Wind velocity-change (gust rise) criteria for wind turbine design

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

Cliff, W.C.; Fichtl, G.H.

1978-07-01

A closed-form equation is derived for root mean square (rms) value of velocity change (gust rise) that occurs over the swept area of wind turbine rotor systems and an equation for rms value of velocity change that occurs at a single point in space. These formulas confirm the intuitive assumption that a large system will encounter a less severe environment than a small system when both are placed at the same location. Assuming a normal probability density function for the velocity differences, an equation is given for calculating the expected number of velocity differences that will occur in 1 hrmore » and will be larger than an arbitrary value. A formula is presented that gives the expected number of velocity differences larger than an arbitrary value that will be encountered during the design life of a wind turbine. In addition, a method for calculating the largest velocity difference expected during the life of a turbine and a formula for estimating the risk of exceeding a given velocity difference during the life of the structure are given. The equations presented are based upon general atmospheric boundary-layer conditions and do not include information regarding events such as tornados, hurricanes, etc.« less

Isolated intermediate-depth seismicity north of the Izu peninsula, Japan: implications for subduction of the Philippine Sea Plate

NASA Astrophysics Data System (ADS)

Nakajima, Junichi

2018-01-01

The subduction of the Philippine Sea (PHS) Plate toward the north of Izu peninsula, Japan, is of great interest because intraslab seismicity is absent where the buoyant Izu volcanic arc has been subducting over the past 15 Myr. This study analyzes 42 earthquakes in an isolated seismic cluster that occurred 100 km north of Izu peninsula at depths of 40-90 km and discusses seismogenesis in the context of plate subduction. We picked P- and S-wave arrival times of earthquakes to produce a complete hypocenter catalogue, carried out double-difference event relocations, and then determined focal mechanism solutions of 7 earthquakes from P-wave polarity data. Based on the focal mechanism solution, the largest earthquake (M3.1) is interpreted as a thrust earthquake along the upper surface of the PHS Plate. Locations of other earthquakes relative to the largest event suggest that most earthquakes occur within the subducting PHS Plate. Our results suggest that the PHS Plate north of Izu peninsula has temperatures low enough to facilitate thrust and intraslab earthquakes at depths of 60-90 km. Earthquakes are likely to occur where pore pressures are locally high, which weakens pre-existing faults. The presence of the intermediate-depth seismic cluster indicates the continuous subduction of the PHS Plate toward the north of Izu peninsula without any disruption.[Figure not available: see fulltext.

Stable Carbon Fractionation In Size Segregated Aerosol Particles Produced By Controlled Biomass Burning

NASA Astrophysics Data System (ADS)

Masalaite, Agne; Garbaras, Andrius; Garbariene, Inga; Ceburnis, Darius; Martuzevicius, Dainius; Puida, Egidijus; Kvietkus, Kestutis; Remeikis, Vidmantas

2014-05-01

Biomass burning is the largest source of primary fine fraction carbonaceous particles and the second largest source of trace gases in the global atmosphere with a strong effect not only on the regional scale but also in areas distant from the source . Many studies have often assumed no significant carbon isotope fractionation occurring between black carbon and the original vegetation during combustion. However, other studies suggested that stable carbon isotope ratios of char or BC may not reliably reflect carbon isotopic signatures of the source vegetation. Overall, the apparently conflicting results throughout the literature regarding the observed fractionation suggest that combustion conditions may be responsible for the observed effects. The purpose of the present study was to gather more quantitative information on carbonaceous aerosols produced in controlled biomass burning, thereby having a potential impact on interpreting ambient atmospheric observations. Seven different biomass fuel types were burned under controlled conditions to determine the effect of the biomass type on the emitted particulate matter mass and stable carbon isotope composition of bulk and size segregated particles. Size segregated aerosol particles were collected using the total suspended particle (TSP) sampler and a micro-orifice uniform deposit impactor (MOUDI). The results demonstrated that particle emissions were dominated by the submicron particles in all biomass types. However, significant differences in emissions of submicron particles and their dominant sizes were found between different biomass fuels. The largest negative fractionation was obtained for the wood pellet fuel type while the largest positive isotopic fractionation was observed during the buckwheat shells combustion. The carbon isotope composition of MOUDI samples compared very well with isotope composition of TSP samples indicating consistency of the results. The measurements of the stable carbon isotope ratio in size segregated aerosol particles suggested that combustion processes could strongly affect isotopic fractionation in aerosol particles of different sizes thereby potentially affecting an interpretation of ambient atmospheric observations.

Cellulose nanocrystals the next big nano-thing?

Treesearch

Michael T. Postek; Andras Vladar; John Dagata; Natalia Farkas; Bin Ming; Ronald Sabo; Theodore H. Wegner; James Beecher

2008-01-01

Biomass surrounds us from the smallest alga to the largest redwood tree. Even the largest trees owe their strength to a newly-appreciated class of nanomaterials known as cellulose nanocrystals (CNC). Cellulose, the world’s most abundant natural, renewable, biodegradable polymer, occurs as whisker like microfibrils that are biosynthesized and deposited in plant material...

Peak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA

USGS Publications Warehouse

Fenton, C.R.; Webb, R.H.; Cerling, T.E.

2006-01-01

The failure of a lava dam 165,000 yr ago produced the largest known flood on the Colorado River in Grand Canyon. The Hyaloclastite Dam was up to 366 m high, and geochemical evidence linked this structure to outburst-flood deposits that occurred for 32 km downstream. Using the Hyaloclastite outburst-flood deposits as paleostage indicators, we used dam-failure and unsteady flow modeling to estimate a peak discharge and flow hydrograph. Failure of the Hyaloclastite Dam released a maximum 11 ?? 109 m3 of water in 31 h. Peak discharges, estimated from uncertainty in channel geometry, dam height, and hydraulic characteristics, ranged from 2.3 to 5.3 ?? 105 m3 s-1 for the Hyaloclastite outburst flood. This discharge is an order of magnitude greater than the largest known discharge on the Colorado River (1.4 ?? 104 m3 s-1) and the largest peak discharge resulting from failure of a constructed dam in the USA (6.5 ?? 104 m3 s-1). Moreover, the Hyaloclastite outburst flood is the oldest documented Quaternary flood and one of the largest to have occurred in the continental USA. The peak discharge for this flood ranks in the top 30 floods (>105 m3 s-1) known worldwide and in the top ten largest floods in North America. ?? 2005 University of Washington. All rights reserved.

Peak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA

NASA Astrophysics Data System (ADS)

Fenton, Cassandra R.; Webb, Robert H.; Cerling, Thure E.

2006-03-01

The failure of a lava dam 165,000 yr ago produced the largest known flood on the Colorado River in Grand Canyon. The Hyaloclastite Dam was up to 366 m high, and geochemical evidence linked this structure to outburst-flood deposits that occurred for 32 km downstream. Using the Hyaloclastite outburst-flood deposits as paleostage indicators, we used dam-failure and unsteady flow modeling to estimate a peak discharge and flow hydrograph. Failure of the Hyaloclastite Dam released a maximum 11 × 10 9 m 3 of water in 31 h. Peak discharges, estimated from uncertainty in channel geometry, dam height, and hydraulic characteristics, ranged from 2.3 to 5.3 × 10 5 m 3 s -1 for the Hyaloclastite outburst flood. This discharge is an order of magnitude greater than the largest known discharge on the Colorado River (1.4 × 10 4 m 3 s -1) and the largest peak discharge resulting from failure of a constructed dam in the USA (6.5 × 10 4 m 3 s -1). Moreover, the Hyaloclastite outburst flood is the oldest documented Quaternary flood and one of the largest to have occurred in the continental USA. The peak discharge for this flood ranks in the top 30 floods (>10 5 m 3 s -1) known worldwide and in the top ten largest floods in North America.

Attribution of CO2 emissions from Brazilian deforestation to domestic and international drivers

NASA Astrophysics Data System (ADS)

Karstensen, J.; Peters, G.

2011-12-01

Efforts to address extensive deforestation to reduce climate change and save primary forests are taking place on a global scale. Whilst several studies have estimated the emissions occurring from deforestation in large rainforests, few studies have investigated the domestic and international drivers sustaining and increasing the deforestation rates. Brazil, having the largest rainforest in the world and one of the highest deforestation rates, is also currently one of the world's largest exporters of soybeans and beef. In this case study we establish the link between Brazilian deforestation and cattle and soybean production, and further attribute emissions to countries and economic sectors through export and import of Brazilian commodities. The emissions from deforestation can therefore be allocated to the countries and sectors consuming goods and services produced on deforested land in Brazil. A land-use change model and deforestation data is coupled with a carbon cycle model to create yearly emission estimates and different emission allocation schemes, depending on emission amortizations and discounting functions for past deforestation. We use an economic multi-regional input-output model (with 112 regions and 57 sectors) to distribute these emissions along agricultural trade routes, through domestic and international consumption in 2004. With our implementation we find that around 80 % of emissions from deforested land is due to cattle grazing, while agricultural transition effects suggests soy beans are responsible for about 20 % of the emissions occurring in 2004. Nearly tree quarters of the soy beans are consumed outside Brazil, of which China, Germany and France are the biggest consumers. Soy beans are consumed by a variety of sectors in the food industry. Brazil exports about 30 % of the cattle it produces, where Russia, USA and Germany are among the largest consumers. Cattle consumption mainly occurs in the meat sectors. In this study we estimate the CO2 emissions allocated to the consuming countries and economic sectors, to ultimately distribute responsibility and find the main drivers of Brazilian deforestation.

The Cataclysmic 1991 Eruption of Mount Pinatubo, Philippines

USGS Publications Warehouse

Newhall, Christopher G.; Hendley, James W.; Stauffer, Peter H.

1997-01-01

The second-largest volcanic eruption of this century, and by far the largest eruption to affect a densely populated area, occurred at Mount Pinatubo in the Philippines on June 15, 1991. The eruption produced high-speed avalanches of hot ash and gas, giant mudflows, and a cloud of volcanic ash hundreds of miles across. The impacts of the eruption continue to this day.

Environmental Assessment for the Replacement of Water Reservoirs

DTIC Science & Technology

2005-03-25

Intensive extraction of groundwater does not occur at Travis because of poor water- bearing subsurface geology. Intensive extraction SECTION 3.0...largest contiguous estuarine marsh and the largest wetland in the continental United States (CH2M HILL, 2001). Suisun Marsh drains into Grizzly and...and other support facilities. • Community (Commercial) – Uses include the exchange, commissary, banking, dining facilities, eating

Differential effects of dietary diversity and maternal characteristics on linear growth of children aged 6-59 months in sub-Saharan Africa: a multi-country analysis.

PubMed

Amugsi, Dickson A; Dimbuene, Zacharie T; Kimani-Murage, Elizabeth W; Mberu, Blessing; Ezeh, Alex C

2017-04-01

To investigate the differential effects of dietary diversity (DD) and maternal characteristics on child linear growth at different points of the conditional distribution of height-for-age Z-score (HAZ) in sub-Saharan Africa. Secondary analysis of data from nationally representative cross-sectional samples of singleton children aged 0-59 months, born to mothers aged 15-49 years. The outcome variable was child HAZ. Quantile regression was used to perform the multivariate analysis. The most recent Demographic and Health Surveys from Ghana, Nigeria, Kenya, Mozambique and Democratic Republic of Congo (DRC). The present analysis was restricted to children aged 6-59 months (n 31 604). DD was associated positively with HAZ in the first four quantiles (5th, 10th, 25th and 50th) and the highest quantile (90th) in Nigeria. The largest effect occurred at the very bottom (5th quantile) and the very top (90th quantile) of the conditional HAZ distribution. In DRC, DD was significantly and positively associated with HAZ in the two lower quantiles (5th, 10th). The largest effects of maternal education occurred at the lower end of the conditional HAZ distribution in Ghana, Nigeria and DRC. Maternal BMI and height also had positive effects on HAZ at different points of the conditional distribution of HAZ. Our analysis shows that the association between DD and maternal factors and HAZ differs along the conditional HAZ distribution. Intervention measures need to take into account the heterogeneous effect of the determinants of child nutritional status along the different percentiles of the HAZ distribution.

Characteristics of electron distributions observed during large amplitude whistler wave events in the magnetosphere

NASA Astrophysics Data System (ADS)

Wilson, L. B., III; Cattell, C. A.; Kellogg, P. J.; Goetz, K.; Wygant, J.; Breneman, A. W.; Kersten, K.

2010-12-01

We present a statistical study of the characteristics of electron distributions associated with large amplitude whistler waves inside the terrestrial magnetosphere using waveform capture data as an addition of the study by Kellogg et al., [2010b]. We identified three types of electron distributions observed simultaneously with the whistler waves including beam-like, beam/flattop, and anisotropic distributions. The whistlers exhibited different characteristics dependent upon the observed electron distributions. The majority of the waveforms observed in our study have f/fce ≤ 0.5 and are observed primarily in the radiation belts outside the plasmapause simultaneously with anisotropic electron distributions. We also present an example waveform capture of the largest magnetic field amplitude (≥ 8 nT pk-pk) whistler wave measured in the radiation belts. The majority of the largest amplitude whistlers occur during magnetically active periods (AE > 200 nT).

Rates of speciation and morphological evolution are correlated across the largest vertebrate radiation.

PubMed

Rabosky, Daniel L; Santini, Francesco; Eastman, Jonathan; Smith, Stephen A; Sidlauskas, Brian; Chang, Jonathan; Alfaro, Michael E

2013-01-01

Several evolutionary theories predict that rates of morphological change should be positively associated with the rate at which new species arise. For example, the theory of punctuated equilibrium proposes that phenotypic change typically occurs in rapid bursts associated with speciation events. However, recent phylogenetic studies have found little evidence linking these processes in nature. Here we demonstrate that rates of species diversification are highly correlated with the rate of body size evolution across the 30,000+ living species of ray-finned fishes that comprise the majority of vertebrate biological diversity. This coupling is a general feature of fish evolution and transcends vast differences in ecology and body-plan organization. Our results may reflect a widespread speciational mode of character change in living fishes. Alternatively, these findings are consistent with the hypothesis that phenotypic 'evolvability'-the capacity of organisms to evolve-shapes the dynamics of speciation through time at the largest phylogenetic scales.

On Examining the Transport and Transformation of Dissolved Organic Matter in The Albemarle-Pamlico Estuarine System, NC USA

NASA Astrophysics Data System (ADS)

Miller, R. L.; Buonassissi, C. J.; Brown, M. M.; Reed, R. E.

2016-02-01

The Albemarle-Pamlico Estuarine System (APES) in eastern North Carolina is the second largest estuary and largest lagoonal system in the United States. Variation in the amount of dissolved organic matter (DOM) delivered to the APES was examined for the Neuse and Tar/Pamlico River estuaries, two major components of the APES, using absorption spectra of Chromophoric Dissolved Organic Matter (CDOM). The quality of DOM and transformations that occur during down estuary transport were assessed using the spectral parameters SUVA254, SUVA350, S275-295, S350-400, and Sr calculated from CDOM spectra. We present results from several field campaigns that obtained surface samples during different stages of river discharge, including samples taken following Hurricane Irene (2011), and discuss the utility of using these newer optical indices of DOM quality for examining DOM dynamics in river dominated coastal waters.

Characteristics of Electron Distributions Observed During Large Amplitude Whistler Wave Events in the Magnetosphere

NASA Technical Reports Server (NTRS)

Wilson, Lynn B., III

2010-01-01

We present a statistical study of the characteristics of electron distributions associated with large amplitude whistler waves inside the terrestrial magnetosphere using waveform capture data as an addition of the study by Kellogg et al., [2010b]. We identified three types of electron distributions observed simultaneously with the whistler waves including beam-like, beam/flattop, and anisotropic distributions. The whistlers exhibited different characteristics dependent upon the observed electron distributions. The majority of the waveforms observed in our study have f/fce < or = 0.5 and are observed primarily in the radiation belts outside the plasmapause simultaneously with anisotropic electron distributions. We also present an example waveform capture of the largest magnetic field amplitude (> or = 8 nT pk-pk) whistler wave measured in the radiation belts. The majority of the largest amplitude whistlers occur during magnetically active periods (AE > 200 nT).

Rupture propagation behavior and the largest possible earthquake induced by fluid injection into deep reservoirs

NASA Astrophysics Data System (ADS)

Gischig, Valentin S.

2015-09-01

Earthquakes caused by fluid injection into deep underground reservoirs constitute an increasingly recognized risk to populations and infrastructure. Quantitative assessment of induced seismic hazard, however, requires estimating the maximum possible magnitude earthquake that may be induced during fluid injection. Here I seek constraints on an upper limit for the largest possible earthquake using source-physics simulations that consider rate-and-state friction and hydromechanical interaction along a straight homogeneous fault. Depending on the orientation of the pressurized fault in the ambient stress field, different rupture behaviors can occur: (1) uncontrolled rupture-front propagation beyond the pressure front or (2) rupture-front propagation arresting at the pressure front. In the first case, fault properties determine the earthquake magnitude, and the upper magnitude limit may be similar to natural earthquakes. In the second case, the maximum magnitude can be controlled by carefully designing and monitoring injection and thus restricting the pressurized fault area.

Large decadal-scale changes in uranium and bicarbonate in groundwater of the irrigated western U.S

USGS Publications Warehouse

Burow, Karen R.; Belitz, Kenneth; Dubrovsky, Neil M.; Jurgens, Bryant C.

2017-01-01

Samples collected about one decade apart from 1105 wells from across the U.S. were compiled to assess whether uranium concentrations in the arid climate are linked to changing bicarbonate concentrations in the irrigated western U.S. Uranium concentrations in groundwater were high in the arid climate in the western U.S, where uranium sources are abundant. Sixty-four wells (6%) were above the U.S. EPA MCL of 30 μg/L; all but one are in the arid west. Concentrations were low to non-detectable in the humid climate. Large uranium and bicarbonate increases (differences are greater than the uncertainty in concentrations) occur in 109 wells between decade 1 and decade 2. Similarly, large uranium and bicarbonate decreases occur in 76 wells between the two decades. Significantly more wells are concordant (uranium and bicarbonate are both going the same direction) than discordant (uranium and bicarbonate are going opposite directions) (p < 0.001; Chi-square test). The largest percent difference in uranium concentrations occur in wells where uranium is increasing and bicarbonate is also increasing. These large differences occur mostly in the arid climate. Results are consistent with the hypothesis that changing uranium concentrations are linked to changes in bicarbonate in irrigated areas of the western U.S.

Large Eddy Simulation and Reynolds-Averaged Navier-Stokes modeling of flow in a realistic pharyngeal airway model: an investigation of obstructive sleep apnea.

PubMed

Mihaescu, Mihai; Murugappan, Shanmugam; Kalra, Maninder; Khosla, Sid; Gutmark, Ephraim

2008-07-19

Computational fluid dynamics techniques employing primarily steady Reynolds-Averaged Navier-Stokes (RANS) methodology have been recently used to characterize the transitional/turbulent flow field in human airways. The use of RANS implies that flow phenomena are averaged over time, the flow dynamics not being captured. Further, RANS uses two-equation turbulence models that are not adequate for predicting anisotropic flows, flows with high streamline curvature, or flows where separation occurs. A more accurate approach for such flow situations that occur in the human airway is Large Eddy Simulation (LES). The paper considers flow modeling in a pharyngeal airway model reconstructed from cross-sectional magnetic resonance scans of a patient with obstructive sleep apnea. The airway model is characterized by a maximum narrowing at the site of retropalatal pharynx. Two flow-modeling strategies are employed: steady RANS and the LES approach. In the RANS modeling framework both k-epsilon and k-omega turbulence models are used. The paper discusses the differences between the airflow characteristics obtained from the RANS and LES calculations. The largest discrepancies were found in the axial velocity distributions downstream of the minimum cross-sectional area. This region is characterized by flow separation and large radial velocity gradients across the developed shear layers. The largest difference in static pressure distributions on the airway walls was found between the LES and the k-epsilon data at the site of maximum narrowing in the retropalatal pharynx.

Submarine landslides on the north continental slope of the South China Sea

NASA Astrophysics Data System (ADS)

Wang, Weiwei; Wang, Dawei; Wu, Shiguo; Völker, David; Zeng, Hongliu; Cai, Guanqiang; Li, Qingping

2018-02-01

Recent and paleo-submarine landslides are widely distributed within strata in deep-water areas along continental slopes, uplifts, and carbonate platforms on the north continental margin of the South China Sea (SCS). In this paper, high-resolution 3D seismic data and multibeam data based on seismic sedimentology and geomorphology are employed to assist in identifying submarine landslides. In addition, deposition models are proposed that are based on specific geological structures and features, and which illustrate the local stress field over entire submarine landslides in deep-water areas of the SCS. The SCS is one of the largest fluvial sediment sinks in enclosed or semi-enclosed marginal seas worldwide. It therefore provides a set of preconditions for the formation of submarine landslides, including rapid sediment accumulation, formation of gas hydrates, and fluid overpressure. A new concept involving temporal and spatial analyses is tested to construct a relationship between submarine landslides and different time scale trigger mechanisms, and three mechanisms are discussed in the context of spatial scale and temporal frequency: evolution of slope gradient and overpressure, global environmental changes, and tectonic events. Submarine landslides that are triggered by tectonic events are the largest but occur less frequently, while submarine landslides triggered by the combination of slope gradient and over-pressure evolution are the smallest but most frequently occurring events. In summary, analysis shows that the formation of submarine landslides is a complex process involving the operation of different factors on various time scales.

Particle Acceleration by Cme-driven Shock Waves

NASA Technical Reports Server (NTRS)

Reames, Donald V.

1999-01-01

In the largest solar energetic particle (SEP) events, acceleration occurs at shock waves driven out from the Sun by coronal mass ejections (CMEs). Peak particle intensities are a strong function of CME speed, although the intensities, spectra, and angular distributions of particles escaping the shock are highly modified by scattering on Alfven waves produced by the streaming particles themselves. Element abundances vary in complex ways because ions with different values of Q/A resonate with different parts of the wave spectrum, which varies with space and time. Just recently, we have begun to model these systematic variations theoretically and to explore other consequences of proton-generated waves.

Stable creeping fault segments can become destructive as a result of dynamic weakening.

PubMed

Noda, Hiroyuki; Lapusta, Nadia

2013-01-24

Faults in Earth's crust accommodate slow relative motion between tectonic plates through either similarly slow slip or fast, seismic-wave-producing rupture events perceived as earthquakes. These types of behaviour are often assumed to be separated in space and to occur on two different types of fault segment: one with stable, rate-strengthening friction and the other with rate-weakening friction that leads to stick-slip. The 2011 Tohoku-Oki earthquake with moment magnitude M(w) = 9.0 challenged such assumptions by accumulating its largest seismic slip in the area that had been assumed to be creeping. Here we propose a model in which stable, rate-strengthening behaviour at low slip rates is combined with coseismic weakening due to rapid shear heating of pore fluids, allowing unstable slip to occur in segments that can creep between events. The model parameters are based on laboratory measurements on samples from the fault of the M(w) 7.6 1999 Chi-Chi earthquake. The long-term slip behaviour of the model, which we examine using a unique numerical approach that includes all wave effects, reproduces and explains a number of both long-term and coseismic observations-some of them seemingly contradictory-about the faults at which the Tohoku-Oki and Chi-Chi earthquakes occurred, including there being more high-frequency radiation from areas of lower slip, the largest seismic slip in the Tohoku-Oki earthquake having occurred in a potentially creeping segment, the overall pattern of previous events in the area and the complexity of the Tohoku-Oki rupture. The implication that earthquake rupture may break through large portions of creeping segments, which are at present considered to be barriers, requires a re-evaluation of seismic hazard in many areas.

A statistical approach to determining energetic outer radiation belt electron precipitation fluxes

NASA Astrophysics Data System (ADS)

Simon Wedlund, Mea; Clilverd, Mark A.; Rodger, Craig J.; Cresswell-Moorcock, Kathy; Cobbett, Neil; Breen, Paul; Danskin, Donald; Spanswick, Emma; Rodriguez, Juan V.

2014-05-01

Subionospheric radio wave data from an Antarctic-Arctic Radiation-Belt (Dynamic) Deposition VLF Atmospheric Research Konsortia (AARDDVARK) receiver located in Churchill, Canada, is analyzed to determine the characteristics of electron precipitation into the atmosphere over the range 3 < L < 7. The study advances previous work by combining signals from two U.S. transmitters from 20 July to 20 August 2010, allowing error estimates of derived electron precipitation fluxes to be calculated, including the application of time-varying electron energy spectral gradients. Electron precipitation observations from the NOAA POES satellites and a ground-based riometer provide intercomparison and context for the AARDDVARK measurements. AARDDVARK radiowave propagation data showed responses suggesting energetic electron precipitation from the outer radiation belt starting 27 July 2010 and lasting ~20 days. The uncertainty in >30 keV precipitation flux determined by the AARDDVARK technique was found to be ±10%. Peak >30 keV precipitation fluxes of AARDDVARK-derived precipitation flux during the main and recovery phase of the largest geomagnetic storm, which started on 4 August 2010, were >105 el cm-2 s-1 sr-1. The largest fluxes observed by AARDDVARK occurred on the dayside and were delayed by several days from the start of the geomagnetic disturbance. During the main phase of the disturbances, nightside fluxes were dominant. Significant differences in flux estimates between POES, AARDDVARK, and the riometer were found after the main phase of the largest disturbance, with evidence provided to suggest that >700 keV electron precipitation was occurring. Currently the presence of such relativistic electron precipitation introduces some uncertainty in the analysis of AARDDVARK data, given the assumption of a power law electron precipitation spectrum.

Comparison of the USGS 2001 NLCD to the 2002 USDA Census of Agriculture for the Upper Midwest United States

USGS Publications Warehouse

Maxwell, S.K.; Wood, E.C.; Janus, A.

2008-01-01

The U.S. Geological Survey (USGS) 2001 National Land Cover Database (NLCD) was compared to the U.S. Department of Agriculture (USDA) 2002 Census of Agriculture. We compared areal estimates for cropland at the state and county level for 14 States in the Upper Midwest region of the United States. Absolute differences between the NLCD and Census cropland areal estimates at the state level ranged from 1.3% (Minnesota) to 37.0% (Wisconsin). The majority of counties (74.5%) had differences of less than 100 km2. 7.2% of the counties had differences of more than 200 km2. Regions where the largest areal differences occurred were in southern Illinois, North Dakota, South Dakota, and Wisconsin, and generally occurred in areas with the lowest proportions of cropland (i.e., dominated by forest or grassland). Before using the 2001 NLCD for agricultural applications, such as mapping of specific crop types, users should be aware of the potential for misclassification errors, especially where the proportion of cropland to other land cover types is fairly low.

Young Adult Women and the Pilgrimage of Motherhood

ERIC Educational Resources Information Center

Lipperini, Patricia T.

2016-01-01

Motherhood is a complex experience that can be transformative, offering women opportunities for personal enrichment and spiritual development. Because the largest incidence of births occurs to women in the Millennial or late Generation X generations, this complex, potentially transformative experience occurs at a critical time in young adult…

Sizing ocean giants: patterns of intraspecific size variation in marine megafauna

PubMed Central

Balk, Meghan A.; Benfield, Mark C.; Branch, Trevor A.; Chen, Catherine; Cosgrove, James; Dove, Alistair D.M.; Gaskins, Lindsay C.; Helm, Rebecca R.; Hochberg, Frederick G.; Lee, Frank B.; Marshall, Andrea; McMurray, Steven E.; Schanche, Caroline; Stone, Shane N.; Thaler, Andrew D.

2015-01-01

What are the greatest sizes that the largest marine megafauna obtain? This is a simple question with a difficult and complex answer. Many of the largest-sized species occur in the world’s oceans. For many of these, rarity, remoteness, and quite simply the logistics of measuring these giants has made obtaining accurate size measurements difficult. Inaccurate reports of maximum sizes run rampant through the scientific literature and popular media. Moreover, how intraspecific variation in the body sizes of these animals relates to sex, population structure, the environment, and interactions with humans remains underappreciated. Here, we review and analyze body size for 25 ocean giants ranging across the animal kingdom. For each taxon we document body size for the largest known marine species of several clades. We also analyze intraspecific variation and identify the largest known individuals for each species. Where data allows, we analyze spatial and temporal intraspecific size variation. We also provide allometric scaling equations between different size measurements as resources to other researchers. In some cases, the lack of data prevents us from fully examining these topics and instead we specifically highlight these deficiencies and the barriers that exist for data collection. Overall, we found considerable variability in intraspecific size distributions from strongly left- to strongly right-skewed. We provide several allometric equations that allow for estimation of total lengths and weights from more easily obtained measurements. In several cases, we also quantify considerable geographic variation and decreases in size likely attributed to humans. PMID:25649000

Stereo Particle Image Velocimetry Measurements of Transition Downstream of a Forward-Facing Step in a Swept-Wing Boundary Layer

NASA Technical Reports Server (NTRS)

Eppink, Jenna L.

2017-01-01

Stereo particle image velocimetry measurements were performed downstream of a forward-facing step in a stationary-crossflow dominated flow. Three different step heights were studied with the same leading-edge roughness configuration to determine the effect of the step on the evolution of the stationary-crossflow. Above the critical step height, which is approximately 68% of the boundary-layer thickness at the step, the step caused a significant increase in the growth of the stationary crossflow. For the largest step height studied (68%), premature transition occurred shortly downstream of the step. The stationary crossflow amplitude only reached approximately 7% of U(sub e) in this case, which suggests that transition does not occur via the high-frequency secondary instabilities typically associated with stationary crossflow transition. The next largest step of 60% delta still caused a significant impact on the growth of the stationary crossflow downstream of the step, but the amplitude eventually returned to that of the baseline case, and the transition front remained the same. The smallest step height (56%) only caused a small increase in the stationary crossflow amplitude and no change in the transition front. A final case was studied in which the roughness on the leading edge of the model was enhanced for the lowest step height case to determine the impact of the stationary crossflow amplitude on transition. The stationary crossflow amplitude was increased by approximately four times, which resulted in premature transition for this step height. However, some notable differences were observed in the behavior of the stationary crossflow mode, which indicate that the interaction mechanism which results in the increased growth of the stationary crossflow downstream of the step may be different in this case compared to the larger step heights.

Investigation of differences between field and laboratory pH measurements of national atmospheric deposition program/national trends network precipitation samples

USGS Publications Warehouse

Latysh, N.; Gordon, J.

2004-01-01

A study was undertaken to investigate differences between laboratory and field pH measurements for precipitation samples collected from 135 weekly precipitation-monitoring sites in the National Trends Network from 12/30/1986 to 12/28/1999. Differences in pH between field and laboratory measurements occurred for 96% of samples collected during this time period. Differences between the two measurements were evaluated for precipitation samples collected before and after January 1994, when modifications to sample-handling protocol and elimination of the contaminating bucket o-ring used in sample shipment occurred. Median hydrogen-ion and pH differences between field and laboratory measurements declined from 3.9 ??eq L-1 or 0.10 pH units before the 1994 protocol change to 1.4 ??eq L-1 or 0.04 pH units after the 1994 protocol change. Hydrogen-ion differences between field and laboratory measurements had a high correlation with the sample pH determined in the field. The largest pH differences between the two measurements occurred for high-pH samples (>5.6), typical of precipitation collected in Western United States; however low- pH samples (<5.0) displayed the highest variability in hydrogen-ion differences between field and laboratory analyses. Properly screened field pH measurements are a useful alternative to laboratory pH values for trend analysis, particularly before 1994 when laboratory pH values were influenced by sample-collection equipment.

Does canopy mean N concentration explain differences in light use efficiency in 14 eddy-covariance sites?

NASA Astrophysics Data System (ADS)

Peltoniemi, Mikko; Pulkkinen, Minna; Kolari, Pasi; Mäkelä, Annikki

2010-05-01

Production efficiency models aim at explaining variation of vegetation productivity with climatic input and information on vegetation cover often obtained from satellite observations. It has been acknowledged that different plant species differ in their potential to assimilate carbon dioxide per unit of PAR (i.e light use efficiency, LUE). Subsequently, some LUE-based models apply different LUE-coefficients for different plant functional types. Leaf N concentrations differ between plant species, and related differences in light saturated photosynthesis rate (A_max) have been detected. How much these differences affect the ecosystem production or LUE is more obscure. Canopies acclimate to prevailing environmental conditions, which causes variation e.g. in the proportion of leaves exposed to direct sunlight, leaf morphology, structure,orientation, and vertical N distibution. Furthermore, a fair proportion of photosynthesis occurs during cloudy days, in which case high A_max is unessential, and number of these days differs by location. We studied if canopy mean N concentration could explain differences in LUE derived for 14 forest sites using eddy-covariance measurements. The largest actual LUE was estimated for each site directly as an upper percentile of the ratio of Gross Primary Production (GPP) to absorbed PAR. Potential LUE for each site, on the other hand, was estimated by parameterising a LUE-based production efficiency model (Prelued), which accounts for daily changes in weather (temperature, VPD, PAR). In this model structure, the LUE-parameter for each site, can be interpreted as the potential LUE under optimal environmental conditions, i.e when the environment is not limiting production at all. Averages of the largest actual LUE and potential LUE were higher in deciduous sites than in conifer sites. Canopy mean N correlated weakly with both the largest actual and potential LUE, and the correlation was also significant in conifer subset in the former case. Mean growing season VPD was the only climatic variable which correlated significantly with the largest actual LUE; none of them correlated with potential LUE. Inclusion of nitrogen in the Prelued-model structure did not improve the goodness of fit of the model. According to our results LUE correlates with mean canopy N concentration. The correlation of mean VPD with the largest actual LUE can also be explained with the model accounting for daily variation in climate, as was made with Prelued-model for the potential LUE. Further studies utilising seasonal values of canopy N are called upon. *Acknowledgements: Eero Nikinmaa, Pertti Hari, Timo Vesala, Tuomas Laurila, Fredrik Lagergren, Meelis Mölder, Anders Lindroth, Thomas Grünwald, Christian Bernhofer, Denis Loustau, Paul Berbigier, Beverly Law, Alison Dunn, Steve Wofsy, Torbjörn Johansson, Torben Christensen, Terry Callaghan, Hans Verbeeck, Remko Duursma, Leonardo Montagnani, Dario Papale, Andreas Ibrom, Ebba Dellwik, Kim Pilegaard, Kentaro Takagi, Eva van Gorsel, Heather Keith, Sonia Wharton, Matthias Falk, Kya Tha Paw U, Matt Schroeder, Jon Lloyd

The U.S. Financial Crisis: The Global Dimension With Implications for U.S. Policy

DTIC Science & Technology

2008-11-18

financial crisis. Some of the largest and most venerable banks, investment houses, and insurance companies have either declared bankruptcy or have had to...of the largest and most venerable banks, investment houses, and insurance companies have either declared bankruptcy or have had to be rescued...and inadequate capital backing credit default swaps ( insurance against defaults and bankruptcy) have occurred. The second level of the crisis is

Rays as weapons.

PubMed

Vogel, H

2007-08-01

Ionizing radiation is being regarded as life threatening. Therefore, accidents in nuclear power plants are considered equal threatening as nuclear bomb explosions, and attacks with dirty bombs are thought as dangerous as nuclear weapon explosions. However, there are differences between a nuclear bomb explosion, the largest imaginable accident in a nuclear power plant, and an attack with a dirty bomb. It is intended to point them out. The processes are described, which damage in a nuclear bomb explosion, in the largest imaginable accident in a nuclear power plant, and in an attack with a dirty bomb. Their effects are compared with each other, i.e. explosion, heat, shock wave (blast), ionizing radiation, and fallout. In the center of the explosion of a nuclear bomb, the temperature rises to 100Mio degrees C, this induces damaging heat radiation and shock wave. In the largest imaginable accident in a nuclear power plant and in the conventional explosion of a dirty bomb, the temperature may rise up to 3000 degrees C, heat radiation and blast are limited to a short distance. In nuclear power plants, explosions due to oxyhydrogen gas or steam may occur. In nuclear explosions the dispersed radioactive material (fall out) consists mainly of isotopes with short half-life, in nuclear power plants and in dirty bomb attacks with longer half-life. The amount of fall out is comparable in nuclear bomb explosions with that in the largest imaginable accident in a nuclear power plant, it is smaller in attacks with dirty bombs. An explosion in a nuclear power plant even in the largest imaginable accident is not a nuclear explosion. In Hiroshima and Nagasaki, there were 200,000 victims nearly all by heat and blast, some 300 died by ionizing radiation. In Chernobyl, there have been less than 100 victims due to ionizing radiation up till now. A dirty bomb kills possibly with the explosion of conventional explosive, the dispersed radioactive material may damage individuals. The incorporation of irradiating substances may kill and be difficult to detect (Litvinenko). A new form of (government supported) terrorism/crime appears possible. The differences are important between a nuclear weapon explosion, the largest imaginable accident in a nuclear power plant, and an attack with a dirty bomb. Nuclear weapons kill by heat and blast; in the largest imaginable accident in a nuclear power plant, they are less strong and limited to the plant; an attack with a dirty bomb is as life threatening as an ("ordinary") bomb attack, dispersed radiating material may be a risk for individuals.

AcuteToxicological Responses of Fischer Rats to Naturally Occurring Asbestos Samples from the United States and Canada

EPA Science Inventory

The potential public health issues related to exposure to natural asbestos deposits (commonly termed naturally occurring asbestos, NO A) has gained the regulatory and media spotlight in recent years. Arguably the most well known example is Libby, Montana, the site of the largest ...

Earthquakes, September-October 1978

USGS Publications Warehouse

Person, W.J.

1979-01-01

The months of September and October were somewhat quiet seismically speaking. One major earthquake, magnitude (M) 7.7 occurred in Iran on September 16. In Germany, a magntidue 5.0 earthquake caused damage and considerable alarm to many people in parts of that country. In the United States, the largest earthquake occurred along the California-Nevada border region. 

Antecedents and consequences of workplace aggression in the allied health context.

PubMed

Demir, Defne; Rodwell, John; Flower, Rebecca L

2014-01-01

Workplace aggression research has typically focused on groups in the health care industry considered to be high risk (e.g., nursing); however, aggression also occurs among other health care professional groups, such as those in allied health. This study aimed to investigate the antecedents and consequences of workplace aggression among allied health professionals. Allied health professionals working for an Australian health care organization were surveyed, with 134 (49%) responding. The largest group of allied health professionals surveyed were social workers (49%). Job demands, job control, and social support were linked to different types of aggression. Different sources of aggression were linked to various employee outcomes. The importance of considering stressors surrounding employee work conditions is highlighted.

Giant Upper Cretaceous oysters from the Gulf coast and Caribbean

USGS Publications Warehouse

Sohl, Norman F.; Kauffman, Erle G.

1964-01-01

Two unusually massive ostreid species, representing the largest and youngest Mesozoic members of their respective lineages, occur in Upper Cretaceous sediment of the gulf coast and Caribbean areas. Their characteristics and significance, as well as the morphologic terminology of ostreids in general, are discussed. Crassostrea cusseta Sohl and Kauffman n. sp. is the largest known ostreid from Mesozoic rocks of North America; it occurs sporadically in the Cusseta Sand and rarely in the Blufftown Formation of the Chattahoochee River region in Georgia and Alabama. It is especially notable in that it lacks a detectable posterior adductor muscle scar on large adult shells. C. cusseta is the terminal Cretaceous member of the C. soleniscus lineage in gulf coast sediments; the lineage continues, however, with little basic modification, throughout the Cenozoic, being represented in the Eocene by C. gigantissima (Finch) and probably, in modern times, by C. virginica (Gmelin). The C. soleniscus lineage is the first typically modern crassostreid group recognized in the Mesozoic. Arctostrea aguilerae (Böse) occurs in Late Campanian and Early Maestrichtian sediments of Alabama, Mississippi, Texas(?), Mexico, and Cuba. The mature shell of this species is larger and more massive than that of any other known arctostreid. Arctostrea is well represented throughout the Upper Jurassic and Cretaceous of Europe, but in North America, despite the great numbers and diversity of Cretaceous oysters, only A. aguilerae and the Albian form A. carinata are known. The presence of A. aquilerae in both the Caribbean and gulf coast faunas is exceptional, as the Late Cretaceous faunas of these provinces are generally distinct and originated in different faunal realms.

Nonlinearity in rock - Evidence from earth tides

NASA Technical Reports Server (NTRS)

Agnew, D. C.

1981-01-01

The earth is sinusoidally stressed by tidal forces; if the stress-strain relation for rock is nonlinear, energy should appear in an earth tide record at frequencies which are multiples of those of the larger tidal lines. An examination of the signals to be expected for different nonlinear deformation laws shows that for a nonlinear response without dissipation, the largest anomalous signal should occur at twice the forcing frequency, whereas for nonlinear laws involving dissipation (cusped hysteresis loops) the anomalous signal will be greatest at three times this frequency. The size of the signal in the dissipative case depends on the amount by which dissipation affects the particular response being measured. For measurements of strain tides this depends on whether dissipation is assumed to be present throughout the earth or localized around the point of measurement. An analysis of 5.7 years of strain tide records from Pinon Flat, California, shows a small signal at twice the frequency of the largest (M2) tide.

Seismicity associated with quiescent-explosive transitions at dome forming eruptions: The July 2008 Vulcanian Explosion of Soufrière Hills Volcano, Montserrat

NASA Astrophysics Data System (ADS)

Rodgers, Mel; Smith, Patrick; Mather, Tamsin A.; Pyle, David M.

2017-04-01

During long-lived dome-forming eruptions volcanoes often transition between quiescent, effusive, and explosive behaviour. Soufrière Hills Volcano (SHV), Montserrat, has been erupting since 1995 and has repeatedly transitioned between these different phases of activity. At SHV many of the largest explosions have occurred either during periods of dome growth, or as major dome collapse events at the end of extrusion phases. However, on the 29th July 2008 a vulcanian explosion marked the transition from a quiescent phase (Pause 3) to explosion and then extrusion. This was one of the largest explosions by volume and the largest to occur outside a period of lava extrusion. The eruption was preceded by one of the most intense seismic swarms ever recorded at SHV. In this study we analysed precursory seismic data to investigate the subsurface volcanic processes that culminated in this eruption. We used spectral and multiplet analysis techniques, and applied a simple parameterization approach to relate monitoring observations (seismic, SO2, visual) to subsurface interpretations. These techniques would be available to most volcano observatories. Our study suggests that an initial VT swarm, coincident with ash-venting events, can be triggered by ascent of decoupled gas ahead of rising magma. A subsequent large LF swarm shows a coincident decrease in spectral content that we interpret as magma ascent through the upper conduit system. An ash-venting event on 27 July (a few hours before peak event rate) may have triggered rapid microlite growth. We observe an increase in the spectral content of the LF swarm that is concurrent with a decrease in event rates, suggesting pressurization of the magmatic system due to inhibited magmatic outgassing. Our results suggest that pressurization of the magmatic system may have occurred in the final 24 h before the vulcanian explosion. We also observe LP and Hybrid events within the same multiplet, suggesting that these events have very similar source processes and should be considered part of the same classification at SHV. Our study demonstrates the potential for using spectral and multiplet analysis to understand subsurface magmatic processes and for investigating the transition between quiescence and eruption.

Listening to the 2011 magnitude 9.0 Tohoku-Oki, Japan, earthquake

USGS Publications Warehouse

Peng, Zhigang; Aiken, Chastity; Kilb, Debi; Shelly, David R.; Enescu, Bogdan

2012-01-01

The magnitude 9.0 Tohoku-Oki, Japan, earthquake on 11 March 2011 is the largest earthquake to date in Japan’s modern history and is ranked as the fourth largest earthquake in the world since 1900. This earthquake occurred within the northeast Japan subduction zone (Figure 1), where the Pacific plate is subducting beneath the Okhotsk plate at rate of ∼8–9 cm/yr (DeMets et al. 2010). This type of extremely large earthquake within a subduction zone is generally termed a “megathrust” earthquake. Strong shaking from this magnitude 9 earthquake engulfed the entire Japanese Islands, reaching a maximum acceleration ∼3 times that of gravity (3 g). Two days prior to the main event, a foreshock sequence occurred, including one earthquake of magnitude 7.2. Following the main event, numerous aftershocks occurred around the main slip region; the largest of these was magnitude 7.9. The entire foreshocks-mainshock-aftershocks sequence was well recorded by thousands of sensitive seismometers and geodetic instruments across Japan, resulting in the best-recorded megathrust earthquake in history. This devastating earthquake resulted in significant damage and high death tolls caused primarily by the associated large tsunami. This tsunami reached heights of more than 30 m, and inundation propagated inland more than 5 km from the Pacific coast, which also caused a nuclear crisis that is still affecting people’s lives in certain regions of Japan.

Small volcanic edifices and volcanism in the plains of Venus

NASA Technical Reports Server (NTRS)

Guest, John E.; Bulmer, Mark H.; Aubele, Jayne; Beratan, Kathi; Greeley, Ronald; Head, James W.; Michaels, Gregory; Weitz, Catherine; Wiles, Charles

1992-01-01

The different types of eruption that have occurred over time in the Venusian plains are considered. The most extensive volcanic units consist of flood lavas, the largest of which have volumes of the order of thousands of cubic kilometers. They are inferred to have erupted at high effusion rates, and they exhibit a range of radar backscatter characteristics indicating different surface textures and ages. Small edifices on the plains occur mainly in clusters associated with fracture belts. The majority are shield volcanos that may be up to a few tens of kilometers across but are generally 10 km or less in diameter. Volcanic domes have diameters up to several tens of kilometers and volumes of the order of 100 cu cm. These are interpreted as being constructed of lava erupted with a relatively high effective viscosity and thus possibly composed of more silicic lava. For many domes, the flanks were unstable during and after eruption and experienced gravity sliding that produced steep scalloped outer margins.

Fault Rupture Model of the 2016 Gyeongju, South Korea, Earthquake and Its Implication for the Underground Fault System

NASA Astrophysics Data System (ADS)

Uchide, Takahiko; Song, Seok Goo

2018-03-01

The 2016 Gyeongju earthquake (ML 5.8) was the largest instrumentally recorded inland event in South Korea. It occurred in the southeast of the Korean Peninsula and was preceded by a large ML 5.1 foreshock. The aftershock seismicity data indicate that these earthquakes occurred on two closely collocated parallel faults that are oblique to the surface trace of the Yangsan fault. We investigate the rupture properties of these earthquakes using finite-fault slip inversion analyses. The obtained models indicate that the ruptures propagated NNE-ward and SSW-ward for the main shock and the large foreshock, respectively. This indicates that these earthquakes occurred on right-step faults and were initiated around a fault jog. The stress drops were up to 62 and 43 MPa for the main shock and the largest foreshock, respectively. These high stress drops imply high strength excess, which may be overcome by the stress concentration around the fault jog.

Patterns of growth dominance in thinned yellow-poplar stands in the southern Appalachian Mountains, USA

Treesearch

Tara L. Keyser

2012-01-01

Growth dominance provides a quantitative description of the relative contribution of individual trees to stand growth. Positive dominance occurs when the largest individuals account for a greater proportion of growth period increment than total biomass. Conversely, negative dominance occurs when the smallest trees account for a greater proportion of the growth period...

IMPROVIDING SUSTAINABILITY IN METALLIC MATERIALS THROUGH REDUCTION OF WASTES DISCARDED TO THE ENVIRONMENT BY RECOVERY AND REUSE IN EXTRACTION AND FABRICATION INDUSTRIES

EPA Science Inventory

Designed to chronicle the pollution problem occurring at one of the world's largest Superfund sites and to address the potential of the application of the approach of the recovery of metal resources occurring in the acid mine drainage causing the pollution problem. Acid mine drai...

Mechanical properties of multilayered films using different nanoindenters.

PubMed

Fang, Te-Hua; Wang, Tong Hong; Wu, Jia-Hung

2010-07-01

The effects of interface, contact hardness, deformation, and adhesion of Al/Ni multilayered films under nanoindentation were investigated using molecular dynamics (MD) simulations. The results show that the indentation force of the sphere indenter is the largest among nanoindentations using sphere, cone, Vickers, or Berkovich type indenters at the same penetration depth. Force increasing, relaxation and adhesion took place during loading, holding depth and unloading, respectively. The interface occurred along the {111} (110) slip systems and the maximum width of the glide bands was about 1 nm. The reaction force and plastic energy of the indented films are also discussed.

STREPTOCOCCI OCCURRING IN SOUR MILK

PubMed Central

Jones, F. S.

1921-01-01

A well defined group of rod-like and coccoid organisms arranged in pairs and chains has been encountered in sour milk. The group comprises at least three species; the largest number ferment dextrose, lactose, maltose, mannitol, and salicin, and fail to ferment saccharose, raffinose, and inulin. A smaller number ferment saccharose in addition to dextrose, lactose, maltose, mannitol, and salicin. A few fail to attack mannitol. All three types grow luxuriantly at room temperature, coagulate milk, reduce litmus, and produce large amounts of acid in fermented bouillon containing dextrose. Specific morphological and cultural differences exist between the lactic acid streptococci and those associated with mastitis and those occurring in the udder. The lactic acid organisms outgrow the udder streptococci in the milk-souring process. When both types are implanted in sterile milk the udder type soon disappears. PMID:19868477

Multiscale spatial and small-scale temporal variation in the composition of Riverine fish communities.

PubMed

Growns, Ivor; Astles, Karen; Gehrke, Peter

2006-03-01

We studied the multiscale (sites, river reaches and rivers) and short-term temporal (monthly) variability in a freshwater fish assemblage. We found that small-scale spatial variation and short-term temporal variability significantly influenced fish community structure in the Macquarie and Namoi Rivers. However, larger scale spatial differences between rivers were the largest source of variation in the data. The interaction between temporal change and spatial variation in fish community structure, whilst statistically significant, was smaller than the variation between rivers. This suggests that although the fish communities within each river changed between sampling occasions, the underlying differences between rivers were maintained. In contrast, the strongest interaction between temporal and spatial effects occurred at the smallest spatial scale, at the level of individual sites. This means whilst the composition of the fish assemblage at a given site may fluctuate, the magnitude of these changes is unlikely to affect larger scale differences between reaches within rivers or between rivers. These results suggest that sampling at any time within a single season will be sufficient to show spatial differences that occur over large spatial scales, such as comparisons between rivers or between biogeographical regions.

Initial Breakdown Pulse Parameters in Intracloud and Cloud-to-Ground Lightning Flashes

NASA Astrophysics Data System (ADS)

Smith, E. M.; Marshall, T. C.; Karunarathne, S.; Siedlecki, R.; Stolzenburg, M.

2018-02-01

This study analyzes the largest initial breakdown (IB) pulse in flashes from four storms in Florida; data from three sensor arrays are used. The range-normalized, zero-to-peak amplitude of the largest IB pulse was determined along with its altitude, duration, and timing within each flash. Appropriate data were available for 40 intracloud (IC) and 32 cloud-to-ground (CG) flashes. Histograms of amplitude of the largest IB pulse by flash type were similar, with mean (median) values of 1.49 (1.05) V/m for IC flashes and -1.35 (-0.87) V/m for CG flashes. The largest IB pulse in 30 IC flashes showed a weak inverse relation between pulse amplitude and altitude. Amplitude of the largest IB pulse for 25 CG flashes showed no altitude correlation. Duration of the largest IB pulse in ICs averaged twice as long as in CGs (96 μs versus 46 μs), and all of the CG durations were <100 μs. Among the ICs, there is a positive relation between largest IB pulse duration and amplitude; the linear correlation coefficient is 0.385 with outliers excluded. The largest IB pulse in IC flashes typically occurred at a longer time after the first IB pulse (average 4.1 ms) than was the case in CG flashes (average 0.6 ms). In both flash types, the largest IB pulse was the first IB pulse in about 30% of the cases. In one storm all 42 IC flashes with triggered data had IB pulses.

Initial Breakdown Pulse Amplitudes in Intracloud and Cloud-to-Ground Lightning Flashes

NASA Astrophysics Data System (ADS)

Marshall, T. C.; Smith, E. M.; Stolzenburg, M.; Karunarathne, S.; Siedlecki, R. D., II

2017-12-01

This study analyzes the largest initial breakdown (IB) pulse in flashes from three storms in Florida. The study was motivated in part by the possibility that IB pulses of IC flashes may cause of terrestrial gamma-ray flashes (TGFs). The range-normalized, zero-to-peak amplitude of the largest IB pulse within each flash was determined along with its altitude, duration, and occurrence time in the flash. Appropriate data were available for 40 intracloud (IC) and 32 cloud-to-ground (CG) flashes. Histograms of the magnitude of the largest IB pulse amplitude by flash type were similar, with mean (median) values of 1.49 (1.05) V/m for IC flashes and -1.35 (-0.87) V/m for CG flashes. The mean amplitude of the largest IC IB pulses are substantially smaller (roughly an order of magnitude smaller) than the few known pulse amplitudes of TGF events and TGF candidate events. The largest IB pulse in 30 IC flashes showed a weak inverse relation between pulse amplitude and altitude. Amplitude of the largest IB pulse for 25 CG flashes showed no altitude correlation. Duration of the largest IB pulse in ICs averaged twice as long as in CGs (96 μs versus 46 μs); all of the CG durations were <100 μs. Among the ICs, there is a positive relation between largest IB pulse duration and amplitude; the linear correlation coefficient is 0.385 with outliers excluded. The largest IB pulse in IC flashes typically occurred at a longer time after the first IB pulse (average 4.1 ms) than was the case in CG flashes (average 0.6 ms). In both flash types, the largest IB pulse was the first IB pulse in about 30% of the cases.

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

Klein, Fred W.

A significant seismic hazard exists in south Hawaii from large tectonic earthquakes that can reach magnitude 8 and intensity XII. This paper quantifies the hazard by estimating the horizontal peak ground acceleration (PGA) in south Hawaii which occurs with a 90% probability of not being exceeded during exposure times from 10 to 250 years. The largest earthquakes occur beneath active, unbuttressed and mobile flanks of volcanoes in their shield building stage.

Remote Triggering in the Koyna-Warna Reservoir-Induced Seismic Zone, Western India

NASA Astrophysics Data System (ADS)

Bansal, Abhey Ram; Rao, N. Purnachandra; Peng, Zhigang; Shashidhar, D.; Meng, Xiaofeng

2018-03-01

Dynamic triggering following large distant earthquakes has been observed in many regions globally. In this study, we present evidence for remote dynamic triggering in the Koyna-Warna region of Western India, which is known to be a premier site of reservoir-induced seismicity. Using data from a closely spaced broadband network of 11 stations operated in the region since 2005, we conduct a systematic search for dynamic triggering following 20 large distant earthquakes with dynamic stresses of at least 1 kPa in the region. We find that the only positive cases of dynamic triggering occurred during 11 April 2012, Mw8.6 Indian Ocean earthquake and its largest aftershock of Mw8.2. In the first case, microearthquakes started to occur in the first few cycles of the Love waves, and the largest event of magnitude 3.3 occurred during the first few cycles of the Rayleigh waves. The increase of microseismicity lasted for up to five days, including a magnitude 4.8 event occurred approximately three days later. Our results suggest that the Koyna-Warna region is stress sensitive and susceptible for remote dynamic triggering, although the apparent triggering threshold appears to be slightly higher than other regions.

Seismic hazard maps of Mexico, the Caribbean, and Central and South America

USGS Publications Warehouse

Tanner, J.G.; Shedlock, K.M.

2004-01-01

The growth of megacities in seismically active regions around the world often includes the construction of seismically unsafe buildings and infrastructures due to an insufficient knowledge of existing seismic hazard and/or economic constraints. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. We have produced a suite of seismic hazard estimates for Mexico, the Caribbean, and Central and South America. One of the preliminary maps in this suite served as the basis for the Caribbean and Central and South America portion of the Global Seismic Hazard Map (GSHM) published in 1999, which depicted peak ground acceleration (pga) with a 10% chance of exceedance in 50 years for rock sites. Herein we present maps depicting pga and 0.2 and 1.0 s spectral accelerations (SA) with 50%, 10%, and 2% chances of exceedance in 50 years for rock sites. The seismicity catalog used in the generation of these maps adds 3 more years of data to those used to calculate the GSH Map. Different attenuation functions (consistent with those used to calculate the U.S. and Canadian maps) were used as well. These nine maps are designed to assist in global risk mitigation by providing a general seismic hazard framework and serving as a resource for any national or regional agency to help focus further detailed studies required for regional/local needs. The largest seismic hazard values in Mexico, the Caribbean, and Central and South America generally occur in areas that have been, or are likely to be, the sites of the largest plate boundary earthquakes. High hazard values occur in areas where shallow-to-intermediate seismicity occurs frequently. ?? 2004 Elsevier B.V. All rights reserved.

The largest forest fires in Portugal: the constraints of burned area size on the comprehension of fire severity.

PubMed

Tedim, Fantina; Remelgado, Ruben; Martins, João; Carvalho, Salete

2015-01-01

Portugal is a European country with highest forest fires density and burned area. Since beginning of official forest fires database in 1980, an increase in number of fires and burned area as well as appearance of large and catastrophic fires have characterized fire activity in Portugal. In 1980s, the largest fires were just a little bit over 10,000 ha. However, in the beginning of 21st century several fires occurred with a burned area over 20,000 ha. Some of these events can be classified as mega-fires due to their ecological and socioeconomic severity. The present study aimed to discuss the characterization of large forest fires trend, in order to understand if the largest fires that occurred in Portugal were exceptional events or evidences of a new trend, and the constraints of fire size to characterize fire effects because, usually, it is assumed that larger the fire higher the damages. Using Portuguese forest fire database and satellite imagery, the present study showed that the largest fires could be seen at the same time as exceptional events and as evidence of a new fire regime. It highlighted the importance of size and patterns of unburned patches within fire perimeter as well as heterogeneity of fire ecological severity, usually not included in fire regime description, which are critical to fire management and research. The findings of this research can be used in forest risk reduction and suppression planning.

Differential chromosomal organization between Saguinus midas and Saguinus bicolor with accumulation of differences the repetitive sequence DNA.

PubMed

Serfaty, Dayane Martins Barbosa; Carvalho, Natália Dayane Moura; Gross, Maria Claudia; Gordo, Marcelo; Schneider, Carlos Henrique

2017-10-01

Saguinus is the largest and most complex genus of the subfamily Callitrichinae, with 23 species distributed from the south of Central America to the north of South America with Saguinus midas having the largest geographical distribution while Saguinus bicolor has a very restricted one, affected by the population expansion in the state of Amazonas. Considering the phylogenetic proximity of the two species along with evidence on the existence of hybrids between them, as well as cytogenetic studies on Saguinus describing a conserved karyotypic macrostructure, we carried out a physical mapping of DNA repeated sequences in the mitotic chromosome of both species, since these sequences are less susceptible to evolutionary pressure and possibly perform an important function in speciation. Both species presented 2n = 46 chromosomes; in S. midas, chromosome Y is the smallest. Multiple ribosomal sites occur in both species, but chromosome pairs three and four may be regarded as markers that differ the species when subjected to G banding and distribution of retroelement LINE 1, suggesting that it may be cytogenetic marker in which it can contribute to identification of first generation hybrids in contact zone. Saguinus bicolor also presented differences in the LINE 1 distribution pattern for sexual chromosome X in individuals from different urban fragments, probably due to geographical isolation. In this context, cytogenetic analyses reveal a differential genomic organization pattern between species S. midas and S. bicolor, in addition to indicating that individuals from different urban fragments have been accumulating differences because of the isolation between them.

The 12th June 2017 Mw = 6.3 Lesvos earthquake from detailed seismological observations

NASA Astrophysics Data System (ADS)

Papadimitriou, P.; Kassaras, I.; Kaviris, G.; Tselentis, G.-A.; Voulgaris, N.; Lekkas, E.; Chouliaras, G.; Evangelidis, C.; Pavlou, K.; Kapetanidis, V.; Karakonstantis, A.; Kazantzidou-Firtinidou, D.; Fountoulakis, I.; Millas, C.; Spingos, I.; Aspiotis, T.; Moumoulidou, A.; Skourtsos, E.; Antoniou, V.; Andreadakis, E.; Mavroulis, S.; Kleanthi, M.

2018-04-01

A major earthquake (Mwö=ö6.3) occurred on the 12th of June 2017 (12:28 GMT) offshore, south of the SE coast of Lesvos Island, at a depth of 13ökm, in an area characterized by normal faulting with an important strike-slip component in certain cases. Over 900 events of the sequence between 12 and 30 June 2017 were manually analyzed and located, employing an optimized local velocity model. Double-difference relocation revealed seven spatially separated groups of events, forming two linear branches, roughly aligned N130°E, compatible with the strike of known mapped faults along the southern coast of Lesvos Island. Spatiotemporal analysis indicated gradual migration of seismicity towards NW and SE from the margins of the main rupture, while a strong secondary sequence at a separate fault patch SE of the mainshock, oriented NW-SE, was triggered by the largest aftershock (Mwö=ö5.2) that occurred on 17 June. The focal mechanisms of the mainshock (φö=ö122°, δö=ö40° and λö=ö-83°) and of the major aftershocks were determined using regional moment tensor inversion. In most cases normal faulting was revealed with the fault plane oriented in a NW-SE direction, dipping SW, with the exception of the largest aftershock that was characterized by strike-slip faulting. Stress inversion revealed a complex stress field south of Lesvos, related both to normal, in an approximate E-W direction, and strike-slip faulting. All aftershocks outside the main rupture, where gradual seismicity migration was observed, are located within the positive lobes of static stress transfer determined by applying the Coulomb criterion for the mainshock. Stress loading on optimal faults under a strike-slip regime explains the occurrence of the largest aftershock and the seismicity that was triggered at the eastern patch of the rupture zone.

The Effect of Aerosols and Clouds on the Retrieval of Infrared Sea Surface Temperatures

NASA Technical Reports Server (NTRS)

Vazquez-Cuervo, Jorge; Armstrong, Edward M.; Harris, Andy

2004-01-01

Comparisons are performed between spatially averaged sea surface temperatures (ASST2) as derived from the second Along-Track Scanning Radiometer (ATSR-2) on board the second European Remote Sensing Satellite (ERS-2) and the NOAA-NASA Advanced Very High Resolution Radiometer (AVHRR) Oceans Pathfinder dataset (MPFSST). Difference maps, MPFSST 2 ASST2, along with the application of a simple statistical regression model to aerosol and cloud data from the Total Ozone Mapping Spectrometer ( TOMS), are used to examine the impact of possible aerosol and cloud contamination. Differences varied regionally, but the largest biases were seen off western Africa. Nighttime and daytime differences off western Africa were reduced from -0.5degrees to -0.2degreesC and from -0.1degrees to 0degreesC, respectively. Significant cloud flagging, based on the model, occurred in the Indian Ocean, the equatorial Pacific, and in the vicinity of the Gulf Stream. Comparisons of the MPFSST and the ASST2 with in situ data from the 2002 version of the World Oceanic Database (WOD02) off western Africa show larger mean differences for the MPFSST. The smallest mean differences occurred for nighttime ASST2 - WOD02 with a value of 0.0degrees +/- 0.4degreesC.

Age differences in genetic and environmental influences on weight and shape concerns.

PubMed

Klump, Kelly L; Burt, S Alexandra; Spanos, Alexia; McGue, Matt; Iacono, William G; Wade, Tracey D

2010-12-01

Previous research has shown important developmental shifts ingenetic and environmental influences for disordered eating. However, little research has examined age differences for weight/shape concerns, two key components of eating disorders. The goal of this study was to investigate these age differences in preadolescent, adolescent, young adult, and mid-adult twins. Participants included 2,618 female twins (ages of 10-41 years) from three large twin registries. Shape and weight concerns were assessed with the Eating Disorders Examination Questionnaire. Genetic influences were modest in preadolescent twins, but significant from early-adolescence through middle adulthood. Shared environmental factors showed the opposite pattern, with the largest shared environmental contributions occurring in the youngest age group. Nonshared environmental effects remained relatively constant across age. Findings highlight the importance of age differences in genetic and environmental influences. Possible mechanisms include gene x environment interactions and biological changes associated with key developmental stages. © 2009 by Wiley Periodicals, Inc.

Avoiding pitfalls in estimating heritability with the common options approach

PubMed Central

Danchin, Etienne; Wajnberg, Eric; Wagner, Richard H.

2014-01-01

In many circumstances, heritability estimates are subject to two potentially interacting pitfalls: the spatial and the regression to the mean (RTM) fallacies. The spatial fallacy occurs when the set of potential movement options differs among individuals according to where individuals depart. The RTM fallacy occurs when extreme measurements are followed by measurements that are closer to the mean. We simulated data from the largest published heritability study of a behavioural trait, colony size choice, to examine the operation of the two fallacies. We found that spurious heritabilities are generated under a wide range of conditions both in experimental and correlative estimates of heritability. Classically designed cross-foster experiments can actually increase the frequency of spurious heritabilities. Simulations showed that experiments providing all individuals with the identical set of options, such as by fostering all offspring in the same breeding location, are immune to the two pitfalls. PMID:24865284

Far-field pressurization likely caused one of the largest injection induced earthquakes by reactivating a large pre-existing basement fault structure

USGS Publications Warehouse

Yeck, William; Weingarten, Matthew; Benz, Harley M.; McNamara, Daniel E.; Bergman, E.; Herrmann, R.B; Rubinstein, Justin L.; Earle, Paul

2016-01-01

The Mw 5.1 Fairview, Oklahoma, earthquake on 13 February 2016 and its associated seismicity produced the largest moment release in the central and eastern United States since the 2011 Mw 5.7 Prague, Oklahoma, earthquake sequence and is one of the largest earthquakes potentially linked to wastewater injection. This energetic sequence has produced five earthquakes with Mw 4.4 or larger. Almost all of these earthquakes occur in Precambrian basement on a partially unmapped 14 km long fault. Regional injection into the Arbuckle Group increased approximately sevenfold in the 36 months prior to the start of the sequence (January 2015). We suggest far-field pressurization from clustered, high-rate wells greater than 12 km from this sequence induced these earthquakes. As compared to the Fairview sequence, seismicity is diffuse near high-rate wells, where pressure changes are expected to be largest. This points to the critical role that preexisting faults play in the occurrence of large induced earthquakes.

Shortleaf pine seed production in natural stands in the Ouachita and Ozark mountains

Treesearch

Michael G. Shelton; Robert F. Wittwer

1996-01-01

Seed production of shortleaf pine (Pinus echinata Mill.) was monitored from 1965 to 1974 to determine the periodicity qf seed crops in both woods-run stands and seed-production areas. One bumper and two good seed crops occurred during the 9-yr period. The two largest crops occurred in successive years, then seed production was low for 4 yr before...

Angular momentum and torques in a simulation of the atmosphere's response to the 1982-83 El Nino

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

Ponte, R.M.; Rosen, R.D.; Boer, G.J.

Anomalies in the angular momentum of the atmosphere (M) during the 1982-83 El Nino event and the torques responsible for these anomalies are investigated using output from the Canadian Climate Centre general circulation model. Model values of M during the year of the event are generally larger than those for the model climatology, thereby capturing the observed tendency toward higher values of M during El Nino. Differences exist between the model and observations in the timing and amplitude of the largest anomalies, but these differences may be due to natural variability and not necessarily directly associated with the 1982-83 Elmore » Nino conditions. In late September and October 1982, the model atmosphere acquires momentum more rapidly than usual, leading to the development of the largest deviations from mean conditions at the end of October. A secondary maximum in the departure from mean M values occurs in January 1983 and is related to a general strengthening of westerly momentum anomalies over the model's tropical and midlatitude regions. Both mountain and tangential stress torques are involved in this episode, but no particular mechanism or region dominates the anomalous exchange of momentum. 24 refs., 10 figs., 1 tab.« less

Differences Between Magnitudes and Health Impacts of BC ...

EPA Pesticide Factsheets

Recent assessments have analyzed the health impacts of PM2.5 from emissions from different locations and sectors using simplified or reduced-form air quality models. Here we present an alternative approach using the adjoint of the Community Multiscale Air Quality (CMAQ) model, which provides source–receptor relationships at highly resolved sectoral, spatial, and temporal scales. While damage resulting from anthropogenic emissions of BC is strongly correlated with population and premature death, we found little correlation between damage and emission magnitude, suggesting that controls on the largest emissions may not be the most efficient means of reducing damage resulting from anthropogenic BC emissions. Rather, the best proxy for locations with damaging BC emissions is locations where premature deaths occur. Onroad diesel and nonroad vehicle emissions are the largest contributors to premature deaths attributed to exposure to BC, while onroad gasoline emissions cause the highest deaths per amount emitted. Emissions in fall and winter contribute to more premature deaths (and more per amount emitted) than emissions in spring and summer. Overall, these results show the value of the high-resolution source attribution for determining the locations, seasons, and sectors for which BC emission controls have the most effective health benefits. The National Exposure Research Laboratory’s Atmospheric Modeling Division (AMAD) conducts research in support of EPA’s mis

Serum hormone concentrations and ovarian follicular wave emergence in Jilin sika deer (Cervus nippon hortulorum) after synchronization of estrous cycles.

PubMed

Chen, X M; Wei, H J; Yang, Y F; Xue, H L; Zhao, W G; Zhao, M

2015-02-01

The study was conducted to investigate the serum hormone concentrations and follicular dynamics present after synchronous treatment (CIDR) in female Jilin sika deer (n = 15) of estrous cycles. Blood samples were collected to analyze the FSH, LH, estradiol and progesterone during the estrous cycles. Manual transrectal ultrasonography examination was conducted at least thrice weekly to monitor the follicular wave. Ultrasonography showed that follicle development occurred in waves, and most estrous cycles in Jilin sika deer consist of one, two, or three waves. The largest follicles of the interwaves of two- and three-wave cycles were different (P < 0.05). The mean interovulatory interval was 15.0 ± 4.6 d. There was a surge in circulating FSH in two- and three-wave cycles. The emergence of the largest follicle was related to the peak of serum concentration of estradiol. Serum progesterone concentrations were not different between one- and three-wave cycles (P < 0.05). We concluded that FSH and estradiol concentration may have an important role in controlling follicular development, that the estrous cycle in Jilin sika deer is characterized by one, two, or three waves of follicular development after synchronization. Copyright © 2015. Published by Elsevier B.V.

[The journey of Legionella pneumophila from amoebae to macrophage. Reflections on the largest outbreak of legionnaire's disease].

PubMed

Segovia Hernández, Manuel

2005-01-01

Legionella, the causative agent of legionnaire's disease (LD), can survive and grow in amoebic cells. Free-living amoebae may play a role in the selection of virulence traits and in adaptation to survival in macrophages, and represent an important reservoir of Legionella. These amoebae may act as a Trojan horse bringing hidden bacteria within the human environments. The community outbreak of LD that occurred in Murcia in July 2001, the largest such outbreak ever reported, afforded an unusual opportunity to improve the knowledge of this disease.

Thermo-Oxidative Stability of Graphite/PMR-15 Composites: Effect of Fiber Surface Modification on Composite Shear Properties

NASA Technical Reports Server (NTRS)

Madhukar, Madhu S.; Bowles, Kenneth J.; Papadopolous, Demetrios S.

1994-01-01

Experiments were conducted to establish a correlation between the weight loss of a polyimide (PMR- 15) matrix and graphite fibers and the in-plane shear properties of their unidirectional composites subjected to different isothermal aging times up to 1000 hr at 316 C. The role of fiber surface treatment on the composite degradation during the thermo-oxidative aging was investigated by using A4 graphite fibers with three surface modifications: untreated (AU-4), surface treated (AS-4), and surface treated and sized with an epoxy-compatible sizing (AS-4G). The weight loss of the matrix fibers, and composites was determined during the aging. The effect of thermal aging was seen in all the fiber samples in terms of weight loss and reduction in fiber diameter. Calculated values of weight loss fluxes for different surfaces of rectangular unidirectional composite plates showed that the largest weight loss occurred at those cut surfaces where fibers were perpendicular to the surface. Consequently, the largest amount of damage was also noted on these cut surfaces. Optical observation of the neat matrix and composite plates subjected to different aging times revealed that the degradation (such as matrix microcracking and void growth) occurred in a thin surface layer near the specimen edges. The in-plane shear modulus of the composites was unaffected by the fiber surface treatment and the thermal aging. The shear strength of the composites with the untreated fibers was the lowest and it decreased with aging. A fracture surface examination of the composites with untreated fibers suggested that the weak interface allowed the oxidation reaction to proceed along the interface and thus expose the inner material to further oxidation. The results indicated that the fiber-matrix interface affected the composite degradation process during its thermal aging and that the the weak interface accelerated the composite degradation.

World's largest macroalgal bloom caused by expansion of seaweed aquaculture in China.

PubMed

Liu, Dongyan; Keesing, John K; Xing, Qianguo; Shi, Ping

2009-06-01

In late June 2008, just weeks before the opening of the Beijing Olympics, a massive green-tide occurred covering about 600km(2) along the coast of Qingdao, host city for Olympic sailing regatta. Coastal eutrophication was quickly attributed with the blame by the international media and some scientists. However, we explored an alternative hypothesis that the cause of the green-tide was due to the rapid expansion of Porphyra yezoensis aquaculture along the coastline over 180km away from Qingdao, and oceanographic conditions which favoured rapid growth of the bloom and contributed to transport of the bloom north into the Yellow Sea and then onshore northwest to Qingdao. At its peak offshore, the bloom covered 1200km(2) and affected 40,000km(2). This is the largest green-tide ever reported, the most extensive translocation of a green-tide and the first case of expansive seaweed aquaculture leading to a green-tide. Given similar oceanographic conditions to those that occurred in 2008, these green-tides may re-occur unless mitigation measures such as those proposed here are taken.

Evaporation of a Volatile Liquid Lens on the Surface of an Immiscible Liquid.

PubMed

Sun, Wei; Yang, Fuqian

2016-06-21

The evaporation behavior of toluene and hexane lenses on the surface of deionized (DI) water is studied. The toluene and hexane lenses during evaporation experience an advancing stage and a receding stage. There exists a significant difference of the evaporation behavior between the toluene lenses and the hexane lenses. The lifetime and largest diameter of both the toluene and hexane lenses increase with increasing the initial volume of the lenses. For the evaporation of the toluene lenses, the lifetime and largest diameter of the lenses decrease with increasing the temperature of DI water. The effect of the residual of the oil molecules on the evaporation of toluene lenses at a temperature of 21 °C is investigated via the evaporation of a series of consecutive toluene lenses being placed on the same position of the surface of DI water. The temporal evolution of the toluene lenses placed after the first toluene lens deviates significantly from that of the first toluene lens. Significant increase of the receding speed occurs at the dimensionless time in a range 0.7-0.8.

A Longitudinal Analysis of Cigarette Prices in Military Retail Outlets

PubMed Central

Haddock, Christopher Keith; Hyder, Melissa L.; Poston, Walker S. C.; Jahnke, Sara A.; Williams, Larry N.; Lando, Harry

2014-01-01

Objectives. We conducted a longitudinal assessment of tobacco pricing in military retail outlets, including trends within each service branch. Methods. We determined the price of a single pack of Marlboro Red cigarettes at military retail stores located in the continental United States, Alaska, and Hawaii and at their nearest Walmarts in spring 2011 and 2013 (n = 128 for pairs available at both assessments). Results. The average difference between cigarettes sold in military retail outlets and Walmarts decreased from 24.5% in 2011 to 12.5% in 2013. The decrease was partially attributable to significant price decreases at Walmarts. The largest increases in cigarette prices occurred on naval installations. Potential savings at stores on several installations remained substantial in 2013; the largest approached $6 per pack. Stores on 17 military installations decreased cigarette prices during the study period. Conclusions. Tobacco can be purchased in military retail stores at substantial savings over civilian stores. If tobacco pricing is to cease to be an incentive for use among personnel, a revised military tobacco pricing policy is needed. PMID:24524503

Observational evidence for turbulent effects on total suspended matter within the Pearl River plume

NASA Astrophysics Data System (ADS)

Chunhua, Qiu; Danyi, Su; Huabin, Mao; Jiaxue, Wu; Yongsheng, Cui; Dongxiao, Wang

2017-12-01

We observed the structure of the Pearl River plume and its turbulent characteristics, and investigated the turbulent effect on total suspended matter (TSM) within its ;far-field; region, based on in situ and satellite data collected in June 2015. A significant northeastward plume was created under southern monsoonal conditions. The in situ data provided the width, depth, and velocity of the plume, as inferred by salinity. Weaker turbulence occurred at the front surface position than in the plume zone. Stronger turbulence induced greater turbidity in the bottom boundary layer; however, the surface mixed layer differed. By estimating the turbidity budget, we found the lateral fluxes term was the largest term in the plume, turbulent fluxes comprised the second largest term, and the settling terms comprised the smallest term. We quantified the turbulent mechanisms and found that stronger river discharge induced greater TSM turbidity. Tidal and buoyancy fluxes had minor regulatory effects on TSM. Our observations suggest that TSM in the ;far field; region originated from the Pearl River and the coastal region.

