared to the morning. OM was a mixture of fresh HOA, urban- and regional-scale OOA, and BBOA; in the evening, SV-OOA and BBOA peaked, while HOA concentrations were on average the same in the morning and evening, similar to BC. OM/OC ratios were low (1.52 +/-0.14 on average) during the morning rush hour (average OM = 2.4 mug/m3) when vehicular emissions dominate this near-road measurement site, and even lower (1.46 +/- 0.10) in the evening (average OM=6.3 mug/m3), when a combination of vehicular and fresh residential biomass burning emissions was typically present during a period characterized by strong atmospheric stability. While nitrate and sulfate had size distributions typical of secondary species with a sharp peak in particle diameter between 400 nm and 500 nm, OM had a broader distribution between 100 nm and 400 nm diameter particles, reflecting its combination of fresh, smaller particles and aged, larger particles. OM concentrations were on average similar between periods when the sampling site was upwind and downwind of the freeway, though during the morning OM concentrations were higher under downwind conditions, as was the fraction of HOA.

Aerosols at the Poles: An Aerocom Phase II Multi-Model Evaluation

NASA Technical Reports Server (NTRS)

Sand, Maria; Bauer, Susanne E.; Samset, Bjorn H.; Balkanski, Yves; Bellouin, Nicolas; Berntsen, Terje K.; Bian, Huisheng; Chin, Mian; Diehl, Thomas; Easter, Richard;

Aerosols at the poles: an AeroCom Phase II multi-model evaluation

NASA Astrophysics Data System (ADS)

Sand, Maria; Samset, Bjørn H.; Balkanski, Yves; Bauer, Susanne; Bellouin, Nicolas; Berntsen, Terje K.; Bian, Huisheng; Chin, Mian; Diehl, Thomas; Easter, Richard; Ghan, Steven J.; Iversen, Trond; Kirkevåg, Alf; Lamarque, Jean-François; Lin, Guangxing; Liu, Xiaohong; Luo, Gan; Myhre, Gunnar; van Noije, Twan; Penner, Joyce E.; Schulz, Michael; Seland, Øyvind; Skeie, Ragnhild B.; Stier, Philip; Takemura, Toshihiko; Tsigaridis, Kostas; Yu, Fangqun; Zhang, Kai; Zhang, Hua

2017-10-01

Atmospheric aerosols from anthropogenic and natural sources reach the polar regions through long-range transport and affect the local radiation balance. Such transport is, however, poorly constrained in present-day global climate models, and few multi-model evaluations of polar anthropogenic aerosol radiative forcing exist. Here we compare the aerosol optical depth (AOD) at 550 nm from simulations with 16 global aerosol models from the AeroCom Phase II model intercomparison project with available observations at both poles. We show that the annual mean multi-model median is representative of the observations in Arctic, but that the intermodel spread is large. We also document the geographical distribution and seasonal cycle of the AOD for the individual aerosol species: black carbon (BC) from fossil fuel and biomass burning, sulfate, organic aerosols (OAs), dust, and sea-salt. For a subset of models that represent nitrate and secondary organic aerosols (SOAs), we document the role of these aerosols at high latitudes.The seasonal dependence of natural and anthropogenic aerosols differs with natural aerosols peaking in winter (sea-salt) and spring (dust), whereas AOD from anthropogenic aerosols peaks in late spring and summer. The models produce a median annual mean AOD of 0.07 in the Arctic (defined here as north of 60° N). The models also predict a noteworthy aerosol transport to the Antarctic (south of 70° S) with a resulting AOD varying between 0.01 and 0.02. The models have estimated the shortwave anthropogenic radiative forcing contributions to the direct aerosol effect (DAE) associated with BC and OA from fossil fuel and biofuel (FF), sulfate, SOAs, nitrate, and biomass burning from BC and OA emissions combined. The Arctic modelled annual mean DAE is slightly negative (-0.12 W m-2), dominated by a positive BC FF DAE in spring and a negative sulfate DAE in summer. The Antarctic DAE is governed by BC FF. We perform sensitivity experiments with one of the AeroCom models (GISS modelE) to investigate how regional emissions of BC and sulfate and the lifetime of BC influence the Arctic and Antarctic AOD. A doubling of emissions in eastern Asia results in a 33 % increase in Arctic AOD of BC. A doubling of the BC lifetime results in a 39 % increase in Arctic AOD of BC. However, these radical changes still fall within the AeroCom model range.

The impact of overweight and obesity on breast cancer: data from Switzerland, so far a country little affected by the current global obesity epidemic.

PubMed

Kann, Simone; Schmid, Seraina Margaretha; Eichholzer, Monika; Huang, Dorothy Jane; Amann, Esther; Güth, Uwe

2014-08-01

This review presents results from the project "The Impact of Overweight/Obesity on Breast Cancer: data from Switzerland". Swiss data is interesting because the general female population is distinctive in two areas when compared to that of most other industrialized countries: Switzerland has comparatively low rates of overweight (22-23%) and obesity (7-8%) and has rather stable rates of overweight and obesity. The entire project comprised three major issues: (I) etiology of breast cancer (BC). There is a consistently shown association between obesity and postmenopausal BC risk in countries with high obesity prevalence rates in the literature. In our Swiss study group, however, we did not find higher rates of overweight and obesity in postmenopausal BC cases than in the general population. A possible explanation for this observation may be a curvilinear dose-response relationship between BMI and postmenopausal BC risk, so that an increased risk may only be observed in populations with a high prevalence of obese/very obese women; (II) tumor characteristics. BMI was significantly associated with tumor size; this applied not only to the cases where the tumor was found by self-detection, but also to lesions detected by radiological breast examinations. In addition, a higher BMI was positively correlated with advanced TNM stage, unfavorable grading and a higher St. Gallen risk score. No associations were observed between BMI and histological subtype, estrogen receptor status, HER2 status and triple negative BC; (III) patient compliance and persistence towards adjuvant BC therapy. Many studies found that the prognosis of overweight/obese BC patients was significantly lower than that of normal weight patients. However, failure of compliance and persistence towards therapy on the part of the patient is not a contributing factor for this observed unfavorable prognosis. In most therapy modes, patients with increasing BMI demonstrated greater motivation and perseverance towards the recommended treatment.

From Early Domesticated Rice of the Middle Yangtze Basin to Millet, Rice and Wheat Agriculture: Archaeobotanical Macro-Remains from Baligang, Nanyang Basin, Central China (6700–500 BC)

PubMed Central

Deng, Zhenhua; Qin, Ling; Gao, Yu; Weisskopf, Alison Ruth; Zhang, Chi; Fuller, Dorian Q.

2015-01-01

Baligang is a Neolithic site on a northern tributary of the middle Yangtze and provides a long archaeobotanical sequence from the Seventh Millennium BC upto the First Millennium BC. It provides evidence for developments in rice and millet agriculture influenced by shifting cultural affiliation with the north (Yangshao and Longshan) and south (Qujialing and Shijiahe) between 4300 and 1800 BC. This paper reports on plant macro-remains (seeds), from systematic flotation of 123 samples (1700 litres), producing more than 10,000 identifiable remains. The earliest Pre-Yangshao occupation of the sites provide evidence for cultivation of rice (Oryza sativa) between 6300–6700 BC. This rice appears already domesticated in on the basis of a dominance of non-shattering spikelet bases. However, in terms of grain size changes has not yet finished, as grains are still thinner than more recent domesaticated rice and are closer in grain shape to wild rices. This early rice was cultivated alongside collection of wild staple foods, especially acorns (Quercus/Lithicarpus sensu lato). In later periods the sites has evidence for mixed farming of both rice and millets (Setaria italica and Panicum miliaceum). Soybean appears on the site in the Shijiahe period (ca.2500 BC) and wheat (Triticum cf. aestivum) in the Late Longshan levels (2200–1800 BC). Weed flora suggests an intensification of rice agriculture over time with increasing evidence of wetland weeds. We interpret these data as indicating early opportunistic cultivation of alluvial floodplains and some rainfed rice, developing into more systematic and probably irrigated cultivation starting in the Yangshao period, which intensified in the Qujialing and Shijiahe period, before a shift back to an emphasis on millets with the Late Longshan cultural influence from the north. PMID:26460975

Ancient jades map 3,000 years of prehistoric exchange in Southeast Asia

PubMed Central

Hung, Hsiao-Chun; Iizuka, Yoshiyuki; Bellwood, Peter; Nguyen, Kim Dung; Bellina, Bérénice; Silapanth, Praon; Dizon, Eusebio; Santiago, Rey; Datan, Ipoi; Manton, Jonathan H.

2007-01-01

We have used electron probe microanalysis to examine Southeast Asian nephrite (jade) artifacts, many archeologically excavated, dating from 3000 B.C. through the first millennium A.D. The research has revealed the existence of one of the most extensive sea-based trade networks of a single geological material in the prehistoric world. Green nephrite from a source in eastern Taiwan was used to make two very specific forms of ear pendant that were distributed, between 500 B.C. and 500 A.D., through the Philippines, East Malaysia, southern Vietnam, and peninsular Thailand, forming a 3,000-km-diameter halo around the southern and eastern coastlines of the South China Sea. Other Taiwan nephrite artifacts, especially beads and bracelets, were distributed earlier during Neolithic times throughout Taiwan and from Taiwan into the Philippines. PMID:18048347

Ancient jades map 3,000 years of prehistoric exchange in Southeast Asia.

PubMed

Hung, Hsiao-Chun; Iizuka, Yoshiyuki; Bellwood, Peter; Nguyen, Kim Dung; Bellina, Bérénice; Silapanth, Praon; Dizon, Eusebio; Santiago, Rey; Datan, Ipoi; Manton, Jonathan H

2007-12-11

We have used electron probe microanalysis to examine Southeast Asian nephrite (jade) artifacts, many archeologically excavated, dating from 3000 B.C. through the first millennium A.D. The research has revealed the existence of one of the most extensive sea-based trade networks of a single geological material in the prehistoric world. Green nephrite from a source in eastern Taiwan was used to make two very specific forms of ear pendant that were distributed, between 500 B.C. and 500 A.D., through the Philippines, East Malaysia, southern Vietnam, and peninsular Thailand, forming a 3,000-km-diameter halo around the southern and eastern coastlines of the South China Sea. Other Taiwan nephrite artifacts, especially beads and bracelets, were distributed earlier during Neolithic times throughout Taiwan and from Taiwan into the Philippines.

Feasibility of the mobile mindfulness-based stress reduction for breast cancer (mMBSR(BC)) program for symptom improvement among breast cancer survivors.

PubMed

Lengacher, Cecile A; Reich, Richard R; Ramesar, Sophia; Alinat, Carissa B; Moscoso, Manolete; Cousin, Lakeshia; Marino, Victoria R; Elias, Maya N; Paterson, Carly L; Pleasant, Michelle L; Rodriguez, Carmen S; Wang, Hsiao-Lan; Kip, Kevin E; Meng, Hongdao; Park, Jong Y

2018-02-01

The purpose of this pilot study was to test the feasibility of delivering the mobile mindfulness-based stress reduction for breast cancer (mMBSR(BC)) program using an iPad and to evaluate its impact on symptom improvement. A single group, pre-posttest design was implemented among female stages 0-III breast cancer survivors (BCS) who completed treatment. Data were collected at baseline and week 6 on measures of psychological and physical symptoms and quality of life. The mMBSR(BC) program is a standardized, stress-reducing intervention that combines sitting and walking meditation, body scan, and yoga and is designed to deliver weekly 2-hour sessions for 6 weeks using an iPad. The mean age of the 15 enrolled BCS was 57 years; one participant was non-Hispanic black, and 14 were non-Hispanic white. Of the 13 who completed the study, there were significant improvements from baseline to 6 weeks post-mMBSR(BC) in psychological and physical symptoms of depression, state anxiety, stress, fear of recurrence, sleep quality, fatigue, and quality of life (P's < .05). Effect sizes for improvements of multiple symptoms ranged from medium to large. These results provide preliminary support that the mMBSR(BC) program may be feasible and acceptable, showing a clinical impact on decreasing psychological and physical symptoms. This mobile-based program offers a delivery of a standardized MBSR(BC) intervention to BCS that is convenient for their own schedule while decreasing symptom burden in the survivorship phase after treatment for breast cancer. Copyright © 2017 John Wiley & Sons, Ltd.

Association of the Joint Effect of Menopause and Hormone Replacement Therapy and Cancer in African American Women: The Jackson Heart Study

PubMed Central

Campbell Jenkins, Brenda W.; Addison, Clifton; Wilson, Gregory; Liu, Jiankang; Fortune, Melody; Robinson, Kiana; White, Monique; Sarpong, Daniel

2011-01-01

Cancer is the second leading cause of death in the US and in Mississippi. Breast cancer (BC) is the most common cancer among women, and the underlying pathophysiology remains unknown, especially among African American (AA) women. The study purpose was to examine the joint effect of menopause status (MS) and hormone replacement therapy (HRT) on the association with cancers, particularly BC using data from the Jackson Heart Study. The analytic sample consisted of 3202 women between 35 and 84 years of which 73.7% and 22.6% were postmenopausal and on HRT, respectively. There were a total of 190 prevalent cancer cases (5.9%) in the sample with 22.6% breast cancer cases. Menopause (p < 0.0001), but not HRT (p = 0.6402), was independently associated with cancer. Similar results were obtained for BC. BC, cancer, hypertension, type 2 diabetes, prevalent cardiovascular disease, physical activity and certain dietary practices were all significantly associated with the joint effect of menopause and HRT in the unadjusted analyses. The family history of cancer was the only covariate that was significantly associated with cancer in the age-adjusted models. In examining the association of cancer and the joint effect of menopause and HRT, AA women who were menopausal and were not on HRT had a 1.97 (95% CI: 1.15, 3.38) times odds of having cancer compared to pre-menopausal women after adjusting for age; which was attenuated after further adjusting for family history of cancer. Given that the cancer and BC cases were small and key significant associations were attenuated after adjusting for the above mentioned covariates, these findings warrant further investigation in studies with larger sample sizes of cancer (and BC) cases. PMID:21776241

Heart rate variability measure in breast cancer patients and survivors: A systematic review.

PubMed

Arab, Claudia; Dias, Daniel Penteado Martins; Barbosa, Renata Thaís de Almeida; Carvalho, Tatiana Dias de; Valenti, Vitor Engrácia; Crocetta, Tânia Brusque; Ferreira, Marcelo; Abreu, Luiz Carlos de; Ferreira, Celso

2016-06-01

In the current study, we aimed to review literature findings showing the clinical importance of cardiac autonomic modulation assessed by heart rate variability analysis in breast cancer (BC) patients and survivors. We conducted a systematic review according to The PRISMA Statement in Medline, Scopus and Web of Science (_-2015) databases. The search was limited to articles in English language, published in peer-reviewed journals, and with adult age samples only (e.g., women, patients, or survivors, diagnosed with BC in any stage). We included observational studies and randomized trials. Detailed heart rate variability analysis (instruments, data collection protocol, and analysis methods) was required. Search terms included autonomic nervous system, heart rate variability, sympathetic and parasympathetic nervous system, autonomic dysfunction, vagal nervous and breast neoplasms, breast cancer and breast tumor. Twelve studies were included in this review. The clinical importance of cardiac autonomic modulation assessed by heart rate variability analysis in BC patients and survivors is demonstrated by association with effects of BC surgery, and treatments, and the adverse effects of surgery and treatments on survivors (e.g., cardiotoxicity, fatigue, and stress). The strength of evidence of included studies is low: small samples size and heterogeneity, presence of confounders, and observational studies design. The heart rate variability analysis could be used as a complementary non-invasive tool for the early diagnosis and better prognosis of autonomic dysfunction, and survival in BC patients. There are many potential clinical applications of heart rate variability analysis in BC patients, and the employment of such approaches could lead to lower impairment of autonomic function in this individuals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Overexpression of SLC34A2 is an independent prognostic indicator in bladder cancer and its depletion suppresses tumor growth via decreasing c-Myc expression and transcriptional activity

PubMed Central

Ye, Wen; Chen, Cui; Gao, Ying; Zheng, Zou-Shan; Xu, Yi; Yun, Miao; Weng, Hui-Wen; Xie, Dan; Ye, Sheng; Zhang, Jia-Xing

2017-01-01

Solute carrier family 34 member 2 (SLC34A2), a pH-sensitive sodium-dependent phosphate transporter, is associated with several human cancers. In this study, we investigate the clinical significance of SLC34A2 and its function in human bladder cancer (BC). The expression dynamics of SLC34A2 were examined in two independent cohorts of BC samples by quantitative PCR, western blotting and immunohistochemical staining. In the training cohort (156 cases), we applied the X-tile program software to assess the optimal cutoff points for biomarkers in order to accurately classify patients according to clinical outcome. In the validation cohort (130 cases), the cutoff score derived from X-title analysis was investigated to determine the association of SLC34A2 expression with survival outcome. A series of in vitro and in vivo assays were then performed to elucidate the function of SLC34A2 in BC and its underlying mechanisms. Results showed that SLC34A2 was significantly upregulated in BC cell lines and clinical samples. In both two cohorts of BC samples, high expression of SLC34A2 was associated with large tumor size, advanced T status and poor patients' survival. The depletion of SLC34A2 in BC suppressed cellular viability, colony formation and anchorage-independent growth in vitro, and inhibited xenograft tumor growth in vivo, whereas overexpression of SLC34A2 had the converse effect. Simultaneously, downregulation of SLC34A2 decreased the transcriptional activity and protein expression level of c-Myc in BC cells, whereas restoration of c-Myc expression could compromise the anti-proliferation effect of SLC34A2 depletion. Furthermore, miR-214 was proved as a negative regulator of SLC34A2. Our present study illustrated that SLC34A2 has an important role in promoting proliferation and tumorigenicity of BC, and may represent a novel therapeutic target for this disease. PMID:28151475

Tethered balloon-based black carbon profiles within the lower troposphere of Shanghai in the 2013 East China smog

NASA Astrophysics Data System (ADS)

Li, Juan; Fu, Qingyan; Huo, Juntao; Wang, Dongfang; Yang, Wen; Bian, Qinggen; Duan, Yusen; Zhang, Yihua; Pan, Jun; Lin, Yanfen; Huang, Kan; Bai, Zhipeng; Wang, Sheng-Hsiang; Fu, Joshua S.; Louie, Peter K. K.

2015-12-01

A Tethered balloon-based field campaign was launched for the vertical observation of air pollutants within the lower troposphere of 1000 m for the first time over a Chinese megacity, Shanghai in December of 2013. A custom-designed instrumentation platform for tethered balloon observation and ground-based observation synchronously operated for the measurement of same meteorological parameters and typical air pollutants. One episodic event (December 13) was selected with specific focus on particulate black carbon, a short-lived climate forcer with strong warming effect. Diurnal variation of the mixing layer height showed very shallow boundary of less than 300 m in early morning and night due to nocturnal inversion while extended boundary of more than 1000 m from noon to afternoon. Wind profiles showed relatively stagnant synoptic condition in the morning, frequent shifts between upward and downward motion at noon and in the afternoon, and dominant downward motion with sea breeze in the evening. Characteristics of black carbon vertical profiles during four different periods of a day were analyzed and compared. In the morning, surface BC concentration averaged as high as 20 μg/m3 due to intense traffic emissions from the morning rush hours and unfavorable meteorological conditions. A strong gradient of BC concentrations with altitude was observed from the ground to the top of boundary layer at around 250-370 m. BC gradients turned much smaller above the boundary layer. BC profiles measured during noon and afternoon were the least dependent on heights. The largely extended boundary layer with strong vertical convection was responsible for a well mixing of BC particles in the whole measured column. BC profiles were similar between the early-evening and late-evening phases. The lower troposphere was divided into two stratified air layers with contrasted BC vertical distributions. Profiles at night showed strong gradients from the relatively high surface concentrations to low concentrations near the top of the boundary layer around 200 m. Above the boundary layer, BC increased with altitudes and reached a maximum at the top of 1000 m. Prevailing sea breeze within the boundary layer was mainly responsible for the quick cleanup of BC in the lower altitudes. In contrast, continental outflow via regional transport was the major cause of the enhanced BC aloft. This study provides a first insight of the black carbon vertical profiles over Eastern China, which will have significant implications for narrowing the gaps between the source emissions and observations as well as improving estimations of BC radiative forcing and regional climate.

Enhancing Photon Utilization Efficiency for Astaxanthin Production from Haematococcus lacustris Using a Split-Column Photobioreactor.

PubMed

Kim, Z-Hun; Park, Hanwool; Lee, Ho-Sang; Lee, Choul-Gyun

2016-07-28

A split-column photobioreactor (SC-PBR), consisting of two bubble columns with different sizes, was developed to enhance the photon utilization efficiency in an astaxanthin production process from Haematococcus lacustris. Among the two columns, only the smaller column of SC-PBR was illuminated. Astaxanthin productivities and photon efficiencies of the SC-PBRs were compared with a standard bubble-column PBR (BC-PBR). Astaxanthin productivity of SC-PBR was improved by 28%, and the photon utilization efficiencies were 28-366% higher than the original BC-PBR. The results clearly show that the effective light regime of SC-PBR could enhance the production of astaxanthin.

Seasonal variation in the spatial distribution of aerosol black carbon over Bay of Bengal: A synthesis of multi-campaign measurements

NASA Astrophysics Data System (ADS)

Kompalli, Sobhan Kumar; Suresh Babu, S.; Krishna Moorthy, K.; Nair, Vijayakumar S.; Gogoi, Mukunda M.; Chaubey, Jai Prakash

2013-01-01

Synthesizing data from several cruise experiments over the Bay of Bengal (BoB), the seasonal characterization of aerosol black carbon (BC) mass concentration was made. The study indicated that the BC mass concentration (MBC) showed significant seasonal variation over the oceanic region with MBC being the highest during the winter season (˜2407 ± 1756 ng m-3) and lowest in summer monsoon (˜765 ± 235 ng m-3). The seasonal changes in the BC mass concentration were more prominent over the northern BoB (having an annual amplitude of ˜4) compared to southern BoB (amplitude ˜ 2). Significant spatial gradients in MBC, latitudinal as well as longitudinal, existed in all the seasons. Latitudinal gradients, despite being consistently increasing northwards, were found to be sharper during winter and weakest during summer monsoon with e-fold scaling distances of ˜7.7° and ˜15.6° during winter and summer monsoon seasons respectively. Longitudinally, BC concentrations tend to increase toward east during winter and premonsoon seasons, but an opposite trend was seen in monsoon season highlighting the seasonally changing source impacts on BC loading over BoB. Examination of the results in light of possible role of transport from adjoining landmasses, using airmass back trajectory cluster analysis, also supported spatially and temporally varying source influence on oceanic region.

Additional Nodal Disease Prediction in Breast Cancer with Sentinel Lymph Node Metastasis Based on Clinicopathological Features.

