Science.gov

Sample records for nutrientes da silagem

  1. Ocean nutrients

    NASA Astrophysics Data System (ADS)

    Boyd, Philip W.; Hurd, Catriona L.

    Nutrients provide the chemical life-support system for phytoplankton in the ocean. Together with the carbon fixed during photosynthesis, nutrients provide the other elements, such as N and P, needed to synthesize macromolecules to build cellular constituents such as ribosomes. The makeup of these various biochemicals, such as proteins, pigments, and nucleic acids, together determine the elemental stoichiometry of an individual phytoplankton cell. The stoichiometry of different phytoplankton species or groups will vary depending on the proportions of distinct cellular machinery, such as for growth or resource acquisition, they require for their life strategies. The uptake of nutrients by phytoplankton helps to set the primary productivity, and drives the biological pump, of the global ocean. In the case of nitrogen, the supply of nutrients is categorized as either new or regenerated. The supply of new nitrogen, such as nitrate upwelled from the ocean' interior or biological nitrogen fixation, is equal to the vertical export of particular organic matter from the upper ocean on a timescale of years. Nutrients such as silica can also play a structural role in some phytoplankton groups, such as diatoms, where they are used to synthesize a siliceous frustule that offers some mechanical protection from grazers. In this chapter, we also explore nutrient uptake kinetics, patterns in nutrient distributions in space and time, the biogeochemical cycle of nitrogen, the atmospheric supply of nutrients, departures from the Redfield ratio, and whether nutrient distributions and cycling will be altered in the future

  2. Nutrient management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nutrient management has been defined as “the science and art directed to link soil, crop, weather and hydrologic factors with cultural, irrigation and soil and water conservation practices to achieve the goals of optimizing nutrient use efficiency, yields, crop quality, and economic returns, while r...

  3. Available nutrients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar technology may contribute to the recovery and recycling of plant nutrients and thus add a fertilizer value to the biochar. Total nutrient content in biochars varies greatly and is mainly dependent on feedstock elemental composition and to a lesser extent on pyrolysis conditions. Availability...

  4. Key Nutrients.

    ERIC Educational Resources Information Center

    Federal Extension Service (USDA), Washington, DC.

    Lessons written to help trainer agents prepare aides for work with families in the Food and Nutrition Program are presented in this booklet. The key nutrients discussed in the 10 lessons are protein, carbohydrates, fat, calcium, iron, iodine, and Vitamins A, B, C, and D. the format of each lesson is as follows: Purpose, Presentation, Application…

  5. Root Nutrient Foraging1

    PubMed Central

    Giehl, Ricardo F.H.; von Wirén, Nicolaus

    2014-01-01

    During a plant's lifecycle, the availability of nutrients in the soil is mostly heterogeneous in space and time. Plants are able to adapt to nutrient shortage or localized nutrient availability by altering their root system architecture to efficiently explore soil zones containing the limited nutrient. It has been shown that the deficiency of different nutrients induces root architectural and morphological changes that are, at least to some extent, nutrient specific. Here, we highlight what is known about the importance of individual root system components for nutrient acquisition and how developmental and physiological responses can be coupled to increase nutrient foraging by roots. In addition, we review prominent molecular mechanisms involved in altering the root system in response to local nutrient availability or to the plant's nutritional status. PMID:25082891

  6. Nutrient Density Scores.

    ERIC Educational Resources Information Center

    Dickinson, Annette; Thompson, William T.

    1979-01-01

    Announces a nutrient density food scoring system called the Index of Nutritional Quality (INQ). It expresses the ratio between the percent RDA of a nutrient and the percent daily allowance of calories in a food. (Author/SA)

  7. Nutrient Database improvement project: Separable components and proximate composition of retail cuts from the beef chuck

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to provide updated information on the separable components, cooking yields, and nutrient values of retail cuts from the beef chuck. Ultimately, these data will be used in the United States Department of Agriculture (USDA) Nutrient Data Laboratory’s (NDL) National Nutrient Da...

  8. Duodenal luminal nutrient sensing

    PubMed Central

    Rønnestad, Ivar; Akiba, Yasutada; Kaji, Izumi; Kaunitz, Jonathan D

    2016-01-01

    The gastrointestinal mucosa is exposed to numerous chemical substances and microorganisms, including macronutrients, micronutrients, bacteria, endogenous ions, and proteins. The regulation of mucosal protection, digestion, absorption and motility is signaled in part by luminal solutes. Therefore, luminal chemosensing is an important mechanism enabling the mucosa to monitor luminal conditions, such as pH, ion concentrations, nutrient quantity, and microflora. The duodenal mucosa shares luminal nutrient receptors with lingual taste receptors in order to detect the five basic tastes, in addition to essential nutrients, and unwanted chemicals. The recent ‘de-orphanization’ of nutrient sensing G protein-coupled receptors provides an essential component of the mechanism by which the mucosa senses luminal nutrients. In this review, we will update the mechanisms of and underlying physiological and pathological roles in luminal nutrient sensing, with a main focus on the duodenal mucosa. PMID:25113991

  9. Nutrient Control Design Manual

    EPA Science Inventory

    The Nutrient Control Design Manual will present an extensive state-of-the-technology review of the engineering design and operation of nitrogen and phosphorous control technologies and techniques applied at municipal wastewater treatment plants (WWTPs). This manual will present ...

  10. Nutrient Control Seminars

    EPA Science Inventory

    These Nutrient Control Seminars will present an extensive state-of-the-technology review of the engineering design and operation of nitrogen and phosphorous control technologies and techniques applied at municipal wastewater treatment plants (WWTPs). These seminars will present ...

  11. Integrated Urban Nutrient Management

    NASA Astrophysics Data System (ADS)

    Nhapi, I.; Veenstra, S.; Siebel, M. A.; Gijzen, H. J.

    Most cities, especially from the developing countries, are facing serious problems with the management of nutrients, necessitating an urgent review of current waste management systems. Whilst highly efficient technologies are available, the inclusion of these in a well-thought out and systematic approach is necessary to contain the nutrient influxes and outfluxes from towns. Five intervention measures are proposed in this paper. The first is to manage the use and generation of nutrients by drastically minimising water consumption and employing other cleaner production approaches. The second deals with the optimal reuse of nutrients and water at the smallest possible level, like at the household and on-plot level. The second option is to covert the waste into something useful for reuse, and, where not possible, to something which is envi- ronmentally neutral. This involves treatment, but applying technologies that makes the best use of side products via reuse. Where the first three options will have failed, two least preferred options could be used. Waste can be dispersed or diluted to enhance self-purification capacities of downstream water bodies. The last option is to store the wastewater for some parts of the year when there is water shortage to allow for polishing during the standing period. The success of urban nutrient planning requires an integrated approach, proving specific solutions to specific situations. This, in turn, requires appropriate institutional responses.

  12. Nutrient Requirements in Adolescence.

    ERIC Educational Resources Information Center

    McKigney, John I,; Munro, Hamish N.

    It is important to understand the nutrient requirements and the significance of nutrition both in pubescence and adolescence. The pubescent growth spurt is characterized by an increase in body size and a change in proportion of different tissues. Both of these factors are of great nutritional importance, since there is reason to believe that the…

  13. Estimation of stream nutrient uptake from nutrient addition experiments

    SciTech Connect

    Payn, Robert

    2005-09-01

    Nutrient uptake in streams is often quantified by determining nutrient uptake length. However, current methods for measuring nutrient uptake length are often impractical, expensive, or demonstrably incorrect. We have developed a new method to estimate ambient nutrient uptake lengths using field experiments involving several levels of nutrient addition. Data analysis involves plotting nutrient addition uptake lengths versus added concentration and extrapolating to the negative ambient concentration. This method is relatively easy, inexpensive, and based on sound theoretical development. It is more accurate than the commonly used method involving a single nutrient addition. The utility of the method is supported by field studies directly comparing our new method with isotopic tracer methods for determining uptake lengths of phosphorus, ammonium, and nitrate. Our method also provides parameters for comparing potential nutrient limitation among streams.

  14. Harmonization of nutrient intake values.

    PubMed

    King, Janet C; Garza, Cutberto

    2007-03-01

    The conceptual framework for the various NIVs is depicted in figure 1 along with the methodological approaches and applications. The NIVs consist of two values derived from a statistical evaluation of data on nutrient requirements, the average nutrient requirement (ANR), or nutrient toxicities, the upper nutrient level (UNL). The individual nutrient levelx (INLx) is derived from the distribution of average nutrient requirements. The percentile chosen is often 98%, which is equivalent to 2 SD above the mean requirement. Concepts underlying the NIVs include criteria for establishing a nutrient requirement, e.g., ferritin stores, nitrogen balance, or serum vitamin C. Once the requirement for the absorbed nutrient is determined, it may be necessary to adjust the value for food sources, i.e., bioavailability, or host factors, such as the effect of infection on nutrient utilization. Other concepts that committees may want to consider when establishing NIVs include the effects of genetic variation on nutrient requirements and the role of the nutrient in preventing long-term disease. Two fundamental uses of NIVs are for assessing the adequacy of nutrient intakes and for planning diets for individuals and populations. Establishing the NIV using the statistical framework proposed in this report improves the efficacy of the values for identifying risks of nutrient deficiency or excess among individuals and populations. NIVs also are applied to a number of aspects of food and nutrition policy. Some examples include regulatory issues and trade, labeling, planning programs for alleviating public health nutrition problems, food fortification, and dietary guidance.

  15. Nutrients in the nexus

    USGS Publications Warehouse

    Davidson, Eric A.; Niphong, Rachel; Ferguson, Richard B.; Palm, Cheryl; Osmond, Deanna L.; Baron, Jill S.

    2016-01-01

    Synthetic nitrogen (N) fertilizer has enabled modern agriculture to greatly improve human nutrition during the twentieth century, but it has also created unintended human health and environmental pollution challenges for the twenty-first century. Averaged globally, about half of the fertilizer-N applied to farms is removed with the crops, while the other half remains in the soil or is lost from farmers’ fields, resulting in water and air pollution. As human population continues to grow and food security improves in the developing world, the dual development goals of producing more nutritious food with low pollution will require both technological and socio-economic innovations in agriculture. Two case studies presented here, one in sub-Saharan Africa and the other in Midwestern United States, demonstrate how management of nutrients, water, and energy is inextricably linked in both small-scale and large-scale food production, and that science-based solutions to improve the efficiency of nutrient use can optimize food production while minimizing pollution. To achieve the needed large increases in nutrient use efficiency, however, technological developments must be accompanied by policies that recognize the complex economic and social factors affecting farmer decision-making and national policy priorities. Farmers need access to affordable nutrient supplies and support information, and the costs of improving efficiencies and avoiding pollution may need to be shared by society through innovative policies. Success will require interdisciplinary partnerships across public and private sectors, including farmers, private sector crop advisors, commodity supply chains, government agencies, university research and extension, and consumers.

  16. Bone nutrients for vegetarians.

    PubMed

    Mangels, Ann Reed

    2014-07-01

    The process of bone mineralization and resorption is complex and is affected by numerous factors, including dietary constituents. Although some dietary factors involved in bone health, such as calcium and vitamin D, are typically associated with dairy products, plant-based sources of these nutrients also supply other key nutrients involved in bone maintenance. Some research suggests that vegetarian diets, especially vegan diets, are associated with lower bone mineral density (BMD), but this does not appear to be clinically significant. Vegan diets are not associated with an increased fracture risk if calcium intake is adequate. Dietary factors in plant-based diets that support the development and maintenance of bone mass include calcium, vitamin D, protein, potassium, and soy isoflavones. Other factors present in plant-based diets such as oxalic acid and phytic acid can potentially interfere with absorption and retention of calcium and thereby have a negative effect on BMD. Impaired vitamin B-12 status also negatively affects BMD. The role of protein in calcium balance is multifaceted. Overall, calcium and protein intakes in accord with Dietary Reference Intakes are recommended for vegetarians, including vegans. Fortified foods are often helpful in meeting recommendations for calcium and vitamin D. Plant-based diets can provide adequate amounts of key nutrients for bone health. PMID:24898231

  17. Bone nutrients for vegetarians.

    PubMed

    Mangels, Ann Reed

    2014-07-01

    The process of bone mineralization and resorption is complex and is affected by numerous factors, including dietary constituents. Although some dietary factors involved in bone health, such as calcium and vitamin D, are typically associated with dairy products, plant-based sources of these nutrients also supply other key nutrients involved in bone maintenance. Some research suggests that vegetarian diets, especially vegan diets, are associated with lower bone mineral density (BMD), but this does not appear to be clinically significant. Vegan diets are not associated with an increased fracture risk if calcium intake is adequate. Dietary factors in plant-based diets that support the development and maintenance of bone mass include calcium, vitamin D, protein, potassium, and soy isoflavones. Other factors present in plant-based diets such as oxalic acid and phytic acid can potentially interfere with absorption and retention of calcium and thereby have a negative effect on BMD. Impaired vitamin B-12 status also negatively affects BMD. The role of protein in calcium balance is multifaceted. Overall, calcium and protein intakes in accord with Dietary Reference Intakes are recommended for vegetarians, including vegans. Fortified foods are often helpful in meeting recommendations for calcium and vitamin D. Plant-based diets can provide adequate amounts of key nutrients for bone health.

  18. Trends in nutrients

    USGS Publications Warehouse

    Heathwaite, A.L.; Johnes, P.J.; Peters, N.E.

    1996-01-01

    The roles of nitrogen (N) and phosphorus (P) as key nutrients determining the trophic status of water bodies are examined, and evidence reviewed for trends in concentrations of N and P species which occur in freshwaters, primarily in northern temperate environments. Data are reported for water bodies undergoing eutrophication and acidification, especially water bodies receiving increased nitrogen inputs through the atmospheric deposition of nitrogen oxides (NOx). Nutrient loading on groundwaters and surface freshwaters is assessed with respect to causes and rates of (change, relative rates of change for N and P, and implications of change for the future management of lakes, rivers and groundwaters. In particular, the nature and emphasis of studies for N species and P fractions in lakes versus rivers and groundwaters are contrasted. This review paper primarily focuses on results from North America and Europe, particularly for the UK where a wide range of data sets exists. Few nutrient loading data have been published on water bodies in less developed countries; however, some of the available data are presented to provide a global perspective. In general, N and P concentrations have increased dramatically (>20 times background concentrations) in many areas and causes vary considerably, ranging from urbanization to changes in agricultural practices.

  19. National Nutrient Database for Standard Reference - Find Nutrient Value of Common Foods by Nutrient

    MedlinePlus

    ... Department of Agriculture Agricultural Research Service National Nutrient Database for Standard Reference Release 28 NDL Home Food ... Sort by: Measure by: * required field ​ National Nutrient Database for Standard Reference Release 28 slightly revised May, ...

  20. Siletz River nutrients: Effects of biosolids application

    EPA Science Inventory

    Stream water nutrients were measured in the Siletz River, Oregon, with the goal of comparing dissolved nutrient concentrations, primarily the nitrogenous nutrients nitrate and ammonium, with previously collected data for the Yaquina and Alsea Rivers for the nutrient criteria prog...

  1. Nutrient dynamics: Chapter 3

    USGS Publications Warehouse

    Likens, Gene E.; LaBaugh, James W.; Buso, Donald C.; Bade, Darren; Winter, Thomas C.; Likens, Gene E.

    2009-01-01

    This chapter focuses on the variability and trends in chemical concentrations and fluxes at Mirror Lake during the period 1981–2000. It examines the water and chemical budgets of Mirror Lake to identify and understand better long-term trends in the chemical characteristics of the lake. It also identifies the causes of changes in nutrient concentrations and examines the contribution of hydrologic pathways to the contamination of Mirror Lake by road salt. The role of groundwater and precipitation on water and chemical budgets of the lake are also examined.

  2. Neuroelectric assessment of nutrient intake.

    PubMed

    Hoffman, L D; Friedmann, A; Saltman, P; Polich, J

    1999-05-01

    Electroencephalographic (EEG) activity and auditory event-related brain potentials (ERPs) were assessed in two groups (n = 12 each) of subjects. The 'food-nutrient' group had fasted from the night before and consumed a 500 cal nutrient drink; the 'control' group consumed breakfast but did not consume any nutrients during the recordings. All subjects were assessed every 15 min for six trial blocks at the same time of day, with the fast/nutrient group measured initially before and after consuming the nutrient drink. No effects of the nutrient drink were obtained on the post-stimulus EEG spectral power or mean frequency measures. However, the fast/nutrient group demonstrated less delta, theta, and alpha-1 power than the no-fast/control group. Increases in spectral power were generally observed across trial blocks especially for the alpha and beta bands, and are consistent with increases in arousal level. P300 amplitude was unaffected by the nutrient consumption, but target stimulus N100 amplitude was smaller for the food-nutrient compared to the control group. Taken together, the results suggest that nutrient consumption does not directly affect EEG or cognitive ERP measures.

  3. WERF Nutrient Challenge investigates limits of nutrient removal technologies.

    PubMed

    Neethling, J B; Clark, D; Pramanik, A; Stensel, H D; Sandino, J; Tsuchihashi, R

    2010-01-01

    The WERF Nutrient Challenge is a multi-year collaborative research initiative established in 2007 to develop and provide current information about wastewater treatment nutrients (specifically nitrogen and phosphorus in wastewater), their characteristics, and bioavailability in aquatic environments to help regulators make informed decisions. The Nutrient Challenge will also provide data on nutrient removal so that treatment facilities can select sustainable, cost-effective methods and technologies to meet permit limits. To meet these goals, the Nutrient Challenge has teamed with a wide array of utilities, agencies, consultants, universities and other researchers and practitioners to collaborate on projects that advance these goals. The Nutrient Challenge is focusing on a different approach to collaborating and leveraging resources (financial and intellectual) on research projects by targeting existing projects and research that correspond with its goals and funding those aspects that the Nutrient Challenge identified as a priority. Because the Nutrient Challenge is focused on collaboration, outreach is an absolutely necessary component of its effectiveness. Through workshops, webinars, a web portal and online compendium, published papers, and conference lectures, the Nutrient Challenge is both presenting important new information, and soliciting new partnerships.

  4. Nutrient Sensing Mechanisms and Pathways

    PubMed Central

    Efeyan, Alejo; Comb, William C.; Sabatini, David M.

    2015-01-01

    PREFACE The ability to sense and respond to fluctuations in environmental nutrient levels is a requisite for life. Nutrient scarcity is a selective pressure that has shaped the evolution of most cellular processes. Different pathways that detect intracellular and extracellular levels of sugars, amino acids and lipids, and surrogate metabolites, are then integrated and coordinated at the organismal level via hormonal signals. During food abundance, nutrient sensing pathways engage anabolism and storage, and scarcity triggers homeostatic mechanisms, like the mobilization of internal stores through mechanisms such as autophagy. Nutrient sensing pathways are commonly deregulated in human metabolic diseases. PMID:25592535

  5. Intestinal sensing of nutrients.

    PubMed

    Tolhurst, Gwen; Reimann, Frank; Gribble, Fiona M

    2012-01-01

    Ingestion of a meal triggers a range of physiological responses both within and outside the gut, and results in the remote modulation of appetite and glucose homeostasis. Luminal contents are sensed by specialised chemosensitive cells scattered throughout the intestinal epithelium. These enteroendocrine and tuft cells make direct contact with the gut lumen and release a range of chemical mediators, which can either act in a paracrine fashion interacting with neighbouring cells and nerve endings or as classical circulating hormones. At the molecular level, the chemosensory machinery involves multiple and complex signalling pathways including activation of G-protein-coupled receptors and solute carrier transporters. This chapter will discuss our current knowledge of the molecular mechanisms underlying intestinal chemosensation with a particular focus on the relatively well-characterised nutrient-triggered secretion from the enteroendocrine system. PMID:22249821

  6. Nutrient Cycling Study

    SciTech Connect

    Peter A. Pryfogle

    2005-09-01

    The particular goal of this study is to develop measurement techniques for understanding how consortia of organisms from geothermal facilities utilize sulfur and iron for metabolic activity; and in turn, what role that activity plays in initiating or promoting the development of a biofilm on plant substrates. Sulfur cycling is of interest because sulfur is produced in the resource. Iron is found in some of the steel formulations used in plant components and is also added as chemical treatment for reducing sulfide emissions from the plants. This report describes the set-up and operation of a bioreactor for evaluating the response of colonies of geothermal organisms to changes in nutrient and environmental conditions. Data from initial experiments are presented and plans for future testing is discussed.

  7. Nutrients and neurodevelopment: lipids.

    PubMed

    González, Horacio F; Visentin, Silvana

    2016-10-01

    Nutrients, lipids in particular, make up the central nervous system structure and play major functional roles: they stimulate development, migration, and nerve cell differentiation. They are part of gray matter, white matter, nerve nuclei, and synaptogenesis. Breast milk contains lipids which are crucial for infant brain development. The lipid profile of breast milk was used as a guideline for the development of breast milk substitutes. However, to date, no substitute has matched it. Complementary feeding should include docosahexaenoic acid, arachidonic acid, other polyunsaturated fatty acids, saturated fatty acids, and complex lipids found in milk fat. The lipid composition of breast milk depends on maternal intake and nutritional status during pregnancy and breast-feeding. It has a great impact on development. Our goal is to review scientific literature regarding the role of lipids on infant brain development and the importance of breast milk lipid composition, maternal diet, and complementary feeding. PMID:27606648

  8. Nutrients and neurodevelopment: lipids.

    PubMed

    González, Horacio F; Visentin, Silvana

    2016-10-01

    Nutrients, lipids in particular, make up the central nervous system structure and play major functional roles: they stimulate development, migration, and nerve cell differentiation. They are part of gray matter, white matter, nerve nuclei, and synaptogenesis. Breast milk contains lipids which are crucial for infant brain development. The lipid profile of breast milk was used as a guideline for the development of breast milk substitutes. However, to date, no substitute has matched it. Complementary feeding should include docosahexaenoic acid, arachidonic acid, other polyunsaturated fatty acids, saturated fatty acids, and complex lipids found in milk fat. The lipid composition of breast milk depends on maternal intake and nutritional status during pregnancy and breast-feeding. It has a great impact on development. Our goal is to review scientific literature regarding the role of lipids on infant brain development and the importance of breast milk lipid composition, maternal diet, and complementary feeding.

  9. Nutrient loading alters the performance of key nutrient exchange mutualisms.

    PubMed

    Shantz, Andrew A; Lemoine, Nathan P; Burkepile, Deron E

    2016-01-01

    Nutrient exchange mutualisms between phototrophs and heterotrophs, such as plants and mycorrhizal fungi or symbiotic algae and corals, underpin the functioning of many ecosystems. These relationships structure communities, promote biodiversity and help maintain food security. Nutrient loading may destabilise these mutualisms by altering the costs and benefits each partner incurs from interacting. Using meta-analyses, we show a near ubiquitous decoupling in mutualism performance across terrestrial and marine environments in which phototrophs benefit from enrichment at the expense of their heterotrophic partners. Importantly, heterotroph identity, their dependence on phototroph-derived C and the type of nutrient enrichment (e.g. nitrogen vs. phosphorus) mediated the responses of different mutualisms to enrichment. Nutrient-driven changes in mutualism performance may alter community organisation and ecosystem processes and increase costs of food production. Consequently, the decoupling of nutrient exchange mutualisms via alterations of the world's nitrogen and phosphorus cycles may represent an emerging threat of global change. PMID:26549314

  10. Nutrient availability in rangeland soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil nutrient availability is a major factor influencing plant community composition and susceptibility to invasion by exotic plants. We used resin capsules to integrate, over time, soil nutrient availability at sagebrush-grassland elevation transects in the east Tintic range of Utah and in the Shos...

  11. Nutrient Removal in Wastewater Treatment

    ERIC Educational Resources Information Center

    Shah, Kanti L.

    1973-01-01

    Discusses the sources and effects of nutrients in wastewater, and the methods of their removal in wastewater treatment. In order to conserve water resources and eliminate the cost of nutrient removal, treated effluent should be used wherever possible for irrigation, since it contains all the ingredients for proper plant growth. (JR)

  12. Nutrient Needs of Young Athletes.

    ERIC Educational Resources Information Center

    Willenberg, Barbara; Hemmelgarn, Melinda

    1991-01-01

    Explains the nutritional requirements of children and adolescents, and the physiological roles of the major nutrients. Details the nutrient needs of young athletes, including pre- and postgame meals and fluid replacement. Discusses eating disorders and obesity. Advocates a diet rich in complex carbohydrates. (BC)

  13. Use of Select Nutrients to Foster Wellness.

    ERIC Educational Resources Information Center

    Cassel, Russell N.

    1987-01-01

    Discusses how to be healthy through one's diet. Lists 20 nutrients necessary for one's well being and explains role of each nutrient. Describes how nutrients complement one another and asserts that the right combination of nutrients can sometimes substitute for medication. Also lists 20 diagnostic categories of problems and suggests nutrients to…

  14. Energy and Nutrient Intake Monitoring

    NASA Technical Reports Server (NTRS)

    Luckey, T. D.; Venugopal, B.; Hutcheson, D. P.

    1975-01-01

    A passive system to determine the in-flight intake of nutrients is developed. Nonabsorbed markers placed in all foods in proportion to the nutrients selected for study are analyzed by neutron activation analysis. Fecal analysis for each market indicates how much of the nutrients were eaten and apparent digestibility. Results of feasibility tests in rats, mice, and monkeys indicate the diurnal variation of several markers, the transit time for markers in the alimentary tract, the recovery of several markers, and satisfactory use of selected markers to provide indirect measurement of apparent digestibility. Recommendations are provided for human feasibility studies.

  15. Octopamine connects nutrient cues to lipid metabolism upon nutrient deprivation

    PubMed Central

    Tao, Jun; Ma, Yi-Cheng; Yang, Zhong-Shan; Zou, Cheng-Gang; Zhang, Ke-Qin

    2016-01-01

    Starvation is probably the most common stressful situation in nature. In vertebrates, elevation of the biogenic amine norepinephrine levels is common during starvation. However, the precise role of norepinephrine in nutrient deprivation remains largely unknown. We report that in the free-living nematode Caenorhabditis elegans, up-regulation of the biosynthesis of octopamine, the invertebrate counterpart of norepinephrine, serves as a mechanism to adapt to starvation. During nutrient deprivation, the nuclear receptor DAF-12, known to sense nutritional cues, up-regulates the expression of tbh-1 that encodes tyramine β-hydroxylase, a key enzyme for octopamine biosynthesis, in the RIC neurons. Octopamine induces the expression of the lipase gene lips-6 via its receptor SER-3 in the intestine. LIPS-6, in turn, elicits lipid mobilization. Our findings reveal that octopamine acts as an endocrine regulator linking nutrient cues to lipolysis to maintain energy homeostasis, and suggest that such a mechanism may be evolutionally conserved in diverse organisms. PMID:27386520

  16. TOR Signaling and Nutrient Sensing.

    PubMed

    Dobrenel, Thomas; Caldana, Camila; Hanson, Johannes; Robaglia, Christophe; Vincentz, Michel; Veit, Bruce; Meyer, Christian

    2016-04-29

    All living organisms rely on nutrients to sustain cell metabolism and energy production, which in turn need to be adjusted based on available resources. The evolutionarily conserved target of rapamycin (TOR) protein kinase is a central regulatory hub that connects environmental information about the quantity and quality of nutrients to developmental and metabolic processes in order to maintain cellular homeostasis. TOR is activated by both nitrogen and carbon metabolites and promotes energy-consuming processes such as cell division, mRNA translation, and anabolism in times of abundance while repressing nutrient remobilization through autophagy. In animals and yeasts, TOR acts antagonistically to the starvation-induced AMP-activated kinase (AMPK)/sucrose nonfermenting 1 (Snf1) kinase, called Snf1-related kinase 1 (SnRK1) in plants. This review summarizes the immense knowledge on the relationship between TOR signaling and nutrients in nonphotosynthetic organisms and presents recent findings in plants that illuminate the crucial role of this pathway in conveying nutrient-derived signals and regulating many aspects of metabolism and growth. PMID:26905651

  17. TOR Signaling and Nutrient Sensing.

    PubMed

    Dobrenel, Thomas; Caldana, Camila; Hanson, Johannes; Robaglia, Christophe; Vincentz, Michel; Veit, Bruce; Meyer, Christian

    2016-04-29

    All living organisms rely on nutrients to sustain cell metabolism and energy production, which in turn need to be adjusted based on available resources. The evolutionarily conserved target of rapamycin (TOR) protein kinase is a central regulatory hub that connects environmental information about the quantity and quality of nutrients to developmental and metabolic processes in order to maintain cellular homeostasis. TOR is activated by both nitrogen and carbon metabolites and promotes energy-consuming processes such as cell division, mRNA translation, and anabolism in times of abundance while repressing nutrient remobilization through autophagy. In animals and yeasts, TOR acts antagonistically to the starvation-induced AMP-activated kinase (AMPK)/sucrose nonfermenting 1 (Snf1) kinase, called Snf1-related kinase 1 (SnRK1) in plants. This review summarizes the immense knowledge on the relationship between TOR signaling and nutrients in nonphotosynthetic organisms and presents recent findings in plants that illuminate the crucial role of this pathway in conveying nutrient-derived signals and regulating many aspects of metabolism and growth.

  18. Programming placental nutrient transport capacity

    PubMed Central

    Fowden, A L; Ward, J W; Wooding, F P B; Forhead, A J; Constancia, M

    2006-01-01

    Many animal studies and human epidemiological findings have shown that impaired growth in utero is associated with physiological abnormalities in later life and have linked this to tissue programming during suboptimal intrauterine conditions at critical periods of development. However, few of these studies have considered the contribution of the placenta to the ensuing adult phenotype. In mammals, the major determinant of intrauterine growth is the placental nutrient supply, which, in turn, depends on the size, morphology, blood supply and transporter abundance of the placenta and on synthesis and metabolism of nutrients and hormones by the uteroplacental tissues. This review examines the regulation of placental nutrient transfer capacity and the potential programming effects of nutrition and glucocorticoid over-exposure on placental phenotype with particular emphasis on the role of the Igf2 gene in these processes. PMID:16439433

  19. Nutrient density: principles and evaluation tools.

    PubMed

    Drewnowski, Adam; Fulgoni, Victor L

    2014-05-01

    Nutrient profiling is the technique of rating or classifying foods on the basis of their nutritional value. Foods that supply relatively more nutrients than calories are defined as nutrient dense. Nutrient profile models calculate the content of key nutrients per 100 g, 100 kcal, or per serving size of food. For maximum effectiveness, nutrient profile models need to be transparent, based on publicly accessible nutrient composition data, and validated against independent measures of a healthy diet. These rigorous scientific standards were applied to the development of the Nutrient-Rich Foods (NRF) family of nutrient profile models. First, the NRF models included nutrients to encourage as well as nutrients to limit. Second, NRF model performance was repeatedly tested against the Healthy Eating Index (HEI), an independent measure of a healthy diet. HEI values were calculated for participants in the 1999-2002 NHANES. Models based on 100 kcal and serving sizes performed better than those based on 100 g. Formulas based on sums and means performed better than those based on ratios. The final NRF9.3 index was based on 9 beneficial nutrients (protein; fiber; vitamins A, C, and E; calcium; iron; potassium; and magnesium) and on 3 nutrients to limit (saturated fat, added sugar, and sodium). Higher NRF9.3 scores were associated with lower energy density and more nutrient-rich diets. The nutrient density of foods, paired with a comprehensive program of consumer education, can become the foundation of dietary recommendations and guidelines.

  20. Hungry for Nutrient Data? Navigating the USDA Nutrient Database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA National Nutrient Database for Standard Reference (SR) is the major source of food composition data in the United States, providing the foundation for most food composition databases in the public and private sectors. Most nutrition professionals are familiar with the basics of the SR onlin...

  1. Stillage processing for nutrient recovery

    SciTech Connect

    Sweeten, J.M.; Coble, C.G.; Egg, R.P.; Lawhon, J.T.; McBee, G.G.; Schelling, G.T.

    1983-06-01

    Stillage from fermentation of grain sorghum and sweet potatoes was processed for dry matter and nutrient recovery by combinations of screw press, vibrating screen, centrifugation, ultrafiltration, and reverse osmosis, yielding up to 98% dry matter removal. For most processes, protein removal equaled or exceeded dry matter removal.

  2. Regulating nutrient allocation in plants

    SciTech Connect

    Udvardi, Michael; Yang, Jiading; Worley, Eric

    2014-12-09

    The invention provides coding and promoter sequences for a VS-1 and AP-2 gene, which affects the developmental process of senescence in plants. Vectors, transgenic plants, seeds, and host cells comprising heterologous VS-1 and AP-2 genes are also provided. Additionally provided are methods of altering nutrient allocation and composition in a plant using the VS-1 and AP-2 genes.

  3. Rhizosphere priming: a nutrient perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizosphere priming is the change in decomposition of soil organic matter (SOM) caused by root activity. Rhizosphere priming plays a crucial role in soil carbon (C) dynamics and their response to global climate change. Rhizosphere priming may be affected by soil nutrient availability, but rhizospher...

  4. Mitochondria in response to nutrients and nutrient-sensitive pathways.

    PubMed

    Baltzer, Claudia; Tiefenböck, Stefanie K; Frei, Christian

    2010-11-01

    Mitochondria are abundant cellular organelles, and are required for the generation of energy through oxidative catabolism. Equally important, mitochondria also provide substrates for de novo synthesis of fatty acids and multiple amino acids. Mitochondrial functions must therefore be tightly linked to cellular nutrient availability. This review focuses on the current knowledge of how nutrients affect mitochondria. In particular, we describe how the transcriptional profile of the nucleus is altered to mediate this control, and the transcription factors that are involved. In addition, we summarize recent progress in our understanding of how transcription-independent mechanisms, most notably through the cellular energy sensor mTOR, are used to adapt mitochondrial functions in respect to cellular metabolic needs.

  5. Nutrient enrichment and nutrient regeneration stimulate bacterioplankton growth.

    PubMed

    Chrzanowski, T H; Sterner, R W; Elser, J J

    1995-05-01

    Bacterial abundance results from predatory losses of individuals and replacement of losses through growth. Growth depends on sustained input of organic substrates and mineral nutrients. In this work we tested the hypothesis that bacterial growth in two oligotrophic Canadian shield lakes was limited by nitrogen (N) or phosphorus (P). We also determined whether consumer-regenerated resources contributed substantially to net bacterial growth. Two types of dilution assays were conducted to determine the response of bacteria to nutrient enrichment: diluted whole water (DWW, 1:9 whole/filtered with 0.2 μm of filtered lake water) and diluted fractionated water (DFW, 1.0 μm prefiltered then diluted as above). Replicate bottles in each dilution assay received either N (50 μM), P (10 μM), or both N and P enrichments. Controls received no nutrients. Resource-saturated growth rates and grazing rates were estimated from a standard dilution-growth approach. Bacterial growth was stimulated by addition of P alone and in combination with N. Consumers regenerated sufficient resources to support up to half the bacterial growth rate, but the benefit derived from consumers was minor when compared to mortality. PMID:24185342

  6. Nutrient enrichment and nutrient regeneration stimulate bacterioplankton growth.

    PubMed

    Chrzanowski, T H; Sterner, R W; Elser, J J

    1995-05-01

    Bacterial abundance results from predatory losses of individuals and replacement of losses through growth. Growth depends on sustained input of organic substrates and mineral nutrients. In this work we tested the hypothesis that bacterial growth in two oligotrophic Canadian shield lakes was limited by nitrogen (N) or phosphorus (P). We also determined whether consumer-regenerated resources contributed substantially to net bacterial growth. Two types of dilution assays were conducted to determine the response of bacteria to nutrient enrichment: diluted whole water (DWW, 1:9 whole/filtered with 0.2 μm of filtered lake water) and diluted fractionated water (DFW, 1.0 μm prefiltered then diluted as above). Replicate bottles in each dilution assay received either N (50 μM), P (10 μM), or both N and P enrichments. Controls received no nutrients. Resource-saturated growth rates and grazing rates were estimated from a standard dilution-growth approach. Bacterial growth was stimulated by addition of P alone and in combination with N. Consumers regenerated sufficient resources to support up to half the bacterial growth rate, but the benefit derived from consumers was minor when compared to mortality.

  7. ERD Research on Nutrient and Pathogen Dynamics

    EPA Science Inventory

    Slide presentation giving an overview on the ERD research on nutrient and pathogen dynamics. Focus is on characterizing the dynamics of pathogen and nutrient stressors in the environment to support water quality objectives.

  8. Automated nutrient analyses in seawater

    SciTech Connect

    Whitledge, T.E.; Malloy, S.C.; Patton, C.J.; Wirick, C.D.

    1981-02-01

    This manual was assembled for use as a guide for analyzing the nutrient content of seawater samples collected in the marine coastal zone of the Northeast United States and the Bering Sea. Some modifications (changes in dilution or sample pump tube sizes) may be necessary to achieve optimum measurements in very pronounced oligotrophic, eutrophic or brackish areas. Information is presented under the following section headings: theory and mechanics of automated analysis; continuous flow system description; operation of autoanalyzer system; cookbook of current nutrient methods; automated analyzer and data analysis software; computer interfacing and hardware modifications; and trouble shooting. The three appendixes are entitled: references and additional reading; manifold components and chemicals; and software listings. (JGB)

  9. Nutrient Data Bases--Considerations for Educators.

    ERIC Educational Resources Information Center

    Hoover, Loretta W.; Pelican, Suzanne

    1984-01-01

    Examines sources and limitations of nutrient data and databases, and discusses some educational issues surrounding their selection and use in nutrient analysis programs. Tables illustrating the state of development of methods for nutrients in food, and selected United States Department of Agriculture (USDA) databases. (JN)

  10. Nutrient quality of fast food kids meals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exposure of children to kids’ meals at fast food restaurants is high; however, the nutrient quality of such meals has not been systematically assessed. We assessed the nutrient quality of fast food meals marketed to young children, i.e., "kids meals". The nutrient quality of kids’ meals was assessed...

  11. Spectral Quantitation Of Hydroponic Nutrients

    NASA Technical Reports Server (NTRS)

    Schlager, Kenneth J.; Kahle, Scott J.; Wilson, Monica A.; Boehlen, Michelle

    1996-01-01

    Instrument continuously monitors hydroponic solution by use of absorption and emission spectrometry to determine concentrations of principal nutrients, including nitrate, iron, potassium, calcium, magnesium, phosphorus, sodium, and others. Does not depend on extraction and processing of samples, use of such surrograte parameters as pH or electrical conductivity for control, or addition of analytical reagents to solution. Solution not chemically altered by analysis and can be returned to hydroponic process stream after analysis.

  12. Rhizosphere priming: a nutrient perspective.

    PubMed

    Dijkstra, Feike A; Carrillo, Yolima; Pendall, Elise; Morgan, Jack A

    2013-01-01

    Rhizosphere priming is the change in decomposition of soil organic matter (SOM) caused by root activity. Rhizosphere priming plays a crucial role in soil carbon (C) dynamics and their response to global climate change. Rhizosphere priming may be affected by soil nutrient availability, but rhizosphere priming itself can also affect nutrient supply to plants. These interactive effects may be of particular relevance in understanding the sustained increase in plant growth and nutrient supply in response to a rise in atmospheric CO2 concentration. We examined how these interactions were affected by elevated CO2 in two similar semiarid grassland field studies. We found that an increase in rhizosphere priming enhanced the release of nitrogen (N) through decomposition of a larger fraction of SOM in one study, but not in the other. We postulate that rhizosphere priming may enhance N supply to plants in systems that are N limited, but that rhizosphere priming may not occur in systems that are phosphorus (P) limited. Under P limitation, rhizodeposition may be used for mobilization of P, rather than for decomposition of SOM. Therefore, with increasing atmospheric CO2 concentrations, rhizosphere priming may play a larger role in affecting C sequestration in N poor than in P poor soils. PMID:23908649

  13. Rhizosphere priming: a nutrient perspective

    PubMed Central

    Dijkstra, Feike A.; Carrillo, Yolima; Pendall, Elise; Morgan, Jack A.

    2013-01-01

    Rhizosphere priming is the change in decomposition of soil organic matter (SOM) caused by root activity. Rhizosphere priming plays a crucial role in soil carbon (C) dynamics and their response to global climate change. Rhizosphere priming may be affected by soil nutrient availability, but rhizosphere priming itself can also affect nutrient supply to plants. These interactive effects may be of particular relevance in understanding the sustained increase in plant growth and nutrient supply in response to a rise in atmospheric CO2 concentration. We examined how these interactions were affected by elevated CO2 in two similar semiarid grassland field studies. We found that an increase in rhizosphere priming enhanced the release of nitrogen (N) through decomposition of a larger fraction of SOM in one study, but not in the other. We postulate that rhizosphere priming may enhance N supply to plants in systems that are N limited, but that rhizosphere priming may not occur in systems that are phosphorus (P) limited. Under P limitation, rhizodeposition may be used for mobilization of P, rather than for decomposition of SOM. Therefore, with increasing atmospheric CO2 concentrations, rhizosphere priming may play a larger role in affecting C sequestration in N poor than in P poor soils. PMID:23908649

  14. Nutrient Cycling in Piermont Marsh

    NASA Astrophysics Data System (ADS)

    Reyes, N.; Gribbin, S.; Newton, R.; Diaz, K.; Laporte, N.; Trivino, G.; Ortega, J.; McKee, K.; Sambrotto, R.

    2011-12-01

    We investigate the cycling of nutrients through a brackish tidal wetland about 40 km north of Manhattan in the Hudson River estuary. As part of a long-term ecological study of Piermont Marsh, a NOAA reference wetland managed by the NY State DEC, we are measuring dissolved inorganic nutrients on the Marsh surface and its drainage channels. The marsh occupies 400 acres along the southwest corner of Haverstraw Bay with approximately 2 km frontage to the estuary. It is supplied with nutrient-rich water and drained primarily along several tidal creeks and the hundreds of rivulets that feed them. During most tidal cycles the silty berm bounding the marsh is not topped. Human influence in the marsh's surrounding area has had profound effects, one of the most fundamental of which has been the shift from native grass species, predominantly Spartina alterniflora, to an invasive genotype of common reed, Phragmites australis. Along with this shift there have been changes in the root bed, the effective marsh interior and berm heights, the hydroperiod and, as a result, the ability of the marsh to be utilized by various types of Hudson estuary fish. The vegetative shift is believed to be anthropogenic, but the connection is not well understood, and it is not known what role biogeochemical perturbations are playing. We present two field seasons of nitrate, phosphate and silicate measurements from Sparkill Creek, a freshwater stream draining the surrounding highlands constitutes the northern boundary, two tidally driven creeks transect the Marsh from West to East: the Crumkill and an unnamed creek we have dubbed the "Tidal", Ludlow Ditch, a no-longer-maintained drainage channel grading gently from the northern part of the marsh to the South terminates in a wide tidal outlet that is its southern boundary. Net tidal cycle fluxes and fluxes resulting from runoff events are presented. Deviations from Redfield ratios and limiting nutrients are analyzed. Piermont Marsh data is compared

  15. Nutrient Management in Recirculating Hydroponic Culture

    NASA Technical Reports Server (NTRS)

    Bugbee, Bruce

    2004-01-01

    There is an increasing need to recirculate and reuse nutrient solutions in order to reduce environmental and economic costs. However, one of the weakest points in hydroponics is the lack of information on managing the nutrient solution. Many growers and research scientists dump out nutrient solutions and refill at weekly intervals. Other authors have recommended measuring the concentrations of individual nutrients in solution as a key to nutrient control and maintenance. Dumping and replacing solution is unnecessary. Monitoring ions in solution is not always necessary; in fact the rapid depletion of some nutrients often causes people to add toxic amounts of nutrients to the solution. Monitoring ions in solution is interesting, but it is not the key to effective maintenance.

  16. Generalized Nutrient Taxes Can Increase Consumer Welfare.

    PubMed

    Bishai, David

    2015-11-01

    Certain nutrients can stimulate appetite making them fattening in a way that is not fully conveyed by the calorie content on the label. For rational eaters, this information gap could be corrected by more labeling. As an alternative, this paper proposes a set of positive and negative taxes on the fattening and slimming nutrients in food rather than on the food itself. There are conditions under which this tax plus subsidy system could increase welfare by stopping unwanted weight gain while leaving the final retail price of food unchanged. A nutrient tax system could improve welfare if fattening nutrients, net of their effect on weight, are inferior goods and the fiscal cost of administering the tax is sufficiently low. More data on the price elasticity of demand for nutrients as well as data on how specific nutrients affect satiety and how total calorie intake would be necessary before one could be sure a nutrient tax would work in practice.

  17. Generalized Nutrient Taxes Can Increase Consumer Welfare.

    PubMed

    Bishai, David

    2015-11-01

    Certain nutrients can stimulate appetite making them fattening in a way that is not fully conveyed by the calorie content on the label. For rational eaters, this information gap could be corrected by more labeling. As an alternative, this paper proposes a set of positive and negative taxes on the fattening and slimming nutrients in food rather than on the food itself. There are conditions under which this tax plus subsidy system could increase welfare by stopping unwanted weight gain while leaving the final retail price of food unchanged. A nutrient tax system could improve welfare if fattening nutrients, net of their effect on weight, are inferior goods and the fiscal cost of administering the tax is sufficiently low. More data on the price elasticity of demand for nutrients as well as data on how specific nutrients affect satiety and how total calorie intake would be necessary before one could be sure a nutrient tax would work in practice. PMID:25241653

  18. Insects, infestations and nutrient fluxes

    NASA Astrophysics Data System (ADS)

    Michalzik, B.

    2012-04-01

    Forest ecosystems are characterized by a high temporal and spatial variability in the vertical transfer of energy and matter within the canopy and the soil compartment. The mechanisms and controlling factors behind canopy processes and system-internal transfer dynamics are imperfectly understood at the moment. Seasonal flux diversities and inhomogeneities in throughfall composition have been reported from coniferous and deciduous forests, and in most cases leaf leaching has been considered as principle driver for differences in the amount and quality of nutrients and organic compounds (Tukey and Morgan 1963). Since herbivorous insects and the processes they initiate received less attention in past times, ecologists now emphasize the need for linking biological processes occurring in different ecosystem strata to explain rates and variability of nutrient cycling (Bardgett et al. 1998, Wardle et al. 2004). Consequently, herbivore insects in the canopies of forests are increasingly identified to play an important role for the (re)cycling and availability of nutrients, or, more generally, for the functioning of ecosystems not only in outbreak situations but also at endemic (non-outbreak) density levels (Stadler et al. 2001, Hunter et al. 2003). Before, little attention was paid to insect herbivores when quantifying element and energy fluxes through ecosystems, although the numerous and different functions insects fulfill in ecosystems (e.g. as pollinators, herbivores or detritivores) were unanimously recognized (Schowalter 2000). Amongst the reasons for this restraint was the argument that the total biomass of insects tends to be relatively low compared to the biomass of trees or the pool of soil organic matter (Ohmart et al. 1983). A second argument which was put forward to justify the inferior role of insects in nutrient cycling were the supposed low defoliation losses between 5-10% of the annual leaf biomass, or net primary production, due to insect herbivory under

  19. Plant and pathogen nutrient acquisition strategies

    PubMed Central

    Fatima, Urooj; Senthil-Kumar, Muthappa

    2015-01-01

    Nutrients are indispensable elements required for the growth of all living organisms including plants and pathogens. Phyllosphere, rhizosphere, apoplast, phloem, xylem, and cell organelles are the nutrient niches in plants that are the target of bacterial pathogens. Depending upon nutrients availability, the pathogen adapts various acquisition strategies and inhabits the specific niche. In this review, we discuss the nutrient composition of different niches in plants, the mechanisms involved in the recognition of nutrient niche and the sophisticated strategies used by the bacterial pathogens for acquiring nutrients. We provide insight into various nutrient acquisition strategies used by necrotrophic, biotrophic, and hemibiotrophic bacteria. Specifically we discuss both modulation of bacterial machinery and manipulation of host machinery. In addition, we highlight the current status of our understanding about the nutrient acquisition strategies used by bacterial pathogens, namely targeting the sugar transporters that are dedicated for the plant’s growth and development. Bacterial strategies for altering the plant cell membrane permeability to enhance the release of nutrients are also enumerated along with in-depth analysis of molecular mechanisms behind these strategies. The information presented in this review will be useful to understand the plant–pathogen interaction in nutrient perspective. PMID:26442063

  20. Nutrient balance on Nebraska livestock confinement systems.

    PubMed

    Koelsch, R; Lesoing, G

    1999-01-01

    Managing the environmental risk associated with livestock production is a significant challenge. Nitrogen and phosphorus are commonly implicated as the sources of ground and surface water quality problems associated with livestock production. The degree of imbalance between these nutrient inputs and the managed nutrient outputs for a livestock operation defines the magnitude of potential environmental risk and provides insight as to the underlying causes of these challenges. A nitrogen and phosphorus balance was constructed for 33 Nebraska confinement livestock operations. Twenty-five and 17 of these operations experienced significant nitrogen and phosphorus imbalances, respectively (50% more nutrient inputs than outputs). Nutrient inputs on many livestock operations were observed to be two to four times greater than nutrient outputs as managed crop and livestock products. Size of the livestock operation and the degree of integration of livestock with a cropping operation provided only limited explanation of the variation in nutrient balance observed among the individual operations. Management options that contribute to a more favorable nutrient balance were also identified. Management decisions related to feeding program and exporting of manure nutrients to off-farm users were observed to have a substantial impact on the nutrient imbalance. For modern livestock production systems to successfully respond to nutrient-related environmental problems, management strategies must be implemented that address the commonly experienced imbalances of nitrogen and phosphorus. PMID:15526781

  1. [Nutrient supplements - possibilities and limitations].

    PubMed

    Ströhle, Alexander; Hahn, Andreas

    2013-05-01

    The consumption of micronutrient-supplements by the general public has become widespread; between 25 and more than 40% of individuals questioned in western developed nations confirm to regularly consume such products. In principle, there are two product categories for micronutrient-supplements - medicinal products (drugs) and foodstuffs. The latter are marketed as food supplements (FS) and dietary foodstuffs for particular nutritional uses including foods for special medical purposes (FSMP). FS serve the general supplementation of any consumer whilst foodstuffs for particular nutritional uses are directed at consumers with special dietary requirements; FSMP are intended for the dietary management of patients. There are clearly defined legal frameworks for those product categories. Independently of their legal product status, six areas of application can be characterised for micronutrient-supplements: general and special supplementation, primary prevention, compensation of disease-related deficits, therapeutic function and containment of diseases or avoidance of subsequent damages (secondary and tertiary function). Gauged with the mean-intake, micro nutrient supply in Germany is sufficient (exception: folic acid and vitamin D; partially also iodine). However, the intake of vitamins E, C, B1 and B2 as well as the minerals calcium, magnesium, zinc and iodine could be improved in 20-50% of the general public. Micro nutrient preparations in physiological dose could contribute to closing this gap in supply.

  2. Nutrient content of whole cottonseed.

    PubMed

    Bertrand, J A; Sudduth, T Q; Condon, A; Jenkins, T C; Calhoun, M C

    2005-04-01

    The objective of this study was to determine if the nutrient and gossypol contents and in vitro digestibility of 3 types of genetically modified whole cottonseed differed from traditional whole cottonseed. Samples of seed from traditional (no genetic modifications) and genetically modified varieties of cotton grown in 1999 and 2000 were analyzed. Genetic modifications included the insertion of genes to protect cotton from insect pests (Bt), and damage from glyphosate herbicides (RR), and from both (Bt/RR). Year effects were significant for in vitro dry matter (DM) digestibility, gossypol, DM, crude protein (CP), fat, neutral detergent fiber (NDF), acid detergent fiber (ADF), and ash. Higher rainfall resulted in higher CP, fat, and ash and lower NDF and gossypol. There were no differences among seed types for ground or whole seed digestibility, DM, CP, fat, NDF, ADF, ash, lignin, net energy for lactation, amino acids, total fatty acids, or seed index. Overall, the nutrient content and digestibility of varieties of genetically modified seed were similar to that of varieties of traditional whole cottonseed.

  3. Adaptability of growth and nutrient uptake potential of Chlorella sorokiniana with variable nutrient loading.

    PubMed

    Shriwastav, Amritanshu; Gupta, Sanjay Kumar; Ansari, Faiz Ahmad; Rawat, Ismail; Bux, Faizal

    2014-12-01

    Chlorella sorokiniana can sustain growth in conditions hostile to other species, and possesses good nutrient removal and lipid accumulation potentials. However, the effects of variable nutrient levels (N and P) in wastewaters on growth, productivity, and nutrient uptake by C. sorokiniana have not been studied in detail. This study demonstrates the ability of this alga to sustain uniform growth and productivity, while regulating the relative nutrient uptake in accordance to their availability in the bulk medium. These results highlight the potential of C. sorokiniana as a suitable candidate for fulfilling the coupled objectives of nutrient removal and biomass production for bio-fuel with wastewaters having great variability in nutrient levels.

  4. Nutrients and Circadian Rhythms in Mammals.

    PubMed

    Wu, Tao; Yao, Cencen; Huang, Liangfeng; Mao, Youxiang; Zhang, Wanjing; Jiang, Jianguo; Fu, Zhengwei

    2015-01-01

    The circadian rhythm is generally existed in mammalian behavior and metabolic processes, which results from the self-sustained circadian clocks. The mammalian circadian clocks are composed of a master clock located in the hypothalamic suprachiasmatic nucleus (SCN), and of many peripheral clocks in tissues and extra-SCN brain regions. It is indicated that feeding could take over part of the SCN signaling, and affect internal synchrony between the master clock and the peripheral clocks. Thus, recent studies focus more on the relationship between the nutrients and circadian rhythms. Various nutrient components (glucose, amino acid, alcohol) are found to be able to directly affect the circadian rhythm of clock genes. Moreover, the feeding schedule of nutrients is as important as the nutrient components in maintaining a healthy circadian rhythm. Therefore, the circadian homeostasis needs not only balanced nutrient components but also regular timed nutrients.

  5. Managing urban nutrient biogeochemistry for sustainable urbanization.

    PubMed

    Lin, Tao; Gibson, Valerie; Cui, Shenghui; Yu, Chang-Ping; Chen, Shaohua; Ye, Zhilong; Zhu, Yong-Guan

    2014-09-01

    Urban ecosystems are unique in the sense that human activities are the major drivers of biogeochemical processes. Along with the demographic movement into cities, nutrients flow towards the urban zone (nutrient urbanization), causing the degradation of environmental quality and ecosystem health. In this paper, we summarize the characteristics of nutrient cycling within the urban ecosystem compared to natural ecosystems. The dynamic process of nutrient urbanization is then explored taking Xiamen city, China, as an example to examine the influence of rapid urbanization on food sourced nitrogen and phosphorus metabolism. Subsequently, the concept of a nutrient footprint and calculation method is introduced from a lifecycle perspective. Finally, we propose three system approaches to mend the broken biogeochemical cycling. Our study will contribute to a holistic solution which achieves synergies between environmental quality and food security, by integrating technologies for nutrient recovery and waste reduction.

  6. Control of microorganisms in flowing nutrient solutions.

    PubMed

    Evans, R D

    1994-11-01

    Controlling microorganisms in flowing nutrient solutions involves different techniques when targeting the nutrient solution, hardware surfaces in contact with the solution, or the active root zone. This review presents basic principles and applications of a number of treatment techniques, including disinfection by chemicals, ultrafiltration, ultrasonics, and heat treatment, with emphasis on UV irradiation and ozone treatment. Procedures for control of specific pathogens by nutrient solution conditioning also are reviewed.

  7. Nutrient availability moderates transpiration in Ehrharta calycina.

    PubMed

    Cramer, Michael D; Hoffmann, Vera; Verboom, G Anthony

    2008-01-01

    Transpiration-driven 'mass-flow' of soil-water can increase nutrient flow to the root surface. Here it was investigated whether transpiration could be partially regulated by nutrient status. Seeds of Ehrharta calycina from nine sites across a rainfall gradient were supplied with slow-release fertilizer dibbled into the sand surrounding the roots and directly available through interception, mass-flow and diffusion (dubbed 'interception'), or sequestered behind a 40-microm mesh and not directly accessible by the roots, but from which nutrients could move by diffusion or mass-flow (dubbed 'mass-flow'). Although mass-flow plants were significantly smaller than interception plants as a consequence of nutrient limitation, they transpired 60% faster, had 90% higher photosynthesis relative to transpiration (A/E), and 40% higher tissue P, Ca and Na concentrations than plants allowed to intercept nutrients directly. Tissue N and K concentrations were similar for interception and mass-flow plants. Transpiration was thus higher in the nutrient-constrained 'mass-flow' plants, increasing the transport of nutrients to the roots by mass-flow. Transpiration may have been regulated by N availability, resulting in similar tissue concentration between treatments. It is concluded that, although transpiration is a necessary consequence of photosynthetic CO(2) uptake in C(3) plants, plants can respond to nutrient limitation by varying transpiration-driven mass-flow of nutrients.

  8. Nutrient-Specific Foraging in Invertebrate Predators

    NASA Astrophysics Data System (ADS)

    Mayntz, David; Raubenheimer, David; Salomon, Mor; Toft, Søren; Simpson, Stephen J.

    2005-01-01

    Many herbivores and omnivores adjust their food selection behavior to regulate the intake of multiple nutrients. Carnivores, however, are generally assumed to optimize the rate of prey capture rather than select prey according to nutrient composition. We showed experimentally that invertebrate predators can forage selectively for protein and lipids to redress specific nutritional imbalances. This selection can take place at different stages of prey handling: The predator may select among foods of different nutritional composition, eat more of a prey if it is rich in nutrients that the predator is deficient in, or extract specific nutrients from a single prey item.

  9. Nutrient-specific foraging in invertebrate predators.

    PubMed

    Mayntz, David; Raubenheimer, David; Salomon, Mor; Toft, Søren; Simpson, Stephen J

    2005-01-01

    Many herbivores and omnivores adjust their food selection behavior to regulate the intake of multiple nutrients. Carnivores, however, are generally assumed to optimize the rate of prey capture rather than select prey according to nutrient composition. We showed experimentally that invertebrate predators can forage selectively for protein and lipids to redress specific nutritional imbalances. This selection can take place at different stages of prey handling: The predator may select among foods of different nutritional composition, eat more of a prey if it is rich in nutrients that the predator is deficient in, or extract specific nutrients from a single prey item.

  10. Numerical simulations of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay, Indonesia.

    PubMed

    van der Wulp, Simon A; Damar, Ario; Ladwig, Norbert; Hesse, Karl-J

    2016-09-30

    The present application of numerical modelling techniques provides an overview of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay. A hydrological model simulated river discharges with a total of 90 to 377m(3)s(-1) entering Jakarta Bay. Daily total nitrogen and total phosphorus loads ranged from 40 to 174tons and 14 to 60tons, respectively. Flow model results indicate that nutrient gradients are subject to turbulent mixing by tides and advective transport through circulation driven by wind, barotropic and baroclinic pressure gradients. The bulk of nutrient loads originate from the Citarum and Cisadane rivers flowing through predominantly rural areas. Despite lower nutrient loads, river discharges from the urban area of Jakarta exhibit the highest impact of nutrient concentrations in the near shore area of Jakarta Bay and show that nutrient concentrations were not only regulated by nutrient loads but were strongly regulated by initial river concentrations and local flow characteristics. PMID:27283876

  11. NUTRIENT UPTAKE: A Microcomputer Program to Predict Nutrient Absorption from Soil by Roots.

    ERIC Educational Resources Information Center

    Oates, Kenneth; Barber, S. A.

    1987-01-01

    Discusses the use of a computer program designed to solve the mathematical model associated with soil nutrient uptake by plant roots and to predict the nutrient uptake. Describes a user-friendly personal computer version of this program. (TW)

  12. Numerical simulations of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay, Indonesia.

    PubMed

    van der Wulp, Simon A; Damar, Ario; Ladwig, Norbert; Hesse, Karl-J

    2016-09-30

    The present application of numerical modelling techniques provides an overview of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay. A hydrological model simulated river discharges with a total of 90 to 377m(3)s(-1) entering Jakarta Bay. Daily total nitrogen and total phosphorus loads ranged from 40 to 174tons and 14 to 60tons, respectively. Flow model results indicate that nutrient gradients are subject to turbulent mixing by tides and advective transport through circulation driven by wind, barotropic and baroclinic pressure gradients. The bulk of nutrient loads originate from the Citarum and Cisadane rivers flowing through predominantly rural areas. Despite lower nutrient loads, river discharges from the urban area of Jakarta exhibit the highest impact of nutrient concentrations in the near shore area of Jakarta Bay and show that nutrient concentrations were not only regulated by nutrient loads but were strongly regulated by initial river concentrations and local flow characteristics.

  13. Variable primary producer responses to nutrient and temperature manipulations in mesocosms: temperature usually trumps nutrient effects

    EPA Science Inventory

    Mesocosm experiments have been used to evaluate the impacts of nutrient loading on estuarine plant communities in order to develop nutrient response relationships. Mesocosm eutrophication studies tend to focus on long residence time systems. In the Pacific Northwest, many estuari...

  14. Nutrient Models Developments Using Runoff-Nutrient Relationships in an Agricultural Prairie Basin, Manitoba.

    NASA Astrophysics Data System (ADS)

    Mahmood, T. H.; Pomeroy, J. W.; Wheater, H. S.; Elliott, J. A.; Baulch, H. M.; Lindenschmidt, K. E.

    2015-12-01

    Nutrient export to streams and lakes from agricultural activities can result in significant deterioration of water quality and aquatic ecosystem health. In Western Canada, particular concerns arise for prairie agricultural systems, which are dominated by the effects of a cold climate. Insufficient attention has been given to understand the links between cold region watershed responses and nutrient concentration and a robust watershed-scale modeling framework is needed to simulate nutrient concentration and loads. Long-term, field observations of nutrient concentration-runoff relationships were used to develop nutrient concentration models for the Tobacco Creek Model Watershed (TCMW) which drains into the Red River basin. Field observations include streamflow concentrations of N and P at multiple scales from two headwater basins. Distinct nutrient concentration-runoff models for snowmelt, rain on snow (ROS) and rainfall runoff processes were developed from observed runoff-nutrient concentration relationships. Snowmelt runoff had a moderately positive correlation with particulate nutrient concentrations but no correlation with that of dissolved nutrients. ROS runoff had a weak relationship with both particulate and dissolved nutrient concentrations. Rainfall runoff had the strongest positive correlation with particulate nutrient concentrations but no association with that of dissolved nutrients. The modeling approach also identified a clear hysteretic behavior in the relationship between runoff and particulate nutrient concentration during the 2013 snowmelt runoff event at the basin outlet gauge. The models provide insight into the hydrological controls on nutrient export from cold regions watersheds and the strong effects of inter-annual climatic variability. Snowmelt runoff is a reliable exporter of large nutrient loads while nutrient export by rainfall runoff exceeded snowmelt runoff during hydrologically wet summers such as 2002, 2005, 2011 and 2013.

  15. Grassland productivity limited by multiple nutrients.

    PubMed

    Fay, Philip A; Prober, Suzanne M; Harpole, W Stanley; Knops, Johannes M H; Bakker, Jonathan D; Borer, Elizabeth T; Lind, Eric M; MacDougall, Andrew S; Seabloom, Eric W; Wragg, Peter D; Adler, Peter B; Blumenthal, Dana M; Buckley, Yvonne M; Chu, Chengjin; Cleland, Elsa E; Collins, Scott L; Davies, Kendi F; Du, Guozhen; Feng, Xiaohui; Firn, Jennifer; Gruner, Daniel S; Hagenah, Nicole; Hautier, Yann; Heckman, Robert W; Jin, Virginia L; Kirkman, Kevin P; Klein, Julia; Ladwig, Laura M; Li, Qi; McCulley, Rebecca L; Melbourne, Brett A; Mitchell, Charles E; Moore, Joslin L; Morgan, John W; Risch, Anita C; Schütz, Martin; Stevens, Carly J; Wedin, David A; Yang, Louie H

    2015-07-06

    Terrestrial ecosystem productivity is widely accepted to be nutrient limited(1). Although nitrogen (N) is deemed a key determinant of aboveground net primary production (ANPP)(2,3), the prevalence of co-limitation by N and phosphorus (P) is increasingly recognized(4-8). However, the extent to which terrestrial productivity is co-limited by nutrients other than N and P has remained unclear. Here, we report results from a standardized factorial nutrient addition experiment, in which we added N, P and potassium (K) combined with a selection of micronutrients (K+μ), alone or in concert, to 42 grassland sites spanning five continents, and monitored ANPP. Nutrient availability limited productivity at 31 of the 42 grassland sites. And pairwise combinations of N, P, and K+μ co-limited ANPP at 29 of the sites. Nitrogen limitation peaked in cool, high latitude sites. Our findings highlight the importance of less studied nutrients, such as K and micronutrients, for grassland productivity, and point to significant variations in the type and degree of nutrient limitation. We suggest that multiple-nutrient constraints must be considered when assessing the ecosystem-scale consequences of nutrient enrichment.

  16. Crop nutrient recovery from applied fish coproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Alaska fishing industry produces over 1,000,000 metric tons of fish byproducts annually, and most of them are not used. Most food in Alaska is imported. Fish byproducts are rich in plant essential nutrients and can be used as nutrient sources for crop production. The objective of the study was t...

  17. Seasonal sediment and nutrients transport patterns

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is essential to understand sediment and nutrient sources and their spatial and temporal patterns in order to design effective mitigation strategies. However, long-term data sets to determine sediment and nutrient loadings are scarce and expensive to collect. The goal of this study was to determin...

  18. 21 CFR 107.10 - Nutrient information.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... Phosphorus Do. Magnesium Do. Iron Do. Zinc Do. Manganese Micrograms. Copper Do. Iodine Do. Sodium Milligrams... minerals may be declared between iodine and sodium, provided that any additionally declared nutrient (i... minerals may be declared between iodine and sodium, provided that any additionally declared nutrient:...

  19. Nutrient recycling affects autotroph and ecosystem stoichiometry.

    PubMed

    Ballantyne, Ford; Menge, Duncan N L; Ostling, Annette; Hosseini, Parviez

    2008-04-01

    Stoichiometric nutrient ratios are the consequence of myriad interacting processes, both biotic and abiotic. Theoretical explanations for autotroph stoichiometry have focused on species' nutrient requirements but have not addressed the role of nutrient availability in determining autotroph stoichiometry. Remineralization of organic N and P supplies a significant fraction of inorganic N and P to autotrophs, making nutrient recycling a potentially important process influencing autotroph stoichiometry. To quantitatively investigate the relationship between available N and P, autotroph N:P, and nutrient recycling, we analyze a stoichiometrically explicit model of autotroph growth, incorporating Michaelis-Menten-Monod nutrient uptake kinetics, Droop growth, and Liebig's law of the minimum. If autotroph growth is limited by a single nutrient, increased recycling of the limiting nutrient pushes autotrophs toward colimitation and alters both autotroph and environmental stoichiometry. We derive a steady state relationship between input stoichiometry, autotroph N:P, and the stoichiometry of organic losses that allows us to estimate the relative recycling of N to P within an ecosystem. We then estimate relative N and P recycling for a marine, an aquatic, and two terrestrial ecosystems. Preferential P recycling, in conjunction with greater relative P retention at the organismal and ecosystem levels, presents a strong case for the importance of P to biomass production across ecosystems.

  20. Closed-Cycle Nutrient Supply For Hydroponics

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, Steven H.

    1991-01-01

    Hydroponic system controls composition and feed rate of nutrient solution and recovers and recycles excess solution. Uses air pressure on bladders to transfer aqueous nutrient solution. Measures and adjusts composition of solution before it goes to hydroponic chamber. Eventually returns excess solution to one of tanks. Designed to operate in microgravity, also adaptable to hydroponic plant-growing systems on Earth.

  1. Processes and patterns of oceanic nutrient limitation

    NASA Astrophysics Data System (ADS)

    Moore, C. M.; Mills, M. M.; Arrigo, K. R.; Berman-Frank, I.; Bopp, L.; Boyd, P. W.; Galbraith, E. D.; Geider, R. J.; Guieu, C.; Jaccard, S. L.; Jickells, T. D.; La Roche, J.; Lenton, T. M.; Mahowald, N. M.; Marañón, E.; Marinov, I.; Moore, J. K.; Nakatsuka, T.; Oschlies, A.; Saito, M. A.; Thingstad, T. F.; Tsuda, A.; Ulloa, O.

