What advice is given to newly qualified doctors on Twitter? An analysis of #TipsForNewDocs tweets.

PubMed

Rashid, Mohammed Ahmed; McKechnie, Doug; Gill, Deborah

2018-07-01

Twitter is a social media platform on which users post very brief messages that can be rapidly communicated across wide geographical areas and audiences. Many doctors use Twitter for personal as well as professional communications and networking. The #TipsForNewDocs hashtag is used on Twitter to give advice to newly qualified doctors as they commence their careers. This study explores the nature and focus of such advice. An analysis of Twitter activity containing the #TipsForNewDocs hashtag was performed using Symplur health care analytics software. Tweets sent during a peak 48-hour period in 2016 (immediately preceding the first day of work for newly qualified UK doctors) were studied. The geographical locations and professional backgrounds of participants were categorised and the content of tweets was subjected to thematic analysis. During 1 and 2 August 2016, 661 unique #TipsForNewDocs tweets were posted. A total of 621 (94.0%) were posted by people in the UK; 522 (79.0%) were posted by doctors, and the remainder by allied health care professionals and patients. The majority of included tweets focused on aspects of professional development, improving personal or professional knowledge, particularly tacit knowledge, and developing 'know-how'. These aspects of professional knowledge have previously been described as fundamental to professional education and training. However, a significant subset of tweets focused on accelerating socialisation into the profession, an essential step in joining a professional community. The tweets relating to socialisation were often humorous and colloquial in nature. Despite their brief and often jocular nature, #TipsForNewDocs tweets provided meaningful advice for newcomers to the profession, often focusing on tacit learning and professional socialisation. Hashtag-driven enquiries can be a valuable and time-efficient way of accessing and sharing tacitly held knowledge. Social media content analysis can provide valuable insights

DOC quantity and quality in northeastern USA catchments

NASA Astrophysics Data System (ADS)

Shanley, J. B.; Sebestyen, S. D.; Aiken, G.; Pellerin, B. A.

2011-12-01

At the Sleepers River Research Watershed in Vermont we have studied interactions of dissolved organic carbon (DOC) cycling and hydrological processes for nearly 20 years to determine how and when DOC is transported through the landscape. Stream DOC concentration in this cool temperate forested catchment varies from ~1 to ~15 mg L-1 and is transport-limited; concentrations increase with increasing flow, even under the wettest conditions, suggesting shifting but non-depletable sources. Specific UV absorbance (SUVA) also increases consistently with flow. Source strength does vary seasonally, however, evidenced by higher DOC for a given flow during autumn leaf fall relative to spring snowmelt. Recent high-frequency optical sensor measurements have revealed fine-scale structure in the temporal DOC pattern not possible from discrete sampling. We observe a consistent counterclockwise hysteresis and diurnal cycles with seasonally variable amplitude. In this presentation we infer DOC sources and processes through analysis of antecedent moisture conditions and concurrent variations in nitrate, dissolved organic nitrogen, and SUVA. With sensors and sampling in place at several other research catchments, we are investigating the similarity of patterns across the northeastern USA.

Degradation potentials of dissolved organic carbon (DOC) from thawed permafrost peat

PubMed Central

Panneer Selvam, Balathandayuthabani; Lapierre, Jean-François; Guillemette, Francois; Voigt, Carolina; Lamprecht, Richard E.; Biasi, Christina; Christensen, Torben R.; Martikainen, Pertti J.; Berggren, Martin

2017-01-01

Global warming can substantially affect the export of dissolved organic carbon (DOC) from peat-permafrost to aquatic systems. The direct degradability of such peat-derived DOC, however, is poorly constrained because previous permafrost thaw studies have mainly addressed mineral soil catchments or DOC pools that have already been processed in surface waters. We incubated peat cores from a palsa mire to compare an active layer and an experimentally thawed permafrost layer with regard to DOC composition and degradation potentials of pore water DOC. Our results show that DOC from the thawed permafrost layer had high initial degradation potentials compared with DOC from the active layer. In fact, the DOC that showed the highest bio- and photo-degradability, respectively, originated in the thawed permafrost layer. Our study sheds new light on the DOC composition of peat-permafrost directly upon thaw and suggests that past estimates of carbon-dioxide emissions from thawed peat permafrost may be biased as they have overlooked the initial mineralization potential of the exported DOC. PMID:28378792

Comparing Stream DOC Fluxes from Sensor- and Sample-Based Approaches

NASA Astrophysics Data System (ADS)

Shanley, J. B.; Saraceno, J.; Aulenbach, B. T.; Mast, A.; Clow, D. W.; Hood, K.; Walker, J. F.; Murphy, S. F.; Torres-Sanchez, A.; Aiken, G.; McDowell, W. H.

2015-12-01

DOC transport by streamwater is a significant flux that does not consistently show up in ecosystem carbon budgets. In an effort to quantify stream DOC flux, we analyzed three to four years of high-frequency in situ fluorescing dissolved organic matter (FDOM) concentrations and turbidity measured by optical sensors at the five diverse forested and/or alpine headwater sites of the U.S. Geological Survey (USGS) Water, Energy, and Biogeochemical Budgets (WEBB) program. FDOM serves as a proxy for DOC. We also took discrete samples over a range of hydrologic conditions, using both manual weekly and automated event-based sampling. After compensating FDOM for temperature effects and turbidity interference - which was successful even at the high-turbidity Luquillo, PR site -- we evaluated the DOC-FDOM relation based on discrete sample DOC analyses matched to corrected FDOM at the time of sampling. FDOM was a moderately robust predictor of DOC, with r2 from 0.60 to more than 0.95 among sites. We then formed continuous DOC time series by two independent approaches: (1) DOC predicted from FDOM; and (2) the composite method, based on modeled DOC from regression on stream discharge, season, air temperature, and time, forcing the model to observations and adjusting modeled concentrations between observations by linearly-interpolated model residuals. DOC flux from each approach was then computed directly as concentration times discharge. DOC fluxes based on the sensor approach were consistently greater than the sample-based approach. At Loch Vale, CO (2.5 years) and Panola Mountain GA (1 year), the difference was 5-17%. At Sleepers River, VT (3 years), preliminary differences were greater than 20%. The difference is driven by the highest events, but we are investigating these results further. We will also present comparisons from Luquillo, PR, and Allequash Creek, WI. The higher sensor-based DOC fluxes could result from their accuracy during hysteresis, which is difficult to model

The Comparison of Different Heterotrophic Bacteria on the Decomposition of DOC molecule

NASA Astrophysics Data System (ADS)

Xie, R.; Zheng, Q.; Jiao, N.

2016-02-01

Marine dissolved organic carbon (DOC) pool is one of the largest reservoirs of organic carbon on Earth. Heterotrophic bacteria are the primary biotic force regulating the fate of marine DOC. Comparison of genomic data, microbes belonging to different clades have diverse DOC molecule utilization genes. That's give us a hint that different microbial groups may have their own pattern to decompose DOC, biosynthesize diverse DOC molecule and contribute to the in situ DOC reservoirs in the ocean. The interaction between marine microbes and DOC molecule is hotspots in current research. We will choose some important microbial groups (e.g., Roseobacter, Altermonas, Halomonas, SAR11 and CFB) to identify their contribution to environmental DOC pool and their specific recalcitrant DOC component using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Combined with the composition of hydrolases, lyases and ligases in their genomes, we try to establish a linkage between the specific DOC composition and microbial genetic information. Future more the environmental metagenomic data would help us understand the relationship between the endemic DOC composition and microbial communities in the environment.

Diel fluctuations of viscosity-driven riparian inflow affect streamflow DOC concentration

NASA Astrophysics Data System (ADS)

Schwab, Michael P.; Klaus, Julian; Pfister, Laurent; Weiler, Markus

2018-04-01

Diel fluctuations of stream water DOC concentrations are generally explained by a complex interplay of different instream processes. We measured the light absorption spectrum of water and DOC concentrations in situ and with high frequency by means of a UV-Vis spectrometer during 18 months at the outlet of a forested headwater catchment in Luxembourg (0.45 km2). We generally observed diel DOC fluctuations with a maximum in the afternoon during days that were not affected by rainfall-runoff events. We identified an increased inflow of terrestrial DOC to the stream in the afternoon, causing the DOC maxima in the stream. The terrestrial origin of the DOC was derived from the SUVA-254 (specific UV absorbance at 254 nm) index, which is a good indicator for the aromaticity of DOC. In the studied catchment, the most likely process that can explain the diel DOC input variations towards the stream is the so-called viscosity effect. The water temperature in the upper parts of the saturated riparian zone is increasing during the day, leading to a lower viscosity and therefore a higher hydraulic conductivity. Consequently, more water from areas that are rich in terrestrial DOC passes through the saturated riparian zone and contributes to streamflow in the afternoon. We believe that not only diel instream processes, but also viscosity-driven diel fluctuations of terrestrial DOC input should be considered to explain diel DOC patterns in streams.

Understanding DOC Mobilization Dynamics Through High Frequency Measurements in a Headwater Catchment

NASA Astrophysics Data System (ADS)

Werner, B.; Musolff, A.; Lechtenfeld, O.; de Rooij, G. H.; Fleckenstein, J. H.

2017-12-01

Increasing dissolved organic carbon (DOC) exports from headwater catchments impact the quality of downstream waters and pose challenges to water supply. The importance of riparian zones for DOC export from catchments in humid, temperate climates has generally been acknowledged, but the hydrological controls and biogeochemical factors that govern mobilization of DOC from riparian zones remain elusive. By analyzing high-frequency time series of UV-VIS based water quality we therefore aim at a better understanding on temporal dynamics of DOC mobilization and exports. In a first step a one year high frequency (15 minutes) data set from a headwater catchment in the Harz Mountains (Germany) was systematically analyzed for event-based patterns in DOC concentrations. Here, a simplistic linear model was generated to explain DOC concentration level and variability in the stream. Furthermore, spectral (e.g. slopes and SUVA254) and molecular (FT-ICR-MS) characterization of DOC was used to fingerprint in-stream DOC during events. Continuous DOC concentrations were best predicted (R², NSE = 0.53) by instantaneous discharge (Q) and antecede wetness conditions of the last 30 days (AWC30 = Precip.30/PET30) as well as mean air temperature (Tmean30) and mean discharge (Qmean30) of the preceding 30 days. Analyses of 36 events revealed seasonal trends for the slope, intercept and R² of linear log(DOC)-log(Q) regressions that can be best explained by the mean air temperature of the preceding 15 days. Continuously available optical DOC quality parameters SUVA254 and spectral slope (275 nm - 295 nm) systematically changed with shifts in discharge and in DOC concentration. This is underlined by selected FT-ICR-MS measurements indicating higher DOC aromaticity and oxygen content at high flow conditions. The change of DOC quality parameters during events indicate a shift in the activated source zones: DOC with a different quality was mobilized during high flow conditions when higher

Inverse coupling of DOC and nitrate export from soils and streams

NASA Astrophysics Data System (ADS)

Goodale, Christine

2013-04-01

Over the last two decades, nitrate concentrations in surface waters have decreased across the Northeastern United States and parts of northern Europe. Many hypotheses have been proposed to explain this decrease, but the cause remains unclear. One control may be associated with increasing abundance of dissolved organic carbon (DOC), which in turn may be a result of soil recovery from acidification. Compared across catchments, surface water NO3- decreases sharply with increasing DOC concentration. Here, we used measurements of soil and solution nitrate, DOC, and their isotopic composition (13C-DOC, 15N- and 18O-NO3) to test several related hypotheses that changing acidification affects the release of DOC and bio-available DOC (bDOC) from soil, and that variation in stocks of soil C and release of bDOC partly control NO3- export from forested catchments in New York State, USA. We examined whether DOC and NO3- are both driven by soil C processes that produce inverse coupling at the scale of soil cores as well as across catchments, through comparison of soil and surface water chemistry across nine catchments selected from long-term monitoring networks in the Catskill and Adirondack Mountains. In addition, we conducted a series of soil core leaching experiments to examine the role of acidification and recovery in driving the net production of DOC and NO3- from soils. Over 8 months, soil cores were leached biweekly with simulated rainfall solutions of varying pH (3.6 to 7.0) from additions of H2SO4, CaCO3 and NaOH. These experiments did not yield a pH-induced change in DOC quantity, but did show a change in DOC quality, in that acidified cores released more bio-available DOC with less depleted 13C-DOC than cores with experimentally increased pH. All cores leached substantial amounts of nitrate. Together, these lab- and field comparisons are being used to identify the role of soil production and consumption processes in driving cross-watershed differences in DOC and NO3

AmeriFlux US-SP3 Slashpine-Donaldson-mid-rot- 12yrs

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

Martin, Tim

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site US-SP3 Slashpine-Donaldson-mid-rot- 12yrs. Site Description - Slash pine planted end of 1989 early 1990. Gholz and Clark, 2002. Agric. Forest Meteo. 112, 87 - 102; Ckark et al., 2004. Ecological Applications, 14, 1154 - 1171.

AmeriFlux US-SP1 Slashpine-Austin Cary- 65yrs nat regen

DOE Data Explorer

Martin, Tim [University of Florida

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site US-SP1 Slashpine-Austin Cary- 65yrs nat regen. Site Description - The ACMF site is a 67 hectare naturally regenerated Pinus palustris and Pinus elliottii mixed stand.

Acid-induced changes in DOC quality in an experimental whole-lake manipulation

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

Donahue, W.F.; Schindler, D.W.; Page, S.J.

1998-10-01

Fluorescence analyses of archived water samples were used to typify dissolved organic carbon (DOC) quality in experimentally acidified lakes and reference lakes at the Experimental Lakes Area, in northwestern Ontario. Carbon-specific DOC fluorescence (CSF) during peak acidification was 40--50% of that for a high-DOC reference lake and similar to a low-DOC reference lake. Reference lakes showed similar but smaller decreases in CSF during several years of prolonged drought in the late 1980s. During the 1990s, recovery from acidification resulted in increased CSF, whereas reference lakes remained unchanged during the same time period. In addition to causing decreased [DOC], acidification causesmore » changes in fluorescence-peak geometry that indicate a switch in DOC quality from allochthonous to autochthonous-like during acidification. The acid-induced change in DOC quality was likely due to increased chemical oxidation or precipitation of the UV-absorbent aromatic portions of allochthonous DOC molecules, leaving more UV-transparent aliphatic chains. The change in the nature of DOC following acidification and drought may have an important role in physical, biological, and chemical processes within these lakes. With recovery from acidification, DOC quality has also recovered.« less

The Earth System Documentation (ES-DOC) Software Process

NASA Astrophysics Data System (ADS)

Greenslade, M. A.; Murphy, S.; Treshansky, A.; DeLuca, C.; Guilyardi, E.; Denvil, S.

2013-12-01

Earth System Documentation (ES-DOC) is an international project supplying high-quality tools & services in support of earth system documentation creation, analysis and dissemination. It is nurturing a sustainable standards based documentation eco-system that aims to become an integral part of the next generation of exa-scale dataset archives. ES-DOC leverages open source software, and applies a software development methodology that places end-user narratives at the heart of all it does. ES-DOC has initially focused upon nurturing the Earth System Model (ESM) documentation eco-system and currently supporting the following projects: * Coupled Model Inter-comparison Project Phase 5 (CMIP5); * Dynamical Core Model Inter-comparison Project (DCMIP); * National Climate Predictions and Projections Platforms Quantitative Evaluation of Downscaling Workshop. This talk will demonstrate that ES-DOC implements a relatively mature software development process. Taking a pragmatic Agile process as inspiration, ES-DOC: * Iteratively develops and releases working software; * Captures user requirements via a narrative based approach; * Uses online collaboration tools (e.g. Earth System CoG) to manage progress; * Prototypes applications to validate their feasibility; * Leverages meta-programming techniques where appropriate; * Automates testing whenever sensibly feasible; * Streamlines complex deployments to a single command; * Extensively leverages GitHub and Pivotal Tracker; * Enforces strict separation of the UI from underlying API's; * Conducts code reviews.

Modeling nonlinear responses of DOC transport in boreal catchments in Sweden

NASA Astrophysics Data System (ADS)

Kasurinen, Ville; Alfredsen, Knut; Ojala, Anne; Pumpanen, Jukka; Weyhenmeyer, Gesa A.; Futter, Martyn N.; Laudon, Hjalmar; Berninger, Frank

2016-07-01

Stream water dissolved organic carbon (DOC) concentrations display high spatial and temporal variation in boreal catchments. Understanding and predicting these patterns is a challenge with great implications for water quality projections and carbon balance estimates. Although several biogeochemical models have been used to estimate stream water DOC dynamics, model biases common during both rain and snow melt-driven events. The parsimonious DOC-model, K-DOC, with 10 calibrated parameters, uses a nonlinear discharge and catchment water storage relationship including soil temperature dependencies of DOC release and consumption. K-DOC was used to estimate the stream water DOC concentrations over 5 years for eighteen nested boreal catchments having total area of 68 km2 (varying from 0.04 to 67.9 km2). The model successfully simulated DOC concentrations during base flow conditions, as well as, hydrological events in catchments dominated by organic and mineral soils reaching NSEs from 0.46 to 0.76. Our semimechanistic model was parsimonious enough to have all parameters estimated using statistical methods. We did not find any clear differences between forest and mire-dominated catchments that could be explained by soil type or tree species composition. However, parameters controlling slow release and consumption of DOC from soil water behaved differently for small headwater catchments (less than 2 km2) than for those that integrate larger areas of different ecosystem types (10-68 km2). Our results emphasize that it is important to account for nonlinear dependencies of both, soil temperature, and catchment water storage, when simulating DOC dynamics of boreal catchments.

Google Docs in an Out-of-Class Collaborative Writing Activity

ERIC Educational Resources Information Center

Zhou, Wenyi; Simpson, Elizabeth; Domizi, Denise Pinette

2012-01-01

Google Docs, an online word processing application, is a promising tool for collaborative learning. However, many college instructors and students lack knowledge to effectively use Google Docs to enhance teaching and learning. Goals of this study include (1) assessing the effectiveness of using Google Docs in an out-of-class collaborative writing…

Removal of terrestrial DOC in aquatic ecosystems of a temperate river network

USGS Publications Warehouse

Wollheim, W.M.; Stewart, R. J.; Aiken, George R.; Butler, Kenna D.; Morse, Nathaniel B.; Salisbury, J.

2015-01-01

Surface waters play a potentially important role in the global carbon balance. Dissolved organic carbon (DOC) fluxes are a major transfer of terrestrial carbon to river systems, and the fate of DOC in aquatic systems is poorly constrained. We used a unique combination of spatially distributed sampling of three DOC fractions throughout a river network and modeling to quantify the net removal of terrestrial DOC during a summer base flow period. We found that aquatic reactivity of terrestrial DOC leading to net loss is low, closer to conservative chloride than to reactive nitrogen. Net removal occurred mainly from the hydrophobic organic acid fraction, while hydrophilic and transphilic acids showed no net change, indicating that partitioning of bulk DOC into different fractions is critical for understanding terrestrial DOC removal. These findings suggest that river systems may have only a modest ability to alter the amounts of terrestrial DOC delivered to coastal zones.

Assessing the relative bioavailability of DOC in regional groundwater systems

USGS Publications Warehouse

Chapelle, Francis H.; Bradley, Paul M.; Journey, Celeste A.; McMahon, Peter B.

2013-01-01

It has been hypothesized that the degree to which a hyperbolic relationship exists between concentrations of dissolved organic carbon (DOC) and dissolved oxygen (DO) in groundwater may indicate the relative bioavailability of DOC. This hypothesis was examined for 73 different regional aquifers of the United States using 7745 analyses of groundwater compiled by the National Water Assessment (NAWQA) program of the U.S. Geological Survey. The relative reaction quotient (RRQ), a measure of the curvature of DOC concentrations plotted versus DO concentrations and regressed to a decaying hyperbolic equation, was used to assess the relative bioavailability of DOC. For the basalt aquifer of Oahu, Hawaii, RRQ values were low (0.0013 mM−2), reflecting a nearly random relationship between DOC and DO concentrations. In contrast, on the island of Maui, treated sewage effluent injected into a portion of the basalt aquifer resulted in pronounced hyperbolic DOC-DO behavior and a higher RRQ (142 mM−2). RRQ values for the 73 aquifers correlated positively with mean concentrations of ammonia, dissolved iron, and manganese, and correlated negatively with mean pH. This indicates that greater RRQ values are associated with greater concentrations of the final products of microbial reduction reactions. RRQ values and DOC concentrations were negatively correlated with the thickness of the unsaturated zone (UNST) and depth to the top of the screened interval. Finally, RRQ values were positively correlated with mean annual precipitation (MAP), and the highest observed RRQ values were associated with aquifers receiving MAP rates ranging between 900 and 1300 mm/year. These results are uniformly consistent with the hypothesis that the hyperbolic behavior of DOC-DO plots, as quantified by the RRQ metric, can be an indicator of relative DOC bioavailability in groundwater systems.

Dynamics, chemical properties and bioavailability of DOC in an early successional catchment

NASA Astrophysics Data System (ADS)

Risse-Buhl, U.; Hagedorn, F.; Dümig, A.; Gessner, M. O.; Schaaf, W.; Nii-Annang, S.; Gerull, L.; Mutz, M.

2013-07-01

The dynamics of dissolved organic carbon (DOC) have been intensively studied in mature ecosystems, but little is known about DOC dynamics and the significance of DOC as a substrate for microbial activity in early-successional catchments. We determined the concentration, chemical composition, source, radiocarbon age, and bioavailability of DOC along the hydrological flow path from soil solution to a downstream pond in a recently constructed catchment (Chicken Creek Catchment, Germany). Soil solution, upwelling ground water, stream water, subsurface water in an alluvial fan, and pond water all had high DOC concentrations (averages: 6.0-11.6 mg DOC L-1), despite small carbon stocks in both vegetation and soil of the catchment. Solid-state CPMAS 13C NMR of DOC in upwelling ground water revealed a higher proportion of aromatic compounds (32%) and a lower proportion of carbohydrates (33%) than in pond water (18% and 45%, respectively). The average 14C age of DOC in upwelling ground water was 2600 to 2900 yr, while organic matter of the Quaternary substrate of the catchment had a 14C age of 3000 to 16 000 yr. Both the 14C age data and 13C NMR spectra suggest that DOC partly derived from organic matter of the Quaternary substrate (about 40 to 90% of the C in the DOC), indicating that both recent and old C of the DOC can support microbial activity during early ecosystem succession. However, in a 70 day incubation experiment, only about 11% of the total DOC was found to be bioavailable. This proportion was irrespective of the water type. Origin of the microbial communities within the catchment (enriched from soil, stream sediment or pond water) also had only a marginal effect on overall DOC utilization.

Drivers of inverse DOC-nitrate loss patterns in forest soils and streams

NASA Astrophysics Data System (ADS)

Goodale, C. L.

2013-12-01

Nitrate loss from forested catchments varies greatly across sites and over time, with few reliable correlates. One of the few recurring patterns, however, is the negative nonlinear relationship that occurs regularly between surface water nitrate and dissolved organic carbon (DOC) concentrations: that is, nitrate declines sharply as DOC concentrations increase, and high nitrate levels occur only at low DOC concentrations. Several hypotheses have been proposed to explain this pattern, but its cause has remained speculative. It is likely to be driven by C- or N-limitation of biological processes such as assimilation or denitrification, but the identity of which biological process or the main landscape position of their activity are not known. We examined whether DOC and nitrate are both driven by soil C content, at scales of both soil blocks and across catchments, by measuring soil, soil extract, and surface water chemistry across nine catchments selected from long-term monitoring networks in the Catskill and Adirondack Mountains. We measured soil C and N status and solution nitrate, DOC, bioavailable DOC (bDOC), and isotopic composition (13C-DOC, 15N- and 18O-NO3) to examine whether variation in stocks of soil C partly controls DOC and nitrate loss from forested catchments in New York State. These measurements showed that surface soil C and C:N ratio together determine soil production of DOC and nitrate, reflecting assimilative demand for N by heterotrophic microbes. Yet, they also show that these processes do not produce the inverse DOC-NO3 curve observed at the catchment scale. Rather, catchment-scale DOC-nitrate patterns are more likely to be governed by the balance between excess nitrate production and its bDOC-mediated loss to denitrification.

Dynamics, chemical properties and bioavailability of DOC in an early successional catchment

NASA Astrophysics Data System (ADS)

Risse-Buhl, U.; Hagedorn, F.; Dümig, A.; Gessner, M. O.; Schaaf, W.; Nii-Annang, S.; Gerull, L.; Mutz, M.

2013-01-01

The dynamics of dissolved organic carbon (DOC) have been intensively studied in mature ecosystems, but little is known about DOC dynamics and the significance of DOC as a substrate for microbial activity in early-successional catchments. We determined the concentration, chemical composition, source, radiocarbon age, and bioavailability of DOC along the hydrological flow path from soil solution to a downstream pond in a recently constructed catchment (Chicken Creek Catchment, Germany). Soil solution, upwelling ground water, subsurface water in an alluvial fan, and pond water all had high DOC concentrations (averages of 6.0-11.6 mg DOC L-1), despite small carbon stocks in either vegetation or soil of the early-successional catchment. The mean 14C age of DOC in upwelling ground water was 2600 to 2800 yr. Solid-state CPMAS 13C NMR revealed a higher proportion of aromatic compounds (32%) and a lower proportion of carbohydrates (33%) in upwelling ground water than in pond water (18% and 45%, respectively). The 14C age and 13C NMR spectra suggest that DOC was partly mobilized from charred organic matter of the Quaternary substrate. In an experimental 70-days incubation experiment, 20% of the total DOC was found to be bioavailable, irrespective of the water type. Origin of microbial communities (enriched from soil, stream sediment or pond water) had only marginal effects on overall DOC utilization. Overall, these data suggest that the old DOC can support microbial activity during early ecosystem succession to some extent, although the largest fraction is recalcitrant DOC that is exported from the catchment once it has been mobilized.

The Earth System Documentation (ES-DOC) project

NASA Astrophysics Data System (ADS)

Murphy, S.; Greenslade, M. A.; Treshansky, A.; DeLuca, C.; Guilyardi, E.; Denvil, S.

2013-12-01

Earth System Documentation (ES-DOC) is an international project supplying high quality tools and services in support of Earth system documentation creation, analysis and dissemination. It is nurturing a sustainable standards based documentation ecosystem that aims to become an integral part of the next generation of exa-scale dataset archives. ES-DOC leverages open source software, and applies a software development methodology that places end-user narratives at the heart of all it does. ES-DOC has initially focused upon nurturing the Earth System Model (ESM) documentation eco-system. Within this context ES-DOC leverages the emerging Common Information Model (CIM) metadata standard, which has supported the following projects: ** Coupled Model Inter-comparison Project Phase 5 (CMIP5); ** Dynamical Core Model Inter-comparison Project (DCMIP-2012); ** National Climate Predictions and Projections Platforms (NCPP) Quantitative Evaluation of Downscaling Workshop (QED-2013). This presentation will introduce the project to a wider audience and will demonstrate the current production level capabilities of the eco-system: ** An ESM documentation Viewer embeddable into any website; ** An ESM Questionnaire configurable on a project by project basis; ** An ESM comparison tool reusable across projects; ** An ESM visualization tool reusable across projects; ** A search engine for speedily accessing published documentation; ** Libraries for streamlining document creation, validation and publishing pipelines.

ISACS-DOC: Monitoring and Diagnostic System for AKARI and HINODE

NASA Astrophysics Data System (ADS)

Mizutani, Mitsue; Hirose, Toshinori; Takaki, Ryoji; Honda, Hideyuki

ISACS-DOC (Intelligent Satellite Control Software-DOCtor), which is an automatic monitoring and diagnostic system for scientific satellites or spacecraft, aims to rapidly and accurately capture important changes and sign of anomaly during daily satellite operations. After three systems for deep space missions, the new generation of ISACS-DOC with a higher speed processing performance had been developed for the satellites in earth orbit, AKARI and HINODE. This paper reports on the newest ISACS-DOC about enhanced functions, operating status, and an approach to create standards to build and keep up the knowledge data base. Continuous enhancements through the actual operations are the advantage of ISACS-DOC.

Enhanced DOC removal using anion and cation ion exchange resins.

PubMed

Arias-Paic, Miguel; Cawley, Kaelin M; Byg, Steve; Rosario-Ortiz, Fernando L

2016-01-01

Hardness and DOC removal in a single ion exchange unit operation allows for less infrastructure, is advantageous for process operation and depending on the water source, could enhance anion exchange resin removal of dissolved organic carbon (DOC). Simultaneous application of cationic (Plus) and anionic (MIEX) ion exchange resin in a single contact vessel was tested at pilot and bench scales, under multiple regeneration cycles. Hardness removal correlated with theoretical predictions; where measured hardness was between 88 and 98% of the predicted value. Comparing bench scale DOC removal of solely treating water with MIEX compared to Plus and MIEX treated water showed an enhanced DOC removal, where removal was increased from 0.5 to 1.25 mg/L for the simultaneous resin application compared to solely applying MIEX resin. A full scale MIEX treatment plant (14.5 MGD) reduced raw water DOC from 13.7 mg/L to 4.90 mg/L in the treated effluent at a bed volume (BV) treatment rate of 800, where a parallel operation of a simultaneous MIEX and Plus resin pilot (10 gpm) measured effluent DOC concentrations of no greater than 3.4 mg/L, even at bed volumes of treatment 37.5% greater than the full scale plant. MIEX effluent compared to simultaneous Plus and MIEX effluent resulted in differences in fluorescence intensity that correlated to decreases in DOC concentration. The simultaneous treatment of Plus and MIEX resin produced water with predominantly microbial character, indicating the enhanced DOC removal was principally due to increased removal of terrestrially derived organic matter. The addition of Plus resin to a process train with MIEX resin allows for one treatment process to remove both DOC and hardness, where a single brine waste stream can be sent to sewer at a full-scale plant, completely removing lime chemical addition and sludge waste disposal for precipitative softening processes. Published by Elsevier Ltd.

Is the blocking of drainage channels in upland peats an effective means of reducing DOC loss at the catchment scale?

NASA Astrophysics Data System (ADS)

Turner, Kate; Worrall, Fred

2010-05-01

Only 3% of the earths land surface is covered by peatland yet boreal and subarctic peatlands store approximately 15-30% of the World's soil carbon as peat (Limpens et al. 2008). In comparison British bogs store carbon equivalent to 20 years worth of national emissions. The loss of carbon from these areas in the form of dissolved organic carbon (DOC) is increasing and it is expected to have grown by up to 40% by 2018. Extensive drainage of UK peatlands has been associated with dehydration of the peat, an increase in water colour and a loss of carbon storage. It has been considered that the blocking of these drainage channels represents a means of peat restoration and a way of reducing DOC loss. This study aims to assess the effectiveness of this drain blocking at both an individual drain scale and at a larger catchment scale. Gibson et al. (2009) considered the effects of blocking at a solely individual drain scale finding that a 20% drop in DOC export was recorded post blocking however this decrease was due to a reduction in water yield rather than a reduction in DOC concentration with the concentration record showing no significant reduction. The effect of external parameters become more pronounced as the DOC record is examined at larger scales. The catchment is an open system and water chemistry will be influence by mixing with water from other sources. Also it is likely that at some point the drains will cut across slope leading to the flow of any highly coloured water down slope, bypassing the blockages, and entering the surface waters downstream. Degradation of DOC will occur naturally downstream due to the effects of light and microbial activity. There is, consequently, a need to examine the wider effects of drain blocking at a catchment scale to ensure that what is observed for one drain transfers to the whole catchment. A series of blocked and unblocked catchments were studied in Upper Teesdale, Northern England. Drain water samples were taken at least

Effect of DOC on evaporation from small Wisconsin lakes

NASA Astrophysics Data System (ADS)

Watras, C. J.; Morrison, K. A.; Rubsam, J. L.

2016-09-01

Evaporation (E) dominates the loss of water from many small lakes, and the balance between precipitation and evaporation (P-E) often governs water levels. In this study, evaporation rates were estimated for three small Wisconsin lakes over several years using 30-min data from floating evaporation pans (E-pans). Measured E was then compared to the output of mass transfer models driven by local conditions over daily time scales. The three lakes were chosen to span a range of dissolved organic carbon (DOC) concentrations (3-20 mg L-1), a solute that imparts a dark, tea-stain color which absorbs solar energy and limits light penetration. Since the lakes were otherwise similar, we hypothesized that a DOC-mediated increase in surface water temperature would translate directly to higher rates of evaporation thereby informing climate response models. Our results confirmed a DOC effect on surface water temperature, but that effect did not translate to enhanced evaporation. Instead the opposite was observed: evaporation rates decreased as DOC increased. Ancillary data and prior studies suggest two explanatory mechanisms: (1) disproportionately greater radiant energy outflux from high DOC lakes, and (2) the combined effect of wind speed (W) and the vapor pressure gradient (es - ez), whose product [W(es - ez)] was lowest on the high DOC lake, despite very low wind speeds (<1.5 m s-1) and steep forested uplands surrounding all three lakes. Agreement between measured (E-pan) and modeled evaporation rates was reasonably good, based on linear regression results (r2: 0.6-0.7; slope: 0.5-0.7, for the best model). Rankings based on E were similar whether determined by measured or modeled criteria (high DOC < low DOC). Across the 3 lakes and 4 years, E averaged ∼3 mm d-1 (C.V. 9%), but statistically significant differences between lakes resulted in substantial differences in cumulative E that were consistent from year to year. Daily water budgets for these lakes show that inputs

Insights and issues with simulating terrestrial DOC loading of Arctic river networks

USGS Publications Warehouse

Kicklighter, David W.; Hayes, Daniel J.; McClelland, James W.; Peterson, Bruce J.; McGuire, A. David; Melillo, Jerry M.

2013-01-01

Terrestrial carbon dynamics influence the contribution of dissolved organic carbon (DOC) to river networks in addition to hydrology. In this study, we use a biogeochemical process model to simulate the lateral transfer of DOC from land to the Arctic Ocean via riverine transport. We estimate that, over the 20th century, the pan-Arctic watershed has contributed, on average, 32 Tg C/yr of DOC to river networks emptying into the Arctic Ocean with most of the DOC coming from the extensive area of boreal deciduous needle-leaved forests and forested wetlands in Eurasian watersheds. We also estimate that the rate of terrestrial DOC loading has been increasing by 0.037 Tg C/yr2 over the 20th century primarily as a result of climate-induced increases in water yield. These increases have been offset by decreases in terrestrial DOC loading caused by wildfires. Other environmental factors (CO2 fertilization, ozone pollution, atmospheric nitrogen deposition, timber harvest, agriculture) are estimated to have relatively small effects on terrestrial DOC loading to Arctic rivers. The effects of the various environmental factors on terrestrial carbon dynamics have both offset and enhanced concurrent effects on hydrology to influence terrestrial DOC loading and may be changing the relative importance of terrestrial carbon dynamics on this carbon flux. Improvements in simulating terrestrial DOC loading to pan-Arctic rivers in the future will require better information on the production and consumption of DOC within the soil profile, the transfer of DOC from land to headwater streams, the spatial distribution of precipitation and its temporal trends, carbon dynamics of larch-dominated ecosystems in eastern Siberia, and the role of industrial organic effluents on carbon budgets of rivers in western Russia.

Modelling impacts of temperature, and acidifying and eutrophying deposition on DOC trends

NASA Astrophysics Data System (ADS)

Sawicka, Kasia; Rowe, Ed; Evans, Chris; Monteith, Don; Vanguelova, Elena; Wade, Andrew; Clark, Joanna

2017-04-01

Surface water dissolved organic carbon (DOC) concentrations in large parts of the northern hemisphere have risen over the past three decades, raising concern about enhanced contributions of carbon to the atmosphere and seas and oceans. The effect of declining acid deposition has been identified as a key control on DOC trends in soil and surface waters, since pH and ionic strength affect sorption and desorption of DOC. However, since DOC is derived mainly from recently-fixed carbon, and organic matter decomposition rates are considered sensitive to temperature, uncertainty persists regarding the extent to the relative importance of different drivers that affect these upward trends. We ran the dynamic model MADOC (Model of Acidity and Soil Organic Carbon) for a range of UK soils (podzols, gleysols and peatland), for which the time-series were available, to consider the likely relative importance of decreased deposition of sulphate and chloride, accumulation of reactive N, and higher temperatures, on DOC production in different soils. Modelled patterns of DOC change generally agreed favourably with measurements collated over 10-20 years, but differed markedly between sites. While the acidifying effect of sulphur deposition appeared to be the predominant control on the observed soil water DOC trends in all the soils considered other than a blanket peat, the model suggested that over the long term, the effects of nitrogen deposition on N-limited soils may have been sufficient to elevate the DOC recovery trajectory significantly. The second most influential cause of rising DOC in the model simulations was N deposition in ecosystems that are N-limited and respond with stimulated plant growth. Although non-marine chloride deposition made some contribution to acidification and recovery, it was not amongst the main drivers of DOC change. Warming had almost no effect on modelled historic DOC trends, but may prove to be a significant driver of DOC in future via its influence

Reliability and Validity of the Dyadic Observed Communication Scale (DOCS).

PubMed

Hadley, Wendy; Stewart, Angela; Hunter, Heather L; Affleck, Katelyn; Donenberg, Geri; Diclemente, Ralph; Brown, Larry K

2013-02-01

We evaluated the reliability and validity of the Dyadic Observed Communication Scale (DOCS) coding scheme, which was developed to capture a range of communication components between parents and adolescents. Adolescents and their caregivers were recruited from mental health facilities for participation in a large, multi-site family-based HIV prevention intervention study. Seventy-one dyads were randomly selected from the larger study sample and coded using the DOCS at baseline. Preliminary validity and reliability of the DOCS was examined using various methods, such as comparing results to self-report measures and examining interrater reliability. Results suggest that the DOCS is a reliable and valid measure of observed communication among parent-adolescent dyads that captures both verbal and nonverbal communication behaviors that are typical intervention targets. The DOCS is a viable coding scheme for use by researchers and clinicians examining parent-adolescent communication. Coders can be trained to reliably capture individual and dyadic components of communication for parents and adolescents and this complex information can be obtained relatively quickly.

Assessing contribution of DOC from sediments to a drinking-water reservoir using optical profiling

USGS Publications Warehouse

Downing, Bryan D.; Bergamaschi, Brian A.; Evans, David G.; Boss, Emmanuel

2008-01-01

Understanding the sources of dissolved organic carbon (DOC) in drinking-water reservoirs is an important management issue because DOC may form disinfection by-products, interfere with disinfection, or increase treatment costs. DOC may be derived from a host of sources-algal production of DOC in the reservoir, marginal production of DOC from mucks and vascular plants at the margins, and sediments in the reservoir. The purpose of this study was to assess if release of DOC from reservoir sediments containing ferric chloride coagulant was a significant source of DOC to the reservoir. We examined the source-specific contributions of DOC using a profiling system to measure the in situ distribution of optical properties of absorption and fluorescence at various locations in the reservoir. Vertical optical profiles were coupled with discrete water samples measured in the laboratory for DOC concentration and optical properties: absorption spectra and excitation emission matrix spectra (EEMs). Modeling the in situ optical data permitted estimation of the bulk DOC profile in the reservoir as well as separation into source-specific contributions. Analysis of the source-specific profiles and their associated optical characteristics indicated that the sedimentary source of DOC to the reservoir is significant and that this DOC is labile in the reservoir. We conclude that optical profiling is a useful technique for understanding complex biogeochemical processes in a reservoir.

Holding a Post-Doctoral Position before Becoming a Faculty Member: Does It Bring Benefits for the Scholarly Enterprise?

ERIC Educational Resources Information Center

Horta, Hugo

2009-01-01

This article examines the effects that performing a post-doc early in the academic career have for the current scholarly practices of faculty members. Results show that performing a post-doc early in the academic career impacts positively the recent research output of academics, although not affecting the other faculty member's scholarly…

The Relationship Between DOC Partition Coefficient and Mineral Soil C:N Ratio

NASA Astrophysics Data System (ADS)

Aitkenhead-Peterson, J. A.; McDowell, W. H.

2001-12-01

Since our recent publication showing that soil C:N predicts DOC flux at local and global scales, an effort has been made to understand mechanisms controlling the relationship between the two variables. We have approached this at multiple scales, using soil batch experiments, soil column experiments, and long-term field manipulations. We present here the results from our batch adsorption experiment. Mineral soils from tropical (wet and moist) and temperate (coniferous and hardwood) forests were used to assess DOC adsorption by the initial mass isotherm approach. We found that the DOC partition co-efficient (m) which represents a soil's tendency to adsorb DOC is strongly and inversely related to mineral soil C:N ratio (R2 = 0.99 n = 10 p < 0.001). The intercept of the mass isotherm, or the desorption term, was positively related to mineral soil C:N ratio (R2 = 0.80 n = 10 p < 0.01), but we found that desorption of DOC was more closely correlated with equilibrium DOC concentration (R2 = 0.97 n = 10 p < 0.001) than with mineral soil C:N. The mass isotherm approach is also useful in calculating the reactive soil pool (RSP), the fraction of the soil pool of organic carbon that may be lost to leaching. The RSP was not significantly related to mineral soil C:N, but tropical soils tended to have a larger RSP than temperate soils. Although some of the tropical soils came from areas where the natural forest had been cleared, used for plantations and then abandoned, the relationship between DOC adsorption and mineral soil C:N was not compromised. Watershed soil C:N ratio is an excellent predictor of DOC export because soil C:N is related to physiochemical adsorption processes in mineral soils and biotic production of DOC in organic soil horizons. It appears that soil C:N is a relatively robust predictor of soil solution DOC concentration and surface water DOC export for ecosystems undergoing environmental stress.

Seasonal Changes of DOC Composition of Rivers in Temperate Monsoon Climates

NASA Astrophysics Data System (ADS)

Oh, N. H.; Shin, Y.; Lee, E. J.; Hur, J.

2014-12-01

The spatial and seasonal dynamics of dissolved organic carbon (DOC) composition and biodegradability were investigated for the five largest rivers in the Republic of Korea during the years 2012 - 2013 using dark incubation experiments and spectroscopic measurements, including parallel factor analysis (PARAFAC). The DOC concentrations of the rivers in relatively steep and forest-dominated basins were <~2 mg L-1, and remained relatively constant over the seasons. In contrast, those of the rivers influenced by urban and agricultural activities rose up to 5.4 mg L-1, which was decreased to ~2 mg L-1 during the summer monsoon period, indicating that increased precipitation had the effect of dilution. Among the fluorescence components, terrestrial humic-like components were dominant in all the rivers except for one, where tyrosine- or tryptophan-like compounds were the major component. However, terrestrial humic-like components became dominant in all five of the rivers after high precipitation which occurred during the monsoon season, during which ~76% of the annual precipitation was received. Considering that 64% of South Korea is forested, our results suggest that the forests could be a large source of riverine DOC, elevating the DOC loads during monsoon rainfall. Although more DOC could be degraded when DOC input increased, regardless of its sources, the percent biodegradability was reduced with increased proportions of terrestrially derived and aromatic compounds. These results suggest that the relatively stable and terrestrial humic-like compounds released during the monsoon rainfall could reduce the potential of microbial respiration of riverine DOC and evasion of river CO2 to the atmosphere, despite of the increase in the DOC load.

Re-evaluation of colorimetric Cl- data from natural waters with DOC

USGS Publications Warehouse

Norton, S.A.; Handlet, M.J.; Kahl, J.S.; Peters, N.E.

1996-01-01

Colorimetric Cl- data from natural solutions that contain dissolved organic carbon (DOC) may be biased high. We evaluated aquatic Cl- concentrations in ecosystem compartments at the Bear Brook Watershed, Maine, and from lakes in Maine, using ion chromatography and colorimetry. DOC imparts a positive interference on colorimetric Cl- results proportional to DOC concentrations at approximately 0.8 ??eq Cl-/L per mg DOC/L. The interference is not a function of Cl- concentration. The resulting bias in concentrations of Cl- may be 50% or more of typical environmental values for Cl- in areas remote from atmospheric deposition of marine aerosols. Such biased data in the literature appear to have led to spurious conclusions about recycling of Cl- by forests, the usefulness of Cl- as a conservative tracer in watershed studies, and calculations of elemental budgets, ion balance, charge density of DOC, and dry deposition factors.

Fingerprinting Dissolved Organic Carbon (DOC) Sources with Specific UV Absorbance (SUVA) and Fluorescence

NASA Astrophysics Data System (ADS)

van Verseveld, W. J.; Lajtha, K.; McDonnell, J. J.

2007-12-01

DOC is an important water quality constituent because it is an important food source for stream biota, it plays a significant role in metal toxicity and transport, and protects aquatic organisms by absorbing visible and UV light. However, sources of stream DOC and changes in DOC quality at storm and seasonal scales remain poorly understood. We characterized DOC concentrations and SUVA (as an indicator of aromaticity) at the plot, hillslope and catchment scale during and between five storm events over the period Fall 2004 until Spring 2005, in WS10, H.J. Andrews, Oregon, USA. This study site has hillslopes that issue directly into the stream. This enabled us to compare a trenched hillslope response to the stream response without the influence of a riparian zone. The main result of this study was that SUVA in addition to DOC was needed to fingerprint sources of DOC. Stream water and lateral subsurface flow showed a clockwise DOC and SUVA hysteresis pattern. Both organic horizon water and transient groundwater were characterized by high DOC concentrations and SUVA values, while DOC concentrations and SUVA values in soil water decreased with depth in the soil profile. This indicates transient groundwater was an important contributor to high DOC concentrations and SUVA values during storm events. During the falling limb of the hydrograph deep soil water and seepage groundwater based on SUVA values contributed significantly to lateral subsurface flow and stream water. Preliminary results showed that fluorescence of stream water and lateral subsurface flow continuously measured with a fluorometer was significantly related to UV-absorbance during a December storm event. Finally, SUVA of lateral subsurface flow was lower than SUVA of stream water at the seasonal scale, indicating a difference in mixing of water sources at the hillslope and catchment scale. Overall, our results show that SUVA and fluorescence are useful tracers for fingerprinting DOC sources.

Modeling rates of DOC degradation using DOM composition and hydroclimatic variables

NASA Astrophysics Data System (ADS)

Moody, C. S.; Worrall, F.

2017-05-01

The fluvial fluxes of dissolved organic carbon (DOC) from peatlands form an important part of that ecosystem's carbon cycle, contributing approximately 35% of the overall peatland carbon budget. The in-stream processes acting on the DOC, such as photodegradation and biodegradation, can lead to DOC loss and thus contribute CO2 to the atmosphere. The aim of this study was to understand what controls the rates of DOC degradation. Water samples from a headwater, peat-covered catchment, were collected over a 23 month period and analyzed for the DOC degradation rate and dissolved organic matter (DOM) composition in the context of hydroclimatic monitoring. Measures of DOM composition included 13C solid-state nuclear magnetic resonance spectroscopy, bomb calorimetry, and elemental analysis. Regression analysis showed that there was a significant role for the composition of the DOM in controlling degradation with degradation rates significantly increasing with the proportion of aldehyde and carboxylic acid functional groups but decreasing with the proportion of N-alkyl functional groups. The highest rates of DOC degradation occurred when aldehyde functionality was at its greatest and this occurred on the recession limb of storm hydrographs. Including this knowledge into models of fluvial carbon fate for an 818 km2 catchment gave an annual average DOC removal rate of 67% and 50% for total organic carbon, slightly lower than previously predicted. The compositional controls suggest that DOM is primarily being used as a ready energy source to the aquatic ecosystem rather than as a nutrient source.

G-DOC Plus - an integrative bioinformatics platform for precision medicine.

PubMed

Bhuvaneshwar, Krithika; Belouali, Anas; Singh, Varun; Johnson, Robert M; Song, Lei; Alaoui, Adil; Harris, Michael A; Clarke, Robert; Weiner, Louis M; Gusev, Yuriy; Madhavan, Subha

2016-04-30

G-DOC Plus is a data integration and bioinformatics platform that uses cloud computing and other advanced computational tools to handle a variety of biomedical BIG DATA including gene expression arrays, NGS and medical images so that they can be analyzed in the full context of other omics and clinical information. G-DOC Plus currently holds data from over 10,000 patients selected from private and public resources including Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA) and the recently added datasets from REpository for Molecular BRAin Neoplasia DaTa (REMBRANDT), caArray studies of lung and colon cancer, ImmPort and the 1000 genomes data sets. The system allows researchers to explore clinical-omic data one sample at a time, as a cohort of samples; or at the level of population, providing the user with a comprehensive view of the data. G-DOC Plus tools have been leveraged in cancer and non-cancer studies for hypothesis generation and validation; biomarker discovery and multi-omics analysis, to explore somatic mutations and cancer MRI images; as well as for training and graduate education in bioinformatics, data and computational sciences. Several of these use cases are described in this paper to demonstrate its multifaceted usability. G-DOC Plus can be used to support a variety of user groups in multiple domains to enable hypothesis generation for precision medicine research. The long-term vision of G-DOC Plus is to extend this translational bioinformatics platform to stay current with emerging omics technologies and analysis methods to continue supporting novel hypothesis generation, analysis and validation for integrative biomedical research. By integrating several aspects of the disease and exposing various data elements, such as outpatient lab workup, pathology, radiology, current treatments, molecular signatures and expected outcomes over a web interface, G-DOC Plus will continue to strengthen precision medicine research. G-DOC Plus is available

Photochemical Mineralization of Terrigenous DOC to Dissolved Inorganic Carbon in Ocean

NASA Astrophysics Data System (ADS)

Aarnos, Hanna; Gélinas, Yves; Kasurinen, Ville; Gu, Yufei; Puupponen, Veli-Mikko; Vähätalo, Anssi V.

2018-02-01

When terrigenous dissolved organic carbon (tDOC) rich in chromophoric dissolved organic matter (tCDOM) enters the ocean, solar radiation mineralizes it partially into dissolved inorganic carbon (DIC). This study addresses the amount and the rates of DIC photoproduction from tDOC and the area of ocean required to photomineralize tDOC. We collected water samples from 10 major rivers, mixed them with artificial seawater, and irradiated them with simulated solar radiation to measure DIC photoproduction and the photobleaching of tCDOM. The linear relationship between DIC photoproduction and tCDOM photobleaching was used to estimate the amount of photoproduced DIC from the tCDOM fluxes of the study rivers. Solar radiation was estimated to mineralize 12.5 ± 3.7 Tg C yr-1 (10 rivers)-1 or 18 ± 8% of tDOC flux. The irradiation experiments also approximated typical apparent spectral quantum yields for DIC photoproduction (ϕλ) over the entire lifetime of the tCDOM. Based on ϕλs and the local solar irradiances in river plumes, the annual areal DIC photoproduction rates from tDOC were calculated to range from 52 ± 4 (Lena River) to 157 ± 2 mmol C m-2 yr-1 (Mississippi River). When the amount of photoproduced DIC was divided by the areal rate, 9.6 ± 2.5 × 106 km2 of ocean was required for the photomineralization of tDOC from the study rivers. Extrapolation to the global tDOC flux yields 45 (31-58) Tg of photoproduced DIC per year in the river plumes that cover 34 (25-43) × 106 km2 of the ocean.

Drowning Mortality and Morbidity Rates in Children and Adolescents 0-19yrs: A Population-Based Study in Queensland, Australia

PubMed Central

Wallis, Belinda A.; Watt, Kerrianne; Franklin, Richard C.; Nixon, James W.; Kimble, Roy M.

2015-01-01

Objective To redress the lack of Queensland population incidence mortality and morbidity data associated with drowning in those aged 0-19yrs, and to understand survival and patient care. Design, Setting and Participants Retrospective population-based study used data linkage to capture both fatal and non-fatal drowning cases (N = 1299) among children aged 0-19years in Queensland, from 2002-2008 inclusive. Patient data were accessed from pre-hospital, emergency department, hospital admission and death data, and linked manually to collate data across the continuum of care. Main Outcome Measures Incidence rates were calculated separately by age group and gender for events resulting in death, hospital admission, and non-admission. Trends over time were analysed. Results Drowning death to survival ratio was 1:10, and two out of three of those who survived were admitted to hospital. Incidence rates for fatal and non-fatal drowning increased over time, primarily due to an increase in non-fatal drowning. There were non-significant reductions in fatal and admission rates. Rates for non-fatal drowning that did not result in hospitalisation more than doubled over the seven years. Children aged 5-9yrs and 10-14yrs incurred the lowest incidence rates 6.38 and 4.62 (expressed as per 100,000), and the highest rates were among children aged 0-4yrs (all drowning events 43.90; fatal 4.04; non-fatal 39.85–comprising admission 26.69 and non-admission 13.16). Males were over-represented in all age groups except 10-14yrs. Total male drowning events increased 44% over the seven years (P<0.001). Conclusion This state-wide data collection has revealed previously unknown incidence and survival ratios. Increased trends in drowning survival rates may be viewed as both positive and challenging for drowning prevention and the health system. Males are over-represented, and although infants and toddlers did not have increased fatality rates, they had the greatest drowning burden demonstrating

AmeriFlux US-SP4 Slashpine-Rayonier-mid-rot- 12yrs

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

Martin, Tim

This is the AmeriFlux version of the carbon flux data for the site US-SP4 Slashpine-Rayonier-mid-rot- 12yrs. Site Description - Only active for one year, the Rayonier tract site was shutdown due to a stand replacing wild fire in 1998. The tower was relocated to the Donaldson tract. The characteristics between the two mid-rotation pine plantations are nearly indistinguishable, enabling the integration of measurements made at both towers. The site information provided below follows the convention that the two sites are nearly identical.

Changes in the character of DOC in streams during storms in two Midwestern watersheds with contrasting land uses

USGS Publications Warehouse

Vidon, P.; Wagner, L.E.; Soyeux, E.

2008-01-01

Dissolved organic carbon (DOC) dynamics in streams is important, yet few studies focus on DOC dynamics in Midwestern streams during storms. In this study, stream DOC dynamics during storms in two Midwestern watersheds with contrasting land uses, the change in character of stream DOC during storms, and the usability of DOC as a hydrologic tracer in artificially drained landscapes of the Midwest are investigated. Major cation/DOC concentrations, and DOC specific UV absorbance (SUVA) and fluorescence index (FI) were monitored at 2-4 h intervals during three spring storms. Although DOC is less aromatic in the mixed land use watershed than in the agricultural watershed, land use has little impact on stream DOC concentration during storms. For both watersheds, DOC concentration follows discharge, and SUVA and FI values indicate an increase in stream DOC aromaticity and lignin content during storms. The comparison of DOC/major cation flushing dynamics indicates that DOC is mainly exported via overland flow/macropore flow. In both watersheds, the increase in DOC concentration in the streams during storms corresponds to a shift in the source of DOC from DOC originating from mineral soil layers of the soil profile at baseflow, to DOC originating from surficial soil layers richer in aromatic substances and lignin during storms. Results also suggest that DOC, SUVA and FI could be used as hydrologic tracers in artificially drained landscapes of the Midwest. These results underscore the importance of sampling streams for DOC during high flow periods in order to understand the fate of DOC in streams. ?? 2008 Springer Science+Business Media B.V.

Nonlinear and threshold-dominated runoff generation controls DOC export in a small peat catchment

NASA Astrophysics Data System (ADS)

Birkel, C.; Broder, T.; Biester, H.

2017-03-01

We used a relatively simple two-layer, coupled hydrology-biogeochemistry model to simultaneously simulate streamflow and stream dissolved organic carbon (DOC) concentrations in a small lead and arsenic contaminated upland peat catchment in northwestern Germany. The model procedure was informed by an initial data mining analysis, in combination with regression relationships of discharge, DOC, and element export. We assessed the internal model DOC processing based on stream DOC hysteresis patterns and 3-hourly time step groundwater level and soil DOC data for two consecutive summer periods in 2013 and 2014. The parsimonious model (i.e., few calibrated parameters) showed the importance of nonlinear and rapid near-surface runoff generation mechanisms that caused around 60% of simulated DOC load. The total load was high even though these pathways were only activated during storm events on average 30% of the monitoring time—as also shown by the experimental data. Overall, the drier period 2013 resulted in increased nonlinearity but exported less DOC (115 kg C ha-1 yr-1 ± 11 kg C ha-1 yr-1) compared to the equivalent but wetter period in 2014 (189 kg C ha-1 yr-1 ± 38 kg C ha-1 yr-1). The exceedance of a critical water table threshold (-10 cm) triggered a rapid near-surface runoff response with associated higher DOC transport connecting all available DOC pools and subsequent dilution. We conclude that the combination of detailed experimental work with relatively simple, coupled hydrology-biogeochemistry models not only allowed the model to be internally constrained but also provided important insight into how DOC and tightly coupled pollutants or trace elements are mobilized.

Character, quality and bioavailability of Dissolved Organic Carbon (DOC) in a boreal stream network (Invited)

NASA Astrophysics Data System (ADS)

Laudon, H.; Berggren, M.; Agren, A.; Jansson, M.

2010-12-01

The conceptual understanding of the role of terrestrially derived dissolved organic carbon (DOC) in freshwaters has been changing rapidly. While it was once considered mainly a pool of recalcitrant compounds, DOC is now better known for its interactivity and ability to affect both the biogeochemistry and ecology of streams, rivers and lakes. Here we summarize the recent work from the multi-investigatory project conducted in the Krycklan Catchment Study in Sweden with an emphasis on the spatial and temporal variability of the character and bioavailability of DOC. In total, 15 streams and their adjacent soils have been investigated. The streams cover a forest-wetland gradient, spanning from 0% to 69% wetland coverage (hence with a 100% to 31% forest cover). Lower values of the ratio between absorbance measured at 254 nm and 365 nm (A254/A365), in both soil plots and streams, indicated that wetland-derived DOC has a higher average molecular weight than forest DOC. Higher SUVA254 (DOC specific ultraviolet absorption at 254 nm) in wetland runoff indicated more aromatic DOC from wetlands than forests. In accordance, low molecular weight non-aromatic compounds such as free organic acids (OA), amino acids (AA) and carbohydrates (CH) had higher quantities in the forested streams. We have shown that a variety of the OA, AA and CH compounds can be significantly assimilated by bacteria, meeting 15-100% of the bacterial carbon demand and explaining most of the observed variance in bacterial growth efficiency. We can now also show that in small homogenous catchments, the hydrological functioning provides a first order control on the temporal variability of stream water DOC and its quality. As a consequence, streams with heterogeneous catchments undergo a temporal switch in the DOC source. In a typical boreal catchment of 10-20% wetlands, DOC originates predominantly from wetland sources during low flow conditions whereas the major source of DOC originates from forested areas of

Relative importance of multiple factors on terrestrial loading of DOC to Arctic river networks

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

Kicklighter, David W.; Hayes, Daniel J; Mcclelland, James W

2014-01-01

Terrestrial carbon dynamics influence the contribution of dissolved organic carbon (DOC) to river networks in addition to controlling carbon fluxes between the land surface and the atmosphere. In this study, we use a biogeochemical process model to simulate the lateral transfer of DOC from land to the Arctic Ocean via riverine transport. We estimate that the pan-arctic watershed has contributed, on average, 32 Tg C/yr of DOC to the Arctic Ocean over the 20th century with most coming from the extensive area of boreal deciduous needle-leaved forests and forested wetlands in Eurasian watersheds. We also estimate that the rate ofmore » terrestrial DOC loading has been increasing by 0.037 Tg C/yr2 over the 20th century primarily as a result of increases in air temperatures and precipitation. These increases have been partially compensated by decreases in terrestrial DOC loading caused by wildfires. Other environmental factors (CO2 fertilization, ozone pollution, atmospheric nitrogen deposition, timber harvest, agriculture) are estimated to have relatively small effects on terrestrial DOC loading to arctic rivers. The effects of the various environmental factors on terrestrial carbon dynamics have both compensated and enhanced concurrent effects on hydrology to influence terrestrial DOC loading. Future increases in riverine DOC concentrations and export may occur from warming-induced increases in terrestrial DOC production associated with enhanced microbial metabolism and the exposure of additional organic matter from permafrost degradation along with decreases in water yield associated with warming-induced increases in evapotranspiration. Improvements in simulating terrestrial DOC loading to pan-arctic rivers in the future will require better information on the spatial distribution of precipitation and its temporal trends, carbon dynamics of larch-dominated ecosystems in eastern Siberia, and the role of industrial organic effluents on carbon budgets of rivers in

Web-based Loansome Doc, librarians, and end users: results from a survey of the Southeast Region.

PubMed

Paden, S L; Batson, A L; Wallace, R L

2001-07-01

The study examines how Loansome Doc services are implemented and used by libraries in the Southeast Region and describe end users' experiences with and attitudes toward Loansome Doc. 251 active DOCLINE libraries and 867 Loansome Doc users were surveyed. Roughly one half of the libraries offered Loansome Doc services. Of those that did not, most indicated no plans to offer it in the future. The majority had a small number of end users and experienced minimal increases in interlibrary loan activity. Problems were relatively rare. Satisfaction with Loansome Doc was high among all types of libraries. End users were usually physicians or other health care professionals who requested articles for research and patient care. Most learned about Loansome Doc through PubMed or Internet Grateful Med. End users appeared to be largely self-taught or received informal instruction in Loansome Doc. Loansome Doc filled document requests in a timely manner, and end users reported being satisfied with the service. Greater promotion of what Loansome Doc is and how it can benefit libraries can increase the number of participating libraries. While satisfaction of Loansome Doc end users is high, satisfaction could be increased with more help on the PubMed screen, more library training, and faster delivery methods.

Diagnosis of Processes Controlling Dissolved Organic Carbon (DOC) Export in a Subarctic Region by a Dynamic Ecosystem Model

NASA Astrophysics Data System (ADS)

Tang, J.

2015-12-01

Permafrost thawing in high latitudes allows more soil organic carbon (SOC) to become hydrologically accessible. This can increase dissolved organic carbon (DOC) exports and carbon release to the atmosphere as CO2 and CH4, with a positive feedback to regional and global climate warming. However, this portion of carbon loss through DOC export is often neglected in ecosystem models. In this paper, we incorporate a set of DOC-related processes (DOC production, mineralization, diffusion, sorption-desorption and leaching) into an Arctic-enabled version of the dynamic ecosystem model LPJ-GUESS (LPJ-GUESS WHyMe) to mechanistically model the DOC export, and to link this flux to other ecosystem processes. The extended LPJ-GUESS WHyMe with these DOC processes is applied to the Stordalen catchment in northern Sweden. The relative importance of different DOC-related processes for mineral and peatland soils for this region have been explored at both monthly and annual scales based on a detailed variance-based Sobol sensitivity analysis. For mineral soils, the annual DOC export is dominated by DOC fluxes in snowmelt seasons and the peak in spring is related to the runoff passing through top organic rich layers. Two processes, DOC sorption-desorption and production, are found to contribute most to the annual variance in DOC export. For peatland soils, the DOC export during snowmelt seasons is constrained by frozen soils and the processes of DOC production and mineralization, determining the magnitudes of DOC desorption in snowmelt seasons as well as DOC sorption in the rest of months, play the most important role in annual variances of DOC export. Generally, the seasonality of DOC fluxes is closely correlated with runoff seasonality in this region. The current implementation has demonstrated that DOC-related processes in the framework of LPJ-GUESS WHyMe are at an appropriate level of complexity to represent the main mechanism of DOC dynamics in soils. The quantified contributions

Concentration and age of DOC transported from thawing permafrost soils into Arctic headwater streams

NASA Astrophysics Data System (ADS)

Romano, E. L.; Wickland, K.; Ebert, C.; Schuur, E.

2017-12-01

As Arctic permafrost stability decreases due to global climate change, hydrologic dynamics in catchments underlain by permafrost are expected to shift. The thickness of seasonally thawed surface soils is an important driver of the extent to which carbon (C) that was previously stored as frozen soil organic carbon (SOC) will be transported laterally as dissolved organic carbon (DOC). The concentration and radiocarbon (14C) age of newly thawed DOC that moves downslope through tundra soils and is delivered to headwater streams is an important indicator of changing C dynamics. Understanding the timing and quantity of C loss in this form is imperative for greenhouse gas emission and soil C stock estimates, as well as predicting the impact of permafrost thaw on aquatic ecosystems. In this study we examined the relationship between DOC concentrations, 14C-DOC, and active layer thickness (ALT) in thawing soils over time. Water samples were collected once in July 2016 and weekly in 2017 from late May to late August from wells within a long-term tundra soil warming experiment (n=36), located in a discontinuous permafrost zone in Interior Alaska. Preliminary data from 2016 shows average maximum ALT at wells within the warming treatment of 68.9 cm, while wells from control averaged 86.6 cm. 2016 water sample data from wells within the warming treatment showed higher mean DOC concentrations (103.1 ± 32.5 mg/L) and older 14C-DOC values (-28.7 ± 21.1 ‰) than samples from the control (44.5 ± 3.0 mg/L and 11.3 ± 8.6 ‰). To assess inter-annual changes in DOC delivery to local headwater streams, DOC concentration and 14C-DOC were also measured on water samples taken in late summer of 2007, 2008, and 2016 from streams within the watershed surrounding the experimental sites. Weekly sampling in 2017 allowed analysis of seasonal patterns of DOC concentration for that year. Values increased slightly over time at some stream sites (ranging from 4-33 mg/L in 2012 to 2-80 mg/L in

Linking pulses of atmospheric deposition to DOC release in an upland peat-covered catchment

NASA Astrophysics Data System (ADS)

Worrall, F.; Burt, T. P.; Adamson, J. K.

2008-12-01

Changes in atmospheric deposition have been proposed as one possible explanation of the widespread increase in DOC concentration observed in many Northern Hemisphere catchments. This study uses detailed, long-term, monthly monitoring records of pH, conductivity SO4, and DOC in precipitation, soil water, and runoff chemistry from an upland peat-covered catchment in northern England. By deriving impulse transfer functions this study explores whether changes in deposition lead to significant changes in the occurrence of each component in the soil and runoff water; especially significant changes in DOC. The study shows that (1) impulses in the deposition of acidity have no significant effect upon pH or DOC in soil water or runoff. (2) DOC in soil water and runoff is responsive to impulses in SO4 and conductivity, but only when those impulses are changes in soil water chemistry and not when they are in atmospheric deposition. (3) The effects of changes in SO4 and/or conductivity can easily be overemphasized if memory effects are not accounted for, and their effect is limited to only 1 or 2 months after a severe drought. This study can support the view that changes in ionic strength can result in changes in DOC concentration in soil water or runoff, but the system studied is unresponsive to changes in atmospheric deposition. Impulses in soil water SO4 do not lead to increases in DOC concentrations, and so this mechanism does not provide an explanation for DOC increases.

Determination of an organic-acid analog of DOC for use in copper toxicity studies on salmonids

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

MacRae, R.K.; Meyer, J.S.; Hansen, J.A.

1995-12-31

Concentrations of dissolved copper in streams draining mine sites often exceed concentrations shown to cause acute and chronic mortality in salmonids. However, toxicity and impaired behaviors may be modified by dissolved organic carbon (DOC) and other inorganic components present in the site water. The effects of DOC on copper speciation, and thus bioavailability and toxicity, were determined by titrating stream waters with copper, using a cupric ion-specific electrode to detect free copper concentrations. Effects of various competing cations (e.g., Ca{sup +2}, Co{sup +2}) on copper-DOC binding were also evaluated. Titration results were evaluated using Scatchard and non-linear regression analyses tomore » quantify the strength and capacity of copper-DOC binding. Inorganic speciation was determined using the geochemical model MINEQL{sup +}. Results of these titrations indicated the presence of two or three distinct copper binding components in site water DOC. Three commercially available organic acids where then chosen to mimic the binding characteristics of natural DOC. This DOC-analog was used successfully in fish toxicity studies to evaluate the influence of DOC on copper bioavailability. Geochemical models were developed to predict copper speciation in both laboratory test waters and site waters, for any typical combination of water chemistry parameters (pH, alkalinity, [DOC], etc.). A combined interpretation of fish toxicity and modeling results indicate that some DOC-bound copper was bioavailable.« less

Hydrological controls on DOC  :  nitrate resource stoichiometry in a lowland, agricultural catchment, southern UK

NASA Astrophysics Data System (ADS)

Heppell, Catherine M.; Binley, Andrew; Trimmer, Mark; Darch, Tegan; Jones, Ashley; Malone, Ed; Collins, Adrian L.; Johnes, Penny J.; Freer, Jim E.; Lloyd, Charlotte E. M.

2017-09-01

The role that hydrology plays in governing the interactions between dissolved organic carbon (DOC) and nitrogen in rivers draining lowland, agricultural landscapes is currently poorly understood. In light of the potential changes to the production and delivery of DOC and nitrate to rivers arising from climate change and land use management, there is a pressing need to improve our understanding of hydrological controls on DOC and nitrate dynamics in such catchments. We measured DOC and nitrate concentrations in river water of six reaches of the lowland river Hampshire Avon (Wiltshire, southern UK) in order to quantify the relationship between BFI (BFI) and DOC : nitrate molar ratios across contrasting geologies (Chalk, Greensand, and clay). We found a significant positive relationship between nitrate and BFI (p < 0. 0001), and a significant negative relationship between DOC and BFI (p < 0. 0001), resulting in a non-linear negative correlation between DOC : nitrate molar ratio and BFI. In the Hampshire Avon, headwater reaches which are underlain by clay and characterized by a more flashy hydrological regime are associated with DOC : nitrate ratios > 5 throughout the year, whilst groundwater-dominated reaches underlain by Chalk, with a high BFI have DOC : nitrate ratios in surface waters that are an order of magnitude lower (< 0.5). Our analysis also reveals significant seasonal variations in DOC : nitrate transport and highlights critical periods of nitrate export (e.g. winter in sub-catchments underlain by Chalk and Greensand, and autumn in drained, clay sub-catchments) when DOC : nitrate molar ratios are low, suggesting low potential for in-stream uptake of inorganic forms of nitrogen. Consequently, our study emphasizes the tight relationship between DOC and nitrate availability in agricultural catchments, and further reveals that this relationship is controlled to a great extent by the hydrological setting.

Long-term trends in dissolved iron and DOC concentration linked to nitrate depletion in riparian soils

NASA Astrophysics Data System (ADS)

Musolff, Andreas; Selle, Benny; Fleckenstein, Jan H.; Oosterwoud, Marieke R.; Tittel, Jörg

2016-04-01

The instream concentrations of dissolved organic carbon (DOC) are rising in many catchments of the northern hemisphere. Elevated concentrations of DOC, mainly in the form of colored humic components, increase efforts and costs of drinking water purification. In this study, we evaluated a long-term dataset of 110 catchments draining into German drinking water reservoirs in order to assess sources of DOC and drivers of a potential long-term change. The average DOC concentrations across the wide range of different catchments were found to be well explained by the catchment's topographic wetness index. Higher wetness indices were connected to higher average DOC concentrations, which implies that catchments with shallow topography and pronounced riparian wetlands mobilize more DOC. Overall, 37% of the investigated catchments showed a significant long-term increase in DOC concentrations, while 22% exhibited significant negative trends. Moreover, we found that increasing trends in DOC were positively correlated to trends in dissolved iron concentrations at pH≤6 due to remobilization of DOC previously sorbed to iron minerals. Both, increasing trends in DOC and dissolve iron were found to be connected to decreasing trends and low concentrations of nitrate (below ~6 mg/L). This was especially observed in forested catchments where atmospheric N-depositions were the major source for nitrate availability. In these catchments, we also found long-term increases of phosphate concentrations. Therefore, we argue that dissolved iron, DOC and phosphate were jointly released under iron-reducing conditions when nitrate as a competing electron acceptor was too low in concentrations to prevent the microbial iron reduction. In contrast, we could not explain the observed increasing trends in DOC, iron and phosphate concentrations by the long-term trends of pH, sulfate or precipitation. Altogether this study gives strong evidence that both, source and long-term increases in DOC are

Soil-solution partitioning of DOC in acid organic soils: Results from a UK field acidification and alkalization experiment

NASA Astrophysics Data System (ADS)

Oulehle, Filip; Jones, Timothy; Burden, Annette; Evans, Chris

2013-04-01

Dissolved organic carbon (DOC) is an important component of the global carbon (C) cycle and has profound impacts on water chemistry and metabolism in lakes and rivers. Reported increases of DOC concentration in surface waters across Europe and Northern America have been attributed to several drivers; from changing climate and land-use to eutrophication and declining acid deposition. The last of these suggests that acidic deposition suppressed the solubility of DOC, and that this historic suppression is now being reversed by reducing emissions of acidifying pollutants. We studied a set of four parallel acidification and alkalization experiments in organic rich soils which, after three years of manipulation, have shown clear soil solution DOC responses to acidity change. We tested whether these DOC concentration changes were related to changes in the acid/base properties of DOC. Based on laboratory determination of DOC site density (S.D. = amount of carboxylic groups per milligram DOC) and charge density (C.D. = organic acid anion concentration per milligram DOC) we found that the change in DOC soil-solution partitioning was tightly related to the change in degree of dissociation (α = C.D./S.D. ratio) of organic acids (R2=0.74, p<0.01). Carbon turnover in soil organic matter (SOM), determined by soil respiration and β-D-glucosidase enzyme activity measurements, also appears to have some impact on DOC leaching, via constraints on the actual supply of available DOC from SOM; when the turnover rate of C in SOM is low, the effect of α on DOC leaching is reduced. Thus, differences in the magnitude of DOC changes seen across different environments might be explained by interactions between physicochemical restrictions of DOC soil-solution partitioning, and SOM carbon turnover effects on DOC supply.

