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Sample records for intake fraction approach

  1. Exposure to motor vehicle emissions: An intake fraction approach

    SciTech Connect

    Marshall, Julian D.

    2002-05-22

    Motor vehicles are a significant source of population exposure to air pollution. Focusing on California's South Coast Air Basin as a case study, the author combines ambient monitoring station data with hourly time-activity patterns to determine the population intake of motor vehicle emissions during 1996-1999. Three microenvironments are considered wherein the exposure to motor vehicle emissions is higher than in ambient air: in and near vehicles, inside a building that is near a freeway, and inside a residence with an attached garage. Total motor vehicle emissions are taken from the EMFAC model. The 15 million people in the South Coast inhale 0.0048% of primary, nonreactive compounds emitted into the basin by motor vehicles. Intake of motor vehicle emissions is 46% higher than the average ambient concentration times the average breathing rate, because of microenvironments and because of temporal and spatial correlation among breathing rates, concentrations, and population densities. Intake fraction (iF) summarizes the emissions-to-intake relationship as the ratio of population intake to total emissions. iF is a population level exposure metric that incorporates spatial, temporal, and interindividual variability in exposures. iFs can facilitate the calculation of population exposures by distilling complex emissions-transport-receptor relationships. The author demonstrates this point by predicting the population intake of various primary gaseous emissions from motor vehicles, based on the intake fraction for benzene and carbon monoxide.

  2. A CFD modeling study in an urban street canyon for ultrafine particles and population exposure: The intake fraction approach.

    PubMed

    Habilomatis, George; Chaloulakou, Archontoula

    2015-10-15

    Air quality in street canyons is of major importance, since the highest pollution levels are often encountered in these microenvironments. The canyon effect (reduced natural ventilation) makes them "hot spots" for particulate pollution contributing to adverse health effects for the exposed population. In this study we tried to characterize the influence of UFP (ultrafine particle) emissions from traffic on population exposure in an urban street canyon, by applying the intake fraction (iF) approach. One month long measurements of UFP levels have been monitored and used for the need of this study. We applied a three dimensional computational fluid dynamic (CFD) model based on real measurements for the simulation of UFP levels. We used infiltration factors, evaluated on a daily basis for the under study area, to estimate the indoor UFP levels. As a result the intake fraction for the pedestrians, residents and office workers is in the range of (1E-5)-(1E-4). The street canyon is mostly residential justifying partially the higher value of intake fraction for residents (1E-4). The above iF value is on the same order of magnitude with the corresponding one evaluated in a relative street canyon study. The total iF value in this microenvironment is one order of magnitude higher than ours, explained partially by the different use and activities. Two specific applications of iF to assess prioritization among emission sources and environmental justice issues are also examined. We ran a scenario with diesel and gasoline cars and diesel fueled vehicle seems to be a target source to improve overall iF. Our application focus on a small residential area, typical of urban central Athens, in order to evaluate high resolution iF. The significance of source-exposure relationship study in a micro scale is emphasized by recent research. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Primary and secondary particulate matter intake fraction from different height emission sources

    NASA Astrophysics Data System (ADS)

    Parvez, Fatema; Lamancusa, Carmen; Wagstrom, Kristina

    2017-09-01

    This study uses intake fraction, the fraction of emissions that are inhaled, to compare potential particulate matter exposure among different height emission sources. We use the Particulate Matter Source Apportionment Technology (PSAT) in the Comprehensive Air Quality Model with Extensions (CAMx) to estimate intake fraction for primary and secondary particulate matter species from different height emission sources. We develop an approach to quantify intake fraction for both primary and secondary particulate matter species emitted from all types of emission sources in the contiguous United States. To compute intake fraction for secondary particulate matter species, we consider the inhalation of the precursor gas and condensed species based on the common atomic unit between the emitted gas and particulate matter product. Our calculated intake fraction varies from 1.0 to 4.9 per million for primary particulate matter, 0.4 to almost 6.0 per million for secondary species, including inhalation of both particulate matter and the relevant precursor species. Intake fraction is consistently higher in the winter than the summer for all species from all emission heights. The shortest height sources, which include area sources, display intake fractions over an order of magnitude greater than more elevated sources.

  4. Numerical approaches to fractional calculus and fractional ordinary differential equation

    NASA Astrophysics Data System (ADS)

    Li, Changpin; Chen, An; Ye, Junjie

    2011-05-01

    Nowadays, fractional calculus are used to model various different phenomena in nature, but due to the non-local property of the fractional derivative, it still remains a lot of improvements in the present numerical approaches. In this paper, some new numerical approaches based on piecewise interpolation for fractional calculus, and some new improved approaches based on the Simpson method for the fractional differential equations are proposed. We use higher order piecewise interpolation polynomial to approximate the fractional integral and fractional derivatives, and use the Simpson method to design a higher order algorithm for the fractional differential equations. Error analyses and stability analyses are also given, and the numerical results show that these constructed numerical approaches are efficient.

  5. Characterizing Aggregated Exposure to Primary Particulate Matter: Recommended Intake Fractions for Indoor and Outdoor Sources.

    PubMed

    Fantke, Peter; Jolliet, Olivier; Apte, Joshua S; Hodas, Natasha; Evans, John; Weschler, Charles J; Stylianou, Katerina S; Jantunen, Matti; McKone, Thomas E

    2017-08-15

    Exposure to fine particulate matter (PM2.5) from indoor and outdoor sources is a leading environmental contributor to global disease burden. In response, we established under the auspices of the UNEP/SETAC Life Cycle Initiative a coupled indoor-outdoor emission-to-exposure framework to provide a set of consistent primary PM2.5 aggregated exposure factors. We followed a matrix-based mass balance approach for quantifying exposure from indoor and ground-level urban and rural outdoor sources using an effective indoor-outdoor population intake fraction and a system of archetypes to represent different levels of spatial detail. Emission-to-exposure archetypes range from global indoor and outdoor averages, via archetypal urban and indoor settings, to 3646 real-world cities in 16 parametrized subcontinental regions. Population intake fractions from urban and rural outdoor sources are lowest in Northern regions and Oceania and highest in Southeast Asia with population-weighted means across 3646 cities and 16 subcontinental regions of, respectively, 39 ppm (95% confidence interval: 4.3-160 ppm) and 2 ppm (95% confidence interval: 0.2-6.3 ppm). Intake fractions from residential and occupational indoor sources range from 470 ppm to 62 000 ppm, mainly as a function of air exchange rate and occupancy. Indoor exposure typically contributes 80-90% to overall exposure from outdoor sources. Our framework facilitates improvements in air pollution reduction strategies and life cycle impact assessments.

  6. A dynamic programming approach to adaptive fractionation

    NASA Astrophysics Data System (ADS)

    Ramakrishnan, Jagdish; Craft, David; Bortfeld, Thomas; Tsitsiklis, John N.

    2012-03-01

    We conduct a theoretical study of various solution methods for the adaptive fractionation problem. The two messages of this paper are as follows: (i) dynamic programming (DP) is a useful framework for adaptive radiation therapy, particularly adaptive fractionation, because it allows us to assess how close to optimal different methods are, and (ii) heuristic methods proposed in this paper are near-optimal, and therefore, can be used to evaluate the best possible benefit of using an adaptive fraction size. The essence of adaptive fractionation is to increase the fraction size when the tumor and organ-at-risk (OAR) are far apart (a ‘favorable’ anatomy) and to decrease the fraction size when they are close together. Given that a fixed prescribed dose must be delivered to the tumor over the course of the treatment, such an approach results in a lower cumulative dose to the OAR when compared to that resulting from standard fractionation. We first establish a benchmark by using the DP algorithm to solve the problem exactly. In this case, we characterize the structure of an optimal policy, which provides guidance for our choice of heuristics. We develop two intuitive, numerically near-optimal heuristic policies, which could be used for more complex, high-dimensional problems. Furthermore, one of the heuristics requires only a statistic of the motion probability distribution, making it a reasonable method for use in a realistic setting. Numerically, we find that the amount of decrease in dose to the OAR can vary significantly (5-85%) depending on the amount of motion in the anatomy, the number of fractions and the range of fraction sizes allowed. In general, the decrease in dose to the OAR is more pronounced when: (i) we have a high probability of large tumor-OAR distances, (ii) we use many fractions (as in a hyper-fractionated setting) and (iii) we allow large daily fraction size deviations.

  7. Defining Product Intake Fraction to Quantify and Compare Exposure to Consumer Products.

    PubMed

    Jolliet, Olivier; Ernstoff, Alexi S; Csiszar, Susan A; Fantke, Peter

    2015-08-04

    There is a growing consciousness that exposure studies need to better cover near-field exposure associated with products use. To consistently and quantitatively compare human exposure to chemicals in consumer products, we introduce the concept of product intake fraction, as the fraction of a chemical within a product that is eventually taken in by the human population. This metric enables consistent comparison of exposures during consumer product use for different product-chemical combinations, exposure duration, exposure routes and pathways and for other life cycle stages. We present example applications of the product intake fraction concept, for two chemicals in two personal care products and two chemicals encapsulated in two articles, showing how intakes of these chemicals can primarily occur during product use. We demonstrate the utility of the product intake fraction and its application modalities within life cycle assessment and risk assessment contexts. The product intake fraction helps to provide a clear interface between the life cycle inventory and impact assessment phases, to identify best suited sentinel products and to calculate overall exposure to chemicals in consumer products, or back-calculate maximum allowable concentrations of substances inside products.

  8. Spatially resolved intake fraction estimates for primary and secondary particulate matter in the United States

    NASA Astrophysics Data System (ADS)

    Lamancusa, Carmen; Parvez, Fatema; Wagstrom, Kristina

    2017-02-01

    This study uses intake fraction, the fraction of emissions that are inhaled from a given source, to quantify how emissions from different regions proportionally contribute to human exposure to both primary and secondary particulate matter species. The intake fraction for secondary species is defined using the common atomic constituents between precursor species and products, allowing estimates to include both primary and secondary species. The Particulate Matter Source Apportionment Technology (PSAT) in the Comprehensive Air Quality Model with Extensions (CAMx) regional air quality model is used to calculate the intake fraction for twenty-five source regions throughout the contiguous United States over four seasons. The calculations use spatially explicit emissions and population density to more accurately capture the variation in intake fraction between regions. The spatially explicit emissions allow for the calculation of spatial trends and variations within the intake fraction. More specifically it allows for the calculation of the amount of intake that occurs within a given distance of the emissions source or source region. Based on the results sulfate inhalation occurs over larger distances than other particulate matter species. For most regions, a substantial fraction (>75%) of the inhalation occurs within 50 km for all seasons, demonstrating that efforts to reduce emissions will have the largest health impact on the local community. Furthermore the distance over which 75% of the inhalation occurs increases by 20% for all species during the winter and a larger percentage of pollutants emitted during the winter are inhaled relative to pollutants emitted during other seasons. This demonstrates that emission reductions during the winter will have a greater impact on health than reductions during other seasons.

  9. Body Fractions: A Physical Approach to Fraction Learning

    ERIC Educational Resources Information Center

    Mills, Judith

    2011-01-01

    Many students experience great difficulty understanding the meaning of fractions. For many students who have spent their early mathematics lessons focusing on counting (whole) numbers, recognising that there are many numbers between those whole numbers called fractional numbers, is quite revolutionary. The foundation of understanding fractions is…

  10. Human intake fraction of toxic pollutants: a model comparison between caltox and uses-lca

    SciTech Connect

    Huijbregts, Mark A.J.; Geelen, Loes M.J.; Hertwich, Edgar G.; McKone, Thomas E.; van de Meent, Dik

    2004-01-06

    In Life Cycle Assessment and Comparative Risk Assessment potential human exposure to toxic pollutants can be expressed as the human intake fraction (iF), representing the fraction of the quantity emitted that enters the human population. To assess model uncertainty in the human intake fraction, ingestion and inhalation iFs of 367 substances emitted to air and freshwater were calculated with two commonly applied multi-media fate and exposure models, CalTOX and USES-LCA. Comparison of the model outcomes reveal that uncertainty in the ingestion iFs was up to a factor of 70. The uncertainty in the inhalation iFs was up to a factor of 865,000. The comparison showed that relatively few model differences account for the uncertainties found. An optimal model structure in the calculation of human intake fractions can be achieved by including (1) rain and no-rain scenarios, (2) a continental sea water compartment, (3) drinking water purification, (4) pH-correction of chemical properties, and (5) aerosol-associated deposition on plants. Finally, vertical stratification of the soil compartment combined with a chemical-dependent soil depth may be considered in future intake fraction calculations.

  11. Intake fraction distributions for benzene from vehicles in the Helsinki metropolitan area

    NASA Astrophysics Data System (ADS)

    Loh, Miranda M.; Soares, Joana; Karppinen, Ari; Kukkonen, Jaakko; Kangas, Leena; Riikonen, Kari; Kousa, Anu; Asikainen, Arja; Jantunen, Matti J.

    The intake fraction (iF) gives a measure of the portion of a source's emissions that is inhaled by an exposed population over a defined period of time. This study examines spatial and population-based iF distributions of a known human carcinogen, benzene, from a ubiquitous urban source, local vehicular traffic, in the Helsinki Metropolitan Area using three computational methods. The first method uses the EXPAND model (EXPosure to Air pollution, especially to Nitrogen Dioxide and particulate matter), which incorporates spatial and temporal information on population activity patterns as well as urban-scale and street canyon dispersion models to predict spatial population exposure distributions. The second method uses data from the personal monitoring study EXPOLIS (Air Pollution Exposure Distributions of Adult Urban Populations in Europe) to estimate the intake fractions for individuals in the study. The third method, a one-compartment box model provides estimates within an order-of-magnitude or better for non-reactive agents in an urban area. Population intake fractions are higher using the personal monitoring data method (median iF 30 per million, mean iF 39 per million) compared with the spatial model (annual mean iF 10 per million) and the box model (median iF 4 per million, mean iF 7 per million). In particular, this study presents detailed intake fraction distributions on several different levels (spatial, individual, and generic) for the same urban area.

  12. Dietary fiber and fiber fraction intakes and colorectal cancer risk in Chinese adults.

    PubMed

    Zhong, Xiao; Fang, Yu-Jing; Pan, Zhi-Zhong; Lu, Min-Shan; Zheng, Mei-Chun; Chen, Yu-Ming; Zhang, Cai-Xia

    2014-01-01

    Few studies have been conducted in Chinese adults to investigate the effect of fiber intake on colorectal cancer risk. The present study aimed to examine the associations of dietary fiber and fiber fraction intakes with colorectal cancer risk in Chinese adults. A total of 613 cases with colorectal cancer were consecutively recruited between July 2010 and October 2012 and frequency matched to 613 controls by age (5-yr interval) and gender. Dietary information was collected through a validated food frequency questionnaire by face-to-face interviews. Multivariate logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) after adjustment for potential confounders. Total dietary fiber and fiber fraction intakes were found to be inversely associated with colorectal cancer risk. Compared with the lowest quartile, the adjusted ORs (95% CIs) for the highest quartile were 0.38 (0.27-0.55) for total dietary fiber, 0.45 (0.32-0.64) for vegetable fiber, and 0.41 (0.28-0.58) for fruit fiber, respectively. In addition, no significant association was found between soy fiber intake and colorectal cancer risk. This study showed that a high intake of dietary fiber, particularly derived from vegetables and fruit, was inversely associated with colorectal cancer risk in Chinese adults.

  13. Air-Quality Impacts and Intake Fraction of PM2.5 during the 2013 Rim Megafire.

    PubMed

    Navarro, Kathleen M; Cisneros, Ricardo; O'Neill, Susan M; Schweizer, Don; Larkin, Narasimhan K; Balmes, John R

    2016-11-01

    The 2013 Rim Fire was the third largest wildfire in California history and burned 257 314 acres in the Sierra Nevada Mountains. We evaluated air-quality impacts of PM2.5 from smoke from the Rim Fire on receptor areas in California and Nevada. We employed two approaches to examine the air-quality impacts: (1) an evaluation of PM2.5 concentration data collected by temporary and permanent air-monitoring sites and (2) an estimation of intake fraction (iF) of PM2.5 from smoke. The Rim Fire impacted locations in the central Sierra nearest to the fire and extended to the northern Sierra Nevada Mountains of California and Nevada monitoring sites. Daily 24-h average PM2.5 concentrations measured at 22 air monitors had an average concentration of 20 μg/m(3) and ranged from 0 to 450 μg/m(3). The iF for PM2.5 from smoke during the active fire period was 7.4 per million, which is slightly higher than representative iF values for PM2.5 in rural areas and much lower than for urban areas. This study is a unique application of intake fraction to examine emissions-to-exposure for wildfires and emphasizes that air-quality impacts are not only localized to communities near large fires but can extend long distances and affect larger urban areas.

  14. Global intraurban intake fractions for primary air pollutants from vehicles and other distributed sources.

    PubMed

    Apte, Joshua S; Bombrun, Emilie; Marshall, Julian D; Nazaroff, William W

    2012-03-20

    We model intraurban intake fraction (iF) values for distributed ground-level emissions in all 3646 global cities with more than 100,000 inhabitants, encompassing a total population of 2.0 billion. For conserved primary pollutants, population-weighted median, mean, and interquartile range iF values are 26, 39, and 14-52 ppm, respectively, where 1 ppm signifies 1 g inhaled/t emitted. The global mean urban iF reported here is roughly twice as large as previous estimates for cities in the United States and Europe. Intake fractions vary among cities owing to differences in population size, population density, and meteorology. Sorting by size, population-weighted mean iF values are 65, 35, and 15 ppm, respectively, for cities with populations larger than 3, 0.6-3, and 0.1-0.6 million. The 20 worldwide megacities (each >10 million people) have a population-weighted mean iF of 83 ppm. Mean intraurban iF values are greatest in Asia and lowest in land-rich high-income regions. Country-average iF values vary by a factor of 3 among the 10 nations with the largest urban populations.

  15. Global Intraurban Intake Fractions for Primary Air Pollutants from Vehicles and Other Distributed Sources

    PubMed Central

    2012-01-01

    We model intraurban intake fraction (iF) values for distributed ground-level emissions in all 3646 global cities with more than 100 000 inhabitants, encompassing a total population of 2.0 billion. For conserved primary pollutants, population-weighted median, mean, and interquartile range iF values are 26, 39, and 14–52 ppm, respectively, where 1 ppm signifies 1 g inhaled/t emitted. The global mean urban iF reported here is roughly twice as large as previous estimates for cities in the United States and Europe. Intake fractions vary among cities owing to differences in population size, population density, and meteorology. Sorting by size, population-weighted mean iF values are 65, 35, and 15 ppm, respectively, for cities with populations larger than 3, 0.6–3, and 0.1–0.6 million. The 20 worldwide megacities (each >10 million people) have a population-weighted mean iF of 83 ppm. Mean intraurban iF values are greatest in Asia and lowest in land-rich high-income regions. Country-average iF values vary by a factor of 3 among the 10 nations with the largest urban populations. PMID:22332712

  16. Individual and population intake fractions of diesel particulate matter (DPM) in bus stop microenvironments.

    PubMed

    Xu, Jia; Jin, Taosheng; Miao, Yaning; Han, Bin; Gao, Jiajia; Bai, Zhipeng; Xu, Xiaohong

    2015-12-01

    Diesel particulate matter (DPM) is associated with adverse human health effects. This study aims to investigate the relationship between DPM exposure and emissions by estimating the individual intake fraction (iFi) and population intake fraction (iFp) of DPM. Daily average concentrations of particulate matter at two bus stops during rush hours were measured, and then they were apportioned to DPM due to heavy-duty diesel bus emissions using Chemical Mass Balance Model. The DPM emissions of diesel buses for different driving conditions (idling, creeping and traveling) were estimated on the basis of field observations and published emission factors. The median iFi of DPM was 0.67 and 1.39 per million for commuters standing at the bus stop and pedestrians/cyclists passing through the bus stop during rush hours, respectively. The median iFp of DPM was 94 per million. Estimations of iFi and iFp of DPM are potentially significant for exposure assessment and risk management. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Matrix approach to discrete fractional calculus II: Partial fractional differential equations

    NASA Astrophysics Data System (ADS)

    Podlubny, Igor; Chechkin, Aleksei; Skovranek, Tomas; Chen, YangQuan; Vinagre Jara, Blas M.

    2009-05-01

    A new method that enables easy and convenient discretization of partial differential equations with derivatives of arbitrary real order (so-called fractional derivatives) and delays is presented and illustrated on numerical solution of various types of fractional diffusion equation. The suggested method is the development of Podlubny's matrix approach [I. Podlubny, Matrix approach to discrete fractional calculus, Fractional Calculus and Applied Analysis 3 (4) (2000) 359-386]. Four examples of numerical solution of fractional diffusion equation with various combinations of time-/space-fractional derivatives (integer/integer, fractional/integer, integer/fractional, and fractional/fractional) with respect to time and to the spatial variable are provided in order to illustrate how simple and general is the suggested approach. The fifth example illustrates that the method can be equally simply used for fractional differential equations with delays. A set of MATLAB routines for the implementation of the method as well as sample code used to solve the examples have been developed.

  18. Developing intake fraction estimates with limited data: Comparison of methods in Mexico City

    NASA Astrophysics Data System (ADS)

    Stevens, Gretchen; de Foy, Benjamin; West, J. Jason; Levy, Jonathan I.

    In order to estimate the health benefits of reducing mobile source emissions, analysts typically use detailed atmospheric models to estimate the change in population exposure that results from a given change in emissions. However, this may not be feasible in settings where data are limited or policy decisions are needed in the short term. Intake fraction (iF), defined as the fraction of emissions of a pollutant or its precursor that is inhaled by the population, is a metric that can be used to compare exposure assessment methods in a health benefits analysis context. To clarify the utility of rapid-assessment methods, we calculate particulate matter iFs for the Mexico City Metropolitan Area using five methods, some more resource intensive than others. First, we create two simple box models to describe dispersion of primary fine particulate matter (PM 2.5) in the Mexico City basin. Second, we extrapolate iFs for primary PM 2.5, ammonium sulfate, and ammonium nitrate from US values using a regression model. Third, we calculate iFs by assuming a linear relationship between emissions and population-weighted concentrations of primary PM 2.5, ammonium nitrate, and ammonium sulfate (a particle composition method). Finally, we estimate PM iFs from detailed atmospheric dispersion and chemistry models run for only a short period of time. Intake fractions vary by up to a factor of five, from 23 to 120 per million for primary PM 2.5. Estimates of 60, 7, and 0.7 per million for primary PM, secondary ammonium sulfate, and secondary ammonium nitrate, respectively, represent credible central estimates, with an approximate factor of two uncertainty surrounding each estimate. Our results emphasize that multiple rapid-assessment methods can provide meaningful estimates of iFs in resource-limited environments, and that formal uncertainty analysis, with special attention to model biases and uncertainty, would be important for health benefits analyses.

  19. Complex network approach to fractional time series

    SciTech Connect

    Manshour, Pouya

    2015-10-15

    In order to extract correlation information inherited in stochastic time series, the visibility graph algorithm has been recently proposed, by which a time series can be mapped onto a complex network. We demonstrate that the visibility algorithm is not an appropriate one to study the correlation aspects of a time series. We then employ the horizontal visibility algorithm, as a much simpler one, to map fractional processes onto complex networks. The degree distributions are shown to have parabolic exponential forms with Hurst dependent fitting parameter. Further, we take into account other topological properties such as maximum eigenvalue of the adjacency matrix and the degree assortativity, and show that such topological quantities can also be used to predict the Hurst exponent, with an exception for anti-persistent fractional Gaussian noises. To solve this problem, we take into account the Spearman correlation coefficient between nodes' degrees and their corresponding data values in the original time series.

  20. New approaches in the derivation of acceptable daily intake (ADI)

    SciTech Connect

    Dourson, M.L.

    1986-01-01

    Current methods for estimating human health risks from exposure to threshold-acting toxicants in water or food, such as those established by the U.S. EPA, the FDA, the NAS, the WHO and the FAO, consider only chronic or lifetime exposure to individual chemicals. These methods generally estimate a single, constant daily intake rate which is low enough to be considered safe or acceptable. The intake rate is termed the acceptable daily intake (ADI). Two problems with the approach have been recognized. The first problem is that the method does not readily account for the number of animals used to determine the appropriate 'no-observed-effect-level' (NOEL). The second problem with the current approach is that the slope of the dose-response curve of the critical toxic effect is generally ignored in estimating the ADI. The report illustrates both a revised approach to estimate ADIs with all toxicity data which includes methods for partial lifetime assessment, and novel methods for ADI estimation with quantal or continuous toxicity data. The latter method addresses to a degree the common problems with the current approach.