    2013-09-01

    Microbial activity is a fundamental component of oceanic nutrient cycles. Photosynthetic microbes, collectively termed phytoplankton, are responsible for the vast majority of primary production in marine waters. The availability of nutrients in the upper ocean frequently limits the activity and abundance of these organisms. Experimental data have revealed two broad regimes of phytoplankton nutrient limitation in the modern upper ocean. Nitrogen availability tends to limit productivity throughout much of the surface low-latitude ocean, where the supply of nutrients from the subsurface is relatively slow. In contrast, iron often limits productivity where subsurface nutrient supply is enhanced, including within the main oceanic upwelling regions of the Southern Ocean and the eastern equatorial Pacific. Phosphorus, vitamins and micronutrients other than iron may also (co-)limit marine phytoplankton. The spatial patterns and importance of co-limitation, however, remain unclear. Variability in the stoichiometries of nutrient supply and biological demand are key determinants of oceanic nutrient limitation. Deciphering the mechanisms that underpin this variability, and the consequences for marine microbes, will be a challenge. But such knowledge will be crucial for accurately predicting the consequences of ongoing anthropogenic perturbations to oceanic nutrient biogeochemistry.

  2. SSMILes: Measuring the Nutrient Tolerance of Algae.

    ERIC Educational Resources Information Center

    Hedgepeth, David J.

    1995-01-01

    Presents an activity integrating mathematics and science intended to introduce students to the use of metric measurement of mass as a way to increase the meaningfulness of observations about variables in life sciences. Involves measuring the nutrient tolerance of algae. Contains a reproducible algae nutrient graph. (Author/MKR)

  3. A Method for Developing a Nutrient Guide.

    ERIC Educational Resources Information Center

    Gillespie, Ardyth H.; Roderuck, Charlotte E.

    1982-01-01

    This paper proposes a new approach to developing a tool for teaching nutrition and food selection. It allows adjustments as new information becomes available and takes into account both dietary recommendations and food composition. Steps involve nutrient composition; nutrient density; and ratings for fat, cholesterol, and sodium. (Author/CT)

  4. Nutrient dynamics and food-web stability

    SciTech Connect

    DeAngelis, D.L.; Mulholland, P.J.; Palumbo, A.V.; Steinman, A.D.; Huston, M.A.; Elwood, J.W. )

    1989-01-01

    The importance of nutrient limitation and recycling in ecosystems is widely recognized. Nutrients, defined in the broad sense as all material elements vital to biological functions, are in such small supply that they limit production in many ecosystems. Such limitation can affect ecosystem properties, including the structure and dynamics of the food webs that link species through their feeding relationships. What are the effects of limiting nutrients on the stability of ecosystem food webs Most of the literature on food web stability centers around the dynamics of population numbers and/or biomasses. Nevertheless, a growing body of theoretical and empirical research considers the role that both nutrient limitation and recycling can play in stability. In this paper, it is the authors objective to summarize the current understanding of several important types of stability. The theoretical and empirical evidence relating these types of stability and nutrient cycling is described. A central generalization is produced in each case.

  5. Nutrients in the Changjiang River.

    PubMed

    Shen, Zhi-Liang; Liu, Qun

    2009-06-01

    N, P and SiO3-Si in the Changjiang mainstream and its major tributaries and lakes were investigated in the dry season from November to December, 1997, and in the flood season in August and October, 1998. An even distribution of SiO3-Si was found along the Changjiang River. However, the concentrations of total nitrogen, total dissolved nitrogen, dissolved inorganic nitrogen, nitrate and total phosphorus, total particulate phosphorus increased notably in the upper reaches, which reflected an increasing impact from human activities. Those concentrations in the middle and lower reaches of the Changjiang River were relatively constant. Dissolved N was the major form of N and the particulate P was the major form of P in the Changjiang River. The molar ratio of dissolved N to dissolved P was extremely high (192.5-317.5), while that of the particulate form was low (5.6-37.7). High N/P ratio reflected a significant input of anthropogenic N such as N from precipitation and N lost from water and soil etc. Dissolved N and P was in a quasi-equilibrium state in the process from precipitate to the river. In the turbid river water, light limitation, rather than P limitation, seemed more likely to be a controlling factor for the growth of phytoplankton. A positive linear correlationship between the concentration of dissolved N and the river's runoff was found, mainly in the upper reaches, which was related to the non-point sources of N. Over the past decades, N concentration has greatly increased, but the change of P concentration was not as significant as N. The nutrient fluxes of the Changjiang mainstream and tributaries were estimated, and the result showed that the nutrient fluxes were mainly controlled by the runoff, of which more than a half came from the tributaries. These investigations carried out before water storage of the Three Gorges Dam will supply a scientific base for studying the influences of the Three Gorges Dam on the ecology and environment of the Changjiang

  6. Nutrient-rich foods: applying nutrient navigation systems to improve public health.

    PubMed

    Drewnowski, A; Fulgoni, V L; Young, M K; Pitman, S

    2008-11-01

    The American diet is high in calories, but low in nutrients. To help consumers obtain more nutrition from the calories they consume, research is underway to develop a nutrient profiling approach that can be used to evaluate individual foods and help people build healthful diets. A nutrient profiling system that rates individual foods based on their nutrient content needs to be both science-driven and user-friendly, allowing consumers to make more healthful food choices within and across all the food groups. A recent survey, commissioned by the Nutrient Rich Food Coalition, reveals that the majority of consumers and nutrition professionals believe that better information about a food's total combined nutrient content would be effective and useful in helping them make more nutrient-rich food choices. PMID:19021805

  7. Glutamine as an immunoenhancing nutrient.

    PubMed

    Saito, H; Furukawa, S; Matsuda, T

    1999-01-01

    New strategies for immunonutritional support include administration of special nutrients such as glutamine. Glutamine is important in several key metabolic processes of immune cells and enterocytes. Exogenous glutamine augments the functions of lymphocytes and macrophages. Neutrophils also reportedly utilize glutamine at a significant rate. Our recent studies demonstrated that glutamine enhances neutrophil function. This article focuses on the effects of glutamine on neutrophil function in surgical stress. Enteral glutamine administration enhanced peritoneal and hepatic bacterial clearance in our rat peritonitis model. Furthermore, IV glutamine supplementation improved the outcome of animals with severe surgical stress. Our in vitro study revealed that supplemental glutamine augmented the bacterial killing function of neutrophils from postoperative patients. Glutamine increased phagocytosis of the neutrophils. In addition, glutamine dose-dependently increased production of reactive oxygen intermediates (ROI) by neutrophils. Thus, our studies suggest that glutamine supplementation may improve bactericidal function of neutrophils by increasing both phagocytosis and ROI production. In conclusion, glutamine plays an important role in neutrophil function. Glutamine may be useful for the prevention, and treatment, of severe infection in critical illness and trauma.

  8. Nutrient (N, P, Si) transfers in the subtropical Red River system (China and Vietnam): Modelling and budget of nutrient sources and sinks

    NASA Astrophysics Data System (ADS)

    Le, Thi Phuong Quynh; Gilles, Billen; Garnier, Josette; Sylvain, Théry; Denis, Ruelland; Anh, Nghiem Xuan; Minh, Chau Van

    2010-02-01

    The Red River system, which has a population density that varies from 80 to over 1000 inhabitants km -2 in the different sectors of its watershed, is a typical example of a subtropical system experiencing high human pressure. A monthly survey of nutrient concentration was conducted at the outlet of the three main tributaries (Da, Thao and Lo) and at Hanoi on the main branch of the Red River in the upper part of the delta. Samples from headwater streams or irrigation channels draining homogeneous land use classes also were analysed. A GIS database describing the characteristics of the watershed in terms of morphology, climate, land use and population has been established. This served as the basis for implementing the Seneque/Riverstrahler model, which allowed calculation of nutrient transfers and transformations along the whole drainage network of the Red River system. The model was validated using the measured nutrient concentrations obtained during the survey and was used to establish an overall description and a comprehensive budget of nutrient transfer, retention and delivery for the three main sub-basins and the upper part of the delta upstream from Hanoi.

  9. Chemolithotrophy and physiology of bacterial nutrient limitation

    NASA Technical Reports Server (NTRS)

    Matin, A.

    1985-01-01

    An overview of the physiology of chemolithotrophic bacteria, particularly the thiobacilli, was presented. In these bacteria unique physiological traits are expressed during nutrient limited growth. Different physiological types of chemolithotrophs, pathways of sulfur oxidation, and electron transport in the thiobacilli, problems encountered by chemolithotrophs in the generation of reducing power, and some explanations of the phenomenon of obligate chemolithotrophy were considered. Mixotrophy in the thiobacilli has been studied extensively both under nutrient excess and limitation. In nature, bacteria usually grow under nutrient limitation. Yet the bulk of our knowledge of microbial metabolic function is derived from bacteria grown in laboratory batch cultures containing a great abundance of nutrients. Microbial behavior in these two types of environments can be very different, indicating the need for basing an understanding of microbial ecology on studies that rely on cultivation of microorganisms under nutrient limitation. Nutrient limited bacteria differ in several ways from those growing in large quantities of nutrients. They have different surface structures and make a much fuller use of their metabolic potential, especially by the synthesis of unique pathways of catabolic enzymes.

  10. Using Reservoirs to Mitigate Nutrient Discharge

    NASA Astrophysics Data System (ADS)

    Zmijewski, N.; Worman, A. L. E.

    2015-12-01

    Reservoir management for the purpose of hydropower production alters the hydrological flow regime and can have significant impact on nutrient transport as well as ecology. Using reservoir management to reduce the nutrient load to downstream areas can be of great importance for aquatic habitats in recipient waters as well as the overall health of coastal areas. In this study the regulation of a network of reservoirs in River Dalälven, Sweden, is simulated using a multi-objective approach that accounts for both the nutrient export and power production. The optimization model is used to derive the Pareto front for the two objectives; the hydropower production and water quality objectives. The effect of regulation of River Dalälven on the nutrient transport is examined as a possible control method for limiting nutrient transport from the watershed. The cost in the form of loss of hydroelectric power is quantified. Optimization of a large-scale river network is done at great computational expense and the additional states (concentration of nutrient) increase the computational load significantly, for this reason several simplifications of the system dynamics are made. It is shown that a 50% reduction of the nutrient discharge can be achieved to a limited loss of power production (<5 - 10%), but that additional reduction is associated with a significant loss in power production.

  11. Linking nutrient enrichment, sediment erodibility and biofilms

    NASA Astrophysics Data System (ADS)

    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.

  12. Sources of Nutrients for Ocean Enrichment

    NASA Astrophysics Data System (ADS)

    Jones, I. S.

    2008-12-01

    The remarkable doubling of the productivity of the land over the last 50 years raises the question of opportunities to follow suit in the sea. The rapidly rising population makes increasing demands on food supply and the disposal of waste in the atmosphere from fossil fuel burning It is well known that the supply of nutrients to the photic zone of the ocean limits primary production and this limitation can be removed by the addition of nutrients. The surface waters of the ocean are typically in the photic zone for a decade and their initial quota of nutrients are supplemented by cyanobacteria, atmospheric deposition and river inflows. Together with upwelling these nutrients support about 10,000GtC of new primary production per year. Extra nutrients can be sourced from the thermocline, from enhancing the diazotrophs or by chemically transforming elements on the land or in the atmosphere. Using thermocline nutrients to enhance productivity but are first order neutral for carbon sequestration. Diazotrophs seem restricted to temperate and tropical waters and need phosphate and other nutrients. The increased nitrogen they provide is expected to lead to more carbon storage in the ocean. The macronutrients, nitrogen and phosphorus and the micronutrients have all been shown to be beneficial. With increased new primary production we expect increased sustainable fish production but the species composition will depend on the success of recruitment.

  13. Detecting Temporal Change in Watershed Nutrient Yields

    NASA Astrophysics Data System (ADS)

    Wickham, James D.; Wade, Timothy G.; Riitters, Kurt H.

    2008-08-01

    Meta-analyses reveal that nutrient yields tend to be higher for watersheds dominated by anthropogenic uses (e.g., urban, agriculture) and lower for watersheds dominated by natural vegetation. One implication of this pattern is that loss of natural vegetation will produce increases in watershed nutrient yields. Yet, the same meta-analyses also reveal that, absent land-cover change, watershed nutrient yields vary from one year to the next due to many exogenous factors. The interacting effects of land cover and exogenous factors suggest nutrient yields should be treated as distributions, and the effect of land-cover change should be examined by looking for significant changes in the distributions. We compiled nutrient yield distributions from published data. The published data included watersheds with homogeneous land cover that typically reported two or more years of annual nutrient yields for the same watershed. These data were used to construct statistical models, and the models were used to estimate changes in the nutrient yield distributions as a result of land-cover change. Land-cover changes were derived from the National Land Cover Database (NLCD). Total nitrogen (TN) yield distributions increased significantly for 35 of 1550 watersheds and decreased significantly for 51. Total phosphorus (TP) yield distributions increased significantly for 142 watersheds and decreased significantly for 17. The amount of land-cover change required to produce significant shifts in nutrient yield distributions was not constant. Small land-cover changes led to significant shifts in nutrient yield distributions when watersheds were dominated by natural vegetation, whereas much larger land-cover changes were needed to produce significant shifts when watersheds were dominated by urban or agriculture. We discuss our results in the context of the Clean Water Act.

  14. Detecting temporal change in watershed nutrient yields.

    PubMed

    Wickham, James D; Wade, Timothy G; Riitters, Kurt H

    2008-08-01

    Meta-analyses reveal that nutrient yields tend to be higher for watersheds dominated by anthropogenic uses (e.g., urban, agriculture) and lower for watersheds dominated by natural vegetation. One implication of this pattern is that loss of natural vegetation will produce increases in watershed nutrient yields. Yet, the same meta-analyses also reveal that, absent land-cover change, watershed nutrient yields vary from one year to the next due to many exogenous factors. The interacting effects of land cover and exogenous factors suggest nutrient yields should be treated as distributions, and the effect of land-cover change should be examined by looking for significant changes in the distributions. We compiled nutrient yield distributions from published data. The published data included watersheds with homogeneous land cover that typically reported two or more years of annual nutrient yields for the same watershed. These data were used to construct statistical models, and the models were used to estimate changes in the nutrient yield distributions as a result of land-cover change. Land-cover changes were derived from the National Land Cover Database (NLCD). Total nitrogen (TN) yield distributions increased significantly for 35 of 1550 watersheds and decreased significantly for 51. Total phosphorus (TP) yield distributions increased significantly for 142 watersheds and decreased significantly for 17. The amount of land-cover change required to produce significant shifts in nutrient yield distributions was not constant. Small land-cover changes led to significant shifts in nutrient yield distributions when watersheds were dominated by natural vegetation, whereas much larger land-cover changes were needed to produce significant shifts when watersheds were dominated by urban or agriculture. We discuss our results in the context of the Clean Water Act. PMID:18446405

  15. SUBMERGED MACROPHYTE EFFECTS ON NUTRIENT EXCHANGES IN RIVERINE SEDIMENTS

    EPA Science Inventory

    Submersed macrophytes are important in nutrient cycling in marine and lacustrine systems, although their role in nutrient exchange in tidally-influenced riverine systems is not well studied. In the laboratory, plants significantly lowered porewater nutrient pools of riverine sedi...

  16. Nutrient content of some winter grouse foods

    USGS Publications Warehouse

    Treichler, R.R.; Stow, R.W.; Nelson, A.L.

    1946-01-01

    Seventeen preferred grouse foods were collected during the late winter and analyzed for nutrient content. The results include moisture, crude protein, ether extract, crude fiber, nitrogenfree extract, ash, calcium, phosphorus, and gross energy content expressed both on moisture free and fresh bases.....The preferred winter foods of grouse are characterized by a high content of dry substance and of nitrogen-free extract......On the basis of nutrient content, the foods examined are well qualified as sources of energy and other essential nutrients required for maintenance of grouse during the winter season.

  17. Nutrient profiling of foods: creating a nutrient-rich food index.

    PubMed

    Drewnowski, Adam; Fulgoni, Victor

    2008-01-01

    Nutrient profiling of foods, described as the science of ranking foods based on their nutrient content, is fast becoming the basis for regulating nutrition labels, health claims, and marketing and advertising to children. A number of nutrient profile models have now been developed by research scientists, regulatory agencies, and by the food industry. Whereas some of these models have focused on nutrients to limit, others have emphasized nutrients known to be beneficial to health, or some combination of both. Although nutrient profile models are often tailored to specific goals, the development process ought to follow the same science-driven rules. These include the selection of index nutrients and reference amounts, the development of an appropriate algorithm for calculating nutrient density, and the validation of the chosen nutrient profile model against healthy diets. It is extremely important that nutrient profiles be validated rather than merely compared to prevailing public opinion. Regulatory agencies should act only when they are satisfied that the scientific process has been followed, that the algorithms are transparent, and that the profile model has been validated with respect to objective measures of a healthy diet.

  18. Nutrient Enrichment Increases Mortality of Mangroves

    PubMed Central

    Lovelock, Catherine E.; Ball, Marilyn C.; Martin, Katherine C.; C. Feller, Ilka

    2009-01-01

    Nutrient enrichment of the coastal zone places intense pressure on marine communities. Previous studies have shown that growth of intertidal mangrove forests is accelerated with enhanced nutrient availability. However, nutrient enrichment favours growth of shoots relative to roots, thus enhancing growth rates but increasing vulnerability to environmental stresses that adversely affect plant water relations. Two such stresses are high salinity and low humidity, both of which require greater investment in roots to meet the demands for water by the shoots. Here we present data from a global network of sites that documents enhanced mortality of mangroves with experimental nutrient enrichment at sites where high sediment salinity was coincident with low rainfall and low humidity. Thus the benefits of increased mangrove growth in response to coastal eutrophication is offset by the costs of decreased resilience due to mortality during drought, with mortality increasing with soil water salinity along climatic gradients. PMID:19440554

  19. NRMRL'S NUTRIENT-RELATED RISK MANAGEMENT RESEARCH

    EPA Science Inventory

    Anthropogenic loadings of nutrients into our Nation's atmosphere, aquatic, and terrestrial ecosystems have increased dramatically within the past few decades. Environmental impairments associated with this over fertilization include aquatic habitat loss due to low dissolved oxyge...

  20. Ocean chemistry: Fingerprints of a trace nutrient

    NASA Astrophysics Data System (ADS)

    Resing, Joseph A.; Barrett, Pamela M.

    2014-07-01

    Lack of dissolved iron in the sea limits biological productivity and the uptake of carbon dioxide. The sources of dissolved iron in the North Atlantic Ocean have been identified from isotopic variations of this trace nutrient. See Letter p.212

  1. 21 CFR 107.10 - Nutrient information.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Do. Manganese Micrograms. Copper Do. Iodine Do. Sodium Milligrams. Potassium Do. Chloride Do. (b) In... iodine and sodium, provided that any additionally declared nutrient (i) has been identified as...

  2. 21 CFR 107.10 - Nutrient information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Do. Manganese Micrograms. Copper Do. Iodine Do. Sodium Milligrams. Potassium Do. Chloride Do. (b) In... iodine and sodium, provided that any additionally declared nutrient (i) has been identified as...

  3. 21 CFR 107.10 - Nutrient information.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Do. Manganese Micrograms. Copper Do. Iodine Do. Sodium Milligrams. Potassium Do. Chloride Do. (b) In... iodine and sodium, provided that any additionally declared nutrient (i) has been identified as...

  4. 21 CFR 107.10 - Nutrient information.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Do. Manganese Micrograms. Copper Do. Iodine Do. Sodium Milligrams. Potassium Do. Chloride Do. (b) In... iodine and sodium, provided that any additionally declared nutrient (i) has been identified as...

  5. NUTRIENTS IN WATERSHEDS: DEVELOPING ENHANCED MODELING TOOLS

    EPA Science Inventory

    Nutrient enrichment is one of the most important stressors causing water-resource impairment. These impairments are causing devastating changes: 1) high nitrate concentrations have rendered the groundwaters and reservoirs in many regions impotable -- especially in the rural area...

  6. Recovery of agricultural nutrients from biorefineries.

    PubMed

    Carey, Daniel E; Yang, Yu; McNamara, Patrick J; Mayer, Brooke K

    2016-09-01

    This review lays the foundation for why nutrient recovery must be a key consideration in design and operation of biorefineries and comprehensively reviews technologies that can be used to recover an array of nitrogen, phosphorus, and/or potassium-rich products of relevance to agricultural applications. Recovery of these products using combinations of physical, chemical, and biological operations will promote sustainability at biorefineries by converting low-value biomass (particularly waste material) into a portfolio of higher-value products. These products can include a natural partnering of traditional biorefinery outputs such as biofuels and chemicals together with nutrient-rich fertilizers. Nutrient recovery not only adds an additional marketable biorefinery product, but also avoids the negative consequences of eutrophication, and helps to close anthropogenic nutrient cycles, thereby providing an alternative to current unsustainable approaches to fertilizer production, which are energy-intensive and reliant on nonrenewable natural resource extraction.

  7. MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS

    EPA Science Inventory

    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...

  8. Nutrient limitation and stoichiometry of carnivorous plants.

    PubMed

    Ellison, A M

    2006-11-01

    The cost-benefit model for the evolution of carnivorous plants posits a trade-off between photosynthetic costs associated with carnivorous structures and photosynthetic benefits accrued through additional nutrient acquisition. The model predicts that carnivory is expected to evolve if its marginal benefits exceed its marginal costs. Further, the model predicts that when nutrients are scarce but neither light nor water is limiting, carnivorous plants should have an energetic advantage in competition with non-carnivorous plants. Since the publication of the cost-benefit model over 20 years ago, marginal photosynthetic costs of carnivory have been demonstrated but marginal photosynthetic benefits have not. A review of published data and results of ongoing research show that nitrogen, phosphorus, and potassium often (co-)limit growth of carnivorous plants and that photosynthetic nutrient use efficiency is 20 - 50 % of that of non-carnivorous plants. Assessments of stoichiometric relationships among limiting nutrients, scaling of leaf mass with photosynthesis and nutrient content, and photosynthetic nutrient use efficiency all suggest that carnivorous plants are at an energetic disadvantage relative to non-carnivorous plants in similar habitats. Overall, current data support some of the predictions of the cost-benefit model, fail to support others, and still others remain untested and merit future research. Rather than being an optimal solution to an adaptive problem, botanical carnivory may represent a set of limited responses constrained by both phylogenetic history and environmental stress.

  9. Nutrient limitation and stoichiometry of carnivorous plants.

    PubMed

    Ellison, A M

    2006-11-01

    The cost-benefit model for the evolution of carnivorous plants posits a trade-off between photosynthetic costs associated with carnivorous structures and photosynthetic benefits accrued through additional nutrient acquisition. The model predicts that carnivory is expected to evolve if its marginal benefits exceed its marginal costs. Further, the model predicts that when nutrients are scarce but neither light nor water is limiting, carnivorous plants should have an energetic advantage in competition with non-carnivorous plants. Since the publication of the cost-benefit model over 20 years ago, marginal photosynthetic costs of carnivory have been demonstrated but marginal photosynthetic benefits have not. A review of published data and results of ongoing research show that nitrogen, phosphorus, and potassium often (co-)limit growth of carnivorous plants and that photosynthetic nutrient use efficiency is 20 - 50 % of that of non-carnivorous plants. Assessments of stoichiometric relationships among limiting nutrients, scaling of leaf mass with photosynthesis and nutrient content, and photosynthetic nutrient use efficiency all suggest that carnivorous plants are at an energetic disadvantage relative to non-carnivorous plants in similar habitats. Overall, current data support some of the predictions of the cost-benefit model, fail to support others, and still others remain untested and merit future research. Rather than being an optimal solution to an adaptive problem, botanical carnivory may represent a set of limited responses constrained by both phylogenetic history and environmental stress. PMID:17203429

  10. Nutrient additions to mitigate for loss of Pacific salmon: consequences for stream biofilm and nutrient dynamics

    USGS Publications Warehouse

    Marcarelli, Amy M.; Baxter, Colden V.; Wipfli, Mark S.

    2014-01-01

    Mitigation activities designed to supplement nutrient and organic matter inputs to streams experiencing decline or loss of Pacific salmon typically presuppose that an important pathway by which salmon nutrients are moved to fish (anadromous and/or resident) is via nutrient incorporation by biofilms and subsequent bottom-up stimulation of biofilm production, which is nutrient-limited in many ecosystems where salmon returns have declined. Our objective was to quantify the magnitude of nutrient incorporation and biofilm dynamics that underpin this indirect pathway in response to experimental additions of salmon carcasses and pelletized fish meal (a.k.a., salmon carcass analogs) to 500-m reaches of central Idaho streams over three years. Biofilm standing crops increased 2–8-fold and incorporated marine-derived nutrients (measured using 15N and 13C) in the month following treatment, but these responses did not persist year-to-year. Biofilms were nitrogen (N) limited before treatments, and remained N limited in analog, but not carcass-treated reaches. Despite these biofilm responses, in the month following treatment total N load was equal to 33–47% of the N added to the treated reaches, and N spiraling measurements suggested that as much as 20%, but more likely 2–3% of added N was taken up by microbes. Design of biologically and cost-effective strategies for nutrient addition will require understanding the rates at which stream microbes take up nutrients and the downstream distance traveled by exported nutrients.

  11. Effects of nutrient loading on Anabaena flos-aquae biofilm: biofilm growth and nutrient removals.

    PubMed

    Li, Xiaowei; Wei, Qun; Tu, Xiaojie; Zhu, Yuxuan; Chen, Yanfei; Guo, Lina; Zhou, Jun; Sun, Hongyun

    2016-01-01

    Effects of three different nutrient loadings (low nutrient loading, medium nutrient loading and high nutrient loading, denoted as LNS, MNS and HNS, respectively) on the structure and functions of algal biofilm using Anabaena flos-aquae were investigated using synthetic wastewater. Nutrients removal efficiencies, biofilm thickness, microalgae dehydrogenase activity (DHA) and exopolysaccharide (EPS) productions were examined. Results showed that the changes of nutrient concentration were insignificant after 4 days of experiment for the case of HNS condition; 9 days for the case of MNS condition, and 6 days for the case of LNS condition, respectively. The biofilm thickness, nutrient removal efficiencies, algae DHA and EPS productions increased with the increase of nutrient loadings in synthetic wastewater. For the case of HNS condition, the microalgal biofilm exhibited the best performance in terms of C, N and P removal efficiencies, reaching the removal rates of 68.45, 3.56 and 1.61 mg·L(-1)·d(-1) for C, N, P, respectively. This was likely because, fact with the high nutrient loading, the high biological activity could be achieved, thus resulting in high nutrient removals. The thickness of the biofilm in HNS condition was 75 μm, which was closely related to EPS production. DHA and EPS concentrations were 7.24 and 1.8 × 10(-2) mg·mm(-2), respectively. It was also shown that apart from the nutrient loading, the structure and functions of microalgal biofilm were also influenced by other factors, such as illumination and temperature. PMID:27438243

  12. Variation in nutrients formulated and nutrients supplied on 5 California dairies.

    PubMed

    Rossow, H A; Aly, S S

    2013-01-01

    Computer models used in ration formulation assume that nutrients supplied by a ration formulation are the same as the nutrients presented in front of the cow in the final ration. Deviations in nutrients due to feed management effects such as dry matter changes (i.e., rain), loading, mixing, and delivery errors are assumed to not affect delivery of nutrients to the cow and her resulting milk production. To estimate how feed management affects nutrients supplied to the cow and milk production, and determine if nutrients can serve as indexes of feed management practices, weekly total mixed ration samples were collected and analyzed for 4 pens (close-up cows, fresh cows, high-milk-producing, and low-milk-producing cows, if available) for 7 to 12 wk on 5 commercial California dairies. Differences among nutrient analyses from these samples and nutrients from the formulated rations were analyzed by PROC MIXED of SAS (SAS Institute Inc., Cary, NC). Milk fat and milk protein percentages did not vary as much [coefficient of variation (CV) = 18 to 33%] as milk yield (kg; CV = 16 to 47 %) across all dairies and pens. Variability in nutrients delivered were highest for macronutrient fat (CV = 22%), lignin (CV = 15%), and ash (CV = 11%) percentages and micronutrients Fe (mg/kg; CV = 48%), Na (%; CV = 42%), and Zn (mg/kg; CV = 38%) for the milking pens across all dairies. Partitioning of the variability in random effects of nutrients delivered and intraclass correlation coefficients showed that variability in lignin percentage of TMR had the highest correlation with variability in milk yield and milk fat percentage, followed by fat and crude protein percentages. But, variability in ash, fat, and lignin percentages of total mixed ration had the highest correlation with variability in milk protein percentage. Therefore, lignin, fat, and ash may be the best indices of feed management to include effects of variability in nutrients on variability in milk yield, milk fat, and milk

  13. Nutrient omission in Bt cotton affects soil organic carbon and nutrients status

    NASA Astrophysics Data System (ADS)

    Aladakatti, Y. R.; Biradar, D. P.; Satyanarayana, T.; Majumdar, K.; Shivamurthy, D.

    2012-04-01

    Studies carried out at the University of Agricultural Sciences, Dharwad, India, in medium black soils assessed the effect of nutrient omission in Bt cotton and its effect on the soil organic carbon (SOC) and available nutrients at the end of second consecutive year of nutrient omission. The study also assessed the extent of contribution of the macro and micronutrients towards seed cotton yield. The experiment consisting 11 treatments omitting a nutrient in each treatment including an absolute control without any nutrients was conducted in a Randomised Block Design with three replications. Cotton crop sufficiently fertilized with macro and micro nutrients (165 : 75 : 120 NPK kg ha-1 and 20 kg each of CaSO4, and MgSO4, 10 kg of S, 20 kg each of ZnSO4, FeSO4 and 0.1 per cent Boron twice as foliar spray) was taken as a standard check to assess the contribution of each nutrient in various nutrient omission treatments. Soils of each treatment were analysed initially and after each crop of cotton for SOC and available nutrient status. Results indicated that the SOC decreased after each crop of cotton in absolute control where no nutrients were applied (0.50 % to 0.38 %) and also in the N omission treatment (0.50 % to 0.35 %). But there was no significant impact of omission of P, K and other nutrients on soil organic carbon. Soil available N, P and K in the soil were reduced as compared to the initial soil status after first and second crop of cotton in the respective treatment where these nutrients were omitted. The soil available N, P and K were reduced to the extent of 61 kg ha-1, 7.1 kg ha-1 and 161.9 kg ha-1 in the respective nutrient omission treatment at end of second crop of cotton as compared to the initial status of these nutrients in the soil. This might be due to the mining of these nutrients from the soil nutrient pool with out addition of these nutrients extraneously. The nutrient status of N, P and K remained almost similar in omission of other nutrients

  14. Modeling the Response of Nutrient Concentrations and Primary Productivity in Lake Michigan to Nutrient Loading Scenarios

    EPA Science Inventory

    A water quality model, LM3 Eutro, will be used to estimate the response of nutrient concentrations and primary productivity in Lake Michigan to nutrient loading scenarios. This work is part of a larger effort, the Future Midwestern landscapes study, that will estimate the produc...

  15. YAQUINA ESTUARY NUTRIENT CRITERIA CASE STUDY: GUIDANCE FOR DEVELOPING NUTRIENT CRITERIA IN THE PACIFIC NORTHWEST

    EPA Science Inventory

    The presentation provides an introduction to the Yaquina Estuary Nutrient Case Study which includes considerations for development of estuarine nutrient criteria in the Pacific Northwest. As part of this effort, a database of historic and recent data has been assembled consistin...

  16. Nutrient Requirements of Domestic Animals, Number 10: Nutrient Requirements of Laboratory Animals. Third Revised Edition, 1978.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Board on Agricultural and Renewable Resources.

    This report deals with the nutrient requirements of seven species of animals used extensively for biomedical research in the United States. Following an introductory chapter of general information on nutrition, chapters are presented on the nutrient requirements of the laboratory rat, mouse, gerbil, guinea pig, hamster, vole, and fishes. Each…

  17. Hardwood seeding root and nutrient parameters for a model of nutrient uptake.

    PubMed

    Kelly, J M; Scarbrough, J D; Mays, P A

    2001-01-01

    Use of mechanistic models is an increasingly accepted way to evaluate complex processes. The Barber-Cushman model provides a means to simulate nutrient uptake once information on root system characteristics, nutrient uptake, and soil nutrient supply are developed. Objectives of this study were to determine during a growing season: (i) root growth for 1-yr-old black cherry (Prunus serotina Ehrh.), northern red oak (Quercus rubra L.), and red maple (Acer rubrum L.) seedlings; (ii) net plant increase in N, P, K, Ca, and Mg; (iii) soil solution and solid phase nutrient concentrations; and (iv) the influence of root growth and soil nutrient supply changes on nutrient uptake using the Barber-Cushman model. Seedlings were grown in pots containing A horizon soil from two forest sites. Measurements were made on five occasions during the growing season. Root growth averaged 41.5 cm d-1 for red maple compared with 28.0 and 16.7 cm d-1 for cherry and oak, respectively. Seventy-five percent of root growth occurred at the end of the growing season. Total plant N showed the greatest change (25-58%) due to soil source. Model simulations underestimated observed uptake by 31 to 99%. A clear relationship between soil solution nutrient concentration and plant uptake, an important assumption of the model, was not observed. Results indicate care will need to be exercised in the development and use of root growth and nutrient supply values in mechanistic models. PMID:11285903

  18. Fishing down nutrients on coral reefs

    NASA Astrophysics Data System (ADS)

    Allgeier, Jacob E.; Valdivia, Abel; Cox, Courtney; Layman, Craig A.

    2016-08-01

    Fishing is widely considered a leading cause of biodiversity loss in marine environments, but the potential effect on ecosystem processes, such as nutrient fluxes, is less explored. Here, we test how fishing on Caribbean coral reefs influences biodiversity and ecosystem functions provided by the fish community, that is, fish-mediated nutrient capacity. Specifically, we modelled five processes of nutrient storage (in biomass) and supply (via excretion) of nutrients, as well as a measure of their multifunctionality, onto 143 species of coral reef fishes across 110 coral reef fish communities. These communities span a gradient from extreme fishing pressure to protected areas with little to no fishing. We find that in fished sites fish-mediated nutrient capacity is reduced almost 50%, despite no substantial changes in the number of species. Instead, changes in community size and trophic structure were the primary cause of shifts in ecosystem function. These findings suggest that a broader perspective that incorporates predictable impacts of fishing pressure on ecosystem function is imperative for effective coral reef conservation and management.

  19. Fishing down nutrients on coral reefs.

    PubMed

    Allgeier, Jacob E; Valdivia, Abel; Cox, Courtney; Layman, Craig A

    2016-01-01

    Fishing is widely considered a leading cause of biodiversity loss in marine environments, but the potential effect on ecosystem processes, such as nutrient fluxes, is less explored. Here, we test how fishing on Caribbean coral reefs influences biodiversity and ecosystem functions provided by the fish community, that is, fish-mediated nutrient capacity. Specifically, we modelled five processes of nutrient storage (in biomass) and supply (via excretion) of nutrients, as well as a measure of their multifunctionality, onto 143 species of coral reef fishes across 110 coral reef fish communities. These communities span a gradient from extreme fishing pressure to protected areas with little to no fishing. We find that in fished sites fish-mediated nutrient capacity is reduced almost 50%, despite no substantial changes in the number of species. Instead, changes in community size and trophic structure were the primary cause of shifts in ecosystem function. These findings suggest that a broader perspective that incorporates predictable impacts of fishing pressure on ecosystem function is imperative for effective coral reef conservation and management. PMID:27529748

  20. Microbial life at extremely low nutrient levels

    NASA Astrophysics Data System (ADS)

    Hirsch, P.

    Many microorganisms (``oligotrophs'') grow in distilled water: Pseudomonas spp., Caulobacter spp., Hyphomicrobium spp., Arthrobacter spp., Seliberia spp., Bactoderma alba, Corynebacterium spp., Amycolata (Nocardia) autotrophica, Mycobacterium spp., yeasts, and Chlorella spp. Also, certain lower fungi can be found here. In the laboratory, these organisms thrive on contaminations of the air (CO, hydrocarbons, H2, alcohols etc.). All are euryosmotic and often grow also in higher concentrations of salts and nutrients. Natural locations with extremely low nutrient levels (snow, rain water pools, springs, free ocean water, Antarctic rocks and soils) do not contain more than 1-5 mg/1 of organic carbon. Oligotrophs found here are especially adapted to constant famine: they frequently live attached to surfaces, form polymers and storage products even while starving, and often aggregate. Many of these oligotrophs alter their morphology (surface to volume ratio) with changing nutrient concentrations. Extreme oligotrophs also occur in generally nutrient-rich environments such as sewage aeration tanks or compost soil. Here they are thought to survive in nutrient-depauperate microhabitats.

  1. Fishing down nutrients on coral reefs

    PubMed Central

    Allgeier, Jacob E.; Valdivia, Abel; Cox, Courtney; Layman, Craig A.

    2016-01-01

    Fishing is widely considered a leading cause of biodiversity loss in marine environments, but the potential effect on ecosystem processes, such as nutrient fluxes, is less explored. Here, we test how fishing on Caribbean coral reefs influences biodiversity and ecosystem functions provided by the fish community, that is, fish-mediated nutrient capacity. Specifically, we modelled five processes of nutrient storage (in biomass) and supply (via excretion) of nutrients, as well as a measure of their multifunctionality, onto 143 species of coral reef fishes across 110 coral reef fish communities. These communities span a gradient from extreme fishing pressure to protected areas with little to no fishing. We find that in fished sites fish-mediated nutrient capacity is reduced almost 50%, despite no substantial changes in the number of species. Instead, changes in community size and trophic structure were the primary cause of shifts in ecosystem function. These findings suggest that a broader perspective that incorporates predictable impacts of fishing pressure on ecosystem function is imperative for effective coral reef conservation and management. PMID:27529748

  2. Selected requirements on a sustainable nutrient management.

    PubMed

    Lampert, C

    2003-01-01

    Nutrients are a limited resource and call for management. A sustainable nutrient management strategy reintegrates nutrients in the environment without accumulating harmful substances above an acceptable level. In this study a methodology to assess the environmental compatibility was developed. For this assessment both the (i) enrichment of pollutants in the soils and (ii) the area specific nutrient demand of the crops were taken into account. The method considers, that products applied on soils also contain stable substances, and as a consequence the accumulation of pollutants diminishes. Additionally, it is considered, that increasing substance concentrations in the soil will lead to an increase of substance flows out of the soil by percolation, plant-removal (and erosion). In practice long term management strategies are restricted by the time span considered, the accepted accumulation of substances, the plants real needs and legal constraints. The rating of various goods can be made with the ratio of the added nutrients, considering the pollution criteria, the legal constraints and the plants real needs.

  3. Nutrients affecting brain composition and behavior

    NASA Technical Reports Server (NTRS)

    Wurtman, R. J.

    1987-01-01

    This review examines the changes in brain composition and in various brain functions, including behavior, that can follow the ingestion of particular foods or nutrients. It details those that are best understood: the increases in serotonin, catecholamine, or acetylcholine synthesis that can occur subsequent to food-induced increases in brain levels of tryptophan, tyrosine, or choline; it also discusses the various processes that must intervene between the mouth and the synapse, so to speak, in order for a nutrient to affect neurotransmission, and it speculates as to additional brain chemicals that may ultimately be found to be affected by changes in the availability of their nutrient precursors. Because the brain chemicals best known to be nutrient dependent overlap with those thought to underlie the actions of most of the drugs used to treat psychiatric diseases, knowledge of this dependence may help the psychiatrist to understand some of the pathologic processes occurring in his/her patients, particularly those with appetitive symptoms. At the very least, such knowledge should provide the psychiatrist with objective criteria for judging when to take seriously assertions that particular foods or nutrients do indeed affect behavior (e.g., in hyperactive children). If the food can be shown to alter neurotransmitter release, it may be behaviorally-active; however, if it lacks a discernible neurochemical effect, the likelihood that it really alters behavior is small.

  4. Changes in nutrient structure of river-dominated coastal waters: stoichiometric nutrient balance and its consequences

    NASA Astrophysics Data System (ADS)

    Justić, Dubravko; Rabalais, Nancy N.; Turner, R. Eugene; Dortch, Quay

    We present an analysis of extensive nutrient data sets from two river-dominated coastal ecosystems, the northern Adriatic Sea and the northern Gulf of Mexico, demonstrating significant changes in surface nutrient ratios over a period of 30 years. The silicon:nitrogen ratios have decreased, indicating increased potential for silicon limitation. The nitrogen:phosphorus and the silicon:phosphorus ratios have also changed substantially, and the coastal nutrient structures have become more balanced and potentially less limiting for phytoplankton growth. It is likely that net phytoplankton productivity increased under these conditions and was accompanied by increasing bottom water hypoxia and major changes in community species composition. These findings support the hypothesis that increasing coastal eutrophication to date may be associated with stoichiometric nutrient balance, due to increasing potential for silicon limitation and decreasing potential for nitrogen and phosphorus limitation. On a worldwide basis, coastal ecosystems adjacent to rivers influenced by anthropogenic nutrient loads may experience similar alterations.

  5. Mussel farming as a nutrient reduction measure in the Baltic Sea: consideration of nutrient biogeochemical cycles.

    PubMed

    Stadmark, J; Conley, D J

    2011-07-01

    Nutrient loads from the land to the sea must be reduced to combat coastal eutrophication. It has been suggested that further mitigation efforts are needed in the brackish Baltic Sea to decrease nutrients, especially in eutrophic coastal areas. Mussel farming is a potential measure to remove nutrients directly from the sea. Mussels consume phytoplankton containing nitrogen (N) and phosphorus (P); when the mussels are harvested these nutrients are removed from the aquatic system. However, sedimentation of organic material in faeces and pseudo-faeces below a mussel farm consumes oxygen and can lead to hypoxic or even anoxic sediments causing an increased sediment release of ammonium and phosphate. Moreover, N losses from denitrification can be reduced due to low oxygen and reduced numbers of bioturbating organisms. To reveal if mussel farming is a cost-effective mitigation measure in the Baltic Sea the potential for enhanced sediment nutrient release must be assessed.

  6. Nutrient-dense food groups have high energy costs: an econometric approach to nutrient profiling.

    PubMed

    Maillot, Matthieu; Darmon, Nicole; Darmon, Michel; Lafay, Lionel; Drewnowski, Adam

    2007-07-01

    Consumers wishing to replace some of the foods in their diets with more nutrient-dense options need to be able to identify such foods on the basis of nutrient profiling. The present study used nutrient profiling to rank 7 major food groups and 25 subgroups in terms of their contribution to dietary energy, diet quality, and diet cost for 1332 adult participants in the French National INCA1 Study. Nutrient profiles were based on the presence of 23 qualifying nutrients, expressed as the percentage of nutrient adequacy per 8 MJ, and 3 negative or disqualifying nutrients, expressed as the percentage of the maximal recommended values for saturated fatty acids, added sugar, and sodium per 1.4 kg. Calculated cost of energy (euro/8 MJ) was based on the mean retail price of 619 foods in the nutrient composition database. The meat and the fruit and vegetables food groups had the highest nutritional quality but were associated with highest energy costs. Sweets and salted snacks had the lowest nutritional quality but were also one of the least expensive sources of dietary energy. Starches and grains were unique because they were low in disqualifying nutrients yet provided low-cost dietary energy. Within each major food group, some subgroups had a higher nutritient-to-price ratio than others. However, the fact that food groups with the more favorable nutrient profiles were also associated with higher energy costs suggests that the present structure of food prices may be a barrier to the adoption of food-based dietary guidelines, at least by low-income households.

  7. Exergy analysis of nutrient recovery processes.

    PubMed

    Hellström, D

    2003-01-01

    In an exergy analysis, the actual consumption of resources in physical and chemical processes is calculated. Energy and chemical elements are not consumed in the processes--they are only transformed into other forms with lower quality. The principals of exergy analysis are illustrated by comparing different wastewater treatment systems for nutrient recovery. One system represents an end-of-pipe structure, whereas other systems include source separation of grey water, black water, and urine. The exergy flows analysed in this paper are those related to management and treatment of organic matter and nutrients. The study shows that the total exergy consumption is lowest for the system with source separation of urine and faeces and greatest for the conventional wastewater treatment system complemented by processes for nutrient recovery.

  8. Dietary Restriction and Nutrient Balance in Aging

    PubMed Central

    Leitão-Correia, Fernanda

    2016-01-01

    Dietary regimens that favour reduced calorie intake delay aging and age-associated diseases. New evidences revealed that nutritional balance of dietary components without food restriction increases lifespan. Particular nutrients as several nitrogen sources, proteins, amino acid, and ammonium are implicated in life and healthspan regulation in different model organisms from yeast to mammals. Aging and dietary restriction interact through partially overlapping mechanisms in the activation of the conserved nutrient-signalling pathways, mainly the insulin/insulin-like growth factor (IIS) and the Target Of Rapamycin (TOR). The specific nutrients of dietary regimens, their balance, and how they interact with different genes and pathways are currently being uncovered. Taking into account that dietary regimes can largely influence overall human health and changes in risk factors such as cholesterol level and blood pressure, these new findings are of great importance to fully comprehend the interplay between diet and humans health. PMID:26682004

  9. A comparison of nutrient density scores for 100% fruit juices.

    PubMed

    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.

  10. Nutrient chemistry of River Pinios (Thessalia, Greece).

    PubMed

    Bellos, D; Sawidis, T; Tsekos, I

    2004-03-01

    The impact of human activities with 3-year monitoring on the fluctuation of nutrients along the Pinios River and its tributaries were studied. Their seasonal variations throughout the years 1996-1998 were also presented. High temperatures, from June to August, cause a restriction of the water flow, an enhancement of nutrient concentration with the subsequent increase of eutrophication. High concentrations of nutrients were observed first in winter (wet period), caused by leaching of fertilizers from terrestrial systems after heavy rainfall, later during the warm months due to low water flow of the river, and at last in autumn when plant organisms began to decompose. The intensive algal and macrophyte growth (spring, summer) resulted in severe depletion of nutrients. Organic carbon showed no seasonal trend but its values were high near the estuaries. Nitrate fluxes were high at the initial station (sources) and the Titarisios tributary, whereas nitrites and ammonium were low. In contrary, the Kalentzis tributary with relatively low nitrate values showed increased values of nitrite ammonium or total nitrogen. On the other hand, the Enipeas tributary showed high SO4 values. Phosphates are remarkably present mainly after the city of Larissa, where sewage and industrial discharges occur. None of the nutrients measured in the Pinios River and its tributaries showed a clear seasonal cycle of concentration. Concentrations of nutrients and organic carbon increased as a consequence of anthropogenic inputs, particularly point discharges from sewage treatment plants (i.e. showing distinct, but variable, concentration peaks), as well as diffuse urban and/or agricultural runoff over long areas during storm events. The agricultural management, the urban pollution, mainly from Larissa City, and the climate conditions in the catchment basin (Thessalia Plain) of Pinios River and its tributaries greatly affect the chemical composition of their waters. PMID:14664870

  11. Nutrient limitations to secondary forest regrowth

    NASA Astrophysics Data System (ADS)

    Davidson, Eric A.; Martinelli, Luiz A.

    The old, highly weathered soils of the lowland forest within the Amazon Basin generally exhibit conservative P cycles and leaky N cycles. This generalization applies to mature forests, but accelerating land use change is altering Amazonian landscapes. About 16% of the original forest area has been cleared, and about 160,000 km2 is in secondary forest cover. Secondary forests are common in agricultural regions, but few persist in one place for much more than 5 years. The nutrients within ephemeral forests are important for smallholder traditional slash-and-burn agriculture and in alternatives developed to conserve nutrients. Forest clearing causes an initial loss of nutrients through timber harvesting, fire, erosion, soil gaseous emissions, and hydrologic leaching, with N losses exceeding P losses. In contrast, the Ca, Mg, and K present in woody biomass are largely conserved as ash following fire, redistributing these nutrients to the soil. After the initial postclearing pulse of nutrient availability, rates of N cycling and loss consistently decline as cattle pastures age. Fertilization experiments have demonstrated that growth of young forests in abandoned agricultural land is nutrient limited. Several N cycling indicators in a secondary forest chronosequence study also demonstrated a conservative N cycle in young forests. Variable N limitation in young forests helps explain a negative relationship observed between the burn frequency during previous agricultural phases and the rate of forest regrowth. Recuperation of the N cycle gradually occurs during decades of secondary forest succession, such that mature lowland forests eventually recover abundant N relative to a conservative P cycle.

  12. Nutrient chemistry of River Pinios (Thessalia, Greece).

    PubMed

    Bellos, D; Sawidis, T; Tsekos, I

    2004-03-01

    The impact of human activities with 3-year monitoring on the fluctuation of nutrients along the Pinios River and its tributaries were studied. Their seasonal variations throughout the years 1996-1998 were also presented. High temperatures, from June to August, cause a restriction of the water flow, an enhancement of nutrient concentration with the subsequent increase of eutrophication. High concentrations of nutrients were observed first in winter (wet period), caused by leaching of fertilizers from terrestrial systems after heavy rainfall, later during the warm months due to low water flow of the river, and at last in autumn when plant organisms began to decompose. The intensive algal and macrophyte growth (spring, summer) resulted in severe depletion of nutrients. Organic carbon showed no seasonal trend but its values were high near the estuaries. Nitrate fluxes were high at the initial station (sources) and the Titarisios tributary, whereas nitrites and ammonium were low. In contrary, the Kalentzis tributary with relatively low nitrate values showed increased values of nitrite ammonium or total nitrogen. On the other hand, the Enipeas tributary showed high SO4 values. Phosphates are remarkably present mainly after the city of Larissa, where sewage and industrial discharges occur. None of the nutrients measured in the Pinios River and its tributaries showed a clear seasonal cycle of concentration. Concentrations of nutrients and organic carbon increased as a consequence of anthropogenic inputs, particularly point discharges from sewage treatment plants (i.e. showing distinct, but variable, concentration peaks), as well as diffuse urban and/or agricultural runoff over long areas during storm events. The agricultural management, the urban pollution, mainly from Larissa City, and the climate conditions in the catchment basin (Thessalia Plain) of Pinios River and its tributaries greatly affect the chemical composition of their waters.

  13. Mapping Nutrients Crucial to a Growing Population

    NASA Astrophysics Data System (ADS)

    Tarnowski, J. R.; Cassidy, E. S.; Gerber, J. S.

    2011-12-01

    Over two billion people worldwide suffer from inadequate levels of micronutrients, mainly in the form of iodine, iron, and vitamin A deficiencies. With a growing population, producing crops that contain high amounts of these micronutrients is of increased importance. Addressing these deficiencies sustainably requires a detailed examination of the agricultural production of the micronutrients. The purpose of this study is to determine whether or not enough of these important nutrients are produced to meet the nutritional needs of the global population, and to determine where nutrients are most deficient. We used area specific crop production data to map where and how much iron and vitamin A are produced from major crops.

  14. Effects of Sludge Retention Times on Nutrient Removal and Nitrous Oxide Emission in Biological Nutrient Removal Processes

    PubMed Central

    Li, Bo; Wu, Guangxue

    2014-01-01

    Sludge retention time (SRT) is an important factor affecting not only the performance of the nutrient removal and sludge characteristics, but also the production of secondary pollutants such as nitrous oxide (N2O) in biological nutrient removal (BNR) processes. Four laboratory-scale sequencing batch reactors (SBRs), namely, SBR5, SBR10, SBR20 and SBR40 with the SRT of 5 d, 10 d, 20 d and 40 d, respectively, were operated to examine effects of SRT on nutrient removal, activated sludge characteristics and N2O emissions. The removal of chemical oxygen demand or total phosphorus was similar under SRTs of 5–40 d, SRT mainly affected the nitrogen removal and the optimal SRT for BNR was 20 d. The molecular weight distribution of the effluent organic matters was in the range of 500–3,000 Da under SRTs of 5–40 d. The lowest concentration of the effluent soluble microbial products concentration was obtained at the SRT of 5 d. Nitrifier growth was limited at a short SRT and nitrite existed in the effluent of SBR5. With increasing SRTs, mixed liquor suspended solids concentration increased while the excess sludge production was reduced due to the high endogenous decay rate at high SRTs. Endogenous decay coefficients were 0.020 d−1, 0.036 d−1, 0.037 d−1 and 0.039 d−1 under SRTs of 5–40 d, respectively. In BNR, the N2O emission occurred mainly during the aerobic phase and its emission ratio decreased with increasing SRTs. The ratio between the N2O-N emission and the removed ammonium nitrogen in the aerobic phase was 5%, 3%, 1.8% and 0.8% at the SRT of 5 d, 10 d, 20 d and 40 d, respectively. With low concentrations of dissolved oxygen and high concentrations of oxidized nitrogen, the N2O emission was significantly accelerated due to heterotrophic denitrification activities. PMID:24681555

  15. Nutrient limitation in tropical savannas across multiple scales and mechanisms.

    PubMed

    Pellegrini, Adam F A

    2016-02-01

    Nutrients have been hypothesized to influence the distribution of the savanna biome through two possible mechanisms. Low nutrient availability may restrict growth rates of trees, thereby allowing for intermittent fires to maintain low tree cover; alternatively, nutrient deficiency may even place an absolute constraint on the ability of forests to form, independent of fire. However, we have little understanding of the scales at which nutrient limitation operates, what nutrients are limiting, and the mechanisms that influence how nutrient limitation regulates savanna-forest transitions. Here, I review literature, synthesize existing data, and present a simple calculation of nutrient demand to evaluate how nutrient limitation may regulate the distribution of the savanna biome. The literature primarily supports the hypothesis that nutrients may interact dynamically with fire to restrict the transition of savanna into forest. A compilation of indirect metrics of nutrient limitation suggest that nitrogen and phosphorus are both in short supply and may limit plants. Nutrient demand calculations provided a number of insights. First, trees required high rates of nitrogen and phosphorus supply relative to empirically determined inputs. Second, nutrient demand increased as landscapes approached the transition point between savanna and forest. Third, the potential for fire-driven nutrient losses remained high throughout transitions, which may exaggerate limitation and could be a key feedback stabilizing the savanna biome. Fourth, nutrient limitation varied between functional groups, with fast-growing forest species having substantially greater nutrient demand and a higher susceptibility to fire-driven nutrient losses. Finally, African savanna trees required substantially larger amounts of nutrients supplied at greater rates, although this varied across plant functional groups. In summary, the ability of nutrients to control transitions emerges at individual and landscape

  16. Nutrient limitation in tropical savannas across multiple scales and mechanisms.

    PubMed

    Pellegrini, Adam F A

    2016-02-01

    Nutrients have been hypothesized to influence the distribution of the savanna biome through two possible mechanisms. Low nutrient availability may restrict growth rates of trees, thereby allowing for intermittent fires to maintain low tree cover; alternatively, nutrient deficiency may even place an absolute constraint on the ability of forests to form, independent of fire. However, we have little understanding of the scales at which nutrient limitation operates, what nutrients are limiting, and the mechanisms that influence how nutrient limitation regulates savanna-forest transitions. Here, I review literature, synthesize existing data, and present a simple calculation of nutrient demand to evaluate how nutrient limitation may regulate the distribution of the savanna biome. The literature primarily supports the hypothesis that nutrients may interact dynamically with fire to restrict the transition of savanna into forest. A compilation of indirect metrics of nutrient limitation suggest that nitrogen and phosphorus are both in short supply and may limit plants. Nutrient demand calculations provided a number of insights. First, trees required high rates of nitrogen and phosphorus supply relative to empirically determined inputs. Second, nutrient demand increased as landscapes approached the transition point between savanna and forest. Third, the potential for fire-driven nutrient losses remained high throughout transitions, which may exaggerate limitation and could be a key feedback stabilizing the savanna biome. Fourth, nutrient limitation varied between functional groups, with fast-growing forest species having substantially greater nutrient demand and a higher susceptibility to fire-driven nutrient losses. Finally, African savanna trees required substantially larger amounts of nutrients supplied at greater rates, although this varied across plant functional groups. In summary, the ability of nutrients to control transitions emerges at individual and landscape

  17. Dietary nutrients, additives, and fish health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Disease outbreaks have become a major threat to the sustainability of the aquaculture industry, with antibiotics and chemicals historically used to treat animals ineffective or not allowed to be used today. In this book Dietary Nutrients, Additives, and Fish Health, the relationships between dietar...

  18. Uncertainty Propagation in an Ecosystem Nutrient Budget.

    EPA Science Inventory

    New aspects and advancements in classical uncertainty propagation methods were used to develop a nutrient budget with associated error for a northern Gulf of Mexico coastal embayment. Uncertainty was calculated for budget terms by propagating the standard error and degrees of fr...

  19. Nutrient-induced inflammation in the intestine

    PubMed Central

    Ji, Yong; Sakata, Yasuhisa; Tso, Patrick

    2015-01-01

    Purpose of review To review our current understanding of the relationship between absorption of nutrients and intestinal inflammatory response. Recent findings There is increasing evidence linking gut local inflammatory events with the intake of nutrients. Our recent studies, using the conscious lymph fistula rat model, demonstrate that fat absorption activates the intestinal mucosal mast cells. This is accompanied by a dramatic increase in the lymphatic release of mast cell mediators including histamine, rat mucosal mast cell protease II (RMCPII), as well as the lipid mediator prostaglandin D2 (PGD2). Clinical studies suggest that increased consumption of animal fat may play a role in the pathogenesis of inflammatory bowel disease. This impact of dietary fat may not be restricted to the gut but may extend to the whole body. There is evidence linking a high-fat diet-induced metabolic syndrome, with a low-grade chronic inflammatory state. In this review, we hope to convince the readers that fat absorption can have far reaching physiological and pathophysiological consequences. Summary Understanding the relationship between nutrient absorption and intestinal inflammation is important. We need a better understanding of the interaction between enterocytes and the intestinal immune cells in nutrient absorption and the gut inflammatory responses. PMID:21587069

  20. NUTRIENTS AND EPIGENETICS IN BOVINE CELLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is a chapter for a book titled “Livestock Epigenetics” edited by Dr. Hasan Khatib and published by Wiley-Blackwell. This chapter is focused on the research development in our laboratory in the area of interaction of nutrients and genomic phonotype in bovine cells. Briefly, the Research on nutri...

  1. DETECTING TEMPORAL CHANGE IN WATERSHED NUTRIENT YIELDS

    EPA Science Inventory

    Meta-analyses reveal that nutrient yields tend to be higher for watersheds dominated by anthropogenic uses (e.g., urban, agriculture) and lower for watersheds dominated by natural vegetation. One implication of this pattern is that loss of natural vegetation will produce increase...

  2. Uneven nutrient load and potential offsite loss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Landscape and management often results in uneven nutrient loads within a field. The hypotheses of this study are that: 1) phosphorus accumulates at low areas in the landscape adjacent to waterways; and 2) nitrate at lower landscape positions will be decreased in the subsoil due to denitrification an...

  3. ATMOSPHERIC DEPOSITION MODELING AND MONITORING OF NUTRIENTS

    EPA Science Inventory

    This talk presents an overview of the capabilities and roles that regional atmospheric deposition models can play with respect to multi-media environmental problems. The focus is on nutrient deposition (nitrogen). Atmospheric deposition of nitrogen is an important contributor to...

  4. Grassland productivity limited by multiple nutrients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limitation of aboveground net primary productivity (ANPP) by nitrogen (N) is widely accepted, but the roles of phosphorus (P), potassium (K) and their combinations remain unclear. Thus we may underestimate nutrient limitation of primary productivity. We conducted standardized sampling of ANPP and ...

  5. NUTRIENT RESPONSE IN GREAT LAKES WETLANDS

    EPA Science Inventory

    The U.S. EPA National Health and Environmental Effects Laboratory's Aquatic Stressor Framework and associated Nutrient Implementation Plan define scientific and regulatory needs, and lay-out research goals too for a cross divisional program to investigate stressor-response relati...

  6. Nutrient levels in the Yazoo River Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High nitrogen (N) and phosphorus (P) loadings to aquatic ecosystems are linked to environmental problems including harmful algal blooms and hypoxia. Presented is an assessment of accessible data on nutrient sources, sinks and inputs to streams within the Yazoo River Basin of northern Mississippi. Ac...

  7. Recapturing nutrients from dairy waste using biochar

    NASA Astrophysics Data System (ADS)

    Sarkhot, D.; Ghezzehei, T. A.; Berhe, A. A.

    2009-12-01

    Biochar or biomass derived black carbon is known to be highly resistant to decomposition with half-life periods ranging from hundreds of years to millennia. It is also reported to enhance soil productivity due to high nutrient retention and favorable effects on soil pH, water retention capacity as well as microbial population. Brazilian Terra Preta soils have shown the potential of biochar for long-term carbon sequestration capacity and productivity of soil and many researchers have now focused on utilizing this phenomenon to create fertile, carbon-rich soils, called Terra Preta Nova. Although the highly adsorptive nature of biochar is well characterized, the potential for using biochar in environmental cleanup efforts is relatively unexplored. Dairy waste is a source of significant water pollution because it introduces excess nutrients such as phosphates and nitrates into the soil and water system. Since many soils have limited capacity to retain nitrate and phosphate, especially for long periods of time, the utility of dairy waste manure to enhance soil fertility and nutrient availability to plants is limited. Here, we present results from a project that we started to determine the potential of biochar to recover the excess nutrients from dairy flushed manure. In this initial study, a commercially available biochar amendment was ground and used in a batch sorption experiment with the dairy flushed manure from a local dairy in Merced, California. Four manure dilutions viz. 10, 25, 50 and 100%, and three shaking times, viz. 1, 12 and 24 hours were used for this study. We then calculated the amount of ammonia, nitrate and phosphate adsorbed by the biochar using differences in nutrient concentrations before and after the sorption experiment. Biochar showed significant capacity of adsorbing these nutrients, suggesting a potential for controlling the dairy pollution. The resulting enriched biochar can potentially act as a slow release fertilizer and enhance soil

  8. Nutrient-substituted hydroxyapatites: synthesis and characterization

    NASA Technical Reports Server (NTRS)

    Golden, D. C.; Ming, D. W.

    1999-01-01

    Incorporation of Mg, S, and plant-essential micronutrients into the structure of synthetic hydroxyapatite (HA) may be advantageous for closed-loop systems, such as will be required on Lunar and Martian outposts, because these apatites can be used as slow-release fertilizers. Our objective was to synthesize HA with Ca, P, Mg, S, Fe, Cu, Mn, Zn, Mo, B, and Cl incorporated into the structure, i.e., nutrient-substituted apatites. Hydroxyapatite, carbonate hydroxyapatite (CHA), nutrient-substituted hydroxyapatite (NHA), and nutrient-substituted carbonate hydroxyapatite (NCHA) were synthesized by precipitating from solution. Chemical and mineralogical analysis of precipitated samples indicated a considerable fraction of the added cations were incorporated into HA, without mineral impurities. Particle size of the HA was in the 1 to 40 nm range, and decreased with increased substitution of nutrient elements. The particle shape of HA was elongated in the c-direction in unsubstituted HA and NHA but more spherical in CHA and NCHA. The substitution of cations and anions in the HA structure was confirmed by the decrease of the d[002] spacing of HA with substitution of ions with an ionic radius less than that of Ca or P. The DTPA-extractable Cu ranged from 8 to 8429 mg kg-1, Zn ranged from 57 to 1279 mg kg-1, Fe from 211 to 2573 mg kg-1, and Mn from 190 to 1719 mg kg-1, depending on the substitution level of each element in HA. Nutrient-substituted HA has the potential to be used as a slow-release fertilizer to supply micronutrients, S, and Mg in addition to Ca and P.

  9. Nutrient Status of Adults with Cystic Fibrosis

    PubMed Central

    GORDON, CATHERINE M.; ANDERSON, ELLEN J.; HERLYN, KAREN; HUBBARD, JANE L.; PIZZO, ANGELA; GELBARD, RONDI; LAPEY, ALLEN; MERKEL, PETER A.

    2011-01-01

    Nutrition is thought to influence disease status in patients with cystic fibrosis (CF). This cross-sectional study sought to evaluate nutrient intake and anthropometric data from 64 adult outpatients with cystic fibrosis. Nutrient intake from food and supplements was compared with the Dietary Reference Intakes for 16 nutrients and outcomes influenced by nutritional status. Attention was given to vitamin D and calcium given potential skeletal implications due to cystic fibrosis. Measurements included weight, height, body composition, pulmonary function, and serum metabolic parameters. Participants were interviewed about dietary intake, supplement use, pulmonary function, sunlight exposure, and pain. The participants’ mean body mass index (±standard deviation) was 21.8±4.9 and pulmonary function tests were normal. Seventy-eight percent used pancreatic enzyme replacement for malabsorption. Vitamin D deficiency [25-hydroxyvitamin D (25OHD)<37.5 nmol/L] was common: 25 (39%) were deficient despite adequate vitamin D intake. Lipid profiles were normal in the majority, even though total and saturated fat consumption represented 33.0% and 16.8% of energy intake, respectively. Reported protein intake represented 16.9% of total energy intake (range 10%–25%). For several nutrients, including vitamin D and calcium, intake from food and supplements in many participants exceeded recommended Tolerable Upper Intake Levels. Among adults with cystic fibrosis, vitamin D deficiency was common despite reported adequate intake, and lipid profiles were normal despite a relatively high fat intake. Mean protein consumption was adequate, but the range of intake was concerning, as both inadequate or excessive intake may have deleterious skeletal effects. These findings call into question the applicability of established nutrient thresholds for patients with cystic fibrosis. PMID:18060897

  10. Dairy manure nutrient analysis using quick tests.

    PubMed

    Singh, A; Bicudo, J R

    2005-05-01

    Rapid on-farm assessment of manure nutrient content can be achieved with the use of quick tests. These tests can be used to indirectly measure the nutrient content in animal slurries immediately before manure is applied on agricultural fields. The objective of this study was to assess the reliability of hydrometers, electrical conductivity meter and pens, and Agros N meter against standard laboratory methods. Manure samples were collected from 34 dairy farms in the Mammoth Cave area in central Kentucky. Regression equations were developed for combined and individual counties located In the area (Barren, Hart and Monroe). Our results indicated that accuracy in nutrient estimation could be improved if separate linear regressions were developed for farms with similar facilities in a county. Direct hydrometer estimates of total nitrogen were among the most accurate when separate regression equations were developed for each county (R2 = 0.61, 0.93, and 0.74 for Barren, Hart and Monroe county, respectively). Reasonably accurate estimates (R2 > 0.70) were also obtained for total nitrogen and total phosphorus using hydrometers, either by relating specific gravity to nutrient content or to total solids content. Estimation of ammoniacal nitrogen with Agros N meter and electrical conductivity meter/pens correlated well with standard laboratory determinations, especially while using the individual data sets from Hart County (R2 = 0.70 to 0.87). This study indicates that the use of quick test calibration equations developed for a small area or region where farms are similar in terms of manure handling and management, housing, and feed ration are more appropriate than using "universal" equations usually developed with combined data sets. Accuracy is expected to improve if individual farms develop their own calibration curves. Nevertheless, we suggest confidence intervals always be specified for nutrients estimated through quick testing for any specific region, county, or farm.