PubMed

Orsaria, Paolo; Caredda, Emanuele; Genova, Federica; Materazzo, Marco; Capuano, Ilaria; Vanni, Gianluca; Granai, Alessandra Vittoria; DE Majo, Adriano; Portarena, Ilaria; Sileri, Pierpaolo; Petrella, Giuseppe; Palombi, Leonardo; Buonomo, Oreste Claudio

2018-04-01

The standard-of-care in breast cancer (BC) with positive sentinel lymph node (SLN) metastasis includes complete axillary lymph node dissection (ALND); however, almost half of such cases have no further tumor burden. This study aimed to assess the clinicopathological factors that predict non-SLN metastasis to define subgroups of SLN-positive patients in whom the axilla may be staged by SLN biopsy alone, while avoiding unnecessary overtreatment. The records of 191 patients with histologically-proven primary BC who underwent a positive (SLN) biopsy between 2005 and 2017 were reviewed. Patients with at least one tumor-involved SLN who underwent completion ALND were enrolled. Demographic and clinicopathological characteristics, including age, primary tumor size and histological grade, lymphovascular invasion, ratio of positive SLNs to the harvested SLNs, SLN metastasis size, and molecular subtype classification according to immunohistochemical biomarker status [estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)], were evaluated. Data were collected retrospectively and analyzed using the Mann-Whitney and Chi-square tests (statistical significance: p<0.05). The incidence of non-SLN metastasis associated with positive SLN was 48.6% (93/191). The risk of additional nodal spread correlated with high sentinel nodal ratio >0.67 [odds ratio (OR)=2.55, p=0.032], luminal BC subtype (OR=2.67, p=0.06), HER2 overexpression (OR=0.4, p=0.016), and ER + PR - HER2 - profile (OR=2.95, p=0.027). There was a tendency (statistically insignificant; p>0.05) toward higher incidence of non SLN metastasis with increasing age and histological grade, which could be attributed to the small sample size. According to this study, sentinel nodal ratio and BC subtypes as per ER, PR, and HER2 status significantly predicted the likelihood of additional lymphatic involvement. Validation of these parameters in prospective studies is indicated, and may help individualize treatment modalities. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

On the spatial distribution and evolution of ultrafine particles in Barcelona

NASA Astrophysics Data System (ADS)

Dall'Osto, M.; Querol, X.; Alastuey, A.; O'Dowd, C.; Harrison, R. M.; Wenger, J.; Gómez-Moreno, F. J.

2013-01-01

Sources and evolution of ultrafine particles were investigated both horizontally and vertically in the large urban agglomerate of Barcelona, Spain. Within the SAPUSS project (Solving Aerosol Problems by Using Synergistic Strategies), a large number of instruments was deployed simultaneously at different monitoring sites (road, two urban background, regional background, urban tower 150 m a.s.l., urban background tower site 80 m a.s.l.) during a 4 week period in September-October 2010. Particle number concentrations (N>5 nm) are highly correlated with black carbon (BC) at all sites only under strong vehicular traffic influences. By contrast, under cleaner atmospheric conditions (low condensation sink, CS) such correlation diverges towards much higher N/BC ratios at all sites, indicating additional sources of particles including secondary production of freshly nucleated particles. Size-resolved aerosol distributions (N10-500) as well as particle number concentrations (N>5 nm) allow us to identify three types of nucleation and growth events: (1) a regional type event originating in the whole study region and impacting almost simultaneously the urban city of Barcelona and the surrounding urban background area; (2) a regional type event impacting only the regional background area but not the urban agglomerate; (3) an urban type event which originates only within the city centre but whose growth continues while transported away from the city to the regional background. Furthermore, during these clean air days, higher N are found at tower level than at ground level only in the city centre whereas such a difference is not so pronounced at the remote urban background tower. In other words, this study suggests that the column of air above the city ground level possesses the optimal combination between low CS and high vapour source, hence enhancing the concentrations of freshly nucleated particles. By contrast, within stagnant polluted atmospheric conditions, higher N and BC concentrations are always measured at ground level relative to tower level at all sites. Our study suggests that the city centre of Barcelona is a source of non-volatile traffic primary particles (29-39% of N>5 nm), but other sources, including secondary freshly nucleated particles contribute up to 61-71% of particle number (N>5 nm) at all sites. We suggest that organic compounds evaporating from freshly emitted traffic particles are a possible candidate for new particle formation within the city and urban plume.

Identifying injection drug use and estimating population size of people who inject drugs using healthcare administrative datasets.

PubMed

Janjua, Naveed Zafar; Islam, Nazrul; Kuo, Margot; Yu, Amanda; Wong, Stanley; Butt, Zahid A; Gilbert, Mark; Buxton, Jane; Chapinal, Nuria; Samji, Hasina; Chong, Mei; Alvarez, Maria; Wong, Jason; Tyndall, Mark W; Krajden, Mel

2018-05-01

Large linked healthcare administrative datasets could be used to monitor programs providing prevention and treatment services to people who inject drugs (PWID). However, diagnostic codes in administrative datasets do not differentiate non-injection from injection drug use (IDU). We validated algorithms based on diagnostic codes and prescription records representing IDU in administrative datasets against interview-based IDU data. The British Columbia Hepatitis Testers Cohort (BC-HTC) includes ∼1.7 million individuals tested for HCV/HIV or reported HBV/HCV/HIV/tuberculosis cases in BC from 1990 to 2015, linked to administrative datasets including physician visit, hospitalization and prescription drug records. IDU, assessed through interviews as part of enhanced surveillance at the time of HIV or HCV/HBV diagnosis from a subset of cases included in the BC-HTC (n = 6559), was used as the gold standard. ICD-9/ICD-10 codes for IDU and injecting-related infections (IRI) were grouped with records of opioid substitution therapy (OST) into multiple IDU algorithms in administrative datasets. We assessed the performance of IDU algorithms through calculation of sensitivity, specificity, positive predictive, and negative predictive values. Sensitivity was highest (90-94%), and specificity was lowest (42-73%) for algorithms based either on IDU or IRI and drug misuse codes. Algorithms requiring both drug misuse and IRI had lower sensitivity (57-60%) and higher specificity (90-92%). An optimal sensitivity and specificity combination was found with two medical visits or a single hospitalization for injectable drugs with (83%/82%) and without OST (78%/83%), respectively. Based on algorithms that included two medical visits, a single hospitalization or OST records, there were 41,358 (1.2% of 11-65 years individuals in BC) recent PWID in BC based on health encounters during 3- year period (2013-2015). Algorithms for identifying PWID using diagnostic codes in linked administrative data could be used for tracking the progress of programing aimed at PWID. With population-based datasets, this tool can be used to inform much needed estimates of PWID population size. Copyright © 2018 Elsevier B.V. All rights reserved.

The short-term safety of adjuvant paclitaxel plus trastuzumab - A single centre experience.

PubMed

Ates, Ozturk; Sunar, Veli; Aslan, Alma; Karatas, Fatih; Sahin, Suleyman; Altundag, Kadri

2017-01-01

HER2-amplified breast cancer (BC) has a poor prognosis. The combination of trastuzumab with chemotherapy in the adjuvant setting decreases recurrence and improves overall survival in HER2-positive BC. However, the role of adjuvant treatment in patients with HER2-amplified small BC without lymph node involvement is still under debate. The purpose of this study was to investigate the safety of adjuvant paclitaxel and trastuzumab (APT) in this group of patients. A total of 87 operated early BC patients without lymph node involvement (N0) were treated with APT for 12 weeks followed by trastuzumab alone for a total of 9 months. Clinicopathological features and adverse events were analyzed. The median patient age was 50 years (range 28- 82), and 51% of them were postmenopausal. The median tumor diameter was 2.4 cm (range 0.5-6), with 51% of the patients having tumor size between 2 and 3 cm. Eighty-one percent of patients had invasive ductal carcinoma (IDC), and 64% had grade 3 tumors. Adjuvant hormone therapy and adjuvant radiotherapy were administered to 65 and 54% of patients, respectively. At a median follow up of 13 months (range 6-38), one patient (1.1%, 95% CI 0-3.4) experienced an asymptomatic decrease in left ventricular ejection fraction (LVEF) and 3 patients (3.4%, 95% CI 0-6.9) experienced grade 3 neuropathy. APT appears to be a safe combination in early-stage, HER2-amplified and node-negative BC.

Effects of the Wegener-Bergeron-Findeisen process on global black carbon distribution

NASA Astrophysics Data System (ADS)

Qi, Ling; Li, Qinbin; He, Cenlin; Wang, Xin; Huang, Jianping

2017-06-01

We systematically investigate the effects of Wegener-Bergeron-Findeisen process (hereafter WBF) on black carbon (BC) scavenging efficiency, surface BCair, deposition flux, concentration in snow (BCsnow, ng g-1), and washout ratio using a global 3-D chemical transport model (GEOS-Chem). We differentiate riming- versus WBF-dominated in-cloud scavenging based on liquid water content (LWC) and temperature. Specifically, we implement an implied WBF parameterization using either temperature or ice mass fraction (IMF) in mixed-phase clouds based on field measurements. We find that at Jungfraujoch, Switzerland, and Abisko, Sweden, where WBF dominates in-cloud scavenging, including the WBF effect strongly reduces the discrepancies of simulated BC scavenging efficiency and washout ratio against observations (from a factor of 3 to 10 % and from a factor of 4-5 to a factor of 2). However, at Zeppelin, Norway, where riming dominates, simulation of BC scavenging efficiency, BCair, and washout ratio become worse (relative to observations) when WBF is included. There is thus an urgent need for extensive observations to distinguish and characterize riming- versus WBF-dominated aerosol scavenging in mixed-phase clouds and the associated BC scavenging efficiency. Our model results show that including the WBF effect lowers global BC scavenging efficiency, with a higher reduction at higher latitudes (8 % in the tropics and up to 76 % in the Arctic). The resulting annual mean BCair increases by up to 156 % at high altitudes and at northern high latitudes because of lower temperature and higher IMF. Overall, WBF halves the model-observation discrepancy (from -65 to -30 %) of BCair across North America, Europe, China and the Arctic. Globally WBF increases BC burden from 0.22 to 0.29-0.35 mg m-2 yr-1, which partially explains the gap between observed and previous model-simulated BC burdens over land. In addition, WBF significantly increases BC lifetime from 5.7 to ˜ 8 days. Additionally, WBF results in a significant redistribution of BC deposition in source and remote regions. Specifically, it lowers BC wet deposition (by 37-63 % at northern mid-latitudes and by 21-29 % in the Arctic), while it increases dry deposition (by 3-16 % at mid-latitudes and by 81-159 % in the Arctic). The resulting total BC deposition is lower at mid-latitudes (by 12-34 %) but higher in the Arctic (by 2-29 %). We find that WBF decreases BCsnow at mid-latitudes (by ˜ 15 %) but increases it in the Arctic (by 26 %) while improving model comparisons with observations. In addition, WBF dramatically reduces the model-observation discrepancy of washout ratios in winter (from a factor of 16 to 4). The remaining discrepancies in BCair, BCsnow and BC washout ratios suggest that in-cloud removal in mixed-phased clouds is likely still excessive over land.

Magnetic sorbents added to soil slurries lower Cr aqueous concentration

NASA Astrophysics Data System (ADS)

Aravantinos, Konstantinos; Isari, Ekavi; Karapanagioti, Hrissi K.; Manariotis, Ioannis D.; Werner, David

2016-04-01

Activated carbon (AC) acts as a strong binding agent that lowers the pollutant concentration and, thus its toxicity. Another promising sorbent material in environmental applications is biochar (BC) which is obtained from the incomplete combustion of carbon-rich biomass under oxygen-limited conditions. Both of these materials could be used as soil or sediment amendments that would lower the toxicity in the aqueous phase. A draw back of this technique is that although the pollutant will remain non- bioavailable for many years being sorbed into these sorbents, it actually stays into the system. The objective of this study was (a) to synthesize a magnetic powdered activated carbon (AC/Fe) and magnetic powdered biochar (BC/Fe) produced from a commercial AC sample and BC, respectively and (b) to evaluate the potential use of AC/Fe and BC/Fe to lower Cr concentration that desorb from two soils in their soil slurries. The two soil samples originate from the vicinity of a local metal shop. The BC was produced from olive pomace. The surface area, the pore volume, and the average pore size of each sorbent were determined using gas (N2) adsorption-desorption cycles and the Brunauer, Emmett, and Teller (BET) equation. Isotherms with 30 adsorption and 20 desorption points were conducted at liquid nitrogen temperature (77K). Open surface area and micropore volume were determined using t-plot method and Harkins & Jura equation. For both AC/Fe, surface area measurements resulted in 66% those of corresponding AC. For BC/Fe, the surface area was 82% that of BC. Our previous studies have shown that both AC/Fe and BC/Fe are effective sorbents for mercury in aqueous solutions but with lower sorption capacity compared to the initial materials (50-75% lower). Batch experiments with all sorbent samples and each soil were conducted at room temperature (25oC) in order to compare the sorption properties of the materials. The soil slurries demonstrated low Cr concentrations (10.9 and 14.6 μg/L, respectively). One month after the addition of amendments AC, AC/Fe, and BC/Fe, Cr concentration in the slurry was lower than the detection limit which was 0.5 μg/L (except of one of the soils with the AC that was 2.1 μg/L). The slurries with BC demonstrated Cr concentrations equal to 4.2 and 7.1 μg/L, respectively. All these properties point to promising materials that can effectively be used for in-situ environmental remediation and also be recovered.

Radiocarbon-insights into temporal variations in the sources and concentrations of carbonaceous aerosols in the Los Angeles and Salt Lake City Metropolitan Areas

NASA Astrophysics Data System (ADS)

Czimczik, Claudia; Mouteva, Gergana; Simon, Fahrni; Guaciara, Santos; James, Randerson

2014-05-01

Increased fossil fuel consumption and biomass burning are contributing to significantly larger emissions of black carbon (BC) aerosols to the atmosphere. Together with organic carbon (OC), BC is a major constituent of fine particulate matter in urban air, contributes to haze and has been linked to a broad array of adverse health effects. Black carbon's high light absorption capacity and role in key (in-)direct climate feedbacks also lead to a range of impacts in the Earth system (e.g. warming, accelerated snow melt, changes in cloud formation). Recent work suggests that regulating BC emissions can play an important role in improving regional air quality and reducing future climate warming. However, BC's atmospheric transport pathways, lifetime and magnitudes of emissions by sector and region, particularly emissions from large urban centers, remain poorly constrained by measurements. Contributions of fossil and modern sources to the carbonaceous aerosol pool (corresponding mainly to traffic/industrial and biomass-burning/biogenic sources, respectively) can be quantified unambiguously by measuring the aerosol radiocarbon (14C) content. However, accurate 14C-based source apportionment requires the physical isolation of BC and OC, and minimal sample contamination with extraneous carbon or from OC charring. Compound class-specific 14C analysis of BC remains challenging due to very small sample sizes (5-15 ug C). Therefore, most studies to date have only analyzed the 14C content of the total organic carbonaceous aerosol fraction. Here, we present time-series 14C data of BC and OC from the Los Angeles (LA) metropolitan area in California - one of two megacities in the United States - and from Salt Lake City (SLC), UT. In the LA area, we analyzed 48h-PM10 samples near the LA port throughout 2007 and 2008 (with the exception of summer). We also collected monthly-PM2.5 samples at the University of California - Irvine, with shorter sampling periods during regional wildfire activity and Santa Ana winds from March to August 2013. In SLC, we seasonally collected 48h-PM2.5 samples from October 2012 to February 2014. We isolated and quantified BC and OC using a thermo-optical analyzer (RT 3080, Sunset Laboratory, Tigard, OR, USA) with the Swiss_4S protocol, and measured the 14C content of BC and OC with accelerator mass spectrometry at UCI's KCCAMS facility. We also measured the concentration and stable isotope composition of total (organic) carbon and nitrogen on the aerosol filters with EA-IRMS (Carlo Erba coupled to Finnigan DeltaPlus). Preliminary results suggest that in LA, PM10-BC concentrations are on the order of 2-8 ug C/m3. Black carbon is 14C-depleted (FM 0.04-0.21) - indicating that fossil sources dominate emissions. In comparison, OC concentrations were higher (12-17 ugC/m3) and more enriched in 14C (FM 0.54-0.83). In SLC, PM2.5-BC concentrations range from <1 to 3 ug C/m3, with the highest concentrations observed during wintertime inversions. The BC fraction is strongly 14C -depleted (FM 0.06 to 0.12) - indicating a dominance of fossil BC emissions throughout the year. Together, our measurements contribute to a comprehensive quantification of temporal and spatial variations in urban BC, a key uncertainty in constraining BC sources and transport in western North America.

Tests of a solution-grown stilbene scintillator in mono-energetic neutron beams of 565 keV and 5 MeV

NASA Astrophysics Data System (ADS)

Dioni, Luca; Gressier, Vincent; Nardin, Gaëlle; Jacqmin, Robert; Stout, Brian; Sumini, Marco

2018-02-01

The results of measurements performed with a solution-grown stilbene scintillator placed in reference mono-energetic neutron fields are presented. The ∅ 25 mm organic scintillator was positioned in 5 MeV and 565 keV neutron fields delivered by the AIFIRA facility at CENBG. The goal of the experiment was to assess the performance of the solution-grown stilbene crystal (n- γ discrimination, response, anisotropy, sensitivity) relative to that of a BC501A liquid scintillator of larger size. Neutron pulse height spectra after gamma discrimination are compared. The results show that the stilbene crystal not only has a better discrimination capability than the BC501A (35% higher FoM) at 5 MeV, but is also able to separate neutrons from gamma-rays at 565 keV and below, a range where the BC501A is inoperative. This study also confirms the anisotropy of the crystal response, as already observed by other groups at different energies.

Anthropogenic iron oxide aerosols enhance atmospheric heating

PubMed Central

Moteki, Nobuhiro; Adachi, Kouji; Ohata, Sho; Yoshida, Atsushi; Harigaya, Tomoo; Koike, Makoto; Kondo, Yutaka

2017-01-01

Combustion-induced carbonaceous aerosols, particularly black carbon (BC) and brown carbon (BrC), have been largely considered as the only significant anthropogenic contributors to shortwave atmospheric heating. Natural iron oxide (FeOx) has been recognized as an important contributor, but the potential contribution of anthropogenic FeOx is unknown. In this study, we quantify the abundance of FeOx over East Asia through aircraft measurements using a modified single-particle soot photometer. The majority of airborne FeOx particles in the continental outflows are of anthropogenic origin in the form of aggregated magnetite nanoparticles. The shortwave absorbing powers (Pabs) attributable to FeOx and to BC are calculated on the basis of their size-resolved mass concentrations and the mean Pabs(FeOx)/Pabs(BC) ratio in the continental outflows is estimated to be at least 4–7%. We demonstrate that in addition to carbonaceous aerosols the aggregate of magnetite nanoparticles is a significant anthropogenic contributor to shortwave atmospheric heating. PMID:28508863

Effect of heteroscedasticity treatment in residual error models on model calibration and prediction uncertainty estimation

NASA Astrophysics Data System (ADS)

Sun, Ruochen; Yuan, Huiling; Liu, Xiaoli

2017-11-01

The heteroscedasticity treatment in residual error models directly impacts the model calibration and prediction uncertainty estimation. This study compares three methods to deal with the heteroscedasticity, including the explicit linear modeling (LM) method and nonlinear modeling (NL) method using hyperbolic tangent function, as well as the implicit Box-Cox transformation (BC). Then a combined approach (CA) combining the advantages of both LM and BC methods has been proposed. In conjunction with the first order autoregressive model and the skew exponential power (SEP) distribution, four residual error models are generated, namely LM-SEP, NL-SEP, BC-SEP and CA-SEP, and their corresponding likelihood functions are applied to the Variable Infiltration Capacity (VIC) hydrologic model over the Huaihe River basin, China. Results show that the LM-SEP yields the poorest streamflow predictions with the widest uncertainty band and unrealistic negative flows. The NL and BC methods can better deal with the heteroscedasticity and hence their corresponding predictive performances are improved, yet the negative flows cannot be avoided. The CA-SEP produces the most accurate predictions with the highest reliability and effectively avoids the negative flows, because the CA approach is capable of addressing the complicated heteroscedasticity over the study basin.

Integrated emission inventory and modeling to assess distribution of particulate matter mass and black carbon composition in Southeast Asia

NASA Astrophysics Data System (ADS)

Agustian Permadi, Didin; Oanh, Nguyen Thi Kim; Vautard, Robert

2018-02-01

This is part of a research study addressing the potential co-benefits associated with selected black carbon (BC) emission reduction measures on mitigation of air pollution and climate forcing in Southeast Asia (SEA). This paper presents details of emission inventory (EI) results and WRF-CHIMERE model performance evaluation. The SEA regional emissions for 2007 were updated with our EI results for Indonesia, Thailand, and Cambodia and used for the model input. WRF-CHIMERE-simulated 2007 PM10, PM2.5, and BC over the SEA domain (0.25° × 0.25°) and the results were evaluated against the available meteorology and air quality monitoring data in the domain. WRF hourly simulation results were evaluated using the observed data at eight international airport stations in five SEA countries and showed a satisfactory performance. WRF-CHIMERE results for PM10 and PM2.5 showed strong seasonal influence of biomass open burning while the BC distribution showed the influence of urban activities in big SEA cities. Daily average PM10 constructed from the hourly concentrations were obtained from the automatic monitoring stations in three large SEA cities, i.e., Bangkok, Kuala Lumpur, and Surabaya, for model evaluation. The daily observed PM2.5 and BC concentrations obtained from the Improving Air Quality in Asian Developing Countries (AIRPET) project for four cities (i.e., Bangkok, Hanoi, Bandung, and Manila) were also used for model evaluation. In addition, hourly BC concentrations were taken from the measurement results of the Asian Pacific Network (APN) project at a suburban site in Bangkok. The modeled PM10 and BC satisfactorily met all suggested statistical criteria for PM evaluation. The modeled PM2.5/PM10 ratios estimated for four AIRPET sites ranged between 0.47 and 0.59, lower than observed values of 0.6-0.83. Better agreement was found for BC/PM2.5 ratios with the modeled values of 0.05-0.33 as compared to the observation values of 0.05-0.28. AODEM (extended aerosol optical depth module) was used to calculate the total columnar aerosol optical depth (AOD) and BC AOD up to the top of the domain at 500 hPa (˜ 5500 m), which did not include the free-tropospheric long-range transport of the pollution. The model AOD results calculated using the internal mixing assumption were evaluated against the observed AOD by both AERONET and MODIS satellite in 10 countries in the domain. Our model results showed that the BC AOD contributed 7.5-12 % of the total AOD, which was in the same range reported by other studies for places with intensive emissions. The results of this paper are used to calculate the regional aerosol direct radiative forcing under different emission reduction scenarios to explore potential co-benefits for air quality improvement, reduction in the number of premature deaths, and climate forcing mitigation in SEA in 2030 (Permadi et al., 2017a).

Contributions of dynamic environmental signals during life-cycle transitions to early life-history traits in lodgepole pine (Pinus contorta Dougl.)

NASA Astrophysics Data System (ADS)

Liu, Yang; Wang, Tongli; El-Kassaby, Yousry A.

2016-05-01

Environmental signals are important triggers in the life-cycle transitions and play a crucial role in the life-history evolution. Yet very little is known about the leading ecological factors contributing to the variations of life-history traits in perennial plants. This paper explores both the causes and consequences for the evolution of life-history traits (i.e., seed dormancy and size) in lodgepole pine (Pinus contorta Dougl.) across British Columbia (B.C.), Canada. We selected 83 logepole pine populations covering 22 ecosystem zones of B.C. and through their geographic coordinate, 197 climatic variables were generated accordingly for the reference (1961-1990) and future (2041-2070) periods. We found that dynamic climatic variables rather than constant geographic variables are the true environmental driving forces in seed dormancy and size variations and thus provide reliable predictors in response to global climate change. Evapotranspiration and precipitation in the plant-to-seed chronology are the most critical climate variables for seed dormancy and size variations, respectively. Hence, we predicted that levels of seed dormancy in lodgepole pine would increase across large tracts of B.C. in 2050s. Winter-chilling is able to increase the magnitude of life-history plasticity and lower the bet-hedge strategy in the seed-to-plant transition; however, winter-chilling is likely to be insufficient in the north of 49° N in 2050s, which may delay germination while unfavorable conditions during dry summers may result in adverse consequences in the survival of seedlings owing to extended germination span. These findings provide useful information to studies related to assessments of seed transfer and tree adaptation.

