WorldWideScience

Sample records for primary nutrient source

  1. Microalgae biomass growth using primary treated wastewater as nutrient source and their potential use for lipids production

    Science.gov (United States)

    Frementiti, Anastacia; Aravantinou, Andriana F.; Manariotis, Ioannis D.

    2015-04-01

    The great demand for energy, the rising price of the crude oil and the rapid decrease of the supply of fossil fuels are the main reasons that have increased the interest for the production of fuels from renewable resources. Microalgae are considered to be the most promising new source of biomass and biofuels, since their lipid content in some cases is up to 70%. The microalgal growth and its metabolism processes are essential in wastewater treatment with many economical prospects. The aim of this work was to evaluate the algal production in a laboratory scale open pond. The pond had a working volume of 30 L and was fed with sterilized primary treated wastewater. Chlorococcum sp. was used as a model microalgal. Experiments were conducted under controlled environmental conditions in order to investigate the removal of nutrients, biomass growth, and lipids accumulation in microalgae. Chlorococcum sp. cultures behavior was investigated under batch, fill and draw, and continuous operation mode, at two different radiation intensities (100 and 200 μmol/m2s). The maximum biomass concentration of 630 mg/L was observed with the fill and draw mode. Moreover, the growth rates of microalgal biomass were depended on the influent nutrients concentration. Specifically, the phosphates were the limiting factor for biomass growth in continuous condition; the phosphates removal in this condition, reached a 100%. Chemical demand oxygen (COD) was not removed efficiently by Chlorococcum sp. since it was an autotrophic microalgal with no organic carbon demands for its growth. The lipids content in the dry weight of Chlorococcum sp. ranged from 1 to 9% depending on the concentration of nutrients and the operating conditions.

  2. Investigating Primary Source Literacy

    Science.gov (United States)

    Archer, Joanne; Hanlon, Ann M.; Levine, Jennie A.

    2009-01-01

    Primary source research requires students to acquire specialized research skills. This paper presents results from a user study testing the effectiveness of a Web guide designed to convey the concepts behind "primary source literacy". The study also evaluated students' strengths and weaknesses when conducting primary source research. (Contains 3…

  3. Distribution of nutrients, chlorophyll and phytoplankton primary ...

    African Journals Online (AJOL)

    Distribution of nutrients, chlorophyll and phytoplankton primary production in ... Two cruises were undertaken in the vicinity of the Cape Frio upwelling cell ... and concentrations of nitrate, phosphate, silicate, oxygen and chlorophyll a. ... Estimates of the annual primary production for each of the water bodies were calculated.

  4. Using Primary Source Documents.

    Science.gov (United States)

    Mintz, Steven

    2003-01-01

    Explores the use of primary sources when teaching about U.S. slavery. Includes primary sources from the Gilder Lehrman Documents Collection (New York Historical Society) to teach about the role of slaves in the Revolutionary War, such as a proclamation from Lord Dunmore offering freedom to slaves who joined his army. (CMK)

  5. Submarine groundwater discharge as an important nutrient source influencing nutrient structure in coastal water of Daya Bay, China

    Science.gov (United States)

    Wang, Xuejing; Li, Hailong; Zheng, Chunmiao; Yang, Jinzhong; Zhang, Yan; Zhang, Meng; Qi, Zhanhui; Xiao, Kai; Zhang, Xiaolang

    2018-03-01

    As an important nutrient source for coastal waters, submarine groundwater discharge (SGD) has long been largely ignored in Daya Bay, China. In this study, we estimate the fluxes of SGD and associated nutrients into this region using a 224Ra mass balance model and assess the contribution/importance of nutrients by SGD, benthic sediments, local rivers, and atmospheric deposition. The results of 224Ra mass balance show that the estimated SGD ranges from (2.76 ± 1.43) × 106 m3/d to (1.03 ± 0.53) × 107 m3/d with an average of (6.32 ± 2.42) × 106 m3/d, about 16 times the total discharge rate of local rivers. The nutrient loading from SGD is estimated to be (1.05-1.99) × 105 mol/d for NO3-N, (4.04-12.16) × 103 mol/d for DIP, and (3.54-11.35) × 105 mol/d for Si. Among these considered nutrient sources, we find that SGD is the primary source for Si and NO3-N, contributing 68% and 42% of all considered sources, respectively. The atmospheric NO3-N flux is comparable to that from SGD. The local rivers are the most important source for DIP, contributing 75% of all considered sources. SGD with high N:P ratio (NO3-N/DIP) of 37.0 delivers not only a large quantity of nutrients, but also changes nutrient structure in coastal water. Based on a DIP budget, primary productivity is evaluated to be 54-73 mg C/m2 d, in which SGD accounts for approximately 30% of total production. This study indicates that SGD is a key source of nutrients to coastal waters and may cause an obvious change of primary production and nutrient structure in Daya Bay.

  6. Nitrogenous nutrients and primary production in a tropical oceanic environment

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.; Wafar, S.; Devassy, V.P.

    Measurements of the concentrations of nitrogenous nutrients and primary production were made at 10 stations along 8 degrees N and 10 degrees N in the tropical oceanic Lakshadweep waters Inorganic nitrogen (NO3, NO2 and NH4) accounted for less than...

  7. Anthropogenic nutrient sources rival natural sources on small scales in the coastal waters of the Southern California Bight

    KAUST Repository

    Howard, Meredith D. A.

    2014-01-26

    Anthropogenic nutrients have been shown to provide significant sources of nitrogen (N) that have been linked to increased primary production and harmful algal blooms worldwide. There is a general perception that in upwelling regions, the flux of anthropogenic nutrient inputs is small relative to upwelling flux, and therefore anthropogenic inputs have relatively little effect on the productivity of coastal waters. To test the hypothesis that natural sources (e.g., upwelling) greatly exceed anthropogenic nutrient sources to the Southern California Bight (SCB), this study compared the source contributions of N from four major nutrient sources: (1) upwelling, (2) treated wastewater effluent discharged to ocean outfalls, (3) riverine runoff, and (4) atmospheric deposition. This comparison was made using large regional data sets combined with modeling on both regional and local scales. At the regional bight-wide spatial scale, upwelling was the largest source of N by an order of magnitude to effluent and two orders of magnitude to riverine runoff. However, at smaller spatial scales, more relevant to algal bloom development, natural and anthropogenic contributions were equivalent. In particular, wastewater effluent and upwelling contributed the same quantity of N in several subregions of the SCB. These findings contradict the currently held perception that in upwelling-dominated regions anthropogenic nutrient inputs are negligible, and suggest that anthropogenic nutrients, mainly wastewater effluent, can provide a significant source of nitrogen for nearshore productivity in Southern California coastal waters.

  8. Anthropogenic nutrient sources rival natural sources on small scales in the coastal waters of the Southern California Bight

    KAUST Repository

    Howard, Meredith D. A.; Sutula, Martha; Caron, David A.; Chao, Yi; Farrara, John D.; Frenzel, Hartmut; Jones, Burton; Robertson, George; McLaughlin, Karen; Sengupta, Ashmita

    2014-01-01

    Anthropogenic nutrients have been shown to provide significant sources of nitrogen (N) that have been linked to increased primary production and harmful algal blooms worldwide. There is a general perception that in upwelling regions, the flux of anthropogenic nutrient inputs is small relative to upwelling flux, and therefore anthropogenic inputs have relatively little effect on the productivity of coastal waters. To test the hypothesis that natural sources (e.g., upwelling) greatly exceed anthropogenic nutrient sources to the Southern California Bight (SCB), this study compared the source contributions of N from four major nutrient sources: (1) upwelling, (2) treated wastewater effluent discharged to ocean outfalls, (3) riverine runoff, and (4) atmospheric deposition. This comparison was made using large regional data sets combined with modeling on both regional and local scales. At the regional bight-wide spatial scale, upwelling was the largest source of N by an order of magnitude to effluent and two orders of magnitude to riverine runoff. However, at smaller spatial scales, more relevant to algal bloom development, natural and anthropogenic contributions were equivalent. In particular, wastewater effluent and upwelling contributed the same quantity of N in several subregions of the SCB. These findings contradict the currently held perception that in upwelling-dominated regions anthropogenic nutrient inputs are negligible, and suggest that anthropogenic nutrients, mainly wastewater effluent, can provide a significant source of nitrogen for nearshore productivity in Southern California coastal waters.

  9. Carbon footprint of urban source separation for nutrient recovery.

    Science.gov (United States)

    Kjerstadius, H; Bernstad Saraiva, A; Spångberg, J; Davidsson, Å

    2017-07-15

    Source separation systems for the management of domestic wastewater and food waste has been suggested as more sustainable sanitation systems for urban areas. The present study used an attributional life cycle assessment to investigate the carbon footprint and potential for nutrient recovery of two sanitation systems for a hypothetical urban area in Southern Sweden. The systems represented a typical Swedish conventional system and a possible source separation system with increased nutrient recovery. The assessment included the management chain from household collection, transport, treatment and final return of nutrients to agriculture or disposal of the residuals. The results for carbon footprint and nutrient recovery (phosphorus and nitrogen) concluded that the source separation system could increase nutrient recovery (0.30-0.38 kg P capita -1 year -1 and 3.10-3.28 kg N capita -1 year -1 ), while decreasing the carbon footprint (-24 to -58 kg CO 2 -eq. capita -1 year -1 ), compared to the conventional system. The nutrient recovery was increased by the use of struvite precipitation and ammonium stripping at the wastewater treatment plant. The carbon footprint decreased, mainly due to the increased biogas production, increased replacement of mineral fertilizer in agriculture and less emissions of nitrous oxide from wastewater treatment. In conclusion, the study showed that source separation systems could potentially be used to increase nutrient recovery from urban areas, while decreasing the climate impact. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Primary Sources and Inquiry Learning

    Science.gov (United States)

    Pappas, Marjorie L.

    2006-01-01

    In this article, the author discusses inquiry learning and primary sources. Inquiry learning puts students in the active role of investigators. Questioning, authentic and active learning, and interactivity are a few of the characteristics of inquiry learning that put the teacher and library media specialist in the role of coaches while students…

  11. Potash—A vital agricultural nutrient sourced from geologic deposits

    Science.gov (United States)

    Yager, Douglas B.

    2016-11-15

    This report summarizes the primary sources of potash in the United States. Potash is an essential nutrient that, along with phosphorus and nitrogen, is used as fertilizer for growing crops. Plants require sufficient potash to activate enzymes, which in turn catalyze chemical reactions important for water uptake and photosynthesis. When potassium is available in quantities necessary for healthy plant growth, disease resistance and physical quality are improved and crop yield and shelf life are increased. Potash is a water-soluble compound of potassium formed by geologic and hydrologic processes. The principal potash sources discussed are the large, stratiform deposits that formed during retreat and evaporation of intracontinental seas. The Paradox, Delaware, Holbrook, Michigan, and Williston sedimentary basins in the United States are examples where extensive potash beds were deposited. Ancient marine-type potash deposits that are close to the surface can be mined using conventional underground mining methods. In situ solution mining can be used where beds are too deep, making underground mining cost-prohibitive, or where underground mines are converted to in situ solution mines. Quaternary brine is another source of potash that is recovered by solar evaporation in manmade ponds. Groundwater from Pleistocene Lake Bonneville (Wendover, Utah) and the present-day Great Salt Lake in Utah are sources of potashbearing brine. Brine from these sources pumped to solar ponds is evaporated and potash concentrated for harvesting, processing, and refinement. Although there is sufficient potash to meet near-term demand, the large marine-type deposits are either geographically restricted to a few areas or are too deep to easily mine. Other regions lack sources of potash brine from groundwater or surface water. Thus, some areas of the world rely heavily on potash imports. Political, economic, and global population pressures may limit the ability of some countries from securing

  12. Food Sources of Energy and Nutrients among Adults in the US: NHANES 2003–2006

    Directory of Open Access Journals (Sweden)

    Theresa A. Nicklas

    2012-12-01

    Full Text Available Identification of current food sources of energy and nutrients among US adults is needed to help with public health efforts to implement feasible and appropriate dietary recommendations. To determine the food sources of energy and 26 nutrients consumed by US adults the 2003–2006 National Health and Nutrition Examination Survey (NHANES 24-h recall (Day 1 dietary intake data from a nationally representative sample of adults 19+ years of age (y (n = 9490 were analyzed. An updated USDA Dietary Source Nutrient Database was developed for NHANES 2003–2006 using current food composition databases. Food grouping included ingredients from disaggregated mixtures. Mean energy and nutrient intakes from food sources were sample-weighted. Percentages of total dietary intake contributed from food sources were ranked. The highest ranked sources of energy and nutrients among adults more than 19 years old were: energy — yeast bread/rolls (7.2% and cake/cookies/quick bread/pastry/pie (7.2%; protein—poultry (14.4% and beef (14.0%; total fat — other fats and oils (9.8%; saturated fatty acids — cheese (16.5% and beef (9.1%; carbohydrate — soft drinks/soda (11.4% and yeast breads/rolls (10.9%; dietary fiber — yeast breads/rolls (10.9% and fruit (10.2%; calcium — milk (22.5% and cheese (21.6%; vitamin D — milk (45.1% and fish/shellfish (14.4%; and potassium — milk (9.6% and coffee/tea/other non-alcoholic beverages (8.4%. Knowledge of primary food sources of energy and nutrients can help health professionals design effective strategies to reduce excess energy consumed by US adults and increase the nutrient adequacy of their diets.

  13. Food Sources of Energy and Nutrients among Adults in the US: NHANES 2003–2006

    Science.gov (United States)

    O’Neil, Carol E.; Keast, Debra R.; Fulgoni, Victor L.; Nicklas, Theresa A.

    2012-01-01

    Identification of current food sources of energy and nutrients among US adults is needed to help with public health efforts to implement feasible and appropriate dietary recommendations. To determine the food sources of energy and 26 nutrients consumed by US adults the 2003–2006 National Health and Nutrition Examination Survey (NHANES) 24-h recall (Day 1) dietary intake data from a nationally representative sample of adults 19+ years of age (y) (n = 9490) were analyzed. An updated USDA Dietary Source Nutrient Database was developed for NHANES 2003–2006 using current food composition databases. Food grouping included ingredients from disaggregated mixtures. Mean energy and nutrient intakes from food sources were sample-weighted. Percentages of total dietary intake contributed from food sources were ranked. The highest ranked sources of energy and nutrients among adults more than 19 years old were: energy—yeast bread/rolls (7.2%) and cake/cookies/quick bread/pastry/pie (7.2%); protein—poultry (14.4%) and beef (14.0%); total fat—other fats and oils (9.8%); saturated fatty acids—cheese (16.5%) and beef (9.1%); carbohydrate—soft drinks/soda (11.4%) and yeast breads/rolls (10.9%); dietary fiber—yeast breads/rolls (10.9%) and fruit (10.2%); calcium—milk (22.5%) and cheese (21.6%); vitamin D—milk (45.1%) and fish/shellfish (14.4%); and potassium—milk (9.6%) and coffee/tea/other non-alcoholic beverages (8.4%). Knowledge of primary food sources of energy and nutrients can help health professionals design effective strategies to reduce excess energy consumed by US adults and increase the nutrient adequacy of their diets. PMID:23363999

  14. Food sources of energy and nutrients among adults in the US: NHANES 2003–2006.

    Science.gov (United States)

    O'Neil, Carol E; Keast, Debra R; Fulgoni, Victor L; Nicklas, Theresa A

    2012-12-19

    Identification of current food sources of energy and nutrients among US adults is needed to help with public health efforts to implement feasible and appropriate dietary recommendations. To determine the food sources of energy and 26 nutrients consumed by US adults the 2003-2006 National Health and Nutrition Examination Survey (NHANES) 24-h recall (Day 1) dietary intake data from a nationally representative sample of adults 19+ years of age (y) (n = 9490) were analyzed. An updated USDA Dietary Source Nutrient Database was developed for NHANES 2003-2006 using current food composition databases. Food grouping included ingredients from disaggregated mixtures. Mean energy and nutrient intakes from food sources were sample-weighted. Percentages of total dietary intake contributed from food sources were ranked. The highest ranked sources of energy and nutrients among adults more than 19 years old were: energy - yeast bread/rolls (7.2%) and cake/cookies/quick bread/pastry/pie (7.2%); protein-poultry (14.4%) and beef (14.0%); total fat - other fats and oils (9.8%); saturated fatty acids - cheese (16.5%) and beef (9.1%); carbohydrate - soft drinks/soda (11.4%) and yeast breads/rolls (10.9%); dietary fiber - yeast breads/rolls (10.9%) and fruit (10.2%); calcium - milk (22.5%) and cheese (21.6%); vitamin D - milk (45.1%) and fish/shellfish (14.4%); and potassium - milk (9.6%) and coffee/tea/other non-alcoholic beverages (8.4%). Knowledge of primary food sources of energy and nutrients can help health professionals design effective strategies to reduce excess energy consumed by US adults and increase the nutrient adequacy of their diets.

  15. CADDIS Volume 2. Sources, Stressors and Responses: Nutrients

    Science.gov (United States)

    Introduction to the nutrients module, when to list nutrients as a candidate cause, ways to measure nutrients, simple and detailed conceptual diagrams for nutrients, nutrients module references and literature reviews.

  16. Classification of nutrient emission sources in the Vistula River system

    International Nuclear Information System (INIS)

    Kowalkowski, Tomasz

    2009-01-01

    Eutrophication of the Baltic sea still remains one of the biggest problems in the north-eastern area of Europe. Recognizing the sources of nutrient emission, classification of their importance and finding the way towards reduction of pollution are the most important tasks for scientists researching this area. This article presents the chemometric approach to the classification of nutrient emission with respect to the regionalisation of emission sources within the Vistula River basin (Poland). Modelled data for mean yearly emission of nitrogen and phosphorus in 1991-2000 has been used for the classification. Seventeen subcatchements in the Vistula basin have been classified according to cluster and factor analyses. The results of this analysis allowed determination of groups of areas with similar pollution characteristics and indicate the need for spatial differentiation of policies and strategies. Three major factors indicating urban, erosion and agricultural sources have been identified as major discriminants of the groups. - Two classification methods applied to evaluate the results of nutrient emission allow definition of major sources of the emissions and classification of catchments with similar pollution.

  17. Nontronite and Montmorillonite as Nutrient Sources for Life on Mars

    Science.gov (United States)

    Craig, P. I.; Mickol, R. L.; Archer, P. D.; Kral, T. A.

    2017-01-01

    Clay minerals have been identified on Mars' oldest (Noachian) terrain and their presence suggests long-term water-rock interactions. The most commonly identified clay minerals on Mars to date are nontronite (Fe-smectite) and montmorillonite (Al-smectite) [1], both of which contain variable amounts of water both adsorbed on their surface and within their structural layers. Over Mars' history, these clay miner-al-water assemblages may have served as nutrient sources for microbial life.

  18. Insects - a natural nutrient source for poultry - a review

    OpenAIRE

    Józefiak, D; Josefiak, A; Kieronczyk, B; Rawski, M; Swiatkiewicz, S; Dlugosz, Jakub; Engberg, Ricarda Greuel

    2016-01-01

    The consumption of poultry meat and eggs is expected to increase considerably in the nearest future, which creates the demand for new poultry feed ingredients in order to support sustainable intensive production. Moreover, the constant improvement of the genetic potential of poultry has resulted in an increased nutrient density in poultry feeds, which limits the possibility to include low quality feed ingredients. Therefore, the feed industry needs new sources of highly digestible protein wit...

  19. Study of nonpoint source nutrient loading in the Patuxent River basin, Maryland

    Science.gov (United States)

    Preston, S.D.

    1997-01-01

    Study of nonpoint-source (NPS) nutrient loading in Maryland has focused on the Patuxent watershed because of its importance and representativeness of conditions in the State. Evaluation of NPS nutrient loading has been comprehensive and has included long-term monitoring, detailed watershed modeling, and synoptic sampling studies. A large amount of information has been compiled for the watershed and that information is being used to identify primary controls and efficient management strategies for NPS nutrient loading. Results of the Patuxent NPS study have identified spatial trends in water quality that appear to be related to basin charcteristics such as land use, physiography, andgeology. Evaluation of the data compiled by the study components is continuing and is expected to provide more detailed assessments of the reasons for spatial trends. In particular, ongoing evaluation of the watershed model output is expected to provide detailed information on the relative importance of nutrient sources and transport pathways across the entire watershed. Planned future directions of NPS evaluation in the State of Maryland include continued study of water quality in the Patuxent watershed and a shift in emphasis to a statewide approach. Eventually, the statewide approach will become the primary approach usedby the State to evaluate NPS loading. The information gained in the Patuxent study and the tools developed will represent valuable assets indeveloping the statewide NPS assessment program.

  20. A Conceptual Framework for Primary Source Practices

    Science.gov (United States)

    Ensminger, David C.; Fry, Michelle L.

    2012-01-01

    This article introduces a descriptive conceptual framework to provide teachers with a means of recognizing and describing instructional activities that use primary sources. The framework provides structure for professional development programs that have been established to train teachers to access and integrate primary sources into lessons. The…

  1. Nutrient limitation of primary productivity in the Southeast Pacific (BIOSOPE cruise

    Directory of Open Access Journals (Sweden)

    S. Bonnet

    2008-02-01

    Full Text Available Iron is an essential nutrient involved in a variety of biological processes in the ocean, including photosynthesis, respiration and dinitrogen fixation. Atmospheric deposition of aerosols is recognized as the main source of iron for the surface ocean. In high nutrient, low chlorophyll areas, it is now clearly established that iron limits phytoplankton productivity but its biogeochemical role in low nutrient, low chlorophyll environments has been poorly studied. We investigated this question in the unexplored southeast Pacific, arguably the most oligotrophic area of the global ocean. Situated far from any continental aerosol source, the atmospheric iron flux to this province is amongst the lowest of the world ocean. Here we report that, despite low dissolved iron concentrations (~0.1 nmol l−1 across the whole gyre (3 stations located in the center and at the western and the eastern edges, primary productivity are only limited by iron availability at the border of the gyre, but not in the center. The seasonal stability of the gyre has apparently allowed for the development of populations acclimated to these extreme oligotrophic conditions. Moreover, despite clear evidence of nitrogen limitation in the central gyre, we were unable to measure dinitrogen fixation in our experiments, even after iron and/or phosphate additions, and cyanobacterial nif H gene abundances were extremely low compared to the North Pacific Gyre. The South Pacific gyre is therefore unique with respect to the physiological status of its phytoplankton populations.

  2. Sources of Nutrients to Nearshore Areas of a Eutrophic Estuary: Implications for Nutrient-Enhanced Acidification in Puget Sound

    Science.gov (United States)

    Pacella, S. R.

    2016-02-01

    Ocean acidification has recently been highlighted as a major stressor for coastal organisms. Further work is needed to assess the role of anthropogenic nutrient additions in eutrophied systems on local biological processes, and how this interacts with CO2 emission-driven acidification. This study sought to distinguish changes in pH caused by natural versus anthropogenically affected processes. We quantified the variability in water column pH attributable to primary production and respiration fueled by anthropogenically derived nitrogen in a shallow nearshore area. Two study sites were located in shallow subtidal areas of the Snohomish River estuary, a eutrophic system located in central Puget Sound, Washington. These sites were chosen due to the presence of heavy agricultural activity, urbanized areas with associated waste water treatment, as well as influence from deep, high CO2 marine waters transported through the Strait of Juan de Fuca and upwelled into the area during spring and summer. Data was collected from July-December 2015 utilizing continuous moorings and discrete water column sampling. Analysis of stable isotopes, δ15N, δ18O-NO3, δ15N-NH4, was used to estimate the relative contributions of anthropogenic versus upwelled marine nitrogen sources. Continuous monitoring of pH, dissolved oxygen, temperature, and salinity was conducted at both study sites to link changes in nutrient source and availability with changes in pH. We predicted that isotope data would indicate greater contributions of nitrogen from agriculture and wastewater rather than upwelling in the shallow, nearshore study sites. This study seeks to distinguish the relative magnitude of pH change stimulated by anthropogenic versus natural sources of nitrogen to inform public policy decisions in critically important nearshore ecosystems.

  3. Biomass burning: A significant source of nutrients for Andean rainforests

    Science.gov (United States)

    Fabian, P. F.; Rollenbeck, R.; University Of Marburg, Germany

    2010-12-01

    Regular rain and fogwater sampling in the Podocarpus National Park,on the humid eastern slopes of the Ecuadorian Andes,has been carried out since 2002.The samples,accumulated over about 1-week intervals,were analysed for pH,conductivity,and major ions (K+, Na+, NH4+, Ca2+, Mg2+, Cl-, SO4 2-, NO3-, PO4 3- ).Annual deposition rates of these ions which, due to poor acidic soils with low mineralization rates,constitute the dominant nutrient supply to the mountaineous rainforests, and major ion sources could be determined using back trajectories,along with satellite data. While most of the Na, Cl, and K as well as Ca and Mg input was found to originate from natural oceanic and desert dust sources,respectively (P.Fabian et al.,Adv.Geosci.22,85-94, 2009), NO3, NH4, and about 90% of SO4 (about 10 % is from active volcanoes) are almost entirely due to anthropogenic sources,most likely biomass burning. Industrial and transportation emissions and other pollutants,however,act in a similar way as the precursors produced by biomass burning.For quantifying the impacts of biomass burning vs. those of anthropogenic sources other than biomass burning we used recently established emission inventories,along with simplified model calculations on back trajectories.First results yielding significant contributions of biomass burning will be discussed.

  4. Surface-water nutrient conditions and sources in the United States Pacific Northwest

    Science.gov (United States)

    Wise, D.R.; Johnson, H.M.

    2011-01-01

    The SPAtially Referenced Regressions On Watershed attributes (SPARROW) model was used to perform an assessment of surface-water nutrient conditions and to identify important nutrient sources in watersheds of the Pacific Northwest region of the United States (U.S.) for the year 2002. Our models included variables representing nutrient sources as well as landscape characteristics that affect nutrient delivery to streams. Annual nutrient yields were higher in watersheds on the wetter, west side of the Cascade Range compared to watersheds on the drier, east side. High nutrient enrichment (relative to the U.S. Environmental Protection Agency's recommended nutrient criteria) was estimated in watersheds throughout the region. Forest land was generally the largest source of total nitrogen stream load and geologic material was generally the largest source of total phosphorus stream load generated within the 12,039 modeled watersheds. These results reflected the prevalence of these two natural sources and the low input from other nutrient sources across the region. However, the combined input from agriculture, point sources, and developed land, rather than natural nutrient sources, was responsible for most of the nutrient load discharged from many of the largest watersheds. Our results provided an understanding of the regional patterns in surface-water nutrient conditions and should be useful to environmental managers in future water-quality planning efforts.

  5. Insects - a natural nutrient source for poultry - a review

    DEFF Research Database (Denmark)

    Józefiak, D; Josefiak, A; Kieronczyk, B

    2016-01-01

    , such as fishmeal. With estimated 1.5 to 3 million species, the class of insects harbours the largest species variety in the world including species providing a high protein and sulphur amino acids content, which can be successfully exploited as feed for poultry. The aim of this paper is to review the present state...... of knowledge concerning the use of insect protein in poultry nutrition and the possibilities of mass production of insects for the feed industry. There is no doubt that insects have an enormous potential as a source of nutrients (protein) and active substances (polyunsaturated fatty acids, antimicrobial...... peptides) for poultry. It can be concluded, based on many experimental results, that meals from insects being members of the orders Diptera (black soldier fly, housefly), Coleoptera (mealworms) and Orthoptera (grasshoppers, locust, crickets and katylids), may be successfully used as feed material...

  6. Treatment of Source-Separated Blackwater: A Decentralized Strategy for Nutrient Recovery towards a Circular Economy

    OpenAIRE

    Melesse Eshetu Moges; Daniel Todt; Arve Heistad

    2018-01-01

    Using a filter medium for organic matter removal and nutrient recovery from blackwater treatment is a novel concept and has not been investigated sufficiently to date. This paper demonstrates a combined blackwater treatment and nutrient-recovery strategy and establishes mechanisms for a more dependable source of plant nutrients aiming at a circular economy. Source-separated blackwater from a student dormitory was used as feedstock for a sludge blanket anaerobic-baffled reactor. The effluent f...

  7. Bring History Alive with Primary Sources

    Science.gov (United States)

    Lehman, Kathy

    2010-01-01

    Using primary sources such as a photograph from the Library of Congress American Memory collection engages learners to think about the past and relate it to their life today. Some artifacts come with an explanation, while some do not. These require critical thinking and investigation to locate information and hypothesize answers to questions posed…

  8. Analysis of primary teacher stress' sources

    Directory of Open Access Journals (Sweden)

    Katja Depolli Steiner

    2011-12-01

    Full Text Available Teachers are subject to many different work stressors. This study focused on differences in intensity and frequency of potential stressors facing primary schoolteachers and set the goal to identify the most important sources of teacher stress in primary school. The study included 242 primary schoolteachers from different parts of Slovenia. We used Stress Inventory that is designed for identification of intensity and frequency of 49 situations that can play the role of teachers' work stressors. Findings showed that the major sources of stress facing teachers are factors related to work overload, factors stemming from pupils' behaviour and motivation and factors related to school system. Results also showed some small differences in perception of stressors in different groups of teachers (by gender and by teaching level.

  9. Aerobic mineralization of selected organic nutrient sources for soil ...

    African Journals Online (AJOL)

    Administrator

    food synthesis (Lavelle and Spain, 2001). Multipurpose trees such .... The soil and organic nutrient resource ... treatments. Simple correlation analysis was carried out to measure ..... Germination Ecology of Two Endemic Multipurpose. Species ...

  10. Nutrient patterns and their food sources in an International Study Setting: report from the EPIC study.

    Science.gov (United States)

    Moskal, Aurelie; Pisa, Pedro T; Ferrari, Pietro; Byrnes, Graham; Freisling, Heinz; Boutron-Ruault, Marie-Christine; Cadeau, Claire; Nailler, Laura; Wendt, Andrea; Kühn, Tilman; Boeing, Heiner; Buijsse, Brian; Tjønneland, Anne; Halkjær, Jytte; Dahm, Christina C; Chiuve, Stephanie E; Quirós, Jose R; Buckland, Genevieve; Molina-Montes, Esther; Amiano, Pilar; Huerta Castaño, José M; Gurrea, Aurelio Barricarte; Khaw, Kay-Tee; Lentjes, Marleen A; Key, Timothy J; Romaguera, Dora; Vergnaud, Anne-Claire; Trichopoulou, Antonia; Bamia, Christina; Orfanos, Philippos; Palli, Domenico; Pala, Valeria; Tumino, Rosario; Sacerdote, Carlotta; de Magistris, Maria Santucci; Bueno-de-Mesquita, H Bas; Ocké, Marga C; Beulens, Joline W J; Ericson, Ulrika; Drake, Isabel; Nilsson, Lena M; Winkvist, Anna; Weiderpass, Elisabete; Hjartåker, Anette; Riboli, Elio; Slimani, Nadia

    2014-01-01

    Compared to food patterns, nutrient patterns have been rarely used particularly at international level. We studied, in the context of a multi-center study with heterogeneous data, the methodological challenges regarding pattern analyses. We identified nutrient patterns from food frequency questionnaires (FFQ) in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study and used 24-hour dietary recall (24-HDR) data to validate and describe the nutrient patterns and their related food sources. Associations between lifestyle factors and the nutrient patterns were also examined. Principal component analysis (PCA) was applied on 23 nutrients derived from country-specific FFQ combining data from all EPIC centers (N = 477,312). Harmonized 24-HDRs available for a representative sample of the EPIC populations (N = 34,436) provided accurate mean group estimates of nutrients and foods by quintiles of pattern scores, presented graphically. An overall PCA combining all data captured a good proportion of the variance explained in each EPIC center. Four nutrient patterns were identified explaining 67% of the total variance: Principle component (PC) 1 was characterized by a high contribution of nutrients from plant food sources and a low contribution of nutrients from animal food sources; PC2 by a high contribution of micro-nutrients and proteins; PC3 was characterized by polyunsaturated fatty acids and vitamin D; PC4 was characterized by calcium, proteins, riboflavin, and phosphorus. The nutrients with high loadings on a particular pattern as derived from country-specific FFQ also showed high deviations in their mean EPIC intakes by quintiles of pattern scores when estimated from 24-HDR. Center and energy intake explained most of the variability in pattern scores. The use of 24-HDR enabled internal validation and facilitated the interpretation of the nutrient patterns derived from FFQs in term of food sources. These outcomes open research opportunities and

  11. Nutrient patterns and their food sources in an International Study Setting: report from the EPIC study.

    Directory of Open Access Journals (Sweden)

    Aurelie Moskal

    Full Text Available Compared to food patterns, nutrient patterns have been rarely used particularly at international level. We studied, in the context of a multi-center study with heterogeneous data, the methodological challenges regarding pattern analyses.We identified nutrient patterns from food frequency questionnaires (FFQ in the European Prospective Investigation into Cancer and Nutrition (EPIC Study and used 24-hour dietary recall (24-HDR data to validate and describe the nutrient patterns and their related food sources. Associations between lifestyle factors and the nutrient patterns were also examined. Principal component analysis (PCA was applied on 23 nutrients derived from country-specific FFQ combining data from all EPIC centers (N = 477,312. Harmonized 24-HDRs available for a representative sample of the EPIC populations (N = 34,436 provided accurate mean group estimates of nutrients and foods by quintiles of pattern scores, presented graphically. An overall PCA combining all data captured a good proportion of the variance explained in each EPIC center. Four nutrient patterns were identified explaining 67% of the total variance: Principle component (PC 1 was characterized by a high contribution of nutrients from plant food sources and a low contribution of nutrients from animal food sources; PC2 by a high contribution of micro-nutrients and proteins; PC3 was characterized by polyunsaturated fatty acids and vitamin D; PC4 was characterized by calcium, proteins, riboflavin, and phosphorus. The nutrients with high loadings on a particular pattern as derived from country-specific FFQ also showed high deviations in their mean EPIC intakes by quintiles of pattern scores when estimated from 24-HDR. Center and energy intake explained most of the variability in pattern scores.The use of 24-HDR enabled internal validation and facilitated the interpretation of the nutrient patterns derived from FFQs in term of food sources. These outcomes open research

  12. Primary production, nutrient dynamics and mineralisation in a northeastern Greenland fjord during the summer thaw

    DEFF Research Database (Denmark)

    Rysgaard, S.; Finster, K.; Dahlgaard, H.

    1996-01-01

    This investigation represents the first integrated study of primary production, nutrient dynamics and mineralisation in a northeastern fjord of Greenland. The data presented represent conditions and activities during the early summer thaw (first 2 weeks of July). Primary production (5.3 mmol C m(...

  13. Complete nutrient recovery from source-separated urine by nitrification and distillation.

    Science.gov (United States)

    Udert, K M; Wächter, M

    2012-02-01

    In this study we present a method to recover all nutrients from source-separated urine in a dry solid by combining biological nitrification with distillation. In a first process step, a membrane-aerated biofilm reactor was operated stably for more than 12 months, producing a nutrient solution with a pH between 6.2 and 7.0 (depending on the pH set-point), and an ammonium to nitrate ratio between 0.87 and 1.15 gN gN(-1). The maximum nitrification rate was 1.8 ± 0.3 gN m(-2) d(-1). Process stability was achieved by controlling the pH via the influent. In the second process step, real nitrified urine and synthetic solutions were concentrated in lab-scale distillation reactors. All nutrients were recovered in a dry powder except for some ammonia (less than 3% of total nitrogen). We estimate that the primary energy demand for a simple nitrification/distillation process is four to five times higher than removing nitrogen and phosphorus in a conventional wastewater treatment plant and producing the equivalent amount of phosphorus and nitrogen fertilizers. However, the primary energy demand can be reduced to values very close to conventional treatment, if 80% of the water is removed with reverse osmosis and distillation is operated with vapor compression. The ammonium nitrate content of the solid residue is below the limit at which stringent EU safety regulations for fertilizers come into effect; nevertheless, we propose some additional process steps that will increase the thermal stability of the solid product. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Evaluation of glass leaching as nutrient source for microalgae growth

    International Nuclear Information System (INIS)

    Grabska, N.; Tamayo, A.; Mazo, M. A.; Pascual, L.; Rubio, J.

    2015-01-01

    Three glasses with an elemental composition similar to the nutrient ratio required for Spirulina platensis growth and with different SiO 2 content have been prepared. The glasses were crushed and sieved into 2 different fractions and the effect of the particle size has been studied in terms of the leaching kinetics of each element. The chemical analysis of the leaching water was used for obtaining the dissolution rate curves for each element taking part of the glass composition. From the calculation of the leaching rate constant and the exponential constant of the lixiviation reaction, it has been evaluated the Spirulina platensis growth in ambient normal conditions of light, temperature and pH of the growing media. It has been concluded that, either from the modification of the chemical composition of the glass or its particle size, it is possible to tune the delivery of the nutrients to match the growth rate of Spirulina platensis. (Author)

  15. Human waste: An underestimated source of nutrient pollution in coastal seas of Bangladesh, India and Pakistan.

    Science.gov (United States)

    Amin, Md Nurul; Kroeze, Carolien; Strokal, Maryna

    2017-05-15

    Many people practice open defecation in south Asia. As a result, lot of human waste containing nutrients such as nitrogen (N) and phosphorus (P) enter rivers. Rivers transport these nutrients to coastal waters, resulting in marine pollution. This source of nutrient pollution is, however, ignored in many nutrient models. We quantify nutrient export by large rivers to coastal seas of Bangladesh, India and Pakistan, and the associated eutrophication potential in 2000 and 2050. Our new estimates for N and P inputs from human waste are one to two orders of magnitude higher than earlier model calculations. This leads to higher river export of nutrients to coastal seas, increasing the risk of coastal eutrophication potential (ICEP). The newly calculated future ICEP, for instance, Godavori river is 3 times higher than according to earlier studies. Our modeling approach is simple and transparent and can easily be applied to other data-poor basins. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Primary Sources of Corporate Investment in Hungary

    Directory of Open Access Journals (Sweden)

    Katona Klára

    2017-06-01

    Full Text Available This research aims to reveal how Hungarian companies have financed investments over the last two decades. Which financing strategy characterized them: was internal capital accumulation or external resources, such as bank loans or foreign capital the primary source of corporate investments? The study gives an overview of the conditions typical in the Hungarian financing and capital market over the last 25 years through an empirical analysis. Using a linear regression model, the paper examines the main investments sources among the top 5000 Hungarian firms according to revenues between 1996 and 2014. The model proved that the effect of loans in financing investments was significant and positive in all examined firms, independently from their ownership in the whole period. The rate of indebtedness of foreign companies was mainly attributable to local bank credits and not loans granted by mother companies.

  17. Primary production, nutrients, and size spectra of suspended particles in the southern North Sea

    NARCIS (Netherlands)

    Gieskes, W.W.C.

    1972-01-01

    The effect of nutrient enrichment from the Rhine on some major characteristics of the phytoplankton ecosystem of Dutch coastal waters was studied with 14C, liquid scintillation and Coulter Counter techniques. The magnitude of primary production in the most eutrophic waters closest to

  18. Changes in Nutrients and Primary Production in Barrow Tundra Ponds Over the Past 40 Years

    Science.gov (United States)

    Lougheed, V.; Andresen, C.; Hernandez, C.; Miller, N.; Reyes, F.

    2012-12-01

    The Arctic tundra ponds at the International Biological Program (IBP) site in Barrow, Alaska were studied extensively in the 1970's; however, very little research has occurred there since that time. Due to the sensitivity of this region to climate warming, understanding any changes in the ponds' structure and function over the past 40 years can help identify any potential climate-related impacts. The goal of this study was to determine if the structure and function of primary producers had changed through time, and the association between these changes, urban encroachment and nutrient limitation. Nutrient levels, as well as the biomass of aquatic graminoids (Carex aquatilis and Arctophila fulva), phytoplankton and periphyton were determined in the IBP tundra ponds in both 1971-3 and 2010-12, and in 2010-11 from nearby ponds along an anthropogenic disturbance gradient. Uptake of 14C was also used to measure algal primary production in both time periods and nutrient addition experiments were performed to identify the nutrients limiting algal growth. Similar methods were utilized in the past and present studies. Overall, biomass of graminoids, phytoplankton and periphyton was greater in 2010-12 than that observed in the 1970s. This increased biomass was coincident with warmer water temperatures, increased water column nutrients and deeper active layer depth. Biomass of plants and algae was highest in the ponds closest to the village of Barrow, but no effect of urban encroachment was observed at the IBP ponds. Laboratory incubations indicated that nutrient release from thawing permafrost can explain part of these increases in nutrients and has likely contributed to changes in the primary limiting nutrient. Further studies are necessary to better understand the implications of these trends in primary production to nutrient budgets in the Arctic. The Barrow IBP tundra ponds represent one of the very few locations in the Arctic where long-term data are available on

  19. Geographical Distribution and Sources of Nutrients in Atmospheric Aerosol Over the Pacific Ocean

    Science.gov (United States)

    Uematsu, M.

    2016-12-01

    The Pacific Ocean, the world's largest (occupying about 30% of the Earth's total surface area) has several distinguishing biogeochemical features. In the western Pacific, dust particles originating from arid and semi-arid regions in Asia and Australia are transported to the north and south, respectively. Biomass burning emissions from Southeast Asia are exported to the tropical Pacific, and anthropogenic substances flowing out of Asia and Eurasia spread both regionally and globally. Over high primary productive areas such as the subarctic North Pacific, the equatorial Pacific and the Southern Ocean, biogenic gasses are released to the atmosphere and transported to other areas. These processes may affect cloud and rainfall patterns, air quality, and the radiative balance of downwind regions. The deposition of atmospheric aerosols containing iron and other essential nutrients is important for biogeochemical cycles in the oceans because this source of nutrients helps sustain primary production and affects food-web structure; these effects in turn influence the chemical properties of marine atmosphere. From an atmospheric chemistry standpoint, sea-salt aerosols produced by strong winds and marine biogenic gases emitted from highly productive waters affect the physicochemical characteristics of marine aerosols. As phytoplankton populations are patchy and atmospheric processes sporadic, the interactions between atmospheric chemical constituents and marine biota vary for different regions as well as seasonally and over longer timescales. To address these and other emerging issues, and more generally to better understand the important biogeochemical processes and interactions occurring over the open oceans, more long-term recurrent research cruises with standardized atmospheric shipboard measurements will be needed in the future.

  20. Cost-effective nutrient sources for tissue culture of cassava ( Manihot ...

    African Journals Online (AJOL)

    Application of tissue culture technology is constrained by high costs making seedlings unaffordable. The objective of this study was to evaluate the possibility of using locally available fertilizers as alternative nutrient sources for cassava micropropagation. A Low Cost Medium (LCM) whereby the conventional sources of four ...

  1. Effect of nutrient enrichment on the source and composition of sediment organic carbon in tropical seagrass beds in the South China Sea

    International Nuclear Information System (INIS)

    Liu, Songlin; Jiang, Zhijian; Zhang, Jingping; Wu, Yunchao; Lian, Zhonglian; Huang, Xiaoping

    2016-01-01

    To assess the effect of nutrient enrichment on the source and composition of sediment organic carbon (SOC) beneath Thalassia hemprichii and Enhalus acoroides in tropical seagrass beds, Xincun Bay, South China Sea, intertidal sediment, primary producers, and seawater samples were collected. No significant differences on sediment δ 13 C, SOC, and microbial biomass carbon (MBC) were observed between T. hemprichii and E. acoroides. SOC was mainly of autochthonous origin, while the contribution of seagrass to SOC was less than that of suspended particulate organic matter, macroalgae and epiphytes. High nutrient concentrations contributed substantially to SOC of seagrass, macroalgae, and epiphytes. The SOC, MBC, and MBC/SOC ratio in the nearest transect to fish farming were the highest. This suggested a more labile composition of SOC and shorter turnover times in higher nutrient regions. Therefore, the research indicates that nutrient enrichment could enhance plant-derived contributions to SOC and microbial use efficiency. - Highlights: • Response of sources and composition of SOC to nutrient enrichment was observed. • Similar SOC sources and composition were observed in the two seagrass communities. • Nutrient enrichment enhanced seagrass and macroalgae and epiphytes contribution to SOC. • High nutrient concentration stimulated the MBC and the MBC/SOC ratio.

  2. Connectedness of land use, nutrients, primary production, and fish assemblages in oxbow lakes

    Science.gov (United States)

    Miranda, Leandro E.; Andrews, Caroline S.; Kroger, Robert

    2013-01-01

    We explored the strength of connectedness among hierarchical system components associated with oxbow lakes in the alluvial valley of the Lower Mississippi River. Specifically, we examined the degree of canonical correlation between land use (agriculture and forests), lake morphometry (depth and size), nutrients (total nitrogen and total phosphorus), primary production (chlorophyll-a), and various fish assemblage descriptors. Watershed (p < 0.01) and riparian (p = 0.02) land use, and lake depth (p = 0.05) but not size (p = 0.28), were associated with nutrient concentrations. In turn, nutrients were associated with primary production (p < 0.01), and primary production was associated with sunfish (Centrarchidae) assemblages (p < 0.01) and fish biodiversity (p = 0.08), but not with those of other taxa and functional guilds. Multiple chemical and biological components of oxbow lake ecosystems are connected to landscape characteristics such as land use and lake depth. Therefore, a top-down hierarchical approach can be useful in developing management and conservation plans for oxbow lakes in a region impacted by widespread landscape changes due to agriculture.

  3. Vermicomposting of source-separated human faeces for nutrient recycling.

    Science.gov (United States)

    Yadav, Kunwar D; Tare, Vinod; Ahammed, M Mansoor

    2010-01-01

    The present study examined the suitability of vermicomposting technology for processing source-separated human faeces. Since the earthworm species Eisenia fetida could not survive in fresh faeces, modification in the physical characteristics of faeces was necessary before earthworms could be introduced to faeces. A preliminary study with six different combinations of faeces, soil and bulking material (vermicompost) in different layers was conducted to find out the best condition for biomass growth and reproduction of earthworms. The results indicated that SVFV combination (soil, vermicompost, faeces and vermicompost - bottom to top layers) was the best for earthworm biomass growth indicating the positive role of soil layer in earthworm biomass growth. Further studies with SVFV and VFV combinations, however, showed that soil layer did not enhance vermicompost production rate. Year-long study conducted with VFV combination to assess the quality and quantity of vermicompost produced showed an average vermicompost production rate of 0.30kg-cast/kg-worm/day. The vermicompost produced was mature as indicated by low dissolved organic carbon (2.4+/-0.43mg/g) and low oxygen uptake rate (0.15+/-0.09mg O(2)/g VS/h). Complete inactivation of total coliforms was noted during the study, which is one of the important objectives of human faeces processing. Results of the study thus indicated the potential of vermicomposting for processing of source-separated human faeces.

  4. Cultivation of Nannochloropsis sp. in brackish groundwater supplemented with municipal wastewater as a nutrient source

    Directory of Open Access Journals (Sweden)

    Louise Lins de Sousa

    2014-04-01

    Full Text Available The aim of this work was to study growth potential of the green microalgae Nannochloropsis sp. using brackish groundwater from a well in the semi-arid northeast region of Brazil as culture medium. The medium was supplemented with (% 19.4, 22.0, 44.0 and 50.0% of municipal wastewater after UASB treatment as a low-cost nutrient source. The results showed that the culture tested was capable of growing in the brackish groundwater even at salinity levels as low as 2 ppt. Furthermore it was shown that municipal wastewater could be used as a sole nutrient source for Nannochloropsis sp.

  5. Tracing nutrient sources in the Mississippi River Basin, U.S.A

    International Nuclear Information System (INIS)

    Kendall, C.; Silva, S.R.; Chang, C.C.Y.; Wankel, S.D.; Hooper, R.P.; Frey, J.W.; Crain, A.S.; Delong, M.D.

    2003-01-01

    2000-2001, designed to investigate the usefulness of isotopic techniques for determining nutrient sources in 24 medium and large watersheds in the Basin, found that nitrate and POM from basins with different land uses (e.g., row crops, animal farming, urban development, and undeveloped) had moderately distinctive isotopic compositions. The nitrate δ 18 O and δ 15 N values of the large rivers sites resembled the compositions seen in sites dominated by row crops. Sites with livestock tended to have high δ 15 N values characteristic of manure, and urban and undeveloped sites tended to have higher δ 18 O values characteristic of a significant fraction of atmospheric nitrate. The δ 18 O data were critical in showing abrupt changes in nitrate sources with discharge. Because of the success of the pilot studies, a more thorough study of nutrient sources in the Ohio River Basin was initiated in 2002. For this study, nitrate, POM, and water were collected 15-20 times each year at 6 small NAWQA-program watersheds in the White River-Miami River basins, and at the 7 large river NASQAN-program sites in the Ohio River Basin. Nitrate samples were analyzed for δ 15 N and δ 18 O, POM for δ 15 N and δ 13 C, and water for δ 18 O and δ 2 H. We have also attempted to use the δ 15 N and δ 13 C of fish as indicators of nutrient sources. Other studies have also indicated that POM consists primarily of phytoplankton. Additionally, these studies indicated that POM transported in the water column, particularly size fractions < 1-mm diameter, were the primary food source for food webs in the Ohio and Upper Mississippi Rivers. The sites being sampled are part of ongoing USGS studies to investigate a) transport and fate of agricultural contaminants and b) nutrient enrichment effects on aquatic biota in the Ohio River Basin. Questions we hope to answer in this pilot study are: (1) Are there event-related shifts in isotopic values and hence nitrate and POM sources? (2) Are there

  6. Modelling nutrient fluxes from source to river load : a macroscopic analysis applied to the Rhine and Elbe basins

    NARCIS (Netherlands)

    Wit, de M.

    2000-01-01

    In many European rivers, including the major streams of the Rhine and Elbe basins, the nutrient load (N and P) still exceeds target levels. In this paper, a model is presented that describes the river nutrient load as a function of nutrient sources, runoff and lithology in the upstream basin. The

  7. Directional and Spectral Irradiance in Ocean Models: Effects on Simulated Global Phytoplankton, Nutrients, and Primary Production

    Science.gov (United States)

    Gregg, Watson W.; Rousseaux, Cecile S.

    2016-01-01

    The importance of including directional and spectral light in simulations of ocean radiative transfer was investigated using a coupled biogeochemical-circulation-radiative model of the global oceans. The effort focused on phytoplankton abundances, nutrient concentrations and vertically-integrated net primary production. The importance was approached by sequentially removing directional (i.e., direct vs. diffuse) and spectral irradiance and comparing results of the above variables to a fully directionally and spectrally-resolved model. In each case the total irradiance was kept constant; it was only the pathways and spectral nature that were changed. Assuming all irradiance was diffuse had negligible effect on global ocean primary production. Global nitrate and total chlorophyll concentrations declined by about 20% each. The largest changes occurred in the tropics and sub-tropics rather than the high latitudes, where most of the irradiance is already diffuse. Disregarding spectral irradiance had effects that depended upon the choice of attenuation wavelength. The wavelength closest to the spectrally-resolved model, 500 nm, produced lower nitrate (19%) and chlorophyll (8%) and higher primary production (2%) than the spectral model. Phytoplankton relative abundances were very sensitive to the choice of non-spectral wavelength transmittance. The combined effects of neglecting both directional and spectral irradiance exacerbated the differences, despite using attenuation at 500 nm. Global nitrate decreased 33% and chlorophyll decreased 24%. Changes in phytoplankton community structure were considerable, representing a change from chlorophytes to cyanobacteria and coccolithophores. This suggested a shift in community function, from light-limitation to nutrient limitation: lower demands for nutrients from cyanobacteria and coccolithophores favored them over the more nutrient-demanding chlorophytes. Although diatoms have the highest nutrient demands in the model, their

  8. Mechanical sludge disintegration for the production of carbon source for biological nutrient removal.

    Science.gov (United States)

    Kampas, P; Parsons, S A; Pearce, P; Ledoux, S; Vale, P; Churchley, J; Cartmell, E

    2007-04-01

    The primary driver for a successful biological nutrient removal is the availability of suitable carbon source, mainly in the form of volatile fatty acids (VFA). Several methods have been examined to increase the amount of VFAs in wastewater. This study investigates the mechanism of mechanical disintegration of thickened surplus activated sludge by a deflaker technology for the production of organic matter. This equipment was able to increase the soluble carbon in terms of VFA and soluble chemical oxygen demand (SCOD) with the maximum concentration to be around 850 and 6530 mgl(-1), for VFA and SCOD, respectively. The particle size was reduced from 65.5 to 9.3 microm after 15 min of disintegration with the simultaneous release of proteins (1550 mgl(-1)) and carbohydrates (307 mgl(-1)) indicating floc disruption and breakage. High performance size exclusion chromatography investigated the disintegrated sludge and confirmed that the deflaker was able to destroy the flocs releasing polymeric substances that are typically found outside of cells. When long disintegration times were applied (>or=10 min or >or=9000 kJkg(-1)TS of specific energy) smaller molecular size materials were released to the liquid phase, which are considered to be found inside the cells indicating cell lysis.

  9. Magnesium-aerial primary current source

    Directory of Open Access Journals (Sweden)

    Barba I. N.

    2007-12-01

    Full Text Available Novel metal-air chemical power sources (CPS 3,0-ВМБ-7,5 have been developed. They have an unlimited shelf life and, even after decades of storage, give almost 100% of the designed capacity. These sources are water-activated. An aqueous salt solution is used as an electrolyte. Such sources are designed for single continuous or discontinuous discharge. The paper presents electrochemical reactions at the electrodes during CPS discharge. Comparison of electrical characteristics of the developed power source and various types of "dry cells" has shown that the developed sources have higher energy characteristics.

  10. Influence of Sources and Rates of Manure on Yield and Nutrient ...

    African Journals Online (AJOL)

    of University of Maiduguri to assess the effects of sources and rates of manure ... Cow manure treatment on average, produced the best of growth, yield and nutrient uptake (N,P, and K ... fertilizers coupled with their inability to condition the soil.

  11. External Carbon Source Addition as a Means to Control an Activated Sludge Nutrient Removal Process

    DEFF Research Database (Denmark)

    Isaacs, Steven Howard; Henze, Mogens; Søeberg, Henrik

    1994-01-01

    In alternating type activated sludge nutrient removal processes, the denitrification rate can be limited by the availability of readily-degradable carbon substrate. A control strategy is proposed by which an easily metabolizable COD source is added directly to that point in the process at which d...

  12. Fructose-asparagine is a primary nutrient during growth of Salmonella in the inflamed intestine.

    Directory of Open Access Journals (Sweden)

    Mohamed M Ali

    2014-06-01

    Full Text Available Salmonella enterica serovar Typhimurium (Salmonella is one of the most significant food-borne pathogens affecting both humans and agriculture. We have determined that Salmonella encodes an uptake and utilization pathway specific for a novel nutrient, fructose-asparagine (F-Asn, which is essential for Salmonella fitness in the inflamed intestine (modeled using germ-free, streptomycin-treated, ex-germ-free with human microbiota, and IL10-/- mice. The locus encoding F-Asn utilization, fra, provides an advantage only if Salmonella can initiate inflammation and use tetrathionate as a terminal electron acceptor for anaerobic respiration (the fra phenotype is lost in Salmonella SPI1- SPI2- or ttrA mutants, respectively. The severe fitness defect of a Salmonella fra mutant suggests that F-Asn is the primary nutrient utilized by Salmonella in the inflamed intestine and that this system provides a valuable target for novel therapies.

  13. Managed nutrient reduction impacts on nutrient concentrations, water clarity, primary production, and hypoxia in a north temperate estuary

    Science.gov (United States)

    Oviatt, Candace; Smith, Leslie; Krumholz, Jason; Coupland, Catherine; Stoffel, Heather; Keller, Aimee; McManus, M. Conor; Reed, Laura

    2017-12-01

    Except for the Providence River and side embayments like Greenwich Bay, Narragansett Bay can no longer be considered eutrophic. In summer 2012 managed nitrogen treatment in Narragansett Bay achieved a goal of reducing effluent dissolved inorganic nitrogen inputs by over 50%. Narragansett Bay represents a small northeast US estuary that had been heavily loaded with sewage effluent nutrients since the late 1800s. The input reduction was reflected in standing stock nutrients resulting in a statistically significant 60% reduction in concentration. In the Providence River estuary, total nitrogen decreased from 100 μm to about 40 μm, for example. We tested four environmental changes that might be associated with the nitrogen reduction. System apparent production was significantly decreased by 31% and 45% in the upper and mid Bay. Nutrient reductions resulted in statistically improved water clarity in the mid and upper Bay and in a 34% reduction in summer hypoxia. Nitrogen reduction also reduced the winter spring diatom bloom; winter chlorophyll levels after nutrient reduction have been significantly lower than before the reduction. The impact on the Bay will continue to evolve over the next few years and be a natural experiment for other temperate estuaries that will be experiencing nitrogen reduction. To provide perspective we review factors effecting hypoxia in other estuaries with managed nutrient reduction and conclude that, as in Narragansett Bay, physical factors can be as important as nutrients. On a positive note managed nutrient reduction has mitigated further deterioration in most estuaries.

  14. Treatment of Source-Separated Blackwater: A Decentralized Strategy for Nutrient Recovery towards a Circular Economy

    Directory of Open Access Journals (Sweden)

    Melesse Eshetu Moges

    2018-04-01

    Full Text Available Using a filter medium for organic matter removal and nutrient recovery from blackwater treatment is a novel concept and has not been investigated sufficiently to date. This paper demonstrates a combined blackwater treatment and nutrient-recovery strategy and establishes mechanisms for a more dependable source of plant nutrients aiming at a circular economy. Source-separated blackwater from a student dormitory was used as feedstock for a sludge blanket anaerobic-baffled reactor. The effluent from the reactor, with 710 mg L−1 NH4–N and 63 mg L−1 PO4–P, was treated in a sequence of upflow and downflow filtration columns using granular activated carbon, Cocos char and polonite as filter media at a flow rate of 600 L m−2 day−1 and organic loading rate of 430 g chemical oxygen demand (COD m−2 day−1. Filtration treatment of the anaerobic effluent with carbon adsorbents removed 80% of the residual organic matter, more than 90% of suspended solids, and turbidity while releasing more than 76% NH4–N and 85% of PO4–P in the liquid phase. The treatment train also removed total coliform bacteria and E. coli in the effluent, achieving concentrations below detection limit after the integration of ultraviolet (UV light. These integrated technological pathways ensure simultaneous nutrient recovery as a nutrient solution, pathogen inactivation, and reduction of active organic substances. The treated nutrient-rich water can be applied as a source of value creation for various end-use options.

  15. CADDIS Volume 2. Sources, Stressors and Responses: Nutrients - Simple Conceptual Diagram

    Science.gov (United States)

    Introduction to the nutrients module, when to list nutrients as a candidate cause, ways to measure nutrients, simple and detailed conceptual diagrams for nutrients, nutrients module references and literature reviews.

  16. CADDIS Volume 2. Sources, Stressors and Responses: Nutrients - Detailed Conceptual Diagram (P)

    Science.gov (United States)

    Introduction to the nutrients module, when to list nutrients as a candidate cause, ways to measure nutrients, simple and detailed conceptual diagrams for nutrients, nutrients module references and literature reviews.

  17. CADDIS Volume 2. Sources, Stressors and Responses: Nutrients - Detailed Conceptual Diagram (N)

    Science.gov (United States)

    Introduction to the nutrients module, when to list nutrients as a candidate cause, ways to measure nutrients, simple and detailed conceptual diagrams for nutrients, nutrients module references and literature reviews.

  18. Effect of nutrient enrichment on the source and composition of sediment organic carbon in tropical seagrass beds in the South China Sea.

    Science.gov (United States)

    Liu, Songlin; Jiang, Zhijian; Zhang, Jingping; Wu, Yunchao; Lian, Zhonglian; Huang, Xiaoping

    2016-09-15

    To assess the effect of nutrient enrichment on the source and composition of sediment organic carbon (SOC) beneath Thalassia hemprichii and Enhalus acoroides in tropical seagrass beds, Xincun Bay, South China Sea, intertidal sediment, primary producers, and seawater samples were collected. No significant differences on sediment δ(13)C, SOC, and microbial biomass carbon (MBC) were observed between T. hemprichii and E. acoroides. SOC was mainly of autochthonous origin, while the contribution of seagrass to SOC was less than that of suspended particulate organic matter, macroalgae and epiphytes. High nutrient concentrations contributed substantially to SOC of seagrass, macroalgae, and epiphytes. The SOC, MBC, and MBC/SOC ratio in the nearest transect to fish farming were the highest. This suggested a more labile composition of SOC and shorter turnover times in higher nutrient regions. Therefore, the research indicates that nutrient enrichment could enhance plant-derived contributions to SOC and microbial use efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Ethnic disparities among food sources of energy and nutrients of public health concern and nutrients to limit in adults in the United States: NHANES 2003-2006.

    Science.gov (United States)

    O'Neil, Carol E; Nicklas, Theresa A; Keast, Debra R; Fulgoni, Victor L

    2014-01-01

    Identification of current food sources of energy and nutrients among US non-Hispanic whites (NHW), non-Hispanic blacks (NHB), and Mexican American (MA) adults is needed to help with public health efforts in implementing culturally sensitive and feasible dietary recommendations. The objective of this study was to determine the food sources of energy and nutrients to limit [saturated fatty acids (SFA), added sugars, and sodium] and nutrients of public health concern (dietary fiber, vitamin D, calcium, and potassium) by NHW, NHB, and MA adults. This was a cross-sectional analysis of a nationally representative sample of NWH (n=4,811), NHB (2,062), and MA (n=1,950) adults 19+ years. The 2003-2006 NHANES 24-h recall (Day 1) dietary intake data were analyzed. An updated USDA Dietary Source Nutrient Database was developed using current food composition databases. Food grouping included ingredients from disaggregated mixtures. Mean energy and nutrient intakes from food sources were sample-weighted. Percentages of total dietary intake contributed from food sources were ranked. Multiple differences in intake among ethnic groups were seen for energy and all nutrients examined. For example, energy intake was higher in MA as compared to NHB; SFA, added sugars, and sodium intakes were higher in NHW than NHB; dietary fiber was highest in MA and lowest in NHB; vitamin D was highest in NHW; calcium was lowest in NHB; and potassium was higher in NHW as compared to NHB. Food sources of these nutrients also varied. Identification of intake of nutrients to limit and of public health concern can help health professionals implement appropriate dietary recommendations and plan interventions that are ethnically appropriate.

  20. Modeling nutrient sources, transport and management strategies in a coastal watershed, Southeast China.

    Science.gov (United States)

    Zhou, Pei; Huang, Jinliang; Hong, Huasheng

    2018-01-01

    Integrated watershed management requires an analytical model capable of revealing the full range of impacts that would be caused by the uses and developments in the watershed. The SPAtially Referenced Regressions On Watershed Attributes (SPARROW) model was developed in this study to provide empirical estimates of the sources, transport of total nitrogen (TN) and total phosphorus (TP) and to develop nutrient management strategies in the Jiulong River Watershed, southeast China that has enormous influence on the region's ecological safety. We calibrated the model using data related to daily streamflow, monthly TN and TP concentrations in 2014 at 30 locations. The model produced R 2 values for TN with 0.95 and TP with 0.94. It was found that for the entire watershed, TN came from fertilizer application (43%), livestock breeding (39%) and sewage discharge (18%), while TP came from livestock breeding (46%), fertilizer application (46%), and industrial discharge (8%). Fifty-eight percent of the TN and 80% of the TP in upstream reaches are delivered to the outlets of North and West rivers. A scenario analysis with SPARROW was coupled to develop suitable management strategies. Results revealed that controlling nutrient sources was effective in improving water quality. Normally sharp reduction in nutrient sources is not operational feasible. Hence, it is recommended that preventing nutrient on land from entering into the river as a suitable strategy in watershed management. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Nutrient transitions are a source of persisters in Escherichia coli biofilms.

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    Stephanie M Amato

    Full Text Available Chronic and recurrent infections have been attributed to persisters in biofilms, and despite this importance, the mechanisms of persister formation in biofilms remain unclear. The plethora of biofilm characteristics that could give rise to persisters, including slower growth, quorum signaling, oxidative stress, and nutrient heterogeneity, have complicated efforts to delineate formation pathways that generate persisters during biofilm development. Here we sought to specifically determine whether nutrient transitions, which are a common metabolic stress encountered within surface-attached communities, stimulate persister formation in biofilms and if so, to then identify the pathway. To accomplish this, we established an experimental methodology where nutrient availability to biofilm cells could be controlled exogenously, and then used that method to discover that diauxic carbon source transitions stimulated persister formation in Escherichia coli biofilms. Previously, we found that carbon source transitions stimulate persister formation in planktonic E. coli cultures, through a pathway that involved ppGpp and nucleoid-associated proteins, and therefore, tested the functionality of that pathway in biofilms. Biofilm persister formation was also found to be dependent on ppGpp and nucleoid-associated proteins, but the importance of specific proteins and enzymes between biofilm and planktonic lifestyles was significantly different. Data presented here support the increasingly appreciated role of ppGpp as a central mediator of bacterial persistence and demonstrate that nutrient transitions can be a source of persisters in biofilms.

  2. Nutrient transitions are a source of persisters in Escherichia coli biofilms.

    Science.gov (United States)

    Amato, Stephanie M; Brynildsen, Mark P

    2014-01-01

    Chronic and recurrent infections have been attributed to persisters in biofilms, and despite this importance, the mechanisms of persister formation in biofilms remain unclear. The plethora of biofilm characteristics that could give rise to persisters, including slower growth, quorum signaling, oxidative stress, and nutrient heterogeneity, have complicated efforts to delineate formation pathways that generate persisters during biofilm development. Here we sought to specifically determine whether nutrient transitions, which are a common metabolic stress encountered within surface-attached communities, stimulate persister formation in biofilms and if so, to then identify the pathway. To accomplish this, we established an experimental methodology where nutrient availability to biofilm cells could be controlled exogenously, and then used that method to discover that diauxic carbon source transitions stimulated persister formation in Escherichia coli biofilms. Previously, we found that carbon source transitions stimulate persister formation in planktonic E. coli cultures, through a pathway that involved ppGpp and nucleoid-associated proteins, and therefore, tested the functionality of that pathway in biofilms. Biofilm persister formation was also found to be dependent on ppGpp and nucleoid-associated proteins, but the importance of specific proteins and enzymes between biofilm and planktonic lifestyles was significantly different. Data presented here support the increasingly appreciated role of ppGpp as a central mediator of bacterial persistence and demonstrate that nutrient transitions can be a source of persisters in biofilms.

  3. Turning the table: plants consume microbes as a source of nutrients.

    Directory of Open Access Journals (Sweden)

    Chanyarat Paungfoo-Lonhienne

    Full Text Available Interactions between plants and microbes in soil, the final frontier of ecology, determine the availability of nutrients to plants and thereby primary production of terrestrial ecosystems. Nutrient cycling in soils is considered a battle between autotrophs and heterotrophs in which the latter usually outcompete the former, although recent studies have questioned the unconditional reign of microbes on nutrient cycles and the plants' dependence on microbes for breakdown of organic matter. Here we present evidence indicative of a more active role of plants in nutrient cycling than currently considered. Using fluorescent-labeled non-pathogenic and non-symbiotic strains of a bacterium and a fungus (Escherichia coli and Saccharomyces cerevisiae, respectively, we demonstrate that microbes enter root cells and are subsequently digested to release nitrogen that is used in shoots. Extensive modifications of root cell walls, as substantiated by cell wall outgrowth and induction of genes encoding cell wall synthesizing, loosening and degrading enzymes, may facilitate the uptake of microbes into root cells. Our study provides further evidence that the autotrophy of plants has a heterotrophic constituent which could explain the presence of root-inhabiting microbes of unknown ecological function. Our discovery has implications for soil ecology and applications including future sustainable agriculture with efficient nutrient cycles.

  4. Dietary intake of energy-dense, nutrient-poor and nutrient-dense food sources in children with cystic fibrosis.

    Science.gov (United States)

    Sutherland, Rosie; Katz, Tamarah; Liu, Victoria; Quintano, Justine; Brunner, Rebecca; Tong, Chai Wei; Collins, Clare E; Ooi, Chee Y

    2018-04-30

    Prescription of a high-energy, high-fat diet is a mainstay of nutrition management in cystic fibrosis (CF). However, families may be relying on energy-dense, nutrient-poor (EDNP) foods rather than nutrient-dense (ND) foods to meet dietary targets. We aimed to evaluate the relative contribution of EDNP and ND foods to the usual diets of children with CF and identify sociodemographic factors associated with higher EDNP intakes. This is a cross-sectional comparison of children with CF aged 2-18 years and age- and gender-matched controls. Dietary intake was assessed using the Australian Child and Adolescent Eating Survey (ACAES) food frequency questionnaire. Children with CF (n = 80: 37 males; mean age 9.3 years) consumed significantly more EDNP foods than controls (mean age 9.8 years) in terms of both total energy (median [IQR]: 1301 kcal/day (843-1860) vs. 686 kcal/day (480-1032); p energy intake (median [IQR]: 44% (34-51) vs. 31% (24-43); p energy requirements (median [IQR]: 158% (124-187) vs. 112% (90-137); p energy- and fat-dense CF diet is primarily achieved by overconsumption of EDNP foods, rather than ND sources. This dietary pattern may not be optimal for the future health of children with CF, who are now expected to survive well into adulthood. Copyright © 2018 European Cystic Fibrosis Society. All rights reserved.

  5. Using Stable Isotopes to Link Nutrient Sources in the Everglades and Biological Sinks in Florida Bay: A Biogeochemical Approach to Evaluate Ecosystem Response to Changing Nutrient Regimes

    Science.gov (United States)

    Hoare, A. M.; Hollander, D. J.; Heil, C.; Glibert, P.; Murasko, S.; Revilla, M.; Alexander, J.

    2005-05-01

    Anthropogenic influences in South Florida have led to deterioration of its two major ecosystems, the Everglades wetlands and the Florida Bay estuary. Consequently, the Comprehensive Everglades Restoration Plan has been proposed to restore the Everglades ecosystem; however, restoration efforts will likely exert new ecological changes in the Everglades and ultimately Florida Bay. The success of the Florida Everglades restoration depends on our understanding and ability to predict how regional changes in the distribution and composition of dissolved organic and inorganic nutrients will direct the downstream biogeochemical dynamics of Florida Bay. While the transport of freshwater and nutrients to Florida Bay have been studied, much work remains to directly link nutrient dynamics in Florida Bay to nutrient sources in the Everglades. Our study uses stable C and N isotopic measurements of chemical and biological materials from the Everglades and Florida Bay as part of a multi-proxy approach to link nutrient sources in the Everglades to biological sinks in Florida Bay. Isotopic analyses of dissolved and particulate species of water, aquatic vegetation and sedimentary organic matter show that the watersheds within the Everglades are chemically distinct and that these signatures are also reflected in the bay. A large east-west gradient in both carbon and nitrogen (as much as 10‰ for δ15N POM) reflect differing nutrient sources for each region of Florida Bay and is strongly correlated with upstream sources in the Everglades. Isotopic signatures also reflect seasonal relationships associated with wet and dry periods. High C and N measurements of DOM and POM measurements suggest significant influence from waste water in Canal C-111 in eastern Florida Bay, particularly during the dry season. These observations show that nutrients from the Everglades watersheds enter Florida Bay and are important in controlling biogeochemical processes in the bay. This study proves that

  6. Comparison between disintegrated and fermented sewage sludge for production of a carbon source suitable for biological nutrient removal.

    Science.gov (United States)

    Soares, Ana; Kampas, Pantelis; Maillard, Sarah; Wood, Elizabeth; Brigg, Jon; Tillotson, Martin; Parsons, Simon A; Cartmell, Elise

    2010-03-15

    There is a need to investigate processes that enable sludge re-use while enhancing sewage treatment efficiency. Mechanically disintegrated thickened surplus activated sludge (SAS) and fermented primary sludge were compared for their capacity to produce a carbon source suitable for BNR by completing nutrient removal predictive tests. Mechanically disintegration of SAS using a deflaker enhanced volatile fatty acids (VFAs) content from 92 to 374 mg l(-1) (4.1-fold increase). In comparison, primary sludge fermentation increased the VFAs content from 3.5 g l(-1) to a final concentration of 8.7 g l(-1) (2.5-fold increase). The carbon source obtained from disintegration and fermentation treatments improved phosphate (PO(4)-P) release and denitrification by up to 0.04 mg NO(3)-Ng(-1)VSS min(-1) and 0.031 mg PO(4)-Pg(-1)VSS min(-1), respectively, in comparison to acetate (0.023 mg NO(3)-Ng(-1)VSS min(-1)and 0.010 mg PO(4)-Pg(-1)VSS min(-1)). Overall, both types of sludge were suitable for BNR but disintegrated SAS displayed lower carbon to nutrient ratios of 8 for SCOD:PO(4)-P and 9 for SCOD:NO(3)-N. On the other hand, SAS increased the concentration of PO(4)-P in the settled sewage by a further 0.97 g PO(4)-P kg(-1)SCOD indicating its potential negative impact towards nutrient recycling in the BNR process. (c) 2009 Elsevier B.V. All rights reserved.

  7. Teaching Discrete Mathematics Entirely from Primary Historical Sources

    Science.gov (United States)

    Barnett, Janet Heine; Bezhanishvili, Guram; Lodder, Jerry; Pengelley, David

    2016-01-01

    We describe teaching an introductory discrete mathematics course entirely from student projects based on primary historical sources. We present case studies of four projects that cover the content of a one-semester course, and mention various other courses that we have taught with primary source projects.

  8. Teaching and Learning Mathematics from Primary Historical Sources

    Science.gov (United States)

    Barnett, Janet Heine; Lodder, Jerry; Pengelley, David

    2016-01-01

    Why would anyone think of teaching and learning mathematics directly from primary historical sources? We aim to answer this question while sharing our own experiences, and those of our students across several decades. We will first describe the evolution of our motivation for teaching with primary sources, and our current view of the advantages…

  9. Combined use of stable isotopes and hydrologic modeling to better understand nutrient sources and cycling in highly altered systems (Invited)

    Science.gov (United States)

    Young, M. B.; Kendall, C.; Guerin, M.; Stringfellow, W. T.; Silva, S. R.; Harter, T.; Parker, A.

