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Sample records for modeling nutrient consumptions

  1. Modeling Nutrient Consumptions in Large Flow-Through Bioreactors for Tissue Engineering

    PubMed Central

    Devarapalli, Mamatha; Lawrence, Benjamin J.; Madihally, Sundararajan V.

    2009-01-01

    Flow-through bioreactors are utilized in tissue regeneration to ensure complete nutrient distribution and apply defined hydrodynamic stresses. The fundamental concepts in designing these bioreactors for regenerating large high aspect ratio tissues (large surface area relative to the thickness of the matrix such as skin, bladder, and cartilage) are not well defined. Further, tissue regeneration is a dynamic process where the porous characteristics change due to proliferation of cells, de novo deposition of matrix components, and degradation of the porous architecture. These changes affect the transport characteristics and there is an imminent need to understand the influence of these factors. Using computational fluid dynamic tools, changes in the pressure drop, shear stress distribution and nutrient consumption patterns during tissue regeneration were assessed in rectangular and circular reactors described by Lawrence et al (Lawrence et al. 2008). Further, six new designs with different inlet and outlet shapes were analyzed. The fluid flow was defined by the Brinkman equation on the porous regions using the pore characteristics of 85 μm and 120 pores/mm2. The minimum flow requirements to satisfy nutrient (oxygen and glucose) requirements for three different cell types (SMCs, chondrocytes, and hepatocytes) was evaluated using convective diffusion equation. For consumption reaction, the Michaelis-Menten rate law was used, with constants (km and vm values) extracted from literature. Simulations were performed by varying the flow rate as well as the cell number. One of the circular reactors with semicircular inlet and outlet shape decreased (i) non-uniformity in hydrodynamic stress within the porous structure and (ii) non-uniform nutrient distribution. All cell types showed increased consumption of oxygen than glucose. Hepatocytes needed a very high flow rate relative to other cell types. Increase in cell number suggested a need for increasing the flow in circular

  2. A novel coupled system of non-local integro-differential equations modelling Young's modulus evolution, nutrients' supply and consumption during bone fracture healing

    NASA Astrophysics Data System (ADS)

    Lu, Yanfei; Lekszycki, Tomasz

    2016-10-01

    During fracture healing, a series of complex coupled biological and mechanical phenomena occurs. They include: (i) growth and remodelling of bone, whose Young's modulus varies in space and time; (ii) nutrients' diffusion and consumption by living cells. In this paper, we newly propose to model these evolution phenomena. The considered features include: (i) a new constitutive equation for growth simulation involving the number of sensor cells; (ii) an improved equation for nutrient concentration accounting for the switch between Michaelis-Menten kinetics and linear consumption regime; (iii) a new constitutive equation for Young's modulus evolution accounting for its dependence on nutrient concentration and variable number of active cells. The effectiveness of the model and its predictive capability are qualitatively verified by numerical simulations (using COMSOL) describing the healing of bone in the presence of damaged tissue between fractured parts.

  3. Effect of nutrition education intervention based on Pender's Health Promotion Model in improving the frequency and nutrient intake of breakfast consumption among female Iranian students.

    PubMed

    Dehdari, Tahereh; Rahimi, Tahereh; Aryaeian, Naheed; Gohari, Mahmood Reza

    2014-03-01

    To determine the effectiveness of nutrition education intervention based on Pender's Health Promotion Model in improving the frequency and nutrient intake of breakfast consumption among female Iranian students. The quasi-experimental study based on Pender's Health Promotion Model was conducted during April-June 2011. Information (data) was collected by self-administered questionnaire. In addition, a 3 d breakfast record was analysed. P < 0·05 was considered significant. Two middle schools in average-income areas of Qom, Iran. One hundred female middle-school students. There was a significant reduction in immediate competing demands and preferences, perceived barriers and negative activity-related affect constructs in the experimental group after education compared with the control group. In addition, perceived benefit, perceived self-efficacy, positive activity-related affect, interpersonal influences, situational influences, commitment to a plan of action, frequency and intakes of macronutrients and most micronutrients of breakfast consumption were also significantly higher in the experimental group compared with the control group after the nutrition education intervention. Constructs of Pender's Health Promotion Model provide a suitable source for designing strategies and content of a nutrition education intervention for improving the frequency and nutrient intake of breakfast consumption among female students.

  4. 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

  5. Energy-consumption modelling

    SciTech Connect

    Reiter, E.R.

    1980-01-01

    A highly sophisticated and accurate approach is described to compute on an hourly or daily basis the energy consumption for space heating by individual buildings, urban sectors, and whole cities. The need for models and specifically weather-sensitive models, composite models, and space-heating models are discussed. Development of the Colorado State University Model, based on heat-transfer equations and on a heuristic, adaptive, self-organizing computation learning approach, is described. Results of modeling energy consumption by the city of Minneapolis and Cheyenne are given. Some data on energy consumption in individual buildings are included.

  6. Pulse consumption in Canadian adults influences nutrient intakes.

    PubMed

    Mudryj, Adriana N; Yu, Nancy; Hartman, Terryl J; Mitchell, Diane C; Lawrence, Frank R; Aukema, Harold M

    2012-08-01

    Pulses (dry beans, peas, lentils) are nutrient-dense foods that are recommended as good choices in either the vegetable or meat and alternative food groups in Canada's Food Guide. To examine the prevalence and the effect of pulse consumption on nutrient intake in Canadian adults ( ≥ 19 years), we analysed cross-sectional data (n 20,156) from the 2004 Canadian Community Health Survey, Cycle 2·2. Participants were divided into non-consumers and quartiles of pulse intake. Sample weights were applied and logistic regression analysis was used to explore the association of nutrient intakes and pulse consumption, with cultural background, sex, age and economic status included as covariates. On any given day, 13 % of Canadians consume pulses, with the highest consumption in the Asian population. The pulse intake of consumers in the highest quartile was 294 (se 40) g/d and, compared with non-consumers, these individuals had higher intakes of carbohydrate, fibre and protein. As well, the micronutrient intake of pulse consumers was enhanced, resulting in fewer individuals who were below the estimated average requirement for thiamin, vitamin B6, folate, Fe, Mg, P and Zn, compared with non-consumers. Although pulses are generally low in Na, its intake also was higher in pulse consumers. Among the higher quartiles of pulse consumers, fruit and vegetable intake was one serving higher. These data indicate that pulse consumption supports dietary advice that pulses be included in healthful diets. Further studies elucidating the sources of increased Na in pulse consumers will be necessary so that dietary advice to increase consumption of pulses will maximise their nutritional benefits.

  7. Association between Smoking Status and Food and Nutrient Consumption in Japanese: a Large-Scale Cross-Sectional Study.

    PubMed

    Endoh, Kaori; Kuriki, Kiyonori; Kasezawa, Nobuhiko; Tohyama, Kazushige; Goda, Toshinao

    2015-01-01

    In Japan, in comparison with the rest of the world the death rate of lung cancer is low although the smoking rate is relatively high. This is the so-called "Japanese smoking paradox". A healthy diet is proposed to attenuate the risk without quitting smoking. We here examined the relationships between smoking status (SS) and the consumption of food and nutrient in Japan. Totals of 5,587 men and 2,718 women were divided into three (non-smokers, smokers and heavy smokers) and two (non-smokers and smokers) groups, respectively, according to pack-year, which represents the amount of smoking over a long period. Food and nutrient consumption was estimated with a validated food frequency questionnaire. Using general linear models, food and nutrient consumption was estimated for each group in men and women, separately. In men, SS was positively related to consumption of rice, 3 alcoholic beverages, carbohydrate, alcohol and other 8 foods/nutrients (p<0.05 for all) and negatively to those of protein animal, fat, fatty acids, dietary fiber, isoflavones and 36 other foods/nutrients (p<0.05 for all). In women, SS was positively associated with intake of 13 foods/nutrients, while being negatively associated with those of rice, energy, dietary fiber, and 14 other foods/nutrients (p<0.05 for all). Our results support lower intake of vegetables and fruits rich in antioxidants, which are thought as preventive factors for many diseases, in smokers.

  8. Levels of nutrients in relation to fish consumption among older male anglers in Wisconsin

    PubMed Central

    Christensen, Krista Y.; Thompson, Brooke A.; Werner, Mark; Malecki, Kristen; Imm, Pamela; Anderson, Henry A.

    2016-01-01

    Fish are an important source of nutrients including omega-3 fatty acids, which may reduce risk of adverse health outcomes such as cardiovascular disease; however, fish may also contain significant amounts of environmental pollutants. The Wisconsin Departments of Health Services and Natural Resources developed a survey instrument, along with a strategy to collect human biological samples to assess the risks and benefits associated with long-term fish consumption among older male anglers in Wisconsin. The target population was men aged 50 years and older, who fish Wisconsin waters and live in the state of Wisconsin. Participants provided blood and hair samples and completed a detailed (paper) questionnaire, which included questions on basic demographics, health status, location of catch and species of fish caught/eaten, consumption of locally caught and commercially purchased fish, and awareness and source of information for local and statewide consumption guidelines. Biological samples were used to assess levels of docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), eicosapentaenoic acid (EPA); vitamin D; and selenium in blood. Quantile regression analysis was used to investigate the associations between biomarker levels and self-reported consumption of fish from the Great Lakes and other areas of concern, other locally caught fish, and commercially purchased fish (meals per year). Respondents were largely non-Hispanic white men in their 60’s with at least some college education, and about half were retired. Fish consumption was high (median of 54.5 meals per year), with most fish meals coming from locally-caught fish. Multivariate regression models showed that the effect of supplement use was much greater than that of fish consumption, on nutrient levels, although consumption of fish from the Great Lakes and areas of concern was significantly associated with higher levels of vitamin D even after controlling for supplement usage. PMID:26296180

  9. Are Breakfast Consumption Patterns Associated with Weight Status and Nutrient Adequacy in African-American Children?

    USDA-ARS?s Scientific Manuscript database

    The objective of the present study was to assess whether weight status, nutrient intake and dietary adequacy were associated with breakfast consumption patterns. A representative sample of the US population was used in a secondary analysis of nutrient intake/diet quality and weight status by breakfa...

  10. Multicontextual correlates of energy-dense, nutrient-poor snack food consumption by adolescents.

    PubMed

    Larson, Nicole; Miller, Jonathan M; Eisenberg, Marla E; Watts, Allison W; Story, Mary; Neumark-Sztainer, Dianne

    2017-05-01

    Frequent consumption of energy-dense, nutrient-poor snack foods is an eating behavior of public health concern. This study was designed to inform strategies for reducing adolescent intake of energy-dense snack foods by identifying individual and environmental influences. Surveys were completed in 2009-2010 by 2540 adolescents (54% females, mean age = 14.5 ± 2.0, 80% nonwhite) in Minneapolis-St. Paul, Minnesota schools. Daily servings of energy-dense snack food was assessed using a food frequency questionnaire that asked about consumption of 21 common snack food items, such as potato chips, cookies, and candy. Data representing characteristics of adolescents' environments were collected from parents/caregivers, friends, school personnel, Geographic Information System sources, and a content analysis of favorite television shows. Linear regression was used to examine relationships between each individual or environmental characteristic and snack food consumption in separate models and also to examine relationships in a model including all of the characteristics simultaneously. The factors found to be significantly associated with higher energy-dense snack food intake represented individual attitudes/behaviors (e.g., snacking while watching television) and characteristics of home/family (e.g., home unhealthy food availability), peer (friends' energy-dense snack food consumption), and school (e.g., student snack consumption norms) environments. In total, 25.5% of the variance in adolescents' energy-dense snack food consumption was explained when factors from within each context were examined together. The results suggest that the design of interventions targeting improvement in the dietary quality of adolescents' snack food choices should address relevant individual factors (e.g., eating while watching television) along with characteristics of their home/family (e.g., limiting the availability of unhealthy foods), peer (e.g., guiding the efforts of a peer leader in

  11. Breakfast consumption is positively associated with nutrient adequacy in Canadian children and adolescents.

    PubMed

    Barr, Susan I; DiFrancesco, Loretta; Fulgoni, Victor L

    2014-10-28

    Although breakfast is associated with more favourable nutrient intake profiles in children, limited data exist on the impact of breakfast on nutrient adequacy and the potential risk of excessive intakes. Accordingly, we assessed differences in nutrient intake and adequacy among breakfast non-consumers, consumers of breakfasts with ready-to-eat cereal (RTEC) and consumers of other types of breakfasts. We used cross-sectional data from 12,281 children and adolescents aged 4-18 years who took part in the nationally representative Canadian Community Health Survey, 2004. Mean nutrient intakes (obtained using a multiple-pass 24 h recall method) were compared among the breakfast groups using covariate-adjusted regression analysis. Usual nutrient intake distributions, generated using the National Cancer Institute method, were used to determine the prevalence of nutrient inadequacy or the potential risk of excessive intakes from food sources alone and from the combination of food plus supplements. Of these Canadian children, 10% were breakfast non-consumers, 33% were consumers of RTEC breakfasts and 57% were consumers of other types of breakfasts. Non-consumption of breakfast increased with age (4-8 years: 2%; 9-13 years: 9%; 14-18 years: 18%). Breakfast consumers had higher covariate-adjusted intakes of energy, many nutrients and fibre, and lower fat intakes. The prevalence of nutrient inadequacy for vitamin D, Ca, Fe and Mg (from food alone or from the combination of food plus supplements) was highest in breakfast non-consumers, intermediate in consumers of other types of breakfasts and lowest in consumers of RTEC breakfast. For vitamin A, P and Zn, breakfast non-consumers had a higher prevalence of nutrient inadequacy than both breakfast groups. The potential risk of excessive nutrient intakes was low in all groups. Efforts to encourage and maintain breakfast consumption in children and adolescents are warranted.

  12. Alcoholic Beverage Consumption, Nutrient Intakes, and Diet Quality in the US Adult Population, 1999-2006

    PubMed Central

    Breslow, Rosalind A.; Guenther, Patricia M.; Juan, Wenyen; Graubard, Barry I.

    2010-01-01

    Background Little is known about associations between alcoholic beverage consumption, nutrient intakes, and diet quality, although each has been independently associated with chronic disease outcomes. Objective This study examines cross-sectional relationships between alcoholic beverage consumption, nutrient intakes, and diet quality (Healthy Eating Index-2005 [HEI-2005] scores) in the US adult population. Methods Data were from four cycles of the National Health and Nutrition Examination Survey (1999-2006). Weighted multiple regression analyses, adjusted for age, race/ethnicity, education, smoking status, and body mass index included 8,155 men and 7,715 women aged ≥20 years who reported their past-year alcoholic beverage consumption and 24-hour dietary intake. Alcoholic beverage consumption was defined by drinking status (never, former, current drinker) and, among current drinkers, by drinking level (number of drinks per day, on average: men <1 to ≥5; women <1 to ≥3). Results Among men, there was no association between drinking status and intakes of energy, most nutrients, or total HEI-2005 score. Among women, former and current (compared to never) drinkers had significantly higher intakes of energy and several nutrients, and current drinkers had significantly lower total HEI-2005 scores (current drinkers 58.9; never drinkers 63.2). Among current drinkers of both sexes, as drinking level increased, intakes of energy and several nutrients significantly increased, whereas total HEI-2005 scores significantly decreased (from 55.9 to 41.5 in men, and from 59.5 to 51.8 in women). Conclusions Among men and women, increasing alcoholic beverage consumption was associated with a decline in total diet quality as measured by the HEI-2005, apparently due to higher energy intake from alcohol as well as other differences in food choices. Educational messages should focus on nutrition and chronic disease risk associated with high consumption of alcoholic beverages and poor

  13. Nutrient Intakes and Vegetable and White Potato Consumption by Children Aged 1 to 3 Years12

    PubMed Central

    Storey, Maureen L; Anderson, Patricia A

    2016-01-01

    In 2020, for the first time, the Dietary Guidelines for Americans will include recommendations for children from birth to age 24 mo. We examined average nutrient intakes as well as total vegetable and white potato (WP) consumption among children aged 1–3 y using day 1 dietary data from the NHANES 2009–2012 and the Food Patterns Equivalents Database 2009–2012. Appropriate survey weights were used to calculate average daily consumption of total vegetables and WPs, which included French-fried potatoes and chips, for boys and girls aged 1–3 y. We calculated mean intakes of selected nutrients of concern, including vitamin D, potassium, dietary fiber (DF), and calcium. We also examined intakes of selected nutrients by major food group. Average intakes of most nutrients, including calcium, by children aged 1–3 y exceeded Dietary Reference Intakes (DRIs). However, average intakes of potassium, DF, and vitamin D were 67%, 55%, and 49% of DRIs, respectively. Mean total vegetable intake was less than the recommendation of 1 cup/d. Boys and girls aged 1–3 y consumed an average of 0.58 cup equivalents of total vegetables on the day of the survey, which included 0.16 cups of WPs. Average vegetable consumption and mean intakes of potassium, DF, and vitamin D were far below recommendations. The consumption of all vegetables, particularly those that are excellent sources of potassium and DF, such as potatoes, should be encouraged. PMID:26773032

  14. Nutrient Intakes and Vegetable and White Potato Consumption by Children Aged 1 to 3 Years.

    PubMed

    Storey, Maureen L; Anderson, Patricia A

    2016-01-01

    In 2020, for the first time, the Dietary Guidelines for Americans will include recommendations for children from birth to age 24 mo. We examined average nutrient intakes as well as total vegetable and white potato (WP) consumption among children aged 1-3 y using day 1 dietary data from the NHANES 2009-2012 and the Food Patterns Equivalents Database 2009-2012. Appropriate survey weights were used to calculate average daily consumption of total vegetables and WPs, which included French-fried potatoes and chips, for boys and girls aged 1-3 y. We calculated mean intakes of selected nutrients of concern, including vitamin D, potassium, dietary fiber (DF), and calcium. We also examined intakes of selected nutrients by major food group. Average intakes of most nutrients, including calcium, by children aged 1-3 y exceeded Dietary Reference Intakes (DRIs). However, average intakes of potassium, DF, and vitamin D were 67%, 55%, and 49% of DRIs, respectively. Mean total vegetable intake was less than the recommendation of 1 cup/d. Boys and girls aged 1-3 y consumed an average of 0.58 cup equivalents of total vegetables on the day of the survey, which included 0.16 cups of WPs. Average vegetable consumption and mean intakes of potassium, DF, and vitamin D were far below recommendations. The consumption of all vegetables, particularly those that are excellent sources of potassium and DF, such as potatoes, should be encouraged. © 2016 American Society for Nutrition.

  15. Electric-field-enhanced nutrient consumption in dielectric biomaterials that contain anchorage-dependent cells.

    PubMed

    Belfiore, Laurence A; Floren, Michael L; Belfiore, Carol J

    2012-02-01

    This research contribution addresses electric-field stimulation of intra-tissue mass transfer and cell proliferation in viscoelastic biomaterials. The unsteady state reaction-diffusion equation is solved according to the von Kármán-Pohlhausen integral method of boundary layer analysis when nutrient consumption and tissue regeneration occur in response to harmonic electric potential differences across a parallel-plate capacitor in a dielectric-sandwich configuration. The partial differential mass balance with diffusion and electro-kinetic consumption contains the Damköhler (Λ(2)) and Deborah (De) numbers. Zero-field and electric-field-sensitive Damköhler numbers affect nutrient boundary layer growth. Diagonal elements of the 2nd-rank diffusion tensor are enhanced in the presence of weak electric fields, in agreement with the formalism of equilibrium and nonequilibrium thermodynamics. Induced dipole polarization density within viscoelastic biomaterials is calculated via the real and imaginary components of the complex dielectric constant, according to the Debye equation, to quantify electro-kinetic stimulation. Rates of nutrient consumption under zero-field conditions are described by third-order kinetics that include local mass densities of nutrients, oxygen, and attached cells. Thinner nutrient boundary layers are stabilized at shorter dimensionless diffusion times when the zero-field intra-tissue Damköhler number increases above its initial-condition-sensitive critical value [i.e., {Λ(2)(zero-field)}(critical)≥53, see Eq. (23)], such that the biomaterial core is starved of essential ingredients required for successful proliferation. When tissue regeneration occurs above the critical electric-field-sensitive intra-tissue Damköhler number, the electro-kinetic contribution to nutrient consumption cannot be neglected. The critical electric-field-sensitive intra-tissue Damköhler number is proportional to the Deborah number.

  16. Improved nutrient intake and diet quality with 100% fruit juice consumption in children: NHANES 2003-2006

    USDA-ARS?s Scientific Manuscript database

    Fruit juice (FJ) consumption has recently been viewed as a sweetened beverage with little regard to its nutrient contribution to the diet. NHANES, 2003–2006, data were used to examine the association of 100% FJ consumption, with nutrient intake and diet quality in children ages 2–5 y (n equals 1,665...

  17. Dynamic model of flexible phytoplankton nutrient uptake

    PubMed Central

    Bonachela, Juan A.; Raghib, Michael; Levin, Simon A.

    2011-01-01

    The metabolic machinery of marine microbes can be remarkably plastic, allowing organisms to persist under extreme nutrient limitation. With some exceptions, most theoretical approaches to nutrient uptake in phytoplankton are largely dominated by the classic Michaelis–Menten (MM) uptake functional form, whose constant parameters cannot account for the observed plasticity in the uptake apparatus. Following seminal ideas by earlier researchers, we propose a simple cell-level model based on a dynamic view of the uptake process whereby the cell can regulate the synthesis of uptake proteins in response to changes in both internal and external nutrient concentrations. In our flexible approach, the maximum uptake rate and nutrient affinity increase monotonically as the external nutrient concentration decreases. For low to medium nutrient availability, our model predicts uptake and growth rates larger than the classic MM counterparts, while matching the classic MM results for large nutrient concentrations. These results have important consequences for global coupled models of ocean circulation and biogeochemistry, which lack this regulatory mechanism and are thus likely to underestimate phytoplankton abundances and growth rates in oligotrophic regions of the ocean. PMID:22143781

  18. Stress-sensitive nutrient consumption via steady and non-reversing dynamic shear in continuous-flow rotational bioreactors.

    PubMed

    Belfiore, Laurence A; Bonani, Walter; Leoni, Matteo; Belfiore, Carol J

    2009-05-01

    Stress-sensitive biological response is simulated in a modified parallel-disk viscometer that implements steady and unidirectional dynamic shear under physiological conditions. Anchorage-dependent mammalian cells adhere to a protein coating on the surface of the rotating plate, receiving nutrients and oxygen from an aqueous medium that flows radially and tangentially, accompanied by transverse diffusion in the z-direction toward the active surface. This process is modeled as radial convection and axial diffusion with angular symmetry in cylindrical coordinates. The reaction/diffusion boundary condition on the surface of the rotating plate includes position-dependent stress-sensitive nutrient consumption via the zr- and zTheta-elements of the velocity gradient tensor at the cell/aqueous-medium interface. Linear transport laws in chemically reactive systems that obey Curie's theorem predict the existence of cross-phenomena between scalar reaction rates and the magnitude of the second-rank velocity gradient tensor, selecting only those elements of nabla v experienced by anchorage-dependent cells that are bound to protein-active sites. Stress sensitivity via the formalism of irreversible thermodynamics introduces a zeroth-order contribution to heterogeneous reaction rates that must be quenched when nutrients, oxygen, chemically anchored cells, or vacant active protein sites are not present on the surface of the rotating plate. Computer simulations of nutrient consumption profiles via simple nth-order kinetics (i.e., n=1,2) suggest that rotational bioreactor designs should consider stress-sensitivity when the shear-rate-based Damköhler number (i.e., ratio of the stress-dependent zeroth-order rate of nutrient consumption relative to the rate of nutrient diffusion toward active cells adhered to the rotating plate) is greater than approximately 25% of the stress-free Damköhler number. Rotational bioreactor simulations are presented for simple 1st-order, simple 2nd

  19. Household Food Expenditure Patterns, Food Nutrient Consumption and Nutritional Vulnerability in Nigeria: Implications for Policy.

    PubMed

    Akerele, Dare

    2015-01-01

    The study examined the patterns of food spending, food nutrient consumption, and nutrient deficiency profiles of households in Nigeria using a cross-sectional nationwide household survey data. Food nutrients were estimated from food expenditure data while the nutrient deficiency profiles were assessed adapting Foster et al. (1984) poverty index. The study established widespread nutritional deficiencies with low-income household cohorts bearing a greater burden of the deficiencies. Protein-protein deficiency appears to be much more prevalent in urban than rural areas. However, the deficiency of micro-nutrients seems to diffuse across urban-rural divides of the country with deficiency of calcium, vitamin A, and vitamin C appearing to be more pronounced in rural areas while phosphorous, vitamin B1, vitamin B2, and vitamin B3 deficiencies seem to be higher in urban settings. Pro-poor income growth strategies and sensitively guided urban-rural food and nutrition interventions are advocated for improved food consumption and nutritional deficiency reduction.

  20. Almond consumption is associated with better nutrient intake, nutrient adequacy, and diet quality in adults: National Health and Nutrition Examination Survey 2001-2010

    USDA-ARS?s Scientific Manuscript database

    The purpose of this study was to examine the association between almond consumption, the most widely consumed tree nut in the US, and nutrient intake, nutrient adequacy, diet quality, and weight/adiposity in adults. Data from adults (N=24,808), 19+ years, participating in the NHANES 2001-2010 were u...

  1. Frequent Canned Food Use is Positively Associated with Nutrient-Dense Food Group Consumption and Higher Nutrient Intakes in US Children and Adults.

    PubMed

    Comerford, Kevin B

    2015-07-09

    In addition to fresh foods, many canned foods also provide nutrient-dense dietary options, often at a lower price, with longer storage potential. The aim of this study was to compare nutrient-dense food group intake and nutrient intake between different levels of canned food consumption in the US. Consumption data were collected for this cross-sectional study from 9761 American canned food consumers (aged two years and older) from The NPD Group's National Eating Trends® (NET®) database during 2011-2013; and the data were assessed using The NPD Group's Nutrient Intake Database. Canned food consumers were placed into three groups: Frequent Can Users (≥6 canned items/week); n = 2584, Average Can Users (3-5 canned items/week); n = 4445, and Infrequent Can Users (≤2 canned items/week); n = 2732. The results provide evidence that Frequent Can Users consume more nutrient-dense food groups such as fruits, vegetables, dairy products, and protein-rich foods, and also have higher intakes of 17 essential nutrients including the shortfall nutrients-potassium, calcium and fiber-when compared to Infrequent Can Users. Therefore, in addition to fresh foods, diets higher in nutrient-dense canned food consumption can also offer dietary options which improve nutrient intakes and the overall diet quality of Americans.

  2. Frequent Canned Food Use is Positively Associated with Nutrient-Dense Food Group Consumption and Higher Nutrient Intakes in US Children and Adults

    PubMed Central

    Comerford, Kevin B.

    2015-01-01

    In addition to fresh foods, many canned foods also provide nutrient-dense dietary options, often at a lower price, with longer storage potential. The aim of this study was to compare nutrient-dense food group intake and nutrient intake between different levels of canned food consumption in the US. Consumption data were collected for this cross-sectional study from 9761 American canned food consumers (aged two years and older) from The NPD Group’s National Eating Trends® (NET®) database during 2011–2013; and the data were assessed using The NPD Group’s Nutrient Intake Database. Canned food consumers were placed into three groups: Frequent Can Users (≥6 canned items/week); n = 2584, Average Can Users (3–5 canned items/week); n = 4445, and Infrequent Can Users (≤2 canned items/week); n = 2732. The results provide evidence that Frequent Can Users consume more nutrient-dense food groups such as fruits, vegetables, dairy products, and protein-rich foods, and also have higher intakes of 17 essential nutrients including the shortfall nutrients—potassium, calcium and fiber—when compared to Infrequent Can Users. Therefore, in addition to fresh foods, diets higher in nutrient-dense canned food consumption can also offer dietary options which improve nutrient intakes and the overall diet quality of Americans. PMID:26184294

  3. Modelling of Usual Nutrient Intakes: Potential Impact of the Choices Programme on Nutrient Intakes in Young Dutch Adults

    PubMed Central

    Roodenburg, Annet J. C.; van Ballegooijen, Adriana J.; Dötsch-Klerk, Mariska; van der Voet, Hilko; Seidell, Jacob C.

    2013-01-01

    Introduction The Choices Programme is an internationally applicable nutrient profiling system with nutrition criteria for trans fatty acids (TFA), saturated fatty acids, sodium, added sugar and for some product groups energy and fibre. These criteria determine whether foods are eligible to carry a “healthier option” stamp. In this paper a nutrient intake modelling method is described to evaluate these nutritional criteria by investigating the potential effect on nutrient intakes. Methods Data were combined from the 2003 Dutch food consumption survey in young adults (aged 19–30) and the Dutch food composition table into the Monte Carlo Risk Assessment model. Three scenarios were calculated: the “actual intakes” (scenario 1) were compared to scenario 2, where all foods that did not comply were replaced by similar foods that did comply with the Choices criteria. Scenario 3 was the same as scenario 2 adjusted for the difference in energy density between the original and replacement food. Additional scenarios were calculated where snacks were not or partially replaced and stratified analyses for gender, age, Body Mass Index (BMI) and education. Results Calculated intake distributions showed that median energy intake was reduced by 16% by replacing normally consumed foods with Choices compliant foods. Intakes of nutrients with a maximal intake limit were also reduced (ranging from −23% for sodium and −62% for TFA). Effects on intakes of beneficial nutrients varied from an unintentional reduction in fat soluble vitamin intakes (−15 to −28%) to an increase of 28% for fibre and 17% calcium. Stratified analyses in this homogeneous study population showed only small differences across gender, age, BMI and education. Conclusions This intake modelling method showed that with consumption of Choices compliant foods, nutrient intakes shift towards population intake goals for the nutrients for which nutrition criteria were defined, while effects on beneficial

  4. Modelling consumer exposures to nutrients and additives in animal products.

    PubMed

    Tennant, D R; Bequet, P; Jans, D

    2009-01-01

    Current guidelines for assessing human exposures to nutrients and other substances used in animal feed are based on methods used for veterinary pharmaceuticals. These methods assume high-level daily consumption of animal products and do not take account of differences between species or between consuming humans. A more detailed dietary modelling approach is described, which takes these factors into account as well as high-level consumption by different age groups. The proposed approach is evaluated in three case studies, iodine, selenium and astaxanthin, which have previously undergone thorough evaluation by EU authorities. When applied in a tiered approach, the proposed model provides results that are consistent with previous assessments and with results obtained using other modelling techniques. The results indicate that the method has the potential to provide a conservative, reliable and flexible alternative to existing approaches to intake estimation.

  5. Modeling excessive nutrient loading in the environment.

    PubMed

    Reckhow, K H; Chapra, S C

    1999-01-01

    Models addressing excessive nutrient loading in the environment originated over 50 years ago with the simple nutrient concentration thresholds proposed by Sawyer (1947. Fertilization of lakes by agricultural and urban drainage. New Engl. Water Works Assoc. 61, 109-127). Since then, models have improved due to progress in modeling techniques and technology as well as enhancements in scientific knowledge. Several of these advances are examined here. Among the recent approaches in modeling techniques we review are error propagation, model confirmation, generalized sensitivity analysis, and Bayesian analysis. In the scientific arena and process characterization, we focus on advances in surface water modeling, discussing enhanced modeling of organic carbon, improved hydrodynamics, and refined characterization of sediment diagenesis. We conclude with some observations on future needs and anticipated developments.

  6. Efficiency of breakfast consumption patterns of ninth graders: nutrient-to-cost comparisons.

    PubMed

    Nicklas, Theresa A; McQuarrie, Allan; Fastnaught, Christine; O'Neil, Carol E

    2002-02-01

    To assess the efficiency of breakfast consumption patterns in terms of nutrient-to-cost comparisons. Twenty-four-hour dietary recalls were collected and food items named were priced (prices from local grocery stores and restaurants were averaged). Three breakfast consumption groups were identified: restaurant foods (fast foods), ready-to-eat (RTE) cereal, and other foods. Subjects consisted of 567 ninth-grade students (57% female, 86% white, mean age 14.8 years) in New Orleans, La. Analysis of variance techniques were used to test statistical significance for total nutrient intake levels, intake levels of nutrients per 1,000 kcal, and nutrient intake levels per dollar spent. Groupings were determined using the Duncan test or pairwise comparisons. Five percent of students ate a fast-food breakfast, 30% ate RTE cereal, and 65% ate other breakfasts. The mean cost of the breakfast meals was significantly (P<.0001) higher for the fast-food breakfast than for the RTE cereal breakfast and the other breakfast (fast>other=RTE). For every dollar spent, the RTE cereal and other breakfasts provided significantly more energy, carbohydrate, fiber, sugar, and protein than the fast-food breakfast. The other breakfast provided significantly (P<.001) more total and saturated fat per dollar than the fast-food or RTE cereal breakfasts. The RTE cereal breakfast provided significantly (P<.001) more, per dollar spent, of folic acid, iron, niacin, vitamins A and D, and zinc than the other 2 breakfast meals. The importance consumers place on taste, cost, and convenience continues to influence types of foods consumed. Yet, their food choices may not be as efficient in terms of the nutrients obtained per dollar spent. With the increasing demands being placed on families and the decreasing amount of time being spent on food preparation, nutrition education programs should continue to promote a higher level of efficient food choices.

  7. Food consumption and nutrient intake in Finnish 1-6-year-old children.

    PubMed

    Kyttälä, Pipsa; Erkkola, Maijaliisa; Kronberg-Kippilä, Carina; Tapanainen, Heli; Veijola, Riitta; Simell, Olli; Knip, Mikael; Virtanen, Suvi M

    2010-06-01

    To study food consumption and nutrient intake in Finnish children aged 1-6 years and to assess the effect of age and sex on food consumption and nutrient intake. Cross-sectional samples of children participating in the Type 1 Diabetes Prediction and Prevention (DIPP) birth cohort study in Finland. The study population comprised healthy children recruited in the nutrition study within the DIPP study in 1998-2003. Three-day food records (2535 in total) from 1-, 2-, 3-, 4- and 6-year-old children were kept between the years 2003 and 2005. The energy-adjusted consumption of fruits and berries, cereal products, infant formulas and meat dishes was higher and the consumption of vegetables, salads, breads, dairy products, fat spreads, drinks, sweets and sugar was lower among 1-year-old children than older age groups (P for all <0.05). The mean daily energy intake increased with age and was higher among boys than girls in all age groups, except among the 2-year-olds (P for all <0.05). The diet of the 2-6-year-old children contained too much saturated fat and sucrose, and too little PUFA compared with the current Nordic Nutrition Recommendations. The intakes of most vitamins and minerals met the recommendations. However, the intakes of vitamin D, E and iron fell below the recommended levels. The nutrient density of the diet decreased after the age of 1 year at the time that the children adapted to the regular family diet. In order to improve the diet of young children, it is essential to evaluate the diet of the whole family.

  8. Replacing American Breakfast Foods with Ready-To-Eat (RTE) Cereals Increases Consumption of Key Food Groups and Nutrients among US Children and Adults: Results of an NHANES Modeling Study.

    PubMed

    Rehm, Colin D; Drewnowski, Adam

    2017-09-13

    Replacing the typical American breakfast with ready-to-eat cereals (RTECs) may improve diet quality. Our goal was to assess the impact of RTECs on diet quality measures for different age groups, using substitution modeling. Dietary intakes came from the 2007-2010 National Health and Examination Surveys (NHANES; n = 18,112). All breakfast foods, excluding beverages, were replaced on a per calorie basis, with frequency-weighted and age/race specific RTECs. Model 1 replaced foods with RTECs alone; Model 2 replaced foods with RTECs and milk. Diet quality measures were based on desirable food groups and nutrients, Healthy Eating Index (HEI)-2010 scores, and estimated diet costs. Model 1 diets were significantly higher in whole grains (+84.6%), fiber (+14.3%), vitamin D (+14.0%), iron (+54.5%) and folic acid (+104.6%), as compared to observed diets. Model 2 diets were additionally higher in dairy (+15.8%), calcium (+11.3%) and potassium (+3.95%). In Model 1, added sugar increased (+5.0%), but solid fats declined (-10.9%). Energy from solid fats and added sugars declined (-3.2%) in both models. Model 2 offered higher diet quality (57.1 vs. 54.6, p-value < 0.01) at a lower cost ($6.70 vs. $6.92; p < 0.01), compared to observed diets. Substitution modeling of NHANES data can assess the nutritional and economic impact of dietary guidance.

  9. 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...

  10. 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...

  11. Common Indian spices: nutrient composition, consumption and contribution to dietary value.

    PubMed

    Uma Pradeep, K; Geervani, P; Eggum, B O

    1993-09-01

    Nutrient composition of eight commonly consumed spices of South India was analysed. Spices analysed were red chillies (Capsicum annum), black pepper (Piper nigrum), coriander seeds (Coriandrum sativum), cumin seeds (Cuminum cyminum), garlic (Allium sativum), asafoetida (Ferula foetida), dry ginger (Zingiber officinale) and ajowan (Carum copticum). The nutrients analysed were proximate principles, minerals, starch, sugars, dietary fibre components, tannins, phytic acid, enzyme inhibitors and amino acids. Dry ginger, ajowan and asafoetida had high calcium (1.0-1.5%) and iron (54-62 mg/100 g) levels. The tannin content of spices was also high (0.9-1.3% DM). Dietary fibre ranged from 14-53%. Spices had appreciable amounts of essential amino acids like lysine and threonine. A survey revealed the average per capita consumption of spices to be 9.54 g and at that level, the nutrient contribution from spices ranged from 1.2 to 7.9% of an average adult Indian male's requirement for different nutrients.

  12. Lactose intolerance and African Americans: implications for the consumption of appropriate intake levels of key nutrients.

    PubMed

    2009-10-01

    Lactose intolerance is a complex condition that is complicated by cultural beliefs and perceptions about the consumption of dairy products. These attitudes about dairy may contribute to inadequate intake of key nutrients that may impact conditions that contribute to health disparities in African Americans. While a complex health problem, lactose intolerance is easy to treat. However, no treatment can improve the body's ability to produce lactase. Yet, symptoms can be controlled through dietary strategies. This position paper emphasizes the importance of using patient and provider-level strategies in order to reduce the risks to the health of African Americans that may accrue as a result of dairy nutrient deficiency. Evaluation and assessment of interventions tested is critical so that evidence-based approaches to addressing dairy nutrient deficiency and lactose Intolerance can be created. Lastly, it is essential for physicians to communicate key messages to their patients. Since dairy nutrients address important health concerns, the amelioration of lactose intolerance is an investment in health. Lactose intolerance is common, is easy to treat, and can be managed. It is possible to consume dairy even in the face of a history of maldigestion or lactose intolerant issues. Gradually increasing lactose in the diet--drinking small milk portions with food, eating yogurt, and consuming cheese--are effective strategies for managing lactose intolerance and meeting optimal dairy needs.

  13. Dynamic shear-stress-enhanced rates of nutrient consumption in gas-liquid semi-continuous-flow suspensions

    NASA Astrophysics Data System (ADS)

    Belfiore, Laurence A.; Volpato, Fabio Z.; Paulino, Alexandre T.; Belfiore, Carol J.

    2011-12-01

    The primary objective of this investigation is to establish guidelines for generating significant mammalian cell density in suspension bioreactors when stress-sensitive kinetics enhance the rate of nutrient consumption. Ultra-low-frequency dynamic modulations of the impeller (i.e., 35104 Hz) introduce time-dependent oscillatory shear into this transient analysis of cell proliferation under semi-continuous creeping flow conditions. Greater nutrient consumption is predicted when the amplitude A of modulated impeller rotation increases, and stress-kinetic contributions to nutrient consumption rates increase linearly at higher modulation frequency via an application of fluctuation-dissipation response. Interphase mass transfer is required to replace dissolved oxygen as it is consumed by aerobic nutrient consumption in the liquid phase. The theory and predictions described herein could be important at small length scales in the creeping flow regime where viscous shear is significant at the interface between the nutrient medium and isolated cells in suspension. Two-dimensional flow around spherically shaped mammalian cells, suspended in a Newtonian culture medium, is analyzed to calculate the surface-averaged magnitude of the velocity gradient tensor and modify homogeneous rates of nutrient consumption that are stimulated by viscous shear, via the formalism of stress-kinetic reciprocal relations that obey Curie's theorem in non-equilibrium thermodynamics. Time constants for stress-free free and stress-sensitive stress nutrient consumption are defined and quantified to identify the threshold (i.e., stress,threshold) below which the effect of stress cannot be neglected in accurate predictions of bioreactor performance. Parametric studies reveal that the threshold time constant for stress-sensitive nutrient consumption stress,threshold decreases when the time constant for stress

  14. Factors influencing consumption of nutrient rich forest foods in rural Cameroon.

    PubMed

    Fungo, Robert; Muyonga, John H; Kabahenda, Margaret; Okia, Clement A; Snook, Laura

    2016-02-01

    Studies show that a number of forest foods consumed in Cameroon are highly nutritious and rich in health boosting bioactive compounds. This study assessed the knowledge and perceptions towards the nutritional and health promoting properties of forest foods among forest dependent communities. The relationship between knowledge, perceptions and socio-demographic attributes on consumption of forest foods was also determined. A total of 279 females in charge of decision making with respect to food preparation were randomly selected from 12 villages in southern and eastern Cameroon and interviewed using researcher administered questionnaires. Multivariate logistic regression analysis was used to identify the factors affecting consumption of forest foods. Baillonella toxisperma (98%) and Irvingia gabonesis (81%) were the most known nutrient rich forest foods by the respondents. About 31% of the respondents were aware of the nutritional value and health benefits of forest foods. About 10%-61% of the respondents expressed positive attitudes to questions related with health benefits of specific forest foods. Consumption of forest foods was found to be higher among polygamous families and also positively related to length of stay in the forest area and age of respondent with consumption of forest foods. Education had an inverse relationship with use of forest foods. Knowledge and positive attitude towards the nutritional value of forest foods were also found to positively influence consumption of forest foods. Since knowledge was found to influence attitude and consumption, there is need to invest in awareness campaigns to strengthen the current knowledge levels among the study population. This should positively influence the attitudes and perceptions towards increased consumption of forest foods.

  15. 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.

  16. Modeling Addictive Consumption as an Infectious Disease.

    PubMed

    Alamar, Benjamin; Glantz, Stanton A

    2006-03-17

    The dominant model of addictive consumption in economics is the theory of rational addiction. The addict in this model chooses how much they are going to consume based upon their level of addiction (past consumption), the current benefits and all future costs. Several empirical studies of cigarette sales and price data have found a correlation between future prices and consumption and current consumption. These studies have argued that the correlation validates the rational addiction model and invalidates any model in which future consumption is not considered. An alternative to the rational addiction model is one in which addiction spreads through a population as if it were an infectious disease, as supported by the large body of empirical research of addictive behaviors. In this model an individual's probability of becoming addicted to a substance is linked to the behavior of their parents, friends and society. In the infectious disease model current consumption is based only on the level of addiction and current costs. Price and consumption data from a simulation of the infectious disease model showed a qualitative match to the results of the rational addiction model. The infectious disease model can explain all of the theoretical results of the rational addiction model with the addition of explaining initial consumption of the addictive good.

  17. Watershed modeling and monitoring for assessing nutrient ...

    EPA Pesticide Factsheets

    Presentation for the American Water Works Association Water Sustainability Conference. The presentation highlights latest results from water quality trading research conducted by ORD using the East Fork Watershed in Southwestern Ohio as a case study. The watershed has a nutrient enrichment problem that is creating harmful algal blooms in a reservoir used for drinking water and recreation. Innovative modeling and monitoring is combined to understand how to best manage this water quality problem and costs associated with this endeavor. The presentation will provide an overview of the water quality trading feasibility research. The research includes the development and evaluation of innovative modeling and monitoring approaches to manage watersheds for nutrient pollution using a whole systems approach.

  18. [Changes in household food and nutrient consumption in Metropolitan Santiago 1988-97 by income].

    PubMed

    Crovetto, Mirta; Uauy, Ricardo

    2010-09-01

    the rise in the prevalence of obesity, diabetes, and other risk factors for cardiovascular diseases and cancer observed in Chile over the past decades may be related to changes in dietary patterns of the population. to report changes in household apparent food-nutrients consumption (HAFNC) for Metropolitan Santiago-Chile 1988-97. the analysis is based on data from household expenditure surveys conducted by the Instituto Nacional de Estadísticas (INE) on a representative sample of the population to define changes in food prices. Information on food and drink purchases were grouped by specific items and expen-ditures standardized across the two surveys. HAFNC was determined based on unit consumed at home and out of home by the total group and by income quintile using national food composition tables. apparent energy consumption increased over the study period by 25%, this was mainly explained by increased consumption of meat and dairy (rich in saturated fats of animal origin) and of processed foods (fat spreads, sweets and pastries) and foods rich in added sugars (sugary drinks and juices). Dietary fiber derived from whole grains, legumes and cereals decreased. The HAFNC of items protective against nutrition related chronic diseases, such as vegetables, fruits and other fiber rich foods remained stable or frankly decreased (legumes and non-starchy vegetables) Fish and other marine foods rich in omega- 3 fats remained low. the changes in apparent food consumption patterns can be characterized by an increase in energy dense, fat and sugar rich foods with a low consumption of fi sh, whole grains, legumes, vegetables and fruits.

  19. Energy and nutrient intakes of Swedish children in relation to consumption of and habits associated with school lunch.

    PubMed

    Persson Osowski, Christine; Becker, Wulf; Enghardt Barbieri, Heléne; Lindroos, Anna Karin

    2017-02-01

    School lunches are provided free in Sweden, although some children choose not to eat school lunch. The aim of this study was to analyse Swedish children's total energy and nutrient intakes on weekdays by the frequency of school lunch consumption and to analyse energy and nutrient intakes from school lunches by sex. Factors associated with children's school lunch habits were also studied. Children in grades 2 and 5 ( n=1905) completed a food diary (school lunch data available for 1840 children) and the mean energy and nutrient intakes per day and per school lunch were calculated. The children also completed questions on the frequency of school lunch consumption and school lunch habits. Logistic regression was used to assess factors associated with school lunch habits. Children who reported eating school lunch every day had significantly higher energy and absolute nutrient intakes than children reporting eating school lunch less than five times a week, but not standardized for energy. Boys had significantly higher energy and absolute nutrient intakes from school lunches than girls, but not standardized for energy. Younger children and children who liked school lunches had higher odds of eating school lunch every day. Children in grade 5, those with a foreign background and those disliking school lunches had higher odds of omitting the main lunch component. Regular school lunch consumption was associated with a higher total intake for most nutrients, but not a better nutrient density. School lunch habits were associated with age, ethnic background and liking school lunches.

  20. 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

  1. Consumption of sugar-sweetened beverages and its association with nutrient intakes and diet quality in German children and adolescents.

    PubMed

    Libuda, Lars; Alexy, Ute; Buyken, Anette E; Sichert-Hellert, Wolfgang; Stehle, Peter; Kersting, Mathilde

    2009-05-01

    In the present study the relationship of sugar-sweetened beverage (SSB) consumption with the intake of single nutrients and total diet quality in German children and adolescents was evaluated using a repeated-measures regression analysis model. We used dietary data from 7145 three-day weighed records of 1069 subjects aged 2-19 years participating in the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study. Intake of macronutrients as percentage of total energy intake (%En), intake of micronutrients as percentage of German reference values (intake quality score) and nutritional quality index (NQI) as an indicator of diet quality were chosen as separate dependent variables. SSB consumption was positively associated with %En from carbohydrates (boys v. girls: +4.00 v. +4.09 En%/MJ from SSB) and added sugars (boys v. girls: +7.36 v. +9.52 En%/MJ from SSB) and negatively with %En from protein (boys v. girls: - 1.25 v. - 1.31 En%/MJ from SSB) and fat (boys: - 2.82 v. - 2.73 En%/MJ from SSB). With respect to micronutrients, SSB consumption was negatively associated with folate and Ca intake, for which mean intake levels were inadequate in girls. Absolute diet quality was negatively associated with SSB consumption, whereas the effect was larger for girls (boys v. girls: - 1.41 v. - 2.63 points of NQI/MJ from SSB). Overall, results show a diluting effect of SSB consumption on micronutrient intake and diet quality. This effect might be relevant especially in girls as the association with diet quality was larger and mean NQI levels were lower in comparison with boys.

  2. Modeling nutrient loads to the northern Adriatic

    NASA Astrophysics Data System (ADS)

    Volf, Goran; Atanasova, Nataša; Kompare, Boris; Ožanić, Nevenka

    2013-11-01

    Simulation of nutrient loads was done for entire NA watershed consisting of 17 individual watersheds.Po River watershed is dominating the nutrient loads to the NA.Agricultural areas and WWTP were identified as the major sources of nutrients to the NA.Proper management decisions were defined to reduce the nutrient loads.

  3. Association between frequency of ready-to-eat cereal consumption, nutrient intakes, and body mass index in fourth- to sixth-grade low-income minority children.

    PubMed

    Balvin Frantzen, Lana; Treviño, Roberto P; Echon, Roger M; Garcia-Dominic, Oralia; DiMarco, Nancy

    2013-04-01

    The consumption of non-ready-to-eat cereal and ready-to-eat cereal (RTEC) breakfasts have been associated with increased nutrient intakes and lower body mass index (BMI). These relationships have not been examined in low-income minority children. To evaluate, in low-income minority children, whether there is a relationship among the frequency of RTEC consumption and nutrient intakes measured at baseline, and whether there is a relationship between the frequency of RTEC and BMI controlling for age, sex, ethnicity, and energy intake. A longitudinal study design where a cohort was followed for 3 years. Participants were 625 fourth- through sixth-grade, low-income children living in San Antonio, Texas, and enrolled in the control arm of the Bienestar Diabetes Prevention Program's cluster randomized trial. Three multiple-pass 24-hour dietary recalls were collected at the beginning of their fourth-grade year and at the end of their fifth- and sixth-grade years. Children's age, sex, ethnicity, and height and weight (used to calculate BMI) were collected between August 2001 and May 2004. Descriptive and inferential statistical analyses were performed. The frequency of breakfast consumption was examined using a 6×4 cross-tabulation table with χ(2) test to establish categorical differences. The degree of association between BMI percentile and frequency of RTEC consumption adjusted for age, sex, ethnicity, and nutrition-related parameters were calculated using a partial correlation multivariate linear model analysis. There was a significant positive relationship between the frequency of RTEC consumption and nutrient intakes measured at baseline. There was also a significant inverse relationship between frequency of RTEC consumption and BMI percentile over the cumulative 3-year period controlling for age, sex, ethnicity, and energy intake. Children who frequently consumed RTEC had greater intakes of essential nutrients at baseline and significantly lower BMI over a 3-year

  4. Unravelling trophic subsidies of agroecosystems for biodiversity conservation: food consumption and nutrient recycling by waterbirds in Mediterranean rice fields.

    PubMed

    Navedo, Juan G; Hahn, Steffen; Parejo, Manuel; Abad-Gómez, José M; Gutiérrez, Jorge S; Villegas, Auxiliadora; Sánchez-Guzmán, Juan M; Masero, José A

    2015-04-01

    Waterbirds can reallocate a considerable amount of nutrients within agricultural fields and between agriculture sites and wetlands. However their effects on biogeochemical cycles have rarely been quantified. We estimated bird numbers, diet (from stable isotope analysis), food supply, and the food consumption on rice fields by overwintering waterbirds in one of the most important areas for rice production in southwestern Europe and a key area for various migrating and resident waterbird species. Herein, we modelled the nutrient (N and P) recycling in rice fields, and their transport to reservoirs. The energy consumption by waterbirds (96,605±18,311 individuals) on rice fields during winter averaged at 89.9±39.0 kJ·m(-2), with its majority (89.9%) belonging to foraging on rice seeds. Thus, the birds removed about 26% of rice seeds leftover after harvest (estimated in 932.5±504.7 seeds·m(-2) in early winter) wherein common cranes and dabbling ducks (four species) were the most important consumers. Waterbirds foraging and roosting in the rice fields recycled more than 24.1 (1.0 kg·ha(-1)) of N and an additional 5.0 tons (0.2 kg·ha(-1)) of P in the Extremadura's rice fields during winter. Additionally, we estimated that 2.3 tons of N and 550 kg of P were removed from rice fields and transported to reservoirs. The seasonal foraging of wildlife should result in a direct benefit for rice farmers by improving nutrient recycling through defecation by waterbirds with respect to artificial fertilisation. Additionally, rice fields located in the cranes' core wintering areas can provide sufficient food supply to induce habitat shift from their traditional wintering habitat in 'dehesas' to rice fields, which causes indirect socioeconomic benefit through reduced acorn consumption by cranes. Our modelling approach may thus be especially helpful for management decisions regarding rice agroecosystems in areas which are also important for the conservation of migratory

  5. Plain Water and Sugar-Sweetened Beverage Consumption in Relation to Energy and Nutrient Intake at Full-Service Restaurants

    PubMed Central

    An, Ruopeng

    2016-01-01

    Background: Drinking plain water, such as tap or bottled water, provides hydration and satiety without adding calories. We examined plain water and sugar-sweetened beverage (SSB) consumption in relation to energy and nutrient intake at full-service restaurants. Methods: Data came from the 2005–2012 National Health and Nutrition Examination Survey, comprising a nationally-representative sample of 2900 adults who reported full-service restaurant consumption in 24-h dietary recalls. Linear regressions were performed to examine the differences in daily energy and nutrient intake at full-service restaurants by plain water and SSB consumption status, adjusting for individual characteristics and sampling design. Results: Over 18% of U.S. adults had full-service restaurant consumption on any given day. Among full-service restaurant consumers, 16.7% consumed SSBs, 2.6% consumed plain water but no SSBs, and the remaining 80.7% consumed neither beverage at the restaurant. Compared to onsite SSB consumption, plain water but no SSB consumption was associated with reduced daily total energy intake at full-service restaurants by 443.4 kcal, added sugar intake by 58.2 g, saturated fat intake by 4.4 g, and sodium intake by 616.8 mg, respectively. Conclusion: Replacing SSBs with plain water consumption could be an effective strategy to balance energy/nutrient intake and prevent overconsumption at full-service restaurant setting. PMID:27153083

  6. Plain Water and Sugar-Sweetened Beverage Consumption in Relation to Energy and Nutrient Intake at Full-Service Restaurants.

    PubMed

    An, Ruopeng

    2016-05-04

    Drinking plain water, such as tap or bottled water, provides hydration and satiety without adding calories. We examined plain water and sugar-sweetened beverage (SSB) consumption in relation to energy and nutrient intake at full-service restaurants. Data came from the 2005-2012 National Health and Nutrition Examination Survey, comprising a nationally-representative sample of 2900 adults who reported full-service restaurant consumption in 24-h dietary recalls. Linear regressions were performed to examine the differences in daily energy and nutrient intake at full-service restaurants by plain water and SSB consumption status, adjusting for individual characteristics and sampling design. Over 18% of U.S. adults had full-service restaurant consumption on any given day. Among full-service restaurant consumers, 16.7% consumed SSBs, 2.6% consumed plain water but no SSBs, and the remaining 80.7% consumed neither beverage at the restaurant. Compared to onsite SSB consumption, plain water but no SSB consumption was associated with reduced daily total energy intake at full-service restaurants by 443.4 kcal, added sugar intake by 58.2 g, saturated fat intake by 4.4 g, and sodium intake by 616.8 mg, respectively. Replacing SSBs with plain water consumption could be an effective strategy to balance energy/nutrient intake and prevent overconsumption at full-service restaurant setting.

  7. Ensemble modelling of nutrient loads and nutrient load partitioning in 17 European catchments.

    PubMed

    Kronvang, B; Behrendt, H; Andersen, H E; Arheimer, B; Barr, A; Borgvang, S A; Bouraoui, F; Granlund, K; Grizzetti, B; Groenendijk, P; Schwaiger, E; Hejzlar, J; Hoffmann, L; Johnsson, H; Panagopoulos, Y; Lo Porto, A; Reisser, H; Schoumans, O; Anthony, S; Silgram, M; Venohr, M; Larsen, S E

    2009-03-01

    An ensemble of nutrient models was applied in 17 European catchments to analyse the variation that appears after simulation of net nutrient loads and partitioning of nutrient loads at catchment scale. Eight models for N and five models for P were applied in three core catchments covering European-wide gradients in climate, topography, soil types and land use (Vansjø-Hobøl (Norway), Ouse (Yorkshire, UK) and Enza (Italy)). Moreover, each of the models was applied in 3-14 other EUROHARP catchments in order to inter-compare the outcome of the nutrient load partitioning at a wider European scale. The results of the nutrient load partitioning show a variation in the computed average annual nitrogen and phosphorus loss from agricultural land within the 17 catchments between 19.1-34.6 kg N ha(-1) and 0.12-1.67 kg P ha(-1). All the applied nutrient models show that the catchment specific variation (range and standard deviation) in the model results is lowest when simulating the net nutrient load and becomes increasingly higher for simulation of the gross nutrient loss from agricultural land and highest for the simulations of the gross nutrient loss from other diffuse sources in the core catchments. The average coefficient of variation for the model simulations of gross P loss from agricultural land is nearly twice as high (67%) as for the model simulations of gross N loss from agricultural land (40%). The variation involved in model simulations of net nutrient load and gross nutrient losses in European catchments was due to regional factors and the presence or absence of large lakes within the catchment.

  8. Following federal guidelines to increase nutrient consumption may lead to higher food costs for consumers.

    PubMed

    Monsivais, Pablo; Aggarwal, Anju; Drewnowski, Adam

    2011-08-01

    The federal Dietary Guidelines for Americans, 2010, emphasized the need for Americans to consume more potassium, dietary fiber, vitamin D, and calcium, and to get fewer calories from saturated fat and added sugar. We examined the economic impact of meeting these guidelines for adults in King County, Washington. We found that increasing consumption of potassium--the most expensive of the four recommended nutrients--would add $380 per year to the average consumer's food costs. Meanwhile, each time consumers obtained 1 percent more of their daily calories from saturated fat and added sugar, their food costs significantly declined. These findings suggest that improving the American diet will require additional guidance for consumers, especially those with little budget flexibility, and new policies to increase the availability and reduce the cost of healthful foods.

  9. 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

  10. 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.

  11. Do nutrient-competition models predict nutrient availabilities in limnetic ecosystems?

    PubMed

    Leibold, Mathew A

    1997-03-01

    Recent theory on resource competition, predicated on the importance of hypothesized trade-offs between minimum requirements for nutrient resources, predicts that there should be negative correlations between the supply rate of major limiting nutrients and the availability of at least some secondary nutrients and/or among the availabilities of different limiting nutrients. However, an analysis of four data sets from large-scale surveys of lakes shows mostly positive correlations among the availabilities and supplies of nutrients. In contrast, a fifth data set, obtained in an area of high acidification, does show several important negative correlations that are consistent with the nutrient competition models. Further analyses suggest two possible explanations for the preponderance of positive correlation. Negative correlations between nutrients and light indicate that an important trade-off among species regulating phytoplankton may involve low light requirements versus low nutrient requirements. The existence of negative correlations in nutrient availabilities in acidic lakes (where herbivory appears less important than in buffered lakes) also suggests that another important trade-off may involve an ability to minimize loss rates (especially due to grazing) versus an overall ability to exploit nutrient resources.

  12. Energy and nutrient intake according to away-from-home food consumption in the Northeast Region: an analysis of the 2008-2009 National Dietary Survey.

    PubMed

    Cavalcante, Jessica Brito; Moreira, Tyciane Maria Vieira; Mota, Caroline da Costa; Pontes, Carolinne Reinaldo; Bezerra, Ilana Nogueira

    2017-01-01

    Away-from-home food consumption has increased in Brazil and is associated with fewer nutritious food choices. To describe energy and specific nutrient intake among consumers and non-consumer of away-from-home food in the Northeast Region. A sample of 11,674 individuals from the National Dietary Survey data, which is part of the 2008-2009 Household Budget Survey, from the Northeast Region, was analyzed. Individuals provided two dietary records in nonconsecutive days, informing the place where foods were consumed (at-home or away-from-home). Away-from-home food was defined as foods acquired and consumed away from home. Linear regression models were developed to assess the relationship between away-from-home food consumption in one of the two-day food record and the energy and nutrient intake, adjusted for age, gender, and per capita income. Away-from-home food consumption, in at least one of the two-day food record, was reported by 42% of individuals in the Northeast Region. Individuals who consumed food away from home in the Northeast Region presented poor nutrient intake compared to those who did not report consumption away from home, with higher intake of energy, free sugar, saturated fat, and trans fat and lower intake of protein, iron, and dietary fiber, regardless of age, gender, and income (p < 0.05). Away-from-home food consumption in the Northeast Region contributed to higher energy and poorer nutrient intake. Therefore, the development of public policies and strategies that favor health food choices when individuals eat away from home is necessary.

  13. How may a shift towards a more sustainable food consumption pattern affect nutrient intakes of Dutch children?

    PubMed

    Temme, Elisabeth H M; Bakker, Helena M E; Seves, S Marije; Verkaik-Kloosterman, Janneke; Dekkers, Arnold L; van Raaij, Joop M A; Ocké, Marga C

    2015-09-01

    Food has a considerable environmental impact. Diets with less meat and dairy reduce environmental impact but may pose nutritional challenges for children. The current modelling study investigates the impact of diets with less or no meat and dairy products on nutrient intakes. Energy and nutrient intakes were assessed for observed consumption patterns (reference) and two replacement scenarios with data from the Dutch National Food Consumption Survey - Young Children (2005-2006). In the replacement scenarios, 30 % or 100 % of the consumed dairy and meat (in grams) was replaced by plant-derived foods with similar use. The Netherlands. Children (n 1279) aged 2-6 years. Partial and full replacement of meat and dairy foods by plant-derived foods reduced SFA intake by 9 % and 26 %, respectively, while fibre intake was 8 % and 29 % higher. With partial replacement, micronutrient intakes were similar, except for lower vitamin B12 intake. After full meat and dairy replacement, mean intakes of Ca, Zn and thiamin decreased by 5-13 %, and vitamin B12 intake by 49 %, while total intake of Fe was higher but of lower bioavailability. With full replacement, the proportion of girls aged 4-6 years with intakes below recommendations was 15 % for thiamin, 10 % for vitamin B12 and 6 % for Zn. Partial replacement of meat and dairy by plant-derived foods is beneficial for children's health by lowering SFA intake, increasing fibre content and maintaining similar micronutrient intakes. When full replacements are made, attention is recommended to ensure adequate thiamin, vitamin B12 and Zn intakes.

  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. 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...

  16. Meeting and exceeding dairy recommendations: effects of dairy consumption on nutrient intakes and risk of chronic disease

    PubMed Central

    Rice, Beth H; Quann, Erin E; Miller, Gregory D

    2013-01-01

    The 2010 Dietary Guidelines for Americans indicate the US population is experiencing an epidemic of overweight and obesity while maintaining a nutrient-poor, energy-dense diet associated with an increased risk of osteoarthritis, cardiovascular disease, and type 2 diabetes. To build upon the review of published research in the Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010, this article aims to review the scientific literature pertaining to the consumption of dairy foods and the effects of dairy consumption on nutrient intakes and chronic disease risk published between June 2010, when the report was released, and September 2011. PubMed was searched for articles using the following key words: dairy, milk, nutrient intake, bone health, body composition, cardiovascular disease, type 2 diabetes, and blood pressure. Evidence indicates that increasing dairy consumption to the recommended amount, i.e., three servings daily for individuals ≥9 years of age, helps close gaps between current nutrient intakes and recommendations. Consuming more than three servings of dairy per day leads to better nutrient status and improved bone health and is associated with lower blood pressure and reduced risk of cardiovascular disease and type 2 diabetes. PMID:23550782

  17. Fruit juice consumption decreases the proportion of children with inadequate intakes of key nutrients: NHANES 2003-2006

    USDA-ARS?s Scientific Manuscript database

    Fruit juice (FJ) consumption has been under scrutiny despite its nutrient profile. NHANES (2003–2006) data were used to compare the proportion of children ages 2–18 years with intakes of selected vitamins/minerals below recommended levels among consumers (n = 3,976; 51% females) and non-consumers (n...

  18. Long Term Trends in Subantarctic Nutrient Consumption: Evidence from Sedimentary and Diatom-Bound Nitrogen Isotopes

    NASA Astrophysics Data System (ADS)

    Bedsole, P.

    2014-12-01

    It has been proposed that the long term increase in Subantarctic opal export during glacial periods, centered around 1 Ma, is related to enhanced iron deposition and, potentially, carbon dioxide drawdown. New bulk sedimentary and diatom-bound nitrogen isotope records are used in combination with opal accumulation data from ODP Site 1090 to investigate controls on export production over the last 3 Ma. Sedimentary nitrogen content tracks opal during periods of high iron accumulation, especially after ~1 Ma. Bulk sedimentary nitrogen isotope trends are negatively correlated with sedimentary N-content and opal accumulation. This may be signal weaker nutrient consumption during times of high production, perhaps as a result of enhanced vertical nutrient supply. Alternatively, this variation in bulk, where high values occur in organic poor intervals, is consistent with other evidence for nitrogen isotopic alteration during periods of low export to the seafloor. The diatom-bound nitrogen isotope record does not have a clear relationship with opal or iron accumulation. A long term shift in the diatom-bound N isotope values is apparent, where the average diatom-bound δ15N from 0.5-1 Ma is 4.4 ‰, and from 2-2.6 Ma is 5.9 ‰. This decrease may reflect long-term changes in nitrate availability. A first order comparison to planktonic/benthic carbon isotopic gradients suggests that enhanced vertical mixing may explain the observed productivity peaks and lower overall diatom-bound N isotope values in the interval centered around 1 Ma.

  19. Dairy product consumption, dietary nutrient and energy density and associations with obesity in Australian adolescents.