Z-DOC: a serious game for Z-plasty procedure training.

PubMed

Shewaga, Robert; Knox, Aaron; Ng, Gary; Kapralos, Bill; Dubrowski, Adam

2013-01-01

We present Z-DOC, a (prototype) serious game for training plastic surgery residents the steps comprising the Z-plasty surgical procedure. Z-DOC employs touch-based interactions and promotes competition amongst multiple players/users thus promote engagement and motivation. It is hypothesized that by learning the Z-plasty procedure in an interactive, engaging, and fun gaming environment, trainees will have a much better understanding of the procedure than by traditional learning modalities.

Impact of managed moorland burning on DOC concentrations in soil solutions and stream waters

NASA Astrophysics Data System (ADS)

Palmer, Sheila; Wearing, Catherine; Johnson, Kerrylyn; Holden, Joseph; Brown, Lee

2013-04-01

In the UK uplands, prescribed burning of moorland vegetation is a common practice to maintain suitable habitats for game birds. Many of these landscapes are in catchments covered by significant deposits of blanket peat (typically one metre or more in depth). There is growing interest in the effect of land management on the stability of these peatland carbon stores, and their contribution to dissolved and particulate organic carbon in surface waters (DOC and POC, respectively) and subsequent effects on stream biogeochemistry and ecology. Yet there are surprisingly few published catchment-scale studies on the effect of moorland burning on DOC and POC. As part of the EMBER project, stream chemistry data were collected approximately monthly in ten upland blanket peat catchments in the UK, five of which acted as controls and were not subject to burning. The other five catchments were subject to a history of prescribed burning, typically in small patches (300-900 m2) in rotations of 8-25 years. Soil solution DOC was also monitored at four depths at two intensively studied sites (one regularly burned and one control). At the two intensive sites, soil solution DOC was considerably higher at the burned site, particularly in surface solutions where concentrations in excess of 100 mg/L were recorded on several occasions (median 37 mg/L over 18 months). The high soil solution DOC concentrations at the burned site occurred in the most recently burned plots (less than 2 years prior to start of sampling) and the lowest DOC concentrations were observed in plots burned 15-25 years previously. On average, median stream DOC and POC concentrations were approximately 43% and 35% higher respectively in burned catchments relative to control catchments. All streams exhibited peak DOC in late summer/early autumn with higher peak DOC concentrations in burned catchments (20-66 mg/L) compared to control catchments (18-54 mg/L). During winter months, DOC concentrations were low in control

Process Inference from High Frequency Temporal Variations in Dissolved Organic Carbon (DOC) Dynamics Across Nested Spatial Scales

NASA Astrophysics Data System (ADS)

Tunaley, C.; Tetzlaff, D.; Lessels, J. S.; Soulsby, C.

2014-12-01

In order to understand aquatic ecosystem functioning it is critical to understand the processes that control the spatial and temporal variations in DOC. DOC concentrations are highly dynamic, however, our understanding at short, high frequency timescales is still limited. Optical sensors which act as a proxy for DOC provide the opportunity to investigate near-continuous DOC variations in order to understand the hydrological and biogeochemical processes that control concentrations at short temporal scales. Here we present inferred 15 minute stream water DOC data for a 12 month period at three nested scales (1km2, 3km2 and 31km2) for the Bruntland Burn, a headwater catchment in NE Scotland. High frequency data were measured using FDOM and CDOM probes which work by measuring the fluorescent component and coloured component, respectively, of DOC when exposed to ultraviolet light. Both FDOM and CDOM were strongly correlated (r2 >0.8) with DOC allowing high frequency estimations. Results show the close coupling of DOC with discharge throughout the sampling period at all three spatial scales. However, analysis at the event scale highlights anticlockwise hysteresis relationships between DOC and discharge due to the delay in DOC being flushed from the increasingly large areas of peaty soils as saturation zones expand and increase hydrological connectivity. Lag times vary between events dependent on antecedent conditions. During a 10 year drought period in late summer 2013 it was apparent that very small changes in discharge on a 15 minute timescale result in high increases in DOC. This suggests transport limitation during this period where DOC builds up in the soil and is not flushed regularly, therefore any subsequent increase in discharge results in large DOC peaks. The high frequency sensors also reveal diurnal variability during summer months related to the photo-oxidation, evaporative and biological influences of DOC during the day. This relationship is less

Temperature sensitivity of DOC production and transformation in organic soils of the Yukon River Basin, Alaska

NASA Astrophysics Data System (ADS)

O'Donnell, J.; Butler, K. D.; Aiken, G.

2012-12-01

The flux of dissolved organic carbon (DOC) from terrestrial to aquatic ecosystems represents a critical component of the high-latitude carbon balance. In the Yukon River basin (YRB), DOC fluxes have declined in recent decades, likely in response to regional permafrost thaw and increased groundwater discharge to river flow. Despite improved flux estimates for many arctic rivers, considerable uncertainty exists regarding the potential response of DOC fluxes to projected warming. To improve estimates of future DOC dynamics, it is important to develop a process-based approach whereby empirical constraints are placed on source and sink terms in both soil and river systems. Here, we examine variability in DOC production and microbially mediated transformations as a function of both temperature and organic matter (OM) composition in soils of the YRB. We conducted "tea" experiments by incubating three organic-soil types that vary with depth and decomposition extent (live/dead moss, fibric OM and humic OM) at two temperatures (4 vs. 20 °C). Leachate samples were collected periodically over a 30-day incubation and characterized for DOC concentration, optical properties (specific UV absorbance at 254 nm or SUVA254, fluorescence), and major chemical fractions using XAD8/XAD4 resins. We observed a non-linear increase in DOC production over time, characterized by a rapid initial release of DOC from soils followed by a slower rise in DOC concentration in subsequent weeks. Mean DOC concentration was described by a significant interaction between organic-soil type and temperature, indicating a strong relationship between temperature sensitivity of net DOC production and the decomposition extent of soil OM. On average across all sampling dates, DOC concentrations were highest in leachate from fibric OM (13.4 to 17.8 mgC L-1), and lowest in leachate from humic OM (3.5 to 8.5 mgC L-1). However, the temperature sensitivity of net DOC production was highest in the humic OM treatment

Using fluorescence spectroscopy to gain new insights into seasonal patterns of stream DOC concentrations in an alpine, headwater catchment underlain by discontinuous permafrost in Wolf Creek Research Basin, Yukon Territory, Canada

NASA Astrophysics Data System (ADS)

Shatilla, N. J.; Carey, S.; Tang, W.

2017-12-01

The Canadian subarctic is experiencing rapid climate warming resulting in decreased depth and duration of snowcover, decreased permafrost extent and time span of seasonal frozen ground resulting in increased active layer depth, and increased frequency and magnitude of rainfall events during the growing season. These changes challenge our conceptual models of permafrost hydrology as comparisons between recent and historical streamflow records show an emerging secondary post-freshet peak in flow in recent years along with enhanced winter flows. Long-term monitoring of Granger Creek (7.6km2), an alpine watershed underlain by discontinuous permafrost located within Wolf Creek Research Basin (176km2) in Yukon Territory, Canada provided a multi-decadal record of hydro-meteorological measurements. Granger Creek experienced warmer and wetter summers in 2015-6 compared to 2001-8, and an altered streamflow pattern with an earlier spring freshet and peak in dissolved organic carbon (DOC) concentrations. DOC concentrations post-freshet remained low at both the headwater and meso-catchment scale, which contradicts trends of increasing DOC concentrations observed in larger river systems. Hysteresis loops of sub-hourly measurements of streamflow, salinity and chromophoric dissolved organic matter (CDOM) were analyzed to provide new insights into how hydrological connectivity at the headwater scale affected the timing of solute release with supporting information from optical indices calculated from fluorescence spectroscopy. These indices provided a more nuanced view of catchment dynamics than the DOC concentrations. The composition and quality of DOM varied throughout the growing season with the delivery of older, terrestrially-derived material corresponding to high DOC concentrations at the onset of spring freshet when the catchment was initially being flushed. The origin and quality of stream DOM shifted throughout the rest of the season to newer, more easily mobilized DOM

ToxicDocs (www.ToxicDocs.org): from history buried in stacks of paper to open, searchable archives online.

PubMed

Rosner, David; Markowitz, Gerald; Chowkwanyun, Merlin

2018-02-01

As a result of a legal mechanism called discovery, the authors accumulated millions of internal corporate and trade association documents related to the introduction of new products and chemicals into workplaces and commerce. What did these private entities discuss among themselves and with their experts? The plethora of documents, both a blessing and a curse, opened new sources and interesting questions about corporate and regulatory histories. But they also posed an almost insurmountable challenge to historians. Thus emerged ToxicDocs, possible only with a technological innovation known as "Big Data." That refers to the sheer volume of new digital data and to the computational power to analyze them. Users will be able to identify what firms knew (or did not know) about the dangers of toxic substances in their products-and when. The database opens many areas to inquiry including environmental studies, business history, government regulation, and public policy. ToxicDocs will remain a resource free and open to all, anywhere in the world.

[Estimation of DOC concentrations using CDOM absorption coefficients: a case study in Taihu Lake].

PubMed

Jiang, Guang-Jia; Ma, Rong-Hua; Duan, Hong-Tao

2012-07-01

Dissolved organic carbon (DOC) is the largest organic carbon stock in water ecosystems, which plays an important role in the carbon cycle in water. Chromophoric dissolved organic matter (CDOM), an important water color variation, is the colored fraction of DOC and its absorption controls the instruction of light under water. The available linkage between DOC concentration and CDOM absorptions enables the determination of DOC accumulations using remote sensing reflectance or radiance in lake waters. The present study explored the multi-liner relationship between CDOM absorptions [a(g) (250) and a(g) (365)] and DOC concentrations in Taihu Lake, based on the available data in 4 cruises (201005, 201101, 201103, 201105) (totally 183 sampling sites). Meanwhile, the results were validated with the data of the experiment carried out from August 29 to September 2, 2011 in Taihu Lake (n = 27). Furthermore, a universal pattern of modeling from remote sensing was built for lake waters. The results demonstrated that this method provided more satisfying estimation of DOC concentrations in Taihu Lake. Except the data obtained in January 2011, the fitted results of which were not conductive to the winter dataset (201101) in Taihu Lake, due to the diverse sources and sinks of DOC and CDOM, the multi-liner relationship was robust for the data collected in the other three cruises (R2 = 0.64, RMSE = 14.31%, n = 164), which was validated using the 201108 sampling dataset (R2 = 0.67, RMSE = 10.58%, n = 27). In addition, the form of the statistic model is universal, to some extent, for other water areas, however, there is difference in the modeling coefficients. Further research should be focused on the parameterization using local data from different lakes, which provides effective methodology for the estimation of DOC concentrations in lakes and other water regions.

Implementing Gmail Docs and Blogs for Enhancing Motivation towards Writing in English

ERIC Educational Resources Information Center

Gomez Zapata, Julian Esteban

2010-01-01

This action research paper dealt with how to increase motivation towards writing in English through blogs and Gmail docs in a private school in Medellín, Colombia. It was necessary to explore the concepts of "social interaction," "motivation" and "reasons for writing" to understand how blogs and Gmail docs favored…

Sub-pluvial Saqqara and its possible impact on ancient Egyptian civilization in the Old Kingdom Period (4600 - 4100 yrs BP)

NASA Astrophysics Data System (ADS)

Welc, Fabian; Marks, Leszek

2014-05-01

Geological and geoarchaeological investigations were carried out at several archaeological sites in northern Egypt within the Memphis Necropolis (Saqqara, Abusir, and Giza). Sedimentological analysis of exposures in western Saqqara, excavated by the Polish-Egyptian archaeological team led by Professor Karol Myśliwiec (Institute of Mediterranean and Oriental Cultures, Polish Academy of Sciences), supplied with significant paleoclimatic data and enabled reconstruction of regional climate change during the Old Kingdom Period (4600 - 4100 yrs BP). Potential influence of this climate change on development of the early Egyptian civilization in this area was determined. Examined exposures indicated that during the Old Kingdom Period the area of Saqqara (at present located in a desert) has been many a time flooded with sheet floods, water of which was heavily charged with debris moving down-slope. Performed geochemical and sedimentological analyses proved that climate in the Old Kingdom time was warm and relatively wet. In 4200 - 4100 yrs BP a quick climate change from wet to extremely dry occurred, with occasional stormy winds. These unfavorable climatic conditions were accompanied by catastrophically low seasonal floods of the Nile, resulting in famine and drought recorded in archaeological data and consequently, leading to a disintegration of the Egyptian state. The authors' investigations indicated that a climate change in Egypt in the second half of the 3rd millennium BC is however not as univocal as considered previously. Well-known gradual aridification of the north-eastern Africa, initiated about 5000 yrs BP, has not been unidirectional and was varied regionally. The collected data indicate univocally that there were quasi-cyclic climatic fluctuations. In spite of a distinct trend, the dry period has been interrupted by numerous short wet episodes, occurring during the interval 4600 - 4200 yrs BP and especially at the end of the Old Kingdom Period (ca. 4200 yrs BP

Carbon Isotope Composition as an Indicator of DOC Sources to a Stream During Events in a Temperate Forested Catchment

NASA Astrophysics Data System (ADS)

Doctor, D. H.; Sebestyen, S. D.; Aiken, G. R.; Shanley, J. B.; Kendall, C.; Boyer, E. W.

2006-12-01

Increased DOC flux in streams and rivers is commonly observed during high runoff regimes, however DOC concentrations alone do not provide information about multiple sources or pathways of DOC to streams. In an effort to gain this information, we measured DOC concentrations and stable carbon isotope composition (δ13C-DOC) on samples collected at high-frequency during events at Sleepers River Research Watershed in Vermont, USA. During snowmelt and storm events, peaks in stream DOC concentration (up to 10.5 mg/L) were coincident with peaks in flow. Stream water δ13C-DOC measurements ranged between -23.7‰ and - 28.9‰ and indicated changing sources of DOC during events; the highest δ13C-DOC values occurred consistently at the lowest flows, and the lowest δ13C-DOC values occurred with peaks in discharge. Water samples collected from shallow wells and stacked soil lysimeters showed the highest DOC concentrations in the most shallow (<0.5 m) lysimeter waters, and the lowest concentrations in the deeper (>1.5 m) well waters. Wells and lysimeters exhibited a range of δ13C-DOC values similar to those observed in the stream; however, samples collected from shallow horizons at nested wells and lysimeters consistently showed lower δ13C-DOC values than those from greater depths. Maple leaf litter collected from across the watershed provided an end-member of fresh organic material, with average δ13C composition of -31.3±0.7‰ (n=57), which is lower than the lowest measured DOC values in any of the stream, well, or lysimeter waters. A subset of stream waters were fractionated onto XAD4 and XAD8 resins; the hydrophobic acid fraction (XAD8) had consistently lower δ13C values than the transphilic acid fraction (XAD4), and both of these were lower than those of the bulk DOC. Samples with lower δ13C-DOC values also exhibited higher SUVA-254 values, i.e. greater aromaticity. Thus, lower δ13C-DOC values are interpreted as an indicator of relatively "fresh", more aromatic

A Novel Source of DOC and DON to Watershed Soils

NASA Astrophysics Data System (ADS)

Aitkenhead-Peterson, J. A.

2017-12-01

A source of dissolved organic carbon (DOC) and nitrogen (DON) to soils and groundwater is that emanating from decomposing mammals. Although there is an increase in human donor facilities (body farms) in the USA and in mass mortality events (MME) worldwide, this injection of DOC and DON into watershed soils has received little attention. Studies at two human donor facilities in Texas, USA have revealed that the purge fluid associated with decomposition is extremely high in DOC and DON and migrates down the soil profile. Two studies were carried out 1) The southeast Texas Applied Forensic Science (STAFS) facility on an Alfisol with a saturated hydraulic conductivity of 331 mm hr-1 and 83% sand and 2) the Forensic Anthropology Research Facility (FARF) on Mollisols with a saturated hydraulic conductivity of 3.6-9.7 mm hr-1 and 28-33% sand. The numbers of days since donors were laid in the environment ranged from 219-680 d at STAFS and 306-960 d at FACTS. Purge can occur between 5 and 30 d dependent on the time of year the body is placed and the resultant phenomenon is termed cadaver decomposition island (CDI). Soil cores were taken at 5 cm increments to a depth of 30 cm in the sandy soil and 15 cm in the clayey/rocky soil. In the sandy soils, DOC concentrations were significantly higher in all the CDI soils when compared to control soils at depths of 15, 20, 25 and 30 cm and ranged from 121.7 µg g-1 (30 cm) to 167.6 µg g-1 (15 cm) in control soils and 461.9 µg g-1 (30 cm) to 660.4 µg g-1 (15 cm) in CDI soils, representing a three- to four-fold increase in DOC relative to control soils. DON in all CDI soils was not significantly higher than control soils until 30 cm depth and ranged from 9.9-32.3 µg g-1 in CDI soils and 121.7 µg g-1 in control soil, representing a two- to seven-fold increase in DON relative to control soils. DOC concentrations in control soils at the FARF site at 15 cm ranged 215-365 µg g-1 while in the CDI soils DOC was higher (range: 270

75 FR 12496 - Proposed Information Collection; Comment Request; DOC National Environmental Policy Act...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-16

... DEPARTMENT OF COMMERCE Office of the Secretary Proposed Information Collection; Comment Request; DOC National Environmental Policy Act Environmental Questionnaire and Checklist AGENCY: Office of the...) Environmental Questionnaire and Checklist (EQC) was developed to assist DOC in complying with NEPA by...

Temporal Variability of Stemflow Dissolved Organic Carbon (DOC) Concentrations and Quality from Morphologically Contrasting Deciduous Canopies

NASA Astrophysics Data System (ADS)

van Stan, J. T.; Levia, D. F.; Inamdar, S. P.; Mitchell, M. J.; Mage, S. M.

2010-12-01

Dissolved organic carbon (DOC) inputs from canopy-derived hydrologic fluxes play a significant role in the terrestrial carbon budgets of forested ecosystems. However, no studies known to the authors have examined the variability of both DOC concentrations and quality for stemflow across time scales, nor has any study to date evaluated the effects of canopy structure on stemflow DOC characteristics. This investigation seeks to rectify this knowledge gap by examining the variability of stemflow DOC concentrations and quality across contrasting canopy morphologies and time scales (seasonal, storm and intrastorm). Bulk and intrastorm stemflow samples from a less dense, rough-barked, more plagiophile (Liriodendron tulipifera L. (tulip poplar)) and a denser, thin-barked, more erectophile (Fagus grandifolia Ehrh. (American beech)) canopy were collected and analyzed for DOC quality using metrics derived from UV-vis spectroscopy (E2:E3 ratio, SUVA254, select spectral slope (S), and spectral slope ratios (SR)). Our results suggest that stemflow DOC concentrations and quality change as crown architectural traits enhance or diminish hydrologic retention time within the canopy. The architecture of L. tulipifera canopies likely retards the flow of intercepted water, increasing chemical exchange with bark and foliar surfaces. UV-vis metrics indicated that this increased chemical exchange, particularly with bark surfaces, generally enhanced aromatic hydrocarbon content and increased molecular weight. Because leaf presence influenced DOC quality, stemflow DOC characteristics also varied seasonally in response to canopy condition. At the inter- and intrastorm scale, stemflow DOC concentration and quality varied with meteorological and antecedent canopy conditions. Since recent studies have linked stemflow production to preferential subsurface transport of dissolved chemistries, trends in DOC speciation and fluxes described in this study may impact soil environments within wooded

Function analysis of 5'-UTR of the cellulosomal xyl-doc cluster in Clostridium papyrosolvens.

PubMed

Zou, Xia; Ren, Zhenxing; Wang, Na; Cheng, Yin; Jiang, Yuanyuan; Wang, Yan; Xu, Chenggang

2018-01-01

Anaerobic, mesophilic, and cellulolytic Clostridium papyrosolvens produces an efficient cellulolytic extracellular complex named cellulosome that hydrolyzes plant cell wall polysaccharides into simple sugars. Its genome harbors two long cellulosomal clusters: cip - cel operon encoding major cellulosome components (including scaffolding) and xyl - doc gene cluster encoding hemicellulases. Compared with works on cip - cel operon, there are much fewer studies on xyl - doc mainly due to its rare location in cellulolytic clostridia. Sequence analysis of xyl - doc revealed that it harbors a 5' untranslated region (5'-UTR) which potentially plays a role in the regulation of downstream gene expression. Here, we analyzed the function of 5'-UTR of xyl - doc cluster in C. papyrosolvens in vivo via transformation technology developed in this study. In this study, we firstly developed an electrotransformation method for C. papyrosolvens DSM 2782 before the analysis of 5'-UTR of xyl - doc cluster. In the optimized condition, a field with an intensity of 7.5-9.0 kV/cm was applied to a cuvette (0.2 cm gap) containing a mixture of plasmid and late cell suspended in exponential phase to form a 5 ms pulse in a sucrose-containing buffer. Afterwards, the putative promoter and the 5'-UTR of xyl - doc cluster were determined by sequence alignment. It is indicated that xyl - doc possesses a long conservative 5'-UTR with a complex secondary structure encompassing at least two perfect stem-loops which are potential candidates for controlling the transcriptional termination. In the last step, we employed an oxygen-independent flavin-based fluorescent protein (FbFP) as a quantitative reporter to analyze promoter activity and 5'-UTR function in vivo. It revealed that 5'-UTR significantly blocked transcription of downstream genes, but corn stover can relieve its suppression. In the present study, our results demonstrated that 5'-UTR of the cellulosomal xyl - doc cluster blocks the

Chronological reconstruction of eolianites and transversal mobile dunes of northwest coast of Ceará State - Brazil, in the last 3000 cal yrs BP

NASA Astrophysics Data System (ADS)

Castro, João Wagner Alencar; Malta, Julia Varella; Miguel, Lucas Lavo Antonio Jimo; Cabral, Caique Lima; Passemilio, Alvaro Balmant

2017-10-01

Dunefields are very common in the northern coastal zone of northeast Brazil. They have the potential to yield important information about paleoclimate, paleo-winds and regional winds and their response to sea-level fluctuations during the Holocene. We reconstructed the coastal dunes geochronological evolution of northwest Ceará State - Brazil, in the last 3000 cal yrs BP, using detailed analyses of lithostratigraphy, microfossil (foraminifera), wind regime, dune monitoring and 8 radiocarbon dates. The chronology was based on 14C dating in eolianites and monitoring transversal mobile dunes movement processes. Radiocarbon date results indicated that the dunes corresponding to eolianites revealed ages between 2760-2480 and 980-750 cal yrs BP, suggesting that the vast transversal mobile dunefields were formed after this period in similar condition to the current sea-level. We considered that the material transportation by the prevailing east winds towards the transversal dunes is estimated in the order of 11.0 m/year, thus the current aeolian system is less than 1000 yrs BP.

Algorithm Development and Validation for Satellite-Derived Distributions of DOC and CDOM in the US Middle Atlantic Bight

NASA Technical Reports Server (NTRS)

Mannino, Antonio; Russ, Mary E.; Hooker, Stanford B.

2007-01-01

In coastal ocean waters, distributions of dissolved organic carbon (DOC) and chromophoric dissolved organic matter (CDOM) vary seasonally and interannually due to multiple source inputs and removal processes. We conducted several oceanographic cruises within the continental margin of the U.S. Middle Atlantic Bight (MAB) to collect field measurements in order to develop algorithms to retrieve CDOM and DOC from NASA's MODIS-Aqua and SeaWiFS satellite sensors. In order to develop empirical algorithms for CDOM and DOC, we correlated the CDOM absorption coefficient (a(sub cdom)) with in situ radiometry (remote sensing reflectance, Rrs, band ratios) and then correlated DOC to Rrs band ratios through the CDOM to DOC relationships. Our validation analyses demonstrate successful retrieval of DOC and CDOM from coastal ocean waters using the MODIS-Aqua and SeaWiFS satellite sensors with mean absolute percent differences from field measurements of < 9 %for DOC, 20% for a(sub cdom)(355)1,6 % for a(sub cdom)(443), and 12% for the CDOM spectral slope. To our knowledge, the algorithms presented here represent the first validated algorithms for satellite retrieval of a(sub cdom) DOC, and CDOM spectral slope in the coastal ocean. The satellite-derived DOC and a(sub cdom) products demonstrate the seasonal net ecosystem production of DOC and photooxidation of CDOM from spring to fall. With accurate satellite retrievals of CDOM and DOC, we will be able to apply satellite observations to investigate interannual and decadal-scale variability in surface CDOM and DOC within continental margins and monitor impacts of climate change and anthropogenic activities on coastal ecosystems.

Plant diversity induces a shift of DOC concentration over time - results from long term and large scale experiment

NASA Astrophysics Data System (ADS)

Lange, Markus; Gleixner, Gerd

2016-04-01

Plant diversity has been demonstrated as a crucial factor for soil organic carbon (SOC) storage. The horizontal SOC formation in turn is strongly impacted by the relative small but consistent flow of dissolved organic carbon (DOC) in soils. In this process, pore water leaches plant material and already stored SOC while simultaneously these leachates are transported downwards. However, there is a big uncertainty about the drivers of DOC flux; in particular about the importance of biological processes. We investigated the impact of plant diversity and other biotic drivers on DOC concentrations and total DOC fluxes (concentration × sampled water amount). In addition, we considered abiotic factors such as weather and soil conditions to assess the relative importance of biotic and abiotic drivers and how their importance changes over time. We used a comprehensive data set, gathered in the frame of the long-term biodiversity experiment "The Jena Experiment". Permanent monitoring started directly after establishment of the field site in 2002 and is still running. This enabled us to trace the impact of plant communities with their increasing establishment over the time on DOC concentration. We found the amount of sampled pore water best explained by rainfall, while it was not related to plant associated variables. Directly after establishing the experimental site, DOC concentrations were highest and then decreasing with time. In the first period of the experiment plant diversity had no or even a slightly negative impact on DOC concentrations. The direction of the plant diversity effect on DOC concentrations changed over time; namely in later phases we observed highest DOC concentrations on plots with high plant diversity. Moreover, DOC concentrations were negatively affected by increased amounts of sampled pore water indicating a dilution effect. Even though this impact was highly significant; its effect size was even less pronounced at later time points. In summary

Variable flushing mechanisms and landscape structure control stream DOC export during snowmelt in a set of nested catchments

Treesearch

Vincent J. Pacific; Kelsey G. Jencso; Brian L. McGlynn

2010-01-01

Stream DOC dynamics during snowmelt have been the focus of much research, and numerous DOC mobilization and delivery mechanisms from riparian and upland areas have been proposed. However, landscape structure controls on DOC export from riparian and upland landscape elements remains poorly understood. We investigated stream and groundwater DOC dynamics across three...

Dissolved Organic Carbon in Marginal, Damaged Peatlands: Using 14C to Understand DOC Losses

NASA Astrophysics Data System (ADS)

Luscombe, D.; Grand-Clement, E.; Garnett, M.; Anderson, K.; Gatis, N.; Benaud, P.; Brazier, R.

2013-12-01

Peatlands are widely represented throughout the world and act as an important store of carbon, as well as providing society with a range of other ecosystem services, such as drinking water or the support of rare habitats. However, the combination of historical management practices, and the predicted impact of climate change means that they are now largely under threat. In the shallow peatlands of Exmoor National Park (South West UK), peat cutting and intensive drainage in the 19th and 20th century for agricultural reclamation have changed the hydrological behaviour of the peat. This damage has dried out the upper layers, causing oxidation, erosion and vegetation change. In addition, their location on the southernmost limit of peatlands geographical extent in northern Europe makes them particularly vulnerable to the predicted changes in rainfall and temperature. Recent modelling work has shown that such marginal peatlands may disappear as early as 2050. Restoration programs are currently in place, aiming to restore the hydrological functioning of the peat. However, current dissolved organic carbon (DOC) losses from damaged peatlands are especially of concern, because of the contribution of the aquatic pathways in the C flux, and because of the impact on water quality. DOC has been shown to originate from the drainage of highly-aged organic matter. In stream waters, DOC from low flow tends to contain a larger component of older C compared to that of high flow. Both the impact of extensive drainage on where DOC is originating from and the effect of peatland restoration on this process remain poorly understood. We used 14C dating of DOC from streams and pore water, as well as from damaged peat, in order to gain a better understanding of the process and origin of DOC loss in drained shallow peatlands. This will further help us understand the potential for peatland restoration. Work was carried out in a small intensively monitored catchment in Exmoor. Samples were taken

Vegetation and climate controls on potential CO2, DOC and DON production in northern latitude soils

USGS Publications Warehouse

Neff, J.C.; Hooper, D.U.

2002-01-01

Climatic change may influence decomposition dynamics in arctic and boreal ecosystems, affecting both atmospheric CO2 levels, and the flux of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) to aquatic systems. In this study, we investigated landscape-scale controls on potential production of these compounds using a one-year laboratory incubation at two temperatures (10?? and 30??C). We measured the release of CO2, DOC and DON from tundra soils collected from a variety of vegetation types and climatic regimes: tussock tundra at four sites along a latitudinal gradient from the interior to the north slope of Alaska, and soils from additional vegetation types at two of those sites (upland spruce at Fairbanks, and wet sedge and shrub tundra at Toolik Lake in northern Alaska). Vegetation type strongly influenced carbon fluxes. The highest CO2 and DOC release at the high incubation temperature occurred in the soils of shrub tundra communities. Tussock tundra soils exhibited the next highest DOC fluxes followed by spruce and wet sedge tundra soils, respectively. Of the fluxes, CO2 showed the greatest sensitivity to incubation temperatures and vegetation type, followed by DOC. DON fluxes were less variable. Total CO2 and total DOC release were positively correlated, with DOC fluxes approximately 10% of total CO2 fluxes. The ratio of CO2 production to DOC release varied significantly across vegetation types with Tussock soils producing an average of four times as much CO2 per unit DOC released compared to Spruce soils from the Fairbanks site. Sites in this study released 80-370 mg CO2-C g soil C-1 and 5-46 mg DOC g soil C-1 at high temperatures. The magnitude of these fluxes indicates that arctic carbon pools contain a large proportion of labile carbon that could be easily decomposed given optimal conditions. The size of this labile pool ranged between 9 and 41% of soil carbon on a g soil C basis, with most variation related to vegetation type rather than

Strontium ranelate: short- and long-term benefits for post-menopausal women with osteoporosis

PubMed Central

2008-01-01

Strontium ranelate is a bone-seeking element that has been assessed in post-menopausal osteoporosis in two large double-blind, placebo-controlled studies. This treatment is able to decrease the risk of vertebral fractures, by 41% over 3 yrs, and by 49% within the first year of treatment. This risk of non-vertebral fractures is decreased by 16% and, in patients at high risk for such a fracture, the risk of hip fracture is decreased by 36% over 3 yrs. Recent 5-yr data from these double-blind, placebo-controlled studies show that the anti-fracture efficacy is maintained over time. Treatment efficacy with strontium ranelate has been documented across a wide range of patient profiles: age, number of prevalent vertebral fractures, BMI, as well as family history of osteoporosis and addiction to smoking are not determinants of anti-fracture efficacy. During these clinical trials, safety was good. Its large spectrum of efficacy allows the use of strontium ranelate in the different subgroups of patients with post-menopausal osteoporosis. PMID:18556647

48 CFR 1323.404-70 - DOC affirmative procurement program.

Code of Federal Regulations, 2011 CFR

2011-10-01

... COMMERCE SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Use of Recovered Materials 1323.404-70 DOC affirmative procurement...

Leaching of DOC, DN, and inorganic constituents from scrap tires.

PubMed

Selbes, Meric; Yilmaz, Ozge; Khan, Abdul A; Karanfil, Tanju

2015-11-01

One concern for recycle and reuse of scrap tires is the leaching of tire constituents (organic and inorganic) with time, and their subsequent potential harmful impacts in environment. The main objective of this study was to examine the leaching of dissolved organic carbon (DOC), dissolved nitrogen (DN), and selected inorganic constituents from scrap tires. Different sizes of tire chips and crumb rubber were exposed to leaching solutions with pH's ranging from 3.0 to 10.0 for 28days. The leaching of DOC and DN were found to be higher for smaller size tire chips; however, the leaching of inorganic constituents was independent of the size. In general, basic pH conditions increased the leaching of DOC and DN, whereas acidic pH conditions led to elevated concentrations of metals. Leaching was minimal around the neutral pH values for all the monitored parameters. Analysis of the leaching rates showed that components associated with the rubbery portion of the tires (DOC, DN, zinc, calcium, magnesium, etc.) exhibited an initial rapid followed by a slow release. On the other hand, a constant rate of leaching was observed for iron and manganese, which are attributed to the metal wires present inside the tires. Although the total amounts that leached varied, the observed leaching rates were similar for all tire chip sizes and leaching solutions. Operation under neutral pH conditions, use of larger size tire chips, prewashing of tires, and removal of metal wires prior to application will reduce the impact of tire recycle and reuse. Copyright © 2015 Elsevier Ltd. All rights reserved.

Concentration, UV-spectroscopic characteristics and fractionation of DOC in stormflow from an urban stream, Southern California, USA

USGS Publications Warehouse

Izbicki, J.A.; Pimentel, I.M.; Johnson, Russell; Aiken, G.R.; Leenheer, J.

2007-01-01

The composition of dissolved organic carbon (DOC) in stormflow from urban areas has been greatly altered, both directly and indirectly, by human activities and there is concern that there may be public health issues associated with DOC, which has unknown composition from different sources within urban watersheds. This study evaluated changes in the concentration and composition of DOC in stormflow in the Santa Ana River and its tributaries between 1995 and 2004 using a simplified approach based on the differences in the optical properties of DOC and using operationally defined differences in molecular weight and solubility. The data show changes in the composition of DOC in stormflow during the rainy season and differences associated with runoff from different parts of the basin, including extensive upland areas burned prior to the 2004 rainy season.Samples were collected from the Santa Ana River, which drains ~6950 km2 of the densely populated coastal area of southern California, during 23 stormflows between 1995 and 2004. Dissolved organic carbon (DOC) concentrations during the first stormflows of the ‘winter’ (November to March) rainy season increased rapidly with streamflow and were positively correlated with increased faecal indicator bacteria concentrations. DOC concentrations were not correlated with streamflow or with other constituents during stormflows later in the rainy season and DOC had increasing UV absorbance per unit carbon as the rainy season progressed. DOC concentrations in stormflow from an urban drain tributary to the river also increased during stormflow and were greater than concentrations in the river. DOC concentrations in stormflow from a tributary stream, draining urban and agricultural land that contained more than 320 000 animals, mostly dairy cows, were higher than concentrations in stormflow from the river and from the urban drain. Fires that burned large areas of the basin before the 2004 rainy season did not increase DOC

Linking soil DOC production rates and transport processes from landscapes to sub-basin scales

NASA Astrophysics Data System (ADS)

Tian, Y. Q.; Yu, Q.; Li, J.; Ye, C.

2014-12-01

Recent research rejects the traditional perspective that dissolved organic carbon (DOC) component in global carbon cycle are simply trivial, and in fact evidence demonstrates that lakes likely mediate carbon dynamics on a global scale. Riverine and estuarine carbon fluxes play a critical role in transporting and recycling carbon and nutrients, not only within watersheds but in their receiving waters. However, the underlying mechanisms that drive carbon fluxes, from land to rivers, lake and oceans, remain poorly understood. This presentation will report a research result of the scale-dependent DOC production rate in coastal watersheds and DOC transport processes in estuarine regions. We conducted a series of controlled experiments and field measurements for examining biogeochemical, biological, and geospatial variables that regulate downstream processing on global-relevant carbon fluxes. Results showed that increased temperatures and raised soil moistures accelerate decomposition rates of organic matter with significant variations between vegetation types. The measurements at meso-scale ecosystem demonstrated a good correlation to bulk concentration of DOC monitored in receiving waters at the outlets of sub-basins (R2 > 0.65). These field and experimental measurements improved the model of daily carbon exports through below-ground processes as a function of the organic matter content of surface soils, forest litter supply, and temperature. The study demonstrated a potential improvement in modeling the co-variance of CDOM and DOC with the unique terrestrial sources. This improvement indicated a significant promise for monitoring riverine and estuarine carbon flux from satellite images. The technical innovations include deployments of 1) mini-ecosystem (mesocosms) with soil as replicate controlled experiments for DOC production and leaching rates, and 2) aquatic mesocosms for co-variances of DOC and CDOM endmembers, and an instrumented incubation experiment for

The centrality of meta-programming in the ES-DOC eco-system

NASA Astrophysics Data System (ADS)

Greenslade, Mark

2017-04-01

The Earth System Documentation (ES-DOC) project is an international effort aiming to deliver a robust earth system model inter-comparison project documentation infrastructure. Such infrastructure both simplifies & standardizes the process of documenting (in detail) projects, experiments, models, forcings & simulations. In support of CMIP6, ES-DOC has upgraded its eco-system of tools, web-services & web-sites. The upgrade consolidates the existing infrastructure (built for CMIP5) and extends it with the introduction of new capabilities. The strategic focus of the upgrade is improvements in the documentation experience and broadening the range of scientific use-cases that the archived documentation may help deliver. Whether it is highlighting dataset errors, exploring experimental protocols, comparing forcings across ensemble runs, understanding MIP objectives, reviewing citations, exploring component properties of configured models, visualising inter-model relationships, scientists involved in CMIP6 will find the ES-DOC infrastructure helpful. This presentation underlines the centrality of meta-programming within the ES-DOC eco-system. We will demonstrate how agility is greatly enhanced by taking a meta-programming approach to representing data models and controlled vocabularies. Such an approach nicely decouples representations from encodings. Meta-models will be presented along with the associated tooling chain that forward engineers artefacts as diverse as: class hierarchies, IPython notebooks, mindmaps, configuration files, OWL & SKOS documents, spreadsheets …etc.

A systematic examination of the relationships between CDOM and DOC in inland waters in China

NASA Astrophysics Data System (ADS)

Song, Kaishan; Zhao, Ying; Wen, Zhidan; Fang, Chong; Shang, Yingxin

2017-10-01

Chromophoric dissolved organic matter (CDOM) plays a vital role in the biogeochemical cycle in aquatic ecosystems. The relationship between CDOM and dissolved organic carbon (DOC) has been investigated, and this significant relationship lays the foundation for the estimation of DOC using remotely sensed imagery data. The current study examined samples from freshwater lakes, saline lakes, rivers and streams, urban water bodies, and ice-covered lakes in China for tracking the variation of the relationships between DOC and CDOM. The regression model slopes for DOC vs. aCDOM (275) ranged from extremely low 0.33 (highly saline lakes) to 1.03 (urban waters) and 3.01 (river waters). The low values were observed in saline lake waters and waters from semi-arid or arid regions, where strong photobleaching is expected due to less cloud cover, longer water residence time, and daylight hours. In contrast, high values were found in waters developed in wetlands or forest in Northeast China, where more organic matter was transported from catchment to waters. The study also demonstrated that closer relationships between CDOM and DOC were revealed when aCDOM (275) were sorted by the ratio of aCDOM(250)/aCDOM (365), which is a measure for the CDOM absorption with respect to its composition, and the determination of coefficient of the regression models ranged from 0.79 to 0.98 for different groups of waters. Our results indicate the relationships between CDOM and DOC are variable for different inland waters; thus, models for DOC estimation through linking with CDOM absorption need to be tailored according to water types.

Correlation between breakfast tryptophan content and morning-evening in Japanese infants and students aged 0-15 yrs.

PubMed

Harada, Tetsuo; Hirotani, Masaaki; Maeda, Mari; Nomura, Hiromi; Takeuchi, Hitomi

2007-03-01

Tryptophan can be metabolized via 5-hydroxytryptamine=serotonin to melatonin by a series of 4 enzymes in pineal body. Lack of serotonin in body fluid in the brain during daytime can lead to several psychiatric disorders, while shortage of plasma-melatonin at night can be related to sleep disorders. The Morning-Evening (M-E) questionnaire and the original questionnaire including questions on sleep habits, mental symptoms, and contents of meals were administered to 1055 infants aged 0-6 yrs, 751 students attending an elementary school, and 473 students attending junior high school in Kochi City (33 degrees N). The index of tryptophan taken at breakfast (Trp-Index) was calculated as tryptophan amount per one meal based on the tryptophan included in each 100 g of the foods and a standard amount of food per one meal. A significant positive-correlation between M-E scores and Trp-Index was not shown by relatively older students, aged 9-15 yrs (Pearson's test, r=0.044-0.123, p=0.071-0.505), whereas a significant positive correlation was shown by infants and young elementary school students aged 0-8 yrs (r=0.180, 0.258, p<0.001). The more frequently the infants had difficulty falling asleep at bedtime and waking up in the morning, the less the Trp-Indices taken at breakfast were (Kruskall-Wallis-test, p=0.027 for difficulty falling asleep; p=0.008 for difficulty waking up). The more frequently infants became angry even by a little trigger, or depressed, the lower (more evening-typed) the M-E scores were (Kruskal-Wallis test: p

CDOM fluorescence as a proxy of DOC concentration in natural waters: a comparison of four contrasting tropical systems.

PubMed

Rochelle-Newall, E; Hulot, F D; Janeau, J L; Merroune, A

2014-01-01

Chromophoric dissolved organic matter (CDOM) fluorescence or absorption is often proposed as a rapid alternative to chemical methods for the estimation of bulk dissolved organic carbon (DOC) concentration in natural waters. However, the robustness of this method across a wide range of systems remains to be shown. We measured CDOM fluorescence and DOC concentration in four tropical freshwater and coastal environments (estuary and coastal, tropical shallow lakes, water from the freshwater lens of two small islands, and soil leachates). We found that although this method can provide an estimation of DOC concentration in sites with low variability in DOC and CDOM sources in systems where the variability of DOC and CDOM sources are high, this method should not be used as it will lead to errors in the estimation of the bulk DOC concentration.

The Effects of Collaborative Writing Activity Using Google Docs on Students' Writing Abilities

ERIC Educational Resources Information Center

Suwantarathip, Ornprapat; Wichadee, Saovapa

2014-01-01

Google Docs, a free web-based version of Microsoft Word, offers collaborative features which can be used to facilitate collaborative writing in a foreign language classroom. The current study compared writing abilities of students who collaborated on writing assignments using Google Docs with those working in groups in a face-to-face classroom.…

panMetaDocs and DataSync - providing a convenient way to share and publish research data

NASA Astrophysics Data System (ADS)

Ulbricht, D.; Klump, J. F.

2013-12-01

In recent years research institutions, geological surveys and funding organizations started to build infrastructures to facilitate the re-use of research data from previous work. At present, several intermeshed activities are coordinated to make data systems of the earth sciences interoperable and recorded data discoverable. Driven by governmental authorities, ISO19115/19139 emerged as metadata standards for discovery of data and services. Established metadata transport protocols like OAI-PMH and OGC-CSW are used to disseminate metadata to data portals. With the persistent identifiers like DOI and IGSN research data and corresponding physical samples can be given unambiguous names and thus become citable. In summary, these activities focus primarily on 'ready to give away'-data, already stored in an institutional repository and described with appropriate metadata. Many datasets are not 'born' in this state but are produced in small and federated research projects. To make access and reuse of these 'small data' easier, these data should be centrally stored and version controlled from the very beginning of activities. We developed DataSync [1] as supplemental application to the panMetaDocs [2] data exchange platform as a data management tool for small science projects. DataSync is a JAVA-application that runs on a local computer and synchronizes directory trees into an eSciDoc-repository [3] by creating eSciDoc-objects via eSciDocs' REST API. DataSync can be installed on multiple computers and is in this way able to synchronize files of a research team over the internet. XML Metadata can be added as separate files that are managed together with data files as versioned eSciDoc-objects. A project-customized instance of panMetaDocs is provided to show a web-based overview of the previously uploaded file collection and to allow further annotation with metadata inside the eSciDoc-repository. PanMetaDocs is a PHP based web application to assist the creation of metadata in

Winter Ground Temperatures Control Snowmelt DOC Export From a Discontinuous Permafrost Watershed: A Multi-Year Perspective

NASA Astrophysics Data System (ADS)

Carey, S. K.

2006-12-01

For discontinuous and continuous permafrost watersheds, the largest mass flux of dissolved organic carbon (DOC) occurs during the snowmelt period. During this time, available allochtonous organic carbon that has accumulated over the winter in frozen organic soils is rapidly flushed to the basin outlet. While this process has been observed now in many river systems of different size and location, there have been few inter-annual reports on the mass of DOC loss and the factors controlling its variability during freshet. Hydrological and DOC fluxes were recorded for the 2002, 2003 and 2006 snowmelt season with supplementary over-winter data for an 8 square kilometer sub-basin (Granger Basin) of the Wolf Creek Research Basin, Yukon Territory, Canada. Granger Basin is an alpine catchment above treeline underlain with discontinuous permafrost (approximately 70 %) and has widespread surface organic soils up to 0.4 m in thickness. Pre-melt snow water equivalent varied widely throughout the basin, yet was greatest in 2006, followed by 2002 and 2003. Ground temperatures were notably colder throughout the 2003 winter compared with 2006 and 2002. For all years, discharge began in mid-May, and was a continuous event in 2002 and 2006. In 2003 four distinct melt-periods were observed due to rising and falling temperatures. During freshet, stream DOC concentration increased rapidly from < 2 mg C/L to > 15 mg C/L on the first ascending limb of the hydrograph in each year. In 2003, DOC was largely flushed from the catchment several weeks prior to peak freshet. DOC concentration in wells and piezometers followed a similar pattern to streamflow DOC, with 2003 groundwater DOC concentrations less than 2002 and 2006. The total mass flux of DOC during freshet was 0.85, 0.45 and 1.01 g C/m2 for 2002, 2003 and 2006 respectively. Despite differences in pre-melt snow accumulation, the timing of melt and the volume of discharge, it appears that spring DOC export is largely controlled by over

DOC Dynamics in Small Headwater Streams: the Role of Hydrology, Climate, and Land Management

NASA Astrophysics Data System (ADS)

Lajtha, K.; Lee, B. S.; Jones, J. A.

2015-12-01

Dissolved organic carbon (DOC) is a critical component of the carbon (C) cycle of both terrestrial and aquatic systems. For small headwater allochthonous streams, terrestrial C delivery fuels the metabolism of receiving waters and significantly influences biotic diversity and function. While nutrient fluxes in streams have long been used as indicators of terrestrial ecosystem processes, less attention has been given to terrestrial controls on DOC export. We used the long-term stream chemistry records from the H.J. Andrews Forest LTER to examine forest management, climatic, and hydrologic controls on both seasonal and annual DOC fluxes. Within a watershed, annual DOC flux was highly related to annual discharge (Q), although considerable variability in higher discharge years suggested a role for indices of storminess, especially early in the water year. Among watersheds, younger, previously harvested watersheds generally had significantly lower DOC fluxes for a given Q than old-growth watersheds, even 4+ decades after harvest. The exception to this pattern was a harvested watershed that had significant downed wood retained on site, and had densities of coarse woody debris (CWD) close to that of the old-growth watersheds even though live tree biomass was similar to the other harvested watersheds. Other climatic factors did not appear to have significant roles in predicting either seasonal or annual fluxes of DOC. This is in sharp contrast to fluxes of nitrate at our site, which appears to be related most significantly to the presence of alder within the watershed. Taken together, our data suggest a persistent and cascading role for CWD in old-growth forest ecosystems.

G-DOC: A Systems Medicine Platform for Personalized Oncology1

PubMed Central

Madhavan, Subha; Gusev, Yuriy; Harris, Michael; Tanenbaum, David M; Gauba, Robinder; Bhuvaneshwar, Krithika; Shinohara, Andrew; Rosso, Kevin; Carabet, Lavinia A; Song, Lei; Riggins, Rebecca B; Dakshanamurthy, Sivanesan; Wang, Yue; Byers, Stephen W; Clarke, Robert; Weiner, Louis M

2011-01-01

Currently, cancer therapy remains limited by a “one-size-fits-all” approach, whereby treatment decisions are based mainly on the clinical stage of disease, yet fail to reference the individual's underlying biology and its role driving malignancy. Identifying better personalized therapies for cancer treatment is hindered by the lack of high-quality “omics” data of sufficient size to produce meaningful results and the ability to integrate biomedical data from disparate technologies. Resolving these issues will help translation of therapies from research to clinic by helping clinicians develop patient-specific treatments based on the unique signatures of patient's tumor. Here we describe the Georgetown Database of Cancer (G-DOC), a Web platform that enables basic and clinical research by integrating patient characteristics and clinical outcome data with a variety of high-throughput research data in a unified environment. While several rich data repositories for high-dimensional research data exist in the public domain, most focus on a single-data type and do not support integration across multiple technologies. Currently, G-DOC contains data from more than 2500 breast cancer patients and 800 gastrointestinal cancer patients, G-DOC includes a broad collection of bioinformatics and systems biology tools for analysis and visualization of four major “omics” types: DNA, mRNA, microRNA, and metabolites. We believe that G-DOC will help facilitate systems medicine by providing identification of trends and patterns in integrated data sets and hence facilitate the use of better targeted therapies for cancer. A set of representative usage scenarios is provided to highlight the technical capabilities of this resource. PMID:21969811

The topographic wetness index as a predictor for hot spots of DOC export from catchments

NASA Astrophysics Data System (ADS)

Musolff, Andreas; Oosterwoud, Marieke; Tittel, Jörg; Selle, Benny; Fleckenstein, Jan H.

2015-04-01

Dissolved organic carbon (DOC) concentrations in the discharge of many catchments in Europe and North America are rising. This increase is of concern for the drinking water supply from reservoirs since high DOC concentrations cause additional costs in water treatment and potentially the formation of harmful disinfection by-products. A prerequisite for understanding this increase is the knowledge on the spatial distribution of dominant soil DOC sources within catchments and on mobilization as well as transfer processes to the surface water. A number of studies identified wetland soils as the dominant source with fast mobilization and short transit times to the receiving surface water. However, most studies have either focussed on smaller, hillslope and single catchment or on larger scale multi-catchment assessments. Moreover, information on the distribution of soil types in catchments is not always readily available. This study brings together both types of assessment in a data-driven top-down approach: (i) a detailed survey on DOC concentration and loads over the course of one year within two paired data-rich catchments discharging into a large drinking water reservoir in central Germany and (ii) a database of hydrochemistry and physio-geographic characteristics of 113 catchments draining into 58 reservoirs across Germany over the course of 16 years. The objective is to define hot spots of DOC export within the catchments for both types of assessments (i, ii) and to test the suitability of the topographic wetness index (TWI) as a proxy for well-connected wetland soils at various spatial scales. In the sub-catchments of assessment (i) the spatial variability of concentrations and loads was much smaller than expected. None of the studied sub-catchments was a predominant producer of the total DOC loads exported from the catchments. We found the mean concentrations and loads to be positively correlated with the share of groundwater-dominated soils in the sub

Designing a Dynamic Data Driven Application System for Estimating Real-Time Load of DOC in a River

NASA Astrophysics Data System (ADS)

Ouyang, Y.; None

2011-12-01

Understanding the dynamics of naturally occurring dissolved organic carbon (DOC) in a river is central to estimating surface water quality, aquatic carbon cycling, and climate change. Currently, determination of DOC in surface water is primarily accomplished by manually collecting samples for laboratory analysis, which requires at least 24 hours. In other words, no effort has been devoted to monitoring real-time variations of DOC in a river due to the lack of suitable and/or cost-effective wireless sensors. However, when considering human health, carbon footprints, and effects of urbanization, industry, and agriculture on water resource supply, timely DOC information may be critical. We have developed here a new paradigm, a dynamic data driven application system (DDDAS), for estimating the real-time load of DOC into a river. This DDDAS consisted of the following four components: (1) a Visual Basic (VB) program for downloading US Geological Survey real-time chlorophyll and discharge data; (2) a STELLA model for evaluating real-time DOC load based on the relationship between chlorophyll a, DOC, and river discharge; (3) a batch file for linking the VB program and STELLA model; and (4) a Microsoft Windows Scheduled Tasks wizard for executing the model and displaying output on a computer screen at selected times. Results show that the real-time load of DOC into the St. Johns River basin near Satsuma, Putnam County, Florida, USA varied over a range from -13,143 to 29,248 kg/h at the selected site in Florida, USA. The negative loads occurred because of the back flow in the estuarine reach of the river. The cumulative load of DOC in the river for the selected site at the end of the simulation (178 hours) was about 1.2 tons. Our results support the utility of the DDDAS developed in this study for estimating the real-time variations of DOC in river ecosystems.

Where does boreal stream DOC come from? - Quantifying the contribution from different landscape compartments using stable C isotope ratios.

NASA Astrophysics Data System (ADS)

Brink Bylund, J.; Bastviken, D.; Morth, C.; Laudon, H.; Giesler, R.; Buffam, I.

2007-12-01

Stable carbon isotope (δ13C) ratios are frequently used as a source tracer of e.g. organic matter (OM) produced in terrestrial versus aquatic environments. To our knowledge there has been no previous attempt to quantify the relative contribution of dissolved organic carbon (DOC) from various landscape compartments in catchments of different sizes. Here, we test to what extent δ13C values can be used also to quantify the relative contribution of DOC from wetlands/riparian zones along streams, and off stream forest habitats, respectively. We present data on spatial and temporal variability of DOC concentrations and δ13C-DOC values, during the year of 2005 in Krycklan catchment, a boreal stream network in northern Sweden. Ten stream sites, ranging from order 1 to 4, were monitored in sub catchments with different wetland coverage. Spatial variation of DOC concentration showed a weak but statistically significant relationship with wetland area, with higher concentration with increasing percent of wetland in the drainage area. During base flow the difference in δ13C-DOC values was significantly different between forest (-27.5‰) and wetland (-28.1‰). This spatial pattern disappears during spring peak flow when higher discharge flushing upper soil layer and the riparian zone on DOC in the catchments. A simple mixing model using DOC and δ13C-DOC showed that stream water DOC could be describe as a mixture of DOC coming from forest (deep) groundwater and wetland/riparian zone water. The result indicates that during spring peak flow almost all stream DOC (84-100%) is derived from wetlands and riparian zones. The wetland/riparian water dominates the stream DOC flux at all hydrological events, except for two sites, one forest dominated and one mixed catchment, where the forest groundwater dominated the DOC transport during base flow. Although the total wetland area in Krycklan catchment only represent 8.3%, it contributed, together with riparian zones, to as much as 83

Direct analysis of δ13C and concentration of dissolved organic carbon (DOC) in environmental samples by TOC-IRMS

NASA Astrophysics Data System (ADS)

Kirkels, Frédérique; Cerli, Chiara; Federherr, Eugen; Kalbitz, Karsten

2014-05-01

Dissolved organic carbon (DOC) plays an important role in carbon cycling in terrestrial and aquatic systems. Stable isotope analysis (delta 13C) of DOC could provide valuable insights in its origin, fluxes and environmental fate. Precise and routine analysis of delta 13C and DOC concentration are therefore highly desirable. A promising, new system has been developed for this purpose, linking a high-temperature combustion TOC analyzer trough an interface with a continuous flow isotope ratio mass spectrometer (Elementar group, Hanau, Germany). This TOC-IRMS system enables simultaneous stable isotope (bulk delta 13C) and concentration analysis of DOC, with high oxidation efficiency by high-temperature combustion for complex mixtures as natural DOC. To give delta 13C analysis by TOC-IRMS the necessary impulse for broad-scale application, we present a detailed evaluation of its analytical performance for realistic and challenging conditions inclusive low DOC concentrations and environmental samples. High precision (standard deviation, SD predominantly < 0.15 permil) and accuracy (R2 = 0.9997, i.e. comparison TOC-IRMS and conventional EA-IRMS) were achieved by TOC-IRMS for a broad diversity of DOC solutions. This precision is comparable or even slightly better than that typically reported for EA-IRMS systems, and improves previous techniques for δ13C analysis of DOC. Simultaneously, very good precision was obtained for DOC concentration measurements. Assessment of natural abundance and slightly 13C enriched DOC, a wide range of concentrations (0.2-150 mgC/L) and injection volumes (0.05-3 ml), demonstrated good analytical performance with negligible memory effects, no concentration/volume effects and a wide linearity. Low DOC concentrations (< 2 mgC/L), were correctly analyzed without any pre-concentration. Moreover, TOC-IRMS was successfully applied to analyze DOC from diverse terrestrial, freshwater and marine environments (SD < 0.23 permil). In summary, the TOC

A mobile water analysis laboratory for the study of stream nutrient and DOC dynamics

NASA Astrophysics Data System (ADS)

Echevarria Roman, Y.; Pullin, M. J.; Schwingle, R.; Gabrielsen, P. J.

2013-12-01

The dynamics of nutrient and dissolved organic carbon (DOC) quantity and composition in streams vary with season and in response to hydrologic events. Periodic grab sampling can capture some of this variation, but has also been shown to miss high flow events. Sampling during winter, during thunderstorms, and at night is difficult and sometimes hazardous. For these reasons, we have developed a mobile laboratory that autonomously determines pH, Eh, conductivity, dissolved oxygen, turbidity, nitrate, phosphate, DOC, DIC, as well as DOC fluorescence and absorbance continuously on a minutes timescale. The laboratory includes a Labview operated computer system that allows remote control and interaction with pumps, pressure, temperature, and flow sensors as well as the analytical instruments. Climate control allows for operation in winter. The design and operation of this laboratory will be presented. We will also discuss example data showing diurnal changes and responses to hydrologic events in DOC quantity and quality in the East Fork of the Jemez River, New Mexico.

Ionic strength and DOC determinations from various freshwater sources to the San Francisco Bay

USGS Publications Warehouse

Hunter, Y.R.; Kuwabara, J.S.

1994-01-01

An exact estimation of dissolved organic carbon (DOC) within the salinity gradient of zinc and copper metals is significant in understanding the limit to which DOC could influence metal speciation. A low-temperature persulfate/oxygen/ultraviolet wet oxidation procedure was utilized for analyzing DOC samples adapted for ionic strength from major freshwater sources of the northern and southern regions of San Francisco Bay. The ionic strength of samples was modified with a chemically defined seawater medium up to 0.7M. Based on the results, a minimum effect of ionic strength on oxidation proficiency for DOC sources to the Bay over an ionic strength gradient of 0.0 to 0.7 M was observed. There was no major impacts of ionic strength on two Suwanee River fulvic acids. In general, the noted effects associated with ionic strength were smaller than the variances seen in the aquatic environment between high- and low-temperature methods.

Local and regional scale exchanges of dissolved organic carbon (DOC) between tidal wetlands and their adjacent coastal waters

NASA Astrophysics Data System (ADS)

Osburn, C. L.; Joshi, I.; Lebrasse, M. C.; Oviedo-Vargas, D.; Bianchi, T. S.; Bohnenstiehl, D. R.; D'Sa, E. J.; He, R.; Ko, D.; Arellano, A.; Ward, N. D.

2017-12-01

The contribution of blue carbon from tidal wetlands to the coastal ocean in the form of dissolved organic carbon (DOC) represents a terrestrial-aquatic linkage of increasing importance. DOC flux results will be presented from local (tidal creek) and regional (bays) scale studies in which various combinations of field observations, ocean-color satellite observations, and the outputs of high-resolution hydrodynamic models were used to estimate DOC export. The first project was located in Bald Head Creek, a tributary to the Cape Fear River estuary in eastern North Carolina (NC). DOC fluxes were computed using a bathymetric data collected via unmanned surface vehicle (USV) and a numerical hydrodynamic model (SCHISM) based on the relationships between colored dissolved organic matter (CDOM) absorption, DOC concentration, and salinity taken from field observations. Model predictions estimated an annual net export of DOC at 54 g C m-2 yr-1 from the tidal creek to the adjacent estuary. Carbon stable isotope (δ13C) values were used to estimate the contribution of wetland carbon to this export. In the second project, DOC fluxes from the Apalachicola Bay, FL, Barataria Bay, LA, were based on the development of algorithms between DOC and CDOM absorption derived from the VIIRS ocean color sensor. The Navy Coastal Ocean Model (NCOM) was used to compute salt flux estimates from each bay to the Louisiana-Texas shelf. The relationship between salinity and CDOM was used to estimate net annual DOC exports of 8.35 x 106 g C m-2 y-1 (Apalachicola Bay) and 7.14 x 106 g C m-2 yr-1 (Barataria Bay). These values approximate 13% and 9% of the annual loads of DOC from the Mississippi River to the Gulf of Mexico, respectively. CDOM and lignin were used in a mixing model to estimate wetland-derived DOC were 2% for Apalachicola Bay and 13% for Barataria Bay, the latter having one of the highest rates of relative sea level rise in North America. Results from our project demonstrated the utility

Characterisation of DOC and its relation to the deep terrestrial biosphere

NASA Astrophysics Data System (ADS)

Vieth, Andrea; Vetter, Alexandra; Sachse, Anke; Horsfield, Brian

2010-05-01

The deep subsurface is populated by a large number of microorganisms playing a pivotal role in the carbon cycling. The question arises as to the origin of the potential carbon sources that support deep microbial communities and their possible interactions within the deep subsurface. As the carbon sources need to be dissolved in formation fluids to become available to microorganisms, the dissolved organic carbon (DOC) needs further characterisation as regards concentration, structural as well as molecular composition and origin. The Malm carbonates in the Molasse basin of southern Germany are of large economic potential as they are targets for both hydrocarbon and geothermal exploration (ANDREWS et al., 1987). Five locations that differ in their depth of the Malm aquifer between 220 m and 3445 m below surface have been selected for fluid sampling. The concentration and the isotopic composition of the DOC have been determined. To get a better insight into the structural composition of the DOC, we also applied size exclusion chromatography and quantified the amount of low molecular weight organic acids (LMWOA) by ion chromatography. With increasing depth of the aquifer the formation fluids show increasing salinity as chloride concentrations increase from 2 to 300 mg/l and also the composition of the DOC changes. Water samples from greater depth (>3000 m) showed that the DOC mainly consists of LMWOA (max. 83 %) and low percentages of neutral compounds (alcohols, aldehyde, ketones, amino acids) as well as "building blocks". Building blocks have been described to be the oxidation intermediates from humic substances to LMWOA. With decreasing depth of the aquifer, the DOC of the fluid becomes increasingly dominated by neutral compounds and the percentage of building blocks increases to around 27%. The fluid sample from 220 m depth still contains a small amount of humic substances. The DOC of formation fluids in some terrestrial sediments may originate from organic

Does wildfire cause cascading effects on aquatic C cycling? A study of soil, well and lake DOC composition and bio/photolability

NASA Astrophysics Data System (ADS)

Olefeldt, D.; Turetsky, M. R.; Devito, K. J.; Blodau, C.

2012-12-01

In May 2011 a wildfire broke out north of Utikuma Lake in central Alberta, Canada, which eventually burned an area of ~880 km2. Wildfire alters soil properties, potentially altering the chemical composition of terrestrial DOC that reaches downstream aquatic environments. In order to study the potential effects of wildfire on lake carbon cycling, we sampled and incubated DOC from soil samples (n=52), wells (n=35) and lakes (n=32) from within and outside the recent fire perimeter. We incubated the DOC samples under both dark and UV conditions to assess both bio- and photolability, and followed DOC composition throughout the incubations by measuring DOC absorbing and fluorescing properties. A strong effect of wildfire was found among DOC samples leached from surface peatland and upland soils - with fire yielding increased DOC aromaticity associated with decreased biodegradability but also increased photolability. Parallel factor analysis of fluorescence matrices revealed distinct regions that were associated with DOC leached from charred soils, potentially linked to their lower biodegradability. Dark and UV conditions gave rise to very different trajectories of changes to DOC composition throughout incubations, with preferential losses of non-aromatic DOC under dark conditions and aromatic DOC under UV conditions. The DOC composition index that was found to best predict both DOC bio- and photolability was specific UV absorbance, which is also a very simple and quick index to measure. For lakes, we found that the primary influences on DOC composition and bio-/photolability was linked to lake size and hydrogeological setting (whether located on a lacustrine clay plain or in a moraine/outwash region) that controls groundwater influence and the hydrological connectivity to adjacent peatlands. Further analysis of well and lake water incubations will be used to detect whether wildfire can be detected to have a subtle secondary effect on DOC composition and lability or if

Effect of disinfection upon dissolved organic carbon (DOC) in wastewater: bacterial bioassays.

PubMed

Arana, I; Santorum, P; Muela, A; Barcina, I

2000-08-01

Quantitative and qualitative changes in organic matter content of wastewater effluents attributable to chlorination and ozonation have been analysed using bioassays as well as organic carbon direct measures. Bioassays were carried out using the bacterial populations of wastewater and two Escherichia coli strains as test micro-organisms. Our results indicate that pure strains present some advantages over indigenous bacteria. Although wastewater bacterial populations are better adapted to growth in wastewater, E. coli strains are more sensitive to changes in dissolved organic carbon (DOC) content. Moreover, the use of pure cultures allows estimation of the portion of DOC which can be converted in cell biomass, the assimilable organic carbon (AOC). Finally, the results obtained using prototrophic and the auxotrophic strains of E. coli suggested that ozonation alters the amino acid composition of wastewater while chlorination does not change the quantity nor the quality of the DOC present in effluents.

Duplicate document detection in DocBrowse

NASA Astrophysics Data System (ADS)

Chalana, Vikram; Bruce, Andrew G.; Nguyen, Thien

1998-04-01

Duplicate documents are frequently found in large databases of digital documents, such as those found in digital libraries or in the government declassification effort. Efficient duplicate document detection is important not only to allow querying for similar documents, but also to filter out redundant information in large document databases. We have designed three different algorithm to identify duplicate documents. The first algorithm is based on features extracted from the textual content of a document, the second algorithm is based on wavelet features extracted from the document image itself, and the third algorithm is a combination of the first two. These algorithms are integrated within the DocBrowse system for information retrieval from document images which is currently under development at MathSoft. DocBrowse supports duplicate document detection by allowing (1) automatic filtering to hide duplicate documents, and (2) ad hoc querying for similar or duplicate documents. We have tested the duplicate document detection algorithms on 171 documents and found that text-based method has an average 11-point precision of 97.7 percent while the image-based method has an average 11- point precision of 98.9 percent. However, in general, the text-based method performs better when the document contains enough high-quality machine printed text while the image- based method performs better when the document contains little or no quality machine readable text.

The sensitivity of peat soil and peatland vegetation to drought: release of dissolved organic carbon (DOC) on rewetting

NASA Astrophysics Data System (ADS)

Ritson, Jonathan; Graham, Nigel; Templeton, Michael; Freeman, Christopher; Clark, Joanna

2015-04-01

Organic rich peat soils are a major store of carbon worldwide. Their existence is predicated on high year-round water tables which create an anoxic environment, thus limiting decay, and also to the recalcitrance of plant litter (dead plant material) commonly found in peatland areas. Climate change threatens the stability of peat soils by altering the biogeochemical cycles which control plant decay, lowering water tables so that oxic degradation can occur and by changing habitat niches such that less recalcitrant species can thrive in peatlands. One of the major fluxes of carbon from peatlands is through dissolved organic carbon (DOC) in surface waters. As peatland areas in the UK are often used as source waters for drinking water supply this presents a problem to water utilities as DOC must be effectively removed to limit colour, odour and the formation of potentially carcinogenic by-products on disinfection. Changes in catchment vegetation may occur due to climate change, nutrient deposition and changing bioclimatic envelopes. How different peatland vegetation contribute to DOC flux and how this may change in the future is therefore of interest. A six week laboratory simulation was performed on typical peatland litter (Sphagnum spp., Calluna vulgaris, Molinea caerulea, Juncus effusus) and a peat soil collected from Exmoor National Park, UK. The simulation monitored DOC flux from the decaying litter/soil and considered the impact of different drought severities using the 50th, 25th, 10th and 5th percentiles of the mean July/August monthly rainfall for Exmoor. On rewetting following the drought, all sources produced significantly different amounts of DOC (Tukey HSD p<0.05) in the order Molinia>Juncus>Calluna>Sphagnum>peat. The source also had a significant (ANOVA p<0.001) effect on coagulation removal efficiency, a typical method of removing DOC during drinking water treatment, with Juncus DOC proving the easiest to remove whilst Sphagnum DOC was the most difficult

Absorption features of chromophoric dissolved organic matter (CDOM) and tracing implication for dissolved organic carbon (DOC) in Changjiang Estuary, China

NASA Astrophysics Data System (ADS)

Zhang, X. Y.; Chen, X.; Deng, H.; Du, Y.; Jin, H. Y.

2013-07-01

Chromophoric dissolved organic matter (CDOM) represents the light absorbing fraction of dissolved organic carbon (DOC). Studies have shown that the optical properties of CDOM can be used to infer the distribution and diffusion characteristics of DOC in the estuary and coastal zone. The inversion of DOC concentrations from remote sensing has been implemented in certain regions. In this study we investigate the potential of tracing DOC from CDOM by the measurement of DOC, absorption spectrum of CDOM, Chla concentration, suspended sediment (SS), and salinity from cruises in different seasons around the Changjiang estuary. Our results show that around the Changjiang estuary the absorption coefficients of CDOM in general have the similar spatial and temporal characteristics as that of DOC, but the strength of the correlation between CDOM and DOC varies locally and seasonally. The input of pollutants from outside the estuary, the bloom of phytoplankton in spring, re-suspension of deposited sediment, and light bleaching all contribute to the local and seasonal variation of the correlation between DOC and CDOM. An inversion model for the determination of DOC from CDOM is established, but the stability of model parameters and its application in different environments need further study. We find that relative to the absorption coefficient of CDOM, the fitted parameters of the absorption spectrum of DOM are better indictors for the composition of DOC. In addition, it is found that the terrestrial input of DOC to Changjiang estuary is a typical two-stage dilution process instead of a linear diffusion process.

Hydrologic and forest management controls on DOC dynamics in the small watersheds of the H.J. Andrews Experimental Forest, OR

NASA Astrophysics Data System (ADS)

Lajtha, K.; Jones, J. A.

2016-12-01

Dissolved organic carbon (DOC) export from hillslopes to streams is an important component of the carbon cycle of a catchment and may be a critical source of energy for the aquatic food web in receiving waters. Using a long-term record of DOC and other dissolved nutrients and elements from paired watersheds from the H.J. Andrews Experimental Forest in Oregon, we explored hydrologic, climatic, and land-use controls on seasonal and inter-annual patterns of DOC flux in a seasonally dry ecosystem. Seasonal patterns of DOC flux demonstrated source limitations to DOC export, with DOC concentrations highest immediately following the first rains after a dry summer, and lowest after winter rains. In contrast, more geochemically-controlled elements showed simple dilution-concentration patterns with no seasonal hysteresis. Inter-annual patterns of DOC flux, however, did not provide evidence of source limitation, with DOC flux within a watershed tightly correlated to total discharge but not temperature. Among watersheds, forest harvest, even over 50 years ago, significantly reduced DOC flux but not fluxes of other elements including N; this response was linked to the loading of coarse woody debris to the forest floor. Chemical fingerprinting of DOC revealed that old-growth watersheds had higher fluxes of DOC characteristic of forest floor organic materials, likely delivered to streams through more surficial preferential flow pathways not subject to microbial alteration, respiration, or sorption losses. Taken together these results suggest that the biogeochemical composition of forested streams reflects both current hydrologic patterns and also processes that occurred many decades ago within the catchment.