  11. Dairy manure nutrient analysis using quick tests.

    PubMed

    Singh, A; Bicudo, J R

    2005-05-01

    Rapid on-farm assessment of manure nutrient content can be achieved with the use of quick tests. These tests can be used to indirectly measure the nutrient content in animal slurries immediately before manure is applied on agricultural fields. The objective of this study was to assess the reliability of hydrometers, electrical conductivity meter and pens, and Agros N meter against standard laboratory methods. Manure samples were collected from 34 dairy farms in the Mammoth Cave area in central Kentucky. Regression equations were developed for combined and individual counties located In the area (Barren, Hart and Monroe). Our results indicated that accuracy in nutrient estimation could be improved if separate linear regressions were developed for farms with similar facilities in a county. Direct hydrometer estimates of total nitrogen were among the most accurate when separate regression equations were developed for each county (R2 = 0.61, 0.93, and 0.74 for Barren, Hart and Monroe county, respectively). Reasonably accurate estimates (R2 > 0.70) were also obtained for total nitrogen and total phosphorus using hydrometers, either by relating specific gravity to nutrient content or to total solids content. Estimation of ammoniacal nitrogen with Agros N meter and electrical conductivity meter/pens correlated well with standard laboratory determinations, especially while using the individual data sets from Hart County (R2 = 0.70 to 0.87). This study indicates that the use of quick test calibration equations developed for a small area or region where farms are similar in terms of manure handling and management, housing, and feed ration are more appropriate than using "universal" equations usually developed with combined data sets. Accuracy is expected to improve if individual farms develop their own calibration curves. Nevertheless, we suggest confidence intervals always be specified for nutrients estimated through quick testing for any specific region, county, or farm

  12. Fire alters ecosystem carbon and nutrients but not plant nutrient stoichiometry or composition in tropical savanna.

    PubMed

    Pellegrini, Adam F A; Hedin, Lars O; Staver, A Carla; Govender, Navashni

    2015-05-01

    Fire and nutrients interact to influence the global distribution and dynamics of the savanna biome, but the results of these interactions are both complex and poorly known. A critical but unresolved question is whether short-term losses of carbon and nutrients caused by fire can trigger long-term and potentially compensatory responses in the nutrient stoichiometry of plants, or in the abundance of dinitrogen-fixing trees. There is disagreement in the literature about the potential role of fire on savanna nutrients, and, in turn, on plant stoichiometry and composition. A major limitation has been the lack of fire manipulations over time scales sufficiently long for these interactions to emerge. We use a 58-year, replicated, large-scale, fire manipulation experiment in Kruger National Park (South Africa) in savanna to quantify the effect of fire on (1) distributions of carbon, nitrogen, and phosphorus at the ecosystem scale; (2) carbon: nitrogen: phosphorus stoichiometry of above- and belowground tissues of plant species; and (3) abundance of plant functional groups including nitrogen fixers. Our results show dramatic effects of fire on the relative distribution of nutrients in soils, but that individual plant stoichiometry and plant community composition remained unexpectedly resilient. Moreover, measures of nutrients and carbon stable isotopes allowed us to discount the role of tree cover change in favor of the turnover of herbaceous biomass as the primary mechanism that mediates a transition from low to high 'soil carbon and nutrients in the absence of fire. We conclude that, in contrast to extra-tropical grasslands or closed-canopy forests, vegetation in the savanna biome may be uniquely adapted to nutrient losses caused by recurring fire.

  13. Nutrient release, recovery and removal from waste sludge of a biological nutrient removal system.

    PubMed

    Wang, Yi; Zheng, Shu-Jian; Pei, Li-Ying; Ke, Li; Peng, Dang-Cong; Xia, Si-Qing

    2014-01-01

    The uncontrolled release of nutrients from waste sludge results in nitrogen and phosphorus overloading in wastewater treatment plants when supernatant is returned to the inlet. A controlled release, recovery and removal of nutrient from the waste sludge of a Biological Nutrient Removal system (BNR) are investigated. Results showed that the supernatant was of high mineral salt, high electrical conductivity and poor biodegradability, in addition to high nitrogen and phosphorus concentrations after the waste sludge was hydrolysed through sodium dodecyl sulphate addition. Subsequently, over 91.8% of phosphorus and 10.5% of nitrogen in the supernatants were extracted by the crystallization method under the conditions of 9.5 pH and 400 rpm. The precipitate was mainly struvite according to X-ray diffraction and morphological examination. A multistage anoxic-oxic Moving Bed Biofilm Reactor (MBBR) was then adopted to remove the residual carbon, nitrogen and phosphorus in the supernatant. The MBBR exhibited good performance in simultaneously removing carbon, nitrogen and phosphorus under a short aeration time, which accounted for 31.25% of a cycle. Fluorescence in situ hybridization analysis demonstrated that nitrifiers presented mainly in floc, although higher extracellular polymeric substance content, especially DNA, appeared in the biofilm. Thus, a combination of hydrolysis and precipitation, followed by the MBBR, can complete the nutrient release from the waste sludge of a BNR system, recovers nutrients from the hydrolysed liquor and removes nutrients from leftovers effectively.

  14. Assessment of Nutrient Stability in Space Foods

    NASA Technical Reports Server (NTRS)

    Zwart, S. R.; Perchonok, M.; Braby, L. A.; Kloeris, V. A.; Smith, S. M.

    2009-01-01

    Maintaining an intact nutrient supply in the food system flown on spacecraft is a critical issue for mission success and crew health and safety. Early polar expeditions and exploration expeditions by sailing vessels have taught us that a deficiency, or excess, of even a single vitamin in the food supply can be catastrophic. Evidence from ground-based research indicates that some vitamins are destroyed and fatty acids are oxidized (and therefore rendered dangerous or useless) by different types of radiation and by conditions of long-term storage. We hypothesize that radiation and long-term storage in the space-flight environment will affect the stability of vitamins, amino acids, and fatty acids in the space food system. The research objectives of our ongoing stability studies are to determine the stability of water- and fat-soluble vitamins, fatty acids, and amino acids in the space food supply before and after space flight on the International Space Station (ISS). Foods were analyzed after 2 weeks (a flight control), 11, 19, and 28 months of flight. Along with the space-flown foods, ground-based controls matched for time, light, and temperature are analyzed. The flight studies complement planned ground-based studies of the effects of radiation on vitamins, amino acids, and fatty acids. Flight studies are needed because a model based on ground-based data cannot predict all of the effects of the space-flight environment. Flight studies provide a more accurate test system to determine the effects on these nutrients of the temperature, and radiation conditions in the space-flight environment. Ground studies are required to evaluate longer missions and higher radiation levels expected outside low-Earth orbit. In addition to providing information about nutrient stability in space, the results of these studies will help NASA determine if a need exists to develop special packaging that can ensure stability of foods and nutrients in space, or if further studies of nutrient

  15. Relating watershed nutrient loads to satellite derived estuarine water quality

    EPA Science Inventory

    Nutrient enhanced phytoplankton production is a cause of degraded estuarine water quality. Yet, relationships between watershed nutrient loads and the spatial and temporal scales of phytoplankton blooms and subsequent water quality impairments remain unquantified for most systems...

  16. [The development of a dispensing cabinet of total nutrient admixture].

    PubMed

    Wu, Xiao-an

    2002-03-01

    A dispensing cabinet of total nutrient admixture is introduced in this paper. Which can be used for nutrient solution dispensing. The clinical application shows that it can provide a practical, simple, safe and satisfactory sterile environment. PMID:16104182

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    Methanogens were grown in media containing bicarbonate buffer, nontronite or montmorillonite clay, and hydrogen gas. No other nutrients were added. These results suggest that martian clays may provide adequate nutrients to support organism growth.

  18. Herbivores and nutrients control grassland plant diversity via light limitation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human alterations to nutrient cycles and herbivore communities are dramatically altering global biodiversity. Theory predicts these changes to be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive excl...

  19. NUTRIENT DYNAMICS IN RELATION TO GEOMORPHOLOGY OF RIVERINE WETLANDS

    EPA Science Inventory

    Variation in water depth and soil properties associated with geomorphic structures can affect riverine wetland nutrient dynamics by altering biogeochemical processes. We examined the seasonal influence of soils and geomorphology on nutrient forms and concentrations in riverine we...

  20. Comparison of Nutrient Drivers and Response Metrics in Oregon Estuaries

    EPA Science Inventory

    With the goal of assessing sensitivity to nutrient enrichment, we present a cross-estuary comparison of nutrient sources, levels, and biological responses (phytoplankton and macroalgae) for thirteen Oregon estuaries. Nitrogen levels in the upstream portions of the estuaries are ...

  1. A compositional analysis approach to phytoplankton composition in coastal Mediterranean wetlands: Influence of salinity and nutrient availability

    NASA Astrophysics Data System (ADS)

    López-Flores, Rocío; Quintana, Xavier D.; Romaní, Anna M.; Bañeras, Lluís; Ruiz-Rueda, Olaya; Compte, Jordi; Green, Andy J.; Egozcue, Juan J.

    2014-01-01

    Mediterranean wetland communities are strongly constrained by hydrological perturbations and the water flow regime. Salinity and nutrient availability have often been considered the most important variables determining changes in the phytoplankton community of coastal wetlands. Ratios between the main environmental variables often have more relevance than the absolute values of each variable; however, in most cases ratios are not suitable for use in multivariate models commonly used by limnologists. The main objective of the present work was to identify the main variables or variable ratios that are the driving forces of the major phytoplankton taxonomic groups in Mediterranean coastal wetlands, using compositional data analysis techniques (CoDa). With this aim, eleven shallow wetlands (6 in Empordà, 5 in Doñana, NE and SW of Spain respectively) were sampled in winter and spring 2007. Two approaches were used: the first one using raw data and the second one using CoDa techniques to transform data. Our results show that differences in hydrological patterns led to three main community assemblages, ranging from communities dominated by typical marine taxa (diatoms and dinoflagellates) when the marine influence was high, to communities dominated by cyanobacteria during confinement and when inorganic nitrogen was scarce. In freshwaters with a high turnover rate, the community was dominated by opportunistic chlorophytes and cryptophytes that need inorganic nitrogen availability. When the raw data and CoDa approaches were compared, the CoDa approach permitted a better ecological interpretation of the phytoplankton community and the main ecological processes. Salinity was the main environmental determinant with both approaches, while the second CoDa RDA axis was related with the balance between the peptidase and phosphatase enzyme activities, confirming the relevance of nutrient retrieval processes in determining phytoplankton composition. We recommend the use of CoDa

  2. Hypothalamic melanin concentrating hormone neurons communicate the nutrient value of sugar

    PubMed Central

    Domingos, Ana I; Sordillo, Aylesse; Dietrich, Marcelo O; Liu, Zhong-Wu; Tellez, Luis A; Vaynshteyn, Jake; Ferreira, Jozelia G; Ekstrand, Mats I; Horvath, Tamas L; de Araujo, Ivan E; Friedman, Jeffrey M

    2013-01-01

    Sugars that contain glucose, such as sucrose, are generally preferred to artificial sweeteners owing to their post-ingestive rewarding effect, which elevates striatal dopamine (DA) release. While the post-ingestive rewarding effect, which artificial sweeteners do not have, signals the nutrient value of sugar and influences food preference, the neural circuitry that mediates the rewarding effect of glucose is unknown. In this study, we show that optogenetic activation of melanin-concentrating hormone (MCH) neurons during intake of the artificial sweetener sucralose increases striatal dopamine levels and inverts the normal preference for sucrose vs sucralose. Conversely, animals with ablation of MCH neurons no longer prefer sucrose to sucralose and show reduced striatal DA release upon sucrose ingestion. We further show that MCH neurons project to reward areas and are required for the post-ingestive rewarding effect of sucrose in sweet-blind Trpm5−/− mice. These studies identify an essential component of the neural pathways linking nutrient sensing and food reward. DOI: http://dx.doi.org/10.7554/eLife.01462.001 PMID:24381247

  3. Application of nutrient intake values (NIVs).

    PubMed

    Vorster, Hester H; Murphy, Suzanne P; Allen, Lindsay H; King, Janet C

    2007-03-01

    The process of applying nutrient intake values (NIVs) for dietary assessment, planning, and implementing programs is discussed in this paper. In addition to assessing, monitoring, and evaluating nutritional situations, applications include planning food policies, strategies, and programs for promotion of optimal nutrition and preventing and treating malnutrition (both over- and undernutrition). Other applications include nutrition education, food and nutrient legislation, marketing and labeling, research, product development, food procurement and trade (import and export), food aid, and therapeutic (clinical) nutrition. Specific examples of how NIVs are used to develop food labels, fortification policies, and food-based dietary guidelines are described. Applications in both developed and developing countries are also described. In summary, NIVs are the scientific backbone of all aspects of nutrition policy in countries and regions worldwide.

  4. Porous membrane utilization in plant nutrient delivery

    NASA Technical Reports Server (NTRS)

    Dreschel, T. W.; Hinkle, C. R.; Prince, R. P.; Knott, W. M., III

    1987-01-01

    A spacecraft hydroponic plant growth unit of tubular configuration, employing a microporous membrane as a capilary interface between plant roots and a nutrient solution, is presented. All three of the experimental trials undertaken successfully grew wheat from seed to harvest. Attention is given to the mass/seed, number of seeds/head, ratio of seed dry mass to total plant dry mass, production of tillers, and mass of seed/plant. Dry matter production is found to be reduced with increasing suction pressure; this is true for both average seed and average total dry matter/plant. This may be due to a reduction in water and nutrient availability through the microporous membrane.

  5. Nutrient supplements boost yeast transformation efficiency

    PubMed Central

    Yu, Sheng-Chun; Dawson, Alexander; Henderson, Alyssa C.; Lockyer, Eloise J.; Read, Emily; Sritharan, Gayathri; Ryan, Marjah; Sgroi, Mara; Ngou, Pok M.; Woodruff, Rosie; Zhang, Ruifeng; Ren Teen Chia, Travis; Liu, Yu; Xiang, Yiyu; Spanu, Pietro D.

    2016-01-01

    Efficiency of yeast transformation is determined by the rate of yeast endocytosis. The aim of this study was to investigate the effect of introducing amino acids and other nutrients (inositol, adenine, or p-aminobenzoic acid) in the transformation medium to develop a highly efficient yeast transformation protocol. The target of rapamycin complex 1 (TORC1) kinase signalling complex influences the rate of yeast endocytosis. TORC signaling is induced by amino acids in the media. Here, we found that increasing the concentration of amino acids and other nutrients in the growth media lead to an increase yeast transformation efficiency up to 107 CFU per μg plasmid DNA and per 108 cells with a 13.8 kb plasmid DNA. This is over 130 times that of current published methods. This improvement may facilitate more efficient experimentation in which transformation efficiency is critical, such as yeast two-hybrid screening. PMID:27760994

  6. Obesity: Interactions of Genome and Nutrients Intake

    PubMed Central

    Doo, Miae; Kim, Yangha

    2015-01-01

    Obesity has become one of the major public health problems all over the world. Recent novel eras of research are opening for the effective management of obesity though gene and nutrient intake interactions because the causes of obesity are complex and multifactorial. Through GWASs (genome-wide association studies) and genetic variations (SNPs, single nucleotide polymorphisms), as the genetic factors are likely to determine individuals’ obesity predisposition. The understanding of genetic approaches in nutritional sciences is referred as “nutrigenomics”. Nutrigenomics explores the interaction between genetic factors and dietary nutrient intake on various disease phenotypes such as obesity. Therefore, this novel approach might suggest a solution for the effective prevention and treatment of obesity through individual genetic profiles and help improve health conditions. PMID:25866743

  7. Land Cover - Nutrient Export Relationships in Space and Time

    EPA Science Inventory

    The relationship between watershed land-cover composition and nutrient export has been well established through several meta-analyses. The meta-analyses reveal that nutrient loads from watersheds dominated by natural vegetation tend to be lower than nutrient loads from watershed...

  8. Nutrient prices and concentrations in midwestern agricultural watersheds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Policies to reduce nutrient emissions from agriculture rest on the assumption that it is very difficult to link inputs on farms to nutrient outputs. As a result, conservation programs fund the installation of best management practices that attempt to avoid, trap, or otherwise control nutrient emissi...

  9. Whole Farm Nutrient Balance Calculator for New York Dairy Farms

    ERIC Educational Resources Information Center

    Soberon, Melanie A.; Ketterings, Quirine M.; Rasmussen, Caroline N.; Czymmek, Karl J.

    2013-01-01

    Nutrient loss and accumulation as well as associated environmental degradation have been a concern for animal agriculture for many decades. Federal and New York (NY) regulations apply to Concentrated Animal Feeding Operations and a comprehensive nutrient management plan (CNMP) is required for regulated farms. The whole farm nutrient mass balance…

  10. Improving Mississippi water quality: CAFO regulations and nutrient TMDLs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Confined Animal Feeding Operations (CAFOs) are regulated to reduce nutrient discharges to local waters, although nutrient water quality standards do not yet exist. At first, it may seem that there is some discontinuity between requiring CAFOs to limit nutrient discharges without knowing what levels...

  11. Nutrient Management Certification for Delaware: Developing a Water Quality Curriculum

    ERIC Educational Resources Information Center

    Hansen, David J.; Binford, Gregory D.

    2004-01-01

    Water quality is a critical environmental, social, and political issue in Delaware. In the late 1990s, a series of events related to water quality issues led to the passage of a state nutrient management law. This new law required nutrient management planning and established a state certification program for nutrient users in the agricultural and…

  12. Artificial Soil With Build-In Plant Nutrients

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W.; Allen, Earl; Henninger, Donald; Golden, D. C.

    1995-01-01

    Nutrients contained in sandlike material. Artificial soil provides nutrients to plants during several growing seasons without need to add fertilizer or nutrient solution. When watered, artificial soil slowly releases all materials a plant needs to grow. Developed as medium for growing crops in space. Also used to grow plants on Earth under controlled conditions or even to augment natural soil.

  13. Developing a web-based forecasting tool for nutrient management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modern nutrient management planning tools provide strategic guidance that, in the best cases, educates farmers and others involved in nutrient management to make prudent management decisions. The strategic guidance provided by nutrient management plans does not provide the day-to-day support require...

  14. Nutrients in the Great Lakes. Teacher's Guide and Student Workbook.

    ERIC Educational Resources Information Center

    Brothers, Chris; And Others

    This teacher guide and student workbook set presents two learning activities, designed for fifth through ninth grade students, that concentrate on nutrients in the Great Lakes. In activity A, students simulate aquatic habitats using lake water and goldfish in glass jars and observe the effects of nutrient loading and nutrient limitation on aquatic…

  15. Seasonal sediment and nutrient transport patterns.

    PubMed

    Moriasi, D N; Guzman, J A; Steiner, J L; Starks, P J; Garbrecht, J D

    2014-07-01

    It is essential to understand sediment and nutrient sources and their spatial and temporal patterns to design effective mitigation strategies. However, long-term data sets to determine sediment and nutrient loadings are scarce and expensive to collect. The goal of this study was to determine seasonal patterns of suspended sediment (SS), total N (TN), and total P (TP) concentrations and loadings for three USGS gauge sites located at the Fort Cobb Reservoir Experimental watershed (FCREW) located in southwestern Oklahoma. Measured instantaneous discharge, SS, TN, and TP concentration data were used to develop lognormal water quality-discharge relationships. The water quality-discharge relationships were used to generate estimated seasonal concentrations and loads based on hourly or 30-min interval discharge. The estimated concentrations and loads were used to determine seasonal patterns for SS, TN, and TP relative to the respective state water quality criteria. Decreasing and increasing monotonic trends were observed for the seasonal time series loads for all three sites, but they were insignificant based on the Spearman test (α = 0.05). The largest loads were estimated during the wet springs and summers. The study SS, TN, and TP target concentrations were exceeded in one season or another. The study results showed that the priority locations to implement the TN and TP conservation practices were the Lake Creek and Willow Creek subwatersheds during the winter and spring seasons. Common practices to mitigate nutrients and suspended sediments include nutrient management, no-till, conversion of cultivated land to pasture, riparian buffers, and animal exclusion.

  16. Seasonal sediment and nutrient transport patterns.

    PubMed

    Moriasi, D N; Guzman, J A; Steiner, J L; Starks, P J; Garbrecht, J D

    2014-07-01

    It is essential to understand sediment and nutrient sources and their spatial and temporal patterns to design effective mitigation strategies. However, long-term data sets to determine sediment and nutrient loadings are scarce and expensive to collect. The goal of this study was to determine seasonal patterns of suspended sediment (SS), total N (TN), and total P (TP) concentrations and loadings for three USGS gauge sites located at the Fort Cobb Reservoir Experimental watershed (FCREW) located in southwestern Oklahoma. Measured instantaneous discharge, SS, TN, and TP concentration data were used to develop lognormal water quality-discharge relationships. The water quality-discharge relationships were used to generate estimated seasonal concentrations and loads based on hourly or 30-min interval discharge. The estimated concentrations and loads were used to determine seasonal patterns for SS, TN, and TP relative to the respective state water quality criteria. Decreasing and increasing monotonic trends were observed for the seasonal time series loads for all three sites, but they were insignificant based on the Spearman test (α = 0.05). The largest loads were estimated during the wet springs and summers. The study SS, TN, and TP target concentrations were exceeded in one season or another. The study results showed that the priority locations to implement the TN and TP conservation practices were the Lake Creek and Willow Creek subwatersheds during the winter and spring seasons. Common practices to mitigate nutrients and suspended sediments include nutrient management, no-till, conversion of cultivated land to pasture, riparian buffers, and animal exclusion. PMID:25603081

  17. Chasing Nutrients with an Arctic Sedge

    NASA Astrophysics Data System (ADS)

    Iverson, S. L.; Schimel, J.

    2013-12-01

    Climate change has put the Arctic into a state of flux. Understanding the effects an altered climate will have on vegetation and nutrient cycling requires more knowledge of the key plant and soil functions of major arctic ecosystems. One of these ecosystems, moist acidic tussock tundra, is dominated by a single plant species, the tussock-forming sedge Eriophorum vaginatum. This plant has unusual underground biomass: long, fast-growing, non-branching, non-mycorrhizal roots. In contrast to many other plants in nutrient-limiting environments, this sedge is highly successful without maximizing its root surface area to volume ratio. The benefits of this growth strategy to the plants and its effects on the accompanying soil-microbe-plant relationships are not fully understood. One possibility is that the roots may help the plant take advantage of nutrients released into the active layer of soil as it thaws in the spring. The roots may also stimulate microbial activity, increasing nutrient turnover and availability. A study was undertaken to explore the nitrogen (N) and carbon (C) dynamics in these plants, as well as the microbial populations associated with active E. vaginatum roots. Intact tussock microcosms (plant and accompanying soil) were removed from the tundra and cultivated in transparent boxes. Half the plants were kept in light to encourage photosynthesis (and thus greater plant activity), while the other half was kept in the dark to inhibit it. Using a 15N isotopic tracer injected at the extremity of root penetration into the soil, the N uptake capacity of E. vaginatum roots at depth was explored. This uptake capacity is compared to measures of plant activity, microbial activity, and soil solution chemistry in order to paint a clearer picture of the role of E. vaginatum in the soil ecosystem.

  18. Qualitative Analysis of Nutrient-Phytoplankton Models

    NASA Astrophysics Data System (ADS)

    Cai, Qinghua; Mohamad, Zakaria; Yuan, Yuan

    2011-11-01

    We propose two nutrient-phytoplankton models with instantaneous and time delayed recyclings, investigate the dynamics and examine the responses to model complexities. We use geometrical and analytical methods to discuss the existence and stability of the possible steady state solutions and study the occurrence of Hopf bifurcation. Numerical simulations illustrate the analytical results and provide further insight into the dynamics of the model, biological interpretations are given.

  19. Impact of nutrients on circadian rhythmicity

    PubMed Central

    Oosterman, Johanneke E.; Kalsbeek, Andries; la Fleur, Susanne E.

    2014-01-01

    The suprachiasmatic nucleus (SCN) in the mammalian hypothalamus functions as an endogenous pacemaker that generates and maintains circadian rhythms throughout the body. Next to this central clock, peripheral oscillators exist in almost all mammalian tissues. Whereas the SCN is mainly entrained to the environment by light, peripheral clocks are entrained by various factors, of which feeding/fasting is the most important. Desynchronization between the central and peripheral clocks by, for instance, altered timing of food intake can lead to uncoupling of peripheral clocks from the central pacemaker and is, in humans, related to the development of metabolic disorders, including obesity and Type 2 diabetes. Diets high in fat or sugar have been shown to alter circadian clock function. This review discusses the recent findings concerning the influence of nutrients, in particular fatty acids and glucose, on behavioral and molecular circadian rhythms and will summarize critical studies describing putative mechanisms by which these nutrients are able to alter normal circadian rhythmicity, in the SCN, in non-SCN brain areas, as well as in peripheral organs. As the effects of fat and sugar on the clock could be through alterations in energy status, the role of specific nutrient sensors will be outlined, as well as the molecular studies linking these components to metabolism. Understanding the impact of specific macronutrients on the circadian clock will allow for guidance toward the composition and timing of meals optimal for physiological health, as well as putative therapeutic targets to regulate the molecular clock. PMID:25519730

  20. Nutrient Addition Dramatically Accelerates Microbial Community Succession

    PubMed Central

    Knelman, Joseph E.; Schmidt, Steven K.; Lynch, Ryan C.; Darcy, John L.; Castle, Sarah C.; Cleveland, Cory C.; Nemergut, Diana R.

    2014-01-01

    The ecological mechanisms driving community succession are widely debated, particularly for microorganisms. While successional soil microbial communities are known to undergo predictable changes in structure concomitant with shifts in a variety of edaphic properties, the causal mechanisms underlying these patterns are poorly understood. Thus, to specifically isolate how nutrients – important drivers of plant succession – affect soil microbial succession, we established a full factorial nitrogen (N) and phosphorus (P) fertilization plot experiment in recently deglaciated (∼3 years since exposure), unvegetated soils of the Puca Glacier forefield in Southeastern Peru. We evaluated soil properties and examined bacterial community composition in plots before and one year after fertilization. Fertilized soils were then compared to samples from three reference successional transects representing advancing stages of soil development ranging from 5 years to 85 years since exposure. We found that a single application of +NP fertilizer caused the soil bacterial community structure of the three-year old soils to most resemble the 85-year old soils after one year. Despite differences in a variety of soil edaphic properties between fertilizer plots and late successional soils, bacterial community composition of +NP plots converged with late successional communities. Thus, our work suggests a mechanism for microbial succession whereby changes in resource availability drive shifts in community composition, supporting a role for nutrient colimitation in primary succession. These results suggest that nutrients alone, independent of other edaphic factors that change with succession, act as an important control over soil microbial community development, greatly accelerating the rate of succession. PMID:25050551

  1. Atmospheric fluxes of nutrients onto Singapore Strait.

    PubMed

    Sundarambal, P; Balasubramanian, R; Tkalich, P

    2009-01-01

    In view of recurring forest fires in Southeast Asia (SEA) on a large scale and the abundant rainfall in this tropical region, atmospheric fallout of airborne particles i.e. dry atmospheric deposition (DAD) and wet atmospheric deposition (WAD) of nutrients to the ocean surface are thought to be significant. Currently, limited data sets of atmospheric deposition (AD) exist for tropical ecosystems in the region. Furthermore, there is a lack of reliable experimental data on AD of nitrogen (N) & phosphorus (P) in tropical environments. It is therefore imperative to quantify the AD of macro-nutrients, N and P species in order to estimate their impacts on aquatic and terrestrial ecosystems. In this study, field measurements of nitrite, nitrate, ammonium, total N (TN), phosphate and total P (TP) were made, in both airborne particulate matter and precipitation, from January 2006 to July 2006 in Singapore. These measurements were done to characterize and estimate the difference between DAD and WAD fluxes of N & P to coastal waters. The estimated loadings from DAD and WAD (g/m(2)/year) of TN were 1.011 +/- 0.441 and 7.052 +/- 4.34 and those of TP were 0.187 +/- 0.16 and 0.532 +/- 0.524, respectively. This investigation represents a baseline study to access environmental effects of AD of nutrients on the coastal aquatic ecosystem.

  2. Revised U.S. nutrient management standard

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    A newly revised National Nutrient Management Standard could have "a continental impact on how we use nutrients" on potentially hundreds of millions of acres of farmland in the United States, Dave White, chief of the U.S. Department of Agriculture's Natural Resources Conservation Service (USDA/NRCS), said at a 13 December news briefing. NRCS uses the voluntary standard, which was last updated in 2006, to help producers better manage the application of nutrients—including fertilizers, animal manures, legumes, and crop cover—on agricultural land. Proper application of nitrogen and phosphorous is of particular concern, White said, adding that the new standard has an increased emphasis on the "four R's" of nutrient management: using the right amount of fertilizer and the right source, and applying the fertilizer in the right place at the right time. In addition, he said, the new standard emphasizes a number of technological tools for fertilizer and farmland management that have become available since the last update of the standards.

  3. Invasive aquarium fish transform ecosystem nutrient dynamics.

    PubMed

    Capps, Krista A; Flecker, Alexander S

    2013-10-22

    Trade of ornamental aquatic species is a multi-billion dollar industry responsible for the introduction of myriad fishes into novel ecosystems. Although aquarium invaders have the potential to alter ecosystem function, regulation of the trade is minimal and little is known about the ecosystem-level consequences of invasion for all but a small number of aquarium species. Here, we demonstrate how ecological stoichiometry can be used as a framework to identify aquarium invaders with the potential to modify ecosystem processes. We show that explosive growth of an introduced population of stoichiometrically unique, phosphorus (P)-rich catfish in a river in southern Mexico significantly transformed stream nutrient dynamics by altering nutrient storage and remineralization rates. Notably, changes varied between elements; the P-rich fish acted as net sinks of P and net remineralizers of nitrogen. Results from this study suggest species-specific stoichiometry may be insightful for understanding how invasive species modify nutrient dynamics when their population densities and elemental composition differ substantially from native organisms. Risk analysis for potential aquarium imports should consider species traits such as body stoichiometry, which may increase the likelihood that an invasion will alter the structure and function of ecosystems.

  4. Invasive aquarium fish transform ecosystem nutrient dynamics

    PubMed Central

    Capps, Krista A.; Flecker, Alexander S.

    2013-01-01

    Trade of ornamental aquatic species is a multi-billion dollar industry responsible for the introduction of myriad fishes into novel ecosystems. Although aquarium invaders have the potential to alter ecosystem function, regulation of the trade is minimal and little is known about the ecosystem-level consequences of invasion for all but a small number of aquarium species. Here, we demonstrate how ecological stoichiometry can be used as a framework to identify aquarium invaders with the potential to modify ecosystem processes. We show that explosive growth of an introduced population of stoichiometrically unique, phosphorus (P)-rich catfish in a river in southern Mexico significantly transformed stream nutrient dynamics by altering nutrient storage and remineralization rates. Notably, changes varied between elements; the P-rich fish acted as net sinks of P and net remineralizers of nitrogen. Results from this study suggest species-specific stoichiometry may be insightful for understanding how invasive species modify nutrient dynamics when their population densities and elemental composition differ substantially from native organisms. Risk analysis for potential aquarium imports should consider species traits such as body stoichiometry, which may increase the likelihood that an invasion will alter the structure and function of ecosystems. PMID:23966642

  5. A computerized procedure for estimating nutrient intake.

    PubMed

    Williamson, M; Azen, C; Acosta, P

    1976-11-01

    A procedure was devised for computing intake in terms of calories, total protein, phenylalanine, carbohydrate, and fat. The procedure used a magnetic tape containing 3,122 numbered food items. The nutrient composition of each food was reported for 100 g of the edible portion of the food. In addition, diet diaries were prepared in which the foods eaten during the preceding 24-hr period, the code for each food corresponding to the number for the same item on the magnetic tape, and the number of units of each food eaten were recorded. A computer program then was written that calculated the amounts of intake per day for each nutrient. Application of the procedure for 42 consecutive days on the daily diet records of 43 adult carriers of the phenylalanine hydroxylase enzyme formed the data base used to determine if aspartame significantly increased levels of phenylalanine in the blood. Adaptations of the procedure permit calculations of intake for periods from 1 to 30 days and analyses of additional nutrients including calcium, phosphorous, iron, vitamin A, thiamine, riboflavin, niacin, and ascorbic acid.

  6. Biotechnology: a solution for improving nutrient bioavailability.

    PubMed

    King, Janet C

    2002-01-01

    Biotechnology strategies are now available to improve the amount and availability of nutrients in plant crops. Those strategies include simple plant selection for varieties with high nutrient density in the seeds, cross-breeding for incorporating a desired trait within a plant, and genetic engineering to manipulate the nutrient content of the plant. In plant cross-breeding, all genes of the parent plants are combined and the progeny have both desirable and undesirable traits. To eliminate undesirable traits, plant breeders "back-cross" the new plant varieties with other plants over several generations. This technique, called hybridization, has been used to create varieties of low-phytate corn, barley, and rice. Using the techniques of genetic engineering, the gene(s) encoding for a desired trait(s) in a plant are introduced in a precise and controlled manner within a relatively short period of time. Golden rice, containing carotenoids, and rice with higher amounts of iron, are two examples of genetically engineered plants for improved nutrition. Genetic engineering has tremendous potential for revolutionizing nutrition. However, public concerns regarding safety, appearance, and ethics must be overcome before these products can be effectively introduced into the food supply.

  7. Yield Gap, Indigenous Nutrient Supply and Nutrient Use Efficiency for Maize in China

    PubMed Central

    Xu, Xinpeng; Liu, Xiaoyan; He, Ping; Johnston, Adrian M.; Zhao, Shicheng; Qiu, Shaojun; Zhou, Wei

    2015-01-01

    Great achievements have been attained in agricultural production of China, while there are still many difficulties and challenges ahead that call for put more efforts to overcome to guarantee food security and protect environment simultaneously. Analyzing yield gap and nutrient use efficiency will help develop and inform agricultural policies and strategies to increase grain yield. On-farm datasets from 2001 to 2012 with 1,971 field experiments for maize (Zea mays L.) were collected in four maize agro-ecological regions of China, and the optimal management (OPT), farmers’ practice (FP), a series of nutrient omission treatments were used to analyze yield gap, nutrient use efficiency and indigenous nutrient supply by adopting meta-analysis and ANOVA analysis. Across all sites, the average yield gap between OPT and FP was 0.7 t ha-1, the yield response to nitrogen (N), phosphorus (P), and potassium (K) were 1.8, 1.0, and 1.2 t ha-1, respectively. The soil indigenous nutrient supply of N, P, and K averaged 139.9, 33.7, and 127.5 kg ha-1, respectively. As compared to FP, the average recovery efficiency (RE) of N, P, and K with OPT increased by percentage point of 12.2, 5.5, and 6.5, respectively. This study indicated that there would be considerable potential to further improve yield and nutrient use efficiency in China, and will help develop and inform agricultural policies and strategies, while some management measures such as soil, plant and nutrient are necessary and integrate with advanced knowledge and technologies. PMID:26484543

  8. Enhanced plant nutrient use efficiency with PGPR and AMF in an integrated nutrient management system.

    PubMed

    Adesemoye, A O; Torbert, H A; Kloepper, J W

    2008-10-01

    A 3 year field study was conducted with field corn from 2005 to 2007 to test the hypothesis that microbial inoculants that increase plant growth and yield can enhance nutrient uptake, and thereby remove more nutrients, especially N, P, and K from the field as part of an integrated nutrient management system. The field trial evaluated microbial inoculants, which include a commercially available plant growth-promoting rhizobacteria (PGPR), arbuscular mycorrhiza fungi (AMF), and their combination across 2 tillage systems (no-till and conventional till) and 2 fertilization regimes (poultry litter and ammonium nitrate). Data were collected on plant height, yield (dry mass of ears and silage), and nutrient content of corn grain and silage. In addition, nutrient content of soil was determined, and bioavailability of soil nutrient was measured with plant root simulator probes. Results showed that inoculants promoted plant growth and yield. For example, grain yields (kg.ha(-1)) in 2007 for inoculants were 7717 for AMF, 7260 for PGPR+AMF, 7313 for PGPR, 5725 for the control group, and for fertilizer were 7470 for poultry litter and 6537 for NH4NO3. Nitrogen content per gram of grain tissues was significantly enhanced in 2006 by inoculant, fertilizer, and their interactions. Significantly higher amounts of N, P, and K were removed from the plots with inoculants, based on total nutrient content of grain per plot. These results supported the overall hypothesis and indicate that application of inoculants can lead to reduction in the build up of N, P, and K in agricultural soils. Further studies should be conducted to combine microbial inoculants with reduced rates of fertilizer.

  9. Yield Gap, Indigenous Nutrient Supply and Nutrient Use Efficiency for Maize in China.

    PubMed

    Xu, Xinpeng; Liu, Xiaoyan; He, Ping; Johnston, Adrian M; Zhao, Shicheng; Qiu, Shaojun; Zhou, Wei

    2015-01-01

    Great achievements have been attained in agricultural production of China, while there are still many difficulties and challenges ahead that call for put more efforts to overcome to guarantee food security and protect environment simultaneously. Analyzing yield gap and nutrient use efficiency will help develop and inform agricultural policies and strategies to increase grain yield. On-farm datasets from 2001 to 2012 with 1,971 field experiments for maize (Zea mays L.) were collected in four maize agro-ecological regions of China, and the optimal management (OPT), farmers' practice (FP), a series of nutrient omission treatments were used to analyze yield gap, nutrient use efficiency and indigenous nutrient supply by adopting meta-analysis and ANOVA analysis. Across all sites, the average yield gap between OPT and FP was 0.7 t ha-1, the yield response to nitrogen (N), phosphorus (P), and potassium (K) were 1.8, 1.0, and 1.2 t ha-1, respectively. The soil indigenous nutrient supply of N, P, and K averaged 139.9, 33.7, and 127.5 kg ha-1, respectively. As compared to FP, the average recovery efficiency (RE) of N, P, and K with OPT increased by percentage point of 12.2, 5.5, and 6.5, respectively. This study indicated that there would be considerable potential to further improve yield and nutrient use efficiency in China, and will help develop and inform agricultural policies and strategies, while some management measures such as soil, plant and nutrient are necessary and integrate with advanced knowledge and technologies. PMID:26484543

  10. Nutrient uptake dynamics across a gradient of nutrient concentrations and ratios at the landscape scale

    NASA Astrophysics Data System (ADS)

    Gibson, Catherine A.; O'Reilly, Catherine M.; Conine, Andrea L.; Lipshutz, Sondra M.

    2015-02-01

    Understanding interactions between nutrient cycles is essential for recognizing and remediating human impacts on water quality, yet multielemental approaches to studying nutrient cycling in streams are currently rare. Here we utilized a relatively new approach (tracer additions for spiraling curve characterization) to examine uptake dynamics for three essential nutrients across a landscape that varied in absolute and relative nutrient availability. We measured nutrient uptake for soluble reactive phosphorous, ammonium-nitrogen, and nitrate-nitrogen in 16 headwater streams in the Catskill Mountains, New York. Across the landscape, ammonium-nitrogen and soluble reactive phosphorus had shorter uptake lengths and higher uptake velocities than nitrate-nitrogen. Ammonium-nitrogen and soluble reactive phosphorus uptake velocities were tightly correlated, and the slope of the relationship did not differ from one, suggesting strong demand for both nutrients despite the high ambient water column dissolved inorganic nitrogen: soluble reactive phosphorus ratios. Ammonium-nitrogen appeared to be the preferred form of nitrogen despite much higher nitrate-nitrogen concentrations. The uptake rate of nitrate-nitrogen was positively correlated with ambient soluble reactive phosphorus concentration and soluble reactive phosphorus areal uptake rate, suggesting that higher soluble reactive phosphorus concentrations alleviate phosphorus limitation and facilitate nitrate-nitrogen uptake. In addition, these streams retained a large proportion of soluble reactive phosphorus, ammonium-nitrogen, and nitrate-nitrogen supplied by the watershed, demonstrating that these streams are important landscape filters for nutrients. Together, these results (1) indicated phosphorus limitation across the landscape but similarly high demand for ammonium-nitrogen and (2) suggested that nitrate-nitrogen uptake was influenced by variability in soluble reactive phosphorus availability and preference for

  11. Yield Gap, Indigenous Nutrient Supply and Nutrient Use Efficiency for Maize in China.

    PubMed

    Xu, Xinpeng; Liu, Xiaoyan; He, Ping; Johnston, Adrian M; Zhao, Shicheng; Qiu, Shaojun; Zhou, Wei

    2015-01-01

    Great achievements have been attained in agricultural production of China, while there are still many difficulties and challenges ahead that call for put more efforts to overcome to guarantee food security and protect environment simultaneously. Analyzing yield gap and nutrient use efficiency will help develop and inform agricultural policies and strategies to increase grain yield. On-farm datasets from 2001 to 2012 with 1,971 field experiments for maize (Zea mays L.) were collected in four maize agro-ecological regions of China, and the optimal management (OPT), farmers' practice (FP), a series of nutrient omission treatments were used to analyze yield gap, nutrient use efficiency and indigenous nutrient supply by adopting meta-analysis and ANOVA analysis. Across all sites, the average yield gap between OPT and FP was 0.7 t ha-1, the yield response to nitrogen (N), phosphorus (P), and potassium (K) were 1.8, 1.0, and 1.2 t ha-1, respectively. The soil indigenous nutrient supply of N, P, and K averaged 139.9, 33.7, and 127.5 kg ha-1, respectively. As compared to FP, the average recovery efficiency (RE) of N, P, and K with OPT increased by percentage point of 12.2, 5.5, and 6.5, respectively. This study indicated that there would be considerable potential to further improve yield and nutrient use efficiency in China, and will help develop and inform agricultural policies and strategies, while some management measures such as soil, plant and nutrient are necessary and integrate with advanced knowledge and technologies.

  12. Stable isotope-labelled feed nutrients to assess nutrient-specific feed passage kinetics in ruminants.

    PubMed

    Warner, Daniel; Dijkstra, Jan; Hendriks, Wouter H; Pellikaan, Wilbert F

    2014-03-30

    Knowledge of digesta passage kinetics in ruminants is essential to predict nutrient supply to the animal in relation to optimal animal performance, environmental pollution and animal health. Fractional passage rates (FPR) of feed are widely used in modern feed evaluation systems and mechanistic rumen models, but data on nutrient-specific FPR are scarce. Such models generally rely on conventional external marker techniques, which do not always describe digesta passage kinetics in a satisfactory manner. Here the use of stable isotope-labelled dietary nutrients as a promising novel tool to assess nutrient-specific passage kinetics is discussed. Some major limitations of this technique include a potential marker migration, a poor isotope distribution in the labelled feed and a differential disappearance rate of isotopes upon microbial fermentation in non-steady state conditions. Such limitations can often be circumvented by using intrinsically stable isotope-labelled plant material. Data are limited but indicate that external particulate markers overestimate rumen FPR of plant fibre compared with the internal stable isotope markers. Stable isotopes undergo the same digestive mechanism as the labelled feed components and are thus of particular interest to specifically measure passage kinetics of digestible dietary nutrients.

  13. Nutrient sensing and signaling in the yeast Saccharomyces cerevisiae

    PubMed Central

    Conrad, Michaela; Schothorst, Joep; Kankipati, Harish Nag; Van Zeebroeck, Griet; Rubio-Texeira, Marta; Thevelein, Johan M

    2014-01-01

    The yeast Saccharomyces cerevisiae has been a favorite organism for pioneering studies on nutrient-sensing and signaling mechanisms. Many specific nutrient responses have been elucidated in great detail. This has led to important new concepts and insight into nutrient-controlled cellular regulation. Major highlights include the central role of the Snf1 protein kinase in the glucose repression pathway, galactose induction, the discovery of a G-protein-coupled receptor system, and role of Ras in glucose-induced cAMP signaling, the role of the protein synthesis initiation machinery in general control of nitrogen metabolism, the cyclin-controlled protein kinase Pho85 in phosphate regulation, nitrogen catabolite repression and the nitrogen-sensing target of rapamycin pathway, and the discovery of transporter-like proteins acting as nutrient sensors. In addition, a number of cellular targets, like carbohydrate stores, stress tolerance, and ribosomal gene expression, are controlled by the presence of multiple nutrients. The protein kinase A signaling pathway plays a major role in this general nutrient response. It has led to the discovery of nutrient transceptors (transporter receptors) as nutrient sensors. Major shortcomings in our knowledge are the relationship between rapid and steady-state nutrient signaling, the role of metabolic intermediates in intracellular nutrient sensing, and the identity of the nutrient sensors controlling cellular growth. PMID:24483210

  14. Nutrient sensing and signaling in the yeast Saccharomyces cerevisiae.

    PubMed

    Conrad, Michaela; Schothorst, Joep; Kankipati, Harish Nag; Van Zeebroeck, Griet; Rubio-Texeira, Marta; Thevelein, Johan M

    2014-03-01

    The yeast Saccharomyces cerevisiae has been a favorite organism for pioneering studies on nutrient-sensing and signaling mechanisms. Many specific nutrient responses have been elucidated in great detail. This has led to important new concepts and insight into nutrient-controlled cellular regulation. Major highlights include the central role of the Snf1 protein kinase in the glucose repression pathway, galactose induction, the discovery of a G-protein-coupled receptor system, and role of Ras in glucose-induced cAMP signaling, the role of the protein synthesis initiation machinery in general control of nitrogen metabolism, the cyclin-controlled protein kinase Pho85 in phosphate regulation, nitrogen catabolite repression and the nitrogen-sensing target of rapamycin pathway, and the discovery of transporter-like proteins acting as nutrient sensors. In addition, a number of cellular targets, like carbohydrate stores, stress tolerance, and ribosomal gene expression, are controlled by the presence of multiple nutrients. The protein kinase A signaling pathway plays a major role in this general nutrient response. It has led to the discovery of nutrient transceptors (transporter receptors) as nutrient sensors. Major shortcomings in our knowledge are the relationship between rapid and steady-state nutrient signaling, the role of metabolic intermediates in intracellular nutrient sensing, and the identity of the nutrient sensors controlling cellular growth.

  15. Anthropogenic nutrients and harmful algae in coastal waters.

    PubMed

    Davidson, Keith; Gowen, Richard J; Harrison, Paul J; Fleming, Lora E; Hoagland, Porter; Moschonas, Grigorios

    2014-12-15

    Harmful algal blooms (HABs) are thought to be increasing in coastal waters worldwide. Anthropogenic nutrient enrichment has been proposed as a principal causative factor of this increase through elevated inorganic and/or organic nutrient concentrations and modified nutrient ratios. We assess: 1) the level of understanding of the link between the amount, form and ratio of anthropogenic nutrients and HABs; 2) the evidence for a link between anthropogenically generated HABs and negative impacts on human health; and 3) the economic implications of anthropogenic nutrient/HAB interactions. We demonstrate that an anthropogenic nutrient-HAB link is far from universal, and where it has been demonstrated, it is most frequently associated with high biomass rather than low biomass (biotoxin producing) HABs. While organic nutrients have been shown to support the growth of a range of HAB species, insufficient evidence exists to clearly establish if these nutrients specifically promote the growth of harmful species in preference to benign ones, or if/how they influence toxicity of harmful species. We conclude that the role of anthropogenic nutrients in promoting HABs is site-specific, with hydrodynamic processes often determining whether blooms occur. We also find a lack of evidence of widespread significant adverse health impacts from anthropogenic nutrient-generated HABs, although this may be partly due to a lack of human/animal health and HAB monitoring. Detailed economic evaluation and cost/benefit analysis of the impact of anthropogenically generated HABs, or nutrient reduction schemes to alleviate them, is also frequently lacking.

  16. Anthropogenic nutrients and harmful algae in coastal waters.

    PubMed

    Davidson, Keith; Gowen, Richard J; Harrison, Paul J; Fleming, Lora E; Hoagland, Porter; Moschonas, Grigorios

    2014-12-15

    Harmful algal blooms (HABs) are thought to be increasing in coastal waters worldwide. Anthropogenic nutrient enrichment has been proposed as a principal causative factor of this increase through elevated inorganic and/or organic nutrient concentrations and modified nutrient ratios. We assess: 1) the level of understanding of the link between the amount, form and ratio of anthropogenic nutrients and HABs; 2) the evidence for a link between anthropogenically generated HABs and negative impacts on human health; and 3) the economic implications of anthropogenic nutrient/HAB interactions. We demonstrate that an anthropogenic nutrient-HAB link is far from universal, and where it has been demonstrated, it is most frequently associated with high biomass rather than low biomass (biotoxin producing) HABs. While organic nutrients have been shown to support the growth of a range of HAB species, insufficient evidence exists to clearly establish if these nutrients specifically promote the growth of harmful species in preference to benign ones, or if/how they influence toxicity of harmful species. We conclude that the role of anthropogenic nutrients in promoting HABs is site-specific, with hydrodynamic processes often determining whether blooms occur. We also find a lack of evidence of widespread significant adverse health impacts from anthropogenic nutrient-generated HABs, although this may be partly due to a lack of human/animal health and HAB monitoring. Detailed economic evaluation and cost/benefit analysis of the impact of anthropogenically generated HABs, or nutrient reduction schemes to alleviate them, is also frequently lacking. PMID:25173729

  17. The role of arbuscular mycorrhizas in reducing soil nutrient loss.

    PubMed

    Cavagnaro, Timothy R; Bender, S Franz; Asghari, Hamid R; Heijden, Marcel G A van der

    2015-05-01

    Substantial amounts of nutrients are lost from soils via leaching and as gaseous emissions. These losses can be environmentally damaging and expensive in terms of lost agricultural production. Plants have evolved many traits to optimize nutrient acquisition, including the formation of arbuscular mycorrhizas (AM), associations of plant roots with fungi that acquire soil nutrients. There is emerging evidence that AM have the ability to reduce nutrient loss from soils by enlarging the nutrient interception zone and preventing nutrient loss after rain-induced leaching events. Until recently, this important ecosystem service of AM had been largely overlooked. Here we review the role of AM in reducing nutrient loss and conclude that this role cannot be ignored if we are to increase global food production in an environmentally sustainable manner. PMID:25840500

  18. The role of autophagy in intracellular pathogen nutrient acquisition

    PubMed Central

    Steele, Shaun; Brunton, Jason; Kawula, Thomas

    2015-01-01

    Following entry into host cells intracellular pathogens must simultaneously evade innate host defense mechanisms and acquire energy and anabolic substrates from the nutrient-limited intracellular environment. Most of the potential intracellular nutrient sources are stored within complex macromolecules that are not immediately accessible by intracellular pathogens. To obtain nutrients for proliferation, intracellular pathogens must compete with the host cell for newly-imported simple nutrients or degrade host nutrient storage structures into their constituent components (fatty acids, carbohydrates, and amino acids). It is becoming increasingly evident that intracellular pathogens have evolved a wide variety of strategies to accomplish this task. One recurrent microbial strategy is to exploit host degradative processes that break down host macromolecules into simple nutrients that the microbe can use. Herein we focus on how a subset of bacterial, viral, and eukaryotic pathogens leverage the host process of autophagy to acquire nutrients that support their growth within infected cells. PMID:26106587

  19. Nature of Random Variation in the Nutrient Composition of Meals

    PubMed Central

    Balintfy, Joseph L.; Prekopa, Andras

    1966-01-01

    The mathematical formulation of nutrient variation in meals in presented by means of random vectors. The primary sources of nutrient variation in unit portions of menu items are identified and expressed in terms of random food-nutrient, random portion size and random ingredient composition variations. A secondary source of nutrient variation can be traced to the random selection process of combining menu items into individual meals from multiple choice menus. The separate as well as the joint effect of these sources on the total variation of the nutrient content of meals is described with the aid of variance-covariance matrices. The investigation is concluded with the formulation of multivariate probability statements concerning the adequacy of the nutrient content of meals relative to the distribution of the nutrient requirements over a given population. PMID:5971545

  20. Nutrient flows between ecosystems can destabilize simple food chains.

    PubMed

    Marleau, Justin N; Guichard, Frédéric; Mallard, François; Loreau, Michel

    2010-09-01

    Dispersal of organisms has large effects on the dynamics and stability of populations and communities. However, current metacommunity theory largely ignores how the flows of limiting nutrients across ecosystems can influence communities. We studied a meta-ecosystem model where two autotroph-consumer communities are spatially coupled through the diffusion of the limiting nutrient. We analyzed regional and local stability, as well as spatial and temporal synchrony to elucidate the impacts of nutrient recycling and diffusion on trophic dynamics. We show that nutrient diffusion is capable of inducing asynchronous local destabilization of biotic compartments through a diffusion-induced spatiotemporal bifurcation. Nutrient recycling interacts with nutrient diffusion and influences the susceptibility of the meta-ecosystem to diffusion-induced instabilities. This interaction between nutrient recycling and transport is further shown to depend on ecosystem enrichment. It more generally emphasizes the importance of meta-ecosystem theory for predicting species persistence and distribution in managed ecosystems.

  1. The role of arbuscular mycorrhizas in reducing soil nutrient loss.

    PubMed

    Cavagnaro, Timothy R; Bender, S Franz; Asghari, Hamid R; Heijden, Marcel G A van der

    2015-05-01

    Substantial amounts of nutrients are lost from soils via leaching and as gaseous emissions. These losses can be environmentally damaging and expensive in terms of lost agricultural production. Plants have evolved many traits to optimize nutrient acquisition, including the formation of arbuscular mycorrhizas (AM), associations of plant roots with fungi that acquire soil nutrients. There is emerging evidence that AM have the ability to reduce nutrient loss from soils by enlarging the nutrient interception zone and preventing nutrient loss after rain-induced leaching events. Until recently, this important ecosystem service of AM had been largely overlooked. Here we review the role of AM in reducing nutrient loss and conclude that this role cannot be ignored if we are to increase global food production in an environmentally sustainable manner.

  2. Leaf mineral nutrient remobilization during leaf senescence and modulation by nutrient deficiency

    PubMed Central

    Maillard, Anne; Diquélou, Sylvain; Billard, Vincent; Laîné, Philippe; Garnica, Maria; Prudent, Marion; Garcia-Mina, José-Maria; Yvin, Jean-Claude; Ourry, Alain

    2015-01-01

    Higher plants have to cope with fluctuating mineral resource availability. However, strategies such as stimulation of root growth, increased transporter activities, and nutrient storage and remobilization have been mostly studied for only a few macronutrients. Leaves of cultivated crops (Zea mays, Brassica napus, Pisum sativum, Triticum aestivum, Hordeum vulgare) and tree species (Quercus robur, Populus nigra, Alnus glutinosa) grown under field conditions were harvested regularly during their life span and analyzed to evaluate the net mobilization of 13 nutrients during leaf senescence. While N was remobilized in all plant species with different efficiencies ranging from 40% (maize) to 90% (wheat), other macronutrients (K–P–S–Mg) were mobilized in most species. Ca and Mn, usually considered as having low phloem mobility were remobilized from leaves in wheat and barley. Leaf content of Cu–Mo–Ni–B–Fe–Zn decreased in some species, as a result of remobilization. Overall, wheat, barley and oak appeared to be the most efficient at remobilization while poplar and maize were the least efficient. Further experiments were performed with rapeseed plants subjected to individual nutrient deficiencies. Compared to field conditions, remobilization from leaves was similar (N–S–Cu) or increased by nutrient deficiency (K–P–Mg) while nutrient deficiency had no effect on Mo–Zn–B–Ca–Mn, which seemed to be non-mobile during leaf senescence under field conditions. However, Ca and Mn were largely mobilized from roots (-97 and -86% of their initial root contents, respectively) to shoots. Differences in remobilization between species and between nutrients are then discussed in relation to a range of putative mechanisms. PMID:26029223

  3. Leaf mineral nutrient remobilization during leaf senescence and modulation by nutrient deficiency.

    PubMed

    Maillard, Anne; Diquélou, Sylvain; Billard, Vincent; Laîné, Philippe; Garnica, Maria; Prudent, Marion; Garcia-Mina, José-Maria; Yvin, Jean-Claude; Ourry, Alain

    2015-01-01

    Higher plants have to cope with fluctuating mineral resource availability. However, strategies such as stimulation of root growth, increased transporter activities, and nutrient storage and remobilization have been mostly studied for only a few macronutrients. Leaves of cultivated crops (Zea mays, Brassica napus, Pisum sativum, Triticum aestivum, Hordeum vulgare) and tree species (Quercus robur, Populus nigra, Alnus glutinosa) grown under field conditions were harvested regularly during their life span and analyzed to evaluate the net mobilization of 13 nutrients during leaf senescence. While N was remobilized in all plant species with different efficiencies ranging from 40% (maize) to 90% (wheat), other macronutrients (K-P-S-Mg) were mobilized in most species. Ca and Mn, usually considered as having low phloem mobility were remobilized from leaves in wheat and barley. Leaf content of Cu-Mo-Ni-B-Fe-Zn decreased in some species, as a result of remobilization. Overall, wheat, barley and oak appeared to be the most efficient at remobilization while poplar and maize were the least efficient. Further experiments were performed with rapeseed plants subjected to individual nutrient deficiencies. Compared to field conditions, remobilization from leaves was similar (N-S-Cu) or increased by nutrient deficiency (K-P-Mg) while nutrient deficiency had no effect on Mo-Zn-B-Ca-Mn, which seemed to be non-mobile during leaf senescence under field conditions. However, Ca and Mn were largely mobilized from roots (-97 and -86% of their initial root contents, respectively) to shoots. Differences in remobilization between species and between nutrients are then discussed in relation to a range of putative mechanisms. PMID:26029223

  4. The Impact of Nutrient Inputs from Atmospheric and Riverine Sources on Oceanic Nitrous-oxide

    NASA Astrophysics Data System (ADS)

    Suntharalingam, Parvadha; Buitenhuis, Erik

    2014-05-01

    Nitrous-oxide (N2O) is a major greenhouse gas, and an important agent of stratospheric ozone depletion. Ocean emissions of nitrous-oxide account for over a quarter of present-day global natural N2O emissions to the atmosphere. This marine N2O source results from a combination of nitrification and denitrification reactions associated with the cycling of organic matter in the oxygenated and sub-oxic regions of the ocean. In addition, in intense sub-oxic and anoxic ocean zones, denitrification processes can provide a local sink of nitrous-oxide. It has been suggested that significant shifts in the global ocean-atmosphere N2O flux could result from changes in nutrient inputs to the ocean that stimulate marine productivity and hence influence N2O cycling and the net oceanic source to the atmosphere. In this analysis we employ the NEMO-PlankTOM10 global ocean biogeochemistry model, in conjunction with embedded representations of the ocean N2O cycle, to assess the relative influences, on present-day ocean N2O, of nutrient inputs to the ocean from atmospheric deposition and riverine fluxes. Specifically, we investigate nutrient forcing from contrasting sources including anthropogenic atmospheric deposition of NOy and NHx (Dentener et al 2006), atmospheric dust deposition (Jickells et al. 2005), and riverine inputs of Fe, Si, N, P, and organic and inorganic carbon (da Cunha et al. 2007). Model analyses are used to quantify the relative influences of these separate nutrient inputs on the net oceanic N2O source. We also characterize the uncertainty in our results associated with our modeled representation of N2O by evaluating the sensitivity to a set of empirically-based and process-based parameterizations of the marine N2O cycle.

  5. Prediction of nutrient digestibility and energy concentrations in fresh grass using nutrient composition.

    PubMed

    Stergiadis, S; Allen, M; Chen, X J; Wills, D; Yan, T

    2015-05-01

    Improved nutrient utilization efficiency is strongly related to enhanced economic performance and reduced environmental footprint of dairy farms. Pasture-based systems are widely used for dairy production in certain areas of the world, but prediction equations of fresh grass nutritive value (nutrient digestibility and energy concentrations) are limited. Equations to predict digestible energy (DE) and metabolizable energy (ME) used for grazing cattle have been either developed with cattle fed conserved forage and concentrate diets or sheep fed previously frozen grass, and the majority of them require measurements less commonly available to producers, such as nutrient digestibility. The aim of the present study was therefore to develop prediction equations more suitable to grazing cattle for nutrient digestibility and energy concentrations, which are routinely available at farm level by using grass nutrient contents as predictors. A study with 33 nonpregnant, nonlactating cows fed solely fresh-cut grass at maintenance energy level for 50 wk was carried out over 3 consecutive grazing seasons. Freshly harvested grass of 3 cuts (primary growth and first and second regrowth), 9 fertilizer input levels, and contrasting stage of maturity (3 to 9 wk after harvest) was used, thus ensuring a wide representation of nutritional quality. As a result, a large variation existed in digestibility of dry matter (0.642-0.900) and digestible organic matter in dry matter (0.636-0.851) and in concentrations of DE (11.8-16.7 MJ/kg of dry matter) and ME (9.0-14.1 MJ/kg of dry matter). Nutrient digestibilities and DE and ME concentrations were negatively related to grass neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents but positively related to nitrogen (N), gross energy, and ether extract (EE) contents. For each predicted variable (nutrient digestibilities or energy concentrations), different combinations of predictors (grass chemical composition) were found to be

  6. Prediction of nutrient digestibility and energy concentrations in fresh grass using nutrient composition.

    PubMed

    Stergiadis, S; Allen, M; Chen, X J; Wills, D; Yan, T

    2015-05-01

    Improved nutrient utilization efficiency is strongly related to enhanced economic performance and reduced environmental footprint of dairy farms. Pasture-based systems are widely used for dairy production in certain areas of the world, but prediction equations of fresh grass nutritive value (nutrient digestibility and energy concentrations) are limited. Equations to predict digestible energy (DE) and metabolizable energy (ME) used for grazing cattle have been either developed with cattle fed conserved forage and concentrate diets or sheep fed previously frozen grass, and the majority of them require measurements less commonly available to producers, such as nutrient digestibility. The aim of the present study was therefore to develop prediction equations more suitable to grazing cattle for nutrient digestibility and energy concentrations, which are routinely available at farm level by using grass nutrient contents as predictors. A study with 33 nonpregnant, nonlactating cows fed solely fresh-cut grass at maintenance energy level for 50 wk was carried out over 3 consecutive grazing seasons. Freshly harvested grass of 3 cuts (primary growth and first and second regrowth), 9 fertilizer input levels, and contrasting stage of maturity (3 to 9 wk after harvest) was used, thus ensuring a wide representation of nutritional quality. As a result, a large variation existed in digestibility of dry matter (0.642-0.900) and digestible organic matter in dry matter (0.636-0.851) and in concentrations of DE (11.8-16.7 MJ/kg of dry matter) and ME (9.0-14.1 MJ/kg of dry matter). Nutrient digestibilities and DE and ME concentrations were negatively related to grass neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents but positively related to nitrogen (N), gross energy, and ether extract (EE) contents. For each predicted variable (nutrient digestibilities or energy concentrations), different combinations of predictors (grass chemical composition) were found to be

  7. Relevance of dissolved organic nutrients for the Arctic Ocean nutrient budget

    NASA Astrophysics Data System (ADS)

    Torres-Valdés, Sinhué; Tsubouchi, Takamasa; Davey, Emily; Yashayaev, Igor; Bacon, Sheldon

    2016-06-01

    We ask whether dissolved organic nitrogen (DON) and phosphorus (DOP) could account for previously identified Arctic Ocean (AO) inorganic nutrient budget imbalances. We assess transports to/from the AO by calculating indicative budgets. Marked DON:DOP ratio differences between the Amerasian and Eurasian AO reflect different physical and biogeochemical pathways. DON and DOP are exported to the North Atlantic via Davis Strait potentially being enhanced in transit from Bering Strait. Fram Strait transports are balanced. Barents Sea Opening transports may provide an additional nutrient source to the Barents Sea or may be locked within the wider AO Atlantic Water circulation. Gaps in our knowledge are identified and discussed.

  8. Food labeling: nutrient content claims, expansion of the nutrient content claim "lean". Final rule.

    PubMed

    2007-01-12

    The Food and Drug Administration (FDA) is amending its food labeling regulations for the expanded use of the nutrient content claim "lean" on the labels of foods categorized as "mixed dishes not measurable with a cup" that meet certain criteria for total fat, saturated fat, and cholesterol content. This final rule responds to a nutrient content claim petition submitted by Nestlé Prepared Foods Co. (Nestlé) under the Federal Food, Drug, and Cosmetic Act (the act). This action is also being taken to provide reliable information that would assist consumers in maintaining healthy dietary practices.

  9. Nutrient fluxes through the Humber estuary

    NASA Astrophysics Data System (ADS)

    Sanders, R. J.; Jickells, T.; Malcolm, S.; Brown, J.; Kirkwood, D.; Reeve, A.; Taylor, J.; Horrobin, T.; Ashcroft, C.

    1997-05-01

    The Humber is a large and complex estuarine system on the east coast of England fed by several rivers. Fluxes of dissolved inorganic nutrients to, through and from this estuary over 1990-1993 are estimated from point flux calculations and property salinity plots. Internal nutrient sources and sinks are quantified. Fluxes of nutrients to the system are highly seasonal; fluxes of nitrate and phosphate are dominated by winter flows in the River Trent, the ammonium flux is dominated by the Rivers Aire and Don. The tidal Trent has a large internal source of ammonium, removes about 80% of its dissolved phosphate load and functions as a sink for nitrate. The tidal Ouse has large internal sources of nitrate, phosphate and ammonium, removes over 60% of its dissolved phosphate load, is an overall source of nitrate and a large sink for ammonium. The main estuary, below the confluence of the two tidal river systems, removes about 6% of the phosphate and 50% of the ammonium entering at the confluence or about 50% and 80%, respectively, if internal sources are taken into account. Nitrate behaves conservatively within the main estuary; thus any conversion of ammonium to nitrate is balanced by a nitrate sink of comparable size. Buffering mechanisms in the outer estuary may release phosphate in similar magnitudes to the direct dissolved export. The seasonality in nitrate flux to the system is preserved throughout the system. The seasonality of the phosphate flux to the system is almost eliminated in the lower part of the tidal rivers at the early part of the salinity gradient. This, combined with phosphate buffering, may render the offshore region nitrogen-limited under conditions suitable for algal growth. Overall the Humber system removes 85% of its dissolved phosphate load, and 4% of its dissolved inorganic nitrogen load.

  10. River nutrient loads and catchment size

    USGS Publications Warehouse

    Smith, S.V.; Swaney, D.P.; Buddemeier, R.W.; Scarsbrook, M.R.; Weatherhead, M.A.; Humborg, Christoph; Eriksson, H.; Hannerz, F.

    2005-01-01

    We have used a total of 496 sample sites to calibrate a simple regression model for calculating dissolved inorganic nutrient fluxes via runoff to the ocean. The regression uses the logarithms of runoff and human population as the independent variables and estimates the logarithms of dissolved inorganic nitrogen and phosphorus loading with R 2 values near 0.8. This predictive capability is about the same as has been derived for total nutrient loading with process-based models requiring more detailed information on independent variables. We conclude that population and runoff are robust proxies for the more detailed application, landscape modification, and in-stream processing estimated by more process-based models. The regression model has then been applied to a demonstration data set of 1353 river catchments draining to the sea from the North American continent south of the Canadian border. The geographic extents of these basins were extracted from a 1-km digital elevation model for North America, and both runoff and population were estimated for each basin. Most of the basins (72% of the total) are smaller than 103 km2, and both runoff and population density are higher and more variable among small basins than among larger ones.While total load to the ocean can probably be adequately estimated from large systems only, analysis of the geographic distribution of nutrient loading requires consideration of the small basins, which can exhibit significant hydrologic and demographic heterogeneity between systems over their range even within the same geographic region. High-resolution regional and local analysis is necessary for environmental assessment and management. ?? Springer 2005.

  11. Carnivorous mammals: nutrient digestibility and energy evaluation.

    PubMed

    Clauss, Marcus; Kleffner, Helen; Kienzle, Ellen

    2010-01-01

    Estimating the energy content is the first step in diet formulation, as it determines the amount of food eaten and hence the concentration of nutrients required to meet the animal's requirements. Additionally, being able to estimate the energy content of a diet empirically known to maintain body condition in an animal will facilitate an estimation of maintenance energy requirements. We collated data on nutrient composition of diets fed to captive wild canids, felids, hyenids, mustelids, pinnipeds, and ursids and the digestibility coefficients from the literature (45 species, 74 publications) to test whether differences in protein and fat digestibility could be detected between species groups, and whether approaches suggested for the estimation of dietary metabolizable energy (ME) content in domestic carnivores (NRC [2006] Nutrient requirements of dogs and cats. Washington, DC: National Academy Press.) can be applied to wild carnivores as well. Regressions of digestible protein or fat content vs. the crude protein (CP) or fat content indicated no relevant differences in the digestive physiology between the carnivore groups. For diets based on raw meat, fish, or whole prey, applying the calculation of ME using "Atwater factors" (16.7  kJ/g CP; 16.7  kJ/g nitrogen-free extracts; 37.7  kJ/g crude fat) provided estimates that compared well to experimental results. This study suggests that ME estimation in such diets is feasible without additional digestion trials. For comparative nutrition research, the study implicates that highly digestible diets typically fed in zoos offer little potential to elucidate differences between species or carnivore groups, but research on diets with higher proportions of difficult-to-digest components (fiber, connective tissues) is lacking. PMID:20073050

  12. Nutrient transport by ruminal bacteria: a review.

    PubMed

    Martin, S A

    1994-11-01

    Fermentation pathways have been elucidated for predominant ruminal bacteria, but information is limited concerning the specific transport mechanisms used by these microorganisms for C, energy, and N sources. In addition, it is possible that changes in ruminal environmental conditions could affect transport activity. Five carrier-mediated soluble nutrient transport mechanisms have been identified in bacteria: 1) facilitated diffusion, 2) shock sensitive systems, 3) proton symport, 4) Na+ symport, and the 5) phosphoenolpyruvate phosphotransferase system (PEP-PTS). Several regulatory mechanisms are also involved at the cell membrane to coordinate utilization of different sugars. Recent research has shown that predominant ruminal bacteria are capable of transporting soluble nutrients by several of the mechanisms outlined above. Megasphaera elsdenii, Selenomonas ruminantium, and Streptococcus bovis transport glucose by the PEP-PTS, and S. ruminantium and S. bovis also possess PEP-PTS activity for disaccharides. Glucose PTS activity in S. bovis was highest at a growth pH of 5.0, low glucose concentrations, and a dilution rate of .10 h-1. The cellulolytic ruminal bacterium Fibrobacter succinogenes uses a Na+ symport mechanism for glucose transport that is sensitive to low extracellular pH and ionophores. Sodium also stimulated cellobiose transport by F. succinogenes, and there is evidence for a proton symport in the transport of both arabinose and xylose by S. ruminantium. A chemical gradient of Na+ seems to play an important role in AA transport in several ruminal bacteria. Studying nutrient transport mechanisms in ruminal bacteria will lead to a better understanding of the ruminal fermentation.