Effective techniques in healthy eating and physical activity interventions: a meta-regression.

PubMed

Michie, Susan; Abraham, Charles; Whittington, Craig; McAteer, John; Gupta, Sunjai

2009-11-01

Meta-analyses of behavior change (BC) interventions typically find large heterogeneity in effectiveness and small effects. This study aimed to assess the effectiveness of active BC interventions designed to promote physical activity and healthy eating and investigate whether theoretically specified BC techniques improve outcome. Interventions, evaluated in experimental or quasi-experimental studies, using behavioral and/or cognitive techniques to increase physical activity and healthy eating in adults, were systematically reviewed. Intervention content was reliably classified into 26 BC techniques and the effects of individual techniques, and of a theoretically derived combination of self-regulation techniques, were assessed using meta-regression. Valid outcomes of physical activity and healthy eating. The 122 evaluations (N = 44,747) produced an overall pooled effect size of 0.31 (95% confidence interval = 0.26 to 0.36, I(2) = 69%). The technique, "self-monitoring," explained the greatest amount of among-study heterogeneity (13%). Interventions that combined self-monitoring with at least one other technique derived from control theory were significantly more effective than the other interventions (0.42 vs. 0.26). Classifying interventions according to component techniques and theoretically derived technique combinations and conducting meta-regression enabled identification of effective components of interventions designed to increase physical activity and healthy eating. PsycINFO Database Record (c) 2009 APA, all rights reserved.

The influence of anthropometry and body composition on children's bone health: the childhood health, activity and motor performance school (the CHAMPS) study, Denmark.

PubMed

Heidemann, Malene; Holst, René; Schou, Anders J; Klakk, Heidi; Husby, Steffen; Wedderkopp, Niels; Mølgaard, Christian

2015-02-01

Overweight, physical inactivity and sedentary behaviour have become increasing problems during the past decade. Increased sedentary behaviour may change the body composition (BC) by increasing the fat mass relative to the lean mass (LM). These changes may influence bone health to describe how anthropometry and BC predict the development of the bone accruement. The longitudinal study is a part of The CHAMPS study-DK. Children were DXA scanned at baseline and at 2-year follow-up. BC (LM, BF %) and BMC, BMD and BA were measured. The relationship between bone traits, anthropometry and BC was analysed by multilevel regression analyses. Of the invited children, 742/800 (93%) accepted to participate. Of these, 682/742 (92%) participated at follow-up. Mean (range) of age at baseline was 9.5 years (7.7-12.1). Height, BMI, LM and BF % predicted bone mineral accrual and bone size positively and independently. Height and BMI are both positive predictors of bone accruement. LM is a more precise predictor of bone traits than BF % in both genders. The effects of height and BMI and LM on bone accruement are nearly identical in the two genders, while changes in BF % have different but positive effects on bone accretion in both boys and girls.

Practical considerations, column studies and natural organic material competition for fluoride removal with bone char and aluminum amended materials in the Main Ethiopian Rift Valley.

PubMed

Brunson, Laura R; Sabatini, David A

2014-08-01

The fluoride removal capacities of three materials, bone char (BC), aluminum oxide coated bone char (ACBC) and aluminum oxide impregnated wood char (AIWC), along with activated alumina (AA) as a baseline material, were investigated in batch and column studies, including comparison between synthetic and natural groundwater. Results suggest that in all cases the laboratory column results exhibited higher fluoride removal efficiency than the field studies conducted in the Ethiopian Rift Valley. Further studies indicate that the reduced effectiveness in the field was likely due to a combination of the high pH of groundwater (8.2) and the presence of competing ions (sulfate). Batch studies testing potential competition from natural organic material (NOM) showed no statistical evidence of NOM competition with BC and minor evidence of competition with ACBC and AIWC. To provide evidence for using Rapid Scale Small Column Test (RSSCT) principles for BC two different column volume and particle sizes were used. The results indicate that RSSCT scaling equations, developed for activated carbon, are applicable for BC removal of fluoride. These results thus provide valuable insights for translating laboratory results of novel sorbents for mitigating fluoride tainted groundwater in the field. Copyright © 2013 Elsevier B.V. All rights reserved.

Geographic Distribution and Temporal Trends of HIV-1 Subtypes through Heterosexual Transmission in China: A Systematic Review and Meta-Analysis

PubMed Central

Xiao, Peipei; Li, Jianjun; Fu, Gengfeng; Zhou, Ying; Huan, Xiping; Yang, Haitao

2017-01-01

Background: Heterosexual transmission (HST) has become the current predominant transmission pathways of the HIV-1 epidemic in China. The aim of this study was to explore the geographic and dynamic change of HIV-1 subtypes through HST in China from published studies. Methods: Several electronic databases were searched to identify the studies, and the overall prevalence of HIV-1 subtypes was estimated by a meta-analysis method. Subgroup analysis was conducted by study region and time period. Publication bias was evaluated using Egger’s test. The χ2 test was used to evaluate the proportion differences among subgroups. Sensitivity analysis was carried out to assess the stability of the overall prevalence estimates. Results: 42 studies were included in our final analysis. The overall prevalence of CRF01_AE was 46.34% (95% CI: 40.56–52.17%), CRF07_BC was 19.16% (95% CI: 15.02–23.66%), B/B’ was 13.25% (95% CI: 9.68–17.25%), CRF08_BC was 10.61% (95% CI: 7.08–14.70%), and C was 4.29% (95% CI: 1.85–7.48%). In subgroup analysis, the prevalence of CRF01_AE and CRF07_BC increased, while the prevalence of B/B’ decreased over time, whereby the prevalence of CRF07_BC and CRF08_BC have exceeded that of B/B’ since 2010. A significant higher prevalence of CRF01_AE was found in the South provinces, CRF07_BC in East provinces, CRF08_BC and C in Southwest provinces, and B/B’ in North provinces. Conclusions: The HIV-1 prevalent strains have evolved into complicated and diverse subtypes, and the proportion of HIV-1 subtypes through HST has changed constantly in different regions and periods in China. This highlights the urgent need to vigorously strengthen the prevention and control of the HIV-1 epidemic. PMID:28737729

Modifications in bacterial groups and short chain fatty acid production in the gut of healthy adult rats after long-term consumption of dietary Maillard reaction products.

PubMed

Delgado-Andrade, Cristina; Pastoriza de la Cueva, Silvia; Peinado, M Jesús; Rufián-Henares, José Ángel; Navarro, M Pilar; Rubio, Luis A

2017-10-01

Bread crust (BC) is one of the major sources of Maillard reaction products (MRPs) in the Western diet. This work was designed to analyze the impact of diets containing important levels of MRPs from BC on intestinal bacterial growth and short chain fatty acids (SCFAs) production in adult rats. Additionally, the pools of compounds excreted in feces attending to their molecular weights were analyzed. Rats were fed for 88days a control diet or diets containing BC or its soluble high molecular weight (HMW), soluble low molecular weight (LMW) or insoluble fractions, respectively. Intestinal (cecum) microbiota composition was determined by qPCR analysis. Consumption of the BC diet lowered (P<0.05) Lactobacillus spp. and Bifidobacterium spp. log 10 counts (8 and 14%, respectively), an effect for which soluble LMW and HMW fractions of BC seemed to be responsible. In these same animals, Escherichia/Shigella counts increased by around 45% (P<0.05), a fact which correlated with a higher production of formic acid in feces (r=0.8197, P=0.0458), and likely caused by the combined consumption of all MRPs contained in the BC. A significant 5-fold increment (P<0.05) was detected in the fecal proportion of propionic acid in the BC group, one of the products that have largely been associated with anti-inflammatory actions. Regarding the distribution of MRPs in feces, only the LMW fed group exhibited a predominance of those ranging between 90,000-1000Da, whereas the rest of the groups presented higher amounts of products above 90,000Da. It is concluded that dietary Maillard reaction products are in vivo fermented by the gut microbiota, thereby changing both the pattern of SCFAs production and the microbiota composition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Common breast cancer susceptibility alleles and the risk of breast cancer for BRCA1 and BRCA2 mutation carriers: implications for risk prediction

PubMed Central

Antoniou, Antonis C; Beesley, Jonathan; McGuffog, Lesley; Sinilnikova, Olga M.; Healey, Sue; Neuhausen, Susan L.; Ding, Yuan Chun; Rebbeck, Timothy R.; Weitzel, Jeffrey N.; Lynch, Henry T.; Isaacs, Claudine; Ganz, Patricia A.; Tomlinson, Gail; Olopade, Olufunmilayo I.; Couch, Fergus J.; Wang, Xianshu; Lindor, Noralane M.; Pankratz, Vernon S.; Radice, Paolo; Manoukian, Siranoush; Peissel, Bernard; Zaffaroni, Daniela; Barile, Monica; Viel, Alessandra; Allavena, Anna; Dall’Olio, Valentina; Peterlongo, Paolo; Szabo, Csilla I.; Zikan, Michal; Claes, Kathleen; Poppe, Bruce; Foretova, Lenka; Mai, Phuong L.; Greene, Mark H.; Rennert, Gad; Lejbkowicz, Flavio; Glendon, Gord; Ozcelik, Hilmi; Andrulis, Irene L.; Thomassen, Mads; Gerdes, Anne-Marie; Sunde, Lone; Cruger, Dorthe; Jensen, Uffe Birk; Caligo, Maria; Friedman, Eitan; Kaufman, Bella; Laitman, Yael; Milgrom, Roni; Dubrovsky, Maya; Cohen, Shimrit; Borg, Ake; Jernström, Helena; Lindblom, Annika; Rantala, Johanna; Stenmark-Askmalm, Marie; Melin, Beatrice; Nathanson, Kate; Domchek, Susan; Jakubowska, Ania; Lubinski, Jan; Huzarski, Tomasz; Osorio, Ana; Lasa, Adriana; Durán, Mercedes; Tejada, Maria-Isabel; Godino, Javier; Benitez, Javier; Hamann, Ute; Kriege, Mieke; Hoogerbrugge, Nicoline; van der Luijt, Rob B; van Asperen, Christi J; Devilee, Peter; Meijers-Heijboer, E.J.; Blok, Marinus J; Aalfs, Cora M.; Hogervorst, Frans; Rookus, Matti; Cook, Margaret; Oliver, Clare; Frost, Debra; Conroy, Don; Evans, D. Gareth; Lalloo, Fiona; Pichert, Gabriella; Davidson, Rosemarie; Cole, Trevor; Cook, Jackie; Paterson, Joan; Hodgson, Shirley; Morrison, Patrick J.; Porteous, Mary E.; Walker, Lisa; Kennedy, M. John; Dorkins, Huw; Peock, Susan; Godwin, Andrew K.; Stoppa-Lyonnet, Dominique; de Pauw, Antoine; Mazoyer, Sylvie; Bonadona, Valérie; Lasset, Christine; Dreyfus, Hélène; Leroux, Dominique; Hardouin, Agnès; Berthet, Pascaline; Faivre, Laurence; Loustalot, Catherine; Noguchi, Tetsuro; Sobol, Hagay; Rouleau, Etienne; Nogues, Catherine; Frénay, Marc; Vénat-Bouvet, Laurence; Hopper, John L.; Daly, Mary B.; Terry, Mary B.; John, Esther M.; Buys, Saundra S.; Yassin, Yosuf; Miron, Alex; Goldgar, David; Singer, Christian F.; Dressler, Anne Catharina; Gschwantler-Kaulich, Daphne; Pfeiler, Georg; Hansen, Thomas V. O.; Jønson, Lars; Agnarsson, Bjarni A.; Kirchhoff, Tomas; Offit, Kenneth; Devlin, Vincent; Dutra-Clarke, Ana; Piedmonte, Marion; Rodriguez, Gustavo C.; Wakeley, Katie; Boggess, John F.; Basil, Jack; Schwartz, Peter E.; Blank, Stephanie V.; Toland, Amanda Ewart; Montagna, Marco; Casella, Cinzia; Imyanitov, Evgeny; Tihomirova, Laima; Blanco, Ignacio; Lazaro, Conxi; Ramus, Susan J.; Sucheston, Lara; Karlan, Beth Y.; Gross, Jenny; Schmutzler, Rita; Wappenschmidt, Barbara; Engel, Christoph; Meindl, Alfons; Lochmann, Magdalena; Arnold, Norbert; Heidemann, Simone; Varon-Mateeva, Raymonda; Niederacher, Dieter; Sutter, Christian; Deissler, Helmut; Gadzicki, Dorothea; Preisler-Adams, Sabine; Kast, Karin; Schönbuchner, Ines; Caldes, Trinidad; de la Hoya, Miguel; Aittomäki, Kristiina; Nevanlinna, Heli; Simard, Jacques; Spurdle, Amanda B.; Holland, Helene; Chen, Xiaoqing; Platte, Radka; Chenevix-Trench, Georgia; Easton, Douglas F.

2010-01-01

The known breast cancer (BC) susceptibility polymorphisms in FGFR2, TNRC9/TOX3, MAP3K1,LSP1 and 2q35 confer increased risks of BC for BRCA1 or BRCA2 mutation carriers. We evaluated the associations of three additional SNPs, rs4973768 in SLC4A7/NEK10, rs6504950 in STXBP4/COX11 and rs10941679 at 5p12 and reanalyzed the previous associations using additional carriers in a sample of 12,525 BRCA1 and 7,409 BRCA2 carriers. Additionally, we investigated potential interactions between SNPs and assessed the implications for risk prediction. The minor alleles of rs4973768 and rs10941679 were associated with increased BC risk for BRCA2 carriers (per-allele Hazard Ratio (HR)=1.10, 95%CI:1.03-1.18, p=0.006 and HR=1.09, 95%CI:1.01-1.19, p=0.03, respectively). Neither SNP was associated with BC risk for BRCA1 carriers and rs6504950 was not associated with BC for either BRCA1 or BRCA2 carriers. Of the nine polymorphisms investigated, seven were associated with BC for BRCA2 carriers (FGFR2, TOX3, MAP3K1, LSP1, 2q35, SLC4A7, 5p12, p-values:7×10−11-0.03), but only TOX3 and 2q35 were associated with the risk for BRCA1 carriers (p=0.0049, 0.03 respectively). All risk associated polymorphisms appear to interact multiplicatively on BC risk for mutation carriers. Based on the joint genotype distribution of the seven risk associated SNPs in BRCA2 mutation carriers, the 5% of BRCA2 carriers at highest risk (i.e. between 95th and 100th percentiles) were predicted to have a probability between 80% and 96% of developing BC by age 80, compared with 42-50% for the 5% of carriers at lowest risk. Our findings indicated that these risk differences may be sufficient to influence the clinical management of mutation carriers. PMID:21118973

Properties of calcium silicate-monobasic calcium phosphate materials for endodontics containing tantalum pentoxide and zirconium oxide.

PubMed

Zamparini, Fausto; Siboni, Francesco; Prati, Carlo; Taddei, Paola; Gandolfi, Maria Giovanna

2018-05-08

The aim of the study was to evaluate chemical-physical properties and apatite-forming ability of three premixed calcium silicate materials containing monobasic calcium phosphate (CaH 4 P 2 O 8 ) bioceramic, tantalum pentoxide and zirconium oxide, recently marketed for endodontics (TotalFill BC-Sealer, BC-RRM-Paste, BC-RRM-Putty). Microchemical and micromorphological analyses, radiopacity, initial and final setting times, calcium release and alkalising activity were tested. The nucleation of calcium phosphates (CaPs) and/or apatite after 28 days ageing was evaluated by ESEM-EDX and micro-Raman spectroscopy. BC-Sealer and BC-RRM-Paste showed similar initial (23 h), prolonged final (52 h) setting times and good radiopacity (> 7 mm Al); BC-RRM-Putty showed fast initial (2 h) and final setting times (27 h) and excellent radiopacity (> 9 mm Al). All materials induced a marked alkalisation (pH 11-12) up to 28 days and showed the release of calcium ions throughout the entire test period (cumulative calcium release 641-806 ppm). After 28 days ageing, a well-distributed mineral layer was present on all samples surface; EDX demonstrated relevant calcium and phosphorous peaks. B-type carbonated apatite and calcite deposits were identified by micro-Raman spectroscopy on all the 28-day-aged samples; the deposit thickness was higher on BC-RRM-Paste and BC-RRM-Putty, in agreement with calcium release data. These materials met the required chemical and physical standards and released biologically relevant ions. The CaSi-CaH 4 P 2 O 8 system present in the materials provided Ca and OH ions release with marked abilities to nucleate a layer of B-type carbonated apatite favoured/accelerated by the bioceramic presence. The ability to nucleate apatite may lead many clinical advantages: In orthograde endodontics, it may improve the sealing ability by the deposition of CaPs at the material-root dentine interface, and in endodontic surgery, it could promote bone and periodontal tissue regeneration. As premixed materials, their application in endodontics may result easier in several complex endodontic situations (apicoectomy, root perforation, presence of wide/wet apices).

In-situ measurements of light-absorbing impurities in snow of glacier on Mt. Yulong and implications for radiative forcing estimates.

PubMed

Niu, Hewen; Kang, Shichang; Shi, Xiaofei; Paudyal, Rukumesh; He, Yuanqing; Li, Gang; Wang, Shijin; Pu, Tao; Shi, Xiaoyi

2017-03-01

The Tibetan Plateau (TP) or the third polar cryosphere borders geographical hotspots for discharges of black carbon (BC). BC and dust play important roles in climate system and Earth's energy budget, particularly after they are deposited on snow and glacial surfaces. BC and dust are two kinds of main light-absorbing impurities (LAIs) in snow and glaciers. Estimating concentrations and distribution of LAIs in snow and glacier ice in the TP is of great interest because this region is a global hotspot in geophysical research. Various snow samples, including surface aged-snow, superimposed ice and snow meltwater samples were collected from a typical temperate glacier on Mt. Yulong in the snow melt season in 2015. The samples were determined for BC, Organic Carbon (OC) concentrations using an improved thermal/optical reflectance (DRI Model 2001) method and gravimetric method for dust concentrations. Results indicated that the LAIs concentrations were highly elevation-dependent in the study area. Higher contents and probably greater deposition at relative lower elevations (generally <5000masl) of the glacier was observed. Temporal difference of LAIs contents demonstrated that LAIs in snow of glacier gradually increased as snow melting progressed. Evaluations of the relative absorption of BC and dust displayed that the impact of dust on snow albedo and radiative forcing (RF) is substantially larger than BC, particularly when dust contents are higher. This was verified by the absorption factor, which was <1.0. In addition, we found the BC-induced albedo reduction to be in the range of 2% to nearly 10% during the snow melting season, and the mean snow albedo reduction was 4.63%, hence for BC contents ranging from 281 to 894ngg -1 in snow of a typical temperate glacier on Mt. Yulong, the associated instantaneous RF will be 76.38-146.96Wm -2 . Further research is needed to partition LAIs induced glacial melt, modeling researches in combination with long-term in-situ observations of LAIs in glaciers is also urgent needed in the future work. Copyright © 2017 Elsevier B.V. All rights reserved.

Morphology of Dwarf Galaxies in Isolated Satellite Systems

NASA Astrophysics Data System (ADS)

Ann, Hong Bae

2017-08-01

The environmental dependence of the morphology of dwarf galaxies in isolated satellite systems is analyzed to understand the origin of the dwarf galaxy morphology using the visually classified morphological types of 5836 local galaxies with z ≲ 0.01. We consider six sub-types of dwarf galaxies, dS0, dE, dE_{bc}, dSph, dE_{blue}, and dI, of which the first four sub-types are considered as early-type and the last two as late-type. The environmental parameters we consider are the projected distance from the host galaxy (r_{p}), local and global background densities, and the host morphology. The spatial distributions of dwarf satellites of early-type galaxies are much different from those of dwarf satellites of late-type galaxies, suggesting the host morphology combined with r_{p} plays a decisive role on the morphology of the dwarf satellite galaxies. The local and global background densities play no significant role on the morphology of dwarfs in the satellite systems hosted by early-type galaxies. However, in the satellite system hosted by late-type galaxies, the global background densities of dE and dSph satellites are significantly different from those of dE_{bc}, dE_{blue}, and dI satellites. The blue-cored dwarf satellites (dE_{bc}) of early-type galaxies are likely to be located at r_{p} > 0.3 Mpc to keep their cold gas from the ram pressure stripping by the hot corona of early-type galaxies. The spatial distribution of dE_{bc} satellites of early-type galaxies and their global background densities suggest that their cold gas is intergalactic material accreted before they fall into the satellite systems.

Barriers to Rural Induced Abortion Services in Canada: Findings of the British Columbia Abortion Providers Survey (BCAPS)

PubMed Central

Norman, Wendy V.; Soon, Judith A.; Maughn, Nanamma; Dressler, Jennifer

2013-01-01

Background Rural induced abortion service has declined in Canada. Factors influencing abortion provision by rural physicians are unknown. This study assessed distribution, practice, and experiences among rural compared to urban abortion providers in the Canadian province of British Columbia (BC). Methods We used mixed methods to assess physicians on the BC registry of abortion providers. In 2011 we distributed a previously-published questionnaire and conducted semi-structured interviews. Results Surveys were returned by 39/46 (85%) of BC abortion providers. Half were family physicians, within both rural and urban cohorts. One-quarter (17/67) of rural hospitals offer abortion service. Medical abortions comprised 14.7% of total reported abortions. The three largest urban areas reported 90% of all abortions, although only 57% of reproductive age women reside in the associated health authority regions. Each rural physician provided on average 76 (SD 52) abortions annually, including 35 (SD 30) medical abortions. Rural physicians provided surgical abortions in operating rooms, often using general anaesthesia, while urban physicians provided the same services primarily in ambulatory settings using local anaesthesia. Rural providers reported health system barriers, particularly relating to operating room logistics. Urban providers reported occasional anonymous harassment and violence. Conclusions Medical abortions represented 15% of all BC abortions, a larger proportion than previously reported (under 4%) for Canada. Rural physicians describe addressable barriers to service provision that may explain the declining accessibility of rural abortion services. Moving rural surgical abortions out of operating rooms and into local ambulatory care settings has the potential to improve care and costs, while reducing logistical challenges facing rural physicians. PMID:23840578

Spatial distribution of aerosol black carbon over India during pre-monsoon season

NASA Astrophysics Data System (ADS)

Beegum, S. Naseema; Moorthy, K. Krishna; Babu, S. Suresh; Satheesh, S. K.; Vinoj, V.; Badarinath, K. V. S.; Safai, P. D.; Devara, P. C. S.; Singh, Sacchidanand; Vinod; Dumka, U. C.; Pant, P.