    PubMed

    O'Sullivan, T A; Bremner, A P; Bremer, H K; Seares, M E; Beilin, L J; Mori, T A; Lyons-Wall, P; Devine, A; Oddy, W H

    2015-10-01

    Dairy intake is likely to influence dietary energy density (ED) and nutrient density (ND), which are factors representing aspects of dietary quality. Although evidence suggests dairy intake is unlikely to contribute to obesity, intake tends to decrease over adolescence, potentially as a result of concerns around weight gain. We examined associations between dairy intake, ED and ND, and investigated relationships with obesity in adolescents. The present study comprised a cross-sectional study of 1613 14-year-olds in the Western Australian Pregnancy Cohort (Raine) Study. Adolescents completed a 212-item food frequency questionnaire. Nutrient Rich Food index 9.3 (NRF9.3) was used to estimate ND. Age-specific body mass index (BMI) and waist-height cut-offs were used to categorise obesity risk. Mean (SD) dairy intake was: 2.62 (1.51) servings daily; ED was 4.53 (0.83) (food and beverage) and 6.28 (1.33) (food only); ND was 373 (109). Dairy intake was inversely associated with ED and positively associated with ND. The odds of being overweight (as assessed by BMI) increased by 1.24 (95% confidence interval = 1.09-1.42) with each 100-point increase in ND, after adjustment for potential confounders and energy intake. ED measures and dairy intake were inversely associated with obesity after adjustment for confounders; associations became nonsignificant after energy adjustment. The NRF9.3 was originally designed to assess foods, not diets. Further research in other cohorts to determine whether similar findings exist, or investigations into alternate measures of dietary ND, may prove useful. Our findings may be the result of factors such as an excess consumption of refined but fortified foods. Although higher dairy intakes were associated with higher ND, intakes were not associated with higher obesity risk. © 2014 The British Dietetic Association Ltd.

  20. Fast-food and full-service restaurant consumption and daily energy and nutrient intakes in US adults.

    PubMed

    An, R

    2016-01-01

    Calorie intake and diet quality are influenced by the source of food and the place of consumption. This study examines the impacts of fast-food and full-service restaurant consumption on daily energy and nutrient intakes in US adults. Nationally representative data of 18,098 adults 18 years of age and above from the National Health and Nutrition Examination Survey 2003-2010 waves were analyzed. Outcomes included daily intake of total calories and 24 nutrients of public health concern. The key predictors were any food/beverage consumption in a day from fast-food or full-service restaurant, differentiated by consumption at home versus away from home. First-difference estimator addressed confounding bias from time-invariant unobservables such as personal food/beverage preferences by using within-individual variations in diet and restaurant consumption status between two nonconsecutive 24-h dietary recalls. Fast-food and full-service restaurant consumption, respectively, were associated with a net increase in daily total energy intake of 190.29 and 186.74 kcal, total fat of 10.61 and 9.58 g, saturated fat of 3.49 and 2.46 g, cholesterol of 10.34 and 57.90 mg, and sodium of 297.47 and 411.92 mg. The impact of fast-food and full-service restaurant consumption on energy and nutrient intakes differed by sex, race/ethnicity, education, income and weight status. Increased total energy, total fat, saturated fat, cholesterol and sodium intake were substantially larger when full-service restaurant food was consumed away from home than at home. A holistic policy intervention is warranted to target the American's overall dining-out behavior rather than fast-food consumption alone.

  1. Whole-grain consumption is associated with diet quality and nutrient intake in adults: the National Health and Nutrition Examination Survey, 1999-2004

    USDA-ARS?s Scientific Manuscript database

    The consumption of whole grains and its association with nutrient intake has not been assessed in a recent nationally representative population. The objective was to examine the association of consumption of whole grains, using the new whole-grain definition, with diet quality and nutrient intake in...

  2. The third National Food Consumption Survey, INRAN-SCAI 2005-06: major dietary sources of nutrients in Italy.

    PubMed

    Sette, Stefania; Le Donne, Cinzia; Piccinelli, Raffaela; Mistura, Lorenza; Ferrari, Marika; Leclercq, Catherine

    2013-12-01

    To promote healthy food consumption patterns, information is required on the contribution of food groups to total nutrient intake. The objective of this paper is to identify the main dietary sources of nutrients in the diet of the population in Italy. Data collected through individual food records within the INRAN-SCAI 2005-06 survey were required. The final sample included 3323 subjects aged 0.1-97.7 years. The percentage contributed by each food category to the intake of energy, dietary fibre and of 26 nutrients was calculated. Above 3 years of age, the main contributors to macro- and micro-nutrient intakes were similar among the various age-sex groupings with few exceptions. These data might be used to develop specific strategies for Italy in order to increase the intake of dietary fibre and to decrease that of total fats and of sugars in the population.

  3. The impact of restaurant consumption among US adults: effects on energy and nutrient intakes.

    PubMed

    Nguyen, Binh T; Powell, Lisa M

    2014-11-01

    To examine the effect of fast-food and full-service restaurant consumption on adults' energy intake and dietary indicators. Individual-level fixed-effects regression model estimation based on two different days of dietary intake data was used. Parallel to the rising obesity epidemic in the USA, there has been a marked upward trend in total energy intake derived from food away from home. The full sample included 12 528 respondents aged 20-64 years who completed 24 h dietary recall interviews for both day 1 and day 2 in the National Health and Nutrition Examination Survey (NHANES) 2003-2004, 2005-2006, 2007-2008 and 2009-2010. Fast-food and full-service restaurant consumption, respectively, was associated with an increase in daily total energy intake of 813·75 kJ (194·49 kcal) and 858·04 kJ (205·21 kcal) and with higher intakes of saturated fat (3·48 g and 2·52 g) and Na (296·38 mg and 451·06 mg). Individual characteristics moderated the impacts of restaurant food consumption with adverse impacts on net energy intake being larger for black adults compared with their white and Hispanic counterparts and greater for middle-income v. high-income adults. Adults' fast-food and full-service restaurant consumption was associated with higher daily total energy intake and poorer dietary indicators.

  4. Food consumption and nutrient intake in Italian school children: results of the ZOOM8 study.

    PubMed

    Martone, Deborah; Roccaldo, Romana; Censi, Laura; Toti, Elisabetta; Catasta, Giovina; D'Addesa, Dina; Carletti, Claudia

    2013-09-01

    The food consumption and food habits of Italian third-class-primary-school children were assessed and their energy and nutrient intakes were compared with requirements. The study involved 1740 subjects (900 males and 840 females) aged 8-9 years, from the north, centre and south of Italy. Body weight and height were measured. Parents filled in a semi-quantitative Food Frequency Questionnaire for their child. The results showed that the diet of Italian children is unbalanced in terms of macronutrients and deficient in fiber. The average daily intakes of fruit (234 g/d), vegetables (134 g/d) and legumes (17 g/d), were lower than the nationally recommended ones. The percentages of energy intake from fats (41%) and from carbohydrates (45%) were higher and lower respectively than recommended. Low intakes of fiber (13.5 g/d) were reported. A national nutrition policy in Italy should focus on nutrition education programs in schools and for parents.

  5. Kootenai River Nutrient Dosing System and N-P Consumption: Year 2008.

    SciTech Connect

    Holderman, Charles

    2009-02-19

    In early 2006 we designed and built low energy consumption, pump-operated system, for dosing of the liquid nutrient in the summer 2006 season. This operated successfully, and the system was used again during the 2007 and 2008 seasons for dosing. During the early winter period, 2008, laboratory tests were made of the liquid nutrient pump system, and it was noted that small amounts of air were being entrained on the suction side of the pump, during conditions when the inlet pressure was low. It was believed that this was the cause of diurnal fluctuations in the flow supplied, characteristic of the 2007 year flow data. Replacement of '0' rings on the inlet side of the pumps was the solution to this problem, and when tested in the field during the summer season, the flow supplied was found to be stable. A decision was made by the IKERT committee at the meeting of 20th to 21st May 2008 (held in Coeur d'Alene, Idaho) to use an injection flow rate of liquid fertilizer (polyammonium phosphate 10-34-0) to achieve a target phosphorus concentration of 3.0 {micro}g/L, after complete mixing in the river. This target concentration was the same as that used in 2006 and 2007. The proposed starting date was as early as possible in June 2008. Plans were made to measure the dosing flow in three ways. Two of the three methods of flow measurement (1 and 2 below) are inter-dependent. These were: (1) Direct measurement of flow rate by diverting dosing flow into a 1000 mL volume standard flask. The flow rate was computed by dividing the flask volume by the time required to fill the flask. This was done a few times only during the summer period. (2) Adjusting the flow rate reading of the Gamma dosing pump using the 'calibration' function to achieve agreement with the flow rate computed by method 1 above. (3) Direct measurement by electrical signal from conductive fluid passing through a magnetic field (Seametrics meter, as used in previous years). Values were recorded every 4 minutes by a

  6. Modelling nutrient reduction targets - model structure complexity vs. data availability

    NASA Astrophysics Data System (ADS)

    Capell, Rene; Lausten Hansen, Anne; Donnelly, Chantal; Refsgaard, Jens Christian; Arheimer, Berit

    2015-04-01

    In most parts of Europe, macronutrient concentrations and loads in surface water are currently affected by human land use and land management choices. Moreover, current macronutrient concentration and load levels often violate European Water Framework Directive (WFD) targets and effective measures to reduce these levels are sought after by water managers. Identifying such effective measures in specific target catchments should consider the four key processes release, transport, retention, and removal, and thus physical catchment characteristics as e.g. soils and geomorphology, but also management data such as crop distribution and fertilizer application regimes. The BONUS funded research project Soils2Sea evaluates new, differentiated regulation strategies to cost-efficiently reduce nutrient loads to the Baltic Sea based on new knowledge of nutrient transport and retention processes between soils and the coast. Within the Soils2Sea framework, we here examine the capability of two integrated hydrological and nutrient transfer models, HYPE and Mike SHE, to model runoff and nitrate flux responses in the 100 km2 Norsminde catchment, Denmark, comparing different model structures and data bases. We focus on comparing modelled nitrate reductions within and below the root zone, and evaluate model performances as function of available model structures (process representation within the model) and available data bases (temporal forcing data and spatial information). This model evaluation is performed to aid in the development of model tools which will be used to estimate the effect of new nutrient reduction measures on the catchment to regional scale, where available data - both climate forcing and land management - typically are increasingly limited with the targeted spatial scale and may act as a bottleneck for process conceptualizations and thus the value of a model as tool to provide decision support for differentiated regulation strategies.

  7. Effects of nutrient enrichment on channel catfish growth and consumption in Mount Storm Lake, West Virginia

    USGS Publications Warehouse

    Blanc, T.J.; Margraf, F.J.

    2002-01-01

    With the objective of augmenting fish production in Mount Storm Lake, Virginia Electric and Power Company initiated a programme of phosphorus addition to increase primary production, and ultimately, channel catfish (Ictaturus punctatus) growth in the 486 ha cooling reservoir. We simulated channel catfish growth dynamics using two bioenergetics modelling scenarios: (i) effects of average reservoir temperature on growth, conversion efficiency and consumption; and (ii) effects of reservoir enrichment on growth, which is simulated by increasing feeding rates. During 1991-1993, fish were sampled monthly, but sampling was increased to every 2 weeks during the peak growing season (June-September). Most of the channel catfish collected were aged 0 year and aged 1 year with rapid annual growth rates ranging from 9.0 to 13.7 J/g. We found many age 1 250-300 mm catfish, but few beyond this size. Conversion efficiency (joules gained/joules consumed) was low at approximately 18-19%. High algae consumption (40%) was evident, but consumption of zooplankton and Asiatic clam (Corbicula sp.) increased over the study. Simulated increased feeding rates showed that channel catfish were food limited in summer and fall (July-December). Weight gains with 5 and 10% feeding increases were 6-13% and 18-38%, respectively, from the baseline. Catfish of all sizes should benefit from phosphorus additions.

  8. 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...

  9. 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...

  10. Dietary taurine and nutrient intake and dietary quality by alcohol consumption level in Korean male college students.

    PubMed

    You, Jeong Soon; Kim, So Young; Park, So Yoon; Chang, Kyung Ja

    2013-01-01

    Heavy alcohol consumption is related to various negative healthy consequences. To investigate difference of taurine intake according to the alcohol consumption level, we studied body composition, intake of dietary nutrients including taurine, and dietary quality in Korean male college students that were divided according to their alcohol consumption level. Surveys were conducted using a questionnaire and a 3-day recall method for assessing dietary intake in 220 male college students residing in Incheon, Korea. The subjects were divided into two groups by alcohol consumption level: heavy drinking group (average drinking over 5 cans (355 ml) of beer or 7 shots (45 ml) of soju) and light drinking group (average drinking less than 5 cans of beer or 7 shots of soju or not drinking any alcohol at all at one time during the previous month). The average body mass index (BMI) in the heavy drinking group was significantly higher compared to the light drinking group (p < 0.05). There was no significant difference in dietary taurine intake between heavy and light drinking group. With regard to the dietary quality evaluation of the subjects, the nutrient densities (ND) of carbohydrate, niacin, vitamin C, and zinc in the heavy drinking group were significantly lower than those of the light drinking group. Therefore, continuous nutrition education for heavy drinking Korean male college students may be needed to improve balanced nutritional status and further studies such as case-control study or taurine intervention study are required to know the relationship between dietary taurine intake and alcohol consumption.

  11. Short communication: Nutrient consumption patterns of Lactobacillus acidophilus KLDS 1.0738 in controlled pH batch fermentations.

    PubMed

    Lv, Xuepeng; Liu, Gefei; Sun, Xiaomei; Chen, Hongyu; Sun, Jiahui; Feng, Zhen

    2017-07-01

    This work focused on elucidating the nutrient consumption patterns of Lactobacillus acidophilus to guide the design of media for high-cell-density culture. We investigated the nutrient consumption patterns of L. acidophilus KLDS 1.0738 in chemically defined media in controlled pH batch fermentations. The most abundantly consumed amino acids, vitamins, ions, and purines and pyrimidines were Glu and Gly, pyridoxine and nicotinamide, K(+) and PO4(3-), and guanine and uracil, respectively. The highest consumption rates for amino acids, vitamins, ions, and purines and pyrimidines were Asp and Arg, folic acid and pyridoxine, Fe(2+) and Mn(2+), and uracil and thymine, respectively. Furthermore, most of the amino acids, as well as guanine, thymine, pyridoxine, folic acid, nicotinamide, Mg(2+), PO4(3-), and K(+) had the highest bioavailability from the end of the lag growth phase to the mid-exponential growth phase. The overall consumption of glucose, adenine nucleotides, 2'-deoxyguanosine monohydrate, calcium pantothenate, Fe(2+) and Mn(2+) decreased with increasing average growth rate, indicating more effective use of these nutritional components at a higher average growth rate, as biomass yield based on nutritional component consumption increased. Our findings help to formulate complex media for high-cell-density cultivation and provide a theoretical basis for L. acidophilus feeding strategies. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Fast-food consumption among US adults and children: dietary and nutrient intake profile.

    PubMed

    Paeratakul, Sahasporn; Ferdinand, Daphne P; Champagne, Catherine M; Ryan, Donna H; Bray, George A

    2003-10-01

    To examine the dietary profile associated with fast-food use. To compare the dietary intake of individuals on the day that they ate fast food with the day that fast food was not eaten. Cross-sectional study design. The dietary intake of individuals who reported eating fast food on one or both survey days was compared with those who did not report eating fast food. Among the individuals who reported eating fast food, dietary intake on the day when fast food was eaten was compared with the day when fast food was not eaten. Weighted comparison of mean intakes and pairwise t-test were used in the statistical analysis. Subjects/setting Data from 17370 adults and children who participated in the 1994-1996 and 1998 Continuing Survey of Food Intakes by Individuals. Dietary intake data were collected by 2 non-consecutive 24-hour dietary recalls. Fast-food use was reported by 37% of the adults and 42% of the children. Adults and children who reported eating fast food had higher intake of energy, fat, saturated fat, sodium, carbonated soft drink, and lower intake of vitamins A and C, milk, fruits and vegetables than those who did not reported eating fast food (P<.001). Similar differences were observed among individuals between the day when fast food was eaten and the day when fast food was not eaten. Consumers should be aware that consumption of high-fat fast food may contribute to higher energy and fat intake, and lower intake of healthful nutrients.

  13. A continuum model of cell proliferation and nutrient transport in a perfusion bioreactor.

    PubMed

    Shakeel, Muhammad; Matthews, Paul C; Graham, Richard S; Waters, Sarah L

    2013-03-01

    Tissue engineering aims to regenerate, repair or replace organs or defective tissues. This tissue regeneration often occurs in a bioreactor. Important challenges in tissue engineering include ensuring adequate nutrient supply, maintaining the desired cell distribution and achieving sufficiently high cell yield. To put laboratory experiments into a theoretical framework, mathematical modelling of the physical and biochemical processes involved in tissue growth is a useful tool. In this work, we derive and solve a model for a cell-seeded porous scaffold placed in a perfusion bioreactor in which fluid delivers nutrients to the cells. The model describes the key features, including fluid flow, nutrient delivery, cell proliferation and consequent variation of scaffold porosity. Fluid flow through the porous scaffold is modelled by Darcy's law, and nutrient delivery is described by a reaction-advection-diffusion equation. A reaction-diffusion equation describes the evolution of cell density, in which cell proliferation is modelled via logistic growth and cell spreading via non-linear diffusion, which depends on cell density. The effect of shear stress on nutrient consumption and cell proliferation is also included in the model. COMSOL (a commercial finite element solver) is used to solve the model numerically. The results reveal the dependence of the cell distribution and total cell yield on the initial cell density and scaffold porosity. We suggest various seeding strategies and scaffold designs to improve the cell distribution and total cell yield in the engineered tissue construct.

  14. Patterns of food and nutrient consumption in northern Iran, a high-risk area for esophageal cancer.

    PubMed

    Islami, Farhad; Malekshah, Akbar Fazeltabar; Kimiagar, Masoud; Pourshams, Akram; Wakefield, Jon; Goglani, Goharshad; Rakhshani, Nasser; Nasrollahzadeh, Dariush; Salahi, Rasoul; Semnani, Shahryar; Saadatian-Elahi, Mitra; Abnet, Christian C; Kamangar, Farin; Dawsey, Sanford M; Brennan, Paul; Boffetta, Paolo; Malekzadeh, Reza

    2009-01-01

    Our objectives were to investigate patterns of food and nutrient consumption in Golestan province, a high-incidence area for esophageal cancer (EC) in northern Iran. Twelve 24-h dietary recalls were administered during a 1-yr period to 131 healthy participants in a pilot cohort study. We compare here nutrient intake in Golestan with recommended daily allowances (RDAs) and lowest threshold intakes (LTIs). We also compare the intake of 27 food groups and nutrients among several population subgroups using mean values from the 12 recalls. Rural women had a very low level of vitamin intake, which was even lower than LTIs (P < 0.01). Daily intake of vitamins A and C was lower than LTI in 67% and 73% of rural women, respectively. Among rural men, the vitamin intakes were not significantly different from LTIs. Among urban women, the vitamin intakes were significantly lower than RDAs but were significantly higher than LTIs. Among urban men, the intakes were not significantly different from RDAs. Compared to urban dwellers, intake of most food groups and nutrients, including vitamins, was significantly lower among rural dwellers. In terms of vitamin intake, no significant difference was observed between Turkmen and non-Turkmen ethnics. The severe deficiency in vitamin intake among women and rural dwellers and marked differences in nutrient intake between rural and urban dwellers may contribute to the observed epidemiological pattern of EC in Golestan, with high incidence rates among women and people with low socioeconomic status and the highest incidence rate among rural women.

  15. Nutrient utilisation and intestinal fermentation are differentially affected by the consumption of resistant starch varieties and conventional fibres in pigs.

    PubMed

    Rideout, Todd C; Liu, Qiang; Wood, Peter; Fan, Ming Z

    2008-05-01

    This study examined the influence of different resistant starch (RS) varieties and conventional fibres on the efficiency of nutrient utilisation and intestinal fermentation in pigs. Thirty-six pigs (30 kg) were fed poultry meal-based diets supplemented with 10 % granular resistant corn starch (GCS), granular resistant potato starch (GPS), retrograded resistant corn starch (RCS), guar gum (GG) or cellulose for 36 d according to a completely randomised block design. Distal ileal and total tract recoveries were similar (P>0.05) among the RS varieties. Distal ileal starch recovery was higher (P < 0.05) in pigs consuming the RS diets (27-42 %) as compared with the control group (0.64 %). Consumption of GCS reduced (P < 0.05) apparent total tract digestibility and whole-body retention of crude protein in comparison with the control group. Consumption of GPS reduced (P < 0.05) total tract Ca digestibility and whole-body retention of Ca and P compared with the control group. However, consumption of RCS increased (P < 0.05) total tract Ca digestibility compared with the control group. Caecal butyrate concentration was increased (P < 0.05) following consumption of RCS and GG in comparison with the control group. Consumption of all the RS varieties reduced (P < 0.05) caecal indole concentrations compared with the control. Caecal butyrate concentrations were positively correlated (P < 0.05; r 0.63-0.83) with thermal properties among the RS varieties. We conclude that nutrient utilisation and intestinal fermentation are differentially affected by the consumption of different RS varieties and types of fibres. Thermal properties associated with different RS varieties may be useful markers for developing RS varieties with specific functionality.

  16. Maternal high fat and/or salt consumption induces sex-specific inflammatory and nutrient transport in the rat placenta.

    PubMed

    Reynolds, Clare M; Vickers, Mark H; Harrison, Claudia J; Segovia, Stephanie A; Gray, Clint

    2015-05-01

    Maternal high fat and salt consumption are associated with developmental programming of disease in adult offspring. Inadequacies in placental nutrient transport may explain these 'programmed effects'. Diet-induced inflammation may have detrimental effects on placental function leading to alteration of key nutrient transporters. We examined the effects of maternal high fat and/or salt diets on markers of placental nutrient transport and inflammation. Sprague-Dawley rats were assigned to (1) control (CD; 1% Salt 10% kcal from fat); (2) high salt (SD; 4% salt, 10% kcal from fat); (3) high fat (HF; 1% Salt 45% kcal from fat) or (4) high fat high salt (HFSD; 4% salt, 45% kcal from fat) 21 days prior to and throughout gestation. At embryonic day 18, dams were killed by isoflurane anesthesia followed by decapitation; placenta/fetuses were weighed, sexed, and collected for molecular analysis. Maternal SD, HF, and HFSD consumption decreased weight of placenta derived from male offspring; however, weight of placenta derived from female offspring was only reduced with maternal HF diet. This was associated with increased expression of LPL, SNAT2, GLUT1, and GLUT4 in placenta derived from male offspring suggesting increased fetal exposure to free fatty acids and glucose. Maternal SD, HF, and HFSD diet consumption increased expression of proinflammatory mediators IL-1β, TNFα, and CD68 in male placenta. Our results suggest that a proinflammatory placental profile results in detrimental alterations in nutrient transport which may contribute to the developmental origins of cardio-metabolic disturbances in offspring throughout life.

  17. Food and nutrient intakes of French frequent seafood consumers with regard to fish consumption recommendations: results from the CALIPSO study.

    PubMed

    Sirot, Véronique; Dumas, Céline; Leblanc, Jean-Charles; Margaritis, Irène

    2011-05-01

    Besides providing n-3 fatty acids with nutritional and health benefits, seafood consumption may contribute to the reduction of nutrient prevalences of inadequacy. To evaluate the contributions of seafood and other food groups to nutrient intakes of frequent seafood consumers, food consumption was evaluated through an FFQ on 991 French men and women (18-81 years) consuming seafood at least twice a week. Intakes, prevalence of inadequacies, risks of upper limit excess and food contributions to intakes were assessed for thirty-three nutrients. Mean fat contributions to total energy intakes (38·3 and 39·0 % for men and women, respectively) met French recommendations, but mean carbohydrate intakes (40·9 and 39·7 %, respectively) were insufficient. Micronutrient inadequacies were lower than in the French general population, the highest being for vitamin C (41·3 and 40·1 % for men and women, respectively), vitamin E (35·0 and 35·3 % for men and women, respectively) and Mg (37·5 and 25·5 % for men and women, respectively). Upper safety limits (USL) were exceeded mostly for Zn (6·2 %), Ca (3·7 %), retinol (2·0 %) and Cu (0·9 %). Mean contributions of seafood to vitamin D, B12, I and Se intakes ranged 40-65 %. Molluscs and crustaceans significantly contributed to vitamin B12 (13·7 %), Cu (11·4 %), Fe (11·5 %), Zn (8·4 %) and I (6·1 %) intakes, and canned fish contributed to vitamin D intake (13·4 %). Besides fish, contributions of mollusc and crustacean consumption to nutrient intakes should be considered from a public health viewpoint. Consuming seafood at least twice a week induces moderate inadequacies and risks of exceeding USL for some micronutrients, whereas macronutrient intakes remained imbalanced.

  18. Avocado consumption by adults is associated with better nutrient intake, diet quality, and some measures of adiposity: National Health and Nutrition Examination Survey, 2001-2012

    USDA-ARS?s Scientific Manuscript database

    Avocados contain a beneficial lipid profile, including a high level of monounsaturated fatty acids, as well as dietary fiber, essential nutrients, and phytochemicals. However, little epidemiologic data exist on the effect that consumption of avocados has on overall nutrient intake, diet quality, adi...

  19. Tree nut consumption is associated with better nutrient adequacy and diet quality in adults: National Health and Nutrition Examination Survey 2005-2010

    USDA-ARS?s Scientific Manuscript database

    Nutrient adequacy of tree nut consumers has not been examined. The National Health and Nutrition Examination Survey 2005–2010 data were used to assess the association of tree nut consumption by adults 19+ years with nutrient adequacy and diet quality. Covariate adjusted usual intake was determined u...

  20. Meat Consumption, Related Nutrients, Obesity and Risk of Prostate Cancer: a Case-Control Study in Uruguay.

    PubMed

    Stefani, Eduardo De; Boffetta, Paolo L; Ronco, Alvaro; Deneo-Pellegrini, Hugo

    2016-01-01

    In order to determine the role of meat consumption and related nutrients in the etiology of prostate cancer we conducted a case-control study among Uruguayan men in the time period 1998-2007. The study included 464 cases and 472 controls, frequency matched for age and residence. Both series were drawn from the four major public hospitals in Montevideo. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95 % confidence intervals (95 % CI) of prostate cancer by quartiles of meat intake and related nutrients. The highest vs. the lowest quartile of intake of total meat (OR = 5.19, 95 % CI 3.46-7.81), red meat (OR = 4.64, 95 % CI 3.10-6.95), and processed meat (OR = 1.78, 95% CI 1.22-2.59) were associated with increased risk of prostate cancer. Meat nutrients were directly associated with the risk of prostate cancer (OR for cholesterol 5.61, 95 % CI 3.75-8.50). Moreover, both total meat and red meat displayed higher risks among obese patients. This study suggests that total and red meat and meat nutrients may play a role in the etiology of prostate cancer in Uruguay.

  1. Including spatial data in nutrient balance modelling on dairy farms

    NASA Astrophysics Data System (ADS)

    van Leeuwen, Maricke; van Middelaar, Corina; Stoof, Cathelijne; Oenema, Jouke; Stoorvogel, Jetse; de Boer, Imke

    2017-04-01

    The Annual Nutrient Cycle Assessment (ANCA) calculates the nitrogen (N) and phosphorus (P) balance at a dairy farm, while taking into account the subsequent nutrient cycles of the herd, manure, soil and crop components. Since January 2016, Dutch dairy farmers are required to use ANCA in order to increase understanding of nutrient flows and to minimize nutrient losses to the environment. A nutrient balance calculates the difference between nutrient inputs and outputs. Nutrients enter the farm via purchased feed, fertilizers, deposition and fixation by legumes (nitrogen), and leave the farm via milk, livestock, manure, and roughages. A positive balance indicates to which extent N and/or P are lost to the environment via gaseous emissions (N), leaching, run-off and accumulation in soil. A negative balance indicates that N and/or P are depleted from soil. ANCA was designed to calculate average nutrient flows on farm level (for the herd, manure, soil and crop components). ANCA was not designed to perform calculations of nutrient flows at the field level, as it uses averaged nutrient inputs and outputs across all fields, and it does not include field specific soil characteristics. Land management decisions, however, such as the level of N and P application, are typically taken at the field level given the specific crop and soil characteristics. Therefore the information that ANCA provides is likely not sufficient to support farmers' decisions on land management to minimize nutrient losses to the environment. This is particularly a problem when land management and soils vary between fields. For an accurate estimate of nutrient flows in a given farming system that can be used to optimize land management, the spatial scale of nutrient inputs and outputs (and thus the effect of land management and soil variation) could be essential. Our aim was to determine the effect of the spatial scale of nutrient inputs and outputs on modelled nutrient flows and nutrient use efficiencies

  2. Traditional food consumption is associated with higher nutrient intakes in Inuit children attending childcare centres in Nunavik.

    PubMed

    Gagné, Doris; Blanchet, Rosanne; Lauzière, Julie; Vaissière, Émilie; Vézina, Carole; Ayotte, Pierre; Déry, Serge; Turgeon O'Brien, Huguette

    2012-07-17

    To describe traditional food (TF) consumption and to evaluate its impact on nutrient intakes of preschool Inuit children from Nunavik. A cross-sectional study. Dietary intakes of children were assessed with a single 24-hour recall (n=217). TF consumption at home and at the childcare centres was compared. Differences in children's nutrient intakes when consuming or not consuming at least 1 TF item were examined using ANCOVA. A total of 245 children attending childcare centres in 10 communities of Nunavik were recruited between 2006 and 2010. The children's mean age was 25.0±9.6 months (11-54 months). Thirty-six percent of children had consumed at least 1 TF item on the day of the recall. TF contributed to 2.6% of total energy intake. Caribou and Arctic char were the most reported TF species. Land animals and fish/shellfish were the main contributors to energy intake from TF (38 and 33%, respectively). In spite of a low TF intake, children who consumed TF had significantly (p<0.05) higher intakes of protein, omega-3 fatty acids, iron, phosphorus, zinc, copper, selenium, niacin, pantothenic acid, riboflavin, and vitamin B12, and lower intakes of energy and carbohydrate compared with non-consumers. There was no significant difference in any of the socio-economic variables between children who consumed TF and those who did not. Although TF was not eaten much, it contributed significantly to the nutrient intakes of children. Consumption of TF should be encouraged as it provides many nutritional, economic, and sociocultural benefits.

  3. Traditional food consumption is associated with higher nutrient intakes in Inuit children attending childcare centres in Nunavik

    PubMed Central

    Gagné, Doris; Blanchet, Rosanne; Lauzière, Julie; Vaissière, Émilie; Vézina, Carole; Ayotte, Pierre; Déry, Serge; O'Brien, Huguette Turgeon

    2012-01-01

    Objectives To describe traditional food (TF) consumption and to evaluate its impact on nutrient intakes of preschool Inuit children from Nunavik. Design A cross-sectional study. Methods Dietary intakes of children were assessed with a single 24-hour recall (n=217). TF consumption at home and at the childcare centres was compared. Differences in children's nutrient intakes when consuming or not consuming at least 1 TF item were examined using ANCOVA. Results A total of 245 children attending childcare centres in 10 communities of Nunavik were recruited between 2006 and 2010. The children's mean age was 25.0±9.6 months (11–54 months). Thirty-six percent of children had consumed at least 1 TF item on the day of the recall. TF contributed to 2.6% of total energy intake. Caribou and Arctic char were the most reported TF species. Land animals and fish/shellfish were the main contributors to energy intake from TF (38 and 33%, respectively). In spite of a low TF intake, children who consumed TF had significantly (p<0.05) higher intakes of protein, omega-3 fatty acids, iron, phosphorus, zinc, copper, selenium, niacin, pantothenic acid, riboflavin, and vitamin B12, and lower intakes of energy and carbohydrate compared with non-consumers. There was no significant difference in any of the socio-economic variables between children who consumed TF and those who did not. Conclusion Although TF was not eaten much, it contributed significantly to the nutrient intakes of children. Consumption of TF should be encouraged as it provides many nutritional, economic, and sociocultural benefits. PMID:22818718

  4. Tree nut consumption improves nutrient intake and diet quality in US adults: an analysis of National Health and Nutrition Examination Survey (NHANES) 1999-2004

    USDA-ARS?s Scientific Manuscript database

    Recent epidemiologic studies assessing tree nut (almonds, Brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pine nuts, pistachios, and walnuts) consumption and the association with nutrient intake and diet quality are lacking. This study determined the association of tree nut consumption and ...

  5. 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.

  6. 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.

  7. Fast-Food and Full-service Restaurant Consumption among Children and Adolescents: Impact on Energy, Beverage and Nutrient Intake

    PubMed Central

    Powell, Lisa M.; Nguyen, Binh T.

    2013-01-01

    Objective To examine the impact of fast-food and full-service restaurant consumption on total energy intake, dietary indicators and beverage consumption. Design Individual-level fixed effects estimation based on two non-consecutive 24-hour dietary recalls. Setting Nationally representative data from the 2003–2004, 2005–2006, and 2007–2008 National Health and Nutrition Examination Survey. Participants Children aged 2 to 11 (N=4717) and adolescents aged 12 to 19 (N=4699) Main Outcome Measures Daily total energy intake in kilocalories, intakes of grams of sugar, fat, saturated fat and protein and milligrams of sodium and total grams of sugar-sweetened beverages (SSBs), regular soda and milk consumed. Results Fast-food and full-service restaurant consumption, respectively, was associated with a net increase in daily total energy intake of 126 kcal and 160 kcal for children and 310 kcal and 267 kcal for adolescents and higher intakes of regular soda (+74g and +88g for children and +163g and +107g for adolescents) and SSBs generally. Fast-food consumption increased intakes of total fat (+7–8g), saturated fat (+2–5g) and sugar (+6–16g) for both age groups and sodium (+396mg) and protein (+8g) for adolescents. Full-service restaurant consumption was associated with increases in all nutrients examined. Additional key findings were 1) adverse impacts on diet were larger for lower-income children and adolescents; and, 2) among adolescents, increased soda intake was twice as large when fast food was consumed away from home than at home. Conclusions Fast-food and full-service restaurant consumption is associated with higher net total energy intake and poorer diet quality. PMID:23128151

  8. Fast-food and full-service restaurant consumption among children and adolescents: effect on energy, beverage, and nutrient intake.

    PubMed

    Powell, Lisa M; Nguyen, Binh T

    2013-01-01

    To examine the effect of fast-food and full-service restaurant consumption on total energy intake, dietary indicators, and beverage consumption. Individual-level fixed-effects estimation based on 2 nonconsecutive 24-hour dietary recalls. Nationally representative data from the 2003-2004, 2005-2006, and 2007-2008 National Health and Nutrition Examination Survey. Children aged 2 to 11 years (n = 4717) and adolescents aged 12 to 19 years (n = 4699). Daily total energy intake in kilocalories; intake of grams of sugar, total fat, saturated fat, and protein and milligrams of sodium; and total grams of sugar-sweetened beverages, regular soda, and milk consumed. Fast-food and full-service restaurant consumption, respectively, was associated with a net increase in daily total energy intake of 126.29 kcal and 160.49 kcal for children and 309.53 kcal and 267.30 kcal for adolescents and with higher intake of regular soda (73.77 g and 88.28 g for children and 163.67 g and 107.25 g for adolescents) and sugar-sweetened beverages generally. Fast-food consumption increased intake of total fat (7.03-14.36 g), saturated fat (1.99-4.64 g), and sugar (5.71-16.24 g) for both age groups and sodium (396.28 mg) and protein (7.94 g) for adolescents. Full-service restaurant consumption was associated with increases in all nutrients examined. Additional key findings were (1) adverse effects on diet were larger for lower-income children and adolescents and (2) among adolescents, increased soda intake was twice as large when fast food was consumed away from home than at home. Fast-food and full-service restaurant consumption is associated with higher net total energy intake and poorer diet quality.

  9. Consumption of Mass Communication--Construction of a Model on Information Consumption Behaviour.

    ERIC Educational Resources Information Center

    Sepstrup, Preben

    A general conceptual model on the consumption of information is introduced. Information as the output of the mass media is treated as a product, and a model on the consumption of this product is developed by merging elements from consumer behavior theory and mass communication theory. Chapter I gives basic assumptions about the individual and the…

  10. Modeling the relative importance of nutrient and carbon loads ...

    EPA Pesticide Factsheets

    The Louisiana continental shelf (LCS) in the northern Gulf of Mexico experiences bottom water hypoxia in the summer. In order to gain a more fundamental understanding of the controlling factors leading to hypoxia, the Gulf of Mexico Dissolved Oxygen Model (GoMDOM) was applied to this area to simulate dissolved oxygen concentrations in the water as a function of various nutrient loadings. The model is a numerical, biogeochemical, three-dimensional ecological model that receives its physical transport data from the Navy Coastal Ocean Model (NCOM-LCS). GoMDOM was calibrated to a large set of nutrient, phytoplankton, dissolved oxygen, sediment nutrient flux, sediment oxygen demand (SOD), primary production, and respiration data collected in 2006 and corroborated with field data collected in 2003. The primary objective was to use the model to estimate a nutrient load reduction of both nitrogen and phosphorus necessary to reduce the size of the hypoxic area to 5,000 km2, a goal established in the 2008 Gulf of Mexico Hypoxia Action Plan prepared by the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force. Using the year 2006 as a test case, the model results suggest that the nitrogen and phosphorus load reduction from the Atchafalaya and Mississippi River basins would need to be reduced by 64% to achieve the target hypoxia area. The Louisiana continental shelf (LCS) in the northern part of the Gulf of Mexico has a history of subsurface hypoxia in the summer.

  11. 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.

  12. Benthic nutrient fluxes and sediment oxygen consumption in a full-scale facultative pond in Patagonia, Argentina.

    PubMed

    Faleschini, M; Esteves, J L

    2013-01-01

    The study of benthic metabolism is an interesting tool to understand the process that occurs in bottom water at wastewater stabilization ponds. Here, rates of benthic oxygen consumption and nutrient exchange across the water-sludge interface were measured in situ using a benthic chamber. The research was carried out during autumn, winter, and summer at a municipal facultative stabilization pond working in a temperate region (Puerto Madryn city, Argentina). Both a site near the raw wastewater inlet (Inlet station) and a site near the outlet (Outlet station) were sampled. Important seasonal and spatial patterns were identified as being related to benthic fluxes. Ammonium release ranged from undetectable (autumn/summer - Inlet station) to +30.7 kg-NH4(+) ha(-1) d(-1) (autumn - Outlet station), denitrification ranged from undetectable (winter - in both sites) to -4.0 kg-NO3(-) ha(-1) d(-1) (autumn - Outlet station), and oxygen consumption ranged from 0.07 kg-O2ha(-1) d(-1) (autumn/summer - Outlet station) to 0.84 kg-O2ha(-1) d(-1) (autumn - Inlet station). During the warmer months, the mineralization of organic matter from the bottom pond acts as a source of nutrients, which seem to support the important development of phytoplankton and nitrification activity recorded in the surface water. Bottom processes could be related to the advanced degree and efficiency of the treatment, the temperature, and probably the strong and frequent wind present in the region.

  13. Modeling nutrient transports and exchanges of nutrients between shallow regions and the open Baltic sea in present and future climate.

    PubMed

    Eilola, Kari; Rosell, Elin Almroth; Dieterich, Christian; Fransner, Filippa; Höglund, Anders; Meier, H E Markus

    2012-09-01

    We quantified horizontal transport patterns and the net exchange of nutrients between shallow regions and the open sea in the Baltic proper. A coupled biogeochemical-physical circulation model was used for transient simulations 1961-2100. The model was driven by regional downscaling of the IPCC climate change scenario A1B from two global General Circulation Models in combination with two nutrient load scenarios. Modeled nutrient transports followed mainly the large-scale internal water circulation and showed only small circulation changes in the future projections. The internal nutrient cycling and exchanges between shallow and deeper waters became intensified, and the internal removal of phosphorus became weaker in the warmer future climate. These effects counteracted the impact from nutrient load reductions according to the Baltic Sea Action Plan. The net effect of climate change and nutrient reductions was an increased net import of dissolved inorganic phosphorus to shallow areas in the Baltic proper.

  14. Models for nutrition education to increase consumption of calcium and dairy products among African Americans.

    PubMed

    Bronner, Yvonne L; Hawkins, Anita S; Holt, Mckessa L; Hossain, Mian B; Rowel, Randolph H; Sydnor, Kim L; Divers, Shaquana P

    2006-04-01

    Calcium and dairy consumption are documented to be low among African Americans and have demonstrated benefits to bone growth, overall nutritional status, and health throughout the life cycle. There is also an emerging relationship to the prevention of obesity. This low consumption has been attributed to both cultural and community/environmental barriers. Using a life course construct and an ecological model of health behavior, this paper will illustrate why nutrition education and food consumption behavior at one stage of the life cycle may influence health status at that stage as well as influence health and consumption of calcium and dairy products at subsequent stages. The life course construct recognizes that both past and present behavior and experiences (in this case food and nutrient intake) are shaped by the wider social, economic, and cultural context and therefore may provide clues to current patterns of health and disease. The ecological model, concerned with constructs of environmental change, behavior, and policies that may help people make choices in their daily life, complements the life course approach when examining the potential influence of nutrition education provided by federally funded food and nutrition programs on calcium and dairy consumption behavior across the life cycle. The "critical period model" within the life course construct is operative for calcium, a nutrient for which adequate intake is critically important during adolescence when peak bone density development, necessary for later protection against osteoporosis, is important.

  15. Understanding and Changing Food Consumption Behavior Among Children: The Comprehensive Child Consumption Patterns Model.

    PubMed

    Jeffries, Jayne K; Noar, Seth M; Thayer, Linden

    2015-01-01

    Current theoretical models attempting to explain diet-related weight status among children center around three individual-level theories. Alone, these theories fail to explain why children are engaging or not engaging in health-promoting eating behaviors. Our Comprehensive Child Consumption Patterns model takes a comprehensive approach and was developed specifically to help explain child food consumption behavior and addresses many of the theoretical gaps found in previous models, including integration of the life course trajectory, key influencers, perceived behavioral control, and self-regulation. Comprehensive Child Consumption Patterns model highlights multiple levels of the socioecological model to explain child food consumption, illustrating how negative influence at multiple levels can lead to caloric imbalance and contribute to child overweight and obesity. Recognizing the necessity for multi-level and system-based interventions, this model serves as a template for holistic, integrated interventions to improve child eating behavior, ultimately impacting life course health development.

  16. Consumption of 'extra' foods by Australian children: types, quantities and contribution to energy and nutrient intakes.

    PubMed

    Rangan, A M; Randall, D; Hector, D J; Gill, T P; Webb, K L

    2008-03-01

    To measure the types and quantities of energy-dense, nutrient-poor 'extra' foods consumed by Australian children and adolescents and their contribution to total energy and nutrient intakes. We used data from 3007 children, aged 2-18 years, who participated in the nationally representative 1995 National Nutrition Survey. Intake was determined by 24-h recall and 'extra' foods were defined using principles outlined in the Australian Guide to Healthy Eating (AGHE) and by applying cut points for maximum amounts of fat and sugar within each food category. All children (99.8%) consumed at least one 'extra' food and the most commonly consumed were margarine, sugar-sweetened soft drinks, cordials and sugar. 'Extra' foods contributed 41% of daily energy intake. Those foods contributing most to energy intake were fried potatoes (4.2%), sugar-sweetened soft drinks (3.3%), ice cream/ice confection (3.1%) and cordials (2.7%). Age and sex were important determinants of 'extra' food intake, with males and older children generally consuming more and different types of, 'extra' foods than females and younger children. 'Extra' foods contributed 19% protein, 47% total fat, 47% saturated fat, 54% sugar, and approximately 20-25% of selected micronutrients to the diet. Calcium and zinc intakes from core foods were below 70% of the recommended dietary intakes for adolescent girls. 'Extra' foods are over-consumed at two to four times the recommended limits and contribute excessively to the energy, fat and sugar intakes of Australian children, while providing relatively few micronutrients. This is of concern in terms of children's weight and nutrient status.

  17. An electricity consumption model for electric vehicular flow

    NASA Astrophysics Data System (ADS)

    Xiao, Hong; Huang, Hai-Jun; Tang, Tie-Qiao

    2016-09-01

    In this paper, we apply the relationships between the macro and micro variables of traffic flow to develop an electricity consumption model for electric vehicular flow. We use the proposed model to study the quantitative relationships between the electricity consumption/total power and speed/density under uniform flow, and the electricity consumptions during the evolution processes of shock, rarefaction wave and small perturbation. The numerical results indicate that the proposed model can perfectly describe the electricity consumption for electric vehicular flow, which shows that the proposed model is reasonable.

  18. Modeled summer background concentration nutrients and ...

    EPA Pesticide Factsheets

    We used regression models to predict background concentration of four water quality indictors: total nitrogen (N), total phosphorus (P), chloride, and total suspended solids (TSS), in the mid-continent (USA) great rivers, the Upper Mississippi, the Lower Missouri, and the Ohio. From best-model linear regressions of water quality indicators with land use and other stressor variables, we determined the concentration of the indicators when the land use and stressor variables were all set to zero the y-intercept. Except for total P on the Upper Mississippi River and chloride on the Ohio River, we were able to predict background concentration from significant regression models. In every model with more than one predictor variable, the model included at least one variable representing agricultural land use and one variable representing development. Predicted background concentration of total N was the same on the Upper Mississippi and Lower Missouri rivers (350 ug l-1), which was much lower than a published eutrophication threshold and percentile-based thresholds (25th percentile of concentration at all sites in the population) but was similar to a threshold derived from the response of sestonic chlorophyll a to great river total N concentration. Background concentration of total P on the Lower Missouri (53 ug l-1) was also lower than published and percentile-based thresholds. Background TSS concentration was higher on the Lower Missouri (30 mg l-1) than the other ri

  19. Modeling of nutrient concentrations in the river Loktinka, Western Siberia

    NASA Astrophysics Data System (ADS)

    Sheludkov, Artyom; Kiesel, Jens; Veshkurtseva, Tatyana

    2014-05-01

    Nutrient pollution is the process where too many nutrients, mainly nitrogen and phosphorus, are added to bodies of water and act as fertilizer, causing excessive growth of algae and threatening the natural species assemblages. The investigated catchment area is the river Loktinka which is located in the southern part of the West Siberian Plain, in the forest-steppe vegetation region. One of the most serious contaminant of the surface waters in the region are nutrients. The main input of nutrients comes from untreated runoff from agricultural fields and pastures. To mitigate agricultural non-point source pollution, simulation tools can aid in the development of temporal and spatial management plans. This study presents a software application of a Geohydrological Analysis Model, developed by Prof. Kalinin, Tyumen State University, Russian Federation (1998) for the region. The model is based on "Runoff Forming Surfaces", which are a distinguished part of the catchment characterized by a set of natural components such as land use, soil and elevation. These areas are relatively homogeneous and lead to the same parameters for representing the hydrological cycle. The model is used to simulate the water quality situation which was sampled during spring runoff in 2013. Results of the Siberian Geohydrological Analysis Model are compared to simulations carried out with the Soil and Water Assessment Tool (SWAT).

  20. Nutrient Dynamics in Flooded Wetlands. II: Model Application

    EPA Science Inventory

    In this paper we applied and evaluated the wetland nutrient model described in an earlier paper. Hydrologic and water quality data from a small restored wetland located on Kent Island, Maryland, which is part of the Delmarva Peninsula on the Eastern shores of the Chesapeake Bay...

  1. Nutrient Dynamics in Flooded Wetlands. II: Model Application

    EPA Science Inventory

    In this paper we applied and evaluated the wetland nutrient model described in an earlier paper. Hydrologic and water quality data from a small restored wetland located on Kent Island, Maryland, which is part of the Delmarva Peninsula on the Eastern shores of the Chesapeake Bay...

  2. Adequate nutrient intakes are associated with traditional food consumption in nunavut inuit children aged 3-5 years.

    PubMed

    Johnson-Down, Louise; Egeland, Grace M

    2010-07-01

    Dietary habits among Arctic preschoolers are unknown. A cross-sectional health survey of 388 Inuit, aged 3-5 y, was conducted in 16 communities in Canada's Nunavut Territory. Twenty-four-hour recall and FFQ with parents and primary caregivers quantified diet from market and traditional foods (TF). The Institute of Medicine's Dietary Reference Intakes estimated adequacy comparing intakes with Estimated Average Requirement or Adequate Intakes (AI). High-sugar and high-fat food and sugar beverage consumption and the extent to which dietary habits followed the Canadian Food Guide were evaluated. The children's mean age was 4.4 +/- 0.9 y and the mean BMI percentile was 90.2%. Consumption of nutrient-poor and energy-dense food and beverages contributed to 35% of energy. Most children met the requirements for many nutrients despite not eating the recommended servings from Eating Well with Canada's Food Guide First Nations, Inuit and Métis. Higher intake of TF resulted in higher intakes of cholesterol, vitamins A and D, iron, magnesium, and zinc. The percent above the AI for vitamin D was 43.1, 56.8, and 83.2% among no, low, and high TF consumers, respectively (chi2 test; P-trend < 0.0001). Dietary habits indicate a population at risk for overweight, obesity, and tooth decay. Interventions should encourage TF, including plant-based TF; healthy market food choices, including fruit and vegetables; and milk or alternative sources of vitamin D and calcium and discourage unhealthy market food choices.

  3. Dynamic investigation of nutrient consumption and injection strategy in microbial enhanced oil recovery (MEOR) by means of large-scale experiments.

    PubMed

    Song, Zhiyong; Zhu, Weiyao; Sun, Gangzheng; Blanckaert, Koen

    2015-08-01

    Microbial enhanced oil recovery (MEOR) depends on the in situ microbial activity to release trapped oil in reservoirs. In practice, undesired consumption is a universal phenomenon but cannot be observed effectively in small-scale physical simulations due to the scale effect. The present paper investigates the dynamics of oil recovery, biomass and nutrient consumption in a series of flooding experiments in a dedicated large-scale sand-pack column. First, control experiments of nutrient transportation with and without microbial consumption were conducted, which characterized the nutrient loss during transportation. Then, a standard microbial flooding experiment was performed recovering additional oil (4.9 % Original Oil in Place, OOIP), during which microbial activity mostly occurred upstream, where oil saturation declined earlier and steeper than downstream in the column. Subsequently, more oil remained downstream due to nutrient shortage. Finally, further research was conducted to enhance the ultimate recovery by optimizing the injection strategy. An extra 3.5 % OOIP was recovered when the nutrients were injected in the middle of the column, and another additional 11.9 % OOIP were recovered by altering the timing of nutrient injection.

  4. Following federal guidelines to increase nutrient consumption may lead to higher food costs for consumers

    PubMed Central

    Monsivais, Pablo; Aggarwal, Anju; Drewnowski, Adam

    2014-01-01

    The 2010 Dietary Guidelines Advisory Committee emphasized the need to increase dietary intakes of potassium, dietary fiber, vitamin D, and calcium. Examining the economic impact of increasing intakes of these nutrients to recommended levels among adults in King County, Washington, we found that each increase in intake of potassium, dietary fiber, and vitamin D equal to 10 percent of the daily target intake significantly increased food costs to consumers. At the same time, each time consumers obtained 1 percent more of their daily calories from added fats and added sugars, their food costs significantly declined. These findings suggest that many consumers, especially those with little budget flexibility, will need assistance to adopt healthier diets consistent with federal goals. PMID:21813865

  5. Nutrient intake and food group consumption of 10-year-olds by sugar intake level: the Bogalusa Heart Study.

    PubMed

    Farris, R P; Nicklas, T A; Myers, L; Berenson, G S

    1998-12-01

    The effect of total sugar intake on nutrient intake and food group consumption was examined in children. Twenty-four hour dietary recalls were collected on a sample of 568 ten-year-olds from two cross-sectional surveys. The population was stratified according to total sugar intake quartiles: < or = 25th (46 g/1000 kcal), 25-50th (67 g/1000 kcal), 50-75th (81 g/1000 kcal) and > or = 75th (106 g/1000 kcal). No significant difference was shown in energy intakes across the quartiles and no significant race or gender differences were observed in mean total sugar intakes. However, with increasing total sugar intake, there was a significant linear decrease in mean intakes of protein, fat, saturated fat, starch, cholesterol, sodium, vitamins B6 and E, thiamin, niacin, iron, and zinc; and a significant linear increase in mean intakes of carbohydrate, fructose, lactose, sucrose, vitamin D, and calcium. Eating patterns reflected the differing nutrient intakes, with high sugar consumers having significantly higher intakes of total g of candy, beverages and milk and lower intakes of total g of meats, and cheese than lower sugar consumers. The nutritional quality of children's diets high in total sugar appear to be adequate regarding vitamin and mineral intakes and are closer to meeting current dietary fat recommendations.

  6. Evaluation of the Relative Validity of the Short Diet Questionnaire for Assessing Usual Consumption Frequencies of Selected Nutrients and Foods

    PubMed Central

    Shatenstein, Bryna; Payette, Hélène

    2015-01-01

    A 36-item Short Diet Questionnaire (SDQ) was developed to assess usual consumption frequencies of foods providing fats, fibre, calcium, vitamin D, in addition to fruits and vegetables. It was pretested among 30 community-dwelling participants from the Québec Longitudinal Study on Nutrition and Successful Aging, “NuAge” (n = 1793, 52.4% women), recruited in three age groups (70 ± 2 years; 75 ± 2 years; 80 ± 2 years). Following revision, the SDQ was administered to 527 NuAge participants (55% female), distributed among the three age groups, both sexes and languages (French, English) prior to the second of three non-consecutive 24 h diet recalls (24HR) and validated relative to the mean of three 24HR. Full data were available for 396 participants. Most SDQ nutrients and fruit and vegetable servings were lower than 24HR estimates (p < 0.05) except calcium, vitamin D, and saturated and trans fats. Spearman correlations between the SDQ and 24HR were modest and significant (p < 0.01), ranging from 0.19 (cholesterol) to 0.45 (fruits and vegetables). Cross-classification into quartiles showed 33% of items were jointly classified into identical quartiles of the distribution, 73% into identical and contiguous quartiles, and only 7% were frankly misclassified. The SDQ is a reasonably accurate, rapid approach for ranking usual frequencies of selected nutrients and foods. Further testing is needed in a broader age range. PMID:26247965

  7. Contribution of beef consumption to nutrient intake, diet quality, and food patterns in the diets of the US population.

    PubMed

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

    2012-01-01

    This study examined the association between the nutrient contribution of beef, in its lowest and highest fat forms, and diet quality and food patterns in individuals 4+years of age. Beef consumers were categorized into three groups (lowest lean/highest fat [LLHF]; middle lean/middle fat content; and highest lean/lowest fat [HLLF]) based on the lean and fat content of beef consumed. Compared to non-beef consumers, HLLF consumers had higher intakes of vitamins B(6) and B(12), iron, zinc, and potassium. Non-beef consumers had higher intakes of thiamin, folate, calcium, and magnesium than HLLF beef consumers. The HLLF group had significantly higher intakes of vitamins A, C, B(6), and B(12); niacin; phosphorus; magnesium; iron; zinc; and potassium, protein and lower intakes of total energy; total fat; SFA; MUFA; total carbohydrates. There was no difference in diet quality between HLLF beef consumers and non-beef consumers. Moderate consumption of lean beef contributes to intakes of selected nutrients and diet quality was similar to non-beef consumers.

  8. Evaluation of the Relative Validity of the Short Diet Questionnaire for Assessing Usual Consumption Frequencies of Selected Nutrients and Foods.

    PubMed

    Shatenstein, Bryna; Payette, Hélène

    2015-08-04

    A 36-item Short Diet Questionnaire (SDQ) was developed to assess usual consumption frequencies of foods providing fats, fibre, calcium, vitamin D, in addition to fruits and vegetables. It was pretested among 30 community-dwelling participants from the Québec Longitudinal Study on Nutrition and Successful Aging, "NuAge" (n = 1793, 52.4% women), recruited in three age groups (70 ± 2 years; 75 ± 2 years; 80 ± 2 years). Following revision, the SDQ was administered to 527 NuAge participants (55% female), distributed among the three age groups, both sexes and languages (French, English) prior to the second of three non-consecutive 24 h diet recalls (24HR) and validated relative to the mean of three 24HR. Full data were available for 396 participants. Most SDQ nutrients and fruit and vegetable servings were lower than 24HR estimates (p < 0.05) except calcium, vitamin D, and saturated and trans fats. Spearman correlations between the SDQ and 24HR were modest and significant (p < 0.01), ranging from 0.19 (cholesterol) to 0.45 (fruits and vegetables). Cross-classification into quartiles showed 33% of items were jointly classified into identical quartiles of the distribution, 73% into identical and contiguous quartiles, and only 7% were frankly misclassified. The SDQ is a reasonably accurate, rapid approach for ranking usual frequencies of selected nutrients and foods. Further testing is needed in a broader age range.

  9. Antioxidant capacity total in non-melanoma skin cancer and its relationship with food consumption of antioxidant nutrients.

    PubMed

    Freitas, Betânia e Silva de Almendra; de Castro, Laís Lima; Aguiar, Jordana Rayane Sousa; de Araújo, Camila Guedes Borges; Visacri, Marília Berlofa; Tuan, Bruna Taliani; Pincinato, Eder de Carvalho; Moriel, Patricia

    2015-04-01

    The non-melanoma skin cancer is the most common cancer and accounts for more than half of the diagnoses of cancer, and basal cell carcinoma (BCC), the most frequent cutaneous neoplasm, corresponding to 70-80% of cutaneous tumors. Oxidative stress is an important trigger for skin carcinogenesis. Thus, it is important to evaluate oxidative stress, in order to discern effective therapeutic strategies able to stop it or attenuate it, thereby prevent the installation of non-melanoma skin cancer. Cross-sectional study with controls, involving 84 individuals of both sexes aged between 38-84 years, divided into two groups: control group of healthy people(n = 24) and the case group included individuals who presented non-melanoma skin and they have undergoing surgery (n = 60). The blood samples of the individuals were obtained for evaluation of biomarkers of oxidative stress (F2-isoprostane, nitrite, thiobarbituric acid reactive substances (TBARS) and total antioxidant capacity). The usual dietary intake and nutritional status of the subjects were evaluated. The significance level for this study was 5%. Patients in the case group had higher serum concentrations of biomarkers of oxidative stress, F2-isoprostane concentrations were significantly higher compared to controls. The results showed high rates of overweight and obesity in the case and control groups. The dietary concentrations of antioxidant minerals zinc, copper and selenium in the case group were significantly lower compared to controls. The correlation between markers of oxidative stress and dietary concentrations of antioxidant nutrients showed the influence of food intake of vitamins A and E in reducing oxidative stress, since these nutrients behave as important antioxidants, acting as sweepers of RL, by removing of the body the negative effects on the redox balance of the skin. We emphasize the importance of adopting healthy eating habits that optimize the consumption of antioxidant nutrients as a strategy to

  10. Modeling seasonal export and retention of nutrients in european catchments.

    NASA Astrophysics Data System (ADS)

    de Klein, J.

    2003-04-01

    In the abatement of eutrophication of standing waters management of sources and transport of nutrients in river catchments is crucial. However the transport of nitrogen and phosphorus can vary significantly among (sub) catchments as a result of different physical, chemical and biotic factors. Qualitative and quantitative differences in nutrient pathways within catchments hamper the application of common standards and reliable prediction of the effect of nutrient loads. The EU-project BUFFER is set up to provide a tool which describes the relation between catchment properties and activities resulting in nutrient loads on one hand, and the ecological state of the receiving lakes on the other hand. To support this a new model-concept is developed that describes the transport and retention of nutrients in running waters (De Klein, 2002). The calculation requires minimum input data and generates output on a seasonal basis. The model was so far applied to Dutch catchments. This paper presents the extension and verification of the model, based on data of intensively studied catchments within the BUFFER-project. This implies the method can be applied to a wider range of European catchments. Basic model inputs are total annual loads of nutrients from point and diffuse sources to the surface (head) waters. During transport nutrients are retained in the catchment. Retention coefficients vary over the seasons and are calculated from a) residence time, which can be approximated using rainfall data, size of drainage basin and morphological properties b) temperature. The model outputs retention and export from the catchment on a monthly basis, using a set of straightforward formulas. Coefficients are calibrated with a subset of the measured data in an optimization routine, and subsequently verified. The similarity of measured and calculated values was high (r2 > 0.8; p<0.01). With a rather simple calculation method with few input data it is possible to estimate monthly export

  11. Trends in food consumption and nutrient intake in Germany between 2006 and 2012: results of the German National Nutrition Monitoring (NEMONIT).

    PubMed

    Gose, Maria; Krems, Carolin; Heuer, Thorsten; Hoffmann, Ingrid

    2016-04-01

    The German National Nutrition Monitoring (NEMONIT) is a longitudinal and nationwide study to assess changes in food consumption and nutrient intake in Germany. A sample of 1840 participants (baseline age: 14-80 years) was drawn from the nationally representative German National Nutrition Survey (NVS) II (2005-2007). The participants have been interviewed by telephone annually since 2008. Food consumption was assessed by two 24-h recalls in the NVS II and the 4 years of NEMONIT (2008-2012/2013), respectively. Energy and nutrient intakes were calculated using the German Nutrient Database 3.02. Diet quality was evaluated using the Healthy Eating Index-NVS (HEI-NVS) II. Time trends were analysed by generalised estimating equation. Consumption of fruit/fruit products and fruit juice/nectar among men and women decreased, whereas consumption of water, soft drinks and coffee/tea increased over the 6-year period. Furthermore, increased consumption of confectionery and animal fats was observed among women. HEI-NVS II did not change since NVS II in both sexes. There were no changes in energy and protein intakes, but carbohydrate intake declined while fat intake increased over time. Regarding micronutrients, a decreasing intake of thiamin, riboflavin and vitamin B6 was observed in both sexes, but intake of Mg, Fe and niacin increased among women over time. In conclusion, food consumption and nutrient intake remained relatively stable between 2005-2007 and 2012/2013 within this German cohort. A few favourable and unfavourable changes were observed. Compared with national dietary guidelines, consumption of food of plant origin remained too low and consumption of meat/meat products remained too high in Germany.

  12. Food Consumption and Nutrient Intake by Children Aged 10 to 48 Months Attending Day Care in The Netherlands.

    PubMed

    Goldbohm, R Alexandra; Rubingh, Carina M; Lanting, Caren I; Joosten, Koen F M

    2016-07-14

    The diet of young children is an important determinant of long-term health effects, such as overweight and obesity. We analyzed two-day food consumption records from 1526 young children (10-48 months old) attending 199 daycare centers across The Netherlands. Data were observed and recorded in diaries by caregivers at the day nursery and by parents at home on days that the children attended the daycare center. According to national and European reference values, the children had an adequate nutrient intake with exception of low intakes of total fat, n-3 fatty acids from fish and possibly iron. Intakes of energy and protein were substantially higher than recommended and part of the population exceeded the tolerable upper intake levels for sodium, zinc and retinol. Consumption of fruit, fats, fish, and fluids was substantially less than recommended. The children used mostly (semi-)skimmed milk products and non-refined bread and cereals, as recommended. Two thirds of the consumed beverages, however, contained sugar and contributed substantially to energy intake. In young children, low intakes of n-3 fatty acids and iron are a potential matter of concern, as are the high intakes of energy, protein, sugared beverages, and milk, since these may increase the risk of becoming overweight.

  13. Food Consumption and Nutrient Intake by Children Aged 10 to 48 Months Attending Day Care in The Netherlands

    PubMed Central

    Goldbohm, R. Alexandra; Rubingh, Carina M.; Lanting, Caren I.; Joosten, Koen F. M.

    2016-01-01

    The diet of young children is an important determinant of long-term health effects, such as overweight and obesity. We analyzed two-day food consumption records from 1526 young children (10–48 months old) attending 199 daycare centers across The Netherlands. Data were observed and recorded in diaries by caregivers at the day nursery and by parents at home on days that the children attended the daycare center. According to national and European reference values, the children had an adequate nutrient intake with exception of low intakes of total fat, n-3 fatty acids from fish and possibly iron. Intakes of energy and protein were substantially higher than recommended and part of the population exceeded the tolerable upper intake levels for sodium, zinc and retinol. Consumption of fruit, fats, fish, and fluids was substantially less than recommended. The children used mostly (semi-)skimmed milk products and non-refined bread and cereals, as recommended. Two thirds of the consumed beverages, however, contained sugar and contributed substantially to energy intake. In young children, low intakes of n-3 fatty acids and iron are a potential matter of concern, as are the high intakes of energy, protein, sugared beverages, and milk, since these may increase the risk of becoming overweight. PMID:27428995

  14. Models for predicting fuel consumption in sagebrush-dominated ecosystems

    Treesearch

    Clinton S. Wright

    2013-01-01

    Fuel consumption predictions are necessary to accurately estimate or model fire effects, including pollutant emissions during wildland fires. Fuel and environmental measurements on a series of operational prescribed fires were used to develop empirical models for predicting fuel consumption in big sagebrush (Artemisia tridentate Nutt.) ecosystems....

  15. Modelling and simulation of nutrient dispersion from coated fertilizer granules

    NASA Astrophysics Data System (ADS)

    Razali, Radzuan; Daud, Hanita; Nor, Shafiq Mohd.

    2014-10-01

    The usage of Controlled-Release Fertilizer (CRF) is essential in plants and crops to fulfill the need and requirement for the modern agriculture which now feeds 6 billion people. Therefore modeling and simulation of nutrient release from coated fertilizer has become the best method to study the behavior of some parameters toward water saturation in and nutrient release from the coated-fertilizer granule. This paper is the improvement development of modeling and computer simulation by Basu [1] which include some of the factors affecting the water saturation time and nutrient release time from a coated-fertilizer. The effect of granule radius, the diffusivity of water and nutrient, the temperature of surrounding, the contact areas and the characteristic of the coating are studied and the simulation was developed using MATLAB software. The studies and understanding of this project is very important and useful especially to determine the important parameters in the manufacturing process of the coated-fertilizer granule and also will be useful for the farmers/users in the selection of the best fertilizers for their crops.

  16. Food supply versus household survey data: nutrient consumption trends for Spain, 1958-1988.

    PubMed

    Rodríguez-Artalejo, F; Banegas, J R; Graciani, A; Hernández-Vecino, R; del Rey-Calero, J

    1996-08-01

    Various methods of estimating food consumption, such as food balance sheets (FBS) and household surveys (HS), have been developed over the years and have been used to inform, monitor and evaluate nutrition policies. Because these methods vary in their objectives and data collection procedures, the objective of this study has been to elaborate FBS data for Spain and to study the consistency of fat, carbohydrate and protein intake trends, as measured by FBS and HS, for the period 1958 to 1988. Food balance sheets were elaborated by the authors according to the methodology of FAO using all available data sources for the 1958-1988 period. This data considered every major food item contributing to the total energy intake of the spanish population. Household survey data were taken from three similar national household budget surveys carried out on a representative sample of the Spanish population in 1958, 1964-1965, and 1980-1981. Estimates of food consumption were transformed into macronutrient intake by applying standard food tables. When macronutrient intake were expressed in absolute amounts, an unexpected finding was the tendency of the household surveys to overestimate food balance sheet data for fat, and to a lesser extent protein and carbohydrate, intake during the first years in the series. Also, the slopes of the trends of macronutrient intake were significantly (p < 0.05) greater for food balance sheets than for household survey data, specially for fat. When macronutrient intake were expressed as percent of total energy, differences between the two types of data tended to diminish and heterogeneity of slopes disappeared. We conclude that household survey and food supply data provide partially different information on macronutrient intake trends in the Spanish population for the period 1958-1988. The discrepancy is particularly noticeable for fat intake and when data are expressed in absolute amounts.