  1. Intake fraction of PM2.5 and NOX from vehicle emissions in Beijing based on personal exposure data

    NASA Astrophysics Data System (ADS)

    Du, Xuan; Wu, Ye; Fu, Lixin; Wang, Shuxiao; Zhang, Shaojun; Hao, Jiming

    2012-09-01

    The intake fraction (iF) is the portion of attributable population intake of a source emissions, and is used to link pollutant emissions and population exposure. This study is the first work that reported individual intake fraction of PM2.5 and NOX from vehicle emissions based on personal exposure data in China. We employed PM2.5 and NOX measurement data from 24-h personal exposure sampling and concentration monitoring in traffic environments in the urban area of Beijing to estimate the individual intake fraction (iFi). iFi distributions are presented in microenvironments (traffic, work, home) for adults and children. The individual results are used to calculate the intake fraction for the children group and the adults group in the urban area of Beijing. The iF of PM2.5 for the whole population of these two groups in Beijing is 153 per million, which is significantly higher than those estimates in the United States (1-50 per million) and Mexico (23-120 per million). The iF of NOX is 70 per million, among which the intake in the traffic micro-environment ranks first compared to the iF in the home and office due to a high accumulation of NOX concentration in vehicles. PM2.5 and NOX intake fraction values from vehicle emissions in this study are from at least several times to one order of magnitude higher than those from other industry sources in China. This strongly suggests the health risk from vehicle emissions is significantly higher. Therefore, to protect human health, especially for the large number of people living in the cities of China, controlling vehicle emissions should be the highest priority.

  2. Intake retention fractions developed from models used in the determination of dose coefficients developed for ICRP publication 68--particulate inhalation.

    PubMed

    Potter, Charles A

    2002-11-01

    ICRP Publication 68 presents dose coefficients developed using systems of new models for the respiratory tract and metabolism of certain elements. The utility of these dose coefficients and associated models is limited without a method for calculating intake from bioassay results using the same models as in that publication. The calculation of a radionuclide intake requires values of expected fractions of the intake in bioassay samples collected at specific times after intake. The general system of models has been solved using a commercial software package and a method for solution of systems of first-order linear differential equations that uses eigenvectors and eigenvalues derived from the system of equations. The result of this work is a series of tables of fractions of acute inhalation intakes for different bioassay methods, times, and compound classes for intakes for those elements listed in ICRP Publication 68. The values in these tables can be used for intake calculations, development of bioassay frequencies, and development of action levels.

  3. Fractional Zinc Absorption for Men, Women, and Adolescents Is Overestimated in the Current Dietary Reference Intakes.

    PubMed

    Armah, Seth M

    2016-06-01

    The fractional zinc absorption values used in the current Dietary Reference Intakes (DRIs) for zinc were based on data from published studies. However, the inhibitory effect of phytate was underestimated because of the low phytate content of the diets in the studies used. The objective of this study was to estimate the fractional absorption of dietary zinc from the US diet by using 2 published algorithms. Nutrient intake data were obtained from the NHANES 2009-2010 and the corresponding Food Patterns Equivalents Database. Data were analyzed with the use of R software by taking into account the complex survey design. The International Zinc Nutrition Consultative Group (IZiNCG; Brown et al. Food Nutr Bull 2004;25:S99-203) and Miller et al. (Br J Nutr 2013;109:695-700) models were used to estimate zinc absorption. Geometric means (95% CIs) of zinc absorption for all subjects were 30.1% (29.9%, 30.2%) or 31.3% (30.9%, 31.6%) with the use of the IZiNCG model and Miller et al. model, respectively. For men, women, and adolescents, absorption values obtained in this study with the use of the 2 models were 27.2%, 31.4%, and 30.1%, respectively, for the IZiNCG model and 28.0%, 33.0%, and 31.6%, respectively, for the Miller et al. model, compared with the 41%, 48%, and 40%, respectively, used in the current DRIs. For preadolescents, estimated absorption values (31.1% and 32.8% for the IZiNCG model and Miller et al. model, respectively) compare well with the conservative estimate of 30% used in the DRIs. When the new estimates of zinc absorption were applied to the current DRI values for men and women, the results suggest that the Estimated Average Requirement (EAR) and RDA for these groups need to be increased by nearly one-half of the current values in order to meet their requirements for absorbed zinc. These data suggest that zinc absorption is overestimated for men, women, and adolescents in the current DRI. Upward adjustments of the DRI for these groups are recommended.

  4. Numerical approach to differential equations of fractional order

    NASA Astrophysics Data System (ADS)

    Momani, Shaher; Odibat, Zaid

    2007-10-01

    In this paper, the variational iteration method and the Adomian decomposition method are implemented to give approximate solutions for linear and nonlinear systems of differential equations of fractional order. The two methods in applied mathematics can be used as alternative methods for obtaining analytic and approximate solutions for different types of differential equations. In these schemes, the solution takes the form of a convergent series with easily computable components. This paper presents a numerical comparison between the two methods for solving systems of fractional differential equations. Numerical results show that the two approaches are easy to implement and accurate when applied to differential equations of fractional order.

  5. An implicit RBF meshless approach for time fractional diffusion equations

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Gu, Y. T.; Zhuang, P.; Liu, F.; Nie, Y. F.

    2011-07-01

    This paper aims to develop an implicit meshless approach based on the radial basis function (RBF) for numerical simulation of time fractional diffusion equations. The meshless RBF interpolation is firstly briefed. The discrete equations for two-dimensional time fractional diffusion equation (FDE) are obtained by using the meshless RBF shape functions and the strong-forms of the time FDE. The stability and convergence of this meshless approach are discussed and theoretically proven. Numerical examples with different problem domains and different nodal distributions are studied to validate and investigate accuracy and efficiency of the newly developed meshless approach. It has proven that the present meshless formulation is very effective for modeling and simulation of fractional differential equations.

  6. Parameter estimation for fractional transport: A particle-tracking approach

    NASA Astrophysics Data System (ADS)

    Chakraborty, Paramita; Meerschaert, Mark M.; Lim, Chae Young

    2009-10-01

    Space-fractional advection-dispersion models provide attractive alternatives to the classical advection-dispersion equation for model applications that exhibit early arrivals and plume skewness. This paper develops a flexible method for estimating the parameters of the fractional transport model on the basis of spatial plume snapshots or temporal breakthrough curve data. A particle-tracking approach provides error bars for the parameter estimates and a general method for model fitting and comparison via optimal weighted least squares. A simple model of concentration variance, based on the particle-tracking approach, identifies the optimal weights.

  7. A Novel Effective Approach for Solving Fractional Nonlinear PDEs

    PubMed Central

    Aminikhah, Hossein; Malekzadeh, Nasrin; Rezazadeh, Hadi

    2014-01-01

    The present work introduces an effective modification of homotopy perturbation method for the solution of nonlinear time-fractional biological population model and a system of three nonlinear time-fractional partial differential equations. In this approach, the solution is considered a series expansion that converges to the nonlinear problem. The new approximate analytical procedure depends only on two iteratives. The analytical approximations to the solution are reliable and confirm the ability of the new homotopy perturbation method as an easy device for computing the solution of nonlinear equations. PMID:27419212

  8. A Novel Effective Approach for Solving Fractional Nonlinear PDEs.

    PubMed

    Aminikhah, Hossein; Malekzadeh, Nasrin; Rezazadeh, Hadi

    2014-01-01

    The present work introduces an effective modification of homotopy perturbation method for the solution of nonlinear time-fractional biological population model and a system of three nonlinear time-fractional partial differential equations. In this approach, the solution is considered a series expansion that converges to the nonlinear problem. The new approximate analytical procedure depends only on two iteratives. The analytical approximations to the solution are reliable and confirm the ability of the new homotopy perturbation method as an easy device for computing the solution of nonlinear equations.

  9. Intake fractions of primary conserved air pollutants emitted from on-road vehicles in the United States

    NASA Astrophysics Data System (ADS)

    Lobscheid, Agnes B.; Nazaroff, William W.; Spears, Michael; Horvath, Arpad; McKone, Thomas E.

    2012-12-01

    Vehicular air pollutant emissions are characterized by a high degree of spatial variability that is correlated with the distribution of people. The consequences of the spatial association between emissions and exposed populations have not been fully captured in lifecycle and other impact assessments. The intake fraction (iF) quantifies aggregate air-pollutant exposures attributable to sources. Utilizing source-receptor (S-R) relationships derived from the US Environmental Protection Agency's AERMOD steady-state plume model, we quantify the intake fraction of conserved pollutants emitted from on-road mobile sources and report here the first characterization across approximately 65,000 census tracts of the conterminous United States. Considering exposures out to 50 km from the source, the population-weighted mean iF is 8.6 parts per million (ppm). The population-weighted median generally increases with geographic scale, from 3.6 ppm for census tracts to 4.2 ppm for counties, and 5.1 ppm for states, while the population-weighted interquartile range (IQR) progressively narrows as geographic scale increases: 0.85-8.8 ppm for census tracts, 1.5-8.5 ppm for counties, and 3.2-7.5 ppm for states. Across the four US Census regions, the population weighted median iF varies from 2.2 ppm (South) to 7.5 ppm (West), and the census-tract IQR spans an order of magnitude in each region (2.1-17 ppm in the West; 0.55-6.9 ppm in the Midwest; 0.45-5.5 ppm in the South; and 1.8-18 ppm in the Northeast). The population-weighted mean intake fraction for populous urban counties is about two orders of magnitude greater than for sparsely populated rural counties. On a population-weighted average basis and considering the 50 km analysis range, 75% of the intake occurs in the same county as emissions.

  10. Impact assessment of biomass-based district heating systems in densely populated communities. Part I: Dynamic intake fraction methodology

    NASA Astrophysics Data System (ADS)

    Petrov, Olga; Bi, Xiaotao; Lau, Anthony

    2015-08-01

    This study contributes to the literature by proposing a novel, state-of-the-art approach to estimate incremental air quality and health impacts of proposed or installed district energy systems (DES), such as the growing biomass-based DES, on the immediately surrounding community where population density varies significantly during day as well as the micrometeorological conditions. Spatial and temporal dynamics of pollutant concentrations at sensitive receptors obtained from modeled actual source emissions, inclusion of site-specific terrain, land use and microclimatic characteristics, population density and breathing rates are examined based on their impacts on the exposure potential expressed by the intake fraction (iF). Overall, results revealed that when those parameters are changing, the increase of iF calculated based on average ambient concentrations at each receptor for the UBC campus for the day and night hours for September 2012, ranges from 6.2% to 43.0%: introducing actual spatial receptor distribution led to 43% increase of iF, combined spatial and population dynamics led to 11.3% increase of iF, while introducing temporal dynamics and varying breathing rates resulted in 6.2% and 21.4% increase in iF respectively, compared to the base case box model where receptors and population were treated as static and uniformly distributed across the modeling domain. It is thus essential to take into consideration temporal and spatial variations of atmospheric conditions and dispersion, population density and varying aspiration rates in accurately assessing the health impacts of DES located at densely populated urban communities.

  11. Composition of bacteria harvested from the liquid and solid fractions of the rumen of sheep as influenced by feed intake.

    PubMed

    Rodríguez, C A; González, J; Alvir, M R; Repetto, J L; Centeno, C; Lamrani, F

    2000-09-01

    A study was conducted to determine the effect of the feed intake on the chemical composition of bacteria associated with the solid (solid-associated bacteria; SAB) and liquid (liquid-associated bacteria; LAB) fractions of rumen digesta, the digestive passage kinetics and their relationships. Whole rumen contents were sampled after a period of continuous infusion of 15NH3 from four ruminally-cannulated wethers provided successively with a hay-concentrate diet (2 : 1 w/w on a DM basis) at two rates of feed intake: 40 and 80 g DM/kg body weight 0.75. SAB had a higher content of organic matter and total lipids (P < 0.001) and a similar N content as compared with LAB. The concentration of purines and 15N was lower (P = 0.011 and P < 0.001 respectively) in SAB than LAB, whereas the opposite was observed for the concentration of amino acids (mg/g DM; P = 0.031). An increase in feed intake produced an increase in the N (P = 0.034) and purine (P = 0.066) concentrations in bacteria and a decrease (P = 0.033) in their amino acid concentrations. Significant increases of rumen outflow rates of liquid and particles were also observed with increased feed intake. Rates of rumen outflow showed positive and negative linear relationships (P < 0.001) with the purine : N ratio and the proportion of amino acid on total N of bacteria respectively. SAB contained significantly higher proportions of leucine, isoleucine, lysine and phenylalanine and lower proportions of alanine, methionine and valine than LAB. The increase in feed intake also induced significant changes in the amino acid profile of bacteria, increasing arginine and methionine and decreasing alanine and glycine proportions. Results show that the outflow rate of rumen contents is a major factor in determining the proportion of nucleic acids and protein in rumen bacteria and explains some of the differences observed between LAB and SAB.

  12. Mathematical knowledge in teaching of fraction concepts using diagrammatical approach

    NASA Astrophysics Data System (ADS)

    Veloo, Palanisamy Kathir; Puteh, Marzita

    2017-05-01

    Teachers need various types of knowledge in order to deliver various fraction concepts at elementary level. In this paper, Balls' framework (2008) or, Mathematical Knowledge for Teaching (MKT) is used as benchmark guideline. This paper investigates and explores component of MKT knowledge among eight experienced teachers of the primary school. Data was collected using paper pencil test, interview and video recording. This paper, narrowed to teacher's knowledge and their practices while teaching of various fractions concepts using diagrammatical approach in present of MKT. The data gathered from teachers were analyzed using thematic analysis techniques. The results indicated that teachers lack various components of MKT knowledge as a proposal by various researchers and assumed that teaching as procedural more than enough due to lack of deep understanding of mathematics and the various types of MKT is not required due to the present of practices in the mathematics classroom.

  13. Correlations in a generalized elastic model: Fractional Langevin equation approach

    NASA Astrophysics Data System (ADS)

    Taloni, Alessandro; Chechkin, Aleksei; Klafter, Joseph

    2010-12-01

    The generalized elastic model (GEM) provides the evolution equation which governs the stochastic motion of several many-body systems in nature, such as polymers, membranes, and growing interfaces. On the other hand a probe (tracer) particle in these systems performs a fractional Brownian motion due to the spatial interactions with the other system’s components. The tracer’s anomalous dynamics can be described by a fractional Langevin equation (FLE) with a space-time correlated noise. We demonstrate that the description given in terms of GEM coincides with that furnished by the relative FLE, by showing that the correlation functions of the stochastic field obtained within the FLE framework agree with the corresponding quantities calculated from the GEM. Furthermore we show that the Fox H -function formalism appears to be very convenient to describe the correlation properties within the FLE approach.

  14. A partially coupled, fraction-by-fraction modelling approach to the subsurface migration of gasoline spills

    NASA Astrophysics Data System (ADS)

    Fagerlund, F.; Niemi, A.

    2007-01-01

    The subsurface spreading behaviour of gasoline, as well as several other common soil- and groundwater pollutants (e.g. diesel, creosote), is complicated by the fact that it is a mixture of hundreds of different constituents, behaving differently with respect to e.g. dissolution, volatilisation, adsorption and biodegradation. Especially for scenarios where the non-aqueous phase liquid (NAPL) phase is highly mobile, such as for sudden spills in connection with accidents, it is necessary to simultaneously analyse the migration of the NAPL and its individual components in order to assess risks and environmental impacts. Although a few fully coupled, multi-phase, multi-constituent models exist, such models are highly complex and may be time consuming to use. A new, somewhat simplified methodology for modelling the subsurface migration of gasoline while taking its multi-constituent nature into account is therefore introduced here. Constituents with similar properties are grouped together into eight fractions. The migration of each fraction in the aqueous and gaseous phases as well as adsorption is modelled separately using a single-constituent multi-phase flow model, while the movement of the free-phase gasoline is essentially the same for all fractions. The modelling is done stepwise to allow updating of the free-phase gasoline composition at certain time intervals. The output is the concentration of the eight different fractions in the aqueous, gaseous, free gasoline and solid phases with time. The approach is evaluated by comparing it to a fully coupled multi-phase, multi-constituent numerical simulator in the modelling of a typical accident-type spill scenario, based on a tanker accident in northern Sweden. Here the PCFF method produces results similar to those of the more sophisticated, fully coupled model. The benefit of the method is that it is easy to use and can be applied to any single-constituent multi-phase numerical simulator, which in turn may have

  15. Food intake monitoring: an acoustical approach to automated food intake activity detection and classification of consumed food.

    PubMed

    Päßler, Sebastian; Wolff, Matthias; Fischer, Wolf-Joachim

    2012-06-01

    Obesity and nutrition-related diseases are currently growing challenges for medicine. A precise and timesaving method for food intake monitoring is needed. For this purpose, an approach based on the classification of sounds produced during food intake is presented. Sounds are recorded non-invasively by miniature microphones in the outer ear canal. A database of 51 participants eating seven types of food and consuming one drink has been developed for algorithm development and model training. The database is labeled manually using a protocol with introductions for annotation. The annotation procedure is evaluated using Cohen's kappa coefficient. The food intake activity is detected by the comparison of the signal energy of in-ear sounds to environmental sounds recorded by a reference microphone. Hidden Markov models are used for the recognition of single chew or swallowing events. Intake cycles are modeled as event sequences in finite-state grammars. Classification of consumed food is realized by a finite-state grammar decoder based on the Viterbi algorithm. We achieved a detection accuracy of 83% and a food classification accuracy of 79% on a test set of 10% of all records. Our approach faces the need of monitoring the time and occurrence of eating. With differentiation of consumed food, a first step toward the goal of meal weight estimation is taken.

  16. An Alternative Approach to Understanding the Observed Positron Fraction

    NASA Astrophysics Data System (ADS)

    Israel, Martin H.

    2014-10-01

    Space-based observations by PAMELA (Adriani et al., Nature 458, 607, 2009), Fermi-LAT (Ackerman et al., Phys. Rev. Lett. 105, 01103, 2012), and AMS (Aguilar et al., Phys. Rev. Lett. 110, 141102, 2013) have demonstrated that the positron fraction (e+/total-e) increases with increasing energy above about 10 GeV. According to the propagation model for Galactic cosmic rays in widespread use (Moskalenko & Strong, Astrophys. J. 493, 693, 1998), the production of secondary positrons from interaction of cosmic-ray protons and heavier nuclei with the interstellar medium gives a generally falling positron fraction between 10 and 100 GeV, with secondary positrons accounting for only ˜20 % of the observed positron fraction at 100 GeV; so some other physical phenomena have been proposed to explain the data. An alternative approach to interpreting the positron observations is to consider these data as presenting an opportunity for re-examining models of Galactic cosmic-ray propagation. Following release of the PAMELA data, three groups published propagation models (Shaviv, et al., Phys. Rev. Lett. 103, 111302, 2009, Cowsik and Burch, Phys. Rev. D. 82, 023009, 2010, Katz et al., Mon. Not. R. Aston. Soc. 405, 1458 2010) in which the observed positron fraction is explained entirely by secondary positrons produced in the interstellar medium. In May of this year, stimulated by the AMS extension of the positron data to higher energy with excellent statistics, two of those groups presented further development of their calculations (Cowsik et al. 2013, Blum et al. 2013), again concluding that the observed positrons can be understood as secondaries. None of the authors of these five papers was registered for the 33rd International Cosmic Ray Conference (ICRC). Although I am not an author of any of these papers, I have some close familiarity with one of these recent papers, so the conference organizers invited me to bring this alternative approach to the attention of the conference. The

  17. A Fractional Variational Approach to the Fractional Basset-Type Equation

    NASA Astrophysics Data System (ADS)

    Baleanu, Dumitru; Garra, Roberto; Petras, Ivo

    2013-08-01

    In this paper we discuss an application of fractional variational calculus to the Basset-type fractional equations. It is well known that the unsteady motion of a sphere immersed in a Stokes fluid is described by an integro-differential equation involving derivative of real order. Here we study the inverse problem, i.e. we consider the problem from a Lagrangian point of view in the framework of fractional variational calculus. In this way we find an application of fractional variational methods to a classical physical model, finding a Basset-type fractional equation starting from a Lagrangian depending on derivatives of fractional order.

  18. Optimization of minoxidil microemulsions using fractional factorial design approach.

    PubMed

    Jaipakdee, Napaphak; Limpongsa, Ekapol; Pongjanyakul, Thaned

    2016-01-01

    The objective of this study was to apply fractional factorial and multi-response optimization designs using desirability function approach for developing topical microemulsions. Minoxidil (MX) was used as a model drug. Limonene was used as an oil phase. Based on solubility, Tween 20 and caprylocaproyl polyoxyl-8 glycerides were selected as surfactants, propylene glycol and ethanol were selected as co-solvent in aqueous phase. Experiments were performed according to a two-level fractional factorial design to evaluate the effects of independent variables: Tween 20 concentration in surfactant system (X1), surfactant concentration (X2), ethanol concentration in co-solvent system (X3), limonene concentration (X4) on MX solubility (Y1), permeation flux (Y2), lag time (Y3), deposition (Y4) of MX microemulsions. It was found that Y1 increased with increasing X3 and decreasing X2, X4; whereas Y2 increased with decreasing X1, X2 and increasing X3. While Y3 was not affected by these variables, Y4 increased with decreasing X1, X2. Three regression equations were obtained and calculated for predicted values of responses Y1, Y2 and Y4. The predicted values matched experimental values reasonably well with high determination coefficient. By using optimal desirability function, optimized microemulsion demonstrating the highest MX solubility, permeation flux and skin deposition was confirmed as low level of X1, X2 and X4 but high level of X3.

  19. Variations in automatically recorded rumination time as explained by variations in intake of dietary fractions and milk production, and between-cow variation.

    PubMed

    Byskov, M V; Nadeau, E; Johansson, B E O; Nørgaard, P

    2015-06-01

    Individual recording of rumination time (RT) is now possible in commercial dairy herds, through development of a microphone-based sensor, which is able to record RT by the sound of rumination activity. The objectives of this study were to examine the relationship between daily RT and intakes of different dietary fractions, the relationship between RT in minutes per kilogram of dry matter intake (DMI) and milk production, and to examine the variation in RT within and between mid-lactating dairy cows. Data from 3 production trials were used in which a total of 27 different diets were fed. The data contained 761, 290, and 203 daily recordings of RT, milk yield, milk components, DMI, and intake of dietary fractions recorded on 29, 26, and 24 Holstein and Swedish Red cows from trials 1, 2, and 3, respectively. The dietary fractions included forage neutral detergent fiber (NDF), concentrate NDF, crude protein, sugar, starch, and the remaining fraction represented by organic matter--(forage NDF+concentrate NDF+crude protein+sugar+starch). The relationship between the dietary fractions and RT was analyzed in 2 steps. In step 1, the dietary fractions, which were significantly related to RT, were selected and simultaneously checked for multicollinearity between the dietary components; in step 2, a multivariate model, including the effect of repeated measurements, the main effect of the selected dietary fractions from step 1, random effects of cow(trial) and trial, and information on breed, days in milk, and parity was used to analyze the relationship between RT and the selected dietary fractions. Relationships between RT in minutes per kilogram of DMI and milk yield and milk components were analyzed, using the same multivariate model as in step 2. Approximately 32% of the variation in daily RT could be explained by variations in intakes of the dietary fractions, whereas 48% of the total variation in RT was accounted for by individual variations between cows. Intakes of

  20. Caloric intake and Alzheimer's disease. Experimental approaches and therapeutic implications.

    PubMed

    Pasinetti, Giulio Maria; Zhao, Zhong; Qin, Weiping; Ho, Lap; Shrishailam, Yemul; Macgrogan, Donal; Ressmann, Wendy; Humala, Nelson; Liu, Xunxian; Romero, Carmen; Stetka, Breton; Chen, Linghong; Ksiezak-Reding, Hanna; Wang, Jun

    2007-01-01

    Alzheimer's disease (AD) is a rapidly growing public health concern with potentially devastating effects. Presently, there are no known cures or effective preventive strategies. While genetic factors are relevant in early-onset cases, they appear to play less of a role in late-onset sporadic AD cases, the most common form of AD. Due to the fact that the disease typically strikes very late in life, delaying symptoms could be as good as a cure for many people. For example, it is now widely accepted that if the onset of the disease could be delayed by even 5 years, the incidence could be cut in half. Both clinical and epidemiological evidence suggests that modification of lifestyle factors such as nutrition may prove crucial to AD management given the mounting experimental evidence suggesting that brain cells are remarkably responsive to "what somebody is doing". Among other nongenetic factors influencing AD, recent studies strongly support the evidence that caloric intake may play a role in the relative risk for AD clinical dementia. Indeed, the effect of diet in AD has been an area of research that has produced promising results, at least experimentally. Most importantly, as mechanistic pathways are defined and their biochemical functions scrutinized, the evidence supporting a direct link between nutrition and AD neuropathology continues to grow. Our work, as well as that of others, has recently resulted in the development of experimental dietary regimens that might promote, attenuate or even reverse features of AD. Most remarkably, while we found that high caloric intake based on saturated fat promotes AD type Beta-amyloidosis, conversely we found that dietary restriction based on reduced carbohydrate intake is able to prevent it. This evidence is very exciting and is, in part, consistent with current epidemiological studies suggesting that obesity and diabetes are associated with a >4-fold increased risk of developing AD. The clarification of the mechanisms

  1. Convergent approaches to determine an ecosystem's transpiration fraction

    NASA Astrophysics Data System (ADS)

    Berkelhammer, M.; Noone, D. C.; Wong, T. E.; Burns, S. P.; Knowles, J. F.; Kaushik, A.; Blanken, P. D.; Williams, M. W.