Aerosol black carbon (BC) mass concentrations ([BC]), measured continuously during a mutli-platform field experiment, Integrated Campaign for Aerosols gases and Radiation Budget (ICARB, March-May 2006), from a network of eight observatories spread over geographically distinct environments of India, (which included five mainland stations, one highland station, and two island stations (one each in Arabian Sea and Bay of Bengal)) are examined for their spatio-temporal characteristics. During the period of study, [BC] showed large variations across the country, with values ranging from 27 μg m -3 over industrial/urban locations to as low as 0.065 μg m -3 over the Arabian Sea. For all mainland stations, [BC] remained high compared to highland as well as island stations. Among the island stations, Port Blair (PBR) had higher concentration of BC, compared to Minicoy (MCY), implying more absorbing nature of Bay of Bengal aerosols than Arabian Sea. The highland station Nainital (NTL), in the central Himalayas, showed low values of [BC], comparable or even lower than that of the island station PBR, indicating the prevalence of cleaner environment over there. An examination of the changes in the mean temporal features, as the season advances from winter (December-February) to pre-monsoon (March-May), revealed that: (a) Diurnal variations were pronounced over all the mainland stations, with an afternoon low and a nighttime high; (b) At the islands, the diurnal variations, though resembled those over the mainlands, were less pronounced; and (c) In contrast to this, highland station showed an opposite pattern with an afternoon high and a late night or early morning low. The diurnal variations at all stations are mainly caused by the dynamics of local Atmospheric Boundary Layer (ABL). At the entire mainland as well as island stations (except HYD and DEL), [BC] showed a decreasing trend from January to May. This is attributed to the increased convective mixing and to the resulting enhanced vertical dispersal of species in the ABL. In addition, large short-period modulations were observed at DEL and HYD, which appeared to be episodic. An examination of this in the light of the MODIS-derived fire count data over India along with the back-trajectory analysis revealed that advection of BC from extensive forest fires and biomass-burning regions upwind were largely responsible for this episodic enhancement in BC at HYD and DEL.

Basaloid and warty carcinomas of the vulva. Distinctive types of squamous cell carcinoma frequently associated with human papillomaviruses.

PubMed

Kurman, R J; Toki, T; Schiffman, M H

1993-02-01

In a previous study, we described an elevated prevalence of human papillomavirus (HPV) in two specific types of squamous cell carcinoma of the vulva designated basaloid carcinoma (BC) and warty carcinoma (WC) compared with the conventional type of keratinizing squamous cell carcinoma (KSC). To determine whether there were other differences in their clinical presentation or behavior, we examined 100 cases of squamous cell carcinoma of the vulva classified as BC (28 cases), WC (seven cases), and KSC (65 cases). We included only cases in which tissue adjacent to the tumor was present so that the presence of intraepithelial lesions (squamous hyperplasia, lichen sclerosus, and vulvar intraepithelial neoplasia [VIN]) could be correlated with the different types of invasive carcinomas. Microscopically, BC was characterized by a relatively uniform population of small, ovoid cells with a high nuclear-cytoplasmic ratio resembling VIN 3. Although WC was similar to typical squamous cell carcinoma, it contained many squamous cells that displayed marked nuclear pleomorphism, enlargement, atypia, and multinucleation in conjunction with cytoplasmic cavitation resembling koilocytotic atypia in intraepithelial lesions. The majority of the women with BC and WC were less than 60 years of age, and the proportion of black women was higher as compared with the women with KSC, the majority of whom were white and over 65 years of age. On crude comparison, women with BC appeared to have a survival advantage compared with women with KSC; however, through multivariate modelling, when all possible confounding variables were taken into account, there was little residual impression of a survival advantage of women with BC compared with those having KSC. Substantial differences were found among the three types of carcinoma with regard to the prevalence of adjacent intraepithelial lesions. Squamous hyperplasia was found adjacent to KSC in 54 (83%) of the 65 cases, whereas 27 (77%) of 35 cases of BC and WC had adjacent basaloid or warty VIN. These findings suggest that VIN is a precursor of BC and WC. In view of the high frequency of HPV-DNA detected in VIN and in BC and WC, the findings support the view that HPV has a role in the development of these tumors. In addition, a difference was found in the distribution of associated cervical and vaginal tumors with the three types of vulvar carcinomas.(ABSTRACT TRUNCATED AT 400 WORDS)

Preliminary study of prevalence for bladder cancer in Isfahan Province, Iran.

PubMed

Mazdak, Hamid; Tolou-Ghamari, Zahra

2018-06-01

To clarify period prevalence (PP), incidence rate (Ir), and reported mortality for patients with bladder cancer (BC) in Isfahan Province/Iran, as BC is the most common cancer of the urinary tract in Iran and other parts of the world. Data from 21 March 2011 to 3 March 2015 was obtained from the Isfahan Cancer Registry. BC was distinguished by the related established topography code (C67). Ir and PP were calculated and expressed per 100 000 persons. In all, 279 females and 1376 males were identified. For the total population the PP was calculated as 33.2. This value corresponded to a PP of 54.4 for males and 11.4 for females ( P  < 0.001). Histologically, 63% of patients had invasive BC. Irs versus mortality rates were calculated for each year, i.e. 2011-2012, 2012-2013, 2013-2014, and 2014-2015, as 7.7 vs 0.56, 8.1 vs 0.74, 7.4 vs 0.98, and 9.9 vs 0.84, respectively. The mean (SD, range) age of the patients was 65.2 (13.9, 3-100) years. In relation to the age of the study population, BC occurred in 12% of patients aged <50 years and in 15% of those aged ≥80 years. The PP for BC in the male population was 4.8-times higher than females. There was a 28.6% increase in the Ir over the study period. Further study concerning environmental exposure, genetic factors, job-related exposure to various chemical carcinogens, and geographical distribution in Isfahan and its' rural provinces would seem to be valuable.

Bioanalytical effect-balance model to determine the bioavailability of organic contaminants in sediments affected by black and natural carbon.

PubMed

Bräunig, Jennifer; Tang, Janet Y M; Warne, Michael St J; Escher, Beate I

2016-08-01

In sediments several binding phases dictate the fate and bioavailability of organic contaminants. Black carbon (BC) has a high sorptive capacity for organic contaminants and can limit their bioavailability, while the fraction bound to organic carbon (OC) is considered to be readily desorbable and bioavailable. We investigated the bioavailability and mixture toxicity of sediment-associated contaminants by combining different extraction techniques with in vitro bioanalytical tools. Sediments from a harbour with high fraction of BC, and sediments from remote, agricultural and urban areas with lower BC were treated with exhaustive solvent extraction, Tenax extraction and passive sampling to estimate total, bioaccessible and bioavailable fractions, respectively. The extracts were characterized with cell-based bioassays that measure dioxin-like activity (AhR-CAFLUX) and the adaptive stress response to oxidative stress (AREc32). Resulting bioanalytical equivalents, which are effect-scaled concentrations, were applied in an effect-balance model, consistent with a mass balance-partitioning model for single chemicals. Sediments containing BC had most of the bioactivity associated to the BC fraction, while the OC fraction played a role for sediments with lower BC. As effect-based sediment-water distribution ratios demonstrated, most of the bioactivity in the AhR-CAFLUX was attributable to hydrophobic chemicals while more hydrophilic chemicals activated AREc32, even though bioanalytical equivalents in the aqueous phase remained negligible. This approach can be used to understand the fate and effects of mixtures of diverse organic contaminants in sediments that would not be possible if single chemicals were targeted by chemical analysis; and make informed risk-based decisions concerning the management of contaminated sediments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Statistical, Graphical, and Learning Methods for Sensing, Surveillance, and Navigation Systems

DTIC Science & Technology

2016-06-28

harsh propagation environments. Conventional filtering techniques fail to provide satisfactory performance in many important nonlinear or non...Gaussian scenarios. In addition, there is a lack of a unified methodology for the design and analysis of different filtering techniques. To address...these problems, we have proposed a new filtering methodology called belief condensation (BC) DISTRIBUTION A: Distribution approved for public release

Sensitivity of Stratospheric Geoengineering with Black Carbon to Aerosol Size and Altitude of Injection

NASA Technical Reports Server (NTRS)

Kravitz, Ben; Robock, Alan; Shindell, Drew T.; Miller, Mark A.

2012-01-01

Simulations of stratospheric geoengineering with black carbon (BC) aerosols using a general circulation model with fixed sea surface temperatures show that the climate effects strongly depend on aerosol size and altitude of injection. 1 Tg BC/a injected into the lower stratosphere would cause little surface cooling for large radii but a large amount of surface cooling for small radii and stratospheric warming of over 60 C. With the exception of small particles, increasing the altitude of injection increases surface cooling and stratospheric warming. Stratospheric warming causes global ozone loss by up to 50% in the small radius case. The Antarctic shows less ozone loss due to reduction of polar stratospheric clouds, but strong circumpolar winds would enhance the Arctic ozone hole. Using diesel fuel to produce the aerosols is likely prohibitively expensive and infeasible. Although studying an absorbing aerosol is a useful counterpart to previous studies involving sulfate aerosols, black carbon geoengineering likely carries too many risks to make it a viable option for deployment.

Multifrequency acoustic observations of zooplankton in Knight Inlet, B.C

NASA Astrophysics Data System (ADS)

Trevorrow, Mark V.; Mackas, David L.; Benfield, Mark C.

2004-05-01

A collaborative investigation of midwater zooplankton aggregations in a coastal fjord was conducted in November 2002. Midwater aggregations of zooplankton in a coastal fjord were sampled and mapped using a calibrated, three-frequency (38, 120, and 200 kHz) vessel-based echo-sounder system, a multinet towed zooplankton net (BIONESS), and a high-resolution in situ camera system (ZOOVIS). Dense daytime layers of euphausiids and amphipods near 70- to 90-m depth were found in the lower reaches of the inlet, especially concentrated by tidal flows around a sill which rises above the layer. Quantitative euphausiid and amphipod backscattering measurements, combined with in situ species, size, and abundance estimates, were found to agree closely with recent size- and orientation-averaged fluid-cylinder scattering models produced by Stanton et al. Also, in situ scattering measurements of physonect siphonophores were found to have a much stronger low-frequency (38 kHz) scattering strength, in agreement with a simple bubble scattering model. [Work supported by Dr. J. Eckman, ONR code 322BC.

The influences of ambient particle composition and size on particle infiltration in Los Angeles, CA, residences.

PubMed

Sarnat, Stefanie Ebelt; Coull, Brent A; Ruiz, Pablo A; Koutrakis, Petros; Suh, Helen H

2006-02-01

Particle infiltration is a key determinant of the indoor concentrations of ambient particles. Few studies have examined the influence of particle composition on infiltration, particularly in areas with high concentrations of volatile particles, such as ammonium nitrate (NH4NO3). A comprehensive indoor monitoring study was conducted in 17 Los Angeles-area homes. As part of this study, indoor/outdoor concentration ratios during overnight (nonindoor source) periods were used to estimate the fraction of ambient particles remaining airborne indoors, or the particle infiltration factor (FINF), for fine particles (PM2.5), its nonvolatile (i.e., black carbon [BC]) and volatile (i.e., nitrate [NO3-]) components, and particle sizes ranging between 0.02 and 10 microm. FINF was highest for BC (median = 0.84) and lowest for NO3- (median = 0.18). The low FINF for NO3- was likely because of volatilization of NO3- particles once indoors, in addition to depositional losses upon building entry. The FINF for PM2.5 (median = 0.48) fell between those for BC and NO3-, reflecting the contributions of both particle components to PM25. FINF varied with particle size, air-exchange rate, and outdoor NO3- concentrations. The FINF for particles between 0.7 and 2 microm in size was considerably lower during periods of high as compared with low outdoor NO3- concentrations, suggesting that outdoor NO3- particles were of this size. This study demonstrates that infiltration of PM2.5 varies by particle component and is lowest for volatile species, such as NH4NO3. Our results suggest that volatile particle components may influence the ability for outdoor PM concentrations to represent indoor and, thus, personal exposures to particles of ambient origin, because volatilization of these particles causes the composition of PM2.5 to differ indoors and outdoors. Consequently, particle composition likely influences observed epidemiologic relationships based on outdoor PM concentrations, especially in areas with high concentrations of NH4NO3 and other volatile particles.

Occurrence and factors associated with bovine cysticercosis recorded in cattle at meat inspection in Denmark in 2004-2011.

PubMed

Calvo-Artavia, F F; Nielsen, L R; Dahl, J; Clausen, D M; Alban, L

2013-06-01

Current EU regulation requires that every bovine carcass is examined for bovine cysticercosis (BC) at meat inspection. This is costly and might be superfluous at low BC prevalence. However, from a consumer view-point it may be important to identify and manage infected carcasses to avoid human infection. If relevant data could be effectively used to classify animals with respect to their risk of being infected, then the current meat inspection could be replaced by a more cost-effective system targeting high-risk animals. This study aimed to (1) describe the distribution of BC cases in the Danish cattle population, (2) estimate the animal level prevalence (3) provide descriptive statistics of potential risk factors for BC, and (4) determine attributable risks and fractions of selected risk factors potentially useful for a future risk-based meat inspection system. In total, 348 cases of BC were recorded among all cattle slaughtered (n=4,090,661) in Denmark between 2004 and 2011. The true animal level prevalence of BC was estimated to be 0.06%. The herd of origin of the cases were defined as the herd in which the animals spent most of their lifetimes. The detected cases were found to originate from 328 herds, with a maximum of two cases per herd indicating sporadic occurrence. Even though organic farming was associated with a higher risk (RR=1.9 in univariable analysis) of BC-positive animals being detected at slaughter, the population attributable fraction showed that only 5% of the animals with BC could be attributed to organic farming practices at the level of organic farming practiced in Denmark in the study period. Thus, organic farming status was not a suitable risk factor to use to target future risk-based meat inspection. However, 54% of the animals with BC in the cattle population were attributed to female gender. Increasing age at slaughter was also associated with high risk of BC. There may be overlaps between these effects in animals with multiple risk factors. Other underlying factors such as grazing patterns might explain the risk factors and attribution results found in this study. However, grazing practices are currently not recorded in the Danish cattle database. Therefore, animal level risk factors such as age and gender together with other risk factors such as grazing practices might be included as food chain information, required to be provided by the farmer prior to slaughter. The challenges and opportunities of this approach should be investigated further. Copyright © 2012 Elsevier B.V. All rights reserved.

Aerosols at the poles: an AeroCom Phase II multi-model evaluation

DOE PAGES

Sand, Maria; Samset, Bjorn H.; Balkanski, Yves; ...

2017-10-13

Atmospheric aerosols from anthropogenic and natural sources reach the polar regions through long-range transport and affect the local radiation balance. Such transport is, however, poorly constrained in present-day global climate models, and few multi-model evaluations of polar anthropogenic aerosol radiative forcing exist. Here we compare the aerosol optical depth (AOD) at 550 nm from simulations with 16 global aerosol models from the AeroCom Phase II model intercomparison project with available observations at both poles. We show that the annual mean multi-model median is representative of the observations in Arctic, but that the intermodel spread is large. We also document themore » geographical distribution and seasonal cycle of the AOD for the individual aerosol species: black carbon (BC) from fossil fuel and biomass burning, sulfate, organic aerosols (OAs), dust, and sea-salt. For a subset of models that represent nitrate and secondary organic aerosols (SOAs), we document the role of these aerosols at high latitudes. The seasonal dependence of natural and anthropogenic aerosols differs with natural aerosols peaking in winter (sea-salt) and spring (dust), whereas AOD from anthropogenic aerosols peaks in late spring and summer. The models produce a median annual mean AOD of 0.07 in the Arctic (defined here as north of 60° N). The models also predict a noteworthy aerosol transport to the Antarctic (south of 70° S) with a resulting AOD varying between 0.01 and 0.02. The models have estimated the shortwave anthropogenic radiative forcing contributions to the direct aerosol effect (DAE) associated with BC and OA from fossil fuel and biofuel (FF), sulfate, SOAs, nitrate, and biomass burning from BC and OA emissions combined. The Arctic modelled annual mean DAE is slightly negative (-0.12 W m -2), dominated by a positive BC FF DAE in spring and a negative sulfate DAE in summer. The Antarctic DAE is governed by BC FF. We perform sensitivity experiments with one of the AeroCom models (GISS modelE) to investigate how regional emissions of BC and sulfate and the lifetime of BC influence the Arctic and Antarctic AOD. A doubling of emissions in eastern Asia results in a 33 % increase in Arctic AOD of BC. A doubling of the BC lifetime results in a 39 % increase in Arctic AOD of BC. However, these radical changes still fall within the AeroCom model range.« less

Aerosols at the poles: an AeroCom Phase II multi-model evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sand, Maria; Samset, Bjorn H.; Balkanski, Yves

Atmospheric aerosols from anthropogenic and natural sources reach the polar regions through long-range transport and affect the local radiation balance. Such transport is, however, poorly constrained in present-day global climate models, and few multi-model evaluations of polar anthropogenic aerosol radiative forcing exist. Here we compare the aerosol optical depth (AOD) at 550 nm from simulations with 16 global aerosol models from the AeroCom Phase II model intercomparison project with available observations at both poles. We show that the annual mean multi-model median is representative of the observations in Arctic, but that the intermodel spread is large. We also document themore » geographical distribution and seasonal cycle of the AOD for the individual aerosol species: black carbon (BC) from fossil fuel and biomass burning, sulfate, organic aerosols (OAs), dust, and sea-salt. For a subset of models that represent nitrate and secondary organic aerosols (SOAs), we document the role of these aerosols at high latitudes. The seasonal dependence of natural and anthropogenic aerosols differs with natural aerosols peaking in winter (sea-salt) and spring (dust), whereas AOD from anthropogenic aerosols peaks in late spring and summer. The models produce a median annual mean AOD of 0.07 in the Arctic (defined here as north of 60° N). The models also predict a noteworthy aerosol transport to the Antarctic (south of 70° S) with a resulting AOD varying between 0.01 and 0.02. The models have estimated the shortwave anthropogenic radiative forcing contributions to the direct aerosol effect (DAE) associated with BC and OA from fossil fuel and biofuel (FF), sulfate, SOAs, nitrate, and biomass burning from BC and OA emissions combined. The Arctic modelled annual mean DAE is slightly negative (-0.12 W m -2), dominated by a positive BC FF DAE in spring and a negative sulfate DAE in summer. The Antarctic DAE is governed by BC FF. We perform sensitivity experiments with one of the AeroCom models (GISS modelE) to investigate how regional emissions of BC and sulfate and the lifetime of BC influence the Arctic and Antarctic AOD. A doubling of emissions in eastern Asia results in a 33 % increase in Arctic AOD of BC. A doubling of the BC lifetime results in a 39 % increase in Arctic AOD of BC. However, these radical changes still fall within the AeroCom model range.« less

Soccer science and the Bayes community: exploring the cognitive implications of modern scientific communication.

PubMed

Shrager, Jeff; Billman, Dorrit; Convertino, Gregorio; Massar, J P; Pirolli, Peter

2010-01-01

Science is a form of distributed analysis involving both individual work that produces new knowledge and collaborative work to exchange information with the larger community. There are many particular ways in which individual and community can interact in science, and it is difficult to assess how efficient these are, and what the best way might be to support them. This paper reports on a series of experiments in this area and a prototype implementation using a research platform called CACHE. CACHE both supports experimentation with different structures of interaction between individual and community cognition and serves as a prototype for computational support for those structures. We particularly focus on CACHE-BC, the Bayes community version of CACHE, within which the community can break up analytical tasks into "mind-sized" units and use provenance tracking to keep track of the relationship between these units. Copyright © 2009 Cognitive Science Society, Inc.

Cleaning Study of Genesis Sample 60487

NASA Technical Reports Server (NTRS)

Kuhlman, Kim R.; Rodriquez, M. C.; Gonzalez, C. P.; Allton, J. H.; Burnett, D. S.

2013-01-01

The Genesis mission collected solar wind and brought it back to Earth in order to provide precise knowledge of solar isotopic and elemental compositions. The ions in the solar wind were stopped in the collectors at depths on the order of 10 to a few hundred nanometers. This shallow implantation layer is critical for scientific analysis of the composition of the solar wind and must be preserved throughout sample handling, cleaning, processing, distribution, preparation and analysis. Particles of Genesis wafers, brine from the Utah Testing Range and an organic film have deleterious effects on many of the high-resolution instruments that have been developed to analyze the implanted solar wind. We have conducted a correlative microscopic study of the efficacy of cleaning Genesis samples with megasonically activated ultrapure water and UV/ozone cleaning. Sample 60487, the study sample, is a piece of float-zone silicon from the B/C array approximately 4.995mm x 4.145 mm in size

Brown Carbon and Black Carbon in the Smoky Atmosphere during Boreal Forest Fires

NASA Astrophysics Data System (ADS)

Gorchakov, G. I.; Karpov, A. V.; Pankratova, N. V.; Semoutnikova, E. G.; Vasiliev, A. V.; Gorchakova, I. A.

2017-12-01

We have investigated the variability of smoke aerosol absorbing ability with variations in the content of brown carbon (BrC) and black carbon (BC). Using monitoring data on radiative characteristics of smoke aerosol at AERONET stations and the spatial distribution of aerosol optical depth (AOD) obtained by the MODIS spectrometer ( Terra satellite), we have detected large-scale smokes during boreal forest fires in Russia and Canada (1995-2012). The spatial distribution (50°-70° N, 95°-125° W) and temporal variability (at AERONET station Fort McMurray) of AOD during the smoking of a part of Canada in July 2012 have been analyzed. AOD probability distributions for July 14-18, 2012, and an estimate of aerosol radiative forcing of smoke aerosol at the upper boundary of the atmosphere have been obtained. We have proposed a technique for the diagnostics of BrC and BC in smoke aerosol particles from the spectral dependence of the imaginary part of the refractive index. At a wavelength of 440 nm, the contributions of BrC and BC to the smokeaerosol absorbing abitity can be comparable in magnitude. In many cases, the absorption spectra of smoke aerosol can be adequately approximated by either power or exponential functions. The presence of BrC in smoke-aerosol particles highly extends the variety of observed absorption spectra in a smoky atmosphere and spectral dependences of single scattering albedo. In the spectral range of 440-1020 nm, the radiative characteristics of smoke aerosol are largely contributed by its fine mode.

Russian anthropogenic black carbon: Emission reconstruction and Arctic black carbon simulation

DOE PAGES

Huang, Kan; Fu, Joshua S.; Prikhodko, Vitaly Y.; ...