    2013-12-01

    The Sacramento and San Joaquin Rivers provide the majority of freshwater for the San Francisco Bay Delta. Both rivers are important sources of drinking and irrigation water for California, and play critical roles in the health of California fisheries. Understanding the factors controlling water quality and primary productivity in these rivers and the Delta is essential for making sound economic and environmental water management decisions. However, these highly altered surface water systems present many challenges for water quality monitoring studies due to factors such as multiple potential nutrient and contaminant inputs, dynamic source water inputs, and changing flow regimes controlled by both natural and engineered conditions. The watersheds for both rivers contain areas of intensive agriculture along with many other land uses, and the Sacramento River receives significant amounts of treated wastewater from the large population around the City of Sacramento. We have used a multi-isotope approach combined with mass balance and hydrodynamic modeling in order to better understand the dominant nutrient sources for each of these rivers, and to track nutrient sources and cycling within the complex Delta region around the confluence of the rivers. High nitrate concentrations within the San Joaquin River fuel summer algal blooms, contributing to low dissolved oxygen conditions. High δ15N-NO3 values combined with the high nitrate concentrations suggest that animal manure is a significant source of nitrate to the San Joaquin River. In contrast, the Sacramento River has lower nitrate concentrations but elevated ammonium concentrations from wastewater discharge. Downstream nitrification of the ammonium can be clearly traced using δ15N-NH4. Flow conditions for these rivers and the Delta have strong seasonal and inter-annual variations, resulting in significant changes in nutrient delivery and cycling. Isotopic measurements and estimates of source water contributions

  10. Can We Manage Nonpoint-Source Pollution Using Nutrient Concentrations during Seasonal Baseflow?

    Directory of Open Access Journals (Sweden)

    James A. McCarty

    2016-05-01

    Full Text Available Nationwide, a substantial amount of resources has been targeted toward improving water quality, particularly focused on nonpoint-source pollution. This study was conducted to evaluate the relationship between nutrient concentrations observed during baseflow and runoff conditions from 56 sites across five watersheds in Arkansas. Baseflow and stormflow concentrations for each site were summarized using geometric mean and then evaluated for directional association. A significant, positive correlation was found for NO–N, total N, soluble reactive P, and total P, indicating that sites with high baseflow concentrations also had elevated runoff concentrations. Those landscape factors that influence nutrient concentrations in streams also likely result in increased runoff, suggesting that high baseflow concentrations may reflect elevated loads from the watershed. The results highlight that it may be possible to collect water-quality data during baseflow to help define where to target nonpoint-source pollution best management practices within a watershed.

  11. Modeling Nutrient Release in the Tai Lake Basin of China: Source Identification and Policy Implications

    Science.gov (United States)

    Liu, Beibei; Liu, Heng; Zhang, Bing; Bi, Jun

    2013-03-01

    Because nutrient enrichment has become increasingly severe in the Tai Lake Basin of China, identifying sources and loads is crucial for watershed nutrient management. This paper develops an empirical framework to estimate nutrient release from five major sectors, which requires fewer input parameters and produces acceptable accuracy. Sectors included are industrial manufacturing, livestock breeding (industrial and family scale), crop agriculture, household consumption (urban and rural), and atmospheric deposition. Results show that in the basin (only the five sectors above), total nutrient loads of nitrogen (N) and phosphorus (P) into aquatic systems in 2008 were 33043.2 tons N a-1 and 5254.4 tons P a-1, and annual area-specific nutrient loads were 1.94 tons N km-2 and 0.31 tons P km-2. Household consumption was the major sector having the greatest impact (46 % in N load, 47 % in P load), whereas atmospheric deposition (18 %) and crop agriculture (15 %) sectors represented other significant proportions of N load. The load estimates also indicate that 32 % of total P came from the livestock breeding sector, making it the second largest phosphorus contributor. According to the nutrient pollution sectors, six best management practices are selected for cost-effectiveness analysis, and feasible options are recommended. Overall, biogas digester construction on industrial-scale farms is proven the most cost-effective, whereas the building of rural decentralized facilities is the best alternative under extreme financial constraint. However, the reduction potential, average monetary cost, and other factors such as risk tolerance of policy makers should all be considered in the actual decision-making process.

  12. Nutrient dynamics and primary production in a pristine coastal mangrove ecosystem: Andaman Islands, India

    Science.gov (United States)

    Jenkins, E. N.; Nickodem, K.; Siemann, A. L.; Hoeher, A.; Sundareshwar, P. V.; Ramesh, R.; Purvaja, R.; Banerjee, K.; Manickam, S.; Haran, H.

    2012-12-01

    Mangrove ecosystems play a key role in supporting coastal food webs and nutrient cycles in the coastal zone. Their strategic position between the land and the sea make them important sites for land-ocean interaction. As part of an Indo-US summer field course we investigated changes in the water chemistry in a pristine mangrove creek located at Wright Myo in the Andaman Islands, India. This study was conducted during the wet season (June 2012) to evaluate the influence of the coastal mangrove wetlands on the water quality and productivity in adjoining pelagic waters. Over a full tidal cycle spanning approximately 24 hrs, we measured nutrient concentrations and other ancillary parameters (e.g. dissolved oxygen, turbidity, salinity, etc.) hourly to evaluate water quality changes in incoming and ebbing tides. Nutrient analyses had the following concentration ranges (μM): nitrite 0.2-0.9, nitrate 2.0-11.5, ammonium 1.3-7.5, dissolved inorganic phosphate 0.7-2.8. The dissolved inorganic nitrogen to dissolved inorganic phosphate (DIN/DIP) ratio was very low relative to an optimal ratio, suggesting growth is nitrogen limited. In addition, we conducted primary production assays to investigate the factors that controlled primary production in this pristine creek. The experiment was carried out in situ using the Winkler method at low and high tide. Four-hour incubation of light and dark bottles representing a fixed control, non-fertilized, fertilized with nitrate, and fertilized with phosphate enabled the measurement of both net oxygen production and dark respiration. The low tide experiment suggests the ecosystem is heterotrophic because the oxygen measured in the light bottles was consistently less than that of the dark bottles. This result may be an experimental artifact of placing the glass bottles in the sun for too long prior to incubation, potentially leading to photolysis of large organic molecules in the light bottles. The high tide experiment also displayed

  13. Multiple metabolic alterations exist in mutant PI3K cancers, but only glucose is essential as a nutrient source.

    Directory of Open Access Journals (Sweden)

    Rebecca Foster

    Full Text Available Targeting tumour metabolism is becoming a major new area of pharmaceutical endeavour. Consequently, a systematic search to define whether there are specific energy source dependencies in tumours, and how these might be dictated by upstream driving genetic mutations, is required. The PI3K-AKT-mTOR signalling pathway has a seminal role in regulating diverse cellular processes including cell proliferation and survival, but has also been associated with metabolic dysregulation. In this study, we sought to define how mutations within PI3KCA may affect the metabolic dependency of a cancer cell, using precisely engineered isogenic cell lines. Studies revealed gene expression signatures in PIK3CA mutant cells indicative of a consistent up-regulation of glycolysis. Interestingly, the genes up- and down-regulated varied between isogenic models suggesting that the primary node of regulation is not the same between models. Additional gene expression changes were also observed, suggesting that metabolic pathways other than glycolysis, such as glutaminolysis, were also affected. Nutrient dependency studies revealed that growth of PIK3CA mutant cells is highly dependent on glucose, whereas glutamine dependency is independent of PIK3CA status. In addition, the glucose dependency exhibited by PIK3CA mutant cells could not be overridden by supplementation with other nutrients. This specific dependence on glucose for growth was further illustrated by studies evaluating the effects of targeted disruption of the glycolytic pathway using siRNA and was also found to be present across a wider panel of cancer cell lines harbouring endogenous PIK3CA mutations. In conclusion, we have found that PIK3CA mutations lead to a shift towards a highly glycolytic phenotype, and that despite suggestions that cancer cells are adept at utilising alternative nutrient sources, PIK3CA mutant cells are not able to compensate for glucose withdrawal. Understanding the metabolic

  14. Effects of Maize Source and Complex Enzymes on Performance and Nutrient Utilization of Broilers

    Directory of Open Access Journals (Sweden)

    Defu Tang

    2014-12-01

    Full Text Available The objective of this study was to investigate the effect of maize source and complex enzymes containing amylase, xylanase and protease on performance and nutrient utilization of broilers. The experiment was a 4×3 factorial design with diets containing four source maize samples (M1, M2, M3, and M4 and without or with two kinds of complex enzyme A (Axtra XAP and B (Avizyme 1502. Nine hundred and sixty day old Arbor Acres broiler chicks were used in the trial (12 treatments with 8 replicate pens of 10 chicks. Birds fed M1 diet had better body weight gain (BWG and lower feed/gain ratio compared with those fed M3 diet and M4 diet (p0.05, respectively. The fresh feces output was significantly decreased by the addition of enzyme B (p<0.05. Maize source affects the nutrients digestibility and performance of broilers, and a combination of amylase, xylanase and protease is effective in improving the growth profiles of broilers fed maize-soybean-rapeseed-cotton mixed diets.

  15. Utilization of solid catfish manure waste as carbon and nutrient source for lactic acid production.

    Science.gov (United States)

    Shi, Suan; Li, Jing; Blersch, David M

    2018-04-19

    The aim of this work was to study the solid waste (manure) produced by catfish as a potential feedstock for the production of lactic acid (LA) via fermentation. The solid waste contains high levels of both carbohydrates and nutrients that are sufficient for LA bacteria. Simultaneous saccharification and co-fermentation (SSCF) was applied using enzyme and Lactobacillus pentosus, and different loadings of enzyme and solid waste were tested. Results showed LA concentrations of 35.7 g/L were obtained at 15% solids content of catfish waste. Because of the high nutrient content in the fish waste, it could also be used as supplementary substrate for nitrogen and carbon sources with other lignocellulosic materials. A combined feedstock of catfish waste and paper mill sludge was tested, increasing the final LA concentration to 43.1 g/L at 12% solids loading. The catfish waste was shown to be a potential feedstock to provide both carbon and nutrients for LA production, suggesting its use as a sole substrate or in combination with other lignocellulosic materials.

  16. Food sources of energy and nutrients in Finnish girls and boys 6-8 years of age - the PANIC study.

    Science.gov (United States)

    Eloranta, Aino-Maija; Venäläinen, Taisa; Soininen, Sonja; Jalkanen, Henna; Kiiskinen, Sanna; Schwab, Ursula; Lakka, Timo A; Lindi, Virpi

    2016-01-01

    Data on food sources of nutrients are needed to improve strategies to enhance nutrient intake among girls and boys in Western countries. To identify major food sources of energy, energy nutrients, dietary fibre, and micronutrients, and to study gender differences in these food sources among children. We assessed food consumption and nutrient intake using 4-day food records in a population sample of Finnish girls ( n =213) and boys ( n =217) aged 6-8 years from the Physical Activity and Nutrition in Children Study. We calculated the percentual contribution of 55 food groups for energy and nutrient intake using the population proportion method. Low-fibre grain products, skimmed milk, and high-fibre bread provided almost 23% of total energy intake. Skimmed milk was the top source of protein (18% of total intake), vitamin D (32%), potassium (20%), calcium (39%), magnesium (17%), and zinc (16%). Vegetable oils (15%) and high-fat vegetable oil-based spreads (14%) were the top sources of polyunsaturated fat. High-fibre bread was the top source of fibre (27%) and iron (12%). Non-root vegetables were the top source of folate (14%) and vitamin C (22%). Sugar-sweetened beverages provided 21% of sucrose intake. Pork was a more important source of protein and sausage was a more important source of total fat and monounsaturated fat in boys than in girls. Vegetable oils provided a higher proportion of unsaturated fat and vitamin E among boys, whereas high-fat vegetable oil-based spreads provided a higher proportion of these nutrients among girls. Commonly recommended foods, such as skimmed milk, high-fibre grain products, vegetables, vegetable oil, and vegetable oil-based spreads, were important sources of several nutrients, whereas sugar-sweetened beverages provided the majority of sucrose intake among children. This knowledge can be used in improving health among children by dietary interventions, nutrition education, and health policy decision making.

  17. Interactions between atmospheric circulation, nutrient deposition, and tropical forest primary production (Invited)

    Science.gov (United States)

    Randerson, J. T.; Chen, Y.; Rogers, B. M.; Morton, D. C.; van der Werf, G.; Mahowald, N. M.

    2010-12-01

    Tropical forests influence regional and global climate by means of several pathways, including by modifying surface energy exchange and by forming clouds. High levels of precipitation, leaching, and soil weathering limit nutrient availability in these ecosystems. Phosphorus (P) is a key element limiting net primary production, and in some areas, including forests recovering from prior disturbance, nitrogen (N) also may limit some components of production. Here we quantified atmospheric P and N inputs to these forests from fires using satellite-derived estimates of emissions and atmospheric models. In Africa and South America, cross-biome transport of fire-emitted aerosols and reactive N gases from savannas and areas near the deforestation frontier increased deposition of P and N in interior forests. Equatorward atmospheric transport during the dry (fire) season in one hemisphere was linked with surface winds moving toward the inter-tropical convergence zone (ITCZ) in the other hemisphere. Deposition levels were higher in tropical forests in Africa than in South America because of large savanna areas with high levels of fire emissions in both southern and northern Africa. We conclude by describing a potential feedback loop by which equatorward transport of fire emissions, dust, and spores sustains the productivity of tropical forests. We specifically assessed evidence that savanna-to-forest atmospheric transport of nutrients increases forest productivity, height, and rates of evapotranspiration (ET). In parallel, we examined the degree to which increases in ET and surface roughness in tropical forests have the potential to strengthen several components of the Hadley circulation, including deep convection, equatorward return flow (near the surface), and the intensity of seasonal drought in the subtropics (thereby increasing fires). These interactions are important for understanding biogeochemical - climate interactions on millennial timescales and for quantifying how

  18. Metals, organic compounds, and nutrients in Long Island Sound: sources, magnitudes, trends, and impacts

    Science.gov (United States)

    Mullaney, John R.; Varekamp, J.C.; MCElroy, A.E.; Brsslin, V.T.

    2014-01-01

    Long Island Sound (LIS) is a relatively shallow estuary with a mean depth of 20 m (maximum depth 49 m) and a unique hydrology and history of pollutant loading. Those factors have contributed to a wide variety of contamination problems in its muddy sediments, aquatic life and water column. The LIS sediments are contaminated with a host of legacy and more recently released toxic compounds and elements related to past and present wastewater discharges and runoff. These include non-point and storm water runoff and groundwater discharges, whose character has changed over the years along with the evolution of its watershed and industrial history. Major impacts have resulted from the copious amounts of nutrients discharged into LIS through atmospheric deposition (N), domestic and industrial waste water flows, fertilizer releases, and urban runoff. All these sources and their effects are in essence the result of human presence and activities in the watershed, and the severity of pollutant loading and their impacts generally scales with total population in the watersheds surrounding LIS. Environmental legislation passed since the mid-to late 1900s (e.g., Clean Air Act, Clean Water Act) has had a beneficial effect, however, and contaminant loadings for many toxic organic and inorganic chemicals and nutrients have diminished over the last few decades (O’Shea and Brosnan 2000; Trench, et al, 2012; O’Connor and Lauenstein 2006; USEPA 2007). Major strides have been made in reducing the inflow of nutrients into LIS, but cultural eutrophication is still an ongoing problem and nutrient control efforts will need to continue. Nonetheless, LIS is still a heavily human impacted estuary (an ‘Urban Estuary’, as described for San Francisco Bay by Conomos, 1979), and severe changes in water quality and sediment toxicity as well as ecosystem shifts have been witnessed over the relatively short period since European colonization in the early 1600s (Koppelman et al., 1976).

  19. Soil nutrient and sediment loss as affected by erosion barriers and nutrient source in semi-arid Burkina Faso

    NARCIS (Netherlands)

    Zougmore, R.; Mando, A.; Stroosnijder, L.

    2009-01-01

    In semi-arid Sahel, soil erosion by water is one major factor accounting for negative nutrient balances in agricultural systems. A field experiment was conducted on a Ferric Lixisol in Burkina Faso to assess the effects of soil and water conservation barriers (stone rows or grass strips of

  20. Sources of nutrients to nearshore areas of a eutrophic estuary: Implications for nutrient-enhanced acidification in Puget Sound

    Science.gov (United States)

    Ocean acidification has recently been highlighted as a major stressor for coastal organisms. Further work is needed to assess the role of anthropogenic nutrient additions in eutrophied systems on local biological processes, and how this interacts with CO2emission-driven acidific...

  1. SPARROW models used to understand nutrient sources in the Mississippi/Atchafalaya River Basin

    Science.gov (United States)

    Robertson, Dale M.; Saad, David A.

    2013-01-01

    Nitrogen (N) and phosphorus (P) loading from the Mississippi/Atchafalaya River Basin (MARB) has been linked to hypoxia in the Gulf of Mexico. To describe where and from what sources those loads originate, SPAtially Referenced Regression On Watershed attributes (SPARROW) models were constructed for the MARB using geospatial datasets for 2002, including inputs from wastewater treatment plants (WWTPs), and calibration sites throughout the MARB. Previous studies found that highest N and P yields were from the north-central part of the MARB (Corn Belt). Based on the MARB SPARROW models, highest N yields were still from the Corn Belt but centered over Iowa and Indiana, and highest P yields were widely distributed throughout the center of the MARB. Similar to that found in other studies, agricultural inputs were found to be the largest N and P sources throughout most of the MARB: farm fertilizers were the largest N source, whereas farm fertilizers, manure, and urban inputs were dominant P sources. The MARB models enable individual N and P sources to be defined at scales ranging from SPARROW catchments (∼50 km2) to the entire area of the MARB. Inputs of P from WWTPs and urban areas were more important than found in most other studies. Information from this study will help to reduce nutrient loading from the MARB by providing managers with a description of where each of the sources of N and P are most important, thus providing a basis for prioritizing management actions and ultimately reducing the extent of Gulf hypoxia.

  2. Nutrient enrichment differentially affects body sizes of primary consumers and predators in a detritus-based stream

    Science.gov (United States)

    John M. Davis; Amy D. Rosemond; Sue L. Eggert; Wyatt F. Cross; J. Bruce. Wallace

    2010-01-01

    We assessed how a 5-yr nutrient enrichment affected the responses of different size classes of primary consumers and predators in a detritus-based headwater stream. We hypothesized that alterations in detritus availability because of enrichment would decrease the abundance and biomass of large-bodied consumers. In contrast, we found that 2 yr of enrichment increased...

  3. Modeling the Sensitivity of Primary Production in Lake Michigan to Nutrient Loads with and without Dreissenid Mussels

    Science.gov (United States)

    Dreissenid (quagga) mussels became established in large numbers in Lake Michigan beginning around 2004. Since then, significant changes have been observed in Lake Michigan open-water chlorophyll and nutrient concentrations, and in primary production. We updated the LM3-Eutro mode...

  4. Wool-waste as organic nutrient source for container-grown plants

    Energy Technology Data Exchange (ETDEWEB)

    Zheljazkov, Valtcho D. [Mississippi State University, North Mississippi Research and Extension Center, Verona, MS 38879 (United States)], E-mail: vj40@pss.msstate.edu; Stratton, Glenn W [Department of Plant and Animal Sciences and Department of Environmental Sciences, Nova Scotia Agricultural College, Truro, NS, B2N 5E3 (Canada); Pincock, James [Department of Chemistry, Dalhousie University, Halifax, NS, B3H 4J3 (Canada); Butler, Stephanie [Department of Plant and Animal Sciences and Department of Environmental Sciences, Nova Scotia Agricultural College, Truro, NS, B2N 5E3 (Canada); Jeliazkova, Ekaterina A [Mississippi State University, Department of Plant and Soil Sciences, Mississippi State, MS 39762 (United States); Nedkov, Nedko K [Research Institute for Roses and Aromatic Crops, 49 Osvobojdenie Blv., Kazanluk (Bulgaria); Gerard, Patrick D [Department of Applied Economics and Statistics, Clemson University, Clemson, SC 29634 (United States)

    2009-07-15

    A container experiment was conducted to test the hypothesis that uncomposted wool wastes could be used as nutrient source and growth medium constituent for container-grown plants. The treatments were: (1) rate of wool-waste application (0 or unamended control, 20, 40, 80, and 120 g of wool per 8-in. pot), (2) growth medium constituents [(2.1) wool plus perlite, (2.2) wool plus peat, and (2.3) wool plus peat plus perlite], and (3) plant species (basil and Swiss chard). A single addition of 20, 40, 80, or 120 g of wool-waste to Swiss chard (Beta vulgaris L.) and basil (Ocimum basilicum L.) in pots with growth medium provided four harvests of Swiss chard and five harvests of basil. Total basil yield from the five harvests was 1.6-5 times greater than the total yield from the unamended control, while total Swiss chard yield from the four harvests was 2-5 times greater relative to the respective unamended control. The addition of wool-waste to the growth medium increased Swiss chard and basil tissue N, and NO{sub 3}-N and NH{sub 4}-N in growth medium relative to the unamended control. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) microanalysis of wool fibers sampled at the end of the experiments indicated various levels of decomposition, with some fibers retaining their original surface structure. Furthermore, most of the wool fibers' surfaces contained significant concentrations of S and much less N, P, or K. SEM/EDX revealed that some plant roots grow directly on wool-waste fibers suggesting either (1) root directional growth towards sites with greater nutrient concentration and/or (2) a possible role for roots or root exudates in wool decomposition. Results from this study suggest that uncomposted wool wastes can be used as soil amendment, growth medium constituent, and nutrient source for container-grown plants.

  5. Wool-waste as organic nutrient source for container-grown plants

    International Nuclear Information System (INIS)

    Zheljazkov, Valtcho D.; Stratton, Glenn W.; Pincock, James; Butler, Stephanie; Jeliazkova, Ekaterina A.; Nedkov, Nedko K.; Gerard, Patrick D.

    2009-01-01

    A container experiment was conducted to test the hypothesis that uncomposted wool wastes could be used as nutrient source and growth medium constituent for container-grown plants. The treatments were: (1) rate of wool-waste application (0 or unamended control, 20, 40, 80, and 120 g of wool per 8-in. pot), (2) growth medium constituents [(2.1) wool plus perlite, (2.2) wool plus peat, and (2.3) wool plus peat plus perlite], and (3) plant species (basil and Swiss chard). A single addition of 20, 40, 80, or 120 g of wool-waste to Swiss chard (Beta vulgaris L.) and basil (Ocimum basilicum L.) in pots with growth medium provided four harvests of Swiss chard and five harvests of basil. Total basil yield from the five harvests was 1.6-5 times greater than the total yield from the unamended control, while total Swiss chard yield from the four harvests was 2-5 times greater relative to the respective unamended control. The addition of wool-waste to the growth medium increased Swiss chard and basil tissue N, and NO 3 -N and NH 4 -N in growth medium relative to the unamended control. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) microanalysis of wool fibers sampled at the end of the experiments indicated various levels of decomposition, with some fibers retaining their original surface structure. Furthermore, most of the wool fibers' surfaces contained significant concentrations of S and much less N, P, or K. SEM/EDX revealed that some plant roots grow directly on wool-waste fibers suggesting either (1) root directional growth towards sites with greater nutrient concentration and/or (2) a possible role for roots or root exudates in wool decomposition. Results from this study suggest that uncomposted wool wastes can be used as soil amendment, growth medium constituent, and nutrient source for container-grown plants.

  6. Seasonal variability of mixed layer in the central Arabian Sea and its implication on nutrients and primary productivity

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Narvekar, J.

    -1 Seasonal variability of mixed layer in the central Arabian Sea and its implication on nutrients and primary productivity S. Prasanna Kumar and Jayu Narvekar National Institute of Oceanography, Dona Paula, Goa-403 004, India... on a 2? x 4? grids up to a depth of 500m. Monthly mean temperature and salinity data were used to calculate the sigma-t values (UNESCO, 1981). We also used nitrate, chlorophyll a and primary productivity data in the upper 120m water column...

  7. Potential of domestic sewage effluent treated as a source of water and nutrients in hydroponic lettuce

    Directory of Open Access Journals (Sweden)

    Renata da Silva Cuba

    2015-07-01

    Full Text Available The search for alternative sources of water for agriculture makes the use of treated sewage sludge an important strategy for achieving sustainability. This study evaluated the feasibility of reusing treated sewage effluent as alternative source of water and nutrients for the hydroponic cultivation of lettuce (Lactuca sativa L. The experiment was conducted in the greenhouse of the Center for Agricultural Sciences - UFSCar, in Araras, SP. The cultivation took place from February to March 2014. The hydroponic system used was the Nutrient Film Technique, and included three treatments: 1 water supply and mineral fertilizers (TA; 2 use of effluent treated and complemented with mineral fertilizers based on results of previous chemical analysis (TRA; and 3 use of treated effluent (TR. The applied experimental design was four randomly distributed blocks. We evaluated the fresh weight, nutritional status, the microbiological quality of the culture, and the amount of mineral fertilizers used in the treatments. The fresh weights were subjected to analysis of variance and means were compared by the Tukey test at 5% probability. Only the TR treatment showed a significant difference in the evaluated variables, as symptoms of nutritional deficiencies in plants and significant reduction in fresh weights (p <0.01 were found. There was no detectable presence of Escherichia coli in any treatment, and it was possible to use less of some fertilizers in the TRA treatment compared to TA.

  8. Effect of three sources of nutrients on biomass and pigment production of freshwater microalgae Hyaloraphidium contortum

    Directory of Open Access Journals (Sweden)

    Caña, E.

    2016-05-01

    Full Text Available Multifunctionality of microalgae is becoming increasingly important, hence science develops new techniques to maximize their potential by providing food, sustainable and affordable fuels and innovative environmental solutions. In this study, we analyzed the effect of different nutrient sources (Nitrofoska®, Quimifol® and Guillard and sowing time on the kinetics of growth and pigment production of freshwater microalgae Hyaloraphidium contortum; besides of registering some physical and chemical variables in different growth mediums. Bioassays were performed in batch cultures by quadruplicate, continously maintaining and controlling temperature, ventilation and lighting. Growth was determined by cell count and production of pigments by spectrophotometry. The largest population densities and productivities per volume of culture were obtained in F/2 Guillard (9.7±0.2x107 cel mL-1 and 7.6x108 cel/L/ day and Nitrofoska® (8.7±0.5x107 cel mL-1 and 5.7x108 cel/L/day. The highest average chlorophyll a, chlorophyll b and total carotenoid concentration was achieved with foliar fertilizer Nitrofoska®, on days 18 and 24 (8, 3.29 and 2.2 μg mL-1, respectively, followed by the obtained by Guillard and Quimifol®. We conclude that this microalgae can be grown with commercial agricultural fertilizers as an alternative source of nutrients to produce biomass and pigments with applications in biotechnology and aquaculture industries.

  9. The Importance of Animal Source Foods for Nutrient Sufficiency in the Developing World: The Zambia Scenario.

    Science.gov (United States)

    Zhang, Zhiying; Goldsmith, Peter D; Winter-Nelson, Alex

    2016-05-05

    There have been successful interventions fortifying staple foods to mobilize micronutrients as well as agricultural efforts to raise yields of staple foods to increase food availability. Zambia serves as an interesting case study because since 1961 there has been a notable decline in the availability of animal source foods (ASFs) and pulses and a significant increase in the supply of cassava and vegetable oils. The shift in food availability was partly attributed to the agricultural success in high-yielding and drought-resistant varieties that made cassava and oil crops more affordable and readily available. In this research, we explore another policy strategy that involves ASF as a mechanism to help remedy micronutrient inadequacies in a population. A scenario modeling analysis compares the changes in the nutrient profile of the Zambian diet through adding either staple plant source foods (PSFs) or ASFs. The scenarios under study involve the addition of (1) 18 fl oz of whole cow's milk; (2) 60 g of beef, 30 g of chicken, and 5 g of beef liver; (3) milk plus meat; or (4) 83 g of maize flour, 123 g of cassava, and other staple PSF, that is, isocaloric to the "milk + meat" group. The findings alert program planners and policy makers to the value of increasing the availability, accessibility, and utilization of ASF to simultaneously address multiple nutrient deficiencies, as well as the nutrition challenges that remain when expanding the availability of plant-based staples. © The Author(s) 2016.

  10. Evaluation of glass leaching as nutrient source for microalgae growth; Evaluacion del comportamiento de vidrios lixiviados como nutrientes de algas

    Energy Technology Data Exchange (ETDEWEB)

    Grabska, N.; Tamayo, A.; Mazo, M. A.; Pascual, L.; Rubio, J.

    2015-10-01

    Three glasses with an elemental composition similar to the nutrient ratio required for Spirulina platensis growth and with different SiO{sub 2} content have been prepared. The glasses were crushed and sieved into 2 different fractions and the effect of the particle size has been studied in terms of the leaching kinetics of each element. The chemical analysis of the leaching water was used for obtaining the dissolution rate curves for each element taking part of the glass composition. From the calculation of the leaching rate constant and the exponential constant of the lixiviation reaction, it has been evaluated the Spirulina platensis growth in ambient normal conditions of light, temperature and pH of the growing media. It has been concluded that, either from the modification of the chemical composition of the glass or its particle size, it is possible to tune the delivery of the nutrients to match the growth rate of Spirulina platensis. (Author)

  11. Research on Primary Shielding Calculation Source Generation Codes

    Science.gov (United States)

    Zheng, Zheng; Mei, Qiliang; Li, Hui; Shangguan, Danhua; Zhang, Guangchun

    2017-09-01

    Primary Shielding Calculation (PSC) plays an important role in reactor shielding design and analysis. In order to facilitate PSC, a source generation code is developed to generate cumulative distribution functions (CDF) for the source particle sample code of the J Monte Carlo Transport (JMCT) code, and a source particle sample code is deveoped to sample source particle directions, types, coordinates, energy and weights from the CDFs. A source generation code is developed to transform three dimensional (3D) power distributions in xyz geometry to source distributions in r θ z geometry for the J Discrete Ordinate Transport (JSNT) code. Validation on PSC model of Qinshan No.1 nuclear power plant (NPP), CAP1400 and CAP1700 reactors are performed. Numerical results show that the theoretical model and the codes are both correct.

  12. Fueling primary productivity: nutrient return pathways from the deep ocean and their dependence on the Meridional Overturning Circulation

    Science.gov (United States)

    Palter, J. B.; Sarmiento, J. L.; Gnanadesikan, A.; Simeon, J.; Slater, D.

    2010-06-01

    In the Southern Ocean, mixing and upwelling in the presence of heat and freshwater surface fluxes transform subpycnocline water to lighter densities as part of the upward branch of the Meridional Overturning Circulation (MOC). One hypothesized impact of this transformation is the restoration of nutrients to the global pycnocline, without which biological productivity at low latitudes would be catastrophically reduced. Here we use a novel set of modeling experiments to explore the causes and consequences of the Southern Ocean nutrient return pathway. Specifically, we quantify the contribution to global productivity of nutrients that rise from the ocean interior in the Southern Ocean, the northern high latitudes, and by mixing across the low latitude pycnocline. In addition, we evaluate how the strength of the Southern Ocean winds and the parameterizations of subgridscale processes change the dominant nutrient return pathways in the ocean. Our results suggest that nutrients upwelled from the deep ocean in the Antarctic Circumpolar Current and subducted in Subantartic Mode Water support between 33 and 75% of global primary productivity between 30° S and 30° N. The high end of this range results from an ocean model in which the MOC is driven primarily by wind-induced Southern Ocean upwelling, a configuration favored due to its fidelity to tracer data, while the low end results from an MOC driven by high diapycnal diffusivity in the pycnocline. In all models, the high preformed nutrients subducted in the SAMW layer are converted rapidly (in less than 40 years) to remineralized nutrients, explaining previous modeling results that showed little influence of the drawdown of SAMW surface nutrients on atmospheric carbon concentrations.

  13. Dietary sources of energy and nutrient intake among children and adolescents with chronic kidney disease.

    Science.gov (United States)

    Chen, Wen; Ducharme-Smith, Kirstie; Davis, Laura; Hui, Wun Fung; Warady, Bradley A; Furth, Susan L; Abraham, Alison G; Betoko, Aisha

    2017-07-01

    Our purpose was to identify the main food contributors to energy and nutrient intake in children with chronic kidney disease (CKD). In this cross-sectional study of dietary intake assessed using Food Frequency Questionnaires (FFQ) in the Chronic Kidney Disease in Children (CKiD) cohort study, we estimated energy and nutrient intake and identified the primary contributing foods within this population. Completed FFQs were available for 658 children. Of those, 69.9% were boys, median age 12 (interquartile range (IQR) 8-15 years). The average daily energy intake was 1968 kcal (IQR 1523-2574 kcal). Milk was the largest contributor to total energy, protein, potassium, and phosphorus intake. Fast foods were the largest contributors to fat and sodium intake, the second largest contributors to energy intake, and the third largest contributors to potassium and phosphorus intake. Fruit contributed 12.0%, 8.7%, and 6.7% to potassium intake for children aged 2-5, 6-13, and 14-18 years old, respectively. Children with CKD consumed more sodium, protein, and calories but less potassium than recommended by the National Kidney Foundation (NKF) guidelines for pediatric CKD. Energy, protein, and sodium intake is heavily driven by consumption of milk and fast foods. Limiting contribution of fast foods in patients with good appetite may be particularly important for maintaining recommended energy and sodium intake, as overconsumption can increase the risk of obesity and cardiovascular complications in that population.

  14. Total primary production and the balance between benthic and pelagic plants in different nutrient regimes in a shallow estuary

    DEFF Research Database (Denmark)

    Markager, Svend Stiig; Krause-Jensen, Dorte; Dalsgaard, Tage

    on a large monitoring data set in combination with historical information we have quantified and compared the benthic and the pelagic primary production along nutrient gradients in space and time for the shallow estuary Limfjorden, Denmark. As expected, increases in nutrient load stimulated the pelagic...... was again reduced, and the ecosystem entered a phase of oligotrophication, pelagic GPP declined gradually while benthic GPP did not increase correspondingly leading to an decline in overall GPP. Instead the ecosystem showed a resistance or time lag against return to a clear water state with benthic...

  15. Eyewitness Culture and History: Primary Written Sources. The Iconoclast.

    Science.gov (United States)

    McMurtry, John

    1995-01-01

    Asserts that contemporary history and historiography is "official" history that ignores the daily struggles of people for their continued survival. Argues that, while public illiteracy has nearly disappeared, individuals are ignorant of the wealth of primary-source materials of other cultures' histories. (CFR)

  16. Primary Sources. Update: Teachers' Views on Common Core State Standards

    Science.gov (United States)

    Scholastic Inc. and the Bill & Melinda Gates Foundation, 2014

    2014-01-01

    Scholastic and the Bill & Melinda Gates Foundation fielded the third edition of the "Primary Sources" survey of America's teachers in July 2013 (see ED562664). Twenty thousand pre-K through grade 12 public school teachers responded, sharing their perspectives on issues important to their profession, including the Common Core State…

  17. Potentials of raw and cooked walnuts (Tetracapidium conophorum) as sources of valuable nutrients for good health.

    Science.gov (United States)

    Moyib, O K; Falegbe, O; Moyib, F R

    2015-12-01

    The present study estimated nutrient composition of walnuts before and after cooking with respect to its potential as valuable source of nutrients for daily intake. Walnut fruits were purchased from five different markets in Ijebu-Ode local government area and its environs. The fruits samples were divided into two portions, labelled R (for raw) and C (cooked). The C samples were cooked at 100 degrees C for 1 hr and allowed to cool to room temperature. The seeds of both C and R samples were ground and analyzed for proximate, macro and micro minerals using methods of Association of Official Chemists. The results obtained showed that both raw and cooked walnuts are rich in fat, iron (Fe), manganese (Mn), and copper (Cu) in amounts that are within daily recommended intake per 100 g of walnut seeds. They also contained appreciable levels of protein, phosphorus (P), calcium (Ca), and magnesium (Mg) but with low content of moisture (MC), carbohydrate, fiber, sodium (Na) and potassium (K). Boiling significantly affected the levels of protein, carbohydrate, ash, moisture content, fat, nitrogen, calcium, sodium, copper, zinc, phosphorus, potassium, manganese and iron The study reveals that walnut is nutritious due to its appreciable level of protein and presence of various essential and macro minerals. Its low content of sodium and potassium is beneficiary in hypertensive condition as snack. The study suggests future bio-fortification of walnut with zinc, which may bring about a co-increase in Ca and protein content.

  18. Primary calibration of coiled 103Pd brachytherapy sources

    International Nuclear Information System (INIS)

    Paxton, Adam B.; Culberson, Wesley S.; DeWerd, Larry A.; Micka, John A.

    2008-01-01

    Coiled 103 Pd brachytherapy sources have been developed by RadioMed Corporation for use as low-dose-rate (LDR) interstitial implants. The coiled sources are provided in integer lengths from 1 to 6 cm and address many common issues seen with traditional LDR brachytherapy sources. The current standard for determining the air-kerma strength (S K ) of low-energy LDR brachytherapy sources is the National Institute of Standards and Technology's Wide-Angle Free-Air Chamber (NIST WAFAC). Due to geometric limitations, however, the NIST WAFAC is unable to determine the S K of sources longer than 1 cm. This project utilized the University of Wisconsin's Variable-Aperture Free-Air Chamber (UW VAFAC) to determine the S K of the longer coiled sources. The UW VAFAC has shown agreement in S K values of 1 cm length coils to within 1% of those determined with the NIST WAFAC, but the UW VAFAC does not share the same geometric limitations as the NIST WAFAC. A new source holder was constructed to hold the coiled sources in place during measurements with the UW VAFAC. Correction factors for the increased length of the sources have been determined and applied to the measurements. Using the new source holder and corrections, the S K of 3 and 6 cm coiled sources has been determined. Corrected UW VAFAC data and ionization current measurements from well chambers have been used to determine calibration coefficients for use in the measurement of 3 and 6 cm coiled sources in well chambers. Thus, the UW VAFAC has provided the first transferable, primary measurement of low-energy LDR brachytherapy sources with lengths greater than 1 cm

  19. Simulated nutrient dissolution of Asian aerosols in various atmospheric waters: Potential links to marine primary productivity

    Science.gov (United States)

    Wang, Lingyan; Bi, Yanfeng; Zhang, Guosen; Liu, Sumei; Zhang, Jing; Xu, Zhaomeng; Ren, Jingling; Zhang, Guiling

    2017-09-01

    To probe the bioavailability and environmental mobility of aerosol nutrient elements (N, P, Si) in atmospheric water (rainwater, cloud and fog droplets), ten total suspended particulate (TSP) samples were collected at Fulong Mountain, Qingdao from prevailing air mass trajectory sources during four seasons. Then, a high time-resolution leaching experiment with simulated non-acidic atmospheric water (non-AAW, Milli-Q water, pH 5.5) and subsequently acidic atmospheric water (AAW, hydrochloric acid solution, pH 2) was performed. We found that regardless of the season or source, a monotonous decreasing pattern was observed in the dissolution of N, P and Si compounds in aerosols reacted with non-AAW, and the accumulated dissolved curves of P and Si fit a first-order kinetic model. No additional NO3- + NO2- dissolved out, while a small amount of NH4+ in Asian dust (AD) samples was released in AAW. The similar dissolution behaviour of P and Si from non-AAW to AAW can be explained by the Transition State Theory. The sources of aerosols related to various minerals were the natural reasons that affected the amounts of bioavailable phosphorus and silicon in aerosols (i.e., solubility), which can be explained by the dissolution rate constant of P and Si in non-AAW with lower values in mineral aerosols. The acid/particle ratio and particle/liquid ratio also have a large effect on the solubility of P and Si, which was implied by Pearson correlation analysis. Acid processing of aerosols may have great significance for marine areas with limited P and Si and post-acidification release increases of 1.1-10-fold for phosphorus and 1.2-29-fold for silicon. The decreasing mole ratio of P and Si in AAW indicates the possibility of shifting from a Si-limit to a P-limit in aerosols in the ocean, which promotes the growth of diatoms prior to other algal species.

  20. Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal.

    Science.gov (United States)

    Bu, Fan; Hu, Xiang; Xie, Li; Zhou, Qi

    2015-04-01

    The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-β-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating organisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and 61.8% (Day 65) when using cassava stillage and its anaerobic fermentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates (NURs) of the cassava by-products were in the range of 5.49-5.99 g N/(kg MLVSS⋅h) (MLVSS is mixed liquor volatile suspended solids) and 6.63-6.81 g N/(kg MLVSS⋅h), respectively. The improvement in BNR performance and the reduction in the amount of cassava stillage to be treated in-situ make cassava stillage and its anaerobic fermentation liquid attractive alternatives to sodium acetate as external carbon sources for BNR processes.

  1. Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal*

    Science.gov (United States)

    Bu, Fan; Hu, Xiang; Xie, Li; Zhou, Qi

    2015-01-01

    The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-β-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating organisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and 61.8% (Day 65) when using cassava stillage and its anaerobic fermentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates (NURs) of the cassava by-products were in the range of 5.49–5.99 g N/(kg MLVSS∙h) (MLVSS is mixed liquor volatile suspended solids) and 6.63–6.81 g N/(kg MLVSS∙h), respectively. The improvement in BNR performance and the reduction in the amount of cassava stillage to be treated in-situ make cassava stillage and its anaerobic fermentation liquid attractive alternatives to sodium acetate as external carbon sources for BNR processes. PMID:25845364

  2. LBA-ECO ND-08 Biomass, Nutrients, and Decomposition in Eucalyptus and Primary Forests

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set reports the concentrations of the nutrients nitrogen (N), phosphorus (P), magnesium (Mg), calcium (Ca), and potassium (K) in roots,...

  3. LBA-ECO ND-08 Biomass, Nutrients, and Decomposition in Eucalyptus and Primary Forests

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set reports the concentrations of the nutrients nitrogen (N), phosphorus (P), magnesium (Mg), calcium (Ca), and potassium (K) in roots, litterfall, leaves,...

  4. Evaluation of Net Primary Productivity and Carbon Allocation to Different Parts of Corn in Different Tillage and Nutrient Management Systems

    Directory of Open Access Journals (Sweden)

    esmat mohammadi

    2017-09-01

    Full Text Available Evaluation of net primary productivity and carbon allocation to different organs of corn under nutrient management and tillage systems Introduction Agriculture operations produce 10 to 20 percent of greenhouse gases. As a result of conventional operations of agriculture, greenhouse gases have been increased (Osborne et al., 2010. Therefor it is necessary to notice to carbon sequestration to reduce greenhouse gases emissions. In photosynthesis process, plants absorb CO2 and large amounts of organic carbon accumulate in their organs. Biochar is produced of pyrolysis of organic compounds. Biochar is an appropriate compound for improved of soil properties and carbon sequestration (Whitman and Lehmann, 2009; Smith et al., 2010. Conservation tillage has become an important technology in sustainable agriculture due to its benefits. So the aim of this study was to evaluate the effect of nutrient management and tillage systems on net primary production and carbon allocation to different organs of corn in Shahrood. Material and methods This study was conducted at the Shahrood University of Technology research farm. Experiment was done as split plot in randomized complete block design with three replications. Tillage systems with two levels (conventional tillage and minimum tillage were as the main factor and nutrient management in seven levels including (control, chemical fertilizer, manure, biochar, chemical fertilizer + manure, chemical fertilizer + biochar, manure + biochar were considered as sub plot. At the time of maturity of corn, was sampled from its aboveground and belowground biomasses. Carbon content of shoot, seed and root was considered almost 45 percent of yield of each of these biomasses and carbon in root exudates almost 65 percent of carbon in the root. Statistical analysis of the data was performed using SAS program. Comparison of means was conducted with LSD test at the 5% level. Results and discussion Effect of nutrient management was

  5. Digestate as nutrient source for biomass production of sida, lucerne and maize

    Science.gov (United States)

    Bueno Piaz Barbosa, Daniela; Nabel, Moritz; Horsch, David; Tsay, Gabriela; Jablonowski, Nicolai

    2014-05-01

    Biogas as a renewable energy source is supported in many countries driven by climate and energy policies. Nowadays, Germany is the largest biogas producer in the European Union. A sustainable resource management has to be considered within this growing scenario of biogas production systems and its environmental impacts. In this respect, studies aiming to enhance the management of biogas residues, which represents a valuable source of nutrients and organic fertilization, are needed. Our objective was to evaluate the digestate (biogas residue after fermentation process) application as nutrient source for biomass production of three different plants: sida (Sida hermaphrodita - Malvaceae), lucerne (Medicago sativa - Fabaceae) and maize (Zea mays - Poaceae). The digestate was collected from an operating biogas facility (fermenter volume 2500m³, ADRW Natur Power GmbH & Co.KG Titz/Ameln, Germany) composed of maize silage as the major feedstock, and minor amounts of chicken manure, with a composition of 3,29% N; 1,07% P; 3,42% K; and 41,2% C. An arable field soil (Endogleyic Stagnosol) was collected from 0-30 cm depth and 5 mm sieved. The fertilizer treatments of the plants were established in five replicates including digestate (application amount equivalent to 40 t ha-1) and NPK fertilizer (application amount equivalent to 200:100:300 kg ha-1) applications, according to the recommended agricultural doses, and a control (no fertilizer application). The digestate and the NPK fertilizer were thoroughly mixed with the soil in a rotatory shaker for 30 min. The 1L pots were filled with the fertilized soil and the seedlings were transplanted and grown for 30 days under greenhouse conditions (16 h day/8 h night: 24ºC/18ºC; 60% air humidity). After harvesting, the leaf area was immediately measured, and the roots were washed to allow above and below-ground biomass determination. Subsequently, shoots and roots were dried at 60ºC for 48 hours. The biomass and leaf area of sida

  6. Cultivation of Nannochloropsis salina using anaerobic digestion effluent as a nutrient source for biofuel production

    International Nuclear Information System (INIS)

    Cai, Ting; Park, Stephen Y.; Racharaks, Ratanachat; Li, Yebo

    2013-01-01

    Highlights: • Cultivation of Nannochloropsis salina with effluent of anaerobic digestion (AD). • The highest biomass yield was obtained at 6% AD effluent loading. • Lipid content and productivity decreased with increased effluent loading from 3% to 18%. • Biomass productivity increased by up to 49% as harvest ratio increased from 25% to 50%. - Abstract: The biomass and lipid productivities and the nutrient removal capacity of microalgae Nannochloropsis salina grown using anaerobically digested municipal wastewater effluent as a nutrient source were evaluated in this study. Results from bench-scale batch reactors showed that N. salina grew well under 3%, 6%, 12%, and 18% (v/v) anaerobic digestion (AD) effluent loading with the highest growth rate being 0.645 d −1 obtained at 6% AD effluent loading. The growth of N. salina decreased when the effluent loading was increased to 24%. The highest biomass productivity of 92 mg l −1 d −1 was obtained with 6% effluent loading. Three harvesting frequencies (1, 2, and 3 d intervals) and two harvesting ratios (25% and 50%, v/v) were tested in semi-continuous bench-scale reactors with 6% effluent loading. The highest lipid productivity of 38.7 mg l −1 d −1 was achieved with a 2-d harvesting interval and 50% harvesting ratio, where nitrogen and phosphorus were removed at rates of 35.3 mg l −1 d −1 and 3.8 mg l −1 d −1 , respectively. The fatty acid (FA) profile showed that palmitic acid (C16:0), palmitoleic acid (C16:1), and eicosapentaenoic acid (C20:5) were the major components, accounting for 32.1%, 26%, and 15.7% of the total FAs, respectively

  7. Lentil and Kale: Complementary Nutrient-Rich Whole Food Sources to Combat Micronutrient and Calorie Malnutrition

    Directory of Open Access Journals (Sweden)

    Megan Migliozzi

    2015-11-01

    Full Text Available Lentil (Lens culinaris Medik. is a nutritious food and a staple for millions of people. Not only are lentils a good source of energy, they also contain a range of micronutrients and prebiotic carbohydrates. Kale (Brassica oleracea v. acephala has been considered as a health food, but its full range of benefits and composition has not been extensively studied. Recent studies suggest that foods are enrich in prebiotic carbohydrates and dietary fiber that can potentially reduce risks of non-communicable diseases, including obesity, cancer, heart disease, and diabetes. Lentil and kale added to a cereal-based diet would enhance intakes of essential minerals and vitamins to combat micronutrient malnutrition. This review provides an overview of lentil and kale as a complementary nutrient-rich whole food source to combat global malnutrition and calorie issues. In addition, prebiotic carbohydrate profiles and the genetic potential of these crops for further micronutrient enrichment are briefly discussed with respect to developing sustainable and nutritious food systems.

  8. Lentil and Kale: Complementary Nutrient-Rich Whole Food Sources to Combat Micronutrient and Calorie Malnutrition.

    Science.gov (United States)

    Migliozzi, Megan; Thavarajah, Dil; Thavarajah, Pushparajah; Smith, Powell

    2015-11-11

    Lentil (Lens culinaris Medik.) is a nutritious food and a staple for millions of people. Not only are lentils a good source of energy, they also contain a range of micronutrients and prebiotic carbohydrates. Kale (Brassica oleracea v. acephala) has been considered as a health food, but its full range of benefits and composition has not been extensively studied. Recent studies suggest that foods are enrich in prebiotic carbohydrates and dietary fiber that can potentially reduce risks of non-communicable diseases, including obesity, cancer, heart disease, and diabetes. Lentil and kale added to a cereal-based diet would enhance intakes of essential minerals and vitamins to combat micronutrient malnutrition. This review provides an overview of lentil and kale as a complementary nutrient-rich whole food source to combat global malnutrition and calorie issues. In addition, prebiotic carbohydrate profiles and the genetic potential of these crops for further micronutrient enrichment are briefly discussed with respect to developing sustainable and nutritious food systems.

  9. Nutrient Losses from Non-Point Sources or from Unidentified Point Sources? Application Examples of the Smartphone Based Nitrate App.

    Science.gov (United States)

    Rozemeijer, J.; Ekkelenkamp, R.; van der Zaan, B.

    2017-12-01

    In 2016 Deltares launched the free to use Nitrate App which accurately reads and interprets nitrate test strips. The app directly displays the measured concentration and gives the option to share the result. Shared results are visualised in map functionality within the app and online. Since its introduction we've been seeing an increasing number of nitrate app applications. In this presentation we show some unanticipated types of application. The Nitrate App was originally intended to enable farmers to measure nitrate concentrations on their own farms. This may encourage farmers to talk to specialists about the right nutrient best management practices (BMP's) for their farm. Several groups of farmers have recently started to apply the Nitrate App and to discuss their results with each other and with the authorities. Nitrate concentration routings in catchments have proven to be another useful application. Within a day a person can generate a catchment scale nitrate concentration map identifying nitrate loss hotspots. In several routings in agricultural catchments clear point sources were found, for example at small scale manure processing plants. These routings proved that the Nitrate App can help water managers to target conservation practices more accurately to areas with the highest nitrate concentrations and loads. Other current applications are the screening of domestic water wells in California, the collection of extra measurements (also pH and NH4) in the National Monitoring Network for the Evaluation of the Manure Policy in the Netherlands, and several educational initiatives in cooperation with schools and universities.

  10. THE DIGESTIBILITY OF NUTRIENTS AT DIFFERENT LEVELS AND SOURCES OF LIPIDS IN DUCK DIETS

    Directory of Open Access Journals (Sweden)

    M.Yu. Sychov

    2016-04-01

    Full Text Available The estimation of digestibility of nutrients in ducklings was performed by use of feed contained the lipids from different levels and sources. Experimental studies were conducted in terms of problem research laboratory of feed additives of National Agriculture University of Ukraine. The material for scientific experiments was the ducklings of cross STAR 53 H.Y. Experiment was carried out by group-analog method. We determined the optimal content of crude fat in fodder of young ducks at the first stage of experiment and the best source of lipids at second stage. We increased the crude fat in duckling feed by the introduction of sunflower oil at first stage. The amount of fat in the duck feed was 5% in control group and this were 3% and 7% in group II and III. The ducks from experimental groups received feed with sunflower oil at the second stage of experiment, the ducks of group II and III obtained feed from soya, rapeseed, and palm fat. Feeding the ducks was done per group twice per day – in morning and evening. It was registered that the feeding of 8-14 days ducks by food with crude fat of 7% plausible increased the digestibility of protein by 3.2%, of fat by 5.1%, and nitrogen-free extractives matters by 2.7%. At the same time the use of feed for 36-42 days ducks with crude fat of 7% allows to get the best results with the more higher level of protein and fat digestibility by 4.9% and 4.8% respectively. The use of feed with the addition of soybean oil for duck feeding have a positive effect towards increasing the level of digestibility of organic matter, protein, fat, and fiber in all the duck age groups. At the same time the use of feed containing palm oil reduces the digestibility of fat by 4,1-6,7%  compared to control group, that obtained feed with sunflower oil . We confirmed the prospect of further research in order to to establish the optimal ratio of saturated and unsaturated fatty acids in the diet of ducks and to determine their

  11. Production of Bacterial Cellulose by Gluconacetobacter hansenii Using Corn Steep Liquor As Nutrient Sources

    Directory of Open Access Journals (Sweden)

    Andrea F. S. Costa

    2017-10-01

    Full Text Available Cellulose is mainly produced by plants, although many bacteria, especially those belonging to the genus Gluconacetobacter, produce a very peculiar form of cellulose with mechanical and structural properties that can be exploited in numerous applications. However, the production cost of bacterial cellulose (BC is very high to the use of expensive culture media, poor yields, downstream processing, and operating costs. Thus, the purpose of this work was to evaluate the use of industrial residues as nutrients for the production of BC by Gluconacetobacter hansenii UCP1619. BC pellicles were synthesized using the Hestrin–Schramm (HS medium and alternative media formulated with different carbon (sugarcane molasses and acetylated glucose and nitrogen sources [yeast extract, peptone, and corn steep liquor (CSL]. A jeans laundry was also tested. None of the tested sources (beside CSL worked as carbon and nutrient substitute. The alternative medium formulated with 1.5% glucose and 2.5% CSL led to the highest yield in terms of dry and hydrated mass. The BC mass produced in the alternative culture medium corresponded to 73% of that achieved with the HS culture medium. The BC pellicles demonstrated a high concentration of microfibrils and nanofibrils forming a homogenous, compact, and three-dimensional structure. The biopolymer produced in the alternative medium had greater thermal stability, as degradation began at 240°C, while degradation of the biopolymer produced in the HS medium began at 195°C. Both biopolymers exhibited high crystallinity. The mechanical tensile test revealed the maximum breaking strength and the elongation of the break of hydrated and dry pellicles. The dry BC film supported up to 48 MPa of the breaking strength and exhibited greater than 96.98% stiffness in comparison with the hydrated film. The dry film supported up to 48 MPa of the breaking strength and exhibited greater than 96.98% stiffness in comparison with the hydrated film

  12. Multiple-source tracking: Investigating sources of pathogens, nutrients, and sediment in the Upper Little River Basin, Kentucky, water years 2013–14

    Science.gov (United States)

    Crain, Angela S.; Cherry, Mac A.; Williamson, Tanja N.; Bunch, Aubrey R.

    2017-09-20

    The South Fork Little River (SFLR) and the North Fork Little River (NFLR) are two major headwater tributaries that flow into the Little River just south of Hopkinsville, Kentucky. Both tributaries are included in those water bodies in Kentucky and across the Nation that have been reported with declining water quality. Each tributary has been listed by the Kentucky Energy and Environment Cabinet—Kentucky Division of Water in the 303(d) List of Waters for Kentucky Report to Congress as impaired by nutrients, pathogens, and sediment for contact recreation from point and nonpoint sources since 2002. In 2009, the Kentucky Energy and Environment Cabinet—Kentucky Division of Water developed a pathogen total maximum daily load (TMDL) for the Little River Basin including the SFLR and NFLR Basins. Future nutrient and suspended-sediment TMDLs are planned once nutrient criteria and suspended-sediment protocols have been developed for Kentucky. In this study, different approaches were used to identify potential sources of fecal-indicator bacteria (FIB), nitrate, and suspended sediment; to inform the TMDL process; and to aid in the implementation of effective watershed-management activities. The main focus of source identification was in the SFLR Basin.To begin understanding the potential sources of fecal contamination, samples were collected at 19 sites for densities of FIB (E. coli) in water and fluvial sediment and at 11 sites for Bacteroidales genetic markers (General AllBac, human HF183, ruminant BoBac, canid BacCan, and waterfowl GFD) during the recreational season (May through October) in 2013 and 2014. Results indicated 34 percent of all E. coli water samples (n=227 samples) did not meet the U.S. Environmental Protection Agency 2012 recommended national criteria for primary recreational waters. No criterion currently exists for E. coli in fluvial sediment. By use of the Spearman’s rank correlation test, densities of FIB in fluvial sediments were observed to have a

  13. Seasonal changes in nutrient limitation and nitrate sources in the green macroalga Ulva lactuca at sites with and without green tides in a northeastern Pacific embayment.

    Science.gov (United States)

    Van Alstyne, Kathryn L

    2016-02-15

    In Penn Cove, ulvoid green algal mats occur annually. To examine seasonal variation in their causes, nitrogen and carbon were measured in Ulva lactuca in May, July, and September and stable nitrogen and oxygen isotope ratios were quantified in U. lactuca, Penn Cove seawater, upwelled water from Saratoga Passage, water near the Skagit River outflow, and effluents from wastewater treatment facilities. Ulvoid growth was nitrogen limited and the sources of nitrogen used by the algae changed during the growing season. Algal nitrogen concentrations were 0.85-4.55% and were highest in September and at sites where algae were abundant. Upwelled waters were the primary nitrogen source for the algae, but anthropogenic sources also contributed to algal growth towards the end of the growing season. This study suggests that small nitrogen inputs can result in crossing a "tipping point", causing the release of nutrient limitation and localized increases in algal growth. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Hydrogen Production Costs of Various Primary Energy Sources

    International Nuclear Information System (INIS)

    Choi, Jae Hyuk; Tak, Nam Il; Kim, Yong Hee; Park, Won Seok

    2005-11-01

    Many studies on the economical aspects of hydrogen energy technologies have been conducted with the increase of the technical and socioeconomic importance of the hydrogen energy. However, there is still no research which evaluates the economy of hydrogen production from the primary energy sources in consideration of Korean situations. In this study, the hydrogen production costs of major primary energy sources are compared in consideration of the Korean situations such as feedstock price, electricity rate, and load factor. The evaluation methodology is based on the report of the National Academy of Science (NAS) of U.S. The present study focuses on the possible future technology scenario defined by NAS. The scenario assumes technological improvement that may be achieved if present research and development (R and D) programs are successful. The production costs by the coal and natural gas are 1.1 $/kgH 2 and 1.36 $/kgH 2 , respectively. However, the fossil fuels are susceptible to the price variation depending on the oil and the raw material prices, and the hydrogen production cost also depends on the carbon tax. The economic competitiveness of the renewable energy sources such as the wind, solar, and biomass are relatively low when compared with that of the other energy sources. The estimated hydrogen production costs from the renewable energy sources range from 2.35 $/kgH 2 to 6.03 $/kgH 2 . On the other hand, the production cost by nuclear energy is lower than that of natural gas or coal when the prices of the oil and soft coal are above $50/barrel and 138 $/ton, respectively. Taking into consideration the recent rapid increase of the oil and soft coal prices and the limited fossil resource, the nuclear-hydrogen option appears to be the most economical way in the future

  15. Vitamins and nutrients as primary treatments in experimental brain injury: Clinical implications for nutraceutical therapies.

    Science.gov (United States)

    Vonder Haar, Cole; Peterson, Todd C; Martens, Kris M; Hoane, Michael R

    2016-06-01

    With the numerous failures of pharmaceuticals to treat traumatic brain injury in humans, more researchers have become interested in combination therapies. This is largely due to the multimodal nature of damage from injury, which causes excitotoxicity, oxidative stress, edema, neuroinflammation and cell death. Polydrug treatments have the potential to target multiple aspects of the secondary injury cascade, while many previous therapies focused on one particular aspect. Of specific note are vitamins, minerals and nutrients that can be utilized to supplement other therapies. Many of these have low toxicity, are already FDA approved and have minimal interactions with other drugs, making them attractive targets for therapeutics. Over the past 20 years, interest in supplementation and supraphysiologic dosing of nutrients for brain injury has increased and indeed many vitamins and nutrients now have a considerable body of the literature backing their use. Here, we review several of the prominent therapies in the category of nutraceutical treatment for brain injury in experimental models, including vitamins (B2, B3, B6, B9, C, D, E), herbs and traditional medicines (ginseng, Gingko biloba), flavonoids, and other nutrients (magnesium, zinc, carnitine, omega-3 fatty acids). While there is still much work to be done, several of these have strong potential for clinical therapies, particularly with regard to polydrug regimens. This article is part of a Special Issue entitled SI:Brain injury and recovery. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Sanitary landfill leachate as a source of nutrients on the initial growth of sunflower plants

    Directory of Open Access Journals (Sweden)

    Francisco H. Nunes Júnior

    Full Text Available ABSTRACT The aim of this study was to evaluate the initial growth of sunflower seedlings under different concentrations of sanitary landfill leachate, considering the feasibility of its use as source of nutrients for agricultural production. Biometric and vigor variables were analyzed through the measurements of collar diameter, shoot height, number of leaves and shoot and root fresh and dry matters, from January to February 2015. The experimental design was completely randomized in a 5 x 4 factorial scheme: five leachate concentrations (0, 40, 60, 80 and 100 kg N ha-1 x four harvest periods (14, 21, 25 and 29 days after sowing, with five replicates each containing two plants. The data were subjected to analysis of variance and polynomial regression, and the results of the last harvest (29 DAS were compared by Tukey test (p ≤ 0.05. The use of sanitary landfill leachate increased all analyzed variables in sunflower plants when compared to the control plants (without leachate, especially in the treatment of 100 kg N ha-1. There was no inhibitory effect of the leachate on the initial growth of sunflower seedlings under adopted experimental conditions.

  17. Hydrogen Production Costs of Various Primary Energy Sources

    International Nuclear Information System (INIS)

    Choi, Jae Hyuk; Tak, Nam Il; Kim, Yong Hee; Park, Won Seok

    2005-01-01

    The limited resource and environmental impacts of fossil fuels are becoming more and more serious problems in the world. Consequently, hydrogen is in the limelight as a future alternative energy due to its clean combustion and inexhaustibility and a transition from the traditional fossil fuel system to a hydrogen-based energy system is under considerations. Several countries are already gearing the industries to the hydrogen economy to cope with the limitations of the current fossil fuels. Unfortunately, hydrogen has to be chemically separated from the hydrogen compounds in nature such as water by using some energy sources. In this paper, the hydrogen production costs of major primary energy sources are compared in consideration of the Korean situations. The evaluation methodology is based on the report of the National Academy of Science (NAS) of U.S

  18. Pulp tissue from primary teeth: new source of stem cells

    Directory of Open Access Journals (Sweden)

    Paloma Dias Telles

    2011-06-01

    Full Text Available SHED (stem cells from human exfoliated deciduous teeth represent a population of postnatal stem cells capable of extensive proliferation and multipotential differentiation. Primary teeth may be an ideal source of postnatal stem cells to regenerate tooth structures and bone, and possibly to treat neural tissue injury or degenerative diseases. SHED are highly proliferative cells derived from an accessible tissue source, and therefore hold potential for providing enough cells for clinical applications. In this review, we describe the current knowledge about dental pulp stem cells and discuss tissue engineering approaches that use SHED to replace irreversibly inflamed or necrotic pulps with a healthy and functionally competent tissue that is capable of forming new dentin.

  19. Potential for nutrient recovery and biogas production from blackwater, food waste and greywater in urban source control systems.

    Science.gov (United States)

    Kjerstadius, H; Haghighatafshar, S; Davidsson, Å

    2015-01-01

    In the last decades, the focus on waste and wastewater treatment systems has shifted towards increased recovery of energy and nutrients. Separation of urban food waste (FW) and domestic wastewaters using source control systems could aid this increase; however, their effect on overall sustainability is unknown. To obtain indicators for sustainability assessments, five urban systems for collection, transport, treatment and nutrient recovery from blackwater, greywater and FW were investigated using data from implementations in Sweden or northern Europe. The systems were evaluated against their potential for biogas production and nutrient recovery by the use of mass balances for organic material, nutrients and metals over the system components. The resulting indicators are presented in units suitable for use in future sustainability studies or life-cycle assessment of urban waste and wastewater systems. The indicators show that source control systems have the potential to increase biogas production by more than 70% compared with a conventional system and give a high recovery of phosphorus and nitrogen as biofertilizer. The total potential increase in gross energy equivalence for source control systems was 20-100%; the greatest increase shown is for vacuum-based systems.

  20. Effects of different sources of protein on digestive characteristics, microbial efficiency, and nutrient flow in dairy goats

    Directory of Open Access Journals (Sweden)

    Nivea Regina de Oliveira Felisberto

    2011-10-01

    Full Text Available Diets formulated with protein sources presenting different resistance to ruminal degradation were compared by evaluating ruminal parameters, production and microbial efficiency and nutrients flow to the omasum in goats. Eight rumen cannulated non-lactating, non-pregnant goats were distributed in a 4 × 4 Latin square design with two replicates. Treatments consisted of four diets where different sources of plant protein accounted for the major protein source named soybean meal, source of higher ruminal degradability, and three other sources of higher resistance of degradation: roasted soybean, corn gluten meal, and cottonseed cake. Amounts of rumen protein were similar among rations; however, flows of dry matter, protein and non-fiber carbohydrate to omasum were higher for diets with protein source with reduced rumen degradation rate. Higher values of rumen ammonia were obtained by using ration with soybean meal as major source of protein. Higher values of pH were obtained for rations with roasted soybean e cottonseed cake. Regarding kinetic of transit, similar values were found among rations. Diets with protein sources presenting reduced ruminal degradation increase nutrients flow to the omasum in goats and alter digestive parameters such as pH and ammonia without compromising bacteria growth and efficiency, which grants their use for dairy goats with similar efficiency to rations using more degradable sources of protein.

  1. Characterization of selenium in ambient aerosols and primary emission sources.

    Science.gov (United States)

    De Santiago, Arlette; Longo, Amelia F; Ingall, Ellery D; Diaz, Julia M; King, Laura E; Lai, Barry; Weber, Rodney J; Russell, Armistead G; Oakes, Michelle

    2014-08-19

    Atmospheric selenium (Se) in aerosols was investigated using X-ray absorption near-edge structure (XANES) spectroscopy and X-ray fluorescence (XRF) microscopy. These techniques were used to determine the oxidation state and elemental associations of Se in common primary emission sources and ambient aerosols collected from the greater Atlanta area. In the majority of ambient aerosol and primary emission source samples, the spectroscopic patterns as well as the absence of elemental correlations suggest Se is in an elemental, organic, or oxide form. XRF microscopy revealed numerous Se-rich particles, or hotspots, accounting on average for ∼16% of the total Se in ambient aerosols. Hotspots contained primarily Se(0)/Se(-II). However, larger, bulk spectroscopic characterizations revealed Se(IV) as the dominant oxidation state in ambient aerosol, followed by Se(0)/Se(-II) and Se(VI). Se(IV) was the only observed oxidation state in gasoline, diesel, and coal fly ash, while biomass burning contained a combination of Se(0)/Se(-II) and Se(IV). Although the majority of Se in aerosols was in the most toxic form, the Se concentration is well below the California Environmental Protection Agency chronic exposure limit (∼20000 ng/m(3)).

  2. Sediment and Nutrient Sources as well as Interspecific Competition Control Growth of 2 Common Species of Coral Reef Macroalgae

    Science.gov (United States)

    Moore, T.; Fong, P.; Cuker, B.

    2016-02-01

    Aquatic communities worldwide are increasingly subjected to multiple anthropogenic stressors that often result in shifts in structure and function. On coral reefs, human impacts have been associated with phase-shifts from coral to algal domination. We hypothesized that the proliferation of these algal communities, especially on fringing reefs, may be facilitated by human alterations in nutrient enrichment and input of sediments from developed watersheds, which may also influence competitive outcomes among dominant algal species. To evaluate how changes in these abiotic stressors as well as competition may affect the growth of 2 common species of calcifying coral reef algae, Galaxaura fasciculata and Padina boryana, we conducted 3 separate 2 factor mesocosm experiments modeling fringing reefs in Moorea, French Polynesia. In the first experiment, we varied sediment source (marine vs. terrestrial) and water column nutrients (ambient vs. enriched) for each species separately and measured growth after 7 days. While both algae grew faster in enriched compared to ambient nutrients, P. boryana performed best with marine sediment (+27% change in biomass) and G. fasciculata with terrestrial sediment (+14% change in biomass). Next, we varied sediment source (as above) as well as sediment nutrients (ambient/enriched) for each species. While P. boryana lost 44% biomass in the eutrophic terrestrial sediment treatment, G. fasciculata performed the best and gained 19% biomass. Finally, we varied competition (alone/together) and terrestrial sediment nutrients (ambient/enriched). Over the 7 day period, P. boryana lost 64% biomass when in competition with G. fasciculata in the enriched treatment while G. fasciculata gained 38% biomass when in competition with P. boryana in the ambient treatment. These results indicate that, while growth of both species of macroalgae was regulated by nutrients, sediments, and competition, each responded uniquely to these controlling factors.

  3. Effects of salt pond restoration on benthic flux: Sediment as a source of nutrients to the water column

    Science.gov (United States)

    Topping, Brent R.; Kuwabara, James S.; Carter, James L.; Garrettt, Krista K.; Mruz, Eric; Piotter, Sarah; Takekawa, John Y.

    2016-01-01

    Understanding nutrient flux between the benthos and the overlying water (benthic flux) is critical to restoration of water quality and biological resources because it can represent a major source of nutrients to the water column. Extensive water management commenced in the San Francisco Bay, Beginning around 1850, San Francisco Bay wetlands were converted to salt ponds and mined extensively for more than a century. Long-term (decadal) salt pond restoration efforts began in 2003. A patented device for sampling porewater at varying depths, to calculate the gradient, was employed between 2010 and 2012. Within the former ponds, the benthic flux of soluble reactive phosphorus and that of dissolved ammonia were consistently positive (i.e., moving out of the sediment into the water column). The lack of measurable nitrate or nitrite concentration gradients across the sediment-water interface suggested negligible fluxes for dissolved nitrate and nitrite. The dominance of ammonia in the porewater indicated anoxic sediment conditions, even at only 1 cm depth, which is consistent with the observed, elevated sediment oxygen demand. Nearby openestuary sediments showed much lower benthic flux values for nutrients than the salt ponds under resortation. Allochthonous solute transport provides a nutrient advective flux for comparison to benthic flux. For ammonia, averaged for all sites and dates, benthic flux was about 80,000 kg/year, well above the advective flux range of −50 to 1500 kg/year, with much of the variability depending on the tidal cycle. By contrast, the average benthic flux of soluble reactive phosphorus was about 12,000 kg/year, of significant magnitude, but less than the advective flux range of 21,500 to 30,000 kg/year. These benthic flux estimates, based on solute diffusion across the sediment-water interface, reveal a significant nutrient source to the water column of the pond which stimulates algal blooms (often autotrophic). This benthic source may be

  4. The effect of primary sedimentation on full-scale WWTP nutrient removal performance.

    Science.gov (United States)

    Puig, S; van Loosdrecht, M C M; Flameling, A G; Colprim, J; Meijer, S C F

    2010-06-01

    Traditionally, the performance of full-scale wastewater treatment plants (WWTPs) is measured based on influent and/or effluent and waste sludge flows and concentrations. Full-scale WWTP data typically have a high variance which often contains (large) measurement errors. A good process engineering evaluation of the WWTP performance is therefore difficult. This also makes it usually difficult to evaluate effect of process changes in a plant or compare plants to each other. In this paper we used a case study of a full-scale nutrient removing WWTP. The plant normally uses presettled wastewater, as a means to increase the nutrient removal the plant was operated for a period by-passing raw wastewater (27% of the influent flow). The effect of raw wastewater addition has been evaluated by different approaches: (i) influent characteristics, (ii) design retrofit, (iii) effluent quality, (iv) removal efficiencies, (v) activated sludge characteristics, (vi) microbial activity tests and FISH analysis and, (vii) performance assessment based on mass balance evaluation. This paper demonstrates that mass balance evaluation approach helps the WWTP engineers to distinguish and quantify between different strategies, where others could not. In the studied case, by-passing raw wastewater (27% of the influent flow) directly to the biological reactor did not improve the effluent quality and the nutrient removal efficiency of the WWTP. The increase of the influent C/N and C/P ratios was associated to particulate compounds with low COD/VSS ratio and a high non-biodegradable COD fraction. Copyright 2010 Elsevier Ltd. All rights reserved.

  5. Water-quality assessment of the Lower Susquehanna River Basin, Pennsylvania and Maryland; sources, characteristics, analysis and limitations of nutrient and suspended-sediment data, 1975-90

    Science.gov (United States)

    Hainly, R.A.; Loper, C.A.

    1997-01-01

    This report describes analyses of available information on nutrients and suspended sediment collected in the Lower Susquehanna River Basin during water years 1975-90. Most of the analyses were applied to data collected during water years 1980-89. The report describes the spatial and temporal availability of nutrient and suspended-sediment data and presents a preliminary concept of the spatial and temporal patterns of concentrations and loads within the basin. Where data were available, total and dissolved forms of nitrogen and phosphorus species from precipitation, surface water, ground water, and springwater, and bottom material from streams and reservoirs were evaluated. Suspended-sediment data from streams also were evaluated. The U.S. Geological Survey National Water Information System (NWIS) database was selected as the primary database for the analyses. Precipitation-quality data from the National Atmospheric Deposition Program (NADP) and bottom-material-quality data from the National Uranium Resource Evaluation (NURE) were used to supplement the water-quality data from NWIS. Concentrations of nutrients were available from 3 precipitation sites established for longterm monitoring purposes, 883 wells (854 synoptic areal survey sites and 29 project and research sites), 23 springs (17 synoptic areal survey sites and 6 project and research sites), and 894 bottom-material sites (840 synoptic areal survey sites and 54 project and research sites). Concentrations of nutrients and (or) suspended sediment were available from 128 streams (36 long-term monitoring sites, 51 synoptic areal survey sites, and 41 project and research sites). Concentrations of nutrients and suspended sediment in streams varied temporally and spatially and were related to land use, agricultural practices, and streamflow. A general north-to-south pattern of increasing median nitrate concentrations, from 2 to 5 mg/L, was detected in samples collected in study unit streams. In streams that drain

  6. Physics and national socialism an anthology of primary sources

    CERN Document Server

    1996-01-01

    This anthology of primary sources is a collection of 121 documents in English translation portraying the role of physics, both perceived and actual, in the Nazi state. These texts were written predominantly by influential German scientists, particularly physicists, both inside and outside Germany in the period from 1933 to 1945. The semipopular articles, private correspondence, and official memoranda selected for the volume reflect the contemporary developments in science as well as the change in political climate and working conditions after the National Socialists' rise to power. The extensive annotation is clearly distinguished from the original text, and the appendix provides an aid to the reader with biographical information on the more important figures and brief outlines of frequently mentioned institutions, journals and companies. The introduction surveys the latest results in the secondary literature.   ------    (…) the envisaged audience includes not only scholars and students of science, hist...