  17. A USAF Energy Consumption Projection Model

    DTIC Science & Technology

    1974-11-01

    almost 4 percent of the total U.S. petrol- eum consumption was used by the DoD, including 53 percent of the total U.S. jet fuel consumption. Of this...PRdGRAM C HINTER TD 7FRn. MPRDr, = o START OF PROGRAM | nnP. REAd PROGRAM MAMF CARO. «0 Rf-AD ( b, SO) (PROG) I ) , I = I , 1R) PRINT...IIn r.ON’TiMHF Reproduced from best available copy. ■ .J ^ -46- C c c c Sf1! PRllGHA^i PLFM^NJT CHllNTftH Td ZF^O. NPLl-M

  18. Consumption of various forms of apples is associated with a better nutrient intake and improved nutrient adequacy in diets of children: National Health and Nutrition Examination Survey 2003–2010

    PubMed Central

    Nicklas, Theresa A.; O'Neil, Carol E.; Fulgoni, Victor L.

    2015-01-01

    Background Consumption of fruit has been associated with a variety of health benefits, yet, 75% of children have usual intakes of total fruit below minimum recommended amounts. Apples are the second most commonly consumed fruit in the United States; however, no studies have examined the impact of apple consumption on nutrient intake and adequacy in children's diets. Objective The purpose of this study is to examine the association between apple (various forms) consumption with nutrient intake and nutrient adequacy in a nationally representative sample of children. Design Participants were children aged 2–18 years (n=13,339), from the National Health and Nutrition Examination Survey 2003–2010. Least square means of total energy and nutrient intake, and the percentage of the population below the estimated average requirement (EAR) or above the adequate intake (AI) among apple consumers and non-consumers were examined. Results Consumers of total apple products had higher (p<0.01) total intakes of fiber, magnesium, and potassium and lower intakes of total fat, saturated fatty acids, monounsaturated fatty acid, and sodium than non-consumers. Apple consumers had higher (p<0.01) total sugar intake, but lower intake of added sugars compared to non-consumers. A lower (p<0.01) percentage of apple consumers were below the EAR for 13 of the 16 nutrients studied. Apple consumers had approximately a 10 percentage unit difference below the EAR for calcium and magnesium, and vitamins A, C, D, and E, than non-consumers. The percentage above the AI for fiber was significantly (p<0.0001) higher among total apple consumers (6.24±0.45 g) compared to non-consumers (0.57±0.07 g). The results were similar for individual apple products (i.e. apple juice, applesauce, and whole apples). Conclusion Consumption of any forms of apples provided valuable nutrients in the diets of children. PMID:26445211

  19. Statistical modelling of variability in sediment-water nutrient and oxygen fluxes

    NASA Astrophysics Data System (ADS)

    Serpetti, Natalia; Witte, Ursula; Heath, Michael

    2016-06-01

    Organic detritus entering, or produced, in the marine environment is re-mineralised to inorganic nutrient in the seafloor sediments. The flux of dissolved inorganic nutrient between the sediment and overlying water column is a key process in the marine ecosystem, which binds the biogeochemical sub-system to the living food web. These fluxes are potentially affected by a wide range of physical and biological factors and disentangling these is a significant challenge. Here we develop a set of General Additive Models (GAM) of nitrate, nitrite, ammonia, phosphate, silicate and oxygen fluxes, based on a year-long campaign of field measurements off the north-east coast of Scotland. We show that sediment grain size, turbidity due to sediment re-suspension, temperature, and biogenic matter content were the key factors affecting oxygen consumption, ammonia and silicate fluxes. However, phosphate fluxes were only related to suspended sediment concentrations, whilst nitrate fluxes showed no clear relationship to any of the expected drivers of change, probably due to the effects of denitrification. Our analyses show that the stoichiometry of nutrient regeneration in the ecosystem is not necessarily constant and may be affected by combinations of processes. We anticipate that our statistical modelling results will form the basis for testing the functionality of process-based mathematical models of whole-sediment biogeochemistry.

  20. Improved diet quality, nutrient intake, and health associated with out-of-hand tree nut consumption in U.S. adults: NHANES 1999–2004

    USDA-ARS?s Scientific Manuscript database

    HANES (1999–2004), data were used to examine the association of out-of-hand tree nut consumption (almonds, Brazil nuts, cashews, filberts, macadamias, pecans, pine nuts, pistachios, and walnuts) with diet quality, nutrient intakes, and health risks in adults 19+ yrs (n equals 13,292). Using 24 hour ...

  1. Out-of-hand nut consumption is associated with improved nutrient intake and health risk markers in US children and adults: NHANES 1999-2004

    USDA-ARS?s Scientific Manuscript database

    The purpose of this study was to determine the association of out-of-hand nut (OOHN) consumption with nutrient intake, diet quality, and the prevalence of risk factors for cardiovascular disease and metabolic syndrome. Data from 24-hour recalls from individuals aged 2+ years (n = 24,385) participati...

  2. 100% Orange juice consumption is associated with better diet quality, improved nutrient adequacy, decreased risk for obesity, and improved biomarkers of health in adults

    USDA-ARS?s Scientific Manuscript database

    Consumption of 100% orange juice (OJ) has been positively associated with nutrient adequacy and diet quality, with no increased risk of overweight/obesity in children; however, no one has examined these factors in adults. The purpose of this study was to examine the association of 100% orange juice ...

  3. Cooked oatmeal consumption is associated with better diet quality, better nutrient intakes, and reduced risk for central adiposity and obesity in Children 2-18 years

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to assess the association between oatmeal consumption and nutrient intake, diet quality, and weight/adiposity of children aged 2-18. A nationally representative sample of children aged 2-18 (N=14,690) participating in National Health and Nutrition Examination Survey 2...

  4. Consumption of whole grains is associated with improved diet quality and nutrient intake in children and adolescents: the National Health and Nutrition Examination Survey 1999–2004

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to examine the association of consumption of whole grains (WG) with diet quality and nutrient intake in children and adolescents by a secondary analysis of cross-sectional data. The 1999-2004 National Health and Nutrition Examination Survey was used to study children ...

  5. Fruit juice consumption is associated with improved nutrient adequacy in children and adolescents: The National Health and Nutrition Examination Survey (NHANES) 2003-2006

    USDA-ARS?s Scientific Manuscript database

    The goal of the study was to examine the contribution of 100% fruit juice consumption to dietary adequacy of shortfall nutrients by children and adolescents. This was a cross-sectional study and used data from the 2003–2006 National Health and Nutrition Examination Survey (NHANES). Participants were...

  6. Consumption of 100% fruit juice is associated with better nutrient intake and diet quality but not with weight status in children: NHANES 2007-2010

    USDA-ARS?s Scientific Manuscript database

    This study examined the impact of various levels of 100% fruit juice (FJ) consumption on intake of nutrients, diet quality, and weight in children using the more recent national data. We conducted a cross-sectional study examining the data from children 2-18 years of age (n=6,090). Intake of nutrien...

  7. Millennial-scale variability in dust deposition, marine export production, and nutrient consumption in the glacial subantarctic ocean (Invited)

    NASA Astrophysics Data System (ADS)

    Martinez-Garcia, A.; Sigman, D. M.; Anderson, R. F.; Ren, H. A.; Hodell, D. A.; Straub, M.; Jaccard, S.; Eglinton, T. I.; Haug, G. H.

    2013-12-01

    Based on the limitation of modern Southern Ocean phytoplankton by iron and the evidence of higher iron-bearing dust fluxes to the ocean during ice ages, it has been proposed that iron fertilization of Southern Ocean phytoplankton contributed to the reduction in atmospheric CO2 during ice ages. In the Subantarctic zone of the Atlantic Southern Ocean, glacial increases in dust flux and export production have been documented, supporting the iron fertilization hypothesis. However, these observations could be interpreted alternatively as resulting from the equatorward migration of Southern Ocean fronts during ice ages if the observed productivity rise was not accompanied by an increase in major nutrient consumption. Here, new 230Th-normalized lithogenic and opal fluxes are combined with high-resolution biomarker measurements to reconstruct millennial-scale changes in dust deposition and marine export production in the subantarctic Atlantic over the last glacial cycle. In the same record foraminifera-bound nitrogen isotopes are used to reconstruct ice age changes in surface nitrate utilization, providing a comprehensive test of the iron fertilization hypothesis. Elevation in foraminifera-bound δ15N, indicating more complete nitrate consumption, coincides with times of surface cooling and greater dust flux and export production. These observations indicate that the ice age Subantarctic was characterized by iron fertilized phytoplankton growth. The resulting strengthening of the Southern Ocean's biological pump can explain the ~40 ppm lowering of CO2 that characterizes the transitions from mid-climate states to full ice age conditions as well as the millennial-scale atmospheric CO2 fluctuations observed within the last ice age

  8. Ecosystem Modeling Applied to Nutrient Criteria Development in Rivers

    NASA Astrophysics Data System (ADS)

    Carleton, James N.; Park, Richard A.; Clough, Jonathan S.

    2009-09-01

    Threshold concentrations for biological impairment by nutrients are difficult to quantify in lotic systems, yet States and Tribes in the United States are charged with developing water quality criteria to protect these ecosystems from excessive enrichment. The analysis described in this article explores the use of the ecosystem model AQUATOX to investigate impairment thresholds keyed to biological indexes that can be simulated. The indexes selected for this exercise include percentage cyanobacterial biomass of sestonic algae, and benthic chlorophyll a. The calibrated model was used to analyze responses of these indexes to concurrent reductions in phosphorus, nitrogen, and suspended sediment in an enriched upper Midwestern river. Results suggest that the indexes would respond strongly to changes in phosphorus and suspended sediment, and less strongly to changes in nitrogen concentration. Using simulated concurrent reductions in all three water quality constituents, a total phosphorus concentration of 0.1 mg/l was identified as a threshold concentration, and therefore a hypothetical water quality criterion, for prevention of both excessive periphyton growth and sestonic cyanobacterial blooms. This kind of analysis is suggested as a way to evaluate multiple contrasting impacts of hypothetical nutrient and sediment reductions and to define nutrient criteria or target concentrations that balance multiple management objectives concurrently.

  9. A modeling study examining the impact of nutrient boundaries ...

    EPA Pesticide Factsheets

    A mass balance eutrophication model, Gulf of Mexico Dissolved Oxygen Model (GoMDOM), has been developed and applied to describe nitrogen, phosphorus and primary production in the Louisiana shelf of the Gulf of Mexico. Features of this model include bi-directional boundary exchanges, an empirical site-specific light attenuation equation, estimates of 56 river loads and atmospheric loads. The model was calibrated for 2006 by comparing model output to observations in zones that represent different locations in the Gulf. The model exhibited reasonable skill in simulating the phosphorus and nitrogen field data and primary production observations. The model was applied to generate a nitrogen mass balance estimate, to perform sensitivity analysis to compare the importance of the nutrient boundary concentrations versus the river loads on nutrient concentrations and primary production within the shelf, and to provide insight into the relative importance of different limitation factors on primary production. The mass budget showed the importance of the rivers as the major external nitrogen source while the atmospheric load contributed approximately 2% of the total external load. Sensitivity analysis showed the importance of accurate estimates of boundary nitrogen concentrations on the nitrogen levels on the shelf, especially at regions further away from the river influences. The boundary nitrogen concentrations impacted primary production less than nitrogen concent

  10. A modeling study examining the impact of nutrient boundaries ...

    EPA Pesticide Factsheets

    A mass balance eutrophication model, Gulf of Mexico Dissolved Oxygen Model (GoMDOM), has been developed and applied to describe nitrogen, phosphorus and primary production in the Louisiana shelf of the Gulf of Mexico. Features of this model include bi-directional boundary exchanges, an empirical site-specific light attenuation equation, estimates of 56 river loads and atmospheric loads. The model was calibrated for 2006 by comparing model output to observations in zones that represent different locations in the Gulf. The model exhibited reasonable skill in simulating the phosphorus and nitrogen field data and primary production observations. The model was applied to generate a nitrogen mass balance estimate, to perform sensitivity analysis to compare the importance of the nutrient boundary concentrations versus the river loads on nutrient concentrations and primary production within the shelf, and to provide insight into the relative importance of different limitation factors on primary production. The mass budget showed the importance of the rivers as the major external nitrogen source while the atmospheric load contributed approximately 2% of the total external load. Sensitivity analysis showed the importance of accurate estimates of boundary nitrogen concentrations on the nitrogen levels on the shelf, especially at regions further away from the river influences. The boundary nitrogen concentrations impacted primary production less than nitrogen concent

  11. Modeling priming effects on microbial consumption of dissolved organic carbon in rivers

    NASA Astrophysics Data System (ADS)

    Hotchkiss, E. R.; Hall, R. O.; Baker, M. A.; Rosi-Marshall, E. J.; Tank, J. L.

    2014-05-01

    Rivers receive and process large quantities of terrestrial dissolved organic carbon (DOC). Biologically available (unstable) DOC leached from primary producers may stimulate (i.e., prime) the consumption of more stable terrestrially derived DOC by heterotrophic microbes. We measured microbial DOC consumption (i.e., decay rates) from contrasting C sources in 10 rivers in the western and Midwestern United States using short-term bioassays of river water, soil and algal leachates, glucose, and commercial humate. We added inorganic nutrients (ammonium and phosphorus) to a subset of bioassays. We also amended a subset of river, soil, and commercial humate bioassays with glucose or algal leachates to test the hypothesis that unstable DOC primes consumption of more stable DOC. We used prior measurements of source-specific DOC bioavailability, linked with a Bayesian process model, to estimate means and posterior probability distributions for source-specific DOC decay rates in multisource bioassays. Modeled priming effects ranged from a -130 to +370% change in more stable DOC decay when incubated with unstable DOC. Glucose increased modeled river DOC decay by an average of 87% among all rivers. Glucose and algal leachates increased soil leachate and commercial humate decay by an average of 25% above background rates. Inorganic nutrient additions did not have consistent effects on DOC decay, likely because most of the study rivers had high ambient background nutrients. Our results demonstrate that the priming effect can augment DOC decay in rivers. In addition, Bayesian models can be used to estimate mechanisms driving aquatic ecosystem processes that are difficult to measure directly.

  12. Modelling of the Nutrient Medium for Plants Cultivation in Spaceflight

    NASA Astrophysics Data System (ADS)

    Nechitailo, Galina S.

    2016-07-01

    MODELLING OF THE NUTRIENT MEDIUM FOR PLANTS CULTIVATION IN SPACEFLIGHT Nechitajlo G.S.*, Rakhmetova A.A.**, Bogoslovskaja O.A.**, Ol'hovskay I.P.**, Glushchenko N.N.** *Emanuel Institute of Biochemical Physics of Russian Academy of Sciences (IBCP RAS) mail: spacemal@mail.ru **V.L. Talrose Institute for Energy Problems of Chemical Physics of Russian Academy of Science (INEPCP RAS) mail: nnglu@ mail.ru The valuable life and fruitful activity of cosmonauts and researchers in conditions of spaceflights and prolonged work at space stations are only possible with creating life area providing fresh air, natural food, comfortable psychological conditions, etc. The solution of that problem under space conditions seems impossible without use of high nano- and biotechnologies for plants growth. A priority should be given not only to choose species of growth plants in space, but also to improve conditions for their growth which includes optimal nourishing components for plants, preparation of nutrient mediums, illumination and temperature. We are deeply convinced that just manipulations with growing conditions for cultivated plants, but not genes changes, is a guarantee of success in the decision of this problem. For improving the method of plants growing on the artificial nutrient medium with balanced content of components, being necessary for growth and development of plants, we added essential metal elements: Fe, Zn, Cu - in an electroneutral state in the form of nanoparticles instead of sulfates or other easily dissolving salts. Nanoparticulated metals are known to have a number of advantages in comparison with salts: metals in an electroneutral form are characterized with the prolonged and multifunctional action, low toxicity per se and appearing to be much below the toxicity of the same metals in the ionic forms, accumulation as a reserve being used in biotic dozes, active distribution in bodies and organs of plants and stimulation of vital processes. A high reactivity

  13. Consumption of bakery products, sweetened soft drinks and yogurt among children aged 6-7 years: association with nutrient intake and overall diet quality.

    PubMed

    Rodríguez-Artalejo, Fernando; García, Esther López; Gorgojo, Lydia; Garcés, Carmen; Royo, Miguel Angel; Martín Moreno, José María; Benavente, Mercedes; Macías, Alfonso; De Oya, Manuel

    2003-03-01

    The present study tests the hypothesis that higher consumption of bakery products, sweetened soft drinks and yogurt is associated with higher intake of energy, saturated fats, sugars and worse overall diet quality among Spanish children. This is a cross-sectional study covering 1112 children aged 6.0-7.0 years in four Spanish cities. Nutrient and food intake were obtained through a food-frequency questionnaire, and overall diet quality calculated using the healthy-eating index (HEI) developed by Kennedy et al. (1995). Standardized methods were used to measure anthropometric variables. Associations of interest were summarized as the difference in nutrient and food consumption between the value of the fifth and the first quintile of consumption (dq) of bakery products, sweetened soft drinks or yogurt, adjusted for energy intake and BMI. Bakery products, sweetened soft drinks and yogurt supplied 15.5, 1.0 and 5.6 % energy intake respectively. Higher consumption of these three foods was associated with greater energy intake (P<0.001), but not with higher BMI. Consumption of bakery products was associated with the proportion of energy derived from intake of total carbohydrates (dq 4.5 %, P<0.001) and sugars (dq 2 %, P<0.001), but did not show association with the HEI. Consumption of sweetened soft drinks was associated with a lower consumption of milk (dq -88 ml, P<0.001) and Ca (dq -175 mg/d, P<0.001), and worse HEI (dq -2, P<0.01). Consumption of yogurt, while associated with higher energy intake from saturated fats (dq 1.77 %, P<0.001) and sugars (dq 2.02 %, P<0.001), showed no association with the HEI. Differences in the intake of nutrients and foods across quintiles of consumption of bakery products, sweetened soft drinks and yogurt were usually very small. We conclude that the impact of the consumption of bakery products, sweetened soft drinks and yogurt on the quality of the diet of Spanish children is only modest, although it may contribute to aggravating

  14. A new compensated root water and nutrient uptake model implemented in HYDRUS programs

    NASA Astrophysics Data System (ADS)

    Simunek, Jiri; Hopmans, Jan W.; Lazarovitch, Naftali

    2010-05-01

    Plant root water and nutrient uptake is one of the most important processes in subsurface unsaturated flow and transport modeling, as root uptake controls actual plant evapotranspiration, water recharge and nutrient leaching to the groundwater. Root water uptake in unsaturated flow models is usually uncompensated and nutrient uptake is simulated assuming that all uptake is passive. We present a new compensated root water and nutrient uptake model, implemented in HYDRUS programs. The so-called root adaptability factor (Jarvis, 1989) is used to represent a threshold value above which reduced root water or nutrient uptake in water- or nutrient-stressed parts of the root zone is fully compensated for by increased uptake in other soil regions that are less stressed. Using a critical value of the water stress index, water uptake compensation is proportional to the water stress response function. Total root nutrient uptake is determined from the total of active and passive nutrient uptake. The partitioning between passive and active uptake is controlled by the a priori defined concentration value c_max. Passive nutrient uptake is simulated by multiplying root water uptake with the dissolved nutrient concentration, for soil solution concentration values below c_max. Passive nutrient uptake is thus zero when c_max is equal to zero. As the active nutrient uptake is obtained from the difference between plant nutrient demand and passive nutrient uptake (using Michaelis-Menten kinetics), the presented model thus implies that reduced passive nutrient uptake is compensated for by active nutrient uptake. In addition, the proposed root uptake model includes compensation for active nutrient uptake, in a similar way as used for root water uptake. The proposed root water and nutrient uptake model is demonstrated by several hypothetical and real examples, for plants supplied by water due to capillary rise from groundwater and surface drip irrigation.

  15. Modelling global nutrient retention by river damming: Phosphorus and silicon

    NASA Astrophysics Data System (ADS)

    Maavara, Taylor; Dürr, Hans; Van Cappellen, Philippe

    2014-05-01

    The phosphorus to silicon (P:Si) nutrient ratio is a key variable affecting ecosystem health in many aquatic environments. River damming represents a major anthropogenic perturbation of natural material flows along the aquatic continuum, with the potential to profoundly modify absolute and relative nutrient availabilities in surface waters. In this study, a multi-tiered approach for estimating global nutrient retention in man-made reservoirs is presented. We illustrate its application to the global riverine flux of reactive Si, using a database of dissolved reactive Si (DSi) budgets for 24 natural lakes and 22 artificial reservoirs. The database includes information on bedrock geology, surface water pH, water residence time, reservoir age and function, climate, and trophic status. Statistical analyses (ANOVA, t-test, PCA, linear plus non-linear regressions) are used to identify the best predictors of DSi retention and delineate how reservoir properties modulate nutrient dynamics. Results indicate that (1) reservoirs retain significantly less DSi than natural lakes, and (2) the water residence time, reservoir age and function (e.g., hydroelectrical production, irrigation, flood control) are the main system variables controlling DSi retention by dams. Next, a biogeochemical Si model is used to reproduce the previously derived statistical trends for DSi retention. Calibration of the model yields a relationship that enables one to predict annual in-reservoir siliceous productivity as a function of the external reactive Si supply. The model further accounts for the transition from reservoirs where reactive Si retention is primarily due to burial of allochtonous Si to those where in-reservoir DSi uptake by diatoms dominates. Finally, the statistical and mechanistic relationships are extrapolated to estimate that 25-28 Tg SiO2 yr-1 are retained worldwide by dams, or 7% of the annual reactive Si load to watersheds. We are currently applying the same multi-tiered approach

  16. National Diet and Nutrition Survey: UK food consumption and nutrient intakes from the first year of the rolling programme and comparisons with previous surveys

    PubMed Central

    Whitton, Clare; Nicholson, Sonja K; Roberts, Caireen; Prynne, Celia J; Pot, Gerda; Olson, Ashley; Fitt, Emily; Cole, Darren; Teucher, Birgit; Bates, Beverley; Henderson, Helen; Pigott, Sarah; Deverill, Claire; Swan, Gillian; Stephen, Alison M

    2011-01-01

    The National Diet and Nutrition Survey (NDNS) is a cross-sectional survey designed to gather data representative of the UK population on food consumption, nutrient intakes and nutritional status. The objectives of this paper were to identify and describe food consumption and nutrient intakes in the UK from the first year of the NDNS Rolling Programme (2008-09) and compare these with the 2000-01 NDNS of adults aged 19-64y and the 1997 NDNS of young people aged 4-18y. Differences in median daily food consumption and nutrient intakes between the surveys were compared by sex and age group (4-10y, 11-18y and 19-64y). There were no changes in energy, total fat or carbohydrate intakes between the surveys. Children 4-10y had significantly lower consumption of soft drinks (not low calorie), crisps and savoury snacks and chocolate confectionery in 2008-09 than in 1997 (all P< 0.0001). The percentage contribution of non-milk extrinsic sugars (NMES) to food energy was also significantly lower than in 1997 in children 4-10y (P< 0.0001), contributing 13.7-14.6% in 2008-09 compared with 16.8% in 1997. These changes were not as marked in older children and there were no changes in these foods and nutrients in adults. There was still a substantial proportion (46%) of girls 11-18y and women 19-64y (21%) with mean daily iron intakes below the Lower Reference Nutrient Intake (LRNI). Since previous surveys there have been some positive changes in intakes especially in younger children. However, further attention is required in other groups, in particular adolescent girls. PMID:21736781

  17. Spatial and seasonal variability of sediment oxygen consumption and nutrient fluxes at the sediment water interface in a sub-tropical lagoon (New Caledonia).

    PubMed

    Grenz, C; Denis, L; Pringault, O; Fichez, R

    2010-01-01

    In order to quantify the spatial and seasonal variations of sediment oxygen consumption and nutrient fluxes, we performed a spatial survey in the south west lagoon of New Caledonia during the two major seasons (dry and wet) based on a network of 11 sampling stations. Stations were selected along two barrier reef to land transects representing most types of sediments encountered in the lagoon. Fluxes were measured using ex-situ sediment incubations and compared to sediment characteristics. Sediment oxygen consumption (SOC) varied between 500 and 2000 micromol m(-2)h(-1), depending on season and stations. Nutrient effluxes from sediment were highly variable with highest fluxes measured in muddy sediments near the coast. Inter-sample variability was as high as seasonal differences so that no seasonally driven temperature effect could be observed on benthic nutrient fluxes in our temperature range. Nutrient fluxes, generally directed from the sediment to the water column, varied between -5.0 and 70.0 micromol m(-2)h(-1) for ammonia and between -2.5 and+12.5 micromol m(-2)h(-1) for PO(4) and NO(2+3). SOC and nutrient fluxes were compared to pelagic primary production rates in order to highlight the tight coupling existing between the benthic and pelagic compartments in this shallow tropical lagoon. Under specific occasions of low pelagic productivity, oxygen sediment consumption and related carbon and nutrient fluxes could balance nearly all net primary production in the lagoon. These biogeochemical estimates point to the functional importance of sediment biogeochemistry in the lagoon of New Caledonia. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  18. MODELING ENERGY EXPENDITURE AND OXYGEN CONSUMPTION IN HUMAN EXPOSURE MODELS: ACCOUNTING FOR FATIGUE AND EPOC

    EPA Science Inventory

    Human exposure and dose models often require a quantification of oxygen consumption for a simulated individual. Oxygen consumption is dependent on the modeled Individual's physical activity level as described in an activity diary. Activity level is quantified via standardized val...

  19. MODELING ENERGY EXPENDITURE AND OXYGEN CONSUMPTION IN HUMAN EXPOSURE MODELS: ACCOUNTING FOR FATIGUE AND EPOC

    EPA Science Inventory

    Human exposure and dose models often require a quantification of oxygen consumption for a simulated individual. Oxygen consumption is dependent on the modeled Individual's physical activity level as described in an activity diary. Activity level is quantified via standardized val...

  20. Modeling Antibiotic Tolerance in Biofilms by Accounting for Nutrient Limitation

    PubMed Central

    Roberts, Mark E.; Stewart, Philip S.

    2004-01-01

    A mathematical model of biofilm dynamics was used to investigate the protection from antibiotic killing that can be afforded to microorganisms in biofilms based on a mechanism of localized nutrient limitation and slow growth. The model assumed that the rate of killing by the antibiotic was directly proportional to the local growth rate. Growth rates in the biofilm were calculated by using the local concentration of a single growth-limiting substrate with Monod kinetics. The concentration profile of this metabolic substrate was calculated by solving a reaction-diffusion problem. The model predicted the following features: stratified patterns of growth with zones of no growth in the biofilm interior, slow killing of biofilm microorganisms that was further retarded as the initial biofilm thickness increased, nonuniform spatial patterns of killing inside the biofilm, biofilm killing rates that decrease in a nonlinear way as the concentration of the growth-limiting substrate feeding the biofilm is decreased, and heightened tolerance when external mass transfer resistance is manifested. This modeling study also provides motivation for further investigation of a hypothetical cell state in which damaged cells score as nonviable but continue to consume substrate. The existence of such a cell state can further retard biofilm killing, according to the simulations. The results support the important contributions of nutrient limitation and slow growth to the antibiotic tolerance of microorganisms in biofilms. PMID:14693517

  1. Modeling antibiotic tolerance in biofilms by accounting for nutrient limitation.

    PubMed

    Roberts, Mark E; Stewart, Philip S

    2004-01-01

    A mathematical model of biofilm dynamics was used to investigate the protection from antibiotic killing that can be afforded to microorganisms in biofilms based on a mechanism of localized nutrient limitation and slow growth. The model assumed that the rate of killing by the antibiotic was directly proportional to the local growth rate. Growth rates in the biofilm were calculated by using the local concentration of a single growth-limiting substrate with Monod kinetics. The concentration profile of this metabolic substrate was calculated by solving a reaction-diffusion problem. The model predicted the following features: stratified patterns of growth with zones of no growth in the biofilm interior, slow killing of biofilm microorganisms that was further retarded as the initial biofilm thickness increased, nonuniform spatial patterns of killing inside the biofilm, biofilm killing rates that decrease in a nonlinear way as the concentration of the growth-limiting substrate feeding the biofilm is decreased, and heightened tolerance when external mass transfer resistance is manifested. This modeling study also provides motivation for further investigation of a hypothetical cell state in which damaged cells score as nonviable but continue to consume substrate. The existence of such a cell state can further retard biofilm killing, according to the simulations. The results support the important contributions of nutrient limitation and slow growth to the antibiotic tolerance of microorganisms in biofilms.

  2. 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

  3. Comparison of high-calorie, low-nutrient-dense food consumption among obese and non-obese adolescents.

    PubMed

    Bandini, L G; Vu, D; Must, A; Cyr, H; Goldberg, A; Dietz, W H

    1999-09-01

    The purpose of this study was to determine whether obese adolescents eat more high-calorie low-nutrient-dense foods than non-obese adolescents. Using a cross-sectional design, 22 non-obese and 21 obese adolescents kept 14-day food records. Records provided estimates of total daily energy intake and caloric intake from five categories of high-calorie, low-nutrient-dense (HC) foods: candy, chips, soda, baked goods, and ice cream. Body composition was determined by 18O dilution and daily energy expenditure by doubly labeled water. Percentage of energy intake reported (%report) was calculated as the ratio of reported energy intake to measured energy expenditure (x 100%). Both groups underreported energy intake, but the percentage reported was significantly greater in the non-obese group (78.2+/-20.5% non-obese vs. 55.5+/-21.8% obese, p<0.001). Consumption of calories from chips and soda was similar among non-obese and obese adolescents. However, total energy intake from all HC foods was higher in the non-obese group than among the obese (617+/-356 kcal/day vs. 362+/-223 kcal/day; p<0.01) and represented 27.2+/-10.5% and 19.9+/-9.6% of reported energy intake in the non-obese and obese groups, respectively. After adjustment for under-reporting, the percentage of calories provided by each of the HC foods was similar in the obese and non-obese groups except for ice cream, which remained significantly greater in the non-obese group (p<0.05). Our findings suggest that both non-obese and obese adolescents consume a substantial portion of reported calories from HC foods and that obese adolescents do not consume more calories from these foods than non-obese adolescents. These data offer no evidence to support the widespread notion that obese adolescents eat more "junk food" than non-obese adolescents. Health professionals who treat obese adolescents must be aware that the excess calories in their diets may come from a variety of food sources and not solely from high

  4. Development of a model to determine oxygen consumption when crawling.

    PubMed

    Pollard, J P; Heberger, J R; Dempsey, P G

    During a mine disaster or emergency, underground air can quickly become contaminated. In these circumstances, all underground mine workers are taught to don breathable air supply units at the first sign of an emergency. However, no contemporary oxygen consumption data is available for the purposes of designing breathing air supply equipment specifically for mine escape. Further, it would be useful to quantify the oxygen requirements of breathing air supply users for various escape scenarios. To address this need, 14 participants crawled a distance of 305 m each while their breath-by-breath oxygen consumption measurements were taken. Using these data, linear regression models were developed to determine peak and average oxygen consumption rates as well as total oxygen consumption. These models can be used by manufacturers of breathing air supply equipment to aid in the design of devices that would be capable of producing sufficient on-demand oxygen to allow miners to perform self-escape.

  5. Development of a model to determine oxygen consumption when crawling

    PubMed Central

    Pollard, J.P.; Heberger, J.R.; Dempsey, P.G.

    2016-01-01

    During a mine disaster or emergency, underground air can quickly become contaminated. In these circumstances, all underground mine workers are taught to don breathable air supply units at the first sign of an emergency. However, no contemporary oxygen consumption data is available for the purposes of designing breathing air supply equipment specifically for mine escape. Further, it would be useful to quantify the oxygen requirements of breathing air supply users for various escape scenarios. To address this need, 14 participants crawled a distance of 305 m each while their breath-by-breath oxygen consumption measurements were taken. Using these data, linear regression models were developed to determine peak and average oxygen consumption rates as well as total oxygen consumption. These models can be used by manufacturers of breathing air supply equipment to aid in the design of devices that would be capable of producing sufficient on-demand oxygen to allow miners to perform self-escape. PMID:26997858

  6. Tree nut consumption improves nutrient intake and diet quality in US adults: an analysis of National Health and Nutrition Examination Survey (NHANES) 1999-2004.

    PubMed

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

    2010-01-01

    Recent epidemiologic studies assessing tree nut (almonds, Brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pine nuts, pistachios, and walnuts) consumption and the association with nutrient intake and diet quality are lacking. This study determined the association of tree nut consumption and nutrient intake and diet quality using a nationally representative sample of adults. Adults 19+ years (y) (n=13,292) participating in the 1999-2004 National Health and Nutrition Examination Survey were used. Intake was determined from 24-hour diet recalls; tree nut consumers were defined as those consuming > or =(1/4) ounce/day (7.09 g). Means, standard errors, and ANOVA (adjusted for covariates) were determined using appropriate sample weights. Diet quality was measured using the Healthy Eating Index-2005. Among consumers, mean intake of tree nuts/tree nut butters was 1.19 +/- 0.04 oz/d versus 0.01 +/- 0.00 oz/d for non-consumers. In this study, 5.5 +/- 0.3 % of individuals 19-50 y (n=7,049) and 8.4 +/- 0.6 % of individuals 51+ y (n=6,243) consumed tree nuts/tree nut butters. Mean differences (p<0.01) between tree nut consumers and non-consumers of adult shortfall nutrients were: fiber (+5.0 g/d), vitamin E (+3.7 mg AT/d), calcium (+73 mg/d), magnesium (+95 mg/d), and potassium (+260 mg/d). Tree nut consumers had lower sodium intake (-157 mg/d, p<0.01). Diet quality was significantly higher in tree nut consumers (58.0+/-0.4 vs. 48.5+/-0.3, p<0.01). Tree nut consumption was associated with a higher overall diet quality score and improved nutrient intakes. Specific dietary recommendations for nut consumption should be provided for consumers.

  7. Stoichiometry, herbivory and competition for nutrients: simple models based on planktonic ecosystems.

    PubMed

    Grover, James P

    2002-02-21

    Models are examined in which two prey species compete for two nutrient resources, and are preyed upon by a predator that recycles both nutrients. Two factors determine the effective relative supply of the nutrients, hence competitive outcomes: the external nutrient supply ratio, and the relative recycling of the two nutrients within the system. This second factor is governed by predator stoichiometry--its relative requirements for nutrients in its own biomass. A model with nutrient resources that are essential for the competing prey is detailed. Criteria are given to identify the limiting nutrient for a food chain of one competitor with the predator. Increased supply of this limiting nutrient increases predator density and concentration of this nutrient at equilibrium, while decreasing the concentration of a non-limiting nutrient. Changes in supply or recycling of a non-limiting nutrient affect only the concentration of that nutrient. Criteria for the invasion of a second prey competitor are presented. When different nutrients limit growth of the resident prey and the invader, increased supply or recycling of the invader's limiting nutrient assists invasion, while increased supply or recycling of the resident's limiting nutrient hinders invasion. If the same nutrient limits both resident and invader, then changes in supply and recycling have complex effects on invasion, depending on species properties. In a parameterized model of a planktonic ecosystem, green algae and cyanobacteria coexist over a wide range of nitrogen:phosphorus supply ratios, without predators. When the herbivore Daphnia is added, coexistence is eliminated or greatly restricted, and green algae dominate over a wide range of supply conditions, because the effective supply of P is greatly reduced as Daphnia rapidly recycles N.

  8. Food Consumption and Nutrient Intake in Relation to Denture Use in 55- to 84-Year-Old Men and Women -Results of a Population Based Survey.

    PubMed

    Jauhiainen, L; Männistö, S; Ylöstalo, P; Vehkalahti, M; Nordblad, A; Turunen, A W; Suominen, A L N

    2017-01-01

    To study differences in consumption of foods and intake of nutrients attributable to denture status. Data from a cross-sectional, nationally representative Health 2000 Survey, subjects aged 55-84 years (n=2,241). Denture status (edentulous with full dentures, own dentition with removable dentures, own dentition with no removable dentures) was used as an explanatory variable. The consumption of foods and intake of nutrients was used as an outcome variable and was measured using a validated Food Frequency Questionnaire. Denture status associated with food choices. Full denture wearers consumed less vegetables (p = 0.013 among men and p = 0.001 among women) and fruits (p = 0.001 among women), more sugary products (p = 0.012 among men and p = 0.008 among women), and their balance in fatty acids was less favourable than among dentate participants. Among dentate participants, the differences between the two groups were small and statistically significant differences were seen mostly in women. Wearing full dentures appears to be associated with unhealthier food choices, lower consumption of some foodstuffs and lower intake of certain nutrients when compared to the food choices of dentate persons.

  9. Optimizing simulated fertilizer additions using a genetic algorithm with a nutrient uptake model

    Treesearch

    Wendell P. Cropper; N.B. Comerford

    2005-01-01

    Intensive management of pine plantations in the southeastern coastal plain typically involves weed and pest control, and the addition of fertilizer to meet the high nutrient demand of rapidly growing pines. In this study we coupled a mechanistic nutrient uptake model (SSAND, soil supply and nutrient demand) with a genetic algorithm (GA) in order to estimate the minimum...

  10. Research Paper. Nutrient uptake and mineralization during leaf decay in streams-a model simulation.

    Treesearch

    J.R. Webster; J.D. Newbold; S.A. Thomas; H.M. Valett; P.J. Mulholland

    2009-01-01

    We developed a stoichiometrically explicit computer model to examine how heterotrophic uptake of nutrients and microbial mineralization occurring during the decay of leaves in streams may be important in modifying nutrient concentrations. The simulations showed that microbial uptake can substantially decrease stream nutrient concentrations during the initial phases of...

  11. Improvement in Fruit and Vegetable Consumption Associated with More Favorable Energy Density and Nutrient and Food Group Intake, but not Kilocalories.

    PubMed

    Thompson, Debbe; Ferry, Robert J; Cullen, Karen W; Liu, Yan

    2016-09-01

    Children generally do not consume adequate amounts of fruits and vegetables (F/V). Eating more F/V can improve energy density and overall diet quality. Our aim was to investigate whether improvements in F/V consumption were associated with improvements in energy density, total calories, and dietary components related to F/V. We performed secondary analyses of dietary data from a successful four-group randomized controlled trial promoting F/V. Data were collected at baseline, immediately after gameplay, and 3 months post intervention. Preadolescent child-parent dyads (n=400) were recruited. Eligibility criteria were 4th- or 5th-grade child (approximately 9 to 11 years old) with Internet access and a parent willing to participate in the intervention. Complete dietary data were collected on 387 of the 400 child participants. The videogame was available online on a secure, password-protected website. Dietary intake was assessed with three unannounced dietary recalls collected at each data-collection period via telephone by trained staff using Nutrition Data System for Research software. Energy density and F/V, nutrient, and food consumption were calculated. A 4×3 (group by time) repeated measures analysis of covariance with mixed-effect linear models was used. Covariates included child's sex, race/ethnicity, and total energy intake as well as parent's age and household education. Energy was excluded as a covariate in the energy density and energy models. Significant changes occurred in energy density. A significant interaction (group by time) was observed (F6, 515=2.40; P<0.05) in energy density from food only, while a significant time effect was observed for energy density from all foods and beverages (F2, 388=13.75; P<0.0001). Desirable changes were also observed in F/V-related dietary components. Increasing F/V consumption improved energy density and diet quality considerably in preadolescent children. Copyright © 2016 Academy of Nutrition and Dietetics. Published

  12. Short-Term Energy Outlook Model Documentation: Motor Gasoline Consumption Model

    EIA Publications

    2011-01-01

    The motor gasoline consumption module of the Short-Term Energy Outlook (STEO) model is designed to provide forecasts of total U.S. consumption of motor gasolien based on estimates of vehicle miles traveled and average vehicle fuel economy.

  13. Short-Term Energy Outlook Model Documentation: Motor Gasoline Consumption Model

    EIA Publications

    2011-01-01

    The motor gasoline consumption module of the Short-Term Energy Outlook (STEO) model is designed to provide forecasts of total U.S. consumption of motor gasolien based on estimates of vehicle miles traveled and average vehicle fuel economy.

  14. Leaf consumption by insects in three Eucalyptus forest types in Southeastern Australia and their role in short-term nutrient cycling.

    PubMed

    Ohmart, C P; Stewart, L G; Thomas, J R

    1983-09-01

    Leaf consumption by insects in three Eucalyptus forest types (E. delegatensis, E. dives and E. pauciflora) in the Brindabella mountains, A.C.T., was studied over a two year period. Foliage consumption was calculated using two methods: (1) sampling of foliage repeatedly through the season and measurement of leaf area loss due to insects and (2) calculation of the mass of leaves consumed, based on frass-fall measurements. Intensive sampling of tree canopies for defoliating insects was also carried out in all three forest types. Defoliation, as estimated by measurement of leaf area loss, did not exceed 10% in any of the forest types except on current year's foliage for two months of one year in the E. dives and E. pauciflora stands. Insect consumption of foliage in all three forest types, as calculated from frass-fall measurements, varied from 2-3% of annual leaf production. The nitrogen, phosphorus, and potassium passing through insect bodies and frass was less than 4% of the total amount falling in other litter. The small amount of leaf consumption occurring in these stands and the small amount of associated nutrient transfer indicate that insect defoliators at low population levels do not affect forest productivity or have significant effects on short term nutrient cycling.

  15. A realistic dynamic blower energy consumption model for wastewater applications.

    PubMed

    Amerlinck, Y; De Keyser, W; Urchegui, G; Nopens, I

    2016-10-01

    At wastewater treatment plants (WWTPs) aeration is the largest energy consumer. This high energy consumption requires an accurate assessment in view of plant optimization. Despite the ever increasing detail in process models, models for energy production still lack detail to enable a global optimization of WWTPs. A new dynamic model for a more accurate prediction of aeration energy costs in activated sludge systems, equipped with submerged air distributing diffusers (producing coarse or fine bubbles) connected via piping to blowers, has been developed and demonstrated. This paper addresses the model structure, its calibration and application to the WWTP of Mekolalde (Spain). The new model proved to give an accurate prediction of the real energy consumption by the blowers and captures the trends better than the constant average power consumption models currently being used. This enhanced prediction of energy peak demand, which dominates the price setting of energy, illustrates that the dynamic model is preferably used in multi-criteria optimization exercises for minimizing the energy consumption.

  16. Fast-food and full-service restaurant consumption in relation to daily energy and nutrient intakes among US adult cancer survivors, 2003-2012.

    PubMed

    An, Ruopeng; Liu, Junyi

    2013-01-01

    Healthy diet is an essential component in cancer survivorship care planning. Cancer survivors should be particularly prudent regarding their daily food choices, with an aim of ensuring safe consumption, reducing risk of recurrence or other comorbidity, and improving quality of life. We aimed to examine the impacts of fast-food and full-service restaurant consumption on daily energy and nutrient intakes among US adult cancer survivors. Nationally representative data of 1308 adult cancer survivors came from the National Health and Nutrition Examination Survey 2003-2012 waves. First-difference estimator was adopted to address confounding bias from time-invariant unobservables like personal food/beverage preferences by using within-individual variations in diet and restaurant consumption status between two non-consecutive 24-hour dietary recalls. Fast-food and full-service restaurant consumption, respectively, was associated with an increase in daily total energy intake by 125.97 and 152.26 kcal and sodium intake by 312.47 and 373.75 mg. Fast-food consumption was significantly associated with a decrease in daily vitamin A intake by 119.88 µg and vitamin K intake by 30.48 µg, whereas full-service restaurant consumption was associated with an increase in daily fat intake by 8.99 g and omega-6 fatty acid intake by 3.85 g, and a decrease in vitamin D intake by 0.93 µg. Compared with fast-food and full-service restaurant consumption at home, consumption away from home led to further reduced diet quality. Individualized nutrition counseling and food assistance programs should address cancer survivors' overall dining-out behavior rather than fast-food consumption alone. © The Author(s) 2015.

  17. Beyond Rayleigh Distillation: Reconstructing Glacial Nutrient Cycles using a Seasonal Model of the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Kemeny, P. C.; Kast, E.; Fawcett, S. E.; Hain, M.; Sigman, D. M.

    2016-12-01

    The nitrogen (N) isotope ratios of diatom-bound organic matter recovered from Southern Ocean sediment cores have been used to investigate N cycling and the global carbon cycle over glacial-interglacial transitions. Increases in diatom-bound 15N/14N (δ15N) and decreases in export production have qualitatively been interpreted to reflect elevated nitrate (NO3-) consumption and decreased nutrient supply during glacial intervals; however, studies have yet to quantitatively relate paleoceanographic δ15N records to the surface NO3- concentration of ancient oceans. Furthermore, recent studies of the N and oxygen (O) isotope ratios of seawater NO3- reveal that seasonal processes may impact the isotopic signal of exported organic matter. The connection between diatom-bound δ15N and paleoceanographic NO3- availability is explored using a seasonally-resolved 1-dimension model of the Southern Ocean upper water column. The model parameterizes summer and winter physical and biogeochemical processes in the surface mixed layer and the temperature minimum layer. When calibrated to modern conditions, the model reproduces observed deviations from Rayleigh dynamics in the mixed layer, which result from a combination of summertime remineralization, late-summer N recycling, and wintertime nitrification. In glacial simulations, we observe an increase in diatom-bound δ15N that results dominantly from enhanced summertime NO3- consumption, as opposed to resulting from a rise in the δ15N of wintertime NO3-. Yet wintertime mixed layer (and thus initial spring/summer) NO3- concentration is greatly reduced under ice age conditions, such that export production, which has been observed to be lower during glacial intervals, was nevertheless able to consume almost all of the gross nitrate supply. The model suggests that observed differences in δ15N between centric and pennate diatom assemblages can be explained by the near-complete consumption of NO3- in the ice age summer mixed layer.

  18. MODEL SIMULATION STUDIES OF SCALE-DEPENDENT GAIN IN STREAM NUTRIENT ASSIMILATIVE CAPACITY RESULTING FROM IMPROVING NUTRIENT RETENTION METRICS

    EPA Science Inventory

    Considering the difficulty in measuring restoration success for nonpoint source pollutants, nutrient assimilative capacity (NAS) offers an attractive systems-based metric. Here NAS was defined using an impulse-response model of nitrate fate and transport. Eleven parameters were e...

  19. MODEL SIMULATION STUDIES OF SCALE-DEPENDENT GAIN IN STREAM NUTRIENT ASSIMILATIVE CAPACITY RESULTING FROM IMPROVING NUTRIENT RETENTION METRICS

    EPA Science Inventory

    Considering the difficulty in measuring restoration success for nonpoint source pollutants, nutrient assimilative capacity (NAS) offers an attractive systems-based metric. Here NAS was defined using an impulse-response model of nitrate fate and transport. Eleven parameters were e...

  20. An integrated model to measure service management and physical constraints' effect on food consumption in assisted-living facilities.

    PubMed

    Huang, Hui-Chun; Shanklin, Carol W

    2008-05-01

    The United States is experiencing remarkable growth in the elderly population, which provides both opportunities and challenges for assisted-living facilities. The objective of this study was to explore how service management influences residents' actual food consumption in assisted-living facilities. Physical factors influencing residents' service evaluation and food consumption also were investigated. A total of 394 questionnaires were distributed to assisted-living residents in seven randomly selected facilities. The questionnaire was developed based on an in-depth literature review and pilot study. Residents' perceived quality evaluations, satisfaction, and physical constraints were measured. Residents' actual food consumption was measured using a plate waste technique. A total of 118 residents in five facilities completed both questionnaires and food consumption assessments. Descriptive, multivariate analyses and structural equation modeling techniques were employed. Service management, including food and service quality and customer satisfaction, was found to significantly influence residents' food consumption. Physical constraints associated with aging, including a decline in health status, chewing problems, sensory loss, and functional disability, also significantly influenced residents' food consumption. A significant relationship was found between physical constraints and customer satisfaction. Foodservice that provides good food and service quality increases customer satisfaction and affects residents' actual food consumption. Physical constraints also influence residents' food consumption directly, or indirectly through satisfaction. The findings suggest that food and nutrition professionals in assisted-living should consider the physical profiles of their residents to enhance residents' satisfaction and nutrient intake. Recommendations for exploring residents' perspectives are discussed.

  1. Breakfast consumption and nutrient intakes in 4-18-year-olds: UK National Diet and Nutrition Survey Rolling Programme (2008-2012).

    PubMed

    Coulthard, Janine D; Palla, Luigi; Pot, Gerda K

    2017-08-01

    Although breakfast consumption is widely considered to be an important component of a healthy lifestyle, few UK studies have examined differences in nutrient intakes between breakfast consumers and breakfast skippers among children and adolescents. We investigated associations between breakfast skipping in 4-18-year-olds and their nutrient intakes using data from the UK's National Diet and Nutrition Survey Rolling Programme. Dietary data were derived from 4-d estimated food diaries of 802 children aged 4-10 years and 884 children aged 11-18 years (1686 in total). Daily nutrient intakes of children with different breakfast habits were compared by one-way ANCOVA adjusting for relevant covariates (sex, age, ethnicity, equivalised household income and BMI). Within-person analysis was carried out on children with an irregular breakfast habit (n 879) comparing nutrient intakes on breakfast days with those on non-breakfast days using repeated measures ANCOVA. We observed that the overall nutritional profile of the children in terms of fibre and micronutrient intake was superior in frequent breakfast consumers (micronutrients: folate, Ca, Fe and I (P<0·01)) and, for the 4-10 years age group, on breakfast days (micronutrients: folate, vitamin C, Ca and I (P<0·01)). Also, significantly higher proportions of breakfast-consuming children met their reference nutrient intakes of folate, vitamin C, Ca, Fe and I compared with breakfast skippers (χ 2 analysis, P<0·001). Our study adds to the body of data linking breakfast consumption with higher quality dietary intake in school-age children, supporting the promotion of breakfast as an important element of a healthy dietary pattern in children.

  2. Pan-European modelling of riverine nutrient concentrations - spatial patterns, source detection, trend analyses, scenario modelling

    NASA Astrophysics Data System (ADS)

    Bartosova, Alena; Arheimer, Berit; Capell, Rene; Donnelly, Chantal; Strömqvist, Johan

    2016-04-01

    Nutrient transport models are important tools for large scale assessments of macro-nutrient fluxes (nitrogen, phosphorus) and thus can serve as support tool for environmental assessment and management. Results from model applications over large areas, i.e. from major river basin to continental scales can fill a gap where monitoring data is not available. Here, we present results from the pan-European rainfall-runoff and nutrient transfer model E-HYPE, which is based on open data sources. We investigate the ability of the E-HYPE model to replicate the spatial and temporal variations found in observed time-series of riverine N and P concentrations, and illustrate the model usefulness for nutrient source detection, trend analyses, and scenario modelling. The results show spatial patterns in N concentration in rivers across Europe which can be used to further our understanding of nutrient issues across the European continent. E-HYPE results show hot spots with highest concentrations of total nitrogen in Western Europe along the North Sea coast. Source apportionment was performed to rank sources of nutrient inflow from land to sea along the European coast. An integrated dynamic model as E-HYPE also allows us to investigate impacts of climate change and measure programs, which was illustrated in a couple of scenarios for the Baltic Sea. Comparing model results with observations shows large uncertainty in many of the data sets and the assumptions used in the model set-up, e.g. point source release estimates. However, evaluation of model performance at a number of measurement sites in Europe shows that mean N concentration levels are generally well simulated. P levels are less well predicted which is expected as the variability of P concentrations in both time and space is higher. Comparing model performance with model set-ups using local data for the Weaver River (UK) did not result in systematically better model performance which highlights the complexity of model

  3. Food consumption patterns, diversity of food nutrients and mean nutrient intake in relation to HIV/AIDS status in Kisumu district Kenya.

    PubMed

    Onyango, Agatha Christine; Walingo, Mary Khakoni; Othuon, Lucas

    2009-09-01

    As the causes and consequences of the AIDS epidemic become clearer, so does the fundamental importance of food and nutritional security for HIV-affected individuals. Even as food insecurity remains a major problem in poor households, its effects are worsened in disease states like HIV infection. Food deficiency and nutritional inadequacy compromise an individual's physical status and work capacity, and may also diminish their resource base and household provisioning. The prevalence of HIV and AIDS in Kenya threatens food production systems, which intensifies poverty, increases the nutritional implications for HIV-infected individuals, accelerates the rate of orphanhood beyond what existing social networks can cope with, and basically affects all indicators of socio-economic development in the country. This cross-sectional study sought to assess food and nutrient intake in HIV-affected versus non-HIV-affected households. Purposive sampling was used to select 160 households (77 HIV-affected households and 83 non-HIV-affected households) in Kisumu district, a lowland area along Lake Victoria. A consolidated questionnaire that included a food-frequency checklist and personal 24-hour dietary recall was used to gather information from 40 households. The data were analysed quantitatively; descriptive statistics were mainly measures of central tendency, and inferential statistics involved chi-square tests and independent t-test samples. A table depicting food composition was used to compute the nutrient intake of each household. The findings reveal a significant relationship between a household's HIV/AIDS status and nutrient intake.

  4. Prey-predator model with a nonlocal consumption of prey

    NASA Astrophysics Data System (ADS)

    Banerjee, M.; Volpert, V.

    2016-08-01

    The prey-predator model with nonlocal consumption of prey introduced in this work extends previous studies of local reaction-diffusion models. Linear stability analysis of the homogeneous in space stationary solution and numerical simulations of nonhomogeneous solutions allow us to analyze bifurcations and dynamics of stationary solutions and of travelling waves. These solutions present some new properties in comparison with the local models. They correspond to different feeding strategies of predators observed in ecology.

  5. Prey-predator model with a nonlocal consumption of prey.

    PubMed

    Banerjee, M; Volpert, V

    2016-08-01

    The prey-predator model with nonlocal consumption of prey introduced in this work extends previous studies of local reaction-diffusion models. Linear stability analysis of the homogeneous in space stationary solution and numerical simulations of nonhomogeneous solutions allow us to analyze bifurcations and dynamics of stationary solutions and of travelling waves. These solutions present some new properties in comparison with the local models. They correspond to different feeding strategies of predators observed in ecology.

  6. Modelling diffuse nutrient flow in eutrophication control scenarios.

    PubMed

    Arheimer, B; Andersson, L; Larsson, M; Lindström, G; Olsson, J; Pers, B C

    2004-01-01

    The Swedish Water Management Research Programme (VASTRA) focuses on the development and demonstration of tools for more efficient eutrophication control when implementing the EU water framework directive in Sweden. During the first half of the programme, models for nitrogen flow were developed, and at present, similar models for phosphorus are under construction (e.g. HBV-P). The programme is interdisciplinary, and scientists are collaborating in actor-games and focus group evaluations including scenario analysis. The scenarios modelled in VASTRA phase I, show that (i) changed agricultural practices can be the most effective and least expensive way to reduce nitrogen transport from land to the sea; (ii) constructed agricultural wetlands may only have small impact on riverine nitrogen transport in some regions, due to natural hydrometeorological dynamics; (iii) removing planktivorous fish may be an efficient way of reducing the algal concentrations in lakes without the undesired side-effect of increased nutrient load to the down-stream river system. In VASTRA phase II, one of the highlights will be interdisciplinary scenario-modelling of different measure strategies in a pilot catchment of southern Sweden (Rönne å).

  7. The MARINA model (Model to Assess River Inputs of Nutrients to seAs): Model description and results for China.

    PubMed

    Strokal, Maryna; Kroeze, Carolien; Wang, Mengru; Bai, Zhaohai; Ma, Lin

    2016-08-15

    Chinese agriculture has been developing fast towards industrial food production systems that discharge nutrient-rich wastewater into rivers. As a result, nutrient export by rivers has been increasing, resulting in coastal water pollution. We developed a Model to Assess River Inputs of Nutrients to seAs (MARINA) for China. The MARINA Nutrient Model quantifies river export of nutrients by source at the sub-basin scale as a function of human activities on land. MARINA is a downscaled version for China of the Global NEWS-2 (Nutrient Export from WaterSheds) model with an improved approach for nutrient losses from animal production and population. We use the model to quantify dissolved inorganic and organic nitrogen (N) and phosphorus (P) export by six large rivers draining into the Bohai Gulf (Yellow, Hai, Liao), Yellow Sea (Yangtze, Huai) and South China Sea (Pearl) in 1970, 2000 and 2050. We addressed uncertainties in the MARINA Nutrient model. Between 1970 and 2000 river export of dissolved N and P increased by a factor of 2-8 depending on sea and nutrient form. Thus, the risk for coastal eutrophication increased. Direct losses of manure to rivers contribute to 60-78% of nutrient inputs to the Bohai Gulf and 20-74% of nutrient inputs to the other seas in 2000. Sewage is an important source of dissolved inorganic P, and synthetic fertilizers of dissolved inorganic N. Over half of the nutrients exported by the Yangtze and Pearl rivers originated from human activities in downstream and middlestream sub-basins. The Yellow River exported up to 70% of dissolved inorganic N and P from downstream sub-basins and of dissolved organic N and P from middlestream sub-basins. Rivers draining into the Bohai Gulf are drier, and thus transport fewer nutrients. For the future we calculate further increases in river export of nutrients. The MARINA Nutrient model quantifies the main sources of coastal water pollution for sub-basins. This information can contribute to formulation of

  8. Nutrient uptake and mineralization during leaf decay in streams - a model simulation

    SciTech Connect

    Webster, Jackson; Newbold, J. Denis; Thomas, Steve; Valett, H. Maurice; Mulholland, Patrick J

    2009-01-01

    We developed a stoichiometrically explicit computer model to examine how heterotrophic uptake of nutrients and microbial mineralization occurring during the decay of leaves in streams may be important in modifying nutrient concentrations. The simulations showed that microbial uptake can substantially decrease stream nutrient concentrations during the initial phases of decomposition, while mineralization may produce increases in concentrations during later stages of decomposition. The simulations also showed that initial nutrient content of the leaves can affect the stream nutrient concentration dynamics and determine whether nitrogen or phosphorus is the limiting nutrient. Finally, the simulations suggest a net retention (uptake > mineralization) of nutrients in headwater streams, which is balanced by export of particulate organic nutrients to downstream reaches. Published studies support the conclusion that uptake can substantially change stream nutrient concentrations. On the other hand, there is little published evidence that mineralization also affects nutrient concentrations. Also, there is little information on direct microbial utilization of nutrients contained in the decaying leaves themselves. Our results suggest several directions for research that will improve our understanding of the complex relationship between leaf decay and nutrient dynamics in streams.

  9. Oxygen consumption dynamics in steady-state tumour models.

    PubMed

    Grimes, David Robert; Fletcher, Alexander G; Partridge, Mike

    2014-09-01

    Oxygen levels in cancerous tissue can have a significant effect on treatment response: hypoxic tissue is both more radioresistant and more chemoresistant than well-oxygenated tissue. While recent advances in medical imaging have facilitated real-time observation of macroscopic oxygenation, the underlying physics limits the resolution to the millimetre domain, whereas oxygen tension varies over a micrometre scale. If the distribution of oxygen in the tumour micro-environment can be accurately estimated, then the effect of potential dose escalation to these hypoxic regions could be better modelled, allowing more realistic simulation of biologically adaptive treatments. Reaction-diffusion models are commonly used for modelling oxygen dynamics, with a variety of functional forms assumed for the dependence of oxygen consumption rate (OCR) on cellular status and local oxygen availability. In this work, we examine reaction-diffusion models of oxygen consumption in spherically and cylindrically symmetric geometries. We consider two different descriptions of oxygen consumption: one in which the rate of consumption is constant and one in which it varies with oxygen tension in a hyperbolic manner. In each case, we derive analytic approximations to the steady-state oxygen distribution, which are shown to closely match the numerical solutions of the equations and accurately predict the extent to which oxygen can diffuse. The derived expressions relate the limit to which oxygen can diffuse into a tissue to the OCR of that tissue. We also demonstrate that differences between these functional forms are likely to be negligible within the range of literature estimates of the hyperbolic oxygen constant, suggesting that the constant consumption rate approximation suffices for modelling oxygen dynamics for most values of OCR. These approximations also allow the rapid identification of situations where hyperbolic consumption forms can result in significant differences from constant

  10. THE COMPARISON OF TWO WATERSHEDS USING A WATERSHED NUTRIENT LOADING MODEL

    EPA Science Inventory

    Monitoring data, collected from the Yaquina River, Oregon, from 1999 through 2002 were used as the basis for developing the nutrient flux model as part of a larger agency program for quantifying nutrient processes. The PNWL nitrate loading model indicates that the nitrate load is...

  11. THE COMPARISON OF TWO WATERSHEDS USING A WATERSHED NUTRIENT LOADING MODEL

    EPA Science Inventory

    Monitoring data, collected from the Yaquina River, Oregon, from 1999 through 2002 were used as the basis for developing the nutrient flux model as part of a larger agency program for quantifying nutrient processes. The PNWL nitrate loading model indicates that the nitrate load is...

  12. Modelling C allocation in response to nutrient availability

    NASA Astrophysics Data System (ADS)

    Stocker, Benjamin; Prentice, Colin

    2015-04-01

    Carbon (C) allocation in ecosystems is a key variable of the global terrestrial C cycle. While photosynthesis governs the amount of C that enters ecosystems, its subsequent allocation to compartments with different life times determines its over-all residence time and variations in allocation patterns drive changes in ecosystem C balance and its response to environmental change. A better understanding of the controls on allocation is thus key to improving global vegetation models that commonly rely on using fixed partitioning factors. Observational data suggests variations of ecosystem structure and functioning along large-scale gradients of resource availability. Below-ground C allocation, inferred as gross primary production minus above-ground biomass production increases along gradients of decreasing nutrient availability. This is not only due to more root growth, but also due to enhanced production of exudates and stimulation of root symbionts and has been interpreted to reflect optimal plant allocation decisions under a varying soil fertility status. Here, we propose a model that accounts for trade-offs between (i) growth in above-ground and (ii) below-ground plant compartments, (iii) exudation to the rhizosphere and root symbionts and (iv) temporary storage in non-structural pools. By postulating the maximization of long-term growth under a given (seasonal regime) of soil nitrogen (N) availability, we attempt to reproduce observed large-scale gradients. The model is formulated based on a C cost for different N uptake decisions, where the cost is a function of N availability, root mass, and soil temperature (for biological N fixation). On a daily time scale, ecosystem N uptake may be realized by C exudation to the rhizosphere and/or symbiotic fixation of atmospheric N2. On an annual time scale, allocation to roots versus leaves is adjusted to soil inorganic N availability and modeled to yield maximum total growth. Exudation versus temporary storage of C is

  13. Sensitivity of hypoxia predictions for the northern Gulf of Mexico to sediment oxygen consumption and model nesting

    NASA Astrophysics Data System (ADS)

    Fennel, Katja; Hu, Jiatang; Laurent, Arnaud; Marta-Almeida, Martinho; Hetland, Robert

    2013-02-01

    Every summer, a large area (15,000 km2 on average) over the Texas-Louisiana shelf in the northern Gulf of Mexico turns hypoxic due to decay of organic matter that is primarily derived from nutrient inputs from the Mississippi/Atchafalaya River System. Interannual variability in the size of the hypoxic zone is large. The 2008 Action Plan put forth by the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force, an alliance of multiple state and federal agencies and tribes, calls for a reduction of the size of the hypoxic zone through nutrient management in the watershed. Comprehensive models help build mechanistic understanding of the processes underlying hypoxia formation and variability and are thus indispensable tools for devising efficient nutrient reduction strategies and for building reasonable expectations as to what responses can be expected for a given nutrient reduction. Here we present such a model, evaluate its hypoxia simulations against monitoring observations, and assess the sensitivity of the hypoxia simulations to model resolution, variations in sediment oxygen consumption, and choice of physical horizontal boundary conditions. We find that hypoxia simulations on the shelf are very sensitive to the parameterization of sediment oxygen consumption, a result of the fact that hypoxic conditions are restricted to a relatively thin layer above the bottom over most of the shelf. We show that the strength of vertical stratification is an important predictor of dissolved oxygen concentration in bottom waters and that modification of physical horizontal boundary conditions can have a large effect on hypoxia simulations because it can affect stratification strength.

  14. Contribution of beef consumption to nutrient intake, diet quality, and food patterns in the diets of the US population

    USDA-ARS?s Scientific Manuscript database

    This study examined the association between the nutrient contribution of beef, in its lowest and highest fat forms, and diet quality and food patterns in individuals 4+ years of age. Beef consumers were categorized into three groups (lowest lean/highest fat [LLHF]; middle lean/middle fat content; an...

  15. Consumption of ready-to-eat cereals (RTEC) among Malaysian children and association with socio-demographics and nutrient intakes – findings from the MyBreakfast study

    PubMed Central

    Mohd Nasir, Mohd Taib; Nurliyana, Abdul Razak; Norimah, A. Karim; Jan Mohamed, Hamid Jan B.; Tan, Sue Yee; Appukutty, Mahenderan; Hopkins, Sinead; Thielecke, Frank; Ong, Moi Kim; Ning, Celia; Tee, E. Siong

    2017-01-01

    ABSTRACT Background: The association between different types of breakfast meals and nutrient intakes has been studied to a lesser extent. Objective: This study compared nutrient intakes at breakfast and throughout the day between Malaysian children who consumed ready-to-eat cereals (RTEC) and those who did not. Methods: Anthropometric and dietary data for 1955 children aged 6–12 years from the MyBreakfast study were used in the analysis. Results: Overall, 18% of the children consumed RTEC at breakfast on at least one of the recall days. RTEC consumption was associated with younger age, urban areas, higher income and education level of parents. Among consumers, RTEC contributed 10% and 15% to daily intakes of calcium and iron respectively and ≥20% to daily intakes of vitamin C, thiamin, riboflavin and niacin. RTEC consumers had significantly higher mean intakes of vitamin C, thiamin, riboflavin, niacin, calcium, iron and sugar but lower intakes of fat and sodium than non-RTEC consumers at breakfast and for the total day. Conclusion: Consumption of fortified RTEC at breakfast was associated with lower fat and sodium intakes and higher intakes of several micronutrients both at breakfast and for the total day. However, total sugar intakes appeared to be higher. PMID:28469545

  16. Consumption of ready-to-eat cereals (RTEC) among Malaysian children and association with socio-demographics and nutrient intakes - findings from the MyBreakfast study.