  13. Optimizing Nutrient Uptake in Biological Transport Networks

    NASA Astrophysics Data System (ADS)

    Ronellenfitsch, Henrik; Katifori, Eleni

    2013-03-01

    Many biological systems employ complex networks of vascular tubes to facilitate transport of solute nutrients, examples include the vascular system of plants (phloem), some fungi, and the slime-mold Physarum. It is believed that such networks are optimized through evolution for carrying out their designated task. We propose a set of hydrodynamic governing equations for solute transport in a complex network, and obtain the optimal network architecture for various classes of optimizing functionals. We finally discuss the topological properties and statistical mechanics of the resulting complex networks, and examine correspondence of the obtained networks to those found in actual biological systems.

  14. Biological nutrient removal from dairy wastewater

    SciTech Connect

    Danalewich, J.R.; Papagiannis, T.G.; Gerards, R.; Vriens, L.; Belyea, R.; Tumbleson, M.E.; Raskin, L.

    1998-07-01

    The authors developed a synthetic wastewater which closely represents actual milk processing wastewater. The design of this synthetic wastewater was facilitated by the collection of composite wastewater samples from 15 milk processing plants in the Upper Midwest. These samples, milk, and milk products were analyzed for various chemical parameters. Based on these results, they diluted evaporated milk and cottage cheese, as well as a number of dry chemicals to create a synthetic wastewater. The concentrations in the resulting synthetic wastewater matched average concentrations of 15 composite wastewater samples. Four continuous-flow activated sludge treatment systems are currently being operated to evaluate biological nutrient removal using this synthetic wastewater as an influent.

  15. Design of nutrient removal activated sludge systems.

    PubMed

    Manga, J; Ferrer, J; Seco, A; Garcia-Usach, F

    2003-01-01

    A mechanistic mathematical model for nutrient and organic matter removal was used to describe the behavior of a nitrification denitrification enhanced biological phosphorus removal (NDEBPR) system. This model was implemented in a user-friendly software DESASS (design and simulation of activated sludge systems). A 484-L pilot plant was operated to verify the model results. The pilot plant was operated for three years over three different sludge ages. The validity of the model was confirmed with data from the pilot plant. Also, the utility of DESASS as a valuable tool for designing NDEBPR systems was confirmed.

  16. Design of nutrient removal activated sludge systems.

    PubMed

    Manga, J; Ferrer, J; Seco, A; Garcia-Usach, F

    2003-01-01

    A mechanistic mathematical model for nutrient and organic matter removal was used to describe the behavior of a nitrification denitrification enhanced biological phosphorus removal (NDEBPR) system. This model was implemented in a user-friendly software DESASS (design and simulation of activated sludge systems). A 484-L pilot plant was operated to verify the model results. The pilot plant was operated for three years over three different sludge ages. The validity of the model was confirmed with data from the pilot plant. Also, the utility of DESASS as a valuable tool for designing NDEBPR systems was confirmed. PMID:12906279

  17. 4 Rs are not enough: We need 7 Rs for nutrient management and conservation to increase nutrient use efficiency and reduce off-site transport of nutrients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cox (2010) reported that under business as usual, the environmental impacts of nutrient losses from agriculture will not be resolved and that precision conservation and precision regulation are two mechanisms to reduce the environmental impacts of nutrient losses. This is in agreement with the rece...

  18. Noninvasive detection of plant nutrient stress using fiber optic spectrophotometry

    NASA Astrophysics Data System (ADS)

    Chen, Jun-Wei; Asundi, Anand K.; Liew, Oi Wah; Boey, William S. L.

    2001-05-01

    In a previous paper, we described the use of fiber optic spectrophotometry as a non-destructive and sensitive method to detect early symptoms of plant nutrient deficiency. We report further developments of our work on Brassica chinensis var parachinensis (Bailey) showing reproducibility of our data collected at a different seasonal period. Plants at the mid-log growth phase were subjected to nutrient stress by transferring them to nitrate- and calcium- deficient nutrient solution in a standing aerated hydroponic system. After tracking changes in leaf reflectance by FOSpectr for nine days, the plants were returned to complete nutrient solution and their recovery was monitored for a further nine days. The responses of nutrient stressed plants were compared with those grown under complete nutrient solution over the 18-day trial period. We also compared the sensitivity of FOSpectr detection against plant growth measurements vis-a-vis average leaf number and leaf width and show that the former method gave an indication of nutrient stress much earlier than the latter. In addition, this work indicated that while normal and nutrient-stressed plants could not be distinguished within the first 7 days by tracking plant growth indicators, stressed plants did show a clear decline in average leaf number and leaf width in later stages of growth even after the plants were returned to complete nutrient solution. The results further reinforce the need for early detection of nutrient stress, as late remedial action could not reverse the loss in plant growth in later stages of plant development.

  19. Nutrient fluxes at the landscape level and the R* rule

    USGS Publications Warehouse

    Ju, Shu; DeAngelis, Donald L.

    2010-01-01

    Nutrient cycling in terrestrial ecosystems involves not only the vertical recycling of nutrients at specific locations in space, but also biologically driven horizontal fluxes between different areas of the landscape. This latter process can result in net accumulation of nutrients in some places and net losses in others. We examined the effects of such nutrient-concentrating fluxes on the R* rule, which predicts that the species that can survive in steady state at the lowest level of limiting resource, R*, can exclude all competing species. To study the R* rule in this context, we used a literature model of plant growth and nutrient cycling in which both nutrients and light may limit growth, with plants allocating carbon and nutrients between foliage and roots according to different strategies. We incorporated the assumption that biological processes may concentrate nutrients in some parts of the landscape. We assumed further that these processes draw nutrients from outside the zone of local recycling at a rate proportional to the local biomass density. Analysis showed that at sites where there is a sufficient biomass-dependent accumulation of nutrients, the plant species with the highest biomass production rates (roughly corresponding to the best competitors) do not reduce locally available nutrients to a minimum concentration level (that is, minimum R*), as expected from the R* rule, but instead maximize local nutrient concentration. These new results require broadening of our understanding of the relationships between nutrients and vegetation competition on the landscape level. The R* rule is replaced by a more complex criterion that varies across a landscape and reduces to the R* rule only under certain limiting conditions.

  20. Quantitative Nutrient Limitation Analysis of Global Forests by Remote Sensing

    NASA Astrophysics Data System (ADS)

    Lopez, A. M.; Badgley, G. M.; Field, C. B.

    2015-12-01

    Nutrient availability in terrestrial ecosystems may be the primary determinant of the long-term carbon storage capacity of vegetation. Both nutrient availability and carbon storage capacity are highly uncertain and limit our ability to predict atmospheric CO2 concentrations. Terrestrial vegetation, especially forests, play a critical role in regulating the global carbon cycle and Earth's climate by sequestering carbon from the atmosphere. The broad relationship between nutrient availability and increased biomass production can be captured using remotely-sensed spectral information. We develop an approach to estimate total nutrient availability in 848 global forest sites at 1-km spatial resolution by combining the ecological principle of functional convergence with MODIS gross primary productivity (GPP) and evapotranspiration (ET) products from 2000-2013. Convergence in the relationship between maximum GPP and ET of nutrient-rich forests indicate that any sites deviating from this upper-limit are associated with a lower availability of nutrients. This method offers a way to examine the severity, as well as the spatial extent of nutrient limitation at the global scale. We find that the degree to which forests are nutrient limited range between 0% and 81% with an average limitation of 16 ± 17%. Our method agrees with regional nutrient gradients (i.e. SW-NE Amazon), but does not tightly correspond with recently published nutrient limitation classification standards (Fernandez-Martinez et al., 2014). A global terrestrial nutrient limitation map can assist in diagnosing the health of vegetation while removing the necessity for extensive field sampling or local nutrient addition experiments. Further research will expand the study sites to obtain a complete global terrestrial nutrient limitation map.

  1. Nutrients, Microglia Aging, and Brain Aging.

    PubMed

    Wu, Zhou; Yu, Janchun; Zhu, Aiqin; Nakanishi, Hiroshi

    2016-01-01

    As the life expectancy continues to increase, the cognitive decline associated with Alzheimer's disease (AD) becomes a big major issue in the world. After cellular activation upon systemic inflammation, microglia, the resident immune cells in the brain, start to release proinflammatory mediators to trigger neuroinflammation. We have found that chronic systemic inflammatory challenges induce differential age-dependent microglial responses, which are in line with the impairment of learning and memory, even in middle-aged animals. We thus raise the concept of "microglia aging." This concept is based on the fact that microglia are the key contributor to the acceleration of cognitive decline, which is the major sign of brain aging. On the other hand, inflammation induces oxidative stress and DNA damage, which leads to the overproduction of reactive oxygen species by the numerous types of cells, including macrophages and microglia. Oxidative stress-damaged cells successively produce larger amounts of inflammatory mediators to promote microglia aging. Nutrients are necessary for maintaining general health, including the health of brain. The intake of antioxidant nutrients reduces both systemic inflammation and neuroinflammation and thus reduces cognitive decline during aging. We herein review our microglia aging concept and discuss systemic inflammation and microglia aging. We propose that a nutritional approach to controlling microglia aging will open a new window for healthy brain aging. PMID:26941889

  2. Endocytotic uptake of nutrients in carnivorous plants.

    PubMed

    Adlassnig, Wolfram; Koller-Peroutka, Marianne; Bauer, Sonja; Koshkin, Edith; Lendl, Thomas; Lichtscheidl, Irene K

    2012-07-01

    Carnivorous plants trap, digest and absorb animals in order to supplement their mineral nutrition. Nutrients absorbed by the plant include different nitrogen species, phosphate, potassium, trace elements and small organic compounds. Uptake is usually thought to be performed via specific channels, but this study provides evidence that endocytosis is involved as well. Traps of the carnivorous plants Nepenthes coccinea, Nepenthes ventrata, Cephalotus follicularis, Drosophyllum lusitanicum, Drosera capensis, Dionaea muscipula, Aldrovanda vesiculosa, Genlisea violacea × lobata, Sarracenia psittacina and Sarracenia purpurea were stained with methylene blue in order to identify possible sites of uptake. The permeable parts of the traps were incubated with fluorescein isothiocyanate labelled bovine serum albumin (FITC-BSA) and other fluorescent endocytosis markers, combined with the soluble protein BSA or respiratory inhibitors. Uptake was studied by confocal microscopy. In Nepenthes, small fluorescent vesicles became visible 1 h after incubation with FITC-BSA. These vesicles fused to larger compartments within 30 h. A similar behaviour was found in the related genera Drosera, Dionaea, Aldrovanda and Drosophyllum but also in Cephalotus with glands of different evolutionary origin. In Genlisea and Sarracenia, no evidence for endocytosis was found. We propose that in many carnivorous plants, nutrient uptake by carriers is supplemented by endocytosis, which enables absorption and intracellular digestion of whole proteins. The advantage for the plant of reducing secretion of enzymes for extracellular digestion is evident.

  3. Nutrient cycling in bedform induced hyporheic zones

    NASA Astrophysics Data System (ADS)

    Bardini, L.; Boano, F.; Cardenas, M. B.; Revelli, R.; Ridolfi, L.

    2012-05-01

    The hyporheic zone is an ecotone connecting the stream and groundwater ecosystem that plays a significant role for stream biogeochemistry. Water exchange across the stream-sediment interface and biogeochemical reactions in the streambed concur to affect subsurface solute concentrations and eventually nutrient cycling in the fluvial corridor. In this paper we investigate the interplay of hydrological and biogeochemical processes in a duned streambed and their effect on spatial distribution of solutes. We employ a numerical model to simulate the turbulent water flow and the pressure distribution over the dunes, and then to evaluate the flow field and the biogeochemical reactions in the hyporheic sediments. Sensitivity analyses are performed to analyze the influence of hydrological and chemical properties of the system on solute reaction rates. The results demonstrate the effect of stream velocity and sediment permeability on the chemical zonation. Changing sediment permeability as well as stream velocity directly affects the nutrient supply and the residence times in the streambed, thus controlling the reaction rates under the dune. Stream-water quality is also shown to influence the reactive behavior of the sediments. In particular, the availability of dissolved organic carbon determines whether the streambed acts as a net sink or source of nitrate. This study represents a step towards a better understanding of the complex interactions between hydrodynamical and biogeochemical processes in the hyporheic zone.

  4. Placental Nutrient Transport and Intrauterine Growth Restriction

    PubMed Central

    Gaccioli, Francesca; Lager, Susanne

    2016-01-01

    Intrauterine growth restriction refers to the inability of the fetus to reach its genetically determined potential size. Fetal growth restriction affects approximately 5–15% of all pregnancies in the United States and Europe. In developing countries the occurrence varies widely between 10 and 55%, impacting about 30 million newborns per year. Besides having high perinatal mortality rates these infants are at greater risk for severe adverse outcomes, such as hypoxic ischemic encephalopathy and cerebral palsy. Moreover, reduced fetal growth has lifelong health consequences, including higher risks of developing metabolic and cardiovascular diseases in adulthood. Numerous reports indicate placental insufficiency as one of the underlying causes leading to altered fetal growth and impaired placental capacity of delivering nutrients to the fetus has been shown to contribute to the etiology of intrauterine growth restriction. Indeed, reduced expression and/or activity of placental nutrient transporters have been demonstrated in several conditions associated with an increased risk of delivering a small or growth restricted infant. This review focuses on human pregnancies and summarizes the changes in placental amino acid, fatty acid, and glucose transport reported in conditions associated with intrauterine growth restriction, such as maternal undernutrition, pre-eclampsia, young maternal age, high altitude and infection. PMID:26909042

  5. Endocytotic uptake of nutrients in carnivorous plants.

    PubMed

    Adlassnig, Wolfram; Koller-Peroutka, Marianne; Bauer, Sonja; Koshkin, Edith; Lendl, Thomas; Lichtscheidl, Irene K

    2012-07-01

    Carnivorous plants trap, digest and absorb animals in order to supplement their mineral nutrition. Nutrients absorbed by the plant include different nitrogen species, phosphate, potassium, trace elements and small organic compounds. Uptake is usually thought to be performed via specific channels, but this study provides evidence that endocytosis is involved as well. Traps of the carnivorous plants Nepenthes coccinea, Nepenthes ventrata, Cephalotus follicularis, Drosophyllum lusitanicum, Drosera capensis, Dionaea muscipula, Aldrovanda vesiculosa, Genlisea violacea × lobata, Sarracenia psittacina and Sarracenia purpurea were stained with methylene blue in order to identify possible sites of uptake. The permeable parts of the traps were incubated with fluorescein isothiocyanate labelled bovine serum albumin (FITC-BSA) and other fluorescent endocytosis markers, combined with the soluble protein BSA or respiratory inhibitors. Uptake was studied by confocal microscopy. In Nepenthes, small fluorescent vesicles became visible 1 h after incubation with FITC-BSA. These vesicles fused to larger compartments within 30 h. A similar behaviour was found in the related genera Drosera, Dionaea, Aldrovanda and Drosophyllum but also in Cephalotus with glands of different evolutionary origin. In Genlisea and Sarracenia, no evidence for endocytosis was found. We propose that in many carnivorous plants, nutrient uptake by carriers is supplemented by endocytosis, which enables absorption and intracellular digestion of whole proteins. The advantage for the plant of reducing secretion of enzymes for extracellular digestion is evident. PMID:22417315

  6. Nutrient Enrichment Drives Gulf of Mexico Hypoxia

    NASA Astrophysics Data System (ADS)

    Boesch, Donald F.; Boynton, Walter R.; Crowder, Larry B.; Diaz, Robert J.; Howarth, Robert W.; Mee, Laurence D.; Nixon, Scott W.; Rabalais, Nancy N.; Rosenberg, Rutger; Sanders, James G.; Scavia, Donald; Turner, R. Eugene

    2009-04-01

    During most summers over the past 30 years, bottom dissolved oxygen across a large area of the Louisiana and upper Texas continental shelf declined to concentrations too low (hypoxia) for most fish and large invertebrate animals to survive. This area is one of the best known “dead zones” proliferating around the world [Diaz and Rosenberg, 2008]. During July 2008, hypoxic bottom waters extended across 20,720 square kilometers (Figure 1), but they were probably even more extensive because winds from Hurricane Dolly mixed the waters off Texas before the survey could be completed. Increased inputs of nutrients (principally nitrogen and phosphorus) from the U.S. agricultural heartland within the Mississippi-Atchafalaya River Basin (MARB) are implicated in the development and spread of hypoxia in the Gulf of Mexico. Consequently, the causes of, and solutions for, hypoxia have been subjects of extensive debate and analysis. An integrated scientific assessment led to a 2001 Action Plan [Mississippi River/Gulf of Mexico Watershed Nutrient Task Force, 2001] with a goal of reducing the area of the hypoxic zone to less than 5000 square kilometers by reducing nitrogen loading [Rabalais et al., 2007].

  7. Autophagy, plant senescence, and nutrient recycling.

    PubMed

    Avila-Ospina, Liliana; Moison, Michael; Yoshimoto, Kohki; Masclaux-Daubresse, Céline

    2014-07-01

    Large numbers of publications have appeared over the last few years, dealing with the molecular details of the regulation and process of the autophagy machinery in animals, plants, and unicellular eukaryotic organisms. This strong interest is caused by the fact that the autophagic process is involved in the adaptation of organisms to their environment and to stressful conditions, thereby contributing to cell and organism survival and longevity. In plants, as in other eukaryotes, autophagy is associated with longevity as mutants display early and strong leaf senescence symptoms, however, the exact role of autophagy as a pro-survival or pro-death process is unclear. Recently, evidence that autophagy participates in nitrogen remobilization has been provided, but the duality of the role of autophagy in leaf longevity and/or nutrient recycling through cell component catabolism remains. This review aims to give an overview of leaf senescence-associated processes from the physiological point of view and to discuss relationships between nutrient recycling, proteolysis, and autophagy. The dual role of autophagy as a pro-survival or pro-death process is discussed.

  8. Epidemiology of dietary nutrient intake in ESRD.

    PubMed

    Kovesdy, Csaba P; Shinaberger, Christian S; Kalantar-Zadeh, Kamyar

    2010-01-01

    Protein-energy wasting (PEW) is one of the strongest risk factors of adverse outcomes in patients with chronic kidney disease including those with end-stage renal disease (ESRD) who undergo maintenance dialysis treatment. One important determinant of PEW in this patient population is an inadequate amount of protein and energy intake. Compounding the problem are the many qualitative nutritional deficiencies that arise because of the altered dietary habits of dialysis patients. Many of these alterations are iatrogenically induced, and albeit well intentioned, they could induce unintended harmful effects. In order to determine the best possible diet in ESRD patients, one must first understand the complex interplay between the quantity and quality of nutrient intake in these patients, and their impact on relevant clinical outcomes. We review available studies examining the association of nutritional intake with clinical outcomes in ESRD, stressing the complicated and often difficult-to-study inter-relationship between quantitative and qualitative aspects of nutrient intake in nutritional epidemiology. The currently recommended higher protein intake of 1.2 g/kg/day may be associated with a higher phosphorus and potassium burden and with worsening hyperphosphatemia and hyperkalemia, whereas dietary control of phosphorus and potassium by restricting protein intake may increase the risk of PEW. We assess the relevance of associative studies by examining the biologic plausibility of underlying mechanisms of action and emphasize areas in need of further research.

  9. Lichen substances prevent lichens from nutrient deficiency.

    PubMed

    Hauck, Markus; Willenbruch, Karen; Leuschner, Christoph

    2009-01-01

    The dibenzofuran usnic acid, a widespread cortical secondary metabolite produced by lichen-forming fungi, was shown to promote the intracellular uptake of Cu(2+) in two epiphytic lichens, Evernia mesomorpha and Ramalina menziesii, from acidic, nutrient-poor bark. Higher Cu(2+) uptake in the former, which produces the depside divaricatic acid in addition to usnic acid, suggests that this depside promotes Cu(2+) uptake. Since Cu(2+) is one of the rarest micronutrients, promotion of Cu(2+) uptake by lichen substances may be crucial for the studied lichens to survive in their nutrient-poor habitats. In contrast, study of the uptake of other metals in E. mesomorpha revealed that the intracellular uptake of Mn(2+), which regularly exceeds potentially toxic concentrations in leachates of acidic tree bark, was partially inhibited by the lichen substances produced by this species. Inhibition of Mn(2+) uptake by lichen substances previously has been demonstrated in lichens. The uptake of Fe(2+), Fe(3+), Mg(2+), and Zn(2+), which fail to reach toxic concentrations in acidic bark at unpolluted sites, although they are more common than Cu(2+), was not affected by lichen substances of E. mesomorpha.

  10. Gut microbiota, nutrient sensing and energy balance.

    PubMed

    Duca, F A; Lam, T K T

    2014-09-01

    The gastrointestinal (GI) tract is a highly specialized sensory organ that provides crucial negative feedback during a meal, partly via a gut-brain axis. More specifically, enteroendocrine cells located throughout the GI tract are able to sense and respond to specific nutrients, releasing gut peptides that act in a paracrine, autocrine or endocrine fashion to regulate energy balance, thus controlling both food intake and possibly energy expenditure. Furthermore, the gut microbiota has been shown to provide a substantial metabolic and physiological contribution to the host, and metabolic disease such as obesity has been associated with aberrant gut microbiota and microbiome. Interestingly, recent evidence suggests that the gut microbiota can impact the gut-brain axis controlling energy balance, at both the level of intestinal nutrient-sensing mechanisms, as well as potentially at the sites of integration in the central nervous system. A better understanding of the intricate relationship between the gut microbiota and host energy-regulating pathways is crucial for uncovering the mechanisms responsible for the development of metabolic diseases and for possible therapeutic strategies.

  11. Plant Available Nutrients, Barrow, Alaska, Ver. 1

    DOE Data Explorer

    Sloan, Victoria; Liebig, Jenny; Curtis, Bryan; Hahn, Melanie; Iversen, Colleen; Siegrist, Julie

    2014-02-19

    This dataset consists of measurements of plant available nutrients made using Plant Root Simulator probes (Western Ag Innovations Inc.) during 2012 and 2013. In 2012, Ca, Mg, K, P, Fe, Mn, Cu, Zn, B, S, Pb, Al, Cd, NO3-N and NH4-N were measured during spring, summer and winter in the centers, edges and troughs of four polygons in each of four areas of contrasting moisture regime and polygon type. In 2013, probes were installed in centers, edges and troughs of four polygons in each of two areas (high-centered and low-centered polygons) at two-week intervals and at 3 soil depths to capture fine-scale season dynamics of NO3-N and NH4-N. PRS probes are ion exchange resin membranes held in plastic supports that are inserted into soil to measure ion supply in situ. The anion and cation exchange with the membrane is intended to mimic plant uptake and thus provide a relevant measure of soil nutrient bioavailability. Measurements are made per area of probe membrane and cannot be converted to concentrations or related to soil volume.

  12. Detecting terrestrial nutrient limitation: a global meta-analysis of foliar nutrient concentrations after fertilization

    NASA Astrophysics Data System (ADS)

    Ostertag, Rebecca; DiManno, Nicole

    2016-03-01

    Examining foliar nutrient concentrations after fertilization provides an alternative method for detecting nutrient limitation of ecosystems, which is logistically simpler to measure than biomass change. We present a meta-analysis of response ratios of foliar nitrogen and phosphorus (RRN, RRP) after addition of fertilizer of nitrogen (N), phosphorus (P), or the two elements in combination, in relation to climate, ecosystem type, life form, family, and methodological factors. Results support other meta-analyses using biomass, and demonstrate there is strong evidence for nutrient limitation in natural communities. However, because N fertilization experiments greatly outnumber P fertilization trials, it is difficult to discern the absolute importance of N vs. P vs. co-limitation across ecosystems. Despite these caveats, it is striking that results did not follow "conventional wisdom" that temperate ecosystems are N-limited and tropical ones are P-limited. In addition, the use of ratios of N-to-P rather than response ratios also are a useful index of nutrient limitation, but due to large overlap in values, there are unlikely to be universal cutoff values for delimiting N vs. P limitation. Differences in RRN and RRP were most significant across ecosystem types, plant families, life forms, and between competitive environments, but not across climatic variables.

  13. Nutrient limitation in Northern Gulf of Mexico (NGOM): phytoplankton communities and photosynthesis respond to nutrient pulse.

    PubMed

    Zhao, Yan; Quigg, Antonietta

    2014-01-01

    Although the Mississippi-Atchafalaya River system exports large amounts of nutrients to the Northern Gulf of Mexico annually, nutrient limitation of primary productivity still occurs offshore, acting as one of the major factors controlling local phytoplankton biomass and community structure. Bioassays were conducted for 48 hrs at two stations adjacent to the river plumes in April and August 2012. High Performance of Liquid Chromatography (HPLC) combined with ChemTax and a Fluorescence Induction and Relaxation (FIRe) system were combined to observe changes in the phytoplankton community structure and photosynthetic activity. Major fluorescence parameters (Fo, Fv/Fm) performed well to reveal the stimulating effect of the treatments with nitrogen (N-nitrate) and with nitrogen plus phosphate (+NPi). HPLC/ChemTax results showed that phytoplankton community structure shifted with nitrate addition: we observed an increase in the proportion of diatoms and prasinophytes and a decrease in cyanobacteria and prymnesiophytes. These findings are consistent with predictions from trait-based analysis which predict that phytoplankton groups with high maximum growth rates (μmax ) and high nutrient uptake rates (Vmax ) readily take advantage of the addition of limiting nutrients. Changes in phytoplankton community structure, if persistent, could trigger changes of particular organic matter fluxes and alter the micro-food web cycles and bottom oxygen consumption.

  14. Modelling nutrient emissions and the impact of nutrient reduction measures in the Weser river basin, Germany.

    PubMed

    Hirt, Ulrike; Venohr, Markus; Kreins, Peter; Behrendt, Horst

    2008-01-01

    To implement the European Water Framework Directive (WFD) into German law, measures have to be taken to reduce the unacceptably high nutrient input into rivers. To identify the most effective measures, the sources and pathways of nutrient emissions into rivers have to be quantified. Therefore, the MONERIS model is applied, which quantifies nutrients emissions into river basins, via various point and diffuse pathways, as well as nutrient load in rivers. Most nitrogen emissions come from groundwater flow (43%), tile drainages (30%), and point sources (12%), whereas most phosphorus emissions come from groundwater flow (31%), point sources (23%), erosion (13%) and overland flow (12%). Because of their great distance from the river basin outlet, the southern sub-basins Werra and Fulda-Diemel have an 8% reduction in their nitrogen loads and a 15% and 16% reduction in their phosphorus loads, respectively. This reduction is due to retention in the main part of the river Weser. For the choice of the most effective measures, the different retention in the river is relevant.

  15. Nutrient reduction in field wetlands: do they work for dissolved nutrients?

    NASA Astrophysics Data System (ADS)

    Favaretto, N.; Ockenden, M. C.; Deasy, C.; Quinton, J. N.

    2012-04-01

    Pollution of natural waters arises from both point sources (direct inputs) and diffuse inputs (many small sources entering the waterways by numerous pathways). Legislation has ensured that pollution from point sources has been reduced, thus increasing the significance of diffuse sources, and the contribution from agriculture in particular. Field wetlands (small sediment and nutrient trapping features, < 500 m2), constructed along runoff pathways, are one set of options for diffuse pollution mitigation. Polluted surface runoff as well as subsurface drainage is slowed down by passage through the field wetland, allowing more opportunity for sediment and associated nutrients to settle out. However, the nutrients transported from soil to water are not only attached to the sediment but also in soluble form, and field drains have been identified as a fast pathway for dissolved nutrients to reach the waterways. The soluble form is critical in the short term because it is readily available for aquatic organisms. On the other hand, the particulate form (associated with sediment) is a reservoir for growth and development of aquatic organisms and represents a problem in the long term. The ability of field wetlands to reduce both the particulate and dissolved nutrient loads is being tested in the UK as part of a project on Mitigation Options for Phosphorus and Sediment. Ten field wetlands have been built on farms in the UK, capturing surface runoff and subsurface field drainage, to quantify the sediment and nutrient retention under a range of different conditions. At Whinton Hill in Cumbria (sandy soil), samples from the inlet and outlet of a field wetland system showed an average decrease in the concentration of total solids of 11%. Total phosphorus (TP) was reduced by an average of 43%. However, soluble reactive phosphorus, which accounted for approximately 50% of the TP at the inlet, was reduced by an average of 74%, showing that this wetland made a significant difference to

  16. [Temporal and spatial variation of water nutrient level after exogenous nutrient input].

    PubMed

    Fu, Ling; Zhao, Kai; Wang, Guo-Xiang; Ou, Yuan; Fan, Zhou; Mao, Li-Na; Zhang, Jia; Han, Rui-Ming

    2014-04-01

    In order to study the spatial and temporal variations of nitrogen (N) and phosphorous (P) nutrition in artificial wetlands after a single exogenous nutrient input, 6 mosaic communities of 7 plant species were set up in a cement channel in the greenhouse. After the addition of N and P nutritional solutions, the concentrations of dissolved total nitrogen (DTN), dissolved total phosphorous (DTP), ammonia nitrogen (NH4(+)-N), nitrate nitrogen (NO3(-) -N) and nitrite nitrogen (NO2(-) -N) in the surface, middle, and bottom layers of the bulk water were determined regularly within 22 days. The results show that: (1) the water depth and measuring date have significant effects on nutritional contents while the type of plant communities have no such an influence; (2) the diffusion of nutrient from surface to the middle water layers is relatively slow, which costs 6 days under the current experimental condition; (3) in the bottom water layer, nutritional concentrations had no significant changes except for NO2-N, thus the exogenous nutrient input mainly affects the nutrient contents of surface and middle-level bulk water; (4) DTP and NH4(+) -N contents gradually decline to similar levels that before the nutritional input event until the end of experimental period, though DTN and NO3(-) -N content decrease much more slowly; (5) the fact that NO2(-) -N contents rise in water layers of all depths demonstrates that nitrification and denitrification in the process of N circulation are enhanced. It is concluded that exogenous nutrient inputs not only harm aquatic ecosystems but also directly threat human health.

  17. Nutrient availability and phytoplankton nutrient limitation across a gradient of atmospheric nitrogen deposition

    USGS Publications Warehouse

    Elser, J.J.; Kyle, M.; Steuer, L.; Nydick, K.R.; Baron, J.S.

    2009-01-01

    Atmospheric nitrogen (N) deposition to lakes and watersheds has been increasing steadily due to various anthropogenic activities. Because such anthropogenic N is widely distributed, even lakes relatively removed from direct human disturbance are potentially impacted. However, the effects of increased atmospheric N deposition on lakes are not well documented, We examined phytoplankton biomass, the absolute and relative abundance of limiting nutrients (N and phosphorus [P]), and phytoplankton nutrient limitation in alpine lakes of the Rocky Mountains of Colorado (USA) receiving elevated (>6 kg N??ha-1??yr-1) or low (<2 kg N??ha-1??yr-1) levels of atmospheric N deposition. Highdeposition lakes had higher NO3-N and total N concentrations and higher total N : total P ratios. Concentrations of chlorophyll and seston carbon (C) were 2-2.5 times higher in highdeposition relative to low-deposition lakes, while high-deposition lakes also had higher seston C:N and C:P (but not N:P) ratios. Short-term enrichment bioassays indicated a qualitative shift in the nature of phytoplankton nutrient limitation due to N deposition, as highdeposition lakes had an increased frequency of primary P limitation and a decreased frequency and magnitude of response to N and to combined N and P enrichment. Thus elevated atmospheric N deposition appears to have shifted nutrient supply from a relatively balanced but predominantly N-deficient regime to a more consistently P-limited regime in Colorado alpine lakes. This adds to accumulating evidence that sustained N deposition may have important effects on lake phytoplankton communities and plankton-based food webs by shifting the quantitative and qualitative nature of nutrient limitation. ?? 2009 by the Ecological Society of America.

  18. Hydrologic and biologic influences on stream network nutrient concentrations: Interactions of hydrologic turnover and concentration-dependent nutrient uptake

    NASA Astrophysics Data System (ADS)

    Mallard, John; McGlynn, Brian; Covino, Tim

    2016-04-01

    Stream networks lie in a crucial landscape position between terrestrial ecosystems and downstream water bodies. As such, whether inferring terrestrial watershed processes from watershed outlet nutrient signals or predicting the effect of observed terrestrial processes on stream nutrient signals, it is requisite to understand how stream networks can modulate terrestrial nutrient inputs. To date integrated understanding and modeling of physical and biological influences on nutrient concentrations at the stream network scale have been limited. However, watershed scale groundwater - surface water exchange (hydrologic turnover), concentration-variable biological uptake, and the interaction between the two can strongly modify stream water nutrient concentrations. Stream water and associated nutrients are lost to and replaced from groundwater with distinct nutrient concentrations while in-stream nutrients can also be retained by biological processes at rates that vary with concentration. We developed an empirically based network scale model to simulate the interaction between hydrologic turnover and concentration-dependent nutrient uptake across stream networks. Exchange and uptake parameters were measured using conservative and nutrient tracer addition experiments in the Bull Trout Watershed, central Idaho. We found that the interaction of hydrologic turnover and concentration-dependent uptake combined to modify and subsequently stabilize in-stream concentrations, with specific concentrations dependent on the magnitude of hydrologic turnover, groundwater concentrations, and the shape of nutrient uptake kinetic curves. We additionally found that by varying these physical and biological parameters within measured ranges we were able to generate a spectrum of stream network concentration distributions representing a continuum of shifting magnitudes of physical and biological influences on in-stream concentrations. These findings elucidate the important and variable role of

  19. Agrogeochemical cycles of plant nutrients in the territory of Russia

    NASA Astrophysics Data System (ADS)

    Kudeyarov, V. N.; Semenov, V. M.

    2008-12-01

    The contribution of mineral fertilization to the agrogeochemical cycles of major nutrients (N, P, K) was estimated. The agrogeochemical budgets of major nutrients (NPK) in the territory of Russia are unfavorable for agricultural production for the present and the nearest future. The removal of major nutrients with crops significantly exceeds their input to the soil with fertilizers and other sources. The nutritional degradation of arable soils increases, which can result in irreversible catastrophic consequences within 20-30 years.

  20. Relevance of nutrient media composition for hydrogen production in Chlamydomonas.

    PubMed

    Gonzalez-Ballester, David; Jurado-Oller, Jose Luis; Fernandez, Emilio

    2015-09-01

    Microalgae are capable of biological H2 photoproduction from water, solar energy, and a variety of organic substrates. Acclimation responses to different nutrient regimes finely control photosynthetic activity and can influence H2 production. Hence, nutrient stresses are an interesting scenario to study H2 production in photosynthetic organisms. In this review, we mainly focus on the H2-production mechanisms in Chlamydomonas reinhardtii and the physiological relevance of the nutrient media composition when producing H2.

  1. Posidonia oceanica meadow: a low nutrient high chlorophyll (LNHC) system?

    PubMed Central

    Gobert, Sylvie; Laumont, Noémie; Bouquegneau, Jean-Marie

    2002-01-01

    Background In spite of very low nutrient concentrations in its vicinity – both column and pore waters-, the Posidonia oceanica of the Revellata Bay displays high biomass and productivity. We measured the nutrient fluxes from the sediment into the water enclosed among the leaf shoots ("canopy water") to determine if it is possible source of nutrients for P. oceanica leaves. Results During the summer, the canopy water appears to act as a nutrient reservoir for the plant. During that period, the canopy water layer displays both a temperature 0.5°C cooler than the upper water column, and a much higher nutrient content, as shown in this work using a very simple original technique permitting to sample water with a minimal disturbance of the water column's vertical structure. Despite low nutrient concentrations in pore water, mean net fluxes were measured from the sediment to the canopy water. These fluxes are sufficient to provide 20% of the mean daily nitrogen and phosphorus requirement of the P. oceanica shoots. Conclusion An internal cycling of nutrients from P. oceanica senescent leaves was previously noted as an efficient strategy to help face low nutrient availability. The present study points out a second strategy which consists in holding back, in the canopy, the nutrients released at the water-sediment interface. This process occurs when long leaves, during poor nutrient periods in the water column, providing, to P. oceanica, the possibility to develop, high biomass, high chlorophyll quantities in low nutrient environment (a Low Nutrients High Chlorophyll system). PMID:12188926

  2. Relevance of nutrient media composition for hydrogen production in Chlamydomonas.

    PubMed

    Gonzalez-Ballester, David; Jurado-Oller, Jose Luis; Fernandez, Emilio

    2015-09-01

    Microalgae are capable of biological H2 photoproduction from water, solar energy, and a variety of organic substrates. Acclimation responses to different nutrient regimes finely control photosynthetic activity and can influence H2 production. Hence, nutrient stresses are an interesting scenario to study H2 production in photosynthetic organisms. In this review, we mainly focus on the H2-production mechanisms in Chlamydomonas reinhardtii and the physiological relevance of the nutrient media composition when producing H2. PMID:25952745

  3. Microalgal and cyanobacterial cultivation: the supply of nutrients.

    PubMed

    Markou, Giorgos; Vandamme, Dries; Muylaert, Koenraad

    2014-11-15

    Microalgae and cyanobacteria are a promising new source of biomass that may complement agricultural crops to meet the increasing global demand for food, feed, biofuels and chemical production. Microalgae and cyanobacteria cultivation does not interfere directly with food production, but care should be taken to avoid indirect competition for nutrient (fertilizer) supply. Microalgae and cyanobacteria production requires high concentrations of essential nutrients (C,N,P,S,K,Fe, etc.). In the present paper the application of nutrients and their uptake by microalgae and cyanobacteria is reviewed. The main focus is on the three most significant nutrients, i.e. carbon, nitrogen and phosphorus; however other nutrients are also reviewed. Nutrients are generally taken up in the inorganic form, but several organic forms of them are also assimilable. Some nutrients do not display any inhibition effect on microalgal or cyanobacterial growth, while others, such as NO2 or NH3 have detrimental effects when present in high concentrations. Nutrients in the gaseous form, such as CO2 and NO face a major limitation which is related mainly to their mass transfer from the gaseous to the liquid state. Since the cultivation of microalgae and cyanobacteria consumes considerable quantities of nutrients, strategies to improve the nutrient application efficiency are needed. Additionally, a promising strategy to improve microalgal and cyanobacterial production sustainability is the utilization of waste streams by recycling of waste nutrients. However, major constraints of using waste streams are the reduction of the range of the biomass applications due to production of contaminated biomass and the possible low bio-availability of some nutrients. PMID:25113948

  4. Imaging complex nutrient dynamics in mycelial networks.

    PubMed

    Fricker, M D; Lee, J A; Bebber, D P; Tlalka, M; Hynes, J; Darrah, P R; Watkinson, S C; Boddy, L

    2008-08-01

    Transport networks are vital components of multi-cellular organisms, distributing nutrients and removing waste products. Animal cardiovascular and respiratory systems, and plant vasculature, are branching trees whose architecture is thought to determine universal scaling laws in these organisms. In contrast, the transport systems of many multi-cellular fungi do not fit into this conceptual framework, as they have evolved to explore a patchy environment in search of new resources, rather than ramify through a three-dimensional organism. These fungi grow as a foraging mycelium, formed by the branching and fusion of threadlike hyphae, that gives rise to a complex network. To function efficiently, the mycelial network must both transport nutrients between spatially separated source and sink regions and also maintain its integrity in the face of continuous attack by mycophagous insects or random damage. Here we review the development of novel imaging approaches and software tools that we have used to characterise nutrient transport and network formation in foraging mycelia over a range of spatial scales. On a millimetre scale, we have used a combination of time-lapse confocal imaging and fluorescence recovery after photobleaching to quantify the rate of diffusive transport through the unique vacuole system in individual hyphae. These data then form the basis of a simulation model to predict the impact of such diffusion-based movement on a scale of several millimetres. On a centimetre scale, we have used novel photon-counting scintillation imaging techniques to visualize radiolabel movement in small microcosms. This approach has revealed novel N-transport phenomena, including rapid, preferential N-resource allocation to C-rich sinks, induction of simultaneous bi-directional transport, abrupt switching between different pre-existing transport routes, and a strong pulsatile component to transport in some species. Analysis of the pulsatile transport component using Fourier

  5. Interactive effects of nutrient additions and predation on infaunal communities

    USGS Publications Warehouse

    Posey, M.H.; Alphin, T.D.; Cahoon, L.; Lindquist, D.; Becker, M.E.

    1999-01-01

    Nutrient additions represent an important anthropogenic stress on coastal ecosystems. At moderate levels, increased nutrients may lead to increased primary production and, possibly, to increased biomass of consumers although complex trophic interactions may modify or mask these effects. We examined the influence of nutrient additions and interactive effects of trophic interactions (predation) on benthic infaunal composition and abundances through small-scale field experiments in 2 estuaries that differed in ambient nutrient conditions. A blocked experimental design was used that allowed an assessment of direct nutrient effects in the presence and absence of predation by epibenthic predators as well as an assessment of the independent effects of predation. Benthic microalgal production increased with experimental nutrient additions and was greater when infaunal abundances were lower, but there were no significant interactions between these factors. Increased abundances of one infaunal taxa, Laeonereis culveri, as well as the grazer feeding guild were observed with nutrient additions and a number of taxa exhibited higher abundances with predator exclusion. In contrast to results from freshwater systems there were no significant interactive effects between nutrient additions and predator exclusion as was predicted. The infaunal responses observed here emphasize the importance of both bottom-up (nutrient addition and primary producer driven) and top-down (predation) controls in structuring benthic communities. These processes may work at different spatial and temporal scales, and affect different taxa, making observation of potential interactive effects difficult.

  6. The Interactions of Aquaporins and Mineral Nutrients in Higher Plants.

    PubMed

    Wang, Min; Ding, Lei; Gao, Limin; Li, Yingrui; Shen, Qirong; Guo, Shiwei

    2016-01-01

    Aquaporins, major intrinsic proteins (MIPs) present in the plasma and intracellular membranes, facilitate the transport of small neutral molecules across cell membranes in higher plants. Recently, progress has been made in understanding the mechanisms of aquaporin subcellular localization, transport selectivity, and gating properties. Although the role of aquaporins in maintaining the plant water status has been addressed, the interactions between plant aquaporins and mineral nutrients remain largely unknown. This review highlights the roles of various aquaporin orthologues in mineral nutrient uptake and transport, as well as the regulatory effects of mineral nutrients on aquaporin expression and activity, and an integrated link between aquaporins and mineral nutrient metabolism was identified. PMID:27483251

  7. Diagnosis of nutrient imbalances with vector analysis in agroforestry systems.

    PubMed

    Isaac, Marney E; Kimaro, Anthony A

    2011-01-01

    Agricultural intensification has had unintended environmental consequences, including increased nutrient leaching and surface runoff and other agrarian-derived pollutants. Improved diagnosis of on-farm nutrient dynamics will have the advantage of increasing yields and will diminish financial and environmental costs. To achieve this, a management support system that allows for site-specific rapid evaluation of nutrient production imbalances and subsequent management prescriptions is needed for agroecological design. Vector diagnosis, a bivariate model to depict changes in yield and nutritional response simultaneously in a single graph, facilitates identification of nutritional status such as growth dilution, deficiency, sufficiency, luxury uptake, and toxicity. Quantitative data from cocoa agroforestry systems and pigeonpea intercropping trials in Ghana and Tanzania, respectively, were re-evaluated with vector analysis. Relative to monoculture, biomass increase in cocoa ( L.) under shade (35-80%) was accompanied by a 17 to 25% decline in P concentration, the most limiting nutrient on this site. Similarly, increasing biomass with declining P concentrations was noted for pigeonpea [ (L). Millsp.] in response to soil moisture availability under intercropping. Although vector analysis depicted nutrient responses, the current vector model does not consider non-nutrient resource effects on growth, such as ameliorated light and soil moisture, which were particularly active in these systems. We revisit and develop vector analysis into a framework for diagnosing nutrient and non-nutrient interactions in agroforestry systems. Such a diagnostic technique advances management decision-making by increasing nutrient precision and reducing environmental issues associated with agrarian-derived soil contamination.

  8. The Interactions of Aquaporins and Mineral Nutrients in Higher Plants

    PubMed Central

    Wang, Min; Ding, Lei; Gao, Limin; Li, Yingrui; Shen, Qirong; Guo, Shiwei

    2016-01-01

    Aquaporins, major intrinsic proteins (MIPs) present in the plasma and intracellular membranes, facilitate the transport of small neutral molecules across cell membranes in higher plants. Recently, progress has been made in understanding the mechanisms of aquaporin subcellular localization, transport selectivity, and gating properties. Although the role of aquaporins in maintaining the plant water status has been addressed, the interactions between plant aquaporins and mineral nutrients remain largely unknown. This review highlights the roles of various aquaporin orthologues in mineral nutrient uptake and transport, as well as the regulatory effects of mineral nutrients on aquaporin expression and activity, and an integrated link between aquaporins and mineral nutrient metabolism was identified. PMID:27483251

  9. Improving crop nutrient efficiency through root architecture modifications.

    PubMed

    Li, Xinxin; Zeng, Rensen; Liao, Hong

    2016-03-01

    Improving crop nutrient efficiency becomes an essential consideration for environmentally friendly and sustainable agriculture. Plant growth and development is dependent on 17 essential nutrient elements, among them, nitrogen (N) and phosphorus (P) are the two most important mineral nutrients. Hence it is not surprising that low N and/or low P availability in soils severely constrains crop growth and productivity, and thereby have become high priority targets for improving nutrient efficiency in crops. Root exploration largely determines the ability of plants to acquire mineral nutrients from soils. Therefore, root architecture, the 3-dimensional configuration of the plant's root system in the soil, is of great importance for improving crop nutrient efficiency. Furthermore, the symbiotic associations between host plants and arbuscular mycorrhiza fungi/rhizobial bacteria, are additional important strategies to enhance nutrient acquisition. In this review, we summarize the recent advances in the current understanding of crop species control of root architecture alterations in response to nutrient availability and root/microbe symbioses, through gene or QTL regulation, which results in enhanced nutrient acquisition.

  10. Plant response to nutrient availability across variable bedrock geologies

    USGS Publications Warehouse

    Castle, S.C.; Neff, J.C.

    2009-01-01

    We investigated the role of rock-derived mineral nutrient availability on the nutrient dynamics of overlying forest communities (Populus tremuloides and Picea engelmanni-Abies lasiocarpa v. arizonica) across three parent materials (andesite, limestone, and sandstone) in the southern Rocky Mountains of Colorado. Broad geochemical differences were observed between bedrock materials; however, bulk soil chemistries were remarkably similar between the three different sites. In contrast, soil nutrient pools were considerably different, particularly for P, Ca, and Mg concentrations. Despite variations in nutrient stocks and nutrient availability in soils, we observed relatively inflexible foliar concentrations and foliar stoichiometries for both deciduous and coniferous species. Foliar nutrient resorption (P and K) in the deciduous species followed patterns of nutrient content across substrate types, with higher resorption corresponding to lower bedrock concentrations. Work presented here indicates a complex plant response to available soil nutrients, wherein plant nutrient use compensates for variations in supply gradients and results in the maintenance of a narrow range in foliar stoichiometry. ?? 2008 Springer Science+Business Media, LLC.

  11. The plant ionome revisited by the nutrient balance concept.

    PubMed

    Parent, Serge-Étienne; Parent, Léon Etienne; Egozcue, Juan José; Rozane, Danilo-Eduardo; Hernandes, Amanda; Lapointe, Line; Hébert-Gentile, Valérie; Naess, Kristine; Marchand, Sébastien; Lafond, Jean; Mattos, Dirceu; Barlow, Philip; Natale, William

    2013-01-01

    Tissue analysis is commonly used in ecology and agronomy to portray plant nutrient signatures. Nutrient concentration data, or ionomes, belongs to the compositional data class, i.e., multivariate data that are proportions of some whole, hence carrying important numerical properties. Statistics computed across raw or ordinary log-transformed nutrient data are intrinsically biased, hence possibly leading to wrong inferences. Our objective was to present a sound and robust approach based on a novel nutrient balance concept to classify plant ionomes. We analyzed leaf N, P, K, Ca, and Mg of two wild and six domesticated fruit species from Canada, Brazil, and New Zealand sampled during reproductive stages. Nutrient concentrations were (1) analyzed without transformation, (2) ordinary log-transformed as commonly but incorrectly applied in practice, (3) additive log-ratio (alr) transformed as surrogate to stoichiometric rules, and (4) converted to isometric log-ratios (ilr) arranged as sound nutrient balance variables. Raw concentration and ordinary log transformation both led to biased multivariate analysis due to redundancy between interacting nutrients. The alr- and ilr-transformed data provided unbiased discriminant analyses of plant ionomes, where wild and domesticated species formed distinct groups and the ionomes of species and cultivars were differentiated without numerical bias. The ilr nutrient balance concept is preferable to alr, because the ilr technique projects the most important interactions between nutrients into a convenient Euclidean space. This novel numerical approach allows rectifying historical biases and supervising phenotypic plasticity in plant nutrition studies.

  12. [Nutrient restriction in combinatory therapy of tumors].

    PubMed

    Senichkin, V V; Kopeina, G S; Zamaraev, A V; Lavrik, I N; Zhivotovsky, B D

    2016-01-01

    The main objective of anticancer treatment is the elimination of degenerated cells by the induction of programmed cell death. Various chemotherapy drugs and radiation are able to activate cell death mechanisms in tumors. However, unfortunately, monotherapy will always be insufficiently effective because of the variety and virulence of tumors, as well as their ability to develop resistance to drugs. Moreover, monotherapy might constrain many negative side effects. Therefore, the combination of different approaches and/or drugs will increase the efficiency of treatment. One such promising approach is the combination of nutrient restriction (NR) and various chemotherapeutic drugs. This approach may not only affect the autophagy but also influence apoptotic cell death. This review is focused on the potential of NR use in anticancer therapy, as well as the molecular mechanisms underlying this approach. PMID:27414780

  13. Nutrient-contaminant (Pu) plant accumulation model

    SciTech Connect

    Cowan, C.E.; Jenne, E.A.; Simpson, J.C.; Cataldo, D.A.

    1981-12-01

    A model was developed which simulates the movement and daily accumulation of nutrients and contaminants in crop plants resulting from known physiological processes in the plant. In the model, the daily contaminant accumulation is governed by daily increase in plant biomass derived from photosynthesis and by the specified thermodynamic activity of the bioavailable contaminant species in soil or hydroponic solutin. Total accumulation and resulting concentration in the plant's root, stem and branch, leaf, and reproductive compartments can be simulated any time during the growing season. Parameters were estimated from data on plutonium accumulation in soybeans and the model was calibrated against this same data set. The plutonium distribution in the plant was found to be most sensitive to parameters related to leaf accumulation. Contamination at different times during the growing season resulted in a large change in predicted leaf accumulation but very little change in predicted accumulation in other plant parts except when contamination occurred very late in the growing season.

  14. Nutrient controls on biocomplexity of mangrove ecosystems

    USGS Publications Warehouse

    McKee, Karen L.

    2004-01-01

    Mangrove forests are important coastal ecosystems that provide a variety of ecological and societal services. These intertidal, tree-dominated communities along tropical coastlines are often described as “simple systems,” compared to other tropical forests with larger numbers of plant species and multiple understory strata; however, mangrove ecosystems have complex trophic structures, and organisms exhibit unique physiological, morphological, and behavioral adaptations to environmental conditions characteristic of the land-sea interface. Biogeochemical functioning of mangrove forests is also controlled by interactions among the microbial, plant, and animal communities and feedback linkages mediated by hydrology and other forcing functions. Scientists with the U.S. Geological Survey (USGS) at the National Wetlands Research Center are working to understand more fully the impact of nutrient variability on these delicate and important ecosystems.

  15. Therapeutic perspectives of epigenetically active nutrients

    PubMed Central

    Remely, M; Lovrecic, L; de la Garza, A L; Migliore, L; Peterlin, B; Milagro, F I; Martinez, A J; Haslberger, A G

    2015-01-01

    Many nutrients are known for a wide range of activities in prevention and alleviation of various diseases. Recently, their potential role in regulating human health through effects on epigenetics has become evident, although specific mechanisms are still unclear. Thus, nutriepigenetics/nutriepigenomics has emerged as a new and promising field in current epigenetics research in the past few years. In particular, polyphenols, as part of the central dynamic interaction between the genome and the environment with specificity at physiological concentrations, are well known to affect mechanisms underlying human health. This review summarizes the effects of dietary compounds on epigenetic mechanisms in the regulation of gene expression including expression of enzymes and other molecules responsible for drug absorption, distribution, metabolism and excretion in cancer, metabolic syndrome, neurodegenerative disorders and hormonal dysfunction. PMID:25046997

  16. Nutrient pathways of flexor tendons in primates

    SciTech Connect

    Manske, P.R.; Lesker, P.A.

    1982-09-01

    The perfusion and diffusion pathways to the flexor profundus tendons of 40 monkeys were investigated by measuring the uptake of tritiated proline by various tendon segments. In the absence of all vascular connections, the process of diffusion provides nutrients to all areas of flexor tendon and in this study the process of diffusion was greater. The distal segment of tendon was observed to be profused most rapidly. The proximal tendon segment is perfused from both the muscular-tendinous junction and the vinculum longus; vincular segment perfusion is via the vinculum longus vessels alone; central segment perfusion is shared by the vinculum longus and vinculum brevis vasculature. The distal segment uptake is by both the process of diffusion or vinculum brevis perfusion. The osseous attachment at the distal phalanx contributes little to tendon nutrition.

  17. Nutrient Uptake Kinetics in Two Virginia Estuaries

    NASA Astrophysics Data System (ADS)

    Henry, A.; Mulholland, M. R.; Bernhardt, P.; Watson, A. M.; Dias, R. F.

    2002-12-01

    Recently, there has been an increase in the occurrence and geographical range of blooms of the brown tide pelagophyte Aureococcus anophagefferens in coastal areas along the east coast of the USA. Brown tide blooms occur when concentrations of inorganic nutrients are low or at the limit of analytical detection and these organisms have been shown to use organic nitrogen for growth. Indeed, it has been suggested that A. anophagefferens, along with a variety of other species that form harmful algal blooms, have a preference for organic nitrogen and because organic nitrogen compounds also have carbon, it is thought that many bloom species may supplement photosynthetic carbon fixation with uptake of organic carbon. In order to better understand the nutritional preferences of bloom organisms, we investigated uptake kinetics for inorganic and organic nutrients in two Virginia waterways where harmful algal blooms frequently occur; the Rappahannock River, a Chesapeake Bay tributary that experiences blooms of dinoflagellates, and Chincoteague Bay, a coastal bay where there are seasonal brown tide blooms. We used stable isotopes (15N and 13C) to measure uptake kinetics for NH4+, urea, two amino acids, a dipeptide and glucose. During the Chincoteague Bay study, there was a bloom of A. anophagefferens (> 1,000,000 cells/ml), however, no blooms were encountered during the Rappahannock Study. Results suggest that brown tide bloom populations had higher affinities and uptake capacities for NH4+ and dipeptides and lower affinities and uptake capacities for urea and the two amino acids. In addition, it appeared that the organic substrates were used primarily as N sources.

  18. Nutrient Intake in Heart Failure Patients

    PubMed Central

    Grossniklaus, Daurice A.; O’Brien, Marian C.; Clark, Patricia C.; Dunbar, Sandra B.

    2009-01-01

    Background and Research Objective Approximately 50% of heart failure (HF) patients are thought to be malnourished, and macronutrient and micronutrient deficiencies may potentially aggravate HF symptoms. Thus, concerns have been raised about the overall nutrient composition of diets in HF populations. The purpose of this study was to examine the macronutrient and micronutrient intake by caloric adequacy among community-dwelling adults with HF. Participants and Methods A secondary analysis of baseline data of participants in an HF lifestyle intervention study was conducted. Participants (n = 45) were predominantly male (55.6%), white, and non-Hispanic (64.4%); had a mean age of 61 years (SD, 11 years) and mean body mass index of 31.2 kg/m2 (SD, 7.3 kg/m2); were of New York Heart Association functional classes II and III (77.8%); and had a mean ejection fraction of 31.9% (SD,13.2%); and 69% had a college or higher level of education. The Block Food Habits Questionnaire was used to assess the intake of macronutrients and micronutrients. Analysis included descriptive statistics and Mann-Whitney U tests. Results and Conclusions Individuals reporting inadequate daily caloric intake reported a lower intake of macronutrients and micronutrients as well as other differences in dietary patterns compared with individuals reporting adequate daily caloric intake. More than half of the individuals reporting adequate caloric intake did not meet the recommended dietary allowance for magnesium and vitamin E. Interventions aimed at increasing overall intake and nutrient density are suggested. Further research is needed to better understand the relationship between dietary factors and outcomes in HF. PMID:18596500

  19. Lateral Diffusion of Nutrients by Mammalian Herbivores in Terrestrial Ecosystems

    PubMed Central

    Wolf, Adam; Doughty, Christopher E.; Malhi, Yadvinder

    2013-01-01

    Animals translocate nutrients by consuming nutrients at one point and excreting them or dying at another location. Such lateral fluxes may be an important mechanism of nutrient supply in many ecosystems, but lack quantification and a systematic theoretical framework for their evaluation. This paper presents a mathematical framework for quantifying such fluxes in the context of mammalian herbivores. We develop an expression for lateral diffusion of a nutrient, where the diffusivity is a biologically determined parameter depending on the characteristics of mammals occupying the domain, including size-dependent phenomena such as day range, metabolic demand, food passage time, and population size. Three findings stand out: (a) Scaling law-derived estimates of diffusion parameters are comparable to estimates calculated from estimates of each coefficient gathered from primary literature. (b) The diffusion term due to transport of nutrients in dung is orders of magnitude large than the coefficient representing nutrients in bodymass. (c) The scaling coefficients show that large herbivores make a disproportionate contribution to lateral nutrient transfer. We apply the diffusion equation to a case study of Kruger National Park to estimate the conditions under which mammal-driven nutrient transport is comparable in magnitude to other (abiotic) nutrient fluxes (inputs and losses). Finally, a global analysis of mammalian herbivore transport is presented, using a comprehensive database of contemporary animal distributions. We show that continents vary greatly in terms of the importance of animal-driven nutrient fluxes, and also that perturbations to nutrient cycles are potentially quite large if threatened large herbivores are driven to extinction. PMID:23951141

  20. Porous tube plant nutrient delivery system development: A device for nutrient delivery in microgravity

    NASA Technical Reports Server (NTRS)

    Dreschel, T. W.; Brown, C. S.; Piastuch, W. C.; Hinkle, C. R.; Knott, W. M.

    1994-01-01

    The Porous Tube Plant Nutrient Delivery Systems or PTPNDS (U.S. Patent #4,926,585) has been under development for the past six years with the goal of providing a means for culturing plants in microgravity, specifically providing water and nutrients to the roots. Direct applications of the PTPNDS include plant space biology investigations on the Space Shuttle and plant research for life support in the Space Station Freedom. In the past, we investigated various configurations, the suitability of different porous materials, and the effects of pressure and pore size on plant growth. Current work is focused on characterizing the physical operation of the system, examining the effects of solution aeration, and developing prototype configurations for the Plant Growth Unit (PGU), the flight system for the Shuttle mid-deck. Future developments will involve testing on KC-135 parabolic flights, the design of flight hardware and testing aboard the Space Shuttle.

  1. The Coupling of Solution Chemistry to Plant Nutrient Demand in an on Demand Nutrient Delivery System

    NASA Technical Reports Server (NTRS)

    Savage, Wayne

    1998-01-01

    The goal of the proposal will be to determine the suitability of the DASI instrument in providing a signal that can be recognized and be utilized as an indicator of plant stress. The method to be utilized for evaluating stress is the presentation of an every increasing level of nutrient deficiency and salinity stress (addition of salt (NACl) or increasing concentration of balanced nutrient) while simultaneously recording spectral reflectance using the DASI instrument and monitoring the traditional processes of gas exchange and nutrient uptake parameters. In this manner, we will be able to directly compare the DASI measurements with known stresses as determined by the traditional gas exchange and nutrient uptake measures of stress. We anticipate that the DASI will provide a sensitive identifier of plant stress; recording signals of the resulting changes in plant metabolism in real time, far before any visible effects of stress could be observed. Thus, there is a potential for very early management intervention to correct a stress condition before damage could develop. The present response time for the observation of visual symptoms of plant stress is considerable and only provides an indication that a stress is present after it has been present for an extended period of time. Thus, the impact of a plant-based life support function will have already been significant. An additional benefit of this research to regenerative life support will be the characterization of a potential recovery scenario from various degrees of stress. The experimental approach to be employed includes the removal of the stress at various points in the stress gradient and the characterization of plant performance and reflectance spectra during recovery from various degrees of stress. Spectral reflectance imaging techniques have been developed and used to measure the biochemical composition of plants and relate these characteristics to the fluxes of biochemical elements within the ecosystem.

  2. Excess nutrients in hydroponic solutions alter nutrient content of rice, wheat, and potato.

    PubMed

    McKeehen, J D; Mitchell, C A; Wheeler, R M; Bugbee, B; Nielsen, S S

    1996-01-01

    Environment has significant effects on the nutrient content of field-grown crop plants. Little is known, however, about compositional changes caused by controlled environments in which plants receive only artificial radiation and soilless, hydroponic culture. This knowledge is essential for developing a safe, nutritious diet in a Controlled Ecological Life-Support System (CELSS). Three crops that are candidates for inclusion in a CELSS (rice, wheat, and white potato) were grown both in the field and in controlled environments where the hydroponic nutrient solution, photosynthetic photon flux (PPF), and CO2 level were manipulated to achieve rapid growth rates. Plants were harvested at maturity, separated into discrete parts, and dried prior to analysis. Plant materials were analyzed for proximate composition (protein, fat, ash, and carbohydrate), total nitrogen (N), nitrate, minerals, and amino-acid composition. The effect of environment on nutrient content varied by crop and plant part. Total N and nonprotein N (NPN) contents of plant biomass generally increased under controlled-environment conditions compared to field conditions, especially for leafy plant parts and roots. Nitrate levels were increased in hydroponically-grown vegetative tissues, but nitrate was excluded from grains and tubers. Mineral content changes in plant tissue included increased phosphorus and decreased levels of certain micronutrient elements under controlled-environment conditions. These findings suggest that cultivar selection, genetic manipulation, and environmental control could be important to obtain highly nutritious biomass in a CELSS.

  3. Plant nutrients do not covary with soil nutrients under changing climatic conditions

    NASA Astrophysics Data System (ADS)

    Luo, Wentao; Elser, James J.; Lü, Xiao-Tao; Wang, Zhengwen; Bai, Edith; Yan, Caifeng; Wang, Chao; Li, Mai-He; Zimmermann, Niklaus E.; Han, Xingguo; Xu, Zhuwen; Li, Hui; Wu, Yunna; Jiang, Yong

    2015-08-01

    Nitrogen (N) and phosphorus (P) play vital roles in plant growth and development. Yet how climate regimes and soil fertility influence plant N and P stoichiometry is not well understood, especially in the belowground plant parts. Here we investigated plant aboveground and belowground N and P concentrations ([N] and [P]) and their stoichiometry in three dominant genera along a 2200 km long climatic gradient in northern China. Results showed that temperature explained more variation of [N] and [P] in C4 plants, whereas precipitation exerted a stronger influence on [N] and [P] in C3 plants. Both plant aboveground and belowground [N] and [P] increased with decreasing precipitation, and increasing temperatures yet were negatively correlated with soil [N] and [P]. Plant N:P ratios were unrelated with all climate and soil variables. Plant aboveground and belowground [N] followed an allometric scaling relationship, but the allocation of [P] was isometric. These results imply that internal processes stabilize plant N:P ratios and hence tissue N:P ratios may not be an effective parameter for predicting plant nutrient limitation. Our results also imply that past positive relationships between plant and nutrient stocks may be challenged under changing climatic conditions. While any modeling would need to be able to replicate currently observed relationships, it is conceivable that some relationships, such as those between temperature or rainfall and carbon:nutrient ratios, should be different under changing climatic conditions.

  4. Excess nutrients in hydroponic solutions alter nutrient content of rice, wheat, and potato

    NASA Astrophysics Data System (ADS)

    McKeehen, J. D.; Mitchell, C. A.; Wheeler, R. M.; Bugbee, B.; Nielsen, S. S.

    Environment has significant effects on the nutrient content of field-grown crop plants. Little is known, however, about compositional changes caused by controlled environments in which plants receive only artificial radiation and soilless, hydroponic culture. This knowledge is essential for developing a safe, nutritious diet in a Controlled Ecological Life-Support System (CELSS). Three crops that are candidates for inclusion in a CELSS (rice, wheat, and white potato) were grown both in the field and in controlled environments where the hydroponic nutrient solution, photosynthetic photon flux (PPF), and CO_2 level were manipulated to achieve rapid growth rates. Plants were harvested at maturity, separated into discrete parts, and dried prior to analysis. Plant materials were analyzed for proximate composition (protein, fat, ash, and carbohydrate), total nitrogen (N), nitrate, minerals, and amino-acid composition. The effect of environment on nutrient content varied by crop and plant part. Total N and nonprotein N (NPN) contents of plant biomass generally increased under controlled-environment conditions compared to field conditions, especially for leafy plant parts and roots. Nitrate levels were increased in hydroponically-grown vegetative tissues, but nitrate was excluded from grains and tubers. Mineral content changes in plant tissue included increased phosphorus and decreased levels of certain micronutrient elements under controlled-environment conditions. These findings suggest that cultivar selection, genetic manipulation, and environmental control could be important to obtain highly nutritious biomass in a CELSS.

  5. Excess nutrients in hydroponic solutions alter nutrient content of rice, wheat, and potato

    NASA Technical Reports Server (NTRS)

    McKeehen, J. D.; Mitchell, C. A.; Wheeler, R. M.; Bugbee, B.; Nielsen, S. S.

    1996-01-01

    Environment has significant effects on the nutrient content of field-grown crop plants. Little is known, however, about compositional changes caused by controlled environments in which plants receive only artificial radiation and soilless, hydroponic culture. This knowledge is essential for developing a safe, nutritious diet in a Controlled Ecological Life-Support System (CELSS). Three crops that are candidates for inclusion in a CELSS (rice, wheat, and white potato) were grown both in the field and in controlled environments where the hydroponic nutrient solution, photosynthetic photon flux (PPF), and CO2 level were manipulated to achieve rapid growth rates. Plants were harvested at maturity, separated into discrete parts, and dried prior to analysis. Plant materials were analyzed for proximate composition (protein, fat, ash, and carbohydrate), total nitrogen (N), nitrate, minerals, and amino-acid composition. The effect of environment on nutrient content varied by crop and plant part. Total N and nonprotein N (NPN) contents of plant biomass generally increased under controlled-environment conditions compared to field conditions, especially for leafy plant parts and roots. Nitrate levels were increased in hydroponically-grown vegetative tissues, but nitrate was excluded from grains and tubers. Mineral content changes in plant tissue included increased phosphorus and decreased levels of certain micronutrient elements under controlled-environment conditions. These findings suggest that cultivar selection, genetic manipulation, and environmental control could be important to obtain highly nutritious biomass in a CELSS.