    2016-06-01

    The transpiration (T) fraction of total terrestrial evapotranspiration (ET), T/ET, can vary across ecosystems between 20-95% with a global average of ˜60%. The wide range may either reflect true heterogeneity between ecosystems and/or uncertainties in the techniques used to derive this property. Here we compared independent approaches to estimate T/ET at two needleleaf forested sites with a factor of 3 difference in leaf area index (LAI). The first method utilized water vapor isotope profiles and the second derived transpiration through its functional relationship with gross primary production. We found strong agreement between T/ET values from these two independent approaches although we noted a discrepancy at low vapor pressure deficits (VPD). We hypothesize that this divergence arises because stomatal conductance is independent of humidity at low VPD. Overall, we document significant synoptic-scale T/ET variability but minimal growing season-scale variability. This result indicates a high sensitivity of T/ET to passing weather but convergence toward a stable mean state, which is set by LAI. While changes in T/ET could emerge from a myriad of processes, including aboveground (LAI) or belowground (rooting depth) changes, there was only minimal interannual variability and no secular trend in our analysis of T/ET from the 15 year eddy covariance time series at Niwot Ridge. If the lack of trend observed here is apparent elsewhere, it suggests that the processes controlling the T and E fluxes are coupled in a way to maintain a stable ratio.

  2. An Activity Approach to Fractional Concepts, Monograph No. 5.

    ERIC Educational Resources Information Center

    Dirkse, Ronald; And Others

    This monograph focuses upon the teaching of fractional concepts. The introduction to fractional concepts is treated through sets, number lines, and area. Included are three diagnostic pretests, one of which can be administered to a nonreader. The major core of the monograph consists of 23 worksheets which can be removed for duplication. The…

  3. Analytical Approach for Nonlinear Partial Differential Equations of Fractional Order

    NASA Astrophysics Data System (ADS)

    Pradip, Roul

    2013-09-01

    The purpose of the paper is to present analytical and numerical solutions of a degenerate parabolic equation with time-fractional derivatives arising in the spatial diffusion of biological populations. The homotopy—perturbation method is employed for solving this class of equations, and the time-fractional derivatives are described in the sense of Caputo. Comparisons are made with those derived by Adomian's decomposition method, revealing that the homotopy perturbation method is more accurate and convenient than the Adomian's decomposition method. Furthermore, the results reveal that the approximate solution continuously depends on the time-fractional derivative and the proposed method incorporating the Caputo derivatives is a powerful and efficient technique for solving the fractional differential equations without requiring linearization or restrictive assumptions. The basis ideas presented in the paper can be further applied to solve other similar fractional partial differential equations.

  4. Exercise and Protein Intake: A Synergistic Approach against Sarcopenia.

    PubMed

    Martone, Anna Maria; Marzetti, Emanuele; Calvani, Riccardo; Picca, Anna; Tosato, Matteo; Santoro, Luca; Di Giorgio, Angela; Nesci, Antonio; Sisto, Alex; Santoliquido, Angelo; Landi, Francesco

    2017-01-01

    Sarcopenia, the age-dependent loss of muscle mass and function/strength, is increasingly recognized as a major risk factor for adverse outcomes in frail older people. As such, the skeletal muscle is a relevant target for interventions aimed at preventing or postponing the occurrence of negative health-related events in late life. The association among physical inactivity, insufficient intake of energy and protein, and poor muscle health in older adults suggests that physical exercise and targeted nutritional supplementation may offer substantial therapeutic gain against sarcopenia and its negative correlates. This view is supported by observational studies as well as by small-scale clinical trials. In this review, we summarize the available evidence on the beneficial effects of behavioral interventions on sarcopenia. We also briefly describe how the knowledge gathered so far has been used to design the "Sarcopenia and Physical fRailty IN older people: multicomponenT Treatment strategies" (SPRINTT) project. The randomized clinical trial conducted within SPRINTT will provide robust evidence on the effectiveness of exercise and nutrition at preventing negative outcomes associated with sarcopenia and physical frailty.

  5. A statistical approach for estimating the distribution of usual dietary intake to assess nutritionally at-risk populations based on the new Japanese Dietary Reference Intakes (DRIs).

    PubMed

    Ishiwaki, Asako; Yokoyama, Tetsuji; Fujii, Hiroko; Saito, Kyoko; Nozue, Miho; Yoshita, Katsushi; Yoshiike, Nobuo

    2007-08-01

    The health of individuals is not markedly affected by the nutrients ingested in a single day; rather it is influenced by dietary habits over a long period of time. However, it is impossible to survey usual intake directly because recording diet over a long period of time is burdensome for the subjects, so usual dietary intake is rarely measured directly. Instead, we estimated the distribution of selected nutrients in subjects' usual dietary intake using a statistical method (Best-Power method) described previously. And we assessed the proportion of nutritionally at-risk subjects in individual groups based on the new Japanese Dietary Reference Intakes (DRIs), the Estimated Average Requirement (EAR), or the tentative dietary goal for preventing life-style related diseases (DG) as cut-points. We collected the survey data from 208 men and 251 women, aged 50 to 69 y in 2004 and 2005. The survey was carried out on three non-consecutive days four times each year: in spring, summer, autumn, and winter. The distribution of nutrients in the usual intake was estimated from a dietary survey of 3 d using one-way analyses of variance. We found that the proportion of the population at risk for nutrient deficiency was overestimated in the 1-d intake distribution. On the other hand, the fraction that was nutritionally at-risk in terms of salt intake, according to DG as the cut-point, was underestimated in the 1-d intake distribution: 74.0% of men and 82.5% of women in the 1-d intake, and 90.5% and 93.2%, respectively, for the estimated usual intake adjusted for seasonal variation.

  6. Innovative approaches to estimate individual usual dietary intake in large-scale epidemiological studies.

    PubMed

    Conrad, Johanna; Nöthlings, Ute

    2017-02-06

    Valid estimation of usual dietary intake in epidemiological studies is a topic of present interest. The aim of the present paper is to review recent literature on innovative approaches focussing on: (1) the requirements to assess usual intake and (2) the application in large-scale settings. Recently, a number of technology-based self-administered tools have been developed, including short-term instruments such as web-based 24-h recalls, mobile food records or simple closed-ended questionnaires that assess the food intake of the previous 24 h. Due to their advantages in terms of feasibility and cost-effectiveness these tools may be superior to conventional assessment methods in large-scale settings. New statistical methods have been developed to combine dietary information from repeated 24-h dietary recalls and FFQ. Conceptually, these statistical methods presume that the usual food intake of a subject equals the probability of consuming a food on a given day, multiplied by the average amount of intake of that food on a typical consumption day. Repeated 24-h recalls from the same individual provide information on consumption probability and amount. In addition, the FFQ can add information on intake frequency of rarely consumed foods. It has been suggested that this combined approach may provide high-quality dietary information. A promising direction for estimation of usual intake in large-scale settings is the integration of both statistical methods and new technologies. Studies are warranted to assess the validity of estimated usual intake in comparison with biomarkers.

  7. A Study of Two-Term Unit Fraction Expansions via Geometric Approach

    ERIC Educational Resources Information Center

    Man, Yiu-Kwong

    2009-01-01

    In this article, we report a study of two-term unit fraction expansions using a geometric approach. It provides us insight on how to find all two-term unit fraction expansions and identify the property of the expansions with smallest maximal denominators, for a given unit fraction. These findings will be useful to lecturers or teachers involved in…

  8. A Study of Two-Term Unit Fraction Expansions via Geometric Approach

    ERIC Educational Resources Information Center

    Man, Yiu-Kwong

    2009-01-01

    In this article, we report a study of two-term unit fraction expansions using a geometric approach. It provides us insight on how to find all two-term unit fraction expansions and identify the property of the expansions with smallest maximal denominators, for a given unit fraction. These findings will be useful to lecturers or teachers involved in…

  9. A Small-Changes Approach Reduces Energy Intake in Free-Living Humans

    PubMed Central

    Stroebele, Nanette; de Castro, John M.; Stuht, Jennifer; Catenacci, Vicki; Wyatt, Holly R.; Hill, James O.

    2010-01-01

    Objective America On the Move (AOM) is a national weight gain prevention initiative that promotes small lifestyle changes by increasing walking by 2000 steps/day and reducing energy intake by about 100 kcal/day. The study’s intent was to determine the impact of these small changes recommendations on steps/day and energy intake. Methods In this cross-sectional study, food and fluid intake and physical activity in 116 healthy overweight adults (BMI: 25–36 kg/m2; age: 18–60y) was compared between a non-intervention and an intervention week using diet diaries and pedometers. The major outcomes were steps/day, daily caloric intake, macronutrient intake and meal size. Within subject ANOVAs were conducted to compare results between intervention and non-intervention weeks. Results Total energy intake was lower during intervention week than non-intervention week (P < .01), including macronutrient contents (all P’s < .01), meal size (P < .01), consumption of sugar (P < .01), sugared sodas (P < .01) and sodium (P < .01). Steps/day were higher during intervention week than non-intervention week (P < .01). Conclusions The results support previous research showing that the message to increase steps/day results in an increase in physical activity. The results demonstrate for the first time that the message to reduce intake by 100 kcal/day does actually result in a lower intake in the short term. People seem to be able to make positive changes in diet and physical activity in response to these messages. If these small changes can be sustained, this approach could be effective in preventing further weight gain in the population. PMID:19571162

  10. Dietary intake of c9,t11-conjugated linoleic acid correlates with its concentration in plasma lipid fractions of men but not women.

    PubMed

    Ritzenthaler, Kristin L; Shahin, Alam M; Shultz, Terry D; Dasgupta, Nairanjana; McGuire, Mark A; McGuire, Michelle K

    2012-09-01

    The c9,t11-18:2 isomer of conjugated linoleic acid (c9,t11-CLA) represents the main dietary CLA form with putative health benefits. Whereas CLA intake influences the tissue CLA concentration, little is known about the association between dietary CLA and the CLA content of plasma lipid fractions. This study was designed to document fasting and nonfasting plasma c9,t11-CLA concentrations in a population of free-living adults (n = 94) and relate these concentrations to c9,t11-CLA intake. We also determined the c9,t11-CLA content of the primary plasma lipid fractions in a subset (n = 50) of our participants, related these to c9,t11-CLA intake, and determined whether c9,t11-CLA intake or plasma c9,t11-CLA was correlated with plasma cholesterol. Mean fasting plasma c9,t11-CLA concentrations were 0.46 ± 0.01 and 0.54 ± 0.01% (wt:wt) of total fatty acids for men and women, respectively (P < 0.05); nonfasting concentrations were 0.28 ± 0.01 and 0.38 ± 0.01% of total fatty acids, respectively (P < 0.001). All major esterified plasma lipid fractions contained c9,t11-CLA; TG had the highest percentages. In men, c9,t11-CLA intake correlated (r = 0.47; P < 0.05) with TG c9,t11-CLA content, suggesting that TG c9,t11-CLA may serve as a biomarker for c9,t11-CLA intake. In females, there were no correlations between c9,t11-CLA intake and the c9,t11-CLA content of any esterified plasma lipid fraction. In neither sex was there a relation between dietary c9,t11-CLA or plasma c9,t11-CLA concentration and circulating lipoprotein cholesterol concentration. The influence of sex on circulating c9,t11-CLA content and further validation of biomarkers of c9,t11-CLA intake warrant further investigation.

  11. New Approach for Fractioning Metal Compounds Studies in Soils

    NASA Astrophysics Data System (ADS)

    Minkina, Tatiana; Motuzova, Galina; Mandzhieva, Saglara; Bauer, Tatiana; Burachevskaya, Marina; Sushkova, Svetlana; Nevidomskaya, Dina; Kalinitchenko, Valeriy

    2016-04-01

    A combined approach for fractioning metal compounds in soils on the basis of sequential (Tessier, 1979) and parallel extractions (1 N NH4Ac, pH 8; 1% EDTA in NH4Ac; and 1N HCl) is proposed. Metal compounds in sequential and parallel extracts are grouped according to the strength of their bonds with soil components. A given group includes metal compounds with similar strengths of bonds and, hence, with similar migration capacities. The groups of firmly and loosely bound metal compounds can be distinguished. This approach has been used to assess the group composition of Zn, Cu, and Pb compounds in an ordinary chernozem and its changes upon the soil contamination with metals. Contamination of an ordinary chernozem from Rostov oblast with heavy metals caused a disturbance of the natural ratios between the metal compounds. In the natural soil, firmly bound metals predominate (88-95%of the total content), which is mainly caused by the fixation of metals in lattices of silicate minerals (56-83%of the total content). The mobility of the metals in the natural soil is low (5-12%) and is mainly related to metal compounds loosely bound with the soil carbonates. Upon the soil contamination with metals (application rates of 100-300 mg/kg), the content of all the metal compounds increases, but the ratio between them shifts towards a higher portion of the potentially mobile metal compounds (up to 30-40% of the bulk contents of the metals). Organic substances and non-silicate Fe, Al, and Mn minerals become the main carriers of the firmly and loosely bound metals. The strengths of their bonds with Cu, Pb, and Zn differ. Lead in the studied chernozems is mainly fixed in a loosely bound form with organic matter, whereas copper and zinc are fixed both by the organic matter and by the non-silicate Fe, Al, and Mn compounds. Firm fixation of the applied Cu and Pb is mainly ensured by the soil organic matter and non-silicate minerals, whereas firm fixation of Zn is mainly due to non

  12. Fractional System Identification: An Approach Using Continuous Order-Distributions

    NASA Technical Reports Server (NTRS)

    Hartley, Tom T.; Lorenzo, Carl F.

    1999-01-01

    This paper discusses the identification of fractional- and integer-order systems using the concept of continuous order-distribution. Based on the ability to define systems using continuous order-distributions, it is shown that frequency domain system identification can be performed using least squares techniques after discretizing the order-distribution.

  13. Fraction Calculation--A Didactic Approach to Constructing Mathematical Networks.

    ERIC Educational Resources Information Center

    Steiner, Gerhard F.; Stoecklin, Markus

    1997-01-01

    Thirty-eight sixth graders were trained in fraction calculation through progressive transformation dialectics (PT) whereas a control group of 38 was taught through a traditional mathematics education framework. The PT group, encouraged to form network-type knowledge representations, performed better on problems that required more than mere…

  14. An Arts-Based Approach to Teaching Fractions

    ERIC Educational Resources Information Center

    Goral, Mary Barr; Wiest, Lynda R.

    2007-01-01

    Most teachers' classroom experiences likely confirm that "fractions have always represented a considerable challenge for students, even into the middle grades" (Van de Walle 2004, p. 242). Because both movement and music enhance learning and retention of academic content (Jenson 2000), we developed a series of lessons that integrated kinesthetic…

  15. The influence of street layouts and viaduct settings on daily carbon monoxide exposure and intake fraction in idealized urban canyons.

    PubMed

    Hang, Jian; Luo, Zhiwen; Wang, Xuemei; He, Lejian; Wang, Baomin; Zhu, Wei

    2017-01-01

    Environmental concerns have been raised on the adverse health effects of vehicle emissions in micro-scale traffic-crowded street canyons, especially for pedestrians and residents living in near-road buildings. Viaduct design is sometimes used to improve transportation efficiency but possibly affects urban airflow and the resultant exposure risk, which have been rarely investigated so far. The personal intake fraction (P_IF) is defined as the average fraction of total emissions that is inhaled by each person of a population (1 ppm = 1 × 10(-6)), and the daily carbon monoxide (CO) pollutant exposure (Et) is estimated by multiplying the average concentration of a specific micro-environment within one day. As a novelty, by considering time activity patterns and breathing rates in various micro-environments for three age groups, this paper introduces IF and Et into computational fluid dynamic (CFD) simulation to quantify the impacts of street layouts (street width/building height W/H = 1, 1.5, 2), source location, viaduct settings and noise barriers on the source-exposure correlation when realistic CO sources are defined. Narrower streets experience larger P_IF (1.51-5.21 ppm) and CO exposure, and leeward-side buildings always attain higher vehicular pollutant exposure than windward-side. Cases with a viaduct experience smaller P_IF (3.25-1.46 ppm) than cases without a viaduct (P_IF = 5.21-2.23 ppm) if the single ground-level CO source is elevated onto the viaduct. With two CO sources (both ground-level and viaduct-level), daily CO exposure rises 2.80-3.33 times but P_IF only change slightly. Noise barriers above a viaduct raise concentration between barriers, but slightly reduce vehicular exposure in near-road buildings. Because people spend most of their time indoors, vehicular pollutant exposure within near-road buildings can be 6-9 times that at pedestrian level. Although further studies are still required to provide practical guidelines, this paper

  16. Assessment of monosodium glutamate (MSG) intake in a rural Thai community: questioning the methodological approach

    PubMed Central

    2013-01-01

    We examined the methodological approach to the assessment of monosodium glutamate intake. The high carbohydrate and low fat consumption characteristic of this study population would be conducive to the development of metabolic syndrome. However, anomalies in the assessment of dietary information limits conclusion to a causal link of monosodium glutamate to metabolic syndrome and overweight because the study lacks data on the main dietary patterns of consumption. Given the current paucity of data from human studies on monosodium glutamate intake and risk, more studies with robust methodology are required to assess causal links to disease. PMID:23890489

  17. Rapid Analysis of 239,238Pu, 241Am, and 90Sr for Nasal Smear Samples in Radiation Emergency and Evaluation of Intake Retention Fraction.

    PubMed

    Yoon, Seokwon; Ha, Wi-Ho; Park, Sunhoo; Lee, Seung-Sook; Jin, Young-Woo

    2017-05-01

    The efficiency of the nasal smear method was reviewed to perform a method of sample collection, analysis and initial dose estimation. The screening method of alpha-emitting radionuclides using chemical separation and alpha spectrometry was also studied. To rapidly conduct the appropriate response to victims, special monitoring for Pu, Am, and Sr using sequential analysis was established, and the method was successfully validated through participation in an international inter-comparison program. The duration of the analysis method was evaluated with regard to application in emergency situations because of its relatively rapid treatment and counting time. The intake retention fraction was calculated and evaluated to review the characteristics of each radionuclide in the anterior nasal passage of the extra-thoracic region. No large difference was observed among the four radionuclides. However, the values of the intake retention fraction were affected by age groups because of the different respiratory rates. The effects of the Y ingrowth and particle size were also discussed.

  18. An Improved Heaviside Approach to Partial Fraction Expansion and Its Applications

    ERIC Educational Resources Information Center

    Man, Yiu-Kwong

    2009-01-01

    In this note, we present an improved Heaviside approach to compute the partial fraction expansions of proper rational functions. This method uses synthetic divisions to determine the unknown partial fraction coefficients successively, without the need to use differentiation or to solve a system of linear equations. Examples of its applications in…

  19. A novel approach to ablative fractional treatment of mature thermal burn scars.

    PubMed

    Bowen, Robert E

    2010-04-01

    This report details the use of a fractionated ablative Er:YAG laser in treating two cases of thermal burn injuries using a novel approach which matches the energy required to the depth of the burn scar. This method is termed "selective objective fractional technique (SOFT)".

  20. An Improved Heaviside Approach to Partial Fraction Expansion and Its Applications

    ERIC Educational Resources Information Center

    Man, Yiu-Kwong

    2009-01-01

    In this note, we present an improved Heaviside approach to compute the partial fraction expansions of proper rational functions. This method uses synthetic divisions to determine the unknown partial fraction coefficients successively, without the need to use differentiation or to solve a system of linear equations. Examples of its applications in…

  1. Exposure assessment for pesticide intake from multiple food products: a Bayesian latent-variable approach.

    PubMed

    Chatterjee, Ayona; Horgan, Graham; Theobald, Chris

    2008-12-01

    Pesticide risk assessment for food products involves combining information from consumption and concentration data sets to estimate a distribution for the pesticide intake in a human population. Using this distribution one can obtain probabilities of individuals exceeding specified levels of pesticide intake. In this article, we present a probabilistic, Bayesian approach to modeling the daily consumptions of the pesticide Iprodione though multiple food products. Modeling data on food consumption and pesticide concentration poses a variety of problems, such as the large proportions of consumptions and concentrations that are recorded as zero, and correlation between the consumptions of different foods. We consider daily food consumption data from the Netherlands National Food Consumption Survey and concentration data collected by the Netherlands Ministry of Agriculture. We develop a multivariate latent-Gaussian model for the consumption data that allows for correlated intakes between products. For the concentration data, we propose a univariate latent-t model. We then combine predicted consumptions and concentrations from these models to obtain a distribution for individual daily Iprodione exposure. The latent-variable models allow for both skewness and large numbers of zeros in the consumption and concentration data. The use of a probabilistic approach is intended to yield more robust estimates of high percentiles of the exposure distribution than an empirical approach. Bayesian inference is used to facilitate the treatment of data with a complex structure.

  2. Targeting implicit approach reactions to snack food in children: Effects on intake.

    PubMed

    Folkvord, Frans; Veling, Harm; Hoeken, Hans

    2016-08-01

    Implicit approach reactions to energy-dense snack food can facilitate unhealthy eating in children. Therefore, an experiment was conducted to test whether modifying implicit reactions to snack food by means of a go/no-go task can reduce consumption of this food. The effectiveness of this intervention on actual snack intake after exposure to a food or a control advertisement was tested. Children (133; age range = 7-10 years) played an advergame promoting either energy-dense food or nonfood products. Subsequently, children conducted either a go/no-go food task in which the advertised food was consistently associated with no-go cues, or a go/no-go control task in which colored circles were consistently associated with no-go cues. Afterward, they could eat the advertised food and a new food. Candy intake was weighed and caloric intake was determined. Results show that children who performed the go/no-go food task consumed significantly and considerably fewer calories (34%) than the children who carried out the control task. No main effect of type of advertisement was found. Furthermore, the effect of the go/no-go food task was similar after each type of advertisement, similar for advertised and new foods, and was significant for both girls and boys. Targeting implicit reactions to high-energy snacks proved effective in decreasing intake of snacks in children. Furthermore, the previously reported stimulating effect of food promoting advergames on intake may disappear when a short cognitive task is presented directly after the game. Future work should evaluate the clinical implications of these findings. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  3. Urinary Biomarkers of Whole Grain Wheat Intake Identified by Non-targeted and Targeted Metabolomics Approaches

    PubMed Central

    Zhu, Yingdong; Wang, Pei; Sha, Wei; Sang, Shengmin

    2016-01-01

    Mounting evidence suggests that whole grain (WG) intake plays an important role in chronic disease prevention. However, numerous human studies have failed to produce clear-cut conclusions on this topic. Here, a combination of non-targeted and targeted metabolomics approaches, together with kinetic studies, was used to investigate biomarkers of WG wheat intake and further explore the diet-disease associations. Via these integrated approaches, forty-one compounds were identified as the most discriminating endogenous metabolites after WG versus refined grain (RG) wheat bread consumption. The corresponding biological assessment of these endogenous changes suggests that, in contrast to RG consumption, WG wheat consumption may facilitate antioxidant defense systems and moderate the risk factors of cancer, cardiovascular diseases, and other chronic diseases. A panel of urinary markers consisting of seven alkylresorcinol metabolites and five benzoxazinoid derivatives as specific biomarkers, as well as five phenolic acid derivatives, was also established to cover multiple time points and longer time periods for correctly and objectively monitoring WG wheat intake. Through these findings, we have established a comprehensive biomarker pool to better assess WG wheat consumption, and to monitor the endogenous changes that are linked to health effects of WG wheat consumption. PMID:27805021

  4. An effective analytic approach for solving nonlinear fractional partial differential equations

    NASA Astrophysics Data System (ADS)

    Ma, Junchi; Zhang, Xiaolong; Liang, Songxin

    2016-08-01

    Nonlinear fractional differential equations are widely used for modelling problems in applied mathematics. A new analytic approach with two parameters c1 and c2 is first proposed for solving nonlinear fractional partial differential equations. These parameters are used to improve the accuracy of the resulting series approximations. It turns out that much more accurate series approximations are obtained by choosing proper values of c1 and c2. To demonstrate the applicability and effectiveness of the new method, two typical fractional partial differential equations, the nonlinear gas dynamics equation and the nonlinear KdV-Burgers equation, are solved.