    PubMed

    Mohd Nasir, Mohd Taib; Nurliyana, Abdul Razak; Norimah, A Karim; Jan Mohamed, Hamid Jan B; Tan, Sue Yee; Appukutty, Mahenderan; Hopkins, Sinead; Thielecke, Frank; Ong, Moi Kim; Ning, Celia; Tee, E Siong

    2017-01-01

    Background: The association between different types of breakfast meals and nutrient intakes has been studied to a lesser extent. Objective: This study compared nutrient intakes at breakfast and throughout the day between Malaysian children who consumed ready-to-eat cereals (RTEC) and those who did not. Methods: Anthropometric and dietary data for 1955 children aged 6-12 years from the MyBreakfast study were used in the analysis. Results: Overall, 18% of the children consumed RTEC at breakfast on at least one of the recall days. RTEC consumption was associated with younger age, urban areas, higher income and education level of parents. Among consumers, RTEC contributed 10% and 15% to daily intakes of calcium and iron respectively and ≥20% to daily intakes of vitamin C, thiamin, riboflavin and niacin. RTEC consumers had significantly higher mean intakes of vitamin C, thiamin, riboflavin, niacin, calcium, iron and sugar but lower intakes of fat and sodium than non-RTEC consumers at breakfast and for the total day. Conclusion: Consumption of fortified RTEC at breakfast was associated with lower fat and sodium intakes and higher intakes of several micronutrients both at breakfast and for the total day. However, total sugar intakes appeared to be higher.

  17. Low Calorie Beverage Consumption Is Associated with Energy and Nutrient Intakes and Diet Quality in British Adults.

    PubMed

    Gibson, Sigrid A; Horgan, Graham W; Francis, Lucy E; Gibson, Amelia A; Stephen, Alison M

    2016-01-02

    It is unclear whether consumption of low-calorie beverages (LCB) leads to compensatory consumption of sweet foods, thus reducing benefits for weight control or diet quality. This analysis investigated associations between beverage consumption and energy intake and diet quality of adults in the UK National Diet and Nutrition Survey (NDNS) (2008-2011; n = 1590), classified into: (a) non-consumers of soft drinks (NC); (b) LCB consumers; (c) sugar-sweetened beverage (SSB) consumers; or (d) consumers of both beverages (BB), based on 4-day dietary records. Within-person data on beverage consumption on different days assessed the impact on energy intake. LCB consumers and NC consumed less energy and non-milk extrinsic sugars than other groups. Micronutrient intakes and food choices suggested higher dietary quality in NC/LCB consumers compared with SSB/BB consumers. Within individuals on different days, consumption of SSB, milk, juice, and alcohol were all associated with increased energy intake, while LCB and tea, coffee or water were associated with no change; or reduced energy intake when substituted for caloric beverages. Results indicate that NC and LCB consumers tend to have higher quality diets compared with SSB or BB consumers and do not compensate for sugar or energy deficits by consuming more sugary foods.

  18. Low Calorie Beverage Consumption Is Associated with Energy and Nutrient Intakes and Diet Quality in British Adults

    PubMed Central

    Gibson, Sigrid A.; Horgan, Graham W.; Francis, Lucy E.; Gibson, Amelia A.; Stephen, Alison M.

    2016-01-01

    It is unclear whether consumption of low-calorie beverages (LCB) leads to compensatory consumption of sweet foods, thus reducing benefits for weight control or diet quality. This analysis investigated associations between beverage consumption and energy intake and diet quality of adults in the UK National Diet and Nutrition Survey (NDNS) (2008–2011; n = 1590), classified into: (a) non-consumers of soft drinks (NC); (b) LCB consumers; (c) sugar-sweetened beverage (SSB) consumers; or (d) consumers of both beverages (BB), based on 4-day dietary records. Within-person data on beverage consumption on different days assessed the impact on energy intake. LCB consumers and NC consumed less energy and non-milk extrinsic sugars than other groups. Micronutrient intakes and food choices suggested higher dietary quality in NC/LCB consumers compared with SSB/BB consumers. Within individuals on different days, consumption of SSB, milk, juice, and alcohol were all associated with increased energy intake, while LCB and tea, coffee or water were associated with no change; or reduced energy intake when substituted for caloric beverages. Results indicate that NC and LCB consumers tend to have higher quality diets compared with SSB or BB consumers and do not compensate for sugar or energy deficits by consuming more sugary foods. PMID:26729159

  19. Employment, Production and Consumption model: Patterns of phase transitions

    NASA Astrophysics Data System (ADS)

    Lavička, H.; Lin, L.; Novotný, J.

    2010-04-01

    We have simulated the model of Employment, Production and Consumption (EPC) using Monte Carlo. The EPC model is an agent based model that mimics very basic rules of industrial economy. From the perspective of physics, the nature of the interactions in the EPC model represents multi-agent interactions where the relations among agents follow the key laws for circulation of capital and money. Monte Carlo simulations of the stochastic model reveal phase transition in the model economy. The two phases are the phase with full unemployment and the phase with nearly full employment. The economy switches between these two states suddenly as a reaction to a slight variation in the exogenous parameter, thus the system exhibits strong non-linear behavior as a response to the change of the exogenous parameters.

  20. Nutrient intakes of children aged 1-2 years as a function of milk consumption, cows' milk or growing-up milk.

    PubMed

    Ghisolfi, Jacques; Fantino, Marc; Turck, Dominique; de Courcy, Geneviève Potier; Vidailhet, Michel

    2013-03-01

    To evaluate the nutritional adequacy of diets in early childhood as a function of milk intake, cows' milk (CM) or growing-up milk (GUM). From a cross-sectional food consumption survey, two groups of children aged 1-2 years were defined: group CM fed exclusively on CM ≥ 250 ml/d and group GUM fed on GUM ≥ 250 ml/d. Proportions of children at risk of nutrient excess or insufficiency were estimated relative to the French recommended daily allowances, estimated average requirements or adequate intakes. Parents participating in the survey were recruited from all regions of France by a polling organization. Distribution was adjusted to that of the French population. Sixty-three (group CM) and fifty-five (group GUM) children. Total energy and macronutrient intakes were similar in the two groups except protein intake of group CM, which was much higher than the Recommended Daily Allowance and significantly higher than in group GUM. A high percentage of children of Group CM had intake of linoleic acid (51%) and α-linolenic acid (84%) below the lower limit of the adequate intake, and intake of Fe (59%) vitamin C (49%) and alimentary vitamin D (100%) less than the Estimated Average Requirement. Significant differences were observed in the proportions of children with a risk of dietary inadequacy between the two groups for all the mentioned nutrients (P < 0.001). In group GUM, this imbalance was only observed for vitamin D. Intake of foods other than milk and dairy products could not account for these discrepancies. Consumption of CM (≥250 ml/d) entails the risk of insufficiency in α-linolenic acid, Fe, vitamin C and vitamin D. Use of GUM (≥250 ml/d) significantly reduces the risk of insufficiencies in the mentioned nutrients.

  1. Energy compensation and nutrient displacement following regular consumption of hazelnuts and other energy-dense snack foods in non-obese individuals.

    PubMed

    Pearson, Katherine R; Tey, Siew Ling; Gray, Andrew R; Chisholm, Alexandra; Brown, Rachel C

    2017-04-01

    Regular nut consumption reduces cardiovascular disease risk, partly from improvements to dietary quality. Examining how individuals make dietary changes when consuming nuts may reveal key behavioural eating patterns beneficial for the development of dietary interventions. We examined the effects of nuts in comparison with other energy-dense snacks on energy compensation, nutrient displacement, and food group patterns. This was a 12-week randomised, controlled, parallel study with four arms: ~1100 kJ/day for each of hazelnuts (42 g), chocolate (50 g), potato crisps (50 g), or no added snack food. Diet records, body composition, and physical activity were measured at baseline and week 12, in 102 non-obese participants. Significant improvements in diet quality were observed in the hazelnut group, particularly when consumed as snacks. Intakes of monounsaturated fat (MUFA) and vitamin E were significantly higher (all P < 0.05), whereas saturated fat and carbohydrate were significantly lower (both P ≤ 0.022) in the hazelnut group compared to the other groups. Partial energy compensation did not differ significantly between groups, but nutrient displacement values for MUFA and fibre differed significantly. Within the hazelnut group, there was nearly complete displacement for fibre, partial displacement for energy, protein, total fat, MUFA, PUFA, potassium, folate, and vitamin E, and overcompensation for carbohydrate and sugar. Our results demonstrate that energy compensation occurs for all three intervention snacks in this non-obese population. Regular nut consumption significantly improves nutrient profiles compared to other snacks with changes occurring at the snack level.

  2. Modeling nutrient flows in the food chain of China.

    PubMed

    Ma, L; Ma, W Q; Velthof, G L; Wang, F H; Qin, W; Zhang, F S; Oenema, O

    2010-01-01

    Increasing nitrogen (N) and phosphorus (P) inputs have greatly contributed to the increasing food production in China during the last decades, but have also increased N and P losses to the environment. The pathways and magnitude of these losses are not well quantified. Here, we report on N and P use efficiencies and losses at a national scale in 2005, using the model NUFER (NUtrient flows in Food chains, Environment and Resources use). Total amount of "new" N imported to the food chain was 48.8 Tg in 2005. Only 4.4.Tg reached households as food. Average N use efficiencies in crop production, animal production, and the whole food chain were 26, 11, and 9%, respectively. Most of the imported N was lost to the environment, that is, 23 Tg N to atmosphere, as ammonia (57%), nitrous oxide (2%), dinitrogen (33%), and nitrogen oxides (8%), and 20 Tg to waters. The total P input into the food chain was 7.8 Tg. The average P use efficiencies in crop production, animal production, and the whole food chain were 36, 5, and 7%, respectively. This is the first comprehensive overview of N and P balances, losses, and use efficiencies of the food chain in China. It shows that the N and P costs of food are high (for N 11 kg kg(-1), for P 13 kg kg(-1)). Key measures for lowering the N and P costs of food production are (i) increasing crop and animal production, (ii) balanced fertilization, and (iii) improved manure management.

  3. Modeling of Methods to Control Heat-Consumption Efficiency

    NASA Astrophysics Data System (ADS)

    Tsynaeva, E. A.; Tsynaeva, A. A.

    2016-11-01

    In this work, consideration has been given to thermophysical processes in automated heat consumption control systems (AHCCSs) of buildings, flow diagrams of these systems, and mathematical models describing the thermophysical processes during the systems' operation; an analysis of adequacy of the mathematical models has been presented. A comparison has been made of the operating efficiency of the systems and the methods to control the efficiency. It has been determined that the operating efficiency of an AHCCS depends on its diagram and the temperature chart of central quality control (CQC) and also on the temperature of a low-grade heat source for the system with a heat pump.

  4. Scientific and technical advisory committee review of the nutrient inputs to the watershed model

    USDA-ARS?s Scientific Manuscript database

    The following is a report by a STAC Review Team concerning the methods and documentation used by the Chesapeake Bay Partnership for evaluation of nutrient inputs to Phase 6 of the Chesapeake Bay Watershed Model. The “STAC Review of the Nutrient Inputs to the Watershed Model” (previously referred to...

  5. Nutrient supply and mercury dynamics in marine ecosystems: a conceptual model.

    PubMed

    Driscoll, Charles T; Chen, Celia Y; Hammerschmidt, Chad R; Mason, Robert P; Gilmour, Cynthia C; Sunderland, Elsie M; Greenfield, Ben K; Buckman, Kate L; Lamborg, Carl H

    2012-11-01

    There is increasing interest and concern over the impacts of mercury (Hg) inputs to marine ecosystems. One of the challenges in assessing these effects is that the cycling and trophic transfer of Hg are strongly linked to other contaminants and disturbances. In addition to Hg, a major problem facing coastal waters is the impacts of elevated nutrient, particularly nitrogen (N), inputs. Increases in nutrient loading alter coastal ecosystems in ways that should change the transport, transformations and fate of Hg, including increases in fixation of organic carbon and deposition to sediments, decreases in the redox status of sediments and changes in fish habitat. In this paper we present a conceptual model which suggests that increases in loading of reactive N to marine ecosystems might alter Hg dynamics, decreasing bioavailabilty and trophic transfer. This conceptual model is most applicable to coastal waters, but may also be relevant to the pelagic ocean. We present information from case studies that both support and challenge this conceptual model, including marine observations across a nutrient gradient; results of a nutrient-trophic transfer Hg model for pelagic and coastal ecosystems; observations of Hg species, and nutrients from coastal sediments in the northeastern U.S.; and an analysis of fish Hg concentrations in estuaries under different nutrient loadings. These case studies suggest that changes in nutrient loading can impact Hg dynamics in coastal and open ocean ecosystems. Unfortunately none of the case studies is comprehensive; each only addresses a portion of the conceptual model and has limitations. Nevertheless, our conceptual model has important management implications. Many estuaries near developed areas are impaired due to elevated nutrient inputs. Widespread efforts are underway to control N loading and restore coastal ecosystem function. An unintended consequence of nutrient control measures could be to exacerbate problems associated with Hg

  6. Nutrient supply and mercury dynamics in marine ecosystems: A conceptual model

    PubMed Central

    Chen, Celia Y.; Hammerschmidt, Chad R.; Mason, Robert P.; Gilmour, Cynthia C.; Sunderland, Elsie M.; Greenfield, Ben K.; Buckman, Kate L.; Lamborg, Carl H.

    2013-01-01

    There is increasing interest and concern over the impacts of mercury (Hg) inputs to marine ecosystems. One of the challenges in assessing these effects is that the cycling and trophic transfer of Hg are strongly linked to other contaminants and disturbances. In addition to Hg, a major problem facing coastal waters is the impacts of elevated nutrient, particularly nitrogen (N), inputs. Increases in nutrient loading alter coastal ecosystems in ways that should change the transport, transformations and fate of Hg, including increases in fixation of organic carbon and deposition to sediments, decreases in the redox status of sediments and changes in fish habitat. In this paper we present a conceptual model which suggests that increases in loading of reactive N to marine ecosystems might alter Hg dynamics, decreasing bioavailabilty and trophic transfer. This conceptual model is most applicable to coastal waters, but may also be relevant to the pelagic ocean. We present information from case studies that both support and challenge this conceptual model, including marine observations across a nutrient gradient; results of a nutrient-trophic transfer Hg model for pelagic and coastal ecosystems; observations of Hg species, and nutrients from coastal sediments in the northeastern U.S.; and an analysis of fish Hg concentrations in estuaries under different nutrient loadings. These case studies suggest that changes in nutrient loading can impact Hg dynamics in coastal and open ocean ecosystems. Unfortunately none of the case studies is comprehensive; each only addresses a portion of the conceptual model and has limitations. Nevertheless, our conceptual model has important management implications. Many estuaries near developed areas are impaired due to elevated nutrient inputs. Widespread efforts are underway to control N loading and restore coastal ecosystem function. An unintended consequence of nutrient control measures could be to exacerbate problems associated with Hg

  7. A Multi-Agency Nutrient Dataset Used to Estimate Loads, Improve Monitoring Design, and Calibrate Regional Nutrient SPARROW Models

    USGS Publications Warehouse

    Saad, D.A.; Schwarz, G.E.; Robertson, D.M.; Booth, N.L.

    2011-01-01

    Stream-loading information was compiled from federal, state, and local agencies, and selected universities as part of an effort to develop regional SPAtially Referenced Regressions On Watershed attributes (SPARROW) models to help describe the distribution, sources, and transport of nutrients in streams throughout much of the United States. After screening, 2,739 sites, sampled by 73 agencies, were identified as having suitable data for calculating long-term mean annual nutrient loads required for SPARROW model calibration. These sites had a wide range in nutrient concentrations, loads, and yields, and environmental characteristics in their basins. An analysis of the accuracy in load estimates relative to site attributes indicated that accuracy in loads improve with increases in the number of observations, the proportion of uncensored data, and the variability in flow on observation days, whereas accuracy declines with increases in the root mean square error of the water-quality model, the flow-bias ratio, the number of days between samples, the variability in daily streamflow for the prediction period, and if the load estimate has been detrended. Based on compiled data, all areas of the country had recent declines in the number of sites with sufficient water-quality data to compute accurate annual loads and support regional modeling analyses. These declines were caused by decreases in the number of sites being sampled and data not being entered in readily accessible databases. ?? 2011 American Water Resources Association. This article is a U.S. Government work and is in the public domain in the USA.

  8. [Milk consumption and effects on dietary nutrients and growth status among Chinese children in nine provinces (autonomous region) from 1991 to 2006].

    PubMed

    DU, Wen-Wen; Zhang, Bing; Wang, Hui-Jun; Wang, Zhi-Hong; Su, Chang; Zhai, Feng-Ying

    2011-04-01

    To investigate milk consumption and effects on dietary nutrients and growth status among 7 - 17 years-old Chinese children in 9 provinces (autonomous region) from 1991 to 2006. Data was collected in 1991, 1993, 1997, 2000, 2004 and 2006 China Health and Nutrition Survey, and 11 691 subjects aged 7 to 17 years old were included. The subjects were divided into the following groups according to milk consumption per day, 0 (no milk drinking), 1 - 99, 100 - 199, 200 - 299 and ≥ 300 g/d. Variables from different years were compared, such as milk categories, energy, protein, calcium intake, body mass index (BMI), as well as that dietary nutrients, height and weight among different milk consumption groups. From 1991 to 2006, milk drinking rate and milk consumption among Chinese children had great improvement: milk drinking rate reached to 14.1% (161/1145) in 2006, while that was 3.0% (73/2441) in 1991; milk consumption reached to (26.7 ± 85.0) g/d in 2006, which was 6.8 times of that in 1991 (3.9 ± 31.9) g/d (χ(2) = 474.5, P < 0.01). BMI increased from (17.3 ± 2.9) kg/m(2) in 1991 to (18.5 ± 6.0) kg/m(2) in 2006 (χ(2) = 123.5, P < 0.01). Meanwhile, energy intake decreased from (8653.3 ± 2789.2) kJ/d in 1991 to (8058.3 ± 2866.6) kJ/d in 2006 (χ(2) = 72.6, P < 0.01); protein intake decreased from (63.0 ± 22.8) g/d in 1991 to (57.3 ± 23.1) g/d in 2006 (χ(2) = 71.9, P < 0.01). Average height of 0 (no milk drinking), 1 - 99, 100 - 199, 200 - 299 and ≥ 300 g/d groups were (142.9 ± 16.9), (146.9 ± 18.8), (147.6 ± 16.2), (148.8 ± 16.0), (149.9 ± 15.3) cm, respectively (χ(2) = 29.4, P < 0.01); average weight were (37.1 ± 13.2), (40.3 ± 13.9), (41.3 ± 16.9), (41.7 ± 14.6), (41.4 ± 12.2) kg, respectively (χ(2) = 25.7, P < 0.01). In the period of 1991 to 2006, milk drinking rate and milk consumption has improved greatly. Main nutrient intake, height and weight increased with milk consumption.

  9. Increasing addition of autochthonous to allochthonous carbon in nutrient-rich aquatic systems stimulates carbon consumption but does not alter bacterial community composition

    NASA Astrophysics Data System (ADS)

    Attermeyer, K.; Hornick, T.; Kayler, Z. E.; Bahr, A.; Zwirnmann, E.; Grossart, H.-P.; Premke, K.

    2013-08-01

    Dissolved organic carbon (DOC) concentrations - mainly of terrestrial origin - are increasing worldwide in inland waters. The biodegradability of the DOC varies depending on quantity and chemical quality. Heterotrophic bacteria are the main consumers of DOC and thus determine DOC temporal dynamics and availability for higher trophic levels. It is therefore crucial to understand the processes controlling the bacterial turnover of additional allochthonous and autochthonous DOC in aquatic systems. Our aim was to study bacterial carbon (C) turnover with respect to DOC quantity and chemical quality using both allochthonous and autochthonous DOC sources. We incubated a natural bacterial community with allochthonous C (13C-labeled beech leachate) and increased concentrations and pulses (intermittent occurrence of organic matter input) of autochthonous C (algae lysate). We then determined bacterial carbon consumption, activities, and community composition together with the carbon flow through bacteria using stable C isotopes. The chemical analysis of single sources revealed differences in aromaticity and fractions of low and high molecular weight substances (LMWS and HMWS, respectively) between allochthonous and autochthonous C sources. In parallel to these differences in chemical composition, we observed a higher availability of allochthonous C as evidenced by increased DOC consumption and bacterial growth efficiencies (BGE) when solely allochthonous C was provided. In treatments with mixed sources, rising concentrations of added autochthonous DOC resulted in a further, significant increase in bacterial DOC consumption from 52 to 68% when nutrients were not limiting. This rise was accompanied by a decrease in the humic substances (HS) fraction and an increase in bacterial biomass. Stable C isotope analyses of phospholipid fatty acids (PLFA) and respired dissolved inorganic carbon (DIC) supported a preferential assimilation of autochthonous C and respiration of the

  10. Computational Model for Oxygen Transport and Consumption in Human Vitreous

    PubMed Central

    Filas, Benjamen A.; Shui, Ying-Bo; Beebe, David C.

    2013-01-01

    Purpose. Previous studies that measured liquefaction and oxygen content in human vitreous suggested that exposure of the lens to excess oxygen causes nuclear cataracts. Here, we developed a computational model that reproduced available experimental oxygen distributions for intact and degraded human vitreous in physiologic and environmentally perturbed conditions. After validation, the model was used to estimate how age-related changes in vitreous physiology and structure alter oxygen levels at the lens. Methods. A finite-element model for oxygen transport and consumption in the human vitreous was created. Major inputs included ascorbate-mediated oxygen consumption in the vitreous, consumption at the posterior lens surface, and inflow from the retinal vasculature. Concentration-dependent relations were determined from experimental human data or estimated from animal studies, with the impact of all assumptions explored via parameter studies. Results. The model reproduced experimental data in humans, including oxygen partial pressure (Po2) gradients (≈15 mm Hg) across the anterior-posterior extent of the vitreous body, higher oxygen levels at the pars plana relative to the vitreous core, increases in Po2 near the lens after cataract surgery, and equilibration in the vitreous chamber following vitrectomy. Loss of the antioxidative capacity of ascorbate increases oxygen levels 3-fold at the lens surface. Homogeneous vitreous degeneration (liquefaction), but not partial posterior vitreous detachment, greatly increases oxygen exposure to the lens. Conclusions. Ascorbate content and the structure of the vitreous gel are critical determinants of lens oxygen exposure. Minimally invasive surgery and restoration of vitreous structure warrant further attention as strategies for preventing nuclear cataracts. PMID:24008409

  11. Influence of maternal education on food consumption and energy and nutrient intake in a group of pre-school children from Madrid.

    PubMed

    Navia, B; Ortega, R M; Requejo, A M; Perea, J M; López-Sobaler, A M; Faci, M

    2003-11-01

    A study was conducted on the influence of maternal education level on food consumption, energy and nutrient intake, and dietary adequacy in 110 pre-school children from Madrid, Spain. With increasing maternal education, children consumed more sugar(p < 0.05), fruit (p < 0.05), and fish (p < 0.05). Snacking was more frequent with decreasing maternal education (p < 0.05). Though statistical significance was not reached, the consumption of pre-cooked foods was greater among children of mothers educated to a higher level, a phenomenon probably related to the work situation of these women. With respect to dietary composition, no significant differences were found between groups for macronutrient, fiber and energy intakes, except for energy supplied by polyunsaturated fatty acids (PUFA), which was greater in the children of less educated women (p < 0.01). This is probably due to their greater consumption of sunflower seed oil. The diets of children belonging to well-educated mothers came closer to meeting the recommended intakes for folate, vitamin C, and iodine. It would seem that maternal educational level influences the food habits of children. Mothers with less education may require special advice in this area.

  12. Short-Term Energy Outlook Model Documentation: Other Petroleum Products Consumption Model

    EIA Publications

    2011-01-01

    The other petroleum product consumption module of the Short-Term Energy Outlook (STEO) model is designed to provide U.S. consumption forecasts for 6 petroleum product categories: asphalt and road oil, petrochemical feedstocks, petroleum coke, refinery still gas, unfinished oils, and other miscvellaneous products

  13. Short-Term Energy Outlook Model Documentation: Other Petroleum Products Consumption Model

    EIA Publications

    2011-01-01

    The other petroleum product consumption module of the Short-Term Energy Outlook (STEO) model is designed to provide U.S. consumption forecasts for 6 petroleum product categories: asphalt and road oil, petrochemical feedstocks, petroleum coke, refinery still gas, unfinished oils, and other miscvellaneous products

  14. Dissolved Nutrient Retention Dynamics in River Networks: A Modeling Investigation of Transient Flow and Scale Effects

    SciTech Connect

    Ye, Sheng; Covino, Timothy P.; Sivapalan, Murugesu; Basu, Nandita; Li, Hongyi; Wang, Shaowen

    2012-06-30

    In this paper, we use a dynamic network flow model, coupled with a transient storage zone biogeochemical model, to simulate dissolved nutrient removal processes at the channel network scale. We have explored several scenarios in respect of the combination of rainfall variability, and the biological and geomorphic characteristics of the catchment, to understand the dominant controls on removal and delivery of dissolved nutrients (e.g., nitrate). These model-based theoretical analyses suggested that while nutrient removal efficiency is lower during flood events compared to during baseflow periods, flood events contribute significantly to bulk nutrient removal, whereas bulk removal during baseflow periods is less. This is due to the fact that nutrient supply is larger during flood events; this trend is even stronger in large rivers. However, the efficiency of removal during both periods decreases in larger rivers, however, due to (i) increasing flow velocities and thus decreasing residence time, and (ii) increasing flow depth, and thus decreasing nutrient uptake rates. Besides nutrient removal processes can be divided into two parts: in the main channel and in the hyporheic transient storage zone. When assessing their relative contributions the size of the transient storage zone is a dominant control, followed by uptake rates in the main channel and in the transient storage zone. Increasing size of the transient storage zone with downstream distance affects the relative contributions to nutrient removal of the water column and the transient storage zone, which also impacts the way nutrient removal rates scale with increasing size of rivers. Intra-annual hydrologic variability has a significant impact on removal rates at all scales: the more variable the streamflow is, compared to mean discharge, the less nutrient is removed in the channel network. A scale-independent first order uptake coefficient, ke, estimated from model simulations, is highly dependent on the

  15. Seasonal variability of nutrients in the Yangtze Estuary and adjacent waters: A model study

    NASA Astrophysics Data System (ADS)

    Zong, H.; Ding, P.

    2014-12-01

    Eutrophication has been one of the major threats to the coastal ecosystem. Several factors are believed to be associated with eutrophication, which including the high nutrient loads delivered into the estuary from river. Yangtze river is the longest river in China. It brings huge amount of nutrients into the Yangtze Estuary (YE) and adjacent East China Sea (ECS) and contributes significantly to the eutrophication in estuary and the adjacent waters. The eutrophication in this region exhibits strong seasonal variability, with the worst situation occurring in summer. This seasonal variability might be coupled with the timing of riverine nutrient inputs and physical processes (wind and along-shore current). To study seasonal variability of nutrients (N/P) in YE, a 3D physical-biological coupled model was applied to the YE and its adjacent waters. The physical model was the Regional Ocean Model System (ROMS) and the biological model was a nitrogen, phytoplankton, zooplankton, and detritus (NPZD) model. The simulated nutrients distribution pattern was consistent with observation. With the numerical experiments, we examined nutrients transport under different river loads and different physical processes. Seasonal variability of nutrients budget in YE and alone-shelf transport flux were also studied.

  16. [Effect of an ovo-lacto-vegetarian diet on nutrition and blood status. I. Method, food consumption, administration of nutrients and anthropometry].

    PubMed

    Wirths, W; Rehage-Thönes, C; Bönnhoff, N; Passelewitz, U

    1987-12-01

    The purpose of the study was to investigate the physiological assessment of a lacto-ovo-vegetarian diet, in comparison to a usual mixed diet and to analyse the effect of a lacto-ovo-vegetarian diet on nutritional status and blood parameters. Following an initial study, 34 resp. 33 subjects, three of them male took part in two investigation periods each lasting three weeks. During the first period (N) the subjects ingested the normal mixed diet, while in the second period (L) they were fed a lacto-ovo-vegetarian diet. The female subjects were aged 52.6 +/- 14.3 years, the male subjects 47.7 +/- 12.7 years. In both periods food supply ensued from the central kitchen of a nunnery. While preparing the meals, the food intake and the amount of nutrients was assessed with precise weighing methods. Also, the individual food consumption of the total subjects was estimated using food records. The nutritional physiological evaluation was based on the daily consumption of energy and nutrients to assess the nutrient supply, by means of the recommended dietary allowances of the German Nutrition Society. At the beginning of period N and both at the beginning and the end of period L, blood tests of the following parameters were performed: serum glucose, uric acid, and potassium, total protein, total cholesterol, HDL-, LDL-, VLDL-cholesterol, triglycerides, serum ferritin, serum iron, iron binding capacity, hemoglobin, s-GOT, s-GPT, thiamine, riboflavine, ascorbic acid. Measurements of body weight and height, body composition, skinfold thickness, circumferences, body surface, relative weight, blood pressure and sitting pulse rate completed the investigations. Furthermore, meal frequency and the daily individual energy requirement of the subjects were assessed by means of a diary of energy expenditure. On average, the daily energy consumption of women was 2020 +/- 611.3 kcal in period N, and 1970 +/- 592.4 kcal in period L. Consequently, there was a covering of energy requirements

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

  18. Modeling nutrient release in the Tai Lake basin of China: source identification and policy implications.

    PubMed

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

    2013-03-01

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

  19. Testing Two Nutrient Profiling Models of Labelled Foods and Beverages Marketed in Turkey.

    PubMed

    Dikmen, Derya; Kızıl, Mevlüde; Uyar, Muhemmet Fatih; Pekcan, Gülden

    2015-06-01

    The objective of this study was to evaluate the nutrient profile of labelled foods and also understand the application of two international nutrient profiling models of labelled foods and beverages. WXYfm and NRF 9.3 nutrient profiling models were used to evaluate 3,171 labelled foods and beverages of 38 food categories and 500 different brands. According to the WXYfm model, pasta, grains and legumes and frozen foods had the best scores whereas oils had the worst scores. According to the NRF 9.3 model per 100 kcal, the best scores were obtained for frozen foods, grains and legumes and milk products whereas the confectionery foods had the worst scores. According to NRF 9.3 per serving size, grains and legumes had the best scores and flavoured milks had the worst scores. A comparison of WXYfm and NRF 9.3 nutrient profiling models ranked scores showed a high positive correlation (p=0.01). The two nutrient models evaluated yielded similar results. Further studies are needed to test other category specific nutrient profiling models in order to understand how different models behave. Copyright© by the National Institute of Public Health, Prague 2015.

  20. Uniform modeling of bacterial colony patterns with varying nutrient and substrate

    NASA Astrophysics Data System (ADS)

    Schwarcz, Deborah; Levine, Herbert; Ben-Jacob, Eshel; Ariel, Gil

    2016-04-01

    Bacteria develop complex patterns depending on growth condition. For example, Bacillus subtilis exhibit five different patterns depending on substrate hardness and nutrient concentration. We present a unified integro-differential model that reproduces the entire experimentally observed morphology diagram at varying nutrient concentrations and substrate hardness. The model allows a comprehensive and quantitative comparison between experimental and numerical variables and parameters, such as colony growth rate, nutrient concentration and diffusion constants. As a result, the role of the different physical mechanisms underlying and regulating the growth of the colony can be evaluated.

  1. Turing instability and travelling waves in diffusive plankton models with delayed nutrient recycling

    NASA Astrophysics Data System (ADS)

    Ruan, S.

    1998-09-01

    In this paper we propose a reaction-diffusion system with two distributed delays to stimulate the growth of plankton communities in the lakes/oceans in which the plankton feeds on a limiting nutrient supplied at a constant rate. The limiting nutrient is partially recycled after the death of the organisms and a distributed delay is used to model nutrient recycling. The second delay is involved in the growth response of the plankton to nutrient uptake. We first show that there are oscillations (Hopf bifurcations) in the delay model induced by the second delay. Then we study Turing (diffusion-driven) instability of the reaction-diffusion system with delay. Finally, it is shown that if the delay model has a stable periodic solution, then the corresponding reaction-diffusion model with delay has a family of travelling waves.

  2. Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition

    EPA Science Inventory

    Boosted regression tree (BRT) models were developed to quantify the nonlinear relationships between landscape variables and nutrient concentrations in a mesoscale mixed land cover watershed during base-flow conditions. Factors that affect instream biological components, based on ...

  3. Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition

    EPA Science Inventory

    Boosted regression tree (BRT) models were developed to quantify the nonlinear relationships between landscape variables and nutrient concentrations in a mesoscale mixed land cover watershed during base-flow conditions. Factors that affect instream biological components, based on ...

  4. Materials flow modeling of nutrient recycling in biodiesel production from microalgae.

    PubMed

    Rösch, Christine; Skarka, Johannes; Wegerer, Nadja

    2012-03-01

    Biodiesel production based on microalgae as feedstock is associated with a high demand of nutrients, respectively nitrogen and phosphorus. The production of 1l biodiesel requires between 0.23 and 1.55 kg nitrogen and 29-145 g of phosphorus depending of the cultivation conditions for microalgae. The supply of nutrients can be expected to severely limit the extent to which the production of biofuels from microalgae can be sustainably expanded. The nutrient demand can be reduced if the nutrients in the residual algae biomass after oil extraction are reused for algae cultivation. This modeling work illustrates that for the investigated process chains and scenarios the nutrient recycling rates are in the range from 30% to 90% for nitrogen and from 48% to 93% for phosphorus. The highest recycling values can be achieved by hydrothermal gasification of the oil-free residues. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Effect of the method of preparation for consumption on calcium retention, calcium:phosphorus ratio, nutrient density and recommended daily allowance in fourteen vegetables.

    PubMed

    Słupski, Jacek; Gębczyński, Piotr; Korus, Anna; Lisiewska, Zofia

    2014-06-01

    The aim of this work was to evaluate calcium retention in 14 species of vegetable (from four usable groups). The material investigated consisted of raw and boiled fresh vegetables and two types of frozen product prepared for consumption after 12-month storage: one traditionally produced; the other obtained using the modified method (convenience food). The highest calcium content was found in leafy vegetables, followed (in descending order) by leguminous, root and brassica vegetables. The proportion by weight of Ca to P was highest in leafy vegetables and decreased with calcium retention despite the fact that levels of phosphorus were highest in leguminous and lowest in leafy vegetables. The nutrient density (ND%) of calcium for adults exceeded 100 for each individual vegetable species. The recommended daily allowance (RDA) percentage value varied between 23.04 (kale) and 1.46 (white cauliflower). Of the three types of product, ND and RDA values were generally greater in the frozen convenience products.

  6. Tree Nut Consumption Is Associated with Better Nutrient Adequacy and Diet Quality in Adults: National Health and Nutrition Examination Survey 2005–2010

    PubMed Central

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

    2015-01-01

    Nutrient adequacy of tree nut consumers has not been examined. The National Health and Nutrition Examination Survey 2005–2010 data were used to assess the association of tree nut consumption by adults 19+ years (n = 14,386) with nutrient adequacy and diet quality. Covariate adjusted usual intake was determined using two 24-h dietary recalls and the National Cancer Institute method. Percentages of the consumption groups below the Estimated Average Requirement (EAR) or above the Adequate Intake (AI) were determined. Diet quality was determined using the Healthy Eating Index-2005 (HEI) score. Usual intake data showed consumers of tree nuts had a lower percentage (p < 0.0001) of the population below the EAR for vitamins A (22 ± 5 vs. 49 ± 1), E (38 ± 4 vs. 94 ± 0.4) and C (17 ± 4 vs. 44 ± 1); folate (2.5 ± 1.5 vs. 12 ± 0.6); calcium (26 ± 3 vs. 44 ± 1); iron (3 ± 0.6 vs. 9 ± 0.4); magnesium (8 ± 1 vs. 60 ± 1); and zinc (1.5 ± 1 vs. 13 ± 1). Tree nut consumers had a higher percentage (p < 0.0001) of the population above the AI for fiber (33 ± 3 vs. 4 ± 0.3) and potassium (12 ± 3 mg vs. 2 ± 0.2 mg). HEI-2005 total score was higher (p < 0.0001) in tree nut consumers (61 ± 0.7 vs. 52 ± 0.3) than non-consumers. Health professionals should encourage the use of tree nuts as part of a dietary approach to healthy eating. PMID:25599274

  7. Association of lunch meat consumption with nutrient intake, diet quality and health risk factors in U.S. children and adults: NHANES 2007-2010.

    PubMed

    Agarwal, Sanjiv; Fulgoni, Victor L; Berg, Eric P

    2015-12-30

    Consumption of lean meat is recommended as part of healthy diet by Dietary Guidelines for Americans, 2010. Lunch meats are precooked or cured meats typically used in sandwiches and are also called as cold cuts or deli meat. The purpose of the study was to examine the association of lunch meat consumption with nutrient intake, diet quality, and physiological measures in children (age 2-18 years; n = 5,099) and adults (age 19 years and older; n = 10,216) using a large, nationally representative database. Lunch meat consumers were defined as those consuming any amount of lunch meat during a 24-h recall and association with nutrient intake, diet quality (Healthy Eating Index (HEI)-2010 score) and physiological measures were evaluated using the National Health and Nutrition Examination Survey (NHANES), 2007-2010. The lunch meat consumers (both children and adults) had higher intakes of calories, protein, calcium, potassium, sodium and saturated fat (for adults only) compared to non-consumers. Lunch meat intake was also associated with higher intake of meat/poultry/fish food group in both children and adult consumers than non-consumers. There was no difference in total HEI-2010 scores comparing lunch meat consumers and non-consumers in children or adults. However, HEI components scores for total fruit, whole fruit (children only), whole grains, dairy and total protein foods were significantly higher, and for greens & beans (adults only), seafood and plant protein, fatty acid ratio and sodium were significantly lower in children and adult lunch meat consumers compared to non-consumers. There were no significant differences in physiological measures or in the odds ratios of health related conditions between lunch meat consumers and non-consumers in children or adults. The results of this study may provide insight into how to better utilize lunch meats in the diets of U.S. children and adults.

  8. Modeling brine and nutrient dynamics in Antarctic sea ice: the case of dissolved silica

    NASA Astrophysics Data System (ADS)

    Vancoppenolle, M.; Goosse, H.; de Montety, A.; Fichefet, T.; Tremblay, B.; Tison, J.

    2009-12-01

    Sea ice ecosystems are characterized by micro-algae living in brine inclusions. The growth rate of ice algae depends on light and nutrient supply. Here, the interactions between nutrients and brine dynamics under the influence of algae are investigated using a one-dimensional model. The model includes snow and ice thermodynamics with brine physics and an idealized sea ice biological component, characterized by one nutrient, namely dissolved silica (DSi). In the model, DSi follows brine motion and is consumed by ice algae. Depending on physical ice characteristics, the brine flow is either advective, diffusive or turbulent. The vertical profiles of ice salinity and DSi concentration are solutions of advection-diffusion equations. The model is configured to simulate the typical thermodynamic regimes of first-year Antarctic pack ice. The simulated vertical profiles of salinity and DSi qualitatively reproduce observations. Analysis of results highlights the role of convection in the lowermost 5-10 cm of ice. Convection mixes saline, nutrient-poor brine with comparatively fresh, nutrient-rich seawater. This implies a rejection of salt to the ocean and a flux of DSi to the ice. In presence of growing algae, the simulated ocean-to-ice DSi flux increases by 0-115% compared to an abiotic situation. In turn, primary production and brine convection act in synergy to form a nutrient pump. The other important processes are the flooding of the surface by seawater and the percolation of meltwater. The former refills nutrients near the ice surface in spring. The latter, if present, tends to expell nutrients from the ice in summer. Sketch of salt (left) and nutrient (right) exchanges at the ice-ocean interface proposed in this paper.

  9. Linking nutrient loading and oxygen in the coastal ocean: A new global scale model

    NASA Astrophysics Data System (ADS)

    Reed, Daniel C.; Harrison, John A.

    2016-03-01

    Recent decades have witnessed an exponential spread of low-oxygen regions in the coastal ocean due at least in-part to enhanced terrestrial nutrient inputs. As oxygen deprivation is a major stressor on marine ecosystems, there is a great need to quantitatively link shifts in nutrient loading with changes in oxygen concentrations. To this end, we have developed and here describe, evaluate, and apply the Coastal Ocean Oxygen Linked to Benthic Exchange And Nutrient Supply (COOLBEANS) model, a first-of-its-kind, spatially explicit (with 152 coastal segments) model, global model of coastal oxygen and nutrient dynamics. In COOLBEANS, benthic oxygen demand (BOD) is calculated using empirical models for aerobic respiration, iron reduction, and sulfate reduction, while oxygen supply is represented by a simple parameterization of exchange between surface and bottom waters. A nutrient cycling component translates shifts in riverine nutrient inputs into changes in organic matter delivery to sediments and, ultimately, oxygen uptake. Modeled BOD reproduces observations reasonably well (Nash-Sutcliffe efficiency = 0.71), and estimates of exchange between surface and bottom waters correlate with stratification. The model examines sensitivity of bottom water oxygen to changes in nutrient inputs and vertical exchange between surface and bottom waters, highlighting the importance of this vertical exchange in defining the susceptibility of a system to oxygen depletion. These sensitivities along with estimated maximum hypoxic areas that are supported by present day nutrient loads are consistent with existing hypoxic regions. Sensitivities are put into context by applying historic changes in nitrogen loading observed in the Gulf of Mexico to the global coastal ocean, demonstrating that such loads would drive many systems anoxic or even sulfidic.

  10. Evaluation models for soil nutrient based on support vector machine and artificial neural networks.

    PubMed

    Li, Hao; Leng, Weijia; Zhou, Yibing; Chen, Fudi; Xiu, Zhilong; Yang, Dazuo

    2014-01-01

    Soil nutrient is an important aspect that contributes to the soil fertility and environmental effects. Traditional evaluation approaches of soil nutrient are quite hard to operate, making great difficulties in practical applications. In this paper, we present a series of comprehensive evaluation models for soil nutrient by using support vector machine (SVM), multiple linear regression (MLR), and artificial neural networks (ANNs), respectively. We took the content of organic matter, total nitrogen, alkali-hydrolysable nitrogen, rapidly available phosphorus, and rapidly available potassium as independent variables, while the evaluation level of soil nutrient content was taken as dependent variable. Results show that the average prediction accuracies of SVM models are 77.87% and 83.00%, respectively, while the general regression neural network (GRNN) model's average prediction accuracy is 92.86%, indicating that SVM and GRNN models can be used effectively to assess the levels of soil nutrient with suitable dependent variables. In practical applications, both SVM and GRNN models can be used for determining the levels of soil nutrient.

  11. Modelling phytoplankton succession and nutrient transfer along the Scheldt estuary (Belgium, The Netherlands)

    NASA Astrophysics Data System (ADS)

    Gypens, N.; Delhez, E.; Vanhoutte-Brunier, A.; Burton, S.; Thieu, V.; Passy, P.; Liu, Y.; Callens, J.; Rousseau, V.; Lancelot, C.

    2013-12-01

    The freshwater (RIVE) and the marine (MIRO) biogeochemical models were coupled to a 1D hydro-sedimentary model to describe contemporary phytoplankton succession and nutrient transfers in the macrotidal Scheldt estuary (BE/NL) affected by anthropogenic nutrient loads. The 1D-RIVE-MIRO model simulations are performed between Ghent and Vlissingen and the longitudinal estuarine profiles are validated by visual and statistical comparison with physico-chemical and phytoplankton observations available for the year 2006. Results show the occurrence of two distinct spatial phytoplankton blooms in the upper and lower estuary, suggesting that neither the freshwater nor the marine phytoplankton gets over the maximum turbidity zone (MTZ) at the saline transition. Sensitivity tests performed to understand how changing conditions (salinity, turbidity and nutrients) along the estuary are controlling this bimodal spatial phytoplankton distribution identify salinity and light availability as the key drivers while the grazing pressure and nutrient limitation play a negligible role. Additional tests with varying salinity-resistant (euryhaline) species in the freshwater assemblage conclude that the presence (or absence) of euryhalines determines the magnitude and the spreading of freshwater and marine phytoplankton blooms in the estuary. Annual nutrient budgets estimated from 1D-RIVE-MIRO simulations show that biological activities have a negligible impact on nutrient export but modify the speciation of nutrients exported to the coastal zone towards inorganic forms, thus directly available to phytoplankton. The implementation of nutrient reduction options (upgrading of waste water treatment plants, conversion to organic farming) on the Scheldt watershed influences the whole estuary and affects both the magnitude and the speciation of nutrients exported to the coastal zone with expected impact on coastal phytoplankton dynamic.

  12. Stressor-Response Models Relating Nutrient Enrichment to Algal Communities in Pacific Northwest Streams and Rivers

    NASA Astrophysics Data System (ADS)

    Sobota, D. J.; Hubler, S.; Paul, M. J.; Labiosa, R.

    2015-12-01

    Excessive algal growth in streams and rivers from nutrient enrichment can cause costly human health and environmental problems. As part of the US Environmental Protection Agency's Nutrient Scientific Technical Exchange Partnership and Support (N-STEPS) program, we have been developing stressor-response (S-R) models relating nutrients to attached algal (periphyton) communities to help prioritize monitoring for water quality impairments in Oregon (Pacific Northwest, USA) streams and rivers. Existing data from the state and neighboring states were compiled and standardized from the Oregon Department of Environmental Quality, US Environmental Protection Agency, and the US Geological Survey. To develop S-R models, algal community and biomass metrics were compared with nitrogen (N) and phosphorus (P) concentration data, including total, dissolved, and inorganic forms of these nutrients. In total, 928 paired algal-nutrient samples were compiled from the 8 Level-III Ecoregions occurring in Oregon. Relationships between algal biomass metrics and nutrient concentrations were weak, with only ash-free dry mass and standing stock of chlorophyll a showing slight positive relationships across gradients of total N and soluble reactive P concentrations, respectively. In contrast, metrics describing algal community composition, including percent diatoms and abundance of nutrient-sensitive species, showed very strong nonlinear relationships with total N or P concentrations. This suggests that data describing algal community composition can help identify specific nutrient stressors across environmentally-diverse streams and rivers in the Pacific Northwest. Future analyses will examine if nutrient-algal S-R models vary across different hydrological, physiographical, and ecological settings in the region.

  13. A new theory of plant-microbe nutrient competition resolves inconsistencies between observations and model predictions.

    PubMed

    Zhu, Qing; Riley, William J; Tang, Jinyun

    2017-04-01

    Terrestrial plants assimilate anthropogenic CO2 through photosynthesis and synthesizing new tissues. However, sustaining these processes requires plants to compete with microbes for soil nutrients, which therefore calls for an appropriate understanding and modeling of nutrient competition mechanisms in Earth System Models (ESMs). Here, we survey existing plant-microbe competition theories and their implementations in ESMs. We found no consensus regarding the representation of nutrient competition and that observational and theoretical support for current implementations are weak. To reconcile this situation, we applied the Equilibrium Chemistry Approximation (ECA) theory to plant-microbe nitrogen competition in a detailed grassland (15) N tracer study and found that competition theories in current ESMs fail to capture observed patterns and the ECA prediction simplifies the complex nature of nutrient competition and quantitatively matches the (15) N observations. Since plant carbon dynamics are strongly modulated by soil nutrient acquisition, we conclude that (1) predicted nutrient limitation effects on terrestrial carbon accumulation by existing ESMs may be biased and (2) our ECA-based approach may improve predictions by mechanistically representing plant-microbe nutrient competition.

  14. Application of Hierarchy Theory to Cross-Scale Hydrologic Modeling of Nutrient Loads

    EPA Science Inventory

    We describe a model called Regional Hydrologic Modeling for Environmental Evaluation 16 (RHyME2) for quantifying annual nutrient loads in stream networks and watersheds. RHyME2 is 17 a cross-scale statistical and process-based water-quality model. The model ...

  15. Application of Hierarchy Theory to Cross-Scale Hydrologic Modeling of Nutrient Loads

    EPA Science Inventory

    We describe a model called Regional Hydrologic Modeling for Environmental Evaluation 16 (RHyME2) for quantifying annual nutrient loads in stream networks and watersheds. RHyME2 is 17 a cross-scale statistical and process-based water-quality model. The model ...

  16. Early sugar-sweetened beverage consumption frequency is associated with poor quality of later food and nutrient intake patterns among Japanese young children: the Osaka Maternal and Child Health Study.

    PubMed

    Okubo, Hitomi; Miyake, Yoshihiro; Sasaki, Satoshi; Tanaka, Keiko; Hirota, Yoshio

    2016-06-01

    Evidence from Western countries shows that higher consumption of sugar-sweetened beverages (SSBs) is associated with lower quality of young children's diets, but little is known about these relations in non-Western countries with relatively low consumption levels of SSBs. We hypothesized that SSB consumption in infancy would be associated with poor quality of later food and nutrient intake patterns among Japanese young children. The study subjects were 493 Japanese mother-child pairs from a prospective birth cohort study. Dietary data on children were collected from the mothers using self-administered questionnaires when the children were aged 16-24 months and 41-49 months. Multiple linear regression analyses were used to examine the relationships between SSB consumption frequency in infancy and later intake of foods and nutrients. At 16-24 months of age, more than half of the children (56.4%) consumed SSBs less than once a week, whereas 11.6% consumed SSBs at least once daily. More frequent consumption of SSBs in infancy was associated with higher intake of confectionaries and SSBs and lower intake of fruits and vegetables at 41-49 months of age. These associations were still evident after adjustment for maternal SSB consumption and socioeconomic status. At the nutrient level, SSB consumption frequency was positively associated with energy intake and inversely associated with intake of many nutrients, such as protein, dietary fiber, and most of the micronutrients examined. In conclusion, higher consumption frequency of SSBs at an early age is associated with poor quality of overall dietary intake among young Japanese children 1.5-2.5 years later. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. [Consumption of nutrients among the elderly living in Porto Alegre in the State of Rio Grande do Sul, Brazil: a population-based study].

    PubMed

    Venturini, Carina Duarte; Engroff, Paula; Sgnaolin, Vanessa; El Kik, Raquel Milani; Morrone, Fernanda Bueno; da Silva Filho, Irenio Gomes; De Carli, Geraldo Attilio

    2015-12-01

    A cross-sectional, population-based study was conducted on a random sample of 427 elderly individuals living in Porto Alegre, Brazil, to establish the nutrient consumption profile and verify its association with sociodemographic and health variables. Dietary intake was assessed using the 24-hour Food Recall Survey and the Dietetic Research Investigation technique. Seventy percent of the elderly respondents were women: 48.5% were between 60 and 69 years old; 68.8% had less than 8 years of schooling; 39% had a family income of between 2 and 5 minimum wages and 58.4% took no physical exercise. Hypertension was the most prevalent disease among the elderly and 54.9% were underweight. Men consumed more calories, protein, fiber, minerals and vitamins than women. Carbohydrate and calcium intake increases with advancing age, while zinc intake decreases. Physical exercise increased the intake of calories, magnesium, potassium and phosphorus. The higher the schooling the greater the intake of vitamins B6 and B12; the higher the family income, the greater the consumption of vitamin B6 and folic acid. The results show that there are nutritional deficiencies in the daily diet of the Brazilian elderly population, especially among women and individuals over 80 years of age.

  18. A Geographic Information System approach to modeling nutrient and sediment transport

    SciTech Connect

    Levine, D.A.; Hunsaker, C.T.; Beauchamp, J.J.; Timmins, S.P.

    1993-02-01

    The objective of this study was to develop a water quality model to quantify nonpoint-source (NPS) pollution that uses a geographic information system (GIS) to link statistical modeling of nutrient and sediment delivery with the spatial arrangement of the parameters that drive the model. The model predicts annual nutrient and sediment loading and was developed, calibrated, and tested on 12 watersheds within the Lake Ray Roberts drainage basin in north Texas. Three physiographic regions are represented by these watersheds, and model success, as measured by the accuracy of load estimates, was compared within and across these regions.

  19. One hundred percent orange juice consumption is associated with better diet quality, improved nutrient adequacy, and no increased risk for overweight/obesity in children.

    PubMed

    O'Neil, Carol E; Nicklas, Theresa A; Rampersaud, Gail C; Fulgoni, Victor L

    2011-09-01

    The purpose of this study was to examine the association of 100% orange juice (OJ) consumption by children 2 to 18 years of age (n = 7250) participating in the 2003 to 2006 National Health and Nutrition Examination Survey with intakes of select nutrients, MyPyramid food groups, diet quality-measured by the Healthy Eating Index-2005, weight status, and associated risk factors. The National Cancer Institute method was used to estimate the usual intake of 100% OJ consumption, selected nutrients, and MyPyramid food groups. Percentages of the population below the Estimated Average Requirement were determined. Covariate adjusted logistic regression was used to determine if consumers had a lower odds ratio of being overweight or obese. Usual per capita intake of 100% OJ was 1.7 oz/d. Among consumers, the usual intake of 100% OJ for children (n = 2183; 26.2% of population) was 10.2 oz/d. Consumers had higher (P < .05) energy intakes than nonconsumers (9148 ± 113 vs 8625 ± 473 kJ). However, there were no differences in weight or body mass index in consumers and nonconsumers, and there was no significant difference in the risk of being overweight or obese between consumers and nonconsumers (odds ratio, 0.86; 95% confidence interval, 0.70-1.05). Compared with nonconsumers, consumers had a higher (P < .01) percentage (% ± SE) of the population meeting the Estimated Average Requirement for vitamin A (19.6 ± 2.0 vs 30.2 ± 1.4), vitamin C (0.0 ± 0.0 vs 29.2 ± 1.2), folate (1.3 ± 0.3 vs 5.1 ± 0.6), and magnesium (25.5 ± 2.0 vs 39.0 ± 11). The Healthy Eating Index-2005 was significantly (P < .01) higher in consumers (52.4 ± 0.4 vs 48.5 ± 0.3). Consumers also had higher intakes of total fruit, fruit juice, and whole fruit. Moderate consumption of 100% OJ should be encouraged in children as a component of a healthy diet. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. A mathematical model of water and nutrient transport in xylem vessels of a wheat plant.

    PubMed

    Payvandi, S; Daly, K R; Jones, D L; Talboys, P; Zygalakis, K C; Roose, T

    2014-03-01

    At a time of increasing global demand for food, dwindling land and resources, and escalating pressures from climate change, the farming industry is undergoing financial strain, with a need to improve efficiency and crop yields. In order to improve efficiencies in farming, and in fertiliser usage in particular, understanding must be gained of the fertiliser-to-crop-yield pathway. We model one aspect of this pathway; the transport of nutrients within the vascular tissues of a crop plant from roots to leaves. We present a mathematical model of the transport of nutrients within the xylem vessels in response to the evapotranspiration of water. We determine seven different classes of flow, including positive unidirectional flow, which is optimal for nutrient transport from the roots to the leaves; and root multidirectional flow, which is similar to the hydraulic lift process observed in plants. We also investigate the effect of diffusion on nutrient transport and find that diffusion can be significant at the vessel termini especially if there is an axial efflux of nutrient, and at night when transpiration is minimal. Models such as these can then be coupled to whole-plant models to be used for optimisation of nutrient delivery scenarios.

  1. Water quality in Atlantic rainforest mountain rivers (South America): quality indices assessment, nutrients distribution, and consumption effect.

    PubMed

    Avigliano, Esteban; Schenone, Nahuel

    2016-08-01

    The South American Atlantic rainforest is a one-of-a-kind ecosystem considered as a biodiversity hotspot; however, in the last decades, it was intensively reduced to 7 % of its original surface. Water resources and water quality are one of the main goods and services this system provides to people. For monitoring and management recommendations, the present study is focused on (1) determining the nutrient content (nitrate, nitrite, ammonium, and phosphate) and physiochemical parameters (temperature, pH, electrical conductivity, turbidity, dissolved oxygen, and total dissolved solids) in surface water from 24 rainforest mountain rivers in Argentina, (2) analyzing the human health risk, (3) assessing the environmental distribution of the determined pollutants, and (4) analyzing water quality indices (WQIobj and WQImin). In addition, for total coliform bacteria, a dataset was used from literature. Turbidity, total dissolved solids, and nitrite (NO2 (-)) exceeded the guideline value recommended by national or international guidelines in several sampling stations. The spatial distribution pattern was analyzed by Principal Component Analysis and Factor Analysis (PCA/FA) showing well-defined groups of rivers. Both WQI showed good adjustment (R (2) = 0.89) and rated water quality as good or excellent in all sampling sites (WQI > 71). Therefore, this study suggests the use of the WQImin for monitoring water quality in the region and also the water treatment of coliform, total dissolved solids, and turbidity.

  2. Sensitivity of Hypoxia Predictions for the Northern Gulf of Mexico to Sediment Oxygen Consumption and Model Nesting

    NASA Astrophysics Data System (ADS)

    Fennel, Katja; Hu, Jiatang; Laurent, Arnaud; Marta-Almeida, Martinho; Hetland, Robert

    2014-05-01

    Interannual variations of the hypoxic area that develops every summer over the Texas-Louisiana Shelf are large. The 2008 Action Plan put forth by an alliance of multiple state and federal agencies and tribes calls for a decrease of the hypoxic area through nutrient management in the watershed. Realistic models help build mechanistic understanding of the processes underlying hypoxia formation and are thus indispensable for devising efficient nutrient reduction strategies. Here we present such a model, evaluate its hypoxia predictions against monitoring observations and assess the sensitivity of hypoxia predictions to model resolution, variations in sediment oxygen consumption and choice of physical horizontal boundary conditions. We find that hypoxia predictions on the shelf are very sensitive to the parameterization of sediment oxygen consumption, a result of the fact that hypoxic conditions are restricted to a relatively thin layer above the bottom over most of the shelf. We also show that the strength of vertical stratification is an important predictor of oxygen concentration in bottom waters and that modification of physical horizontal boundary conditions can have a large effect on hypoxia predictions.

  3. The Federal Highway Administration Gasohol Consumption Estimation Model

    SciTech Connect

    Hwang, HL

    2003-08-28

    The Federal Highway Administration (FHWA) is responsible for estimating the portion of Federal highway funds attributable to each State. The process involves use of State-reported data (gallons) and a set of estimation models when accurate State data is unavailable. To ensure that the distribution of funds is equitable, FHWA periodically reviews the estimation models. Estimation of the use of gasohol is difficult because of State differences in the definition of gasohol, inability of many States to separate and report gasohol usage from other fuel types, changes in fuel composition in nonattainment areas to address concerns over the use of certain fuel additives, and the lack of a valid State-level surrogate data set for gasohol use. Under the sponsorship of FHWA, Oak Ridge National Laboratory (ORNL) reviewed the regression-based gasohol estimation model that has been in use for several years. Based on an analytical assessment of that model and an extensive review of potential data sets, ORNL developed an improved rule-based model. The new model uses data from Internal Revenue Service, Energy Information Administration, Environmental Protection Agency, Department of Energy, ORNL, and FHWA sources. The model basically consists of three parts: (1) development of a controlled total of national gasohol usage, (2) determination of reliable State gasohol consumption data, and (3) estimation of gasohol usage for all other States. The new model will be employed for the 2004 attribution process. FHWA is currently soliciting comments and inputs from interested parties. Relevant data, as identified, will be pursued and refinements will be made by the research team if warranted.

  4. Modeling energy expenditure and oxygen consumption in human exposure models: accounting for fatigue and EPOC.

    PubMed

    Isaacs, Kristin; Glen, Graham; Mccurdy, Thomas; Smith, Luther

    2008-05-01

    Human exposure and dose models often require a quantification of oxygen consumption for a simulated individual. Oxygen consumption is dependent on the modeled individual's physical activity level as described in an activity diary. Activity level is quantified via standardized values of metabolic equivalents of work (METS) for the activity being performed and converted into activity-specific oxygen consumption estimates. However, oxygen consumption remains elevated after a moderate- or high-intensity activity is completed. This effect, which is termed excess post-exercise oxygen consumption (EPOC), requires upward adjustment of the METS estimates that follow high-energy expenditure events, to model subsequent increased ventilation and intake dose rates. In addition, since an individual's capacity for work decreases during extended activity, methods are also required to adjust downward those METS estimates that exceed physiologically realistic limits over time. A unified method for simultaneously performing these adjustments is developed. The method simulates a cumulative oxygen deficit for each individual and uses it to impose appropriate time-dependent reductions in the METS time series and additions for EPOC. The relationships between the oxygen deficit and METS limits are nonlinear and are derived from published data on work capacity and oxygen consumption. These modifications result in improved modeling of ventilation patterns, and should improve intake dose estimates associated with exposure to airborne environmental contaminants.

  5. Nutritional Status of Preschool Children in Andaman and Nicobar Islands and Food Insecurity, Food Groups, and Nutrient Consumption among Population.

    PubMed

    Manimunda, Sathya P; Sugunan, Attayuru P

    2017-01-01

    Childhood undernutrition is a public health concern in India. But on such a serious issue, there are no data available from the Union Territory of Andaman and Nicobar (A and N) Islands. Present study was designed to know the prevalence of food insecurity, to estimate food group and nutrient intake among the community, and undernutrition and clinical signs of micronutrient deficiency among the preschool children of A and N islands. Multistage random sampling was followed to select the households containing children aged 6-59 months. In the selected households' sociodemographic particulars, Household Food Insecurity Access Scale (HFIAS), among preschoolers the weight and height were recorded along with the documentation of clinical signs of micronutrient deficiency, morbidities suffered over previous fortnight, and measurement of hemoglobin. Diet survey was carried out in every fourth household. A total of 1259 preschoolers residing in 1082 households were examined, HFIAS was measured in 710 households in Andaman group of islands and diet survey was conducted in 290 households. The prevalence of undernutrition was around 27%, stunting was 36%, and anemia was around 81%. Undernutrition and anemia prevalence were significantly low among Nicobarese children. After adjusting for all the determinants, tribal in domicile had favorable outcome [odds ratio (OR): 0.28 (0.18, 0.43)], while below poverty line family had adverse outcome on undernutrition [OR: 1.72 (1.20, 2.46)]. Though the prevalence of undernutrition is relatively low in the islands, but high prevalence of anemia needs to be addressed. Nicobarese children fare better in almost all indicators of nutritional well-being except for stunting. The prevalence of undernutrition is relatively low in Andaman and Nicobar Islands. Nicobarese children fare better in almost all indicators of nutritional well-being. However high prevalence of stunting among Nicobarese children needs further research with appropriate

  6. Changes of Dietary Pattern, Food Choice, Food Consumption, Nutrient Intake and Body Mass Index of Korean American College Students with Different Length of Residence in the Los Angeles Areas

    ERIC Educational Resources Information Center

    Kim, Nam; Tam, Chick F.; Poon, George; Lew, Polong; Kim, Samuel Saychang; Kim, James C.; Kim, Rachel Byungsook

    2010-01-01

    This study was to investigate how dietary pattern, food choice, food consumption, nutrient intake and body mass index (BMI) vary with length of residence for Korean American college students. The respondents were 60 Korean American residents living in the Los Angeles Area. They were divided into two groups based on the length of stay in the U.S.:…

  7. Changes of Dietary Pattern, Food Choice, Food Consumption, Nutrient Intake and Body Mass Index of Korean American College Students with Different Length of Residence in the Los Angeles Areas

    ERIC Educational Resources Information Center

    Kim, Nam; Tam, Chick F.; Poon, George; Lew, Polong; Kim, Samuel Saychang; Kim, James C.; Kim, Rachel Byungsook

    2010-01-01

    This study was to investigate how dietary pattern, food choice, food consumption, nutrient intake and body mass index (BMI) vary with length of residence for Korean American college students. The respondents were 60 Korean American residents living in the Los Angeles Area. They were divided into two groups based on the length of stay in the U.S.:…

  8. Nutritional Status of Preschool Children in Andaman and Nicobar Islands and Food Insecurity, Food Groups, and Nutrient Consumption among Population

    PubMed Central

    Manimunda, Sathya P; Sugunan, Attayuru P

    2017-01-01

    Background: Childhood undernutrition is a public health concern in India. But on such a serious issue, there are no data available from the Union Territory of Andaman and Nicobar (A and N) Islands. Objectives: Present study was designed to know the prevalence of food insecurity, to estimate food group and nutrient intake among the community, and undernutrition and clinical signs of micronutrient deficiency among the preschool children of A and N islands. Materials and Methods: Multistage random sampling was followed to select the households containing children aged 6-59 months. In the selected households' sociodemographic particulars, Household Food Insecurity Access Scale (HFIAS), among preschoolers the weight and height were recorded along with the documentation of clinical signs of micronutrient deficiency, morbidities suffered over previous fortnight, and measurement of hemoglobin. Diet survey was carried out in every fourth household. Results: A total of 1259 preschoolers residing in 1082 households were examined, HFIAS was measured in 710 households in Andaman group of islands and diet survey was conducted in 290 households. The prevalence of undernutrition was around 27%, stunting was 36%, and anemia was around 81%. Undernutrition and anemia prevalence were significantly low among Nicobarese children. After adjusting for all the determinants, tribal in domicile had favorable outcome [odds ratio (OR): 0.28 (0.18, 0.43)], while below poverty line family had adverse outcome on undernutrition [OR: 1.72 (1.20, 2.46)]. Conclusion: Though the prevalence of undernutrition is relatively low in the islands, but high prevalence of anemia needs to be addressed. Nicobarese children fare better in almost all indicators of nutritional well-being except for stunting. Key Messages: The prevalence of undernutrition is relatively low in Andaman and Nicobar Islands. Nicobarese children fare better in almost all indicators of nutritional well-being. However high prevalence of

  9. Hybrid mice as genetic models of high alcohol consumption.

    PubMed

    Blednov, Y A; Ozburn, A R; Walker, D; Ahmed, S; Belknap, J K; Harris, R A

    2010-01-01

    We showed that F1 hybrid genotypes may provide a broader variety of ethanol drinking phenotypes than the inbred progenitor strains used to create the hybrids (Blednov et al. in Alcohol Clin Exp Res 29:1949-1958, 2005). To extend this work, we characterized alcohol consumption as well as intake of other tastants (saccharin, quinine and sodium chloride) in five inbred strains of mice (FVB, SJL, B6, BUB, NZB) and in their reciprocal F1 hybrids with B6 (FVBxB6; B6xFVB; NZBxB6; B6xNZB; BUBxB6; B6xBUB; SJLxB6; B6xSJL). We also compared ethanol intake in these mice for several concentrations before and after two periods of abstinence. F1 hybrid mice derived from the crosses of B6 and FVB and also B6 and SJL drank higher levels of ethanol than their progenitor strains, demonstrating overdominance for two-bottle choice drinking test. The B6 and NZB hybrid showed additivity in two-bottle choice drinking, whereas the hybrid of B6 and BUB demonstrated full or complete dominance. Genealogical origin, as well as non-alcohol taste preferences (sodium chloride), predicted ethanol consumption. Mice derived from the crosses of B6 and FVB showed high sustained alcohol preference and the B6 and NZB hybrids showed reduced alcohol preference after periods of abstinence. These new genetic models offer some advantages over inbred strains because they provide high, sustained, alcohol intake, and should allow mapping of loci important for the genetic architecture of these traits.