  6. Reference Condition Approach for Numeric Nutrient Criteria for Oregon Estuaries

    EPA Science Inventory

    Development of nutrient criteria for all water body types of the US remains a top priority for EPA. Estuaries in the Pacific Northwest receive nutrients from both the watershed and the coastal ocean, and thus are particularly complex systems in which to establish water quality c...

  7. USDA Nutrient Data Set for Retail Veal Cuts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The U.S. Department of Agriculture (USDA) Nutrient Data Laboratory (NDL), in collaboration with Colorado State University, conducted a research study designed to update and expand the data on veal cuts in the USDA National Nutrient Database for Standard Reference (SR). This research has been necess...

  8. Association of arsenic with nutrient elements in rice plants.

    PubMed

    Duan, Guilan; Liu, Wenju; Chen, Xueping; Hu, Ying; Zhu, Yongguan

    2013-06-01

    Rice is the main cereal crop that feeds half of the world's population, and two thirds of the Chinese population. Arsenic (As) contamination in paddy soil and irrigation water elevates As concentration in rice grains, thus rice consumption is an important As intake route for populations in south and south-east Asia, where rice is the staple food. In addition to direct toxicity of As to human, As may limit the accumulation of micro-nutrients in rice grains, such as selenium (Se) and zinc (Zn). These micro-nutrients are essential for humans, while mineral deficiencies, especially iron (Fe) and Zn, are prevalent in China. Therefore, it is important to understand the interactions between As and micro-nutrients in rice plants, which is the principal source of these nutrients for people on rice diets. In addition, during the processes of As uptake, translocation and transformation, the status of macro-nutrients (e.g. silicon (Si), phosphors (P), sulfur (S)) are important factors affecting As dynamics in soil-plant systems and As accumulation in rice grains. Recently, synchrotron-based spectroscopic techniques have been applied to map the distribution of As and nutrient elements in rice plants, which will aid to understand how As are accumulated, complexed and transported within plants. This paper reviews the interactions between As and macro-nutrients, as well as micro-nutrients in rice plants. PMID:23771154

  9. Nutrient uptake of peanut genotypes under different water regimes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drought is a serious environmental stress limiting growth and productivity in peanut and other crops. Nutrient uptake of peanut is reduced under drought conditions, which reduces yield. The objectives of this study were to investigate nutrient uptake of peanut genotypes in response to drought and ...

  10. Association of arsenic with nutrient elements in rice plants.

    PubMed

    Duan, Guilan; Liu, Wenju; Chen, Xueping; Hu, Ying; Zhu, Yongguan

    2013-06-01

    Rice is the main cereal crop that feeds half of the world's population, and two thirds of the Chinese population. Arsenic (As) contamination in paddy soil and irrigation water elevates As concentration in rice grains, thus rice consumption is an important As intake route for populations in south and south-east Asia, where rice is the staple food. In addition to direct toxicity of As to human, As may limit the accumulation of micro-nutrients in rice grains, such as selenium (Se) and zinc (Zn). These micro-nutrients are essential for humans, while mineral deficiencies, especially iron (Fe) and Zn, are prevalent in China. Therefore, it is important to understand the interactions between As and micro-nutrients in rice plants, which is the principal source of these nutrients for people on rice diets. In addition, during the processes of As uptake, translocation and transformation, the status of macro-nutrients (e.g. silicon (Si), phosphors (P), sulfur (S)) are important factors affecting As dynamics in soil-plant systems and As accumulation in rice grains. Recently, synchrotron-based spectroscopic techniques have been applied to map the distribution of As and nutrient elements in rice plants, which will aid to understand how As are accumulated, complexed and transported within plants. This paper reviews the interactions between As and macro-nutrients, as well as micro-nutrients in rice plants.

  11. Effect of acute heat stress on plant nutrient metabolism proteins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abrupt heating decreased the levels (per unit total root protein) of all but one of the nutrient metabolism proteins examined, and for most of the proteins, effects were greater for severe vs. moderate heat stress. For many of the nutrient metabolism proteins, initial effects of heat (1 d) were r...

  12. Insights into Digestion and Absorption of Major Nutrients in Humans

    ERIC Educational Resources Information Center

    Goodman, Barbara E.

    2010-01-01

    Nutrient digestion and absorption is necessary for the survival of living organisms and has evolved into the complex and specific task of the gastrointestinal (GI) system. While most people simply assume that their GI tract will work properly to use nutrients, provide energy, and release wastes, few nonscientists know the details about how various…

  13. Nutrient attenuation in rivers and streams, Puget Sound Basin, Washington

    USGS Publications Warehouse

    Sheibley, Rich W.; Konrad, Christopher P.; Black, Robert W.

    2015-01-01

    From a management perspective, preservation and improvement of instream nutrient attenuation should focus on increasing the travel time through a reach and contact time of water sediment (reactive) surfaces and lowering nutrient concentrations (and loads) to avoid saturation of instream attenuation and increase attenuation efficiency. These g

  14. Approaches for Development of Nutrient Criteria in Oregon Estuaries

    EPA Science Inventory

    Development of nutrient criteria for all water body types of the US remains a top priority for EPA. Estuaries in the Pacific Northwest receive nutrients from both the watershed and the coastal ocean, and thus are particularly complex systems in which to establish water quality c...

  15. 9 CFR 381.413 - Nutrient content claims; general principles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... formulas and medical foods, as described in 21 CFR 101.13(q)(4). (5) (6) Nutrient content claims that were... sodium” or “contains 100 calories.” (2) An implied nutrient content claim is any claim that: (i... false or misleading in any respect (e.g., “100 calories” or “5 grams of fat”), in which case...

  16. Nutrient Exchange through Hyphae in Intercropping Systems Affects Yields

    ERIC Educational Resources Information Center

    Thun, Tim Von

    2013-01-01

    Arbuscular mycorrhizae fungi (AMF) play a large role in the current understanding of the soil ecosystem. They increase nutrient and water uptake, improve soil structure, and form complex hyphal networks that transfer nutrients between plants within an ecosystem. Factors such as species present, the physiological balance between the plants in the…

  17. Narrow grass hedge effects on nutrient transport following compost application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of stiff-stemmed grass hedges can be a valuable soil conservation measure. A study was conducted to measure the effectiveness of a narrow grass hedge, planted on the contour along the hillslope, in reducing runoff nutrient transport from plots with a range of soil nutrient values. Composted ...

  18. Effects of acid rain on forest nutrient status

    SciTech Connect

    Johnson, D.W.; Turner, J.; Kelly, J.M.

    1982-06-01

    The paper presents an extensive literature review that deals with the assessment of the effects of acidic atmospheric inputs on forest nutrient status within the context of natural, internal acid production by carbonic and organic acids as well as the nutrient inputs and drains by management practices such as harvesting, fire and fertilization. 123 refs.

  19. Nutrient availability at Mer Bleue bog measured by PRSTM probes

    NASA Astrophysics Data System (ADS)

    Wang, M.; Moore, T. R.; Talbot, J.

    2015-12-01

    Bogs, covering ~0.7 million km2 in Canada, store a large amount of C and N. As nutrient deficient ecosystems, it's critical to examine the nutrient availabilities and seasonal dynamics. We used Plant Root Simulators (PRSTM) at Mer Bleue bog to provide some baseline data on nutrient availability and its variability. In particular, we focused on ammonium, nitrate, phosphate, calcium, magnesium and potassium, iron, sulphate and aluminum. We placed PRS probes at a depth of 5 - 15 cm in pristine plots and plots with long term N, P and K fertilization for 4 weeks and determined the availability of these nutrients, from spring through to fall. Probes were also placed beneath the water table in hummock and hollow microtopography and along a transect including part of the bog which had been drained through the creation of a ditch 80 years ago. The result showed that there was limited available ammonium, nitrate and phosphate in the bog, the seasonal variation of nutrient availabilities probably due to mineralization, an increase in the availability of some nutrients between different water table depths or as a result of drainage, and the relative availability of nutrients compared to the input from fertilization. We suggest that PRS probes could be a useful tool to examine nutrient availability and dynamics in wetlands, with careful consideration of installing condition, for example, proper exposure period, depth relative to water table etc.

  20. Landscape influence on soil carbon and nutrient levels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Past runoff, erosion, and management practices influence nutrient levels on the landscape. These starting levels affect future nutrient transport due to runoff, erosion, and leaching events. The purpose of this study was to examine closed-depression landscape effects on surface soil organic matter, ...

  1. BENTHIC NUTRIENT FLUX IN A SMALL ESTUARY IN NORTHWESTERNFLORIDA (USA)

    EPA Science Inventory

    Benthic Nutrient Flux in a Small Estuary in Northwestern Florida(USA).Gulf and Caribbean Research 18, 15-25, 2006.

    Benthic nutrient fluxes of ammonium (NH4+), nitrite/nitrate (NO2-+NO3-), phosphate (PO4-), and dissolved silica (DSi) were measured in Escambia Bay, an estuar...

  2. Biotechnology of nutrient uptake and assimilation in plants.

    PubMed

    López-Arredondo, Damar L; Leyva-González, Marco A; Alatorre-Cobos, Fulgencio; Herrera-Estrella, Luis

    2013-01-01

    Plants require a complex balance of mineral nutrients to reproduce successfully. Because the availability of many of these nutrients in the soil is compromised by several factors, such as soil pH, cation presence, and microbial activity, crop plants depend directly on nutrients applied as fertilizers to achieve high yields. However, the excessive use of fertilizers is a major environmental concern due to nutrient leaching that causes water eutrophication and promotes toxic algae blooms. This situation generates the urgent need for crop plants with increased nutrient use efficiency and better-designed fertilization schemes. The plant biology revolution triggered by the development of efficient gene transfer systems for plant cells together with the more recent development of next-generation DNA and RNA sequencing and other omics platforms have advanced considerably our understanding on the molecular basis of plant nutrition and how plants respond to nutritional stress. To date, genes encoding sensors, transcription factors, transporters, and metabolic enzymes have been identified as potential candidates to improve nutrient use efficiency. In addition, the study of other genetic resources, such as bacteria and fungi, allows the identification of alternative mechanisms of nutrient assimilation, which are potentially applicable in plants. Although significant progress in this respect has been achieved by conventional breeding, in this review we focus on the biotechnological approaches reported to date aimed at boosting the use of the three most limiting nutrients in the majority of arable lands: nitrogen, phosphorus, and iron.

  3. USDA updates nutrient values for fast food pizza

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. Nutrient and Pesticide Removal From Laboratory Simulated Tile Drainage Discharge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Excess nutrient and pesticide transport through subsurface tile drainage is well documented. One approach receiving consideration for reducing the amount of nutrients and pesticides in subsurface drainage waters is end-of-tile filters. The filters are often comprised of industrial wastes or by-produ...

  5. Mariculture: significant and expanding cause of coastal nutrient enrichment

    NASA Astrophysics Data System (ADS)

    Bouwman, Lex; Beusen, Arthur; Glibert, Patricia M.; Overbeek, Ciska; Pawlowski, Marcin; Herrera, Jorge; Mulsow, Sandor; Yu, Rencheng; Zhou, Mingjiang

    2013-12-01

    Mariculture (marine aquaculture) generates nutrient waste either through the excretion by the reared organisms, or through direct enrichment by, or remineralization of, externally applied feed inputs. Importantly, the waste from fish or shellfish cannot easily be managed, as most is in dissolved form and released directly to the aquatic environment. The release of dissolved and particulate nutrients by intensive mariculture results in increasing nutrient loads (finfish and crustaceans), and changes in nutrient stoichiometry (all mariculture types). Based on different scenarios, we project that nutrients from mariculture will increase up to six fold by 2050 with exceedance of the nutrient assimilative capacity in parts of the world where mariculture growth is already rapid. Increasing nutrient loads and altered nutrient forms (increased availability of reduced relative to oxidized forms of nitrogen) and/or stoichiometric proportions (altered nitrogen:phosphorus ratios) may promote an increase in harmful algal blooms (HABs) either directly or via stimulation of algae on which mixotrophic HABs may feed. HABs can kill or intoxicate the mariculture product with severe economic losses, and can increase risks to human health.

  6. Biotechnology of nutrient uptake and assimilation in plants.

    PubMed

    López-Arredondo, Damar L; Leyva-González, Marco A; Alatorre-Cobos, Fulgencio; Herrera-Estrella, Luis

    2013-01-01

    Plants require a complex balance of mineral nutrients to reproduce successfully. Because the availability of many of these nutrients in the soil is compromised by several factors, such as soil pH, cation presence, and microbial activity, crop plants depend directly on nutrients applied as fertilizers to achieve high yields. However, the excessive use of fertilizers is a major environmental concern due to nutrient leaching that causes water eutrophication and promotes toxic algae blooms. This situation generates the urgent need for crop plants with increased nutrient use efficiency and better-designed fertilization schemes. The plant biology revolution triggered by the development of efficient gene transfer systems for plant cells together with the more recent development of next-generation DNA and RNA sequencing and other omics platforms have advanced considerably our understanding on the molecular basis of plant nutrition and how plants respond to nutritional stress. To date, genes encoding sensors, transcription factors, transporters, and metabolic enzymes have been identified as potential candidates to improve nutrient use efficiency. In addition, the study of other genetic resources, such as bacteria and fungi, allows the identification of alternative mechanisms of nutrient assimilation, which are potentially applicable in plants. Although significant progress in this respect has been achieved by conventional breeding, in this review we focus on the biotechnological approaches reported to date aimed at boosting the use of the three most limiting nutrients in the majority of arable lands: nitrogen, phosphorus, and iron. PMID:24166442

  7. Linkages between nutrients and assemblages of macroinvertebrates and fish in wadeable streams: Implication to nutrient criteria development

    USGS Publications Warehouse

    Wang, L.; Robertson, D.M.; Garrison, P.J.

    2007-01-01

    We sampled 240 wadeable streams across Wisconsin for different forms of phosphorus and nitrogen, and assemblages of macroinvertebrates and fish to (1) examine how macroinvertebrate and fish measures correlated with the nutrients; (2) quantify relationships between key biological measures and nutrient forms to identify potential threshold levels of nutrients to support nutrient criteria development; and (3) evaluate the importance of nutrients in influencing biological assemblages relative to other physicochemical factors at different spatial scales. Twenty-three of the 35 fish and 18 of the 26 macroinvertebrate measures significantly correlated (P < 0.05) with at least one nutrient measure. Percentages of carnivorous, intolerant, and omnivorous fishes, index of biotic integrity, and salmonid abundance were fish measures correlated with the most nutrient measures and had the highest correlation coefficients. Percentages of Ephemeroptera-Plecoptera-Trichoptera individuals and taxa, Hilsenhoff biotic index, and mean tolerance value were macroinvertebrate measures that most strongly correlated with the most nutrient measures. Selected biological measures showed clear trends toward degradation as concentrations of phosphorus and nitrogen increased, and some measures showed clear thresholds where biological measures changed drastically with small changes in nutrient concentrations. Our selected environmental factors explained 54% of the variation in the fish assemblages. Of this explained variance, 46% was attributed to catchment and instream habitat, 15% to nutrients, 3% to other water quality measures, and 36% to the interactions among all the environmental variables. Selected environmental factors explained 53% of the variation in macroinvertebrate assemblages. Of this explained variance, 42% was attributed to catchment and instream habitat, 22% to nutrients, 5% to other water quality measures, and 32% to the interactions among all the environmental variables. ?? 2006

  8. Nutrient vectors and riparian nutrient processing in African semiarid savanna ecosystems

    USGS Publications Warehouse

    Jacobs, Shayne M.; Bechtold, J.S.; Biggs, Harry C.; Grimm, N. B.; McClain, M.E.; Naiman, R.J.; Perakis, Steven S.; Pinay, G.; Scholes, M.C.

    2007-01-01

    This review article describes vectors for nitrogen and phosphorus delivery to riparian zones in semiarid African savannas, the processing of nutrients in the riparian zone and the effect of disturbance on these processes. Semiarid savannas exhibit sharp seasonality, complex hillslope hydrology and high spatial heterogeneity, all of which ultimately impact nutrient fluxes between riparian, upland and aquatic environments. Our review shows that strong environmental drivers such as fire and herbivory enhance nitrogen, phosphorus and sediment transport to lower slope positions by shaping vegetative patterns. These vectors differ significantly from other arid and semiarid ecosystems, and from mesic ecosystems where the impact of fire and herbivory are less pronounced and less predictable. Also unique is the presence of sodic soils in certain hillslopes, which substantially alters hydrological flowpaths and may act as a trap where nitrogen is immobilized while sediment and phosphorus transport is enhanced. Nutrients and sediments are also deposited in the riparian zone during seasonal, intermittent floods while, during the dry season, subsurface movement of water from the stream into riparian soils and vegetation further enrich riparian zones with nutrients. As is found in mesic ecosystems, nutrients are immobilized in semiarid riparian corridors through microbial and plant uptake, whereas dissimilatory processes such as denitrification may be important where labile nitrogen and carbon are in adequate supply and physical conditions are suitablea??such as in seeps, wallows created by animals, ephemeral wetlands and stream edges. Interaction between temporal hydrologic connectivity and spatial heterogeneity are disrupted by disturbances such as large floods and extended droughts, which may convert certain riparian patches from sinks to sources for nitrogen and phosphorus. In the face of increasing anthropogenic pressure, the scientific challenges are to provide a basic

  9. Optimal foraging for specific nutrients in predatory beetles

    PubMed Central

    Jensen, Kim; Mayntz, David; Toft, Søren; Clissold, Fiona J.; Hunt, John; Raubenheimer, David; Simpson, Stephen J.

    2012-01-01

    Evolutionary theory predicts that animals should forage to maximize their fitness, which in predators is traditionally assumed equivalent to maximizing energy intake rather than balancing the intake of specific nutrients. We restricted female predatory ground beetles (Anchomenus dorsalis) to one of a range of diets varying in lipid and protein content, and showed that total egg production peaked at a target intake of both nutrients. Other beetles given a choice to feed from two diets differing only in protein and lipid composition selectively ingested nutrient combinations at this target intake. When restricted to nutritionally imbalanced diets, beetles balanced the over- and under-ingestion of lipid and protein around a nutrient composition that maximized egg production under those constrained circumstances. Selective foraging for specific nutrients in this predator thus maximizes its reproductive performance. Our findings have implications for predator foraging behaviour and in the structuring of ecological communities. PMID:22237910

  10. [NUTRIENTS AND RADIOTHERAPY; REVIEW OF THE LITERATURE].

    PubMed

    Luna, Javier; Amaya, Enrique; de Torres, M Victoria; Peña, M Carmen; Prieto, Isabel

    2015-12-01

    Introducción: la nutrición ejerce una importante influencia sobre los tratamientos y la calidad de vida del paciente oncológico. En la actualidad, la relación de los distintos componentes nutricionales con el tratamiento radioterápico es un tema de creciente interés. Objetivos: evaluar la posible influencia de los macro y micronutrientes sobre la tolerancia y eficacia del tratamiento radioterápico, así como su papel en la modulación de la toxicidad crónica. Material y métodos: se ha realizado una revisión bibliográfica consultando las bases de datos MEDLINE y Biblioteca Cochrane online entre los años 2000 y 2015, seleccionando los trabajos más relevantes según factor de impacto. Los datos obtenidos de los estudios analizados se han expuesto por apartados según el tipo de nutriente. Resultados: la mayoría de los estudios analizados presentan características comunes: pequeños tamaños muestrales, alta heterogeneidad en estudios de un mismo tema, escaso poder estadístico, pocos estudios prospectivos y aleatorizados. En el apartado de la fibra, su empleo como profilaxis y tratamiento de la enteritis rádica ha sido evaluado con resultados satisfactorios en algunos estudios, aunque la evidencia de su recomendación es todavía débil. Los ácidos grasos omega‑3 y omega‑6 tienen una gran potencialidad metabólica, aunque la evidencia de su beneficio se limita a estudios observacionales en determinados tumores. Entre los aminoácidos, la glutamina es el más estudiado, con resultados contradictorios en el aporte de beneficio en la mucositis oral, la esofagitis y la enteritis rádica. Las vitaminas y minerales constituyen un grupo heterogéneo de sustancias con beneficio potencial por su actividad antioxidante y su posible efecto protector, disminuyendo la toxicidad producida por la radioterapia. Las dietas cetogénicas están comenzando a estudiarse clínicamente después de los prometedores resultados preclínicos. Conclusiones: los estudios

  11. Annual cycle and budgets of nutrients in the Bohai sea

    NASA Astrophysics Data System (ADS)

    Liang, Zhao; Hao, Wei; Shizuo, Feng

    2002-04-01

    The environmental problems in the Bohai Sea have become more serious in the last decade. High nutrient concentration contributes much to it. A Sino-German cooperation program has been carried out to improve the understanding of the ecosystem by observations and modelling. A three-dimensional ecosystem model, coupled with a physical transport model, is adopted in this study. The simulation for the year 1982 is validated by the data collected in 1982/1983. The simulated annual mean nutrient concentrations are in good agreement with observations. The nutrient concentrations in the bohai Sea, which are crucial to the algal growth, are high in winter and low in summer. There are depletion from spring to summer and elevation from autumn to winter for nutrients. The nutrients’ depletion is a response to the consumption of the phytoplankton bloom in spring. Internal recycle and external compensation affect the nutrient cycle. Their contributions to the nutrient budgets are discussed based on the simulated results. Production and respiration are the most important sink and source of nutrients. The process of photosynthesis consumes 152 kilotons-P and 831.1 kilotons-N while respiration releases 94.5 kilotons-P and 516.6 kilotons-N in the same period. The remineralization of the detritus pool is an important source of nutrient regeneration, It can compensate 23 percent of the nutrient consumed by the production process. The inputs of phosphates and nitrogen from rivers are 0.55 and 52.7 kilotons respectively. The net nutrient budget is -3.05 kilotons-P and 31.6 kilotons-N.

  12. The nutrient density approach to healthy eating: challenges and opportunities.

    PubMed

    Nicklas, Theresa A; Drewnowski, Adam; O'Neil, Carol E

    2014-12-01

    The term 'nutrient density' for foods/beverages has been used loosely to promote the Dietary Guidelines for Americans. The 2010 Dietary Guidelines for Americans defined 'all vegetables, fruits, whole grains, fat-free or low-fat milk and milk products, seafood, lean meats and poultry, eggs, beans and peas (legumes), and nuts and seeds that are prepared without added solid fats, added sugars, and sodium' as nutrient dense. The 2010 Dietary Guidelines for Americans further states that nutrient-dense foods and beverages provide vitamins, minerals and other substances that may have positive health effects with relatively few (kilo)calories or kilojoules. Finally, the definition states nutrients and other beneficial substances have not been 'diluted' by the addition of energy from added solid fats, added sugars or by the solid fats naturally present in the food. However, the Dietary Guidelines Advisory Committee and other scientists have failed to clearly define 'nutrient density' or to provide criteria or indices that specify cut-offs for foods that are nutrient dense. Today, 'nutrient density' is a ubiquitous term used in the scientific literature, policy documents, marketing strategies and consumer messaging. However, the term remains ambiguous without a definitive or universal definition. Classifying or ranking foods according to their nutritional content is known as nutrient profiling. The goal of the present commentary is to address the research gaps that still exist before there can be a consensus on how best to define nutrient density, highlight the situation in the USA and relate this to wider, international efforts in nutrient profiling.

  13. Farmers' use of nutrient management: lessons from watershed case studies.

    PubMed

    Osmond, Deanna L; Hoag, Dana L K; Luloff, Al E; Meals, Donald W; Neas, Kathy

    2015-03-01

    Nutrient enrichment of water resources has degraded coastal waters throughout the world, including in the United States (e.g., Chesapeake Bay, Gulf of Mexico, and Neuse Estuary). Agricultural nonpoint sources have significant impacts on water resources. As a result, nutrient management planning is the primary tool recommended to reduce nutrient losses from agricultural fields. Its effectiveness requires nutrient management plans be used by farmers. There is little literature describing nutrient management decision-making. Here, two case studies are described that address this gap: (i) a synthesis of the National Institute of Food and Agriculture, the Conservation Effects Assessment Project, and (ii) field surveys from three nutrient-impaired river basins/watersheds in North Carolina (Neuse, Tar-Pamlico, and Jordan Lake drainage areas). Results indicate farmers generally did not fully apply nutrient management plans or follow basic soil test recommendations even when they had them. Farmers were found to be hesitant to apply N at university-recommended rates because they did not trust the recommendations, viewed abundant N as insurance, or used recommendations made by fertilizer dealers. Exceptions were noted when watershed education, technical support, and funding resources focused on nutrient management that included easing management demands, actively and consistently working directly with a small group of farmers, and providing significant resource allocations to fund agency personnel and cost-share funds to farmers. Without better dialogue with farmers and meaningful investment in strategies that reward farmers for taking what they perceive as risks relative to nutrient reduction, little progress in true adoption of nutrient management will be made. PMID:26023957

  14. Effect of soil in nutrient cycle assessment at dairy farms

    NASA Astrophysics Data System (ADS)

    van Leeuwen, Maricke; de Boer, Imke; van Dam, Jos; van Middelaar, Corina; Stoof, Cathelijne

    2016-04-01

    Annual farm nutrient cycle assessments give valuable insight in the nutrient cycles and nutrient losses at dairy farms. It describes nutrient use efficiencies for the entire farm and for the underlying components cattle, manure, crops and soil. In many modelling studies, soil is kept as a constant factor, while soil quality is vital for soil functioning of the ecosystem. Improving soil quality will improve the nutrient cycle, and will also have positive effect on the soil functions crop production, water cycling and greenhouse gas mitigation. Spatial variation of soil properties within a farm, however, are not included in annual nutrient cycle assessments. Therefore it is impossible to identify fields where most profit can be gained by improving farm management at field level, and it is not possible to identify and to quantify nutrient flow path ways. The aim of this study is to develop a framework to improve the annual nutrient cycle assessment at Dutch dairy farms, by including soil properties and their spatial variation within farms. Soil type and soil quality will be described by visual soil assessment of soil quality characteristics. The visual observations will be linked to the nutrient cycle assessment, using soil-hydrological model SWAP. We will demonstrate how soil quality at field level can impact on crop production, eutrophication potential and greenhouse gas potential at farm level. Also, we will show how this framework can be used by farmers to improve their farm management. This new approach is focusing on annual nutrient cycle assessment, but could also be used in life cycle assessment. It will improve understanding of soil functioning and dairy farm management.

  15. Nutrient resorption helps drive intra-specific coupling of foliar nitrogen and phosphorus under nutrient-enriched conditions

    USGS Publications Warehouse

    Xiao-Tao, Lü; Reed, Sasha C.; Yu, Qiang; Han, Xing-Guo

    2016-01-01

    Taken together, the results suggest plants in this ecosystem are much more responsive to changing N cycles than P cycles and emphasize the significance of nutrient resorption as an important plant control over the stoichiometric coupling of N and P under nutrient enriched conditions.

  16. Reference Materials for Determination of the Nutrient Composition of Foods: Results from USDA's National Food and Nutrient Analysis Program

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Certified reference materials (CRMs) play a critical role in validating the accuracy of nutrient data for food samples. A number of available food CRMs of differing matrix composition have assigned concentrations for various nutrients, along with associated uncertainty intervals (UIs) for those valu...

  17. Effects of soil applications of micro-nutrients and chelating agent citric acid on mineral nutrients in soybean seeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Micro-nutrients deficiency in soil result in crop yield loss and poor seed quality. Correcting this deficiency is normally conducted by foliar or soil application. The objective of this research was to determine the effects of soil applications of five micro-nutrients (Mn, Cu, Zn, Mo, and B) with a ...

  18. Nutrient cycling in a tropical seasonal rain forest of Xishuangbanna, Southwest China. Part 1: tree species: nutrient distribution and uptake.

    PubMed

    Shanmughavel, P; Sha, L; Zheng, Z; Cao, M

    2001-12-01

    Tropical rain forests are characterized by large numbers of the species with diverse growth habits. The objective of the present study was to determine the distribution of nutrient content in the major trees of the tropical rain forests in Xishuangbanna. This will improve the understanding of the nutrient losses from such sites that result from harvesting and flow of nutrients within the ecosystem and lead to the development of effective and rational forest management strategies. Based on the results in this study, the distribution of nutrients among biomass components of trees varied: The ordering of major elements concentrations was K > N > Mg > Ca > P in branch, stem and root tissues but was N > K > Mg > Ca > P in leaves. The maximum amount of all nutrients per ha occurred in the stems followed by branches, roots and leaves. Of the total uptake of 6167.7 kg ha(-1) of all nutrients, the contribution of various nutrients was found to be N (2010.6 t ha(-1)), P (196.3 t ha(-1)), K (2123.8 kg ha(-1)), Ca (832 kg ha(-1)) and Mg (1005 kg ha(-1)). However, comparing the nutrient uptake of other tropical and sub tropical forests, the results indicated that rates for the Xishuangbanna forests were 20-35% lower than previously reported values.

  19. Evaluation of nutrient variability in highly consumed "fast foods" under the National Food and Nutrient Analysis Program

    Technology Transfer Automated Retrieval System (TEKTRAN)

    USDA's National Food and Nutrient Analysis Program generates means and standard errors (S.E.) of nutrients in foods from nationally representative sample sets used in dietary assessment and consumer education. However, genetic makeup, growing/shipping/storage conditions, preparation techniques, and ...

  20. REGIONAL DATABASE FOR WATERSHED CLASSIFICATION, NUTRIENT-RESPONSE RELATIONSHIPS, AND DIAGNOSTIC INDICATORS IN SUPPORT OF NUTRIENT CRITERIA DEVELOPMENT

    EPA Science Inventory

    USEPA has published recommended nutrient criteria for streams as a starting point for protecting surface water resources and is encouraging states/tribes to refine the proposed nutrient criteria, with help from EPA's Regional offices. . . In cooperation with EPA's Office of Envir...

  1. Comparison of Nutrient Content and Cost of Home-Packed Lunches to Reimbursable School Lunch Nutrient Standards and Prices

    ERIC Educational Resources Information Center

    Johnson, Cara M.; Bednar, Carolyn; Kwon, Junehee; Gustof, Alissa

    2009-01-01

    Purpose: The purpose of this study was to compare nutrient content and cost of home-packed lunches to nutrient standards and prices for reimbursable school lunches. Methods: Researchers observed food and beverage contents of 333 home packed lunches at four north Texas elementary schools. Nutritionist Pro was used to analyze lunches for calories,…

  2. Thinning affects nutrient resorption and nutrient-use efficiency in two Pinus sylvestris stands in the Pyrenees.

    PubMed

    Blanco, Juan A; Imbert, J Bosco; Castillo, Federico J

    2009-04-01

    Needle chemical composition was measured, and nutrient resorption, nutrient-use efficiency (NUE), and other indexes were estimated for 24 months in two contrasting natural Pinus sylvestris L. forests in the western Pyrenees in Spain. For each location (Aspurz, 650 m elevation, 7% slope; Garde, 1335 m elevation, 40% slope), there were three reference plots (P0), three plots with 20% of the basal area removed (P20), and three with 30% of the basal area removed (P30). Needle P, Ca, and Mg concentrations were higher in Garde, but N concentration was higher for Aspurz, without differences for K. Nutrient-resorption efficiency of P was higher in Aspurz, of Mg higher in Garde, and there were no differences between sites in N and K. Nutrient-resorption proficiency was significantly higher in the site with lower soil nutrient availability, i.e., for P, Ca, and Mg in Aspurz, but N in Garde (no differences in K); this may be an indicator of nutrient conservation strategy. Annual nutrient productivity (A) was higher for all nutrients in Aspurz, whereas the mean residence time (MRT) was higher in Garde in all nutrients but P. NUE was significantly higher in Garde for all nutrients but P, which was more efficiently used in Aspurz. In both sites, N, P, and K concentrations were higher in the 2002 cohort, Ca in the 2000 cohort, and maximum Mg was found in the 2001 cohort. Thinning caused a reduction of Mg concentration in the 2001 cohort in Aspurz, an increase of Ca resorption proficiency in Aspurz and Mg resorption at both sites, and reduction of P, K, and Mg nutrient response efficiency (NRE) in Garde. Thinning may have caused an increase of the C:Mg ratio through facilitating the development of more biosynthesis apparatus in a more illuminated canopy, but it seemed not to affect resorption in a significant way. Changes in NRE in Garde after thinning show that forest management can affect how trees use nutrients. Our results indicate that the strategy to optimize NUE is

  3. Closing Domestic Nutrient Cycles Using Microalgae.

    PubMed

    Vasconcelos Fernandes, Tânia; Shrestha, Rabin; Sui, Yixing; Papini, Gustavo; Zeeman, Grietje; Vet, Louise E M; Wijffels, Rene H; Lamers, Packo

    2015-10-20

    This study demonstrates that microalgae can effectively recover all P and N from anaerobically treated black water (toilet wastewater). Thus, enabling the removal of nutrients from the black water and the generation of a valuable algae product in one step. Screening experiments with green microalgae and cyanobacteria showed that all tested green microalgae species successfully grew on anaerobically treated black water. In a subsequent controlled experiment in flat-panel photobioreactors, Chlorella sorokiniana was able to remove 100% of the phosphorus and nitrogen from the medium. Phosphorus was depleted within 4 days while nitrogen took 12 days to reach depletion. The phosphorus and nitrogen removal rates during the initial linear growth phase were 17 and 122 mg·L(-1)·d(-1), respectively. After this initial phase, the phosphorus was depleted. The nitrogen removal rate continued to decrease in the second phase, resulting in an overall removal rate of 80 mg·L(-1)·d(-1). The biomass concentration at the end of the experiment was 11.5 g·L(-1), with a P content of approximately 1% and a N content of 7.6%. This high algal biomass concentration, together with a relatively short P recovery time, is a promising finding for future post-treatment of black water while gaining valuable algal biomass for further application. PMID:26389714

  4. Nutrient support of the healing wound.

    PubMed

    Meyer, N A; Muller, M J; Herndon, D N

    1994-05-01

    Wound healing is a series of complex physicochemical interactions that require various micronutrients at every step. In the critically ill or severely injured patient, wound healing is impaired by the protein-catabolic, hypermetabolic response to stress. The hypothalamus responds to cytokine stimulation by increasing the thermoregulatory set-point and by augmenting elaboration of stress hormones (catecholamines, cortisol, and glucagon). In turn, the stress hormones induce thermogenic futile substrate cycling, lipolysis, and proteolysis. Increased glucose production results at the expense of skeletal muscle degradation, producing amino acid substrate for hepatic gluconeogenesis. Nutritional support of the hypermetabolic state is an essential part of ensuring efficient wound healing in these patients. Protein catabolism cannot be reversed by increased amino acid availability alone, due partly to a defect in amino acid transport. This defect can be reversed by anabolic agents, such as growth hormone and insulin-like growth factor-1. Growth hormone treatment dramatically improves wound healing in severely burned children. Supplementation with protein and vitamins, specifically arginine and vitamins A, B, and C, provides optimum nutrient support of the healing wound. PMID:7922445

  5. Uncertainty propagation in an ecosystem nutrient budget.

    PubMed

    Lehrter, John C; Cebrian, Just

    2010-03-01

    New aspects and advancements in classical uncertainty propagation methods were used to develop a nutrient budget with associated uncertainty for a northern Gulf of Mexico coastal embayment. Uncertainty was calculated for budget terms by propagating the standard error and degrees of freedom. New aspects include the combined use of Monte Carlo simulations with classical error propagation methods, uncertainty analyses for GIS computations, and uncertainty propagation involving literature and subjective estimates of terms used in the budget calculations. The methods employed are broadly applicable to the mathematical operations employed in ecological studies involving step-by-step calculations, scaling procedures, and calculations of variables from direct measurements and/or literature estimates. Propagation of the standard error and the degrees of freedom allowed for calculation of the uncertainty intervals around every term in the budget. For scientists and environmental managers, the methods developed herein provide a relatively simple framework to propagate and assess the contributions of uncertainty in directly measured and literature estimated variables to calculated variables. Application of these methods to environmental data used in scientific reporting and environmental management will improve the interpretation of data and simplify the estimation of risk associated with decisions based on ecological studies.

  6. Nutrient reserve dynamics of breeding canvasbacks

    USGS Publications Warehouse

    Barzen, J.A.; Serie, J.R.

    1990-01-01

    We compared nutrients in reproductive and nonreproductive tissues of breeding Canvasbacks (Aythya valisineria) to assess the relative importance of endogenous reserves and exogenous foods. Fat reserves of females increased during rapid follicle growth and varied more widely in size during the early phase of this period. Females began laying with ca. 205 g of fat in reserve and lost 1.8 g of carcass fat for every 1 g of fat contained in their ovary and eggs. Females lost body mass (primarily fat) at a declining rate as incubation advanced. Protein reserves increased directly with dry oviduct mass during rapid follicle growth. This direct relationship was highly dependent upon data from 2 birds and likely biased by structural size. During laying, protein reserves did not vary with the combined mass of dry oviduct and dry egg protein. Between laying and incubation, mean protein reserves decreased by an amount equal to the protein found in 2.1 Canvasback eggs. Calcium reserves did not vary with the cumulative total of calcium deposited in eggs. Mean calcium reserve declined by the equivalent content of 1.2 eggs between laying and incubation. We believe that protein and calcium were stored in small amounts during laying, and that they were supplemented continually by exogenous sources. In contrast, fat was stored in large amounts and contributed significantly to egg production and body maintenance. Male Canvasbacks lost fat steadily--but not protein or calcium--as the breeding season progressed.

  7. Nutrient dyshomeostasis in congestive heart failure.

    PubMed

    Kamalov, German; Holewinski, Joshua P; Bhattacharya, Syamal K; Ahokas, Robert A; Sun, Yao; Gerling, Ivan C; Weber, Karl T

    2009-07-01

    The clinical syndrome congestive heart failure (CHF) has its origins rooted in a salt-avid state mediated largely by effector hormones of the renin-angiotensin-aldosterone system. In recent years, this cardiorenal perspective of CHF has taken on a broader perspective. One which focuses on a progressive systemic illness, whose major features include the presence of oxidative stress in diverse tissues and elevated circulating levels of proinflammatory cytokines coupled with a wasting of soft tissues and bone. Experimental studies, which simulate chronic renin-angiotensin-aldosterone system activation, and translational studies in patients with salt avidity having decompensated biventricular failure with hepatic and splanchnic congestion have forged a broader understanding of this illness and the important contribution of a dyshomeostasis of Ca2+, Mg2+, Zn2+, Se2+, and vitamins D, B12, and B1. Herein, we review biomarkers indicative of the nutrient imbalance found in CHF and raise the question of a need for a polynutrient supplement in the overall management of CHF. PMID:19593100

  8. Neural regulation of intestinal nutrient absorption.

    PubMed

    Mourad, Fadi H; Saadé, Nayef E

    2011-10-01

    The nervous system and the gastrointestinal (GI) tract share several common features including reciprocal interconnections and several neurotransmitters and peptides known as gut peptides, neuropeptides or hormones. The processes of digestion, secretion of digestive enzymes and then absorption are regulated by the neuro-endocrine system. Luminal glucose enhances its own absorption through a neuronal reflex that involves capsaicin sensitive primary afferent (CSPA) fibres. Absorbed glucose stimulates insulin release that activates hepatoenteric neural pathways leading to an increase in the expression of glucose transporters. Adrenergic innervation increases glucose absorption through α1 and β receptors and decreases absorption through activation of α2 receptors. The vagus nerve plays an important role in the regulation of diurnal variation in transporter expression and in anticipation to food intake. Vagal CSPAs exert tonic inhibitory effects on amino acid absorption. It also plays an important role in the mediation of the inhibitory effect of intestinal amino acids on their own absorption at the level of proximal or distal segment. However, chronic extrinsic denervation leads to a decrease in intestinal amino acid absorption. Conversely, adrenergic agonists as well as activation of CSPA fibres enhance peptides uptake through the peptide transporter PEPT1. Finally, intestinal innervation plays a minimal role in the absorption of fat digestion products. Intestinal absorption of nutrients is a basic vital mechanism that depends essentially on the function of intestinal mucosa. However, intrinsic and extrinsic neural mechanisms that rely on several redundant loops are involved in immediate and long-term control of the outcome of intestinal function.

  9. [Prevention of Alzheimer's Disease and Nutrients].

    PubMed

    Otsuka, Mieko

    2016-07-01

    The dietary recommendations for the prevention and management of Alzheimer's disease (AD), are the Mediterranean diet and the Japanese-style diet, both of which contain well-balanced nutrients from fish and vegetables. These diets are rich in vitamin E, carotenes, antioxidant flavonoids, vitamin B12, folate, and n-3PUFA. According to recent review supplementation of folate and vitamin E may protect against elderly people's cognitive decline when the serum folate is <12 nmol/L or the vitamin E intake is <6.1 mg/day. Another nutritional topic with regard to dementia and diet is the association of type-2 diabetes and hyperinsulinemia with AD. Expression array data of the brain tissue of AD patients in the Hisayama study strongly suggests a disturbance in insulin signaling in the AD brain. The dysfunction of insulin signaling could directly lead to disrupted glucose utilization in the AD brain. Instead of improperly utilized glucose, the medium chain triglyceride ketone bodies can be an alternative energy resource for the AD brain. In conclusion, the dietary recommendations for the prevention and management of AD are a high consumption of fish, vegetables, and low glycemic index fruits; a moderate amount of meat and dairy products; and a lower amount of carbohydrates and refined sugar. PMID:27395465

  10. Alcohol effects on drug-nutrient interactions.

    PubMed

    Seitz, H K

    1985-01-01

    The interaction of ethanol with drugs and xenobiotics is complex because ethanol can affect any of the following steps; absorption, plasma protein binding, hepatic blood flow, distribution, hepatic uptake of drugs, and phase I and II hepatic metabolism. The ingestion of ethanol can lead to malabsorption of a variety of nutrients and can modify the absorption of various drugs. High concentrations of ethanol in conjunction with aspirin causes gastric mucosal damage. The principal effect of acute ethanol ingestion on drug metabolism is inhibition of microsomal drug metabolism. The synergistic effects of ethanol on central nervous system depressants can be explained by this mechanism. In contrast, chronic ethanol consumption increases mixed function oxidation and drug metabolism. The cross tolerance between ethanol and sedatives in chronic alcoholics may be due to this effect of alcohol. In addition, enhanced production of hepatotoxic products from certain drugs and xenobiotics and an increased activation of procarcinogens to carcinogens can result from this microsomal induction. The increased susceptibility to hepatotoxins and the enhanced carcinogenesis in the alcoholic may be explained by this fact. Other effects of the interaction between drugs and ethanol are the result of changes in organ susceptibility, best demonstrated for the central nervous system. Subsequently, the presence of liver disease has a great effect on drug metabolism in alcoholics.

  11. Nutrient support of the healing wound.

    PubMed

    Meyer, N A; Muller, M J; Herndon, D N

    1994-05-01

    Wound healing is a series of complex physicochemical interactions that require various micronutrients at every step. In the critically ill or severely injured patient, wound healing is impaired by the protein-catabolic, hypermetabolic response to stress. The hypothalamus responds to cytokine stimulation by increasing the thermoregulatory set-point and by augmenting elaboration of stress hormones (catecholamines, cortisol, and glucagon). In turn, the stress hormones induce thermogenic futile substrate cycling, lipolysis, and proteolysis. Increased glucose production results at the expense of skeletal muscle degradation, producing amino acid substrate for hepatic gluconeogenesis. Nutritional support of the hypermetabolic state is an essential part of ensuring efficient wound healing in these patients. Protein catabolism cannot be reversed by increased amino acid availability alone, due partly to a defect in amino acid transport. This defect can be reversed by anabolic agents, such as growth hormone and insulin-like growth factor-1. Growth hormone treatment dramatically improves wound healing in severely burned children. Supplementation with protein and vitamins, specifically arginine and vitamins A, B, and C, provides optimum nutrient support of the healing wound.

  12. Nutrient management effects on sweetpotato genotypes under controlled environment

    NASA Technical Reports Server (NTRS)

    David, P. P.; Bonsi, C. K.; Trotman, A. A.; Douglas, D. Z.

    1996-01-01

    Sweetpotato is one of several crops recommended by National Aeronautics and Space Administration (NASA) for bioregenerative life support studies. One of the objectives of the Tuskegee University NASA Center is to optimize growth conditions for adaptability of sweetpotatoes for closed bioregenerative systems. The role of nutrient solution management as it impacts yield has been one of the major thrusts in these studies. Nutrient solution management protocol currently used consists of a modified half Hoagland solution that is changed at 14-day intervals. Reservoirs are refilled with deionized water if the volume of the nutrient solution was reduced to 8 liters or less before the time of solution change. There is the need to recycle and replenish nutrient solution during crop growth, rather than discard at 14 day intervals as previously done, in order to reduce waste. Experiments were conducted in an environmental growth room to examine the effects of container size on the growth of several sweetpotato genotypes grown under a nutrient replenishment protocol. Plants were grown from vine cuttings of 15cm length and were planted in 0.15 x 0.15 x 1.2m growth channels using a closed nutrient film technique system. Nutrient was supplied in a modified half strength Hoagland's solution with a 1:2.4 N:K ratio. Nutrient replenishment protocol consisted of daily water replenishment to a constant volume of 30.4 liters in the small containers and 273.6 liters in the large container. Nutrients were replenished as needed when the EC of the nutrient solution fell below 1200 mhos/cm. The experimental design used was a split-plot with the main plot being container size and genotypes as the subplot. Nine sweetpotato genotypes were evaluated. Results showed no effect of nutrient solution container size on storage root yield, foliage fresh and dry mass, leaf area or vine length. However, plants grown using the large nutrient solution container accumulated more storage root dry mass than

  13. Turbulence effects on the ratio of particulate carbon production to nutrient assimilation across nutrient gradients: An experimental approach.

    NASA Astrophysics Data System (ADS)

    Vidal, M.; Alcaraz, M.; Egge, J.; Jacobsen, A.; Marrasé, C.; Peters, F.; Roldán, C.; Thingstad, T. F.

    2003-04-01

    The uptake of inorganic carbon by the marine biota has been extensively studied in the context of the biological carbon pump. Carbon incorporation into biomass has been related to the availability of light and essential nutrients, such as dissolved inorganic nitrogen and phosphorus. Usually, it has been considered that nutrients are assimilated concurrently to inorganic carbon at constant Redfield proportions. Nevertheless, recent measurements have shown that, in some oceanic regions, the amount of inorganic carbon removed from the water significantly exceeded the amount expected from the removal of dissolved inorganic nutrients. This finding suggested that carbon incorporated into biomass per unit of consumed nitrogen or phosphorus might vary with time and across systems. The possible generalisation of this variability should have important consequences on the exportation of carbon and the role of the microbial plankton community on global carbon fluxes. Nutrient availability and light conditions have been invoked as the main factors influencing the ratio of particulate carbon production to nutrient assimilation. Despite the recognition of turbulence as a key factor influencing microbial dynamics, there is a lack of studies specifically relating the effect of turbulence on that ratio. Turbulence has been recently shown to increase the living carbon produced per phosphate consumed in microcosm experiments done with Mediterranean nutrient-starved plankton communities. According to this, we hypothesise that this effect may be found in other plankton communities and vary across gradients of nutrient concentration. We enclosed natural plankton communities from both Norwegian and Mediterranean coastal waters and subjected them to varying turbulence conditions and nutrient loads to monitor particulate and dissolved carbon and nutrient dynamics. We found that the effect of turbulence increased as nutrient concentration decreased. The magnitude of the response differed

  14. Henrique da Rocha Lima*

    PubMed Central

    Bernardes Filho, Fred; Avelleira, João Carlos Regazzi

    2015-01-01

    Brazilian physician and researcher Henrique da Rocha Lima was born in 1879 in the city of Rio de Janeiro, where he studied medicine and obtained the degree of M.D. in 1901. He specialized in Clinical Medicine in Germany and was the ambassador in European countries of the scientific medicine that emerged from the Oswaldo Cruz Institute in the early twentieth century. Rocha Lima has discovered the causative agent of typhus and had a major contribution to the studies of yellow fever, Chagas disease, Carrión’s disease and histoplasmosis. His genius, his research and his discoveries projected his name, and, with it, the image of Brazil in the international scientific scene. PMID:26131867

  15. Stoichiometric patterns in foliar nutrient resorption across multiple scales

    USGS Publications Warehouse

    Reed, Sasha C.; Townsend, Alan R.; Davidson, Eric A.; Cleveland, Cory C.

    2012-01-01

    *Nutrient resorption is a fundamental process through which plants withdraw nutrients from leaves before abscission. Nutrient resorption patterns have the potential to reflect gradients in plant nutrient limitation and to affect a suite of terrestrial ecosystem functions. *Here, we used a stoichiometric approach to assess patterns in foliar resorption at a variety of scales, specifically exploring how N : P resorption ratios relate to presumed variation in N and/or P limitation and possible relationships between N : P resorption ratios and soil nutrient availability. *N : P resorption ratios varied significantly at the global scale, increasing with latitude and decreasing with mean annual temperature and precipitation. In general, tropical sites (absolute latitudes < 23°26′) had N : P resorption ratios of < 1, and plants growing on highly weathered tropical soils maintained the lowest N : P resorption ratios. Resorption ratios also varied with forest age along an Amazonian forest regeneration chronosequence and among species in a diverse Costa Rican rain forest. *These results suggest that variations in N : P resorption stoichiometry offer insight into nutrient cycling and limitation at a variety of spatial scales, complementing other metrics of plant nutrient biogeochemistry. The extent to which the stoichiometric flexibility of resorption will help regulate terrestrial responses to global change merits further investigation.

  16. Cooperative nutrient accumulation sustains growth of mammalian cells.

    PubMed

    Son, Sungmin; Stevens, Mark M; Chao, Hui Xiao; Thoreen, Carson; Hosios, Aaron M; Schweitzer, Lawrence D; Weng, Yaochung; Wood, Kris; Sabatini, David; Vander Heiden, Matthew G; Manalis, Scott

    2015-01-01

    The coordination of metabolic processes to allow increased nutrient uptake and utilization for macromolecular synthesis is central for cell growth. Although studies of bulk cell populations have revealed important metabolic and signaling requirements that impact cell growth on long time scales, whether the same regulation influences short-term cell growth remains an open question. Here we investigate cell growth by monitoring mass accumulation of mammalian cells while rapidly depleting particular nutrients. Within minutes following the depletion of glucose or glutamine, we observe a growth reduction that is larger than the mass accumulation rate of the nutrient. This indicates that if one particular nutrient is depleted, the cell rapidly adjusts the amount that other nutrients are accumulated, which is consistent with cooperative nutrient accumulation. Population measurements of nutrient sensing pathways involving mTOR, AKT, ERK, PKA, MST1, or AMPK, or pro-survival pathways involving autophagy suggest that they do not mediate this growth reduction. Furthermore, the protein synthesis rate does not change proportionally to the mass accumulation rate over these time scales, suggesting that intracellular metabolic pools buffer the growth response. Our findings demonstrate that cell growth can be regulated over much shorter time scales than previously appreciated. PMID:26620632

  17. Nutrient density in complementary feeding of infants and toddlers.

    PubMed

    Solomons, N W; Vossenaar, M

    2013-05-01

    The paradigm of the first 1000 days of life, the period from conception to the second birthday, has been advanced as a critical window of opportunity to save a life and a child's future. Infancy and toddler life, through the first 24 months after birth, is a unique period during which human milk is recommended as either the exclusive source of nutrition (6 months) or a variable component thereof. After the maternal delivery of milk is accounted for, the remainder of the energy and nutrients needs come from complementary foods. There is an intrinsic gap left by the maternal milk supply in volume and micronutrient content in relation to expanding infant and toddler needs. The nutrient density approach provides us with a mathematical framework to manage the closing of the nutrient gap. The intrinsic nutrient content of the unprocessed foods appropriate for young children is limited. The most problematic nutrients are calcium, iron and zinc. Some manner to enhance the nutrient density of the complementary foods is an incontestable necessity. The nutrient density consideration, which identifies for us the nature of the problem, offers a tool for the titrating of the fortification to an adequate--but safe--addition.

  18. Nutrients Distribution and Variability in the Arctic Basin

    NASA Astrophysics Data System (ADS)

    Smagin, V. M.; Timohov, L. A.; Colony, R.

    2003-04-01

    Arctic basin is characterized by sever climatic conditions, by presence of ice cover, by water exchange between the Atlantic and Pacific Oceans and the Arctic Ocean, by powerful river run off to the marginal seas, by atmospheric transport of various substances including nutrients, and by the unusual bottom relief, in particular by Lomonosov ridge dividing the Artic Basin on to two different parts. These factors and the various physical and biogeochemical process outline peculiar distribution and variability of nutrients in the Artic Basin. To study nutrients distribution and variability the expeditions data from 1906 to 2000 were used. These data were systemized in the USA - Russian Electronic Hydrochemical Atlas of the Arctic Ocean. As the result of data analysis, the spatial-temporal distribution of nutrients and their seasonal and interannual variability in the Artic Basin were presented. Minimum nutrients concentration is in the Eurasian basin, and maximum is in the Ameroasin basin. For example, Si concentration is 10 and 30 µg-at/l respectively. As to seasonal variability, nutrients concentration is several time less in summer in comparison with winter. The specific nutrients distribution during the Low and High Arctic Oscillation Index was shown.

  19. The Mauna Loa environmental matrix: foliar and soil nutrients

    USGS Publications Warehouse

    Vitousek, P.M.; Aplet, G.; Turner, D.; Lockwood, J.J.

    1992-01-01

    The accumulation of total carbon, nitrogen, and phosphorus in soils, available soil nutrients, and foliar nutrients in the native dominant Metrosideros polymorpha were determined across a wide elevational range on 9 lava flows on Mauna Loa, Hawai'i. The flows included a young (2800 y) a??a?? (rough surface texture) and pa??hoehoe (smooth) flow on the wet east and dry northwest side of the mountain. Soil element pools and nutrient availability increased with flow age independent of climate. The dry sites accumulated organic matter and nutrients more slowly than comparable wet sites, but relative nutrient availability to plants (as indicated by soil assays and foliar nutrients) was greater in the dry sites. Accumulation of soil organic matter and nutrients occurred most rapidly in lowerelevation sites on the young flows, but the largest accumulations occurred at higher elevations on old flows. The range of sites sampled represents a complete and largely independent matrix of major factors governing ecosystem structure and function. ?? 1992 Springer-Verlag.

  20. Water and nutrient acquisition by roots and canopies

    SciTech Connect

    Oren, R.; Sheriff, D.W.

    1995-07-01

    Water and nutrient supply rates, as well as internal (plant) and external (soil) deficits, can have major effects on physiological activity and growth. Effects of water or nutrient deficits on growth can be demonstrated separately, but they often interact, as shown for several Pinus species, and by Turner (1982) for Pinus radiata. Moist soil and wet canopy surfaces facilitate nutrient uptake through roots and foliage, respectively. Water uptake is affected by the number and distribution of roots in relation to the distribution of soil moisture, and by the wetness and hydraulic permeability of foliage. Nutrient uptake is similarly affected by tissue characteristics and nutrient concentration, but also depends on the moisture regime in the bulk soil and in the vicinity of absorbing surfaces. In this chapter, we discuss generalities based on results from observational studies of unmanipulated plants and of stands. We also consider information from experimental manipulation of nutrient and water availability. A more thorough treatment of the effects of mycorrhizae and anthropogenic pollution on water and nutrient acquisition is given, respectively.

  1. The nutrient characteristics of the Natal Bight, South Africa

    NASA Astrophysics Data System (ADS)

    Meyer, A. A.; Lutjeharms, J. R. E.; de Villiers, S.

    2002-06-01

    The Natal Bight is an unusually wide part of the continental shelf off southeastern Africa, bordered on its seaward side by the intense Agulhas Current. A description of the distribution of nutrients in the bight is given based on the first research cruise that has covered the whole region. It is shown that the main source of nutrients is the St. Lucia upwelling cell. From here, nutrient-rich water is carried southward over the northern part of the bight, particularly along the bottom. At the surface, this insertion of nutrients is accompanied by an increase in chlorophyll- a. Intermittent inflows of surface water from the Agulhas Current, particularly over the southern part of the bight, diminish the nutrient content of the waters there. A recurrent lee eddy off the southern termination of the Natal Bight upwells nutrients in its core. A simple model demonstrates that primary productivity may be sustained along the shelf edge by upwelling and that the southward flow of nutrients is affected by considerable mixing.

  2. The micro and macro of nutrients across biological scales.

    PubMed

    Warne, Robin W

    2014-11-01

    During the past decade, we have gained new insights into the profound effects that essential micronutrients and macronutrients have on biological processes ranging from cellular function, to whole-organism performance, to dynamics in ecological communities, as well as to the structure and function of ecosystems. For example, disparities between intake and organismal requirements for specific nutrients are known to strongly affect animal physiological performance and impose trade-offs in the allocations of resources. However, recent findings have demonstrated that life-history allocation trade-offs and even microevolutionary dynamics may often be a result of molecular-level constraints on nutrient and metabolic processing, in which limiting reactants are routed among competing biochemical pathways. In addition, recent work has shown that complex ecological interactions between organismal physiological states such as exposure to environmental stressors and infectious pathogens can alter organismal requirements for, and, processing of, nutrients, and even alter subsequent nutrient cycling in ecosystems. Furthermore, new research is showing that such interactions, coupled with evolutionary and biogeographical constraints on the biosynthesis and availability of essential nutrients and micronutrients play an important, but still under-studied role in the structuring and functioning of ecosystems. The purpose of this introduction to the symposium "The Micro and Macro of Nutrient Effects in Animal Physiology and Ecology" is to briefly review and highlight recent research that has dramatically advanced our understanding of how nutrients in their varied forms profoundly affect and shape ecological and evolutionary processes.

  3. Nutrient enrichment affects the mechanical resistance of aquatic plants

    PubMed Central

    Puijalon, Sara

    2012-01-01

    For many plant species, nutrient availability induces important anatomical responses, particularly the production of low-density tissues to the detriment of supporting tissues. Due to the contrasting biomechanical properties of plant tissues, these anatomical responses may induce important modifications in the biomechanical properties of plant organs. The aim of this study was to determine the effects of nutrient enrichment on the anatomical traits of two freshwater plant species and its consequences on plant biomechanical performance. Two plant species were grown under controlled conditions in low versus high nutrient levels. The anatomical and biomechanical traits of the plant stems were measured. Both species produced tissues with lower densities under nutrient-rich conditions, accompanied by modifications in the structure of the aerenchyma for one species. As expected, nutrient enrichment also led to important modifications in the biomechanical properties of the stem for both species. In particular, mechanical resistance (breaking force and strength) and stiffness of stems were significantly reduced under nutrient rich conditions. The production of weaker stem tissues as a result of nutrient enrichment may increase the risk of plants to mechanical failure, thus challenging plant maintenance in mechanically stressful or disturbed habitats. PMID:23028018

  4. Nutrient enrichment affects the mechanical resistance of aquatic plants.

    PubMed

    Lamberti-Raverot, Barbara; Puijalon, Sara

    2012-10-01

    For many plant species, nutrient availability induces important anatomical responses, particularly the production of low-density tissues to the detriment of supporting tissues. Due to the contrasting biomechanical properties of plant tissues, these anatomical responses may induce important modifications in the biomechanical properties of plant organs. The aim of this study was to determine the effects of nutrient enrichment on the anatomical traits of two freshwater plant species and its consequences on plant biomechanical performance. Two plant species were grown under controlled conditions in low versus high nutrient levels. The anatomical and biomechanical traits of the plant stems were measured. Both species produced tissues with lower densities under nutrient-rich conditions, accompanied by modifications in the structure of the aerenchyma for one species. As expected, nutrient enrichment also led to important modifications in the biomechanical properties of the stem for both species. In particular, mechanical resistance (breaking force and strength) and stiffness of stems were significantly reduced under nutrient rich conditions. The production of weaker stem tissues as a result of nutrient enrichment may increase the risk of plants to mechanical failure, thus challenging plant maintenance in mechanically stressful or disturbed habitats. PMID:23028018

  5. External nutrient sources, internal nutrient pools, and phytoplankton production in Chesapeake Bay

    SciTech Connect

    Magnien, R.E.; Summers, R.M. ); Sellner, K.G. )

    1992-12-01

    External nutrient loadings, internal nutrient pools, and phytoplankton production were examined for three major subsystems of the Chesapeake Bay Estuary-the upper Mainstem, the Patuxent Estuary, and the Potomac Estuary-during 1985-1989. The atomic nitrogen to phosphorus ratios (TN:TP) of total loads were 51, 29 and 35, respectively. Most of these loads entered at the head of the estuaries from riverine sources and major wastewater treatment plants. Seven-16% of the nitrogen load entered the head of each estuary as particulate matter in contrast to 48-69% for phosphorus. The difference seems to favor a greater loss of phosphorus than nitrogen through sedimentation and burial. A major storm event in the Potomac watershed greatly increased the particulate fraction of nitrogen and phosphorus and lowered the TN:TP in the river-borne loads and accounted for 11% of the nitrogen and 31% of the phosphorus delivered to the estuary by the Potomac River during the entire 60- month period examined here. Within the Mainstem estuary, salinity dilution plots revealed strong net sources of ammonium and phosphate in the oligohaline to upper mesohaline region. indicating considerable internal recycling of nutrients to surface waters. A net sink of nitrate was indicated during summer. Phytoplankton biomass in the mesohaline Mainstem reached a peak in spring and was relatively constant throughout the other seasons. In the Patuxent and Potomac, the TN:TP ratios of external loads are 2-4 times higher than those observed over the previous two decades. These changes are attributed to point-source phosphorus controls and the likelihood that nitrogen-rich nonpoint source inputs, including contributions from the atmosphere, have increased. These higher N:P ratios now suggest a greater overall potential for phosphorus-limitation rather than nitrogen-limitation of phytoplankton in the areas studied. 66 refs., 6 figs., 7 tabs.

  6. Fish-derived nutrient hotspots shape coral reef benthic communities.

    PubMed

    Shantz, Andrew A; Ladd, Mark C; Schrack, Elizabeth; Burkepile, Deron E

    2015-12-01

    Animal-derived nutrients play an important role in structuring nutrient regimes within and between ecosystems. When animals undergo repetitive, aggregating behavior through time, they can create nutrient hotspots where rates of biogeochemical activity are higher than those found in the surrounding environment. In turn, these hotspots can influence ecosystem processes and community structure. We examined the potential for reef fishes from the family Haemulidae (grunts) to create nutrient hotspots and the potential impact of these hotspots on reef communities. To do so, we tracked the schooling locations of diurnally migrating grunts, which shelter at reef sites during the day but forage off reef each night, and measured the impact of these fish schools on benthic communities. We found that grunt schools showed a high degree of site fidelity, repeatedly returning to the same coral heads. These aggregations created nutrient hotspots around coral heads where nitrogen and phosphorus delivery was roughly 10 and 7 times the respective rates of delivery to structurally similar sites that lacked schools of these fishes. In turn, grazing rates of herbivorous fishes at grunt-derived hotspots were approximately 3 times those of sites where grunts were rare. These differences in nutrient delivery and grazing led to distinct benthic communities with higher cover of crustose coralline algae and less total algal abundance at grunt aggregation sites. Importantly, coral growth was roughly 1.5 times greater at grunt hotspots, likely due to the important nutrient subsidy. Our results suggest that schooling reef fish and their nutrient subsidies play an important role in mediating community structure on coral reefs and that overfishing may have important negative consequences on ecosystem functions. As such, management strategies must consider mesopredatory fishes in addition to current protection often offered to herbivores and top-tier predators. Furthermore, our results suggest that

  7. Influence of nutrient level on methylmercury content in water spinach.

    PubMed

    Greger, Maria; Dabrowska, Beata

    2010-08-01

    Widely consumed vegetables are often cultivated in sewage waters with high nutrient levels. They can contain high levels of methylmercury (MeHg), because they can form MeHg from inorganic Hg in their young shoots. We determined whether the MeHg uptake and the MeHg formation in the shoots of water spinach (Ipomoea aquatica) were affected by the presence of a high nutrient level in the growth medium. Water spinach shoots were rooted and pretreated in growth medium containing 7% (low) or 70% (high) Hoagland nutrient solution; thereafter, the plants were treated with either 0.02 microM MeHg or 0.2 microM HgCl2 for 3 d. Half the plants were then analyzed for total Hg and MeHg. The remaining plants were transferred to mercury-free medium with low or high nutrient levels and posttreated for 3 days before analysis of total Hg and MeHg in order to measure MeHg formation in the absence of external Hg. The results indicate that nutrient level did not influence MeHg uptake, but that a high nutrient level reduced the distribution of MeHg to the shoots 2.7-fold versus low nutrient level. After treatment with HgCl2, MeHg was found in roots and new shoots but not in old shoots. The MeHg:total-Hg ratio was higher in new shoots than in roots, being 13 times higher at high versus low nutrient levels. Thus, MeHg formation was the same in new shoots independent of inorganic Hg concentration, since the total Hg level decreased at a high nutrient level.

  8. Global nutrient transport in a world of giants

    PubMed Central

    Doughty, Christopher E.; Roman, Joe; Faurby, Søren; Wolf, Adam; Haque, Alifa; Bakker, Elisabeth S.; Malhi, Yadvinder; Dunning, John B.; Svenning, Jens-Christian

    2016-01-01

    The past was a world of giants, with abundant whales in the sea and large animals roaming the land. However, that world came to an end following massive late-Quaternary megafauna extinctions on land and widespread population reductions in great whale populations over the past few centuries. These losses are likely to have had important consequences for broad-scale nutrient cycling, because recent literature suggests that large animals disproportionately drive nutrient movement. We estimate that the capacity of animals to move nutrients away from concentration patches has decreased to about 8% of the preextinction value on land and about 5% of historic values in oceans. For phosphorus (P), a key nutrient, upward movement in the ocean by marine mammals is about 23% of its former capacity (previously about 340 million kg of P per year). Movements by seabirds and anadromous fish provide important transfer of nutrients from the sea to land, totalling ∼150 million kg of P per year globally in the past, a transfer that has declined to less than 4% of this value as a result of the decimation of seabird colonies and anadromous fish populations. We propose that in the past, marine mammals, seabirds, anadromous fish, and terrestrial animals likely formed an interlinked system recycling nutrients from the ocean depths to the continental interiors, with marine mammals moving nutrients from the deep sea to surface waters, seabirds and anadromous fish moving nutrients from the ocean to land, and large animals moving nutrients away from hotspots into the continental interior. PMID:26504209

  9. Natural selection for costly nutrient recycling in simulated microbial metacommunities.

    PubMed

    Boyle, Richard A; Williams, Hywel T P; Lenton, Timothy M

    2012-11-01

    Recycling of essential nutrients occurs at scales from microbial communities to global biogeochemical cycles, often in association with ecological interactions in which two or more species utilise each others' metabolic by-products. However, recycling loops may be unstable; sequences of reactions leading to net recycling may be parasitised by side-reactions causing nutrient loss, while some reactions in any closed recycling loop are likely to be costly to participants. Here we examine the stability of nutrient recycling loops in an individual-based ecosystem model based on microbial functional types that differ in their metabolism. A supplied nutrient is utilised by a "source" functional type, generating a secondary nutrient that is subsequently used by two other types-a "mutualist" that regenerates the initial nutrient at a growth rate cost, and a "parasite" that produces a refractory waste product but does not incur any additional cost. The three functional types are distributed across a metacommunity in which separate patches are linked by a stochastic diffusive migration process. Regions of high mutualist abundance feature high levels of nutrient recycling and increased local population density leading to greater export of individuals, allowing the source-mutualist recycling loop to spread across the system. Individual-level selection favouring parasites is balanced by patch-level selection for high productivity, indirectly favouring mutualists due to the synergistic productivity benefits of the recycling loop they support. This suggests that multi-level selection may promote nutrient cycling and thereby help to explain the apparent ubiquity and stability of nutrient recycling in nature.