  5. Mercury tissue residue approach in Chironomus riparius: Involvement of toxicokinetics and comparison of subcellular fractionation methods.

    PubMed

    Gimbert, Frédéric; Geffard, Alain; Guédron, Stéphane; Dominik, Janusz; Ferrari, Benoit J D

    2016-02-01

    Along with the growing body of evidence that total internal concentration is not a good indicator of toxicity, the Critical Body Residue (CBR) approach recently evolved into the Tissue Residue Approach (TRA) which considers the biologically active portion of metal that is available to contribute to the toxicity at sites of toxic action. For that purpose, we examined total mercury (Hg) bioaccumulation and subcellular fractionation kinetics in fourth stage larvae of the midge Chironomus riparius during a four-day laboratory exposure to Hg-spiked sediments and water. The debris (including exoskeleton, gut contents and cellular debris), granule and organelle fractions accounted only for about 10% of the Hg taken up, whereas Hg concentrations in the entire cytosolic fraction rapidly increased to approach steady-state. Within this fraction, Hg compartmentalization to metallothionein-like proteins (MTLP) and heat-sensitive proteins (HSP), consisting mostly of enzymes, was assessed in a comparative manner by two methodologies based on heat-treatment and centrifugation (HT&C method) or size exclusion chromatography separation (SECS method). The low Hg recoveries obtained with the HT&C method prevented accurate analysis of the cytosolic Hg fractionation by this approach. According to the SECS methodology, the Hg-bound MTLP fraction increased linearly over the exposure duration and sequestered a third of the Hg flux entering the cytosol. In contrast, the HSP fraction progressively saturated leading to Hg excretion and physiological impairments. This work highlights several methodological and biological aspects to improve our understanding of Hg toxicological bioavailability in aquatic invertebrates. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. New approach for exact solutions of time fractional Cahn-Allen equation and time fractional Phi-4 equation

    NASA Astrophysics Data System (ADS)

    Tariq, Hira; Akram, Ghazala

    2017-05-01

    In this article, new exact analytical solutions of some nonlinear evolution equations (NLEEs) arising in science, engineering and mathematical physics, namely time fractional Cahn-Allen equation and time fractional Phi-4 equation are developed using tanh method by means of fractional complex transform. The obtained results are demonstrated by graphs for the new solutions.

  7. A metabolite profiling approach to identify biomarkers of flavonoid intake in humans.

    PubMed

    Loke, Wai Mun; Jenner, Andrew M; Proudfoot, Julie M; McKinley, Allan J; Hodgson, Jonathan M; Halliwell, Barry; Croft, Kevin D

    2009-12-01

    Flavonoids are phytochemicals that are widespread in the human diet. Despite limitations in their bioavailability, experimental and epidemiological data suggest health benefits of flavonoid consumption. Valid biomarkers of flavonoid intake may be useful for estimating exposure in a range of settings. However, to date, few useful flavonoid biomarkers have been identified. In this study, we used a metabolite profiling approach to examine the aromatic and phenolic profile of plasma and urine of healthy men after oral consumption of 200 mg of the pure flavonoids, quercetin, (-)-epicatechin, and epigallocatechin gallate, which represent major flavonoid constituents in the diet. Following enzymatic hydrolysis, 71 aromatic compounds were quantified in plasma and urine at 2 and 5 h, respectively, after flavonoid ingestion. Plasma concentrations of different aromatic compounds ranged widely, from 0.01 to 10 micromol/L, with variation among volunteers. None of the aromatic compounds was significantly elevated in plasma 2 h after consumption of either flavonoid compared with water placebo. This indicates that flavonoid-derived aromatic compounds are not responsible for the acute physiological effects reported within 2 h in previous human intervention studies involving flavonoids or flavonoid-rich food consumption. These effects are more likely due to absorption of the intact flavonoid. Our urine analysis suggested that urinary 4-ethylphenol, benzoic acid, and 4-ethylbenzoic acid may be potential biomarkers of quercetin intake and 1,3,5-trimethoxybenzene, 4-O-methylgallic acid, 3-O-methylgallic acid, and gallic acid may be potential markers of epigallocatechin gallate intake. Potential biomarkers of (-)-epicatechin were not identified. These urinary biomarkers may provide an accurate indication of flavonoid exposure.

  8. Effect of Cuisenaire Rods' Approach on Some Nigeria Primary Pupils' Achievement in Decimal Fractions

    ERIC Educational Resources Information Center

    Kurumeh, M. S. C.; Achor, E. E.

    2008-01-01

    This study determined the effect of Cuisenaire Rods' approach on some Nigeria primary pupils' achievement in decimal fractions. Three hypotheses guided the study. A total of 200 Primary six pupils (that is, 6th grade) from randomly selected schools in Makurdi metropolis of Benue State of Nigeria served as the sample for the study. A Mathematics…

  9. Effect of Cuisenaire Rods' Approach on Some Nigeria Primary Pupils' Achievement in Decimal Fractions

    ERIC Educational Resources Information Center

    Kurumeh, M. S. C.; Achor, E. E.

    2008-01-01

    This study determined the effect of Cuisenaire Rods' approach on some Nigeria primary pupils' achievement in decimal fractions. Three hypotheses guided the study. A total of 200 Primary six pupils (that is, 6th grade) from randomly selected schools in Makurdi metropolis of Benue State of Nigeria served as the sample for the study. A Mathematics…

  10. A digital intake approach in specialized mental health care: study protocol of a cluster randomised controlled trial.

    PubMed

    Metz, Margot J; Elfeddali, Iman; Krol, David G H; Veerbeek, Marjolein A; de Beurs, Edwin; Beekman, Aartjan T F; van der Feltz-Cornelis, Christina M

    2017-03-07

    Enhancing patient participation is becoming increasingly important in mental health care as patients use to have a dependent, inactive role and nonadherence to treatment is a regular problem. Research shows promising results of initiatives stimulating patient participation in partnership with their clinicians. However, few initiatives targeting both patients' and clinicians' behaviour have been evaluated in randomised trials (RCT). Therefore, in GGz Breburg, a specialized mental health institution, a digital intake approach was developed aimed at exploring treatment needs, expectations and preferences of patients intended to prepare patients for the intake consultations. Subsequently, patients and clinicians discuss this information during intake consultations and make shared decisions about options in treatment. The aim of this trial is to test the efficacy of this new digital intake approach facilitated by Routine Outcome Monitoring (ROM), peer support and training of clinicians as compared to the intake as usual. The primary outcome is decisional conflict about choices in treatment. Secondary outcomes focus on patient participation, shared decision making, working alliance, adherence to treatment and clinical outcomes. This article presents the study protocol of a cluster-randomised controlled trial in four outpatient departments for adults with depression, anxiety and personality disorders, working in two different regions. Randomisation is done between two similar intake-teams within each department. In the four intervention teams the new intake approach is implemented. The four control teams apply the intake as usual and will implement the new approach after the completion of the study. In total 176 patients are projected to participate in the study. Data collection will be at baseline, and at two weeks and two months after the intake. This study will potentially demonstrate the efficacy of the new digital intake approach in mental health care in terms of the

  11. Dependence of intake fraction on release location in a multi-media framework: A case study of four contaminants in North America

    SciTech Connect

    MacLeod, Matthew; Bennett, Deborah H.; Perem, Merike; Maddalena, Randy L.; M cKone, Thomas E.; Mackay, Don

    2003-03-01

    The extent of human exposure to persistent anthropogenic environmental contaminants is a complex function of the amount of chemical emitted, its physico-chemical properties and reactivity, the nature of the environment, and the characteristics of the pathways for human exposure, such as inhalation, intake of food and water and dermal contact. For some chemicals, the location of emissions relative to areas of high population density or intense food production may also be an important factor. The relative importance of these variables is explored using the regionally segmented BETR North America contaminant fate model and data for food production patterns and population density for North America. The model is applied to four contaminants emitted to air: benzene, carbon tetrachloride, benzo[a]pyrene and 2,3,7,8-tetrachlorodibenzo dioxin. The total continental intake fraction (iF), relating exposure quantity to emission quantity, is employed as a metric for assessing population exposure to environmental contaminants. The results show that the use of continentally averaged parameters for population density and food production provides an accurate estimate of the median of iF calculated for emissions in individual regions, however iF can range from this median by up to 3 orders of magnitude, especially for chemicals transferred to humans through the food pathway. The location of population relative to food production and emissions of chemicals are important variables that should be considered in assessing the public health implications of chemical emissions.

  12. Bioinformatics Approaches for Fetal DNA Fraction Estimation in Noninvasive Prenatal Testing

    PubMed Central

    Peng, Xianlu Laura; Jiang, Peiyong

    2017-01-01

    The discovery of cell-free fetal DNA molecules in plasma of pregnant women has created a paradigm shift in noninvasive prenatal testing (NIPT). Circulating cell-free DNA in maternal plasma has been increasingly recognized as an important proxy to detect fetal abnormalities in a noninvasive manner. A variety of approaches for NIPT using next-generation sequencing have been developed, which have been rapidly transforming clinical practices nowadays. In such approaches, the fetal DNA fraction is a pivotal parameter governing the overall performance and guaranteeing the proper clinical interpretation of testing results. In this review, we describe the current bioinformatics approaches developed for estimating the fetal DNA fraction and discuss their pros and cons. PMID:28230760

  13. Bioinformatics Approaches for Fetal DNA Fraction Estimation in Noninvasive Prenatal Testing.

    PubMed

    Peng, Xianlu Laura; Jiang, Peiyong

    2017-02-20

    The discovery of cell-free fetal DNA molecules in plasma of pregnant women has created a paradigm shift in noninvasive prenatal testing (NIPT). Circulating cell-free DNA in maternal plasma has been increasingly recognized as an important proxy to detect fetal abnormalities in a noninvasive manner. A variety of approaches for NIPT using next-generation sequencing have been developed, which have been rapidly transforming clinical practices nowadays. In such approaches, the fetal DNA fraction is a pivotal parameter governing the overall performance and guaranteeing the proper clinical interpretation of testing results. In this review, we describe the current bioinformatics approaches developed for estimating the fetal DNA fraction and discuss their pros and cons.

  14. A Markov decision process approach to temporal modulation of dose fractions in radiation therapy planning.

    PubMed

    Kim, M; Ghate, A; Phillips, M H

    2009-07-21

    The current state of the art in cancer treatment by radiation optimizes beam intensity spatially such that tumors receive high dose radiation whereas damage to nearby healthy tissues is minimized. It is common practice to deliver the radiation over several weeks, where the daily dose is a small constant fraction of the total planned. Such a 'fractionation schedule' is based on traditional models of radiobiological response where normal tissue cells possess the ability to repair sublethal damage done by radiation. This capability is significantly less prominent in tumors. Recent advances in quantitative functional imaging and biological markers are providing new opportunities to measure patient response to radiation over the treatment course. This opens the door for designing fractionation schedules that take into account the patient's cumulative response to radiation up to a particular treatment day in determining the fraction on that day. We propose a novel approach that, for the first time, mathematically explores the benefits of such fractionation schemes. This is achieved by building a stylistic Markov decision process (MDP) model, which incorporates some key features of the problem through intuitive choices of state and action spaces, as well as transition probability and reward functions. The structure of optimal policies for this MDP model is explored through several simple numerical examples.

  15. Faecal nitrogen excretion as an approach to estimate forage intake of wethers.

    PubMed

    Kozloski, G V; Oliveira, L; Poli, C H E C; Azevedo, E B; David, D B; Ribeiro Filho, H M N; Collet, S G

    2014-08-01

    Data from twenty-two digestibility trials were compiled to examine the relationship between faecal N concentration and organic matter (OM) digestibility (OMD), and between faecal N excretion and OM intake (OMI) by wethers fed tropical or temperate forages alone or with supplements. Data set was grouped by diet type as follows: only tropical grass (n = 204), only temperate grass (n = 160), tropical grass plus supplement (n = 216), temperate grass plus supplement (n = 48), tropical grass plus tropical legume (n = 60) and temperate grass with ruminal infusion of tannins (n = 16). Positive correlation between OMD and either total faecal N concentration (Nfc, % of OM) or metabolic faecal N concentration (Nmetfc, % of OM) was significant for most diet types. Exceptions were the diet that included a tropical legume, where both relationships were negative, and the diet that included tannin extract, where the correlation between OMD and Nfc was not significant. Pearson correlation and linear regressions between OM intake (OMI, g/day) and faecal N excretion (Nf, g/day) were significant for all diet types. When OMI was estimated from the OM faecal excretion and Nfc-based OMD values, the linear comparison between observed and estimated OMI values showed intercept different from 0 and slope different from 1. When OMI was estimated using the Nf-based linear regressions, the linear comparison between observed and estimated OMI values showed neither intercept different from 0 nor slope different from 1. Both linear comparisons showed similar R(2) values (i.e. 0.78 vs. 0.79). In conclusion, linear equations are suitable for directly estimating OM intake by wethers, fed only forage or forage plus supplements, from the amount of N excreted in faeces. The use of this approach in experiments with grazing wethers has the advantage of accounting for individual variations in diet selection and digestion processes and precludes the use of techniques to estimate forage

  16. Langevin approach for stochastic Hodgkin-Huxley dynamics with discretization of channel open fraction

    NASA Astrophysics Data System (ADS)

    Huang, Yandong; Rüdiger, Sten; Shuai, Jianwei

    2013-12-01

    The random opening and closing of ion channels establishes channel noise, which can be approximated and included into stochastic differential equations (Langevin approach). The Langevin approach is often incorporated to model stochastic ion channel dynamics for systems with a large number of channels. Here, we introduce a discretization procedure of a channel-based Langevin approach to simulate the stochastic channel dynamics with small and intermediate numbers of channels. We show that our Langevin approach with discrete channel open fractions can give a good approximation of the original Markov dynamics even for only 10 K channels. We suggest that the better approximation by the discretized Langevin approach originates from the improved representation of events that trigger action potentials.

  17. Biallelic and triallelic approaches of 5-HTTLPR polymorphism are associated with food intake and nutritional status in childhood.

    PubMed

    Miranda, Raquel C K; Genro, Júlia P; Campagnolo, Paula D B; Mattevi, Vanessa S; Vitolo, Márcia R; Almeida, Silvana

    2017-05-01

    The 5-HTT gene contains polymorphisms in its promoter region, the insertion/deletion (5-HTTLPR) that creates long (L) or short (S) alleles (biallelic approach) and SNP (rs25531) in L allele (triallelic approach). The aim of this study is to investigate the association of the 5-HTTLPR and rs25531 polymorphisms, using bi- and triallelic approach, with dietary intake and anthropometric parameters in children followed until 8 years old. The sample were 303 children who were recruited at birth and examined at 1, 3 to 4 and 7 to 8 years old. The polymorphisms were analyzed by polymerase-chain-reaction-based methods. In the biallelic approach, children with the S/S genotype presented a higher body mass index Z-score in the three developmental stages and higher sum of skinfolds at 3 to 4 and 7 to 8 years old than carriers of the L allele. In the triallelic approach, S/S, Lg/S plus Lg/Lg genotypes were associated with higher energy intake daily at 1 year old and with waist circumference at 3 to 4 years old. In the biallelic approach, the 5-HTTLPR polymorphism is associated with food intake, body mass index Z-score and sum of skinfolds in children, reinforcing the role of the serotonin transporter in childhood obesity. Our data indicate that the biallelic approach is more sensible than the triallelic approach for detected associations with food intake and nutritional status in childhood. Identifying susceptibility genes in early life could provide the foundations for interventions in lifestyle to prevent children to become obese adults. Copyright © 2017. Published by Elsevier Inc.

  18. Dietary intake of children over two decades in a community and an approach for modification

    USDA-ARS?s Scientific Manuscript database

    Dietary intake is a major environmental factor influencing health and disease. Dietary studies of intake and eating patterns are a cornerstone of cardiovascular (CV) research. Such studies have been conducted in the Bogalusa Heart Study from its origin and have helped understand childhood nutrition ...

  19. A robust optimisation approach accounting for the effect of fractionation on setup uncertainties.

    PubMed

    Lowe, Matthew; Aitkenhead, Adam; Albertini, Francesca; Lomax, Antony J; MacKay, Ranald I

    2017-10-04

    Proton plans are subject to a number of uncertainties which must be accounted for to ensure that they are delivered safely. Misalignment resulting from residual errors in daily patient positioning can result in both a displacement and distortion of dose distributions. This can be particularly important for intensity modulated proton therapy treatments where the accurate alignment of highly modulated fields may be required to deliver the intended treatment. A number of methods to generate plans that are robust to these uncertainties exist. These include robust optimisation approaches which account for the effect of uncertainties on the dose distribution within the optimisation process. However, robustness to uncertainty comes at the cost of plan quality. For this reason, it is important that the uncertainties considered are realistic. Existing approaches to robust optimisation have neglected the role of fractionated treatment deliveries in reducing the uncertainties that result from random setup errors. Here, a method of robust optimisation which accounts for this effect is presented and is evaluated using a 2D planning environment. The optimisation algorithm considers the dose in the estimated upper and lower bounds of the dose distribution under the effect of setup and range errors. A comparison with plans robustly optimised without consideration of the effect of fractionation and conventionally optimised plans is presented. Fractionation incorporated robust optimisation demonstrates a reduced sensitivity to uncertainty compared to conventionally optimised plans and a reduced integral dose compared to robustly optimised plans.

  20. Comparison of Flamelet Models with the Transported Mass Fraction Approach for Supersonic Combustion

    NASA Astrophysics Data System (ADS)

    Li, Wenhai; Alabi, Ken; Ladeinde, Foluso

    2015-11-01

    In this study, two fully compressible RANS, LES, and combined RANS/LES flow solvers - AEROFLO and VULCAN, both of which were originally developed by the United States Department of Defense but have since been significantly enhanced and commercialized by our organization, are used to investigate the accuracy of flamelet-based approach when employed to model supersonic combustion. The flamelet results from both codes are assessed relative to solutions obtained by solving the transport equations for the mass fractions - which is also supported by one of the codes, and making familiar assumptions about the closure of the reaction rate. The studies are carried out in the flamelet regime, and the numerical procedures are based on high-order schemes, which are also used to solve the level-set and mixture fraction transport equations used to study, respectively, premixed and non-premixed combustion. The effects of supersonic Mach numbers on the results are discussed.

  1. A Fractional PDE Approach to Turbulent Mixing; Part II: Numerical Simulation

    NASA Astrophysics Data System (ADS)

    Samiee, Mehdi; Zayernouri, Mohsen

    2016-11-01

    We propose a generalizing fractional order transport model of advection-diffusion kind with fractional time- and space-derivatives, governing the evolution of passive scalar turbulence. This approach allows one to incorporate the nonlocal and memory effects in the underlying anomalous diffusion i.e., sub-to-standard diffusion to model the trapping of particles inside the eddied, and super-diffusion associated with the sudden jumps of particles from one coherent region to another. For this nonlocal model, we develop a high order numerical (spectral) method in addition to a fast solver, examined in the context of some canonical problems. PhD student, Department of Mechanical Engineering, & Department Computational Mathematics, Science, and Engineering.

  2. A risk-benefit analysis approach to seafood intake to determine optimal consumption.

    PubMed

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

    2012-06-01

    Seafood provides n-3 long-chain PUFA (n-3 LC-PUFA), vitamins and minerals, which are essential to maintain good health. Moreover, seafood is a source of contaminants such as methylmercury, arsenic and persistent organic pollutants that may affect health. The aim of the present study was to determine in what quantities seafood consumption would provide nutritional benefits, while minimising the risks linked to food contaminants. Seafood was grouped into clusters using a hierarchical cluster analysis. Those nutrients and contaminants were selected for which it is known that seafood is a major source. The risk-benefit analysis consisted in using an optimisation model with constraints to calculate optimum seafood cluster consumption levels. The goal was to optimise nutrient intakes as well as to limit contaminant exposure with the condition being to attain recommended nutritional intakes without exceeding tolerable upper intakes for contaminants and nutrients, while taking into account background intakes. An optimum consumption level was calculated for adults that minimises inorganic arsenic exposure and increases vitamin D intake in the general population. This consumption level guarantees that the consumer reaches the recommended intake for n-3 LC-PUFA, Se and I, while remaining below the tolerable upper intakes for methylmercury, Cd, dioxins, polychlorobiphenyls, Zn, Ca and Cu. This consumption level, which is approximately 200 g/week of certain fatty fish species and approximately 50 g/week of lean fish, molluscs and crustaceans, has to be considered in order to determine food consumption recommendations in a public health perspective.

  3. Towards a simple and sensitive size-density fractionation approach for determining changes in soil organic matter

    NASA Astrophysics Data System (ADS)

    Guidi, Claudia; Magid, Jakob; Rodeghiero, Mirco

    2017-04-01

    Fractionation of soil organic matter (SOM), i.e. the separation of SOM into discrete fractions, can elucidate the temporal responses of soil organic carbon (SOC) to land-use and management changes. In order to reduce the workload and uncertainties associated with fractionation, we optimized and tested a simple size-density fractionation approach, containing a limited number of fractions and using relatively mild soil dispersion. We compared size-density fractionation, which isolated non-occluded particulate organic matter (POM), stable aggregates and silt- and clay-sized fraction, with aggregate size fractionation, i.e. an established method for aggregate separation, and with SOC content in the bulk soil. These methods were tested on soil samples collected from the mineral soil (0-20 cm) of a land-use and management gradient examining forest colonization on grassland in the Southern Alps (Italy). Differences in SOC stocks among successional stages were detected both by size-density fractions, aggregate size fractions and SOC content in the bulk soil. However, size-density fractions were better suited than aggregate size fractions for the detection of changes in SOC allocation within the study area. Therefore, the tested size-density fractionation approach may be preferred over aggregate size fractionation, considering its higher sensitivity to SOC differences in the land-use gradient. Stable aggregates obtained by size-density fractionation detected both changes in SOC allocation and stocks, and have the potential to be used as indicators of SOC changes in soils that express aggregate hierarchy. Further testing of the developed procedure across soil types, environmental conditions and land uses is required to confirm its repeatability and sensitivity to SOC changes.

  4. Approach to ecological assessment of power-plant-intake (316b) related issues: the Prairie Island case

    SciTech Connect

    Adams, S.M.; Vaughan, D.S.; Hildebrand, S.G.; Kumar, K.D.

    1981-04-01

    Assessment approaches and strategies useful in addressing important issues in section 316(b) of the 1972 Federal Water Pollution Control Act are illustrated in this report through the analysis and evaluation of the Prairie Island Nuclear Station 316(b) data base. The main issues in 316(b) demonstrations, cooling water intake operation and location, involve determining the impacts of entrainment and impingement. Entrainment impacts were addressed by applying the equivalent adult approach and correcting for inherent biases and by determining the through-plant survival of zooplankton. An assessment of impingement impacts was made by comparing for each of various species the number of fish impinged to estimates of population size. Densities of plankton and fish were compared between the intake area and an alternate area to determine if the location of the present intake minimizes impacts. No definitive conclusion relative to the best location of the intake could be made because of high year to year variability in the data and the differential dominance of trophic groups between areas.