Declines in the dissolved organic carbon (DOC) concentration and flux from the UK

NASA Astrophysics Data System (ADS)

Worrall, Fred; Howden, Nicholas J. K.; Burt, Tim P.; Bartlett, Rebecca

2018-01-01

Increased concentrations of dissolved organic carbon (DOC) have been reported for many catchments across the northern hemisphere. Hypotheses to explain the increase have varied (eg. increasing air temperature or recovery from acidification) but one test of alternative hypotheses is the trend over the recent decade, with the competing hypotheses predicting: continuing increase; the rate of increase declining with time; and even decrease in concentration. In this study, records of DOC concentration in non-tidal rivers across the UK were examined for the period 2003-2012. The study found that: Of the 62 decade-long concentration trends that could be examined, 3 showed a significant increase, 17 experienced no significant change and 42 showed a significant decrease; in 28 of the 42 significant decreases, a significant step change was apparent with step changes being a decrease in concentration in every case. Of the 118 sites where annual flux and concentration records were available from 1974, 28 showed a significant step change down in flux and 52 showed a step down in concentration. The modal year of the step changes was 2000 with no step changes observed before 1982. At the UK national scale, DOC flux peaked in 2005 at 1354 ktonnes C/yr (5.55 tonnes C/km2/yr) but has declined since. The study suggests that there is a disconnection between DOC records from large catchments at their tidal limits and complementary records from headwater catchments, which means that mechanisms believed to be driving increases in DOC concentrations in headwaters will not necessarily be those controlling trends in DOC concentration further downstream. We propose that the changes identified here have been driven by changes in in-stream processing and changes brought about by the Urban Waste Water Treatment Directive. Therefore, signals identified in headwater catchments may bear little relation to those observed in large rivers much further downstream and vice versa.

Chronic widespread musculoskeletal pain, fatigue, depression and disordered sleep in chronic post-SARS syndrome; a case-controlled study.

PubMed

Moldofsky, Harvey; Patcai, John

2011-03-24

The long term adverse effects of Severe Acute Respiratory Syndrome (SARS), a viral disease, are poorly understood. Sleep physiology, somatic and mood symptoms of 22 Toronto subjects, 21 of whom were healthcare workers, (19 females, 3 males, mean age 46.29 yrs.+/- 11.02) who remained unable to return to their former occupation (mean 19.8 months, range: 13 to 36 months following SARS) were compared to 7 healthy female subjects. Because of their clinical similarities to patients with fibromyalgia syndrome (FMS) these post-SARS subjects were similarly compared to 21 drug free female patients, (mean age 42.4 +/- 11.8 yrs.) who fulfilled criteria for fibromyalgia. Chronic post-SARS is characterized by persistent fatigue, diffuse myalgia, weakness, depression, and nonrestorative sleep with associated REM-related apneas/hypopneas, an elevated sleep EEG cyclical alternating pattern, and alpha EEG sleep anomaly. Post- SARS patients had symptoms of pre and post-sleep fatigue and post sleep sleepiness that were similar to the symptoms of patients with FMS, and similar to symptoms of patients with chronic fatigue syndrome. Both post-SARS and FMS groups had sleep instability as indicated by the high sleep EEG cyclical alternating pattern rate. The post-SARS group had a lower rating of the alpha EEG sleep anomaly as compared to the FMS patients. The post-SARS group also reported less pre-sleep and post-sleep musculoskeletal pain symptoms. The clinical and sleep features of chronic post-SARS form a syndrome of chronic fatigue, pain, weakness, depression and sleep disturbance, which overlaps with the clinical and sleep features of FMS and chronic fatigue syndrome.

DocML: A Digital Library of University Data.

ERIC Educational Resources Information Center

Papadakis, Ioannis; Karakoidas, Vassileios; Chrissikopoulos, Vassileios

2002-01-01

Describes DocML, a Web-based digital library of university data that is used to build a system capable of preserving and managing student assignments. Topics include requirements for a digital library of university data; metadata and XML; three-tier architecture; user interface; searching; browsing; content delivery; and administrative issues.…

Impact of catchment geophysical characteristics and climate on the regional variability of dissolved organic carbon (DOC) in surface water.

PubMed

Cool, Geneviève; Lebel, Alexandre; Sadiq, Rehan; Rodriguez, Manuel J

2014-08-15

Dissolved organic carbon (DOC) is a recognized indicator of natural organic matter (NOM) in surface waters. The aim of this paper is twofold: to evaluate the impact of geophysical characteristics, climate and ecological zones on DOC concentrations in surface waters and, to develop a statistical model to estimate the regional variability of these concentrations. In this study, multilevel statistical analysis was used to achieve three specific objectives: (1) evaluate the influence of climate and geophysical characteristics on DOC concentrations in surface waters; (2) compare the influence of geophysical characteristics and ecological zones on DOC concentrations in surface waters; and (3) develop a model to estimate the most accurate DOC concentrations in surface waters. The case study involved 115 catchments from surface waters in the Province of Quebec, Canada. Results showed that mean temperatures recorded 60 days prior to sampling, total precipitation 10 days prior to sampling and percentages of wetlands, coniferous forests and mixed forests have a significant positive influence on DOC concentrations in surface waters. The catchment mean slope had a significant negative influence on DOC concentrations in surface waters. Water type (lake or river) and deciduous forest variables were not significant. The ecological zones had a significant influence on DOC concentrations. However, geophysical characteristics (wetlands, forests and slope) estimated DOC concentrations more accurately. A model describing the variability of DOC concentrations was developed and can be used, in future research, for estimating DBPs in drinking water as well evaluating the impact of climate change on the quality of surface waters and drinking water. Copyright © 2014 Elsevier B.V. All rights reserved.

Conceptualizing the seasonal and hydrological dynamics of riparian zone control on DOC in boreal headwater streams

NASA Astrophysics Data System (ADS)

Winterdahl, M.; Laudon, H.; Köhler, S.; Seibert, J.; Bishop, K.

2009-04-01

Dissolved organic material (DOM) plays a key role in many natural surface waters. Despite the importance of DOC for the hydrochemistry in boreal headwaters there are few models that conceptualize the controls on short-term variability in stream DOC. A relatively simple model has been proposed where the vertical profile of DOC in the riparian soil solution, serves as an instantaneous "chemostat" setting the DOC of laterally flowing groundwater just before it enters the stream. This paper considers whether the addition of seasonality (in the form of soil temperature) and antecedent flows can improve the predictions of daily DOC concentrations. The model was developed and tested using field data from the Krycklan catchment on the Svartberget Research Station in northern Sweden where a transect of soil solution sampling sites equipped with suction lysimeters and wells for monitoring groundwater level have been installed and monitored for over a decade. The field data showed an exponential correlation between depth and DOC concentration in the soil solution. There was also an exponential correlation between stream discharge and groundwater table position. The expressions for these two correlations (exponential functions) have been combined into a simple riparian DOC model. To simulate effects of seasonality and/or antecedent flow, modules for soil temperature evolution and/or groundwater flow were added and tested. The model was calibrated and tested against 8 years of data from the Västrabäcken headwater catchment in the Krycklan area. To estimate the uncertainty in the model and the observed data a Hornberger-Spear-Young sensitivity analysis together with a GLUE uncertainty analysis was performed.

Non-linear, connectivity and threshold-dominated runoff-generation controls DOC and heavy metal export in a small peat catchment

NASA Astrophysics Data System (ADS)

Birkel, Christian; Broder, Tanja; Biester, Harald

2017-04-01

Peat soils act as important carbon sinks, but they also release large amounts of dissolved organic carbon (DOC) to the aquatic system. The DOC export is strongly tied to the export of soluble heavy metals. The accumulation of potentially toxic substances due to anthropogenic activities, and their natural export from peat soils to the aquatic system is an important health and environmental issue. However, limited knowledge exists as to how much of these substances are mobilized, how they are mobilized in terms of flow pathways and under which hydrometeorological conditions. In this study, we report from a combined experimental and modelling effort to provide greater process understanding from a small, lead (Pb) and arsenic (As) contaminated upland peat catchment in northwestern Germany. We developed a minimally parameterized, but process-based, coupled hydrology-biogeochemistry model applied to simulate detailed hydrometric and biogeochemical data. The model was based on an initial data mining analysis, in combination with regression relationships of discharge, DOC and element export. We assessed the internal model DOC-processing based on stream-DOC hysteresis patterns and 3-hourly time step groundwater level and soil DOC data (not used for calibration as an independent model test) for two consecutive summer periods in 2013 and 2014. We found that Pb and As mobilization can be efficiently predicted from DOC transport alone, but Pb showed a significant non-linear relationship with DOC, while As was linearly related to DOC. The relatively parsimonious model (nine calibrated parameters in total) showed the importance of non-linear and rapid near-surface runoff-generation mechanisms that caused around 60% of simulated DOC load. The total load was high even though these pathways were only activated during storm events on average 30% of the monitoring time - as also shown by the experimental data. Overall, the drier period 2013 resulted in increased nonlinearity, but

48 CFR 1323.404-70 - DOC affirmative procurement program.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false DOC affirmative procurement program. 1323.404-70 Section 1323.404-70 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES...

48 CFR 1323.404-70 - DOC affirmative procurement program.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false DOC affirmative procurement program. 1323.404-70 Section 1323.404-70 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES...

48 CFR 1323.404-70 - DOC affirmative procurement program.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false DOC affirmative procurement program. 1323.404-70 Section 1323.404-70 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES...

Patterns in DOC Concentration and Composition in Tundra Watersheds in the Kolyma River Basin

NASA Astrophysics Data System (ADS)

Behnke, M. I.; Schade, J. D.; Fiske, G. J.; Whittinghill, K. A.; Zimov, N.

2014-12-01

Much of the world's soil carbon is frozen in permafrost in the Arctic. As the climate warms and permafrost thaws, this carbon will again be actively cycled. Whether it is exported to the ocean or released as greenhouse gases to the atmosphere depends on the form of carbon compounds and conditions encountered during transport, and will determine the strength of permafrost thaw as a feedback on climate change. To better understand the fate of this carbon, we determined how and where in the landscape dissolved organic carbon (DOC) breaks down as water transports it from tundra to ocean. We compared DOC concentration and composition along flowpaths within watersheds and at the mouths of watersheds differing in drainage area. We incubated filtered water samples in light and dark, including filter-sterilized samples, to assess the interactions between light and microbial processing as mechanisms of DOC loss. Composition was assessed using optical measurements associated with the structure of organic compounds. DOC concentration declined along flowpaths within watersheds, with most loss occurring in aquatic environments high in the landscape. We also found a negative correlation between watershed size and DOC concentration. These results suggest that much of the processing of organic carbon occurs in small streams. In addition, the relationship with drainage area suggests that residence time in streams has a large impact on transformation of terrestrial carbon during transport. We found no substantial differences in optical characteristics of DOC, indicating that breakdown processes were not selective, and that light caused much of the breakdown. This conclusion is supported by the incubation experiment, which showed greater breakdown by light, and evidence that light stimulated higher rates of microbial processing. These results highlight the importance of inland aquatic ecosystems as processors of organic matter, and suggest that organic carbon from permafrost thaw is

ORCHIDEE-SOM: modeling soil organic carbon (SOC) and dissolved organic carbon (DOC) dynamics along vertical soil profiles in Europe

NASA Astrophysics Data System (ADS)

Camino-Serrano, Marta; Guenet, Bertrand; Luyssaert, Sebastiaan; Ciais, Philippe; Bastrikov, Vladislav; De Vos, Bruno; Gielen, Bert; Gleixner, Gerd; Jornet-Puig, Albert; Kaiser, Klaus; Kothawala, Dolly; Lauerwald, Ronny; Peñuelas, Josep; Schrumpf, Marion; Vicca, Sara; Vuichard, Nicolas; Walmsley, David; Janssens, Ivan A.

2018-03-01

Current land surface models (LSMs) typically represent soils in a very simplistic way, assuming soil organic carbon (SOC) as a bulk, and thus impeding a correct representation of deep soil carbon dynamics. Moreover, LSMs generally neglect the production and export of dissolved organic carbon (DOC) from soils to rivers, leading to overestimations of the potential carbon sequestration on land. This common oversimplified processing of SOC in LSMs is partly responsible for the large uncertainty in the predictions of the soil carbon response to climate change. In this study, we present a new soil carbon module called ORCHIDEE-SOM, embedded within the land surface model ORCHIDEE, which is able to reproduce the DOC and SOC dynamics in a vertically discretized soil to 2 m. The model includes processes of biological production and consumption of SOC and DOC, DOC adsorption on and desorption from soil minerals, diffusion of SOC and DOC, and DOC transport with water through and out of the soils to rivers. We evaluated ORCHIDEE-SOM against observations of DOC concentrations and SOC stocks from four European sites with different vegetation covers: a coniferous forest, a deciduous forest, a grassland, and a cropland. The model was able to reproduce the SOC stocks along their vertical profiles at the four sites and the DOC concentrations within the range of measurements, with the exception of the DOC concentrations in the upper soil horizon at the coniferous forest. However, the model was not able to fully capture the temporal dynamics of DOC concentrations. Further model improvements should focus on a plant- and depth-dependent parameterization of the new input model parameters, such as the turnover times of DOC and the microbial carbon use efficiency. We suggest that this new soil module, when parameterized for global simulations, will improve the representation of the global carbon cycle in LSMs, thus helping to constrain the predictions of the future SOC response to global

panMetaDocs, eSciDoc, and DOIDB - an infrastructure for the curation and publication of file-based datasets for 'GFZ Data Services'

NASA Astrophysics Data System (ADS)

Ulbricht, Damian; Elger, Kirsten; Bertelmann, Roland; Klump, Jens

2016-04-01

With the foundation of DataCite in 2009 and the technical infrastructure installed in the last six years it has become very easy to create citable dataset DOIs. Nowadays, dataset DOIs are increasingly accepted and required by journals in reference lists of manuscripts. In addition, DataCite provides usage statistics [1] of assigned DOIs and offers a public search API to make research data count. By linking related information to the data, they become more useful for future generations of scientists. For this purpose, several identifier systems, as ISBN for books, ISSN for journals, DOI for articles or related data, Orcid for authors, and IGSN for physical samples can be attached to DOIs using the DataCite metadata schema [2]. While these are good preconditions to publish data, free and open solutions that help with the curation of data, the publication of research data, and the assignment of DOIs in one software seem to be rare. At GFZ Potsdam we built a modular software stack that is made of several free and open software solutions and we established 'GFZ Data Services'. 'GFZ Data Services' provides storage, a metadata editor for publication and a facility to moderate minted DOIs. All software solutions are connected through web APIs, which makes it possible to reuse and integrate established software. Core component of 'GFZ Data Services' is an eSciDoc [3] middleware that is used as central storage, and has been designed along the OAIS reference model for digital preservation. Thus, data are stored in self-contained packages that are made of binary file-based data and XML-based metadata. The eSciDoc infrastructure provides access control to data and it is able to handle half-open datasets, which is useful in embargo situations when a subset of the research data are released after an adequate period. The data exchange platform panMetaDocs [4] makes use of eSciDoc's REST API to upload file-based data into eSciDoc and uses a metadata editor [5] to annotate the files

Long-term environmental drivers of DOC fluxes: Linkages between management, hydrology and climate in a subtropical coastal estuary

NASA Astrophysics Data System (ADS)

Regier, Peter; Briceño, Henry; Jaffé, Rudolf

2016-12-01

Urban and agricultural development of the South Florida peninsula has disrupted historic freshwater flow in the Everglades, a hydrologically connected ecosystem stretching from central Florida to the Gulf of Mexico, USA. Current system-scale restoration efforts aim to restore natural hydrologic regimes to reestablish pre-drainage ecosystem functioning through increased water availability, quality and timing. Aquatic transport of carbon in this ecosystem, primarily as dissolved organic carbon (DOC), plays a critical role in biogeochemical cycling and food-web dynamics, and will be affected both by water management policies and climate change. To better understand DOC dynamics in South Florida estuaries and how hydrology, climate and water management may affect them, 14 years of monthly data collected in the Shark River estuary were used to examine DOC flux dynamics in a broader environmental context. Multivariate statistical methods were applied to long-term datasets for hydrology, water quality and climate to untangle the interconnected environmental drivers that control DOC export at monthly and annual scales. DOC fluxes were determined to be primarily controlled by hydrology but also by seasonality and long-term climate patterns and episodic weather events. A four-component model (salinity, rainfall, inflow, Atlantic Multidecadal Oscillation) capable of predicting DOC fluxes (R2 = 0.84, p < 0.0001, n = 155) was established and applied to potential climate change scenarios for the Everglades to assess DOC flux response to climate and restoration variables. The majority of scenario runs indicated that DOC export from the Everglades is expected to decrease due to future changes in rainfall, water management and salinity.

Retention of young female post-doc physics researchers in the UK

NASA Astrophysics Data System (ADS)

Whitelegg, Elizabeth

2004-03-01

The talk will describe the results of a research project to investigate the problems young women physics researchers encountered during early stages of their careers and their perceptions of the longer-term difficulties they anticipated were they to pursue a career in physics research. The project examined quantitative data from a large sample of female members of the UK Institute of Physics (IOP) and qualitative data from intensive interviews with 27 young female doctoral and post-doctoral researchers at an early stage in their careers. In the survey of women PhD members of the IOP, only 15% of the younger women (aged under 30) said they had encountered gender barriers compared with 45% of older women. However, within a few years of completing their PhDs only 25% of the young women remained in physics research although they had previously aspired to work in this area. The reasons given for leaving physics included a dislike of the male culture or atmosphere in research labs, the fact that few of the young women thought that they would ever attain a senior physics post, concerns about balancing a research career with raising a young family and anticipating a need to relocate to match a partners career moves. These are clearly gender-related barriers and constraints although these young women often did not perceive them in this way. This research examines the notion of direct and indirect gender barriers. It addresses the idea of subtle discrimination by examining both institutional employment practices and the prevalent male culture or atmosphere in physics research, which contribute to the leaky pipeline in womens physics employment in the UK.

Climatic and chemical drivers of trends in DOC in northern surface waters in Europa and North America

NASA Astrophysics Data System (ADS)

de Wit, Heleen A.; Monteith, Don T.; Stoddard, John L.

2016-04-01

Concentrations of DOC in boreal surface waters have increased to levels that create challenges for water treatment plants, and that potentially impact lake habitat through increased anoxia and thermal mixing, and productivity. Aquatic transport of DOC from land to oceans is likely to increase, even if runoff patterns would remain stable. Reduced acid deposition appears to be a dominant driver behind the increase in DOC concentrations, through increasing organic matter solubility. We hypothesize that the higher solubility of organic matter makes DOC more susceptible to climate change. Here, we present trends in DOC from circa 500 lakes and streams in subarctic, boreal and temperate headwater catchments in Europe (UK, Fennoscandia, Czech Republic, Slovakia) and North America (Northeastern US, Ontario, Atlantic Canada) from 1990 until 2012; an extension of the trend analysis presented in Monteith et al. (2007). The water chemical data stem from national monitoring networks, assembled by the ICP Waters network. Sampling frequencies vary from 1 to 52 samples per year. Climate data were obtained from Climate Research Unit in the UK. Trends were calculated using the Mann-Kendall test and the Sen-slope estimator. We test 1) if DOC responds to changes in the rate of decline in acid deposition, and 2) if trends in temperature and precipitation affect trends and variability in DOC. Positive trends dominate: the median (±2.5% quartile) of the absolute and relative DOC trends is +0.06 (+0.36 to -0.02) mg C L-1 yr-1 and +1.4 (+4.7 to -0.9) % yr-1, respectively. Overall, the trends do not level off when comparing 1990-2004, and 1998-2012, except in the UK and Atlantic Canada. These two regions are strongly impacted by seasalt deposition but may also experience stronger warming than elsewhere. The response of DOC to changes in SO4 (expressed as trend ratios) is stronger in 1998-2012 than in 1990-2004. We will explore whether this changing relates to increasing dominance of

The geomicrobiology of the Greenland Ice Sheet: impact on DOC export (Invited)

NASA Astrophysics Data System (ADS)

Wadham, J. L.; Stibal, M.; Lawson, E. C.; Barnett, M. J.; Hasan, F.; Telling, J.; Anesio, A.; Lis, G.; Cullen, D.; Butler, C.; Tranter, M.; Nienow, P. W.

2010-12-01

The Greenland Ice Sheet (GrIS) is the largest mass of ice in the northern hemisphere, and contributes ~370 km3 in runoff annually to the Arctic Ocean. While recent work has highlighted runoff increases of up to 100% from the GrIS over the next century, very little is known about the associated impacts upon rates of sediment-bound and dissolved organic carbon export from the ice sheet to the coastal ocean. This is relevant given recent work that has suggested that the high proportion of labile dissolved organic carbon (DOC) present in glacial runoff may be important in sustaining the productivity of ecosystems downstream. Here we report the phylogenetic and functional diversity of micro-organisms inhabiting the surface and basal regions of the Greenland Ice Sheet (at Leverett Glacier, SW Greenland), and whose activity influences the biogeochemical composition of runoff. Real time PCR data on runoff, together with 16S-rRNA bacterial clone libraries on sediments, demonstrate a subglacial microbial community that contrasts phylogenetically and functionally with the ice sheet surface ecosystem. We envisage that large sectors of the subglacial environment are microbially active, with overridden paleosols and in-washed surface organic matter providing a carbon substrate for a range of metabolic pathways. This includes methanogenesis which proceeds at rates similar to deep ocean sediments and via a CO2/H2 pathway. These subglacial microbial communities serve to chemically modify the DOC composition of meltwater inputs from the ice sheet surface and modulate the reactivity of bulk DOC exported in runoff. Evidence for subglacial microbial influences on DOC in runoff includes elevated concentrations of dissolved carbohydrates (e.g. glucose and fructose of up to 1 μmol/L), which are preferentially exported during subglacial outburst events. We examine the temporal changes in DOC export in runoff from the ice sheet over a full melt season, and consider how changes in total

Scaling Effects of Riparian Peatlands on Stable Isotopes in Runoff and DOC Mobilization

NASA Astrophysics Data System (ADS)

Tetzlaff, D.; Tunaley, C.; Soulsby, C.

2016-12-01

We combined 13 months of daily isotope measurements in stream water with daily DOC and 15 minute FDOM (fluorescent component of dissolved organic matter) data at three nested scales to identify how riparian peatlands generate runoff and influence DOC dynamics in streams. We investigated how runoff generation processes in a small, riparian peatland dominated headwater catchment (0.65 km2) propagate to larger scales (3.2 km2 and 31 km2) with decreasing percentage of riparian peatland coverage. Isotope damping was most pronounced in the 0.65 km2 headwater catchment due to high water storage in the organic soils which encourage tracer mixing. At the largest scale, stream flow and water isotope dynamics showed a more flashy response. The isotopic difference between the sites was most pronounced in the summer months when stream water signatures were enriched. During the winter months, the inter-site difference reduced. The isotopes also revealed evaporative fractionation in the peatland dominated catchment, in particular during summer low flows, which implied high hydrological connectivity in form of constant seepage from the peatlands sustaining high baseflows at the headwater scale. This connectivity resulted in high DOC concentrations at the peatland site during baseflow ( 5 mg l-1). In contrast, at the larger scales, DOC was minimal during low flows ( 2 mg l-1) due to increased groundwater influence and the disconnection between DOC sources and the stream. High frequency data also revealed diel variability during low flows. Insights into event dynamics through the analysis of hysteresis loops showed slight dilution on the rising limb, the strong influence of dry antecedent conditions and a quick recovery between events at the riparian peatland site. Again, these dynamics are driven by the tight coupling and high connectivity of the landscape to the stream. At larger scales, the disconnection between the landscape units increase and the variable connectivity controls

Scaling effects of riparian peatlands on stable isotopes in runoff and DOC mobilisation

NASA Astrophysics Data System (ADS)

Tunaley, C.; Tetzlaff, D.; Soulsby, C.

2017-06-01

We combined 13 months of daily isotope measurements in stream water with daily DOC and 15 min FDOM (fluorescent component of dissolved organic matter) data at three nested scales to identify how riparian peatlands generate runoff and influence DOC dynamics in streams. We investigated how runoff generation processes in a small, riparian peatland-dominated headwater catchment (0.65 km2) propagate to larger scales (3.2 km2 and 31 km2) with decreasing percentage of riparian peatland coverage. Isotope damping was most pronounced in the 0.65 km2 headwater catchment due to high water storage in the organic soils encouraging tracer mixing. At the largest scale, stream flow and water isotope dynamics showed a more flashy response. The isotopic difference between the sites was most pronounced in the summer months when stream water signatures were enriched. During the winter months, the inter-site difference reduced. The isotopes also revealed evaporative fractionation in the peatland dominated catchment, in particular during summer low flows, which implied high hydrological connectivity in the form of constant seepage from the peatlands sustaining high baseflows at the headwater scale. This connectivity resulted in high DOC concentrations at the peatland site during baseflow (∼5 mg l-1). In contrast, at the larger scales, DOC was minimal during low flows (∼2 mg l-1) due to increased groundwater influence and the disconnection between DOC sources and the stream. High frequency data also revealed diel variability during low flows. Insights into event dynamics through the analysis of hysteresis loops showed slight dilution on the rising limb, the strong influence of dry antecedent conditions and a quick recovery between events at the riparian peatland site. Again, these dynamics are driven by the tight coupling and high connectivity of the landscape to the stream. At larger scales, the disconnection between the landscape units increases and the variable connectivity

Temporal-spatial variation of DOC concentration, UV absorbance and the flux estimation in the Lower Dagu River, China

NASA Astrophysics Data System (ADS)

Xi, Min; Kong, Fanlong; Li, Yue; Kong, Fanting

2017-12-01

Dissolved organic carbon (DOC) is an important component for both carbon cycle and energy balance. The concentration, UV absorbance, and export flux of DOC in the natural environment dominate many important transport processes. To better understand the temporal and spatial variation of DOC, 7 sites along the Lower Dagu River were chosen to conduct a comprehensive measurement from March 2013 to February 2014. Specifically, water samples were collected from the Lower Dagu River between the 26th and 29th of every month during the experimental period. The DOC concentration (CDOC) and UV absorbance were analyzed using a total organic carbon analyzer and the ultraviolet-visible absorption spectrum, and the DOC export flux was estimated with a simple empirical model. The results showed that the CDOC of the Lower Dagu River varied from 1.32 to 12.56 mg/L, consistent with global rivers. The CDOC and UV absorbance showed significant spatial variation in the Dagu River during the experiential period because of the upstream natural processes and human activities in the watershed. The spatial variation is mainly due to dam or reservoir constructions, riverside ecological environment changes, and non-point source or wastewater discharge. The seasonal variation of CDOC was mainly related to the source of water DOC, river runoff, and temperature, and the UV absorbance and humification degree of DOC had no obvious differences among months ( P<0.05). UV absorbance was applied to test the CDOC in Lower Dagu River using wave lengths of 254 and 280 nm. The results revealed that the annual DOC export flux varied from 1.6 to 3.76 × 105 g C/km2/yr in a complete hydrological year, significantly lower than the global average. It is worth mentioning that the DOC export flux was mainly concentrated in summer (˜90% of all-year flux in July and August), since the runoff in the Dagu River took place frequently in summer. These observations implied environment change could bring the temporal

A Hyporheic Mesocosm Experiment: Influence of Quantity and Quality of stream-source DOC on Rates of Hyporheic Metabolism

NASA Astrophysics Data System (ADS)

Serchan, S. P.; Wondzell, S. M.; Haggerty, R.; Pennington, R.; Feris, K. P.; Sanfilippo, A. R.; Reeder, W. J.; Tonina, D.

2016-12-01

Hyporheic zone biogeochemical processes can influence stream water chemistry. Some estimates show that 50-90% stream water CO2 is produced in the hyporheic zone through heterotrophic metabolism of organic matter, usually supplied from the stream as dissolved organic carbon (DOC). Preliminary results from our well network at the HJ Andrews WS1, indicate that dissolved inorganic carbon (DIC) is 1.5-2 times higher in the hyporheic zone than in stream water. Conversely, DOC (mg/L) is 1.5 times higher in stream water than in the hyporheic zone throughout the year. Overall, the hyporheic zone appears to be a net source of DIC. However, the increase in DIC along hyporheic flow paths is approximately 10-times greater than the loss of DOC, suggesting that metabolism of buried particulate organic carbon (POC) is a major source of organic carbon for microbial metabolism. However, we cannot completely rule out alternative sources of DIC, especially those originating in the overlying riparian soil, because hyporheic processes are difficult to isolate in well networks. To study hyporheic zone biogeochemical processes, particularly the transformation of organic carbon to inorganic carbon species, we designed and built six replicate 2-m long hyporheic mesocosms in which we are conducting DOC amendment experiments. We examine the role of DOC quality and quantity on hyporheic respiration by injecting labile (acetate) and refractory (fulvic acid) organic carbon and comparing rates of O2 consumption, DOC loss, and DIC gains against a control. We expect that stream source DOC is limiting in this small headwater stream, forcing hyporheic metabolism to rely on buried POC. However, the long burial time of POC suggests it is likely of low quality so that supplying labile DOC in stream water should shift hyporheic metabolism away from POC rather than increase the overall rate of metabolism. Future experiments will examine natural sources of DOC (stream periphyton, leaf, and soil humic

docBUILDER - Building Your Useful Metadata for Earth Science Data and Services.

NASA Astrophysics Data System (ADS)

Weir, H. M.; Pollack, J.; Olsen, L. M.; Major, G. R.

2005-12-01

The docBUILDER tool, created by NASA's Global Change Master Directory (GCMD), assists the scientific community in efficiently creating quality data and services metadata. Metadata authors are asked to complete five required fields to ensure enough information is provided for users to discover the data and related services they seek. After the metadata record is submitted to the GCMD, it is reviewed for semantic and syntactic consistency. Currently, two versions are available - a Web-based tool accessible with most browsers (docBUILDERweb) and a stand-alone desktop application (docBUILDERsolo). The Web version is available through the GCMD website, at http://gcmd.nasa.gov/User/authoring.html. This version has been updated and now offers: personalized templates to ease entering similar information for multiple data sets/services; automatic population of Data Center/Service Provider URLs based on the selected center/provider; three-color support to indicate required, recommended, and optional fields; an editable text window containing the XML record, to allow for quick editing; and improved overall performance and presentation. The docBUILDERsolo version offers the ability to create metadata records on a computer wherever you are. Except for installation and the occasional update of keywords, data/service providers are not required to have an Internet connection. This freedom will allow users with portable computers (Windows, Mac, and Linux) to create records in field campaigns, whether in Antarctica or the Australian Outback. This version also offers a spell-checker, in addition to all of the features found in the Web version.

Distinct expression of alkaline phosphatase activity in epilimnetic bacteria: Implication for persistent DOC consumption in a P-limited reservoir

NASA Astrophysics Data System (ADS)

Tseng, Y.; Kao, S.; Shiah, F.

2013-12-01

In a P-deficient system, P availability usually controls the microbial activity and thus the ecosystem function. Thingstad et al. (1997) first addressed a 'Malfunctioning Microbial-loop' theory, which stated that low bacterial production (BP) caused by insufficient nutrient supply would result in DOC accumulation in an oligotrophic ecosystem. In this study we re-examined the theory by conducting seasonal patterns and correlations among soluble reactive phosphate (SRP) and DOC, microbial abundances (picocyanobacteria, bacteria, and heterotrophic nanoflagellate; HNF) and activities (primary production, bacterial production, and alkaline phosphatase activity; APA) coupled with enzyme-labeled fluorescence (ELF) assays on bacterioplankton in a subtropical reservoir sharing the common features, nitrate-replete and P-deficient, with most natural freshwater system during Oct 2007-Oct 2008. Persistently high APA was recorded during most of time, implying that the system was P-deficient. Size fractionated APA and ELF assay revealed that bacteria were the major APA contributor. However, significantly low epilimnion DOC was recorded during the stratified summer season accompanying with high BP and APA as well as high PP, implying that heterotrophic bacteria can well sustain in P-deficient system by utilizing DOP to rapidly lower down DOC under relatively high PP. Such findings oppose the 'Malfunctioning Microbial-loop' theory. On the other hand, strong epilimnetic DOC accumulation occurred in Oct 2007 under low light and low PP condition accompanying with high abundance of HNF, implying that HNF grazing may contribute to a certain degree of DOC accumulation. Correlation matrix supported our suggestions. This study testified the DOC dynamics in P-deficient ecosystem are tightly coupled with the source (PP and grazing) and sink (BP). We also suggested that in SRP-limited freshwater systems bacteria are capable of breaking down autochthonous DOC to reduce the chance of DOC

Cross-regional prediction of long-term trajectory of stream water DOC response to climate change

Treesearch

H. Laudon; J.M. Buttle; S.K. Carey; J.J. McDonnell; K.J. McGuire; J. Seibert; J. Shanley; C. Soulsby; D. Tetzlaff

2012-01-01

There is no scientific consensus about how dissolved organic carbon (DOC) in surface waters is regulated. Here we combine recent literature data from 49 catchments with detailed stream and catchment process information from nine well established research catchments at mid- to high latitudes to examine the question of how climate controls stream water DOC. We show for...

Dynamics of dissolved organic carbon (DOC) through stormwater basins designed for groundwater recharge in urban area: Assessment of retention efficiency.

PubMed

Mermillod-Blondin, Florian; Simon, Laurent; Maazouzi, Chafik; Foulquier, Arnaud; Delolme, Cécile; Marmonier, Pierre

2015-09-15

Managed aquifer recharge (MAR) has been developed in many countries to limit the risk of urban flooding and compensate for reduced groundwater recharge in urban areas. The environmental performances of MAR systems like infiltration basins depend on the efficiency of soil and vadose zone to retain stormwater-derived contaminants. However, these performances need to be finely evaluated for stormwater-derived dissolved organic matter (DOM) that can affect groundwater quality. Therefore, this study examined the performance of MAR systems to process DOM during its transfer from infiltration basins to an urban aquifer. DOM characteristics (fluorescent spectroscopic properties, biodegradable and refractory fractions of dissolved organic carbon -DOC-, consumption by micro-organisms during incubation in slow filtration sediment columns) were measured in stormwater during its transfer through three infiltration basins during a stormwater event. DOC concentrations sharply decreased from surface to the aquifer for the three MAR sites. This pattern was largely due to the retention of biodegradable DOC which was more than 75% for the three MAR sites, whereas the retention of refractory DOC was more variable and globally less important (from 18% to 61% depending on MAR site). Slow filtration column experiments also showed that DOC retention during stormwater infiltration through soil and vadose zone was mainly due to aerobic microbial consumption of the biodegradable fraction of DOC. In parallel, measurements of DOM characteristics from groundwaters influenced or not by MAR demonstrated that stormwater infiltration increased DOC quantity without affecting its quality (% of biodegradable DOC and relative aromatic carbon content -estimated by SUVA254-). The present study demonstrated that processes occurring in soil and vadose zone of MAR sites were enough efficient to limit DOC fluxes to the aquifer. Nevertheless, the enrichments of DOC concentrations measured in groundwater below

Assessing Environmental Drivers of DOC Fluxes in the Shark River Estuary: Modeling the Effects of Climate, Hydrology and Water Management

NASA Astrophysics Data System (ADS)

Regier, P.; Briceno, H.; Jaffe, R.

2016-02-01

Urban and agricultural development of the South Florida peninsula has disrupted freshwater flow in the Everglades, a hydrologically connected ecosystem stretching from central Florida to the Gulf of Mexico. Current system-scale restoration efforts aim to restore natural hydrologic regimes to reestablish pre-drainage ecosystem functioning through increased water availability, quality and timing. However, it is uncertain how hydrologic restoration combined with climate change will affect the downstream section of the system, including the mangrove estuaries of Everglades National Park. Aquatic transport of carbon, primarily as dissolved organic carbon (DOC), plays a critical role in biogeochemical cycling and food-web dynamics, and will be affected both by water management policies and climate change. To better understand DOC dynamics in these estuaries and how hydrology, climate and water management may affect them, 14 years of monthly data collected in the Shark River estuary were used to build a DOC flux model. Multi-variate methods were applied to long-term data-sets for hydrology, water quality and climate to untangle the interconnected environmental drivers that control DOC export at intra and inter-annual scales. DOC fluxes were determined to be primarily controlled by hydrology but also by seasonality and long-term climate patterns. Next, a 4-component model (salinity, inflow, rainfall, Atlantic Multidecadal Oscillation) capable of predicting DOC fluxes (R2=0.78, p<0.0001, n=161) was established. Finally, potential climate change scenarios for the Everglades were applied to this model to assess DOC flux variations in response to climate and restoration variables. Although global predictions anticipate that DOC export will generally increase in the future, the majority of scenario runs indicated that DOC export from the Everglades is expected to decrease due to changes in rainfall, evapotranspiration, inflows and sea-level rise.

A 125 year long record of DOC flux from a major temperate catchment: land-use vs. climate control?

NASA Astrophysics Data System (ADS)

Clay, G.; Worrall, F.; Howden, N. K.; Burt, T. P.

2010-12-01

Our understanding of the controls upon carbon biogeochemistry has always been limited by lack of long term observational data at the same time as having long term monitoring of possible environmental drivers. For the River Thames catchment in the UK (9998 km2) records of DOM have been kept since 1868 and DOM flux since 1882. In addition to riverflow being monitored in the catchment there has also been monitoring of climate, land-use and population back to at least 1868. The Thames catchment is a mixed agricultural urban catchment dominated by mineral soils where groundwater plays a significant part in the catchments flow system. During the period of the record the catchment has undergone urbanisation, climate warming but has also undergone large-scale land use change associated with World War II and agricultural intensification in the 1960s. The importance of these combinations of pressures are explored in the time series through a range of time series techniques and the results show: i) That DOC flux in the catchment is now at historic low levels, with the maximum flux being 35 ktonnes C/yr (3.5 tonnes/km2/yr) in 1915 and the lowest flux being 2 ktonnes C/yr (0.2 tonnes/km2/yr) in 1997. ii) The trend in the DOC flux is explained by changes in flow, which appear associated with both with groundwater storage in the catchment and with changes in land-use. iii) The significant decline in the DOC flux appears to be due to the transition in the catchment from dominated from pasture to an arable land use. iv) The decline of DOC flux with temperature would suggest that DOC mineralisation reaction has a higher Q10 than the DOC production. v) Declining DOC flux from mineral soils catchments would offset increases in DOC flux from organic soils but would also represent a shift in carbon losses from fluvial to being direct to the atmosphere.

Influence of adsorption versus coprecipitation on the retention of rice straw-derived dissolved organic carbon and subsequent reducibility of Fe-DOC systems

NASA Astrophysics Data System (ADS)

Sodano, Marcella; Lerda, Cristina; Martin, Maria; Celi, Luisella; Said-Pullicino, Daniel

2016-04-01

The dissimilatory reduction of Fe oxides is the main organic C-consuming process in paddy soils under anoxic conditions. The contribution of Fe(III) reduction to anaerobic C mineralization depends on many factors, but most importantly on the bioavailability of labile organic matter and a reducible Fe pool as electron donors and acceptors, respectively. On the other hand, the strong affinity of these minerals for organic matter and their capability of protecting it against microbial decomposition is well known. Natural Fe oxides in these soils may therefore play a key role in determining the C source/sink functions of these agro-ecosystems. Apart from contributing to C stabilization, the interaction between Fe oxides and dissolved organic C (DOC) may influence the structure and reactivity of these natural oxides, and selectively influence the chemical properties of DOC. Indeed, Fe-DOC associations may not only reduce the availability of DOC, but may also limit the microbial reduction of Fe oxides under anoxic conditions. In fact, the accessibility of these minerals to microorganisms, extracellular enzymes, redox active shuttling compound or reducing agents may be impeded by the presence of sorbed organic matter. In soils that are regularly subjected to fluctuations in redox conditions the interaction between DOC and Fe oxides may not only involve organic coatings on mineral surfaces, but also Fe-DOC coprecipitates that form during the rapid oxidation of soil solutions containing important amounts of DOC and Fe(II). However, little is known on how these processes influence DOC retention, and the structure and subsequent reducibility of these Fe-DOC associations. We hypothesized that the nature and extent of the interaction between DOC and Fe oxides may influence the accessibility of the bioavailable Fe pool and consequently its reducibility. We tested this hypothesis by synthesizing a series of Fe-DOC systems with increasing C:Fe ratios prepared by either surface

Direct quantitative detection of Doc2b-induced hemifusion in optically trapped membranes

NASA Astrophysics Data System (ADS)

Brouwer, Ineke; Giniatullina, Asiya; Laurens, Niels; van Weering, Jan R. T.; Bald, Dirk; Wuite, Gijs J. L.; Groffen, Alexander J.

2015-09-01

Ca2+-sensor proteins control the secretion of many neuroendocrine substances. Calcium-secretion coupling may involve several mechanisms. First, Ca2+-dependent association of their tandem C2 domains with phosphatidylserine may induce membrane curvature and thereby enhance fusion. Second, their association with SNARE complexes may inhibit membrane fusion in the absence of a Ca2+ trigger. Here we present a method using two optically trapped beads coated with SNARE-free synthetic membranes to elucidate the direct role of the C2AB domain of the soluble Ca2+-sensor Doc2b. Contacting membranes are often coupled by a Doc2b-coated membrane stalk that resists forces up to 600 pN upon bead separation. Stalk formation depends strictly on Ca2+ and phosphatidylserine. Real-time fluorescence imaging shows phospholipid but not content mixing, indicating membrane hemifusion. Thus, Doc2b acts directly on membranes and stabilizes the hemifusion intermediate in this cell-free system. In living cells, this mechanism may co-occur with progressive SNARE complex assembly, together defining Ca2+-secretion coupling.

Speciation of Se and DOC in soil solution and their relation to Se bioavailability.

PubMed

Weng, Liping; Vega, Flora Alonso; Supriatin, Supriatin; Bussink, Wim; Van Riemsdijk, Willem H

2011-01-01

A 0.01 M CaCl(2) extraction is often used to asses the bioavailability of plant nutrients in soils. However, almost no correlation was found between selenium (Se) in the soil extraction and Se content in grass. The recently developed anion Donnan membrane technique was used to analyze chemical speciation of Se in the 0.01 M CaCl(2) extractions of grassland soils and fractionation of DOC (dissolved organic carbon). The results show that most of Se (67-86%) in the extractions (15 samples) are colloidal-sized Se. Only 13-34% of extractable Se are selenate, selenite and small organic Se (<1 nm). Colloidal Se is, most likely, Se bound to or incorporated in colloidal-sized organic matter. The dominant form of small Se compounds (selenate, selenite/small organic compounds) depends on soil. A total of 47-85% of DOC is colloidal-sized and 15-53% are small organic molecules (<1 nm). In combination with soluble S (sulfur) and/or P (phosphor), concentration of small DOC can explain most of the variability of Se content in grass. The results indicate that mineralization of organic Se is the most important factor that controls Se availability in soils. Competition with sulfate and phosphate needs to be taken into account. Further research is needed to verify if concentration of small DOC is a good indicator of mineralization of soil organic matter.

Adsorption and bioadsorption of granular activated carbon (GAC) for dissolved organic carbon (DOC) removal in wastewater.

PubMed

Xing, W; Ngo, H H; Kim, S H; Guo, W S; Hagare, P

2008-12-01

In this study, the performances of GAC adsorption and GAC bioadsorption in terms of dissolved organic carbon (DOC) removal were investigated with synthetic biologically treated sewage effluent (BTSE), synthetic primary treated sewage effluent (PTSE), real BTSE and real PTSE. The main aims of this study are to verify and compare the efficiency of DOC removal by GAC (adsorption) and acclimatized GAC (bioadsorption). The results indicated that the performance of bioadsorption was significantly better than that of adsorption in all cases, showing the practical use of biological granular activated carbon (BGAC) in filtration process. The most significance was observed at a real PTSE with a GAC dose of 5g/L, having 54% and 96% of DOC removal by adsorption and bioadsorption, respectively. In addition, it was found that GAC adsorption equilibrium was successfully predicted by a hybrid Langmuir-Freundlich model whilst integrated linear driving force approximation (LDFA)+hybrid isotherm model could describe well the adsorption kinetics. Both adsorption isotherm and kinetic coefficients determined by these models will be useful to model the adsorption/bioadsorption process in DOC removal of BGAC filtration system.

Using Project-Based Learning and Google Docs to Support Diversity

ERIC Educational Resources Information Center

Leh, Amy

2014-01-01

A graduate course, ETEC543 ("Technology and Learning I"), was revised to better serve increasing new student population, international students, in an academic program. Project-based learning, Google Docs, and instructional strategies fostering diversity and critical thinking were incorporated into the course redesign. Observations,…

Regulation of stream water dissolved organic carbon concentrations ([DOC]) during snowmelt in forest streams; the role of discharge, winter climate and memory effects

NASA Astrophysics Data System (ADS)

Ågren, A.; Haei, M.; Öquist, M.; Buffam, I.; Ottosson-Löfvenius, M.; Kohler, S.; Bishop, K.; Blomkvist, P.; Laudon, H.

2011-12-01

Using 15 year stream records from two forested northern boreal catchments, coupled with soil frost experiments in the riparian zone, we demonstrate the complex inter-annual control on [DOC] and export during snowmelt. Stream [DOC] varied by a factor of 2 during those 15 years with no consistent trend. Based on our long-term analysis, we demonstrate, for the first time, that stream water [DOC] is strongly linked to the climatic conditions during the preceding winter, but that there is also a long-term memory effect in the catchment soils, related to the extent of the previous export from the catchment. Hydrology had a first order control on the inter-annual variation in concentrations, and the length of the winter was more important than the memory effect. By removing the effect of discharge on [DOC], using a conceptual hydrological model, we could detect processes that would otherwise have been overshadowed. A short and intense snowmelt gave higher [DOC] in the stream. During a prolonged snowmelt, one soil layer at the time might have been "flushed" from easily exported DOC, resulting in slightly lower stream [DOC] during such years. We found that longer and colder winters resulted in higher [DOC] during the subsequent snowmelt. A soil frost manipulation experiment in the riparian soils of the study catchment showed that the DOC concentrations in the soil water increased with the duration of the soil frost. A high antecedent DOC export during the preceding summer and autumn resulted in lower concentrations during the following spring, indicating a long-term "memory effect" of the catchment soils. In a nearby stream draining mire, we found a different response to hydrology but similar response to climate and memory effect. The inter-annual variation in snowmelt DOC exports was mostly controlled by the amount of runoff, but the variability in [DOC] also exerted a significant control on the exports, accounting for 15% of the variance in exports. We conclude that

Deconstructing the Effects of Flow on DOC, Nitrate, and Major Ion Interactions Using a High-Frequency Aquatic Sensor Network

NASA Astrophysics Data System (ADS)

Koenig, L. E.; Shattuck, M. D.; Snyder, L. E.; Potter, J. D.; McDowell, W. H.

2017-12-01

Streams provide a physical linkage between land and downstream river networks, delivering solutes derived from multiple catchment sources. We analyzed high-frequency time series of stream solutes to characterize the timing and magnitude of major ion, nutrient, and organic matter transport over event, seasonal, and annual timescales as well as to assess whether nitrate (NO3-) and dissolved organic carbon (DOC) transport are coupled in catchments, which would be expected if they are subject to similar biogeochemical controls throughout the watershed. Our data set includes in situ observations of NO3-, fluorescent dissolved organic matter (DOC proxy), and specific conductance spanning 2-4 years in 10 streams and rivers across New Hampshire, including observations of nearly 700 individual hydrologic events. We found a positive response of NO3- and DOC to flow in forested streams, but watershed development led to a negative relationship between NO3- and discharge, and thus a decoupling of the overall NO3- and DOC responses to flow. On event and seasonal timescales, NO3- and DOC consistently displayed different behaviors. For example, in several streams, FDOM yield was greatest during summer storms while NO3- yield was greatest during winter storms. Most streams had generalizable storm NO3- and DOC responses, but differences in the timing of NO3- and DOC transport suggest different catchment sources. Further, certain events, including rain-on-snow and summer storms following dry antecedent conditions, yielded disproportionate NO3- responses. High-frequency data allow for increased understanding of the processes controlling solute variability and will help reveal their responses to changing climatic regimes.

Oxygen dynamics in a boreal lake responds to long-term changes in climate, ice phenology, and DOC inputs

NASA Astrophysics Data System (ADS)

Couture, Raoul-Marie; de Wit, Heleen A.; Tominaga, Koji; Kiuru, Petri; Markelov, Igor

2015-11-01

Boreal lakes are impacted by climate change, reduced acid deposition, and changing loads of dissolved organic carbon (DOC) from catchments. We explored, using the process-based lake model MyLake, how changes in these pressures modulate ice phenology and the dissolved oxygen concentrations (DO) of a small boreal humic lake. The model was parametrized against year-round time series of water temperature and DO from a lake buoy. Observed trends in air temperature (+0.045°C yr-1) and DOC concentration (0.11 mg C L-1 yr-1, +1% annually) over the past 40 years were used as model forcings. A backcast of ice freezing and breakup dates revealed that ice breakup occurred on average 8 days earlier in 2014 than in 1974. The earlier ice breakup enhanced water column ventilation resulting in higher DO in the spring. Warmer water in late summer led to longer anoxic periods, as microbial DOC turnover increased. A long-term increase in DOC concentrations caused a decline in lake DO, leading to 15% more hypoxic days (<3 mg L-1) and 10% more anoxic days (<15 µg L-1) in 2014 than in 1974. We conclude that climate warming and increasing DOC loads are antagonistic with respect to their effect on DO availability. The model suggests that DOC is a stronger driver of DO consumption than temperature. The browning of lakes may thus cause reductions in the oxythermal habitat of fish and aquatic biota in boreal lakes.

What is a Post-Doc

NASA Astrophysics Data System (ADS)

Baha Balantekin, A.

2006-04-01

It is commonplace for physics Ph.D.'s spend a number of years at universities, government laboratories, and research institutes as postdoctoral associates before they assume permanent positions. In this talk the expectations and the responsibilities of this career stage will be explored from both the young scientists' and employer's perspectives.

Direct DOC and nitrate determination in water using dual pathlength and second derivative UV spectrophotometry.

PubMed

Causse, Jean; Thomas, Olivier; Jung, Aude-Valérie; Thomas, Marie-Florence

2017-01-01

UV spectrophotometry is largely used for water and wastewater quality monitoring. The measurement/estimation of specific and aggregate parameters such as nitrate and dissolved organic carbon (DOC) is possible with UV spectra exploitation, from 2 to multi wavelengths calibration. However, if nitrate determination from UV absorbance is known, major optical interferences linked to the presence of suspended solids, colloids or dissolved organic matter limit the relevance of UV measurement for DOC assessment. A new method based on UV spectrophotometric measurement of raw samples (without filtration) coupling a dual pathlength for spectra acquisition and the second derivative exploitation of the signal is proposed in this work. The determination of nitrate concentration is carried out from the second derivative of the absorbance at 226 nm corresponding at the inflexion point of nitrate signal decrease. A short optical pathlength can be used considering the strong absorption of nitrate ion around 210 nm. For DOC concentration determination the second derivative absorbance at 295 nm is proposed after nitrate correction. Organic matter absorbing slightly in the 270-330 nm window, a long optical pathlength must be selected in order to increase the sensitivity. The method was tested on several hundred of samples from small rivers of two agricultural watersheds located in Brittany, France, taken during dry and wet periods. The comparison between the proposed method and the standardised procedures for nitrate and DOC measurement gave a good adjustment for both parameters for ranges of 2-100 mg/L NO3 and 1-30 mg/L DOC. Copyright © 2016 Elsevier Ltd. All rights reserved.

Abundance, stable isotopic composition, and export fluxes of DOC, POC, and DIC from the Lower Mississippi River during 2006–2008

USGS Publications Warehouse

Cai, Yihua; Guo, Laodong; Wang, Xuri; Aiken, George R.

2015-01-01

Sources, abundance, isotopic compositions, and export fluxes of dissolved inorganic carbon (DIC), dissolved and colloidal organic carbon (DOC and COC), and particulate organic carbon (POC), and their response to hydrologic regimes were examined through monthly sampling from the Lower Mississippi River during 2006–2008. DIC was the most abundant carbon species, followed by POC and DOC. Concentration and δ13C of DIC decreased with increasing river discharge, while those of DOC remained fairly stable. COC comprised 61 ± 3% of the bulk DOC with similar δ13C abundances but higher percentages of hydrophobic organic acids than DOC, suggesting its aromatic and diagenetically younger status. POC showed peak concentrations during medium flooding events and at the rising limb of large flooding events. While δ13C-POC increased, δ15N of particulate nitrogen decreased with increasing discharge. Overall, the differences in δ13C between DOC or DIC and POC show an inverse correlation with river discharge. The higher input of soil organic matter and respired CO2 during wet seasons was likely the main driver for the convergence of δ13C between DIC and DOC or POC, whereas enhanced in situ primary production and respiration during dry seasons might be responsible for their isotopic divergence. Carbon export fluxes from the Mississippi River were estimated to be 13.6 Tg C yr−1 for DIC, 1.88 Tg C yr−1 for DOC, and 2.30 Tg C yr−1 for POC during 2006–2008. The discharge-normalized DIC yield decreased during wet seasons, while those of POC and DOC increased and remained constant, respectively, implying variable responses in carbon export to the increasing discharge.

The first insight into the metabolite profiling of grapes from three Vitis vinifera L. cultivars of two controlled appellation (DOC) regions.

PubMed

Teixeira, António; Martins, Viviana; Noronha, Henrique; Eiras-Dias, José; Gerós, Hernâni

2014-03-10

The characterization of the metabolites accumulated in the grapes of specific cultivars grown in different climates is of particular importance for viticulturists and enologists. In the present study, the metabolite profiling of grapes from the cultivars, Alvarinho, Arinto and Padeiro de Basto, of two Portuguese Controlled Denomination of Origin (DOC) regions (Vinho Verde and Lisboa) was investigated by gas chromatography-coupled time-of-flight mass spectrometry (GC-TOF-MS) and an amino acid analyzer. Primary metabolites, including sugars, organic acids and amino acids, and some secondary metabolites were identified. Tartaric and malic acids and free amino acids accumulated more in grapes from vines of the DOC region of Vinho Verde than DOC Lisboa, but a principal component analysis (PCA) plot showed that besides the DOC region, the grape cultivar also accounted for the variance in the relative abundance of metabolites. Grapes from the cultivar, Alvarinho, were particularly rich in malic acid and tartaric acids in both DOC regions, but sucrose accumulated more in the DOC region of Vinho Verde.

The First Insight into the Metabolite Profiling of Grapes from Three Vitis vinifera L. Cultivars of Two Controlled Appellation (DOC) Regions

PubMed Central

Teixeira, António; Martins, Viviana; Noronha, Henrique; Eiras-Dias, José; Gerós, Hernâni

2014-01-01

The characterization of the metabolites accumulated in the grapes of specific cultivars grown in different climates is of particular importance for viticulturists and enologists. In the present study, the metabolite profiling of grapes from the cultivars, Alvarinho, Arinto and Padeiro de Basto, of two Portuguese Controlled Denomination of Origin (DOC) regions (Vinho Verde and Lisboa) was investigated by gas chromatography-coupled time-of-flight mass spectrometry (GC-TOF-MS) and an amino acid analyzer. Primary metabolites, including sugars, organic acids and amino acids, and some secondary metabolites were identified. Tartaric and malic acids and free amino acids accumulated more in grapes from vines of the DOC region of Vinho Verde than DOC Lisboa, but a principal component analysis (PCA) plot showed that besides the DOC region, the grape cultivar also accounted for the variance in the relative abundance of metabolites. Grapes from the cultivar, Alvarinho, were particularly rich in malic acid and tartaric acids in both DOC regions, but sucrose accumulated more in the DOC region of Vinho Verde. PMID:24619195

Mapping Surface Water DOC in the Northern Gulf of Mexico Using CDOM Absorption Coefficients and Remote Sensing Imagery

NASA Astrophysics Data System (ADS)

Kelly, B.; Chelsky, A.; Bulygina, E.; Roberts, B. J.

2017-12-01

Remote sensing techniques have become valuable tools to researchers, providing the capability to measure and visualize important parameters without the need for time or resource intensive sampling trips. Relationships between dissolved organic carbon (DOC), colored dissolved organic matter (CDOM) and spectral data have been used to remotely sense DOC concentrations in riverine systems, however, this approach has not been applied to the northern Gulf of Mexico (GoM) and needs to be tested to determine how accurate these relationships are in riverine-dominated shelf systems. In April, July, and October 2017 we sampled surface water from 80+ sites over an area of 100,000 km2 along the Louisiana-Texas shelf in the northern GoM. DOC concentrations were measured on filtered water samples using a Shimadzu TOC-VCSH analyzer using standard techniques. Additionally, DOC concentrations were estimated from CDOM absorption coefficients of filtered water samples on a UV-Vis spectrophotometer using a modification of the methods of Fichot and Benner (2011). These values were regressed against Landsat visible band spectral data for those same locations to establish a relationship between the spectral data, CDOM absorption coefficients. This allowed us to spatially map CDOM absorption coefficients in the Gulf of Mexico using the Landsat spectral data in GIS. We then used a multiple linear regressions model to derive DOC concentrations from the CDOM absorption coefficients and applied those to our map. This study provides an evaluation of the viability of scaling up CDOM absorption coefficient and remote-sensing derived estimates of DOC concentrations to the scale of the LA-TX shelf ecosystem.

TOC/DOC: "It Has Changed the Way I Do Science".

ERIC Educational Resources Information Center

Douglas, Kimberly; Roth, Dana L.

1997-01-01

Describes a user-based automated service developed at the California Institute of Technology that combines access to journal article databases with an in-house document delivery system. TOC/DOC (Tables of Contents/Document Delivery) has undergone a conceptual change from a catalog of locally-held journal articles to a broader, more retrospective…

Experimental study on the particulate matter and nitrogenous compounds from diesel engine retrofitted with DOC+CDPF+SCR

NASA Astrophysics Data System (ADS)

Zhang, Yunhua; Lou, Diming; Tan, Piqiang; Hu, Zhiyuan

2018-03-01

The increasingly stringent emission regulations will mandate the retrofit of after-treatment devices for in-use diesel vehicles, in order to reduce their substantial particulate matter and nitrogen oxides (NOX) emissions. In this paper, a combination of DOC (diesel oxidation catalyst), CDPF (catalytic diesel particulate filter) and SCR (selective catalytic reduction) retrofit for a heavy-duty diesel engine was employed to perform experiment on the engine test bench to evaluate the effects on the particulate matter emissions including particle number (PN), particle mass (PM), particle size distributions and nitrogenous compounds emissions including NOX, nitrogen dioxide (NO2)/NOX, nitrous oxide (N2O) and ammonia (NH3) slip. In addition, the urea injection was also of our concern. The results showed that the DOC+CDPF+SCR retrofit almost had no adverse effect on the engine power and fuel consumption. Under the test loads, the upstream DOC and CDPF reduced the PN and PM by an average of 91.6% and 90.9%, respectively. While the downstream SCR brought about an average decrease of 85% NOX. Both PM and NOX emission factors based on this retrofit were lower than China-Ⅳ limits (ESC), and even lower than China-Ⅴ limits (ESC) at medium and high loads. The DOC and CDPF changed the particle size distributions, leading to the increase in the proportion of accumulation mode particles and the decrease in the percentage of nuclear mode particles. This indicates that the effect of DOC and CDPF on nuclear mode particles was better than that of accumulation mode ones. The upstream DOC could increase the NO2/NOX ratio to 40%, higher NO2/NOX ratio improved the efficiency of CDPF and SCR. Besides, the N2O emission increased by an average of 2.58 times after the retrofit and NH3 slip occurred with the average of 26.7 ppm. The rate of urea injection was roughly equal to 8% of the fuel consumption rate. The DOC+CDPF+SCR retrofit was proved a feasible and effective measurement in terms

Linking major and trace element headwater stream concentrations to DOC release and hydrologic conditions in a bog and peaty riparian zone

NASA Astrophysics Data System (ADS)

Broder, Tanja; Biester, Harald

2017-04-01

Peatlands and organic-rich riparian zones are known to export large amounts of dissolved organic carbon (DOC) to surface water. In organic-rich, acidic headwater streams main carriers for element export are dissolved organic matter (DOM) and organic-iron complexes. In this environment DOM might also act as major carrier for metals, which otherwise may have a low solubility. This study examines annual and short term event-based variations of major and trace elements in a headwater catchment. Patterns are used to trace hydrological pathways and element sources under different hydrologic preconditions. Furthermore, it elucidates the importance of DOC as carrier of different elements in a bog and a peaty riparian catchment. The study was conducted in a small headwater stream draining an ombrotrophic peatland with an adjacent forested area with peaty riparian soils in the Harz Mountains (Germany). Discharge sampling was conducted weekly at two sites from snowmelt to begin of snowfall and in high resolution during selected discharge events in 2013 and 2014. Element concentrations were measured by means of ICP-MS and ICP-OES. A PCA was performed for each site and for annual and event datasets. Results show that a large number of element concentrations strongly correlate with DOC concentrations at the bog site. Even elements like Ca and Mg, which are known to have a low affinity to DOC. Congruently, the first principal component integrates the DOC pattern (element loadings > 0.8: Ca, Fe, Mg, Mn, Zn, As, Sr, Cd, DOC) and explained about 35 % of total variance and even 50 % during rain events (loadings > 0.8: Al, Ca, Fe, Mg, Mn, Zn, Li, Co, As, Sr, Cd, Pb, DOC). The study cannot verify that all correlating elements bind to DOC. It is likely that also a common mobilization pattern in the upper peat layer by plant decomposition causes the same response to changes in hydrologic pathways. Additionally, a low mineral content and an enrichment of elements like Fe and Mn in the

Viscosity changes of riparian water controls diurnal fluctuations of stream-flow and DOC concentration

NASA Astrophysics Data System (ADS)

Schwab, Michael; Klaus, Julian; Pfister, Laurent; Weiler, Markus

2015-04-01

Diurnal fluctuations in stream-flow are commonly explained as being triggered by the daily evapotranspiration cycle in the riparian zone, leading to stream flow minima in the afternoon. While this trigger effect must necessarily be constrained by the extent of the growing season of vegetation, we here show evidence of daily stream flow maxima in the afternoon in a small headwater stream during the dormant season. We hypothesize that the afternoon maxima in stream flow are induced by viscosity changes of riparian water that is caused by diurnal temperature variations of the near surface groundwater in the riparian zone. The patterns were observed in the Weierbach headwater catchment in Luxembourg. The catchment is covering an area of 0.45 km2, is entirely covered by forest and is dominated by a schistous substratum. DOC concentration at the outlet of the catchment was measured with the field deployable UV-Vis spectrometer spectro::lyser (scan Messtechnik GmbH) with a high frequency of 15 minutes over several months. Discharge was measured with an ISCO 4120 Flow Logger. During the growing season, stream flow shows a frequently observed diurnal pattern with discharge minima in the afternoon. During the dormant season, a long dry period with daily air temperature amplitudes of around 10 ° C occurred in March and April 2014, with discharge maxima in the afternoon. The daily air temperature amplitude led to diurnal variations in the water temperature of the upper 10 cm of the riparian zone. Higher riparian water temperatures cause a decrease in water viscosity and according to the Hagen-Poiseuille equation, the volumetric flow rate is inversely proportional to viscosity. Based on the Hagen-Poiseuille equation and the viscosity changes of water, we calculated higher flow rates of near surface groundwater through the riparian zone into the stream in the afternoon which explains the stream flow maxima in the afternoon. With the start of the growing season, the viscosity

Post-doctoral research fellowship as a health policy and systems research capacity development intervention: a case of the CHESAI initiative.

PubMed

Lembani, Martina; Teddy, Gina; Molosiwa, Dintle; Hwabamungu, Boroto

2016-12-20

Building capacity in health policy and systems research (HPSR), especially in low- and middle-income countries, remains a challenge. Various approaches have been suggested and implemented by scholars and institutions using various forms of capacity building to address challenges regarding HPSR development. The Collaboration for Health Systems Analysis and Innovation (CHESAI) - a collaborative effort between the Universities of Cape Town and the Western Cape Schools of Public Health - has employed a non-research based post-doctoral research fellowship (PDRF) as a way of building African capacity in the field of HPSR by recruiting four post-docs. In this paper, we (the four post-docs) explore whether a PDRF is a useful approach for capacity building for the field of HPSR using our CHESAI PDRF experiences. We used personal reflections of our written narratives providing detailed information regarding our engagement with CHESAI. The narratives were based on a question guide around our experiences through various activities and their impacts on our professional development. The data analysis process was highly iterative in nature, involving repeated meetings among the four post-docs to reflect, discuss and create themes that evolved from the discussions. The CHESAI PDRF provided multiple spaces for our engagement and capacity development in the field of HPSR. These spaces provided us with a wide range of learning experiences, including teaching and research, policy networking, skills for academic writing, engaging practitioners, co-production and community dialogue. Our reflections suggest that institutions providing PDRF such as this are valuable if they provide environments endowed with adequate resources, good leadership and spaces for innovation. Further, the PDRFs need to be grounded in a community of HPSR practice, and provide opportunities for the post-docs to gain an in-depth understanding of the broader theoretical and methodological underpinnings of the field

DOC II 32-bit digital optical computer: optoelectronic hardware and software

NASA Astrophysics Data System (ADS)

Stone, Richard V.; Zeise, Frederick F.; Guilfoyle, Peter S.

1991-12-01

This paper describes current electronic hardware subsystems and software code which support OptiComp's 32-bit general purpose digital optical computer (DOC II). The reader is referred to earlier papers presented in this section for a thorough discussion of theory and application regarding DOC II. The primary optoelectronic subsystems include the drive electronics for the multichannel acousto-optic modulators, the avalanche photodiode amplifier, as well as threshold circuitry, and the memory subsystems. This device utilizes a single optical Boolean vector matrix multiplier and its VME based host controller interface in performing various higher level primitives. OptiComp Corporation wishes to acknowledge the financial support of the Office of Naval Research, the National Aeronautics and Space Administration, the Rome Air Development Center, and the Strategic Defense Initiative Office for the funding of this program under contracts N00014-87-C-0077, N00014-89-C-0266 and N00014-89-C- 0225.

Rising susceptibility of freshwater DOC inputs to extreme events? The implications of underlying changes in atmospheric deposition and land-management. (Invited)

NASA Astrophysics Data System (ADS)

Evans, C.; Monteith, D.; Jones, T.; Burden, A.; Peacock, M.; Gauci, V.; Page, S. E.; Moore, S.

2013-12-01

Dissolved organic carbon (DOC) represents a significant loss term within the carbon (C) balance of many terrestrial ecosystems, and a quantitatively important and reactive C input to many freshwater ecosystems. DOC concentrations have risen dramatically, over a period of decades, in rivers and lakes draining semi-natural catchments across large areas of Northern Europe and Northeast North America, with wide-ranging consequences for C cycling, aquatic ecosystem functioning and drinking water treatment. These increases have been variously attributed to climatic changes, including increased incidence of extreme events, as well as land-management factors and changes in atmospheric deposition. A growing body of evidence now indicates that the primary driver of rising DOC has been ecosystem recovery from the historic effects of acid deposition, and thus that observed increases - whilst sometimes economically problematic - may represent a return to pre-industrial baseline conditions. In light of the apparent dominance of acidity change as a driver of recent freshwater DOC increases, we consider whether or not other potential drivers of change, including climatic extremes and management-related disturbances, are likely to exert a significant influence on the transport of DOC from catchments to surface waters. We conclude that the alleviation of acidification pressures has now made catchments in regions formerly impacted by sulphur pollution much more susceptible to extreme events and disturbances. Drawing on monitoring and experimental case studies from the UK, we suggest that DOC export from organic soils may be shifting from ';solubility controlled' to ';supply controlled', and that climatic events leading to enhanced DOC production (e.g. high temperatures or drought-rewet cycles) and/or shallow lateral transport (e.g. high flow events) are now generating freshwater DOC peaks that are unprecedented in the monitoring record. We also examine the role of land-management as

Carbon isotopes in peat, DOC, CO2, and CH4 in a Holocene peatland on Dartmoor, southwest England

NASA Astrophysics Data System (ADS)

Charman, Dan J.; Aravena, Ramon; Bryant, Charlotte L.; Harkness, Doug D.

1999-06-01

Carbon gases with younger 14C ages than those of the surrounding peat have been reported from continental boreal peatlands, a fact which suggests that significant movement of CO2, CH4, or DOC (dissolved organic carbon) and export of C via subsurface processes are not accounted for in most estimates of contributions to the C cycle. This paper tests the hypothesis that similar processes can occur in oceanic ombrotrophic mires where water and gas movement is theoretically minimal. Measurements of 14C and δ13C in CO2, CH4, and DOC, and of tritium, are reported from depths to 250 cm at Tor Royal, a raised mire in southwest England. Radiocarbon ages of gases are 1460 to 500 yr younger than those of peat from the same depths, and CO2 is consistently younger than CH4. DOC is 1260 to 830 yr younger than the peat, and significant amounts of tritium were found at all depths. Gas ages are mostly intermediate between the age of the peat and that of the DOC, which suggests that C is principally transported as DOC. However, some gases are younger than their associated DOC, which implies that movement of dissolved gases may also take place. δ13C values in gases suggest that CO2 reduction is the major pathway for CH4 production. Transport of C in deep peats is likely to be a significant component in the overall C budget of ombrotrophic oceanic peatlands, and C export via discharge to ground or surface waters may be an important mechanism for gaseous C emissions.

Biochar feedstock and pyrolysis temperature effects on leachate: DOC characteristics and nitrate losses from a Brazilian Cerrado Arenosol mixed with agricultural waste biochars.

PubMed

Speratti, Alicia B; Johnson, Mark S; Sousa, Heiriane Martins; Dalmagro, Higo J; Couto, Eduardo Guimarães

2018-04-01

Dissolved organic carbon (DOC) leached from Brazilian Cerrado Arenosols can lead to carbon (C) losses and lower soil fertility, while excessive nutrient, e.g. nitrate (NO 3 - ), leaching can potentially cause water contamination. As biochar has been shown to stabilize C and retain soil nutrients, a greenhouse experiment was conducted to test different biochars' contributions to DOC and NO 3 - leaching from a sandy soil. Biochars were made from four local agricultural waste feedstocks (cotton residue, swine manure, eucalyptus sawmill residue, sugarcane filtercake) pyrolysed at 400, 500 and 600 °C. Biochar was mixed with soil at 5% weight in pots and maize seeds planted. Leachate was collected weekly for six weeks and analyzed for DOC and NO 3 - concentrations, while fluorescence spectroscopy with parallel factor analysis (PARAFAC) was used to interpret DOC characteristics. Cotton and swine manure biochar treatments had higher DOC and NO 3 - losses than eucalyptus biochar, filtercake biochar, and control treatments. Cotton and swine manure biochar treatments at high temperatures lost mostly terrestrial, humified DOC, while swine manure, filtercake, and eucalyptus biochars at low temperatures lost mostly labile, microbially-derived DOC. Through the practical use of fluorescence spectroscopy, our study identified filtercake and eucalyptus biochars as most promising for retaining DOC and NO 3 - in a Cerrado Arenosol, potentially reducing stable C and nutrient losses. Copyright © 2018 Elsevier Ltd. All rights reserved.

Collaborative Lab Reports with Google Docs

NASA Astrophysics Data System (ADS)

Wood, Michael

2011-03-01

Science is a collaborative endeavor. The solitary genius working on the next great scientific breakthrough is a myth not seen much today. Instead, most physicists have worked in a group at one point in their careers, whether as a graduate student, faculty member, staff scientist, or industrial researcher. As an experimental nuclear physicist with research at the Thomas Jefferson National Accelerator Facility, my collaboration consists of over 200 scientists, both national and international. A typical experiment will have a dozen or so principal investigators. Add in the hundreds of staff scientists, engineers, and technicians, and it is clear that science is truly a collaborative effort. This paper will describe the use of Google Docs for collaborative reports for an introductory physics laboratory.