  7. Nutrient Patterns and Their Food Sources in Older Persons from France and Quebec: Dietary and Lifestyle Characteristics

    Directory of Open Access Journals (Sweden)

    Benjamin Allès

    2016-04-01

    Full Text Available Background: Dietary and nutrient patterns have been linked to health outcomes related to aging. Food intake is influenced by environmental and genetic factors. The aim of the present study was to compare nutrient patterns across two elderly populations sharing a common ancestral cultural background, but living in different environments. Methods: The diet quality, lifestyle and socioeconomic characteristics of participants from the Three-City Study (3C, France, n = 1712 and the Québec Longitudinal Study on Nutrition and Successful Aging (NuAge, Quebec, Canada, n = 1596 were analyzed. Nutrient patterns and their food sources were identified in the two samples using principal component analysis. Diet quality was compared across sample-specific patterns by describing weekly food intake and associations with the Canadian Healthy Eating Index (C-HEI. Results: Three nutrient patterns were retained in each study: a healthy, a Western and a more traditional pattern. These patterns accounted for 50.1% and 53.5% of the total variance in 3C and NuAge, respectively. Higher education and non-physical occupations over lifetime were associated with healthy patterns in both studies. Other characteristics such as living alone, having a body mass index lower than 25 and being an ex-smoker were associated with the healthy pattern in NuAge. No association between these characteristics and the nutrient patterns was noted in 3C. The healthy and Western patterns from each sample also showed an inverse association with C-HEI. Conclusion: The two healthy patterns showed important similarities: adequate food variety, consumption of healthy foods and associations with common sociodemographic factors. This work highlights that nutrient patterns derived using a posteriori methods may be useful to compare the nutritional quality of the diet of distinct populations.

  8. Nutrient Patterns and Their Food Sources in Older Persons from France and Quebec: Dietary and Lifestyle Characteristics.

    Science.gov (United States)

    Allès, Benjamin; Samieri, Cécilia; Lorrain, Simon; Jutand, Marthe-Aline; Carmichael, Pierre-Hugues; Shatenstein, Bryna; Gaudreau, Pierrette; Payette, Hélène; Laurin, Danielle; Barberger-Gateau, Pascale

    2016-04-19

    Dietary and nutrient patterns have been linked to health outcomes related to aging. Food intake is influenced by environmental and genetic factors. The aim of the present study was to compare nutrient patterns across two elderly populations sharing a common ancestral cultural background, but living in different environments. The diet quality, lifestyle and socioeconomic characteristics of participants from the Three-City Study (3C, France, n = 1712) and the Québec Longitudinal Study on Nutrition and Successful Aging (NuAge, Quebec, Canada, n = 1596) were analyzed. Nutrient patterns and their food sources were identified in the two samples using principal component analysis. Diet quality was compared across sample-specific patterns by describing weekly food intake and associations with the Canadian Healthy Eating Index (C-HEI). Three nutrient patterns were retained in each study: a healthy, a Western and a more traditional pattern. These patterns accounted for 50.1% and 53.5% of the total variance in 3C and NuAge, respectively. Higher education and non-physical occupations over lifetime were associated with healthy patterns in both studies. Other characteristics such as living alone, having a body mass index lower than 25 and being an ex-smoker were associated with the healthy pattern in NuAge. No association between these characteristics and the nutrient patterns was noted in 3C. The healthy and Western patterns from each sample also showed an inverse association with C-HEI. The two healthy patterns showed important similarities: adequate food variety, consumption of healthy foods and associations with common sociodemographic factors. This work highlights that nutrient patterns derived using a posteriori methods may be useful to compare the nutritional quality of the diet of distinct populations.

  9. Seasonal Variation and Sources of Dissolved Nutrients in the Yellow River, China

    Directory of Open Access Journals (Sweden)

    Yao Gong

    2015-08-01

    Full Text Available The rapid growth of the economy in China has caused dramatic growth in the industrial and agricultural development in the Yellow River (YR watershed. The hydrology of the YR has changed dramatically due to the climate changes and water management practices, which have resulted in a great variation in the fluxes of riverine nutrients carried by the YR. To study these changes dissolved nutrients in the YR were measured monthly at Lijin station in the downstream region of the YR from 2002 to 2004. This study provides detailed information on the nutrient status for the relevant studies in the lower YR and the Bohai Sea. The YR was enriched in nitrate (average 314 μmol·L−1 with a lower concentration of dissolved silicate (average 131 μmol·L−1 and relatively low dissolved phosphate (average 0.35 μmol·L−1. Nutrient concentrations exhibited substantial seasonal and yearly variations. The annual fluxes of dissolved inorganic nitrogen, phosphate, and silicate in 2004 were 5.3, 2.5, and 4.2 times those in 2002, respectively, primarily due to the increase in river discharge. The relative contributions of nutrient inputs to nitrogen in the YR were: wastewater > fertilizer > atmospheric deposition > soil; while to phosphorus were: wastewater > fertilizer > soil > atmospheric deposition. The ratios of N, P and Si suggest that the YR at Lijin is strongly P-limited with respect to potential phytoplankton growth.

  10. From salmon to shad: Shifting sources of marine-derived nutrients in the Columbia River Basin

    Science.gov (United States)

    Haskell, Craig A.

    2018-01-01

    Like Pacific salmon (Oncorhynchus spp.), nonnative American shad (Alosa sapidissima) have the potential to convey large quantities of nutrients between the Pacific Ocean and freshwater spawning areas in the Columbia River Basin (CRB). American shad are now the most numerous anadromous fish in the CRB, yet the magnitude of the resulting nutrient flux owing to the shift from salmon to shad is unknown. Nutrient flux models revealed that American shad conveyed over 15,000 kg of nitrogen (N) and 3,000 kg of phosphorus (P) annually to John Day Reservoir, the largest mainstem reservoir in the lower Columbia River. Shad were net importers of N, with juveniles and postspawners exporting just 31% of the N imported by adults. Shad were usually net importers of P, with juveniles and postspawners exporting 46% of the P imported by adults on average. American shad contributed salmon owing to their smaller size. Given the relatively high background P levels and low retention times in lower Columbia River reservoirs, it is unlikely that shad marine-derived nutrients affect nutrient balances or food web productivity through autotrophic pathways. However, a better understanding of shad spawning aggregations in the CRB is needed.

  11. Life cycle comparison of centralized wastewater treatment and urine source separation with struvite precipitation: Focus on urine nutrient management.

    Science.gov (United States)

    Ishii, Stephanie K L; Boyer, Treavor H

    2015-08-01

    Alternative approaches to wastewater management including urine source separation have the potential to simultaneously improve multiple aspects of wastewater treatment, including reduced use of potable water for waste conveyance and improved contaminant removal, especially nutrients. In order to pursue such radical changes, system-level evaluations of urine source separation in community contexts are required. The focus of this life cycle assessment (LCA) is managing nutrients from urine produced in a residential setting with urine source separation and struvite precipitation, as compared with a centralized wastewater treatment approach. The life cycle impacts evaluated in this study pertain to construction of the urine source separation system and operation of drinking water treatment, decentralized urine treatment, and centralized wastewater treatment. System boundaries include fertilizer offsets resulting from the production of urine based struvite fertilizer. As calculated by the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI), urine source separation with MgO addition for subsequent struvite precipitation with high P recovery (Scenario B) has the smallest environmental cost relative to existing centralized wastewater treatment (Scenario A) and urine source separation with MgO and Na3PO4 addition for subsequent struvite precipitation with concurrent high P and N recovery (Scenario C). Preliminary economic evaluations show that the three urine management scenarios are relatively equal on a monetary basis (<13% difference). The impacts of each urine management scenario are most sensitive to the assumed urine composition, the selected urine storage time, and the assumed electricity required to treat influent urine and toilet water used to convey urine at the centralized wastewater treatment plant. The importance of full nutrient recovery from urine in combination with the substantial chemical inputs required for N recovery

  12. Dietary sources of energy and nutrients in the contemporary diet of Inuit adults: results from the 2007-08 Inuit Health Survey.

    Science.gov (United States)

    Kenny, Tiff-Annie; Hu, Xue Feng; Kuhnlein, Harriet V; Wesche, Sonia D; Chan, Hing Man

    2018-05-01

    To characterize the major components of the contemporary Inuit diet and identify the primary sources of energy and essential nutrients. Dietary data were derived from the 24 h recall collected by the Inuit Health Survey (IHS) from 2007 to 2008. The population proportion method was used to determine the percentage contribution of each group. Unique food items/preparations (ninety-three country foods and 1591 market foods) were classified into eight country food groups and forty-one market food groups. Nutrient composition of each food item was obtained from the Canadian Nutrient File. Thirty-six communities across three Inuit regions of northern Canada. A representative sample (n 2095) of non-pregnant Inuit adults (≥18 years), selected through stratified random sampling. Despite their modest contribution to total energy intake (6·4-19·6 %, by region) country foods represented a major source of protein (23-52 %), Fe (28-54 %), niacin (24-52 %) and vitamins D (up to 73 %), B6 (18-55 %) and B12 (50-82 %). By contrast, the three most popular energy-yielding market foods (i.e. sweetened beverages, added sugar and bread) collectively contributed approximately 20 % of total energy, while contributing minimally to most micronutrients. A notable exception was the contribution of these foods to Ca (13-21 %) and vitamins E (17-35 %) and C (as much as 50 %). Solid fruits were consumed by less than 25 % of participants while vegetables were reported by 38-59 % of respondents. Country foods remain a critical dimension of the contemporary Inuit diet.

  13. The USA Nr Inventory: Dominant Sources and Primary Transport Pathways

    Science.gov (United States)

    Sabo, R. D.; Clark, C.; Sobota, D. J.; Compton, J.; Cooter, E. J.; Schwede, D. B.; Bash, J. O.; Rea, A.; Dobrowolski, J. P.

    2016-12-01

    Efforts to mitigate the deleterious effects of excess reactive nitrogen (Nr) on human health and ecosystem goods and service while ensuring food, biofuel, and fiber availability, is one of the most pressing environmental management challenges of this century. Effective management of Nr requires up to date inventories that quantitatively characterize the sources, transport, and transformation of Nr through the environment. The inherent complexity of the nitrogen cycle, however, through multiple exchange points across air, water, and terrestrial media, renders such inventories difficult to compile and manage. Previous Nr Inventories are for 2002 and 2007, and used data sources that have since been improved. Thus, this recent inventory will substantially advance the methodology across many sectors of the inventory (e.g. deposition and biological fixation in crops and natural systems) and create a recent snapshot that is sorely needed for policy planning and trends analysis. Here we use a simple mass balance approach to estimate the input-output budgets for all United States Geologic Survey Hydrologic Unit Code-8 watersheds. We focus on a recent year (i.e. 2012) to update the Nr Inventory, but apply the analytical approach for multiple years where possible to assess trends through time. We also compare various sector estimates using multiple methodologies. Assembling datasets that account for new Nr inputs into watersheds (e.g., atmospheric NOy deposition, food imports, biologic N fixation) and internal fluxes of recycled Nr (e.g., manure, Nr emmissions/volatilization) provide an unprecedented, data driven computation of N flux. Input-output budgets will offer insight into 1) the dominant sources of Nr in a watershed (e.g., food imports, atmospheric N deposition, or fertilizer), 2) the primary loss pathways for Nr (e.g., crop N harvest, volatilization/emissions), and 3) what watersheds are net sources versus sinks of Nr. These insights will provide needed clarity for

  14. Study on shrimp waste water and vermicompost as a nutrient source for bell peppers

    Science.gov (United States)

    The aquaculture industry generates significant nutrient-rich wastewater that is released into streams and rivers causing environmental concern. The objective of this controlled environment study was to evaluate the effect of waste shrimp water (SW), vermicompost (VC), at rates of 10%, 20%, 40%, and ...

  15. Fertility management and landscape position: farmers' use of nutrient sources in western Niger and possible improvements

    NARCIS (Netherlands)

    Gandah, M.; Brouwer, J.; Duivenbooden, van N.; Hiernaux, P.

    2003-01-01

    Poor millet growth and yields in Niger are commonly attributed to rainfall deficits and low soil nutrient content. Land management by local farmers is done as a function of soil types, crops, and available resources. Farmer management practices in millet fields located on four different landscape

  16. Geographic, environmental and biotic sources of variation in the nutrient relations of tropical montane forests

    Science.gov (United States)

    James W. Dalling; Katherine Heineman; Grizelle Gonzalez; Rebecca Ostertag

    2016-01-01

    Tropicalmontane forests (TMF) are associated with a widely observed suite of characteristics encompassing forest structure, plant traits and biogeochemistry.With respect to nutrient relations, montane forests are characterized by slow decomposition of organic matter, high investment in below-ground biomass and poor litter quality, relative to tropical lowland forests....

  17. Growth of mono- and mixed cultures of Nannochloropsis salina and Phaeodactylum tricornutum on struvite as a nutrient source

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Ryan W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Siccardi, Anthony J. [Texas AgriLife Research Mariculture Lab., Corpus Christi, TX (United States); Huysman, Nathan D. [Texas AgriLife Research Mariculture Lab., Corpus Christi, TX (United States); Wyatt, Nicholas B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hewson, John C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lane, Todd W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2015-09-26

    In this paper, the suitability of crude and purified struvite (MgNH4PO4), a major precipitate in wastewater streams, was investigated for renewable replacement of conventional nitrogen and phosphate resources for cultivation of microalgae. Bovine effluent wastewater stone, the source of crude struvite, was characterized for soluble N/P, trace metals, and biochemical components and compared to the purified mineral. Cultivation trials using struvite as a major nutrient source were conducted using two microalgae production strains, Nannochloropsis salina and Phaeodactylum tricornutum, in both lab and outdoor pilot-scale raceways in a variety of seasonal conditions. Both crude and purified struvite-based media were found to result in biomass productivities at least as high as established media formulations (maximum outdoor co-culture yield ~20 ± 4 g AFDW/m2/day). Finally, analysis of nutrient uptake by the alga suggest that struvite provides increased nutrient utilization efficiency, and that crude struvite satisfies the trace metals requirement and results in increased pigment productivity for both microalgae strains.

  18. Fusarium spp. is able to grow and invade healthy human nails as a single source of nutrients.

    Science.gov (United States)

    Galletti, J; Negri, M; Grassi, F L; Kioshima-Cotica, É S; Svidzinski, T I E

    2015-09-01

    Onychomycosis caused by Fusarium spp. is emerging, but some factors associated with its development remain unclear, such as whether this genus is keratinolytic. The main aim of the present study was to evaluate the ability of Fusarium to use the human nail as a single source of nutrients. We also performed an epidemiological study and antifungal susceptibility testing of Fusarium spp. that were isolated from patients with onychomycosis. The epidemiological study showed that Fusarium species accounted for 12.4 % of onychomycosis cases, and it was the most common among nondermatophyte molds. The most frequent species identified were F. oxysporum (36.5 %), F. solani (31.8 %), and F. subglutinans (8.3 %). Fluconazole was not active against Fusarium spp., and the response to terbinafine varied according to species. Fusarium was able to grow in vitro without the addition of nutrients and invade healthy nails. Thus, we found that Fusarium uses keratin as a single source of nutrients, and the model proposed herein may be useful for future studies on the pathogenesis of onychomycosis.

  19. The Effects of Different External Carbon Sources on Nitrous Oxide Emissions during Denitrification in Biological Nutrient Removal Processes

    Science.gov (United States)

    Hu, Xiang; Zhang, Jing; Hou, Hongxun

    2018-01-01

    The aim of this study was to investigate the effects of two different external carbon sources (acetate and ethanol) on the nitrous oxide (N2O) emissions during denitrification in biological nutrient removal processes. Results showed that external carbon source significantly influenced N2O emissions during the denitrification process. When acetate served as the external carbon source, 0.49 mg N/L and 0.85 mg N/L of N2O was produced during the denitrificaiton processes in anoxic and anaerobic/anoxic experiments, giving a ratio of N2O-N production to TN removal of 2.37% and 4.96%, respectively. Compared with acetate, the amount of N2O production is negligible when ethanol used as external carbon addition. This suggested that ethanol is a potential alternative external carbon source for acetate from the point of view of N2O emissions.

  20. Hibiscus sabdariffa L. as a source of nutrients, bioactive compounds and colouring agents.

    Science.gov (United States)

    Jabeur, Inès; Pereira, Eliana; Barros, Lillian; Calhelha, Ricardo C; Soković, Marina; Oliveira, M Beatriz P P; Ferreira, Isabel C F R

    2017-10-01

    The nutritional and bioactive composition of plants have aroused much interest not only among scientists, but also in people's daily lives. Apart from the health benefits, plants are a source of pigments that can be used as natural food colorants. In this work, the nutritional composition of Hibiscus sabdariffa L. was analysed, as well as its bioactive compounds and natural pigments. Glucose (sugar), malic acid (organic acid), α-tocopherol (tocopherol) and linoleic acid (fatty acid) were the major constituents in the corresponding classes. 5-(Hydroxymethyl) furfural was the most abundant non-anthocyanin compound, while delphinidin-3-O-sambubioside was the major anthocyanin both in its hydroethanolic extract and infusion. H. sabdariffa extracts showed antioxidant and antimicrobial activities, highlighting that the hydroethanol extract presents not only lipid peroxidation inhibition capacity, but also bactericidal/fungicidal inhibition ability for all the bacteria and fungi tested. Furthermore, both extracts revealed the absence of toxicity using porcine primary liver cells. The studied plant species was thus not only interesting for nutritional purposes but also for bioactive and colouring applications in food, cosmetic and pharmaceutical industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Nutrient flux fuels the summer primary productivity in the oligotrophic waters of the Gulf of Aqaba, Red Sea

    Directory of Open Access Journals (Sweden)

    Tariq Al-Najjar

    2005-03-01

    Full Text Available The thermohaline characteristics of the Gulf of Aqaba, Red Sea,depict a well-defined seasonal pattern of winter mixing from December toApril and summer stratification from May to November. This thermohalinestructure is a major controlling factor of the nutrient, chlorophyll aand primary productivity seasonal cycles. The nitrate and chlorophyll aconcentration records generated down to 200 m at a vertical resolution of25 m - weekly during 1994, 1995 and every two weeks from April 1997 throughto December 2000 - are employed to assess the nitrogen flux across the summerthermocline of the Gulf of Aqaba. The flux calculations are based on a simplediffusion model that incorporates the physical stress eddy diffusivity factorKz and a biological stress factor k. Both Kz and k arecalculated using the Michaelis-Menten equation and the nitrate concentrationgradient. The total nitrate flux of the Gulf of Aqaba during the seven summermonths (May-November is estimated at 0.52 mole N m-2. In relation toestablished primary productivity values (75.5 g C m-2 (MayNovember-1 and the generated chlorophyll a records, thisyields an f fraction of new to total primary production of 0.50. Thisrelatively high f value is discussed with respect to the geophysicalcharacteristics of the Gulf of Aqaba and similar oceanic basins. The remaining50% is accounted for by cross-sectional flow from the relativelynutrient-rich coral reef coastal habitat and rapid recycling, triggered byhigh irradiance and water temperature.

  2. Nutrients and primary production in a shallow stratified ecosystem in the Iroise Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Birrien, J; Wafar, M.V.M.; LeCorre, P.; Riso, R.

    stream_size 22 stream_content_type text/plain stream_name J_Plankton_Res_13_721.pdf.txt stream_source_info J_Plankton_Res_13_721.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  3. Physiological ecology of SRS Carolina bay phytoplankton communities: Effects of nutrient changes and CO2 sources

    International Nuclear Information System (INIS)

    Williams, J.B.

    1992-11-01

    Impacts of land-use activities on wetland ecosystems are important issues for environmental planners, conservation groups, and government agencies. The progress report of this project at DOE's Savannah River Site focused on two specific objectives: determination of the effects of nutrient enrichment (fertilizing during wetlands restoration) on phytoplankton communities and comparison of phytoplankton community dynamics during the current extended hydroperiod for Carolina Bays with patterns in previous drier years

  4. Characterization of biochars from different sources and evaluation of release of nutrients and contaminants

    Directory of Open Access Journals (Sweden)

    Natália Aragão de Figueredo

    Full Text Available ABSTRACT The biochar, product of pyrolysis of organic waste, has been used as a soil conditioner and alternative on solid waste management. However, the raw material and pyrolysis temperature used influence the quantity and dynamics of release of nutrients and contaminants from the biochar. The objective was to evaluate the use of waste sugarcane bagasse, eucalyptus and sewage sludge for production of biochar and determine the chemical, physical, mineralogical properties and acid extraction of these materials produced at 350 °C and 500 °C. Were evaluated the proportion of C, H, N, O; ashes; macro and micronutrients, plus some contaminants; characterization of mineral phases by diffractometry of X- rays; functional groups by infrared absorption spectroscopy (FTIR. Moreover, it was determined the release of nutrients and contaminants for the extraction in increasing concentration of HNO3 (0,01 - 2,0 mol L-1. The O/C and H/C relations decreased with increasing temperature of pyrolysis, which define a greater stability of the C of biochars. Sewage sludge biochar (BC-L had the highest nutrient release rates and contaminant metals (Cd, Cr, Ni and Pb. Acid extraction of other biochars was very low (<20% of the total content. The results indicate that the carbon fraction of biochar contributes to the low rate of release of the elements in acid place.

  5. The potential use of treated brewery effluent as a water and nutrient source in irrigated crop production

    Directory of Open Access Journals (Sweden)

    Richard P. Taylor

    2018-06-01

    Full Text Available Brewery effluent (BE needs to be treated before it can be released into the environment, reused or used in down-stream activities. This study demonstrated that anaerobic digestion (AD followed by treatment in an integrated tertiary effluent treatment system transformed BE into a suitable solution for crop irrigation. Brewery effluent can be used to improve crop yields: Cabbage (Brassica oleracea cv. Star 3301, grew significantly larger when irrigated with post-AD, post-primary-facultative-pond (PFP effluent, compared with those irrigated with post-constructed-wetland (CW effluent or tap water only (p < 0.0001. However, cabbage yield when grown using BE was 13% lower than that irrigated with a nutrient-solution and fresh water; the electrical conductivity of BE (3019.05 ± 48.72 µs/cm2 may have been responsible for this. Post-CW and post-high-rate-algal-pond (HRAP BE was least suitable due to their higher conductivity and lower nutrient concentration. After three months, soils irrigated with post-AD and post-PFP BE had a significantly higher sodium concentration and sodium adsorption ratio (3919 ± 94.77 & 8.18 ± 0.17 mg/kg than soil irrigated with a commercial nutrient-solution (920.58 ± 27.46 & 2.20 ± 0.05 mg/kg. However, this was not accompanied by a deterioration in the soil's hydro-physical properties, nor a change in the metabolic community structure of the soil. The benefits of developing this nutrient and water resource could contribute to cost-reductions at the brewery, more efficient water, nutrient and energy management, and job creation. Future studies should investigate methods to reduce the build-up of salt in the soil when treated BE is used to irrigate crops. Keywords: Wastewater irrigation, Nutrient recovery, Agriculture, Brewery effluent

  6. The potential contribution of yellow cassava to dietary nutrient adequacy of primary-school children in Eastern Kenya; the use of linear programming.

    Science.gov (United States)

    Talsma, Elise F; Borgonjen-van den Berg, Karin J; Melse-Boonstra, Alida; Mayer, Eva V; Verhoef, Hans; Demir, Ayşe Y; Ferguson, Elaine L; Kok, Frans J; Brouwer, Inge D

    2018-02-01

    Introduction of biofortified cassava as school lunch can increase vitamin A intake, but may increase risk of other deficiencies due to poor nutrient profile of cassava. We assessed the potential effect of introducing a yellow cassava-based school lunch combined with additional food-based recommendations (FBR) on vitamin A and overall nutrient adequacy using Optifood (linear programming tool). Cross-sectional study to assess dietary intakes (24 h recall) and derive model parameters (list of foods consumed, median serving sizes, food and food (sub)group frequency distributions, food cost). Three scenarios were modelled, namely daily diet including: (i) no school lunch; (ii) standard 5d school lunch with maize/beans; and (iii) 5d school lunch with yellow cassava. Each scenario and scenario 3 with additional FBR were assessed on overall nutrient adequacy using recommended nutrient intakes (RNI). Eastern Kenya. Primary-school children (n 150) aged 7-9 years. Best food pattern of yellow cassava-based lunch scenario achieved 100 % RNI for six nutrients compared with no lunch (three nutrients) or standard lunch (five nutrients) scenario. FBR with yellow cassava and including small dried fish improved nutrient adequacy, but could not ensure adequate intake of fat (52 % of average requirement), riboflavin (50 % RNI), folate (59 % RNI) and vitamin A (49 % RNI). Introduction of yellow cassava-based school lunch complemented with FBR potentially improved vitamin A adequacy, but alternative interventions are needed to ensure dietary adequacy. Optifood is useful to assess potential contribution of a biofortified crop to nutrient adequacy and to develop additional FBR to address remaining nutrient gaps.

  7. Food sources of energy and nutrients in Finnish girls and boys 6–8 years of age – the PANIC study

    Directory of Open Access Journals (Sweden)

    Aino-Maija Eloranta

    2016-09-01

    Full Text Available Background: Data on food sources of nutrients are needed to improve strategies to enhance nutrient intake among girls and boys in Western countries. Objective: To identify major food sources of energy, energy nutrients, dietary fibre, and micronutrients, and to study gender differences in these food sources among children. Design: We assessed food consumption and nutrient intake using 4-day food records in a population sample of Finnish girls (n=213 and boys (n=217 aged 6–8 years from the Physical Activity and Nutrition in Children Study. We calculated the percentual contribution of 55 food groups for energy and nutrient intake using the population proportion method. Results: Low-fibre grain products, skimmed milk, and high-fibre bread provided almost 23% of total energy intake. Skimmed milk was the top source of protein (18% of total intake, vitamin D (32%, potassium (20%, calcium (39%, magnesium (17%, and zinc (16%. Vegetable oils (15% and high-fat vegetable oil–based spreads (14% were the top sources of polyunsaturated fat. High-fibre bread was the top source of fibre (27% and iron (12%. Non-root vegetables were the top source of folate (14% and vitamin C (22%. Sugar-sweetened beverages provided 21% of sucrose intake. Pork was a more important source of protein and sausage was a more important source of total fat and monounsaturated fat in boys than in girls. Vegetable oils provided a higher proportion of unsaturated fat and vitamin E among boys, whereas high-fat vegetable oil–based spreads provided a higher proportion of these nutrients among girls. Conclusion: Commonly recommended foods, such as skimmed milk, high-fibre grain products, vegetables, vegetable oil, and vegetable oil–based spreads, were important sources of several nutrients, whereas sugar-sweetened beverages provided the majority of sucrose intake among children. This knowledge can be used in improving health among children by dietary interventions, nutrition education

  8. Food sources of energy and nutrients in Finnish girls and boys 6–8 years of age – the PANIC study

    Science.gov (United States)

    Eloranta, Aino-Maija; Venäläinen, Taisa; Soininen, Sonja; Jalkanen, Henna; Kiiskinen, Sanna; Schwab, Ursula; Lakka, Timo A.; Lindi, Virpi

    2016-01-01

    Background Data on food sources of nutrients are needed to improve strategies to enhance nutrient intake among girls and boys in Western countries. Objective To identify major food sources of energy, energy nutrients, dietary fibre, and micronutrients, and to study gender differences in these food sources among children. Design We assessed food consumption and nutrient intake using 4-day food records in a population sample of Finnish girls (n=213) and boys (n=217) aged 6–8 years from the Physical Activity and Nutrition in Children Study. We calculated the percentual contribution of 55 food groups for energy and nutrient intake using the population proportion method. Results Low-fibre grain products, skimmed milk, and high-fibre bread provided almost 23% of total energy intake. Skimmed milk was the top source of protein (18% of total intake), vitamin D (32%), potassium (20%), calcium (39%), magnesium (17%), and zinc (16%). Vegetable oils (15%) and high-fat vegetable oil–based spreads (14%) were the top sources of polyunsaturated fat. High-fibre bread was the top source of fibre (27%) and iron (12%). Non-root vegetables were the top source of folate (14%) and vitamin C (22%). Sugar-sweetened beverages provided 21% of sucrose intake. Pork was a more important source of protein and sausage was a more important source of total fat and monounsaturated fat in boys than in girls. Vegetable oils provided a higher proportion of unsaturated fat and vitamin E among boys, whereas high-fat vegetable oil–based spreads provided a higher proportion of these nutrients among girls. Conclusion Commonly recommended foods, such as skimmed milk, high-fibre grain products, vegetables, vegetable oil, and vegetable oil–based spreads, were important sources of several nutrients, whereas sugar-sweetened beverages provided the majority of sucrose intake among children. This knowledge can be used in improving health among children by dietary interventions, nutrition education, and

  9. Growth characteristics and nutrient removal capability of eco-ditch plants in mesocosm sediment receiving primary domestic wastewater.

    Science.gov (United States)

    Kumwimba, Mathieu Nsenga; Zhu, Bo; Muyembe, Diana Kavidia; Dzakpasu, Mawuli

    2017-10-01

    Eco-ditches are being explored to maximize their capability of capturing pollutants and mitigate any harmful side effects in rivers. In this study, mesocosm plastic drum sediment and field experiments were set up to screen 18 plant species found in ditches and identify those with potential for high biomass production and nutrients removal. Terrestrial plants grown in the mesocosm system were shown to be able to acclimate to aquatic conditions and to survive in primary domestic sewage. About 73-95% increase in plant biomass was recorded. Removal efficiencies for total nitrogen, total phosphorus, and ammonium-nitrogen from the sewage of 72-99%, 64-99%, and 75-100%, respectively, were recorded. Furthermore, complete removal of the applied nitrate-nitrogen load was achieved in mesocosm systems. Findings also show that all species, but especially Acorus calamus, Canna indica, Canna lily, Cyperus alternifolius, Colocasia gigantea, Eichhornia crassipes, Iris sibirica, and Typha latifolia had the highest efficiencies for nitrogen and phosphorous removal. The N and P mass balance analysis demonstrated that plant uptake and sediment N and P accumulation accounted for 41-86% and 18-49% of the total influent TN and TP loads, respectively. In addition, the amounts of nitrogen and phosphorous uptake by these plant species were influenced significantly by biomass. The field-culture experiment further identified Canna indica followed by Cyperus alternifolius as the most promising for high biomass production and nutrients uptake. Therefore, these plants may be recommended for extensive use in treating highly eutrophicated rivers. Outcomes of this work can be useful for model design specifications in eco-ditch mitigation of sewage pollution.

  10. Sediment and Nutrient Contributions from Subsurface Drains and Point Sources to an Agricultural Watershed

    Directory of Open Access Journals (Sweden)

    Bonnie Ball Coelho

    2010-03-01

    Full Text Available Excess sediment and nutrients in surface waters can threaten aquatic life. To determine the relative importance of subsurface drainage as a pathway for movement of sediment and nutrients to surface waters, loading from various tile systems was compared to that from sewage treatment plants (STP within the same watershed. Movement through tiles comprised 1 to 8% of estimated total (overland plus tile annual sediment loading from the respective areas drained by the tile. Load during the growing season from five closed drain- age systems without surface inlets averaged 5 kg sediment/ha, 0.005 kg dissolved reactive P (DRP/ha, 0.003 kg NH4-N/ha, and 3.8 kg NO3-N/ha; and from two open drainage systems with surface inlets averaged 14 kg sediment/ha, 0.03 kg DRP/ha, 0.04 kg NH4-N/ha, and 3.1 kg NO3-N/ha. The eight STP contributed about 44 530 kg suspended sediments, 3380 kg total P, 1340 kg NH4-N, and 116 900 kg NO3-N to the watershed annually. Drainage systems added less NH4-N and P, but more NO3-N and suspended solids to surface waters than STP. Tile drainage pathways for NO3-N, STP in the case of P, and overland pathways for sediment are indicated as targets to control loading in artificially drained agricultural watersheds.

  11. Determination of the Effects of Nutrient sources on Enhancement of Crop Tolerance to Bean Root Rot and Bean Stem Maggot in Western Kenya

    International Nuclear Information System (INIS)

    Otsyula, R.M.; Nderitu, J.H.

    1999-01-01

    Field bean phaseolus vulgaris tolerance to root rot (BRR) and bean stem maggot (BSM) is enhanced by improvement of soil nutrients. Organic and inorganic sources of soil nutrients were evaluated in this study to determine their effects on crop tolerance to BRR and BSM. Three variety of GLP 585 susceptible to BRR and BSM; GLP X92 tolerant to BRR and BSM; and KK-8 resistant to BRR and BSM were used. The study was conducted in farmer's field with high level of BRR and BSM over three seasons in a split plot design. Nutrient sources were laid down in main plots while varieties were in subplots. KK-8 gave the highest plant survival and yield over the seasons. GLP 585 had the lowest mean yield and plant survival. Crop tolerance was greatly improved by application of DAP as applied as nutrient sources and varieties for crop tolerance were identified

  12. Daily consumption of foods and nutrients from institutional and home sources among young children attending two contrasting day-care centers in Guatemala City.

    Science.gov (United States)

    Vossenaar, M; Jaramillo, P M; Soto-Méndez, M-J; Panday, B; Hamelinck, V; Bermúdez, O I; Doak, C M; Mathias, P; Solomons, N W

    2012-12-01

    Adequate nutrition is critical to child development and institutions such as day-care centers could potentially complement children's diets to achieve optimal daily intakes. The aim of the study was to describe the full-day diet of children, examining and contrasting the relative contribution of home-derived versus institutional energy and nutrient sources. The present comparison should be considered in the domain of a case-study format. The diets of 33, 3-6 y old children attending low-income day-care centers serving either 3 or a single meal were examined. The home-diet was assessed by means of 3 non-consecutive 24-hr recalls. Estimated energy and nutrient intakes at the centers and at home were assessed and related to Recommended Nutrient Intakes (RNI). Nutrient densities, critical densities and main sources of nutrients were computed. We observed that in children attending the day-care center serving three meals, home-foods contributed less than half the daily energy (47.7%) and between 29.9% and 53.5% of daily nutrients. In children receiving only lunch outside the home, energy contribution from the home was 83.9% and 304 kcal lower than for children receiving 3 meals. Furthermore, between 59.0% and 94.8% of daily nutrients were provided at home. Daily energy, nutrient intakes and nutrient densities were well above the nutrient requirements for this age group, and particularly high for vitamin A. The overall dietary variety was superior in the situation of greater contribution of home fare, but overall the nutrient density and adequacy of the aggregate intakes did not differ in any important manner.

  13. Potential of thin stillage as a low-cost nutrient source for direct cellulose fermentation by Clostridium thermocellum

    Directory of Open Access Journals (Sweden)

    Rumana Islam

    2015-11-01

    Full Text Available Utilization of thin stillage (TS, derived from grain-based ethanol production, was investigated as an alternative source for microbial growth nutrients during direct conversion of cellulose by Clostridium thermocellum DSM 1237. Fermentation end-products synthesized by C. thermocellum grown on media prepared with various concentrations (50-400 g/L of TS were compared to those synthesized by C. thermocellum grown on reagent grade chemical (reference medium. Cell-growth in TS media, monitored with the aid of quantitative polymerase chain reactions (qPCR technique, showed prolonged growth with increasing TS concentration. Final fermentation end-product concentrations from TS media were comparable with those from the reference medium despite lower growth-rates. The volumetric H2 production generated by C. thermocellum grown with medium containing a low concentration (50 g/L of TS matched the volumetric H2 production by C. thermocellum grown in the reference medium, while higher concentrations (200 g/L of TS resulted in greater synthesis of ethanol. Supplementation of TS-media with Mg++ enhanced ethanol production, while hydrogen production remained unchanged. These results suggest that TS, an attractive source of low-cost nutrients, is capable of supporting the growth of C. thermocellum and that high concentrations of TS favor synthesis of ethanol over hydrogen from cellulose.

  14. Biological nitrogen (N) fixation - The source of N nutrient to increase yield

    International Nuclear Information System (INIS)

    Heiling, M.; Hardarson, G.

    2006-01-01

    Nitrogen is an essential plant nutrient. It is the nutrient that is most commonly deficient, contributing to reduced agricultural yields throughout the world. Developing countries used more than 85 million metric tones of nitrogenous fertilizer in 2003, worth billions of US dollars. Such fertilizer expenditure can be significantly reduced by incorporating biological nitrogen fixed leguminous crops into a growing rotation. In leguminous crops, a symbiotic relationship between a bacterium called Rhizobium and legumes can provide large amounts of nitrogen to the plant and subsequently to soils where they are grown. In this process the bacteria form nodules on the root system and convert the nitrogen coming from air into molecules that can be absorbed by the plants. Beside their fertilizing properties, legumes are rich in protein and constitute a very important role in the human and animal nutrition. In the Soil Science Unit (SSU) of the FAO/IAEA Agriculture and Biotechnology Laboratory fellows from all over the world receive training in the use of 15 N stable isotope techniques to optimise the nitrogen fixation. Several parameters such as the placement of the nodules on the legume root system, the amount of soil mineral nitrogen and phosphorus fertilizer applied and the temperature have an impact on the amount of nitrogen fixed by the plant. It is therefore important to identify relative importance of these parameters on biological N fixation. The 15 N isotope dilution method is an appropriate technique to test the biological nitrogen fixation in the laboratory first. This useful knowledge can then be communicated to the farmers and can be tested under field conditions

  15. Conversion of tropical lowland forest reduces nutrient return through litterfall, and alters nutrient use efficiency and seasonality of net primary production.

    Science.gov (United States)

    Kotowska, Martyna M; Leuschner, Christoph; Triadiati, Triadiati; Hertel, Dietrich

    2016-02-01

    Tropical landscapes are not only rapidly transformed by ongoing land-use change, but are additionally confronted by increasing seasonal climate variation. There is an increasing demand for studies analyzing the effects and feedbacks on ecosystem functioning of large-scale conversions of tropical natural forest into intensively managed cash crop agriculture. We analyzed the seasonality of aboveground litterfall, fine root litter production, and aboveground woody biomass production (ANPP(woody)) in natural lowland forests, rubber agroforests under natural tree cover ("jungle rubber"), rubber and oil palm monocultures along a forest-to-agriculture transformation gradient in Sumatra. We hypothesized that the temporal fluctuation of litter production increases with increasing land-use intensity, while the associated nutrient fluxes and nutrient use efficiency (NUE) decrease. Indeed, the seasonal variation of aboveground litter production and ANPP(woody) increased from the natural forest to the plantations, while aboveground litterfall generally decreased. Nutrient return through aboveground litter was mostly highest in the natural forest; however, it was significantly lower only in rubber plantations. NUE of N, P and K was lowest in the oil palm plantations, with natural forest and the rubber systems showing comparably high values. Root litter production was generally lower than leaf litter production in all systems, while the root-to-leaf ratio of litter C flux increased along the land-use intensity gradient. Our results suggest that nutrient and C cycles are more directly affected by climate seasonality in species-poor agricultural systems than in species-rich forests, and therefore might be more susceptible to inter-annual climate fluctuation and climate change.

  16. Atmospheric deposition as a source of carbon and nutrients to an alpine catchment of the Colorado Rocky Mountains

    Science.gov (United States)

    Mladenov, N.; Williams, M. W.; Schmidt, S. K.; Cawley, K.

    2012-08-01

    Many alpine areas are experiencing deglaciation, biogeochemical changes driven by temperature rise, and changes in atmospheric deposition. There is mounting evidence that the water quality of alpine streams may be related to these changes, including rising atmospheric deposition of carbon (C) and nutrients. Given that barren alpine soils can be severely C limited, atmospheric deposition sources may be an important source of C and nutrients for these environments. We evaluated the magnitude of atmospheric deposition of C and nutrients to an alpine site, the Green Lake 4 catchment in the Colorado Rocky Mountains. Using a long-term dataset (2002-2010) of weekly atmospheric wet deposition and snowpack chemistry, we found that volume weighted mean dissolved organic carbon (DOC) concentrations were 1.12 ± 0.19 mg l-1, and weekly concentrations reached peaks as high at 6-10 mg l-1 every summer. Total dissolved nitrogen concentration also peaked in the summer, whereas total dissolved phosphorus and calcium concentrations were highest in the spring. To investigate potential sources of C in atmospheric deposition, we evaluated the chemical quality of dissolved organic matter (DOM) and relationships between DOM and other solutes in wet deposition. Relationships between DOC concentration, fluorescence, and nitrate and sulfate concentrations suggest that pollutants from nearby urban and agricultural sources and organic aerosols derived from sub-alpine vegetation may influence high summer DOC wet deposition concentrations. Interestingly, high DOC concentrations were also recorded during "dust-in-snow" events in the spring, which may reflect an association of DOM with dust. Detailed chemical and spectroscopic analyses conducted for samples collected in 2010 revealed that the DOM in many late spring and summer samples was less aromatic and polydisperse and of lower molecular weight than that of winter and fall samples. Our C budget estimates for the Green Lake 4 catchment

  17. Models for transport and fate of carbon, nutrients and point source released radionuclides to an aquatic ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Kumblad, Linda [Stockholm Univ. (Sweden). Dept. of Systems Ecology; Kautsky, Ulrik [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2004-09-01

    In this report three ecosystem models are described in terms of structure, initial data, and results. All models are dynamic, mass-balanced and describe the transport and fate of elements in an open aquatic ecosystem. The models are based on ecologically sound principles, provide model results with high resolution and transparency, and are constrained by the nutrient dynamics of the ecosystem itself. The processes driving the transport in all the models are both the biological processes such as primary production, consumption, respiration and excretion, and abiotic e.g. water exchange and air-sea exchange. The first model, the CNP-model, describes the distribution and fluxes of carbon and nutrients for the coastal ecosystem off Forsmark. The second model, the C-14 model, is an extension of the CNP-model and describes the transport and distribution of hypothetically released C-14 from the underground repository SFR-1 to the ecosystem above. The third model, the RN-model, is a generic radionuclide flow model that models the transport and distribution of radionuclides other than C-14 hypothetically discharged to the ecosystem. The model also analyses the importance of some radionuclide specific mechanisms for the radionuclide flow. The generic radionuclide model is also based on the CNP-model, but has radionuclide specific mechanisms connected to each compartment.

  18. Models for transport and fate of carbon, nutrients and point source released radionuclides to an aquatic ecosystem

    International Nuclear Information System (INIS)

    Kumblad, Linda

    2004-09-01

    In this report three ecosystem models are described in terms of structure, initial data, and results. All models are dynamic, mass-balanced and describe the transport and fate of elements in an open aquatic ecosystem. The models are based on ecologically sound principles, provide model results with high resolution and transparency, and are constrained by the nutrient dynamics of the ecosystem itself. The processes driving the transport in all the models are both the biological processes such as primary production, consumption, respiration and excretion, and abiotic e.g. water exchange and air-sea exchange. The first model, the CNP-model, describes the distribution and fluxes of carbon and nutrients for the coastal ecosystem off Forsmark. The second model, the C-14 model, is an extension of the CNP-model and describes the transport and distribution of hypothetically released C-14 from the underground repository SFR-1 to the ecosystem above. The third model, the RN-model, is a generic radionuclide flow model that models the transport and distribution of radionuclides other than C-14 hypothetically discharged to the ecosystem. The model also analyses the importance of some radionuclide specific mechanisms for the radionuclide flow. The generic radionuclide model is also based on the CNP-model, but has radionuclide specific mechanisms connected to each compartment

  19. Spatial Patterns and Temperature Predictions of Tuna Fatty Acids: Tracing Essential Nutrients and Changes in Primary Producers.

    Directory of Open Access Journals (Sweden)

    Heidi R Pethybridge

    Full Text Available Fatty acids are among the least understood nutrients in marine environments, despite their profile as key energy components of food webs and that they are essential to all life forms. Presented here is a novel approach to predict the spatial-temporal distributions of fatty acids in marine resources using generalized additive mixed models. Fatty acid tracers (FAT of key primary producers, nutritional condition indices and concentrations of two essential long-chain (≥C20 omega-3 fatty acids (EFA measured in muscle of albacore tuna, Thunnus alalunga, sampled in the south-west Pacific Ocean were response variables. Predictive variables were: location, time, sea surface temperature (SST and chlorophyll-a (Chla, and phytoplankton biomass at time of catch and curved fork length. The best model fit for all fatty acid parameters included fish length and SST. The first oceanographic contour maps of EFA and FAT (FATscapes were produced and demonstrated clear geographical gradients in the study region. Predicted changes in all fatty acid parameters reflected shifts in the size-structure of dominant primary producers. Model projections show that the supply and availability of EFA are likely to be negatively affected by increases in SST especially in temperate waters where a 12% reduction in both total fatty acid content and EFA proportions are predicted. Such changes will have large implications for the availability of energy and associated health benefits to high-order consumers. Results convey new concerns on impacts of projected climate change on fish-derived EFA in marine systems.

  20. Nutrients and clam contamination by Escherichia coli in a meso-tidal coastal lagoon: Seasonal variation in counter cycle to external sources

    International Nuclear Information System (INIS)

    Botelho, Maria João; Soares, Florbela; Matias, Domitília; Vale, Carlos

    2015-01-01

    Highlights: • Sources of nutrients and E. coli in Ria Formosa linked to tourism in summer. • Lower nutrient values and clam contamination by E. coli in summer. • Bactericide effect of temperature and solar radiation causes lower E. coli. • Higher biological consumption of nutrients in warmer periods. • Results mirror possible effects of climate changes on coastal lagoons. - Abstract: The clam Ruditapes decussatus was transplanted from a natural recruitment area of Ria Formosa to three sites, surveyed for nutrients in water and sediments. Specimens were sampled monthly for determination of Escherichia coli, condition index and gonadal index. Higher nutrient values in low tide reflect drainage, anthropogenic sources or sediment regeneration, emphasising the importance of water mixing in the entire lagoon driven by the tide. Despite the increase of effluent discharges in summer due to tourism, nutrient concentrations and E. coli in clams were lower in warmer periods. The bactericide effect of temperature and solar radiation was better defined in clams from the inlet channel site than from sites closer to urban effluents. High temperature in summer and torrential freshwater inputs to Ria Formosa may anticipate climate change scenarios for south Europe. Seasonal variation of nutrients and clam contamination may thus point to possible alterations in coastal lagoons and their ecosystem services

  1. Municipal Compost as a Nutrient Source for Organic Crop Production in New Zealand

    Directory of Open Access Journals (Sweden)

    Abie Horrocks

    2016-05-01

    Full Text Available About 1% of New Zealand farmland is managed organically. Nitrogen is the nutrient most likely to limit organic crop production. A potential solution is incorporation of compost to supply N. About 726,000 t of municipal garden and kitchen wastes are sent to landfills annually. Composting offers a means of reducing the impact of landfill wastes on the wider environment. Organically certified compost (N content typically 2% to 2.5% is available from some municipal composting plants. To be effectively used on organic farms, the rate of N release (mineralization must be known. Laboratory incubations were conducted to quantify mineralization of compost N under controlled (temperature and moisture conditions. Nitrogen availability and crop yields from a one-off application of compost (25–100 t·ha−1 were also assessed in two field trials (using cereal and forage crops. The results suggested that a relatively small part (13%–23% of compost N was used by the crops in 3–4 years. Much of this was mineral N present at the time of application. Mineralization rates in the laboratory and field studies were much lower than expected from published work or compost C:N ratio (considered an important indicator of N mineralization potential of composts.

  2. Primary carbon sources for juvenile penaeid shrimps in a mangrove ...

    African Journals Online (AJOL)

    Carbon and nitrogen stable isotope ratios were determined in a variety of primary producers (mangroves, epiphytes, phytoplankton and seagrasses), sediments and in five penaeid shrimp species (Penaeus (Fenneropenaeus) indicus, P. japonicus, P. semisulcatus, Metapenaeus monoceros and M. stebbingi), collected ...

  3. The World of Barilla Taylor: Bringing History to Life through Primary Sources.

    Science.gov (United States)

    Stearns, Liza

    1997-01-01

    Presents a lesson plan using material from a primary source-based curriculum kit titled "The World of Barilla Taylor." The kit uses personal letters, maps, hospital and work records, and other primary sources to document the life of a young woman working in the textile mills in 19th-century Massachusetts. (MJP)

  4. The Challenges of Primary Sources, Collaboration, and the K-16 Elizabeth Murray Project

    Science.gov (United States)

    Cleary, Patricia; Neumann, David

    2009-01-01

    In recent years, the use of primary sources in the history and social studies classroom has been increasingly promoted as a necessary and welcome practice, one designed to improve the quality of history education and to encourage student interest and engagement. Although some K-12 educators have been wary of adopting the use of primary sources,…

  5. Particle water and pH in the Eastern Mediterranean: sources variability and implications for nutrients availability

    Science.gov (United States)

    Nikolaou, P.; Bougiatioti, A.; Stavroulas, I.; Kouvarakis, G.; Nenes, A.; Weber, R.; Kanakidou, M.; Mihalopoulos, N.

    2015-10-01

    Particle water (LWC) and aerosol pH drive the aerosol phase, heterogeneous chemistry and bioavailability of nutrients that profoundly impact cloud formation, atmospheric composition and atmospheric fluxes of nutrients to ecosystems. Few measurements of in-situ LWC and pH however exist in the published literature. Using concurrent measurements of aerosol chemical composition, cloud condensation nuclei activity and tandem light scattering coefficients, the particle water mass concentrations associated with the aerosol inorganic (Winorg) and organic (Worg) components are determined for measurements conducted at the Finokalia atmospheric observation station in the eastern Mediterranean between August and November 2012. These data are interpreted using the ISORROPIA-II thermodynamic model to predict pH of aerosols originating from the various sources that influence air quality in the region. On average, closure between predicted aerosol water and that determined by comparison of ambient with dry light scattering coefficients was achieved to within 8 % (slope = 0.92, R2 = 0.8, n = 5201 points). Based on the scattering measurements a parameterization is also derived, capable of reproducing the hygroscopic growth factor (f(RH)) within 15 % of the measured values. The highest aerosol water concentrations are observed during nighttime, when relative humidity is highest and the collapse of the boundary layer increases the aerosol concentration. A significant diurnal variability is found for Worg with morning and afternoon average mass concentrations being 10-15 times lower than nighttime concentrations, thus rendering Winorg the main form of particle water during daytime. The average value of total aerosol water was 2.19 ± 1.75 μg m-3, contributing on average up to 33 % of the total submicron mass concentration. Average aerosol water associated with organics, Worg, was equal to 0.56 ± 0.37 μg m-3, thus organics contributed about 27.5 % to the total aerosol water, mostly

  6. Particle water and pH in the eastern Mediterranean: source variability and implications for nutrient availability

    Science.gov (United States)

    Bougiatioti, Aikaterini; Nikolaou, Panayiota; Stavroulas, Iasonas; Kouvarakis, Giorgos; Weber, Rodney; Nenes, Athanasios; Kanakidou, Maria; Mihalopoulos, Nikolaos

    2016-04-01

    Particle water (liquid water content, LWC) and aerosol pH are important parameters of the aerosol phase, affecting heterogeneous chemistry and bioavailability of nutrients that profoundly impact cloud formation, atmospheric composition, and atmospheric fluxes of nutrients to ecosystems. Few measurements of in situ LWC and pH, however, exist in the published literature. Using concurrent measurements of aerosol chemical composition, cloud condensation nuclei activity, and tandem light scattering coefficients, the particle water mass concentrations associated with the aerosol inorganic (Winorg) and organic (Worg) components are determined for measurements conducted at the Finokalia atmospheric observation station in the eastern Mediterranean between June and November 2012. These data are interpreted using the ISORROPIA-II thermodynamic model to predict the pH of aerosols originating from the various sources that influence air quality in the region. On average, closure between predicted aerosol water and that determined by comparison of ambient with dry light scattering coefficients was achieved to within 8 % (slope = 0.92, R2 = 0.8, n = 5201 points). Based on the scattering measurements, a parameterization is also derived, capable of reproducing the hygroscopic growth factor (f(RH)) within 15 % of the measured values. The highest aerosol water concentrations are observed during nighttime, when relative humidity is highest and the collapse of the boundary layer increases the aerosol concentration. A significant diurnal variability is found for Worg with morning and afternoon average mass concentrations being 10-15 times lower than nighttime concentrations, thus rendering Winorg the main form of particle water during daytime. The average value of total aerosol water was 2.19 ± 1.75 µg m-3, contributing on average up to 33 % of the total submicron mass concentration. Average aerosol water associated with organics, Worg, was equal to 0.56 ± 0.37 µg m-3; thus, organics

  7. Particle water and pH in the eastern Mediterranean: source variability and implications for nutrient availability

    Directory of Open Access Journals (Sweden)

    A. Bougiatioti

    2016-04-01

    Full Text Available Particle water (liquid water content, LWC and aerosol pH are important parameters of the aerosol phase, affecting heterogeneous chemistry and bioavailability of nutrients that profoundly impact cloud formation, atmospheric composition, and atmospheric fluxes of nutrients to ecosystems. Few measurements of in situ LWC and pH, however, exist in the published literature. Using concurrent measurements of aerosol chemical composition, cloud condensation nuclei activity, and tandem light scattering coefficients, the particle water mass concentrations associated with the aerosol inorganic (Winorg and organic (Worg components are determined for measurements conducted at the Finokalia atmospheric observation station in the eastern Mediterranean between June and November 2012. These data are interpreted using the ISORROPIA-II thermodynamic model to predict the pH of aerosols originating from the various sources that influence air quality in the region. On average, closure between predicted aerosol water and that determined by comparison of ambient with dry light scattering coefficients was achieved to within 8 % (slope  =  0.92, R2  =  0.8, n  =  5201 points. Based on the scattering measurements, a parameterization is also derived, capable of reproducing the hygroscopic growth factor (f(RH within 15 % of the measured values. The highest aerosol water concentrations are observed during nighttime, when relative humidity is highest and the collapse of the boundary layer increases the aerosol concentration. A significant diurnal variability is found for Worg with morning and afternoon average mass concentrations being 10–15 times lower than nighttime concentrations, thus rendering Winorg the main form of particle water during daytime. The average value of total aerosol water was 2.19 ± 1.75 µg m−3, contributing on average up to 33 % of the total submicron mass concentration. Average aerosol water associated with

  8. Roosting Colony of Cormorants (Phalacrocorax Carbo Sinensis L. as a Source of Nutrients for the Lake

    Directory of Open Access Journals (Sweden)

    Piotr Klimaszyk

    2015-03-01

    Full Text Available Since 2005, great cormorants have been observed on the Lake Góreckie (Wielkopolski National Park shoreline. The population of these birds occurring within the lake has gradually increased. In autumn 2008, more than 100 individuals were observed. In the period 2009-2012 the number of birds occupying the island periodically exceeded 250 individuals. So far, there is no breeding colony of great cormorants, but the birds have established a roosting colony on the island. In the period 2009-2012 we conducted research on the impact of the colony of great cormorants on the accumulation of nitrogen, phosphorus and other elements in soils beneath the colony and transfer of chemical elements from the colony to a nearby freshwater ecosystem. Our results show that a relatively small and recent colony of great cormorants can significantly affect the chemistry of soil. Compared to a control, the soil beneath the colony was characterized by statistically higher concentrations of nitrogen and phosphorus. A significant accumulation of nutrients was observed in the topsoil zone (to a depth of about 20 cm. Enrichment of soil in chemical elements has resulted in their further transport to a nearby lake. Compared to the control, the groundwater and surface runoff from the colony area revealed several-fold higher concentrations of nitrogen and phosphorus. The maximum abundance of cormorants in the roosting colony was reflected in the elevated concentrations of nitrogen and phosphorus in the littoral water near the colony. Our study demonstrates that the roosting colony of great cormorants can play a significant role in accelerating the eutrophication of surface waters.

  9. Nutrient removal by prairie filter strips in agricultural landscapes

    Science.gov (United States)

    X. Zhou; M.J. Helmers; H. Asbjornsen; R. Kolka; M.D. Tomer; R.M. Cruse

    2014-01-01

    Nitrogen (N) and phosphorus (P) from agricultural landscapes have been identified as primary sources of excess nutrients in aquatic systems. The main objective of this study was to evaluate the effectiveness of prairie filter strips (PFS) in removing nutrients from cropland runoff in 12 small watersheds in central Iowa. Four treatments with PFS of different spatial...

  10. Food Sources of Energy and Nutrients among Children in the United States: National Health and Nutrition Examination Survey 2003–2006

    Science.gov (United States)

    Keast, Debra R.; Fulgoni III, Victor L.; Nicklas, Theresa A.; O’Neil, Carol E.

    2013-01-01

    Background: Recent detailed analyses of data on dietary sources of energy and nutrients in US children are lacking. The objective of this study was to identify food sources of energy and 28 nutrients for children in the United States. Methods: Analyses of food sources were conducted using a single 24-h recall collected from children 2 to 18 years old (n = 7332) in the 2003–2006 National Health and Nutrition Examination Survey. Sources of nutrients contained in foods were determined using nutrient composition databases. Food grouping included ingredients from disaggregated mixtures. Mean energy and nutrient intakes from the total diet and from each food group were adjusted for the sample design using appropriate weights. Percentages of the total dietary intake that food sources contributed were tabulated by rank order. Results: The two top ranked food/food group sources of energy and nutrients were: energy—milk (7% of energy) and cake/cookies/quick bread/pastry/pie (7%); protein—milk (13.2%) and poultry (12.8%); total carbohydrate—soft drinks/soda (10.5%) and yeast bread/rolls (9.1%); total sugars—soft drinks/soda (19.2%) and yeast breads and rolls (12.7%); added sugars—soft drinks/soda (29.7%) and candy/sugar/sugary foods (18.6%); dietary fiber—fruit (10.4%) and yeast bread/rolls (10.3%); total fat—cheese (9.3%) and crackers/popcorn/pretzels/chips (8.4%); saturated fatty acids—cheese (16.3%) and milk (13.3%); cholesterol—eggs (24.2%) and poultry (13.2%); vitamin D—milk (60.4%) and milk drinks (8.3%); calcium—milk (33.2%) and cheese (19.4%); potassium—milk (18.8%) and fruit juice (8.0%); and sodium—salt (18.5%) and yeast bread and rolls (8.4%). Conclusions: Results suggest that many foods/food groupings consumed by children were energy dense, nutrient poor. Awareness of dietary sources of energy and nutrients can help health professionals design effective strategies to reduce energy consumption and increase the nutrient density of

  11. Food Sources of Energy and Nutrients among Children in the United States: National Health and Nutrition Examination Survey 2003–2006

    Directory of Open Access Journals (Sweden)

    Victor L. Fulgoni

    2013-01-01

    Full Text Available Background: Recent detailed analyses of data on dietary sources of energy and nutrients in US children are lacking. The objective of this study was to identify food sources of energy and 28 nutrients for children in the United States. Methods: Analyses of food sources were conducted using a single 24-h recall collected from children 2 to 18 years old (n = 7332 in the 2003–2006 National Health and Nutrition Examination Survey. Sources of nutrients contained in foods were determined using nutrient composition databases. Food grouping included ingredients from disaggregated mixtures. Mean energy and nutrient intakes from the total diet and from each food group were adjusted for the sample design using appropriate weights. Percentages of the total dietary intake that food sources contributed were tabulated by rank order. Results: The two top ranked food/food group sources of energy and nutrients were: energy — milk (7% of energy and cake/cookies/quick bread/pastry/pie (7%; protein — milk (13.2% and poultry (12.8%; total carbohydrate — soft drinks/soda (10.5% and yeast bread/rolls (9.1%; total sugars — soft drinks/soda (19.2% and yeast breads and rolls (12.7%; added sugars — soft drinks/soda (29.7% and candy/sugar/sugary foods (18.6%; dietary fiber — fruit (10.4% and yeast bread/rolls (10.3%; total fat — cheese (9.3% and crackers/popcorn/pretzels/chips (8.4%; saturated fatty acids — cheese (16.3% and milk (13.3%; cholesterol — eggs (24.2% and poultry (13.2%; vitamin D — milk (60.4% and milk drinks (8.3%; calcium — milk (33.2% and cheese (19.4%; potassium — milk (18.8% and fruit juice (8.0%; and sodium — salt (18.5% and yeast bread and rolls (8.4%. Conclusions: Results suggest that many foods/food groupings consumed by children were energy dense, nutrient poor. Awareness of dietary sources of energy and nutrients can help health professionals design effective strategies to reduce energy consumption and increase the nutrient

  12. Food sources of energy and nutrients among children in the United States: National Health and Nutrition Examination Survey 2003–2006.

    Science.gov (United States)

    Keast, Debra R; Fulgoni, Victor L; Nicklas, Theresa A; O'Neil, Carol E

    2013-01-22

    Recent detailed analyses of data on dietary sources of energy and nutrients in US children are lacking. The objective of this study was to identify food sources of energy and 28 nutrients for children in the United States. Analyses of food sources were conducted using a single 24-h recall collected from children 2 to 18 years old (n = 7332) in the 2003-2006 National Health and Nutrition Examination Survey. Sources of nutrients contained in foods were determined using nutrient composition databases. Food grouping included ingredients from disaggregated mixtures. Mean energy and nutrient intakes from the total diet and from each food group were adjusted for the sample design using appropriate weights. Percentages of the total dietary intake that food sources contributed were tabulated by rank order. The two top ranked food/food group sources of energy and nutrients were: energy - milk (7% of energy) and cake/cookies/quick bread/pastry/pie (7%); protein - milk (13.2%) and poultry (12.8%); total carbohydrate - soft drinks/soda (10.5%) and yeast bread/rolls (9.1%); total sugars - soft drinks/soda (19.2%) and yeast breads and rolls (12.7%); added sugars - soft drinks/soda (29.7%) and candy/sugar/sugary foods (18.6%); dietary fiber - fruit (10.4%) and yeast bread/rolls (10.3%); total fat - cheese (9.3%) and crackers/popcorn/pretzels/chips (8.4%); saturated fatty acids - cheese (16.3%) and milk (13.3%); cholesterol - eggs (24.2%) and poultry (13.2%); vitamin D - milk (60.4%) and milk drinks (8.3%); calcium - milk (33.2%) and cheese (19.4%); potassium - milk (18.8%) and fruit juice (8.0%); and sodium - salt (18.5%) and yeast bread and rolls (8.4%). Results suggest that many foods/food groupings consumed by children were energy dense, nutrient poor. Awareness of dietary sources of energy and nutrients can help health professionals design effective strategies to reduce energy consumption and increase the nutrient density of children's diets.

  13. Food Sources of Energy and Nutrients in Infants, Toddlers, and Young Children from the Mexican National Health and Nutrition Survey 2012.

    Science.gov (United States)

    Denney, Liya; Afeiche, Myriam C; Eldridge, Alison L; Villalpando-Carrión, Salvador

    2017-05-13

    Food sources of nutrients in Mexican children are not well known. To fill the knowledge gap, dietary intake was assessed in 2057 children using a 24-hour dietary recall. All reported foods and beverages were assigned to one of 76 food groups. Percent contribution of each food group to nutrient intake was estimated for four age groups: 0-5.9, 6-11.9, 12-23.9, and 24-47.9 months. Breast milk, infant formula, and cow's milk were the top sources of energy and nutrients, especially in younger groups. Among infants aged 6-11.9 months, the top food sources of energy included soups and stews, cookies, fruit, tortillas, eggs and egg dishes, and traditional beverages. The same foods plus sweetened breads, dried beans, and sandwiches and tortas were consumed as the top sources of energy among toddlers and young children. Milk, soups, and stews were the top contributors for all nutrients and tortillas, eggs, and egg dishes were among the top contributors for iron and zinc. This study showed that low nutrient-dense cookies, sweetened breads, and traditional beverages were among the core foods consumed early in life in Mexico. This compromises the intake of more nutritious foods such as vegetables and fortified cereals and increases the risk of obesity.

  14. The primary ion source for construction and optimization of operation parameters

    International Nuclear Information System (INIS)

    Synowiecki, A.; Gazda, E.

    1986-01-01

    The construction of primary ion source for SIMS has been presented. The influence of individual operation parameters on the properties of ion source has been investigated. Optimization of these parameters has allowed to appreciate usefulness of the ion source for SIMS study. 14 refs., 8 figs., 2 tabs. (author)

  15. Implementing Open Source Platform for Education Quality Enhancement in Primary Education: Indonesia Experience

    Science.gov (United States)

    Kisworo, Marsudi Wahyu

    2016-01-01

    Information and Communication Technology (ICT)-supported learning using free and open source platform draws little attention as open source initiatives were focused in secondary or tertiary educations. This study investigates possibilities of ICT-supported learning using open source platform for primary educations. The data of this study is taken…

  16. Uprooting an abscisic acid paradigm: Shoots are the primary source.

    Science.gov (United States)

    McAdam, Scott A M; Manzi, Matías; Ross, John J; Brodribb, Timothy J; Gómez-Cadenas, Aurelio

    2016-06-02

    In the past, a conventional wisdom has been that abscisic acid (ABA) is a xylem-transported hormone that is synthesized in the roots, while acting in the shoot to close stomata in response to a decrease in plant water status. Now, however, evidence from two studies, which we have conducted independently, challenges this root-sourced ABA paradigm. We show that foliage-derived ABA has a major influence over root development and that leaves are the predominant location for ABA biosynthesis during drought stress.

  17. Nutrient balancing of the adult worker bumblebee (Bombus terrestris) depends on the dietary source of essential amino acids.

    Science.gov (United States)

    Stabler, Daniel; Paoli, Pier P; Nicolson, Susan W; Wright, Geraldine A

    2015-03-01

    Animals carefully regulate the amount of protein that they consume. The quantity of individual essential amino acids (EAAs) obtained from dietary protein depends on the protein source, but how the proportion of EAAs in the diet affects nutrient balancing has rarely been studied. Recent research using the Geometric Framework for Nutrition has revealed that forager honeybees who receive much of their dietary EAAs from floral nectar and not from solid protein have relatively low requirements for dietary EAAs. Here, we examined the nutritional requirements for protein and carbohydrates of foragers of the buff-tailed bumblebee Bombus terrestris. By using protein (sodium caseinate) or an equimolar mixture of the 10 EAAs, we found that the intake target (nutritional optimum) of adult workers depended on the source and proportion of dietary EAAs. When bees consumed caseinate-containing diets in a range of ratios between 1:250 and 1:25 (protein to carbohydrate), they achieved an intake target (IT) of 1:149 (w/w). In contrast to those fed protein, bees fed the EAA diets had an IT more biased towards carbohydrates (1:560 w/w) but also had a greater risk of death than those fed caseinate. We also tested how the dietary source of EAAs affected free AAs in bee haemolymph. Bees fed diets near their IT had similar haemolymph AA profiles, whereas bees fed diets high in caseinate had elevated levels of leucine, threonine, valine and alanine in the haemolymph. We found that like honeybees, bumblebee workers prioritize carbohydrate intake and have a relatively low requirement for protein. The dietary source of EAAs influenced both the ratio of protein/EAA to carbohydrate and the overall amount of carbohydrate eaten. Our data support the idea that EAAs and carbohydrates in haemolymph are important determinants of nutritional state in insects. © 2015. Published by The Company of Biologists Ltd.

  18. Urbanization effects on leaf litter decomposition, foliar nutrient dynamics and aboveground net primary productivity in the subtropics

    Science.gov (United States)

    Heather A. Enloe; B. Graeme Lockaby; Wayne C. Zipperer; Greg L. Somers

    2015-01-01

    Urbanization can alter nutrient cycling. This research evaluated how urbanization affected nutrient dynamics in the subtropics. We established 17–0.04 ha plots in five different land cover types—slash pine (Pinus elliottii) plantations (n=3), rural natural pine forests (n= 3), rural natural oak forests (n=4), urban pine forests (n=3) and urban oak forests (n=4) in the...

  19. Aspectos econômicos do uso de fontes orgânicas de nutrientes associadas a sistemas de preparo do solo Economical aspects of organic nutrient sources associated with soil tillage systems

    Directory of Open Access Journals (Sweden)

    Carla Maria Pandolfo

    2008-09-01

    ário, P e K, após nove anos de aplicação das fontes de nutrientes, tem importante participação no desempenho econômico das mesmas.Economical analysis is important to make decision on the use of organic nutrient sources. The objective of this study was to elaborate an economical analysis of different nutrient sources to help farmers and technicians to make decision about the use of these sources at different soil management. The study was carried out at the Epagri Experimental Station of Campos Novos, using a long-term experiment. The treatments were a combination of five tillage systems (no-till; chisel plow; conventional tillage; conventional tillage with crop residues burned and conventional tillage with crop residues removed from the field, with four nutrient sources (TES=control, no fertilizer; AM=mineral fertilizer according with technical recommendation for each crop; EA=5mg ha-1 of moisture poultry litter; ELB=60m³ ha-1 of liquid cattle manure; and ELS=40m³ ha-1 of slurry pig manure. The economical attributes used were variable costs of production, total income, and the cost of the necessity of lime and fertilizers application to improve soil chemical condition after nine years of applying treatments. A model was used to quantify and analyse the effect of nutrient sources in economical aspects, for each nutrient source within each soil tillage. The outputs were triangular pictures and their areas with 90% confidence limits. It was concluded that economical aspect effects of the organic nutrient sources were dependent on tillage systems, and the better performance was in no-till system. EA and ELS showed better economical results. ELS and ELB, even showing different picture areas, were the sources that showed lesser variability in economical attribute evaluated, and did not have one highlight attribute among them. The use of cost of the necessity of lime and fertilizers application to improve soil chemical condition after nine years of applying treatments

  20. Anomaly metrics to differentiate threat sources from benign sources in primary vehicle screening.

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Israel Dov; Mengesha, Wondwosen

    2011-09-01

    Discrimination of benign sources from threat sources at Port of Entries (POE) is of a great importance in efficient screening of cargo and vehicles using Radiation Portal Monitors (RPM). Currently RPM's ability to distinguish these radiological sources is seriously hampered by the energy resolution of the deployed RPMs. As naturally occurring radioactive materials (NORM) are ubiquitous in commerce, false alarms are problematic as they require additional resources in secondary inspection in addition to impacts on commerce. To increase the sensitivity of such detection systems without increasing false alarm rates, alarm metrics need to incorporate the ability to distinguish benign and threat sources. Principal component analysis (PCA) and clustering technique were implemented in the present study. Such techniques were investigated for their potential to lower false alarm rates and/or increase sensitivity to weaker threat sources without loss of specificity. Results of the investigation demonstrated improved sensitivity and specificity in discriminating benign sources from threat sources.

  1. Enhanced Nutrients Removal Using Reeds Straw as Carbon Source in a Laboratory Scale Constructed Wetland

    Directory of Open Access Journals (Sweden)

    Tong Wang

    2018-05-01

    Full Text Available The low carbon/nitrogen (C/N ratio and high nitrate content characteristics of agricultural runoff restricted the nitrogen removal in constructed wetlands (CWs. To resolve such problems, the economically- and easily-obtained Phragmites Australis (reeds litters were applied and packed in the surface layer of a surface flow CW as external carbon sources. The results demonstrated that the introduction of the reeds straw increased the C concentration as a result of their decomposition during the CW operation, which will help the denitrification in the ensuing operation of an entire 148 days. The total nitrogen (TN and Chemical Oxygen Demand (COD ( in the effluent reached the peak level of 63.2 mg/L and 83 mg/L at the fourth and the second day, respectively. Subsequently, the pollutants in the CW that were filled with straw decreased rapidly and achieved a stable removal after 13 days of operation. Moreover, the present study showed that the N removal efficiency increased with the increase of the hydraulic retention time (HRT. Under the HRT of four days, the CW presented 74.1 ± 6%, 87.4 ± 6% and 56.0 ± 6% removal for TN, NO3-, and TP, respectively.

  2. Entrapped Sediments as a Source of Phosphorus in Epilithic Cyanobacterial Proliferations in Low Nutrient Rivers

    Science.gov (United States)

    Wood, Susanna A.; Depree, Craig; Brown, Logan; McAllister, Tara; Hawes, Ian

    2015-01-01

    Proliferations of the benthic mat-forming cyanobacteria Phormidium have been reported in rivers worldwide. Phormidium commonly produces natural toxins which pose a health risk to animal and humans. Recent field studies in New Zealand identified that sites with Phormidium proliferations consistently have low concentrations of water column dissolved reactive phosphorus (DRP). Unlike other river periphyton, Phormidium mats are thick and cohesive, with water and fine sediment trapped in a mucilaginous matrix. We hypothesized that daytime photosynthetic activity would elevate pH inside the mats, and/or night time respiration would reduce dissolved oxygen. Either condition could be sufficient to facilitate desorption of phosphates from sediment incorporated within mats, thus allowing Phormidium to utilize it for growth. Using microelectrodes, optodes and pulse amplitude modulation fluorometry we demonstrated that photosynthetic activity results in elevated pH (>9) during daytime, and that night-time respiration causes oxygen depletion (river water and this, together with elevated concentrations of elements, including iron, suggest phosphorus release from entrapped sediment. Sequential extraction of phosphorus from trapped sediment was used to investigate the role of sediment at sites on the Mangatainoka River (New Zealand) with and without Phormidium proliferations. Deposition of fine sediment (sediment can provide a source of phosphorus to support Phormidium growth and proliferation. PMID:26479491

  3. A Study of the Efficacy of Various Nutrient Sources on the Growth and Yield of Cabbage

    Directory of Open Access Journals (Sweden)

    Moch. Dawam Maghfoer

    2018-02-01

    Full Text Available Research evaluated various nitrogen sources, and a supplementary foliar fertilizer or biochar on cabbage. It was conducted from July to October 2014 in Poncokusumo, Malang ca. 600 meters above sea level. The experiment used a randomized block design with four replications. The treatments were fertilized with different concentrations of urea, goat manure and selected substances i.e. 100% N urea (controls; 75% N urea + 25% N goat manure; 50% N urea + 50% N goat manure; 75% N urea + 25% N goat manure + foliar fertilizer (6-30-30, 50% N urea + 50% N goat manure + foliar fertilizer (6-30-30; 75% N urea + 25% N manure + biochar; and 50% N urea + 50% N goat manure + biochar. The dose of N fertilizer used was 69 kg ha-1. The results showed that a higher yield was recorded in the application of 75% N urea + 25% N goat manure and 50% N urea + 50% N manure with an addition of foliar fertilizer that was not significant with the application of 75% N urea + 25% N goat manure with the addition of biochar, resulting in a marketable yield of 68.84, 66.5 and 64.75 t ha-1, respectively.