  10. Fish-derived nutrient hotspots shape coral reef benthic communities.

    PubMed

    Shantz, Andrew A; Ladd, Mark C; Schrack, Elizabeth; Burkepile, Deron E

    2015-12-01

    Animal-derived nutrients play an important role in structuring nutrient regimes within and between ecosystems. When animals undergo repetitive, aggregating behavior through time, they can create nutrient hotspots where rates of biogeochemical activity are higher than those found in the surrounding environment. In turn, these hotspots can influence ecosystem processes and community structure. We examined the potential for reef fishes from the family Haemulidae (grunts) to create nutrient hotspots and the potential impact of these hotspots on reef communities. To do so, we tracked the schooling locations of diurnally migrating grunts, which shelter at reef sites during the day but forage off reef each night, and measured the impact of these fish schools on benthic communities. We found that grunt schools showed a high degree of site fidelity, repeatedly returning to the same coral heads. These aggregations created nutrient hotspots around coral heads where nitrogen and phosphorus delivery was roughly 10 and 7 times the respective rates of delivery to structurally similar sites that lacked schools of these fishes. In turn, grazing rates of herbivorous fishes at grunt-derived hotspots were approximately 3 times those of sites where grunts were rare. These differences in nutrient delivery and grazing led to distinct benthic communities with higher cover of crustose coralline algae and less total algal abundance at grunt aggregation sites. Importantly, coral growth was roughly 1.5 times greater at grunt hotspots, likely due to the important nutrient subsidy. Our results suggest that schooling reef fish and their nutrient subsidies play an important role in mediating community structure on coral reefs and that overfishing may have important negative consequences on ecosystem functions. As such, management strategies must consider mesopredatory fishes in addition to current protection often offered to herbivores and top-tier predators. Furthermore, our results suggest that

  11. Where do the Nutrients go in Tropical Estuaries?

    NASA Astrophysics Data System (ADS)

    Ramachandran, R., VI

    2015-12-01

    Anthropogenic inputs of nutrients to the estuaries have rapidly increased during last couple of decades, resulting in deterioration of coastal water quality at regional scales. It is imperative to assess and quantify the ability of coastal systems to utilize, transport, and transform the 'excess' dissolved nutrients that enter the coast via land based activities. A LOICZ biogeochemical mass budget model was applied to the largest Indian estuary - the Ganges (Hooghly). Model studies indicate that despite high nutrient concentrations, the estuary remained net heterotrophic throughout the year. However if suspended particulate matter (SPM) was considered while estimating net metabolism, the system was net autotrophic. This model clearly highlights the influence of adsorption and desorption of nutrient and buffering action of SPM on nutrient dynamics under varying environmental conditions. Case studies from estuaries (e.g. Godavari and Tapi) and lagoon systems(Chilika and Vembanad) of India with differing levels of discharge and pollution were studied to determine the role of SPM on the trophic shift of these systems. Biogeochemical mass budget for all the systems suggested that in spite of high nutrient availability, high load of SPM (>100 mg L-1) controlled the trophic state and nutrient dynamics of a system. Indian estuaries and lagoons are predominantly heterotrophic, due to increasing anthrpogenic pressures from land based nutrient loading. The lagoon systems such as Chilika and Vembanad were predominantly heterotrophic and are a major source of phosphorus to the coastal waters. Overall, the source/sink characteristics of a system with respect to the adjacent coastal ocean were dependent on the in-situ biogeochemical processes (release, uptake and burial) and the residence time. The results further suggest that Hooghly estuary acts as a conduit of land-derived nutrients to the coastal ocean.

  12. Global nutrient transport in a world of giants.

    PubMed

    Doughty, Christopher E; Roman, Joe; Faurby, Søren; Wolf, Adam; Haque, Alifa; Bakker, Elisabeth S; Malhi, Yadvinder; Dunning, John B; Svenning, Jens-Christian

    2016-01-26

    The past was a world of giants, with abundant whales in the sea and large animals roaming the land. However, that world came to an end following massive late-Quaternary megafauna extinctions on land and widespread population reductions in great whale populations over the past few centuries. These losses are likely to have had important consequences for broad-scale nutrient cycling, because recent literature suggests that large animals disproportionately drive nutrient movement. We estimate that the capacity of animals to move nutrients away from concentration patches has decreased to about 8% of the preextinction value on land and about 5% of historic values in oceans. For phosphorus (P), a key nutrient, upward movement in the ocean by marine mammals is about 23% of its former capacity (previously about 340 million kg of P per year). Movements by seabirds and anadromous fish provide important transfer of nutrients from the sea to land, totalling ∼150 million kg of P per year globally in the past, a transfer that has declined to less than 4% of this value as a result of the decimation of seabird colonies and anadromous fish populations. We propose that in the past, marine mammals, seabirds, anadromous fish, and terrestrial animals likely formed an interlinked system recycling nutrients from the ocean depths to the continental interiors, with marine mammals moving nutrients from the deep sea to surface waters, seabirds and anadromous fish moving nutrients from the ocean to land, and large animals moving nutrients away from hotspots into the continental interior. PMID:26504209

  13. Internal nutrient sources and nutrient distributions in Alviso Pond A3W, California

    USGS Publications Warehouse

    Topping, Brent R.; Kuwabara, James S.; Garrett, Krista K.; Takekawa, John Y.; Parcheso, Francis; Piotter, Sara; Clearwater, Iris; Shellenbarger, Gregory

    2013-01-01

    Within the Alviso Salt Pond complex, California, currently undergoing avian-habitat restoration, pore-water profilers (U.S. Patent 8,051,727 B1) were deployed in triplicate at two contrasting sites in Pond A3W (“Inlet”, near the inflow, and “Deep”, near the middle of the pond; figs. 1 and 2; table 1, note that tables in this report are provided online only as a .xlsx workbook at http://pubs.usgs.gov/of/2013/1128/). Deployments were conducted in 2010 and 2012 during the summer algal-growth season. Specifically, three deployments, each about 7 weeks apart, were undertaken each summer. This study provides the first measurements of the diffusive flux of nutrients across the interface between the pond bed and water column (that is, benthic nutrient flux). These nutrient fluxes are crucial to pond restoration efforts because they typically represent a major (if not the greatest) source of nutrients to the water column in both ponds and other lentic systems. For soluble reactive phosphorus (SRP, the most biologically available form in solution), benthic flux was positive both years (that is, out of the sediment into the water column; table 2), with the exception of the August 2010 deployment, which exhibited nearly negligible but negative flux. Overall, the average SRP flux was significantly greater at Deep (23.9 ± 8.6 micromoles per square meter per hour (µmol-m-2-h-1); all errors shown reflect the 95-percent confidence interval) than Inlet (12.6 ± 4.9 µmol-m-2-h-1). There was much greater temporal variability in SRP flux in the pond than reported for the lower estuary (Topping and others, 2001). For dissolved ammonia, benthic flux was consistently positive on all six sampling trips, and similar to SRP, the fluxes at Deep (258 ± 49 µmol-m-2-h-1) were consistently greater than those at Inlet (28 ± 11 µmol-m-2-h-1). Dissolved ammonia fluxes reported for South San Francisco Bay by Topping and others (2001) fall in between these values. Once again, greater

  14. SUSPENDED AND BENTHIC SEDIMENT RELATIONSHIPS IN THE YAQUINA ESTUARY, OREGON: NUTRIENT PROCESSING

    EPA Science Inventory

    Measurements of nutrient loading and subsequent nutrient processing are fundamental for determining biogeochemical processes in rivers and estuaries. In Oregon coastal watersheds, nutrient transport is strongly seasonal with up to 94% of the riverine dissolved nitrate and silic...

  15. Coping with uncertainty: Nutrient deficiencies motivate insect migration at a cost to immunity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Migration is often associated with movement away from areas with depleted nutrients or other resources, and yet migration itself is energetically demanding. Migrating Mormon crickets Anabrus simplex (Orthoptera: Tettigoniidae) lack nutrients, and supplementation of deficient nutrients slows migrator...

  16. Effect of polycarbophil on the absorption of nutrients.

    PubMed

    Yamada, T; Nagata, O; Tamai, I; Tsuji, A

    1996-05-01

    The effects of polycarbophil on the absorption of various nutrients were evaluated by several in situ methods. Polycarbophil reduced the absorption of 3-O-methyl-D-glucose (3-OMG) and L-phenylalanine in the in situ loop and the in situ perfusion methods, but it did not affect the absorption of these nutrients in an open system, the in situ modified loop method, which is closer to physiological conditions. It also did not affect the absorption of vitamin A or phosphatidylcholine-L-alpha-dipalmitoyl in the latter system. These results indicate that the absorption of nutrients is probably not altered by polycarbophil under physiological conditions.

  17. Hydroponic Crop Production using Recycled Nutrients from Inedible Crop Residues

    NASA Technical Reports Server (NTRS)

    Garland, Jay L.; Mackowiak, Cheryl L.; Sager, John C.

    1993-01-01

    The coupling of plant growth and waste recycling systems is an important step toward the development of bioregenerative life support systems. This research examined the effectiveness of two alternative methods for recycling nutrients from the inedible fraction (residue) of candidate crops in a bioregenerative system as follows: (1) extraction in water, or leaching, and (2) combustion at 550 C, with subsequent reconstitution of the ash in acid. The effectiveness of the different methods was evaluated by (1) comparing the percent recovery of nutrients, and (2) measuring short- and long-term plant growth in hydroponic solutions, based on recycled nutrients.

  18. Controlled environments alter nutrient content of soybeans

    NASA Astrophysics Data System (ADS)

    Jurgonski, L. J.; Smart, D. J.; Bugbee, B.; Nielsen, S. S.

    1997-01-01

    Information about compositional changes in plants grown in controlled environments is essential for developing a safe, nutritious diet for a Controlled Ecological Life-Support System (CELSS). Information now is available for some CELSS candidate crops, but detailed information has been lacking for soybeans. To determine the effect of environment on macronutrient and mineral composition of soybeans, plants were grown both in the field and in a controlled environment where the hydroponic nutrient solution, photosynthetic flux (PPF), and CO_2 level were manipulated to achieve rapid growth rates. Plants were harvested at seed maturity, separated into discrete parts, and oven dried prior to chemical analysis. Plant material was analyzed for proximate composition (moisture, protein, lipid, ash, and carbohydrate), total nitrogen (N), nonprotein N (NPN), nitrate, minerals, amino acid composition, and total dietary fiber. The effect of environment on composition varied by cultivar and plant part. Chamber-grown plants generally exhibited the following characteristics compared with field-grown plants: 1) increased total N and protein N for all plant parts, 2) increased nitrate in leaves and stems but not in seeds, 3) increased lipids in seeds, and 4) decreased Ca:P ratio for stems, pods, and leaves. These trends are consistent with data for other CELSS crops. Total N, protein N, and amino acid contents for 350 ppm CO_2 and 1000 ppm CO_2 were similar for seeds, but protein N and amino acid contents for leaves were higher at 350 ppm CO_2 than at 1000 ppm CO_2. Total dietary fiber content of soybean leaves was higher with 350 ppm CO_2 than with 1000 ppm CO_2. Such data will help in selecting of crop species, cultivars, and growing conditions to ensure safe, nutritious diets for CELSS.

  19. Response of algal metrics to nutrients and physical factors and identification of nutrient thresholds in agricultural streams

    USGS Publications Warehouse

    Black, R.W.; Moran, P.W.; Frankforter, J.D.

    2011-01-01

    Many streams within the United States are impaired due to nutrient enrichment, particularly in agricultural settings. The present study examines the response of benthic algal communities in agricultural and minimally disturbed sites from across the western United States to a suite of environmental factors, including nutrients, collected at multiple scales. The first objective was to identify the relative importance of nutrients, habitat and watershed features, and macroinvertebrate trophic structure to explain algal metrics derived from deposition and erosion habitats. The second objective was to determine if thresholds in total nitrogen (TN) and total phosphorus (TP) related to algal metrics could be identified and how these thresholds varied across metrics and habitats. Nutrient concentrations within the agricultural areas were elevated and greater than published threshold values. All algal metrics examined responded to nutrients as hypothesized. Although nutrients typically were the most important variables in explaining the variation in each of the algal metrics, environmental factors operating at multiple scales also were important. Calculated thresholds for TN or TP based on the algal metrics generated from samples collected from erosion and deposition habitats were not significantly different. Little variability in threshold values for each metric for TN and TP was observed. The consistency of the threshold values measured across multiple metrics and habitats suggest that the thresholds identified in this study are ecologically relevant. Additional work to characterize the relationship between algal metrics, physical and chemical features, and nuisance algal growth would be of benefit to the development of nutrient thresholds and criteria. ?? 2010 The Author(s).

  20. Changes in phytoplankton communities along nutrient gradients in Lake Taihu: evidence for nutrient reduction strategies

    NASA Astrophysics Data System (ADS)

    Ai, Ying; Bi, Yonghong; Hu, Zhengyu

    2015-03-01

    An annual investigation on phytoplankton communities was conducted to reveal the effects of nutrients on phytoplankton assemblages in Lake Taihu, East China. A total of 78 phytoplankton taxa were identified. Phytoplankton biomass was higher in the northern part of the lake than in the southern part. Cyanobacteria and Bacillariophyta alternated dominance in the northern area, where algal blooms often appear, and co-dominated in the southern area. In the northern part, the proportions of cyanobacteria and Bacillariophyta varied significantly in total biovolume, both along the phosphorus (P) gradient, and between total nitrogen levels (≤3 mg/L and >3 mg/L TN). The proportions of cyanobacteria and Bacillariophyta had no significant variations in total biovolume along P and N (nitrogen) gradients in the southern part. Correlation analysis and CCA results revealed that P was the key factor regulating phytoplankton community structure. Nitrogen was also important for the phytoplankton distribution pattern. It was concluded that nutrient structure was heterogeneous in space and shaped the distribution pattern of phytoplankton in the lake. Both exogenous P and internally sourced P release needs to be considered. N reduction should be considered simultaneously with P control to efficiently reduce eutrophication and algal blooms.

  1. Nutrient load summaries for major lakes and estuaries of the Eastern United States, 2002

    USGS Publications Warehouse

    Moorman, Michelle C.; Hoos, Anne B.; Bricker, Suzanne B.; Moore, Richard B.; García, Ana María; Ator, Scott W.

    2014-01-01

    Nutrient enrichment of lakes and estuaries across the Nation is widespread. Nutrient enrichment can stimulate excessive plant and algal growth and cause a number of undesirable effects that impair aquatic life and recreational activities and can also result in economic effects. Understanding the amount of nutrients entering lakes and estuaries, the physical characteristics affecting the nutrient processing within these receiving waterbodies, and the natural and manmade sources of nutrients is fundamental to the development of effective nutrient reduction strategies. To improve this understanding, sources and stream transport of nutrients to 255 major lakes and 64 estuaries in the Eastern United States were estimated using Spatially Referenced Regression on Watershed attributes (SPARROW) nutrient models.

  2. Gustatory and metabolic perception of nutrient stress in Drosophila

    PubMed Central

    Linford, Nancy J.; Ro, Jennifer; Chung, Brian Y.; Pletcher, Scott D.

    2015-01-01

    Sleep loss is an adaptive response to nutrient deprivation that alters behavior to maximize the chances of feeding before imminent death. Organisms must maintain systems for detecting the quality of the food source to resume healthy levels of sleep when the stress is alleviated. We determined that gustatory perception of sweetness is both necessary and sufficient to suppress starvation-induced sleep loss when animals encounter nutrient-poor food sources. We further find that blocking specific dopaminergic neurons phenocopies the absence of gustatory stimulation, suggesting a specific role for these neurons in transducing taste information to sleep centers in the brain. Finally, we show that gustatory perception is required for survival, specifically in a low nutrient environment. Overall, these results demonstrate an important role for gustatory perception when environmental food availability approaches zero and illustrate the interplay between sensory and metabolic perception of nutrient availability in regulating behavioral state. PMID:25675472

  3. ANALYSIS OF PARTICULATE BOUND NUTRIENTS IN URBAN STORMWATER

    EPA Science Inventory

    Nutrients are important players in the degradation of waterbodies because they are often the elements that limit primary productivity and, hence, are the key factors controlling eutrophication. Eutrophication causes unsightly algal blooms leading to oxygen depletion, stress on o...

  4. Herbivores and nutrients control grassland plant diversity via light limitation

    USGS Publications Warehouse

    Borer, Elizabeth T.; Seabloom, Eric W.; Gruner, Daniel S.; Harpole, W. Stanley; Hillebrand, Helmut; Lind, Eric M.; Alder, Peter B.; Alberti, Juan; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori; Blumenthal, Dana; Brown, Cynthia S.; Brudvig, Lars A.; Buckley, Yvonne M.; Cadotte, Marc; Chu, Cheng-Jin; Cleland, Elsa E.; Crawley, Michael J.; Daleo, Pedro; Damschen, Ellen Ingman; Davies, Kendi F.; DeCrappeo, Nicole M.; Du, Guozhen; Firn, Jennifer; Hautier, Yann; Heckman, Robert W.; Hector, Andy; HilleRisLambers, Janneke; Iribarne, Oscar; Klein, Julia A.; Knops, Johannes M.H.; La Pierre, Kimberly J.; Leakey, Andrew D.B.; Li, Wei; MacDougall, Andrew S.; McCulley, Rebecca L.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Mortensen, Brent; O'Halloran, Lydia R.; Orrock, John L.; Pascual, Jesús; Prober, Suzanne M.; Pyke, David A.; Risch, Anita C.; Schuetz, Martin; Smith, Melinda D.; Stevens, Carly J.; Sullivan, Lauren L.; Williams, Ryan J.; Wragg, Peter D.; Wright, Justin P.; Yang, Louie H.

    2014-01-01

    Human alterations to nutrient cycles and herbivore communities are affecting global biodiversity dramatically. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems. Here we use experimental data spanning a globally relevant range of conditions to test the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory. This experiment, replicated in 40 grasslands on 6 continents, demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant diversity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate. Nutrient addition consistently reduced local diversity through light limitation, and herbivory rescued diversity at sites where it alleviated light limitation. Thus, species loss from anthropogenic eutrophication can be ameliorated in grasslands where herbivory increases ground-level light.

  5. Nutrient enrichment of the subarctic Pacific Ocean pycnocline

    NASA Astrophysics Data System (ADS)

    Whitney, Frank A.; Bograd, Steven J.; Ono, Tsuneo

    2013-05-01

    At the end of the global thermohaline circulation, the subarctic Pacific is the richest nutrient repository in the world oceans. Trends towards lower oxygen and higher nutrients in waters below the surface layer (the pycnocline) have been observed in recent decades. We assess these trends using data from four programs and suggest the enrichment of pycnocline nitrate (200 Gmol y-1) is essential in keeping supply to the surface ocean constant, despite increasing upper ocean stratification. A nitrate budget helps identify possible vertical processes that could account for nutrient redistribution. We hypothesize that warming and oxygen loss in the deeper pycnocline, arising from ice loss in the Okhotsk Sea, have initiated a largely vertical redistribution of nutrients due to compression of vertical migrator habitat and/or changes in dissolution of sinking particulates. Coupled climate-ecosystem models will need to incorporate these processes to more fully understand projected changes in the subarctic Pacific.

  6. Nutrient environment influences competition among Aspergillus flavus genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Structures of Aspergillus flavus populations, shaped by intraspecific competition, influence the incidences and severities of crop aflatoxin contamination. Competition for nutrients may be one factor modulating intraspecific interactions, but influences of specific types and concentrations of nutrie...

  7. Diet History Questionnaire: Development of the DHQ Nutrient Database

    Cancer.gov

    The nutrient and food group database, created for analyzing the DHQ, is based on national dietary intake data from the 1994-96 US Department of Agriculture's Continuing Survey of Food Intake by Individuals (CSFII).

  8. Nutrient removal from swine lagoon effluent by duckweed

    SciTech Connect

    Bergmann, B.A.; Cheng, J.; Classen, J.; Stomp, A.M.

    2000-04-01

    Three duckweed geographic isolates were grown on varying concentrations of swine lagoon effluent in a greenhouse to determine their ability to remove nutrients from the effluent. Duckweed biomass was harvested every other day over a 12-day period. Duckweed biomass production, nutrient loss from the swine lagoon effluent, and nutrient content of duckweed biomass were used to identify effluent concentrations/geographic isolate combinations that are effective in terms of nutrient utilization from swine lagoon effluent and production of healthy duckweed biomass. When Lemna minor geographic isolate 8627 was grown on 50% swine lagoon effluent, respective losses of TKN, NH{sub 3}-N, TP, OPO{sub 4}-P, TOC, K, Cu, and Zn were 83, 100, 49, 31, 68, 21, 28 and 67%.

  9. Marsh Soil Responses to Nutrients: Belowground Structural and Organic Properties

    EPA Science Inventory

    Coastal marsh responses to nutrient enrichment apparently depend upon soil matrix and whether the system is primarily biogenic or minerogenic. Deteriorating organic rich marshes (Jamaica Bay, NY) receiving wastewater effluent had lower belowground biomass, organic matter, and soi...

  10. Marsh Soil Responses to Nutrients: Belowground Structural and Organic Properties.

    EPA Science Inventory

    Coastal marsh responses to nutrient enrichment apparently depend upon soil matrix and whether the system is primarily biogenic or minerogenic. Deteriorating organic rich marshes (Jamaica Bay, NY) receiving wastewater effluent had lower belowground biomass, organic matter, and soi...

  11. Herbivores and nutrients control grassland plant diversity via light limitation.

    PubMed

    Borer, Elizabeth T; Seabloom, Eric W; Gruner, Daniel S; Harpole, W Stanley; Hillebrand, Helmut; Lind, Eric M; Adler, Peter B; Alberti, Juan; Anderson, T Michael; Bakker, Jonathan D; Biederman, Lori; Blumenthal, Dana; Brown, Cynthia S; Brudvig, Lars A; Buckley, Yvonne M; Cadotte, Marc; Chu, Chengjin; Cleland, Elsa E; Crawley, Michael J; Daleo, Pedro; Damschen, Ellen I; Davies, Kendi F; DeCrappeo, Nicole M; Du, Guozhen; Firn, Jennifer; Hautier, Yann; Heckman, Robert W; Hector, Andy; HilleRisLambers, Janneke; Iribarne, Oscar; Klein, Julia A; Knops, Johannes M H; La Pierre, Kimberly J; Leakey, Andrew D B; Li, Wei; MacDougall, Andrew S; McCulley, Rebecca L; Melbourne, Brett A; Mitchell, Charles E; Moore, Joslin L; Mortensen, Brent; O'Halloran, Lydia R; Orrock, John L; Pascual, Jesús; Prober, Suzanne M; Pyke, David A; Risch, Anita C; Schuetz, Martin; Smith, Melinda D; Stevens, Carly J; Sullivan, Lauren L; Williams, Ryan J; Wragg, Peter D; Wright, Justin P; Yang, Louie H

    2014-04-24

    Human alterations to nutrient cycles and herbivore communities are affecting global biodiversity dramatically. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems. Here we use experimental data spanning a globally relevant range of conditions to test the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory. This experiment, replicated in 40 grasslands on 6 continents, demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant diversity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate. Nutrient addition consistently reduced local diversity through light limitation, and herbivory rescued diversity at sites where it alleviated light limitation. Thus, species loss from anthropogenic eutrophication can be ameliorated in grasslands where herbivory increases ground-level light.

  12. Herbivores and nutrients control grassland plant diversity via light limitation.

    PubMed

    Borer, Elizabeth T; Seabloom, Eric W; Gruner, Daniel S; Harpole, W Stanley; Hillebrand, Helmut; Lind, Eric M; Adler, Peter B; Alberti, Juan; Anderson, T Michael; Bakker, Jonathan D; Biederman, Lori; Blumenthal, Dana; Brown, Cynthia S; Brudvig, Lars A; Buckley, Yvonne M; Cadotte, Marc; Chu, Chengjin; Cleland, Elsa E; Crawley, Michael J; Daleo, Pedro; Damschen, Ellen I; Davies, Kendi F; DeCrappeo, Nicole M; Du, Guozhen; Firn, Jennifer; Hautier, Yann; Heckman, Robert W; Hector, Andy; HilleRisLambers, Janneke; Iribarne, Oscar; Klein, Julia A; Knops, Johannes M H; La Pierre, Kimberly J; Leakey, Andrew D B; Li, Wei; MacDougall, Andrew S; McCulley, Rebecca L; Melbourne, Brett A; Mitchell, Charles E; Moore, Joslin L; Mortensen, Brent; O'Halloran, Lydia R; Orrock, John L; Pascual, Jesús; Prober, Suzanne M; Pyke, David A; Risch, Anita C; Schuetz, Martin; Smith, Melinda D; Stevens, Carly J; Sullivan, Lauren L; Williams, Ryan J; Wragg, Peter D; Wright, Justin P; Yang, Louie H

    2014-04-24

    Human alterations to nutrient cycles and herbivore communities are affecting global biodiversity dramatically. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems. Here we use experimental data spanning a globally relevant range of conditions to test the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory. This experiment, replicated in 40 grasslands on 6 continents, demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant diversity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate. Nutrient addition consistently reduced local diversity through light limitation, and herbivory rescued diversity at sites where it alleviated light limitation. Thus, species loss from anthropogenic eutrophication can be ameliorated in grasslands where herbivory increases ground-level light. PMID:24670649

  13. Nutrient cycling and plant dynamics in estuaries: A brief review

    NASA Astrophysics Data System (ADS)

    Flindt, Mogens R.; Pardal, Miguel Ângelo; Lillebø, Ana Isabel; Martins, Irene; Marques, João Carlos

    1999-07-01

    Eutrophication of European estuaries due to massive nutrient loading from urban areas and diffuse runoff from extensively cultivated land areas is analysed. Consequences for the ecology of estuaries, namely changes in plant species composition, which also affects heterotrophic organisms, are approached based on examples showing that the result is often a fundamental structural change of the ecosystem, from a grazing and/or nutrient controlled stable systems to unstable detritus/mineralisation systems, where the turnover of oxygen and nutrients is much more dynamic and oscillations between aerobic and anaerobic states frequently occur. Several relevant aspects are examined, namely the influence of rooted macrophytes on nutrient dynamics, by comparing bare bottom sediments with eelgrass covered sediments, primary production and the development of organic detritus, and hydrodynamics and its relations to the spatial distribution of macrophytes in estuarine systems.

  14. Calcification generates protons for nutrient and bicarbonate uptake

    NASA Astrophysics Data System (ADS)

    McConnaughey, T. A.; Whelan, J. F.

    1997-03-01

    The biosphere's great carbonate deposits, from caliche soils to deep-sea carbonate oozes, precipitate largely as by-products of autotrophic nutrient acquisition physiologies. Protons constitute the critical link: Calcification generates protons, which plants and photosynthetic symbioses use to assimilate bicarbonate and nutrients. A calcium ATPase-based "trans" mechanism underlies most biological calcification. This permits high calcium carbonate supersaturations and rapid carbonate precipitation. The competitive advantages of calcification become especially apparent in light and nutrient-deficient alkaline environments. Calcareous plants often dominate the lower euphotic zone in both the benthos and the plankton. Geographically and seasonally, massive calcification concentrates in nutrient-deficient environments including alkaline soils, coral reefs, cyanobacterial mats and coccolithophorid blooms. Structural and defensive uses for calcareous skeletons are sometimes overrated.

  15. Geostatistical analyses reveal nutrient-vegetation relationships in savanna soils

    NASA Astrophysics Data System (ADS)

    Mladenov, N.; Okin, G. S.; Cassel, D.; Caylor, K. C.; Clausen, K. M.

    2005-12-01

    The uniform Kalahari sands that underlay the Kalahari Transect (KT) are a unique test bed for examining soil nutrient and vegetation cover relationships in a savanna ecosystem. Transects (300m x 100m) were sampled and mapped for each of four sites located along an aridity gradient from Mongu, Zambia in the north (1600 mm/yr precipitation), to Tshane, Botswana in the south (250 mm/yr precipitation). Geostatistical analyses of soil chemistry and tree, shrub, and grass cover at four sites along the moisture gradient of the KT indicated an accumulation of nutrients below tree/shrub cover. In general, areas where grasses dominated between canopies were negatively correlated with soil nutrients at the drier sites. Here we examine effects of vegetation cover on soil productivity and differences in soil nutrients along the moisture gradient of the KT.

  16. Evaluating nutrient impacts in urban watersheds: challenges and research opportunities.

    PubMed

    Carey, Richard O; Hochmuth, George J; Martinez, Christopher J; Boyer, Treavor H; Dukes, Michael D; Toor, Gurpal S; Cisar, John L

    2013-02-01

    This literature review focuses on the prevalence of nitrogen and phosphorus in urban environments and the complex relationships between land use and water quality. Extensive research in urban watersheds has broadened our knowledge about point and non-point pollutant sources, but the fate of nutrients is not completely understood. For example, it is not known how long-term nutrient cycling processes in turfgrass landscapes influence nitrogen retention rates or the relative atmospheric contribution to urban nitrogen exports. The effect of prolonged reclaimed water irrigation is also unknown. Stable isotopes have been used to trace pollutants, but distinguishing sources (e.g., fertilizers, wastewater, etc.) can be difficult. Identifying pollutant sources may aid our understanding of harmful algal blooms because the extent of the relationship between urban nutrient sources and algal blooms is unclear. Further research on the delivery and fate of nutrients within urban watersheds is needed to address manageable water quality impacts. PMID:23202644

  17. Ozone alters the concentrations of nutrients in bean tissue

    SciTech Connect

    Tingey, D.T.; Rodecap, K.D.; Lee, E.H.; Moser, T.J.; Hogsett, W.E.

    1986-01-01

    Studies were conducted to determine the impact of ozone on the nutrient concentrations in tissue from various organs of beans (Phaseolus vulgaris L. cv Bush Bluelake 290). The plants were exposed to episodic concentrations of ozone in open-top field exposure chambers from soon after emergence until pod maturity. At harvest the leaf, stem, root and pod tissue were separated and dried (at 70C) to a constant weight. Nutrient concentrations in the tissue were determined using an inductively coupled plasma atomic emission spectrometer. Ozone exposure decreased the foliar concentrations of only four of the twelve nutrients analyzed (Ca, Mg, Fe and Mn) and increased the concentrations of three nutrients (K,P and Mo) in the pods. There were no significant changes in the macro- or micronutrient levels in the stem or root tissue. The decreased concentrations in the foliage appear to be the result of reduced transport into the leaves rather than reduced uptake or leaching.

  18. Dietary guidance and nutrient requirements of the elderly.

    PubMed

    Wellman, N S

    1994-03-01

    Basic practical advice about healthy food choices is reviewed via the Dietary Guidelines for Americans, the Food Guide Pyramid, and Daily Values on Food Labels. Special considerations for their use with the healthy elderly are included. Nutrient requirements of the elderly are presented for the oldest RDA age category, "51+ years and older" as is newer research on altered nutrient needs that accompany aging. The Nutrition Counseling Checklist helps determine when referral for in-depth diet therapy is needed. PMID:8197248

  19. The relationships of nutrients, routes of delivery, and immunocompetence.

    PubMed

    Jayarajan, Senthil; Daly, John M

    2011-08-01

    Malnutrition has marked consequences on surgical outcomes. Adequate nutrition is important for the proper functioning of all organ systems, particularly the immune system. Determination of the type and amount of nutrient supplementation and the appropriate route of nutrient delivery is essential to bolster the immune system and enhance the host's response to stress. Correct administration of immunonutrients could lead to reductions in patient morbidity following major surgery, trauma, and critical illness.

  20. 9 CFR 317.313 - Nutrient content claims; general principles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... formulas and medical foods, as described in 21 CFR 101.13(q)(4). (5) (6) Nutrient content claims that were... product, e.g., “low sodium” or “contains 100 calories.” (2) An implied nutrient content claim is any claim... misleading in any respect (e.g., “100 calories” or “5 grams of fat”), in which case no disclaimer is...

  1. Selection of optimal auxiliary soil nutrient variables for Cokriging interpolation.

    PubMed

    Song, Genxin; Zhang, Jing; Wang, Ke

    2014-01-01

    In order to explore the selection of the best auxiliary variables (BAVs) when using the Cokriging method for soil attribute interpolation, this paper investigated the selection of BAVs from terrain parameters, soil trace elements, and soil nutrient attributes when applying Cokriging interpolation to soil nutrients (organic matter, total N, available P, and available K). In total, 670 soil samples were collected in Fuyang, and the nutrient and trace element attributes of the soil samples were determined. Based on the spatial autocorrelation of soil attributes, the Digital Elevation Model (DEM) data for Fuyang was combined to explore the coordinate relationship among terrain parameters, trace elements, and soil nutrient attributes. Variables with a high correlation to soil nutrient attributes were selected as BAVs for Cokriging interpolation of soil nutrients, and variables with poor correlation were selected as poor auxiliary variables (PAVs). The results of Cokriging interpolations using BAVs and PAVs were then compared. The results indicated that Cokriging interpolation with BAVs yielded more accurate results than Cokriging interpolation with PAVs (the mean absolute error of BAV interpolation results for organic matter, total N, available P, and available K were 0.020, 0.002, 7.616, and 12.4702, respectively, and the mean absolute error of PAV interpolation results were 0.052, 0.037, 15.619, and 0.037, respectively). The results indicated that Cokriging interpolation with BAVs can significantly improve the accuracy of Cokriging interpolation for soil nutrient attributes. This study provides meaningful guidance and reference for the selection of auxiliary parameters for the application of Cokriging interpolation to soil nutrient attributes.

  2. Selection of Optimal Auxiliary Soil Nutrient Variables for Cokriging Interpolation

    PubMed Central

    Song, Genxin; Zhang, Jing; Wang, Ke

    2014-01-01

    In order to explore the selection of the best auxiliary variables (BAVs) when using the Cokriging method for soil attribute interpolation, this paper investigated the selection of BAVs from terrain parameters, soil trace elements, and soil nutrient attributes when applying Cokriging interpolation to soil nutrients (organic matter, total N, available P, and available K). In total, 670 soil samples were collected in Fuyang, and the nutrient and trace element attributes of the soil samples were determined. Based on the spatial autocorrelation of soil attributes, the Digital Elevation Model (DEM) data for Fuyang was combined to explore the coordinate relationship among terrain parameters, trace elements, and soil nutrient attributes. Variables with a high correlation to soil nutrient attributes were selected as BAVs for Cokriging interpolation of soil nutrients, and variables with poor correlation were selected as poor auxiliary variables (PAVs). The results of Cokriging interpolations using BAVs and PAVs were then compared. The results indicated that Cokriging interpolation with BAVs yielded more accurate results than Cokriging interpolation with PAVs (the mean absolute error of BAV interpolation results for organic matter, total N, available P, and available K were 0.020, 0.002, 7.616, and 12.4702, respectively, and the mean absolute error of PAV interpolation results were 0.052, 0.037, 15.619, and 0.037, respectively). The results indicated that Cokriging interpolation with BAVs can significantly improve the accuracy of Cokriging interpolation for soil nutrient attributes. This study provides meaningful guidance and reference for the selection of auxiliary parameters for the application of Cokriging interpolation to soil nutrient attributes. PMID:24927129

  3. Review of nutrient actions on age-related macular degeneration.

    PubMed

    Zampatti, Stefania; Ricci, Federico; Cusumano, Andrea; Marsella, Luigi Tonino; Novelli, Giuseppe; Giardina, Emiliano

    2014-02-01

    The actions of nutrients and related compounds on age-related macular degeneration (AMD) are explained in this review. The findings from 80 studies published since 2003 on the association between diet and supplements in AMD were reviewed. Antioxidants and other nutrients with an effect on AMD susceptibility include carotenoids (lutein and zeaxanthin, β-carotene), vitamins (vitamin A, E, C, D, B), mineral supplements (zinc, copper, selenium), dietary fatty acids [monounsaturated fatty acids, polyunsaturated fatty acids (PUFA both omega-3 PUFA and omega-6 PUFA), saturated fatty acids and cholesterol], and dietary carbohydrates. The literature revealed that many of these antioxidants and nutrients exert a protective role by functioning synergistically. Specifically, the use of dietary supplements with targeted actions can provide minimal benefits on the onset or progression of AMD; however, this does not appear to be particularly beneficial in healthy people. Furthermore, some supplements or nutrients have demonstrated discordant effects on AMD in some studies. Since intake of dietary supplements, as well as exposure to damaging environmental factors, is largely dependent on population habits (including dietary practices) and geographical localization, an overall healthy diet appears to be the best strategy in reducing the risk of developing AMD. As of now, the precise mechanism of action of certain nutrients in AMD prevention remains unclear. Thus, future studies are required to examine the effects that nutrients have on AMD and to determine which factors are most strongly correlated with reducing the risk of AMD or preventing its progression. PMID:24461310

  4. Nutrient density of beverages in relation to climate impact

    PubMed Central

    Smedman, Annika; Lindmark-Månsson, Helena; Drewnowski, Adam; Edman, Anna-Karin Modin

    2010-01-01

    The food chain contributes to a substantial part of greenhouse gas (GHG) emissions and growing evidence points to the urgent need to reduce GHGs emissions worldwide. Among suggestions were proposals to alter food consumption patterns by replacing animal foods with more plant-based foods. However, the nutritional dimensions of changing consumption patterns to lower GHG emissions still remains relatively unexplored. This study is the first to estimate the composite nutrient density, expressed as percentage of Nordic Nutrition Recommendations (NNR) for 21 essential nutrients, in relation to cost in GHG emissions of the production from a life cycle perspective, expressed in grams of CO2-equivalents, using an index called the Nutrient Density to Climate Impact (NDCI) index. The NDCI index was calculated for milk, soft drink, orange juice, beer, wine, bottled carbonated water, soy drink, and oat drink. Due to low-nutrient density, the NDCI index was 0 for carbonated water, soft drink, and beer and below 0.1 for red wine and oat drink. The NDCI index was similar for orange juice (0.28) and soy drink (0.25). Due to a very high-nutrient density, the NDCI index for milk was substantially higher (0.54) than for the other beverages. Future discussion on how changes in food consumption patterns might help avert climate change need to take both GHG emission and nutrient density of foods and beverages into account. PMID:20806074

  5. Fish extinctions alter nutrient recycling in tropical freshwaters.

    PubMed

    McIntyre, Peter B; Jones, Laura E; Flecker, Alexander S; Vanni, Michael J

    2007-03-13

    There is increasing evidence that species extinctions jeopardize the functioning of ecosystems. Overfishing and other human influences are reducing the diversity and abundance of fish worldwide, but the ecosystem-level consequences of these changes have not been assessed quantitatively. Recycling of nutrients is one important ecosystem process that is directly influenced by fish. Fish species vary widely in the rates at which they excrete nitrogen and phosphorus; thus, altering fish communities could affect nutrient recycling. Here, we use extensive field data on nutrient recycling rates and population sizes of fish species in a Neotropical river and Lake Tanganyika, Africa, to evaluate the effects of simulated extinctions on nutrient recycling. In both of these species-rich ecosystems, recycling was dominated by relatively few species, but contributions of individual species differed between nitrogen and phosphorus. Alternative extinction scenarios produced widely divergent patterns. Loss of the species targeted by fishermen led to faster declines in nutrient recycling than extinctions in order of rarity, body size, or trophic position. However, when surviving species were allowed to increase after extinctions, these compensatory responses had strong moderating effects even after losing many species. Our results underscore the complexity of predicting the consequences of extinctions from species-rich animal communities. Nevertheless, the importance of exploited species in nutrient recycling suggests that overfishing could have particularly detrimental effects on ecosystem functioning.

  6. Substrate and nutrient limitation regulating microbial growth in soil

    NASA Astrophysics Data System (ADS)

    Bååth, Erland

    2015-04-01

    Microbial activity and growth in soil is regulated by several abiotic factors, including temperature, moisture and pH as the most important ones. At the same time nutrient conditions and substrate availability will also determine microbial growth. Amount of substrate will not only affect overall microbial growth, but also affect the balance of fungal and bacterial growth. The type of substrate will also affect the latter. Furthermore, according to Liebig law of limiting factors, we would expect one nutrient to be the main limiting one for microbial growth in soil. When this nutrient is added, the initial second liming factor will become the main one, adding complexity to the microbial response after adding different substrates. I will initially describe different ways of determining limiting factors for bacterial growth in soil, especially a rapid method estimating bacterial growth, using the leucine incorporation technique, after adding C (as glucose), N (as ammonium nitrate) and P (as phosphate). Scenarios of different limitations will be covered, with the bacterial growth response compared with fungal growth and total activity (respiration). The "degree of limitation", as well as the main limiting nutrient, can be altered by adding substrate of different stoichiometric composition. However, the organism group responding after alleviating the nutrient limitation can differ depending on the type of substrate added. There will also be situations, where fungi and bacteria appear to be limited by different nutrients. Finally, I will describe interactions between abiotic factors and the response of the soil microbiota to alleviation of limiting factors.

  7. Nutrient and media recycling in heterotrophic microalgae cultures.

    PubMed

    Lowrey, Joshua; Armenta, Roberto E; Brooks, Marianne S

    2016-02-01

    In order for microalgae-based processes to reach commercial production for biofuels and high-value products such as omega-3 fatty acids, it is necessary that economic feasibility be demonstrated at the industrial scale. Therefore, process optimization is critical to ensure that the maximum yield can be achieved from the most efficient use of resources. This is particularly true for processes involving heterotrophic microalgae, which have not been studied as extensively as phototrophic microalgae. An area that has received significant conceptual praise, but little experimental validation, is that of nutrient recycling, where the waste materials from prior cultures and post-lipid extraction are reused for secondary fermentations. While the concept is very simple and could result in significant economic and environmental benefits, there are some underlying challenges that must be overcome before adoption of nutrient recycling is viable at commercial scale. Even more, adapting nutrient recycling for optimized heterotrophic cultures presents some added challenges that must be identified and addressed that have been largely unexplored to date. These challenges center on carbon and nitrogen recycling and the implications of using waste materials in conjunction with virgin nutrients for secondary cultures. The aim of this review is to provide a foundation for further understanding of nutrient recycling for microalgae cultivation. As such, we outline the current state of technology and practical challenges associated with nutrient recycling for heterotrophic microalgae on an industrial scale and give recommendations for future work.

  8. Application of controlled nutrient release to permeable reactive barriers.

    PubMed

    Freidman, Benjamin L; Gras, Sally L; Snape, Ian; Stevens, Geoff W; Mumford, Kathryn A

    2016-03-15

    The application of controlled release nutrient (CRN) materials to permeable reactive barriers to promote biodegradation of petroleum hydrocarbons in groundwater was investigated. The longevity of release, influence of flow velocity and petroleum hydrocarbon concentration on nutrient release was assessed using soluble and ion exchange CRN materials; namely Polyon™ and Zeopro™. Both CRN materials, assessed at 4 °C and 23 °C, demonstrated continuing release of nitrogen, phosphorus and potassium (N-P-K) at 3500 bed volumes passing, with longer timeframes of N-P-K release at 4 °C. Zeopro™-activated carbon mixtures demonstrated depletion of N-P-K prior to 3500 bed volumes passing. Increased flow velocity was shown to lower nutrient concentrations in Polyon™ flow cells while nutrient release from Zeopro™ was largely unchanged. The presence of petroleum hydrocarbons, at 1.08 mmol/L and 3.25 mmol/L toluene, were not shown to alter nutrient release from Polyon™ and Zeopro™ across 14 days. These findings suggest that Polyon™ and Zeopro™ may be suitable CRN materials for application to PRBs in low nutrient environments.

  9. Oxygen Consumption Rates of Bacteria under Nutrient-Limited Conditions

    PubMed Central

    Riedel, Timothy E.; Nealson, Kenneth H.; Finkel, Steven E.

    2013-01-01

    Many environments on Earth experience nutrient limitation and as a result have nongrowing or very slowly growing bacterial populations. To better understand bacterial respiration under environmentally relevant conditions, the effect of nutrient limitation on respiration rates of heterotrophic bacteria was measured. The oxygen consumption and population density of batch cultures of Escherichia coli K-12, Shewanella oneidensis MR-1, and Marinobacter aquaeolei VT8 were tracked for up to 200 days. The oxygen consumption per CFU (QO2) declined by more than 2 orders of magnitude for all three strains as they transitioned from nutrient-abundant log-phase growth to the nutrient-limited early stationary phase. The large reduction in QO2 from growth to stationary phase suggests that nutrient availability is an important factor in considering environmental respiration rates. Following the death phase, during the long-term stationary phase (LTSP), QO2 values of the surviving population increased with time and more cells were respiring than formed colonies. Within the respiring population, a subpopulation of highly respiring cells increased in abundance with time. Apparently, as cells enter LTSP, there is a viable but not culturable population whose bulk community and per cell respiration rates are dynamic. This result has a bearing on how minimal energy requirements are met, especially in nutrient-limited environments. The minimal QO2 rates support the extension of Kleiber's law to the mass of a bacterium (100-fg range). PMID:23770901

  10. Prevention and treatment of cancers by immune modulating nutrients.

    PubMed

    Janakiram, Naveena B; Mohammed, Altaf; Madka, Venkateshwar; Kumar, Gaurav; Rao, Chinthalapally V

    2016-06-01

    Epidemiological and laboratory data support the protective effects of bioactive nutrients in our diets for various diseases. Along with various factors, such as genetic history, alcohol, smoking, exercise, and dietary choices play a vital role in affecting an individual's immune responses toward a transforming cell, by either preventing or accelerating a neoplastic transformation. Ample evidence suggests that dietary nutrients control the inflammatory and protumorigenic responses in immune cells. Immunoprevention is usually associated with the modulation of immune responses that help in resolving the inflammation, thus improving clinical outcome. Various metabolic pathway-related nutrients, including glutamine, arginine, vitamins, minerals, and long-chain fatty acids, are important components of immunonutrient mixes. Epidemiological studies related to these substances have reported different results, with no or minimal effects. However, several studies suggest that these nutrients may have immune-modulating effects that may lower cancer risk. Preclinical studies submit that most of these components may provide beneficial effects. The present review discusses the available data, the immune-modulating functions of these nutrients, and how these substances could be used to study immune modulation in a neoplastic environment. Further research will help to determine whether the mechanistic signaling pathways in immune cells altered by nutrients can be exploited for cancer prevention and treatment. PMID:26833775

  11. Potato growth and yield using nutrient film technique (NFT)

    NASA Technical Reports Server (NTRS)

    Wheeler, R. M.; Mackowiak, C. L.; Sager, J. C.; Knott, W. M.; Hinkle, C. R.

    1990-01-01

    Potato plants, cvs Denali and Norland, were grown in polyvinyl chloride (PVC) trays using a continuous flowing nutrient film technique (NFT) to study tuber yield for NASA's Controlled Ecological Life Support Systems (CELSS) program. Nutrient solution pH was controlled automatically using 0.39M (2.5% (v/v) nitric acid (HNO3), while water and nutrients were replenished manually each day and twice each week, respectively. Plants were spaced either one or two per tray, allotting 0.2 or 0.4 m2 per plant. All plants were harvested after 112 days. Denali plants yielded 2850 and 2800 g tuber fresh weight from the one- and two-plant trays, respectively, while Norland plants yielded 1800 and 2400 g tuber fresh weight from the one- and two-plant trays. Many tubers of both cultivars showed injury to the periderm tissue, possibly caused by salt accumulation from the nutrient solution on the surface. Total system water usage throughout the study for all the plants equaled 709 liters (L), or approximately 2 L m-2 d-1. Total system acid usage throughout the study (for nutrient solution pH control) equaled 6.60 L, or 18.4 ml m-2 d-1 (7.2 mmol m-2 d-1). The results demonstrate that continuous flowing nutrient film technique can be used for tuber production with acceptable yields for the CELSS program.

  12. Fish extinctions alter nutrient recycling in tropical freshwaters

    PubMed Central

    McIntyre, Peter B.; Jones, Laura E.; Flecker, Alexander S.; Vanni, Michael J.

    2007-01-01

    There is increasing evidence that species extinctions jeopardize the functioning of ecosystems. Overfishing and other human influences are reducing the diversity and abundance of fish worldwide, but the ecosystem-level consequences of these changes have not been assessed quantitatively. Recycling of nutrients is one important ecosystem process that is directly influenced by fish. Fish species vary widely in the rates at which they excrete nitrogen and phosphorus; thus, altering fish communities could affect nutrient recycling. Here, we use extensive field data on nutrient recycling rates and population sizes of fish species in a Neotropical river and Lake Tanganyika, Africa, to evaluate the effects of simulated extinctions on nutrient recycling. In both of these species-rich ecosystems, recycling was dominated by relatively few species, but contributions of individual species differed between nitrogen and phosphorus. Alternative extinction scenarios produced widely divergent patterns. Loss of the species targeted by fishermen led to faster declines in nutrient recycling than extinctions in order of rarity, body size, or trophic position. However, when surviving species were allowed to increase after extinctions, these compensatory responses had strong moderating effects even after losing many species. Our results underscore the complexity of predicting the consequences of extinctions from species-rich animal communities. Nevertheless, the importance of exploited species in nutrient recycling suggests that overfishing could have particularly detrimental effects on ecosystem functioning. PMID:17360546

  13. Prevention and treatment of cancers by immune modulating nutrients.

    PubMed

    Janakiram, Naveena B; Mohammed, Altaf; Madka, Venkateshwar; Kumar, Gaurav; Rao, Chinthalapally V

    2016-06-01

    Epidemiological and laboratory data support the protective effects of bioactive nutrients in our diets for various diseases. Along with various factors, such as genetic history, alcohol, smoking, exercise, and dietary choices play a vital role in affecting an individual's immune responses toward a transforming cell, by either preventing or accelerating a neoplastic transformation. Ample evidence suggests that dietary nutrients control the inflammatory and protumorigenic responses in immune cells. Immunoprevention is usually associated with the modulation of immune responses that help in resolving the inflammation, thus improving clinical outcome. Various metabolic pathway-related nutrients, including glutamine, arginine, vitamins, minerals, and long-chain fatty acids, are important components of immunonutrient mixes. Epidemiological studies related to these substances have reported different results, with no or minimal effects. However, several studies suggest that these nutrients may have immune-modulating effects that may lower cancer risk. Preclinical studies submit that most of these components may provide beneficial effects. The present review discusses the available data, the immune-modulating functions of these nutrients, and how these substances could be used to study immune modulation in a neoplastic environment. Further research will help to determine whether the mechanistic signaling pathways in immune cells altered by nutrients can be exploited for cancer prevention and treatment.

  14. Quantifying the nutrient flux within a lowland karstic catchment

    NASA Astrophysics Data System (ADS)

    McCormack, T.; Naughton, O.; Johnston, P. M.; Gill, L. W.

    2015-10-01

    Nutrient contamination of surface and groundwaters is an issue of growing importance as the risks associated with agricultural runoff escalate due to increasing demands on global food production. In this study, the nutrient flux occurring within the surface and groundwaters of a lowland karst catchment in western Ireland was investigated with the aid of alkalinity sampling and a hydrological model. Water samples were tested from a variety of rivers, lakes (or turloughs), boreholes and springs at monthly intervals over three years. Alkalinity sampling was used to elucidate the contrasting hydrological functioning between different turloughs. Such disparate hydrological functioning was further investigated with the aid of a hydrological model which allowed for an estimate of allogenic and autogenic derived nutrient loading into the karst system. The model also allowed for an investigation of mixing within the turloughs, comparing observed behaviours with the hypothetical conservative behaviour allowed for by the model. Within the turloughs, nutrient concentrations were found to reduce over the flooded period, even though the turloughs hydrological functioning (and the hydrological model) suggested this should not occur. As such, it was determined that nutrient loss processes were occurring within the system. Denitrification during stable flooded periods (typically 3-4 months per year) was deemed to be the main process reducing nitrogen concentrations within the turloughs whereas phosphorus loss is thought to occur mostly via sedimentation and subsequent soil deposition. The results from this study suggest that, in stable conditions, ephemeral lakes can impart considerable nutrient losses on a karst groundwater system.

  15. PIKfyve Regulates Vacuole Maturation and Nutrient Recovery following Engulfment.

    PubMed

    Krishna, Shefali; Palm, Wilhelm; Lee, Yongchan; Yang, Wendy; Bandyopadhyay, Urmi; Xu, Haoxing; Florey, Oliver; Thompson, Craig B; Overholtzer, Michael

    2016-09-12

    The scavenging of extracellular macromolecules by engulfment can sustain cell growth in a nutrient-depleted environment. Engulfed macromolecules are contained within vacuoles that are targeted for lysosome fusion to initiate degradation and nutrient export. We have shown that vacuoles containing engulfed material undergo mTORC1-dependent fission that redistributes degraded cargo back into the endosomal network. Here we identify the lipid kinase PIKfyve as a regulator of an alternative pathway that distributes engulfed contents in support of intracellular macromolecular synthesis during macropinocytosis, entosis, and phagocytosis. We find that PIKfyve regulates vacuole size in part through its downstream effector, the cationic transporter TRPML1. Furthermore, PIKfyve promotes recovery of nutrients from vacuoles, suggesting a potential link between PIKfyve activity and lysosomal nutrient export. During nutrient depletion, PIKfyve activity protects Ras-mutant cells from starvation-induced cell death and supports their proliferation. These data identify PIKfyve as a critical regulator of vacuole maturation and nutrient recovery during engulfment. PMID:27623384

  16. [Compare the growth of Enteromorpha prolifera under different nutrient conditions].

    PubMed

    Pang, Qiu-ting; Li, Feng; Liu, Xiang-qing; Wang, Jiang-tao

    2013-09-01

    Enteromorpha prolifera (E. prolifera) tides have erupted frequently in the Yellow Sea and brought serious environmental problems to coastal sea since 2007. In order to research the influence of nutrients on E. prolifera growth, mesocosm experiments were carried out in the Yellow Sea in May 2012. There were 12 mesocosms, including 9 different experimental conditions. It shows that the uptake ability of nutrients and the growth of E. prolifera are strong. The growth rate of E. prolifera reaches 82% when the nutrient level is appropriate, while the rate could also keep around 10% even under low nutrient conditions. When phosphate level is appropriate, high dissolved inorganic nitrogen (DIN) concentration could promote the growth of E. prolifera. Sufficient and continuous nutrient supplement is the material basis for outbreak of E. prolifera green tide. Through analyzing the amount of nutrient uptake by E. prolifera, the production of organics by photosynthesis could be estimated, which has a strong linear relationship with the increased of wet weight of E. prolifera. PMID:24288982

  17. A global model of carbon-nutrient interactions

    NASA Technical Reports Server (NTRS)

    Moore, Berrien, III; Gildea, Patricia; Vorosmarty, Charles; Mellilo, Jerry M.; Peterson, Bruce J.

    1985-01-01

    The global biogeochemical model presented has two primary objectives. First, it characterizes natural elemental cycles and their linkages for the four elements significant to Earth's biota: C, N, S, and P. Second, it describes changes in these cycles due to human activity. Global nutrient cycles were studied within the drainage basins of several major world rivers on each continent. The initial study region was the Mississippi drainage basin, concentrating on carbon and nitrogen. The model first establishes the nutrient budgets of the undisturbed ecosystems in a study region. It then uses a data set of land use histories for that region to document the changes in these budgets due to land uses. Nutrient movement was followed over time (1800 to 1980) for 30 ecosystems and 10 land use categories. A geographically referenced ecological information system (GREIS) was developed to manage the digital global data bases of 0.5 x 0.5 grid cells needed to run the model: potential vegetation, drainage basins, precipitation, runoff, contemporary land cover, and FAO soil maps of the world. The results show the contributions of land use categories to river nutrient loads on a continental scale; shifts in nutrient cycling patterns from closed, steady state systems to mobile transient or open, steady state systems; soil organic matter depletion patterns in U.S. agricultural lands; changing nutrient ratios due to land use changes; and the effect of using heavy fertilizer on aquatic systems.

  18. Differences in egg nutrient availability, development, and nutrient metabolism of broiler and layer embryos.

    PubMed

    Nangsuay, A; Molenaar, R; Meijerhof, R; van den Anker, I; Heetkamp, M J W; Kemp, B; van den Brand, H

    2015-03-01

    Selection for production traits of broilers and layers leads to physiological differences, which may already be present during incubation. This study aimed to investigate the influence of strain (broiler vs layer) on egg nutrient availability, embryonic development and nutrient metabolism. A total of 480 eggs with an egg weight range of 62.0 to 64.0 g from Lohmann Brown Lite and Ross 308 breeder flocks of 41 or 42 weeks of age were selected in two batches of 120 eggs per batch per strain. For each batch, 30 eggs per strain were used to determine egg composition, including nutrient and energy content, and 90 eggs per strain were separately incubated in one of two climate respiration chambers at an eggshell temperature of 37.8°C. The results showed that broiler eggs had a higher ratio of yolk: albumen with 2.41 g more yolk and 1.48 g less albumen than layers. The yolk energy content of broiler eggs was 46.32 kJ higher than that of layer eggs, whereas total energy content of broiler eggs was 47.85 kJ higher compared to layer eggs. Yolk-free body mass at incubation day 16 and chick weight and length at hatch were higher in broilers compared to layers. Respiration quotient of broiler embryos was higher than layer embryos during incubation day 8 to incubation day 10. A 0.24 g lower residual yolk at the hatch of broiler embryos than for the layer embryos indicated that broiler embryos used more yolk and had a higher energy utilization and energy deposition in yolk-free body mass. Heat production of broiler embryos was higher than that of layer embryos from incubation day 12 to incubation day 18, but efficiency of converting egg energy used by embryos to form yolk-free body mass was similar. In conclusion, broiler and layer embryos have different embryonic development patterns, which affect energy utilization and embryonic heat production. However, the embryos are equal in efficiency of converting the energy used to yolk-free body mass.

  19. Implications of premature needle abscission to the elemental nutrient status and nutrient retranslocation patterns of ozone injured Jeffrey pine

    SciTech Connect

    Patterson, M.T.; Rundel, P.W. )

    1993-06-01

    The foliar nutrient relations of ozone stressed Jeffrey pine growing in the southern Sierra Nevada of California was compared in trees retaining different numbers of needle cohorts. A 20% reduction in foliar nitrogen occurred in the oldest needles of both sensitive trees (retaining two years of needles) and resistant trees (retaining five years of needles) which coincided with the flush of new needles in late June. Nitrogen content of recently expanded needles on sensitive trees was 15% lower than needles of similar age on resistant trees immediately after becoming fully expanded, but was not significantly different two months after expansion. Resistant trees retranslocated higher fractions of all phloem-mobile nutrients measured (N, K, P and Mg) although the differences were small (between 3 and 9%). The smaller foliar pool of nutrients resulting from premature abscission may result in ozone sensitive trees relying more heavily on soil supplies for both short and long term nutrient requirements.

  20. Soil nutrient competition in earth system models: an important but underappreciated driver of plant responses to nutrient fertilization

    NASA Astrophysics Data System (ADS)

    Zhu, Q.; Riley, W. J.; Tang, J.; Koven, C.

    2015-12-01

    Earth System Models (ESMs) used to project future biosphere-climate feedbacks rely on predictions of terrestrial carbon dynamics. Furthermore, soil nutrient availability strongly modulates land surface carbon dynamics, including plant sequestration of atmospheric CO2. Plant growth under future environmental changes (e.g., nitrogen and phosphorus deposition) depends on how well plants compete with microbial and abiotic competitors. Here, we surveyed recent developments of nutrient competition representations in ESMs that participated in the CMIP5 project. We found that nutrient competition is over-simplified despite its ecological significance. Existing ESMs either assume that soil-decomposing microbes (1) outcompete plants or (2) are evenly competitive, both of which are inconsistent with theoretical understanding and field observations. We compiled and synthesized global data of forest carbon productivity in response to nitrogen and phosphorus fertilization experiments. Using this synthesis, we show that existing ESMs with the first and second competition schemes lead to underestimation and overestimation, respectively, of fertilization effects on plant growth. We reduced these systematic biases by applying a new competition scheme in CLM4.5 and the essentially equivalent ACME land model (ALMv0) based on the Equilibrium Chemistry Approximation, which is based on classical equilibrium chemical kinetics theory. This approach dynamically updates nutrient competitiveness among multiple consumers (e.g., plants, decomposing microbes, nitrifier, denitrifier, mineral surfaces) as a function of soil nutrient status. There has been a long-term debate regarding how to implement theoretically realistic and computationally efficient nutrient competition schemes in ESMs. Our approach reconciles the complex nature of ecosystem nutrient competition with a computationally tractable approach applicable to ESMs. More importantly, our results imply that previous estimates of plant

  1. Hydromorphological control of nutrient cycling in complex river floodplain systems

    NASA Astrophysics Data System (ADS)

    Hein, T.; Bondar-Kunze, E.; Felkl, M.; Habersack, H.; Mair, M.; Pinay, G.; Tritthart, M.; Welti, N.

    2009-04-01

    Riparian zones and floodplains are key components within river ecosystems controlling nutrient cycling by promoting transformation processes and thus, act as biogeochemical hot spots. The intensity of these processes depends on the exchange conditions (the connectivity) with the main channel and the morphological setting of the water bodies. At the landscape scale, three interrelated principles of hydromorphological dynamics can be formulated regarding the cycling and transfer of carbon and nutrients in large rivers ecosystems: a) The mode of carbon and nutrient delivery affects ecosystem functioning; b) Increasing residence time and contact area impact nutrient transformation; c) Floods and droughts are natural events that strongly influence pathways of carbon and nutrient cycling. These three principles of hydromorphological dynamics control the nutrient uptake and retention and are linked over different temporal and spatial scales. All three factors can be strongly affected by natural disturbances or anthropogenic impacts, through a change in either the water regime or the geomorphologic setting of the river valley. Any change in natural water regimes will affect the biogeochemistry of riparian zones and floodplains as well as their ability to cycle and mitigate nutrient fluxes originating from upstream and/or upslope. Especially these areas have been altered by river regulation and land use changes over the last 200 years leading to the deterioration of the functioning of these compartments within the riverine landscape. The resulting deficits have prompted rehabilitation and restoration measures aiming to increase the spatial heterogeneity, the complexity, of these ecosystems. Yet, a more integrated approach is needed considering the present status of nutrient dynamics and the effects of restoration measures at different scales. The present paper analyses the effects of river side-arm restoration on ecosystem functions within the side-arm and highlights

  2. Light, nutrients, and herbivore growth in oligotrophic streams

    SciTech Connect

    Hill, Walter R; Smith, John G; Stewart, Arthur J

    2010-02-01

    The light : nutrient hypothesis posits that herbivore growth is increasingly constrained by low food quality as the ratio of light to nutrients increases in aquatic ecosystems. We tested predictions of this hypothesis by examining the effects of large seasonal cycles in light and nutrients on the mineral content of periphyton and the growth rate of a dominant herbivore (the snail Elimia clavaeformis) in two oligotrophic streams. Streambed irradiances in White Oak Creek and Walker Branch (eastern Tennessee, USA) varied dramatically on a seasonal basis due to leaf phenology in the surrounding deciduous forests and seasonal changes in sun angle. Concentrations of dissolved nutrients varied inversely with light, causing light : nitrate and light : phosphate to range almost 100-fold over the course of any individual year. Periphyton nitrogen and phosphorus concentrations were much lower than the concentrations of these elements in snails, and they bottomed out in early spring when streambed irradiances were highest. Snail growth, however, peaked in early spring when light:nutrient ratios were highest and periphyton nutrient concentrations were lowest, Growth was linearly related to primary production (accounting for up to 85% of growth variance in individual years), which in turn was driven by seasonal variation in light. Conceptual models of herbivore growth indicate that growth should initially increase as increasing light levels stimulate primary production, but then level off, and then decrease as the negative effects of decreasing algal nutrient content override the positive effects of increased food production. Our results showed no evidence of an inflection point where increasing ratios of light to nutrients negatively affected growth. Snail growth in these intensively grazed streams is probably unaffected by periphyton nutrient content because exploitative competition for food reduces growth rates to levels where the demand for nitrogen and phosphorus is small

  3. Light, nutrients, and herbivore growth in oligotrophic streams.

    PubMed

    Hill, Walter R; Smith, John G; Stewart, Arthur J

    2010-02-01

    The light : nutrient hypothesis posits that herbivore growth is increasingly constrained by low food quality as the ratio of light to nutrients increases in aquatic ecosystems. We tested predictions of this hypothesis by examining the effects of large seasonal cycles in light and nutrients on the mineral content of periphyton and the growth rate of a dominant herbivore (the snail Elimia clavaeformis) in two oligotrophic streams. Streambed irradiances in White Oak Creek and Walker Branch (eastern Tennessee, USA) varied dramatically on a seasonal basis due to leaf phenology in the surrounding deciduous forests and seasonal changes in sun angle. Concentrations of dissolved nutrients varied inversely with light, causing light : nitrate and light : phosphate to range almost 100-fold over the course of any individual year. Periphyton nitrogen and phosphorus concentrations were much lower than the concentrations of these elements in snails, and they bottomed out in early spring when streambed irradiances were highest. Snail growth, however, peaked in early spring when light:nutrient ratios were highest and periphyton nutrient concentrations were lowest, Growth was linearly related to primary production (accounting for up to 85% of growth variance in individual years), which in turn was driven by seasonal variation in light. Conceptual models of herbivore growth indicate that growth should initially increase as increasing light levels stimulate primary production, but then level off, and then decrease as the negative effects of decreasing algal nutrient content override the positive effects of increased food production. Our results showed no evidence of an inflection point where increasing ratios of light to nutrients negatively affected growth. Snail growth in these intensively grazed streams is probably unaffected by periphyton nutrient content because exploitative competition for food reduces growth rates to levels where the demand for nitrogen and phosphorus is small

  4. Intra-annual nutrient flux in Pinus taeda.

    PubMed

    Albaugh, Timothy J; Allen, H Lee; Stape, Jose L; Fox, Thomas R; Rubilar, Rafael A; Price, James W

    2012-10-01

    Intra-annual nutrient (nitrogen, phosphorus, potassium, calcium and magnesium) flux was quantified for Pinus taeda L. at a nutrient-poor, well-drained sandy site in Scotland County, NC, USA where a 2 × 2 factorial of irrigation and nutrition was applied in four replications in a 10-year-old stand with 1200 stems ha(-1). Treatments were applied with the goal of providing optimum nutrition (no nutritional deficiencies) and water availability. Component (foliage, branch, stem and root) nutrient content was estimated monthly for 2 years using nutrient concentration and phenology assessments combined with destructive harvests. Positive flux values indicated nutrient accumulation in the trees while negative values indicated nutrient loss from the trees. Fertilization significantly increased nitrogen, phosphorus, potassium, calcium and magnesium flux 140%, on average, over non-fertilized. Irrigation significantly increased calcium flux 28% while there was no significant irrigation effect on nitrogen, phosphorus, potassium or magnesium. Maximum nutrient fluxes (kg ha(-1) day(-1)) for non-fertilized and fertilized stands were 0.36 and 1.05 for nitrogen, 0.042 and 0.095 for phosphorus, 0.13 and 0.51 for potassium, 0.27 and 0.42 for calcium, and 0.04 and 0.12 for magnesium, respectively. Maximum flux was coincident with ephemeral tissue (foliage and fine root) development and likely would be higher in stands with more foliage than those observed in this study (projected leaf area indices were 1.5 and 3.0 for the non-fertilized and fertilized stands). Minimum nutrient fluxes (kg ha(-1) day(-1)) for non-fertilized and fertilized stands were -0.18 and -0.42 for nitrogen, -0.029 and -0.070 for phosphorus, -0.05 and -0.18 for potassium, -0.04 and -0.05 for calcium, and -0.02 and -0.03 for magnesium, respectively. Minimum fluxes were typically observed in the dormant season and were linked to foliage senescence and branch death. Foliage and branch component nutrient contents

  5. Nutrient allocation among plant organs across 13 tree species in three Bornean rain forests with contrasting nutrient availabilities.