  10. Nutrient Intakes: Individuals in 48 States, Year 1977-78. Nationwide Food Consumption Survey 1977-78. Report No. I-2.

    ERIC Educational Resources Information Center

    Department of Agriculture, Washington, DC.

    This report presents 3-day nutrient intake data for about 36,100 individuals in 48 states. Data are provided in 157 tables, and results are summarized in the text. The contribution of 14 food groups to intakes of food energy and 14 nutrients are presented. Also included are the average intakes of food energy and nutrients, the nutrient densities…

  11. Regional scale nutrient modelling: exports to the Great Barrier Reef World Heritage Area.

    PubMed

    McKergow, Lucy A; Prosser, Ian P; Hughes, Andrew O; Brodie, Jon

    2005-01-01

    Clearing of native vegetation and replacement with cropping and grazing systems has increased nutrient exports to the Great Barrier Reef (GBR) to a level many times the natural rate. We present a technique for modelling nutrient transport, based on material budgets of river systems, and use it to identify the patterns and sources of nutrients exported. The outputs of the model can then be used to help prioritise catchment areas and land uses for management and assess various management options. Hillslope erosion is the largest source of particulate nutrients because of its dominance as a sediment source and the higher nutrient concentrations on surface soils. Dissolved nutrient fractions contribute 30% of total nitrogen and 15% of total phosphorus inputs. Spatial patterns show the elevated dissolved inorganic nitrogen export in the wetter catchments, and the dominance of particulate N and P from soil erosion in coastal areas. This study has identified catchments with high levels of contribution to exports and targeting these should be a priority.

  12. Improved Hypoxia Modeling for Nutrient Control Decisions in the Gulf of Mexico

    NASA Technical Reports Server (NTRS)

    Habib, Shaid; Pickering, Ken; Tzortziou, Maria; Maninio, Antonio; Policelli, Fritz

    2010-01-01

    As required by the Harmful Algal Bloom and Hypoxia Research Control Act of 1998, the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force issued the 2001 Gulf Hypoxia Action Plan (updated in 2008). In response to the Gulf Hypoxia Action Plan of 2001 (updated in 2008), the EPA Gulf of Mexico Hypoxia Modeling and Monitoring Project has established a detailed model for the Mississippi-Attchafalaya River Basin which provides a capability to forecast the multi-source nutrient loading to the Gulf and the subsequent bio-geochemical processes leading to hypoxic conditions and subsequent effects on Gulf habitats and fisheries. The primary purpose of the EPA model is to characterize the impacts of nutrient management actions, or proposed actions on the spatial and temporal characteristics of the Gulf hypoxic zone. The model is expected to play a significant role in determining best practices and improved strategies for incentivizing nutrient reduction strategies, including installation of on-farm structures to reduce sediment and nutrient runoff, use of cover crops and other agricultural practices, restoration of wetlands and riparian buffers, improved waste water treatment and decreased industrial nitrogen emissions. These decisions are currently made in a fragmented way by federal, state, and local agencies, using a variety of small scale models and limited data. During the past three years, EPA has collected an enormous amount of in-situ data to be used in the model. We believe that the use of NASA satellite data products in the model and for long term validation of the model has the potential to significantly increase the accuracy and therefore the utility of the model for the decision making described above. This proposal addresses the Gulf of Mexico Alliance (GOMA) priority issue of reductions in nutrient inputs to coastal ecosystem. It further directly relates to water quality for healthy beaches and shellfish beds and wetland and coastal conservation

  13. Improved Hypoxia Modeling for Nutrient Control Decisions in the Gulf of Mexico

    NASA Technical Reports Server (NTRS)

    Habib, Shaid; Pickering, Ken; Tzortziou, Maria; Maninio, Antonio; Policelli, Fritz

    2010-01-01

    As required by the Harmful Algal Bloom and Hypoxia Research Control Act of 1998, the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force issued the 2001 Gulf Hypoxia Action Plan (updated in 2008). In response to the Gulf Hypoxia Action Plan of 2001 (updated in 2008), the EPA Gulf of Mexico Hypoxia Modeling and Monitoring Project has established a detailed model for the Mississippi-Attchafalaya River Basin which provides a capability to forecast the multi-source nutrient loading to the Gulf and the subsequent bio-geochemical processes leading to hypoxic conditions and subsequent effects on Gulf habitats and fisheries. The primary purpose of the EPA model is to characterize the impacts of nutrient management actions, or proposed actions on the spatial and temporal characteristics of the Gulf hypoxic zone. The model is expected to play a significant role in determining best practices and improved strategies for incentivizing nutrient reduction strategies, including installation of on-farm structures to reduce sediment and nutrient runoff, use of cover crops and other agricultural practices, restoration of wetlands and riparian buffers, improved waste water treatment and decreased industrial nitrogen emissions. These decisions are currently made in a fragmented way by federal, state, and local agencies, using a variety of small scale models and limited data. During the past three years, EPA has collected an enormous amount of in-situ data to be used in the model. We believe that the use of NASA satellite data products in the model and for long term validation of the model has the potential to significantly increase the accuracy and therefore the utility of the model for the decision making described above. This proposal addresses the Gulf of Mexico Alliance (GOMA) priority issue of reductions in nutrient inputs to coastal ecosystem. It further directly relates to water quality for healthy beaches and shellfish beds and wetland and coastal conservation

  14. Global dynamics in a stoichiometric food chain model with two limiting nutrients.

    PubMed

    Chen, Ming; Fan, Meng; Kuang, Yang

    2017-07-01

    Ecological stoichiometry studies the balance of energy and multiple chemical elements in ecological interactions to establish how the nutrient content affect food-web dynamics and nutrient cycling in ecosystems. In this study, we formulate a food chain with two limiting nutrients in the form of a stoichiometric population model. A comprehensive global analysis of the rich dynamics of the targeted model is explored both analytically and numerically. Chaotic dynamic is observed in this simple stoichiometric food chain model and is compared with traditional model without stoichiometry. The detailed comparison reveals that stoichiometry can reduce the parameter space for chaotic dynamics. Our findings also show that decreasing producer production efficiency may have only a small effect on the consumer growth but a more profound impact on the top predator growth. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Relationship of Consumption of Meals Including Grain, Fish and Meat, and Vegetable Dishes to the Prevention of Nutrient Deficiency: The INTERMAP Toyama Study.

    PubMed

    Koyama, Tatsuya; Yoshita, Katsushi; Sakurai, Masaru; Miura, Katsuyuki; Naruse, Yuchi; Okuda, Nagako; Okayama, Akira; Stamler, Jeremiah; Ueshima, Hirotsugu; Nakagawa, Hideaki

    2016-01-01

    A Japanese-style diet consists of meals that include grain (shushoku), fish and meat (shusai), and vegetable dishes (fukusai). Little is known about the association of such meals (designated well-balanced meals hereafter) with nutrient intake. We therefore examined the frequency of well-balanced meals required to prevent nutrient deficiency. Participants were Japanese people, ages 40 to 59 y, from Toyama, recruited for INTERMAP, in an international population-based study. Each person provided 4 in-depth 24-h dietary recalls (149 men, 150 women). The prevalence of risk ratios of not meeting the Dietary Reference Intakes for Japanese (2015) was calculated. Well-balanced diets were assessed by the Japanese Food Guide Spinning Top. We counted the frequencies of meals in which participants consumed 1.0 or more servings of all 3 dishes categories. We divided the frequency of consumption of well-balanced meals into the following 4 groups: <1.00 time/d, 1.00-1.49 times/d, 1.50-1.74 times/d, and ≥1.75 times/d. Compared with participants in the highest frequency group for well-balanced meals, those who consumed well-balanced meals less than once a day had a higher risk of not meeting the adequate intake for potassium and the recommended dietary allowance for vitamin A. Those who consumed well-balanced meals on average less than 1.50 times per day had a higher risk of not meeting the recommended dietary allowance for calcium and vitamin C. Our results suggest that individuals should on average consume well-balanced meals more than 1.5 times per day to prevent calcium and vitamin C deficiencies.

  16. Predicting sugar consumption: Application of an integrated dual-process, dual-phase model.

    PubMed

    Hagger, Martin S; Trost, Nadine; Keech, Jacob J; Chan, Derwin K C; Hamilton, Kyra

    2017-09-01

    Excess consumption of added dietary sugars is related to multiple metabolic problems and adverse health conditions. Identifying the modifiable social cognitive and motivational constructs that predict sugar consumption is important to inform behavioral interventions aimed at reducing sugar intake. We tested the efficacy of an integrated dual-process, dual-phase model derived from multiple theories to predict sugar consumption. Using a prospective design, university students (N = 90) completed initial measures of the reflective (autonomous and controlled motivation, intentions, attitudes, subjective norm, perceived behavioral control), impulsive (implicit attitudes), volitional (action and coping planning), and behavioral (past sugar consumption) components of the proposed model. Self-reported sugar consumption was measured two weeks later. A structural equation model revealed that intentions, implicit attitudes, and, indirectly, autonomous motivation to reduce sugar consumption had small, significant effects on sugar consumption. Attitudes, subjective norm, and, indirectly, autonomous motivation to reduce sugar consumption predicted intentions. There were no effects of the planning constructs. Model effects were independent of the effects of past sugar consumption. The model identified the relative contribution of reflective and impulsive components in predicting sugar consumption. Given the prominent role of the impulsive component, interventions that assist individuals in managing cues-to-action and behavioral monitoring are likely to be effective in regulating sugar consumption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. An empirical model for estimating annual consumption by freshwater fish populations

    USGS Publications Warehouse

    Liao, H.; Pierce, C.L.; Larscheid, J.G.

    2005-01-01

    Population consumption is an important process linking predator populations to their prey resources. Simple tools are needed to enable fisheries managers to estimate population consumption. We assembled 74 individual estimates of annual consumption by freshwater fish populations and their mean annual population size, 41 of which also included estimates of mean annual biomass. The data set included 14 freshwater fish species from 10 different bodies of water. From this data set we developed two simple linear regression models predicting annual population consumption. Log-transformed population size explained 94% of the variation in log-transformed annual population consumption. Log-transformed biomass explained 98% of the variation in log-transformed annual population consumption. We quantified the accuracy of our regressions and three alternative consumption models as the mean percent difference from observed (bioenergetics-derived) estimates in a test data set. Predictions from our population-size regression matched observed consumption estimates poorly (mean percent difference = 222%). Predictions from our biomass regression matched observed consumption reasonably well (mean percent difference = 24%). The biomass regression was superior to an alternative model, similar in complexity, and comparable to two alternative models that were more complex and difficult to apply. Our biomass regression model, log10(consumption) = 0.5442 + 0.9962??log10(biomass), will be a useful tool for fishery managers, enabling them to make reasonably accurate annual population consumption predictions from mean annual biomass estimates. ?? Copyright by the American Fisheries Society 2005.

  18. Short-Term Energy Outlook Model Documentation: Electricity Generation and Fuel Consumption Models

    EIA Publications

    2014-01-01

    The electricity generation and fuel consumption models of the Short-Term Energy Outlook (STEO) model provide forecasts of electricity generation from various types of energy sources and forecasts of the quantities of fossil fuels consumed for power generation. The structure of the electricity industry and the behavior of power generators varies between different areas of the United States. In order to capture these differences, the STEO electricity supply and fuel consumption models are designed to provide forecasts for the four primary Census regions.

  19. Short-Term Energy Outlook Model Documentation: Electricity Generation and Fuel Consumption Models

    EIA Publications

    2014-01-01

    The electricity generation and fuel consumption models of the Short-Term Energy Outlook (STEO) model provide forecasts of electricity generation from various types of energy sources and forecasts of the quantities of fossil fuels consumed for power generation. The structure of the electricity industry and the behavior of power generators varies between different areas of the United States. In order to capture these differences, the STEO electricity supply and fuel consumption models are designed to provide forecasts for the four primary Census regions.

  20. Wildland fire emissions, carbon, and climate: Modeling fuel consumption

    Treesearch

    Roger D. Ottmar

    2014-01-01

    Fuel consumption specifies the amount of vegetative biomass consumed during wildland fire. It is a two-stage process of pyrolysis and combustion that occurs simultaneously and at different rates depending on the characteristics and condition of the fuel, weather, topography, and in the case of prescribed fire, ignition rate and pattern. Fuel consumption is the basic...

  1. Modelling combined effects of nutrients and toxicants in a branch of the Rhine Delta

    SciTech Connect

    Kramer, P.R.G.; Nijs, A.C.M. de; Aldenberg, T.

    1995-12-31

    A model is presented in which fate and effects of both nutrients and toxicants are combined at the level of phytoplankton and zooplankton in a river system including its sedimentation area. Within water quality modelling emphasis has been on either eutrophication or on toxic fates. Eutrophication research mainly focuses on the relationship between nutrients and water quality parameters. Ecotoxicological studies on the other hand aim either at describing fate of toxic substances or estimating biological effects on or below organism level on the basis of dose-effect experiments. However, an integrated approach linking fate and effects of nutrients and toxic substances on the ecosystem level is demanded to understand the behavior of natural systems exposed to a mix of compounds. The model describes a branch of the river Rhine, the river IJssel, with its sedimentation areas, lake Ketelmeer and lake IJsselmeer, which have suffered severely from high inputs of both nutrients and heavy metals in the past. Only from the seventies onward international sanitation programs have significantly improved the situation. Despite the improvements further actions are required because the problems of high chlorophyll levels as well as high loading of metals remain. It is shown that nutrients may induce an increase in phytoplankton biomass due to less efficient zooplankton grazing. Model results show that in order to change the present state of eutrophication also the input of xenobiotic substances affecting the zooplankton must be decreased.

  2. Fruit and Vegetable Consumption in High School Students in Bandar Abbas, Iran: An Application of the Trans-theoretical Model.

    PubMed

    Davoodi, Sayed Hossein; Hosseini, Zahra; Aghamolaei, Teamur; Zare, Mehdi; Ghanbarnejad, Amin

    2017-06-01

    A diet rich in fruits and vegetables is of a great importance, especially to adolescents due to their need for nutrients and their rapid growth. The aim of this study was to investigate the relationship between decisional balance and self-efficacy with stages of change for fruit and vegetable consumption in high school students in Bandar Abbas, Iran. In this descriptive-analytical study, data were collected from 345 students studying in eight high schools of Bandar Abbas who were selected through multistage sampling. To collect data, separate questionnaires were designed for evaluating each of the variables, including the stages of change, perceived benefits, perceived barriers, and self-efficacy of fruit and vegetable consumption. Decisional balance was estimated by subtracting the perceived benefits and barriers. The data were analyzed with one-way ANOVA using SPSS 19. The results of this study indicated that the individuals' progress along the stages of change from pre-contemplation to maintenance level was associated with a significant increase in their decisional balance and self-efficacy for fruit and vegetable consumption (P < 0.001). The lowest level of decisional balance and self-efficacy regarding fruit showed up in the pre-contemplation stage, and the highest level of decisional balance and self-efficacy was in the maintenance stage. Similar trends were observed for vegetable consumption. Decisional balance and self-efficacy should be considered in designing interventions to increase consumption of fruits and vegetables. There needs to be more emphasis on educational programs based on the Trans-theoretical Model (TTM) for the enhancement of perceived benefits and elimination of perceived barriers regarding consumption of fruits and vegetables.

  3. Changes in consumption of food away from home and intakes of energy and other nutrients among US working-age adults, 2005-2014.

    PubMed

    Todd, Jessica E

    2017-09-07

    To document changes in consumption of food away from home (FAFH) and intakes of selected nutrients by working-age adults between 2005-06 and 2013-14, covering the most recent recessionary period and recovery. Means were compared across survey rounds relative to 2005-06. Multivariate regression was used to account for changes in demographic characteristics over time. National Health and Nutrition Examination Survey (NHANES), 2005-2014. Working-age adults born in 1951-80 (n 12 129) and adolescents and young adults born in 1981-90 (n 5197) who reported day 1 dietary intake data. Approximately 34 % of energy consumed by working-age adults came from FAFH (14 % from fast foods) in 2005-06. Levels of FAFH consumption were lowest in 2009-10, at 28 and 11 % of energy from FAFH and fast foods, respectively. Percentage of energy from fast foods was 1·9 percentage points higher in 2013-14. Percentage of energy from saturated fat and total mg of cholesterol consumed were lower in 2009-14, while intake of fibre was higher in 2011-14. At-home foods had less saturated fat and more fibre in 2009-14. The greater the percentage of energy from FAFH in the day, the greater the intakes of fat and cholesterol. Percentage of energy from FAFH was highest among those born in 1981-90 and lowest among those born in 1951-60. FAFH is a significant source of energy, fat and cholesterol among working-age adults. Menu labelling may lower FAFH's energy content and make it easier for consumers to choose more healthful items.

  4. Nutrient inputs to the Laurentian Great Lakes by source and watershed estimated using SPARROW watershed models

    USGS Publications Warehouse

    Robertson, Dale M.; Saad, David A.

    2011-01-01

    Nutrient input to the Laurentian Great Lakes continues to cause problems with eutrophication. To reduce the extent and severity of these problems, target nutrient loads were established and Total Maximum Daily Loads are being developed for many tributaries. Without detailed loading information it is difficult to determine if the targets are being met and how to prioritize rehabilitation efforts. To help address these issues, SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were developed for estimating loads and sources of phosphorus (P) and nitrogen (N) from the United States (U.S.) portion of the Great Lakes, Upper Mississippi, Ohio, and Red River Basins. Results indicated that recent U.S. loadings to Lakes Michigan and Ontario are similar to those in the 1980s, whereas loadings to Lakes Superior, Huron, and Erie decreased. Highest loads were from tributaries with the largest watersheds, whereas highest yields were from areas with intense agriculture and large point sources of nutrients. Tributaries were ranked based on their relative loads and yields to each lake. Input from agricultural areas was a significant source of nutrients, contributing ∼33-44% of the P and ∼33-58% of the N, except for areas around Superior with little agriculture. Point sources were also significant, contributing ∼14-44% of the P and 13-34% of the N. Watersheds around Lake Erie contributed nutrients at the highest rate (similar to intensively farmed areas in the Midwest) because they have the largest nutrient inputs and highest delivery ratio.

  5. Extinction and permanence of two-nutrient and two-microorganism chemostat model with pulsed input

    NASA Astrophysics Data System (ADS)

    Wang, Tieying; Chen, Lansun; Zhang, Ping

    2010-10-01

    In this paper, a model of the chemostat involving two species of microorganisms competing for two perfectly complementary, growth-limiting nutrients and periodically pulsed input is considered. By using the Floquet's theorem, we find the two-microorganism eradication periodic solution is globally asymptotically stable if R1 < 1 . At the same time we can find nutrients and microorganisms are permanent if R2 > 1 . Meanwhile, sufficient conditions based on biologically meaningful parameters in the model are given that predict competitive exclusion for certain parameter ranges and coexistence for others. Finally, our results are illustrated by numerical simulation.

  6. How to find information on national food and nutrient consumption surveys across Europe: systematic literature review and questionnaires to selected country experts are both good strategies.

    PubMed

    Blanquer, Maria; García-Alvarez, Alicia; Ribas-Barba, Lourdes; Wijnhoven, Trudy M A; Tabacchi, Garden; Gurinovic, Mirjana; Serra-Majem, Lluís

    2009-07-01

    The present research was conducted within the framework of the EURopean micronutrient RECommendations Aligned project. In order to identify the best practice in assessing nutrient intakes, a search strategy for collecting data from national food consumption surveys/studies in Europe was developed. Systematic literature searches were carried out on twenty-eight European and the four European Free Trade Association countries. A questionnaire was also sent to two to five experts in each country. Systematic reviews using PubMed yielded 12 703 abstracts that were reduced to 200 studies using inclusion and exclusion criteria. Similarly, a search of ministry web sites yielded 3033 hits, and subsequently reduced to nine surveys. Belgium, France, Germany, Ireland, Sweden, Spain and the United Kingdom were the countries with most data and Slovenia and Liechtenstein were those with the least. Seventy-eight expert questionnaires were obtained from all countries except for Liechtenstein, Luxembourg and Slovakia. Detailed results and references are given. A systematic search and questionnaires are equally good at identifying national surveys across countries. Literature searching provides globally accessible and objective information albeit limited, whereas the questionnaire provides information that, depending upon responders, can be more complete. A combination of both strategies is recommended.

  7. Bioclogging of dune sediments by coupled nutrient transport and microbial evolution: a numerical modeling study

    NASA Astrophysics Data System (ADS)

    Boano, Fulvio; Ridolfi, Luca; Packman, Aaron; Vidali, Cristina

    2014-05-01

    Streambeds are biogeochemical hotspots for a number of reactions that influence the fate of nutrients in streams and groundwater and that are performed by microorganisms attached to the hyporheic sediments. It is well known that in nutrient-enriched streams the metabolic activity of hyporheic microbes relies on water-borne solutes that are supplied by water exchanged with the stream. However, microbes also exert feedbacks on nutrient fluxes through the process of bioclogging, i.e., the reduction of water-filled pore volume and sediment permeability caused by biofilm growth and gas production. Unfortunately, the present understanding of this process is limited by the difficulty of data collection within streambed sediments. In order to better understand the dynamics of bioclogging, we have performed a numerical modeling study on the coupling between water fluxes, nutrient reactions, and permeability variations due to microbial growth. We have updated a previously published hydro-biogeochemical model with the addition of two microbial components representing autotrophic (nitrifying) bacteria and heterotrophic (facultative aerobic) bacteria. We assume that biofilm grows and occupies pore space, thus altering hydraulic conductivity and modifying the fluxes of water and nutrients which support microbial metabolism. The simulation results show that the system eventually attains an equilibrium between microbial growth and nutrient fluxes that is characterized by a vertical stratification of the microbial species and by a strong reduction of permeability near the stream-sediment interface. These findings denote the existence of an equilibrium configuration and provide insights on how microbial reaction rates are constrained by sediment properties, hydrodynamic factors, and nutrient availability.

  8. Hydrological management for improving nutrient assimilative capacity in plant-dominated wetlands: A modelling approach.

    PubMed

    Xu, Zhihao; Yang, Zhifeng; Yin, Xinan; Cai, Yanpeng; Sun, Tao

    2016-07-15

    Wetland eutrophication is a global environmental problem. Besides reducing pollutant emissions, improving nutrient assimilative capacity in wetlands is also significant for preventing eutrophication. Hydrological management can improve nutrient assimilative capacity in wetlands through physical effects on the dilution capacity of water body and ecological effects on wetland nutrient cycles. The ecological effects are significant while were rarely considered in previous research. This study focused on the ecological effects of hydrological management on two crucial nutrient removal processes, plant uptake and biological denitrification, in plant-dominated wetlands. A dual-objective optimization model for hydrological management was developed to improve wetland nitrogen and phosphorus assimilative capacities, using upstream reservoir release as water regulating measure. The model considered the interactions between ecological processes and hydrological cycles in wetlands, and their joint effects on nutrient assimilative capacity. Baiyangdian Wetland, the largest freshwater wetland in northern China, was chosen as a case study. The results found that the annual total assimilative capacity of nitrogen (phosphorus) was 4754 (493) t under the optimal scheme for upstream reservoir operation. The capacity of nutrient removal during the summer season accounted for over 80% of the annual total removal capacity. It was interesting to find that the relationship between water inflow and nutrient assimilative capacity in a plant-dominated wetland satisfied a dose-response relationship commonly describing the response of an organism to an external stressor in the medical field. It illustrates that a plant-dominated wetland shows similar characteristics to an organism. This study offers a useful tool and some fresh implications for future management of wetland eutrophication prevention. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Predictive modeling of transient storage and nutrient uptake: Implications for stream restoration

    USGS Publications Warehouse

    O'Connor, Ben L.; Hondzo, Miki; Harvey, Judson

    2010-01-01

    This study examined two key aspects of reactive transport modeling for stream restoration purposes: the accuracy of the nutrient spiraling and transient storage models for quantifying reach-scale nutrient uptake, and the ability to quantify transport parameters using measurements and scaling techniques in order to improve upon traditional conservative tracer fitting methods. Nitrate (NO3–) uptake rates inferred using the nutrient spiraling model underestimated the total NO3– mass loss by 82%, which was attributed to the exclusion of dispersion and transient storage. The transient storage model was more accurate with respect to the NO3– mass loss (±20%) and also demonstrated that uptake in the main channel was more significant than in storage zones. Conservative tracer fitting was unable to produce transport parameter estimates for a riffle-pool transition of the study reach, while forward modeling of solute transport using measured/scaled transport parameters matched conservative tracer breakthrough curves for all reaches. Additionally, solute exchange between the main channel and embayment surface storage zones was quantified using first-order theory. These results demonstrate that it is vital to account for transient storage in quantifying nutrient uptake, and the continued development of measurement/scaling techniques is needed for reactive transport modeling of streams with complex hydraulic and geomorphic conditions.

  10. 3D modeling of phytoplankton seasonal variation and nutrient budget in a southern Mediterranean Lagoon.

    PubMed

    Béjaoui, Béchir; Solidoro, Cosimo; Harzallah, Ali; Chevalier, Cristèle; Chapelle, Annie; Zaaboub, Noureddine; Aleya, Lotfi

    2017-01-30

    A 3D coupled physical-biogeochemical model is developed and applied to Bizerte Lagoon (Tunisia), in order to understand and quantitatively assess its hydrobiological functioning and nutrients budget. The biogeochemical module accounts for nitrogen and phosphorus and includes the water column and upper sediment layer. The simulations showed that water circulation and the seasonal patterns of nutrients, phytoplankton and dissolved oxygen were satisfactorily reproduced. Model results indicate that water circulation in the lagoon is driven mainly by tide and wind. Plankton primary production is co-limited by phosphorus and nitrogen, and is highest in the inner part of the lagoon, due to the combined effects of high water residence time and high nutrient inputs from the boundary. However, a sensitivity analysis highlights the importance of exchanges with the Mediterranean Sea in maintaining a high level of productivity. Intensive use of fertilizers in the catchment area has a significant effect on phytoplankton biomass increase. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. A Verhulst model for microalgae Botryococcus sp. growth and nutrient removal in wastewater

    NASA Astrophysics Data System (ADS)

    Jamaian, Siti Suhana; Bakeri, Noorhadila Mohd; Sunar, Norshuhaila Mohamed; Gani, Paran

    2017-08-01

    Microalgae Botryococcus sp. is a colonial green alga found in lakes and reservoirs in Malaysia. Previous studies reported that the potential of Botryococcus sp. photosynthesis as a source of fuel. The Botryococcus sp. contains hydrocarbon up to 75% of dry weight, which can be converted into petrol, diesel or turbine fuel or other liquid or gaseous hydrocarbons. Recently, an experimental study was conducted on phycoremediation technology for wastewater using Botryococcus sp. The phycoremediation technology is useful to remove the excess of nutrients such as nitrogen, phosphorus and also have the ability to remove various pollutants from wastewater. This research implements the Verhulst model to estimate the nutrient removal by microalgae Botryococcus sp. from the wastewater. This model has been validated with the experiments of microalgae Botryococcus sp. grown in domestic and palm oil wastewater. The results suggested that microalgae Botryococcus sp. could be cultured in domestic and palm oil wastewater while nutrients are reduced from these wastewaters.

  12. Use of hybrid discrete cellular models for identification of macroscopic nutrient loss in reaction-diffusion models of tissues.

    PubMed

    Aristotelous, Andreas C; Haider, Mansoor A

    2014-08-01

    Macroscopic models accounting for cellular effects in natural or engineered tissues may involve unknown constitutive terms that are highly dependent on interactions at the scale of individual cells. Hybrid discrete models, which represent cells individually, were used to develop and apply techniques for modeling diffusive nutrient transport and cellular uptake to identify a nonlinear nutrient loss term in a macroscopic reaction-diffusion model of the system. Flexible and robust numerical methods were used, based on discontinuous Galerkin finite elements in space and a Crank-Nicolson temporal discretization. Scales were bridged via averaging operations over a complete set of subdomains yielding data for identification of a macroscopic nutrient loss term that was accurately captured via a fifth-order polynomial. Accuracy of the identified macroscopic model was demonstrated by direct, quantitative comparisons of the tissue and cellular scale models in terms of three error norms computed on a mesoscale mesh.

  13. Watershed modeling and monitoring for assessing nutrient trading viability and increasing the adoption of nutrient management practices

    EPA Science Inventory

    Presentation for the American Water Works Association Water Sustainability Conference. The presentation highlights latest results from water quality trading research conducted by ORD using the East Fork Watershed in Southwestern Ohio as a case study. The watershed has a nutrient ...

  14. Watershed modeling and monitoring for assessing nutrient trading viability and increasing the adoption of nutrient management practices

    EPA Science Inventory

    Presentation for the American Water Works Association Water Sustainability Conference. The presentation highlights latest results from water quality trading research conducted by ORD using the East Fork Watershed in Southwestern Ohio as a case study. The watershed has a nutrient ...

  15. Budgeting of major nutrients and the mitigation options for nutrient mining in semi-arid tropical agro-ecosystem of Tamil Nadu, India using NUTMON model.

    PubMed

    Surendran, U; Rama Subramoniam, S; Raja, P; Kumar, V; Murugappan, V

    2016-04-01

    Mining of nutrients from soil is a major problem in developing countries causing soil degradation and threaten long-term food production. The present study attempts to apply NUTrient MONitoring (NUTMON) model for carrying out nutrient budgeting to assess the stocks and flows of nitrogen (N), phosphorus (P), and potassium (K) in defined geographical unit based on the inputs, viz., mineral fertilizers, manures, atmospheric deposition, and sedimentation, and outputs, viz., harvested crop produces, residues, leaching, denitrification, and erosion losses. The study area covers Coimbatore and Erode Districts, which are potential agricultural areas in western agro-ecological zone of Tamil Nadu, India. The calculated nutrient balances for both the districts at district scale, using NUTMON methodology, were negative for nitrogen (N -3.3 and -10.1 kg ha(-1)) and potassium (K -58.6 and -9.8 kg ha(-1)) and positive for phosphorus (P +14.5 and 20.5 kg ha(-1)). Soil nutrient pool has to adjust the negative balance of N and K; there will be an expected mining of nutrient from the soil reserve. A strategy was attempted for deriving the fertilizer recommendation using Decision Support System for Integrated Fertilizer Recommendation (DSSIFER) to offset the mining in selected farms. The results showed that when DSSIFER recommended fertilizers are applied to crops, the nutrient balance was positive. NUTMON-Toolbox with DSSIFER would serve the purpose on enhancing soil fertility, productivity, and sustainability. The management options to mitigate nutrient mining with an integrated system approach are also discussed.

  16. Spatially-explicit modelling of nutrient loading to the landscape in the Great Lakes Basin

    NASA Astrophysics Data System (ADS)

    Hamlin, Q. F.; Kendall, A. D.; Martin, S. L.; Whitenack, H. D.; Hyndman, D. W.

    2016-12-01

    Loading of nitrogen and phosphorus to the landscape has resulted in dangerous algal blooms, contaminated drinking water, and decreased biodiversity. Here, we developed a GIS model to estimate spatially explicit nutrient loading across the Great Lakes Basin. The model expands on previous work in the lower peninsula of Michigan by Luscz et al. (2015). Inputs to the model include point source loads to streams along with five non-point source landscape loads: atmospheric deposition, chemical agricultural fertilizer, chemical non-agricultural fertilizer, manure application, and septic tanks. Scaling up from Michigan to the eight U.S. states and two Canadian provinces in the Great Lakes Basin provided unique challenges. In the case of the septic tank inputs, we compiled a multistate database of drinking water wells for use in an automated Python script to delineate wastewater treatment plant service areas and to estimate placement of septic tanks appropriately within the landscape. Using a model with individual nutrient inputs showed that even within a single land use class, there is high variability in loading rates. This variability suggests that simply prescribing loading estimates based on land use class is insufficient. Modelling high resolution and source specific landscape nutrient loading will be valuable to target strategies to decrease excessive anthropogenic nutrient loading in the Great Lakes Basin.

  17. Calibration models for electromagnetic induction methods to assess nutrient accumulation beneath confined livestock areas.

    PubMed

    Cordeiro, Marcos R C; Ranjan, R Sri; Ferguson, Ian J

    2011-01-01

    Nutrient accumulation in soils beneath confined livestock areas is a potential source of groundwater contamination. Electromagnetic induction (EMI) has become a practical method to assess nutrient content, with multiple linear regression (MLR) as the statistical method often employed to translate EMI readings into nutrient content. The purpose of this research is to compare and contrast the performance of spatially referenced MLR models that include secondary, 'easy-to-acquire' predictor variables such as spatial coordinate locations, soil water content and elevation information with MLR models based solely on EMI readings. Six feedlot areas were surveyed with an EM38 conductivity meter and between 6 and 12 sites at each feedlot were sampled at five different depths. The electrical conductivity (EC(e)), nitrate (NO3-) and phosphate (PO4(3-)) concentrations were measured and used as response variables. Analyses were performed using two different approaches: the response variables in individual layers and response variables by combining the layers within the soil profile. The results of both MLR methods were comparable in most instances because the models preferentially incorporated predictors derived from EM38 readings. Differences between the models were more evident when predicting NO3- and PO4(3-), even though prediction of these two analytes by either method was generally poor. Combined profile analysis was more effective for defining nutrient build-up because by-layer analysis gave non-significant or poor models in many instances.

  18. Modelling long-term ecotoxicological effects on an algal population under dynamic nutrient stress.

    PubMed

    Bontje, D; Kooi, B W; Liebig, M; Kooijman, S A L M

    2009-07-01

    We study the effects of toxicants on the functioning of phototrophic unicellular organism (an algae) in a simple aquatic microcosm by applying a parameter-sparse model. The model allows us to study the interaction between ecological and toxicological effects. Nutrient stress and toxicant stress, together or alone, can cause extinction of the algal population. The modelled algae consume dissolved inorganic nitrogen (DIN) under surplus light and use it for growth and maintenance. Dead algal biomass is mineralized by bacterial activity, leading to nutrient recycling. The ecological model is coupled with a toxicity-module that describes the dependency of the algal growth and death rate on the toxicant concentration. Model parameter fitting is performed on experimental data from Liebig, M., Schmidt, G., Bontje, D., Kooi, B.W., Streck, G., Traunspurger, W., Knacker, T. [2008. Direct and indirect effects of pollutants on algae and algivorous ciliates in an aquatic indoor microcosm. Aquatic Toxicology 88, 102-110]. These experiments were especially designed to include nutrient limitation, nutrient recycling and long-term exposure to toxicants. The flagellate species Cryptomonas sp. was exposed to the herbicide prometryn and insecticide methyl parathion in semi-closed Erlenmeyers. Given the total limiting amount of nitrogen in the system, the estimated toxicant concentration at which a long-term steady population of algae goes extinct will be derived. We intend to use the results of this study to investigate the effects of ecological (environmental) and toxicological stresses on more realistic ecosystem structure and functioning.

  19. A simple model of variable residence time flow and nutrient transport in the chalk

    NASA Astrophysics Data System (ADS)

    Jackson, Bethanna M.; Wheater, Howard S.; Mathias, Simon A.; McIntyre, Neil; Butler, Adrian P.

    2006-10-01

    SummaryA basic problem of modelling flow and transport in Chalk catchments arises from the existence of a deep unsaturated zone, with complex interactions between flow in fractures and water held in the fine pores of the rock matrix. The response of the water table to major infiltration episodes is rapid (of the order of days). However, chemical signals are strongly damped, suggesting that this water is of varying age, with a corresponding mixed history of nutrient loading. Clearly this effect should be represented in any model of nutrients in Chalk systems. The applicability of simplified physically-based model formulations to represent the dual response in an integrated way has been investigated by a variety of researchers, but it has been shown that these approximations break down in application to the Chalk. Mathias et al. [Mathias, S., Butler, A.P., Jackson, B.M., Wheater, H.S., this issue. Characterising flow in the Chalk unsaturated zone. In: Wheater, H.S., Peach, D., Neal, C, editors, Hydrology on LOCAR in the Pang/Lambourn, special issue of J. Hydrol, doi:10.1016/j.jhydrol.2006.04.010] present a dual permeability model that explains the observed response, but such complex formulations are not readily incorporated in catchment-scale nutrient models. This paper reviews previous approaches to modelling the Chalk and then presents a pragmatic approach, with transport of solute and water through the unsaturated zone treated separately, and combined at the water table. Varying residence times are included through considering the distance between the water table and the soil surface, and the history of nutrient application at the surface. If an average rate of downwards migration of the nutrients is assumed, it is possible to derive a travel time distribution of nitrate transport to the water table using a DTM (digital terrain model) map of elevation and information on groundwater levels. This distribution can then be implemented through difference equations. The

  20. Food Expenditure and Nutrient Availability in Elderly Households.

    ERIC Educational Resources Information Center

    Hama, Mary Y.; Chern, Wen S.

    1988-01-01

    A model of food expenditure and nutrient consumption is developed and estimated using the data from the elderly supplemental survey to the 1977-78 USDA Nationwide Food Consumption Survey. Results provide strong evidence that elderly households make concurrent decisions on food budgets and nutritional needs. (Author)

  1. Food Expenditure and Nutrient Availability in Elderly Households.

    ERIC Educational Resources Information Center

    Hama, Mary Y.; Chern, Wen S.

    1988-01-01

    A model of food expenditure and nutrient consumption is developed and estimated using the data from the elderly supplemental survey to the 1977-78 USDA Nationwide Food Consumption Survey. Results provide strong evidence that elderly households make concurrent decisions on food budgets and nutritional needs. (Author)

  2. Improved Hypoxia Modeling for Nutrient Control Decisions in the Gulf of Mexico

    NASA Technical Reports Server (NTRS)

    Habib, Shahid; Pickering, Ken; Tzortziou, Maria; Maninio, Antonio; Policelli, Fritz; Stehr, Jeff

    2011-01-01

    The Gulf of Mexico Modeling Framework is a suite of coupled models linking the deposition and transport of sediment and nutrients to subsequent bio-geo chemical processes and the resulting effect on concentrations of dissolved oxygen in the coastal waters of Louisiana and Texas. Here, we examine the potential benefits of using multiple NASA remote sensing data products within this Modeling Framework for increasing the accuracy of the models and their utility for nutrient control decisions in the Gulf of Mexico. Our approach is divided into three components: evaluation and improvement of (a) the precipitation input data (b) atmospheric constituent concentrations in EPA's air quality/deposition model and (c) the calculation of algal biomass, organic carbon and suspended solids within the water quality/eutrophication models of the framework.

  3. Fuel consumption models for pine flatwoods fuel types in the southeastern United States

    Treesearch

    Clinton S. Wright

    2013-01-01

    Modeling fire effects, including terrestrial and atmospheric carbon fluxes and pollutant emissions during wildland fires, requires accurate predictions of fuel consumption. Empirical models were developed for predicting fuel consumption from fuel and environmental measurements on a series of operational prescribed fires in pine flatwoods ecosystems in the southeastern...

  4. Aquatic Nutrient Simulation Modules (NSMs) Developed for Hydrologic and Hydraulic Models

    DTIC Science & Technology

    2016-02-01

    standardizes many aspects of data entry, facilitates an efficient display of model results, data checking, data conversion, and communication ...Developed for Hydrologic and Hydraulic Models En vi ro nm en ta l L ab or at or y Zhonglong Zhang and Billy E. Johnson February 2016 DOC POC OrgP...EL TR-16-1 February 2016 Aquatic Nutrient Simulation Modules (NSMs) Developed for Hydrologic and Hydraulic Models Zhonglong Zhang and Billy E

  5. Inferring time-variable effects of nutrient enrichment on marine ecosystems using inverse modelling and ecological network analysis.

    PubMed

    Luong, Anh D; De Laender, Frederik; Olsen, Yngvar; Vadstein, Olav; Dewulf, Jo; Janssen, Colin R

    2014-09-15

    We combined data from an outdoor mesocosm experiment with carbon budget modelling and an ecological network analysis to assess the effects of continuous nutrient additions on the structural and functional dynamics of a marine planktonic ecosystem. The food web receiving no nutrient additions was fuelled by detritus, as zooplankton consumed 7.2 times more detritus than they consumed algae. Nutrient supply instantly promoted herbivory so that it was comparable to detritivory at the highest nutrient addition rate. Nutrient-induced food web restructuring reduced carbon cycling and decreased the average number of compartments a unit flow of carbon crosses before dissipation. Also, the efficiency of copepod production, the link to higher trophic levels harvestable by man, was lowered up to 35 times by nutrient addition, but showed signs of recovery after 9 to 11 days. The dependency of the food web on exogenous input was not changed by the nutrient additions. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Phenomenological model for predicting the catabolic potential of an arbitrary nutrient.

    PubMed

    Seaver, Samuel M D; Sales-Pardo, Marta; Guimerà, Roger; Amaral, Luís A Nunes

    2012-01-01

    The ability of microbial species to consume compounds found in the environment to generate commercially-valuable products has long been exploited by humanity. The untapped, staggering diversity of microbial organisms offers a wealth of potential resources for tackling medical, environmental, and energy challenges. Understanding microbial metabolism will be crucial to many of these potential applications. Thermodynamically-feasible metabolic reconstructions can be used, under some conditions, to predict the growth rate of certain microbes using constraint-based methods. While these reconstructions are powerful, they are still cumbersome to build and, because of the complexity of metabolic networks, it is hard for researchers to gain from these reconstructions an understanding of why a certain nutrient yields a given growth rate for a given microbe. Here, we present a simple model of biomass production that accurately reproduces the predictions of thermodynamically-feasible metabolic reconstructions. Our model makes use of only: i) a nutrient's structure and function, ii) the presence of a small number of enzymes in the organism, and iii) the carbon flow in pathways that catabolize nutrients. When applied to test organisms, our model allows us to predict whether a nutrient can be a carbon source with an accuracy of about 90% with respect to in silico experiments. In addition, our model provides excellent predictions of whether a medium will produce more or less growth than another (p<10(-6)) and good predictions of the actual value of the in silico biomass production.

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

    PubMed

    Zhou, Pei; Huang, Jinliang; Hong, Huasheng

    2018-01-01

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

  8. A Nested Nearshore Nutrient Model (N&Sup3;M) for Nearshore Condition Assessment and Management

    EPA Science Inventory

    Nearshore conditions drive phenomena like harmful algal blooms (HABs), and the nearshore and coastal margin are the parts of the Great Lakes most used by humans. To assess conditions, optimize monitoring, and evaluate management options, a model of nearshore nutrient transport an...

  9. Nutrient Dynamics In Flooded Wetlands. I: Model Development

    EPA Science Inventory

    Wetlands are rich ecosystems recognized for ameliorating floods, improving water quality and providing other ecosystem benefits. In this part of a two-paper sequel, we present a relatively detailed process-based model for nitrogen and phosphorus retention, cycling and removal in...

  10. Nutrient Dynamics In Flooded Wetlands. I: Model Development

    EPA Science Inventory

    Wetlands are rich ecosystems recognized for ameliorating floods, improving water quality and providing other ecosystem benefits. In this part of a two-paper sequel, we present a relatively detailed process-based model for nitrogen and phosphorus retention, cycling and removal in...

  11. Daily Consumption of Lipid-Based Nutrient Supplements Containing 250 μg Iodine Does Not Increase Urinary Iodine Concentrations in Pregnant and Postpartum Women in Bangladesh.

    PubMed

    Mridha, Malay K; Matias, Susana L; Paul, Rina Rani; Hussain, Sohrab; Khan, Md Showkat Ali; Siddiqui, Zakia; Ullah, Barkat; Sarker, Mostofa; Hossain, Mokbul; Young, Rebecca T; Arnold, Charles D; Dewey, Kathryn G

    2017-08-01

    Background: Maternal iodine deficiency during pregnancy and lactation is common in Bangladesh.Objective: We evaluated the effect of lipid-based nutrient supplements for pregnant and lactating women (LNS-PL) on urinary iodine concentration (UIC).Methods: We conducted a cluster-randomized controlled effectiveness trial in which we enrolled 4011 pregnant women at ≤20 gestational weeks. Women in 48 clusters received iron and folic acid (IFA; 60 mg Fe/d + 400 μg folic acid/d) and women in 16 clusters received LNS-PL (20 g/d, 118 kcal) containing 22 vitamins and minerals (including 250 μg I). We randomly selected a subsample of 1159 women for repeated urine sample collection, i.e., at enrollment, at 36 wk of gestation, and at 6 mo postpartum, for UIC analysis, a secondary outcome of the trial.Results: The geometric mean UIC at 36 wk of gestation and at 6 mo postpartum did not differ significantly between the IFA and LNS-PL groups. The median (quartile 1, quartile 3) UIC at 36 wk was 27.4 μg/L (16.9, 52.7 μg/L) in the IFA group and 30.2 μg/L (17.7, 56.6 μg/L) in the LNS-PL group; at 6 mo, these were 23.0 μg/L (10.0, 45.9 μg/L) in the IFA group and 22.2 μg/L (9.1, 50.4 μg/L) in the LNS-PL group.Conclusion: Daily consumption of LNS-PL containing 250 μg I did not increase the UICs of pregnant and lactating women in Bangladesh. Iodine from lipid-based nutrient supplements may have been stored in the thyroid gland or secreted in breast milk instead of being excreted in urine. Additional research that uses other biomarkers of iodine status is needed to determine how to meet the iodine requirements of pregnant and lactating women in Bangladesh and similar settings. This trial was registered at clinicaltrials.gov as NCT01715038. © 2017 American Society for Nutrition.

  12. Assessing the construct validity of five nutrient profiling systems using diet modeling with linear programming.

    PubMed

    Clerfeuille, E; Vieux, F; Lluch, A; Darmon, N; Rolf-Pedersen, N

    2013-09-01

    Nutrient profiling classifies individual food products according to their nutrient content. According to the WHO (World Health Organization), validation is a key step in the development of a nutrient profiling system. The aim was to assess the construct validity of five European nutrient profiling systems (Choices, Keyhole, (AFSSA), European Commission (EC) system and FoodProfiler). Construct validity was assessed for each of the five-selected nutrient profiling systems by testing whether healthy foods (that is, identified as eligible by the system) make healthy diets, and unhealthy foods (that is, non-eligible) make unhealthy diets, using diet modeling. The AFSSA, EC and FoodProfiler systems were identified as valid, but differences in their levels of permissiveness suggested some misclassified food products. The two other systems failed the construct validity assessment. Among these three systems, the EC system is the less demanding in terms of nutritional information, it would, therefore, be the easiest to implement for regulating nutrition and health claims in Europe.

  13. Computer simulation of two chemostat models for one nutrient resource.

    PubMed

    Chichurin, Alexander V; Shvychkina, Helena N

    2016-08-01

    We consider Michaelis-Menten chemostat dynamic models, describing the process of continuous cultivation of bacteria with one organic substrate and two types of microorganisms in a case where the Michaelis-Menten constants for the two competing species of microorganisms are equal. For such a system we obtain solutions with the finite initial conditions assuming only positive values. As it is shown the problem is reduced to the solution of the nonlinear differential equation of the first order. For some parametric relations the solutions of the differential system are found in the analytical form. Using numerical procedures we construct software modules that allow modeling the chemostat cultivation for the changing parameters and visualizing the dynamics of the development process for each microorganism. A comparative analysis of some numerical methods that are used to integrate the resulting nonlinear differential equation is given.

  14. Recovery of arctic tundra from thermal erosion disturbance is constrained by nutrient accumulation: a modeling analysis.

    PubMed

    Pearce, A R; Rastetter, E B; Kwiatkowski, B L; Bowden, W B; Mack, M C; Jiang, Y

    2015-07-01

    Abstract. We calibrated the Multiple Element Limitation (MEL) model to Alaskan arctic tundra to simulate recovery of thermal erosion features (TEFs) caused by permafrost thaw and mass wasting. TEFs could significantly alter regional carbon (C) and nutrient budgets because permafrost soils contain large stocks of soil organic matter (SOM) and TEFs are expected to become more frequent as the climate warms. We simulated recovery following TEF stabilization and did not address initial, short-term losses of C and nutrients during TEF formation. To capture the variability among and within TEFs, we modeled a range of post-stabilization conditions by varying the initial size of SOM stocks and nutrient supply rates. Simulations indicate that nitrogen (N) losses after the TEF stabilizes are small, but phosphorus (P) losses continue. Vegetation biomass recovered 90% of its undisturbed C, N, and P stocks in 100 years using nutrients mineralized from SOM. Because of low litter inputs but continued decomposition, younger SOM continued to be lost for 10 years after the TEF began to recover, but recovered to about 84% of its undisturbed amount in 100 years. The older recalcitrant SOM in mineral soil continued to be lost throughout the 100-year simulation. Simulations suggest that biomass recovery depended on the amount of SOM remaining after disturbance. Recovery was initially limited by the photosynthetic capacity of vegetation but became co-limited by N and P once a plant canopy developed. Biomass and SOM recovery was enhanced by increasing nutrient supplies, but the magnitude, source, and controls on these supplies are poorly understood. Faster mineralization of nutrients from SOM (e.g., by warming) enhanced vegetation recovery but delayed recovery of SOM. Taken together, these results suggest that although vegetation and surface SOM on TEFs recovered quickly (25 and 100 years, respectively), the recovery of deep, mineral soil SOM took centuries and represented a major

  15. Variations in Amazon forest productivity correlated with foliar nutrients and modelled rates of photosynthetic carbon supply.

    PubMed

    Mercado, Lina M; Patiño, Sandra; Domingues, Tomas F; Fyllas, Nikolaos M; Weedon, Graham P; Sitch, Stephen; Quesada, Carlos Alberto; Phillips, Oliver L; Aragão, Luiz E O C; Malhi, Yadvinder; Dolman, A J; Restrepo-Coupe, Natalia; Saleska, Scott R; Baker, Timothy R; Almeida, Samuel; Higuchi, Niro; Lloyd, Jon

    2011-11-27

    The rate of above-ground woody biomass production, W(P), in some western Amazon forests exceeds those in the east by a factor of 2 or more. Underlying causes may include climate, soil nutrient limitations and species composition. In this modelling paper, we explore the implications of allowing key nutrients such as N and P to constrain the photosynthesis of Amazon forests, and also we examine the relationship between modelled rates of photosynthesis and the observed gradients in W(P). We use a model with current understanding of the underpinning biochemical processes as affected by nutrient availability to assess: (i) the degree to which observed spatial variations in foliar [N] and [P] across Amazonia affect stand-level photosynthesis; and (ii) how these variations in forest photosynthetic carbon acquisition relate to the observed geographical patterns of stem growth across the Amazon Basin. We find nutrient availability to exert a strong effect on photosynthetic carbon gain across the Basin and to be a likely important contributor to the observed gradient in W(P). Phosphorus emerges as more important than nitrogen in accounting for the observed variations in productivity. Implications of these findings are discussed in the context of future tropical forests under a changing climate.

  16. Variations in Amazon forest productivity correlated with foliar nutrients and modelled rates of photosynthetic carbon supply

    PubMed Central

    Mercado, Lina M.; Patiño, Sandra; Domingues, Tomas F.; Fyllas, Nikolaos M.; Weedon, Graham P.; Sitch, Stephen; Quesada, Carlos Alberto; Phillips, Oliver L.; Aragão, Luiz E. O. C.; Malhi, Yadvinder; Dolman, A. J.; Restrepo-Coupe, Natalia; Saleska, Scott R.; Baker, Timothy R.; Almeida, Samuel; Higuchi, Niro; Lloyd, Jon

    2011-01-01

    The rate of above-ground woody biomass production, WP, in some western Amazon forests exceeds those in the east by a factor of 2 or more. Underlying causes may include climate, soil nutrient limitations and species composition. In this modelling paper, we explore the implications of allowing key nutrients such as N and P to constrain the photosynthesis of Amazon forests, and also we examine the relationship between modelled rates of photosynthesis and the observed gradients in WP. We use a model with current understanding of the underpinning biochemical processes as affected by nutrient availability to assess: (i) the degree to which observed spatial variations in foliar [N] and [P] across Amazonia affect stand-level photosynthesis; and (ii) how these variations in forest photosynthetic carbon acquisition relate to the observed geographical patterns of stem growth across the Amazon Basin. We find nutrient availability to exert a strong effect on photosynthetic carbon gain across the Basin and to be a likely important contributor to the observed gradient in WP. Phosphorus emerges as more important than nitrogen in accounting for the observed variations in productivity. Implications of these findings are discussed in the context of future tropical forests under a changing climate. PMID:22006971

  17. Short-Term Energy Outlook Model Documentation: Natural Gas Consumption and Prices

    EIA Publications

    2015-01-01

    The natural gas consumption and price modules of the Short-Term Energy Outlook (STEO) model are designed to provide consumption and end-use retail price forecasts for the residential, commercial, and industrial sectors in the nine Census districts and natural gas working inventories in three regions. Natural gas consumption shares and prices in each Census district are used to calculate an average U.S. retail price for each end-use sector.

  18. Short-Term Energy Outlook Model Documentation: Natural Gas Consumption and Prices

    EIA Publications

    2015-01-01

    The natural gas consumption and price modules of the Short-Term Energy Outlook (STEO) model are designed to provide consumption and end-use retail price forecasts for the residential, commercial, and industrial sectors in the nine Census districts and natural gas working inventories in three regions. Natural gas consumption shares and prices in each Census district are used to calculate an average U.S. retail price for each end-use sector.

  19. Modeling the fluid-dynamics and oxygen consumption in a porous scaffold stimulated by cyclic squeeze pressure.

    PubMed

    Ferroni, Marco; Giusti, Serena; Nascimento, Diana; Silva, Ana; Boschetti, Federica; Ahluwalia, Arti

    2016-08-01

    The architecture and dynamic physical environment of tissues can be recreated in-vitro by combining 3D porous scaffolds and bioreactors able to apply controlled mechanical stimuli on cells. In such systems, the entity of the stimuli and the distribution of nutrients within the engineered construct depend on the micro-structure of the scaffolds. In this work, we present a new approach for optimizing computational fluid-dynamics (CFD) models for the investigation of fluid-induced forces generated by cyclic squeeze pressure within a porous construct, coupled with oxygen consumption of cardiomyocytes. A 2D axial symmetric macro-scaled model of a squeeze pressure bioreactor chamber was used as starting point for generating time dependent pressure profiles. Subsequently the fluid movement generated by the pressure fields was coupled with a complete 3D micro-scaled model of a porous protein cryogel. Oxygen transport and consumption inside the scaffold was evaluated considering a homogeneous distribution of cardiomyocytes throughout the structure, as confirmed by preliminary cell culture experiments. The results show that a 3D description of the system, coupling a porous geometry and time dependent pressure driven flow with fluid-structure-interaction provides an accurate and meaningful description of the microenvironment in terms of shear stress and oxygen distribution than simple stationary 2D models. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  20. Modeling Tribal Exposures to PCBs from Fish Consumption

    EPA Science Inventory

    Studies have shown that U.S. population continues to be exposed to polychlorinated biphenyls (PCBs), despite the ban ~40 years ago. Fish intake is a major pathway, especially, for high fish-consumption groups. Exposure assessment and risk management considerations for tribal fish...

  1. Modeling Tribal Exposures to PCBs from Fish Consumption

    EPA Science Inventory

    Studies have shown that U.S. population continues to be exposed to polychlorinated biphenyls (PCBs), despite the ban ~40 years ago. Fish intake is a major pathway, especially, for high fish-consumption groups. Exposure assessment and risk management considerations for tribal fish...

  2. Modeling tribal exposures to methyl mercury from fish consumption

    EPA Science Inventory

    Exposure assessment and risk management considerations for tribal fish consumption are different than for the general U.S. population because of higher fish intake from subsistence fishing and/or from unique cultural practices. This research summarizes analyses of available data ...

  3. Modeling tribal exposures to methyl mercury from fish consumption

    EPA Science Inventory

    Exposure assessment and risk management considerations for tribal fish consumption are different than for the general U.S. population because of higher fish intake from subsistence fishing and/or from unique cultural practices. This research summarizes analyses of available data ...

  4. Springs as Model Systems for Aquatic Ecosystems Ecology: Stoichiometry, Metabolism and Nutrient Limitation

    NASA Astrophysics Data System (ADS)

    Cohen, M. J.; Nifong, R. L.; Kurz, M. J.; Martin, J. B.; Cropper, W. P.; Korhnak, L. V.

    2013-12-01

    and P gradients, they are more plastic in response to micronutrient variation, particularly for iron and manganese. Expanding on the Droop model framework for understanding nutrient assimilation and plant growth, we discuss these results in the context of nutrient limitation of benthic-dominated lotic systems. We conclude that these spring-fed model systems are N and P saturated, and discuss tools for predicting nutrient limitation and thus eutrophication in flowing waters.

  5. Determining Nutrient Requirements For Intensively Managed Loblolly Pine Stands Using the SSAND (Soil Supply and Nutrient Demand) Model

    Treesearch

    Hector G. Adegbidi; Nicholas B. Comerford; Hua Li; Eric J. Jokela; Nairam F. Barros

    2002-01-01

    Nutrient management represents a central component of intensive silvicultural systems that are designed to increase forest productivity in southern pine stands. Forest soils throughout the South are generally infertile, and fertilizers may be applied one or more times over the course of a rotation. Diagnostic techniques, such as foliar analysis and soil testing are...

  6. Biological Nutrient Removal Model No. 2 (BNRM2): a general model for wastewater treatment plants.

    PubMed

    Barat, R; Serralta, J; Ruano, M V; Jiménez, E; Ribes, J; Seco, A; Ferrer, J

    2013-01-01

    This paper presents the plant-wide model Biological Nutrient Removal Model No. 2 (BNRM2). Since nitrite was not considered in the BNRM1, and this previous model also failed to accurately simulate the anaerobic digestion because precipitation processes were not considered, an extension of BNRM1 has been developed. This extension comprises all the components and processes required to simulate nitrogen removal via nitrite and the formation of the solids most likely to precipitate in anaerobic digesters. The solids considered in BNRM2 are: struvite, amorphous calcium phosphate, hidroxyapatite, newberite, vivianite, strengite, variscite, and calcium carbonate. With regard to nitrogen removal via nitrite, apart from nitrite oxidizing bacteria two groups of ammonium oxidizing organisms (AOO) have been considered since different sets of kinetic parameters have been reported for the AOO present in activated sludge systems and SHARON (Single reactor system for High activity Ammonium Removal Over Nitrite) reactors. Due to the new processes considered, BNRM2 allows an accurate prediction of wastewater treatment plant performance in wider environmental and operating conditions.

  7. Residential electricity demand in Mexico: a model distinguishing access from consumption

    SciTech Connect

    Berndt, E.R.; Samaniego, R.

    1984-08-01

    Electricity access-consumption data of households by region and over time are the empirical basis for this paper. Following a brief background on residential electricity and energy consumption in Mexico, the authors discuss important demographic phenomena, the goals of electrification programs, and features of the electricity tariff schedules. They extend typical residential demand models to include separately the demand for electricity hook-ups. A principal finding is that a developing country like Mexico experiences a double whammy impact on electricity consumption with increases in income because of the demand for new hook-ups and the increased consumption by those who already have access. Policy implications are that pricing policy has a statistically significant impact on demand; that government-sponsored rural electrification programs have a major impact on consumption; and that the growth rates of consumption will level off as access becomes universal by 1990. 30 references 2 tables.

  8. Measurements and Modelling of Base Station Power Consumption under Real Traffic Loads †

    PubMed Central

    Lorincz, Josip; Garma, Tonko; Petrovic, Goran

    2012-01-01

    Base stations represent the main contributor to the energy consumption of a mobile cellular network. Since traffic load in mobile networks significantly varies during a working or weekend day, it is important to quantify the influence of these variations on the base station power consumption. Therefore, this paper investigates changes in the instantaneous power consumption of GSM (Global System for Mobile Communications) and UMTS (Universal Mobile Telecommunications System) base stations according to their respective traffic load. The real data in terms of the power consumption and traffic load have been obtained from continuous measurements performed on a fully operated base station site. Measurements show the existence of a direct relationship between base station traffic load and power consumption. According to this relationship, we develop a linear power consumption model for base stations of both technologies. This paper also gives an overview of the most important concepts which are being proposed to make cellular networks more energy-efficient. PMID:22666026

  9. Measurements and modelling of base station power consumption under real traffic loads.

    PubMed

    Lorincz, Josip; Garma, Tonko; Petrovic, Goran

    2012-01-01

    Base stations represent the main contributor to the energy consumption of a mobile cellular network. Since traffic load in mobile networks significantly varies during a working or weekend day, it is important to quantify the influence of these variations on the base station power consumption. Therefore, this paper investigates changes in the instantaneous power consumption of GSM (Global System for Mobile Communications) and UMTS (Universal Mobile Telecommunications System) base stations according to their respective traffic load. The real data in terms of the power consumption and traffic load have been obtained from continuous measurements performed on a fully operated base station site. Measurements show the existence of a direct relationship between base station traffic load and power consumption. According to this relationship, we develop a linear power consumption model for base stations of both technologies. This paper also gives an overview of the most important concepts which are being proposed to make cellular networks more energy-efficient.

  10. A model for gas and nutrient exchange in the chorionic vasculature system of the mouse placenta

    NASA Astrophysics Data System (ADS)

    Mirbod, Parisa; Sled, John

    2015-11-01

    The aim of this study is to develop an analytical model for the oxygen and nutrient transport from the umbilical cord to the small villous capillaries. The nutrient and carbon dioxide removal from the fetal cotyledons in the mouse placental system has also been considered. This model describes the mass transfer between the fetal and the maternal red blood cells in the chorionic arterial vasculature system. The model reveals the detail fetal vasculature system and its geometry and the precise mechanisms of mass transfer through the placenta. The dimensions of the villous capillaries, the total length of the villous trees, the total villi surface area, and the total resistance to mass transport in the fetal villous trees has also been defined. This is the first effort to explain the reason why there are at least 7 lobules in the mouse placenta from the fluid dynamics point of view.

  11. Estimating the carrying capacity of green mussel cultivation by using net nutrient removal model.

    PubMed

    Srisunont, Chayarat; Babel, Sandhya

    2016-11-15

    This study aims to evaluate the nutrient removal potential and carrying capacity of green mussel cultivation by using the mass balance model. The developed model takes into consideration the green mussel growth rate, density and chlorophyll a concentration. The data employed in this study were based on culture conditions at Sriracha Fisheries Research Station, Thailand. Results show that net nutrient removal by green mussel is 3302, 380, and 124mg/year/indv for carbon, nitrogen, and phosphorus respectively. The carrying capacity of green mussel cultivation was found to be 300indv/m(2) based on chlorophyll a concentration which will not release phosphorus in the water environment beyond the standard (45μg-PO4(-3)-P/L). Higher chlorophyll a concentration results in lowered green mussel carrying capacity. This model can assist farm operators with possible management strategies for a sustainable mussel cultivation and protection of the marine environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Social Modeling Influences and Alcohol Consumption during the First Semester of College: A Natural History Study

    ERIC Educational Resources Information Center

    Talbott, Laura L.; Moore, Charity G.; Usdan, Stuart L.

    2012-01-01

    The authors examine both the alcohol consumption pattern of freshmen students during their first semester and the degree to which social modeling of peer behavior impacts consumption. A total of 534 students, residing on campus, were prospectively examined at four 30-day intervals. Data were evaluated on the basis of age, gender, and the effects…

  13. Social Modeling Influences and Alcohol Consumption during the First Semester of College: A Natural History Study

    ERIC Educational Resources Information Center

    Talbott, Laura L.; Moore, Charity G.; Usdan, Stuart L.

    2012-01-01

    The authors examine both the alcohol consumption pattern of freshmen students during their first semester and the degree to which social modeling of peer behavior impacts consumption. A total of 534 students, residing on campus, were prospectively examined at four 30-day intervals. Data were evaluated on the basis of age, gender, and the effects…

  14. Two cytochrome oxygen consumption model and mechanism for carotid body chemoreception.

    PubMed

    Nair, P K; Buerk, D G; Whalen, W J; Schubert, R W

    1986-01-01

    We have measured sinus nerve discharge, tissue PO2 and oxygen consumption (VO2) in cat carotid bodies under different experimental conditions using our recessed oxygen microelectrode. Our results indicate that the change in chemoreceptor activity with oxygen disappearance following blood flow occlusion can be related to a two cytochrome model for oxygen consumption as previously proposed by Mills and Jöbsis (1972).

  15. Modeling, research and development of the system for optimal heat consumption of a building

    NASA Astrophysics Data System (ADS)

    Kovalnogov, Vladislav N.; Chamchiyan, Yuri E.; Suranov, Dmitry V.

    2016-06-01

    The work sets out the technical, software and organizational and methodological solutions for automated management and optimization of a building's heat consumption. It shows the results of modeling and research on the effectiveness of the automated system of heat consumption control of the main building of Ulyanovsk State Technical University.

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

    NASA Technical Reports Server (NTRS)

    Gregg, Watson W.; Rousseaux, Cecile S.

    2016-01-01

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

  17. Modeling spring-summer phytoplankton bloom in Lake Michigan with and without riverine nutrient loading

    NASA Astrophysics Data System (ADS)

    Luo, Lin; Wang, Jia; Hunter, Timothy; Wang, Dongxiao; Vanderploeg, Henry A.