Understanding the relationship between DOC and nitrate export and dominant rainfall-runoff processes through long-term high frequency measurements

NASA Astrophysics Data System (ADS)

Schwab, Michael; Klaus, Julian; Pfister, Laurent; Weiler, Markus

2016-04-01

Over the past decades, stream sampling protocols for hydro-geochemical parameters were often limited by logistical and technological constraints. While long-term monitoring protocols were typically based on weekly sampling intervals, high frequency sampling was commonly limited to a few single events. In our study, we combined high frequency and long-term measurements to understand the DOC and nitrate behaviour and dynamics for different runoff events and seasons. Our study area is the forested Weierbach catchment (0.47 km2) in Luxembourg. The fractured schist bedrock is covered by cambisol soils. The runoff response of the catchment is characterized by a double peak behaviour. A first discharge peak occurs during or right after a rainfall event (triggered by fast near surface runoff generation processes), while a second delayed peak lasts several days (generated by subsurface flow/ shallow groundwater flow). Peaks in DOC concentrations are closely linked to the first discharge peak, whereas nitrate concentrations follow the second peak. Our observations were carried out with the field deployable instrument spectro::lyser (scan Messtechnik GmbH). This instrument relies on the principles of UV-Vis spectrometry and measures DOC and nitrate concentrations. The measurements were carried out at a high frequency of 15 minutes in situ in the Weierbach creek for more than two years. In addition, a long-term validation was carried out with data obtained from the analysis of water collected with automatic samplers. The long-term, high-frequency measurements allowed us to calculate a complete and detailed balance of DOC and nitrate export over two years. Transport behaviour of the DOC and nitrate showed different dynamics between the first and second hydrograph peaks. DOC is mainly exported during first peaks, while nitrate is mostly exported during the delayed second peaks. In combination with other measurements in the catchment, the long and detailed observations have

Rapid Response of Hydrological Loss of DOC to Water Table Drawdown and Warming in Zoige Peatland: Results from a Mesocosm Experiment

PubMed Central

Lou, Xue-Dong; Zhai, Sheng-Qiang; Kang, Bing; Hu, Ya-Lin; Hu, Li-Le

2014-01-01

A large portion of the global carbon pool is stored in peatlands, which are sensitive to a changing environment conditions. The hydrological loss of dissolved organic carbon (DOC) is believed to play a key role in determining the carbon balance in peatlands. Zoige peatland, the largest peat store in China, is experiencing climatic warming and drying as well as experiencing severe artificial drainage. Using a fully crossed factorial design, we experimentally manipulated temperature and controlled the water tables in large mesocosms containing intact peat monoliths. Specifically, we determined the impact of warming and water table position on the hydrological loss of DOC, the exported amounts, concentrations and qualities of DOC, and the discharge volume in Zoige peatland. Our results revealed that of the water table position had a greater impact on DOC export than the warming treatment, which showed no interactive effects with the water table treatment. Both DOC concentration and discharge volume were significantly increased when water table drawdown, while only the DOC concentration was significantly promoted by warming treatment. Annual DOC export was increased by 69% and 102% when the water table, controlled at 0 cm, was experimentally lowered by −10 cm and −20 cm. Increases in colored and aromatic constituents of DOC (measured by Abs254 nm, SUVA254 nm, Abs400 nm, and SUVA400 nm) were observed under the lower water tables and at the higher peat temperature. Our results provide an indication of the potential impacts of climatic change and anthropogenic drainage on the carbon cycle and/or water storage in a peatland and simultaneously imply the likelihood of potential damage to downstream ecosystems. Furthermore, our results highlight the need for local protection and sustainable development, as well as suggest that more research is required to better understand the impacts of climatic change and artificial disturbances on peatland degradation. PMID:25369065

Rapid response of hydrological loss of DOC to water table drawdown and warming in Zoige peatland: results from a mesocosm experiment.

PubMed

Lou, Xue-Dong; Zhai, Sheng-Qiang; Kang, Bing; Hu, Ya-Lin; Hu, Li-Le

2014-01-01

A large portion of the global carbon pool is stored in peatlands, which are sensitive to a changing environment conditions. The hydrological loss of dissolved organic carbon (DOC) is believed to play a key role in determining the carbon balance in peatlands. Zoige peatland, the largest peat store in China, is experiencing climatic warming and drying as well as experiencing severe artificial drainage. Using a fully crossed factorial design, we experimentally manipulated temperature and controlled the water tables in large mesocosms containing intact peat monoliths. Specifically, we determined the impact of warming and water table position on the hydrological loss of DOC, the exported amounts, concentrations and qualities of DOC, and the discharge volume in Zoige peatland. Our results revealed that of the water table position had a greater impact on DOC export than the warming treatment, which showed no interactive effects with the water table treatment. Both DOC concentration and discharge volume were significantly increased when water table drawdown, while only the DOC concentration was significantly promoted by warming treatment. Annual DOC export was increased by 69% and 102% when the water table, controlled at 0 cm, was experimentally lowered by -10 cm and -20 cm. Increases in colored and aromatic constituents of DOC (measured by Abs(254 nm), SUVA(254 nm), Abs(400 nm), and SUVA(400 nm)) were observed under the lower water tables and at the higher peat temperature. Our results provide an indication of the potential impacts of climatic change and anthropogenic drainage on the carbon cycle and/or water storage in a peatland and simultaneously imply the likelihood of potential damage to downstream ecosystems. Furthermore, our results highlight the need for local protection and sustainable development, as well as suggest that more research is required to better understand the impacts of climatic change and artificial disturbances on peatland degradation.

Light absorption properties of colored dissolved organic matter (CDOM) in adjacent waters of the Changjiang Estuary during a flood season: implication for DOC estimation

NASA Astrophysics Data System (ADS)

Liu, Yangyang; Shen, Fang; Li, Xiuzhen

2014-11-01

Light absorption properties of colored dissolved organic matter (CDOM) in adjacent waters of the Changjiang Estuary were investigated during the summer of 2013. CDOM absorption showed a substantial portion of the total absorption and clearly dominant among most investigation stations. It generally decreased from the northwest to the southeast, which controlled by physical mixing of fresh water and seawater as was indicated by a conservative behaviour of CDOM. CDOM absorption sharply increased during phytoplankton blooms. Similarly, dissolved organic carbon (DOC) also peaked during blooms period. However, DOC exhibited a more complex behavior relative to a simple conservative mixing, possibly attributed to multiple origins of DOC. CDOM absorption and DOC co-varied to some degree, implying a potential way of DOC estimation from CDOM absorption. However, more detailed information such as CDOM and DOC composition and more validation data were required to obtain a stable CDOM - DOC pattern. Lastly, empirical algorithms with limited data were developed to retrieve CDOM absorption. Further validation of the algorithms were needed when they were to be commonly applied.

PanMetaDocs - A tool for collecting and managing the long tail of "small science data"

NASA Astrophysics Data System (ADS)

Klump, J.; Ulbricht, D.

2011-12-01

In the early days of thinking about cyberinfrastructure the focus was on "big science data". Today, the challenge is not anymore to store several terabytes of data, but to manage data objects in a way that facilitates their re-use. Key to re-use by a user as a data consumer is proper documentation of the data. Also, data consumers need discovery metadata to find the data they need and they need descriptive metadata to be able to use the data they retrieved. Thus, data documentation faces the challenge to extensively and completely describe these objects, hold the items easily accessible at a sustainable cost level. However, data curation and documentation do not rank high in the everyday work of a scientist as a data producer. Data producers are often frustrated by being asked to provide metadata on their data over and over again, information that seemed very obvious from the context of their work. A challenge to data archives is the wide variety of metadata schemata in use, which creates a number of maintenance and design challenges of its own. PanMetaDocs addresses these issues by allowing an uploaded files to be described by more than one metadata object. PanMetaDocs, which was developed from PanMetaWorks, is a PHP based web application that allow to describe data with any xml-based metadata schema. Its user interface is browser based and was developed to collect metadata and data in collaborative scientific projects situated at one or more institutions. The metadata fields can be filled with static or dynamic content to reduce the number of fields that require manual entries to a minimum and make use of contextual information in a project setting. In the development of PanMetaDocs the business logic of panMetaWorks is reused, except for the authentication and data management functions of PanMetaWorks, which are delegated to the eSciDoc framework. The eSciDoc repository framework is designed as a service oriented architecture that can be controlled through a

Simulation of low temperature combustion mechanism of different combustion-supporting agents in close-coupled DOC and DPF system.

PubMed

Jiao, Penghao; Li, Zhijun; Li, Qiang; Zhang, Wen; He, Li; Wu, Yue

2018-07-01

In the coupled Diesel Oxidation Catalyst (DOC) and Diesel Particular Filter (DPF) system, soot cannot be completely removed by only using the passive regeneration. And DPF active regeneration is necessary. The research method in this paper is to spray different kinds of combustion-supporting agents to the DOC in the front of the DPF. Therefore, the low temperature combustion mechanism of different kinds of combustion-supporting agents in DOC was studied, in order to grasp the law of combustion in DOC, and the influence of follow-up emission on DPF removal of soot. During the study, CH 4 H 2 mixture and diesel (n-heptane + toluene) were used as combustion-supporting agents respectively. The simplified mechanisms of two kinds of gas mixtures used as the combustion-supporting agents in DPF have been constructed and testified in the paper. In this paper, the combustion and emission conditions of the two combustion-supporting agents were analyzed so as to meet the practical requirements of different working conditions. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Hydro-climatic control of stream water dissolved organic carbon (DOC) across northern catchments within the North-Watch program

NASA Astrophysics Data System (ADS)

Laudon, Hjalmar; Tetzlaff, Doerthe; Seibert, Jan; Soulsby, Chris; Carey, Sean; Buttle, Jim; McDonnell, Jeff; McGuire, Kevin; Caissie, Daniel; Shanley, Jamie

2010-05-01

There has been an increasing interest in understanding the regulating mechanisms of surface water dissolved organic carbon (DOC) the last decade. A majority of this recent work has been based on individual well characterized research catchments or on regional synoptic datasets combined with readily available landscape and climatic variables. However, as the production and transport of DOC primarily is a function of hydro-climatic conditions a better description of catchment hydrological functioning across large geographic regions would be favorable for moving the mechanistic understanding forward. To do this we report from a first assessment of catchment DOC within the international inter-catchment comparison program North-Watch (http://www.abdn.ac.uk/northwatch/). North-Watch includes long-term research catchments ranging from northern temperate regions to the boreal and sub-arctic biomes with the aim to better understand the variable hydrological and biogeochemical responses in Northern catchments to climate change. The North-Watch catchments are located in Sweden (Krycklan), Scotland (Mharcaidh, Girnock and Strontian), the US (Sleepers River and HJ Andrews) and Canada (Catamaran, Dorset and Wolf Creek). The annual average DOC concentration in the nine catchments investigated were directly linked to hydro-climatic influences (e.g. temperature, water storage) and landscape configuration. In general, the DOC concentration followed a parabolic shape with temperature, where the highest concentrations were found in the boreal and near boreal sites and with the lowest concentrations in the temperate and sub-arctic catchments. The between catchment variability in DOC concentration could also be explained by catchment water storage and amount of wetlands in the catchment. Whereas there is a mechanistic link between long-term climatic conditions and the areal coverage of wetlands, the total catchment storage of water is more strongly linked to topography, parent material

Sources and fate of organic (DOC, POC, CDOM) and inorganic (DIC) carbon in a mangrove dominated estuary (French Guiana)

NASA Astrophysics Data System (ADS)

Ray, R.; Michaud, E.; Vantrepotte, V.; Aller, R. C.; Morvan, S.; Thouzeau, G.

2016-12-01

We studied the mangrove dominated Sinnamary estuarine system in French Guiana during the dry and wet seasons in 2015 to examine the sources, transport and fate of surface water DOC, POC and DIC along the salinity gradient and the effect of tidal fluctuations on carbon dynamics. Elemental ratios, stable isotopes and optical properties (absorption) were applied as proxies to delineate the sources and molecular structure of the organic carbon. Results showed that during the wet season there were significant net inputs of POC and DOC along the salinity gradient from mangroves and enhanced surface runoff. Time series performed during the dry season at a station in channel water adjacent to mangroves revealed mangrove-derived export and exchanges of DOC and POC during the ebb and marine algae import during the flood. DOC was the dominant form of carbon in both seasons with DOC:POC ratios typically between 13 and 40. Both δ13DOC and CDOM descriptors (e.g., S275-295 and a*412) confirmed mangrove litter leaching to be the primary contributor of high molecular weight dissolved organic matter in the wet season which was replaced by marine phytoplanktonic OC during transport offshore in the dry season. CDOM aromaticity is lower in the dry season as mangrove inputs decrease. POC showed similar trends as DOC, with maximum contributions of terrestrial litter in the river and mixing zone, and in situ production dominant in the marine zone. The entire estuary is heterotrophic, exhibiting high pCO2 (837-5575µatm) and oxygen undersaturation (59-86%) in both seasons, and substantial CO2 emission fluxes (278-3671mmol m-2 d-1). Intense local remineralization and laterally transported CO2 originating from mangrove benthic respiration could account for the water column pCO2 enrichment during low tide and night time. Keywords: Organic carbon, stable isotopes, CDOM, pCO2, mangrove, French Guiana

Rotational Modulation and Activity Cycles at Rotational Extremes: 25 yrs of NURO Photometry for HII 1883

NASA Astrophysics Data System (ADS)

Milingo, Jackie; Saar, Steven; Marschall, Laurence

2018-01-01

We present a 25 yr compilation of V-band differential photometry for the Pleiades K dwarf HII 1883 (V660 Tau). HII 1883 has a rotational period of ~ 0.24 d and displays significant rotational modulation due to non-uniform surface brightness or "starspots". Preliminary work yields a cycle period of ~ 9 yrs and rotational shear (ΔP_rot/) considerably less than solar. HII 1883 is one of the fastest rotating single stars with a known cycle. With additional data available we compare newly determined P_cyc and ΔP_rot/ values with those of other stars, putting HII 1883 into the broader context of dynamo properties in single cool dwarfs.

UV-visible absorbance spectroscopy as a proxy for peatland dissolved organic carbon (DOC) quantity and quality: considerations on wavelength and absorbance degradation.

PubMed

Peacock, Mike; Evans, Chris D; Fenner, Nathalie; Freeman, Chris; Gough, Rachel; Jones, Timothy G; Lebron, Inma

2014-05-01

Absorbance in the UV or visible spectrum (UV-vis) is commonly used as a proxy for DOC concentrations in waters draining upland catchments. To determine the appropriateness of different UV-vis measurements we used surface and pore water samples from two Welsh peatlands in four different experiments: (i) an assessment of single wavelength proxies (1 nm increments between 230-800 nm) for DOC concentration demonstrated that 254 nm was more accurate than 400 nm. The highest R(2) values between absorbance and DOC concentration were generated using 263 nm for one sample set (R(2) = 0.91), and 230 nm for the other three sample sets (respective R(2) values of 0.86, 0.81, and 0.93). (ii) A comparison of different DOC concentration proxies, including single wavelength proxies, a two wavelength model, a proxy using phenolic concentration, and a proxy using the area under a UV spectrum at 250-350 nm. It was found that both a single wavelength proxy (≤263 nm) and a two wavelength model performed well for both pore water and surface water. (iii) An evaluation of the E2 : E3, E2 : E4, E4 : E6 ratios, and SUVA (absorbance at 254 nm normalised to DOC concentration) as indicators of DOC quality showed that the E4 : E6 ratio was subject to extensive variation over time, and was highly correlated between surface water and pore water, suggesting that it is a useful metric to determine temporal changes in DOC quality. (iv) A repeated weekly analysis over twelve weeks showed no consistent change in UV-vis absorbance, and therefore an inferred lack of degradation of total DOC in samples that were filtered and stored in the dark at 4 °C.

Integrated bicarbonate-form ion exchange treatment and regeneration for DOC removal: Model development and pilot plant study.

PubMed

Hu, Yue; Boyer, Treavor H

2017-05-15

The application of bicarbonate-form anion exchange resin and sodium bicarbonate salt for resin regeneration was investigated in this research is to reduce chloride ion release during treatment and the disposal burden of sodium chloride regeneration solution when using traditional chloride-form ion exchange (IX). The target contaminant in this research was dissolved organic carbon (DOC). The performance evaluation was conducted in a completely mixed flow reactor (CMFR) IX configuration. A process model that integrated treatment and regeneration was investigated based on the characteristics of configuration. The kinetic and equilibrium experiments were performed to obtain required parameters for the process model. The pilot plant tests were conducted to validate the model as well as provide practical understanding on operation. The DOC concentration predicted by the process model responded to the change of salt concentration in the solution, and showed a good agreement with pilot plant data with less than 10% difference in terms of percentage removal. Both model predictions and pilot plant tests showed over 60% DOC removal by bicarbonate-form resin for treatment and sodium bicarbonate for regeneration, which was comparable to chloride-form resin for treatment and sodium chloride for regeneration. Lastly, the DOC removal was improved by using higher salt concentration for regeneration. Copyright © 2017 Elsevier Ltd. All rights reserved.

TogoDoc server/client system: smart recommendation and efficient management of life science literature.

PubMed

Iwasaki, Wataru; Yamamoto, Yasunori; Takagi, Toshihisa

2010-12-13

In this paper, we describe a server/client literature management system specialized for the life science domain, the TogoDoc system (Togo, pronounced Toe-Go, is a romanization of a Japanese word for integration). The server and the client program cooperate closely over the Internet to provide life scientists with an effective literature recommendation service and efficient literature management. The content-based and personalized literature recommendation helps researchers to isolate interesting papers from the "tsunami" of literature, in which, on average, more than one biomedical paper is added to MEDLINE every minute. Because researchers these days need to cover updates of much wider topics to generate hypotheses using massive datasets obtained from public databases or omics experiments, the importance of having an effective literature recommendation service is rising. The automatic recommendation is based on the content of personal literature libraries of electronic PDF papers. The client program automatically analyzes these files, which are sometimes deeply buried in storage disks of researchers' personal computers. Just saving PDF papers to the designated folders makes the client program automatically analyze and retrieve metadata, rename file names, synchronize the data to the server, and receive the recommendation lists of newly published papers, thus accomplishing effortless literature management. In addition, the tag suggestion and associative search functions are provided for easy classification of and access to past papers (researchers who read many papers sometimes only vaguely remember or completely forget what they read in the past). The TogoDoc system is available for both Windows and Mac OS X and is free. The TogoDoc Client software is available at http://tdc.cb.k.u-tokyo.ac.jp/, and the TogoDoc server is available at https://docman.dbcls.jp/pubmed_recom.

TogoDoc Server/Client System: Smart Recommendation and Efficient Management of Life Science Literature

PubMed Central

Takagi, Toshihisa

2010-01-01

In this paper, we describe a server/client literature management system specialized for the life science domain, the TogoDoc system (Togo, pronounced Toe-Go, is a romanization of a Japanese word for integration). The server and the client program cooperate closely over the Internet to provide life scientists with an effective literature recommendation service and efficient literature management. The content-based and personalized literature recommendation helps researchers to isolate interesting papers from the “tsunami” of literature, in which, on average, more than one biomedical paper is added to MEDLINE every minute. Because researchers these days need to cover updates of much wider topics to generate hypotheses using massive datasets obtained from public databases or omics experiments, the importance of having an effective literature recommendation service is rising. The automatic recommendation is based on the content of personal literature libraries of electronic PDF papers. The client program automatically analyzes these files, which are sometimes deeply buried in storage disks of researchers' personal computers. Just saving PDF papers to the designated folders makes the client program automatically analyze and retrieve metadata, rename file names, synchronize the data to the server, and receive the recommendation lists of newly published papers, thus accomplishing effortless literature management. In addition, the tag suggestion and associative search functions are provided for easy classification of and access to past papers (researchers who read many papers sometimes only vaguely remember or completely forget what they read in the past). The TogoDoc system is available for both Windows and Mac OS X and is free. The TogoDoc Client software is available at http://tdc.cb.k.u-tokyo.ac.jp/, and the TogoDoc server is available at https://docman.dbcls.jp/pubmed_recom. PMID:21179453

Decreasing DOC trends in soil solution along the hillslopes at two IM sites in southern Sweden--geochemical modeling of organic matter solubility during acidification recovery.

PubMed

Löfgren, Stefan; Gustafsson, Jon Petter; Bringmark, Lage

2010-12-01

Numerous studies report increased concentrations of dissolved organic carbon (DOC) during the last two decades in boreal lakes and streams in Europe and North America. Recently, a hypothesis was presented on how various spatial and temporal factors affect the DOC dynamics. It was concluded that declining sulphur deposition and thereby increased DOC solubility, is the most important driver for the long-term DOC concentration trends in surface waters. If this recovery hypothesis is correct, the DOC levels should increase both in the soil solution as well as in the surrounding surface waters as soil pH rises and the ionic strength declines due to the reduced input of SO(4)(2-) ions. In this project a geochemical model was set up to calculate the net humic charge and DOC solubility trends in soils during the period 1996-2007 at two integrated monitoring sites in southern Sweden, showing clear signs of acidification recovery. The Stockholm Humic Model was used to investigate whether the observed DOC solubility is related to the humic charge and to examine how pH and ionic strength influence it. Soil water data from recharge and discharge areas, covering both podzols and riparian soils, were used. The model exercise showed that the increased net charge following the pH increase was in many cases counteracted by a decreased ionic strength, which acted to decrease the net charge and hence the DOC solubility. Thus, the recovery from acidification does not necessarily have to generate increasing DOC trends in soil solution. Depending on changes in pH, ionic strength and soil Al pools, the trends might be positive, negative or indifferent. Due to the high hydraulic connectivity with the streams, the explanations to the DOC trends in surface waters should be searched for in discharge areas and peat lands. Copyright © 2010 Elsevier B.V. All rights reserved.

The use of DOC fluorescence in the study of mercury photochemistry

NASA Astrophysics Data System (ADS)

Amyot, M.; Garcia, E.

2006-12-01

During the past decade, numerous field studies have explored the impact of photochemical processes on the oxidation state of Hg. In the upper zone of most aquatic systems as well as in snow packs, Hg(II) photochemical reduction predominates, whereas in contaminated systems, bacterial reduction may be more important. Recently, photo-assisted microbial reduction was also proposed as a significant mechanism in remote lakes. Many of these processes involve the generation of reactive species during the photodegradation of DOC. In this context, we compared diurnal variations in dissolved gaseous mercury (DGM, mainly formed of Hg(0)) concentration and in losses of DOC fluorescence (DOCF) in four boreal Canadian Shield lakes, in one beaver pond, and in filtered and unfiltered water from a wetland in Lake St. Pierre, a fluvial lake of the St. Lawrence River. These systems were chosen to represent a spectrum of DOC. We also determined the contribution of UVB, UVA and visible light on DGM photo-induced production in the four lakes. Our results showed a strong relationship between DGM concentrations and light intensity and between DGM production and losses in DOCF, in all study sites. We also observed higher rates of DGM formation and of DOCF bleaching in the presence of UV radiation. Under UVB light, production of DGM was higher in clear lakes than in the humic ones. Inversely, in the UVA range, DGM production tended to be higher in humic lakes. We suggest that DOCF bleaching can be used as a proxy for the rate of formation of reactive species that may alter the redox state of mercury in surface waters. We also have indications that DGM production is more important in clear than in humic waters.

Altered cropping pattern and cultural continuation with declined prosperity following abrupt and extreme arid event at ~4,200 yrs BP: Evidence from an Indus archaeological site Khirsara, Gujarat, western India.

PubMed

Pokharia, Anil K; Agnihotri, Rajesh; Sharma, Shalini; Bajpai, Sunil; Nath, Jitendra; Kumaran, R N; Negi, Bipin Chandra

2017-01-01

Archaeological sites hold important clues to complex climate-human relationships of the past. Human settlements in the peripheral zone of Indus culture (Gujarat, western India) are of considerable importance in the assessment of past monsoon-human-subsistence-culture relationships and their survival thresholds against climatic stress exerted by abrupt changes. During the mature phase of Harappan culture between ~4,600-3,900yrsBP, the ~4,100±100yrsBP time slice is widely recognized as one of the major, abrupt arid-events imprinted innumerous well-dated palaeo records. However, the veracity of this dry event has not been established from any archaeological site representing the Indus (Harappan) culture, and issues concerning timing, changes in subsistence pattern, and the likely causes of eventual abandonment (collapse) continue to be debated. Here we show a significant change in crop-pattern (from barley-wheat based agriculture to 'drought-resistant' millet-based crops) at ~4,200 yrs BP, based on abundant macrobotanical remains and C isotopes of soil organic matter (δ13CSOM) in an archaeological site at Khirsara, in the Gujarat state of western India. The crop-change appears to be intentional and was likely used as an adaptation measure in response to deteriorated monsoonal conditions. The ceramic and architectural remains of the site indicate that habitation survived and continued after the ~4,200yrsBP dry climatic phase, but with declined economic prosperity. Switching to millet-based crops initially helped inhabitants to avoid immediate collapse due to climatic stresses, but continued aridity and altered cropping pattern led to a decline in prosperity levels of inhabitants and eventual abandonment of the site at the end of the mature Harappan phase.

Using CDOM optical properties for estimating DOC concentrations and pCO 2 in the Lower Amazon River

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

Valerio, Aline de Matos; Kampel, Milton; Vantrepotte, Vincent

Colored dissolved organic matter (CDOM) is largely responsible for the optical properties of freshwaters and coastal areas and can be used as a proxy to assess the non-optical carbon content as the dissolved organic carbon (DOC) and the partial pressure of carbon dioxide (pCO 2). Nevertheless, riverine studies that explores the former relationship are more challenging due to the spectral mixture caused by the high content of inorganic materials in the suspended sediment. Here we evaluate the spatial-temporal variability of CDOM, DOC and pCO 2, as well as the potential of CDOM absorption coefficient (aCDOM(412)) for estimating DOC concentration andmore » pCO 2 along the lower Amazon River. Our results revealed differences in the dissolved organic matter (DOM) quality between clear water (CW) tributaries and the Amazon River mainstem. A linear relationship between DOC and CDOM was observed when tributaries and mainstem are evaluated separately (Amazon waters: N=42, R2=0.74; CW: N= 13, R2 = 0.57). However, this linear relationship was not observed during periods of higher rainfall and river discharge, requiring a model specific to these time periods to be developed (N = 25, R2 = 0.58). A strong linear positive relation was found between aCDOM(412) and pCO 2( N=69, R2=0.65) along the lower river. pCO 2 was less affected by the optical difference between tributaries and mainstem water or by the presence of higher hygrometric conditions when compared to CDOM to DOC relationships. Including the river water temperature in the model improves our ability to estimate pCO 2 (N=69; R2 = 0.80). Our results also illustrate the complexity of DOM temporal dynamics in the lower Amazon River where the occurrence of extreme high and low discharge due to factors such as El Niño, can significantly alter the expected seasonal oscillation, as was the case during this study period. The ability to remotely assess both DOC and pCO 2 from CDOM optical properties highlight the importance

Seasonal estimates of DOC standing stocks in Apalachicola Bay estuary: Towards a better understanding using field, ocean color and model data

NASA Astrophysics Data System (ADS)

D'Sa, E. J.; Joshi, I.; Osburn, C. L.; Bianchi, T. S.; Ko, D. S.; Oviedo-Vargas, D.; Arellano, A.; Ward, N.

2016-12-01

Apalachicola Bay, a semi-enclosed estuary located in Florida's panhandle, is well known for its water quality and oyster yields. We present the use of combined field and ocean color satellite observations and the outputs of a high-resolution hydrodynamic model to study the influence of physical processes on the distribution and the transport of terrestrially derived CDOM and DOC to shelf waters during the spring and fall of 2015. Determination of DOC stocks were based on the development of a CDOM algorithm (R2 = 0.87, N = 9) for the VIIRS ocean color sensor, and the assessment of CDOM - DOC relationships (R2 = 0.88, N = 13 in March; R2 = 0.83, N = 24 in November) for the Apalachicola Bay. Satellite-derived CDOM and DOC maps together with model-based salinity distributions revealed their spatial extent, sources and transport to the shelf water. Furthermore, strong seasonal influence on DOM distribution in the bay was associated with inputs from Apalachicola and Carrabelle Rivers and the surrounding marshes. Estimates of DOC standing stocks in the bay obtained using ocean color data and high-resolution bathymetry showed relatively higher stocks in November ( 3.71 × 106 kg C, 560 km2) than in March ( 4.07 × 106 kg C, 560 km2) despite lower river discharge in dry season. Results of DOC flux estimates from the bay to coastal waters will also be presented.

High-frequency DOC and nitrate measurements provide new insights into their export and their relationships to rainfall-runoff processes

NASA Astrophysics Data System (ADS)

Schwab, Michael; Klaus, Julian; Pfister, Laurent; Weiler, Markus

2015-04-01

Over the past decades, stream sampling protocols for environmental tracers were often limited by logistical and technological constraints. Long-term sampling programs would typically rely on weekly sampling campaigns, while high-frequency sampling would remain restricted to a few days or hours at best. We stipulate that the currently predominant sampling protocols are too coarse to capture and understand the full amplitude of rainfall-runoff processes and its relation to water quality fluctuations. Weekly sampling protocols are not suited to get insights into the hydrological system during high flow conditions. Likewise, high frequency measurements of a few isolated events do not allow grasping inter-event variability in contributions and processes. Our working hypothesis is based on the potential of a new generation of field-deployable instruments for measuring environmental tracers at high temporal frequencies over an extended period. With this new generation of instruments we expect to gain new insights into rainfall-runoff dynamics, both at intra- and inter-event scales. Here, we present the results of one year of DOC and nitrate measurements with the field deployable UV-Vis spectrometer spectro::lyser (scan Messtechnik GmbH). The instrument measures the absorption spectrum from 220 to 720 nm in situ and at high frequencies and derives DOC and nitrate concentrations. The measurements were carried out at 15 minutes intervals in the Weierbach catchment (0.47 km2) in Luxemburg. This fully forested catchment is characterized by cambisol soils and fractured schist as underlying bedrock. The time series of DOC and nitrate give insights into the high frequency dynamics of stream water. Peaks in DOC concentrations are closely linked to discharge peaks that occur during or right after a rainfall event. Those first discharge peaks can be linked to fast near surface runoff processes and are responsible for a remarkable amount of DOC export. A special characterisation of

A polishing hybrid AER/UF membrane process for the treatment of a high DOC content surface water.

PubMed

Humbert, H; Gallard, H; Croué, J-P

2012-03-15

The efficacy of a combined AER/UF (Anion Exchange Resin/Ultrafiltration) process for the polishing treatment of a high DOC (Dissolved Organic Carbon) content (>8 mgC/L) surface water was investigated at lab-scale using a strong base AER. Both resin dose and bead size had a significant impact on the kinetic removal of DOC for short contact times (i.e. <15 min). For resin doses higher than 700 mg/L and median bead sizes below 250 μm DOC removal remained constant after 30 min of contact time with very high removal rates (80%). Optimum AER treatment conditions were applied in combination with UF membrane filtration on water previously treated by coagulation-flocculation (i.e. 3 mgC/L). A more severe fouling was observed for each filtration run in the presence of AER. This fouling was shown to be mainly reversible and caused by the progressive attrition of the AER through the centrifugal pump leading to the production of resin particles below 50 μm in diameter. More important, the presence of AER significantly lowered the irreversible fouling (loss of permeability recorded after backwash) and reduced the DOC content of the clarified water to l.8 mgC/L (40% removal rate), concentration that remained almost constant throughout the experiment. Copyright © 2011 Elsevier Ltd. All rights reserved.

Using Eco-hydrologic modeling in the Penobscot River Watershed to explore the role of climate and land use change on DOC concentration and flux

NASA Astrophysics Data System (ADS)

Rouhani, S. F. B. B.; Schaaf, C.; Douglas, E. M.; Huntington, T. G.; Kim, J.

2017-12-01

Dissolved Organic Carbon leaches from the terrestrial watersheds to serve as one of the largest sources of marine DOC. Runoff, slope, soil organic matter and land cover characteristics are the primary spatial factors controlling the variability of fluvial Dissolved Organic Carbon fluxes through the catchment. In large, more heterogeneous catchments, streamflow dissolved organic carbon dynamics are regulated by the combined effect of hydrological mechanisms and the proportion of major landscape elements, such as wetland and forested areas. A number of studies have demonstrated that the amount of wetlands, especially peatlands, controls the watershed level transport of DOC in streams.The Penobscot River Watershed is located in north-central Maine and drains into the Gulf of Maine. It is the second largest watershed in New England. The Penobscot River Watershed is primarily forested but also contains extensive bogs, marshes, and wooded swamps.Studying the spatial and temporal changes in DOC export in the Penobscot River Watershed allows us to better understand and detect carbon sinks to carbon source shifts (or vice versa) in northern forested ecosystems.The Regional Hydro-Ecological Simulation System, is a physical process based terrestrial model that has the ability to simulate both the source and transportation of DOC by combining both hydrological and ecological processes. The study is focused on simulating the DOC concentration and flux with RHESSys in the Penobscot River Watershed. The simulated results are compared with field measurements of DOC from the watershed and the model results from the LOADEST and the temporal DOC export patterns are explored. Future changes in the amount of streamflow DOC will also be investigated by using projected land cover and climate change scenarios. Incremental increases in the loss of wetland areas have been implemented to explore the sensitivity of this watershed to wetland loss and progressive changes in forested land cover

Altered cropping pattern and cultural continuation with declined prosperity following abrupt and extreme arid event at ~4,200 yrs BP: Evidence from an Indus archaeological site Khirsara, Gujarat, western India

PubMed Central

Pokharia, Anil K.; Sharma, Shalini; Bajpai, Sunil; Nath, Jitendra; Kumaran, R. N.; Negi, Bipin Chandra

2017-01-01

Archaeological sites hold important clues to complex climate-human relationships of the past. Human settlements in the peripheral zone of Indus culture (Gujarat, western India) are of considerable importance in the assessment of past monsoon-human-subsistence-culture relationships and their survival thresholds against climatic stress exerted by abrupt changes. During the mature phase of Harappan culture between ~4,600–3,900yrsBP, the ~4,100±100yrsBP time slice is widely recognized as one of the major, abrupt arid-events imprinted innumerous well-dated palaeo records. However, the veracity of this dry event has not been established from any archaeological site representing the Indus (Harappan) culture, and issues concerning timing, changes in subsistence pattern, and the likely causes of eventual abandonment (collapse) continue to be debated. Here we show a significant change in crop-pattern (from barley-wheat based agriculture to ‘drought-resistant’ millet-based crops) at ~4,200 yrs BP, based on abundant macrobotanical remains and C isotopes of soil organic matter (δ13CSOM) in an archaeological site at Khirsara, in the Gujarat state of western India. The crop-change appears to be intentional and was likely used as an adaptation measure in response to deteriorated monsoonal conditions. The ceramic and architectural remains of the site indicate that habitation survived and continued after the ~4,200yrsBP dry climatic phase, but with declined economic prosperity. Switching to millet-based crops initially helped inhabitants to avoid immediate collapse due to climatic stresses, but continued aridity and altered cropping pattern led to a decline in prosperity levels of inhabitants and eventual abandonment of the site at the end of the mature Harappan phase. PMID:28985232

Spatial patterns of DOC concentration and DOM optical properties in a Brazilian tropical river-wetland system

NASA Astrophysics Data System (ADS)

Dalmagro, Higo J.; Johnson, Mark S.; de Musis, Carlo R.; Lathuillière, Michael J.; Graesser, Jordan; Pinto-Júnior, Osvaldo B.; Couto, Eduardo G.

2017-08-01

The Cerrado (savanna) and Pantanal (wetland) biomes of Central Western Brazil have experienced significant development activity in recent decades, including extensive land cover conversion from natural ecosystems to agriculture and urban expansion. The Cuiabá River transects the Cerrado biome prior to inundating large areas of the Pantanal, creating one of the largest biodiversity hot spots in the world. We measured dissolved organic carbon (DOC) and the optical absorbance and fluorescence properties of dissolved organic matter (DOM) from 40 sampling locations spanning Cerrado and Pantanal biomes during wet and dry seasons. In the upper, more agricultural region of the basin, DOC concentrations were highest in the rainy season with more aromatic and humified DOM. In contrast, DOC concentrations and DOM optical properties were more uniform for the more urbanized middle region of the basin between wet and dry seasons, as well as across sample locations. In the lower region of the basin, wet season connectivity between the river and the Pantanal floodplain led to high DOC concentrations, a fourfold increase in humification index (HIX) (an indicator of DOM humification), and a 50% reduction in the spectral slope (SR). Basin-wide, wet season values for SR, HIX, and FI (fluorescence index) indicated an increasing representation of terrestrially derived DOM that was more humified. Parallel factor analysis identified two terrestrially derived components (C1 and C2) representing 77% of total fluorescing DOM (fDOM). A third, protein-like fDOM component increased markedly during the wet season within the more urban-impacted region.

Orion EM-1 Interim Cryogenic Propulsion Stage (ICPS) move from HIF to DOC

NASA Image and Video Library

2017-04-12

The Orion EM-1 Interim Cryogenic Propulsion Stage is moved from the Horizontal Integration Facility (HIF) to the Delta Operations Center (DOC) at Cape Canaveral Air Force Station to continue processing for it's future mission on the Space Launch System rocket.

Effect of training mode on post-exercise heart rate recovery of trained cyclists.

PubMed

McDonald, Kelia G; Grote, Silvie; Shoepe, Todd C

2014-06-28

The sympathetic nervous system dominates the regulation of body functions during exercise. Therefore after exercise, the sympathetic nervous system withdraws and the parasympathetic nervous system helps the body return to a resting state. In the examination of this relationship, the purpose of this study was to compare recovery heart rates (HR) of anaerobically versus aerobically trained cyclists. With all values given as means ± SD, anaerobically trained track cyclists (n=10, age=25.9 ± 6.0 yrs, body mass=82.7 ± 7.1 kg, body fat=10.0 ± 6.3%) and aerobically trained road cyclists (n=15, age=39.9 ± 8.5 yrs, body mass=75.3 ± 9.9 kg, body fat=13.1 ± 4.5%) underwent a maximal oxygen uptake test. Heart rate recovery was examined on a relative basis using heart rate reserve as well as the absolute difference between maximum HR and each of two recovery HRs. The post-exercise change in HR at minute one for the track cyclists and road cyclists respectively were 22 ± 8 bpm and 25 ± 12 bpm. At minute two, the mean drop for track cyclists was significantly (p<0.05) greater than the road cyclists (52 ± 15 bpm and 64 ± 11 bpm). Training mode showed statistically significant effects on the speed of heart rate recovery in trained cyclists. Greater variability in recovery heart rate at minute two versus minute one suggests that the heart rate should be monitored longer than one minute of recovery for a better analysis of post-exercise autonomic shift.

Carbon isotopes in peat, DOC, CO{sub 2}, and CH{sub 4} in a Holocene peatland on Dartmoor, southwest England

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

Charman, D.J.; Aravena, R.; Bryant, C.L.

1999-06-01

Carbon gases with younger {sup 14}C ages than those of the surrounding peat have been reported from continental boreal peatlands, a fact which suggests that significant movement of CO{sub 2}, CH{sub 4}, or DOC (dissolved organic carbon) and export of C via subsurface processes are not accounted for in most estimates of contributions to the C cycle. This paper tests the hypothesis that similar processes can occur in oceanic ombrotrophic mires where water and gas movement is theoretically minimal. Measurements of {sup 14}C and {delta}{sup 13}C in CO{sub 2}, CH{sub 4}, and DOC, and of tritium, are reported from depthsmore » to 250 cm at Tor Royal, a raised mire in southwest England. Radiocarbon ages of gases are 1,460 to 500 yr younger than those of peat from the same depths, and CO{sub 2} is consistently younger than CH{sub 4}. DOC is 1,260 to 830 yr younger than the peat, and significant amounts of tritium were found at all depths. Gas ages are mostly intermediate between the age of the peat and that of the DOC, which suggests that C is principally transported as DOC. However, some gases are younger than their associated DOC, which implies that movement of dissolved gases may also take place. {delta}{sup 13}C values in gases suggest that CO{sub 2} reduction is the major pathway for CH{sub 4} production. Transport of C in deep peats is likely to be a significant component in the overall C budget of ombrotrophic oceanic peatlands, and C export via discharge to ground or surface waters may be an important mechanism for gaseous C emissions.« less

DOC and nitrate export linked to dominant rainfall-runoff processes, end-members and seasonality - a long-term high frequency measurement campaign

NASA Astrophysics Data System (ADS)

Schwab, M. P.; Klaus, J.; Pfister, L.; Weiler, M.

2016-12-01

Over the past decades, stream sampling protocols for hydro-geochemical parameters were often limited by logistical and technological constraints. While long-term monitoring protocols were typically based on weekly sampling intervals, high frequency sampling was commonly limited to a few single events. In this contribution, we combined high frequency and long-term measurements to understand DOC and nitrate dynamics in a forest headwater for different runoff events and seasons. Our study area is the forested Weierbach catchment (0.47 km2) in Luxembourg, where the fractured schist bedrock is covered by cambisol soils. The runoff response is characterized by a double peak behaviour. The first peak occurs during or right after a rainfall event triggered by fast near surface runoff generation processes, while a second delayed peak lasts several days and is generated by subsurface flow. This second peak occurs only if a distinct storage threshold of the catchment is exceeded. Our observations were carried out with a field deployable UV-Vis spectrometer measuring DOC and nitrate concentrations in-situ at 15 min intervals for more than two years. In addition, a long-term validation was carried out with data obtained from the analysis of water collected with grab samples. The long-term, high-frequency measurements allowed us to calculate a complete and detailed balance of DOC and nitrate export over two years. Transport behaviour of the DOC and nitrate showed different dynamics between the first and second hydrograph peaks. DOC is mainly exported during the first peaks, while nitrate is mostly exported during the delayed second peaks. Biweekly end-member measurement of soil and groundwater over several years enables us to link the behaviour of DOC and nitrate export to various end-members in the catchment. Altogether, the long-term and high-frequency time series provides the opportunity to study DOC and nitrate export processes without having to just rely only on either a

Hydrologic controls on DOC, As and Pb export from a polluted peatland - the importance of heavy rain events, antecedent moisture conditions and hydrological connectivity

NASA Astrophysics Data System (ADS)

Broder, T.; Biester, H.

2015-08-01

Bogs can store large amounts of lead (Pb) and arsenic (As) from atmospheric deposition of anthropogenic emissions. Pb and As are exported along with dissolved organic carbon (DOC) from these organic-rich systems, but it is not yet clear which hydrological (pre)conditions favor their export. This study combines a 1-year monitoring of precipitation, bog water level and pore water concentration changes with bog discharge and DOC, iron, As and Pb stream concentrations. From these data, annual DOC, As, and Pb exports were calculated. Concentrations ranged from 5 to 30 mg L-1 for DOC, 0.2 to 1.9 μg L-1 for As, and 1.3 to 12 μg L-1 for Pb, with highest concentrations in late summer. As and Pb concentrations significantly correlated with DOC concentrations. Fluxes depended strongly on discharge, as 40 % of As and 43 % of Pb were exported during 10 % of the time with the highest discharge, pointing out the over-proportional contribution of short-time, high-discharge events to annual As, Pb and DOC export. Exponential increase in element export from the bog is explained by connection of additional DOC, As and Pb pools in the acrotelm during water table rise, which is most pronounced after drought. Pb, As and DOC concentrations in pore water provide evidence of an increase in the soluble Pb pool as soon as the peat layer becomes hydrologically connected, while DOC and As peak concentrations in runoff lag behind in comparison to Pb. Our data indicate a distinct bog-specific discharge threshold of 8 L s-1, which is thought to depend mainly on the bogs size and drainage conditions. Above this threshold, element concentrations do not further increase and discharge becomes diluted. Combining pore water and discharge data shows that As and Pb exports are dependent on not only the amount of precipitation and discharge but also on the frequency and depth of water table fluctuations. Comparing the annual bog As and Pb export with element inventories indicates that As is much more

Using stable isotopes to identify the scaling effects of riparian peatlands on runoff generation processes and DOC mobilisation

NASA Astrophysics Data System (ADS)

Tunaley, Claire; Tetzlaff, Doerthe; Soulsby, Chris

2017-04-01

Knowledge of hydrological sources, flow paths, and their connectivity is fundamental to understanding stream flow generation and surface water quality in peatlands. Stable isotopes are proven tools for tracking the sources and flow paths of runoff. However, relativity few studies have used isotopes in peat-dominated catchments. Here, we combined 13 months (June 2014 - July 2015) of daily isotope measurements in stream water with daily DOC and 15 minute FDOM (fluorescent component of dissolved organic matter) data, at three nested scales in NE Scotland, to identify the hydrological processes occurring in riparian peatlands. We investigated how runoff generation processes in a small, riparian peatland dominated headwater catchment (0.65 km2) propagate to larger scales (3.2 km2 and 31 km2) with decreasing percentage of riparian peatland coverage. Isotope damping was most pronounced in the 0.65 km2 catchment due to high water storage in the organic soils which encouraged tracer mixing and resulted in attenuated runoff peaks. At the largest scale, stream flow and water isotope dynamics showed a more flashy response. Particularly insightful in this study was calculating the deviation of the isotopes from the local meteoric water line, the lc-excess. The lc-excess revealed evaporative fractionation in the peatland dominated catchment, particularly during summer low flows. This implied high hydrological connectivity in the form of constant seepage from the peatlands sustaining high baseflows at the headwater scale. This constant connectivity resulted in high DOC concentrations at the peatland site during baseflow ( 5 mg l-1). In contrast, at the larger scales, DOC was minimal during low flows ( 2 mg l-1) due to increased groundwater influence and the disconnection between DOC sources and the stream. Insights into event dynamics through the analysis of DOC hysteresis loops showed slight dilution on the rising limb, the strong influence of dry antecedent conditions and a

Exploring the potential of DOC fluorescence as proxy for groundwater contamination by pesticides

NASA Astrophysics Data System (ADS)

Farlin, Julien; Gallé, Tom; Bayerle, Michael; Pittois, Denis; Huck, viola

2017-04-01

Of the different water quality surrogates the fluorescence of dissolved organic content (FDOC) appears particularly promising due to its sensitivity and specificity. A complete spectrum of FDOC can be obtained using bench top instruments scanning a spectral space going from short wavelength UV to visible blue, yielding a so-called an excitation-emission matrix (EEM). The raw EEM can be either used directly for correlation analysis with the variable of interest, or first decomposed into underlying elements corresponding to different groups of organic compounds displaying similar properties using multiway techniques such as Parallel factor analysis (PARAFAC). Fluorescence spectroscopy has up to now only rarely been applied specifically to groundwater environments. The objective of the project was to explore systematically the possibilities offered by FDOC and PARAFAC for the assessment of groundwater contamination by pesticides, taking into account the transit time from the pesticide source to the groundwater outlet. Three sites corresponding to different transit times were sampled: -one spring regularly contaminated by surface water from a nearby stream (sub-daily to daily response to fast-flow generating storm events) -one spring displaying a weekly to monthly response to interflow -sampling along a flowline consisting of a series of springs and an observation well situated upgradient with mean transit times difference of several years Preliminary results show that a three component PARAFAC model is sufficient to decompose the raw EEMs, which is less than the seven or eight component models often encountered in surface water studies. For the first site, one component in the protein-like region 275(excitation)/310 (emission) nm measured in the stream samples was filtrered completely by the aquifer and did not appear in the spring samples. The other two components followed roughly the trend of the DOC and pesticide breakthrough. For the second site, soil sampling of

Google Docs as a Tool for Collaborative Writing in the Middle School Classroom

ERIC Educational Resources Information Center

Woodrich, Megan; Fan, Yanan

2017-01-01

Aim/Purpose: In this study, the authors examine how an online word processing tool can be used to encourage participation among students of different language backgrounds, including English Language Learners. To be exact, the paper discusses whether student participation in anonymous collaborative writing via Google Docs can lead to more…

Modeling the Space-Time Destiny of Pan-Arctic Permafrost DOC in a Global Land Surface Model: Feedback Implications

NASA Astrophysics Data System (ADS)

Bowring, S.; Lauerwald, R.; Guenet, B.; Zhu, D.; Ciais, P.

2017-12-01

Most global climate models do not represent the unique permafrost soil environment and its respective processes. This significantly contributes to uncertainty in estimating their responses, and that of the planet at large, to warming. Here, the production, transport and atmospheric release of dissolved organic carbon (DOC) from high-latitude permafrost soils into inland waters and the ocean is explicitly represented for the first time in the land surface component (ORCHIDEE-MICT) of a CMIP6 global climate model (IPSL). This work merges two models that are able to mechanistically simulate complex processes for 1) snow, ice and soil phenomena in high latitude environments, and 2) DOC production and lateral transport through soils and the river network, respectively, at 0.5° to 2° resolution. The resulting model is subjected to a wide range of input forcing data, parameter testing and contentious feedback phenomena, including microbial heat generation as the active layer deepens. We present results for the present and future Pan-Arctic and Eurasia, with a focus on the Lena and Mackenzie River basins, and show that soil DOC concentrations, their riverine transport and atmospheric evasion are reasonably well represented as compared to observed stocks, fluxes and seasonality. We show that most basins exhibit large increases in DOC transport and riverine CO2 evasion across the suite of RCP scenarios to 2100. We also show that model output is strongly influenced by choice of input forcing data. The riverine component of what is known as the `boundless carbon cycle' is little-recognized in global climate modeling. Hydrological mobilization to the river network results either in sedimentary settling or atmospheric `evasion', presently amounting to 0.5-1.8 PgC yr-1. Our work aims at filling in these knowledge gaps, and the response of these DOC-related processes to thermal forcing. Potential feedbacks owing to such a response are of particular relevance, given the magnitude

Effect of inorganic N enrichment on basal pelagic production in boreal unproductive lakes along a gradient of DOC concentration - results after 1 year of fertilization

NASA Astrophysics Data System (ADS)

Deininger, Anne; Bergström, Ann-Kristin

2013-04-01

Input of inorganic nitrogen (N) in boreal unproductive lakes is steadily increasing due to anthropogenic deposition and usage of artificial fertilizers. N enrichment is predicted to have a major impact on the ecosystem productivity and food web structure in unproductive clear-water and humic lakes. For a long time, pelagic primary production (PP) has been mainly regarded as being phosphorus (P) limited. However, recent studies have shown that this is not true for unproductive lakes in northern Sweden, where phytoplankton is mainly N limited. Addition of inorganic N should therefore increase phytoplankton growth in these lake ecosystems. Bacterial production (BP) in the pelagic habitat, on the other hand, is usually limited by P. Nevertheless, elevated N could have a stimulating effect on BP through enhanced leakage of dissolved organic carbon (DOC) from phytoplankton following enhanced N availability and higher PP. Further, unproductive lakes vary naturally in their DOC content which affects overall nutrient- (N and P), energy- and carbon availability (light, C) for the basal producers (phytoplankton, bacteria). It is still not clear how higher inorganic N availability affects primary- and bacterial production in the pelagic in lakes with varying DOC content. We subsequently assessed this question by conducting whole-lake fertilization experiments with inorganic N additions in 6 lakes with varying DOC concentrations (2 low DOC; 2 medium DOC; 2 high DOC). For each DOC level one lake functioned as a reference and one was fertilized with N. Year 2011 was a reference year (all lakes) and 2012 was the first year of fertilization (i.e. in 3 lakes). Measurements included basal productivity such as primary production and bacteria production, lake water chemistry and physical parameters (i.e. light, temperature). The results of this study will help to develop a conceptual understanding of how increased inorganic N availability (through land use such as forestry and

DOC export from a peat extraction site in transition to managed restoration - preliminary results of a long-term research project

NASA Astrophysics Data System (ADS)

Rüggen, Norman; Kutzbach, Lars; Kopelke, Susanne; Pfeiffer, Eva-Maria

2013-04-01

Peatlands play a major role in the global cycles of water and carbon. Budgeting carbon fluxes of temperate man-managed peatlands is limited by few available data. The main carbon compounds exported from such sites are CO2, CH4 and laterally exported C compounds (dissolved organic carbon (DOC) and gases). Without reliable estimates of laterally exported carbon from managed peatlands, overall carbon balances of such geoecosystems remain obscure. The Himmelmoor peatland in Schleswig-Holstein is subject to horticultural peat extraction in transition towards managed restoration. One-third of 130 ha of peatland area are already subject to managed restoration, the remaining part is still intensively used as a peat extraction site. Surface water discharge rates are measured by a water head sensor in combination with a rectangular-shaped weir. An October-November data set (54 days period, 2012) shows a distinct base-flow and precipitation-dependent discharge peaks, which were up to five times higher than the base-flow. The observations indicate a poor water storing capacity of the intensively used areas. During this first observation period, almost 65,000 tons of peatland-DOC-bearing water have been discharged into the adjacent river system. DOC concentrations in the discharge water have been measured every 6-12 days with a Total Carbon Analyzer TOC-L (Shimadzu, Japan). Additionally, a field spectrophotometer (spectro::lyser,s-can, Austria) has been employed, for measuring quasi-continuous concentrations of DOC. During the 54 day period, approximately 1.75 g DOC m-2 (or about 1750 kg DOC km-2) has been laterally exported from the peatland. Average DOC concentration was 35.1 ± 4 g l-1. These values range in the same order of magnitude that have been published from managed UK peatlands (Armstrong et al., 2010; Wilson et al., 2011). Preliminary data evaluation of the in-situ field spectrophotometer show that DOC concentrations of discharge water varied up to 1.5 mg L-1 in

Hydrologic controls on DOC, As and Pb export from a polluted peatland - the importance of heavy rain events, antecedent moisture conditions and hydrological connectivity

NASA Astrophysics Data System (ADS)

Broder, T.; Biester, H.

2015-03-01

Bogs can store large amounts of lead (Pb) and arsenic (As) attributed to atmospheric deposition of anthropogenic emissions. Pb and As are exported along with dissolved organic carbon (DOC) in these organic-rich systems, but it is not yet clear which hydrological (pre-)conditions favor their export. This study combines one year continuous monitoring of precipitation, bog water level and pore water concentration changes with bog discharge, DOC, As and Pb stream concentrations and fluxes. Concentrations ranged from 5 to 30 mg L-1 for DOC, 0.2 to 1.9 μg L-1 for As and 1.3 to 12 μg L-1 for Pb with highest concentrations in late summer. As and Pb concentrations significantly correlated with DOC concentrations. Fluxes depended strongly on discharge, as 40% of As and 43% of Pb were exported by the upper 10% of discharge, pointing out the over-proportional contribution of heavy rain and high discharge events to annual As, Pb and DOC export. Exponential increase in element export from the bog is explained by connection of additional DOC, As and Pb pools in the acrotelm during water table rise, which is most pronounced after drought. Pb, As and DOC concentrations in pore water provide evidence of an increase of the soluble Pb pool as soon as the peat layer gets hydrologically connected, while DOC and As peak concentrations in runoff lag in comparison to Pb. Our data indicates a distinct bog-specific discharge threshold of 8 L s-1, which is thought to depend mainly on the bogs size and drainage conditions. Above this threshold element concentration do not further increase and discharge gets diluted. Combining pore water and discharge data shows that As and Pb exports are not only dependent on the amount of precipitation and discharge, but on the frequency and depth of water table fluctuations. Comparing the annual bog As and Pb export with element inventories indicates that As is much more mobilized than Pb, with annual fluxes accounting for 0.85 and 0.27‰ of total As and

The effects of ecological restoration, on soil-pore water quality and DOC concentrations, on a British upland blanket bog.

NASA Astrophysics Data System (ADS)

Qassim, Suzane; Dixon, Simon; Rowson, James; Worrall, Fred; Evans, Martin

2013-04-01

Polluted by past atmospheric deposition, eroded and burnt, the Bleaklow plateau (Peak district National Park, UK) has long been degraded. Peatlands are important carbon reservoirs and can act as sources or sinks of carbon. Dissolved organic carbon (DOC) is carbon lost from peatlands via the fluvial pathway and as the major component of water colour it is costly to remove during water treatment processes. The Bleaklow Summit peatlands, were subjected to a large wildfire in 2003 devegetating 5.5km2. This fire prompted stakeholders to initiate a large-scale programme of restoration of the plateau. This study considered restoration techniques across four sites: all four sites were seeded with lawn grass, limed and fertilised; to raise the pH and allow establishment of vegetation. In addition to these interventions, one site also had a mulch of Calluna vulgaris applied to the surface to allow soil stabilisation and promote vegetation establishment and another site had biodegradable geojute textile mesh installed, to stabilize the steep gully surfaces. Another site had a gully block installed, to reduce peat desiccation and erosion. This study will compare the four restored sites to two types of comparators: bare soil sites where no restoration was undertaken and a naturally vegetated site unaffected by the 2003 wildfire. Each site had six replicate dipwells, installed in two groups of three. The depth to the water table was monitored and soil water samples collected for analysis, monthly for 5 years, from Nov 2006 - Jan 2012. No significant difference in DOC concentration was found between control and treated sites. There was, however, a significant difference in DOC composition between sites and over the 5 year period of monitoring. UV-vis absorbance of the samples is used to quantify the fulvic to humic components of DOC. The vegetated control was not significantly different to the bare sites; however the vegetated control had a significantly greater humic fraction of

Drainage in Shallow Peatlands of Marginal Upland Landscapes: DOC Losses from High Flow Events

NASA Astrophysics Data System (ADS)

Grand-Clement, E.; Anderson, K.; Luscombe, D.; Gatis, N.; Benaud, P.; Brazier, R.

2013-12-01

) and finally headwater catchment-scales. Flow monitoring has been in place at all scales since November 2010. Flow-proportional water samples were collected during a range of events throughout winter 2011 to 2013 and analysed for Dissolved Organic Carbon (DOC) and colour, as these variables were identified as critical, both in terms of carbon cycling and for costly water treatment that currently takes place downstream. DOC fluxes were examined temporarily and spatially in relation to season, drain sizes, and magnitude/frequency of event. First results show higher DOC concentrations during rain events occurring in the summer compared to winter times, due to generally drier conditions. DOC fluxes per 24h rain events reach up to 3g/m2. Such measurements are used to evaluate annual DOC losses at the scale of the whole catchment. This will help improving our understanding of carbon losses and fluxes in streams from damaged peatlands, and further estimate the impact on the supply of ecosystem services, and the potential for improvement that can be expected following restoration.

In Situ Stoichiometry in a Large River: Continuous Measurement of Doc, NO3 and PO4 in the Sacramento River

NASA Astrophysics Data System (ADS)

Downing, B. D.; Pellerin, B. A.; Bergamaschi, B. A.; Saraceno, J.

2011-12-01

Studying controls on geochemical processes in rivers and streams is difficult because concentration and composition often changes rapidly in response to physical and biological forcings. Understanding biogeochemical dynamics in rivers will improve current understanding of the role of watershed sources to carbon cycling, river and stream ecology, and loads to estuaries and oceans. Continuous measurements of dissolved organic carbon (DOC), nitrate (NO3-) and soluble reactive phosphate (SRP) concentrations are now possible, along with some information about DOC composition. In situ sensors designed to measure these constituents provide high frequency, real-time data that can elucidate hydrologic and biogeochemical controls which are difficult to detect using more traditional sampling approaches. Here we present a coupled approach, using in situ optical instrumentation with discharge measurements to provide quantitative estimates of constituent loads to investigate C, NO3- and SRP sources and processing in the Sacramento River, CA, USA. Continuous measurement of DOC concentration was conducted by use of a miniature in situ fluorometer (Turner Designs Cyclops) designed to measure chromophoric dissolved organic matter fluorescence (FDOM) over the course of an entire year. Nitrate was measured concurrently using a Satlantic SUNA and phosphate was measured using a WETLabs model Cycle-P instrument for a two week period in July 2011. Continuous measurement from these instruments paired with continuous measurement of physical water quality variables such as temperature, pH, specific conductance, dissolved oxygen, and turbidity, were used to investigate physical and chemical dynamics of DOC, NO3-, SRP over varying time scales. Deploying these instruments at pre-existing USGS discharge gages allowed for calculation of instantaneous and integrated constituent fluxes, as well as filling in gaps in our understanding biogeochemical processes and transport. Results from the study

48 CFR 1335.016-70 - DOC procedures for the use of broad agency announcements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false DOC procedures for the use of broad agency announcements. 1335.016-70 Section 1335.016-70 Federal Acquisition Regulations System... procedures for the use of broad agency announcements. Procedures for the use of broad agency announcements...

48 CFR 1335.016-70 - DOC procedures for the use of broad agency announcements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false DOC procedures for the use of broad agency announcements. 1335.016-70 Section 1335.016-70 Federal Acquisition Regulations System... procedures for the use of broad agency announcements. Procedures for the use of broad agency announcements...

48 CFR 1335.016-70 - DOC procedures for the use of broad agency announcements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false DOC procedures for the use of broad agency announcements. 1335.016-70 Section 1335.016-70 Federal Acquisition Regulations System... procedures for the use of broad agency announcements. Procedures for the use of broad agency announcements...

48 CFR 1335.016-70 - DOC procedures for the use of broad agency announcements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false DOC procedures for the use of broad agency announcements. 1335.016-70 Section 1335.016-70 Federal Acquisition Regulations System... procedures for the use of broad agency announcements. Procedures for the use of broad agency announcements...

48 CFR 1335.016-70 - DOC procedures for the use of broad agency announcements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false DOC procedures for the use of broad agency announcements. 1335.016-70 Section 1335.016-70 Federal Acquisition Regulations System... procedures for the use of broad agency announcements. Procedures for the use of broad agency announcements...

Preliminary assessment of DOC and THM precursor loads from a freshwater restored wetland, an agricultural field, and a tidal wetland in the Sacramento-San Joaquin River Delta

USGS Publications Warehouse

Fujii, R.; Bergamaschi, B.A.; Ganju, N.K.; Fleck, J.A.; Burow-Fogg, K.R.; Schoellhamer, D.; Deverel, S.J.

2003-01-01

Water exported from the Sacramento-San Joaquin River Delta supplies drinking water to more than 22 million people in California. At certain times of the year, Delta waters contain relatively high concentrations of dissolved organic carbon (DOC) and bromide. During these times, chlorination of Delta water for drinking water disinfection will form disinfection byproducts, such as trihalomethanes (THMs), that can exceed the U.S. Environmental Protection Agency's maximum contaminant level for THMs of 80 mg/L. Important sources of DOC and THM precursors (types of DOC that form THMs when chlorinated) to the Delta include rivers, drainage water from peat islands, water from wetlands and areas with extensive riparian vegetation, and in-channel growth of algae and macrophytes. Due to proposed ecosystem restoration and creation of wetlands in the Delta, there is an urgent need for information on the relative loads of DOC and THM precursors produced from three different land uses: restored wetlands constructed for subsidence mitigation, tidal wetlands, and agricultural operations. We have been conducting research in the Delta to provide this information. A restored wetland and agricultural field located on Twitchell Island, and a tidal wetland on Browns Island have been monitored for flow, DOC, and THM precursors. Initial results indicate that the loads of DOC and THM precursors are similar for the restored wetland (surface water only) and the agricultural field. These land uses produce DOC loads of about 14 and 11 g C/m2/yr, respectively, and THM precursor loads of about 1.7 and 1.0 g THM/m2/yr, respectively. Estimates of DOC and THM precursor loads for the tidal wetland site on Browns Island and seepage associated with the restored wetland are being developed.

A Mixed Methods Analysis of the Effect of Google Docs Environment on EFL Learners' Writing Performance and Causal Attributions for Success and Failure

ERIC Educational Resources Information Center

Seyyedrezaie, Zari Sadat; Ghonsooly, Behzad; Shahriari, Hesamoddin; Fatemi, Hazar Hosseini

2016-01-01

This study investigated the effect of writing process in Google Docs environment on Iranian EFL learners' writing performance. It also examined students' perceptions towards the effects of Google Docs and their perceived causes of success or failure in writing performance. In this regard, 48 EFL students were chosen based on their IELTs writing…

Did A Planet Survive A Post-Main Sequence Evolutionary Event?

NASA Astrophysics Data System (ADS)

Sorber, Rebecca; Jang-Condell, Hannah; Zimmerman, Mara

2018-06-01

The GL86 is star system approximately 10 pc away with a main sequence K- type ~ 0.77 M⊙ star (GL 86A) with a white dwarf ~0.49 M⊙ companion (GL86 B). The system has a ~ 18.4 AU semi-major axis, an orbital period of ~353 yrs, and an eccentricity of ~ 0.39. A 4.5 MJ planet orbits the main sequence star with a semi-major axis of 0.113 AU, an orbital period of 15.76 days, in a near circular orbit with an eccentricity of 0.046. If we assume that this planet was formed during the time when the white dwarf was a main sequence star, it would be difficult for the planet to have remained in a stable orbit during the post-main sequence evolution of GL86 B. The post-main sequence evolution with planet survival will be examined by modeling using the program Mercury (Chambers 1999). Using the model, we examine the origins of the planet: whether it formed before or after the post-main sequence evolution of GL86B. The modeling will give us insight into the dynamical evolution of, not only, the binary star system, but also the planet’s life cycle.

Application of a UV-Vis submersible probe for capturing changes in DOC concentrations across a mire complex during the snowmelt and summer periods

NASA Astrophysics Data System (ADS)

Avagyan, Armine; Runkle, Benjamin; Kutzbach, Lars

2013-04-01

An accurate quantification of dissolved organic carbon (DOC) is crucial for understanding changes in water resources under the influence of climate, land use and urbanization. However, the conventionally used methods do not allow high frequency in situ analyses in remote or hostile environments (e.g., industrial wastewater or during environmental high-flow events, such as snowmelt or floods). In particular, missing measurements during the snowmelt period in landscapes of the boreal region can lead to significant miscalculations in regional carbon budgets. Therefore, the aim of the study was to test the performance of a portable, submersible UV-Vis spectrophotometer (spectro::lyser, s::can Messtechnik GmbH, Austria) during the snowmelt period in a boreal mire-forest catchment, and to provide a conceptual understanding of the spatial and temporal dynamics of DOC concentrations during and after snowmelt. During 2011, water samples were collected from the near-pristine Ust-Pojeg mire complex in northwestern Russia (61° 56'N, 50° 13'E). Sampling started during the spring snowmelt period and continued until late fall. The mire presented a mosaic of different landscape units. The mire consisted of minerogeous (fen), ombrogenous (bog), and transitional forest-mire (lagg) zones. Water samples were taken from the surface across the mire (22 points at 50-m intervals). DOC concentrations were analyzed directly at the study site using a portable, submersible UV-Vis spectrophotometer, which uses high-resolution absorbance measurements over the wavelength range 200-742.5 nm at 2.5-nm intervals as a proxy for DOC content. Because the DOC composition of fluids varies by site, a local calibration replaced the default settings of the spectro::lyser (Global Calibration) to enhance the accuracy of the measurements. To evaluate the local calibration and correct for drift, the same samples (n = 157) were additionally analyzed using the wet persulfate oxidation method (O

Organic carbon isotope constraints on the dissolved organic carbon (DOC) reservoir at the Cryogenian-Ediacaran transition

NASA Astrophysics Data System (ADS)

Jiang, Ganqing; Wang, Xinqiang; Shi, Xiaoying; Zhang, Shihong; Xiao, Shuhai; Dong, Jin

2010-10-01

Prominent negative carbonate carbon isotope (δ 13C carb) anomalies from some Ediacaran successions are accompanied by invariant or decoupled organic carbon isotope (δ 13C org) values and have been interpreted as resulting from the remineralization of a large dissolved organic carbon (DOC) reservoir capable of buffering carbon isotopes of organic matter. This inferred oceanic DOC reservoir was thought to have initiated with the onset of Cryogenian glaciations (ca. 720 Ma) and lasted for millions of years until the late Ediacaran Period (< 560 Ma). Carbon isotope analyses of the basal Doushantuo Formation (ca. 635 Ma) in south China reveal that (1) the cap carbonate has δ 13C org around -26‰ (VPDB) and relatively low Δδ 13C (22 ± 2‰) and (2) the overlying organic-rich black shale and shaly dolostone have more negative δ 13C org (-28‰ to -35‰) and higher Δδ 13C (28‰-30‰). Both δ 13C carb and δ 13C org show a + 6‰ shift within a 4-m-thick interval overlying the Doushantuo cap carbonate. The δ 13C org values of the cap carbonate are associated with low TOC (mostly < 0.1%); their paleoceanographic significance requires further tests in other Ediacaran basins. The co-varying positive shift in δ 13C carb and δ 13C org following cap carbonate deposition is best interpreted as resulting from a rapid increase in organic carbon burial, which may have resulted in the rise of oxygen and heralded the first appearance of animals a few meters above the Doushantuo cap carbonate. The data suggest that a large oceanic DOC reservoir did not exist in the early Ediacaran ocean. Excess oceanic DOC required to explain the Ediacaran Shuram and upper Doushantuo δ 13C excursions, if it existed, had to be developed during the Ediacaran Period after cap carbonate deposition.

eLearning to enhance physician patient communication: a pilot test of "doc.com" and "WebEncounter" in teaching bad news delivery.

PubMed

Daetwyler, Christof J; Cohen, Diane G; Gracely, Edward; Novack, Dennis H

2010-01-01

Physician-patient communication skills help determine the nature and quality of diagnostic information elicited from patients, the quality of the physician's counseling, and the patient's adherence to treatment. In spite of their importance, surveys have demonstrated a wide variability and deficiencies in the teaching of these skills. Describe two specific methodologies for teaching physician-patient communication skills developed at our institution and pilot test them for effectiveness. Between 2004 and 2009 we developed "doc.com," a series of 41 media-rich online modules on all aspects of healthcare communication jointly with the American Academy on Communication in Healthcare. Starting in 2006, we expanded our pre-existing experience with the videoconferencing system "WebOSCE" into the online application "WebEncounter." This new methodology combines practice of communication skills on standardized patients with structured assessment and constructive feedback. We had three randomized groups: controls who did only the assessment parts of a WebOSCE on two occasions, a doc.com group who had doc.com in between the assessment occasions, and a combined group that had both doc.com and a WebEncounter between assessments. We found significant improvement in skills as components were added, and the training program was well received.

Spatial distribution and mobility of organic carbon (POC and DOC) in a coastal Mediterranean environment (Saronikos Gulf, Greece) during 2007-2009 period.

PubMed

Evangeliou, Nikolaos; Florou, Heleny

2013-08-01

Particulate (POC) and dissolved organic carbon (DOC) is an important parameter for the pollution assessment of coastal marine systems, especially those affected by anthropogenic, domestic, and industrial activities. In the present paper, a similar marine system (Saronikos Gulf) located in the west-central Aegean Sea (eastern Mediterranean Sea) was examined, in terms of the temporal and spatial distribution of organic carbon (POC and DOC), with respect to marine sources and pathways. POC was maximum in winter in the Saronikos Gulf, due to the bloom of phytoplankton, whereas in the Elefsis Bay (located in the north side of the Saronikos Gulf) in summer, since phytoplankton grazes in the Bay in the end of summer (except for winter). Approximately 60 % of the bulk DOC of the water column was estimated as non-refractory (labile and semi-labile), due to the major anthropogenic, domestic, and industrial effects of the region and the shallow depths. The spatial distribution of POC and DOC mainly affects the northeastern section of the Gulf, since that region has been accepted major organic discharges for a long time period, in connection to the relatively long renewal times of its waters.

Responses of stream nitrate and DOC loadings to hydrological forcing and climate change in an upland forest of the northeastern United States

NASA Astrophysics Data System (ADS)

Sebestyen, Stephen D.; Boyer, Elizabeth W.; Shanley, James B.

2009-06-01

In coming decades, higher annual temperatures, increased growing season length, and increased dormant season precipitation are expected across the northeastern United States in response to anthropogenic forcing of global climate. We synthesized long-term stream hydrochemical data from the Sleepers River Research Watershed in Vermont, United States, to explore the relationship of catchment wetness to stream nitrate and DOC loadings. We modeled changes in growing season length and precipitation patterns to simulate future climate scenarios and to assess how stream nutrient loadings respond to climate change. Model results for the 2070-2099 time period suggest that stream nutrient loadings during both the dormant and growing seasons will respond to climate change. During a warmer climate, growing season stream fluxes (runoff +20%, nitrate +57%, and DOC +58%) increase as more precipitation (+28%) and quick flow (+39%) occur during a longer growing season (+43 days). During the dormant season, stream water and nutrient loadings decrease. Net annual stream runoff (+8%) and DOC loading (+9%) increases are commensurate with the magnitude of the average increase of net annual precipitation (+7%). Net annual stream water and DOC loadings are primarily affected by increased dormant season precipitation. In contrast, decreased annual loading of stream nitrate (-2%) reflects a larger effect of growing season controls on stream nitrate and the effects of lengthened growing seasons in a warmer climate. Our findings suggest that leaching of nitrate and DOC from catchment soils will be affected by anthropogenic climate forcing, thereby affecting the timing and magnitude of annual stream loadings in the northeastern United States.

Comparison of single-step and two-step purified coagulants from Moringa oleifera seed for turbidity and DOC removal.

PubMed

Sánchez-Martín, J; Ghebremichael, K; Beltrán-Heredia, J

2010-08-01

The coagulant proteins from Moringa oleifera purified with single-step and two-step ion-exchange processes were used for the coagulation of surface water from Meuse river in The Netherlands. The performances of the two purified coagulants and the crude extract were assessed in terms of turbidity and DOC removal. The results indicated that the optimum dosage of the single-step purified coagulant was more than two times higher compared to the two-step purified coagulant in terms of turbidity removal. And the residual DOC in the two-step purified coagulant was lower than in single-step purified coagulant or crude extract. (c) 2010 Elsevier Ltd. All rights reserved.

Representation of riverine DOC within a GCM: First framework for coupling soil carbon and lateral hydrology in MPI-ESM

NASA Astrophysics Data System (ADS)

Brovkin, V.; Gehlot, S.; Hagemann, S.