Metamorphic reactions in the Chaunskij mesosiderite

NASA Astrophysics Data System (ADS)

Petaev, M. I.; Brearley, A. J.

1994-07-01

The Chaunskij meteorite, found in 1985, recently has been found to be the most highly metamorphosed, shock-modified, and metal-rich mesosiderite. It contains approximately 10 vol% mono- and polymineralic troilite-phosphate-silicate inclusions, micrometers to centimeters in size. Two dominant silicate lithologies have been found in the inclusions. The primary 'igneous' lithology, making up the largest inclusion studied, is generally a microophitic fine-grained aggregate of pyroxene, plagioclase, and minor silica, with scattered coarser-grained granoblastic spots enriched in silica and troilite. The secondary 'metamorphic' lithology occurs as separate small inclusions and as larger areas in intimate contact with the 'igneous' lithology, separated by highly irregular boundaries from each other, in the largest inclusion. In small inclusions the metamorphic lithology consists of a fine-grained hornfelsic to granoblastic aggregate of cordierite, orthopyroxene, quartz, and whitlockite with variable amounts of opaque minerals. In the largest inclusion the metamorphic lithology is a generally granoblastic to poikiloblastic aggregate of cordierite and quartz with minor amounts of other minerals. The Opx-Chr mineral thermometer and the Cord-Sp barometer have been applied to estimate the conditions of Chaunskij metamorphism. The data for 16 Opx-Chr pairs from different inclusions and lithologies correspond to a temperature of 590 +/- 30 C. The data for 9 Cord-Chr pairs from different inclusions correspond to a pressure of 6.0 +/- 0.2 kbar. While the composition of spinel in Chaunskij much richer in Cr than were the spinels used to calibrate Cord-Sp barometer the estimated pressure is consistent with the occurrence in the igneous lithology of two small pyroxene grains enriched in the CaAl2SiO6 molecule, coexisting with quartz and plagioclase. This mineral assemblage is unstable below approximately 5 kbar at 600 C.

FUEL EFFECTS ON COMBUSTION WITH EGR DILUTION IN SPARK IGNITED ENGINES

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

Szybist, James P

The use of EGR as a diluent allows operation with an overall stoichiometric charge composition, and the addition of cooled EGR results in well-understood thermodynamic benefits for improved fuel consumption. This study investigates the effect of fuel on the combustion and emission response of EGR dilution in spark ignited engines. A 2.0 L GM Ecotec LNF engine equipped with the production side-mounted direct injection (DI) fueling system is used in this study. Ethanol, isooctane and certified gasoline are investigated with EGR from 0% to the EGR dilution tolerance. Constant BMEP at 2000 rpm was operated with varying CA50 from 8more » CAD to 16 CAD aTDCf. The results show that ethanol gives the largest EGR tolerance at a given combustion phasing, engine load and speed. The improved EGR dilution tolerance with ethanol is attributed to a faster flame speed, which manifests itself as shorter combustion duration. Data shows that the combustion stability limit occurs at a critical combustion duration that is fuel independent. Due to different flame speeds, this critical combustion duration occurs at different EGR levels for the different fuels.« less

Overdose Deaths Involving Opioids, Cocaine, and Psychostimulants - United States, 2015-2016.

PubMed

Seth, Puja; Scholl, Lawrence; Rudd, Rose A; Bacon, Sarah

2018-03-30

During 1999‒2015, 568,699 persons died from drug overdoses in the United States.* Drug overdose deaths in the United States increased 11.4% from 2014 to 2015 resulting in 52,404 deaths in 2015, including 33,091 (63.1%) that involved an opioid. The largest rate increases from 2014 to 2015 occurred among deaths involving synthetic opioids other than methadone (synthetic opioids) (72.2%) (1). Because of demographic and geographic variations in overdose deaths involving different drugs (2,3), † CDC examined age-adjusted death rates for overdoses involving all opioids, opioid subcategories (i.e., prescription opioids, heroin, and synthetic opioids), § cocaine, and psychostimulants with abuse potential (psychostimulants) by demographics, urbanization levels, and in 31 states and the District of Columbia (DC). There were 63,632 drug overdose deaths in 2016; 42,249 (66.4%) involved an opioid. ¶ From 2015 to 2016, deaths increased across all drug categories examined. The largest overall rate increases occurred among deaths involving cocaine (52.4%) and synthetic opioids (100%), likely driven by illicitly manufactured fentanyl (IMF) (2,3). Increases were observed across demographics, urbanization levels, and states and DC. The opioid overdose epidemic in the United States continues to worsen. A multifaceted approach, with faster and more comprehensive surveillance, is needed to track emerging threats to prevent and respond to the overdose epidemic through naloxone availability, safe prescribing practices, harm-reduction services, linkage into treatment, and more collaboration between public health and public safety agencies.

SAFE HANDLING OF FOODS

EPA Science Inventory

Microbial food-borne illnesses pose a significant health problem in Japan. In 1996 the world's largest outbreak of Escherichia coli food illness occurred in Japan. Since then, new regulatory measures were established, including strict hygiene practices in meat and food processi...

The 1991 eruptions of Mount Pinatubo, Philippines

USGS Publications Warehouse

Wolfe, Edward W.

1992-01-01

Recognition of the volcanic unrest at Mount Pinatubo in the Philippines began when steam explosions occurred on April 2, 1991. The unrest culminated ten weeks later in the world's largest eruption in more than half a century. 

Legionnaires' Disease Outbreaks and Cooling Towers, New York City, New York, USA.

PubMed

Fitzhenry, Robert; Weiss, Don; Cimini, Dan; Balter, Sharon; Boyd, Christopher; Alleyne, Lisa; Stewart, Renee; McIntosh, Natasha; Econome, Andrea; Lin, Ying; Rubinstein, Inessa; Passaretti, Teresa; Kidney, Anna; Lapierre, Pascal; Kass, Daniel; Varma, Jay K

2017-11-01

The incidence of Legionnaires' disease in the United States has been increasing since 2000. Outbreaks and clusters are associated with decorative, recreational, domestic, and industrial water systems, with the largest outbreaks being caused by cooling towers. Since 2006, 6 community-associated Legionnaires' disease outbreaks have occurred in New York City, resulting in 213 cases and 18 deaths. Three outbreaks occurred in 2015, including the largest on record (138 cases). Three outbreaks were linked to cooling towers by molecular comparison of human and environmental Legionella isolates, and the sources for the other 3 outbreaks were undetermined. The evolution of investigation methods and lessons learned from these outbreaks prompted enactment of a new comprehensive law governing the operation and maintenance of New York City cooling towers. Ongoing surveillance and program evaluation will determine if enforcement of the new cooling tower law reduces Legionnaires' disease incidence in New York City.

Legionnaires’ Disease Outbreaks and Cooling Towers, New York City, New York, USA

PubMed Central

Fitzhenry, Robert; Cimini, Dan; Balter, Sharon; Boyd, Christopher; Alleyne, Lisa; Stewart, Renee; McIntosh, Natasha; Econome, Andrea; Lin, Ying; Rubinstein, Inessa; Passaretti, Teresa; Kidney, Anna; Lapierre, Pascal; Kass, Daniel; Varma, Jay K.

2017-01-01

The incidence of Legionnaires’ disease in the United States has been increasing since 2000. Outbreaks and clusters are associated with decorative, recreational, domestic, and industrial water systems, with the largest outbreaks being caused by cooling towers. Since 2006, 6 community-associated Legionnaires’ disease outbreaks have occurred in New York City, resulting in 213 cases and 18 deaths. Three outbreaks occurred in 2015, including the largest on record (138 cases). Three outbreaks were linked to cooling towers by molecular comparison of human and environmental Legionella isolates, and the sources for the other 3 outbreaks were undetermined. The evolution of investigation methods and lessons learned from these outbreaks prompted enactment of a new comprehensive law governing the operation and maintenance of New York City cooling towers. Ongoing surveillance and program evaluation will determine if enforcement of the new cooling tower law reduces Legionnaires’ disease incidence in New York City. PMID:29049017

Characterization of increased persistence and intensity of precipitation in the northeastern United States

NASA Astrophysics Data System (ADS)

Guilbert, Justin; Betts, Alan K.; Rizzo, Donna M.; Beckage, Brian; Bomblies, Arne

2015-03-01

We present evidence of increasing persistence in daily precipitation in the northeastern United States that suggests that global circulation changes are affecting regional precipitation patterns. Meteorological data from 222 stations in 10 northeastern states are analyzed using Markov chain parameter estimates to demonstrate that a significant mode of precipitation variability is the persistence of precipitation events. We find that the largest region-wide trend in wet persistence (i.e., the probability of precipitation in 1 day and given precipitation in the preceding day) occurs in June (+0.9% probability per decade over all stations). We also find that the study region is experiencing an increase in the magnitude of high-intensity precipitation events. The largest increases in the 95th percentile of daily precipitation occurred in April with a trend of +0.7 mm/d/decade. We discuss the implications of the observed precipitation signals for watershed hydrology and flood risk.

The characteristics on spatiotemporal variations of summer heatwaves in China

NASA Astrophysics Data System (ADS)

Qixiang, C.; Wang, L.; Wu, S., II; Li, Y.

2016-12-01

Summer heatwaves in China have impacts on forestry, agriculture resource, infrastructure, and heat -related illness and mortality. Based on daily air temperature and relative humidity from the Chinese Meteorological Data Sharing Service System, the spatial distribution and trends of the intensity, duration, and frequency of heatwaves in China during 1960-2015 were analyzed. Considering climatic variability, we defined a heatwave as a spell of consecutive days with maximum temperatures exceeding the relative threshold (temperature percentile) .We also consider a indices combined hot days and tropical nights (CHT), and the humidity-corrected apparent temperature (AT) to analyze the health impacts of hot days in summer. This study shows that while the average frequency and duration of heatwaves has an increasing trend since 1990s, the North China Plain has a decreasing trend. This study also shows that the largest CHT values occur in southeast China, and the largest AT values occur in South China.

Comparison of trend analyses for Umkehr data using new and previous inversion algorithms

NASA Technical Reports Server (NTRS)

Reinsel, Gregory C.; Tam, Wing-Kuen; Ying, Lisa H.

1994-01-01

Ozone vertical profile Umkehr data for layers 3-9 obtained from 12 stations, using both previous and new inversion algorithms, were analyzed for trends. The trends estimated for the Umkehr data from the two algorithms were compared using two data periods, 1968-1991 and 1977-1991. Both nonseasonal and seasonal trend models were fitted. The overall annual trends are found to be significantly negative, of the order of -5% per decade, for layers 7 and 8 using both inversion algorithms. The largest negative trends occur in these layers under the new algorithm, whereas in the previous algorithm the most negative trend occurs in layer 9. The trend estimates, both annual and seasonal, are substantially different between the two algorithms mainly for layers 3, 4, and 9, where trends from the new algorithm data are about 2% per decade less negative, with less appreciable differences in layers 7 and 8. The trend results from the two data periods are similar, except for layer 3 where trends become more negative, by about -2% per decade, for 1977-1991.

Determining the precipitable water vapor with ground-based GPS and comparing its yearly variation to rainfall over Taiwan

NASA Astrophysics Data System (ADS)

Yeh, Ta-Kang; Hong, Jing-Shan; Wang, Chuan-Sheng; Chen, Chieh-Hung; Chen, Kwo-Hwa; Fong, Chin-Tzu

2016-06-01

Water vapor plays an important role in weather prediction. Thus, it would be helpful to use precipitable water vapor (PWV) data from Global Positioning System (GPS) signals to understand weather phenomena. Approximately 100 ground GPS stations that cooperate with approximately 500 ground weather stations were used in this study. The relationship between the PWV and rainfall was investigated by analyzing the amplitude and phase that resulted from harmonic analyses. The results indicated that the maximum PWV amplitudes were between 10.98 and 13.10 mm and always occurred at the end of July. The magnitudes of the PWV growth rate were between 0.65 and 0.81 mm/yr. These rates increased from 9.2% to 13.0% between 2006 and 2011. The largest peak PWV amplitude occurred in the Western region. However, the largest rainfall amplitude occurred in the Southern region. The presented peak rainfall time agreed with the peak PWV time in the Western, Southern, and Central Mountain regions. Although rainfall decreased with time in Taiwan, this decrease was not large. The greatest rainfall consistently occurred during the months in which typhoons occurred, and the greatest PWV values occurred at the end of July. Although the end of July had the greatest monthly average PWV values, the rainfall magnitude during this period was smaller than that during the typhoons, which only occurred for a few days; the PWV also increased during typhoons. Because this effect was short-term, it did not significantly contribute to the PWV monthly average.

Human cortical responses to slow and fast binaural beats reveal multiple mechanisms of binaural hearing.

PubMed

Ross, Bernhard; Miyazaki, Takahiro; Thompson, Jessica; Jamali, Shahab; Fujioka, Takako

2014-10-15

When two tones with slightly different frequencies are presented to both ears, they interact in the central auditory system and induce the sensation of a beating sound. At low difference frequencies, we perceive a single sound, which is moving across the head between the left and right ears. The percept changes to loudness fluctuation, roughness, and pitch with increasing beat rate. To examine the neural representations underlying these different perceptions, we recorded neuromagnetic cortical responses while participants listened to binaural beats at a continuously varying rate between 3 Hz and 60 Hz. Binaural beat responses were analyzed as neuromagnetic oscillations following the trajectory of the stimulus rate. Responses were largest in the 40-Hz gamma range and at low frequencies. Binaural beat responses at 3 Hz showed opposite polarity in the left and right auditory cortices. We suggest that this difference in polarity reflects the opponent neural population code for representing sound location. Binaural beats at any rate induced gamma oscillations. However, the responses were largest at 40-Hz stimulation. We propose that the neuromagnetic gamma oscillations reflect postsynaptic modulation that allows for precise timing of cortical neural firing. Systematic phase differences between bilateral responses suggest that separate sound representations of a sound object exist in the left and right auditory cortices. We conclude that binaural processing at the cortical level occurs with the same temporal acuity as monaural processing whereas the identification of sound location requires further interpretation and is limited by the rate of object representations. Copyright © 2014 the American Physiological Society.

Catastrophic lava dome failure at Soufrière Hills Volcano, Montserrat, 12-13 July 2003

USGS Publications Warehouse

Herd, Richard A.; Edmonds, Marie; Bass, Venus A.

2005-01-01

The lava dome collapse of 12–13 July 2003 was the largest of the Soufrière Hills Volcano eruption thus far (1995–2005) and the largest recorded in historical times from any volcano; 210 million m3 of dome material collapsed over 18 h and formed large pyroclastic flows, which reached the sea. The evolution of the collapse can be interpreted with reference to the complex structure of the lava dome, which comprised discrete spines and shear lobes and an apron of talus. Progressive slumping of talus for 10 h at the beginning of the collapse generated low-volume pyroclastic flows. It undermined the massive part of the lava dome and eventually prompted catastrophic failure. From 02:00 to 04:40 13 July 2003 large pyroclastic flows were generated; these reached their largest magnitude at 03:35, when the volume flux of material lost from the lava dome probably approached 16 million m3 over two minutes. The high flux of pyroclastic flows into the sea caused a tsunami and a hydrovolcanic explosion with an associated pyroclastic surge, which flowed inland. A vulcanian explosion occurred during or immediately after the largest pyroclastic flows at 03:35 13 July and four further explosions occurred at progressively longer intervals during 13–15 July 2003. The dome collapse lasted approximately 18 h, but 170 of the total 210 million m3 was removed in only 2.6 h during the most intense stage of the collapse.

Three Years of TRMM Precipitation Features. Part 1; Radar, Radiometric, and Lightning Characteristics

NASA Technical Reports Server (NTRS)

Cecil, Daniel J.; Goodman, Steven J.; Boccippio, Dennis J.; Zipser, Edward J.; Nesbitt, Stephen W.

2004-01-01

During its first three years, the Tropical Rainfall Measuring Mission (TRMM) satellite observed nearly six million precipitation features. The population of precipitation features is sorted by lightning flash rate, minimum brightness temperature, maximum radar reflectivity, areal extent, and volumetric rainfall. For each of these characteristics, essentially describing the convective intensity or the size of the features, the population is broken into categories consisting of the top 0.001%, top 0.01%, top 0.1%, top 1%, top 2.4%, and remaining 97.6%. The set of 'weakest / smallest' features comprises 97.6% of the population because that fraction does not have detected lightning, with a minimum detectable flash rate 0.7 fl/min. The greatest observed flash rate is 1351 fl/min; the lowest brightness temperatures are 42 K (85-GHz) and 69 K (37- GHz). The largest precipitation feature covers 335,000 sq km and the greatest rainfall from an individual precipitation feature exceeds 2 x 10(exp 12) kg of water. There is considerable overlap between the greatest storms according to different measures of convective intensity. The largest storms are mostly independent of the most intense storms. The set of storms producing the most rainfall is a convolution of the largest and the most intense storms. This analysis is a composite of the global tropics and subtropics. Significant variability is known to exist between locations, seasons, and meteorological regimes. Such variability will be examined in Part II. In Part I, only a crude land / Ocean separation is made. The known differences in bulk lightning flash rates over land and Ocean result from at least two differences in the precipitation feature population: the frequency of occurrence of intense storms, and the magnitude of those intense storms that do occur. Even when restricted to storms with the same brightness temperature, same size, or same radar reflectivity aloft, the storms over water are considerably less likely to produce lightning than are comparable storms over land.

Three Years of TRMM Precipitation Features. Part 1; Radar, Radiometric, and Lightning Characteristics

NASA Technical Reports Server (NTRS)

Cecil, Daniel J.; Goodman, Steven J.; Boccippio, Dennis J.; Zipser, Edward J.; Nesbitt, Stephen W.

2005-01-01

During its first three years, the Tropical Rainfall Measuring Mission (TRMM) satellite observed nearly six million precipitation features. The population of precipitation features is sorted by lightning flash rate, minimum brightness temperature, maximum radar reflectivity. areal extent, and volumetric rainfall. For each of these characteristics, essentially describing the convective intensity or the size of the features, the population is broken into categories consisting of the top 0.001%, top 0.01%, top 0.1%, top 1%, top 2.4%. and remaining 97.6%. The set of weakest/smallest features composes 97.6% of the population because that fraction does not have detected lightning, with a minimum detectable flash rate of 0.7 flashes (fl) per minute. The greatest observed flash rate is 1351 fl per minute; the lowest brightness temperatures are 42 K (85 GHz) and 69 K (37 GHz). The largest precipitation feature covers 335 000 square kilometers and the greatest rainfall from an individual precipitation feature exceeds 2 x 10 kg per hour of water. There is considerable overlap between the greatest storms according to different measures of convective intensity. The largest storms are mostly independent of the most intense storms. The set of storms producing the most rainfall is a convolution of the largest and the most intense storms. This analysis is a composite of the global Tropics and subtropics. Significant variability is known to exist between locations. seasons, and meteorological regimes. Such variability will be examined in Part II. In Part I, only a crude land-ocean separation is made. The known differences in bulk lightning flash rates over land and ocean result from at least two differences in the precipitation feature population: the frequency of occurrence of intense storms and the magnitude of those intense storms that do occur. Even when restricted to storms with the same brightness temperature, same size, or same radar reflectivity aloft, the storms over water are considerably less likely to produce lightning than are comparable storms over land.

Evolution of complex symbiotic relationships in a morphologically derived family of lichen-forming fungi.

PubMed

Divakar, Pradeep K; Crespo, Ana; Wedin, Mats; Leavitt, Steven D; Hawksworth, David L; Myllys, Leena; McCune, Bruce; Randlane, Tiina; Bjerke, Jarle W; Ohmura, Yoshihito; Schmitt, Imke; Boluda, Carlos G; Alors, David; Roca-Valiente, Beatriz; Del-Prado, Ruth; Ruibal, Constantino; Buaruang, Kawinnat; Núñez-Zapata, Jano; Amo de Paz, Guillermo; Rico, Víctor J; Molina, M Carmen; Elix, John A; Esslinger, Theodore L; Tronstad, Inger Kristin K; Lindgren, Hanna; Ertz, Damien; Gueidan, Cécile; Saag, Lauri; Mark, Kristiina; Singh, Garima; Dal Grande, Francesco; Parnmen, Sittiporn; Beck, Andreas; Benatti, Michel Navarro; Blanchon, Dan; Candan, Mehmet; Clerc, Philippe; Goward, Trevor; Grube, Martin; Hodkinson, Brendan P; Hur, Jae-Seoun; Kantvilas, Gintaras; Kirika, Paul M; Lendemer, James; Mattsson, Jan-Eric; Messuti, María Inés; Miadlikowska, Jolanta; Nelsen, Matthew; Ohlson, Jan I; Pérez-Ortega, Sergio; Saag, Andres; Sipman, Harrie J M; Sohrabi, Mohammad; Thell, Arne; Thor, Göran; Truong, Camille; Yahr, Rebecca; Upreti, Dalip K; Cubas, Paloma; Lumbsch, H Thorsten

2015-12-01

We studied the evolutionary history of the Parmeliaceae (Lecanoromycetes, Ascomycota), one of the largest families of lichen-forming fungi with complex and variable morphologies, also including several lichenicolous fungi. We assembled a six-locus data set including nuclear, mitochondrial and low-copy protein-coding genes from 293 operational taxonomic units (OTUs). The lichenicolous lifestyle originated independently three times in lichenized ancestors within Parmeliaceae, and a new generic name is introduced for one of these fungi. In all cases, the independent origins occurred c. 24 million yr ago. Further, we show that the Paleocene, Eocene and Oligocene were key periods when diversification of major lineages within Parmeliaceae occurred, with subsequent radiations occurring primarily during the Oligocene and Miocene. Our phylogenetic hypothesis supports the independent origin of lichenicolous fungi associated with climatic shifts at the Oligocene-Miocene boundary. Moreover, diversification bursts at different times may be crucial factors driving the diversification of Parmeliaceae. Additionally, our study provides novel insight into evolutionary relationships in this large and diverse family of lichen-forming ascomycetes. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Reversible stress softening of collagen based networks from the jumbo squid mantle (Dosidicus gigas).

PubMed

Torres, F G; Troncoso, O P; Rivas, E R; Gomez, C G; Lopez, D

2014-04-01

Dosidicus gigas is the largest and one of the most abundant jumbo squids in the eastern Pacific Ocean. In this paper we have studied the muscle of the mantle of D. gigas (DGM). Morphological, thermal and rheological properties were assessed by means of atomic force microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential scanning calorimetry, thermogravimetry and oscillatory rheometry. This study allowed us to assess the morphological and rheological properties of a collagen based network occurring in nature. The results showed that the DGM network displays a nonlinear effect called reversible stress softening (RSS) that has been previously described for other types of biological structures such as naturally occurring cellulose networks and actin networks. We propose that the RSS could play a key role on the way jumbo squids withstand hydrostatic pressure. The results presented here confirm that this phenomenon occurs in a wider number of materials than previously thought, all of them exhibiting different size scales as well as physical conformation. Copyright © 2013 Elsevier B.V. All rights reserved.

Quantifying three dimensional reconnection in fragmented current layers

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

Wyper, P. F., E-mail: peter.f.wyper@nasa.gov; Hesse, M., E-mail: michael.hesse-1@nasa.gov

There is growing evidence that when magnetic reconnection occurs in high Lundquist number plasmas such as in the Solar Corona or the Earth's Magnetosphere it does so within a fragmented, rather than a smooth current layer. Within the extent of these fragmented current regions, the associated magnetic flux transfer and energy release occur simultaneously in many different places. This investigation focusses on how best to quantify the rate at which reconnection occurs in such layers. An analytical theory is developed which describes the manner in which new connections form within fragmented current layers in the absence of magnetic nulls. Itmore » is shown that the collective rate at which new connections form can be characterized by two measures; a total rate which measures the true rate at which new connections are formed and a net rate which measures the net change of connection associated with the largest value of the integral of E{sub ||} through all of the non-ideal regions. Two simple analytical models are presented which demonstrate how each should be applied and what they quantify.« less

The largest glitch observed in the Crab pulsar

NASA Astrophysics Data System (ADS)

Shaw, B.; Lyne, A. G.; Stappers, B. W.; Weltevrede, P.; Bassa, C. G.; Lien, A. Y.; Mickaliger, M. B.; Breton, R. P.; Jordan, C. A.; Keith, M. J.; Krimm, H. A.

2018-05-01

We have observed a large glitch in the Crab pulsar (PSR B0531+21). The glitch occurred around MJD 58064 (2017 November 8) when the pulsar underwent an increase in the rotation rate of Δν = 1.530 × 10-5 Hz, corresponding to a fractional increase of Δν/ν = 0.516 × 10-6 making this event the largest glitch ever observed in this source. Due to our high-cadence and long-dwell time observations of the Crab pulsar we are able to partially resolve a fraction of the total spin-up of the star. This delayed spin-up occurred over a timescale of ˜1.7 days and is similar to the behaviour seen in the 1989 and 1996 large Crab pulsar glitches. The spin-down rate also increased at the glitch epoch by Δ \\dot{ν } / \\dot{ν } = 7 × 10^{-3}. In addition to being the largest such event observed in the Crab, the glitch occurred after the longest period of glitch inactivity since at least 1984 and we discuss a possible relationship between glitch size and waiting time. No changes to the shape of the pulse profile were observed near the glitch epoch at 610 MHz or 1520 MHz, nor did we identify any changes in the X-ray flux from the pulsar. The long-term recovery from the glitch continues to progress as \\dot{ν } slowly rises towards pre-glitch values. In line with other large Crab glitches, we expect there to be a persistent change to \\dot{ν }. We continue to monitor the long-term recovery with frequent, high quality observations.

Cardiovascular responses to repetitive exposure to hyper- and hypogravity states produced by parabolic flight.

PubMed

Mukai, C N; Lathers, C M; Charles, J B; Bennett, B S

1994-05-01

Physiologic changes to repetitive hyper- and hypogravity stresses occurring during eight to ten parabolas on NASA's KC-135 aircraft were studied. Hemodynamic responses in 11 subjects in 4 different postures (supine, standing, sitting, and semisupine Space Shuttle launch position) were determined using noninvasive impedance cardiography. Five seconds of heart rate, cardiac index, thoracic fluid index, stroke index, ejection velocity index, and ventricular ejection time data were averaged during four different gravity (g) states: 1.3g (before parabola onset); 1.9g (parabola entry); 0g (parabola peak); and 1.7g (parabola exit) for each subject. The standing position was associated with the largest changes in the cardiovascular response to hypo- and hypergravity. The thoracic fluid index did not indicate a headward redistribution during transition from a simulated launch position to weightlessness. Analysis of the eight to ten parabolas revealed that, in general, values obtained at 1.8g differed from 1.6g, 0g differed from 1.6 and 1.3g, and 1.6g differed from 1.3g. The factors of gravity, thoracic fluid index, and cardiac index exhibited significant differences that were most likely to occur between parabola 1 versus parabolas 6, 7, and 8, and parabola 2 versus parabolas 4 through 8. Only the parameter of thoracic fluid index exhibited significance for parabolas 3 versus parabolas 6 and 7.

Cardiovascular responses to repetitive exposure to hyper- and hypogravity states produced by parabolic flight

NASA Technical Reports Server (NTRS)

Mukai, C. N.; Lathers, C. M.; Charles, J. B.; Bennett, B. S.

1994-01-01

Physiologic changes to repetitive hyper- and hypogravity stresses occurring during eight to ten parabolas on NASA's KC-135 aircraft were studied. Hemodynamic responses in 11 subjects in 4 different postures (supine, standing, sitting, and semisupine Space Shuttle launch position) were determined using noninvasive impedance cardiography. Five seconds of heart rate, cardiac index, thoracic fluid index, stroke index, ejection velocity index, and ventricular ejection time data were averaged during four different gravity (g) states: 1.3g (before parabola onset); 1.9g (parabola entry); 0g (parabola peak); and 1.7g (parabola exit) for each subject. The standing position was associated with the largest changes in the cardiovascular response to hypo- and hypergravity. The thoracic fluid index did not indicate a headward redistribution during transition from a simulated launch position to weightlessness. Analysis of the eight to ten parabolas revealed that, in general, values obtained at 1.8g differed from 1.6g, 0g differed from 1.6 and 1.3g, and 1.6g differed from 1.3g. The factors of gravity, thoracic fluid index, and cardiac index exhibited significant differences that were most likely to occur between parabola 1 versus parabolas 6, 7, and 8, and parabola 2 versus parabolas 4 through 8. Only the parameter of thoracic fluid index exhibited significance for parabolas 3 versus parabolas 6 and 7.

Multimodal dispersal during the range expansion of the tropical house gecko Hemidactylus mabouia

PubMed Central

Short, Kristen H; Petren, Kenneth

2011-01-01

Dispersal influences both the ecological and evolutionary dynamics of range expansion. While some studies have demonstrated a role for human-mediated dispersal during invasion, the genetic effects of such dispersal remain to be understood, particularly in terrestrial range expansions. In this study, we investigated multimodal dispersal during the range expansion of the invasive gecko Hemidactylus mabouia in Florida using 12 microsatellite loci. We investigated dispersal patterns at the regional scale (metropolitan areas), statewide scale (state of Florida), and global scale (including samples from the native range). Dispersal was limited at the smallest, regional scale, within metropolitan areas, as reflected by the presence of genetic structure at this scale, which is in agreement with a previous study in this same invasion at even smaller spatial scales. Surprisingly, there was no detectable genetic structure at the intermediate statewide scale, which suggests dispersal is not limited across the state of Florida. There was evidence of genetic differentiation between Florida and other areas where H. mabouia occurs, so we concluded that at the largest scale, dispersal was limited. Humans likely contributed to patterns of dispersal at all three scales but in different ways. Infrequent low-volume dispersal has occurred within regions, frequent high-volume dispersal has occurred across the state, and infrequent long-distance dispersal has occurred among continents at the global scale. This study highlights the importance of considering different modes of dispersal at multiple spatial scales to understand the dynamics of invasion and range expansion. PMID:22393494

Highway safety research : a national agenda : executive summary.

DOT National Transportation Integrated Search

2001-01-01

Motor vehicle-related injury and death is the nations largest public health problem. The economic costs to society : will approach $2 trillion and an even greater intangible human loss will occur to family and friends of the 33 million : victims. :...

Anatomizing one of the largest saltwater inflows into the Baltic Sea in December 2014

NASA Astrophysics Data System (ADS)

Gräwe, Ulf; Naumann, Michael; Mohrholz, Volker; Burchard, Hans

2015-11-01

In December 2014, an exceptional inflow event into the Baltic Sea was observed, a so-called Major Baltic Inflow (MBI). Such inflow events are important for the deep water ventilation in the Baltic Sea and typically occur every 3-10 years. Based on first observational data sets, this inflow had been ranked as the third largest since 100 years. With the help of a multinested modeling system, reaching from the North Atlantic (8 km resolution) to the Western Baltic Sea (600 m resolution, which is baroclinic eddy resolving), this event is reproduced in detail. The model gave a slightly lower salt transport of 3.8 Gt, compared to the observational estimate of four Gt. Moreover, by using passive tracers to mark the different inflowing water masses, including an age tracer, the inflowing water masses could be tracked and their paths and timing through the different basins could be reproduced and investigated. The analysis is supported by the recently developed Total Exchange Flow (TEF) to quantify the volume transport in different salinity classes. To account for uncertainties in the modeled velocity and tracer fields, a Monte Carlo Analysis (MCA) is applied to correct possible biases and errors. With the help of the MCA, 95% confidence intervals are computed for the transport estimates. Based on the MCA, the "best guess" of the volume transport is 291.0 ± 13.65 km3 and 3.89 ± 0.18 Gt for the total salt transport.

Two new species of Euconnus (Rhomboconnus) in Peru and Bolivia (Coleoptera, Staphylinidae, Scydmaeninae).

PubMed

JaŁoszyŃski, PaweŁ

2018-01-25

To date, the subgenus Rhomboconnus Franz of Euconnus Thomson was represented by ten species known to occur in Venezuela, Panama and Ecuador. For the first time Rhomboconnus is reported to occur in Peru and Bolivia, and two new species are described: Euconnus wari sp. n. (Peru) and E. inkachakanus sp. n. (Bolivia). The latter species is the largest representative of Rhomboconnus, with body length exceeding 3 mm.

Structural origin of fractional Stokes-Einstein relation in glass-forming liquids

NASA Astrophysics Data System (ADS)

Pan, Shaopeng; Wu, Z. W.; Wang, W. H.; Li, M. Z.; Xu, Limei

2017-01-01

In many glass-forming liquids, fractional Stokes-Einstein relation (SER) is observed above the glass transition temperature. However, the origin of such phenomenon remains elusive. Using molecular dynamics simulations, we investigate the break- down of SER and the onset of fractional SER in a model of metallic glass-forming liquid. We find that SER breaks down when the size of the largest cluster consisting of trapped atoms starts to increase sharply at which the largest cluster spans half of the simulations box along one direction, and the fractional SER starts to follows when the largest cluster percolates the entire system and forms 3-dimentional network structures. Further analysis based on the percolation theory also confirms that percolation occurs at the onset of the fractional SER. Our results directly link the breakdown of the SER with structure inhomogeneity and onset of the fraction SER with percolation of largest clusters, thus provide a possible picture for the break- down of SER and onset of fractional SER in glass-forming liquids, which is is important for the understanding of the dynamic properties in glass-forming liquids.

Scale effects and a method for similarity evaluation in micro electrical discharge machining

NASA Astrophysics Data System (ADS)

Liu, Qingyu; Zhang, Qinhe; Wang, Kan; Zhu, Guang; Fu, Xiuzhuo; Zhang, Jianhua

2016-08-01

Electrical discharge machining(EDM) is a promising non-traditional micro machining technology that offers a vast array of applications in the manufacturing industry. However, scale effects occur when machining at the micro-scale, which can make it difficult to predict and optimize the machining performances of micro EDM. A new concept of "scale effects" in micro EDM is proposed, the scale effects can reveal the difference in machining performances between micro EDM and conventional macro EDM. Similarity theory is presented to evaluate the scale effects in micro EDM. Single factor experiments are conducted and the experimental results are analyzed by discussing the similarity difference and similarity precision. The results show that the output results of scale effects in micro EDM do not change linearly with discharge parameters. The values of similarity precision of machining time significantly increase when scaling-down the capacitance or open-circuit voltage. It is indicated that the lower the scale of the discharge parameter, the greater the deviation of non-geometrical similarity degree over geometrical similarity degree, which means that the micro EDM system with lower discharge energy experiences more scale effects. The largest similarity difference is 5.34 while the largest similarity precision can be as high as 114.03. It is suggested that the similarity precision is more effective in reflecting the scale effects and their fluctuation than similarity difference. Consequently, similarity theory is suitable for evaluating the scale effects in micro EDM. This proposed research offers engineering values for optimizing the machining parameters and improving the machining performances of micro EDM.

Ballistic Blocks Surrounding Kilauea's Caldera

NASA Astrophysics Data System (ADS)

Swanson, D.; Zolkos, S.; Haravitch, B.

2010-12-01

Thousands of lithic blocks dot the surface around Kilauea’s caldera, erupted ballistically at the end of the 1790 eruption or soon thereafter. Most of the blocks occur in the western and southern sectors, probably reflecting the proximity of vents on the caldera floor. We mapped the ejecta field, measuring most of the blocks with nominal diameters ((a+b+c)/3) more than 75 cm and many of the smaller ones, noting distinctive lithologies. The distributions, sizes, and lithologies suggest 7-8 different ballistic bursts from 3-4 generalized vent areas. We measured 15 blocks with nominal diameters (ND) of 150-201 cm, 169 blocks with ND 100-149 cm, 308 blocks with ND 75-99 cm, 684 blocks with ND 50-74 cm, and 545 blocks with ND 25-49 cm. The smaller blocks were measured only in outlying areas, where they were the largest in the neighborhood, but they occur throughout the field. Twelve blocks with ND >150 cm lie within 1.7 km west and south of the center of Halema`uma`u; a vent near this location likely erupted the blocks. Three of the largest blocks, however, are 2.2-2.7 km north of Halema`uma`u and probably came from a more northerly vent. This interpretation is supported by the distributions of all blocks with ND >100 cm, which define at least 4, and possibly 5, different dispersal lobes; three cluster near Halema`uma`u, one is slightly north, and the one with the three large blocks is still farther north. The blocks have typical lithologies for Kilauea’s summit, including coarse basalt or fine gabbro derived from the centers of thick flows, solidified lakes, or small intrusions. Three lithologies are distinctive and help define 3, possibly 4, discrete bursts. Blocks of fine-grained basalt riddled with segregation veins occur only in a lobe 1.3 km wide reaching as far as 1.8 km southwest of Halema`uma`u; this lobe overlaps slightly with one defined by block size but is mostly distinct and probably indicates a separate burst. A cluster of blocks with puffy, somewhat fluidal rinds forms a distinct lobe 800 m wide out to 1.8 km southeast of Halema`uma`u. The cluster also contains many cored bombs and a few juvenile bombs and lapilli without cores. This is the only ballistic lobe that contains much juvenile material, though older fall and surge deposits of 1790 and pre1790 vintage also carry cored bombs and juvenile lapilli. This lobe is coextensive with one defined by block size. The largest ballistic lobe has abundant, commonly oxidized blocks of olivine-rich basalt, some verging on picrite. The main lobe, about 900 m wide, extends 0.9-3.6 km southeast of Halema`uma`u; three olivine-rich blocks between 100 and 150 cm ND occur 2.4 to 3.3 km out. A possible second lobe of olivine-rich blocks occurs out to 1.6 km due south of Halema`uma`u. The lobes indicate a directionality and inclined ejection angle for at least some of the ballistic eruptions, as was true for the observed, but much smaller, ballistic eruptions in 1924. The scarcity of juvenile ejecta argues for phreatic eruptions that were likely initiated at or below the water table, today about 600 m below the caldera rim. If so, some ballistic blocks weighing a few tonnes were thrown at least 600 m above the vent. The dynamics of these explosive eruptions are under study.

Temporal variation of the arterial pressure in healthy young people and its relation to geomagnetic activity in Mexico

NASA Astrophysics Data System (ADS)

Azcárate, T.; Mendoza, B.; Sánchez de la Peña, S.; Martínez, J. L.

2012-11-01

We present a study of the temporal behavior of the systolic (SBP) and diastolic (DBP) blood pressure for a sample of 51 normotensive, healthy volunteers, 18 men and 33 women with an average age of 19 years old in Mexico City, Mexico, during April and May, 2008. We divided the data by sex along the circadian rhythm. Three geomagnetic storms occurred during the studied time-span. The strongest one, a moderate storm, is attributed to a coronal hole border that reached the Earth. The ANOVA test applied to the strongest storm showed that even though we are dealing with a moderate geomagnetic storm, there are statistically significant responses of the blood pressure. The superposed epoch analysis during a three-day window around the strongest storm shows that on average the largest changes occurred for the SBP. Moreover, the SBP largest increases occurred two days before and one day after this storm, and women are the most sensitive group as they present larger SBP and DBP average changes than men. Finally, given the small size of the sample, we cannot generalize our results.

Estimating Population Density of the San Martin Titi Monkey (Callicebus oenanthe) in Peru Using Vocalisations.

PubMed

van Kuijk, Silvy M; García-Suikkanen, Carolina; Tello-Alvarado, Julio C; Vermeer, Jan; Hill, Catherine M

2015-01-01

We calculated the population density of the critically endangered Callicebus oenanthe in the Ojos de Agua Conservation Concession, a dry forest area in the department of San Martin, Peru. Results showed significant differences (p < 0.01) in group densities between forest boundaries (16.5 groups/km2, IQR = 21.1-11.0) and forest interior (4.0 groups/km2, IQR = 5.0-0.0), suggesting the 2,550-ha area harbours roughly 1,150 titi monkeys. This makes Ojos de Agua an important cornerstone in the conservation of the species, because it is one of the largest protected areas where the species occurs. © 2016 S. Karger AG, Basel.

Achieving the American dream: facilitators and barriers to health and mental health for Latino immigrants.

PubMed

Shobe, Marcia A; Coffman, Maren J; Dmochowski, Jacek

2009-01-01

Latinos are the largest minority group in the U.S. For Latino immigrants, a shift in migration from larger to smaller cities has recently occurred; the Latino immigrant population in Charlotte, North Carolina, has increased by 634% since 1990. The extent to which immigrants can achieve health and well-being is often related to employment, healthcare access, and social support. This study explored the human, social, and financial capital circumstances of Latino immigrants new to Charlotte and examined the effects of different aspects of capital on health outcomes. Findings indicate that capital is significantly associated with functional status and depression. Implications for social work are discussed.

Mapping the MMPI-2-RF Substantive Scales Onto Internalizing, Externalizing, and Thought Dysfunction Dimensions in a Forensic Inpatient Setting.

PubMed

Romero, Isabella E; Toorabally, Nasreen; Burchett, Danielle; Tarescavage, Anthony M; Glassmire, David M

2017-01-01

Contemporary models of psychopathology-encompassing internalizing, externalizing, and thought dysfunction factors-have gained significant support. Although research indicates the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008 /2011) measures these domains of psychopathology, this study addresses extant limitations in MMPI-2-RF diagnostic validity research by examining associations between all MMPI-2-RF substantive scales and broad dichotomous indicators of internalizing, externalizing, and thought dysfunction diagnoses in a sample of 1,110 forensic inpatients. Comparing those with and without internalizing diagnoses, notable effects were observed for Negative Emotionality/Neuroticism-Revised (NEGE-r), Emotional/Internalizing Dysfunction (EID), Dysfunctional Negative Emotions (RC7), Demoralization (RCd), and several other internalizing and somatic/cognitive scales. Comparing those with and without thought dysfunction diagnoses, the largest hypothesized differences occurred for Thought Dysfunction (THD), Aberrant Experiences (RC8), and Psychoticism-Revised (PSYC-r), although unanticipated differences were observed on internalizing and interpersonal scales, likely reflecting the high prevalence of internalizing dysfunction in forensic inpatients not experiencing thought dysfunction. Comparing those with and without externalizing diagnoses, the largest effects were for Substance Abuse (SUB), Antisocial Behavior (RC4), Behavioral/Externalizing Dysfunction (BXD), Juvenile Conduct Problems (JCP), and Disconstraint-Revised (DISC-r). Multivariate models evidenced similar results. Findings support the construct validity of MMPI-2-RF scales as measures of internalizing, thought, and externalizing dysfunction.

The Precipitation Characteristics of ISCCP Tropical Weather States

NASA Technical Reports Server (NTRS)

Lee, Dongmin; Oreopoulos, Lazaros; Huffman, George J.; Rossow, William B.; Kang, In-Sik

2011-01-01

We examine the daytime precipitation characteristics of the International Satellite Cloud Climatology Project (ISCCP) weather states in the extended tropics (35 deg S to 35 deg N) for a 10-year period. Our main precipitation data set is the TRMM Multisatellite Precipitation Analysis 3B42 data set, but Global Precipitation Climatology Project daily data are also used for comparison. We find that the most convective weather state (WS1), despite an occurrence frequency below 10%, is the most dominant state with regard to surface precipitation, producing both the largest mean precipitation rates when present and the largest percent contribution to the total precipitation of the tropical zone of our study; yet, even this weather state appears to not precipitate about half the time. WS1 exhibits a modest annual cycle of domain-average precipitation rate, but notable seasonal shifts in its geographic distribution. The precipitation rates of the other weather states tend to be stronger when occurring before or after WS1. The relative contribution of the various weather states to total precipitation is different between ocean and land, with WS1 producing more intense precipitation on average over ocean than land. The results of this study, in addition to advancing our understanding of the current state of tropical precipitation, can serve as a higher order diagnostic test on whether it is distributed realistically among different weather states in atmospheric models.

Novel insight into the origin of the growth dynamics of sauropod dinosaurs.

PubMed

Cerda, Ignacio Alejandro; Chinsamy, Anusuya; Pol, Diego; Apaldetti, Cecilia; Otero, Alejandro; Powell, Jaime Eduardo; Martínez, Ricardo Nestor

2017-01-01

Sauropod dinosaurs include the largest terrestrial animals and are considered to have uninterrupted rapid rates of growth, which differs from their more basal relatives, which have a slower cyclical growth. Here we examine the bone microstructure of several sauropodomorph dinosaurs, including basal taxa, as well as the more derived sauropods. Although our results agree that the plesiomorphic condition for Sauropodomorpha is cyclical growth dynamics, we found that the hypothesized dichotomy between the growth patterns of basal and more derived sauropodomorphs is not supported. Here, we show that sauropod-like growth dynamics of uninterrupted rapid growth also occurred in some basal sauropodomorphs, and that some basal sauropods retained the plesiomorphic cyclical growth patterns. Among the sauropodomorpha it appears that the basal taxa exploited different growth strategies, but the more derived Eusauropoda successfully utilized rapid, uninterrupted growth strategies.

Novel insight into the origin of the growth dynamics of sauropod dinosaurs

PubMed Central

Cerda, Ignacio Alejandro; Chinsamy, Anusuya; Pol, Diego; Apaldetti, Cecilia; Otero, Alejandro; Martínez, Ricardo Nestor

2017-01-01

Sauropod dinosaurs include the largest terrestrial animals and are considered to have uninterrupted rapid rates of growth, which differs from their more basal relatives, which have a slower cyclical growth. Here we examine the bone microstructure of several sauropodomorph dinosaurs, including basal taxa, as well as the more derived sauropods. Although our results agree that the plesiomorphic condition for Sauropodomorpha is cyclical growth dynamics, we found that the hypothesized dichotomy between the growth patterns of basal and more derived sauropodomorphs is not supported. Here, we show that sauropod-like growth dynamics of uninterrupted rapid growth also occurred in some basal sauropodomorphs, and that some basal sauropods retained the plesiomorphic cyclical growth patterns. Among the sauropodomorpha it appears that the basal taxa exploited different growth strategies, but the more derived Eusauropoda successfully utilized rapid, uninterrupted growth strategies. PMID:28654696

Linking diurnal cycles of river flow to interannual variations in climate

USGS Publications Warehouse

Lundquist, Jessica D.; Dettinger, Michael D.

2003-01-01

Many rivers in the Western United States have diurnal variations exceeding 10% of their mean flow in the spring and summer months. The shape and timing of the diurnal cycle is influenced by an interplay of the snow, topography, vegetation, and meteorology in a basin, and the measured result differs between wet and dry years. The largest interannual differences occur during the latter half of the melt season, as the snowline retreats to the highest elevations and most shaded slopes in a basin. In most basins, during this period, the hour of peak discharge shifts to later in the day, and the relative amplitude of the diurnal cycle decreases. The magnitude and rate of these changes in the diurnal cycle vary between years and may provide clues about how long- term hydroclimatic variations affect short-term basin dynamics.

Working the kinks out of nucleosomal DNA

PubMed Central

Olson, Wilma K.; Zhurkin, Victor B.

2011-01-01

Condensation of DNA in the nucleosome takes advantage of its double-helical architecture. The DNA deforms at sites where the base pairs face the histone octamer. The largest so-called kink-and-slide deformations occur in the vicinity of arginines that penetrate the minor groove. Nucleosome structures formed from the 601 positioning sequence differ subtly from those incorporating an AT-rich human α-satellite DNA. Restraints imposed by the histone arginines on the displacement of base pairs can modulate the sequence-dependent deformability of DNA and potentially contribute to the unique features of the different nucleosomes. Steric barriers mimicking constraints found in the nucleosome induce the simulated large-scale rearrangement of canonical B-DNA to kink-and-slide states. The pathway to these states shows non-harmonic behavior consistent with bending profiles inferred from AFM measurements. PMID:21482100

Jim Crow and premature mortality among the US Black and White population, 1960-2009: an age-period-cohort analysis.

PubMed

Krieger, Nancy; Chen, Jarvis T; Coull, Brent A; Beckfield, Jason; Kiang, Mathew V; Waterman, Pamela D

2014-07-01

Scant research has analyzed the health impact of abolition of Jim Crow (ie, legal racial discrimination overturned by the US 1964 Civil Rights Act). We used hierarchical age-period-cohort models to analyze US national black and white premature mortality rates (death before 65 years of age) in 1960-2009. Within a context of declining US black and white premature mortality rates and a persistent 2-fold excess black risk of premature mortality in both the Jim Crow and non-Jim Crow states, analyses including random period, cohort, state, and county effects and fixed county income effects found that, within the black population, the largest Jim Crow-by-period interaction occurred in 1960-1964 (mortality rate ratio [MRR] = 1.15 [95% confidence interval = 1.09-1.22), yielding the largest overall period-specific Jim Crow effect MRR of 1.27, with no such interactions subsequently observed. Furthermore, the most elevated Jim Crow-by-cohort effects occurred for birth cohorts from 1901 through 1945 (MRR range = 1.05-1.11), translating to the largest overall cohort-specific Jim Crow effect MRRs for the 1921-1945 birth cohorts (MRR ~ 1.2), with no such interactions subsequently observed. No such interactions between Jim Crow and either period or cohort occurred among the white population. Together, the study results offer compelling evidence of the enduring impact of both Jim Crow and its abolition on premature mortality among the US black population, although insufficient to eliminate the persistent 2-fold black excess risk evident in both the Jim Crow and non-Jim Crow states from 1960 to 2009.

Jim Crow and Premature Mortality Among the US Black and White Population, 1960–2009

PubMed Central

Krieger, Nancy; Chen, Jarvis T.; Coull, Brent A.; Beckfield, Jason; Kiang, Mathew V.; Waterman, Pamela D.

2016-01-01

Background Scant research has analyzed the health impact of abolition of Jim Crow (ie, legal racial discrimination overturned by the US 1964 Civil Rights Act). Methods We used hierarchical age–period–cohort models to analyze US national black and white premature mortality rates (death before 65 years of age) in 1960–2009. Results Within a context of declining US black and white premature mortality rates and a persistent 2-fold excess black risk of premature mortality in both the Jim Crow and non-Jim Crow states, analyses including random period, cohort, state, and county effects and fixed county income effects found that, within the black population, the largest Jim Crow-by-period interaction occurred in 1960–1964 (mortality rate ratio [MRR] = 1.15 [95% confidence interval = 1.09–1.22), yielding the largest overall period-specific Jim Crow effect MRR of 1.27, with no such interactions subsequently observed. Furthermore, the most elevated Jim Crow-by-cohort effects occurred for birth cohorts from 1901 through 1945 (MRR range = 1.05–1.11), translating to the largest overall cohort-specific Jim Crow effect MRRs for the 1921–1945 birth cohorts (MRR ~ 1.2), with no such interactions subsequently observed. No such interactions between Jim Crow and either period or cohort occurred among the white population. Conclusion Together, the study results offer compelling evidence of the enduring impact of both Jim Crow and its abolition on premature mortality among the US black population, although insufficient to eliminate the persistent 2-fold black excess risk evident in both the Jim Crow and non-Jim Crow states from 1960 to 2009. PMID:24825344

Solar Energetic Particle Variations

NASA Technical Reports Server (NTRS)

Reames, D. V.

2003-01-01

In the largest solar energetic-particle (SEP) events, acceleration occurs at shock waves driven out from the Sun by coronal mass ejections (CMEs). In fact, the highest proton intensities directly measured near Earth at energies up to approximately 1 GeV occur at the time of passage of shocks, which arrive about a day after the CMEs leave the Sun. CME-driven shocks expanding across magnetic fields can fill over half of the heliosphere with SEPs. Proton-generated Alfven waves trap particles near the shock for efficient acceleration but also throttle the intensities at Earth to the streaming limit early in the events. At high energies, particles begin to leak from the shock and the spectrum rolls downward to form an energy-spectral 'knee' that can vary in energy from approximately 1 MeV to approximately 1 GeV in different events. All of these factors affect the radiation dose as a function of depth and latitude in the Earth's atmosphere and the risk to astronauts and equipment in space. SEP ionization of the polar atmosphere produces nitrates that precipitate to become trapped in the polar ice. Observations of nitrate deposits in ice cores reveal individual large SEP events and extend back approximately 400 years. Unlike sunspots, SEP events follow the approximately 80-100-year Gleissberg cycle rather faithfully and are now at a minimum in that cycle. The largest SEP event in the last 400 years appears to be related to the flare observed by Carrington in 1859, but the probability of SEP events with such large fluences falls off sharply because of the streaming limit.

Fast and slow spindles during the sleep slow oscillation: disparate coalescence and engagement in memory processing.

PubMed

Mölle, Matthias; Bergmann, Til O; Marshall, Lisa; Born, Jan

2011-10-01

Thalamo-cortical spindles driven by the up-state of neocortical slow (< 1 Hz) oscillations (SOs) represent a candidate mechanism of memory consolidation during sleep. We examined interactions between SOs and spindles in human slow wave sleep, focusing on the presumed existence of 2 kinds of spindles, i.e., slow frontocortical and fast centro-parietal spindles. Two experiments were performed in healthy humans (24.5 ± 0.9 y) investigating undisturbed sleep (Experiment I) and the effects of prior learning (word paired associates) vs. non-learning (Experiment II) on multichannel EEG recordings during sleep. Only fast spindles (12-15 Hz) were synchronized to the depolarizing SO up-state. Slow spindles (9-12 Hz) occurred preferentially at the transition into the SO down-state, i.e., during waning depolarization. Slow spindles also revealed a higher probability to follow rather than precede fast spindles. For sequences of individual SOs, fast spindle activity was largest for "initial" SOs, whereas SO amplitude and slow spindle activity were largest for succeeding SOs. Prior learning enhanced this pattern. The finding that fast and slow spindles occur at different times of the SO cycle points to disparate generating mechanisms for the 2 kinds of spindles. The reported temporal relationships during SO sequences suggest that fast spindles, driven by the SO up-state feed back to enhance the likelihood of succeeding SOs together with slow spindles. By enforcing such SO-spindle cycles, particularly after prior learning, fast spindles possibly play a key role in sleep-dependent memory processing.

Explanatory models of diabetes in the U.S. and Mexico: the patient-provider gap and cultural competence.

PubMed

Weller, Susan C; Baer, Roberta D; Garcia de Alba Garcia, Javier; Salcedo Rocha, Ana L

2012-09-01

Successful management of type 2 diabetes requires support and collaboration between diabetic patients, their health care providers, family and community. Using data collected in 1994-2001, we describe illness beliefs of physicians, patients, and representative samples of community members in the US and Mexico. We test whether differences in conceptualizations of diabetes are greater across national and linguistic boundaries or between physicians and lay groups. Interviews were conducted in southern Texas on the Mexican border and in Guadalajara, Mexico. Culturally appropriate interview materials were developed with a mixed-methods approach. Qualitative interviews elicited beliefs about causes, risks, symptoms, and treatments for diabetes and salient themes were incorporated into structured interviews. A cultural consensus analysis was used to verify salient themes within each of the six samples. The consistency in responses in each of the six samples indicated a shared core of beliefs that transcended individual variations. The greatest differences occurred between physician and lay samples; patient and community models were more similar to one another than to the physician models. Differences between physicians and patients may affect optimal management of diabetes, but these differences do not appear to be simply a function of differences in national culture and language, as the largest differences occurred in Mexico. This suggests that rather than cultural competence per se, formal educational levels and class differences may also play an important role in patient understanding and the gap in patient-provider understanding. Copyright © 2012 Elsevier Ltd. All rights reserved.

Metapopulation Dynamics of the Mistletoe and Its Host in Savanna Areas with Different Fire Occurrence

PubMed Central

Teodoro, Grazielle Sales; van den Berg, Eduardo; Arruda, Rafael

2013-01-01

Mistletoes are aerial hemiparasitic plants which occupy patches of favorable habitat (host trees) surrounded by unfavorable habitat and may be possibly modeled as a metapopulation. A metapopulation is defined as a subdivided population that persists due to the balance between colonization and extinction in discrete habitat patches. Our aim was to evaluate the dynamics of the mistletoe Psittacanthus robustus and its host Vochysia thyrsoidea in three Brazilian savanna areas using a metapopulation approach. We also evaluated how the differences in terms of fire occurrence affected the dynamic of those populations (two areas burned during the study and one was fire protected). We monitored the populations at six-month intervals. P. robustus population structure and dynamics met the expected criteria for a metapopulation: i) the suitable habitats for the mistletoe occur in discrete patches; (ii) local populations went extinct during the study and (iii) colonization of previously non-occupied patches occurred. The ratio of occupied patches decreased in all areas with time. Local mistletoe populations went extinct due to two different causes: patch extinction in area with no fire and fire killing in the burned areas. In a burned area, the largest decrease of occupied patch ratios occurred due to a fire event that killed the parasites without, however, killing the host trees. The greatest mortality of V. thyrsoidea occurred in the area without fire. In this area, all the dead trees supported mistletoe individuals and no mortality was observed for parasite-free trees. Because P. robustus is a fire sensitive species and V. thyrsoidea is fire tolerant, P. robustus seems to increase host mortality, but its effect is lessened by periodic burning that reduces the parasite loads. PMID:23776554

Circulating sex hormones and breast cancer risk factors in postmenopausal women: reanalysis of 13 studies

PubMed Central

Key, T J; Appleby, P N; Reeves, G K; Roddam, A W; Helzlsouer, K J; Alberg, A J; Rollison, D E; Dorgan, J F; Brinton, L A; Overvad, K; Kaaks, R; Trichopoulou, A; Clavel-Chapelon, F; Panico, S; Duell, E J; Peeters, P H M; Rinaldi, S; Fentiman, I S; Dowsett, M; Manjer, J; Lenner, P; Hallmans, G; Baglietto, L; English, D R; Giles, G G; Hopper, J L; Severi, G; Morris, H A; Hankinson, S E; Tworoger, S S; Koenig, K; Zeleniuch-Jacquotte, A; Arslan, A A; Toniolo, P; Shore, R E; Krogh, V; Micheli, A; Berrino, F; Barrett-Connor, E; Laughlin, G A; Kabuto, M; Akiba, S; Stevens, R G; Neriishi, K; Land, C E; Cauley, J A; Lui, Li Yung; Cummings, Steven R; Gunter, M J; Rohan, T E; Strickler, H D

2011-01-01

Background: Breast cancer risk for postmenopausal women is positively associated with circulating concentrations of oestrogens and androgens, but the determinants of these hormones are not well understood. Methods: Cross-sectional analyses of breast cancer risk factors and circulating hormone concentrations in more than 6000 postmenopausal women controls in 13 prospective studies. Results: Concentrations of all hormones were lower in older than younger women, with the largest difference for dehydroepiandrosterone sulphate (DHEAS), whereas sex hormone-binding globulin (SHBG) was higher in the older women. Androgens were lower in women with bilateral ovariectomy than in naturally postmenopausal women, with the largest difference for free testosterone. All hormones were higher in obese than lean women, with the largest difference for free oestradiol, whereas SHBG was lower in obese women. Smokers of 15+ cigarettes per day had higher levels of all hormones than non-smokers, with the largest difference for testosterone. Drinkers of 20+ g alcohol per day had higher levels of all hormones, but lower SHBG, than non-drinkers, with the largest difference for DHEAS. Hormone concentrations were not strongly related to age at menarche, parity, age at first full-term pregnancy or family history of breast cancer. Conclusion: Sex hormone concentrations were strongly associated with several established or suspected risk factors for breast cancer, and may mediate the effects of these factors on breast cancer risk. PMID:21772329

Effects of the catastrophic flood of December 1966, north rim area, eastern Grand Canyon, Arizona

USGS Publications Warehouse

Cooley, Maurice E.; Aldridge, B.N.; Euler, Robert C.

1977-01-01

Precipitation from the unusual storm of December 1966 was concentrated on highlands in northern Arizona, southwestern Utah , southern Nevada, and south-central California and caused widely scattered major floods in the four States. In Arizona the largest amount of precipitation was in the north rim area of eastern Grand Canyon, where about 14 inches was measured. The largest flows occurred along Bright Angel Creek and the MilK Creek-Dragon Creek part of the Crystal Creek drainage basin. The maximum effects of the flood were along Milk Creek-Dragon Creek, where a mudflow caused extensive channel modification. Floods that occurred in the Bright Angel and Crystal Creek basins have a recurrence interval of only once in several centuries. The streamflow that resulted from the storm on the Kaibab Plateau caused considerable local scouring and deepening of channels, including some renewed arroyo cutting. The most catastrophic effects of the 1966 floods were caused by two mudflows that extended from the edge of the Kaibab Plateau along Dragon Creek in the Crystal Creek basin and Lava Creek in the Chuar Creek basin to the Colorado River. More than 10 other large mudflows occurred in Nankoweap, Kwagunt, Crystal, and Shinumo Creek basins. About 80 large debris slides left conspicuous scars in the amphitheaters at the heads of the side gorges, and at least 10 small slides occurred on the Kaibab Plateau. (Woodard-USGS)

Differences in visible and near-infrared light reflectance between orange fruit and leaves

NASA Technical Reports Server (NTRS)

Gausman, H. W.; Escobar, D. E.; Berumen, A.

1975-01-01

The objective was to find the best time during the season (April 26, 1972 to January 8, 1973) to distinguish orange fruit from leaves by spectrophotometrically determining at 10-day intervals when the difference in visible (550- and 650-nm wavelengths) and near-infrared (850-nm wavelength) light reflectance between fruit and nearby leaves was largest. December 5 to January 8 was the best time to distinguish fruit from leaves. During this period the fruit's color was rapidly changing from green to yellow, and the difference in visible light reflectance between fruit and leaves was largest. The difference in near-infrared reflectance between leaves and fruit remained essentially constant during ripening when the difference in visible light reflectance between leaves and fruit was largest.

Aftershocks and triggered events of the Great 1906 California earthquake

USGS Publications Warehouse

Meltzner, A.J.; Wald, D.J.

2003-01-01

The San Andreas fault is the longest fault in California and one of the longest strike-slip faults in the world, yet little is known about the aftershocks following the most recent great event on the San Andreas, the Mw 7.8 San Francisco earthquake on 18 April 1906. We conducted a study to locate and to estimate magnitudes for the largest aftershocks and triggered events of this earthquake. We examined existing catalogs and historical documents for the period April 1906 to December 1907, compiling data on the first 20 months of the aftershock sequence. We grouped felt reports temporally and assigned modified Mercalli intensities for the larger events based on the descriptions judged to be the most reliable. For onshore and near-shore events, a grid-search algorithm (derived from empirical analysis of modern earthquakes) was used to find the epicentral location and magnitude most consistent with the assigned intensities. For one event identified as far offshore, the event's intensity distribution was compared with those of modern events, in order to contrain the event's location and magnitude. The largest aftershock within the study period, an M ???6.7 event, occurred ???100 km west of Eureka on 23 April 1906. Although not within our study period, another M ???6.7 aftershock occurred near Cape Mendocino on 28 October 1909. Other significant aftershocks included an M ???5.6 event near San Juan Bautista on 17 May 1906 and an M ???6.3 event near Shelter Cove on 11 August 1907. An M ???4.9 aftershock occurred on the creeping segment of the San Andreas fault (southeast of the mainshock rupture) on 6 July 1906. The 1906 San Francisco earthquake also triggered events in southern California (including separate events in or near the Imperial Valley, the Pomona Valley, and Santa Monica Bay), in western Nevada, in southern central Oregon, and in western Arizona, all within 2 days of the mainshock. Of these trigerred events, the largest were an M ???6.1 earthquake near Brawley and an M ???5.0 event under or near Santa Monica Bay, 11.3 and 31.3 hr after the San Francisco mainshock, respectively. The western Arizona event is inferred to have been triggered dynamically. In general, the largest aftershocks occurred at the ends of the 1906 rupture or away from the rupture entirely; very few significant aftershocks occurred along the mainshock rupture itself. The total number of large aftershocks was less than predicted by a generic model based on typical California mainshock-aftershock statistics, and the 1906 sequence appears to have decayed more slowly than average California sequences. Similarities can be drawn between the 1906 aftershock sequence and that of the 1857 (Mw 7.9) San Andreas fault earthquake.

Chapter 21. Composite shrubs

Treesearch

E. Durant McArthur; Richard Stevens

2004-01-01

The sunflower family (Compositae or Asteraceae) is the largest family of flowering plants. Its many species occur around the world as annual and perennial herbs and as shrubs and trees (Benson 1957; Cronquist 1968; Wagenitz 1977). Three shrubby genera of the family-sagebrush (Artemisia), rabbitbrush (Chrysothamnus), and matchbrush...

A New Connection Between Greenhouse Warming and Stratospheric Ozone Depletion

NASA Technical Reports Server (NTRS)

Salawitch, R.

1998-01-01

The direct radiative effects of the build-up of carbon dioxide and other greenhouse gases have led to a gradual cooling of the stratosphere with largest changes in temperature occurring in the upper stratosphere, well above the region of peak ozone concentration.

Computation of ground motion amplification in Kolkata megacity (India) using finite-difference method for seismic microzonation

NASA Astrophysics Data System (ADS)

Shiuly, Amit; Kumar, Vinay; Narayan, Jay

2014-06-01

This paper presents the ground motion amplification scenario along with fundamental frequency (F 0) of sedimentary deposit for the seismic microzonation of Kolkata City, situated on the world's largest delta island with very soft soil deposit. A 4th order accurate SH-wave viscoelastic finite-difference algorithm is used for computation of response of 1D model for each borehole location. Different maps, such as for F 0, amplification at F 0, average spectral amplification (ASA) in the different frequency bandwidth of earthquake engineering interest are developed for a variety of end-users communities. The obtained ASA of the order of 3-6 at most of the borehole locations in a frequency range of 0.25-10.0 Hz reveals that Kolkata City may suffer severe damage even during a moderate earthquake. Further, unexpected severe damage to collapse of multi-storey buildings may occur in localities near Hoogly River and Salt Lake area due to double resonance effects during distant large earthquakes.

Support surface related changes in feedforward and feedback control of standing posture

PubMed Central

Mohapatra, Sambit; Kukkar, Komal K.; Aruin, Alexander S.

2013-01-01

The aim of the study was to investigate the effect of different support surfaces on feedforward and feedback components of postural control. Nine healthy subjects were exposed to external perturbations applied to their shoulders while standing on a rigid platform, foam, and wobble board with eyes open or closed. Electrical activity of nine trunk and leg muscles and displacements of the center of pressure were recorded and analyzed during the time frames typical of feedforward and feedback postural adjustments. Feedforward control of posture was characterized by earlier activation of anterior muscles when the subjects stood on foam compared to a wobble board or a firm surface. In addition, the magnitude of feedforward muscle activity was the largest when the foam was used. During the feedback control, anterior muscles were activated prior to posterior muscles irrespective of the nature of surface. Moreover, the largest muscle activity was seen when the supporting surface was foam. Maximum CoP displacement occurred when subjects were standing on a rigid surface. Altering support surface affects both feedforward and feedback components of postural control. This information should be taken into consideration in planning rehabilitation interventions geared towards improvement of balance. PMID:24268589

Tropical Gravity Wave Momentum Fluxes and Latent Heating Distributions

NASA Technical Reports Server (NTRS)

Geller, Marvin A.; Zhou, Tiehan; Love, Peter T.

2015-01-01

Recent satellite determinations of global distributions of absolute gravity wave (GW) momentum fluxes in the lower stratosphere show maxima over the summer subtropical continents and little evidence of GW momentum fluxes associated with the intertropical convergence zone (ITCZ). This seems to be at odds with parameterizations forGWmomentum fluxes, where the source is a function of latent heating rates, which are largest in the region of the ITCZ in terms of monthly averages. The authors have examined global distributions of atmospheric latent heating, cloud-top-pressure altitudes, and lower-stratosphere absolute GW momentum fluxes and have found that monthly averages of the lower-stratosphere GW momentum fluxes more closely resemble the monthly mean cloud-top altitudes rather than the monthly mean rates of latent heating. These regions of highest cloud-top altitudes occur when rates of latent heating are largest on the time scale of cloud growth. This, plus previously published studies, suggests that convective sources for stratospheric GW momentum fluxes, being a function of the rate of latent heating, will require either a climate model to correctly model this rate of latent heating or some ad hoc adjustments to account for shortcomings in a climate model's land-sea differences in convective latent heating.

Support surface related changes in feedforward and feedback control of standing posture.

PubMed

Mohapatra, Sambit; Kukkar, Komal K; Aruin, Alexander S

2014-02-01

The aim of the study was to investigate the effect of different support surfaces on feedforward and feedback components of postural control. Nine healthy subjects were exposed to external perturbations applied to their shoulders while standing on a rigid platform, foam, and wobble board with eyes open or closed. Electrical activity of nine trunk and leg muscles and displacements of the center of pressure were recorded and analyzed during the time frames typical of feedforward and feedback postural adjustments. Feedforward control of posture was characterized by earlier activation of anterior muscles when the subjects stood on foam compared to a wobble board or a firm surface. In addition, the magnitude of feedforward muscle activity was the largest when the foam was used. During the feedback control, anterior muscles were activated prior to posterior muscles irrespective of the nature of surface. Moreover, the largest muscle activity was seen when the supporting surface was foam. Maximum CoP displacement occurred when subjects were standing on a rigid surface. Altering support surface affects both feedforward and feedback components of postural control. This information should be taken into consideration in planning rehabilitation interventions geared towards improvement of balance. Copyright © 2013 Elsevier Ltd. All rights reserved.

NASA's SDO Observes Largest Sunspot of the Solar Cycle

NASA Image and Video Library

2017-12-08

On Oct. 18, 2014, a sunspot rotated over the left side of the sun, and soon grew to be the largest active region seen in the current solar cycle, which began in 2008. Currently, the sunspot is almost 80,000 miles across -- ten Earth's could be laid across its diameter. Sunspots point to relatively cooler areas on the sun with intense and complex magnetic fields poking out through the sun's surface. Such areas can be the source of solar eruptions such as flares or coronal mass ejections. So far, this active region – labeled AR 12192 -- has produced several significant solar flares: an X-class flare on Oct. 19, an M-class flare on Oct. 21, and an X-class flare on Oct. 22, 2014. The largest sunspot on record occurred in 1947 and was almost three times as large as the current one. Active regions are more common at the moment as we are in what's called solar maximum, which is the peak of the sun's activity, occurring approximately every 11 years. Credit: NASA/SDO NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Assessment of soil and water contaminants from selected locations in and near the Idaho Army National Guard Orchard Training Area, Ada County, Idaho, 2001-2003

USGS Publications Warehouse

Parliman, D.J.

2004-01-01

In 2001, the National Guard Bureau and the U.S. Geological Survey began a project to compile hydrogeologic data and determine presence or absence of soil, surface-water, and ground-water contamination at the Idaho Army National Guard Orchard Training Area in southwestern Idaho. Between June 2002 and April 2003, a total of 114 soil, surface-water, ground-water, precipitation, or dust samples were collected from 68 sample sites (65 different locations) in the Orchard Training Area (OTA) or along the vehicle corridor to the OTA. Soil and water samples were analyzed for concentrations of selected total trace metals, major ions, nutrients, explosive compounds, semivolatile organics, and petroleum hydrocarbons. Water samples also were analyzed for concentrations of selected dissolved trace metals and major ions. Distinguishing naturally occurring large concentrations of trace metals, major ions, and nutrients from contamination related to land and water uses at the OTA was difficult. There were no historical analyses for this area to compare with modern data, and although samples were collected from 65 locations in and near the OTA, sampled areas represented only a small part of the complex OTA land-use areas and soil types. For naturally occurring compounds, several assumptions were made?anomalously large concentrations, when tied to known land uses, may indicate presence of contamination; naturally occurring concentrations cannot be separated from contamination concentrations in mid- and lower ranges of data; and smallest concentrations may represent the lowest naturally occurring range of concentrations and (or) the absence of contaminants related to land and water uses. Presence of explosive, semivolatile organic (SVOC), and petroleum hydrocarbon compounds in samples indicates contamination from land and water uses. In areas along the vehicle corridor and major access roads within the OTA, most trace metal, major ion, and nutrient concentrations in soil samples were not in the upper 10th percentile of data, but concentrations of 25 metals, ions, or nutrients were in the upper 10th percentile in a puddle sample near the heavy equipment maneuvering area, MPRC-H. The largest concentrations of tin, ammonia, and nitrite plus nitrate (as nitrogen) in water from the OTA were detected in a sample from this puddle. Petroleum hydrocarbons were the most common contaminant, detected in all soil and surface-water samples. An SVOC, bis (2-ethylhexyl) phthalate, a plasticizer, was detected at a site along the vehicle corridor. In Maneuver Areas within the OTA, many soil samples contained at least one trace metal, major ion, or nutrient in the upper 10th percentile of data, and the largest concentrations of cobalt, iron, mercury, titanium, sodium, ammonia, or total phosphorus were detected in 6 of 13 soil samples outside the Tadpole Lake area. The largest concentrations of aluminum, arsenic, beryllium, nickel, selenium, silver, strontium, thallium, vanadium, chloride, potassium, sulfate, and nitrite plus nitrate were detected in soil samples from the Tadpole Lake area. Water from Tadpole Lake contained the largest total concentrations of 19 trace metals, 4 major ions, and 1 nutrient. Petroleum hydrocarbons were detected in 5 soil samples and water from Tadpole Lake. SVOCs related to combustion of fuel or plasticizers were detected in 1 soil sample. Explosive compounds were detected in 1 precipitation sample.In the Impact Area within the OTA, most soil samples contained at least one trace metal, major ion, or nutrient in the upper 10th percentile of data, and the largest concentrations of barium, chromium, copper, manganese, lead, or orthophosphate were detected in 6 of the 18 soil samples. Petroleum hydrocarbons were detected in 4 soil samples, SVOCs in 6 samples, and explosive compounds in 4 samples. In the mobilization and training equipment site (MATES) compound adjacent to the OTA, all soil and water samples contained at lea

Variations in pore characteristics in high volatile bituminous coals: Implications for coal bed gas content

USGS Publications Warehouse

Mastalerz, Maria; Drobniak, A.; Strapoc, D.; Solano-Acosta, W.; Rupp, J.

2008-01-01

The Seelyville Coal Member of the Linton Formation (Pennsylvanian) in Indiana was studied to: 1) understand variations in pore characteristics within a coal seam at a single location and compare these variations with changes occurring between the same coal at different locations, 2) elaborate on the influence of mineral-matter and maceral composition on mesopore and micropore characteristics, and 3) discuss implications of these variations for coal bed gas content. The coal is high volatile bituminous rank with R0 ranging from 0.57% to 0.60%. BET specific surface areas (determined by nitrogen adsorption) of the coals samples studied range from 1.8 to 22.9??m2/g, BJH adsorption mesopore volumes from 0.0041 to 0.0339??cm3/g, and micropore volumes (determined by carbon dioxide adsorption) from 0.0315 to 0.0540??cm3/g. The coals that had the largest specific surface areas and largest mesopore volumes occur at the shallowest depths, whereas the smallest values for these two parameters occur in the deepest coals. Micropore volumes, in contrast, are not depth-dependent. In the coal samples examined for this study, mineral-matter content influenced both specific surface area as well as mesopore and micropore volumes. It is especially clear in the case of micropores, where an increase in mineral-matter content parallels the decrease of micropore volume of the coal. No obvious relationships were observed between the total vitrinite content and pore characteristics but, after splitting vitrinite into individual macerals, we see that collotelinite influences both meso- and micropore volume positively, whereas collodetrinite contributes to the reduction of mesopore and micropore volumes. There are large variations in gas content within a single coal at a single location. Because of this variability, the entire thickness of the coal must be desorbed in order to determine gas content reliably and to accurately calculate the level of gas saturation. ?? 2008 Elsevier B.V. All rights reserved.