    2017-09-01

    There were two phytoplankton blooms captured by remote sensing in Lake Michigan in 1998, one from March to May, and one during June. In this paper, those phytoplankton blooms were simulated by a coupled physical-biological model, driven by observed meteorological forcing in 1998. The model reasonably reproduced the lake currents. The biological model results, with and without riverine nutrient loading, were compared with the remote sensing data. A 3-month-long donut-like phytoplankton bloom that appeared in southern Lake Michigan was reasonably well simulated only when riverine input was included, indicating the importance of riverine nutrient input for supporting the growth of phytoplankton in Lake Michigan. The model with riverine input also captured a second event-driven phytoplankton bloom during June with weaker magnitude that occurred in mid-south Lake Michigan, which lasted for about 20 days. The major reason for the weaker bloom in June was that vertical mixing in the hydrodynamic model was too weak (leading to a mixed-layer depth of 20 m) to bring the bottom nutrient-rich water up to the epilimnion. High chlorophyll concentration that persisted in Green Bay for almost a year was simulated with less intensity.

  18. The Catchment Runoff Attenuation Flux Tool, a minimum information requirement nutrient pollution model

    NASA Astrophysics Data System (ADS)

    Adams, R.; Quinn, P. F.; Bowes, M. J.

    2015-04-01

    A model for simulating runoff pathways and water quality fluxes has been developed using the minimum information requirement (MIR) approach. The model, the Catchment Runoff Attenuation Flux Tool (CRAFT), is applicable to mesoscale catchments and focusses primarily on hydrological pathways that mobilise nutrients. Hence CRAFT can be used to investigate the impact of flow pathway management intervention strategies designed to reduce the loads of nutrients into receiving watercourses. The model can help policy makers meet water quality targets and consider methods to obtain "good" ecological status. A case study of the 414 km2 Frome catchment, Dorset, UK, has been described here as an application of CRAFT in order to highlight the above issues at the mesoscale. The model was primarily calibrated on 10-year records of weekly data to reproduce the observed flows and nutrient (nitrate nitrogen - N; phosphorus - P) concentrations. Data from 2 years with sub-daily monitoring at the same site were also analysed. These data highlighted some additional signals in the nutrient flux, particularly of soluble reactive phosphorus, which were not observable in the weekly data. This analysis has prompted the choice of using a daily time step as the minimum information requirement to simulate the processes observed at the mesoscale, including the impact of uncertainty. A management intervention scenario was also run to demonstrate how the model can support catchment managers investigating how reducing the concentrations of N and P in the various flow pathways. This mesoscale modelling tool can help policy makers consider a range of strategies to meet the European Union (EU) water quality targets for this type of catchment.

  19. Modeling the Relative Importance of Nutrient and Carbon Loads, Boundary Fluxes, and Sediment Fluxes on Gulf of Mexico Hypoxia.

    PubMed

    Feist, Timothy J; Pauer, James J; Melendez, Wilson; Lehrter, John C; DePetro, Phillip A; Rygwelski, Kenneth R; Ko, Dong S; Kreis, Russell G

    2016-08-16

    The Louisiana continental shelf in the northern Gulf of Mexico experiences bottom water hypoxia in the summer. In this study, we applied a biogeochemical model that simulates dissolved oxygen concentrations on the shelf in response to varying riverine nutrient and organic carbon loads, boundary fluxes, and sediment fluxes. Five-year model simulations demonstrated that midsummer hypoxic areas were most sensitive to riverine nutrient loads and sediment oxygen demand from settled organic carbon. Hypoxic area predictions were also sensitive to nutrient and organic carbon fluxes from lateral boundaries. The predicted hypoxic area decreased with decreases in nutrient loads, but the extent of change was influenced by the method used to estimate model boundary concentrations. We demonstrated that modeling efforts to predict changes in hypoxic area on the continental shelf in relationship to changes in nutrients should include representative boundary nutrient and organic carbon concentrations and functions for estimating sediment oxygen demand that are linked to settled organic carbon derived from water-column primary production. On the basis of our model analyses using the most representative boundary concentrations, nutrient loads would need to be reduced by 69% to achieve the Gulf of Mexico Nutrient Task Force Action Plan target hypoxic area of 5000 km(2).

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

    PubMed

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

    2012-12-01

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

  1. Modeling the Transport and Fate of Fecal Pollution and Nutrients of Miyun Reservoir

    NASA Astrophysics Data System (ADS)

    Liu, L.; Fu, X.; Wang, G.

    2009-12-01

    Miyun Reservoir, a mountain valley reservoir, is located 100 km northeast of Beijing City. Besides the functions of flood control, irrigation and fishery for Beijing area, Miyun Reservoir is the main drinking water storage for Beijing city. The water quality is therefore of great importance. Recently, the concentration of fecal pollution and nutrients in the reservoir are constantly rising to arrest the attention of Beijing municipality. Fecal pollution from sewage is a significant public health concern due to the known presence of human viruses and parasites in these discharges. To investigate the transport and fate of the fecal pollution and nutrients at Miyun reservoir and the health risks associated with drinking and fishery, the reservoir and two tributaries, Chaohe river and Baihe river discharging into it are being examined for bacterial, nutrients and other routine pollution. To understand the relative importance of different processes influencing pollution transport and inactivation, a finite-element model of surf-zone hydrodynamics (coupled with models for temperature, fecal pollution, nutrients and other routine contaminants) is used. The developed models are being verified by the observed water quality data including water temperature, conductivities and dissolved oxygen from the reservoir and its tributaries. Different factors impacting the inactivation of fecal pollution and the transport of nutrients such as water temperature, sedimentation, sunlight insolation are evaluated for Miyun reservoir by a sensitivity analysis analogized from the previous research of Lake Michigan (figure 1, indicating that solar insolation dominates the inactivation of E. Coli, an indicator of fecal pollution, Liu et al. 2006). The calibrated modeling system can be used to temporally and spatially simulate and predict the variation of the concentration of fecal pollution and nutrients of Miyun reservoir. Therefore this research can provide a forecasting tool for the

  2. Modelling nutrient retention in the coastal zone of an eutrophic sea

    NASA Astrophysics Data System (ADS)

    Almroth-Rosell, Elin; Edman, Moa; Eilola, Kari; Markus Meier, H. E.; Sahlberg, Jörgen

    2016-10-01

    The Swedish Coastal zone Model (SCM) was used at a test site, the Stockholm archipelago, located in the northern part of the central Baltic Sea, to study the retention capacity of the coastal filter on nitrogen (N) and phosphorus (P) loads from land and atmosphere. The efficiency of the coastal filter to permanently retain nutrients determines how much of the local nutrient loads actually reach the open sea. The SCM system is a nutrient-phytoplankton-zooplankton-detritus-type model coupled to a horizontally integrated, physical model in particular suitable for estuaries. In this study the Stockholm Archipelago, consisting of 86 sub-basins, was divided into three sub-areas: the inner, the intermediate and the outer archipelago. An evaluation of model results showed that the modelled freshwater supply agrees well with observations. The nutrient, salinity and temperature dynamics simulated by the SCM are also found to be in good or acceptable agreement with observations. The analysis showed that the Stockholm Archipelago works as a filter for nutrients that enter the coastal zone from land, but the filter efficiency is not effective enough to retain all the supplied nutrients. However, at least 65 and 72 % of the P and N, respectively, are retained during the studied period (1990-2012). A major part of the retention is permanent, which for P means burial. For N, almost 92 % of the permanent retention is represented by benthic denitrification, less than 8 % by burial, while pelagic denitrification is below 1 %. Highest total amounts of P and N are retained in the outer archipelago, where the surface area is largest. The area-specific retention of P and N, however, is highest in the smaller inner archipelago and decreases towards the open sea. A reduction scenario of the land loads of N and P showed that the filter efficiencies of N and P increase and the export of N from the archipelago decreases. About 15 years after the reduction, the export of P changes into an

  3. Computer model of hydroponics nutrient solution pH control using ammonium.

    PubMed

    Pitts, M; Stutte, G

    1999-01-01

    A computer simulation of a hydroponics-based plant growth chamber using ammonium to control pH was constructed to determine the feasibility of such a system. In nitrate-based recirculating hydroponics systems, the pH will increase as plants release hydroxide ions into the nutrient solution to maintain plant charge balance. Ammonium is an attractive alternative to traditional pH controls in an ALSS, but requires careful monitoring and control to avoid overdosing the plants with ammonium. The primary advantage of using NH4+ for pH control is that it exploits the existing plant nutrient uptake charge balance mechanisms to maintain solution pH. The simulation models growth, nitrogen uptake, and pH of a l-m2 stand of wheat. Simulation results indicated that ammonium-based control of nutrient solution pH is feasible using a proportional integral controller. Use of a 1 mmol/L buffer (Ka = 1.6 x 10(-6)) in the nutrient solution is required.

  4. Dynamic root growth and architecture responses to limiting nutrient availability: linking physiological models and experimentation.

    PubMed

    Postma, Johannes A; Schurr, Ulrich; Fiorani, Fabio

    2014-01-01

    In recent years the study of root phenotypic plasticity in response to sub-optimal environmental factors and the genetic control of these responses have received renewed attention. As a path to increased productivity, in particular for low fertility soils, several applied research projects worldwide target the improvement of crop root traits both in plant breeding and biotechnology contexts. To assist these tasks and address the challenge of optimizing root growth and architecture for enhanced mineral resource use, the development of realistic simulation models is of great importance. We review this research field from a modeling perspective focusing particularly on nutrient acquisition strategies for crop production on low nitrogen and low phosphorous soils. Soil heterogeneity and the dynamics of nutrient availability in the soil pose a challenging environment in which plants have to forage efficiently for nutrients in order to maintain their internal nutrient homeostasis throughout their life cycle. Mathematical models assist in understanding plant growth strategies and associated root phenes that have potential to be tested and introduced in physiological breeding programs. At the same time, we stress that it is necessary to carefully consider model assumptions and development from a whole plant-resource allocation perspective and to introduce or refine modules simulating explicitly root growth and architecture dynamics through ontogeny with reference to key factors that constrain root growth. In this view it is important to understand negative feedbacks such as plant-plant competition. We conclude by briefly touching on available and developing technologies for quantitative root phenotyping from lab to field, from quantification of partial root profiles in the field to 3D reconstruction of whole root systems. Finally, we discuss how these approaches can and should be tightly linked to modeling to explore the root phenome.

  5. A mechanistic soil biogeochemistry model with explicit representation of microbial and macrofaunal activities and nutrient cycles

    NASA Astrophysics Data System (ADS)

    Fatichi, Simone; Manzoni, Stefano; Or, Dani; Paschalis, Athanasios

    2016-04-01

    The potential of a given ecosystem to store and release carbon is inherently linked to soil biogeochemical processes. These processes are deeply connected to the water, energy, and vegetation dynamics above and belowground. Recently, it has been advocated that a mechanistic representation of soil biogeochemistry require: (i) partitioning of soil organic carbon (SOC) pools according to their functional role; (ii) an explicit representation of microbial dynamics; (iii) coupling of carbon and nutrient cycles. While some of these components have been introduced in specialized models, they have been rarely implemented in terrestrial biosphere models and tested in real cases. In this study, we combine a new soil biogeochemistry model with an existing model of land-surface hydrology and vegetation dynamics (T&C). Specifically the soil biogeochemistry component explicitly separates different litter pools and distinguishes SOC in particulate, dissolved and mineral associated fractions. Extracellular enzymes and microbial pools are explicitly represented differentiating the functional roles of bacteria, saprotrophic and mycorrhizal fungi. Microbial activity depends on temperature, soil moisture and litter or SOC stoichiometry. The activity of macrofauna is also modeled. Nutrient dynamics include the cycles of nitrogen, phosphorous and potassium. The model accounts for feedbacks between nutrient limitations and plant growth as well as for plant stoichiometric flexibility. In turn, litter input is a function of the simulated vegetation dynamics. Root exudation and export to mycorrhiza are computed based on a nutrient uptake cost function. The combined model is tested to reproduce respiration dynamics and nitrogen cycle in few sites where data were available to test plausibility of results across a range of different metrics. For instance in a Swiss grassland ecosystem, fine root, bacteria, fungal and macrofaunal respiration account for 40%, 23%, 33% and 4% of total belowground

  6. A dynamic CSTT model for the effects of added nutrients in Loch Creran, a shallow fjord

    NASA Astrophysics Data System (ADS)

    Laurent, Céline; Tett, Paul; Fernandes, Teresa; Gilpin, Linda; Jones, Ken

    2006-07-01

    Despite a tendency for the complexity of physical-biological models to increase, simple coupled models remain useful for some applications and can provide insights into crucial links between physical and biological processes. This argument is illustrated with an account of a simple 3-box model intended to help assess the capacity of fjords to assimilate nutrients from fish farms. The model, a dynamic version of the UK "Comprehensive Studies Task Team" (CSTT) steady-state model for eutrophication, was applied to Loch Creran (Scottish Western Highlands) and was implemented using Stella 8 and tested using historical data from 1975 (before the installation of a salmon farm) and field data collected in 2003, during the period of operation of the farm. The model's biological state variables are chlorophyll, dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP), and it includes a simple run-off model to convert rainfall into river discharge. The physical processes involved in exchange between the loch and the adjacent waters of the Firth of Lorne were parameterised as a constant daily exchange rate. Between 1975 and 2003, local inputs of nutrient increased but, despite this, there was little apparent increase in nutrient concentrations in the loch, and observed chlorophyll concentrations decreased substantially. Model simulations of chlorophyll and DIN agreed well with observations in 1975, as did DIN simulations in 2003. However, simulated chlorophyll was overestimated in 2003. Some of the agreement between observations and simulations come from the use of observed boundary conditions to force the model. However, even when boundary conditions are subtracted from simulations and observations, the simulations in most cases retain a significant correlation with observations, demonstrating that the model's 'interior' processes do add to its ability to replicate conditions in the loch.

  7. Evaluation of the current state of distributed watershed nutrient water quality modeling.

    PubMed

    Wellen, Christopher; Kamran-Disfani, Ahmad-Reza; Arhonditsis, George B

    2015-03-17

    Watershed models have been widely used for creating the scientific basis for management decisions regarding nonpoint source pollution. In this study, we evaluated the current state of watershed scale, spatially distributed, process-based, water quality modeling of nutrient pollution. Beginning from 1992, the year when Beven and Binley published their seminal paper on uncertainty analysis in hydrological modeling, and ending in 2010, we selected 257 scientific publications which (i) employed spatially distributed modeling approaches at a watershed scale; (ii) provided predictions of flow, nutrient/sediment concentrations or loads; and (iii) reported fit to measured data. Most "best practices" (optimization, validation, sensitivity, and uncertainty analysis) are not consistently employed during model development. There are no statistically significant differences in model performance among land uses. Studies which used more than one point in space to evaluate their distributed models had significantly lower median values of the Nash-Sutcliffe Efficiency (0.70 vs 0.56, p<0.005, nonparametric Mann-Whitney test), and r2 (p<0.005). This finding suggests that model calibration only to the basin outlet may mask compensation of positive and negative errors of source and transportation processes. We conclude by advocating a number of new directions for distributed watershed modeling, including in-depth uncertainty analysis and the use of additional information, not necessarily related to model end points, to constrain parameter estimation.

  8. Greenland Ice Sheet nutrient export: Towards a reaction-transport model of fjord dynamics

    NASA Astrophysics Data System (ADS)

    Crosby, James; Arndt, Sandra; Wadham, Jemma; Bingham, Rory

    2015-04-01

    Glacial runoff has the potential to deliver large quantities of dissolved and particulate bioavailable nutrients to surrounding marine environments. The marine waters bordering the Greenland Ice Sheet (GrIS) host some of the most productive ecosystems in the world, and possess high socio-economic value from fisheries. Furthermore, the productivity of phytoplankton in the North Atlantic sequesters CO2 from the atmosphere with a potentially important effect on the global coastal ocean CO2 budget. Providing a link between glacier and coastal ocean, fjords are critical components of the marine coastal system in this region, acting as both transfer routes and sinks for glacial nutrient export. As such they have the potential to act as significant biogeochemical processors, yet are currently underexplored. We propose to close this knowledge gap by developing a coupled 2D physical-biogeochemical model of the Godthåbsfjord system to quantitatively assess the impact of nutrients exported from the GrIS on fjord primary productivity and biogeochemical dynamics. Here, we present the first results of the hydrodynamic model. Hydrodynamic circulation patterns and freshwater transit times are explored to provide a first understanding of the glacier-fjord-ocean continuum. The hydrodynamic model will be dynamically coupled to a biogeochemical model with the view to providing a comprehensive understanding of the fate of nutrients exported from the GrIS. This will be extended to address the future sensitivity of these coastal systems to a warming climate, knowledge of which is critical when assessing the role of these dynamic and unique environments.

  9. Nonlinear regression modeling of nutrient loads in streams: A Bayesian approach

    USGS Publications Warehouse

    Qian, S.S.; Reckhow, K.H.; Zhai, J.; McMahon, G.

    2005-01-01

    A Bayesian nonlinear regression modeling method is introduced and compared with the least squares method for modeling nutrient loads in stream networks. The objective of the study is to better model spatial correlation in river basin hydrology and land use for improving the model as a forecasting tool. The Bayesian modeling approach is introduced in three steps, each with a more complicated model and data error structure. The approach is illustrated using a data set from three large river basins in eastern North Carolina. Results indicate that the Bayesian model better accounts for model and data uncertainties than does the conventional least squares approach. Applications of the Bayesian models for ambient water quality standards compliance and TMDL assessment are discussed. Copyright 2005 by the American Geophysical Union.

  10. Multi-nutrient, multi-group model of present and future oceanic phytoplankton communities

    NASA Astrophysics Data System (ADS)

    Litchman, E.; Klausmeier, C. A.; Miller, J. R.; Schofield, O. M.; Falkowski, P. G.

    2006-11-01

    Phytoplankton community composition profoundly affects patterns of nutrient cycling and the dynamics of marine food webs; therefore predicting present and future phytoplankton community structure is crucial to understand how ocean ecosystems respond to physical forcing and nutrient limitations. We develop a mechanistic model of phytoplankton communities that includes multiple taxonomic groups (diatoms, coccolithophores and prasinophytes), nutrients (nitrate, ammonium, phosphate, silicate and iron), light, and a generalist zooplankton grazer. Each taxonomic group was parameterized based on an extensive literature survey. We test the model at two contrasting sites in the modern ocean, the North Atlantic (North Atlantic Bloom Experiment, NABE) and subarctic North Pacific (ocean station Papa, OSP). The model successfully predicts general patterns of community composition and succession at both sites: In the North Atlantic, the model predicts a spring diatom bloom, followed by coccolithophore and prasinophyte blooms later in the season. In the North Pacific, the model reproduces the low chlorophyll community dominated by prasinophytes and coccolithophores, with low total biomass variability and high nutrient concentrations throughout the year. Sensitivity analysis revealed that the identity of the most sensitive parameters and the range of acceptable parameters differed between the two sites. We then use the model to predict community reorganization under different global change scenarios: a later onset and extended duration of stratification, with shallower mixed layer depths due to increased greenhouse gas concentrations; increase in deep water nitrogen; decrease in deep water phosphorus and increase or decrease in iron concentration. To estimate uncertainty in our predictions, we used a Monte Carlo sampling of the parameter space where future scenarios were run using parameter combinations that produced acceptable modern day outcomes and the robustness of the

  11. Finite element model for nutrient distribution analysis of a hollow fiber membrane bioreactor.

    PubMed

    Unnikrishnan, G U; Unnikrishnan, V U; Reddy, J N

    2012-02-01

    Hollow fiber membrane bioreactors (HFMB) are extensively used for the development of tissue substitutes for bones and cartilages. In an HFMB, the nutrient transport is dependent on the material properties of the porous scaffold and fiber membrane and also on the fluid flow through the hollow fiber. The difficulty in obtaining real-time data along with the presence of large number of variables in experimental studies have lead to increased application of computational models for the performance analysis of bioreactors. A major difficulty in the computational analysis of HFMB is the modeling of the interactions at the fluid and porous scaffold interfaces, which has often been neglected or incorporated using specific boundary conditions. In this study, a new FEM is developed to analyze the fluid flow in the fluid-porous region with the interface coupled directly into the FEM. Distribution of nutrients in the bioreactor is studied by coupling mass transport equations to the fluid-porous finite element framework. The new model is implemented to study the influence of permeability, cell density, and flow rate on the nutrient concentration distribution in the HFMB. The developed computational framework is an ideal tool to study fluid flow through porous-open channels and can also be used for the design of bioreactors for optimal tissue growth. Copyright © 2011 John Wiley & Sons, Ltd.

  12. Modelling of Scenedesmus obliquus; function of nutrients with modified Gompertz model.

    PubMed

    Celekli, Abuzer; Balci, Muharrem; Bozkurt, Hüseyin

    2008-12-01

    This study attempted to investigate variation in biovolume of Scenedesmus obliquus, in the modified Johnson medium at 20+/-2 degrees C, under 16kergcm(-2)s(-1) continuous illumination. The experiments were carried out at four nitrate (8, 12, 16, and 20mM) and four phosphate (0.1, 0.3, 0.5 and 0.7mM) concentrations at pH 7 and 8. The best response for algal growth was found at 0.3mM phosphate and 12mM nitrate at pH 7, as it was obtained from weight averaging method. Besides, optimum phosphate and nitrate concentrations significantly distinguished (p<0.01) from other concentrations according to Turkey's HSD test. Key features of the growth of S. obliquus under phosphate and nitrate influenced batch culture was successfully predicted by modified Gompertz model. Through the cultivations, specific growth rate (mu) ranged from 0.30 to 1.02 day(-1), while biovolume doubling time (td) varied from 0.68 to 2.30 days. There were important differences (p<0.05) for both mu and td among response variables. Both nutrients displayed noteworthy effect (p<0.01) on the algal biovolume.

  13. Modeling and optimization of the line-driver power consumption in xDSL systems

    NASA Astrophysics Data System (ADS)

    Wolkerstorfer, Martin; Trautmann, Steffen; Nordström, Tomas; Putra, Bakti D.

    2012-12-01

    Optimization of the power spectrum alleviates the crosstalk noise in digital subscriber lines (DSL) and thereby reduces their power consumption at present. In order to truly assess the DSL system power consumption, this article presents realistic line driver (LD) power consumption models. These are applicable to any DSL system and extend previous models by parameterizing various circuit-level non-idealities. Based on the model of a class-AB LD we analyze the multi-user power spectrum optimization problem and propose novel algorithms for its global or approximate solution. The thereby obtained simulation results support our claim that this problem can be simplified with negligible performance loss by neglecting the LD model. This motivates the usage of established spectral optimization algorithms, which are shown to significantly reduce the LD power consumption compared to static spectrum management.

  14. Modeling long-term changes in tundra carbon balance following wildfire, climate change, and potential nutrient addition.

    PubMed

    Jiang, Yueyang; Rastetter, Edward B; Shaver, Gaius R; Rocha, Adrian V; Zhuang, Qianlai; Kwiatkowski, Bonnie L

    2017-01-01

    To investigate the underlying mechanisms that control long-term recovery of tundra carbon (C) and nutrients after fire, we employed the Multiple Element Limitation (MEL) model to simulate 200-yr post-fire changes in the biogeochemistry of three sites along a burn severity gradient in response to increases in air temperature, CO2 concentration, nitrogen (N) deposition, and phosphorus (P) weathering rates. The simulations were conducted for severely burned, moderately burned, and unburned arctic tundra. Our simulations indicated that recovery of C balance after fire was mainly determined by the internal redistribution of nutrients among ecosystem components (controlled by air temperature), rather than the supply of nutrients from external sources (e.g., nitrogen deposition and fixation, phosphorus weathering). Increases in air temperature and atmospheric CO2 concentration resulted in (1) a net transfer of nutrient from soil organic matter to vegetation and (2) higher C : nutrient ratios in vegetation and soil organic matter. These changes led to gains in vegetation biomass C but net losses in soil organic C stocks. Under a warming climate, nutrients lost in wildfire were difficult to recover because the warming-induced acceleration in nutrient cycles caused further net nutrient loss from the system through leaching. In both burned and unburned tundra, the warming-caused acceleration in nutrient cycles and increases in ecosystem C stocks were eventually constrained by increases in soil C : nutrient ratios, which increased microbial retention of plant-available nutrients in the soil. Accelerated nutrient turnover, loss of C, and increasing soil temperatures will likely result in vegetation changes, which further regulate the long-term biogeochemical succession. Our analysis should help in the assessment of tundra C budgets and of the recovery of biogeochemical function following fire, which is in turn necessary for the maintenance of wildlife habitat and tundra

  15. Layered Plant-Growth Media for Optimizing Gaseous, Liquid and Nutrient Requirements: Modeling, Design and Monitoring

    NASA Astrophysics Data System (ADS)

    Heinse, R.; Jones, S. B.; Bingham, G.; Bugbee, B.

    2006-12-01

    Rigorous management of restricted root zones utilizing coarse-textured porous media greatly benefits from optimizing the gas-water balance within plant-growth media. Geophysical techniques can help to quantify root- zone parameters like water content, air-filled porosity, temperature and nutrient concentration to better address the root systems performance. The efficiency of plant growth amid high root densities and limited volumes is critically linked to maintaining a favorable water content/air-filled porosity balance while considering adequate fluxes to replenish water at decreasing hydraulic conductivities during uptake. Volumes adjacent to roots also need to be optimized to provide adequate nutrients throughout the plant's life cycle while avoiding excessive salt concentrations. Our objectives were to (1) design and model an optimized root zone system using optimized porous media layers, (2) verify our design by monitoring the water content distribution and tracking nutrient release and transport, and (3) mimic water and nutrient uptake using plants or wicks to draw water from the root system. We developed a unique root-zone system using layered Ottawa sands promoting vertically uniform water contents and air-filled porosities. Watering was achieved by maintaining a shallow saturated layer at the bottom of the column and allowing capillarity to draw water upward, where coarser particle sizes formed the bottom layers with finer particles sizes forming the layers above. The depth of each layer was designed to optimize water content based on measurements and modeling of the wetting water retention curves. Layer boundaries were chosen to retain saturation between 50 and 85 percent. The saturation distribution was verified by dual-probe heat-pulse water-content sensors. The nutrient experiment involved embedding slow release fertilizer in the porous media in order to detect variations in electrical resistivity versus time during the release, diffusion and uptake of

  16. Stable isotopes and Digital Elevation Models to study nutrient inputs in high-Arctic lakes

    NASA Astrophysics Data System (ADS)

    Calizza, Edoardo; Rossi, David; Costantini, Maria Letizia; Careddu, Giulio; Rossi, Loreto

    2016-04-01

    Ice cover, run-off from the watershed, aquatic and terrestrial primary productivity, guano deposition from birds are key factors controlling nutrient and organic matter inputs in high-Arctic lakes. All these factors are expected to be significantly affected by climate change. Quantifying these controls is a key baseline step to understand what combination of factors subtends the biological productivity in Arctic lakes and will drive their ecological response to environmental change. Basing on Digital Elevation Models, drainage maps, and C and N elemental content and stable isotope analysis in sediments, aquatic vegetation and a dominant macroinvertebrate species (Lepidurus arcticus Pallas 1973) belonging to Tvillingvatnet, Storvatnet and Kolhamna, three lakes located in North Spitsbergen (Svalbard), we propose an integrated approach for the analysis of (i) nutrient and organic matter inputs in lakes; (ii) the role of catchment hydro-geomorphology in determining inter-lake differences in the isotopic composition of sediments; (iii) effects of diverse nutrient inputs on the isotopic niche of Lepidurus arcticus. Given its high run-off and large catchment, organic deposits in Tvillingvatnet where dominated by terrestrial inputs, whereas inputs were mainly of aquatic origin in Storvatnet, a lowland lake with low potential run-off. In Kolhamna, organic deposits seem to be dominated by inputs from birds, which actually colonise the area. Isotopic signatures were similar between samples within each lake, representing precise tracers for studies on the effect of climate change on biogeochemical cycles in lakes. The isotopic niche of L. aricticus reflected differences in sediments between lakes, suggesting a bottom-up effect of hydro-geomorphology characterizing each lake on nutrients assimilated by this species. The presented approach proven to be an effective research pathway for the identification of factors subtending to nutrient and organic matter inputs and transfer

  17. Trans-Boundary Transport of Nutrients in the North Sea: a model study

    NASA Astrophysics Data System (ADS)

    van der Molen, Johan; Ruardij, Piet; van Leeuwen, Sonja M.; Coughlan, Clare; Mills, David K.

    2010-05-01

    Rivers are important sources of anthropogenic nutrients for shelf seas, originating from agriculture, sewage treatment plants and industry. After discharge into coastal and shelf seas, these nutrients are transported by marine currents, and can under certain conditions lead to eutrophication in certain maritime areas. The North Sea is surrounded by a number of highly industrialised countries, each of which contributes to the riverine nutrient load of specific rivers. In the Oslo-Paris convention (OSPAR), agreement was reached to reduce riverine nutrient loads to 50% of the levels in the year 1985 in areas where eutrophication has been diagnosed. As a contribution to the 2009 international workshop for the OSPAR Intersessional Correspondence Group for Eutrophication Modelling (ICG-EMO) in Brussels, model runs were carried out using the three-dimensional physical-biogeochemical model GETM-BFM to trace the contributions of Nitrogen from their source in prescribed groups of rivers to the maritime areas of the countries surrounding the North Sea, and to specific, smaller, target areas that are also used for eutrophication assessment. The model runs covered the period 1985 to 2002, where 1985-1996 were used for spin-up of the biogeochemistry, and 1997-2002 to track the Nitrogen discharged at the river mouths through the 3D physical space and through the biogeochemical cycles, including the sea bed. Results were analysed in terms of the contribution of the discharged Nitrogen from the specified groups of riverine sources to the total Nitrogen content within each grid cell of the model, and also within the specified maritime and target areas. The results showed that the dispersal of Nitrogen mainly followed the general circulation and known water masses in the North Sea. The result was an overlapping banded structure with Netherlands and German rivers contributing mainly to continental coastal waters, French rivers contributing to offshore waters and UK coastal waters

  18. Density outbursts in a food web model with a closed nutrient cycle

    NASA Astrophysics Data System (ADS)

    Szwabiński, Janusz

    2013-09-01

    A spatial three level food web model with a closed nutrient cycle is presented and analyzed via Monte Carlo simulations. The food web consists of three trophic levels. The basal level species (called resources, R) corresponds to primary producers in real ecosystems. The species at an intermediate level (consumers, C) relates to herbivores. It feeds on the resources. The consumers themselves constitute food for the top level species (predators, P), which corresponds to carnivores. The remains of the consumers and predators (detritus, D) provide nutrient for the resources. The time evolution of the model reveals two asymptotic states: an absorbing one with all species being extinct, and a coexisting one, in which concentrations of all species are non-zero. There are two possible ways for the system to reach the absorbing state. In some cases the densities increase very quickly at the beginning of a simulation and then decline slowly and almost monotonically. In others, well pronounced peaks in the R, C and D densities appear regularly before the extinction. Those peaks correspond to density outbursts (waves) traveling through the system. We investigate the mechanisms leading to the waves. In particular, we show that the percolation of the detritus (i.e. the accumulation of nutrients) is necessary for the emergence of the waves. Moreover, our results corroborate the hypothesis that top-level predators play an essential role in maintaining the stability of a food web (top-down control).

  19. Improving the Model for Energy Consumption Load Demand Forecasting

    NASA Astrophysics Data System (ADS)

    Bunnoon, Pituk; Chalermyanont, Kusumal; Limsakul, Chusak

    This paper proposes an application of a filter method in preprocessing stage for mid-term load demand forecasting to improve electricity load forecasting and to guarantee satisfactory forecasting accuracy. Case study employs the historical electricity consumption demand data in Thailand which were recorded in the 12 years of 1997 through to 2007. The load demand forecasted value is used for unit commitment and fuel reserve planning in the power system. This method consists of a trend component and a cyclical component decomposed from the original load demand using the Hodrick-Prescott (HP) filter in the preprocessing stage and the forecasting of each component using Double Neural Networks (DNNs) in the forecasting stage. Experimental results show that with preprocessing before forecasting can predict the load demand better than that without preprocessing.

  20. A Nested Nearshore Nutrient Model (N&Sup3;M) for ...

    EPA Pesticide Factsheets

    Nearshore conditions drive phenomena like harmful algal blooms (HABs), and the nearshore and coastal margin are the parts of the Great Lakes most used by humans. To assess conditions, optimize monitoring, and evaluate management options, a model of nearshore nutrient transport and algal dynamics is being developed. The model targets a “regional” spatial scale, similar to the Great Lakes Aquatic Habitat Framework's sub-basins, which divide the nearshore into 30 regions. Model runs are 365 days, a whole season temporal scale, reporting at 3 hour intervals. N³M uses output from existing hydrodynamic models and simple transport kinetics. The nutrient transport component of this model is largely complete, and is being tested with various hydrodynamic data sets. The first test case covers a 200 km² area between two major tributaries to Lake Michigan, the Grand and Muskegon. N³M currently simulates phosphorous and chloride, selected for their distinct in-lake transport dynamics; nitrogen will be added. Initial results for 2003, 2010, and 2015 show encouraging correlations with field measurements. Initially implemented in MatLab, the model is currently implemented in Python and leverages multi-processor computation. The 4D in-browser visualizer Cesium is used to view model output, time varying satellite imagery, and field observations. not applicable

  1. Modelling Macroalgae Productivity In An Estuary. A Biorremediation To Nutrient Discharges In The Ecosystems.

    NASA Astrophysics Data System (ADS)

    Alvera-Azcárate, A.; Ferreira, J. G.; Nunes, J. P.

    Enhanced nutrient load to estuaries and coastal waters due to anthropogenic activities is damaging aquatic ecosystems, resulting in water pollution and eutrophication prob- lems. It is important to quantify the production of photosynthetic organisms, as they play an important role in controlling nitrogen removal and nitrogen fluxes between the sediments and the water column. In turbid estuaries, such as those on the NE Atlantic coast of Europe, benthic primary producers such as macroalgae may play an important part in carbon fixation and nutrient removal, since pelagic production is often strongly light-limited. Estuarine seaweeds are primarily located in intertidal areas, which are characterised by shallow waters and strong tidal currents. Due to high concentrations of suspended particulate matter in the water column, light is rapidly attenuated, limiting macroal- gae production during part of the tidal cycle. An accurate representation of sediment dynamics is essential for the determination of the light energy available for the algae, which is a key factor in reliable primary production estimates. In tidal flats, the sedi- ment dynamics is made more complex by the formation of tidal pools during low tide, where water quickly becomes clear, allowing more light to penetrate through the water column. In the present work a model is developed to calculate macroalgae production in the intertidal areas of estuaries, considering the factors mentioned above. The model is tested for the Tagus estuary (Portugal), and a Gross Primary Production of 3300 g m-2 y-1 was obtained. That results in a total nitrogen removal of 440 gN m-2 y-1. The results show that the macroalgae community plays an impor- tant role in the nitrogen cycle in estuaries and nutrient export to the open sea, acting as a biorremediation for the increased nutrient loading problem.

  2. Watershed Modeling of Nutrient Transport Covering the Country of Sweden - Scale Transfer in HBV-NP

    NASA Astrophysics Data System (ADS)

    Arheimer, B.; Andersson, L.

    2002-12-01

    Eutrophication of the Baltic Sea and its coastal zone is considered a serious environmental problem. The problems are mainly caused by excessive load of nitrogen (N) and phosphorus (P). To improve the situation new policies including watershed-based water management are implemented. However, this also demands watershed-based knowledge of nutrient transport proc-esses and appropriate tools for landscape planning. A watershed model (HBV-NP) that can be applied both on the local and the national scale has thus been developed to be used both for international reporting and scenario estimates for more efficient nutrient control strategies. The P part is presently developed within the Swedish Water Management Research Program (VASTRA), in which HBV-NP will be used for evaluation of best management practices, and for communication with local stake-holders. The model has recently been applied at the national scale for calculations of flow-normalized annual average of gross load, N retention and net transport, and source apportionment of the N load reaching the sea. In this application (called TRK) several submodels with different levels of process descriptions were linked together. Dynamic and detailed models were included for arable leaching (SOIL-N model), rainfall interpolation, atmospheric deposition (MATCH model), water balance (HBV), and nutrient transformation in groundwater, rivers and lakes (HBV-N). Based on landscape information in GIS, different leaching rates and emissions were assigned to the water discharge from similar landscape elements in 1000 subbasins covering Sweden. Scale transfer was mainly achieved through up-scaling procedures and by using the conceptual model approach for watershed hydrology, including variability parameters that are calibrated for regions. The modeled river flow and N concentrations were validated against time-series from several independent-monitoring stations. A similar national system is now under development for P, including

  3. Comparative study of model prediction of diffuse nutrient losses in response to changes in agricultural practices.

    PubMed

    Vagstad, N; French, H K; Andersen, H E; Behrendt, H; Grizzetti, B; Groenendijk, P; Lo Porto, A; Reisser, H; Siderius, C; Stromquist, J; Hejzlar, J; Deelstra, J

    2009-03-01

    This article presents a comparative study of modelled changes in nutrient losses from two European catchments caused by modifications in agricultural practices. The purpose was not to compare the actual models used, but rather to assess the uncertainties a manager may be faced with after receiving decision support from consultants using different models. Seven modelling teams were given the same data about two catchments and their management characteristics and were asked to model the same changes in management practices using the model of their own choice. This can potentially cause accumulated 'errors' due to differences in the modelling teams' interpretation of relevant processes and definitions of boundary conditions (inputs). The study was carried out within the framework of the EUROHARP project, which aimed at harmonising procedures for quantifying diffuse losses of nitrogen and phosphorus from agriculture. Models are important for assessing river basin management plans (RBMPs) as required e.g. under the EC Water Framework Directive and Action Plans under the EC Nitrates Directive. This article illustrates some challenges with respect to interpreting such modelling results. The selected management scenarios include changes in fertiliser application levels, changes in livestock numbers and changes in land-use and crop rotation systems. Seven models were applied for the same scenarios in the Enza catchment in Italy and the Zelivka catchment in the Czech Republic. All models had been calibrated and validated with respect to historical data of climatic conditions, water quality and discharge measurements. The modelling results reveal a variation in predicted effects of the management scenarios, causing different conclusions with respect to choice of best management practice for reducing nutrient losses. The study demonstrates that it is important that care is taken by modellers and involved decision makers throughout the entire modelling process, both with regard

  4. Water and Nutrient Balances in a Large Tile-Drained Agricultural Catchment: A Distributed Modeling Study

    SciTech Connect

    Li, Hongyi; Sivapalan, Murugesu; Tian, Fuqiang; Liu, Dengfeng

    2010-11-16

    This paper presents the development and implementation of a distributed model of coupled water nutrient processes, based on the representative elementary watershed (REW) approach, to the Upper Sangamon River Basin, a large, tile-drained agricultural basin located in central Illinois, mid-west of USA. Comparison of model predictions with the observed hydrological and biogeochemical data, as well as regional estimates from literature studies, shows that the model is capable of capturing the dynamics of water, sediment and nutrient cycles reasonably well. The model is then used as a tool to gain insights into the physical and chemical processes underlying the inter- and intra-annual variability of water and nutrient balances. Model predictions show that about 80% of annual runoff is contributed by tile drainage, while the remainder comes from surface runoff (mainly saturation excess flow) and subsurface runoff. It is also found that, at the annual scale nitrogen storage in the soil is depleted during wet years, and is supplemented during dry years. This carryover of nitrogen storage from dry year to wet year is mainly caused by the lateral loading of nitrate. Phosphorus storage, on the other hand, is not affected much by wet/dry conditions simply because the leaching of it is very minor compared to the other mechanisms taking phosphorous out of the basin, such as crop harvest. The analysis then turned to the movement of nitrate with runoff. Model results suggested that nitrate loading from hillslope into the channel is preferentially carried by tile drainage. Once in the stream it is then subject to in-stream denitrification, the significant spatio-temporal variability of which can be related to the variation of the hydrologic and hydraulic conditions across the river network.

  5. Nutrients from dairy foods are difficult to replace in diets of Americans: food pattern modeling and an analyses of the National Health and Nutrition Examination Survey 2003-2006.

    PubMed

    Fulgoni, Victor L; Keast, Debra R; Auestad, Nancy; Quann, Erin E

    2011-10-01

    Because dairy products provide shortfall nutrients (eg, calcium, potassium, and vitamin D) and other important nutrients, this study hypothesized that it would be difficult for Americans to meet nutritional requirements for these nutrients in the absence of dairy product consumption or when recommended nondairy calcium sources are consumed. To test this hypothesis, MyPyramid dietary pattern modeling exercises and an analyses of data from the National Health and Nutrition Examination Survey 2003-2006 were conducted in those aged at least 2 years (n = 16 822). Impact of adding or removing 1 serving of dairy, removing all dairy, and replacing dairy with nondairy calcium sources was evaluated. Dietary pattern modeling indicated that at least 3 servings of dairy foods are needed to help individuals meet recommendations for nutrients, such as calcium and magnesium, and 4 servings may be needed to help some groups meet potassium recommendations. A calcium-equivalent serving of dairy requires 1.1 servings of fortified soy beverage, 0.6 serving of fortified orange juice, 1.2 servings of bony fish, or 2.2 servings of leafy greens. The replacement of dairy with calcium-equivalent foods alters the overall nutritional profile of the diet and affects nutrients including protein, potassium, magnesium, phosphorus, riboflavin, vitamins A, D and B(12). Similar modeling exercises using consumption data from the National Health and Nutrition Examination Survey also demonstrated that nondairy calcium replacement foods are not a nutritionally equivalent substitute for dairy products. In conclusion, although it is possible to meet calcium intake recommendations without consuming dairy foods, calcium replacement foods are not a nutritionally equivalent substitute for dairy foods and consumption of a calcium-equivalent amount of some nondairy foods is unrealistic. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Coupling hydrological and impact assessment models to explore nutrient cycling in freshwater systems

    NASA Astrophysics Data System (ADS)

    Bouwman, Lex; van Beek, Rens; Beusen, Arthur; Mogollón, José; Middelburg, Jack

    2016-04-01

    The IMAGE-Global Nutrient Model (GNM) is a new globally distributed, spatially explicit model in which the hydrology model PCR-GLOBWB is coupled to the integrated assessment model IMAGE to simulate nitrogen (N) and phosphorus (P) delivery, and then with a spiraling ecological approach to simulating instream biogeochemistry. Routing the water with dissolved and suspended N and P from upstream grid cells occurs simultaneous with N and P delivery to water bodies within grid cells from diffuse and point sources (wastewater). IMAGE-GNM describes the following diffuse sources associated with the water flow: surface runoff, shallow and deep groundwater, riparian zones. Depending on the landscape features, all these flows may be present within one grid cell. Furthermore, diffuse N and P inputs occur through allochtonous organic matter inputs via litterfall in (temporarily) inundated river floodplains, and atmospheric deposition. In the spiraling concept, the residence time of the water and nutrient uptake velocity determine N and P retention in water bodies. Validation of model results with observations yields acceptable agreement given the global scale of the uncalibrated model. Sensitivity analysis shows shifts in the importance of the different sources, with decreasing importance of natural sources and increasing influence of wastewater and agriculture. IMAGE-GNM can be employed to study the interaction between society and the environment over prolonged time periods. Here we show results for the full 20th century.

  7. Regional assessments of the Nation's water quality—Improved understanding of stream nutrient sources through enhanced modeling capabilities

    USGS Publications Warehouse

    Preston, Stephen D.; Alexander, Richard B.; Woodside, Michael D.

    2011-01-01

    The U.S. Geological Survey (USGS) recently completed assessments of stream nutrients in six major regions extending over much of the conterminous United States. SPARROW (SPAtially Referenced Regressions On Watershed attributes) models were developed for each region to explain spatial patterns in monitored stream nutrient loads in relation to human activities and natural resources and processes. The model information, reported by stream reach and catchment, provides contrasting views of the spatial patterns of nutrient source contributions, including those from urban (wastewater effluent and diffuse runoff from developed land), agricultural (farm fertilizers and animal manure), and specific background sources (atmospheric nitrogen deposition, soil phosphorus, forest nitrogen fixation, and channel erosion).

  8. The consequences of introducing stochasticity in nutrient utilisation models: the case of phosphorus utilisation by pigs.

    PubMed

    Symeou, V; Leinonen, I; Kyriazakis, I

    2016-02-14

    Simulation models of nutrient utilisation ignore that variation in pig system components can influence the predicted mean and variance of the performance of a group of pigs. The objective of this study was to develop a methodology to investigate how variation in feed composition would (a) affect the outputs of a nutrient utilisation model and (b) interact with variation that arises from the traits of individual pigs. We used a P intake and utilisation model to address these characteristics. Introduction of stochasticity gave rise to a number of methodological challenges--for example, how to generate variation in both feed composition and pigs and account for correlations between ingredients when modelling variation associated with feed mixing efficiency. Introducing variation in feed composition and pig phenotype resulted in moderate decreases in mean digested, retained and excreted P predicted for a population of pigs and an increase in their associated CV. A lower percentage of pigs in the population were predicted to meet their requirements during the feeding period considered, by comparison with the no-variation scenario. Variation in feed ingredient composition contributed more to performance variation than variation due to mixing efficiency. When variations in both feed composition and pig traits were considered, it was the former rather than the latter that had the dominant influence on variability in pig performance. The developed framework emphasises the consequences of random variability on the predictions of nutrient utilisation models. Such consequences will have a significant impact on decisions about management strategies such as feeding that are subject to variation.

  9. A Rat Drinking in the Dark Model for Studying Ethanol and Sucrose Consumption

    PubMed Central

    Holgate, Joan Y.; Shariff, Masroor; Mu, Erica W. H.; Bartlett, Selena

    2017-01-01

    Background: The intermittent access 2-bottle choice (IA2BC) and drinking in the dark (DID) models were developed for studying rodent binge-like consumption. Traditionally, IA2BC was used with rats and DID with mice. Recently, IA2BC was adapted to study mouse ethanol consumption. However, it is unknown whether DID is suitable for rats or if one rat model is more advantageous than another for studying binge-like consumption. Methods: Male Wistar rats consumed 20% ethanol or 5% sucrose using IA2BC or DID for 12 weeks. IA2BC drinking sessions occurred on alternate days (Mondays–Fridays) and lasted 24 h, whereas DID sessions ran 4 h/day, 5 days/week (Monday–Friday). Average consumption/session, week and hour was measured. To explore DID model suitability for screening novel compounds for controlling ethanol and sucrose intake, varenicline (2 mg/kg) or vehicle was administered to DID rats. Results: IA2BC rats consume more ethanol/session and similar amounts of ethanol/week than DID rats. While, IA2BC rats consume more sucrose/session and week than DID rats. Although IA2BC rats had more ethanol and sucrose access time, DID rats had greater ethanol and sucrose intake/hour. Varenicline significantly reduced ethanol and sucrose consumption in DID rats, consistent with previously published IA2BC studies. Conclusions: Despite the shorter access time, the rat DID model induced higher initial intake and greater consumption/hour for both ethanol and sucrose. The shorter duration of DID sessions did not prevent detection of varenicline-induced reductions in ethanol or sucrose consumption, suggesting the DID model may be suitable for studying binge-like ethanol and sucrose consumption. PMID:28275340

  10. Effects of signal light on the fuel consumption and emissions under car-following model

    NASA Astrophysics Data System (ADS)

    Tang, Tie-Qiao; Yi, Zhi-Yan; Lin, Qing-Feng

    2017-03-01

    In this paper, a car-following model is utilized to study the effects of signal light on each vehicle's fuel consumption, CO, HC and NOX. The numerical results show that each vehicle's fuel consumption and emissions are influenced by the signal light and that the effects are related to the green split of the signal light and the vehicle's time headway at the origin, which can help drivers adjust their micro driving behavior on the road with a signal light to reduce their fuel consumption and emissions.

  11. Water Quality Protection from Nutrient Pollution: Case ...

    EPA Pesticide Factsheets

    Water bodies and coastal areas around the world are threatened by increases in upstream sediment and nutrient loads, which influence drinking water sources, aquatic species, and other ecologic functions and services of streams, lakes, and coastal water bodies. For example, increased nutrient fluxes from the Mississippi River Basin have been linked to increased occurrences of seasonal hypoxia in northern Gulf of Mexico. Lake Erie is another example where in the summer of 2014 nutrients, nutrients, particularly phosphorus, washed from fertilized farms, cattle feedlots, and leaky septic systems; caused a severe algae bloom, much of it poisonous; and resulted in the loss of drinking water for a half-million residents. Our current management strategies for point and non-point source nutrient loadings need to be improved to protect and meet the expected increased future demands of water for consumption, recreation, and ecological integrity. This presentation introduces management practices being implemented and their effectiveness in reducing nutrient loss from agricultural fields, a case analysis of nutrient pollution of the Grand Lake St. Marys and possible remedies, and ongoing work on watershed modeling to improve our understanding on nutrient loss and water quality. Presented at the 3rd International Conference on Water Resource and Environment.

  12. Modeled sensitivity of Lake Michigan productivity and zooplankton to changing nutrient concentrations and quagga mussels

    NASA Astrophysics Data System (ADS)

    Pilcher, Darren J.; McKinley, Galen A.; Kralj, James; Bootsma, Harvey A.; Reavie, Euan D.

    2017-08-01

    The recent decline in Lake Michigan productivity is often attributed to filter feeding by invasive quagga mussels, but some studies also implicate reductions in lakewide nutrient concentrations. We use a 3-D coupled hydrodynamic-biogeochemical model to evaluate the effect of changing nutrient concentrations and quagga mussel filtering on phytoplankton production and phytoplankton and zooplankton biomass. Sensitivity experiments are used to assess the net effect of each change separately and in unison. Quagga mussels are found to have the greatest impact during periods of isothermal mixing, while nutrients have the greatest impact during thermal stratification. Quagga mussels also act to enhance spatial heterogeneity, particularly between nearshore-offshore regions. This effect produces a reversal in the gradient of nearshore-offshore productivity: from relatively greater nearshore productivity in the prequagga lake to relatively lesser nearshore productivity after quaggas. The combined impact of both processes drives substantial reductions in phytoplankton and zooplankton biomass, as well as significant modifications to the seasonality of surface water pCO2, particularly in nearshore regions where mussel grazing continues year-round. These results support growing concern that considerable losses of phytoplankton and zooplankton will yield concurrent losses at higher trophic levels. Comparisons to observed productivity suggest that both quagga mussel filtration and lower lakewide total phosphorus are necessary to accurately simulate recent changes in primary productivity in Lake Michigan.

  13. Identification of nutrient and physical seed trait QTL in the model legume Lotus japonicus.

    PubMed

    Klein, Melinda A; Grusak, Michael A

    2009-08-01

    Legume seeds have the potential to provide a significant portion of essential micronutrients to the human diet. To identify the genetic basis for seed nutrient density, quantitative trait locus (QTL) analysis was conducted with the Miyakojima MG-20 x Gifu B-129 recombinant inbred population from the model legume Lotus japonicus. This population was grown to seed under greenhouse conditions in 2006 and 2007. Phenotypic data were collected for seed calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), sulfur (S), and zinc (Zn) concentrations and content. Data for physical seed traits (average seed mass and seed-pod allocation values) were also collected. Based on these phenotypic data, QTL analyses identified 103 QTL linked to 55 different molecular markers. Transgressive segregation, identified within this recombinant inbred population for both seed nutrient and physical traits, suggests new allelic combinations are available for agronomic trait improvement. QTL co-localization was also seen, suggesting that common transport processes might contribute to seed nutrient loading. Identification of loci involved in seed mineral density can be an important first step in identifying the genetic factors and, consequently, the physiological processes involved in mineral distribution to developing seeds. Longer term research efforts will focus on facilitating agronomic breeding efforts through ortholog identification in related crop legumes.

  14. Nutrient limitation on terrestrial plant growth--modeling the interaction between nitrogen and phosphorus.

    PubMed

    Agren, Göran I; Wetterstedt, J Å Martin; Billberger, Magnus F K

    2012-06-01

    Growth of plants in terrestrial ecosystems is often limited by the availability of nitrogen (N) or phosphorous (P) Liebig's law of the minimum states that the nutrient in least supply relative to the plant's requirement will limit the plant's growth. An alternative to the law of the minimum is the multiple limitation hypothesis (MLH) which states that plants adjust their growth patterns such that they are limited by several resources simultaneously. We use a simple model of plant growth and nutrient uptake to explore the consequences for the plant's relative growth rate of letting plants invest differentially in N and P uptake. We find a smooth transition between limiting elements, in contrast to the strict transition in Liebig's law of the minimum. At N : P supply ratios where the two elements simultaneously limit growth, an increase in either of the nutrients will increase the growth rate because more resources can be allocated towards the limiting element, as suggested by the multiple limitation hypothesis. However, the further the supply ratio deviates from these supply rates, the more the plants will follow the law of the minimum. Liebig's law of the minimum will in many cases be a useful first-order approximation. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  15. Modeling carbon-nutrient interactions during the early recovery of tundra after fire.

    PubMed

    Jiang, Yueyang; Rastetter, Edward B; Rocha, Adrian V; Pearce, Andrea R; Kwiatkowski, Bonnie L; Shaver, Gaius R

    2015-09-01

    Fire frequency has dramatically increased in the tundra of northern Alaska, USA, which has major implications for the carbon budget of the region and the functioning of these ecosystems, which support important wildlife species. We investigated the postfire succession of plant and soil carbon (C), nitrogen (N), and phosphorus (P) fluxes and stocks along a burn severity gradient in the 2007 Anaktuvuk River fire scar in northern Alaska. Modeling results indicated that the early regrowth of postfire tundra vegetation was limited primarily by its canopy photosynthetic potential, rather than nutrient availability, because of the initially low leaf area and relatively high inorganic N and P concentrations in soil. Our simulations indicated that the postfire recovery of tundra vegetation was sustained predominantly by the uptake of residual inorganic N (i.e., in the remaining ash), and the redistribution of N and P from soil organic matter to vegetation. Although residual nutrients in ash were higher in the severe burn than the moderate burn, the moderate burn recovered faster because of the higher remaining biomass and consequent photosynthetic potential. Residual nutrients in ash allowed both burn sites to recover and exceed the unburned site in both aboveground biomass and production five years after the fire. The investigation of interactions among postfire C, N, and P cycles has contributed to a mechanistic understanding of the response of tundra ecosystems to fire disturbance. Our study provided insight on how the trajectory of recovery of tundra from wildfire is regulated during early succession.

  16. Application of the general model 'biological nutrient removal model no. 1' to upgrade two full-scale WWTPs.

    PubMed

    Ruano, M V; Serralta, J; Ribes, J; Garcia-Usach, F; Bouzas, A; Barat, R; Seco, A; Ferrer, J

    2012-01-01

    In this paper, two practical case studies for upgrading two wastewater treatment plants (WWTPs) using the general model BNRM 1 (Biological Nutrient Removal Model No. 1) are presented. In the first case study, the Tarragona WWTP was upgraded by reducing the phosphorus load to the anaerobic digester in order to minimize the precipitation problems. Phosphorus load reduction was accomplished by mixing the primary sludge and the secondary sludge and by elutriating the mixed sludge. In the second case study, the Alcantarilla WWTP, the nutrient removal was enhanced by maintaining a relatively low dissolved oxygen concentration in Stage A to maintain the acidogenic bacteria activity. The VFA produced in Stage A favour the denitrification process and biological phosphorus removal in Stage B. These case studies demonstrate the benefits of using the general model BNRMI to simulate settling processes and biological processes related to both anaerobic and aerobic bacteria in the same process unit.

  17. Testing woody fuel consumption models for application in Australian southern eucalypt forest fires

    Treesearch

    J.J. Hollis; S. Matthews; Roger Ottmar; S.J. Prichard; S. Slijepcevic; N.D. Burrows; B. Ward; K.G. Tolhurst; W.R. Anderson; J S. Gould

    2010-01-01

    Five models for the consumption of coarse woody debris or woody fuels with a diameter larger than 0.6 cm were assessed for application in Australian southern eucalypt forest fires including: CONSUME models for (1) activity fuels, (2) natural western woody and (3) natural southern woody fuels, (4) the BURNUP model and (5) the recommendation by the Australian National...

  18. Identifying 'unhealthy' food advertising on television: a case study applying the UK Nutrient Profile model.

    PubMed

    Jenkin, Gabrielle; Wilson, Nick; Hermanson, Nicole

    2009-05-01

    To evaluate the feasibility of the UK Nutrient Profile (NP) model for identifying 'unhealthy' food advertisements using a case study of New Zealand television advertisements. Four weeks of weekday television from 15.30 hours to 18.30 hours was videotaped from a state-owned (free-to-air) television channel popular with children. Food advertisements were identified and their nutritional information collected in accordance with the requirements of the NP model. Nutrient information was obtained from a variety of sources including food labels, company websites and a national nutritional database. From the 60 h sample of weekday afternoon television, there were 1893 advertisements, of which 483 were for food products or retailers. After applying the NP model, 66 % of these were classified as advertising high-fat, high-salt and high-sugar (HFSS) foods; 28 % were classified as advertising non-HFSS foods; and the remaining 2 % were unclassifiable. More than half (53 %) of the HFSS food advertisements were for 'mixed meal' items promoted by major fast-food franchises. The advertising of non-HFSS food was sparse, covering a narrow range of food groups, with no advertisements for fresh fruit or vegetables. Despite the NP model having some design limitations in classifying real-world televised food advertisements, it was easily applied to this sample and could clearly identify HFSS products. Policy makers who do not wish to completely restrict food advertising to children outright should consider using this NP model for regulating food advertising.

  19. A novel cost based model for energy consumption in cloud computing.

    PubMed

    Horri, A; Dastghaibyfard, Gh

    2015-01-01

    Cloud data centers consume enormous amounts of electrical energy. To support green cloud computing, providers also need to minimize cloud infrastructure energy consumption while conducting the QoS. In this study, for cloud environments an energy consumption model is proposed for time-shared policy in virtualization layer. The cost and energy usage of time-shared policy were modeled in the CloudSim simulator based upon the results obtained from the real system and then proposed model was evaluated by different scenarios. In the proposed model, the cache interference costs were considered. These costs were based upon the size of data. The proposed model was implemented in the CloudSim simulator and the related simulation results indicate that the energy consumption may be considerable and that it can vary with different parameters such as the quantum parameter, data size, and the number of VMs on a host. Measured results validate the model and demonstrate that there is a tradeoff between energy consumption and QoS in the cloud environment. Also, measured results validate the model and demonstrate that there is a tradeoff between energy consumption and QoS in the cloud environment.

  20. A Novel Cost Based Model for Energy Consumption in Cloud Computing

    PubMed Central

    Horri, A.; Dastghaibyfard, Gh.

    2015-01-01

    Cloud data centers consume enormous amounts of electrical energy. To support green cloud computing, providers also need to minimize cloud infrastructure energy consumption while conducting the QoS. In this study, for cloud environments an energy consumption model is proposed for time-shared policy in virtualization layer. The cost and energy usage of time-shared policy were modeled in the CloudSim simulator based upon the results obtained from the real system and then proposed model was evaluated by different scenarios. In the proposed model, the cache interference costs were considered. These costs were based upon the size of data. The proposed model was implemented in the CloudSim simulator and the related simulation results indicate that the energy consumption may be considerable and that it can vary with different parameters such as the quantum parameter, data size, and the number of VMs on a host. Measured results validate the model and demonstrate that there is a tradeoff between energy consumption and QoS in the cloud environment. Also, measured results validate the model and demonstrate that there is a tradeoff between energy consumption and QoS in the cloud environment. PMID:25705716

  1. Multiple soil nutrient competition between plants, microbes, and mineral surfaces: model development, parameterization, and example applications in several tropical forests

    DOE PAGES

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

    2016-01-18

    Soil is a complex system where biotic (e.g., plant roots, micro-organisms) and abiotic (e.g., mineral surfaces) consumers compete for resources necessary for life (e.g., nitrogen, phosphorus). This competition is ecologically significant, since it regulates the dynamics of soil nutrients and controls aboveground plant productivity. Here we develop, calibrate and test a nutrient competition model that accounts for multiple soil nutrients interacting with multiple biotic and abiotic consumers. As applied here for tropical forests, the Nutrient COMpetition model (N-COM) includes three primary soil nutrients (NH4+, NO3− and POx; representing the sum of PO43−, HPO42− and H2PO4−) and five potential competitors (plantmore » roots, decomposing microbes, nitrifiers, denitrifiers and mineral surfaces). The competition is formulated with a quasi-steady-state chemical equilibrium approximation to account for substrate (multiple substrates share one consumer) and consumer (multiple consumers compete for one substrate) effects. N-COM successfully reproduced observed soil heterotrophic respiration, N2O emissions, free phosphorus, sorbed phosphorus and NH4+ pools at a tropical forest site (Tapajos). The overall model uncertainty was moderately well constrained. Our sensitivity analysis revealed that soil nutrient competition was primarily regulated by consumer–substrate affinity rather than environmental factors such as soil temperature or soil moisture. Our results also imply that under strong nutrient limitation, relative competitiveness depends strongly on the competitor functional traits (affinity and nutrient carrier enzyme abundance). We then applied the N-COM model to analyze field nitrogen and phosphorus perturbation experiments in two tropical forest sites (in Hawaii and Puerto Rico) not used in model development or calibration. Under soil inorganic nitrogen and phosphorus elevated conditions, the model accurately replicated the experimentally observed

  2. Multiple soil nutrient competition between plants, microbes, and mineral surfaces: model development, parameterization, and example applications in several tropical forests

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

    Soil is a complex system where biotic (e.g., plant roots, micro-organisms) and abiotic (e.g., mineral surfaces) consumers compete for resources necessary for life (e.g., nitrogen, phosphorus). This competition is ecologically significant, since it regulates the dynamics of soil nutrients and controls aboveground plant productivity. Here we develop, calibrate and test a nutrient competition model that accounts for multiple soil nutrients interacting with multiple biotic and abiotic consumers. As applied here for tropical forests, the Nutrient COMpetition model (N-COM) includes three primary soil nutrients (NH4+, NO3- and POx; representing the sum of PO43-, HPO42- and H2PO4-) and five potential competitors (plant roots, decomposing microbes, nitrifiers, denitrifiers and mineral surfaces). The competition is formulated with a quasi-steady-state chemical equilibrium approximation to account for substrate (multiple substrates share one consumer) and consumer (multiple consumers compete for one substrate) effects. N-COM successfully reproduced observed soil heterotrophic respiration, N2O emissions, free phosphorus, sorbed phosphorus and NH4+ pools at a tropical forest site (Tapajos). The overall model uncertainty was moderately well constrained. Our sensitivity analysis revealed that soil nutrient competition was primarily regulated by consumer-substrate affinity rather than environmental factors such as soil temperature or soil moisture. Our results also imply that under strong nutrient limitation, relative competitiveness depends strongly on the competitor functional traits (affinity and nutrient carrier enzyme abundance). We then applied the N-COM model to analyze field nitrogen and phosphorus perturbation experiments in two tropical forest sites (in Hawaii and Puerto Rico) not used in model development or calibration. Under soil inorganic nitrogen and phosphorus elevated conditions, the model accurately

  3. Avocado consumption is associated with better diet quality and nutrient intake, and lower metabolic syndrome risk in US adults: results from the National Health and Nutrition Examination Survey (NHANES) 2001-2008.