2017-12-01

The current state of the art General Circulation Models (GCMs) do not consider the lateral transport of dissolved organic carbon (DOC) from land to ocean via rivers/streams and the global carbon budget is primarily evaluated based only on vertical gas exchange processes between land or ocean carbon reservoirs. In high latitudes, the permafrost plays an important role in contributing to riverine organic carbon. Moreover, the vertical gas exchange processes are active during the lateral riverine carbon transport but are not considered in the impact of thawing permafrost on global climate. The interplay between permafrost and lateral hydrology is a substantial factor impacting the organic carbon inflow to the Arctic and its associated atmospheric exchange. In this research, we propose a framework of coupling the soil carbon transport via rivers using the hydrological discharge scheme (HD-Model) of MPI-ESM (Max-Planck Institute for Meteorology Earth System Model). The soil carbon classification is based on the solubility (YASSO soil carbon pools) and their subsequent attribution to the dissolved organic carbon via runoff (fast carbon pool) and baseflow (slow carbon pool). The HD-model, which simulates the river discharge for all land areas at a resolution of 0.5 degree, will be modified with inclusion of the DOC as tracer over test areas. Evaluation of DOC transport scheme is intended at reservoir level via available site measurements. The analysis will include global river networks for organic carbon transport with focus on permafrost and high latitude areas. Decomposition of DOC en-route land to ocean via vertical gas exchange processes will be included.

The physiological response of two green calcifying algae from the Great Barrier Reef towards high dissolved inorganic and organic carbon (DIC and DOC) availability.

PubMed

Meyer, Friedrich Wilhelm; Vogel, Nikolas; Teichberg, Mirta; Uthicke, Sven; Wild, Christian

2015-01-01

Increasing dissolved inorganic carbon (DIC) concentrations associated with ocean acidification can affect marine calcifiers, but local factors, such as high dissolved organic carbon (DOC) concentrations through sewage and algal blooms, may interact with this global factor. For calcifying green algae of the genus Halimeda, a key tropical carbonate producer that often occurs in coral reefs, no studies on these interactions have been reported. These data are however urgently needed to understand future carbonate production. Thus, we investigated the independent and combined effects of DIC (pCO2 402 μatm/ pHtot 8.0 and 996 μatm/ pHtot 7.7) and DOC (added as glucose in 0 and 294 μmol L-1) on growth, calcification and photosynthesis of H. macroloba and H. opuntia from the Great Barrier Reef in an incubation experiment over 16 days. High DIC concentrations significantly reduced dark calcification of H. opuntia by 130 % and led to net dissolution, but did not affect H. macroloba. High DOC concentrations significantly reduced daily oxygen production of H. opuntia and H. macroloba by 78 % and 43 %, respectively, and significantly reduced dark calcification of H. opuntia by 70%. Combined high DIC and DOC did not show any interactive effects for both algae, but revealed additive effects for H. opuntia where the combination of both factors reduced dark calcification by 162 % compared to controls. Such species-specific differences in treatment responses indicate H. opuntia is more susceptible to a combination of high DIC and DOC than H. macroloba. From an ecological perspective, results further suggest a reduction of primary production for Halimeda-dominated benthic reef communities under high DOC concentrations and additional decreases of carbonate accretion under elevated DIC concentrations, where H. opuntia dominates the benthic community. This may reduce biogenic carbonate sedimentation rates and hence the buffering capacity against further ocean acidification.

Examining the interrelationship between DOC, bromide and chlorine dose on DBP formation in drinking water--a case study.

PubMed

Bond, Tom; Huang, Jin; Graham, Nigel J D; Templeton, Michael R

2014-02-01

During drinking water treatment aqueous chlorine and bromine compete to react with natural organic matter (NOM). Among the products of these reactions are potentially harmful halogenated disinfection by-products, notably four trihalomethanes (THM4) and nine haloacetic acids (HAAs). Previous research has concentrated on the role of bromide in chlorination reactions under conditions of a given NOM type and/or concentration. In this study different concentrations of dissolved organic carbon (DOC) from U.K. lowland water were reacted with varying amounts of bromide and chlorine in order to examine the interrelationship between the three reactants in the formation of THM4, dihaloacetic acids (DHAAs) and trihaloacetic acids (THAAs). Results showed that, in general, molar yields of THM4 increased with DOC, bromide and chlorine concentrations, although yields did fluctuate versus chlorine dose. In contrast both DHAA and THAA yields were mainly independent of changes in bromide and chlorine dose at low DOC (1 mg·L(-1)), but increased with chlorine dose at higher DOC concentrations (4 mg·L(-1)). Bromine substitution factors reached maxima of 0.80, 0.67 and 0.65 for the THM4, DHAAs and THAAs, respectively, at the highest bromide/chlorine ratio studied. These results suggest that THM4 formation kinetics depend on both oxidation and halogenation steps, whereas for DHAAs and THAAs oxidation steps are more important. Furthermore, they indicate that high bromide waters may prove more problematic for water utilities with respect to THM4 formation than for THAAs or DHAAs. While mass concentrations of all three groups increased in response to increased bromide incorporation, only the THMs also showed an increase in molar yield. Overall, the formation behaviour of DHAA and THAA was more similar than that of THM4 and THAA. © 2013.

75 FR 16748 - Final Voluntary Product Standard; DOC PS 20-10 “American Softwood Lumber Standard”

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-02

... DEPARTMENT OF COMMERCE National Institute of Standards and Technology [Document Number: 090306279...: National Institute of Standards and Technology, Commerce. ACTION: Notice. SUMMARY: The National Institute of Standards and Technology (NIST) announces voluntary product standard DOC PS 20-10 ``American...

Responses of stream nitrate and DOC loadings to hydrological forcing and climate change in an upland forest of the northeastern United States

USGS Publications Warehouse

Sebestyen, S.D.; Boyer, E.W.; Shanley, J.B.

2009-01-01

In coming decades, higher annual temperatures, increased growing season length, and increased dormant season precipitation are expected across the northeastern United States in response to anthropogenic forcing of global climate. We synthesized long-term stream hydrochemical data from the Sleepers River Research Watershed in Vermont, United States, to explore the relationship of catchment wetness to stream nitrate and DOC loadings. We modeled changes in growing season length and precipitation patterns to simulate future climate scenarios and to assess how stream nutrient loadings respond to climate change. Model results for the 2070-2099 time period suggest that stream nutrient loadings during both the dormant and growing seasons will respond to climate change. During a warmer climate, growing season stream fluxes (runoff+20%, nitrate +57%, and DOC +58%) increase as more precipitation (+28%) and quick flow (+39%) occur during a longer growing season (+43 days). During the dormant season, stream water and nutrient loadings decrease. Net annual stream runoff (+8%) and DOC loading (+9%) increases are commensurate with the magnitude of the average increase of net annual precipitation (+7%). Net annual stream water and DOC loadings are primarily affected by increased dormant season precipitation. In contrast, decreased annual loading of stream nitrate (-2%) reflects a larger effect of growing season controls on stream nitrate and the effects of lengthened growing seasons in a warmer climate. Our findings suggest that leaching of nitrate and DOC from catchment soils will be affected by anthropogenic climate forcing, thereby affecting the timing and magnitude of annual stream loadings in the northeastern United States. Copyright 2009 by the American Geophysical Union.

Complexation of Cd, Ni, and Zn by DOC in polluted groundwater: A comparison of approaches using resin exchange, aquifer material sorption, and computer speciation models (WHAM and MINTEQA2)

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

Christensen, J.B.; Christensen, T.H.

1999-11-01

Complexation of cadmium (Cd), nickel (Ni), and zinc (Zn) by dissolved organic carbon (DOC) in leachate-polluted groundwater was measured using a resin equilibrium method and an aquifer material sorption technique. The first method is commonly used in complexation studies, while the second method better represents aquifer conditions. The two approaches gave similar results. Metal-DOC complexation was measured over a range of DOC concentrations using the resin equilibrium method, and the results were compared to simulations made by two speciation models containing default databases on metal-DOC complexes (WHAM and MINTEQA2). The WHAM model gave reasonable estimates of Cd and Ni complexationmore » by DOC for both leachate-polluted groundwater samples. The estimated effect of complexation differed less than 50% from the experimental values corresponding to a deviation on the activity of the free metal ion of a factor of 2.5. The effect of DOC complexation for Zn was largely overestimated by the WHAM model, and it was found that using a binding constant of 1.7 instead of the default value of 1.3 would improve the fit between the simulations and experimental data. The MINTEQA2 model gave reasonable predictions of the complexation of Cd and Zn by DOC, whereas deviations in the estimated activity of the free Ni{sup 2+} ion as compared to experimental results are up to a factor of 5.« less

78 FR 35093 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel EYE DOC; Invitation for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-11

... DEPARTMENT OF TRANSPORTATION Maritime Administration [Docket No. MARAD-2013 0071] Requested Administrative Waiver of the Coastwise Trade Laws: Vessel EYE DOC; Invitation for Public Comments AGENCY....gov . SUPPLEMENTARY INFORMATION: As described by the applicant the intended service of the vessel EYE...

Constructed wetlands may lower inorganic nutrient inputs but enhance DOC loadings into a drinking water reservoir in North Wales.

PubMed

Scholz, C; Jones, T G; West, M; Ehbair, A M S; Dunn, C; Freeman, C

2016-09-01

The objective of this study was to monitor a newly constructed wetland (CW) in north Wales, UK, to assess whether it contributes to an improvement in water quality (nutrient removal) of a nearby drinking water reservoir. Inflow and outflow of the Free Water Surface (FWS) CW were monitored on a weekly basis and over a period of 6 months. Physicochemical parameters including pH, conductivity and dissolved oxygen (DO) were measured, as well as nutrients and dissolved organic and inorganic carbon (DOC, DIC) concentration. The CW was seen to contribute to water quality improvement; results show that nutrient removal took place within weeks after construction. It was found that 72 % of initial nitrate (N03 (-)), 53 % of initial phosphate (PO4 (3-)) and 35 % of initial biological oxygen demand (BOD) were removed, calculated as a total over the whole sampling period. From our study, it can be concluded that while inorganic nutrients do decline in CWs, the DOC outputs increases. This may suggest that CWs represent a source for DOC. To assess the carbon in- and output a C budget was calculated.

Transport and transformation of soil-derived CO2, CH4 and DOC sustain CO2 supersaturation in small boreal streams.

PubMed

Rasilo, Terhi; Hutchins, Ryan H S; Ruiz-González, Clara; Del Giorgio, Paul A

2017-02-01

Streams are typically supersaturated in carbon dioxide (CO 2 ) and methane (CH 4 ), and are recognized as important components of regional carbon (C) emissions in northern landscapes. Whereas there is consensus that in most of the systems the CO 2 emitted by streams represents C fixed in the terrestrial ecosystem, the pathways delivering this C to streams are still not well understood. We assessed the contribution of direct soil CO 2 injection versus the oxidation of soil-derived dissolved organic C (DOC) and CH 4 in supporting CO 2 supersaturation in boreal streams in Québec. We measured the concentrations of CO 2 , CH 4 and DOC in 43 streams and adjacent soil waters during summer base-flow period. A mass balance approach revealed that all three pathways are significant, and that the mineralization of soil-derived DOC and CH 4 accounted for most of the estimated stream CO 2 emissions (average 75% and 10%, respectively), and that these estimated contributions did not change significantly between the studied low order (≤3) streams. Whereas some of these transformations take place in the channel proper, our results suggest that they mainly occur in the hyporheic zones of the streams. Our results further show that stream CH 4 emissions can be fully explained by soil CH 4 inputs. This study confirms that these boreal streams, and in particular their hyporheic zones, are extremely active processors of soil derived DOC and CH 4 , not just vents for soil produced CO 2 . Copyright © 2016 Elsevier B.V. All rights reserved.

Suburban Soils: Are they the answer in determining factors controlling non-point-source DOC and DON in urban surface waters?

NASA Astrophysics Data System (ADS)

Aitkenhead-Peterson, J. A.

2016-12-01

Generally the quality of urban streams has been attributed to storm water runoff and sewage effluent discharge. Recent work in the upper Trinity Basin downstream from the Dallas/Fort Worth metropolis, TX concluded that sewage effluent only contributed between 1 and 35% of DOC dependent upon the population of the watershed. Change from native to urban land use increased DOC exports to between 938 - 1840 kg km-2 yr-1relative to the 517 kg km-2 yr-1 expected from native land use. Where this excess DOC might come from in an urban ecosystem was addressed in a separate study examining water extractable DOC (WEDOC) and DON (WEDON) in soils of single-family home lawns in Chicago, IL, Frederick, MD, Bryan/College Station, TX and Galveston, TX. These cities were exposed to different sources of sodium. Time of exposure to sodium was considered on the assumption that as new sub-divisions are built, new soil or turfgrass sod is introduced to the site. Exposure times were 0-5, 6-10, 11-20, 21-30 and > 30 yr. Length of exposure time of the soil to the urban environment was significant among the four cities examined for DOC (p < 0.001), DON (p < 0.001), sodium adsorption ratio (p < 0.006) but not for sodium (p = 0.08) or exchangeable sodium percent (ESP) (p = 0.09). In all cities WEDON increased with urban exposure time and in all cities except Galveston WEDOC increased with urban exposure time. Sodium, regardless of its source, explained 60% of the variance in WEDOC and 54% of the variance in WEDON across all cities (n = 136). To determine what other factors might be involved in increasing WEDOC and WEDON losses from suburban soils, backward stepwise regression models were used. Across the four cities, time of urban exposure, soil saturated hydraulic conductivity (Ksat), NO3-N, NH4-N, S, PO4-P, Na, Cu, Ca, Fe and Zn produced a significant model for WEDOC (Adjusted r2 = 0.85; p < 0.001) and Ksat, pH, NH4-N, PO4-P, S, Alkalinity and Cu produced a significant model for WEDON

ES-doc-errata: an issue tracker platform for CMIP6

NASA Astrophysics Data System (ADS)

Ben Nasser, Atef; Levavasseur, Guillaume; Greenslade, Mark; Denvil, Sébastien

2017-04-01

In the context of overseeing the quality of data, and as a result of the inherent complexity of projects such as CMIP5/6, it is a mandatory task to keep track of the status of datasets and the version evolution they sustain in their life-cycle. The ESdoc-errata project aims to keep track of the issues affecting specific versions of datasets/files. It enables users to resolve the history tree of each dataset/file enabling a better choice of the data used in their work based on the data status. The ES-doc-errata project has been designed and built on top of the Parent-IDentifiers handle service that will be deployed in the next iteration of the CMIP project, by ensuring maximum usability of ESGF ecosystem and encapsulated in the ES-doc structure. Consuming PIDs from handle service is guided by a specifically built algorithm that extracts meta-data regarding the issues that may or may not affect the quality of datasets/files and cause newer version to be published replacing older deprecated versions. This algorithm is able to deduce the nature of the flaws to the file granularity, that is of high value to the end-user. This new platform has been designed keeping in mind usability by end-users specialized in the data publishing process or other scientists requiring feedback on reliability of data required for their work. To this end, a specific set of rules and a code of conduct has been defined. A validation process ensures the quality of this newly introduced errata meta-data , an authentication safe-guard was implemented to prevent tampering with the archived data, and a wide variety of tools were put at users disposal to interact safely with the platform including a command-line client and a dedicated front-end.

Effects of ocean acidification and hydrodynamic conditions on carbon metabolism and dissolved organic carbon (DOC) fluxes in seagrass populations.

PubMed

Egea, Luis G; Jiménez-Ramos, Rocío; Hernández, Ignacio; Bouma, Tjeerd J; Brun, Fernando G

2018-01-01

Global change has been acknowledged as one of the main threats to the biosphere and its provision of ecosystem services, especially in marine ecosystems. Seagrasses play a critical ecological role in coastal ecosystems, but their responses to ocean acidification (OA) and climate change are not well understood. There have been previous studies focused on the effects of OA, but the outcome of interactions with co-factors predicted to alter during climate change still needs to be addressed. For example, the impact of higher CO2 and different hydrodynamic regimes on seagrass performance remains unknown. We studied the effects of OA under different current velocities on productivity of the seagrass Zostera noltei, using changes in dissolved oxygen as a proxy for the seagrass carbon metabolism, and release of dissolved organic carbon (DOC) in a four-week experiment using an open-water outdoor mesocosm. Under current pH conditions, increasing current velocity had a positive effect on productivity, but this depended on shoot density. However, this positive effect of current velocity disappeared under OA conditions. OA conditions led to a significant increase in gross production rate and respiration, suggesting that Z. noltei is carbon-limited under the current inorganic carbon concentration of seawater. In addition, an increase in non-structural carbohydrates was found, which may lead to better growing conditions and higher resilience in seagrasses subjected to environmental stress. Regarding DOC flux, a direct and positive relationship was found between current velocity and DOC release, both under current pH and OA conditions. We conclude that OA and high current velocity may lead to favourable growth scenarios for Z. noltei populations, increasing their productivity, non-structural carbohydrate concentrations and DOC release. Our results add new dimensions to predictions on how seagrass ecosystems will respond to climate change, with important implications for the

Effects of ocean acidification and hydrodynamic conditions on carbon metabolism and dissolved organic carbon (DOC) fluxes in seagrass populations

PubMed Central

Jiménez-Ramos, Rocío; Hernández, Ignacio; Bouma, Tjeerd J.; Brun, Fernando G.

2018-01-01

Global change has been acknowledged as one of the main threats to the biosphere and its provision of ecosystem services, especially in marine ecosystems. Seagrasses play a critical ecological role in coastal ecosystems, but their responses to ocean acidification (OA) and climate change are not well understood. There have been previous studies focused on the effects of OA, but the outcome of interactions with co-factors predicted to alter during climate change still needs to be addressed. For example, the impact of higher CO2 and different hydrodynamic regimes on seagrass performance remains unknown. We studied the effects of OA under different current velocities on productivity of the seagrass Zostera noltei, using changes in dissolved oxygen as a proxy for the seagrass carbon metabolism, and release of dissolved organic carbon (DOC) in a four-week experiment using an open-water outdoor mesocosm. Under current pH conditions, increasing current velocity had a positive effect on productivity, but this depended on shoot density. However, this positive effect of current velocity disappeared under OA conditions. OA conditions led to a significant increase in gross production rate and respiration, suggesting that Z. noltei is carbon-limited under the current inorganic carbon concentration of seawater. In addition, an increase in non-structural carbohydrates was found, which may lead to better growing conditions and higher resilience in seagrasses subjected to environmental stress. Regarding DOC flux, a direct and positive relationship was found between current velocity and DOC release, both under current pH and OA conditions. We conclude that OA and high current velocity may lead to favourable growth scenarios for Z. noltei populations, increasing their productivity, non-structural carbohydrate concentrations and DOC release. Our results add new dimensions to predictions on how seagrass ecosystems will respond to climate change, with important implications for the

DOC and DON Dynamics along the Bagmati Drainage Network in Kathmandu Valley

NASA Astrophysics Data System (ADS)

Bhatt, M. P.; McDowell, W. H.

2005-05-01

We studied organic matter dynamics and inorganic chemistry of the Bagmati River in Kathmandu valley, Nepal, to understand the influence of human and geochemical processes on chemical loads along the drainage system. Population density appears to be the most fundamental control on the chemistry of surface waters within the Bagmati drainage system. DOC concentration increases 10-fold with distance downstream (from 2.38 to 23.95 mg/L) and shows a strong relationship with human population density. The composition of river water (nutrients, Cl) suggests that sewage effluent to the river has a major effect on water quality. Concentrations were highest during summer, and lowest during the winter monsoon season. In contrast to DOC, DON concentration shows surprisingly little variation, and tends to decrease in concentration with distance downstream. Ammonium contributes almost all nitrogen in the total dissolved nitrogen fraction and the concentration of nitrate is negligible, probably due to rapid denitrification within the stream channel under relatively low-oxygen conditions. Decreases in sulfate along the stream channel may also be due to the reduction of sulfate to sulfide due to the heavy organic matter loading. Water quality is unacceptable for any use and the whole ecosystem is severely affected within the urban areas. Based on a comparison of downstream and upstream water quality, it appears that human activities along the Bagmati, principally inputs of human sewage, are largely responsible for the changes in surface water chemistry within Kathmandu valley.

Influence of fresh water, nutrients and DOC in two submarine-groundwater-fed estuaries on the west of Ireland.

PubMed

Smith, Aisling M; Cave, Rachel R

2012-11-01

Coastal fresh water sources, which discharge to the sea are expected to be directly influenced by climate change (e.g. increased frequency of extreme weather events). Sea-level rise and changes in rainfall patterns, changes in demand for drinking water and contamination caused by population and land use change, will also have an impact. Coastal waters with submarine groundwater discharge are of particular interest as this fresh water source is very poorly quantified. Two adjacent bays which host shellfish aquaculture sites along the coast of Co. Galway in the west of Ireland have been studied to establish the influence of fresh water inputs on nutrients and dissolved organic carbon (DOC) in each bay. Neither bay has riverine input and both are underlain by the karst limestone of the Burren and are susceptible to submarine groundwater discharge. Water and suspended matter samples were collected half hourly over 13 h tidal cycles over several seasons. Water samples were analysed for nutrients and DOC, while suspended matter was analysed for organic/inorganic content. Temperature and salinity measurements were recorded during each tidal station by SBE 37 MicroCAT conductivity/temperature sensors. Long-term mooring data were used to track freshwater input for Kinvara and Aughinish Bays and compare it with rainfall data. Results show that Kinvara Bay is much more heavily influenced by fresh water input than Aughinish Bay, and this is a strong source of fixed nitrogen to Kinvara Bay. Only during flood events is there a significant input of inorganic nitrogen from fresh water to Aughinish Bay, such as in late November 2009. Fresh water input does not appear to be a significant source of dissolved inorganic phosphate (DIP) to either bay, but is a source of DOC to both bays. C:N ratios of DOC/DON show a clear distinction between marine and terrestrially derived dissolved organic material. Copyright © 2012. Published by Elsevier B.V.

ULTRAVIOLET RADIATION IN NORTH AMERICAN LAKES: ATTENUATION ESTIMATES FROM DOC MEASUREMENTS AND IMPLICATIONS FOR PLANKTON COMMUNITIES

EPA Science Inventory

Climate warming in North America is likely to be accompanied by changes in other environmental stresses such as UV-B radiation. We apply an empirical model to available DOC (dissolved organic C) data to estimate the depths to which 1% of surface UV-B and UV-A radiation penetrate ...

Does DOM properties or the amount of DOC induces iron reduction in topsoil porewater?

NASA Astrophysics Data System (ADS)

Szalai, Zoltán; Ringer, Marianna; Kiss, Klaudia; Perényi, Katalin; Jakab, Gergely

2017-04-01

Iron content of porewater in hydromorphic soils shows high temporal variability. This usually correlates with dissolved organic carbon (DOC) content, but the correlation can be weak in some cases. Some studies suggest that ferrous iron stabilizes organic carbon in dissolved state. On the contrary, other papers report about dissolved iron stabilization by dissolved organic matter (DOM). Present study focuses on this apparent contradiction and on the interaction of organic carbon and iron in hydromorphic soils. Studied gleyic Phaeozems (3 profiles) and mollic Gleysols (3 profiles) are located in Geresdi-dombság (Hungary) and in Danube-Tisza Interfluve (Hungary) respectively. Dynamics of porewater pH, EH, have been recorded by field stations at 20, 40 and 100 cm depth during the growing season with 10 min temporal resolution. Porewater occasionally have also been sampled in each depth. The presence of ferrous iron was detected by dipyridil field test. DOC, dissolved nitrogen (DN) and iron were measured by TOC analyser and fl-AAS. Molecular size and molecular weight were measured by photon correlation spectroscope (DLS and SLS). Textural and mineralogical properties of studied soils were also determined. Relationships among studied parameters were tested by Spearman's rank correlation. The seasonal dynamics of redox potential is primarily controlled by saturation, but spatial differences are also driven by vegetation. The environment is usually reductive for iron oxides between March and July, but intensive daily redox fluctuations could be measured in June and July in some topsoils. Short term temporal variability of redox conditions is depended on the physiological activity of plants. Most of the papers published a range between +100 and +50 mV for iron reduction in aquatic systems. Topsoil porewater measurements show three redox ranges where concentration of dissolved iron has been increased: +320 to +200, +80 to +20 and below-160 mV. These ranges were identified

Effect of Inorganic and Organic Carbon Enrichments (DIC and DOC) on the Photosynthesis and Calcification Rates of Two Calcifying Green Algae from a Caribbean Reef Lagoon.

PubMed

Meyer, Friedrich W; Schubert, Nadine; Diele, Karen; Teichberg, Mirta; Wild, Christian; Enríquez, Susana

2016-01-01

Coral reefs worldwide are affected by increasing dissolved inorganic carbon (DIC) and organic carbon (DOC) concentrations due to ocean acidification (OA) and coastal eutrophication. These two stressors can occur simultaneously, particularly in near-shore reef environments with increasing anthropogenic pressure. However, experimental studies on how elevated DIC and DOC interact are scarce and fundamental to understanding potential synergistic effects and foreseeing future changes in coral reef function. Using an open mesocosm experiment, the present study investigated the impact of elevated DIC (pHNBS: 8.2 and 7.8; pCO2: 377 and 1076 μatm) and DOC (added as 833 μmol L-1 of glucose) on calcification and photosynthesis rates of two common calcifying green algae, Halimeda incrassata and Udotea flabellum, in a shallow reef environment. Our results revealed that under elevated DIC, algal photosynthesis decreased similarly for both species, but calcification was more affected in H. incrassata, which also showed carbonate dissolution rates. Elevated DOC reduced photosynthesis and calcification rates in H. incrassata, while in U. flabellum photosynthesis was unaffected and thalus calcification was severely impaired. The combined treatment showed an antagonistic effect of elevated DIC and DOC on the photosynthesis and calcification rates of H. incrassata, and an additive effect in U. flabellum. We conclude that the dominant sand dweller H. incrassata is more negatively affected by both DIC and DOC enrichments, but that their impact could be mitigated when they occur simultaneously. In contrast, U. flabellum can be less affected in coastal eutrophic waters by elevated DIC, but its contribution to reef carbonate sediment production could be further reduced. Accordingly, while the capacity of environmental eutrophication to exacerbate the impact of OA on algal-derived carbonate sand production seems to be species-specific, significant reductions can be expected under future

Effect of Inorganic and Organic Carbon Enrichments (DIC and DOC) on the Photosynthesis and Calcification Rates of Two Calcifying Green Algae from a Caribbean Reef Lagoon

PubMed Central

Diele, Karen; Teichberg, Mirta; Wild, Christian

2016-01-01

Coral reefs worldwide are affected by increasing dissolved inorganic carbon (DIC) and organic carbon (DOC) concentrations due to ocean acidification (OA) and coastal eutrophication. These two stressors can occur simultaneously, particularly in near-shore reef environments with increasing anthropogenic pressure. However, experimental studies on how elevated DIC and DOC interact are scarce and fundamental to understanding potential synergistic effects and foreseeing future changes in coral reef function. Using an open mesocosm experiment, the present study investigated the impact of elevated DIC (pHNBS: 8.2 and 7.8; pCO2: 377 and 1076 μatm) and DOC (added as 833 μmol L-1 of glucose) on calcification and photosynthesis rates of two common calcifying green algae, Halimeda incrassata and Udotea flabellum, in a shallow reef environment. Our results revealed that under elevated DIC, algal photosynthesis decreased similarly for both species, but calcification was more affected in H. incrassata, which also showed carbonate dissolution rates. Elevated DOC reduced photosynthesis and calcification rates in H. incrassata, while in U. flabellum photosynthesis was unaffected and thalus calcification was severely impaired. The combined treatment showed an antagonistic effect of elevated DIC and DOC on the photosynthesis and calcification rates of H. incrassata, and an additive effect in U. flabellum. We conclude that the dominant sand dweller H. incrassata is more negatively affected by both DIC and DOC enrichments, but that their impact could be mitigated when they occur simultaneously. In contrast, U. flabellum can be less affected in coastal eutrophic waters by elevated DIC, but its contribution to reef carbonate sediment production could be further reduced. Accordingly, while the capacity of environmental eutrophication to exacerbate the impact of OA on algal-derived carbonate sand production seems to be species-specific, significant reductions can be expected under future

Motivation for DOC III: 64-bit digital optical computer

NASA Astrophysics Data System (ADS)

Guilfoyle, Peter S.

1991-09-01

OptiComp has focused on a digital optical logic family in order to capitalize on the inherent benefits of optical computing, which include (1) high FAN-IN and FAN-OUT, (2) low power consumption, (3) high noise margin, (4) high algorithmic efficiency using 'smart' interconnects, and (5) free-space leverage of gate interconnect bandwidth product. Other well-known secondary advantages of optical logic include zero capacitive loading of signals at a detector, zero cross-talk between signals, zero signal dispersion, and minimal clock skew (a few picoseconds or less in an imaging system). The primary focus of this paper is to demonstrate how each of the five advantages can be used to leverage other logic family performance such as GaAs; the secondary attributes are discussed only in the context of introducing the DOC III architecture.

Dissolved Organic Carbon in the Yukon, Tanana and Porcupine Rivers, Alaska

NASA Astrophysics Data System (ADS)

Aiken, G. R.; Striegl, R. G.; Wickland, K. P.; Dornblaser, M. M.; Raymond, P. A.

2006-12-01

river. 14C-DOC values correspond to radiocarbon ages of modern (PR), 282 (TR), and 328 (YR) yrs B.P, indicating the presence of some aged DOC in YR and TR. Comparison of the chemical character of DOC from sites along the YR suggests that most DOC is transported from its source to the Bering Sea with little within river chemical or biological alteration, a result supported by laboratory biodegradation experiments.

An Alternative to EPA Method 9 -- Field Validation of the Digital Opacity Compliance System (DOCS)

DTIC Science & Technology

2005-03-15

at the completion of the Phase I and Phase II DOCS field demonstration. These included the following 1) anemometer, 2) sling psychrometer , 3) Abney...anemometer (Eastern Technical Associates, Inc.) Sky conditions Visual observation Relative Humidity Sling Psychrometer (Eastern Technical Associates...least have access to a range of climatic monitoring equipment including the following 1) anemometer, 2) sling psychrometer , 3) Abney Level (sun angle

Using Google Docs to Enhance the Teacher Work Sample: Building e-Portfolios for Learning and Practice

ERIC Educational Resources Information Center

Gugino, Jessica

2018-01-01

The use of teaching portfolios in teacher education programs is a widely accepted practice. This article describes how a traditional teacher work sample was transformed using the online platform, Google Docs. The use of online digital portfolios may help to satisfy both the need to evaluate teacher candidates' performance in special education…

Light absorption properties of CDOM in the Changjiang (Yangtze) estuarine and coastal waters: An alternative approach for DOC estimation

NASA Astrophysics Data System (ADS)

Yu, Xiaolong; Shen, Fang; Liu, Yangyang

2016-11-01

Field measurements of CDOM absorption properties and DOC concentrations were collected in the Changjiang estuarine and coastal waters from 2011 to 2013. CDOM absorption coefficient at 355 nm (ag (355)) was found to be inversely correlated with salinity, with Pearson's coefficients r of -0.901 and -0.826 for summer and winter observations, respectively. Analysis results of the relationships between salinity and CDOM optical properties (i.e., absorption coefficient and spectral slope) suggested that terrigenous inputs dominated CDOM sources in the Changjiang estuary, but the proportion of terrigenous CDOM declined with increasing salinity. The level of CDOM in the Changjiang estuary was lower compared to some of the major estuaries in the world, which could be attributed to several controlling factors such as vegetation cover in the drainage basin, the origin of recharged streams and high sediment load in the Changjiang estuary. We further evaluated the relationships between CDOM and DOC and their mixing behavior among world's major estuaries. An empirical model was finally developed to estimate DOC concentration from ag (355) and spectral slope S275-295 using a non-linear regression. This empirical relationship was calibrated using the Cal dataset, and was validated with the Val dataset, resulting in an acceptable error with the R2 of 0.746, the RMSE of 20.99 μmol/L and the rMAD of 14.46%.

Motivation for DOC III: 64-bit digital optical computer

NASA Astrophysics Data System (ADS)

Guilfoyle, Peter S.

1991-09-01

This paper suggests a new class of digital logic. OptiComp has focused on a digital optical logic family in order to capitalize on the inherent benefits of optical computing, which include (1) high FAN-IN and FAN-OUT, (2) low power consumption, (3) high noise margin, (4) high algorithmic efficiency using 'smart' interconnects, (5) free space leverage of GIBP (gate interconnect bandwidth product). Other well-known secondary advantages of optical logic include (but are not limited to) zero capacitive loading of signals at a detector, zero cross-talk between signals, zero signal dispersion, minimal clock skew (a few picoseconds or less in an imaging system). The primary focus of this paper is to demonstrate how each of the five advantages can be used to leverage other logic family performance such as GaAs; the secondary attributes will be discussed only in the context of introducing the DOC III architecture.

Physician-to-physician consultation via electronic mail: the Walter Reed Army Medical Center Ask a Doc system.

PubMed

Abbott, Kevin C; Mann, Scott; DeWitt, Daisy; Sales, Linda Youngblood; Kennedy, Sean; Poropatich, Ron K

2002-03-01

Physician-to-physician consultation and discussion have traditionally been conducted by telephone, paper, and "curbside" (face to face meetings). The implementation and use of physician-to-physician consultation via electronic mail in a military health care system has not been reported previously. The group mail function of the Composite Health Care System, the main outpatient medical automation system for the Department of Defense, was modified to create mailgroups for every specialty of the Walter Reed Army Medical Center to facilitate ease of physician-to-physician consultation. This modification was called the "Ask a Doc" system. The system was deployed to a 21-state health care network among triservice participants. There were 3,121 consultations logged from April 22, 1998, to December 31, 2000. Growth in use expanded initially and was sustained during a 3-year period. Average response time to consultations was less than 1 day (11.93 hours). Additional training and maintenance requirements were minimal. In general, the use of electronic consultation mirrored that of clinical practice. Most specialty consultations involved the disciplines of internal medicine. Use of the Ask a Doc system was representative of total clinical workload and increased access to specialty medical care over a wide geographic area. The distribution of use indicated that user statistics were legitimate, and quality improvement programs could easily troubleshoot the system. Ask a Doc was inserted into a regional health care network with minimal cost to support and implement and was sustained with very little effort for 3 years. Barriers to even wider use currently include lack of secure communications and the difficulty in assigning workload credit for electronic consultations.

HRQoL among Older Related HSC Donors (>60 yrs.) is Equivalent to that of Younger Related Donors (18–60 yrs.): An RDSafe Study

PubMed Central

Switzer, Galen E.; Bruce, Jessica; Kiefer, Deidre M.; Kobusingye, Hati; Drexler, Rebecca; Besser, RaeAnne M.; Confer, Dennis L.; Horowitz, Mary M.; King, Roberta J.; Shaw, Bronwen E.; Riches, Marcie; Hayes-Lattin, Brandon; Linenberger, Michael; Bolwell, Brian; Rowley, Scott D.; Litzow, Mark R.; Pulsipher, Michael A.

2016-01-01

The increasing number of older adults with blood-related disorders and the introduction of reduced intensity conditioning regimens has led to increases in hematopoietic stem cell (HSC) transplantation among older adults and a corresponding increase in the age of siblings who donate HSCs to these patients. Data regarding the donation-related experiences of older donors is lacking. The Related Donor Safety Study (RDSafe) aimed to examine/compare health-related quality of life (HRQoL) of older versus younger HSC donors. 60 peripheral blood stem cell (PBSC) donors ages 18–60 and 104 PBSC donors age >60 completed validated questionnaires at pre-donation, 4 weeks and 1 year post-donation. Prior to donation, older donors had poorer general physical health (t=−3.27; p=.001) but better mental health (t=2.11; p<.05). There were no age differences in multiple other donation-related factors. At 4 weeks post-donation, there were no group differences in general physical/mental health, but older donors were less likely to report donation-related pain (t=−2.26; p<.05) and concerns (t=−3.38; p=.001). At both 4 weeks and 1 year post-donation, there were no significant differences in the percentage of each age group feeling physically back to normal or in the number of days it took donors to feel completely well. There was no evidence that increasing age within the older donor group was associated with poorer donation-related HRQoL. Taken together, these data support the current practice of HSC donation by sibling donors above age 60, providing no evidence of worsening HRQoL up to one year after donation in individuals up to age 76. PMID:27751935

Drug concentrations in post-mortem femoral blood compared with therapeutic concentrations in plasma

PubMed Central

Launiainen, Terhi; Ojanperä, Ilkka

2014-01-01

Therapeutic drug concentrations measured in plasma are of limited value as reference intervals for interpretation in post-mortem (PM) toxicology. In this study, drug concentration distributions were studied in PM femoral venous blood from 57 903 Finnish autopsy cases representing all causes of death during an 11-year period. Cause-of-death information was obtained from death certificates issued by forensic pathologists. Median, mean, and upper percentile (90th, 95th, 97.5th) concentrations were calculated for 129 drugs. To illustrate how PM median concentrations relate to established therapeutic ranges in plasma, a PM blood/plasma relationship was calculated for each drug. Males represented 75% of the subjects and showed a lower median age (55 yrs) than females (59 yrs). In 43% of these cases, blood alcohol concentration was higher than 0.2‰, and the median was 1.8‰. Sixty-one (47%) of the 129 drugs showed a PM blood/plasma relationship of 1. For 22 drugs (17%), the relationship was <1, and for 46 drugs (35%), the relationship was >1. No marked correlation was found between the PM blood/plasma relationship and the volume of distribution (Vd). For 36 drugs, more than 10% of cases were fatal poisonings attributed to this drug as the main finding. These drug concentration distributions based on a large database provide a helpful reference not only to forensic toxicologists and pathologists but also to clinical pharmacologists in charge of interpreting drug concentrations in PM cases. © 2013 The Authors. Drug Testing and Analysis published by John Wiley & Sons, Ltd. PMID:23881890

Motivation for DOC III: 64-bit digital optical computer

NASA Astrophysics Data System (ADS)

Guilfoyle, Peter S.

1991-09-01

The objective of this paper is to motivate a new class of digital logic. OptiComp has focused on a digital optical logic family in order to capitalize on the inherent benefits of optical computing, which include: (1) high FAN-IN and FAN-OUT, (2) low power consumption, (3) high noise margin, (4) high algorithmic efficiency using 'smart' interconnects, (5) free space leverage of GIBP (gate interconnect bandwidth product). Other well-known secondary advantages of optical logic include (but are not limited to): zero capacitive loading of signals at a detector, zero cross-talk between signals, zero signal dispersion, and minimal clock skew (a few picoseconds or less in an imaging system). The primary focus of this paper is on demonstrating how each of the five advantages can be used to leverage other logic family performance such as GaAs; the secondary attributes will be discussed only in the context of introducing the DOC III architecture.

Developing palaeolimnological records of organic content (DOC and POC) using the UK Acid Water Monitoring Network sites

NASA Astrophysics Data System (ADS)

Russell, Fiona; Chiverrell, Richard; Boyle, John

2016-04-01

Monitoring programmes have shown increases in concentrations of dissolved organic matter (DOM) in the surface waters of northern and central Europe (Monteith et al. 2007), and negative impacts of the browning of river waters have been reported for fish populations (Jonsson et al. 2012; Ranaker et al. 2012) and for ecosystem services such as water treatment (Tuvendal and Elmqvist 2011). Still the exact causes of the recent browning remain uncertain, the main contenders being climate change (Evans et al. 2005) and reduced ionic strength in surface water resulting from declines in anthropogenic sulphur and sea salt deposition (Monteith et al. 2007). There is a need to better understand the pattern, drivers and trajectory of these increases in DOC and POC in both recent and longer-term (Holocene) contexts to improve the understanding of carbon cycling within lakes and their catchments. In Britain there are some ideal sites for testing whether these trends are preserved and developing methods for reconstructing organic fluxes from lake sedimentary archives. There is a suite of lakes distributed across the country, the UK Acid Waters Monitoring Network (UKAWMN) sites, which have been monitored monthly for dissolved organic carbon and other aqueous species since 1988. These 12 lakes have well studied recent and in some case whole Holocene sediment records. Here four of those lakes (Grannoch, Chon, Scoat Tarn and Cwm Mynach) are revisited, with sampling focused on the sediment-water interface and very recent sediments (approx.150 years). At Scoat Tarn (approx. 1000 years) and Llyn Mynach (11.5k years) longer records have been obtained to assess equivalent patterns through the Holocene. Analyses of the gravity cores have focused on measuring and characterising the organic content for comparison with recorded surface water DOC measurements (UKAWMN). Data from pyrolysis measurements (TGA/DSC) in an N atmosphere show that the mass loss between 330-415°C correlates well with

Pre-menarcheal physical activity predicts post-menarcheal lean mass and core strength, but not fat mass

PubMed Central

Day, M.A.; Dowthwaite, J.N.; Rosenbaum, P.F.; Roedel, G.G.; Brocker, A.A.; Scerpella, T.A.

2015-01-01

Objectives: Youth exercise is associated with improved body composition, but details regarding timing and persistence are limited. We examined pre- and circum-menarcheal organized physical activity exposure (PA) as a factor in development of early post-menarcheal lean mass, fat mass and muscle strength. Methods: Participants in a longitudinal study of musculoskeletal growth using dual energy X-ray absorptiometry (DXA) were included based on: 1) Whole body DXA scans: 0.5-1.5 years pre-menarche, 0.5-1.5 years post-menarche; 2) PA records for ≥6 months preceding the first DXA (PREPA) and for the inter-DXA interval (CIRCUMPA). Dominant arm grip strength and sit-ups tests coincided with DXA scans; PA, height and maturity were recorded semi-annually. Regressions correlated PA with lean mass/fat mass/strength, accounting for maturity, body size, and baseline values. Results Seventy girls [baseline: 11.8 yrs (sd 1.0), follow-up: 13.9 years (sd 1.0)] demonstrated circum-menarcheal gains of 25-29% for lean and fat mass and 33% for grip strength. PREPA correlated with pre- and post-menarcheal lean mass, sit-ups and pre-menarcheal fat mass (p<0.05), but not grip strength. CIRCUMPA correlated with only post-menarcheal sub-head lean mass (p=0.03). Conclusions: Lean mass and core strength at 1-year post-menarche were more strongly predicted by pre-menarcheal organized PA than by recent circum-menarcheal PA. PMID:26636280

40 CFR Table Tt-1 to Subpart Tt - Default DOC and Decay Rate Values for Industrial Waste Landfills

Code of Federal Regulations, 2012 CFR

2012-07-01

... Industrial Waste Landfills TT Table TT-1 to Subpart TT Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Waste Landfills Pt. 98, Subpt. TT, Table TT Table TT-1 to Subpart TT—Default DOC and Decay Rate Values for Industrial...

University of Maryland MRSEC - Directory

Science.gov Websites

; Biochemistry 2003-2006 IRG 1 Post-Docs Ajmi Ben Haj Hammouda Ben Haj Hammouda, Ajmi Faculty Research Assistant IRG 2 Post-Docs Lee, SeongSu Postdoc, Rutgers University, Physics 2007-2008 IRG 2 Andrei Sushkov Chung Chung, SeokHwan Asst. Res. Scientist, Electrical & Computer Engineering 2010-2011 Seed Post

Effects of post-traumatic growth on the dorsolateral prefrontal cortex after a disaster

PubMed Central

Nakagawa, Seishu; Sugiura, Motoaki; Sekiguchi, Atsushi; Kotozaki, Yuka; Miyauchi, Carlos Makoto; Hanawa, Sugiko; Araki, Tsuyoshi; Takeuchi, Hikaru; Sakuma, Atsushi; Taki, Yasuyuki; Kawashima, Ryuta

2016-01-01

The relating to others factor of post-traumatic growth (PTG), which involves mutual help and a strong sense of connection with humanity, is important for young people who are coping with stress. The prefrontal cortex (PFC), especially the dorsolateral PFC (DLPFC), may play an important role in post-traumatic stress disorder (PTSD) with regard to coping and resilience. We hypothesized that the neural correlates of PTG may be responsible for resilience to the correlates of PTSD. Our study tested this hypothesis by examining whether measures of PTG, particularly the measures of relating to others after a disaster, were associated with increased regional grey matter volume (rGMV) in the PFC by assessing individuals who had experienced the East Japan Great Earthquake. We calculated the delta-rGMV by subtracting the rGMV obtained 3 months before the disaster from the rGMV obtained after this disaster using voxel-based morphometry. The magnetic resonance imaging data obtained from 26 subjects (M/F: 21/5; age: 21.2 ± 1.6 yrs.) showed that the total scores on a PTG inventory and the subscore for relating to others at the post-assessment were positively and significantly associated with the delta-rGMV in the right DLPFC. The DLPFC seems to be the main neural correlate of PTG. PMID:27670443

Spatio-temporal variability of dissolved organic nitrogen (DON), carbon (DOC), and nutrients in the Nile River, Egypt.

PubMed

Badr, El-Sayed A

2016-10-01

Increases in human activity have resulted in enhanced anthropogenic inputs of nitrogen (N) and carbon (C) into the Nile River. The Damietta Branch of the Nile is subject to inputs from industrial, agricultural, and domestic wastewater. This study investigated the distribution and seasonality of dissolved organic nitrogen (DON), dissolved organic carbon (DOC), and nutrients in the Nile Damietta Branch. Water samples were collected from 24 sites between May 2009 and February 2010. Dissolved organic nitrogen concentrations averaged 251 ± 115 μg/l, with a range of 90.2-671 μg/l, and contributed 40.8 ± 17.7 % to the total dissolved nitrogen (TDN) pool. Relative to autumn and winter, DON was a larger fraction of the TDN pool during spring and summer indicating the influence of bacterioplankton on the nitrogen cycle. Concentrations of DOC ranged from 2.23 to 11.3 mg/l with an average of 5.15 ± 2.36 mg/l, reflecting a high organic matter load from anthropogenic sources within the study area, and were highest during autumn. Higher values of biochemical oxygen demand (BOD), chemical oxygen demand (COD), DON, nitrate, and phosphate occurred downstream of the Damietta Branch and were probably due to anthropogenic inputs to the Nile from the Damietta district. A bacterial incubation experiment indicated that 52.1-95.0 % of DON was utilized by bacteria within 21 days. The decrease in DON concentration was accompanied by an increase in nitrate concentration of 54.8-87.3 %, presumably through DON mineralization. Based on these results, we recommend that water quality assessments consider DON and DOC, as their omission may result in an underestimation of the total organic matter load and impact.

Exploring the Effects of Employing Google Docs in Collaborative Concept Mapping on Achievement, Concept Representation, and Attitudes

ERIC Educational Resources Information Center

Lin, Yu-Tzu; Chang, Chia-Hu; Hou, Huei-Tse; Wu, Ke-Chou

2016-01-01

This study investigated the effectiveness of using Google Docs in collaborative concept mapping (CCM) by comparing it with a paper-and-pencil approach. A quasi-experimental study was conducted in a physics course. The control group drew concept maps using the paper-and-pencil method and face-to-face discussion, whereas the experimental group…

Increased groundwater to stream discharge from permafrost thawing in the Yukon River basin: Potential impacts on lateral export of carbon and nitrogen

USGS Publications Warehouse

Walvoord, Michelle Ann; Striegl, Robert G.

2007-01-01

Arctic and subarctic watersheds are undergoing climate warming, permafrost thawing, and thermokarst formation resulting in quantitative shifts in surface water - groundwater interaction at the basin scale. Groundwater currently comprises almost one fourth of Yukon River water discharged to the Bering Sea and contributes 5-10% of the dissolved organic carbon (DOC) and nitrogen (DON) and 35-45% of the dissolved inorganic carbon (DIC) and nitrogen (DIN) loads. Long-term strearnflow records (>30 yrs) of the Yukon River basin indicate a general upward trend in groundwater contribution to streamflow of 0.7-0.9%/yr and no pervasive change in annual flow. We propose that the increases in groundwater contributions were caused predominately by climate warming and permafrost thawing that enhances infiltration and supports deeper flowpaths. The increased groundwater fraction may result in decreased DOC and DON and increased DIC and DIN export when annual flow remains unchanged.

Schedule for personality assessment from notes and documents (SPAN-DOC): Preliminary validation, links to the ICD-11 classification of personality disorder, and use in eating disorders.

PubMed

Kim, Youl-Ri; Tyrer, Peter; Lee, Hong-Seock; Kim, Sung-Gon; Connan, Frances; Kinnaird, Emma; Olajide, Kike; Crawford, Mike

2016-05-01

The underlying core of personality is insufficiently assessed by any single instrument. This has led to the development of instruments adapted for written records in the assessment of personality disorder. To test the construct validity and inter-rater reliability of a new personality assessment method. This study (four parts) assessed the construct validity of the Schedule for Personality Assessment from Notes and Documents (SPAN-DOC), a dimensional assessment from clinical records. We examined inter-rater reliability using case vignettes (Part 1) and convergent validity in three ways: by comparison with NEO Five-Factor Inventory in 130 Korean patients (Part 2), with agreed ICD-11 personality severity levels in two populations (Part 3) and determining its use in assessing the personality status in 90 British patients with eating disorders (Part 4). Internal consistency (alpha = .90) and inter-rater reliability (intraclass correlation coefficient ≥ .88) were satisfactory. Each factor in the five-factor model of personality was correlated with conceptually valid SPAN-DOC variables. The SPAN-DOC domain traits in those with eating disorders were categorized into 3 clusters: self-aggrandisement, emotionally unstable, and anxious/dependent. This study provides preliminary support for the usefulness of SPAN-DOC in the assessment of personality disorder. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

40 CFR Table Tt-1 to Subpart Tt of... - Default DOC and Decay Rate Values for Industrial Waste Landfills

Code of Federal Regulations, 2013 CFR

2013-07-01

... Industrial Waste Landfills TT Table TT-1 to Subpart TT of Part 98 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Waste... for Industrial Waste Landfills Industry/Waste Type DOC(weight fraction, wet basis) k[dry climatea] (yr...

40 CFR Table Tt-1 to Subpart Tt of... - Default DOC and Decay Rate Values for Industrial Waste Landfills

Code of Federal Regulations, 2014 CFR

2014-07-01

... Industrial Waste Landfills TT Table TT-1 to Subpart TT of Part 98 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Industrial Waste... for Industrial Waste Landfills Industry/Waste Type DOC(weight fraction, wet basis) k[dry climatea] (yr...

Effect of wildfires on physicochemical changes of watershed dissolved organic matter.

PubMed

Revchuk, Alex D; Suffet, I H

2014-04-01

Physicochemical characterization of dissolved organic carbon (DOC) provides essential data to describe watershed characteristics after drastic changes caused by wildfires. Post-fire watershed behavior is important for water source selection, management, and drinking water treatment optimization. Using ash and other burned vegetation fragments, a leaching procedure was implemented to describe physicochemical changes to watershed DOC caused by wildfires. Samples were collected after the 2007 and 2009 wildfires near Santa Barbara, California. Substantial differences in size distribution (measured by ultrafiltration), polarity (measured by polarity rapid assessment method), and the origin of leached DOC (measured by fluorescence) were observed between burned and unburned sites. Recently burned ash had 10 times the DOC leaching potential, and was dominated by large size fragments, compared to weathered 2-year-old ash. Charged DOC fractions were found to positively correlate with DOC size, whereas hydrophobic and hydrophilic DOC fractions were not. Proteins were only observed in recently burned ash and were indicative of recent post-fire biological activity.

Social Constructivist Approach to Web-Based EFL Learning: Collaboration, Motivation, and Perception on the Use of Google Docs

ERIC Educational Resources Information Center

Liu, Sarah Hsueh-Jui; Lan, Yu-Ju

2016-01-01

This study reports on the differences in motivation, vocabulary gain, and perceptions on using or the Google Docs between individual and collaborative learning at a tertiary level. Two classes of English-as-a-Foreign Language (EFL) students were recruited and each class was randomly assigned into one of the two groups--individuals or…

High-resolution analysis of the terrestrial influence on DOC and POC export in a Siberian Arctic River during the spring freshet

NASA Astrophysics Data System (ADS)

Myers-Pigg, A.; Teisserenc, R.; Tananaev, N.; Louchouarn, P.

2015-12-01

Arctic Rivers transport vast amounts of terrestrial organic material (TOM) to the Arctic Ocean. The Yenisei River delivers ~18% of total dissolved organic carbon (DOC) exported to the Arctic Ocean each year during peak river discharge (May-June), known as the spring freshet. Previously published DOC fluxes for the freshet period extrapolate from relatively few data points, due to the uniquely difficult sampling conditions during this dynamic period. Here, we present new high resolution data collected from an extensive sampling campaign from April-July 2014 using a reverse osmosis system for DOC isolation. The similarity between the calculated DOC load delivered during the 2014 freshet (2.94 TgC) and the ten-year average from the previous decade (2.92 TgC for 1999-2008) validates the methodological approach used here. In contrast, the total measured load of polymeric lignin phenols (∑8: 643 Gg), an indicator of TOM input, was one order of magnitude higher than a previously estimated load (42 Gg) for May-June. Hence, we may need to re-evaluate the magnitude of terrestrial carbon exported, including the efficiencies of different sampling methods. Additionally, we present the first simultaneous particulate and dissolved lignin analyses in a major Arctic river. Approximately 30% of the total lignin flux in the Yenisei River is delivered in the particulate phase. Particulate lignin export is decoupled from dissolved lignin during the freshet; the initial flush is dominated by dissolved lignin, while the latter portion of the freshet is dominated by particulate lignin. The chemical signatures of lignin in both phases are similar throughout the freshet, suggesting a mobilization of the same source of carbon each spring. This conclusion is at odds with reported isotopic sources signatures (14C age) of bulk organic matter and lignin in these rivers, requiring a multi-faceted approach to fully understand the sources and ages of terrestrial organic matter in Arctic rivers.

55,000 yrs of Environmental Change in the Southern Hemisphere: Peat Stratigraphy and Inorganic Geochemistry of Lynch's Crater, NE Queensland, Australia.

NASA Astrophysics Data System (ADS)

Muller, J.; Kylander, M. E.; Wust, R. A.; Weiss, D. J.

2005-12-01

This study presents one of the first applications of geochemical proxies to define changes in vegetation, hydrology and atmospheric dust recorded in a peat deposit in the Southern Hemisphere. The Lynch's Crater archive has captured local, regional and global environmental changes and reveals dynamic ecosystem changes as a result of climate shifts over the past 55,000 yrs BP. The 13 m peat record consists of 1.5 m of ombrotrophic peat underlain by a minerotrophic peat. The ombrotrophic section consists of low inorganic content ("ash") and low pH, as expected in of an ombrotrophic environment. The minerotrophic section contains several layers, up to a few cm thick, where abundant sponge spicules, diatom fragments and detrital quartz are indicative of high algal and protista productivity. These layers are characterised by high (up to 50%) ash, indicating persistent flooding of the peat deposits of Lynch's Crater and signalling periods of change in precipitation in North Queensland, Australia. Geochemical data are used to differentiate between climatic episodes associated with flooding events and internal and external atmospheric dust fluxes. Lead isotopes with lithogenic and chalcophile elements tell us that two distinctive sources are prevalent in the Lynch's Crater record. Most of the inorganic fractions of the deposits have the same geochemical signatures as the rocks and sediments of the crater wall, with low As concentrations, high Al, Ti and Sc concentrations and a more radiogenic Pb isotope signature. Influence from long-range dust is distinguished in the lower sections of the core (~35,000-55,000 cal yrs BP) where increases in As concentrations and less radiogenic Pb isotopes are found. Leading up to the Holocene (~35,000-10,000) the influence of increased dust influx becomes more significant (increasing lithogenics, chalcophiles and ash content) and where possible long-range sources are still active, but diluted by a prevailing dominance of the local sources

Dissolved organic carbon (DOC) in soil extracts investigated by FT-ICR-MS

NASA Astrophysics Data System (ADS)

Hofmann, D.; Steffen, D.; Jablonowski, N. D.; Burauel, P.

2012-04-01

Soil drying and rewetting usually increases the release of xenobiotics like pesticides present in agricultural soils. Besides the effect on the release of two aged 14C-labeled pesticide residues we focus on the characterisation of simultaneously remobilized dissolved organic carbon (DOC) to gain new insights into structure and stability aspects of soil organic carbon fractions. The test soil (gleyic cambisol; Corg 1.2%, pH 7.2) was obtained from the upper soil layer of two individual outdoor lysimeter studies containing either environmentally long-term aged 14C residues of the herbicide ethidimuron (0-10 cm depth; time of aging: 9 years) or methabenzthiazuron (0-30 cm depth; time of aging: 17 years). Soil samples (10 g dry soil equivalents) were (A=dry/wet) previously dried (45°C) or (B=wet/wet) directly mixed with pure water (1+2, w:w), shaken (150 rpm, 1 h), and centrifuged (2000 g). This extraction procedure was repeated several individual times, for both setups. The first three individual extractions, respectively were used for further investigations. Salt was removed from samples prior analysis because of a possible quench effect in the electrospray (ESI) source by solid phase extraction (SPE) with Chromabond C18 Hydra-cartridges (Macherey-Nagel) and methanol as backextraction solvent. The so preconcentrated and desalted samples were introduced by flow injection analysis (FIA) in a fourier transform ion cyclotron resonance mass spectrometer (FT-ICR-MS), equipped with an ESI source and a 7 T supra-conducting magnet (LTQ-FT Ultra, ThermoFisher Scientific). This technique is the key technique for complex natural systems attributed by their outstanding mass resolution (used 400.000 at m/z 400 Da) and mass accuracy (≤ 1ppm) by simultaneously providing molecular level details of thousands of compounds and was successful applied for the investigations of natural organic matter (NOM) different sources like marine and surface water, soil, sediment, bog and crude oil

Fish Scale Evidence for Rapid Post Glacial Colonization of an Atlantic Coastal Pond

NASA Technical Reports Server (NTRS)

Daniels, R. A.; Peteet, Dorothy

1996-01-01

Fish scales from the sediment of Allamuchy Pond, New Jersey, USA, indicate that fishes were present in the pond within 400 years of the time of the first deposition of organic material, at approximately 12,600 yrs BP. The earliest of the scales, from a white sucker, Catostomus commersoni, appears in sediment dated 12,260 +/- 220 yrs BP. Presence of scales in sediment deposited before I 0,000 yrs BP indicates that Atlantic salmon, Salmo salar, sunfish, Lepomis sp., and yellow perch, Perca flavescens, also were early inhabitants of the pond. The timing of the arrival of each of these fishes suggests that they migrated out from Atlantic coastal refugia. A minnow scale, referred to Phoxininae, was also retrieved; it could not be matched to any cyprinid currently found in northeastern North America. The species present historically in this pond are from five families found currently in ponds throughout the Northeast and sugoest that the lentic palaeo-enviromnent was similar to present mid-elevation or high-latitude lentic systems.

Use of the 9-item Shared Decision Making Questionnaire (SDM-Q-9 and SDM-Q-Doc) in intervention studies-A systematic review.

PubMed

Doherr, Hanna; Christalle, Eva; Kriston, Levente; Härter, Martin; Scholl, Isabelle

2017-01-01

The Shared Decision Making Questionnaire (SDM-Q-9 and SDM-Q-Doc) is a 9-item measure of the decisional process in medical encounters from both patients' and physicians' perspectives. It has good acceptance, feasibility, and reliability. This systematic review aimed to 1) evaluate the use of the SDM-Q-9 and SDM-Q-Doc in intervention studies on shared decision making (SDM) in clinical settings, 2) describe how the SDM-Q-9 and SDM-Q-Doc performed regarding sensitivity to change, and 3) assess the methodological quality of studies and study protocols that use the measure. We conducted a systematic review of studies published between 2010 and October 2015 that evaluated interventions to facilitate SDM. The search strategy comprised three databases (EMBASE, PsycINFO, and Medline), reference tracking, citation tracking, and personal knowledge. Two independent reviewers screened titles and abstracts as well as full texts of potentially relevant records. We extracted the data using a pilot tested sheet, and we assessed the methodological quality of included studies using the Quality Assessment Tools from the U.S. National Institute of Health (NIH). Five completed studies and six study protocols fulfilled the inclusion criteria. The measure was used in a variety of health care settings, mainly in Europe, to evaluate several types of interventions. The reported mean sum scores ranged from 42 to 75 on a scale from 0 to 100. In four studies no significant change was detected in the mean-differences between main groups. In the fifth study the difference was small. Quality assessment revealed a high risk of bias in four of the five completed studies, while the study protocols received moderate quality ratings. We found a wide range of areas in which the SDM-Q-9 and SDM-Q-Doc were applied. In the future this review may help researchers decide whether the measure fits their purposes. Furthermore, the review revealed risk of bias in previous trials that used the measure, and may

Tracing river runoff and DOC over the East Siberian Shelf using in situ CDOM measurements

NASA Astrophysics Data System (ADS)

Pugach, Svetlana; Semiletov, Igor; Pipko, Irina

2010-05-01

The Great Siberian Rivers integrate meteorological and hydrological changes in their watersheds and play a significant role in the physical and biogeochemical regime of the Arctic Ocean through transport of fresh water (FW) and carbon into the sea. Since 1994, the Laboratory of Arctic Research POI in cooperation with the IARC UAF investigate the fresh water and carbon fluxes in the Siberian Arctic land-shelf system with the special emphasize in the East Siberian Arctic shelf (ESAS) which represents the widest and shallowest continental shelf in the World Ocean, yet it is still poorly explored. The East Siberian Sea is influenced by water exchange from the eastern Laptev Sea (where local shelf waters are diluted mostly by Lena River discharge) and by inflow of Pacific waters from the Chukchi Sea. This region is characterized by the highest rate of coastal erosion and significant volume of the riverine discharge and exhibits the largest gradients in all oceanographic parameters observed for the entire Arctic Ocean. Here we demonstrate a connection among Chromophoric (or Colored) Dissolved Organic Matter (CDOM) which represents the colored fraction of Dissolved Organic Carbon (DOC), salinity, and pCO2. Our data have documented strong linear correlations between salinity and CDOM in the near shore zone strongly influenced by riverine runoff. Correlation coefficient between CDOM and salinity in surface waters was equal to -0.94, -0.94 and -0.95 for surface water stations in September of 2003, 2004, and 2005, respectively. Combined analysis of CDOM and DOC data demonstrated a high degree of correlation between these parameters (r=0.96). Such close connection between these characteristics of waters in this region makes it possible to restore the distribution of DOC according to our original CDOM data of the profiling systems, such as CTD-Seabird equipped by WETStar CDOM fluorimeter. It is shown that the CDOM can be used as a conservative tracer to follow the transport and

Impact of Biodiesel Impurities on the Performance and Durability of DOC, DPF and SCR Technologies: Preprint

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

Williams, A.; McCormick, R.; Luecke, J.

2011-04-01

An accelerated durability test method determined the potential impact of biodiesel ash impurities, including engine testing with multiple diesel particulate filter substrate types, as well as diesel oxidation catalyst and selective catalyst reduction catalysts. The results showed no significant degradation in the thermo-mechanical properties of a DPF after exposure to 150,000-mile equivalent biodiesel ash and thermal aging. However, exposure to 435,000-mile equivalent aging resulted in a 69% decrease in thermal shock resistance. A decrease in DOC activity was seen after exposure to 150,000-mile equivalent aging, resulting in higher hydrocarbon slip and a reduction in NO2 formation. The SCR catalyst experiencedmore » a slight loss in activity after exposure to 435,000-mile equivalent aging. The SCR catalyst, placed downstream of the DPF and exposed to B20 exhaust suffered a 5% reduction in overall NOx conversion activity over the HDDT test cycle. It is estimated that the additional ash from 150,000 miles of biodiesel use would also result in a moderate increases in exhaust backpressure for a DPF. The results of this study suggest that long-term operation with B20 at the current specification limits for alkali and alkaline earth metal impurities will adversely impact the performance of DOC, DPF and SCR systems.« less

Non-target screening to trace ozonation transformation products in a wastewater treatment train including different post-treatments.

PubMed

Schollée, Jennifer E; Bourgin, Marc; von Gunten, Urs; McArdell, Christa S; Hollender, Juliane

2018-05-25

Ozonation and subsequent post-treatments are increasingly implemented in wastewater treatment plants (WWTPs) for enhanced micropollutant abatement. While this technology is effective, micropollutant oxidation leads to the formation of ozonation transformation products (OTPs). Target and suspect screening provide information about known parent compounds and known OTPs, but for a more comprehensive picture, non-target screening is needed. Here, sampling was conducted at a full-scale WWTP to investigate OTP formation at four ozone doses (2, 3, 4, and 5 mg/L, ranging from 0.3 to 1.0 gO 3 /gDOC) and subsequent changes during five post-treatment steps (i.e., sand filter, fixed bed bioreactor, moving bed bioreactor, and two granular activated carbon (GAC) filters, relatively fresh and pre-loaded). Samples were measured with online solid-phase extraction coupled to liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS) using electrospray ionization (ESI) in positive and negative modes. Existing non-target screening workflows were adapted to (1) examine the formation of potential OTPs at four ozone doses and (2) compare the removal of OTPs among five post-treatments. In (1), data processing included principal component analysis (PCA) and chemical knowledge on possible oxidation reactions to prioritize non-target features likely to be OTPs. Between 394 and 1328 unique potential OTPs were detected in positive ESI for the four ozone doses tested; between 12 and 324 unique potential OTPs were detected in negative ESI. At a specific ozone dose of 0.5 gO 3 /gDOC, 27 parent compounds were identified and were related to 69 non-target features selected as potential OTPs. Two OTPs were confirmed with reference standards (venlafaxine N-oxide and chlorothiazide); 34 other potential OTPs were in agreement with literature data and/or reaction mechanisms. In (2), hierarchical cluster analysis (HCA) was applied on profiles detected in positive ESI mode across the

Impact of Biodiesel Impurities on the Performance and Durability of DOC, DPF and SCR Technologies

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

Williams, A.; McCormick, R.; Luecke, J.

2011-06-01

It is estimated that operating continuously on a B20 fuel containing the current allowable ASTM specification limits for metal impurities in biodiesel could result in a doubling of ash exposure relative to lube-oil derived ash. The purpose of this study was to determine if a fuel containing metals at the ASTM limits could cause adverse impacts on the performance and durability of diesel emission control systems. An accelerated durability test method was developed to determine the potential impact of these biodiesel impurities. The test program included engine testing with multiple DPF substrate types as well as DOC and SCR catalysts.more » The results showed no significant degradation in the thermo-mechanical properties of cordierite, aluminum titanate, or silicon carbide DPFs after exposure to 150,000 mile equivalent biodiesel ash and thermal aging. However, exposure of a cordierite DPF to 435,000 mile equivalent aging resulted in a 69% decrease in the thermal shock resistance parameter. It is estimated that the additional ash from 150,000 miles of biodiesel use would also result in a moderate increases in exhaust backpressure for a DPF. A decrease in DOC activity was seen after exposure to 150,000 mile equivalent aging, resulting in higher HC slip and a reduction in NO{sub 2} formation. The metal-zeolite SCR catalyst experienced a slight loss in activity after exposure to 435,000 mile equivalent aging. This catalyst, placed downstream of the DPF, showed a 5% reduction in overall NOx conversion activity over the HDDT test cycle.« less

Temperature, DOC level and basin interactions explain the declining oxygen concentrations in the Bothnian Sea

NASA Astrophysics Data System (ADS)

Ahlgren, Joakim; Grimvall, Anders; Omstedt, Anders; Rolff, Carl; Wikner, Johan

2017-06-01

Hypoxia and oxygen deficient zones are expanding worldwide. To properly manage this deterioration of the marine environment, it is important to identify the causes of oxygen declines and the influence of anthropogenic activities. Here, we provide a study aiming to explain the declining oxygen levels in the deep waters of the Bothnian Sea over the past 20 years by investigating data from environmental monitoring programmes. The observed decline in oxygen concentrations in deep waters was found to be primarily a consequence of water temperature increase and partly caused by an increase in dissolved organic carbon (DOC) in the seawater (R2Adj. = 0.83) as well as inflow from the adjacent sea basin. As none of the tested eutrophication-related predictors were significant according to a stepwise multiple regression, a regional increase in nutrient inputs to the area is unlikely to explain a significant portion of the oxygen decline. Based on the findings of this study, preventing the development of anoxia in the deep water of the Bothnian Sea is dependent on the large-scale measures taken to reduce climate change. In addition, the reduction of the nutrient load to the Baltic Proper is required to counteract the development of hypoxic and phosphate-rich water in the Baltic Proper, which can form deep water in the Bothnian Sea. The relative importance of these sources to oxygen consumption is difficult to determine from the available data, but the results clearly demonstrate the importance of climate related factors such as temperature, DOC and inflow from adjacent basins for the oxygen status of the sea.

Removal of bulk dissolved organic carbon (DOC) and trace organic compounds by bank filtration and artificial recharge.

PubMed

Grünheid, Steffen; Amy, Gary; Jekel, Martin

2005-09-01

Bank filtration and artificial recharge provide an important drinking water source to the city of Berlin. Due to the practice of water recycling through a semi-closed urban water cycle, the introduction of effluent organic matter (EfOM) and persistent trace organic pollutants in the drinking water is of potential concern. In the work reported herein, the research objectives are to study the removal of bulk and trace organics at bank filtration and artificial recharge sites and to assess important factors of influence for the Berlin area. The monthly analytical program is comprised of dissolved organic carbon (DOC), UV absorbance (UVA254), liquid chromatography with organic carbon detection (LC-OCD), differentiated adsorbable organic halogens (AOX) and single organic compound analysis of a few model compounds. More than 1 year of monitoring was conducted on observation wells located along the flowpaths of the infiltrating water at two field sites that have different characteristics regarding redox conditions, travel time, and travel distance. Two transects are highlighted: one associated with a bank filtration site dominated by anoxic/anaerobic conditions with a travel time of up to 4-5 months, and another with an artificial recharge site dominated by aerobic conditions with a travel time of up to 50 days. It was found that redox conditions and travel time significantly influence the DOC degradation kinetics and the efficiency of AOX and trace compound removal.

Dutch Translation and Psychometric Testing of the 9-Item Shared Decision Making Questionnaire (SDM-Q-9) and Shared Decision Making Questionnaire-Physician Version (SDM-Q-Doc) in Primary and Secondary Care

PubMed Central

Rodenburg-Vandenbussche, Sumayah; Pieterse, Arwen H.; Kroonenberg, Pieter M.; Scholl, Isabelle; van der Weijden, Trudy; Luyten, Gre P. M.; Kruitwagen, Roy F. P. M.; den Ouden, Henk; Carlier, Ingrid V. E.; van Vliet, Irene M.; Zitman, Frans G.; Stiggelbout, Anne M.

2015-01-01

Purpose The SDM-Q-9 and SDM-Q-Doc measure patient and physician perception of the extent of shared decision making (SDM) during a physician-patient consultation. So far, no self-report instrument for SDM was available in Dutch, and validation of the scales in other languages has been limited. The aim of this study was to translate both scales into Dutch and assess their psychometric characteristics. Methods Participants were patients and their treating physicians (general practitioners and medical specialists). Patients (N = 182) rated their consultation using the SDM-Q-9, 43 physicians rated their consultations using the SDM-Q-Doc (N = 201). Acceptability, reliability (internal consistency), and the factorial structure of the instruments were determined. For convergent validity the CPSpost was used. Results Reliabilities of both scales were high (alpha SDM-Q-9 0.88; SDM-Q-Doc 0.87). The SDM-Q-9 and SDM-Q-Doc total scores correlated as expected with the CPSpost (SDM-Q-9: r = 0.29; SDM-Q-Doc: r = 0.48) and were significantly different between the CPSpost categories, with lowest mean scores when the physician made the decision alone. Principal Component Analyses showed a two-component model for each scale. A confirmatory factor analysis yielded a mediocre, but acceptable, one-factor model, if Item 1 was excluded; for both scales the best indices of fit were obtained for a one-factor solution, if both Items 1 and 9 were excluded. Conclusion The Dutch SDM-Q-9 and SDM-Q-Doc demonstrate good acceptance and reliability; they correlated as expected with the CPSpost and are suitable for use in Dutch primary and specialised care. Although the best model fit was found when excluding Items 1 and 9, we believe these items address important aspects of SDM. Therefore, also based on the coherence with theory and comparability with other studies, we suggest keeping all nine items of the scale. Further research on the SDM-concept in patients and physicians, in different clinical

“Docs 'n Drugs” - A System for Case-Oriented and Web-based Training in Medicine

PubMed Central

Martens, A.; Bernauer, J.

1999-01-01

The tutoring process of conventional case-oriented medical training systems can be characterised as either guided or unguided. In contrast to that, the aim of the system “Docs'n Drugs” is to distinguish between different levels of guidance. The author can realise the tutoring case either as a guided, a half guided or a unguided tutoring process. The system architecture distinguishes between an authoring system and a tutoring system. Fundaments of these are the tutoring process model and the case-based knowledge model. This structure allows the reuse of elements of existing tutoring cases. The tutoring cases can be realised in German and English.