The seasonality and geographic dependence of ENSO impacts on U.S. surface ozone variability

NASA Astrophysics Data System (ADS)

Xu, Li; Yu, Jin-Yi; Schnell, Jordan L.; Prather, Michael J.

2017-04-01

We examine the impact of El Niño-Southern Oscillation (ENSO) on surface ozone abundance observed over the continental United States (U.S.) during 1993-2013. The monthly ozone decreases (increases) during El Niño (La Niña) years with amplitude up to 1.8 ppb per standard deviation of Niño 3.4 index. The largest ENSO influences occur over two southern U.S. regions during fall when the ENSO develops and over two western U.S. regions during the winter to spring after the ENSO decays. ENSO affects surface ozone via chemical processes during warm seasons in southern regions, where favorable meteorological conditions occur, but via dynamic transport during cold seasons in western regions, where the ENSO-induced circulation variations are large. The geographic dependence and seasonality of the ENSO impacts imply that regulations regarding air quality and its exceedance need to be adjusted for different seasons and U.S. regions to account for the ENSO-driven patterns in surface ozone.

Large allele frequency differences between human continental groups are more likely to have occurred by drift during range expansions than by selection.

PubMed

Hofer, T; Ray, N; Wegmann, D; Excoffier, L

2009-01-01

Several studies have found strikingly different allele frequencies between continents. This has been mainly interpreted as being due to local adaptation. However, demographic factors can generate similar patterns. Namely, allelic surfing during a population range expansion may increase the frequency of alleles in newly colonised areas. In this study, we examined 772 STRs, 210 diallelic indels, and 2834 SNPs typed in 53 human populations worldwide under the HGDP-CEPH Diversity Panel to determine to which extent allele frequency differs among four regions (Africa, Eurasia, East Asia, and America). We find that large allele frequency differences between continents are surprisingly common, and that Africa and America show the largest number of loci with extreme frequency differences. Moreover, more STR alleles have increased rather than decreased in frequency outside Africa, as expected under allelic surfing. Finally, there is no relationship between the extent of allele frequency differences and proximity to genes, as would be expected under selection. We therefore conclude that most of the observed large allele frequency differences between continents result from demography rather than from positive selection.

Lanzarote, Canary Islands

NASA Image and Video Library

2017-01-06

Lanzarote is the easternmost of the Canary Islands, 125 km off the coast of Africa, and is the fourth largest of the archipelago, with an area of 846 square kilometers. Like all of the Canary Islands, its volcanic origin dates to about 15 million years ago. The largest historic eruption occurred in the 1730s. The island was first recorded by Pliny the Elder, though it may have been originally settled by the Phoenicians (Wikipedia). The image was acquired 12 March 2015, covers an area of 50.5 by 55.1 km, and is located near 29 degrees north, 13.6 degrees west. http://photojournal.jpl.nasa.gov/catalog/PIA21284

Goldstrike Mine, Nevada

NASA Image and Video Library

2017-05-15

This image from NASA Terra spacecraft shows Goldstrike in northeast Nevada, the largest gold mine in North America. The mine complex, (including the Betze-Post-Screamer open-pit, and Meikle and Rodeo underground mines) is owned and operated by the world's largest gold mining company, Barrick Gold. Gold occurs as microscopically fine grains, with an average grade of 0.1 ounces per ton of ore. Estimates of reserves are as high as 35 million ounces of gold. The image was acquired September 25, 2010, covers an area of 15 by 15 km, and is located at 41 degrees north, 116.4 degrees west. https://photojournal.jpl.nasa.gov/catalog/PIA21665

Decades of urban growth and development on the Asian megadeltas

NASA Astrophysics Data System (ADS)

Small, Christopher; Sousa, Daniel; Yetman, Gregory; Elvidge, Christopher; MacManus, Kytt

2018-06-01

The current and ongoing expansion of urban areas worldwide represents the largest mass migration in human history. It is well known that the world's coastal zones are associated with large and growing concentrations of population, urban development and economic activity. Among coastal environments, deltas have long been recognized for both benefits and hazards. This is particularly true on the Asian megadeltas, where the majority of the world's deltaic populations reside. Current trends in urban migration, combined with demographic momentum suggest that the already large populations on the Asian megadeltas will continue to grow. In this study, we combine recently released gridded population density (circa 2010) with a newly developed night light change product (1992 to 2012) and a digital elevation model to quantify the spatial distribution of population and development on the nine Asian megadeltas. Bivariate distributions of population as functions of elevation and coastal proximity quantify potential exposure of deltaic populations to flood and coastal hazards. Comparison of these distributions for the Asian megadeltas show very different patterns of habitation with peak population elevations ranging from 2 to 11 m above sea level over a wide range of coastal proximities. Over all nine megadeltas, over 174 million people reside below a peak population elevation of 7 m. Changes in the spatial extent of anthropogenic night light from 1992 to 2012 show widely varying extents and changes of lighted urban development. All of the deltas except the Indus show the greatest increases in night light brightness occurring at elevations <10 m. At global and continental scales, growth of settlements of all sizes takes the form of evolving spatial networks of development. Spatial networks of lighted urban development in Asia show power law scaling properties consistent with other continents, but much higher rates of growth. The three largest networks of development in China all occur on deltas and adjacent lowlands, and are growing faster than the rest of the urban network in China. Since 2000, the Huanghe Delta + North China Plain urban network has surpassed the Japanese urban network in size and may soon connect with the Changjiang Delta + Yangtze River urban network to form the largest conurbation in Asia.

Some potential hazardous trace elements contamination and their ecological risk in sediments of western Chaohu Lake, China.

PubMed

Zheng, Liu-Gen; Liu, Gui-Jian; Kang, Yu; Yang, Ren-Kang

2010-07-01

The Chaohu is one of the largest five freshwater lakes in China. It provides freshwater for agriculture, life, and part of industry. The quality of water becomes worst and worst due to the toxic matter. In this study, we collected the samples from the sedimentary mud in the lake. The distribution of some potential hazardous trace elements (Cu, Ni, Cr, As, Pb, Cd, and Hg) in the sediments of western Chaohu Lake, has been determined and studied, and the enrichment factors, the index of geoaccumulation, and potential ecological risk were analyzed and calculated. The results show that: the levels of selected potential hazardous trace element vary from different sampling sites and significant anthropogenic impact of Pb and Cd occur in sediments. The contamination rank of Pb and Cd are moderate, and Pb has a light potential ecological risk, but Cd is heavy. The total potential ecological risk of the selected hazardous trace elements in this study in Chaohu Lake is moderate. Cluster and correlation analysis indicate that the selected potential hazardous trace element pollutant has different source and co-contamination also occur in sediments.

On the evolution of specialization with a mechanistic underpinning in structured metapopulations.

PubMed

Nurmi, Tuomas; Parvinen, Kalle

2008-03-01

We analyze the evolution of specialization in resource utilization in a discrete-time metapopulation model using the adaptive dynamics approach. The local dynamics in the metapopulation are based on the Beverton-Holt model with mechanistic underpinnings. The consumer faces a trade-off in the abilities to consume two resources that are spatially heterogeneously distributed to patches that are prone to local catastrophes. We explore the factors favoring the spread of generalist or specialist strategies. Increasing fecundity or decreasing catastrophe probability favors the spread of the generalist strategy and increasing environmental heterogeneity enlarges the parameter domain where the evolutionary branching is possible. When there are no catastrophes, increasing emigration diminishes the parameter domain where the evolutionary branching may occur. Otherwise, the effect of emigration on evolutionary dynamics is non-monotonous: both small and large values of emigration probability favor the spread of the specialist strategies whereas the parameter domain where evolutionary branching may occur is largest when the emigration probability has intermediate values. We compare how different forms of spatial heterogeneity and different models of local growth affect the evolutionary dynamics. We show that even small changes in the resource dynamics may have outstanding evolutionary effects to the consumers.

Outbreak of acute hypoglycemic encephalopathy associated with litchi consumption, Muzaffarpur, India, 2014

USDA-ARS?s Scientific Manuscript database

Background: Seasonal outbreaks of an acute neurologic illness with high mortality among young children occur annually in Muzaffarpur, Bihar, the largest litchi (lychee) fruit cultivation region in India. A wide range of infectious and non-infectious etiologies, including an association with litchi...

Dengue Virus 1 Outbreak in Buenos Aires, Argentina, 2016.

PubMed

Tittarelli, Estefanía; Lusso, Silvina B; Goya, Stephanie; Rojo, Gabriel L; Natale, Mónica I; Viegas, Mariana; Mistchenko, Alicia S; Valinotto, Laura E

2017-10-01

The largest outbreak of dengue in Buenos Aires, Argentina, occurred during 2016. Phylogenetic, phylodynamic, and phylogeographic analyses of 82 samples from dengue patients revealed co-circulation of 2 genotype V dengue virus lineages, suggesting that this virus has become endemic to the Buenos Aires metropolitan area.

Modelling average maximum daily temperature using r largest order statistics: An application to South African data

PubMed Central

2018-01-01

Natural hazards (events that may cause actual disasters) are established in the literature as major causes of various massive and destructive problems worldwide. The occurrences of earthquakes, floods and heat waves affect millions of people through several impacts. These include cases of hospitalisation, loss of lives and economic challenges. The focus of this study was on the risk reduction of the disasters that occur because of extremely high temperatures and heat waves. Modelling average maximum daily temperature (AMDT) guards against the disaster risk and may also help countries towards preparing for extreme heat. This study discusses the use of the r largest order statistics approach of extreme value theory towards modelling AMDT over the period of 11 years, that is, 2000–2010. A generalised extreme value distribution for r largest order statistics is fitted to the annual maxima. This is performed in an effort to study the behaviour of the r largest order statistics. The method of maximum likelihood is used in estimating the target parameters and the frequency of occurrences of the hottest days is assessed. The study presents a case study of South Africa in which the data for the non-winter season (September–April of each year) are used. The meteorological data used are the AMDT that are collected by the South African Weather Service and provided by Eskom. The estimation of the shape parameter reveals evidence of a Weibull class as an appropriate distribution for modelling AMDT in South Africa. The extreme quantiles for specified return periods are estimated using the quantile function and the best model is chosen through the use of the deviance statistic with the support of the graphical diagnostic tools. The Entropy Difference Test (EDT) is used as a specification test for diagnosing the fit of the models to the data.

Cumulative Damage in Strength-Dominated Collisions of Rocky Asteroids: Rubble Piles and Brick Piles

NASA Technical Reports Server (NTRS)

Housen, Kevin

2009-01-01

Laboratory impact experiments were performed to investigate the conditions that produce large-scale damage in rock targets. Aluminum cylinders (6.3 mm diameter) impacted basalt cylinders (69 mm diameter) at speeds ranging from 0.7 to 2.0 km/s. Diagnostics included measurements of the largest fragment mass, velocities of the largest remnant and large fragments ejected from the periphery of the target, and X-ray computed tomography imaging to inspect some of the impacted targets for internal damage. Significant damage to the target occurred when the kinetic energy per unit target mass exceeded roughly 1/4 of the energy required for catastrophic shattering (where the target is reduced to one-half its original mass). Scaling laws based on a rate-dependent strength were developed that provide a basis for extrapolating the results to larger strength-dominated collisions. The threshold specific energy for widespread damage was found to scale with event size in the same manner as that for catastrophic shattering. Therefore, the factor of four difference between the two thresholds observed in the lab also applies to larger collisions. The scaling laws showed that for a sequence of collisions that are similar in that they produce the same ratio of largest fragment mass to original target mass, the fragment velocities decrease with increasing event size. As a result, rocky asteroids a couple hundred meters in diameter should retain their large ejecta fragments in a jumbled rubble-pile state. For somewhat larger bodies, the ejection velocities are sufficiently low that large fragments are essentially retained in place, possibly forming ordered "brick-pile" structures.

Update: mumps outbreak - New York and New Jersey, June 2009-January 2010.

PubMed

2010-02-12

State and local health departments, in collaboration with CDC, continue to investigate a mumps outbreak that began in New York in June 2009. The index case occurred in a boy aged 11 years who had returned on June 17 from a trip to the United Kingdom, where approximately 7,400 reports of laboratory-confirmed mumps were received by the Health Protection Agency in 2009. He then attended a New York summer camp for tradition-observant Jewish boys, where he became symptomatic on June 28. Subsequently, other camp attendees and a staff member were reported to have mumps, and transmission continued in multiple locations when the camp attendees returned home. As of January 29, 2010, a total of 1,521 cases had been reported, with onset dates from June 28, 2009, through January 29, 2010, a substantial increase from the 179 cases reported as of October 30, 2009. The outbreak has remained confined primarily to the tradition-observant Jewish community, with <3% of cases occurring among persons outside the community. The largest percentage of cases (61%) has occurred among persons aged 7-18 years, and 76% of the patients are male. Among the patients for whom vaccination status was reported, 88% had received at least 1 dose of mumps-containing vaccine, and 75% had received 2 doses. This is the largest mumps outbreak that has occurred in the United States since 2006. Although mumps vaccination alone was not sufficient to prevent this outbreak, maintaining high measles, mumps, and rubella (MMR) vaccination coverage remains the most effective way to prevent outbreaks and limit their size when they occur.

Cortical and Subcortical Brain Morphometry Differences Between Patients With Autism Spectrum Disorder and Healthy Individuals Across the Lifespan: Results From the ENIGMA ASD Working Group.

PubMed

van Rooij, Daan; Anagnostou, Evdokia; Arango, Celso; Auzias, Guillaume; Behrmann, Marlene; Busatto, Geraldo F; Calderoni, Sara; Daly, Eileen; Deruelle, Christine; Di Martino, Adriana; Dinstein, Ilan; Duran, Fabio Luis Souza; Durston, Sarah; Ecker, Christine; Fair, Damien; Fedor, Jennifer; Fitzgerald, Jackie; Freitag, Christine M; Gallagher, Louise; Gori, Ilaria; Haar, Shlomi; Hoekstra, Liesbeth; Jahanshad, Neda; Jalbrzikowski, Maria; Janssen, Joost; Lerch, Jason; Luna, Beatriz; Martinho, Mauricio Moller; McGrath, Jane; Muratori, Filippo; Murphy, Clodagh M; Murphy, Declan G M; O'Hearn, Kirsten; Oranje, Bob; Parellada, Mara; Retico, Alessandra; Rosa, Pedro; Rubia, Katya; Shook, Devon; Taylor, Margot; Thompson, Paul M; Tosetti, Michela; Wallace, Gregory L; Zhou, Fengfeng; Buitelaar, Jan K

2018-04-01

Neuroimaging studies show structural differences in both cortical and subcortical brain regions in children and adults with autism spectrum disorder (ASD) compared with healthy subjects. Findings are inconsistent, however, and it is unclear how differences develop across the lifespan. The authors investigated brain morphometry differences between individuals with ASD and healthy subjects, cross-sectionally across the lifespan, in a large multinational sample from the Enhancing Neuroimaging Genetics Through Meta-Analysis (ENIGMA) ASD working group. The sample comprised 1,571 patients with ASD and 1,651 healthy control subjects (age range, 2-64 years) from 49 participating sites. MRI scans were preprocessed at individual sites with a harmonized protocol based on a validated automated-segmentation software program. Mega-analyses were used to test for case-control differences in subcortical volumes, cortical thickness, and surface area. Development of brain morphometry over the lifespan was modeled using a fractional polynomial approach. The case-control mega-analysis demonstrated that ASD was associated with smaller subcortical volumes of the pallidum, putamen, amygdala, and nucleus accumbens (effect sizes [Cohen's d], 0.13 to -0.13), as well as increased cortical thickness in the frontal cortex and decreased thickness in the temporal cortex (effect sizes, -0.21 to 0.20). Analyses of age effects indicate that the development of cortical thickness is altered in ASD, with the largest differences occurring around adolescence. No age-by-ASD interactions were observed in the subcortical partitions. The ENIGMA ASD working group provides the largest study of brain morphometry differences in ASD to date, using a well-established, validated, publicly available analysis pipeline. ASD patients showed altered morphometry in the cognitive and affective parts of the striatum, frontal cortex, and temporal cortex. Complex developmental trajectories were observed for the different regions, with a developmental peak around adolescence. These findings suggest an interplay in the abnormal development of the striatal, frontal, and temporal regions in ASD across the lifespan.

The Multivariate Largest Lyapunov Exponent as an Age-Related Metric of Quiet Standing Balance

PubMed Central

Liu, Kun; Wang, Hongrui; Xiao, Jinzhuang

2015-01-01

The largest Lyapunov exponent has been researched as a metric of the balance ability during human quiet standing. However, the sensitivity and accuracy of this measurement method are not good enough for clinical use. The present research proposes a metric of the human body's standing balance ability based on the multivariate largest Lyapunov exponent which can quantify the human standing balance. The dynamic multivariate time series of ankle, knee, and hip were measured by multiple electrical goniometers. Thirty-six normal people of different ages participated in the test. With acquired data, the multivariate largest Lyapunov exponent was calculated. Finally, the results of the proposed approach were analysed and compared with the traditional method, for which the largest Lyapunov exponent and power spectral density from the centre of pressure were also calculated. The following conclusions can be obtained. The multivariate largest Lyapunov exponent has a higher degree of differentiation in differentiating balance in eyes-closed conditions. The MLLE value reflects the overall coordination between multisegment movements. Individuals of different ages can be distinguished by their MLLE values. The standing stability of human is reduced with the increment of age. PMID:26064182

Patagonian and southern South Atlantic view of Holocene climate

NASA Astrophysics Data System (ADS)

Kaplan, M. R.; Schaefer, J. M.; Strelin, J. A.; Denton, G. H.; Anderson, R. F.; Vandergoes, M. J.; Finkel, R. C.; Schwartz, R.; Travis, S. G.; Garcia, J. L.; Martini, M. A.; Nielsen, S. H. H.

2016-06-01

We present a comprehensive 10Be chronology for Holocene moraines in the Lago Argentino basin, on the east side of the South Patagonian Icefield. We focus on three different areas, where prior studies show ample glacier moraine records exist because they were formed by outlet glaciers sensitive to climate change. The 10Be dated records are from the Lago Pearson, Herminita Península-Brazo Upsala, and Lago Frías areas, which span a distance of almost 100 km adjacent to the modern Icefield. New 10Be ages show that expanded glaciers and moraine building events occurred at least at 6120 ± 390 (n = 13), 4450 ± 220 (n = 7), 1450 or 1410 ± 110 (n = 18), 360 ± 30 (n = 5), and 240 ± 20 (n = 8) years ago. Furthermore, other less well-dated glacier expansions of the Upsala Glacier occurred between 1400 and ∼1000 and ∼2300 and ∼2000 years ago. The most extensive glaciers occurred over the interval from ∼6100 to ∼4500 years ago, and their margins over the last ∼600 years were well within and lower than those in the middle Holocene. The 10Be ages agree with 14C-limiting data for the glacier histories in this area. We then link southern South American, adjacent South Atlantic, and other Southern Hemisphere records to elucidate broader regional patterns of climate and their possible causes. In the early Holocene, a far southward position of the westerly winds fostered warmth, small Patagonian glaciers, and reduced sea ice coverage over the South Atlantic. Although we infer a pronounced southward displacement of the westerlies during the early Holocene, these conditions did not occur throughout the southern mid-high latitudes, an important exception being over the southwest Pacific sector. Subsequently, a northward locus and/or expansion of the winds over the Patagonia-South Atlantic sector promoted the largest glaciers between ∼6100 and ∼4500 years ago and greatest sea ice coverage. Over the last few millennia, the South Patagonian Icefield has experienced successive century-scale advances superimposed on a long-term net decrease in size. Our findings indicate that glaciers and sea ice in the Patagonian-South Atlantic sector of the Southern Hemisphere did not achieve their largest Holocene extents over the last millennium. We conclude that a pattern of more extensive Holocene ice prior to the last millennium is characteristic of the Southern Hemisphere middle latitudes, which differs from the glacier history traditionally thought for the Northern Hemisphere.

KRAS mutations: variable incidences in a Brazilian cohort of 8,234 metastatic colorectal cancer patients

PubMed Central

2014-01-01

Background KRAS mutations are frequently found in colorectal cancer (CRC) indicating the importance of its genotyping in the study of the molecular mechanisms behind this disease. Although major advances have occurred over the past decade, there are still important gaps in our understanding of CRC carcinogenesis, particularly whether sex-linked factors play any role. Methods The profile of KRAS mutations in the Brazilian population was analyzed by conducting direct sequencing of KRAS codons 12 and 13 belonging to 8,234 metastatic CRC patient samples. DNA was extracted from paraffin-embedded tissue, exon 1 was amplified by PCR and submitted to direct sequencing. The data obtained was analysed comparing different geographical regions, gender and age. Results The median age was 59 years and the overall percentage of wild-type and mutated KRAS was 62.8% and 31.9%, respectively. Interestingly, different percentages of mutated KRAS patients were observed between male and female patients (32.5% versus 34.8%, respectively; p = 0.03). KRAS Gly12Asp mutation was the most prevalent for both genders and for most regions, with the exception of the North where Gly12Val was the most frequent mutation found. Conclusions To the best of our knowledge this is one of the largest cohorts of KRAS genotyping in CRC patients and the largest to indicate a higher incidence of KRAS mutation in females compared to males in Brazil. Nevertheless, further research is required to better address the impact of gender differences in colorectal cancer. PMID:24720724

Tree species affect cation exchange capacity (CEC) and cation binding properties of organic matter in acid forest soils.

PubMed

Gruba, Piotr; Mulder, Jan

2015-04-01

Soil organic matter (SOM) in forest soil is of major importance for cation binding and acid buffering, but its characteristics may differ among soils under different tree species. We investigated acidity, cation exchange properties and Al bonding to SOM in stands of Scots pine, pedunculate oak, Norway spruce, European beech and common hornbeam in southern Poland. The content of total carbon (Ct) was by far the major contributor to total cation exchange capacity (CECt) even in loamy soils and a strong relationship between Ct and CECt was found. The slope of the regression of CECt to Ct increased in the order hornbeam≈oak

Triennial Growth Symposium: effects of polymeric carbohydrates on growth and development in pigs.

PubMed

Bach Knudsen, K E

2011-07-01

Polymeric carbohydrates, starch and nonstarch polysaccharides (NSP), quantitatively represent the largest portion of the diets for pigs and are, therefore, the largest energy contributor. The 2 types of polysaccharides, however, have different fates and functions in the gastrointestinal tract and lead to different metabolites upon digestion. Pancreatic and mucosal enzymes in the small intestine break down the majority of starch, whereas NSP primarily are degraded by the microflora in the large intestine. Starch degradation leads to the release of glucose, which is absorbed by an active absorption process that triggers the release of insulin from the pancreas, whereas the fermentation of NSP to short-chain fatty acids (SCFA; i.e., acetate, propionate, and butyrate) occurs at a slower and more constant rate and with SCFA being absorbed by passive diffusion. Type and amounts of polymeric carbohydrates influence growth and development through different mechanisms. First, the proportion of starch to NSP plays an important role for the content of available energy (i.e., DE, ME, and NE); available energy relative to protein is crucial for performance and carcass quality. Second, the proportion of starch to NSP will influence rate and type of metabolites (i.e., glucose vs. SCFA) deriving from carbohydrate assimilation. Third and finally, the type of starch (i.e., types A, B, and C) and soluble NSP will influence the release of insulin, the hormone that facilitates nutrient uptake by tissues, organs, and cells, and thus plays a critically essential role in protein synthesis and muscle growth, as well as lipid synthesis and adipose tissue growth. In conclusion, polymeric carbohydrates influence growth and development through events in the gut and direct and indirect effects of different metabolites deriving from carbohydrate assimilation. © 2011 American Society of Animal Science. All rights reserved.

Entropic effects in the electric double layer of model colloids with size-asymmetric monovalent ions

NASA Astrophysics Data System (ADS)

Guerrero-García, Guillermo Iván; González-Tovar, Enrique; Olvera de la Cruz, Mónica

2011-08-01

The structure of the electric double layer of charged nanoparticles and colloids in monovalent salts is crucial to determine their thermodynamics, solubility, and polyion adsorption. In this work, we explore the double layer structure and the possibility of charge reversal in relation to the size of both counterions and coions. We examine systems with various size-ratios between counterions and coions (ion size asymmetries) as well as different total ion volume fractions. Using Monte Carlo simulations and integral equations of a primitive-model electric double layer, we determine the highest charge neutralization and electrostatic screening near the electrified surface. Specifically, for two binary monovalent electrolytes with the same counterion properties but differing only in the coion's size surrounding a charged nanoparticle, the one with largest coion size is found to have the largest charge neutralization and screening. That is, in size-asymmetric double layers with a given counterion's size the excluded volume of the coions dictates the adsorption of the ionic charge close to the colloidal surface for monovalent salts. Furthermore, we demonstrate that charge reversal can occur at low surface charge densities, given a large enough total ion concentration, for systems of monovalent salts in a wide range of ion size asymmetries. In addition, we find a non-monotonic behavior for the corresponding maximum charge reversal, as a function of the colloidal bare charge. We also find that the reversal effect disappears for binary salts with large-size counterions and small-size coions at high surface charge densities. Lastly, we observe a good agreement between results from both Monte Carlo simulations and the integral equation theory across different colloidal charge densities and 1:1-elec-trolytes with different ion sizes.

Torvosaurus gurneyi n. sp., the Largest Terrestrial Predator from Europe, and a Proposed Terminology of the Maxilla Anatomy in Nonavian Theropods

PubMed Central

Hendrickx, Christophe; Mateus, Octávio

2014-01-01

The Lourinhã Formation (Kimmeridgian-Tithonian) of Central West Portugal is well known for its diversified dinosaur fauna similar to that of the Morrison Formation of North America; both areas share dinosaur taxa including the top predator Torvosaurus, reported in Portugal. The material assigned to the Portuguese T. tanneri, consisting of a right maxilla and an incomplete caudal centrum, was briefly described in the literature and a thorough description of these bones is here given for the first time. A comparison with material referred to Torvosaurus tanneri allows us to highlight some important differences justifying the creation of a distinct Eastern species. Torvosaurus gurneyi n. sp. displays two autapomorphies among Megalosauroidea, a maxilla possessing fewer than eleven teeth and an interdental wall nearly coincidental with the lateral wall of the maxillary body. In addition, it differs from T. tanneri by a reduced number of maxillary teeth, the absence of interdental plates terminating ventrally by broad V-shaped points and falling short relative to the lateral maxillary wall, and the absence of a protuberant ridge on the anterior part of the medial shelf, posterior to the anteromedial process. T. gurneyi is the largest theropod from the Lourinhã Formation of Portugal and the largest land predator discovered in Europe hitherto. This taxon supports the mechanism of vicariance that occurred in the Iberian Meseta during the Late Jurassic when the proto-Atlantic was already well formed. A fragment of maxilla from the Lourinhã Formation referred to Torvosaurus sp. is ascribed to this new species, and several other bones, including a femur, a tibia and embryonic material all from the Kimmeridgian-Tithonian of Portugal, are tentatively assigned to T. gurneyi. A standard terminology and notation of the theropod maxilla is also proposed and a record of the Torvosaurus material from Portugal is given. PMID:24598585

Regional Highlights of Climate Change

Treesearch

David L. Peterson; J.M. Wolken; Teresa Hollingsworth; Christian Giardina; J.S. Littell; Linda Joyce; Chris Swanston; Stephen Handler; Lindsey Rustad; Steve McNulty

2014-01-01

Climatic extremes, ecological disturbance, and their interactions are expected to have major effects on ecosystems and social systems in most regions of the United States in the coming decades. In Alaska, where the largest temperature increases have occurred, permafrost is melting, carbon is being released, and fire regimes are changing, leading to a...

Use of glucose oxidase to improve refrigerated dough quality

USDA-ARS?s Scientific Manuscript database

Refrigerated dough encompasses a wide range of products including bread, rolls, pastries and pizza crust and is a very popular choice for consumers. Two of the largest problems that occur during refrigerated dough storage are dough syruping and loss of dough strength. The goal of this study was to e...

Repeated Acquisitions and Extinctions in Classical Conditioning of the Rabbit Nictitating Membrane Response

ERIC Educational Resources Information Center

Kehoe, E. James

2006-01-01

The rabbit nictitating membrane (NM) response underwent successive stages of acquisition and extinction training in both delay (Experiment 1) and trace (Experiment 2) classical conditioning. In both cases, successive acquisitions became progressively faster, although the largest, most reliable acceleration occurred between the first and second…

Bark beetles in a changing climate

Treesearch

John E. Lundquist; Barbara J. Bentz

2009-01-01

Over the past decade, native bark beetles (Coleoptera: Curculionidae) have killed billions of trees across millions of hectares of forest from Alaska to Mexico. Although bark beetle infestations are a regular force of natural change in forested ecosystems, several current outbreaks occurring simultaneously across western North America are the largest and most...

A free flight investigation of transonic sting interference

NASA Technical Reports Server (NTRS)

Jaffe, P.

1975-01-01

Transonic sting interference has been studied in a supersonic wind tunnel to obtain free flight and sting support data on identical models. The two principal configurations, representing fuselage bodies, were cigar shaped with tail fins. The others were a sharp 10-deg cone, a sphere, and a blunt entry body. Comparative data indicated that the sting had an appreciable effect on drag for the fuselage-like configurations; drag rise occurred 0.02 Mach number earlier in free flight, and drag level was 15% greater. The spheres and the blunt bodies were insensitive to the presence of stings regardless of their size. The 10-deg cones were in between, experiencing no drag difference with a minimum diameter sting, but a moderate difference with the largest diameter sting tested. All data tend to confirm the notion that for the more slender bodies the sting not only affects flow but the forebody flow as well.

Nuclear energy release from fragmentation

NASA Astrophysics Data System (ADS)

Li, Cheng; Souza, S. R.; Tsang, M. B.; Zhang, Feng-Shou

2016-08-01

It is well known that binary fission occurs with positive energy gain. In this article we examine the energetics of splitting uranium and thorium isotopes into various numbers of fragments (from two to eight) with nearly equal size. We find that the energy released by splitting 230,232Th and 235,238U into three equal size fragments is largest. The statistical multifragmentation model (SMM) is applied to calculate the probability of different breakup channels for excited nuclei. By weighing the probability distributions of fragment multiplicity at different excitation energies, we find the peaks of energy release for 230,232Th and 235,238U are around 0.7-0.75 MeV/u at excitation energy between 1.2 and 2 MeV/u in the primary breakup process. Taking into account the secondary de-excitation processes of primary fragments with the GEMINI code, these energy peaks fall to about 0.45 MeV/u.

Endoplasmic Reticulum: The Favorite Intracellular Niche for Viral Replication and Assembly.

PubMed

Romero-Brey, Inés; Bartenschlager, Ralf

2016-06-07

The endoplasmic reticulum (ER) is the largest intracellular organelle. It forms a complex network of continuous sheets and tubules, extending from the nuclear envelope (NE) to the plasma membrane. This network is frequently perturbed by positive-strand RNA viruses utilizing the ER to create membranous replication factories (RFs), where amplification of their genomes occurs. In addition, many enveloped viruses assemble progeny virions in association with ER membranes, and viruses replicating in the nucleus need to overcome the NE barrier, requiring transient changes of the NE morphology. This review first summarizes some key aspects of ER morphology and then focuses on the exploitation of the ER by viruses for the sake of promoting the different steps of their replication cycles.

Endoplasmic Reticulum: The Favorite Intracellular Niche for Viral Replication and Assembly

PubMed Central

Romero-Brey, Inés; Bartenschlager, Ralf

2016-01-01

The endoplasmic reticulum (ER) is the largest intracellular organelle. It forms a complex network of continuous sheets and tubules, extending from the nuclear envelope (NE) to the plasma membrane. This network is frequently perturbed by positive-strand RNA viruses utilizing the ER to create membranous replication factories (RFs), where amplification of their genomes occurs. In addition, many enveloped viruses assemble progeny virions in association with ER membranes, and viruses replicating in the nucleus need to overcome the NE barrier, requiring transient changes of the NE morphology. This review first summarizes some key aspects of ER morphology and then focuses on the exploitation of the ER by viruses for the sake of promoting the different steps of their replication cycles. PMID:27338443

Joule heating at high latitudes

NASA Technical Reports Server (NTRS)

Foster, J. C.; St.-Maurice, J.-P.; Abreu, V. J.

1983-01-01

Calculations based on simultaneous observations of the electric field magnitude, and individual measurements of ion drift velocity and particle precipitation, over the lifetime of the AE-C satellite, are used to determine high latitude Joule heating. Conductivities produced by an averaged seasonal illumination were included with those calculated from particle precipitation. It is found that high latitude Joule heating occurs in an approximately oval pattern, and consists of dayside cleft, dawn and dusk sunward convection, and night sector heating regions. On average, heating in the cleft and dawn-dusk regions contributes the largest heat input, and there is no apparent difference between hemispheres for similar seasons. Joule heat input is 50 percent greater in summer than in winter, due primarily to the greater conductivity caused by solar production.

Investigating the Effect of Impurities on Macromolecule Crystal Growth in Microgravity

NASA Technical Reports Server (NTRS)

Snell, Edward H.; Judge, Russell A.; Crawford, Lisa; Forsythe, Elizabeth L.; Pusey, Marc L.; Sportiello, Michael; Todd, Paul; Bellamy, Henry; Lovelace, Jeff; Cassanto, John M.;

Sources and loads of nutrients in the South Platte River, Colorado and Nebraska, 1994-95

USGS Publications Warehouse

Litke, D.W.

1996-01-01

The South Platte River Basin was one of 20 river basins selected in 1991 for investigation as part of the U.S. Geological Survey's National Water- Quality Assessment (NAWQA) Program. Nationwide, nutrients have been identified as one of the primary nationwide water-quality concerns and are of particular interest in the South Platte River Basin where nutrient concentrations are large compared to concentrations in other NAWQA river basins. This report presents estimates of the magnitude of nutrient-source inputs to the South Platte River Basin, describes nutrient concen- trations and loads in the South Platte River during different seasons, and presents comparisons of nutrient inputs to instream nutrient loads. Annual nutrient inputs to the basin were estimated to be 306,000 tons of nitrogen and 41,000 tons of phosphorus. The principal nutrient sources were wastewater-treatment plants, fertilizer and manure applications, and atmospheric deposition. To characterize nutrient concentrations and loads in the South Platte River during different seasons, five nutrient synoptic samplings were conducted during 1994 and 1995. Upstream from Denver, Colorado, during April 1994 and January 1995, total nitrogen concentrations were less than 2 milligrams per liter (mg/L), and total phosphorus concentrations were less than 0.2 mg/L. The water in the river at this point was derived mostly from forested land in the mountains west of Denver. Total nutrient concentrations increased through the Denver metropolitan area, and concentration peaks occurred just downstream from each of Denver's largest wastewater-treatment plants with maximum concentrations of 13.6 mg/L total nitrogen and 2.4 mg/L total phosphorus. Nutrient concen- concentrations generally decreased downstream from Denver. Upstream from Denver during April 1994 and January 1995, total nitrogen loads were less than 1,000 pounds per day (lb/d), and total phosphorus loads were less than 125 lb/d. Total nutrient loads increased through the Denver metropolitan area, and load peaks occurred just downstream from each of Denver's largest wastewater-treatment plants, with a maximum load of 14,000 lb/d total nitrogen and 2,300 lb/d total phosphorus. In April 1994, nutrient loads generally decreased from Henderson, Colorado, to North Platte, Nebraska. In January 1995, however, nutrient loads increased from Henderson to Kersey, Colorado (maximum loads of 31,000 lb/d total nitrogen and 3,000 lb/d total phosphorus), and then decreased from Kersey to North Platte. Seasonal nutrient loads primarily were dependent on streamflow. Total nitrogen loads were largest in June 1994 and January 1995 when streamflows also were largest. During June, streamflow was large, but nitrogen concentrations were small, which indicated that snowmelt runoff diluted the available supply of nitrogen. Total phosphorus loads were largest in June, when streamflow and phosphorus concentrations were large, which indicated an additional source of phosphorus during snowmelt runoff. Streamflow along the South Platte River was smallest in April and August 1994, and nutrient loads also were smallest during these months. The downstream pattern for nutrient loads did not vary much by season. Loads were large at Henderson, decreased between Henderson and Kersey, and usually were largest at Kersey. The magnitude of the decrease in loads between Henderson and Kersey varied between synoptics and was dependent on the amount of water removed by irrigation ditches. Nutrient loads leaving the basin were very small compared to the estimated total nutrient inputs to the basin. Streamflow balances indicated that the South Platte River is a gaining river throughout much of its length; streamflow-balance residuals were as large as 15 cubic feet per second per mile. Nutrient-load balances indicated that increases in river nitrate loads were, in some places, due to nitrification and, elsewhere, were due to the influx of nitrate-enriched ground water to

Comparing the November 2002 Denali and November 2001 Kunlun earthquakes

USGS Publications Warehouse

Bufe, C.G.

2004-01-01

Major strike-slip earthquakes recently occurred in Alaska on the central Denali fault (M 7.9) on 3 November 2002, and in Tibet on the central Kunlun fault (M 7.8) on 14 November 2001. Both earthquakes generated large surface waves with Ms [U.S. Geological Survey (USGS)] of 8.5 (Denali) and 8.0 (Kunlun). Each event occurred on an east-west-trending strike-slip fault situated near the northern boundary of an intense deformation zone that is characterized by lateral extrusion and rotation of crustal blocks. Each earthquake produced east-directed nearly unilateral ruptures that propagated 300 to 400 km. Maximum lateral surface offsets and maximum moment release occurred well beyond 100 km from the rupture initiation, with the events exhibiting by far the largest separations of USGS hypocenter and Harvard Moment Tensor Centroid (CMT) for strike-slip earthquakes in the 27-year CMT catalog. In each sequence, the largest aftershock was more than two orders of magnitude smaller than the mainshock. Regional moment release had been accelerating prior to the main shocks. The close proximity in space and time of the 1964 Prince William Sound and 2002 Denali earthquakes, relative to their rupture lengths and estimated return times, suggests that these events may be part of a recurrent cluster in the vicinity of a complex plate boundary.

Identification and properties of the largest subunit of the DNA-dependent RNA polymerase of fish lymphocystis disease virus: dramatic difference in the domain organization in the family Iridoviridae.

PubMed

Müller, M; Schnitzler, P; Koonin, E V; Darai, G

1995-05-01

Cytoplasmic DNA viruses encode a DNA-dependent RNA polymerase (DdRP) that is essential for transcription of viral genes. The amino acid sequences of the known largest subunits of DdRPs from different species contain highly conserved regions. Oligonucleotide primers, deduced from two conserved domains (RQP[T/S]LH and NADFDGDE) were used for detecting the corresponding gene of fish lymphocystis disease virus (FLCDV), a member of the family Iridoviridae, which replicates in the cytoplasm of infected cells of flatfish. The gene coding for the largest subunit of the DdRP was identified using a PCR-derived probe. The screening of the complete EcoRI gene library of the viral genome led to the identification of the gene locus of the largest subunit of the DdRP within the EcoRI DNA fragment B (12.4 kbp, 0.034 to 0.165 map units). The nucleotide sequence of a part (8334 bp) of the EcoRI DNA fragment B was determined and a large ORF on the lower strand (ATG = 5787; TAA = 2190) was detected which encodes a protein of 1199 amino acids. Comparison of the amino acid sequences of the largest subunits of the DdRP (RPO1) of FLCDV and Chilo iridescent virus (CIV) revealed a dramatic difference in their domain organization. Unlike the 1051 aa RPO1 of CIV, which lacks the C-terminal domain conserved in eukaryotic, eubacterial and other viral RNA polymerases, the 1199 aa RPO1 of FLCDV is fully collinear with its cellular and viral homologues. Despite this difference, comparative analysis of the amino acid sequences of viral and cellular RNA polymerases suggests a common origin for the largest RNA polymerase subunits of FLCDV and CIV.

Association between different phases of menstrual cycle and body image measures of perceived size, ideal size, and body dissatisfaction.

PubMed

Teixeira, André Luiz S; Dias, Marcelo Ricardo C; Damasceno, Vinícius O; Lamounier, Joel A; Gardner, Rick M

2013-12-01

The association between phases of the menstrual cycle and body image was investigated. 44 university women (M age = 23.3 yr., SD = 4.7) judged their perceived and ideal body size, and body dissatisfaction was calculated at each phase of the menstrual cycle, including premenstrual, menstrual, and intermenstrual. Participants selected one of nine figural drawings ranging from very thin to obese that represented their perceived size and ideal size. Body dissatisfaction was measured as the absolute difference between scores on perceived and ideal figural drawings. During each menstrual phase, anthropometric measures of weight, height, body mass index, circumference of waist and abdomen, and body composition were taken. There were no significant differences in any anthropometric measures between the three menstrual cycle phases. Perceived body size and body dissatisfaction were significantly different between menstrual phases, with the largest perceived body size and highest body dissatisfaction occurring during the menstrual phase. Ideal body size did not differ between menstrual phases, although participants desired a significantly smaller ideal size as compared to the perceived size.

INTERNATIONAL REPORT: Revised Values for (t90 - t68) from 630°C to 1064°C

NASA Astrophysics Data System (ADS)

Rusby, R. L.; Hudson, R. P.; Durieux, M.

1994-01-01

A revised table of differences (t90 - t68) between values of temperature on the International Temperature Scale of 1990, ITS-90, and the corresponding values on the International Practical Temperature Scale of 1968, IPTS-68, is published at the request of the Comité Consultatif de Thermométrie (CCT). The revision affects only the range 630°C to 1064°C, where the IPTS-68 specified the use of platinum-10% rhodium versus platinum thermocouples. It follows from new intercomparisons of thermocouples carrying IPTS-68 calibrations with platinum resistance thermometers and radiation thermometers calibrated in accordance with the ITS-90. The largest change occurs at 760°C, where the difference formerly tabulated as 0,36°C is now 0,04°C. The revision concerns only the assessment of the differences between the ITS-90 and the IPTS-68, and does not affect the ITS-90 in any way.

The geomorphic effectiveness of a large flood on the Rio Grande in the Big Bend region: insights on geomorphic controls and post-flood geomorphic response

USGS Publications Warehouse

Dean, David J.; Schmidt, John C.

2013-01-01

Since the 1940s, the Rio Grande in the Big Bend region has undergone long periods of channel narrowing, which have been occasionally interrupted by rare, large floods that widen the channel (termed a channel reset). The most recent channel reset occurred in 2008 following a 17-year period of extremely low stream flow and rapid channel narrowing. Flooding was caused by precipitation associated with the remnants of tropical depression Lowell in the Rio Conchos watershed, the largest tributary to the Rio Grande. Floodwaters approached 1500 m3/s (between a 13 and 15 year recurrence interval) and breached levees, inundated communities, and flooded the alluvial valley of the Rio Grande; the wetted width exceeding 2.5 km in some locations. The 2008 flood had the 7th largest magnitude of record, however, conveyed the largest volume of water than any other flood. Because of the narrow pre-flood channel conditions, record flood stages occurred. We used pre- and post-flood aerial photographs, channel and floodplain surveys, and 1-dimensional hydraulic models to quantify the magnitude of channel change, investigate the controls of flood-induced geomorphic changes, and measure the post-flood response of the widened channel. These analyses show that geomorphic changes included channel widening, meander migration, avulsions, extensive bar formation, and vertical floodplain accretion. Reach-averaged channel widening between 26 and 52% occurred, but in some localities exceeded 500%. The degree and style of channel response was related, but not limited to, three factors: 1) bed-load supply and transport, 2) pre-flood channel plan form, and 3) rapid declines in specific stream power downstream of constrictions and areas of high channel bed slope. The post-flood channel response has consisted of channel contraction through the aggradation of the channel bed and the formation of fine-grained benches inset within the widened channel margins. The most significant post-flood geomorphic changes have occurred at and downstream from ephemeral tributaries that contribute large volumes of sediment.

The Maupin, Oregon Earthquake Swarm

NASA Astrophysics Data System (ADS)

Braunmiller, J.; Williams, M.; Trehu, A. M.; Nabelek, J.

2008-12-01

The area near Maupin, Oregon has experienced over 300 earthquakes since December 2006. The events, located by the Pacific Northwest Seismic Network (PNSN), occurred ~10 km SE of the town in central Oregon and ~50 km E-SE of Mount Hood. The temporal event pattern and lack of a distinct main shock are characteristic of an earthquake swarm with the event-size distribution indicating a low b-value similar to other non-volcanic swarms. Locations show a NW-SE trending, ~4x3 km cluster at apparent depths of 12-24 km. The largest events (Mw=3.8 and 3.9) on March 1, 2007 and July 14, 2008 occurred more than one year apart; 11 other events had a magnitude of 3 or greater. The larger events were felt locally. During the first 14 months EarthScope USArray seismic stations surrounded the swarm, providing a unique high-quality dataset. Waveform similarity at the closest USArray site G06A indicates hypocenters are much tighter than suggested by the PNSN distribution. Moment tensor inversion reveals nearly identical double- couple strike-slip mechanisms on a plane striking ~15° NW for the three largest 2007 events and the July 2008 event. The April 2008 Mw=3.3 event is rotated ~10° clockwise consistent with slight changes of G06A three-component waveforms relative to the other events. Preferred centroid depths are in the 15-20 km range. Historically, seismicity in the Pacific Northwest east of the Cascades is characterized by sporadic bursts of clustered seismicity with occasional M=6 earthquakes. The largest instrumentally recorded earthquake near Maupin (Mw=4.6) occurred 1976. An earlier swarm was observed 1987, but since then only ~2 events/yr occurred until the current swarm. In spite of recurrent seismicity, exposed surface rocks near Maupin are undeformed lava flows of the Columbia River Basalt Group and older John Day volcanics. The geologic map of Oregon shows a NW-trending dip slip fault near the epicenter area, inconsistent with moment tensor solutions. The cause for the swarm is currently unknown with hypotheses ranging from magmatic or fluid motion in the crust to tectonic activity along a weakly coupled microplate boundary.

The influence of head diameter and wall thickness on deformations of metallic acetabular press-fit cups and UHMWPE liners: a finite element analysis.

PubMed

Goebel, Paul; Kluess, Daniel; Wieding, Jan; Souffrant, Robert; Heyer, Horst; Sander, Manuela; Bader, Rainer

2013-03-01

To increase the range of motion of total hip endoprostheses, prosthetic heads need to be enlarged, which implies that the cup and/or liner thickness must decrease. This may have negative effects on the wear rate, because the acetabular cups and liners could deform during press-fit implantation and hip joint loading. We compared the metal cup and polyethylene liner deformations that occurred when different wall thicknesses were used in order to evaluate the resulting changes in the clearance of the articulating region. A parametric finite element model utilized three cup and liner wall thicknesses to analyze cup and liner deformations after press-fit implantation into the pelvic bone. The resultant hip joint force during heel strike was applied while the femur was fixed, accounting for physiological muscle forces. The deformation behavior of the liner under joint loading was therefore assessed as a function of the head diameter and the resulting clearance. Press-fit implantation showed diametral cup deformations of 0.096, 0.034, and 0.014 mm for cup wall thicknesses of 3, 5, and 7 mm, respectively. The largest deformations (average 0.084 ± 0.003 mm) of liners with thicknesses of 4, 6, and 8 mm occurred with the smallest cup wall thickness (3 mm). The smallest liner deformation (0.011 mm) was obtained with largest cup and liner wall thicknesses. Under joint loading, liner deformations in thin-walled acetabular cups (3 mm) reduced the initial clearance by about 50 %. Acetabular press-fit cups with wall thicknesses of ≤5 mm should only be used in combination with polyethylene liners >6 mm thick in order to minimize the reduction in clearance.

Graduation of fertility schedules: an analysis of fertility patterns in London in the 1980s and an application to fertility forecasts.

PubMed

Congdon, P

1990-08-01

London's average total fertility rate (TFR) stood at 1.75. Using a cluster analysis to compare the 1985-1987 fertility patterns of different boroughs of London, demographers learned that 5 natural groupings occurred. 4 boroughs in a central London cluster have the distinction of having a low TFR (1.38) and late fertility (average age of 29.58 years). The researchers attributed these occurrences to the high levels of employment and career attachment and low rates of marriage among women in this cluster. 2 inner city boroughs constituted the smallest cluster and had the largest TFR (2.37), mainly due to high numbers of births to the ethnic minorities. The largest cluster consisted of 12 boroughs located mainly along the periphery with 2 centrally located boroughs (TFR, 1.79). Some of the upper class outer boroughs characterized another cluster with a TFR of 1.61. Another cluster made up of inner and outer boroughs in east and southeast London had a ample proportion of manual worker (TFR, 2.04). Social class most likely accounted for the contrast in TFRs between the 2 aformentioned clusters. Demographers observed that cyclical fluctuation of fertility occurred as opposed to secular trends. Due to these fluctuations, demographers used autoregressive moving average forecast models to time series of the fertility variables in London since 1952. They also applied structural time series models which included regression variables and the influence of cyclical and/or trend behavior. The results showed that large cohorts and the increase in female economic activity caused a delay in the modal age of births and a reduction in the number of births.

Environment Partitioning and Reactivity of Polybrominated Diphenylethers

NASA Technical Reports Server (NTRS)

Hua, Inez; Iraci, Laura T.; Jafvert, Chad; Bezares-Cruz, Juan

2004-01-01

Polybrominated diphenyl ethers (PBDEs) are an important class of flame retardants. Annual global demand for these compounds was over 67,000 metric tons in 2001. PBDEs have recently been extensively investigated as environmental contaminants because they have been detected in air, sediment, and tissue samples from urban and remote areas. Important issues include quantifying PBDE partitioning in various environmental compartments, and elucidating transformation pathways. The partitioning of PBDE congeners to aerosols was estimated for 16 sites in the United States, Canada, and Mexico. The aerosol particles were PM2.5, the total suspended particle (TSP) concentration varied between 3.0 - 55.4 micro g/cubic meter, and the organic fraction ranged from 11 - 41%; these data are published values for each site. It is estimated that the largest fraction of each PBDE associated with the aerosol particles occurs in Mexico City, and the smallest fraction in Colorado Plateau. Although the organic fraction in Mexico City is about 60% of that observed in the Colorado Plateau, the TSP is larger by a factor of about 18.5, and it is the difference in TSP that strongly influences the fraction of particle-bound PBDE in this case. PBDE partitioning to PM2.5 particles also varies seasonally because of temperature variations. For the less brominated congeners the percentage that is particle-bound is relatively low, regardless of air temperature. In contrast, the heavier congeners exhibit a significant temperature dependence: as the temperature decreases (fall, winter) the percentage of PBDE that is particle-bound increases. The partitioning calculations complement experimental data indicating that decabromodiphenyl ether (DBDE) dissolved in hexane transforms very rapidly when irradiated with solar light. DBDE is the most highly brominated PBDE congener (10 bromine atoms) and occurs in the commercial formulation which is subject to the largest global demand.

Environmental Partitioning and Reactivity of Polybrominated Diphenylethers

NASA Astrophysics Data System (ADS)

Hua, I.; Iraci, L.; Jafvert, C.; Bezares-Cruz, J.

2004-05-01

Polybrominated diphenyl ethers (PBDEs) are an important class of flame retardants. Annual global demand for these compounds was over 67,000 metric tons in 2001. PBDEs have recently been extensively investigated as environmental contaminants because they have been detected in air, sediment, and tissue samples from urban and remote areas. Important issues include quantifying PBDE partitioning in various environmental compartments, and elucidating transformation pathways. The partitioning of PBDE congeners to aerosols was estimated for 16 sites in the United States, Canada, and Mexico. The aerosol particles were PM2.5, the total suspended particle (TSP) concentration varied between 3.0 - 55.4 μ g m-3, and the organic fraction ranged from 11 - 41%; these data are published values for each site. It is estimated that the largest fraction of each PBDE associated with the aerosol particles occurs in Mexico City, and the smallest fraction in Colorado Plateau. Although the organic fraction in Mexico City is about 60% of that observed in the Colorado Plateau, the TSP is larger by a factor of about 18.5, and it is the difference in TSP that strongly influences the fraction of particle-bound PBDE in this case. PBDE partitioning to PM2.5 particles also varies seasonally because of temperature variations. For the less brominated congeners, the percentage that is particle-bound is relatively low, regardless of air temperature. In contrast, the heavier congeners exhibit a significant temperature dependence: as the temperature decreases (fall, winter) the percentage of PBDE that is particle-bound increases. The partitioning calculations complement experimental data indicating that decabromodiphenyl ether (DBDE) dissolved in hexane transforms very rapidly when irradiated with solar light. DBDE is the most highly brominated PBDE congener (10 bromine atoms) and occurs in the commercial formulation which is subject to the largest global demand.

Fast and Slow Spindles during the Sleep Slow Oscillation: Disparate Coalescence and Engagement in Memory Processing

PubMed Central

Mölle, Matthias; Bergmann, Til O.; Marshall, Lisa; Born, Jan

2011-01-01

Study Objectives: Thalamo-cortical spindles driven by the up-state of neocortical slow (< 1 Hz) oscillations (SOs) represent a candidate mechanism of memory consolidation during sleep. We examined interactions between SOs and spindles in human slow wave sleep, focusing on the presumed existence of 2 kinds of spindles, i.e., slow frontocortical and fast centro-parietal spindles. Design: Two experiments were performed in healthy humans (24.5 ± 0.9 y) investigating undisturbed sleep (Experiment I) and the effects of prior learning (word paired associates) vs. non-learning (Experiment II) on multichannel EEG recordings during sleep. Measurements and Results: Only fast spindles (12-15 Hz) were synchronized to the depolarizing SO up-state. Slow spindles (9-12 Hz) occurred preferentially at the transition into the SO down-state, i.e., during waning depolarization. Slow spindles also revealed a higher probability to follow rather than precede fast spindles. For sequences of individual SOs, fast spindle activity was largest for “initial” SOs, whereas SO amplitude and slow spindle activity were largest for succeeding SOs. Prior learning enhanced this pattern. Conclusions: The finding that fast and slow spindles occur at different times of the SO cycle points to disparate generating mechanisms for the 2 kinds of spindles. The reported temporal relationships during SO sequences suggest that fast spindles, driven by the SO up-state feed back to enhance the likelihood of succeeding SOs together with slow spindles. By enforcing such SO-spindle cycles, particularly after prior learning, fast spindles possibly play a key role in sleep-dependent memory processing. Citation: Mölle M; Bergmann TO; Marshall L; Born J. Fast and slow spindles during the sleep slow oscillation: disparate coalescence and engagement in memory processing. SLEEP 2011;34(10):1411–1421. PMID:21966073

A Wavelet based Suboptimal Kalman Filter for Assimilation of Stratospheric Chemical Tracer Observations

NASA Technical Reports Server (NTRS)

Tangborn, Andrew; Auger, Ludovic

2003-01-01

A suboptimal Kalman filter system which evolves error covariances in terms of a truncated set of wavelet coefficients has been developed for the assimilation of chemical tracer observations of CH4. This scheme projects the discretized covariance propagation equations and covariance matrix onto an orthogonal set of compactly supported wavelets. Wavelet representation is localized in both location and scale, which allows for efficient representation of the inherently anisotropic structure of the error covariances. The truncation is carried out in such a way that the resolution of the error covariance is reduced only in the zonal direction, where gradients are smaller. Assimilation experiments which last 24 days, and used different degrees of truncation were carried out. These reduced the covariance size by 90, 97 and 99 % and the computational cost of covariance propagation by 80, 93 and 96 % respectively. The difference in both error covariance and the tracer field between the truncated and full systems over this period were found to be not growing in the first case, and growing relatively slowly in the later two cases. The largest errors in the tracer fields were found to occur in regions of largest zonal gradients in the constituent field. This results indicate that propagation of error covariances for a global two-dimensional data assimilation system are currently feasible. Recommendations for further reduction in computational cost are made with the goal of extending this technique to three-dimensional global assimilation systems.

Evaluating How Post-Bronchodilator Vital Capacities Affect the Diagnosis of Obstruction in Pulmonary Function Tests.

PubMed

Blagev, Denitza P; Sorenson, Dean; Linares-Perdomo, Olinto; Bamberg, Stacy; Hegewald, Matthew; Morris, Alan H

2016-11-01

Although the ratio of FEV 1 to the vital capacity (VC) is universally accepted as the cornerstone of pulmonary function test (PFT) interpretation, FVC remains in common use. We sought to determine what the differences in PFT interpretation were when the largest measured vital capacity (VC max ) was used instead of the FVC. We included 12,238 consecutive PFTs obtained for routine clinical care. We interpreted all PFTs first using FVC in the interpretation algorithm and then again using the VC max , obtained either before or after administration of inhaled bronchodilator. Six percent of PFTs had an interpretive change when VC max was used instead of FVC. The most common changes were: new diagnosis of obstruction and exclusion of restriction (previously suggested by low FVC without total lung capacity measured by body plethysmography). A nonspecific pattern occurred in 3% of all PFT interpretations with FVC. One fifth of these 3% produced a new diagnosis of obstruction with VC max . The largest factors predicting a change in PFT interpretation with VC max were a positive bronchodilator response and the administration of a bronchodilator. Larger FVCs decreased the odds of PFT interpretation change. Surprisingly, the increased numbers of PFT tests did not increase odds of PFT interpretation change. Six percent of PFTs have a different interpretation when VC max is used instead of FVC. Evaluating borderline or ambiguous PFTs using the VC max may be informative in diagnosing obstruction and excluding restriction. Copyright © 2016 by Daedalus Enterprises.

Cultural change in the songs of humpback whales (Megaptera novaeangliae) from Tonga

USGS Publications Warehouse

Eriksen, N.; Miller, L.A.; Tougaard, J.; Helweg, D.A.

2005-01-01

Some humpback whales migrate annually from Antarctic feeding grounds to the seas around the Tongan Islands to give birth and mate. The Tongan humpbacks are considered part of Southern Hemisphere Group V that splits during migration, some swimming to Eastern Australia and others to various Polynesian Islands. During this time long complex songs are produced. The song is thought to be a male breeding display and may serve either as an intra-sexual or an inter-sexual signal or both. It is in a constant state of change that occurs every season. Since these changes are directional they cannot be described by drift, and singers incorporate changes as they occur, thus song must be shared through cultural transmission. This investigation describes the cultural changes that occurred in 158 songs recorded from Tongan humpbacks through the 1990s. The rate of change differed within years, some themes were retained for as much as five years and others were lost after only two years. The farther apart the years the less similar are the songs, as in the humpback songs of the Northern Hemisphere. The largest number of changes seems to have occurred in the early 1990s where all themes seemed to have been lost and new ones originated. What initiates these changes remains speculative, but we assess some hypotheses in relation to humpback whale behaviour and cultural transmission in avian song. ?? Koninklijke Brill NV, 2005.

Attendance and Substance Use Outcomes for the Seeking Safety Program: Sometimes Less Is More

ERIC Educational Resources Information Center

Hien, Denise A.; Morgan-Lopez, Antonio A.; Campbell, Aimee N. C.; Saavedra, Lissette M.; Wu, Elwin; Cohen, Lisa; Ruglass, Lesia; Nunes, Edward V.

2012-01-01

Objective: This study uses data from the largest effectiveness trial to date on treatment of co-occurring posttraumatic stress and substance use disorders, using advances in statistical methodology for modeling treatment attendance and membership turnover in rolling groups. Method: Women receiving outpatient substance abuse treatment (N = 353)…

A molecular genetic linkage map identifying the St and H sub-genomes of Elymus wheatgrass (Poaceae: Triticeae)

USDA-ARS?s Scientific Manuscript database

Elymus L. is the largest and most complex genus in the Triticeae with approximately 150 polyploid perennial grass species occurring worldwide. We report here the first genetic linkage map for Elymus. Backcross mapping populations were created by crossing caespitose Elymus wawawaiensis (EW) (Snake ...

Phytophthora megakarya, a causal agent of black pod rot in Africa

USDA-ARS?s Scientific Manuscript database

In most parts of the world where Theobroma cacao is grown, Phytophthora palmivora is the major concern for causing black pod rot (BPR). Phytophthora megakarya, on the other hand, occurs only in Africa, but represents a major threat to cacao production, the countries of West Africa being the largest ...

Addition of glucose oxidase for the improvement of refrigerated dough quality

USDA-ARS?s Scientific Manuscript database

Refrigerated dough encompasses a wide range of products and is a very popular choice for consumers. Two of the largest problems that occur during refrigerated dough storage are dough syruping and loss of dough strength. The goal of this study was to evaluate glucose oxidase as an additive to refri...

Temporal changes to fire risk in dissimilar WUI communities

Treesearch

N. C. Leyshon; C. A. Dicus; D. B. Sapsis

2015-01-01

Despite increasing proportions of governmental budgets allocated to fire suppression resources, wildfires annually destroy great numbers of homes and critical infrastructure in the wildland-urban interface (WUI). Since 2002, the largest fires in the histories of California, Arizona, Colorado, New Mexico, Utah, Oregon, and Texas have occurred in spite of increased fire...

The Sundarbans: a unique wilderness of the world

Treesearch

Laskar Muqsudur Rahman

2000-01-01

The Sundarbans, natural mangrove forests of Bangladesh covers an area of 577,000 ha. It is the largest single tract of mangrove forest in the world. The members of the family Rhizophoracae do not dominate the tree vegetation of the Sundarbans. Heritiera fomes and Excoecaria agallocha are the two most extensively occurring tree...

Poisoning the Mind: Arsenic Contamination of Drinking Water Wells and Children's Educational Achievement in Rural Bangladesh

ERIC Educational Resources Information Center

Asadullah, M. Niaz; Chaudhury, Nazmul

2011-01-01

Bangladesh has experienced the largest mass poisoning of a population in history owing to contamination of groundwater with naturally occurring inorganic arsenic. Prolonged drinking of such water risks development of diseases and therefore has implications for children's cognitive and psychological development. This study examines the effect of…

Large Second-Harmonic Response of C60 Thin Films

DTIC Science & Technology

1992-04-01

temperature; the largest value occurred at a nominal temperature of 140’C where X"’ is ten times larger than the room temperature value. 14. SU8 )ECT TERMS 1S...optical chromatography.’ The purity was examined by Raman. IR materials based upon conjugated-carbon- polymers charac- absorption, high-performance liquid

Dynamics of a threatened orchid in flooded wetlands

Treesearch

Carolyn Hull Sieg; Paige M. Wolken

1999-01-01

One of the three largest metapopulations of the western prairie fringed orchid (Platanthera praeclara) occurs on the Sheyenne National Grassland, in southeastern North Dakota. Our study was initiated in 1993 to quantify the effect of flooding on individual orchid plants. In 1993, 66 plants (33 flowering and 33 vegetative) growing in standing water...

US Research on Wildland Fires??…with a Focus on EPA’s Efforts

EPA Science Inventory

The United States spends more than $1 billion every year to fight wildfires. According to National Interagency Fire Center data, of the 10 years with the largest acreage burned, nine have occurred since 2000 (as of 2012). This period coincides with many of the warmest years on re...

Promoting Sustainable Economic Growth in Mexico (Fact Sheet)

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

Watson, A.; Butheau, M.; Sandor, D.

2013-11-01

Mexico is the second largest economy in Latin America, with rapid growth occurring in the industrial and services sectors. A forward-thinking country on climate change, the nation recognizes that the threat of higher temperatures, changes in precipitation patterns, and more frequent weather-related disasters could pose a substantial risk to its expanding economy.

Contributions to the anatomy of birds

USGS Publications Warehouse

Shufeldt, R. W.

1882-01-01

At the present writing we know of but one species of the so-called Burrowing Owls inhabiting America, and this is represented by three existing races, the typical and largest of those being the Athene cunicularia, a species confined to South America, while its two varieties occur with the limits of the United States.

Effects of nutrient management on nitrate levels in ground water near Ephrata Pennsylvania

USGS Publications Warehouse

Hall, David W.

1992-01-01

Effects of the implementation of nutrient management practices on ground-water quality were studied at a 55-acre farm in Lancaster County, Pennsylvania, from 1985-90. After nutrient management practices were implemented at the site in October 1986, statistically significant decreases (Wilcoxon Mann-Whitney test) in median nitrate concentrations in ground-water samples occurred at four of the five wells monitored. The largest decreases in nitrate concentration occurred in samples collected at the wells that had the largest nitrate concentrations prior to nutrient management. The decreases in median nitrate concentrations in ground-water samples ranged from 8 to 32 percent of the median concentrations prior to nutrient management and corresponded to nitrogen application decreases of 39 to 67 percent in contributing areas that were defined upgradient of these wells. Changes in nitrogen applications to the contributing areas of five water wells were correlated (Spearman rank-sum test) with nitrate concentrations of the well water. Changes in ground-water nitrate concentrations lagged behind the changes in applied-nitrogen fertilizers (primarily manure) by approximately 4 to 19 months.

Assessing the effect of elevated carbon dioxide on soil carbon: a comparison of four meta-analyses.

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

Hungate, B. A.; van Groenigen, K.; Six, J.

2009-08-01

Soil is the largest reservoir of organic carbon (C) in the terrestrial biosphere and soil C has a relatively long mean residence time. Rising atmospheric carbon dioxide (CO{sub 2}) concentrations generally increase plant growth and C input to soil, suggesting that soil might help mitigate atmospheric CO{sub 2} rise and global warming. But to what extent mitigation will occur is unclear. The large size of the soil C pool not only makes it a potential buffer against rising atmospheric CO{sub 2}, but also makes it difficult to measure changes amid the existing background. Meta-analysis is one tool that can overcomemore » the limited power of single studies. Four recent meta-analyses addressed this issue but reached somewhat different conclusions about the effect of elevated CO{sub 2} on soil C accumulation, especially regarding the role of nitrogen (N) inputs. Here, we assess the extent of differences between these conclusions and propose a new analysis of the data. The four meta-analyses included different studies, derived different effect size estimates from common studies, used different weighting functions and metrics of effect size, and used different approaches to address nonindependence of effect sizes. Although all factors influenced the mean effect size estimates and subsequent inferences, the approach to independence had the largest influence. We recommend that meta-analysts critically assess and report choices about effect size metrics and weighting functions, and criteria for study selection and independence. Such decisions need to be justified carefully because they affect the basis for inference. Our new analysis, with a combined data set, confirms that the effect of elevated CO{sub 2} on net soil C accumulation increases with the addition of N fertilizers. Although the effect at low N inputs was not significant, statistical power to detect biogeochemically important effect sizes at low N is limited, even with meta-analysis, suggesting the continued need for long-term experiments.« less

Induced earthquake magnitudes are as large as (statistically) expected

USGS Publications Warehouse

Van Der Elst, Nicholas; Page, Morgan T.; Weiser, Deborah A.; Goebel, Thomas; Hosseini, S. Mehran

2016-01-01

A major question for the hazard posed by injection-induced seismicity is how large induced earthquakes can be. Are their maximum magnitudes determined by injection parameters or by tectonics? Deterministic limits on induced earthquake magnitudes have been proposed based on the size of the reservoir or the volume of fluid injected. However, if induced earthquakes occur on tectonic faults oriented favorably with respect to the tectonic stress field, then they may be limited only by the regional tectonics and connectivity of the fault network. In this study, we show that the largest magnitudes observed at fluid injection sites are consistent with the sampling statistics of the Gutenberg-Richter distribution for tectonic earthquakes, assuming no upper magnitude bound. The data pass three specific tests: (1) the largest observed earthquake at each site scales with the log of the total number of induced earthquakes, (2) the order of occurrence of the largest event is random within the induced sequence, and (3) the injected volume controls the total number of earthquakes rather than the total seismic moment. All three tests point to an injection control on earthquake nucleation but a tectonic control on earthquake magnitude. Given that the largest observed earthquakes are exactly as large as expected from the sampling statistics, we should not conclude that these are the largest earthquakes possible. Instead, the results imply that induced earthquake magnitudes should be treated with the same maximum magnitude bound that is currently used to treat seismic hazard from tectonic earthquakes.

On the Sizes of the North Atlantic Basin Tropical Cyclones Based on 34- and 64-kt Wind Radii Data, 2004-2013

NASA Technical Reports Server (NTRS)

Wilson, Robert M.

2014-01-01

At end of the 2012 hurricane season the National Hurricane Center retired the original HURDAT dataset and replaced it with the newer version HURDAT2, which reformatted the original data and included additional information, in particular, estimates of the 34-, 50, and 64-kt wind radii for the interval 2004-2013. During the brief 10-year interval, some 164 tropical cyclones are noted to have formed in the North Atlantic basin, with 77 becoming hurricanes. Hurricane Sandy (2012) stands out as being the largest individual storm that occurred in the North Atlantic basin during the 2004 -2013 timeframe, both in terms of its 34- and 64-kt wind radii and wind areas, having maximum 34- and 64-kt wind radii, maximum wind areas, and average wind areas each more than 2 standard deviations larger than the corresponding means. In terms of the largest yearly total 34-kt wind area (i.e., the sum of all individual storm 34-kt wind areas during the year), the year 2010 stands out as being the largest (about 423 × 10(exp 6) nmi(exp 2)), compared to the mean of about 174 × 10(exp 6) nmi(exp 2)), surpassing the year 2005 (353 x 10(exp 6) nmi(exp 2)) that had the largest number of individual storms (28). However, in terms of the largest yearly total 64-kt wind area, the year 2005 was the largest (about 9 × 10(exp 6) nmi(exp 2)), compared to the mean of about 3 × 106 nmi(exp 2)). Interesting is that the ratio of total 64-kt wind area to total 34-kt wind area has decreased over time, from 0.034 in 2004 to 0.008 in 2013.

Organic solvent desorption from two tegafur polymorphs.

PubMed

Bobrovs, Raitis; Actiņš, Andris

2013-11-30

Desorption behavior of 8 different solvents from α and β tegafur (5-fluoro-1-(tetrahydro-2-furyl)uracil) has been studied in this work. Solvent desorption from samples stored at 95% and 50% relative solvent vapor pressure was studied in isothermal conditions at 30 °C. The results of this study demonstrated that: solvent desorption rate did not differ significantly for both phases; solvent desorption in all cases occurred faster from samples with the largest particle size; and solvent desorption in most cases occurred in two steps. Structure differences and their surface properties were not of great importance on the solvent desorption rates because the main factor affecting desorption rate was sample particle size and sample morphology. Inspection of the structure packing showed that solvent desorption rate and amount of solvent adsorbed were mainly affected by surface molecule arrangement and ability to form short contacts between solvent molecule electron donor groups and freely accessible tegafur tetrahydrofuran group hydrogens, as well as between solvents molecule proton donor groups and fluorouracil ring carbonyl and fluoro groups. Solvent desorption rates of acetone, acetonitrile, ethyl acetate and tetrahydrofuran multilayers from α and β tegafur were approximately 30 times higher than those of solvent monolayers. Scanning electron micrographs showed that sample storage in solvent vapor atmosphere promotes small tegafur particles recrystallization to larger particles. Copyright © 2013 Elsevier B.V. All rights reserved.

Contrasting patterns of Andean diversification among three diverse clades of Neotropical clearwing butterflies.

PubMed

Chazot, Nicolas; De-Silva, Donna Lisa; Willmott, Keith R; Freitas, André V L; Lamas, Gerardo; Mallet, James; Giraldo, Carlos E; Uribe, Sandra; Elias, Marianne

2018-04-01

The Neotropical region is the most biodiverse on Earth, in a large part due to the highly diverse tropical Andean biota. The Andes are a potentially important driver of diversification within the mountains and for neighboring regions. We compared the role of the Andes in diversification among three subtribes of Ithomiini butterflies endemic to the Neotropics, Dircennina, Oleriina, and Godyridina. The diversification patterns of Godyridina have been studied previously. Here, we generate the first time-calibrated phylogeny for the largest ithomiine subtribe, Dircennina, and we reanalyze a published phylogeny of Oleriina to test different biogeographic scenarios involving the Andes within an identical framework. We found common diversification patterns across the three subtribes, as well as major differences. In Dircennina and Oleriina, our results reveal a congruent pattern of diversification related to the Andes with an Andean origin, which contrasts with the Amazonian origin and multiple Andean colonizations of Godyridina. In each of the three subtribes, a clade diversified in the Northern Andes at a faster rate. Diversification within Amazonia occurred in Oleriina and Godyridina, while virtually no speciation occurred in Dircennina in this region. Dircennina was therefore characterized by higher diversification rates within the Andes compared to non-Andean regions, while in Oleriina and Godyridina, we found no difference between these regions. Our results and discussion highlight the importance of comparative approaches in biogeographic studies.

A study of the geomagnetic indices asymmetry based on the interplanetary magnetic field polarities

NASA Astrophysics Data System (ADS)

El-Borie, M. A.; El-Taher, A. M.; Aly, N. E.; Bishara, A. A.

2018-05-01

Data of geomagnetic indices ( aa, Kp, Ap, and Dst) recorded near 1 AU over the period 1967-2016, have been studied based on the asymmetry between the interplanetary magnetic field (IMF) directions above and below of the heliospheric current sheet (HCS). Our results led to the following conclusions: (i) Throughout the considered period, 31 random years (62%) showed apparent asymmetries between Toward (T) and Away (A) polarity days and 19 years (38%) exhibited nearly a symmetrical behavior. The days of A polarity predominated over the T polarity days by 4.3% during the positive magnetic polarity epoch (1991-1999). While the days of T polarity exceeded the days of A polarity by 5.8% during the negative magnetic polarity epoch (2001-2012). (ii) Considerable yearly North-South (N-S) asymmetries of geomagnetic indices observed throughout the considered period. (iii) The largest toward dominant peaks for aa and Ap indices occurred in 1995 near to minimum of solar activity. Moreover, the most substantial away dominant peaks for aa and Ap indices occurred in 2003 (during the descending phase of the solar cycle 23) and in 1991 (near the maximum of solar activity cycle) respectively. (iv) The N-S asymmetry of Kp index indicated a most significant away dominant peak occurred in 2003. (v) Four of the away dominant peaks of Dst index occurred at the maxima of solar activity in the years 1980, 1990, 2000, and 2013. The largest toward dominant peak occurred in 1991 (at the reversal of IMF polarity). (vi) The geomagnetic indices ( aa, Ap, and Kp) all have northern dominance during positive magnetic polarity epoch (1971-1979), while the asymmetries shifts to the southern solar hemisphere during negative magnetic polarity epoch (2001-2012).

Wrinkle ridges in the floor material of Kasei Valles, Mars: Nature and origin

NASA Technical Reports Server (NTRS)

Watters, Thomas R.; Craddock, Robert A.

1991-01-01

Wrinkle ridges on Mars occur almost exclusively in smooth plains material referred to as ridged plains. One of the largest contiguous units of ridged plains occurs on Lunae Planum on the eastern flank of the Tharsis rise. The eastern, western, and northern margins of the ridged plains of Lunae Planum suffered extensive erosion in early Amazonian channel-forming events. The most dramatic example of erosion in early Amazonian plains is in Kasei Valles. The nature an origin of the wrinkle ridges in the floor material of Kasei Valles are discussed.

A Demographic Analysis of American Geophysical Union Membership with Implications for Change

NASA Astrophysics Data System (ADS)

Rhodes, D. D.