    PubMed

    Aoyagi, Ryota; Kitayama, Kanehiro

    2016-07-01

    Allocation of nitrogen (N) and phosphorus (P) among plant organs is an important factor regulating growth rate, which is a key ecological process associated with plant life-history strategies. However, few studies have explored how N and P investment in photosynthetic (leaves) and non-photosynthetic (stems and roots) organs changes in relation to depletion of each element. We investigated nutrient concentrations of plant organs in relation to whole-plant nutrient concentration (total nutrient weight per total biomass) as an index of nutrient status of each individual using the saplings of the 13 species in three tropical rain forests with contrasting N and P availabilities (tropical evergreen forests and tropical heath forests). We found a steeper decrease in foliar N concentration than foliar P concentration with decreasing whole-plant nutrient concentration. Moreover, the steeper decrease in foliar N concentration was associated with relatively stable N concentration in stems, and vice versa for P. We suggest that the depletion of N is associated with a rapid dilution of foliar N because the cell walls in non-photosynthetic organs function as an N sink. On the other hand, these species can maintain foliar P concentration by decreasing stem P concentrations despites the depletion of P. Our results emphasize the significance of non-photosynthetic organs as an N sink for understanding the variation of foliar nutrient concentrations for the tree species in the three Bornean rain forests with different N and P availabilities.

  6. Increased Nutrient Sensitivity and Plasma Concentrations of Enteral Hormones during Duodenal Nutrient Infusion in Functional Dyspepsia

    PubMed Central

    Bharucha, Adil E.; Camilleri, Michael; Burton, Duane D.; Thieke, Shannon L.; Feuerhak, Kelly J.; Basu, Ananda; Zinsmeister, Alan R.

    2015-01-01

    Objectives Functional dyspepsia is predominantly attributed to gastric sensorimotor dysfunctions. The contribution of intestinal chemosensitivity to symptoms is not understood. We evaluated symptoms and plasma hormones during enteral nutrient infusion and the association with impaired glucose tolerance and quality-of-life (QOL) scores in functional dyspepsia vs health. Design Enteral hormonal responses and symptoms were measured during isocaloric and isovolumic dextrose and lipid infusions into the duodenum in 30 patients with functional dyspepsia (n=27) or nausea and vomiting (n=3) and 35 healthy controls. Infusions were administered in randomized order over 120 minutes each, with a 120-minute washout. Cholecystokinin, glucose-dependent insulinotropic peptide, glucagonlike peptide 1 (GLP1), and peptide YY were measured during infusions. Results Moderate or more severe symptoms during lipid (4 controls vs 14 patients) and dextrose (1 control vs 12 patients) infusions were more prevalent in patients than controls (P≤.01), associated with higher dyspepsia symptom score (P=.01), worse QOL (P=.01), and greater plasma hormone concentrations (eg, GLP1 during lipid infusion). Moderate or more severe symptoms during enteral infusion explained 18%, and depression score explained 21%, of interpatient variation in QOL. Eight patients had impaired glucose tolerance, associated with greater plasma GLP1 and peptide YY concentrations during dextrose and lipid infusions, respectively. Conclusions Increased sensitivity to enteral dextrose and lipid infusions was associated with greater plasma enteral hormone concentrations, more severe daily symptoms, and worse QOL in functional dyspepsia. These observations are consistent with the hypothesis that enteral hormones mediate increased intestinal sensitivity to nutrients in functional dyspepsia. PMID:25403365

  7. [Analysis of algal blooms in Da-Ning River of Three Gorges Reservoir].

    PubMed

    Zheng, Bing-Hui; Cao, Cheng-Jin; Zhang, Jia-Lei; Huang, Min-Sheng; Chen, Zhen-Lou

    2009-11-01

    According to the survey conducted from Apr. to Jun. 2007 and from Apr. to May. 2008, the changes of water quality, forms and distributions of nutrient salts and characters of algal blooms in Da-ning River of Three Gorges Reservoir (TGR) were studied. The results indicated that the concentrations of nitrogen and phosphorus nutrient were abundant during sensitive period of algal blooms in Da-ning River. Total nitrogen (TN) and total phosphorus (TP) values are 0.84-3.21 mg/L and 0.011-0.531 mg/L respectively, and the nutrients concentrations become high gradually from upstream to downstream. Total dissolved nitrogen (TDN) is the major form of TN accounting for 84%, and total dissolved phosphorus (TDP) is dominant (TDP/TP = 60%). Algal blooms bring phosphorus nutrient bio-concentration. The rates of TN and TP are all in excess of 16, which show eutrophication is limited by phosphorus. Potassium permanganate index and dissolved oxygen (DO) are at low levels and change stably. But chlorophyll a (Chl-a) becomes frequently, the value is 1.41-219.04 mg x m(-3). Significant positive correlations are all observed by correlation analysis between Chl-a and the main parameters (r(Chla-TP) = 0.453, r(Chla-potassium permanganate index) = 0.641, r(Chla-DO) = 0.584, r(Chla-pH) = 0.409, p < 0.01), but significant negative correlations are observed between Chl-a and Secchi depth (SD) (r(Chla-SD) = - 0.392, p < 0.01). The pH is fluctuated by multiparameter esp. in algal blooms. Widespread algae are observed by microscope during sensitive period of algal blooms in Da-ning River accounting for 8 phylum 82 genus 124 species, which Bacillariophyta and Chlorophyta are dominant, and then Cyanophyta and Pyrrophyta. Three whole watershed algal blooms break out in Da-ning River during the period, and the highest values of algal density are 14-1 427 times as many as the normal values. The dominant species of algal blooms are mostly involved with O. borgei, C. microporum, Chlorococcum humicola, P

  8. Biomarkers for nutrient intake with focus on alternative sampling techniques.

    PubMed

    Holen, T; Norheim, F; Gundersen, T E; Mitry, P; Linseisen, J; Iversen, P O; Drevon, C A

    2016-01-01

    Biomarkers of nutrient intake or nutrient status are important objective measures of foods/nutrients as one of the most important environmental factors people are exposed to. It is very difficult to obtain accurate data on individual food intake, and there is a large variation of nutrient composition of foods consumed in a population. Thus, it is difficult to obtain precise measures of exposure to different nutrients and thereby be able to understand the relationship between diet, health, and disease. This is the background for investing considerable resources in studying biomarkers of nutrients believed to be important in our foods. Modern technology with high sensitivity and specificity concerning many nutrient biomarkers has allowed an interesting development with analyses of very small amounts of blood or tissue material. In combination with non-professional collection of blood by finger-pricking and collection on filters or sticks, this may make collection of samples and analyses of biomarkers much more available for scientists as well as health professionals and even lay people in particular in relation to the marked trend of self-monitoring of body functions linked to mobile phone technology. Assuming standard operating procedures are used for collection, drying, transport, extraction, and analysis of samples, it turns out that many analytes of nutritional interest can be measured like metabolites, drugs, lipids, vitamins, minerals, and many types of peptides and proteins. The advantage of this alternative sampling technology is that non-professionals can collect, dry, and mail the samples; the samples can often be stored under room temperature in a dry atmosphere, requiring small amounts of blood. Another promising area is the potential relation between the microbiome and biomarkers that may be measured in feces as well as in blood.

  9. Distributions of inorganic nutrients in the bohai sea of china

    NASA Astrophysics Data System (ADS)

    Zhengyan, Li; Jie, Bai; Jinhui, Shi; Huiwang, Gao

    2003-04-01

    To study the contents and distribution of inorganic nutrients in the Bohai Sea of China, two cruise surveys were undertaken in August (summer) 2000 and January (winter) 2001, respectively. A total of 595 water samples were collected from 91 stations and five nutrients, i.e., nitrate, nitrite, ammonia, phosphate and silicate, were analyzed for each sample. The results show that the average concentration of dissolved inorganic nitrogen (DIN) in the Bohai Sea in winter (6.529 μmol L-1) is significantly higher than that in summer (3.717 μmol L-1). The phosphorus concentration in winter (0.660 μmol L-1) is also significantly higher than that in summer (0.329 μmol L-1). Mean silicate concentration in winter (7.858 μmol L-1) is, however, not significantly different from that in summer (7.200 μmol L-1). Nutrients also vary considerably in different areas in Bohai Sea. DIN concentration in the Laizhou Bay (4.444 μmol L-1), for example, is significantly higher than those in the Bohai Bay (2.270 μmol L-1) and Bohai Strait (2.431 μmol L-1), which is caused by the discharge of large amounts of nitrogen into Laizhou Bay via Yellow River. The nutrients show different vertical distribution patterns. In summer, nutrients in bottom layer are generally richer than those in surface and middle layers. In winter, however, nutrients are not significantly different in different layers. Compared with historic data, DIN contents have increased continually since the early 1980 s. Based on atomic ratios of different nutrients, nitrogen is still the limiting factor for algal growth in the Bohai Sea.

  10. Soil nutrient assessment for urban ecosystems in Hubei, China.

    PubMed

    Li, Zhi-Guo; Zhang, Guo-Shi; Liu, Yi; Wan, Kai-Yuan; Zhang, Run-Hua; Chen, Fang

    2013-01-01

    Recent urban landscape vegetation surveys conducted in many cities in China identified numerous plant nutrient deficiencies, especially in newly developed cities. Soil nutrients and soil nutrient management in the cities of Hubei province have not received adequate attention to date. The aims of this study were to characterize the available nutrients of urban soils from nine cities in Hubei province, China, and to assess how soil nutrient status is related to land use type and topography. Soil nutrients were measured in 405 sites from 1,215 soil samples collected from four land use types (park, institutional [including government building grounds, municipal party grounds, university grounds, and garden city institutes], residential, and roadside verges) and three topographies (mountainous [142-425 m a.s.l], hilly [66-112 m a.s.l], and plain [26-30 m a.s.l]). Chemical analyses showed that urban soils in Hubei had high pH and lower soil organic matter, available nitrogen (N), available phosphorus (P), and available boron (B) concentrations than natural soils. Nutrient concentrations were significantly different among land use types, with the roadside and residential areas having greater concentrations of calcium (Ca), sulfur (S), copper (Cu), manganese (Mn), and zinc (Zn) that were not deficient against the recommended ranges. Topographic comparisons showed statistically significant effects for 8 of the 11 chemical variables (p < 0.05). Concentrations of N, Ca, Mg, S, Cu, and Mn in plain cities were greater than those in mountainous cities and show a negative correlation with city elevation. These results provide data on urban soils characteristics in land use types and topography, and deliver significant information for city planners and policy makers. PMID:24086647

  11. Biomarkers for nutrient intake with focus on alternative sampling techniques.

    PubMed

    Holen, T; Norheim, F; Gundersen, T E; Mitry, P; Linseisen, J; Iversen, P O; Drevon, C A

    2016-01-01

    Biomarkers of nutrient intake or nutrient status are important objective measures of foods/nutrients as one of the most important environmental factors people are exposed to. It is very difficult to obtain accurate data on individual food intake, and there is a large variation of nutrient composition of foods consumed in a population. Thus, it is difficult to obtain precise measures of exposure to different nutrients and thereby be able to understand the relationship between diet, health, and disease. This is the background for investing considerable resources in studying biomarkers of nutrients believed to be important in our foods. Modern technology with high sensitivity and specificity concerning many nutrient biomarkers has allowed an interesting development with analyses of very small amounts of blood or tissue material. In combination with non-professional collection of blood by finger-pricking and collection on filters or sticks, this may make collection of samples and analyses of biomarkers much more available for scientists as well as health professionals and even lay people in particular in relation to the marked trend of self-monitoring of body functions linked to mobile phone technology. Assuming standard operating procedures are used for collection, drying, transport, extraction, and analysis of samples, it turns out that many analytes of nutritional interest can be measured like metabolites, drugs, lipids, vitamins, minerals, and many types of peptides and proteins. The advantage of this alternative sampling technology is that non-professionals can collect, dry, and mail the samples; the samples can often be stored under room temperature in a dry atmosphere, requiring small amounts of blood. Another promising area is the potential relation between the microbiome and biomarkers that may be measured in feces as well as in blood. PMID:27551313

  12. Reducing future nutrient inputs to the Black Sea.

    PubMed

    Strokal, Maryna Petrivna; Kroeze, Carolien; Kopilevych, Volodymyr Abramovych; Voytenko, Larysa Vladyslavivna

    2014-01-01

    Rivers export increasing amounts of dissolved inorganic (DIN, DIP) and organic (DON, DOP) nitrogen and phosphorus to the Black Sea causing coastal eutrophication. The aim of this study is to explore future trends in river export of these nutrients to the sea through a sensitivity analysis. We used the Global NEWS (Nutrient Export from WaterSheds) model to this end. We calculated that between 2000 and 2050 nutrient inputs to the Black Sea may increase or decrease, depending on the assumed environmental management. We analyzed the effects of agricultural and sewage management on nutrient inputs to the sea in 2050 relative to two Millennium Ecosystem Assessment (MEA) scenarios, Global Orchestration (GO) and Adaptive Mosaic (AM). In these baselines, total N and P inputs to the Black Sea decrease between 2000 and 2050, but not for all rivers and nutrient forms. Our results indicate that it is possible to reduce nutrient inputs to the sea further between 2000 and 2050 in particular for dissolved inorganic N and P and for many river basins, but not for all. For scenarios assuming combined agricultural and sewage management dissolved inorganic N and P inputs to the Black Sea are reduced by up to two-thirds between 2000 and 2050 and dissolved organic N and P inputs by one-third. River export of DIN is mainly affected by agricultural management and that of DIP by sewage management. On the other hand, in scenarios assuming increased fertilizer use for, for instance bioenergy crops, nutrient inputs to the sea increase. An increase in DIP inputs by southern rivers seems difficult to avoid because of the increasing number of people connected to sewage systems. PMID:23906857

  13. Deciphering the Interconnections between Nutrient Supply, Demand, and Limitation

    NASA Astrophysics Data System (ADS)

    Covino, T. P.; Heffernan, J. B.; Bernhardt, E. S.

    2015-12-01

    Studies of stream nutrient dynamics have often focused on the influence of a single potentially limiting nutrient; however, it has become increasingly evident that ecosystems are constrained by the supply of numerous limiting resources. These resources may vary seasonally as a function of temperature, sunlight, and input of carbon and nutrients from upstream or terrestrial sources. We used multiple approaches, including plateau and TASCC nutrient additions, as well as analysis of diel nitrate dynamics as three different and complementary measures of nutrient demand/limitation in New Hope Creek, a third order stream in the Duke Forest of North Carolina over the course of one year. Nitrate-N concentrations were relatively high during the winter, spring, and summer months ranging from 105 - 518 and averaging 383 µg/L between January - August. During this time frame there was low demand for and limited uptake of added nitrate during plateau or TASCC additions (i.e., addition of N did not stimulate increased N uptake) although there was processing of background N evident from diel N and oxygen analyses. During autumn litterfall ecosystem respiration increased strongly and nitrate-N concentrations dropped precipitously, ranging from 9 - 34 and averaging 23 µg/L between September - December. During this period of low in-stream nitrate-N, demand for and uptake of added nitrate was high with maximum uptake rates of 560 µg/m2/min. This highlights the importance of understanding the relationship between nutrient supply and demand and the need to determine multiple resource controls over system processing. We also suggest that nutrient addition experiments need to be interpreted within the context of the supply and demand of multiple potentially limiting resources and the that the temporal dynamics of these relationships should be considered.

  14. Sleep Symptoms Associated with Intake of Specific Dietary Nutrients

    PubMed Central

    Grandner, Michael A.; Jackson, Nicholas; Gerstner, Jason R.; Knutson, Kristen L.

    2013-01-01

    Sleep symptoms are associated with weight gain and cardiometabolic disease. The potential role of diet has been largely unexplored. Data from the 2007–2008 NHANES were used (N=4,552) to determine which nutrients were associated with sleep symptoms in a nationally-representative sample. Survey items assessed difficulty falling asleep, sleep maintenance difficulties, non-restorative sleep, and daytime sleepiness. Analyses were adjusted for energy intake, other dietary factors, exercise, BMI and sociodemographics. Population-weighted, logistic regression, with backwards-stepwise selection, examined which nutrients were associated with sleep symptoms. Odds ratios (ORs) reflect the difference in odds of sleep symptoms associated with a doubling in nutrient. Nutrients that were independently associated with difficulty falling asleep included (in order): Alpha-Carotene (OR=0.96), Selenium (OR=0.80), Dodecanoic Acid (OR=0.91), Calcium (OR=0.83), and Hexadecanoic Acid (OR=1.10). Nutrients that were independently associated with sleep maintenance difficulties included: Salt (OR=1.19), Butanoic Acid (0,81), Carbohydrate (OR=0.71), Dodecanoic Acid (OR=0.90), Vitamin D (OR=0.84),, Lycopene (OR=0.98), Hexanoic Acid (OR= 1.25), and Moisture (OR=1.27). Nutrients that were independently associated with non-restorative sleep included Butanoic Acid (OR=1.09), Calcium (OR=0.81), Vitamin C (OR=0.92), Water (OR=0.98), Moisture (OR= 1.41), and Cholesterol (OR= 1.10). Nutrients that were independently associated with sleepiness included: Moisture (OR=1.20), Theobromine (OR=1.04), Potassium (OR= 0.70), Water (OR=0.97). These results suggest novel associations between sleep symptoms and diet/metabolism, potentially explaining associations between sleep and cardiometabolic diseases. PMID:23992533

  15. Sources of Errors in Developing Monthly to Seasonal Nutrient Forecasts

    NASA Astrophysics Data System (ADS)

    Libera, D.; Arumugam, S.

    2014-12-01

    Excess nitrogen in a river system can cause an overabundance of aquatic plant growth that can cause negative effects on larger water bodies downstream. This can result in eutrophication resulting in large algae blooms that hurt local recreation and fish populations. Recent studies have focused on developing seasonal nutrient forecasts that can be used to control nonpoint reduction strategies. Given that the seasonal nutrients are developed using large-scale climate forecasts, it needs to be pre-processed for ingesting into a water quality model. By considering the LOADEST model, a USGS constituent load estimator, and the Soil &Water Assessment Tool (SWAT) this study quantifies the sources of errors in developing monthly to seasonal nutrient forecasts using climate information. For this purpose, we consider the observed streamflow and nutrient loadings at the Tar River at Tarboro, NC station for developing and testing the water quality models. This streamgage was chosen since it is part of the Hydro-Climatic Data Network (HCDN) which naturally considers basins that are relatively undeveloped with limited storage and pumping. The study also proposes two bias-correction procedures, a bivariate copula-based model and a canonical correlation model, for preserving the cross-correlation structure between the observed nutrients and streamflows. Climate forecasts from the ECHAM4.5 model and NOAA NCEP Climate Forecast System (CFS) will be downscaled and disaggregated for developing nutrient forecasts from the SWAT model and the LOADEST model. Using both the canonical correlation model and the bi-variate copula based bias-correction procedures, the forecasted streamflow and TN loadings will be bias-corrected to preserve the correlation structure. The study will also quantify and compare different sources of errors that propagate in developing monthly to seasonal nutrient forecasts using climate information.

  16. Soil Nutrient Assessment for Urban Ecosystems in Hubei, China

    PubMed Central

    Li, Zhi-guo; Zhang, Guo-shi; Liu, Yi; Wan, Kai-yuan; Zhang, Run-hua; Chen, Fang

    2013-01-01

    Recent urban landscape vegetation surveys conducted in many cities in China identified numerous plant nutrient deficiencies, especially in newly developed cities. Soil nutrients and soil nutrient management in the cities of Hubei province have not received adequate attention to date. The aims of this study were to characterize the available nutrients of urban soils from nine cities in Hubei province, China, and to assess how soil nutrient status is related to land use type and topography. Soil nutrients were measured in 405 sites from 1,215 soil samples collected from four land use types (park, institutional [including government building grounds, municipal party grounds, university grounds, and garden city institutes], residential, and roadside verges) and three topographies (mountainous [142–425 m a.s.l], hilly [66–112 m a.s.l], and plain [26–30 m a.s.l]). Chemical analyses showed that urban soils in Hubei had high pH and lower soil organic matter, available nitrogen (N), available phosphorus (P), and available boron (B) concentrations than natural soils. Nutrient concentrations were significantly different among land use types, with the roadside and residential areas having greater concentrations of calcium (Ca), sulfur (S), copper (Cu), manganese (Mn), and zinc (Zn) that were not deficient against the recommended ranges. Topographic comparisons showed statistically significant effects for 8 of the 11 chemical variables (p < 0.05). Concentrations of N, Ca, Mg, S, Cu, and Mn in plain cities were greater than those in mountainous cities and show a negative correlation with city elevation. These results provide data on urban soils characteristics in land use types and topography, and deliver significant information for city planners and policy makers. PMID:24086647

  17. Nutrient trends through time in Sweden's Baltic Drainage Area

    NASA Astrophysics Data System (ADS)

    Fischer, I.; Destouni, G.; Prieto, C.

    2015-12-01

    Changes in climate and land-use have and will continue to modify regional hydrology, in turn impacting environmental health, agricultural productivity and water resource quality and availability. The Baltic region is an area of interest as the coast spans nine countries- serving over 100 million people. The Baltic Sea contains one of the largest human caused hypoxic dead zones due to eutrophication driven by anthropogenic excess loading of nutrients. Policies to reduce these loads include also international directives and agreements, such as the EU Water Framework Directive, adopted in 2000 to protect and improve water quality throughout the European Union, and the Baltic Sea Action Plan under the Helsinki Commission aimed specifically at reducing the nutrient loading to and mitigating the eutrophication of the Baltic Sea. In light of these policies and amidst the number of studies on the Baltic Sea we ask, using the accessible nutrient and discharge data what does nutrient loading look like today? Are the most excessive loads going down? Observed nutrient and flow time series across Sweden allow for answering these questions, by spatial and temporal trend analysis of loads from various parts of Sweden to the Baltic Sea. Analyzing these observed time series in conjunction with the ecological health status classifications of the EU Water Framework Directive, allows in particular for answering the question if the loads into the water bodies with the poorest water quality, and from those to the Baltic Sea, are improving, being maintained or deteriorating. Such insight is required to contribute to relevant and efficient water and nutrient load management. Furthermore, empirically calculating nutrient loads, rather than only modeling, reveals that the water body health classification may not reflect what water bodies actually contribute the heaviest loads to the Baltic Sea. This work also underscores the importance of comprehensive analysis of all available data from

  18. Influence of 120 kDa Pyruvate:Ferredoxin Oxidoreductase on Pathogenicity of Trichomonas vaginalis

    PubMed Central

    Song, Hyun-Ouk

    2016-01-01

    Trichomonas vaginalis is a flagellate protozoan parasite and commonly infected the lower genital tract in women and men. Iron is a known nutrient for growth of various pathogens, and also reported to be involved in establishment of trichomoniasis. However, the exact mechanism was not clarified. In this study, the author investigated whether the 120 kDa protein of T. vaginalis may be involved in pathogenicity of trichomonads. Antibodies against 120 kDa protein of T. vaginalis, which was identified as pyruvate:ferredoxin oxidoreductase (PFOR) by peptide analysis of MALDI-TOF-MS, were prepared in rabbits. Pretreatment of T. vaginalis with anti-120 kDa Ab decreased the proliferation and adherence to vaginal epithelial cells (MS74) of T. vaginalis. Subcutaneous tissue abscess in anti-120 kDa Ab-treated T. vaginalis-injected mice was smaller in size than that of untreated T. vaginalis-infected mice. Collectively, the 120 kDa protein expressed by iron may be involved in proliferation, adhesion to host cells, and abscess formation, thereby may influence on the pathogenicity of T. vaginalis. PMID:26951982

  19. Influence of 120 kDa Pyruvate:Ferredoxin Oxidoreductase on Pathogenicity of Trichomonas vaginalis.

    PubMed

    Song, Hyun-Ouk

    2016-02-01

    Trichomonas vaginalis is a flagellate protozoan parasite and commonly infected the lower genital tract in women and men. Iron is a known nutrient for growth of various pathogens, and also reported to be involved in establishment of trichomoniasis. However, the exact mechanism was not clarified. In this study, the author investigated whether the 120 kDa protein of T. vaginalis may be involved in pathogenicity of trichomonads. Antibodies against 120 kDa protein of T. vaginalis, which was identified as pyruvate:ferredoxin oxidoreductase (PFOR) by peptide analysis of MALDI-TOF-MS, were prepared in rabbits. Pretreatment of T. vaginalis with anti-120 kDa Ab decreased the proliferation and adherence to vaginal epithelial cells (MS74) of T. vaginalis. Subcutaneous tissue abscess in anti-120 kDa Ab-treated T. vaginalis-injected mice was smaller in size than that of untreated T. vaginalis-infected mice. Collectively, the 120 kDa protein expressed by iron may be involved in proliferation, adhesion to host cells, and abscess formation, thereby may influence on the pathogenicity of T. vaginalis. PMID:26951982

  20. Nutrient dynamics in Amazon shelf waters: results from AMASSEDS

    NASA Astrophysics Data System (ADS)

    Demaster, David J.; Pope, Robert H.

    1996-03-01

    Four hydrographic cruises were conducted on the Amazon shelf as part of the AMASSEDS field program. During each cruise, approximately 55 stations were occupied and nutrients, as well as other hydrographic parameters, were measured. The results of this time series sampling program indicate that the nutrient concentrations in the riverine end-member (silicate = 144 μmol kg -1, phosphate = 0.7 μmol kg -1, nitrate = 16 μmol kg -1, ammonium = 0.4 μmol kg -1, and urea = 0.9 μmol kg -1) remain relatively constant, despite a two-fold seasonal variation in river water discharge rate. Of the major nutrients (nitrate, phosphate, ammonium and silicate), nitrate shows the greatest seasonal change in riverine end-member concentration with a high value (23 μmol kg -1) during the March cruise (rising river discharge) and a low value (12 μmol kg -1) during the November cruise (falling river discharge). Nitrate is the dominant nutrient form of inorganic nitrogen throughout most of the river/ocean mixing zone, however, in the outershelf area, where nitrate has been depleted by biological production, this nutrient occurs at concentrations comparable to the other nitrogen species (ammonium, nitrite and urea), which are at levels < 1 μmol kg -1. Nearshore, high turbidity inhibits phytoplankton production because of light limitation, whereas on the outershelf, nitrate appears to be limiting growth more than silicate or phosphate. Nutrient uptake was observed during all four cruises, however, nearly all of this production must be regenerated in shelf bottom waters, because very little of the biogenic materials are buried in the seabed (silicate burial <4% of flux to algal blooms; ˜10% burial of biologically available inorganic nitrogen reaching the river/ocean mixing zone; and <3% burial of phosphate flux to shelf environment). Clearly the Amazon shelf is not an efficient nutrient trap. Initial estimates of primary production on the Amazon shelf suggest that algal blooms are

  1. Nutrient Overland Flow and Nitrous Oxide Losses from Residential Landscapes

    NASA Astrophysics Data System (ADS)

    Osmond, D.; Spence, P.; Heitman, J.; Robarge, W. P.; Walker, J. T.; water quality, nitrogen emissions, residential landscapes

    2011-12-01

    Residential lawn maintenance practices (mowing, fertilizer, irrigation, reseeding, and aeration) result in aesthetically appealing landscapes, but is capable of causing nutrient losses via overland flow or gaseous losses to the atmosphere (e.g. nitrous oxide - N2O). The overall study objective was to determine the effect of lawn maintenance on nutrient losses from residential landscapes. The specific objectives were: modify a passive sampling system to determine nutrient loads due to overland flow from lawns; evaluate differences in overland flow frequency, volumes, and nutrient losses during rainfall events (≥ 25.4 mm); and compare N2O losses following rainfall events. Three distinct lawn schemes were studied: a high maintenance fescue (Festuca arundinacea) lawn (HMFL), a low maintenance fescue lawn (LMFL), and a mixed forested residential landscape (FRL). The modified passive sampling system allowed 100% recovery of overland flow and demonstrated that differences in maintenance influenced the overland flow frequency, volumes, and nutrient losses. The LMFL had the greatest overland flow volumes and nutrient unit area loads; although N and P concentrations in overland flow exceeded USEPA recommendations from all three lawns. Nutrient losses (g ha-1 yr-1) from all three residential landscapes were 1000 times less than fertilizer (kg ha-1 yr-1) and throughfall (kg ha-1 yr-1) inputs, partially due to the presence of well-structured soils (low bulk densities and high infiltration rates). Irrigation practices between the HMFL and LMFL explained the differences in overland flow volumes and nutrient loads, especially during the first half of the study when drought conditions existed at the study site (Cary, North Carolina). The lack of irrigation in the LMFL resulted in early dormancy and a minimal thatch layer and lower plant density, which caused higher volumes of overland flow. Trends in the N2O losses from the HMFL and LMFL were associated with timing of fertilizer

  2. Algal remediation of CO₂ and nutrient discharges: A review.

    PubMed

    Judd, Simon; van den Broeke, Leo J P; Shurair, Mohamed; Kuti, Yussuf; Znad, Hussein

    2015-12-15

    The recent literature pertaining to the application of algal photobioreactors (PBRs) to both carbon dioxide mitigation and nutrient abatement is reviewed and the reported data analysed. The review appraises the influence of key system parameters on performance with reference to (a) the absorption and biological fixation of CO2 from gaseous effluent streams, and (b) the removal of nutrients from wastewaters. Key parameters appraised individually with reference to CO2 removal comprise algal speciation, light intensity, mass transfer, gas and hydraulic residence time, pollutant (CO2 and nutrient) loading, biochemical and chemical stoichiometry (including pH), and temperature. Nutrient removal has been assessed with reference to hydraulic residence time and reactor configuration, along with C:nutrient ratios and other factors affecting carbon fixation, and outcomes compared with those reported for classical biological nutrient removal (BNR). Outcomes of the review indicate there has been a disproportionate increase in algal PBR research outputs over the past 5-8 years, with a significant number of studies based on small, bench-scale systems. The quantitative impacts of light intensity and loading on CO2 uptake are highly dependent on the algal species, and also affected by solution chemical conditions such as temperature and pH. Calculations based on available data for biomass growth rates indicate that a reactor CO2 residence time of around 4 h is required for significant CO2 removal. Nutrient removal data indicate residence times of 2-5 days are required for significant nutrient removal, compared with <12 h for a BNR plant. Moreover, the shallow depth of the simplest PBR configuration (the high rate algal pond, HRAP) means that its footprint is at least two orders of magnitude greater than a classical BNR plant. It is concluded that the combined carbon capture/nutrient removal process relies on optimisation of a number of process parameters acting synergistically

  3. Climate Variability Impacts on Watershed Nutrient Delivery and Reservoir Production

    NASA Astrophysics Data System (ADS)

    White, J. D.; Prochnow, S. J.; Zygo, L. M.; Byars, B. W.

    2005-05-01

    Reservoirs in agricultural dominated watersheds tend to exhibit pulse-system behavior especially if located in climates dominated by summer convective precipitation inputs. Concentration and bulk mass of nutrient and sediment inputs into reservoir systems vary in terms of timing and magnitude of delivery from watershed sources to reservoirs under these climate conditions. Reservoir management often focuses on long-term average inputs without considering short and long-term impacts of variation in loading. In this study we modeled a watershed-reservoir system to assess how climate variability affects reservoir primary production through shifts in external loading and internal recycling of limiting nutrients. The Bosque watershed encompasses 423,824 ha in central Texas which delivers water to Lake Waco, a 2900 ha reservoir that is the primary water source for the city of Waco and surrounding areas. Utilizing the Soil Water Assessment Tool for the watershed and river simulations and the CE-Qual-2e model for the reservoir, hydrologic and nutrient dynamics were simulated for a 10 year period encompassing two ENSO cycles. The models were calibrated based on point measurement of water quality attributes for a two year time period. Results indicated that watershed delivery of nutrients was affected by the presence and density of small flood-control structure in the watershed. However, considerable nitrogen and phosphorus loadings were derived from soils in the upper watershed which have had long-term waste-application from concentrated animal feeding operations. During El Niño years, nutrient and sediment loads increased by 3 times above non-El Niño years. The simulated response within the reservoir to these nutrient and sediment loads had both direct and indirect. Productivity evaluated from chlorophyll a and algal biomass increased under El Niño conditions, however species composition shifts were found with an increase in cyanobacteria dominance. In non-El Niño years

  4. Assessment of nutrient retention by Natete wetland Kampala, Uganda

    NASA Astrophysics Data System (ADS)

    Kanyiginya, V.; Kansiime, F.; Kimwaga, R.; Mashauri, D. A.

    Natete wetland which is located in a suburb of Kampala city in Uganda is dominated by C yperus papyrus and covers an area of approximately 1 km 2. The wetland receives wastewater and runoff from Natete town which do not have a wastewater treatment facility. The main objective of this study was to assess nutrient retention of Natete wetland and specifically to: determine the wastewater flow patterns in the wetland; estimate the nutrient loads into and out of the wetland; determine the nutrient retention by soil, plants and water column in the wetland; and assess the above and belowground biomass density of the dominant vegetation. Soil, water and plant samples were taken at 50 m intervals along two transects cut through the wetland; soil and water samples were taken at 10 cm just below the surface. Physico-chemical parameters namely pH, electrical conductivity and temperature were measured in situ. Water samples were analyzed in the laboratory for ammonium-nitrogen, nitrate-nitrogen, total nitrogen, orthophosphate and total phosphorus. Electrical conductivity ranged between 113 μS/cm and 530 μS/cm and the wastewater flow was concentrated on the eastern side of the wetland. pH varied between 6 and 7, temperature ranged from 19 °C to 24 °C. NH 4-N, NO 3-N, and TN concentrations were retained by 21%, 98%, and 35% respectively. Phosphorus concentration was higher at the outlet of the wetland possibly due to release from sediments and leaching. Nutrient loads were higher at the inlet (12,614 ± 394 kgN/day and 778 ± 159 kgP/day) than the outlet (2368 ± 425 kgN/day and 216 ± 56 kgP/day) indicating retention by the wetland. Plants stored most nutrients compared to soil and water. The belowground biomass of papyrus vegetation in the wetland was higher (1288.4 ± 8.3 gDW/m 2) than the aboveground biomass (1019.7 ± 13.8 gDW/m 2). Plant uptake is one of the important routes of nutrient retention in Natete wetland. It is recommended that harvesting papyrus can be an

  5. Critical source times for nutrient loss in agricultural catchment streams

    NASA Astrophysics Data System (ADS)

    Melland, Alice; Shore, Mairead; Mellander, Per-Erik; McDonald, Noeleen; Shortle, Ger; Murphy, Paul; Jordan, Phil

    2014-05-01

    Identifying periods of the year when there is a high risk of incidental nutrient loss from farms via runoff to streams underpins current nutrient management legislation in Europe. This research explored high-temporal resolution nutrient transfer patterns relative to the time that manure and fertiliser are prohibited from being spread (the mandatory spreading 'closed' period) in five Irish agricultural catchments. Catchment nutrient losses during the 12 week closed periods in 2009-10, 2010-11 and 2011-12 were compared with losses during the remainder of the year, and with losses in the two week 'shoulder' periods immediately before and after the closed period. The closed period losses were assumed to be residual from soil nutrient stores and the 'shoulder' periods were considered to also include incidental losses. Nutrient loss was measured at sub-hourly frequency as total phosphorus (P) and total oxidised nitrogen (mostly nitrate-N) fluxes in streamflow. The streamflow fluxes showed that the proportion of the annual nitrate-N loss occurring during the closed periods (33-61%) was high compared with the remainder of the year. Six to ten times more nitrate-N loss occurred in the two weeks after, compared with the two weeks before, the closed period. These two week 'shoulder' period losses were, on average, less than or equal to 2.5 kg nitrate-N/ha and 9% of total annual nitrate-N loss in streamflow. On average, 40-53% of the annual P loss occurred during the closed periods but in a runoff-prone catchment in a year with a wet summer, the closed period was the less risky period. Similar to nitrate-N, two to twenty times more P loss occurred in the two weeks after, compared with the two weeks before, the closed period. These shoulder period losses were, on average, less than or equal to 0.027 kg/ha and 4.2% of total annual P loss in streamflow. The proportion of the shoulder period loss that could be attributed to recently spread nutrients was not known but can be

  6. A COMPARATIVE ANALYSIS OF NUTRIENT LOADING, NUTRIENT RETENTION AND NET ECOSYSTEM METABOLISM IN THREE TIDAL RIVER ESTUARIES DIFFERING PREDOMINATELY BY THEIR WATERSHED LAND USE TYPES.

    EPA Science Inventory

    Abstract and oral presentation for the Estuarine Research Federation Conference.

    Estuarine retention of watershed nutrient loads, system-wide nutrient biogeochemical fluxes, and net ecosystem metabolism (NEM) were determined in three estuaries exhibiting differing magnitud...

  7. [Nutrients in atmospheric wet deposition in the East China Sea].

    PubMed

    Zhu, Yu-Mei; Liu, Su-Mei

    2011-09-01

    92 rainwater samples were collected at Shengsi Archipelago from January 2008 to December 2009. The pH and the concentrations of nutrients (NH4(+), NO3(-) + NO2(-), PO4(3-), SiO3(2-)) were analyzed using spectrophotometry to understand the impacts of the atmospheric wet deposition on the ecosystem of the East China Sea. The results showed that the pH of 85% samples were less than 5.0, and had significant effect on the environment. There were significant differences among monthly average concentrations of nutrients and rainfall and seasonal average wet deposition of nutrients in investigation periods. The annual average wet deposition flux was 52.05 mmol x (m2 x a) (-1) for DIN, 0.08 mmol x (m2 x a) (-1) for PO4(3-), 2.05 mmol x (m2 x a) (-1) for SiO3(2-). The average molar ratios of NO3(-)/NH4(+) is 0.73, N: P ratio is 684: 1, indicating that nutrients composition in rainwater was different from seawater of the East China Sea Shelf (10-150). The wet deposition may change the nutrients structure, pH and lead to change the phytoplankton production in the surface seawater of the East China Sea, even lead to the red tide. PMID:22165245

  8. Effects of Salinity and Nutrient Addition on Mangrove Excoecaria agallocha

    PubMed Central

    Chen, Yaping; Ye, Yong

    2014-01-01

    Effects of salinity on seed germination and growth of young (1 month old) and old (2-year old) seedlings of Excoecaria agallocha were investigated. Combined effects of salinity and nutrient level were also examined on old seedlings. Seed germination was best at 0 and 5 psu salinity. 15 psu salinity significantly delayed root initiation and decreased final establishment rate. All seeds failed to establish at 25 psu salinity. Young seedlings performed best at 0 and 5 psu, but growth was stunned at 15 psu, and all seedlings died within 90 days at 25 psu. Old seedlings grew best at salinities below 5 psu and they survived the whole cultivation at 25 psu. This indicated that E. agallocha increased salt tolerance over time. Gas exchange was significantly compromised by salinities above 15 psu but evidently promoted by high nutrient. Proline accumulated considerably at high nutrient, and its contents increased from 0 to 15 psu but decreased at 25 psu salinity. Lipid peroxidation was aggravated by increasing salinity beyond 15 psu but markedly alleviated by nutrient addition. These responses indicated that E. agallocha was intolerant to high salinity but it can be greatly enhanced by nutrient addition. PMID:24691495

  9. Modelling macrofaunal biomass in relation to hypoxia and nutrient loading

    NASA Astrophysics Data System (ADS)

    Timmermann, Karen; Norkko, Joanna; Janas, Urszula; Norkko, Alf; Gustafsson, Bo G.; Bonsdorff, Erik

    2012-12-01

    Nutrient loading of aquatic ecosystems results in more food for benthic macrofaunal communities but also increases the risk of hypoxia, resulting in a reduction or complete loss of benthic biomass. This study investigates the interaction between eutrophication, hypoxia and benthic biomass with emphasis on the balance between gains and loss of benthic biomass due to changes in nutrient loadings. A physiological fauna model with 5 functional groups was linked to a 3D coupled hydrodynamic-ecological Baltic Sea model. Model results revealed that benthic biomass increased between 0 and 700% after re-oxygenating bottom waters. Nutrient reduction scenarios indicated improved oxygen concentrations in bottom waters and decreased sedimentation of organic matter up to 40% after a nutrient load reduction following the Baltic Sea Action Plan. The lower food supply to benthos reduced the macrofaunal biomass up to 35% especially in areas not currently affected by hypoxia, whereas benthic biomass increased up to 200% in areas affected by eutrophication-induced hypoxia. The expected changes in benthic biomass resulting from nutrient load reductions and subsequent reduced hypoxia may not only increase the food supply for benthivorous fish, but also significantly affect the biogeochemical functioning of the ecosystem.

  10. Pathogen infection drives patterns of nutrient resorption in citrus plants

    PubMed Central

    Cao, Jirong; Cheng, Chunzhen; Yang, Junjie; Wang, Qibing

    2015-01-01

    Nutrient resorption processes in the plants infected by pathogen remain poorly understood. Huanglongbing (HLB) is a destructive disease of citrus. HLB-pathogen ‘Candidatus Liberibacter asiaticus’ grows specifically in the phloem of hosts and may cause problems in the plant vascular system after infection. Therefore, it brings a great concern about the phloem nutrient transport and nutrient intra-cycling in HLB-affected plants. We investigated the effects of ‘Ca. L. asiaticus’ infection on nitrogen (N) and phosphorus (P) concentrations and resorption in different citrus species (i.e. Citrus reticulata, Citrus limon and Citrus maxima). HLB-pathogen infection had distinctive impacts on nutrient resorption in different species. P resorption efficiency substantially decreased in infected C. reticulata plants relative to the healthy plants in summer, which may account for the marked decrease in the average fruit yield. P resorption was more efficient in infected C. limon plants than in the healthy plants. However, for C. maxima plants, HLB had no significant effects on N:P ratio in live leaves and resorption efficiency as well as on fruit yield. Keeping efficient internal nutrient cycling can be a strategy of citrus species being tolerant to HLB. PMID:26419510

  11. Solution culture method for studying nutrient uptake and stress

    SciTech Connect

    Kay, L.E.; Gutschick, V.P.

    1984-01-01

    In order to study the uptake of two (or more) different mineral nutrients at very low concentrations, a solution culture system with new capabilities was developed. It allows tight control of nutrient concentrations of very low levels, accurate uptake rate measurements, and frequent non-destructive measurements of plant mass and dimensions. The hydroponic system includes (1) a water-deionizing system, (2) an automated mixing system that can provide up to 3000 liters/day of the base solution containing the non-varied nutrients; (3) seven separate reciprocating syringe pumps, each of which mixes base solution and concentrates of the two varied nutrients and supplies an entire set of plants for one nutritional treatment; (4) growth pots, consisting of 2-liter plastic beakers divided internally into three separate compartments, each provided with a separate nutrient inflow, drain, and aerator/mixer. This once-through (non-recirculating) flow system is constructed entirely of plastics and lesser amounts of other materials in order to minimize chemical contamination. Numerous other advantages are discussed. 3 references, 1 table.

  12. Understanding nutrient build-up on urban road surfaces.

    PubMed

    Miguntanna, Nandika Prasadani; Goonetilleke, Ashantha; Egodowatta, Prasanna; Kokot, Serge

    2010-01-01

    This article discusses the outcomes of a research project on nutrients build-up on urban road surfaces. Nutrient build-up was investigated on road sites belonging to residential, industrial and commercial land use. Collected build-up samples were separated into five particle size ranges and were tested for total nitrogen (TN), total phosphorus (TP) and sub species of nutrients, namely, NO2-, NO3-, TKN and PO4(3-). Multivariate analytical techniques were used to analyse the data and to develop detailed understanding on buildup. Data analysis revealed that the solids loads on urban road surfaces are highly influenced by factors such as land use, antecedent dry period and traffic volume. However, the nutrient build-up process was found to be independent of the type of land use. It was solely dependent on the particle size of solids build-up. Most of the nutrients were associated with the particle size range < 150 microm. Therefore, the removal of particles below 150 microm from road surfaces is of importance for the removal of nitrogen and phosphorus from road surface solids build-up. It is also important to consider the difference in the composition of nitrogen and phosphorus build-up in the context of designing effective stormwater quality mitigation strategies.

  13. [Nutrients in atmospheric wet deposition in the East China Sea].

    PubMed

    Zhu, Yu-Mei; Liu, Su-Mei

    2011-09-01

    92 rainwater samples were collected at Shengsi Archipelago from January 2008 to December 2009. The pH and the concentrations of nutrients (NH4(+), NO3(-) + NO2(-), PO4(3-), SiO3(2-)) were analyzed using spectrophotometry to understand the impacts of the atmospheric wet deposition on the ecosystem of the East China Sea. The results showed that the pH of 85% samples were less than 5.0, and had significant effect on the environment. There were significant differences among monthly average concentrations of nutrients and rainfall and seasonal average wet deposition of nutrients in investigation periods. The annual average wet deposition flux was 52.05 mmol x (m2 x a) (-1) for DIN, 0.08 mmol x (m2 x a) (-1) for PO4(3-), 2.05 mmol x (m2 x a) (-1) for SiO3(2-). The average molar ratios of NO3(-)/NH4(+) is 0.73, N: P ratio is 684: 1, indicating that nutrients composition in rainwater was different from seawater of the East China Sea Shelf (10-150). The wet deposition may change the nutrients structure, pH and lead to change the phytoplankton production in the surface seawater of the East China Sea, even lead to the red tide.

  14. Groundwater - The Disregarded Component in Lake Water and Nutrient Budgets

    NASA Astrophysics Data System (ADS)

    Lewandowski, J.; Meinikmann, K.; Pöschke, F.; Nuetzmann, G.; Rosenberry, D. O.

    2015-12-01

    Lake eutrophication is a large and still growing problem in many parts of the world, commonly due to anthropogenic sources of nutrients such as fertilizer, manure or sewage. Improved quantification of nutrient inputs is required to address this problem. Lacustrine groundwater discharge (LGD) transports nutrients from catchments to lakes. Unfortunately, LGD has often been disregarded in lake nutrient studies due to many different reasons, although first reports of LGD are more than 40 years old. Most measurement techniques are based on separate determinations of seepage volume and nutrient concentration of exfiltrating groundwater; i.e., by multiplying both values. We review the international literature, give a brief overview of measurement techniques, and present typical volumes, concentrations and loads reported in literature. Furthermore, we describe the fate of nitrogen and phosphorus on their subsurface pathway from the catchment through the reactive aquifer-lake interface into the lake, and compare LGD related processes with those of two other groundwater-surface water interfaces: the hyporheic zone in streams and the interface between aquifer and marine systems where SGD (submarine groundwater discharge) occurs.

  15. Pathogen infection drives patterns of nutrient resorption in citrus plants.

    PubMed

    Cao, Jirong; Cheng, Chunzhen; Yang, Junjie; Wang, Qibing

    2015-01-01

    Nutrient resorption processes in the plants infected by pathogen remain poorly understood. Huanglongbing (HLB) is a destructive disease of citrus. HLB-pathogen 'Candidatus Liberibacter asiaticus' grows specifically in the phloem of hosts and may cause problems in the plant vascular system after infection. Therefore, it brings a great concern about the phloem nutrient transport and nutrient intra-cycling in HLB-affected plants. We investigated the effects of 'Ca. L. asiaticus' infection on nitrogen (N) and phosphorus (P) concentrations and resorption in different citrus species (i.e. Citrus reticulata, Citrus limon and Citrus maxima). HLB-pathogen infection had distinctive impacts on nutrient resorption in different species. P resorption efficiency substantially decreased in infected C. reticulata plants relative to the healthy plants in summer, which may account for the marked decrease in the average fruit yield. P resorption was more efficient in infected C. limon plants than in the healthy plants. However, for C. maxima plants, HLB had no significant effects on N:P ratio in live leaves and resorption efficiency as well as on fruit yield. Keeping efficient internal nutrient cycling can be a strategy of citrus species being tolerant to HLB. PMID:26419510

  16. The imprint of crop choice on global nutrient needs

    NASA Astrophysics Data System (ADS)

    Jobbágy, Esteban G.; Sala, Osvaldo E.

    2014-08-01

    Solutions to meet growing food requirements in a world of limited suitable land and degrading environment focus mainly on increasing crop yields, particularly in poorly performing regions, and reducing animal product consumption. Increasing yields could alleviate land requirements, but imposing higher soil nutrient withdrawals and in most cases larger fertilizer inputs. Lowering animal product consumption favors a more efficient use of land as well as soil and fertilizer nutrients; yet actual saving may largely depend on which crops and how much fertilizer are used to feed livestock versus people. We show, with a global analysis, how the choice of cultivated plant species used to feed people and livestock influences global food production as well as soil nutrient withdrawals and fertilizer additions. The 3 to 15-fold differences in soil nutrient withdrawals per unit of energy or protein produced that we report across major crops explain how composition shifts over the last 20 years have reduced N, maintained P and increased K harvest withdrawals from soils while contributing to increasing dietary energy, protein and, particularly, vegetable fat outputs. Being highly variable across crops, global fertilization rates do not relate to actual soil nutrient withdrawals, but to monetary values of harvested products. Future changes in crop composition could contribute to achieve more sustainable food systems, optimizing land and fertilizer use.

  17. Effects of salinity and nutrient addition on mangrove Excoecaria agallocha.

    PubMed

    Chen, Yaping; Ye, Yong

    2014-01-01

    Effects of salinity on seed germination and growth of young (1 month old) and old (2-year old) seedlings of Excoecaria agallocha were investigated. Combined effects of salinity and nutrient level were also examined on old seedlings. Seed germination was best at 0 and 5 psu salinity. 15 psu salinity significantly delayed root initiation and decreased final establishment rate. All seeds failed to establish at 25 psu salinity. Young seedlings performed best at 0 and 5 psu, but growth was stunned at 15 psu, and all seedlings died within 90 days at 25 psu. Old seedlings grew best at salinities below 5 psu and they survived the whole cultivation at 25 psu. This indicated that E. agallocha increased salt tolerance over time. Gas exchange was significantly compromised by salinities above 15 psu but evidently promoted by high nutrient. Proline accumulated considerably at high nutrient, and its contents increased from 0 to 15 psu but decreased at 25 psu salinity. Lipid peroxidation was aggravated by increasing salinity beyond 15 psu but markedly alleviated by nutrient addition. These responses indicated that E. agallocha was intolerant to high salinity but it can be greatly enhanced by nutrient addition.

  18. Nutrient depletion in Bacillus subtilis biofilms triggers matrix production

    NASA Astrophysics Data System (ADS)

    Zhang, Wenbo; Seminara, Agnese; Suaris, Melanie; Brenner, Michael P.; Weitz, David A.; Angelini, Thomas E.

    2014-01-01

    Many types of bacteria form colonies that grow into physically robust and strongly adhesive aggregates known as biofilms. A distinguishing characteristic of bacterial biofilms is an extracellular polymeric substance (EPS) matrix that encases the cells and provides physical integrity to the colony. The EPS matrix consists of a large amount of polysaccharide, as well as protein filaments, DNA and degraded cellular materials. The genetic pathways that control the transformation of a colony into a biofilm have been widely studied, and yield a spatiotemporal heterogeneity in EPS production. Spatial gradients in metabolites parallel this heterogeneity in EPS, but nutrient concentration as an underlying physiological initiator of EPS production has not been explored. Here, we study the role of nutrient depletion in EPS production in Bacillus subtilis biofilms. By monitoring simultaneously biofilm size and matrix production, we find that EPS production increases at a critical colony thickness that depends on the initial amount of carbon sources in the medium. Through studies of individual cells in liquid culture we find that EPS production can be triggered at the single-cell level by reducing nutrient concentration. To connect the single-cell assays with conditions in the biofilm, we calculate carbon concentration with a model for the reaction and diffusion of nutrients in the biofilm. This model predicts the relationship between the initial concentration of carbon and the thickness of the colony at the point of internal nutrient deprivation.

  19. Nutrient fluxes from coastal California catchments with suburban development

    NASA Astrophysics Data System (ADS)

    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.

  20. Parallel Exploitation of Diverse Host Nutrients Enhances Salmonella Virulence

    PubMed Central

    Steeb, Benjamin; Claudi, Beatrice; Burton, Neil A.; Tienz, Petra; Schmidt, Alexander; Farhan, Hesso; Mazé, Alain; Bumann, Dirk

    2013-01-01

    Pathogen access to host nutrients in infected tissues is fundamental for pathogen growth and virulence, disease progression, and infection control. However, our understanding of this crucial process is still rather limited because of experimental and conceptual challenges. Here, we used proteomics, microbial genetics, competitive infections, and computational approaches to obtain a comprehensive overview of Salmonella nutrition and growth in a mouse typhoid fever model. The data revealed that Salmonella accessed an unexpectedly diverse set of at least 31 different host nutrients in infected tissues but the individual nutrients were available in only scarce amounts. Salmonella adapted to this situation by expressing versatile catabolic pathways to simultaneously exploit multiple host nutrients. A genome-scale computational model of Salmonella in vivo metabolism based on these data was fully consistent with independent large-scale experimental data on Salmonella enzyme quantities, and correctly predicted 92% of 738 reported experimental mutant virulence phenotypes, suggesting that our analysis provided a comprehensive overview of host nutrient supply, Salmonella metabolism, and Salmonella growth during infection. Comparison of metabolic networks of other pathogens suggested that complex host/pathogen nutritional interfaces are a common feature underlying many infectious diseases. PMID:23633950

  1. Nutrient addition to enhance biological treatment of greywater.

    PubMed

    Jefferson, B; Burgess, J E; Pichon, A; Harkness, J; Judd, S J

    2001-08-01

    This study compares the chemical oxygen demand (COD) removal and respiration rates of a microbial population treating real and synthetic greywaters dosed with nutrient supplements. The nutrient composition of the real and synthetic greywaters was analysed and the dosing regime for nitrogen, phosphorus and a range of trace metals planned accordingly. The doses consisted of eight single additives (macronutrients and trace metals) to the control greywater and six trace metal additions to C: N : P balanced greywater. The COD removal for the control real and synthetic greywater in lab-scale activated sludge systems (0.038 and 0.286 kg COD kg MLSS(-1) d(-1), respectively) confirmed nutrient limitation and the poor degree of greywater treatment. Nutrient dosing increased the COD removal rate and oxygen uptake rate in many cases. The greatest stimulation of microbial activity was observed with zinc additions to C: N: P balanced real greywater (1.291 kg COD kg MLSS(-1) d(-1) over 30 times the control). Inhibitory effects to various extents were rare and limited mainly to the additions of metals to synthetic greywater. The dominance of chemicals effects was observed on addition of some micronutrients; notably iron and aluminium, metals on which many coagulants for use in biotreatment of other wastewaters are based. The data indicate that the impact of understanding microbial processes and the nutrients required for wastewater treatment can only serve to optimise process efficiency for the proposed treatment of greywater.

  2. Pathogen infection drives patterns of nutrient resorption in citrus plants.

    PubMed

    Cao, Jirong; Cheng, Chunzhen; Yang, Junjie; Wang, Qibing

    2015-09-30

    Nutrient resorption processes in the plants infected by pathogen remain poorly understood. Huanglongbing (HLB) is a destructive disease of citrus. HLB-pathogen 'Candidatus Liberibacter asiaticus' grows specifically in the phloem of hosts and may cause problems in the plant vascular system after infection. Therefore, it brings a great concern about the phloem nutrient transport and nutrient intra-cycling in HLB-affected plants. We investigated the effects of 'Ca. L. asiaticus' infection on nitrogen (N) and phosphorus (P) concentrations and resorption in different citrus species (i.e. Citrus reticulata, Citrus limon and Citrus maxima). HLB-pathogen infection had distinctive impacts on nutrient resorption in different species. P resorption efficiency substantially decreased in infected C. reticulata plants relative to the healthy plants in summer, which may account for the marked decrease in the average fruit yield. P resorption was more efficient in infected C. limon plants than in the healthy plants. However, for C. maxima plants, HLB had no significant effects on N:P ratio in live leaves and resorption efficiency as well as on fruit yield. Keeping efficient internal nutrient cycling can be a strategy of citrus species being tolerant to HLB.

  3. Quantifying the nutrient flux within a lowland karstic catchment

    NASA Astrophysics Data System (ADS)

    McCormack, T.; Naughton, O.; Johnston, P. M.; Gill, L. W.

    2015-01-01

    Nutrient contamination of surface and groundwaters is an issue of growing importance as the risks associated with agricultural runoff escalate due to increasing demands on global food production. In this study, the nutrient flux occurring within the surface and groundwaters of a lowland karst catchment in western Ireland was investigated with the aid of alkalinity sampling and a hydrological model. Water samples were collected and tested from a variety of rivers, lakes (or turloughs), boreholes and springs at monthly intervals over a three year period. Alkalinity sampling was used to elucidate the contrasting hydrological functioning between different turloughs. Such disparate hydrological functioning was further investigated with the aid of a hydrological model which allowed for an estimate of allogenic and autogenic derived nutrient loading into the karst system. The model also allowed for an investigation of mixing within the turloughs, comparing observed behaviours with the hypothetical conservative behaviour allowed for by the model. Results indicated that at the system outlet to the sea, autogenic recharge had added approximately 35% to the total flow and approximately 85% to the total N-load. Within some turloughs, nutrient loads were found to reduce over the flooded period, even though the turloughs hydrological functioning (and the hydrological model) suggested this should not occur. As such, it was determined that nutrient loss processes were occurring within the system. Denitrification was deemed to be the main process reducing nitrogen concentrations within the turloughs whereas phosphorus loss is thought to occur mostly within the diffuse/epikarst zone.

  4. Nutrient mobility within river basins: a European perspective

    NASA Astrophysics Data System (ADS)

    Neal, Colin; Heathwaite, A. L.

    2005-03-01

    The research presented in this special issue of the Journal of Hydrology is brought together with associated information of relevance to the thematic area in this concluding paper. Some of the important gaps in our current knowledge are outlined with a view to identifying future research needs for the development of an integrated analysis of nutrients in river basins and their management. Identification of these needs is important if we are to meet the defined set of catchment management objectives specified under the EU Water Framework Directive that must be delivered against a specified timetable. The Directive raises wider concerns such as how to define 'good ecological status' and pertinent to this special issue: what role nutrients have in framing this definition. In this paper, the importance of nutrient pressures on receiving waters is evaluated in the context of the key scientific uncertainties and options for characterising the biological, physico-chemical and hydro-morphological parameters necessary to meet the science needs of the Directive. An assessment of the significance of nutrient mobility within river basins for current understanding of freshwater systems functioning on a catchment and basin scale is made together with an evaluation of where research on nutrient pressures should be focussed in order underpin effective management.

  5. Nutrient enrichment enhances black band disease progression in corals

    NASA Astrophysics Data System (ADS)

    Voss, Joshua D.; Richardson, Laurie L.

    2006-11-01

    Infectious diseases are recognized as significant contributors to the dramatic loss of corals observed worldwide. However, the causes of increased coral disease prevalence and severity are not well understood. One potential factor is elevated nutrient concentration related to localized anthropogenic activities such as inadequate waste water treatment or terrestrial runoff. In this study the effect of nutrient enrichment on the progression of black band disease (BBD) was investigated using both in situ and laboratory experiments. Experimental increases in localized nutrient availability using commercial time release fertilizer in situ resulted in doubling of BBD progression and coral tissue loss in the common reef framework coral Siderastrea siderea. Laboratory experiments in which artificially infected S. siderea colonies were exposed to increased nitrate concentrations (up to 3 μM) demonstrated similar increases in BBD progression. These findings provide evidence that the impacts of this disease on coral populations are exacerbated by nutrient enrichment and that management to curtail excess nutrient loading may be important for reducing coral cover loss due to BBD.

  6. Phytotoxicity studies with Lactuca sativa in soil and nutrient solution

    SciTech Connect

    Hulzebos, E.M.; Dirven-van Breemen, E.M.; Dis, W.A. van; Herbold, H.A.; Hoekstra, J.A.; Baerselman, R.; Gestel, C.A.M van ); Adema, D.M.M.; Henzen, L. )

    1993-06-01

    The toxicity of 76 priority pollutants to lettuce (Lactuca sativa) was determined in soil and in nutrient solution. In the first case a static and in the latter a semistatic exposure was established. Volatile and easily degradable compounds had high EC50 values in soil. In nutrient solution, however, several of these compounds were rather toxic. Quantitative structure activity relationships (QSARs) relating EC50 values to log K[sub ow] could be described for the toxicity in nutrient solution. Generally, the toxicity of the compounds increased with increasing lipophilicity. Deviations were caused by reactivity (N-containing compounds, double bonds in compounds), low lipophilicity, and EC50 values close to solubility. To relate toxicity in soil and nutrient solution, soil EC50 values were recalculated to values in the soil pore water using calculated adsorption coefficients. Estimated pore-water EC50 values showed a good correlation with values determined in nutrient solution but were not equal to these values. The differences can be attributed to differences in exposure.

  7. Less is more: Nutrient limitation induces cross-talk of nutrient sensing pathways with NAD+ homeostasis and contributes to longevity

    PubMed Central

    TSANG, Felicia; LIN, Su-Ju

    2016-01-01

    Nutrient sensing pathways and their regulation grant cells control over their metabolism and growth in response to changing nutrients. Factors that regulate nutrient sensing can also modulate longevity. Reduced activity of nutrient sensing pathways such as glucose-sensing PKA, nitrogen-sensing TOR and S6 kinase homolog Sch9 have been linked to increased life span in the yeast, Saccharomyces cerevisiae, and higher eukaryotes. Recently, reduced activity of amino acid sensing SPS pathway was also shown to increase yeast life span. Life span extension by reduced SPS activity requires enhanced NAD+ (nicotinamide adenine dinucleotide, oxidized form) and nicotinamide riboside (NR, a NAD+ precursor) homeostasis. Maintaining adequate NAD+ pools has been shown to play key roles in life span extension, but factors regulating NAD+ metabolism and homeostasis are not completely understood. Recently, NAD+ metabolism was also linked to the phosphate (Pi)-sensing PHO pathway in yeast. Canonical PHO activation requires Pi-starvation. Interestingly, NAD+ depletion without Pi-starvation was sufficient to induce PHO activation, increasing NR production and mobilization. Moreover, SPS signaling appears to function in parallel with PHO signaling components to regulate NR/NAD+ homeostasis. These studies suggest that NAD+ metabolism is likely controlled by and/or coordinated with multiple nutrient sensing pathways. Indeed, cross-regulation of PHO, PKA, TOR and Sch9 pathways was reported to potentially affect NAD+ metabolism; though detailed mechanisms remain unclear. This review discusses yeast longevity-related nutrient sensing pathways and possible mechanisms of life span extension, regulation of NAD+ homeostasis, and cross-talk among nutrient sensing pathways and NAD+ homeostasis.

  8. Less is more: Nutrient limitation induces cross-talk of nutrient sensing pathways with NAD+ homeostasis and contributes to longevity

    PubMed Central

    TSANG, Felicia; LIN, Su-Ju

    2016-01-01

    Nutrient sensing pathways and their regulation grant cells control over their metabolism and growth in response to changing nutrients. Factors that regulate nutrient sensing can also modulate longevity. Reduced activity of nutrient sensing pathways such as glucose-sensing PKA, nitrogen-sensing TOR and S6 kinase homolog Sch9 have been linked to increased life span in the yeast, Saccharomyces cerevisiae, and higher eukaryotes. Recently, reduced activity of amino acid sensing SPS pathway was also shown to increase yeast life span. Life span extension by reduced SPS activity requires enhanced NAD+ (nicotinamide adenine dinucleotide, oxidized form) and nicotinamide riboside (NR, a NAD+ precursor) homeostasis. Maintaining adequate NAD+ pools has been shown to play key roles in life span extension, but factors regulating NAD+ metabolism and homeostasis are not completely understood. Recently, NAD+ metabolism was also linked to the phosphate (Pi)-sensing PHO pathway in yeast. Canonical PHO activation requires Pi-starvation. Interestingly, NAD+ depletion without Pi-starvation was sufficient to induce PHO activation, increasing NR production and mobilization. Moreover, SPS signaling appears to function in parallel with PHO signaling components to regulate NR/NAD+ homeostasis. These studies suggest that NAD+ metabolism is likely controlled by and/or coordinated with multiple nutrient sensing pathways. Indeed, cross-regulation of PHO, PKA, TOR and Sch9 pathways was reported to potentially affect NAD+ metabolism; though detailed mechanisms remain unclear. This review discusses yeast longevity-related nutrient sensing pathways and possible mechanisms of life span extension, regulation of NAD+ homeostasis, and cross-talk among nutrient sensing pathways and NAD+ homeostasis. PMID:27683589

  9. Microbial community composition in sediments resists perturbation by nutrient enrichment.

    PubMed

    Bowen, Jennifer L; Ward, Bess B; Morrison, Hilary G; Hobbie, John E; Valiela, Ivan; Deegan, Linda A; Sogin, Mitchell L

    2011-09-01

    Functional redundancy in bacterial communities is expected to allow microbial assemblages to survive perturbation by allowing continuity in function despite compositional changes in communities. Recent evidence suggests, however, that microbial communities change both composition and function as a result of disturbance. We present evidence for a third response: resistance. We examined microbial community response to perturbation caused by nutrient enrichment in salt marsh sediments using deep pyrosequencing of 16S rRNA and functional gene microarrays targeting the nirS gene. Composition of the microbial community, as demonstrated by both genes, was unaffected by significant variations in external nutrient supply in our sampling locations, despite demonstrable and diverse nutrient-induced changes in many aspects of marsh ecology. The lack of response to external forcing demonstrates a remarkable uncoupling between microbial composition and ecosystem-level biogeochemical processes and suggests that sediment microbial communities are able to resist some forms of perturbation. PMID:21412346

  10. World fertilizer nutrient reserves: a view to the future.

    PubMed

    Fixen, Paul E; Johnston, Adrian M

    2012-03-30

    The increasing need for food production in subtropical regions likely translates to a need for additional plant nutrients. As a consequence, knowledge of world fertilizer nutrient reserves is of particular relevance to sustainable agriculture in the subtropics. The stewardship responsibilities of agriculture include the wise use of the raw materials from which commercial fertilizers are produced. Development and implementation of fertilizer best management practices with focus on the 4Rs-right source, right rate, right time, right place-are timely not only for short-term economic and environmental reasons, but also for the wise stewardship of the non-renewable nutrient resources upon which food, feed, fiber, and fuel production depend. PMID:22415449

  11. Nutrient attenuation in rivers and streams, Puget Sound Basin, Washington

    USGS Publications Warehouse

    Sheibley, Rich W.; Konrad, Christopher P.; Black, Robert W.

    2015-01-01

    From a management perspective, preservation and improvement of instream nutrient attenuation should focus on increasing the travel time through a reach and contact time of water sediment (reactive) surfaces and lowering nutrient concentrations (and loads) to avoid saturation of instream attenuation and increase attenuation efficiency. These goals can be reached by maintaining and restoring channel-flood plain connectivity, maintaining and restoring healthy riparian zones along streams, managing point and nonpoint nutrient loads to streams and rivers, and restoring channel features that promote attenuation such as the addition of woody debris and maintaining pool-riffle morphologies. Many of these management approaches are already being undertaken during projects aimed to restore quality salmon habitat. Therefore, there is a dual benefit to these projects that also may lead to enhanced potential for nitrogen and phosphorus attenuation.

  12. Assessing the susceptibility of two UK estuaries to nutrient enrichment

    NASA Astrophysics Data System (ADS)

    Kadiri, Margaret; Bockelmann-Evans, Bettina; Rauen, William B.

    2014-10-01

    The susceptibility of two UK estuaries, the Severn and Solva Estuaries to the risks and impacts of nutrient enrichment was investigated in this study by examining nutrients, dissolved oxygen (DO) and turbidity concentrations in the estuaries and applying a risk assessment model based on the UK's Comprehensive Studies Task Team (CSTT) modelling approach. Both estuaries were found to be nutrient enriched. However, there was no evidence of oxygen depletion in the Severn and algal blooms were not observed due to high turbidity, strong tidal currents and tidally induced vertical mixing conditions in the estuary. Although algal blooms were observed in the Solva Estuary, the estuary was well-oxygenated due to the relatively high water exchange rate and consistent rapid flushing in the estuary. The conditions in the Solva Estuary were predicted to be favourable for phytoplankton productivity and the wider potential implications for future water quality protection strategies in the Solva were discussed.