Crystal Structures of Phd-Doc, HigA, and YeeU Establish Multiple Evolutionary Links between Microbial Growth-Regulating Toxin-Antitoxin Systems

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

Arbing, Mark A.; Handelman, Samuel K.; Kuzin, Alexandre P.

2010-09-27

Bacterial toxin-antitoxin (TA) systems serve a variety of physiological functions including regulation of cell growth and maintenance of foreign genetic elements. Sequence analyses suggest that TA families are linked by complex evolutionary relationships reflecting likely swapping of functional domains between different TA families. Our crystal structures of Phd-Doc from bacteriophage P1, the HigA antitoxin from Escherichia coli CFT073, and YeeU of the YeeUWV systems from E. coli K12 and Shigella flexneri confirm this inference and reveal additional, unanticipated structural relationships. The growth-regulating Doc toxin exhibits structural similarity to secreted virulence factors that are toxic for eukaryotic target cells. The Phdmore » antitoxin possesses the same fold as both the YefM and NE2111 antitoxins that inhibit structurally unrelated toxins. YeeU, which has an antitoxin-like activity that represses toxin expression, is structurally similar to the ribosome-interacting toxins YoeB and RelE. These observations suggest extensive functional exchanges have occurred between TA systems during bacterial evolution.« less

Promotion of health information access via Grateful Med and Loansome Doc: why isn't it working?

PubMed Central

Burnham, J F; Perry, M

1996-01-01

Information gathered from Grateful Med and Loansome Doc outreach projects, including one involving seven health centers in rural southwest Alabama, raises questions about the effectiveness of such programs. This paper presents a review of the literature on Grateful Med as well as of information access and usage behaviors of physicians, an overview of the Alabama project, and data from other projects. Analysis of the responses and observations of the researchers reveal some strategies for enhancing the outcomes of such projects and improving access to medical care literature by health care professionals at rural sites. PMID:8913552

Exploring the Impact of Online Peer-Editing Using Google Docs on EFL Learners' Academic Writing Skills: A Mixed Methods Study

ERIC Educational Resources Information Center

Ebadi, Saman; Rahimi, Masoud

2017-01-01

This article reports the results of a sequential explanatory mixed-methods approach to explore the impact of online peer-editing using Google Docs and peer-editing in a face-to-face classroom on EFL learners' academic writing skills. As the study adopted a quasi-experimental design, two intact classes, each with ten EFL learners, attending an…

Export and losses of blue carbon-derived particulate and dissolved organic carbon (POC and DOC) in blackwater river-dominated and particle-dominated estuaries

NASA Astrophysics Data System (ADS)

Arellano, A. R.; Bianchi, T. S.; Osburn, C. L.; D'Sa, E. J.; Oviedo Vargas, D.; Ward, N. D.; Joshi, I.; Ko, D. S.

2016-12-01

Globally, coastal blue carbon environments (wetlands, seagrass beds and mangroves) sequester an estimated 67-215 Tg C yr-1. While most blue carbon research has focused on carbon burial/stocks and habitat fragmentation of these communities, few studies have examined the export and loss of blue carbon sources of particulate organic matter (POM) and dissolved organic matter (DOM) to adjacent coastal waters. These shifts in losses of DOM and POM are also partly due to large-scale changes in land-use and climate change. Due to the complexity of vascular plant inputs to estuarine systems (e.g. terrestrial vs. blue carbon), being able to separate blue carbon sources of POM and DOM are critical. Here, we investigate the temporal variability of the abundance, sources and breakdown of particulate and dissolved organic carbon (POC and DOC) in particle-dominated (Barataria Bay) and blackwater river-dominated (Apalachicola Bay) estuaries in the northern Gulf of Mexico, using bulk carbon, dissolved lignin phenols, δ13C and dissolved CO2. The range of DOC:POC ratios for Barataria and Apalachicola bays were 0.5-3.1 and 2.3-57.0, respectively. δ13C-POC values were more depleted in Apalachicola (x̅=-27.3‰) compared to those in Barataria (x̅=-24.8‰), and C:N ratios were higher in Apalachicola (x̅=10.8) than in Barataria (x̅=9.3). Although there was no significant temporal variability with δ13C-POC in both systems, Barataria Bay had the highest POC (0.08-0.23 mM) and C:N (7.0-13.4) values during spring, when enhanced southerly winds likely resulted in higher resuspension and marsh erosion rates. Additionally, in Apalachicola, the lowest C:N values (6.2-16.1) were observed during the dry season when fluvial DOM inputs were minimal. The highest dissolved lignin phenol and DOC (0.10-2.98 mM) concentrations in Apalachicola occurred during the wet season, reflecting the importance of riverine inputs to this system. In particular, the Carabelle River plume region had C:V and S

The impact of electrocautery method on post-operative bleeding complications after non-newborn circumcision and revision circumcision.

PubMed

Harty, Niall J; Nelson, Caleb P; Cendron, Marc; Turner, Shaunna; Borer, Joseph G

2013-10-01

We evaluated post-operative bleeding complications in non-newborns following use of monopolar versus bipolar electrocautery for circumcision or revision circumcision. We retrospectively reviewed sequentially performed cases of circumcision and revision circumcision performed by nine pediatric urologists at our institution from 2005 to 2010. In order to incorporate both the monopolar and bipolar electrocautery experience for a single surgeon employing bipolar technique, sequential cases from 2002 to 2010 were reviewed. Variables assessed included age, procedure, method of electrocautery, skin approximation and dressing, and bleeding complications. 1810 patients that underwent either circumcision or revision circumcision were reviewed. Complete data was available for 1617 patients. Age at operation was a mean 3.7 ± 4.9 yrs and median 1.5 yrs. Return for bleeding complication for all surgeons, was 2/336 (0.6%) for bipolar and 28/1281 (2.2%) for monopolar (p = 0.0545). For the single surgeon using bipolar technique, returns were 2/336 (0.6%) for bipolar and 5/309 (1.6%) for monopolar (p = 0.2133). Returns per procedure type were 1/200 (0.5%) bipolar and 24/844 (2.8%) monopolar for primary circumcision (p = 0.0513), and 1/136 (0.7%) bipolar and 4/437 (0.9%) monopolar (p = 0.84) for revision. Four of 1617 (0.2%) patients returned to the operating room [4/1281 (0.3%) monopolar (p = 0.31)]. There was no difference in return to the operating room for circumcision versus revision. Return for bleeding complications after circumcision and revision circumcision occurred more frequently after monopolar electrocautery compared to bipolar. However, there was no significant difference between the two electrocautery methods. Either form of electrocautery appears to be effective for this common pediatric urologic procedure. Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

"Come on Guys, What Are We Really Trying to Say Here?" Using Google Docs to Develop Year 9 Pupils' Essay-Writing Skills

ERIC Educational Resources Information Center

Moonen, Lucy

2015-01-01

Lucy Moonen set out to explore whether collaborative writing in small groups, facilitated by the use of Google Docs, would help to sustain students' focus on essay writing as the development of an historical argument. She explains how she set up an essay on the League of Nationals as a collaborative task and demonstrates how the technology enabled…

Factors affecting the mobilization of DOC and metals in a peat soil under a warmer scenario

NASA Astrophysics Data System (ADS)

Carrera, Noela; Barreal, María. Esther; Briones, María. Jesús I.

2010-05-01

Most climate change models predict an increase of temperature of 3-5°C in Southern Europe by the end of this century (IPCC 2007). However, changes in summer precipitations are more uncertain, and although a decrease in rainfall inputs is forecasted by most models, the magnitude of this effect has not been assessed properly (Rowell & Jones 2006). Peatland areas are very sensitive to climate change. In Galicia they survive in upland areas where cold temperatures and continuous moisture supply allow their presence. Besides abiotic factors, alterations in soil fauna activities can also affect peat turnover. Among them, enchytraeids are usually the most numerous invertebrate group in these systems and both temperature and moisture content regulate their abundances and vertical distribution. Previous studies have demonstrated that changes in their populations associated to increasing temperatures can significantly affect metal mobilization, namely iron and aluminium, together with an important decline in the acidity of the soil solution, which possibly eliminates one of the critical mechanisms restricting DOC release (Carrera et al., 2009). In this study we investigated whether changes in water content of the peat soil and soil invertebrate activities associated to increasing temperatures could alter the mobilization rates of Fe and Al and in turn, DOC. 72 undisturbed soil cores (6 cm diameter x 10 cm deep) with their associated vegetation were taken from a blanket bog in Galicia (NW Spain). Back at the laboratory they were sliced horizontally into two layers, (0-5cm and 5-10cm) which were defaunated by means of a wet extraction. Thereafter, the two soil layers derived from the same core were introduced in each microcosm by placing them in their original position but separated by a 1 mm nylon mesh to allow the vertical movements of the organisms. Half of the experimental units were adjusted to the used moisture values observed in the field (80% SWC, H1), whereas in the

Stream Water, Carbon and Total Nitrogen Load Responses to a Simulated Emerald Ash Borer Infestation in Black Ash Dominated Headwater Wetlands

NASA Astrophysics Data System (ADS)

Van Grinsven, M. J.; Shannon, J.; Noh, N. J.; Kane, E. S.; Bolton, N. W.; Davis, J.; Wagenbrenner, J.; Sebestyen, S. D.; Kolka, R.; Pypker, T. G.

2017-12-01

The rapid and extensive expansion of emerald ash borer (EAB) is considered an important ecological and economic disturbance, and will likely affect critical ecosystem services associated with black ash wetlands. It is unknown how EAB-induced disturbance in wetlands dominated with black ash will impact stream water, dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) export dynamics. We hypothesized that loads of water, DOC and TDN exported from black ash wetlands would be elevated following an EAB-induced disturbance. Stream water, DOC and TDN loads exiting two black ash wetlands in headwater watersheds in Michigan were quantified over a four-year period, and were combined with wetland soil temperature and soil decomposition rate monitoring to better understand the biogeochemical implications of an EAB-induced disturbance. After a two-year baseline monitoring period, an EAB disturbance was simulated by felling (ash-cut) all black ash trees with diameters greater than 2.5-cm in one wetland. When compared to the unaltered control, stream water DOC and TDN concentrations exiting the ash-cut wetland were significantly larger by 39% and 38%, respectively during the post-treatment study period. The significantly elevated DOC and TDN concentrations were likely associated with the higher soil temperatures and increased rates of soil decomposition detected in the ash-cut site during the post-treatment period. No significant mean daily stream discharge differences were detected between treatments during the pre-treatment period, however the 0.46 mm d-1 mean daily stream discharge exiting the ash-cut wetland was significantly smaller than the 1.07 mm d-1 exiting the unaltered control during the post-treatment study period. The significantly smaller daily stream discharge in the ash-cut site likely contributed to the fact no significant differences between treatments for either mean daily DOC loads or TDN loads were detected during the post-treatment period

The spatial variability of water chemistry and DOC in bog pools: the importance of slope position, diurnal turnover and pool type

NASA Astrophysics Data System (ADS)

Holden, Joseph; Turner, Ed; Baird, Andy; Beadle, Jeannie; Billett, Mike; Brown, Lee; Chapman, Pippa; Dinsmore, Kerry; Dooling, Gemma; Grayson, Richard; Moody, Catherine; Gee, Clare

2017-04-01

We have previously shown that marine influence is an important factor controlling regional variability of pool water chemistry in blanket peatlands. Here we examine within-site controls on pool water chemistry. We surveyed natural and artificial (restoration sites) bog pools at blanket peatland sites in northern Scotland and Sweden. DOC, pH, conductivity, dissolved oxygen, temperature, cations, anions and absorbance spectra from 220-750nm were sampled. We sampled changes over time but also conducted intensive spatial surveys within individual pools and between pools on the same sampling days at individual study sites. Artificial pools had significantly greater DOC concentrations and different spectral absorbance characteristics when compared to natural pools at all sites studied. Within-pool variability in water chemistry tended to be small, even for very large pools ( 400 m2), except where pools had a layer of loose, mobile detritus on their beds. In these instances rapid changes took place between the overlying water column and the mobile sediment layer wherein dissolved oxygen concentrations dropped from values of around 12-10 mg/L to values less than 0.5 mg/L over just 2-3 cm of the depth profile. Such strong contrasts were not observed for pools which had a hard peat floor and which lacked a significant detritus layer. Strong diurnal turnover occurred within the pools on summer days, including within small, shallow pools (e.g. < 30 cm deep, 1 m2 area). For many pools on these summer days there was an evening spike in dissolved oxygen concentrations which originated at the surface and was then cycled downwards as the pool surface waters cooled. Slope location was a significant control on several pool water chemistry variables including pH and DOC concentration with accumulation (higher concentrations) in pools that were located further downslope in both natural and artificial pool systems. These processes have important implications for our interpretation of

Do medical complications impact long-term outcomes in prolonged disorders of consciousness?

PubMed

Estraneo, Anna; Loreto, Vincenzo; Masotta Psy, Orsola; Pascarella, Angelo; Trojano, Luigi

2018-05-25

to investigate medical complications (MC) occuring within 6 months post-injury in brain-injured patients with prolonged disorders of consciousness (DoC) and to evaluate impact of MC on mortality and long-term clinical outcomes. prospective observational cohort study. rehabilitation unit for acquired DoC. 194 patients with DoC (142 in vegetative state, 52 in minimally conscious state; traumatic etiology: 43, anoxic: 69, vascular: 82) consecutively admitted to a neurorehabilitation unit within 1-3 months after onset. not applicable. mortality and improvements in clinical diagnosis and functional disability level (assessed by Coma Recovery Scale-Revised and Disability Rating Scale) at 12, 24 and 36 months post-onset. within 6 months post-injury, more than 95% of patients (188/194) developed at least 1 MC and 73% of them (142) showed at least 1 severe MC. Respiratory and musculoskeletal-cutaneous MC were the most frequent, followed by endocrino-metabolic abnormalities. Follow-up, complete in 189/194 patients, showed that male sex and endocrine-metabolic MC were associated to higher risk for mortality at all timepoints. Older age, anoxic etiology, lower CRS-R total scores and diagnosis of vegetative state at study entry predicted no clinical and functional improvements at most timepoints, whereas epilepsy predicted no improvement in diagnosis at 24 months post-onset only. MC are very frequent in patients with DoC within at least 6 months after brain injury, regardless of clinical diagnosis, etiology and age. Endocrino-metabolic MC are independent predictors of mortality at all timepoints, whereas epilepsy predicted poor long-term outcome. Occurrence and severity of MC in patients with DoC call for long-term appropriate levels of care after the post-acute phase. Copyright © 2018. Published by Elsevier Inc.

Automatic publishing ISO 19115 metadata with PanMetaDocs using SensorML information

NASA Astrophysics Data System (ADS)

Stender, Vivien; Ulbricht, Damian; Schroeder, Matthias; Klump, Jens

2014-05-01

create ISO 19115 compliant metadata. The resulting metadata file is stored in the GFZ Potsdam data infrastructure. The publishing workflow for file based research datasets at GFZ Potsdam is based on the eSciDoc infrastructure, using PanMetaDocs (PMD) as the graphical user interface. PMD is a collaborative, metadata based data and information exchange platform [1]. Besides SWE, metadata are also syndicated by PMD through an OAI-PMH interface. In addition, metadata from other observatories, projects or sensors in TERENO can be accessed through the TERENO Northeast data portal. [1] http://meetingorganizer.copernicus.org/EGU2012/EGU2012-7058-2.pdf

Smoot Cosmology Group

Science.gov Websites

Opportunities Employment & Research Positions We currently have positions for: Post-Doctoral Fellows (post-docs) Graduate Student Reseach Assistants (GSRAs) Undergraduate Student Reseach Assistants

76 FR 9004 - Public Comment on Setting Achievement Levels in Writing

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-16

....wested.org/cs/naep/print/docs/naep/welcome.html , describes the process that will produce cutscores to....nagb.org Public and private individuals and organizations are invited to provide written comments and... the review and comment, the following materials are posted at http://www.wested.org/cs/naep/print/docs...

Effects of Land Use on Stable Carbon Isotopic Composition and Concentration of Dissolved Organic Carbon (DOC) and Dissolved Inorganic Carbon (DIC) in Southeastern US Piedmont Headwater Streams

EPA Science Inventory

Stable carbon isotopic composition (delta 13C) and concentrations of DOC and DIC were measured in stream water samples collected monthly in 15 headwater streams from an area with extensive poultry and cattle production and a rapidly growing human population. Linear regression te...

Documenting Climate Models and Simulations: the ES-DOC Ecosystem in Support of CMIP

NASA Astrophysics Data System (ADS)

Pascoe, C. L.; Guilyardi, E.

2017-12-01

The results of climate models are of increasing and widespread importance. No longer is climate model output of sole interest to climate scientists and researchers in the climate change impacts and adaptation fields. Now non-specialists such as government officials, policy-makers, and the general public, all have an increasing need to access climate model output and understand its implications. For this host of users, accurate and complete metadata (i.e., information about how and why the data were produced) is required to document the climate modeling results. Here we describe the ES-DOC community-govern project to collect and make available documentation of climate models and their simulations for the internationally coordinated modeling activity CMIP6 (Coupled Model Intercomparison Project, Phase 6). An overview of the underlying standards, key properties and features, the evolution from CMIP5, the underlying tools and workflows as well as what modelling groups should expect and how they should engage with the documentation of their contribution to CMIP6 is also presented.

Ageing and spatial reversal learning in humans: findings from a virtual water maze.

PubMed

Schoenfeld, R; Foreman, N; Leplow, B

2014-08-15

Deterioration in spatial memory with normal ageing is well accepted. Animal research has shown spatial reversal learning to be most vulnerable to pathological changes in the brain, but this has never been tested in humans. We studied ninety participants (52% females, 20-80 yrs) in a virtual water maze with a reversal learning procedure. Neuropsychological functioning, mood and personality were assessed to control moderator effects. For data analysis, participants were subdivided post hoc into groups aged 20-24, 25-34, 35-44, 45-64 and 65-80 yrs. Initial spatial learning occurred in all age groups but 65-80-yrs-olds never reached the level of younger participants. When tested for delayed recall of spatial memory, younger people frequented the target area but those over 65 yrs did not. In spatial reversal learning, age groups over 45 yrs were deficient and the 65-80-yrs-olds showed no evidence of reversal. Spatial measures were associated with neuropsychological functioning. Extraversion and measures of depression moderated the age effect on the learning index with older introverted and non-depressed individuals showing better results. Measures of anxiety moderated the age effect on reversal learning with older people having higher anxiety scores showing a preserved reversal learning capability. Results confirmed age to be a major factor in spatial tasks but further showed neuropsychological functioning, psycho-affective determinants and personality traits to be significant predictors of individual differences. Copyright © 2014 Elsevier B.V. All rights reserved.

Docs are buying in. Faltering hospitals are finding new life with physician-owners, but they may face challenges getting their facilities up to speed.

PubMed

Romano, Michael

2005-01-10

More physicians are stepping forward to buy their own hospitals, often aging or faltering facilities that need some special attention. Kamlesh Gosai, left, led a group that helped keep open Brownsville (Pa.) General Hospital, saving 250 jobs. Often such doc investors are confident they'll suceed in managing their fellow physicians. But others warn they'll face some tough decisions.

Enriching of surface water in nutrients and DOC on the area of drained Kuwasy Mire in North-East Poland

NASA Astrophysics Data System (ADS)

Jaszczyński, Jacek; Sapek, Andrzej

2010-05-01

Key words: peatlands, drained areas, surface water, nutrients and DOC in water The object of this study was fundamental mineral component concentration (N-NO3, N-NH4, PO4, K, Na, Ca, Mg, Cl, Fe) and dissolved organic carbon concentration (DOC) in surface water in artificial canal running across drained fen area. Also pH, electrical conductivity and abssorbance A280 in water samples were measured. The investigations were localized on the area of drained and agricultural used Kuwasy Mire, which are situated in the middle basin of Biebrza River, in North-East Poland. Currently on the object there is superiority of peat-moorsh soils with moorsh layers to 25 cm of depth. The bog depth is determined from 60 to 140 cm. The most of area is occupied by soils with 110-120 cm organic layer which are intensive agricultural used. Mean annual ground water table amounted 55 cm. On the distance of 8 km (about 1100-1200 ha catchment area) fen space is crossed by Kuwaski Canal collecting water from draining network above describing peatland. Surface water samples were collected every month in three constant point of canal: at entrance on peatland (upper point) in the middle part (middle point) and in border part of peatland (lower point). The study was carried out in 2001-2009. The aim of this study was to determine enriching of surface water in individual mineral and organic components during flowing across peatland area. Mean concentration in whole research period for all investigated components was higher together with flowing of water in canal across fen area. The higest increments of mean concentration between upper a lower point of canal was connected with phosphorous and amonia. The concentrations of these compounds were adequately 4,8 i 2,6 times higher in lower part of canal. Mean concentrations of remaining compounds were 2-14% higher in water in lower point in comparision to upper point of canal. In course of interflow through peatland pH of water was decreasing but

NNI Member Agencies Develop New Nanotechnology Signature Initiative | Nano

Science.gov Websites

; Job Info College, Grad School, and Post Doc Opportunities Nano & Emerging Tech Student Network Students For K-12 Teachers Associate Degrees, Certificates, & Job Info College, Grad School, and Post

Men older than 50 yrs are more likely to fall than women under similar conditions of health, body composition, and balance.

PubMed

Pereira, Catarina L N; Baptista, Fátima; Infante, Paulo

2013-12-01

The aim of this study was to analyze the contribution of sex to the occurrence of falls, accounting for comorbidities and differences in physical fitness. This was a cross-sectional study of 587 community-dwelling adults who were older than 50 yrs. Falls, comorbidities (number of diseases and physical impairments), and physical fitness (body composition, lower and upper body strength and flexibility, agility, aerobic endurance, and balance) were evaluated via questionnaires, bioimpedance, and Fullerton batteries, respectively. Compared with the men, the women presented a 10% higher fall prevalence, 1.7 more diseases/impairments, 10% more body fat, 26% less lean body mass, and poorer physical capacity (P < 0.05). Multivariate logistic regression revealed that male sex (odds ratio [OR], 2.723; 95% confidence interval [CI], 1.190-6.230) increased the likelihood of falling, after adjustment for comorbidities (OR, 1.213; 95% CI, 1.109-1.328), lean mass (OR, 0.958; 95% CI, 0.927-0.989), fat mass (OR, 1.053; 95% CI, 1.021-1.086), and balance (OR, 0.942; 95% CI, 0.914-0.971), which were the main risk factors of falls. Women are more susceptible to falling, presumably because they have poorer health and physical fitness than do men. However, when the values for comorbidities, lean and fat body mass, and balance were similar, the men demonstrated a higher probability of falling. Age is not a significant risk factor of falls under favorable conditions of health, body composition, and balance.

Characterization of Light Non-Methane Hydrocarbons, Surface Water DOC, and Aerosols over the Nordic Seas

NASA Astrophysics Data System (ADS)

Hudson, E. D.; Ariya, P. A.

2006-12-01

Whole air, size-fractionated marine aerosols, and surface ocean water DOC were sampled together during June-July 2004 on the Nordic seas, in order to explore factors leading to the formation of volatile organic compounds (VOCs) at the sea surface and their transfer to the atmosphere. High site-to-site variability in 19 non-methane hydrocarbon concentrations suggests highly variable, local sources for these compounds. Acetone, C5 and C6 hydrocarbons, and dimethylsulfide were identified in the seawater samples using solid-phase microextraction/GC-MS. The aerosols were analysed by SEM-EDX and contained primarily inorganic material (sea salt, marine sulfates, and carbonates) and little organic matter. However, a culturable bacterium was isolated from the large (9.9 - 18 μ m) fraction at one site, and identified as Micrococcus luteus. We will discuss the implication of these results on potential exchange processes at the ocean-atmosphere interface and the impact of bioaerosols in transferring marine organic carbon to atmospheric organic carbon.

Brazilian cross-cultural adaptation of the DocCom online module: communication for teamwork 1

PubMed Central

Borges, Tatiane Angélica Phelipini; Vannuchi, Marli Terezinha Oliveira; Grosseman, Suely; González, Alberto Durán

2017-01-01

ABSTRACT Objective: to carry out the cross-cultural adaptation of DocCom online module 38, which deals with teamwork communication into Portuguese for the Brazilian contexto. Method: the transcultural translation and adaptation were accomplished through initial translations, synthesis of the translations, evaluation and synthesis by a committee of experts, analysis by translators and back translation, pre-test with nurses and undergraduate students in Nursing, and analysis of the translators to obtain the final material. Results: in evaluation and synthesis of the translated version with the original version by the expert committee, the items obtained higher than 80% agreement. Few modifications were suggested according to the analysis by pretest participants. The final version was adequate to the proposed context and its purpose. Conclusion: it is believed that by making this new teaching-learning strategy of communication skills and competencies for teamwork available, it can be used systematically in undergraduate and postgraduate courses in the health area in Brazil in order to contribute to training professionals, and also towards making advances in this field.

Analysis of transthoracic impedance during real cardiac arrest defibrillation attempts in older children and adolescents: are stacked-shocks appropriate?

PubMed

Niles, Dana E; Nishisaki, Akira; Sutton, Robert M; Brunner, Sara; Stavland, Mette; Mahadevaiah, Shruthi; Meaney, Peter A; Maltese, Matthew R; Berg, Robert A; Nadkarni, Vinay M

2010-11-01

In 2005, the AHA changed the treatment recommendation for shockable rhythms from 3 transthoracic stacked-shocks to a single shock followed by immediate chest compressions. The stacked-shock recommendation was based on low first-shock efficacy of monophasic waveforms and the theoretical decrease in transthoracic impedance (TTI) following each shock. The objective of this study was to characterize TTI following biphasic defibrillation attempts in children ≥ 8 yrs during cardiac arrest to assess whether a stacked-shock approach may be appropriate to improve defibrillation success. TTI (Ohms (Ω)) was collected via standard anterior-apical defibrillator electrode pads during consecutive in-hospital cardiac arrest biphasic defibrillation attempts in children ≥ 8 yrs. Analytic data points for TTI were: 0.1s pre-shock (baseline); post-shock at 0.1, 0.5, 1.0, 1.5, and 2.0 s. TTI variables analyzed with descriptive summaries/paired t-test. p values < 0.05 considered statistically significant after correction for multiple comparisons. Analysis yielded 13 evaluable shock events during 5 cardiac arrests (mean age 14.3 ± 5 yrs, weight 47.4 ± 7.3 kg) between September 2006 and May 2009. Compared to 0.1s pre-shock baseline values (56.8 ± 23.4 Ω), TTI was significantly lower immediately 0.1s post-shock (55.2 ± 22.2 Ω, p = 0.003). Post-shock mean difference from baseline was 1.6 Ω at 0.1s (p = 0.015), 1.4 Ω at 0.5s (p = 0.019) 1.4 Ω at 1.0 s (p = 0.023), 1.1 Ω at 1.5 s (p = 0.028), and 0.95 Ω at 2.0 s (p = 0.096). Time to recharge our clinical defibrillators to standard biphasic shock dose was 2.80 ± 0.05 s. During cardiac arrests in children ≥ 8 yrs, TTI decreased after biphasic shocks, but the limited magnitude and duration of TTI changes suggest that stacked-shocks would not improve defibrillation success. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Effects of a pre-and post-workout protein-carbohydrate supplement in trained crossfit individuals.

PubMed

Outlaw, Jordan J; Wilborn, Colin D; Smith-Ryan, Abbie E; Hayward, Sara E; Urbina, Stacie L; Taylor, Lem W; Foster, Cliffa A

2014-01-01

The purpose was to assess effects of a pre- and a post-workout protein-carbohydrate supplement on CrossFit-specific performance and body composition. In an open label randomized study, 13 male and 16 female trained Crossfit participants (mean ± SD; age: 31.87 ± 7.61 yrs, weight: 78.68 ± 16.45 kg, percent body fat: 21.97 ± 9.02) were assessed at 0 and 6 weeks for body composition, VO2max, Wingate peak (WPP) and mean power (WMP), in addition to sport-specific workouts (WOD1: 500 m row, 40 wall balls, 30 push-ups, 20 box jumps, 10 thrusters for time; WOD2: 15 minutes to complete an 800 m run "buy in", followed by as many rounds as possible (AMRAP) of 5 burpees, 10 Kettlebell swings, 15 air squats). The supplement (SUP) group consisted of 19 g of a pre-workout drink (extracts of pomegranate, tart cherry, green and black tea) taken 30 minutes before and a post-workout protein (females: 20 g; males: 40 g) and carbohydrate (females: 40 g; males: 80 g) supplement consumed immediately after each workout. The control (CTL) group consumed only water one hour before or after workouts. Participants completed three (minimum) varied workouts per week at a CrossFit gym as typical to habitual training throughout the six week study. Data were analyzed by repeated measures ANOVA (p <0 .05), 95% Confidence Intervals, and Magnitude Inferences. There were no time × group interactions for body composition, WMP, or WOD1 based on ANOVA statistics. VO2MAX, WPP, and WOD2 results revealed that the pre/post supplements were likely beneficial after 95% Confidence Intervals and Magnitude Inferences analysis. The combination of proprietary supplements taken for 6 weeks may provide benefits during certain sport-specific performance in trained CrossFit athletes but not others.

CO2, CH4, and DOC Flux During Long Term Thaw of High Arctic Tundra

NASA Astrophysics Data System (ADS)

Stackhouse, B. T.; Vishnivetskaya, T. A.; Layton, A.; Bennett, P.; Mykytczuk, N.; Lau, C. M.; Whyte, L.; Onstott, T. C.

2013-12-01

rate of -196×12 (dark) nmol CH4 m-2 hr-1. Saturated cores occasionally acted as slight CH4 sources (17×17 nmol CH4 m-2 hr-1) but were generally found to still behave as CH4 sinks (maximum rate -93×56 nmol CH4 m-2 hr-1). Dissolved CH4 in the permafrost pore water immediately upon thaw was ~0.5 μM in all treatments, and remained at this concentration in the saturated cores. In in situ water saturation treatments, however, pore water CH4 concentrations decreased from 0.6×0.3 μM to 0.2×0.1 μM over the course of three weeks without release into the core headspace. This is likely due to aerobic methanotrophy, as the concentration of genomic sequences associated with methanotrophic bacteria was found to be 30 times greater in the upper 60 cm than in the permafrost. Sustained concentrations of CH4 in the deeper portion of saturated cores indicated that methanogenesis is occurring at depths near and below the permafrost table. Measurements of in situ DOC were 0.22×0.05 mmol L-1, whereas core DOC values increased to a maximum of >1.7 mmol L-1 (primarily acetate) during the course of the thawing experiment. These findings indicate that in a warming Arctic, even under various hydrological regimes, these soil types will be able to act as a sink of atmospheric CH4, a moderate source of CO2 and a potential source for DOC.

Early and Middle Pleistocene vegetation history of the Médoc region, southwest France

NASA Astrophysics Data System (ADS)

O'Brien, C. E.; Jones, R. L.

2003-09-01

Pleistocene deposits, together with their pollen, plant macrofossil, foraminiferal, dinoflagellate and coleopteran remains, from five sites along the Atlantic coast of the Médoc Peninsula are described and discussed. Sediments making up the Négade Formation are shown to have been laid down under either estuarine or lagoonal conditions when closed Quercus-Pinus-Tsuga canadensis regional woodland existed. Comparison with plant records from The Netherlands indicates that these deposits are most likely attributable to either the Early Pleistocene Bavel Interglacial (marine oxygen isotope stage (MIS) 31), or an interglacial of the Waalian (MIS 37-49) or Tiglian (MIS 63-79). In addition, clays assigned to the Argiles du Gurp sensu stricto, were similarly deposited in either an estuary or lagoon, which subsequently was cut off from the sea. A freshwater lake with vegetation dominated by Azolla filiculoides then developed. This was succeeded by reedswamp and an organic mud (termed Lignite in the corresponding French stratigraphical records) formed. Regional Quercus-Abies woodland was replaced by one with Pinus dominant and Pterocarya a minor component. Comparison with plant records from France and other parts of Europe suggest that the clays and organic mud might be correlated with the Holsteinian (Praclaux) Interglacial (MIS 11c). Copyright

Assessing quality and quantity of groundwater DOC in relation to plant export from different over-winter green-cover treatments in tillage farming systems

NASA Astrophysics Data System (ADS)

Premrov, Alina; Coxon, Catherine; Hackett, Richard; Richards, Karl

2010-05-01

The biogeochemistry of nitrogen is often connected to carbon and C/N dynamics. The dissolved organic carbon (DOC) electron donor availability can be related to groundwater denitrification (Buss, et al. 2005). Therefore groundwater nitrate attenuation processes are also frequently linked to carbon availability. In recent years the role of over-winter green cover in tillage farming has been studied extensively. Nevertheless further research on the biogeochemical effect of green cover on soil/sediment and groundwater quality is still needed. In particular plant roots are known to exude different types of organic compounds, but their role in groundwater quality has not been investigated in depth. According to Cannavo et al. (2004a,b), in addition to quantity, the quality of water-extractable soil organic matter (e.g. molecular size/weight) has also an important role for microbial activity. In this study we investigate the effect of over-winter green-cover on potential DOC export to shallow groundwater (2 - 5 m below ground level), located on tillage land in Oak Park, Carlow, Ireland. The experiment includes three over-winter green-cover treatments: natural green-cover, mustard and no-cover (sprayed with herbicide following harvest); and is underlain by a sand and gravel aquifer. The site is equipped with 4 shallow piezometers per treatment (total no. of piezometers is 20, including treatments and surrounding piezometers). In addition to monitoring the quantity of DOC concentrations in shallow groundwater under different green cover treatments over time, an attempt was made to evaluate the quality of dissolved organic matter in shallow groundwater using Excitation Emission Fluorescence Matrix (EEFM) profiles obtained from analyses performed on a Varian Fluorescence Spectrophotometer of a single batch of samples (from all 20 installed piezometers in September 2009). To evaluate the quality of dissolved organic matter in shallow groundwater, computation of the

Paradoxical aging in HIV: immune senescence of B Cells is most prominent in young age.

PubMed

Rinaldi, Stefano; Pallikkuth, Suresh; George, Varghese K; de Armas, Lesley R; Pahwa, Rajendra; Sanchez, Celeste M; Pallin, Maria Fernanda; Pan, Li; Cotugno, Nicola; Dickinson, Gordon; Rodriguez, Allan; Fischl, Margaret; Alcaide, Maria; Gonzalez, Louis; Palma, Paolo; Pahwa, Savita

2017-04-01

Combination antiretroviral therapies (cART)can lead to normal life expectancy in HIV-infected persons, and people aged >50 yrs represent the fastest growing HIV group. Although HIV and aging are independently associated with impaired humoral immunity, immune status in people aging with HIV is relatively unexplored. In this study influenza vaccination was used to probe age associated perturbations in the B cell compartment of HIV-negative "healthy controls" (HC) and virologically controlled HIV-infected participants on cART (HIV) (n=124), grouped by age as young (<40 yrs), middle-aged (40-59yrs) or old ( > 60 yrs). H1N1 antibody response at d21 post-vaccination correlated inversely with age in both HC and HIV. Immunophenotyping of cryopreserved PBMC demonstrated increased frequencies of double negative B cells and decreased plasmablasts in old compared to young HC. Remarkably, young HIV were different from young HC but similar to old HC in B cell phenotype, influenza specific spontaneous (d7) or memory (d21) antibody secreting cells. We conclude that B cell immune senescence is a prominent phenomenon in young HIV in comparison to young HC, but distinctions between old HIV and old HC are less evident though both groups manifest age-associated B cell dysfunction.

Paradoxical aging in HIV: immune senescence of B Cells is most prominent in young age

PubMed Central

George, Varghese K.; de Armas, Lesley R.; Pahwa, Rajendra; Sanchez, Celeste M.; Pallin, Maria Fernanda; Pan, Li; Cotugno, Nicola; Dickinson, Gordon; Rodriguez, Allan; Fischl, Margaret; Alcaide, Maria; Gonzalez, Louis; Palma, Paolo; Pahwa, Savita

2017-01-01

Combination antiretroviral therapies (cART) can lead to normal life expectancy in HIV-infected persons, and people aged >50 yrs represent the fastest growing HIV group. Although HIV and aging are independently associated with impaired humoral immunity, immune status in people aging with HIV is relatively unexplored. In this study influenza vaccination was used to probe age associated perturbations in the B cell compartment of HIV-negative “healthy controls” (HC) and virologically controlled HIV-infected participants on cART (HIV) (n=124), grouped by age as young (<40 yrs), middle-aged (40-59yrs) or old (≥60 yrs). H1N1 antibody response at d21 post-vaccination correlated inversely with age in both HC and HIV. Immunophenotyping of cryopreserved PBMC demonstrated increased frequencies of double negative B cells and decreased plasmablasts in old compared to young HC. Remarkably, young HIV were different from young HC but similar to old HC in B cell phenotype, influenza specific spontaneous (d7) or memory (d21) antibody secreting cells. We conclude that B cell immune senescence is a prominent phenomenon in young HIV in comparison to young HC, but distinctions between old HIV and old HC are less evident though both groups manifest age-associated B cell dysfunction. PMID:28448963

Evaluation of Fuel-Borne Sodium Effects on a DOC-DPF-SCR Heavy-Duty Engine Emission Control System: Simulation of Full-Useful Life

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

Lance, Michael; Wereszczak, Andrew; Toops, Todd J.

2016-04-05

For renewable fuels to displace petroleum, they must be compatible with emissions control devices. Pure biodiesel contains up to 5 ppm Na + K and 5 ppm Ca + Mg metals, which have the potential to degrade diesel emissions control systems. This study aims to address these concerns, identify deactivation mechanisms, and determine if a lower limit is needed. Accelerated aging of a production exhaust system was conducted on an engine test stand over 1,001 hr using B20 doped with 14 ppm Na. During the study, oxides of nitrogen (NOx) emissions exceeded the engine certification limit of 0.33 g/bhp-hr beforemore » the 435,000-mile requirement. Replacing aged diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR) devices with new degreened parts showed that each device contributed equally to the NOx increase. Following this systems-based evaluation, a detailed investigation of the individual components was completed. Na was determined to have minimal impact on DOC activity. For this system, it is estimated that B20-Na resulted in 50% more ash into the DPF. However, the Na did not diffuse into the cordierite DPF nor degrade its mechanical properties. The SCR degradation was found to be caused by a small amount of precious group metals contamination that increased ammonia oxidation, and lowered NOx reduction. Therefore, it was determined that the primary effect of Na in this study is through increased ash in the DPF rather than deactivation of the catalytic activity.« less

EMPLOYMENT OPPORTUNITIES IN NCEA

EPA Science Inventory

PostDoc Program">

Research Post-Doctoral Program Opportunities

Career Appointments:

Post retention and post/core shear bond strength of four post systems.

PubMed

Stockton, L W; Williams, P T; Clarke, C T

2000-01-01

As clinicians we continue to search for a post system which will give us maximum retention while maximizing resistance to root fracture. The introduction of several new post systems, with claims of high retentive and resistance to root fracture values, require that independent studies be performed to evaluate these claims. This study tested the tensile and shear dislodgment forces of four post designs that were luted into roots 10 mm apical of the CEJ. The Para Post Plus (P1) is a parallel-sided, passive design; the Para Post XT (P2) is a combination active/passive design; the Flexi-Post (F1) and the Flexi-Flange (F2) are active post designs. All systems tested were stainless steel. This study compared the test results of the four post designs for tensile and shear dislodgment. All mounted samples were loaded in tension until failure occurred. The tensile load was applied parallel to the long axis of the root, while the shear load was applied at 450 to the long axis of the root. The Flexi-Post (F1) was significantly different from the other three in the tensile test, however, the Para Post XT (P2) was significantly different to the other three in the shear test and had a better probability for survival in the Kaplan-Meier survival function test. Based on the results of this study, our recommendation is for the Para Post XT (P2).

Household exposure and animal-bite surveillance following human rabies detection in Southern Ghana

PubMed Central

Afakye, Kofi; Kenu, Ernest; Nyarko, Kofi Mensah; Johnson, Sherry Ama Mawuko; Wongnaah, Florence; Bonsu, George Kwame

2016-01-01

Introduction Rabies remains a neglected tropical zoonotic disease with 100% case fatality rate and estimated 6,000 global mortality annually, and yet vaccine preventable. In Ghana, rabies outbreaks receive poor response. We investigated rabies in a 5-year old boy to find the source of infection, identify exposed persons for post-exposure prophylaxis and describe animal-bite surveillance in Manya-Krobo District of Ghana. Methods We actively searched for cases and exposures by interviewing household members of the victim, schoolmates, and health professionals using WHO case definition, interview guide and checklist. We reviewed health and veterinary records and reports, and interviewed stakeholders. Descriptive data analyses were carried out and presented using tables and charts. Recorded responses were transcribed into thematic areas and analysed. Results Child had dog-bite at the wrist, and developed hyperactivity, hydrophobia and hyperventilation 2 months post bite. He was hospitalised and died from respiratory failure day 3 after admission. Thirty-three persons were exposed to rabies infectious material. Females were 66%, age-groups 5-15yrs and 30-59 yrs were 33.3% and 39.4% respectively. A third (11/33) were category II exposure by WHO classification and were recommended for post-exposure prophylaxis. Surveillance records showed ninety-two animal-bite cases were reported for past 12 months. Half were females, and 18-59yrs age-group was 43%. Surveillance data quality was poor. Conclusion Rabies remains a public health burden inGhana with domestic dog as reservoir of the virus and females more vulnerable to secondary exposures. Health education on rabies should be intensified, and robust animal-bite surveillance system put in place. PMID:28149437

Household exposure and animal-bite surveillance following human rabies detection in Southern Ghana.

PubMed

Afakye, Kofi; Kenu, Ernest; Nyarko, Kofi Mensah; Johnson, Sherry Ama Mawuko; Wongnaah, Florence; Bonsu, George Kwame

2016-01-01

Rabies remains a neglected tropical zoonotic disease with 100% case fatality rate and estimated 6,000 global mortality annually, and yet vaccine preventable. In Ghana, rabies outbreaks receive poor response. We investigated rabies in a 5-year old boy to find the source of infection, identify exposed persons for post-exposure prophylaxis and describe animal-bite surveillance in Manya-Krobo District of Ghana. We actively searched for cases and exposures by interviewing household members of the victim, schoolmates, and health professionals using WHO case definition, interview guide and checklist. We reviewed health and veterinary records and reports, and interviewed stakeholders. Descriptive data analyses were carried out and presented using tables and charts. Recorded responses were transcribed into thematic areas and analysed. Child had dog-bite at the wrist, and developed hyperactivity, hydrophobia and hyperventilation 2 months post bite. He was hospitalised and died from respiratory failure day 3 after admission. Thirty-three persons were exposed to rabies infectious material. Females were 66%, age-groups 5-15yrs and 30-59 yrs were 33.3% and 39.4% respectively. A third (11/33) were category II exposure by WHO classification and were recommended for post-exposure prophylaxis. Surveillance records showed ninety-two animal-bite cases were reported for past 12 months. Half were females, and 18-59yrs age-group was 43%. Surveillance data quality was poor. Rabies remains a public health burden inGhana with domestic dog as reservoir of the virus and females more vulnerable to secondary exposures. Health education on rabies should be intensified, and robust animal-bite surveillance system put in place.

Dissolved Organic Carbon and Natural Terrestrial Sequestration Potential in Volcanic Terrain, San Juan Mountains, Colorado

NASA Astrophysics Data System (ADS)

Yager, D. B.; Burchell, A.; Johnson, R. H.; Kugel, M.; Aiken, G.; Dick, R.

2009-12-01

represent an old and if undisturbed, stable carbon pool (500 -5,440 ± 40 yrs B.P). Undisturbed and reclaimed soils derived from propylitic bedrocks also exhibit high TOSC (13.5 - 25.6 wt%), C: N (27), arylsulfatase (338). This is consistent with earlier studies in which propylitic bedrocks were identified as having a high acid-neutralizing capacity (ANC). Observations at natural reclamation sites suggest “bio-geo-mimicry” techniques that use ANC rock plus other soil amendments (biochar, nutrients, mycorrhizea, seeding) may aid reclamation measures and support carbon sequestration. The data demonstrate that volcanic-hosted watersheds may exhibit both high TOSC and low DOC. This is attributed to: host rock-weathering release of nutrients important for soil productivity, ANC, formation of secondary mineral carbonates; development of intermediate soil aggregates and adsorption-enhancing clays that stabilize C and N, environmental factors such as climate, moisture retention, and land use. Future work will explore the potential of DOC flux as a proxy for NTS potential.

SMART DOCS: A New Patient-Centered Outcomes and Coordinated-Care Management Approach for the Future Practice of Sleep Medicine

PubMed Central

Kushida, Clete A.; Nichols, Deborah A.; Holmes, Tyson H.; Miller, Ric; Griffin, Kara; Cardell, Chia-Yu; Hyde, Pamela R.; Cohen, Elyse; Manber, Rachel; Walsh, James K.

2015-01-01

The practice of medicine is currently undergoing a transformation to become more efficient, cost-effective, and patient centered in its delivery of care. The aim of this article is to stimulate discussion within the sleep medicine community in addressing these needs by our approach as well as other approaches to sleep medicine care. The primary goals of the Sustainable Methods, Algorithms, and Research Tools for Delivering Optimal Care Study (SMART DOCS) are: (1) to introduce a new Patient-Centered Outcomes and Coordinated-Care Management (PCCM) approach for the future practice of sleep medicine, and (2) to test the PCCM approach against a Conventional Diagnostic and Treatment Outpatient Medical Care (CONV) approach in a randomized, two-arm, single-center, long-term, comparative effectiveness trial. The PCCM approach is integrated into a novel outpatient care delivery model for patients with sleep disorders that includes the latest technology, allowing providers to obtain more accurate and rapid diagnoses and to make evidence-based treatment recommendations, while simultaneously enabling patients to have access to personalized medical information and reports regarding their diagnosis and treatment so that they can make more informed health care decisions. Additionally, the PCCM approach facilitates better communication between patients, referring primary care physicians, sleep specialists, and allied health professionals so that providers can better assist patients in achieving their preferred outcomes. A total of 1,506 patients 18 y or older will be randomized to either the PCCM or CONV approach and will be followed for at least 1 y with endpoints of improved health care performance, better health, and cost control. Clinical Trials Registration: ClinicalTrials.gov Identifier: NCT02037438. Citation: Kushida CA, Nichols DA, Holmes TH, Miller R, Griffin K, Cardell CY, Hyde PR, Cohen E, Manber R, Walsh JK. SMART DOCS: a new patient-centered outcomes and coordinated

Chemical and sensory characterization of DOC red wines from Marche (Italy) related to vintage and grape cultivars.

PubMed

Boselli, Emanuele; Boulton, Roger B; Thorngate, John H; Frega, Natale G

2004-06-16

Monomeric phenols, color and copigmentation parameters, pigments with different chemical structure, tannin, glucose, fructose, glycerol, ethanol, and organic acids were determined in DOC red wines from Marche (Italy), obtained during three different vintages ranging from 1996 to 2000. The intensity of the bitter and astringent tastes of the wines was determined with panel tastings. Lacrima di Morro and Vernaccia di Serrapetrona (obtained from local cultivars) were different from Rosso Piceno, Rosso Piceno Superiore, and Rosso Conero (produced from different percentages of Sangiovese and Montepulciano). Vernaccia, a red, sweet, "spumante" wine, was an outlier. Lacrima showed a low tannin content, a high content of small pigments and phenols, and a high ratio of copigmented color, which persisted after 3 years of aging. The chemical determinations accounted for a high percentage of variability of measured panel astringency, copigmented color, and measured wine absorbance at 520 nm. It was not possible to create a predictive model for bitterness.

ENABLE 2017, the First EUROPEAN PhD and Post-Doc Symposium. Session 4: From Discovery to Cure: The Future of Therapeutics.

PubMed

Di Mauro, Gianmarco; Dondi, Ambra; Giangreco, Giovanni; Hogrebe, Alexander; Louer, Elja; Magistrati, Elisa; Mullari, Meeli; Turon, Gemma; Verdurmen, Wouter; Xicoy Cortada, Helena; Zivanovic, Sanja

2018-05-28

The EUROPEAN ACADEMY FOR BIOMEDICAL SCIENCE (ENABLE) is an initiative funded by the European Union Horizon 2020 program involving four renowned European Research Institutes (Institute for Research in Biomedicine-IRB Barcelona, Spain; Radboud Institute for Molecular Life Sciences-RIMLS, the Netherlands; Novo Nordisk Foundation Center for Protein Research-NNF CPR, Denmark; European School of Molecular Medicine-SEMM, Italy) and an innovative science communication agency (Scienseed). With the aim of promoting biomedical science of excellence in Europe, ENABLE organizes an annual three-day international event. This gathering includes a top-level scientific symposium bringing together leading scientists, PhD students, and post-doctoral fellows; career development activities supporting the progression of young researchers and fostering discussion about opportunities beyond the bench; and outreach activities stimulating the interaction between science and society. The first European PhD and Postdoc Symposium, entitled "Breaking Down Complexity: Innovative Models and Techniques in Biomedicine", was hosted by the vibrant city of Barcelona. The scientific program of the conference was focused on the most recent advances and applications of modern techniques and models in biomedical research and covered a wide range of topics, from synthetic biology to translational medicine. Overall, the event was a great success, with more than 200 attendees from all over Europe actively participating in the symposium by presenting their research and exchanging ideas with their peers and world-renowned scientists.

Carbon isotope analysis of dissolved organic carbon in fresh and saline (NaCl) water via continuous flow cavity ring-down spectroscopy following wet chemical oxidation

USGS Publications Warehouse

Conaway, Christopher; Thomas, Randal B.; Saad, Nabil; Thordsen, James J.; Kharaka, Yousif K.

2015-01-01

This work examines the performance and limitations of a wet chemical oxidation carbon analyser interfaced with a cavity ring-down spectrometer (WCO-CRDS) in a continuous flow (CF) configuration for measuring δ13C of dissolved organic carbon (δ13C-DOC) in natural water samples. Low-chloride matrix (<5 g Cl/L) DOC solutions were analysed with as little as 2.5 mg C/L in a 9 mL aliquot with a precision of 0.5 ‰. In high-chloride matrix (10–100 g Cl/L) DOC solutions, bias towards lighter δ13C-DOC was observed because of incomplete oxidation despite using high-concentration oxidant, extended reaction time, or post-wet chemical oxidation gas-phase combustion. However, through a combination of dilution, chloride removal, and increasing the oxidant:sample ratio, high-salinity samples with sufficient DOC (>22.5 µg C/aliquot) may be analysed. The WCO-CRDS approach requires more total carbon (µg C/aliquot) than conventional CF-isotope ratio mass spectrometer, but is nonetheless applicable to a wide range of DOC concentration and water types, including brackish water, produced water, and basinal brines.

Characterising DOC, DON and DOP flux in two contrasting lowland UK catchments: impacts of contrasting source character and connectivity on reach scale DOM signature

NASA Astrophysics Data System (ADS)

Yates, C. A.; Johnes, P.; Spencer, R. G.

2012-12-01

Riverine DOM is a significant component of C, N and P transport from source to sea. Research to date has focused on characterising DOC in upland and boreal moorland and forested catchments. Here we present the results of an investigation of DOM character and DOC, DON and DOP flux relative to C, N and P flux in two contrasting lowland UK catchments: the Wylye and Millersford Brook. Both were sampled at daily frequency at 3 sites over a 2 year period, (2010-11 WY, 2011-12 WY) with fluorescence EEMs and UV-Vis determined weekly. The Wylye is a Chalk catchment, underlain by a major aquifer. It has predominantly calcareous brown earth soils, intensive arable agriculture, scattered farms and riparian villages with a major settlement in the lower reaches of the river. There are few natural organic sources in the catchment and flows are baseflow dominated with a BFI of 0.93. DOC (NPOC) concentrations averaged 2.59 mg C/l in water year 2011-12, while Total N concentrations averaged 10.0 mg N/l, with DON averaging 0.9 mg N/l, and Total P concentrations averaged 0.18 mg/l with DOP averaging 0.026 mg/l. Millersford Brook drains peaty soils over glacial sands and clays, with moorland and forestry as the dominant land uses. Flows are dominated by overland and subsurface quick flow through with a BFI of 0.34. There is some low intensity grazing, no fertiliser use and no dwellings in the headwaters of the catchment. As a result nutrient concentrations are lower, but C flux is higher, with mean annual concentrations in WY 2011-12 of 0.93 mg TN/l, 0.051 mg TP/l, 8.83 mg DOC/l, 0.55 mg DON/l and 0.029 mg DOP/l. DOM character in Millersford Brook is comparable for that observed in other catchments with peaty soils and low acid neutralising capacity. The character of DOM varies along the length of the river, with HMW compounds dominating the signal in the headwaters, and LMW fluorescence intensities added to the signal in the lower reaches of the river, where septic tank effluent

Detailed behavioral assessment promotes accurate diagnosis in patients with disorders of consciousness

PubMed Central

Gilutz, Yael; Lazary, Avraham; Karpin, Hana; Vatine, Jean-Jacques; Misha, Tamar; Fortinsky, Hadassah; Sharon, Haggai

2015-01-01

Introduction: Assessing the awareness level in patients with disorders of consciousness (DOC) is made on the basis of exhibited behaviors. However, since motor signs of awareness (i.e., non-reflex motor responses) can be very subtle, differentiating the vegetative from minimally conscious states (which is in itself not clear-cut) is often challenging. Even the careful clinician relying on standardized scales may arrive at a wrong diagnosis. Aim: To report our experience in tackling this problem by using two in-house use assessment procedures developed at Reuth Rehabilitation Hospital, and demonstrate their clinical significance by reviewing two cases. Methods: (1) Reuth DOC Response Assessment (RDOC-RA) –administered in addition to the standardized tools, and emphasizes the importance of assessing a wide range of motor responses. In our experience, in some patients the only evidence for awareness may be a private specific movement that is not assessed by standard assessment tools. (2) Reuth DOC Periodic Intervention Model (RDOC-PIM) – current literature regarding assessment and diagnosis in DOC refers mostly to the acute phase of up to 1 year post injury. However, we have found major changes in responsiveness occurring 1 year or more post-injury in many patients. Therefore, we conduct periodic assessments at predetermined times points to ensure patients are not misdiagnosed or neurological changes overlooked. Results: In the first case the RDOC-RA promoted a more accurate diagnosis than that based on standardized scales alone. The second case shows how the RDOC-PIM allowed us to recognize late recovery and promoted reinstatement of treatment with good results. Conclusion: Adding a detailed periodic assessment of DOC patients to existing scales can yield critical information, promoting better diagnosis, treatment, and clinical outcomes. We discuss the implications of this observation for the future development and validation of assessment tools in DOC patients

Evaluation of the treatment of reverse osmosis concentrates from municipal wastewater reclamation by coagulation and granular activated carbon adsorption.

PubMed

Sun, Ying-Xue; Yang, Zhe; Ye, Tao; Shi, Na; Tian, Yuan

2016-07-01

Reverse osmosis concentrate (ROC) from municipal wastewater reclamation reverse osmosis (mWRRO) contains elevated concentrations of contaminants which pose potential risks to aquatic environment. The treatment of ROC from an mWRRO using granular activated carbon (GAC) combined pretreatment of coagulation was optimized and evaluated. Among the three coagulants tested, ferric chloride (FeCl3) presented relatively higher DOC removal efficiency than polyaluminium chloride and lime at the same dosage and coagulation conditions. The removal efficiency of DOC, genotoxicity, and antiestrogenic activity concentration of the ROC could achieve 16.9, 18.9, and 39.7 %, respectively, by FeCl3 coagulation (with FeCl3 dosage of 180.22 mg/L), which can hardly reduce UV254 and genotoxicity normalized by DOC of the DOM with MW <5 kDa. However, the post-GAC adsorption column (with filtration velocity of 5.7 m/h, breakthrough point adsorption capacity of 0.22 mg DOC/g GAC) exhibited excellent removal efficiency on the dominant DOM fraction of MW <5 kDa in the ROC. The removal efficiency of DOC, UV254, and TDS in the ROC was up to 91.8, 96, and 76.5 %, respectively, by the FeCl3 coagulation and post-GAC adsorption. Also, the DOM with both genotoxicity and antiestrogenic activity were completely eliminated by the GAC adsorption. The results suggest that GAC adsorption combined pretreatment of FeCl3 coagulation as an efficient method to control organics, genotoxicity, and antiestrogenic activity in the ROC from mWRRO system.

Acute toxicity of heavy metals for benthic epiphytic foraminifera Pararotalia spinigera (Le Calvez) and influence of seaweed-derived DOC

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

Bresler, V.; Yanko, V.

1995-10-01

The acute toxicity of cadmium, copper, and mercury to the benthic epiphytic foraminiferan Pararotalia spinigera (Le Calvez) was investigated using seven different vital cytophysiological and cytochemical methods. The ability to enzymatically hydrolyze the fluorogenic substrates fluorescein diacetate or fluorescein dibutyrate was the most sensitive method of LC50 value determination. The LC50 (24-h) values for cadmium, copper, and mercury determined by this assay with fluorescein diacetate was 0.56, 1.4, and 0.07 {micro}M, respectively. The content of seaweed-derived dissolved organic carbon (DOC), measured by absorbance at 436 nm, produced a dramatic increase of LC50 values for the heavy metals in a dose-dependentmore » manner. ``Intact`` epiphytic foraminifera attached to seaweeds are less sensitive to acute toxicity of cadmium, copper, and mercury than are ``detached`` foraminifera.« less

Prediction of Primary Care Depression Outcomes at Six Months: Validation of DOC-6 ©.

PubMed

Angstman, Kurt B; Garrison, Gregory M; Gonzalez, Cesar A; Cozine, Daniel W; Cozine, Elizabeth W; Katzelnick, David J

2017-01-01

The goal of this study was to develop and validate an assessment tool for adult primary care patients diagnosed with depression to determine predictive probability of clinical outcomes at 6 months. We retrospectively reviewed 3096 adult patients enrolled in collaborative care management (CCM) for depression. Patients enrolled on or before December 31, 2013, served as the training set (n = 2525), whereas those enrolled after that date served as the preliminary validation set (n = 571). Six variables (2 demographic and 4 clinical) were statistically significant in determining clinical outcomes. Using the validation data set, the remission classifier produced the receiver operating characteristics (ROC) curve with a c-statistic or area under the curve (AUC) of 0.62 with predicted probabilities than ranged from 14.5% to 79.1%, with a median of 50.6%. The persistent depressive symptoms (PDS) classifier produced an ROC curve with a c-statistic or AUC of 0.67 and predicted probabilities that ranged from 5.5% to 73.1%, with a median of 23.5%. We were able to identify readily available variables and then validated these in the prediction of depression remission and PDS at 6 months. The DOC-6 tool may be used to predict which patients may be at risk for worse outcomes. © Copyright 2017 by the American Board of Family Medicine.

You are only as old as you sound: auditory aftereffects in vocal age perception.

PubMed

Zäske, Romi; Schweinberger, Stefan R

2011-12-01

High-level adaptation not only biases the perception of faces, but also causes transient distortions in auditory perception of non-linguistic voice information about gender, identity, and emotional intonation. Here we report a novel auditory aftereffect in perceiving vocal age: age estimates were elevated in age-morphed test voices when preceded by adaptor voices of young speakers (∼20 yrs), compared to old adaptor voices (∼70 yrs). This vocal age aftereffect (VAAE) complements a recently reported face aftereffect (Schweinberger et al., 2010) and points to selective neuronal coding of vocal age. Intriguingly, post-adaptation assessment revealed that VAAEs could persist for minutes after adaptation, although reduced in magnitude. As an important qualification, VAAEs during post-adaptation were modulated by gender congruency between speaker and listener. For both male and female listeners, VAAEs were much reduced for test voices of opposite gender. Overall, this study establishes a new auditory aftereffect in the perception of vocal age. We offer a tentative sociobiological explanation for the differential, gender-dependent recovery from vocal age adaptation. Copyright © 2011 Elsevier B.V. All rights reserved.

Evaluation of fuel-borne sodium effects on a DOC-DPF-SCR heavy-duty engine emission control system: Simulation of full-useful life

DOE PAGES

Lance, Michael J.; Wereszczak, Andrew A; Toops, Todd J.; ...

2016-10-17

Here we report that for renewable fuels to displace petroleum, they must be compatible with emissions control devices. Pure biodiesel contains up to 5 ppm Na + K and 5 ppm Ca + Mg metals, which have the potential to degrade diesel emissions control systems. This study aims to address these concerns, identify deactivation mechanisms, and determine if a lower limit is needed. Accelerated aging of a production exhaust system was conducted on an engine test stand over 1001 h using 20% biodiesel blended into ultra-low sulfur diesel (B20) doped with 14 ppm Na. This Na level is equivalent tomore » exposure to Na at the uppermost expected B100 value in a B20 blend for the system full-useful life. During the study, NOx emissions exceeded the engine certification limit of 0.33 g/bhp-hr before the 435,000-mile requirement. Replacing aged diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR) devices with new degreened parts showed that each device contributed equally to the NOx increase. Following this systems-based evaluation, a detailed investigation of the individual components was completed. Na was determined to have minimal impact on DOC activity. For this system, it is estimated that B20-Na resulted in 50% more ash into the DPF. However, the Na did not diffuse into the cordierite DPF nor degrade its mechanical properties. The SCR degradation was found to be caused by a small amount of precious group metals (PGM) contamination that increased NH3 oxidation, and lowered NOx reduction. Therefore, we determined that the primary effect of Na in this study is through increased ash in the DPF rather than deactivation of the catalytic activity.« less

Evaluation of fuel-borne sodium effects on a DOC-DPF-SCR heavy-duty engine emission control system: Simulation of full-useful life

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

Lance, Michael J.; Wereszczak, Andrew A; Toops, Todd J.

Here we report that for renewable fuels to displace petroleum, they must be compatible with emissions control devices. Pure biodiesel contains up to 5 ppm Na + K and 5 ppm Ca + Mg metals, which have the potential to degrade diesel emissions control systems. This study aims to address these concerns, identify deactivation mechanisms, and determine if a lower limit is needed. Accelerated aging of a production exhaust system was conducted on an engine test stand over 1001 h using 20% biodiesel blended into ultra-low sulfur diesel (B20) doped with 14 ppm Na. This Na level is equivalent tomore » exposure to Na at the uppermost expected B100 value in a B20 blend for the system full-useful life. During the study, NOx emissions exceeded the engine certification limit of 0.33 g/bhp-hr before the 435,000-mile requirement. Replacing aged diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR) devices with new degreened parts showed that each device contributed equally to the NOx increase. Following this systems-based evaluation, a detailed investigation of the individual components was completed. Na was determined to have minimal impact on DOC activity. For this system, it is estimated that B20-Na resulted in 50% more ash into the DPF. However, the Na did not diffuse into the cordierite DPF nor degrade its mechanical properties. The SCR degradation was found to be caused by a small amount of precious group metals (PGM) contamination that increased NH3 oxidation, and lowered NOx reduction. Therefore, we determined that the primary effect of Na in this study is through increased ash in the DPF rather than deactivation of the catalytic activity.« less

The "Post-Post Period" and Environmental Education Research

ERIC Educational Resources Information Center

McKenzie, Marcia

2005-01-01

Described as "post-experimental" and of the "post-post period," the current moment in social science research is typified by multi-voiced texts, researcher reflexivity, cultural criticism, and experimental works; characteristics in keeping with post-structurally informed understandings of social science research as contingent, evolving and messy.…

Predictors of post-partum damage accrual in systemic lupus erythematosus: data from LUMINA, a multiethnic US cohort (XXXVIII).

PubMed

Andrade, R M; McGwin, G; Alarcón, G S; Sanchez, M L; Bertoli, A M; Fernández, M; Fessler, B J; Apte, M; Arango, A M; Bastian, H M; Vilá, L M; Reveille, J D

2006-11-01

To determine the impact of pregnancy on systemic lupus erythematosus (SLE) outcome. SLE patients, age >or=16 yrs, disease duration yrs at enrolment in LUMINA, a multiethnic cohort (Hispanics, African-Americans and Caucasians), were studied. The first pregnancy after SLE diagnosis was examined. A good pregnancy outcome was a full-term delivery; an adverse outcome was a miscarriage, abortion, premature birth or stillbirth. Dependent variables were disease activity (Systemic Lupus Activity Measure-Revised, SLAM-R) and damage accrual [Systemic Lupus International Collaborating Clinics (SLICC) Damage Index, SDI]. Differences in these variables between the visit immediately prior to, and the first visit after, pregnancy and their relationship with pregnancy outcome were examined. Damage accrual due to pregnancy exposure was examined by a case-crossover design. Sixty-three SLE women from all ethnic groups were included. The mean (S.D.) age and disease duration at pregnancy outcome were 27.6 (6.5) yrs and 18.3 (22.5) months, respectively. Adverse pregnancy outcomes occurred in 76.2% women. The SLAM-R and SDI scores were statistically different after pregnancy (P = 0.050 and P < 0.001, respectively); the SDI score was independent of pregnancy outcome but strongly associated with pregnancy duration (P = 0.006), disease activity (P = 0.001), damage prior to pregnancy (P < 0.001) and total disease duration (P = 0.039) by multivariable analyses. Exposure to pregnancy itself did not impact on damage accrual in the case-crossover analyses of 142 patients (17 pregnancy exposures) (OR = 1.25; 95% CI 0.336-4.655; P = 0.480). Pregnancy duration, total disease duration, disease activity and damage immediately prior to pregnancy decisively impact on damage accrual after pregnancy in patients with SLE.

Effect of beta-alanine supplementation on the onset of blood lactate accumulation (OBLA) during treadmill running: Pre/post 2 treatment experimental design.

PubMed

Jordan, Thomas; Lukaszuk, Judith; Misic, Mark; Umoren, Josephine

2010-05-19

beta-Alanine (betaA) has been shown to improve performance during cycling. This study was the first to examine the effects of betaA supplementation on the onset of blood lactate accumulation (OBLA) during incremental treadmill running. Seventeen recreationally-active men (mean +/- SE 24.9 +/- 4.7 yrs, 180.6 +/- 8.9 cm, 79.25 +/- 9.0 kg) participated in this randomized, double-blind, placebo-controlled pre/post test 2-treatment experimental design. Subjects participated in two incremental treadmill tests before and after 28 days of supplementation with either betaA (6.0 g.d-1)(betaA, n = 8) or an equivalent dose of Maltodextrin as the Placebo (PL, n = 9). Heart rate, percent heart rate maximum (%HRmax), %VO2max@OBLA (4.0 mmol.L-1 blood lactate concentration) and VO2max (L.min-1) were determined for each treadmill test. Friedman test was used to determine within group differences; and Mann-Whitney was used to determine between group differences for pre and post values (p < 0.05). The betaA group experienced a significant rightward shift in HR@OBLA beats.min-1 (p < 0.01) pre/post (161.6 +/- 19.2 to 173.6 +/- 9.9) but remained unchanged in the PL group (166.8 +/- 15.8 to 169.6 +/- 16.1). The %HRmax@OBLA increased (p < 0.05) pre/post in the betaA group (83.0% +/- 9.7 to 88.6% +/- 3.7) versus no change in the PL group (86.3 +/- % 4.8 to 87.9% +/- 7.2). The %VO2max@OBLA increased (p < 0.05) in the betaA group pre/post (69.1 +/- 11.0 to 75.6 +/- 10.7) but remained unchanged in the PL group (73.3 +/- 7.3 to 74.3 +/- 7.3). VO2max (L.min-1) decreased (p < 0.01) in the betaA group pre/post (4.57 +/- 0.8 to 4.31 +/- 0.8) versus no change in the PL group (4.04 +/- 0.7 to 4.18 +/- 0.8). Body mass kg increased (p < 0.05) in the betaA group pre/post (77.9 +/- 9.0 to 78.3 +/- 9.3) while the PL group was unchanged (80.6 +/- 9.1 to 80.4 +/- 9.0). betaA supplementation for 28 days enhanced sub-maximal endurance performance by delaying OBLA. However, betaA supplemented individuals had a

The role of wildfires and forest succession in stream biogeochemistry within the continuous permafrost zone of Central Siberia

NASA Astrophysics Data System (ADS)

Prokushkin, Anatoly

2016-04-01

Wildfires transform boreal and subarctic forested landscapes leading to the changes in organic matter and inorganic nutrient turnover in terrestrial ecosystems. To get an insight to the fire effect on C fluxes and general hydrochemical characteristics of streams draining continuous permafrost terrains of Central Siberian Plateau (64o N 100o E), we have selected the chronosequence of basins (n = 17) which were severely affected by fires (>80% of basin area) in the time range from 1 to 116 years ago. Stream waters were sampled continuously during frost free seasons (May-September) of 2006-2015. Four streams have been equipped with water level, temperature and conductivity probes for continuous monitoring. The strongest negative effect of wildfires on dissolved organic carbon (DOC) concentrations in streams has occurred right after a fire event, and minimum mean annual concentrations of DOC appeared between 15 and 20 years elapsed after a fire. The most pronounced decrease in DOC concentrations during an annual cycle found in freshet period (May-June) and summer-fall storm events: differences of DOC concentrations among "intact" (>100 years after fire) and recent fire basins (<6 years) reached as much as 2-fold. Less differentiation among basins appears under lowflow conditions, as DOC-depleted solutes from deeper soil layers become dominating in stream flow. Following the post-fire forest recovery, the seasonal mean DOC concentrations in streams demonstrated linear growth at the rate of ca. 0.11 mgC/l/a and approached the initial values already after ca. 60 years after fire disturbance. An opposite trend (i.e. increasing load to streams after fire impact) was observed for dissolved inorganic carbon, major anions and cations. Sulfate was found to be a good tracer of fire affect as increased 200-fold in stream waters right after a fire and steady decreased at the rate [SO42-] = 3.65 x (year after fire)^-0.75 as terrestrial ecosystems were recovering after a fire. For

K- and L-edge X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) determination of differential orbital covalency (DOC) of transition metal sites

DOE PAGES

Baker, Michael L.; Mara, Michael W.; Yan, James J.; ...

2017-02-09

Continual advancements in the development of synchrotron radiation sources have resulted in X-ray based spectroscopic techniques capable of probing the electronic and structural properties of numerous systems. This review gives an overview of the application of metal K-edge and L-edge X-ray absorption spectroscopy (XAS), as well as Kα resonant inelastic X-ray scattering (RIXS), to the study of electronic structure in transition metal sites with emphasis on experimentally quantifying 3d orbital covalency. The specific sensitivities of K-edge XAS, L-edge XAS, and RIXS are discussed emphasizing the complementary nature of the methods. L-edge XAS and RIXS are sensitive to mixing between 3dmore » orbitals and ligand valence orbitals, and to the differential orbital covalency (DOC), that is, the difference in the covalencies for different symmetry sets of the d orbitals. Both L-edge XAS and RIXS are highly sensitive to and enable separation of σ and π donor bonding and π back bonding contributions to bonding. Applying ligand field multiplet simulations, including charge transfer via valence bond configuration interactions, DOC can be obtained for direct comparison with density functional theory calculations and to understand chemical trends. Here, the application of RIXS as a probe of frontier molecular orbitals in a heme enzyme demonstrates the potential of this method for the study of metal sites in highly covalent coordination sites in bioinorganic chemistry.« less

K- and L-edge X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) determination of differential orbital covalency (DOC) of transition metal sites

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

Baker, Michael L.; Mara, Michael W.; Yan, James J.

Continual advancements in the development of synchrotron radiation sources have resulted in X-ray based spectroscopic techniques capable of probing the electronic and structural properties of numerous systems. This review gives an overview of the application of metal K-edge and L-edge X-ray absorption spectroscopy (XAS), as well as Kα resonant inelastic X-ray scattering (RIXS), to the study of electronic structure in transition metal sites with emphasis on experimentally quantifying 3d orbital covalency. The specific sensitivities of K-edge XAS, L-edge XAS, and RIXS are discussed emphasizing the complementary nature of the methods. L-edge XAS and RIXS are sensitive to mixing between 3dmore » orbitals and ligand valence orbitals, and to the differential orbital covalency (DOC), that is, the difference in the covalencies for different symmetry sets of the d orbitals. Both L-edge XAS and RIXS are highly sensitive to and enable separation of σ and π donor bonding and π back bonding contributions to bonding. Applying ligand field multiplet simulations, including charge transfer via valence bond configuration interactions, DOC can be obtained for direct comparison with density functional theory calculations and to understand chemical trends. Here, the application of RIXS as a probe of frontier molecular orbitals in a heme enzyme demonstrates the potential of this method for the study of metal sites in highly covalent coordination sites in bioinorganic chemistry.« less

The short mean length of stay of post-emergency geriatric units is associated with the rate of early readmission in frail elderly.