2006-12-01

Demographers use population pyramids to characterize the age/gender structure of societal groups. Diagrams of the population of age cohorts for both sexes assume the shape of a pyramid in rapidly expanding groups, having many more young people than older adults. Stable populations have similar numbers of people in age cohorts from infants through middle-age adults. Shrinking populations have fewer children and relatively larger numbers of adults. Demographic analysis of the American Geophysical Union's (AGU) membership reveals significant differences among the numerous specialties and the membership as a whole. The population structure diagram of the total AGU membership is highly asymmetrical with 77.5% male and 22.5% female. Males outnumber females in every age cohort. This is most noticeable among members born prior to 1945. Males belonging to these cohorts make up 16.5% of the total membership, while female members of equivalent age include 0.8% of the total. The largest membership cohort (29% of the total) is comprised of males born between 1950 and 1964, a group that includes both the "baby boom" generation and post-war petroleum exploration expansion. In contrast, the female cohort with birth years from 1970 to 1979 is the largest grouping of women members (8.4% of AGU's membership). Furthermore, women comprise 36% of the members born since 1965, and only 14.5% of those born before 1965. Considered separately, the female membership's age structure is characteristic of a growing population, while the male side is in relative decline. The population structure of the entire membership is mirrored in some specialties, but there are remarkable differences in others. The largest specialty group (hydrology) includes 16.9% of the total AGU membership and has a population structure that differs little from that of the whole organization. Four specialties, Atmospheric Chemistry, Biogeosciences, and Paleoceanography and Paleoclimatology, and Marine Geochemistry differ significantly from the aggregate membership. The population structures of these groups are pyramidal, indicating a strong potential for growth. Women also comprise more than 30% of each of these groups and outnumber men in some recent cohorts. Growth potential is unevenly distributed throughout AGU's membership with traditional specialties likely to experience significant decline as the older cohorts retire and die. Strongest growth is most likely to occur in recently recognized interdisciplinary specialties, especially those in which women already constitute a significant fraction of the membership.

Assessing a local ensemble Kalman filter: perfect model experiments with the National Centers for Environmental Prediction global model

NASA Astrophysics Data System (ADS)

Szunyogh, Istvan; Kostelich, Eric J.; Gyarmati, G.; Patil, D. J.; Hunt, Brian R.; Kalnay, Eugenia; Ott, Edward; Yorke, James A.

2005-08-01

The accuracy and computational efficiency of the recently proposed local ensemble Kalman filter (LEKF) data assimilation scheme is investigated on a state-of-the-art operational numerical weather prediction model using simulated observations. The model selected for this purpose is the T62 horizontal- and 28-level vertical-resolution version of the Global Forecast System (GFS) of the National Center for Environmental Prediction. The performance of the data assimilation system is assessed for different configurations of the LEKF scheme. It is shown that a modest size (40-member) ensemble is sufficient to track the evolution of the atmospheric state with high accuracy. For this ensemble size, the computational time per analysis is less than 9 min on a cluster of PCs. The analyses are extremely accurate in the mid-latitude storm track regions. The largest analysis errors, which are typically much smaller than the observational errors, occur where parametrized physical processes play important roles. Because these are also the regions where model errors are expected to be the largest, limitations of a real-data implementation of the ensemble-based Kalman filter may be easily mistaken for model errors. In light of these results, the importance of testing the ensemble-based Kalman filter data assimilation systems on simulated observations is stressed.

A Large-Scale Super-Structure at z=0.65 in the UKIDSS Ultra-Deep Survey Field

NASA Astrophysics Data System (ADS)

Galametz, Audrey; Candels Clustering Working Group

2017-07-01

In hierarchical structure formation scenarios, galaxies accrete along high density filaments. Superclusters represent the largest density enhancements in the cosmic web with scales of 100 to 200 Mpc. As they represent the largest components of LSS, they are very powerful tools to constrain cosmological models. Since they also offer a wide range of density, from infalling group to high density cluster core, they are also the perfect laboratory to study the influence of environment on galaxy evolution. I will present a newly discovered large scale structure at z=0.65 in the UKIDSS UDS field. Although statistically predicted, the presence of such structure in UKIDSS, one of the most extensively covered and studied extragalactic field, remains a serendipity. Our follow-up confirmed more than 15 group members including at least three galaxy clusters with M200 10^14Msol . Deep spectroscopy of the quiescent core galaxies reveals that the most massive structure knots are at very different formation stage with a range of red sequence properties. Statistics allow us to map formation age across the structure denser knots and identify where quenching is most probably occurring across the LSS. Spectral diagnostics analysis also reveals an interesting population of transition galaxies we suspect are transforming from star-forming to quiescent galaxies.

Is improved contrast sensitivity a natural consequence of visual training?

PubMed Central

Levi, Aaron; Shaked, Danielle; Tadin, Duje; Huxlin, Krystel R.

2015-01-01

Many studies have shown that training and testing conditions modulate specificity of visual learning to trained stimuli and tasks. In visually impaired populations, generalizability of visual learning to untrained stimuli/tasks is almost always reported, with contrast sensitivity (CS) featuring prominently among these collaterally-improved functions. To understand factors underlying this difference, we measured CS for direction and orientation discrimination in the visual periphery of three groups of visually-intact subjects. Group 1 trained on an orientation discrimination task with static Gabors whose luminance contrast was decreased as performance improved. Group 2 trained on a global direction discrimination task using high-contrast random dot stimuli previously used to recover motion perception in cortically blind patients. Group 3 underwent no training. Both forms of training improved CS with some degree of specificity for basic attributes of the trained stimulus/task. Group 1's largest enhancement was in CS around the trained spatial/temporal frequencies; similarly, Group 2's largest improvements occurred in CS for discriminating moving and flickering stimuli. Group 3 saw no significant CS changes. These results indicate that CS improvements may be a natural consequence of multiple forms of visual training in visually intact humans, albeit with some specificity to the trained visual domain(s). PMID:26305736

Attractor Structures of Signaling Networks: Consequences of Different Conformational Barcode Dynamics and Their Relations to Network-Based Drug Design.

PubMed

Szalay, Kristóf Z; Nussinov, Ruth; Csermely, Peter

2014-06-01

Conformational barcodes tag functional sites of proteins and are decoded by interacting molecules transmitting the incoming signal. Conformational barcodes are modified by all co-occurring allosteric events induced by post-translational modifications, pathogen, drug binding, etc. We argue that fuzziness (plasticity) of conformational barcodes may be increased by disordered protein structures, by integrative plasticity of multi-phosphorylation events, by increased intracellular water content (decreased molecular crowding) and by increased action of molecular chaperones. This leads to increased plasticity of signaling and cellular networks. Increased plasticity is both substantiated by and inducing an increased noise level. Using the versatile network dynamics tool, Turbine (www.turbine.linkgroup.hu), here we show that the 10 % noise level expected in cellular systems shifts a cancer-related signaling network of human cells from its proliferative attractors to its largest, apoptotic attractor representing their health-preserving response in the carcinogen containing and tumor suppressor deficient environment modeled in our study. Thus, fuzzy conformational barcodes may not only make the cellular system more plastic, and therefore more adaptable, but may also stabilize the complex system allowing better access to its largest attractor. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Early studies reported extreme findings with large variability: a meta-epidemiologic study in the field of endocrinology.

PubMed

Wang, Zhen; Alahdab, Fares; Almasri, Jehad; Haydour, Qusay; Mohammed, Khaled; Abu Dabrh, Abd Moain; Prokop, Larry J; Alfarkh, Wedad; Lakis, Sumaya; Montori, Victor M; Murad, Mohammad Hassan

2016-04-01

To evaluate the presence of extreme findings and fluctuation in effect size in endocrinology. We systematically identified all meta-analyses published in 2014 in the field of endocrinology. Within each meta-analysis, the effect size of the primary binary outcome was compared across studies according to their order of publication. We pooled studies using the DerSimonian and Laird random-effects method. Heterogeneity was evaluated using the I(2) and tau(2). Twelve percent of the included 100 meta-analyses reported the largest effect size in the very first published study. The largest effect size occurred in the first 2 earliest studies in 31% of meta-analyses. When the effect size was the largest in the first published study, it was three times larger than the final pooled effect (ratio of rates, 3.26; 95% confidence interval: 1.80, 5.90). The largest heterogeneity measured by I(2) was observed in 18% of the included meta-analyses when combining the first 2 studies or 17% when combing the first 3 studies. In endocrinology, early studies reported extreme findings with large variability. This behavior of the evidence needs to be taken into account when used to formulate clinical policies. Copyright © 2016 Elsevier Inc. All rights reserved.

Chironomidae larvae (Diptera) of Neotropical floodplain: overlap niche in different habitats.

PubMed

Butakka, C M M; Ragonha, F H; Takeda, A M

2014-05-01

The niche overlap between trophic groups of Chironomidae larvae in different habitats was observed between trophic groups and between different environments in Neotropical floodplain. For the evaluation we used the index of niche overlap (CXY) and analysis of trophic networks, both from the types and amount of food items identified in the larval alimentary canal. In all environments, the larvae fed on mainly organic matter such as plants fragments and algae, but there were many omnivore larvae. Species that have high values of food items occurred in diverse environments as generalists with great overlap niche and those with a low amount of food items with less overlap niche were classified as specialists. The largest number of trophic niche overlap was observed among collector-gatherers in connected floodplain lakes. The lower values of index niche overlap were predators. The similarity in the diet of different taxa in the same niche does not necessarily imply competition between them, but coexistence when the food resource is not scarce in the environment even in partially overlapping niches.

Hereditary spastic paraplegia in Greece: characterisation of a previously unexplored population using next-generation sequencing.

PubMed

Lynch, David S; Koutsis, Georgios; Tucci, Arianna; Panas, Marios; Baklou, Markella; Breza, Marianthi; Karadima, Georgia; Houlden, Henry

2016-06-01

Hereditary Spastic Paraplegia (HSP) is a syndrome characterised by lower limb spasticity, occurring alone or in association with other neurological manifestations, such as cognitive impairment, seizures, ataxia or neuropathy. HSP occurs worldwide, with different populations having different frequencies of causative genes. The Greek population has not yet been characterised. The purpose of this study was to describe the clinical presentation and molecular epidemiology of the largest cohort of HSP in Greece, comprising 54 patients from 40 families. We used a targeted next-generation sequencing (NGS) approach to genetically assess a proband from each family. We made a genetic diagnosis in >50% of cases and identified 11 novel variants. Variants in SPAST and KIF5A were the most common causes of autosomal dominant HSP, whereas SPG11 and CYP7B1 were the most common cause of autosomal recessive HSP. We identified a novel variant in SPG11, which led to disease with later onset and may be unique to the Greek population and report the first nonsense mutation in KIF5A. Interestingly, the frequency of HSP mutations in the Greek population, which is relatively isolated, was very similar to other European populations. We confirm that NGS approaches are an efficient diagnostic tool and should be employed early in the assessment of HSP patients.

Monitoring reactive microencapsulation dynamics using microfluidics

PubMed Central

Brosseau, Quentin; Baret, Jean-Christophe

2015-01-01

We use microfluidic polydimethylsiloxane (PDMS) devices to measure the kinetics of reactive encapsulations occurring at the interface of emulsion droplets. The formation of the polymeric shell is inferred from the droplet deformability measured in a series of expansion–constriction chambers along the microfluidic chip. With this tool we quantify the kinetic processes governing the encapsulation at the very early stage of shell formation with a time resolution of the order of the millisecond for overall reactions occurring in less than 0.5 s. We perform a comparison of monomer reactivities used for the encapsulation. We study the formation of polyurea microcapsules (PUMCs); the shell formation proceeds at the water–oil interface by an immediate reaction of amines dissolved in the aqueous phase and isocyanates dissolved in the oil phase. We observe that both monomers contribute differently to the encapsulation kinetics. The kinetics of the shell formation process at the oil-in-water (O/W) experiments significantly differs from the water-in-oil (W/O) systems; the component dissolved in the continuous phase has the largest impact on the kinetics. In addition, we quantified the retarding effect on the encapsulation kinetics by the interface stabilizing agent (surfactant). Our approach is valuable for quantifying in situ reactive encapsulation processes and provides guidelines to generate microcapsules with soft interfaces of tailored and controllable interfacial properties. PMID:25705975

Foods of juvenile ring-necked ducks: Relationship to wetland pH

USGS Publications Warehouse

McAuley, D.G.; Longcore, J.R.

1988-01-01

Foods of 37 juvenile ring-necked ducks (Aythya collaris) from 16 different wetlands were examined in eastcentral Maine in 1983-85. Invertebrates made up 70% aggregate dry weight (100% occurrence) of the foods of Class Ia-lla ( 24 days old) ducklings and 32% (86% occurrence) of Class lIb-III ( 25 days old) ducklings. These percentages may be as high as 85% for Ia-lla ducklings and 47% for lIb-III ducklings after adjusting for insect sclerites. Ducklings ate invertebrates from 44 taxa and seeds or fibers from 23 plant taxa. Freshwater sponges (Porifera) were the most important invertebrate and constituted 23% of the foods of all ducklings. Seeds of pondweeds (Potamogeton spp.) were the most important plant foods. Diets of ducklings from high-pH (>6.1) wetlands were more diverse (t = 2.54, P = 0.021) than those from low-pH (<6.1) wetlands and consisted of 33 invertebrate taxa. Only 17 taxa occurred in ducklings from low-pH ponds. Class Ia-lla ducklings from high-pH wetlands ate more invertebrates (77%) than ducklings from lower-pH wetlands (61%), although the difference was not significant (P = 0.21). Sponges made up the largest percentage of the diets and occurred in similar amounts in high- (34%) and low- (31.5%) pH wetlands.

The influence of simulated exploitation on Patella vulgata populations: protandric sex change is size-dependent.

PubMed

Borges, Carla D G; Hawkins, Stephen J; Crowe, Tasman P; Doncaster, C Patrick

2016-01-01

Grazing mollusks are used as a food resource worldwide, and limpets are harvested commercially for both local consumption and export in several countries. This study describes a field experiment to assess the effects of simulated human exploitation of limpets Patella vulgata on their population ecology in terms of protandry (age-related sex change from male to female), growth, recruitment, migration, and density regulation. Limpet populations at two locations in southwest England were artificially exploited by systematic removal of the largest individuals for 18 months in plots assigned to three treatments at each site: no (control), low, and high exploitation. The shell size at sex change (L 50: the size at which there is a 50:50 sex ratio) decreased in response to the exploitation treatments, as did the mean shell size of sexual stages. Size-dependent sex change was indicated by L 50 occurring at smaller sizes in treatments than controls, suggesting an earlier switch to females. Mean shell size of P. vulgata neuters changed little under different levels of exploitation, while males and females both decreased markedly in size with exploitation. No differences were detected in the relative abundances of sexual stages, indicating some compensation for the removal of the bigger individuals via recruitment and sex change as no migratory patterns were detected between treatments. At the end of the experiment, 0-15 mm recruits were more abundant at one of the locations but no differences were detected between treatments. We conclude that sex change in P. vulgata can be induced at smaller sizes by reductions in density of the largest individuals reducing interage class competition. Knowledge of sex-change adaptation in exploited limpet populations should underpin strategies to counteract population decline and improve rocky shore conservation and resource management.

The use of SESK as a trend parameter for localized bearing fault diagnosis in induction machines.

PubMed

Saidi, Lotfi; Ben Ali, Jaouher; Benbouzid, Mohamed; Bechhoefer, Eric

2016-07-01

A critical work of bearing fault diagnosis is locating the optimum frequency band that contains faulty bearing signal, which is usually buried in the noise background. Now, envelope analysis is commonly used to obtain the bearing defect harmonics from the envelope signal spectrum analysis and has shown fine results in identifying incipient failures occurring in the different parts of a bearing. However, the main step in implementing envelope analysis is to determine a frequency band that contains faulty bearing signal component with the highest signal noise level. Conventionally, the choice of the band is made by manual spectrum comparison via identifying the resonance frequency where the largest change occurred. In this paper, we present a squared envelope based spectral kurtosis method to determine optimum envelope analysis parameters including the filtering band and center frequency through a short time Fourier transform. We have verified the potential of the spectral kurtosis diagnostic strategy in performance improvements for single-defect diagnosis using real laboratory-collected vibration data sets. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Distribution and diagenesis of microfossils from the lower Proterozoic Duck Creek Dolomite, Western Australia

NASA Technical Reports Server (NTRS)

Knoll, A. H.; Strother, P. K.; Rossi, S.

1988-01-01

Two distinct generations of microfossils occur in silicified carbonates from a previously undescribed locality of the Lower Proterozoic Duck Creek Dolomite, Western Australia. The earlier generation occurs in discrete organic-rich clasts and clots characterized by microquartz anhedra; it contains a variety of filamentous and coccoidal fossils in varying states of preservation. Second generation microfossils consist almost exclusively of well-preserved Gunflintia minuta filaments that drape clasts or appear to float in clear chalcedony. These filaments appear to represent an ecologically distinct assemblage that colonized a substrate containing the partially degraded remains of the first generation community. The two assemblages differ significantly in taxonomic frequency distribution from previously described Duck Creek florules. Taken together, Duck Creek microfossils exhibit a range of assemblage variability comparable to that found in other Lower Proterozoic iron formations and ferruginous carbonates. With increasing severity of post-mortem alteration, Duck Creek microfossils appear to converge morphologically on assemblages of simple microstructures described from early Archean cherts. Two new species are described: Oscillatoriopsis majuscula and O. cuboides; the former is among the largest septate filamentous fossils described from any Proterozoic formation.

Body shape changes in the elderly and the influence of density assumptions on segment inertia parameters

NASA Astrophysics Data System (ADS)

Jensen, Robert K.; Fletcher, P.; Abraham, C.

1991-04-01

The segment mass mass proportions and moments of inertia of a sample of twelve females and seven males with mean ages of 67. 4 and 69. 5 years were estimated using textbook proportions based on cadaver studies. These were then compared with the parameters calculated using a mathematical model the zone method. The methodology of the model was fully evaluated for accuracy and precision and judged to be adequate. The results of the comparisons show that for some segments female parameters are quite different from male parameters and inadequately predicted by the cadaver proportions. The largest discrepancies were for the thigh and the trunk. The cadaver predictions were generally less than satisfactory although the common variance for some segments was moderately high. The use ofnon-linear regression and segment anthropometry was illustrated for the thigh moments of inertia and appears to be appropriate. However the predictions from cadaver data need to be examined fully. These results are dependent on the changes in mass and density distribution which occur with aging and the changes which occur with cadaver samples prior to and following death.

The 10 largest public and philanthropic funders of health research in the world: what they fund and how they distribute their funds.

PubMed

Viergever, Roderik F; Hendriks, Thom C C

2016-02-18

Little is known about who the main public and philanthropic funders of health research are globally, what they fund and how they decide what gets funded. This study aims to identify the 10 largest public and philanthropic health research funding organizations in the world, to report on what they fund, and on how they distribute their funds. The world's key health research funding organizations were identified through a search strategy aimed at identifying different types of funding organizations. Organizations were ranked by their reported total annual health research expenditures. For the 10 largest funding organizations, data were collected on (1) funding amounts allocated towards 20 health areas, and (2) schemes employed for distributing funding (intramural/extramural, project/'people'/organizational and targeted/untargeted funding). Data collection consisted of a review of reports and websites and interviews with representatives of funding organizations. Data collection was challenging; data were often not reported or reported using different classification systems. Overall, 55 key health research funding organizations were identified. The 10 largest funding organizations together funded research for $37.1 billion, constituting 40% of all public and philanthropic health research spending globally. The largest funder was the United States National Institutes of Health ($26.1 billion), followed by the European Commission ($3.7 billion), and the United Kingdom Medical Research Council ($1.3 billion). The largest philanthropic funder was the Wellcome Trust ($909.1 million), the largest funder of health research through official development assistance was USAID ($186.4 million), and the largest multilateral funder was the World Health Organization ($135.0 million). Funding distribution mechanisms and funding patterns varied substantially between the 10 largest funders. There is a need for increased transparency about who the main funders of health research are globally, what they fund and how they decide on what gets funded, and for improving the evidence base for various funding models. Data on organizations' funding patterns and funding distribution mechanisms are often not available, and when they are, they are reported using different classification systems. To start increasing transparency in health research funding, we have established www.healthresearchfunders.org that lists health research funding organizations worldwide and their health research expenditures.

Factors affecting variation in CH4 emission from paddy soils grown with different rice cultivars: A pot experiment

NASA Astrophysics Data System (ADS)

Watanabe, Akira; Kimura, Makoto

1998-08-01

The growth of rice plants greatly influences CH4 emission from paddy fields through the supply of organic materials such as root exudates and sloughed tissues, the release of oxygen to the root environment, and the transfer of CH4 from the rhizosphere into the atmosphere through the aerenchyma. In the present pot experiments, the effects of the release of water-soluble organic substances from roots, the air space in roots, and the CH4-oxidizing capacity of roots on intervarietal differences in CH4 emission were examined using three Japonica type cultivars (Norin 25, Nipponbare, and Aoinokaze), which differ in morphological properties. The CH4 emission rates varied among the cultivars from mid-July (tillering stage) to the beginning of September (heading stage).Total CH4 emission throughout the rice growth period was largest for Norin 25, followed by Nipponbare, and Aoinokaze. In August, the rate of release of water-soluble organic substances from roots was largest for Norin 25. The air space in roots was also largest in Norin 25 and least in Aoinokaze. The stable carbon isotopic ratios (δ13C) of CH4 in roots were 3-10‰ higher than those in soil in August. The difference in δ13C values of CH4 between roots and soil was largest for Aoinokaze and smallest for Norin 25. In September, the difference in δ13C values of CH4 between roots and soil became small (2-3‰). These findings suggest that the proportion of CH4 oxidation in the rhizosphere was largest in the cultivar which emitted the smallest amount of CH4 and that the proportion became smaller with continued plant growth.

How do tympanic-membrane perforations affect human middle-ear sound transmission?

PubMed

Voss, S E; Rosowski, J J; Merchant, S N; Peake, W T

2001-01-01

Although tympanic-membrane (TM) perforations are common sequelae of middle-ear disease, the hearing losses they cause have not been accurately determined, largely because additional pathological conditions occur in these ears. Our measurements of acoustic transmission before and after making controlled perforations in cadaver ears show that perforations cause frequency-dependent loss that: (1) is largest at low frequencies; (2) increases as perforation size increases; and (3) does not depend on perforation location. The dominant loss mechanism is the reduction in sound-pressure difference across the TM. Measurements of middle-ear air-space sound pressures show that transmission via direct acoustic stimulation of the oval and round windows is generally negligible. A quantitative model predicts the influence of middle-ear air-space volume on loss; with larger volumes, loss is smaller.

Microhabitat use and diurnal time-activity budgets of White-headed Ducks (Oxyura leucocephala Scopoli, 1769) wintering at Burdur Lake, Turkey.

PubMed

Nergiz, Humeyra; Tabur, Mehmet Ali; Ayvaz, Yusuf

2013-08-01

Diurnal time-activity budgets of White-headed Ducks were investigated with respect to sex and temporal environmental variables to document behavioral responses to winter conditions and nutritional requirements at Burdur Lake where the largest winter concentrations occur. Behaviors of males and females were recorded separately in randomly selected focal flocks during 1140 sessions. For the entire population a large proportion of time was spent resting. During the day they spent 61% of time resting, 22% feeding, 12% comfort and 5% in locomotion. Resting peaked in the middle of day while feeding was observed frequently in evening and morning. Time use did not differ significantly between sexes. However, it was detected that more time was spent feeding during windy days as wave-height increased.

Deterministic and stochastic models for middle east respiratory syndrome (MERS)

NASA Astrophysics Data System (ADS)

Suryani, Dessy Rizki; Zevika, Mona; Nuraini, Nuning

2018-03-01

World Health Organization (WHO) data stated that since September 2012, there were 1,733 cases of Middle East Respiratory Syndrome (MERS) with 628 death cases that occurred in 27 countries. MERS was first identified in Saudi Arabia in 2012 and the largest cases of MERS outside Saudi Arabia occurred in South Korea in 2015. MERS is a disease that attacks the respiratory system caused by infection of MERS-CoV. MERS-CoV transmission occurs directly through direct contact between infected individual with non-infected individual or indirectly through contaminated object by the free virus. Suspected, MERS can spread quickly because of the free virus in environment. Mathematical modeling is used to illustrate the transmission of MERS disease using deterministic model and stochastic model. Deterministic model is used to investigate the temporal dynamic from the system to analyze the steady state condition. Stochastic model approach using Continuous Time Markov Chain (CTMC) is used to predict the future states by using random variables. From the models that were built, the threshold value for deterministic models and stochastic models obtained in the same form and the probability of disease extinction can be computed by stochastic model. Simulations for both models using several of different parameters are shown, and the probability of disease extinction will be compared with several initial conditions.

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

Hamoda, Haitham, E-mail: haithamhamoda@hotmail.co; Tait, P.; Edmonds, D. K.

We report a 44-year-old woman who developed a fatal pulmonary embolus after uterine artery fibroid embolisation (UAE). Bilateral UAE was carried out through a single right-femoral artery puncture. The largest fibroid in the anterior fundal wall measured 4.5 cm, and the largest fibroid in the posterior fundal wall measured 6 cm. The appearances after UAE were satisfactory, and the procedure was apparently uneventful. No immediate complications were noted. The patient developed sudden-onset shortness of breath and went into cardiac arrest 19 h after the procedure. Postmortem autopsy confirmed that the cause of a death was a pulmonary embolism. To ourmore » knowledge this is the first reported case in the United Kingdom in which death occurred from a pulmonary embolus after UAE.« less

Glaciers of South America

USGS Publications Warehouse

Williams, Richard S.; Ferrigno, Jane G.

1998-01-01

Landsat images, together with maps and aerial photographs, have been used to produce glacier inventories, define glacier locations, and study glacier dynamics in the countries of South America, along with the Andes Mountains. In Venezuela, Colombia, Ecuador, and Bolivia, the small glaciers have been undergoing extensive glacier recession since the late 1800's. Glacier-related hazards (outburst floods, mud flows, and debris avalanches) occur in Colombia, in Ecuador, and associated with the more extensive (2,600 km2) glaciers of Peru. The largest area of glacier ice is found in Argentina and Chile, including the northern Patagonian ice field (about 4,200 km2) and the southern Patagonian ice field (about 13,000 km2), the largest glacier in the Southern Hemisphere outside Antarctica.

Qal'eh Hasan Ali maars, central Iran.

USGS Publications Warehouse

Milton, D.J.

1976-01-01

This group of some 15 Late Quaternary explosion craters are typical maars, with rims of bedded pyroclastics. In all but the largest crater, the deposits consist entirely of clasts of country rock (granodiorite and Eocene volcanics). The maars were formed by phreatomagmatic explosions, possibly caused by groundwater originating from a major river. The deposits of the largest maar contain up to 20% juvenile fragments of two types. Tephrite clasts have phenocrysts of phlogopite, clinopyroxene, olivine and anorthoclase; the presence of hauyne as a groundmass phase is notable. Cumulate blocks of phlogopite-clinopyroxene rock also occur. The maar field is part of a distinct province of Quaternary alkaline volcanism, related to a major crustal fracture - the N-S-trending Nayband fault.-R.J.S.

Simulated and measured water levels and estimated water-level changes in the Albuquerque area, central New Mexico, 1950-2012

USGS Publications Warehouse

Rice, Steven E.; Oelsner, Gretchen P.; Heywood, Charles E.

2014-01-01

and again for 2008. Both the water-table elevations and production-zone hydraulic heads declined over time with the largest change occurring between 1970 and 1980, which was a period of rapid population growth and groundwater use. Declines in the water-table elevations and production-zone hydraulic heads are focused around major pumping centers and are largest in the production zone. Hydrographs from nine production-zone piezometers in the modeled area indicated varying responses to the increased use of surface-water diversions during 2009–12, with responses related to the locations of the wells within the study area and their proximity to pumping centers and the Rio Grande.

Climatology of extreme daily precipitation in Colorado and its diverse spatial and seasonal variability

USGS Publications Warehouse

Mahoney, Kelly M.; Ralph, F. Martin; Walter, Klaus; Doesken, Nolan; Dettinger, Michael; Gottas, Daniel; Coleman, Timothy; White, Allen

2015-01-01

The climatology of Colorado’s historical extreme precipitation events shows a remarkable degree of seasonal and regional variability. Analysis of the largest historical daily precipitation totals at COOP stations across Colorado by season indicates that the largest recorded daily precipitation totals have ranged from less than 60 mm day−1 in some areas to more than 250 mm day−1 in others. East of the Continental Divide, winter events are rarely among the top 10 events at a given site, but spring events dominate in and near the foothills; summer events are most common across the lower-elevation eastern plains, while fall events are most typical for the lower elevations west of the Divide. The seasonal signal in Colorado’s central mountains is complex; high-elevation intense precipitation events have occurred in all months of the year, including summer, when precipitation is more likely to be liquid (as opposed to snow), which poses more of an instantaneous flood risk. Notably, the historic Colorado Front Range daily rainfall totals that contributed to the damaging floods in September 2013 occurred outside of that region’s typical season for most extreme precipitation (spring–summer). That event and many others highlight the fact that extreme precipitation in Colorado has occurred historically during all seasons and at all elevations, emphasizing a year-round statewide risk.

Precipitation chemistry at the Marcell Experimental Forest in north central Minnesota

Treesearch

Elon S. Verry

1983-01-01

Concentration (milligrams and microequivalents per liter) values are presented for major ions occurring in rain and snow from July 1978 to July 1980. Ammonium, sodium, and calcium are the largest equivalent weight cations which are largely balanced by sulfate and nitrate anions. Hydrogen is the fourth most abundant cation; but high combined concentrations of other...

Impacts of the Deepwater Horizon oil spill on blue crab, Callinectes sapidus, larval settlement in Mississippi

EPA Science Inventory

The largest accidental release of crude oil in history occurred in the north-central Gulf of Mexico (GOM) between April 20 and July 15, 2010 (Alford et al., this volume). The DWH spill was unprecedented due to both its magnitude (>600,000 metric tons released) and its occurren...

Bark beetle outbreaks in western North America: Causes and consequences

Treesearch

Barbara Bentz; Jesse Logan; Jim MacMahon; Craig D. Allen; Matt Ayres; Ed Berg; Allan Carroll; Matt Hansen; Jeff Hicke; Linda Joyce; Wallace Macfarlane; Steve Munson; Jose Negron; Tim Paine; Jim Powell; Ken Raffa; Jacques Regniere; Mary Reid; Bill Romme; Steven J. Seybold; Diana Six; Diana Tomback; Jim Vandygriff; Tom Veblen; Mike White; Jeff Witcosky; David Wood

2009-01-01

Since 1990, native bark beetles have killed billions of trees across millions of acres of forest from Alaska to northern Mexico. Although bark beetle infestations are a regular force of natural change in forested ecosystems, several of the current outbreaks, which are occurring simultaneously across western North America, are the largest and most severe in recorded...

Using Cross-Curricular Ideas to Infuse Paralympic Sport

ERIC Educational Resources Information Center

Tepfer, Amanda T. S.; Lieberman, Lauren J.

2012-01-01

The Paralympic Games are the second largest sport event in the world. They occur two weeks after the Olympic Games in the same geographic location and sport venues. Despite the Paralympic Games' longevity, many Americans do not even know they exist. One way to meaningfully share information about this event with people of all ages is to infuse a…

Bark beetle outbreaks in western North America: Causes and consequences

USGS Publications Warehouse

Bentz, Barbara; Logan, Jesse; MacMahon, James A.; Allen, Craig D.; Ayres, Matt; Berg, Edward E; Carroll, Allan; Hansen, Matt; Hicke, Jeff H.; Joyce, Linda A.; Macfarlane, Wallace; Munson, Steve; Negron, Jose; Paine, Tim; Powell, Jim; Raffa, Kenneth; Regniere, Jacques; Reid, Mary; Romme, Bill; Seybold, Steven J.; Six, Diana; Vandygriff, Jim; Veblen, Tom; White, Mike; Witcosky, Jeff

2005-01-01

Since 1990, native bark beetles have killed billions of trees across millions of acres of forest from Alaska to northern Mexico. Although bark beetle infestations are a regular force of natural change in forested ecosystems, several of the current outbreaks, which are occurring simultaneously across western North America, are the largest and most severe in recorded history.

Nanoindentation methods for wood-adhesive bond lines

Treesearch

Joseph E. Jakes; Donald S. Stone; Charles R. Frihart

2008-01-01

As an adherend, wood is structurally, chemically, and mechanically more complex than metals or plastics, and the largest source of this complexity is wood’s chemical and mechanical inhomogeneities. Understanding and predicting the performance of adhesively bonded wood requires knowledge of the interactions occurring at length scales ranging from the macro down to the...

Exploring folate diversity in wild and primitive potatoes for modern crop improvement

USDA-ARS?s Scientific Manuscript database

Malnutrition is one of the world’s largest health concerns. Folate (a.k.a. vitamin B9) is essential in the human diet and without adequate folate intake several serious health concerns such as congenital birth defects and an increased risk of stroke and heart disease can occur. Most people’s folate ...

Visceral mast cell tumor in a captive black jaguar (Panthera onca).

PubMed

de Castro, Márcio Botelho; Werther, Karin; Godoy, Guilherme Sellera; Borges, Vivian Palmeira; Alessi, Antonio Carlos

2003-03-01

Little is known about neoplasia in the jaguar (Panthera onca), the largest American feline. A captive black jaguar was diagnosed at necropsy with a mastocytic form of visceral mast cell tumor similar to that which occurs in domestic cats. This animal had no previous clinical disease and died during anesthesia for a routine dental treatment.

Family Characteristics, Custody Arrangements, and Adolescent Psychological Well-Being after Lesbian Mothers Break up

ERIC Educational Resources Information Center

Gartrell, Nanette; Bos, Henny; Peyser, Heidi; Deck, Amalia; Rodas, Carla

2011-01-01

As part of the largest, longest running prospective American study of same-sex parent families, the present investigation examined relationship dissolution in planned lesbian families. Data were collected from 40 separated couples and their 17-year-old adolescent offspring--19 girls and 21 boys. Nearly all breakups occurred before the former…

West Nile Virus Outbreak in Houston and Harris County, Texas, USA, 2014.

PubMed

Martinez, Diana; Murray, Kristy O; Reyna, Martin; Arafat, Raouf R; Gorena, Roberto; Shah, Umair A; Debboun, Mustapha

2017-08-01

Since 2002, West Nile virus (WNV) has been detected every year in Houston and the surrounding Harris County, Texas. In 2014, the largest WNV outbreak to date occurred, comprising 139 cases and causing 2 deaths. Additionally, 1,286 WNV-positive mosquito pools were confirmed, the most reported in a single mosquito season.

Periodical Cicada--Brood V (Pest Alert)

Treesearch

USDA Forest Service

1999-01-01

Three separate species of periodical cicadas, Magicicada septendecim (L.), M. cassini (Fisher), and M. septendecula (Alexander and Moore), will appear this spring over large portions of Ohio and West Virginia during the scheduled Brood V emergence. This brood is the largest that occurs in either state and was last seen in 1982. It will also emerge in the southwest...

HYDROGEOLOGICAL AND GEOCHEMICAL FACTORS INFLUENCING MERCURY FATE AND TRANSPORT AT THE SULPHUR BANK MERCURY MINE, LAKE COUNTY, CALIFORNIA

EPA Science Inventory

Clear Lake, located approximately 150 km north of San Francisco in Lake County, is one of the largest fresh water lakes in the California. Elevated mercury levels were first identified in fish from Clear Lake in the late 1970s and early 1980s. Although naturally occurring mercury...

Threatened fishes of the world: Alosa alabamae (Jordan and Evermann, 1896) (Clupeidae)

Treesearch

Dwayne W. Meadows; Susan B. Adams; Jacob F. Schaefer

2007-01-01

River drainage to the Suwannee River, Florida (Mettee and O'Neil 2003); extirpated from at least 8 of the 14 native states (Mettee and O'Neil 2003). Abundance: Once commercially harvested, now rare (Mettee and O'Neil 2003); largest remaining population occurs in the Apalachicola River, Florida (Barku-100 et a!. 1993). Habitat...

IQ variations across time, race, and nationality: an artifact of differences in literacy skills.

PubMed

Marks, David F

2010-06-01

A body of data on IQ collected over 50 years has revealed that average population IQ varies across time, race, and nationality. An explanation for these differences may be that intelligence test performance requires literacy skills not present in all people to the same extent. In eight analyses, population mean full scale IQ and literacy scores yielded correlations ranging from .79 to .99. In cohort studies, significantly larger improvements in IQ occurred in the lower half of the IQ distribution, affecting the distribution variance and skewness in the predicted manner. In addition, three Verbal subscales on the WAIS show the largest Flynn effect sizes and all four Verbal subscales are among those showing the highest racial IQ differences. This pattern of findings supports the hypothesis that both secular and racial differences in intelligence test scores have an environmental explanation: secular and racial differences in IQ are an artifact of variation in literacy skills. These findings suggest that racial IQ distributions will converge if opportunities are equalized for different population groups to achieve the same high level of literacy skills. Social justice requires more effective implementation of policies and programs designed to eliminate inequities in IQ and literacy.

Characterising the variations in ethnic skin colours: a new calibrated data base for human skin.

PubMed

Xiao, K; Yates, J M; Zardawi, F; Sueeprasan, S; Liao, N; Gill, L; Li, C; Wuerger, S

2017-02-01

Accurate skin colour measurements are important for numerous medical applications including the diagnosis and treatment of cutaneous disorders and the provision of maxillofacial soft tissue prostheses. In this study, we obtained accurate skin colour measurements from four different ethnic groups (Caucasian, Chinese, Kurdish, Thai) and at four different body locations (Forehead, cheek, inner arm, back of hand) with a view of establishing a new skin colour database for medical and cosmetic applications. Skin colours are measured using a spectrophotometer and converted to a device-independent standard colour appearance space (CIELAB) where skin colour is expressed as values along the three dimensions: Lightness L*, Redness a* and Yellowness b*. Skin colour differences and variation are then evaluated as a function of ethnicity and body location. We report three main results: (1) When plotted in a standard colour appearance space (CIELAB), skin colour distributions for the four ethnic groups overlap significantly, although there are systematic mean differences. Between ethnicities, the most significant skin colour differences occur along the yellowness dimension, with Thai skin exhibiting the highest yellowness (b*) value and Caucasian skin the lowest value. Facial redness (a*) is invariant across the four ethnic groups. (2) Between different body locations, there are significant variations in redness (a*), with the forehead showing the highest redness value and the inner arm the lowest. (3) The colour gamut is smallest in the Chinese sample and largest in the Caucasian sample, with the Chinese gamut lying entirely the Caucasian gamut. Similarly, the largest variability in skin tones is found in the Caucasian group, and the smallest in the Chinese group. Broadly speaking, skin colour variation can be explained by two main factors: individual differences in lightness and yellowness are mostly due to ethnicity, whereas differences in redness are primarily due to different body locations. Variations in lightness are more idiosyncratic probably reflecting the large influence of environmental factors such as exposure to sun. © 2016 The Authors. Skin Research and Technology Published by John Wiley & Sons Ltd.

Impact of a hospitalist system on length of stay and cost for children with common conditions.

PubMed

Srivastava, Rajendu; Landrigan, Christopher P; Ross-Degnan, Dennis; Soumerai, Stephen B; Homer, Charles J; Goldmann, Donald A; Muret-Wagstaff, Sharon

2007-08-01

This study examined mechanisms of efficiency in a managed care hospitalist system on length of stay and total costs for common pediatric conditions. We conducted a retrospective cohort study (October 1993 to July 1998) of patients in a not-for-profit staff model (HMO 1) and a non-staff-model (HMO 2) managed care organization at a freestanding children's hospital. HMO 1 introduced a hospitalist system for patients in October 1996. Patients were included if they had 1 of 3 common diagnoses: asthma, dehydration, or viral illness. Linear regression models examining length-of-stay-specific costs for prehospitalist and posthospitalist systems were built. Distribution of length of stay for each diagnosis before and after the system change in both study groups was calculated. Interrupted time series analysis tested whether changes in the trends of length of stay and total costs occurred after implementation of the hospitalist system by HMO1 (HMO 2 as comparison group) for all 3 diagnoses combined. A total of 1970 patients with 1 of the 3 study conditions were cared for in HMO 1, and 1001 in HMO 2. After the hospitalist system was introduced in HMO 1, length of stay was reduced by 0.23 days (13%) for asthma and 0.19 days (11%) for dehydration; there was no difference for patients with viral illness. The largest relative reduction in length of stay occurred in patients with a shorter length of stay whose hospitalizations were reduced from 2 days to 1 day. This shift resulted in an average cost-per-case reduction of $105.51 (9.3%) for patients with asthma and $86.22 (7.8%) for patients with dehydration. During the same period, length of stay and total cost rose in HMO 2. Introduction of a hospitalist system in one health maintenance organization resulted in earlier discharges and reduced costs for children with asthma and dehydration compared with another one, with the largest reductions occurring in reducing some 2-day hospitalizations to 1 day. These findings suggest that hospitalists can increase efficiency and reduce costs for children with common pediatric conditions.

Gas-liquid nucleation at large metastability: unusual features and a new formalism

NASA Astrophysics Data System (ADS)

Santra, Mantu; Singh, Rakesh S.; Bagchi, Biman

2011-03-01

Nucleation at large metastability is still largely an unsolved problem, even though it is a problem of tremendous current interest, with wide-ranging practical value, from atmospheric research to materials science. It is now well accepted that the classical nucleation theory (CNT) fails to provide a qualitative picture and gives incorrect quantitative values for such quantities as activation-free energy barrier and supersaturation dependence of nucleation rate, especially at large metastability. In this paper, we present an alternative formalism to treat nucleation at large supersaturation by introducing an extended set of order parameters in terms of the kth largest liquid-like clusters, where k = 1 is the largest cluster in the system, k = 2 is the second largest cluster and so on. At low supersaturation, the size of the largest liquid-like cluster acts as a suitable order parameter. At large supersaturation, the free energy barrier for the largest liquid-like cluster disappears. We identify this supersaturation as the one at the onset of kinetic spinodal. The kinetic spinodal is system-size-dependent. Beyond kinetic spinodal many clusters grow simultaneously and competitively and hence the nucleation and growth become collective. In order to describe collective growth, we need to consider the full set of order parameters. We derive an analytic expression for the free energy of formation of the kth largest cluster. The expression predicts that, at large metastability (beyond kinetic spinodal), the barrier of growth for several largest liquid-like clusters disappears, and all these clusters grow simultaneously. The approach to the critical size occurs by barrierless diffusion in the cluster size space. The expression for the rate of barrier crossing predicts weaker supersaturation dependence than what is predicted by CNT at large metastability. Such a crossover behavior has indeed been observed in recent experiments (but eluded an explanation till now). In order to understand the large numerical discrepancy between simulation predictions and experimental results, we carried out a study of the dependence on the range of intermolecular interactions of both the surface tension of an equilibrium planar gas-liquid interface and the free energy barrier of nucleation. Both are found to depend significantly on the range of interaction for the Lennard-Jones potential, both in two and three dimensions. The value of surface tension and also the free energy difference between the gas and the liquid phase increase significantly and converge only when the range of interaction is extended beyond 6-7 molecular diameters. We find, with the full range of interaction potential, that the surface tension shows only a weak dependence on supersaturation, so the reason for the breakdown of CNT (with simulated values of surface tension and free energy gap) cannot be attributed to the supersaturation dependence of surface tension. This remains an unsettled issue at present because of the use of the value of surface tension obtained at coexistence.

Hydrologic conditions and hazards in the Kennicott River basin, Wrangell-St. Elias National Park Preserve, Alaska

USGS Publications Warehouse

Rickman, R.L.; Rosenkrans, D.S.

1997-01-01

McCarthy, Alaska, is on the Kennicott River, about 1 mile from the terminus of Kennicott Glacier in the Wrangell-St. Elias National Park and Preserve. Most visitors to McCarthy and the park cross the West Fork Kennicott River using a hand-pulled tram and cross the East Fork Kennicott River on a temporary footbridge. Outburst floods from glacier-dammed lakes result in channel erosion, aggradation, and migration of the Kennicott River, which disrupt transportation links, destroy property, and threaten life. Hidden Creek Lake, the largest of six glacier-dammed lakes in the Kennicott River Basin, has annual outbursts that cause the largest floods on the Kennicott River. Outbursts from Hidden Creek Lake occur from early fall to mid-summer, and lake levels at the onset of the outbursts have declined between 1909 and 1995. Criteria for impending outbursts for Hidden Creek Lake include lake stage near or above 3,000 to 3,020 feet, stationary or declining lake stage, evidence of recent calving of large ice blocks from the ice margin, slush ice and small icebergs stranded on the lakeshore, and fresh fractures in the ice-margin region. The lower Kennicott Glacier has thinned and retreated since about 1860. The East and West Fork Kennicott River channels migrated in response to changes in the lower Kennicott Glacier. The largest channel changes occur during outburst floods from Hidden Creek Lake, whereas channel changes from the other glacier-dammed lake outbursts are small. Each year, the West Fork Kennicott River conveys a larger percentage of the Kennicott Glacier drainage than it did the previous year. Outburst floods on the Kennicott River cause the river stage to rise over a period of several hours. Smaller spike peaks have a very rapid stage rise. Potential flood magnitude was estimated by combining known maximum discharges from Hidden Creek Lake and Lake Erie outburst floods with a theoretical large regional flood. Flood hazard areas at the transportation corridor were delineated, and possible future geomorphological changes were hypothesized. McCarthy, Alaska, is on the Kennicott River, about 1 mile from the terminus of Kennicott Glacier in the Wrangell-St. Elias National Park and Preserve. Most visitors to McCarthy and the park cross the West Fork Kennicott River using a hand-pulled tram and cross the East Fork Kennicott River on a temporary footbridge. Outburst floods from glacier-dammed lakes result in channel erosion, aggradation, and migration of the Kennicott River, which disrupt transportation links, destroy property, and threaten life. Hidden Creek Lake, the largest of six glacier-dammed lakes in the Kennicott River Basin, has annual outbursts that cause the largest floods on the Kennicott River. Outbursts from Hidden Creek Lake occur from early fall to mid-summer, and lake levels at the onset of the outbursts have declined between 1909 and 1995. Criteria for impending outbursts for Hidden Creek Lake include lake stage near or above 3,000 to 3,020 feet, stationary or declining lake stage, evidence of recent calving of large ice blocks from the ice margin, slush ice and small icebergs stranded on the lakeshore, and fresh fractures in the ice-margin region. The lower Kennicott Glacier has thinned and retreated since about 1860. The East and West Fork Kennicott River channels migrated in response to changes in the lower Kennicott Glacier. The largest channel changes occur during outburst floods from Hidden Creek Lake, whereas channel changes from the other glacier-dammed lake outbursts are small. Each year, the West Fork Kennicott River conveys a larger percentage of the Kennicott Glacier drainage than it did the previous year. Outburst floods on the Kennicott River cause the river stage to rise over a period of several hours. Smaller spike peaks have a very rapid stage rise. Potential flood magnitude was estimated by combining known maximum discharges from Hidden Creek Lake and Lake Erie outburst floods with

Time-dependent gravity in Southern California, May 1974 to April 1979

NASA Technical Reports Server (NTRS)

Whitcomb, J. H.; Franzen, W. O.; Given, J. W.; Pechmann, J. C.; Ruff, L. J.

1980-01-01

The Southern California gravity survey, begun in May 1974 to obtain high spatial and temporal density gravity measurements to be coordinated with long-baseline three dimensional geodetic measurements of the Astronomical Radio Interferometric Earth Surveying project, is presented. Gravity data was obtained from 28 stations located in and near the seismically active San Gabriel section of the Southern California Transverse Ranges and adjoining San Andreas Fault at intervals of one to two months using gravity meters relative to a base station standard meter. A single-reading standard deviation of 11 microGal is obtained which leads to a relative deviation of 16 microGal between stations, with data averaging reducing the standard error to 2 to 3 microGal. The largest gravity variations observed are found to correlate with nearby well water variations and smoothed rainfall levels, indicating the importance of ground water variations to gravity measurements. The largest earthquake to occur during the survey, which extended to April, 1979, is found to be accompanied in the station closest to the earthquake by the largest measured gravity changes that cannot be related to factors other than tectonic distortion.

First Protein Crystallization Experiments on The International Space Station: Sweet Success in Space With Thaumatin

NASA Technical Reports Server (NTRS)

Kundrot, Craig E.; Barnes, Cindy L.; Snell, Eddie H.; Achari, Aniruddha; Whitaker, Ann F. (Technical Monitor)

2001-01-01

We determined the room temperature 1.2 A structure of thaumatin using a crystal grown in the first protein crystallization experiment conducted aboard the International Space Station (ISS). The crystals were grown in the Enhanced Gaseous Nitrogen Dewar (EGN) developed by Alexander McPherson and co-workers. EGN transports frozen solutions contained in tygon tubing in a liquid nitrogen Dewar to ISS where the tubes then thaw. Batch, free interface diffusion (FID), or vapor diffusion crystallization occurs after thawing. EGN was flown to the ISS on STS-106 on September 8, 2000. This was a "risk mitigation" flight that tested EGN performance and the process of conducting experiments on ISS. We focused on how to map a hanging drop crystallization recipe to the EGN FID method. Thaumatin was chosen as the test system. Three series of crystallization recipes were set-up. Each series tested different volume ratios of protein-rich solution to precipitant-rich solution. The series differed from each other by fixing either the protein concentration or the amount of protein in the solutions. Upon return of the samples to Earth on October 24 by STS-92, bubbles that spanned the diameter of the tubing were observed in all tubes. Such bubbles interrupt liquid-liquid diffusion and force vapor diffusion equilibration to occur instead. Nonetheless, crystals grew in 9 of 30 tubes. Many large crystals were grown, the largest being 2.0 x 1.1 x 1.0 cubic mm. The largest crystal was used to collect data at room temperature on beamline 7-1 of the Stanford Synchrotron Radiation Source to a maximum resolution of 1.2 A. The structure was refined anisotropically using SHELX with a data to parameter ratio of 4.5 to give an R(sub factor) of 15.8% (R(sub free) = 18.2%) for ail reflections without generated hydrogens. This refinement is proceeding. Comparisons of this 1.2 A microgravity structure to previous reports of the thaumatin structure at 1.75 A and to ground control crystals will be presented.

Large Historical Tsunamigenic Earthquakes in Italy: The Neglected Tsunami Research Point of View

NASA Astrophysics Data System (ADS)

Armigliato, A.; Tinti, S.; Pagnoni, G.; Zaniboni, F.

2015-12-01

It is known that tsunamis are rather rare events, especially when compared to earthquakes, and the Italian coasts are no exception. Nonetheless, a striking evidence is that 6 out of 10 earthquakes occurred in the last thousand years in Italy, and having equivalent moment magnitude equal or larger than 7 where accompanied by destructive or heavily damaging tsunamis. If we extend the lower limit of the equivalent moment magnitude down to 6.5 the percentage decreases (around 40%), but is still significant. Famous events like those occurred on 30 July 1627 in Gargano, on 11 January 1693 in eastern Sicily, and on 28 December 1908 in the Messina Straits are part of this list: they were all characterized by maximum run-ups of several meters (13 m for the 1908 tsunami), significant maximum inundation distances, and large (although not precisely quantifiable) numbers of victims. Further evidences provided in the last decade by paleo-tsunami deposit analyses help to better characterize the tsunami impact and confirm that none of the cited events can be reduced to local or secondary effects. Proper analysis and simulation of available tsunami data would then appear as an obvious part of the correct definition of the sources responsible for the largest Italian tsunamigenic earthquakes, in a process in which different datasets analyzed by different disciplines must be reconciled rather than put into contrast with each other. Unfortunately, macroseismic, seismic and geological/geomorphological observations and data typically are assigned much heavier weights, and in-land faults are often assigned larger credit than the offshore ones, even when evidence is provided by tsunami simulations that they are not at all capable of justifying the observed tsunami effects. Tsunami generation is imputed a-priori to only supposed, and sometimes even non-existing, submarine landslides. We try to summarize the tsunami research point of view on the largest Italian historical tsunamigenic earthquakes; we highlight the open problems, and suggest that tsunami observations and simulations can contribute towards their solution. This study is funded in the frame of the EU Project called ASTARTE - Assessment, STrategy And Risk reduction for Tsunamis in Europe. Grant 603839, 7th FP (ENV.2013.6.4-3).

In vivo six-degree-of-freedom knee-joint kinematics in overground and treadmill walking following total knee arthroplasty.

PubMed

Guan, Shanyuanye; Gray, Hans A; Schache, Anthony G; Feller, Julian; de Steiger, Richard; Pandy, Marcus G

2017-08-01

No data are available to describe six-degree-of-freedom (6-DOF) knee-joint kinematics for one complete cycle of overground walking following total knee arthroplasty (TKA). The aims of this study were firstly, to measure 6-DOF knee-joint kinematics and condylar motion for overground walking following TKA; and secondly, to determine whether such data differed between overground and treadmill gait when participants walked at the same speed during both tasks. A unique mobile biplane X-ray imaging system enabled accurate measurement of 6-DOF TKA knee kinematics during overground walking by simultaneously tracking and imaging the joint. The largest rotations occurred for flexion-extension and internal-external rotation whereas the largest translations were associated with joint distraction and anterior-posterior drawer. Strong associations were found between flexion-extension and adduction-abduction (R 2  = 0.92), joint distraction (R 2  = 1.00), and anterior-posterior translation (R 2  = 0.77), providing evidence of kinematic coupling in the TKA knee. Although the measured kinematic profiles for overground walking were grossly similar to those for treadmill walking, several statistically significant differences were observed between the two conditions with respect to temporo-spatial parameters, 6-DOF knee-joint kinematics, and condylar contact locations and sliding. Thus, caution is advised when making recommendations regarding knee implant performance based on treadmill-measured knee-joint kinematic data. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1634-1643, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Assessment of metal transport into and out of Terrace Reservoir, Conejos County, Colorado, April 1994 through March 1995; interim report

USGS Publications Warehouse

Ferguson, Sheryl; Edelmann, Patrick

1996-01-01

Terrace Reservoir is the primary source of water for crops and livestock in the southwestern part of the San Luis Valley in southern Colorado. Mining activities have occurred in the basin for more than 100 years, and substantial mining of gold has occurred intermittently at the Summitville Mine.Historically, the Summitville Mine site has produced highly acidic, metal-enriched water that drained from the mine site into Wightman Fork and flowed to the Alamosa River and Terrace Reservoir. In 1994, a study was begun as part of risk-assessment and remediation efforts and to evaluate metal transport into and out of Terrace Reservoir. During the study period, the pH immediately upstream from Terrace Reservoir ranged from 4.3 to 7.8. The highest pH occurred during the pre-peak snowmelt period; the lowest pH occurred during storm runoff during summer. Downstream from Terrace Reservoir, the pH ranged from 4.6 to 7.6. The highest pH occurred during the pre-peak snowmelt period, and the lowest pH occurred during summer in mid-July. A comparison of the streamflow hydrographs upstream and downstream from Terrace Reservoir indicated that there was only a small difference between the annual volume of water that entered the reservoir and the annual volume of water that was released from the reservoir. Large spatial and temporal variations in concentrations of the metals of concern occurred during the study.The median and maximum concentrations of dissolved and total aluminum, iron, copper, cadmium, manganese, and zinc were larger upstream from the reservoir than downstream from the reservoir. The largest concentrations of dissolved aluminum, iron, copper, cadmium, manganese, and zinc generally occurred between mid-June and November. Throughout the study, aluminum was transported into the reservoir predominantly in the particulate or suspended form. Downstream from the reservoir, the suspended-aluminum fraction was predominant only during the pre-peak snowmelt and peak snowmelt periods. The temporal variations in the percentage of dissolved and suspended fraction of iron and copper downstream from Terrace Reservoir were similar to the temporal variations that occurred upstream from the reservoir. During the study period, cadmium, manganese, and zinc generally were transported into and out of the reservoir predominantly in the dissolved form. Metal loads varied considerably as a result of changes in streamflow or changes in metal concentrations, or both. The largest daily loads of aluminum, iron, and manganese were transported into and out of Terrace Reservoir during the peak snowmelt period.The reservoir was a sink for an estimated 294 tons of aluminum and 596 tons of iron. However, about 68.5 tons of total aluminum and about 194 tons of total iron were transported out of the reservoir during the study period. During the study period, about 22\\x11tons of total copper remained in the reservoir, and 39 tons was transported downstream from the reservoir. About 47 tons of total manganese and 18 tons of total-zinc loads were transported out of the reservoir; the reservoir was a sink for only a small fraction of total-manganese and -zinc.

Hand injuries from snow blowers: a report of an epidemic.

PubMed

Tetz, D J; Aghababian, R

1995-01-01

During a record snowfall in Worcester, Massachusetts, 11-13 December 1992, 37 male patients with hand injuries suffered during snow blower operation were seen at three area hospitals. Two previous reports describe 13 patients seen over a 3-year period and 28 patients over a 12-year period. This report describes the largest number of hand injuries from snow blowers that have occurred over a 48-hour period. The snow was unusual because of the high water density in the initial 9 inches (23 cm) that fell at an average temperature of 33 degrees F (0.6 degree C) with the final depth of 30 inches (76 cm), causing the machines to become clogged. Patients admitted to reaching into a running machine in 35/37 (95%) cases, 11/37 (30%) claimed the auger and impeller blades were disengaged, and 2/37 (5%) patients claimed their injuries occurred with the engines turned off. All injuries occurred when the patients placed their hands down the chute, contacting the impeller blades. Injuries involved 32 long, 15 ring, 13 index, and five small fingers and ranged from simple lacerations to partial phalangeal amputations. The majority, 27/37 (73%), were managed in emergency departments without interventions in the operating suites. Infection occurred in one patient who had the lesion repaired in the operating suite. As in previous studies, no differences were found for the variables of snow-blower age, type, or horsepower, or on experience level or age of the operators.(ABSTRACT TRUNCATED AT 250 WORDS)

Cancer survival in Europe 1999-2007 by country and age: results of EUROCARE--5-a population-based study.

PubMed

De Angelis, Roberta; Sant, Milena; Coleman, Michel P; Francisci, Silvia; Baili, Paolo; Pierannunzio, Daniela; Trama, Annalisa; Visser, Otto; Brenner, Hermann; Ardanaz, Eva; Bielska-Lasota, Magdalena; Engholm, Gerda; Nennecke, Alice; Siesling, Sabine; Berrino, Franco; Capocaccia, Riccardo

2014-01-01

Cancer survival is a key measure of the effectiveness of health-care systems. EUROCARE-the largest cooperative study of population-based cancer survival in Europe-has shown persistent differences between countries for cancer survival, although in general, cancer survival is improving. Major changes in cancer diagnosis, treatment, and rehabilitation occurred in the early 2000s. EUROCARE-5 assesses their effect on cancer survival in 29 European countries. In this retrospective observational study, we analysed data from 107 cancer registries for more than 10 million patients with cancer diagnosed up to 2007 and followed up to 2008. Uniform quality control procedures were applied to all datasets. For patients diagnosed 2000-07, we calculated 5-year relative survival for 46 cancers weighted by age and country. We also calculated country-specific and age-specific survival for ten common cancers, together with survival differences between time periods (for 1999-2001, 2002-04, and 2005-07). 5-year relative survival generally increased steadily over time for all European regions. The largest increases from 1999-2001 to 2005-07 were for prostate cancer (73.4% [95% CI 72.9-73.9] vs 81.7% [81.3-82.1]), non-Hodgkin lymphoma (53.8% [53.3-54.4] vs 60.4% [60.0-60.9]), and rectal cancer (52.1% [51.6-52.6] vs 57.6% [57.1-58.1]). Survival in eastern Europe was generally low and below the European mean, particularly for cancers with good or intermediate prognosis. Survival was highest for northern, central, and southern Europe. Survival in the UK and Ireland was intermediate for rectal cancer, breast cancer, prostate cancer, skin melanoma, and non-Hodgkin lymphoma, but low for kidney, stomach, ovarian, colon, and lung cancers. Survival for lung cancer in the UK and Ireland was much lower than for other regions for all periods, although results for lung cancer in some regions (central and eastern Europe) might be affected by overestimation. Survival usually decreased with age, although to different degrees depending on region and cancer type. The major advances in cancer management that occurred up to 2007 seem to have resulted in improved survival in Europe. Likely explanations of differences in survival between countries include: differences in stage at diagnosis and accessibility to good care, different diagnostic intensity and screening approaches, and differences in cancer biology. Variations in socioeconomic, lifestyle, and general health between populations might also have a role. Further studies are needed to fully interpret these findings and how to remedy disparities. Italian Ministry of Health, European Commission, Compagnia di San Paolo Foundation, Cariplo Foundation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of preservatives on the accuracy of mid-infrared milk component testing.

PubMed

Barbano, D M; Wojciechowski, K L; Lynch, J M

2010-12-01

Our objective was to determine the effect of commonly used milk preservatives on the accuracy of fat, protein, and lactose content determination in milk by mid-infrared (mid-IR) milk analysis. Two producer raw milks (Holstein and Jersey) and 2 pasteurized modified milks, 1 similar to Holstein milk and 1 similar to Jersey milk were used as the 4 different milk sources. Seven different milk preservative approaches (K(2)Cr(2)O(7) and 6 different bronopol-based preservatives) and a portion of unpreserved milk for each of the 4 different milks sources were tested for fat B, lactose, protein, and fat A. The experiment was replicated 3 times (28 d each) for a total of 84 d. Two mid-infrared (mid-IR) transmittance milk analyzers (an optical and a virtual filter instrument) were used. A large batch of pilot milk was prepared from pasteurized, homogenized, unpreserved whole milk, split into vials, quick frozen by immersion in liquid nitrogen, and transferred into a -80 °C freezer. Pilots were thawed and analyzed on each testing day during the study. Significant increases were observed in all uncorrected readings on the pilot milks over the 84 d of the study, but the increases were gradual and small on each instrument for all components. Results from the study were corrected for these changes. A significant difference in mid-IR fat A readings was observed, whereas no differences were detected for fat B, lactose, or protein between unpreserved and preserved milks containing 0.02% K(2)Cr(2)O(7.) Therefore, K(2)Cr(2)O(7) has little or no effect on mid-IR test results. All bronopol-based preservative approaches in this study differed in mid-IR test results compared with K(2)Cr(2)O(7)-preserved and unpreserved milks, with the largest effect on protein results. Mid-IR uncorrected readings increased with time of refrigerated storage at 4°C for all preservative approaches, with the largest increase for protein. The rate of increase in uncorrected readings with time of storage was always higher for raw milks than for pasteurized milks, and the stability of instrument zero was lower for raw milks than for pasteurized milks. The largest economic effect of a systematic bias caused by a preservative occurs when the milks used for calibration and routine testing for payment do not contain the same preservative or when calibration milks are preserved and milks for routine testing are unpreserved. These effects can create errors in payment for large dairy processing plants ranging from several hundred thousand to over a million dollars annually. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Estimation of Constituent Concentrations, Loads, and Yields in Streams of Johnson County, Northeast Kansas, Using Continuous Water-Quality Monitoring and Regression Models, October 2002 through December 2006

USGS Publications Warehouse

Rasmussen, Teresa J.; Lee, Casey J.; Ziegler, Andrew C.

2008-01-01

Johnson County is one of the most rapidly developing counties in Kansas. Population growth and expanding urban land use affect the quality of county streams, which are important for human and environmental health, water supply, recreation, and aesthetic value. This report describes estimates of streamflow and constituent concentrations, loads, and yields in relation to watershed characteristics in five Johnson County streams using continuous in-stream sensor measurements. Specific conductance, pH, water temperature, turbidity, and dissolved oxygen were monitored in five watersheds from October 2002 through December 2006. These continuous data were used in conjunction with discrete water samples to develop regression models for continuously estimating concentrations of other constituents. Continuous regression-based concentrations were estimated for suspended sediment, total suspended solids, dissolved solids and selected major ions, nutrients (nitrogen and phosphorus species), and fecal-indicator bacteria. Continuous daily, monthly, seasonal, and annual loads were calculated from concentration estimates and streamflow. The data are used to describe differences in concentrations, loads, and yields and to explain these differences relative to watershed characteristics. Water quality at the five monitoring sites varied according to hydrologic conditions; contributing drainage area; land use (including degree of urbanization); relative contributions from point and nonpoint constituent sources; and human activity within each watershed. Dissolved oxygen (DO) concentrations were less than the Kansas aquatic-life-support criterion of 5.0 mg/L less than 10 percent of the time at all sites except Indian Creek, which had DO concentrations less than the criterion about 15 percent of the time. Concentrations of suspended sediment, chloride (winter only), indicator bacteria, and pesticides were substantially larger during periods of increased streamflow. Suspended-sediment concentration was nearly always largest at the Mill Creek site. The Mill Creek watershed is undergoing rapid development that likely contributed to larger sustained sediment concentrations. During most of the time, the smallest sediment concentrations occurred at the Indian Creek site, the most urban of the monitored sites, likely because most of the streamflow originates from wastewater-treatment facilities located just upstream from the monitoring site. However, estimated annual suspended-sediment load and yield were largest annually at the Indian Creek site because of substantial contributions during storm runoff. At least 90 percent of the total annual sediment load in 2005?06 at all five monitoring sites occurred in less than 2 percent of the time, generally associated with large storm runoff. About 50 percent of the 2005 sediment load at the Blue River site occurred during a single 3-day storm, the equivalent of less than 1 percent of the time. Suspended-sediment concentration is statistically related to other water-quality constituents, and these relations have potential implications for implementation of best management practices because, if sediment concentrations are decreased, concentrations of sediment-associated constituents such as suspended solids, some nutrients, and bacteria will also likely decrease. Chloride concentrations were largest at the Indian and Mill Creek sites, the two most urban stream sites which also are most affected by road-salt runoff and wastewater-treatment-facility discharges. Two chloride runoff occurrences in January?February 2005 accounted for 19 percent of the total chloride load in Indian Creek in 2005. Escherichia coli density at the Indian Creek site was nearly always largest of the five sites with a median density more than double that of any other site and 15 times the density at the Blue River site which is primarily nonurban. More than 97 percent of the fecal coliform bacteria load at the Indian Creek site and near the B

Post ablation recanalization of varicose veins of the limbs: Comparison ablation method of mechanochemical and laser procedure

NASA Astrophysics Data System (ADS)

Suhartono, R.; Irfan, W.; Wangge, G.; Moenadjat, Y.; Destanto, W. I.

2017-08-01

Endovenous ablation has been performed for varicose veins of the limbs in Indonesia since 2010. Endovenous laser ablation (EVLA) therapy has been performed in Cipto Mangunkusumo Hospital (RSCM) in Jakarta, and mechanochemical ablation (MOCA) has been conducted in Fatmawati Hospital. This was a descriptive analytical study, with a cross-sectional design to analyze post-ablation recanalization after MOCA and EVLA procedures. Patients who had undergone MOCA or EVLA treatment were interviewed 3-18 months after the procedures. All the patients underwent vascular ultrasonography (USG) of the operated limb to assess recanalization. Secondary presurgery data were obtained from the patients’ from patients’ medical records. The clinical characteristics of the subjects were recorded to compare the potential correlation between these characteristics and recanalization post-MOCA and EVLA procedures. All the data were analyzed using SPSS ver. 20.0. The study consisted of 43 limbs: 24 treated by MOCA and 19 treated by EVLA. Most subjects in the MOCA group were <60 years (20/24), and 16 of the subjects were women. In the EVLA group, nine patients were <60 years, and 19 were ≥60 years, 15 of whom were women. The body mass index (BMI) of the majority (18/24) of the subjects in the MOCA group was normal, whereas most of the patients in the EVLA (10/19) group were overweight. In the MOCA group, the largest diameter of the vena saphena magna (VSM) in 20/24 extremities prior to treatment was VSM 4-7 mm, whereas the largest diameter in the EVLA group prior to treatment was >7 mm in 13/19 extremities. In the MOCA group, total recanalization occurred in 2/24 extremities, and partial recanalization occurred in 8/24 extremities. In the EVLA group, total recanalization occurred in 1/19 extremities, and partial recanalization occurred in 3/19 extremities. The association between the clinical characteristics of the patients and recanalization was not statistically significant (p > 0.05). The recanalization tendency was higher in the MOCA group than in the EVLA group. Although there was no statistically significant association between the clinical characteristics of the patients and recanalization, the largest diameter of the VSM presurgery (>7 mm) was higher in 3/4 extremities in the MOCA group, as compared to 3/13 extremities in the EVLA group.

The classification and assessment of vulnerability of man-land system of oasis city in arid area

NASA Astrophysics Data System (ADS)

Gao, Chao; Lei, Jun; Jin, Fengjun

2013-12-01

Oasis city system is the center of the man-land relationship in arid area and it is the most influential spatial and temporal multiple dynamic system. Oasis city system is not only the largest area where artificial disturbances occur at a regional scale but also the most concentrated area of human activity in arid area. In this study, we developed an applicable and convenient method to assess vulnerability of man-land system of oasis cities with vulnerability indicator system, respectively evaluating the sensitivity, adaptability and vulnerability of the eco-environment system, the economic system and the social system. The results showed that the sensitivity and vulnerability of oasis cities in Xinjiang, China have significant differences while their adaptability does little. In order to find the inherent differences in the vulnerability of oasis cities, triangle methodology has been adopted to divide Xinjiang oasis cities into five types. Some adaptive developing policies specific for individual cities are also proposed based on their vulnerability type and constraining factors.

Regional material flow accounting and environmental pressures: the Spanish case.

PubMed

Sastre, Sergio; Carpintero, Óscar; Lomas, Pedro L

2015-02-17

This paper explores potential contributions of regional material flow accounting to the characterization of environmental pressures. With this aim, patterns of material extraction, trade, consumption, and productivity for the Spanish regions were studied within the 1996-2010 period. The main methodological variation as compared to whole-country based approaches is the inclusion of interregional trade, which can be separately assessed from the international exchanges. Each region was additionally profiled regarding its commercial exchanges with the rest of the regions and the rest of the world and the related environmental pressures. Given its magnitude, interregional trade is a significant source of environmental pressure. Most of the exchanges occur across regions and different extractive and trading patterns also arise at this scale. These differences are particularly great for construction minerals, which in Spain represent the largest share of extracted and consumed materials but do not cover long distances, so their impact is visible mainly at the regional level. During the housing bubble, economic growth did not improve material productivity.

Influence of container shape on scaling of turbulent fluctuations in convection

NASA Astrophysics Data System (ADS)

Foroozani, N.; Niemela, J. J.; Armenio, V.; Sreenivasan, K. R.

2014-12-01

We perform large-eddy simulations of turbulent convection in a cubic cell for Rayleigh numbers, Ra, between 106 and 1010 and the molecular Prandtl number, Pr=0.7 . The simulations were carried out using a second-order-accurate finite-difference method in which subgrid-scale fluxes of momentum and heat were both parametrized using a Lagrangian and dynamic Smagorinsky model. The scaling of the root-mean-square fluctuations of density (temperature) and velocity measured in the cell center are in excellent agreement with the scaling measured in the laboratory experiments of Daya and Ecke [Phys. Rev. Lett. 87, 184501 (2001), 10.1103/PhysRevLett.87.184501] and differ substantially from that observed in cylindrical cells. We also observe the time-averaged spatial distributions of the local heat flux and density fluctuations, and find that they are strongly inhomogeneous in the horizontal midplane, with the largest density gradients occurring at the corners at the midheight, where hot and cold plumes mix in the form of strong counter-rotating eddies.

Remotely triggered microearthquakes and tremor in central California following the 2010 Mw 8.8 Chile earthquake

USGS Publications Warehouse

Peng, Zhigang; Hill, David P.; Shelly, David R.; Aiken, Chastity

2010-01-01

We examine remotely triggered microearthquakes and tectonic tremor in central California following the 2010 Mw 8.8 Chile earthquake. Several microearthquakes near the Coso Geothermal Field were apparently triggered, with the largest earthquake (Ml 3.5) occurring during the large-amplitude Love surface waves. The Chile mainshock also triggered numerous tremor bursts near the Parkfield-Cholame section of the San Andreas Fault (SAF). The locally triggered tremor bursts are partially masked at lower frequencies by the regionally triggered earthquake signals from Coso, but can be identified by applying high-pass or matched filters. Both triggered tremor along the SAF and the Ml 3.5 earthquake in Coso are consistent with frictional failure at different depths on critically-stressed faults under the Coulomb failure criteria. The triggered tremor, however, appears to be more phase-correlated with the surface waves than the triggered earthquakes, likely reflecting differences in constitutive properties between the brittle, seismogenic crust and the underlying lower crust.

Analysis/forecast experiments with a flow-dependent correlation function using FGGE data

NASA Technical Reports Server (NTRS)

Baker, W. E.; Bloom, S. C.; Carus, H.; Nestler, M. S.

1986-01-01

The use of a flow-dependent correlation function to improve the accuracy of an optimum interpolation (OI) scheme is examined. The development of the correlation function for the OI analysis scheme used for numerical weather prediction is described. The scheme uses a multivariate surface analysis over the oceans to model the pressure-wind error cross-correlation and it has the ability to use an error correlation function that is flow- and geographically-dependent. A series of four-day data assimilation experiments, conducted from January 5-9, 1979, were used to investigate the effect of the different features of the OI scheme (error correlation) on forecast skill for the barotropic lows and highs. The skill of the OI was compared with that of a successive correlation method (SCM) of analysis. It is observed that the largest difference in the correlation statistics occurred in barotropic and baroclinic lows and highs. The comparison reveals that the OI forecasts were more accurate than the SCM forecasts.

Influence of container shape on scaling of turbulent fluctuations in convection.

PubMed

Foroozani, N; Niemela, J J; Armenio, V; Sreenivasan, K R

2014-12-01

We perform large-eddy simulations of turbulent convection in a cubic cell for Rayleigh numbers, Ra, between 10(6) and 10(10) and the molecular Prandtl number, Pr=0.7. The simulations were carried out using a second-order-accurate finite-difference method in which subgrid-scale fluxes of momentum and heat were both parametrized using a Lagrangian and dynamic Smagorinsky model. The scaling of the root-mean-square fluctuations of density (temperature) and velocity measured in the cell center are in excellent agreement with the scaling measured in the laboratory experiments of Daya and Ecke [Phys. Rev. Lett. 87, 184501 (2001)] and differ substantially from that observed in cylindrical cells. We also observe the time-averaged spatial distributions of the local heat flux and density fluctuations, and find that they are strongly inhomogeneous in the horizontal midplane, with the largest density gradients occurring at the corners at the midheight, where hot and cold plumes mix in the form of strong counter-rotating eddies.

Analysis of Protein Thermostability Enhancing Factors in Industrially Important Thermus Bacteria Species

PubMed Central

Kumwenda, Benjamin; Litthauer, Derek; Bishop, Özlem Tastan; Reva, Oleg

2013-01-01

Elucidation of evolutionary factors that enhance protein thermostability is a critical problem and was the focus of this work on Thermus species. Pairs of orthologous sequences of T. scotoductus SA-01 and T. thermophilus HB27, with the largest negative minimum folding energy (MFE) as predicted by the UNAFold algorithm, were statistically analyzed. Favored substitutions of amino acids residues and their properties were determined. Substitutions were analyzed in modeled protein structures to determine their locations and contribution to energy differences using PyMOL and FoldX programs respectively. Dominant trends in amino acid substitutions consistent with differences in thermostability between orthologous sequences were observed. T. thermophilus thermophilic proteins showed an increase in non-polar, tiny, and charged amino acids. An abundance of alanine substituted by serine and threonine, as well as arginine substituted by glutamine and lysine was observed in T. thermophilus HB27. Structural comparison showed that stabilizing mutations occurred on surfaces and loops in protein structures. PMID:24023508

A Needle in a Haystack: A Search for Value for Money in Turn-Around Strategies for Schools in Difficult Circumstances

ERIC Educational Resources Information Center

Khupe, Constance; Balkwill, Kevin; Osman, Ruksana; Cameron, Ann

2013-01-01

Background: While current investments in school improvement occur in the context of the worldwide economic downturn, in the South African context, there is in addition widespread disparity in education provision and attainment related to pre-democracy race-based patterns. Despite the education sector receiving the largest national annual budget…

A resource at the crossroads: a history of the central hardwoods

Treesearch

Ray R., Jr. Hicks

1997-01-01

The Central Hardwood Forest is an oak dominated deciduous forest that stretches from Massachusetts to Arkansas and occurs in hilly to mountainous terrain. It is the largest and most extensive temperate deciduous forest in the world. During the past 20 million years or so, angiosperms have been gradually replacing gymnosperms as the dominant plant form on earth, and...