  4. Effect of dietary carbohydrate sources on apparent nutrient digestibility of olive flounder (Paralichthys olivaceus feed

    Directory of Open Access Journals (Sweden)

    Md Mostafizur Rahman

    2016-06-01

    Full Text Available Abstract Apparent digestibility coefficients (ADCs of dry matter, crude protein, crude lipid, nitrogen-free extract, and energy in selected carbohydrate sources including wheat flour (WF, α-potato starch (PS, α-corn starch (CS, Na alginate (AL, dextrin (DEX, and carboxymethyl cellulose (CMC were determined for olive flounder. The olive flounder averaging 150 ± 8.0 g were held in 300-L tanks at a density of 30 fish per tank. Chromic oxide was used as the inert marker. Feces were collected from the flounder by a fecal collector attached to a fish rearing tank. Apparent dry matter and energy digestibilities of flounder fed WF, PS, CS, and DEX diets were significantly higher than those of fish fed AL and CMC diets. Apparent crude protein digestibility coefficients of flounder fed PS and CS diets were significantly higher than those of fish fed AL, DEX, and CMC diets. Apparent crude lipid and nitrogen-free extract digestibility coefficients of flounder fed PS and DEX diets were significantly higher than those of fish fed WF, CS, AL, and CMC diets. The present findings indicate that PS and DEX could be effectively used as dietary carbohydrate energy compared to WF, CS, AL, and CMC for olive flounder.

  5. Evaluation of nutrient and energy sources of the deepest known serpentinite-hosted ecosystem using stable carbon, nitrogen, and sulfur isotopes.

    Science.gov (United States)

    Onishi, Yuji; Yamanaka, Toshiro; Okumura, Tomoyo; Kawagucci, Shinsuke; Watanabe, Hiromi Kayama; Ohara, Yasuhiko

    2018-01-01

    The Shinkai Seep Field (SSF) in the southern Mariana forearc discovered in 2010 is the deepest (~5,700 m in depth) known serpentinite-hosted ecosystem dominated by a vesicomyid clam, Calyptogena (Abyssogena) mariana. The pioneering study presumed that the animal communities are primary sustained by reducing fluid originated from the serpentinization of mantle peridotite. For understanding the nutrient and energy sources for the SSF community, this study conducted four expeditions to the SSF and collected additional animal samples such as polychaetes and crustaceans as well as sediments, fragments of chimneys developing on fissures of serpentinized peridotite, seeping fluid on the chimneys, and pore water within the chimneys. Geochemical analyses of seeping fluids on the chimneys and pore water of the chimneys revealed significantly high pH (~10) that suggest subseafloor serpentinization controlling fluid chemistry. Stable isotope systematics (carbon, nitrogen, and sulfur) among animals, inorganic molecules, and environmental organic matter suggest that the SSF animal community mostly relies on the chemosynthetic production while some organisms appear to partly benefit from photosynthetic production despite the great depth of SSF.

  6. Diagnostic Air Quality Model Evaluation of Source-Specific Primary and Secondary Fine Particulate Carbon

    Science.gov (United States)

    Ambient measurements of 78 source-specific tracers of primary and secondary carbonaceous fine particulate matter collected at four midwestern United States locations over a full year (March 2004–February 2005) provided an unprecedented opportunity to diagnostically evaluate...

  7. Basaltic substrate composition affects microbial community development and acts as a source of nutrients in the deep biosphere

    Science.gov (United States)

    Bailey, B.; Sudek, L.; Templeton, A.; Staudigel, H.; Tebo, B.; Moyer, C.; Davis, R.

    2006-12-01

    Studies of the oceanic crust over the past decade have revealed that in spite of the oligotrophic nature of this environment, a diverse biosphere is present in the upper 1 km of basaltic crust. The key energy source in this setting may be the high content of transistion metals (Fe, Mn) found in the basaltic glass, but in order to discover the role of Fe and Mn in the deep biosphere, we must first determine which microbes are present and how they attain the necessary metabolites for proliferation. Our work contributes to both questions through the use of molecular microbiology techniques and the exposure of specifically designed substrates on the ocean floor. Loihi Seamount off the southeast coast of the Big Island of Hawai'i provides a unique laboratory for the study of distribution and population of microbial communities associated with iron rich environments on the ocean floor. Iron oxide flocculent material (floc) dominates the direct and diffuse hydrothermal venting areas on Loihi which makes it a prime target for understanding the role of iron in biological systems in the deep biosphere. We collected iron oxide floc and basaltic glass from pillow basalts around several hydrothermal vents on the crater rim, within the pit crater Pele's Pit, and from deep off of the southern rift zone of Loihi using the HURL PISCES IV/V submersibles. We also deployed basaltic glass sand amended with various nutrients (phosphate, oxidized and reduced iron, manganese) and recovered them in subsequent years to determine how substrate composition affects community structure. We extracted DNA from both rock and iron flocs and used t-RFLP to obtain a genetic fingerprint of the microbial communities associated with each substrate. From olivine and tholeiitic basalt enrichments, it appears that substrate composition strongly influences microbial colonization and subsequent community development even when deployed in the same conditions. Culturing efforts have yielded several iron

  8. Atmospheric deposition as a source of carbon and nutrients to barren, alpine soils of the Colorado Rocky Mountains

    Science.gov (United States)

    Mladenov, N.; Williams, M. W.; Schmidt, S. K.; Cawley, K.

    2012-03-01

    Many alpine areas are experiencing intense deglaciation, biogeochemical changes driven by temperature rise, and changes in atmospheric deposition. There is mounting evidence that the water quality of alpine streams may be related to these changes, including rising atmospheric deposition of carbon (C) and nutrients. Given that barren alpine soils can be severely C limited, we evaluated the magnitude and chemical quality of atmospheric deposition of C and nutrients to an alpine site, the Green Lake 4 catchment in the Colorado Rocky Mountains. Using a long term dataset (2002-2010) of weekly atmospheric wet deposition and snowpack chemistry, we found that volume weighted mean dissolved organic carbon (DOC) concentrations were approximately 1.0 mg L-1and weekly concentrations reached peaks as high at 6-10 mg L-1 every summer. Total dissolved nitrogen concentration also peaked in the summer, whereas total dissolved phosphorus and calcium concentrations were highest in the spring. Relationships among DOC concentration, dissolved organic matter (DOM) fluorescence properties, and nitrate and sulfate concentrations suggest that pollutants from nearby urban and agricultural sources and organic aerosols derived from sub-alpine vegetation may influence high summer DOC wet deposition concentrations. Interestingly, high DOC concentrations were also recorded during "dust-in-snow" events in the spring. Detailed chemical and spectroscopic analyses conducted for samples collected in 2010 revealed that the DOM in many late spring and summer samples was less aromatic and polydisperse and of lower molecular weight than that of winter and fall samples and, therefore, likely to be more bioavailable to microbes in barren alpine soils. Bioavailability experiments with different types of atmospheric C sources are needed to better evaluate the substrate quality of atmospheric C inputs. Our C budget estimates for the Green Lake 4 catchment suggest that atmospheric deposition represents an

  9. Effect of Carbohydrate Source and Cottonseed Meal Level in the Concentrate on Feed Intake, Nutrient Digestibility, Rumen Fermentation and Microbial Protein Synthesis in Swamp Buffaloes

    Directory of Open Access Journals (Sweden)

    M. Wanapat

    2013-07-01

    Full Text Available The objective of this study was to investigate the effect of carbohydrate source and cottonseed meal level in the concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in swamp buffaloes. Four, 4-yr old rumen fistulated swamp buffaloes were randomly assigned to receive four dietary treatments according to a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was carbohydrate source; cassava chip (CC and CC+rice bran at a ratio 3:1 (CR3:1, and factor B was level of cottonseed meal (CM; 109 g CP/kg (LCM and 328 g CP/kg (HCM in isonitrogenous diets (490 g CP/kg. Buffaloes received urea-treated rice straw ad libitum and supplemented with 5 g concentrate/kg BW. It was found that carbohydrate source did not affect feed intake, nutrient intake, digested nutrients, nutrient digestibility, ammonia nitrogen concentration, fungi and bacterial populations, or microbial protein synthesis (p>0.05. Ruminal pH at 6 h after feeding and the population of protozoa at 4 h after feeding were higher when buffalo were fed with CC than in the CR3:1 treatment (p0.05. Based on this experiment, concentrate with a low level of cottonseed meal could be fed with cassava chips as an energy source in swamp buffalo receiving rice straw.

  10. Nutrient Intake Is Insufficient among Senegalese Urban School Children and Adolescents: Results from Two 24 h Recalls in State Primary Schools in Dakar

    Directory of Open Access Journals (Sweden)

    Marion Fiorentino

    2016-10-01

    Full Text Available Due to rapid urbanization and high food prices and in the absence of nutrition programs, school children from urban areas in West Africa often have insufficient and inadequate diet leading to nutrient deficiencies that affect their health and schooling performance. Acute malnutrition and micronutrient deficiencies are prevalent in children from primary state schools of Dakar (Senegal. The objectives of the present study were to assess the overall diet of these children, to report insufficient/excessive energy and nutrient intakes and to investigate association between insufficient nutrient intake and micronutrient deficiencies. Children attending urban state primary schools in the Dakar area were selected through a two-stage random cluster sampling (30 schools × 20 children. Dietary intake data were obtained from two 24 h recalls and blood samples were collected from 545 children (aged 5–17 years, 45% < 10 years, 53% girls and adjusted for intra-individual variability to estimate nutrient usual intakes. Energy intake was insufficient and unbalanced with insufficient contribution of protein and excessive contribution of fat to global energy intake in one third of the children. Proportions of children with insufficient intake were: 100% for calcium, 100% for folic acid, 79% for vitamin A, 69% for zinc, 53% for vitamin C and 46% for iron. Insufficient iron and protein intake were risk factors for iron deficiency (odds ratio, OR 1.5, 2.2. Insufficient zinc intake and energy intake from protein were risk factors for zinc deficiency (OR 1.8, 3.0, 1.7, 2.9. Insufficient iron and vitamin C intake, and insufficient energy intake from protein were risk factors for marginal vitamin A status (OR 1.8, 1.8, 3.3. To address nutritional deficiencies associated with a diet deficient in energy, protein and micronutrients, nutrition education or school feeding programs are needed in urban primary schools of Senegal.

  11. Nutrient Intake Is Insufficient among Senegalese Urban School Children and Adolescents: Results from Two 24 h Recalls in State Primary Schools in Dakar

    Science.gov (United States)

    Fiorentino, Marion; Landais, Edwige; Bastard, Guillaume; Carriquiry, Alicia; Wieringa, Frank T.; Berger, Jacques

    2016-01-01

    Due to rapid urbanization and high food prices and in the absence of nutrition programs, school children from urban areas in West Africa often have insufficient and inadequate diet leading to nutrient deficiencies that affect their health and schooling performance. Acute malnutrition and micronutrient deficiencies are prevalent in children from primary state schools of Dakar (Senegal). The objectives of the present study were to assess the overall diet of these children, to report insufficient/excessive energy and nutrient intakes and to investigate association between insufficient nutrient intake and micronutrient deficiencies. Children attending urban state primary schools in the Dakar area were selected through a two-stage random cluster sampling (30 schools × 20 children). Dietary intake data were obtained from two 24 h recalls and blood samples were collected from 545 children (aged 5–17 years, 45% < 10 years, 53% girls) and adjusted for intra-individual variability to estimate nutrient usual intakes. Energy intake was insufficient and unbalanced with insufficient contribution of protein and excessive contribution of fat to global energy intake in one third of the children. Proportions of children with insufficient intake were: 100% for calcium, 100% for folic acid, 79% for vitamin A, 69% for zinc, 53% for vitamin C and 46% for iron. Insufficient iron and protein intake were risk factors for iron deficiency (odds ratio, OR 1.5, 2.2). Insufficient zinc intake and energy intake from protein were risk factors for zinc deficiency (OR 1.8, 3.0, 1.7, 2.9). Insufficient iron and vitamin C intake, and insufficient energy intake from protein were risk factors for marginal vitamin A status (OR 1.8, 1.8, 3.3). To address nutritional deficiencies associated with a diet deficient in energy, protein and micronutrients, nutrition education or school feeding programs are needed in urban primary schools of Senegal. PMID:27775598

  12. Recent Warming, Rather than Industrial Emissions of Bioavailable Nutrients, Is the Dominant Driver of Lake Primary Production Shifts across the Athabasca Oil Sands Region.

    Directory of Open Access Journals (Sweden)

    Jamie C Summers

    Full Text Available Freshwaters in the Athabasca Oil Sands Region (AOSR are vulnerable to the atmospheric emissions and land disturbances caused by the local oil sands industry; however, they are also affected by climate change. Recent observations of increases in aquatic primary production near the main development area have prompted questions about the principal drivers of these limnological changes. Is the enhanced primary production due to deposition of nutrients (nitrogen and phosphorus from local industry or from recent climatic changes? Here, we use downcore, spectrally-inferred chlorophyll-a (VRS-chla profiles (including diagenetic products from 23 limnologically-diverse lakes with undisturbed catchments to characterize the pattern of primary production increases in the AOSR. Our aim is to better understand the relative roles of the local oil sands industry versus climate change in driving aquatic primary production trends. Nutrient deposition maps, generated using geostatistical interpolations of spring-time snowpack measurements from a grid pattern across the AOSR, demonstrate patterns of elevated total phosphorus, total nitrogen, and bioavailable nitrogen deposition around the main area of industrial activity. However, this pattern is not observed for bioavailable phosphorus. Our paleolimnological findings demonstrate consistently greater VRS-chla concentrations compared to pre-oil sands development levels, regardless of morphological and limnological characteristics, landscape position, bioavailable nutrient deposition, and dibenzothiophene (DBT-inferred industrial impacts. Furthermore, breakpoint analyses on VRS-chla concentrations across a gradient of DBT-inferred industrial impact show limited evidence of a contemporaneous change among lakes. Despite the contribution of bioavailable nitrogen to the landscape from industrial activities, we find no consistency in the spatial pattern and timing of VRS-chla shifts with an industrial fertilizing signal

  13. Perceived Sources of Occupational Stress among Primary School Teachers in Delta State of Nigeria

    Science.gov (United States)

    Akpochafo, G. O.

    2012-01-01

    This study investigated the most prevalent sources of occupational stress and also the demographic variables of gender, age and length of service among primary school teachers in Delta State. Two research questions and three hypotheses guided the study. The study used a descriptive survey design. The population was the primary school teachers in…

  14. Fine particle water and pH in the Eastern Mediterranean: Sources, variability and implications for nutrients availability

    Science.gov (United States)

    Bougiatioti, Aikaterini; Nikolaou, Panayiota; Stavroulas, Iasonas; Kouvarakis, Giorgos; Nenes, Athanasios; Weber, Rodney; Kanakidou, Maria; Mihalopoulos, Nikolaos

    2016-04-01

    total calculated water. Particle pH is also calculated with the help of ISORROPIA-II, and during the studied period, values varied from 0.5 to 2.8, indicating that the aerosol was highly acidic. pH values were also studied depending on the source/origin of the sampled air masses and biomass burning aerosol was found to exhibit the highest values of PM1 pH and the lowest values in total water mass concentrations. The two natural sources, namely mineral and marine origin, contained the largest amounts of total submicron water and the lowest contribution of organic water, as expected. The low pH values estimated for the studied period in the submicron mode and independently of the air masses' origin could potentially have important implications for nutrient availability, especially for phosphorus solubility, which is the nutrient limiting sea water productivity of the Eastern Mediterranean.

  15. Primary Nutritional Content of Bio-Flocs Cultured with Different Organic Carbon Sources and Salinity

    Directory of Open Access Journals (Sweden)

    JULIE EKASARI

    2010-09-01

    Full Text Available Application of bio-flocs technology (BFT in aquaculture offers a solution to avoid environmental impact of high nutrient discharges and to reduce the use of artificial feed. In BFT, excess of nutrients in aquaculture systems are converted into microbial biomass, which can be consumed by the cultured animals as a food source. In this experiment, upconcentrated pond water obtained from the drum filter of a freshwater tilapia farm was used for bio-flocs reactors. Two carbon sources, sugar and glycerol, were used as the first variable, and two different levels of salinity, 0 and 30 ppt, were used as the second variable. Bio-flocs with glycerol as a carbon source had higher total n-6 PUFAs (19.1 ± 2.1 and 22.3 ± 8.6 mg/g DW at 0 and 30 ppt, respectively than that of glucose (4.0 ± 0.1 and 12.6 ± 2.5 mg/g DW at 0 and 30 ppt. However, there was no effect of carbon source or salinity on crude protein, lipid, and total n-3 PUFAs contents of the bio-flocs.

  16. Potential of lees from wine, beer and cider manufacturing as a source of economic nutrients: An overview.

    Science.gov (United States)

    Pérez-Bibbins, B; Torrado-Agrasar, A; Salgado, J M; Oliveira, R Pinheiro de Souza; Domínguez, J M

    2015-06-01

    Lees are the wastes generated during the fermentation and aging processes of different industrial activities concerning alcoholic drinks such as wine, cider and beer. They must be conveniently treated to avoid uncontrolled dumping which causes environmental problems due to their high content of phenols, pesticides, heavy metals, and considerable concentrations of nitrogen, phosphate and potassium as well as high organic content. The companies involved must seek alternative environmental and economic physicochemical and biological treatments for their revalorization consisting in the recovery or transformation of the components of the lees into high value-added compounds. After describing the composition of lees and market of wine, beer and cider industries in Spain, this work aims to review the recent applications of wine, beer and cider lees reported in literature, with special attention to the use of lees as an endless sustainable source of nutrients and the production of yeast extract by autolysis or cell disruption. Lees and/or yeast extract can be used as nutritional supplements with potential exploitation in the biotechnological industry for the production of natural compounds such as xylitol, organic acids, and biosurfactants, among others. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Access to primary energy sources - the basis of national energy security

    Science.gov (United States)

    Szlązak, Jan; Szlązak, Rafał A.

    2017-11-01

    National energy security is of fundamental importance for economic development of a country. To ensure such safety energy raw material, also called primary energy sources, are necessary. Currently in Poland primary energy sources include mainly fossil fuels, such as hard coal, brown coal, natural gas and crude oil. Other sources, e.g. renewable energy sources account for c. 15% in the energy mix. Primary energy sources are used to produce mainly electricity, which is considered as the cleanest form of energy. Poland does not have, unfortunately, sufficient energy sources and is forced to import some of them, mainly natural gas and crude oil. The article presents an insightful analysis of energy raw material reserves possessed by Poland and their structure taking account of the requirements applicable in the European Union, in particular, those related to environmental protection. The article also describes demand for electricity now and in the perspective of 2030. Primary energy sources necessary for its production have also been given. The article also includes the possibilities for the use of renewable energy sources in Poland, however, climatic conditions there are not are not particularly favourable to it. All the issues addressed in the article are summed up and ended with conclusions.

  18. Giving Women the Vote: Using Primary Source Documents to Teach about the Fight for Women's Suffrage.

    Science.gov (United States)

    Jacobsen, Margaret

    1988-01-01

    Presents a lesson in which students use primary sources to learn about the organizing strategies used in the fight for women's suffrage. These sources will provide insights into the past and help students develop appreciation for the hardships suffragists endured. Includes objectives, procedures, and suggestions for activities. (LS)

  19. Spatial Variation, Pollution Assessment and Source Identification of Major Nutrients in Surface Sediments of Nansi Lake, China

    Directory of Open Access Journals (Sweden)

    Longfeng Wang

    2017-06-01

    Full Text Available Nansi Lake has been seriously affected by intensive anthropogenic activities in recent years. In this study, an extensive survey on spatial variation, pollution assessment as well as the possible sources identification of major nutrients (Total phosphorus: TP, Total nitrogen: TN, and Total organic carbon: TOC in the surface sediments of Nansi Lake was conducted. Results showed that the mean contents of TP, TN and TOC were 1.13-, 5.40- and 2.50- fold higher than their background values respectively. Most of the TN and TOC contents in the surface sediments of Nansi Lake were four times as high or higher and twice as high or higher than the background values except the Zhaoyang sub-lake, and the spatial distribution of TN and TOC contents were remarkably similar over a large area. Nearly all the TP contents in the surface sediments of Nansi Lake were all higher than its background values except most part of the Zhaoyang sub-lake. Based on the enrichment factor (EF and the organic pollution evaluation index (Org-index, TP, TOC and TN showed minor enrichment (1.13, minor enrichment (2.50 and moderately severe enrichment (5.40, respectively, and most part of the Dushan sub-lake and the vicinity of the Weishan island were in moderate or heavy sediments organic pollution, while the other parts were clean. Moreover, according to the results of multivariate statistical analysis, we deduced that anthropogenic TN and TOC were mainly came from industrial sources including enterprises distributed in Jining, Yanzhou and Zoucheng along with iron and steel industries distributed in the southern of the Weishan sub-lake, whereas TP mainly originated from runoff and soil erosion coming from agricultural lands located in Heze city and Weishan island, the local aquacultural activities as well as the domestic sewage discharge of Jining city.

  20. Tropical Fruits and Nectars Typically Consumed in Latino Communities Are Excellent Sources of Vitamins A, C, and Other Nutrients

    Science.gov (United States)

    Latinos are the largest minority group in the U.S. The Nutrient Data Laboratory (NDL) is sampling and analyzing foods commonly consumed by Latin Americans in order to improve the quality and quantity of data on ethnic foods in the USDA National Nutrient Database for Standard Reference. Guanabana, gu...

  1. Primary sources of PM2.5 organic aerosol in an industrial Mediterranean city, Marseille

    Science.gov (United States)

    El Haddad, I.; Marchand, N.; Wortham, H.; Piot, C.; Besombes, J.-L.; Cozic, J.; Chauvel, C.; Armengaud, A.; Robin, D.; Jaffrezo, J.-L.

    2011-03-01

    Marseille, the most important port of the Mediterranean Sea, represents a challenging case study for source apportionment exercises, combining an active photochemistry and multiple emission sources, including fugitive emissions from industrial sources and shipping. This paper presents a Chemical Mass Balance (CMB) approach based on organic markers and metals to apportion the primary sources of organic aerosol in Marseille, with a special focus on industrial emissions. Overall, the CMB model accounts for the major primary anthropogenic sources including motor vehicles, biomass burning and the aggregate emissions from three industrial processes (heavy fuel oil combustion/shipping, coke production and steel manufacturing) as well as some primary biogenic emissions. This source apportionment exercise is well corroborated by 14C measurements. Primary OC estimated by the CMB accounts on average for 22% of total OC and is dominated by the vehicular emissions that contribute on average for 17% of OC mass concentration (vehicular PM contributes for 17% of PM2.5). Even though industrial emissions contribute only 2.3% of the total OC (7% of PM2.5), they are associated with ultrafine particles (Dpheavy metals such as Pb, Ni and V. On one hand, given that industrial emissions governed key primary markers, their omission would lead to substantial uncertainties in the CMB analysis performed in areas heavily impacted by such sources, hindering accurate estimation of non-industrial primary sources and secondary sources. On the other hand, being associated with bursts of submicron particles and carcinogenic and mutagenic components such as PAH, these emissions are most likely related with acute ill-health outcomes and should be regulated despite their small contributions to OC. Another important result is the fact that 78% of OC mass cannot be attributed to the major primary sources and, thus, remains un-apportioned. We have consequently critically investigated the uncertainties

  2. Agronomic efficiency of potassium fertilization in lettuce fertilized with alternative nutrient sources Eficiência agronômica da adubação potássica na alface adubada com fontes alternativas de nutrientes

    Directory of Open Access Journals (Sweden)

    Douglas Ramos Guelfi-Silva

    2013-06-01

    Full Text Available The aim of this study was to evaluate the effect of alternative sources of nutrients on the nutrition, yield and efficiency of potassium fertilization in lettuce. The experiment was carried out in a greenhouse, using 3.7 kg pots filled with a dystrophic red-yellow Latosol of medium texture. The experimental design was randomized, with treatments divided into a 4 x 6 factorial: four doses of potassium (0; 200; 400; 600 kg ha-1 K2O and six alternative sources of nutrients (breccia, ultramafic, biotite schist, phlogopite, and mining and Chapada by-products, with four replications. Content and accumulation were determined for potassium (K, copper (Cu, zinc (Zn and nickel (Ni in the lettuce shoots, and from these data two indices were calculated for the efficiency of potassium as a fertilizer. The application of increasing values of alternative sources of nutrients promoted improvements in nutrition and increases in lettuce yield. The efficiency of potassium fertilization decreased with the increase in values of potassium taken from alternative nutrient sources, with the mining by-products and the ultramafic being superior to the other sources. Crushed silicate rocks and mining by-products can therefore both be used as fertilizer in organic and conventional production systems.O objetivo desse estudo foi avaliar o efeito da aplicação de fontes alternativas de nutrientes na nutrição, produção e eficiência da adubação potássica na alface. O experimento foi conduzido em casa de vegetação, em vasos com 3,7 kg preenchidos com um Latossolo Vermelho Amarelo distrófico de textura média. O delineamento experimental foi inteiramente casualizado e os tratamentos foram distribuídos em arranjo fatorial 4 x 6, sendo quatro doses de potássio (0; 200; 400; 600 kg ha-1 de K2O e seis fontes alternativas de nutrientes (brecha, ultramáfica, biotita xisto, flogopitito, subproduto de mineração e subproduto de chapada, com quatro repetições. Foram

  3. Food Sources of Total Energy and Nutrients among U.S. Infants and Toddlers: National Health and Nutrition Examination Survey 2005–2012

    Directory of Open Access Journals (Sweden)

    Carley A. Grimes

    2015-08-01

    Full Text Available Understanding the dietary intakes of infants and toddlers is important because early life nutrition influences future health outcomes. The aim of this study was to determine the dietary sources of total energy and 16 nutrients in a nationally representative sample of U.S. infants and toddlers aged 0–24 months. Data from the 2005–2012 National Health and Nutrition Examination Survey were analyzed. Dietary intake was assessed in 2740 subjects using one 24-h dietary recall. The population proportion was used to determine the contribution of foods and beverages to nutrient intakes. Overall infant formulas and baby foods were the leading sources of total energy and nutrients in infants aged 0–11.9 months. In toddlers, the diversity of food groups contributing to nutrient intakes was much greater. Important sources of total energy included milk, 100% juice and grain based mixed dishes. A number of foods of low nutritional quality also contributed to energy intakes including sweet bakery products, sugar-sweetened beverages and savory snacks. Overall non-flavored milks and ready-to-eat cereals were the most important contributors to micronutrient intakes. In conclusion this information can be used to guide parents regarding appropriate food selection as well as inform targeted dietary strategies within public health initiatives to improve the diets of infants and toddlers.

  4. Food Sources of Total Energy and Nutrients among U.S. Infants and Toddlers: National Health and Nutrition Examination Survey 2005-2012.

    Science.gov (United States)

    Grimes, Carley A; Szymlek-Gay, Ewa A; Campbell, Karen J; Nicklas, Theresa A

    2015-08-14

    Understanding the dietary intakes of infants and toddlers is important because early life nutrition influences future health outcomes. The aim of this study was to determine the dietary sources of total energy and 16 nutrients in a nationally representative sample of U.S. infants and toddlers aged 0-24 months. Data from the 2005-2012 National Health and Nutrition Examination Survey were analyzed. Dietary intake was assessed in 2740 subjects using one 24-h dietary recall. The population proportion was used to determine the contribution of foods and beverages to nutrient intakes. Overall infant formulas and baby foods were the leading sources of total energy and nutrients in infants aged 0-11.9 months. In toddlers, the diversity of food groups contributing to nutrient intakes was much greater. Important sources of total energy included milk, 100% juice and grain based mixed dishes. A number of foods of low nutritional quality also contributed to energy intakes including sweet bakery products, sugar-sweetened beverages and savory snacks. Overall non-flavored milks and ready-to-eat cereals were the most important contributors to micronutrient intakes. In conclusion this information can be used to guide parents regarding appropriate food selection as well as inform targeted dietary strategies within public health initiatives to improve the diets of infants and toddlers.

  5. Design study of primary ion provider for relativistic heavy ion collider electron beam ion source.

    Science.gov (United States)

    Kondo, K; Kanesue, T; Tamura, J; Okamura, M

    2010-02-01

    Brookhaven National Laboratory has developed the new preinjector system, electron beam ion source (EBIS) for relativistic heavy ion collider (RHIC) and National Aeronautics and Space Administration Space Radiation Laboratory. Design of primary ion provider is an essential problem since it is required to supply beams with different ion species to multiple users simultaneously. The laser ion source with a defocused laser can provide a low charge state and low emittance ion beam, and is a candidate for the primary ion source for RHIC-EBIS. We show a suitable design with appropriate drift length and solenoid, which helps to keep sufficient total charge number with longer pulse length. The whole design of primary ion source, as well as optics arrangement, solid targets configuration and heating about target, is presented.

  6. 18 CFR 2.400 - Statement of interpretation of waste concerning natural gas as the primary energy source for...

    Science.gov (United States)

    2010-04-01

    ... interpretation of waste concerning natural gas as the primary energy source for qualifying small power production... concerning natural gas as the primary energy source for qualifying small power production facilities. For purposes of deciding whether natural gas may be considered as waste as the primary energy source pursuant...

  7. Acclimation of Emiliania huxleyi (1516) to nutrient limitation involves precise modification of the proteome to scavenge alternative sources of N and P.

    Science.gov (United States)

    McKew, Boyd A; Metodieva, Gergana; Raines, Christine A; Metodiev, Metodi V; Geider, Richard J

    2015-10-01

    Limitation of marine primary production by the availability of nitrogen or phosphorus is common. Emiliania huxleyi, a ubiquitous phytoplankter that plays key roles in primary production, calcium carbonate precipitation and production of dimethyl sulfide, often blooms in mid-latitude at the beginning of summer when inorganic nutrient concentrations are low. To understand physiological mechanisms that allow such blooms, we examined how the proteome of E. huxleyi (strain 1516) responds to N and P limitation. We observed modest changes in much of the proteome despite large physiological changes (e.g. cellular biomass, C, N and P) associated with nutrient limitation of growth rate. Acclimation to nutrient limitation did however involve significant increases in the abundance of transporters for ammonium and nitrate under N limitation and for phosphate under P limitation. More notable were large increases in proteins involved in the acquisition of organic forms of N and P, including urea and amino acid/polyamine transporters and numerous C-N hydrolases under N limitation and a large upregulation of alkaline phosphatase under P limitation. This highly targeted reorganization of the proteome towards scavenging organic forms of macronutrients gives unique insight into the molecular mechanisms that underpin how E. huxleyi has found its niche to bloom in surface waters depleted of inorganic nutrients. © 2015 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  8. Common Prairie feeds with different soluble and insoluble fractions used for CPM diet formulation in dairy cattle: Impact of carbohydrate-protein matrix structure on protein and other primary nutrient digestion

    Science.gov (United States)

    Peng, Quanhui; Wang, Zhisheng; Zhang, Xuewei; Yu, Peiqiang

    2014-03-01

    An experiment was conducted to investigate the relationship of carbohydrates molecular spectral characteristics to rumen degradability of primary nutrients in Prairie feeds in dairy cattle. In total, 12 different types of feeds were selected, each type of feed was from three different source with total 37 samples. Six types of them were energy-sourced feeds and the others were protein-sourced feeds. The carbohydrates molecular spectral intensity of various functional groups were collected using Fourier transform infrared attenuated total reflectance (ATR-FT/IR) spectroscopy. In the in situ study, the results showed that the rumen digestibility and digestible fractions of primary nutrients (DM, OM, NCP, and CP) were significantly different (P digestibility and digestible fractions of DM, OM and NCP. Spectral intensities of H_1150, H_1015, A_1, and A_3 were weakly negatively associated with in situ rumen degradation of CP. Spectral intensities of A_1240 and H_1240, mainly associated with cellulosic compounds, were correlated with rumen CP degradation. The multiple regression analysis demonstrated that the spectral intensities of A_3 and H_1415 played the most important role and could be used as a potential tool to predict rumen protein degradation of feeds in dairy cattle. In conclusion, this study showed that the carbohydrates as a whole have an effect on protein rumen degradation, rather than cellulose alone, indicating carbohydrate-protein matrix structure impact protein utilization in dairy cattle. The non-invasive molecular spectral technique (ATR-FT/IR) could be used as a rapid potential tool to predict rumen protein degradation of feedstuffs by using molecular spectral bands intensities in carbohydrate fingerprint region.

  9. Common Prairie feeds with different soluble and insoluble fractions used for CPM diet formulation in dairy cattle: impact of carbohydrate-protein matrix structure on protein and other primary nutrient digestion.

    Science.gov (United States)

    Peng, Quanhui; Wang, Zhisheng; Zhang, Xuewei; Yu, Peiqiang

    2014-01-01

    An experiment was conducted to investigate the relationship of carbohydrates molecular spectral characteristics to rumen degradability of primary nutrients in Prairie feeds in dairy cattle. In total, 12 different types of feeds were selected, each type of feed was from three different source with total 37 samples. Six types of them were energy-sourced feeds and the others were protein-sourced feeds. The carbohydrates molecular spectral intensity of various functional groups were collected using Fourier transform infrared attenuated total reflectance (ATR-FT/IR) spectroscopy. In the in situ study, the results showed that the rumen digestibility and digestible fractions of primary nutrients (DM, OM, NCP, and CP) were significantly different (P<0.05) among the feeds. The spectral bands features were significantly different (P<0.05) among the feeds. Spectral intensities of A_Cell, H_1415 and H_1370 were weakly positively correlated with in situ rumen digestibility and digestible fractions of DM, OM and NCP. Spectral intensities of H_1150, H_1015, A_1, and A_3 were weakly negatively associated with in situ rumen degradation of CP. Spectral intensities of A_1240 and H_1240, mainly associated with cellulosic compounds, were correlated with rumen CP degradation. The multiple regression analysis demonstrated that the spectral intensities of A_3 and H_1415 played the most important role and could be used as a potential tool to predict rumen protein degradation of feeds in dairy cattle. In conclusion, this study showed that the carbohydrates as a whole have an effect on protein rumen degradation, rather than cellulose alone, indicating carbohydrate-protein matrix structure impact protein utilization in dairy cattle. The non-invasive molecular spectral technique (ATR-FT/IR) could be used as a rapid potential tool to predict rumen protein degradation of feedstuffs by using molecular spectral bands intensities in carbohydrate fingerprint region. Copyright © 2013 Elsevier B

  10. Response-based selection of barley cultivars and legume species for complementarity: Root morphology and exudation in relation to nutrient source.

    Science.gov (United States)

    Giles, Courtney D; Brown, Lawrie K; Adu, Michael O; Mezeli, Malika M; Sandral, Graeme A; Simpson, Richard J; Wendler, Renate; Shand, Charles A; Menezes-Blackburn, Daniel; Darch, Tegan; Stutter, Marc I; Lumsdon, David G; Zhang, Hao; Blackwell, Martin S A; Wearing, Catherine; Cooper, Patricia; Haygarth, Philip M; George, Timothy S

    2017-02-01

    Phosphorus (P) and nitrogen (N) use efficiency may be improved through increased biodiversity in agroecosystems. Phenotypic variation in plants' response to nutrient deficiency may influence positive complementarity in intercropping systems. A multicomponent screening approach was used to assess the influence of P supply and N source on the phenotypic plasticity of nutrient foraging traits in barley (H. vulgare L.) and legume species. Root morphology and exudation were determined in six plant nutrient treatments. A clear divergence in the response of barley and legumes to the nutrient treatments was observed. Root morphology varied most among legumes, whereas exudate citrate and phytase activity were most variable in barley. Changes in root morphology were minimized in plants provided with ammonium in comparison to nitrate but increased under P deficiency. Exudate phytase activity and pH varied with legume species, whereas citrate efflux, specific root length, and root diameter lengths were more variable among barley cultivars. Three legume species and four barley cultivars were identified as the most responsive to P deficiency and the most contrasting of the cultivars and species tested. Phenotypic response to nutrient availability may be a promising approach for the selection of plant combinations for minimal input cropping systems. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Stress sources and manifestations in a nation-wide sample of pre-primary, primary and secondary educators in Greece

    Directory of Open Access Journals (Sweden)

    Nadia eKourmousi

    2016-04-01

    Full Text Available BackgroundTeachers experience high levels of stress as a result of their professional duties and research has shown a growing interest in this phenomenon during the recent years. Aim of this study was to explore the associations of stress sources and manifestations with individual and job-related characteristics in educators of all levels. MethodsIn a cross–sectional design, following an informative e-campaign on the study aims through the official and the main teachers’ portals in Greece, respondents completed online the Teachers Stress Inventory (TSI and the 14-item Perceived Stress Scale (PSS-14. 974 male and 2473 female pre-primary, primary and secondary educators with a mean age of 41.2 years responded. ResultsWomen and younger teachers reported significantly higher levels of stress, mainly due to lack of time and other work-related stressors, and also more emotional and gastronomic manifestations. Increased age and working experience were associated with lower levels of several stress sources. Teachers of administrative positions had increased time management stressors, but less professional distress, professional investment and discipline and motivation stressors. Additionally, working and residing far from family increased teachers’ stress levels associated to control, motivation and investment. Teachers of pre-primary education had reduced professional investment and motivation stress factors while vocational lyceum teachers of secondary education reported less work-related stressors and manifestations and more discipline and motivation related ones. Having students supported or in need of support from special educators and students with difficulties in speaking or comprehension was associated with most of the teachers' stress sources and manifestations (i.e. TSI subscales. Finally, colleagues’ and mainly supervisors' support seemed to provide a strong and consistent protection against both stress sources and manifestations

  12. Stress Sources and Manifestations in a Nationwide Sample of Pre-Primary, Primary, and Secondary Educators in Greece.

    Science.gov (United States)

    Kourmousi, Ntina; Alexopoulos, Evangelos C

    2016-01-01

    Teachers experience high levels of stress as a result of their professional duties, and research has shown a growing interest in this phenomenon during the recent years. Aim of this study was to explore the associations of stress sources and manifestations with individual and job-related characteristics in educators of all levels. In a cross-sectional design, following an informative e-campaign on the study aims through the official and the main teachers' portals in Greece, respondents completed online the teachers stress inventory (TSI) and the 14-item Perceived Stress Scale. Nine hundred seventy-four male and 2473 female pre-primary, primary, and secondary educators with a mean age of 41.2 years responded. Women and younger teachers reported significantly higher levels of stress, mainly due to lack of time and other work-related stressors, and also more emotional and gastronomic manifestations. Increased age and working experience were associated with lower levels of several stress sources. Teachers of administrative positions had increased time management stressors, but less professional distress, professional investment, and discipline and motivation stressors. Additionally, working and residing far from family increased teachers' stress levels associated with control, motivation, and investment. Teachers of pre-primary education had reduced professional investment and motivation stress factors, while vocational lyceum teachers of secondary education reported less work-related stressors and manifestations and more discipline and motivation-related ones. Having students supported or in need of support from special educators and students with difficulties in speaking or comprehension was associated with most of the teachers' stress sources and manifestations (i.e., TSI subscales). Finally, colleagues' and mainly supervisors' support seemed to provide a strong and consistent protection against both stress sources and manifestations. Stress factors and

  13. Host-Derived Sialic Acids Are an Important Nutrient Source Required for Optimal Bacterial Fitness In Vivo

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    Nathan D. McDonald

    2016-04-01

    Full Text Available A major challenge facing bacterial intestinal pathogens is competition for nutrient sources with the host microbiota. Vibrio cholerae is an intestinal pathogen that causes cholera, which affects millions each year; however, our knowledge of its nutritional requirements in the intestinal milieu is limited. In this study, we demonstrated that V. cholerae can grow efficiently on intestinal mucus and its component sialic acids and that a tripartite ATP-independent periplasmic SiaPQM strain, transporter-deficient mutant NC1777, was attenuated for colonization using a streptomycin-pretreated adult mouse model. In in vivo competition assays, NC1777 was significantly outcompeted for up to 3 days postinfection. NC1777 was also significantly outcompeted in in vitro competition assays in M9 minimal medium supplemented with intestinal mucus, indicating that sialic acid uptake is essential for fitness. Phylogenetic analyses demonstrated that the ability to utilize sialic acid was distributed among 452 bacterial species from eight phyla. The majority of species belonged to four phyla, Actinobacteria (members of Actinobacillus, Corynebacterium, Mycoplasma, and Streptomyces, Bacteroidetes (mainly Bacteroides, Capnocytophaga, and Prevotella, Firmicutes (members of Streptococcus, Staphylococcus, Clostridium, and Lactobacillus, and Proteobacteria (including Escherichia, Shigella, Salmonella, Citrobacter, Haemophilus, Klebsiella, Pasteurella, Photobacterium, Vibrio, and Yersinia species, mostly commensals and/or pathogens. Overall, our data demonstrate that the ability to take up host-derived sugars and sialic acid specifically allows V. cholerae a competitive advantage in intestinal colonization and that this is a trait that is sporadic in its occurrence and phylogenetic distribution and ancestral in some genera but horizontally acquired in others.

  14. Source contributions and regional transport of primary particulate matter in China

    International Nuclear Information System (INIS)

    Hu, Jianlin; Wu, Li; Zheng, Bo; Zhang, Qiang; He, Kebin; Chang, Qing; Li, Xinghua; Yang, Fumo; Ying, Qi; Zhang, Hongliang

    2015-01-01

    A source-oriented CMAQ was applied to determine source sector/region contributions to primary particulate matter (PPM) in China. Four months were simulated with emissions grouped to eight regions and six sectors. Predicted elemental carbon (EC), primary organic carbon (POC), and PPM concentrations and source contributions agree with measurements and have significant spatiotemporal variations. Residential is a major contributor to spring/winter EC (50–80%), POC (60%–90%), and PPM (30–70%). For summer/fall, industrial contributes 30–50% for EC/POC and 40–60% for PPM. Transportation is more important for EC (20–30%) than POC/PPM ( 90% in Beijing. - Highlights: • A source-oriented CMAQ was established for primary particulate matter (PPM). • Source and region contributions to EC, POC and PPM in China were quantified. • Residential is major in spring/winter and industrial dominates in summer/fall. • Open burning is more important for southern while dust is in contrast. • Both local and Heibei emissions contribute to PPM in Beijing. - Source and region contributions to primary particulate matter in China were quantified for four months during 2012-2013. Residential and industrial are the major contributors.

  15. Identification of the sources of primary organic aerosols at urban schools: A molecular marker approach

    International Nuclear Information System (INIS)

    Crilley, Leigh R.; Qadir, Raeed M.; Ayoko, Godwin A.; Schnelle-Kreis, Jürgen; Abbaszade, Gülcin; Orasche, Jürgen; Zimmermann, Ralf; Morawska, Lidia

    2014-01-01

    Children are particularly susceptible to air pollution and schools are examples of urban microenvironments that can account for a large portion of children's exposure to airborne particles. Thus this paper aimed to determine the sources of primary airborne particles that children are exposed to at school by analyzing selected organic molecular markers at 11 urban schools in Brisbane, Australia. Positive matrix factorization analysis identified four sources at the schools: vehicle emissions, biomass burning, meat cooking and plant wax emissions accounting for 45%, 29%, 16% and 7%, of the organic carbon respectively. Biomass burning peaked in winter due to prescribed burning of bushland around Brisbane. Overall, the results indicated that both local (traffic) and regional (biomass burning) sources of primary organic aerosols influence the levels of ambient particles that children are exposed at the schools. These results have implications for potential control strategies for mitigating exposure at schools. - Highlights: • Selected organic molecular markers at 11 urban schools were analyzed. • Four sources of primary organic aerosols were identified by PMF at the schools. • Both local and regional sources were found to influence exposure at the schools. • The results have implications for mitigation of children's exposure at schools. - The identification of the most important sources of primary organic aerosols at urban schools has implications for control strategies for mitigating children's exposure at schools

  16. Source Apportionment of Primary and Secondary Fine Particulate Matter in China

    Science.gov (United States)

    Hu, J.; Zhang, H.; Ying, Q.

    2015-12-01

    In the past few decades, China have been facing extreme particulate matter (PM) pollution problems due to the combination of fast increase of population, industrialization, urbanization and associated energy consumption and lagging of sufficient emission control measures. Studies have identified the major components of fine PM (PM2.5) in China include primary PM (which is directly emitted into the atmosphere), sulfate and nitrate (which are mainly secondary PM, i.e., formed from gaseous precursors), and organic aerosols (which can be primary or secondary). Contributions of different source sectors to the different PM components are substantially different; therefore source apportionment of these components can provide critical information needed for policy makers to design effective emission control strategies. In the current study, a source-oriented version of the Community Multiscale Air Quality (CMAQ) model that directly tracks the contributions from multiple emission sources to primary and secondary PM2.5 is developed, and then applied to determine the regional contributions of power, industry, transportation and residential sectors to primary PM, nitrate and sulfate concentrations in China. Four months in 2012-2013 are simulated to predict the seasonal variations of source contributions. Model predictions are evaluated with ambient measured concentrations. The source-oriented CMAQ model is capable of reproducing most of the available PM10 and PM2.5 mass, and PM2.5 EC, POC, nitrate and sulfate observations. Predicted source contributions for EC also generally agree with to the source contributions estimated by receptor models reported in previous studies. Model predictions suggest residential is a major contributor to primary PM (30-70%) in the spring and winter, and industrial contributes 40-60% of primary PM in the summer and fall; Transportation is an important source for EC (20-30%); Power sector is the dominating source of nitrate and sulfate in both

  17. An RF ion source based primary ion gun for secondary ion mass spectroscopy

    International Nuclear Information System (INIS)

    Menon, Ranjini; Nabhiraj, P.Y.; Bhandari, R.K.

    2011-01-01

    In this article we present the design, development and characterization of an RF plasma based ion gun as a primary ion gun for SIMS application. RF ion sources, in particular Inductively Coupled Plasma (ICP) ion sources are superior compared to LMIS and duoplasmtron ion sources since they are filamentless, can produce ions of gaseous elements. At the same time, ICP ion sources offer high angular current density which is an important factor in producing high current in small spot size on the target. These high current microprobes improve the signal to noise ratio by three orders as compared to low current ion sources such as LMIS. In addition, the high current microprobes have higher surface and depth profiling speeds. In this article we describe a simple ion source in its very basic form, two lens optical column and characteristics of microprobe

  18. Development of the Dutch primary standard for beta-emitting brachytherapy sources

    International Nuclear Information System (INIS)

    Marel, J. an der; Dijk, E. van

    2002-01-01

    The application of β-radiation emitting radioactive sources in medicine is rapidly expanding. An important new application is the use of β-radiation emitting radioactive sources in endovascular brachytherapy to avoid restenosis. Another well-known application is the use of the ophthalmic applicator (flat or concave surface source) for the treatment of tumors in the eye. Dose and dose distributions are very important characteristics of brachytherapy sources. The absorbed dose in the treated tissue should be known accurately to assure a good quality of the treatment and to develop new treatment methods and source configurations. At the Nederland s Meetinstituut (NMi) a project is going on for the development of a primary standard for betadosimetry. With this standard, dose and dose distributions of β-sources as used in brachytherapy can be measured in terms of absorbed dose to water. The primary standard is based on an extrapolation chamber. The extrapolation chamber will become part of a quality assurance system in Dutch hospitals for endovascular brachytherapy sources. The quality assurance system will further consist of transfer standards like well-type ionisation chambers, plastic scintillator systems and radiochromic film dosimetry. Apart from the endovascular sources the extrapolation chamber will be used to characterize ophthalmic applicators

  19. Host-Derived Sialic Acids Are an Important Nutrient Source Required for Optimal Bacterial Fitness In Vivo.

    Science.gov (United States)

    McDonald, Nathan D; Lubin, Jean-Bernard; Chowdhury, Nityananda; Boyd, E Fidelma

    2016-04-12

    A major challenge facing bacterial intestinal pathogens is competition for nutrient sources with the host microbiota.Vibrio cholerae is an intestinal pathogen that causes cholera, which affects millions each year; however, our knowledge of its nutritional requirements in the intestinal milieu is limited. In this study, we demonstrated that V. cholerae can grow efficiently on intestinal mucus and its component sialic acids and that a tripartite ATP-independent periplasmic SiaPQM strain, transporter-deficient mutant NC1777, was attenuated for colonization using a streptomycin-pretreated adult mouse model. In in vivo competition assays, NC1777 was significantly outcompeted for up to 3 days postinfection. NC1777 was also significantly outcompeted in in vitro competition assays in M9 minimal medium supplemented with intestinal mucus, indicating that sialic acid uptake is essential for fitness. Phylogenetic analyses demonstrated that the ability to utilize sialic acid was distributed among 452 bacterial species from eight phyla. The majority of species belonged to four phyla, Actinobacteria (members of Actinobacillus, Corynebacterium, Mycoplasma, and Streptomyces), Bacteroidetes (mainly Bacteroides, Capnocytophaga, and Prevotella), Firmicutes (members of Streptococcus, Staphylococcus, Clostridium, and Lactobacillus), and Proteobacteria (including Escherichia, Shigella, Salmonella, Citrobacter, Haemophilus, Klebsiella, Pasteurella, Photobacterium, Vibrio, and Yersinia species), mostly commensals and/or pathogens. Overall, our data demonstrate that the ability to take up host-derived sugars and sialic acid specifically allows V. cholerae a competitive advantage in intestinal colonization and that this is a trait that is sporadic in its occurrence and phylogenetic distribution and ancestral in some genera but horizontally acquired in others. Sialic acids are nine carbon amino sugars that are abundant on all mucous surfaces. The deadly human pathogen Vibrio cholerae contains

  20. Agricultural production - Phase 2. Indonesia. Sources and sinks of nitrogen-E phosphorus-based nutrients in cropping systems

    International Nuclear Information System (INIS)

    Wetselaar, R.I.

    1992-01-01

    This document is the report of an expert mission to assist in the initiation of research on sustainable agriculture in rice-based cropping systems as related to the flow of plant nutrients, and on the use of legumes in upland cropping systems. Experimental suggestions include an investigation of the acid tolerance of different soybean strains under upland conditions, an analysis of ways to replace fertilizer nitrogen for rice crops by a green manure such as azolla, and a study of the increase in nutrient availability due to th presence of fish in a paddy field

  1. Analysis of the primary source term for meltdown accidents using MELCOR 1.8.2

    International Nuclear Information System (INIS)

    Schmuck, P.

    1995-01-01

    The MELCOR code describing accident phenomena in the core and primary systems was used for source term calculations and - in the context of the MELCOR Cooperative Assessment Programme - for studying two-phase flows through components such as valves and chokes. Results of the latter studies in comparison to experiments gave hints for an improved calculation of momentum transfer between the phases. (orig.)

  2. The Baghdad that Was: Using Primary Sources to Teach World History

    Science.gov (United States)

    Schur, Joan Brodsky

    2009-01-01

    That primary source documents have the power to bring the past alive is no news to social studies teachers. What is new in the last 10 years is the number of digitized documents available online that teachers can download and use in their classrooms. Encouraging teachers to utilize this ever-increasing treasure trove of resources was the goal of…

  3. The Pedagogy of Primary Historical Sources in Mathematics: Classroom Practice Meets Theoretical Frameworks

    Science.gov (United States)

    Barnett, Janet Heine; Lodder, Jerry; Pengelley, David

    2014-01-01

    We analyze our method of teaching with primary historical sources within the context of theoretical frameworks for the role of history in teaching mathematics developed by Barbin, Fried, Jahnke, Jankvist, and Kjeldsen and Blomhøj, and more generally from the perspective of Sfard's theory of learning as communication. We present case studies…

  4. Primary Sources: America's Teachers on Teaching in an Era of Change. Third Edition

    Science.gov (United States)

    Scholastic Inc. and the Bill & Melinda Gates Foundation, 2013

    2013-01-01

    This third edition of "Primary Sources" represents a joint project of Scholastic and the Bill & Melinda Gates Foundation. It reports the views of more than 20,000 public school teachers on important issues related to their profession. Fielded in July 2013, the survey asks teachers about their motivation, new learning standards,…

  5. Spatial and temporal shifts in gross primary productivity, respiration, and nutrient concentrations in urban streams impacted by wastewater treatment plant effluent

    Science.gov (United States)

    Ledford, S. H.; Toran, L.

    2017-12-01

    Impacts of wastewater treatment plant effluent on nutrient retention and stream productivity are highly varied. The working theory has been that large pulses of nutrients from plants may hinder in-stream nutrient retention. We evaluated nitrate, total dissolved phosphorus, and dissolved oxygen in Wissahickon Creek, an urban third-order stream in Montgomery and Philadelphia counties, PA, that receives effluent from four wastewater treatment plants. Wastewater treatment plant effluent had nitrate concentrations of 15-30 mg N/L and total dissolved phosphorus of 0.3 to 1.8 mg/L. Seasonal longitudinal water quality samples showed nitrate concentrations were highest in the fall, peaking at 22 mg N/L, due to low baseflow, but total dissolved phosphorous concentrations were highest in the spring, reaching 0.6 mg/L. Diurnal dissolved oxygen patterns above and below one of the treatment plants provided estimates of gross primary productivity (GPP) and ecosystem respiration (ER). A site 1 km below effluent discharge had higher GPP in April (80 g O2 m-2 d-1) than the site above the plant (28 g O2 m-2 d-1). The pulse in productivity did not continue downstream, as the site 3 km below the plant had GPP of only 12 g O2 m-2 d-1. Productivity fell in June to 1-2 g O2 m-2 d-1 and the differences in productivity above and below plants were minimal. Ecosystem respiration followed a similar pattern in April, increasing from -17 g O2 m-2 d-1 above the plant to -47 g O2 m-2 d-1 1 km below the plant, then decreasing to -8 g O2 m-2 d-1 3 km below the plant. Respiration dropped to -3 g O2 m-2 d-1 above the plant in June but only fell to -9 to -10 g O2 m-2 d-1 at the two downstream sites. These findings indicate that large nutrient pulses from wastewater treatment plants spur productivity and respiration, but that these increases may be strongly seasonally dependent. Examining in-stream productivity and respiration is critical in wastewater impacted streams to understanding the seasonal and

  6. High-frequency monitoring reveals nutrient sources and transport processes in an agriculture-dominated lowland water system

    NARCIS (Netherlands)

    Grift, B. van der; Broers, H.P.; Berendrecht, W.; Rozemeijer, J.; Osté, L.; Griffioen, J.

    2016-01-01

    Many agriculture-dominated lowland water systems worldwide suffer from eutrophication caused by high nutrient loads. Insight in the hydrochemical functioning of embanked polder catchments is highly relevant for improving the water quality in such areas or for reducing export loads to downstream

  7. Comparison of aerobically-treated and untreated crop residue as a source of recycled nutrients in a recirculating hydroponic system

    Science.gov (United States)

    Mackowiak, C. L.; Garland, J. L.; Strayer, R. F.; Finger, B. W.; Wheeler, R. M.

    1996-01-01

    This study compared the growth of potato plants on nutrients recycled from inedible potato biomass. Plants were grown for 105 days in recirculating, thin-film hydroponic systems containing four separate nutrient solution treatments: (1) modified half-strength Hoagland's (control), 2) liquid effluent from a bioreactor containing inedible potato biomass, 3) filtered (0.2 micrometer) effluent, and 4) the water soluble fraction of inedible potato biomass (leachate). Approximately 50% of the total nutrient requirement in treatments 2-4 were provided (recycled) from the potato biomass. Leachate had an inhibitory effect on leaf conductance, photosynthetic rate, and growth (50% reduction in plant height and 60% reduction in tuber yield). Plants grown on bioreactor effluent (filtered or unfiltered) were similar to the control plants. These results indicated that rapidly degraded, water soluble organic material contained in the inedible biomass, i.e., material in leachate, brought about phytotoxicity in the hydroponic culture of potato. Recalcitrant, water soluble organic material accumulated in all nutrient recycling treatments (650% increase after 105 days), but no increase in rhizosphere microbial numbers was observed.

  8. Physical models and primary design of reactor based slow positron source at CMRR

    Science.gov (United States)

    Wang, Guanbo; Li, Rundong; Qian, Dazhi; Yang, Xin

    2018-07-01

    Slow positron facilities are widely used in material science. A high intensity slow positron source is now at the design stage based on the China Mianyang Research Reactor (CMRR). This paper describes the physical models and our primary design. We use different computer programs or mathematical formula to simulate different physical process, and validate them by proper experiments. Considering the feasibility, we propose a primary design, containing a cadmium shield, a honeycomb arranged W tubes assembly, electrical lenses, and a solenoid. It is planned to be vertically inserted in the Si-doping channel. And the beam intensity is expected to be 5 ×109

  9. Nutrient intakes, major food sources and dietary inadequacies of Inuit adults living in three remote communities in Nunavut, Canada.

    Science.gov (United States)

    Sharma, S; Hopping, B N; Roache, C; Sheehy, T

    2013-12-01

    Inuit in Nunavut, Canada, are currently undergoing a nutritional transition that may contribute to an increased prevalence of chronic disease. Information is lacking about the extent to which contemporary Inuit diets are meeting current dietary recommendations. A culturally appropriate quantitative food frequency questionnaire (QFFQ) developed and validated for Inuit in Nunavut, Canada, was used to assess food and nutrient intake in a cross-sectional sample of adults. Participants included 175 women and 36 men with mean (SD) ages of 42.4 (13.2) and 42.1 (15.0) years, respectively. The response rate for those who completed the study was 79% with 208 QFFQs included for analysis. Reported mean daily energy intakes were: men 15,171 kJ (3626 kcal); women 11,593 kJ (2771 kcal). Dietary inadequacy was expressed as the percentage of participants reporting intakes below the sex- and age-specific estimated average requirements (EARs). For nutrients without EARs, adequate intakes were used. Energy and sodium intakes exceeded the recommendations. Less than 10% of participants met recommendations for dietary fibre intake. Vitamin E intakes were below EARs for ≥97% of participants, whereas >20% reported inadequate vitamin A, folate and magnesium intakes. Among women, >50% reported inadequate calcium and vitamin D intakes. Non-nutrient-dense foods contributed 30% of energy, 73% of sugars and 22% of fat. Traditional foods contributed 56% of protein and 49% of iron. The present study demonstrates a relatively high prevalence of inadequate nutrient intakes among Inuit. The results may be used to monitor the nutrition transition among Inuit, evaluate nutritional interventions, and inform public health policy decision-making. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

  10. River export of nutrients to the coastal waters of China: the MARINA model to assess sources, effects and solutions

    OpenAIRE

    Strokal, Maryna

    2016-01-01

    Rivers export increasing amounts of nitrogen (N) and phosphorus (P) to the coastal waters of China. This causes eutrophication problems that can damage living organisms when oxygen levels drop and threaten human health through toxic algae. We know that these problems result from human activities on land such as agriculture and urbanization. However, the relative importance of these human activities for river export of nutrients to Chinese seas is not well studied. There are two important issu...

  11. Designing display primaries with currently available light sources for UHDTV wide-gamut system colorimetry.

    Science.gov (United States)

    Masaoka, Kenichiro; Nishida, Yukihiro; Sugawara, Masayuki

    2014-08-11

    The wide-gamut system colorimetry has been standardized for ultra-high definition television (UHDTV). The chromaticities of the primaries are designed to lie on the spectral locus to cover major standard system colorimetries and real object colors. Although monochromatic light sources are required for a display to perfectly fulfill the system colorimetry, highly saturated emission colors using recent quantum dot technology may effectively achieve the wide gamut. This paper presents simulation results on the chromaticities of highly saturated non-monochromatic light sources and gamut coverage of real object colors to be considered in designing wide-gamut displays with color filters for the UHDTV.

  12. Safety Analysis Report for Primary Capsule of Ir-192 Radiation Source

    International Nuclear Information System (INIS)

    Lee, J. C.; Bang, K. S.; Choi, W. S.; Seo, K. S.; Son, K. J.; Park, W. J.

    2008-12-01

    All of the source capsules to transport a special form radioactive material should be designed and fabricated in accordance with the design criteria prescribed in IAEA standards and domestic regulations. The objective of this project is to prove the safety of a primary capsule for Ir-192 radiation source which produced in the HANARO. The safety tests of primary capsules were carried out for the impact, percussion and heat conditions. And leakage tests were carried out before and after the each tests. The capsule showed slight scratches and their deformations were not found after each tests. It also met the allowable limits of leakage rate after each test. Therefore, it has been verified that the capsule was designed and fabricated to meet all requirements for the special form radioactive materials

  13. Measurement and calculation of radiation sources in the primary cooling system of JOYO

    International Nuclear Information System (INIS)

    Suzuki, S.; Iizawa, K.; Ohtani, N.; Kobayashi, T.; Horie, J.; Handa, H.

    1987-01-01

    Production and transfer of radiation sources in the primary cooling system are important consideration in the LMFBR plant from the viewpoint of radiation protection and shielding design. These items were evaluated with calculations and/or measurements in the Japanese experimental fast reactor JOYO. In this study, calculations were made with the DOT3.5 0 two-dimensional discrete ordinate transport code to determine the neutron flux and production rate distributions of radiation sources in the reactor vessel. Using the DOT results, the behavior in primary coolant sodium of the CP (radioactive corrosion products) which were released from the reactor structural material was also calculationally analyzed with the PSYCHE code developed by PNC. These analytical results were compared with the measured results to get the verification of analysis methods and to estimate the accuracy of calculations

  14. Nutrient sequestration in Aquitaine lakes (SW France) limits nutrient flux to the coastal zone

    Science.gov (United States)

    Buquet, Damien; Anschutz, Pierre; Charbonnier, Céline; Rapin, Anne; Sinays, Rémy; Canredon, Axel; Bujan, Stéphane; Poirier, Dominique

    2017-12-01

    Oligotrophic coastal zones are disappearing from increased nutrient loading. The quantity of nutrients reaching the coast is determined not only by their original source (e.g. fertilizers used in agriculture, waste water discharges) and the land use, but also by the pathways through which nutrients are cycled from the source to the river mouth. In particular, lakes sequester nutrients and, hence, reduce downstream transfer of nutrients to coastal environments. Here, we quantify the impact of Aquitaine great lakes on the fluxes of dissolved macro-nutrients (N, P, Si) to the Bay of Biscay. For that, we have measured nutrient concentrations and fluxes in 2014 upstream and downstream lakes of Lacanau and Carcans-Hourtin, which belongs to the catchment of the Arcachon Bay, which is the largest coastal lagoon of the Bay of Biscay French coast. Data were compared to values obtained from the Leyre river, the main freshwater and nutrient source for the lagoon. Results show that processes in lakes greatly limit nutrient flux to the lagoon compared to fluxes from Leyre river, although the watershed is similar in terms of land cover. In lakes, phosphorus and silicon are trapped for long term in the sediment, silicon as amorphous biogenic silica and phosphorus as organic P and P associated with Fe-oxides. Nitrogen that enters lakes mostly as nitrate is used for primary production. N is mineralized in the sediment; a fraction diffuses as ammonium. N2 production through benthic denitrification extracts only 10% of dissolved inorganic nitrogen from the aquatic system. The main part is sequestered in organic-rich sediment that accumulates below 5 m depth in both lakes.

  15. A chronology of El niño events from primary documentary sources in northern Peru

    OpenAIRE

    García Herrera, Ricardo; Díaz, H. F.; García, R. R.; Prieto, M. R.; Barriopedro Cepero, David; Moyano, R.; Hernández Martín, Emiliano

    2008-01-01

    The authors present a chronology of El Niño (EN) events based on documentary records from northern Peru. The chronology, which covers the period 1550-1900, is constructed mainly from primary sources from the city of Trujillo (Peru), the Archivo General de Indias in Seville (Spain), and the Archivo General de la Nacion in Lima (Peru), supplemented by a reassessment of documentary evidence included in previously published literature. The archive in Trujillo has never been systematically evaluat...

  16. Linking source region and ocean wave parameters with the observed primary microseismic noise

    Science.gov (United States)

    Juretzek, C.; Hadziioannou, C.

    2017-12-01

    In previous studies, the contribution of Love waves to the primary microseismic noise field was found to be comparable to those of Rayleigh waves. However, so far only few studies analysed both wave types present in this microseismic noise band, which is known to be generated in shallow water and the theoretical understanding has mainly evolved for Rayleigh waves only. Here, we study the relevance of different source region parameters on the observed primary microseismic noise levels of Love and Rayleigh waves simultaneously. By means of beamforming and correlation of seismic noise amplitudes with ocean wave heights in the period band between 12 and 15 s, we analysed how source areas of both wave types compare with each other around Europe. The generation effectivity in different source regions was compared to ocean wave heights, peak ocean gravity wave propagation direction and bathymetry. Observed Love wave noise amplitudes correlate comparably well with near coastal ocean wave parameters as Rayleigh waves. Some coastal regions serve as especially effective sources for one or the other wave type. These coincide not only with locations of high wave heights but also with complex bathymetry. Further, Rayleigh and Love wave noise amplitudes seem to depend equally on the local ocean wave heights, which is an indication for a coupled variation with swell height during the generation of both wave types. However, the wave-type ratio varies directionally. This observation likely hints towards a spatially varying importance of different source mechanisms or structural influences. Further, the wave-type ratio is modulated depending on peak ocean wave propagation directions which could indicate a variation of different source mechanism strengths but also hints towards an imprint of an effective source radiation pattern. This emphasizes that the inclusion of both wave types may provide more constraints for the understanding of acting generation mechanisms.

  17. Comparative study on nutrient removal of agricultural non-point source pollution for three filter media filling schemes in eco-soil reactors.

    Science.gov (United States)

    Du, Fuyi; Xie, Qingjie; Fang, Longxiang; Su, Hang

    2016-08-01

    Nutrients (nitrogen and phosphorus) from agricultural non-point source (NPS) pollution have been increasingly recognized as a major contributor to the deterioration of water quality in recent years. The purpose of this article is to investigate the discrepancies in interception of nutrients in agricultural NPS pollution for eco-soil reactors using different filling schemes. Parallel eco-soil reactors of laboratory scale were created and filled with filter media, such as grit, zeolite, limestone, and gravel. Three filling schemes were adopted: increasing-sized filling (I-filling), decreasing-sized filling (D-filling), and blend-sized filling (B-filling). The systems were intermittent operations via simulated rainstorm runoff. The nutrient removal efficiency, biomass accumulation and vertical dissolved oxygen (DO) distribution were defined to assess the performance of eco-soil. The results showed that B-filling reactor presented an ideal DO for partial nitrification-denitrification across the eco-soil, and B-filling was the most stable in the change of bio-film accumulation trends with depth in the three fillings. Simultaneous and highest removals of NH4(+)-N (57.74-70.52%), total nitrogen (43.69-54.50%), and total phosphorus (42.50-55.00%) were obtained in the B-filling, demonstrating the efficiency of the blend filling schemes of eco-soil for oxygen transfer and biomass accumulation to cope with agricultural NPS pollution.

  18. Nutrient intake, productive performance and body measurements of dairy heifers fed with different sources of protein - doi: 10.4025/actascianimsci.v35i3.18749

    Directory of Open Access Journals (Sweden)

    Andressa Fereirra Ribeiro

    2013-07-01

    Full Text Available This study evaluated the effect of different protein sources (soybean meal, cottonseed meal, peanut meal and sunflower meal on dry matter and nutrient intake, productive performance and body measurements of dairy heifers, Holstein x Zebu, recreated in confinement. The experiment consisted in a randomized complete block design made up by 6 replications and 4 treatments. The mean values of ingestion of ether extract (EEI, kg day-1 were statistically different (p -1 to the diet with sunflower meal (0.82 kg day-1, and considering the final body weight, the diet with soybean meal was superior to the other treatments (p  

  19. Primary sources of selected POPs: regional and global scale emission inventories

    Energy Technology Data Exchange (ETDEWEB)

    Breivik, Knut; Alcock, Ruth; Li Yifan; Bailey, Robert E.; Fiedler, Heidelore; Pacyna, Jozef M

    2004-03-01

    During the last decade, a number of studies have been devoted to the sources and emissions of Persistent Organic Pollutants (POPs) at regional and global scales. While significant improvements in knowledge have been achieved for some pesticides, the quantitative understanding of the emission processes and emission patterns for 'non-pesticide' POPs are still considered limited. The key issues remaining for the non-pesticide POPs are in part determined by their general source classification. For industrial chemicals, such as the polychlorinated biphenyls (PCBs), there is considerable uncertainty with respect to the relative importance of atmospheric emissions from various source categories. For PCBs, temperature is discussed as a potential key factor influencing atmospheric emission levels and patterns. When it comes to the unintentional by-products of combustion and industrial processes (PCDD/Fs), there is still a large uncertainty with respect to the relative contribution of emissions from unregulated sources such as backyard barrel burning that requires further consideration and characterisation. For hexachlorobenzene (HCB), the relative importance of primary and secondary atmospheric emissions in controlling current atmospheric concentrations remains one of the key uncertainties. While these and other issues may remain unresolved, knowledge concerning the emissions of POPs is a prerequisite for any attempt to understand and predict the distribution and fate of these chemicals on a regional and global scale as well as to efficiently minimise future environmental burdens. - Knowledge of primary emissions is a prerequisite for understanding and predicting POPs on a regional/global scale.

  20. Primary sources of selected POPs: regional and global scale emission inventories

    International Nuclear Information System (INIS)

    Breivik, Knut; Alcock, Ruth; Li Yifan; Bailey, Robert E.; Fiedler, Heidelore; Pacyna, Jozef M.

    2004-01-01

    During the last decade, a number of studies have been devoted to the sources and emissions of Persistent Organic Pollutants (POPs) at regional and global scales. While significant improvements in knowledge have been achieved for some pesticides, the quantitative understanding of the emission processes and emission patterns for 'non-pesticide' POPs are still considered limited. The key issues remaining for the non-pesticide POPs are in part determined by their general source classification. For industrial chemicals, such as the polychlorinated biphenyls (PCBs), there is considerable uncertainty with respect to the relative importance of atmospheric emissions from various source categories. For PCBs, temperature is discussed as a potential key factor influencing atmospheric emission levels and patterns. When it comes to the unintentional by-products of combustion and industrial processes (PCDD/Fs), there is still a large uncertainty with respect to the relative contribution of emissions from unregulated sources such as backyard barrel burning that requires further consideration and characterisation. For hexachlorobenzene (HCB), the relative importance of primary and secondary atmospheric emissions in controlling current atmospheric concentrations remains one of the key uncertainties. While these and other issues may remain unresolved, knowledge concerning the emissions of POPs is a prerequisite for any attempt to understand and predict the distribution and fate of these chemicals on a regional and global scale as well as to efficiently minimise future environmental burdens. - Knowledge of primary emissions is a prerequisite for understanding and predicting POPs on a regional/global scale

  1. Extent of Head Teachers' Utilization of Innovative Sources of Funding Primary Schools in Enugu State of Nigeria

    Science.gov (United States)

    Amogechukwu, Eze Thecla; Unoma, Chidobi Roseline

    2017-01-01

    The purpose of this study was to examine the extent Head teachers utilize innovative sources of funding primary schools in Enugu State of Nigeria. Descriptive survey design was employed to examine the extent head teachers utilize innovative sources of funding primary schools in Enugu State. Data were collected through a 14-item questionnaire…

  2. Quantitative evaluation of emission controls on primary and secondary organic aerosol sources during Beijing 2008 Olympics

    Directory of Open Access Journals (Sweden)

    S. Guo

    2013-08-01

    Full Text Available To assess the primary and secondary sources of fine organic aerosols after the aggressive implementation of air pollution controls during the 2008 Beijing Olympic Games, 12 h PM2.5 values were measured at an urban site at Peking University (PKU and an upwind rural site at Yufa during the CAREBEIJING-2008 (Campaigns of Air quality REsearch in BEIJING and surrounding region summer field campaign. The average PM2.5 concentrations were 72.5 ± 43.6 μg m−3 and 64.3 ± 36.2 μg m−3 (average ± standard deviation, below as the same at PKU and Yufa, respectively, showing the lowest concentrations in recent years. Combining the results from a CMB (chemical mass balance model and secondary organic aerosol (SOA tracer-yield model, five primary and four secondary fine organic aerosol sources were compared with the results from previous studies in Beijing. The relative contribution of mobile sources to PM2.5 concentrations was increased in 2008, with diesel engines contributing 16.2 ± 5.9% and 14.5 ± 4.1% and gasoline vehicles contributing 10.3 ± 8.7% and 7.9 ± 6.2% to organic carbon (OC at PKU and Yufa, respectively. Due to the implementation of emission controls, the absolute OC concentrations from primary sources were reduced during the Olympics, and the contributions from secondary formation of OC represented a larger relative source of fine organic aerosols. Compared with the non-controlled period prior to the Olympics, primary vehicle contributions were reduced by 30% at the urban site and 24% at the rural site. The reductions in coal combustion contributions were 57% at PKU and 7% at Yufa. Our results demonstrate that the emission control measures implemented in 2008 significantly alleviated the primary organic particle pollution in and around Beijing. However, additional studies are needed to provide a more comprehensive assessment of the emission control effectiveness on SOA formation.

  3. Source Material and Concentration of Wildfire-Produced Pyrogenic Carbon Influence Post-Fire Soil Nutrient Dynamics

    Directory of Open Access Journals (Sweden)

    Lucas A. Michelotti

    2015-04-01

    Full Text Available Pyrogenic carbon (PyC is produced by the thermal decomposition of organic matter in the absence of oxygen (O. PyC affects nutrient availability, may enhance post-fire nitrogen (N mineralization rates, and can be a significant carbon (C pool in fire-prone ecosystems. Our objectives were to characterize PyC produced by wildfires and examine the influence that contrasting types of PyC have on C and N mineralization rates. We determined C, N, O, and hydrogen (H concentrations and atomic ratios of charred bark (BK, charred pine cones (PC, and charred woody debris (WD using elemental analysis. We also incubated soil amended with BK, PC, and WD at two concentrations for 60 days to measure C and N mineralization rates. PC had greater H/C and O/C ratios than BK and WD, suggesting that PC may have a lesser aromatic component than BK and WD. C and N mineralization rates decreased with increasing PyC concentrations, and control samples produced more CO2 than soils amended with PyC. Soils with PC produced greater CO2 and had lower N mineralization rates than soils with BK or WD. These results demonstrate that PyC type and concentration have potential to impact nutrient dynamics and C flux to the atmosphere in post-fire forest soils.