2015-10-02

Development of reliable source emission inventories is needed to advance the understanding of the origin of Arctic haze using chemical transport modeling. This paper develops a regional anthropogenic black carbon (BC) emission inventory for the Russian Federation, the largest country by land area in the Arctic Council. Activity data from combination of local Russia information and international resources, emission factors based on either Russian documents or adjusted values for local conditions, and other emission source data are used to approximate the BC emissions. Emissions are gridded at a resolution of 0.1° × 0.1° and developed into a monthly temporal profile.more » Total anthropogenic BC emission of Russia in 2010 is estimated to be around 224 Gg. Gas flaring, a commonly ignored black carbon source, contributes a significant fraction of 36.2% to Russia's total anthropogenic BC emissions. Other sectors, i.e., residential, transportation, industry, and power plants, contribute 25.0%, 20.3%, 13.1%, and 5.4%, respectively. Three major BC hot spot regions are identified: the European part of Russia, the southern central part of Russia where human population densities are relatively high, and the Urals Federal District where Russia's major oil and gas fields are located but with sparse human population. BC simulations are conducted using the hemispheric version of Community Multi-scale Air Quality Model with emission inputs from a global emission database EDGAR (Emissions Database for Global Atmospheric Research)-HTAPv2 (Hemispheric Transport of Air Pollution) and EDGAR-HTAPv2 with its Russian part replaced by the newly developed Russian BC emissions, respectively. The simulation using the new Russian BC emission inventory could improve 30–65% of absorption aerosol optical depth measured at the AERONET sites in Russia throughout the whole year as compared to that using the default HTAPv2 emissions. At the four ground monitoring sites (Zeppelin, Barrow, Alert, and Tiksi) in the Arctic Circle, surface BC simulations are improved the most during the Arctic haze periods (October–March). The poor performance of Arctic BC simulations in previous studies may be partly ascribed to the Russian BC emissions built on out-of-date and/or missing information, which could result in biases to both emission rates and the spatial distribution of emissions. Finally, this study highlights that the impact of Russian emissions on the Arctic haze has likely been underestimated, and its role in the Arctic climate system needs to be reassessed. The Russian black carbon emission source data generated in this study can be obtained via http://abci.ornl.gov/download.shtml or http://acs.engr.utk.edu/Data.php.« less

Russian anthropogenic black carbon: Emission reconstruction and Arctic black carbon simulation

NASA Astrophysics Data System (ADS)

Huang, Kan; Fu, Joshua S.; Prikhodko, Vitaly Y.; Storey, John M.; Romanov, Alexander; Hodson, Elke L.; Cresko, Joe; Morozova, Irina; Ignatieva, Yulia; Cabaniss, John

2015-11-01

Development of reliable source emission inventories is particularly needed to advance the understanding of the origin of Arctic haze using chemical transport modeling. This study develops a regional anthropogenic black carbon (BC) emission inventory for the Russian Federation, the largest country by land area in the Arctic Council. Activity data from combination of local Russia information and international resources, emission factors based on either Russian documents or adjusted values for local conditions, and other emission source data are used to approximate the BC emissions. Emissions are gridded at a resolution of 0.1° × 0.1° and developed into a monthly temporal profile. Total anthropogenic BC emission of Russia in 2010 is estimated to be around 224 Gg. Gas flaring, a commonly ignored black carbon source, contributes a significant fraction of 36.2% to Russia's total anthropogenic BC emissions. Other sectors, i.e., residential, transportation, industry, and power plants, contribute 25.0%, 20.3%, 13.1%, and 5.4%, respectively. Three major BC hot spot regions are identified: the European part of Russia, the southern central part of Russia where human population densities are relatively high, and the Urals Federal District where Russia's major oil and gas fields are located but with sparse human population. BC simulations are conducted using the hemispheric version of Community Multi-scale Air Quality Model with emission inputs from a global emission database EDGAR (Emissions Database for Global Atmospheric Research)-HTAPv2 (Hemispheric Transport of Air Pollution) and EDGAR-HTAPv2 with its Russian part replaced by the newly developed Russian BC emissions, respectively. The simulation using the new Russian BC emission inventory could improve 30-65% of absorption aerosol optical depth measured at the AERONET sites in Russia throughout the whole year as compared to that using the default HTAPv2 emissions. At the four ground monitoring sites (Zeppelin, Barrow, Alert, and Tiksi) in the Arctic Circle, surface BC simulations are improved the most during the Arctic haze periods (October-March). The poor performance of Arctic BC simulations in previous studies may be partly ascribed to the Russian BC emissions built on out-of-date and/or missing information, which could result in biases to both emission rates and the spatial distribution of emissions. This study highlights that the impact of Russian emissions on the Arctic haze has likely been underestimated, and its role in the Arctic climate system needs to be reassessed. The Russian black carbon emission source data generated in this study can be obtained via http://abci.ornl.gov/download.shtml or http://acs.engr.utk.edu/Data.php.

Russian anthropogenic black carbon: Emission reconstruction and Arctic black carbon simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Kan; Fu, Joshua S.; Prikhodko, Vitaly Y.

Development of reliable source emission inventories is needed to advance the understanding of the origin of Arctic haze using chemical transport modeling. This paper develops a regional anthropogenic black carbon (BC) emission inventory for the Russian Federation, the largest country by land area in the Arctic Council. Activity data from combination of local Russia information and international resources, emission factors based on either Russian documents or adjusted values for local conditions, and other emission source data are used to approximate the BC emissions. Emissions are gridded at a resolution of 0.1° × 0.1° and developed into a monthly temporal profile.more » Total anthropogenic BC emission of Russia in 2010 is estimated to be around 224 Gg. Gas flaring, a commonly ignored black carbon source, contributes a significant fraction of 36.2% to Russia's total anthropogenic BC emissions. Other sectors, i.e., residential, transportation, industry, and power plants, contribute 25.0%, 20.3%, 13.1%, and 5.4%, respectively. Three major BC hot spot regions are identified: the European part of Russia, the southern central part of Russia where human population densities are relatively high, and the Urals Federal District where Russia's major oil and gas fields are located but with sparse human population. BC simulations are conducted using the hemispheric version of Community Multi-scale Air Quality Model with emission inputs from a global emission database EDGAR (Emissions Database for Global Atmospheric Research)-HTAPv2 (Hemispheric Transport of Air Pollution) and EDGAR-HTAPv2 with its Russian part replaced by the newly developed Russian BC emissions, respectively. The simulation using the new Russian BC emission inventory could improve 30–65% of absorption aerosol optical depth measured at the AERONET sites in Russia throughout the whole year as compared to that using the default HTAPv2 emissions. At the four ground monitoring sites (Zeppelin, Barrow, Alert, and Tiksi) in the Arctic Circle, surface BC simulations are improved the most during the Arctic haze periods (October–March). The poor performance of Arctic BC simulations in previous studies may be partly ascribed to the Russian BC emissions built on out-of-date and/or missing information, which could result in biases to both emission rates and the spatial distribution of emissions. Finally, this study highlights that the impact of Russian emissions on the Arctic haze has likely been underestimated, and its role in the Arctic climate system needs to be reassessed. The Russian black carbon emission source data generated in this study can be obtained via http://abci.ornl.gov/download.shtml or http://acs.engr.utk.edu/Data.php.« less

Investigation of the B1 field distribution and RF power deposition in a birdcage coil as functions of the number of coil legs at 4.7 T, 7.0 T, and 11.7 T

NASA Astrophysics Data System (ADS)

Seo, Jeung-Hoon; Han, Sang-Doc; Kim, Kyoung-Nam

2015-06-01

The proper design of birdcage (BC) coils plays a very important role in the acquisition of highresolution magnetic resonance imaging (MRI) of small animals such as rodents. In this context, we investigate multiple-leg (8-, 16-, 32-, 64-, and 128-leg) BC coils operating at ultra-high fields (UHF) of 7.0 T and 11.7 T and a high-field (HF) of 4.7 T for rodent magnetic resonance imaging (MRI). Primarily, Our study comparatively examines the parameters of the radiofrequency (RF) transmission (|B1 +|)-field, the magnetic flux (|B1|)-field, and RF power deposition (RF-PD) as functions of the number of BC-coil legs via finite-difference time-domain (FDTD) calculations under realistic loading conditions with a biological phantom. In particular, the specific ratio |E/B1 +| is defined for predicting RF-PD values in different coil structures. Our results indicate that the optimal number of legs of the BC coil can be chosen for different resonance frequencies of 200 MHz, 300 MHz, and 500 MHz and that this choice can be lead to superior |B1 +|-field intensity and |B1|-field homogeneity and decreased RF-PD. We believe that our approach to determining the optimal number of legs for a BC coil can contribute to rodent MR imaging.

Decadal-scale trends in regional aerosol particle properties and their linkage to emission changes

NASA Astrophysics Data System (ADS)

Zhao, Bin; Jiang, Jonathan H.; Gu, Yu; Diner, David; Worden, John; Liou, Kuo-Nan; Su, Hui; Xing, Jia; Garay, Michael; Huang, Lei

2017-05-01

Understanding long-term trends in aerosol loading and properties is essential for evaluating the health and climatic effects of these airborne particulates as well as the effectiveness of pollution control policies. While many studies have used satellite data to examine the trends in aerosol optical depth (AOD), very few have investigated the trends in aerosol properties associated with particle size, morphology, and light absorption. In this study, we investigate decadal-scale (13-15 year) trends in aerosol loading and properties during 2001-2015 over three populous regions: the Eastern United States (EUS), Western Europe (WEU), and Eastern and Central China (ECC). We use observations from MISR (Multi-angle Imaging SpectroRadiometer) and MODIS (Moderate resolution Imaging Spectroradiometer). Relationships between aerosol property trends and air pollutant emission changes are examined. We find that annual mean AOD shows pronounced decreasing trends over EUS and WEU regions, as a result of considerable emission reductions in all major pollutants except for mineral dust and ammonia (NH3). Over the ECC region, AOD increases before 2006 due to emission increases induced by rapid economic development, fluctuates between 2006 and 2011, and subsequently decreases after 2011 in conjunction with effective emission reduction in anthropogenic primary aerosols, sulfur dioxide (SO2), and nitrogen oxides (NOx). The fraction of small-size AOD (<0.7 μm diameter), Ångstrom exponent and single-scattering albedo have generally decreased, while the fractions of large-size (>1.4 μm diameter), nonspherical and absorbing AOD have generally shown increasing trends over EUS and WEU regions, indicating that fine and light-scattering aerosol constituents have been more effectively reduced than coarse and light-absorbing constituents. These trends are consistent with the larger reduction ratios in SO2 and NOx emissions than in primary aerosols, including mineral dust and black carbon (BC). Over the ECC region, no significant trends are observed with respect to size distribution, morphology, or light absorption, which we attribute to a simultaneous increase in emissions of SO2, NOx, and primary aerosols including BC before 2006, and a simultaneous decrease after 2011. This study demonstrates the importance and usefulness of satellite-borne sensors, particularly MISR, in association with evaluating the effectiveness of air pollution control policies.

Early Roman military fortifications and the origin of Trieste, Italy.

PubMed

Bernardini, Federico; Vinci, Giacomo; Horvat, Jana; De Min, Angelo; Forte, Emanuele; Furlani, Stefano; Lenaz, Davide; Pipan, Michele; Zhao, Wenke; Sgambati, Alessandro; Potleca, Michele; Micheli, Roberto; Fragiacomo, Andrea; Tuniz, Claudio

2015-03-31

An interdisciplinary study of the archaeological landscape of the Trieste area (northeastern Italy), mainly based on airborne light detection and ranging (LiDAR), ground penetrating radar (GPR), and archaeological surveys, has led to the discovery of an early Roman fortification system, composed of a big central camp (San Rocco) flanked by two minor forts. The most ancient archaeological findings, including a Greco-Italic amphora rim produced in Latium or Campania, provide a relative chronology for the first installation of the structures between the end of the third century B.C. and the first decades of the second century B.C. whereas other materials, such as Lamboglia 2 amphorae and a military footwear hobnail (type D of Alesia), indicate that they maintained a strategic role at least up to the mid first century B.C. According to archaeological data and literary sources, the sites were probably established in connection with the Roman conquest of the Istria peninsula in 178-177 B.C. They were in use, perhaps not continuously, at least until the foundation of Tergeste, the ancestor of Trieste, in the mid first century B.C. The San Rocco site, with its exceptional size and imposing fortifications, is the main known Roman evidence of the Trieste area during this phase and could correspond to the location of the first settlement of Tergeste preceding the colony foundation. This hypothesis would also be supported by literary sources that describe it as a phrourion (Strabo, V, 1, 9, C 215), a term used by ancient writers to designate the fortifications of the Roman army.

Structural, electronic and magnetic properties of chevron-type graphene, BN and BC{sub 2}N nanoribbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guerra, T.; Azevedo, S.; Kaschny, J.R.

2017-04-15

Graphene nanoribbons are predicted to be essential components in future nanoelectronics. The size, edge type, arrangement of atoms and width of nanoribbons drastically change their properties. Boronnitrogencarbon nanoribbons properties are not fully understood so far. In the present contribution it was investigated the structural, electronic and magnetic properties of chevron-type carbon, boron nitride and BC{sub 2}N nanoribbons, using first-principles calculations. The results indicate that the structural stability is closely related to the discrepancies in the bond lengths, which can induce structural deformations and stress. Such nanoribbons present a wide range of electronic behaviors, depending on their composition and particularities ofmore » the atomic arrangement. A net magnetic moment is found for structures that present carbon atoms at the nanoribbon borders. Nevertheless, the calculated magnetic moment depends on the peculiarities of the symmetric arrangement of atoms and imbalance of carbon atoms between different sublattices. It was found that all structures which have a significant energy gap do not present magnetic moment, and vice-versa. Such result indicates the strong correlation between the electronic and magnetic properties of the chevron-type nanoribbons. - Highlights: • Small discrepancies between distinct bond lengths can influence the formation energy of the BC{sub 2}N nanoribbons. • The electronic behavior of the BC{sub 2}N chevron-type nanoribbons depends on the atomic arrangement and structural symmetries. • There is a strong correlation between the electronic and magnetic properties for the BC{sub 2}N structures.« less

Early Roman military fortifications and the origin of Trieste, Italy

PubMed Central

Bernardini, Federico; Vinci, Giacomo; Horvat, Jana; De Min, Angelo; Forte, Emanuele; Furlani, Stefano; Lenaz, Davide; Pipan, Michele; Zhao, Wenke; Sgambati, Alessandro; Potleca, Michele; Micheli, Roberto; Fragiacomo, Andrea; Tuniz, Claudio

2015-01-01

An interdisciplinary study of the archaeological landscape of the Trieste area (northeastern Italy), mainly based on airborne light detection and ranging (LiDAR), ground penetrating radar (GPR), and archaeological surveys, has led to the discovery of an early Roman fortification system, composed of a big central camp (San Rocco) flanked by two minor forts. The most ancient archaeological findings, including a Greco–Italic amphora rim produced in Latium or Campania, provide a relative chronology for the first installation of the structures between the end of the third century B.C. and the first decades of the second century B.C. whereas other materials, such as Lamboglia 2 amphorae and a military footwear hobnail (type D of Alesia), indicate that they maintained a strategic role at least up to the mid first century B.C. According to archaeological data and literary sources, the sites were probably established in connection with the Roman conquest of the Istria peninsula in 178–177 B.C. They were in use, perhaps not continuously, at least until the foundation of Tergeste, the ancestor of Trieste, in the mid first century B.C. The San Rocco site, with its exceptional size and imposing fortifications, is the main known Roman evidence of the Trieste area during this phase and could correspond to the location of the first settlement of Tergeste preceding the colony foundation. This hypothesis would also be supported by literary sources that describe it as a phrourion (Strabo, V, 1, 9, C 215), a term used by ancient writers to designate the fortifications of the Roman army. PMID:25775558

Biochar prepared from castor oil cake at different temperatures: A voltammetric study applied for Pb(2+), Cd(2+) and Cu(2+) ions preconcentration.

PubMed

Kalinke, Cristiane; Mangrich, Antonio Sálvio; Marcolino-Junior, Luiz H; Bergamini, Márcio F

2016-11-15

Biochar is a carbonaceous material similar produced by pyrolysis of biomass under oxygen-limited conditions. Pyrolysis temperature is an important parameter that can alters biochar characteristics (e.g. surface area, pore size distribution and surface functional groups) and affects it efficacy for adsorption of several probes. In this work, biochar samples have been prepared from castor oil cake using different temperatures of pyrolysis (200-600°C). For the first time, a voltammetric procedure based on carbon paste modified electrode (CPME) was used to investigate the effect of temperature of pyrolysis on the adsorptive characteristics of biochar for Pb(II), Cd(II) and Cu(II) ions. Besides the electrochemical techniques, several characterizations have been performed to evaluate the physicochemical properties of biochar in function of the increase of the pyrolysis temperature. Results suggest that biochar pyrolized at 400°C (BC400) showed a better potential for ions adsorption. The CPME modified with BC400 showed better relative current signal with adsorption affinity: Pb(II)>Cd(II)>Cu(II). Kinetic studies revealed that the pseudo-second order model describes more accurately the adsorption process suggesting that the surface reactions control the adsorption rate. Values found for amount adsorbed were 15.94±0.09; 4.29±0.13 and 2.38±0.39μgg(-1) for Pb(II), Cd(II) and Cu(II) ions, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Creating cometary models using ancient Chinese data

NASA Astrophysics Data System (ADS)

Yeomans, D. K.

For more than two millennia, Chinese court astronomers maintained a rather comprehensive record of cometary sightings. Owing to the significance of comets as portents for the reigning emperor, early sky watchers from China (as well as their counterparts from Korea and Japan) carefully noted each cometary apparition for the purpose of astrological predictions. The dates and corresponding celestial locations and motions were usually recorded and in some cases, the colors, coma sizes, and tail lengths were also noted. These ancient observations represent the only source of information available for modeling the long-term behavior of periodic comets. For comets Halley and Swift-Tuttle, Chinese records have been identified as far back as 240 B.C. and 69 B.C. respectively and these data have been used to define their long-term motions. As a result, heliocentric and geocentric distances for each Chinese sighting of these two comets can be computed and estimates can be made for each comet's intrinsic brightness at various observed returns. Although the earliest identified apparition of comet Tempel-Tuttle is A.D. 1366, the associated Leonid meteor showers were noted back to at least A.D. 902. The Leonid meteor stream is young in the sense that outstanding meteor displays occur only near the time of the parent comet's perihelion passages. The ancient Chinese records of the Leonid meteor showers and storms have been used to map the particle distribution around the parent comet and this information was used to guide predictions for the 1998-1999 Leonid meteor showers.

zUMIs - A fast and flexible pipeline to process RNA sequencing data with UMIs.

PubMed

Parekh, Swati; Ziegenhain, Christoph; Vieth, Beate; Enard, Wolfgang; Hellmann, Ines

2018-06-01

Single-cell RNA-sequencing (scRNA-seq) experiments typically analyze hundreds or thousands of cells after amplification of the cDNA. The high throughput is made possible by the early introduction of sample-specific bar codes (BCs), and the amplification bias is alleviated by unique molecular identifiers (UMIs). Thus, the ideal analysis pipeline for scRNA-seq data needs to efficiently tabulate reads according to both BC and UMI. zUMIs is a pipeline that can handle both known and random BCs and also efficiently collapse UMIs, either just for exon mapping reads or for both exon and intron mapping reads. If BC annotation is missing, zUMIs can accurately detect intact cells from the distribution of sequencing reads. Another unique feature of zUMIs is the adaptive downsampling function that facilitates dealing with hugely varying library sizes but also allows the user to evaluate whether the library has been sequenced to saturation. To illustrate the utility of zUMIs, we analyzed a single-nucleus RNA-seq dataset and show that more than 35% of all reads map to introns. Also, we show that these intronic reads are informative about expression levels, significantly increasing the number of detected genes and improving the cluster resolution. zUMIs flexibility makes if possible to accommodate data generated with any of the major scRNA-seq protocols that use BCs and UMIs and is the most feature-rich, fast, and user-friendly pipeline to process such scRNA-seq data.

Characterization of nonpathogenic Listeria species isolated from food and food processing environment.

PubMed

Korsak, Dorota; Szuplewska, Magdalena

2016-12-05

A total of 127 Listeria isolates from food and food processing environments, including 75 L. innocua, 49 L. welshimeri, 2 L. seeligeri and 1L. grayi were tested for susceptibility to eight antimicrobials, benzalkonium chloride (BC), cadmium and arsenic. The isolates were also screened for the presence of extrachromosomal genetic elements - plasmids, and their restriction pattern types were determined. All strains were susceptible to ampicillin, ciprofloxacin, erythromycin, gentamicin, rifampicin, trimethoprim and vancomycin. Two of the L. innocua isolates showed resistance to tetracycline and minocycline. The resistance was determined by the presence of chromosomal localization of tet(M) gene, which was not integrated in the transposon Tn916-Tn1545 family. Of analyzed isolates, 18.11% and 55.91% isolates were resistant to BC and cadmium, respectively, but all were susceptible to arsenic. Resistance to BC was correlated with resistance to cadmium - all BC resistant isolates were also resistant to cadmium. On the other hand, 67.61% of cadmium-resistant isolates were susceptible to BC, suggesting that cadmium and BC resistance were not always concurrent in Listeria species. 48.03% of isolates contained plasmids. The size of most of the identified replicons was in the range of 50-90kb. All plasmids were classified into 12 groups with identical restriction pattern (I-XII). Interestingly, plasmids belonging to the same group were determined in isolates of the same species. Only in one case, plasmids with I-type profile were identified in L. innocua and L. welshimeri. There was an association between resistance to BC and plasmid DNA presence: all resistant isolates carried a plasmid. A correlation between resistance to cadmium and plasmid carriage was also observed in L. innocua and L. seeligeri isolates, but among resistant L. welshimeri, 23.08% of isolates did not have plasmids. This may suggest that resistance is associated with determinants located within the chromosome. To elucidate the adaptation strategies and ecology of Listeria spp., it is important to have a better understanding of its resistance to antimicrobials and environmental toxicants such as heavy metals and disinfectants. Copyright © 2016 Elsevier B.V. All rights reserved.

Investigating the variability in brown carbon light-absorption properties

NASA Astrophysics Data System (ADS)

Saleh, R.; Cheng, Z.; Atwi, K.

2017-12-01

Combustion of biomass fuels contributes a significant portion of brown carbon (BrC), the light-absorbing fraction of organic aerosols. BrC exhibits highly variable light-absorption properties, with imaginary part of the refractive indices (k) reported in the literature varying over two orders of magnitude. This high variability in k is attributed to the chaotic nature of combustion; however, there is a major gap in the fundamental understanding of this variability. To address this gap, we hypothesize that BrC is comprised of black carbon (BC) precursors whose transformation to BC has not seen fruition. Depending on the combustion conditions, these BC precursors exhibit different maturity levels which dictate their light-absorption properties (k). The more mature are the precursors, the more absorptive (or BC-like) they are. Therefore, k of BrC obtained from a certain measurement depends on the specific combustion conditions associated with the measurement, leading to the aforementioned variability in the literature. To test this hypothesis, we performed controlled combustion experiments in which the combustion conditions (temperature and air/fuel ratio) were varied and k was retrieved from real-time multi-wavelength light-absorption measurements at each condition. We used benzene, the inception of which during combustion is the initial critical step leading to BC formation, as a model fuel. By varying the combustion conditions from relatively inefficient (low temperature and/or air/fuel ratio) to relatively efficient (high temperature and/or air/fuel ratio), we isolated BrC components with progressively increasing k, spanning the wide range reported in the literature. We also performed thermodenuder measurements to constrain the volatility of the BrC, as well as laser desorption ionization mass spectrometry analysis to constrain its molecular mass. We found that as the combustion conditions approached the BC-formation threshold, the increase in k was associated with an increase in molecular mass and decrease in volatility. This confirms our hypothesis, since the BC precursors are expected to grow in size and become less volatile as they mature. These results provide the first correlation between the BrC physical, chemical, and consequent light-absorption properties.

A new perspective on the apparent solubility of dissolved black carbon

NASA Astrophysics Data System (ADS)

Wagner, Sasha; Ding, Yan; Jaffé, Rudolf

2017-09-01

Black carbon (BC), pyrogenic organic matter generated from the incomplete combustion of biomass, is ubiquitous in the environment. The molecular structures which comprise the BC pool of compounds are defined by their condensed aromatic core structures polysubstituted with O-containing functionalities (e.g., carboxyl groups). Despite the apparent hydrophobicity of BC molecules, a considerable portion of BC is translocated from terrestrial to aquatic systems in the form of dissolved BC (DBC). However, the specific biogeochemical mechanisms which control the transfer of BC from the land to the water remain elusive. In the current study, the apparent solubility of DBC was inferred from octanol-water partition coefficients (Kow) modeled for proposed DBC structures with varying degrees of polycondensation and polar functionality. Modeled Kow values indicated that DBC molecules with small aromatic ring systems and high degrees of hydrophilic functionality may be truly solubilized in the aqueous phase. However, large and highly condensed DBC structures yielded high Kow values, which suggested that a considerable portion of the DBC pool which has been quantified in aquatic environments is not truly dissolved. We hypothesized that other DOM components may act as mediators in the solubilization of condensed aromatic molecules and serve to increase the solubility of DBC via hydrophobic, intermolecular associations. This hypothesis was tested through controlled leaching experiments to determine whether the mobilization of DBC from particulate soils and chars became enhanced in the presence of DOM. However, we observed that characteristics inherent to each sample type had a greater influence than added DOM on the apparent solubility of DBC. In addition, the direct comparison of molecular marker (benzenepolycarboxylic acids) and ultrahigh resolution mass spectral data (FT-ICR/MS) on leachates obtained from the same set of soils and char did not show a clear overlap in DBC quantification or characterization between the two analytical methods. Correlations between FT-ICR/MS results and BPCA were not significant possibly due to differences in the methodological windows and/or small sample size. Our results were unable to provide evidence in support of proposed hydrophobic interactions between DOM and DBC, suggesting that other physical/chemical mechanisms play important roles in the dissolution of BC.