Climate Change and the Nation's Forests: Challenges and Opportunities

Treesearch

Dale Bosworth; Richard Birdsey; Linda Joyce; Constance Millar

2008-01-01

Climate change is already affecting America's forests. The fires of 2000 shocked the Nation, the fires of 2006 burned an area greater than in any year since 1954, and the 2007 fires in southern California forced the evacuation of more than a million residents. Some of the largest individual fires ever recorded in the Western United States and Alaska occurred in...

Teaching Primary School Children about Japan through Art. ERIC Digest.

ERIC Educational Resources Information Center

Ward, Patricia Berg

There are a variety reasons for teaching about Japan. Many students in the United States are of Japanese heritage; Japan is the second largest trading partner of the United States; and some healing still needs to occur between the United States and Japan because of the damage and pain of World War II. Further, the Unites States and Japan share the…

Resistance to rocuronium of rat diaphragm as compared with limb muscles.

PubMed

Huang, Lina; Yang, Meirong; Chen, Lianhua; Li, Shitong

2014-12-01

Skeletal muscles are composed of different muscle fiber types. We investigated the different potency to rocuronium among diaphragm (DIA), extensor digitorum longus (EDL), and soleus (SOL) in vitro as well as to investigate the differences of acetylcholine receptors (AChRs) among these three typical kinds of muscles. The isolated left hemidiaphragm nerve-muscle preparations, the EDL sciatic nerve-muscle preparations, and the SOL sciatic nerve-muscle preparations were established to evaluate the potency to rocuronium. Concentration-response curves were constructed and the values of IC50 were obtained. The density of AChRs at the end plate and the number of AChRs per unit fiber cross fiber area (CSA), AChR affinity for muscle relaxants were evaluated. The concentration-twitch tension curves of rocuronium were significantly different. The curves demonstrated a shift to the right of the DIA compared with the EDL and SOL (P < 0.01), whereas no significant difference was observed between EDL and SOL (P > 0.05). IC50 was significantly largest in DIA, second largest in SOL, and smallest in EDL (P < 0.05). The number of AChRs per unit fiber CSA was largest in DIA, second largest in EDL, and smallest in SOL (P < 0.01 or P < 0.05). The DIA showed the lowest affinity of the AChRs, whereas the SOL showed the highest affinity. The resistance to rocuronium of DIA compared with EDL and SOL was verified. The DIA was characterized by the largest number of AChRs per unit fiber CSA and the lowest affinity of the AChRs. Although compared with SOL, EDL was proved to have larger number of AChRs per unit fiber CSA and the lower affinity of the AChRs. These findings may be the mechanisms of different potency to rocuronium in DIA, EDL, and SOL. The results of the study could help to explain the relationship between different composition of muscle fibers and the potency to muscle relaxants. Extra caution should be taken in clinical practice when monitoring muscle relaxation in anesthetic management using different muscles. Copyright © 2014 Elsevier Inc. All rights reserved.

Retrospective review of pediatric oral lesions from a dental school biopsy service.

PubMed

Shah, Suhani K; Le, Mary C; Carpenter, William M

2009-01-01

This report presents a review of the results from 5457 biopsies of patients, 0-16 years of age, received over 15 years at the University of the Pacific School of Dentistry (Pacific Oral and Maxillofacial Pathology Laboratory). To carry out the largest and most up to date U.S. survey of oral specimens from children. The computerized data was retrieved and compiled for age and diagnoses. The lesions were divided by the MIND classification system into 1) Metabolic 2) Inflammatory 3) Neoplastic and 4) Developmental. Inflammatory lesions formed the largest group of biopsies (2758, 51%) followed by Developmental conditions (1928, 35%) and Neoplasms (734, 13%). Dentigerous cysts were the most common lesions, followed by the mucous retention phenomenon (mucocele). The 15 most frequently occurring lesions accounted for 80% of all biopsies. Eight malignancies and 22 benign aggressive tumors were also included. 1. Pathoses increase with age. 2. Results from our study are similar to most of the other studies. 3. More serious pathoses occur in some countries where there is limited access to care, resulting in patients seeking care only when symptomatic. 4. Oral malignancies are rare, but as with any malignancy, early diagnosis renders a more favorable prognosis.

Short-period atmospheric gravity waves - A study of their statistical properties and source mechanisms

NASA Technical Reports Server (NTRS)

Gedzelman, S. D.

1983-01-01

Gravity waves for the one year period beginning 19 October 1976 around Palisades, New York, are investigated to determine their statistical properties and sources. The waves have typical periods of 10 min, pressure amplitudes of 3 Pa and velocities of 30 m/s. In general, the largest, amplitude waves occur during late fall and early winter when the upper tropospheric winds directly overhead are fastest and the static stability of the lower troposphere is greatest. Mean wave amplitudes correlate highly with the product of the mean maximum wind speed and the mean low level stratification directly aloft. A distinct diurnal variation of wave amplitudes with the largest waves occurring in the pre-dawn hours is also observed as a result of the increased static stability then. The majority of waves are generated by shear instability; however, a number of waves are generated by distant sources such as nuclear detonations or large thunderstorms. The waves with distant sources can be distinguished on the basis of their generally much higher coherency across the grid and velocities that depart markedly from the wind velocity at any point in the sounding.

Seismicity of the Earth 1900-2010 eastern margin of the Australia plate

USGS Publications Warehouse

Benz, Harley M.; Herman, Matthew; Tarr, Arthur C.; Hayes, Gavin P.; Furlong, Kevin P.; Villaseñor, Antonio; Dart, Richard L.; Rhea, Susan

2011-01-01

The eastern margin of the Australia plate is one of the most seismically active areas of the world due to high rates of convergence between the Australia and Pacific plates. In the region of New Zealand, the 3,000 km long Australia-Pacific plate boundary extends from south of Macquarie Island to the southern Kermadec Island chain. It includes an oceanic transform (the Macquarie Ridge), two oppositely verging subduction zones (Puysegur and Hikurangi), and a transpressive continental transform, the Alpine Fault through South Island, New Zealand. Since 1900, there have been 15 M7.5+ earthquakes recorded near New Zealand. Nine of these, and the four largest, occurred along or near the Macquarie Ridge, including the 1989 M8.2 event on the ridge itself, and the 2004 M8.1 event 200 km to the west of the plate boundary, reflecting intraplate deformation. The largest recorded earthquake in New Zealand itself was the 1931 M7.8 Hawke's Bay earthquake, which killed 256 people. The last M7.5+ earthquake along the Alpine Fault was 170 years ago; studies of the faults' strain accumulation suggest that similar events are likely to occur again.

Self-bending of optical waveguides in a dry photosensitive medium

NASA Astrophysics Data System (ADS)

Malallah, Ra'ed; Wan, Min; Muniraj, Inbarasan; Cassidy, Derek; Sheridan, John T.

2018-03-01

Optical waveguide trajectories formed in an AA/PVA a photopolymer material photosensitive at 532 nm are examined. The transmission of light by this materials is discussed. The bending and arching of the waveguides which occur are investigated. The prediction of our model are shown to agree with the observed of trajectories. The largest index changes taking place at any time during the exposure, i.e. during SWW formation are found at the positions where the largest light intensity is present. Typically, such as maxima exist close to the input face at the location of the Primary Eye or at the location of the Secondary Eyes deeper with in the material. All photosensitive materials have a maximum saturation value of refractive index change that it is possible to induce, which is also discussed.

Transition year labeling error characterization study. [Kansas, Minnesota, Montana, North Dakota, South Dakota, and Oklahoma

NASA Technical Reports Server (NTRS)

Clinton, N. J. (Principal Investigator)

1980-01-01

Labeling errors made in the large area crop inventory experiment transition year estimates by Earth Observation Division image analysts are identified and quantified. The analysis was made from a subset of blind sites in six U.S. Great Plains states (Oklahoma, Kansas, Montana, Minnesota, North and South Dakota). The image interpretation basically was well done, resulting in a total omission error rate of 24 percent and a commission error rate of 4 percent. The largest amount of error was caused by factors beyond the control of the analysts who were following the interpretation procedures. The odd signatures, the largest error cause group, occurred mostly in areas of moisture abnormality. Multicrop labeling was tabulated showing the distribution of labeling for all crops.

Common but different: The expanding realm of Cladosporium

PubMed Central

Bensch, K.; Groenewald, J.Z.; Braun, U.; Dijksterhuis, J.; de Jesús Yáñez-Morales, M.; Crous, P.W.

2015-01-01

The genus Cladosporium (Cladosporiaceae, Dothideomycetes), which represents one of the largest genera of dematiaceous hyphomycetes, has been intensively investigated during the past decade. In the process, three major species complexes (C. cladosporioides, C. herbarum and C. sphaerospermum) were resolved based on morphology and DNA phylogeny, and a monographic revision of the genus (s. lat.) published reflecting the current taxonomic status quo. In the present study a further 19 new species are described based on phylogenetic characters (nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, as well as partial actin and translation elongation factor 1-α gene sequences) and morphological differences. For a selection of the species with ornamented conidia, scanning electron microscopic photos were prepared to illustrate the different types of surface ornamentation. Surprisingly, during this study Cladosporium ramotenellum was found to be a quite common saprobic species, being widely distributed and occurring on various substrates. Therefore, an emended species description is provided. Furthermore, the host range and distribution data for several previously described species are also expanded. PMID:26955200

Percolation transition in dynamical traffic network with evolving critical bottlenecks.

PubMed

Li, Daqing; Fu, Bowen; Wang, Yunpeng; Lu, Guangquan; Berezin, Yehiel; Stanley, H Eugene; Havlin, Shlomo

2015-01-20

A critical phenomenon is an intrinsic feature of traffic dynamics, during which transition between isolated local flows and global flows occurs. However, very little attention has been given to the question of how the local flows in the roads are organized collectively into a global city flow. Here we characterize this organization process of traffic as "traffic percolation," where the giant cluster of local flows disintegrates when the second largest cluster reaches its maximum. We find in real-time data of city road traffic that global traffic is dynamically composed of clusters of local flows, which are connected by bottleneck links. This organization evolves during a day with different bottleneck links appearing in different hours, but similar in the same hours in different days. A small improvement of critical bottleneck roads is found to benefit significantly the global traffic, providing a method to improve city traffic with low cost. Our results may provide insights on the relation between traffic dynamics and percolation, which can be useful for efficient transportation, epidemic control, and emergency evacuation.

Some insights on grassland health assessment based on remote sensing.

PubMed

Xu, Dandan; Guo, Xulin

2015-01-29

Grassland ecosystem is one of the largest ecosystems, which naturally occurs on all continents excluding Antarctica and provides both ecological and economic functions. The deterioration of natural grassland has been attracting many grassland researchers to monitor the grassland condition and dynamics for decades. Remote sensing techniques, which are advanced in dealing with the scale constraints of ecological research and provide temporal information, become a powerful approach of grassland ecosystem monitoring. So far, grassland health monitoring studies have mostly focused on different areas, for example, productivity evaluation, classification, vegetation dynamics, livestock carrying capacity, grazing intensity, natural disaster detecting, fire, climate change, coverage assessment and soil erosion. However, the grassland ecosystem is a complex system which is formed by soil, vegetation, wildlife and atmosphere. Thus, it is time to consider the grassland ecosystem as an entity synthetically and establish an integrated grassland health monitoring system to combine different aspects of the complex grassland ecosystem. In this review, current grassland health monitoring methods, including rangeland health assessment, ecosystem health assessment and grassland monitoring by remote sensing from different aspects, are discussed along with the future directions of grassland health assessment.

Some Insights on Grassland Health Assessment Based on Remote Sensing

PubMed Central

Xu, Dandan; Guo, Xulin

2015-01-01

Grassland ecosystem is one of the largest ecosystems, which naturally occurs on all continents excluding Antarctica and provides both ecological and economic functions. The deterioration of natural grassland has been attracting many grassland researchers to monitor the grassland condition and dynamics for decades. Remote sensing techniques, which are advanced in dealing with the scale constraints of ecological research and provide temporal information, become a powerful approach of grassland ecosystem monitoring. So far, grassland health monitoring studies have mostly focused on different areas, for example, productivity evaluation, classification, vegetation dynamics, livestock carrying capacity, grazing intensity, natural disaster detecting, fire, climate change, coverage assessment and soil erosion. However, the grassland ecosystem is a complex system which is formed by soil, vegetation, wildlife and atmosphere. Thus, it is time to consider the grassland ecosystem as an entity synthetically and establish an integrated grassland health monitoring system to combine different aspects of the complex grassland ecosystem. In this review, current grassland health monitoring methods, including rangeland health assessment, ecosystem health assessment and grassland monitoring by remote sensing from different aspects, are discussed along with the future directions of grassland health assessment. PMID:25643060

Time compression of soil erosion by the effect of largest daily event. A regional analysis of USLE database.

NASA Astrophysics Data System (ADS)

Gonzalez-Hidalgo, J. C.; Batalla, R.; Cerda, A.; de Luis, M.

2009-04-01

When Thornes and Brunsden wrote in 1977 "How often one hears the researcher (and no less the undergraduate) complain that after weeks of observation "nothing happened" only to learn that, the day after his departure, a flood caused unprecedent erosion and channel changes!" (Thornes and Brunsden, 1977, p. 57), they focussed on two different problems in geomorphological research: the effects of extreme events and the temporal compression of geomorphological processes. The time compression is one of the main characteristic of erosion processes. It means that an important amount of the total soil eroded is produced in very short temporal intervals, i.e. few events mostly related to extreme events. From magnitude-frequency analysis we know that few events, not necessarily extreme by magnitude, produce high amount of geomorphological work. Last but not least, extreme isolated events are a classical issue in geomorphology by their specific effects, and they are receiving permanent attention, increased at present because of scenarios of global change. Notwithstanding, the time compression of geomorphological processes could be focused not only on the analysis of extreme events and the traditional magnitude-frequency approach, but on new complementary approach based on the effects of largest events. The classical approach define extreme event as a rare event (identified by its magnitude and quantified by some deviation from central value), while we define largest events by the rank, whatever their magnitude. In a previous research on time compression of soil erosion, using USLE soil erosion database (Gonzalez-Hidalgo et al., EGU 2007), we described a relationship between the total amount of daily erosive events recorded by plot and the percentage contribution to total soil erosion of n-largest aggregated daily events. Now we offer a further refined analysis comparing different agricultural regions in USA. To do that we have analyzed data from 594 erosion plots from USLE database with different record periods, and located in different climatic regions. Results indicate that there are no significant differences in the mean contribution of aggregated 5-largest daily erosion events between different agricultural divisions (i.e. different regional climate), and the differences detected can be attributed to specific site and plots conditions. Expected contribution of 5-largest daily event for 100 total daily events recorded is estimated around 40% of total soil erosion. We discuss the possible causes of such results and the applicability of them to the design of field research on soil erosion plots.

An Ecological Perspective of Latina/o College Student Ethnicity

ERIC Educational Resources Information Center

Geertz Gonzalez, Roger

2017-01-01

Although Latinos are the largest minority population in the United States and the largest minority population on American campuses, there is little research concerning Latino college student ethnic identity. This study incorporates an ecological model to examine the levels of influence of different settings and backgrounds of Latino college…

Disparities in epilepsy surgery in the United States of America.

PubMed

Sánchez Fernández, Iván; Stephen, Christopher; Loddenkemper, Tobias

2017-08-01

The aim is to describe the epidemiology of epilepsy surgery in children and adults in the United States. We performed a descriptive study of the National Inpatient Sample (NIS) for the year 2012 and the Kids' Inpatient Database (KID) for the period 2010-2012, the largest all-payer databases on inpatient data in the USA. These databases estimate 97% of all inpatient hospital discharges in the USA. In the KID, 12,899 (0.2%) of admission records had brain surgery and 600 of the 4900 (12.2%) admissions with focal refractory epilepsy underwent epilepsy surgery. Epilepsy surgery occurred in 60% of Whites, 7% of Blacks, 15% of Hispanics, and 10% of other races. In the NIS, 99,650 (0.3%) of admission records had brain surgery and 1170 of the 9775 (12%) admissions with focal refractory epilepsy underwent epilepsy surgery. Epilepsy surgery occurred in 69% of Whites, 7% of Blacks, 9% of Hispanics, and 8% of other races. In both the KID and the NIS, lower socioeconomic status was mildly underrepresented in epilepsy surgery. In both pediatric and adult admissions, there was an overrepresentation of Whites and underrepresentation of Blacks, which persisted after stratifying by socioeconomic status. Females were underrepresented in epilepsy surgery, but gender disparities were partially explained by differences in socioeconomic status. Epilepsy surgery is not equally distributed across races in the USA and these differences are not fully attributable to differences in socioeconomic status. Racial disparities in epilepsy surgery similarly affect children and adults.

Intercomparison and validation of continental water level products derived from satellite radar altimetry

NASA Astrophysics Data System (ADS)

Ričko, Martina; Birkett, Charon M.; Carton, James A.; Crétaux, Jean-François

2012-01-01

Satellite radar altimeter measurements of lake and reservoir water levels complement in situ observations by providing stage information for ungauged basins and by filling data gaps in existing gauge records. Such additional measurements assist both research and operational programs. However, for a particular lake or reservoir, altimetric products offered to end-users may differ due to choice of employed instrument, processing technique, and applied geophysical corrections. To explore these differences, particularly with their potential impact on climate-based research, an intercomparison of three web-based water-level products (produced by Laboratoire d'Etudes en Géophysique et Océanographie Spatiale, National Aeronautics and Space Administration/United States Department of Agriculture, and European Space Agency/De Montfort University) has been undertaken based on 18 lakes and reservoirs. The products are well correlated with each other (r=0.87 to 0.99) and where in situ data are available are quite well correlated with the gauge measurements (r=0.73 to 0.99). Despite variations in data processing, the poorest root-mean-square differences between any altimeter product and gauge data (˜0.20 to 1.41 m) occur for the narrow reservoirs and smaller lakes. The largest discrepancies between the altimeter products occur for the lakes that freeze (Lake Athabasca and Woods). The current altimeter products provide acceptable accuracy, long-term trends and seasonality for climate applications. We discuss the merits of each product system, but recommend further validations and the provision of ice-detection flags.

Dynamics of highly polydisperse colloidal suspensions as a model system for bacterial cytoplasm.

PubMed

Hwang, Jiye; Kim, Jeongmin; Sung, Bong June

2016-08-01

There are various kinds of macromolecules in bacterial cell cytoplasm. The size polydispersity of the macromolecules is so significant that the crystallization and the phase separation could be suppressed, thus stabilizing the liquid state of bacterial cytoplasm. On the other hand, recent experiments suggested that the macromolecules in bacterial cytoplasm should exhibit glassy dynamics, which should be also affected significantly by the size polydispersity of the macromolecules. In this work, we investigate the anomalous and slow dynamics of highly polydisperse colloidal suspensions, of which size distribution is chosen to mimic Escherichia coli cytoplasm. We find from our Langevin dynamics simulations that the diffusion coefficient (D_{tot}) and the displacement distribution functions (P(r,t)) averaged over all colloids of different sizes do not show anomalous and glassy dynamic behaviors until the system volume fraction ϕ is increased up to 0.82. This indicates that the intrinsic polydispersity of bacterial cytoplasm should suppress the glass transition and help maintain the liquid state of the cytoplasm. On the other hand, colloids of each kind show totally different dynamic behaviors depending on their size. The dynamics of colloids of different size becomes non-Gaussian at a different range of ϕ, which suggests that a multistep glass transition should occur. The largest colloids undergo the glass transition at ϕ=0.65, while the glass transition does not occur for smaller colloids in our simulations even at the highest value of ϕ. We also investigate the distribution (P(θ,t)) of the relative angles of displacement for macromolecules and find that macromolecules undergo directionally correlated motions in a sufficiently dense system.

Dynamics of highly polydisperse colloidal suspensions as a model system for bacterial cytoplasm

NASA Astrophysics Data System (ADS)

Hwang, Jiye; Kim, Jeongmin; Sung, Bong June

2016-08-01

There are various kinds of macromolecules in bacterial cell cytoplasm. The size polydispersity of the macromolecules is so significant that the crystallization and the phase separation could be suppressed, thus stabilizing the liquid state of bacterial cytoplasm. On the other hand, recent experiments suggested that the macromolecules in bacterial cytoplasm should exhibit glassy dynamics, which should be also affected significantly by the size polydispersity of the macromolecules. In this work, we investigate the anomalous and slow dynamics of highly polydisperse colloidal suspensions, of which size distribution is chosen to mimic Escherichia coli cytoplasm. We find from our Langevin dynamics simulations that the diffusion coefficient (Dtot) and the displacement distribution functions (P (r ,t ) ) averaged over all colloids of different sizes do not show anomalous and glassy dynamic behaviors until the system volume fraction ϕ is increased up to 0.82. This indicates that the intrinsic polydispersity of bacterial cytoplasm should suppress the glass transition and help maintain the liquid state of the cytoplasm. On the other hand, colloids of each kind show totally different dynamic behaviors depending on their size. The dynamics of colloids of different size becomes non-Gaussian at a different range of ϕ , which suggests that a multistep glass transition should occur. The largest colloids undergo the glass transition at ϕ =0.65 , while the glass transition does not occur for smaller colloids in our simulations even at the highest value of ϕ . We also investigate the distribution (P (θ ,t ) ) of the relative angles of displacement for macromolecules and find that macromolecules undergo directionally correlated motions in a sufficiently dense system.

Role of Plasticity at Different Sites across the Time Course of Cerebellar Motor Learning

PubMed Central

Lisberger, Stephen G.

2014-01-01

Learning comprises multiple components that probably involve cellular and synaptic plasticity at multiple sites. Different neural sites may play their largest roles at different times during behavioral learning. We have used motor learning in smooth pursuit eye movements of monkeys to determine how and when different components of learning occur in a known cerebellar circuit. The earliest learning occurs when one climbing-fiber response to a learning instruction causes simple-spike firing rate of Purkinje cells in the floccular complex of the cerebellum to be depressed transiently at the time of the instruction on the next trial. Trial-over-trial depression and the associated learning in eye movement are forgotten in <6 s, but facilitate long-term behavioral learning over a time scale of ∼5 min. During 100 repetitions of a learning instruction, simple-spike firing rate becomes progressively depressed in Purkinje cells that receive climbing-fiber inputs from the instruction. In Purkinje cells that prefer the opposite direction of pursuit and therefore do not receive climbing-fiber inputs related to the instruction, simple-spike responses undergo potentiation, but more weakly and more slowly. Analysis of the relationship between the learned changes in simple-spike firing and learning in eye velocity suggests an orderly progression of plasticity: first on Purkinje cells with complex-spike (CS) responses to the instruction, later on Purkinje cells with CS responses to the opposite direction of instruction, and last in sites outside the cerebellar cortex. Climbing-fiber inputs appear to play a fast and primary, but nonexclusive, role in pursuit learning. PMID:24849344

Gene expression of commensal Lactobacillus johnsonii strain NCC533 during in vitro growth and in the murine gut.

PubMed

Denou, Emmanuel; Berger, Bernard; Barretto, Caroline; Panoff, Jean-Michel; Arigoni, Fabrizio; Brüssow, Harald

2007-11-01

Work with pathogens like Vibrio cholerae has shown major differences between genes expressed in bacteria grown in vitro and in vivo. To explore this subject for commensals, we investigated the transcription of the Lactobacillus johnsonii NCC533 genome during in vitro and in vivo growth using the microarray technology. During broth growth, 537, 626, and 277 of the 1,756 tested genes were expressed during exponential phase, "adaptation" (early stationary phase), and stationary phase, respectively. One hundred one, 150, and 33 genes, respectively, were specifically transcribed in these three phases. To explore the in vivo transcription program, we fed L. johnsonii containing a resistance plasmid to antibiotic-treated mice. After a 2-day washout phase, we determined the viable-cell counts of lactobacilli that were in the lumina and associated with the mucosae of different gut segments. While the cell counts showed a rather uniform distribution along the gut, we observed marked differences with respect to the expression of the Lactobacillus genome. The largest number of transcribed genes was in the stomach (n = 786); the next-largest numbers occurred in the cecum (n = 391) and the jejunum (n = 296), while only 26 Lactobacillus genes were transcribed in the colon. In vitro and in vivo transcription programs overlapped only partially. One hundred ninety-one of the transcripts from the lactobacilli in the stomach were not detected during in vitro growth; 202 and 213 genes, respectively, were transcribed under all in vitro and in vivo conditions; but the core transcriptome for all growth conditions comprised only 103 genes. Forty-four percent of the NCC533 genes were not detectably transcribed under any of the investigated conditions. Nontranscribed genes were clustered on the genome and enriched in the variable-genome part. Our data revealed not only major differences between in vitro- and in vivo-expressed genes in a Lactobacillus gut commensal organism but also marked changes in the expression of genes along the digestive tract.

To Grid or Not to Grid… Precipitation Data and Hydrological Modeling in the Khangai Mountain Region of Mongolia

NASA Astrophysics Data System (ADS)

Venable, N. B. H.; Fassnacht, S. R.; Adyabadam, G.

2014-12-01

Precipitation data in semi-arid and mountainous regions is often spatially and temporally sparse, yet it is a key variable needed to drive hydrological models. Gridded precipitation datasets provide a spatially and temporally coherent alternative to the use of point-based station data, but in the case of Mongolia, may not be constructed from all data available from government data sources, or may only be available at coarse resolutions. To examine the uncertainty associated with the use of gridded and/or point precipitation data, monthly water balance models of three river basins across forest steppe (the Khoid Tamir River at Ikhtamir), steppe (the Baidrag River at Bayanburd), and desert steppe (the Tuin River at Bogd) ecozones in the Khangai Mountain Region of Mongolia were compared. The models were forced over a 10-year period from 2001-2010, with gridded temperature and precipitation data at a 0.5 x 0.5 degree resolution. These results were compared to modeling using an interpolated hybrid of the gridded data and additional point data recently gathered from government sources; and with point data from the nearest meteorological station to the streamflow gage of choice. Goodness-of-fit measures including the Nash-Sutcliff Efficiency statistic, the percent bias, and the RMSE-observations standard deviation ratio were used to assess model performance. The results were mixed with smaller differences between the two gridded products as compared to the differences between gridded products and station data. The largest differences in precipitation inputs and modeled runoff amounts occurred between the two gridded datasets and station data in the desert steppe (Tuin), and the smallest differences occurred in the forest steppe (Khoid Tamir) and steppe (Baidrag). Mean differences between water balance model results are generally smaller than mean differences in the initial input data over the period of record. Seasonally, larger differences in gridded versus station-based precipitation products and modeled outputs occur in summer in the desert-steppe, and in spring in the forest steppe. Choice of precipitation data source in terms of gridded or point-based data directly affects model outcomes with greater uncertainty noted on a seasonal basis across ecozones of the Khangai.

A Poisson method application to the assessment of the earthquake hazard in the North Anatolian Fault Zone, Turkey

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

Türker, Tuğba, E-mail: tturker@ktu.edu.tr; Bayrak, Yusuf, E-mail: ybayrak@agri.edu.tr

North Anatolian Fault (NAF) is one from the most important strike-slip fault zones in the world and located among regions in the highest seismic activity. The NAFZ observed very large earthquakes from the past to present. The aim of this study; the important parameters of Gutenberg-Richter relationship (a and b values) estimated and this parameters taking into account, earthquakes were examined in the between years 1900-2015 for 10 different seismic source regions in the NAFZ. After that estimated occurrence probabilities and return periods of occurring earthquakes in fault zone in the next years, and is being assessed with Poisson methodmore » the earthquake hazard of the NAFZ. The Region 2 were observed the largest earthquakes for the only historical period and hasn’t been observed large earthquake for the instrumental period in this region. Two historical earthquakes (1766, M{sub S}=7.3 and 1897, M{sub S}=7.0) are included for Region 2 (Marmara Region) where a large earthquake is expected in the next years. The 10 different seismic source regions are determined the relationships between the cumulative number-magnitude which estimated a and b parameters with the equation of LogN=a-bM in the Gutenberg-Richter. A homogenous earthquake catalog for M{sub S} magnitude which is equal or larger than 4.0 is used for the time period between 1900 and 2015. The database of catalog used in the study has been created from International Seismological Center (ISC) and Boğazici University Kandilli observation and earthquake research institute (KOERI). The earthquake data were obtained until from 1900 to 1974 from KOERI and ISC until from 1974 to 2015 from KOERI. The probabilities of the earthquake occurring are estimated for the next 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 years in the 10 different seismic source regions. The highest earthquake occur probabilities in 10 different seismic source regions in the next years estimated that the region Tokat-Erzincan (Region 9) %99 with an earthquake occur probability for magnitude 6.5 which the return period 24.7 year, %92 with an earthquake occur probability for magnitude 7 which the return period 39.1 year, %80 with an earthquake occur probability for magnitude 7.5 which the return period 62.1 year, %64 with an earthquake occur probability for magnitude 8 which the return period 98.5 year. For the Marmara Region (Region 2) in the next 100 year estimated that %89 with an earthquake occur probability for magnitude 6 which the return period 44.9 year, %45 with an earthquake occur probability for magnitude 6.5 which the return period 87 year, %45 with an earthquake occur probability for magnitude 7 which the return period 168.6 year.« less

Effect of vibration amplitude on vapor cavitation in journal bearings

NASA Astrophysics Data System (ADS)

Brewe, D. E.; Jacobson, B. O.

Computational movies were used to analyze the formation and collapse of vapor cavitation bubbles in a submerged journal bearing. The effect of vibration amplitude on vapor cavitation was studied for a journal undergoing circular whirl. The boundary conditions were implemented using Elrod's algorithm, which conserves mass flow through the cavitation bubble as well as through the oil-film region of the bearing. The vibration amplitudes for the different cases studied resulted in maximum eccentricity ratios ranging from 0.4 to 0.9. The minimum eccentricity ratio reached in each case was 0.1. For the least vibration amplitude studied in which the eccentricity ratio varied between 0.1 and 0.4, no vapor cavitation occurred. The largest vibration amplitude (i.e., eccentricity ratios of 0.1 to 0.9) resulted in vapor cavitation present 76 percent of one complete orbit.

Exergy analysis of biomass organic Rankine cycle for power generation

NASA Astrophysics Data System (ADS)

Nur, T. B.; Sunoto

2018-02-01

The study examines proposed small biomass-fed Organic Rankine Cycle (ORC) power plant through exergy analysis. The system consists of combustion burner unit to utilize biomass as fuel, and organic Rankine cycle unit to produce power from the expander. The heat from combustion burner was transfered by thermal oil heater to evaporate ORC working fluid in the evaporator part. The effects of adding recuperator into exergy destruction were investigated. Furthermore, the results of the variations of system configurations with different operating parameters, such as the evaporating pressures, ambient temperatures, and expander pressures were analyzed. It was found that the largest exergy destruction occurs during processes are at combustion part, followed by evaporator, condenser, expander, and pump. The ORC system equipped with a recuperator unit exhibited good operational characteristics under wide range conditions compared to the one without recuperator.

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

Nelson, W.J.; DeMaris, P.J.; Bauer, R.A.

One of the largest deposits of low-sulfur coal in the Illinois Basin is in the so-called Hornsby District of Christian, Macoupin, and Montgomery Counties. An estimated resource of 1.17 billion tons of Herrin (No. 6) Coal, containing less than 2.5% sulfur, occurs here. Although the Hornsby deposit is thick, lies at moderate depth, and is close to market and labor supply, it has been barely touched by mining. The primary deterrent to mining this high-quality product has been fear of unstable roof conditions. Low-sulfur Hornsby coal contains about 1.5% less ash and 2% more moisture than does adjacent high-sulfur coal.more » The lower ash content probably reflects scarcity of pyrite. The reason for the difference in moisture content is unknown. High- and low-sulfur coal are nearly identical in heating value.« less

Oil, Water, and Wildlife: The Gulf of Mexico Disaster and Related Environmental Issues

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

Bickman, John W.

2010-08-04

The BP Macondo oil field spill in the Gulf of Mexico is the largest oil spill in U.S. history and has the potential to impact sea turtle and marine mammal populations, and others. This presentation will review the genotoxic effects of oil exposure in wildlife and discuss the potential for an oil spill to impact wildlife populations. Whereas some aspects of a spill are predictable, each spill is different because oils are highly variable, as are the environments in which they occur. The presentation will discuss what has been learned from previous spills, including the Exxon Valdez and the sovietmore » oil legacy in Azerbaijan, and the potential dangers of offshore oil development in the Arctic. Related Purdue University research efforts in oil-spill related engineering and science also will be highlighted.« less

Oil, Water, and Wildlife: The Gulf of Mexico Disaster and Related Environmental Issues

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

Bickman, John W.

The BP Macondo oil field spill in the Gulf of Mexico is the largest oil spill in U.S. history and has the potential to impact sea turtle and marine mammal populations, and others. This presentation will review the genotoxic effects of oil exposure in wildlife and discuss the potential for an oil spill to impact wildlife populations. Whereas some aspects of a spill are predictable, each spill is different because oils are highly variable, as are the environments in which they occur. The presentation will discuss what has been learned from previous spills, including the Exxon Valdez and the sovietmore » oil legacy in Azerbaijan, and the potential dangers of offshore oil development in the Arctic. Related Purdue University research efforts in oil-spill related engineering and science also will be highlighted.« less

Beyond the Census Tract: Patterns and Determinants of Racial Segregation at Multiple Geographic Scales*

PubMed Central

Lee, Barrett A.; Reardon, Sean F.; Firebaugh, Glenn; Farrell, Chad R.; Matthews, Stephen A.; O'Sullivan, David

2014-01-01

The census tract-based residential segregation literature rests on problematic assumptions about geographic scale and proximity. We pursue a new tract-free approach that combines explicitly spatial concepts and methods to examine racial segregation across egocentric local environments of varying size. Using 2000 census data for the 100 largest U.S. metropolitan areas, we compute a spatially modified version of the information theory index H to describe patterns of black-white, Hispanic-white, Asian-white, and multi-group segregation at different scales. The metropolitan structural characteristics that best distinguish micro-segregation from macro-segregation for each group combination are identified, and their effects are decomposed into portions due to racial variation occurring over short and long distances. A comparison of our results to those from tract-based analyses confirms the value of the new approach. PMID:25324575

Evaluation of social vulnerability to floods in Huaihe River basin: a methodology based on catastrophe theory

NASA Astrophysics Data System (ADS)

You, W. J.; Zhang, Y. L.

2015-08-01

Huaihe River is one of the seven largest rivers in China, in which floods occurred frequently. Disasters cause huge casualties and property losses to the basin, and also make it famous for high social vulnerability to floods. Based on the latest social-economic data, the index system of social vulnerability to floods was constructed, and Catastrophe theory method was used in the assessment process. The conclusion shows that social vulnerability as a basic attribute attached to urban environment, with significant changes from city to city across the Huaihe River basin. Different distribution characteristics are present in population, economy, flood prevention vulnerability. It is important to make further development of social vulnerability, which will play a positive role in disaster prevention, improvement of comprehensive ability to respond to disasters.

Oil, Water, and Wildlife: The Gulf of Mexico Disaster and Related Environmental Issues

ScienceCinema

Bickman, John W. [Purdue University, West Lafayette, Indiana, United States

2017-12-09

The BP Macondo oil field spill in the Gulf of Mexico is the largest oil spill in U.S. history and has the potential to impact sea turtle and marine mammal populations, and others. This presentation will review the genotoxic effects of oil exposure in wildlife and discuss the potential for an oil spill to impact wildlife populations. Whereas some aspects of a spill are predictable, each spill is different because oils are highly variable, as are the environments in which they occur. The presentation will discuss what has been learned from previous spills, including the Exxon Valdez and the soviet oil legacy in Azerbaijan, and the potential dangers of offshore oil development in the Arctic. Related Purdue University research efforts in oil-spill related engineering and science also will be highlighted.

Effect of vibration amplitude on vapor cavitation in journal bearings

NASA Technical Reports Server (NTRS)

Brewe, D. E.; Jacobson, B. O.

1986-01-01

Computational movies were used to analyze the formation and collapse of vapor cavitation bubbles in a submerged journal bearing. The effect of vibration amplitude on vapor cavitation was studied for a journal undergoing circular whirl. The boundary conditions were implemented using Elrod's algorithm, which conserves mass flow through the cavitation bubble as well as through the oil-film region of the bearing. The vibration amplitudes for the different cases studied resulted in maximum eccentricity ratios ranging from 0.4 to 0.9. The minimum eccentricity ratio reached in each case was 0.1. For the least vibration amplitude studied in which the eccentricity ratio varied between 0.1 and 0.4, no vapor cavitation occurred. The largest vibration amplitude (i.e., eccentricity ratios of 0.1 to 0.9) resulted in vapor cavitation present 76 percent of one complete orbit.

Incidence of first ever stroke during Hajj ceremony

PubMed Central

2013-01-01

Background The Hajj Ceremony, the largest annual gathering in the world, is the most important life event for any Muslim. This study was designed to evaluate the incidence of stroke among Iranian pilgrims during the Hajj ceremony. Methods We ascertained all cases of stroke occurring in a population of 92,974 Iranian pilgrims between November 27, 2007 and January 12, 2008. Incidence and risk factors of the first ever stroke in Hajj pilgrims were compared, within the same time frame, to those of the Mashhad residents, the second largest city in Iran. Data for the latter group were extracted from the Mashhad Stroke Incidence Study (MSIS) database. Results During the study period, 17 first-ever strokes occurred in the Hajj pilgrims and 40 first-ever stroke strokes occurred in the MSIS group. Overall, the adjusted incidence rate of first ever stroke in the Hajj cohort was lower than that of the MSIS population (9 vs. 16 per 100,000). For age- and gender-specific subgroups, the Hajj stroke crude rates were in general similar to or lower than the general population of Mashhad, Iran, with the exception of women aged 35 to 44 years and aged >75 years who were at greater risk of having first-ever stroke than the non-pilgrims of the same age. Conclusion The first ever stroke rate among Iranian Hajj pilgrims was lower than that of the general population in Mashhad, Iran, except for females 35–44 or more than 75 years old. The number of events occurring during the Hajj suggests that Islamic countries should consider designing preventive and screening programs for pilgrims. PMID:24308305

Variation in species-level plant functional traits over wetland indicator status categories

USGS Publications Warehouse

McCoy-Sulentic, Miles E.; Kolb, Thomas E.; Merritt, David M.; Palmquist, Emily C.; Ralston, Barbara E.; Sarr, Daniel A.

2017-01-01

Wetland indicator status (WIS) describes the habitat affinity of plant species and is used in wetland delineations and resource inventories. Understanding how species-level functional traits vary across WIS categories may improve designations, elucidate mechanisms of adaptation, and explain habitat optima and niche. We investigated differences in species-level traits of riparian flora across WIS categories, extending their application to indicate hydrologic habitat. We measured or compiled data on specific leaf area (SLA), stem specific gravity (SSG), seed mass, and mature height of 110 plant species that occur along the Colorado River in Grand Canyon, Arizona. Additionally, we measured leaf δ13C, δ15N, % carbon, % nitrogen, and C/N ratio of 56 species with C3 photosynthesis. We asked the following: (i) How do species-level traits vary over WIS categories? (ii) Does the pattern differ between herbaceous and woody species? (iii) How well do multivariate traits define WIS categories? (iv) Which traits are correlated? The largest trait differences among WIS categories for herbaceous species occurred for SSG, seed mass, % leaf carbon and height, and for woody species occurred for height, SSG, and δ13C. SSG increased and height decreased with habitat aridity for both woody and herbaceous species. The δ13C and hence water use efficiency of woody species increased with habitat aridity. Water use efficiency of herbaceous species increased with habitat aridity via greater occurrence of C4 grasses. Multivariate trait assemblages differed among WIS categories. Over all species, SLA was correlated with height, δ13C, % leaf N, and C/N; height was correlated with SSG and % leaf C; SSG was correlated with % leaf C. Adaptations of both herbaceous and woody riparian species to wet, frequently inundated habitats include low-density stem tissue. Adaptations to drier habitats in the riparian zone include short, high-density cavitation-resistant stem tissue, and high water use efficiency. The results enhance understanding about using traits to describe plant habitat in riparian systems.

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

Rowland, Joel C; Manga, Michael

The origin of increased stream flow and spring discharge following earthquakes have been the subject of controversy, in large part because there are many models to explain observations and few measurements suitable for distinguishing between hypotheses. On October 30, 2007 a magnitude 5.5 earthquake occurred near the Alum Rock springs, California, USA. Within a day we documented a several-fold increase in discharge. Over the following year, we have monitored a gradual return towards pre-earthquake properties, but for the largest springs there appears to be a permanent increase in the steady discharge at all the springs. The Alum Rock springs dischargemore » waters that represent a mixture between modern ('shallow') meteoric water and old ('deep') connate waters expelled by regional transpression. After the earthquake, the increased discharge at the largest springs was accompanied by a small decrease in the fraction of connate water in the spring discharge. Combined with the rapid response, this implies that the increased discharge has a shallow origin. Increased discharge at these springs occurs for earthquakes that cause static volumetric expansion and those that cause contraction, supporting models in which dynamic strains are responsible for the subsurface changes that cause flow to increase. We show that models in which the permeability of the fracture system feeding the springs increases after the earthquake are in general consistent with the changes in discharge. The response of these springs to another earthquake will provide critical constraints on the changes that occur in the subsurface.« less

Impacts of a massive release of methane and hydrogen sulfide on oxygen and ozone during the late Permian mass extinction

NASA Astrophysics Data System (ADS)

Kaiho, Kunio; Koga, Seizi

2013-08-01

The largest mass extinction of animals and plants in both the ocean and on land occurred in the late Permian (252 Ma), largely coinciding with the largest flood basalt volcanism event in Siberia and an oceanic anoxic/euxinic event. We investigated the impacts of a massive release of methane (CH4) from the Siberian igneous province and the ocean and/or hydrogen sulfide (H2S) from the euxinic ocean on oxygen and ozone using photochemical model calculations. Our calculations indicated that an approximate of 14% decrease in atmospheric O2 levels would have occurred in the case of a large combined CH4 and H2S flux to the atmosphere, whereas an approximate of 8 to 10% decrease would have occurred from the CH4 flux and oxidation of all H2S in the ocean. The slight decrease in atmospheric O2 levels may have contributed to the extinction event. We demonstrate for the first time that a massive release of CH4 from the Siberian igneous province and a coincident massive release of CH4 and H2S did not cause ozone collapse. A collapse of stratospheric ozone leading to an increase in UV is not supported by the maximum model input levels for CH4 and H2S. These conclusions on O2 and O3 are correspondent to every H2S release percentages from the ocean to the atmosphere.

Range contraction in large pelagic predators

PubMed Central

Worm, Boris; Tittensor, Derek P.

2011-01-01

Large reductions in the abundance of exploited land predators have led to significant range contractions for those species. This pattern can be formalized as the range–abundance relationship, a general macroecological pattern that has important implications for the conservation of threatened species. Here we ask whether similar responses may have occurred in highly mobile pelagic predators, specifically 13 species of tuna and billfish. We analyzed two multidecadal global data sets on the spatial distribution of catches and fishing effort targeting these species and compared these with available abundance time series from stock assessments. We calculated the effort needed to reliably detect the presence of a species and then computed observed range sizes in each decade from 1960 to 2000. Results suggest significant range contractions in 9 of the 13 species considered here (between 2% and 46% loss of observed range) and significant range expansions in two species (11–29% increase). Species that have undergone the largest declines in abundance and are of particular conservation concern tended to show the largest range contractions. These include all three species of bluefin tuna and several marlin species. In contrast, skipjack tuna, which may have increased its abundance in the Pacific, has also expanded its range size. These results mirror patterns described for many land predators, despite considerable differences in habitat, mobility, and dispersal, and imply ecological extirpation of heavily exploited species across parts of their range. PMID:21693644

Occupational class differences in diagnostic-specific sickness absence: a register-based study in the Finnish population, 2005-2014.

PubMed

Pekkala, Johanna; Blomgren, Jenni; Pietiläinen, Olli; Lahelma, Eero; Rahkonen, Ossi

2017-08-22

Musculoskeletal diseases and mental disorders are major causes of long-term sickness absence in Western countries. Although sickness absence is generally more common in lower occupational classes, little is known about class differences in diagnostic-specific absence over time. Focusing on Finland during 2005-2014, we therefore set out to examine the magnitude of and changes in absolute and relative occupational class differences in long-term sickness absence due to major diagnostic causes. A 70-per-cent random sample of Finns aged 25-64 linked to register data on medically certified sickness absence (of over 10 working days) in 2005-2014 was retrieved from the Social Insurance Institution of Finland. Information on occupational class was obtained from Statistics Finland and linked to the data. The study focused on female (n = 658,148-694,142) and male (n = 604,715-642,922) upper and lower non-manual employees and manual workers. The age-standardised prevalence, the Slope Index of Inequality (SII) and the Relative Index of Inequality (RII) were calculated for each study year to facilitate examination of the class differences. The prevalence of each diagnostic cause of sickness absence declined during the study period, the most common causes being musculoskeletal diseases, mental disorders and injuries. The prevalence of other causes under scrutiny was less than 1 % annually. By far the largest absolute and relative differences were in musculoskeletal diseases among both women and men. Moreover, the absolute differences in both genders (p < 0.0001) and the relative differences in men (p < 0.0001) narrowed over time as the prevalence declined most among manual workers. Both genders showed modest and stable occupational class differences in mental disorders. In the case of injuries, no major changes occurred in absolute differences but relative differences narrowed over time in men (p < 0.0001) due to a strong decline in prevalence among manual workers. Class differences in the other studied diagnostic causes under scrutiny appeared negligible. By far the largest occupational class differences in long-term sickness absence concerned musculoskeletal diseases, followed by injuries. The results highlight potential targets for preventive measures aimed at reducing sickness absence and narrowing class differences in the future.

Differences between true mean daily, monthly and annual air temperatures and air temperatures calculated with three equations: a case study from three Croatian stations

NASA Astrophysics Data System (ADS)

Bonacci, Ognjen; Željković, Ivana; Trogrlić, Robert Šakić; Milković, Janja

2013-10-01

Differences between true mean daily, monthly and annual air temperatures T0 [Eq. (1)] and temperatures calculated with three different equations [(2), (3) and (4)] (commonly used in climatological practice) were investigated at three main meteorological Croatian stations from 1 January 1999 to 31 December 2011. The stations are situated in the following three climatically distinct areas: (1) Zagreb-Grič (mild continental climate), (2) Zavižan (cold mountain climate), and (3) Dubrovnik (hot Mediterranean climate). T1 [Eq. (2)] and T3 [Eq. (4)] mean temperatures are defined by the algorithms based on the weighted means of temperatures measured at irregularly spaced, yet fixed hours. T2 [Eq. (3)] is the mean temperature defined as the average of daily maximum and minimum temperature. The equation as well as the time of observations used introduces a bias into mean temperatures. The largest differences occur for mean daily temperatures. The calculated daily difference value from all three equations and all analysed stations varies from -3.73 °C to +3.56 °C, from -1.39 °C to +0.79 °C for monthly differences and from -0.76 °C to +0.30 °C for annual differences.

A synthesis of methane emissions from 71 northern, temperate, and subtropical wetlands.

PubMed

Turetsky, Merritt R; Kotowska, Agnieszka; Bubier, Jill; Dise, Nancy B; Crill, Patrick; Hornibrook, Ed R C; Minkkinen, Kari; Moore, Tim R; Myers-Smith, Isla H; Nykänen, Hannu; Olefeldt, David; Rinne, Janne; Saarnio, Sanna; Shurpali, Narasinha; Tuittila, Eeva-Stiina; Waddington, J Michael; White, Jeffrey R; Wickland, Kimberly P; Wilmking, Martin

2014-07-01

Wetlands are the largest natural source of atmospheric methane. Here, we assess controls on methane flux using a database of approximately 19 000 instantaneous measurements from 71 wetland sites located across subtropical, temperate, and northern high latitude regions. Our analyses confirm general controls on wetland methane emissions from soil temperature, water table, and vegetation, but also show that these relationships are modified depending on wetland type (bog, fen, or swamp), region (subarctic to temperate), and disturbance. Fen methane flux was more sensitive to vegetation and less sensitive to temperature than bog or swamp fluxes. The optimal water table for methane flux was consistently below the peat surface in bogs, close to the peat surface in poor fens, and above the peat surface in rich fens. However, the largest flux in bogs occurred when dry 30-day averaged antecedent conditions were followed by wet conditions, while in fens and swamps, the largest flux occurred when both 30-day averaged antecedent and current conditions were wet. Drained wetlands exhibited distinct characteristics, e.g. the absence of large flux following wet and warm conditions, suggesting that the same functional relationships between methane flux and environmental conditions cannot be used across pristine and disturbed wetlands. Together, our results suggest that water table and temperature are dominant controls on methane flux in pristine bogs and swamps, while other processes, such as vascular transport in pristine fens, have the potential to partially override the effect of these controls in other wetland types. Because wetland types vary in methane emissions and have distinct controls, these ecosystems need to be considered separately to yield reliable estimates of global wetland methane release. © 2014 John Wiley & Sons Ltd.

A synthesis of methane emissions from 71 northern, temperate, and subtropical wetlands

USGS Publications Warehouse

Turetsky, Merritt R.; Kotowska, Agnieszka; Bubier, Jill; Dise, Nancy B.; Crill, Patrick; Hornibrook, Ed R.C.; Minkkinen, Kari; Moore, Tim R.; Myers-Smith, Isla H.; Nykanen, Hannu; Olefeldt, David; Rinne, Janne; Saarnio, Sanna; Shurpali, Narasinha; Tuittila, Eeva-Stiina; Waddington, J. Michael; White, Jeffrey R.; Wickland, Kimberly P.; Wilmking, Martin

2014-01-01

Wetlands are the largest natural source of atmospheric methane. Here, we assess controls on methane flux using a database of approximately 19 000 instantaneous measurements from 71 wetland sites located across subtropical, temperate, and northern high latitude regions. Our analyses confirm general controls on wetland methane emissions from soil temperature, water table, and vegetation, but also show that these relationships are modified depending on wetland type (bog, fen, or swamp), region (subarctic to temperate), and disturbance. Fen methane flux was more sensitive to vegetation and less sensitive to temperature than bog or swamp fluxes. The optimal water table for methane flux was consistently below the peat surface in bogs, close to the peat surface in poor fens, and above the peat surface in rich fens. However, the largest flux in bogs occurred when dry 30-day averaged antecedent conditions were followed by wet conditions, while in fens and swamps, the largest flux occurred when both 30-day averaged antecedent and current conditions were wet. Drained wetlands exhibited distinct characteristics, e.g. the absence of large flux following wet and warm conditions, suggesting that the same functional relationships between methane flux and environmental conditions cannot be used across pristine and disturbed wetlands. Together, our results suggest that water table and temperature are dominant controls on methane flux in pristine bogs and swamps, while other processes, such as vascular transport in pristine fens, have the potential to partially override the effect of these controls in other wetland types. Because wetland types vary in methane emissions and have distinct controls, these ecosystems need to be considered separately to yield reliable estimates of global wetland methane release.

The 2016 Mihoub (north-central Algeria) earthquake sequence: Seismological and tectonic aspects

NASA Astrophysics Data System (ADS)

Khelif, M. F.; Yelles-Chaouche, A.; Benaissa, Z.; Semmane, F.; Beldjoudi, H.; Haned, A.; Issaadi, A.; Chami, A.; Chimouni, R.; Harbi, A.; Maouche, S.; Dabbouz, G.; Aidi, C.; Kherroubi, A.

2018-06-01

On 28 May 2016 at 23:54 (UTC), an Mw5.4 earthquake occurred in Mihoub village, Algeria, 60 km southeast of Algiers. This earthquake was the largest event in a sequence recorded from 10 April to 15 July 2016. In addition to the permanent national network, a temporary network was installed in the epicentral region after this shock. Recorded event locations allow us to give a general overview of the sequence and reveal the existence of two main fault segments. The first segment, on which the first event in the sequence was located, is near-vertical and trends E-W. The second fault plane, on which the largest event of the sequence was located, dips to the southeast and strikes NE-SW. A total of 46 well-constrained focal mechanisms were calculated. The events located on the E-W-striking fault segment show mainly right-lateral strike-slip (strike N70°E, dip 77° to the SSE, rake 150°). The events located on the NE-SW-striking segment show mainly reverse faulting (strike N60°E, dip 70° to the SE, rake 130°). We calculated the static stress change caused by the first event (Md4.9) of the sequence; the result shows that the fault plane of the largest event in the sequence (Mw5.4) and most of the aftershocks occurred within an area of increased Coulomb stress. Moreover, using the focal mechanisms calculated in this work, we estimated the orientations of the main axes of the local stress tensor ellipsoid. The results confirm previous findings that the general stress field in this area shows orientations aligned NNW-SSE to NW-SE. The 2016 Mihoub earthquake sequence study thus improves our understanding of seismic hazard in north-central Algeria.

Rhodolith Beds Are Major CaCO3 Bio-Factories in the Tropical South West Atlantic

PubMed Central

Amado-Filho, Gilberto M.; Moura, Rodrigo L.; Bastos, Alex C.; Salgado, Leonardo T.; Sumida, Paulo Y.; Guth, Arthur Z.; Francini-Filho, Ronaldo B.; Pereira-Filho, Guilherme H.; Abrantes, Douglas P.; Brasileiro, Poliana S.; Bahia, Ricardo G.; Leal, Rachel N.; Kaufman, Les; Kleypas, Joanie A.; Farina, Marcos; Thompson, Fabiano L.

2012-01-01

Rhodoliths are nodules of non-geniculate coralline algae that occur in shallow waters (<150 m depth) subjected to episodic disturbance. Rhodolith beds stand with kelp beds, seagrass meadows, and coralline algal reefs as one of the world's four largest macrophyte-dominated benthic communities. Geographic distribution of rhodolith beds is discontinuous, with large concentrations off Japan, Australia and the Gulf of California, as well as in the Mediterranean, North Atlantic, eastern Caribbean and Brazil. Although there are major gaps in terms of seabed habitat mapping, the largest rhodolith beds are purported to occur off Brazil, where these communities are recorded across a wide latitudinal range (2°N - 27°S). To quantify their extent, we carried out an inter-reefal seabed habitat survey on the Abrolhos Shelf (16°50′ - 19°45′S) off eastern Brazil, and confirmed the most expansive and contiguous rhodolith bed in the world, covering about 20,900 km2. Distribution, extent, composition and structure of this bed were assessed with side scan sonar, remotely operated vehicles, and SCUBA. The mean rate of CaCO3 production was estimated from in situ growth assays at 1.07 kg m−2 yr−1, with a total production rate of 0.025 Gt yr−1, comparable to those of the world's largest biogenic CaCO3 deposits. These gigantic rhodolith beds, of areal extent equivalent to the Great Barrier Reef, Australia, are a critical, yet poorly understood component of the tropical South Atlantic Ocean. Based on the relatively high vulnerability of coralline algae to ocean acidification, these beds are likely to experience a profound restructuring in the coming decades. PMID:22536356

Toward a consistent model for strain accrual and release for the New Madrid Seismic Zone, central United States

USGS Publications Warehouse

Hough, S.E.; Page, M.

2011-01-01

At the heart of the conundrum of seismogenesis in the New Madrid Seismic Zone is the apparently substantial discrepancy between low strain rate and high recent seismic moment release. In this study we revisit the magnitudes of the four principal 1811–1812 earthquakes using intensity values determined from individual assessments from four experts. Using these values and the grid search method of Bakun and Wentworth (1997), we estimate magnitudes around 7.0 for all four events, values that are significantly lower than previously published magnitude estimates based on macroseismic intensities. We further show that the strain rate predicted from postglacial rebound is sufficient to produce a sequence with the moment release of one Mmax6.8 every 500 years, a rate that is much lower than previous estimates of late Holocene moment release. However, Mw6.8 is at the low end of the uncertainty range inferred from analysis of intensities for the largest 1811–1812 event. We show that Mw6.8 is also a reasonable value for the largest main shock given a plausible rupture scenario. One can also construct a range of consistent models that permit a somewhat higher Mmax, with a longer average recurrence rate. It is thus possible to reconcile predicted strain and seismic moment release rates with alternative models: one in which 1811–1812 sequences occur every 500 years, with the largest events being Mmax∼6.8, or one in which sequences occur, on average, less frequently, with Mmax of ∼7.0. Both models predict that the late Holocene rate of activity will continue for the next few to 10 thousand years.

Copper Oxide Precipitates in NBS Standard Reference Material 482

PubMed Central

Windsor, Eric S.; Carlton, Robert A.; Gillen, Greg; Wight, Scott A.; Bright, David S.

2002-01-01

Copper oxide has been detected in the copper containing alloys of NBS Standard Reference Material (SRM) 482. This occurrence is significant because it represents heterogeneity within a standard reference material that was certified to be homogeneous on a micrometer scale. Oxide occurs as elliptically to spherically shaped precipitates whose size differs with alloy composition. The largest precipitates occur in the Au20-Cu80 alloy and range in size from submicrometer up to 2 μm in diameter. Precipitates are observed using light microscopy, electron microscopy, and secondary ion mass spectrometry (SIMS). SIMS has demonstrated that the precipitates are present within all the SRM 482 wires that contain copper. Only the pure gold wire is precipitate free. Initial results from the analysis of the Au20-Cu80 alloy indicate that the percentage of precipitates is less than 1 % by area. Electron probe microanalysis (EPMA) of large (2 μm) precipitates in this same alloy indicates that precipitates are detectable by EPMA and that their composition differs significantly from the certified alloy composition. The small size and low percentage of these oxide precipitates minimizes the impact that they have upon the intended use of this standard for electron probe microanalysis. Heterogeneity caused by these oxide precipitates may however preclude the use of this standard for automated EPMA analyses and other microanalysis techniques. PMID:27446759

Hereditary spastic paraplegia in Greece: characterisation of a previously unexplored population using next-generation sequencing

PubMed Central

Lynch, David S; Koutsis, Georgios; Tucci, Arianna; Panas, Marios; Baklou, Markella; Breza, Marianthi; Karadima, Georgia; Houlden, Henry

2016-01-01

Hereditary Spastic Paraplegia (HSP) is a syndrome characterised by lower limb spasticity, occurring alone or in association with other neurological manifestations, such as cognitive impairment, seizures, ataxia or neuropathy. HSP occurs worldwide, with different populations having different frequencies of causative genes. The Greek population has not yet been characterised. The purpose of this study was to describe the clinical presentation and molecular epidemiology of the largest cohort of HSP in Greece, comprising 54 patients from 40 families. We used a targeted next-generation sequencing (NGS) approach to genetically assess a proband from each family. We made a genetic diagnosis in >50% of cases and identified 11 novel variants. Variants in SPAST and KIF5A were the most common causes of autosomal dominant HSP, whereas SPG11 and CYP7B1 were the most common cause of autosomal recessive HSP. We identified a novel variant in SPG11, which led to disease with later onset and may be unique to the Greek population and report the first nonsense mutation in KIF5A. Interestingly, the frequency of HSP mutations in the Greek population, which is relatively isolated, was very similar to other European populations. We confirm that NGS approaches are an efficient diagnostic tool and should be employed early in the assessment of HSP patients. PMID:26374131

Continental-scale consequences of tree die-offs in North America: identifying where forest loss matters most

NASA Astrophysics Data System (ADS)

Swann, Abigail L. S.; Laguë, Marysa M.; Garcia, Elizabeth S.; Field, Jason P.; Breshears, David D.; Moore, David J. P.; Saleska, Scott R.; Stark, Scott C.; Villegas, Juan Camilo; Law, Darin J.; Minor, David M.

2018-05-01

Regional-scale tree die-off events driven by drought and warming and associated pests and pathogens have occurred recently on all forested continents and are projected to increase in frequency and extent with future warming. Within areas where tree mortality has occurred, ecological, hydrological and meteorological consequences are increasingly being documented. However, the potential for tree die-off to impact vegetation processes and related carbon dynamics in areas remote to where die-off occurs has rarely been systematically evaluated, particularly for multiple distinct regions within a given continent. Such remote impacts can occur when climate effects of local vegetation change are propagated by atmospheric circulation—the phenomena of ‘ecoclimate teleconnections’. We simulated tree die-off events in the 13 most densely forested US regions (selected from the 20 US National Ecological Observatory Network [NEON] domains) and found that tree die-off even for smaller regions has potential to affect climate and hence Gross Primary Productivity (GPP) in disparate regions (NEON domains), either positively or negatively. Some regions exhibited strong teleconnections to several others, and some regions were relatively sensitive to tree loss regardless of what other region the tree loss occurred in. For the US as a whole, loss of trees in the Pacific Southwest—an area undergoing rapid tree die-off—had the largest negative impact on remote US GPP whereas loss of trees in the Mid-Atlantic had the largest positive impact. This research lays a foundation for hypotheses that identify how the effects of tree die-off (or other types of tree loss such as deforestation) can ricochet across regions by revealing hot-spots of forcing and response. Such modes of connectivity have direct applicability for improving models of climate change impacts and for developing more informed and coordinated carbon accounting across regions.

The ShakeOut earthquake scenario: Verification of three simulation sets

USGS Publications Warehouse

Bielak, J.; Graves, R.W.; Olsen, K.B.; Taborda, R.; Ramirez-Guzman, L.; Day, S.M.; Ely, G.P.; Roten, D.; Jordan, T.H.; Maechling, P.J.; Urbanic, J.; Cui, Y.; Juve, G.

2010-01-01

This paper presents a verification of three simulations of the ShakeOut scenario, an Mw 7.8 earthquake on a portion of the San Andreas fault in southern California, conducted by three different groups at the Southern California Earthquake Center using the SCEC Community Velocity Model for this region. We conducted two simulations using the finite difference method, and one by the finite element method, and performed qualitative and quantitative comparisons between the corresponding results. The results are in good agreement with each other; only small differences occur both in amplitude and phase between the various synthetics at ten observation points located near and away from the fault-as far as 150 km away from the fault. Using an available goodness-of-fit criterion all the comparisons scored above 8, with most above 9.2. This score would be regarded as excellent if the measurements were between recorded and synthetic seismograms. We also report results of comparisons based on time-frequency misfit criteria. Results from these two criteria can be used for calibrating the two methods for comparing seismograms. In those cases in which noticeable discrepancies occurred between the seismograms generated by the three groups, we found that they were the product of inherent characteristics of the various numerical methods used and their implementations. In particular, we found that the major source of discrepancy lies in the difference between mesh and grid representations of the same material model. Overall, however, even the largest differences in the synthetic seismograms are small. Thus, given the complexity of the simulations used in this verification, it appears that the three schemes are consistent, reliable and sufficiently accurate and robust for use in future large-scale simulations. ?? 2009 The Authors Journal compilation ?? 2009 RAS.

Deep crustal earthquakes associated with continental rifts

NASA Astrophysics Data System (ADS)

Doser, Diane I.; Yarwood, Dennis R.

1994-01-01

Deep (> 20 km) crustal earthquakes have occurred within or along the margins of at least four continental rift zones. The largest of these deep crustal earthquakes ( M ⩾ 5.0) have strike-slip or oblique-slip mechanisms with T-axes oriented similarly to those associated with shallow normal faulting within the rift zones. The majority of deep crustal earthquakes occur along the rift margins in regions that have cooler, thicker crust. Several deep crustal events, however, occur in regions of high heat flow. These regions also appear to be regions of high strain, a factor that could account for the observed depths. We believe the deep crustal earthquakes represent either the relative motion of rift zones with respect to adjacent stable regions or the propagation of rifting into stable regions.

Coupling between the spinal cord and cervical vertebral column under tensile loading.

PubMed

Kroeker, Shannon G; Ching, Randal P

2013-02-22

Current neck injury criteria are based on structural failure of the spinal (vertebral) column without consideration of injury to the spinal cord. Since one of the primary functions of the vertebral column is to protect the cord, it stands to reason that a more refined measure of neck injury threshold would be the onset of spinal cord injury (SCI). This study investigated the relationship between axial strains in the cervical vertebral column and the spinal cord using an in vitro primate model (n=10) under continuous tensile loading. Mean failure loads occurred at 1951.5±396N with failure strains in the vertebral column of 16±5% at the level of failure. Average tensile strains in the spinal cord at failure were 11±5% resulting in a mean coupling ratio of 0.54±0.17 between C1 and C7. The level of peak strain measured in the spinal cord did not always occur at the location of vertebral column failure. Spinal cord strains were less than spine strains and coupling ratios were not significantly different along the length of the spine. The largest coupling ratio was measured in the atlanto-occipital joint whereas the smallest coupling ratio occurred at the adjacent C1-C2 joint. Copyright © 2012 Elsevier Ltd. All rights reserved.

Zero-lag synchronization in coupled time-delayed piecewise linear electronic circuits

NASA Astrophysics Data System (ADS)

Suresh, R.; Srinivasan, K.; Senthilkumar, D. V.; Raja Mohamed, I.; Murali, K.; Lakshmanan, M.; Kurths, J.

2013-07-01

We investigate and report an experimental confirmation of zero-lag synchronization (ZLS) in a system of three coupled time-delayed piecewise linear electronic circuits via dynamical relaying with different coupling configurations, namely mutual and subsystem coupling configurations. We have observed that when there is a feedback between the central unit (relay unit) and at least one of the outer units, ZLS occurs in the two outer units whereas the central and outer units exhibit inverse phase synchronization (IPS). We find that in the case of mutual coupling configuration ZLS occurs both in periodic and hyperchaotic regimes, while in the subsystem coupling configuration it occurs only in the hyperchaotic regime. Snapshots of the time evolution of outer circuits as observed from the oscilloscope confirm the occurrence of ZLS experimentally. The quality of ZLS is numerically verified by correlation coefficient and similarity function measures. Further, the transition to ZLS is verified from the changes in the largest Lyapunov exponents and the correlation coefficient as a function of the coupling strength. IPS is experimentally confirmed using time series plots and also can be visualized using the concept of localized sets which are also corroborated by numerical simulations. In addition, we have calculated the correlation of probability of recurrence to quantify the phase coherence. We have also analytically derived a sufficient condition for the stability of ZLS using the Krasovskii-Lyapunov theory.

The Pawnee earthquake as a result of the interplay among injection, faults and foreshocks.

PubMed

Chen, Xiaowei; Nakata, Nori; Pennington, Colin; Haffener, Jackson; Chang, Jefferson C; He, Xiaohui; Zhan, Zhongwen; Ni, Sidao; Walter, Jacob I

2017-07-10

The Pawnee M5.8 earthquake is the largest event in Oklahoma instrument recorded history. It occurred near the edge of active seismic zones, similar to other M5+ earthquakes since 2011. It ruptured a previously unmapped fault and triggered aftershocks along a complex conjugate fault system. With a high-resolution earthquake catalog, we observe propagating foreshocks leading to the mainshock within 0.5 km distance, suggesting existence of precursory aseismic slip. At approximately 100 days before the mainshock, two M ≥ 3.5 earthquakes occurred along a mapped fault that is conjugate to the mainshock fault. At about 40 days before, two earthquakes clusters started, with one M3 earthquake occurred two days before the mainshock. The three M ≥ 3 foreshocks all produced positive Coulomb stress at the mainshock hypocenter. These foreshock activities within the conjugate fault system are near-instantaneously responding to variations in injection rates at 95% confidence. The short time delay between injection and seismicity differs from both the hypothetical expected time scale of diffusion process and the long time delay observed in this region prior to 2016, suggesting a possible role of elastic stress transfer and critical stress state of the fault. Our results suggest that the Pawnee earthquake is a result of interplay among injection, tectonic faults, and foreshocks.

Evaluating landfill aftercare strategies: A life cycle assessment approach.

PubMed

Turner, David A; Beaven, Richard P; Woodman, Nick D

2017-05-01

This study investigates the potential impacts caused by the loss of active environmental control measures during the aftercare period of landfill management. A combined mechanistic solute flow model and life cycle assessment (LCA) approach was used to evaluate the potential impacts of leachate emissions over a 10,000year time horizon. A continuum of control loss possibilities occurring at different times and for different durations were investigated for four different basic aftercare scenarios, including a typical aftercare scenario involving a low permeability cap and three accelerated aftercare scenarios involving higher initial infiltration rates. Assuming a 'best case' where control is never lost, the largest potential impacts resulted from the typical aftercare scenario. The maximum difference between potential impacts from the 'best case' and the 'worst case', where control fails at the earliest possible point and is never reinstated, was only a fourfold increase. This highlights potential deficiencies in standard life cycle impact assessment practice, which are discussed. Nevertheless, the results show how the influence of active control loss on the potential impacts of landfilling varies considerably depending on the aftercare strategy used and highlight the importance that leachate treatment efficiencies have upon impacts. Copyright © 2016 Elsevier Ltd. All rights reserved.

Lessons learned from comparing molecular dynamics engines on the SAMPL5 dataset.

PubMed

Shirts, Michael R; Klein, Christoph; Swails, Jason M; Yin, Jian; Gilson, Michael K; Mobley, David L; Case, David A; Zhong, Ellen D

2017-01-01

We describe our efforts to prepare common starting structures and models for the SAMPL5 blind prediction challenge. We generated the starting input files and single configuration potential energies for the host-guest in the SAMPL5 blind prediction challenge for the GROMACS, AMBER, LAMMPS, DESMOND and CHARMM molecular simulation programs. All conversions were fully automated from the originally prepared AMBER input files using a combination of the ParmEd and InterMol conversion programs. We find that the energy calculations for all molecular dynamics engines for this molecular set agree to better than 0.1 % relative absolute energy for all energy components, and in most cases an order of magnitude better, when reasonable choices are made for different cutoff parameters. However, there are some surprising sources of statistically significant differences. Most importantly, different choices of Coulomb's constant between programs are one of the largest sources of discrepancies in energies. We discuss the measures required to get good agreement in the energies for equivalent starting configurations between the simulation programs, and the energy differences that occur when simulations are run with program-specific default simulation parameter values. Finally, we discuss what was required to automate this conversion and comparison.

Lessons learned from comparing molecular dynamics engines on the SAMPL5 dataset

PubMed Central

Shirts, Michael R.; Klein, Christoph; Swails, Jason M.; Yin, Jian; Gilson, Michael K.; Mobley, David L.; Case, David A.; Zhong, Ellen D.

2017-01-01

We describe our efforts to prepare common starting structures and models for the SAMPL5 blind prediction challenge. We generated the starting input files and single configuration potential energies for the host-guest in the SAMPL5 blind prediction challenge for the GROMACS, AMBER, LAMMPS, DESMOND and CHARMM molecular simulation programs. All conversions were fully automated from the originally prepared AMBER input files using a combination of the ParmEd and InterMol conversion programs. We find that the energy calculations for all molecular dynamics engines for this molecular set agree to a better than 0.1% relative absolute energy for all energy components, and in most cases an order of magnitude better, when reasonable choices are made for different cutoff parameters. However, there are some surprising sources of statistically significant differences. Most importantly, different choices of Coulomb’s constant between programs are one of the largest sources of discrepancies in energies. We discuss the measures required to get good agreement in the energies for equivalent starting configurations between the simulation programs, and the energy differences that occur when simulations are run with program-specific default simulation parameter values. Finally, we discuss what was required to automate this conversion and comparison. PMID:27787702

Lessons learned from comparing molecular dynamics engines on the SAMPL5 dataset

NASA Astrophysics Data System (ADS)

Shirts, Michael R.; Klein, Christoph; Swails, Jason M.; Yin, Jian; Gilson, Michael K.; Mobley, David L.; Case, David A.; Zhong, Ellen D.

2017-01-01

We describe our efforts to prepare common starting structures and models for the SAMPL5 blind prediction challenge. We generated the starting input files and single configuration potential energies for the host-guest in the SAMPL5 blind prediction challenge for the GROMACS, AMBER, LAMMPS, DESMOND and CHARMM molecular simulation programs. All conversions were fully automated from the originally prepared AMBER input files using a combination of the ParmEd and InterMol conversion programs. We find that the energy calculations for all molecular dynamics engines for this molecular set agree to better than 0.1 % relative absolute energy for all energy components, and in most cases an order of magnitude better, when reasonable choices are made for different cutoff parameters. However, there are some surprising sources of statistically significant differences. Most importantly, different choices of Coulomb's constant between programs are one of the largest sources of discrepancies in energies. We discuss the measures required to get good agreement in the energies for equivalent starting configurations between the simulation programs, and the energy differences that occur when simulations are run with program-specific default simulation parameter values. Finally, we discuss what was required to automate this conversion and comparison.

China’s Economic Conditions

DTIC Science & Technology

2008-11-20

occurred during the 1997-1998 Asian financial crisis when it offered financial assistance to Thailand and pledged not to devalue its currency even though...combination of large trade surpluses, foreign direct investment flows, and large-scale purchases of foreign currency have helped make China the world’s largest...Trade Organization (WTO) commitments and to change various economic policies deemed harmful to U.S. economic interests, such as its currency policy

Short-term response of methane fluxes and methanogen activity to water table and soil warming manipulations in an Alaskan peatland

Treesearch

M.R. Turetsky; C.C. Treat; M. Waldrop; J.M. Waddington; J.W. Harden; A.D. McGuire

2008-01-01

Growing season CH4 fluxes were monitored over a two year period following the start of ecosystem-scale manipulations of water table position and surface soil temperatures in a moderate rich fen in interior Alaska. The largest CH4 fluxes occurred in plots that received both flooding (raised water table position) and soil...

The effect of SST emissions on the earth's ozone layer

NASA Technical Reports Server (NTRS)

Whitten, R. C.; Turco, R. P.

1974-01-01

The work presented here is directed toward assessment of environmental effects of the supersonic transport (SST). The model used for the purpose includes vertical eddy transport and the photochemistry of the O-H-N system. It is found that the flight altitude has a pronounced effect on ozone depletion. The largest ozone reduction occurs for NO deposition above an altitude of 20 km.

Forests of the Oregon Coast Range-considerations for ecological restoration

Treesearch

Joe Means; Shu-hei Chen; Jane Kertis; Pete Teensma

1996-01-01

The Oregon Coast Range supports some of the most dense and productive forests in North America. In the pre-harvesting period these forests arose as a result of large fires-the largest covering 330,000 ha (Teensma and others 1991). These fires occurred mostly at intervals of 150 to 300 years. The natural disturbance regime supported a diverse fauna and large populations...

Community structure, biodiversity, and ecosystem services in treeline whitebark pine communities: Potential impacts from a non-native pathogen

Treesearch

Diana F. Tomback; Lynn M. Resler; Robert E. Keane; Elizabeth R. Pansing; Andrew J. Andrade; Aaron C. Wagner

2016-01-01

Whitebark pine (Pinus albicaulis) has the largest and most northerly distribution of any white pine (Subgenus Strobus) in North America, encompassing 18° latitude and 21° longitude in western mountains. Within this broad range, however, whitebark pine occurs within a narrow elevational zone, including upper subalpine and treeline forests, and functions...

Assessment of national strategies for control of high pathogenicity avian influenza and low pathogenicity notifiable avian influenza in poultry, with emphasis on vaccines and vaccination

USDA-ARS?s Scientific Manuscript database

Twenty-nine distinct epizootics of highly pathogenic avian influenza (HPAI) have occurred since 1959. The H5N1 HPAI panzootic affecting Asia, Africa and Eastern Europe has been the largest among these, affecting poultry and/or wild birds in 63 countries. Historically, control strategies have focus...