  4. Enzyme activities of phytoplankton in the South Shetland Islands (Antarctica in relation to nutrients and primary production Actividad enzimática en ensambles fitoplanctónicos en las Islas Shetland del Sur (Antártica en relación a los nutrientes y producción primaria

    Directory of Open Access Journals (Sweden)

    JOSÉ L IRIARTE

    2006-12-01

    Full Text Available Given the potential significance of enzyme activities as a link between internal metabolic pathways and environmental nutrients, we investigated the relationships of nitrate reductase (NR and alkaline phosphatase (AP with primary production and inorganic nutrients in South Shetland Islands, Antarctica. Enzymatic activities of the phytoplankton (0.7-210 µm, primary productivity, autotrophic biomass and inorganic nutrients were studied in the upper 100 m depth at nine stations during a cruise in the northwestern area of South Shetland Islands (Antarctica, during late austral spring (December 2000. NR activities fluctuated between 0 and 42.8 nmol L-1 h-1 (mean = 10.08 nmol L-1 h-1, SD = 10.42 nmol L-1 h-1, AP activities between 0.81 and 5.67 nmol L-1 h-1 (mean = 2.68 nmol L-1 h-1, SD = 0.95 nmol L-1 h-1. Stations with primary productivity (PP and chlorophyll a greater than 2 mg C m-3 h-1 and 0.75 mg chlorophyll a L-1, respectively, presented higher enzymatic activities of nitrate reductase, alkaline phosphatase than those stations characterized by primary productivity and chlorophyll a less than 2 mg C m-3 h-1 and 0.17 mg chlorophyll a L-1, respectively. The AP specific activity was negatively correlated with orthophosphate concentrations lower than 2.0 µM, which indicates that the microplankton were under phosphate deficient environment condition. Our results indicated that NR specific activity was positively associated with autotrophic biomass and primary productivity estimates, giving evidence of the use of nitrate by phytoplankton as external nitrogen source in surface waters. In addition, high NR activities were positively correlated with NO3-, suggesting the occurrence of nitrate respiration in the well oxygenated surface waters of AntarcticaDada la potencial importancia de la actividad enzimática de ensambles fitoplanctónicos, como indicador de su metabolismo interno dominante respecto de los nutrientes, este estudio investigó las

  5. Temperature, salinity, transmissivity, pressure, plankton, oxygen, nutrients, chlorophyll, and primary productivity data collected using CTD, bottle, and plankton net from the R/V Italica in the Ross Sea and Magellan Strait during 10th Italian Antarctic Expedition from 1994-11-13 to 1995-04-02 (NCEI Accession 0068289)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, transmissivity, pressure, plankton, oxygen, nutrients, chlorophyll, and primary productivity data collected using CTD, bottle, and plankton...

  6. THE SOURCES OF NUTRIENTS IN WATERS OF RIVERS IN THE WETLAND AREAS OF NAREW NATIONAL PARK IN NORTH-EASTERN POLAND

    Directory of Open Access Journals (Sweden)

    Mirosław Skorbiłowicz

    2013-07-01

    Full Text Available The study aimed at the attempt to identify and to evaluate the interaction intensity, and to classify the sources of river waters nutrients in the catchment of upper river Narew within Narew National Park (north-eastern Poland. The studies were carried out on Narew river within borders of Narew National Park, where 5 measurement-control points were localized as well as one near estuaries of its 5 tributaries (Awissa, Czaplinianka, Horodnianka, Turośnianka and Supraśl. Factor analysis (FA from multi-dimensional group was applied for statistical processing of study results, because it is commonly used to describe and explore a large number of data. concentrations of analyzed chemicals depended on a water sampling point that was under anthropopression and geogenic conditions. Studies and results from analyses (FA and CA allowed for identifying the main sources of river Narew nutrients within Narew National Park. These are: tributaries of river Narew, point and distributed runoffs, as well as shallow ground waters that transport components having anthropogenic and partially geogenic-lithologic origin. River Turośnianka supplies the largest loads of studied parameters to river Narew within Narew National Park boundaries. River Supraśl is the most contaminated tributary of river Narew.

  7. Soil Aquifer Treatment (SAT) and Constructed Wetlands (CW) Applications for Nutrients and Organic Micropollutants (OMPs) Attenuation Using Primary and Secondary Wastewater Effluents

    KAUST Repository

    Hamadeh, Ahmed F.

    2014-06-01

    Constructed wetlands (CW) and soil aquifer treatment (SAT) represent natural wastewater treatment systems (NWTSs). The high costs of conventional wastewater treatment techniques encourage more studies to investigate lower cost treatment methods which make these appropriate for developing and also in developed countries. The main objective of this research was to investigate the removals of nutrients and organic micropollutants (OMPs) through SAT, CW and the CW-SAT hybrid system. CWs are an efficient technology to purify and remove different nutrients as well as OMPs from wastewater. They removed most of the dissolved organic matter (DOC), total nitrogen (TN), ammonium and phosphate. Furthermore, CWs aeration could be used as one of the alternatives to reduce CWs footprint by around 10%. The vegetation in CWs plays an essential role in the treatment especially for nitrogen and phosphate removals, it is responsible for the removal of 15%, 55%, 38%, and 22% for TN, dissolved organic nitrogen (DON), nitrate and phosphate, respectively. CWs achieved a very high removal for some OMPs; they attenuated acetaminophen, caffeine, fluoxetine and trimethoprim (>90%) under different redox conditions. Moreover, it was found that increasing temperature (up to 36 C) could enhance the removals of atenolol, caffeine, DEET and trimethoprim by 17%, 14%, 28% and 45%, respectively. On the other hand, some OMPs, were found to be removed by vegetation such as: acetaminophen, caffeine, fluoxetine, sulfamethoxazole, and trimethoprim. Moreover, atenolol, caffeine, fluoxetine and trimethoprim, showed high removal (>80%) through SAT system. It was also found that, temperature increasing and using primary instead of secondary effluent could enhance the removal of some OMPs. The CWs performance study showed that these systems are adapted to the prevailing extreme arid conditions and the average percent removals are about, 88%, 96%, 98%, 98% and 92%, for COD, BOD and TSS, ammonium and phosphate

  8. Sun-induced chlorophyll fluorescence and photochemical reflectance index improve remote-sensing gross primary production estimates under varying nutrient availability in a typical Mediterranean savanna ecosystem

    Science.gov (United States)

    Perez-Priego, O.; Guan, J.; Rossini, M.; Fava, F.; Wutzler, T.; Moreno, G.; Carvalhais, N.; Carrara, A.; Kolle, O.; Julitta, T.; Schrumpf, M.; Reichstein, M.; Migliavacca, M.

    2015-11-01

    This study investigates the performances of different optical indices to estimate gross primary production (GPP) of herbaceous stratum in a Mediterranean savanna with different nitrogen (N) and phosphorous (P) availability. Sun-induced chlorophyll fluorescence yield computed at 760 nm (Fy760), scaled photochemical reflectance index (sPRI), MERIS terrestrial-chlorophyll index (MTCI) and normalized difference vegetation index (NDVI) were computed from near-surface field spectroscopy measurements collected using high spectral resolution spectrometers covering the visible near-infrared regions. GPP was measured using canopy chambers on the same locations sampled by the spectrometers. We tested whether light-use efficiency (LUE) models driven by remote-sensing quantities (RSMs) can better track changes in GPP caused by nutrient supplies compared to those driven exclusively by meteorological data (MM). Particularly, we compared the performances of different RSM formulations - relying on the use of Fy760 or sPRI as a proxy for LUE and NDVI or MTCI as a fraction of absorbed photosynthetically active radiation (fAPAR) - with those of classical MM. Results showed higher GPP in the N-fertilized experimental plots during the growing period. These differences in GPP disappeared in the drying period when senescence effects masked out potential differences due to plant N content. Consequently, although MTCI was closely related to the mean of plant N content across treatments (r2 = 0.86, p < 0.01), it was poorly related to GPP (r2 = 0.45, p < 0.05). On the contrary sPRI and Fy760 correlated well with GPP during the whole measurement period. Results revealed that the relationship between GPP and Fy760 is not unique across treatments, but it is affected by N availability. Results from a cross-validation analysis showed that MM (AICcv = 127, MEcv = 0.879) outperformed RSM (AICcv =140, MEcv = 0.8737) when soil moisture was used to constrain the seasonal dynamic of LUE. However

  9. Ancient settlements are significant sources of nutrients in Eastern Mediterranean ecosystems - the case of Tel Burna, Israel

    Science.gov (United States)

    Smejda, Ladislav; Hejcman, Michal; Shai, Itzhaq

    2016-04-01

    Past human settlement activities have caused changes in soil chemical properties that may persist in the cultural soil archive for a very long time and some of them are practically irreversible. We are studying the question if the large-scale mapping of elemental composition based on the surface layer of contemporary soil can reveal spatial patterns corresponding to areas of settlements, which were abandoned even millennia ago. Our case-study is focused on the archaeological site of Tel Burna, located in the Shephelah region, Israel, and its immediate surroundings, making a survey area of 68 ha. The site is known as the town flourishing mainly in the Late Bronze Age and Iron Age (13th-7th centuries BCE). The heyday of the town was during the 10th - 8th centuries BCE, when its summit was enclosed by a massive limestone wall. Later on the significance of the settlement declined, and the architecture vanished. The place has gradually turned to an uninhabited area, used in the recent period as a pasture. We have measured the chemical composition of 350 samples from the surface soil at and around the site by a portable XRF device as part of an on-going interdisciplinary research project studying this site. The results were analysed by standard statistical methods and also in geographical information systems, which were used for calculating models of elemental distribution patterns across the surveyed area. In this paper we discuss the observation that the anthropogenic impact on the chemical composition of soils became quite significant already in times of ancient societies. This human-induced signature was of such magnitude that it can still be detected today, not only in the sub-surface archaeological deposits, but also on the very surface of the present-day landscape. We are able to demonstrate that the nutrients accumulated within the precincts of ancient settlements through the intensive deposition of organic and inorganic waste have been slowly released into local

  10. Primary and secondary organic aerosol origin by combined gas-particle phase source apportionment

    Directory of Open Access Journals (Sweden)

    M. Crippa

    2013-08-01

    Full Text Available Secondary organic aerosol (SOA, a prominent fraction of particulate organic mass (OA, remains poorly constrained. Its formation involves several unknown precursors, formation and evolution pathways and multiple natural and anthropogenic sources. Here a combined gas-particle phase source apportionment is applied to wintertime and summertime data collected in the megacity of Paris in order to investigate SOA origin during both seasons. This was possible by combining the information provided by an aerosol mass spectrometer (AMS and a proton transfer reaction mass spectrometer (PTR-MS. A better constrained apportionment of primary OA (POA sources is also achieved using this methodology, making use of gas-phase tracers. These tracers made possible the discrimination between biogenic and continental/anthropogenic sources of SOA. We found that continental SOA was dominant during both seasons (24–50% of total OA, while contributions from photochemistry-driven SOA (9% of total OA and marine emissions (13% of total OA were also observed during summertime. A semi-volatile nighttime component was also identified (up to 18% of total OA during wintertime. This approach was successfully applied here and implemented in a new source apportionment toolkit.

  11. Source contributions and regional transport of primary particulate matter in China.

    Science.gov (United States)

    Hu, Jianlin; Wu, Li; Zheng, Bo; Zhang, Qiang; He, Kebin; Chang, Qing; Li, Xinghua; Yang, Fumo; Ying, Qi; Zhang, Hongliang

    2015-12-01

    A source-oriented CMAQ was applied to determine source sector/region contributions to primary particulate matter (PPM) in China. Four months were simulated with emissions grouped to eight regions and six sectors. Predicted elemental carbon (EC), primary organic carbon (POC), and PPM concentrations and source contributions agree with measurements and have significant spatiotemporal variations. Residential is a major contributor to spring/winter EC (50-80%), POC (60%-90%), and PPM (30-70%). For summer/fall, industrial contributes 30-50% for EC/POC and 40-60% for PPM. Transportation is more important for EC (20-30%) than POC/PPM (Guangzhou and Chongqing. Dust contributes to 1/3-1/2 in spring/fall of Beijing, Xi'an and Chongqing. Based on sector-region combination, local residential/transportation and residential/industrial from Heibei are major contributors to spring PPM in Beijing. In summer/fall, local industrial is the largest. In winter, residential/industrial from local and Hebei account for >90% in Beijing. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Interpreting stream sediment fingerprints against primary and secondary source signatures in agricultural catchments

    Science.gov (United States)

    Blake, Will H.; Haley, Steve; Smith, Hugh G.; Taylor, Alex; Goddard, Rupert; Lewin, Sean; Fraser, David

    2013-04-01

    Many sediment fingerprinting studies adopt a black box approach to source apportionment whereby the properties of downstream sediment are compared quantitatively to the geochemical fingerprints of potential catchment sources without consideration of potential signature development or modification during transit. Working within a source-pathway-receptor framework, this study aimed to undertake sediment source apportionment within 6 subcatchments of an agricultural river basin with specific attention to the potential role of contaminants (vehicle emissions and mine waste) in development of stream sediment signatures. Fallout radionuclide (FRN) and geochemical fingerprinting methods were adopted independently to establish source signatures for primary sediment sources of surface and subsurface soil materials under various land uses plus reworked mine and 'secondary' soil material deposited, in transit, along road networks. FRN data demonstrated expected variability between surface soil (137Cs = 14 ± 3 Bq kg-1; 210Pbxs = 40 ± 7 Bq kg-1) and channel bank materials (137Cs = 3 ± 1 Bq kg-1; 210Pbxs = 24 ± 5 Bq kg-1) but road transported soil material was considerably elevated in 210Pbxs (up to 673 ± 51 Bq kg-1) due to sediment interaction with pluvial surface water within the road network. Geochemical discrimination between surface and subsurface soil materials was dominated by alkaline earth and alkali metals e.g. Ba, Rb, Ca, K, Mg which are sensitive to weathering processes in soil. Magnetic susceptibility and heavy metals were important discriminators of road transported material which demonstrated transformation of the signatures of material transported via the road network. Numerical unmixing of stream sediment indicated that alongside channel bank erosion, road transported material was an important component in some systems in accord with FRN evidence. While mining spoil also ranked as a significant source in an affected catchment, perhaps related to legacy

  13. Monitoring of PM10 and PM2.5 around primary particulate anthropogenic emission sources

    Science.gov (United States)

    Querol, Xavier; Alastuey, Andrés; Rodriguez, Sergio; Plana, Felicià; Mantilla, Enrique; Ruiz, Carmen R.

    Investigations on the monitoring of ambient air levels of atmospheric particulates were developed around a large source of primary anthropogenic particulate emissions: the industrial ceramic area in the province of Castelló (Eastern Spain). Although these primary particulate emissions have a coarse grain-size distribution, the atmospheric transport dominated by the breeze circulation accounts for a grain-size segregation, which results in ambient air particles occurring mainly in the 2.5-10 μm range. The chemical composition of the ceramic particulate emissions is very similar to the crustal end-member but the use of high Al, Ti and Fe as tracer elements as well as a peculiar grain-size distribution in the insoluble major phases allow us to identify the ceramic input in the bulk particulate matter. PM2.5 instead of PM10 monitoring may avoid the interference of crustal particles without a major reduction in the secondary anthropogenic load, with the exception of nitrate. However, a methodology based in PM2.5 measurement alone is not adequate for monitoring the impact of primary particulate emissions (such as ceramic emissions) on air quality, since the major ambient air particles derived from these emissions are mainly in the range of 2.5-10 μm. Consequently, in areas characterised by major secondary particulate emissions, PM2.5 monitoring should detect anthropogenic particulate pollutants without crustal particulate interference, whereas PM10 measurements should be used in areas with major primary anthropogenic particulate emissions.

  14. Identification of Standing Pressure Waves Sources in Primary Loops of NPP with WWER and PWR

    Directory of Open Access Journals (Sweden)

    K.N. Proskuriakov

    2016-05-01

    Full Text Available Results of measurement and calculation of Eigen frequencies of coolant pressure oscillations in primary loops of NPP are presented. The simple calculation model based on equivalence of electric circuit with elastic wave propagation in liquids and gases, which gives a sensible interpretation of standing pressure waves sources is developed. It is shown, that pressurizer manifest itself as managed Helmholtz resonator generating a number of SPW (with Eigen frequencies of steam volume, water volume and their combination with coolant volume of respiratory line.

  15. The Use of Energy in Malaysia: Tracing Energy Flows from Primary Source to End Use

    OpenAIRE

    Chinhao Chong; Weidou Ni; Linwei Ma; Pei Liu; Zheng Li

    2015-01-01

    Malaysia is a rapidly developing country in Southeast Asia that aims to achieve high-income country status by 2020; its economic growth is highly dependent on its abundant energy resources, especially natural gas and crude oil. In this paper, a complete picture of Malaysia’s energy use from primary source to end use is presented by mapping a Sankey diagram of Malaysia’s energy flows, together with ongoing trends analysis of the main factors influencing the energy flows. The results indicate t...

  16. The impact of food and nutrient-based standards on primary school children's lunch and total dietary intake: a natural experimental evaluation of government policy in England.

    Science.gov (United States)

    Spence, Suzanne; Delve, Jennifer; Stamp, Elaine; Matthews, John N S; White, Martin; Adamson, Ashley J

    2013-01-01

    In 2005, the nutritional content of children's school lunches in England was widely criticised, leading to a major policy change in 2006. Food and nutrient-based standards were reintroduced requiring primary schools to comply by September 2008. We aimed to determine the effect of the policy on the nutritional content at lunchtime and in children's total diet. We undertook a natural experimental evaluation, analysing data from cross-sectional surveys in 12 primary schools in North East England, pre and post policy. Dietary data were collected on four consecutive days from children aged 4-7 years (n = 385 in 2003-4; n = 632 in 2008-9). We used linear mixed effect models to analyse the effects of gender, year, and lunch type on children's mean total daily intake. Both pre- and post-implementation, children who ate a school lunch consumed less sodium (mean change -128 mg, 95% CI: -183 to -73 mg) in their total diet than children eating home-packed lunches. Post-implementation, children eating school lunches consumed a lower % energy from fat (-1.8%, -2.8 to -0.9) and saturated fat (-1.0%; -1.6 to -0.5) than children eating packed lunches. Children eating school lunches post implementation consumed significantly more carbohydrate (16.4 g, 5.3 to 27.6), protein (3.6 g, 1.1 to 6.0), non-starch polysaccharides (1.5 g, 0.5 to 1.9), vitamin C (0.7 mg, 0.6 to 0.8), and folate (12.3 µg, 9.7 to 20.4) in their total diet than children eating packed lunches. Implementation of school food policy standards was associated with significant improvements in the nutritional content of school lunches; this was reflected in children's total diet. School food- and nutrient-based standards can play an important role in promoting dietary health and may contribute to tackling childhood obesity. Similar policy measures should be considered for other environments influencing children's diet.

  17. The impact of food and nutrient-based standards on primary school children's lunch and total dietary intake: a natural experimental evaluation of government policy in England.

    Directory of Open Access Journals (Sweden)

    Suzanne Spence

    Full Text Available In 2005, the nutritional content of children's school lunches in England was widely criticised, leading to a major policy change in 2006. Food and nutrient-based standards were reintroduced requiring primary schools to comply by September 2008. We aimed to determine the effect of the policy on the nutritional content at lunchtime and in children's total diet. We undertook a natural experimental evaluation, analysing data from cross-sectional surveys in 12 primary schools in North East England, pre and post policy. Dietary data were collected on four consecutive days from children aged 4-7 years (n = 385 in 2003-4; n = 632 in 2008-9. We used linear mixed effect models to analyse the effects of gender, year, and lunch type on children's mean total daily intake. Both pre- and post-implementation, children who ate a school lunch consumed less sodium (mean change -128 mg, 95% CI: -183 to -73 mg in their total diet than children eating home-packed lunches. Post-implementation, children eating school lunches consumed a lower % energy from fat (-1.8%, -2.8 to -0.9 and saturated fat (-1.0%; -1.6 to -0.5 than children eating packed lunches. Children eating school lunches post implementation consumed significantly more carbohydrate (16.4 g, 5.3 to 27.6, protein (3.6 g, 1.1 to 6.0, non-starch polysaccharides (1.5 g, 0.5 to 1.9, vitamin C (0.7 mg, 0.6 to 0.8, and folate (12.3 µg, 9.7 to 20.4 in their total diet than children eating packed lunches. Implementation of school food policy standards was associated with significant improvements in the nutritional content of school lunches; this was reflected in children's total diet. School food- and nutrient-based standards can play an important role in promoting dietary health and may contribute to tackling childhood obesity. Similar policy measures should be considered for other environments influencing children's diet.

  18. Utilization of supplemental methionine sources by primary cultures of chick hepatocytes

    International Nuclear Information System (INIS)

    Dibner, J.J.

    1983-01-01

    Utilization of 2-hydroxy-4-(methylthio) butanoic acid (HMB) as a substrate for protein synthesis was studied by using primary cultures of chick liver cells. Cultures were prepared by enzymatic dissociation of livers from week old Hubbard broiler chicks and were maintained for 4 days under nonproliferative conditions. Hepatocyte differentiation was verified by using dexamethasone induction of tyrosine aminotransferase activity. Conversion of [14C]HMB to L-methionine was shown by chromatographic analysis of hepatocyte protein hydrolysate and incorporation into protein was proven by cycloheximide inhibition of synthesis. When incorporation of HMB was compared to that of DL-methionine (DLM) equimolar quantities of the two sources were found in liver cell protein. These results support, at a cellular level, the conclusion that HMB and DLM are biochemically equivalent sources of methionine for protein synthesis

  19. The Feasibility of Onsite Electrolysis as Primary and Clean Production Source of Fuel Hydrogen in Brazil

    International Nuclear Information System (INIS)

    COSTA, Andre R

    2006-01-01

    In accordance with the International Monetary Fund Brazil is currently the world's 12. largest and Latin America's largest economy, with a nominal GPD in the amount of US dollars 732,078 millions. Despite the fact that energy production is still heavily based on hydrocarbons, such as oil, natural gas and coal, the country is often indicated as one of the worldwide leaders in implementing renewable energy sources, primarily due to the spread utilization of bio-ethanol in transportation and the electricity production from hydropower. The purpose of this study is to assess the feasibility of onsite electrolysis as primary and clean source of fuel hydrogen in Brazil, indicating the main advantages of this production method. A perspective of the most significant challenges and actions to be taken regarding the accomplishment of a clean Brazilian hydrogen economy will be presented herein. (author)

  20. The source of display rules and their effects on primary health care professionals' well-being.

    Science.gov (United States)

    Martínez-Iñigo, David; Totterdell, Peter; Alcover, Carlos Maria; Holman, David

    2009-11-01

    Employees' perceptions of the emotional requirements of their work role are considered a necessary antecedent of emotion work. The impact of these requirements on the emotions employees display, their well-being, and their clients' satisfaction has been explored in previous research. Emotional requirements have been characterized as organizationally-based expectations (e.g., Brotheridge & Lee, 2003), formal and informal organizational rules (e.g., Cropanzano, Weiss & Elias, 2004), occupational norms (e.g., Rafaeli & Sutton, 1987; Smith & Kleinman, 1989) and job-based demands (Brotheridge & Lee, 2002). Although all these definitions assume some kind of shared source for perceptions of emotional requirements, it remains unclear to what extent these different sources contribute and to what extent the requirements are shared by different units, teams and individuals in the organization. The present study analyses the perception of emotional requirements from a survey of ninety-seven Primary Health Care teams composed of general practitioners, nurses and administrative staff (N = 1057). The relative contribution of different sources of variance (team, organizational, and occupational) to perceived emotional requirements and the effects on employees' job satisfaction and well being are examined. Results confirm the relevance of the source and show the contribution of emotional demands to prediction of emotional exhaustion and job satisfaction levels.

  1. Occurrence of anthropogenic organic compounds and nutrients in source and finished water in the Sioux Falls area, South Dakota, 2009-10

    Science.gov (United States)

    Hoogestraat, Galen K.

    2012-01-01

    Anthropogenic organic compounds (AOCs) in drinking-water sources commonly are derived from municipal, agricultural, and industrial wastewater sources, and are a concern for water-supply managers. A cooperative study between the city of Sioux Falls, S. Dak., and the U.S. Geological Survey was initiated in 2009 to (1) characterize the occurrence of anthropogenic organic compounds in the source waters (groundwater and surface water) to water supplies in the Sioux Falls area, (2) determine if the compounds detected in the source waters also are present in the finished water, and (3) identify probable sources of nitrate in the Big Sioux River Basin and determine if sources change seasonally or under different hydrologic conditions. This report presents analytical results of water-quality samples collected from source waters and finished waters in the Sioux Falls area. The study approach included the collection of water samples from source and finished waters in the Sioux Falls area for the analyses of AOCs, nutrients, and nitrogen and oxygen isotopes in nitrate. Water-quality constituents monitored in this study were chosen to represent a variety of the contaminants known or suspected to occur within the Big Sioux River Basin, including pesticides, pharmaceuticals, sterols, household and industrial products, polycyclic aromatic hydrocarbons, antibiotics, and hormones. A total of 184 AOCs were monitored, of which 40 AOCs had relevant human-health benchmarks. During 11 sampling visits, 45 AOCs (24 percent) were detected in at least one sample of source or finished water, and 13 AOCs were detected in at least 20 percent of all samples. Concentrations of detected AOCs were all less than 1 microgram per liter, except for two AOCs in multiple samples from the Big Sioux River, and one AOC in finished-water samples. Concentrations of AOCs were less than 0.1 microgram per liter in more than 75 percent of the detections. Nutrient concentrations varied seasonally in source

  2. Haemophilus ducreyi Seeks Alternative Carbon Sources and Adapts to Nutrient Stress and Anaerobiosis during Experimental Infection of Human Volunteers.

    Science.gov (United States)

    Gangaiah, Dharanesh; Zhang, Xinjun; Baker, Beth; Fortney, Kate R; Gao, Hongyu; Holley, Concerta L; Munson, Robert S; Liu, Yunlong; Spinola, Stanley M

    2016-05-01

    Haemophilus ducreyi causes the sexually transmitted disease chancroid in adults and cutaneous ulcers in children. In humans, H. ducreyi resides in an abscess and must adapt to a variety of stresses. Previous studies (D. Gangaiah, M. Labandeira-Rey, X. Zhang, K. R. Fortney, S. Ellinger, B. Zwickl, B. Baker, Y. Liu, D. M. Janowicz, B. P. Katz, C. A. Brautigam, R. S. Munson, Jr., E. J. Hansen, and S. M. Spinola, mBio 5:e01081-13, 2014, http://dx.doi.org/10.1128/mBio.01081-13) suggested that H. ducreyi encounters growth conditions in human lesions resembling those found in stationary phase. However, how H. ducreyi transcriptionally responds to stress during human infection is unknown. Here, we determined the H. ducreyi transcriptome in biopsy specimens of human lesions and compared it to the transcriptomes of bacteria grown to mid-log, transition, and stationary phases. Multidimensional scaling showed that the in vivo transcriptome is distinct from those of in vitro growth. Compared to the inoculum (mid-log-phase bacteria), H. ducreyi harvested from pustules differentially expressed ∼93 genes, of which 62 were upregulated. The upregulated genes encode homologs of proteins involved in nutrient transport, alternative carbon pathways (l-ascorbate utilization and metabolism), growth arrest response, heat shock response, DNA recombination, and anaerobiosis. H. ducreyi upregulated few genes (hgbA, flp-tad, and lspB-lspA2) encoding virulence determinants required for human infection. Most genes regulated by CpxRA, RpoE, Hfq, (p)ppGpp, and DksA, which control the expression of virulence determinants and adaptation to a variety of stresses, were not differentially expressed in vivo, suggesting that these systems are cycling on and off during infection. Taken together, these data suggest that the in vivo transcriptome is distinct from those of in vitro growth and that adaptation to nutrient stress and anaerobiosis is crucial for H. ducreyi survival in humans. Copyright © 2016

  3. A modification of the Regional Nutrient Management model (ReNuMa) to identify long-term changes in riverine nitrogen sources

    Science.gov (United States)

    Hu, Minpeng; Liu, Yanmei; Wang, Jiahui; Dahlgren, Randy A.; Chen, Dingjiang

    2018-06-01

    Source apportionment is critical for guiding development of efficient watershed nitrogen (N) pollution control measures. The ReNuMa (Regional Nutrient Management) model, a semi-empirical, semi-process-oriented model with modest data requirements, has been widely used for riverine N source apportionment. However, the ReNuMa model contains limitations for addressing long-term N dynamics by ignoring temporal changes in atmospheric N deposition rates and N-leaching lag effects. This work modified the ReNuMa model by revising the source code to allow yearly changes in atmospheric N deposition and incorporation of N-leaching lag effects into N transport processes. The appropriate N-leaching lag time was determined from cross-correlation analysis between annual watershed individual N source inputs and riverine N export. Accuracy of the modified ReNuMa model was demonstrated through analysis of a 31-year water quality record (1980-2010) from the Yongan watershed in eastern China. The revisions considerably improved the accuracy (Nash-Sutcliff coefficient increased by ∼0.2) of the modified ReNuMa model for predicting riverine N loads. The modified model explicitly identified annual and seasonal changes in contributions of various N sources (i.e., point vs. nonpoint source, surface runoff vs. groundwater) to riverine N loads as well as the fate of watershed anthropogenic N inputs. Model results were consistent with previously modeled or observed lag time length as well as changes in riverine chloride and nitrate concentrations during the low-flow regime and available N levels in agricultural soils of this watershed. The modified ReNuMa model is applicable for addressing long-term changes in riverine N sources, providing decision-makers with critical information for guiding watershed N pollution control strategies.

  4. Local source impacts on primary and secondary aerosols in the Midwestern United States

    Science.gov (United States)

    Jayarathne, Thilina; Rathnayake, Chathurika M.; Stone, Elizabeth A.

    2016-04-01

    Atmospheric particulate matter (PM) exhibits heterogeneity in composition across urban areas, leading to poor representation of outdoor air pollutants in human exposure assessments. To examine heterogeneity in PM composition and sources across an urban area, fine particulate matter samples (PM2.5) were chemically profiled in Iowa City, IA from 25 August to 10 November 2011 at two monitoring stations. The urban site is the federal reference monitoring (FRM) station in the city center and the peri-urban site is located 8.0 km to the west on the city edge. Measurements of PM2.5 carbonaceous aerosol, inorganic ions, molecular markers for primary sources, and secondary organic aerosol (SOA) tracers were used to assess statistical differences in composition and sources across the two sites. PM2.5 mass ranged from 3 to 26 μg m-3 during this period, averaging 11.2 ± 4.9 μg m-3 (n = 71). Major components of PM2.5 at the urban site included organic carbon (OC; 22%), ammonium (14%), sulfate (13%), nitrate (7%), calcium (2.9%), and elemental carbon (EC; 2.2%). Periods of elevated PM were driven by increases in ammonium, sulfate, and SOA tracers that coincided with hot and dry conditions and southerly winds. Chemical mass balance (CMB) modeling was used to apportion OC to primary sources; biomass burning, vegetative detritus, diesel engines, and gasoline engines accounted for 28% of OC at the urban site and 24% of OC at the peri-urban site. Secondary organic carbon from isoprene and monoterpene SOA accounted for an additional 13% and 6% of OC at the urban and peri-urban sites, respectively. Differences in biogenic SOA across the two sites were associated with enhanced combustion activities in the urban area and higher aerosol acidity at the urban site. Major PM constituents (e.g., OC, ammonium, sulfate) were generally well-represented by a single monitoring station, indicating a regional source influence. Meanwhile, nitrate, biomass burning, food cooking, suspended dust, and

  5. Yttrium recovery from primary and secondary sources: A review of main hydrometallurgical processes

    Energy Technology Data Exchange (ETDEWEB)

    Innocenzi, Valentina, E-mail: valentina.innocenzi1@univaq.it [Department of Industrial Engineering, of Information and Economy, University of L’Aquila, Via Giovanni Gronchi 18, Zona industriale di Pile, 67100 L’Aquila (Italy); De Michelis, Ida [Department of Industrial Engineering, of Information and Economy, University of L’Aquila, Via Giovanni Gronchi 18, Zona industriale di Pile, 67100 L’Aquila (Italy); Kopacek, Bernd [SAT, Austrian Society for Systems Engineering and Automation, Gurkasse 43/2, A-1140 Vienna (Austria); Vegliò, Francesco [Department of Industrial Engineering, of Information and Economy, University of L’Aquila, Via Giovanni Gronchi 18, Zona industriale di Pile, 67100 L’Aquila (Italy)

    2014-07-15

    Highlights: • Review of the main hydrometallurgical processes to recover yttrium. • Recovery of yttrium from primary sources. • Recovery of yttrium from e-waste and other types of waste. - Abstract: Yttrium is important rare earths (REs) used in numerous fields, mainly in the phosphor powders for low-energy lighting. The uses of these elements, especially for high-tech products are increased in recent years and combined with the scarcity of the resources and the environmental impact of the technologies to extract them from ores make the recycling waste, that contain Y and other RE, a priority. The present review summarized the main hydrometallurgical technologies to extract Y from ores, contaminated solutions, WEEE and generic wastes. Before to discuss the works about the treatment of wastes, the processes to retrieval Y from ores are discussed, since the processes are similar and derived from those already developed for the extraction from primary sources. Particular attention was given to the recovery of Y from WEEE because the recycle of them is important not only for economical point of view, considering its value, but also for environmental impact that this could be generated if not properly disposal.

  6. Bioremediation of soil contaminated with hydrocarbons using sewage sludge as an alternative source of nutrients; Biorremediacion de suelo contaminado con hidrocarburos empleando lodos residuales como fuente alterna de nutrientes

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Prado, Adriana [Instituto Tecnologico de Durango, Durango, Durango (Mexico)]. E-mail: adriana.martinez@orst.edu; Perez Lopez, Ma. Elena [Centro Interdisciplinario de Investigacion para el Desarrollo Integral Regional (IPN-CIIDIR) Unidad Durango, Durango, Durango (Mexico); Pinto Espinoza, Joaquin; Gurrola Nevarez, Blanca Amelia; Osorio Rodriguez, Ana Lilia [Instituto Tecnologico de Durango, Durango, Durango (Mexico)

    2011-07-01

    In this research an aerobic bioremediation process, of a petroleum hydrocarbon contaminated soil, was evaluated using residual sludge (biosolids) from a local domestic wastewater treatment plant, as an alternative micro and macro nutrient source. Contamination of the soil resulted from accidental spills with hydrocarbons, mainly diesel, gasoline, and residual oils, from the San Antonio mining unit which belongs to Goldcorp Mexico Company, located in Tayoltita, from the municipality of San Dimas, Durango. Laboratory and pilot experiments were conducted, adjusting soil water content to field capacity and carbon:nitrogen (C:N) ratio to 10:1, evaluating the effect of addition of nutrients, density of the material being remediated, and the influence of soil particle size in the remediation process. It was demonstrated that the biosolids stimulated the native microorganisms of the polluted soil; consequently the hydrocarbon degradation process was accelerated. The hydrocarbons were used as carbon and electron donor source, coupling the oxidation-reduction reaction with oxygen which served as the electron acceptor. Treated soil was remediated and reached the maximum permissible limit (MPL), established in the Mexican current regulations (NOM-138-SEMARNAT/SS-2003), at both stages, and it is recommended as an optional process to the mining company to fulfill with the Clean Industry Program. [Spanish] En la presente investigacion se evaluo el proceso de biorremediacion aerobica de un suelo contaminado con hidrocarburos de petroleo empleando lodos residuales (biosolidos), provenientes de una planta de tratamiento de aguas residuales (PTAR) domesticas de la localidad, como fuente alterna de macro y micronutrientes. La contaminacion del suelo fue resultado de derrames accidentales de diesel, aceite y grasas en la unidad minera San Antonio perteneciente al grupo Goldcorp Mexico, ubicada en el municipio de San Dimas, en Tayoltita, Durango. Se realizaron experimentos a escala

  7. Effects of low pH on decomposition, primary production and nutrient recycling in the littoral zone. Effekter ev lav ph pa produksjon, nedbrytning og stoffkretslop i littoralsonen

    Energy Technology Data Exchange (ETDEWEB)

    Laake, M

    1976-01-01

    Field experiments were conducted in Tovdal, Southern Norway, to investigate the effects of low pH on decomposition, primary production and nutrient recycling in the littoral zone of softwater lakes. Sediment cores were incubated in throughflow boxes at pH 4, variable pH (4.5 to 5.6) and pH 6 at natural temperature conditions. One dark experiment with cores enriched with allochtonous material, and one natural light experiment with natural cores were conducted, lasting for 6 and 3 months respectively. The results show an overall reduction in decomposition with increasing acidity as measured by oxygen uptake and glucose turnover, although successions and adaptions occurred in enriched cores. Primary production of the flowering plant Lobelia dortmanna l. was inhibited at pH 4, while the acid conditions favoured epiphytic growth of the filamentous algae Mougeotia sp. turnover of phosphate reflected the activity of decomposers, while no pH-effect of phosphate uptake in plants was evident. Enriched cores developed heavy growth of ilamentous fungi at the surface, indicating a shift from bacterial to fungal decomposition with increasing acidity. More reduced conditions in sediments with increasing acidity were observed in some cases, which may be due to reduced oxygen diffusion through surface layers of gelatinous masses of fungi and bacteria. The results correlate very well with field observations of increased accumulation of organics and a reduction in macrophyte vegetation reported from Swedish lakes. It is concluded that the effects observed may have serious implications for the productivity in the littoral zone and in oligotrophic soft water lakes as a whole.

  8. Effects of different forage sources as a free-choice provision on the performance, nutrient digestibility, selected blood metabolites and structural growth of Holstein dairy calves.

    Science.gov (United States)

    Movahedi, B; Foroozandeh, A D; Shakeri, P

    2017-04-01

    The objective of this study was to determine the effects of different forage sources on the growth performance, nutrient digestibility and blood metabolites of dairy calves. Individually housed calves (n = 40; body weight = 41.2 ± 3.5 kg) were randomly allocated (n = 10 calves per treatment: five males and five females) to one of the following four treatments: (i) starter without forage provision (CON), (ii) starter plus chopped alfalfa hay (AH), (iii) starter plus chopped wheat straw (WS) and 4) starter plus dried sugar beet pulp (BP) flakes. Calves fed AH diets had lowest (p Digestibility of NDF and ADF was greater (p digestibility of DM and OM than those fed CON diets and similar to those fed AH and WS diets. Calves in the AH treatment had greater (p digestibility than CON, but similar to WS and BP calves. Blood beta-hydroxybutyrate concentration was lower in forage-offered calves than CON one. Body measurements (with the exception of body barrel) did not differ across treatments. It was concluded that BP improves final body weight, ADG and nutrient digestibility of calves than starter without forage provision during weaning transition. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

  9. Baseline water-quality sampling to infer nutrient and contaminant sources at Kaloko-Honokōhau National Historical Park, Island of Hawai‘i, 2009

    Science.gov (United States)

    Hunt, Charles D.

    2015-01-01

    ). Potential nutrient sources between the uplands and coastal lowlands that could contribute to enrichment include rock weathering, natural vegetation, fertilizers, septic leachate, and atmospheric deposition – including motor-vehicle exhaust.

  10. Development of a primary diffusion source of organic vapors for gas analyzer calibration

    Science.gov (United States)

    Lecuna, M.; Demichelis, A.; Sassi, G.; Sassi, M. P.

    2018-03-01

    The generation of reference mixtures of volatile organic compounds (VOCs) at trace levels (10 ppt-10 ppb) is a challenge for both environmental and clinical measurements. The calibration of gas analyzers for trace VOC measurements requires a stable and accurate source of the compound of interest. The dynamic preparation of gas mixtures by diffusion is a suitable method for fulfilling these requirements. The estimation of the uncertainty of the molar fraction of the VOC in the mixture is a key step in the metrological characterization of a dynamic generator. The performance of a dynamic generator was monitored over a wide range of operating conditions. The generation system was simulated by a model developed with computational fluid dynamics and validated against experimental data. The vapor pressure of the VOC was found to be one of the main contributors to the uncertainty of the diffusion rate and its influence at 10-70 kPa was analyzed and discussed. The air buoyancy effect and perturbations due to the weighing duration were studied. The gas carrier flow rate and the amount of liquid in the vial were found to play a role in limiting the diffusion rate. The results of sensitivity analyses were reported through an uncertainty budget for the diffusion rate. The roles of each influence quantity were discussed. A set of criteria to minimize the uncertainty contribution to the primary diffusion source (25 µg min-1) were estimated: carrier gas flow rate higher than 37.7 sml min-1, a maximum VOC liquid mass decrease in the vial of 4.8 g, a minimum residual mass of 1 g and vial weighing times of 1-3 min. With this procedure a limit uncertainty of 0.5% in the diffusion rate can be obtained for VOC mixtures at trace levels (10 ppt-10 ppb), making the developed diffusion vials a primary diffusion source with potential to become a new reference material for trace VOC analysis.

  11. Constraints on primary and secondary particulate carbon sources using chemical tracer and 14C methods during CalNex-Bakersfield

    Data.gov (United States)

    U.S. Environmental Protection Agency — The present study investigates primary and secondary sources of organic carbon for Bakersfield, CA, USA as part of the 2010 CalNex study. The method used here...

  12. Anaerobic treatment as a core technology for energy, nutrients and water from source-separated domestic waste(water)

    NARCIS (Netherlands)

    Zeeman, G.; Kujawa, K.; Mes, de T.Z.D.; Graaff, de M.S.; Abu-Ghunmi, L.N.A.H.; Mels, A.R.; Meulman, B.; Temmink, B.G.; Buisman, C.J.N.; Lier, van J.B.; Lettinga, G.

    2008-01-01

    Based on results of pilot scale research with source-separated black water (BW) and grey water (GW), a new sanitation concept is proposed. BW and GW are both treated in a UASB (-septic tank) for recovery of CH4 gas. Kitchen waste is added to the anaerobic BW treatment for doubling the biogas

  13. Chemical composition, true nutrient digestibility, and true metabolizable energy of novel pet food protein sources using the precision-fed cecectomized rooster assay.

    Science.gov (United States)

    Deng, P; Utterback, P L; Parsons, C M; Hancock, L; Swanson, K S

    2016-08-01

    A wide variety of animal protein-based ingredients is commonly used in the pet food products. The raw ingredients and processing procedures used may greatly affect protein quality. Testing the quality of alternative protein sources is necessary and contributes to the sustainability of pet foods. The objective of this study was to test the chemical composition of 8 protein sources intended for use in dog and cat foods (calamari meal, pork peptone, alligator meal, lamb meal, venison meal, chicken meal, and 2 duck meals), and evaluate their true nutrient digestibility and nitrogen-corrected true ME (TMEn) using the precision-fed cecectomized rooster assay. Calamari meal and pork peptone had lower ash (4.4 and 3.6% of DM, respectively) but greater CP (88.1 and 80.5% of DM, respectively) and either greater or similar GE (5.6 and 5.3 kcal/g of DM, respectively) compared with alligator, lamb, venison, chicken, and duck meals (11.8 to 24.5% ash, 58.7 to 65.9% CP, and 4.6 to 5.3 kcal GE/g). Acid-hydrolyzed fat (AHF) was lower in calamari meal (8.7% of DM) compared with the other proteins tested (15.5-22.1% of DM). True nutrient digestibility was variable among the protein sources (52 to 79% of DM, 60 to 83% of OM, 78 to 92% of AHF, and 70 to 89% of GE) with pork peptone having the highest DM, AHF, and GE digestibility and calamari meal having the highest OM digestibility. True indispensable AA digestibility was highest for calamari meal, with all AA having a digestibility greater than 90%. Except for histidine, all indispensable AA had a digestibility over 85% for pork peptone. In contrast, true indispensable AA digestibility was lowest for lamb meal, with histidine having digestibility less than 70% and the other entire indispensable AA having digestibility between 72 and 88%. The TMEn of calamari meal (4.82 kcal/g DM and 86.9% of GE) was greater ( digestibility among protein sources intended for use in dog and cat foods and justifies further in vivo testing of novel

  14. Effects of different external carbon sources and electron acceptors on interactions between denitrification and phosphorus removal in biological nutrient removal processes.

    Science.gov (United States)

    Hu, Xiang; Sobotka, Dominika; Czerwionka, Krzysztof; Zhou, Qi; Xie, Li; Makinia, Jacek

    The effects of two different external carbon sources (acetate and ethanol) and electron acceptors (dissolved oxygen, nitrate, and nitrite) were investigated under aerobic and anoxic conditions with non-acclimated process biomass from a full-scale biological nutrient removal-activated sludge system. When acetate was added as an external carbon source, phosphate release was observed even in the presence of electron acceptors. The release rates were 1.7, 7.8, and 3.5 mg P/(g MLVSS·h) (MLVSS: mixed liquor volatile suspended solids), respectively, for dissolved oxygen, nitrate, and nitrite. In the case of ethanol, no phosphate release was observed in the presence of electron acceptors. Results of the experiments with nitrite showed that approximately 25 mg NO 2 -N/L of nitrite inhibited anoxic phosphorus uptake regardless of the concentration of the tested external carbon sources. Furthermore, higher denitrification rates were obtained with acetate (1.4 and 0.8 mg N/(g MLVSS·h)) compared to ethanol (1.1 and 0.7 mg N/ (g MLVSS·h)) for both anoxic electron acceptors (nitrate and nitrite).

  15. Life cycle assessment of different strategies for energy and nutrient recovery from source sorted organic fraction of household waste

    DEFF Research Database (Denmark)

    Khoshnevisan, Benyamin; Tsapekos, Panagiotis; Alvarado-Morales, Merlin

    2018-01-01

    and different biogas applications. Biopulp technology, screw press, and disc screen were chosen as three available pretreatment methods and electricity production, combined heat and power (CHP) production, as well as biogas upgrading were selected as three downstream management strategies. In all scenarios...... obtained, it can be concluded that CHP production would be the best downstream management option while the results were so sensitive to the source of substituted energy....

  16. Possible Sources of Bias in Primary Care Electronic Health Record Data Use and Reuse.

    Science.gov (United States)

    Verheij, Robert A; Curcin, Vasa; Delaney, Brendan C; McGilchrist, Mark M

    2018-05-29

    Enormous amounts of data are recorded routinely in health care as part of the care process, primarily for managing individual patient care. There are significant opportunities to use these data for other purposes, many of which would contribute to establishing a learning health system. This is particularly true for data recorded in primary care settings, as in many countries, these are the first place patients turn to for most health problems. In this paper, we discuss whether data that are recorded routinely as part of the health care process in primary care are actually fit to use for other purposes such as research and quality of health care indicators, how the original purpose may affect the extent to which the data are fit for another purpose, and the mechanisms behind these effects. In doing so, we want to identify possible sources of bias that are relevant for the use and reuse of these type of data. This paper is based on the authors' experience as users of electronic health records data, as general practitioners, health informatics experts, and health services researchers. It is a product of the discussions they had during the Translational Research and Patient Safety in Europe (TRANSFoRm) project, which was funded by the European Commission and sought to develop, pilot, and evaluate a core information architecture for the learning health system in Europe, based on primary care electronic health records. We first describe the different stages in the processing of electronic health record data, as well as the different purposes for which these data are used. Given the different data processing steps and purposes, we then discuss the possible mechanisms for each individual data processing step that can generate biased outcomes. We identified 13 possible sources of bias. Four of them are related to the organization of a health care system, whereas some are of a more technical nature. There are a substantial number of possible sources of bias; very little is

  17. Radiation Protection Aspects of Primary Water Chemistry and Source-term Management Report

    International Nuclear Information System (INIS)

    2014-04-01

    Since the beginning of the 1990's, occupational exposures in nuclear power plant has strongly decreased, outlining efforts achieved by worldwide nuclear operators in order to reach and maintain occupational exposure as low as reasonably achievable (ALARA) in accordance with international recommendations and national regulations. These efforts have focused on both technical and organisational aspects. According to many radiation protection experts, one of the key features to reach this goal is the management of the primary system water chemistry and the ability to avoid dissemination of radioactivity within the system. It outlines the importance for radiation protection staff to work closely with chemistry staff (as well as operation staff) and thus to have sufficient knowledge to understand the links between chemistry and the generation of radiation field. This report was prepared with the primary objective to provide such knowledge to 'non-chemist'. The publication primarily focuses on three topics dealing with water chemistry, source term management and remediation techniques. One key objective of the report is to provide current knowledge regarding these topics and to address clearly related radiation protection issues. In that mind, the report prepared by the EGWC was also reviewed by radiation protection experts. In order to address various designs, PWRs, VVERs, PHWRs and BWRs are addressed within the document. Additionally, available information addressing current operating units and lessons learnt is outlined with choices that have been made for the design of new plants. Chapter 3 of this report addresses current practices regarding primary chemistry management for different designs, 'how to limit activity in the primary circuit and to minimise contamination'. General information is provided regarding activation, corrosion and transport of activated materials in the primary circuit (background on radiation field generation). Primary chemistry aspects that

  18. Nutrient Limitation in Central Red Sea Mangroves

    KAUST Repository

    Almahasheer, Hanan

    2016-12-24

    As coastal plants that can survive in salt water, mangroves play an essential role in large marine ecosystems (LMEs). The Red Sea, where the growth of mangroves is stunted, is one of the least studied LMEs in the world. Mangroves along the Central Red Sea have characteristic heights of ~2 m, suggesting nutrient limitation. We assessed the nutrient status of mangrove stands in the Central Red Sea and conducted a fertilization experiment (N, P and Fe and various combinations thereof) on 4-week-old seedlings of Avicennia marina to identify limiting nutrients and stoichiometric effects. We measured height, number of leaves, number of nodes and root development at different time periods as well as the leaf content of C, N, P, Fe, and Chl a in the experimental seedlings. Height, number of nodes and number of leaves differed significantly among treatments. Iron treatment resulted in significantly taller plants compared with other nutrients, demonstrating that iron is the primary limiting nutrient in the tested mangrove population and confirming Liebig\\'s law of the minimum: iron addition alone yielded results comparable to those using complete fertilizer. This result is consistent with the biogenic nature of the sediments in the Red Sea, which are dominated by carbonates, and the lack of riverine sources of iron.

  19. The temperature of primary melts and mantle sources of komatiites, OIBs, MORBs and LIPs

    Science.gov (United States)

    Sobolev, Alexander

    2015-04-01

    established liquidus temperatures and compositions of primary melts allow estimating potential temperatures and compositions of their mantle sources. The results strongly confirm mantle plume theory and presence of variable amounts of recycled crustal material in the mantle sources. This study has been founded by Russian Science Foundation grant 14-17-00491.

  20. Anaerobic treatment as a core technology for energy, nutrients and water recovery from source-separated domestic waste(water).

    Science.gov (United States)

    Zeeman, Grietje; Kujawa, Katarzyna; de Mes, Titia; Hernandez, Lucia; de Graaff, Marthe; Abu-Ghunmi, Lina; Mels, Adriaan; Meulman, Brendo; Temmink, Hardy; Buisman, Cees; van Lier, Jules; Lettinga, Gatze

    2008-01-01

    Based on results of pilot scale research with source-separated black water (BW) and grey water (GW), a new sanitation concept is proposed. BW and GW are both treated in a UASB (-septic tank) for recovery of CH4 gas. Kitchen waste is added to the anaerobic BW treatment for doubling the biogas production. Post-treatment of the effluent is providing recovery of phosphorus and removal of remaining COD and nitrogen. The total energy saving of the new sanitation concept amounts to 200 MJ/year in comparison with conventional sanitation, moreover 0.14 kg P/p/year and 90 litres of potential reusable water are produced. (c) IWA Publishing 2008.

  1. Scale-up of an alkaline protease from Bacillus pumilus MTCC 7514 utilizing fish meal as a sole source of nutrients.

    Science.gov (United States)

    Gupta, Rishikesh Kumar; Prasad, Dinesh; Sathesh, Jaykumar; Naidu, Ramachandra Boopathy; Kamini, Numbi Ramudu; Palanivel, Saravanan; Gowthaman, Marichetti Kuppuswami

    2012-09-01

    Fish meal grades SL1 and SL2 from Sardine (Sardinella longiceps) and NJ from Pink Perch (Nemipterus japonicas) were evaluated as a sole source of carbon and nitrogen in the medium for alkaline protease production by Bacillus pumilus MTCC 7514. The analysis of the fish meal suggests that the carbon and nitrogen contents in fish meal are sufficient to justify its choice as replacement for other nutrients. Protease production increased significantly (4,914 U/ml) in medium containing only fish meal, compared with the basal medium (2,646 U/ml). However, the elimination of inorganic salts from media reduced the protease productivity. In addition, all the three grades of fish meal yielded almost the same amounts of protease when employed as the sole source of carbon and nitrogen. Nevertheless, the best results were observed in fish meal SL1 medium. Furthermore, protease production was enhanced to 6,966 U/ml and 7,047 U/ml on scaling up from flask (4,914 U/ml) to 3.7 and 20 L fermenters, respectively, using fish meal (10 g/l). Similarly, the corresponding improvement in productivities over flask (102.38 U/ml/h) was 193.5 and 195.75 U/ml/h in 3.7 and 20 L fermenters, respectively. The crude protease was found to have dehairing ability in leather processing, which is bound to have great environmental benefits.

  2. Global change expedition : nutrient, chlorophyll-A and primary productivity data, NOAA ship Mt. Mitchell, 14 July-6 September 1988 (NODC Accession 9000187)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Nutrient data from NOAA'S Global Change Expedition in July-September 1988 was submitted by Dr. Dennis W. Frazel of RSMAS (University of Miami). The expedition was...

  3. Temperature, salinity, nutrient, primary production, and meteorological data collected by bottle in the South Pacific Ocean from 1/16/1962 - 8/2/1964 (NODC Accession 0000092)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile, nutrients, and other data were collected using net and bottle casts from the HUAYAIPE and ST JUDE in the South Pacific Ocean. Data were...

  4. The potential contribution of yellow cassava to dietary nutrient adequacy of primary-school children in Eastern Kenya; the use of linear programming

    OpenAIRE

    Talsma, Elise F.; Borgonjen-van den Berg, Karin J.; Melse-Boonstra, Alida; Mayer, Eva V.; Verhoef, Hans; Demir, Ayşe Y.; Ferguson, Elaine L.; Kok, Frans J.; Brouwer, Inge D.

    2018-01-01

    Objective: Introduction of biofortified cassava as school lunch can increase vitamin A intake, but may increase risk of other deficiencies due to poor nutrient profile of cassava. We assessed the potential effect of introducing a yellow cassava-based school lunch combined with additional food-based recommendations (FBR) on vitamin A and overall nutrient adequacy using Optifood (linear programming tool). Design: Cross-sectional study to assess dietary intakes (24 h recall) and derive model par...

  5. Seasonal Shifts in Primary Water Source Type: A Comparison of Largely Pastoral Communities in Uganda and Tanzania

    Directory of Open Access Journals (Sweden)

    Amber L. Pearson

    2016-01-01

    Full Text Available Many water-related illnesses show an increase during the wet season. This is often due to fecal contamination from runoff, yet, it is unknown whether seasonal changes in water availability may also play a role in increased illness via changes in the type of primary water source used by households. Very little is known about the dynamic aspects of access to water and changes in source type across seasons, particularly in semi-arid regions with annual water scarcity. The research questions in this study were: (1 To what degree do households in Uganda (UG and Tanzania (TZ change primary water source type between wet and dry seasons?; and (2 How might seasonal changes relate to water quality and health? Using spatial survey data from 92 households each in UG and TZ this study found that, from wet to dry season, 26% (UG and 9% (TZ of households switched from a source with higher risk of contamination to a source with lower risk. By comparison, only 20% (UG and 0% (TZ of households switched from a source with lower risk of contamination to a source with higher risk of contamination. This research suggests that one pathway through which water-related disease prevalence may differ across seasons is the use of water sources with higher risk contamination, and that households with access to sources with lower risks of contamination sometimes choose to use more contaminated sources.

  6. The particulate passage rate, nutrient composition and fermentation characteristics across gastrointestinal tracts in lactating dairy cows fed three different forage source diets.

    Science.gov (United States)

    Wang, B; Gu, F F; Huang, X B; Liu, J X

    2018-04-19

    This study was conducted to investigate the particulate passage rate, nutrient characteristics and fermentation parameters across the gastrointestinal tract (GIT) in lactating dairy cows fed cereal straws in comparison with alfalfa hay. Eighteen multiparous Holstein cows were randomly assigned to one of three experimental diets consisting of 55% concentrate, 15% corn silage and 30% different forage sources as follows (% of dry matter [DM]): (i) 23% alfalfa hay and 7% Chinese wild rye hay (AH); (ii) 30% corn stover (CS); and (iii) 30% rice straw (RS). The Cr-mordanted corn silage-neutral detergent fibre was used to estimate the passage flow at week 14. After 14-week feeding, the animals were slaughtered to collect the gastrointestinal digesta. Dietary forage sources had little effect on the fractional passage rates in the rumen (range from 5.05 to 6.25%/hr) or hindgut (range from 4.49 to 5.24%/hr). Total volatile fatty acid (VFA) concentration in the caecum was highest, followed by the rumen, colon and rectum, and the lowest in the abomasum and duodenum, indicating that the large intestines, especially caecum, are the important positions for carbohydrate degradation. Greater proportion of propionate and butyrate and lower acetate were found in the AH compared to CS or RS in colon, but higher acetate in abomasum was found in the cows fed CS or RS compared to AH. In conclusion, cereal straw diets did not change the particulate passage rate in the rumen and hindgut which might be mainly due to the similar DM intake among these three diets. Different forage source diets significantly changed VFA proportion in the abomasum and colon, indicating the existence of different digestion or absorption rates in these tracts among the experimental diets. © 2018 Blackwell Verlag GmbH.

  7. Effect of Carbohydrate Sources and Levels of Cotton Seed Meal in Concentrate on Feed Intake, Nutrient Digestibility, Rumen Fermentation and Microbial Protein Synthesis in Young Dairy Bulls

    Directory of Open Access Journals (Sweden)

    M. Wanapat

    2013-04-01

    Full Text Available The objective of this study was to investigate the effect of levels of cottonseed meal with various carbohydrate sources in concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in dairy bulls. Four, 6 months old dairy bulls were randomly assigned to receive four dietary treatments according to a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was carbohydrate source; cassava chip (CC and cassava chip+rice bran in the ratio of 3:1 (CR3:1, and factor B was cotton seed meal levels in the concentrate; 109 g CP/kg (LCM and 328 g CP/kg (HCM at similar overall CP levels (490 g CP/kg. Bulls received urea-lime treated rice straw ad libitum and were supplemented with 10 g of concentrate/kg BW. It was found that carbohydrate source and level of cotton seed meal did not have significant effects on ruminal pH, ammonia nitrogen concentration, microbial protein synthesis or feed intake. Animals which received CC showed significantly higher BUN concentration, ruminal propionic acid and butyric acid proportions, while dry matter, organic matter digestibility, populations of total viable bacteria and proteolytic bacteria were lower than those in the CR3:1 treatment. The concentration of total volatile fatty acids was higher in HCM than LCM treatments, while the concentration of butyric acid was higher in LCM than HCM treatments. The population of proteolytic bacteria with the LCM treatments was higher than the HCM treatments; however other bacteria groups were similar among the different levels of cotton seed meal. Bulls which received LCM had higher protein digestibility than those receiving HCM. Therefore, using high levels of cassava chip and cotton seed meal might positively impact on energy and nitrogen balance for the microbial population in the rumen of the young dairy bull.

  8. Nutrient Digestibility, Rumen Fermentation Parameters, and Production Performance in Response to Dietary Grain Source and Oil Supplement of Holstein Dairy Cows

    Directory of Open Access Journals (Sweden)

    Shahryar Kargar

    2016-04-01

    Full Text Available Introduction High-producing dairy cows require large amounts of concentrates that are rich in energy and crude protein to meet their nutrient requirements. Cereal grains and oil supplements are commonly used for increasing energy density of diets fed to high-producing dairy cows. Dietary grain source (barley vs. corn and oil supplement (soybean- vs. fish oil resulted in varied dry matter intake and milk production responses in different research studies based on effects on nutrient digestibility and rumen fermentation characteristics. Therefore, the main purpose of this study was to determine the effects of, and interactions between, grain source and oil supplement on the feed intake, rumen fermentation characteristics, nutrient digestibility and lactational performance of Holstein cows. Materials and Methods Eight lactating multiparous Holstein cows (parity = 3.3 ± 1.3 and days in milk = 77 ± 22.1; mean ± SD, were used in a replicated 4 × 4 Latin square design with 25-d periods. Each experimental period consisted of an 18-d diet adaptation period and a 7-d collection period. Cows within a square were assigned randomly to dietary treatments. Cows were blocked into 2 squares of 4 cows each based upon milk production, and days in milk, and within blocks were assigned to 1 of the 4 experimental diets with a 2 × 2 factorial arrangement: 1 BF = barley-based diet supplemented with fish oil at 2% of dietary DM, 2 BS = barley-based diet supplemented with soybean oil at 2% of dietary DM, 3 CF = corn-based diet supplemented with fish oil at 2% of dietary DM, and 4 CS = corn-based diet supplemented with soybean oil at 2% of dietary DM. The TMR amounts offered and refused were measured daily for each cow and DMI determined daily for each cow. Cows were milked three times daily at 0200, 1000, and 1800 h in a herringbone milking parlor. Milk yield for all cows was recorded and sampled at each milking during the last 7 d of each period. Milk samples were

  9. Parents’ Primary Professional Sources of Parenting Advice Moderate Predictors of Parental Attitudes toward Corporal Punishment

    Science.gov (United States)

    Taylor, Catherine A.; McKasson, Sarah; Hoy, Guenevere; DeJong, William

    2016-01-01

    Despite the risk it poses to children’s mental and physical health, approval and use of corporal punishment (CP) remains high in the United States. Informed by the Theory of Planned Behavior, we examined potential predictors of attitudes supportive of CP while assessing the moderating effects of parents’ (N=500) chosen primary professional source of advice regarding child discipline: pediatricians (47.8%), religious leaders (20.8%), mental health professionals (MHPs) (n=18.4%), or other identified professionals (13.0%). We conducted a random-digit-dial telephone survey among parents ages 18 and over within New Orleans, LA. The main outcome measure was derived from the Attitudes Toward Spanking scale (ATS). The main “predictors” were: perceived injunctive norms (i.e., perceived approval of CP by professionals; and by family and friends), perceived descriptive norms of family and friends regarding CP, and expected outcomes of CP use. We used multivariate OLS models to regress ATS scores on the predictor variables for each subset of parents based on their chosen professional source of advice. Perceived approval of CP by professionals was the strongest predictor of parental attitudes supportive of CP, except for those seeking advice from MHPs. Perceived injunctive and descriptive norms of family and friends were important, but only for those seeking advice from pediatricians or religious leaders. Positive expected outcomes of CP mattered, but only for those seeking advice from religious leaders or MHPs. In conclusion, the strength and relevance of variables predicting attitudes toward CP varied according to the professional from which the parent was most likely to seek advice. PMID:28529440

  10. Parents' Primary Professional Sources of Parenting Advice Moderate Predictors of Parental Attitudes toward Corporal Punishment.

    Science.gov (United States)

    Taylor, Catherine A; McKasson, Sarah; Hoy, Guenevere; DeJong, William

    2017-02-01

    Despite the risk it poses to children's mental and physical health, approval and use of corporal punishment (CP) remains high in the United States. Informed by the Theory of Planned Behavior, we examined potential predictors of attitudes supportive of CP while assessing the moderating effects of parents' (N=500) chosen primary professional source of advice regarding child discipline: pediatricians (47.8%), religious leaders (20.8%), mental health professionals (MHPs) (n=18.4%), or other identified professionals (13.0%). We conducted a random-digit-dial telephone survey among parents ages 18 and over within New Orleans, LA. The main outcome measure was derived from the Attitudes Toward Spanking scale (ATS). The main "predictors" were: perceived injunctive norms (i.e., perceived approval of CP by professionals; and by family and friends), perceived descriptive norms of family and friends regarding CP, and expected outcomes of CP use. We used multivariate OLS models to regress ATS scores on the predictor variables for each subset of parents based on their chosen professional source of advice. Perceived approval of CP by professionals was the strongest predictor of parental attitudes supportive of CP, except for those seeking advice from MHPs. Perceived injunctive and descriptive norms of family and friends were important, but only for those seeking advice from pediatricians or religious leaders. Positive expected outcomes of CP mattered, but only for those seeking advice from religious leaders or MHPs. In conclusion, the strength and relevance of variables predicting attitudes toward CP varied according to the professional from which the parent was most likely to seek advice.

  11. Primary and secondary aerosols in Beijing in winter: sources, variations and processes

    Science.gov (United States)

    Sun, Yele; Du, Wei; Fu, Pingqing; Wang, Qingqing; Li, Jie; Ge, Xinlei; Zhang, Qi; Zhu, Chunmao; Ren, Lujie; Xu, Weiqi; Zhao, Jian; Han, Tingting; Worsnop, Douglas R.; Wang, Zifa

    2016-07-01

    Winter has the worst air pollution of the year in the megacity of Beijing. Despite extensive winter studies in recent years, our knowledge of the sources, formation mechanisms and evolution of aerosol particles is not complete. Here we have a comprehensive characterization of the sources, variations and processes of submicron aerosols that were measured by an Aerodyne high-resolution aerosol mass spectrometer from 17 December 2013 to 17 January 2014 along with offline filter analysis by gas chromatography/mass spectrometry. Our results suggest that submicron aerosols composition was generally similar across the winter of different years and was mainly composed of organics (60 %), sulfate (15 %) and nitrate (11 %). Positive matrix factorization of high- and unit-mass resolution spectra identified four primary organic aerosol (POA) factors from traffic, cooking, biomass burning (BBOA) and coal combustion (CCOA) emissions as well as two secondary OA (SOA) factors. POA dominated OA, on average accounting for 56 %, with CCOA being the largest contributor (20 %). Both CCOA and BBOA showed distinct polycyclic aromatic hydrocarbons (PAHs) spectral signatures, indicating that PAHs in winter were mainly from coal combustion (66 %) and biomass burning emissions (18 %). BBOA was highly correlated with levoglucosan, a tracer compound for biomass burning (r2 = 0.93), and made a considerable contribution to OA in winter (9 %). An aqueous-phase-processed SOA (aq-OOA) that was strongly correlated with particle liquid water content, sulfate and S-containing ions (e.g. CH2SO2+) was identified. On average aq-OOA contributed 12 % to the total OA and played a dominant role in increasing oxidation degrees of OA at high RH levels (> 50 %). Our results illustrate that aqueous-phase processing can enhance SOA production and oxidation states of OA as well in winter. Further episode analyses highlighted the significant impacts of meteorological parameters on aerosol composition, size

  12. Nutrient acquisition strategies of mammalian cells.

    Science.gov (United States)

    Palm, Wilhelm; Thompson, Craig B

    2017-06-07

    Mammalian cells are surrounded by diverse nutrients, such as glucose, amino acids, various macromolecules and micronutrients, which they can import through transmembrane transporters and endolysosomal pathways. By using different nutrient sources, cells gain metabolic flexibility to survive periods of starvation. Quiescent cells take up sufficient nutrients to sustain homeostasis. However, proliferating cells depend on growth-factor-induced increases in nutrient uptake to support biomass formation. Here, we review cellular nutrient acquisition strategies and their regulation by growth factors and cell-intrinsic nutrient sensors. We also discuss how oncogenes and tumour suppressors promote nutrient uptake and thereby support the survival and growth of cancer cells.

  13. N sources affect growth, nutrient content, and net photosynthesis in maté (Ilex paraguariensis St. Hil.

    Directory of Open Access Journals (Sweden)

    Sérgio Gaiad

    2006-09-01

    Full Text Available The influence of different N sources on the growth of maté (Ilex paragurariensis St.Hil. seedlings grown in greenhouse was studied. All seedlings received a base fertilization of 10 mg N.kg-1 soil as NH4NO3, 60 mg P2O5.and 40 mg K2O.kg-1 soil as KH2PO4 15 days before treatments application. Treatments were as follow: Control, with no extra N added; Urea = 100 mg N.kg-1 soil as Urea; NO3- = 100 mg N.kg-1 soil as Ca(NO32; and NH4+ = 100 mg N.kg-1 soil as (NH42SO4. It was concluded that: 1 increasing N content in leaves alone was not able to promote gain in biomass production of maté seedlings; 2 seedlings receiving N-NH4 showed a higher accumulation of P and Mg on shoot biomass; and 3 an increase in leaf area, leaf number and net photosynthesis observed at the N-NH4 treatment was coincident with an increasing absorption of P and Mg.A influência de diferentes fontes de N sobre o crescimento de mudas de erva-mate (Ilex paraguariensis St.Hil. foi estudada, em casa de vegetação. Todas as mudas receberam uma fertilização base de 10 mg N.kg-1 de solo na forma de NH4NO3, 60 mg P2O5.kg-1 e 40 mg K2O.kg-1 de solo na forma de KH2PO4 quinze dias antes da aplicação dos tratamentos. Os tratamentos foram os seguintes: Controle, sem adição extra de N; Uréia = 100 mg N.kg-1 de solo como Uréia; NO3- = 100 mg N.kg-1 de solo como Ca(NO32; e NH4+ = 100 mg N.kg-1 de solo como (NH42SO4. Concluiu-se que: 1 o aumento do conteúdo de N nas folhas, por si, não é capaz de promover ganhos na produção de biomassa em mudas de erva-mate; 2 mudas que receberam N-NH4 apresentaram maior acumulo de P e Mg na biomassa aérea; e 3 o aumento na absorção de P e Mg coincidiu com um aumento na área foliar, no número de folhas e na fotossíntese liquida na fonte N-NH4.

  14. Stress Sources and Manifestations in a Nationwide Sample of Pre-Primary, Primary, and Secondary Educators in Greece

    OpenAIRE

    Kourmousi, Ntina; Alexopoulos, Evangelos C.

    2016-01-01

    Background Teachers experience high levels of stress as a result of their professional duties, and research has shown a growing interest in this phenomenon during the recent years. Aim of this study was to explore the associations of stress sources and manifestations with individual and job-related characteristics in educators of all levels. Methods In a cross-sectional design, following an informative e-campaign on the study aims through the official and the main teachers’ portals...

  15. Synergistic effect of multiple indoor allergen sources on atopic symptoms in primary school children

    International Nuclear Information System (INIS)

    Chen, W-Y.; Tseng, H-I.; Wu, M-T.; Hung, H-C.; Wu, H-T.; Chen, H-L.; Lu, C.-C.

    2003-01-01

    Accumulating data show that the complex modern indoor environment contributes to increasing prevalence of atopic diseases. However, the dose-response relationship between allergic symptoms and complexity of indoor environmental allergen sources (IEAS) has not been clearly evaluated before. Therefore, we designed this study to investigate the overall effect of multiple IEAS on appearance of asthma (AS), allergic rhinitis (AR), and eczema (EC) symptoms in 1472 primary school children. Among various IEAS analyzed, only stuffed toys, cockroaches, and mold patches fit the model of 'more IEAS, higher odds ratio (OR) of association'. The association of IEAS and AR increased stepwise as more IEAS appeared in the environment (1.71, 2.47, to 2.86). In AS and EC, the association was significant only when all three IEAS were present (1.42, 1.98, to 4.11 in AS; 1.40, 1.76, to 2.95 in EC). These results showed that different IEAS had a synergistic effect on their association with atopic symptoms and also suggest that there is a dose-response relationship between kinds of IEAS and risk of appearance of atopic diseases

  16. Human Rights Texts: Converting Human Rights Primary Source Documents into Data.

    Science.gov (United States)

    Fariss, Christopher J; Linder, Fridolin J; Jones, Zachary M; Crabtree, Charles D; Biek, Megan A; Ross, Ana-Sophia M; Kaur, Taranamol; Tsai, Michael

    2015-01-01

    We introduce and make publicly available a large corpus of digitized primary source human rights documents which are published annually by monitoring agencies that include Amnesty International, Human Rights Watch, the Lawyers Committee for Human Rights, and the United States Department of State. In addition to the digitized text, we also make available and describe document-term matrices, which are datasets that systematically organize the word counts from each unique document by each unique term within the corpus of human rights documents. To contextualize the importance of this corpus, we describe the development of coding procedures in the human rights community and several existing categorical indicators that have been created by human coding of the human rights documents contained in the corpus. We then discuss how the new human rights corpus and the existing human rights datasets can be used with a variety of statistical analyses and machine learning algorithms to help scholars understand how human rights practices and reporting have evolved over time. We close with a discussion of our plans for dataset maintenance, updating, and availability.

  17. The Use of Energy in Malaysia: Tracing Energy Flows from Primary Source to End Use

    Directory of Open Access Journals (Sweden)

    Chinhao Chong

    2015-04-01

    Full Text Available Malaysia is a rapidly developing country in Southeast Asia that aims to achieve high-income country status by 2020; its economic growth is highly dependent on its abundant energy resources, especially natural gas and crude oil. In this paper, a complete picture of Malaysia’s energy use from primary source to end use is presented by mapping a Sankey diagram of Malaysia’s energy flows, together with ongoing trends analysis of the main factors influencing the energy flows. The results indicate that Malaysia’s energy use depends heavily on fossil fuels, including oil, gas and coal. In the past 30 years, Malaysia has successfully diversified its energy structure by introducing more natural gas and coal into its power generation. To sustainably feed the rapidly growing energy demand in end-use sectors with the challenge of global climate change, Malaysia must pay more attention to the development of renewable energy, green technology and energy conservation in the future.