  5. Discovery of human urinary biomarkers of aronia-citrus juice intake by HPLC-q-TOF-based metabolomic approach.

    PubMed

    Llorach, Rafael; Medina, Sonia; García-Viguera, Cristina; Zafrilla, Pilar; Abellán, José; Jauregui, Olga; Tomás-Barberán, Francisco A; Gil-Izquierdo, Angel; Andrés-Lacueva, Cristina

    2014-06-01

    Metabolomics has emerged in the field of food and nutrition sciences as a powerful tool for doing profiling approaches. In this context, HPLC-q-TOF-based metabolomics approach was applied to unveil changes in the urinary metabolome in human subjects (n = 51, 23 men and 28 women) after regular aronia-citrus juice (AC-juice) intake (250 mL/day) during 16 weeks compared to individuals given a placebo beverage. Samples were analyzed by HPLC-q-TOF followed by multivariate data analysis (orthogonal signal filtering-partial least square discriminant analysis) that discriminated relevant mass features related to AC-juice intake. The results showed that biomarkers of AC-juice intake including metabolites coming from metabolism of food components as proline betaine, ferulic acid, and two unknown mercapturate derivatives were identified. Discovery of new biomarkers of food intake will help in the building up of the food metabolome and facilitate future insights into the mechanisms of action of dietary components in population health. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Ensemble Fractional Sensitivity: A Quantitative Approach to Neuron Selection for Decoding Motor Tasks

    PubMed Central

    Singhal, Girish; Aggarwal, Vikram; Acharya, Soumyadipta; Aguayo, Jose; He, Jiping; Thakor, Nitish

    2010-01-01

    A robust method to help identify the population of neurons used for decoding motor tasks is developed. We use sensitivity analysis to develop a new metric for quantifying the relative contribution of a neuron towards the decoded output, called “fractional sensitivity.” Previous model-based approaches for neuron ranking have been shown to largely depend on the collection of training data. We suggest the use of an ensemble of models that are trained on random subsets of trials to rank neurons. For this work, we tested a decoding algorithm on neuronal data recorded from two male rhesus monkeys while they performed a reach to grasp a bar at three orientations (45°, 90°, or 135°). An ensemble approach led to a statistically significant increase of 5% in decoding accuracy and 25% increase in identification accuracy of simulated noisy neurons, when compared to a single model. Furthermore, ranking neurons based on the ensemble fractional sensitivities resulted in decoding accuracies 10%–20% greater than when randomly selecting neurons or ranking based on firing rates alone. By systematically reducing the size of the input space, we determine the optimal number of neurons needed for decoding the motor output. This selection approach has practical benefits for other BMI applications where limited number of electrodes and training datasets are available, but high decoding accuracies are desirable. PMID:20169103

  7. Modeling the relationship between body weight and energy intake: A molecular diffusion-based approach

    PubMed Central

    2012-01-01

    Background Body weight is at least partly controlled by the choices made by a human in response to external stimuli. Changes in body weight are mainly caused by energy intake. By analyzing the mechanisms involved in food intake, we considered that molecular diffusion plays an important role in body weight changes. We propose a model based on Fick's second law of diffusion to simulate the relationship between energy intake and body weight. Results This model was applied to food intake and body weight data recorded in humans; the model showed a good fit to the experimental data. This model was also effective in predicting future body weight. Conclusions In conclusion, this model based on molecular diffusion provides a new insight into the body weight mechanisms. Reviewers This article was reviewed by Dr. Cabral Balreira (nominated by Dr. Peter Olofsson), Prof. Yang Kuang and Dr. Chao Chen. PMID:22742862

  8. An iterative method for tri-level quadratic fractional programming problems using fuzzy goal programming approach

    NASA Astrophysics Data System (ADS)

    Kassa, Semu Mitiku; Tsegay, Teklay Hailay

    2017-08-01

    Tri-level optimization problems are optimization problems with three nested hierarchical structures, where in most cases conflicting objectives are set at each level of hierarchy. Such problems are common in management, engineering designs and in decision making situations in general, and are known to be strongly NP-hard. Existing solution methods lack universality in solving these types of problems. In this paper, we investigate a tri-level programming problem with quadratic fractional objective functions at each of the three levels. A solution algorithm has been proposed by applying fuzzy goal programming approach and by reformulating the fractional constraints to equivalent but non-fractional non-linear constraints. Based on the transformed formulation, an iterative procedure is developed that can yield a satisfactory solution to the tri-level problem. The numerical results on various illustrative examples demonstrated that the proposed algorithm is very much promising and it can also be used to solve larger-sized as well as n-level problems of similar structure.

  9. SLFP: A stochastic linear fractional programming approach for sustainable waste management

    SciTech Connect

    Zhu, H.; Huang, G.H.

    2011-12-15

    Highlights: > A new fractional programming (SLFP) method is developed for waste management. > SLFP can solve ratio optimization problems associated with random inputs. > A case study of waste flow allocation demonstrates its applicability. > SLFP helps compare objectives of two aspects and reflect system efficiency. > This study supports in-depth analysis of tradeoffs among multiple system criteria. - Abstract: A stochastic linear fractional programming (SLFP) approach is developed for supporting sustainable municipal solid waste management under uncertainty. The SLFP method can solve ratio optimization problems associated with random information, where chance-constrained programming is integrated into a linear fractional programming framework. It has advantages in: (1) comparing objectives of two aspects, (2) reflecting system efficiency, (3) dealing with uncertainty expressed as probability distributions, and (4) providing optimal-ratio solutions under different system-reliability conditions. The method is applied to a case study of waste flow allocation within a municipal solid waste (MSW) management system. The obtained solutions are useful for identifying sustainable MSW management schemes with maximized system efficiency under various constraint-violation risks. The results indicate that SLFP can support in-depth analysis of the interrelationships among system efficiency, system cost and system-failure risk.

  10. Fractionation profiling: a fast and versatile approach for mapping vesicle proteomes and protein–protein interactions

    PubMed Central

    Borner, Georg H. H.; Hein, Marco Y.; Hirst, Jennifer; Edgar, James R.; Mann, Matthias; Robinson, Margaret S.

    2014-01-01

    We developed “fractionation profiling,” a method for rapid proteomic analysis of membrane vesicles and protein particles. The approach combines quantitative proteomics with subcellular fractionation to generate signature protein abundance distribution profiles. Functionally associated groups of proteins are revealed through cluster analysis. To validate the method, we first profiled >3500 proteins from HeLa cells and identified known clathrin-coated vesicle proteins with >90% accuracy. We then profiled >2400 proteins from Drosophila S2 cells, and we report the first comprehensive insect clathrin-coated vesicle proteome. Of importance, the cluster analysis extends to all profiled proteins and thus identifies a diverse range of known and novel cytosolic and membrane-associated protein complexes. We show that it also allows the detailed compositional characterization of complexes, including the delineation of subcomplexes and subunit stoichiometry. Our predictions are presented in an interactive database. Fractionation profiling is a universal method for defining the clathrin-coated vesicle proteome and may be adapted for the analysis of other types of vesicles and particles. In addition, it provides a versatile tool for the rapid generation of large-scale protein interaction maps. PMID:25165137

  11. Introducing the Improved Heaviside Approach to Partial Fraction Decomposition to Undergraduate Students: Results and Implications from a Pilot Study

    ERIC Educational Resources Information Center

    Man, Yiu-Kwong

    2012-01-01

    Partial fraction decomposition is a useful technique often taught at senior secondary or undergraduate levels to handle integrations, inverse Laplace transforms or linear ordinary differential equations, etc. In recent years, an improved Heaviside's approach to partial fraction decomposition was introduced and developed by the author. An important…

  12. Introducing the Improved Heaviside Approach to Partial Fraction Decomposition to Undergraduate Students: Results and Implications from a Pilot Study

    ERIC Educational Resources Information Center

    Man, Yiu-Kwong

    2012-01-01

    Partial fraction decomposition is a useful technique often taught at senior secondary or undergraduate levels to handle integrations, inverse Laplace transforms or linear ordinary differential equations, etc. In recent years, an improved Heaviside's approach to partial fraction decomposition was introduced and developed by the author. An important…

  13. Ab initio quantum mechanical/molecular mechanical simulation of electron transfer process: fractional electron approach.

    PubMed

    Zeng, Xiancheng; Hu, Hao; Hu, Xiangqian; Cohen, Aron J; Yang, Weitao

    2008-03-28

    Electron transfer (ET) reactions are one of the most important processes in chemistry and biology. Because of the quantum nature of the processes and the complicated roles of the solvent, theoretical study of ET processes is challenging. To simulate ET processes at the electronic level, we have developed an efficient density functional theory (DFT) quantum mechanical (QM)/molecular mechanical (MM) approach that uses the fractional number of electrons as the order parameter to calculate the redox free energy of ET reactions in solution. We applied this method to study the ET reactions of the aqueous metal complexes Fe(H(2)O)(6)(2+/3+) and Ru(H(2)O)(6)(2+/3+). The calculated oxidation potentials, 5.82 eV for Fe(II/III) and 5.14 eV for Ru(II/III), agree well with the experimental data, 5.50 and 4.96 eV, for iron and ruthenium, respectively. Furthermore, we have constructed the diabatic free energy surfaces from histogram analysis based on the molecular dynamics trajectories. The resulting reorganization energy and the diabatic activation energy also show good agreement with experimental data. Our calculations show that using the fractional number of electrons (FNE) as the order parameter in the thermodynamic integration process leads to efficient sampling and validate the ab initio QM/MM approach in the calculation of redox free energies.

  14. A genetic approach for investigating vagal sensory roles in regulation of gastrointestinal function and food intake.

    PubMed

    Fox, Edward Alan

    2006-06-30

    Sensory innervation of the gastrointestinal (GI) tract by the vagus nerve plays important roles in regulation of GI function and feeding behavior. This innervation is composed of a large number of sensory pathways, each arising from a different population of sensory receptors. Progress in understanding the functions of these pathways has been impeded by their close association with vagal efferent, sympathetic, and enteric systems, which makes it difficult to selectively label or manipulate them. We suggest that a genetic approach may overcome these barriers. To illustrate the potential value of this strategy, as well as to gain insights into its application, investigations of CNS pathways and peripheral tissues involved in energy balance that benefited from the use of gene manipulations are reviewed. Next, our studies examining the feasibility of using mutations of developmental genes for manipulating individual vagal afferent pathways are reviewed. These experiments characterized mechanoreceptor morphology, density and distribution, and feeding patterns in four viable mutant mouse strains. In each strain a single population of vagal mechanoreceptors innervating the muscle wall of the GI tract was altered, and was associated with selective effects on feeding patterns, thus supporting the feasibility of this strategy. However, two limitations of this approach must be addressed for it to achieve its full potential. First, mutation effects in tissues outside the GI tract can contribute to changes in GI function or feeding. Additionally, knockouts of developmental genes are often lethal, preventing analysis of mature innervation and ingestive behavior. To address these issues, we propose to develop conditional gene knockouts restricted to specific GI tract tissues. Two genes of interest are brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), which are essential for vagal afferent development. Creating conditional knockouts of these genes requires

  15. Systems genetics and genome-wide association approaches for analysis of feed intake, feed efficiency, and performance in beef cattle.

    PubMed

    Santana, M H A; Freua, M C; Do, D N; Ventura, R V; Kadarmideen, H N; Ferraz, J B S

    2016-10-17

    Feed intake, feed efficiency, and weight gain are important economic traits of beef cattle in feedlots. In the present study, we investigated the physiological processes underlying such traits from the point of view of systems genetics. Firstly, using data from 1334 Nellore (Bos indicus) cattle and 943,577 single nucleotide polymorphisms (SNPs), a genome-wide association analysis was performed for dry matter intake, average daily weight gain, feed conversion ratio, and residual feed intake with a Bayesian Lasso procedure. Genes within 50-kb SNPs, most relevant for explaining the genomic variance, were annotated and the biological processes underlying the traits were inferred from Database for Annotation, Visualization and Integrated Discovery (DAVID) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Our results indicated several putative genomic regions associated with the target phenotypes and showed that almost all genomic variances were in the SNPs located in the intergenic and intronic regions. We further identified five main metabolic pathways related to ion transport, body composition, and feed intake control, which influenced the four phenotypes simultaneously. The systems genetics approach used in this study revealed novel pathways related to feed efficiency traits in beef cattle.

  16. Dominant pole placement with fractional order PID controllers: D-decomposition approach.

    PubMed

    Mandić, Petar D; Šekara, Tomislav B; Lazarević, Mihailo P; Bošković, Marko

    2017-03-01

    Dominant pole placement is a useful technique designed to deal with the problem of controlling a high order or time-delay systems with low order controller such as the PID controller. This paper tries to solve this problem by using D-decomposition method. Straightforward analytic procedure makes this method extremely powerful and easy to apply. This technique is applicable to a wide range of transfer functions: with or without time-delay, rational and non-rational ones, and those describing distributed parameter systems. In order to control as many different processes as possible, a fractional order PID controller is introduced, as a generalization of classical PID controller. As a consequence, it provides additional parameters for better adjusting system performances. The design method presented in this paper tunes the parameters of PID and fractional PID controller in order to obtain good load disturbance response with a constraint on the maximum sensitivity and sensitivity to noise measurement. Good set point response is also one of the design goals of this technique. Numerous examples taken from the process industry are given, and D-decomposition approach is compared with other PID optimization methods to show its effectiveness.

  17. A fractionation approach applying chelating magnetic nanoparticles to characterize pericardial fluid's proteome.

    PubMed

    Trindade, Fábio; Bastos, Paulo; Leite-Moreira, Adelino; Manadas, Bruno; Ferreira, Rita; Soares, Sofia F; Daniel-da-Silva, Ana L; Falcão-Pires, Inês; Vitorino, Rui

    2017-09-23

    Owing to their close proximity, pericardial fluid (PF)'s proteome may mirror the pathophysiological status of the heart. Despite this diagnosis potential, the knowledge of PF's proteome is scarce. Large amounts of albumin hamper the characterization of the least abundant proteins in PF. Aiming to expand PF's proteome and to validate the technique for future applications, we have fractionated and characterized the PF, using N-(trimethoxysilylpropyl)ethylenediamine triacetic acid (EDTA)-functionalized magnetic nanoparticles (NPs@EDTA) followed by a GeLC-MS/MS approach. Similarly to an albumin-depletion kit, NPs@EDTA-based fractionation was efficient in removing albumin. Both methods displayed comparable inter-individual variability, but NPs@EDTA outperformed the former with regard to the protein dynamic range as well as to the monitoring of biological processes. Overall, 565 proteins were identified, of which 297 (>50%) have never been assigned to PF. Moreover, owing to this method's good proteome reproducibility, affordability, rapid automation and high binding ability of NP@EDTA, it bears a great potential towards future clinical application. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Mechanisms of ammonium assimilation by Chlorella vulgaris F1068: Isotope fractionation and proteomic approaches.

    PubMed

    Liu, Na; Li, Feng; Ge, Fei; Tao, Nengguo; Zhou, Qiongzhi; Wong, Minghung

    2015-08-01

    Removal of ammonium (NH4(+)-N) by microalgae has evoked interest in wastewater treatment, however, the detailed mechanisms of ammonium assimilation remain mysterious. This study investigated the effects of NH4(+)-N concentration on the removal and biotransformation efficiency by Chlorella vulgaris F1068, and explored the mechanisms by (15)N isotope fractionation and proteome approaches. The results showed NH4(+)-N was efficiently removed (84.8%) by F1068 at 10mgL(-1) of NH4(+)-N. The isotope enrichment factor (ε=-2.37±0.08‰) of (15)N isotope fractionation revealed 47.6% biotransformation at above condition, while 7.0% biotransformation at 4mgL(-1) of NH4(+)-N (ε=-1.63±0.06‰). This was due to the different expression of glutamine synthetase, a key enzyme in ammonium assimilation, which was up-regulated 6.4-fold at proteome level and 18.0-fold at transcription level. The results will provide a better mechanistic understanding of ammonium assimilation by microalgae and this green technology is expected to reduce the burden of NH4(+)-N removal for municipal sewage treatment plants.

  19. CONCEPTUAL BASIS FOR MULTI-ROUTE INTAKE DOSE MODELING USING AN ENERGY EXPENDITURE APPROACH

    EPA Science Inventory

    This paper provides the conceptual basis for a modeling logic that is currently being developed in the National Exposure Research Laboratory (NERL) of the U.S. Environmental Protection Agency ( EPA) for use in intake dose assessments involving substances that can enter the body...

  20. CONCEPTUAL BASIS FOR MULTI-ROUTE INTAKE DOSE MODELING USING AN ENERGY EXPENDITURE APPROACH

    EPA Science Inventory

    This paper provides the conceptual basis for a modeling logic that is currently being developed in the National Exposure Research Laboratory (NERL) of the U.S. Environmental Protection Agency ( EPA) for use in intake dose assessments involving substances that can enter the body...

  1. H∞ synchronization of uncertain fractional order chaotic systems: adaptive fuzzy approach.

    PubMed

    Lin, Tsung-Chih; Kuo, Chia-Hao

    2011-10-01

    This paper presents a novel adaptive fuzzy logic controller (FLC) equipped with an adaptive algorithm to achieve H(∞) synchronization performance for uncertain fractional order chaotic systems. In order to handle the high level of uncertainties and noisy training data, a desired synchronization error can be attenuated to a prescribed level by incorporating fuzzy control design and H(∞) tracking approach. Based on a Lyapunov stability criterion, not only the performance of the proposed method is satisfying with an acceptable synchronization error level, but also a rather simple stability analysis is performed. The simulation results signify the effectiveness of the proposed control scheme. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  2. Hyperspherical Slater determinant approach to few-body fractional quantum Hall states

    NASA Astrophysics Data System (ADS)

    Yan, Bin; Wooten, Rachel E.; Daily, Kevin M.; Greene, Chris H.

    2017-05-01

    In a recent study (Daily et al., 2015), a hyperspherical approach has been developed to study few-body fractional quantum Hall states. This method has been successfully applied to the exploration of few boson and fermion problems in the quantum Hall region, as well as the study of inter-Landau level collective excitations (Rittenhouse et al., 2016; Wooten et al., 2016). However, the hyperspherical method as it is normally implemented requires a subsidiary (anti-)symmetrization process, which limits its computational effectiveness. The present work overcomes these difficulties and extends the power of this method by implementing a representation of the hyperspherical many-body basis space in terms of Slater determinants of single particle eigenfunctions. A clear connection between the hyperspherical representation and the conventional single particle picture is presented, along with a compact operator representation of the theoretical framework.

  3. Electrophysiologic testing guided risk stratification approach for sudden cardiac death beyond the left ventricular ejection fraction.

    PubMed

    Gatzoulis, Konstantinos A; Tsiachris, Dimitris; Arsenos, Petros; Tousoulis, Dimitris

    2016-01-26

    Sudden cardiac death threats ischaemic and dilated cardiomyopathy patients. Anti- arrhythmic protection may be provided to these patients with implanted cardiac defibrillators (ICD), after an efficient risk stratification approach. The proposed risk stratifier of an impaired left ventricular ejection fraction has limited sensitivity meaning that a significant number of victims will remain undetectable by this risk stratification approach because they have a preserved left ventricular systolic function. Current risk stratification strategies focus on combinations of non invasive methods like T wave alternans, late potentials, heart rate turbulence, deceleration capacity and others, with invasive methods like the electrophysiologic study. In the presence of an electrically impaired substrate with formed post myocardial infarction fibrotic zones, programmed ventricular stimulation provides important prognostic information for the selection of the patients expected to benefit from an ICD implantation, while due to its high negative predictive value, patients at low risk level may also be detected. Clustering evidence from different research groups and electrophysiologic labs support an electrophysiologic testing guided risk stratification approach for sudden cardiac death.

  4. A new analytical approach to solve some of the fractional-order partial differential equations

    NASA Astrophysics Data System (ADS)

    Manafian, Jalil; Lakestani, Mehrdad

    2017-03-01

    The aim of the present paper is to present an analytical method for the time fractional biological population model, time fractional Burgers, time fractional Cahn-Hilliard, space-time fractional Whitham-Broer-Kaup, space-time fractional Fokas equations by using the generalized tanh-coth method. The fractional derivative is described in the sense of the modified Riemann-Liouville derivatives. The method gives an analytic solution in the form of a convergent series with easily computable components, requiring no linearization or small perturbation. We have obtained the exact solutions for the aforementioned nonlinear fractional equations. A generalized fractional complex transform is appropriately used to convert these fractional equations to ordinary differential equations which subsequently resulted into number of exact solutions.

  5. Measurement Approach to Teaching Fractions: A Design Experiment in a Pre-Service Course for Elementary Teachers

    ERIC Educational Resources Information Center

    Bobos, Georgeana; Sierpinska, Anna

    2017-01-01

    In this paper, we present a design experiment in a "Teaching Mathematics" course for prospective elementary teachers where we sought to develop a "measurement approach" to fractions. We focus on the conceptualization of the mathematical content of the approach. We attribute our progress in the conceptualization to our efforts…

  6. Matrix approach to discrete fractional calculus III: non-equidistant grids, variable step length and distributed orders.

    PubMed

    Podlubny, Igor; Skovranek, Tomas; Vinagre Jara, Blas M; Petras, Ivo; Verbitsky, Viktor; Chen, YangQuan

    2013-05-13

    In this paper, we further develop Podlubny's matrix approach to discretization of integrals and derivatives of non-integer order. Numerical integration and differentiation on non-equidistant grids is introduced and illustrated by several examples of numerical solution of differential equations with fractional derivatives of constant orders and with distributed-order derivatives. In this paper, for the first time, we present a variable-step-length approach that we call 'the method of large steps', because it is applied in combination with the matrix approach for each 'large step'. This new method is also illustrated by an easy-to-follow example. The presented approach allows fractional-order and distributed-order differentiation and integration of non-uniformly sampled signals, and opens the way to development of variable- and adaptive-step-length techniques for fractional- and distributed-order differential equations.

  7. Influence of environmental factors on food intake among nursing home residents: a survey combined with a video approach.

    PubMed

    Buckinx, Fanny; Reginster, Jean-Yves; Morelle, Alison; Paquot, Nicolas; Labeye, Nicole; Locquet, Médéa; Adam, Stéphane; Bruyère, Olivier

    2017-01-01

    In addition to the well-known physiological factors, dietary behavior that affects health seems to be influenced by a wide variety of environmental factors. The aim of this study was to assess, by means of an original video approach, the influence of the environment on food intake in nursing homes. The perception of the environment during meals in nursing homes was evaluated by residents and by two groups of volunteers who either work in the field of geriatrics, or who do not work in the field of geriatrics. First, a random sample of residents answered a self-administered questionnaire related to different indicators (ie, noise, space, comfort, light, odors, perceived satisfaction of meals, taste of meals, presentation of meals, service and setting). Second, two separate panels, one including the people who work in the field of geriatrics (ie, experts) and one including the people who have no particular interest in geriatrics (ie, nonexperts), were asked to answer a questionnaire on their perception of the environment after having watched a video of the lunch in each nursing home. Then, the food intake of the residents was measured by a precise food-weighing method. A total of 88 residents from nine different nursing homes, 18 experts and 45 nonexperts answered the questionnaires. This study highlighted that, on the one hand, after adjustment on confounding variables, the perception of the quantity of food served by the residents is the only single factor associated with food consumption (P=0.003). On the other hand, experts and nonexperts did not perceive any environmental factor that seems to be significantly associated with residents' food intake. Our results highlighted that, in a nursing home setting, environmental factors have limited influence on the food intake of the residents, with the exception of their own perception of the quantity served. The relevance of this factor deserves further investigation.