Mineral resources of Elko County, Nevada

USGS Publications Warehouse

Smith, Roscoe Maurice

1976-01-01

Of the 66 named mining districts in Elko County, 56 have been productive of one or more of 19 different commodities: 11 metals--copper, gold, silver, lead, zinc, mercury, tungsten, manganese, iron, uranium, and antimony; 8 nonmetals--sand and gravel, stone, barite, diatomite, gems, oil shale, volcanic ash, and clay. In addition to the commodities produced, at least 5 others--beryllium, molybdenum, tin, phosphorite, and petroleum, occur in amounts sufficient to warrant exploration. The other districts have been explored, but no production has been recorded. Total value-when-sold of production recorded through 1969 was nearly $91 million; actual production was considerably greater, especially if sand and gravel, barite, and other nonmetallic products before 1953 are included. In value of metals produced, the five highest districts are Mountain City ($26 million), Tuscarora ($11 million), Jarbidge ($10 million), Aura ($6 million), and Railroad (nearly $5 million). The Rio Tinto copper mine in the Mountain City district yielded $21 million. Of the 17 districts that produced nonmetallic minerals, Bootstrap .is the largest producer, containing the Rossi mine, one of the two largest barite mines in the United States. Most of /he metals produced name from veins and replacement deposits in limestone or dolomite near granitic stocks; exceptions are manganese and mercury, which are not associated with known or inferred stocks; mercury is further excepted because it occurs in volcanic rocks, as do a few deposits of the major metals. The largest deposit--the Rio Tinto lode--was a combination of fissure filling and replacement along a bedding plane shear zone 150 ft wide and 1,200 ft long in carbonaceous shale of the Valmy Formation; this deposit is apparently older than the Mountain City stock and its mineralization may be related to Paleozoic mafic volcanism later than a major thrust fault, inferred to underlie the area at a depth of about 5,000 ft. Most of the nonmetallic minerals mined were sedimentary bedded deposits, but mica was mined from pegmatite deposits, and turquoise from both placer and hydrothermal deposits. The largest known reserves of metals (1973) are of porphyry copper in the Dolly Varden district and gold in the Bootstrap district. Reserves of barite also are presumed to be large. The greatest potential for future production of metals, notably copper and gold, appears to be in the known districts or extensions of them and peripheral to deposits that are related to known or concealed plutons and thrust faults. Potential resources in deposits too low in grade to be worked profitably at the present time include all commodities that have been produced and, in addition, known, deposits of beryllium, molybdenum, tin, and phosphorite. Speculative resources in undiscovered deposits may reasonably be predicted to include all known commodities as well as others that are unsuspected. Petroleum may yet be produced from the Elko Formation and geothermal energy from the Ruby Valley and Elko areas.

Seismic hazards at Kilauea and Mauna Loa volcanoes, Hawaii

NASA Astrophysics Data System (ADS)

Klein, Fred W.

1994-04-01

A significant seismic hazard exists in south Hawaii from large tectonic earthquakes that can reach magnitude 8 and intensity XII. This paper quantifies the hazard by estimating the horizontal peak ground acceleration (PGA) in south Hawaii which occurs with a 90% probability of not being exceeded during exposure times from 10 to 250 years. The largest earthquakes occur beneath active, unbuttressed and mobile flanks of volcanos in their shield building stage. The flanks are compressed and pushed laterally by rift zone intrusions. The largest earthquakes are thus not directly caused by volcanic activity. Historic earthquakes (since 1823) and the best Hawaiian Volcano Observatory catalog (since 1970) under the south side of the island define linear frequency-magnitude distributions that imply average recurrence intervals for M greater than 5.5 earthquakes of 3.4-5 years, for M greater than 7 events of 29-44 years, and for M greater than 8 earthquakes of 120-190 years. These estimated recurrences are compatable with the 107 year interval between the two major April 2, 1868 (M(approximately)7.9) and November 29, 1975 (M=7.2) earthquakes. Frequency-magnitude distributions define the activity levels of 19 different seismic source zones for probabilistic ground motion estimations. The available measurements of PGA (33 from 7 moderate earthquakes) are insufficient to define a new attenuation curve. We use the Boore et al. (1993) curve shifted upward by a factor of 1.2 to fit Hawaiian data. Amplification of sites on volcanic ash or unconsolidated soil are about two times those of hard lava sites. On a map for a 50 year exposure time with a 90% probability of not being exceeded, the peak ground accelerations are 1.0 g Kilauea's and Mauna Loa's mobile south flanks and 0.9 g in the Kaoiki seismic zone. This hazard from strong ground shaking is comparable to that near the San Andreas Fault in California or the subduction zone in the Gulf of Alaska.

Seismotectonics of the May 19, 2011 Simav- Kutahya Earthquake Activity

NASA Astrophysics Data System (ADS)

Komec Mutlu, Ahu

2014-05-01

Aftershock sequence of May 19, 2011 Simav earthquake (Mw = 5.8) is relocated with a new 1-D seismic velocity model and focal mechanisms of largest aftershocks are determined. The May 19, 2011 Simav-Kutahya earthquake is occured in the most seismically active region of western Turkey. During six months after the mainshock, more than 5000 earthquakes are recorded and aftershocks followed over a period of almost two years. In this study, more than 7600 aftershocks occured between years 2011 and 2012 with magnitudes greater than 1.8 relocated. Waveform data is collected by 13 three component seismic stations from three different networks (Kandilli Observatory and Earthquake Research Institute (NEMC-National Earthquake Monitoring Center), Prime Ministry Disaster and Emergency Management Presidency, Department of Earthquake and Canakkale Onsekiz Mart University Geophysics Department). These seismic stations are deployed closer than 80 km epicentral distance in the Simav-Kutahya. Average crustal velocity and average crustal thickness for the region are computed as 5.68 km/sn and 37.6 km, respectively. The source mechanism of fifty aftershocks with magnitudes greater than 4.0 are derived from first motion P phases. Analysis of focal mechanisms indicate mainly normal fault motions with oblique slip.

Review of eruptive activity at Tianchi volcano, Changbaishan, northeast China: implications for possible future eruptions

NASA Astrophysics Data System (ADS)

Wei, Haiquan; Liu, Guoming; Gill, James

2013-04-01

One of the largest explosive eruptions in the past several thousand years occurred at Tianchi volcano, also known as Changbaishan, on the China-North Korea border. This historically active polygenetic central volcano consists of three parts: a lower basaltic shield, an upper trachytic composite cone, and young comendite ash flows. The Millennium Eruption occurred between 938 and 946 ad, and was preceded by two smaller and chemically different rhyolitic pumice deposits. There has been at least one additional, small eruption in the last three centuries. From 2002 to 2005, seismicity, deformation, and the helium and hydrogen gas contents of spring waters all increased markedly, causing regional concern. We attribute this event to magma recharge or volatile exhalation or both at depth, followed by two episodes of addition of magmatic fluids into the overlying aquifer without a phreatic eruption. The estimated present magma accumulation rate is too low by itself to account for the 2002-2005 unrest. The most serious volcanic hazards are ash eruption and flows, and lahars. The available geological information and volcano monitoring data provide a baseline for comprehensive assessment of future episodes of unrest and possible eruptive activity.

Modelling the Wake of the Marquesas Archipelago

NASA Astrophysics Data System (ADS)

Raapoto, H.; Martinez, E. C.; Petrenko, A. A.; Doglioli, A. M.; Maes, C.

2017-12-01

In this study, a high-resolution ( 2.5 km) numerical model was set up to investigate the fine-scale activity within the region of the Marquesas archipelago where a strong biological enhancement occurs. This has never been performed before. The robustness of the model results is assessed by comparison with remote sensing and in situ observations. Our results highlight regions of warm waters leeward of the different islands with high eddy kinetic energy (EKE) on their sides. The analysis of energy conversion terms reveals contributions to EKE variability by wind, baroclinic and barotropic instabilities. The use of a geometry-based eddy detection algorithm reveals eddy generation in the wake of the largest islands, with both an inshore and offshore effect. Maximum eddy activity occurs in austral winter following the seasonality of both wind stress and EKE intensity. Most eddies have a radius between 20 and 30 km and are generally cyclonic rather than anticyclonic. Significant vertical velocities are observed in the proximity of the islands, associated with topography induced flow separation. Eddy trapping inshore waters are advected offshore in the wake of the islands. The overall influence of these fine-scale dynamics could explain the strong biological enhancement of the archipelago.

Ballistic and Diffusive Thermal Conductivity of Graphene

NASA Astrophysics Data System (ADS)

Saito, Riichiro; Masashi, Mizuno; Dresselhaus, Mildred S.

2018-02-01

This paper is a contribution to the Physical Review Applied collection in memory of Mildred S. Dresselhaus. Phonon-related thermal conductivity of graphene is calculated as a function of the temperature and sample size of graphene in which the crossover of ballistic and diffusive thermal conductivity occurs at around 100 K. The diffusive thermal conductivity of graphene is evaluated by calculating the phonon mean free path for each phonon mode in which the anharmonicity of a phonon and the phonon scattering by a 13C isotope are taken into account. We show that phonon-phonon scattering of out-of-plane acoustic phonon by the anharmonic potential is essential for the largest thermal conductivity. Using the calculated results, we can design the optimum sample size, which gives the largest thermal conductivity at a given temperature for applying thermal conducting devices.

Effects of Nuclear Cross Sections at Different Energies on the Radiation Hazard from Galactic Cosmic Rays

NASA Technical Reports Server (NTRS)

Lin, Z. W.; Adams, J. H., Jr.

2006-01-01

The radiation hazard for astronauts from galactic cosmic rays is a major obstacle in long duration human space explorations. Space radiation transport codes have been developed to calculate radiation environment on missions to the Moon, Mars or beyond. We have studied how uncertainties in fragmentation cross sections at different energies affect the accuracy of predictions from such radiation transport. We find that, in deep space, cross sections between 0.3 and 0.85 GeV/u usually have the largest effect on dose-equivalent behind shielding in solar minimum GCR environments, and cross sections between 0.85 and 1.2 GeV/u have the largest effect in solar maximum GCR environments. At the International Space Station, cross sections at higher energies have the largest effect due to the geomagnetic cutoff.

Influence of geomagnetic activity and atmospheric pressure in hypertensive adults.

PubMed

Azcárate, T; Mendoza, B

2017-09-01

We performed a study of the systolic and diastolic arterial blood pressure behavior under natural variables such as the atmospheric pressure and the horizontal geomagnetic field component. We worked with a group of eight adult hypertensive volunteers, four men and four women, with ages between 18 and 27 years in Mexico City during a geomagnetic storm in 2014. The data was divided by gender, age, and day/night cycle. We studied the time series using three methods: correlations, bivariate analysis, and superposed epoch (within a window of 2 days around the day of occurrence of a geomagnetic storm) analysis, between the systolic and diastolic blood pressure and the natural variables. The correlation analysis indicated a correlation between the systolic and diastolic blood pressure and the atmospheric pressure and the horizontal geomagnetic field component, being the largest during the night. Furthermore, the correlation and bivariate analyses showed that the largest correlations are between the systolic and diastolic blood pressure and the horizontal geomagnetic field component. Finally, the superposed epoch analysis showed that the largest number of significant changes in the blood pressure under the influence of geomagnetic field occurred in the systolic blood pressure for men.

Influence of geomagnetic activity and atmospheric pressure in hypertensive adults

NASA Astrophysics Data System (ADS)

Azcárate, T.; Mendoza, B.

2017-09-01

We performed a study of the systolic and diastolic arterial blood pressure behavior under natural variables such as the atmospheric pressure and the horizontal geomagnetic field component. We worked with a group of eight adult hypertensive volunteers, four men and four women, with ages between 18 and 27 years in Mexico City during a geomagnetic storm in 2014. The data was divided by gender, age, and day/night cycle. We studied the time series using three methods: correlations, bivariate analysis, and superposed epoch (within a window of 2 days around the day of occurrence of a geomagnetic storm) analysis, between the systolic and diastolic blood pressure and the natural variables. The correlation analysis indicated a correlation between the systolic and diastolic blood pressure and the atmospheric pressure and the horizontal geomagnetic field component, being the largest during the night. Furthermore, the correlation and bivariate analyses showed that the largest correlations are between the systolic and diastolic blood pressure and the horizontal geomagnetic field component. Finally, the superposed epoch analysis showed that the largest number of significant changes in the blood pressure under the influence of geomagnetic field occurred in the systolic blood pressure for men.

Oklahoma experiences largest earthquake during ongoing regional wastewater injection hazard mitigation efforts

USGS Publications Warehouse

Yeck, William; Hayes, Gavin; McNamara, Daniel E.; Rubinstein, Justin L.; Barnhart, William; Earle, Paul; Benz, Harley M.

2017-01-01

The 3 September 2016, Mw 5.8 Pawnee earthquake was the largest recorded earthquake in the state of Oklahoma. Seismic and geodetic observations of the Pawnee sequence, including precise hypocenter locations and moment tensor modeling, shows that the Pawnee earthquake occurred on a previously unknown left-lateral strike-slip basement fault that intersects the mapped right-lateral Labette fault zone. The Pawnee earthquake is part of an unprecedented increase in the earthquake rate in Oklahoma that is largely considered the result of the deep injection of waste fluids from oil and gas production. If this is, indeed, the case for the M5.8 Pawnee earthquake, then this would be the largest event to have been induced by fluid injection. Since 2015, Oklahoma has undergone wide-scale mitigation efforts primarily aimed at reducing injection volumes. Thus far in 2016, the rate of M3 and greater earthquakes has decreased as compared to 2015, while the cumulative moment—or energy released from earthquakes—has increased. This highlights the difficulty in earthquake hazard mitigation efforts given the poorly understood long-term diffusive effects of wastewater injection and their connection to seismicity.

The 2007 Boso Slow Slip Event and the associated earthquake swarm

NASA Astrophysics Data System (ADS)

Sekine, S.; Hirose, H.; Kimura, H.; Obara, K.

2007-12-01

In the Boso Peninsula, which is located in southeast of the Japan mainland, slow slip events (SSE) have been observed by the GEONET GPS array operated by the Geographical Survey Institute Japan and the NIED tiltmeter network every 6-7 years (Ozawa et al.,2003; NIED 2003). The unique characteristics of the Boso SSE are that earthquake swarm activities have also occurred in association with the SSE. The latest activity of the SSE and the earthquake swarm took place in August 2007. On 13th August, an earthquake swarm began to occur at east off Boso Peninsula and the slow tilt deformations also started. The earthquake sources migrated to the NNE direction, which is the same direction of the relative plate motion of the subducting Philippine Sea Plate with respect to the overriding plate. The largest earthquake in this episode (Mw 5.3) occurred on 16th and the second largest one (Mw 5.2) on 18th. Most of the larger earthquakes show low- angle thrust type focal mechanisms that are consistent with the plate motion and the geometry of the subduction plate interface. The tilt changes seem to stop on 17th and the activity of the swarm rapidly decreases after 19th. The maximum tilt change of 0.8 micro radian with northwest down tilting was observed at KT2H, the nearest station from the source region. Based on the tilt records around Boso Peninsula, we estimate a fault model for the SSE using genetic algorithm inversion to non-linear parameter and the weighted least squares method to linear parameters. As a result, the estimated moment magnitude and the amount of slip are 6.4 and 10 cm, respectively. The size and the location of the SSE are similar to the previous episodes. The estimated fault plane is very consistent with the configuration of the plate interface (Kimura et al., 2006). Most of the earthquakes are located on the deeper edge of the estimated SSE fault area. The coincidence of the swarm and the SSE suggests a causal relation between them and may help us to understand the mechanism of earthquake triggering. On the other hand, in the southwest Japan, tremors which repeat at approximately six months have occurred in association with the SSE. To compare with these two types of SSE may suggest the difference of the boundary conditions on the same subducting plate.

Taking the metabolic pulse of the world's coral reefs.

PubMed

Cyronak, Tyler; Andersson, Andreas J; Langdon, Chris; Albright, Rebecca; Bates, Nicholas R; Caldeira, Ken; Carlton, Renee; Corredor, Jorge E; Dunbar, Rob B; Enochs, Ian; Erez, Jonathan; Eyre, Bradley D; Gattuso, Jean-Pierre; Gledhill, Dwight; Kayanne, Hajime; Kline, David I; Koweek, David A; Lantz, Coulson; Lazar, Boaz; Manzello, Derek; McMahon, Ashly; Meléndez, Melissa; Page, Heather N; Santos, Isaac R; Schulz, Kai G; Shaw, Emily; Silverman, Jacob; Suzuki, Atsushi; Teneva, Lida; Watanabe, Atsushi; Yamamoto, Shoji

2018-01-01

Worldwide, coral reef ecosystems are experiencing increasing pressure from a variety of anthropogenic perturbations including ocean warming and acidification, increased sedimentation, eutrophication, and overfishing, which could shift reefs to a condition of net calcium carbonate (CaCO3) dissolution and erosion. Herein, we determine the net calcification potential and the relative balance of net organic carbon metabolism (net community production; NCP) and net inorganic carbon metabolism (net community calcification; NCC) within 23 coral reef locations across the globe. In light of these results, we consider the suitability of using these two metrics developed from total alkalinity (TA) and dissolved inorganic carbon (DIC) measurements collected on different spatiotemporal scales to monitor coral reef biogeochemistry under anthropogenic change. All reefs in this study were net calcifying for the majority of observations as inferred from alkalinity depletion relative to offshore, although occasional observations of net dissolution occurred at most locations. However, reefs with lower net calcification potential (i.e., lower TA depletion) could shift towards net dissolution sooner than reefs with a higher potential. The percent influence of organic carbon fluxes on total changes in dissolved inorganic carbon (DIC) (i.e., NCP compared to the sum of NCP and NCC) ranged from 32% to 88% and reflected inherent biogeochemical differences between reefs. Reefs with the largest relative percentage of NCP experienced the largest variability in seawater pH for a given change in DIC, which is directly related to the reefs ability to elevate or suppress local pH relative to the open ocean. This work highlights the value of measuring coral reef carbonate chemistry when evaluating their susceptibility to ongoing global environmental change and offers a baseline from which to guide future conservation efforts aimed at preserving these valuable ecosystems.

Taking the metabolic pulse of the world’s coral reefs

PubMed Central

Andersson, Andreas J.; Langdon, Chris; Albright, Rebecca; Bates, Nicholas R.; Caldeira, Ken; Carlton, Renee; Corredor, Jorge E.; Dunbar, Rob B.; Enochs, Ian; Erez, Jonathan; Eyre, Bradley D.; Gattuso, Jean-Pierre; Gledhill, Dwight; Kayanne, Hajime; Kline, David I.; Koweek, David A.; Lantz, Coulson; Lazar, Boaz; Manzello, Derek; McMahon, Ashly; Meléndez, Melissa; Page, Heather N.; Santos, Isaac R.; Schulz, Kai G.; Shaw, Emily; Silverman, Jacob; Suzuki, Atsushi; Teneva, Lida; Watanabe, Atsushi; Yamamoto, Shoji

2018-01-01

Worldwide, coral reef ecosystems are experiencing increasing pressure from a variety of anthropogenic perturbations including ocean warming and acidification, increased sedimentation, eutrophication, and overfishing, which could shift reefs to a condition of net calcium carbonate (CaCO3) dissolution and erosion. Herein, we determine the net calcification potential and the relative balance of net organic carbon metabolism (net community production; NCP) and net inorganic carbon metabolism (net community calcification; NCC) within 23 coral reef locations across the globe. In light of these results, we consider the suitability of using these two metrics developed from total alkalinity (TA) and dissolved inorganic carbon (DIC) measurements collected on different spatiotemporal scales to monitor coral reef biogeochemistry under anthropogenic change. All reefs in this study were net calcifying for the majority of observations as inferred from alkalinity depletion relative to offshore, although occasional observations of net dissolution occurred at most locations. However, reefs with lower net calcification potential (i.e., lower TA depletion) could shift towards net dissolution sooner than reefs with a higher potential. The percent influence of organic carbon fluxes on total changes in dissolved inorganic carbon (DIC) (i.e., NCP compared to the sum of NCP and NCC) ranged from 32% to 88% and reflected inherent biogeochemical differences between reefs. Reefs with the largest relative percentage of NCP experienced the largest variability in seawater pH for a given change in DIC, which is directly related to the reefs ability to elevate or suppress local pH relative to the open ocean. This work highlights the value of measuring coral reef carbonate chemistry when evaluating their susceptibility to ongoing global environmental change and offers a baseline from which to guide future conservation efforts aimed at preserving these valuable ecosystems. PMID:29315312

Mechanics of the human hamstring muscles during sprinting.

PubMed

Schache, Anthony G; Dorn, Tim W; Blanch, Peter D; Brown, Nicholas A T; Pandy, Marcus G

2012-04-01

An understanding of hamstring mechanics during sprinting is important for elucidating why these muscles are so vulnerable to acute strain-type injury. The purpose of this study was twofold: first, to quantify the biomechanical load (specifically, musculotendon strain, velocity, force, power, and work) experienced by the hamstrings across a full stride cycle; and second, to determine how these parameters differ for each hamstring muscle (i.e., semimembranosus (SM), semitendinosus (ST), biceps femoris long head (BF), biceps femoris short head (BF)). Full-body kinematics and ground reaction force data were recorded simultaneously from seven subjects while sprinting on an indoor running track. Experimental data were integrated with a three-dimensional musculoskeletal computer model comprised of 12 body segments and 92 musculotendon structures. The model was used in conjunction with an optimization algorithm to calculate musculotendon strain, velocity, force, power, and work for the hamstrings. SM, ST, and BF all reached peak strain, produced peak force, and formed much negative work (energy absorption) during terminal swing. The biomechanical load differed for each hamstring muscle: BF exhibited the largest peak strain, ST displayed the greatest lengthening velocity, and SM produced the highest peak force, absorbed and generated the most power, and performed the largest amount of positive and negative work. As peak musculotendon force and strain for BF, ST, and SM occurred around the same time during terminal swing, it is suggested that this period in the stride cycle may be when the biarticular hamstrings are at greatest injury risk. On this basis, hamstring injury prevention or rehabilitation programs should preferentially target strengthening exercises that involve eccentric contractions performed with high loads at longer musculotendon lengths.

Comparison of the November 2002 Denali and November 2001 Kunlun Earthquakes

NASA Astrophysics Data System (ADS)

Bufe, C. G.

2002-12-01

Major earthquakes occurred in Tibet on the central Kunlun fault (M 7.8) on November 14, 2001 (Lin and others, 2002) and in Alaska on the central Denali fault (M 7.9) on November 3, 2002. Both earthquakes generated large surface waves (Kunlun Ms 8.0 (USGS) and Denali Ms 8.5). Each event occurred on east-west-trending strike-slip faults and exhibited nearly unilateral rupture propagating several hundred kilometers from west to east. Surface rupture length estimates were about 400 km for Kunlun, 300 km for Denali. Maximum surface faulting and moment release were observed far to the east of the points of rupture initiation. Harvard moment centroids were located east of USGS epicenters by 182 km (Kunlun) and by 126 km (Denali). Maximum surface faulting was observed near 240 km (Kunlun, 16 m left lateral) and near 175 km (Denali, 9 m right lateral) east of the USGS epicenters. Significant thrust components were observed in the initiation of the Denali event (ERI analysis and mapped thrust) and in the termination of the Kunlun rupture, as evidenced by thrust mechanisms of the largest aftershocks which occurred near the eastern part of the Kunlun rupture. In each sequence the largest aftershock was about 2 orders of magnitude smaller than the mainshock. Moment release along the ruptured segments was examined for the 25-year periods preceding the main shocks. The Denali zone shows precursory accelerating moment release with the dominant events occurring on October 22, 1996 (M 5.8) and October 23, 2002 (M 6.7). The Kunlun zone shows nearly constant moment release over time with the last significant event before the main shock occurring on November 26, 2000 (M 5.4). Moment release data are consistent with previous observations of annual periodicity preceding major earthquakes, possibly due to the evolution of a critical state with seasonal and tidal triggering (Varnes and Bufe, 2001). Annual periodicity is also evident for the larger events in the greater San Francisco Bay region over several decades preceding the 1906 San Francisco earthquake (M 7.8). Both the Kunlun and the Denali mainshocks occurred at new moon.

Hazard Assessment and Early Warning of Tsunamis: Lessons from the 2011 Tohoku earthquake

NASA Astrophysics Data System (ADS)

Satake, K.

2012-12-01

The March 11, 2011 Tohoku earthquake (M 9.0) was the largest earthquake in Japanese history, and was the best recorded subduction-zone earthquakes in the world. In particular, various offshore geophysical observations revealed large horizontal and vertical seafloor movements, and the tsunami was recorded on high-quality, high-sampling gauges. Analysis of such tsunami waveforms shows a temporal and spatial slip distribution during the 2011 Tohoku earthquake. The fault rupture started near the hypocenter and propagated into both deep and shallow parts of the plate interface. Very large, ~25 m, slip off Miyagi on the deep part of plate interface corresponds to an interplate earthquake of M 8.8, the location and size similar to 869 Jogan earthquake model, and was responsible for the large tsunami inundation in Sendai and Ishinomaki plains. Huge slip, more than 50 m, occurred on the shallow part near the trench axis ~3 min after the earthquake origin time. This delayed shallow rupture (M 8.8) was similar to the 1896 "tsunami earthquake," and was responsible for the large tsunami on the northern Sanriku coast, measured at ~100 km north of the largest slip. Thus the Tohoku earthquake can be decomposed into an interplate earthquake and the triggered "tsunami earthquake." The Japan Meteorological Agency issued tsunami warning 3 minutes after the earthquake, and saved many lives. However, their initial estimation of tsunami height was underestimated, because the earthquake magnitude was initially estimated as M 7.9, hence the computed tsunami heights were lower. The JMA attempts to improve the tsunami warning system, including technical developments to estimate the earthquake size in a few minutes by using various and redundant information, to deploy and utilize the offshore tsunami observations, and to issue a warning based on the worst case scenario if a possibility of giant earthquake exists. Predicting a trigger of another large earthquake would still be a challenge. Tsunami hazard assessments or long-term forecast of earthquakes have not considered such a triggering or simultaneous occurrence of different types of earthquakes. The large tsunami at the Fukushima nuclear power station was due to the combination of the deep and shallow slip. Disaster prevention for low-frequency but large-scale hazard must be considered. The Japanese government established a general policy to for two levels: L1 and L2. The L2 tsunamis are the largest possible tsunamis with low frequency of occurrence, but cause devastating disaster once they occur. For such events, saving people's lives is the first priority and soft measures such as tsunami hazard maps, evacuation facilities or disaster education will be prepared. The L1 tsunamis are expected to occur more frequently, typically once in a few decades, for which hard countermeasures such as breakwater must be prepared to protect lives and properties of residents as well as economic and industrial activities.

Seismic Hazard and Fault Length

NASA Astrophysics Data System (ADS)

Black, N. M.; Jackson, D. D.; Mualchin, L.

2005-12-01

If mx is the largest earthquake magnitude that can occur on a fault, then what is mp, the largest magnitude that should be expected during the planned lifetime of a particular structure? Most approaches to these questions rely on an estimate of the Maximum Credible Earthquake, obtained by regression (e.g. Wells and Coppersmith, 1994) of fault length (or area) and magnitude. Our work differs in two ways. First, we modify the traditional approach to measuring fault length, to allow for hidden fault complexity and multi-fault rupture. Second, we use a magnitude-frequency relationship to calculate the largest magnitude expected to occur within a given time interval. Often fault length is poorly defined and multiple faults rupture together in a single event. Therefore, we need to expand the definition of a mapped fault length to obtain a more accurate estimate of the maximum magnitude. In previous work, we compared fault length vs. rupture length for post-1975 earthquakes in Southern California. In this study, we found that mapped fault length and rupture length are often unequal, and in several cases rupture broke beyond the previously mapped fault traces. To expand the geologic definition of fault length we outlined several guidelines: 1) if a fault truncates at young Quaternary alluvium, the fault line should be inferred underneath the younger sediments 2) faults striking within 45° of one another should be treated as a continuous fault line and 3) a step-over can link together faults at least 5 km apart. These definitions were applied to fault lines in Southern California. For example, many of the along-strike faults lines in the Mojave Desert are treated as a single fault trending from the Pinto Mountain to the Garlock fault. In addition, the Rose Canyon and Newport-Inglewood faults are treated as a single fault line. We used these more generous fault lengths, and the Wells and Coppersmith regression, to estimate the maximum magnitude (mx) for the major faults in southern California. Then we compared our mx values with those proposed by CALTRANS, and those assumed in the 2002 USGS/CGS hazard model. To calculate the planning magnitude mp we assumed a truncated Gutenberg-Richter magnitude distribution with parameters a, b, and mx. We fixed b and solved for the a-value in terms of mx, b, and the tectonic moment rate. For many faults mp is relatively insensitive to mx and typically falls off at higher magnitudes because the a-value decreases with increasing mx when the moment rate is constrained. Furthermore, we find that by increasing mx the cumulative earthquake rate actually decreases for smaller magnitude (5 and 6) events. This suggests that fewer magnitude 5 and 6 earthquakes are required to balance the moment budget if larger, but highly infrequent, earthquakes are allowed to occur.

Association of monthly frequencies of diverse diseases in the calls to the public emergency service of the city of Buenos Aires during 1999-2004 with meteorological variables and seasons.

PubMed

Alexander, P

2013-01-01

This work aims to study associations between monthly averages of meteorological variables and monthly frequencies of diverse diseases in the calls to the public ambulance emergency service of the city of Buenos Aires during the years 1999-2004. Throughout this time period no changes were made in the classification codes of the illnesses. Heart disease, arrhythmia, heart failure, cardiopulmonary arrest, angina pectoris, psychiatric diseases, stroke, transient ischemic attack, syncope and the total number of calls were analyzed against 11 weather variables and the four seasons. All illnesses exhibited some seasonal behavior, except cardiorespiratory arrest and angina pectoris. The largest frequencies of illnesses that exhibited some association with the meteorological variables used to occur in winter, except the psychiatric cases. Heart failure, stroke, psychiatric diseases and the total number of calls showed significant correlations with the 11 meteorological variables considered, and the largest indices (absolute values above 0.6) were found for the former two pathologies. On the other side, cardiorespiratory arrest and angina pectoris revealed no significant correlations and nearly null indices. Variables associated with temperature were the meteorological proxies with the largest correlations against diseases. Pressure and humidity mostly exhibited positive correlations, which is the opposite of variables related to temperature. Contrary to all other diseases, psychiatric pathologies showed a clear predominance of positive correlations. Finally, the association degree of the medical dataset with recurrent patterns was further evaluated through Fourier analysis, to assess the presence of statistically significant behavior. In the Northern Hemisphere high morbidity and mortality rates in December are usually assigned to diverse factors in relation to the holidays, but such an effect is not observed in the present analysis. There seems to be no clearly preferred meteorological proxy among the different types of temperatures used. It is shown that the amount of occurrences depends mainly on season rather on its strength quantified by temperature.

Association of monthly frequencies of diverse diseases in the calls to the public emergency service of the city of Buenos Aires during 1999-2004 with meteorological variables and seasons

NASA Astrophysics Data System (ADS)

Alexander, P.

2013-01-01

This work aims to study associations between monthly averages of meteorological variables and monthly frequencies of diverse diseases in the calls to the public ambulance emergency service of the city of Buenos Aires during the years 1999-2004. Throughout this time period no changes were made in the classification codes of the illnesses. Heart disease, arrhythmia, heart failure, cardiopulmonary arrest, angina pectoris, psychiatric diseases, stroke, transient ischemic attack, syncope and the total number of calls were analyzed against 11 weather variables and the four seasons. All illnesses exhibited some seasonal behavior, except cardiorespiratory arrest and angina pectoris. The largest frequencies of illnesses that exhibited some association with the meteorological variables used to occur in winter, except the psychiatric cases. Heart failure, stroke, psychiatric diseases and the total number of calls showed significant correlations with the 11 meteorological variables considered, and the largest indices (absolute values above 0.6) were found for the former two pathologies. On the other side, cardiorespiratory arrest and angina pectoris revealed no significant correlations and nearly null indices. Variables associated with temperature were the meteorological proxies with the largest correlations against diseases. Pressure and humidity mostly exhibited positive correlations, which is the opposite of variables related to temperature. Contrary to all other diseases, psychiatric pathologies showed a clear predominance of positive correlations. Finally, the association degree of the medical dataset with recurrent patterns was further evaluated through Fourier analysis, to assess the presence of statistically significant behavior. In the Northern Hemisphere high morbidity and mortality rates in December are usually assigned to diverse factors in relation to the holidays, but such an effect is not observed in the present analysis. There seems to be no clearly preferred meteorological proxy among the different types of temperatures used. It is shown that the amount of occurrences depends mainly on season rather on its strength quantified by temperature.

Seafloor seismological/geodetic observations in the rupture area of the 2011 Tohoku-oki Earthquake

NASA Astrophysics Data System (ADS)

Hino, Ryota; Shinohara, Masanao; Ito, Yoshihiro

2016-04-01

A number of important aspects of the 2011 Tohoku-oki earthquake (Mw 9.0) were clarified by the seafloor seismological and geodetic observation above the rupture area of the earthquake. Besides the extraordinarily large coseismic displacements, various kinds of slow slip phenomena associated with intensive micro-seismicity on the plate boundary fault were identified by near field ocean bottom seismographs and seafloor geodetic observation networks. The Tohoku-oki earthquake was preceded by evident foreshock activity with a spatial expansion of this seismicity. The activity became significantly intense after the occurrence of the largest foreshock two days before the mainshock rupture. During the period, clear continuous seafloor deformation was identified caused by the aseismic slip following the largest foreshock. Another different type of aseismic slip event had occurred before this pre-imminent activity had started about a month before the largest foreshock happened. The observed increased seismicity associated with aseismic slip suggests that there must have been some chain reaction like interplay of seismic and interseismic slips before the large earthquake broke out. However, no evident deformation signals were observed indicating acceleration of fault slip immediately before the mainshock. Seafloor geodetic measurements reveals that the postseismic deformation around the rupture area of the Tohoku-oki earthquake shows complex spatial pattern and the complexity is mostly due to significant viscoelastic relaxation induced by the huge coseismic slip. The effects of viscoelastic deformation makes it difficult to identify the deformation associated with the after slip or regaining of interplate coupling and requires us to enhance the abilities of seafloor monitoring to detect the slip activities on the fault. We started an array of seismometer arrays observation including broad-band seismographs to detect and locate slow-slip events and low-frequency tremors. Another observation we started is direct-path acoustic ranging across the trench axis. Slip rate of the shallow fault can be measured by monitoring the change in distance between the benchmarks on the incoming and overrding plates.

Data Assimilation by Ensemble Kalman Filter during One-Dimensional Nonlinear Consolidation in Randomly Heterogeneous Highly Compressible Aquitards

NASA Astrophysics Data System (ADS)

Zapata Norberto, B.; Morales-Casique, E.; Herrera, G. S.

2017-12-01

Severe land subsidence due to groundwater extraction may occur in multiaquifer systems where highly compressible aquitards are present. The highly compressible nature of the aquitards leads to nonlinear consolidation where the groundwater flow parameters are stress-dependent. The case is further complicated by the heterogeneity of the hydrogeologic and geotechnical properties of the aquitards. We explore the effect of realistic vertical heterogeneity of hydrogeologic and geotechnical parameters on the consolidation of highly compressible aquitards by means of 1-D Monte Carlo numerical simulations. 2000 realizations are generated for each of the following parameters: hydraulic conductivity (K), compression index (Cc) and void ratio (e). The correlation structure, the mean and the variance for each parameter were obtained from a literature review about field studies in the lacustrine sediments of Mexico City. The results indicate that among the parameters considered, random K has the largest effect on the ensemble average behavior of the system. Random K leads to the largest variance (and therefore largest uncertainty) of total settlement, groundwater flux and time to reach steady state conditions. We further propose a data assimilation scheme by means of ensemble Kalman filter to estimate the ensemble mean distribution of K, pore-pressure and total settlement. We consider the case where pore-pressure measurements are available at given time intervals. We test our approach by generating a 1-D realization of K with exponential spatial correlation, and solving the nonlinear flow and consolidation problem. These results are taken as our "true" solution. We take pore-pressure "measurements" at different times from this "true" solution. The ensemble Kalman filter method is then employed to estimate ensemble mean distribution of K, pore-pressure and total settlement based on the sequential assimilation of these pore-pressure measurements. The ensemble-mean estimates from this procedure closely approximate those from the "true" solution. This procedure can be easily extended to other random variables such as compression index and void ratio.

Microwave Limb Sounder Measurements Depicting the Relationship Between Nitrous Oxide Levels and

NASA Technical Reports Server (NTRS)

2005-01-01

Aura's Microwave Limb Sounder measures nitrous oxide, which is unaffected by stratospheric chemical processes. By studying changes in its levels, scientists can better understand how air is moving around and how ozone is affected by that air motion, allowing them to differentiate those changes from the ones caused by chemical ozone destruction. In these cross-sections of nitrous oxide (top) and ozone (bottom) data from Aura, changes in the levels of these two chemicals at various temperatures and latitudes are depicted over time. The white contour shows the approximate location of the polar vortex boundary.

The left panel data were collected on January 23, 2005, near the beginning of chemical ozone destruction this winter. Virtually all chemical loss occurred before March 10 (center panel). Ozone destruction extended throughout the polar vortex from about 15-20 kilometers (9-13 miles), but occurred only in the outer part of the vortex from 20-25 kilometers (13-16 miles). The differences between the two days are depicted in the right panel. The largest observed difference is about a 1.2 parts per million by volume decrease in ozone. Plots of nitrous oxide show a decrease in the region in the outer part of the vortex where most ozone loss occurs, indicating that air from above (where nitrous oxide is lower) has moved into this region. This downward motion brings higher ozone into the region where chemical loss is occurring, thus partially masking the effects of chemical loss. Calculations using Microwave Limb Sounder data to separate dynamical and chemical effects indicate maximum chemical ozone loss of approximately 2 parts per million by volume (approximately 60 percent) in the outer part of the vortex near 18-21 kilometers (11-13 miles), and approximately 1.5 parts per million by volume when averaged throughout the whole vortex region.

The white-margined penstemon (Penstemon albomarginatus Jones), a rare Mohave Desert species, and the Hualapai Mountains land exchange in Mohave County, Arizona

Treesearch

John L. Anderson

2001-01-01

The white-margined penstemon (Penstemon albomarginatus Jones) is a rare Mohave Desert species with an unusual tripartite distribution with disjunct localities in Arizona, California, and Nevada. The Arizona population is the largest single population occurring with a range of 15 miles by 5 miles in Dutch Flat near Yucca, Arizona in Mohave County. The land ownership...

Virulence for mice, resistance to synthetic gastric fluid, and biofilm formation of Listeria monocytogenes H7550, a serotype 4b strain isolated from frankfurters associated with the BilMar listeriosis outbreak

USDA-ARS?s Scientific Manuscript database

Introduction: One of the largest and most severe listeriosis outbreaks in the United States occurred in 1998 as a result of contamination of frankfurters with a serotype 4b strain of Listeria monocytogenes. However, there has been little characterization of the virulence attributes of strains reta...

Regional Seismic Studies in Central Asia

DTIC Science & Technology

1994-01-17

volcanism occurred over a 5 to 10 million year duration, much longer than the duration of the Deccan Traps or Columbia River flood basalts and...the site of the Siberian Traps flhod basalts. These flows possibly represent the largest Mesozoic occurrence of conitinental flood .basalt, and now...areas of continental flood basalts [White & McKenzie, 1989] nor is there a clear connection between tEle Siberian Traps and a mantle hot spot although

Survival of Phytophthora ramorum following wildfires in the sudden oak death-impacted forests of the Big Sur region

Treesearch

Maia M. Beh; Margaret Metz; Kerri Frangioso; David Rizzo

2013-01-01

The summer of 2008 brought the first wildfires to occur in known Phytophthora ramorum-infested forests in California, with the largest individual fire burning in the Big Sur region of the central coast (Monterey County) (Metz et al. 2011). More than 100,000 ha in Big Sur were ultimately burned that summer, providing a natural experiment to examine...

Solar Irradiance Variations on Active Region Time Scales

NASA Technical Reports Server (NTRS)

Labonte, B. J. (Editor); Chapman, G. A. (Editor); Hudson, H. S. (Editor); Willson, R. C. (Editor)

1984-01-01

The variations of the total solar irradiance is an important tool for studying the Sun, thanks to the development of very precise sensors such as the ACRIM instrument on board the Solar Maximum Mission. The largest variations of the total irradiance occur on time scales of a few days are caused by solar active regions, especially sunspots. Efforts were made to describe the active region effects on total and spectral irradiance.

New SIMS U-Pb age constraints on the largest lake transgression event in the Songliao Basin, NE China.

PubMed

Xi, Dangpeng; He, Huaiyu; Yu, Zhiqiang; Huang, Qinghua; Hu, Jianfang; Xu, Yankang; Shi, Zhongye; Qin, Zuohuan; Wan, Xiaoqiao

2018-01-01

The largest lake transgression event (LTE) associated with lake anoxic events (LAE) and periodic seawater incursion events (SWIE) in the Songliao Basin, northeastern China, occurred during deposition of the Cretaceous Nenjiang Formation. The Yaojia-Nenjiang Formation boundary (YNB) marks the beginning of the LTE, as well as LAE and SWIE. However, there is an absence of direct radioisotopic dating, and therefore the age of the YNB, as well as the beginning of LTE, together with their relationship with other geological events, is strongly debated. Here we present a new SIMS U-Pb zircon age from the lowermost Nenjiang Formation. The bentonite bed located 9.88 m above the YNB of the X1-4 borehole was analyzed. Twenty-five analyses of 25 zircons were conducted, which produced a weighted mean age of 85.5±0.6 Ma (MSWD = 0.87). Based on the average sediment accumulation rate, the age of the YNB is suggested to be 85.7 Ma, indicating that the LTE began in the Early Santonian. The new ages provide a precise chronostratigraphic framework for climatic and geological events. Our new results imply that the beginning of the LTE, LAE and SWIE occurred almost simultaneously with short-term sea level rise, and probably had a close relationship with OAE3.

Solar Eruptive Activity at Mars' Orbit and its Potential Impacts

NASA Astrophysics Data System (ADS)

Luhmann, J. G.; Lee, C. O.; Curry, S.; Hara, T.; Halekas, J. S.; Li, Y.; Dong, C.; Ma, Y.; Lillis, R. J.; Dunn, P.; Gruesbeck, J.; Espley, J. R.; Brain, D.; Connerney, J. E. P.; Larson, D. E.; Jakosky, B. M.; Russell, C. T.

2016-12-01

While a number of studies exist relating to ICME signatures at Venus (PVO and VEX) and Mercury (Helios and Messenger), relatively few analyses exist for Mars' orbit. Nevertheless plasma and field signatures of ICMEs have been observed in the space near Mars by Phobos-2, Mars Global Surveyor (MGS), Mars Express (MEX), and now MAVEN. Of these, MAVEN is arguably best-instrumented, space weather-wise, to characterize such events. However, the weak solar activity over the past decade has limited what MAVEN, whose mission is to study Mars' atmospheric response to solar activity, including escape to space, has been able to observe. While the major October 1989 event, that produced at Earth one of the largest geomagnetic storms on record, occurred during the short Phobos-2 mission, and the notable series of Halloween 2003 storms occurred during the MGS mission, MAVEN has detected only moderate solar eruptive activity-related interplanetary disturbances at Mars. We compare the largest ICME observed by MAVEN with some of these other more extreme activity episodes for perspective. These comparisons hint at the potential impact of the magnitude of solar eruptions on what is experienced at Mars orbit, and on our ability to investigate planetary responses over the full range -when missions are at the mercy of what the solar cycle produces during their lifetimes.

Physiological roles of claudins in kidney tubule paracellular transport.

PubMed

Muto, Shigeaki

2017-01-01

The paracellular pathways in renal tubular epithelia such as the proximal tubules, which reabsorb the largest fraction of filtered solutes and water and are leaky epithelia, are important routes for transepithelial transport of solutes and water. Movement occurs passively via an extracellular route through the tight junction between cells. The characteristics of paracellular transport vary among different nephron segments with leaky or tighter epithelia. Claudins expressed at tight junctions form pores and barriers for paracellular transport. Claudins are from a multigene family, comprising at least 27 members in mammals. Multiple claudins are expressed at tight junctions of individual nephron segments in a nephron segment-specific manner. Over the last decade, there have been advances in our understanding of the structure and functions of claudins. This paper is a review of our current knowledge of claudins, with special emphasis on their physiological roles in proximal tubule paracellular solute and water transport. Copyright © 2017 the American Physiological Society.

Analyses of Deformation and Stress of Oil-free Scroll Compressor Scroll

NASA Astrophysics Data System (ADS)

Peng, Bin; Li, Yaohong; Zhao, Shenxian

2017-12-01

The solid model of orbiting and fixed scroll is created by the Solidworks The deformation and stress of scrolls under gas force, temperature field, inertia force and the coupling field are analyzed using the Ansys software. The deformation for different thickness and height scroll tooth is investigated. The laws of deformation and stress for scrolls are gotten. The research results indicate that the stress and deformation of orbiting scroll are mainly affected by the temperature field. The maximum deformation occurs in the tooth head of scroll wrap because of the largest gas forces and the highest temperature in the tooth head of scroll wrap. The maximum stress is located in the end of the tooth, and the maximum stress of the coupling field is not the sum of loads. The scroll tooth is higher, and the deformation is bigger. The scroll tooth is thicker, and the deformation is smaller.

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

Kim, Jae Wook; Artyukhin, Sergei; Mun, Eun Deok

In this paper, we report the discovery of a metamagnetic phase transition in a polar antiferromagnet Ni 3TeO 6 that occurs at 52 T. The new phase transition accompanies a colossal magnetoelectric effect, with a magnetic-field-induced polarization change of 0.3 μC/cm 2, a value that is 4 times larger than for the spin-flop transition at 9 T in the same material, and also comparable to the largest magnetically induced polarization changes observed to date. Via density-functional calculations we construct a full microscopic model that describes the data. We model the spin structures in all fields and clarify the physics behindmore » the 52 T transition. The high-field transition involves a competition between multiple different exchange interactions which drives the polarization change through the exchange-striction mechanism. Finally, the resultant spin structure is rather counterintuitive and complex, thus providing new insights on design principles for materials with strong magnetoelectric coupling.« less

Changes in polyphenolics during maturation of Java plum (Syzygium cumini Lam.).

PubMed

Lestario, Lydia Ninan; Howard, Luke R; Brownmiller, Cindi; Stebbins, Nathan B; Liyanage, Rohana; Lay, Jackson O

2017-10-01

Java plum (Syzygium cumini Lam.) is a rich source of polyphenolics with many purported health benefits, but the effect of maturation on polyphenolic content is unknown. Freeze-dried samples of Java plum from seven different maturity stages were analyzed for anthocyanin, flavonol, flavanonol and hydrolysable tannin composition by HPLC. Anthocyanins were first detected at the green-pink stage of maturity and increased throughout maturation with the largest increase occurring from the dark purple to black stages of maturation. Levels of gallotannins, ellagitannins, flavonols, gallic acid and ellagic acid were highest at early stages of maturation and decreased as the fruit ripened. For production of antioxidant-rich nutraceutical ingredients, fruit should be harvested immature to obtain extracts rich in hydrolysable tannins and flavonols. The exceptional anthocyanin content of black fruit may prove useful as a source of a natural colorant. Copyright © 2017 Elsevier Ltd. All rights reserved.

Metamorphosis in Teleosts

PubMed Central

McMenamin, Sarah K.; Parichy, David M.

2017-01-01

Teleosts are the largest and most diverse group of vertebrates, and many species undergo morphological, physiological, and behavioral transitions, “metamorphoses,” as they progress between morphologically divergent life stages. The larval metamorphosis that generally occurs as teleosts mature from larva to juvenile involves the loss of embryo-specific features, the development of new adult features, major remodeling of different organ systems, and changes in physical proportions and overall phenotype. Yet, in contrast to anuran amphibians, for example, teleost metamorphosis can entail morphological change that is either sudden and profound, or relatively gradual and subtle. Here, we review the definition of metamorphosis in teleosts, the diversity of teleost metamorphic strategies and the transitions they involve, and what is known of their underlying endocrine and genetic bases. We suggest that teleost metamorphosis offers an outstanding opportunity for integrating our understanding of endocrine mechanisms, cellular processes of morphogenesis and differentiation, and the evolution of diverse morphologies and life histories. PMID:23347518

The effects of increased CO[sub 2] on the competitive ability of Lupinus arboreus, a dominant nitrogen-fixing shrub

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

Wallace, A.M.

Plant responses to increased atmospheric CO[sub 2] have been shown to be both species-specific and dependent on other environmental factors, potentially changing competitive interactions and altering community structure. The competitive response of a dominant nitrogen-fixing shrub to an introduced annual (Bromus diandrus) and a native perennial grass (Bromus carinatus) was measured under ambient and high CO[sub 2] and two nitrogen levels. These species coexist in a generally nitrogen-limited coastal grassland reserve besieged with alien species. The relative competitive ability of the lupin increased with CO[sub 2] for all treatments, with the largest difference occurring at low nitrogen in competition withmore » the introduced annual. This study provides a global change perspective for those interested in conserving native Californian grassland species, as well as the first data on the competitive response of nitrogen-fixers to high CO[sub 2].« less

Outbreak of giardiasis associated with a community drinking-water source.

PubMed

Daly, E R; Roy, S J; Blaney, D D; Manning, J S; Hill, V R; Xiao, L; Stull, J W

2010-04-01

Giardiasis is a common waterborne gastrointestinal illness. In 2007, a community giardiasis outbreak occurred in New Hampshire, USA. We conducted a cohort study to identify risk factors for giardiasis, and stool and environmental samples were analysed. Consuming tap water was significantly associated with illness (risk ratio 4.7, 95% confidence interval 1.5-14.4). Drinking-water samples were coliform-contaminated and a suspect Giardia cyst was identified in a home water filter. One well was coliform-contaminated, and testing indicated that it was potentially under the influence of surface water. The well was located 12.5 m from a Giardia-contaminated brook, although the genotype differed from clinical specimens. Local water regulations require well placement at least 15 m from surface water. This outbreak, which caused illness in 31 persons, represents the largest community drinking-water-associated giardiasis outbreak in the USA in 10 years. Adherence to well placement regulations might have prevented this outbreak.

Conjunction Assessment Late-Notice High-Interest Event Investigation: Space Weather Aspects

NASA Technical Reports Server (NTRS)

Pachura, D.; Hejduk, M. D.

2016-01-01

Late-notice events usually driven by large changes in primary (protected) object or secondary object state. Main parameter to represent size of state change is component position difference divided by associated standard deviation (epsilon divided by sigma) from covariance. Investigation determined actual frequency of large state changes, in both individual and combined states. Compared them to theoretically expected frequencies. Found that large changes ( (epsilon divided by sigma) is greater than 3) in individual object states occur much more frequently than theory dictates. Effect is less pronounced in radial components and in events with probability of collision (Pc) greater than 1 (sup -5) (1e-5). Found combined state matched much closer to theoretical expectation, especially for radial and cross-track. In-track is expected to be the most vulnerable to modeling errors, so not surprising that non-compliance largest in this component.

Observational data needs for plasma phenomena

NASA Technical Reports Server (NTRS)

Niedner, M. B., Jr.

1981-01-01

Bright comets display a rich variety of interesting plasma phenomena which occur over an enormous range of spatial scales, and which require different observational techniques to be studied effectively. Wide-angle photography of high time resolution is probably the best method of studying the phenomenon of largest known scale: the plasma tail disconnection event (DE), which has been attributed to magnetic reconnection at interplanetary sector boundary crossings. These structures usually accelerate as they recede from the head region and observed velocities are typically in the range 50 V km/s. They are often visible for several days following the time of disconnection, and are sometimes seen out past 0.2 AU from the cometary head. The following areas pertaining to plasma phenomena in the ionoshere are addressed: the existence, size, and heliocentric distance variations of the contact surface, and the observational signatures of magnetic reconnection at sector boundary crossings.

Man made deltas

PubMed Central

Maselli, Vittorio; Trincardi, Fabio

2013-01-01

The review of geochronological and historical data documents that the largest southern European deltas formed almost synchronously during two short intervals of enhanced anthropic pressure on landscapes, respectively during the Roman Empire and the Little Ice Age. These growth phases, that occurred under contrasting climatic regimes, were both followed by generalized delta retreat, driven by two markedly different reasons: after the Romans, the fall of the population and new afforestation let soil erosion in river catchments return to natural background levels; since the industrial revolution, instead, flow regulation through river dams overkill a still increasing sediment production in catchment basins. In this second case, furthermore, the effect of a reduced sediment flux to the coasts is amplified by the sinking of modern deltas, due to land subsidence and sea level rise, that hampers delta outbuilding and increases the vulnerability of coastal zone to marine erosion and flooding. PMID:23722597

Sand waves at the mouth of San Francisco Bay, California

USGS Publications Warehouse

Barnard, Patrick L.; Hanes, Daniel M.; Kvitek, Rikk G.; Iampietro, Pat J.

2006-01-01

A multibeam bathymetric survey that produced unprecedented high resolution images of the mouth of San Francisco Bay was conducted in 2004 and 2005. The survey, performed over forty-four days by the Seafloor Mapping Lab at California State University, Monterey Bay, consisted of 1,138 track lines, 1.1 billion soundings, and covered an area of 154 km2 (60 mi2). The goals of this survey were to analyze sediment transport pathways at the mouth of San Francisco Bay and to calculate bathymetric change since the last survey was completed in 1956. The survey showed that significant bathymetric changes have occurred over the past 50 years. It also revealed that the study area contains sand waves that are among the largest and bedform morphologies that are among the most varied in the world. This set of five sheets shows views of the sand waves on the seafloor from different perspectives along with descriptive text.

Spatial variation in extreme winds predicts large wildfire locations in chaparral ecosystems

NASA Astrophysics Data System (ADS)

Moritz, Max A.; Moody, Tadashi J.; Krawchuk, Meg A.; Hughes, Mimi; Hall, Alex

2010-02-01

Fire plays a crucial role in many ecosystems, and a better understanding of different controls on fire activity is needed. Here we analyze spatial variation in fire danger during episodic wind events in coastal southern California, a densely populated Mediterranean-climate region. By reconstructing almost a decade of fire weather patterns through detailed simulations of Santa Ana winds, we produced the first high-resolution map of where these hot, dry winds are consistently most severe and which areas are relatively sheltered. We also analyzed over half a century of mapped fire history in chaparral ecosystems of the region, finding that our models successfully predict where the largest wildfires are most likely to occur. There is a surprising lack of information about extreme wind patterns worldwide, and more quantitative analyses of their spatial variation will be important for effective fire management and sustainable long-term urban development on fire-prone landscapes.

Supraglacial Lakes in the Percolation Zone of the Western Greenland Ice Sheet: Formation and Development using Operation IceBridge Snow Radar and ATM (2009-2014)

NASA Astrophysics Data System (ADS)

Chen, C.; Howat, I. M.; de la Peña, S.

2015-12-01

Surface meltwater lakes on the Greenland Ice Sheet have appeared at higher elevations, extending well into the percolation zone, under recent warming, with the largest expansion occurring in the western Greenland Ice Sheet. The conditions that allow lakes to form atop firn are poorly constrained, but the formation of new lakes imply changes in the permeability of the firn at high elevations, promoting meltwater runoff. We explore the formation and evolution of new surface lakes in this region above 1500 meters, using a combination of satellite imagery and repeat Snow (2-6.5 GHz) radar echograms and LIDAR measurements from NASA's Operation IceBridge of 2009-2014. We identify conditions for surface lake formation at their farthest inland extent and suggest behaviors of persistence and lake drainage are due to differences in regional ice dynamics.

Båth's law and its relation to the tectonic environment: A case study for earthquakes in Mexico

NASA Astrophysics Data System (ADS)

Rodríguez-Pérez, Q.; Zúñiga, F. R.

2016-09-01

We studied 66 mainshocks and their largest aftershocks in the Mexican subduction zone and in the Gulf of California with magnitudes in the range of 5.2 < Mw < 8.0 from 1932 to 2015. Three different types of earthquakes were analyzed: shallow thrust interplate, intermediate-depth inslab and transform strike-slip earthquakes (26, 19 and 21 events, respectively). We focus on observational aspects of the Båth's law. By studying the magnitude difference, energy ratios and energy partitioning of the mainshock-largest aftershock sequences, we analyze the physics of the mainshock-largest aftershock relationship (Båth's law). The partitioning of energy during a mainshock-aftershock sequence shows that about 96-97% of the energy dissipated in a sequence is associated with the mainshock and the rest is due to aftershocks. Our results for radiated seismic energy and energy-to-moment ratio are partially in agreement with worldwide studies supporting the observation of mechanism dependence of radiated seismic energy. The statistical tests indicate that the only significant difference is for shallow thrust and strike-slip events for these parameters. The statistical comparison of stress drop of shallow thrust versus that of inslab events shows a strongly significant difference with a confidence better than 99%. The comparison of stress drop of shallow thrust events with that of strike-slip events, also indicates a strongly significant difference. We see no dependence of stress drop with magnitude, which is strong evidence of earthquake self-similarity. We do not observe a systematic depth dependence of stress drop. The results also reveal differences in the earthquake rupture among the events. The magnitude difference between the mainshock and the largest aftershock for inslab events is larger than interplate and strike-slip events suggesting focal mechanism dependence of Båth's law. For the case of this parameter, only that for inslab and strike-slip events present a significant difference with 95% confidence.

Decreased diversion by doctor-shopping for a reformulated extended release oxycodone product (OxyContin).

PubMed

Chilcoat, Howard D; Coplan, Paul M; Harikrishnan, Venkatesh; Alexander, Louis

2016-08-01

Doctor-shopping (obtaining prescriptions from multiple prescribers/pharmacies) for opioid analgesics produces a supply for diversion and abuse, and represents a major public health issue. An open cohort study assessed changes in doctor-shopping in the U.S. for a brand extended release (ER) oxycodone product (OxyContin) and comparator opioids before (July, 2009 to June, 2010) versus after (January, 2011 to June, 2013) introduction of reformulated brand ER oxycodone with abuse-deterrent properties, using IMS LRx longitudinal data covering >150 million patients and 65% of retail U.S. prescriptions. After its reformulation, the rate of doctor-shopping decreased 50% (for 2+ prescribers/3+ pharmacies) for brand ER oxycodone, but not for comparators. The largest decreases in rates occurred among young adults (73%), those paying with cash (61%) and those receiving the highest available dose (62%), with a 90% decrease when stratifying by all three characteristics. The magnitude of doctor-shopping reductions increased with increasing number of prescribers/pharmacies (e.g., 75% reduction for ≥2 prescribers/≥4 pharmacies). The rate of doctor-shopping for brand ER oxycodone decreased substantially after its reformulation, which did not occur for other prescription opioids. The largest reductions in doctor-shopping occurred with characteristics associated with higher abuse risk such as youth, cash payment and high dose, and with more specific thresholds of doctor-shopping. A higher prescriber and/or pharmacy threshold also increased the magnitude of the decrease, suggesting that it better captured the effect of the reformulation on actual doctor-shoppers. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Local Residents Trained As ‘Influence Agents’ Most Effective In Persuading African Couples On HIV Counseling and Testing

PubMed Central

Lambdin, Barrot; Kanweka, William; Inambao, Mubiana; Mwananyanda, Lawrence; Shah, Heena; Linton, Sabriya; Wong, Frank; Luisi, Nicole; Tichacek, Amanda; Kalowa, James; Chomba, Elwyn; Allen, Susan

2011-01-01

Couples in sub-Saharan Africa are the largest group in the world at risk for HIV infection. Couples counseling and testing programs have been shown to reduce HIV transmission, but such programs remain rare in Africa. Before couples counseling and testing can become the norm, it is essential to increase demand for the services. We evaluated the effectiveness of several promotional strategies during a two -year program in Kitwe and Ndola, Zambia. The program attracted more than 7,600 couples through the use of radio broadcasts, billboards, and other strategies. The most effective recruiting technique was the use of local residents trained as “influence agents” to reach out to friends, neighbors, and others in their sphere of influence. Of the estimated 2.5 million new cases of HIV in adults and children in 2009, more than two-thirds occurred in sub-Saharan Africa.1 In Zambia, the prevalence of HIV among adults in urban and rural areas is estimated at 19 and 10 percent, respectively.2 Most HIV transmission in sub-Saharan Africa is heterosexual and occurs between cohabiting partners with discordant HIV test results3–5—that is, only one partner is HIV-positive. Thus, most new cases of HIV occur when someone infects his or her heterosexual partner. Sub-Saharan African couples with discordant HIV test results are the world’s largest risk group for HIV.6 Approximately 20 percent of Zambian couples have discordant HIV results, a rate consistent with estimates from Uganda, Rwanda, Tanzania, and Kenya.7–14 PMID:21821565

Sponge distribution across Davies Reef, Great Barrier Reef, relative to location, depth, and water movement

NASA Astrophysics Data System (ADS)

Wilkinson, Clive R.; Evans, Elizabeth

1989-06-01

Sponge populations were surveyed at different depths in three zones of Davies Reef, a large platform reef of the central Great Barrier Reef. Depth is the major discriminatory factor as few sponges are found within the first 10 m depth and maximal populations occur between 15 m and 30 m on fore-reef, lagoon and back-reef slopes. Reef location is another major factor, with the lagoon containing a significantly different sponge population to either the fore-reef or the back-reef slopes. Physical factors are considered to be the major influences behind these patterns. Physical turbulence is strongest within the first 10 m and apparently limits sponge growth within these shallow zones. Insufficient photosynthetic radiation limits the growth of the sponge population below 30 m depth as many of the species are phototrophic with a dependence on cyanobacterial symbionts for nutrition. Sponge populations on the outer (fore- and back-) reef slopes are comparable with each other but different from those on lagoon slopes where currents are reduced and fine sediment loads are higher. The largest populations occur on the back-reef slope where currents are stronger and there are possibly higher concentrations of organic nutrients originating from the more productive shallow parts of the reef. While there are correlations between sponge populations and environmental parameters, data are insufficient to enable more definitive conclusions to be drawn. Most sponge species are distributed widely over the reef, however, some are restricted to a few habitats and, hence, may be used to characterize those habitats.

Quantification of net annual C input in terrestrial ecosystems of the Italian Peninsula under different land-uses

USDA-ARS?s Scientific Manuscript database

Soil organic matter (SOM) is a very important compartment of the biosphere: it represents the largest dynamic carbon (C) pool where the C is stored for the longest time period. Root inputs, as exudates and root slush, represent a major, where not the largest, annual contribution to soil C input. Roo...

Summer temperature variability across four urban neighborhoods in Knoxville, Tennessee, USA

NASA Astrophysics Data System (ADS)

Ellis, Kelsey N.; Hathaway, Jon M.; Mason, Lisa Reyes; Howe, David A.; Epps, Thomas H.; Brown, Vincent M.

2017-02-01

The urban heat island (UHI) is a well-documented effect of urbanization on local climate, identified by higher temperatures compared to surrounding areas, especially at night and during the warm season. The details of a UHI are city-specific, and microclimates may even exist within a given city. Thus, investigating the spatiotemporal variability of a city's UHI is an ongoing and critical research need. We deploy ten weather stations across Knoxville, Tennessee, to analyze the city's UHI and its differential impacts across urban neighborhoods: two each in four neighborhoods, one in more dense tree cover and one in less dense tree cover, and one each in downtown Knoxville and Ijams Nature Center that serve as control locations. Three months of temperature data (beginning 2 July 2014) are analyzed using paired-sample t tests and a three-way analysis of variance. Major findings include the following: (1) Within a given neighborhood, tree cover helps negate daytime heat (resulting in up to 1.19 ∘C lower maximum temperature), but does not have as large of an influence on minimum temperature; (2) largest temperature differences between neighborhoods occur during the day (0.38-1.16 ∘C difference), but larger differences between neighborhoods and the downtown control occur at night (1.04-1.88 ∘C difference); (3) presiding weather (i.e., air mass type) has a significant, consistent impact on the temperature in a given city, and lacks the differential impacts found at a larger-scale in previous studies; (4) distance from city center does not impact temperature as much as land use factors. This is a preliminary step towards informing local planning with a scientific understanding of how mitigation strategies may help minimize the UHI and reduce the effects of extreme weather on public health and well-being.

A Global Phylogeny of Leafmining Ectoedemia Moths (Lepidoptera: Nepticulidae): Exploring Host Plant Family Shifts and Allopatry as Drivers of Speciation

PubMed Central

Doorenweerd, Camiel; van Nieukerken, Erik J.; Menken, Steph B. J.

2015-01-01

Background Host association patterns in Ectoedemia (Lepidoptera: Nepticulidae) are also encountered in other insect groups with intimate plant relationships, including a high degree of monophagy, a preference for ecologically dominant plant families (e.g. Fagaceae, Rosaceae, Salicaceae, and Betulaceae) and a tendency for related insect species to feed on related host plant species. The evolutionary processes underlying these patterns are only partly understood, we therefore assessed the role of allopatry and host plant family shifts in speciation within Ectoedemia. Methodology Six nuclear and mitochondrial DNA markers with a total aligned length of 3692 base pairs were used to infer phylogenetic relationships among 92 species belonging to the subgenus Ectoedemia of the genus Ectoedemia, representing a thorough taxon sampling with a global coverage. The results support monophyletic species groups that are congruent with published findings based on morphology. We used the obtained phylogeny to explore host plant family association and geographical distribution to investigate if host shifts and allopatry have been instrumental in the speciation of these leafmining insects. Significance We found that, even though most species within species groups commonly feed on plants from one family, shifts to a distantly related host family have occasionally occurred throughout the phylogeny and such shifts are most commonly observed towards Betulaceae. The largest radiations have occurred within species groups that feed on Fagaceae, Rosaceae, and Salicaceae. Most species are restricted to one of the seven global biogeographic regions, but within species groups representatives are commonly found in different biogeographic regions. Although we find general patterns with regard to host use and biogeography, there are differences between clades that suggest that different drivers of speciation, and perhaps drivers that we did not examine, have shaped diversity patterns in different clades. PMID:25785630

Different Patterns of the Urban Heat Island Intensity from Cluster Analysis

NASA Astrophysics Data System (ADS)

Silva, F. B.; Longo, K.

2014-12-01

This study analyzes the different variability patterns of the Urban Heat Island intensity (UHII) in the Metropolitan Area of Rio de Janeiro (MARJ), one of the largest urban agglomerations in Brazil. The UHII is defined as the difference in the surface air temperature between the urban/suburban and rural/vegetated areas. To choose one or more stations that represent those areas we used the technique of cluster analysis on the air temperature observations from 14 surface weather stations in the MARJ. The cluster analysis aims to classify objects based on their characteristics, gathering similar groups. The results show homogeneity patterns between air temperature observations, with 6 homogeneous groups being defined. Among those groups, one might be a natural choice for the representative urban area (Central station); one corresponds to suburban area (Afonsos station); and another group referred as rural area is compound of three stations (Ecologia, Santa Cruz and Xerém) that are located in vegetated regions. The arithmetic mean of temperature from the three rural stations is taken to represent the rural station temperature. The UHII is determined from these homogeneous groups. The first UHII is estimated from urban and rural temperature areas (Case 1), whilst the second UHII is obtained from suburban and rural temperature areas (Case 2). In Case 1, the maximum UHII occurs in two periods, one in the early morning and the other at night, while the minimum UHII occurs in the afternoon. In Case 2, the maximum UHII is observed during afternoon/night and the minimum during dawn/early morning. This study demonstrates that the stations choice reflects different UHII patterns, evidencing that distinct behaviors of this phenomenon can be identified.

Nitrous oxide emissions from intensive agricultural systems: Variations between crops and seasons, key driving variables, and mean emission factors

NASA Astrophysics Data System (ADS)

Dobbie, K. E.; McTaggart, I. P.; Smith, K. A.

1999-11-01

Emissions of nitrous oxide from intensively managed agricultural fields were measured over 3 years. Exponential increases in flux occurred with increasing soil water- filled pore space (WFPS) and temperature; increases in soil mineral N content due to fertilizer application also stimulated emissions. Fluxes were low when any of these variables was below a critical value. The largest fluxes occurred when WFPS values were very high (70-90%), indicating that denitrification was the major process responsible. The relationships with the driving variables showed strong similarities to those reported for very different environments: irrigated sugar cane crops, pastures, and forest in the tropics. Annual emissions varied widely (0.3-18.4 kg N2O-N ha-1). These variations were principally due to the degree of coincidence of fertilizer application and major rainfall events. It is concluded therefore that several years' data are required from any agricultural ecosystem in a variable climate to obtain a robust estimate of mean N2O fluxes. The emissions from small-grain cereals (winter wheat and spring barley) were consistently lower (0.2-0.7 kg N2O-N per 100 kg N applied) than from cut grassland (0.3-5.8 kg N2O- N per 100 kg N). Crops such as broccoli and potatoes gave emissions of the same order as those from the grassland. Although these differences between crop types are not apparent in general data comparisons, there may well be distinct regional differences in the relative and absolute emissions from different crops, due to local factors relating to soil type, weather patterns, and agricultural management practices. This will only be determined by more detailed comparative studies.

Evaluating the first Brazilian program of payments for environmental services: An approach for optimizing soil conservation using GIS

NASA Astrophysics Data System (ADS)

Zolin, C. A.; Folegatti, M. V.; Mingoti, R.; Paulino, J.; Sánchez-Román, R. M.; González, A. M.

2013-12-01

Brazil possesses one of the most important water assets in the world, however, the country experiences vast differences among its hydrographic regions. Although Brazil has the largest water reserves in the world, those reserves are not distributed according to the concentration of the population. In addition, the largest portions of these water reserves are not always located where the highest urban concentrations and demands occur, which causes serious problems in maintaining water supply within the country's most populous regions (Zolin et al. 2011). It has become evident that policies aimed at mitigating the growing water resources and water use conflicts in Brazil are crucial. The municipality of Extrema in Minas Gerais state in Brazil pioneered the first Brazilian municipal PES initiative (Conservador das Águas program), based on the relationship between forests and the benefits they provide. This study aimed to assess soil loss in the Posses sub-basin, where the Conservador das Águas program began. Additionally, we aimed to determine the potential that this PES initiative has for soil conservation, as well as to optimize the environmental services provided as a function of forest area size and location. In this sense, considering the prescribed conservation practices, land use situation, and soil cover in the Posses sub-basin, we analyzed the effectiveness of the Conservador das Águas program before and after implementation in relation to reduced soil loss under different land use and soil cover scenarios. We used a geographic information system (GIS) for spatializing and producing different information plans and the Revised Universal Soil Loss Equation (RUSLE) for estimating soil loss. As a result, we found that optimized soil conservation may be obtained by adopting pasture conservation practices. Additionally the expected average soil loss in the Posses sub-basin under conditions of land use and soil cover, before and after implementing the water conservation program, was 30.63 and 7.06 Mg ha-1 year-1, respectively.

Does Mexican Land Management Influence US Southwest Rainfall? Effects of Vegetation Seasonality and Land Use Change on Atmospheric Moisture Transport in the North American Monsoon

NASA Astrophysics Data System (ADS)

Bohn, T. J.; Vivoni, E. R.

2013-12-01

Southern Arizona and New Mexico receive 30-50% of their annual rainfall in the summer, as part of the North American Monsoon (NAM). Modeling studies suggest that 15-25% of this rainfall first falls on Mexican land, is transpired by vegetation, and subsequently is transported northward across the border to the US. The main source regions in Mexico lie in the subtropical scrub and tropical deciduous forests in the foothills of the Sierra Madre Occidental, in the states of Sinaloa and Sonora. A key characteristic of these natural ecosystems is their rapid greening at the onset of the monsoon, which maximizes the amount of moisture transpired from the soil into the atmosphere in the days immediately following rainfall. These ecosystems are under threat from a number of human activities, including expansion of rainfed and irrigated agriculture, deforestation for grazing activities and urbanization. These changes in land use result in dramatically different seasonality and magnitude of evapotranspiration. In this study, we examine the differences in spatial and temporal characteristics of evapotranspiration yielded by current and pre-industrial land cover. To this end, we employ the Variable Infiltration Capacity (VIC) land surface model at 1/16 degree resolution, driven by gridded meteorological observations and the MCD15A3 4-day MODIS LAI product, across the NAM region (Arizona, New Mexico, and northern Mexico). We compare the magnitude and timing of land-atmosphere fluxes given by both pre-industrial and current land cover/use, as well as the land cover under several possible alternative land use scenarios. We identify the regions where the largest changes in magnitude and timing of evapotranspiration have occurred, as well as the regions and land use changes that could produce the largest changes in future evapotranspiration under different scenarios. Finally, we explore the consequences these effects have for monsoon moisture transport.

Using the spatial distribution and lithology of ballistic blocks to interpret eruption sequence and dynamics: August 6 2012 Upper Te Maari eruption, New Zealand

NASA Astrophysics Data System (ADS)

Breard, E. C. P.; Lube, G.; Cronin, S. J.; Fitzgerald, R.; Kennedy, B.; Scheu, B.; Montanaro, C.; White, J. D. L.; Tost, M.; Procter, J. N.; Moebis, A.

2014-10-01

The ballistic ejection of blocks during explosive eruptions constitutes a major hazard near active volcanoes. Fields of ballistic clasts can provide important clues towards quantifying the energy, dynamics and directionality of explosive events, but detailed datasets are rare. During the 6 August 2012 hydrothermal eruption of Upper Te Maari (Tongariro), New Zealand, three explosions occurred in rapid succession within less than 20 s. The first two produced laterally-directed pyroclastic density currents (PDC), and the final vertical explosion generated an ash plume. Each of these explosions was associated with the ejection of ballistic blocks. We present detailed maps of the resulting 5.1 km2 block impact field and the distribution of the > 2200 impact craters with diameters > 2.5 m. There are two distinct regions of high crater concentration, where crater densities reach more than six times the average background density. These occur at distances of 500-700 m east and 1000-1350 west of a 430-m-long fissure that was created during the eruption. The high-density fields are characterized by a narrow radial spread of < 45° and are located along the proximal transport direction of the pyroclastic density currents. A provenance analysis of ballistic blocks allowed us to reconstruct two different eruptive vents for the explosions. The first two laterally-directed explosions were sourced from the fissure, while the third explosion occurred through the pre-existing Upper Te Maari Crater, generating a roughly axisymmetric shower of ballistics. Stratigraphic relationships between impact craters, PDC and fall deposits suggest that the ballistic blocks were initially coupled with the rapidly expanding gas-particle mixtures that produced the PDCs. Ballistic trajectory modeling, reproducing the lateral extent and main impact density pattern of the western impact field, allows estimation of the vertical expansion angle of the second and largest explosion. The calculations show that the largest proportion of the explosion energy was strongly focused as a narrow and extremely shallow (from - 3 to 15° from the horizontal) laterally expanding hydrothermal blast. The results presented here constitute an important data set for ballistic hazard assessment at Tongariro volcano and they can provide further clues towards better understanding highly energetic laterally directed volcanic explosions at similar hydrothermal fields.

Channel degradation and restoration of an Alpine river and related morphological changes

NASA Astrophysics Data System (ADS)

Campana, Daniela; Marchese, Enrico; Theule, Joshua I.; Comiti, Francesco

2014-09-01

River degradation and thus necessity for restoration are major issues worldwide. However, adequate methodologies to assess morphological variations linked to these actions and the morphological success of restoration interventions are still to be determined. The Ahr River (South Tyrol, Italian Alps) was characterized until the mid-twentieth century by an anabranching and meandering pattern, but starting from the 1960s it underwent intense channel degradation in terms of narrowing, incision, and floodplain disconnection. In the period 2003-2011, several reaches of the Ahr River were restored by widening and raising the channel bed. The planimetric changes that occurred historically in the Ahr River were determined by the interpretation of 10 maps and aerial photos covering the period 1820-2011. The estimation of the incision that occurred during the degradation phase was assessed by the difference in elevation between gravel surfaces, whereas the changes introduced by restoration interventions in two reaches were evaluated through the comparison of topographic cross sections surveyed in year 2000 and a high-resolution bathymetric LiDAR survey flown in late 2012. The MQI (Morphological Quality Index) was applied to different reaches in order to test how assessment methodologies respond to degradation and restoration actions. The combined analysis of planform and vertical changes indicates that gravel mining has been the largest pressure for the river, but a change in sediment/flow regimes probably led to the channel adjustments that occurred during the early twentieth century. The restoration measures have locally increased channel width, elevation, and morphometrical diversity compared to the unrestored reaches, as well as the morphological quality assessed by MQI. However, the extent of the modifications brought about by restoration works differs between the two restored reaches, pointing out the need for a quantitative analysis of the historical evolution of each river reach before designing and implementing restoration actions and to the necessity to monitor the subsequent morphological adjustments.