  18. Electric vehicles, primary energy sources and CO2 emissions: Romanian case study

    International Nuclear Information System (INIS)

    Varga, Bogdan Ovidiu

    2013-01-01

    Starting on the 24th of April, 2011, the Romanian government offered to subsidize all potential buyers of electric vehicles, both private and corporate, offering 25% off of the retail price up to 5000 euros with no pollution tax. The Romanian government encourages all governmental institutions to consider buying electric vehicles when deciding to change their existing vehicles stock. This decision is strictly related to the Romanian government's approval of a long-term Energy Strategy, building on the National Energy Strategy for the Medium Term. The government's strategy emphasizes increasing energy efficiency and boosting renewable energy use. The first electric vehicles distributed in the Romanian market are the Citroen-C-Zero, the Mitsubishi i-MiEV, the Renault Kangoo Z.E. and the Renault Fluence Z.E. The energy consumption of these vehicles was analyzed, considering the CO 2 generation characteristics of a Romanian electric power plant. -- Highlights: ► Tax and governmental support for electrical vehicles in Romania. ► Evaluate the CO 2 pollution of the electrical vehicles in Romania's case. ► Comprehensive understanding of the influence of primary energy source over the pollution of an electrical vehicle. ► Approach to decrees the pollution of the electrical vehicles.

  19. Primary source of income is associated with differences in HIV risk behaviors in street-recruited samples.

    Science.gov (United States)

    Essien, E James; Ross, Michael W; Williams, Mark L; Meshack, Angela F; Fernández-Esquer, Maria E; Peters, Ronald J; Ogungbade, GO

    2004-06-17

    BACKGROUND: The relationship between primary source of income and HIV risk behaviors and the racial/ethnic differences in risk behavior profiles among disadvantaged populations have not been fully explored. This is unusual given that the phenomenon of higher risk in more disadvantaged populations is well-known but the mechanisms remain unclear. We examined the relationship between primary source of income and differences in HIV risk behaviors among four racial/ethnic groups in the southern United States. METHODS: Self-reported data on primary source of income and HIV risk behaviors were collected from 1494 African American, Hispanic, Asian, and White men and women in places of public congregation in Houston, Texas. Data were analyzed using calculation of percentages and by chi-square tests with Yates correction for discontinuity where appropriate. RESULTS: Data revealed that a higher proportion of whites were involved in sex for money exchanges compared to the other racial groups in this sample. The data suggest that similar street sampling approaches are likely to recruit different proportions of people by primary income source and by ethnicity. It may be that the study locations sampled are likely to preferentially attract those involved in illegal activities, specifically the white population involved in sex for drug or money exchanges. Research evidence has shown that people construct highly evolved sexual marketplaces that are localized and most unlikely to cross racial, ethnic, and socioeconomic or geographical boundaries. Thus, the areas that we sampled may have straddled a white sexual marketplace more than that of the other groups, leading to an over-representation of sex exchange in this group. Drug use was highest among those with illegal primary sources of income (sex exchange and drug dealing and theft), and they were also those most likely to have injected drugs rather than administered them by any other route (p primary source of income category. The

  20. Synthesis of Copper-Chelates Derived from Amino Acids and Evaluation of Their Efficacy as Copper Source and Growth Stimulator for Lactuca sativa in Nutrient Solution Culture.

    Science.gov (United States)

    Kaewchangwat, Narongpol; Dueansawang, Sattawat; Tumcharern, Gamolwan; Suttisintong, Khomson

    2017-11-15

    Five tetradentate ligands were synthesized from l-amino acids and utilized for the synthesis of Cu(II)-chelates 1-5. The efficacy of Cu(II)-chelates as copper (Cu) source and growth stimulator in hydroponic cultivation was evaluated with Lactuca sativa. Their stability test was performed at pH 4-10. The results suggested that Cu(II)-chelate 3 is the most pH tolerant complex. Levels of Cu, Zn, and Fe accumulated in plants supplied with Cu(II)-chelates were compared with those supplied with CuSO 4 at the same Cu concentration of 8.0 μM. The results showed that Cu(II)-chelate 3 significantly enhanced Cu, Zn, and Fe content in shoot by 35, 15, and 48%, respectively. Application of Cu(II)-chelate 3 also improved plant dry matter yield by 54%. According to the results, Cu(II)-chelate 3 demonstrated the highest stimulating effect on plant growth and plant mineral accumulation so that it can be used as an alternative to CuSO 4 for supplying Cu in nutrient solutions and enhancing the plant growth.

  1. Influence of source and micronization of soya bean meal on growth performance, nutrient digestibility and ileal mucosal morphology of Iberian piglets.

    Science.gov (United States)

    Berrocoso, J D; Cámara, L; Rebollar, P G; Guzmán, P; Mateos, G G

    2014-04-01

    The effects of inclusion in the diet of different sources of soya bean meal (SBM) on growth performance, total tract apparent digestibility (TTAD) and apparent ileal digestibility (AID) of major dietary components and mucosal ileum morphology were studied in Iberian pigs weaned at 30 days of age. From 30 to 51 days of age (phase I), there was a control diet based on regular soya bean meal (R-SBM; 44% CP) of Argentina (ARG) origin and five extra diets in which a high-protein soya bean meal (HP-SBM; 49% CP) of the USA or ARG origin, either ground (990 μm) or micronized (60 μm), or a soya protein concentrate (SPC; 65% CP) substituted the R-SBM. From 51 to 61 days of age (phase II), all pigs were fed a common commercial diet in mash form. The following pre-planned orthogonal contrasts were conducted: (1) R-SBM v. all the other diets, (2) SPC v. all the HP-SBM diets, (3) micronized HP-SBM v. ground HP-SBM, (4) HP-SBM of ARG origin v. HP-SBM of US origin and (5) interaction between source and the degree of grinding of the HP-SBM. Dietary treatment did not affect growth performance of the pigs at any age but from 30 to 51 days of age, post weaning diarrhoea (PWD) was higher (Psoya products (micronized SBM or SPC) in substitution of the R-SBM increased the TTAD of all nutrients and reduced PWD but had no advantage in terms of growth performance over the use of ground HP-SBM.

  2. Sources and delivery of carbon, nitrogen, and phosphorus to the coastal zone: An overview of global Nutrient Export from Watersheds (NEWS) models and their application

    NARCIS (Netherlands)

    Seitzinger, S.P.; Harrison, J.A.; Dumont, E.L.; Beusen, A.H.W.; Bouwman, A.F.

    2005-01-01

    An overview of the first spatially explicit, multielement (N, P, and C), multiform (dissolved inorganic: DIN, DIP; dissolved organic: DOC, DON, DOP; and particulate: POC, PN, PP) predictive model system of river nutrient export from watersheds (Global Nutrient Export from Watersheds (NEWS)) is

  3. Food sources of total energy and overconsumed nutrients of public health concern among US adolescents: National Health and Nutrition Examination Survey 2011-2014

    Science.gov (United States)

    There is high intake of energy and overconsumed nutrients of public health concern in adolescents' diet. Overconsumed nutrients are sodium, saturated fatty acids (SFA), and added sugars. Our objective was to identify the most commonly consumed foods by adolescents as percentage of total energy, tota...

  4. Primary and secondary aerosols in Beijing in winter: sources, variations and processes

    Directory of Open Access Journals (Sweden)

    Y. Sun

    2016-07-01

    Full Text Available Winter has the worst air pollution of the year in the megacity of Beijing. Despite extensive winter studies in recent years, our knowledge of the sources, formation mechanisms and evolution of aerosol particles is not complete. Here we have a comprehensive characterization of the sources, variations and processes of submicron aerosols that were measured by an Aerodyne high-resolution aerosol mass spectrometer from 17 December 2013 to 17 January 2014 along with offline filter analysis by gas chromatography/mass spectrometry. Our results suggest that submicron aerosols composition was generally similar across the winter of different years and was mainly composed of organics (60 %, sulfate (15 % and nitrate (11 %. Positive matrix factorization of high- and unit-mass resolution spectra identified four primary organic aerosol (POA factors from traffic, cooking, biomass burning (BBOA and coal combustion (CCOA emissions as well as two secondary OA (SOA factors. POA dominated OA, on average accounting for 56 %, with CCOA being the largest contributor (20 %. Both CCOA and BBOA showed distinct polycyclic aromatic hydrocarbons (PAHs spectral signatures, indicating that PAHs in winter were mainly from coal combustion (66 % and biomass burning emissions (18 %. BBOA was highly correlated with levoglucosan, a tracer compound for biomass burning (r2 = 0.93, and made a considerable contribution to OA in winter (9 %. An aqueous-phase-processed SOA (aq-OOA that was strongly correlated with particle liquid water content, sulfate and S-containing ions (e.g. CH2SO2+ was identified. On average aq-OOA contributed 12 % to the total OA and played a dominant role in increasing oxidation degrees of OA at high RH levels (> 50 %. Our results illustrate that aqueous-phase processing can enhance SOA production and oxidation states of OA as well in winter. Further episode analyses highlighted the significant impacts of meteorological parameters on

  5. Cost drivers for voluntary medical male circumcision using primary source data from sub-Saharan Africa.

    Science.gov (United States)

    Bollinger, Lori; Adesina, Adebiyi; Forsythe, Steven; Godbole, Ramona; Reuben, Elan; Njeuhmeli, Emmanuel

    2014-01-01

    As voluntary medical male circumcision (VMMC) programs scale up, there is a pressing need for information about the important cost drivers, and potential efficiency gains. We examine those cost drivers here, and estimate the potential efficiency gains through an econometric model. We examined the main cost drivers (i.e., personnel and consumables) associated with providing VMMC in sub-Saharan Africa along a number of dimensions, including facility type and service provider. Primary source facility level data from Kenya, Namibia, South Africa, Tanzania, Uganda, and Zambia were utilized throughout. We estimated the efficiency gains by econometrically estimating a cost function in order to calculate the impact of scale and other relevant factors. Personnel and consumables were estimated at 36% and 28%, respectively, of total costs across countries. Economies of scale (EOS) is estimated to be eight at the median volume of VMMCs performed, and EOS falls from 23 at the 25th percentile volume of VMMCs performed to 5.1 at the 75th percentile. The analysis suggests that there is significant room for efficiency improvement as indicated by declining EOS as VMMC volume increases. The scale of the fall in EOS as VMMC volume increases suggests that we are still at the ascension phase of the scale-up of VMMC, where continuing to add new sites results in additional start-up costs as well. A key aspect of improving efficiency is task sharing VMMC procedures, due to the large percentage of overall costs associated with personnel costs. In addition, efficiency improvements in consumables are likely to occur over time as prices and distribution costs decrease.

  6. Cost drivers for voluntary medical male circumcision using primary source data from sub-Saharan Africa.

    Directory of Open Access Journals (Sweden)

    Lori Bollinger

    Full Text Available As voluntary medical male circumcision (VMMC programs scale up, there is a pressing need for information about the important cost drivers, and potential efficiency gains. We examine those cost drivers here, and estimate the potential efficiency gains through an econometric model.We examined the main cost drivers (i.e., personnel and consumables associated with providing VMMC in sub-Saharan Africa along a number of dimensions, including facility type and service provider. Primary source facility level data from Kenya, Namibia, South Africa, Tanzania, Uganda, and Zambia were utilized throughout. We estimated the efficiency gains by econometrically estimating a cost function in order to calculate the impact of scale and other relevant factors. Personnel and consumables were estimated at 36% and 28%, respectively, of total costs across countries. Economies of scale (EOS is estimated to be eight at the median volume of VMMCs performed, and EOS falls from 23 at the 25th percentile volume of VMMCs performed to 5.1 at the 75th percentile.The analysis suggests that there is significant room for efficiency improvement as indicated by declining EOS as VMMC volume increases. The scale of the fall in EOS as VMMC volume increases suggests that we are still at the ascension phase of the scale-up of VMMC, where continuing to add new sites results in additional start-up costs as well. A key aspect of improving efficiency is task sharing VMMC procedures, due to the large percentage of overall costs associated with personnel costs. In addition, efficiency improvements in consumables are likely to occur over time as prices and distribution costs decrease.

  7. Context-dependent effects of nutrient loading on the coral-algal mutualism.

    Science.gov (United States)

    Shantz, Andrew A; Burkepile, Deron E

    2014-07-01

    Human-mediated increases in nutrient availability alter patterns of primary production, impact species diversity, and threaten ecosystem function. Nutrients can also alter community structure by disrupting the relationships between nutrient-sharing mutualists that form the foundation of communities. Given their oligotrophic nature and the dependence of reef-building corals on symbiotic relationships, coral reefs may be particularly vulnerable to excess nutrients. However, individual studies suggest complex, even contradictory, relationships among nutrient availability, coral physiology, and coral growth. Here, we used meta-analysis to establish general patterns of the impact of nitrogen (N) and phosphorus (P) on coral growth and photobiology. Overall, we found that over a wide range of concentrations, N reduced coral calcification 11%, on average, but enhanced metrics of coral photobiology, such as photosynthetic rate. In contrast, P enrichment increased average calcification rates by 9%, likely through direct impacts on the calcification process, but minimally impacted coral photobiology. There were few synergistic impacts of combined N and P on corals, as the nutrients impact corals via different pathways. Additionally, the response of corals to increasing nutrient availability was context dependent, varying with coral taxa and morphology, enrichment source, and nutrient identity. For example, naturally occurring enrichment from fish excretion increased coral growth, while human-mediated enrichment tended to decrease coral growth. Understanding the nuances of the relationship between nutrients and corals may allow for more targeted remediation strategies and suggest how other global change drivers such as overfishing and climate change will shape how nutrient availability impacts corals.

  8. The potential contribution of yellow cassava to dietary nutrient adequacy of primary-school children in Eastern Kenya; the use of linear programming

    NARCIS (Netherlands)

    Talsma, Elise F.; Borgonjen-van den Berg, Karin J.; Melse-Boonstra, Alida; Mayer, Eva V.; Verhoef, Hans; Demir, Ayşe Y.; Ferguson, Elaine L.; Kok, Frans J.; Brouwer, Inge D.

    2018-01-01

    Objective: Introduction of biofortified cassava as school lunch can increase vitamin A intake, but may increase risk of other deficiencies due to poor nutrient profile of cassava. We assessed the potential effect of introducing a yellow cassava-based school lunch combined with additional

  9. The World of Barilla Taylor: A Primary Source-Based Kit for Students in Grades 8-12.

    Science.gov (United States)

    Fellner, Kelly; Stearns, Liza

    1995-01-01

    Examines a primary source-based kit that describes the life of a young woman factory worker in early 19th-century New England. The kit includes five document sets, utilizing maps, newspaper articles, deeds, letters, poems, and other artifacts. The document sets illustrate various topics including mill life and personal life. (MJP)

  10. "There Was a Great Collision in the Stock Market": Middle School Students, Online Primary Sources, and Historical Sense Making.

    Science.gov (United States)

    Harris, Frances Jacobson

    2002-01-01

    Describes an exploratory study of eighth-grade students and their use of online primary sources for an oral history unit on family farming. Highlights include using photographs from the Depression era to write stories; use of bibliographic information; higher level thinking skills; use of humor; and implications for secondary social studies and…

  11. Avaliação do Lithothamnium como corretivo da acidez do solo e fonte de nutrientes para o feijoeiro Evaluation of lithothamnium as corrective of soil acidity and source of nutrients for bean plants

    Directory of Open Access Journals (Sweden)

    Paulo César de Melo

    2003-06-01

    -se que as menores doses de Lithothamnium, nos três solos, foram as que apresentaram melhores resultados nas características avaliadas e que os melhores resultados foram encontrados no LVd.With the objective of evaluating the efficiency of lithothamnium in the correction of the soil acidity and as source of nutrients for bean plants, an experiment was conducted in vases, in greenhouse conditions. The experimental design was a complete randomized one, with nine treatments: control, four doses of lithothamnium (1/4, 1/2, 1 and 2 times the dose for V at 70%, commercial dolomite limestone as reference pattern (dose for V at 70%, lithothamnium (V at 70% without micronutrients, lithothamnium (V at 70% with reduction of 20% of NPK and lithothamnium (V at 70% plus Mg. Three soil classes were evaluated, Quartzarenic (NQ, Yellow Red Latossol (LV and Red Argissol (AV, with four repetitions for each treatment. Four bean plants were cultivated in vases with three dm3. Two of these plants were harvested in the flowering period, with both the macro and micronutrients concentrations being evaluated. The other two plants were harvested at the end of the cycle, when the productions of grain and vegetable dry matter (aerial parts, root, grain and total were evaluated. Lithothamnium showed practically the same effect of the commercial dolomite limestone in the correction of the acidity and in the saturation for bases being used the dose to reach a V at 70%. Lithothamnium promoted in the three soils, the elevation of calcium and magnesium levels, increasing the pH values and saturation for bases, and consequently, reduction in the saturation for aluminum, accrediting the product to be used as corrective and fertilizer. Those effects promoted better nutrition conditions, growth and production of the bean plant. The doses to reach 90% of the maximum production of grains in the NQ and LV soils were 610 and 1.090 kg ha-1, respectively, these doses being lower than those required to reach a V at

  12. Primary productivity

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Parulekar, A.H.

    Photosynthetic production in the oceans in relation to light, nutrients and mixing processes is discussed. Primary productivity in the estuarine region is reported to be high in comparison to coastal and oceanic waters. Upwelling phenomenon...

  13. Monte Carlo study of radial energy deposition from primary and secondary particles for narrow and large proton beamlet source models

    International Nuclear Information System (INIS)

    Peeler, Christopher R; Titt, Uwe

    2012-01-01

    In spot-scanning intensity-modulated proton therapy, numerous unmodulated proton beam spots are delivered over a target volume to produce a prescribed dose distribution. To accurately model field size-dependent output factors for beam spots, the energy deposition at positions radial to the central axis of the beam must be characterized. In this study, we determined the difference in the central axis dose for spot-scanned fields that results from secondary particle doses by investigating energy deposition radial to the proton beam central axis resulting from primary protons and secondary particles for mathematical point source and distributed source models. The largest difference in the central axis dose from secondary particles resulting from the use of a mathematical point source and a distributed source model was approximately 0.43%. Thus, we conclude that the central axis dose for a spot-scanned field is effectively independent of the source model used to calculate the secondary particle dose. (paper)

  14. Nutrient uplift in a cyclonic eddy increases diversity, primary productivity and iron demand of microbial communities relative to a western boundary current

    Directory of Open Access Journals (Sweden)

    Martina A. Doblin

    2016-04-01

    Full Text Available The intensification of western boundary currents in the global ocean will potentially influence meso-scale eddy generation, and redistribute microbes and their associated ecological and biogeochemical functions. To understand eddy-induced changes in microbial community composition as well as how they control growth, we targeted the East Australian Current (EAC region to sample microbes in a cyclonic (cold-core eddy (CCE and the adjacent EAC. Phototrophic and diazotrophic microbes were more diverse (2–10 times greater Shannon index in the CCE relative to the EAC, and the cell size distribution in the CCE was dominated (67% by larger micro-plankton $(\\geq 20\\lrm{\\mu }\\mathrm{m}$ ≥ 20 μ m , as opposed to pico- and nano-sized cells in the EAC. Nutrient addition experiments determined that nitrogen was the principal nutrient limiting growth in the EAC, while iron was a secondary limiting nutrient in the CCE. Among the diazotrophic community, heterotrophic NifH gene sequences dominated in the EAC and were attributable to members of the gamma-, beta-, and delta-proteobacteria, while the CCE contained both phototrophic and heterotrophic diazotrophs, including Trichodesmium, UCYN-A and gamma-proteobacteria. Daily sampling of incubation bottles following nutrient amendment captured a cascade of effects at the cellular, population and community level, indicating taxon-specific differences in the speed of response of microbes to nutrient supply. Nitrogen addition to the CCE community increased picoeukaryote chlorophyll a quotas within 24 h, suggesting that nutrient uplift by eddies causes a ‘greening’ effect as well as an increase in phytoplankton biomass. After three days in both the EAC and CCE, diatoms increased in abundance with macronutrient (N, P, Si and iron amendment, whereas haptophytes and phototrophic dinoflagellates declined. Our results indicate that cyclonic eddies increase delivery of nitrogen to the upper ocean to potentially

  15. Primary source of income is associated with differences in HIV risk behaviors in street-recruited samples

    Directory of Open Access Journals (Sweden)

    Fernández-Esquer Maria E

    2004-06-01

    Full Text Available Abstract Background The relationship between primary source of income and HIV risk behaviors and the racial/ethnic differences in risk behavior profiles among disadvantaged populations have not been fully explored. This is unusual given that the phenomenon of higher risk in more disadvantaged populations is well-known but the mechanisms remain unclear. We examined the relationship between primary source of income and differences in HIV risk behaviors among four racial/ethnic groups in the southern United States. Methods Self-reported data on primary source of income and HIV risk behaviors were collected from 1494 African American, Hispanic, Asian, and White men and women in places of public congregation in Houston, Texas. Data were analyzed using calculation of percentages and by chi-square tests with Yates correction for discontinuity where appropriate. Results Data revealed that a higher proportion of whites were involved in sex for money exchanges compared to the other racial groups in this sample. The data suggest that similar street sampling approaches are likely to recruit different proportions of people by primary income source and by ethnicity. It may be that the study locations sampled are likely to preferentially attract those involved in illegal activities, specifically the white population involved in sex for drug or money exchanges. Research evidence has shown that people construct highly evolved sexual marketplaces that are localized and most unlikely to cross racial, ethnic, and socioeconomic or geographical boundaries. Thus, the areas that we sampled may have straddled a white sexual marketplace more than that of the other groups, leading to an over-representation of sex exchange in this group. Drug use was highest among those with illegal primary sources of income (sex exchange and drug dealing and theft, and they were also those most likely to have injected drugs rather than administered them by any other route (p Conclusions

  16. Lithium Carbon Monofluoride: The Next Primary Chemistry for Soldier Portable Power Sources

    National Research Council Canada - National Science Library

    Suszko, Arek

    2006-01-01

    .... Current lithium-ion rechargeable battery technologies have a specific energy of 170 Watthours/ kilogram and state-of-the-art primary lithium-based systems have a specific energy approaching 200 Watt-hours/kilogram...

  17. Isotope-aided studies of nutrient cycling and soil fertility assessment in humid pasture systems

    International Nuclear Information System (INIS)

    Wilkinson, S.R.

    1983-01-01

    Maintenance of primary productivity in grazed ecosystems depends on the orderly cycling of mineral nutrients. Potential applications of nuclear techniques to the study of soil fertility assessment and nutrient cycling are discussed for the plant nutrients N, P, K and S. The bioavailability of extrinsic and intrinsic sources of mineral nutrients are also discussed. With improvements in analytical technology, it appears feasible to use 15 N in grazed pasture ecosystems for N cycling studies. Sulphur cycling in soil/plant/grazing animal systems has been successfully studied, and further opportunities exist using 35 S to study nutrient flows in grazed grassland systems. Opportunities also appear for increased application of tracer technology in the evaluation of mineral intakes and mineral bioavailability to ruminants grazing semi-arid grassland herbage under native soil fertility, with supplemental fertilization, and in the evaluation of mineral supplementation procedures. Root system distribution and function also can be studied advantageously using tracer techniques. (author)

  18. Effects of Nutrient Dynamics, Light and Temperature on the Patchiness of Phytoplankton and Primary Production in the Estuarine and Coastal Zones of Liaodong Bay, China: A Typical Case Study

    Science.gov (United States)

    Pei, S.; Laws, E. A.; Ye, S.

    2017-12-01

    Fluvial inputs of nutrients and efficient nutrient recycling mechanisms make estuarine and coastal zones highly productive bodies of water. For the same reasons, they are susceptible to eutrophication problems. In China, eutrophication problems along coasts are becoming serious because of discharges of domestic sewage and industrial wastewater and runoff of agricultural fertilizer. Addressing these problems requires an informed assessment of the factors that controlling algal production. Our study aims at determining the factors that controlling patchiness of phytoplankton and primary production in Liaodong Bay, China that receives large inputs of nutrients from human activities in its watershed, and examining the variation patterns of phytoplankton photosynthesis under both stressors of climate change and human activities. Results of our field study suggest that nutrient concentrations were above growth-rate-saturating concentrations throughout Liaodong bay, with the possible exception of phosphate at some stations. This assessment was consistent with the results of nutrient enrichment experiments and the values of light-saturated photosynthetic rates and areal photosynthetic rates. Two large patches of high biomass and production with dimensions on the order of 10 km reflect the effects of water temperature and variation of light penetration restricted by water turbidity. To examine the effects of irradiance and temperature on light-saturated photosynthetic rates normalized to chlorophyll a concentrations (Popt), light-conditioned Popt values were modeled as a function of the temperature with a satisfactory fit to our field data (R2 = 0.60, p = 0.003). In this model, light-conditioned Popt values increased with temperatures from 22°C to roughly 25°C but declined precipitously at higher temperatures. The relatively high Popt values and low ratios of light absorbed to photosynthesis at coastal stations suggest the highly efficient usage of absorbed light by

  19. The subtropical nutrient spiral

    Science.gov (United States)

    Jenkins, William J.; Doney, Scott C.

    2003-12-01

    We present an extended series of observations and more comprehensive analysis of a tracer-based measure of new production in the Sargasso Sea near Bermuda using the 3He flux gauge technique. The estimated annually averaged nitrate flux of 0.84 ± 0.26 mol m-2 yr-1 constitutes only that nitrate physically transported to the euphotic zone, not nitrogen from biological sources (e.g., nitrogen fixation or zooplankton migration). We show that the flux estimate is quantitatively consistent with other observations, including decade timescale evolution of the 3H + 3He inventory in the main thermocline and export production estimates. However, we argue that the flux cannot be supplied in the long term by local diapycnal or isopycnal processes. These considerations lead us to propose a three-dimensional pathway whereby nutrients remineralized within the main thermocline are returned to the seasonally accessible layers within the subtropical gyre. We describe this mechanism, which we call "the nutrient spiral," as a sequence of steps where (1) nutrient-rich thermocline waters are entrained into the Gulf Stream, (2) enhanced diapycnal mixing moves nutrients upward onto lighter densities, (3) detrainment and enhanced isopycnal mixing injects these waters into the seasonally accessible layer of the gyre recirculation region, and (4) the nutrients become available to biota via eddy heaving and wintertime convection. The spiral is closed when nutrients are utilized, exported, and then remineralized within the thermocline. We present evidence regarding the characteristics of the spiral and discuss some implications of its operation within the biogeochemical cycle of the subtropical ocean.

  20. Microbial enzyme activity, nutrient uptake and nutrient limitation in forested streams

    Science.gov (United States)

    Brian H. Hill; Frank H. McCormick; Bret C. Harvey; Sherri L. Johnson; Melvin L. Warren; Colleen M. Elonen

    2010-01-01

    The flow of organic matter and nutrients from catchments into the streams draining them and the biogeochemical transformations of organic matter and nutrients along flow paths are fundamental processes instreams (Hynes,1975; Fisher, Sponseller & Heffernan, 2004). Microbial biofilms are often the primary interface for organic matter and nutrient uptake and...

  1. Choice of primary health care source in an urbanized low-income community in Singapore: a mixed-methods study.

    Science.gov (United States)

    Wee, Liang En; Lim, Li Yan; Shen, Tong; Lee, Elis Yuexian; Chia, Yet Hong; Tan, Andrew Yen Siong; Koh, Gerald Choon-Huat

    2014-02-01

    Cost and misperceptions may discourage lower income Singaporeans from utilizing primary care. We investigated sources of primary care in a low-income Singaporean community in a mixed-methods study. Residents of a low-income public rental flat neighbourhood were asked for sociodemographic details and preferred source of primary care relative to their higher income neighbours. In the qualitative component, interviewers elicited, from patients and health care providers, barriers/enablers to seeking care from Western-trained doctors. Interviewees were selected via purposive sampling. Transcripts were analyzed thematically, and iterative analysis was carried out using established qualitative method. Participation was 89.8% (359/400). Only 11.1% (40/359) preferred to approach Western-trained doctors, 29.5% (106/359) preferred alternative medicine, 6.7% (24/359) approached family/friends and 52.6% (189/359) preferred self-reliance. Comparing against higher income neighbours, rental flat residents were more likely to turn to alternative medicine and family members but less likely to turn to Western-trained doctors (P Self-reliance was perceived as acceptable for 'small' illnesses but not for 'big' ones, communal spirit was cited as a reason for consulting family/friends and social distance from primary care practitioners was highlighted as a reason for not consulting Western-trained doctors. Western-trained physicians are not the first choice of lower income Singaporeans for seeking primary care. Knowledge, primary care characteristics and costs were identified as potential barriers/enablers.

  2. A comparison of UK primary care data with other national data sources for monitoring the prevalence of smoking during pregnancy.

    Science.gov (United States)

    Dhalwani, Nafeesa N; Tata, Laila J; Coleman, Tim; Fiaschi, Linda; Szatkowski, Lisa

    2015-09-01

    We aimed to assess the potential usefulness of primary care data in the UK for estimating smoking prevalence in pregnancy by comparing the primary care data estimates with those obtained from other data sources. In The Health Improvement Network (THIN) primary care database, we identified pregnant smokers using smoking information recorded during pregnancy. Where this information was missing, we used smoking information recorded prior to pregnancy. We compared annual smoking prevalence from 2000 to 2012 in THIN with measures from the Infant Feeding Survey (IFS), Smoking At Time of Delivery (SATOD), Child Health Systems Programme (CHSP) and Scottish Morbidity Record (SMR). Smoking estimates from THIN data converged with estimates from other sources after 2004, though still do not agree completely. For example, in 2012 smoking prevalence at booking was 11.6% in THIN using data recorded only during pregnancy, compared with 19.6% in SMR data. However, the use of smoking data recorded up to 27 months before conception increased the THIN prevalence to 20.3%, improving the comparability. Under-recording of smoking status during pregnancy results in unreliable prevalence estimates from primary care data and needs improvement. However, in the absence of gestational smoking data, the inclusion of pre-conception smoking records may increase the utility of primary care data. One strategy to improve gestational smoking status recording in primary care could be the inclusion of pregnancy in the Quality and Outcome's Framework as a condition for which smoking status and smoking cessation advice must be recorded electronically in patient records. © The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health.

  3. Influence of organic and inorganic sources of nutrients on the functional diversity of microbial communities in the vegetable cropping system of the Indo-Gangetic plains.

    Science.gov (United States)

    Manjunath, Mallappa; Kumar, Upendra; Yadava, Raj Bahadur; Rai, Awadhesh Bahadur; Singh, Bijendra

    2018-05-31

    The aim of the present study was to assess the effects of different organic and inorganic fertilizers on the functional diversity of soil microbial community under a vegetable production system. The Biolog ® Eco-plate technique and indices, such as average well-colour development (AWCD), McIntosh and Shannon diversity were employed to study the diversity of soil microorganisms. The AWCD, i.e. overall utilization of carbon sources, suggested that different organic treatments had a significant impact on the metabolic activity of soil microorganisms. After 120h, the highest AWCD values were observed in poultry manure (2.5 t·ha -1 )+vermicompost (3.5 t·ha -1 ) (0.63) and farm yard manure (FYM) (10 t·ha -1 )+vermicompost (3.5 t·ha -1 ) (0.61). After 72h, the highest value of the McIntosh diversity index was recorded in poultry manure (2.5 t·ha -1 )+vermicompost (3.5 t·ha -1 ) (3.87), followed by poultry manure (2.5 t·ha -1 )+vermicompost (3.5 t·ha -1 )+biofertilizers (Azotobacter 500 g·ha -1 applied as seed treatment) (3.12). In the case of the Shannon diversity index, the highest values were noticed in organic treatments; however, there was no significant differences between organic and inorganic treatments. Biplot analysis showed a clear differentiation of organic treatments from the inorganic control. The amino acids, phenolics and polymer utilizing microorganisms were dominant in organic treatments. Inorganic control recorded the lowest values of the microbial diversity indices. Through this study, we have identified the best combination of organic nutrients, i.e. poultry manure (2.5 t·ha -1 )+vermicompost (3.5 t·ha -1 ) for the stimulation of metabolically active soil microbial communities. Copyright © 2018 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

  4. Effect of supplemental nutrient source on heifer growth and reproductive performance, and on utilization of corn silage-based diets by beef steers.

    Science.gov (United States)

    Howlett, C M; Vanzant, E S; Anderson, L H; Burris, W R; Fieser, B G; Bapst, R F

    2003-09-01

    Two experiments were conducted to determine effects of oilseeds or soybean hulls on growth and reproductive performance of heifers and utilization of corn silage diets by growing beef cattle. In Exp. 1, 96 beef heifers (249 kg of BW) were used in a randomized complete block design. Treatments were as follows: 1) corn and soybean meal (CON) at 56% of the DMI; 2) whole linted cottonseed at 15% of the DMI (COT); 3) whole raw soybeans at 15% of the DMI (SB); or 4) pelleted soyhulls at 30% of the DMI (SH). Diets were formulated to be isonitrogenous (13.8% CP) and fed to achieve target weights equal to 65% of expected mature BW at the time of AI. Estrus was synchronized and heifers were inseminated by AI in response to detected estrus. Because the energy value for SH was underestimated, cumulative ADG for SH (1.03 kg/d) was greater (P 0.10) the proportion of pubertal heifers at the beginning of the breeding season: CON (60%), COT (53%), SB (69%), SH (71%), or first-service conception rates: CON (37%); COT (38%); SB (57%); SH (42%). In Exp. 2, crossbred steers (387 kg) were used in a 6 x 6 Latin square design to evaluate the effects of supplemental nutrient source on utilization of corn silage diets. Treatments included diets used in Exp. 1, plus a negative control (soybean meal at 10% of the DMI; SIL) and whole raw soybeans at 25% of the DMI (SB25). Diets were formulated to be isonitrogenous (13.8% CP) except SB25 (17% CP), and were fed twice daily at 1.8 x NEm. Oilseed inclusion decreased (P tract NDF digestibilities. The CON and SH diets had the greatest (P tract OM digestibilities. Microbial efficiencies were greatest (P reproductive performance of heifers. Although oilseed additions increased total fatty acid flow to the duodenum, a high degree of biohydrogenation occurred, greatly increasing C18:0, with only marginal increases in unsaturated fatty acid flow. Depending on diet and feeding conditions, inclusion of whole oilseeds may not be an effective means of

  5. Effect of sources of calcium salts of fatty acids on production, nutrient digestibility, energy balance, and carryover effects of early lactation grazing dairy cows.

    Science.gov (United States)

    de Souza, Jonas; Batistel, Fernanda; Santos, Flávio Augusto Portela

    2017-02-01

    The objective of our study was to investigate the effects of sources of calcium salts of fatty acids (FA) on production, nutrient digestibility, energy balance, and carryover effects of early lactation grazing dairy cows. Treatment diets were offered from 3 to 16 wk postpartum (the treatment period), in which all cows grazed elephantgrass (Pennisetum purpureum 'Cameroon') and treatments were added to a concentrate supplement. The treatments were (1) control (concentrate without supplemental fat); (2) concentrate with calcium salts of soybean FA (CSSO); and (3) concentrate with calcium salts of palm FA (CSPO). From 17 to 42 wk postpartum (the carryover period), all cows received a common diet fed as a total mixed ration. During the treatment period, CSPO increased milk yield, milk fat yield, 3.5% fat-corrected milk, energy-corrected milk, and cumulative milk yield compared with control and CSSO. Treatment CSSO increased the yield of milk but did not affect 3.5% fat-corrected milk or energy-corrected compared with control. Also, CSSO decreased milk fat yield, dry matter intake, neutral detergent fiber digestibility, and body weight and body condition loss. Compared with control, both CSSO and CSPO increased feed efficiency (3.5% fat-corrected milk:dry matter intake), and CSPO increased feed efficiency compared with CSSO. When considering energy partitioning (as % energy intake), CSPO increased energy partitioning toward milk and increased energy mobilized from body reserves compared with control and CSSO. Furthermore, CSSO tended to reduce the mobilization of energy from body reserves compared with control. In the carryover period, no differences in milk composition were observed among treatments. A treatment by time interaction was observed during the carryover period for milk yield because cows on CSPO maintained higher production compared with control and CSSO cows until 30 wk postpartum; CSSO had a lower carryover effect sustaining higher milk yield compared with

  6. Sources of variation in primary care clinical workflow: implications for the design of cognitive support.

    Science.gov (United States)

    Militello, Laura G; Arbuckle, Nicole B; Saleem, Jason J; Patterson, Emily; Flanagan, Mindy; Haggstrom, David; Doebbeling, Bradley N

    2014-03-01

    This article identifies sources of variation in clinical workflow and implications for the design and implementation of electronic clinical decision support. Sources of variation in workflow were identified via rapid ethnographic observation, focus groups, and interviews across a total of eight medical centers in both the Veterans Health Administration and academic medical centers nationally regarded as leaders in developing and using clinical decision support. Data were reviewed for types of variability within the social and technical subsystems and the external environment as described in the sociotechnical systems theory. Two researchers independently identified examples of variation and their sources, and then met with each other to discuss them until consensus was reached. Sources of variation were categorized as environmental (clinic staffing and clinic pace), social (perception of health information technology and real-time use with patients), or technical (computer access and information access). Examples of sources of variation within each of the categories are described and discussed in terms of impact on clinical workflow. As technologies are implemented, barriers to use become visible over time as users struggle to adapt workflow and work practices to accommodate new technologies. Each source of variability identified has implications for the effective design and implementation of useful health information technology. Accommodating moderate variability in workflow is anticipated to avoid brittle and inflexible workflow designs, while also avoiding unnecessary complexity for implementers and users.

  7. Design considerations for primary neutron beam collimation on the Spallation Neutron Source

    International Nuclear Information System (INIS)

    Howells, W.S.

    1980-09-01

    A scheme for the design of primary neutron beam collimation is presented which is based on ray diagrams. The practical application of the ideas is outlined and the influence of various constraints such as beam shutters is discussed. The ideas are illustrated with examples which include the layouts for some typical instruments. (author)

  8. The Day-to-Day Work of Primary School Teachers: A Source of Professional Learning

    Science.gov (United States)

    Ambler, Trudy Belinda

    2016-01-01

    Teachers are an important influence on students' learning, and therefore the opportunity for teachers to learn and develop is something of interest to educators internationally. This article reports on a research project involving six primary school teachers who participated in one-on-one and small group interviews to explore the opportunities for…

  9. Where Western Australian Graduate Diploma of Education Primary Students Source Their Information on Sustainability

    Science.gov (United States)

    Lummis, Geoff W.; Morris, Julia E.; Lock, Graeme; Odgaard, Judith

    2015-01-01

    Sustainability has recently been made a cross-curriculum priority in Australia, through the development and implementation of the Australian Curriculum. Subsequently, primary and secondary teachers across all subject areas are required to integrate Education for Sustainability (EfS) into formal education. A recent research case study was…

  10. Sources of Cost Expansion: Primary Education in Norway 1946-90.

    Science.gov (United States)

    Falch, Torberg; Rattso, Jorn

    1996-01-01

    Shows that primary education spending growth in Norway resulted from cost factors determined at the national level, together with lack of adjustment to rising costs in local governments. Policies to control school spending must address the central government's bargaining strength to hold back on teacher wages and employment and local governments'…

  11. A simple alkali-metal and noble gas ion source for SIMS equipments with mass separation of the primary ions

    International Nuclear Information System (INIS)

    Duesterhoeft, H.; Pippig, R.

    1986-01-01

    An alkali-metal ion source working without a store of alkali-metals is described. The alkali-metal ions are produced by evaporation of alkali salts and ionization in a low-voltage arc discharge stabilized with a noble gas plasma or in the case of small alkali-metal ion currents on the base of the well known thermic ionization at a hot tungsten wire. The source is very simple in construction and produces a stable ion current of 0.3 μA for more than 100 h. It is possible to change the ion species in a short time. This source is applicable to all SIMS equipments using mass separation for primary ions. (author)

  12. Shifting primary energy source and NOx emission location with plug-in hybrid vehicles

    Science.gov (United States)

    Karman, Deniz

    2011-06-01

    Plug-in hybrid vehicles (PHEVs) present an interesting technological opportunity for using non-fossil primary energy in light duty passenger vehicles, with the associated potential for reducing air pollutant and greenhouse gas emissions, to the extent that the electric power grid is fed by non-fossil sources. This perspective, accompanying the article by Thompson et al (2011) in this issue, will touch on two other studies that are directly related: the Argonne study (Elgowainy et al 2010) and a PhD thesis from Utrecht (van Vliet 2010). Thompson et al (2011) have examined air quality effects in a case where the grid is predominantly fossil fed. They estimate a reduction of 7.42 tons/day of NOx from motor vehicles as a result of substituting electric VMTs for 20% of the light duty gasoline vehicle miles traveled. To estimate the impact of this reduction on air quality they also consider the increases in NOx emissions due to the increased load on electricity generating units. The NOx emission increases are estimated as 4.0, 5.5 and 6.3 tons for the Convenience, Battery and Night charging scenarios respectively. The net reductions are thus in the 1.1-3.4 tons/day range. The air quality modelling results presented show that the air quality impact from a ground-level ozone perspective is favorable overall, and while the effect is stronger in some localities, the difference between the three scenarios is small. This is quite significant and suggests that localization of the NOx emissions to point sources has a more pronounced effect than the absolute reductions achieved. Furthermore it demonstrates that localization of NOx emissions to electricity generating units by using PHEVs in vehicle traffic has beneficial effects for air quality not only by minimizing direct human exposure to motor vehicle emissions, but also due to reduced exposure to secondary pollutants (i.e. ozone). In an electric power grid with a smaller share of fossil fired generating units, the beneficial

  13. Aggregate stability as affected by short and long-term tillage systems and nutrient sources of a hapludox in southern Brazil Efeitos de curto e de longo prazo da aplicação de sistemas de manejo do solo e de fontes de nutrientes sobre a estabilidade de agregados, em um nitossolo vermelho

    Directory of Open Access Journals (Sweden)

    Milton da Veiga

    2009-08-01

    Full Text Available The ability of a soil to keep its structure under the erosive action of water is usually high in natural conditions and decreases under frequent and intensive cultivation. The effect of five tillage systems (NT = no-till; CP = chisel plowing and one secondary disking; CT = primary and two secondary distings; CTb = CT with crop residue burning; and CTr = CT with removal of crop residues from the field, combined with five nutrient sources (C = control, no nutrient application; MF = mineral fertilizers according to technical recommendations for each crop; PL = 5 Mg ha-1 y-1 fresh matter of poultry litter; CM = 60 m³ ha-1 y-1 slurry cattle manure; and SM = 40 m³ ha-1 y-1 slurry swine manure on wet-aggregate stability was determined after nine years (four sampled soil layers and on five sampling dates in the 10th year (two sampled soil layers of the experiment. The size distribution of the air-dried aggregates was strongly affected by soil bulk density, and greater values of geometric mean diameter (GMD AD found in some soil tillage or layer may be partly due to the higher compaction degree. After nine years, the GMD AD on the surface was greater in NT and CP compared to conventional tillage systems (CT, CTb and CTr, due to the higher organic matter content, as well as less soil mobilization. Aggregate stability in water, on the other hand, was affected by the low variation in previous gravimetric moisture of aggregates, which contributed to a high coefficient of variation of this attribute. The geometric mean diameter of water-stable aggregates (GMD WS was highest in the 0.00-0.05 m layer in the NT system, in the layers 0.05-0.10 and 0.12-0.17 m in the CT, and values were intermediate in CP. The stability index (SI in the surface layers was greater in treatments where crop residues were kept in the field (NT, CP and CT, which is associated with soil organic matter content. No differences were found in the layer 0.27-0.32 m. The effect of nutrient

  14. Comparative studies on the effect of gamma irradiation on decontamination and nutrient quality of smoked dry shrimp from different water sources in Ghana

    International Nuclear Information System (INIS)

    Akuamoa, F.

    2012-01-01

    Dry and smoked shrimp constitute important nutrient supplement for the populace in Ghana. Shrimp continues to represent one of the safest forms of muscle protein consumed in the world. However, the attending microbial load from the environment during drying requires concerted efforts to curtail contaminating microbes (fungi, bacteria) and other biodeterio agents (such as insects). In this study, microbiological quality (with particular reference to fungi) was studied before and after gamma irradiation (0, 4, 8 and 10 kGy), with the view of identifying potential mycotoxine-producing fungal species resident in shrimp taken from three different water sources (lagoon, sea, river) which may endanger the health of consumers. Consumer acceptance (preference) tests were performed using conventional sensory evaluation parameters (colour, taste, texture, aroma) on the samples. A structured questionnaire was employed to ascertain biodata, educational background, storage and packaging practices of the traders. The storage stability of the shrimp was determined by sorption isotherms using glycerol: water mixtures to stimulate Environmental Relative Humidity (20, 55, 65, 75, 85 and 95% Eh) for 20 days. Population of fungi was ascertained on two media (Ogee, D RBC) using the conventional decimal serial dilution technique up to 1:10 4 ; Total Aerobic Bacteria was determined on Pca at 32 degrees Celsius for 48 hours. Insects in the samples were determined by the Hidden Identification technique; Crude protein was estimated by the Kjeldhal method and total ash was determined using the Carbolite furnace. Percentage fat and moisture contents were determined concurrently using the Miniature Bench Top Nuclear Magnetic Resonance (BTNMR); Elemental composition was estimated by Atomic Absorption Spectrometry (AAS). The Flame Photometer was used in the determination of sodium and potassium contents of samples. Minolta Chroma Meter was used to measure the colour L*a*b value scale. Twenty

  15. Variability of nutrients and carbon dioxide in the Antarctic Intermediate Water between 1990 and 2014

    Science.gov (United States)

    Panassa, Essowè; Santana-Casiano, J. Magdalena; González-Dávila, Melchor; Hoppema, Mario; van Heuven, Steven M. A. C.; Völker, Christoph; Wolf-Gladrow, Dieter; Hauck, Judith

    2018-03-01

    Antarctic Intermediate Water (AAIW) formation constitutes an important mechanism for the export of macronutrients out of the Southern Ocean that fuels primary production in low latitudes. We used quality-controlled gridded data from five hydrographic cruises between 1990 and 2014 to examine decadal variability in nutrients and dissolved inorganic carbon (DIC) in the AAIW (neutral density range 27 net primary productivity (more nutrients unutilized) in the source waters of the AAIW could have contributed as well but cannot fully explain all observed changes.

  16. Nuclear energy ranks first as primary energy source in Europe in 2012

    International Nuclear Information System (INIS)

    Anon.

    2014-01-01

    According to the 2012 report of Eurostat, nuclear energy represents 30% of the production of primary energy in the member states of the E.U., renewable energies a little less than 20% and fossil energies a little more than 50%. In Europe the production of primary energy has been decreasing since 2001, from 940 million tonnes in 2001 to 794 million tonnes in 2012. In Europe the gross energy consumption has decreased in 24 member states to reach the level of 1995 year. In 2012 the E.U.'s dependence rate for energy was of 53% on average. Only Denmark was a net exporter of energy while the dependence rate for energy of the main E.U. energy consumers were: Germany (61%), Spain (73%), France (48%), United-Kingdom (42%) and Italy (81%). (A.C.)

  17. Teaching with Primary Sources: Professional Development from the Library of Congress at Your Fingertips

    Science.gov (United States)

    Ridgway, Elizabeth

    2009-01-01

    In the information-rich, rapidly changing 21st-century, educators are faced with unprecedented challenges. While new technologies have brought the people of the planet closer together, they have also brought them into contact with an overwhelming array of information sources. The Library of Congress is positioned to help educators respond to these…

  18. Characterizing Aggregated Exposure to Primary Particulate Matter: Recommended Intake Fractions for Indoor and Outdoor Sources

    DEFF Research Database (Denmark)

    Fantke, Peter; Jolliet, Olivier; Apte, Joshua Schulz

    2017-01-01

    Exposure to fine particulate matter (PM_(2.5)) from indoor and outdoor sources is a leading environmental contributor to global disease burden. In response, we established under the auspices of the UNEP/SETAC Life Cycle Initiative a coupled indoor-outdoor emission-to-exposure framework to provide...

  19. Laboratory study of the PCB transport from primary sources to building materials

    Science.gov (United States)

    The sorption of airborne polychlorinated biphenyls (PCBs) by twenty building materials and their subsequent re-emission (desorption) from concrete were investigated using two 53-L environmental chambers connected in series with a field-collected caulk in the source chamber servin...

  20. Characterization of the Kootenai River Algae Community and Primary Productivity Before and After Experimental Nutrient Addition, 2004–2007 [Chapter 2, Kootenai River Algal Community Characterization, 2009 KTOI REPORT].

    Energy Technology Data Exchange (ETDEWEB)

    Holderman, Charlie [Kootenai Tribe of Idaho; Bonners Ferry, ID; Anders, Paul [Cramer Fish Sciences; Moscow, ID; Shafii, Bahman [Statistical Consulting Services; Clarkston, WA

    2009-07-01

    The Kootenai River ecosystem (spelled Kootenay in Canada) has experienced numerous ecological changes since the early 1900s. Some of the largest impacts to habitat, biological communities, and ecological function resulted from levee construction along the 120 km of river upstream from Kootenay Lake, completed by the 1950s, and the construction and operation of Libby Dam on the river near Libby Montana, completed in 1972. Levee construction isolated tens of thousands of hectares of historic functioning floodplain habitat from the river channel downstream in Idaho and British Columbia (B.C.) severely reducing natural biological productivity and habitat diversity crucial to large river-floodplain ecosystem function. Libby Dam greatly reduces sediment and nutrient transport to downstream river reaches, and dam operations cause large changes in the timing, duration, and magnitude of river flows. These and other changes have contributed to the ecological collapse of the post-development Kootenai River ecosystem and its native biological communities. In response to large scale loss of nutrients, experimental nutrient addition was initiated in the North Arm of Kootenay Lake in 1992, in the South Arm of Kootenay Lake in 2004, and in the Kootenai River at the Idaho-Montana border during 2005. This report characterizes baseline chlorophyll concentration and accrual (primary productivity) rates and diatom and algal community composition and ecological metrics in the Kootenai River for four years, one (2004) before, and three (2005 through 2007) after nutrient addition. The study area encompassed a 325 km river reach from the upper Kootenay River at Wardner, B.C. (river kilometer (rkm) 445) downstream through Montana and Idaho to Kootenay Lake in B.C. (rkm 120). Sampling reaches included an unimpounded reach furthest upstream and four reaches downstream from Libby Dam affected by impoundment: two in the canyon reach (one with and one without nutrient addition), a braided reach

  1. Reception of nutrition information by adult and older adult users of Primary Healthcare: Occurrence, associated factors, and sources of information

    Directory of Open Access Journals (Sweden)

    Ivana Loraine LINDEMANN

    Full Text Available ABSTRACT Objective: To investigate reception of nutrition information (outcome, associated factors, and types of sources. Methods: This cross-sectional study, conducted in 2013, included 1,246 adult and older adult users of the Primary Healthcare network of Pelotas, Rio Grande do Sul, Brazil. The sample was characterized by reception of nutrition information, its sources, and demographic, socioeconomic, health, knowledge, and life habit variables. Prevalence ratios and their respective 95% confidence intervals investigated associations between reception of nutrition information and independent variables. Results: More than one-third of the sample (37.6% received nutrition information (95%CI=34.9-40.3. Older adults, individuals with positive self-perceived diet, those who received health information, and those who were physically active were more likely to receive nutrition information, and normal weight individuals were less likely. The outcome differed by income strata, being highest in the highest quintile. There was a linear trend for education level and for following the Ten Steps to Healthy Eating: the outcome was more likely in individuals with at least higher education and those who followed at least four steps. The most cited sources of nutrition information were television shows (56.2%, other (46.2%, physician (41.2%, Internet (25.1%, and family members (20.9%, which did not differ by sex. Conclusion: Primary healthcare users received little nutrition information, and television could be a useful tool for the institutions responsible for the sector to disseminate the official nutritional recommendations.

  2. Ozone impact on vegetation: A primary lesion in sugar export from source leaves

    Energy Technology Data Exchange (ETDEWEB)

    Grantz, D.A.

    1999-07-01

    Ozone (O{sub 3}) remains a serious threat to native and agricultural vegetation. In many plants, including Pima cotton (Gossypium barbadense L.), O{sub 3} reduces development of efficient root systems. To investigate the mechanism of O{sub 3}-inhibited allocation of biomass to roots, leaves were exposed to 45 min pulses of O{sub 3} ranging from 0.0 to 0.8 {micro}l 1{sup 11} followed by a 15 min pulse of {sup 14}CO{sub 2}. The rapid phase of export of {sup 14}C-carbohydrate from source leaves was monitored with a Geiger Muller Tube. A single compartment model with a single exponential decay function yielded first order rate constants. O{sub 3} retarded efflux, decreased the rate constant, and increased the calculated soluble sugar pool remaining in the source leaves. With incorporation of an asymptote into the single exponential model, equivalent to the label remaining in the leaf at the end of a prolonged photoperiod, calculated rate constants and sugar contents for O{sub 3}-free control leaves were similar to values from the literature. Total carbohydrate transported from source leaves and thus available for export to the roots was reduced by O{sub 3} effects on assimilation (up to 20%) and O{sub 3} effects on efflux (up to 70%). O{sub 3}-inhibition of root system development is therefore dominated by the impact on phloem translocation rather than by effects on carbon assimilation.

  3. New primary energy source by thorium molten-salt reactor technology

    International Nuclear Information System (INIS)

    Furukawa, Kazuo; Kato, Yoshio; Furuhashi, Akira; Numata, Hiroo; Mitachi, Koushi; Yoshioka, Ritsuo; Sato, Yuzuru; Arakawa, Kazuto

    2005-01-01

    Among the next 30 years, we have to implement a practical measure in the global energy/environmental problems, solving the followings: (1) replacing the fossil fuels without CO 2 emission, (2) no severe accidents, (3) no concern on military, (4) minimizing wastes, (5) economical, (6) few R and D investment and (7) rapid/huge global application supplying about half of the total primary energy till 50 years later. For this purpose the following system was proposed: THORIMS-NES [Thorium Molten-Salt Nuclear Energy Synergetic System], which is composed of (A) simple fission Molten-Salt power stations (FUJI), and (B) fissile-producing Accelerator Molten-Salt Breeder (AMSB). It has been internationally prepared a practical Developmental Program for its huge-size industrialization of Th breeding fuel cycle to produce a new rational primary energy. Here it is explained the social meaning, the conceptual system design and technological bases, especially, including the molten fluoride salt technology, which was developed as the triple-functional medium for nuclear-engineering, heat-transfer and chemical engineering. The complex function of this system is fully achieved by the simplified facility using a single phase molten-salt only. (author)

  4. Treated Olive Cake as a Non-forage Fiber Source for Growing Awassi Lambs: Effects on Nutrient Intake, Rumen and Urine pH, Performance, and Carcass Yield

    Directory of Open Access Journals (Sweden)

    M. S. Awawdeh

    2013-05-01

    Full Text Available The objective of this study was to investigate the effects of partial replacement of wheat hay with sun-dried (SOC or acid-treated SOC (ASOC olive cake on nutrient intake and performance of Awassi lambs. An additional objective was to study the effects of acid treatment of olive cake (OC on its chemical composition and nutritive value. On DM basis, sun-drying of OC did not dramatically affect its chemical composition. On the other hand, treating SOC with phosphoric acid decreased (p<0.05 SOC contents of neutral detergent fiber. Twenty seven male lambs (17.6±0.75 kg body weight individually housed in shaded pens were randomly assigned to one of three dietary treatments (9 lambs/treatment. Dietary treatments were formulated to be isocaloric and isonitrogenous by replacing 50% of wheat hay in the control diet (CTL with SOC or ASOC and to meet all nutrient requirements. Dietary treatments had no effects on nutrient intake or digestibility except for ether extract. Lambs fed the SOC diet had (p = 0.05 faster growth rate, greater final body weight, and greater total body weight gain in comparison with the CTL diet, but not different from the ASOC diet. Additionally, lambs fed the SOC diet had greater (p = 0.03 hot and cold carcass weights than the ASOC diet, but not different from the CTL diet. However, feed conversion ratios and dressing percentages were similar among dietary treatments. In conclusion, replacing half of dietary wheat hay with SOC improved performance of Awassi lambs with no detrimental effects on nutrients intake or digestibility. No further improvements in the nutritive value of SOC and lambs performance were detected when SOC was treated with acid.

  5. Effects of nitrogen source and application time on macro and micro nutrients absorption and on development of one in vitro cultivated epiphyte bromeliad

    International Nuclear Information System (INIS)

    Grossi, Fernando; Muraoka, Takashi; Trivelin, Paulo C. O.; Natal Gon lves, Antonio

    1999-01-01

    Aechemea nudiculis seedlings were obtained from seeds collected from mother plants at the Atlantic Tropical Rain Forest in the Iguape county at S Paulo State in Brazil. The seeds were surface sterilised and stored in cold chamber (6 0 C) for six months previously to the trial establishment. The trials were kept in growth chamber under mean temperature of 25 o C and photo period of 16/8 (light/dark) and 3000 lux. The NH4NO3 salt was marked with 15 N at the NH4 + and at the NO3 - separately. They were monthly added to determine application period effect and only one dose was supplied at the medium preparation to find the ionic form absorbed after six months off culture. Two NH4NO3 rates (2:1 e 1:2) were used to determine the effects on plant growth and nutrient absorption. The 1:1 rate was also used to determine the effects on the nutrients absorption. The basic culture medium used was MS 62 with strength for the macro nutrients and full strength for the micro nutrients plus 25 g/L of sucrose; and no vitamins or growth regulators or aminoacids were added to the culture medium. The results showed that the NH4 + was more absorbed than NO3 - and the higher nitrogen absorption occurred in the third month of application. The higher NH4 + concentration favoured N and S absorption and decreased K, Ca, Cu, Fe and Mn absorption; the 1:1 rate favoured the absorption of P, Fe, Mn and Zn. However, the seedling showed betters height and root growth at 1:2 rate. Support: FAPESP and CNPq

  6. Major food sources of calories, added sugars, and saturated fat and their contribution to essential nutrient intakes in the U.S. diet: data from the national health and nutrition examination survey (2003–2006)

    Science.gov (United States)

    2013-01-01

    Background The risk of chronic disease cannot be predicted simply by the content of a single nutrient in a food or food group in the diet. The contribution of food sources of calories, added sugars and saturated fat (SFA) to intakes of dietary fiber and micronutrients of public health importance is also relevant to understanding the overall dietary impact of these foods. Objective Identify the top food sources of calories, added sugars and SFA in the U.S. diet and quantify their contribution to fiber and micronutrient intakes. Methods Single 24-hour dietary recalls (Day 1) collected from participants ≥2 years (n = 16,822) of the What We Eat in America, National Health and Nutrition Examination Survey (WWEIA/NHANES 2003–2006) were analyzed. All analyses included sample weights to account for the survey design. Calorie and nutrient intakes from foods included contributions from disaggregated food mixtures and tabulated by rank order. Results No one food category contributes more than 7.2% of calories to the overall U.S. diet, but half of the top 10 contribute 10% or more of total dietary fiber and micronutrients. Three of the top 10 sources of calories and SFA (beef, milk and cheese) contribute 46.3% of the calcium, 49.5% of the vitamin D, 42.3% of the vitamin B12 as well as other essential nutrients to the American diet. On the other hand, foods categorized as desserts, snacks, or beverages, contribute 13.6% of total calories, 83% of added sugar intake, and provide little or no nutritional value. Including food components of disaggregated recipes more accurately estimated the contribution of foods like beef, milk or cheese to overall nutrient intake compared to “as consumed” food categorizations. Conclusions Some food sources of calories, added sugars and SFA make major contributions to American dietary fiber and micronutrient intakes. Dietary modifications targeting reductions in calories, added sugar, or SFA need to take these key micronutrient

  7. Major food sources of calories, added sugars, and saturated fat and their contribution to essential nutrient intakes in the U.S. diet: data from the National Health and Nutrition Examination Survey (2003-2006).

    Science.gov (United States)

    Huth, Peter J; Fulgoni, Victor L; Keast, Debra R; Park, Keigan; Auestad, Nancy

    2013-08-08

    The risk of chronic disease cannot be predicted simply by the content of a single nutrient in a food or food group in the diet. The contribution of food sources of calories, added sugars and saturated fat (SFA) to intakes of dietary fiber and micronutrients of public health importance is also relevant to understanding the overall dietary impact of these foods. Identify the top food sources of calories, added sugars and SFA in the U.S. diet and quantify their contribution to fiber and micronutrient intakes. Single 24-hour dietary recalls (Day 1) collected from participants ≥2 years (n = 16,822) of the What We Eat in America, National Health and Nutrition Examination Survey (WWEIA/NHANES 2003-2006) were analyzed. All analyses included sample weights to account for the survey design. Calorie and nutrient intakes from foods included contributions from disaggregated food mixtures and tabulated by rank order. No one food category contributes more than 7.2% of calories to the overall U.S. diet, but half of the top 10 contribute 10% or more of total dietary fiber and micronutrients. Three of the top 10 sources of calories and SFA (beef, milk and cheese) contribute 46.3% of the calcium, 49.5% of the vitamin D, 42.3% of the vitamin B12 as well as other essential nutrients to the American diet. On the other hand, foods categorized as desserts, snacks, or beverages, contribute 13.6% of total calories, 83% of added sugar intake, and provide little or no nutritional value. Including food components of disaggregated recipes more accurately estimated the contribution of foods like beef, milk or cheese to overall nutrient intake compared to "as consumed" food categorizations. Some food sources of calories, added sugars and SFA make major contributions to American dietary fiber and micronutrient intakes. Dietary modifications targeting reductions in calories, added sugar, or SFA need to take these key micronutrient sources into account so as not to have the unintended

  8. Primary calibrations of radionuclide solutions and sources for the EML quality assessment program

    Energy Technology Data Exchange (ETDEWEB)

    Fisenne, I.M. [Dept. of Energy, New York, NY (United States)

    1993-12-31

    The quality assurance procedures established for the operation of the U.S. Department of Energy`s Environmental Measurements Laboratory (DOE-EML`s) Quality Assessment Program (QAP) are essentially the same as those that are in effect for any EML program involving radiometric measurements. All these programs have at their core the use of radionuclide standards for their instrument calibration. This paper focuses on EML`s approach to the acquisition, calibration and application of a wide range of radionuclide sources that are required to meet its programmatic needs.

  9. Household Solar Photovoltaics: Supplier of Marginal Abatement, or Primary Source of Low-Emission Power?

    Directory of Open Access Journals (Sweden)

    Graham Palmer

    2013-03-01

    Full Text Available With declining system costs and assuming a short energy payback period, photovoltaics (PV should, at face value, be able to make a meaningful contribution to reducing the emission intensity of Australia’s electricity system. However, solar is an intermittent power source and households remain completely dependent on a “less than green” electricity grid for reliable electricity. Further, much of the energy impact of PV occurs outside of the conventional boundaries of PV life-cycle analyses (LCA. This paper examines these competing observations and explores the broader impacts of a high penetration of household PV using Melbourne, Victoria as a reference. It concludes that in a grid dominated by unsequestered coal and gas, PV provides a legitimate source of emission abatement at high, but declining costs, with the potential for network and peak demand support. It may be technically possible to integrate a high penetration of PV, but the economic and energy cost of accommodating high-penetration PV erodes much of the benefits. Future developments in PV, storage, and integration technologies may allow PV to take on a greater long term role, but in the time horizon usually discussed in climate policy, a large-scale expansion of household PV may hinder rather than assist deep cuts to the emission intensity of Australia’s electricity system.

  10. Global organic carbon emissions from primary sources from 1960 to 2009

    Science.gov (United States)

    Huang, Ye; Shen, Huizhong; Chen, Yilin; Zhong, Qirui; Chen, Han; Wang, Rong; Shen, Guofeng; Liu, Junfeng; Li, Bengang; Tao, Shu

    2015-12-01

    In an attempt to reduce uncertainty, global organic carbon (OC) emissions from a total of 70 sources were compiled at 0.1° × 0.1° resolution for 2007 (PKU-OC-2007) and country scale from 1960 to 2009. The compilation took advantage of a new fuel-consumption data product (PKU-Fuel-2007) and a series of newly published emission factors (EFOC) in developing countries. The estimated OC emissions were 32.9 Tg (24.1-50.6 Tg as interquartile range), of which less than one third was anthropogenic in origin. Uncertainty resulted primarily from variations in EFOC. Asia, Africa, and South America had high emissions mainly because of residential biomass fuel burning or wildfires. Per-person OC emission in rural areas was three times that of urban areas because of the relatively high EFOC of residential solid fuels. Temporal trend of anthropogenic OC emissions depended on rural population, and was influenced primarily by residential crop residue and agricultural waste burning. Both the OC/PM2.5 ratio and emission intensity, defined as quantity of OC emissions per unit of fuel consumption for all sources, of anthropogenic OC followed a decreasing trend, indicating continuous improvement in combustion efficiency and control measures.

  11. Effect of nutrient sources on bench scale vinegar production using response surface methodology Efeito das fontes de nutrientes sobre a produção de vinagre em escala de bancada, usando-se a metodologia de superfície de resposta

    Directory of Open Access Journals (Sweden)

    Joelma M. Ferreira

    2005-03-01

    Full Text Available The present work aims to evaluate on a bench scale, the effects of nitrogen and phosphorous nutrient source concentrations in vinegar production, a process that is used by small scale industries in the State of Paraiba. The response surface methodology has been utilized for modeling and optimization of the fermentation process. Initially a 2³ complete factorial design was used, where the effects of initial concentrations of ethyl alcohol, phosphorous and nitrogen sources were observed. After this analysis the concentration range of the nutrient variables were extended and a two level plus a star configuration factorial experimental design was performed. The experimental values are well represented by the linear and quadratic model equations obtained. The optimum concentration of ethanol was 4% in which the yield and the productivity of the acetic acid were maximized to the values of 70% and 0.87 g L-1 h-1 respectively, for a 24 hours fermentation period. The evaluation of the quadratic models showed that the yield of vinegar is maximized from 28.1 to 51.04% and the productivity from 0.69 to 1.29 g L-1 h-1 when the concentration of the nitrogen nutrient in the medium is increased from 0.2 to 2.3 g mL-1. Thus, at the optimized nitrogen nutrient concentration both the yield and the productivity of the vinegar are increased by 1.85 times.Objetivou-se com o presente trabalho, estudar em escala de bancada, os efeitos de concentrações de fontes dos nutrientes nitrogênio e fósforo sobre a produção de vinagre de álcool, um processo muito utilizado nas indústrias de pequeno porte do Estado da Paraíba. A metodologia de superfície de resposta foi usada na modelagem e otimização de processo de fermentação acética. Inicialmente, a metodologia de planejamento fatorial completo 2³ foi utilizada, onde os efeitos das concentrações iniciais de etanol, de fontes de fósforo e de nitrogênio foram observados. Após esta análise as faixas das

  12. Nutrient fluxes from coastal California catchments with suburban development

    Science.gov (United States)

    Melack, J. M.; Leydecker, A.; Beighley, E.; Robinson, T.; Coombs, S.

    2005-12-01

    Numerous streams originate in the mountains fringing California's coast and transport nutrients into coastal waters. In central California, these streams traverse catchments with land covers including chaparral, grazed grasslands, orchards, industrial agriculture and suburban and urban development. Fluvial nutrient concentrations and fluxes vary as a function of these land covers and as a function of considerable fluctuations in rainfall. As part of a long-term investigation of mobilization and fluvial transport of nutrients in catchments bordering the Santa Barbara Channel we have intensively sampled nutrient concentrations and measured discharge during storm and base flows in multiple catchments and subcatchments. Volume-weighted mean concentrations of nitrate generally ranged from 5 to 25 micromolar in undeveloped areas, increased to about 100 micromolar for suburban and most agricultural catchments, and were in excess of 1000 micromolar in catchments with greenhouse-based agriculture. Phosphate concentrations ranged from 2 to 20 micromolar among the catchments. These data are used to examine the premise that the suburbanized portion of the catchments is the primary source of nutrients to the streams.

  13. Diverging Conclusions from the Same Meta-Analysis in Drug Safety: Source of Data (Primary Versus Secondary) Takes a Toll.

    Science.gov (United States)

    Prada-Ramallal, Guillermo; Takkouche, Bahi; Figueiras, Adolfo

    2017-04-01

    Meta-analyses of observational studies represent an important tool for assessing efficacy and safety in the pharmacoepidemiologic field. The data from the individual studies are either primary (i.e., collected through interviews or self-administered questionnaires) or secondary (i.e., collected from databases that were established for other purposes). So far, the origin of the data (primary vs. secondary) has not been systematically assessed as a source of heterogeneity in pharmacoepidemiologic meta-analyses. The aim was to assess the impact of considering the source of exposure data as a criterion in sensitivity and subgroup analysis on the conclusions of drug safety meta-analyses. We selected meta-analyses published between 2013 and 2015 in which the intake of frequently used over-the-counter medicines was either the main exposure or a concomitant treatment and the outcome had short latency and induction periods. We stratified the results by origin of data (primary vs. secondary) and compared the new results to those presented originally in the meta-analyses. We used four meta-analyses that fulfilled our criteria of inclusion. The results were selective serotonin reuptake inhibitors and upper gastrointestinal bleeding: original estimate odds ratio (OR) = 1.71 [95% confidence interval (CI) 1.44-2.04], OR primary data = 1.19 (95% CI 0.90-1.58), OR secondary data = 1.81 (95% CI 1.50-2.17); proton pump inhibitors and cardiac events: original estimate hazard ratio (HR) = 1.35 (95% CI 1.18-1.54), HR primary data = 1.05 (95% CI 0.87-1.26), HR secondary data = 1.43 (95% CI 1.23-1.66); non-aspirin non-steroidal anti-inflammatory drugs and myocardial infarction: original estimate risk ratio (RR) = 1.08 (95% CI 0.95-1.22), RR primary data = 0.57 (95% CI 0.34-0.96), RR secondary data = 1.15 (95% CI 1.03-1.28); paracetamol during pregnancy and childhood asthma: original estimate OR = 1.32 (95% CI 1.14-1.52), OR primary data = 1.23 (95% CI 1.06-1.42), OR

  14. Existing data sources for clinical epidemiology: Danish Cancer in Primary Care cohort

    Directory of Open Access Journals (Sweden)

    Jensen H

    2014-07-01

    Full Text Available Henry Jensen,1,2 Marie Louise Tørring,1 Mette Bach Larsen,3 Peter Vedsted11Research Unit for General Practice, Research Centre for Cancer Diagnosis in Primary Care, 2Section for General Medical Practice, Department of Public Health, Aarhus University, Aarhus C, 3Department of Public Health Programs, Randers Regional Hospital, Randers NOE, Denmark Background: In this paper, we describe the settings, content, and possibilities of the Danish Cancer in Primary Care (CaP cohort as well as some of the key findings so far. Further, we describe the future potential of the cohort as an international resource for epidemiological and health services research studies. Methods: The CaP cohort comprises information from three Danish subcohorts set up in 2004–2005, 2007–2008, and 2010 on newly diagnosed cancer patients aged 18 years or older. General practitioner (GP-reported and patient-reported data from six questionnaires generated information on causes and consequences of delayed diagnosis of cancer, and these data were supplemented with complete information on, eg, death, migration, health care utilization, medication use, and socioeconomic data from Denmark's comprehensive health and administrative registers. The cohort is followed up in terms of emigration, death, hospitalization, medication, and socioeconomics, and data are updated regularly. Results: In total, we identified 22,169 verified incident cancer cases. Completed GP questionnaires were returned for 17,566 (79% of the verified cases, and patient questionnaires were completed by 8,937 (40% respondents. Patients with participating GPs did not differ from patients with nonparticipating GPs in regard to one-year survival, comorbidity, or educational level. However, compared with nonparticipating GPs, patients listed with participating GPs were more likely to be women, younger, to have a higher disposable income, to have more regional or distant spread of tumors, were also more likely to have

  15. A Predictive Model for Microbial Counts on Beaches where Intertidal Sand is the Primary Source

    Science.gov (United States)

    Feng, Zhixuan; Reniers, Ad; Haus, Brian K.; Solo-Gabriele, Helena M.; Wang, John D.; Fleming, Lora E.

    2015-01-01

    Human health protection at recreational beaches requires accurate and timely information on microbiological conditions to issue advisories. The objective of this study was to develop a new numerical mass balance model for enterococci levels on nonpoint source beaches. The significant advantage of this model is its easy implementation, and it provides a detailed description of the cross-shore distribution of enterococci that is useful for beach management purposes. The performance of the balance model was evaluated by comparing predicted exceedances of a beach advisory threshold value to field data, and to a traditional regression model. Both the balance model and regression equation predicted approximately 70% the advisories correctly at the knee depth and over 90% at the waist depth. The balance model has the advantage over the regression equation in its ability to simulate spatiotemporal variations of microbial levels, and it is recommended for making more informed management decisions. PMID:25840869

  16. Primary versus secondary and anthropogenic versus natural sources of aminium ions in atmospheric particles during nine coastal and marine campaigns

    Science.gov (United States)

    Xie, H.; Yao, X.

    2017-12-01

    In this study, size-segregated dimethylaminium (DMA+) and trimethylaminium (TMA+) in atmospheric particles were measured during four coastal campaigns in Qingdao, China and five campaigns cruising over marginal seas of China and the northwest Pacific Ocean. The measured averages of DMA+ and TMA+ in PM0.056-10 (the sum of chemical concentrations from 0.056 to 10 µm) during each campaign, ranged from 0.045 to 1.1 nmol m-3 and from 0.029 to 0.53 nmol m-3, respectively. Size distributions of DMA+ and TMA+ in coastal atmospheric particles suggested that primary combustion emissions featured by mass median aerodynamic diameter (MMAD) at 0.2 µm generally yielded appreciable contributions to their observed concentrations in PM0.056-10 and sometimes dominantly contributed. In the marine atmospheres, the 0.1-0.2 µm modes of DMA+ and TMA+ also existed and sometimes dominated while they were very likely derived from primary ocean-biogenic emissions. In most of the samples during nine campaigns, secondarily-formed DMA+ and TMA+ in droplet mode with MMAD at 0.3-2 µm dominantly contributed to DMA+ and TMA+ in PM0.056-10. Overall, our results suggested that DMA+ and TMA+ in the marine atmospheric particles overwhelmingly came from ocean biogenic sources while they were likely derived from complicated anthropogenic and natural sources at the coastal sites.

  17. A station blackout simulation for the Advanced Neutron Source Reactor using the integrated primary and secondary system model

    International Nuclear Information System (INIS)

    Schneider, E.A.