    PubMed

    Fulgoni, Victor L; Dreher, Mark; Davenport, Adrienne J

    2013-01-02

    Avocados contain monounsaturated fatty acids (MUFA) dietary fiber, essential nutrients and phytochemicals. However, no epidemiologic data exist on their effects on diet quality, weight management and other metabolic disease risk factors. The objective of this research was to investigate the relationships between avocado consumption and overall diet quality, energy and nutrient intakes, physiological indicators of health, and risk of metabolic syndrome. Avocado consumption and nutrition data were based on 24-hour dietary recalls collected by trained NHANES interviewers using the USDA Automated Multiple Pass Method (AMPM). Physiological data were collected from physical examinations conducted in NHANES Mobile Examination Centers. Diet quality was calculated using the USDA's Healthy Eating Index-2005. Subjects included 17,567 US adults ≥ 19 years of age (49% female), including 347 avocado consumers (50% female), examined in NHANES 2001-2008. Least square means, standard errors, and ANOVA were determined using appropriate sample weights, with adjustments for age, gender, ethnicity, and other covariates depending on dependent variable of interest. Avocado consumers had significantly higher intakes of vegetables (p<0.05); fruit, diet quality, total fat, monounsaturated and polyunsaturated fats, dietary fiber, vitamins E, K, magnesium, and potassium (p<0.0001); vitamin K (p=0.0013); and lower intakes of added sugars (p<0.0001). No significant differences were seen in calorie or sodium intakes. Body weight, BMI, and waist circumference were significantly lower (p<0.01), and HDL-C was higher (p<0.01) in avocado consumers. The odds ratio for metabolic syndrome was 50% (95th CI: 0.32-0.72) lower in avocado consumers vs. non-consumers. Avocado consumption is associated with improved overall diet quality, nutrient intake, and reduced risk of metabolic syndrome. Dietitians should be aware of the beneficial associations between avocado intake, diet and health when making

  4. Avocado consumption is associated with better diet quality and nutrient intake, and lower metabolic syndrome risk in US adults: results from the National Health and Nutrition Examination Survey (NHANES) 2001–2008

    PubMed Central

    2013-01-01

    Background Avocados contain monounsaturated fatty acids (MUFA) dietary fiber, essential nutrients and phytochemicals. However, no epidemiologic data exist on their effects on diet quality, weight management and other metabolic disease risk factors. The objective of this research was to investigate the relationships between avocado consumption and overall diet quality, energy and nutrient intakes, physiological indicators of health, and risk of metabolic syndrome. Methods Avocado consumption and nutrition data were based on 24-hour dietary recalls collected by trained NHANES interviewers using the USDA Automated Multiple Pass Method (AMPM). Physiological data were collected from physical examinations conducted in NHANES Mobile Examination Centers. Diet quality was calculated using the USDA’s Healthy Eating Index-2005. Subjects included 17,567 US adults  ≥ 19 years of age (49% female), including 347 avocado consumers (50% female), examined in NHANES 2001–2008. Least square means, standard errors, and ANOVA were determined using appropriate sample weights, with adjustments for age, gender, ethnicity, and other covariates depending on dependent variable of interest. Results Avocado consumers had significantly higher intakes of vegetables (p < 0.05); fruit, diet quality, total fat, monounsaturated and polyunsaturated fats, dietary fiber, vitamins E, K, magnesium, and potassium (p < 0.0001); vitamin K (p = 0.0013); and lower intakes of added sugars (p < 0.0001). No significant differences were seen in calorie or sodium intakes. Body weight, BMI, and waist circumference were significantly lower (p < 0.01), and HDL-C was higher (p < 0.01) in avocado consumers. The odds ratio for metabolic syndrome was 50% (95th CI: 0.32-0.72) lower in avocado consumers vs. non-consumers. Conclusions Avocado consumption is associated with improved overall diet quality, nutrient intake, and reduced risk of metabolic syndrome. Dietitians should be aware of

  5. Image-based modelling of nutrient movement in and around the rhizosphere

    PubMed Central

    Daly, Keith R.; Keyes, Samuel D.; Masum, Shakil; Roose, Tiina

    2016-01-01

    In this study, we developed a spatially explicit model for nutrient uptake by root hairs based on X-ray computed tomography images of the rhizosphere soil structure. This work extends our previous work to larger domains and hence is valid for longer times. Unlike the model used previously, which considered only a small region of soil about the root, we considered an effectively infinite volume of bulk soil about the rhizosphere. We asked the question: At what distance away from root surfaces do the specific structural features of root-hair and soil aggregate morphology not matter because average properties start dominating the nutrient transport? The resulting model was used to capture bulk and rhizosphere soil properties by considering representative volumes of soil far from the root and adjacent to the root, respectively. By increasing the size of the volumes that we considered, the diffusive impedance of the bulk soil and root uptake were seen to converge. We did this for two different values of water content. We found that the size of region for which the nutrient uptake properties converged to a fixed value was dependent on the water saturation. In the fully saturated case, the region of soil we needed to consider was only of radius 1.1mm for poorly soil-mobile species such as phosphate. However, in the case of a partially saturated medium (relative saturation 0.3), we found that a radius of 1.4mm was necessary. This suggests that, in addition to the geometrical properties of the rhizosphere, there is an additional effect of soil moisture properties, which extends further from the root and may relate to other chemical changes in the rhizosphere. The latter were not explicitly included in our model. PMID:26739861

  6. Image-based modelling of nutrient movement in and around the rhizosphere.

    PubMed

    Daly, Keith R; Keyes, Samuel D; Masum, Shakil; Roose, Tiina

    2016-02-01

    In this study, we developed a spatially explicit model for nutrient uptake by root hairs based on X-ray computed tomography images of the rhizosphere soil structure. This work extends our previous work to larger domains and hence is valid for longer times. Unlike the model used previously, which considered only a small region of soil about the root, we considered an effectively infinite volume of bulk soil about the rhizosphere. We asked the question: At what distance away from root surfaces do the specific structural features of root-hair and soil aggregate morphology not matter because average properties start dominating the nutrient transport? The resulting model was used to capture bulk and rhizosphere soil properties by considering representative volumes of soil far from the root and adjacent to the root, respectively. By increasing the size of the volumes that we considered, the diffusive impedance of the bulk soil and root uptake were seen to converge. We did this for two different values of water content. We found that the size of region for which the nutrient uptake properties converged to a fixed value was dependent on the water saturation. In the fully saturated case, the region of soil we needed to consider was only of radius 1.1mm for poorly soil-mobile species such as phosphate. However, in the case of a partially saturated medium (relative saturation 0.3), we found that a radius of 1.4mm was necessary. This suggests that, in addition to the geometrical properties of the rhizosphere, there is an additional effect of soil moisture properties, which extends further from the root and may relate to other chemical changes in the rhizosphere. The latter were not explicitly included in our model. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  7. Global patterns of phytoplankton nutrient and light colimitation inferred from an optimality-based model

    NASA Astrophysics Data System (ADS)

    Arteaga, Lionel; Pahlow, Markus; Oschlies, Andreas

    2014-07-01

    The widely used concept of constant "Redfield" phytoplankton stoichiometry is often applied for estimating which nutrient limits phytoplankton growth in the surface ocean. Culture experiments, in contrast, show strong relations between growth conditions and cellular stoichiometry with often substantial deviations from Redfield stoichiometry. Here we investigate to what extent both views agree by analyzing remote sensing and in situ data with an optimality-based model of nondiazotrophic phytoplankton growth in order to infer seasonally varying patterns of colimitation by light, nitrogen (N), and phosphorus (P) in the global ocean. Our combined model-data analysis suggests strong N and N-P colimitation in the tropical ocean, seasonal light, and N-P colimitation in the Northern Hemisphere, and strong light limitation only during winter in the Southern Ocean. The eastern equatorial Pacific appears as the only ocean area that is essentially not limited by N, P, or light. Even though our optimality-based approach specifically accounts for flexible stoichiometry, inferred patterns of N and P limitation are to some extent consistent with those obtained from an analysis of surface inorganic nutrients with respect to the Redfield N:P ratio. Iron is not part of our analysis, implying that we cannot accurately predict N cell quotas in high-nutrient, low-chlorophyll regions. Elsewhere, we do not expect a major effect of iron on the relative distribution of N, P, and light colimitation areas. The relative importance of N, P, and light in limiting phytoplankton growth diagnosed here by combining observations and an optimal growth model provides a useful constraint for models used to predict future marine biological production under changing environmental conditions. 2014. American Geophysical Union. All Rights Reserved.

  8. A Hybrid dasymetric and machine learning approach to high-resolution residential electricity consumption modeling

    SciTech Connect

    Morton, April M; Nagle, Nicholas N; Piburn, Jesse O; Stewart, Robert N; McManamay, Ryan A

    2017-01-01

    As urban areas continue to grow and evolve in a world of increasing environmental awareness, the need for detailed information regarding residential energy consumption patterns has become increasingly important. Though current modeling efforts mark significant progress in the effort to better understand the spatial distribution of energy consumption, the majority of techniques are highly dependent on region-specific data sources and often require building- or dwelling-level details that are not publicly available for many regions in the United States. Furthermore, many existing methods do not account for errors in input data sources and may not accurately reflect inherent uncertainties in model outputs. We propose an alternative and more general hybrid approach to high-resolution residential electricity consumption modeling by merging a dasymetric model with a complementary machine learning algorithm. The method s flexible data requirement and statistical framework ensure that the model both is applicable to a wide range of regions and considers errors in input data sources.

  9. [Construction of conceptual model of data management for nutrient cycling research].

    PubMed

    Shi, Jianping; Sun, Bo; Yang, Linzhang

    2003-11-01

    A large amount of data have been accumulated from the agro-ecosystem nutrient cycling research during recent years. It is necessary to develop a data management system for global decision-making and for preserving from loss. This paper outlined a conceptual model design based on Entity-Relation (E-R) model, presented the model constructing process from user query, and demonstrated a database system using a given model. The results showed that the database implemented from the designed model could provide the function of querying in terms of time, location and theme, and management of various types of data, such as field observation, theme map and research report, and fast extracting and analysis data with spatio-temporal characteristic.

  10. NEW FEATURES OF SIMSAFADIM NUMERICAL MODEL: inclusion of nutrients as a carbonate production factor and sediment compaction

    NASA Astrophysics Data System (ADS)

    Clavera-Gispert, R.; Carmona, A.; Tolosana-Delgado, R.; Gratacós, O.; Bitzer, K.

    2009-04-01

    Carbonate-sedimentary environments are characterized by different groups of organisms living together and competing for space, nutrients and other life-determining factors. The 3D simulation model SIMSAFADIM is used to simulate these environments. In its original state, SIMSAFADIM was a 3D forward process-based model for simulation of stratigraphic architecture and facies distribution in sedimentary basins. It was developed by Bitzer, Salas and Gratacós and considers clastic and carbonate sediments. In a first step, the model simulated carbonate production and sedimentation controlled by water depth, presence of clastic sediments, carbonate mud and predator-prey factors among three species. However other factors are important in carbonate producer species like nutrient supply, which is included in the new version of this code. Nutrients play an important role in species life, because nutrients control which species can appear and how do they grow. Each species needs a specific range of nutrient concentration to grow. Then marine environments are classified in three main groups, depending on their nutrients concentration: oligotrophic, mesotrophic and eutrophic. To model the new environmental variable, the code works with nutrients like any other 'sediment'. These are incorporated into the fluid and flow like clastic sediments, but nutrients are consumed by species and not settled down. The code considers a special situation, when a marine transgression occurs. In this case, when the sea level rises and floods new areas, these flooded areas contribute with an extra concentration of nutrients inflow. Furthermore the program adds a new module to calculate compaction of clastic and carbonate sediments using the deMarsily formulation that follows Terzaghi's consolidation theory.

  11. Dynamics of a producer-grazer model incorporating the effects of excess food nutrient content on grazer's growth.

    PubMed

    Peace, Angela; Wang, Hao; Kuang, Yang

    2014-09-01

    Modeling under the framework of ecological stoichiometric allows the investigation of the effects of food quality on food web population dynamics. Recent discoveries in ecological stoichiometry suggest that grazer dynamics are affected by insufficient food nutrient content (low phosphorus (P)/carbon (C) ratio) as well as excess food nutrient content (high P:C). This phenomenon is known as the "stoichiometric knife edge." While previous models have captured this phenomenon, they do not explicitly track P in the producer or in the media that supports the producer, which brings questions to the validity of their predictions. Here, we extend a Lotka-Volterra-type stoichiometric model by mechanistically deriving and tracking P in the producer and free P in the environment in order to investigate the growth response of Daphnia to algae of varying P:C ratios. Bifurcation analysis and numerical simulations of the full model, that explicitly tracks phosphorus, lead to quantitative different predictions than previous models that neglect to track free nutrients. The full model shows that the fate of the grazer population can be very sensitive to excess nutrient concentrations. Dynamical free nutrient pool seems to induce extreme grazer population density changes when total nutrient is in an intermediate range.

  12. Evaluating the Power Consumption of Wireless Sensor Network Applications Using Models

    PubMed Central

    Dâmaso, Antônio; Freitas, Davi; Rosa, Nelson; Silva, Bruno; Maciel, Paulo

    2013-01-01

    Power consumption is the main concern in developing Wireless Sensor Network (WSN) applications. Consequently, several strategies have been proposed for investigating the power consumption of this kind of application. These strategies can help to predict the WSN lifetime, provide recommendations to application developers and may optimize the energy consumed by the WSN applications. While measurement is a known and precise strategy for power consumption evaluation, it is very costly, tedious and may be unfeasible considering the (usual) large number of WSN nodes. Furthermore, due to the inherent dynamism of WSNs, the instrumentation required by measurement techniques makes difficult their use in several different scenarios. In this context, this paper presents an approach for evaluating the power consumption of WSN applications by using simulation models along with a set of tools to automate the proposed approach. Starting from a programming language code, we automatically generate consumption models used to predict the power consumption of WSN applications. In order to evaluate the proposed approach, we compare the results obtained by using the generated models against ones obtained by measurement. PMID:23486217

  13. Evaluating the power consumption of wireless sensor network applications using models.

    PubMed

    Dâmaso, Antônio; Freitas, Davi; Rosa, Nelson; Silva, Bruno; Maciel, Paulo

    2013-03-13

    Power consumption is the main concern in developing Wireless Sensor Network (WSN) applications. Consequently, several strategies have been proposed for investigating the power consumption of this kind of application. These strategies can help to predict the WSN lifetime, provide recommendations to application developers and may optimize the energy consumed by the WSN applications. While measurement is a known and precise strategy for power consumption evaluation, it is very costly, tedious and may be unfeasible considering the (usual) large number of WSN nodes. Furthermore, due to the inherent dynamism of WSNs, the instrumentation required by measurement techniques makes difficult their use in several different scenarios. In this context, this paper presents an approach for evaluating the power consumption of WSN applications by using simulation models along with a set of tools to automate the proposed approach. Starting from a programming language code, we automatically generate consumption models used to predict the power consumption of WSN applications. In order to evaluate the proposed approach, we compare the results obtained by using the generated models against ones obtained by measurement.

  14. A mechanistic model for electricity consumption on dairy farms: definition, validation, and demonstration.

    PubMed

    Upton, J; Murphy, M; Shalloo, L; Groot Koerkamp, P W G; De Boer, I J M

    2014-01-01

    Our objective was to define and demonstrate a mechanistic model that enables dairy farmers to explore the impact of a technical or managerial innovation on electricity consumption, associated CO2 emissions, and electricity costs. We, therefore, (1) defined a model for electricity consumption on dairy farms (MECD) capable of simulating total electricity consumption along with related CO2 emissions and electricity costs on dairy farms on a monthly basis; (2) validated the MECD using empirical data of 1yr on commercial spring calving, grass-based dairy farms with 45, 88, and 195 milking cows; and (3) demonstrated the functionality of the model by applying 2 electricity tariffs to the electricity consumption data and examining the effect on total dairy farm electricity costs. The MECD was developed using a mechanistic modeling approach and required the key inputs of milk production, cow number, and details relating to the milk-cooling system, milking machine system, water-heating system, lighting systems, water pump systems, and the winter housing facilities as well as details relating to the management of the farm (e.g., season of calving). Model validation showed an overall relative prediction error (RPE) of less than 10% for total electricity consumption. More than 87% of the mean square prediction error of total electricity consumption was accounted for by random variation. The RPE values of the milk-cooling systems, water-heating systems, and milking machine systems were less than 20%. The RPE values for automatic scraper systems, lighting systems, and water pump systems varied from 18 to 113%, indicating a poor prediction for these metrics. However, automatic scrapers, lighting, and water pumps made up only 14% of total electricity consumption across all farms, reducing the overall impact of these poor predictions. Demonstration of the model showed that total farm electricity costs increased by between 29 and 38% by moving from a day and night tariff to a flat

  15. Modeling nutrient cycling in the North Pacific Subtropical Gyre using an eddy-resolving ocean ecosystem model

    NASA Astrophysics Data System (ADS)

    Hiraike, Yuri; Hasumi, Hiroyasu; Itoh, Sachihiko

    2013-04-01

    An eddy-resolving ecosystem model of the North Pacific is used to investigate the impact of mesoscale eddies on the basin-scale nitrate circulation and supply to the euphotic zone. A simple lower trophic level NPZD ecosystem model with iron limitation on nutrient uptake is coupled to a three dimensional off-line ocean circulation model. The model horizontal resolution is 1/10° × 1/10° cosθ. The focus is on the North Pacific Subtropical Gyre (NPSG) where nitrate in the euphotic zone is low by downwelling due to the Ekman convergence. Recent observational and model studies reveal that the mesoscale eddies have significant impact on oceanic biological production in subtropical gyres. Although there are many studies on mesoscale eddies, a basin-scale picture of impact of mesoscale eddies on nitrate circulation and supply to the euphotic zone is presently poorly known. In the Kuroshio Extension (KE) region, the mesoscale eddies exchange water across the front and affect the biological production. In addition, recent model studies show that the mesoscale eddies contribute to the formation and transport of the Subtropical Model Water (STMW). Although it is suggested that the STMW forms in the KE region and is transported to the NPSG, the effect of the STMW on the nitrate circulation and impact on the biological production in the NPSG is not clear. In addition, the STMW is thought to be important in forming of the Subtropical Countercurrent (STCC) which has large mesoscale eddy activities in the NPSG. It is expected that the seasonal variability of the STCC dominates the seasonal variability of biological production. The results from the eddy-resolving model are compared with results from a low-resolution model. The results of sensitivity experiments to model parameters model parameters are also shown. It is expected that tracer experiments and analysis of nutrient budged reveal eddy effect on the basin-scale nutrient circulation and supply to the euphotic zone in the

  16. Input-output modeling for urban energy consumption in Beijing: dynamics and comparison.

    PubMed

    Zhang, Lixiao; Hu, Qiuhong; Zhang, Fan

    2014-01-01

    Input-output analysis has been proven to be a powerful instrument for estimating embodied (direct plus indirect) energy usage through economic sectors. Using 9 economic input-output tables of years 1987, 1990, 1992, 1995, 1997, 2000, 2002, 2005, and 2007, this paper analyzes energy flows for the entire city of Beijing and its 30 economic sectors, respectively. Results show that the embodied energy consumption of Beijing increased from 38.85 million tonnes of coal equivalent (Mtce) to 206.2 Mtce over the past twenty years of rapid urbanization; the share of indirect energy consumption in total energy consumption increased from 48% to 76%, suggesting the transition of Beijing from a production-based and manufacturing-dominated economy to a consumption-based and service-dominated economy. Real estate development has shown to be a major driving factor of the growth in indirect energy consumption. The boom and bust of construction activities have been strongly correlated with the increase and decrease of system-side indirect energy consumption. Traditional heavy industries remain the most energy-intensive sectors in the economy. However, the transportation and service sectors have contributed most to the rapid increase in overall energy consumption. The analyses in this paper demonstrate that a system-wide approach such as that based on input-output model can be a useful tool for robust energy policy making.

  17. Evolution of consumption distribution and model of wealth distribution in China between 1995 and 2012

    NASA Astrophysics Data System (ADS)

    Gao, Li

    2015-07-01

    We study the evolution of the distribution of consumption of individuals in the majority population in China during the period 1995-2012 and find that its probability density functions (PDFs) obey the rule Pc(x) = K(x - μ) e-(x - μ)2/2σ2. We also find (i) that the PDFs and the individual income distribution appear to be identical, (ii) that the peaks of the PDFs of the individual consumption distribution are consistently on the low side of the PDFs of the income distribution, and (iii) that the average of the marginal propensity to consume (MPC) is large, MPC bar = 0.77, indicating that in the majority population individual consumption is low and strongly dependent on income. The long right tail of the PDFs of consumption indicates that few people in China are participating in the high consumption economy, and that consumption inequality is high. After comparing the PDFs of consumption with the PDFs of income we obtain the PDFs of residual wealth during the period 1995-2012, which exhibit a Gaussian distribution. We use an agent-based kinetic wealth-exchange model (KWEM) to simulate this evolutional process and find that this Gaussian distribution indicates a strong propensity to save rather than spend. This may be due to an anticipation of such large potential outlays as housing, education, and health care in the context of an inadequate welfare support system.

  18. Input-Output Modeling for Urban Energy Consumption in Beijing: Dynamics and Comparison

    PubMed Central

    Zhang, Lixiao; Hu, Qiuhong; Zhang, Fan

    2014-01-01

    Input-output analysis has been proven to be a powerful instrument for estimating embodied (direct plus indirect) energy usage through economic sectors. Using 9 economic input-output tables of years 1987, 1990, 1992, 1995, 1997, 2000, 2002, 2005, and 2007, this paper analyzes energy flows for the entire city of Beijing and its 30 economic sectors, respectively. Results show that the embodied energy consumption of Beijing increased from 38.85 million tonnes of coal equivalent (Mtce) to 206.2 Mtce over the past twenty years of rapid urbanization; the share of indirect energy consumption in total energy consumption increased from 48% to 76%, suggesting the transition of Beijing from a production-based and manufacturing-dominated economy to a consumption-based and service-dominated economy. Real estate development has shown to be a major driving factor of the growth in indirect energy consumption. The boom and bust of construction activities have been strongly correlated with the increase and decrease of system-side indirect energy consumption. Traditional heavy industries remain the most energy-intensive sectors in the economy. However, the transportation and service sectors have contributed most to the rapid increase in overall energy consumption. The analyses in this paper demonstrate that a system-wide approach such as that based on input-output model can be a useful tool for robust energy policy making. PMID:24595199

  19. Quantifying nutrient export and deposition with a dynamic landscape evolution model for the lake Bolsena watershed, Italy

    NASA Astrophysics Data System (ADS)

    Pelorosso, Raffaele; Temme, Arnoud; Gobattoni, Federica; Leone, Antonio

    2010-05-01

    Excessive nutrient loads from upstream watershed activities such as agriculture, hydrological modifications, and urban runoff, have been identified as the leading cause of deterioration in assessed lakes and reservoirs (USEPA, 2000; Leone et al., 2001; Leone et al., 2003). Excessive nutrient transport into lakes and reservoirs may accelerate eutrophication rates, causing negative impacts on aesthetic and water quality. As reservoirs become eutrophic, they are depleted in oxygen and enriched in suspended solids, with heavy consequences for ecosystems and natural habitats. Management of nutrient loads into reservoirs requires knowledge of nutrient transport and delivery from the watershed-stream system (Ripa, 2003). Managing uncultivated lands in watersheds may be a cost effective way to improve water quality in agricultural landscapes, and recent advances in landscape ecology highlight important relationships between the structural configuration of these lands and nutrient redistribution (e.g., Forman 1987; Barrett and others 1990). Many studies have been carried out to underline and explain how landscape characteristics and structure may affect these processes. In these studies, relations between land cover and nutrient storage were analyzed using geographic information systems (GIS) (e.g. Lucas, 2002). Nutrients are generally transported from the landscape into streams during runoff events; however, they may also enter stream flow from other sources such as groundwater recharge and point source effluent discharges (Lucas, 2002; Nielsen, 2007; Waldron, 2008; Castillo, 2009). Water moves nutrients and delivers them to downstream water bodies such as lakes and reservoirs so that erosion phenomena play an essential role in determining nutrients fluxes and deposition. On the one hand, several hydrological models take into account nutrients reactions, movements and deposition - coupling soil erosion processes with transport equations (Bartley, 2004; Lű, 2010). On the

  20. A scalable model for methane consumption in arctic mineral soils

    NASA Astrophysics Data System (ADS)

    Oh, Youmi; Stackhouse, Brandon; Lau, Maggie C. Y.; Xu, Xiangtao; Trugman, Anna T.; Moch, Jonathan; Onstott, Tullis C.; Jørgensen, Christian J.; D'Imperio, Ludovica; Elberling, Bo; Emmerton, Craig A.; St. Louis, Vincent L.; Medvigy, David

    2016-05-01

    Recent field studies have documented a surprisingly strong and consistent methane sink in arctic mineral soils, thought to be due to high-affinity methanotrophy. However, the distinctive physiology of these methanotrophs is poorly represented in mechanistic methane models. We developed a new model, constrained by microcosm experiments, to simulate the activity of high-affinity methanotrophs. The model was tested against soil core-thawing experiments and field-based measurements of methane fluxes and was compared to conventional mechanistic methane models. Our simulations show that high-affinity methanotrophy can be an important component of the net methane flux from arctic mineral soils. Simulations without this process overestimate methane emissions. Furthermore, simulations of methane flux seasonality are improved by dynamic simulation of active microbial biomass. Because a large fraction of the Arctic is characterized by mineral soils, high-affinity methanotrophy will likely have a strong effect on its net methane flux.

  1. Contribution of complementary food nutrients to estimated total nutrient intakes for rural Guatemalan infants in the second semester of life.

    PubMed

    Campos, Raquel; Hernandez, Liza; Soto-Mendez, Maria Jose; Vossenaar, Marieke; Solomons, Noel W

    2010-01-01

    In developing countries, complementary foods are often introduced earlier or later than appropriate and the quality is frequently insufficient, particularly in rural areas where complementary foods have traditionally been based on starchy gruels. Adequate intakes of a number of nutrients are recognized to be problematic in traditional complementary feeding regimens in developing societies. To determine the contribution of the complementary feeding nutrients to the estimated total nutrient intake in Guatemalan infants. Three non-consecutive 24-hr recalls were collected from a convenience sample of mothers of 64 infants, aged 6-12 month on enrolment, in the rural Guatemalan highland village of Santo Domingo Xenacoj. Additional information on early introduction of pre- and post-lacteal feeds and on first foods and beverages was included. Human milk intakes were estimated by a model based on assumptions regarding satisfaction of weight-based daily energy needs by the combined diet. The 2004 WHO/FAO recommended nutrient intakes were used as the standard for adequate nutrient consumption. We observed that exclusive breastfeeding up to 6 month is rare. Mean nutrient intakes and densities were above recommended intakes for all nutrients examined, except calcium, iron and zinc. Intakes of most nutrients were greater from the complementary feeding component of the diet. Vitamin A intake was excessive due to consumption of fortified sugar. We conclude that intakes of most micronutrients were near recommendation levels, unusual within the complementary feeding experience in scientific literature. Calcium, iron and zinc were identified as "problem nutrients" as persistently reported in developing countries.

  2. Modeling greenhouse gas emissions and nutrient transport in managed arable soils with a fully coupled hydrology-biogeochemical modeling system

    NASA Astrophysics Data System (ADS)

    Haas, Edwin; Klatt, Steffen; Kiese, Ralf; Butterbach-Bahl, Klaus; Kraft, Philipp; Breuer, Lutz

    2015-04-01

    The use of mineral nitrogen fertilizer sustains the global food production and therefore the livelihood of human kind. The rise in world population will put pressure on the global agricultural system to increase its productivity leading most likely to an intensification of mineral nitrogen fertilizer use. The fate of excess nitrogen and its distribution within landscapes is manifold. Process knowledge on the site scale has rapidly grown in recent years and models have been developed to simulate carbon and nitrogen cycling in managed ecosystems on the site scale. Despite first regional studies, the carbon and nitrogen cycling on the landscape or catchment scale is not fully understood. In this study we present a newly developed modelling approach by coupling the fully distributed hydrology model CMF (catchment modelling framework) to the process based regional ecosystem model LandscapeDNDC for the investigation of hydrological processes and carbon and nitrogen transport and cycling, with a focus on nutrient displacement and resulting greenhouse gas emissions in various virtual landscapes / catchment to demonstrate the capabilities of the modelling system. The modelling system was applied to simulate water and nutrient transport at the at the Yanting Agro-ecological Experimental Station of Purple Soil, Sichuan province, China. The catchment hosts cypress forests on the outer regions, arable fields on the sloping croplands cultivated with wheat-maize rotations and paddy rice fields in the lowland. The catchment consists of 300 polygons vertically stratified into 10 soil layers. Ecosystem states (soil water content and nutrients) and fluxes (evapotranspiration) are exchanged between the models at high temporal scales (hourly to daily) forming a 3-dimensional model application. The water flux and nutrients transport in the soil is modelled using a 3D Richards/Darcy approach for subsurface fluxes with a kinematic wave approach for surface water runoff and the

  3. Uncertainties in fuel loading and fire consumption calculations and the Smoke and Emissions Model Intercomparison Project

    NASA Astrophysics Data System (ADS)

    Larkin, N.; Solomon, R.; Strand, T.; Raffuse, S. M.; Craig, K.

    2009-12-01

    Fire and fuel managers often need to know how much fuel will be consumed by a fire, and how much smoke the fire will produce. Many factors influence the end result, including fuel type, loading, and moisture, quantity of live and dead fuels, terrain, and meteorology. A variety of fuel models and consumption models have been developed to help provide estimated quantities of fuel consumption and subsequent smoke production. We present results from this work, done as part of the Smoke and Emissions Model Intercomparison Project that show that the specific choice of model and model coupling can have a large effect on the final answer. We have used four different consumption models (CONSUME3, EPM, FEPS, and FOFEM) with three different fuel loading maps (NFDRS, Hardy, FCCS) to bracket the simulated results. A new web-based database viewer now allows both scientists and land and fire managers to directly compare various results by selecting a fuel loading map and consumption model. For model users interested in information for a specific fire these comparisons can be useful in understanding the uncertainties resulting from different model choices.

  4. Modeling nutrient retention in the coastal zone of an eutrophic sea - a model study in the Stockholm Archipelago, Sweden

    NASA Astrophysics Data System (ADS)

    Almroth-Rosell, Elin; Edman, Moa; Eilola, Kari; Meier, Markus; Sahlberg, Jörgen

    2016-04-01

    This study shows that the Stockholm archipelago works as a filter for nutrients that enters the coastal zone from land. The filter capacity is high, but not effective enough to take care of all the nutrients that the system receives. At least 65 % and 72 % of the phosphorus (P) and nitrogen (N), respectively, is retained. The multi-basin one dimensional Swedish Coastal zone Model (SCM) that was used is based on the Swedish Coastal and Ocean Biogeochemical model (SCOBI) coupled to the equation solver PROgram for Boundary layers in the Environment (PROBE). An evaluation of model results showed that the nutrient, salinity and temperature dynamics in the SCM model are of good quality. To analyse the results the Stockholm archipelago was divided into three sub-areas: the inner, the intermediate and the outer archipelago. The analysis showed that the highest total amounts of P and N are retained in the outer archipelago where the surface area is largest. The area weighted retention of P and N, however, is highest in the smaller inner archipelago and decreases towards the open sea. A major part of the retention is permanent. For P sediment burial is the only permanent retention mechanism, but for N almost 92 % of the permanent retention is caused by benthic denitrification, less than 8 % by burial, while pelagic denitrification is below 1%. A reduction of the land load of nutrients (P reduced with 13 % and N with 20%) resulted in increased retention capacity of N and P and lowered the transport of N out from the archipelago. About 15 years after the reduction P is imported into the archipelago instead of being exported.

  5. Underestimation of boreal soil carbon stocks by mathematical soil carbon models linked to soil nutrient status

    NASA Astrophysics Data System (ADS)

    Ťupek, Boris; Ortiz, Carina A.; Hashimoto, Shoji; Stendahl, Johan; Dahlgren, Jonas; Karltun, Erik; Lehtonen, Aleksi

    2016-08-01

    Inaccurate estimate of the largest terrestrial carbon pool, soil organic carbon (SOC) stock, is the major source of uncertainty in simulating feedback of climate warming on ecosystem-atmosphere carbon dioxide exchange by process-based ecosystem and soil carbon models. Although the models need to simplify complex environmental processes of soil carbon sequestration, in a large mosaic of environments a missing key driver could lead to a modeling bias in predictions of SOC stock change.We aimed to evaluate SOC stock estimates of process-based models (Yasso07, Q, and CENTURY soil sub-model v4) against a massive Swedish forest soil inventory data set (3230 samples) organized by a recursive partitioning method into distinct soil groups with underlying SOC stock development linked to physicochemical conditions.For two-thirds of measurements all models predicted accurate SOC stock levels regardless of the detail of input data, e.g., whether they ignored or included soil properties. However, in fertile sites with high N deposition, high cation exchange capacity, or moderately increased soil water content, Yasso07 and Q models underestimated SOC stocks. In comparison to Yasso07 and Q, accounting for the site-specific soil characteristics (e. g. clay content and topsoil mineral N) by CENTURY improved SOC stock estimates for sites with high clay content, but not for sites with high N deposition.Our analysis suggested that the soils with poorly predicted SOC stocks, as characterized by the high nutrient status and well-sorted parent material, indeed have had other predominant drivers of SOC stabilization lacking in the models, presumably the mycorrhizal organic uptake and organo-mineral stabilization processes. Our results imply that the role of soil nutrient status as regulator of organic matter mineralization has to be re-evaluated, since correct SOC stocks are decisive for predicting future SOC change and soil CO2 efflux.

  6. Identification of a nutrient-sensing transcriptional network in monocytes by using inbred rat models on a cafeteria diet

    PubMed Central

    Martínez-Micaelo, Neus; González-Abuín, Noemi; Terra, Ximena; Ardévol, Ana; Pinent, Montserrat; Petretto, Enrico; Blay, Mayte

    2016-01-01

    ABSTRACT Obesity has reached pandemic levels worldwide. The current models of diet-induced obesity in rodents use predominantly high-fat based diets that do not take into account the consumption of variety of highly palatable, energy-dense foods that are prevalent in Western society. We and others have shown that the cafeteria (CAF) diet is a robust and reproducible model of human metabolic syndrome with tissue inflammation in the rat. We have previously shown that inbred rat strains such as Wistar Kyoto (WKY) and Lewis (LEW) show different susceptibilities to CAF diets with distinct metabolic and morphometric profiles. Here, we show a difference in plasma MCP-1 levels and investigate the effect of the CAF diet on peripheral blood monocyte transcriptome, as powerful stress-sensing immune cells, in WKY and LEW rats. We found that 75.5% of the differentially expressed transcripts under the CAF diet were upregulated in WKY rats and were functionally related to the activation of the immune response. Using a gene co-expression network constructed from the genes differentially expressed between CAF diet-fed LEW and WKY rats, we identified acyl-CoA synthetase short-chain family member 2 (Acss2) as a hub gene for a nutrient-sensing cluster of transcripts in monocytes. The Acss2 genomic region is significantly enriched for previously established metabolism quantitative trait loci in the rat. Notably, monocyte expression levels of Acss2 significantly correlated with plasma glucose, triglyceride, leptin and non-esterified fatty acid (NEFA) levels as well as morphometric measurements such as body weight and the total fat following feeding with the CAF diet in the rat. These results show the importance of the genetic background in nutritional genomics and identify inbred rat strains as potential models for CAF-diet-induced obesity. PMID:27483348

  7. Identification of a nutrient-sensing transcriptional network in monocytes by using inbred rat models on a cafeteria diet.

    PubMed

    Martínez-Micaelo, Neus; González-Abuín, Noemi; Terra, Ximena; Ardévol, Ana; Pinent, Montserrat; Petretto, Enrico; Behmoaras, Jacques; Blay, Mayte

    2016-10-01

    Obesity has reached pandemic levels worldwide. The current models of diet-induced obesity in rodents use predominantly high-fat based diets that do not take into account the consumption of variety of highly palatable, energy-dense foods that are prevalent in Western society. We and others have shown that the cafeteria (CAF) diet is a robust and reproducible model of human metabolic syndrome with tissue inflammation in the rat. We have previously shown that inbred rat strains such as Wistar Kyoto (WKY) and Lewis (LEW) show different susceptibilities to CAF diets with distinct metabolic and morphometric profiles. Here, we show a difference in plasma MCP-1 levels and investigate the effect of the CAF diet on peripheral blood monocyte transcriptome, as powerful stress-sensing immune cells, in WKY and LEW rats. We found that 75.5% of the differentially expressed transcripts under the CAF diet were upregulated in WKY rats and were functionally related to the activation of the immune response. Using a gene co-expression network constructed from the genes differentially expressed between CAF diet-fed LEW and WKY rats, we identified acyl-CoA synthetase short-chain family member 2 (Acss2) as a hub gene for a nutrient-sensing cluster of transcripts in monocytes. The Acss2 genomic region is significantly enriched for previously established metabolism quantitative trait loci in the rat. Notably, monocyte expression levels of Acss2 significantly correlated with plasma glucose, triglyceride, leptin and non-esterified fatty acid (NEFA) levels as well as morphometric measurements such as body weight and the total fat following feeding with the CAF diet in the rat. These results show the importance of the genetic background in nutritional genomics and identify inbred rat strains as potential models for CAF-diet-induced obesity.

  8. Modeling of Nutrient Transport and the Onset of Hypoxia in a Microfluidic Cell Culture Environment

    NASA Astrophysics Data System (ADS)

    Morshed, Adnan; Dutta, Prashanta

    2016-11-01

    Transport of essential nutrients such as oxygen and ascorbate plays a critical role in dictating tumor growth. For example, hypoxia, the depletion of intracellular oxygen levels below 6%, initiates major changes in cellular dynamics causing tumor cell survival. The intercapillary distance (distance between blood vessels) across a colony of growing tumor cells and the flow around the colony are important factors for the initiation of hypoxia. In this study, the dynamics of intracellular species inside a colony of tumor cells are investigated by varying the flow and unsteady permeation in a microfluidic cell culture device. The oxygen transport across the cell membrane is modeled through diffusion, while ascorbate transport from plasma is addressed by a concentration dependent uptake model. Our model shows that the onset of hypoxia is possible in HeLa cell within the first minute of total extracellular oxygen deprivation. This eventually leads to anoxia inside the cell block representing the development of a necrotic core that maintains a dynamic balance with growing cells and scarce supply. Results also indicate that the intercapillary distance and flow rate of nutrients can alter this balance, which has implications in the progression of hypoxic response. This work was supported in part by the U.S. National Science Foundation under Grant No. DMS 1317671.

  9. Evolutionary Tuning of Building Models to Monthly Electrical Consumption

    SciTech Connect

    Garrett, Aaron; New, Joshua Ryan; Chandler, Theodore

    2013-01-01

    Building energy models of existing buildings are unreliable unless calibrated so they correlate well with actual energy usage. Calibrating models is costly because it is currently an art which requires significant manual effort by an experienced and skilled professional. An automated methodology could significantly decrease this cost and facilitate greater adoption of energy simulation capabilities into the marketplace. The Autotune project is a novel methodology which leverages supercomputing, large databases of simulation data, and machine learning to allow automatic calibration of simulations to match measured experimental data on commodity hardware. This paper shares initial results from the automated methodology applied to the calibration of building energy models (BEM) for EnergyPlus (E+) to reproduce measured monthly electrical data.

  10. Factors affecting stream nutrient loads: A synthesis of regional SPARROW model results for the continental United States

    USGS Publications Warehouse

    Preston, Stephen D.; Alexander, Richard B.; Schwarz, Gregory E.; Crawford, Charles G.

    2011-01-01

    We compared the results of 12 recently calibrated regional SPARROW (SPAtially Referenced Regressions On Watershed attributes) models covering most of the continental United States to evaluate the consistency and regional differences in factors affecting stream nutrient loads. The models - 6 for total nitrogen and 6 for total phosphorus - all provide similar levels of prediction accuracy, but those for major river basins in the eastern half of the country were somewhat more accurate. The models simulate long-term mean annual stream nutrient loads as a function of a wide range of known sources and climatic (precipitation, temperature), landscape (e.g., soils, geology), and aquatic factors affecting nutrient fate and transport. The results confirm the dominant effects of urban and agricultural sources on stream nutrient loads nationally and regionally, but reveal considerable spatial variability in the specific types of sources that control water quality. These include regional differences in the relative importance of different types of urban (municipal and industrial point vs. diffuse urban runoff) and agriculture (crop cultivation vs. animal waste) sources, as well as the effects of atmospheric deposition, mining, and background (e.g., soil phosphorus) sources on stream nutrients. Overall, we found that the SPARROW model results provide a consistent set of information for identifying the major sources and environmental factors affecting nutrient fate and transport in United States watersheds at regional and subregional scales. ?? 2011 American Water Resources Association. This article is a U.S. Government work and is in the public domain in the USA.

  11. Reducing Income Inequalities in Food Consumption: Explorations With an Agent-Based Model.

    PubMed

    Blok, David J; de Vlas, Sake J; Bakker, Roel; van Lenthe, Frank J

    2015-10-01

    Individual and environmental factors dynamically interact in shaping income inequalities in healthy food consumption. The agent-based model, Health Behaviors Simulation (HEBSIM), was developed to describe income inequalities in healthy food consumption. It simulates interactions between households and their environment. HEBSIM was used to explore the impact of interventions aimed at reducing food consumption inequalities. HEBSIM includes households and food outlets. Households are characterized by location, composition, income, and preference for food. Decisions about where to shop for food (fruit/vegetable stores, supermarkets, or discount supermarkets) and whether to visit fast food outlets are based on distance, price, and food preference. Food outlets can close and new food outlets can enter the system. Three interventions to reduce healthy food consumption inequalities were tested: (1) eliminating residential segregation; (2) lowering the prices of healthy food; and (3) providing health education. HEBSIM was quantified using data from Statistics Netherlands, Statistics Eindhoven, and the GLOBE study (2011). The model mimicked food consumption in Eindhoven. High-income households visited healthy food shops more often than low-income households. Eliminating residential segregation had the largest impact in reducing income inequalities in food consumption, but resulted partly from a worsening in healthy food consumption in high-income households. Lowering prices and health education could also substantially reduce inequalities. Most interventions took 5-10 years to reach their (almost) full effects. HEBSIM is a promising tool for studying dynamic interactions between households and their environment and for assessing the impact of interventions on income inequalities in food consumption. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  12. An Application of Variational Theory to an Integrated Walrasian Model of Exchange, Consumption and Production

    NASA Astrophysics Data System (ADS)

    Donato, M. B.; Milasi, M.; Vitanza, C.

    2010-09-01

    An existence result of a Walrasian equilibrium for an integrated model of exchange, consumption and production is obtained. The equilibrium model is characterized in terms of a suitable generalized quasi-variational inequality; so the existence result comes from an original technique which takes into account tools of convex and set-valued analysis.

  13. Adolescents and Music Media: Toward an Involvement-Mediational Model of Consumption and Self-Concept

    ERIC Educational Resources Information Center

    Kistler, Michelle; Rodgers, Kathleen Boyce; Power, Thomas; Austin, Erica Weintraub; Hill, Laura Griner

    2010-01-01

    Using social cognitive theory and structural regression modeling, we examined pathways between early adolescents' music media consumption, involvement with music media, and 3 domains of self-concept (physical appearance, romantic appeal, and global self-worth; N=124). A mediational model was supported for 2 domains of self-concept. Music media…

  14. Adolescents and Music Media: Toward an Involvement-Mediational Model of Consumption and Self-Concept

    ERIC Educational Resources Information Center

    Kistler, Michelle; Rodgers, Kathleen Boyce; Power, Thomas; Austin, Erica Weintraub; Hill, Laura Griner

    2010-01-01

    Using social cognitive theory and structural regression modeling, we examined pathways between early adolescents' music media consumption, involvement with music media, and 3 domains of self-concept (physical appearance, romantic appeal, and global self-worth; N=124). A mediational model was supported for 2 domains of self-concept. Music media…

  15. Group theoretical modeling of thermal explosion with reactant consumption

    NASA Astrophysics Data System (ADS)

    Ibragimov, Ranis N.; Dameron, Michael

    2012-09-01

    Today engineering and science researchers routinely confront problems in mathematical modeling involving nonlinear differential equations. Many mathematical models formulated in terms of nonlinear differential equations can be successfully treated and solved by Lie group methods. Lie group analysis is especially valuable in investigating nonlinear differential equations, for its algorithms act as reliably as for linear cases. The aim of this article is to provide the group theoretical modeling of the symmetrical heating of an exothermally reacting medium with approximations to the body's temperature distribution similar to those made by Thomas [17] and Squire [15]. The quantitative results were found to be in a good agreement with Adler and Enig in [1], where the authors were comparing the integral curves corresponding to the critical conditions for the first-order reaction. Further development of the modeling by including the critical temperature is proposed. Overall, it is shown, in particular, that the application of Lie group analysis allows one to extend the previous analytic results for the first order reactions to nth order ones.

  16. Fresh pear consumption is associated with better nutrient intake, diet quality, and weight parameters in adults: National Health and Nutrition Examination Survey 2001-2010

    USDA-ARS?s Scientific Manuscript database

    No studies have examined the association of consuming fresh pears on nutrient intake or adequacy, diet quality, and cardiovascular risk factors (CVRF). The purpose of this study was to examine these association in adults (n=24,808) participating the NHANES 2001-2010. Covariate adjusted linear regres...

  17. A Parental Health Education Model of Children's Food Consumption: Influence on Children's Attitudes, Intention, and Consumption of Healthy and Unhealthy Foods.

    PubMed

    Lwin, May O; Shin, Wonsun; Yee, Andrew Z H; Wardoyo, Reidinar Juliane

    2017-03-31

    This study proposes that parental mediation of television advertising and parental guidance of food consumption differentially influence children's attitude, intention, and behavior toward the consumption of healthy and unhealthy foods. Structural equation modeling based on a survey of 1,119 children aged 9-12 supported our model, revealing that parental education strategies influence children's food consumption in a complex manner that is highly context-dependent. Parental guidance of food consumption enhanced children's healthy food attitude and intention to consume, while reducing the intention to consume unhealthy food. However, parental mediation of television advertising influenced unhealthy food attitude to a greater extent than healthy food attitude. Implications for health promotion and education, as well as parents and policy makers are discussed.

  18. Internal cycling, not external loading, decides the nutrient limitation in eutrophic lake: A dynamic model with temporal Bayesian hierarchical inference.

    PubMed

    Wu, Zhen; Liu, Yong; Liang, Zhongyao; Wu, Sifeng; Guo, Huaicheng

    2017-06-01

    Lake eutrophication is associated with excessive anthropogenic nutrients (mainly nitrogen (N) and phosphorus (P)) and unobserved internal nutrient cycling. Despite the advances in understanding the role of external loadings, the contribution of internal nutrient cycling is still an open question. A dynamic mass-balance model was developed to simulate and measure the contributions of internal cycling and external loading. It was based on the temporal Bayesian Hierarchical Framework (BHM), where we explored the seasonal patterns in the dynamics of nutrient cycling processes and the limitation of N and P on phytoplankton growth in hyper-eutrophic Lake Dianchi, China. The dynamic patterns of the five state variables (Chla, TP, ammonia, nitrate and organic N) were simulated based on the model. Five parameters (algae growth rate, sediment exchange rate of N and P, nitrification rate and denitrification rate) were estimated based on BHM. The model provided a good fit to observations. Our model results highlighted the role of internal cycling of N and P in Lake Dianchi. The internal cycling processes contributed more than external loading to the N and P changes in the water column. Further insights into the nutrient limitation analysis indicated that the sediment exchange of P determined the P limitation. Allowing for the contribution of denitrification to N removal, N was the more limiting nutrient in most of the time, however, P was the more important nutrient for eutrophication management. For Lake Dianchi, it would not be possible to recover solely by reducing the external watershed nutrient load; the mechanisms of internal cycling should also be considered as an approach to inhibit the release of sediments and to enhance denitrification. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Analytical solution of diffusion model for nutrient release from controlled release fertilizer

    NASA Astrophysics Data System (ADS)

    Ameenuddin Irfan, Sayed; Razali, Radzuan; KuShaari, KuZilati; Mansor, Nurlidia; Azeem, Babar

    2017-09-01

    An analytical method has been developed to solve the initial value problem which arises from Fick’s diffusion equation encountered in the modelling of the Controlled Release Fertilizers. The proposed analytical solution is developed using the modified Adomian decomposition method. This method does not require the discretization method, reliability and efficiency of this method is more and it also reduces the calculation time. The model has predicted the effect of granule radius and diffusion coefficient on the nutrient release and total release time of Controlled Release Fertilizer. Model has predicted that increase in the radius of granule reduces the release and vice versa in case of diffusion coefficient. Detailed understanding of these parameters helps in improved designing of Controlled Release Fertilizer.

  20. Design, development and validation of software for modelling dietary exposure to food chemicals and nutrients.

    PubMed

    McNamara, C; Naddy, B; Rohan, D; Sexton, J

    2003-10-01

    The Monte Carlo computational system for stochastic modelling of dietary exposure to food chemicals and nutrients is presented. This system was developed through a European Commission-funded research project. It is accessible as a Web-based application service. The system allows and supports very significant complexity in the data sets used as the model input, but provides a simple, general purpose, linear kernel for model evaluation. Specific features of the system include the ability to enter (arbitrarily) complex mathematical or probabilistic expressions at each and every input data field, automatic bootstrapping on subjects and on subject food intake diaries, and custom kernels to apply brand information such as market share and loyalty to the calculation of food and chemical intake.

  1. Incorporating uncertainty into the ranking of SPARROW model nutrient yields from Mississippi/Atchafalaya River basin watersheds

    USGS Publications Warehouse

    Robertson, Dale M.; Schwarz, Gregory E.; Saad, David A.; Alexander, Richard B.

    2009-01-01

    Excessive loads of nutrients transported by tributary rivers have been linked to hypoxia in the Gulf of Mexico. Management efforts to reduce the hypoxic zone in the Gulf of Mexico and improve the water quality of rivers and streams could benefit from targeting nutrient reductions toward watersheds with the highest nutrient yields delivered to sensitive downstream waters. One challenge is that most conventional watershed modeling approaches (e.g., mechanistic models) used in these management decisions do not consider uncertainties in the predictions of nutrient yields and their downstream delivery. The increasing use of parameter estimation procedures to statistically estimate model coefficients, however, allows uncertainties in these predictions to be reliably estimated. Here, we use a robust bootstrapping procedure applied to the results of a previous application of the hybrid statistical/mechanistic watershed model SPARROW (Spatially Referenced Regression On Watershed attributes) to develop a statistically reliable method for identifying “high priority” areas for management, based on a probabilistic ranking of delivered nutrient yields from watersheds throughout a basin. The method is designed to be used by managers to prioritize watersheds where additional stream monitoring and evaluations of nutrient-reduction strategies could be undertaken. Our ranking procedure incorporates information on the confidence intervals of model predictions and the corresponding watershed rankings of the delivered nutrient yields. From this quantified uncertainty, we estimate the probability that individual watersheds are among a collection of watersheds that have the highest delivered nutrient yields. We illustrate the application of the procedure to 818 eight-digit Hydrologic Unit Code watersheds in the Mississippi/Atchafalaya River basin by identifying 150 watersheds having the highest delivered nutrient yields to the Gulf of Mexico. Highest delivered yields were from

  2. Fit for consumption: zebrafish as a model for tuberculosis.

    PubMed

    Cronan, Mark R; Tobin, David M

    2014-07-01

    Despite efforts to generate new vaccines and antibiotics for tuberculosis, the disease remains a public health problem worldwide. The zebrafish Danio rerio has emerged as a useful model to investigate mycobacterial pathogenesis and treatment. Infection of zebrafish with Mycobacterium marinum, the closest relative of the Mycobacterium tuberculosis complex, recapitulates many aspects of human tuberculosis. The zebrafish model affords optical transparency, abundant genetic tools and in vivo imaging of the progression of infection. Here, we review how the zebrafish-M. marinum system has been deployed to make novel observations about the role of innate immunity, the tuberculous granuloma, and crucial host and bacterial genes. Finally, we assess how these findings relate to human disease and provide a framework for novel strategies to treat tuberculosis. © 2014. Published by The Company of Biologists Ltd.

  3. Mathematical model of galactose regulation and metabolic consumption in yeast.

    PubMed

    Mitre, Tina M; Mackey, Michael C; Khadra, Anmar

    2016-10-21

    The galactose network has been extensively studied at the unicellular level to broaden our understanding of the regulatory mechanisms governing galactose metabolism in multicellular organisms. Although the key molecular players involved in the metabolic and regulatory processes of this system have been known for decades, their interactions and chemical kinetics remain incompletely understood. Mathematical models can provide an alternative method to study the dynamics of this network from a quantitative and a qualitative perspective. Here, we employ this approach to unravel the main properties of the galactose network, including equilibrium binary and temporal responses, as a way to decipher its adaptation to actively-changing inputs. We combine its two main components: the genetic branch, which allows for bistable responses, and a metabolic branch, encompassing the relevant metabolic processes that can be repressed by glucose. We use both computational tools to estimate model parameters based on published experimental data, as well as bifurcation analysis to decipher the properties of the system in various parameter regimes. Our model analysis reveals that the interplay between the inducer (galactose) and the repressor (glucose) creates a bistable regime which dictates the temporal responses of the system. Based on the same bifurcation techniques, we explain why the system is robust to genetic mutations and molecular instabilities. These findings may provide experimentalists with a theoretical framework with which they can determine how the galactose network functions under various conditions.

  4. CO2 enrichment and N addition increase nutrient loss from decomposing leaf litter in subtropical model forest ecosystems.

    PubMed

    Liu, Juxiu; Fang, Xiong; Deng, Qi; Han, Tianfeng; Huang, Wenjuan; Li, Yiyong

    2015-01-22

    As atmospheric CO2 concentration increases, many experiments have been carried out to study effects of CO2 enrichment on litter decomposition and nutrient release. However, the result is still uncertain. Meanwhile, the impact of CO2 enrichment on nutrients other than N and P are far less studied. Using open-top chambers, we examined effects of elevated CO2 and N addition on leaf litter decomposition and nutrient release in subtropical model forest ecosystems. We found that both elevated CO2 and N addition increased nutrient (C, N, P, K, Ca, Mg and Zn) loss from the decomposing litter. The N, P, Ca and Zn loss was more than tripled in the chambers exposed to both elevated CO2 and N addition than those in the control chambers after 21 months of treatment. The stimulation of nutrient loss under elevated CO2 was associated with the increased soil moisture, the higher leaf litter quality and the greater soil acidity. Accelerated nutrient release under N addition was related to the higher leaf litter quality, the increased soil microbial biomass and the greater soil acidity. Our results imply that elevated CO2 and N addition will increase nutrient cycling in subtropical China under the future global change.

  5. CO2 enrichment and N addition increase nutrient loss from decomposing leaf litter in subtropical model forest ecosystems

    NASA Astrophysics Data System (ADS)

    Liu, Juxiu; Fang, Xiong; Deng, Qi; Han, Tianfeng; Huang, Wenjuan; Li, Yiyong

    2015-01-01

    As atmospheric CO2 concentration increases, many experiments have been carried out to study effects of CO2 enrichment on litter decomposition and nutrient release. However, the result is still uncertain. Meanwhile, the impact of CO2 enrichment on nutrients other than N and P are far less studied. Using open-top chambers, we examined effects of elevated CO2 and N addition on leaf litter decomposition and nutrient release in subtropical model forest ecosystems. We found that both elevated CO2 and N addition increased nutrient (C, N, P, K, Ca, Mg and Zn) loss from the decomposing litter. The N, P, Ca and Zn loss was more than tripled in the chambers exposed to both elevated CO2 and N addition than those in the control chambers after 21 months of treatment. The stimulation of nutrient loss under elevated CO2 was associated with the increased soil moisture, the higher leaf litter quality and the greater soil acidity. Accelerated nutrient release under N addition was related to the higher leaf litter quality, the increased soil microbial biomass and the greater soil acidity. Our results imply that elevated CO2 and N addition will increase nutrient cycling in subtropical China under the future global change.

  6. CO2 enrichment and N addition increase nutrient loss from decomposing leaf litter in subtropical model forest ecosystems

    PubMed Central

    Liu, Juxiu; Fang, Xiong; Deng, Qi; Han, Tianfeng; Huang, Wenjuan; Li, Yiyong

    2015-01-01

    As atmospheric CO2 concentration increases, many experiments have been carried out to study effects of CO2 enrichment on litter decomposition and nutrient release. However, the result is still uncertain. Meanwhile, the impact of CO2 enrichment on nutrients other than N and P are far less studied. Using open-top chambers, we examined effects of elevated CO2 and N addition on leaf litter decomposition and nutrient release in subtropical model forest ecosystems. We found that both elevated CO2 and N addition increased nutrient (C, N, P, K, Ca, Mg and Zn) loss from the decomposing litter. The N, P, Ca and Zn loss was more than tripled in the chambers exposed to both elevated CO2 and N addition than those in the control chambers after 21 months of treatment. The stimulation of nutrient loss under elevated CO2 was associated with the increased soil moisture, the higher leaf litter quality and the greater soil acidity. Accelerated nutrient release under N addition was related to the higher leaf litter quality, the increased soil microbial biomass and the greater soil acidity. Our results imply that elevated CO2 and N addition will increase nutrient cycling in subtropical China under the future global change. PMID:25608664

  7. A single-equation study of US petroleum consumption: The role of model specificiation

    SciTech Connect

    Jones, C.T. )

    1993-04-01

    The price responsiveness of US petroleum consumption began to attract a great deal of attention following the unexpected and substantial oil price increases of 1973-74. There have been a number of large, multi-equation econometric studies of US energy demand since then which have focused primarily on estimating short run and long run price and income elasticities of individual energy resources (coal, oil, natural gas electricity) for various consumer sectors (residential, industrial, commercial). Following these early multi-equation studies there have been several single-equation studies of aggregate US petroleum consumption. When choosing an economic model specification for a single-equation study of aggregate US petroleum consumption, an easily estimated model that will provide unbiased price and income elasticity estimates and yield accurate forecasts is needed. Using Hendry's general-to-simple specification search technique and annual data to obtain a restricted, data-acceptable simplification of a general ADL model yielded GNP and short run price elasticities near the consensus estimates, but a long run price elasticity substantially smaller than existing estimates. Comparisons with three other seemingly acceptable simple-to-general models showed that popular model specifications often involve untested, unacceptable parameter restrictions. These models may also demonstrate poorer forecasting performance. Based on results, the general-to-simple approach appears to offer a more accurate methodology for generating superior forecast models of petroleum consumption and other energy use patterns.

  8. Testing an agent-based model of bacterial cell motility: How nutrient concentration affects speed distribution

    NASA Astrophysics Data System (ADS)

    Garcia, V.; Birbaumer, M.; Schweitzer, F.

    2011-08-01

    We revisit a recently proposed agent-based model of active biological motion and compare its predictions with own experimental findings for the speed distribution of bacterial cells, Salmonella typhimurium. Agents move according to a stochastic dynamics and use energy stored in an internal depot for metabolism and active motion. We discuss different assumptions of how the conversion from internal to kinetic energy d( v) may depend on the actual speed, to conclude that d 2 v ξ with either ξ = 2 or 1 < ξ < 2 are promising hypotheses. To test these, we compare the model's prediction with the speed distribution of bacteria which were obtained in media of different nutrient concentration and at different times. We find that both hypotheses are in line with the experimental observations, with ξ between 1.67 and 2.0. Regarding the influence of a higher nutrient concentration, we conclude that the take-up of energy by bacterial cells is indeed increased. But this energy is not used to increase the speed, with 40 μm/s as the most probable value of the speed distribution, but is rather spend on metabolism and growth.

  9. Quantifying Groundwater Nutrient Discharge to a Large Glacial Lake using a Watershed Loading Model

    NASA Astrophysics Data System (ADS)

    Schilling, K. E.

    2015-12-01

    Groundwater discharge to a lake is an important, if often neglected, component to water and nutrient budgets. Point measurements of groundwater discharge into a lake are prone to error, so in this study of 15.57 km2 West Lake Okoboji, Iowa, a watershed-based groundwater loading model was developed. Located in northwest Iowa, West Lake Okoboji is considered one of Iowa's premier tourist destinations but is threatened by eutrophication. A network of 21 observation wells was installed in the watershed to evaluate groundwater recharge and quality under representative land cover types in a range of landscape positions. Our objective was to develop typical groundwater responses from various land cover-landscape associations for scaling up to unmonitored areas in the watershed. Results indicated substantial variation in groundwater recharge and quality in the 3847 ha watershed. Recharge was similar among land covers under vegetation but was much lower under urban pavement. Nitrate-nitrogen concentrations were highest under cropped fields and lowest under perennial grassland and golf courses, whereas dissolved phosphorus was highest under residential and urban areas, including an engineered bioswale. A groundwater load allocation model indicated 91% of the nitrate load was from cropped areas and 7% from residential areas. In contrast, P loads were more equally divided among cropped fields (43%), perennial grass (36%) and residential (19%) areas. Based on the mass of nitrate and P in the lake, groundwater accounts for 71% and 18% of the nutrient inputs, respectively.

  10. Consumption of various forms of apples is associated with a better nutrient intake and improved nutrient adequacy in diets of children: National Health and Nutrition Examination Survey 2003-2010

    USDA-ARS?s Scientific Manuscript database

    Consumption of fruit has been associated with a variety of health benefits, yet, 75% of children have usual intakes of total fruit below minimum recommended amounts. Apples are the second most commonly consumed fruit in the United States; however, no studies have examined the impact of apple consump...

  11. Annual nutrients export modelling by analysis of landuse and topographic information: case of a small Mediterranean catchment.

    PubMed

    Payraudeau, S; Tournoud, M G; Cernesson, F; Picot, B

    2001-01-01

    The preservation of water bodies from eutrophication implies accurate estimation of phosphorus and nitrogen loads and the control of nutrient production on a catchment scale. In this paper, a simple tool for the modelling of annual nutrient loads is presented. It is implemented in ARC/INFO GIS using Arc Macro Language (AML). The use of a GIS is justified as the spatial characteristics of the catchment area (land use, industrial wastewater location) dictate water quality. The annual nutrient loads are worked out on the catchment scale, using existing GIS routines together with specific routines developed in AML for hydrological and water quality modelling purposes. The catchment area is divided into hydrological subcatchments with relatively homogeneous spatial characteristics. Each subcatchment is linked to a specific nutrient export potential. These nutrient loads, calculated on a subcatchment-by-subcatchment basis, are conveyed to the outlet of the catchment and allow annual nutrient load estimation. A comparison with a water monitoring study is conducted to verify the adequation of modelling results for phosphorus and nitrogen loads.

  12. Multi-nutrient, multi-group model of present and future oceanic phytoplankton communities

    NASA Astrophysics Data System (ADS)

    Litchman, E.; Klausmeier, C. A.; Miller, J. R.; Schofield, O. M.; Falkowski, P. G.

    2006-06-01

    Phytoplankton community composition profoundly influences patterns of nutrient cycling and the structure of marine food webs; therefore predicting present and future phytoplankton community structure is of fundamental importance to understanding how ocean ecosystems are influenced by physical forcing and nutrient limitations. In this paper, we develop a mechanistic model of phytoplankton communities that includes multiple taxonomic groups, test the model at two contrasting sites in the modern ocean, and then use the model to predict community reorganization under different global change scenarios. The model includes three phytoplankton functional groups (diatoms, coccolithophores, and prasinophytes), five nutrients (nitrate, ammonium, phosphate, silicate and iron), light, and a generalist zooplankton grazer. Each taxonomic group was parameterized based on an extensive literature survey. The model successfully predicts the general patterns of community structure and succession in contrasting parts of the world ocean, the North Atlantic (North Atlantic Bloom Experiment, NABE) and subarctic North Pacific (ocean station Papa, OSP). In the North Atlantic, the model predicts a spring diatom bloom, followed by coccolithophore and prasinophyte blooms later in the season. The diatom bloom becomes silica-limited and the coccolithophore and prasinophyte blooms are controlled by nitrogen, grazers and by deep mixing and decreasing light availability later in the season. In the North Pacific, the model reproduces the low chlorophyll community dominated by prasinophytes and coccolithophores, with low total biomass variability and high nutrient concentrations throughout the year. Sensitivity analysis revealed that the identity of the most sensitive parameters and the range of acceptable parameters differed between the two sites. Five global change scenarios are used to drive the model and examine how community dynamics might change in the future. To estimate uncertainty in our

  13. Modeling energy flow and nutrient cycling in natural semiarid grassland ecosystems with the aid of thematic mapper data

    NASA Technical Reports Server (NTRS)

    Lewis, James K.

    1987-01-01

    Energy flow and nutrient cycling were modeled as affected by herbivory on selected intensive sites along gradients of precipitation and soils, validating the model output by monitoring selected parameters with data derived from the Thematic Mapper (TM). Herbivore production was modeled along the gradient of soils and herbivory, and validated with data derived from TM in a spatial data base.

  14. Glutamate prevents intestinal atrophy via luminal nutrient sensing in a mouse model of total parenteral nutrition.

    PubMed

    Xiao, Weidong; Feng, Yongjia; Holst, Jens J; Hartmann, Bolette; Yang, Hua; Teitelbaum, Daniel H

    2014-05-01

    Small intestine luminal nutrient sensing may be crucial for modulating physiological functions. However, its mechanism of action is incompletely understood. We used a model of enteral nutrient deprivation, or total parenteral nutrition (TPN), resulting in intestinal mucosal atrophy and decreased epithelial barrier function (EBF). We examined how a single amino acid, glutamate (GLM), modulates intestinal epithelial cell (IEC) growth and EBF. Controls were chow-fed mice, T1 receptor-3 (T1R3)-knockout (KO) mice, and treatment with the metabotropic glutamate receptor (mGluR)-5 antagonist MTEP. TPN significantly changed the amount of T1Rs, GLM receptors, and transporters, and GLM prevented these changes. GLM significantly prevented TPN-associated intestinal atrophy (2.5-fold increase in IEC proliferation) and was dependent on up-regulation of the protein kinase pAkt, but independent of T1R3 and mGluR5 signaling. GLM led to a loss of EBF with TPN (60% increase in FITC-dextran permeability, 40% decline in transepithelial resistance); via T1R3, it protected EBF, whereas mGluR5 was associated with EBF loss. GLM led to a decline in circulating glucagon-like peptide 2 (GLP-2) during TPN. The decline was regulated by T1R3 and mGluR5, suggesting a novel negative regulator pathway for IEC proliferation not previously described. Loss of luminal nutrients with TPN administration may widely affect intestinal taste sensing. GLM has previously unrecognized actions on IEC growth and EBF. Restoring luminal sensing via GLM could be a strategy for patients on TPN.

  15. Memantine reduces consumption of highly palatable food in a rat model of binge eating

    PubMed Central

    Kos, Tomasz; Zhang, Yulei; Bisaga, Adam

    2010-01-01

    Excessive consumption of highly palatable food has been linked to the development of eating disorders and obesity, and can be modeled in non-food-deprived rats by offering them a limited (2-h daily) access to an optional dietary fat. Since the glutamatergic system has recently emerged as a viable target for binge-eating medication development, we compared the effects of subchronic treatment with glutamatergic receptor antagonists to the effects of a reference appetite-suppressing agent sibutramine on highly palatable food (lard) and normal chow intake. In three separate experiments, the consumption of a standard laboratory chow and lard were measured during 12 days of medication treatment and for 6 days afterwards. Generalized estimating equations analysis demonstrated that sibutramine (7.5 mg/kg, PO) significantly decreased lard consumption, with a concurrent increase in chow consumption. Sibutramine effects disappeared after treatment discontinuation. The NMDA receptor antagonist memantine (5 mg/kg, IP) significantly decreased lard consumption and increased chow consumption, comparable to effects of sibutramine; however, memantine’s effects persisted after treatment discontinuation. The effects of the mGluR5 antagonist MTEP (7.5 mg/kg, IP) on food consumption were in the same direction as seen with memantine, but the observed differences were not significant. In an additional control experiment, sibutramine and memantine reduced unlimited (24 h) chow intake during the treatment phase. Present results provide evidence that glutamatergic neurotransmission might be involved in the regulation of excessive consumption of highly palatable foods, and suggest that NMDA receptor may be an attractive target for developing obesity and disordered eating pharmacotherapies. PMID:20571841

  16. Estimating Summer Nutrient Concentrations in Northeastern Lakes from SPARROW Load Predictions and Modeled Lake Depth and Volume

    PubMed Central

    Milstead, W. Bryan; Hollister, Jeffrey W.; Moore, Richard B.; Walker, Henry A.