  13. Method and apparatus for determining nutrient stimulation of biological processes

    DOEpatents

    Colwell, Frederick S.; Geesey, Gill G.; Gillis, Richard J.; Lehman, R. Michael

    1999-01-01

    A method and apparatus for determining the nutrients to stimulate microorganisms in a particular environment. A representative sample of microorganisms from a particular environment are contacted with multiple support means wherein each support means has intimately associated with the surface of the support means a different nutrient composition for said microorganisms in said sample. The multiple support means is allowed to remain in contact with the microorganisms in the sample for a time period sufficient to measure difference in microorganism effects for the multiple support means. Microorganism effects for the multiple support means are then measured and compared. The invention is particularly adaptable to being conducted in situ. The additional steps of regulating nutrients added to the particular environment of microorganisms can enhance the desired results. Biological systems particularly suitable for this invention are bioremediation, biologically enhanced oil recovery, biological leaching of metals, and agricultural bioprocesses.

  14. Method and apparatus for determining nutrient stimulation of biological processes

    DOEpatents

    Colwell, Frederick S.; Geesey, Gill G.; Gillis, Richard J.; Lehman, R. Michael

    1997-01-01

    A method and apparatus for determining the nutrients to stimulate microorganisms in a particular environment. A representative sample of microorganisms from a particular environment are contacted with multiple support means wherein each support means has intimately associated with the surface of the support means a different nutrient composition for said microorganisms in said sample. The multiple support means is allowed to remain in contact with the microorganisms in the sample for a time period sufficient to measure differences in microorganism effects for the multiple support means. Microorganism effects for the multiple support means are then measured and compared. The invention is particularly adaptable to being conducted in situ. The additional steps of regulating nutrients added to the particular environment of microorganisms can enhance the desired results. Biological systems particularly suitable for this invention are bioremediation, biologically enhanced oil recovery, biological leaching of metals, and agricultural bioprocesses.

  15. Method and apparatus for determining nutrient stimulation of biological processes

    DOEpatents

    Colwell, F.S.; Geesey, G.G.; Gillis, R.J.; Lehman, R.M.

    1997-11-11

    A method and apparatus is described for determining the nutrients to stimulate microorganisms in a particular environment. A representative sample of microorganisms from a particular environment are contacted with multiple support means wherein each support means has intimately associated with the surface of the support means a different nutrient composition for said microorganisms in said sample. The multiple support means is allowed to remain in contact with the microorganisms in the sample for a time period sufficient to measure differences in microorganism effects for the multiple support means. Microorganism effects for the multiple support means are then measured and compared. The invention is particularly adaptable to being conducted in situ. The additional steps of regulating nutrients added to the particular environment of microorganisms can enhance the desired results. Biological systems particularly suitable for this invention are bioremediation, biologically enhanced oil recovery, biological leaching of metals, and agricultural bioprocesses. 5 figs.

  16. Method and apparatus for determining nutrient stimulation of biological processes

    DOEpatents

    Colwell, F.S.; Geesey, G.G.; Gillis, R.J.; Lehman, R.M.

    1999-07-13

    A method and apparatus are disclosed for determining the nutrients to stimulate microorganisms in a particular environment. A representative sample of microorganisms from a particular environment are contacted with multiple support means wherein each support means has intimately associated with the surface of the support means a different nutrient composition for microorganisms in the sample. The multiple support means is allowed to remain in contact with the microorganisms in the sample for a time period sufficient to measure difference in microorganism effects for the multiple support means. Microorganism effects for the multiple support means are then measured and compared. The invention is particularly adaptable to being conducted in situ. The additional steps of regulating nutrients added to the particular environment of microorganisms can enhance the desired results. Biological systems particularly suitable for this invention are bioremediation, biologically enhanced oil recovery, biological leaching of metals, and agricultural bioprocesses. 5 figs.

  17. The Everglades are still threatened by excess nutrients

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Atreyee

    2012-10-01

    Since 1985, a Florida state agency constructed and maintained hundreds of square kilometers of wetlands built to regulate the amount of nutrients reaching the Everglades in southern Florida. However, Zapata-Rios et al. show that this is proving to be ineffective in controlling concentrations of phosphorous, a key nutrient, in the surface waters of the wetland. Historically, the Everglades has been a nutrient-poor environment, a characteristic that determines the delicate ecological balance and distinct flora and fauna in this region. Agricultural development and urbanization since the 1800s have not only claimed two- thirds of the natural Everglades (only 6000 square kilometers now exist in their natural form) but have also dramatically increased phosphorus levels in surface water, at times exceeding the acceptable limit of 10 micrograms per liter by severalfold.

  18. Recycling of food waste as nutrients in Chlorella vulgaris cultivation.

    PubMed

    Lau, Kin Yan; Pleissner, Daniel; Lin, Carol Sze Ki

    2014-10-01

    Heterotrophic cultivation of Chlorella vulgaris was investigated in food waste hydrolysate. The highest exponential growth rate in terms of biomass of 0.8day(-1) was obtained in a hydrolysate consisting of 17.9gL(-1) glucose, 0.1gL(-1) free amino nitrogen, 0.3gL(-1) phosphate and 4.8mgL(-1) nitrate, while the growth rate was reduced in higher concentrated hydrolysates. C. vulgaris utilized the nutrients recovered from food waste for the formation of biomass and 0.9g biomass was produced per gram glucose consumed. The microalgal biomass produced in nutrient sufficient batch cultures consisted of around 400mgg(-1) carbohydrates, 200mgg(-1) proteins and 200mgg(-1) lipids. The conversion of nutrients derived from food waste and the balanced biomass composition make C. vulgaris a promising strain for the recycling of food waste in food, feed and fuel productions.

  19. Food waste as nutrient source in heterotrophic microalgae cultivation.

    PubMed

    Pleissner, Daniel; Lam, Wan Chi; Sun, Zheng; Lin, Carol Sze Ki

    2013-06-01

    Glucose, free amino nitrogen (FAN), and phosphate were recovered from food waste by fungal hydrolysis using Aspergillus awamori and Aspergillus oryzae. Using 100g food waste (dry weight), 31.9 g glucose, 0.28 g FAN, and 0.38 g phosphate were recovered after 24h of hydrolysis. The pure hydrolysate has then been used as culture medium and nutrient source for the two heterotrophic microalgae Schizochytrium mangrovei and Chlorella pyrenoidosa, S. mangrovei and C. pyrenoidosa grew well on the complex food waste hydrolysate by utilizing the nutrients recovered. At the end of fermentation 10-20 g biomass were produced rich in carbohydrates, lipids, proteins, and saturated and polyunsaturated fatty acids. Results of this study revealed the potential of food waste hydrolysate as culture medium and nutrient source in microalgae cultivation.

  20. Hydrologic processes and nutrient dynamics in a pristine mountain catchment

    USGS Publications Warehouse

    F. Richard Hauer,; Fagre, Daniel B.; Stanford, Jack A.

    2002-01-01

    Nutrient dynamics in watersheds have been used as an ecosystem-level indicator of overall ecosystem function or response to disturbance (e.g. Borman.N et al. 1974, WEBSTER et al. 1992). The examination of nutrients has been evaluated to determine responses to logging practices or other changes in watershed land use. Nutrient dynamics have been related to changing physical and biological characteristics (Mulholl AND 1992, CHESTNUT & McDowell 2000). Herein, the concentrations and dynamics of nitrogen, phosphorus and particulate organic carbon were examined in a large pristine watershed because they are affected by changes in discharge directly from the catchment and after passage through a large oligotrophic lake. 

  1. Bilateral Femoral Nutrient Foraminal Cement Penetration during Total Hip Arthroplasty

    PubMed Central

    Coomber, Ross; Bhumbra, Rej S; Marston, Robert

    2012-01-01

    Introduction: Cement pressurisation is important for the insertion of both the acetabular and femoral components during Total Hip Arthroplasty (THA). Secondary to pressurization the rare phenomenon of unilateral cement incursion into the nutrient foramen has previously been reported. No bilateral case has been reported to date. This has implications both for misdiagnosis of periprosthetic fractures and for medico-legal consequences due to a presumed adverse intra-operative event. Case Report: We present a case report of a 59 year old, caucasian female who underwent staged bilateral cemented Stanmore THA. The post-operative radiographs demonstrate evidence of bilateral nutrient foramen penetration intra-operatively by standard viscosity cement. The patient suffered no adverse consequences. Conclusions: In summary, cement extravasation into the nutrient foramen is an important differential to be considered in presence of posterior-medial cement in the diaphysis of femur following THA. This requires no further intervention and has no effect on the outcome.

  2. Microbial community composition in sediments resists perturbation by nutrient enrichment

    PubMed Central

    Bowen, Jennifer L; Ward, Bess B; Morrison, Hilary G; Hobbie, John E; Valiela, Ivan; Deegan, Linda A; Sogin, Mitchell L

    2011-01-01

    Functional redundancy in bacterial communities is expected to allow microbial assemblages to survive perturbation by allowing continuity in function despite compositional changes in communities. Recent evidence suggests, however, that microbial communities change both composition and function as a result of disturbance. We present evidence for a third response: resistance. We examined microbial community response to perturbation caused by nutrient enrichment in salt marsh sediments using deep pyrosequencing of 16S rRNA and functional gene microarrays targeting the nirS gene. Composition of the microbial community, as demonstrated by both genes, was unaffected by significant variations in external nutrient supply in our sampling locations, despite demonstrable and diverse nutrient-induced changes in many aspects of marsh ecology. The lack of response to external forcing demonstrates a remarkable uncoupling between microbial composition and ecosystem-level biogeochemical processes and suggests that sediment microbial communities are able to resist some forms of perturbation. PMID:21412346

  3. Sediment and nutrient losses from an irrigated watershed.

    NASA Astrophysics Data System (ADS)

    Bjorneberg, D.; Ippolito, J.

    2011-12-01

    Irrigated agriculture is an essential part of stable food and fiber production. However, water returning from irrigated watersheds can contain excess sediment, nutrients and salts. Applying polyacrylamide to furrow irrigated fields reduces erosion 60 to 90%. Converting from furrow irrigation to sprinkler irrigation eliminates planned irrigation runoff necessary for uniform water application. Installing sediment ponds removes 50 to 80% of the suspended sediment from water before it flows back to major water bodies. In southern Idaho, irrigation watershed monitoring showed that implementing these conservation practices has reduced average suspended sediment loss from 460 kg/ha in 1970 to less than 100 kg/ha in 2005. These practices, however, have had less effect on soluble nutrients. Median nitrate concentrations have almost doubled from 1970 to 2005. Current research is focusing on identifying practices to reduce soluble nutrient losses.

  4. Intestinal organoids for assessing nutrient transport, sensing and incretin secretion.

    PubMed

    Zietek, Tamara; Rath, Eva; Haller, Dirk; Daniel, Hannelore

    2015-11-19

    Intestinal nutrient transport and sensing are of emerging interest in research on obesity and diabetes and as drug targets. Appropriate in vitro models are lacking that allow both, studies on transport processes as well as sensing and subsequent incretin hormone secretion including intracellular signaling. We here demonstrate that murine small-intestinal organoids are the first in vitro model system enabling concurrent investigations of nutrient and drug transport, sensing and incretin hormone secretion as well as fluorescent live-cell imaging of intracellular signaling processes. By generating organoid cultures from wild type mice and animals lacking different nutrient transporters, we show that organoids preserve the main phenotypic features and functional characteristics of the intestine. This turns them into the best in vitro model currently available and opens new avenues for basic as well as medical research.

  5. Intestinal organoids for assessing nutrient transport, sensing and incretin secretion

    PubMed Central

    Zietek, Tamara; Rath, Eva; Haller, Dirk; Daniel, Hannelore

    2015-01-01

    Intestinal nutrient transport and sensing are of emerging interest in research on obesity and diabetes and as drug targets. Appropriate in vitro models are lacking that allow both, studies on transport processes as well as sensing and subsequent incretin hormone secretion including intracellular signaling. We here demonstrate that murine small-intestinal organoids are the first in vitro model system enabling concurrent investigations of nutrient and drug transport, sensing and incretin hormone secretion as well as fluorescent live-cell imaging of intracellular signaling processes. By generating organoid cultures from wild type mice and animals lacking different nutrient transporters, we show that organoids preserve the main phenotypic features and functional characteristics of the intestine. This turns them into the best in vitro model currently available and opens new avenues for basic as well as medical research. PMID:26582215

  6. Global Expanded Nutrient Supply (GENuS) Model: A New Method for Estimating the Global Dietary Supply of Nutrients.

    PubMed

    Smith, Matthew R; Micha, Renata; Golden, Christopher D; Mozaffarian, Dariush; Myers, Samuel S

    2016-01-01

    Insufficient data exist for accurate estimation of global nutrient supplies. Commonly used global datasets contain key weaknesses: 1) data with global coverage, such as the FAO food balance sheets, lack specific information about many individual foods and no information on micronutrient supplies nor heterogeneity among subnational populations, while 2) household surveys provide a closer approximation of consumption, but are often not nationally representative, do not commonly capture many foods consumed outside of the home, and only provide adequate information for a few select populations. Here, we attempt to improve upon these datasets by constructing a new model--the Global Expanded Nutrient Supply (GENuS) model--to estimate nutrient availabilities for 23 individual nutrients across 225 food categories for thirty-four age-sex groups in nearly all countries. Furthermore, the model provides historical trends in dietary nutritional supplies at the national level using data from 1961-2011. We determine supplies of edible food by expanding the food balance sheet data using FAO production and trade data to increase food supply estimates from 98 to 221 food groups, and then estimate the proportion of major cereals being processed to flours to increase to 225. Next, we estimate intake among twenty-six demographic groups (ages 20+, both sexes) in each country by using data taken from the Global Dietary Database, which uses nationally representative surveys to relate national averages of food consumption to individual age and sex-groups; for children and adolescents where GDD data does not yet exist, average calorie-adjusted amounts are assumed. Finally, we match food supplies with nutrient densities from regional food composition tables to estimate nutrient supplies, running Monte Carlo simulations to find the range of potential nutrient supplies provided by the diet. To validate our new method, we compare the GENuS estimates of nutrient supplies against independent

  7. Global Expanded Nutrient Supply (GENuS) Model: A New Method for Estimating the Global Dietary Supply of Nutrients

    PubMed Central

    Golden, Christopher D.; Mozaffarian, Dariush

    2016-01-01

    Insufficient data exist for accurate estimation of global nutrient supplies. Commonly used global datasets contain key weaknesses: 1) data with global coverage, such as the FAO food balance sheets, lack specific information about many individual foods and no information on micronutrient supplies nor heterogeneity among subnational populations, while 2) household surveys provide a closer approximation of consumption, but are often not nationally representative, do not commonly capture many foods consumed outside of the home, and only provide adequate information for a few select populations. Here, we attempt to improve upon these datasets by constructing a new model—the Global Expanded Nutrient Supply (GENuS) model—to estimate nutrient availabilities for 23 individual nutrients across 225 food categories for thirty-four age-sex groups in nearly all countries. Furthermore, the model provides historical trends in dietary nutritional supplies at the national level using data from 1961–2011. We determine supplies of edible food by expanding the food balance sheet data using FAO production and trade data to increase food supply estimates from 98 to 221 food groups, and then estimate the proportion of major cereals being processed to flours to increase to 225. Next, we estimate intake among twenty-six demographic groups (ages 20+, both sexes) in each country by using data taken from the Global Dietary Database, which uses nationally representative surveys to relate national averages of food consumption to individual age and sex-groups; for children and adolescents where GDD data does not yet exist, average calorie-adjusted amounts are assumed. Finally, we match food supplies with nutrient densities from regional food composition tables to estimate nutrient supplies, running Monte Carlo simulations to find the range of potential nutrient supplies provided by the diet. To validate our new method, we compare the GENuS estimates of nutrient supplies against independent

  8. Global Expanded Nutrient Supply (GENuS) Model: A New Method for Estimating the Global Dietary Supply of Nutrients.

    PubMed

    Smith, Matthew R; Micha, Renata; Golden, Christopher D; Mozaffarian, Dariush; Myers, Samuel S

    2016-01-01

    Insufficient data exist for accurate estimation of global nutrient supplies. Commonly used global datasets contain key weaknesses: 1) data with global coverage, such as the FAO food balance sheets, lack specific information about many individual foods and no information on micronutrient supplies nor heterogeneity among subnational populations, while 2) household surveys provide a closer approximation of consumption, but are often not nationally representative, do not commonly capture many foods consumed outside of the home, and only provide adequate information for a few select populations. Here, we attempt to improve upon these datasets by constructing a new model--the Global Expanded Nutrient Supply (GENuS) model--to estimate nutrient availabilities for 23 individual nutrients across 225 food categories for thirty-four age-sex groups in nearly all countries. Furthermore, the model provides historical trends in dietary nutritional supplies at the national level using data from 1961-2011. We determine supplies of edible food by expanding the food balance sheet data using FAO production and trade data to increase food supply estimates from 98 to 221 food groups, and then estimate the proportion of major cereals being processed to flours to increase to 225. Next, we estimate intake among twenty-six demographic groups (ages 20+, both sexes) in each country by using data taken from the Global Dietary Database, which uses nationally representative surveys to relate national averages of food consumption to individual age and sex-groups; for children and adolescents where GDD data does not yet exist, average calorie-adjusted amounts are assumed. Finally, we match food supplies with nutrient densities from regional food composition tables to estimate nutrient supplies, running Monte Carlo simulations to find the range of potential nutrient supplies provided by the diet. To validate our new method, we compare the GENuS estimates of nutrient supplies against independent

  9. Accumulation of arsenic and nutrients by castor bean plants grown on an As-enriched nutrient solution.

    PubMed

    Melo, E E C; Costa, E T S; Guilherme, L R G; Faquin, V; Nascimento, C W A

    2009-08-30

    Phytoextraction is a remediation technique that consists in using plants to remove contaminants from soils and water. This study evaluated arsenic (As) accumulation in Castor bean (Ricinus communis cv. Guarany) grown in nutrient solution in order to assess its phytoextraction ability. Castor bean plants were grown under greenhouse conditions in pots containing a nutrient solution amended with increasing doses of As (0, 10, 50, 100, 250, 500 and 5000 microg L(-1)) in a completely randomized design with four replications. Shoot and roots dry matter production as well as arsenic and nutrient tissue concentrations were measured at the end of the experiment. The results showed that increasing As concentration in nutrient solution caused a decrease in shoot and root biomass but did not result in severe toxicity symptoms in castor bean growing under a range of As concentration from 0 to 5000 microg L(-1). The As doses tested did not affect the accumulation of nutrients by castor bean. Although castor bean did not pose characteristics of a plant suitable for commercial phytoextraction, it could be useful for revegetation of As-contaminated areas while providing an additional income by oil production.

  10. Nutrient concentrations and fluxes in the upper catchment of the Miyun Reservoir, China, and potential nutrient reduction strategies.

    PubMed

    Jiao, Jian; Du, Pengfei; Lang, Cong

    2015-03-01

    The Miyun Reservoir is Beijing's main drinking water source. Increased nutrient levels in the reservoir have resulted in an increased risk of harmful algal blooms. One hundred ten water samples were collected at a range of spatial scales in the upper catchment of the Miyun Reservoir and were analyzed for total nitrogen (TN), nitrate (NO3 (-)-N), ammonium (NH4 (+)-N), total phosphorus (TP), and the potassium permanganate index (CODMn). Empirical equations were developed from relationships between nutrient concentrations and the main controls on nutrient, and were used to identify parts of the catchment that should be targeted with nutrient load reduction measures. Cropland was the main source of sediment for the streams, and much of the phosphorus was associated with sediment. The annual mean TP concentrations were closely correlated with both the annual mean suspended sediment concentrations and the ratio of the cropland area to the total basin area. There was a linear relationship between the annual mean TN concentration and the population density in the basins. Soil conservation may play an important role in reducing TP concentrations in the upper reaches of the Chao and Bai Rivers. It may be useful to (1) construct natural riparian buffers and vegetated buffers along croplands close to the watercourses, (2) implement management strategies to reduce nitrogen (N) fertilizer applications, and (3) construct additional wetlands to reduce nutrient loads in the study area.

  11. Nutrient concentrations and fluxes in the upper catchment of the Miyun Reservoir, China, and potential nutrient reduction strategies.

    PubMed

    Jiao, Jian; Du, Pengfei; Lang, Cong

    2015-03-01

    The Miyun Reservoir is Beijing's main drinking water source. Increased nutrient levels in the reservoir have resulted in an increased risk of harmful algal blooms. One hundred ten water samples were collected at a range of spatial scales in the upper catchment of the Miyun Reservoir and were analyzed for total nitrogen (TN), nitrate (NO3 (-)-N), ammonium (NH4 (+)-N), total phosphorus (TP), and the potassium permanganate index (CODMn). Empirical equations were developed from relationships between nutrient concentrations and the main controls on nutrient, and were used to identify parts of the catchment that should be targeted with nutrient load reduction measures. Cropland was the main source of sediment for the streams, and much of the phosphorus was associated with sediment. The annual mean TP concentrations were closely correlated with both the annual mean suspended sediment concentrations and the ratio of the cropland area to the total basin area. There was a linear relationship between the annual mean TN concentration and the population density in the basins. Soil conservation may play an important role in reducing TP concentrations in the upper reaches of the Chao and Bai Rivers. It may be useful to (1) construct natural riparian buffers and vegetated buffers along croplands close to the watercourses, (2) implement management strategies to reduce nitrogen (N) fertilizer applications, and (3) construct additional wetlands to reduce nutrient loads in the study area. PMID:25673273

  12. Shedding light onto nutrient responses of arbuscular mycorrhizal plants: nutrient interactions may lead to unpredicted outcomes of the symbiosis.

    PubMed

    Corrêa, Ana; Cruz, Cristina; Pérez-Tienda, Jacob; Ferrol, Nuria

    2014-05-01

    The role and importance of arbuscular mycorrhizae (AM) in plant nitrogen (N) nutrition is uncertain. We propose that this be clarified by using more integrative experimental designs, with the use of a gradient of N supply and the quantification of an extensive array of plant nutrient contents. Using such an experimental design, we investigated AM effects on plant N nutrition, whether the mycorrhizal N response (MNR) determines the mycorrhizal growth response (MGR), and how MNR influences plants' C economy. Oryza sativa plants were inoculated with Rhizophagus irregularis or Funneliformis mossae. AM effects were studied along a gradient of N supplies. Biomass, photosynthesis, nutrient and starch contents, mycorrhizal colonization and OsPT11 gene expression were measured. C investment in fungal growth was estimated. Results showed that, in rice, MGR was dependent on AM nutrient uptake effects, namely on the synergy between N and Zn, and not on C expenditure. The supply of C to the fungus was dependent on the plant's nutrient demand, indicated by high shoot C/N or low %N. We conclude that one of the real reasons for the negative MGR of rice, Zn deficiency of AMF plants, would have remained hidden without an experimental design allowing the observation of plants' response to AM along gradients of nutrient concentrations. Adopting more integrative and comprehensive experimental approaches in mycorrhizal studies seems therefore essential if we are to achieve a true understanding of AM function, namely of the mechanisms of C/N exchange regulation in AM. PMID:24656333

  13. Alternative nutrient sources for biotechnological use of Sporosarcina pasteurii.

    PubMed

    Cuzman, Oana Adriana; Richter, Katharina; Wittig, Linda; Tiano, Piero

    2015-06-01

    The potential use of Sporosarcina pasteurii in possible biotechnological applications on a large scale (ground improvement, consolidation of building structures and ornamental stone, or in developing bio-materials for the building industry), is based on its ability to produce high amounts of carbonate in a short period of time via urea hydrolysis. Industrial biomass production would have a low environmental impact and would be most economical if the standard growth media could be replaced with alternative nutrient sources, such as byproducts or wastes from other industries, or other low cost ingredients. The use of cost effective ingredients must guarantee ureolytic activities and growth conditions that are comparable to those resulting from the standard nutrient medium. In this work, three types of alternative media were tested for growing the ureolytic active bacteria S. pasteurii: (1) alternative nutrient sources such as industrial wastes resulting from the dairy and brewery industries, (2) fertilizer urea as an alternative urea substitute, and (3) different types of poultry manure based fertilizers as nutrient and urea substitutes. The comparison between the standard media, the nutrient alternatives and urea substitutes was possible by taking the protein concentration and nitrogen content into account. Bacterial activity was evaluated in terms of biomass changes over time (CFU, optical density, ATP measurements) and indirect estimation of the enzyme production (Nessler assay, conductivity measurement). The results revealed that some of the dairy wastes tested, such as whey and buttermilk, are potential alternative nutrients for bacterial development, while the urea fertilizer is perfectly suitable as an economical substitute for pure laboratory grade urea. PMID:25813200

  14. Carbon and nutrient use efficiencies optimally balance stoichiometric imbalances

    NASA Astrophysics Data System (ADS)

    Manzoni, Stefano; Čapek, Petr; Lindahl, Björn; Mooshammer, Maria; Richter, Andreas; Šantrůčková, Hana

    2016-04-01

    Decomposer organisms face large stoichiometric imbalances because their food is generally poor in nutrients compared to the decomposer cellular composition. The presence of excess carbon (C) requires adaptations to utilize nutrients effectively while disposing of or investing excess C. As food composition changes, these adaptations lead to variable C- and nutrient-use efficiencies (defined as the ratios of C and nutrients used for growth over the amounts consumed). For organisms to be ecologically competitive, these changes in efficiencies with resource stoichiometry have to balance advantages and disadvantages in an optimal way. We hypothesize that efficiencies are varied so that community growth rate is optimized along stoichiometric gradients of their resources. Building from previous theories, we predict that maximum growth is achieved when C and nutrients are co-limiting, so that the maximum C-use efficiency is reached, and nutrient release is minimized. This optimality principle is expected to be applicable across terrestrial-aquatic borders, to various elements, and at different trophic levels. While the growth rate maximization hypothesis has been evaluated for consumers and predators, in this contribution we test it for terrestrial and aquatic decomposers degrading resources across wide stoichiometry gradients. The optimality hypothesis predicts constant efficiencies at low substrate C:N and C:P, whereas above a stoichiometric threshold, C-use efficiency declines and nitrogen- and phosphorus-use efficiencies increase up to one. Thus, high resource C:N and C:P lead to low C-use efficiency, but effective retention of nitrogen and phosphorus. Predictions are broadly consistent with efficiency trends in decomposer communities across terrestrial and aquatic ecosystems.

  15. Nutrient Enrichment Coupled with Sedimentation Favors Sea Anemones over Corals

    PubMed Central

    Liu, Pi-Jen; Hsin, Min-Chieh; Huang, Yen-Hsun; Fan, Tung-Yung; Meng, Pei-Jie; Lu, Chung-Cheng; Lin, Hsing-Juh

    2015-01-01

    Fine sediments, which account for the majority of total fluvial sediment flux, have been suggested to degrade coral reefs on a global scale. Furthermore, sediment impacts can be exacerbated by extreme rainfall events associated with global climate change and anthropogenic nutrient enrichment. We report the findings from a series of mesocosm experiments exploring the effects of short-term sedimentation and nutrient enrichment on the interactions between the hard coral Acropora muricata, the sea anemone Mesactinia ganesis, and the green macroalga Codium edule. Mesocosms were manipulated to simulate either unimpacted reefs or reefs exposed to elevated levels of fine sediments for 10 or 14 days to simulate the effects of heavy rainfall. The first and second experiments were aimed to examine the effects of inorganic and organic sediments, respectively. The third experiment was designed to examine the interactive effects of nutrient enrichment and elevated sediment loads. Neither inorganic nor organic sediment loadings significantly affected the physiological performance of the coral, but, importantly, did reduce its ability to compete with other organisms. Photosynthetic efficiencies of both the green macroalga and the sea anemone increased in response to both sediment loadings when they were simultaneously exposed to nutrient enrichment. While organic sediment loading increased the nitrogen content of the green macroalga in the first experiment, inorganic sediment loading increased its phosphorus content in the second experiment. The coral mortality due to sea anemones attack was significantly greater upon exposure to enriched levels of organic sediments and nutrients. Our findings suggest that the combined effects of short-term sedimentation and nutrient enrichment could cause replacement of corals by sea anemones on certain coral reefs. PMID:25897844

  16. Predator-driven nutrient recycling in California stream ecosystems.

    PubMed

    Munshaw, Robin G; Palen, Wendy J; Courcelles, Danielle M; Finlay, Jacques C

    2013-01-01

    Nutrient recycling by consumers in streams can influence ecosystem nutrient availability and the assemblage and growth of photoautotrophs. Stream fishes can play a large role in nutrient recycling, but contributions by other vertebrates to overall recycling rates remain poorly studied. In tributaries of the Pacific Northwest, coastal giant salamanders (Dicamptodon tenebrosus) occur at high densities alongside steelhead trout (Oncorhynchus mykiss) and are top aquatic predators. We surveyed the density and body size distributions of D. tenebrosus and O. mykiss in a California tributary stream, combined with a field study to determine mass-specific excretion rates of ammonium (N) and total dissolved phosphorus (P) for D. tenebrosus. We estimated O. mykiss excretion rates (N, P) by bioenergetics using field-collected data on the nutrient composition of O. mykiss diets from the same system. Despite lower abundance, D. tenebrosus biomass was 2.5 times higher than O. mykiss. Mass-specific excretion summed over 170 m of stream revealed that O. mykiss recycle 1.7 times more N, and 1.2 times more P than D. tenebrosus, and had a higher N:P ratio (8.7) than that of D. tenebrosus (6.0), or the two species combined (7.5). Through simulated trade-offs in biomass, we estimate that shifts from salamander biomass toward fish biomass have the potential to ease nutrient limitation in forested tributary streams. These results suggest that natural and anthropogenic heterogeneity in the relative abundance of these vertebrates and variation in the uptake rates across river networks can affect broad-scale patterns of nutrient limitation.

  17. Effects of nutrient enrichment on mangrove leaf litter decomposition.

    PubMed

    Keuskamp, Joost A; Hefting, Mariet M; Dingemans, Bas J J; Verhoeven, Jos T A; Feller, Ilka C

    2015-03-01

    Nutrient enrichment of mangroves, a common phenomenon along densely populated coastlines, may negatively affect mangrove ecosystems by modifying internal carbon and nutrient cycling. The decomposition of litter exerts a strong influence on these processes and is potentially modified by eutrophication. This study describes effects of N and P enrichment on litter decomposition rate and mineralisation/immobilisation patterns. By making use of reciprocal litter transplantation experiments among fertiliser treatments, it was tested if nutrient addition primarily acts on the primary producers (i.e. changes in litter quantity and quality) or on the microbial decomposers (i.e. changes in nutrient limitation for decomposition). Measurements were done in two mangrove forests where primary production was either limited by N or by P, which had been subject to at least 5 years of experimental N and P fertilisation. Results of this study indicated that decomposers were always N-limited regardless of the limitation of the primary producers. This leads to a differential nutrient limitation between decomposers and primary producers in sites where mangrove production was P-limited. In these sites, fertilisation with P caused litter quality to change, resulting in a higher decomposition rate. This study shows that direct effects of fertilisation on decomposition through an effect on decomposer nutrient availability might be non-significant, while the indirect effects through modifying litter quality might be quite substantial in mangroves. Our results show no indication that eutrophication increases decomposition without stimulating primary production. Therefore we do not expect a decline in carbon sequestration as a result of eutrophication of mangrove ecosystems.

  18. Nutrient enrichment coupled with sedimentation favors sea anemones over corals.

    PubMed

    Liu, Pi-Jen; Hsin, Min-Chieh; Huang, Yen-Hsun; Fan, Tung-Yung; Meng, Pei-Jie; Lu, Chung-Cheng; Lin, Hsing-Juh

    2015-01-01

    Fine sediments, which account for the majority of total fluvial sediment flux, have been suggested to degrade coral reefs on a global scale. Furthermore, sediment impacts can be exacerbated by extreme rainfall events associated with global climate change and anthropogenic nutrient enrichment. We report the findings from a series of mesocosm experiments exploring the effects of short-term sedimentation and nutrient enrichment on the interactions between the hard coral Acropora muricata, the sea anemone Mesactinia ganesis, and the green macroalga Codium edule. Mesocosms were manipulated to simulate either unimpacted reefs or reefs exposed to elevated levels of fine sediments for 10 or 14 days to simulate the effects of heavy rainfall. The first and second experiments were aimed to examine the effects of inorganic and organic sediments, respectively. The third experiment was designed to examine the interactive effects of nutrient enrichment and elevated sediment loads. Neither inorganic nor organic sediment loadings significantly affected the physiological performance of the coral, but, importantly, did reduce its ability to compete with other organisms. Photosynthetic efficiencies of both the green macroalga and the sea anemone increased in response to both sediment loadings when they were simultaneously exposed to nutrient enrichment. While organic sediment loading increased the nitrogen content of the green macroalga in the first experiment, inorganic sediment loading increased its phosphorus content in the second experiment. The coral mortality due to sea anemones attack was significantly greater upon exposure to enriched levels of organic sediments and nutrients. Our findings suggest that the combined effects of short-term sedimentation and nutrient enrichment could cause replacement of corals by sea anemones on certain coral reefs. PMID:25897844

  19. Evidence for sensitivity of dune wetlands to groundwater nutrients.

    PubMed

    Rhymes, Jennifer; Wallace, Hilary; Fenner, Nathalie; Jones, Laurence

    2014-08-15

    Dune slacks are seasonal wetlands, high in biodiversity, which experience considerable within-year and between-year variations in water-table. They are subject to many pressures including climate change, land use change and eutrophication. Despite their biological importance and the threats facing them, the hydrological and nutrient parameters that influence their soil properties and biodiversity are poorly understood and there have been no empirical studies to date testing for biological effects in dune systems resulting from groundwater nutrients at low concentrations. In this study we examined the impact of groundwater nutrients on water chemistry, soil chemistry and vegetation composition of dune slacks at three distance classes (0-150 m, 150-300 m, 300-450 m) away from known (off-site) nutrient sources at Aberffraw dunes in North Wales, whilst accounting for differences in water-table regime. Groundwater nitrate and dissolved inorganic nitrogen (DIN) and soil nitrate and nitrite all had significantly higher concentrations closest to the nutrient source. Multivariate analysis showed that although plant species composition within this site was primarily controlled by water table depth and water table fluctuation, nitrogen from groundwater also influenced species composition, independently of water table and soil development. A model containing all hydrological parameters explained 17% of the total species variance; an additional 7% was explained following the addition of NO3 to this model. Areas exposed to elevated, but still relatively low, groundwater nutrient concentrations (mean 0.204 mg/L+/-0.091 of DIN) had greater abundance of nitrophilous species and fewer basipholous species than in areas with lower concentrations. This shows that clear biological impact occurs below previously suggested DIN thresholds of 0.20-0.40 (mg/L).

  20. Nutrient-dependent/pheromone-controlled adaptive evolution: a model

    PubMed Central

    Kohl, James Vaughn

    2013-01-01

    Background The prenatal migration of gonadotropin-releasing hormone (GnRH) neurosecretory neurons allows nutrients and human pheromones to alter GnRH pulsatility, which modulates the concurrent maturation of the neuroendocrine, reproductive, and central nervous systems, thus influencing the development of ingestive behavior, reproductive sexual behavior, and other behaviors. Methods This model details how chemical ecology drives adaptive evolution via: (1) ecological niche construction, (2) social niche construction, (3) neurogenic niche construction, and (4) socio-cognitive niche construction. This model exemplifies the epigenetic effects of olfactory/pheromonal conditioning, which alters genetically predisposed, nutrient-dependent, hormone-driven mammalian behavior and choices for pheromones that control reproduction via their effects on luteinizing hormone (LH) and systems biology. Results Nutrients are metabolized to pheromones that condition behavior in the same way that food odors condition behavior associated with food preferences. The epigenetic effects of olfactory/pheromonal input calibrate and standardize molecular mechanisms for genetically predisposed receptor-mediated changes in intracellular signaling and stochastic gene expression in GnRH neurosecretory neurons of brain tissue. For example, glucose and pheromones alter the hypothalamic secretion of GnRH and LH. A form of GnRH associated with sexual orientation in yeasts links control of the feedback loops and developmental processes required for nutrient acquisition, movement, reproduction, and the diversification of species from microbes to man. Conclusion An environmental drive evolved from that of nutrient ingestion in unicellular organisms to that of pheromone-controlled socialization in insects. In mammals, food odors and pheromones cause changes in hormones such as LH, which has developmental affects on pheromone-controlled sexual behavior in nutrient-dependent reproductively fit individuals

  1. Global assessment of nutrient loads to the world's largest lakes

    NASA Astrophysics Data System (ADS)

    Fink, Gabriel; Reder, Klara; Malsy, Marcus; Eisner, Stephanie; Flörke, Martina

    2015-04-01

    Lakes are essential resources of drinking water for a large part of mankind. Even so, most of the industrial and domestic waste water is discharged - often untreated - into rivers and streams that are finally the tributaries of these important freshwater bodies. Additionally, diffuse nutrient sources such as fertilizer and atmospheric deposition exacerbate existing algal blooms and low oxygen concentrations in rivers, lakes, and reservoirs. In this tense atmosphere of competing water uses, it is necessary to analyze all sources of pollution as well as their total contributions in order to protect these water bodies against deterioration. Finally, this is a general and urgently needed basis for developing recommendations for involved stakeholders and decision makers. Therefore, the project eartH2Observe, initiated and financed by the European Commission, creates the necessary and underlying quantitative and qualitative hydrological and water use data. In this context, information for global as well as for regional water resource assessments is being prepared based on new earth observations and an ensemble of global hydrological models. As a member of this ensemble, WaterGAP3 provides global estimates of lake water quality relevant parameters on a 5 arc minutes grid, namely total phosphorus and total nitrogen. These nutrient loads to lakes from different sources such as industrial fertilizer, organic fertilizer, domestic loads, atmospheric deposition, and urban surface runoff are estimated for the period 1990 to 2010 in a monthly time step. Whereas nutrient loads and their changes into numerous lakes worldwide are calculated, a special focus is set on nutrient loads into the large and shallow Lake Peipus, which is located between Estonia and Russia and subject to blooms of harmful cyanobacteria. We present estimates, trends, as well as sources of present nutrient loads (TN and TP) to the world's largest lakes with detailed insights to the Lake Peipus situation

  2. Predator-Driven Nutrient Recycling in California Stream Ecosystems

    PubMed Central

    Munshaw, Robin G.; Palen, Wendy J.; Courcelles, Danielle M.; Finlay, Jacques C.

    2013-01-01

    Nutrient recycling by consumers in streams can influence ecosystem nutrient availability and the assemblage and growth of photoautotrophs. Stream fishes can play a large role in nutrient recycling, but contributions by other vertebrates to overall recycling rates remain poorly studied. In tributaries of the Pacific Northwest, coastal giant salamanders (Dicamptodon tenebrosus) occur at high densities alongside steelhead trout (Oncorhynchus mykiss) and are top aquatic predators. We surveyed the density and body size distributions of D. tenebrosus and O. mykiss in a California tributary stream, combined with a field study to determine mass-specific excretion rates of ammonium (N) and total dissolved phosphorus (P) for D. tenebrosus. We estimated O. mykiss excretion rates (N, P) by bioenergetics using field-collected data on the nutrient composition of O. mykiss diets from the same system. Despite lower abundance, D. tenebrosus biomass was 2.5 times higher than O. mykiss. Mass-specific excretion summed over 170 m of stream revealed that O. mykiss recycle 1.7 times more N, and 1.2 times more P than D. tenebrosus, and had a higher N:P ratio (8.7) than that of D. tenebrosus (6.0), or the two species combined (7.5). Through simulated trade-offs in biomass, we estimate that shifts from salamander biomass toward fish biomass have the potential to ease nutrient limitation in forested tributary streams. These results suggest that natural and anthropogenic heterogeneity in the relative abundance of these vertebrates and variation in the uptake rates across river networks can affect broad-scale patterns of nutrient limitation. PMID:23520520

  3. Relating watershed nutrient loads to satellite derived estuarine water quality

    NASA Astrophysics Data System (ADS)

    Lehrter, J. C.; Le, C.

    2015-12-01

    Nutrient enhanced phytoplankton production is a cause of degraded estuarine water quality. Yet, relationships between watershed nutrient loads and the spatial and temporal scales of phytoplankton blooms and subsequent water quality impairments remain unquantified for most systems. This is partially due to a lack of observations. In many systems, satellite remote sensing of water quality variables may be used to supplement limited field observations and improve understanding of linkages to nutrients. Here, we present the results from a field and satellite ocean color study that quantitatively links nutrients to variations in estuarine water quality endpoints. The study was conducted in Pensacola Bay, Florida, an estuary in the northern Gulf of Mexico that is impacted by watershed nutrients. We developed new empirical band ratio algorithms to retrieve phytoplankton biomass as chlorophyll a (chla), colored dissolved organic matter (CDOM), and suspended particulate matter (SPM) from the MEdium Resolution Imaging Spectrometer (MERIS). MERIS had suitable spatial resolution (300-m) for the scale of Pensacola Bay (area = 370 km2, mean depth = 3.4 m) and a spectral band centered at wavelength 709 nm that was used to minimize the effect of organic matter on chla retrieval. The algorithms were applied to daily MERIS remote sensing reflectance (level 2) data acquired from 2003 to 2011 to calculate nine-year time-series of mean monthly chla, CDOM, and SPM concentrations. The MERIS derived time-series were then analyzed for statistical relations with time-series of mean monthly river discharge and river loads of nitrogen, phosphorus, dissolved organic carbon, and SPM. Regression analyses revealed significant relationships between river loads and MERIS water quality variables. The simple regression models provide quantitative predictions about how much chla, CDOM, and SPM concentrations in Pensacola Bay will increase with increased river loading, which is necessary information

  4. Through form to function: root hair development and nutrient uptake

    NASA Technical Reports Server (NTRS)

    Gilroy, S.; Jones, D. L.

    2000-01-01

    Root hairs project from the surface of the root to aid nutrient and water uptake and to anchor the plant in the soil. Their formation involves the precise control of cell fate and localized cell growth. We are now beginning to unravel the complexities of the molecular interactions that underlie this developmental regulation. In addition, after years of speculation, nutrient transport by root hairs has been demonstrated clearly at the physiological and molecular level, with evidence for root hairs being intense sites of H(+)-ATPase activity and involved in the uptake of Ca(2+), K(+), NH(4)(+), NO(3)(-), Mn(2+), Zn(2+), Cl(-) and H(2)PO(4)(-).

  5. Nutrient resources for crop production in the tropics

    PubMed Central

    Vlek, P. L. G.; Kühne, R. F.; Denich, M.

    1997-01-01

    For the foreseeable future a majority of the population, and almost all the mal- and under-nourished, will continue to be found in the tropics and subtropics. Food security in these parts of the world will have to be met largely from local resources. The productivity of the land is to a large extent determined by the fertlity of the soil, which in turn is mostly determined by its organic matter content and stored nutrients. Soil organic matter is readily lost when organic matter inputs are reduced upon cultivation and more so upon intensification. The concomitant loss of topsoil and possible exposure of subsoil acidity may cause further soil degradation.
    Plant nutrients to replenish what is yearly taken from the soil to meet the demands for food and fibre amount to 230 million tonnes (Mt). Current fertilizer consumption stands at about 130 Mt of N, P2O5,and K2O, supplemented by an estimated 90 Mt of N from biological nitrogen fixation worldwide. Although 80 per cent of the population lives in the developing world, only half the world's fertilizer is consumed there. Yet, as much as 50% of the increase in agricultural productivity in the developing world is due to the adoption of fertilizers. World population growth will cause a doubling in these nutrients requirements for the developing world by 2020, which, in the likely case of inadequate production, will need to be met from soil reserves. Because expansion of the cultivable land area is reaching its limits, the reliance on nutrient inputs and their efficient use is bound to grow.
    With current urban expansion, nutrients in harvested products are increasingly lost from the rural environment as a whole. Estimates of soil nutrient depletion rates for sub-Saharan Africa (SSA) are alarmingly high. The situation may be more favourable in Latin America and Asia where fertilizer inputs are tenfold those of SSA. Closing the nutrient cycle at a community level in rural areas may be tedious; on an inter-regional level

  6. Mathematical modelling of plant water and nutrient uptake

    NASA Astrophysics Data System (ADS)

    Roose, Tiina

    2010-05-01

    In this presentation I will describe a model of plant water and nutrient uptake and how to translate this model and experimental data from the single root scale to the root branching structure scale. The model starts at the single root scale and describes the water and nutrient movement in the soil using Richards' equation (water uptake) and diffusion-convection equation (nutrient uptake). The water and nutrient uptake in the single root scale model is represented by boundary conditions. In the case of nutrient uptake this has the form of a non-linear Michaelis-Menten uptake law and in the case of water this is given by a soil-xylem pressure difference boundary condition. The flow of water in the xylem is modeled as Poiseuille flow. We solve the single root scale models using the analytic approximate technique of asymptotic expansions similar to Oseen expansions known from fluid dynamics. We will then discuss how to use the analytic expression to estimate the water and nutrient uptake by growing root branching systems. We model the growth of the root system using a dynamic population model to describe the branching and elongation of roots in the branching system. This root branching population model results in a hyperbolic equation similar to age dependent population models and it can be solved fully analytically using the method of characteristics. Thus we have a fully analytic description of the root branching system evolution. We use this branching model to estimate the nutrient uptake in a scenario when the competition between subbranches is small, i.e., as it is in the case of phosphate, potassium and arsenic. We compare our approximate analytic model to a full 3d simulation of the root system phosphate uptake and find that the analytic model almost perfectly reproduces the 3d numerical model. In addition the analytic model can be included in larger field/catchment/climate scale models something which is not practically possible with the numerical simulations

  7. Nutrients for prevention and treatment of mental health disorders.

    PubMed

    Akhondzadeh, Shahin; Gerbarg, Patricia L; Brown, Richard P

    2013-03-01

    The choice of nutrients for review is based on clinical evidence of efficacy in neuropsychiatric disorders and biochemical effects that are neuroprotective or reparative. Vitamins, minerals, amino acids, and metabolites have been shown to augment antidepressants, improve symptoms in anxiety disorders, depression, neurodegenerative diseases, brain injury, ADHD, and schizophrenia, and to reduce medication side effects. Detection and correction of vitamin and mineral deficiencies can be essential for recovery. Generally low in adverse effects when taken in therapeutic doses, nutrients can be combined for greater benefits. Further studies are warranted to validate these promising treatments. PMID:23538074

  8. Defining powerhouse fruits and vegetables: a nutrient density approach.

    PubMed

    Di Noia, Jennifer

    2014-06-05

    National nutrition guidelines emphasize consumption of powerhouse fruits and vegetables (PFV), foods most strongly associated with reduced chronic disease risk; yet efforts to define PFV are lacking. This study developed and validated a classification scheme defining PFV as foods providing, on average, 10% or more daily value per 100 kcal of 17 qualifying nutrients. Of 47 foods studied, 41 satisfied the powerhouse criterion and were more nutrient-dense than were non-PFV, providing preliminary evidence of the validity of the classification scheme. The proposed classification scheme is offered as a tool for nutrition education and dietary guidance.

  9. Carbon storage in seagrass soils: long-term nutrient history exceeds the effects of near-term nutrient enrichment

    NASA Astrophysics Data System (ADS)

    Armitage, A. R.; Fourqurean, J. W.

    2015-10-01

    The carbon sequestration potential in coastal soils is linked to aboveground and belowground plant productivity and biomass, which in turn, is directly and indirectly influenced by nutrient input. We evaluated the influence of long-term and near-term nutrient input on aboveground and belowground carbon accumulation in seagrass beds, using a nutrient enrichment (nitrogen and phosphorus) experiment embedded within a naturally occurring, long-term gradient of phosphorus availability within Florida Bay (USA). We measured organic carbon stocks in soils and above- and belowground seagrass biomass after 17 months of experimental nutrient addition. At the nutrient-limited sites, phosphorus addition increased the carbon stock in aboveground seagrass biomass by more than 300 %; belowground seagrass carbon stock increased by 50-100 %. Soil carbon content slightly decreased (~ 10 %) in response to phosphorus addition. There was a strong but non-linear relationship between soil carbon and Thalassia testudinum leaf nitrogen: phosphorus (N : P) or belowground seagrass carbon stock. When seagrass leaf N : P exceeded a threshold of 75 : 1, or when belowground seagrass carbon stock was less than 100 g m-2, there was less than 3 % organic carbon in the sediment. Despite the marked difference in soil carbon between phosphorus-limited and phosphorus-replete areas of Florida Bay, all areas of the bay had relatively high soil carbon stocks near or above the global median of 1.8 % organic carbon. The relatively high carbon content in the soils indicates that seagrass beds have extremely high carbon storage potential, even in nutrient-limited areas with low biomass or productivity.

  10. Carbon storage in seagrass soils: long-term nutrient history exceeds the effects of near-term nutrient enrichment

    NASA Astrophysics Data System (ADS)

    Armitage, A. R.; Fourqurean, J. W.

    2016-01-01

    The carbon sequestration potential in coastal soils is linked to aboveground and belowground plant productivity and biomass, which in turn, is directly and indirectly influenced by nutrient input. We evaluated the influence of long-term and near-term nutrient input on aboveground and belowground carbon accumulation in seagrass beds, using a nutrient enrichment (nitrogen and phosphorus) experiment embedded within a naturally occurring, long-term gradient of phosphorus availability within Florida Bay (USA). We measured organic carbon stocks in soils and above- and belowground seagrass biomass after 17 months of experimental nutrient addition. At the nutrient-limited sites, phosphorus addition increased the carbon stock in aboveground seagrass biomass by more than 300 %; belowground seagrass carbon stock increased by 50-100 %. Soil carbon content slightly decreased ( ˜ 10 %) in response to phosphorus addition. There was a strong but non-linear relationship between soil carbon and Thalassia testudinum leaf nitrogen : phosphorus (N : P) or belowground seagrass carbon stock. When seagrass leaf N : P exceeded an approximate threshold of 75 : 1, or when belowground seagrass carbon stock was less than 100 g m-2, there was less than 3 % organic carbon in the sediment. Despite the marked difference in soil carbon between phosphorus-limited and phosphorus-replete areas of Florida Bay, all areas of the bay had relatively high soil carbon stocks near or above the global median of 1.8 % organic carbon. The relatively high carbon content in the soils indicates that seagrass beds have extremely high carbon storage potential, even in nutrient-limited areas with low biomass or productivity.

  11. A new insight into root responses to external cues: Paradigm shift in nutrient sensing

    PubMed Central

    Bhardwaj, Deepak; Medici, Anna; Gojon, Alain; Lacombe, Benoît; Tuteja, Narendra

    2015-01-01

    Higher plants are sessile and their growth relies on nutrients present in the soil. The acquisition of nutrients is challenging for plants. Phosphate and nitrate sensing and signaling cascades play significant role during adverse conditions of nutrient unavailability. Therefore, it is important to dissect the mechanism by which plant roots acquire nutrients from the soil. Root system architecture (RSA) exhibits extensive developmental flexibility and changes during nutrient stress conditions. Growth of root system in response to external concentration of nutrients is a joint operation of sensor or receptor proteins along with several other cytoplasmic accessory proteins. After nutrient sensing, sensor proteins start the cellular relay involving transcription factors, kinases, ubiquitin ligases and miRNA. The complexity of nutrient sensing is still nebulous and many new players need to be better studied. This review presents a survey of recent paradigm shift in the advancements in nutrient sensing in relation to plant roots. PMID:26146897

  12. Proximate versus ultimate limiting nutrients in the Mississippi River Plume and Implications for Hypoxia Reductions through Nutrient Management

    NASA Astrophysics Data System (ADS)

    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

  13. Role of nutrient cycling and herbivory in regulating periphyton communities in laboratory streams

    SciTech Connect

    Mulholland, P.J.; Steinman, A.D.; Palumbo, A.V.; Elwood, J.W. ); Kirschtel, D.B. )

    1992-01-01

    In this study the authors examined the role of nutrient cycling and herbivory in regulating stream periphyton communities. Population, community, and ecosystem-level properties were studied in laboratory stream channels that had nutrient inputs reduced compared to channels where ambient nutrient levels were maintained. They reduced nutrient inputs in four of eight channels by recirculating 90% of the flow, whereas the other four channels received once-through flow of spring water. They examined the interaction between herbivory and nutrients by varying the number of snails (Elimia clavaeformis) among streams with different nutrient input regimes. Reduction in nutrient input via recirculation resulted in lower concentrations of nutrients in the water but did not result in significant differences in biomass, carbon fixation, or algal taxonomic composition. However, herbivory had large effects on these characteristics by reducing biomass and areal rates of carbon fixation and simplifying periphyton taxonomy and physiognomy. Lower rates of nutrient input significantly affected characteristics associated with nutrient cycling. Streams with reduced nutrient inputs had lower periphyton nutrient contents, higher ratios of total:net uptake of P from water, and higher rates of phosphatase activity than streams with ambient nutrient inputs. However, the effects of reduced nutrient input on cycling characteristics were reduced or eliminated by intense herbivory.

  14. Leonardo da Vinci and the Downburst.

    NASA Astrophysics Data System (ADS)

    Gedzelman, Stanley David

    1990-05-01

    Evidence from the drawings, experiments, and writings of Leonardo da Vinci are presented to demonstrate that da Vinci recognized and, possibly, discovered the downburst and understood its associated airflow. Other early references to vortex flows resembling downbursts are mentioned.

  15. Exploring the Sulfur Nutrient Cycle Using the Winogradsky Column

    ERIC Educational Resources Information Center

    Rogan, Brian; Lemke, Michael; Levandowsky, Michael; Gorrell, Thomas

    2005-01-01

    The Winogradsky column demonstrates how the metabolic diversity of prokaryotes transforms sulfur to different forms with varying redox states and hence, supplies nutrients and/or energy to the organism. The Winogardsky column is an excellent way to show that not all bacteria are pathogens and they have an important role in the geochemical cycling…

  16. Nerveless and gutsy: intestinal nutrient sensing from invertebrates to humans.

    PubMed

    Miguel-Aliaga, Irene

    2012-08-01

    The increasingly recognized role of gastrointestinal signals in the regulation of food intake, insulin production and peripheral nutrient storage has prompted a surge of interest in studying how the gastrointestinal tract senses and responds to nutritional information. Identification of metabolically important intestinal nutrient sensors could provide potential new drug targets for the treatment of diabetes, obesity and gastrointestinal disorders. From a more fundamental perspective, the study of intestinal chemosensation is revealing novel, non-neuronal modes of communication involving differentiated epithelial cells. It is also identifying signalling mechanisms downstream of not only canonical receptors but also nutrient transporters, thereby supporting a chemosensory role for "transceptors" in the intestine. This review describes known and proposed mechanisms of intestinal carbohydrate, protein and lipid sensing, best characterized in mammalian systems. It also highlights the potential of invertebrate model systems such as C. elegans and Drosophila melanogaster by summarizing known examples of molecular evolutionary conservation. Recently developed genetic tools in Drosophila, an emerging model system for the study of physiology and metabolism, allow the temporal, spatial and high-throughput manipulation of putative intestinal sensors. Hence, fruit flies may prove particularly suited to the study of the link between intestinal nutrient sensing and metabolic homeostasis. PMID:22248674

  17. Measuring Nitrification: A Laboratory Approach to Nutrient Cycling.

    ERIC Educational Resources Information Center

    Hicks, David J.

    1990-01-01

    Presented is an approach to the study of nutrient cycling in the school laboratory. Discussed are obtaining, processing, and incubating samples; extraction of ions from soil; procedures for nitrate and ammonium analysis; data analysis; an example of results; and other aspects of the nitrogen cycle. (CW)

  18. Nutrient Losses from Row Crop Agriculture in Indiana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nutrient losses from agriculture in the Midwestern United States have been identified as contributing to water quality problems such as hypoxia in the Gulf of Mexico, and eutrophication in the great lakes. Fields and catchments in the Cedar Creek sub-watershed of the St. Joseph River basin were mon...

  19. Radiation Preservation of Foods and Its Effect on Nutrients

    ERIC Educational Resources Information Center

    Josephson, Edward S.; Thomas, Miriam H.

    1970-01-01

    Presents a discussion of (1) some possible applications of ionizing radiation to the treatment and preservation of food and (2) the effects of irradiation on nutrients such as proteins, fats, oils, carbohydrates and vitamins. The authors suggest that the irradiation process has great potential in food technology. Bibliography. (LC)

  20. Phycoremediation: key issues for cost-effective nutrient removal processes.

    PubMed

    Olguín, Eugenia J

    2003-12-01

    Phycoremediation applied to the removal of nutrients from animal wastewater and other high organic content wastewater is a field with a great potential and demand considering that surface and underground water bodies in several regions of the world are suffering of eutrophication. However, the development of more efficient nutrient removal algal systems requires further research in key areas. Algae growth rate controls directly and indirectly the nitrogen and phosphorus removal efficiency. Thus, maximum algae productivity is required for effective nutrient removal and must be considered as a key area of research. Likewise, low harvesting costs are also required for a cost-effective nutrient removal system. The use of filamentous microalgae with a high autoflocculation capacity and the use of immobilized cells have been investigated in this respect. Another key area of research is the use of algae strains with special attributes such as tolerance to extreme temperature, chemical composition with predominance of high added value products, a quick sedimentation behavior, or a capacity for growing mixotrophically. Finally, to combine most of the achievements from key areas and to design integrated recycling systems (IRS) should be an ultimate and rewarding goal. PMID:14623045

  1. Characterization of heat transfer in nutrient materials, part 1

    NASA Technical Reports Server (NTRS)

    Cox, J. E.; Bannerot, R. B.; Chen, C. K.; Witte, L. C.

    1973-01-01

    The principles involved in food heating are discussed. The food heating system for Skylab is described. Thermal models of nutrient materials are analyzed including models in zero-g and low pressure conditions. Results are presented of parametric studies to establish the effect of individual parameters on the thermal response of the system.

  2. Farmed Fish: A source of lipid soluble nutrients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The consumption of seafood (fish, molluscs, crustaceans) is associated with a number of positive health outcomes as a result of nutrient content (e,g, protein, n3 fatty acids, vitamin D). Aquacultural “farmed” sources of marine and freshwater seafood total nearly 50% of total seafood production. Gi...

  3. Temporal Changes in the Spatial Variability of Soil Nutrients

    SciTech Connect

    R. L. Hoskinson; J. R. Hess; R. S. Alessi

    1999-07-01

    This paper reports the temporal changes in the spatial variability of soil nutrient concentrations across a field during the growing season, over a four-year period. This study is part of the Site-Specific Technologies for Agriculture (SST4Ag) precision farming research project at the INEEL. Uniform fertilization did not produce a uniform increase in fertility. During the growing season, several of the nutrients and micronutrients showed increases in concentration although no additional fertilization had occurred. Potato plant uptake did not explain all of these changes. Some soil micronutrient concentrations increased above levels considered detrimental to potatoes, but the plants did not show the effects in reduced yield. All the nutrients measured changed between the last sampling in the fall and the first sampling the next spring prior to fertilization. The soil microbial community may play a major role in the temporal changes in the spatial variability of soil nutrient concentrations. These temporal changes suggest potential impact when determining fertilizer recommendations, and when evaluating the results of spatially varying fertilizer application.

  4. Water, weed, and nutrient management practices in organic blackberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of our study is to investigate the effects of organic management on plant and soil water and nutrient relations, plant growth, yield, and fruit quality in an organic trailing blackberry production system. Treatments include: cultivar ('Marion' and 'Black Diamond'); irrigation (post-harve...

  5. Plant Leachate Nutrient Recovery with Biological, Thermal, and Photocatalytic Pretreatments

    NASA Technical Reports Server (NTRS)

    Wong, Les

    2015-01-01

    Plants are ideal for long term space travel: provide essential resources - oxygen, water, food; Water-soaked plants expel soluble nutrients in a leachate solution - toxins and wastes are also expelled and inhibit growth; biological, thermal, photocatalytic coupled with an acid digestion treatment will hopefully maximize recovery and remove wastes

  6. Genotypic response to multiple abiotic stresses: Functional relationships among nutrients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Macro- and micro-nutrients estimated in leaves, stems and seed of eleven genotypes of five physiologically diverse crop species (chickpeas, corn, safflower, soybean, and wheat, respectively producing protein, carbohydrates, oil, protein-oil, and carbohydrates-protein, as main seed storage macromolec...

  7. Herbivores and nutrients control grassland plant diversity via light limitation.

    SciTech Connect

    Borer, Elizabeth T.; et al, et al

    2014-01-01

    Human alterations to nutrient cycles1,2 and herbivore communities3–7 are affecting global biodiversity dramatically2. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems8,9. Here we use experimental data spanning a globally relevant range of conditions to test the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory. This experiment, replicated in 40 grasslands on 6 continents, demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant diversity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate. Nutrient addition consistently reduced local diversity through light limitation, and herbivory rescued diversity at sites where it alleviated light limitation. Thus, species loss from anthropogenic eutrophication can be ameliorated in grasslands where herbivory increases ground-level light.

  8. Nutrient and food intakes differ among Latina subgroups during pregnancy

    PubMed Central

    Hromi-Fiedler, Amber; Bermúdez-Millán, Angela; Segura-Pérez, Sofia; Pérez-Escamilla, Rafael

    2011-01-01

    Objective To document nutrient and food group serving intakes from food sources among Latina subgroups living in the same geographical area. Design A cross-sectional study. Nutrient and food group serving intakes were assessed by means of a 24 h recall administered immediately after a prenatal survey. Setting Hartford, CT, USA. Subjects A total of 233 low-income pregnant Latinas. For analyses, Latinas were classified into two groups on the basis of self-reported ethnic identity: Puerto Ricans and non-Puerto Rican Latinas. Results Puerto Rican Latinas were more likely than non-Puerto Rican Latinas to be more acculturated and to consume foods (i.e. processed meat, cheese, soft drinks) and higher levels of nutrients (i.e. fat, SFA, MUFA, trans fatty acids) that have been implicated in the development of chronic diseases. By contrast, non-Puerto Rican Latinas were more likely to consume foods (i.e. fruits, dark green/yellow vegetables, tomatoes, non-starchy vegetables) and higher levels of nutrients (i.e. fibre, vegetable protein, folate, β-carotene) that promote health when compared with Puerto Rican Latinas. Conclusions Findings suggest that acculturation may play a role in dietary intake. Clinicians and dietitians need to be aware of these differences to encourage healthy eating patterns among more acculturated pregnant Latina clients. PMID:21729472

  9. Nutrients and the Great Lakes Nearshore, Circa 2002-2007

    EPA Science Inventory

    Nearshore nutrient impressions were largely limited to observations of local spatial trends from a few site-specific studies and some temporal trends at a set of Canadian water intake locations (later summarized in Nicholls et al. 1999). Lacking a systematic information base fo...

  10. Prehistoric agricultural depletion of soil nutrients in Hawai'i

    PubMed Central

    Hartshorn, A. S.; Chadwick, O. A.; Vitousek, P. M.; Kirch, P. V.

    2006-01-01

    We investigated the fate of soil nutrients after centuries of indigenous dryland agriculture in Hawai‘i using a coupled geochemical and archaeological approach. Beginning ≈500 years ago, farmers began growing dryland taro and sweet potato on the leeward slopes of East Maui. Their digging sticks pierced a subsurface layer of cinders, enhancing crop access to the soil water stored below the intact cinders. Cultivation also catalyzed nutrient losses, directly by facilitating leaching of mobile nutrients after disturbing a stratigraphic barrier to vertical water movement, and indirectly by increasing mineral weathering and subsequent uptake and harvest. As a result, centuries of cultivation lowered volumetric total calcium, magnesium, sodium, potassium, and phosphorus content by 49%, 28%, 75%, 37%, and 32%, respectively. In the absence of written records, we used the difference in soil phosphorus to estimate that prehistoric yields were sufficient to meet local demand over very long time frames, but the associated acceleration of nutrient losses could have compromised subsequent yields. PMID:16832047

  11. 21 CFR 101.69 - Petitions for nutrient content claims.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Section 101.69 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION FOOD LABELING Specific Requirements for Nutrient Content Claims § 101... Nutrition for details. If any part of the material submitted is in a foreign language, it shall...

  12. 21 CFR 101.69 - Petitions for nutrient content claims.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Section 101.69 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION FOOD LABELING Specific Requirements for Nutrient Content Claims § 101... Nutrition for details. If any part of the material submitted is in a foreign language, it shall...

  13. 21 CFR 101.69 - Petitions for nutrient content claims.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Section 101.69 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION FOOD LABELING Specific Requirements for Nutrient Content Claims § 101... Nutrition for details. If any part of the material submitted is in a foreign language, it shall...

  14. 21 CFR 101.69 - Petitions for nutrient content claims.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Section 101.69 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION FOOD LABELING Specific Requirements for Nutrient Content Claims § 101... Nutrition for details. If any part of the material submitted is in a foreign language, it shall...

  15. 21 CFR 101.69 - Petitions for nutrient content claims.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Section 101.69 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION FOOD LABELING Specific Requirements for Nutrient Content Claims § 101... Nutrition for details. If any part of the material submitted is in a foreign language, it shall...

  16. Medication-Nutrient Interactions and Individuals with Special Healthcare Needs

    ERIC Educational Resources Information Center

    Brizee, Lori S.

    2008-01-01

    Many children and adults with special healthcare needs receive one or more medications on a regular basis. Parents and healthcare professionals who care for these individuals should be aware of each medication and potential interactions with foods/nutrients. Those who require long term or multiple medications are at highest risk for drug-nutrient…

  17. A nutrient combination that can affect synapse formation.

    PubMed

    Wurtman, Richard J

    2014-04-01

    Brain neurons form synapses throughout the life span. This process is initiated by neuronal depolarization, however the numbers of synapses thus formed depend on brain levels of three key nutrients-uridine, the omega-3 fatty acid DHA, and choline. Given together, these nutrients accelerate formation of synaptic membrane, the major component of synapses. In infants, when synaptogenesis is maximal, relatively large amounts of all three nutrients are provided in bioavailable forms (e.g., uridine in the UMP of mothers' milk and infant formulas). However, in adults the uridine in foods, mostly present at RNA, is not bioavailable, and no food has ever been compelling demonstrated to elevate plasma uridine levels. Moreover, the quantities of DHA and choline in regular foods can be insufficient for raising their blood levels enough to promote optimal synaptogenesis. In Alzheimer's disease (AD) the need for extra quantities of the three nutrients is enhanced, both because their basal plasma levels may be subnormal (reflecting impaired hepatic synthesis), and because especially high brain levels are needed for correcting the disease-related deficiencies in synaptic membrane and synapses. PMID:24763080

  18. Nutrient analysis of the Beef Alternative Merchandising cuts.

    PubMed

    Desimone, T L; Acheson, R A; Woerner, D R; Engle, T E; Douglass, L W; Belk, K E

    2013-03-01

    The objective of this study was to generate raw and cooked nutrient composition data to identify Quality Grade differences in proximate values for eight Beef Alternative Merchandising (BAM) cuts. The data generated will be used to update the nutrient data in the USDA National Nutrient Database for Standard Reference (SR). Beef Rib, Oven-Prepared, Beef Loin, Strip Loin, and Beef Loin, Top Sirloin Butt subprimals were collected from a total of 24 carcasses from four packing plants. The carcasses were a combination of USDA Yield Grades 2 (n=12) and 3 (n=12), USDA Quality Grades upper two-thirds Choice (n=8), low Choice (n=8), and Select (n=8), and two genders, steer (n=16) and heifer (n=8). After aging, subprimals were fabricated into the BAM cuts, dissected, and nutrient analysis was performed. Sample homogenates from each animal were homogenized and composited for analysis of the following: proximate analysis, long chain and trans-fatty acids, conjugated linoleic acid, total cholesterol, vitamin B-12, and selenium. This study identified seven BAM cuts from all three Quality Grades that qualify for USDA Lean; seven Select cuts that qualify for USDA Extra Lean; and three Select cuts that qualify for the American Heart Association's Heart Healthy Check.

  19. Nutrient losses from an irrigated watershed in southern Idaho

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water, sediment and nutrients flowing into and out of the 82,000 ha Twin Falls, ID irrigation tract were measured from 2005 to 2008. Approximately 80% of the water flowing into the watershed was irrigation water diverted from the Snake River. About 40% of the watershed inflow returned to the Snake R...

  20. Tillage and nutrient sources impact the productivity of eroded soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil degradation is a consequence of soil organic matter (SOM) losses due to soil disturbance, SOM decomposition, and soil erosion. Manure addition has been shown to enhance SOM, improve soil nutrient status, and increase soil productivity. Manure rates and degree of incorporation may also influenc...