    1994-01-01

    The Advanced Neutron Source Reactor (ANSR) is a research reactor to be built at Oak Ridge National Laboratory. This paper deals with thermal-hydraulic analysis of ANSR's cooling systems during nominal and transient conditions, with the major effort focusing upon the construction and testing of computer models of the reactor's primary, secondary and reflector vessel cooling systems. The code RELAP5 was used to simulate transients, such as loss of coolant accidents and loss of off-site power, as well as to model the behavior of the reactor in steady state. Three stages are involved in constructing and using a RELAP5 model: (1) construction and encoding of the desired model, (2) testing and adjustment of the model until a satisfactory steady state is achieved, and (3) running actual transients using the steady-state results obtained earlier as initial conditions. By use of the ANSR design specifications, a model of the reactor's primary and secondary cooling systems has been constructed to run a transient simulating a loss of off-site power. This incident assumes a pump coastdown in both the primary and secondary loops. The results determine whether the reactor can survive the transition from forced convection to natural circulation

  18. Line-Interactive Transformerless Uninterruptible Power Supply (UPS with a Fuel Cell as the Primary Source

    Directory of Open Access Journals (Sweden)

    Muhammad Iftikhar

    2018-03-01

    Full Text Available This paper presents line-interactive transformerless Uninterruptible Power Supply (UPS with a fuel cell as the prime energy source. The proposed UPS consists of three major parts (i.e., an output inverter, a unidirectional DC–DC converter, and a battery charger/discharger. Non-isolated topologies of both the unidirectional converter and battery charger/discharger ensure transformerless operation of the UPS system. A new topology of high gain converter is employed for boosting the low voltage of the fuel cell to a higher DC link voltage, with minimum semiconductor count, and high efficiency. A high-gain battery charger/discharger realizes the bidirectional operation between the DC link and the battery bank. Besides, it regulates the DC link voltage during the cold start of fuel cells and keeps the battery bank voltage to only 24 V. A new inverter control scheme is introduced that regulates the output voltage and minimizes the total harmonic distortion for non-linear loading condition. The proposed control scheme integrates proportional-resonant control with slide mode control, which improves the controller’s performance in transient conditions. The proposed UPS system is validated by developing a 1-kVA experimental prototype.

  19. A superconducting wavelength shifter as primary radiometric source standard in the X-ray range

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R. [Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, 10587 Berlin (Germany)], E-mail: roman.klein@ptb.de; Brandt, G.; Cibik, L.; Gerlach, M.; Krumrey, M.; Mueller, P.; Ulm, G. [Physikalisch-Technische Bundesanstalt, Abbestrasse 2-12, 10587 Berlin (Germany); Scheer, M. [BESSY GmbH, Albert-Einstein-Strasse 15, 12489 Berlin (Germany)

    2007-10-11

    For more than 20 years, the Physikalisch-Technische Bundesanstalt (PTB) has been using the calculable radiation of bending magnets from the BESSY I and BESSY II electron storage rings in the visible, UV, vacuum-UV (VUV) and X-ray spectral range for radiometry, especially for the calibration of radiation sources and energy-dispersive detectors. Due to its-compared to bending magnets-higher magnetic field, wavelength shifters (WLS) have the potential to extend the usable spectral range for these applications to higher photon energies. Thus, the characteristic energies of BESSY II bending magnet radiation and a 6 T WLS radiation are 2.5 and 11.5 keV, respectively. Within the scope of this work, the properties of the synchrotron radiation from the 6 T WLS have been investigated and compared to theoretical predictions for photon energies up to 150 keV. Good agreement within the experimental uncertainty of several percent was found. Further improvements for a future radiometric use of WLS radiation with low uncertainties will be discussed.

  20. A superconducting wavelength shifter as primary radiometric source standard in the X-ray range

    International Nuclear Information System (INIS)

    Klein, R.; Brandt, G.; Cibik, L.; Gerlach, M.; Krumrey, M.; Mueller, P.; Ulm, G.; Scheer, M.

    2007-01-01

    For more than 20 years, the Physikalisch-Technische Bundesanstalt (PTB) has been using the calculable radiation of bending magnets from the BESSY I and BESSY II electron storage rings in the visible, UV, vacuum-UV (VUV) and X-ray spectral range for radiometry, especially for the calibration of radiation sources and energy-dispersive detectors. Due to its-compared to bending magnets-higher magnetic field, wavelength shifters (WLS) have the potential to extend the usable spectral range for these applications to higher photon energies. Thus, the characteristic energies of BESSY II bending magnet radiation and a 6 T WLS radiation are 2.5 and 11.5 keV, respectively. Within the scope of this work, the properties of the synchrotron radiation from the 6 T WLS have been investigated and compared to theoretical predictions for photon energies up to 150 keV. Good agreement within the experimental uncertainty of several percent was found. Further improvements for a future radiometric use of WLS radiation with low uncertainties will be discussed

  1. A superconducting wavelength shifter as primary radiometric source standard in the X-ray range

    Science.gov (United States)

    Klein, R.; Brandt, G.; Cibik, L.; Gerlach, M.; Krumrey, M.; Müller, P.; Ulm, G.; Scheer, M.

    2007-10-01

    For more than 20 years, the Physikalisch-Technische Bundesanstalt (PTB) has been using the calculable radiation of bending magnets from the BESSY I and BESSY II electron storage rings in the visible, UV, vacuum-UV (VUV) and X-ray spectral range for radiometry, especially for the calibration of radiation sources and energy-dispersive detectors. Due to its—compared to bending magnets—higher magnetic field, wavelength shifters (WLS) have the potential to extend the usable spectral range for these applications to higher photon energies. Thus, the characteristic energies of BESSY II bending magnet radiation and a 6 T WLS radiation are 2.5 and 11.5 keV, respectively. Within the scope of this work, the properties of the synchrotron radiation from the 6 T WLS have been investigated and compared to theoretical predictions for photon energies up to 150 keV. Good agreement within the experimental uncertainty of several percent was found. Further improvements for a future radiometric use of WLS radiation with low uncertainties will be discussed.

  2. Effects of agricultural subsidies of nutrients and detritus on fish and plankton of shallow-reservoir ecosystems.

    Science.gov (United States)

    Pilati, Alberto; Vanni, Michael J; González, María J; Gaulke, Alicia K

    2009-06-01

    Agricultural activities increase exports of nutrients and sediments to lakes, with multiple potential impacts on recipient ecosystems. Nutrient inputs enhance phytoplankton and upper trophic levels, and sediment inputs can shade phytoplankton, interfere with feeding of consumers, and degrade benthic habitats. Allochthonous sediments are also a potential food source for detritivores, as is sedimenting autochthonous phytodetritus, the production of which is stimulated by nutrient inputs. We examined effects of allochthonous nutrient and sediment subsidies on fish and plankton, with special emphasis on gizzard shad (Dorosoma cepedianum). This widespread and abundant omnivorous fish has many impacts on reservoir ecosystems, including negative effects on water quality via nutrient cycling and on fisheries via competition with sportfish. Gizzard shad are most abundant in agriculturally impacted, eutrophic systems; thus, agricultural subsidies may affect reservoir food webs directly and by enhancing gizzard shad biomass. We simulated agricultural subsidies of nutrients and sediment detritus by manipulating dissolved nutrients and allochthonous detritus in a 2 x 2 factorial design in experimental ponds. Addition of nutrients alone increased primary production and biomass of zooplanktivorous fish (bluegill and young-of-year gizzard shad). Addition of allochthonous sediments alone increased algal sedimentation and decreased seston and sediment C:P ratios. Ponds receiving both nutrients and sediments showed highest levels of phytoplankton and total phosphorus. Adult and juvenile gizzard shad biomass was enhanced equally by nutrient or sediment addition, probably because this apparently P-limited detritivore ingested similar amounts of P in all subsidy treatments. Nutrient excretion rates of gizzard shad were higher in ponds with nutrient additions, where sediments were composed mainly of phytodetritus. Therefore, gizzard shad can magnify the direct effects of nutrient

  3. Sources

    International Nuclear Information System (INIS)

    Duffy, L.P.

    1991-01-01

    This paper discusses the sources of radiation in the narrow perspective of radioactivity and the even narrow perspective of those sources that concern environmental management and restoration activities at DOE facilities, as well as a few related sources. Sources of irritation, Sources of inflammatory jingoism, and Sources of information. First, the sources of irritation fall into three categories: No reliable scientific ombudsman to speak without bias and prejudice for the public good, Technical jargon with unclear definitions exists within the radioactive nomenclature, and Scientific community keeps a low-profile with regard to public information. The next area of personal concern are the sources of inflammation. This include such things as: Plutonium being described as the most dangerous substance known to man, The amount of plutonium required to make a bomb, Talk of transuranic waste containing plutonium and its health affects, TMI-2 and Chernobyl being described as Siamese twins, Inadequate information on low-level disposal sites and current regulatory requirements under 10 CFR 61, Enhanced engineered waste disposal not being presented to the public accurately. Numerous sources of disinformation regarding low level radiation high-level radiation, Elusive nature of the scientific community, The Federal and State Health Agencies resources to address comparative risk, and Regulatory agencies speaking out without the support of the scientific community

  4. The oral cavity is not a primary source for implantable pacemaker or cardioverter defibrillator infections

    Science.gov (United States)

    2013-01-01

    Background To test the hypothesis that the oral cavity is a potential source for implantable pacemaker and cardioverter defibrillators infections, the bacterial diversity on explanted rhythm heart management devices was investigated and compared to the oral microbiome. Methods A metagenomic approach was used to analyze the bacterial diversity on the surfaces of non-infected and infected pacemakers. The DNA from surfaces swaps of 24 non-infected and 23 infected pacemaker were isolated and subjected to bacterial-specific DNA amplification, single strand conformation polymorphism- (SSCP) and sequencing analysis. Species-specific primer sets were used to analyze for any correlation between bacterial diversity on pacemakers and in the oral cavity. Results DNA of bacterial origin was detected in 21 cases on infected pacemakers and assigned to the bacterial phylotypes Staphylococcus epidermidis, Propionibacterium acnes, Staphylococcus aureus, Staphylococcus schleiferi and Stapyhlococcus. In 17 cases bacterial DNA was found on pacemakers with no clinical signs of infections. On the basis of the obtained sequence data, the phylotypes Propionibacterium acnes, Staphylococcus and an uncultured bacterium were identified. Propionibacterium acnes and Staphylococcus epidermidis were the only bacteria detected in pacemeaker (n = 25) and oral samples (n = 11). Conclusions The frequency of the coincidental detection of bacteria on infected devices and in the oral cavity is low and the detected bacteria are highly abundant colonizers of non-oral human niches. The transmission of oral bacteria to the lead or device of implantable pacemaker or cardioverter defibrillators is unlikely relevant for the pathogenesis of pacemaker or cardioverter defibrillators infections. PMID:23575037

  5. Clinical performance of dual-source computerized tomography (DSCT) in primary diagnostics of coronary heart diseases

    International Nuclear Information System (INIS)

    Brunner, H.; Froehner, S.; Wagner, M.; Schmitt, R.; Brunn, J.; Gietzen, F.H.; Kerber, S.

    2008-01-01

    Dual-source-CT-technology (DSCT) improves temporal resolution of cardiac computed tomography to 83 ms per heart-phase. In this study, the clinical performance of this new method is evaluated. Materials and Methods: In fifty patients (33 male, 17 female; age 50±13 years) with suspected coronary heart disease, CT angiography (slice thickness 0,75 mm, contrast-agent 60-80 ml iomeprol) was performed with a Somatom Definition scanner. Based on the coronary 15-segment-model of the AHA, scores for image quality and lumen reduction were established to enable the observer, to give recommendations for further therapy. Results: Out of 750 possible AHA-segments, 655 were depicted (87,3%). 591 segments (90,2%) were assessed without any limitation of quality, 49 (7,5%) segments showed moderate, and 15 (2,3%) segments severe limitation in image quality. 508 (77,6%) segments were without pathological findings, 92 (14,0%) segments had minimal atherosclerotic lesions, 42 (6,4%) segments suffered from stenoses with lumen reduction less than 70%, and 13 (2,0%) showed significant stenoses of more than 70%. In 31 patients (62%), coronary heart disease was ruled out by CT angiography without any need for further non-invasive or invasive diagnostics. 8 patients (16%) underwent stress-testing for ischemia. In 11 (22%) patients coronary angiography was recommended, and DSCT findings were confirmed in 10 cases. Only one LCx stenosis was overestimated in DSCT. Conclusion: Contrast-enhanced DSCT is a powerful tool in diagnosis of coronary heart disease. 98% of coronary segments could be assessed in diagnostic quality, and at least 90% of haemodynamically significant coronary stenoses were detected. (orig.)

  6. Treated Olive Cake as a Non-forage Fiber Source for Growing Awassi Lambs: Effects on Nutrient Intake, Rumen and Urine pH, Performance, and Carcass Yield.

    Science.gov (United States)

    Awawdeh, M S; Obeidat, B S

    2013-05-01

    The objective of this study was to investigate the effects of partial replacement of wheat hay with sun-dried (SOC) or acid-treated SOC (ASOC) olive cake on nutrient intake and performance of Awassi lambs. An additional objective was to study the effects of acid treatment of olive cake (OC) on its chemical composition and nutritive value. On DM basis, sun-drying of OC did not dramatically affect its chemical composition. On the other hand, treating SOC with phosphoric acid decreased (pcomparison with the CTL diet, but not different from the ASOC diet. Additionally, lambs fed the SOC diet had greater (p = 0.03) hot and cold carcass weights than the ASOC diet, but not different from the CTL diet. However, feed conversion ratios and dressing percentages were similar among dietary treatments. In conclusion, replacing half of dietary wheat hay with SOC improved performance of Awassi lambs with no detrimental effects on nutrients intake or digestibility. No further improvements in the nutritive value of SOC and lambs performance were detected when SOC was treated with acid.

  7. Age and geochemistry of the Newania dolomite carbonatites, India: implications for the source of primary carbonatite magma

    Science.gov (United States)

    Ray, Jyotiranjan S.; Pande, Kanchan; Bhutani, Rajneesh; Shukla, Anil D.; Rai, Vinai K.; Kumar, Alok; Awasthi, Neeraj; Smitha, R. S.; Panda, Dipak K.

    2013-12-01

    The Newania carbonatite complex of India is one of the few dolomite-dominated carbonatites of the world. Intruding into Archean basement gneisses, the rocks of the complex have undergone limited diversification and are not associated with any alkaline silicate rock. Although the magmatic nature of the complex was generally accepted, its age of emplacement had remained equivocal because of the disturbed nature of radioisotope systems. Many questions about the nature of its mantle source and mode of origin had remained unanswered because of lack of geochemical and isotopic data. Here, we present results of our effort to date the complex using 147Sm-143Nd, 207Pb-206Pb and 40Ar-39Ar dating techniques. We also present mineral chemistry, major and trace element geochemistry and Sr-Nd isotopic ratio data for these carbonatites. Our age data reveal that the complex was emplaced at ~1,473 Ma and parts of it were affected by a thermal event at ~904 Ma. The older 207Pb-206Pb ages reported here (~2.4 Ga) and by one earlier study (~2.3 Ga; Schleicher et al. Chem Geol 140:261-273, 1997) are deemed to be a result of heterogeneous incorporation of crustal Pb during the post-emplacement thermal event. The thermal event had little effect on many magmatic signatures of these rocks, such as its dolomite-magnesite-ankerite-Cr-rich magnetite-magnesio-arfvedsonite-pyrochlore assemblage, mantle like δ13C and δ18O and typical carbonatitic trace element patterns. Newania carbonatites show fractional crystallization trend from high-Mg to high-Fe through high-Ca compositions. The least fractionated dolomite carbonatites of the complex possess very high Mg# (≥80) and have similar major element oxide contents as that of primary carbonatite melts experimentally produced from peridotitic sources. In addition, lower rare earth element (and higher Sr) contents than a typical calcio-carbonatite and mantle like Nb/Ta ratios indicate that the primary magma for the complex was a magnesio

  8. Artifact correction and source analysis of early electroencephalographic responses evoked by transcranial magnetic stimulation over primary motor cortex.

    Science.gov (United States)

    Litvak, Vladimir; Komssi, Soile; Scherg, Michael; Hoechstetter, Karsten; Classen, Joseph; Zaaroor, Menashe; Pratt, Hillel; Kahkonen, Seppo

    2007-08-01

    Analyzing the brain responses to transcranial magnetic stimulation (TMS) using electroencephalography (EEG) is a promising method for the assessment of functional cortical connectivity and excitability of areas accessible to this stimulation. However, until now it has been difficult to analyze the EEG responses during the several tens of milliseconds immediately following the stimulus due to TMS-induced artifacts. In the present study we show that by combining a specially adapted recording system with software artifact correction it is possible to remove a major part of the artifact and analyze the cortical responses as early as 10 ms after TMS. We used this methodology to examine responses of left and right primary motor cortex (M1) to TMS at different intensities. Based on the artifact-corrected data we propose a model for the cortical activation following M1 stimulation. The model revealed the same basic response sequence for both hemispheres. A large part of the response could be accounted for by two sources: a source close to the stimulation site (peaking approximately 15 ms after the stimulus) and a midline frontal source ipsilateral to the stimulus (peaking approximately 25 ms). In addition the model suggests responses in ipsilateral temporo-parietal junction areas (approximately 35 ms) and ipsilateral (approximately 30 ms) and middle (approximately 50 ms) cerebellum. Statistical analysis revealed significant dependence on stimulation intensity for the ipsilateral midline frontal source. The methodology developed in the present study paves the way for the detailed study of early responses to TMS in a wide variety of brain areas.

  9. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  10. Characterization of the primary source of electrons in linear accelerators in clinical use; Caracterizacion de la fuente primaria de electrones en aceleradores lineales de uso clinico

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Extremera, M.; Gonzalez Infantes, W.; Lallena rojo, A. M.; Anguiano Millan, M.

    2013-07-01

    Monte Carlo simulation is currently considered the most accurate method for calculations of doses due to electrons. The objective of the work is the characterization of the primary source of electrons from an accelerator of clinical use with Monte Carlo simulation, in order to build a model of sources involving a substantial saving of time of calculation in the simulation of treatment. (Author)

  11. Biotechnologies for critical raw material recovery from primary and secondary sources: R&D priorities and future perspectives.

    Science.gov (United States)

    Hennebel, Tom; Boon, Nico; Maes, Synthia; Lenz, Markus

    2015-01-25

    Europe is confronted with an increasing supply risk of critical raw materials. These can be defined as materials of which the risks of supply shortage and their impacts on the economy are higher compared to most of other raw materials. Within the framework of the EU Innovation Partnership on raw materials Initiative, a list of 14 critical materials was defined, including some bulk metals, industrial minerals, the platinum group metals and rare earth elements. To tackle the supply risk challenge, innovation is required with respect to sustainable primary mining, substitution of critical metals, and urban mining. In these three categories, biometallurgy can play a crucial role. Indeed, microbe-metal interactions have been successfully applied on full scale to win materials from primary sources, but are not sufficiently explored for metal recovery or recycling. On the one hand, this article gives an overview of the microbial strategies that are currently applied on full scale for biomining; on the other hand it identifies technologies, currently developed in the laboratory, which have a perspective for large scale metal recovery and the needs and challenges on which bio-metallurgical research should focus to achieve this ambitious goal. Copyright © 2013. Published by Elsevier B.V.

  12. Controls of event-based nutrient transport within nested headwater agricultural watersheds of the western Lake Erie basin

    Science.gov (United States)

    Williams, Mark R.; Livingston, Stanley J.; Penn, Chad J.; Smith, Douglas R.; King, Kevin W.; Huang, Chi-hua

    2018-04-01

    Understanding the processes controlling nutrient delivery in headwater agricultural watersheds is essential for predicting and mitigating eutrophication and harmful algal blooms in receiving surface waters. The objective of this study was to elucidate nutrient transport pathways and examine key components driving nutrient delivery processes during storm events in four nested agricultural watersheds (298-19,341 ha) in the western Lake Erie basin with poorly drained soils and an extensive artificial drainage network typical of the Midwestern U.S. Concentration-discharge hysteresis patterns of nitrate-nitrogen (NO3-N), dissolved reactive phosphorus (DRP), and particulate phosphorus (PP) occurring during 47 storm events over a 6 year period (2004-2009) were evaluated. An assessment of the factors producing nutrient hysteresis was completed following a factor analysis on a suite of measured environmental variables representing the fluvial and wider watershed conditions prior to, and during the monitored storm events. Results showed the artificial drainage network (i.e., surface tile inlets and subsurface tile drains) in these watersheds was the primary flow pathway for nutrient delivery to streams, but nutrient behavior and export during storm events was regulated by the flow paths to and the intensity of the drainage network, the availability of nutrients, and the relative contributions of upland and in-stream nutrient sources. Potential sources and flow pathways for transport varied among NO3-N, PP, and DRP with results underscoring the challenge of mitigating nutrient loss in these watersheds. Conservation practices addressing both nutrient management and hydrologic connectivity will likely be required to decrease nutrient loss in artificially drained landscapes.

  13. A comparative study of methanol as a supplementary carbon source for enhancing denitrification in primary and secondary anoxic zones.

    Science.gov (United States)

    Ginige, Maneesha P; Bowyer, Jocelyn C; Foley, Leah; Keller, Jürg; Yuan, Zhiguo

    2009-04-01

    A comparative study on the use of methanol as a supplementary carbon source to enhance denitrification in primary and secondary anoxic zones is reported. Three lab-scale sequencing batch reactors (SBR) were operated to achieve nitrogen and carbon removal from domestic wastewater. Methanol was added to the primary anoxic period of the first SBR, and to the secondary anoxic period of the second SBR. No methanol was added to the third SBR, which served as a control. The extent of improvement on the denitrification performance was found to be dependent on the reactor configuration. Addition to the secondary anoxic period is more effective when very low effluent nitrate levels are to be achieved and hence requires a relatively large amount of methanol. Adding a small amount of methanol to the secondary anoxic period may cause nitrite accumulation, which does not improve overall nitrogen removal. In the latter case, methanol should be added to the primary anoxic period. The addition of methanol can also improve biological phosphorus removal by creating anaerobic conditions and increasing the availability of organic carbon in wastewater for polyphosphate accumulating organisms. This potentially provides a cost-effective approach to phosphorus removal from wastewater with a low carbon content. New fluorescence in situ hybridisation (FISH) probes targeting methanol-utilising denitrifiers were designed using stable isotope probing. Microbial structure analysis of the sludges using the new and existing FISH probes clearly showed that the addition of methanol stimulated the growth of specific methanol-utilizing denitrifiers, which improved the capability of sludge to use methanol and ethanol for denitrification, but reduced its capability to use wastewater COD for denitrification. Unlike acetate, long-term application of methanol has no negative impact on the settling properties of the sludge.

  14. Nutrient variations and isotopic evidences of particulate organic matter provenance in fringing reefs, South China

    International Nuclear Information System (INIS)

    Cao, Di; Cao, Wenzhi; Liang, Ying; Huang, Zheng

    2016-01-01

    Nutrient over-enrichment is considered to be one of the causes of coral decline. Increase in traditional fishing in the Xuwen National Coral Reefs Reserve tract (XW) and tourism around the Sanya National Coral Reefs Reserve tract (SY) are causing this coral decline. This study reviews the current state of knowledge of the nutrient status of coastal fringing reefs in South China and evaluates the primary sources of nutrients using stable isotope method. Surveys of seawater nutrients showed that the seawater remained clean in both the XW and SY coastal coral reef areas. Based on the isotopic differences between anthropogenic sewage and naturally occurring aquatic nutrients, the isotopic values of particulate organic matter (POM) and the C/N ratios were successfully used to identify the presence of anthropogenic nutrients in aquatic environments. The δ"1"3C, δ"1"5N and C/N compositions of POM from XW and SY (− 21.18 ± 2.11‰, 10.30 ± 5.54‰, and 5.35 ± 0.69 and − 20.80 ± 1.34‰, 7.06 ± 3.95‰, and 5.77 ± 2.15, respectively) showed statistically significant variations with the season. The δ"1"3C and δ"1"5N values of POM suggest marine and terrestrial-derived nutrient sources. Organic carbon is a mixture of marine phytoplankton, marine benthic algae and terrestrial-derived plants. The δ"1"5N values suggest terrestrial-derived sewage and upwelling-dominated nitrogen sources. In the presence of natural upwelling and coastal currents, coastal coral reef areas are more vulnerable to the increasing anthropogenic nutrient inputs. Anthropogenic activities might lead to large increases in the nutrient concentrations and could trigger the shift from coral- to macroalgae-dominated ecosystems, which would ultimately result in the degradation of the coastal coral reef ecosystem. These results provide some understanding of the declining coral reef ecosystem and the importance of conservation areas and coastal coral reef resource management. - Highlights: • The

  15. Nutrient variations and isotopic evidences of particulate organic matter provenance in fringing reefs, South China

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Di; Cao, Wenzhi, E-mail: wzcao@xmu.edu.cn; Liang, Ying; Huang, Zheng

    2016-10-01

    Nutrient over-enrichment is considered to be one of the causes of coral decline. Increase in traditional fishing in the Xuwen National Coral Reefs Reserve tract (XW) and tourism around the Sanya National Coral Reefs Reserve tract (SY) are causing this coral decline. This study reviews the current state of knowledge of the nutrient status of coastal fringing reefs in South China and evaluates the primary sources of nutrients using stable isotope method. Surveys of seawater nutrients showed that the seawater remained clean in both the XW and SY coastal coral reef areas. Based on the isotopic differences between anthropogenic sewage and naturally occurring aquatic nutrients, the isotopic values of particulate organic matter (POM) and the C/N ratios were successfully used to identify the presence of anthropogenic nutrients in aquatic environments. The δ{sup 13}C, δ{sup 15}N and C/N compositions of POM from XW and SY (− 21.18 ± 2.11‰, 10.30 ± 5.54‰, and 5.35 ± 0.69 and − 20.80 ± 1.34‰, 7.06 ± 3.95‰, and 5.77 ± 2.15, respectively) showed statistically significant variations with the season. The δ{sup 13}C and δ{sup 15}N values of POM suggest marine and terrestrial-derived nutrient sources. Organic carbon is a mixture of marine phytoplankton, marine benthic algae and terrestrial-derived plants. The δ{sup 15}N values suggest terrestrial-derived sewage and upwelling-dominated nitrogen sources. In the presence of natural upwelling and coastal currents, coastal coral reef areas are more vulnerable to the increasing anthropogenic nutrient inputs. Anthropogenic activities might lead to large increases in the nutrient concentrations and could trigger the shift from coral- to macroalgae-dominated ecosystems, which would ultimately result in the degradation of the coastal coral reef ecosystem. These results provide some understanding of the declining coral reef ecosystem and the importance of conservation areas and coastal coral reef resource management

  16. Nutrient cycling strategies.

    NARCIS (Netherlands)

    Breemen, van N.

    1995-01-01

    This paper briefly reviews pathways by which plants can influence the nutrient cycle, and thereby the nutrient supply of themselves and of their competitors. Higher or lower internal nutrient use efficiency positively feeds back into the nutrient cycle, and helps to increase or decrease soil

  17. Growth Responses of Three Dominant Wetland Plant Species to Various Flooding and Nutrient Levels

    Science.gov (United States)

    Barrett, S.; Shaffer, G. P.

    2017-12-01

    Coastal Louisiana is experiencing a greater rate of wetland loss than any other wetland system in the United States. This is primarily due to anthropogenic stressors such as flood control levees, backfilling and development of wetlands, and other hydrologic modifications. Methods employed to mitigate wetland loss include the construction of river diversions and assimilation wetlands, which can provide consistent sources of freshwater influx and nutrients to impounded swamps and marshes. It is well known that prolonged flooding causes strain on wetland plant communities and facilitates or exacerbates wetland degradation. However, because river diversions and assimilation wetlands bring high nutrient loads along with freshwater, there is debate over whether prolonged flooding or high influx of nutrients is the primary cause of stress in river diversion and assimilation wetland discharge areas. This mesocosm experiment addresses this question by isolating the effects of flooding and nutrients on the biomass of baldcypress (Taxodium distichum), maidencane (Panicum hemitomon), and cordgrass (Spartina patens) over the course of a growing season. The results of this study provide clarity as to whether flooding stress, high nutrient loads, or both cause a reduction in wetland plant productivity. By evaluating the growth responses of T. distichum, P. hemitomon, and S. patens at varying nutrient regimes, we gain insight on how these more dominant species will react to high nutrient discharges from large river diversions, such as those proposed in Louisiana's 2017 Master Plan.

  18. Spatiotemporal patterns of livestock manure nutrient production in the conterminous United States from 1930 to 2012

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qichun, E-mail: qichun.yang@pnnl.gov [International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849 (United States); Joint Global Change Research Institute, Pacific Northwest National Lab, College Park, MD 20740 (United States); Tian, Hanqin, E-mail: tianhan@auburn.edu [International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849 (United States); Li, Xia [International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849 (United States); Ren, Wei [International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849 (United States); Department of Plant & Soil Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40506 (United States); Zhang, Bowen [International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849 (United States); Zhang, Xuesong [Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 (United States); Wolf, Julie [Joint Global Change Research Institute, Pacific Northwest National Lab, College Park, MD 20740 (United States)

    2016-01-15

    Manure nitrogen (N) and phosphorus (P) from livestock husbandry are important components of terrestrial biogeochemical cycling. Assessment of the impacts of livestock manure on terrestrial biogeochemistry requires a compilation and analysis of spatial and temporal patterns of manure nutrients. In this study, we reconstructed county-level manure nutrient data of the conterminous United States (U.S.) in 4- to 5-year increments from 1930 to 2012. Manure N and P were 5.89 ± 0.64 Tg N yr.{sup −1} (Mean ± Standard Deviation) and 1.73 ± 0.29 Tg P yr.{sup −1} (1 Tg = 10{sup 12} g), and increased by 46% and 92% from 1930 to 2012, respectively. Prior to 1970, manure provided more N to the U.S. lands than chemical fertilizer use. Since 1970, however, increasing chemical N fertilizer use has exceeded manure N production. Manure was the primary P source in the U.S. during 1930–1969 and 1987–2012, but was lower than P fertilizer use in 1974, 1978, and 1982. High-nutrient-production regions shifted towards eastern and western areas of the U.S. Decreasing small farms and increasing Concentrated Animal Feeding Operations (CAFOs) induced concentrated spatial patterns in manure nutrient loads. Counties with cattle or poultry as the primary manure nutrient contributors expanded significantly from 1930 to 2012, whereas regions with sheep and hog as the primary contributors decreased. We identified regions facing environmental threats associated with livestock farming. Effective management of manure should consider the impacts of CAFOs in manure production, and changes in livestock population structure. The long-term county-level manure nutrient dataset provides improved spatial and temporal information on manure nutrients in the U.S. This dataset is expected to help advance research on nutrient cycling, ammonia volatilization, greenhouse gas (GHG) emissions from livestock husbandry, recovery and reuse of manure nutrients, and impacts of livestock feeding on human health in

  19. Spatiotemporal patterns of livestock manure nutrient production in the conterminous United States from 1930 to 2012

    International Nuclear Information System (INIS)

    Yang, Qichun; Tian, Hanqin; Li, Xia; Ren, Wei; Zhang, Bowen; Zhang, Xuesong; Wolf, Julie

    2016-01-01

    Manure nitrogen (N) and phosphorus (P) from livestock husbandry are important components of terrestrial biogeochemical cycling. Assessment of the impacts of livestock manure on terrestrial biogeochemistry requires a compilation and analysis of spatial and temporal patterns of manure nutrients. In this study, we reconstructed county-level manure nutrient data of the conterminous United States (U.S.) in 4- to 5-year increments from 1930 to 2012. Manure N and P were 5.89 ± 0.64 Tg N yr. −1 (Mean ± Standard Deviation) and 1.73 ± 0.29 Tg P yr. −1 (1 Tg = 10 12 g), and increased by 46% and 92% from 1930 to 2012, respectively. Prior to 1970, manure provided more N to the U.S. lands than chemical fertilizer use. Since 1970, however, increasing chemical N fertilizer use has exceeded manure N production. Manure was the primary P source in the U.S. during 1930–1969 and 1987–2012, but was lower than P fertilizer use in 1974, 1978, and 1982. High-nutrient-production regions shifted towards eastern and western areas of the U.S. Decreasing small farms and increasing Concentrated Animal Feeding Operations (CAFOs) induced concentrated spatial patterns in manure nutrient loads. Counties with cattle or poultry as the primary manure nutrient contributors expanded significantly from 1930 to 2012, whereas regions with sheep and hog as the primary contributors decreased. We identified regions facing environmental threats associated with livestock farming. Effective management of manure should consider the impacts of CAFOs in manure production, and changes in livestock population structure. The long-term county-level manure nutrient dataset provides improved spatial and temporal information on manure nutrients in the U.S. This dataset is expected to help advance research on nutrient cycling, ammonia volatilization, greenhouse gas (GHG) emissions from livestock husbandry, recovery and reuse of manure nutrients, and impacts of livestock feeding on human health in the context of

  20. Primary sink and source of geogenic arsenic in sedimentary aquifers in the southern Choushui River alluvial fan, Taiwan

    International Nuclear Information System (INIS)

    Lu, Kuang-Liang; Liu, Chen-Wuing; Wang, Sheng-Wei; Jang, Cheng-Shin; Lin, Kao-Hung; Liao, Vivian Hsiu-Chuan; Liao, Chung-Min; Chang, Fi-John

    2010-01-01

    This work characterized the sink and source/mobility of As in the As-affected sedimentary aquifers of the southern Choushui River alluvial fan, central Taiwan. Major mineral phases and chemical components were determined by XRD and X-ray photoelectron spectroscopy (XPS). The partitioning of As and Fe among cores were determined by sequential extraction. Based on XPS results, the primary forms of Fe were hematite, goethite and magnetite. Sequential extraction data and the XRF analysis indicated that Fe oxyhydroxides and sulfides were likely to be the major sinks of As, particularly in the distal-fan. Furthermore, Fe oxyhydroxides retained higher As contents than As-bearing sulfides. The reductive dissolution of Fe oxyhydroxides, which accompanied high levels of HCO 3 - and NH 4 + concentrations, was likely the principal release mechanism of As into groundwater in this area. The dual roles of Fe oxyhydroxides which are governed by the local redox condition act as a sink and source in the aquifer. Ionic replacement by PO 4 3- and HCO 3 - along with seasonal water table fluctuation, caused by monsoons and excessive pumping, contributed specific parts of As in the groundwater. The findings can be used to account for the inconsistency between Fe and As concentrations observed in groundwater.

  1. Morphology, composition, and mixing state of primary particles from combustion sources - crop residue, wood, and solid waste.

    Science.gov (United States)

    Liu, Lei; Kong, Shaofei; Zhang, Yinxiao; Wang, Yuanyuan; Xu, Liang; Yan, Qin; Lingaswamy, A P; Shi, Zongbo; Lv, Senlin; Niu, Hongya; Shao, Longyi; Hu, Min; Zhang, Daizhou; Chen, Jianmin; Zhang, Xiaoye; Li, Weijun

    2017-07-11

    Morphology, composition, and mixing state of individual particles emitted from crop residue, wood, and solid waste combustion in a residential stove were analyzed using transmission electron microscopy (TEM). Our study showed that particles from crop residue and apple wood combustion were mainly organic matter (OM) in smoldering phase, whereas soot-OM internally mixed with K in flaming phase. Wild grass combustion in flaming phase released some Cl-rich-OM/soot particles and cardboard combustion released OM and S-rich particles. Interestingly, particles from hardwood (pear wood and bamboo) and softwood (cypress and pine wood) combustion were mainly soot and OM in the flaming phase, respectively. The combustion of foam boxes, rubber tires, and plastic bottles/bags in the flaming phase released large amounts of soot internally mixed with a small amount of OM, whereas the combustion of printed circuit boards and copper-core cables emitted large amounts of OM with Br-rich inclusions. In addition, the printed circuit board combustion released toxic metals containing Pb, Zn, Sn, and Sb. The results are important to document properties of primary particles from combustion sources, which can be used to trace the sources of ambient particles and to know their potential impacts in human health and radiative forcing in the air.

  2. The Future of Nuclear Energy As a Primary Source for Clean Hydrogen Energy System in Developing Countries

    International Nuclear Information System (INIS)

    Ahmed, K.; Shaaban, H.

    2007-01-01

    The limited availability of fossil fuels compared to the increasing demand and the connected environmental questions have become topics of growing importance and international attention. Many other clean alternative sources of energy are available, but most of them are either relatively undeveloped technologically or are not yet fully utilized. Also, there is a need for a medium which can carry the produced energy to the consumer in a convenient and environmentally acceptable way. In this study, a fission reactor as a primary energy source with hydrogen as an energy carrier is suggested. An assessment of hydrogen production from nuclear energy is presented. A complete nuclear-electro-hydrogen energy system is proposed for a medium size city (population of 500,000). The whole energy requirement is assessed including residential, industrial and transportation energies. A preliminary economical and environmental impact study is performed on the proposed system. The presented work could be used as a nucleus for a feasibility study for applying this system in any newly established city

  3. Fontes de energia em suplementos múltiplos para bezerros Nelore em creep-feeding: desempenho produtivo, consumo e digestibilidade dos nutrientes Energy sources in multiple supplements for Nellore calves in creep-feeding: productive performance, nutrient intake and digestibility

    Directory of Open Access Journals (Sweden)

    Marlos Oliveira Porto

    2009-07-01

    Full Text Available Avaliaram-se o desempenho produtivo, o consumo e a digestibilidade em bezerros Nelore em fase de amamentação em pastagem de Brachiaria decumbens suplementada com diferentes fontes de energia. A área foi dividida em cinco piquetes de 6,8 ha, com disponibilidade média de matéria seca e matéria seca potencialmente digestível de 4,10 e 2,38 t/ha, respectivamente. Foram utilizados 45 bezerros Nelore, com peso e idade iniciais de 96,0 ± 11,0 kg e 101 ± 12 dias, em delineamento inteiramente casualizado, em arranjo fatorial 5 × 2 (cinco suplementos e dois sexos. Os suplementos foram: MM - mistura mineral (controle; GM - farelo de soja (FS + grão de milho triturado (GM e mistura mineral; FTGM - farelo de soja + farelo de trigo + grão de milho triturado e mistura mineral; FA - farelo de soja + farelo de arroz e mistura mineral; GMS - farelo de soja + grão de milho triturado + grão de sorgo triturados e mistura mineral, fornecidos diariamente na quantidade de 60 g/animal para o grupo controle e 500 g/animal para os demais suplementos. Os animais que receberam suplemento múltiplo com milho e sorgo como fonte de energia proporcionaram ganho diário médio adicional de 100 g/animal (16,39% em comparação à mistura mineral. O uso do suplemento múltiplo à base de grão de milho como fonte de energia reduziu o consumo de matéria seca, matéria orgânica de pasto e fibra em detergente neutro em relação às fontes energéticas farelo de arroz e à combinação de milho com sorgo. A suplementação com as fontes de energia, sobretudo as combinações de farelo de trigo e milho ou de milho e sorgo, podem proporcionar ganhos adicionais em animais em creep-feeding. A suplementação múltipla aumenta o consumo de pasto quando se utilizam grão de milho e sorgo combinados como fonte de energia.The performance, intake and digestibility were evaluated in Nellore beef calves supplemented with different energy sources in Brachiaria decumbens pasture

  4. Estimating Vegetation Primary Production in the Heihe River Basin of China with Multi-Source and Multi-Scale Data.

    Directory of Open Access Journals (Sweden)

    Tianxiang Cui

    Full Text Available Estimating gross primary production (GPP and net primary production (NPP are significant important in studying carbon cycles. Using models driven by multi-source and multi-scale data is a promising approach to estimate GPP and NPP at regional and global scales. With a focus on data that are openly accessible, this paper presents a GPP and NPP model driven by remotely sensed data and meteorological data with spatial resolutions varying from 30 m to 0.25 degree and temporal resolutions ranging from 3 hours to 1 month, by integrating remote sensing techniques and eco-physiological process theories. Our model is also designed as part of the Multi-source data Synergized Quantitative (MuSyQ Remote Sensing Production System. In the presented MuSyQ-NPP algorithm, daily GPP for a 10-day period was calculated as a product of incident photosynthetically active radiation (PAR and its fraction absorbed by vegetation (FPAR using a light use efficiency (LUE model. The autotrophic respiration (Ra was determined using eco-physiological process theories and the daily NPP was obtained as the balance between GPP and Ra. To test its feasibility at regional scales, our model was performed in an arid and semi-arid region of Heihe River Basin, China to generate daily GPP and NPP during the growing season of 2012. The results indicated that both GPP and NPP exhibit clear spatial and temporal patterns in their distribution over Heihe River Basin during the growing season due to the temperature, water and solar influx conditions. After validated against ground-based measurements, MODIS GPP product (MOD17A2H and results reported in recent literature, we found the MuSyQ-NPP algorithm could yield an RMSE of 2.973 gC m(-2 d(-1 and an R of 0.842 when compared with ground-based GPP while an RMSE of 8.010 gC m(-2 d(-1 and an R of 0.682 can be achieved for MODIS GPP, the estimated NPP values were also well within the range of previous literature, which proved the reliability of

  5. The sergestid shrimp Lucifer in the 1970 CICAR plankton samples taken by H.M.S. “Luymes”, with notes on the Amazon river as nutrient source

    NARCIS (Netherlands)

    Troost, Dick G.

    1975-01-01

    In accordance with previous works, L. faxoni was found to be abundant and L. typus scarce in the changing environment of the coastal waters off northern South America. High numbers of L. faxoni were present in two types of water, viz. highly saline coastal waters with high primary productivity due

  6. Proximate versus ultimate limiting nutrients in the Mississippi River Plume and Implications for Hypoxia Reductions through Nutrient Management

    Science.gov (United States)

    Fennel, Katja; Laurent, Arnaud

    2016-04-01

    A large hypoxic area (15,000 km2 on average) forms every summer over the Texas-Louisiana shelf in the northern Gulf of Mexico due to decay of organic matter that is primarily derived from nutrient inputs from the Mississippi/Atchafalaya River System. Efforts are underway to reduce the extent of hypoxic conditions through nutrient management in the watershed; for example, an interagency Hypoxia Task Force is developing Action Plans with input from various stakeholders that set out targets for hypoxia reduction. An open question is how far nutrient loads would have to be decreased in order to produce the desired reductions in hypoxia and when these would be measurable given significant natural variability. We have simulated a large number of multi-year nutrient load reduction scenarios with a regional biogeochemical model for the region. The model is based on the Regional Ocean Modeling System (ROMS), explicitly includes nitrogen (N) and phosphorus (P) species as inorganic nutrients, and has been shown to realistically reproduce the key processes responsible for hypoxia generation. We have quantified the effects of differential reductions in river N and P loads on hypoxic extent. An assessment of the effects of N versus P reductions is important because, thus far, nutrient management efforts have focused on N, yet P is known to limit primary production in spring and early summer. A debate is ongoing as to whether targets for P reductions should be set and whether nutrient reduction efforts should focus solely on P, which results primarily from urban and industrial point sources and is uncoupled from agricultural fertilizer application. Our results strongly indicate that N is the 'ultimate' limiting nutrient to primary production determining the areal extent and duration of hypoxic conditions in a cumulative sense, while P is temporarily limiting in spring. Although reductions in river P load would decrease hypoxic extent in early summer, they would have a much

  7. Proximate and Ultimate Limiting Nutrients in the Mississippi River Plume: Implications for Hypoxia Reduction Through Nutrient Management

    Science.gov (United States)

    Fennel, K.; Laurent, A.

    2016-02-01

    A large hypoxic area (15,000 km2 on average) forms every summer over the Texas-Louisiana shelf in the northern Gulf of Mexico due to decay of organic matter that is primarily derived from nutrient inputs from the Mississippi/Atchafalaya River System. Efforts are underway to reduce the extent of hypoxic conditions through nutrient management in the watershed; for example, an interagency Hypoxia Task Force is developing Action Plans with input from various stakeholders that set out targets for hypoxia reduction. An open question is by how much nutrient loads would have to be decreased in order to produce the desired reductions in hypoxia and when these would be measurable over natural variability. We have performed a large number of multi-year nutrient load reduction scenarios with a regional biogeochemical model for the region. The model is based on the Regional Ocean Modeling System (ROMS), explicitly includes nitrogen (N) and phosphorus (P) species as inorganic nutrients, and has been shown to realistically reproduce the key processes responsible for hypoxia generation. We have quantified the effects of differential reductions in river N and P loads on hypoxic extent. An assessment of the effects of N versus P reductions is important because, thus far, nutrient management efforts have focused on N, yet P is known to limit primary production in spring and early summer. A debate is ongoing as to whether targets for P reductions should be set and whether nutrient reduction efforts should focus solely on P, which results primarily from urban and industrial point sources and is uncoupled from agricultural fertilizer application. Our results strongly indicate that N is the `ultimate' limiting nutrient to primary production determining the areal extent and duration of hypoxic conditions in a cumulative sense, while P is temporarily limiting in spring. Although reductions in river P load would decrease hypoxic extent in early summer, they would have a much smaller effect

  8. MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS

    Science.gov (United States)

    Understanding the consequences of the declining global cover of mangroves due to anthropogenic disturbance necessitates consideration of how mangrove-derived nutrients contribute to threatened coral reef systems. We sampled potential sources of organic matter and a suite of sessi...

  9. Relative importance of H2 and H2S as energy sources for primary production in geothermal springs.

    Science.gov (United States)

    D'Imperio, Seth; Lehr, Corinne R; Oduro, Harry; Druschel, Greg; Kühl, Michael; McDermott, Timothy R

    2008-09-01

    Geothermal waters contain numerous potential electron donors capable of supporting chemolithotrophy-based primary production. Thermodynamic predictions of energy yields for specific electron donor and acceptor pairs in such systems are available, although direct assessments of these predictions are rare. This study assessed the relative importance of dissolved H(2) and H(2)S as energy sources for the support of chemolithotrophic metabolism in an acidic geothermal spring in Yellowstone National Park. H(2)S and H(2) concentration gradients were observed in the outflow channel, and vertical H(2)S and O(2) gradients were evident within the microbial mat. H(2)S levels and microbial consumption rates were approximately three orders of magnitude greater than those of H(2). Hydrogenobaculum-like organisms dominated the bacterial component of the microbial community, and isolates representing three distinct 16S rRNA gene phylotypes (phylotype = 100% identity) were isolated and characterized. Within a phylotype, O(2) requirements varied, as did energy source utilization: some isolates could grow only with H(2)S, some only with H(2), while others could utilize either as an energy source. These metabolic phenotypes were consistent with in situ geochemical conditions measured using aqueous chemical analysis and in-field measurements made by using gas chromatography and microelectrodes. Pure-culture experiments with an isolate that could utilize H(2)S and H(2) and that represented the dominant phylotype (70% of the PCR clones) showed that H(2)S and H(2) were used simultaneously, without evidence of induction or catabolite repression, and at relative rate differences comparable to those measured in ex situ field assays. Under in situ-relevant concentrations, growth of this isolate with H(2)S was better than that with H(2). The major conclusions drawn from this study are that phylogeny may not necessarily be reliable for predicting physiology and that H(2)S can dominate over H(2

  10. Comportamento ingestivo de cordeiros e digestibilidade dos nutrientes de dietas contendo alta proporção de concentrado e diferentes fontes de fibra em detergente neutro Lamb feeding behavior and nutrient digestibility of high concentrate diets with different neutral detergent fiber sources

    Directory of Open Access Journals (Sweden)

    Clayton Quirino Mendes

    2010-03-01

    Full Text Available Dois experimentos foram realizados para avaliar os efeitos da substituição da fibra em detergente neutro (FDN do bagaço de cana-de-açúcar in natura pela FDN da casca de soja em dietas com alta proporção de concentrado sobre o comportamento ingestivo de cordeiros e a digestibilidade dos nutrientes. No primeiro experimento, 60 cordeiros com 16,4 ± 0,3 kg de peso corporal e idade inicial de 67 ± 2 dias foram distribuídos em delineamento de blocos completos casualizados, em esquema fatorial 2 × 2 + 1, composto de duas fontes de FDN (bagaço de cana in natura ou casca de soja, dois teores de FDN (14 ou 18% e uma dieta controle contendo 100% de concentrado. No segundo experimento, cinco cordeiros foram distribuídos em quadrado latino 5 × 5 e submetidos às mesmas dietas do experimento 1. As dietas contendo as fontes de fibra promoveram maior consumo de matéria seca, matéria orgânica e FDN e maior tempo de ingestão, ruminação e mastigação (minutos/dia em comparação à dieta contendo 100% de concentrado. As dietas contendo o bagaço de canade-açúcar in natura proporcionaram maior atividade de ruminação que aquelas com casca de soja. Entretanto, a utilização da casca de soja proporcionou menor atividade de mastigação e maior digestibilidade dos nutrientes em relação ao bagaço de cana-de-açúcar in natura. A casca de soja pode ser utilizada como única fonte adicional de FDN em dietas contendo alto teor de concentrado para cordeiros.Two experiments were performed to determine the effects of replacing the neutral detergent fiber from sugarcane bagasse with soybean hulls neutral detergent fiber in high concentrate diets on lamb feeding behavior and apparent nutrient digestibility. In the first experiment, 60 ram lambs with 16.4 ± 0.3 kg body weight and 67 ± 2 days old were allotted to a complete randomized block design as a 2 × 2 + 1 factorial arrangement of treatments, consisting of two neutral detergent fiber sources

  11. Hydrothermal carbonization of food waste for nutrient recovery and reuse.

    Science.gov (United States)

    Idowu, Ifeolu; Li, Liang; Flora, Joseph R V; Pellechia, Perry J; Darko, Samuel A; Ro, Kyoung S; Berge, Nicole D

    2017-11-01

    Food waste represents a rather large and currently underutilized source of potentially available and reusable nutrients. Laboratory-scale experiments evaluating the hydrothermal carbonization of food wastes collected from restaurants were conducted to understand how changes in feedstock composition and carbonization process conditions influence primary and secondary nutrient fate. Results from this work indicate that at all evaluated reaction times and temperatures, the majority of nitrogen, calcium, and magnesium remain integrated within the solid-phase, while the majority of potassium and sodium reside in the liquid-phase. The fate of phosphorus is dependent on reaction times and temperatures, with solid-phase integration increasing with higher reaction temperature and longer time. A series of leaching experiments to determine potential solid-phase nutrient availability were also conducted and indicate that, at least in the short term, nitrogen release from the solids is small, while almost all of the phosphorus present in the solids produced from carbonizing at 225 and 250°C is released. At a reaction temperature of 275°C, smaller fractions of the solid-phase total phosphorus are released as reaction times increase, likely due to increased solids incorporation. Using these data, it is estimated that up to 0.96% and 2.30% of nitrogen and phosphorus-based fertilizers, respectively, in the US can be replaced by the nutrients integrated within hydrochar and liquid-phases generated from the carbonization of currently landfilled food wastes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. High Precision Positioning at Field Camp: Using GNSS as the primary data source to answer geologic questions

    Science.gov (United States)

    Crosby, B. T.; Lauer, I. H.; Pratt-Sitaula, B.

    2017-12-01

    Thanks to the availability and accessibility of GPS/GNSS enabled consumer grade positioning devices, GNSS are nearly ubiquitous in both geologic field research and education. Though the devices offer sufficient precision to geotag images, digital field book entries or measurements, positions themselves are not precise enough to accomplish independent geodetic analysis. As a consequence, most students learn about GNSS at a tool that aids other forms of geologic data acquisition rather serving as the primary source itself. To resolve this, we developed and tested a three-unit teaching module within the GETSI - SERC curriculum framework that reinforces high precision positioning as a primary source of geologic data. Units focus on three core topics: GNSS Fundamentals, Kinematic GNSS and Static GNSS Methods. Module goals enable students to (a) design and conduct a GNSS survey to answer a geologic question, (b) justify why their GNSS technique is appropriate to their question and (c) to articulate how answering their question benefits society. Skill building is via quantitative and qualitative analysis, concept sketches, and both field and office based data acquisition and interrogation. Exercises are site-independent and include example datasets for those unable to travel. In the summer of 2017, we tested the module with 20 undergraduate students over two days at the ISU field geology course. Located in the Lost River Range of Idaho, positioned among active normal faults, we not only explored the use of static GNSS data for active tectonics but visited a station in person. For a summative assessment, we focused on kinematic GNSS, using RTK rovers to reoccupy leveling monuments spanning the active Lost River fault that ruptured in 1983 (M 7.0). The data collected by our class quantified aseismic deformation occurring in the 30+ years since that event. Displacements were significantly larger than the instrumental uncertainty, confirming that RTK was an appropriate tool

  13. Exportação de nutrientes pelos frutos de melancia em função de épocas de cultivo, fontes e doses de potássio Nutrients recruitment of watermelon fruits in relation to seasons, potassium sources and doses

    Directory of Open Access Journals (Sweden)

    Leilson C. Grangeiro

    2004-12-01

    Full Text Available Foram conduzidos dois experimentos em propriedades rurais, localizadas próxima a cidade de Borborema (SP, de outubro a dezembro/2001 e de fevereiro a abril/2002, com o objetivo de determinar as quantidades exportadas de nutrientes pelos frutos de melancia, em função de fontes e doses de potássio, em duas épocas de cultivo. O delineamento experimental utilizado foi o de blocos casualizados completos, em esquema fatorial 3x4, com três repetições, sendo avaliados as fontes: cloreto, nitrato e sulfato de potássio e as doses: 50; 100; 200 e 300 kg ha-1 de K2O. Com exceção do Mg, as maiores exportações de nutrientes pelos frutos foram obtidas no cultivo de outubro a dezembro. A massa seca e as exportações de N, P, K, e Ca aumentaram de forma quadrática com as doses de potássio. A aplicação KCl aumentou respectivamente, de forma quadrática e linear, as exportações de S e Cl pelos frutos de melancia.Two field experiments were conducted in Borborema, São Paulo State, Brazil, from October to December 2001 and February to April 2002, to evaluate the nutrients recruitment of watermelon fruits, Tide hybrid, as a result of potassium sources and doses. The experimental design was a randomized complete block, with three replications, in 3x4 factorial scheme, the sources being evaluated: potassium chloride, nitrate and sulphate and doses of 50; 100; 200 and 300 kg ha-1 K2O. Greater recruitment of N, P, K, Ca, S and Cl by watermelon fruits was obtained in the first trial, while the recruitment of Mg was observed in the second trial. The dry mass and recruitment of N, P, K, and Ca increased with potassium doses. S and Cl of the watermelon fruits increased with the increase of KCl doses in a quadratic and linear form, respectively.

  14. Impact of biomass burning on nutrient deposition to the global ocean

    Science.gov (United States)

    Kanakidou, Maria; Myriokefalitakis, Stelios; Daskalakis, Nikos; Mihalopoulos, Nikolaos; Nenes, Athanasios

    2017-04-01

    Atmospheric deposition of trace constituents, both of natural and anthropogenic origin, can act as a nutrient source into the open ocean and affect marine ecosystem functioning and subsequently the exchange of CO2 between the atmosphere and the global ocean. Dust is known as a major source of nutrients (Fe and P) into the atmosphere, but only a fraction of these nutrients is released in soluble form that can be assimilated by the ecosystems. Dust is also known to enhance N deposition by interacting with anthropogenic pollutants and neutralisation of part of the acidity of the atmosphere by crustal alkaline species. These nutrients have also primary anthropogenic sources including combustion emissions. The global atmospheric N [1], Fe [2] and P [3] cycles have been parameterized in the global 3-D chemical transport model TM4-ECPL, accounting for inorganic and organic forms of these nutrients, for all natural and anthropogenic sources of these nutrients including biomass burning, as well as for the link between the soluble forms of Fe and P atmospheric deposition and atmospheric acidity. The impact of atmospheric acidity on nutrient solubility has been parameterised based on experimental findings and the model results have been evaluated by extensive comparison with available observations. In the present study we isolate the significant impact of biomass burning emissions on these nutrients deposition by comparing global simulations that consider or neglect biomass burning emissions. The investigated impact integrates changes in the emissions of the nutrients as well as in atmospheric oxidants and acidity and thus in atmospheric processing and secondary sources of these nutrients. The results are presented and thoroughly discussed. References [1] Kanakidou M, S. Myriokefalitakis, N. Daskalakis, G. Fanourgakis, A. Nenes, A. Baker, K. Tsigaridis, N. Mihalopoulos, Past, Present and Future Atmospheric Nitrogen Deposition, Journal of the Atmospheric Sciences (JAS-D-15

  15. Study on Net Primary Productivity over Complicated Mountainous Area based on Multi-Source Remote Sensing Data

    Science.gov (United States)

    Guan, X.; Shen, H.; Li, X.; Gan, W.

    2017-12-01

    Mountainous area hosts approximately a quarter of the global land surface, with complex climate and ecosystem conditions. More knowledge about mountainous ecosystem could highly advance our understanding of the global carbon cycle and climate change. Net Primary Productivity (NPP), the biomass increment of plants, is a widely used ecological indicator that can be obtained by remote sensing methods. However, limited by the defective characteristic of sensors, which cannot be long-term with enough spatial details synchronously, the mountainous NPP was far from being understood. In this study, a multi-sensor fusion framework was applied to synthesize a 1-km NPP series from 1982 to 2014 in mountainous southwest China, where elevation ranged from 76m to 6740m. The validation with field-measurements proved this framework greatly improved the accuracy of NPP (r=0.79, prun-off. What is more, it was indicated that the NPP variation showed three distinct stages at the year break-point of 1992 and 2002 over the region. The NPP in low-elevation area varied almost triple more drastic than the high-elevation area for all the three stages, due to the much greater change rate of precipitation. In summary, this study innovatively conducted a long-term and accurate NPP study on the not understood mountainous ecosystem with multi-source data, the framework and conclusions will be beneficial for the further cognition of global climate change.

  16. Attraction of Chagas disease vectors (Triatominae) to artificial light sources in the canopy of primary Amazon rainforest.

    Science.gov (United States)

    Castro, Marcelo C M; Barrett, Toby V; Santos, Walter S; Abad-Franch, Fernando; Rafael, José A

    2010-12-01

    Adult triatomines occasionally fly into artificially lit premises in Amazonia. This can result in Trypanosoma cruzi transmission to humans either by direct contact or via foodstuff contamination, but the frequency of such behaviour has not been quantified. To address this issue, a light-trap was set 45 m above ground in primary rainforest near Manaus, state of Amazonas, Brazil and operated monthly for three consecutive nights over the course of one year (432 trap-hours). The most commonly caught reduviids were triatomines, including 38 Panstrongylus geniculatus, nine Panstrongylus lignarius, three Panstrongylus rufotuberculatus, five Rhodnius robustus, two Rhodnius pictipes, one Rhodnius amazonicus and 17 Eratyrus mucronatus. Males were collected more frequently than females. The only month without any catches was May. Attraction of most of the known local T. cruzi vectors to artificial light sources is common and year-round in the Amazon rainforest, implying that they may often invade premises built near forest edges and thus become involved in disease transmission. Consequently, effective Chagas disease prevention in Amazonia will require integrating entomological surveillance with the currently used epidemiological surveillance.

  17. Attraction of Chagas disease vectors (Triatominae to artificial light sources in the canopy of primary Amazon rainforest

    Directory of Open Access Journals (Sweden)

    Marcelo CM Castro

    2010-12-01

    Full Text Available Adult triatomines occasionally fly into artificially lit premises in Amazonia. This can result in Trypanosoma cruzi transmission to humans either by direct contact or via foodstuff contamination, but the frequency of such behaviour has not been quantified. To address this issue, a light-trap was set 45 m above ground in primary rainforest near Manaus, state of Amazonas, Brazil and operated monthly for three consecutive nights over the course of one year (432 trap-hours. The most commonly caught reduviids were triatomines, including 38 Panstrongylus geniculatus, nine Panstrongylus lignarius, three Panstrongylus rufotuberculatus, five Rhodnius robustus, two Rhodnius pictipes, one Rhodnius amazonicus and 17 Eratyrus mucronatus. Males were collected more frequently than females. The only month without any catches was May. Attraction of most of the known local T. cruzi vectors to artificial light sources is common and year-round in the Amazon rainforest, implying that they may often invade premises built near forest edges and thus become involved in disease transmission. Consequently, effective Chagas disease prevention in Amazonia will require integrating entomological surveillance with the currently used epidemiological surveillance.

  18. A comparison of nutrient density scores for 100% fruit juices.

    Science.gov (United States)

    Rampersaud, G C

    2007-05-01

    The 2005 Dietary Guidelines for Americans recommend that consumers choose a variety of nutrient-dense foods. Nutrient density is usually defined as the quantity of nutrients per calorie. Food and nutrition professionals should be aware of the concept of nutrient density, how it might be quantified, and its potential application in food labeling and dietary guidance. This article presents the concept of a nutrient density score and compares nutrient density scores for various 100% fruit juices. One hundred percent fruit juices are popular beverages in the United States, and although they can provide concentrated sources of a variety of nutrients, they can differ considerably in their nutrient profiles. Six methodologies were used to quantify nutrient density and 7 100% fruit juices were included in the analysis: apple, grape, pink grapefruit, white grapefruit, orange, pineapple, and prune. Food composition data were obtained from the USDA National Nutrient Database for Standard Reference, Release 18. Application of the methods resulted in nutrient density scores with a range of values and magnitudes. The relative scores indicated that citrus juices, particularly pink grapefruit and orange juice, were more nutrient dense compared to the other nonfortified 100% juices included in the analysis. Although the methods differed, the relative ranking of the juices based on nutrient density score was similar for each method. Issues to be addressed regarding the development and application of a nutrient density score include those related to food fortification, nutrient bioavailability, and consumer education and behavior.

  19. Water Quality Protection from Nutrient Pollution: Case ...

    Science.gov (United States)

    Water bodies and coastal areas around the world are threatened by increases in upstream sediment and nutrient loads, which influence drinking water sources, aquatic species, and other ecologic functions and services of streams, lakes, and coastal water bodies. For example, increased nutrient fluxes from the Mississippi River Basin have been linked to increased occurrences of seasonal hypoxia in northern Gulf of Mexico. Lake Erie is another example where in the summer of 2014 nutrients, nutrients, particularly phosphorus, washed from fertilized farms, cattle feedlots, and leaky septic systems; caused a severe algae bloom, much of it poisonous; and resulted in the loss of drinking water for a half-million residents. Our current management strategies for point and non-point source nutrient loadings need to be improved to protect and meet the expected increased future demands of water for consumption, recreation, and ecological integrity. This presentation introduces management practices being implemented and their effectiveness in reducing nutrient loss from agricultural fields, a case analysis of nutrient pollution of the Grand Lake St. Marys and possible remedies, and ongoing work on watershed modeling to improve our understanding on nutrient loss and water quality. Presented at the 3rd International Conference on Water Resource and Environment.

  20. Soluble organic nutrient fluxes

    Science.gov (United States)

    Robert G. Qualls; Bruce L. Haines; Wayne Swank

    2014-01-01

    Our objectives in this study were (i) compare fluxes of the dissolved organic nutrients dissolved organic carbon (DOC), DON, and dissolved organic phosphorus (DOP) in a clearcut area and an adjacent mature reference area. (ii) determine whether concentrations of dissolved organic nutrients or inorganic nutrients were greater in clearcut areas than in reference areas,...

  1. Evaluation of indigenous fresh water microalga Scenedesmus obtusus for feed and fuel applications: Effect of carbon dioxide, light and nutrient sources on growth and biochemical characteristics.

    Science.gov (United States)

    Sarat Chandra, T; Deepak, R S; Maneesh Kumar, M; Mukherji, S; Chauhan, V S; Sarada, R; Mudliar, S N

    2016-05-01

    Scenedesmus obtusus, a freshwater microalga, was evaluated for its growth and biochemical characteristics under various culture conditions. S. obtusus was tolerant at all tested CO2 concentrations up to 20%. Among the different nitrogen sources, urea showed enhanced biomass productivities up to 2-fold compared to control, where the nitrogen source was sodium nitrate. Light intensity and photoperiod had a significant effect on growth rate and biomass productivity. The growth rate was observed maximum under continuous light exposure at the light intensities, 30μmolm(-2)sec(-1) and 60μmolm(-2)sec(-1) The species was able to tolerate the salinity levels up to 25mM NaCl, where, the increase in the concentration of NaCl suppressed the growth. Ammonium acetate and glycine showed better growth rate and biomass productivity indicating mixotrophic ability of S. obtusus. Supplementation of acetate and bicarbonate significantly enhanced the biomass productivity. Biodiesel properties of S. obtusus cultivated at various culture conditions were estimated. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Nutrient Budgets Calculated in Floodwaters Using a Whole-Ecosystem Experimental Manipulation

    Science.gov (United States)

    Talbot, C. J.; Paterson, M. J.; Xenopoulos, M. A.

    2017-12-01

    Flooding provides pathways for nutrients to move into surface waters and alter nutrient concentrations, therefore influencing downstream ecosystems and increasing events of eutrophication. Nutrient enrichment will likely affect water quality, primary production, and overall ecosystem function. Quantifying nutrient movement post-flood will help evaluate the risks or advantages that flooding will have on ecosystem processes. Here we constructed nutrient budgets using data collected as part of the Flooded Upland Dynamics Experiment (FLUDEX) at the Experimental Lakes Area (ELA) in northwestern Ontario. Three experimental reservoirs with varying amounts of stored carbon were created by flooding forested land from May through September annually from 1999 to 2003. Organic matter became a significant source of nutrients under flooded conditions and elevated reservoir total nitrogen (TN) and total phosphorus (TP) concentrations within one week of flooding. The highest TN (2.6 mg L-1) and TP (579 µg L-1) concentrations throughout the entire flooding experiment occurred in the medium carbon reservoir within the first two weeks of flooding in 1999. TN and TP fluxes were positive in all years of flooding. TP fluxes decreased after each flooding season therefore, TP production may be less problematic in floodplains subject to frequent repeated flooding. However, TN fluxes remained large even after repeated flooding. Therefore, flooding, whether naturally occurring or from anthropogenic flow alteration, may be responsible for producing significant amounts of nitrogen and phosphorus in aquatic ecosystems.

  3. Effect of post-ethanol extraction sorghum silage as a forage source in growing and finishing diets on steer performance, carcass characteristics, and nutrient digestibility.

    Science.gov (United States)

    Blank, C P; Loy, D D; Hansen, S L

    2017-07-01

    Two experiments evaluated the use of post-ethanol extraction sorghum silage as an alternative forage source in feedlot diets. Seventy-two crossbred steers (397 kg [SD 23]) were used to evaluate growth and carcass characteristics. Steers were blocked by BW into pens of 6 steers and randomly assigned to growing diets containing 40% (DM basis) sorghum silage (SS; 57.6% NDF) or grass hay (CON; 63.3% NDF) for 56 d ( = 6 pens per treatment). Within each treatment, steers transitioned to dry-rolled corn-based finishing diets (fed for 56 d) containing 6% effective NDF contributed by the forage source, resulting in forage inclusions of 16% for SS and 13.1% for CON, where forage replaced corn. A subsample of steers ( = 12 per treatment) housed in pens equipped with GrowSafe bunks were used for determination of growing phase diet total tract digestibility. From d 28 to 42, steers received titanium dioxide at approximately 10 g∙steer∙d, and fecal samples were collected on d 41 and 42. Fecal and total mixed ration samples were dried and ground for analysis of DM, OM, NDF, ADF, CP, ether extract (EE), and starch. Data were analyzed with the MIXED procedure of SAS, with fixed effects of treatment and block for performance and carcass data or treatment for digestibility data; significance was determined at ≤ 0.05 and tendencies at ≤ 0.10. Growing phase DMI and ADG did not differ due to treatment ( ≥ 0.19); however, SS-fed steers had improved G:F compared with CON-fed steers ( = 0.04). Finishing period ADG and G:F did not differ ( ≥ 0.15) between treatments, despite SS-fed steers having lesser ( = 0.008) DMI than CON-fed steers. No differences in DMI, ADG, or G:F over the whole trial were noted between treatments ( ≥ 0.12) nor were any carcass traits affected ( ≥ 0.23). During the digestibility assessment period, DMI was less ( = 0.003) in SS-fed steers. Growing phase total tract apparent digestibility of DM and starch did not differ ( ≥ 0.19) due to treatment

  4. Reply by the Federal Government to a question concerning new primary energy sources raised in the Bundestag

    Energy Technology Data Exchange (ETDEWEB)

    Matthoefer, H [Bundesministerium fuer Forschung und Technologie, Bonn (F.R. Germany)

    1976-06-01

    A question raised in the Bundestag concerning new primary energy sources was answered by the Federal Minister for Science and Technology in his letter dated June 2, 1976; the letter called attention to the Federal Government's energy program of September 1973 which, instead of promoting research almost exclusively on the nuclear sector as used to be the case, aims at a purposeful and comprehensive promotion by the state of non-nuclear energy research as well in the FRG. Solar energy seems to have the best chance in the FRG of being utilized in an industrial way, applying low-temperature collectors to recover heat for heating and hot water preparation; 28 million DM have been invested so far. Despite the fact that the technical potential of wind power in the FRG would cover almost 75% of the present electricity demand, only plants with a small kW range are being developed at the moment as the question of energy storage is still open; 0.3 million DM have been granted so far. The utilization of geothermal power can only be of interest for the FRG on the basis of the hot-dry-rock method; drilling work is carried out in the Eifel district investigating geothermal gradients: 1.25 million DM have been granted so far. In 1976 the projects mentioned above have been allotted research funds amounting to 20 million DM. Energy from running/tidal waters is utilized in the FRG to 90% so far, but this only accounts for 6.7% of the gross electricity generation. Therefore, its importance for the energy supply of the FRG will decrease when the energy demand increases.

  5. [Internet as an information source for health in primary care patients and its influence on the physician-patient relationship].

    Science.gov (United States)

    Marin-Torres, Viviana; Valverde Aliaga, Justo; Sánchez Miró, Ignacio; Sáenz Del Castillo Vicente, María Isabel; Polentinos-Castro, Elena; Garrido Barral, Araceli

    2013-01-01

    To describe the use of the Internet by primary care patients to seek health related information, understand how they are influenced by this information, and evaluate its impact on the doctor-patient relationship. Cross sectional study, through self-administered survey. One urban health center in Madrid. A total of 323 questionnaires were collected from patients between 14 and 75 years old who attended a physician's office for any reason, excluding illiterate patients and those with neurological or psychiatric problems preventing them from completing the survey. Internet usage, ability of the internet to clarify doubts regarding health issues, patient lifestyle changes, socio-demographic variables, and physician's receptivity to the use of internet by patients. 61% (CI95%: 56%-67%) of patients used the Internet as a source of health information: Internet queries were able to address health doubts in 92.4% of users, 53.5% reported that the Internet changed their thinking about their health in at least one instance, 30% made behavioral changes (of which 60.1% discussed these changes with their physician), 44.3% had more questions at the physician's office, and 80.8% believe that the doctor would be willing to talk about the information found on the internet. Using the Internet to find information about health is very common, with positive influence on physician-patient relationship. This may be useful for achieving behavioral changes in patients and can be used as a tool in medical practice. Copyright © 2012 Elsevier España, S.L. All rights reserved.

  6. Analysis of the primary source term for meltdown accidents using MELCOR 1.8.2; Analyse des primaeren Quellterms bei Kernschmelzunfaellen mit MELCOR 1.8.2

    Energy Technology Data Exchange (ETDEWEB)

    Schmuck, P.

    1995-08-01

    The MELCOR code describing accident phenomena in the core and primary systems was used for source term calculations and - in the context of the MELCOR Cooperative Assessment Programme - for studying two-phase flows through components such as valves and chokes. Results of the latter studies in comparison to experiments gave hints for an improved calculation of momentum transfer between the phases. (orig.)

  7. Loads of suspended sediment and nutrients from local nonpoint sources to the tidal Potomac River and Estuary, Maryland and Virginia, 1979-81 water years

    Science.gov (United States)

    Hickman, R. Edward

    1987-01-01

    Loads of suspended sediment, phosphorus, nitrogen, biochemical oxygen demand, and dissolved silica discharged to the tidal Potomac River and Estuary during the !979-81 water years from three local nonpoint sources have been calculated. The loads in rain falling directly upon the tidal water surface and from overflows of the combined sewer system of the District of Columbia were determined from available information. Loads of materials in the streamflow from local watersheds draining directly to the tidal Potomac River and Estuary downstream from Chain Bridge in Washington, D.C., were calculated from samples of streamflow leaving five monitored watersheds. Average annual yields of substances leaving three urban watersheds (Rock Creek and the Northwest and Northeast Branches of the Anacostia River) and the rural Saint Clements Creek watershed were calculated either by developing relationships between concentration and streamflow or by using the mean of measured concentrations. Yields calculated for the 1979-81 water years are up to 2.3 times period-of-record yields because of greater than average streamflow and stormflow during this 3-year period. Period-of-record yields of suspended sediment from the three urban watersheds and the Saint Clements Creek watershed do not agree with yields reported by other studies. The yields from the urban watersheds are 17 to 51 percent of yields calculated using sediment-concentration data collected during the 1960-62 water years. Previous studies suggest that this decrease is at least partly due to the imposition of effective sediment controls at construction sites and to the construction of two multipurpose reservoirs. The yield calculated for the rural Saint Clements Creek watershed is at least twice the yields calculated for other rural watersheds, a result that may be due to most of the samples of this stream being taken during the summer of the 1981 water year, a very dry period. Loads discharged from all local tributary

  8. Eddy energy sources and flux in the Red Sea

    KAUST Repository

    Zhan, Peng; Subramanian, Aneesh C.; Kartadikaria, Aditya R.; Hoteit, Ibrahim

    2015-01-01

    the basin and by pumping the nutrient-enriched subsurface water to sustain the primary production. Previous observations and modeling work suggest that the Red Sea is rich of eddy activities. In this study, the eddy energy sources and sinks have been studied

  9. Investigation of primary cooling water chemistry following the partial meltdown of Pu-Be neutron source in Tehran Research Reactor Core (TRR)

    Energy Technology Data Exchange (ETDEWEB)

    Aghoyeh, Reza Gholizadeh [School of Research and Development of Nuclear Reactors and Accelerators, Nuclear Science and Technology Research Institute (NSTRI), Atomic Energy Organization of Iran (AEOI), P.O. Box: 14155-1339, Tehran (Iran, Islamic Republic of); Khalafi, Hossein, E-mail: hkhalafi@aeoi.org.i [School of Research and Development of Nuclear Reactors and Accelerators, Nuclear Science and Technology Research Institute (NSTRI), Atomic Energy Organization of Iran (AEOI), P.O. Box: 14155-1339, Tehran (Iran, Islamic Republic of)

    2011-03-15

    Research highlights: Effect of Pu-Be neutron source meltdown in core on reactor water chemistry. Water chemistry of primary cooling before, during and after of above incident was compared. Training importance. Management of nuclear incident and accident. - Abstract: Effect of Pu-Be neutron source meltdown in core on reactor water chemistry was main aim of this study. Leaving the neutron source in the core after reactor power exceeds a few hundred Watts was the main reason for its partial meltdown. Water chemistry of primary cooling before, during and after of above incident was compared. Activity of some radio-nuclides such as Ba-140, La-140, I-131, I-132, Te-132 and Xe-135 increased. Other radio-nuclides such as Nd-147, Xe-133, Sr-91, I-133 and I-135 are also detected which were not existed before this incident.