    2013-01-01

    Global nutrient cycles have been altered by the use of fossil fuels and fertilizers resulting in increases in nutrient loads to aquatic systems. In the United States, excess nutrients have been repeatedly reported as the primary cause of lake water quality impairments. Setting nutrient criteria that are protective of a lakes ecological condition is one common solution; however, the data required to do this are not always easily available. A useful solution for this is to combine available field data (i.e., The United States Environmental Protection Agency (USEPA) National Lake Assessment (NLA)) with average annual nutrient load models (i.e., USGS SPARROW model) to estimate summer concentrations across a large number of lakes. In this paper we use this combined approach and compare the observed total nitrogen (TN) and total phosphorus (TN) concentrations in Northeastern lakes from the 2007 National Lake Assessment to those predicted by the Northeast SPARROW model. We successfully adjusted the SPARROW predictions to the NLA observations with the use of Vollenweider equations, simple input-output models that predict nutrient concentrations in lakes based on nutrient loads and hydraulic residence time. This allows us to better predict summer concentrations of TN and TP in Northeastern lakes and ponds. On average we improved our predicted concentrations of TN and TP with Vollenweider models by 18.7% for nitrogen and 19.0% for phosphorus. These improved predictions are being used in other studies to model ecosystem services (e.g., aesthetics) and dis-services (e.g. cyanobacterial blooms) for ~18,000 lakes in the Northeastern United States. PMID:24260579

  17. Estimating summer nutrient concentrations in Northeastern lakes from SPARROW load predictions and modeled lake depth and volume.

    PubMed

    Milstead, W Bryan; Hollister, Jeffrey W; Moore, Richard B; Walker, Henry A

    2013-01-01

    Global nutrient cycles have been altered by the use of fossil fuels and fertilizers resulting in increases in nutrient loads to aquatic systems. In the United States, excess nutrients have been repeatedly reported as the primary cause of lake water quality impairments. Setting nutrient criteria that are protective of a lakes ecological condition is one common solution; however, the data required to do this are not always easily available. A useful solution for this is to combine available field data (i.e., The United States Environmental Protection Agency (USEPA) National Lake Assessment (NLA)) with average annual nutrient load models (i.e., USGS SPARROW model) to estimate summer concentrations across a large number of lakes. In this paper we use this combined approach and compare the observed total nitrogen (TN) and total phosphorus (TN) concentrations in Northeastern lakes from the 2007 National Lake Assessment to those predicted by the Northeast SPARROW model. We successfully adjusted the SPARROW predictions to the NLA observations with the use of Vollenweider equations, simple input-output models that predict nutrient concentrations in lakes based on nutrient loads and hydraulic residence time. This allows us to better predict summer concentrations of TN and TP in Northeastern lakes and ponds. On average we improved our predicted concentrations of TN and TP with Vollenweider models by 18.7% for nitrogen and 19.0% for phosphorus. These improved predictions are being used in other studies to model ecosystem services (e.g., aesthetics) and dis-services (e.g. cyanobacterial blooms) for ~18,000 lakes in the Northeastern United States.

  18. Cooked oatmeal consumption is associated with better diet quality, better nutrient intakes, and reduced risk for central adiposity and obesity in children 2–18 years: NHANES 2001–2010

    PubMed Central

    O'Neil, Carol E.; Nicklas, Theresa A.; Fulgoni, Victor L.; DiRienzo, Maureen A.

    2015-01-01

    Background None of the studies of whole grains that have looked either at diet or weight/adiposity measures have focused exclusively on oatmeal. Objective The objective of this study was to assess the association between oatmeal consumption and nutrient intake, diet quality, and weight/adiposity of children aged 2–18. Design A nationally representative sample of children aged 2–18 (N=14,690) participating in National Health and Nutrition Examination Survey 2001–2010 was used. Intake was determined from a single 24-h dietary recall. Diet quality was measured using the Healthy Eating Index-2010 (HEI-2010). Covariate-adjusted regression analyses, using appropriate sample weights, were used to determine differences between oatmeal consumers and non-consumers for demographics, nutrient intakes, diet quality, and weight/adiposity measures (p<0.01). Logistic regression was performed to calculate odds ratios for weight measures and obesity (p<0.05). Results Compared to non-consumers, oatmeal consumers were more likely to be younger and less likely to be smokers. Consumers had higher intakes of dietary fiber, vitamin A, thiamin, riboflavin, calcium, phosphorus, magnesium, iron, copper, and potassium, and significantly lower intakes of total, monounsaturated and saturated fatty acids, cholesterol, and sodium. Oatmeal consumers had higher dietary quality scores attributable to higher intakes of whole grains and lower intakes of refined grains and empty calories. Children consuming oatmeal were at lower risk for having central adiposity and being obese. Conclusions Consumption of oatmeal by children was associated with better nutrient intake, diet quality, and reduced risk for central adiposity and obesity and should be encouraged as part of an overall healthful diet. PMID:26022379

  19. Global solutions to a chemotaxis model with consumption of chemoattractant

    NASA Astrophysics Data System (ADS)

    Wang, Liangchen; Mu, Chunlai; Hu, Xuegang

    2016-08-01

    This paper is devoted to the following chemotaxis system u_t=nabla\\cdot(D(u)nabla u)-nabla\\cdot(S(u)nabla v),quad &xin Ω,quad t>0, v_t=Δ v-uv,quad &xinΩ,quad t>0, under homogeneous Neumann boundary conditions in a smooth bounded domain {Ωsubset {R}^n} ({n≥2}), not necessarily being convex. There are some constants {c_D > 0}, {c_S > 0}, {min{R}} and {qin{R}} such that D(u) ≥ c_D(u+1)^{m-1} quad{and} quad S(u)≤ c_S(u+1)^{q-1}quad for all u≥0. If {q < m+n+2/2n}, it is shown that the model possesses a unique global classical solution which is uniformly bounded; if {q < m/2+n+2/2n}, the global existence of solution is established.

  20. Multiple soil nutrient competition between plants, microbes, and mineral surfaces: model development, parameterization, and example applications in several tropical forests

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    Soil is a complex system where biotic (e.g., plant roots, micro-organisms) and abiotic (e.g., mineral surfaces) consumers compete for resources necessary for life (e.g., nitrogen, phosphorus). This competition is ecologically significant, since it regulates the dynamics of soil nutrients and controls aboveground plant productivity. Here we develop, calibrate, and test a nutrient competition model that accounts for multiple soil nutrients interacting with multiple biotic and abiotic consumers. As applied here for tropical forests, the Nutrient COMpetition model (N-COM) includes three primary soil nutrients (NH4+, NO3-, and POx (representing the sum of PO43-, HPO42-, and H2PO4-)) and five potential competitors (plant roots, decomposing microbes, nitrifiers, denitrifiers, and mineral surfaces). The competition is formulated with a quasi-steady-state chemical equilibrium approximation to account for substrate (multiple substrates share one consumer) and consumer (multiple consumers compete for one substrate) effects. N-COM successfully reproduced observed soil heterotrophic respiration, N2O emissions, free phosphorus, sorbed phosphorus, and free NH4+ at a tropical forest site (Tapajos). The overall model posterior uncertainty was moderately well constrained. Our sensitivity analysis revealed that soil nutrient competition was primarily regulated by consumer-substrate affinity rather than environmental factors such as soil temperature or soil moisture. Our results imply that the competitiveness (from most to least competitive) followed this order: (1) for NH4+, nitrifiers ~ decomposing microbes > plant roots, (2) for NO3-, denitrifiers ~ decomposing microbes > plant roots, (3) for POx, mineral surfaces > decomposing microbes ~ plant roots. Although smaller, plant relative competitiveness is of the same order of magnitude as microbes. We then applied the N-COM model to analyze field nitrogen and phosphorus perturbation experiments in two tropical forest sites (in Hawaii

  1. Modeling changes in red spruce carbon balance and allocation in response to interacting ozone and nutrient stresses.

    PubMed

    Weinstein, David A.; Beloin, Ronald M.; Yanai, Ruth D.

    1991-01-01

    The simulation model TREGRO was developed to analyze the response of red spruce saplings to multiple stresses, such as drought, nutrient deficiency, and exposure to pollutants. The model provides a method of identifying changes in structural and non-structural carbon resources in the tree that may become measurable only after many years of exposure. The model is based on the assumption that the ability of plants to take up and use carbon, water, and nutrients depends on the interrelationships in availability among the three resources. Consequently, the model simulates the simultaneous cycling of these resources. In the model, the tree is divided into the following compartments: a canopy of leaves grouped by age class, branches, stem, and coarse and fine roots in a number of soil horizons. In each of these compartments we track three carbon pools: living structure, dead structure or wood, and total non-structural carbohydrate. The model calculates the photosynthesis of an entire red spruce tree each hour as a function of ambient environmental conditions and the availability of light, water, and nutrients; the daily redistribution of carbon throughout the plant; and the loss of carbon by respiration and senescence. To accomplish this task, the model tracks the flow of carbon dioxide to the sites of fixation within the leaves, the availability of light in the canopy, water and nutrient resources in each of three soil horizons, and the amounts of these resources taken up by the tree. Soil and plant water potentials, photosynthesis, and leaf respiration are simulated on an hourly timestep; nutrient uptake, allocation and growth are computed on a daily timestep. Through a set of example simulations, we demonstrate how the model can be used to examine the mechanisms by which plants respond to stresses experienced alone and in combination. The model was used to predict the growth decrease and the shifting pattern of carbon allocation expected for an isolated tree exposed

  2. Biological nutrient removal in a full-scale SBR treating piggery wastewater: results and modelling.

    PubMed

    Tilche, A; Bortone, G; Malaspina, F; Piccinini, S; Stante, L

    2001-01-01

    Research activities carried out at ENEA during the last few years allowed development of a Sequencing Batch Reactor (SBR) that is able to remove biologically organic waste, nitrogen and phosphorus and that showed to be particularly suited to obtain low effluent nutrient concentrations even starting from concentrated wastes. This plant, in more than one year of operation, is quite steadily obtaining more than 98% removal of nitrogen, phosphorus and COD. On the basis of the experimental results, a simulation model has been built and calibrated. The model showed the potential to be used for forecasting the behaviour of the process, being able to reproduce a process imbalance that followed the tentative reduction of aeration time.

  3. Application of the SPARROW model to assess surface-water nutrient conditions and sources in the United States Pacific Northwest

    USGS Publications Warehouse

    Wise, Daniel R.; Johnson, Henry M.

    2013-01-01

    The watershed model SPARROW (Spatially Referenced Regressions on Watershed attributes) was used to estimate mean annual surface-water nutrient conditions (total nitrogen and total phosphorus) and to identify important nutrient sources in catchments of the Pacific Northwest region of the United States for 2002. Model-estimated nutrient yields were generally higher in catchments on the wetter, western side of the Cascade Range than in catchments on the drier, eastern side. The largest source of locally generated total nitrogen stream load in most catchments was runoff from forestland, whereas the largest source of locally generated total phosphorus stream load in most catchments was either geologic material or livestock manure (primarily from grazing livestock). However, the highest total nitrogen and total phosphorus yields were predicted in the relatively small number of catchments where urban sources were the largest contributor to local stream load. Two examples are presented that show how SPARROW results can be applied to large rivers—the relative contribution of different nutrient sources to the total nitrogen load in the Willamette River and the total phosphorus load in the Snake River. The results from this study provided an understanding of the regional patterns in surface-water nutrient conditions and should be useful to researchers and water-quality managers performing local nutrient assessments.

  4. ANIMO 3.5: User`s guide for the ANIMO version 3.5 nutrient leaching model

    SciTech Connect

    Kroes, J.; Roelsma, J.

    1998-12-31

    This document presents a description of the use of the nutrient leaching model ANIMO (Agricultural Nutrient Model) version 3.5 with special emphasis for input instructions. Each input parameter is characterized by its unit, range, data type, variable name in computer code and symbol in theoretical description, Program outputs and program execution are briefly given. An example is presented with values of input parameters and model results. A technical program description is given as a brief description of program structure, nomenclature, and source code.

  5. The impact of dairy and sweetened beverage consumption on diet quality, nutrient intake, and weight of a multi-ethnic population of Head Start mothers

    USDA-ARS?s Scientific Manuscript database

    To assess the impact of milk and sweetened beverage (SwB) intake on diet and weight in Head Start mothers, three 24-hour dietary recalls were collected on 609 Black (43%), Hispanic (33%), or White (24%) women in AL and TX. Women were divided into four beverage consumption groups: low milk/high SwB, ...

  6. Improvement in fruit and vegetable consumption associated with more favorable energy density and nutrient and food group intake, but not kilocalories

    USDA-ARS?s Scientific Manuscript database

    Children generally do not consume adequate amounts of fruits and vegetables (F/V). Eating more F/V can improve energy density and overall diet quality. Our aim was to investigate whether improvements in F/V consumption were associated with improvements in energy density, total calories, and dietary ...

  7. Modeling of rotary cement kilns: Applications to reduction in energy consumption

    SciTech Connect

    Mujumdar, K.S.; Arora, A.; Ranade, V.V.

    2006-03-29

    We discuss and evaluate possible ways of reducing energy consumption in rotary cement kilns. A comprehensive one-dimensional model was developed to simulate complex processes occurring in rotary cement kilns. A modeling strategy comprising three submodels, viz. a model for simulating the variation of bed height in the kiln, a model for simulating reactions and heat transfer in the bed region, and a model for simulating coal combustion and heat transfer in the freeboard region, was developed. Melting and formation of coating within the kiln were accounted for. Combustion of coal in the freeboard region was modeled by accounting for devolatilization, finite-rate gas-phase combustion, and char reaction. The simulated results were validated with the available data from three industrial kilns. The model was then used to understand the influence of various design and operating parameters on kiln performance. Several ways of reducing energy consumption in kilns were then computationally investigated. The model was also used to propose and to evaluate a practical solution of using a secondary shell to reduce energy consumption in rotary cement kilns. Simulation results indicate that varying kiln operating variables, viz. solid flow rate or RPM, can result only in small changes in kiln energetics. Use of a secondary shell over the kiln and energy recovery by passing air through the annular gap between the two appears to be a promising way to achieve significant energy savings. The developed model and the presented results will be useful for enhancing the performance of rotary cement kilns.

  8. A Coupled Ocean General Circulation, Biogeochemical, and Radiative Model of the Global Oceans: Seasonal Distributions of Ocean Chlorophyll and Nutrients

    NASA Technical Reports Server (NTRS)

    Gregg, Watson W.; Busalacchi, Antonio (Technical Monitor)

    2000-01-01

    A coupled ocean general circulation, biogeochemical, and radiative model was constructed to evaluate and understand the nature of seasonal variability of chlorophyll and nutrients in the global oceans. Biogeochemical processes in the model are determined from the influences of circulation and turbulence dynamics, irradiance availability. and the interactions among three functional phytoplankton groups (diatoms. chlorophytes, and picoplankton) and three nutrients (nitrate, ammonium, and silicate). Basin scale (greater than 1000 km) model chlorophyll results are in overall agreement with CZCS pigments in many global regions. Seasonal variability observed in the CZCS is also represented in the model. Synoptic scale (100-1000 km) comparisons of imagery are generally in conformance although occasional departures are apparent. Model nitrate distributions agree with in situ data, including seasonal dynamics, except for the equatorial Atlantic. The overall agreement of the model with satellite and in situ data sources indicates that the model dynamics offer a reasonably realistic simulation of phytoplankton and nutrient dynamics on synoptic scales. This is especially true given that initial conditions are homogenous chlorophyll fields. The success of the model in producing a reasonable representation of chlorophyll and nutrient distributions and seasonal variability in the global oceans is attributed to the application of a generalized, processes-driven approach as opposed to regional parameterization and the existence of multiple phytoplankton groups with different physiological and physical properties. These factors enable the model to simultaneously represent many aspects of the great diversity of physical, biological, chemical, and radiative environments encountered in the global oceans.

  9. MODELING NITROGEN-CARBON CYCLING AND OXYGEN CONSUMPTION IN BOTTOM SEDIMENTS

    EPA Science Inventory

    A model framework is presented for simulating nitrogen and carbon cycling at the sediment–water interface, and predicting oxygen consumption by oxidation reactions inside the sediments. Based on conservation of mass and invoking simplifying assumptions, a coupled system of diffus...

  10. Alcohol advertising, consumption and abuse: a covariance-structural modelling look at Strickland's data.

    PubMed

    Adlaf, E M; Kohn, P M

    1989-07-01

    Re-analysis employing covariance-structural models was conducted on Strickland's (1983) survey data on 772 drinking students from Grades 7, 9 and 11. These data bear on the relations among alcohol consumption, alcohol abuse, association with drinking peers and exposure to televised alcohol advertising. Whereas Strickland used a just-identified model which, therefore, could not be tested for goodness of fit, our re-analysis tested several alternative models, which could be contradicted by the data. One model did fit his data particularly well. Its major implications are as follows: (1) Symptomatic consumption, negative consequences and self-rated severity of alcohol-related problems apparently reflect a common underlying factor, namely alcohol abuse. (2) Use of alcohol to relieve distress and frequency of intoxication, however, appear not to reflect abuse, although frequent intoxication contributes substantially to it. (3). Alcohol advertising affects consumption directly and abuse indirectly, although peer association has far greater impact on both consumption and abuse. These findings are interpreted as lending little support to further restrictions on advertising.

  11. MODELING NITROGEN-CARBON CYCLING AND OXYGEN CONSUMPTION IN BOTTOM SEDIMENTS

    EPA Science Inventory

    A model framework is presented for simulating nitrogen and carbon cycling at the sediment–water interface, and predicting oxygen consumption by oxidation reactions inside the sediments. Based on conservation of mass and invoking simplifying assumptions, a coupled system of diffus...

  12. Estimating catchment nutrient flow with the HBV-NP model: sensitivity to input data.

    PubMed

    Andersson, Lotta; Rosberg, Jörgen; Pers, B Charlotta; Olsson, Jonas; Arheimer, Berit

    2005-11-01

    The dynamic catchment model HBV-N has been further developed by adding routines for phosphorus transport and is now called the HBV-NP model. The model was shown to satisfactorily simulate nutrient dynamics in the Rönneå catchment (1,900 km2). Its sensitivity to input data was tested, and results demonstrated the increased sensitivity to the selection of input data on a subcatchment scale when compared with the catchment scale. Selection of soil and land use databases was found to be critical in some subcatchments but did not have a significant impact on a catchment scale. Although acceptable on a catchment scale, using templates and generalization, with regards to emissions from point sources and rural households, significantly decreased model performance in certain subcatchments when compared with using more detailed local information. A division into 64 subcatchments resulted in similar model performance at the catchment outlet when compared with a lumped approach. Adjusting the imported matrixes of the regional leaching of nitrogen, from agricultural land, against mean subcatchment water percolation did not have a significant impact on the model performance.

  13. Kinetic modelling of starch and lipid formation during mixotrophic, nutrient-limited microalgal growth.

    PubMed

    Figueroa-Torres, Gonzalo M; Pittman, Jon K; Theodoropoulos, Constantinos

    2017-10-01

    Microalgal starch and lipids, carbon-based storage molecules, are useful as potential biofuel feedstocks. In this work, cultivation strategies maximising starch and lipid formation were established by developing a multi-parameter kinetic model describing microalgal growth as well as starch and lipid formation, in conjunction with laboratory-scale experiments. Growth dynamics are driven by nitrogen-limited mixotrophic conditions, known to increase cellular starch and lipid contents whilst enhancing biomass growth. Model parameters were computed by fitting model outputs to a range of experimental datasets from batch cultures of Chlamydomonas reinhardtii. Predictive capabilities of the model were established against different experimental data. The model was subsequently used to compute optimal nutrient-based cultivation strategies in terms of initial nitrogen and carbon concentrations. Model-based optimal strategies yielded a significant increase of 261% for starch (0.065gCL(-1)) and 66% for lipid (0.08gCL(-1)) production compared to base-case conditions (0.018gCL(-1) starch, 0.048gCL(-1) lipids). Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Data-driven behavioural modelling of residential water consumption to inform water demand management strategies

    NASA Astrophysics Data System (ADS)

    Giuliani, Matteo; Cominola, Andrea; Alshaf, Ahmad; Castelletti, Andrea; Anda, Martin

    2016-04-01

    The continuous expansion of urban areas worldwide is expected to highly increase residential water demand over the next few years, ultimately challenging the distribution and supply of drinking water. Several studies have recently demonstrated that actions focused only on the water supply side of the problem (e.g., augmenting existing water supply infrastructure) will likely fail to meet future demands, thus calling for the concurrent deployment of effective water demand management strategies (WDMS) to pursue water savings and conservation. However, to be effective WDMS do require a substantial understanding of water consumers' behaviors and consumption patterns at different spatial and temporal resolutions. Retrieving information on users' behaviors, as well as their explanatory and/or causal factors, is key to spot potential areas for targeting water saving efforts and to design user-tailored WDMS, such as education campaigns and personalized recommendations. In this work, we contribute a data-driven approach to identify household water users' consumption behavioural profiles and model their water use habits. State-of-the-art clustering methods are coupled with big data machine learning techniques with the aim of extracting dominant behaviors from a set of water consumption data collected at the household scale. This allows identifying heterogeneous groups of consumers from the studied sample and characterizing them with respect to several consumption features. Our approach is validated onto a real-world household water consumption dataset associated with a variety of demographic and psychographic user data and household attributes, collected in nine towns of the Pilbara and Kimberley Regions of Western Australia. Results show the effectiveness of the proposed method in capturing the influence of candidate determinants on residential water consumption profiles and in attaining sufficiently accurate predictions of users' consumption behaviors, ultimately providing

  15. A stoichiometric producer-grazer model incorporating the effects of excess food-nutrient content on consumer dynamics.

    PubMed

    Peace, Angela; Zhao, Yuqin; Loladze, Irakli; Elser, James J; Kuang, Yang

    2013-08-01

    There has been important progress in understanding ecological dynamics through the development of the theory of ecological stoichiometry. For example, modeling under this framework allows food quality to affect consumer dynamics. While the effects of nutrient deficiency on consumer growth are well understood, recent discoveries in ecological stoichiometry suggest that consumer dynamics are not only affected by insufficient food nutrient content (low phosphorus (P): carbon (C) ratio) but also by excess food nutrient content (high P:C). This phenomenon is known as the stoichiometric knife edge, in which animal growth is reduced not only by food with low P content but also by food with high P content, and needs to be incorporated into mathematical models. Here we present a Lotka-Volterra type model to investigate the growth response of Daphnia to algae of varying P:C ratios capturing the mechanism of the stoichiometric knife edge.

  16. Modeling nutrient and plankton processes in the California coastal transition zone. 1. A time- and depth-dependent model

    NASA Astrophysics Data System (ADS)

    Moisan, J. R.; Hofmann, E. E.

    1996-10-01

    A time- and depth-dependent, physical-bio-optical model was developed for the California coastal transition zone (CTZ) with the overall objective of understanding and quantifying the processes that contribute to the vertical and temporal development of nutrient and plankton distributions in the CTZ. The model food web components included silicate, nitrate, ammonium, two phytoplankton size fractions, copepods, doliolids, euphausiids, and a detritus pool. The wavelength-dependent subsurface irradiance field was attenuated by seawater and phytoplankton pigments. The one-dimensional (1-D) model adequately simulated the development and maintenance of a subsurface chlorophyll maximum in different regions within the CTZ. An analysis of the individual terms in the model governing equations revealed that phytoplankton in situ growth was primarily responsible for the creation and maintenance of the subsurface chlorophyll maximum at both coastal and oceanic regions in the CTZ. The depth to which the maximum in situ growth occurred was controlled by the combined effect of light and nutrient limitation. Also, the simulated bio-optical fields demonstrated the effect of nonlinear couplings between food web components and the subsurface irradiance field on vertical biological distributions. In particular, the e-folding scale of the subsurface photosynthetically available radiation (PAR) was influenced by the level of zooplankton grazing.

  17. Oxygen consumption rates by different oenological tannins in a model wine solution.

    PubMed

    Pascual, Olga; Vignault, Adeline; Gombau, Jordi; Navarro, Maria; Gómez-Alonso, Sergio; García-Romero, Esteban; Canals, Joan Miquel; Hermosín-Gutíerrez, Isidro; Teissedre, Pierre-Louis; Zamora, Fernando

    2017-11-01

    The kinetics of oxygen consumption by different oenological tannins were measured in a model wine solution using the non-invasive method based on luminiscence. The results indicate that the oxygen consumption rate follows second-order kinetics depending on tannin and oxygen concentrations. They also confirm that the oxygen consumption rate is influenced by temperature in accordance with Arrhenius law. The indications are that ellagitannins are the fastest oxygen consumers of the different oenological tannins, followed in decreasing order by quebracho tannins, skin tannins, seed tannins and finally gallotannins. This methodology can therefore be proposed as an index for determining the effectiveness of different commercial tannins in protecting wines against oxidation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Modeling energy consumption in membrane bioreactors for wastewater treatment in north Africa.

    PubMed

    Skouterisl, George; Arnot, Tom C; Jraou, Mouna; Feki, Firas; Sayadi, Sami

    2014-03-01

    Two pilot-scale membrane bioreactors were operated alongside a full-sized activated sludge plant in Tunisia in order to compare specific energy demand and treated water quality. Energy consumption rates were measured for the complete membrane bioreactor systems and for their different components. Specific energy demand was measured for the systems and compared with the activated sludge plant, which operated at around 3 kWh m(-3). A model was developed for each membrane bioreactor based on both dynamic and steady-state mass balances, microbial kinetics and stoichiometry, and energy balance. Energy consumption was evaluated as a function of mixed-liquor suspended solids concentration, net permeate fluxes, and the resultant treated water quality. This work demonstrates the potential for using membrane bioreactors in decentralised domestic water treatment in North Africa, at energy consumption levels similar or lower than conventional activated sludge systems, with the added benefit of producing treated water suitable for unrestricted crop irrigation.

  19. Benchmarking biological nutrient removal in wastewater treatment plants: influence of mathematical model assumptions.

    PubMed

    Flores-Alsina, Xavier; Gernaey, Krist V; Jeppsson, Ulf

    2012-01-01

    This paper examines the effect of different model assumptions when describing biological nutrient removal (BNR) by the activated sludge models (ASM) 1, 2d & 3. The performance of a nitrogen removal (WWTP1) and a combined nitrogen and phosphorus removal (WWTP2) benchmark wastewater treatment plant was compared for a series of model assumptions. Three different model approaches describing BNR are considered. In the reference case, the original model implementations are used to simulate WWTP1 (ASM1 & 3) and WWTP2 (ASM2d). The second set of models includes a reactive settler, which extends the description of the non-reactive TSS sedimentation and transport in the reference case with the full set of ASM processes. Finally, the third set of models is based on including electron acceptor dependency of biomass decay rates for ASM1 (WWTP1) and ASM2d (WWTP2). The results show that incorporation of a reactive settler: (1) increases the hydrolysis of particulates; (2) increases the overall plant's denitrification efficiency by reducing the S(NOx) concentration at the bottom of the clarifier; (3) increases the oxidation of COD compounds; (4) increases X(OHO) and X(ANO) decay; and, finally, (5) increases the growth of X(PAO) and formation of X(PHA,Stor) for ASM2d, which has a major impact on the whole P removal system. Introduction of electron acceptor dependent decay leads to a substantial increase of the concentration of X(ANO), X(OHO) and X(PAO) in the bottom of the clarifier. The paper ends with a critical discussion of the influence of the different model assumptions, and emphasizes the need for a model user to understand the significant differences in simulation results that are obtained when applying different combinations of 'standard' models.

  20. Is the stokeslet model sufficient for finding nutrient uptake of microscopic suspension feeders?

    NASA Astrophysics Data System (ADS)

    Lutton, Alexander T.; Pepper, Rachel E.

    2016-11-01

    Microscopic sessile suspension feeders are part of many aquatic ecosystems. They are single-celled, vary in size from a few to about 100 microns in length, live attached to substrates, and serve important ecological roles as both food for larger organisms and consumers of bacteria and other small particles. These organisms create currents in order to bring food toward them. Understanding these currents may allow us not only deeper insight into the ecology of aquatic ecosystems, but also may enable innovation in water treatment. Simulations of the feeding currents of these organisms typically use a simple model that places a stokeslet above an infinite plane boundary representing the surface of attachment. This model produces a useful approximation for the flow field of the organism, but may be of limited accuracy when the organism is near the boundary. We create a different model composed of a stokeslet and a potential dipole, which form a sphere. This sphere has a sin(θ) tangential velocity boundary condition, accounting for the cell body. Using nutrient flux to the organism as our metric, we investigate the discrepancy between the spherical and stokeslet models in order to determine the efficacy of the stokeslet model as an approximation of single-celled suspension feeders.

  1. Regional Measurement and Modeling of Floodplain Wetland Nutrient and Sediment Fluxes: The Chesapeake Watershed

    NASA Astrophysics Data System (ADS)

    Noe, G. B.; Hupp, C. R.; Schenk, E.; Claggett, P.

    2016-12-01

    Wetlands play a key role in watershed nutrient and sediment dynamics and stream water quality improvement. The USGS Chesapeake Floodplain Network is measuring deposition and erosion of sediment and associated nutrients throughout the Chesapeake non-tidal watershed, with the goal of identifying predictors of reach-scale material fluxes. Forty-three research sites across the Valley and Ridge (V&R), Piedmont (PD), and Coastal Plain (CP) physiographic provinces (PP) were sampled to measure bank erosion and floodplain deposition over long time scales using dendrogeomorphic methods, sediment characteristics, and reach geomorphology. Sites were located on reaches of streams and rivers of varying watershed size and land use. Long-term floodplain accretion and bank erosion rates (cm/y) did not significantly differ among PP. Reach-scale fluxes of sediment (kg/m/y) and its component mineral sediment fluxes from floodplain deposition, bank erosion, and the reach net balance (floodplain - bank) did not differ among PP despite increasing floodplain width from V&R to PD to CP. River reaches in the CP were significantly greater net balance sinks of organic sediment, C, N, and P than those in PD or V&R. Variability in fluxes among reaches could be explained by a combination of GIS derived reach-scale geomorphology and watershed-scale characteristics, with relatively high accuracy (bank and floodplain sediment flux: R2=0.37 and 0.70, respectively). These models are being used to predict bank and floodplain sediment, N, P, and C fluxes for every stream reach in the 167,000 km2 Chesapeake watershed. These predictions of wetland effects on downstream water quality, along with estimates of upland erosion and river loads, will then be integrated to generate watershed material budgets throughout the Chesapeake. Our findings suggest a promising approach to combine dendrogeomorphology with GIS analyses to measure and model the effects of floodplain wetlands on downstream water quality.

  2. Modeling Nutrients Export in responses to Land Use Changes in Mississippi River Basin during 1901-2008

    NASA Astrophysics Data System (ADS)

    Yang, Q.; Tian, H.; Liu, M.; Li, X.; Chen, G.

    2011-12-01

    Land use change is a serious issue that human society is facing. Land conversions could significantly change land surface characteristics and radically impact nutrient leaching from land to river systems. In the past one hundred years, the Mississippi river basin has experienced increasing land conversions. Crop land and impervious surface area in this area has increased greatly. To understand the consequence of these changes on nutrient export from the river basin to the ocean, a hydrological-biochemical model -Dynamic Land Ecosystem Model (DLEM)-was employed to simulate carbon(C), nitrogen (N) and phosphorus (P) export from the river basin. A set of gridded (5'×5'), time series land use data from 1901 to 2008 were organized as input forcing for model simulation. To eliminate climate variation influence, climate data were kept constant using the data of 1900. Results of this study demonstrate that major crop land expansion in the west part of the river basin has greatly altered nutrients export in the region. Nutrients export has increased significantly as a result of land use changes. The spatial and temporal characteristic of nutrients leaching in response to land use changes has also been analyzed and discussed.

  3. Experimental manipulation of breakfast in normal and overweight/obese participants is associated with changes to nutrient and energy intake consumption patterns.

    PubMed

    Reeves, Sue; Huber, Jörg W; Halsey, Lewis G; Horabady-Farahani, Yasmin; Ijadi, Mehrnaz; Smith, Tina

    2014-06-22

    The effect of breakfast and breakfast omission on daily food intake in normal and overweight participants was investigated. 37 participants were recruited for this experimental study and assigned to one of four groups on the basis of their body mass index (BMI) (normal weight BMI <25 kg/m(2) or overweight/obese BMI >25 kg/m(2)) and breakfast habits (breakfast eater or breakfast omitter). All participants were requested to eat breakfast for an entire week, and then following a washout period, omit breakfast for an entire week, or vice versa. Seven-day food diaries reporting what was consumed and the timing of consumption were completed for each breakfast condition. Overall more energy was consumed during the breakfast than the no breakfast week. The present study revealed significant effects of timing on energy intakes; more energy was consumed during the afternoon in the no breakfast week compared to the breakfast week. Overweight participants consumed greater amounts of energy than normal weight participants in the early evening. Breakfast omitters consumed more than did breakfast eaters later in the evening. All groups consumed significantly less energy, carbohydrate and fibre in the no breakfast week; however, overweight participants increased their sugar intakes. Consumption of the micronutrients iron and folate was reduced in the no breakfast week. The findings highlight that the timing of food intake and habitual breakfast eating behaviour are important factors when investigating why breakfast consumption may be associated with BMI. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Modelling water discharges and nutrient inputs into a Mediterranean lagoon (Thau, France). Impact on phytoplankton production.

    NASA Astrophysics Data System (ADS)

    Plus, M.; La Jeunesse, I.; Bouraoui, F.

    2003-04-01

    The lagoon of Thau (French Mediterranean coast), is a large (75 km2) and rather deep coastal lagoon (mean depth 4 m), connected to the sea by its two extremities (residence time: about 3 months). Besides its ecological interest as a breeding and transit zone for some sea fish species, the lagoon has a notable economic importance due to shellfish cultivation with an annual oyster production of about 15 000 tons. This considerable production depends to a large extent on nutrient inputs into the ecosystem, supplied mainly from fresh water. The catchment area is about 280 Km2, including agriculture (mainly vineyards), industrial activities and urban waste. Due to the low water renewal and to the intensive shellfish farming activities the Thau lagoon is particularly sensitive to any modification in watershed outputs. The aim of this study is to assess the impact of watershed outputs on the lagoon ecosystem. The Soil and Water Assessment Tool (SWAT model) has been applied to the Thau lagoon catchment area in order to simulate water discharges and nutrients (ammonium, nitrate, and phosphates) inputs into the lagoon on a 10 years period (1989-1999). The model has been calibrated and validated using measured data available for the two main rivers of the watershed, representing about 50% of total freshwater inputs. The model predictions compared favourably with the measurements concerning water quantity as well as major water quality determinants (ammonium, nitrate, phosphates, and suspended matter). Then, several scenarios (e. g. changes in agricultural practices) have been run and the simulated results were used as forcing variables in a lagoon ecosystem model, previously developed for Thau. The latter is a three-dimensional model coupling both hydrodynamical and biological processes. The following state variables are simulated in the model biological part: ammonia, nitrates, phytoplankton, zooplankton, detritus, oyster biodeposits and oxygen. In addition to the inputs

  5. Social approval and facilitation in predicting modeling effects in alcohol consumption.

    PubMed

    Caudill, B D; Kong, F H

    2001-01-01

    An important question for alcohol abuse prevention and treatment is whether individuals with high needs for social approval, or those who drink heavily in social contexts, are particularly vulnerable to modeling effects in alcohol consumption. Male and female heavy social drinkers (N=202), as distinguished by these cognitive and situational variables, participated in a multisession dyadic modeling effects study along with a same-sex confederate model who exhibited alternating patterns of heavy and light consumption in an experimental barroom. Subjects with high needs for social approval, and those who tend to drink heavily in social contexts, were particularly vulnerable to imitating directional changes in modeled drinking levels across heavy and light consumption experimental sessions. Additionally, modeling effects were revealed, including reductions in drinking levels, regardless of individual characteristics such as demographics or levels of intoxication achieved on "usual drinking occasions." Findings suggest that individuals exhibiting high needs for social approval, and those who tend to drink heavily in social contexts, may benefit from (1) befriending lower risk models and (2) prevention and/or intervention efforts to reduce risk for substance use by reducing excessive needs for social approval and/or reducing exposure to social contexts where heavy drinking and related risk behavior is normative.

  6. Modeling controlled nutrient release from polymer coated fertilizers: diffusion release from single granules.

    PubMed

    Shaviv, Avi; Raban, Smadar; Zaidel, Elina

    2003-05-15

    A comprehensive model describing the complex and "non-Fickian" (mathematically nonlinear) nature of the release from single granules of membrane coated, controlled release fertilizers (CRFs) is proposed consisting of three stages: i. a lag period during which water penetrates the coating of the granule dissolving part of the solid fertilizer in it ii. a period of linear release during which water penetration into and release out occur concomitantly while the total volume of the granules remains practically constant; and iii. a period of "decaying release", starting as the concentration inside the granule starts to decrease. A mathematical model was developed based on vapor and nutrient diffusion equations. The model predicts the release stages in terms of measurable geometrical and chemophysical parameters such as the following: the product of granule radius and coating thickness, water and solute permeability, saturation concentration of the fertilizer, and its density. The model successfully predicts the complex and "sigmoidal" pattern of release that is essential for matching plant temporal demand to ensure high agronomic and environmental effectiveness. It also lends itself to more complex statistical formulations which account for the large variability within large populations of coated CRFs and can serve for further improving CRF production and performance.

  7. Modeled diversity effects on microbial ecosystem functions of primary production, nutrient uptake, and remineralization.

    PubMed

    Goebel, Nicole L; Edwards, Christopher A; Follows, Michael J; Zehr, Jonathan P

    2014-01-01

    Ecosystem-wide primary productivity generally increases with primary producer diversity, emphasizing the importance of diversity for ecosystem function. However, most studies that demonstrate this positive relationship have focused on terrestrial and aquatic benthic systems, with little attention to the diverse marine pelagic primary producers that play an important role in regulating global climate. Here we show how phytoplankton biodiversity enhances overall marine ecosystem primary productivity and other ecosystem functions using a self-organizing ecosystem model. Diversity manipulation numerical experiments reveal positive, asymptotically saturating relationships between ecosystem-wide phytoplankton diversity and functions of productivity, nutrient uptake, remineralization, and diversity metrics used to identify mechanisms shaping these relationships. Increase in productivity with increasing diversity improves modeled ecosystem stability and model robustness and leads to productivity rates that exceed expected yields primarily through niche complementarity and facilitative interactions between coexisting phytoplankton types; the composition of traits in assemblages determines the magnitude of complementarity and selection effects. While findings based on these aggregate measures of diversity effects parallel those from the majority of experimental outcomes of terrestrial and benthic biodiversity-ecosystem function studies, we combine analyses of community diversity effects and investigations of the underlying interactions among phytoplankton types to demonstrate how an increase in recycled production of non-diatoms through an increase in new production of diatoms drives this diversity-cosystem function response. We demonstrate the important role that facilitation plays in the modeled marine plankton and how this facilitative interaction could amplify future climate-driven changes in ocean ecosystem productivity.

  8. Modelling of multi-nutrient interactions in growth of the dinoflagellate microalga Protoceratium reticulatum using artificial neural networks.

    PubMed

    López-Rosales, L; Gallardo-Rodríguez, J J; Sánchez-Mirón, A; Contreras-Gómez, A; García-Camacho, F; Molina-Grima, E

    2013-10-01

    This study examines the use of artificial neural networks as predictive tools for the growth of the dinoflagellate microalga Protoceratium reticulatum. Feed-forward back-propagation neural networks (FBN), using Levenberg-Marquardt back-propagation or Bayesian regularization as training functions, offered the best results in terms of representing the nonlinear interactions among all nutrients in a culture medium containing 26 different components. A FBN configuration of 26-14-1 layers was selected. The FBN model was trained using more than 500 culture experiments on a shake flask scale. Garson's algorithm provided a valuable means of evaluating the relative importance of nutrients in terms of microalgal growth. Microelements and vitamins had a significant importance (approximately 70%) in relation to macronutrients (nearly 25%), despite their concentrations in the culture medium being various orders of magnitude smaller. The approach presented here may be useful for modelling multi-nutrient interactions in photobioreactors.

  9. ‘Wired’, yet intoxicated: Modeling binge caffeine and alcohol co-consumption in the mouse

    PubMed Central

    Fritz, Brandon M.; Companion, Michel; Boehm, Stephen L.

    2014-01-01

    Background The combination of highly caffeinated ‘energy drinks’ with alcohol (ethanol) has become popular among young adults and intoxication via such beverages has been associated with an elevated risk for harmful behaviors. However, there are discrepancies in the human literature regarding the effect of caffeine on alcohol intoxication, perhaps due to confounding factors such as personality type, expectancy, and history of exposure. Animal models of co-exposure are resistant to such issues, however, the consequences of voluntary co-consumption have been largely ignored in the animal literature. The primary goal of this work was to characterize a mouse model of binge caffeine and ethanol co-consumption employing the limited-access ‘Drinking-in-the-Dark’ paradigm (DID). Methods Caffeine was added to a 20% alcohol solution via DID. Alcohol/caffeine intake, locomotor behavior, ataxia, anxiety-like behavior, and cognitive function were evaluated as a consequence of co-consumption in adult male C57BL/6J mice. Results Caffeine did not substantially alter binge alcohol intake or resultant BECs, nor did it alter alcohol’s anxiolytic effects on the elevated plus maze or cognitive interfering effects in a novel object recognition task. However, no evidence of alcohol-induced sedation was observed in co-consumption groups that instead demonstrated a highly stimulated state similar to that of caffeine alone. The addition of caffeine was also found to mitigate alcohol-induced ataxia. Conclusions Taken together, our mouse model indicates that binge co-consumption of caffeine and alcohol produces a stimulated, less ataxic and anxious, as well as cognitively altered state; a state that could be of great public health concern. These results appear to resemble the colloquially-identified ‘wide awake drunk’ state that individuals seek via consumption of such beverages. This self-administration model therefore offers the capacity for translationally-valid explorations

  10. "Wired," yet intoxicated: modeling binge caffeine and alcohol co-consumption in the mouse.

    PubMed

    Fritz, Brandon M; Companion, Michel; Boehm, Stephen L

    2014-08-01

    The combination of highly caffeinated "energy drinks" with alcohol (ethanol [EtOH]) has become popular among young adults and intoxication via such beverages has been associated with an elevated risk for harmful behaviors. However, there are discrepancies in the human literature regarding the effect of caffeine on alcohol intoxication, perhaps due to confounding factors such as personality type, expectancy, and history of exposure. Animal models of co-exposure are resistant to such issues; however, the consequences of voluntary co-consumption have been largely ignored in the animal literature. The primary goal of this work was to characterize a mouse model of binge caffeine and EtOH co-consumption employing the limited access "Drinking-in-the-Dark" (DID) paradigm. Caffeine was added to a 20% alcohol solution via DID. Alcohol/caffeine intake, locomotor behavior, ataxia, anxiety-like behavior, and cognitive function were evaluated as a consequence of co-consumption in adult male C57BL/6J mice. Caffeine did not substantially alter binge alcohol intake or resultant blood EtOH concentrations (BECs), nor did it alter alcohol's anxiolytic effects on the elevated plus maze or cognitive-interfering effects in a novel object-recognition task. However, no evidence of alcohol-induced sedation was observed in co-consumption groups that instead demonstrated a highly stimulated state similar to that of caffeine alone. The addition of caffeine was also found to mitigate alcohol-induced ataxia. Taken together, our mouse model indicates that binge co-consumption of caffeine and alcohol produces a stimulated, less ataxic and anxious, as well as cognitively altered state; a state that could be of great public health concern. These results appear to resemble the colloquially identified "wide awake drunk" state that individuals seek via consumption of such beverages. This self-administration model therefore offers the capacity for translationally valid explorations of the

  11. A Preliminary Model of Motivation for Pornography Consumption Among Men Participating in Zoophilic Virtual Environments.

    PubMed

    de Souza Aranha E Silva, Renata Almeida; Baltieri, Danilo Antonio

    2016-01-01

    Although zoophilic blogs and websites attract the attention of zoophiles and others who are curious about this sexual activity, the motivations for consuming this type of pornography are not clear. This study aimed to confirm the factorial validity of the Pornography Consumption Inventory in an online sample of men with sexual interest in animals, and to construct an association model between motivations for pornography consumption and the following psychological variables: depression, sexual impulsiveness, and strength of sexual interest in animals. In this cross-sectional study, we located a website that catered to a network of people with a sexual interest in animals. Subsequently, a questionnaire was made available online to members of this network. Results support the 4-factor model of the Pornography Consumption Inventory. Depression and strength of sexual interest in animals were negatively and positively correlated with the sexual curiosity factor, respectively. Sexual impulsiveness was positively associated with the emotional avoidance, excitement seeking, and sexual pleasure factors. Depression and sexual impulsiveness were positively correlated. Psychological factors can differently motivate the consumption of pornography among men who visit zoophilic blogs and websites. With these preliminary data, we can identify some characteristics of this population.

  12. An Integrated Modeling and Experimental Approach to Study the Influence of Environmental Nutrients on Biofilm Formation of Pseudomonas aeruginosa

    PubMed Central

    Xu, Zhaobin; Islam, Sabina; Wood, Thomas K.; Huang, Zuyi

    2015-01-01

    The availability of nutrient components in the environment was identified as a critical regulator of virulence and biofilm formation in Pseudomonas aeruginosa. This work proposes the first systems-biology approach to quantify microbial biofilm formation upon the change of nutrient availability in the environment. Specifically, the change of fluxes of metabolic reactions that were positively associated with P. aeruginosa biofilm formation was used to monitor the trend for P. aeruginosa to form a biofilm. The uptake rates of nutrient components were changed according to the change of the nutrient availability. We found that adding each of the eleven amino acids (Arg, Tyr, Phe, His, Iso, Orn, Pro, Glu, Leu, Val, and Asp) to minimal medium promoted P. aeruginosa biofilm formation. Both modeling and experimental approaches were further developed to quantify P. aeruginosa biofilm formation for four different availability levels for each of the three ions that include ferrous ions, sulfate, and phosphate. The developed modeling approach correctly predicted the amount of biofilm formation. By comparing reaction flux change upon the change of nutrient concentrations, metabolic reactions used by P. aeruginosa to regulate its biofilm formation are mainly involved in arginine metabolism, glutamate production, magnesium transport, acetate metabolism, and the TCA cycle. PMID:25954752

  13. Pyruvate modifies metabolic flux and nutrient sensing during extracorporeal membrane oxygenation in an immature swine model

    PubMed Central

    Ledee, Dolena R.; Kajimoto, Masaki; O'Kelly Priddy, Colleen M.; Olson, Aaron K.; Isern, Nancy; Robillard-Frayne, Isabelle; Des Rosiers, Christine

    2015-01-01

    Extracorporeal membrane oxygenation (ECMO) provides mechanical circulatory support for infants and children with postoperative cardiopulmonary failure. Nutritional support is mandatory during ECMO although specific actions for substrates on the heart have not been delineated. Prior work shows that enhancing pyruvate oxidation promotes successful weaning from ECMO. Accordingly, we tested the hypothesis that prolonged systemic pyruvate supplementation activates pyruvate oxidation in an immature swine model in vivo. Twelve male mixed-breed Yorkshire piglets (age 30–49 days) received systemic infusion of either normal saline (group C) or pyruvate (group P) during the final 6 h of 8 h of ECMO. Over the final hour, piglets received [2-13C] pyruvate, as a reference substrate for oxidation, and [13C6]-l-leucine, as an indicator for amino acid oxidation and protein synthesis. A significant increase in lactate and pyruvate concentrations occurred, along with an increase in the absolute concentration of the citric acid cycle intermediates. An increase in anaplerotic flux through pyruvate carboxylation in group P occurred compared with no change in pyruvate oxidation. Additionally, pyruvate promoted an increase in the phosphorylation state of several nutrient-sensitive enzymes, like AMP-activated protein kinase and acetyl CoA carboxylase, suggesting activation for fatty acid oxidation. Pyruvate also promoted O-GlcNAcylation through the hexosamine biosynthetic pathway. In conclusion, although prolonged pyruvate supplementation did not alter pyruvate oxidation, it did elicit changes in nutrient- and energy-sensitive pathways. Therefore, the observed results support the further study of pyruvate and its downstream effect on cardiac function. PMID:25910802

  14. Modeling climate change impact in hospitality sector, using building resources consumption signature

    NASA Astrophysics Data System (ADS)

    Pinto, Armando; Bernardino, Mariana; Silva Santos, António; Pimpão Silva, Álvaro; Espírito Santo, Fátima

    2016-04-01

    Hotels are one of building types that consumes more energy and water per person and are vulnerable to climate change because in the occurrence of extreme events (heat waves, water stress) same failures could compromise the hotel services (comfort) and increase energy cost or compromise the landscape and amenities due to water use restrictions. Climate impact assessments and the development of adaptation strategies require the knowledge about critical climatic variables and also the behaviour of building. To study the risk and vulnerability of buildings and hotels to climate change regarding resources consumption (energy and water), previous studies used building energy modelling simulation (BEMS) tools to study the variation in energy and water consumption. In general, the climate change impact in building is evaluated studying the energy and water demand of the building for future climate scenarios. But, hotels are complex buildings, quite different from each other and assumption done in simplified BEMS aren't calibrated and usually neglect some important hotel features leading to projected estimates that do not usually match hotel sector understanding and practice. Taking account all uncertainties, the use of building signature (statistical method) could be helpful to assess, in a more clear way, the impact of Climate Change in the hospitality sector and using a broad sample. Statistical analysis of the global energy consumption obtained from bills shows that the energy consumption may be predicted within 90% confidence interval only with the outdoor temperature. In this article a simplified methodology is presented and applied to identify the climate change impact in hospitality sector using the building energy and water signature. This methodology is applied to sixteen hotels (nine in Lisbon and seven in Algarve) with four and five stars rating. The results show that is expect an increase in water and electricity consumption (manly due to the increase in

  15. Evaluation of the CONSUME and FOFEM fuel consumption models in pine and mixed hardwood forests of the eastern United States

    Treesearch

    Susan J. Prichard; Eva C. Karau; Roger D. Ottmar; Maureen C. Kennedy; James B. Cronan; Clinton S. Wright; Robert E. Keane

    2014-01-01

    Reliable predictions of fuel consumption are critical in the eastern United States (US), where prescribed burning is frequently applied to forests and air quality is of increasing concern. CONSUME and the First Order Fire Effects Model (FOFEM), predictive models developed to estimate fuel consumption and emissions from wildland fires, have not been systematically...

  16. Transient Thermo-fluid Model of Meniscus Behavior and Slag Consumption in Steel Continuous Casting

    NASA Astrophysics Data System (ADS)

    Jonayat, A. S. M.; Thomas, Brian G.

    2014-10-01

    The behavior of the slag layer between the oscillating mold wall, the slag rim, the slag/liquid steel interface, and the solidifying steel shell, is of immense importance for the surface quality of continuous-cast steel. A computational model of the meniscus region has been developed, that includes transient heat transfer, multi-phase fluid flow, solidification of the slag, and movement of the mold during an oscillation cycle. First, the model is applied to a lab experiment done with a "mold simulator" to verify the transient temperature-field predictions. Next, the model is verified by matching with available literature and plant measurements of slag consumption. A reasonable agreement has been observed for both temperature and flow-field. The predictions show that transient temperature behavior depends on the location of the thermocouple during the oscillation relative to the meniscus. During an oscillation cycle, heat transfer variations in a laboratory frame of reference are more severe than experienced by the moving mold thermocouples, and the local heat transfer rate is increased greatly when steel overflows the meniscus. Finally, the model is applied to conduct a parametric study on the effect of casting speed, stroke, frequency, and modification ratio on slag consumption. Slag consumption per unit area increases with increase of stroke and modification ratio, and decreases with increase of casting speed while the relation with frequency is not straightforward. The match between model predictions and literature trends suggests that this methodology can be used for further investigations.

  17. Re-estimating temperature-dependent consumption parameters in bioenergetics models for juvenile Chinook salmon

    USGS Publications Warehouse

    Plumb, John M.; Moffitt, Christine M.

    2015-01-01

    Researchers have cautioned against the borrowing of consumption and growth parameters from other species and life stages in bioenergetics growth models. In particular, the function that dictates temperature dependence in maximum consumption (Cmax) within the Wisconsin bioenergetics model for Chinook Salmon Oncorhynchus tshawytscha produces estimates that are lower than those measured in published laboratory feeding trials. We used published and unpublished data from laboratory feeding trials with subyearling Chinook Salmon from three stocks (Snake, Nechako, and Big Qualicum rivers) to estimate and adjust the model parameters for temperature dependence in Cmax. The data included growth measures in fish ranging from 1.5 to 7.2 g that were held at temperatures from 14°C to 26°C. Parameters for temperature dependence in Cmax were estimated based on relative differences in food consumption, and bootstrapping techniques were then used to estimate the error about the parameters. We found that at temperatures between 17°C and 25°C, the current parameter values did not match the observed data, indicating that Cmax should be shifted by about 4°C relative to the current implementation under the bioenergetics model. We conclude that the adjusted parameters for Cmax should produce more accurate predictions from the bioenergetics model for subyearling Chinook Salmon.

  18. Macro and Micro-Nutrients Intake, Food Groups Consumption and Dietary Habits among Female Students in Isfahan University of Medical Sciences.

    PubMed

    Azadbakht, L; Esmaillzadeh, A

    2012-04-01

    Improving the dietary intake among different groups and population is important for improving the health status. This study determines the nutrients and food group intake as well as dietary habits among female students in Isfahan University of Medical Sciences. Two hundreds and eighty nine healthy female youths who were randomly selected among students of Isfahan University of Medical Sciences in Isfahan, Iran were enrolled. A validated semi quantitative food frequency questionnaire was used. Folate, iron, calcium and fiber intake were lower than the recommended dietary allowances (RDA) amounts (70, 76, 90, 56% of RDA, respectively). Forty five percent of the population consumed fast foods 2 times a week and 35% used the frying oils for cooking most of the time. Female youths had lower amount of some micronutrients. Consuming frying oils, hydrogenated vegetable oils, and fast food intake should be limited among this group.

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

    USGS Publications Warehouse

    Robertson, Dale M.; Saad, David A.

    2013-01-01

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

  20. Sexual Preferences in Nutrient Utilization Regulate Oxygen Consumption and Reactive Oxygen Species Generation in Schistosoma mansoni: Potential Implications for Parasite Redox Biology

    PubMed Central

    Oliveira, Matheus P.; Correa Soares, Juliana B. R.; Oliveira, Marcus F.

    2016-01-01

    Schistosoma mansoni, one of the causative agents of human schistosomiasis, has a unique antioxidant network that is key to parasite survival and a valuable chemotherapeutic target. The ability to detoxify and tolerate reactive oxygen species increases along S. mansoni development in the vertebrate host, suggesting that adult parasites are more exposed to redox challenges than young stages. Indeed, adult parasites are exposed to multiple redox insults generated from blood digestion, activated immune cells, and, potentially, from their own parasitic aerobic metabolism. However, it remains unknown how reactive oxygen species are produced by S. mansoni metabolism, as well as their biological effects on adult worms. Here, we assessed the contribution of nutrients and parasite gender to oxygen utilization pathways, and reactive oxygen species generation in whole unpaired adult S. mansoni worms. We also determined the susceptibilities of both parasite sexes to a pro-oxidant challenge. We observed that glutamine and serum importantly contribute to both respiratory and non-respiratory oxygen utilization in adult worms, but with different proportions among parasite sexes. Analyses of oxygen utilization pathways revealed that respiratory rates were high in male worms, which contrast with high non-respiratory rates in females, regardless nutritional sources. Interestingly, mitochondrial complex I-III activity was higher than complex IV specifically in females. We also observed sexual preferences in substrate utilization to sustain hydrogen peroxide production towards glucose in females, and glutamine in male worms. Despite strikingly high oxidant levels and hydrogen peroxide production rates, female worms were more resistant to a pro-oxidant challenge than male parasites. The data presented here indicate that sexual preferences in nutrient metabolism in adult S. mansoni worms regulate oxygen utilization and reactive oxygen species production, which may differently contribute

  1. Sexual Preferences in Nutrient Utilization Regulate Oxygen Consumption and Reactive Oxygen Species Generation in Schistosoma mansoni: Potential Implications for Parasite Redox Biology.

    PubMed

    Oliveira, Matheus P; Correa Soares, Juliana B R; Oliveira, Marcus F

    2016-01-01

    Schistosoma mansoni, one of the causative agents of human schistosomiasis, has a unique antioxidant network that is key to parasite survival and a valuable chemotherapeutic target. The ability to detoxify and tolerate reactive oxygen species increases along S. mansoni development in the vertebrate host, suggesting that adult parasites are more exposed to redox challenges than young stages. Indeed, adult parasites are exposed to multiple redox insults generated from blood digestion, activated immune cells, and, potentially, from their own parasitic aerobic metabolism. However, it remains unknown how reactive oxygen species are produced by S. mansoni metabolism, as well as their biological effects on adult worms. Here, we assessed the contribution of nutrients and parasite gender to oxygen utilization pathways, and reactive oxygen species generation in whole unpaired adult S. mansoni worms. We also determined the susceptibilities of both parasite sexes to a pro-oxidant challenge. We observed that glutamine and serum importantly contribute to both respiratory and non-respiratory oxygen utilization in adult worms, but with different proportions among parasite sexes. Analyses of oxygen utilization pathways revealed that respiratory rates were high in male worms, which contrast with high non-respiratory rates in females, regardless nutritional sources. Interestingly, mitochondrial complex I-III activity was higher than complex IV specifically in females. We also observed sexual preferences in substrate utilization to sustain hydrogen peroxide production towards glucose in females, and glutamine in male worms. Despite strikingly high oxidant levels and hydrogen peroxide production rates, female worms were more resistant to a pro-oxidant challenge than male parasites. The data presented here indicate that sexual preferences in nutrient metabolism in adult S. mansoni worms regulate oxygen utilization and reactive oxygen species production, which may differently contribute

  2. Nutrient-induced modulation of gene expression and cellular functions: modeling epigenetic regulation in bovine cells

    USDA-ARS?s Scientific Manuscript database

    Volatile fatty acids (VFA), especially butyrate, participate in metabolism both as nutrients and as regulators of histone deacetylation. The major biochemical change that occurs in cells treated with butyrate is the global hyperacetylation of histones. One paradigmatic example of the nutrient-epige...

  3. Identification of spatiotemporal nutrient patterns in a coastal bay via an integrated k-means clustering and gravity model.

    PubMed

    Chang, Ni-Bin; Wimberly, Brent; Xuan, Zhemin

    2012-03-01

    This study presents an integrated k-means clustering and gravity model (IKCGM) for investigating the spatiotemporal patterns of nutrient and associated dissolved oxygen levels in Tampa Bay, Florida. By using a k-means clustering analysis to first partition the nutrient data into a user-specified number of subsets, it is possible to discover the spatiotemporal patterns of nutrient distribution in the bay and capture the inherent linkages of hydrodynamic and biogeochemical features. Such patterns may then be combined with a gravity model to link the nutrient source contribution from each coastal watershed to the generated clusters in the bay to aid in the source proportion analysis for environmental management. The clustering analysis was carried out based on 1 year (2008) water quality data composed of 55 sample stations throughout Tampa Bay collected by the Environmental Protection Commission of Hillsborough County. In addition, hydrological and river water quality data of the same year were acquired from the United States Geological Survey's National Water Information System to support the gravity modeling analysis. The results show that the k-means model with 8 clusters is the optimal choice, in which cluster 2 at Lower Tampa Bay had the minimum values of total nitrogen (TN) concentrations, chlorophyll a (Chl-a) concentrations, and ocean color values in every season as well as the minimum concentration of total phosphorus (TP) in three consecutive seasons in 2008. The datasets indicate that Lower Tampa Bay is an area with limited nutrient input throughout the year. Cluster 5, located in Middle Tampa Bay, displayed elevated TN concentrations, ocean color values, and Chl-a concentrations, suggesting that high values of colored dissolved organic matter are linked with some nutrient sources. The data presented by the gravity modeling analysis indicate that the Alafia River Basin is the major contributor of nutrients in terms of both TP and TN values in all seasons

  4. How much certainty is enough? Validation of a nutrient retention model for prioritizing watershed conservation in North Carolina

    NASA Astrophysics Data System (ADS)

    Hamel, P.; Chaplin-Kramer, R.; Benner, R.

    2013-12-01

    Context Quantifying ecosystems services, nature's benefits to people, is an area of active research in water resource management. Increasingly, water utilities and basin management authorities are interested in optimizing watershed scale conservation strategies to mitigate the economic and environmental impacts of land-use and hydrological changes. While many models are available to represent hydrological processes in a spatially explicit way, large uncertainties remain associated with i) the biophysical outputs of these models (e.g., nutrient concentration at a given location), and ii) the service valuation method to support specific decisions (e.g., targeting conservation areas based on their contribution to retaining nutrient). Better understanding these uncertainties and their impact on the decision process is critical for establishing credibility of such models in a planning context. Methods To address this issue in an emerging payments for watershed services program in the Cape Fear watershed, North Carolina, USA, we tested and validated the use of a nutrient retention model (InVEST) for targeting conservation activities. Specifically, we modeled water yield and nutrient transport throughout the watershed and valued the retention service provided by forested areas. Observed flow and water quality data at multiple locations allowed calibration of the model at the watershed level as well as the subwatershed level. By comparing the results from each model parameterization, we were able to assess the uncertainties related to both the model structure and parameter estimation. Finally, we assessed the use of the model for climate scenario simulation by characterizing its ability to represent inter-annual variability. Results and discussion The spatial analyses showed that the two calibration approaches could yield distinct parameter sets, both for the water yield and the nutrient model. These results imply a difference in the absolute nutrient concentration

  5. An example of model result correction to study the impact of climate change on electricity consumption

    NASA Astrophysics Data System (ADS)

    Parey, S.; Galloy, G.; Nogaj, M.

    2012-04-01

    Climate is changing and temperature evolutions are thought to impact electricity consumption in the future. In order to estimate these possible shifts, climate model results for two future periods: 2050 and 2100 are considered. However, the use of the electricity consumption forecast model with climate model outputs for the current period give unrealistic results compared to forecasts made with observations. As a matter of fact, consumption is forecasted using a taylor-designed mean of French temperatures. Therefore, it is necessary for the model results to be as close as possible to this observed mean. The first studies had been made using the so-called "delta method", which consists in adding future changes to the observations. This however supposes that there is no variance change, which is not necessarily valid. Thus, in a second step, the percentile correction method has been used, firstly considering the whole annual distribution. This is however not satisfactory, as the seasonal distributions remain too much biased. Thus, the correction had to be applied on a monthly basis. The method and results of the correction will be presented for this example of France.

  6. Modeling transit bus fuel consumption on the basis of cycle properties.

    PubMed

    Delgado, Oscar F; Clark, Nigel N; Thompson, Gregory J

    2011-04-01

    A method exists to predict heavy-duty vehicle fuel economy and emissions over an "unseen" cycle or during unseen on-road activity on the basis of fuel consumption and emissions data from measured chassis dynamometer test cycles and properties (statistical parameters) of those cycles. No regression is required for the method, which relies solely on the linear association of vehicle performance with cycle properties. This method has been advanced and examined using previously published heavy-duty truck data gathered using the West Virginia University heavy-duty chassis dynamometer with the trucks exercised over limited test cycles. In this study, data were available from a Washington Metropolitan Area Transit Authority emission testing program conducted in 2006. Chassis dynamometer data from two conventional diesel buses, two compressed natural gas buses, and one hybrid diesel bus were evaluated using an expanded driving cycle set of 16 or 17 different driving cycles. Cycle properties and vehicle fuel consumption measurements from three baseline cycles were selected to generate a linear model and then to predict unseen fuel consumption over the remaining 13 or 14 cycles. Average velocity, average positive acceleration, and number of stops per distance were found to be the desired cycle properties for use in the model. The methodology allowed for the prediction of fuel consumption with an average error of 8.5% from vehicles operating on a diverse set of chassis dynamometer cycles on the basis of relatively few experimental measurements. It was found that the data used for prediction should be acquired from a set that must include an idle cycle along with a relatively slow transient cycle and a relatively high speed cycle. The method was also applied to oxides of nitrogen prediction and was found to have less predictive capability than for fuel consumption with an average error of 20.4%.

  7. Predator-scent stress, ethanol consumption and the opioid system in an animal model of PTSD.

    PubMed

    Manjoch, Hadar; Vainer, Ella; Matar, Michael; Ifergane, Gal; Zohar, Joseph; Kaplan, Zeev; Cohen, Hagit

    2016-06-01

    Emerging literature points to stress exposure as a potential contributor to the development of alcohol abuse, but animal models have yielded inconsistent results. Converging experimental data indicate that the endogenous opioid system modulates alcohol consumption and stress regulation. The aim of the present study is to examine the interplay between stress exposure, behavioral stress responses, ethanol (EtOH) consumption and the endogenous opioid system in an animal model of posttraumatic stress disorder. Rats were exposed to stress and then tested in a two-bottle free choice (TBC) assay or in a conditioned place preference paradigm. In some experiments, the endogenous opioid system was pharmacologically manipulated prior to stress exposure. The behavioral outcomes of stress exposure were assessed in an elevated plus-maze, with the acoustic startle response, and by monitoring the freezing response to trauma reminder. Immunoreactivity of phosphorylated opioid receptors in hippocampal subregions was also measured. Stress significantly increased the consumption of EtOH in the TBC assay. The severity of the behavioral response to stress was associated with EtOH consumption, cue-triggered freezing response to a trauma reminder, and endogenous levels of phosphorylated opioid receptors in the hippocampus. Pharmacologically manipulating the endogenous opioid system prior to stress exposure attenuated trauma cue-triggered freezing responses and blocked predator scent stress-induced potentiation of EtOH consumption. These data demonstrate a stress-induced potentiation of EtOH self-administration and reveal a clear association between individual patterns of the behavioral response to stress and alcohol preference, while indicating a role for the endogenous opioid system in the neurobiological response to stress. Copyright © 2016. Published by Elsevier B.V.

  8. Do gamblers eat more salt? Testing a latent trait model of covariance in consumption.

    PubMed

    Goodwin, Belinda C; Browne, Matthew; Rockloff, Matthew; Donaldson, Phillip

    2015-09-01

    A diverse class of stimuli, including certain foods, substances, media, and economic behaviours, may be described as 'reward-oriented' in that they provide immediate reinforcement with little initial investment. Neurophysiological and personality concepts, including dopaminergic dysfunction, reward sensitivity and rash impulsivity, each predict the existence of a latent behavioural trait that leads to increased consumption of all stimuli in this class. Whilst bivariate relationships (co-morbidities) are often reported in the literature, to our knowledge, a multivariate investigation of this possible trait has not been done. We surveyed 1,194 participants (550 male) on their typical weekly consumption of 11 types of reward-oriented stimuli, including fast food, salt, caffeine, television, gambling products, and illicit drugs. Confirmatory factor analysis was used to compare models in a 3×3 structure, based on the definition of a single latent factor (none, fixed loadings, or