PubMed

Traissac, Thalie; Videau, Marie-Neige; Bourdil, Marie-José; Bourdel-Marchasson, Isabelle; Salles, Nathalie

2011-06-01

Specific postemergency short-stay geriatric units may decrease length of hospital stay, functional decline, and early readmission rates. The aim of this study was to evaluate risk factors of early rehospitalization in a shortstay geriatric unit. This study was a prospective observational study comprising over one year patients aged over 75 years, admitted to the post-emergency short-stay geriatric unit (Hôpital Saint André, Bordeaux, France) and discharged home. Socio-demographic data, length of hospital stay, and a standardized geriatric assessment were collected for all patients. One month after home discharge, patients were followed-up by phone, and the hospital readmission rate was calculated. descriptive, unvaried and multivariate analyses were carried out. A total of 476 patients were included in this study (mean age 86.5±6 yrs; 154 men, 322 women). Mean length of stay in the post-emergency short-stay geriatric unit was 6.3±2.7 days, and a total of 68 (14.3%) patients were readmitted within one month after home discharge. The readmission rate was associated with a diagnosis of delirium (Odds Ratio (OR) 1.9; 95% CI 1.1-3.3; p=0.02), mean length of stay exceeding 6 days (OR 1.9, 95% CI 1.1-3.5; p=0.02), and decision of home discharge (OR 2.4; 95% CI 1.4-4.1; p=0.002). Short mean lengths of stay were not considered as a risk factor for readmissions within one month, even in frail, dependent, hospitalized elderly persons.

Contributions of algae to GPP and DOC production in an Alaskan fen: effects of historical water table manipulations on ecosystem responses to a natural flood.

PubMed

Wyatt, Kevin H; Turetsky, Merritt R; Rober, Allison R; Giroldo, Danilo; Kane, Evan S; Stevenson, R Jan

2012-07-01

The role of algae in the metabolism of northern peatlands is largely unknown, as is how algae will respond to the rapid climate change being experienced in this region. In this study, we examined patterns in algal productivity, nutrients, and dissolved organic carbon (DOC) during an uncharacteristically wet summer in an Alaskan rich fen. Our sampling was conducted in three large-scale experimental plots where water table position had been manipulated (including both drying and wetting plots and a control) for the previous 4 years. This study allowed us to explore how much ecosystem memory of the antecedent water table manipulations governed algal responses to natural flooding. Despite no differences in water table position between the manipulated plots at the time of sampling, algal primary productivity was consistently higher in the lowered water table plot compared to the control or raised water table plots. In all plots, algal productivity peaked immediately following seasonal maxima in nutrient concentrations. We found a positive relationship between algal productivity and water-column DOC concentrations (r (2) = 0.85, P < 0.001). Using these data, we estimate that algae released approximately 19% of fixed carbon into the water column. Algal exudates were extremely labile in biodegradability assays, decreasing by more than 55% within the first 24 h of incubation. We suggest that algae can be an important component of the photosynthetic community in boreal peatlands and may become increasingly important for energy flow in a more variable climate with more intense droughts and flooding.

Addressing the expected survival benefit for clinical trial design in metastatic castration-resistant prostate cancer: Sensitivity analysis of randomized trials.

PubMed

Massari, Francesco; Modena, Alessandra; Ciccarese, Chiara; Pilotto, Sara; Maines, Francesca; Bracarda, Sergio; Sperduti, Isabella; Giannarelli, Diana; Carlini, Paolo; Santini, Daniele; Tortora, Giampaolo; Porta, Camillo; Bria, Emilio

2016-02-01

We performed a sensitivity analysis, cumulating all randomized clinical trials (RCTs) in which patients with metastatic castration-resistant prostate cancer (mCRPC) received systemic therapy, to evaluate if the comparison of RCTs may drive to biased survival estimations. An overall survival (OS) significant difference according to therapeutic strategy was more likely be determined in RCTs evaluating hormonal drugs versus those studies testing immunotherapy, chemotherapy or other strategies. With regard to control arm, an OS significant effect was found for placebo-controlled trials versus studies comparing experimental treatment with active therapies. Finally, regarding to docetaxel (DOC) timing, the OS benefit was more likely to be proved in Post-DOC setting in comparison with DOC and Pre-DOC. These data suggest that clinical trial design should take into account new benchmarks such as the type of treatment strategy, the choice of the comparator and the phase of the disease in relation to the administration of standard chemotherapy. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Simulated climate change impact on summer dissolved organic carbon release from peat and surface vegetation: implications for drinking water treatment.

PubMed

Ritson, Jonathan P; Bell, Michael; Graham, Nigel J D; Templeton, Michael R; Brazier, Richard E; Verhoef, Anne; Freeman, Chris; Clark, Joanna M

2014-12-15

Uncertainty regarding changes in dissolved organic carbon (DOC) quantity and quality has created interest in managing peatlands for their ecosystem services such as drinking water provision. The evidence base for such interventions is, however, sometimes contradictory. We performed a laboratory climate manipulation using a factorial design on two dominant peatland vegetation types (Calluna vulgaris and Sphagnum Spp.) and a peat soil collected from a drinking water catchment in Exmoor National Park, UK. Temperature and rainfall were set to represent baseline and future conditions under the UKCP09 2080s high emissions scenario for July and August. DOC leachate then underwent standard water treatment of coagulation/flocculation before chlorination. C. vulgaris leached more DOC than Sphagnum Spp. (7.17 versus 3.00 mg g(-1)) with higher specific ultraviolet (SUVA) values and a greater sensitivity to climate, leaching more DOC under simulated future conditions. The peat soil leached less DOC (0.37 mg g(-1)) than the vegetation and was less sensitive to climate. Differences in coagulation removal efficiency between the DOC sources appears to be driven by relative solubilisation of protein-like DOC, observed through the fluorescence peak C/T. Post-coagulation only differences between vegetation types were detected for the regulated disinfection by-products (DBPs), suggesting climate change influence at this scale can be removed via coagulation. Our results suggest current biodiversity restoration programmes to encourage Sphagnum Spp. will result in lower DOC concentrations and SUVA values, particularly with warmer and drier summers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Submersible UV-Vis Spectroscopy for Quantifying Streamwater Organic Carbon Dynamics: Implementation and Challenges before and after Forest Harvest in a Headwater Stream

PubMed Central

Jollymore, Ashlee; Johnson, Mark S.; Hawthorne, Iain

2012-01-01

Organic material, including total and dissolved organic carbon (DOC), is ubiquitous within aquatic ecosystems, playing a variety of important and diverse biogeochemical and ecological roles. Determining how land-use changes affect DOC concentrations and bioavailability within aquatic ecosystems is an important means of evaluating the effects on ecological productivity and biogeochemical cycling. This paper presents a methodology case study looking at the deployment of a submersible UV-Vis absorbance spectrophotometer (UV-Vis spectro∷lyzer model, s∷can, Vienna, Austria) to determine stream organic carbon dynamics within a headwater catchment located near Campbell River (British Columbia, Canada). Field-based absorbance measurements of DOC were made before and after forest harvest, highlighting the advantages of high temporal resolution compared to traditional grab sampling and laboratory measurements. Details of remote deployment are described. High-frequency DOC data is explored by resampling the 30 min time series with a range of resampling time intervals (from daily to weekly time steps). DOC export was calculated for three months from the post-harvest data and resampled time series, showing that sampling frequency has a profound effect on total DOC export. DOC exports derived from weekly measurements were found to underestimate export by as much as 30% compared to DOC export calculated from high-frequency data. Additionally, the importance of the ability to remotely monitor the system through a recently deployed wireless connection is emphasized by examining causes of prior data losses, and how such losses may be prevented through the ability to react when environmental or power disturbances cause system interruption and data loss. PMID:22666002

Submersible UV-Vis spectroscopy for quantifying streamwater organic carbon dynamics: implementation and challenges before and after forest harvest in a headwater stream.

PubMed

Jollymore, Ashlee; Johnson, Mark S; Hawthorne, Iain

2012-01-01

Organic material, including total and dissolved organic carbon (DOC), is ubiquitous within aquatic ecosystems, playing a variety of important and diverse biogeochemical and ecological roles. Determining how land-use changes affect DOC concentrations and bioavailability within aquatic ecosystems is an important means of evaluating the effects on ecological productivity and biogeochemical cycling. This paper presents a methodology case study looking at the deployment of a submersible UV-Vis absorbance spectrophotometer (UV-Vis spectro::lyzer model, s::can, Vienna, Austria) to determine stream organic carbon dynamics within a headwater catchment located near Campbell River (British Columbia, Canada). Field-based absorbance measurements of DOC were made before and after forest harvest, highlighting the advantages of high temporal resolution compared to traditional grab sampling and laboratory measurements. Details of remote deployment are described. High-frequency DOC data is explored by resampling the 30 min time series with a range of resampling time intervals (from daily to weekly time steps). DOC export was calculated for three months from the post-harvest data and resampled time series, showing that sampling frequency has a profound effect on total DOC export. DOC exports derived from weekly measurements were found to underestimate export by as much as 30% compared to DOC export calculated from high-frequency data. Additionally, the importance of the ability to remotely monitor the system through a recently deployed wireless connection is emphasized by examining causes of prior data losses, and how such losses may be prevented through the ability to react when environmental or power disturbances cause system interruption and data loss.

Dose-response relationships between physical activity, social participation, and health-related quality of life in colorectal cancer survivors

PubMed Central

Thraen-Borowski, Keith M.; Trentham-Dietz, Amy; Edwards, Dorothy Farrar; Koltyn, Kelli F.; Colbert, Lisa H.

2013-01-01

Purpose To examine the relationships between physical activity (PA), social participation and health-related quality of life (HQOL) in older, long-term colorectal cancer survivors. Methods Male and female colorectal cancer survivors (n=1768), aged ≥ 65 yrs and ≥5 yrs post-diagnosis, completed surveys on their current PA, social participation, HQOL, health history and relevant covariates. ANCOVA was used to evaluate the cross-sectional relationship between PA and social participation with the SF-36 subscales, as well as the physical component summary score (PCS) and mental health component summary score (MCS). Results The final analytic sample (n= 832) was 81.5 ± 5.8 yrs and 8.2 ±1.7 yrs post-diagnosis (mean±SD). Meeting the current recommendation of 150 min/wk of PA was associated with higher PCS (p=<0.001) but not MCS (p=0.30). Engaging in any social participation, vs. none, was associated with MCS (p=0.003), but not PCS (p=0.13). There was a dose-response relationship between moderate-vigorous intensity PA and PCS (ptrend =<0.001). Light intensity PA was not associated with either summary score after adjustment for moderate-vigorous PA (p>0.05), but in survivors performing no higher intensity PA, it was associated with both (p<0.01, p=0.02, respectively). Participants reporting greater amounts of both planned exercise and non-exercise PA had significantly higher PCS (ptrend=<0.01, ptrend <0.01, respectively). Individuals participating in greater weekly hours of social participation had higher PCS and MCS (ptrend =<0.05) than those participating in less. Conclusions Among older, long-term colorectal cancer survivors, PA is related to their physical health, while social participation is predominantly related to their mental health. Implications for cancer survivors Older colorectal cancer survivors who participate socially and are engaged in PA, even non-exercise and light intensity activities, have higher levels of physical and mental health. PMID:23546822

An Experiment Comparing Lexical and Statistical Methods for Extracting MeSH Terms from Clinical Free Text

PubMed Central

Cooper, Gregory F.; Miller, Randolph A.

1998-01-01

Abstract Objective: A primary goal of the University of Pittsburgh's 1990-94 UMLS-sponsored effort was to develop and evaluate PostDoc (a lexical indexing system) and Pindex (a statistical indexing system) comparatively, and then in combination as a hybrid system. Each system takes as input a portion of the free text from a narrative part of a patient's electronic medical record and returns a list of suggested MeSH terms to use in formulating a Medline search that includes concepts in the text. This paper describes the systems and reports an evaluation. The intent is for this evaluation to serve as a step toward the eventual realization of systems that assist healthcare personnel in using the electronic medical record to construct patient-specific searches of Medline. Design: The authors tested the performances of PostDoc, Pindex, and a hybrid system, using text taken from randomly selected clinical records, which were stratified to include six radiology reports, six pathology reports, and six discharge summaries. They identified concepts in the clinical records that might conceivably be used in performing a patient-specific Medline search. Each system was given the free text of each record as an input. The extent to which a system-derived list of MeSH terms captured the relevant concepts in these documents was determined based on blinded assessments by the authors. Results: PostDoc output a mean of approximately 19 MeSH terms per report, which included about 40% of the relevant report concepts. Pindex output a mean of approximately 57 terms per report and captured about 45% of the relevant report concepts. A hybrid system captured approximately 66% of the relevant concepts and output about 71 terms per report. Conclusion: The outputs of PostDoc and Pindex are complementary in capturing MeSH terms from clinical free text. The results suggest possible approaches to reduce the number of terms output while maintaining the percentage of terms captured, including the

77 FR 38297 - Revised Document Posted: NIOSH List of Antineoplastic and Other Hazardous Drugs in Healthcare...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-27

.../2012-150 . Background: The NIOSH Alert: NIOSH published Preventing Occupational Exposures to.../docs/2004-165/ ). Appendix A of this Alert defined hazardous drugs and provided a list of drugs that...

Post clamp

NASA Technical Reports Server (NTRS)

Ramsey, John K. (Inventor); Meyn, Erwin H. (Inventor)

1990-01-01

A pair of spaced collars are mounted at right angles on a clamp body by retaining rings which enable the collars to rotate with respect to the clamp body. Mounting posts extend through aligned holes in the collars and clamp body. Each collar can be clamped onto the inserted post while the clamp body remains free to rotate about the post and collar. The clamp body is selectively clamped onto each post.

Correspondence between fiber post and drill dimensions for post canal preparation.

PubMed

Portigliatti, Ricardo Pablo; Tumini, José Luis; Bertoldi Hepburn, Alejandro Daniel; Aromando, Romina Flavia; Olmos, Jorge Lorenzo

2017-12-01

To compare fiber posts of several calibers and trademarks to their corresponding root canal preparation drills. Three widely used endodontic post brands and their drills were evaluated: Exacto, ParaPost Taper Lux, and Macro-Lock Illusion X-RO. Fiber posts and drills were microphotographed with a scanning electron microscope and images were analyzed using ImageJ image processing software. Fiber post diameter on apical extreme (Pd0), fiber post diameter at 5 mm from the apical extreme (Pd5), drill diameter on apical extreme (Dd0) and drill diameter at 5 mm from the apical extreme (Dd5) were analyzed. The data were statistically analyzed using student t-test. Exacto posts 0.5 showed larger dimensions than their corresponding drills (P< 0.05) at Pd0. Macro-Lock posts showed no significant differences vs. their drills at Pd0 in any of the studied groups. ParaPost drills 4.5, 5 and 5.5 were statistically significantly larger than their posts at Dd0 (P< 0.05). Exacto posts 0.5 and 1 showed larger dimensions than their drills measured at Pd5 (P< 0.05). Exacto posts number 2 showed smaller calibers than their corresponding drills at Pd5 (P< 0.05). Macro-Lock drills number 4 and ParaPost drills number 5 were larger than their posts at Dd5 (P< 0.05). Poor spatial correspondence between post and drill dimensions can adversely affect the film thickness of the resin cement, diminishing bond strength due to polymerization shrinkage. The lack of correspondence in size between posts and drills may lead to the formation of empty chambers between the post and endodontic obturation with excessive luting cement thickness, thus inducing critical C-Factor stresses.

Post-traumatic Stress Disorder Post Partum

PubMed Central

Schwab, W.; Marth, C.; Bergant, A. M.

2012-01-01

Traumatic birth experiences may lead to serious psychological impairment. Recent studies show that a considerable number of women can develop post-traumatic stress disorder (PTSD), in some cases in a subsyndromal form. Until now, the possibility that postpartum psychological symptoms might be a continuum of a pre-existing disorder in pregnancy has rarely been considered. This study therefore aimed to evaluate the proportion of women who develop post-traumatic stress disorder as a result of childbirth. Materials and Methods: 56 multiparous women were recruited for the study. The diagnosis of PTSD was made according to the criteria for psychological disorders in the DSM-IV (Diagnostics and Statistical Manual of Mental Disorders). The data were collected in structured interviews in the 30th to 38th week of gestation and in the 6th week post partum. Results: Of the 56 women participating, 52 (93 %) completed the survey. Uncontrolled results showed that 21.15 % of the multiparous women met the full diagnostic PTSD criteria in the 6th week post partum. After the exclusion of all cases already characterised by all criteria or a subsyndromal form of PTSD caused by previous traumatisation, the PTSD rate was below 8 % at 6 weeks postpartum (= incidence rate of PTSD post partum). Conclusions: The present study is the first prospective longitudinal study to demonstrate the occurrence of full criteria PTSD in multiparous women as a result of childbirth after having excluded pre-existing PTSD. The results of our study show a high prevalence rate of PTSD during pregnancy. A number of women report all aspects of post-traumatic stress disorder as a result of childbirth. PMID:25253905

NRC/AMRMC Resident Research Associateship Program

DTIC Science & Technology

2017-04-01

final report. The productivity of these Associates is listed in the technical report. 15. SUBJECT TERMS- Associateship program, post -doc, awards 16...granting institutions in the United States; 4) posting announcements on internet job sites, electronic newsletters and professional society websites; 5...implemented in the testing and evaluation of medical countermeasures. SCHOLARLY PRODUCTIVITY ARTICLES - PEER REVIEWED Bixler, Sandra L; Bearss, Jeremy J

Breaking the Conflict Cycle: Incorporating Stability Operations into a Cycle Framework

DTIC Science & Technology

2008-06-13

conflict cycle – early warning, conflict prevention, conflict management , and post-conflict reconstruction retain all the basic principles of FM 3-0...accepted in the field of international relations and is instrumental for understanding how conflict prevention, conflict management , and post-conflict...Conflict Prevention and Conflict Management in Northeast Asia. Retrieved 25 February 2009 from www.silkroadstudies.org/new/docs/beijing

78 FR 28732 - Revisions to Electric Quarterly Report Filing Process; Availability of Draft XML Schema

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-16

... posting CSV file samples. Order No. 770 revised the process for filing EQRs. Pursuant to Order No. 770, one of the new processes for filing allows EQRs to be filed using an XML file. The XML schema that is needed to file EQRs in this manner is now posted on the Commission's Web site at http://www.ferc.gov/docs...

Hurricane Katrina Impact on Water Quality in the East Pearl River, Mississippi

NASA Astrophysics Data System (ADS)

Shiller, A. M.; Shim, M.; Guo, L.; Bianchi, T. S.; Smith, R. W.; Duan, S.

2010-12-01

Hurricanes and other intense storms have previously been reported to cause short term changes in surface water quality. We examined the water quality of the East Pearl River in southern Mississippi both before and after Hurricane Katrina caused extensive damage to the watershed in 2005. Our post-storm sampling began two months after the hurricane, and thus we missed any immediate short-term consequences. However, sampling over the following two years allowed us to examine whether damage to watershed resulted in significant longer term effects on water quality. Interpretation of the time series data is complicated by the natural seasonal and climatic variability of the system. Thus, we utilized property-property plots as well as empirical relationships to compare pre- and post-storm water quality. Based on the variability of our empirical relationships, we estimate that to within 20%, the hurricane-induced vegetative destruction within this river basin has not changed the concentrations of DOC, POC, SPM, pH, or dissolved Fe. Nor has the quality of the DOC, as inferred from lignin-phenol analysis and the Fe-DOC relationship, been significantly changed either. This may be partly due to the slow degradation of woody materials that occurs only over a period of a few years, even in the sub-tropical climate of this region. Also, transport of DOC material from the land, through the soils, and into the river is not always instantaneous because DOC may stay in soils for a long time. Our work can be examined in the context of other research focused on hurricane effects on different time scales. For instance, shorter term hurricane influences, such as immediate flooding, can cause concurrent, short-lived water quality changes. Likewise, if increased hurricane activity (as might result from climate change) results in permanent landscape or ecosystem changes, then significant long-term water quality changes might be expected.

ENABLE 2017, the First EUROPEAN PhD and Post-Doc Symposium. Session 3: In Vitro to In Vivo: Modeling Life in 3D.

PubMed

Di Mauro, Gianmarco; Dondi, Ambra; Giangreco, Giovanni; Hogrebe, Alexander; Louer, Elja; Magistrati, Elisa; Mullari, Meeli; Turon, Gemma; Verdurmen, Wouter; Cortada, Helena Xicoy; Zivanovic, Sanja

2018-05-22

The EUROPEAN ACADEMY FOR BIOMEDICAL SCIENCE (ENABLE) is an initiative funded by the European Union Horizon 2020 program involving four renowned European research institutes (Institute for Research in Biomedicine-IRB Barcelona, Spain; Radboud Institute for Molecular Life Sciences-RIMLS, the Netherlands; Novo Nordisk Foundation Center for Protein Research-NNF CPR, Denmark; European School of Molecular Medicine-SEMM, Italy) and an innovative science communication agency (Scienseed). With the aim to promote biomedical science of excellence in Europe, ENABLE organizes an annual three-day international event. This gathering includes a top-level scientific symposium bringing together leading scientists, PhD students, and post-doctoral fellows; career development activities supporting the progression of young researchers and fostering discussion about opportunities beyond the bench; outreach activities stimulating the interaction between science and society. The first European PhD and Postdoc Symposium, entitled "Breaking Down Complexity: Innovative models and techniques in biomedicine", was hosted by the vibrant city of Barcelona. The scientific program of the conference was focused on the most recent advances and applications of modern techniques and models in biomedical research and covered a wide range of topics, from synthetic biology to translational medicine. Overall, the event was a great success, with more than 200 attendees from all over Europe actively participating in the symposium by presenting their research and exchanging ideas with their peers and world-renowned scientists.

Effects of dietary protein on the composition of weight loss in post-menopausal women.

PubMed

Gordon, M M; Bopp, M J; Easter, L; Miller, G D; Lyles, M F; Houston, D K; Nicklas, B J; Kritchevsky, S B

2008-10-01

To determine whether a hypocaloric diet higher in protein can prevent the loss of lean mass that is commonly associated with weight loss. An intervention study comparing a hypocaloric diet moderately high in protein to one lower in protein. Study measurements were taken at the Wake Forest University General Clinical Research Center (GCRC) and Geriatric Research Center (GRC). Twenty-four post-menopausal, obese women (mean age = 58 +/- 6.6 yrs; mean BMI = 33.0 +/- 3.6 kg/m2). Two 20-week hypocaloric diets (both reduced by 2800 kcal/wk) were compared: one maintaining dietary protein intake at 30% of total energy intake (1.2-1.5 g/kg/d; HI PROT), and the other maintaining dietary protein intake at 15% of total energy (0.5-0.7 g/kg/d; LO PROT). The GCRC metabolic kitchen provided lunch and dinner meals which the women picked up 3 days per week and ate outside of the clinic. Body composition, including total body mass, total lean mass, total fat mass, and appendicular lean mass, assessed by dual energy x-ray absorptiometry, was measured before and after the diet interventions. The HI PROT group lost 8.4 +/- 4.5 kg and the LO PROT group lost 11.4 +/- 3.8 kg of body weight (p = 0.11). The mean percentage of total mass lost as lean mass was 17.3% +/- 27.8% and 37.5% +/- 14.6%, respectively (p = 0.03). Maintaining adequate protein intake may reduce lean mass losses associated with voluntary weight loss in older women.

Primary succession seen through the shifted patterns of plant traits and soil macrofauna above/under-ground activity, a different ecological perspective towards post mining sites

NASA Astrophysics Data System (ADS)

Moradi, Jabbar; Mudrak, Ondrej; Frouz, Jan

2016-04-01

Using of trait distribution is becoming a promising field of ecology. Community weighted mean (CWM) values, in this regard, can summarize the shifts in the mean trait values within communities via environmental selection for a specific functional trait. Although traits have been widely used to describe relationships between plants and environmental variables, they are less used in study of interactions with other trophical levels. In 2013, we conducted a study to see the effect of plant community traits on soil and soil macrofauna epigeic/endogeic activity. We used sites of 10, 18, 28 and 55 years old in a succession sequence located at Sokolov post-mining site, Czech Republic. In each site we studied bare, grassy and woody patches. Vegetation traits, namely plant forms (i.e. grass, forb, legume, shrub and tree), canopy height, LDMC (leaf dry matter content), seed mass, and presence/absence of taproot during the whole life cycle were identified in 1-m×1-m quadrates. Soil fauna samples were collected from the same patches. Four patches were sampled in each plot and patch type. Fauna were extracted with a Tullgren apparatus, identified to family and counted. Their numbers were expressed per m2. CWM values of plan traits and faunal surface activity were calculated using the FD package in R. The computed values were transferred afterwards to CANOCO for further analyses. The effect of patches and age on dependent variables was determined with two-way ANOVAs. The higher LDMC in grassy and woody patches, particularly its correlation with 28 yrs site, can be related to higher reported P levels in 28 yrs site in specific, and generally higher nutrient return and C accumulation in vegetated sites. The absence of taproot in vegetated patches and 28 yrs site can be because of more competition with other species. It seems that the correlation between seed mass with oldest site and legume form is, roughly, a result of the change in community composition from forbs and grasses

Testing the Pairs-Reflection Model with X-Ray Spectral Variability and X-Ray Properties of Complete Samples of Radio-Selected BL Lacertae Objects

NASA Astrophysics Data System (ADS)

Urry, C. Megan

1997-01-01

This grant was awarded to Dr. C. Megan Urry of the Space Telescope Science Institute in response to two successful ADP proposals to use archival Ginga and Rosat X-ray data for 'Testing the Pairs-Reflection model with X-Ray Spectral Variability' (in collaboration with Paola Grandi, now at the University of Rome) and 'X-Ray Properties of Complete Samples of Radio-Selected BL Lacertae Objects' (in collaboration with then-graduate student Rita Sambruna, now a post-doc at Goddard Space Flight Center). In addition, post-docs Joseph Pesce and Elena Pian, and graduate student Matthew O'Dowd, have worked on several aspects of these projects. The grant was originally awarded on 3/01/94; this report covers the full period, through May 1997. We have completed our project on the X-ray properties of radio-selected BL Lacs.

Assessment of the Dynamic Insulin Secretion and Sensitivity Test (DISST) Pre and Post Gastric bypass Surgery.

PubMed

Wilson, John; Docherty, Paul; Stubbs, Richard; Chase, J Geoffrey; Krebs, Jeremy

2018-06-11

To compare the dynamic insulin secretion and sensitivity test (DISST) with the euglycaemic clamp in individuals undergoing open Roux-en-Y gastric bypass (RYGB) surgery prior-to and one month after surgery. Insulin sensitivity in individuals with obesity undergoing RYGB was studied with DISST and a euglycaemic hyperinsulinaemic clamp. Eleven participants, including nine females, mean(SD) age 51.2(12.1)yrs, with a preoperative BMI of 48.7(9.5)kg/m 2 were studied. Weight reduced from a mean(SD) of 133.8(29.8)kg to 123.8(28.9)kg post-surgery (p<0.001). The mean(SD) insulin sensitivity index (ISI-DISST) was 3.07×10 -4 (2.18)L.pmol -1 .min -1 preoperatively and 2.36 ×10 -4 (0.78)L.pmol -1 .min -1 postoperatively (p=0.37). The mean(SD) clamp ISI was 2.14 ×10 -2 (1.80)mg.L.kg -1 .min -1 .pmol -1 and 2.00×10 -2 .(0.76)mg.L.kg -1 .min -1 .pmol -1 postoperatively (p=0.86). Correlation between ISI-DISST and ISI-Clamp preoperatively was r=0.81(95%CI 0.37-0.95) and post-operatively r=0.47(95%CI 0-0.88). Bland-Altman analysis demonstrates systematic bias between the two tests, where DISST underestimated insulin sensitivity compared with the clamp by 0.96×10 -2 .mg.L.kg -1 .min -1 .pmol -1 (95%CI -2.24 to 0.32). There was a strong correlation between DISST and the clamp preoperatively and DISST can be used to estimate insulin sensitivity in individuals with morbid obesity. After RYGB surgery, DISST had a weaker correlation with the clamp suggesting the fundamental physiological determinants of insulin sensitivity being measured by each method change in different ways with changes in glucose homeostasis following RYGB surgery. © Georg Thieme Verlag KG Stuttgart · New York.

New Synthetic Methods and Structure-Property Relationships in Neptunium, Plutonium, and Americium Borates. Final report

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

Albrecht-Schmitt, Thomas Edward

The past three years of support by the Heavy Elements Chemistry Program have been highly productive in terms of advanced degrees awarded, currently supported graduate students, peer-reviewed publications, and presentations made at universities, national laboratories, and at international conferences. Ph.D. degrees were granted to Shuao Wang and Juan Diwu, who both went on to post-doctoral appointments at the Glenn T. Seaborg Center at Lawrence Berkeley National Laboratory with Jeff Long and Ken Raymond, respectively. Pius Adelani completed his Ph.D. with me and is now a post-doc with Peter C. Burns. Andrea Alsobrook finished her Ph.D. and is now a post-docmore » at Savannah River with Dave Hobbs. Anna Nelson completed her Ph.D. and is now a post-doc with Rod Ewing at the University of Michigan. As can be gleaned from this list, students supported by the Heavy Elements Chemistry grant have remained interested in actinide science after leaving my program. This follows in line with previous graduates in this program such as Richard E. Sykora, who did his post-doctoral work at Oak Ridge National Laboratory with R. G. Haire, and Amanda C. Bean, who is a staff scientist at Los Alamos National Laboratory, and Philip M. Almond and Thomas C. Shehee, who are both staff scientists at Savannah River National Laboratory, Gengbang Jin who is a staff scientist at Argonne National Lab, and Travis Bray who has been a post-doc at both LBNL and ANL. Clearly this program is serving as a pipe-line for students to enter into careers in the national laboratories. About half of my students depart the DOE complex for academia or industry. My undergraduate researchers also remain active in actinide chemistry after leaving my group. Dan Wells was a productive undergraduate of mine, and went on to pursue a Ph.D. on uranium and neptunium chalcogenides with Jim Ibers at Northwestern. After earning his Ph.D., he went directly into the nuclear industry.« less

Post legalisation challenge: minimizing complications of abortion.

PubMed

Ojha, N; Sharma, S; Paudel, J

2004-01-01

Abortion has been legalized in Nepal since September 2002 by 11th amendment to the Muluki Ain. The present study was conducted in Paropakar Shree Panch Indra Rajya Laxmi Devi Maternity Hospital to assess the magnitude of induced abortion, its causes and the types of complications, in the post legalization phase. Prospective descriptive analyses of the patients who were admitted with history of induced abortion from 16th Dec 2003 to 13th March 2004 was carried out. A total of 305 cases of abortion complications were admitted during the three-month study period, which is 39.7% of the total gynaecological admissions (768). Of these 31 (10.25%) patients had history of induced abortion. Half of the induced abortion cases (52%) were of age group 21-29 yrs and 42% had three or more children. 39% of the cases had history of induced abortion at more than 12 weeks and almost half of the cases (48%) had history of family planning. The most common reason for seeking abortion was too many children (59%) followed by illegitimate pregnancy (16%). Twenty-one patients gave history of abortion being performed by doctors and the most common method used was D and C (75%). 77% of cases presented as incomplete abortion and one case presented with uterine perforation, bowel injury and peritonitis. Twenty patients had evacuation under sedation while five had manual vacuum aspiration (MVA); one patient required laparatomy. In two third of the patients intravenous fluid and antibiotics were used. Four patients required blood transfusion. Abortion complications constitute almost 40% of the total gynaecological admissions. Ten percent of the abortion cases had history of induced abortion. Medical persons, mainly doctors, performed most of the cases of induced abortion and D and C was the most commonly used method. However the patients had faced various types of complications. Untrained provider, resulting in serious life threatening injuries, performed more than a third of the cases of

Outcomes of haploidentical stem cell transplantation for chronic lymphocytic leukemia: a retrospective study on behalf of the chronic malignancies working party of the EBMT.

PubMed

van Gorkom, Gwendolyn; van Gelder, Michel; Eikema, Dirk-Jan; Blok, Henric-Jan; van Lint, M T; Koc, Yener; Ciceri, Fabio; Beelen, Dietrich; Chevallier, Patrice; Selleslag, Dominik; Blaise, Didier; Foá, Roberto; Corradini, Paolo; Castagna, Luca; Moreno, Carol; Solano, Carlos; Müller, Lutz Peter; Tischer, Johanna; Hilgendorf, Inken; Hallek, Michael; Bittenbring, Jörg; Theobald, Matthias; Schetelig, Johannes; Kröger, Nicolaus

2018-03-01

Allogeneic hematopoietic stem cell transplantation (HCT) may result in long-term disease control in high-risk chronic lymphocytic leukemia (CLL). Recently, haploidentical HCT is gaining interest because of better outcomes with post-transplantation cyclophosphamide (PTCY). We analyzed patients with CLL who received an allogeneic HCT with a haploidentical donor and whose data were available in the EBMT registry. In total 117 patients (74% males) were included; 38% received PTCY as GVHD prophylaxis. For the whole study cohort OS at 2 and 5 yrs was 48 and 38%, respectively. PFS at 2 and 5 yrs was 38 and 31%, respectively. Cumulative incidence (CI) of NRM in the whole group at 2 and 5 years were 40 and 44%, respectively. CI of relapse at 2 and 5 yrs were 22 and 26%, respectively. All outcomes were not statistically different in patients who received PTCY compared to other types of GVHD prophylaxis. In conclusion, results of haploidentical HCT in CLL seem almost identical to those with HLA-matched donors. Thereby, haploidentical HCT is an appropriate alternative in high risk CLL patients with a transplant indication but no available HLA-matched donor. Despite the use of PTCY, the CI of relapse seems not higher than observed after HLA-matched HCT.

Regional Anesthesia and Valproate Sodium for the Prevention of Chronic Post-Amputation Pain

DTIC Science & Technology

2013-10-01

revised documents August Non-perishable Supplies ordered & received DUKE IRB approved study via expedited review September Submitted all revisions...2013 February March April May June July August September October HRPO request for revised, addtn’l docs VA approved protocol...A few candidate gene polymorphisms have been linked to pain susceptibility, including catechol-O-methyltranferase ( COMT ). This gene modulates

Reviewing Canadian Post-Secondary Education: Post-Secondary Education Policy in Post-Industrial Canada

ERIC Educational Resources Information Center

Kirby, Dale

2007-01-01

Since 2004, a number of Canadian provinces have initiated comprehensive reviews of their respective public post-secondary education systems. This paper examines the ways in which these provincial post-secondary education reviews are consistent with the pervasive influence of economic globalization on higher education and a more market-driven and…

Association between rotating night shift work and risk of coronary heart disease among women

PubMed Central

Vetter, Céline; Devore, Elizabeth E.; Wegrzyn, Lani R.; Massa, Jennifer; Speizer, Frank E.; Kawachi, Ichiro; Rosner, Bernard; Stampfer, Meir J.; Schernhammer, Eva S.

2016-01-01

Importance Prospective studies linking shift work to coronary heart disease (CHD) have been inconsistent and limited by short follow-up. Objective Determine whether rotating night shift work is associated with CHD risk. Design, Setting and Participants Prospective cohort study of 189,158 initially healthy women followed over 24 years in the Nurses' Health Studies (NHS (1988-2012): N=73,623, and NHS2 (1989-2013): N=115,535). Exposure Questionnaire-based lifetime history of rotating night shift work (≥3 night shifts/month, plus day and evening shifts) at baseline; also updated every 2-4yrs in NHS2. Main Outcomes and Measures Incident CHD, i.e. non-fatal myocardial infarction, CHD death, angiogram-confirmed angina pectoris, coronary artery bypass grafting (CABG), stents, and angioplasty. Results During follow-up, 7,303 incident CHD cases in NHS (mean age at baseline: 54.5yrs) and 3,519 in NHS2 (34.8yrs) occurred. In multivariable adjusted Cox proportional hazards models, increasing years of baseline rotating night shift work were associated with a significantly higher CHD risk in both cohorts (NHS: age-standardized incidence rate (IR)<5yrs per 100,000 person-years=435.1, hazard ratio (HR)<5yrs=1.02, 95% confidence interval (CI)=0.97-1.08, IR5-9yrs=525.7, HR5-9yrs=1.12, 95%CI=1.02-1.22, IR≥10yrs=596.9, HR≥10yrs=1.18, 95%CI=1.10-1.26; Ptrend<0.001; NHS2: IR<5yrs=130.6, HR<5yrs=1.05, 95%CI=0.97-1.13; IR5-9yrs=151.6, HR5-9yrs=1.12, 95%CI=0.99-1.26; HR≥10yrs=178.0, HR≥10yrs=1.15, 95%CI=1.01-1.32; Ptrend=0.01), compared to women who never worked rotating night shifts (NHS: IRnever=425.5, NHS2: IRnever=122.6). In NHS, the association between duration of rotating night shift work and CHD was stronger in the first half of follow-up (IR<5yrs=382.4, HR<5yrs=1.10, 95%CI=1.01-1.21, IR5-9yrs=483.1, HR5-9yrs=1.19, 95%CI=1.03-1.39, IR≥10yrs=494.4, HR≥10yrs=1.27, 95%CI =1.13-1.42, Ptrend <0.001) than in the second half (IR<5yrs=424.8, HR<5yrs=0.98, 95%CI=0.92-1.05, IR5

PhysDoc: A Distributed Network of Physics Institutions: Collecting, Indexing, and Searching High Quality Documents by Using Harvest; The Dublin Core Metadata Initiative: Mission, Current Activities, and Future Directions; Information Services for Higher Education: A New Competitive Space; Intellectual Property Conservancies.

ERIC Educational Resources Information Center

Severiens, Thomas; Hohlfeld, Michael; Zimmermann, Kerstin; Hilf, Eberhard R.; von Ossietzky, Carl; Weibel, Stuart L.; Koch, Traugott; Hughes, Carol Ann; Bearman, David

2000-01-01

Includes four articles that discuss a variety to topics, including a distributed network of physics institutions documents called PhysDocs which harvests information from the local Web-servers of professional physics institutions; the Dublin Core metadata initiative; information services for higher education in a competitive environment; and…

Insomnia symptoms and their association with workplace productivity: cross-sectional and pre-post intervention analyses from a large multinational manufacturing company.

PubMed

Espie, Colin A; Pawlecki, Brent; Waterfield, Dickon; Fitton, Kit; Radocchia, Michael; Luik, Annemarie I

2018-06-01

Symptoms of insomnia are common and might impact work productivity. We investigated the relationship between insomnia symptoms and workplace productivity in a global manufacturing company. Within an uncontrolled, cross-sectional study, employees from a US-based company were invited to participate in an online evaluation comprising the Sleep Condition Indicator (SCI) measuring symptoms of insomnia (high score indicating better sleep), 2 items of the Work Productivity and Impairment Index (WPAI) measuring 'presenteeism' and 'absenteeism' (high score indicating loss of work productivity) and 1 item of the Perceived Stress Scale (PSS) from January 2015 onwards. Pre-post, within-subject data were collected to preliminary test effects of 'sleep tips' and digital cognitive behavioral therapy (dCBT). In 2798 employees [72% male; mean age 46.3(SD11.8) yrs] sleep was poorest in plant staff [SCI = 3.70(2.73)], then retail staff [4.34(3.02)], then office staff [4.95(2.83): overall F(2,2786) = 43.7, P < .0001]. More insomnia symptoms were associated with WPAI presenteeism (r = -.489, P < .0001; R 2 = 23.9%). Insomnia symptoms also were the strongest predictor of work-related productivity, with stress only contributing a further 9%. A regression model for 'absenteeism' was statistically significant but of limited predictive value (R 2 = 3.4%). In a sample of 214 employees with pre- and post-intervention data, the SCI of those exposed to sleep tips significantly increased from 5.36(3.28) to 6.01(3.22), [t(123) = -3.02, P = .003] and from 3.08(2.24) to 6.03(2.97) for those who accessed dCBT [t(89) = -8.40, P < .001). Symptoms of insomnia are associated with poor work productivity. Additionally, targeted insomnia interventions may offer potential to improve sleep and work productivity. Copyright © 2018 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

[Flexible root posts].

PubMed

Vadachkoriia, N R; Mandzhavidze, N A; Gumberidze, N Sh

2009-02-01

The article discusses the current state of restoration techniques of root canal treatment. Nowadays, technical progress allows manufacturers to develop flexible fiberglass posts, aspiring not only to an excellent aesthetics and mechanical properties (first of all, in comparison with metal and cast posts), but also to maintenance of their radio density and a wide range of forms. Growth of fiberglass posts popularity testifies to their clinical efficiency that also is confirmed by results of long-term researches. Introduction of fiberglass posts in a dental practice has rendered huge influence on restoration techniques of root canal treatment. Convincing factors of fiberglass posts superiority provide restoration the appearance similar with the natural dentition; possess close to dentine elasticity; creation of monolithic structure with hard tooth tissues and composite cement, posts, in case of need, can be easily adjusted on length, adhesive linkage of posts gives them additional stability. Modern researches have confirmed that only elastic, namely carbon fiber and the fiberglass posts made of modern technologies possess similar physical properties, as tooth structure. They can create reliable biomimetic design; solve a complex of aesthetic and functional restoration problems.

Sedation of Patients With Disorders of Consciousness During Neuroimaging: Effects on Resting State Functional Brain Connectivity.

PubMed

Kirsch, Muriëlle; Guldenmund, Pieter; Ali Bahri, Mohamed; Demertzi, Athena; Baquero, Katherine; Heine, Lizette; Charland-Verville, Vanessa; Vanhaudenhuyse, Audrey; Bruno, Marie-Aurélie; Gosseries, Olivia; Di Perri, Carol; Ziegler, Erik; Brichant, Jean-François; Soddu, Andrea; Bonhomme, Vincent; Laureys, Steven

2017-02-01

To reduce head movement during resting state functional magnetic resonance imaging, post-coma patients with disorders of consciousness (DOC) are frequently sedated with propofol. However, little is known about the effects of this sedation on the brain connectivity patterns in the damaged brain essential for differential diagnosis. In this study, we aimed to assess these effects. Using resting state functional magnetic resonance imaging 3T data obtained over several years of scanning patients for diagnostic and research purposes, we employed a seed-based approach to examine resting state connectivity in higher-order (default mode, bilateral external control, and salience) and lower-order (auditory, sensorimotor, and visual) resting state networks and connectivity with the thalamus, in 20 healthy unsedated controls, 8 unsedated patients with DOC, and 8 patients with DOC sedated with propofol. The DOC groups were matched for age at onset, etiology, time spent in DOC, diagnosis, standardized behavioral assessment scores, movement intensities, and pattern of structural brain injury (as assessed with T1-based voxel-based morphometry). DOC were associated with severely impaired resting state network connectivity in all but the visual network. Thalamic connectivity to higher-order network regions was also reduced. Propofol administration to patients was associated with minor further decreases in thalamic and insular connectivity. Our findings indicate that connectivity decreases associated with propofol sedation, involving the thalamus and insula, are relatively small compared with those already caused by DOC-associated structural brain injury. Nonetheless, given the known importance of the thalamus in brain arousal, its disruption could well reflect the diminished movement obtained in these patients. However, more research is needed on this topic to fully address the research question.

Post driver for steel guardrail posts : final report.

DOT National Transportation Integrated Search

2003-01-01

The objective of this research project was to locate an existing product, or if necessary, design and develop a product for use as a driver for steel guardrail posts. The post driver would also be able to minimize the bending and twisting of the stee...

Restoration of shallow peatlands on Exmoor (UK): initial effects on water quality

NASA Astrophysics Data System (ADS)

Grand-Clement, Emilie; Luscombe, David; Anderson, Karen; Gatis, Naomi; Ashe, Josie; Brazier, Richard

2014-05-01

Historical and recent anthropogenic pressure has had dramatic effects on peatlands throughout the UK. In the South West, drainage for agricultural reclamation and peat cutting since the 19th century has progressively altered the hydrological behaviour of the peatlands of Exmoor and Dartmoor National Parks. Lower water table levels have caused increased oxidation, erosion and vegetation change, further affecting the storage of carbon and the provision of other ecosystem services (i.e. supply of drinking water, biodiversity). Moreover, the location of these peatlands at the southernmost margin of the UK peatlands' geographical extent makes them extremely vulnerable to the predicted effects of climate change, i.e. increased temperature and change in rainfall pattern. An extensive programme of peatland restoration is currently underway on Exmoor. Drainage ditches were blocked to reinstate the hydrological behaviour, reduce the outflow of dissolved organic carbon and, in doing so, improve other ecosystem services delivered by peatlands. This paper will report on the water quality monitoring results from a small headwater catchment in Exmoor. We will show results comparing changes in Dissolved Organic Carbon (DOC) losses and colour pre- and post-restoration. Our experimental approach uses event-based water quality monitoring across three drainage ditches that are representative of the different scales of damage in the area. Samples were taken back to the laboratory and analysed for DOC and colour, using UV spectrophotometry and UV-vis spectrometry respectively. DOC loads were calculated using discharge for each drain. Overall, DOC concentrations ranged between 3 and 30mg/L. Both pre and post- restoration datasets presented high seasonal variability, with higher concentrations measured from June to September. No significant change in DOC concentrations was observed in the 6 months after restoration. It is hypothesised that the effects of restoration could be hidden by

Sources and Age of Aquatic DOC, CO2 And CH4 Exported From a Swedish Peatland

NASA Astrophysics Data System (ADS)

Campeau, A.; Wallin, M.; Billett, M. F.; Nilsson, M. B.; Laudon, H.; Oquist, M. G.; Bishop, K. H.

2015-12-01

Northern peatlands store as much organic matter as the equivalent of all the CO2 currently present in the earth's atmosphere. The peat carbon storage results from the progressive accumulation of organic matter since the end of the last glaciation (~10 000 years). The stability of these large carbon storages, under the influence of climate change, is unknown. Runoff represents one of the major C fluxes out of northern peatlands, and is particularly sensitive to changes in climate and hydrological regimes. Identifying the sources and age of aquatic C export will help assess the stability and future role of northern peatlands as active components of the global C cycle. We have characterized both radiogenic (14C) and stable carbon isotopes (δ13C) of DOC, CO2 and CH4 across a four-meter deep ombrotrophic peatland and its stream outlet. Previous studies have shown that about 34% of the estimated net ecosystem exchange from this peatland system, is lost through aquatic C export. We determined that fermentation processes in the peat acts as the main production pathway for stream CO2 (mean δ13C =-4.9‰) and CH4 (mean δ13C = -67.8‰). The seasonal variability in both sources and age of C was high. Despite this dynamism, the application of carbon isotopes allowed us to trace back the origin of aquatic C exports from the peatland.

A laboratory comparison of individual Targis/Vectris posts with standard fiberglass posts.

PubMed

Corsalini, Massimo; Genovese, Katia; Lamberti, Luciano; Pappalettere, Carmine; Carella, Mauro; Carossa, Stefano

2007-01-01

This article presents an in vitro analysis of a specific occlusal loading test on endodontically treated teeth restored with 2 different composite post materials. Individual, customized posts (IFPs) were compared to standard fiberglass posts (SFPs). The selected IFPs (standard cylindric Targis/Vectris posts) were compared to SFPs (Conic 6% Post, Ghimas). The posts were first subjected to a 3-point bending test to compare their flexural elastic properties. They were then used to restore 22 endodontically treated artificial maxillary central incisors and subjected to a specific occlusal loading simulation test. The loading test showed that IFP restorations performed better than SFP restorations. A clinical evaluation of this laboratory observation is suggested.

Automated determination of the stable carbon isotopic composition (δ13C) of total dissolved inorganic carbon (DIC) and total nonpurgeable dissolved organic carbon (DOC) in aqueous samples: RSIL lab codes 1851 and 1852

USGS Publications Warehouse

Révész, Kinga M.; Doctor, Daniel H.

2014-01-01

The purposes of the Reston Stable Isotope Laboratory (RSIL) lab codes 1851 and 1852 are to determine the total carbon mass and the ratio of the stable isotopes of carbon (δ13C) for total dissolved inorganic carbon (DIC, lab code 1851) and total nonpurgeable dissolved organic carbon (DOC, lab code 1852) in aqueous samples. The analysis procedure is automated according to a method that utilizes a total carbon analyzer as a peripheral sample preparation device for analysis of carbon dioxide (CO2) gas by a continuous-flow isotope ratio mass spectrometer (CF-IRMS). The carbon analyzer produces CO2 and determines the carbon mass in parts per million (ppm) of DIC and DOC in each sample separately, and the CF-IRMS determines the carbon isotope ratio of the produced CO2. This configuration provides a fully automated analysis of total carbon mass and δ13C with no operator intervention, additional sample preparation, or other manual analysis. To determine the DIC, the carbon analyzer transfers a specified sample volume to a heated (70 °C) reaction vessel with a preprogrammed volume of 10% phosphoric acid (H3PO4), which allows the carbonate and bicarbonate species in the sample to dissociate to CO2. The CO2 from the reacted sample is subsequently purged with a flow of helium gas that sweeps the CO2 through an infrared CO2 detector and quantifies the CO2. The CO2 is then carried through a high-temperature (650 °C) scrubber reactor, a series of water traps, and ultimately to the inlet of the mass spectrometer. For the analysis of total dissolved organic carbon, the carbon analyzer performs a second step on the sample in the heated reaction vessel during which a preprogrammed volume of sodium persulfate (Na2S2O8) is added, and the hydroxyl radicals oxidize the organics to CO2. Samples containing 2 ppm to 30,000 ppm of carbon are analyzed. The precision of the carbon isotope analysis is within 0.3 per mill for DIC, and within 0.5 per mill for DOC.

Effects of low calorie diet-induced weight loss on post-exercise heart rate recovery in obese men.

PubMed

Kim, Maeng Kyu

2014-06-01

Heart Rate Recovery (HRR) after maximum exercise is a reactivation function of vagus nerve and an independent risk factor that predicts cardiovascular disease and mortality. Weight loss obtained through dietary programs has been employed as a therapy to reduce risks of cardiovascular disease and obesity. Eighteen subjects of middle aged obese men (age 44.8 ± 1.6 yrs, BMI 29.7 ± 0.5 kg/m(2)) were selected for this study. As a weight loss direction, the nutritional direction of low-calorie diet mainly consisted of carbohydrate, protein, and fat has been conducted for 3 months. Blood pressure was measured after overnight fasting, and blood samples were collected from the antecubital vein before and after weight loss program. All the pre- and post-exercise 'HRR decay constant's were assessed by using values of HRR (heart recovery rate; 2 minutes) and HR measured after reached to the maximal oxygen uptake (VO2max) exploited the bicycle ergometer. After the completion of weight loss program, body weight and BMI were significantly decreased, but the Heart Rate (HR) after maximum exercise and in steady state were not changed significantly (p > 0.05). The post-exercise HRR after the weight loss did not show significant changes in perspectives of 30 seconds (-16.6 ± 2.3 to -20.2 ± 2.1 beats/min, p > 0.05) and 60 seconds (-33.5 ± 3.4 to -34.6 ± 2.8 beats/min, p > 0.05) respectively but in perspectives of 90 seconds (-40.9 ± 2.6 to -48.1 ± 3.1 beats/min, p < 0.05) and 120 seconds (-48.6 ± 2.6 to -54.3 ± 3.5 beats/min, p < 0.05), they were decreased significantly. Pre-'HRR decay constant's of 0.294 ± 0.02 %/second were significantly increased to post-values of 0.342 ± 0.03 %/second (p = 0.026). Changes in 'HRR decay constant' were significantly correlated with changes in blood glucose (r = -0.471, p < 0.05) and maximal oxygen consumption (VO2max, r = 0.505, p < 0.05) respectively. The low-calorie diet directed to obese middle aged men for 3 months significantly

15 CFR 14.21 - Standards for financial management systems.

Code of Federal Regulations, 2013 CFR

2013-01-01

...-PROFIT, AND COMMERCIAL ORGANIZATIONS Post-Award Requirements Financial and Program Management § 14.21... the DoC guarantees or insures the repayment of money borrowed by the recipient, the Grants Officer may... part 223, “Surety Companies Doing Business with the United States.” ...

15 CFR 14.21 - Standards for financial management systems.

Code of Federal Regulations, 2011 CFR

2011-01-01

...-PROFIT, AND COMMERCIAL ORGANIZATIONS Post-Award Requirements Financial and Program Management § 14.21... the DoC guarantees or insures the repayment of money borrowed by the recipient, the Grants Officer may... part 223, “Surety Companies Doing Business with the United States.” ...

15 CFR 14.21 - Standards for financial management systems.

Code of Federal Regulations, 2014 CFR

2014-01-01

...-PROFIT, AND COMMERCIAL ORGANIZATIONS Post-Award Requirements Financial and Program Management § 14.21... the DoC guarantees or insures the repayment of money borrowed by the recipient, the Grants Officer may... part 223, “Surety Companies Doing Business with the United States.” ...

76 FR 79760 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-22

... posts all comments received without change to http://www.regulations.gov , including any personal... each applicant continues to meet the vision exemption requirements. These factors provide an adequate... Policy. [FR Doc. 2011-32710 Filed 12-21-11; 8:45 am] BILLING CODE 4910-EX-P ...

78 FR 45545 - Collection of Information under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-29

.... OIRA posts its decisions on ICRs online at http://www.reginfo.gov/public/do/PRAMain after the comment... Commandant for Command, Control, Communications, Computers and Information Technology. [FR Doc. 2013-18068... DEPARTMENT OF HOMELAND SECURITY Coast Guard [USCG-2013-0045] Collection of Information under...

Vegetative state, minimally conscious state, akinetic mutism and Parkinsonism as a continuum of recovery from disorders of consciousness: an exploratory and preliminary study

PubMed Central

Formisano, Rita; D’Ippolito, Mariagrazia; Risetti, Monica; Riccio, Angela; Caravasso, Chiara Falletta; Catani, Sheila; Rizza, Federica; Forcina, Antonio; Buzzi, Maria Gabriella

Summary The aim of this study was to review the usefulness of clinical and instrumental evaluation in individuals with disorders of consciousness (DOC). Thirteen subjects with severe acquired brain injury (ABI) and a diagnosis of DOC were evaluated using the Coma Recovery Scale in its revised version (CRS-R) and a new global disability index, the Post-Coma Scale (PCS). These instruments were administered both by a neutral examiner (professional) and by a professional in the presence of a caregiver. All patients were also scored using the International Classification of Functioning, Disability and Health (ICF). A statistically significant correlation between CRS-R and PCS was demonstrated. However, there also emerged significant differences in responsiveness between professional versus caregiver+professional assessment using the two scales. The emotional stimulation provided by significant others (caregivers) during administration of DOC evaluation scales may improve the assessment of responsiveness. PMID:21693084

Black Peak Caldera, Alaska: Preliminary Investigations of the ˜4600 BP Caldera-forming Eruption and Subsequent Post-caldera Activity

NASA Astrophysics Data System (ADS)

McGimsey, R. G.; Neal, C. A.; Adleman, J. A.; Larsen, J. F.; Ramsey, M.

2003-12-01

Black Peak Caldera is a 4-km-diameter, circular crater located on the Alaska Peninsula midway between Aniakchak and Veniaminof Volcanoes, approximately 45 km south-southwest of the community of Port Heiden and 730 km southwest of Anchorage. The caldera truncates a highly altered volcanic edifice that consists largely of lava domes, minor lava flows, and volcaniclastics. New radiocarbon dating of soils beneath the ash-flow deposit confirm earlier dating and place the age of the caldera-forming event at approximately 4600 14C yrs BP. Climactic fall deposits from this eruption form a prominent, crystal-rich, regional tephra horizon informally referred to as the 'salt and pepper ash.' Coeval pyroclastic flow deposits fill the two major drainages around the caldera to a depth of up to 100 m, and extend at least 10 km from the caldera rim. Deposits consist of a lower, highly pumiceous, crystal-rich dacite flow unit capped by a conspicuously oxidized, lithic-rich unit that is less aerially extensive. We estimate the bulk volume of the eruption to be less than 10-20 km3. Post-caldera eruptions at Black Peak have largely consisted of viscous, crystal-rich, hornblende-bearing dacite lavas forming a coalescing field of steep-sided, blocky domes and at least one coulee that fill much of the caldera. No coarse tephra fall deposits related to these eruptions have been found. Fine-grained, highly altered ash fall deposits, possibly related to dome emplacement, form a thick, monotonous sequence on the caldera rim and immediately overlying the ash flow in exposures near the caldera. This suggests that the dome eruptions closely followed caldera formation. Several domes collapsed over the eastern rim of the caldera to form coarse block and ash avalanche fans that extend ~1.5 km down Red Bluff Creek. Radiocarbon dating of an overlying soil indicates an age of >500 14C yrs BP for these avalanches. There are no reports of eruptive activity at Black Peak in historic time (approximately

Reflecting on the challenges of building a rich interconnected metadata database to describe the experiments of phase six of the coupled climate model intercomparison project (CMIP6) for the Earth System Documentation Project (ES-DOC) and anticipating the opportunities that tooling and services based on rich metadata can provide.

NASA Astrophysics Data System (ADS)

Pascoe, C. L.

2017-12-01

The Coupled Model Intercomparison Project (CMIP) has coordinated climate model experiments involving multiple international modelling teams since 1995. This has led to a better understanding of past, present, and future climate. The 2017 sixth phase of the CMIP process (CMIP6) consists of a suite of common experiments, and 21 separate CMIP-Endorsed Model Intercomparison Projects (MIPs) making a total of 244 separate experiments. Precise descriptions of the suite of CMIP6 experiments have been captured in a Common Information Model (CIM) database by the Earth System Documentation Project (ES-DOC). The database contains descriptions of forcings, model configuration requirements, ensemble information and citation links, as well as text descriptions and information about the rationale for each experiment. The database was built from statements about the experiments found in the academic literature, the MIP submissions to the World Climate Research Programme (WCRP), WCRP summary tables and correspondence with the principle investigators for each MIP. The database was collated using spreadsheets which are archived in the ES-DOC Github repository and then rendered on the ES-DOC website. A diagramatic view of the workflow of building the database of experiment metadata for CMIP6 is shown in the attached figure.The CIM provides the formalism to collect detailed information from diverse sources in a standard way across all the CMIP6 MIPs. The ES-DOC documentation acts as a unified reference for CMIP6 information to be used both by data producers and consumers. This is especially important given the federated nature of the CMIP6 project. Because the CIM allows forcing constraints and other experiment attributes to be referred to by more than one experiment, we can streamline the process of collecting information from modelling groups about how they set up their models for each experiment. End users of the climate model archive will be able to ask questions enabled by the

Post-Epidemic Chikungunya Disease on Reunion Island: Course of Rheumatic Manifestations and Associated Factors over a 15-Month Period

PubMed Central

Sissoko, Daouda; Malvy, Denis; Ezzedine, Khaled; Renault, Philippe; Moscetti, Frederic; Ledrans, Martine; Pierre, Vincent

2009-01-01

Although the acute manifestations of Chikungunya virus (CHIKV) illness are well-documented, few data exist about the long-term rheumatic outcomes of CHIKV-infected patients. We undertook between June and September 2006 a retrospective cohort study aimed at assessing the course of late rheumatic manifestations and investigating potential risk factors associated with the persistence of these rheumatic manifestations over 15 months. 147 participants (>16 yrs) with laboratory-confirmed CHIKV disease diagnosed between March 1 and June 30, 2005, were identified through a surveillance database and interviewed by telephone. At the 15-month-period evaluation after diagnosis, 84 of 147 participants (57%) self-reported rheumatic symptoms. Of these 84 patients, 53 (63%) reported permanent trouble while 31 (37%) had recurrent symptoms. Age ≥45 years (OR = 3.9, 95% CI 1.7–9.7), severe initial joint pain (OR = 4.8, 95% CI 1.9–12.1), and presence of underlying osteoarthritis comorbidity (OR = 2.9, 95% CI 1.1–7.4) were predictors of nonrecovery. Our findings suggest that long-term CHIKV rheumatic manifestations seem to be a frequent underlying post-epidemic condition. Three independent risk factors that may aid in early recognition of patients with the highest risk of presenting prolonged CHIKV illness were identified. Such findings may be particularly useful in the development of future prevention and care strategies for this emerging virus infection. PMID:19274071

Identification of the Mechanisms Underlying Antiestrogen Resistance: Breast Cancer Research Partnership between FIU-UM Braman Family Breast Cancer Institute

DTIC Science & Technology

2009-06-01

glutathione modifiers or overexpressing GSH restoring enzymes; and (c) raised or restored levels of Trx by thioredoxin modifiers or overexpressing Trxn. To...the challenge by hiring a Post-Doc (Dr. Alok Deoraj) in place of her. Research • Showed that overexpression of ROS modifiers Trx , Catalase

Alumni Profiles.

PubMed

Nitschke, Jonathan R; Quattropani, Anna; Corminboeuf, Clémence; Velonia, Kelly; Wilkinsoe, Kevin J; Kubel, Frank

2009-12-01

Former PhD students, post-docs and junior researchers of the Section de chimie et biochimie now holding positions at different universities and private companies remember the time they spent in Geneva and give an account of how this has set off and influenced their careers.

78 FR 57677 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-19

... posts all comments received without change to http://www.regulations.gov , including any personal... continues to meet the vision exemption requirements. These factors provide an adequate basis for predicting... Policy. [FR Doc. 2013-22775 Filed 9-18-13; 8:45 am] BILLING CODE 4910-EX-P ...

77 FR 12066 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-28

... holidays. OIRA posts its decisions on ICRs online at http://www.reginfo.gov/public/do/PRAMain after the... Command, Control, Communications, Computers and Information Technology. [FR Doc. 2012-4607 Filed 2-27-12... DEPARTMENT OF HOMELAND SECURITY Coast Guard [USCG-2011-1061] Collection of Information Under...

Experimental study on filtration and continuous regeneration of a particulate filter system for heavy-duty diesel engines.

PubMed

Tang, Tao; Zhang, Jun; Cao, Dongxiao; Shuai, Shijin; Zhao, Yanguang

2014-12-01

This study investigated the filtration and continuous regeneration of a particulate filter system on an engine test bench, consisting of a diesel oxidation catalyst (DOC) and a catalyzed diesel particulate filter (CDPF). Both the DOC and the CDPF led to a high conversion of NO to NO2 for continuous regeneration. The filtration efficiency on solid particle number (SPN) was close to 100%. The post-CDPF particles were mainly in accumulation mode. The downstream SPN was sensitively influenced by the variation of the soot loading. This phenomenon provides a method for determining the balance point temperature by measuring the trend of SPN concentration. Copyright © 2014. Published by Elsevier B.V.

[Disease-free survival related factors in breast cancer].

PubMed

Dávila-Arias, Cristina; Ocón, Olga; Fernández, Mariana F; Arrebola, Juan Pedro; Sánchez, María José; Aneiros, José; Torné, Pablo; Olea, Nicolás

2014-10-07

To evaluate the relationship between the clinical and pathological parameters of the primary tumor and disease-free survival (DFS) in a sample of hospital cases of invasive breast cancer. We performed a retrospective cohort study in 635 patients recruited at San Cecilio University Hospital in Granada (Spain) between 1994 and 2006. Information on the primary tumor and the outcomes of patients was collected by reviewing the medical records. Predictors of recurrence and/or metastasis and DFS (follow up of 3, 5 and 10 years) were analyzed by using Cox regression analysis. Multivariate models adjusted for age, tumor size, lymph nodal status, histological grade and estrogen and progesterone receptor expression showed a higher risk of recurrence and/or metastasis and lower DFS (adjusted relative risk, 95% confidence intervals) with tumor size (3 yrs: 3.00, 1.79-5.03; 5 yrs: 2.56, 1.65-3.98; 10 yrs: 2.16, 1.44-3.24), lymph nodal status (3 yrs: 4.58, 2.42-8.65; 5 yrs: 3.84, 2.35-6.30; 10 yrs: 3.08, 2.05-4.61), lymphovascular invasion (5 yrs: 1.88, 1.16-3.04; 10 yrs: 2.19, 1.43-3.35), multifocal and/or multicenter tumors (3 yrs: 2.69, 1.46-4.96; 5 yrs: 1.90, 1.08-3.35) and p53 protein expression (3 yrs: 2.03, 1.00-4.09). DFS was positively associated with an increased expression of progesterone receptor (3 yr: 0.48, 0.26-0.89; 5 yrs: 0.58, 0.35-0.97; 10 yrs: 0.59, 0.38-0.90). The biological characteristics of the primary tumor can be used to identify patients with distinctive prognoses and DFS, and could be helpful in making individual follow up strategies. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

International Conference on Metalorganic Vapor Chase Epitaxy (ICMOVPE) XVIII

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

Dupuis, Russell D.

The ICMOVPE-XVIII conference created meaningful opportunities for intellectual challenge, networking opportunities, and intellectual stimulation for graduate students, Post-Doctoral Fellows and all attendees. This technical and social program further provided many opportunities for communication, brainstorming, and transfer of information as well as the development of collaborations across many institutions and companies. We had a significant number of members of underrepresented groups in STEM attending this conference. We also are publishing the proceedings of this conference with the Journal of Crystal Growth, a journal which receives wide electronic distribution in many academic institutions world-wide, making the technical information presented at ICMOVPE-XVIII havemore » a much broader impact than would otherwise be possible. ICMOVPE XVIII had a total of 216 presentations and of these; there were 70 Student oral or poster presentations. The funds we obtained for student support from the Department of Energy were distributed among the registered students and Post Docs to supplement the full cost of registration of $1,100 each for regular registration to the reduced rate of at $850 each for graduate students and Post Docs.« less

Effects of biodiesel, engine load and diesel particulate filter on nonvolatile particle number size distributions in heavy-duty diesel engine exhaust.

PubMed

Young, Li-Hao; Liou, Yi-Jyun; Cheng, Man-Ting; Lu, Jau-Huai; Yang, Hsi-Hsien; Tsai, Ying I; Wang, Lin-Chi; Chen, Chung-Bang; Lai, Jim-Shoung

2012-01-15

Diesel engine exhaust contains large numbers of submicrometer particles that degrade air quality and human health. This study examines the number emission characteristics of 10-1000 nm nonvolatile particles from a heavy-duty diesel engine, operating with various waste cooking oil biodiesel blends (B2, B10 and B20), engine loads (0%, 25%, 50% and 75%) and a diesel oxidation catalyst plus diesel particulate filter (DOC+DPF) under steady modes. For a given load, the total particle number concentrations (N(TOT)) decrease slightly, while the mode diameters show negligible changes with increasing biodiesel blends. For a given biodiesel blend, both the N(TOT) and mode diameters increase modestly with increasing load of above 25%. The N(TOT) at idle are highest and their size distributions are strongly affected by condensation and possible nucleation of semivolatile materials. Nonvolatile cores of diameters less than 16 nm are only observed at idle mode. The DOC+DPF shows remarkable filtration efficiency for both the core and soot particles, irrespective of the biodiesel blend and engine load under study. The N(TOT) post the DOC+DPF are comparable to typical ambient levels of ≈ 10(4)cm(-3). This implies that, without concurrent reductions of semivolatile materials, the formation of semivolatile nucleation mode particles post the after treatment is highly favored. Copyright © 2011 Elsevier B.V. All rights reserved.

Site-Specific Advantages in Skeletal Geometry and Strength at the Proximal Femur and Forearm in Young Female Gymnasts

PubMed Central

Dowthwaite, Jodi N.; Rosenbaum, Paula F.; Scerpella, Tamara A.

2012-01-01

Purpose We evaluated site-specific skeletal adaptation to loading during growth,comparing radius (RAD) and femoral neck (FN) DXA scans in young female gymnasts (GYM) and non-gymnasts (NON). Methods Subjects from an ongoing longitudinal study (8-26 yrs old) underwent annual DXA scans (proximal femur, forearm, total body) and anthropometry, completing maturity and physical activity questionnaires. This cross-sectional analysis used the most recent data meeting the following criteria: gynecological age ≤2.5 yrs post-menarche; GYM annual mean gymnastic exposure ≥5.0 h/wk in the prior year. Bone geometric and strength indices were derived from scans for 173 subjects (8-17 yrs old) via hip structural analysis (femoral narrow neck, NN) and similar radius formulae (1/3 and Ultradistal (UD)). Maturity was coded as M1 (Tanner I breast), M2 (pre-menarche, ≥Tanner II breast) or M3 (post-menarche). ANOVA and chi square compared descriptive data. Two factor ANCOVA adjusted for age, height, total body non-bone lean mass and percent body fat; significance was tested for main effects and interactions between gymnastic exposure and maturity. Results At the distal radius, GYM means were significantly greater than NON means for all variables (p<0.05). At the proximal femur, GYM exhibited narrower periosteal and endosteal dimensions, but greater indices of cortical thickness, BMC, aBMD and section modulus, with lower buckling ratio (p <0.05). However, significant interactions between maturity and loading were detected for the following: 1) FN bone mineral content (BMC), NN buckling ratio (GYM BMC advantages only in M1 and M3; for BMC and buckling ratio, M1 advantages were greatest; 2) 1/3 radius BMC, width, endosteal diameter, cortical cross-sectional area, section modulus (GYM advantages primarily post-menarche); 3) UD radius BMC and axial compressive strength (GYM advantages were larger with greater maturity, greatest post-menarche). Conclusions Maturity-specific comparisons

Primary care providers' discussion of fall prevention approaches with their older adult patients-DocStyles, 2014.

PubMed

Burns, Elizabeth R; Haddad, Yara K; Parker, Erin M

2018-03-01

Falls are the leading cause of fatal and non-fatal injuries among older adults. The American and British Geriatric Societies recommend a fall risk assessment to identify risk factors and guide interventions to prevent these falls. This study describes the self-reported discussion of fall prevention approaches used by primary care providers (PCPs)-family practitioners, internists and nurse practitioners-who treat older adults. Results are described overall and by PCP type. We analyzed a sample of 1210 U.S. PCPs who participated in the 2014 DocStyles survey. PCPs reported on their recommendation of fall prevention approaches including general exercise, Tai Chi, medication adjustments, home safety modifications, vitamin D supplements, assistive devices, alarm systems, and referral to physical therapy, foot specialist, or vision specialist. Frequencies and adjusted odds ratios for fall prevention approaches were assessed by provider and practice characteristics. Self-reported discussion of any fall prevention approaches was 89.3%. Controlling for provider and practice characteristics, there were significant differences for some approaches by provider type. Family practitioners were more likely to suggest home modification [adjusted Odds Ratio: 1.8 (1.3-2.4)], exercise [aOR: 2.0 (1.5-2.5)], and Tai Chi [aOR: 1.5 (1.0-2.2)] than internists. Nurse practitioners were more likely to suggest home modification [aOR: 2.1 (1.3-3.4)] and less likely to suggest vitamin D [aOR: 0.6 (0.4-1.0)] than internists. Fall prevention suggestions vary by type of PCP. Dissemination of geriatric guidelines should include all PCPs who routinely see older adults.

The chronic bronchitis phenotype in subjects with and without COPD: the PLATINO study.

PubMed

de Oca, Maria Montes; Halbert, Ronald J; Lopez, Maria Victorina; Perez-Padilla, Rogelio; Tálamo, Carlos; Moreno, Dolores; Muiño, Adrianna; Jardim, José Roberto B; Valdivia, Gonzalo; Pertuzé, Julio; Menezes, Ana Maria B

2012-07-01

Little information exists regarding the epidemiology of the chronic bronchitis phenotype in unselected chronic obstructive pulmonary disease (COPD) populations. We examined the prevalence of the chronic bronchitis phenotype in COPD and non-COPD subjects from the PLATINO study, and investigated how it is associated with important outcomes. Post-bronchodilator forced expiratory volume in 1 s/forced vital capacity <0.70 was used to define COPD. Chronic bronchitis was defined as phlegm on most days, at least 3 months per year for ≥ 2 yrs. We also analysed another definition: cough and phlegm on most days, at least 3 months per year for ≥ 2 yrs. Spirometry was performed in 5,314 subjects (759 with and 4,554 without COPD). The proportion of subjects with and without COPD with chronic bronchitis defined as phlegm on most days, at least 3 months per year for ≥ 2 yrs was 14.4 and 6.2%, respectively. Using the other definition the prevalence was lower: 7.4% with and 2.5% without COPD. Among subjects with COPD, those with chronic bronchitis had worse lung function and general health status, and had more respiratory symptoms, physical activity limitation and exacerbations. Our study helps to understand the prevalence of the chronic bronchitis phenotype in an unselected COPD population at a particular time-point and suggests that chronic bronchitis in COPD is possibly associated with worse outcomes.