Visualizing changes in electron distribution in coupled chains of cytochrome bc(1) by modifying barrier for electron transfer between the FeS cluster and heme c(1).

PubMed

Cieluch, Ewelina; Pietryga, Krzysztof; Sarewicz, Marcin; Osyczka, Artur

2010-02-01

Cytochrome c(1) of Rhodobacter (Rba.) species provides a series of mutants which change barriers for electron transfer through the cofactor chains of cytochrome bc(1) by modifying heme c(1) redox midpoint potential. Analysis of post-flash electron distribution in such systems can provide useful information about the contribution of individual reactions to the overall electron flow. In Rba. capsulatus, the non-functional low-potential forms of cytochrome c(1) which are devoid of the disulfide bond naturally present in this protein revert spontaneously by introducing a second-site suppression (mutation A181T) that brings the potential of heme c(1) back to the functionally high levels, yet maintains it some 100 mV lower from the native value. Here we report that the disulfide and the mutation A181T can coexist in one protein but the mutation exerts a dominant effect on the redox properties of heme c(1) and the potential remains at the same lower value as in the disulfide-free form. This establishes effective means to modify a barrier for electron transfer between the FeS cluster and heme c(1) without breaking disulfide. A comparison of the flash-induced electron transfers in native and mutated cytochrome bc(1) revealed significant differences in the post-flash equilibrium distribution of electrons only when the connection of the chains with the quinone pool was interrupted at the level of either of the catalytic sites by the use of specific inhibitors, antimycin or myxothiazol. In the non-inhibited system no such differences were observed. We explain the results using a kinetic model in which a shift in the equilibrium of one reaction influences the equilibrium of all remaining reactions in the cofactor chains. It follows a rather simple description in which the direction of electron flow through the coupled chains of cytochrome bc(1) exclusively depends on the rates of all reversible partial reactions, including the Q/QH2 exchange rate to/from the catalytic sites. 2009 Elsevier B.V. All rights reserved.

SU-C-BRB-05: Determining the Adequacy of Auto-Contouring Via Probabilistic Assessment of Ensuing Treatment Plan Metrics in Comparison with Manual Contours

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nourzadeh, H; Watkins, W; Siebers, J

Purpose: To determine if auto-contour and manual-contour—based plans differ when evaluated with respect to probabilistic coverage metrics and biological model endpoints for prostate IMRT. Methods: Manual and auto-contours were created for 149 CT image sets acquired from 16 unique prostate patients. A single physician manually contoured all images. Auto-contouring was completed utilizing Pinnacle’s Smart Probabilistic Image Contouring Engine (SPICE). For each CT, three different 78 Gy/39 fraction 7-beam IMRT plans are created; PD with drawn ROIs, PAS with auto-contoured ROIs, and PM with auto-contoured OARs with the manually drawn target. For each plan, 1000 virtual treatment simulations with different sampledmore » systematic errors for each simulation and a different sampled random error for each fraction were performed using our in-house GPU-accelerated robustness analyzer tool which reports the statistical probability of achieving dose-volume metrics, NTCP, TCP, and the probability of achieving the optimization criteria for both auto-contoured (AS) and manually drawn (D) ROIs. Metrics are reported for all possible cross-evaluation pairs of ROI types (AS,D) and planning scenarios (PD,PAS,PM). Bhattacharyya coefficient (BC) is calculated to measure the PDF similarities for the dose-volume metric, NTCP, TCP, and objectives with respect to the manually drawn contour evaluated on base plan (D-PD). Results: We observe high BC values (BC≥0.94) for all OAR objectives. BC values of max dose objective on CTV also signify high resemblance (BC≥0.93) between the distributions. On the other hand, BC values for CTV’s D95 and Dmin objectives are small for AS-PM, AS-PD. NTCP distributions are similar across all evaluation pairs, while TCP distributions of AS-PM, AS-PD sustain variations up to %6 compared to other evaluated pairs. Conclusion: No significant probabilistic differences are observed in the metrics when auto-contoured OARs are used. The prostate auto-contour needs improvement to achieve clinically equivalent plans.« less

Recessive resistance to Bean common mosaic virus conferred by the bc-1 and bc-2 genes in common bean (Phaseolus vulgaris L.) affects long distance movement of the virus.

PubMed

Feng, Xue; Orellana, Gardenia; Myers, James; Karasev, Alexander V

2018-04-12

Recessive resistance to Bean common mosaic virus (BCMV) in common bean (Phaseolus vulgaris L.) is governed by four genes that include one strain-nonspecific helper gene bc-u, and three strain-specific genes bc-1, bc-2, and bc-3. The bc-3 gene was identified as an eIF4E translation initiation factor gene mediating resistance through disruption of the interaction between this protein and the VPg protein of the virus. The mode of action of bc-1 and bc-2 in expression of BCMV resistance is unknown, although bc-1 gene was found to affect systemic spread of a related potyvirus, Bean common mosaic necrosis virus. To investigate the possible role of both bc-1 and bc-2 genes in replication, cell-to-cell, and long distance movement of BCMV in P. vulgaris, we tested virus spread of eight BCMV isolates representing pathogroups I, IV, VI, VII, and VIII, in a set of bean differentials expressing different combinations of six resistance alleles including bc-u, bc-1, bc-1 2 , bc-2, bc-2 2 , and bc-3. All studied BCMV isolates were able to replicate and spread in inoculated leaves of bean cultivars harboring bc-u, bc-1, bc-1 2 , bc-2, and bc-2 2 alleles and their combinations, while no BCMV replication was found in inoculated leaves of 'IVT7214' carrying the bc-u, bc-2 and bc-3 genes, except for isolate 1755a capable of overcoming the resistance conferred by bc-2 and bc-3. In contrast, the systemic spread of all BCMV isolates from pathogroups I, IV,VI, VII, and VIII was impaired in common bean cultivars carrying bc-1, bc-1 2 , bc-2, and bc-2 2 alleles. The data suggest that bc-1 and bc-2 recessive resistance genes have no effect on the replication and cell-to-cell movement of BCMV, but affect systemic spread of BCMV in common bean. The BCMV resistance conferred by bc-1 and bc-2 and affecting systemic spread was found only partially effective when these two genes were expressed singly. The efficiency of the restriction of the systemic spread of the virus was greatly enhanced when the alleles of bc-1 and bc-2 genes were combined together.

Osteoarthritis in Siberia's Cis-Baikal: Skeletal indicators of hunter-gatherer adaptation and cultural change.

PubMed

Lieverse, Angela R; Weber, Andrzej W; Bazaliiskiy, Vladimir Ivanovich; Goriunova, Olga Ivanovna; Savel'ev, Nikolai Aleksandrovich

2007-01-01

This examination of osteoarthritis in Siberia's Cis-Baikal region focuses on the reconstruction of mid-Holocene mobility and activity patterns with particular interest in an alleged fifth millennium BC biocultural hiatus. Five cemetery populations--two representing the pre-hiatus Kitoi culture (6800-4900 BC) and three the post-hiatus Serovo-Glaskovo (4200-1000 BC)-are considered. The objective is to investigate osteoarthritic prevalence and distribution (patterning) within and among these populations in order to reconstruct mobility and activity patterns among the Cis-Baikal foragers, and to test for possible disparities that may reflect differing adaptive strategies. The data reveal that levels of activity remained relatively constant throughout the mid-Holocene but that mobility and specific activity patterns did not. Although results are consistent with the current understanding of distinct Kitoi and Serovo-Glaskovo subsistence regimes, specifically the lower residential mobility and narrower resource base of the former, they also draw attention to adaptive characteristics shared by all occupants of the Cis-Baikal. (c) 2006 Wiley-Liss, Inc

Variable-Speed Screw Chiller, Sidney Yates Building, Washington, DC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ostrouchov, George; Adams, Mark B.; Howett, Daniel H.

2017-07-01

This report captures the findings from an evaluation ORNL performed on a new chiller technology as part of GSA's Proving Ground Program. Note: Appendices B&C were removed from this report while the author looks for a way to insert them without consuming over 200MB of file size.

Magnetic dipole transitions of Bc and Bc* mesons in the relativistic independent quark model

NASA Astrophysics Data System (ADS)

Patnaik, Sonali; Dash, P. C.; Kar, Susmita; Patra, Sweta P.; Barik, N.

2017-12-01

We study M1-transitions involving mesons: Bc(1 s ), Bc*(1 s ), Bc(2 s ), Bc*(2 s ), Bc(3 s ), and Bc*(3 s ) in the relativistic independent quark (RIQ) model based on a flavor independent average potential in the scalar-vector harmonic form. The transition form factor for Bc*→Bcγ is found to have analytical continuation from spacelike to physical timelike region. Our predicted coupling constant gBc*Bc=0.34 GeV-1 and decay width Γ (Bc*→Bcγ )=23 eV agree with other model predictions. In view of possible observation of Bc and Bc* s-wave states at LHC and Z-factory and potential use of theoretical estimate on M1-transitions, we investigate the allowed as well as hindered transitions of orbitally excited Bc-meson states and predict their decay widths in overall agreement with other model predictions. We consider the typical case of Bc*(1 s )→Bc(1 s )γ , where our predicted decay width which is found quite sensitive to the mass difference between Bc* and Bc mesons may help in determining the mass of Bc* experimentally.

Dendrochronologically dated pine stumps document phase-wise bog expansion at a northwest German site between ca. 6700 and ca. 3400 BC

NASA Astrophysics Data System (ADS)

Maike Achterberg, Inke Elisabeth; Eckstein, Jan; Birkholz, Bernhard; Bauerochse, Andreas; Leuschner, Hanns Hubert

2018-01-01

The investigated northwest German mire site at Totes Moor is densely covered with subfossil pine stumps (Pinus sylvestris L.) from the fen-bog transition. This facilitates the spatio-temporal reconstruction of mire development, which is based on 212 in situ tree stumps in the case study presented here. Six dendrochronologically dated site chronologies together cover 2345 years between 6703 and 3403 BC. The gaps in between are 6 to 550 years long. Additionally, a floating chronology of 309 years, containing 30 trees, was radiocarbon-dated to the beginning of the 7th millennium cal BC. Peat-stratigraphical survey was carried out additionally, and elevations a.s.l. were determined at several locations. Tree dying-off phases, which indicate water level rise at the site, mostly in context of the local fen-bog transition, are evident for ca. 6600-6450, ca. 6350-5750, ca. 5300-4900, ca. 4700-4550, ca. 3900-3850, ca. 3700-3600, ca. 3500-3450 and ca. 3400 BC. The spatial distribution of the dated in situ trees illustrates the phase-wise expansion of raised bog over fen peat at the site. The documented bog expansion pulses likely correspond to climatic wet sifts.

Double heterozygotes among breast cancer patients analyzed for BRCA1, CHEK2, ATM, NBN/NBS1, and BLM germ-line mutations.

PubMed

Sokolenko, Anna P; Bogdanova, Natalia; Kluzniak, Wojciech; Preobrazhenskaya, Elena V; Kuligina, Ekatherina S; Iyevleva, Aglaya G; Aleksakhina, Svetlana N; Mitiushkina, Natalia V; Gorodnova, Tatiana V; Bessonov, Alexandr A; Togo, Alexandr V; Lubiński, Jan; Cybulski, Cezary; Jakubowska, Anna; Dörk, Thilo; Imyanitov, Evgeny N

2014-06-01

17 double heterozygous (DH) breast cancer (BC) patients were identified upon the analysis of 5,391 affected women for recurrent Slavic mutations in BRCA1, CHEK2, NBN/NBS1, ATM, and BLM genes. Double heterozygosity was found for BRCA1 and BLM (4 patients), BRCA1 and CHEK2 (4 patients), CHEK2 and NBS1 (3 patients), BRCA1 and ATM (2 patients), CHEK2 and BLM (2 patients), CHEK2 and ATM (1 patient), and NBS1 and BLM (1 patient). DH BC patients were on average not younger than single mutation carriers and did not have an excess of bilateral BC; an additional non-breast tumor was documented in two BRCA1/BLM DH patients (ovarian cancer and lymphoplasmacytic lymphoma). Loss-of-heterozygosity (LOH) analysis of involved genes was performed in 5 tumors, and revealed a single instance of somatic loss of the wild-type allele (LOH at CHEK2 locus in BRCA1/CHEK2 double heterozygote). Distribution of mutations in patients and controls favors the hypothesis on multiplicative interaction between at least some of the analyzed genes. Other studies on double heterozygosity for BC-predisposing germ-line mutations are reviewed.

Cell Proliferation (KI-67) Expression Is Associated with Poorer Prognosis in Nigerian Compared to British Breast Cancer Women

PubMed Central

Agboola, Ayodeji O. J.; Banjo, Adekumbiola A. F.; Anunobi, Charles C.; Salami, Babatunde; Agboola, Mopelola Deji; Musa, Adewale A.; Nolan, Christopher C.; Rakha, Emad A.; Ellis, Ian O.; Green, Andrew R.

2013-01-01

Background. Black women with breast cancer (BC) in Nigeria have higher mortality rate compared with British women. This study investigated prognostic features of cell proliferation biomarker (Ki-67) in Nigerian breast cancer women. Materials and Methods. The protein expression of Ki-67 was investigated in series of 308 Nigerian women, prepared as a tissue microarray (TMA), using immunohistochemistry. Clinic-pathological parameters, biomarkers, and patient outcome of tumours expressing Ki-67 in Nigerian women were correlated with UK grade-matched series. Results. A significantly larger proportion of breast tumours from Nigerian women showed high Ki-67 expression. Those tumours were significantly correlated with negative expression of the steroid hormone receptors (ER and PgR), p21, p27, E-cadherin, BRCA-1, and Bcl-2 (all P < 0.001), but positively associated with EGFR (P = 0.003), p53, basal cytokeratins: CK56, CK14, triple negative, and basal phenotype using Nielsen's classification (all P < 0.001) compared to UK women. Multivariate analyses showed that race was also associated with BCSS independent of tumour size, lymph node status, and ER status. Conclusion. Ki-67 expression was observed to have contributed to the difference in the BCSS in Nigerian compared with British BC women. Therefore, targeting Ki-67 in the indigenous black women with BC might improve the patient outcome in the black women with BC. PMID:23691362

Systematic review of breast cancer biology in developing countries (part 1): Africa, the middle East, eastern europe, Mexico, the Caribbean and South america.

PubMed

Bhikoo, Riyaz; Srinivasa, Sanket; Yu, Tzu-Chieh; Moss, David; Hill, Andrew G

2011-05-13

There has been no systematic appraisal of ethnicity-based variations in breast cancer (BC) biology amongst women from developing countries. A qualitative systematic review was conducted of breast cancer size, stage, grade, histological type, extra-mammary involvement, hormone receptor status as well as patient demographics. This review includes patients from Africa, the Middle East, Eastern Europe, Mexico, the Caribbean and South America. BC in these regions present at an earlier age with large aggressive tumours. Distant metastases are frequently present at the time of diagnosis. African women have a higher frequency of triple negative tumours. Over half of Middle Eastern women have lymph node involvement at the time of diagnosis. Despite experiencing a lower incidence compared to the Ashkenazi Jewish population, Palestinian women have poorer five-year survival outcomes. The majority of women from Mexico and South America have stage two or three disease whilst over sixty percent of women from Eastern Europe have either stage one or stage two disease. The biological characteristics of BC in the Caribbean cannot be fully assessed due to a paucity of data from the region. BC amongst the developing world is characterised by an early peak age of onset with aggressive biological characteristics. Strategies that improve breast cancer awareness, address amenable risk factors and improve early detection are essential.

Systematic review of breast cancer biology in developing countries (part 2): asian subcontinent and South East Asia.

PubMed

Bhikoo, Riyaz; Srinivasa, Sanket; Yu, Tzu-Chieh; Moss, David; Hill, Andrew G

2011-05-13

There has been no systematic appraisal of ethnicity-based variations in breast cancer (BC) biology amongst women from developing countries. A qualitative systematic review was conducted of breast cancer size, stage, grade, histological type, extra-mammary involvement, hormone receptor status as well as patient demographics. This review includes patients from Africa, the Middle East, Eastern Europe, Mexico, the Caribbean and South America. BC in these regions present at an earlier age with large aggressive tumours. Distant metastases are frequently present at the time of diagnosis. African women have a higher frequency of triple negative tumours. Over half of Middle Eastern women have lymph node involvement at the time of diagnosis. Despite experiencing a lower incidence compared to the Ashkenazi Jewish population, Palestinian women have poorer five-year survival outcomes. The majority of women from Mexico and South America have stage two or three disease whilst over sixty percent of women from Eastern Europe have either stage one or stage two disease. The biological characteristics of BC in the Caribbean cannot be fully assessed due to a paucity of data from the region. BC amongst the developing world is characterised by an early peak age of onset with aggressive biological characteristics. Strategies that improve breast cancer awareness, address amenable risk factors and improve early detection are essential.

Characterization of air pollutant concentrations, fleet emission factors, and dispersion near a North Carolina interstate freeway across two seasons

NASA Astrophysics Data System (ADS)

Saha, Provat K.; Khlystov, Andrey; Snyder, Michelle G.; Grieshop, Andrew P.

2018-03-01

We present field measurement data and modeling of multiple traffic-related air pollutants during two seasons at a site adjoining Interstate 40, near Durham, North Carolina. We analyze spatial-temporal and seasonal trends and fleet-average pollutant emission factors and use our data to evaluate a line source dispersion model. Month-long measurement campaigns were performed in summer 2015 and winter 2016. Data were collected at a fixed near-road site located within 10 m from the highway edge, an upwind background site and, under favorable meteorological conditions, along downwind perpendicular transects. Measurements included the size distribution, chemical composition, and volatility of submicron particles, black carbon (BC), nitrogen oxides (NOx), meteorological conditions and traffic activity data. Results show strong seasonal and diurnal differences in spatial distribution of traffic sourced pollutants. A strong signature of vehicle emissions was observed within 100-150 m from the highway edge with significantly higher concentrations during morning. Substantially higher concentrations and less-sharp near-road gradients were observed in winter for many species. Season-specific fleet-average fuel-based emission factors for NO, NOx, BC, and particle number (PN) were derived based on up- and down-wind roadside measurements. The campaign-average NOx and PN emission factors were 20% and 300% higher in winter than summer, respectively. These results suggest that the combined effect of higher emissions and their slower downwind dispersion in winter dictate the observed higher downwind concentrations and wider highway influence zone in winter for several species. Finally, measurements of traffic data, emission factors, and pollutant concentrations were integrated to evaluate a line source dispersion model (R-LINE). The dispersion model captured the general trends in the spatial and temporal patterns in near-road concentrations. However, there was a tendency for the model to under-predict concentrations near the road in the mornings and over-predict concentrations in the evenings.

[Molecular-genetic analysis of wheat (T. aestivum L.) genome with introgression of Ae. cylindrica Host genetic elements].

PubMed

Galaev, A V; Sivolap, Iu M

2005-01-01

Wheat-aegilops hybrid plants Triticum aestivum L. (2n = 42) x Aegilops cylindrica Host (2n = 28) were investigated with using microsatellite markers. In two BC1F9 lines some genome modifications connected with losing DNA fragments of initial variety or appearing of Aegilops genome elements were detected. In some investigated hybrids new amplicons lacking in parental plants were found. Substitution of wheat chromosomes for aegilops chromosomes was not revealed. Analysis of microsatellite loci in BC2F5 plants showed stable introgression of aegilops genetic elements into wheat; elimination of some transferred aegilops DNA fragments in the course of backcrossing; decreasing size of introgressive elements after backcrossing. Introgressive lines were classified according to genome changes.

Cloud Condensation Nuclei and Chemical Composition of size-resolved particles in a Brazilian megacity: Effect of NPF event, biomass burning and sea salt from remote regions on the CCN properties

NASA Astrophysics Data System (ADS)

Souto-Oliveira, Carlos; de Fátima Andrade, Maria; Kumar, Prashant; Lopes, Fabio; Babinski, Marly; Landulfo, Eduado; Vara-Vela, Angel

2016-04-01

Atmospheric aerosol particles are an important source of cloud condensation nuclei (CCN). Their microphysics and chemical composition can directly affect development of clouds and precipitation process1,2. Only a few studies in Latin American have reported the impact of urban aerosol on the formation of CCN and their contribution to global climate change3. In this study, we simultaneously measured size distributed particle number concentration (PNC), CCN, black carbon (BC) and elemental concentrations (EC) in aerosol samples from São Paulo city. The PNC was measured by DMPS (model 3936) operated with a DMA (model 3080) and CPC (TSI, model 3010). The CCN was measuredby a single-column continuous-flow stream-wise thermal gradient CCN chamber (DMT CCNC-100). The BC and EC were determined in polycarbonate filter collected by Cascade Impactor (MOUDI-MSP), using a smoke stain reflectometer and an ED-XRF (EDX 700; Shimadzu), respectively. During the study period, which was August to September 2014, four events of new particle formation (NPF), characterizing secondary process of aerosol formation were noted. The total PNC varied between 1106 and 29168 cm-3, while CCN presented concentrations of 206 to 12761 cm-3for SS=1.0%. The PNC showed different concentrations during diurnal and nocturnal periods with average of 16392±7811 cm-3 and 6874±3444cm-3, respectively. The activated ratio (CCN/CN) presented diurnal and nocturnal values of 0.19±0.10 and 0.41±0.18, while apparent activation diameter (Dact,a) was estimated to be 110±29 and 71±28 nm (SS=0.6%), respectively. Combining EC and BC results with air mass trajectory analysis (Lidar aerosol profiles and Hysplit air trajectories), apportionment events were identified for sea salt and biomass burning from coastal and continental regions, respectively. The nocturnal AR and Dact,apresented values of 0.46±0.11 and 49±15 nm (SS=0.6%) for sea salt events as opposed to 0.33±0.14 and 64±30 nm (SS=0.6%) during biomass burning events. Although statistically not robust, it was observed diurnal and nocturnal tendencies for CCN properties (AR, Dact,a), which were accompanied by small variability for sea salt and biomass burning events. References [1] Andreae et al. (2004). Science, 303, 1337-1342. [2] Andreae, M. O., and Rosenfeld, D. (2008). Earth-Science Reviews, 89, 13-41. [3] Almeida et al. Atmospheric Chemistry and Physics, 14, 7559-7572.

Association of calcium sensing receptor polymorphisms at rs1801725 with circulating calcium in breast cancer patients.