User's Guide for Monthly Vector Wind Profile Model

NASA Technical Reports Server (NTRS)

Adelfang, S. I.

1999-01-01

The background, theoretical concepts, and methodology for construction of vector wind profiles based on a statistical model are presented. The derived monthly vector wind profiles are to be applied by the launch vehicle design community for establishing realistic estimates of critical vehicle design parameter dispersions related to wind profile dispersions. During initial studies a number of months are used to establish the model profiles that produce the largest monthly dispersions of ascent vehicle aerodynamic load indicators. The largest monthly dispersions for wind, which occur during the winter high-wind months, are used for establishing the design reference dispersions for the aerodynamic load indicators. This document includes a description of the computational process for the vector wind model including specification of input data, parameter settings, and output data formats. Sample output data listings are provided to aid the user in the verification of test output.

Localized Rapid Warming of West Antarctic Subsurface Waters by Remote Winds

NASA Astrophysics Data System (ADS)

Griffies, S. M.; Spence, P.; Holmes, R.; Hogg, A. M.; Stewart, K. D.; England, M. H.

2017-12-01

The largest rates of Antarctic glacial ice mass loss are occurring tothe west of the Antarctica Peninsula in regions where warming ofsubsurface continental shelf waters is also largest. However, thephysical mechanisms responsible for this warming remain unknown. Herewe show how localized changes in coastal winds off East Antarctica canproduce significant subsurface temperature anomalies (>2C) around theentire continent. We demonstrate how coastal-trapped Kelvin wavescommunicate the wind disturbance around the Antarctic coastline. Thewarming is focused on the western flank of the Antarctic Peninsulabecause the anomalous circulation induced by the coastal-trapped wavesis intensified by the steep continental slope there, and because ofthe presence of pre-existing warm subsurface water. Thecoastal-trapped waves leads to an adjustment of the flow that shoalsisotherms and brings warm deep water upwards onto the continentalshelf and closer to the coast. This result demonstrates the uniquevulnerability of the West Antarctic region to a changing climate.

Inertio Gravity Waves in the Upper Mesosphere

NASA Technical Reports Server (NTRS)

Mayr, H. G.; Mengel, J. G.; Talaat, E. L.; Porter, H. S.; Chan, K. L.

2003-01-01

In the polar region of the upper mesosphere, horizontal wind oscillations have been observed with periods around 10 hours (Hernandez et al., 1992). Such waves are generated in our Numerical Spectral Model (NSM) and appear to be inertio gravity waves (IGW). Like the planetary waves (PW) in the model, the IGWs are generated by instabilities that arise in the mean zonal circulation. In addition to stationary waves for m = 0, eastward and westward propagating waves for m = 1 to 4 appear above 70 km that grow in magnitude up to about 110 km, having periods between 9 and 11 hours. The m = 1 westward propagating IGWs have the largest amplitudes, which can reach at the poles 30 m/s. Like PWs, the IGWs are intermittent but reveal systematic seasonal variations, with the largest amplitudes occurring generally in winter and spring. The IGWs propagate upward with a vertical wavelength of about 20 km.

Factors associated with buying and selling syringes among injection drug users in a setting of one of North America's largest syringe exchange programs.

PubMed

Kuyper, Laura M; Kerr, Thomas; Li, Kathy; Hogg, Robert S; Tyndall, Mark W; Montaner, Julio S G; Wood, Evan

2006-01-01

We performed analyses of syringe buying and syringe selling among Vancouver injection drug users, recruited from May 1996 and followed up between November 2002 and August 2003, in the context of one of North America's largest syringe exchange programs (SEPs). An interviewer-administered questionnaire, approximately 45 minutes in duration, was used to collect information regarding risk factors for HIV infection and sources of sterile syringes. Seventy participants (15%) reported syringe selling and 122 (26%) reported syringe buying. Syringe sellers were more likely to be female, reside in unstable housing, need help injecting, and have visited the SEP at least once weekly. Syringe buyers were more likely to need help injecting, have difficulty finding new syringes, have binged on drugs, and have visited the SEP at least once weekly. Syringe buying most frequently occurred when the SEP was closed.

The impact of Global Warming on global crop yields due to changes in pest pressure

NASA Astrophysics Data System (ADS)

Battisti, D. S.; Tewksbury, J. J.; Deutsch, C. A.

2011-12-01

A billion people currently lack reliable access to sufficient food and almost half of the calories feeding these people come from just three crops: rice, maize, wheat. Insect pests are among the largest factors affecting the yield of these three crops, but models assessing the effects of global warming on crops rarely consider changes in insect pest pressure on crop yields. We use well-established relationships between temperature and insect physiology to project climate-driven changes in pest pressure, defined as integrated population metabolism, for the three major crops. By the middle of this century, under most scenarios, insect pest pressure is projected to increase by more than 50% in temperate areas, while increases in tropical regions will be more modest. Yield relationships indicate that the largest increases in insect pest pressure are likely to occur in areas where yield is greatest, suggesting increased strain on global food markets.

Mineral deposits and metallogeny of Alaska

USGS Publications Warehouse

Goldfarb, Richard J.; Meighan, Corey J.; Meinert, Lawrence D.; Wilson, Frederic H.

2016-01-01

Alaska, the largest State within the United States, and mainly located north of latitude 60°, is an important part of the Circum-Arctic region. Alaska is a richly endowed region with a long and complex geologic history. The mining history is short by world standards but nevertheless there are a number of world-class deposits in Alaska, of which Red Dog and Pebble are among the largest of their respective types in the world. Alaska is a collection of geologic terranes or regions having distinct histories, most of which were tectonically assembled in the period from 400 million years to 50 million years ago (late Paleozoic through early Tertiary). They now occur as numerous fault-bounded blocks in the northernmost part of the North American Cordillera on the western margin of the Laurentian craton. These terranes are comprised of rocks ranging in age from Paleoproterozoic to Recent.

Analysis of the different source terms of natural radionuclides in a river affected by NORM (Naturally Occurring Radioactive Materials) activities.

PubMed

Baeza, A; Corbacho, J A; Guillén, J; Salas, A; Mora, J C

2011-05-01

The present work studied the radioacitivity impact of a coal-fired power plant (CFPP), a NORM industry, on the water of the Regallo river which the plant uses for cooling. Downstream, this river passes through an important irrigated farming area, and it is a tributary of the Ebro, one of Spain's largest rivers. Although no alteration of the (210)Po or (232)Th content was detected, the (234,238)U and (226)Ra contents of the water were significantly greater immediately below CFPP's discharge point. The (226)Ra concentration decreased progressively downstream from the discharge point, but the uranium content increased significantly again at two sampling points 8 km downstream from the CFPP's effluent. This suggested the presence of another, unexpected uranium source term different from the CFPP. The input from this second uranium source term was even greater than that from the CFPP. Different hypotheses were tested (a reservoir used for irrigation, remobilization from sediments, and the effect of fertilizers used in the area), with it finally being demonstrated that the source was the fertilizers used in the adjacent farming areas. Copyright © 2011 Elsevier Ltd. All rights reserved.

Cr(VI) removal on visible light active TiO2 nanotube arrays

NASA Astrophysics Data System (ADS)

Bashirom, Nurulhuda; Zulkifli, Muhammad Afiq; Subagja, Subagja; Kian, Tan Wai; Matsuda, Atsunori; Lockman, Zainovia

2018-05-01

Self-organized TiO2 nanotube (TNT) arrays were fabricated by anodic oxidation of titanium foil in three different fluoride electrolytes: ethylene glycol (EG), glycerol, and sodium sulfate (Na2SO4) at different voltage and anodization time. In these electrolytes, the TNTs were produced in ˜ 2 µm long, but at the different diameter. The size of inner diameter can be arranged from the largest to the smallest value in the order of glycerol > EG > Na2SO4. Crystallization of the TNTs by annealing was led to the formation of anatase-TiO2. The sample can be activated under natural sunlight for reduction of hexavalent chromium, Cr(VI) into trivalent chromium, Cr(III). The reduction was thought to occur via synergistic reactions between adsorption and photoreduction. The result demonstrates 100 % of Cr(VI) removal efficiency over the TNTs grown in EG after 120 min. Whereas, only 48 % and 45 % of Cr(VI) can be removed over the TNTs fabricated in glycerol and Na2SO4, respectively. High photocatalytic activity of the TNTs-EG can be attributed to high crystallinity of anatase phase, enhanced Cr(VI) adsorption, and less electron-hole recombination due to smoother tube walls.

Purification and Properties of an ATPase from Sulfolobus solfataricus

NASA Technical Reports Server (NTRS)

Hochstein, Lawrence I.; Stan-Lotter, Helga

1992-01-01

A sulfite-activated ATPase isolated from Sulfolobus solfataricus had a relative molecular mass of 370,000. It was composed of three subunits whose relative molecular masses were 63,000, 48,000, and 24,000. The enzyme was inhibited by the vacuolar ATPase inhibitors nitrate and N-ethylmaleimide; 4-chloro-7-nitrobenzo-furazan (NBD-Cl) was also inhibitory. N-Ethylmaleimide was predominately bound to the largest subunit while NBD-CL was bound to both subunits. ATPase activity was inhibited by low concentrations of p-chloromercuri-phenyl sulfonate and the inhibition was reversed by cysteine which suggested that thiol groups were essential for activity. While the ATPase from S. solfataricus shared several properties with the ATPase from S. acidocaldarius there were significant differences. The latter enzyme was activated by sulfate and chloride and was unaffected by N-ethylmaleimide, whereas the S. solfataricus ATPase was inhibited by these anions as well as N-ethyimaleimide. These differences as well as differences that occur in other vacuolar-like ATPases isolated from the methanogenic and the extremely halophilic bacteria suggest the existence of several types of archaeal ATPases, none of which have been demonstrated to synthesize ATP.

Sugars levels of four sugarcane genotypes in different stem portions during the maturation phase.

PubMed

Pereira, Laís F M; Ferreira, Vilma M; Oliveira, Nelson G DE; Sarmento, Pedro L V S; Endres, Laurício; Teodoro, Iêdo

2017-01-01

Maturation is a characteristic of sugarcane plant (Saccharum spp.) and even when grown under the same soil and climate conditions the varieties differ on the maturation curve. Thus, studies that allow establishing maturation curves of different sugarcane genotypes in the local soil and climate may indicate the proper harvesting period to ensure better quality of the raw material. This study aimed to analyze the levels of soluble sugars during the maturation phase and assess the technological and productivity indexes of four irrigated sugarcane genotypes in the region of Rio Largo, Alagoas. The experiment was conducted in randomized blocks in a 4 x 2 x 5 factorial: four genotypes (RB92579, RB98710, RB99395 and RB961003), two stem portions (internodes 1-4 and internodes 5-8) and five seasons (82, 49, 25, 13 and 3 days before harvesting), each treatment with three replications. Internodes 1-4 showed the highest levels of reducing sugars, while the largest accumulation of sucrose and total soluble solids occurred in internodes 5-8. RB99395 genotype showed more stability in the sugar levels during sugarcane maturation, which can indicate early maturation and high agricultural yield.

Age Differences in Age Perceptions and Developmental Transitions

PubMed Central

Chopik, William J.; Bremner, Ryan H.; Johnson, David J.; Giasson, Hannah L.

2018-01-01

Is 50 considered “old”? When do we stop being considered “young”? If individuals could choose to be any age, what would it be? In a sample of 502,548 internet respondents ranging in age from 10 to 89, we examined age differences in aging perceptions (e.g., how old do you feel?) and estimates of the timing of developmental transitions (e.g., when does someone become an older adult?). We found that older adults reported older perceptions of aging (e.g., choosing to be older, feeling older, being perceived as older), but that these perceptions were increasingly younger than their current age. The age to which individuals hope to live dramatically increased after age 40. We also found that older adults placed the age at which developmental transitions occurred later in the life course. This latter effect was stronger for transitions involving middle-age and older adulthood compared to transitions involving young adulthood. The current study constitutes the largest study to date of age differences in age perceptions and developmental timing estimates and yielded novel insights into how the aging process may affect judgments about the self and others. PMID:29449823

Cone pigment polymorphism in New World monkeys: are all pigments created equal?

PubMed

Rowe, Mickey P; Jacobs, Gerald H

2004-01-01

Most platyrrhine monkeys have a triallelic M/L opsin gene polymorphism that underlies significant individual variations in color vision. A survey of the frequencies of these polymorphic genes suggests that the three alleles occur with equal frequency among squirrel monkeys (subfamily Cebinae), but are not equally frequent in a number of species from the subfamily Callitrichinae. This departure from equal frequency in the Callitrichids should slightly increase the ratio of dichromats to trichromats in the population and significantly alter the relative representation of the three possible dichromatic and trichromatic phenotypes. A particular feature of the inequality is that it leads to a relative increase in the number of trichromats whose M/L pigments have the largest possible spectral separation. To assess whether these trichromatic phenotypes are equally well equipped to make relevant visual discriminations, psychophysical experiments were run on human observers. A technique involving the functional substitution of photopigments was used to simulate the discrimination between fruits among a background of leaves. The goal of the simulation was to reproduce in the cones of human observers excitations equivalent to those produced in monkey cones as the animals view fruit. Three different viewing conditions were examined involving variations in the relative luminances of fruit and leaves and the spectrum of the illuminant. In all cases, performance was best for simulated trichromacies including M/L pigments with the largest spectral separation. Thus, the inequality of opsin gene frequency in Callitrichid monkeys may reflect adaptive pressures.

Characterization of Resistance Gene Analogues (RGAs) in Apple (Malus × domestica Borkh.) and Their Evolutionary History of the Rosaceae Family

PubMed Central

Baldo, Angela; Righetti, Laura; Bailey, Aubrey; Fontana, Paolo; Velasco, Riccardo; Malnoy, Mickael

2014-01-01

The family of resistance gene analogues (RGAs) with a nucleotide-binding site (NBS) domain accounts for the largest number of disease resistance genes and is one of the largest gene families in plants. We have identified 868 RGAs in the genome of the apple (Malus × domestica Borkh.) cultivar ‘Golden Delicious’. This represents 1.51% of the total number of predicted genes for this cultivar. Several evolutionary features are pronounced in M. domestica, including a high fraction (80%) of RGAs occurring in clusters. This suggests frequent tandem duplication and ectopic translocation events. Of the identified RGAs, 56% are located preferentially on six chromosomes (Chr 2, 7, 8, 10, 11, and 15), and 25% are located on Chr 2. TIR-NBS and non-TIR-NBS classes of RGAs are primarily exclusive of different chromosomes, and 99% of non-TIR-NBS RGAs are located on Chr 11. A phylogenetic reconstruction was conducted to study the evolution of RGAs in the Rosaceae family. More than 1400 RGAs were identified in six species based on their NBS domain, and a neighbor-joining analysis was used to reconstruct the phylogenetic relationships among the protein sequences. Specific phylogenetic clades were found for RGAs of Malus, Fragaria, and Rosa, indicating genus-specific evolution of resistance genes. However, strikingly similar RGAs were shared in Malus, Pyrus, and Prunus, indicating high conservation of specific RGAs and suggesting a monophyletic origin of these three genera. PMID:24505246

Characterization of resistance gene analogues (RGAs) in apple (Malus × domestica Borkh.) and their evolutionary history of the Rosaceae family.

PubMed

Perazzolli, Michele; Malacarne, Giulia; Baldo, Angela; Righetti, Laura; Bailey, Aubrey; Fontana, Paolo; Velasco, Riccardo; Malnoy, Mickael

2014-01-01

The family of resistance gene analogues (RGAs) with a nucleotide-binding site (NBS) domain accounts for the largest number of disease resistance genes and is one of the largest gene families in plants. We have identified 868 RGAs in the genome of the apple (Malus × domestica Borkh.) cultivar 'Golden Delicious'. This represents 1.51% of the total number of predicted genes for this cultivar. Several evolutionary features are pronounced in M. domestica, including a high fraction (80%) of RGAs occurring in clusters. This suggests frequent tandem duplication and ectopic translocation events. Of the identified RGAs, 56% are located preferentially on six chromosomes (Chr 2, 7, 8, 10, 11, and 15), and 25% are located on Chr 2. TIR-NBS and non-TIR-NBS classes of RGAs are primarily exclusive of different chromosomes, and 99% of non-TIR-NBS RGAs are located on Chr 11. A phylogenetic reconstruction was conducted to study the evolution of RGAs in the Rosaceae family. More than 1400 RGAs were identified in six species based on their NBS domain, and a neighbor-joining analysis was used to reconstruct the phylogenetic relationships among the protein sequences. Specific phylogenetic clades were found for RGAs of Malus, Fragaria, and Rosa, indicating genus-specific evolution of resistance genes. However, strikingly similar RGAs were shared in Malus, Pyrus, and Prunus, indicating high conservation of specific RGAs and suggesting a monophyletic origin of these three genera.

Sizes of the Largest Possible Earthquakes in the Central and Eastern United States - Summary of a Workshop, September 8-9, 2008, Golden, Colorado

USGS Publications Warehouse

Wheeler, Russell L.

2009-01-01

Most probabilistic seismic-hazard assessments require an estimate of Mmax, the magnitude (M) of the largest earthquake that is thought possible within a specified area. In seismically active areas such as some plate boundaries, large earthquakes occur frequently enough that Mmax might have been observed directly during the historical period. In less active regions like most of the Central and Eastern United States and adjacent Canada, large earthquakes are much less frequent and generally Mmax must be estimated indirectly. The indirect-estimation methods are many, their results vary widely, and opinions differ as to which methods are valid. This lack of consensus about Mmax estimation increases the uncertainty of hazard assessments for planned nuclear power reactors and increases design and construction costs. Accordingly, the U.S. Geological Survey and the U.S. Nuclear Regulatory Commission held an open workshop on Mmax estimation in the Central and Eastern United States and adjacent Canada. The workshop was held on Monday and Tuesday, September 8 and 9, 2008, at the U.S. Geological Survey offices in Golden, Colorado. Thirty-five people attended. The workshop goals were to reach consensus on one or more of: (1) the relative merits of the various methods of Mmax estimation, (2) which methods are invalid, (3) which methods are promising but not yet ready for use, and (4) what research is needed to reach consensus on the values and relative importance of the individual estimation methods.

LTR Retrotransposons Contribute to Genomic Gigantism in Plethodontid Salamanders

PubMed Central

Sun, Cheng; Shepard, Donald B.; Chong, Rebecca A.; López Arriaza, José; Hall, Kathryn; Castoe, Todd A.; Feschotte, Cédric; Pollock, David D.; Mueller, Rachel Lockridge

2012-01-01

Among vertebrates, most of the largest genomes are found within the salamanders, a clade of amphibians that includes 613 species. Salamander genome sizes range from ∼14 to ∼120 Gb. Because genome size is correlated with nucleus and cell sizes, as well as other traits, morphological evolution in salamanders has been profoundly affected by genomic gigantism. However, the molecular mechanisms driving genomic expansion in this clade remain largely unknown. Here, we present the first comparative analysis of transposable element (TE) content in salamanders. Using high-throughput sequencing, we generated genomic shotgun data for six species from the Plethodontidae, the largest family of salamanders. We then developed a pipeline to mine TE sequences from shotgun data in taxa with limited genomic resources, such as salamanders. Our summaries of overall TE abundance and diversity for each species demonstrate that TEs make up a substantial portion of salamander genomes, and that all of the major known types of TEs are represented in salamanders. The most abundant TE superfamilies found in the genomes of our six focal species are similar, despite substantial variation in genome size. However, our results demonstrate a major difference between salamanders and other vertebrates: salamander genomes contain much larger amounts of long terminal repeat (LTR) retrotransposons, primarily Ty3/gypsy elements. Thus, the extreme increase in genome size that occurred in salamanders was likely accompanied by a shift in TE landscape. These results suggest that increased proliferation of LTR retrotransposons was a major molecular mechanism contributing to genomic expansion in salamanders. PMID:22200636

Mechanistic Study of Delamination Fracture in Al-Li Alloy C458 (2099)

NASA Technical Reports Server (NTRS)

Tayon, W. A.; Crooks, R. E.; Domack, M. S.; Wagner, J. A.; Beaudoin, A. J.; McDonald, R. J.

2009-01-01

Delamination fracture has limited the use of lightweight Al-Li alloys. In the present study, electron backscattered diffraction (EBSD) methods were used to characterize crack paths in Al-Li alloy C458 (2099). Secondary delamination cracks in fracture toughness samples showed a pronounced tendency for fracture between grain variants of the same deformation texture component. These results were analyzed by EBSD mapping methods and simulated with finite element analyses. Simulation procedures include a description of material anisotropy, local grain orientations, and fracture utilizing crystal plasticity and cohesive zone elements. Taylor factors computed for each grain orientation subjected to normal and shear stresses indicated that grain pairs with the largest Taylor factor differences were adjacent to boundaries that failed by delamination. Examination of matching delamination fracture surface pairs revealed pronounced slip bands in only one of the grains bordering the delamination. These results, along with EBSD studies, plasticity simulations, and Auger electron spectroscopy observations support a hypothesis that delamination fracture occurs due to poor slip accommodation along boundaries between grains with greatly differing plastic response.

Multiple scattered radiation emerging from Rayleigh and continental haze layers. I - Radiance, polarization, and neutral points

NASA Technical Reports Server (NTRS)

Kattawar, G. W.; Plass, G. N.; Hitzfelder, S. J.

1976-01-01

The matrix operator method was used to calculate the polarization of radiation scattered on layers of various optical thicknesses, with results compared for Rayleigh scattering and for scattering from a continental haze. In both cases, there are neutral points arising from the zeros of the polarization of single scattered photons at scattering angles of zero and 180 degrees. The angular position of these Rayleigh-like neutral points (RNP) in the sky shows appreciable variation with the optical thickness of the scattering layer for a Rayleigh phase matrix, but only a small variation for haze L phase matrix. Another type of neutral point exists for non-Rayleigh phase functions that is associated with the zeros of the polarization for single scattering which occurs between the end points of the curve. A comparison of radiances calculated from the complete theory of radiative transfer using Stokes vectors with those obtained from the scalar theory shows that differences of the order of 23% may be obtained for Rayleigh scattering, while the largest difference found for a haze L phase function was of the order of 0.1%.

How to test validity in orthodontic research: a mixed dentition analysis example.

PubMed

Donatelli, Richard E; Lee, Shin-Jae

2015-02-01

The data used to test the validity of a prediction method should be different from the data used to generate the prediction model. In this study, we explored whether an independent data set is mandatory for testing the validity of a new prediction method and how validity can be tested without independent new data. Several validation methods were compared in an example using the data from a mixed dentition analysis with a regression model. The validation errors of real mixed dentition analysis data and simulation data were analyzed for increasingly large data sets. The validation results of both the real and the simulation studies demonstrated that the leave-1-out cross-validation method had the smallest errors. The largest errors occurred in the traditional simple validation method. The differences between the validation methods diminished as the sample size increased. The leave-1-out cross-validation method seems to be an optimal validation method for improving the prediction accuracy in a data set with limited sample sizes. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

HIV reservoirs: the new frontier.

PubMed

Iglesias-Ussel, Maria D; Romerio, Fabio

2011-01-01

Current antiretroviral therapies suppress viremia to very low levels, but are ineffective in eliminating reservoirs of persistent HIV infection. Efforts toward the development of therapies aimed at HIV reservoirs are complicated by the evidence that HIV establishes persistent productive and nonproductive infection in a number of cell types and through a variety of mechanisms. Moreover, immunologically privileged sites such as the brain also act as HIV sanctuaries. To facilitate the advancement of our knowledge in this new area of research, in vitro models of HIV persistence in different cellular reservoirs have been developed, particularly in CD4+ T-cells that represent the largest pool of persistently infected cells in the body. Whereas each model presents clear advantages, they all share one common limitation: they are systems attempting to recapitulate extremely complex virus-cell interactions occurring in vivo, which we know very little about. Potentially conflicting results arising from different models may be difficult to interpret without validation with clinical samples. Addressing these issues, among others, merits careful consideration for the identification of valid targets and the design of effective strategies for therapy, which may increase the success of efforts toward HIV eradication.

The influence of LED lighting on task accuracy: time of day, gender and myopia effects

NASA Astrophysics Data System (ADS)

Rao, Feng; Chan, A. H. S.; Zhu, Xi-Fang

2017-07-01

In this research, task errors were obtained during performance of a marker location task in which the markers were shown on a computer screen under nine LED lighting conditions; three illuminances (100, 300 and 500 lx) and three color temperatures (3000, 4500 and 6500 K). A total of 47 students participated voluntarily in these tasks. The results showed that task errors in the morning were small and nearly constant across the nine lighting conditions. However in the afternoon, the task errors were significantly larger and varied across lighting conditions. The largest errors for the afternoon session occurred when the color temperature was 4500 K and illuminance 500 lx. There were significant differences between task errors in the morning and afternoon sessions. No significant difference between females and males was found. Task errors for high myopia students were significantly larger than for the low myopia students under the same lighting conditions. In summary, the influence of LED lighting on task accuracy during office hours was not gender dependent, but was time of day and myopia dependent.

Labial and vaginal blood volume responses to visual and tactile stimuli.

PubMed

Henson, D E; Rubin, H B; Henson, C

1982-02-01

Five women volunteers participated in two experimental sessions designed to evaluate the response patterns of two objective psychophysiological measure of women's sexual arousal to different methods (and intensities) of sexual stimulation (i.e., an erotic film and manual self-stimulation). A vaginal photoplethysmograph was used to measure vaginal blood volume response and a labial thermistor-clip was used to measure temperature changes of one of the minor labia. Both measures usually covaried in a highly significant manner during both types of stimulation, with the largest responses typically being evoked by the physical stimulation. The response patterns for the two measures were also similar following both methods of stimulation if the woman did not experience orgasm; both measures decreased to some extent after the stimulation ended but usually remained well above the prestimulatory baseline. Orgasm, however, affected the two genital measures differently. The vaginal blood volume measure decreased dramatically during the reported orgasm, possibly because of vaginal contractions, and then increased to at least the preorgasmic level that occurred during the stimulation. The labial measure did not change during the reported orgasm but decreased relatively rapidly soon after.

Reorientation Timescales and Pattern Dynamics for Titan's Dunes: Does the Tail Wag the Dog or the Dragon?

NASA Astrophysics Data System (ADS)

Hayes, A. G.; Ewing, R. C.; Cassini Radar Science Team, T.

2011-12-01

Fields of bedform patterns persist across many orders of magnitude, from cm-scale sub-aqueous current ripples to km-scale aeolian dunes, and form with surprisingly little difference in expression despite a range of formative environments. Because of the remarkable similarity between and among patterns, extracting information about climate and environment from these patterns is a challenge. For example, crest orientation is not diagnostic of a particular flow regime; similar patterns form under many different flow configurations. On Titan, these challenges have played out with many attempts to reconcile dune-field patterns with modeled and expected wind regimes. We propose that thinking about the change in dune orientation, rather than the orientation itself, can provide new insights on the long-term stability of the dune-field patterns and the formative wind regime. In this work, we apply the re-orientation model presented by Werner and Kocurek [Geology, 1997] to the equatorial dune fields of Titan. We measure variations in pattern parameters (crest spacing, crest length and defect density, which is the number of defect pairs per total crest length) both within and between Titan's dune fields to describe pattern maturity and identify areas where changes in dune orientation are likely to occur (or may already be occurring). Measured defect densities are similar to Earth's largest linear dune fields, such as the Namib Sand Sea and the Simpson Desert. We use measured defect densities in the Werner and Kocurek model to estimate crestline reorientation rates. We find reorientation timescales varying from ten to a hundred thousand times the average migration timescale (time to migrate a bedform one meter, ~1 Titan year according to Tokano (Aeolian Research, 2010)). Well organized patterns have the longest reorientation time scales (~10^5 migration timescales), while the topographically or spatially isolated patches of dunes show the shortest reorientation times (~10^3 migration timescales). In addition, comparisons between spacing and defect density of Titan's dunes and some of the largest fields observed on Earth and Mars reveal that dune patterns on all three planets are geometrically similar, suggesting that growth and organization share common pattern dynamics. Our results suggest that Titan's dunes may react to gross bedform transport averaged over orbital timescales, relaxing the requirement that a single modern wind regime is required to produce the observed pattern.

Dynamics of the Wulong landslide revealed by broadband seismic records

NASA Astrophysics Data System (ADS)

Li, Zhengyuan; Huang, Xinghui; Xu, Qiang; Yu, Dan; Fan, Junyi; Qiao, Xuejun

2017-02-01

The catastrophic Wulong landslide occurred at 14:51 (Beijing time, UTC+8) on 5 June 2009, in Wulong Prefecture, Southwest China. This rockslide occurred in a complex topographic environment. Seismic signals generated by this event were recorded by the seismic network deployed in the surrounding area, and long-period signals were extracted from 8 broadband seismic stations within 250 km to obtain source time functions by inversion. The location of this event was simultaneously acquired using a stepwise refined grid search approach, with an error of 2.2 km. The estimated source time functions reveal that, according to the movement parameters, this landslide could be divided into three stages with different movement directions, velocities, and increasing inertial forces. The sliding mass moved northward, northeastward and northward in the three stages, with average velocities of 6.5, 20.3, and 13.8 m/s, respectively. The maximum movement velocity of the mass reached 35 m/s before the end of the second stage. The basal friction coefficients were relatively small in the first stage and gradually increasing; large in the second stage, accompanied by the largest variability; and oscillating and gradually decreasing to a stable value, in the third stage. Analysis shows that the movement characteristics of these three stages are consistent with the topography of the sliding zone, corresponding to the northward initiation, eastward sliding after being stopped by the west wall, and northward debris flowing after collision with the east slope of the Tiejianggou valley. The maximum movement velocity of the sliding mass results from the largest height difference of the west slope of the Tiejianggou valley. The basal friction coefficients of the three stages represent the thin weak layer in the source zone, the dramatically varying topography of the west slope of the Tiejianggou valley, and characteristics of the debris flow along the Tiejianggou valley. Based on the above results, it is recognized that the inverted source time functions are consistent with the topography of the sliding zone. Special geological and topographic conditions can have a focusing effect on landslides and are key factors in inducing the major disasters, which may follow from them. This landslide was of an unusual nature, and it will be worthwhile to pursue research into its dynamic characteristics more deeply.[Figure not available: see fulltext.

Potential Analysis of Rainfall-induced Sediment Disaster

NASA Astrophysics Data System (ADS)

Chen, Jing-Wen; Chen, Yie-Ruey; Hsieh, Shun-Chieh; Tsai, Kuang-Jung; Chue, Yung-Sheng

2014-05-01

Most of the mountain regions in Taiwan are sedimentary and metamorphic rocks which are fragile and highly weathered. Severe erosion occurs due to intensive rainfall and rapid flow, the erosion is even worsen by frequent earthquakes and severely affects the stability of hillsides. Rivers are short and steep in Taiwan with large runoff differences in wet and dry seasons. Discharges respond rapidly with rainfall intensity and flood flows usually carry large amount of sediment. Because of the highly growth in economics and social change, the development in the slope land is inevitable in Taiwan. However, sediment disasters occur frequently in high and precipitous region during typhoon. To make the execution of the regulation of slope land development more efficiency, construction of evaluation model for sediment potential is very important. In this study, the Genetic Adaptive Neural Network (GANN) was implemented in texture analysis techniques for the classification of satellite images of research region before and after typhoon or extreme rainfall and to obtain surface information and hazard log data. By using GANN weight analysis, factors, levels and probabilities of disaster of the research areas are presented. Then, through geographic information system the disaster potential map is plotted to distinguish high potential regions from low potential regions. Finally, the evaluation processes for sediment disaster after rainfall due to slope land use are established. In this research, the automatic image classification and evaluation modules for sediment disaster after rainfall due to slope land disturbance and natural environment are established in MATLAB to avoid complexity and time of computation. After implementation of texture analysis techniques, the results show that the values of overall accuracy and coefficient of agreement of the time-saving image classification for different time periods are at intermediate-high level and above. The results of GANN show that the weight of building density is the largest in all slope land disturbance factors, followed by road density, orchard density, baren land density, vegetation density, and farmland density. The weight of geology is the largest in all natural environment factors, followed by slope roughness, slope, and elevation. Overlaying the locations of large sediment disaster in the past on the potential map predicted by GANN, we found that most damage areas were in the region with medium-high or high potential of landslide. Therefore, the proposed potential model of sediment disaster can be used in practice.

Prevalence and Functioning of Children with Cerebral Palsy in Four Areas of the United States in 2006: A Report from the Autism and Developmental Disabilities Monitoring Network

ERIC Educational Resources Information Center

Kirby, Russell S.; Wingate, Martha S.; Van Naarden Braun, Kim; Doernberg, Nancy S.; Arneson, Carrie L.; Benedict, Ruth E.; Mulvihill, Beverly; Durkin, Maureen S.; Fitzgerald, Robert T.; Maenner, Matthew J.; Patz, Jean A.; Yeargin-Allsopp, Marshalyn

2011-01-01

Aim: To estimate the prevalence of cerebral palsy (CP) and the frequency of co-occurring developmental disabilities (DDs), gross motor function (GMF), and walking ability using the largest surveillance DD database in the US. Methods: We conducted population-based surveillance of 8-year-old children in 2006 (N = 142,338), in areas of Alabama,…

An overview of University of Alaska Anchorage, ENRI research on the spruce bark beetle infestation, Kenai Peninsula, Alaska, 1997-2002

Treesearch

Vernon J. LaBau

2006-01-01

In the mid 1990s, one of the largest bark beetle infestations seen anywhere in the world occurred on the Kenai Peninsula of Alaska. In one year, the infestation affected over one million acres of spruce in Alaska. This paper presents a coalescence of several aspects of study on the problem, including tree inventory and mortality, regeneration, understory response, a...

An ecological assessment of land use impacts in small watersheds of the Chesapeake Bay

Treesearch

Andrew Leight; John Jacobs; Lonnie Gonsalves; Gretchen Messick; Shawn McLaughlin; Jay Lewis; Juliana Brush; Eric Daniels; Matthew Rhodes; Lewis Collier; Robert Wood

2016-01-01

The Chesapeake Bay, the nation’s largest estuary, remains in relatively poor condition despite intensive public and scientific attention. In order to better understand the stressors and impacts occurring in the Bay as a result of land management decisions we conducted an assessment of both habitat condition and organismal response in three small watersheds of the upper...

The Paracel Islands and U.S. Interests and Approaches in the South China Sea

DTIC Science & Technology

2014-06-01

Billiton, and Hong Kong-owned and Canada-based Husky Energy. Initial Chinese offshore exploitation occurred in the nearby Pearl River Mouth Basin and...possibility for marine-based tourism in the region, and in April 2013, China authorized tourists to visit the Paracels.40 China, which currently controls...the entire Paracel archipelago, is expanding tourism , fishing, and the military garrison on Woody Island, the archipelago’s largest feature, as the

Great Barrier Reef, Queensland, Australia

NASA Technical Reports Server (NTRS)

1990-01-01

This detailed view of the Great Barrier Reef, Queensland, Australia (19.5S, 149.5E) shows several small patch reefs within the overall reef system. The Great Barrier Reef, largest in the world, comprises thousands of individual reefs of great variety and are closely monitored by marine ecologists. These reefs are about 6000 years old and sit on top of much older reefs. The most rapid coral growth occurs on the landward side of the reefs.

Relating Topological Determinants of Complex Networks to Their Spectral Properties: Structural and Dynamical Effects

NASA Astrophysics Data System (ADS)

Castellano, Claudio; Pastor-Satorras, Romualdo

2017-10-01

The largest eigenvalue of a network's adjacency matrix and its associated principal eigenvector are key elements for determining the topological structure and the properties of dynamical processes mediated by it. We present a physically grounded expression relating the value of the largest eigenvalue of a given network to the largest eigenvalue of two network subgraphs, considered as isolated: the hub with its immediate neighbors and the densely connected set of nodes with maximum K -core index. We validate this formula by showing that it predicts, with good accuracy, the largest eigenvalue of a large set of synthetic and real-world topologies. We also present evidence of the consequences of these findings for broad classes of dynamics taking place on the networks. As a by-product, we reveal that the spectral properties of heterogeneous networks built according to the linear preferential attachment model are qualitatively different from those of their static counterparts.

Overview of MPLNET Version 3 Cloud Detection

NASA Technical Reports Server (NTRS)

Lewis, Jasper R.; Campbell, James; Welton, Ellsworth J.; Stewart, Sebastian A.; Haftings, Phillip

2016-01-01

The National Aeronautics and Space Administration Micro Pulse Lidar Network, version 3, cloud detection algorithm is described and differences relative to the previous version are highlighted. Clouds are identified from normalized level 1 signal profiles using two complementary methods. The first method considers vertical signal derivatives for detecting low-level clouds. The second method, which detects high-level clouds like cirrus, is based on signal uncertainties necessitated by the relatively low signal-to-noise ratio exhibited in the upper troposphere by eye-safe network instruments, especially during daytime. Furthermore, a multitemporal averaging scheme is used to improve cloud detection under conditions of a weak signal-to-noise ratio. Diurnal and seasonal cycles of cloud occurrence frequency based on one year of measurements at the Goddard Space Flight Center (Greenbelt, Maryland) site are compared for the new and previous versions. The largest differences, and perceived improvement, in detection occurs for high clouds (above 5 km, above MSL), which increase in occurrence by over 5%. There is also an increase in the detection of multilayered cloud profiles from 9% to 19%. Macrophysical properties and estimates of cloud optical depth are presented for a transparent cirrus dataset. However, the limit to which the cirrus cloud optical depth could be reliably estimated occurs between 0.5 and 0.8. A comparison using collocated CALIPSO measurements at the Goddard Space Flight Center and Singapore Micro Pulse Lidar Network (MPLNET) sites indicates improvements in cloud occurrence frequencies and layer heights.

Direction selectivity in the larval zebrafish tectum is mediated by asymmetric inhibition.

PubMed

Grama, Abhinav; Engert, Florian

2012-01-01

The extraction of the direction of motion is an important computation performed by many sensory systems and in particular, the mechanism by which direction-selective retinal ganglion cells (DS-RGCs) in the retina acquire their selective properties, has been studied extensively. However, whether DS-RGCs simply relay this information to downstream areas or whether additional and potentially de novo processing occurs in these recipient structures is a matter of great interest. Neurons in the larval zebrafish tectum, the largest retino-recipent area in this animal, show direction-selective (DS) responses to moving visual stimuli but how these properties are acquired is still unknown. In order to study this, we first used two-photon calcium imaging to classify the population responses of tectal cells to bars moving at different speeds and in different directions. Subsequently, we performed in vivo whole cell electrophysiology on these DS tectal neurons and we found that their inhibitory inputs were strongly biased toward the null direction of motion, whereas the excitatory inputs showed little selectivity. In addition, we found that excitatory currents evoked by a stimulus moving in the preferred direction occurred before the inhibitory currents whereas a stimulus moving in the null direction evoked currents in the reverse temporal order. The membrane potential modulations resulting from these currents were enhanced by the spike generation mechanism to generate amplified direction selectivity in the spike output. Thus, our results implicate a local inhibitory circuit in generating direction selectivity in tectal neurons.

Direction selectivity in the larval zebrafish tectum is mediated by asymmetric inhibition

PubMed Central

Grama, Abhinav; Engert, Florian

2012-01-01

The extraction of the direction of motion is an important computation performed by many sensory systems and in particular, the mechanism by which direction-selective retinal ganglion cells (DS-RGCs) in the retina acquire their selective properties, has been studied extensively. However, whether DS-RGCs simply relay this information to downstream areas or whether additional and potentially de novo processing occurs in these recipient structures is a matter of great interest. Neurons in the larval zebrafish tectum, the largest retino-recipent area in this animal, show direction-selective (DS) responses to moving visual stimuli but how these properties are acquired is still unknown. In order to study this, we first used two-photon calcium imaging to classify the population responses of tectal cells to bars moving at different speeds and in different directions. Subsequently, we performed in vivo whole cell electrophysiology on these DS tectal neurons and we found that their inhibitory inputs were strongly biased toward the null direction of motion, whereas the excitatory inputs showed little selectivity. In addition, we found that excitatory currents evoked by a stimulus moving in the preferred direction occurred before the inhibitory currents whereas a stimulus moving in the null direction evoked currents in the reverse temporal order. The membrane potential modulations resulting from these currents were enhanced by the spike generation mechanism to generate amplified direction selectivity in the spike output. Thus, our results implicate a local inhibitory circuit in generating direction selectivity in tectal neurons. PMID:22969706

Analysis of dust samples collected from spent nuclear fuel interim storage containers at Hope Creek, Delaware, and Diablo Canyon, California

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

Bryan, Charles R.; Enos, David George

2014-07-01

Potentially corrosive environments may form on the surface of spent nuclear fuel dry storage canisters by deliquescence of deposited dusts. To assess this, samples of dust were collected from in-service dry storage canisters at two near-marine sites, the Hope Creek and Diablo Canyon storage installations, and have been characterized with respect to mineralogy, chemistry, and texture. At both sites, terrestrially-derived silicate minerals, including quartz, feldspars, micas, and clays, comprise the largest fraction of the dust. Also significant at both sites were particles of iron and iron-chromium metal and oxides generated by the manufacturing process. Soluble salt phases were minor componentmore » of the Hope Creek dusts, and were compositionally similar to inland salt aerosols, rich in calcium, sulfate, and nitrate. At Diablo Canyon, however, sea-salt aerosols, occurring as aggregates of NaCl and Mg-sulfate, were a major component of the dust samples. The seasalt aerosols commonly occurred as hollow spheres, which may have formed by evaporation of suspended aerosol seawater droplets, possibly while rising through the heated annulus between the canister and the overpack. The differences in salt composition and abundance for the two sites are attributed to differences in proximity to the open ocean and wave action. The Diablo Canyon facility is on the shores of the Pacific Ocean, while the Hope Creek facility is on the shores of the Delaware River, several miles from the open ocean.« less

Biodiversity of Costa Rican salamanders: Implications of high levels of genetic differentiation and phylogeographic structure for species formation

PubMed Central

García-París, Mario; Good, David A.; Parra-Olea, Gabriela; Wake, David B.

2000-01-01

Although salamanders are characteristic amphibians in Holarctic temperate habitats, in tropical regions they have diversified evolutionarily only in tropical America. An adaptive radiation centered in Middle America occurred late in the history of a single clade, the supergenus Bolitoglossa (Plethodontidae), and large numbers of species now occur in diverse habitats. Sublineages within this clade decrease in number from the northern to southern parts of Middle America, and in Costa Rica, there are but three. Despite this phylogenetic constraint, Costa Rica has many species; the number of salamander species on one local elevational transect in the Cordillera de Talamanca may be the largest for any such transect in the world. Extraordinary variation in sequences of the mitochondrial gene cytochrome b within a clade of the genus Bolitoglossa in Costa Rica reveals strong phylogeographic structure within a single species, Bolitoglossa pesrubra. Allozymic variation in 19 proteins reveals a pattern largely concordant with the mitochondrial DNA phylogeography. More species exist than are currently recognized. Diversification occurs in restricted geographic areas and involves sharp geographic and elevational differentiation and zonation. In their degree of genetic differentiation at a local scale, these species of the deep tropics exceed the known variation of extratropical salamanders, which also differ in being less restricted in elevational range. Salamanders display “tropicality” in that although speciose, they are usually local in distribution and rare. They display strong ecological and physiological differentiation that may contribute importantly to morphological divergence and species formation. PMID:10677512

Three-dimensional P-wave velocity structure and precise earthquake relocation at Great Sitkin Volcano, Alaska

USGS Publications Warehouse

Pesicek, Jeremy; Thurber, Clifford H.; DeShon, Heather R.; Prejean, Stephanie G.; Zhang, Haijiang

2008-01-01

Waveform cross-correlation with bispectrum verification is combined with double-difference tomography to increase the precision of earthquake locations and constrain regional 3D P-wave velocity heterogeneity at Great Sitkin volcano, Alaska. From 1999 through 2005, the Alaska Volcano Observatory (AVO) recorded ∼1700 earthquakes in the vicinity of Great Sitkin, including two ML 4.3 earthquakes that are among the largest events in the AVO catalog. The majority of earthquakes occurred during 2002 and formed two temporally and spatially separate event sequences. The first sequence began on 17 March 2002 and was centered ∼20 km west of the volcano. The second sequence occurred on the southeast flank of Great Sitkin and began 28 May 2002. It was preceded by two episodes of volcanic tremor. Earthquake relocations of this activity on the southeast flank define a vertical planar feature oriented radially from the summit and in the direction of the assumed regional maximum compressive stress due to convergence along the Alaska subduction zone. This swarm may have been caused or accompanied by the emplacement of a dike. Relocations of the mainshock–aftershock sequence occurring west of Great Sitkin are consistent with rupture on a strike-slip fault. Tomographic images support the presence of a vertically dipping fault striking parallel to the direction of convergence in this region. The remaining catalog hypocenters relocate along discrete features beneath the volcano summit; here, low P-wave velocities possibly indicate the presence of magma beneath the volcano.

Waveform Classification of the 2016 Gyeongju Earthquake Sequence Using Hierarchical Clustering

NASA Astrophysics Data System (ADS)

Shin, J. S.; Son, M.; Cho, C.

2017-12-01

The 2016 Gyeongju earthquakes, including the ML 5.8 earthquake of September 12, 2016 ccurred around the Yangsan Fault System, which is the most prominent set of lineaments on the Korean Peninsula. The main event is the largest earthquake recorded since instrumental recording began in South Korea We analysed the waveforms of earthquake sequence to better understand the seismicity around this fault system. We defined groups of relocated hypocenters using hierarchical clustering based on waveform similarity. The 2016 Gyeongju events are classified into three major groups: Group A with 185 events, Group B with 134 events, and Group C with 45 events. The waveform similarity of each group was confirmed by the matrix of correlation coefficients. The three groups of waveforms wereare identified in space: the events of Group A occurred at shallower depths than those of Group B, while those of Group C occurred at intermediate depths at the north side. The eight major events occurred in the area including Group A and Group B, whereas the area of Group C produceds no major events. Therefore, the area of Group C couldcan be excluded in considering a major asperity for the Gyeongju earthquakes. Earthquakes that are close together spatially with similar rupture mechanisms produce similar waveforms at the same common station. Thus, the hypocenters classified from the three groups of waveforms, based on waveform similarity imply that the inferred fault plane contains three zones locked under slightly different conditions.

QBO/solar modulation of the boreal winter Madden-Julian oscillation: A prediction for the coming solar minimum

NASA Astrophysics Data System (ADS)

Hood, Lon L.

2017-04-01

The Madden-Julian oscillation (MJO), also known as the 30-60 day oscillation, is the strongest of the intraseasonal climate oscillations in the tropics and has significant derivative effects on extratropical circulation and intraseasonal climate. It has recently been shown that the stratospheric quasi-biennial oscillation (QBO) modulates the amplitude of the boreal winter MJO such that MJO amplitudes are larger on average during the easterly phase (QBOE) than during the westerly phase (QBOW). A major possible mechanism is the decrease in static stability in the lowermost stratosphere under QBOE conditions resulting from relative upwelling associated with the QBO-induced meridional circulation. Here evidence is presented that tropical upwelling changes related to the 11 year solar cycle also modulate the boreal winter MJO. Based on 37.3 years of MJO amplitude data, the largest amplitudes and occurrence rates, and the weakest static stabilities in the tropical lower stratosphere, occur during the QBOE phase under solar minimum (SMIN) conditions while the smallest amplitudes and strongest static stabilities occur during the QBOW phase under solar maximum (SMAX) conditions. Conversely, when the QBO and solar forcings are opposed (QBOW/SMIN and QBOE/SMAX), the difference in occurrence rates becomes statistically insignificant. During the coming solar minimum, at least one additional winter in the QBOE/SMIN category should occur (possibly as early as 2017/2018) during which especially large MJO amplitudes are expected and an initial test of these results will be possible.

Estimates of late Cenozoic climate change relevant to Earth surface processes in tectonically active orogens

NASA Astrophysics Data System (ADS)

Mutz, Sebastian G.; Ehlers, Todd A.; Werner, Martin; Lohmann, Gerrit; Stepanek, Christian; Li, Jingmin

2018-04-01

The denudation history of active orogens is often interpreted in the context of modern climate gradients. Here we address the validity of this approach and ask what are the spatial and temporal variations in palaeoclimate for a latitudinally diverse range of active orogens? We do this using high-resolution (T159, ca. 80 × 80 km at the Equator) palaeoclimate simulations from the ECHAM5 global atmospheric general circulation model and a statistical cluster analysis of climate over different orogens (Andes, Himalayas, SE Alaska, Pacific NW USA). Time periods and boundary conditions considered include the Pliocene (PLIO, ˜ 3 Ma), the Last Glacial Maximum (LGM, ˜ 21 ka), mid-Holocene (MH, ˜ 6 ka), and pre-industrial (PI, reference year 1850). The regional simulated climates of each orogen are described by means of cluster analyses based on the variability in precipitation, 2 m air temperature, the intra-annual amplitude of these values, and monsoonal wind speeds where appropriate. Results indicate the largest differences in the PI climate existed for the LGM and PLIO climates in the form of widespread cooling and reduced precipitation in the LGM and warming and enhanced precipitation during the PLIO. The LGM climate shows the largest deviation in annual precipitation from the PI climate and shows enhanced precipitation in the temperate Andes and coastal regions for both SE Alaska and the US Pacific Northwest. Furthermore, LGM precipitation is reduced in the western Himalayas and enhanced in the eastern Himalayas, resulting in a shift of the wettest regional climates eastward along the orogen. The cluster-analysis results also suggest more climatic variability across latitudes east of the Andes in the PLIO climate than in other time slice experiments conducted here. Taken together, these results highlight significant changes in late Cenozoic regional climatology over the last ˜ 3 Myr. Comparison of simulated climate with proxy-based reconstructions for the MH and LGM reveal satisfactory to good performance of the model in reproducing precipitation changes, although in some cases discrepancies between neighbouring proxy observations highlight contradictions between proxy observations themselves. Finally, we document regions where the largest magnitudes of late Cenozoic changes in precipitation and temperature occur and offer the highest potential for future observational studies that quantify the impact of climate change on denudation and weathering rates.

TU-H-CAMPUS-JeP3-05: Adaptive Determination of Needle Sequence HDR Prostate Brachytherapy with Divergent Needle-By-Needle Delivery

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

Borot de Battisti, M; Maenhout, M; Lagendijk, J J W

Purpose: To develop a new method which adaptively determines the optimal needle insertion sequence for HDR prostate brachytherapy involving divergent needle-by-needle dose delivery by e.g. a robotic device. A needle insertion sequence is calculated at the beginning of the intervention and updated after each needle insertion with feedback on needle positioning errors. Methods: Needle positioning errors and anatomy changes may occur during HDR brachytherapy which can lead to errors in the delivered dose. A novel strategy was developed to calculate and update the needle sequence and the dose plan after each needle insertion with feedback on needle positioning errors. Themore » dose plan optimization was performed by numerical simulations. The proposed needle sequence determination optimizes the final dose distribution based on the dose coverage impact of each needle. This impact is predicted stochastically by needle insertion simulations. HDR procedures were simulated with varying number of needle insertions (4 to 12) using 11 patient MR data-sets with PTV, prostate, urethra, bladder and rectum delineated. Needle positioning errors were modeled by random normally distributed angulation errors (standard deviation of 3 mm at the needle’s tip). The final dose parameters were compared in the situations where the needle with the largest vs. the smallest dose coverage impact was selected at each insertion. Results: Over all scenarios, the percentage of clinically acceptable final dose distribution improved when the needle selected had the largest dose coverage impact (91%) compared to the smallest (88%). The differences were larger for few (4 to 6) needle insertions (maximum difference scenario: 79% vs. 60%). The computation time of the needle sequence optimization was below 60s. Conclusion: A new adaptive needle sequence determination for HDR prostate brachytherapy was developed. Coupled to adaptive planning, the selection of the needle with the largest dose coverage impact increases chances of reaching the clinical constraints. M. Borot de Battisti is funded by Philips Medical Systems Nederland B.V.; M. Moerland is principal investigator on a contract funded by Philips Medical Systems Nederland B.V.; G. Hautvast and D. Binnekamp are fulltime employees of Philips Medical Systems Nederland B.V.« less

What Caused the UK's Largest Common Dolphin (Delphinus delphis) Mass Stranding Event?

PubMed Central

Jepson, Paul D.; Deaville, Robert; Acevedo-Whitehouse, Karina; Barnett, James; Brownlow, Andrew; Brownell Jr., Robert L.; Clare, Frances C.; Davison, Nick; Law, Robin J.; Loveridge, Jan; Macgregor, Shaheed K.; Morris, Steven; Murphy, Sinéad; Penrose, Rod; Perkins, Matthew W.; Pinn, Eunice; Seibel, Henrike; Siebert, Ursula; Sierra, Eva; Simpson, Victor; Tasker, Mark L.; Tregenza, Nick; Cunningham, Andrew A.; Fernández, Antonio

2013-01-01

On 9 June 2008, the UK's largest mass stranding event (MSE) of short-beaked common dolphins (Delphinus delphis) occurred in Falmouth Bay, Cornwall. At least 26 dolphins died, and a similar number was refloated/herded back to sea. On necropsy, all dolphins were in good nutritive status with empty stomachs and no evidence of known infectious disease or acute physical injury. Auditory tissues were grossly normal (26/26) but had microscopic haemorrhages (5/5) and mild otitis media (1/5) in the freshest cases. Five lactating adult dolphins, one immature male, and one immature female tested were free of harmful algal toxins and had low chemical pollutant levels. Pathological evidence of mud/seawater inhalation (11/26), local tide cycle, and the relative lack of renal myoglobinuria (26/26) suggested MSE onset on a rising tide between 06∶30 and 08∶21 hrs (9 June). Potential causes excluded or considered highly unlikely included infectious disease, gas/fat embolism, boat strike, by-catch, predator attack, foraging unusually close to shore, chemical or algal toxin exposure, abnormal weather/climatic conditions, and high-intensity acoustic inputs from seismic airgun arrays or natural sources (e.g., earthquakes). International naval exercises did occur in close proximity to the MSE with the most intense part of the exercises (including mid-frequency sonars) occurring four days before the MSE and resuming with helicopter exercises on the morning of the MSE. The MSE may therefore have been a “two-stage process” where a group of normally pelagic dolphins entered Falmouth Bay and, after 3–4 days in/around the Bay, a second acoustic/disturbance event occurred causing them to strand en masse. This spatial and temporal association with the MSE, previous associations between naval activities and cetacean MSEs, and an absence of other identifiable factors known to cause cetacean MSEs, indicates naval activity to be the most probable cause of the Falmouth Bay MSE. PMID:23646103

Predation by fallfish (Semotilus corporalis) on Pacific salmon eggs in the Salmon River, New York

USGS Publications Warehouse

Johnson, J. H.; Nack, C.C.; Chalupnicki, M.A.

2009-01-01

Fallfish (Semotilus corporalis) are the largest native cyprinid in the northeastern United States and are the most abundant native species in the Salmon River, New York. The Salmon River is a high-quality spawning and nursery river for Pacific salmon (Oncorhynchus spp.) migrating from Lake Ontario. Because of the large number of Pacific salmon spawning in the river in the fall extensive redd superimposition occurs resulting in salmonid eggs being available on the substrate. We examined the fall diet of 647 fallfish in 2007 and 2008 to determine the extent of predation on Pacific salmon eggs. The contribution of eggs in the diet significantly increased once fallfish attained a size of 100 mm total length. The largest size category of fallfish examined (≥150 mm) had the highest proportion (86.1%) of salmon eggs in their diet. The contribution of Zooplankton and chironomids in the diet of fallfish decreased with fish size. Except for the two largest groups of fallfish examined (i.e., 100–149 mm and ≥150 mm) diet overlap among size groups was low. The high contribution in the diet during the fall and high caloric value of Pacific salmon eggs could increase growth and survival of this species in the Salmon River.

Diurnal, seasonal and inter-annual variations in the Schumann resonance parameters

NASA Astrophysics Data System (ADS)

Price, Colin; Melnikov, Alexander

2004-09-01

The Schumann resonances (SR) represent an electromagnetic phenomenon in the Earth's atmosphere related to global lightning activity. The spectral characteristics of the SR modes are defined by their resonant mode amplitude, center frequency and half-width (Q-factor). Long-term (4 years) diurnal and seasonal variations of these parameters are presented based on measurements at a field site in the Negev desert, Israel. Variations of the different modes (8, 14 and 20Hz) and the different electromagnetic components (Hns, Hew and Ez) are presented. The power variations of the various modes and components show three dominant maxima in the diurnal cycle related to lightning activity in south-east Asia (0800UT), Africa (1400UT) and South America (2000UT). The largest global lightning activity occurs during the northern hemisphere summer (JJA) with the southern hemisphere summer (DJF) having the least lightning around the globe. The frequency and half-width (Q-factor) variations of the different modes and SR components are fairly complicated in structure, and will need additional theoretical work to explain their variations. However, the frequency variations are in excellent agreement with previous studies, implying that the frequency variations are robust features of the SR. The inter-annual variability of global lightning activity is shown to vary differently for each of the three major source regions of global lightning.

Spatial Variations of Spectral Properties of (21) Lutetia as Observed by OSIRIS/Rosetta

NASA Astrophysics Data System (ADS)

Leyrat, Cedric; Sierks, H.; Barbieri, C.; Barucci, A.; Da Deppo, V.; De Leon, J.; Fulchignoni, M.; Fornasier, S.; Groussin, O.; Hviid, S. F.; Jorda, L.; Keller, H. U.; La Forgia, F.; Lara, L.; Lazzarin, M.; Magrin, S.; Marchi, S.; Thomas, N.; Schroder, S. E.; OSIRIS Team

2010-10-01

On July 10, 2010, the Rosetta ESA/NASA spacecraft successfully flew by the asteroid (21) Lutetia, which becomes the largest asteroid observed by a space probe. The closest approach occurred at 15H45 UTC at a relative speed of 15km/s and a relative distance of 3160 km. The Narrow Angle Camera (NAC) and the Wide Angle Camera (WAC) of the OSIRIS instrument onboard Rosetta acquired images at different phase angles ranging from almost zero to more than 150 degrees. The best spatial resolution (60 m/pixel) allowed to reveal a very complex topography with several features and different crater's surface densities. Spectrophotometric analysis of the data could suggest spatial variations of the albedo and spectral properties at the surface of the asteroid, at least in the northern hemisphere. Numerous sets of data have been obtained at different wavelengths from 270nm to 980nm. We will first present a color-color analysis of data in order to locate landscapes where surface variegation is present. We will also present a more accurate study of spectral properties using the shape model and different statistical methods. Possible variations of the surface spectral properties with the slope of the ground and the gravity field orientation will be discussed as well.

Small-scale martian polygonal terrain: Implications for liquid surface water

USGS Publications Warehouse

Seibert, N.M.; Kargel, J.S.

2001-01-01

Images from the Mars Orbiter Camera (MOC) through August 1999 were analyzed for the global distribution of small-scale polygonal terrain not clearly resolved in Viking Orbiter imagery. With very few exceptions, small-scale polygonal terrain occurs at middle to high latitudes of the northern and southern hemisphere in Hesperian-age geologic units. The largest concentration of this terrain occurs in the Utopia basin in close association with scalloped depressions (interpreted as thermokarst) and appears to represent an Amazonia event. The morphology and occurence of small polygonal terrain suggest they are either mud desiccation cracks or ice-wedge polygons. Because the small-scale polygons in Utopia and Argyre Planitiae are associated with other cold-climate permafrost or glacial features, an ice-wedge model is preferred for these areas. Both cracking mechanisms work most effectively in water- or ice-rich finegrained material and may imply the seasonal or episodic existence of liquid water at the surface.

Assessment of the water supply:demand ratios in a Mediterranean basin under different global change scenarios and mitigation alternatives.

PubMed

Boithias, Laurie; Acuña, Vicenç; Vergoñós, Laura; Ziv, Guy; Marcé, Rafael; Sabater, Sergi

2014-02-01

Spatial differences in the supply and demand of ecosystem services such as water provisioning often imply that the demand for ecosystem services cannot be fulfilled at the local scale, but it can be fulfilled at larger scales (regional, continental). Differences in the supply:demand (S:D) ratio for a given service result in different values, and these differences might be assessed with monetary or non-monetary metrics. Water scarcity occurs where and when water resources are not enough to meet all the demands, and this affects equally the service of water provisioning and the ecosystem needs. In this study we assess the value of water in a Mediterranean basin under different global change (i.e. both climate and anthropogenic changes) and mitigation scenarios, with a non-monetary metric: the S:D ratio. We computed water balances across the Ebro basin (North-East Spain) with the spatially explicit InVEST model. We highlight the spatial and temporal mismatches existing across a single hydrological basin regarding water provisioning and its consumption, considering or not, the environmental demand (environmental flow). The study shows that water scarcity is commonly a local issue (sub-basin to region), but that all demands are met at the largest considered spatial scale (basin). This was not the case in the worst-case scenario (increasing demands and decreasing supply), as the S:D ratio at the basin scale was near 1, indicating that serious problems of water scarcity might occur in the near future even at the basin scale. The analysis of possible mitigation scenarios reveals that the impact of global change may be counteracted by the decrease of irrigated areas. Furthermore, the comparison between a non-monetary (S:D ratio) and a monetary (water price) valuation metrics reveals that the S:D ratio provides similar values and might be therefore used as a spatially explicit metric to valuate the ecosystem service water provisioning. © 2013.

Recognized Multiple Rifts of the Neoproterozoic in the Initiation of the Tarim Craton (NW China) and Their Tectonic Implications

NASA Astrophysics Data System (ADS)

He, B.; Jiao, C.; Huang, T.; Zhou, X.; Cai, Z.; Cao, Z.; Jiang, Z.; Cui, J.; Yu, Z.; Chen, W.

2017-12-01

The Tarim Basin is the largest, oil-bearing and superimposed basin in the northwest of China. The development and tectonic property of the initial Tarim basin have been acutely disputed and remain enigmatic. Urgently need to reveal the origin and formation dynamics of the Tarim Carton and evaluate the potential of the deep energy resources. However, covered by vast desert and huge-thickness sedimentary strata, suffered by multiple tectonic movements, seismic data with low signal- to- noise ratio in the deep are the critical difficulties. We analyse 4 field outcrops, 18 wells, 27 reprocessed seismic reflection profiles with high SNR across the basin and many ancillary ones and aeromagnetic data. We find about 20 normal fault-controlled rift depressions of the Cryogenian and Ediacaran scattered in the Tarim basin, which developed on the Precambrian metamorphic and crystalline basements and covered by the epeiric sea and basin facies sediments of the Lower Cambrian. The structural styles of the rifts are mainly half grabens, symmetrical troughs and horst-grabens. The regional differences exist obviously in spatial and temporal. The WNW-ESE-trending faults occur in the central part and northern of the basin and the NE, and the NEE-trending faults occur in the southern parts, which response with the anomaly of aeromagnetic. Some main faults of the Ediacaran inherited from the Cryogenian and some occurred newly, the more rifting depressions occurred during the Ediacaran. The extensional NNW-SSE-oriented and NNE-SSW-oriented paleostress field occurred simultaneously during rifting, and accompanied with the clockwise shearing. According to the activities of syn-sedimentary faults, magmatic events and sediments, the tectonic properties of the rifts are different depending on their locations in the Tarim craton. The rifting phases mainly occurred from 780 Ma to 615 Ma. The formation of rifts were associated with the opening of the South Tianshan Ocean and the South Altun-West Kunlun Oceans, which located at the north and south margin of the Tarim block, respectively, in response to break-up of the Rodinia supercontinent. The multiple rifts recognized reflect the fine-scale structure of the initiation of the Tarim craton and is the significant for understanding of the plate system and formation dynamics.

Water-quality trend analysis and sampling design for streams in North Dakota, 1971-2000

USGS Publications Warehouse

Vecchia, Aldo V.

2003-01-01

This report presents the results of a study conducted by the U.S. Geological Survey, in cooperation with the North Dakota Department of Health, to analyze historical water-quality trends in selected dissolved major ions, nutrients, and dissolved trace metals for 10 streams in southwestern and eastern North Dakota and to develop an efficient sampling design to monitor future water-quality trends. A time-series model for daily streamflow and constituent concentration was used to identify significant concentration trends, separate natural hydroclimatic variability in concentration from variability that could have resulted from anthropogenic causes, and evaluate various sampling designs to monitor future water-quality trends. The interannual variability in concentration as a result of variability in streamflow, referred to as the annual concentration anomaly, generally was high for all constituents and streams used in the trend analysis and was particularly sensitive to the severe drought that occurred in the late 1980's and the very wet period that began in 1993 and has persisted to the present (2002). Although climatic conditions were similar across North Dakota during the trend-analysis period (1971-2000), significant differences occurred in the annual concentration anomalies from constituent to constituent and location to location, especially during the drought and the wet period. Numerous trends were detected in the historical constituent concentrations after the annual concentration anomalies were removed. The trends within each of the constituent groups (major ions, nutrients, and trace metals) showed general agreement among the streams. For most locations, the largest dissolved major-ion concentrations occurred during the late 1970's and concentrations in the mid- to late 1990's were smaller than concentrations during the late 1970's. However, the largest concentrations for three of the Missouri River tributaries and one of the Red River of the North tributaries occurred during the mid- to late 1990's. Concentration trends for total ammonia plus organic nitrogen showed close agreement among the streams for which that constituent was evaluated. The largest concentrations occurred during the early 1980's, and the smallest concentrations occurred during the early 1990's. Nutrient data were not available for the early 1970's or late 1990's. Although a detailed analysis of the causes of the trends was beyond the scope of this report, a preliminary analysis of cropland, livestock-inventory, and oil-production data for 1971-2000 indicated the concentration trends may be related to the livestock-inventory and oil-production activities in the basins. Dissolved iron and manganese concentrations for the southwestern North Dakota streams generally remained stable during 1971-2000. However, many of the recorded concentrations for those streams were less than the detection limit, and trends that were masked by censoring may have occurred. Several significant trends were detected in dissolved iron and manganese concentrations for the eastern North Dakota streams. Concentrations for those streams either remained stable or increased during most of the 1970's and then decreased rapidly for about 2 years beginning in the late 1970's. The concentrations were relatively stable from the early 1980's to 2000 except at two locations where dissolved iron concentrations increased during the early 1990's. The most efficient overall sampling designs for the detection of annual trends (that is, trends that occur uniformly during the entire year) consisted of balanced designs in which the sampling dates and the number of samples collected remained fixed from year to year and in which the samples were collected throughout the year rather than in a short timespan. The best overall design for the detection of annual trends consisted of three samples per year, with samples collected near the beginning of December, April, and August. That design had acceptable sensitivity for the detection of trends in most constituents at all locations. Little improvement in sensitivity was achieved by collecting more than three samples per year.The sampling designs that were first evaluated for annual trends also were evaluated with regard to their sensitivity to detect seasonal trends that occurred during three seasons--April through August, August through December, and December through April. Design results indicated that an average of one extra sample per station per year resulted in an efficient design for detecting seasonal trends. However, allocation of the extra samples varied depending on the station, month, and constituent group (major ions, nutrients, and trace metals).

Sampling for Global Epidemic Models and the Topology of an International Airport Network

PubMed Central

Bobashev, Georgiy; Morris, Robert J.; Goedecke, D. Michael

2008-01-01

Mathematical models that describe the global spread of infectious diseases such as influenza, severe acute respiratory syndrome (SARS), and tuberculosis (TB) often consider a sample of international airports as a network supporting disease spread. However, there is no consensus on how many cities should be selected or on how to select those cities. Using airport flight data that commercial airlines reported to the Official Airline Guide (OAG) in 2000, we have examined the network characteristics of network samples obtained under different selection rules. In addition, we have examined different size samples based on largest flight volume and largest metropolitan populations. We have shown that although the bias in network characteristics increases with the reduction of the sample size, a relatively small number of areas that includes the largest airports, the largest cities, the most-connected cities, and the most central cities is enough to describe the dynamics of the global spread of influenza. The analysis suggests that a relatively small number of cities (around 200 or 300 out of almost 3000) can capture enough network information to adequately describe the global spread of a disease such as influenza. Weak traffic flows between small airports can contribute to noise and mask other means of spread such as the ground transportation. PMID:18776932

Photospheric Current Spikes And Their Possible Association With Flares - Results from an HMI Data Driven Model

NASA Astrophysics Data System (ADS)

Goodman, M. L.; Kwan, C.; Ayhan, B.; Eric, S. L.

2016-12-01

A data driven, near photospheric magnetohydrodynamic model predicts spikes in the horizontal current density, and associated resistive heating rate. The spikes appear as increases by orders of magnitude above background values in neutral line regions (NLRs) of active regions (ARs). The largest spikes typically occur a few hours to a few days prior to M or X flares. The spikes correspond to large vertical derivatives of the horizontal magnetic field. The model takes as input the photospheric magnetic field observed by the Helioseismic & Magnetic Imager (HMI) on the Solar Dynamics Observatory (SDO) satellite. This 2.5 D field is used to determine an analytic expression for a 3 D magnetic field, from which the current density, vector potential, and electric field are computed in every AR pixel for 14 ARs. The field is not assumed to be force-free. The spurious 6, 12, and 24 hour Doppler periods due to SDO orbital motion are filtered out of the time series of the HMI magnetic field for each pixel. The subset of spikes analyzed at the pixel level are found to occur on HMI and granulation scales of 1 arcsec and 12 minutes. Spikes are found in ARs with and without M or X flares, and outside as well as inside NLRs, but the largest spikes are localized in the NLRs of ARs with M or X flares. The energy to drive the heating associated with the largest current spikes comes from bulk flow kinetic energy, not the electromagnetic field, and the current density is highly non-force free. The results suggest that, in combination with the model, HMI is revealing strong, convection driven, non-force free heating events on granulation scales, and it is plausible these events are correlated with subsequent M or X flares. More and longer time series need to be analyzed to determine if such a correlation exists.

Elevation change (2000-2004) on the Malaspina Glacier, Alaska

NASA Technical Reports Server (NTRS)

Sauber, J.; Molnia, B.; Carabajal, C.; Luthcke, S.; Muskett, R.

2005-01-01

The glaciers of the southeastern Alaska coastal region are the largest temperate glacier meltwater source on Earth and may contribute one third of the total glacier meltwater entering the global ocean. Since melt onset and refreeeze timing in this region show a tendency toward earlier onset and longer ablation seasons, accelerated glacier wastage may be occurring. In this study we focus on one of the largest temperate glacier systems on Earth, the Malaspina Glacier. This glacier, with a length of approximately 110 km and an area of approximately square 5,000 km, has the largest piedmont lobe of any temperate glacier. The entire lobe, which lies at elevations below 600 m, is within the ablation zone. We report and interpret ice elevation change between a digital elevation model (DEM) derived from the Shuttle Radar Topography Mission (SRTM C band) observations in Feb. 2000 and ICESat Laser 1-3 observations between Feb. 2003 and Nov. 2004. We use these elevation change results, along with earlier studies, to address the spatial and temporal variability in wastage of the piedmont lobe. Between 2000 and 2004 ice elevation changes of 10-30 meters occurred across the central Malaspina piedmont lobe. From 1972/73 (USGS DEM) to 1999 (SRTM corrected for estimated winter snow accumulation) Malaspina's (Agassiz, Seward Lobe, and Marvine) mean ice thinning was estimated at -47 m with maximum thinning on parts of the lobes to -160 m. The Malaspina's accumulation area is only slightly larger than its ablation area (2,575 km2 vs. 2,433 km2); unfortunately few glaciological observations are available from this source region. Snow accumulation rates have been largely inferred from low-altitude precipitation and temperature data. Comparing sequential ICESat observations in the Malaspina source region, we estimated short-term elevation increases of up to 5 meters during the winter of 2003/04.

Decomposing race and gender differences in underweight and obesity in South Africa.

PubMed

Averett, Susan L; Stacey, Nicholas; Wang, Yang

2014-12-01

Using data from the National Income Dynamics Study, we document differentials in both underweight and obesity across race and gender in post-Apartheid South Africa. Using a nonlinear decomposition method, we decompose these differences across gender within race and then across race within gender. Less than one third of the differences in obesity and underweight across gender are explained by differences in covariates. In contrast, at least 70% of the obesity differences across race are explained by differences in covariates. Behavioral variables such as smoking and exercise explain the largest part of the bodyweight differentials across gender. For bodyweight differentials across race within gender, however, socioeconomic status and background variables have the largest explanatory power for obesity differentials, while background variables play the key role in explaining the underweight differentials. These results indicate that eradicating obesity and underweight differentials will require targeting policies to specific groups. Copyright © 2014 Elsevier B.V. All rights reserved.

Research for Developing Renewable Biofuels from Algae

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

Black, Paul N.

Task A. Expansion of knowledge related to lipid production and secretion in algae A.1 Lipid biosynthesis in target algal species; Systems biology approaches are being used in combination with recent advances in Chlorella and Chlamydomonas genomics to address lipid accumulation in response to defined nutrient regimes. The UNL Algal Group continues screening additional species of Chlorella and other naturally occurring algae for those with optimal triglyceride production; Of the strains examined by the DOE's Aquatic Species Program, green algae, several species of Chlorella represent the largest group from which oleaginous candidates have been identified; A.1.1. Lipid profiling; Neutral lipid accumulationmore » is routinely monitored by Nile red and BODIPY staining using high throughput strategies to screen for naturally occurring algae that accumulate triglyceride. These strategies complement those using spectrofluorometry to quantify lipid accumulation; Neutral lipid accumulation is routinely monitored by high performance thin-layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) of lipid extracts in conjunction with; Carbon portioning experiments have been completed and the data currently are being analyzed and prepared for publication; Methods in the Black lab were developed to identify and quantify triacylglycerol (TAG), major membrane lipids [diacylglycerol trimethylhomoserine, phosphatidylethanolamine and chloroplast glycolipids], biosynthetic intermediates such as diacylglycerol, phosphatidic acid and lysophospholipids and different species of acyl-coenzyme A (acyl CoA).« less

Community immunization programme in response to an outbreak of invasive Neisseria meningitidis serogroup C infection in the Trent region of England 1995-1996.

PubMed

Irwin, D J; Miller, J M; Milner, P C; Patterson, T; Richards, R G; Williams, D A; Insley, C A; Stuart, J M

1997-06-01

Between 8 December 1995 and 16 January 1996 seven laboratory confirmed cases of septicaemia owing to infection with Neisseria meningitidis serogroup C strains and one highly probable case of meningococcal septicaemia occurred in three electoral wards in south Rotherham and the Retford area of north Nottinghamshire. All cases occurred among children aged 1-17 years. One patient died. The public health response to this outbreak was the largest community prophylactic antibiotic and immunization programme against meningococcal infection, to date, in the United Kingdom. The target group for each Health Authority was 8900 for Rotherham Health Authorities and 8000 for North Nottinghamshire Health. Local logistical factors led to differences in the implementation of the programme by each Health Authority. At the completion of each programme, 8320 doses of vaccine had been administered (92.5 per cent coverage) during the Rotherham Health Authorities programme and 7660 (95.7 per cent coverage) during the North Nottinghamshire Health programme. The additional financial cost of the exercise amounted to approximately Pounds 125000 for each Health Authority. This paper describes the evolution of the outbreak, the decision-making process resulting in the immunization programme in each Health Authority, the implementation of each programme, problems identified and lessons learned.