  8. Unified fractional differential approach for transient interporosity flow in naturally fractured media

    NASA Astrophysics Data System (ADS)

    Babak, Petro; Azaiez, Jalel

    2014-12-01

    A unified approach to modeling flows of slightly compressible fluids through naturally fractured media is presented. The unified fractional differential model is derived by combining the flow at micro scale for matrix blocks and macro scale for fractures, using the transient interporosity flow behavior at the interface between matrix blocks and fractures. The derived model is able to unify existing transient interporosity flow models formulated for different shapes of matrix blocks in any medium dimensions. The model is formulated in the form of a fractional order partial differential equation that involves Caputo derivative of order 1/2 with respect to time. Explicit solutions for the unified model are derived for different axisymmetrical spatial domains using Hankel or Hankel-Weber finite or infinite transforms. Comparisons between the predictions of the unified model and those obtained from existing transient interporosity flow models for matrix blocks in the form of slabs, spheres and cylinders are presented. It is shown that the unified fractional derivative model leads to solutions that are very close to those of transient interporosity flow models for fracture-dominant and transitional fracture-to-matrix dominant flow regimes. An analysis of the results of the unified model reveals that the pressure varies linearly with the logarithm of time for different flow regimes, with half slope for the transitional fracture-to-matrix dominant flow regime vs. the fracture and matrix dominant flow regimes. In addition, a new re-scaling that involves the characteristic length in the form of matrix block volume to surface area ratio is derived for the transient interporosity flow models for matrix blocks of different shapes. It is shown that the re-scaled transient interporosity flow models are governed by two dimensionless parameters Θ and Λ compared to only one dimensionless parameter Θ for the unified model. It is shown that the solutions of the transient

  9. Fractional and fractal dynamics approach to anomalous diffusion in porous media: application to landslide behavior

    NASA Astrophysics Data System (ADS)

    Martelloni, Gianluca; Bagnoli, Franco

    2016-04-01

    intense or long rain that percolates into the soil causing an increasing of the pore water pressure. In literature two type of models exist for attempting to forecast the landslides triggering: statistical or empirical modeling based on rainfall thresholds derived from the analysis of temporal series of daily rain [34] and geotechnical modeling, i.e., slope stability models that take into account water infiltration by rainfall considering classical Richardson equations [35-39]. Regarding the propagation of landslides, the models follow Eulerian (e.g., finite element methods, [40]) or Lagrangian approach (e.g., particle or molecular dynamics methods [41-46]). In a preliminary work [44], the possibility of the integration between fractional-based infiltration modeling and molecular dynamics approach, to model both the triggering and propagation, has been investigated in order to characterize the granular material varying the order of fractional derivative taking into account the equation -∂δ ∂2θ(z,t) ∂tδθ(z,t)=D ∂z2 , (6) where θ(z,t) represents the water content depending on time t and soil depth z [47], while the parameter δ, with 0.5 ≤ δ < 1, represents the fractional derivative order to consider anomalous sub-diffusion [48]; when δ = 1 we have classical derivative, i.e., normal diffusion, and when δ > 1 super-diffusion [32]. To sum up, in [44], a three-dimensional model is developed, the water content is expressed in term of pore pressure (interpreted as a scalar field acting on the particles), whose increasing induces the shear strength reduction. The latter is taking into account by means of Mohr-Coulomb criterion that represents a failure criterion based on limit equilibrium theory [49, 50]. Moreover, the fluctuations depending on positions, in term of pore pressure, are also considered. Concerning the interaction between particles, a Lennard-Jones potential is taking into account and other active forces as gravity, dynamic friction and viscosity

  10. Quantification of sand fraction from seismic attributes using Neuro-Fuzzy approach

    NASA Astrophysics Data System (ADS)

    Verma, Akhilesh K.; Chaki, Soumi; Routray, Aurobinda; Mohanty, William K.; Jenamani, Mamata

    2014-12-01

    In this paper, we illustrate the modeling of a reservoir property (sand fraction) from seismic attributes namely seismic impedance, seismic amplitude, and instantaneous frequency using Neuro-Fuzzy (NF) approach. Input dataset includes 3D post-stacked seismic attributes and six well logs acquired from a hydrocarbon field located in the western coast of India. Presence of thin sand and shale layers in the basin area makes the modeling of reservoir characteristic a challenging task. Though seismic data is helpful in extrapolation of reservoir properties away from boreholes; yet, it could be challenging to delineate thin sand and shale reservoirs using seismic data due to its limited resolvability. Therefore, it is important to develop state-of-art intelligent methods for calibrating a nonlinear mapping between seismic data and target reservoir variables. Neural networks have shown its potential to model such nonlinear mappings; however, uncertainties associated with the model and datasets are still a concern. Hence, introduction of Fuzzy Logic (FL) is beneficial for handling these uncertainties. More specifically, hybrid variants of Artificial Neural Network (ANN) and fuzzy logic, i.e., NF methods, are capable for the modeling reservoir characteristics by integrating the explicit knowledge representation power of FL with the learning ability of neural networks. In this paper, we opt for ANN and three different categories of Adaptive Neuro-Fuzzy Inference System (ANFIS) based on clustering of the available datasets. A comparative analysis of these three different NF models (i.e., Sugeno-type fuzzy inference systems using a grid partition on the data (Model 1), using subtractive clustering (Model 2), and using Fuzzy c-means (FCM) clustering (Model 3)) and ANN suggests that Model 3 has outperformed its counterparts in terms of performance evaluators on the present dataset. Performance of the selected algorithms is evaluated in terms of correlation coefficients (CC), root

  11. Enriching student concept images: Teaching and learning fractions through a multiple-embodiment approach

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaofen; Clements, M. A. (Ken); Ellerton, Nerida F.

    2015-06-01

    This study investigated how fifth-grade children's concept images of the unit fractions represented by the symbols , , and changed as a result of their participation in an instructional intervention based on multiple embodiments of fraction concepts. The participants' concept images were examined through pre- and post-teaching written questions and pre- and post-teaching one-to-one verbal interview questions. Results showed that at the pre-teaching stage, the student concept images of unit fractions were very narrow and mainly linked to area models. However, after the instructional intervention, the fifth graders were able to select and apply a variety of models in response to unit fraction tasks, and their concept images of unit fractions were enriched and linked to capacity, perimeter, linear and discrete models, as well as to area models. Their performances on tests had improved, and their conceptual understandings of unit fractions had developed.

  12. Effects of the Dietary Approaches to Stop Hypertension (DASH) Diet and Sodium Intake on Serum Uric Acid.

    PubMed

    Juraschek, Stephen P; Gelber, Allan C; Choi, Hyon K; Appel, Lawrence J; Miller, Edgar R

    2016-12-01

    Randomized trial data guiding dietary recommendations to lower serum uric acid (UA), the etiologic precursor of gout, are scarce. We undertook this study to examine the effects of the Dietary Approaches to Stop Hypertension (DASH) diet (a well-established diet that lowers blood pressure) and levels of sodium intake on serum UA. We conducted an ancillary study of a randomized, crossover feeding trial in 103 adults with prehypertension or stage I hypertension. Participants were randomly assigned to receive either the DASH diet or a control diet (typical of the average American diet) and were further fed low, medium, and high levels of sodium for 30 days, each in random order. Body weight was kept constant. Serum UA levels were measured at baseline and following each feeding period. Trial participants were 55% women and 75% black with a mean ± SD age of 51.5 ± 9.7 years and a mean ± SD serum UA level of 5.0 ± 1.3 mg/dl. The DASH diet reduced serum UA (-0.35 mg/dl [95% confidence interval (95% CI) -0.65, -0.05], P = 0.02), with a higher effect (-1.29 mg/dl [95% CI -2.50, -0.08]) among participants (n = 8) with a baseline serum UA level of ≥7 mg/dl. Increasing sodium intake from the low level decreased serum UA during the medium sodium intake period (-0.3 mg/dl [95% CI -0.5, -0.2], P < 0.001) and during the high sodium intake period (-0.4 mg/dl [95% CI -0.6, -0.3], P < 0.001). The DASH diet lowered serum UA, and this effect was greater among participants with hyperuricemia. Moreover, we found that higher sodium intake decreased serum UA, which enhances our knowledge of urate pathophysiology and risk factors for hyperuricemia. © 2016, American College of Rheumatology.

  13. Memory Function Approach to Chaos and Turbulence and the Continued Fraction Expansion

    NASA Astrophysics Data System (ADS)

    Mori, H.; Kuroki, S.; Tominaga, H.; Ishizaki, R.

    2004-05-01

    The chaotic orbits of dynamical systems are deterministic and predictable on short timescales τr, but they become stochastic and random on long timescales τM(≫ τr) due to the orbital instability of chaos. This randomization of chaotic orbits has been formulated recently by deriving a non-Markovian stochastic equation for macrovariables in terms of a fluctuating force and a memory function. In order to develop this memory function approach to chaos and turbulence, we explore the following problems by studying the Duffing oscillator and the Navier-Stokes equation for an incompressible fluid: 1) the physical meaning of the projection of macrovariables A(t) onto A(0); 2) the method of calculating the short-lived motion with short timescale τr, which determines the memory functions and the macroscopic transport coefficients due to chaos and turbulence; 3) the continued fraction expansion of the memory function, and the order estimation of short timescales τr and long timescales τM; 4) the relation between the memory function and the time correlation function of a nonlinear force, which gives computable theoretical expressions for the macroscopic transport coefficients.

  14. Long-memory and the sea level-temperature relationship: a fractional cointegration approach.

    PubMed

    Ventosa-Santaulària, Daniel; Heres, David R; Martínez-Hernández, L Catalina

    2014-01-01

    Through thermal expansion of oceans and melting of land-based ice, global warming is very likely contributing to the sea level rise observed during the 20th century. The amount by which further increases in global average temperature could affect sea level is only known with large uncertainties due to the limited capacity of physics-based models to predict sea levels from global surface temperatures. Semi-empirical approaches have been implemented to estimate the statistical relationship between these two variables providing an alternative measure on which to base potentially disrupting impacts on coastal communities and ecosystems. However, only a few of these semi-empirical applications had addressed the spurious inference that is likely to be drawn when one nonstationary process is regressed on another. Furthermore, it has been shown that spurious effects are not eliminated by stationary processes when these possess strong long memory. Our results indicate that both global temperature and sea level indeed present the characteristics of long memory processes. Nevertheless, we find that these variables are fractionally cointegrated when sea-ice extent is incorporated as an instrumental variable for temperature which in our estimations has a statistically significant positive impact on global sea level.

  15. Long-Memory and the Sea Level-Temperature Relationship: A Fractional Cointegration Approach

    PubMed Central

    Ventosa-Santaulària, Daniel; Heres, David R.; Martínez-Hernández, L. Catalina

    2014-01-01

    Through thermal expansion of oceans and melting of land-based ice, global warming is very likely contributing to the sea level rise observed during the 20th century. The amount by which further increases in global average temperature could affect sea level is only known with large uncertainties due to the limited capacity of physics-based models to predict sea levels from global surface temperatures. Semi-empirical approaches have been implemented to estimate the statistical relationship between these two variables providing an alternative measure on which to base potentially disrupting impacts on coastal communities and ecosystems. However, only a few of these semi-empirical applications had addressed the spurious inference that is likely to be drawn when one nonstationary process is regressed on another. Furthermore, it has been shown that spurious effects are not eliminated by stationary processes when these possess strong long memory. Our results indicate that both global temperature and sea level indeed present the characteristics of long memory processes. Nevertheless, we find that these variables are fractionally cointegrated when sea-ice extent is incorporated as an instrumental variable for temperature which in our estimations has a statistically significant positive impact on global sea level. PMID:25426638

  16. Using the Small Ruminant Nutrition System to develop and evaluate an alternative approach to estimating the dry matter intake of goats when accounting for ruminal fiber stratification.

    PubMed

    Regadas Filho, J G L; Tedeschi, L O; Cannas, A; Vieira, R A M; Rodrigues, M T

    2014-11-01

    The first objective of this research was to assess the ability of the Small Ruminant Nutrition System (SRNS) mechanistic model to predict metabolizable energy intake (MEI) and milk yield (MY) when using a heterogeneous fiber pool scenario (GnG1), compared with a traditional, homogeneous scenario (G1). The second objective was to evaluate an alternative approach to estimating the dry matter intake (DMI) of goats to be used in the SRNS model. The GnG1 scenario considers an age-dependent fractional transference rate for fiber particles from the first ruminal fiber pool (raft) to an escapable pool (λr), and that this second ruminal fiber pool (i.e., escapable pool) follows an age-independent fractional escape rate for fiber particles (ke). Scenario G1 adopted only a single fractional passage rate (kp). All parameters were estimated individually by using equations published in the literature, except for 2 passage rate equations in the G1 scenario: 1 developed with sheep data (G1-S) and another developed with goat data (G1-G). The alternative approach to estimating DMI was based on an optimization process using a series of dietary constraints. The DMI, MEI, and MY estimated for the GnG1 and G1 scenarios were compared with the results of an independent dataset (n=327) that contained information regarding DMI, MEI, MY, and milk and dietary compositions. The evaluation of the scenarios was performed using the coefficient of determination (R(2)) between the observed and predicted values, mean bias (MB), bias correction factor (Cb), and concordance correlation coefficient. The MEI estimated by the GnG1 scenario yielded precise and accurate values (R(2) = 082; MB = 0.21 Mcal/d; Cb = 0.98) similar to those of the G1-S (R(2) = 0.85; MB = 0.10 Mcal/d; Cb=0.99) and G1-G (R(2) = 0.84; MB = 0.18 Mcal/d; Cb = 0.98) scenarios. The results were also similar for the MY, but a substantial MB was found as follows: GnG1 (R(2) = 0.74; MB = 0.70 kg/d; Cb = 0.79), G1-S (R(2) = 0.71; MB = 0

  17. Identifying critical nutrient intake in groups at risk of poverty in Europe: the CHANCE project approach.

    PubMed

    Nikolić, Marina; Glibetić, Maria; Gurinović, Mirjana; Milešević, Jelena; Khokhar, Santosh; Chillo, Stefania; Abaravicius, Jonas Algis; Bordoni, Alessandra; Capozzi, Francesco

    2014-04-02

    The aim of the CHANCE project is to develop novel and affordable nutritious foods to optimize the diet and reduce the risk of diet-related diseases among groups at risk of poverty (ROP). This paper describes the methodology used in the two initial steps to accomplish the project's objective as follows: 1. a literature review of existing data and 2. an identification of ROP groups with which to design and perform the CHANCE nutritional survey, which will supply new data that is useful for formulating the new CHANCE food. Based on the literature review, a low intake of fruit and vegetables, whole grain products, fish, energy, fiber, vitamins B1, B2, B3, B6, B12 and C, folate, calcium, magnesium, iron, potassium and zinc and a high intake of starchy foods, processed meat and sodium were apparent. However, the available data appeared fragmented because of the different methodologies used in the studies. A more global vision of the main nutritional problems that are present among low-income people in Europe is needed, and the first step to achieve this goal is the use of common criteria to define the risk of poverty. The scoring system described here represents novel criteria for defining at-risk-of-poverty groups not only in the CHANCE-participating countries but also all over Europe.

  18. Identifying Critical Nutrient Intake in Groups at Risk of Poverty in Europe: The CHANCE Project Approach

    PubMed Central

    Nikolić, Marina; Glibetić, Maria; Gurinović, Mirjana; Milešević, Jelena; Khokhar, Santosh; Chillo, Stefania; Abaravicius, Jonas Algis; Bordoni, Alessandra; Capozzi, Francesco

    2014-01-01

    The aim of the CHANCE project is to develop novel and affordable nutritious foods to optimize the diet and reduce the risk of diet-related diseases among groups at risk of poverty (ROP). This paper describes the methodology used in the two initial steps to accomplish the project’s objective as follows: 1. a literature review of existing data and 2. an identification of ROP groups with which to design and perform the CHANCE nutritional survey, which will supply new data that is useful for formulating the new CHANCE food. Based on the literature review, a low intake of fruit and vegetables, whole grain products, fish, energy, fiber, vitamins B1, B2, B3, B6, B12 and C, folate, calcium, magnesium, iron, potassium and zinc and a high intake of starchy foods, processed meat and sodium were apparent. However, the available data appeared fragmented because of the different methodologies used in the studies. A more global vision of the main nutritional problems that are present among low-income people in Europe is needed, and the first step to achieve this goal is the use of common criteria to define the risk of poverty. The scoring system described here represents novel criteria for defining at-risk-of-poverty groups not only in the CHANCE-participating countries but also all over Europe. PMID:24699195

  19. A more fundamental approach to the derivation of nonlinear acoustic wave equations with fractional loss operators (L).

    PubMed

    Prieur, Fabrice; Vilenskiy, Gregory; Holm, Sverre

    2012-10-01

    A corrected derivation of nonlinear wave propagation equations with fractional loss operators is presented. The fundamental approach is based on fractional formulations of the stress-strain and heat flux definitions but uses the energy equation and thermodynamic identities to link density and pressure instead of an erroneous fractional form of the entropy equation as done in Prieur and Holm ["Nonlinear acoustic wave equations with fractional loss operators," J. Acoust. Soc. Am. 130(3), 1125-1132 (2011)]. The loss operator of the obtained nonlinear wave equations differs from the previous derivations as well as the dispersion equation, but when approximating for low frequencies the expressions for the frequency dependent attenuation and velocity dispersion remain unchanged.

  20. Relationship between cloud radiative forcing, cloud fraction and cloud albedo, and new surface-based approach for determining cloud albedo

    SciTech Connect

    Liu, Y.; Wu, W.; Jensen, M. P.; Toto, T.

    2011-07-21

    This paper focuses on three interconnected topics: (1) quantitative relationship between surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo; (2) surface-based approach for measuring cloud albedo; (3) multiscale (diurnal, annual and inter-annual) variations and covariations of surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo. An analytical expression is first derived to quantify the relationship between cloud radiative forcing, cloud fraction, and cloud albedo. The analytical expression is then used to deduce a new approach for inferring cloud albedo from concurrent surface-based measurements of downwelling surface shortwave radiation and cloud fraction. High-resolution decade-long data on cloud albedos are obtained by use of this surface-based approach over the US Department of Energy's Atmospheric Radiaton Measurement (ARM) Program at the Great Southern Plains (SGP) site. The surface-based cloud albedos are further compared against those derived from the coincident GOES satellite measurements. The three long-term (1997-2009) sets of hourly data on shortwave cloud radiative forcing, cloud fraction and cloud albedo collected over the SGP site are analyzed to explore the multiscale (diurnal, annual and inter-annual) variations and covariations. The analytical formulation is useful for diagnosing deficiencies of cloud-radiation parameterizations in climate models.

  1. A comparison between the multimedia fate and exposure models CalTOX and uniform system for evaluation of substances adapted for life-cycle assessment based on the population intake fraction of toxic pollutants.

    PubMed

    Huijbregts, Mark A J; Geelen, Loes M J; Hertwich, Edgar G; McKone, Thomas E; van de Meent, Dik

    2005-02-01

    In life-cycle assessment (LCA) and comparative risk assessment, potential human exposure to toxic pollutants can be expressed as the population intake fraction (iF), which represents the fraction of the quantity emitted that enters the human population. To assess the influence of model differences in the calculation of the population iF ingestion and inhalation iFs of 365 substances emitted to air, freshwater, and soil were calculated with two commonly applied multimedia fate and exposure models, CalTOX and the uniform system for evaluation of substances adapted for life-cycle assessment (USES-LCA). The model comparison showed that differences in the iFs due to model choices were the lowest after emission to air and the highest after emission to soil. Inhalation iFs were more sensitive to model differences compared to ingestion iFs. The choice for a continental seawater compartment, vertical stratification of the soil compartment, rain and no-rain scenarios, and drinking water purification mainly clarify the relevant model differences found in population iFs. Furthermore, pH correction of chemical properties and aerosol-associated deposition on plants appeared to be important for dissociative organics and metals emitted to air, respectively. Finally, it was found that quantitative structure-activity relationship estimates for superhydrophobics may introduce considerable uncertainty in the calculation of population intake fractions.

  2. Incorporation of Root and Surface Litter Inputs Into Soil C Pools: What Do Different Physical Fractionation Approaches Tell Us?

    NASA Astrophysics Data System (ADS)

    Jastrow, J. D.; Swanston, C. W.; O'Brien, S. L.; Moran, K. K.; Porras, R. C.; Torn, M. S.

    2008-12-01

    Efforts to isolate soil C pools related to the structure, function and turnover of soil organic matter (SOM) often employ physical fractionation methods. Both density-based and particle-size fractionations have been used to examine the role of aggregates in SOM cycling and stabilization. After a 14C pulse labeling of deciduous forest, reciprocal transplants of enriched vs. near-background litter allowed us to track the source and dynamics of SOM pools isolated by both fractionation approaches. Light fraction (LF) and particulate organic matter (POM) were separated into unprotected and aggregate-protected pools by applying different dispersion energies. The mineral-associated pool was characterized either as the dense fraction (DF) or as particles <53 μm (MOM). We used procedural constraints and the distributions of bulk soil C and 14C to compare pools isolated by each method. The uPOM fraction included both free and macroaggregate-associated particulate C pools, whereas the free LF isolated mostly unprotected, interstitial particulate C. Operationally, the mPOM fraction consisted of microaggregate-protected particulate C, but the occluded LF included both macroaggregate-associated and microaggregate-protected C. Overall, POM accounted for 5% more of bulk soil C than LF, with the difference likely due to inclusion of some microaggregate-protected particulate C in the DF. POM/LF-C dynamics associated with root turnover occurred mostly at the macroaggregate rather than the microaggregate scale during the 4-y study. In contrast, the dynamics of litter C sources occurred at both scales suggesting a different mode of incorporation, e.g., sorption of soluble C to exchange sites or assimilation by microbes associated with the POM/LF. Acid hydrolysis of the MOM fraction revealed dynamic components that rapidly incorporated and cycled C inputs from both root and litter sources. Taken together, the results improve our understanding of short-term soil C dynamics and the C

  3. A new approach for the fractionation of water-soluble organic carbon in atmospheric aerosols and cloud drops

    NASA Astrophysics Data System (ADS)

    Andracchio, Antonella; Cavicchi, Catia; Tonelli, Domenica; Zappoli, Sergio

    A novel approach is described for the fractionation of water-soluble organic carbon (WSOC) in atmospheric aerosols and cloud drops. The method is based on the preliminary adsorption of the sample, acidified at pH 2, on a polymeric styrene-divinylbenzene resin (XAD-2) and subsequent elution with a series of solvents, which leads to the fractionation of the sample into three classes of compounds. The method was set up using synthetic mixtures of organic compounds and then applied to selected samples of atmospheric aerosols and cloud drops. All samples and collected fractions were analysed using size exclusion chromatography (SEC). This method proved particularly useful both in providing information on the organic content of the samples and for the characterisation of the macromolecular compounds (MMCs) in the samples. Synthetic samples were prepared using humic, fulvic and tannic acid to simulate naturally occurring MMCs. In the first fraction, eluted with HCl, only the most soluble organic compounds (oxalic acid, formic acid and acetic acid) were collected. In the second fraction, eluted with methanol, the major part of the organic material was collected together with the more hydrophilic constituents of the humic substances. In the third fraction, it was possible to separately recover the more hydrophobic component of the humic substances. A large number of atmospheric samples (fog, aerosol, cloud) were then analysed using SEC. Most of these samples evidenced a noteworthy chromatogram at 254 nm. Moreover, the chromatographic area evidenced a clear linear correlation with the total organic carbon (TOC) values. The fractionation method on XAD-2 was finally applied to selected atmospheric samples, yielding three classes of organic compounds. In each sample, a non-negligible amount of compounds with dimensional and chemical properties similar to humic substances were collected in the third fraction. The carbon content in this latter fraction was estimated both by TOC

  4. The fractional coupled KdV equations: Exact solutions and white noise functional approach

    NASA Astrophysics Data System (ADS)

    Hossam, A. Ghany; S. Okb El Bab, A.; M. Zabel, A.; Abd-Allah, Hyder

    2013-08-01

    Variable coefficients and Wick-type stochastic fractional coupled KdV equations are investigated. By using the modified fractional sub-equation method, Hermite transform, and white noise theory the exact travelling wave solutions and white noise functional solutions are obtained, including the generalized exponential, hyperbolic, and trigonometric types.

  5. An Investigation of Fraction Models in Early Elementary Grades: A Mixed-Methods Approach

    ERIC Educational Resources Information Center

    Wilkerson, Trena L.; Cooper, Susan; Gupta, Dittika; Montgomery, Mark; Mechell, Sara; Arterbury, Kristin; Moore, Sherrie; Baker, Betty Ruth; Sharp, Pat T.

    2015-01-01

    This study examines the effect varying models have on student understanding of fractions. The study addressed the question of what students know and understand about fractional concepts through the use of discrete and continuous models. A sample of 54 students in kindergarten and 3rd grade were given an interview pretest, participated in…

  6. Enriching Student Concept Images: Teaching and Learning Fractions through a Multiple-Embodiment Approach

    ERIC Educational Resources Information Center

    Zhang, Xiaofen; Clements, M. A.; Ellerton, Nerida F.

    2015-01-01

    This study investigated how fifth-grade children's concept images of the unit fractions represented by the symbols 1/2, 1/3/ and 1/4 changed as a result of their participation in an instructional intervention based on multiple embodiments of fraction concepts. The participants' concept images were examined through pre- and post-teaching written…

  7. Enriching Student Concept Images: Teaching and Learning Fractions through a Multiple-Embodiment Approach

    ERIC Educational Resources Information Center

    Zhang, Xiaofen; Clements, M. A.; Ellerton, Nerida F.