  10. Use of by-products rich in carbon and nitrogen as a nutrient source to produce Bacillus thuringiensis (Berliner)-based bio pesticide

    International Nuclear Information System (INIS)

    Valicente, Fernando H.; Mourao, Andre H.C.

    2008-01-01

    The amount and sources of carbon and nitrogen used to produce Bacillus thuringiensis (Berliner)-based biopesticide may influence the quality of the fi nal product. The objective of this research was to test different levels of carbon and nitrogen: medium 1 - 1.5% maize glucose + 0.5% soy fl our, medium 2 - 3.0% maize glucose + 1.0% soy flour, medium 3 - 1.0% maize glucose + 3.0% soy fl our and medium 4 - Luria Bertani (LB) + salts (FeSO 4 , ZnSO 4 , MnSO 4 , MgSO 4 ). The seed culture was produced in LB medium plus salt, under agitation (200 rpm) for 18h at 30 deg C. The strain 344 of Bt was used (B. thuringiensis var tolworthi - belonging to the EMBRAPA's Bt Bank). The pH was measured at regular intervals, and After culturing for 96h, the pH of the four tested media was basified (6.91 and 8.15), the number of spores yielded 4.39 x 10 9 spores/ml in medium 3, where the amount of protein is high. The dry biomass weight accumulated in media 3 was 39.3 g/l. Mortality of 2-day-old larvae Spodoptera frugiperda (J.E. Smith) was 100% when using Bt produced in media 3 and 4. CL 50 for medium 3 was 8.4 x 10 6 spores/ml. All tested media were satisfactory to Bt growth, and medium 3 was the most promising to be used on a large scale Bt-based biopesticide production. (author)

  11. Use of by-products rich in carbon and nitrogen as a nutrient source to produce Bacillus thuringiensis (Berliner)-based bio pesticide

    Energy Technology Data Exchange (ETDEWEB)

    Valicente, Fernando H. [EMBRAPA Milho e Sorgo, Sete Lagoas, MG (Brazil)]. E-mail: valicent@cnpms.embrapa.br; Mourao, Andre H.C. [Curso de Meio Ambiente, Sete Lagoas, MG (Brazil)

    2008-11-15

    The amount and sources of carbon and nitrogen used to produce Bacillus thuringiensis (Berliner)-based biopesticide may influence the quality of the fi nal product. The objective of this research was to test different levels of carbon and nitrogen: medium 1 - 1.5% maize glucose + 0.5% soy fl our, medium 2 - 3.0% maize glucose + 1.0% soy flour, medium 3 - 1.0% maize glucose + 3.0% soy fl our and medium 4 - Luria Bertani (LB) + salts (FeSO{sub 4}, ZnSO{sub 4}, MnSO{sub 4}, MgSO{sub 4}). The seed culture was produced in LB medium plus salt, under agitation (200 rpm) for 18h at 30 deg C. The strain 344 of Bt was used (B. thuringiensis var tolworthi - belonging to the EMBRAPA's Bt Bank). The pH was measured at regular intervals, and After culturing for 96h, the pH of the four tested media was basified (6.91 and 8.15), the number of spores yielded 4.39 x 10{sup 9} spores/ml in medium 3, where the amount of protein is high. The dry biomass weight accumulated in media 3 was 39.3 g/l. Mortality of 2-day-old larvae Spodoptera frugiperda (J.E. Smith) was 100% when using Bt produced in media 3 and 4. CL{sub 50} for medium 3 was 8.4 x 10{sup 6} spores/ml. All tested media were satisfactory to Bt growth, and medium 3 was the most promising to be used on a large scale Bt-based biopesticide production. (author)

  12. Nutrients for the aging eye

    Directory of Open Access Journals (Sweden)

    Rasmussen HM

    2013-06-01

    Full Text Available Helen M Rasmussen,1 Elizabeth J Johnson2 1Educational Studies, Lesley University, Cambridge, MA, USA; 2Carotenoid and Health Laboratory, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA Abstract: The incidence of age-related eye diseases is expected to rise with the aging of the population. Oxidation and inflammation are implicated in the etiology of these diseases. There is evidence that dietary antioxidants and anti-inflammatories may provide benefit in decreasing the risk of age-related eye disease. Nutrients of interest are vitamins C and E, β-carotene, zinc, lutein, zeaxanthin, and the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid. While a recent survey finds that among the baby boomers (45–65 years old, vision is the most important of the five senses, well over half of those surveyed were not aware of the important nutrients that play a key role in eye health. This is evident from a national survey that finds that intake of these key nutrients from dietary sources is below the recommendations or guidelines. Therefore, it is important to educate this population and to create an awareness of the nutrients and foods of particular interest in the prevention of age-related eye disease. Keywords: nutrition, aging, eye health

  13. Did the Vikings Really Have Helmets with Horns? Sources and Narrative Content in Swedish Upper Primary School History Teaching

    Science.gov (United States)

    Stolare, Martin

    2017-01-01

    The topic of this article is history education in upper primary school. Traditionally, the history subject has had a narrative orientation at this school level in Sweden, but it is also pattern that is discernible internationally. The recent Swedish upper primary school syllabus places more emphasis on the procedural aspects of the subject. In…

  14. Reconnaissance of the hydrology, water quality, and sources of bacterial and nutrient contamination in the Ozark Plateaus aquifer system and Cave Springs Branch of Honey Creek, Delaware County, Oklahoma, March 1999-March 2000

    Science.gov (United States)

    Schlottmann, Jamie L.; Tanner, Ralph S.; Samadpour, Mansour

    2000-01-01

    A reconnaissance investigation of hydrology and water quality was conducted to evaluate possible sources of bacteria and nutrient contamination in the Cave Springs Branch basin and the underlying karstic Ozark Plateau aquifer system. Objectives were to: (1) determine the directions of ground-water flow in the basin and determine whether Cave Springs Branch interacts with ground water, (2) compare water quality in Cave Springs Branch with water quality in nearby wells to determine whether the stream is contaminating nearby wells, and (3) determine sources of fecal coliform bacteria and nitrate contamination in Cave Springs Branch and ground water. Potential sources of bacteria and nitrate in the area include cultivated agriculture, cow and horse on pasture, poultry production, households, and wildlife. Presence of fecal coliform and fecal streptococcal bacteria directly indicate fecal contamination and the potential for the presence of other pathogenic organisms in a water supply. Nitrate in drinking water poses health risks and may indicate the presence of additional contaminants. Fecal coliform bacteria colony counts were least in wells, intermediate in the poultry-processing plant wastewater outfall and Honey Creek above the confluence with Cave Springs Branch, and greatest in Cave Springs Branch. Bacteria strains and resistance to antibiotics by some bacteria indicate that livestock may have been sources of some bacteria in the water samples. Multiple antibiotic resistances were not present in the isolates from the water samples, indicating that the bacteria may not be from human or poultry sources. Ribotyping indicates that Escherichia coli bacteria in water samples from the basin were from bird, cow, horse, dog, deer, and human sources. The presence of multiple ribotypes from each type of animal source except bird indicates that most of the bacteria are from multiple populations of source animals. Identifiable sources of bacteria in Cave Springs Branch at the

  15. Evidence of chronic anthropogenic nutrient within coastal lagoon reefs adjacent to urban and tourism centers, Kenya: A stable isotope approach.

    Science.gov (United States)

    Mwaura, Jelvas; Umezawa, Yu; Nakamura, Takashi; Kamau, Joseph

    2017-06-30

    The source of anthropogenic nutrient and its spatial extent in three fringing reefs with differing human population gradients in Kenya were investigated using stable isotope approaches. Nutrient concentrations and nitrate-δ 15 N in seepage water indicated that population density and tourism contributed greatly to the extent of nutrient loading to adjacent reefs. Although water-column nutrient analyses did not show any significant difference among the reefs, higher δ 15 N and N contents in macrophytes showed terrestrial nutrients affected primary producers in onshore areas in Nyali and Bamburi reefs, but were mitigated by offshore water intrusion especially at Nyali. On the offshore reef flat, where the same species of macroalgae were not available, complementary use of δ 15 N in sedimentary organic matter suggested inputs of nutrients originated from the urban city of Mombasa. If population increases in the future, nutrient conditions in the shallower reef, Vipingo, may be dramatically degraded due to lower water exchange ratio. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Intertidal Sandbar Welding as a Primary Source of Sediment for Dune Growth: Evidence from a Large Scale Field Experiment

    Science.gov (United States)

    Cohn, N.; Ruggiero, P.; de Vries, S.

    2016-12-01

    Dunes provide the first line of defense from elevated water levels in low-lying coastal systems, limiting potentially major flooding, economic damages, and loss of livelihood. Despite the well documented importance of healthy dunes, our predictive ability of dune growth, particularly following erosive storm events, remains poor - resulting in part from traditionally studying the wet and dry beach as separate entities. In fact, however, dune recovery and growth is closely tied to the subtidal morphology and the nearshore hydrodynamic conditions, necessitating treating the entire coastal zone from the shoreface to the backshore as an integrated system. In this context, to further improve our understanding of the physical processes allowing for beach and dune growth during fair weather conditions, a large field experiment, the Sandbar-aEolian Dune EXchange EXperiment, was performed in summer 2016 in southwestern Washington, USA. Measurements of nearshore and atmospheric hydrodynamics, in-situ sediment transport, and morphology change provide insight into the time and space scales of nearshore-beach-dune exchanges along a rapidly prograding stretch of coast over a 6 week period. As part of this experiment, the hypothesis that dune growth is limited by the welding of intertidal sandbars to the shoreline (Houser, 2009) was tested. Using laser particle counters, bed elevation sensors (sonar altimeters and Microsoft Kinect), continuously logging sediment traps, RGB and IR cameras, and repeat morphology surveys (terrestrial lidar, kite based structure from motion, and RTK GPS), spatial and temporal trends in aeolian sediment transport were assessed in relation to the synoptic onshore migration and welding of intertidal sandbars. Observations from this experiment demonstrate that (1) the intertidal zone is the primary source of sediment to the dunes during non-storm conditions, (2) rates of saltation increase during later stages of bar welding but equivalent wind conditions

  17. Effects of Storm Events on Bacteria and Nutrients in the Bayou Chico Watershed

    Science.gov (United States)

    Hobbs, S. E.; Truong, S.

    2017-12-01

    Levels of Escherichia coli and abiotic nutrients often increase in response to storm events due to urban runoff. The urban setting, aging septic systems, and ample pet waste (predominant sources of bacterial and nutrient contamination) that surround Bayou Chico, provide abundant possibilities for contamination. E. coli is a gram-negative, rod shaped bacteria commonly found in the intestines of animals; while some strains are harmless, others produce dangerous toxins that can cause side effects and sometimes death. Along with E. coli, inorganic nutrient concentrations (orthophosphate, nitrate/nitrite, and ammonium) are key indicators of water quality. Dissolved nutrients promote the growth of primary producers and excessive amounts lead to algal blooms, often reducing biodiversity. Four sites were sampled weekly in June and July 2017; during which, June had the highest rainfall in comparison to the past three years; these four sites represented three different sub-watersheds of the Bayou Chico Watershed, with differing land-use at each site. Historical nutrient and bacterial data from the Bream Fishermen Association was also compared and examined to determine long term trends and obtain a more in-depth understanding of the dynamics of water quality in th urban setting. E. coli levels were universally high (ranging from 98 to 12,997 MPN/100mL) for all sites and did not show observable correlations to rainfall; possibly influenced by the systemic and anomalous heavy precipitation during most of the summer study period. Nitrate was detected at levels between 2.5 and 154.0 µM, while ammonium levels ranged from 0 to 16.1 µM. Three of four stations showed extremely elevated dissolved inorganic nitrogen and ammonium while one station showed low levels of these nutrients. Correlations between these nutrient loads and rainfall, support the hypothesis that runoff into tributary creeks contributes significant inorganic nutrient loads to the Bayou Chico urban estuary.

  18. Ecosystem responses to long-term nutrient management in an urban estuary: Tampa Bay, Florida, USA

    Science.gov (United States)

    Greening, H.; Janicki, A.; Sherwood, E. T.; Pribble, R.; Johansson, J. O. R.

    2014-12-01

    In subtropical Tampa Bay, Florida, USA, we evaluated restoration trajectories before and after nutrient management strategies were implemented using long-term trends in nutrient loading, water quality, primary production, and seagrass extent. Following citizen demands for action, reduction in wastewater nutrient loading of approximately 90% in the late 1970s lowered external total nitrogen (TN) loading by more than 50% within three years. Continuing nutrient management actions from public and private sectors were associated with a steadily declining TN load rate and with concomitant reduction in chlorophyll-a concentrations and ambient nutrient concentrations since the mid-1980s, despite an increase of more than 1 M people living within the Tampa Bay metropolitan area. Water quality (chlorophyll-a concentration, water clarity as indicated by Secchi disk depth, total nitrogen concentration and dissolved oxygen) and seagrass coverage are approaching conditions observed in the 1950s, before the large increases in human population in the watershed. Following recovery from an extreme weather event in 1997-1998, water clarity increased significantly and seagrass is expanding at a rate significantly different than before the event, suggesting a feedback mechanism as observed in other systems. Key elements supporting the nutrient management strategy and concomitant ecosystem recovery in Tampa Bay include: 1) active community involvement, including agreement about quantifiable restoration goals; 2) regulatory and voluntary reduction in nutrient loadings from point, atmospheric, and nonpoint sources; 3) long-term water quality and seagrass extent monitoring; and 4) a commitment from public and private sectors to work together to attain restoration goals. A shift from a turbid, phytoplankton-based system to a clear water, seagrass-based system that began in the 1980s following comprehensive nutrient loading reductions has resulted in a present-day Tampa Bay which looks and

  19. Influence of cross-shelf water transport on nutrients and phytoplankton in the East China Sea: a model study

    Directory of Open Access Journals (Sweden)

    L. Zhao

    2011-01-01

    Full Text Available A three dimensional coupled biophysical model was used to examine the supply of oceanic nutrients to the shelf of the East China Sea (ECS and its role in primary production over the shelf. The model consisted of two parts: the hydrodynamic module was based on a nested model with a horizontal resolution of 1/18 degree, whereas the biological module was a lower trophic level ecosystem model including two types of phytoplankton, three elements of nutrients, and biogenic organic material. The model results suggested that seasonal variations occurred in the distribution of nutrients and chlorophyll a over the shelf of the ECS. After comparison with available observed nutrients and chlorophyll a data, the model results were used to calculate volume and nutrients fluxes across the shelf break. The annual mean total fluxes were 1.53 Sv for volume, 9.4 kmol s−1 for DIN, 0.7 kmol s−1 for DIP, and 18.2 kmol s−1 for silicate. Two areas, northeast of Taiwan and southwest of Kyushu, were found to be major source regions of oceanic nutrients to the shelf. Although the onshore fluxes of nutrients and volume both had apparent seasonal variations, the seasonal variation of the onshore nutrient flux did not exactly follow that of the onshore volume flux. Additional calculations in which the concentration of nutrients in Kuroshio water was artificially increased suggested that the oceanic nutrients were distributed in the bottom layer from the shelf break to the region offshore of the Changjiang estuary from spring to summer and appeared in the surface layer from autumn to winter. The calculations also implied that the supply of oceanic nutrients to the shelf can change the consumption of pre-existing nutrients from rivers. The response of primary production over the shelf to the oceanic nutrients was confirmed not only in the surface layer (mainly at the outer shelf and shelf break in winter and in the region

  20. Fontes de carboidratos e ionóforo em dietas contendo óleo vegetal para ovinos: digestibilidade, balanço de nitrogênio e fluxo portal de nutrientes Carbohydrate sources and ionophore in sheep diets with vegetal oil: digestibility, nitrogen balance and portal flux of nutrients

    Directory of Open Access Journals (Sweden)

    Gisele Fernanda Mouro

    2006-10-01

    Full Text Available Os objetivos neste trabalho foram avaliar a utilização de duas fontes de carboidratos (casca de soja e milho, com a utilização ou não de monensina em dietas com alta densidade lipídica, e seus efeitos sobre a digestibilidade dos nutrientes, o balanço de nitrogênio e o fluxo portal de nutrientes em ovinos. Adotou-se o método de coleta total de fezes e urina para determinação da digestibilidade e do balanço de nitrogênio. O fluxo líquido de nutrientes foi calculado pelo princípio de Fick. Foram utilizados quatro ovinos (54 kg de PV da raça Corriedale com três cateteres implantados (veia e artéria mesentérica e veia porta. A ingestão, a excreção fecal, a digestão e a digestibilidade de MS, MO e EE não foram influenciadas pelos tratamentos. A ingestão, a digestão e a digestibilidade da FDN foram maiores para as dietas com casca de soja (757,0; 531,1 g/dia e 70,2% que para aquelas com milho (392,3; 199,9 g/dia e 51,0%, enquanto a dos carboidratos não-fibrosos (CNF, foram maiores para as dietas com milho (474,6, 416,8 g/dia e 87,8% que para aquelas com casca de soja (148,0; 97,8 g/dia e 66,1%. A concentração de energia expressa como NDT foi maior nas dietas com milho (80,2% que naquelas com casca de soja (76,7%. Não houve efeito da utilização da monensina nos parâmetros de digestibilidade e balanço de nitrogênio. A excreção fecal da proteína foi menor e a digestibilidade maior para as dietas com milho. A concentração portal e arterial de nitrogênio alfa amino (N alfa-amino foi menor para as dietas com monensina (3,161 e 2,922 e 3,530 e 3,218 mM, respectivamente. A concentração portal (0,419 vs 0,516 mM, a diferença venosa-arterial (0,230 vs 0,317 mM e o fluxo portal de amônia (26,119 vs 37,041 mM/h foram menores para as dietas com milho.The objectives of this trial were to evaluate the effects of two carbohydrate sources (soybean hulls and corn grain with and without monensin on digestibility, nitrogen

  1. Nutrients fluxes from groundwater discharge into Mangueira Lagoon (Rio Grande do Sul, Brazil); Fluxos de nutrientes associados as descargas de agua subterranea para a Lagoa Mangueira (Rio Grande do Sul, Brasil)

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Carlos F.F.; Niencheski, Luis F.H.; Attisano, Karina K.; Milani, Marcio R., E-mail: pgofcfa@furg.br [Instituto de Oceanografia, Universidade Federal do Rio Grande, Campus Carreiros, Rio Grande, RS (Brazil); Santos, Isaac R. [Department of Oceanography, Florida State University, Tallahassee, FL (United States); Milani, Idel C. [Departamento de Engenharia Hidrica, Centro de Desenvolvimento Tecnologico, Universidade Federal de Pelotas, Campus Porto, Pelotas, RS (Brazil)

    2012-07-01

    This study assesses the importance of groundwater discharge to dissolved nutrient levels in Mangueira Lagoon. A transect of an irrigation canal in the margin of Lagoon demonstrated a strong geochemical gradient due to high groundwater inputs in this area. Using {sup 222}Rn as a quantitative groundwater tracer, we observed that the flux of dissolved inorganic nitrogen (DIN), silicate and phosphate (1178 and 1977; 26190 and 35652; 167 and 188 mol d{sup -1} for winter and summer, respectively) can continually supply/sustain primary production. The irrigation canals act as an artificial underground tributary and represent a new source of nutrients to coastal lagoons. (author)

  2. Amount of nutrients in stalk of sugar cane as a function of sources and doses of manganeseAcúmulo de nutrientes no colmo de cana-de-açúcar em função de fontes e doses de manganês

    Directory of Open Access Journals (Sweden)

    Cleiton Gredson Sabin Benett

    2013-06-01

    Full Text Available The low productivity of sugarcane crop in some areas can be correlated with the lack of nutrients due to cane sugar crop be a major exporter of nutrients. The objective this study was to evaluate the effect of five doses and three sources of manganese applied in the planting furrow in sugar cane plant and its residual effects on ratoon cane, in the northwest region of São Paulo. The experiment was conducted at the site Fujimoto, area administered by the Valley Distillery Parana S/A Sugar and Alcohol in Suzanápolis – SP. The experimental design was randomized blocks in a factorial scheme 5x3, with five doses of manganese (0, 2.5, 5.0, 7.5 and 10.0 kg ha-1 and three sources (sulfate, chelate and FTE, applied at planting furrow in 4 repetitions. The plots consisted of four rows 5 m long, spaced by 1.5 m. The variety used was RB 86-7515. We assessed the accumulation of macro and micronutrients in stems, dry matter yield of stalks and stems. The sources and doses of manganese influenced the accumulation of macro and micronutrients and the dry stalks of sugar cane plant and ratoon cane. The stalk productivity was not affected by doses and sources of manganese in any crops. A baixa produtividade dos canaviais em algumas áreas pode estar relacionada a exigência e exportação da cultura da cana-de-açúcar. O objetivo deste estudo foi avaliar o efeito de cinco doses e três fontes de manganês aplicadas no sulco de plantio na cultura da cana-de-açúcar em cana planta e seu efeito residual em cana soca. O experimento foi conduzido no sítio Fujimoto, área administrada pela Destilaria Vale do Paraná S/A Álcool e Açúcar, no município de Suzanápolis – SP. O delineamento experimental utilizado foi o de blocos ao acaso arranjado em esquema fatorial 5x3, sendo cinco doses de manganês (0; 2,5; 5,0; 7,5 e 10,0 kg ha-1 e três fontes (sulfato de manganês, quelato e FTE BR 12, aplicadas no sulco de plantio, com 4 repetições. As parcelas foram

  3. Nutrient load estimates for Manila Bay, Philippines using population data

    NARCIS (Netherlands)

    Sotto, Lara Patricia A; Beusen, Arthur H W; Villanoy, Cesar L.; Bouwman, Lex F.; Jacinto, Gil S.

    2015-01-01

    A major source of nutrient load to periodically hypoxic Manila Bay is the urban nutrient waste water flow from humans and industries to surface water. In Manila alone, the population density is as high as 19,137 people/km2. A model based on a global point source model by Morée et al. (2013) was used

  4. Produtividade, qualidade dos frutos e estado nutricional do tomateiro tipo longa vida conduzido com um cacho, em cultivo hidropônico, em função das fontes de nutrientes Productivity, fruit quality and nutritional status of single truss long shelf life tomato, cultivated in hydroponic system, with different nutrient sources

    Directory of Open Access Journals (Sweden)

    Adriano A. Fernandes

    2002-12-01

    Full Text Available Avaliou-se a produtividade, qualidade dos frutos e estado nutricional do tomateiro longa vida, conduzido com um cacho e cultivado em soluções nutritivas preparadas com diferentes conjuntos de fontes de nutrientes. O experimento foi conduzido de 04/05/99 a 13/09/99 em casa de vegetação da UFV. Foram avaliados dois conjuntos de fontes de nutrientes para compor as soluções de crescimento vegetativo e dois para as soluções de frutificação. As combinações desses conjuntos deram origem a quatro tratamentos que foram dispostos no delineamento de blocos ao acaso com oito repetições. As mudas de tomate, híbrido Carmen, com 36 dias de idade foram colocadas em vasos de 8,6 L, com espaçamento de 0,35 x 0,70 m. Foi feita análise foliar para determinar o estado nutricional da planta. Avaliou-se também a partição dos nutrientes Ca, Mg e K no fruto. Os dados obtidos foram submetidos à análise de variância e as médias dos tratamentos, comparadas pelo teste de Tukey a 5% de probabilidade. Para as características avaliadas não foram encontradas diferenças significativas entre os tratamentos. A produção média de frutos por planta foi de 920 g, com ciclo de 96 dias, o que corresponderia no espaçamento adotado à produtividade média de 142 t ha-1 ano-1. A concentração de N, P, K, Ca, Mg e S, nas folhas foram, respectivamente, 3,18; 1,25; 5,11; 4,50; 0,88; e 1,79 dag kg-1, e as concentrações de Fe, Zn, Cu, Mn e B foram, respectivamente, 209; 96; 10; 665; e 209 mg kg-1. No fruto o Ca e K apresentaram maior concentração na região proximal ao pedúnculo, ao contrário do Mg, que nessa porção apresentou menor concentração.There were evaluated the yield, fruit quality and nutritional status of single truss and long shelf life tomato, cultivated in nutritive solutions prepared with different nutrient sources. The experiment was carried out from 04/05/99 to 13/09/99 in a greenhouse of the Universidade Federal de Viçosa, Brazil. Two

  5. Coupling of the spatial-temporal distributions of nutrients and physical conditions in the southern Yellow Sea

    Science.gov (United States)

    Wei, Qin-Sheng; Yu, Zhi-Gang; Wang, Bao-Dong; Fu, Ming-Zhu; Xia, Chang-Shui; Liu, Lu; Ge, Ren-Feng; Wang, Hui-Wu; Zhan, Run

    2016-04-01

    This study investigated the coupling of the spatial-temporal variations in nutrient distributions and physical conditions in the southern Yellow Sea (SYS) using data compiled from annual-cycle surveys conducted in 2006-2007 as well as satellite-derived sea-surface temperature (SST) images. The influence of physical dynamics on the distribution and transport of nutrients varied spatially and seasonally in the SYS. The Changjiang Diluted Water (CDW) plume (in summertime), the Subei Coastal Water (SCW) (year-round), and the Lubei Coastal Current (LCC) (in wintertime) served as important sources of nutrients in the inshore area in a dynamic environment. The saline Taiwan Warm Current (TWC) might transport nutrients to the northeast region of the Changjiang Estuary in the summer, and this nutrient source began to increase from spring to summer and decrease when autumn arrived. Three types of nutrient fronts, i.e., estuarine, offshore, and coastal, were identified. A circular nutrient front caused by cross-shelf transport of SCW in the southeast shelf bank area in the winter and spring was observed. The southeastward flow of western coastal cold water in the SYS might be an important conduit for cross-shelf nutrient exchange between the SYS and the East China Sea (ECS). The tongue-shaped low-nutrient region in the western study area in the wintertime was driven by the interaction of the southward Yellow Sea Western Coastal Current (YSWCC) and the biological activity. The vertically variable SCM (subsurface Chl-a maximum) in the central SYS was controlled by coupled physical-chemical processes that involved stratification and associated nutricline. The average nutrient fluxes into the euphotic zone due to upwelling near the frontal zone of the Yellow Sea Cold Water Mass (YSCWM) in the summer are estimated here for the first time: 1.4 ± 0.9 × 103 μmol/m2/d, 0.1 ± 0.1 × 103 μmol/m2/d, and 2.0 ± 1.3 × 103 μmol/m2/d for DIN, PO4-P, and SiO3-Si, respectively. The

  6. Spatiotemporal patterns of livestock manure nutrient production in the conterminous United States from 1930 to 2012.

    Science.gov (United States)

    Yang, Qichun; Tian, Hanqin; Li, Xia; Ren, Wei; Zhang, Bowen; Zhang, Xuesong; Wolf, Julie

    2016-01-15

    Manure nitrogen (N) and phosphorus (P) from livestock husbandry are important components of terrestrial biogeochemical cycling. Assessment of the impacts of livestock manure on terrestrial biogeochemistry requires a compilation and analysis of spatial and temporal patterns of manure nutrients. In this study, we reconstructed county-level manure nutrient data of the conterminous United States (U.S.) in 4- to 5-year increments from 1930 to 2012. Manure N and P were 5.8 9 ± 0.64 Tg N yr.(-1) (Mean ± Standard Deviation) and 1.73 ± 0.29 Tg Pyr.(-1) (1 Tg = 10(12)g), and increased by 46% and 92% from 1930 to 2012, respectively. Prior to 1970, manure provided more N to the U.S. lands than chemical fertilizer use. Since 1970, however, increasing chemical N fertilizer use has exceeded manure N production. Manure was the primary P source in the U.S. during 1930-1969 and 1987-2012, but was lower than P fertilizer use in 1974, 1978, and 1982. High-nutrient-production regions shifted towards eastern and western areas of the U.S. Decreasing small farms and increasing Concentrated Animal Feeding Operations (CAFOs) induced concentrated spatial patterns in manure nutrient loads. Counties with cattle or poultry as the primary manure nutrient contributors expanded significantly from 1930 to 2012, whereas regions with sheep and hog as the primary contributors decreased. We identified regions facing environmental threats associated with livestock farming. Effective management of manure should consider the impacts of CAFOs in manure production, and changes in livestock population structure. The long-term county-level manure nutrient dataset provides improved spatial and temporal information on manure nutrients in the U.S. This dataset is expected to help advance research on nutrient cycling, ammonia volatilization, greenhouse gas (GHG) emissions from livestock husbandry, recovery and reuse of manure nutrients, and impacts of livestock feeding on human health in the context of global

  7. Linking nutrient enrichment, sediment erodibility and biofilms

    Science.gov (United States)

    Conrad, B.; Mahon, R.; Sojka, S. L.

    2014-12-01

    Sediment movement in coastal lagoons affects nutrient flux and primary producer growth. Previous research has shown that sediment erodibility is affected by biofilm concentration and that growth of benthic organisms, which produce biofilm, is affected by nutrient enrichment. However, researchers have not examined possible links between nutrient addition and sediment erodibility. We manipulated nutrient levels in the water column of 16 microcosms filled with homogenized sediment from a shallow coastal lagoon and artificial seawater to determine the effects on biofilm growth, measured through chlorophyll a and colloidal carbohydrate concentrations. Erosion tests using a Gust microcosm were conducted to determine the relationship between sediment erodibility and biofilm concentration. Results show that carbohydrate levels decreased with increasing nutrient enrichment and were unrelated to chlorophyll concentrations and erodibility. The nutrient levels did not predictably affect the chlorophyll levels, with lower chlorophyll concentrations in the control and medium enrichment treatments than the low and high enrichment treatments. Controls on biofilm growth are still unclear and the assumed relationship between carbohydrates and erodibility may be invalid. Understanding how biofilms respond to nutrient enrichment and subsequent effects on sediment erodibility is essential for protecting and restoring shallow coastal systems.

  8. Nutrient management for rice production

    International Nuclear Information System (INIS)

    Khan, A.R.; Chandra, D.; Nanda, P.; Singh, S.S.; Singh, S.R.; Ghorai, A.K.

    2002-06-01

    The nutrient removed by the crops far exceeds the amounts replenished through fertilizer, causing a much greater strain on the native soil reserves. The situation is further aggravated in countries like India, where sub-optimal fertilizer used by the farmers is a common phenomenon rather than an exception. The total consumption of nutrients of all crops in India, even though reached 15 million tons in 1997, remains much below the estimated nutrient removal of 25 million tons (Swarup and Goneshamurthy, 1998). The gap between nutrient removal supplied through fertilizer has widened further in 2000 to 34 million tons of plant nutrients from the soil against an estimated fertilizer availability of 18 million tons (Singh and Dwivedi, 1996). Nitrogen is the nutrient which limits the most the rice production worldwide. In Asia, where more than 90 percent of the world's rice is produced, about 60 percent of the N fertilizer consumed is used on rice (Stangel and De Dutta, 1985). Conjunctive use of organic material along with fertilizer has been proved an efficient source of nitrogen. Organic residue recycling is becoming an increasingly important aspect of environmentally sound sustainable agriculture. Returning residues like green manure to the soil is necessary for maintaining soil organic matter, which is important for favourable soil structure, soil water retention and soil microbial flora and fauna activities. Use of organic manures in conjunction or as an alternative to chemical fertilizer is receiving attention. Green manure, addition to some extent, helps not only in enhancing the yield but also in improving the physical and chemical nature of soils. The excessive application of chemical fertilizers made it imperative that a part of inorganic fertilizer may be substituted with the recycling of organic wastes. Organic manure has been recorded to enhance the efficiency and reduce the requirement of chemical fertilizers. Partial nitrogen substitution through organic

  9. Tree root systems and nutrient mobilization

    DEFF Research Database (Denmark)

    Boyle, Jim; Rob, Harrison; Raulund-Rasmussen, Karsten

    sometimes stored at depth. Other recent studies on potential release of nutrients due to chemical weathering indicate the importance of root access to deep soil layers. Release profi les clearly indicate depletion in the top layers and a much higher potential in B and C horizons. Review of evaluations......Roots mobilize nutrients via deep penetration and rhizosphere processes inducing weathering of primary minerals. These contribute to C transfer to soils and to tree nutrition. Assessments of these characteristics and processes of root systems are important for understanding long-term supplies...... of nutrient elements essential for forest growth and resilience. Research and techniques have signifi cantly advanced since Olof Tamm’s 1934 base mineral index for Swedish forest soils, and basic nutrient budget estimates for whole-tree harvesting systems of the 1970s. Recent research in areas that include...

  10. Valor do farelo de arroz integral como fonte de gordura na dieta de vacas Jersey na fase inicial de lactação: digestibilidade aparente de nutrientes Value of rice bran as a fat source for Jersey cows in early lactation: apparent digestibility of nutrients

    Directory of Open Access Journals (Sweden)

    José Laerte Nörnberg

    2004-12-01

    Full Text Available Foram utilizadas oito vacas Jersey, com peso médio de 420 kg, produção média de 20 kg de leite corrigida para 3,5% de gordura, na fase inicial de lactação (próximas ao pico de lactação, estabuladas em baias individuais, distribuídas em dois quadrados latinos (4 x 4. Objetivou-se avaliar a potencialidade do farelo de arroz integral como fonte de gordura, associado a óleo de arroz e a sebo bovino, em dietas isoprotéicas, isofibrosas e isolipídicas entre as fontes de gordura estudadas, por meio da digestibilidade aparente dos nutrientes. Os tratamentos foram: CON- concentrado sem adição de gordura; GP- concentrado com gordura protegida; FAIO- concentrado com farelo de arroz integral e óleo de arroz; FAIS- concentrado com farelo de arroz integral e sebo bovino. Os concentrados foram à base de grãos de milho moído e farelo de soja, e, como volumosos, foram empregados silagem de milho e feno de alfafa (1:1. O concentrado foi fornecido três vezes ao dia, separadamente dos volumosos. Os volumosos foram fornecidos à vontade, procurando-se manter a proporção de 55% em relação às misturas concentradas. A estimativa da excreção fecal foi obtida com emprego de óxido de cromo e a digestibilidade da gordura por diferença. A interpretação estatística foi feita pela análise de variância dos valores médios de cada tratamento pelo teste F. As fontes de gordura não afetaram a digestibilidade aparente da matéria seca, matéria orgânica, proteína bruta, fibra em detergente neutro e de carboidratos não-fibrosos. O farelo de arroz integral pode ser usado como fonte de gordura, totalizando 6% de gordura bruta na dieta de vacas leiteiras na fase inicial da lactação.Eight Jersey cows with an average live weight of 420 kg, yielding around 20 kg of 3.5% FCM in early lactation (around the peak of lactation were used in a trial whose objectives were to evaluate rice bran as fat source associated with oil or tallow in iso-proteic, iso

  11. Systematic Multi-variable H-infinity Control Design for Primary Frequency Regulation in Stand-alone Microgrids with High Penetration of Renewable Energy Sources

    OpenAIRE

    Lam , Quang Linh; Bratcu , Antoneta Iuliana; Riu , Delphine

    2016-01-01

    International audience; In this paper, a systematic design of a robust multi-variable control structure for primary frequency regulation in microgrids with high rate of renewable source penetration is proposed. The considered microgrid represents a diesel-photovoltaic-supercapacitor hybrid power generation system operating in stand-alone mode. The proposed control structure relies on a two-level architecture: classical PI-based current tracking controllers are placed on the low control level ...

  12. Food Sources of Important Nutrients (for Vegetarians)

    Science.gov (United States)

    ... include dairy products, calcium can be obtained from plant-based foods, but the amount of calcium that ... or fat-free milk, yogurt and cheese Fortified plant-based milks such as soy or almond Fortified ...

  13. Spatial variability of primary organic sources regulates ichthyofauna distribution despite seasonal influence in Terminos lagoon and continental shelf of Campeche, Mexico

    Science.gov (United States)

    Romo Rios, J. A.; Aguíñiga-García, S.; Sanchez, A.; Zetina-Rejón, M.; Arreguín-Sánchez, F.; Tripp-Valdéz, A.; Galeana-Cortazár, A.

    2013-05-01

    Human activities have strong impacts on coastal ecosystems functioning through their effect on primary organic sources distributions and resulting biodiversity. Hence, it appears to be of utmost importance to quantify contribution of primary producers to sediment organic matter (SOM) spatial variability and its associated ichthyofauna. The Terminos lagoon (Gulf of Mexico) is a tropical estuary severely impacted by human activities even though of primary concern for its biodiversity, its habitats, and its resource supply. Stable isotope data (d13C, d15N) from mangrove, seaweed, seagrass, phytoplankton, ichthyofauna and SOM were sampled in four zones of the lagoon and the continental shelf through windy (November to February), dry (March to June) and rainy (July to October) seasons. Stable Isotope Analysis in R (SIAR) mixing model were used to determine relative contributions of the autotrophic sources to the ichthyofauna and SOM. Analysis of variance of ichthyofauna isotopic values showed significant differences (P < 0.001) in the four zones of lagoon despite the variability introduced by the windy, dry and rainy seasons. In lagoons rivers discharge zone, the mangrove contribution to ichthyofauna was 40% and 84% to SOM. Alternative use of habitat by ichthyofauna was evidenced since in the deep area of the lagoon (4 m), the contribution of mangrove to fish is 50%, and meanwhile contribution to SOM is only 77%. Although phytoplankton (43%) and seaweed (41%) contributions to the adjacent continental shelf ichthyofauna were the main organic sources, there was 37% mangrove contribution to SOM, demonstrating conspicuous terrigenous influence from lagoon ecosystem. Our results point toward organic sources spatial variations that regulate fish distribution. In Terminos lagoon, significant correlation (p-value = 0.2141 and r=0.79) of Ariopsis felis and Sphoeroides testudineus abundances and seaweed and seagrasses contributions (30-35%) during both dry and rainy seasons

  14. In the other 90%: phytoplankton responses to enhanced nutrient availability in the Great Barrier Reef Lagoon

    International Nuclear Information System (INIS)

    Furnas, Miles; Mitchell, Alan; Skuza, Michele; Brodie, Jon

    2005-01-01

    Our view of how water quality effects ecosystems of the Great Barrier Reef (GBR) is largely framed by observed or expected responses of large benthic organisms (corals, algae, seagrasses) to enhanced levels of dissolved nutrients, sediments and other pollutants in reef waters. In the case of nutrients, however, benthic organisms and communities are largely responding to materials which have cycled through and been transformed by pelagic communities dominated by micro-algae (phytoplankton), protozoa, flagellates and bacteria. Because GBR waters are characterised by high ambient light intensities and water temperatures, inputs of nutrients from both internal and external sources are rapidly taken up and converted to organic matter in inter-reefal waters. Phytoplankton growth, pelagic grazing and remineralisation rates are very rapid. Dominant phytoplankton species in GBR waters have in situ growth rates which range from ∼1 to several doublings per day. To a first approximation, phytoplankton communities and their constituent nutrient content turn over on a daily basis. Relative abundances of dissolved nutrient species strongly indicate N limitation of new biomass formation. Direct ( 15 N) and indirect ( 14 C) estimates of N demand by phytoplankton indicate dissolved inorganic N pools have turnover times on the order of hours to days. Turnover times for inorganic phosphorus in the water column range from hours to weeks. Because of the rapid assimilation of nutrients by plankton communities, biological responses in benthic communities to changed water quality are more likely driven (at several ecological levels) by organic matter derived from pelagic primary production than by dissolved nutrient stocks alone

  15. Nutrient budgets for large Chinese estuaries

    Directory of Open Access Journals (Sweden)

    S. M. Liu

    2009-10-01

    Full Text Available Chinese rivers deliver about 5–10% of global freshwater input and 15–20% of the global continental sediment to the world ocean. We report the riverine fluxes and concentrations of major nutrients (nitrogen, phosphorus, and silicon in the rivers of the contiguous landmass of China and Korea in the northeast Asia. The rivers are generally enriched with dissolved inorganic nitrogen (DIN and depleted in dissolved inorganic phosphate (PO43− with very high DIN: PO43− concentration ratios. DIN, phosphorus, and silicon levels and loads in rivers are mainly affected by agriculture activities and urbanization, anthropogenic activities and adsorption on particulates, and rock types, climate and physical denudation intensity, respectively. Nutrient transports by rivers in the summer are 3–4 times higher than those in the winter with the exception of NH4+. The flux of NH4+ is rather constant throughout the year due to the anthropogenic sources such as the sewer discharge. As nutrient composition has changed in the rivers, ecosystems in estuaries and coastal sea have also changed in recent decades. Among the changes, a shift of limiting nutrients from phosphorus to nitrogen for phytoplankton production with urbanization is noticeable and in some areas silicon becomes the limiting nutrient for diatom productivity. A simple steady-state mass-balance box model was employed to assess nutrient budgets in the estuaries. The major Chinese estuaries export <15% of nitrogen, <6% of phosphorus required for phytoplankton production and ~4% of silicon required for diatom growth in the Chinese Seas (Bohai, Yellow Sea, East China Sea, South China Sea. This suggests that land-derived nutrients are largely confined to the immediate estuaries, and ecosystem in the coastal sea beyond the estuaries is mainly supported by other nutrient sources such as regeneration, open ocean and

  16. Variable nutrient stoichiometry (carbon:nitrogen:phosphorus) across trophic levels determines community and ecosystem properties in an oligotrophic mangrove system.

    Science.gov (United States)

    Scharler, U M; Ulanowicz, R E; Fogel, M L; Wooller, M J; Jacobson-Meyers, M E; Lovelock, C E; Feller, I C; Frischer, M; Lee, R; McKee, K; Romero, I C; Schmit, J P; Shearer, C

    2015-11-01

    Our study investigated the carbon:nitrogen:phosphorus (C:N:P) stoichiometry of mangrove island of the Mesoamerican Barrier Reef (Twin Cays, Belize). The C:N:P of abiotic and biotic components of this oligotrophic ecosystem was measured and served to build networks of nutrient flows for three distinct mangrove forest zones (tall seaward fringing forest, inland dwarf forests and a transitional zone). Between forest zones, the stoichiometry of primary producers, heterotrophs and abiotic components did not change significantly, but there was a significant difference in C:N:P, and C, N, and P biomass, between the functional groups mangrove trees, other primary producers, heterotrophs, and abiotic components. C:N:P decreased with increasing trophic level. Nutrient recycling in the food webs was highest for P, and high transfer efficiencies between trophic levels of P and N also indicated an overall shortage of these nutrients when compared to C. Heterotrophs were sometimes, but not always, limited by the same nutrient as the primary producers. Mangrove trees and the primary tree consumers were P limited, whereas the invertebrates consuming leaf litter and detritus were N limited. Most compartments were limited by P or N (not by C), and the relative depletion rate of food sources was fastest for P. P transfers thus constituted a bottleneck of nutrient transfer on Twin Cays. This is the first comprehensive ecosystem study of nutrient transfers in a mangrove ecosystem, illustrating some mechanisms (e.g. recycling rates, transfer efficiencies) which oligotrophic systems use in order to build up biomass and food webs spanning various trophic levels.

  17. Variable nutrient stoichiometry (carbon:nitrogen:phosphorus) across trophic levels determines community and ecosystem properties in an oligotrophic mangrove system

    Science.gov (United States)

    Scharler, U.M.; Ulanowicz, Robert E.; Fogel, M.L.; Wooller, M.J.; Jacobson-Meyers, M.E.; Lovelock, C.E.; Feller, I.C.; Frischer, M.; Lee, R.; Mckee, Karen L.; Romero, I.C.; Schmit, J.P.; Shearer, C.

    2015-01-01

    Our study investigated the carbon:nitrogen:phosphorus (C:N:P) stoichiometry of mangrove island of the Mesoamerican Barrier Reef (Twin Cays, Belize). The C:N:P of abiotic and biotic components of this oligotrophic ecosystem was measured and served to build networks of nutrient flows for three distinct mangrove forest zones (tall seaward fringing forest, inland dwarf forests and a transitional zone). Between forest zones, the stoichiometry of primary producers, heterotrophs and abiotic components did not change significantly, but there was a significant difference in C:N:P, and C, N, and P biomass, between the functional groups mangrove trees, other primary producers, heterotrophs, and abiotic components. C:N:P decreased with increasing trophic level. Nutrient recycling in the food webs was highest for P, and high transfer efficiencies between trophic levels of P and N also indicated an overall shortage of these nutrients when compared to C. Heterotrophs were sometimes, but not always, limited by the same nutrient as the primary producers. Mangrove trees and the primary tree consumers were P limited, whereas the invertebrates consuming leaf litter and detritus were N limited. Most compartments were limited by P or N (not by C), and the relative depletion rate of food sources was fastest for P. P transfers thus constituted a bottleneck of nutrient transfer on Twin Cays. This is the first comprehensive ecosystem study of nutrient transfers in a mangrove ecosystem, illustrating some mechanisms (e.g. recycling rates, transfer efficiencies) which oligotrophic systems use in order to build up biomass and food webs spanning various trophic levels.

  18. Nutrient storage rates in a national marsh receiving waste water

    Science.gov (United States)

    J.A. Nyman

    2000-01-01

    Artificial wetlands are commonly used to improve water quality in rivers and the coastal zone. In most wetlands associated with rivers, denitrification is probably the primary process that reduces nutrient loading. Where rivers meet oceans, however, significant amounts of nutrients might be permanently buried in wetlands because of global sea-level rise and regional...

  19. USDA updates nutrient values for fast food pizza

    Science.gov (United States)

    Consumption of quick service pizza has increased as Americans are spending more on food away from home. Pizza is consistently a primary Key Food in the USDA National Food and Nutrient Analysis Program (NFNAP) because it is a contributor of more than 14 nutrients of public health significance to the...

  20. Science Self-Efficacy in the Primary Classroom: Using Mixed Methods to Investigate Sources of Self-Efficacy

    Science.gov (United States)

    Webb-Williams, Jane

    2017-04-01

    Self-efficacy has been shown to influence student engagement, effort and performance as well as course selection and future career choice. Extending our knowledge regarding the development of self-efficacy has important implications for educators and for those concerned about the international uptake of science careers. Previous research has identified four sources that may contribute towards self-efficacy: mastery experiences, vicarious experiences, verbal persuasion and physiological/affective states. Very little research has been conducted within the school environment that looks at the formation of these sources and yet early school experiences have been posited to be a key factor in girls' lack of engagement in post compulsory science education. This paper investigates children's self-efficacy beliefs in science and reports on findings from mixed method research conducted with 182 children aged between 10 and 12 years. Classroom data were collected through focus groups, individual interviews and surveys. Findings revealed that although girls and boys held similar levels of academic performance in science, many girls underestimated their capability. The four sources of self-efficacy identified by Bandura (1997) plus self-regulation as an additional source, were evident in the children's descriptions, with boys being more influenced by mastery experience and girls by a combination of vicarious experience and physiological/affective states. Girl's appraisal of information appeared to operate through a heuristic process whereby girls disregarded salient information such as teacher feedback in favour of reliance on social comparison. Contextual factors were identified. Implications for science teachers are discussed.

  1. Family Planning Knowledge: The Role of Social Networks and Primary Care Providers as Information Sources for African American Women

    Science.gov (United States)

    Blackstock, Oni J.; Mba-Jonas, Adamma; Sacajiu, Galit M.

    2010-01-01

    Disparities in the rates of unintended pregnancy have increased for low-income African American women as compared to other groups due, in part, to declining contraception use. Women obtain family planning information from diverse sources, which may ultimately influence contraceptive decision making. For this qualitative study, we conducted…

  2. ORGANIZATIONAL SOURCES OF STRESS IN PRIMARY SCHOOL TEACHER AND THEIR RELACIONSHIP TO THE NUMBER OF PUPILS TAUGHT

    Directory of Open Access Journals (Sweden)

    Guadalupe Madrigal Olivas

    2014-12-01

    Full Text Available The objectives of this research are: Identify sources of organizational stressors on teachers and establish the relationship between the level of organizational stress and the number of students attending teachers. To achieve these objectives, a non-experimental, cross-sectional correlational study was conducted through the application of the Organizational Sources of Stress Teachers Scale (EFOED to 59 teachers of School District No. 5 of the Ministry of State Education Durango, Mexico. Their main results suggest that uncertainty by the new educational reforms and their impact on labor rights is a situation that creates instability in the educational work of teachers, coupled with this lack of information on it and the constant rumors that generated around it.

  3. Organizational sources of stress in primary school teacher and their relacionship to the number of pupils taught

    Directory of Open Access Journals (Sweden)

    Guadalupe Madrigal Olivas

    2014-12-01

    Full Text Available The objectives of this research are: Identify sources of organizational stressors on teachers and establish the relationship between the level of organizational stress and the number of students attending teachers. To achieve these objectives, a non-experimental, cross-sectional correlational study was conducted through the application of the Organizational Sources of Stress Teachers Scale (EFOED to 59 teachers of School District No. 5 of the Ministry of State Education Durango, Mexico. Their main results suggest that uncertainty by the new educational reforms and their impact on labor rights is a situation that creates instability in the educational work of teachers, coupled with this lack of information on it and the constant rumors that generated around it.

  4. Recycle of Inorganic Nutrients for Hydroponic Crop Production Following Incineration of Inedible Biomass

    Science.gov (United States)

    Bubenheim, David L.; Wignarajah, Kanapathipillai; Kliss, Mark H. (Technical Monitor)

    1996-01-01

    Recovery of resources from waste streams is essential for future implementation and reliance on a regenerative life support system. The major waste streams of concern are from human activities and plant wastes. Carbon, water and inorganics are the primary desired raw materials of interest. The goal of resource recovery is maintenance of product quality to insure support of reliable and predictable levels of life support function performance by the crop plant component. Further, these systems must be maintained over extended periods of time, requiring maintenance of nutrient solutions to avoid toxicity and deficiencies. Today, reagent grade nutrients are used to make nutrient solutions for hydroponic culture and these solutions are frequently changed during the life cycle or sometimes managed for only one crop life cycle. The focus of this study was to determine the suitability of the ash product following incineration of inedible biomass as a source of inorganic nutrients for hydroponic crop production. Inedible wheat biomass was incinerated and ash quality characterized. The incinerator ash was dissolved in adequate nitric acid to establish a consistent nitrogen concentration in all nutrient solution treatments. Four experimental nutrient treatments were included: control, ash only, ash supplemented to match control, and ash only quality formulated with reagent grade chemicals. When nutrient solutions are formulated using only ash following-incineration of inedible biomass, a balance in solution is established representing elemental retention following incineration and nutrient proportions present in the original biomass. The resulting solution is not identical to the control. This imbalance resulted in suppression of crop growth. When the ash is supplemented with nutrients to establish the same balance as in the control, growth is identical to the control. The ash appears to carry no phytotoxic materials. Growth in solution formulated with reagent grade chemicals

  5. The use of energy in China: Tracing the flow of energy from primary source to demand drivers

    International Nuclear Information System (INIS)

    Ma, Linwei; Allwood, Julian M.; Cullen, Jonathan M.; Li, Zheng

    2012-01-01

    We present a map of the transformation of energy in China as a Sankey diagram. After a review of previous work, and a statement of methodology, our main work has been the identification, evaluation, and treatment of appropriate data sources. This data is used to construct the Sankey diagram, in which flows of energy are traced from energy sources through end-use conversion devices, passive systems and final services to demand drivers. The resulting diagram provides a convenient and clear snapshot of existing energy transformations in China which can usefully be compared with a similar global analysis and which emphasises the potential for improvements in energy efficiency in ‘passive systems’. More broadly, it gives a basis for examining and communicating future energy scenarios, including changes to demand, changes to the supply mix, changes in efficiency and alternative provision of existing services. -- Highlights: ► A Sankey Diagram has been created to show the complete picture of energy transformation in China. ► The Diagram traces energy transformations from source to final service. ► The diagram is organised by technologies, enabling prioritisation and allowing future calculation of efficiencies. ► The diagram is contrasted with an equivalent diagram for global energy use. ► Armed with the diagram we can now examine the system-wide consequences of future changes to China's energy system.

  6. A prototype machine using thermal type Stirling solar energy and bio fuel as a primary energy source

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Carlos Cesar; Sousa, Regina Celia de; Santos, Jose Maria Ramos dos; Oliveira, Antonio Jose Silva [Universidade Federal do Maranhao (UFMA), Sao Luis, MA (Brazil). Dept. de Fisica

    2011-07-01

    Full text. Depending on the energy crisis and global warming became necessary to seek new sources of energy that could minimize the serious problems arising from this situation. The energy base that supported our growth in recent decades has supported - heavily on fossil fuel, highly polluting since its extraction and consumption, causing great environmental impact. Before his coal, also harmful to human health and nature. Modern life has been moved at the expense of exhaustible resources that took millions of years to form and will end one day. In this work we developed a prototype that uses a heat engine cycle of the Stirling engine with a heat source, arising from the burning of bio fuels or solar power. The main bio fuel used was ethanol. Ethanol is a product of today's diverse market applications, widely used as automotive fuel in hydrated form or blended with gasoline. The main layout of our prototype are: the four-cylinder, two for expansion and the other two for compression, a heat spreader and heat sinks. These simple components can be arranged in various configurations allowing a large space to the adequacy and efficiency of the machine. In experimental measurements made in our prototype, we have an angular speed of 360.1 rpm (revolutions per minute) with an average temperature of 215.6 deg C camera hot (expansion cylinder) and 30 deg C cold source (compression cylinders) and torque generated by our machine is 0.388 Nm Our device is multi-fuel and can be used virtually any source of energy: gasoline, ethanol, methanol, natural gas, diesel, biogas, LPG and solar energy. The construction of this device allowed us to investigate the processes of transformation of energy: chemical, thermal, and mechanical and maximize efficiency of the Stirling engine. To complete the monitoring apparatus, use equipment such as notebook, digital tachometer and a data acquisition Agilent 34970A model. These devices were used in monitoring the angular velocity and

  7. A study on the application of CRUDTRAN code in primary systems of domestic pressurized heavy-water reactors for prediction of radiation source term

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jong Soon; Cho, Hoon Jo; Jung, Min Young; Lee, Sang Heon [Dept. of Nuclear Engineering, Chosun University, Gwangju (Korea, Republic of)

    2017-04-15

    The importance of developing a source-term assessment technology has been emphasized owing to the decommissioning of Kori nuclear power plant (NPP) Unit 1 and the increase of deteriorated NPPs. We analyzed the behavioral mechanism of corrosion products in the primary system of a pressurized heavy-water reactor-type NPP. In addition, to check the possibility of applying the CRUDTRAN code to a Canadian Deuterium Uranium Reactor (CANDU)-type NPP, the type was assessed using collected domestic onsite data. With the assessment results, it was possible to predict trends according to operating cycles. Values estimated using the code were similar to the measured values. The results of this study are expected to be used to manage the radiation exposures of operators in high-radiation areas and to predict decommissioning processes in the primary system.

  8. Primary energy sources for electricity supply in the FRG - demand and requirements as seen by the electricity supply industry

    International Nuclear Information System (INIS)

    Bierhoff, R.

    1977-01-01

    Starting from the present energy supply situation in the FRG, the attempt is made to elucidate basic tendencies for its development until 1990. The author pleads for the necessary growth by means of a series of theses. The supply with electric power being in the foreground can only be secured in the long run by means of greater utilization of coal and nuclear energy. Due to costs, other energy sources - playing a major role - will contribute less to the supply of electric power. (UA) [de

  9. THE DUST BUDGET OF THE SMALL MAGELLANIC CLOUD: ARE ASYMPTOTIC GIANT BRANCH STARS THE PRIMARY DUST SOURCE AT LOW METALLICITY?

    International Nuclear Information System (INIS)

    Boyer, M. L.; Gordon, K. D.; Meixner, M.; Sargent, B. A.; Srinivasan, S.; Riebel, D.; McDonald, I.; Van Loon, J. Th.; Clayton, G. C.; Sloan, G. C.

    2012-01-01

    We estimate the total dust input from the cool evolved stars in the Small Magellanic Cloud, using the 8 μm excess emission as a proxy for the dust-production rate (DPR). We find that asymptotic giant branch (AGB) and red supergiant (RSG) stars produce (8.6-9.5) × 10 –7 M ☉ yr –1 of dust, depending on the fraction of far-infrared sources that belong to the evolved star population (with 10%-50% uncertainty in individual DPRs). RSGs contribute the least ( –3 M ☉ of dust each, then the total SN dust input and AGB input are roughly equivalent. We consider several scenarios of SN dust production and destruction and find that the interstellar medium (ISM) dust can be accounted for solely by stellar sources if all SNe produce dust in the quantities seen around the dustiest examples and if most SNe explode in dense regions where much of the ISM dust is shielded from the shocks. We find that AGB stars contribute only 2.1% of the ISM dust. Without a net positive contribution from SNe to the dust budget, this suggests that dust must grow in the ISM or be formed by another unknown mechanism.

  10. Nutrient synchrony in preruminant calves

    NARCIS (Netherlands)

    Borne, van den J.J.G.C.

    2006-01-01

    In animal nutrition, the nutrient composition of the daily feed supply is composed to match the nutrient requirements for the desired performance. The time of nutrient availability within a day is usually considered not to affect the fate of nutrients. The aim of this thesis was to evaluate effects

  11. Food web interactions and nutrients dynamics in polyculture ponds

    NARCIS (Netherlands)

    Rahman, M.M.

    2006-01-01

    Artificial feed and fertilizers are the main sources of nutrients supporting fish growth in aquaculture ponds. The majority of the added nutrients are lost to the sediment, where they are no longer available for natural food production. By increasing resuspension of the sediment through the

  12. Evaluation of Wall Correction Factor of INER's Air-Kerma Primary Standard Chamber and Dose Variation by Source Displacement for HDR 192Ir Brachytherapy

    Directory of Open Access Journals (Sweden)

    J. H. Lee

    2013-01-01

    Full Text Available The aim of the present study was to estimate the wall effect of the self-made spherical graphite-walled cavity chamber with the Monte Carlo method for establishing the air-kerma primary standard of high-dose-rate (HDR 192Ir brachytherapy sources at the Institute of Nuclear Energy Research (INER, Taiwan. The Monte Carlo method established in this paper was also employed to respectively simulate wall correction factors of the 192Ir air-kerma standard chambers used at the National Institute of Standards and Technology (NIST, USA and the National Physical Laboratory (NPL, UK for comparisons and verification. The chamber wall correction calculation results will be incorporated into INER's HDR 192Ir primary standard in the future. For the brachytherapy treatment in the esophagus or in the bronchi, the position of the isotope may have displacement in the cavity. Thus the delivered dose would differ from the prescribed dose in the treatment plan. We also tried assessing dose distribution due to the position displacement of HDR 192Ir brachytherapy source in a phantom with a central cavity by the Monte Carlo method. The calculated results could offer a clinical reference for the brachytherapy within the human organs with cavity.

  13. Mass-Balance Constraints on Nutrient Cycling in Tropical Seagrass Beds

    NARCIS (Netherlands)

    Erftemeijer, P.L.A.; Middelburg, J.J.

    1995-01-01

    A relatively simple mass balance model is presented to study the cycling of nutrients (nitrogen and phosphorus) in tropical seagrass beds. The model is based on quantitative data on nutrient availability, seagrass primary production, community oxygen metabolism, seagrass tissue nutrient contents,

  14. Primary magmas and mantle sources of Emeishan basalts constrained from major element, trace element and Pb isotope compositions of olivine-hosted melt inclusions

    Science.gov (United States)

    Ren, Zhong-Yuan; Wu, Ya-Dong; Zhang, Le; Nichols, Alexander R. L.; Hong, Lu-Bing; Zhang, Yin-Hui; Zhang, Yan; Liu, Jian-Qiang; Xu, Yi-Gang

    2017-07-01

    Olivine-hosted melt inclusions within lava retain important information regarding the lava's primary magma compositions and mantle sources. Thus, they can be used to infer the nature of the mantle sources of large igneous provinces, which is still not well known and of the subject of debate. We have analysed the chemical compositions and Pb isotopic ratios of olivine-hosted melt inclusions in the Dali picrites, Emeishan Large Igneous Province (LIP), SW China. These are the first in-situ Pb isotope data measured for melt inclusions found in the Emeishan picrites and allow new constraints to be placed on the source lithology of the Emeishan LIP. The melt inclusions show chemical compositional variations, spanning low-, intermediate- and high-Ti compositions, while their host whole rocks are restricted to the intermediate-Ti compositions. Together with the relatively constant Pb isotope ratios of the melt inclusions, the compositional variations suggest that the low-, intermediate- and high-Ti melts were derived from compositionally similar sources. The geochemical characteristics of melt inclusions, their host olivines, and whole-rocks from the Emeishan LIP indicate that Ca, Al, Mn, Yb, and Lu behave compatibly, and Ti, Rb, Sr, Zr, and Nb behave incompatibly during partial melting, requiring a pyroxenite source for the Emeishin LIP. The wide range of Ti contents in the melt inclusions and whole-rocks of the Emeishan basalts reflects different degrees of partial melting in the pyroxenite source at different depths in the melting column. The Pb isotope compositions of the melt inclusions and the OIB-like trace element compositions of the Emeishan basalts imply that mixing of a recycled ancient oceanic crust (EM1-like) component with a peridotite component from the lower mantle (FOZO-like component) could have underwent solid-state reaction, producing a secondary pyroxenite source that was subsequently partially melted to form the basalts. This new model of pyroxenite

  15. THERMODYNAMIC INTERACTION OF THE PRIMARY PROTON BEAM WITH A MERCURY JET TARGET AT A NEUTRINO FACTORY SOURCE

    International Nuclear Information System (INIS)

    SIMOS, N.; LUDEWIG, H.; KIRK, H.; THIEBERGER, P.; MCDONALD, K.

    2001-01-01

    This paper addresses the thermodynamic interaction of an intense proton beam with the proposed mercury jet target at a neutrino factory or muon collider source, and the consequences of the generated pressure waves on the target integrity. Specifically, a 24 GeV proton beam with approximately 1.6e13 protons per pulse and a pulse length of 2 nanosec will interact with a 1 cm diameter mercury jet within a 20 Tesla magnetic field. In one option, a train of six such proton pulses is to be delivered on target within 2 microsec, in which case the state of the mercury jet following the interaction with each pulse is critical. Using the equation of state for mercury from the SESAME library, in combination with the energy deposition rates calculated the by the hadron interaction code MARS, the induced 3-D pressure field in the target is estimated. The consequent pressure wave propagation and attenuation in the mercury jet is calculated using an ANSYS code transient analysis, and the state of the mercury jet at the time of arrival of the subsequent pulse is assessed. The amplitude of the pressure wave reaching the nozzle that ejects the mercury jet into the magnetic field is estimated and the potential for mechanical damage is addressed

  16. Skeletal response to diet with soya bean seeds used as primary source of protein in growing broiler chickens.

    Science.gov (United States)

    Olkowski, B; Charuta, A; Radzki, R; Bieńko, M; Toczko, R

    2016-08-01

    The study was conducted using 120 commercial broiler chicks (Ross 308) randomly allocated to two experimental groups. The experimental diets, differing only in protein source, either solvent-extracted soya bean meal (SBM) or traditional (non-genetically modified) full-fat soya bean seeds (FFS), were prepared using practical corn-based formulation designed to meet nutritional requirements of broilers. Performance parameters were monitored weekly. Also, the subjects were evaluated daily for overt changes in skeletal anatomy and gait physiology. Randomly selected chickens from each group (seven males and seven females) were euthanized at 2, 3, 4 and 6 weeks of age, and bone specimens were collected for further study. Bone mineral density (BMD) and bone mineral content (BMC) were determined in tibiotarsal bones. Broilers fed FFS diet showed retarded growth rate and decreased feed intake (both p chickens from the FFS group in comparison with the SBM group. The chickens fed the FFS diet showed higher incidence of skeletal pathology including angular deformities and torticollis (both p chickens. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

  17. Periphytic biofilms: A promising nutrient utilization regulator in wetlands.

    Science.gov (United States)

    Wu, Yonghong; Liu, Junzhuo; Rene, Eldon R

    2018-01-01

    Low nutrient utilization efficiency in agricultural ecosystems is the main cause of nonpoint source (NPS) pollution. Therefore, novel approaches should be explored to improve nutrient utilization in these ecosystems. Periphytic biofilms composed of microalgae, bacteria and other microbial organisms are ubiquitous and form a 'third phase' in artificial wetlands such as paddy fields. Periphytic biofilms play critical roles in nutrient transformation between the overlying water and soil/sediment, however, their contributions to nutrient utilization improvement and NPS pollution control have been largely underestimated. This mini review summarizes the contributions of periphytic biofilms to nutrient transformation processes, including assimilating and storing bioavailable nitrogen and phosphorus, fixing nitrogen, and activating occluded phosphorus. Future research should focus on augmenting the nitrogen fixing, phosphate solubilizing and phosphatase producing microorganisms in periphytic biofilms to improve nutrient utilization and thereby reduce NPS pollution production in artificial and natural wetland ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Sewage discharges and nutrient levels in Marimba River, Zimbabwe ...

    African Journals Online (AJOL)

    Sewage discharges and nutrient levels in Marimba River, Zimbabwe. ... Population distribution, land-use, industrial activity, urban agricultural ... River, one of the major inflow rivers into the Lake Chivero, Harare city\\'s main water supply source.

  19. Production, partitioning and stoichiometry of organic matter under variable nutrient supply during mesocosm experiments in the tropical Pacific and Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    J. M. S. Franz

    2012-11-01

    Full Text Available Oxygen-deficient waters in the ocean, generally referred to as oxygen minimum zones (OMZ, are expected to expand as a consequence of global climate change. Poor oxygenation is promoting microbial loss of inorganic nitrogen (N and increasing release of sediment-bound phosphate (P into the water column. These intermediate water masses, nutrient-loaded but with an N deficit relative to the canonical N:P Redfield ratio of 16:1, are transported via coastal upwelling into the euphotic zone. To test the impact of nutrient supply and nutrient stoichiometry on production, partitioning and elemental composition of dissolved (DOC, DON, DOP and particulate (POC, PON, POP organic matter, three nutrient enrichment experiments were conducted with natural microbial communities in shipboard mesocosms, during research cruises in the tropical waters of the southeast Pacific and the northeast Atlantic. Maximum accumulation of POC and PON was observed under high N supply conditions, indicating that primary production was controlled by N availability. The stoichiometry of microbial biomass was unaffected by nutrient N:P supply during exponential growth under nutrient saturation, while it was highly variable under conditions of nutrient limitation and closely correlated to the N:P supply ratio, although PON:POP of accumulated biomass generally exceeded the supply ratio. Microbial N:P composition was constrained by a general lower limit of 5:1. Channelling of assimilated P into DOP appears to be the mechanism responsible for the consistent offset of cellular stoichiometry relative to inorganic nutrient supply and nutrient drawdown, as DOP build-up was observed to intensify under decreasing N:P supply. Low nutrient N:P conditions in coastal upwelling areas overlying O2-deficient waters seem to represent a net source for DOP, which may stimulate growth of diazotrophic phytoplankton. These results demonstrate that microbial nutrient assimilation and

  20. Nutrient mitigation in a temporary river basin.

    Science.gov (United States)

    Tzoraki, Ourania; Nikolaidis, Nikolaos P; Cooper, David; Kassotaki, Elissavet

    2014-04-01

    We estimate the nutrient budget in a temporary Mediterranean river basin. We use field monitoring and modelling tools to estimate nutrient sources and transfer in both high and low flow conditions. Inverse modelling by the help of PHREEQC model validated the hypothesis of a losing stream during the dry period. Soil and Water Assessment Tool model captured the water quality of the basin. The 'total daily maximum load' approach is used to estimate the nutrient flux status by flow class, indicating that almost 60% of the river network fails to meet nitrogen criteria and 50% phosphate criteria. We recommend that existing well-documented remediation measures such as reforestation of the riparian area or composting of food process biosolids should be implemented to achieve load reduction in close conjunction with social needs.

  1. Late gestational nutrient restriction

    DEFF Research Database (Denmark)

    Tygesen, Malin Plumhoff; Nielsen, Mette Olaf; Nørgaard, Peder

    2008-01-01

    We investigated the effect of 50% nutrient restriction during the last 6 weeks of gestation on twin-pregnant ewes' plasma glucose, non-esterified fatty acid, ß-hydroxybutyrate, insulin, IGF-1 and leptin concentrations and the effects on lamb birth weight and ewes' lactation performance. Plasma...

  2. Coupling nutrient uptake and energy flow in headwater streams

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, Patrick J [ORNL; Fellows, Christine [Griffith University, Nathan, Queensland, Australia; Valett, H. Maurice [Virginia Polytechnic Institute and State University (Virginia Tech); Dahm, Cliff [University of New Mexico, Albuquerque; Thomas, Steve [University of Nebraska

    2006-08-01

    Nutrient cycling and energy flow in ecosystems are tightly linked through the metabolic processes of organisms. Greater uptake of inorganic nutrients is expected to be associated with higher rates of metabolism [gross primary production (GPP) and respiration (R)], due to assimilatory demand of both autotrophs and heterotrophs. However, relationships between uptake and metabolism should vary with the relative contribution of autochthonous and allochthonous sources of organic matter. To investigate the relationship between metabolism and nutrient uptake, we used whole-stream and benthic chamber methods to measure rates of nitrate-nitrogen (NO{sub 3}-N) uptake and metabolism in four headwater streams chosen to span a range of light availability and therefore differing rates of GPP and contributions of autochthonous carbon. We coupled whole-stream metabolism with measures of NO{sub 3}-N uptake conducted repeatedly over the same stream reach during both day and night, as well as incubating benthic sediments under both light and dark conditions. NO{sub 3}-N uptake was generally greater in daylight compared to dark conditions, and although day-night differences in whole-stream uptake were not significant, light-dark differences in benthic chambers were significant at three of the four sites. Estimates of N demand indicated that assimilation by photoautotrophs could account for the majority of NO{sub 3}-N uptake at the two sites with relatively open canopies. Contrary to expectations, photoautotrophs contributed substantially to NO{sub 3}-N uptake even at the two closed-canopy sites, which had low values of GPP/R and relied heavily on allochthonous carbon to fuel R.

  3. Impact of Temperature and Nutrients on Carbon: Nutrient Tissue Stoichiometry of Submerged Aquatic Plants: An Experiment and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Mandy Velthuis

    2017-05-01

    Full Text Available Human activity is currently changing our environment rapidly, with predicted temperature increases of 1–5°C over the coming century and increased nitrogen and phosphorus inputs in aquatic ecosystems. In the shallow parts of these ecosystems, submerged aquatic plants enhance water clarity by resource competition with phytoplankton, provide habitat, and serve as a food source for other organisms. The carbon:nutrient stoichiometry of submerged aquatic plants can be affected by changes in both temperature and nutrient availability. We hypothesized that elevated temperature leads to higher carbon:nutrient ratios through enhanced nutrient-use efficiency, while nutrient addition leads to lower carbon:nutrient ratios by the luxurious uptake of nutrients. We addressed these hypotheses with an experimental and a meta-analytical approach. We performed a full-factorial microcosm experiment with the freshwater plant Elodea nuttallii grown at 10, 15, 20, and 25°C on sediment consisting of pond soil/sand mixtures with 100, 50, 25, and 12.5% pond soil. To address the effect of climatic warming and nutrient addition on the carbon:nutrient stoichiometry of submerged freshwater and marine plants we performed a meta-analysis on experimental studies that elevated temperature and/or added nutrients (nitrogen and phosphorus. In the microcosm experiment, C:N ratios of Elodea nuttallii decreased with increasing temperature, and this effect was most pronounced at intermediate nutrient availability. Furthermore, higher nutrient availability led to decreased aboveground C:P ratios. In the meta-analysis, nutrient addition led to a 25, 22, and 16% reduction in aboveground C:N and C:P ratios and belowground C:N ratios, accompanied with increased N content. No consistent effect of elevated temperature on plant stoichiometry could be observed, as very few studies were found on this topic and contrasting results were reported. We conclude that while nutrient addition

  4. Agro-industrial by-products as roughage source for beef cattle: Chemical composition, nutrient digestibility and energy values of ensiled sweet corn cob and husk with different levels of Ipil – Ipil leaves.

    Directory of Open Access Journals (Sweden)

    Sompong Sruamsiri

    2007-07-01

    Full Text Available This experiment was carried out to determine the nutritive value of agro-industrial by-products and nutrient digestibility of ensiled sweet corn cob and husk with different levels of Ipil - Ipil leaves (Leucaena leucocephala. Four native cattle were assigned by Latin Square Design to receive all dietary treatments in four experimental periods i.e. ensiled sweet corn cob and husk (ESCH, ensiled sweet corn cob and husk + 10 % Ipil - Ipil leaves (ESCH + 10% IL, ensiled sweet corn cob and husk + 20% Ipil - Ipil leaves (ESCH + 20% IL and ensiled sweet corn cob and husk + 30% Ipil - Ipil leaves (ESCH + 30% IL, respectively. Total collection method was used to determine the digestibility coefficients. Results showed that digestibility coefficients in ESCH were low (P>0.05 in all the nutrients. Supplementation of Ipil - Ipil leaves in ESCH increased digestibility coefficients. Total digestible nutrients (TDN and digestible energy were higher in the silages supplemented with Ipil - Ipil leaves. Average TDN contents of ESCH, ESCH + 10% IL, 20% IL and 30% IL were 62.78 + 6.14, 70.41 + 4.04, 72.73 + 2.78 and 63.07 + 4.06 %DM, respectively.

  5. Nutrient composition of important fish species in Bangladesh and potential contribution to recommended nutrient intakes

    DEFF Research Database (Denmark)

    Bogard, Jessica R.; Thilsted, Shakuntala H.; Marks, Geoffrey C.

    2015-01-01

    Fish, in Bangladesh where malnutrition remains a significant development