Tobacco Smoke Pollution in Hospitality Venues Before and After Passage of Statewide Smoke-Free Legislation.

PubMed

Buettner-Schmidt, Kelly; Boursaw, Blake; Lobo, Marie L; Travers, Mark J

2017-03-01

In 2012, North Dakota enacted a comprehensive statewide law prohibiting smoking in enclosed public places. Disparities in tobacco control exist in rural areas. This study's objective was to determine the extent to which the passage of a comprehensive, statewide, smoke-free law in a predominantly rural state influenced tobacco smoke pollution in rural and nonrural venues. A longitudinal cohort design study comparing the levels of tobacco smoke pollution before and after passage of the statewide smoke-free law was conducted in 64 restaurants and bars statewide in North Dakota. Particulate matter with a median aerodynamic diameter of <2.5 μm (a valid atmospheric marker of tobacco smoke pollution) was assessed. A significant 83% reduction in tobacco smoke pollution levels occurred after passage of the law. Significant reductions in tobacco smoke pollution levels occurred in each of the rural categories; however, no difference by rurality was noted in the analysis after passage of the law, in contrast to the study before passage. To our knowledge, this was the largest, single, rural postlaw study globally. A comprehensive statewide smoke-free law implemented in North Dakota dramatically decreased the level of tobacco smoke pollution in bars and restaurants. © 2016 The Authors. Public Health Nursing Published by Wiley Periodicals, Inc.

Evolutionary processes and sources of high-nitrate haze episodes over Beijing, Spring.

PubMed

Yang, Ting; Sun, Yele; Zhang, Wei; Wang, Zifa; Liu, Xingang; Fu, Pingqing; Wang, Xiquan

2017-04-01

Rare and consecutive high-nitrate haze pollution episodes were observed in Beijing in spring 2012. We present detailed characterization of the sources and evolutionary mechanisms of this haze pollution, and focus on an episode that occurred between 15 and 26 April. Submicron aerosol species were found to be substantially elevated during haze episodes, and nitrates showed the largest increase and occupation (average: 32.2%) in non-refractory submicron particles (NR-PM 1 ), which did not occur in other seasons as previously reported. The haze episode (HE) was divided into three sub-episodes, HEa, HEb, and HEc. During HEa and HEc, a shallow boundary layer, stagnant meteorological conditions, and high humidity favored the formation of high-nitrate concentrations, which were mainly produced by three different processes - daytime photochemical production, gas-particle partitioning, and nighttime heterogeneous reactions - and the decline in visibility was mainly induced by NR-PM 1. However, unlike HEa and HEc, during HEb, the contribution of high nitrates was partly from the transport of haze from the southeast of Beijing - the transport pathway was observed at ~800-1000m by aerosol Lidar - and the decline in visibility during HEb was primarily caused by PM 2.5 . Our results provide useful information for air quality improvement strategies in Beijing during Spring. Copyright © 2016. Published by Elsevier B.V.

The timing of galvanic vestibular stimulation affects responses to platform translation

NASA Technical Reports Server (NTRS)

Hlavacka, F.; Shupert, C. L.; Horak, F. B.; Peterson, B. W. (Principal Investigator)

1999-01-01

We compared the effects of galvanic vestibular stimulation applied at 0, 0.5, 1.5 and 2.5 s prior to a backward platform translation on postural responses. The effect of the galvanic stimulation was largest on the final equilibrium position of the center of pressure (CoP). The largest effects occurred for the 0.5 and 0-s pre-period, when the dynamic CoP pressure changes in response to both the galvanic stimulus and the platform translation coincided. The shift in the final equilibrium position was also larger than the sum of the shifts for the galvanic stimulus and the platform translation alone for the 0.5 and 0-s pre-periods. The initial rate of change of the CoP response to the platform translation was not significantly affected in any condition. Changes in the peak CoP position could be accounted for by local interaction of CoP velocity changes induced by the galvanic and translation responses alone, but the changes in final equilibrium position could only be accounted for by a change in global body orientation. These findings suggest that the contribution of vestibulospinal information is greatest during the dynamic phase of the postural response, and that the vestibular system contributes most to the later components of the postural response, particularly to the final equilibrium position. These findings suggest that a nonlinear interaction between the vestibular signal induced by the galvanic current and the sensory stimuli produced by the platform translation occurs when the two stimuli are presented within 1 s, during the dynamic phase of the postural response to the galvanic stimulus. When presented at greater separations in time, the stimuli appear to be treated as independent events, such that no interaction occurs. Copyright 1999 Elsevier Science B.V.

Climate Response of Direct Radiative Forcing of Anthropogenic Black Carbon

NASA Technical Reports Server (NTRS)

Chung, Serena H.; Seinfeld,John H.

2008-01-01

The equilibrium climate effect of direct radiative forcing of anthropogenic black carbon (BC) is examined by 100-year simulations in the Goddard Institute for Space Studies General Circulation Model II-prime coupled to a mixed-layer ocean model. Anthropogenic BC is predicted to raise globally and annually averaged equilibrium surface air temperature by 0.20 K if BC is assumed to be externally mixed. The predicted increase is significantly greater in the Northern Hemisphere (0.29 K) than in the Southern Hemisphere (0.11 K). If BC is assumed to be internally mixed with the present day level of sulfate aerosol, the predicted annual mean surface temperature increase rises to 0.37 K globally, 0.54 K for the Northern Hemisphere, and 0.20 K for the Southern Hemisphere. The climate sensitivity of BC direct radiative forcing is calculated to be 0.6 K W (sup -1) square meters, which is about 70% of that of CO2, independent of the assumption of BC mixing state. The largest surface temperature response occurs over the northern high latitudes during winter and early spring. In the tropics and midlatitudes, the largest temperature increase is predicted to occur in the upper troposphere. Direct radiative forcing of anthropogenic BC is also predicted to lead to a change of precipitation patterns in the tropics; precipitation is predicted to increase between 0 and 20 N and decrease between 0 and 20 S, shifting the intertropical convergence zone northward. If BC is assumed to be internally mixed with sulfate instead of externally mixed, the change in precipitation pattern is enhanced. The change in precipitation pattern is not predicted to alter the global burden of BC significantly because the change occurs predominantly in regions removed from BC sources.

Recent trends in the probability of high out-of-pocket medical expenses in the United States

PubMed Central

Baird, Katherine E

2016-01-01

Objective: This article measures the probability that out-of-pocket expenses in the United States exceed a threshold share of income. It calculates this probability separately by individuals’ health condition, income, and elderly status and estimates changes occurring in these probabilities between 2010 and 2013. Data and Method: This article uses nationally representative household survey data on 344,000 individuals. Logistic regressions estimate the probabilities that out-of-pocket expenses exceed 5% and alternatively 10% of income in the two study years. These probabilities are calculated for individuals based on their income, health status, and elderly status. Results: Despite favorable changes in both health policy and the economy, large numbers of Americans continue to be exposed to high out-of-pocket expenditures. For instance, the results indicate that in 2013 over a quarter of nonelderly low-income citizens in poor health spent 10% or more of their income on out-of-pocket expenses, and over 40% of this group spent more than 5%. Moreover, for Americans as a whole, the probability of spending in excess of 5% of income on out-of-pocket costs increased by 1.4 percentage points between 2010 and 2013, with the largest increases occurring among low-income Americans; the probability of Americans spending more than 10% of income grew from 9.3% to 9.6%, with the largest increases also occurring among the poor. Conclusion: The magnitude of out-of-pocket’s financial burden and the most recent upward trends in it underscore a need to develop good measures of the degree to which health care policy exposes individuals to financial risk, and to closely monitor the Affordable Care Act’s success in reducing Americans’ exposure to large medical bills. PMID:27651901

Mississippi River Delta, Louisiana as seen from STS-62

NASA Technical Reports Server (NTRS)

1994-01-01

The Mississippi River Delta, Louisiana as seen from STS-62, is the largest river system in North America. The interdistributary bays are extremely shallow, usually less than a few meters, and contain brackish to normal marine waters except during times of flooding, when fresh water fills the bays. Sedimentation within the bays is very low, occurring only during flood periods. Along the west side of the river, a highway has been built southeastward to Venice.

Two-Color V and R CCD Photometry of the SW Sex-Type Eclipsing Cataclysmic Variable V1315 Aql

NASA Astrophysics Data System (ADS)

Andronov, I. L.; Baklanov, A. V.; Burwitz, V.

2005-08-01

The V-R color index shows a complicated behaviour during the eclipse, being largest at the brightness minimum, but showing asymmetric minima at phases -0.07 and +0.13. The hump at the light curve occurs after the eclipse, contrary to systems with the "hot spot". The phases of minima in V and R are 0.0092(17) and 0.0062(17), respectively, for the mean date JD=2453202.

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

Anderson, W.F.; Martinell, J.; Whitney, J.B. III

The group of diseases called the thalassemias is the largest single-gene health problem in the world according the World Health Organization. The thalassemias are lethal hereditary anemias in which the infants cannot make their own blood. Three mouse mutants are shown to be models of the human disease ..cap alpha..-thalassemia. However, since an additional gene is affected, these mutants represent a particularly severe condition in which death occurs in the homozygous embryo even before globin genes are activated. Phenotypic and genotypic characteristics are described. (ACR)

Objective detection and forecasting of Clear-Air Turbulence (CAT): A status report

NASA Technical Reports Server (NTRS)

Keller, John L.

1988-01-01

Clear-air turbulence has become the largest single cause of weather-related injuries occurring in commercial carriers at cruising altitudes. A technique for objective operational CAT detection (the SCATR index) has been formulated. Its physical basis ties CAT to total energy dissipation as a response to meso- and synoptic-scale dynamical processes associated with upper-level jet stream/frontal zones. Early case studies using properly analyzed routine RAOB rawinsonde sounding data have shown promise.

How Deployments Affect the Capacity and Utilization of Army Treatment Facilities

DTIC Science & Technology

2014-01-01

and nurse practitioner —accounted for the majority of the increase in non-active-duty providers in the 14 MTFs, with the largest growth occurring...parents to decline dra- matically when soldiers deploy, we do not know the extent to which need is unmet. While we are cautioned in prior research that... needed , and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of

Spatial correlation of the dynamic propensity of a glass-forming liquid

NASA Astrophysics Data System (ADS)

Razul, M. Shajahan G.; Matharoo, Gurpreet S.; Poole, Peter H.

2011-06-01

We present computer simulation results on the dynamic propensity (as defined by Widmer-Cooper et al 2004 Phys. Rev. Lett. 93 135701) in a Kob-Andersen binary Lennard-Jones liquid system consisting of 8788 particles. We compute the spatial correlation function for the dynamic propensity as a function of both the reduced temperature T, and the time scale on which the particle displacements are measured. For T <= 0.6, we find that non-zero correlations occur at the largest length scale accessible in our system. We also show that a cluster-size analysis of particles with extremal values of the dynamic propensity, as well as 3D visualizations, reveal spatially correlated regions that approach the size of our system as T decreases, consistently with the behavior of the spatial correlation function. Next, we define and examine the 'coordination propensity', the isoconfigurational average of the coordination number of the minority B particles around the majority A particles. We show that a significant correlation exists between the spatial fluctuations of the dynamic and coordination propensities. In addition, we find non-zero correlations of the coordination propensity occurring at the largest length scale accessible in our system for all T in the range 0.466 < T < 1.0. We discuss the implications of these results for understanding the length scales of dynamical heterogeneity in glass-forming liquids.

Simulated effects of increased groundwater withdrawals in the Cave Springs area, Hixson, Tennessee

USGS Publications Warehouse

Haugh, Connor J.

2014-01-01

Under scenarios A and B, the largest change in the water budget occurs for flow to Cave Springs with decreases of 1.9 and 4.7 ft3/s, respectively. Similarly, groundwater discharge to North Chickamauga Creek decreases by 1.0 ft3/s and 2.6 ft33/s, respectively. Under scenarios C and D, the largest change in the water budget occurs for flow to Chickamauga Lake with decreases of 1.3 ft3/s and 2.3 ft3/s, respectively. Similarly, groundwater discharge to North Chickamauga Creek decreases by 1.1 ft3/s and 2.1 ft3/s, respectively. Changes in groundwater levels at the well fields were also analyzed. At the Cave Springs well field, maximum declines in groundwater levels due to additional pumpage are less than 1 foot for all scenarios. Groundwater level changes at the Cave Springs well field are small due to the highly transmissive nature of the aquifer in this location. Maximum groundwater-level declines at Walkers Corner are less than 1 foot for scenarios A and B and about 52 feet and 82 feet for scenarios C and D, respectively. Under scenarios C and D, the regional potentiometric surface shows a large cone of depression centered on the Walkers Corner well field and elongated along geologic strike.

The combined influence of sub-optimal temperature and salinity on the in vitro viability of Perkinsus marinus, a protistan parasite of the eastern oyster Crassostrea virginica

USGS Publications Warehouse

La Peyre, M.K.; Casas, S.M.; Gayle, W.; La Peyre, Jerome F.

2010-01-01

Perkinsus marinus is a major cause of mortality in eastern oysters along the Gulf of Mexico and Atlantic coasts. It is also well documented that temperature and salinity are the primary environmental factors affecting P. marinus viability and proliferation. However, little is known about the effects of combined sub-optimal temperatures and salinities on P. marinus viability. This in vitro study examined those effects by acclimating P. marinus at three salinities (7, 15, 25. ppt) to 10 ??C to represent the lowest temperatures generally reached in the Gulf of Mexico, and to 2 ??C to represent the lowest temperatures reached along the mid-Atlantic coasts and by measuring changes in cell viability and density on days 1, 30, 60 and 90 following acclimation. Cell viability and density were also measured in 7. ppt cultures acclimated to each temperature and then transferred to 3.5. ppt. The largest decreases in cell viability occurred only with combined low temperature and salinity, indicating that there is clearly a synergistic effect. The largest decreases in cell viability occurred only with both low temperature and salinity after 30. days (3.5. ppt, 2 ??C: 0% viability), 60. days (3.5. ppt, 10 ??C: 0% viability) and 90. days (7. ppt, 2 ??C: 0.6 ?? 0.7%; 7. ppt, 10 ??C: 0.2 ?? 0.2%). ?? 2010 .

[Submicroscopic changes in ciliated cells of the epithelium of the oviduct in cows during the estrus cycle].

PubMed

Uhrín, V; Kliment, J

1983-03-01

The submicroscopic changes in the ciliary cells of the ampullar part of oviduct are of qualitative as well as quantitative nature. The mitochondria are mainly located in the supranuclear region. They are small, having densely arranged lamelliform cristae and dense matrix. They have the largest volume in metoestrus and the highest number and the largest surface already during oestrus. The volume and surface of granular endoplasmic reticulum culminates already during pro-oestrus. The reticulum occurs mainly over the nucleus where it produces tubuli densely covered with ribosomes which begin to dilate already during pro-oestrus. The Golgi apparatus and the membranes of smooth reticulum are poorly developed and their quantitative changes during the cycle are not significant. Various forms of lysosomes, whose volume reaches its maximum in dioestrus and during pro-oestrus, constitute a constant component of cytoplasm. Secretory granules occur only rarely in these cells. Kinocilia grow from the basal corpuscles and are more frequent on cells with a light cytoplasm. Higher-density cells have more micro-villi between kinocilia. Deciliation with the disintegration of membrane, filaments and often also the basal corpuscles is observed during metoestrus and at the beginning of dioestrus. Reciliation begins with the formation of basal corpuscles and their replication at the end of dioestrus and in pro-oestrus. The frequency of ciliary regeneration is comparatively small.

Flood of May 23, 2004, in the Turkey and Maquoketa River basins, northeast Iowa

USGS Publications Warehouse

Eash, David A.

2006-01-01

Severe flooding occurred on May 23, 2004, in the Turkey River Basin in Clayton County and in the Maquoketa River Basin in Delaware County following intense thunderstorms over northeast Iowa. Rain gages at Postville and Waucoma, Iowa, recorded 72-hour rainfall of 6.32 and 6.55 inches, respectively, on May 23. Unofficial rainfall totals of 8 to 10 inches were reported in the Turkey River Basin. The peak discharge on May 23 at the Turkey River at Garber streamflow-gaging station was 66,700 cubic feet per second (recurrence interval greater than 500 years) and is the largest flood on record in the Turkey River Basin. The timing of flood crests on the Turkey and Volga Rivers, and local tributaries, coincided to produce a record flood on the lower part of the Turkey River. Three large floods have occurred at the Turkey River at Garber gaging station in a 13-year period. Peak discharges of the floods of June 1991 and May 1999 were 49,900 cubic feet per second (recurrence interval about 150 years) and 53,900 cubic feet per second (recurrence interval about 220 years), respectively. The peak discharge on May 23 at the Maquoketa River at Manchester gaging station was 26,000 cubic feet per second (recurrence interval about 100 years) and is the largest known flood in the upper part of the Maquoketa River Basin.

The Great Tumaco, Colombia earthquake of 12 December 1979

USGS Publications Warehouse

Herd, D.G.; Youd, T.L.; Meyer, H.; Arango, C.J.L.; Person, W.J.; Mendoza, C.

1981-01-01

Southwestern Colombia and northern Ecuador were shaken by a shallow-focus earthquake on 12 December 1979. The magnitude 8 shock, located near Tumaco, Colombia, was the largest in northwestern South America since 1942 and had been forecast to fill a seismic gap. Thrust faulting occurred on a 280- by 130-kilometer rectangular patch of a subduction zone that dips east beneath the Pacific coast of Colombia. A 200-kilometer stretch of the coast tectonically subsided as much as 1.6 meters; uplift occurred offshore on the continental slope. A tsunami swept inland immediately after the earthquake. Ground shaking (intensity VI to IX) caused many buildings to collapse and generated liquefaction in sand fills and in Holocene beach, lagoonal, and fluvial deposits.

Preliminary volcano-hazard assessment for Aniakchak Volcano, Alaska

USGS Publications Warehouse

Neal, Christina A.; McGimsey, Robert G.; Miller, Thomas P.; Riehle, James R.; Waythomas, Christopher F.

2000-01-01

Aniakchak is an active volcano located on the Alaska Peninsula 670 kilometers southwest of Anchorage. The volcano consists of a dramatic, 10-kilometer-diameter, 0.5 to 1.0-kilometer-deep caldera that formed during a catastrophic eruption 3,500 years ago. Since then, at least a dozen separate vents within the caldera have erupted, often explosively, to produce lava flows and widespread tephra (ash) deposits. The most recent eruption at Aniakchak occurred in 1931 and was one of the largest explosive eruptions in Alaska in the last 100 years. Although Aniakchak volcano presently shows no signs of unrest, explosive and nonexplosive eruptions will occur in the future. Awareness of the hazards posed by future eruptions is a key factor in minimizing impact.

Strong earthquakes, novae and cosmic ray environment

NASA Technical Reports Server (NTRS)

Yu, Z. D.

1985-01-01

Observations about the relationship between seismic activity and astronomical phenomena are discussed. First, after investigating the seismic data (magnitude 7.0 and over) with the method of superposed epochs it is found that world seismicity evidently increased after the occurring of novae with apparent magnitude brighter than 2.2. Second, a great many earthquakes of magnitude 7.0 and over occurred in the 13th month after two of the largest ground level solar cosmic ray events (GLEs). The causes of three high level phenomena of global seismic activity in 1918-1965 can be related to these, and it is suggested that according to the information of large GLE or bright nova predictions of the times of global intense seismic activity can be made.

A seismic gap along an accreting plate boundary : Example of the Djibouti Ridge, Afar, East Africa

NASA Astrophysics Data System (ADS)

Ruegg, Jean-Claude; Lépine, Jean-Claude

1983-05-01

A segment of the Gulf of Tadjoura (Djibouti, East-Africa) accreting plate boundary, shows a period of quiescence in the seismic activity since 1974. This segment corresponds to the extension area of the aftershock activity that has occured after a cluster of magnitude 5.5 earthquakes in April 1973. From this example we propose that the seismic gap concept can be extended to moderate earthquakes occuring at extensional plate boundaries. The magnitude of the largest earthquakes at the spreading axis is limited by the size of the rupture length and by the strength of the brittle lithosphere. In the case of the Djibouti ridge recurrence time of 10-20 years are found for earthquakes of about M =6.

The occurence of uric acids and the growth morphology of the anhydrous monoclinic modification : C 5H 4N 4O 3

NASA Astrophysics Data System (ADS)

Rinaudo, C.; Boistelle, R.

1980-07-01

Anhydrous and hydrated uric acid crystals which frequently occur in human urolithiasis have been grown from pure aqueous solutions at 25 and 37°C. The appearance domain of either modification is given as a function of initial uric acid concentration at pH values ranging from 3.0 to 5.5. The present paper mostly deals with the anhydrous phase and it is shown that its experimental and theoretical growth morphologies are in agreement, the crystals exhibiting the {100}, {210}, {121}, {001} and {201} forms. Crystal habit depends on supersaturation; {100} has always the largest extension at low supersaturation {121} develops to the detriment of {210}, {001} and {201}.

Synoptic typing: interdisciplinary application methods with three practical hydroclimatological examples

NASA Astrophysics Data System (ADS)

Siegert, C. M.; Leathers, D. J.; Levia, D. F.

2017-05-01

Synoptic classification is a methodology that represents diverse atmospheric variables and allows researchers to relate large-scale atmospheric circulation patterns to regional- and small-scale terrestrial processes. Synoptic classification has often been applied to questions concerning the surface environment. However, full applicability has been under-utilized to date, especially in disciplines such as hydroclimatology, which are intimately linked to atmospheric inputs. This paper aims to (1) outline the development of a daily synoptic calendar for the Mid-Atlantic (USA), (2) define seasonal synoptic patterns occurring in the region, and (3) provide hydroclimatological examples whereby the cascading response of precipitation characteristics, soil moisture, and streamflow are explained by synoptic classification. Together, achievement of these objectives serves as a guide for development and use of a synoptic calendar for hydroclimatological studies. In total 22 unique synoptic types were identified, derived from a combination of 12 types occurring in the winter (DJF), 13 in spring (MAM), 9 in summer (JJA), and 11 in autumn (SON). This includes six low pressure systems, four high pressure systems, one cold front, three north/northwest flow regimes, three south/southwest flow regimes, and five weakly defined regimes. Pairwise comparisons indicated that 84.3 % had significantly different rainfall magnitudes, 86.4 % had different rainfall durations, and 84.7 % had different rainfall intensities. The largest precipitation-producing classifications were not restricted to low pressure systems, but rather to patterns with access to moisture sources from the Atlantic Ocean and easterly (on-shore) winds, which transport moisture inland. These same classifications resulted in comparable rates of soil moisture recharge and streamflow discharge, illustrating the applicability of synoptic classification for a range of hydroclimatological research objectives.

Nitrous oxide exchanges with the atmosphere of a constructed wetland treating wastewater. Parameters and implications for emission factors

NASA Astrophysics Data System (ADS)

Johansson, A. E.; Kasimir Klemedtsson, Å.; Klemedtsson, L.; Svensson, B. H.

2003-07-01

Static chamber measurements of N2O fluxes were taken during the 1998 and 1999 growth seasons in a Swedish constructed wetland receiving wastewater. The dominating plant species in different parts of the wetland were Lemna minor L., Typha latifolia L., Spirogyra sp. and Glyceria maxima (Hartm.) and Phalaris arundinacea (L.), respectively. There were large temporal and spatial variations in N2O fluxes, which ranged from consumption at -350 to emissions at 1791 μg N2O m-2 h-1. The largest positive flux occurred in October 1999 and the lowest in the middle of July 1999. The average N2O flux for the two years was 130 μg N2O m-2 h-1 (SD = 220). No significant differences in N2O fluxes were found between the years, even though the two growing seasons differed considerably with respect to both air temperature and precipitation. 15% of the fluxes were negative, showing a consumption of N2O. Consumption occurred on a few occasions at most measurement sites and ranged from 1-350 μg N2O m-2 h-1. 13-43% of the variation in N2O fluxes was explained by multiple linear regression analysis including principal components. Emission factors were calculated according to IPCC methods from the N2O fluxes in the constructed wetland. The calculated emission factors were always lower (0.02-0.27%) compared to the default factor provided by the IPCC (0.75%). Thus, direct application of the IPCC default factor may lead to overestimation of N2O fluxes from constructed wastewater-treating wetlands.

Intracellular Cadmium Isotope Fractionation

NASA Astrophysics Data System (ADS)

Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

2011-12-01

Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

LRPPRC mutations cause a phenotypically distinct form of Leigh syndrome with cytochrome c oxidase deficiency.

PubMed

Debray, François-Guillaume; Morin, Charles; Janvier, Annie; Villeneuve, Josée; Maranda, Bruno; Laframboise, Rachel; Lacroix, Jacques; Decarie, Jean-Claude; Robitaille, Yves; Lambert, Marie; Robinson, Brian H; Mitchell, Grant A

2011-03-01

The natural history of all known patients with French-Canadian Leigh disease (Saguenay-Lac-St-Jean cytochrome c oxidase deficiency, MIM220111, SLSJ-COX), the largest known cohort of patients with a genetically homogeneous, nuclear encoded congenital lactic acidosis, was studied. 55 of 56 patients were homozygous for the A354V mutation in LRPPRC. One was a genetic compound (A354V/C1277Xdel8). Clinical features included developmental delay, failure to thrive, characteristic facial appearance and, in 90% of patients, acute crises that have not previously been detailed, either metabolic (fulminant lactic acidosis) and/or neurological (Leigh syndrome and/or stroke-like episodes). Survival ranged from 5 days to >30 years. 46/56 patients (82%) died, at a median age of 1.6 years. Of 73 crises, 38 (52%) were fatal. The immediate causes of death were multiple organ failure and/or Leigh disease. Major predictors of mortality during crises (p<0.005) were hyperglycaemia, hepatic cytolysis, and altered consciousness at admission. Compared to a group of SURF1-deficient Leigh syndrome patients assembled from the literature, SLSJ-COX is distinct by the occurrence of metabolic crises, leading to earlier and higher mortality (p=0.001). SLSJ-COX is clinically distinct, with acute fatal acidotic crises on a backdrop of chronic moderate developmental delay and hyperlactataemia. Leigh syndrome is common. Stroke-like episodes can occur. The Leigh syndrome of SLSJ-COX differs from that of SURF1-related COX deficiency. SLSJ-COX has a different spectrum of associated abnormalities, acidotic crises being particularly suggestive of LRPPRC related Leigh syndrome. Even among A354V homozygotes, pronounced differences in survival and severity occur, showing that other genetic and/or environmental factors can influence outcome.

Large landslides induced by the 2008 Wenchuan earthquake and their precursory gravitational slope deformation

NASA Astrophysics Data System (ADS)

Chigira, Masahiro; Wu, Xiyong; Wang, Gonghui; Uchida, Osamu

2010-05-01

2008 Wenchuan earthquake induced numerous large landslides, of which many large landslides had been preceded by gravitational deformation. The deformation could be detected by linear depressions and convex slopes observed on satellite images taken before the earthquake. Ground truth survey after the earthquake also found the gravitational deformation of rocks, which could be predated before the earthquake. The Daguanbao landslide, the largest landslide induced by this earthquake, occurred on a slope of bedded carbonate rocks. The area of the landslide, based on measurements made from the ALOS/PRISM images is 7.353 km2. Its volume is estimated to be 0.837 km3 based on the comparison of the PRISM data and the SRTM DEM. It had an open V-shaped main scarp, of which one linear part was along a high angle fault and the other was approximately parallel to the bedding strike. The upslope edge of the V-shaped main scarp was observed as 2- km long linear depressions along the ridge-top on satellite image before the landslide. This indicates that this slope had been already destabilized and small movement occurred along the bedding planes and along the fault before the event. The Wenchuan earthquake pulled the final trigger of this landslide. The major sliding surface was along the bedding plane, which was observed to dip 35° or slightly gentler. It was warped convex upward and the beds were fractured, which suggests that the beds were slightly buckled before the landslide. This deformation may correspond to the formation of the linear depression. The Tangjiashan landslide in Beichuan, which produced the largest landslide dam during the earthquake, occurred on a dip slope of shale and slate. The geologic structures of the landslide was observed on the side flanks of the landslide, which indicated that the beds had been buckled gravitationally beforehand and the sliding surface was made along the bedding plane and a joint parallel to the slope surface. The buckling deformation was brittle deformation and different from the ductile deformation that accompanied the nearby tectonic folds. The Formosat II and SPOT images on Google Earth indicate that this landslide occurred on a slope with spur-crossing depressions with upslope-convex traces. This topography also indicates that this slope had been deforming by slow rock creep before the earthquake. The gravitational deformation before the landslides above stated appeared as linear depressions or spur-crossing depressions, both of which expressed small displacement in comparison with the size of the whole slope. This may suggest that they were at a critical state just before the catastrophic failure.

Effects of tubing length and coupling method on hearing threshold and real-ear to coupler difference measures.

PubMed

Gustafson, Samantha; Pittman, Andrea; Fanning, Robert

2013-06-01

This tutorial demonstrates the effects of tubing length and coupling type (i.e., foam tip or personal earmold) on hearing threshold and real-ear-to-coupler difference (RECD) measures. Hearing thresholds from 0.25 kHz through 8 kHz are reported at various tubing lengths for 28 normal-hearing adults between the ages of 22 and 31 years. RECD values are reported for 14 of the adults. All measures were made with an insert earphone coupled to a standard foam tip and with an insert earphone coupled to each participant's personal earmold. Threshold and RECD measures obtained with a personal earmold were significantly different from those obtained with a foam tip on repeated measures analyses of variance. One-sample t tests showed these differences to vary systematically with increasing tubing length, with the largest average differences (7-8 dB) occurring at 4 kHz. This systematic examination demonstrates the equal and opposite effects of tubing length on threshold and acoustic measures. Specifically, as tubing length increased, sound pressure level in the ear canal decreased, affecting both hearing thresholds and the real-ear portion of the RECDs. This demonstration shows that when the same coupling method is used to obtain the hearing thresholds and RECD, equal and accurate estimates of real-ear sound pressure level are obtained.

Age, sex, and setting factors and labor force in athletic training.

PubMed

Kahanov, Leamor; Eberman, Lindsey E

2011-01-01

Occupation or occupational setting shifts might be occurring in the athletic training profession, and differences between sexes might exist; however, little evidence exists to confirm this supposition. To evaluate trends in male and female athletic training employment patterns in terms of age and occupational setting. Cross-sectional study. We requested demographic data from the National Athletic Trainers' Association (October 27, 2009) and obtained frequency totals of members by sex across the occupational life span by occupational setting. Our sample included 18 571 athletic trainers employed in the 3 largest classifications of occupational settings within the profession: college or university, clinical, and secondary school. We calculated frequencies and percentages to determine demographic and descriptive data. We analyzed the data using an analysis of variance to identify the differences between sexes across age and setting. We observed trends in occupational setting and sex across ages 22 to 67 years. We identified differences between sexes across the ages 22 to 67 years (F(1,18569) = 110818.080, P < .001, η(2) = .068) and across occupational settings (F(1,18569) = 61.908, P < .001, η(2) = .003), noting a marked decline in female athletic trainers in the workforce beginning around age 28 years and an increase in male athletic trainers in the secondary school setting beginning around their middle to late 40s. We observed differences at the intercept between setting and sex (F(1,18569) = 63529.344, P < .001, η(2) = .845), which were greater when observed across the ages (F(1,18569) = 23566787.642, P < .001, η(2) = .939). We identified differences between sexes across settings and ages in addition to an overall decrease in the workforce among all professionals. A marked decline in female athletic trainers occurred at age 28 years, yet the male population increased at the secondary school level, suggesting a setting shift. Burnout, fatigue, pay scale, and a misunderstanding of professional culture and job duties might influence the exodus or shift in athletic training.

Uncertainty in coal property valuation in West Virginia: A case study

USGS Publications Warehouse

Hohn, M.E.; McDowell, R.R.

2001-01-01

Interpolated grids of coal bed thickness are being considered for use in a proposed method for taxation of coal in the state of West Virginia (United States). To assess the origin and magnitude of possible inaccuracies in calculated coal tonnage, we used conditional simulation to generate equiprobable realizations of net coal thickness for two coals on a 7 1/2 min topographic quadrangle, and a third coal in a second quadrangle. Coals differed in average thickness and proportion of original coal that had been removed by erosion; all three coals crop out in the study area. Coal tonnage was calculated for each realization and for each interpolated grid for actual and artificial property parcels, and differences were summarized as graphs of percent difference between tonnage calculated from the grid and average tonnage from simulations. Coal in individual parcels was considered minable for valuation purposes if average thickness in each parcel exceeded 30 inches. Results of this study show that over 75% of the parcels are classified correctly as minable or unminable based on interpolation grids of coal bed thickness. Although between 80 and 90% of the tonnages differ by less than 20% between interpolated values and simulated values, a nonlinear conditional bias might exist in estimation of coal tonnage from interpolated thickness, such that tonnage is underestimated where coal is thin, and overestimated where coal is thick. The largest percent differences occur for parcels that are small in area, although because of the small quantities of coal in question, bias is small on an absolute scale for these parcels. For a given parcel size, maximum apparent overestimation of coal tonnage occurs in parcels with an average coal bed thickness near the minable cutoff of 30 in. Conditional bias in tonnage for parcels having a coal thickness exceeding the cutoff by 10 in. or more is constant for two of the three coals studied, and increases slightly with average thickness for the third coal. ?? 2001 International Association for Mathematical Geology.

What predicts the strength of simultaneous color contrast?

PubMed Central

Ratnasingam, Sivalogeswaran; Anderson, Barton L.

2017-01-01

The perceived color of a uniform image patch depends not only on the spectral content of the light that reaches the eye but also on its context. One of the most extensively studied forms of context dependence is a simultaneous contrast display: a center-surround display containing a homogeneous target embedded in a homogenous surround. A number of models have been proposed to account for the chromatic transformations of targets induced by such surrounds, but they were typically derived in the restricted context of experiments using achromatic targets with surrounds that varied along the cardinal axes of color space. There is currently no theoretical consensus that predicts the target color that produces the largest perceived color difference for two arbitrarily chosen surround colors, or what surround would give the largest color induction for an arbitrarily chosen target. Here, we present a method for assessing simultaneous contrast that avoids some of the methodological issues that arise with nulling and matching experiments and diminishes the contribution of temporal adaption. Observers were presented with pairs of center-surround patterns and ordered them from largest to smallest in perceived dissimilarity. We find that the perceived difference for two arbitrarily chosen surrounds is largest when the target falls on the line connecting the two surrounds in color space. We also find that the magnitude of induction is larger for larger differences between chromatic targets and surrounds of the same hue. Our results are consistent with the direction law (Ekroll & Faul, 2012b), and with a generalization of Kirschmann's fourth law, even for viewing conditions that do not favor temporal adaptation. PMID:28245494

Genome of Phaeocystis globosa virus PgV-16T highlights the common ancestry of the largest known DNA viruses infecting eukaryotes

PubMed Central

Santini, Sebastien; Jeudy, Sandra; Bartoli, Julia; Poirot, Olivier; Lescot, Magali; Abergel, Chantal; Barbe, Valérie; Wommack, K. Eric; Noordeloos, Anna A. M.; Brussaard, Corina P. D.; Claverie, Jean-Michel

2013-01-01

Large dsDNA viruses are involved in the population control of many globally distributed species of eukaryotic phytoplankton and have a prominent role in bloom termination. The genus Phaeocystis (Haptophyta, Prymnesiophyceae) includes several high-biomass-forming phytoplankton species, such as Phaeocystis globosa, the blooms of which occur mostly in the coastal zone of the North Atlantic and the North Sea. Here, we report the 459,984-bp-long genome sequence of P. globosa virus strain PgV-16T, encoding 434 proteins and eight tRNAs and, thus, the largest fully sequenced genome to date among viruses infecting algae. Surprisingly, PgV-16T exhibits no phylogenetic affinity with other viruses infecting microalgae (e.g., phycodnaviruses), including those infecting Emiliania huxleyi, another ubiquitous bloom-forming haptophyte. Rather, PgV-16T belongs to an emerging clade (the Megaviridae) clustering the viruses endowed with the largest known genomes, including Megavirus, Mimivirus (both infecting acanthamoeba), and a virus infecting the marine microflagellate grazer Cafeteria roenbergensis. Seventy-five percent of the best matches of PgV-16T–predicted proteins correspond to two viruses [Organic Lake phycodnavirus (OLPV)1 and OLPV2] from a hypersaline lake in Antarctica (Organic Lake), the hosts of which are unknown. As for OLPVs and other Megaviridae, the PgV-16T sequence data revealed the presence of a virophage-like genome. However, no virophage particle was detected in infected P. globosa cultures. The presence of many genes found only in Megaviridae in its genome and the presence of an associated virophage strongly suggest that PgV-16T shares a common ancestry with the largest known dsDNA viruses, the host range of which already encompasses the earliest diverging branches of domain Eukarya. PMID:23754393

Foreshock triggering of the 1 April 2014 Mw 8.2 Iquique, Chile, earthquake

NASA Astrophysics Data System (ADS)

Herman, Matthew W.; Furlong, Kevin P.; Hayes, Gavin P.; Benz, Harley M.

2016-08-01

On April 1st, 2014, a Mw 8.2 (U.S. Geological Survey moment magnitude) earthquake occurred in the subduction zone offshore northern Chile. In the two weeks leading up to the earthquake, a sequence of foreshocks, starting with a Mw 6.7 earthquake on March 16th and including three more Mw 6.0+ events, occurred predominantly south of the April 1st mainshock epicenter and up-dip of the area of significant slip during the mainshock. Using earthquake locations and source parameters derived in a previous study (Hayes et al., 2014) and a Coulomb failure stress change analysis of these events, we assess in detail the hypothesis that the earthquakes occurred as a cascading sequence, each event successively triggering the next, ultimately triggering the rupture of the mainshock. Following the initial Mw 6.7 event, each of the three largest foreshocks (Mw 6.4, 6.2 and 6.3), as well as the hypocenter of the mainshock, occurred in a region of positive Coulomb stress change produced by the preceding events, indicating these events were brought closer to failure by the prior seismicity. In addition, we reexamine the possibility that aseismic slip occurred and what role it may have played in loading the plate boundary. Using horizontal GPS displacements from along the northern Chile coast prior to the mainshock, we find that the foreshock seismicity alone likely does not account for the observed signals. We perform a grid search for the location and magnitude of an aseismic slip patch that can account for the difference between observed signals and foreshock-related displacement, and find that a slow slip region with slip corresponding to a Mw ∼ 6.8 earthquake located coincident with or up-dip of the foreshock seismicity can best explain this discrepancy. Additionally, such a slow slip region positively loads the mainshock hypocentral area, enhancing the positive loading produced by the foreshock seismicity.

Statistical Aspects of X-Class Halo and Non-Halo Events, 1996-2014

NASA Technical Reports Server (NTRS)

Wilson, Robert M.

2016-01-01

Of the 166 X-class events that occurred during the interval 1996-2014, 80 had associations with halo events, 68 had no associations with halo events, and 18 occurred during LASCO (Large Angle and Spectrometric COronagraph) data gaps. Both the duration and location of the X-class halo events proved to be statistically important parameters with respect to the geo-effectiveness of the events. Forty-four of the 80 X-class halo events occurred within 45 degrees of the Sun's central meridian and 47 of the 80 had duration greater than or equal to 30 minutes, whereas only 28 of the 68 X-class non-halo events occurred within 45 degrees of the Sun's central meridian (2 events have unknown location) and 22 of the 68 had duration greater than or equal to 30 minutes. Ignoring the 4 largest X-class flares greater than or equal to X4.0 during the LASCO data gaps, 17 of the remaining 20 were associated with halo events, and 14 of the 17 had at least one geo-magnetically disturbed day (Ap (i.e. NOAA's Ap* (ApStar)index: the major magnetic storms going back to 1932) greater than or equal to 25 nanotesias) within 1-5 days following the X-class halo event. Based on the hourly Dst (Disturbance storm time) index, the most geo-effective X-class halo event during the interval 1996-2014 was that of an X1.7 flare that occurred on 2001 March 29 at 0957, having an hourly Disturbance storm time minimum equal to minus 387 nanotesias. On average, the X-class halo events (80 events) were found to have a mean duration (42 minutes) slightly longer than the mean duration (29 minutes) of the X-class non-halo events (68 events) with the difference in the means being statistically important at the 1 percent level of significance.

Empirical relationships between instrumental ground motions and observed intensities for two great Chilean subduction zone earthquakes

NASA Astrophysics Data System (ADS)

Cilia, M. G.; Baker, L. M.

2015-12-01

We determine empirical relationships between instrumental peak ground motions and observed intensities for two great Chilean subduction earthquakes: the 2010 Mw8.8 Maule earthquake and the 2014 Mw8.2 Iquique earthquake. Both occurred immediately offshore on the primary plate boundary interface between the Nazca and South America plates. They are among the largest earthquakes to be instrumentally recorded; the 2010 Maule event is the second largest earthquake to produce strong motion recordings. Ground motion to intensity conversion equations (GMICEs) are used to reconstruct the distribution of shaking for historical earthquakes by using intensities estimated from contemporary accounts. Most great (M>8) earthquakes, like these, occur within subduction zones, yet few GMICEs exist for subduction earthquakes. It is unclear whether GMICEs developed for active crustal regions, such as California, can be scaled up to the large M of subduction zone events, or if new data sets must be analyzed to develop separate subduction GMICEs. To address this question, we pair instrumental peak ground motions, both acceleration (PGA) and velocity (PGV), with intensities derived from onsite surveys of earthquake damage made in the weeks after the events and internet-derived felt reports. We fit a linear predictive equation between the geometric mean of the maximum PGA or PGV of the two horizontal components and intensity, using linear least squares. We use a weighting scheme to express the uncertainty of the pairings based on a station's proximity to the nearest intensity observation. The intensity data derived from the onsite surveys is a complete, high-quality investigation of the earthquake damage. We perform the computations using both the survey data and community decimal intensities (CDI) calculated from felt reports volunteered by citizens (USGS "Did You Feel It", DYFI) and compare the results. We compare the GMICEs we developed to the most widely used GMICEs from California and central US earthquakes, and global earthquakes. Existing GMICEs consistently over-predict intensity for these two subduction events. This may be a regional difference, or a magnitude-dependent effect. Currently, however, there is not enough data from these great subduction earthquakes to prefer one interpretation over the other.

Reducing the data-deficiency of threatened European habitats: Spatial variation of sabellariid worm reefs and associated fauna in the Sicily Channel, Mediterranean Sea.

PubMed

Bertocci, Iacopo; Badalamenti, Fabio; Lo Brutto, Sabrina; Mikac, Barbara; Pipitone, Carlo; Schimmenti, Eugenia; Vega Fernández, Tomás; Musco, Luigi

2017-09-01

Biogenic reefs, such as those produced by tube-dwelling polychaetes of the genus Sabellaria, are valuable marine habitats which are a focus of protection according to European legislation. The achievement of this goal is potentially hindered by the lack of essential empirical data, especially in the Mediterranean Sea. This study addresses some of the current knowledge gaps by quantifying and comparing multi-scale patterns of abundance and distribution of two habitat-forming species (Sabellaria alveolata and S. spinulosa) and their associated fauna along 190 km of coast on the Italian side of the Sicily Channel. While the abundance of the two sabellariids and the total number of associated taxa did not differ at any of the examined scales (from tens of centimetres to tens-100 of kilometres), the structure (composition in terms of both the identity and the relative abundance of constituting taxa) of the associated fauna and the abundance of several taxa (the polychaetes Eulalia ornata, Syllis pulvinata, S. garciai, Nereis splendida and Arabella iricolor, and the amphipods Apolochus neapolitanus, Tethylembos viguieri and Caprella acanthifera) varied among locations established ∼50-100 km apart. Syllis pulvinata also showed significant variation between sites (hundreds of metres apart), analogously to the other syllid polychaetes S. armillaris and S. gracilis, the nereidid polychaete Nereis rava, and the amphipod Gammaropsis ulrici. The largest variance of S. spinulosa, of the structure of the whole associated fauna and of 56% of taxa analysed individually occurred at the scale of replicates (metres apart), while that of the dominant bio-constructor S. alveolata and of 25% of taxa occurred at the scale of sites. The remaining 19% and the total richness of taxa showed the largest variance at the scale of locations. Present findings contribute to meet a crucial requirement of any future effective protection strategy, i.e., identifying relevant scales of variation to be included in protection schemes aiming at preserving representative samples not only of target habitats and organisms, but also of the processes driving such variability. Copyright © 2017 Elsevier Ltd. All rights reserved.

Low Stress Drop Swarm Events in the Yilgarn Craton, Western Australia

NASA Astrophysics Data System (ADS)

Allen, T. I.; Cummins, P. R.; Leonard, M.; Collins, C. D.

2004-12-01

Since September 2001, the small rural community of Burakin, southwest Western Australia, has been at the focus of seismic activity in Australia. In the six month period following commencement of seismicity, some 18,000 events had occurred, the largest of which having a moment magnitude of M 4.6. At the onset of activity, Geoscience Australia made a concerted effort to deploy a temporary seismic network in the region. The primary objective of this network was to collect high-quality strong-motion data for use in attenuation studies. Levels of seismicity near Burakin have decreased significantly since the 2001-02 swarm, however the region continues to experience a few small earthquakes per month. Earthquake source and path parameters are evaluated for a subset of 67 earthquakes. The dataset comprises some 375 seismograph and accelerograph records for events of magnitude M 2.3-4.6, including strong-motion data for seven earthquakes of M 4.0 and greater recorded at hypocentral distances less than 10 km. Source parameters are evaluated from far-field displacement spectra. Average corner frequencies are typically quite low, chiefly ranging between 2-3 Hz for events M 3.0 and above. Given the small variability in corner frequency, stress drop is observed to increase with magnitude, from very low values of 0.04 MPa to 18 MPa for the largest events in the catalogue. The stress drops for lower magnitude events (M < 4.0) are typically lower than those obtained for southeastern Australian earthquakes of similar seismic moment. Since corner frequency is not observed to vary significantly with seismic moment, it is thought that the spectral content of shallow, small swarm events and consequently, the stress drop, is characteristically different to that of isolated intraplate earthquakes. We suggest that the larger events may be faulting previously unfractured rock or healed fault asperities, while the smaller events are adjustment events or aftershocks and occur on recently faulted surfaces. The work described has provided a useful framework for the development of regional ground-motion relations for Western Australia and will enable a better understanding of the mechanisms driving intraplate seismicity.

Assessing whether the 2017 Mw 5.4 Pohang earthquake in South Korea was an induced event

NASA Astrophysics Data System (ADS)

Kim, Kwang-Hee; Ree, Jin-Han; Kim, YoungHee; Kim, Sungshil; Kang, Su Young; Seo, Wooseok

2018-06-01

The moment magnitude (Mw) 5.4 Pohang earthquake, the most damaging event in South Korea since instrumental seismic observation began in 1905, occurred beneath the Pohang geothermal power plant in 2017. Geological and geophysical data suggest that the Pohang earthquake was induced by fluid from an enhanced geothermal system (EGS) site, which was injected directly into a near-critically stressed subsurface fault zone. The magnitude of the mainshock makes it the largest known induced earthquake at an EGS site.

A new species of Lonchophylla Thomas (Chiroptera: Phyllostomidae) from Ecuador

USGS Publications Warehouse

Albuja V., Luis; Gardner, Alfred L.

2005-01-01

We describe Lonchophylla orcesi, sp. nov., from the Choco, a region of high biotic diversity, endemism, and rainfall along the western Andean slopes and Pacific lowlands of Colombia and Ecuador. One of the largest known Lonchophylla, it occurs sympatrically with at least two other species of Lonchophylla including the similar, but somewhat smaller L. robusta. We also recognize L. concava as a Middle American Province species distinct from L. mordax of Brazil and Bolivia on the basis of cranial and dental features.

Solar Flares with some Flair

NASA Image and Video Library

2016-07-23

The Sun produced three M-class (medium-sized) flares in less than 13 hours and the third one had an interesting flourish at the end (July 22-23, 2016). These were the largest flares the Sun had produced this year. The first two flares occurred in quick succession. The third one (see the still taken at 5:38 UT on the 23rd), besides the familiar bright flash of a flare, also spewed out into space a curving string of plasma. http://photojournal.jpl.nasa.gov/catalog/PIA17912

Properties of fiber reinforced plastics about static and dynamic loadings

NASA Astrophysics Data System (ADS)

Kudinov, Vladimir V.; Korneeva, Natalia V.

2016-05-01

A method for investigation of impact toughness of anisotropic polymer composite materials (reinforced plastics) with the help of CM model sample in the configuration of microplastic (micro plastic) and impact pendulum-type testing machine under static and dynamic loadings has been developed. The method is called "Break by Impact" (Impact Break IB). The estimation of impact resistance CFRP by this method showed that an increase in loading velocity ~104 times the largest changes occurs in impact toughness and deformation ability of a material.

The Pocatello Valley, Idaho, earthquake

USGS Publications Warehouse

Rogers, A. M.; Langer, C.J.; Bucknam, R.C.

1975-01-01

A Richter magnitude 6.3 earthquake occurred at 8:31 p.m mountain daylight time on March 27, 1975, near the Utah-Idaho border in Pocatello Valley. The epicenter of the main shock was located at 42.094° N, 112.478° W, and had a focal depth of 5.5 km. This earthquake was the largest in the continental United States since the destructive San Fernando earthquake of February 1971. The main shock was preceded by a magnitude 4.5 foreshock on March 26. 

Ranavirus outbreaks in amphibian populations of northern Idaho

USGS Publications Warehouse

Russell, Danelle M.; Goldberg, Caren S.; Sprague, Laura; Waits, Lisette P.; Green, D. Earl; Schuler, Krysten L.; Rosenblum, Erica Bree

2011-01-01

Ranavirus outbreaks, caused by pathogens in the genus Ranavirus (Family Iridoviridae), were the largest single cause of reported amphibian mass mortality events in the United States from 1996–2001 (Green et al. 2002). Mortality events associated with ranaviruses have been documented on five continents and throughout the latitudes and elevations where amphibians occur (Gray et al. 2009). However, the threat of ranaviruses to amphibian and reptile populations in specific regions is still largely unknown (Chinchar 2002; Gray et al. 2009).

Discovery of the Largest Historic Silicic Submarine Eruption

NASA Astrophysics Data System (ADS)

Carey, Rebecca J.; Wysoczanski, Richard; Wunderman, Richard; Jutzeler, Martin

2014-05-01

It was likely twice the size of the renowned Mount St. Helens eruption of 1980 and perhaps more than 10 times bigger than the more recent 2010 Eyjafjallajökull eruption in Iceland. However, unlike those two events, which dominated world news headlines, in 2012 the daylong submarine silicic eruption at Havre volcano in the Kermadec Arc, New Zealand (Figure 1a; ~800 kilometers north of Auckland, New Zealand), passed without fanfare. In fact, for a while no one even knew it had occurred.

Loss of largest and oldest individuals of the Montpellier snake correlates with recent warming in the southeastern Iberian Peninsula

PubMed Central

Feriche, Mónica; Alaminos, Esmeralda; Pleguezuelos, Juan M

2017-01-01

Abstract The effects of climate change on organisms are now being extensively studied in many different taxa. However, the variation in body size, usually shrinkage in response to increasing temperature, has received little attention regarding to reptiles. During past periods of global warming, many organisms shrank in size, and current evidence and experiments manipulating temperature have shown a biomass decrease in some organisms with increasing temperatures. Here we test whether the body size of the Montpellier snake Malpolon monspessulanus from the southeastern Iberian Peninsula is changing and correlated with the increasing temperature in this region during a 39-year period (1976–2014). We measured the snout–vent length (SVL) of vouchers in scientific collections to check for trends in adult body size at the population level in relation with temperature, while controlling for the age of the individuals (estimated by skeletochronology, n =141). Given the great ontogenetic variation in body size of the study species, we categorized age in 3 classes: “young adults” (under 5 years old), “intermediate adults” (from 5 to 7 years old), and “old adults” (from 8 to 14 years old). By means of linear mixed models, we found a negative relationship between SVL of “old adults” and average annual temperature in the region during the lifetime of each individual. Our results indicate that largest and oldest individuals of the Montpellier Snake, that is, males because of strong sexual size dimorphism in this species, disappeared from the study population, and suggest that it occurred in response to rising environmental temperature. PMID:29492021

Do resource utilization and clinical measures still vary across dialysis chains after controlling for the local practices of facilities and physicians?

PubMed

Hirth, Richard A; Turenne, Marc N; Wheeler, John R C; Ma, Yu; Messana, Joseph M

2010-08-01

Because of adverse survival effects, anemia management and financial incentives to increase doses of erythropoiesis-stimulating agents (ESAs) have been controversial. Prior studies showed more aggressive anemia management in dialysis facilities owned by for-profit chains, but have been criticized for not accounting for practices of individual physicians and facilities. To improve understanding of how dialysis practices and resource utilization are influenced by physicians, facilities, and chains. Mixed models with chain fixed effects and facility and physician random effects. Medicare hemodialysis patients in 2004. A total of 234,158 patients, 3995 facilities, 4838 physicians, and 7 chain classifications were included. Spending per session for dialysis-related services billed separately from the dialysis treatment and for ESAs. Achievement of hematocrit (HCT) and urea reduction ratio (URR) targets. Of the 4 largest for-profit chains, 3 had higher resource use than independents, with differences up to $17.92 higher ESA/session. Utilization was positively associated with achieving target HCT. Despite incurring lower costs, patients treated by a large nonprofit chain were as likely as patients of independents to achieve the HCT target. The largest chains were more likely than independents to achieve the URR target. Substantial variation occurred across physicians and facilities, and adjustment for chain only modestly decreased this variation. Chains' methods of influencing practices were not directly observed. Chains appear to have the ability to implement protocols that shift practices, but not the ability to substantially reduce local variation. Assertions that chain effects found by earlier studies were spurious are not supported.

Evidence for protection of targeted reef fish on the largest marine reserve in the Caribbean

PubMed Central

Pina-Amargós, Fabián; González-Sansón, Gaspar; Martín-Blanco, Félix

2014-01-01

Marine reserves can restore fish abundance and diversity in areas impacted by overfishing, but the effectiveness of reserves in developing countries where resources for enforcement are limited, have seldom been evaluated. Here we assess whether the establishment in 1996 of the largest marine reserve in the Caribbean, Gardens of the Queen in Cuba, has had a positive effect on the abundance of commercially valuable reef fish species in relation to neighboring unprotected areas. We surveyed 25 sites, including two reef habitats (reef crest and reef slope), inside and outside the marine reserve, on five different months, and over a one-and-a-half year period. Densities of the ten most frequent, highly targeted, and relatively large fish species showed a significant variability across the archipelago for both reef habitats that depended on the month of survey. These ten species showed a tendency towards higher abundance inside the reserve in both reef habitats for most months during the study. Average fish densities pooled by protection level, however, showed that five out of these ten species were at least two-fold significantly higher inside than outside the reserve at one or both reef habitats. Supporting evidence from previously published studies in the area indicates that habitat complexity and major benthic communities were similar inside and outside the reserve, while fishing pressure appeared to be homogeneous across the archipelago before reserve establishment. Although poaching may occur within the reserve, especially at the boundaries, effective protection from fishing was the most plausible explanation for the patterns observed. PMID:24688853

Coral reef fishes exhibit beneficial phenotypes inside marine protected areas

PubMed Central

Carroll, Jessica; Rynerson, Kristen W.; Matthews, Danielle F.; Turingan, Ralph G.

2018-01-01

Human fishing effort is size-selective, preferentially removing the largest individuals from harvested stocks. Intensive, size-specific fishing mortality induces directional shifts in phenotypic frequencies towards the predominance of smaller and earlier-maturing individuals, which are among the primary causes of declining fish biomass. Fish that reproduce at smaller size and younger age produce fewer, smaller, and less viable larvae, severely reducing the reproductive capacity of harvested populations. Marine protected areas (MPAs) are extensively utilized in coral reefs for fisheries management, and are thought to mitigate the impacts of size-selective fishing mortality and supplement fished stocks through larval export. However, empirical evidence of disparities in fitness-relevant phenotypes between MPAs and adjacent fished reefs is necessary to validate this assertion. Here, we compare key life-history traits in three coral-reef fishes (Acanthurus nigrofuscus, Ctenochaetus striatus, and Parupeneus multifasciatus) between MPAs and fished reefs in the Philippines. Results of our analyses support previous hypotheses regarding the impacts of MPAs on phenotypic traits. Asymptotic length (Linf) and growth rates (K) differed between conspecifics in MPAs and fished reefs, with protected populations exhibiting phenotypes that are known to confer higher fecundity. Additionally, populations demonstrated increases in length at 50% maturity (L50) inside MPAs compared to adjacent areas, although age at 50% maturity (A50) did not appear to be impacted by MPA establishment. Shifts toward advantageous phenotypes were most common in the oldest and largest MPAs, but occurred in all of the MPAs examined. These results suggest that MPAs may provide protection against the impacts of size-selective harvest on life-history traits in coral-reef fishes. PMID:29470525

Loss of largest and oldest individuals of the Montpellier snake correlates with recent warming in the southeastern Iberian Peninsula.

PubMed

López-Calderón, Cosme; Feriche, Mónica; Alaminos, Esmeralda; Pleguezuelos, Juan M

2017-12-01

The effects of climate change on organisms are now being extensively studied in many different taxa. However, the variation in body size, usually shrinkage in response to increasing temperature, has received little attention regarding to reptiles. During past periods of global warming, many organisms shrank in size, and current evidence and experiments manipulating temperature have shown a biomass decrease in some organisms with increasing temperatures. Here we test whether the body size of the Montpellier snake Malpolon monspessulanus from the southeastern Iberian Peninsula is changing and correlated with the increasing temperature in this region during a 39-year period (1976-2014). We measured the snout-vent length (SVL) of vouchers in scientific collections to check for trends in adult body size at the population level in relation with temperature, while controlling for the age of the individuals (estimated by skeletochronology, n  =141). Given the great ontogenetic variation in body size of the study species, we categorized age in 3 classes: "young adults" (under 5 years old), "intermediate adults" (from 5 to 7 years old), and "old adults" (from 8 to 14 years old). By means of linear mixed models, we found a negative relationship between SVL of "old adults" and average annual temperature in the region during the lifetime of each individual. Our results indicate that largest and oldest individuals of the Montpellier Snake, that is, males because of strong sexual size dimorphism in this species, disappeared from the study population, and suggest that it occurred in response to rising environmental temperature.

Dryland climate change: Recent progress and challenges

NASA Astrophysics Data System (ADS)

Huang, J.; Li, Y.; Fu, C.; Chen, F.; Fu, Q.; Dai, A.; Shinoda, M.; Ma, Z.; Guo, W.; Li, Z.; Zhang, L.; Liu, Y.; Yu, H.; He, Y.; Xie, Y.; Guan, X.; Ji, M.; Lin, L.; Wang, S.; Yan, H.; Wang, G.

2017-09-01

Drylands are home to more than 38% of the world's population and are one of the most sensitive areas to climate change and human activities. This review describes recent progress in dryland climate change research. Recent findings indicate that the long-term trend of the aridity index (AI) is mainly attributable to increased greenhouse gas emissions, while anthropogenic aerosols exert small effects but alter its attributions. Atmosphere-land interactions determine the intensity of regional response. The largest warming during the last 100 years was observed over drylands and accounted for more than half of the continental warming. The global pattern and interdecadal variability of aridity changes are modulated by oceanic oscillations. The different phases of those oceanic oscillations induce significant changes in land-sea and north-south thermal contrasts, which affect the intensity of the westerlies and planetary waves and the blocking frequency, thereby altering global changes in temperature and precipitation. During 1948-2008, the drylands in the Americas became wetter due to enhanced westerlies, whereas the drylands in the Eastern Hemisphere became drier because of the weakened East Asian summer monsoon. Drylands as defined by the AI have expanded over the last 60 years and are projected to expand in the 21st century. The largest expansion of drylands has occurred in semiarid regions since the early 1960s. Dryland expansion will lead to reduced carbon sequestration and enhanced regional warming. The increasing aridity, enhanced warming, and rapidly growing population will exacerbate the risk of land degradation and desertification in the near future in developing countries.

Normal-faulting slip maxima and stress-drop variability: a geological perspective

USGS Publications Warehouse

Hecker, S.; Dawson, T.E.; Schwartz, D.P.

2010-01-01

We present an empirical estimate of maximum slip in continental normal-faulting earthquakes and present evidence that stress drop in intraplate extensional environments is dependent on fault maturity. A survey of reported slip in historical earthquakes globally and in latest Quaternary paleoearthquakes in the Western Cordillera of the United States indicates maximum vertical displacements as large as 6–6.5 m. A difference in the ratio of maximum-to-mean displacements between data sets of prehistoric and historical earthquakes, together with constraints on bias in estimates of mean paleodisplacement, suggest that applying a correction factor of 1.4±0.3 to the largest observed displacement along a paleorupture may provide a reasonable estimate of the maximum displacement. Adjusting the largest paleodisplacements in our regional data set (~6 m) by a factor of 1.4 yields a possible upper-bound vertical displacement for the Western Cordillera of about 8.4 m, although a smaller correction factor may be more appropriate for the longest ruptures. Because maximum slip is highly localized along strike, if such large displacements occur, they are extremely rare. Static stress drop in surface-rupturing earthquakes in the Western Cordillera, as represented by maximum reported displacement as a fraction of modeled rupture length, appears to be larger on normal faults with low cumulative geologic displacement (<2 km) and larger in regions such as the Rocky Mountains, where immature, low-throw faults are concentrated. This conclusion is consistent with a growing recognition that structural development influences stress drop and indicates that this influence is significant enough to be evident among faults within a single intraplate environment.

Evidence for protection of targeted reef fish on the largest marine reserve in the Caribbean.

PubMed

Pina-Amargós, Fabián; González-Sansón, Gaspar; Martín-Blanco, Félix; Valdivia, Abel

2014-01-01

Marine reserves can restore fish abundance and diversity in areas impacted by overfishing, but the effectiveness of reserves in developing countries where resources for enforcement are limited, have seldom been evaluated. Here we assess whether the establishment in 1996 of the largest marine reserve in the Caribbean, Gardens of the Queen in Cuba, has had a positive effect on the abundance of commercially valuable reef fish species in relation to neighboring unprotected areas. We surveyed 25 sites, including two reef habitats (reef crest and reef slope), inside and outside the marine reserve, on five different months, and over a one-and-a-half year period. Densities of the ten most frequent, highly targeted, and relatively large fish species showed a significant variability across the archipelago for both reef habitats that depended on the month of survey. These ten species showed a tendency towards higher abundance inside the reserve in both reef habitats for most months during the study. Average fish densities pooled by protection level, however, showed that five out of these ten species were at least two-fold significantly higher inside than outside the reserve at one or both reef habitats. Supporting evidence from previously published studies in the area indicates that habitat complexity and major benthic communities were similar inside and outside the reserve, while fishing pressure appeared to be homogeneous across the archipelago before reserve establishment. Although poaching may occur within the reserve, especially at the boundaries, effective protection from fishing was the most plausible explanation for the patterns observed.

Large differences in reanalyses of diabatic heating in the tropical upper troposphere and lower stratosphere

NASA Astrophysics Data System (ADS)

Wright, J. S.; Fueglistaler, S.

2013-09-01

We present the time mean heat budgets of the tropical upper troposphere (UT) and lower stratosphere (LS) as simulated by five reanalysis models: the Modern-Era Retrospective Analysis for Research and Applications (MERRA), European Reanalysis (ERA-Interim), Climate Forecast System Reanalysis (CFSR), Japanese 25-yr Reanalysis and Japan Meteorological Agency Climate Data Assimilation System (JRA-25/JCDAS), and National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis 1. The simulated diabatic heat budget in the tropical UTLS differs significantly from model to model, with substantial implications for representations of transport and mixing. Large differences are apparent both in the net heat budget and in all comparable individual components, including latent heating, heating due to radiative transfer, and heating due to parameterised vertical mixing. We describe and discuss the most pronounced differences. Discrepancies in latent heating reflect continuing difficulties in representing moist convection in models. Although these discrepancies may be expected, their magnitude is still disturbing. We pay particular attention to discrepancies in radiative heating (which may be surprising given the strength of observational constraints on temperature and tropospheric water vapour) and discrepancies in heating due to turbulent mixing (which have received comparatively little attention). The largest differences in radiative heating in the tropical UTLS are attributable to differences in cloud radiative heating, but important systematic differences are present even in the absence of clouds. Local maxima in heating and cooling due to parameterised turbulent mixing occur in the vicinity of the tropical tropopause.

Anatomy of biologically mediated opal speleothems in the World's largest sandstone cave: Cueva Charles Brewer, Chimantá Plateau, Venezuela

NASA Astrophysics Data System (ADS)

Aubrecht, R.; Brewer-Carías, Ch.; Šmída, B.; Audy, M.; Kováčik, Ľ.

2008-01-01

Siliceous speleothems can be formed in sandstone caves. Recently, opal "biospeleothems" have been found in the World's largest cave in Precambrian sandstones on the Chimantá Tepui in Venezuela. The speleothems, although reminiscent of normal stalactites and stalagmites from limestone caves, are in fact large microbialites. More than a dozen forms were distinguished, but they share a common structure and origin. They consist of two main types: 1. fine-laminated columnar stromatolite formed by silicified filamentous microbes (either heterotrophic filamentous bacteria or cyanobacteria) and 2. a porous peloidal stromatolite formed by Nostoc-type cyanobacteria. The first type usually forms the central part and the second type, the outer part, of speleothems. Fungal hyphae, metazoan and plant remains also subordinately contribute to speleothem construction. The speleothems occur out of the reach of flowing water; the main source of silica is the condensed cave moisture which is the main dissolution-reprecipitation agent. Speleothems which originated by encrustation of spider threads are unique.

Evolution of king crabs from hermit crab ancestors

NASA Astrophysics Data System (ADS)

Cunningham, C. W.; Blackstone, N. W.; Buss, L. W.

1992-02-01

KING crabs (Family Lithodidae) are among the world's largest arthropods, having a crab-like morphology and a strongly calcified exoskeleton1-6. The hermit crabs, by contrast, have depended on gastropod shells for protection for over 150 million years5,7. Shell-living has constrained the morphological evolution of hermit crabs by requiring a decalcified asymmetrical abdomen capable of coiling into gastropod shells and by preventing crabs from growing past the size of the largest available shells1-6. Whereas reduction in shell-living and acquisition of a crab-like morphology (carcinization) has taken place independently in several hermit crab lineages, and most dramatically in king crabs1-6, the rate at which this process has occurred was entirely unknown2,7. We present molecular evidence that king crabs are not only descended from hermit crabs, but are nested within the hermit crab genus Pagurus. We estimate that loss of the shell-living habit and the complete carcinization of king crabs has taken between 13 and 25 million years.

Eruptive Trio Seen by STEREO

NASA Image and Video Library

2017-12-08

NASA image acquired May 1, 2010. As an active region rotated into view, it blew out three relatively small eruptions over about two days (Apr. 30 - May 2) as STEREO (Ahead) observed in extreme UV light. The first one was the largest and exhibited a pronounced twisting motion (shown in the still from May 1, 2010). The plasma, not far above the Sun's surface in these images, is ionized Helium heated to about 60,000 degrees. Note, too, the movement of plasma flowing along magnetic field lines that extend out beyond and loop back into the Sun's surface. Such activity occurs every day and is part of the dynamism of the changing Sun. Credit: NASA/GSFC/STEREO To learn more about STEREO go to: soho.nascom.nasa.gov/home.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Fifteen Years of Operation at NASA's National Transonic Facility with the World's Largest Adjustable Speed Drive

NASA Technical Reports Server (NTRS)

Sydnor, George H.; Bhatia, Ram; Krattiger, Hansueli; Mylius, Justus; Schafer, D.

2012-01-01

In September 1995, a project was initiated to replace the existing drive line at NASA's most unique transonic wind tunnel, the National Transonic Facility (NTF), with a single 101 MW synchronous motor driven by a Load Commutated Inverter (LCI). This Adjustable Speed Drive (ASD) system also included a custom four-winding transformer, harmonic filter, exciter, switch gear, control system, and feeder cable. The complete system requirements and design details have previously been presented and published [1], as well as the commissioning and acceptance test results [2]. The NTF was returned to service in December 1997 with the new drive system powering the fan. Today, this installation still represents the world s largest horizontal single motor/drive combination. This paper describes some significant events that occurred with the drive system during the first 15 years of service. These noteworthy issues are analyzed and root causes presented. Improvements that have substantially increased the long term viability of the system are given.

Optimization Strategies for Single-Stage, Multi-Stage and Continuous ADRs

NASA Technical Reports Server (NTRS)

Shirron, Peter J.

2014-01-01

Adiabatic Demagnetization Refrigerators (ADR) have many advantages that are prompting a resurgence in their use in spaceflight and laboratory applications. They are solid-state coolers capable of very high efficiency and very wide operating range. However, their low energy storage density translates to larger mass for a given cooling capacity than is possible with other refrigeration techniques. The interplay between refrigerant mass and other parameters such as magnetic field and heat transfer points in multi-stage ADRs gives rise to a wide parameter space for optimization. This paper first presents optimization strategies for single ADR stages, focusing primarily on obtaining the largest cooling capacity per stage mass, then discusses the optimization of multi-stage and continuous ADRs in the context of the coordinated heat transfer that must occur between stages. The goal for the latter is usually to obtain the largest cooling power per mass or volume, but there can also be many secondary objectives, such as limiting instantaneous heat rejection rates and producing intermediate temperatures for cooling of other instrument components.

Remembering the best and worst of times: memories for extreme outcomes bias risky decisions.

PubMed

Madan, Christopher R; Ludvig, Elliot A; Spetch, Marcia L

2014-06-01

When making decisions on the basis of past experiences, people must rely on their memories. Human memory has many well-known biases, including the tendency to better remember highly salient events. We propose an extreme-outcome rule, whereby this memory bias leads people to overweight the largest gains and largest losses, leading to more risk seeking for relative gains than for relative losses. To test this rule, in two experiments, people repeatedly chose between fixed and risky options, where the risky option led equiprobably to more or less than did the fixed option. As was predicted, people were more risk seeking for relative gains than for relative losses. In subsequent memory tests, people tended to recall the extreme outcome first and also judged the extreme outcome as having occurred more frequently. Across individuals, risk preferences in the risky-choice task correlated with these memory biases. This extreme-outcome rule presents a novel mechanism through which memory influences decision making.

The melting Himalayas: cascading effects of climate change on water, biodiversity, and livelihoods.

PubMed

Xu, Jianchu; Grumbine, R Edward; Shrestha, Arun; Eriksson, Mats; Yang, Xuefei; Wang, Yun; Wilkes, Andreas

2009-06-01

The Greater Himalayas hold the largest mass of ice outside polar regions and are the source of the 10 largest rivers in Asia. Rapid reduction in the volume of Himalayan glaciers due to climate change is occurring. The cascading effects of rising temperatures and loss of ice and snow in the region are affecting, for example, water availability (amounts, seasonality), biodiversity (endemic species, predator-prey relations), ecosystem boundary shifts (tree-line movements, high-elevation ecosystem changes), and global feedbacks (monsoonal shifts, loss of soil carbon). Climate change will also have environmental and social impacts that will likely increase uncertainty in water supplies and agricultural production for human populations across Asia. A common understanding of climate change needs to be developed through regional and local-scale research so that mitigation and adaptation strategies can be identified and implemented. The challenges brought about by climate change in the Greater Himalayas can only be addressed through increased regional collaboration in scientific research and policy making. ©2009 Society for Conservation Biology.

Flood of May 19, 1990, along Perry Creek in Plymouth and Woodbury counties, Iowa

USGS Publications Warehouse

Eash, D.A.

1996-01-01

A water-surface-elevation profile and peak discharges for the flood of May 19, 1990, along Perry Creek in Plymouth and Woodbury Counties, Iowa, are presented in this report. The peak discharge for the May 19,1990, flood on Perry Creek at 38th Street, Sioux City (06600000) is the second largest flood-peak discharge recorded at the streamflow-gaging station for the period 1939-95. The peak discharge for May 19, 1990, of 8,670 cubic feet per second, is approximately equal to the 35-year recurrence-interval discharge. The report provides information on flood stages and discharges and floodflow frequencies for streamflow-gaging stations in the Perry Creek Basin using flood information collected during 1939-95. Information on temporary bench marks and reference points established in the Perry Creek Basin during 1990-93 is also included in the report. A flood history describes rainfall conditions for the three largest floods that occurred during 1939-95 (July 1944, September 1949, and May 1990).

Strong motion observations and recordings from the great Wenchuan Earthquake

USGS Publications Warehouse

Li, X.; Zhou, Z.; Yu, H.; Wen, R.; Lu, D.; Huang, M.; Zhou, Y.; Cu, J.

2008-01-01

The National Strong Motion Observation Network System (NSMONS) of China is briefly introduced in this paper. The NSMONS consists of permanent free-field stations, special observation arrays, mobile observatories and a network management system. During the Wenchuan Earthquake, over 1,400 components of acceleration records were obtained from 460 permanent free-field stations and three arrays for topographical effect and structural response observation in the network system from the main shock, and over 20,000 components of acceleration records from strong aftershocks occurred before August 1, 2008 were also obtained by permanent free-field stations of the NSMONS and 59 mobile instruments quickly deployed after the main shock. The strong motion recordings from the main shock and strong aftershocks are summarized in this paper. In the ground motion recordings, there are over 560 components with peak ground acceleration (PGA) over 10 Gal, the largest being 957.7 Gal. The largest PGA recorded during the aftershock exceeds 300 Gal. ?? 2008 Institute of Engineering Mechanics, China Earthquake Administration and Springer-Verlag GmbH.

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

Hlaing Myat Thu; Department of Medical Research, Ziwaka Road, Yangon 11191; Lowry, Kym

Between 1996 and 1998, two clades (B and C; genotype I) of dengue virus type 1 (DENV-1) appeared in Myanmar (Burma) that were new to that location. Between 1998 and 2000, a third clade (A; genotype III) of DENV-1, which had been circulating at that locality for at least 25 years, became extinct. These changes preceded the largest outbreak of dengue recorded in Myanmar, in 2001, in which more than 95% of viruses recovered from patients were DENV-1, but where the incidence of severe disease was much less than in previous years. Phylogenetic analyses of viral genomes indicated that themore » two new clades of DENV-1 did not arise from the, now extinct, clade A viruses nor was the extinction of this clade due to differences in the fitness of the viral populations. Since the extinction occurred during an inter-epidemic period, we suggest that it was due to a stochastic event attributable to the low rate of virus transmission in this interval.« less

Streamflow gain and loss of selected streams in northern Arkansas

USGS Publications Warehouse

Freiwald, David A.

1987-01-01

This map shows streamflow gain and loss measurements (seepage runs) on the Crooked, Osage, and Spavinaw Creeks, and Illinois, Kings, Mulberry, Spring, and Strawberry Rivers during the low-flow conditions from September 1982 to October 1984. Data indicated that streamflow gains and losses resulted from differences in lithology of the predominately carbonate rocks and from the presence of faults. The Kings and Strawberry Rivers and Osage Creek were gaining streams throughout their length, however wastewater discharges precluded an accurate determination on Osage Creek. Crooked and Spavinaw Creeks and the Illinois, Spring, and Mulberry Rivers generally were gaining streams throughout most of their lengths although short losing reaches were identified. The largest gains in streamflow generally occurred were Mississippian formation predominated near the streams. Faults that intersected the stream channels primarily were responsible for streamflow losses. The specific conductance of water increased in the stream reaches that had the most significant streamflow gains. The specific conductance of water in tributaries was generally higher than that in larger streams. (Author 's abstract)