    2015-01-01

    This study investigated how fifth-grade children's concept images of the unit fractions represented by the symbols 1/2, 1/3/ and 1/4 changed as a result of their participation in an instructional intervention based on multiple embodiments of fraction concepts. The participants' concept images were examined through pre- and post-teaching written…

  8. Addressing the risk of inadequate and excessive micronutrient intakes: traditional versus new approaches to setting adequate and safe micronutrient levels in foods

    PubMed Central

    Bruins, Maaike J.; Mugambi, Gladys; Verkaik-Kloosterman, Janneke; Hoekstra, Jeljer; Kraemer, Klaus; Osendarp, Saskia; Melse-Boonstra, Alida; Gallagher, Alison M.; Verhagen, Hans

    2015-01-01

    Fortification of foods consumed by the general population or specific food products or supplements designed to be consumed by vulnerable target groups is amongst the strategies in developing countries to address micronutrient deficiencies. Any strategy aimed at dietary change needs careful consideration, ensuring the needs of at-risk subgroups are met whilst ensuring safety within the general population. This paper reviews the key principles of two main assessment approaches that may assist developing countries in deciding on effective and safe micronutrient levels in foods or special products designed to address micronutrient deficiencies, that is, the cut-point method and the stepwise approach to risk–benefit assessment. In the first approach, the goal is to shift population intake distributions such that intake prevalences below the Estimated Average Requirement (EAR) and above the Tolerable Upper Intake Level (UL) are both minimized. However, for some micronutrients like vitamin A and zinc, a narrow margin between the EAR and UL exists. Increasing their intakes through mass fortification may pose a dilemma; not permitting the UL to be exceeded provides assurance about the safety within the population but can potentially leave a proportion of the target population with unmet needs, or vice versa. Risk–benefit approaches assist in decision making at different micronutrient intake scenarios by balancing the magnitude of potential health benefits of reducing inadequate intakes against health risks of excessive intakes. Risk–benefit approaches consider different aspects of health risk including severity and number of people affected. This approach reduces the uncertainty for policy makers as compared to classic cut-point methods. PMID:25630617

  9. Fractional randomness

    NASA Astrophysics Data System (ADS)

    Tapiero, Charles S.; Vallois, Pierre

    2016-11-01

    The premise of this paper is that a fractional probability distribution is based on fractional operators and the fractional (Hurst) index used that alters the classical setting of random variables. For example, a random variable defined by its density function might not have a fractional density function defined in its conventional sense. Practically, it implies that a distribution's granularity defined by a fractional kernel may have properties that differ due to the fractional index used and the fractional calculus applied to define it. The purpose of this paper is to consider an application of fractional calculus to define the fractional density function of a random variable. In addition, we provide and prove a number of results, defining the functional forms of these distributions as well as their existence. In particular, we define fractional probability distributions for increasing and decreasing functions that are right continuous. Examples are used to motivate the usefulness of a statistical approach to fractional calculus and its application to economic and financial problems. In conclusion, this paper is a preliminary attempt to construct statistical fractional models. Due to the breadth and the extent of such problems, this paper may be considered as an initial attempt to do so.

  10. The effect of school district nutrition policies on dietary intake and overweight: a synthetic control approach.

    PubMed

    Bauhoff, Sebastian

    2014-01-01

    School nutrition policies aim to eliminate ubiquitous unhealthy foods and beverages from schools to improve adolescent dietary behavior and reduce childhood obesity. This paper evaluates the impact of an early nutrition policy, Los Angeles Unified School District's food-and-beverage standards of 2004, using two large datasets on food intake and physical measures. I implement cohort and cross-section estimators using "synthetic" control groups, combinations of unaffected districts that are reweighted to closely resemble the treatment unit in the pre-intervention period. The results indicate that the policy was mostly ineffective at reducing the prevalence of overweight or obesity 8-15 months after the intervention but significantly decreased consumption of two key targets, soda and fried foods. The policy's impact on physical outcomes appears to be mitigated by substitution toward foods that are still (or newly) available in the schools.

  11. An approach for assessing potential sediment-bound contaminant threats near the intake of a drinking water treatment plant.

    PubMed

    Chen, Fei; Anderson, William B; Huck, Peter M

    2013-01-01

    To assist in assessing a potential contaminated sediment threat near a drinking water intake in a large lake, a technique known as the fingerprint analysis of leachate contaminants (FALCON), was investigated and enhanced to help draw more statistically significant definitive conclusions. This represents the first application of this approach, originally developed by the USEPA to characterize and track leachate penetration in groundwater and contaminant migration from waste and landfill sites, in a large lake from the point-of-view of source water protection. FALCON provided valuable information regarding contaminated sediment characterization, source attribution, and transport within a surface water context without the need for knowledge of local hydrodynamic conditions, potentially reducing reliance on complicated hydrodynamic analysis. A t-test to evaluate the significance of correlations was shown to further enhance the FALCON procedure. In this study, the sensitivity of FALCON was found to be improved by using concentration data from both conserved organics and heavy metals in combination. Furthermore, data analysis indicated that it may be possible to indirectly assess the success of remediation efforts (and the corresponding need to plan for a treatment upgrade in the event of escalating contaminant concentrations) by examining the temporal change in correlation between the source and intake sediment fingerprints over time. This method has potential for widespread application in situations where conserved contaminants such as heavy metals and higher molecular weight polycyclic aromatic hydrocarbons (PAHs), are being or have previously been deposited in sediment somewhere in, or within range of, an intake protection zone. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. A computationally efficient approach for isolating satellite phase fractional cycle biases based on Kalman filter

    NASA Astrophysics Data System (ADS)

    Xiao, Guorui; Mayer, Michael; Heck, Bernhard; Sui, Lifen; Cong, Mingri

    2017-04-01

    Integer ambiguity resolution (AR) can significantly shorten the convergence time and improve the accuracy of Precise Point Positioning (PPP). Phase fractional cycle biases (FCB) originating from satellites destroy the integer nature of carrier phase ambiguities. To isolate the satellite FCB, observations from a global reference network are required. Firstly, float ambiguities containing FCBs are obtained by PPP processing. Secondly, the least squares method (LSM) is adopted to recover FCBs from all the float ambiguities. Finally, the estimated FCB products can be applied by the user to achieve PPP-AR. During the estimation of FCB, the LSM step can be very time-consuming, considering the large number of observations from hundreds of stations and thousands of epochs. In addition, iterations are required to deal with the one-cycle inconsistency among observations. Since the integer ambiguities are derived by directly rounding float ambiguities, the one-cycle inconsistency arises whenever the fractional parts of float ambiguities exceed the rounding boundary (e.g., 0.5 and -0.5). The iterations of LSM and the large number of observations require a long time to finish the estimation. Consequently, only a sparse global network containing a limited number of stations was processed in former research. In this paper, we propose to isolate the FCB based on a Kalman filter. The large number of observations is handled epoch-by-epoch, which significantly reduces the dimension of the involved matrix and accelerates the computation. In addition, it is also suitable for real-time applications. As for the one-cycle inconsistency, a pre-elimination method is developed to avoid the iteration of the whole process. According to the analysis of the derived satellite FCB products, we find that both wide-lane (WL) and narrow-lane (NL) FCB are very stable over time (e.g., WL FCB over several days rsp. NL FCB over tens of minutes). The stability implies that the satellite FCB can be removed

  13. Fractional-order elastic models of cartilage: A multi-scale approach

    NASA Astrophysics Data System (ADS)

    Magin, Richard L.; Royston, Thomas J.

    2010-03-01

    The objective of this research is to develop new quantitative methods to describe the elastic properties (e.g., shear modulus, viscosity) of biological tissues such as cartilage. Cartilage is a connective tissue that provides the lining for most of the joints in the body. Tissue histology of cartilage reveals a multi-scale architecture that spans a wide range from individual collagen and proteoglycan molecules to families of twisted macromolecular fibers and fibrils, and finally to a network of cells and extracellular matrix that form layers in the connective tissue. The principal cells in cartilage are chondrocytes that function at the microscopic scale by creating nano-scale networks of proteins whose biomechanical properties are ultimately expressed at the macroscopic scale in the tissue's viscoelasticity. The challenge for the bioengineer is to develop multi-scale modeling tools that predict the three-dimensional macro-scale mechanical performance of cartilage from micro-scale models. Magnetic resonance imaging (MRI) and MR elastography (MRE) provide a basis for developing such models based on the nondestructive biomechanical assessment of cartilage in vitro and in vivo. This approach, for example, uses MRI to visualize developing proto-cartilage structure, MRE to characterize the shear modulus of such structures, and fractional calculus to describe the dynamic behavior. Such models can be extended using hysteresis modeling to account for the non-linear nature of the tissue. These techniques extend the existing computational methods to predict stiffness and strength, to assess short versus long term load response, and to measure static versus dynamic response to mechanical loads over a wide range of frequencies (50-1500 Hz). In the future, such methods can perhaps be used to help identify early changes in regenerative connective tissue at the microscopic scale and to enable more effective diagnostic monitoring of the onset of disease.

  14. A machine-learning approach for computation of fractional flow reserve from coronary computed tomography.

    PubMed

    Itu, Lucian; Rapaka, Saikiran; Passerini, Tiziano; Georgescu, Bogdan; Schwemmer, Chris; Schoebinger, Max; Flohr, Thomas; Sharma, Puneet; Comaniciu, Dorin

    2016-07-01

    Fractional flow reserve (FFR) is a functional index quantifying the severity of coronary artery lesions and is clinically obtained using an invasive, catheter-based measurement. Recently, physics-based models have shown great promise in being able to noninvasively estimate FFR from patient-specific anatomical information, e.g., obtained from computed tomography scans of the heart and the coronary arteries. However, these models have high computational demand, limiting their clinical adoption. In this paper, we present a machine-learning-based model for predicting FFR as an alternative to physics-based approaches. The model is trained on a large database of synthetically generated coronary anatomies, where the target values are computed using the physics-based model. The trained model predicts FFR at each point along the centerline of the coronary tree, and its performance was assessed by comparing the predictions against physics-based computations and against invasively measured FFR for 87 patients and 125 lesions in total. Correlation between machine-learning and physics-based predictions was excellent (0.9994, P < 0.001), and no systematic bias was found in Bland-Altman analysis: mean difference was -0.00081 ± 0.0039. Invasive FFR ≤ 0.80 was found in 38 lesions out of 125 and was predicted by the machine-learning algorithm with a sensitivity of 81.6%, a specificity of 83.9%, and an accuracy of 83.2%. The correlation was 0.729 (P < 0.001). Compared with the physics-based computation, average execution time was reduced by more than 80 times, leading to near real-time assessment of FFR. Average execution time went down from 196.3 ± 78.5 s for the CFD model to ∼2.4 ± 0.44 s for the machine-learning model on a workstation with 3.4-GHz Intel i7 8-core processor.

  15. HCl and DCl: a case study of different approaches for determining photo fractionation constants.

    PubMed

    Grage, Mette M-L; Nyman, Gunnar; Johnson, Matthew S

    2006-11-07

    The photoabsorption cross sections of HCl and DCl are calculated using the reflection principle and time dependent wavepacket propagation methods. The absorption cross sections are compared to high precision experimental absorption cross sections from the literature and the different results given by the methods are discussed. The results of the calculations emphasize the important roles that photodissociation dynamics and the change in transition dipole moment with internuclear distance play in isotopic fractionation. The wave number dependent fractionation constants have been determined. The process fractionation constant has been calculated in the Venusian atmosphere where photo-fractionation leads to enrichment in deuterium through loss of hydrogen to space. At an altitude of 70 km the process fractionation constant was found to be epsilon(p) = -344 per thousand and epsilon(p) = -256 per thousand for the experimental and the reflection principle methods, respectively. At the top of the atmosphere the process fractionation constant was evaluated to be epsilon(p) = -32 per thousand, epsilon(p) = -20 per thousand and epsilon(p) = -40 per thousand using the experimental data, the wavepacket and the reflection principle methods, respectively. Using the Rayleigh distillation formula it is concluded that HCl at the top of the Venusian atmosphere is fractionated (enriched in D) relative to the bulk composition prior to photolysis.

  16. An approach to design controllers for MIMO fractional-order plants based on parameter optimization algorithm.

    PubMed

    Xue, Dingyü; Li, Tingxue

    2017-04-27

    The parameter optimization method for multivariable systems is extended to the controller design problems for multiple input multiple output (MIMO) square fractional-order plants. The algorithm can be applied to search for the optimal parameters of integer-order controllers for fractional-order plants with or without time delays. Two examples are given to present the controller design procedures for MIMO fractional-order systems. Simulation studies show that the integer-order controllers designed are robust to plant gain variations. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Analytical approach to linear fractional partial differential equations arising in fluid mechanics

    NASA Astrophysics Data System (ADS)

    Momani, Shaher; Odibat, Zaid

    2006-07-01

    In this Letter, we implement relatively new analytical techniques, the variational iteration method and the Adomian decomposition method, for solving linear fractional partial differential equations arising in fluid mechanics. The fractional derivatives are described in the Caputo sense. The two methods in applied mathematics can be used as alternative methods for obtaining analytic and approximate solutions for different types of fractional differential equations. In these methods, the solution takes the form of a convergent series with easily computable components. The corresponding solutions of the integer order equations are found to follow as special cases of those of fractional order equations. Some numerical examples are presented to illustrate the efficiency and reliability of the two methods.

  18. Prescribed performance synchronization controller design of fractional-order chaotic systems: An adaptive neural network control approach

    NASA Astrophysics Data System (ADS)

    Li, Yuan; Lv, Hui; Jiao, Dongxiu

    2017-03-01

    In this study, an adaptive neural network synchronization (NNS) approach, capable of guaranteeing prescribed performance (PP), is designed for non-identical fractional-order chaotic systems (FOCSs). For PP synchronization, we mean that the synchronization error converges to an arbitrary small region of the origin with convergence rate greater than some function given in advance. Neural networks are utilized to estimate unknown nonlinear functions in the closed-loop system. Based on the integer-order Lyapunov stability theorem, a fractional-order adaptive NNS controller is designed, and the PP can be guaranteed. Finally, simulation results are presented to confirm our results.

  19. Comparison of different approaches to calculate nutrient intakes based upon 24-h recall data derived from a multicenter study in European adolescents.

    PubMed

    Julián-Almárcegui, Cristina; Bel-Serrat, Silvia; Kersting, Mathilde; Vicente-Rodriguez, German; Nicolas, Genevieve; Vyncke, Krishna; Vereecken, Carine; De Keyzer, Willem; Beghin, Laurent; Sette, Stefania; Halström, Lena; Grammatikaki, Eva; Gonzalez-Gross, Marcela; Crispim, Sandra; Slimani, Nadia; Moreno, Luis; De Henauw, Stefaan; Huybrechts, Inge

    2016-03-01

    The European "Healthy Lifestyle in Europe by Nutrition in Adolescence" (HELENA) project evaluated two different approaches to harmonize the matching procedures between 24-h recall data and food composition databases. In the first approach, the 24-h recall data were linked to the local/national food composition databases using standardized procedures, while in the second approach, the 24-h recall data were linked to the German BLS database which includes a larger food list. The aim of this paper was to compare the intakes of energy and eight nutrient components calculated via both approaches. Two non-consecutive 24-h recalls were performed in 1268 adolescents. Energy, carbohydrates, proteins, fat, fiber, water, alcohol, calcium and vitamin C were calculated via the two approaches at individual level. Paired samples t test and Pearson's correlations were used to compare the mean intakes of energy and the eight mentioned nutrients and to investigate the possible associations between the two approaches. Small but significant differences were found between the intakes of energy and the eight food components when comparing both approaches. Very strong and strong correlations (0.70-0.95) were found between both methods for all nutrients. The dietary intakes obtained via the two different linking procedures are highly correlated for energy and the eight nutrients under study.

  20. Effect of ME-3451-106, an aqueous extract of Stichaster striatus with inhibitory activity of voluntary alcohol intake, in genetically drinker rats: Isolation and identification of the active fraction.

    PubMed

    Font, M; Bilbeny, N; Contreras, S; Paeile, C; García, H

    2006-04-21

    The aqueous extract obtained from Stichaster striatus Müller & Troschel (Asteroidea, Stichasteridae) has been shown to possess activity as an alcohol appetite inhibitor after oral administration in a rat model with a genetically established excessive appetite for alcohol (Wistar rats, lineage UChB). A significant decrease in the consumption of ethanol was observed (unrelated to a possible disulfiram effect) without a change in the normal food or water intake during the experimentation period. A bio-guided fractionation of the extract was carried out in order to identify the most active fraction, in which the presence of a group of natural endogenous polyamines in undetermined proportions is suspected. Our hypothesis was to relate the activity obtained for the original ME-3451-106 extract with the presence of these polyamines in the extract in question. The activity shown by a series of commercially available polyamines (putrescine (Pu), spermidine (SPD) and spermine (SP)) in inhibiting voluntary ethanol intake lends support to our hypothesis. The extract was selected on the basis of oral tradition, which claimed that the consumption of a "soup" obtained by boiling starfish, later identified as Stichaster striatus, prevented the appearance of alcoholism in laborers on properties entrusted to the Jesuit order during the middle period of the Spanish conquest of America (17-18th century).

  1. Alcohol Intake and Blood Pressure: A Systematic Review Implementing a Mendelian Randomization Approach

    PubMed Central

    Chen, Lina; Davey Smith, George; Harbord, Roger M; Lewis, Sarah J

    2008-01-01

    Background Alcohol has been reported to be a common and modifiable risk factor for hypertension. However, observational studies are subject to confounding by other behavioural and sociodemographic factors, while clinical trials are difficult to implement and have limited follow-up time. Mendelian randomization can provide robust evidence on the nature of this association by use of a common polymorphism in aldehyde dehydrogenase 2 (ALDH2) as a surrogate for measuring alcohol consumption. ALDH2 encodes a major enzyme involved in alcohol metabolism. Individuals homozygous for the null variant (*2*2) experience adverse symptoms when drinking alcohol and consequently drink considerably less alcohol than wild-type homozygotes (*1*1) or heterozygotes. We hypothesise that this polymorphism may influence the risk of hypertension by affecting alcohol drinking behaviour. Methods and Findings We carried out fixed effect meta-analyses of the ALDH2 genotype with blood pressure (five studies, n = 7,658) and hypertension (three studies, n = 4,219) using studies identified via systematic review. In males, we obtained an overall odds ratio of 2.42 (95% confidence interval [CI] 1.66–3.55, p = 4.8 × 10−6) for hypertension comparing *1*1 with *2*2 homozygotes and an odds ratio of 1.72 (95% CI 1.17–2.52, p = 0.006) comparing heterozygotes (surrogate for moderate drinkers) with *2*2 homozygotes. Systolic blood pressure was 7.44 mmHg (95% CI 5.39–9.49, p = 1.1 × 10−12) greater among *1*1 than among *2*2 homozygotes, and 4.24 mmHg (95% CI 2.18–6.31, p = 0.00005) greater among heterozygotes than among *2*2 homozygotes. Conclusions These findings support the hypothesis that alcohol intake has a marked effect on blood pressure and the risk of hypertension. PMID:18318597

  2. Estimating the hatchery fraction of a natural population: a Bayesian approach

    USGS Publications Warehouse

    Barber, Jarrett J.; Gerow, Kenneth G.; Connolly, Patrick J.; Singh, Sarabdeep

    2011-01-01

    There is strong and growing interest in estimating the proportion of hatchery fish that are in a natural population (the hatchery fraction). In a sample of fish from the relevant population, some are observed to be marked, indicating their origin as hatchery fish. The observed proportion of marked fish is usually less than the actual hatchery fraction, since the observed proportion is determined by the proportion originally marked, differential survival (usually lower) of marked fish relative to unmarked hatchery fish, and rates of mark retention and detection. Bayesian methods can work well in a setting such as this, in which empirical data are limited but for which there may be considerable expert judgment regarding these values. We explored a Bayesian estimation of the hatchery fraction using Monte Carlo–Markov chain methods. Based on our findings, we created an interactive Excel tool to implement the algorithm, which we have made available for free.

  3. Tracking ultrasonically structural changes of natural aquatic organic carbon: Chemical fractionation and spectroscopic approaches.

    PubMed

    Al-Juboori, Raed A; Yusaf, Talal; Aravinthan, Vasantha; Bowtell, Leslie

    2016-02-01

    In this study, the structural alteration to DOC for a range of ultrasound treatments was investigated with chemical fractionation and UV-vis spectroscopic measurement. Ultrasound treatments were applied in continuous and pulsed modes at power levels of 48 and 84 W for effective treatment times of 5 and 15 min. Overall results show that the ultrasound treatments tended to degrade the hydrophobic aromatic fraction, while increasing the hydrophilic fraction to a lesser extent. The highest recorded reduction of hydrophobic DOC (17.8%) was achieved with pulse treatment of 84 W for15 min, while the highest increase in the hydrophilic DOC (10.5%) was obtained with continuous treatment at 84 W and 5 min. The optimal ultrasound treatment conditions were found to be pulse mode at high power and short treatment time, causing a minimal increase in the hydrophilic fraction of 1.3% with moderate removal of the hydrophobic fraction of 15.52%. The same treatment conditions, with longer treatment time, resulted in the highest removal of SUVA254 and SUVA280 of 17.09% and 16.93, respectively. These results indicate the potential for ultrasound treatments in DOC structural alteration. The hydrophobic fraction showed strong and significant correlations with UV absorbance at 254 and 280 nm. A254/A204 also exhibited strong and significant correlations with the hydrophobic/hydrophilic ratio. The other UV ratios (A250/A365 (E2/E3) and A254/A436) had weak and insignificant correlations with the hydrophobic/hydrophilic ratio. This confirms the applicability of UV indices as a suitable surrogate method for estimating the hydrophobic/hydrophilic structure.

  4. Analytical approaches for the approximate solution of a nonlinear fractional ordinary differential equation

    NASA Astrophysics Data System (ADS)

    Basak, K. C.; Ray, P. C.; Bera, R. K.

    2009-10-01

    The aim of the present analysis is to apply the Adomian decomposition method and He's variational method for the approximate analytical solution of a nonlinear ordinary fractional differential equation. The solutions obtained by the above two methods have been numerically evaluated and presented in the form of tables and also compared with the exact solution. It was found that the results obtained by the above two methods are in excellent agreement with the exact solution. Finally, a surface plot of the approximate solutions of the fractional differential equation by the above two methods is drawn for 0<=t<=2 and 1<α<=2.

  5. A Predictor-Corrector Approach for the Numerical Solution of Fractional Differential Equations

    NASA Technical Reports Server (NTRS)

    Diethelm, Kai; Ford, Neville J.; Freed, Alan D.; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    We discuss an Adams-type predictor-corrector method for the numerical solution of fractional differential equations. The method may be used both for linear and for nonlinear problems, and it may be extended to multi-term equations (involving more than one differential operator) too.

  6. Analytical lie group approach for solving fractional integro-differential equations

    NASA Astrophysics Data System (ADS)

    Pashayi, S.; Hashemi, M. S.; Shahmorad, S.

    2017-10-01

    This study is concerned with the Lie symmetry group analysis of Fractional Integro-Differential Equations (FIDEs) with nonlocal structures based on a new development of prolongation formula. A new prolongation for FIDEs is extracted and invariant solutions are finally presented for some illustrative examples.

  7. Fractional volume integration in two-dimensional NMR spectra: CAKE, a Monte Carlo approach.

    PubMed

    Romano, Rocco; Paris, Debora; Acernese, Fausto; Barone, Fabrizio; Motta, Andrea

    2008-06-01

    Quantitative information from multi-dimensional NMR experiments can be obtained by peak volume integration. The standard procedure (selection of a region around the chosen peak and addition of all values) is often biased by poor peak definition because of peak overlap. Here we describe a simple method, called CAKE, for volume integration of (partially) overlapping peaks. Assuming the axial symmetry of two-dimensional NMR peaks, as it occurs in NOESY and TOCSY when Lorentz-Gauss transformation of the signals is carried out, CAKE estimates the peak volume by multiplying a volume fraction by a factor R. It represents a proportionality ratio between the total and the fractional volume, which is identified as a slice in an exposed region of the overlapping peaks. The volume fraction is obtained via Monte Carlo Hit-or-Miss technique, which proved to be the most efficient because of the small region and the limited number of points within the selected area. Tests on simulated and experimental peaks, with different degrees of overlap and signal-to-noise ratios, show that CAKE results in improved volume estimates. A main advantage of CAKE is that the volume fraction can be flexibly chosen so as to minimize the effect of overlap, frequently observed in two-dimensional spectra.