PubMed

Wang, Li; Widatalla, Sarrah E; Whalen, Diva S; Ochieng, Josiah; Sakwe, Amos M

2017-08-02

Breast cancer (BC) patients with late-stage and/or rapidly growing tumors are prone to develop high serum calcium levels which have been shown to be associated with larger and aggressive breast tumors in post and premenopausal women respectively. Given the pivotal role of the calcium sensing receptor (CaSR) in calcium homeostasis, we evaluated whether polymorphisms of the CASR gene at rs1801725 and rs1801726 SNPs in exon 7, are associated with circulating calcium levels in African American and Caucasian control subjects and BC cases. In this retrospective case-control study, we assessed the mean circulating calcium levels, the distribution of two inactivating CaSR SNPs at rs1801725 and rs1801726 in 199 cases and 384 age-matched controls, and used multivariable regression analysis to determine whether these SNPs are associated with circulating calcium in control subjects and BC cases. We found that the mean circulating calcium levels in African American subjects were higher than those in Caucasian subjects (p < 0.001). As expected, the mean calcium levels were higher in BC cases compared to control subjects (p < 0.001), but the calcium levels in BC patients were independent of race. We also show that in BC cases and control subjects, the major alleles at rs1801725 (G/T, A986S) and at rs1801726 (C/G, Q1011E) were common among Caucasians and African Americans respectively. Compared to the wild type alleles, polymorphisms at the rs1801725 SNP were associated with higher calcium levels (p = 0.006) while those at rs1801726 were not. Using multivariable linear mixed-effects models and adjusting for age and race, we show that circulating calcium levels in BC cases were associated with tumor grade (p = 0.009), clinical stage (p = 0.003) and more importantly, with inactivating mutations of the CASR at the rs1801725 SNP (p = 0.038). These data suggest that decreased sensitivity of the CaSR to calcium due to inactivating polymorphisms at rs1801725, may predispose up to 20% of BC cases to high circulating calcium-associated larger and/or aggressive breast tumors.

On the Red Giant Branch: Ambiguity in the Surface Boundary Condition Leads to ≈100 K Uncertainty in Model Effective Temperatures

NASA Astrophysics Data System (ADS)

Choi, Jieun; Dotter, Aaron; Conroy, Charlie; Ting, Yuan-Sen

2018-06-01

The effective temperature (T eff) distribution of stellar evolution models along the red giant branch (RGB) is sensitive to a number of parameters including the overall metallicity, elemental abundance patterns, the efficiency of convection, and the treatment of the surface boundary condition (BC). Recently there has been interest in using observational estimates of the RGB T eff to place constraints on the mixing length parameter, α MLT, and possible variation with metallicity. Here we use 1D Modules for Experiments in Stellar Astrophysics (MESA) stellar evolution models to explore the sensitivity of the RGB T eff to the treatment of the surface BC. We find that different surface BCs can lead to ±100 K metallicity-dependent offsets on the RGB relative to one another in spite of the fact that all models can reproduce the properties of the Sun. Moreover, for a given atmosphere T–τ relation, we find that the RGB T eff is also sensitive to the optical depth at which the surface BC is applied in the stellar model. Nearly all models adopt the photosphere as the location of the surface BC, but this choice is somewhat arbitrary. We compare our models to stellar parameters derived from the APOGEE-Kepler sample of first ascent red giants and find that systematic uncertainties in the models due to treatment of the surface BC place a limit of ≈100 K below which it is not possible to make firm conclusions regarding the fidelity of the current generation of stellar models.

Electronic Inventory Systems and Barcode Technology: Impact on Pharmacy Technical Accuracy and Error Liability

PubMed Central

Oldland, Alan R.; May, Sondra K.; Barber, Gerard R.; Stolpman, Nancy M.

2015-01-01

Purpose: To measure the effects associated with sequential implementation of electronic medication storage and inventory systems and product verification devices on pharmacy technical accuracy and rates of potential medication dispensing errors in an academic medical center. Methods: During four 28-day periods of observation, pharmacists recorded all technical errors identified at the final visual check of pharmaceuticals prior to dispensing. Technical filling errors involving deviations from order-specific selection of product, dosage form, strength, or quantity were documented when dispensing medications using (a) a conventional unit dose (UD) drug distribution system, (b) an electronic storage and inventory system utilizing automated dispensing cabinets (ADCs) within the pharmacy, (c) ADCs combined with barcode (BC) verification, and (d) ADCs and BC verification utilized with changes in product labeling and individualized personnel training in systems application. Results: Using a conventional UD system, the overall incidence of technical error was 0.157% (24/15,271). Following implementation of ADCs, the comparative overall incidence of technical error was 0.135% (10/7,379; P = .841). Following implementation of BC scanning, the comparative overall incidence of technical error was 0.137% (27/19,708; P = .729). Subsequent changes in product labeling and intensified staff training in the use of BC systems was associated with a decrease in the rate of technical error to 0.050% (13/26,200; P = .002). Conclusions: Pharmacy ADCs and BC systems provide complementary effects that improve technical accuracy and reduce the incidence of potential medication dispensing errors if this technology is used with comprehensive personnel training. PMID:25684799

Effect of saikosaponins and extracts of vinegar-baked Bupleuri Radix on the activity of β-glucuronidase.

PubMed

Chen, Xianzhi; Yu, Tongya; Chen, Zhenxing; Zhao, Ruizhi; Mao, Shirui

2014-09-01

In Traditional Chinese Medicine, liver targeting is usually achieved by coadministration with Vinegar-baked Radix Bupleuri (VBRB), but the mechanism is unclear. In this paper, the influence of VBRB on the activity of β-glucuronidase was investigated and compared with that of saikosaponins. The activity of β-glucuronidase was measured by microplate reader using a 4-nitrophenyl-β-d-glucuronide substrate. The change of 4-nitrophenol content was used to characterize the activity of β-glucuronidase. Bupleurum chinenes were found to be the inhibitor of β-glucuronidase. The inhibition rate of Bupleurum chinenes extracts BC1 (high molecular weight polysaccharides), BC2 (ethanol soluble/water insoluble component), BC3 (extracted by n-butanol, soluble in water), and BC4 (low molecular weight water soluble parts) on the activity of β-glucuronidase was found to be 45.15%, 33.94%, 24.94%, and 34.54%, respectively, after 1 h incubation, with BC1 showing the highest inhibition rate. In contrast, the saikosaponins were demonstrated to be the promoter of β-glucuronidase, with promotion rates of 333.56%, 217.04%, 247.87%, 149.75%, and 92.50% for saikosaponin standard samples A, B, B2, C, and D, respectively, (p<0.05). In conclusion, inhibiting the activity of β-glucuronidase might be one of the reasons why VBRB could influence drug distribution upon its coadministration with other drugs. Since saikosaponins and VBRB extracts have opposite effect, more attention should be paid to the content of saikosaponins in the extracts upon its application.

Crystal Structure of Biotin Carboxylase in Complex with Substrates and Implications for Its Catalytic Mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chou, C.; Yu, L; Tong, L

2009-01-01

Biotin-dependent carboxylases are widely distributed in nature and have important functions in many cellular processes. These enzymes share a conserved biotin carboxylase (BC) component, which catalyzes the ATP-dependent carboxylation of biotin using bicarbonate as the donor. Despite the availability of a large amount of biochemical and structural information on BC, the molecular basis for its catalysis is currently still poorly understood. We report here the crystal structure at 2.0 {angstrom} resolution of wild-type Escherichia coli BC in complex with its substrates biotin, bicarbonate, and Mg-ADP. The structure suggests that Glu{sup 296} is the general base that extracts the proton frommore » bicarbonate, and Arg{sup 338} is the residue that stabilizes the enolate biotin intermediate in the carboxylation reaction. The B domain of BC is positioned closer to the active site, leading to a 2-{angstrom} shift in the bound position of the adenine nucleotide and bringing it near the bicarbonate for catalysis. One of the oxygen atoms of bicarbonate is located in the correct position to initiate the nucleophilic attack on ATP to form the carboxyphosphate intermediate. This oxygen is also located close to the N1' atom of biotin, providing strong evidence that the phosphate group, derived from decomposition of carboxyphosphate, is the general base that extracts the proton on this N1' atom. The structural observations are supported by mutagenesis and kinetic studies. Overall, this first structure of BC in complex with substrates offers unprecedented insights into the molecular mechanism for the catalysis by this family of enzymes.« less

Electronic inventory systems and barcode technology: impact on pharmacy technical accuracy and error liability.

PubMed

Oldland, Alan R; Golightly, Larry K; May, Sondra K; Barber, Gerard R; Stolpman, Nancy M

2015-01-01

To measure the effects associated with sequential implementation of electronic medication storage and inventory systems and product verification devices on pharmacy technical accuracy and rates of potential medication dispensing errors in an academic medical center. During four 28-day periods of observation, pharmacists recorded all technical errors identified at the final visual check of pharmaceuticals prior to dispensing. Technical filling errors involving deviations from order-specific selection of product, dosage form, strength, or quantity were documented when dispensing medications using (a) a conventional unit dose (UD) drug distribution system, (b) an electronic storage and inventory system utilizing automated dispensing cabinets (ADCs) within the pharmacy, (c) ADCs combined with barcode (BC) verification, and (d) ADCs and BC verification utilized with changes in product labeling and individualized personnel training in systems application. Using a conventional UD system, the overall incidence of technical error was 0.157% (24/15,271). Following implementation of ADCs, the comparative overall incidence of technical error was 0.135% (10/7,379; P = .841). Following implementation of BC scanning, the comparative overall incidence of technical error was 0.137% (27/19,708; P = .729). Subsequent changes in product labeling and intensified staff training in the use of BC systems was associated with a decrease in the rate of technical error to 0.050% (13/26,200; P = .002). Pharmacy ADCs and BC systems provide complementary effects that improve technical accuracy and reduce the incidence of potential medication dispensing errors if this technology is used with comprehensive personnel training.

Dose distribution in the thyroid gland following radiation therapy of breast cancer--a retrospective study.

PubMed

Johansen, S; Reinertsen, K V; Knutstad, K; Olsen, D R; Fosså, S D

2011-06-09

To relate the development of post-treatment hypothyroidism with the dose distribution within the thyroid gland in breast cancer (BC) patients treated with loco-regional radiotherapy (RT). In two groups of BC patients postoperatively irradiated by computer tomography (CT)-based RT, the individual dose distributions in the thyroid gland were compared with each other; Cases developed post-treatment hypothyroidism after multimodal treatment including 4-field RT technique. Matched patients in Controls remained free for hypothyroidism. Based on each patient's dose volume histogram (DVH) the volume percentages of the thyroid absorbing respectively 20, 30, 40 and 50 Gy were then estimated (V20, V30, V40 and V50) together with the individual mean thyroid dose over the whole gland (MeanTotGy). The mean and median thyroid dose for the included patients was about 30 Gy, subsequently the total volume of the thyroid gland (VolTotGy) and the absolute volumes (cm3) receiving respectively <30 Gy and ≥30 Gy were calculated (Vol<30 and Vol≥30) and analyzed. No statistically significant inter-group differences were found between V20, V30, V40 and V50Gy or the median of MeanTotGy. The median VolTotGy in Controls was 2.3 times above VolTotGy in Cases (ρ=0.003), with large inter-individual variations in both groups. The volume of the thyroid gland receiving<30 Gy in Controls was almost 2.5 times greater than the comparable figure in Cases. We concluded that in patients with small thyroid glands after loco-radiotherapy of BC, the risk of post-treatment hypothyroidism depends on the volume of the thyroid gland.

Distinct oxidative stabilities of char versus soot black carbon: Implications for quantification and environmental recalcitrance

NASA Astrophysics Data System (ADS)

Elmquist, Marie; Cornelissen, Gerard; Kukulska, Zofia; Gustafsson, Örjan

2006-06-01

Sequestration in sediments of black carbon (BC) from vegetation fires and fuel combustion may constitute a significant sink of otherwise rapidly cycling carbon from the atmosphere-biosphere cycle. It also has the potential to provide a historical record of atmospheric BC loadings. Previous treatments of BC as one homogeneous entity are being replaced with the growing awareness of a BC combustion continuum, a range spanning from slightly charred biomass to soot and graphite. Here the relative recalcitrance of different BC forms is evaluated, and implications for both BC quantification and environmental stability are considered. The stabilities of four BC reference materials against thermal oxidation in air were quite distinct with T50%BC values (i.e., the temperature where 50% BC remained in the residue) of 444°C (diesel soot-BC), 388°C (n-hexane soot-BC), 338°C (wood char-BC), and 266°C (grass char-BC). The implications for BC quantification have been illustrated for a thermal oxidation (the CTO-375) method commonly applied to study BC in sediments. This technique measured BC:TOC ratios of 78.3 ± 1.3% for the diesel soot-BC and 45.3 ± 6.1% for n-hexane soot-BC, whereas no CTO375-BC was detected for the two analyzed char-BC materials. The greater lability of char-BC compared to soot-BC likely reflects higher accessibility to internal microporosity in char-BC, facilitating internal O2 transfer. Decreasing the temperature cutoff below 375°C to also include char-BC is not possible as thermograms of nonpyrogenic reference materials indicated that such material would then be artifactually quantified as BC. The presence of mineral oxides in the sediment matrix may lead to a catalytically mediated lowering of the activation energy for soot-BC oxidation but not for char-BC or nonpyrogenic organic material. Several recent studies combine to challenge the proposition of complete recalcitrance of BC. Particularly, the thermal lability of char-BC from grassland fires deserves further attention in order to improve the understanding of BC in the global carbon cycle.

Single-Centre Experience with Percutaneous Cryoablation of Breast Cancer in 23 Consecutive Non-surgical Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cazzato, Roberto Luigi, E-mail: r.cazzato@unicampus.it; Lara, Christine Tunon de, E-mail: c.tunondelara@bordeaux.unicancer.fr; Buy, Xavier, E-mail: x.buy@bordeaux.unicancer.fr

AimTo present our single-centre prospective experience on the use of cryoablation (CA) applied to treat primary breast cancer (BC) in a cohort of patients unsuitable for surgical treatment.Materials and MethodsTwenty-three consecutive post-menopausal female patients (median age 85 years; range 56–96) underwent percutaneous CA of unifocal, biopsy-proven BC, under ultrasound/computed tomography (US/CT) guidance. Clinical and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) follow-ups were systematically scheduled at 3, 12, 18 and 24 months. Local tumour control was assessed by comparing baseline and follow-up DCE-MRI.ResultsTwenty-three BC (median size 14 mm) were treated under local anaesthesia (78.3 %) or local anaesthesia and conscious sedation (21.7 %). Median number ofmore » cryo-probes applied per session was 2.0. A “dual-freezing” protocol was applied for the first ten patients and a more aggressive “triple-freezing” protocol for the remaining 13. Median follow-up was 14.6 months. Five patients recurred during follow-up and two were successfully re-treated with CA. Five patients presented immediate CA-related complications: four hematomas evolved uneventfully at 3-month follow-up and one skin burn resulted in skin inflammation and skin retraction at 3 and 12 months, respectively.ConclusionsPercutaneous CA is safe and well tolerated for non-resected elderly BC patients. Procedures can be proposed under local anaesthesia only. Given the insulation properties of the breast gland, aggressive CA protocols are required. Prospective studies are needed to better understand the potential role of CA in the local treatment of early BC.« less

Does the relief of glucose toxicity act as a mediator in proliferative actions of vanadium on pancreatic islet beta cells in streptozocin diabetic rats?

PubMed

Pirmoradi, Leila; Mohammadi, Mohammad Taghi; Safaei, Akbar; Mesbah, Fakhardin; Dehghani, Gholam Abbas

2014-07-01

Data shows vanadium protects pancreatic beta cells (BC) from diabetic animals. Whether this effect is direct or through the relief of glucose toxicity is not clear. This study evaluated the potential effect of oral vanadyl sulfate (vanadium) on glycemic status and pancreatic BC of normal and diabetic rats. Rats were divided into five groups of normal and diabetic. Diabetes was induced with streptozocin (40 mg/kg, i.v.). Normal rats used water (CN) or vanadium (1 mg/ml VOSO4, VTN). Diabetic rats used water (CD), water plus daily neutral protamine Hagedorn insulin injection (80 U/kg, ITD) or vanadium (VTD). Blood samples were taken for blood glucose (BG, mg/dL) and insulin (ng/dL) measurements. After two months, the pancreata of sacrificed rats were prepared for islet staining. Pre-treated normal BG was 88 ± 2, and diabetic BG was 395 ± 9. The final BG in CD, VTD, and ITD was 509 ± 22, 138 ± 14, and 141 ± 14, respectively. Insulin in VTN (0.75 ± 0.01) and VTD (0.78 ± 0.01) was similar, higher than CD (0.51 ± 0.07) but lower than CN (2.51 ± 0.02). VTN islets compared to CN had larger size and denser central core insulin immunoreactivity with plentiful BC. CD and ITD islets were atrophied and had scattered insulin immunoreactivity spots and low BC mass. VTD islets were almost similar to CN. Besides insulin-like activity, vanadium protected pancreatic islet BC, and the relief of glucose toxicity happening with vanadium had a little role in this action.

Does the Relief of Glucose Toxicity Act As a Mediator in Proliferative Actions of Vanadium on Pancreatic Islet Beta Cells in Streptozocin Diabetic Rats?

PubMed Central

Pirmoradi, Leila; Mohammadi, Mohammad Taghi; Safaei, Akbar; Mesbah, Fakhardin; Dehghani, Gholam Abbas

2014-01-01

Background: Data shows vanadium protects pancreatic beta cells (BC) from diabetic animals. Whether this effect is direct or through the relief of glucose toxicity is not clear. This study evaluated the potential effect of oral vanadyl sulfate (vanadium) on glycemic status and pancreatic BC of normal and diabetic rats. Methods: Rats were divided into five groups of normal and diabetic. Diabetes was induced with streptozocin (40 mg/kg, i.v.). Normal rats used water (CN) or vanadium (1 mg/ml VOSO4, VTN). Diabetic rats used water (CD), water plus daily neutral protamine Hagedorn insulin injection (80 U/kg, ITD) or vanadium (VTD). Blood samples were taken for blood glucose (BG, mg/dL) and insulin (ng/dL) measurements. After two months, the pancreata of sacrificed rats were prepared for islet staining. Results: Pre-treated normal BG was 88 ± 2, and diabetic BG was 395 ± 9. The final BG in CD, VTD, and ITD was 509 ± 22, 138 ± 14, and 141 ± 14, respectively. Insulin in VTN (0.75 ± 0.01) and VTD (0.78 ± 0.01) was similar, higher than CD (0.51 ± 0.07) but lower than CN (2.51 ± 0.02). VTN islets compared to CN had larger size and denser central core insulin immunoreactivity with plentiful BC. CD and ITD islets were atrophied and had scattered insulin immunoreactivity spots and low BC mass. VTD islets were almost similar to CN. Conclusion: Besides insulin-like activity, vanadium protected pancreatic islet BC, and the relief of glucose toxicity happening with vanadium had a little role in this action. PMID:24842144

Comparison of Local Recurrence Among Early Breast Cancer Patients Treated With Electron Intraoperative Radiotherapy vs Hypofractionated Photon Radiotherapy an Observational Study.

PubMed

Guenzi, Marina; Bonzano, Elisabetta; Corvò, Renzo; Merolla, Francesca; Pastorino, Alice; Cavagnetto, Francesca; Garelli, Stefania; Cutolo, Carlo Alberto; Friedman, Daniele; Belgioia, Liliana

2018-01-01

To evaluate local recurrence (LR) in women with early breast cancer (BC) who underwent intraoperative radiation therapy with electrons particles (IORT-E) or adjuvant hypofractionated external radiotherapy (HYPOFX). We retrospectively analyzed 470 patients with early BC treated at our center from September 2009 to December 2012. 235 women were treated with breast-conserving surgery and immediate IORT-E (21 Gy/1 fraction) while 235 patients underwent wide excision followed by hypofractionated whole-breast irradiation. Radiotherapy modality was chosen according to an individualized decision based on tumor features, stage, technical feasibility, age, and acceptance to be enrolled in the IORT-E group. After a median follow-up of 6 years, we observed 8 (3.4%) and 1 (0.42%) LR in the IORT-E and in the HYPOFX group ( p  = 0.02), respectively. The two groups differed in the prevalence of clinical characteristics ( p  < 0.05): age, tumor size, surgical margins, receptors, ki67, and histology. 4 and 1 woman in the IORT-E and HYPOFX group died of BC, respectively ( p  = 0.167). OS and DFS hazard ratio [HR] were 2.14 (95% IC, 1.10-4.15) and 2.09 (95% IC, 1.17-3.73), respectively. Our comparison showed that IORT-E and HYPOFX are two effective radiotherapy modalities after conservative surgery in early BC. However, at 6 years a significant higher rate of LR occurred in patients submitted to IORT-E with respect to HYPOFX. This finding may be correlated to some subsets of patients who, depending on the biological characteristics of the BC, may be less suitable to IORT-E.

Total body surface area overestimation at referring institutions in children transferred to a burn center.

PubMed

Swords, Douglas S; Hadley, Edmund D; Swett, Katrina R; Pranikoff, Thomas

2015-01-01

Total body surface area (TBSA) burned is a powerful descriptor of burn severity and influences the volume of resuscitation required in burn patients. The incidence and severity of TBSA overestimation by referring institutions (RIs) in children transferred to a burn center (BC) are unclear. The association between TBSA overestimation and overresuscitation is unknown as is that between TBSA overestimation and outcome. The trauma registry at a BC was queried over 7.25 years for children presenting with burns. TBSA estimate at RIs and BC, total fluid volume given before arrival at a BC, demographic variables, and clinical variables were reviewed. Nearly 20 per cent of children arrived from RIs without TBSA estimation. Nearly 50 per cent were overestimated by 5 per cent or greater TBSA and burn sizes were overestimated by up to 44 per cent TBSA. Average TBSA measured at BC was 9.5 ± 8.3 per cent compared with 15.5 ± 11.8 per cent as measured at RIs (P < 0.0001). Burns between 10 and 19.9 per cent TBSA were overestimated most often and by the greatest amounts. There was a statistically significant relationship between overestimation of TBSA by 5 per cent or greater and overresuscitation by 10 mL/kg or greater (P = 0.02). No patient demographic or clinical factors were associated with TBSA overestimation. Education efforts aimed at emergency department physicians regarding the importance of always calculating TBSA as well as the mechanics of TBSA estimation and calculating resuscitation volume are needed. Further studies should evaluate the association of TBSA overestimation by RIs with adverse outcomes and complications in the burned child.

Rooting depth and root depth distribution of Trifolium repens × T. uniflorum interspecific hybrids.

PubMed

Nichols, S N; Hofmann, R W; Williams, W M; van Koten, C

2016-05-20

Traits related to root depth distribution were examined in Trifolium repens × T. uniflorum backcross 1 (BC 1 ) hybrids to determine whether root characteristics of white clover could be improved by interspecific hybridization. Two white clover cultivars, two T. uniflorum accessions and two BC 1 populations were grown in 1 -m deep tubes of sand culture. Maximum rooting depth and root mass distribution were measured at four harvests over time, and root distribution data were fitted with a regression model to provide measures of root system shape. Morphological traits were measured at two depths at harvest 3. Root system shape of the hybrids was more similar to T. uniflorum than to white clover. The hybrids and T. uniflorum had a higher rate of decrease in root mass with depth than white clover, which would result in higher proportions of root mass in the upper profile. Percentage total root mass at 100-200 mm depth was higher for T. uniflorum than white clover, and for Crusader BC 1 than 'Crusader'. Roots of the hybrids and T. uniflorum also penetrated deeper than those of white clover. T. uniflorum had thicker roots at 50-100 mm deep than the other entries, and more of its fine root mass at 400-500 mm. The hybrids and white clover had more of their fine root mass higher in the profile. Consequently, T. uniflorum had a higher root length density at 400-500 mm than most entries, and a smaller decrease in root length density with depth. These results demonstrate that rooting characteristics of white clover can be altered by hybridization with T. uniflorum, potentially improving water and nutrient acquisition and drought resistance. Root traits of T. uniflorum are likely to be adaptations to soil moisture and fertility in its natural environment. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Rooting depth and root depth distribution of Trifolium repens × T. uniflorum interspecific hybrids

PubMed Central

Nichols, S. N.; Hofmann, R. W.; Williams, W. M.; van Koten, C.