The ROSAT Field Sources --- What are they?

NASA Astrophysics Data System (ADS)

Caillault, J.-P.; Briceno, C.; Martin, E. L.; Palla, F.; Wichmann, R.

Recent studies using the ROSAT All-Sky Survey towards nearby star-forming regions have identified a widely dispersed population of X-ray active stars and have suggested that these objects are older PMS stars located far from molecular clouds. Another group, however, has presented a simple model assuming continuing star formation over the past 10^8 yrs that quantitatively reproduces the number, surface density, X-ray emission, and optical properties of the RASS sources, leading to the argument that these stars are not PMS stars, but young MS stars of ages up to approximately 10^8 yrs. A third party notes that the similarity between molecular cloud lifetimes and the ambipolar diffusion timescale implies that star formation does not take place instantaneously, nor at a constant rate. They thus argue that the probability of finding a large population of old stars in a star-forming region is intrinsically very small and that the post-T Tauri problem is by and large nonexistent.

Inflammation and immune system activation in aging: a mathematical approach.

PubMed

Nikas, Jason B

2013-11-19

Memory and learning declines are consequences of normal aging. Since those functions are associated with the hippocampus, I analyzed the global gene expression data from post-mortem hippocampal tissue of 25 old (age ≥ 60 yrs) and 15 young (age ≤ 45 yrs) cognitively intact human subjects. By employing a rigorous, multi-method bioinformatic approach, I identified 36 genes that were the most significant in terms of differential expression; and by employing mathematical modeling, I demonstrated that 7 of the 36 genes were able to discriminate between the old and young subjects with high accuracy. Remarkably, 90% of the known genes from those 36 most significant genes are associated with either inflammation or immune system activation. This suggests that chronic inflammation and immune system over-activity may underlie the aging process of the human brain, and that potential anti-inflammatory treatments targeting those genes may slow down this process and alleviate its symptoms.

Context Specificity of Post-Error and Post-Conflict Cognitive Control Adjustments

PubMed Central

Forster, Sarah E.; Cho, Raymond Y.

2014-01-01

There has been accumulating evidence that cognitive control can be adaptively regulated by monitoring for processing conflict as an index of online control demands. However, it is not yet known whether top-down control mechanisms respond to processing conflict in a manner specific to the operative task context or confer a more generalized benefit. While previous studies have examined the taskset-specificity of conflict adaptation effects, yielding inconsistent results, control-related performance adjustments following errors have been largely overlooked. This gap in the literature underscores recent debate as to whether post-error performance represents a strategic, control-mediated mechanism or a nonstrategic consequence of attentional orienting. In the present study, evidence of generalized control following both high conflict correct trials and errors was explored in a task-switching paradigm. Conflict adaptation effects were not found to generalize across tasksets, despite a shared response set. In contrast, post-error slowing effects were found to extend to the inactive taskset and were predictive of enhanced post-error accuracy. In addition, post-error performance adjustments were found to persist for several trials and across multiple task switches, a finding inconsistent with attentional orienting accounts of post-error slowing. These findings indicate that error-related control adjustments confer a generalized performance benefit and suggest dissociable mechanisms of post-conflict and post-error control. PMID:24603900

After the flood: consistency in DOM response to the 2010/2011 Australian floods

NASA Astrophysics Data System (ADS)

Shutova, Y.; Baker, A.; Bridgeman, J.; Henderson, R.

2014-12-01

The 2010/2011 floods in Eastern Australia were one of the worst on record, causing more than one billion AUD of damages and killing 35 people. This field campaign, monitoring raw water DOM concentration and character on three contrasting rivers across the region captured the late recession curve (October 2011- September 2012). DOM was characterized using fluorescence excitation-emission matrix (EEM) spectra with PARAFAC analysis; δ 13C-DOC; and molecular size using liquid chromatography with organic carbon, UV254 and nitrogen detection (LC-OCD) to identify DOC fractions: biopolymers, humic substance (HS), building blocks (BB), low molecular weight acids, and low molecular weight neutrals. Despite the difference in catchment and climatic zones, similar trends were observed in all three rivers, where DOC concentrations gradually decreased in river streams over a year from 8-11 mgCL-1 to 3-4 mgCL-1, followed by similar changes of HS, BB and fluorescent terrestrially delivered DOM components (C1-C3). In Allyn and Patterson rivers the proportion of HS, fluorescent terrestrially delivered DOM components (C1, C2) in DOC have decreased, in contrast to Logan River, where the ratio of HS/DOC was highly variable and showed no particular trends. The proportion of other DOC components remained almost the same. Molecular weight of the HS declined from 700 gmol-1 to 610 gmol-1 in all sites. δ 13C-DOC increased during monitoring, this could be linked to general decrease of DOM proportion delivered from C4 type plants after the flood. Overall, although DOC concentration decreased over the year post flood at all sites, most importantly the composition of DOM changed, with major changes occurring in proportion of humic-like and fluorescent terrestrially delivered DOM. Therefore it is important to monitor DOM character to be able to assess the impact of climate change and extreme weather events on the DOM transport and transformation.

Post-traumatic stress disorder in U.S. soldiers with post-traumatic headache.

PubMed

Rosenthal, Jacqueline F; Erickson, Jay C

2013-01-01

To determine the impact of post-traumatic stress disorder (PTSD) on headache characteristics and headache prognosis in U.S. soldiers with post-traumatic headache. PTSD and post-concussive headache are common conditions among U.S. Army personnel returning from deployment. The impact of comorbid PTSD on the characteristics and outcomes of post-traumatic headache has not been determined in U.S. Army soldiers. A retrospective cohort study was conducted among 270 consecutive U.S. Army soldiers diagnosed with post-traumatic headache at a single Army neurology clinic. All subjects were screened for PTSD at baseline using the PTSD symptom checklist. Headache frequency and characteristics were determined for post-traumatic headache subjects with and without PTSD at baseline. Headache measures were reassessed 3 months after the baseline visit, and were compared between groups with and without PTSD. Of 270 soldiers with post-traumatic headache, 105 (39%) met screening criteria for PTSD. There was no significant difference between subjects with PTSD and those without PTSD with regard to headache frequency (17.2 vs 15.7 headache days per month; P = .15) or chronic daily headache (58.1% vs 52.1%; P = .34). Comorbid PTSD was associated with higher headache-related disability as measured by the Migraine Disability Assessment Score. Three months after the baseline neurology clinic visit, the number of subjects with at least 50% reduction in headache frequency was similar among post-traumatic headache cases with and without PTSD (25.9% vs 26.8%). PTSD is prevalent among U.S. Army soldiers with post-traumatic headache. Comorbid PTSD is not associated with more frequent headaches or chronic daily headache in soldiers evaluated at a military neurology clinic for chronic post-traumatic headache. Comorbid PTSD does not adversely affect short-term headache outcomes, although prospective controlled trials are needed to better assess this relationship. © 2013 American Headache

75 FR 50799 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-17

... posts all comments received without change to http://www.regulations.gov , including any personal... each applicant continues to meet the vision exemption standards. These factors provide an adequate... Policy and Program Development. [FR Doc. 2010-20226 Filed 8-16-10; 8:45 am] BILLING CODE 4910-EX-P ...

76 FR 20611 - Electronic On-Board Recorders and Hours of Service Supporting Documents

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-13

..., used, and disseminated (e.g., in post- accident litigation or in personal litigation such as divorce proceedings). Based on the factors above, the Agency has determined that the statute requires it to protect... Doc. 2011-8789 Filed 4-12-11; 8:45 am] BILLING CODE 4910-EX-P ...

78 FR 52939 - Collection of Information under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-27

.... OIRA posts its decisions on ICRs online at http://www.reginfo.gov/public/do/PRAMain after the comment..., Communications, Computers and Information Technology. [FR Doc. 2013-20787 Filed 8-26-13; 8:45 am] BILLING CODE... DEPARTMENT OF HOMELAND SECURITY Coast Guard [USCG-2013-0222] Collection of Information under...

77 FR 1942 - Collection of Information Under Review by Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-12

... through Friday, except Federal holidays. OIRA posts its decisions on ICRs online at http://www.reginfo.gov..., Communications, Computers and Information Technology. [FR Doc. 2012-400 Filed 1-11-12; 8:45 am] BILLING CODE 9110... DEPARTMENT OF HOMELAND SECURITY Coast Guard [USCG-2011-1014] Collection of Information Under...

Flexural properties, morphology and bond strength of fiber-reinforced posts: influence of post pretreatment.

PubMed

Braga, Neilor Mateus Antunes; Souza-Gabriel, Aline Evangelista; Messias, Danielle Cristine Furtado; Rached-Junior, Fuad Jacob Abi; Oliveira, Camila Fávero; Silva, Ricardo Gariba; Silva-Sousa, Yara T Corrêa

2012-01-01

The aim of this study was to assess the influence of surface pretreatments of fiber-reinforced posts on flexural strength (FS), modulus of elasticity (ME) and morphology of these posts, as well as the bond strength (BS) between posts and core material. Fifty-two fiber posts (smooth and serrated) were assigned to 4 groups (n=13): no treatment (control), 10% hydrogen peroxide (HP) for 10 min (HP-10), 24% HP for 1 min (HP-24) and airborne-particle abrasion (Al(2)O(3)). To evaluate FS and ME, a 3-point bending test was performed. Three posts of each group were examined by scanning electron microscopy. Composite resin was used as the core build-up and samples were sectioned to obtain microtensile sticks. Data were analyzed by ANOVA and Tukey's test (α=0.05). For FS, significant differences were observed between posts type and surface pretreatment (p<0.05), with the highest means for the smooth posts. Al2O3 provided higher FS than HP-24. Al(2)O(3) promoted higher ME than HP-24 and control. SEM images revealed partial dissolution of the resin matrix in all treated groups. The smooth posts had higher BS and FS than serrated posts (p<0.05). Mechanical properties of the glass fiber posts and the bond strength between posts and composite material were not altered by the surface treatments, except for airborne-particle abrasion that increased the post elastic modulus.

Healthcare providers' attitudes and behaviours related to paediatric mild traumatic brain injury: results from the 2014 DocStyles survey.

PubMed

Sarmiento, Kelly; Donnell, Zoe; Hoffman, Rosanne; Tennant, Bethany

2018-04-23

Explore healthcare providers' experiences managing mTBI and better understand their use of mTBI assessment tools and guidelines. Cross-sectional Methods: A random sample of 1,760 healthcare providers responded to the web-based DocStyles survey between June 18 and 30, 2014. The sample included family/general practitioners, internists, pediatricians, and nurse practitioners who reported seeing pediatric patients. We examined their experiences with mTBI to identify opportunities to increase preparedness and improve management of mTBI. Fifty-nine percent of healthcare providers reported that they diagnosed or managed pediatric patients with mTBI within the last 12 months. Of those, 44.4% felt 'very prepared' to make decisions about when pediatric patients can safety return to activities, such as school and sports after a mTBI. When asked how often they use screening or assessment tools to assess pediatric patients with mTBI, almost half reported that they 'seldom' or 'never' use those resources (24.6% and 22.0%, respectively). Most healthcare providers reported seeing pediatric patients with mTBI, yet most feel only somewhat prepared to manage this injury in their practise. Broader use of screening tools and guidelines, that include clinical decision support tools, may be useful for healthcare providers who care for pediatric patients with mTBI.

10. FLOOR 1; CENTER POST AND POSTS UNDER STONE BEAMS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. FLOOR 1; CENTER POST AND POSTS UNDER STONE BEAMS WHICH SUPPORT BRIDGE BEAMS FOR BRIDGE TREES; WEDGES FOR ADJUSTING HEIGHT OF BRIDGE TREE CAN BE SEEN - Shelter Island Windmill, Manwaring Road, Shelter Island, Suffolk County, NY

Determining the optimal approach to identifying individuals with chronic obstructive pulmonary disease: The DOC study.

PubMed

Ronaldson, Sarah J; Dyson, Lisa; Clark, Laura; Hewitt, Catherine E; Torgerson, David J; Cooper, Brendan G; Kearney, Matt; Laughey, William; Raghunath, Raghu; Steele, Lisa; Rhodes, Rebecca; Adamson, Joy

2018-06-01

Early identification of chronic obstructive pulmonary disease (COPD) results in patients receiving appropriate management for their condition at an earlier stage in their disease. The determining the optimal approach to identifying individuals with chronic obstructive pulmonary disease (DOC) study was a case-finding study to enhance early identification of COPD in primary care, which evaluated the diagnostic accuracy of a series of simple lung function tests and symptom-based case-finding questionnaires. Current smokers aged 35 or more were invited to undertake a series of case-finding tools, which comprised lung function tests (specifically, spirometry, microspirometry, peak flow meter, and WheezoMeter) and several case-finding questionnaires. The effectiveness of these tests, individually or in combination, to identify small airways obstruction was evaluated against the gold standard of spirometry, with the quality of spirometry tests assessed by independent overreaders. The study was conducted with general practices in the Yorkshire and Humberside area, in the UK. Six hundred eighty-one individuals met the inclusion criteria, with 444 participants completing their study appointments. A total of 216 (49%) with good-quality spirometry readings were included in the analysis. The most effective case-finding tools were found to be the peak flow meter alone, the peak flow meter plus WheezoMeter, and microspirometry alone. In addition to the main analysis, where the severity of airflow obstruction was based on fixed ratios and percent of predicted values, sensitivity analyses were conducted by using lower limit of normal values. This research informs the choice of test for COPD identification; case-finding by use of the peak flow meter or microspirometer could be used routinely in primary care for suspected COPD patients. Only those testing positive to these tests would move on to full spirometry, thereby reducing unnecessary spirometric testing. © 2018 John Wiley

1. Post card view of the bridge, c. 1910. Post ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Post card view of the bridge, c. 1910. Post card courtesy Carol Poh Miller. Photocopy by Berni Rich, Score Photographers Cleveland, OH - B & O Railroad Bridge Number 464, Spanning Old Ship Canal & Cuyahoga River, Cleveland, Cuyahoga County, OH

The Relative Importance of Post-Acute Care and Readmissions for Post-Discharge Spending.

PubMed

Huckfeldt, Peter J; Mehrotra, Ateev; Hussey, Peter S

2016-10-01

To understand what patterns of health care use are associated with higher post-hospitalization spending. Medicare hospital, skilled nursing, inpatient rehabilitation, and home health agency claims, and Medicare enrollment data from 2007 and 2008. For 10 common inpatient conditions, we calculated variation across hospitals in price-standardized and case mix-adjusted Medicare spending in the 30 days following hospital discharge. We estimated the fraction of spending differences between low- and high-spending hospitals attributable to readmissions versus post-acute care, and within post-acute care between inpatient rehabilitation facility (IRF) versus skilled nursing facility (SNF) use. For each service, we distinguished between differences in probability of use and spending conditional on use. We identified index hospital claims and examined hospital and post-acute care occurring within a 30-day period following hospital discharge. For each Medicare Severity Diagnosis-Related Group (MS-DRG) at each hospital, we calculated average price-standardized Medicare payments for readmissions, SNFs, IRFs, and post-acute care overall (also including home health agencies and long-term care hospitals). There was extensive variation across hospitals in Medicare spending in the 30 days following hospital discharge. For example, the interquartile range across hospitals ranged from $1,245 for chronic obstructive pulmonary disease to over $4,000 for myocardial infarction MS-DRGs. The proportion of differences attributable to readmissions versus post-acute care differed across conditions. For myocardial infarction, 74 to 93 percent of the variation was due to readmissions. For hip and femur procedures and joint replacement, 72 to 92 percent of the variation was due to differences in post-acute care spending. There was also variation in the relative importance of the type of post-acute spending. For hip and femur procedures, joint replacement, and stroke, whether patients received IRF

Anatomy of the Kitimat fiord system, British Columbia

NASA Astrophysics Data System (ADS)

Shaw, John; Stacey, Cooper D.; Wu, Yongsheng; Lintern, D. Gwyn

2017-09-01

The geomorphic complexity of the Kitimat fiord system, on the active margin of British Columbia, Canada, is analysed from several perspectives. Sub-glacial landforms and sediments show that grounded ice exiting the fiord system at the last glacial maximum streamed down Moresby Trough towards the Queen Charlotte trough mouth fan. After brief halts on the inner shelf, grounded ice margins cleared the fiord threshold perhaps by c. 15.5 ka cal. yrs BP, and certainly before 13 ka cal. yrs BP. Just outside the fiords, meltwater plumes deposited stratified glaciomarine sediments interbedded with submarine slides. Inside the fiords, thick glaciomarine sediments were deposited, and large transverse moraines formed during temporary halts in retreat. Several glacial outburst floods eroded the Kitkiata moraine and deposited distinctive mud deposits. Postglacial sedimentation on fiord floors has been spatially variable: drifts of mud > 90 m-thick corresponding with areas of low current velocity alternate with areas of non-deposition and erosion corresponding with areas of high velocity. The fiord system hosts more than a hundred morphologically diverse fan deltas that can be classified in the Prior and Bornhold (1989, 1990) system. Submarine mass transport was most frequent immediately following ice retreat (15.5-11.5 ka cal. yrs BP). The largest event ( 1.2 km3) involved failure of glaciomarine sediment on a submarine moraine at Squally Channel, and consequent movement of material into the adjacent deep basin. This event occurred post-13 ka cal. yrs BP. In the postglacial phase, mass transport continued on a lesser scale up to the present day, most intensively in Kitimat Arm. From the perspective of glacial landforms, postglacial sedimentation and mass transport, this Pacific active margin fiord system has some parallels with fiord systems on Canada's east coast passive margin, and with Norwegian fiords, but the intensive development of Holocene fan deltas is strongly

University of Maryland MRSEC - Education

Science.gov Websites

Educational Education Pre-College Programs Homeschool Programs Undergraduate & Graduate Programs Teacher : Championing Service-based Education Outreach Since 1996 Program Areas Pre-college Programs Project Lead the , and post-docs effective skills in education outreach at the pre-college level. The UMD-MRSEC uses a

78 FR 57679 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-19

... number for this notice. Note that DOT posts all comments received without change to http://www... requirements. These factors provide an adequate basis for predicting each driver's ability to continue to drive... for Policy. [FR Doc. 2013-22771 Filed 9-18-13; 8:45 am] BILLING CODE 4910-EX-P ...

78 FR 14410 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-05

... Agency name and the docket number for this notice. Note that DOT posts all comments received without... requirements. These factors provide an adequate basis for predicting each driver's ability to continue to drive... for Policy. [FR Doc. 2013-05096 Filed 3-4-13; 8:45 am] BILLING CODE 4910-EX-P ...

77 FR 48590 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-14

.... Note that DOT posts all comments received without change to http://www.regulations.gov , including any.... These factors provide an adequate basis for predicting each driver's ability to continue to drive safely... Administrator for Policy. [FR Doc. 2012-19885 Filed 8-13-12; 8:45 am] BILLING CODE 4910-EX-P ...

75 FR 38602 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-02

... posts all comments received without change to http://www.regulations.gov , including any personal.... These factors provide an adequate basis for predicting each driver's ability to continue to drive safely... Policy and Program Development. [FR Doc. 2010-16180 Filed 7-1-10; 8:45 am] BILLING CODE 4910-EX-P ...

Career paths through the U.S. EPA

EPA Science Inventory

In a recent survey of employee satisfaction, the U.S. EPA was ranked 6th of the 30 large federal agencies that were surveyed (http://data.bestplacestowork.org). I have been working as a post doc at the EPA since receiving my Ph.D. in ecological physiology from the University of ...

A Study of Year-Round Schools. Volume III: Handbook for Conducting Cost Analysis of Year-Round School Programs.

ERIC Educational Resources Information Center

Burnett, Robert W.

This manual is intended for use by district officials undertaking analysis of the costs of year-round school (YRS) programs. To analyze the budgetary impact of YRS, it is necessary to determine the actual costs incurred with the YRS program and to compare these costs to expenses that would be incurred without the YRS program. A simulated…

Post-Traumatic Stress Disorder

MedlinePlus

... U V W X Y Z Post-Traumatic Stress Disorder Share: © Matthew Lester Post-traumatic stress disorder (PTSD) is an anxiety disorder that can ... military combat. For Consumers General Information Post-Traumatic Stress Disorder ( NIMH ) Anxiety Information Stress Information Depression Information ...

Cycling of DOC and DON by Novel Heterotrophic and Photoheterotrophic Bacteria in the Ocean: Final Report

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

Kirchman, David L.

2008-12-09

The flux of dissolved organic matter (DOM) through aquatic bacterial communities is a major process in carbon cycling in the oceans and other aquatic systems. Our work addressed the general hypothesis that the phylogenetic make-up of bacterial communities and the abundances of key types of bacteria are important factors influencing the processing of DOM in aquatic ecosystems. Since most bacteria are not easily cultivated, the phylogenetic diversity of these microbes has to be assessed using culture-independent approaches. Even if the relevant bacteria were cultivated, their activity in the lab would likely differ from that under environmental conditions. This project foundmore » variation in DOM uptake by the major bacterial groups found in coastal waters. In brief, the data suggest substantial differences among groups in the use of high and molecular weight DOM components. It also made key discoveries about the role of light in affecting this uptake especially by cyanobacteria. In the North Atlantic Ocean, for example, over half of the light-stimulated uptake was by the coccoid cyanobacterium, Prochlorococcus, with the remaining uptake due to Synechococcus and other photoheterotrophic bacteria. The project also examined in detail the degradation of one organic matter component, chitin, which is often said to be the second most abundant compound in the biosphere. The findings of this project contribute to our understanding of DOM fluxes and microbial dynamics supported by those fluxes. It is possible that these findings will lead to improvements in models of the carbon cycle that have compartments for dissolved organic carbon (DOC), the largest pool of organic carbon in the oceans.« less

An SEM Approach for the Evaluation of Intervention Effects Using Pre-Post-Post Designs

ERIC Educational Resources Information Center

Mun, Eun Young; von Eye, Alexander; White, Helene R.

2009-01-01

This study analyzes latent change scores using latent curve models (LCMs) for evaluation research with pre-post-post designs. The article extends a recent article by Willoughby, Vandergrift, Blair, and Granger (2007) on the use of LCMs for studies with pre-post-post designs, and demonstrates that intervention effects can be better tested using…

Value of Surgery In Patients With Negative Imaging And Sporadic Zollinger-Ellison Syndrome (ZES)

PubMed Central

Norton, Jeffrey A.; Fraker, Douglas L.; Alexander, H. Richard; Jensen, Robert T

2012-01-01

Objectives To address the value of surgery in sporadic Zollinger-Ellison syndrome (ZES) patients with negative imaging studies. Background Medical control of acid hypersecretion in patients with sporadic Zollinger-Ellison syndrome (ZES) is highly effective. This has led to these patients frequently not sent to surgery, especially if preoperative imaging studies are negative, due in large part because almost no data exists on the success of surgery in this group. Methods 58 prospectively studied sporadic ZES patients (17% of total studied) had negative imaging studies and their surgical outcome was compared to 117 patients with positive imaging results. Results 35 patients had negative imaging in the pre-somatostatin receptor scintigraphy era (SRS) and 23 in the post-SRS era. The image negative patients had long disease histories prior to surgery (mean±SEM, from onset=7.9±1[range −0.25-35 yrs]) and 25% were followed ≥2yrs from diagnosis. At surgery, gastrinoma was found in 57/58 patients (98%). Tumors were small (mean=0.8cm, 60% < 1 cm). The most common primary sites were: duodenal 64%, pancreatic 17%, and lymph node (LN)(10%). 50% had a primary only, 41% primary + LN, and 7% had liver metastases. 35/58(60%) were cured immediately postoperatively and at last follow-up [mean-9.4yrs, range 0.2-22yrs], 27 patients (46%) remained cured. During follow-up 3 patients died, each was found to have liver metastases at surgery. In comparison to the image positive patients, those with negative imaging had lower preop fasting gastrin levels; a longer delay prior to surgery; more frequently had a small duodenal tumors; less frequently had a pancreatic tumor, multiple tumors or developed a new lesion postoperatively and had a longer survival. Conclusions Imaging negative sporadic ZES patients are not rare even in the post-SRS period. An experienced surgeon can find gastrinoma in almost every patient (98%) and nearly one-half (46%) are cured, a rate similar to imaging

Rates of adult acute inpatients documented as at risk of refeeding syndrome by dietitians.

PubMed

Owers, Emma L; Reeves, Anneli I; Ko, Susan Y; Ellis, Aleshia K; Huxtable, Shannon L; Noble, Sally A; Porteous, Helen E; Newman, Eli J; Josephson, Christine A; Roth, Rachel A; Byrne, Clare E; Palmer, Michelle A

2015-02-01

Identification of Refeeding Syndrome (RFS) is vital for prevention and treatment of metabolic disturbances, yet no information exists that describes identification rates by dietitians in acute care. We aimed to describe rates and demographics of inpatients identified by dietitians as at-risk of RFS and factors associated with electrolyte levels post-dietetic assessment. Eligible participants were adult (≥ 18 yrs) acute care inpatients reviewed by dietitians between March 2012-February 2013 and not admitted to intensive care prior to first dietetic assessment. Patient information was sourced from medical charts. Chi-squared, t-tests and linear regression analyses were conducted. Of 1661 eligible inpatients (55%F, 65 ± 18 yrs), 9% (n = 151) were documented as at-risk of RFS in the first dietetic medical chart entry. On average, patients identified with RFS-risk had four days greater hospital stay, were 13 kg lighter, more likely classified SGA C (36% vs. 7%), and on a modified diet (52% vs. 35%) than non-RFS patients (p < 0.05). Very low and low electrolyte values occurred within seven days post-dietetic assessment in 7% and 52%, respectively, of inpatients with RFS-risk. Regression analysis showed that electrolyte supplementation was positively associated (β = 0.145-0.594), and number of RFS-related risk factors negatively associated (β = -0.044-0.122), with potassium, magnesium and phosphate levels within seven days post-dietetic assessment (p < 0.05). Nine percent of adult inpatients were documented as at-risk of RFS by dietitians. Identification of at-risk patients was in accordance with RFS guidelines. Electrolyte supplementation was positively associated with electrolyte levels post-assessment. Consistency of RFS-risk identification between dietitians requires determination. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Doc Tales

ERIC Educational Resources Information Center

Golden, Larry; Alamia, Jennifer; Baker, Ria; Chilson, Sally; Choucroun, Pierre; Cook, Katrina; de Vries-Kell, Sabina; Marbach, Christina; Peters, Scott

2005-01-01

Acceptance into a doctoral program is personally affirming and gives rise to optimism. It is also true that any change in the life of a person, even an apparently positive one, causes stress. The first cohort of students in a new doctoral program in counseling writes about the impact of embarking on a doctorate on themselves and their significant…

Post-Slavery? Post-Segregation? Post-Racial? A History of the Impact of Slavery, Segregation, and Racism on the Education of African Americans

ERIC Educational Resources Information Center

Span, Christopher M.

2015-01-01

This chapter details how slavery, segregation, and racism impacted the educational experiences of African Americans from the colonial era to the present. It argues that America has yet to be a truly post-slavery and post-segregation society, let alone a post-racial society.

Work with Us | Research Site Name | NREL

Science.gov Websites

ullamco laboris nisi ut aliquip ex ea commodo consequat. Hero Image - Width of 1746px - Height can vary ex ea commodo consequat. Learn about our technology partnership agreements. Use our cutting-edge commercialization programs. Join Our Team Find an opportunity: Job | Internship | Post Doc | Director's Postdoctoral

Developing the New Infostructure

DTIC Science & Technology

2003-12-01

Engineering Physics and Applied Mathematics from Cornell, and a post-doc in neurophysiology from University of Mississippi Medical School. Dr. Jens G...transport you about 6,000 miles here to England, I’ve been doing some work with, I found it, this is kind of enlightening , in England, they don’t, this

76 FR 8809 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-15

... include the Agency name and the docket number for this notice. Note that DOT posts all comments received.... These factors provide an adequate basis for predicting each driver's ability to continue to drive safely..., Office of Policy. [FR Doc. 2011-3268 Filed 2-14-11; 8:45 am] BILLING CODE 4910-EX-P ...

75 FR 27621 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-17

... for this Notice. Note that DOT posts all comments received without change to http://www.regulations.... These factors provide an adequate basis for predicting each driver's ability to continue to drive safely... Policy and Program Development. [FR Doc. 2010-11711 Filed 5-14-10; 8:45 am] BILLING CODE 4910-EX-P ...

75 FR 54940 - Agency Information Collection (IC) Activities; Revision of an Approved IC; Accident Recordkeeping...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-09

... include the Agency name and the docket number for this Notice. Note that DOT posts all comments received... underlying this IC is 49 CFR 390.15, ``Assistance in investigations and special studies.'' It requires motor... Information Technology. [FR Doc. 2010-22456 Filed 9-8-10; 8:45 am] BILLING CODE 4910-EX-P ...

[Post-partum thyroiditis].

PubMed

Neves, Celestino; Alves, Marta; Delgado, Luís; Medina, J Luís

2009-01-01

In the post-partum period the immune alterations are associated with the multiple autoimmune diseases relapse. After birth, immune-tolerance variation slowly disappear, and is observed a return to a normal state - after an exacerbation period - of autoimmune reactivity, during which a great increase in T cells and autoantibodies is observed. In this period - 3 to 9 months after birth - the thyroid autoimmune disease relapses or reappears. The reactivation of the immune system in the post-partum period unchains an acute phase of celular destruction which characterizes the post-partum thyroiditis.

Fabricating fiber-reinforced composite posts.

PubMed

Manhart, Jürgen

2011-03-01

Endodontic posts do not increase the strength of the remaining tooth structure in endodontically treated teeth. On the contrary, depending on the post design employed (tapered versus parallel-sided), the root can be weakened relative to the amount of tooth removed during preparation. In many cases, if there has been a high degree of damage to the clinical crown, conservative preparation for an anatomic tapered (biomimetic) post with the incorporation of a ferrule on solid tooth structure is necessary to protect the reaming root structure as well as for the long-term retention of the composite resin core and the definitive restoration. Adhesively luted endodontic posts reinforced with glass or quartz fiber lead to better homogeneous tension distribution when loaded than rigid metal or zirconium oxide ceramic posts. Fiber-reinforced posts also possess advantageous optical properties over metal or metal oxide post systems. The clinician should realize that there are admittedly substantial differences in the mechanical loading capacity of the different fiber-reinforced endodontic posts and should be aware of such differences in order to research and select a suitable post system for use.

ED-11DEMOGRAPHIC, CLINICAL AND SURVIVAL FEATURES OF CHILDHOOD CENTRAL NERVOUS SYSTEM TUMORS IN ISTANBUL UNIVERSITY, ONCOLOGY INSTITUTE DURING 22 YEARS (1990-2012)

PubMed Central

Kebudi, Rejin; Darendeliler, Emin; Gorgun, Omer; Agaoglu, Fulya Yaman; Uludag, Dilek; Ayan, Inci

2014-01-01

OBJECTIVES: The aim of this study is to identify demographic, clinical and survival features of childhood central nervous system (CNS) tumors admitted to Istanbul University, Oncology Institute, Pediatric Hematology-Oncology in 22 years. METHODS: Charts of patients <19 years admitted were evaluated retrospectively. (Istanbul University Cerrahpasa Medical Faculty Clinical Trials, Ethics Committee no. 83045809-3507). RESULTS: CNS tumors (n = 494) comprised 20,5 % of the 2413 children with cancer, diagnosed between 1990-2012. Male/female:1,25. Median age was 6,5 years (0.13-18yrs). 51 patients had NF1, 4 had tuberosclerosis. Distrubution according to histopathology/diagnosis was as follows: 35 % (n = 173) Medulloblastoma and other embryonal tumors, 17% (n = 84) astrocytoma other than optic gliomas, 16,5% (n = 82) ependymoma and choroid plexus tumors, 14% (n = 69) optic glioma, and 12,8% (n = 63) diffuse pontine gliomas. 5-yrs and 10-yrs overall survival (OS) in the whole group were 61% and 55,4% respectively. 29,6 % of the patients had metastasis in the CSF and/or the spinal axis and/or gross residual tumor, these had 5-yrs and 10-yrs OS of 36,5% and 27,2 %, whereas the rest had 5-yrs and 10-yrs OS are 73% and 68,9% (p < 0,001). Medulloblastoma and other embryonal tumors had 5-yrs and 10-yrs OS 58,4% and 57,5% . Ependymoma and choroid plexus carcinomas had 5-yrs and 10-yrs OS of 48,4% and 31,4%. Low grade and high grade astrocytomas had 10-yrs OS of 95 % and 40% respectively (p < 0,001). Second tumors were diagnosed in two medulloblastoma patients, one malignant nerve sheath tumor at 9 years, a case with concurrent high glade glioma and mediastinal lymphoblastic lymphoma at 3,5 years. CONCLUSIONS: The most common solid tumor in our cohort, similar to developed countries, was CNS tumors. Embryonal tumors comprised the majority of the CNS tumors treated in our institution. 5 year survival was 61 %. These children should be followed up for late effects including second

Post-quantum cryptography.

PubMed

Bernstein, Daniel J; Lange, Tanja

2017-09-13

Cryptography is essential for the security of online communication, cars and implanted medical devices. However, many commonly used cryptosystems will be completely broken once large quantum computers exist. Post-quantum cryptography is cryptography under the assumption that the attacker has a large quantum computer; post-quantum cryptosystems strive to remain secure even in this scenario. This relatively young research area has seen some successes in identifying mathematical operations for which quantum algorithms offer little advantage in speed, and then building cryptographic systems around those. The central challenge in post-quantum cryptography is to meet demands for cryptographic usability and flexibility without sacrificing confidence.

Post-quantum cryptography

NASA Astrophysics Data System (ADS)

Bernstein, Daniel J.; Lange, Tanja

2017-09-01

Cryptography is essential for the security of online communication, cars and implanted medical devices. However, many commonly used cryptosystems will be completely broken once large quantum computers exist. Post-quantum cryptography is cryptography under the assumption that the attacker has a large quantum computer; post-quantum cryptosystems strive to remain secure even in this scenario. This relatively young research area has seen some successes in identifying mathematical operations for which quantum algorithms offer little advantage in speed, and then building cryptographic systems around those. The central challenge in post-quantum cryptography is to meet demands for cryptographic usability and flexibility without sacrificing confidence.

Post retention: the effect of sequence of post-space preparation, cementation time, and different sealers.

PubMed

Boone, K J; Murchison, D F; Schindler, W G; Walker, W A

2001-12-01

Many endodontic sealers contain constituents that have been shown to inhibit the polymerization of resin cements. This may be important when prefabricated posts are cemented at the same appointment as root canal obturation. This study evaluated the effects of cementing posts with a resin cement immediately or at a delayed time period after obturation using Roth's 801 Elite Grade or AH26 sealer cements. The contribution of mechanical post-space preparation was also assessed as a critical variable. One hundred twenty extracted canines were randomly divided into eight experimental groups. The variables evaluated were the order of post preparation (either before or after obturation), the type of sealer used, and the time of post cementation. All teeth received a stainless steel #6 Parapost XP cemented with a resin cement, Panavia 21. Each experimental group underwent tensile testing for retention using an Instron universal testing machine. For both sealers posts cemented in teeth in which the canal was obturated before post-space preparation and thus had sealer-contaminated dentin removed by the space preparation procedure had significantly higher retentive values than those obturated after post-space preparation in which contaminated dentin might remain. Sealer used and time of cementation had no specific effect on retention. Achieving a clean, "freshened" dentinal surface during mechanical post-space preparation seems to be a critical variable for post retention when a resin cement is used.

Persistent Influences of the 2002 Hayman Fire on Stream Nitrate and Dissolved Organic Carbon

NASA Astrophysics Data System (ADS)

Rhoades, C.; Pierson, D. N.; Fegel, T. S., II; Chow, A. T.; Covino, T. P.

2016-12-01

Large, high severity wildfires alter the physical and biological conditions that determine how watersheds retain and release nutrients and regulate stream water quality. For five years after the 2002 Hayman Fire burned in Colorado conifer forests, stream nitrate concentrations and export increased steadily in watersheds with extensive high-severity burning. Stream temperature and turbidity also increased in relation to the extent of high-severity burning and remained elevated above background levels throughout the initial five year post-fire period. Our recent sampling documents that 14 years after the Hayman Fire stream nitrate remains an order of magnitude higher in extensively-burned (35-90%) compared to unburned watersheds (0.2 vs 2.8 mg L-1). Nitrate represents 83% of the total dissolved N in extensively-burned watersheds compared to 29% in unburned watersheds. In contrast, dissolved organic carbon (DOC), was highest in watersheds that burned to a moderate extent (10-20%) and lowest in those with extensive burning. Catchments with a moderate extent burned had DOC concentrations 2.5 and 1.7 times more than those with extensive burning and unburned catchments, respectively. Peak concentrations of DOC and nitrate track the rising limb of the streamflow hydrograph and reach a maximum in May, but patterns among burn extent categories were seasonally consistent. Current riparian conditions are linked to stream nitrate in burned watersheds. For example, stream nitrate increases proportionally to the extent of riparian zones with low shrub cover (R2 = 0.76). We found signs of watershed recovery compared to the initial post-fire period; stream temperature and turbidity remained elevated in extensively burned catchments, but increases were only significant during the spring season. The persistent stream nitrate concentrations as well as the relation between riparian cover and post-fire stream nitrate may help prioritize restoration planting efforts and mitigate chronic

75 FR 5036 - Proposed Posting, Posting and Deposting of Stockyards

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-01

...The Grain Inspection, Packers and Stockyards Administration published a document in the Federal Register on July 6, 2004, concerning the proposed posting, posting and deposting of stockyards. The document shows the facility number for Shamrock Livestock Commission, Shamrock, Texas is the same as the facility number assigned to Texas Cattle Exchange, Inc., Eastland, Texas (TX-346).

15 CFR 14.32 - Real property.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Real property. 14.32 Section 14.32... ORGANIZATIONS Post-Award Requirements Property Standards § 14.32 Real property. The DoC award shall prescribe requirements for recipients concerning the use and disposition of real property acquired in whole or in part...

15 CFR 14.32 - Real property.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Real property. 14.32 Section 14.32... ORGANIZATIONS Post-Award Requirements Property Standards § 14.32 Real property. The DoC award shall prescribe requirements for recipients concerning the use and disposition of real property acquired in whole or in part...

15 CFR 14.32 - Real property.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Real property. 14.32 Section 14.32... ORGANIZATIONS Post-Award Requirements Property Standards § 14.32 Real property. The DoC award shall prescribe requirements for recipients concerning the use and disposition of real property acquired in whole or in part...

15 CFR 14.32 - Real property.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Real property. 14.32 Section 14.32... ORGANIZATIONS Post-Award Requirements Property Standards § 14.32 Real property. The DoC award shall prescribe requirements for recipients concerning the use and disposition of real property acquired in whole or in part...

78 FR 43197 - Revisions to Electric Quarterly Report Filing Process; Notice of Availability of Sandbox...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-19

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. RM12-3-000] Revisions to Electric Quarterly Report Filing Process; Notice of Availability of Sandbox Electronic Test Site Take notice that a Sandbox Electronic Test Site (ETS) and instructions have been posted on the Commission's Web site at http://www.ferc.gov/docs-filing...

Perceptions of Peer Review Using Cloud-Based Software

ERIC Educational Resources Information Center

Andrichuk, Gjoa

2016-01-01

This study looks at the change in perception regarding the effect of peer feedback on writing skills using cloud-based software. Pre- and post-surveys were given. The students peer reviewed drafts of five sections of scientific reports using Google Docs. While students reported that they did not perceive their writing ability improved by being…

Post-Traumatic Stress Disorder (PTSD)

MedlinePlus

... Information RePORT NIH Fact Sheets Home > Post-Traumatic Stress Disorder (PTSD) Small Text Medium Text Large Text Post-Traumatic Stress Disorder (PTSD) Post-traumatic stress disorder (PTSD) is ...

Population pharmacokinetics of paracetamol across the human age-range from (pre)term neonates, infants, children to adults.

PubMed

Wang, Chenguang; Allegaert, Karel; Tibboel, Dick; Danhof, Meindert; van der Marel, Caroline D; Mathot, Ron A A; Knibbe, Catherijne A J

2014-06-01

In order to characterize the variation in pharmacokinetics of paracetamol across the human age span, we performed a population pharmacokinetic analysis from preterm neonates to adults with specific focus on clearance. Concentration-time data obtained in 220 neonates (post-natal age 1-76 days, gestational age 27-42 weeks), infants (0.11-1.33 yrs), children (2-7 yrs) and adults (19-34 yrs) were analyzed using NONMEM 7.2. In the covariate analysis, linear functions, power functions, and a power function with a bodyweight-dependent exponent were tested. Between preterm neonates and adults, linear bodyweight functions were identified for Q2, Q3, V1, V2, and V3, while for CL a power function with a bodyweight-dependent exponent k was identified (CLi  = CLp  × (BW/70)(k) ). The exponent k was found to decrease in a sigmoidal manner with bodyweight from 1.2 to 0.75, with half the decrease in exponent reached at 12.2 kg. No other covariates such as age were identified. A pharmacokinetic model for paracetamol characterizing changes in pharmacokinetic parameters across the pediatric age-range was developed. Clearance was found to change in a nonlinear manner with bodyweight. Based on the final model, dosing guidelines are proposed from preterm neonates to adolescents resulting in similar exposure across all age ranges. © 2014, The American College of Clinical Pharmacology.

Risk factors for childhood asthma deaths from the UK Eastern Region Confidential Enquiry 2001-2006.

PubMed

Anagnostou, Katherine; Harrison, Brian; Iles, Richard; Nasser, Shuaib

2012-03-01

Confidential enquiries into asthma deaths can identify inadequacies in medical management and factors which contribute to patients' death. To identify risk factors for paediatric asthma deaths over a 6-year period. Observational case-series study of paediatric asthma deaths between 2001-2006 in the UK Eastern Region. Hospital, primary care and post-mortem data were obtained for every child (≤17 yrs) with asthma recorded on the death certificate, and a detailed questionnaire was completed. Information was obtained on asthma severity, medications, hospital admissions, GP and hospital follow-up, adherence, psychosocial / behavioural factors, allergies, details of the terminal attack and precipitating factors. 20 children (10 male; 8-17 yrs; median: 11.5 yrs) died of asthma between 2001-2006. 9/20 had mild to moderate asthma (BTS/ SIGN criteria), 10/20 had severe asthma and 1 child was not known to have asthma. 13/20 were clinically atopic. Only 3 had undergone allergy assessment. 10/20 died between June and August. 12/20 children had adverse psychosocial and behavioural factors. 7/20 children were on non-combination long-acting β2-agonist (LABA) treatment without inhaled corticosteroids (ICS). Almost half the deaths occurred in children with mild/moderate asthma. We recommend that allergic factors and seasonal allergy should be identified early, non-combination LABAs avoided, and speculate that overuse of short-acting β2-agonists (SABAs) may indicate non-adherence with ICS. Asthma deaths in children can be avoided if risk factors are identified early.

Post-exercise ketosis.

PubMed Central

Koeslag, J H; Noakes, T D; Sloan, A W

1980-01-01

1. The effect of exercise on blood ketone body concentrations was studied in trained athletes and in sedentary subjects pedalling a bicycle ergometer. 2. Although the untrained subjects had higher heart rates and blood lactate concentrations at the same work load as the athletes, neither group developed ketonaemia even after intense or prolonged exercise. 3. Older subjects developed post-exercise ketonaemia, reaching maximum about 3 hr after exercise. 4. A high-carbohydrate diet before the exercise could prevent the onset of post-exercise ketonaemia and a low-carbohydrate diet enhanced it. The highest post-exercise blood ketone levels were recorded in marathon runners after a "glycogen-stripping' regimen. 5. Concentrations of free fatty acids, glucose, growth hormone and insulin in blood after exercise followed different patterns from that of ketones. 6. Post-exercise ketosis, when it occurs in untrained subjects, may be due to a lower carbohydrate intake than that of athletes. PMID:6997456

Using the HDI camera with Tohono O’odham Tribal Community College Students

NASA Astrophysics Data System (ADS)

Garmany, Catharine D.

2017-01-01

Tohono O’odham Community College is a small two-year tribal college, located at the foot of I'oligam Du'ag, also known as Kitt Peak. In recognition and appreciation of Kitt Peak National Observatory’s location on the Tohono O’odham reservation, NOAO has worked with the college to offer an introduction astronomy class when requested. The class has been taught by NOAO scientific staff and post docs, and the lab component of this 4-credit class has been carried out at Kitt Peak. With support from the WIYN0.9-m Consortium, students have been able to observe on the 0.9m telescope. Most recently they have used the HDI camera for an evening, which has been a highlight of the class that students always note in their final evaluation. I will describe challenges and rewards in developing and maintaining this class, including identifying post docs and graduate students who are able to teach it. However, we feel the challenges are worth it: this may be the only formal astronomy class offered at a tribal college.

Research groups: How big should they be?

PubMed

Cook, Isabelle; Grange, Sam; Eyre-Walker, Adam

2015-01-01

Understanding the relationship between scientific productivity and research group size is important for deciding how science should be funded. We have investigated the relationship between these variables in the life sciences in the United Kingdom using data from 398 principle investigators (PIs). We show that three measures of productivity, the number of publications, the impact factor of the journals in which papers are published and the number of citations, are all positively correlated to group size, although they all show a pattern of diminishing returns-doubling group size leads to less than a doubling in productivity. The relationships for the impact factor and the number of citations are extremely weak. Our analyses suggest that an increase in productivity will be achieved by funding more PIs with small research groups, unless the cost of employing post-docs and PhD students is less than 20% the cost of a PI. We also provide evidence that post-docs are more productive than PhD students both in terms of the number of papers they produce and where those papers are published.

Proteogenemic Approaches for the Molecular Characterization of Natural Microbial Communities

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

Banfield, Jillian F.

2014-04-25

Microbial biofilms involved in acid mine drainage formation have served as a model systems for the study of microbial communities. Over the grant period we developed community metagenomic methods for recovery of genomes of uncultivated bacteria, archaea, viruses/phage, and plasmids from natural systems. We leveraged highly curated metagenomic datasets to develop methods to monitor microbial function in situ. Beyond new insight into extremophilic microbial ecosystems, we have shown that our strain-resolved proteogenomic methods can be applied to other systems. Our studies have uncovered new patters of inter-species recombination that likely lead to fine-scale environmental adaptation, defined the importance of inter-speciesmore » vs. intra-species recombination in archaea, and evaluated the processes shaping fine-scale sequence variation. The project was the subject of study for six Ph.D. students, two of whom are now Associate Professors, the others are post docs; for M.S. or undergraduate researchers, and thirteen post docs, ten of which are now Assistant or Associate professors. The research generated 53 publications, five of which appeard in Science or Nature.« less

Post-Exposure Prophylaxis

MedlinePlus

... gov Reason Number 87 to Get an HIV Test Veterans #DoingItMyWay – Testing for HIV June 27th is National HIV Testing Day Ryan White and HIV Testing Day 2018 Additional Resources AIDSInfo – Occupational Post-exposure Prophylaxis (PEP) Guidelines AIDSInfo – Nonoccupational Post-exposure ...

Dialysis outcomes in Colombia (DOC) study: a comparison of patient survival on peritoneal dialysis vs hemodialysis in Colombia.

PubMed

Sanabria, M; Muñoz, J; Trillos, C; Hernández, G; Latorre, C; Díaz, C S; Murad, S; Rodríguez, K; Rivera, A; Amador, A; Ardila, F; Caicedo, A; Camargo, D; Díaz, A; González, J; Leguizamón, H; Lopera, P; Marín, L; Nieto, I; Vargas, E

2008-04-01

The goal of the Dialysis Outcomes in Colombia (DOC) study was to compare the survival of patients on hemodialysis (HD) vs peritoneal dialysis (PD) in a network of renal units in Colombia. The DOC study examined a historical cohort of incident patients starting dialysis therapy between 1 January 2001 and 1 December 2003 and followed until 1 December 2005, measuring demographic, socioeconomic, and clinical variables. Only patients older than 18 years were included. As-treated and intention-to-treat statistical analyses were performed using the Kaplan-Meier method and Cox proportional hazard model. There were 1094 eligible patients in total and 923 were actually enrolled: 47.3% started HD therapy and 52.7% started PD therapy. Of the patients studied, 751 (81.3%) remained in their initial therapy until the end of the follow-up period, death, or censorship. Age, sex, weight, height, body mass index, creatinine, calcium, and Subjective Global Assessment (SGA) variables did not show statistically significant differences between the two treatment groups. Diabetes, socioeconomic level, educational level, phosphorus, Charlson Co-morbidity Index, and cardiovascular history did show a difference, and were less favorable for patients on PD. Residual renal function was greater for PD patients. Also, there were differences in the median survival time between groups: 27.2 months for PD vs 23.1 months for HD (P=0.001) by the intention-to-treat approach; and 24.5 months for PD vs 16.7 months for HD (P<0.001) by the as-treated approach. When performing univariate Cox analyses using the intention-to-treat approach, associations were with age > or =65 years (hazard ratio (HR)=2.21; confidence interval (CI) 95% (1.77-2.755); P<0.001); history of cardiovascular disease (HR=1.96; CI 95% (1.58-2.90); P<0.001); diabetes (HR=2.34; CI 95% (1.88-2.90); P<0.001); and SGA (mild or moderate-severe malnutrition) (HR=1.47; CI 95% (1.17-1.79); P=0.001); but no association was found with gender (HR=1

Stance and strategy: post-structural perspective and post-colonial engagement to develop nursing knowledge.

PubMed

Sochan, Anne M

2011-07-01

How should nursing knowledge advance? This exploration contextualizes its evolution past and present. In addressing how it evolved in the past, a probable historical evolution of its development draws on the perspectives of Frank & Gills's World System Theory, Kuhn's treatise on Scientific Revolutions, and Foucault's notions of Discontinuities in scientific knowledge development. By describing plausible scenarios of how nursing knowledge evolved, I create a case for why nursing knowledge developers should adopt a post-structural stance in prioritizing their research agenda(s). Further, by adopting a post-structural stance, I create a case on how nurses can advance their disciplinary knowledge using an engaging post-colonial strategy. Given an interrupted history caused by influence(s) constraining nursing's knowledge development by power structures external, and internal, to nursing, knowledge development can evolve in the future by drawing on post-structural interpretation, and post-colonial strategy. The post-structural writings of Deleuze & Guattari's understanding of 'Nomadology' as a subtle means to resist being constrained by existing knowledge development structures, might be a useful stance to understanding the urgency of why nursing knowledge should advance addressing the structural influences on its development. Furthermore, Bhabha's post-colonial elucidation of 'Hybridity' as an equally discreet means to change the culture of those constraining structures is an appropriate strategy to enact how nursing knowledge developers can engage with existing power structures, and simultaneously influence that engagement. Taken together, 'post-structural stance' and 'post-colonial strategy' can refocus nursing scholarship to learn from its past, in order to develop relevant disciplinary knowledge in its future. © 2011 Blackwell Publishing Ltd.

Functional near infrared spectroscopy as a probe of brain function in people with prolonged disorders of consciousness.

PubMed

Kempny, Agnieszka M; James, Leon; Yelden, Kudret; Duport, Sophie; Farmer, Simon; Playford, E Diane; Leff, Alexander P

2016-01-01

Near infrared spectroscopy (NIRS) is a non-invasive technique which measures changes in brain tissue oxygenation. NIRS has been used for continuous monitoring of brain oxygenation during medical procedures carrying high risk of iatrogenic brain ischemia and also has been adopted by cognitive neuroscience for studies on executive and cognitive functions. Until now, NIRS has not been used to detect residual cognitive functions in patients with prolonged disorders of consciousness (pDOC). In this study we aimed to evaluate the brain function of patients with pDOC by using a motor imagery task while recording NIRS. We also collected data from a group of age and gender matched healthy controls while they carried out both real and imagined motor movements to command. We studied 16 pDOC patients in total, split into two groups: five had a diagnosis of Vegetative state/Unresponsive Wakefulness State, and eleven had a diagnosis of Minimally Conscious State. In the control subjects we found a greater oxy-haemoglobin (oxyHb) response during real movement compared with imagined movement. For the between group comparison, we found a main effect of hemisphere, with greater depression of oxyHb signal in the right > left hemisphere compared with rest period for all three groups. A post-hoc analysis including only the two pDOC patient groups was also significant suggesting that this effect was not just being driven by the control subjects. This study demonstrates for the first time the feasibility of using NIRS for the assessment of brain function in pDOC patients using a motor imagery task.

Effects of Counseling on Psychological Measures in Caregivers of Patients with Disorders of Consciousness.

PubMed

Corallo, Francesco; Bonanno, Lilla; De Salvo, Simona; Giorgio, Antonio; Rifici, Carmela; Lo Buono, Viviana; Bramanti, Placido; Marino, Silvia

2015-11-01

Caregivers represent an important and potential resource in the care network of patients due to the amount of time dedicated to the patient and to their emotional involvement. The aim of this study was to evaluate the effectiveness of psychological support to families of patients with a disorder of consciousness (DOC). A total of 48 DOC caregivers were enrolled. Participants were randomly divided into 2 groups based upon the clinical condition of their family members (vegetative state [VS] versus minimally consciousness state [MCS]). Group 1 underwent psychological support and Group 2 was the control group. The 2 groups were evaluated at T0 (baseline) and at T1 (after 6 months). The Wilcoxon signed-rank test was used for within-group comparisons whereas the Mann-Whitney-U test was used to test for between-group differences. Results show how the psychological condition of caregivers in Group 1 was modified after the intervention by the healthcare team in the post-acute rehabilitative unit. Our data confirm that psychological support improves caregivers' ability to process the experience of DOC illness, independent of type of diagnosis.

Post-mortem clinical pharmacology

PubMed Central

Ferner, R E

2008-01-01

Clinical pharmacology assumes that deductions can be made about the concentrations of drugs from a knowledge of the pharmacokinetic parameters in an individual; and that the effects are related to the measured concentration. Post-mortem changes render the assumptions of clinical pharmacology largely invalid, and make the interpretation of concentrations measured in post-mortem samples difficult or impossible. Qualitative tests can show the presence of substances that were not present in life, and can fail to detect substances that led to death. Quantitative analysis is subject to error in itself, and because post-mortem concentrations vary in largely unpredictable ways with the site and time of sampling, as a result of the phenomenon of post-mortem redistribution. Consequently, compilations of ‘lethal concentrations’ are misleading. There is a lack of adequate studies of the true relationship between fatal events and the concentrations that can be measured subsequently, but without such studies, clinical pharmacologists and others should be wary of interpreting post-mortem measurements. PMID:18637886

32 CFR 643.120 - Post offices.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Post offices. 643.120 Section 643.120 National... Additional Authority of Commanders § 643.120 Post offices. Title 10 U.S.C. 4779b, provides that the SA shall assign suitable space for post office purposes at military posts where post offices have been established...

Low Frequency Predictive Skill Despite Structural Instability and Model Error

DTIC Science & Technology

2014-09-30

Majda, based on earlier theoretical work. 1. Dynamic Stochastic Superresolution of sparseley observed turbulent systems M. Branicki (Post doc...of numerical models. Here, we introduce and study a suite of general Dynamic Stochastic Superresolution (DSS) algorithms and show that, by...resolving subgridscale turbulence through Dynamic Stochastic Superresolution utilizing aliased grids is a potential breakthrough for practical online

Workshop on Energy Research for Physics Graduate Students and Postdocs

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

Cole, Ken

One-day workshop for a small group of graduate students and post-docs to hear talks and interact with experts in a variety of areas of energy research. The purpose is to provide an opportunity for young physicists to learn about cutting-edge research in which they might find a career utilizing their interest and background in physics.

Brady Stoll | NREL

Science.gov Websites

Renewable Generation Integration Study, she joined the laboratory full-time as a post doc and is now a lead determining the intensity and angular distribution of radiation transmitted through homogenous cloud cover ." Environmental Research Letters 8, no. 1 (March 2013). doi:10.1088/1748-9326/8/1/014042 Full list

MBBR evaluation for oil refinery wastewater treatment, with post-ozonation and BAC, for wastewater reuse.

PubMed

Schneider, E E; Cerqueira, A C F P; Dezotti, M

2011-01-01

This work evaluated the performance of a Moving Bed Biofilm Reactor (MBBR) in the treatment of an oil refinery wastewater. Also, it investigated the possibility of reuse of the MBBR effluent, after ozonation in series with a biological activated carbon (BAC) column. The best performance of the MBBR was achieved with a hydraulic retention time (HRT) of 6 hours, employing a bed to bioreactor volume ratio (V(B)/V(R)) of 0.6. COD and N-NH₄(+) MBBR effluent concentrations ranged from 40 to 75 mg L⁻¹ (removal efficiency of 69-89%) and 2 to 6 mg L⁻¹ (removal efficiency of 45-86%), respectively. Ozonation carried out for 15 min with an ozone concentration of 5 mg L⁻¹ was able to improve the treated wastewater biodegradability. The treatment performance of the BAC columns was practically the same for ozonated and non ozonated MBBR effluents. The dissolved organic carbon (DOC) content of the columns of the activated carbon columns (CAG) was in the range of 2.1-3.8 mg L⁻¹, and the corresponding DOC removal efficiencies were comprised between 52 and 75%. The effluent obtained at the end of the proposed treatment presented a quality, which meet the requirements for water reuse in the oil refinery.

[The post-mortal right of privacy].

PubMed

Jansen, Christoph

2008-01-01

Regarding the post-mortal right of privacy a distinction must be made between post-mortal protection of the personality, the post-mortal duty of confidentiality and the problems associated with the necessity to consent to a clinical post-mortem. The post-mortal protection of the personality both grants the post-mortal right to respect for privacy, which can be asserted by rights holder, and entitles to claim damages resulting from breach of any proprietary elements of the right to post-mortal privacy. The post-mortal duty of confidentiality protects against the unauthorized disclosure of confidential information about the patient even after his death. The physician has to decide whether the consent of the deceased may be presumed; however, he/she has to state the reasons why, due to medical confidentiality, he/she feels unable to disclose such information. Basically, the consent for clinical post-mortem can be effectively declared by way of a refusal clause in the hospital admission contract.

Post-Secularism, Religious Knowledge and Religious Education

ERIC Educational Resources Information Center

Carr, David

2012-01-01

Post-secularism seems to follow in the wake of other (what are here called) "postal" perspectives--post-structuralism, postmodernism, post-empiricism, post-positivism, post-analytical philosophy, post-foundationalism and so on--in questioning or repudiating what it takes to be the epistemic assumptions of "modernism." To be sure, post-secularism…

Influence of post pattern and resin cement curing mode on the retention of glass fibre posts.

PubMed

Poskus, L T; Sgura, R; Paragó, F E M; Silva, E M; Guimarães, J G A

2010-04-01

To evaluate the influence of post design and roughness and cement system (dual- or self-cured) on the retention of glass fibre posts. Two tapered and smooth posts (Exacto Cônico No. 2 and White Post No. 1) and two parallel-sided and serrated posts (Fibrekor 1.25 mm and Reforpost No. 2) were adhesively luted with two different resin cements--a dual-cured (Rely-X ARC) and a self-cured (Cement Post)--in 40 single-rooted teeth. The teeth were divided into eight experimental groups (n = 5): PFD--Parallel-serrated-Fibrekor/dual-cured; PRD--Parallel-serrated-Reforpost/dual-cured; TED--Tapered-smooth-Exacto Cônico/dual-cured; TWD--Tapered-smooth-White Post/dual-cured; PFS--Parallel-serrated-Fibrekor/self-cured; PRS--Parallel-serrated-Reforpost/self-cured; TES--Tapered-smooth-Exacto Cônico/self-cured; TWS--Tapered-smooth-White Post/self-cured. The specimens were submitted to a pull-out test at a crosshead speed of 0.5 mm min(-1). Data were analysed using analysis of variance and Bonferroni's multiple comparison test (alpha = 0.05). Pull-out results (MPa) were: PFD = 8.13 (+/-1.71); PRD = 8.30 (+/-0.46); TED = 8.68 (+/-1.71); TWD = 9.35 (+/-1.99); PFS = 8.54 (+/-2.23); PRS = 7.09 (+/-1.96); TES = 8.27 (+/-3.92); TWS = 7.57 (+/-2.35). No statistical significant difference was detected for posts and cement factors and their interaction. The retention of glass fibre posts was not affected by post design or surface roughness nor by resin cement-curing mode. These results imply that the choice for serrated posts and self-cured cements is not related to an improvement in retention.

[Fiber reinforced composite posts: literature review].

PubMed

Frydman, G; Levatovsky, S; Pilo, R

2013-07-01

FRC (Fiber-reinforced composite) posts have been used since the beginning of the 90s with the introduction of carbon fiber posts. Fiber posts are widely used to restore endodontically treated teeth that have insufficient coronal tooth structure. Many in vitro and in vivo studies have shown the advantage of using FRC over prefabricated and cast metal post especially indicated in narrow root canals which are prone to vertically root fracture. The most frequent failure of FRC is debonding of a post at the resin cement/dentin interface. Bonding to dentin may be achieved by using etch-and-rinse and self-etch adhesives. The bond strength formed by self-adhesive cements is noticeably lower in comparison to the bond strength formed with resin cements applied in combination with etch-and-rinse adhesives. In an attempt to maximize resin bonding to fiber posts, several surface treatments have been suggested. Sandblasting with alumina particles results in an increased surface roughness and surface area without affecting the integrity of the post as long as it is applied by 50 microm alumina particles at 2.5 bars for maximally 5 seconds at a distance of 30 mm. The efficiency of post salinization is controversial and its contribution to the retention is of minor importance. Hydrofluoric acid has recently been proposed for etching glass fiber posts but this technique produced substantial damage to the glass fibers and affected the integrity of the post. Delayed cementation of fiber post (at least 24h post endodontic treatment) resulted in higher retentive strengths in comparison to immediate cementation and the best results were obtained when the luting agent was brought into the post space with lentulo spirals or specific syringes. The resin cement film thickness also influences the pullout strengths of fiber-reinforced posts .The highest bond strength values were obtained when the cement layer oversized the post spaces but not larger than 0.3 mm. The use of core build

Age, altitude, and workload effects on complex performance.

DOT National Transportation Integrated Search

1983-09-01

Fifteen healthy men in each of three age groups, 20-29 yrs, 40-49 yrs, and 60-69 yrs, were evaluated regarding complex performance in two altitude conditions (ground level vs. 3,810 m) which were administered during performance testing. Performance w...

In vitro evaluation of endodontic posts.

PubMed

Drummond, J L

2000-05-01

To compare stainless steel posts and three different fibrous posts with respect to pullout (shear) strength from extracted third molars embedded in denture acrylic. Post space was prepared and the posts cemented with a resin cement according to manufacturer's instructions. Single step and multi-step dentin bonding systems were also evaluated. The testing was in tension at a loading rate of 2 mm/min. The statistical analysis indicated no significant difference in the pullout (shear) strength between any of the post groups tested. Also evaluated was the flexure strength of the fibrous posts before and after thermal cycling. Statistical analysis indicated a significant decrease in flexure strength for the respective fibrous posts following thermal cycling.

MRO DKF Post-Processing Tool

NASA Technical Reports Server (NTRS)

Ayap, Shanti; Fisher, Forest; Gladden, Roy; Khanampompan, Teerapat

2008-01-01

This software tool saves time and reduces risk by automating two labor-intensive and error-prone post-processing steps required for every DKF [DSN (Deep Space Network) Keyword File] that MRO (Mars Reconnaissance Orbiter) produces, and is being extended to post-process the corresponding TSOE (Text Sequence Of Events) as well. The need for this post-processing step stems from limitations in the seq-gen modeling resulting in incorrect DKF generation that is then cleaned up in post-processing.

Factors affecting the cement-post interface.

PubMed

Zicari, F; De Munck, J; Scotti, R; Naert, I; Van Meerbeek, B

2012-03-01

To evaluate the effect of different factors on the push-out bond strength of glass fiber posts luted in simulated (standard) root canals using different composite cements. Three types of glass-fiber root-canal posts with a different matrix, namely an epoxy resin (RelyX post, 3M ESPE), a proprietary composite resin (FRC-Plus post, Ivoclar-Vivadent), and a methacrylate resin (GC post, GC), and three types of composite cements, namely an etch-and-rinse Bis-GMA-based (Variolink II, Ivoclar-Vivadent), a self-etch 10-MDP-based (Clearfil Esthetic Cement, Kuraray) and a self-adhesive (RelyX Unicem, 3M ESPE) cement, were tested. Posts were either left untreated (control), were treated with silane, or coated with silicated alumina particles (Cojet system, 3M ESPE). Posts were inserted up to 9-mm depth into composite CAD-CAM blocks (Paradigm, 3M ESPE) in order to solely test the strength of the cement-post interface, while excluding interference of the cement-dentin interface. After 1-week storage at 37 °C, three sections (coronal, middle, apical) of 2-mm thickness were subjected to a push-out bond-strength test. All three variables, namely the type of post, the composite cement and the post-surface pre-treatment, were found to significantly affect the push-out bond strength (p<0.001). Regarding the type of post, a significantly lower push-out bond strength was recorded for the FRC-Plus post (Ivoclar-Vivadent); regarding the composite cement, a significantly higher push-out bond strength was recorded for the self-adhesive cement Unicem (3M ESPE); and regarding the post-surface treatment, a significantly higher push-out bond strength was recorded when the post-surface was beforehand subjected to a Cojet (3M ESPE) combined sandblasting/silicatization surface pre-treatment. Many interactions between these three variables were found to be significant as well (p<0.001). Finally, the push-out bond strength was found to significantly reduce with depth from coronal to apical

Post-traumatic stress disorder

MedlinePlus

... medlineplus.gov/ency/article/000925.htm Post-traumatic stress disorder To use the sharing features on this page, please enable JavaScript. Post-traumatic stress disorder (PTSD) is a type of anxiety disorder . ...

[Post-mortem microbiology analysis].

PubMed

Fernández-Rodríguez, Amparo; Alberola, Juan; Cohen, Marta Cecilia

2013-12-01

Post-mortem microbiology is useful in both clinical and forensic autopsies, and allows a suspected infection to be confirmed. Indeed, it is routinely applied to donor studies in the clinical setting, as well as in sudden and unexpected death in the forensic field. Implementation of specific sampling techniques in autopsy can minimize the possibility of contamination, making interpretation of the results easier. Specific interpretation criteria for post-mortem cultures, the use of molecular diagnosis, and its fusion with molecular biology and histopathology have led to post-mortem microbiology playing a major role in autopsy. Multidisciplinary work involving microbiologists, pathologists, and forensic physicians will help to improve the achievements of post-mortem microbiology, prevent infectious diseases, and contribute to a healthier population. Crown Copyright © 2012. Published by Elsevier Espana. All rights reserved.

Circulating T-Regulatory Cells, Exercise and the Elite Adolescent Swimmer

PubMed Central

Wilson, Lori D.; Zaldivar, Frank P.; Schwindt, Christina D.; Wang-Rodriguez, Jessica; Cooper, Dan M.

2014-01-01

Brief high intensity exercise induces peripheral leukocytosis possibly leading to a higher incidence of allergic symptoms in athletes undergoing excessive training. We studied the exercise-induced alternation of circulating Tregs and FoxP3+ Tregs due to acute intense swim exercise in elite swimmers (n = 22, 12 males, age = 15.4 yrs). Twelve had prior or current rhinitis or asthma and 10 had no current or prior allergy or asthma. Circulating Tregs increased significantly (p < .001) following exercise (pre = 133 ± 11.2, post = 196 ± 17.6) as did FoxP3+ cells (pre = 44, post = 64 cells/µl). Increases in Tregs and FoxP3+ Tregs occurred to the same extent in both groups of adolescent swimmers. PMID:19827454

Effect of hypovolemia, infusion, and oral rehydration on plasma electrolytes, ADH, renin activity, and +G/z/ tolerance

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Brock, P. J.; Haines, R. F.; Rositano, S. A.; Montgomery, L. D.; Keil, L. C.

1977-01-01

Effects on plasma volume, electrolyte shifts, and +G(z) tolerance induced by: (1) blood withdrawal; (2) blood infusion; and (3) oral fluid intake, were determined at 0.5 G/min in centrifugation tests of six ambulatory male patients, aged 21 to 27 yrs. Hypovolemia induced by withdrawal of 400 ml blood, blood infusion followed by repeated centrifugation, effects of consuming an isotonic drink (0.9% NaCl) to achieve oral rehydration, and donning of red adaptation goggles were studied for effects on acceleration tolerance, pre-acceleration and post-acceleration plasma renin activity (PRA) and plasma vasopressin levels. No significant changes in post-acceleration PRA compared to pre-acceleration PRA were found, and administration of oral rehydration is found as effective as blood replacement in counteracting hypovolemic effects.

36 CFR 261.51 - Posting.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Posting. 261.51 Section 261.51 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS Prohibitions in Areas Designated by Order § 261.51 Posting. Posting is accomplished by: (a) Placing a copy of...

36 CFR 261.51 - Posting.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Posting. 261.51 Section 261.51 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS Prohibitions in Areas Designated by Order § 261.51 Posting. Posting is accomplished by: (a) Placing a copy of...

36 CFR 261.51 - Posting.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Posting. 261.51 Section 261.51 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS Prohibitions in Areas Designated by Order § 261.51 Posting. Posting is accomplished by: (a) Placing a copy of...

36 CFR 261.51 - Posting.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Posting. 261.51 Section 261.51 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS Prohibitions in Areas Designated by Order § 261.51 Posting. Posting is accomplished by: (a) Placing a copy of...

36 CFR 261.51 - Posting.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Posting. 261.51 Section 261.51 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS Prohibitions in Areas Designated by Order § 261.51 Posting. Posting is accomplished by: (a) Placing a copy of...

Rigidity and retention of root canal posts.

PubMed

Purton, D G; Chandler, N P; Love, R M

1998-03-28

To test the rigidity and the retention into roots of parallel root canal posts, one a spiral vented titanium post and the other a spiral serrated, hollow, stainless steel post. A serrated, stainless steel post was used as the control. A three-point bending test was used to test rigidity. To test retention, ten posts of each type were cemented into the roots of extracted teeth with a resin cement and the tensile loads required to remove them were compared using Student's t and Mann-Whitney U tests. The serrated stainless steel posts were significantly more rigid than either of the other types. The titanium posts and the stainless steel hollow posts were not significantly different in rigidity. The serrated, stainless steel posts were significantly better retained than either of the other types. The titanium posts showed greater retention than the hollow posts. Within the limits of the study the stainless steel, serrated posts were superior to the two newer types in terms of rigidity and retention into roots.

Does the degree of endocrine dyscrasia post-reproduction dictate post-reproductive lifespan? Lessons from semelparous and iteroparous species.

PubMed

Atwood, Craig S; Hayashi, Kentaro; Meethal, Sivan Vadakkadath; Gonzales, Tina; Bowen, Richard L

2017-02-01

Post-reproductive lifespan varies greatly among species; human post-reproductive lifespan comprises ~30-50% of their total longevity, while semelparous salmon and dasyurid marsupials post-reproductive lifespan comprises <4% of their total longevity. To examine if the magnitude of hypothalamic-pituitary-gonadal (HPG) axis dyscrasia at the time of reproductive senescence determines post-reproductive lifespan, we examined the difference between pre- and post-reproductive (1) circulating sex hormones and (2) the ratio of sex steroids to gonadotropins (e.g., 17β-estradiol/follicle-stimulating hormone (FSH)), an index of the dysregulation of the HPG axis and the level of dyotic (death) signaling post-reproduction. Animals with a shorter post-reproductive lifespan (<4% total longevity) had a more marked decline in circulating sex steroids and corresponding elevation in gonadotropins compared to animals with a longer post-reproductive lifespan (30-60% total longevity). In semelparous female salmon of short post-reproductive lifespan (1%), these divergent changes in circulating hormone concentration post-reproduction equated to a 711-fold decrease in the ratio of 17β-estradiol/FSH between the reproductive and post-reproductive periods. In contrast, the decrease in the ratio of 17β-estradiol/FSH in iteroparous female mammals with long post-reproductive lifespan was significantly less (1.7-34-fold) post-reproduction. Likewise, in male semelparous salmon, the decrease in the ratio of testosterone/FSH (82-fold) was considerably larger than for iteroparous species (1.3-11-fold). These results suggest that (1) organisms with greater reproductive endocrine dyscrasia more rapidly undergo senescence and die, and (2) the contribution post-reproduction by non-gonadal (and perhaps gonadal) tissues to circulating sex hormones dictates post-reproductive tissue health and longevity. In this way, reproduction and longevity are coupled, with the degree of non-gonadal tissue hormone