2016-01-01

Background and aims Traits related to root depth distribution were examined in Trifolium repens × T. uniflorum backcross 1 (BC1) hybrids to determine whether root characteristics of white clover could be improved by interspecific hybridization. Methods Two white clover cultivars, two T. uniflorum accessions and two BC1 populations were grown in 1 -m deep tubes of sand culture. Maximum rooting depth and root mass distribution were measured at four harvests over time, and root distribution data were fitted with a regression model to provide measures of root system shape. Morphological traits were measured at two depths at harvest 3. Key Results Root system shape of the hybrids was more similar to T. uniflorum than to white clover. The hybrids and T. uniflorum had a higher rate of decrease in root mass with depth than white clover, which would result in higher proportions of root mass in the upper profile. Percentage total root mass at 100–200 mm depth was higher for T. uniflorum than white clover, and for Crusader BC1 than ‘Crusader’. Roots of the hybrids and T. uniflorum also penetrated deeper than those of white clover. T. uniflorum had thicker roots at 50–100 mm deep than the other entries, and more of its fine root mass at 400–500 mm. The hybrids and white clover had more of their fine root mass higher in the profile. Consequently, T. uniflorum had a higher root length density at 400–500 mm than most entries, and a smaller decrease in root length density with depth. Conclusions These results demonstrate that rooting characteristics of white clover can be altered by hybridization with T. uniflorum, potentially improving water and nutrient acquisition and drought resistance. Root traits of T. uniflorum are likely to be adaptations to soil moisture and fertility in its natural environment. PMID:27208735

Estimating the extent and distribution of new-onset adult asthma in British Columbia using frequentist and Bayesian approaches.

PubMed

Beach, Jeremy; Burstyn, Igor; Cherry, Nicola

2012-07-01

We previously described a method to identify the incidence of new-onset adult asthma (NOAA) in Alberta by industry and occupation, utilizing Workers' Compensation Board (WCB) and physician billing data. The aim of this study was to extend this method to data from British Columbia (BC) so as to compare the two provinces and to incorporate Bayesian methodology into estimates of risk. WCB claims for any reason 1995-2004 were linked to physician billing data. NOAA was defined as a billing for asthma (ICD-9 493) in the 12 months before a WCB claim without asthma in the previous 3 years. Incidence was calculated by occupation and industry. In a matched case-referent analysis, associations with exposures were examined using an asthma-specific job exposure matrix (JEM). Posterior distributions from the Alberta analysis and estimated misclassification parameters were used as priors in the Bayesian analysis of the BC data. Among 1 118 239 eligible WCB claims the incidence of NOAA was 1.4%. Sixteen occupations and 44 industries had a significantly increased risk; six industries had a decreased risk. The JEM identified wood dust [odds ratio (OR) 1.55, 95% confidence interval (CI) 1.08-2.24] and animal antigens (OR 1.66, 95% CI 1.17-2.36) as related to an increased risk of NOAA. Exposure to isocyanates was associated with decreased risk (OR 0.57, 95% CI 0.39-0.85). Bayesian analyses taking account of exposure misclassification and informative priors resulted in posterior distributions of ORs with lower boundary of 95% credible intervals >1.00 for almost all exposures. The distribution of NOAA in BC appeared somewhat similar to that in Alberta, except for isocyanates. Bayesian analyses allowed incorporation of prior evidence into risk estimates, permitting reconsideration of the apparently protective effect of isocyanate exposure.

Characterizing the Vertical and Spatial Distribution of Black Carbon on the North Slope of Alaska

NASA Astrophysics Data System (ADS)

Sedlacek, A. J., III; Feng, Y.; Biraud, S.; Springston, S. R.

2016-12-01

The Polar Regions are recognized for their pronounced sensitivity to changes in radiative forcing. Indeed, the Cryosphere is often referred to as the `canary in the coalmine' for climate change in the popular literature. It is this sensitivity that provides both motivation and need for targeted measurement campaigns to test the behavior and predictive capabilities of current climate models to so as to improve our understanding of which factors are most important in Arctic climate change. One class of under measured radiative forcing agents in the Polar Region is the absorbing aerosol - black carbon and brown carbon. In particular, the paucity of vertical profile information of BC is partly responsible for the difficulty of reducing uncertainty in model assessment of aerosol radiative impact at high latitudes. During the summer of 2015, a Single-Particle Soot Photometer (SP2) was deployed aboard the DOE Gultstream-1 (G-1) aircraft to measure refractory BC (rBC) concentrations as part of the DOE-sponsored ACME-V (ARM Airborne Carbon Measurements) campaign. This campaign was conducted from June through to mid-September along the North Slope of Alaska and was punctuated by vertical profiling over 5 sites (Atquasuk, Barrow, Ivotuk, Oliktok, and Toolik). In addition, measurement of CO, CO2 and CH4 were also taken to provide information on the spatial and seasonal differences in GHG sources and how these sources correlate with BC. Comparisons between observations and a global climate model (CAM5) simulations will be shown along with a discussion on the ability of the model to capture observed monthly mean profiles of BC and stratified aerosol layers. Additionally, the capability of the SP2 to partition rBC-containing particles into nascent or aged allows an evaluation of how well the CAM5 model captures long distant transported aged carbonaceous aerosols. Finally model sensitivity studies will be presented that investigated the relative importance of the different emission sectors to the summer Arctic BC loadings at different altitudes and the implications of these emissions on the radiation budget.

Vertical and Spatial Profiling of Arctic Black Carbon on the North Slope of Alaska 2015: Comparison of Model and Observation

NASA Astrophysics Data System (ADS)

Sedlacek, A. J., III; Feng, Y.; Biraud, S.; Springston, S. R.

2015-12-01

One of the major issues confronting aerosol climate simulations of the Arctic and Antarctic Cryospheres is the lack of detailed data on the vertical and spatial distribution of aerosols with which to test these models. This is due, in part, to the inherent difficulty of conducting such measurements in extreme environments. One class of under measured radiative forcing agents in the Polar Region is the absorbing aerosol - black carbon and brown carbon. In particular, vertical profile information of BC is critical in reducing uncertainty in model assessment of aerosol radiative impact at high latitudes. During the summer of 2015, a Single-Particle Soot Photometer (SP2) was deployed aboard the Department of Energy (DOE) Gultstream-1 (G-1) aircraft to measure refractory BC (rBC) concentrations as part of the DOE-sponsored ACME-V (ARM Airborne Carbon Measurements) campaign. This campaign was conducted from June through to mid-September along the North Slope of Alaska and was punctuated by vertical profiling over 5 sites (Atquasuk, Barrow, Ivotuk, Oliktok, and Toolik). In addition, measurement of CO, CO2 and CH4were also taken to provide information on the spatial and seasonal differences in GHG sources and how these sources correlate with BC. Lastly, these aerosol and gas measurements provide an important dataset to assess the representativeness of ground sites at regional scales. Comparisons between observations and a global climate model (CAM5) simulations will be agumented with a discussion on the capability of the model to capture observed monthly mean profiles of BC and stratified aerosol layers. Additionally, the ability of the SP2 to partition rBC-containing particles into nascent or aged species allows an evaluation of how well the CAM5 model captures aging of long distant transported carbonaceous aerosols. Finally model sensitivity studies will be aso be presented that investigated the relative importance of the different emission sectors to the summer Arctic BC loadings at different altitudes and the implications of these emissions on the radiation budget.

Transport of particle pollution into the Maipo Valley: winter 2015 campaign results

NASA Astrophysics Data System (ADS)

Huneeus, Nicolás; Mazzeo, Andrea; Ordóñez, César; Donoso, Nicolás; Gallardo, Laura; Molina, Luisa; Moreno, Valeria; Muñoz, Ricardo; Orfanoz, Andrea; Vizcarra, Aldo

2016-04-01

Each winter, Santiago (33° 27'S, 70° 40'W) the capital of Chile with a population of about 7 million people, experiences episodes with particulate matter (PM) concentrations larger than allowed by Chilean environmental regulations. Transport and residential heating largely dominate emissions prior to and during these episodes. Important impact of black carbon (BC) on the cryosphere has been documented in other parts of the world associated with urban pollution. In order to explore if BC from Santiago has the potential to reach the Andean cryosphere during the aforementioned episodes, a one week-long campaign was conducted in Santiago and the Maipo Valley between 18th and 25th of July 2015 when the air quality conditions of the city reached twice the critical levels (pre-emergency in Chilean regulations). Measurements were carried out at three sites: downtown Santiago, the entrance of the valley (and outskirts of Santiago) and 12 km inside the Maipo Valley. At each of these sites both surface and vertically distributed measurements were conducted. A meteorological station measuring standard meteorological parameters and an E-Sampler measuring PM10 concentrations were installed at each site. In addition, a tethered balloon equipped with a sonde and a mini-aethalometer was used in each site to measure vertical profiles of standard meteorological parameters and BC concentrations, respectively. The tethered balloon was raised every three hours up to a maximum of 1000 meters above ground level, whenever meteorological conditions allowed. In general, the BC concentrations inside the valley, both at the surface and in the vertical, were dominated by emissions within the valley and BC was limited to shallow layers above the ground. However, on both days with critical air quality levels, winds blowing from the city and deeper BC layers were observed inside the valley. Furthermore, during these days observations at the entrance of the valley and those taken inside were coupled, contrary to the other days when they were decoupled. This deeper BC layer and the coupling of observations at the entrance and inside the valley suggest that pollutants are transported into the Maipo Valley and thus could potentially reach the snow and ice covered areas in the Andes.

How well is black carbon in the Arctic atmosphere captured by models?

NASA Astrophysics Data System (ADS)

Eckhardt, Sabine; Berntsen, Terje; Cherian, Ribu; Daskalakis, Nikos; Heyes, Chris; Hodnebrog, Øivind; Kanakidou, Maria; Klimont, Zbigniew; Law, Kathy; Lund, Marianne; Myhre, Gunnar; Myriokefalitakis, Stelios; Olivie, Dirk; Quaas, Johannes; Quennehen, Boris; Raut, Jean-Christophe; Samset, Bjørn; Schulz, Michael; Skeie, Ragnhild; Stohl, Andreas

2014-05-01

A correct representation of the spatial distribution of aerosols in atmospheric models is essential for realistic simulations of deposition and calculations of radiative forcing. It has been observed that transport of black carbon (BC) into the Arctic and scavenging is sometimes not captured accurately enough in chemistry transport models (CTM) as well as global circulation models (GCM). In this study we determine the discrepancies between measured equivalent BC (EBC) and modeled BC for several Arctic measurement stations as well as for Arctic aircraft campaigns. For this, we use the output of a set of 5 models based on the same emission dataset (ECLIPSE emissions, see eclipse.nilu.no) and evaluate the simulated concentrations at the measurement locations and times. Emissions are separated for different sources such as biomass burning, domestic heating, gas flaring, industry and the transport sector. We focus on the years 2008 and 2009, where many campaigns took place in the framework of the International Polar Year. Arctic stations like Barrow, Alert, Station Nord in Greenland and Zeppelin show a very pronounced winter/spring maximum in BC. While monthly averaged measured EBC values are around 80 ng/m^3, the models severely underestimate this with some models simulating only a small percentage of the observed values. During summer measured concentrations are a magnitude lower, and still underestimated by almost an order of magnitude in some models. However, the best models are correct within a factor of 2 in winter/spring and give realistic concentrations in summer. In order to get information on the vertical profile we used measurements from aircraft campaigns like ARCTAS, ARCPAC and HIPPO. It is found that BC in latitudes below 60 degrees is better captured by the models than BC at higher latitudes, even though it is overestimated at high altitudes. A systematic analysis of the performance of different models is presented. With the dataset we use we capture remote, polluted and fire-influenced conditions. We estimate the impact of model deficiencies on calculated BC radiative forcing by introducing scaling factors based on the model-measurement comparisons.

Climatic changes and social transformations in the Near East and North Africa during the 'long' 4th millennium BC: A comparative study of environmental and archaeological evidence

NASA Astrophysics Data System (ADS)

Clarke, Joanne; Brooks, Nick; Banning, Edward B.; Bar-Matthews, Miryam; Campbell, Stuart; Clare, Lee; Cremaschi, Mauro; di Lernia, Savino; Drake, Nick; Gallinaro, Marina; Manning, Sturt; Nicoll, Kathleen; Philip, Graham; Rosen, Steve; Schoop, Ulf-Dietrich; Tafuri, Mary Anne; Weninger, Bernhard; Zerboni, Andrea

2016-03-01

This paper explores the possible links between rapid climate change (RCC) and social change in the Near East and surrounding regions (Anatolia, central Syria, southern Israel, Mesopotamia, Cyprus and eastern and central Sahara) during the 'long' 4th millennium (∼4500-3000) BC. Twenty terrestrial and 20 marine climate proxies are used to identify long-term trends in humidity involving transitions from humid to arid conditions and vice versa. The frequency distribution of episodes of relative aridity across these records is calculated for the period 6300-2000 BC, so that the results may be interpreted in the context of the established arid episodes associated with RCC around 6200 and 2200 BC (the 8.2 and 4.2 kyr events). We identify two distinct episodes of heightened aridity in the early-mid 4th, and late 4th millennium BC. These episodes cluster strongly at 3600-3700 and 3100-3300 BC. There is also evidence of localised aridity spikes in the 5th and 6th millennia BC. These results are used as context for the interpretation of regional and local archaeological records with a particular focus on case studies from western Syria, the middle Euphrates, southern Israel and Cyprus. Interpretation of the records involves the construction of plausible narratives of human-climate interaction informed by concepts of adaptation and resilience from the literature on contemporary (i.e. 21st century) climate change and adaptation. The results are presented alongside well-documented examples of climatically-influenced societal change in the central and eastern Sahara, where detailed geomorphological studies of ancient environments have been undertaken in tandem with archaeological research. While the narratives for the Near East and Eastern Mediterranean remain somewhat speculative, the use of resilience and adaptation frameworks allows for a more nuanced treatment of human-climate interactions and recognises the diversity and context-specificity of human responses to climatic and environmental change. Our results demonstrate that there is a need for more local environmental data to be collected 'at source' during archaeological excavations.

Ecosystem services trade-offs and determinants in China's Yangtze River Economic Belt from 2000 to 2015.

PubMed

Xu, Xibao; Yang, Guishan; Tan, Yan; Liu, Jingping; Hu, Huizhi

2018-09-01

Ecosystem services (ES) play an important role in sustaining ecological security, sustainable development and human well-being. This study investigates spatio-temporal changes in five key ES in the Yangtze River Economic Belt of China in 2000-2015-water conservation (WC), soil retention (SR), carbon sequestration (CS), biodiversity conservation (BC) and food supply (FS), by applying three ecological models (InVEST, RUSLE, CASA). Employing scenario simulations, the study quantifies distinct effects of significant factors on ES changes. Using spatial overlapping and Spearman's rank correlation respectively, the study distinguishes spatial patterns of synergies and trade-offs between five ES at the grid and city-scales. The results show that CS, FS, WC and SR presented an overall upward trend, increasing by 22.7%, 16.9%, 6.4% and 4.7%, respectively, while BC remained steady with a marginal degradation. Change in these five ES exhibited dramatic spatial heterogeneity. Across 131 cities, 98.5% of which increased in CS, 87.7% in WC, 68.5% in FS, and 53.1% in SR, while more than half experienced slight degradation in BC. There is high heterogeneity and a great diversity among spatial distributions of ES synergies and trade-offs, which is largely dependent on ES pairs and spatial patterns of land use. Land use/land cover change was the dominant force driving changes in SR, BC and CS, while meteorological factors exhibited a greater effect on WS change than land use/land cover change. The paper examines the synergies between WC-SR, CS-BC and BC-FS on the city level, while WC-BC exhibits significant trade-offs, and no significant relationships for other ES pairs. It is imperative that ES trade-offs at different scales are incorporated to strengthen ecological protection and management policies in project implementation, maintaining ES within vital regions in China. More sophisticated methods and more ES indicators need to be incorporated to enhance the robustness and completeness of assessment. Copyright © 2018 Elsevier B.V. All rights reserved.

Black Carbon and Sulfate Aerosols in the Arctic: Long-term Trends, Radiative Impacts, and Source Attributions

NASA Astrophysics Data System (ADS)

Wang, H.; Zhang, R.; Yang, Y.; Smith, S.; Rasch, P. J.

2017-12-01

The Arctic has warmed dramatically in recent decades. As one of the important short-lived climate forcers, aerosols affect the Arctic radiative budget directly by interfering radiation and indirectly by modifying clouds. Light-absorbing particles (e.g., black carbon) in snow/ice can reduce the surface albedo. The direct radiative impact of aerosols on the Arctic climate can be either warming or cooling, depending on their composition and location, which can further alter the poleward heat transport. Anthropogenic emissions, especially, BC and SO2, have changed drastically in low/mid-latitude source regions in the past few decades. Arctic surface observations at some locations show that BC and sulfate aerosols had a decreasing trend in the recent decades. In order to understand the impact of long-term emission changes on aerosols and their radiative effects, we use the Community Earth System Model (CESM) equipped with an explicit BC and sulfur source-tagging technique to quantify the source-receptor relationships and decadal trends of Arctic sulfate and BC and to identify variations in their atmospheric transport pathways from lower latitudes. The simulation was conducted for 36 years (1979-2014) with prescribed sea surface temperatures and sea ice concentrations. To minimize potential biases in modeled large-scale circulations, wind fields in the simulation are nudged toward an atmospheric reanalysis dataset, while atmospheric constituents including water vapor, clouds, and aerosols are allowed to evolve according to the model physics. Both anthropogenic and open fire emissions came from the newly released CMIP6 datasets, which show strong regional trends in BC and SO2 emissions during the simulation time period. Results show that emissions from East Asia and South Asia together have the largest contributions to Arctic sulfate and BC concentrations in the upper troposphere, which have an increasing trend. The strong decrease in emissions from Europe, Russia and North America contributed significantly to the overall decreasing trend in Arctic BC and sulfate, especially, in the lower troposphere. The long-term changes in the spatial distributions of aerosols, their radiative impacts and source attributions, along with implications for the Arctic warming trend, will be discussed.

Abundance and distribution of microplastics within surface sediments of a key shellfish growing region of Canada.

PubMed

Kazmiruk, T N; Kazmiruk, V D; Bendell, L I

2018-01-01

The abundance and distribution of microplastics within 5 sediment size classes (>5000 μm, 1000-5000 μm, 250-1000 μm, 250-0.63 μm and < 0.63 μm) were determined for 16 sites within Lambert Channel and Baynes Sound, British Columbia, Canada. This region is Canada's premier growing area for the Pacific oyster (Crassostrea gigas). Microplastics were found at all sampling locations indicating widespread contamination of this region with these particles. Three types of microplastics were recovered: microbeads, which occurred in the greatest number (up to 25000/kg dry sediment) and microfibers and microfragments, which were much less in number compared with microbeads and occurred in similar amounts (100-300/kg dry sediment). Microbeads were recovered primarily in the < 0.63 μm and 250-0.63 μm sediment size class, whereas microfragments and microfibers were generally identified in all 5 sediment size classes. Abundance and distribution of the three types of microplastics were spatially dependent with principal component analysis (PCA) indicating that 84 percent of the variation in abundance and distribution was due to the presence of high numbers of microbeads at three locations within the study region. At these sites, microbeads expressed as a percent component of the sediment by weight was similar to key geochemical components that govern trace metal behavior and availability to benthic organisms. Microbeads have been shown to accumulate metals from the aquatic environment, hence in addition to the traditional geochemical components such as silt and organic matter, microplastics also need to be considered as a sediment component that can influence trace metal geochemistry. Our findings have shown that BC's premier oyster growing region is highly contaminated with microplastics, notably microbeads. It would be prudent to assess the degree to which oysters from this region are ingesting microplastics. If so, it would have direct implications for Canada's oyster farming industry with respect to the health of the oyster and the quality of product that is being farmed and sets an example for other shellfish growing regions of the world.

Efficiency gain of marker-assisted backcrossing by sequentially increasing marker densities over generations.

PubMed

Prigge, Vanessa; Melchinger, Albrecht E; Dhillon, Baldev S; Frisch, Matthias

2009-06-01

Expenses for marker assays are the major costs in marker-assisted backcrossing programs for the transfer of target genes from a donor into the genetic background of a recipient genotype. Our objectives were to (1) investigate the effect of employing sequentially increasing marker densities over backcross generations on the recurrent parent genome (RPG) recovery and the number of marker data points (MDP) required, and (2) determine optimum designs for attaining RPG thresholds of 93-98% with a minimum number of MDP. We simulated the introgression of one dominant target gene for genome models of sugar beet (Beta vulgaris L.) and maize (Zea mays L.) with varying marker distances of 5-80 cM and population sizes of 30-250 plants across BC(1) to BC(3) generations. Employing less dense maps in early backcross generations resulted in savings of over 50% in the number of required MDP compared with using a constant set of markers and was accompanied only by small reductions in the attained RPG values. The optimum designs were characterized by increasing marker densities and increasing population sizes in advanced generations for both genome models. We conclude that increasing simultaneously the marker density and the population size from early to advanced backcross generations results in gene introgression with a minimum number of required MDP.

Cross-Sectional Associations between Body Size, Circulating Sex-Steroid Hormones and IGF Components among Healthy Chinese Women.

PubMed

McCullough, Lauren E; Miller, Erline E; Wang, Qiong; Li, Jia-Yuan; Liu, Li; Li, Hui; Zhang, Jing; Smith, Jennifer S

2015-01-01

The incidence of breast cancer has increased in Asian countries and rates of hormone receptor (HR) negative breast cancer exceed those of Western countries. Epidemiologic data suggest that the association between body size and BC risk may vary by HR status, and could differ geographically. While body size may influence BC risk by moderating the synthesis and metabolism of circulating sex-steroid hormones, insulin-like growth factor (IGF)-1 and related binding proteins, there is a dearth of literature among Asian women. We aimed to examine these specific associations in a sample of Chinese women. In Sichuan Province 143 women aged ≥40 years were recruited through outpatient services (2011-2012). Questionnaires, anthropometric measurements, and blood samples were utilized for data collection and linear regression was applied in data analyses. Among women <50 years we observed a non-monotonic positive association between body mass index (BMI) and 17β-estradiol, and a reversed J-shaped association between BMI and IGF-1 (p ≤0.05). We observed similar associations between waist-to-hip ratio and these markers. Our finding of augmented IGF-1 among women with low body mass may have implications for understanding breast tumor heterogeneity in diverse populations and should be evaluated in larger prospective studies with cancer outcomes.

Dynamic Factorization in Large-Scale Optimization

DTIC Science & Technology

1994-01-01

and variable production charges, distribution via multiple modes, taxes, duties and duty draw- back, and inventory charges. See Harrison, Arntzen and...34 Capital allocation and project selection via decomposition:’ presented at CORS/TIMS/ORSA meeting. Vancouver. Be ( 1989). T.P. Harrison. B.C. Arntzen and