  8. A pore scale modeling approach to isotopic fractionation during reactive transport through porous media

    NASA Astrophysics Data System (ADS)

    Huber, C.; Druhan, J. L.; Parmigiani, A.; Shafei, B.; Maher, K.

    2013-12-01

    The stable isotope compositions of reactant and product species are commonly utilized in the analysis of biogeochemical cycling, contaminant remediation and paleo-proxy records. While novel analytical models for isotopic exchange during steady state mineral growth are poised to offer new insights into these fields, commonly encountered transient conditions such as variable saturation state, flow rate and porosity/permeability present a formidable challenge. The problem arises from the precipitation of new mineral that is isotopically variant normal to the plane of growth, reflecting the temporal evolution of the adjacent, supersaturated fluid (e.g. Pearce et al., 2012; Druhan et al., 2013). Reactive transport models intended to describe isotopic exchange between the fluid and mineral surface then incur error through the use of a bulk mineral isotopic ratio rather than tracking a spatially variable isotopic composition within the solid. Here we present a novel multi-species, pore-scale reactive transport code based on the lattice Boltzmann method (LBM) capable of simulating the individual isotopes of calcium during fractionating, kinetically controlled precipitation of calcite from a supersaturated, flowing fluid. The isotopic composition of the mineral surface in contact with the advecting fluid is tracked through time by computing the averaged isotopic composition of the solid fraction over small solid volume fraction bins. This method allows us to model isotopic composition zoning at a scale smaller than that of the computational grid, thus effectively distinguishing the isotopic ratio of the mineral surface in contact with the fluid from the remainder of the solid phase. Druhan, J.L.; Steefel, C.I.; Williams, K.H.; DePaolo, D.J. (2013) Calcium isotope fractionation in groundwater: Molecular scale processes influencing field scale behavior. Geochim. Cosmochim. Acta., in press. Pearce, C.R.; Saldi, G.D.; Schott, J.; Oelkers, E.H. (2012) Isotopic fractionation

  9. Comparison of the regional CO2 mole fraction filtering approaches at a WMO/GAW regional station in China

    NASA Astrophysics Data System (ADS)

    Fang, S. X.; Tans, P. P.; Steinbacher, M.; Zhou, L. X.; Luan, T.

    2015-12-01

    The identification of atmospheric CO2 observation data which are minimally influenced by very local emissions/removals is essential for trend analysis, for the estimation of regional sources and sinks, and for the modeling of long-range transport of CO2. In this study, four approaches are used to filter the atmospheric CO2 observation records from 2009 to 2011 at one World Meteorological Organization/Global Atmosphere Watch (WMO/GAW) regional station (Lin'an, LAN) in China. The methods are based on the concentration of atmospheric black carbon (BC), on a statistical approach (robust extraction of baseline signal, REBS), on CH4 as an auxiliary tracer (AUX), and on meteorological parameters (MET). All approaches do suitably well to capture the seasonal CO2 cycle at LAN. Differences are observed in the average regional mole fractions with annual values in the REBS method at least 1.7 ± 0.2 ppm higher than the other methods. The BC method may underestimate the regional CO2 mole fractions during the winter-spring period and should be treated with caution. The REBS method is a purely statistical method and it may also introduce errors on the regional CO2 mole fraction evaluations, as the filtered trend may be influenced by the "noisy" raw data series. Although there are correlations between CH4 and CO2 mole fractions at LAN, the different source/sink regimes may introduce bias on the regional CO2 estimation in the AUX method, typically in summer. Overall, the MET method seems to be the most favorable because it mainly focuses on the influence of potential local sources and sinks, and considers diurnal variations and meteorological conditions. Using the MET method, the annual growth rate of regional CO2 at LAN is determined to be 3.1 ± 0.01 ppm yr-1 (standard error) from 2009 to 2011.

  10. Study of the regional CO2 mole fractions filtering approach at a WMO/GAW regional station in China

    NASA Astrophysics Data System (ADS)

    Fang, S. X.; Tans, P. P.; Steinbacher, M.; Zhou, L. X.; Luan, T.

    2015-07-01

    The identification of atmospheric CO2 observation data which is minimally influenced by very local emissions/removals is essential for the estimation of trend analysis, regional sources and sinks, and for modeling of long-range transport of CO2. In this study, four approaches are used to filter the atmospheric CO2 observation records from 2009 to 2011 at one World Meteorological Organization/Global Atmosphere Watch (WMO/GAW) regional station (Lin'an, LAN) in China. The methods are based on the atmospheric black carbon concentration (BC), on a statistical approach (REBS), on CH4 as auxiliary tracer (AUX) and on meteorological parameters (MET). All approaches do suitably well to capture the seasonal CO2 cycle at LAN. Differences are observed in the average regional mole fractions with annual values in the REBS method at least 1.7 ± 0.2 ppm higher than the other methods. The BC method may underestimate the regional CO2 mole fractions during winter-spring period and should be treated with caution. The REBS method is a purely statistical method and it may also introduce errors on the regional CO2 mole fractions evaluations, as the filtered trend may be deviated by the "noisy" raw data series. Although there are correlations between CH4 and CO2 mole fractions at LAN, the different source/sink regimes may introduce bias on the regional CO2 estimation in the AUX method, typically in summer. Overall, the MET method seems to be the most favorable because it mainly focuses on the influence of potential local sources and sinks and considers diurnal variations, local topography, and meteorological conditions. Using the MET method, the annual growth rate of regional CO2 at LAN is determined to be 3.1 ± 0.01 ppm yr-1 (standard error) from 2009 to 2013.

  11. [Baroreflex activation therapy. A novel interventional approach to treat heart failure with reduced ejection fraction].

    PubMed

    Halbach, M; Fritz, T; Madershahian, N; Pfister, R; Reuter, H

    2015-11-01

    Sympathovagal imbalance plays an important role in the progression of heart failure with reduced ejection fraction. Baroreflex activation therapy (BAT), i. e. electrical stimulation of baroreceptors located at the carotid sinus, can reduce sympathetic and enhance parasympathetic tone. Large animal studies on BAT demonstrated improvements in cardiac function, arrhythmogenic risk and a survival benefit compared to untreated controls. The recently published Neo Randomized Heart Failure Study, the first multicenter, randomized and controlled trial of optimal medical and device therapy alone or plus BAT in patients with a left ventricular ejection fraction ≤ 35 %, demonstrated a reasonable safety profile of BAT in this severely ill patient population and no relevant interactions with other devices. The study found significant improvements in the New York Heart Association (NYHA) class of heart failure, quality of life as well as 6 min walking distance and data pointed to a reduction in hospitalization rates. Moreover, N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were significantly reduced. This review gives an overview on BAT for the treatment of heart failure with reduced ejection fraction, from the rationale and animal experiments to the most recent clinical data and future perspectives.

  12. Low pressure premixed CH4/air flames with forced periodic mixture fraction oscillations: experimental approach

    NASA Astrophysics Data System (ADS)

    Ax, H.; Kutne, P.; Meier, W.; König, K.; Maas, U.; Class, A.; Aigner, M.

    2009-03-01

    An experimental setup for the generation and investigation of periodic equivalence ratio oscillations in laminar premixed flames is presented. A special low-pressure burner was developed which generates stable flames in a wide pressure range down to 20 mbar and provides the possibility of rapid mixture fraction variations. The technical realization of the mixture fraction variations and the characteristics of the burner are described. 1D laser Raman scattering was applied to determine the temperature and concentration profiles of the major species through the flame front in correlation to the phase-angle of the periodic oscillation. OH* chemiluminescence was detected to qualitatively analyze the response of the flame to mixture fraction variations by changing shape and position. Exemplary results from a flame at p=69 mbar, forced at a frequency of 10 Hz, are shown and discussed. The experiments are part of a cooperative research project including the development of kinetic models and numerical simulation tools with the aim of a better understanding and prediction of periodic combustion instabilities in gas turbines. The focus of the current paper lies on the presentation of the experimental realization and the measuring techniques.

  13. Development of a toxicity-based fractionation approach for the identification of phototoxic PAHs in pore water

    SciTech Connect

    Kosian, P.A.; Makynen, E.A.; Ankley, G.T.; Monson, P.D.

    1995-12-31

    Environmental matrices often contain complex mixtures of chemical compounds, however, typically only a few chemicals are responsible for observed toxicity. To determine those chemicals responsible for toxicity, a toxicity-based fractionation technique coupled with gas chromatography/mass spectrometry (GC/MS) has been used for the isolation and identification of nonpolar toxicants in aqueous samples. In this study, this technique was modified to separate and identify polycyclic aromatic hydrocarbons (PAHs) responsible for phototoxicity in pore water. Whole pore water, obtained from sediments collected near an oil refinery discharge site, was found to be toxic to Lumbriculus variegatus in the presence of ultraviolet (UV) light. Solid phase extraction disks and high pressure liquid chromatography were used, in conjunction with toxicity tests with L. variegatus, to extract and fractionate phototoxic chemicals from the pore water. GC/MS analysis was performed on the toxic fractions and a tentative list of compound identifications were made based on interpretation of mass spectra and elution information from the chromatographic separation. The compounds identified include PAHs and substituted PAHs that are known or predicted to be phototoxic in the presence of UV light. The results show that a modified toxicity-based fractionation approach can be successfully applied to identify phototoxic PAHs in sediment pore water and therefore used in the assessment of contaminated sediments.

  14. Intake port

    DOEpatents

    Mendler, Edward Charles

    2005-02-01

    The volumetric efficiency and power of internal combustion engines is improved with an intake port having an intake nozzle, a venturi, and a surge chamber. The venturi is located almost halfway upstream the intake port between the intake valves and the intake plenum enabling the venturi throat diameter to be exceptionally small for providing an exceptionally high ram velocity and an exceptionally long and in turn high efficiency diffuser flowing into the surge chamber. The intake port includes an exceptionally large surge chamber volume for blow down of the intake air into the working cylinder of the engine.

  15. Traditional nutritional analyses of figs overestimates intake of most nutrient fractions: a study of ficus perforata consumed by howler monkeys (Alouatta palliata mexicana).

    PubMed

    Urquiza-Haas, Tania; Serio-Silva, Juan Carlos; Hernández-Salazar, Laura Teresa

    2008-05-01

    There continue to remain uncertainty concerning the nutritional importance of figs (Ficus spp.) in the primate diet. Although studies have been performed on the nutritional analysis of fig pulp and seed fractions separately, there has not been an attempt to quantify the contribution of animal matter within figs. Here we report nutritional values of figs (Ficus perforata) (Urostigma) consumed by a troop of howler monkeys (Alouatta palliata mexicana). Separate nutritional assays were performed on the pulp, seed, and animal fraction. Whole-fig analyses significantly exaggerate the concentrations of all nutrients (lipids especially) as seeds, which represent a large proportion of the fig (45%), cannot be digested. Animal matter only represents 1% of the fig, and augments fig protein and lipid content by 0.44 and 0.30%, respectively. This represents the 11 and 9% of the fraction available for digestion. Differences in fig consumption were observed between age and sex classes (P=0.04) and periods of the day (P=0.001); females consumed more figs than males and the highest consumption of figs was observed in the afternoon. F. perforata figs may be an important component of the howler monkeys diet owing to their high content of water and calcium.

  16. Gut feedback mechanisms and food intake: a physiological approach to slow carbohydrate bioavailability.

    PubMed

    Zhang, Genyi; Hasek, Like Y; Lee, Byung-Hoo; Hamaker, Bruce R

    2015-04-01

    Glycemic carbohydrates in foods are an important macronutrient providing the biological fuel of glucose for a variety of physiological processes. A classification of glycemic carbohydrates into rapidly digestible carbohydrate (RDC) and slowly digestible carbohydrate (SDC) has been used to specify their nutritional quality related to glucose homeostasis that is essential to normal functioning of the brain and critical to life. Although there have been many studies and reviews on slowly digestible starch (SDS) and SDC, the mechanisms of their slow digestion and absorption were mostly investigated from the material side without considering the physiological processes of their in vivo digestion, absorption, and most importantly interactions with other food components and the gastrointestinal tract. In this article, the physiological processes modulating the bioavailability of carbohydrates, specifically the rate and extent of their digestion and absorption as well as the related locations, in a whole food context, will be discussed by focusing on the activities of the gastrointestinal tract including glycolytic enzymes and glucose release, sugar sensing, gut hormones, and neurohormonal negative feedback mechanisms. It is hoped that a deep understanding of these physiological processes will facilitate the development of innovative dietary approaches to achieve desired carbohydrate or glucose bioavailability for improved health.

  17. Conformational effect of dicyclo-hexano-18-crown-6 on isotopic fractionation of zinc: DFT approach

    SciTech Connect

    Boda, A.; Singha Deb, A. K.; Ali, Sk. M.; Shenoy, K. T.; Ghosh, S. K.

    2014-04-24

    Generalized gradient approximated BP86 density functional employing triple zeta valence plus polarization (TZVP) basis set has been used to compute the reduced partition function ratio and isotopic separation factor for zinc isotopes. The isotopic separation factor was found to be in good agreement with the experimental results. The isotopic separation factor was found to depend on the conformation of the crown ether ligand. The trans-trans conformation shows the highest fractionation compared to cis-cis conformer. The present theoretical results can thus be used to plan the isotope separation experiments.

  18. A novel fractionation approach for water constituents – distribution of storm event metals

    PubMed Central

    McKenzie, Erica R.; Young, Thomas M.

    2014-01-01

    A novel fractionation method, based on both particle size and settling characteristics, was employed to examine metal distributions among five fractions. In-stream and stormwater runoff samples were collected from four land use types: highway, urban, agricultural (storm event and irrigation), and natural. Highway samples contained the highest dissolved concentrations for most metals, and freshwater ambient water quality criteria were exceeded for Cd, Cu, Pb, and Zn in the first storm of the water year. Anthropogenic sources were indicated for Cu, Zn, Cd, and Pb in highway and urban samples, and total metal loadings (mg/km2) were observed to be as follows: highway > urban > agricultural storm event ~ natural > agricultural irrigation. Notably, ~10-fold higher suspended solids concentration was observed in the agricultural storm event sample, and suspended solids-associated metals were correspondingly elevated. Distribution coefficients revealed the following affinities: Zn, Ni, Cd, and Pb to large dense particles; and Cu, Zn, Cr, Ni, and Pb to colloidal organic matter. PMID:23535891

  19. A Fractional PDE Approach to Turbulent Mixing; Part I: an Anomalous Transport Theory

    NASA Astrophysics Data System (ADS)

    Zayernouri, Mohsen; Samiee, Mehdi

    2016-11-01

    It has been experimentally and theoretically shown that even in the most ideal cases of homogeneous and isotropic turbulence, the statistical distributions are asymmetric and heavy-tailed. Similar observations, in addition to high peaks, have been made in grid turbulence and atmospheric boundary layer. In the aforementioned problems, the skewness, as a measure of asymmetry, is non-zero and negative, also the flatness (kurtosis), as a notion of the tail heaviness in the distribution, significantly exceeds the Gaussian value 3, reflecting a strong non-Gaussianity. In this talk, we demonstrate that the existence of such anomalous characteristics e.g., heavy tails, asymmetric distributions, and high peaks can naturally put the phenomenology of Taylor, Richardson, and Kolmogorov in broader framework, where the generalizing fractional Brownian motions and stochastic Lévy jump processes (or Lévy flights), investigated in the context of fractional PDEs in the fluid limit, can physically and mathematically explain, hence, predict the notion of anomalously enhanced (sub-to-super) diffusion and self-similar features in passive scalar turbulence. Assistant Professor, Department Computational Mathematics, Science, and Engineering, & Department of Mechanical Engineering.

  20. A proteomic approach for plasma biomarker discovery with iTRAQ labelling and OFFGEL fractionation.

    PubMed

    Ernoult, Emilie; Bourreau, Anthony; Gamelin, Erick; Guette, Catherine

    2010-01-01

    Human blood plasma contains a plethora of proteins, encompassing not only proteins that have plasma-based functionalities, but also possibly every other form of low concentrated human proteins. As it circulates through the tissues, the plasma picks up proteins that are released from their origin due to physiological events such as tissue remodeling and cell death. Specific disease processes or tumors are often characterized by plasma "signatures," which may become obvious via changes in the plasma proteome profile, for example, through over expression of proteins. However, the wide dynamic range of proteins present in plasma makes their analysis very challenging, because high-abundance proteins tend to mask those of lower abundance. In the present study, we used a strategy combining iTRAQ as a reagent which improved the peptide ionization and peptide OFFGEL fractionation that has already been shown, in our previous research, to improve the proteome coverage of cellular extracts. Two prefractioning methods were compared: immunodepletion and a bead-based library of combinatorial hexapeptide technology. Our data suggested that both methods were complementary, with regard to the number of identified proteins. iTRAQ labelling, in association with OFFGEL fractionation, allowed more than 300 different proteins to be characterized from 400 microg of plasma proteins.

  1. FRACTIONAL CRYSTALLIZATION OF HANFORD SINGLE SHELL TANK (SST) WASTES A MODELING APPROACH

    SciTech Connect

    HAMILTON, D.W.

    2006-12-21

    The Hanford site has 149 underground single-shell tanks (SST) storing mostly soluble, multi-salt, mixed wastes resulting from Cold War era weapons material production. These wastes must be retrieved and the salts immobilized before the tanks can be closed to comply with an overall site closure consent order entered into by the U.S. Department of Energy (DOE), the Environmental Protection Agency, and Washington State. Water will be used to retrieve the wastes and the resulting solution will be pumped to the proposed treatment process where a high curie (primarily {sup 137}Cs) waste fraction will be separated from the other waste constituents. The separated waste streams will then be vitrified to allow for safe storage as an immobilized high level waste, or low level waste, borosilicate glass. Fractional crystallization, a common unit operation for production of industrial chemicals and pharmaceuticals, was proposed as the method to separate the salt wastes; it works by evaporating excess water until the solubilities of various species in the solution are exceeded (the solubility of a particular species depends on its concentration, temperature of the solution, and the presence of other ionic species in the solution). By establishing the proper conditions, selected pure salts can be crystallized and separated from the radioactive liquid phase.

  2. Influence of sampling intake position on suspended solid measurements in sewers: two probability/time-series-based approaches.

    PubMed

    Sandoval, Santiago; Bertrand-Krajewski, Jean-Luc

    2016-06-01

    Total suspended solid (TSS) measurements in urban drainage systems are required for several reasons. Aiming to assess uncertainties in the mean TSS concentration due to the influence of sampling intake vertical position and vertical concentration gradients in a sewer pipe, two methods are proposed: a simplified method based on a theoretical vertical concentration profile (SM) and a time series grouping method (TSM). SM is based on flow rate and water depth time series. TSM requires additional TSS time series as input data. All time series are from the Chassieu urban catchment in Lyon, France (time series from 2007 with 2-min time step, 89 rainfall events). The probability of measuring a TSS value lower than the mean TSS along the vertical cross section (TSS underestimation) is about 0.88 with SM and about 0.64 with TSM. TSM shows more realistic TSS underestimation values (about 39 %) than SM (about 269 %). Interquartile ranges (IQR) over the probability values indicate that SM is more uncertain (IQR = 0.08) than TSM (IQR = 0.02). Differences between the two methods are mainly due to simplifications in SM (absence of TSS measurements). SM assumes a significant asymmetry of the TSS concentration profile along the vertical axis in the cross section. This is compatible with the distribution of TSS measurements found in the TSM approach. The methods provide insights towards an indicator of the measurement performance and representativeness for a TSS sampling protocol.

  3. Discretionary calorie intake a priority for obesity prevention: results of rapid participatory approaches in low-income US communities.

    PubMed

    Cohen, Deborah A; Sturm, Roland; Lara, Marielena; Gilbert, Marylou; Gee, Scott

    2010-09-01

    Since resources are limited, selecting the most promising targets for obesity interventions is critical. We examined the relative associations of physical activity, fruit and vegetable consumption and 'junk food' consumption with BMI and the prevalence of relevant policies in school, work, food outlets and health-care settings. We conducted intercept surveys in three low-income, high-minority California communities to assess fruit, vegetable, candy, cookie, salty snacks and sugar-sweetened beverage consumption and self-reported height, weight and physical activity. We also assessed relevant policies in selected worksites, schools and health-care settings through key informant interviews. Data were collected from 1826 respondents, 21 schools, 40 worksites, 14 health-care settings and 29 food outlets. The average intake of salty snacks, candy, cookies and sugar-sweetened beverages was estimated at 2226 kJ (532 kcal) daily, 88% higher than the US Department of Agriculture/Department of Health and Human Services guidelines recommend. Energy from these sources was more strongly related to BMI than reported physical activity, fruit or vegetable consumption. Policies to promote healthy eating and physical activity were limited in worksites. Fruits and vegetables were less salient than junk food in community food outlets. Targeting consumption of salty snacks, candy cookies and sugar-sweetened beverages appeared more promising than alternative approaches.

  4. A Novel Approach to Constrain the Escape Fraction and Dust Content at High Redshift Using the Cosmic Infrared Background Fractional Anisotropy

    NASA Astrophysics Data System (ADS)

    Fernandez, Elizabeth R.; Dole, Herve; Iliev, Ilian T.

    2013-02-01

    The Cosmic Infrared Background (CIB) provides an opportunity to constrain many properties of the high-redshift (z > 6) stellar population as a whole. This background, specifically from 1 to 200 μm, should contain information about the era of reionization and the stars that are responsible for these ionizing photons. In this paper, we look at the fractional anisotropy (δI/I) of this high-redshift population, where δI is the ratio of the magnitude of the fluctuations and I is the mean intensity. We show that this can be used to constrain the escape fraction of the population as a whole, because the magnitude of the fluctuations of the CIB depends on the escape fraction, while the mean intensity does not. This results in lower values of the escape fraction producing higher values of the fractional anisotropy. This difference is predicted to be larger at longer wavelength bands (above 10 μm), albeit it is also much harder to observe in that range. We show that the fractional anisotropy can also be used to separate a dusty from a dust-free population. Finally, we discuss the constraints provided by current observations on the CIB fractional anisotropy.

  5. Potential of calcium isotopes to identify fractionations in vegetation: experimental approach

    NASA Astrophysics Data System (ADS)

    Cobert, F.; Schmitt, A.; Bourgade, P.; Stille, P.; Chabaux, F. J.; Badot, P.; Jaegler, T.

    2010-12-01

    This study aims to better understand the role of vegetation on the Ca cycle at the level of the critical zone of the Earth, in order to specify the mechanisms controlling the Ca absorption by plants at the rock/plant interface. To do this, we performed experiments using hydroponic plant cultures in a way that we could control the cooccuring geochemical and biological processes and determine the impact of the nutritive solution on the Ca cycle within plants. A dicotyledon and calcicole plant with rapid growth, the French bean (Phaseolus vulgaris L.), has been chosen to have access to one complete growth cycle. Several experiments have been conducted with two Ca concentrations, 5 (L) and 60 (H) ppm and two pH values (4 and 6) in the nutritive solution, for which the Ca concentration was maintained constant, so its Ca content is considered to be infinite. We determined Ca concentrations and isotopic ratios in the nutritive solution and in different organs (main roots, secondary roots, old and young stems, old and young leaves and fruits) at two different growth stages (10 days and 6 weeks). Our results show, in accord with previously published field studies, that the bean organs are all enriched in the light 40Ca isotope compared to the nutritive solution (e.g. Wigand et al., 2005; Page et al., 2008; Cenki-Tok et al., 2009; Holmden and Bélanger, 2010). We identify two fractionation levels. The first occurs during the uptake of the nutrient elements by the lateral roots. This implies that the main mechanisms of light isotope enrichments in the plant are due to electrochemical gradient transport processes taking place at this interface. The second fractionation can be observed within the plant itself and is due to the nature of the considered organ itself. Indeed structural reservoirs (primary roots, stem, reproductive organs) incorporate more the light 40Ca isotope compared to the transfer reservoirs (lateral roots, xylem sap, leaves). This could be linked to ion

  6. Condition-based diagnosis of mechatronic systems using a fractional calculus approach

    NASA Astrophysics Data System (ADS)

    Gutiérrez-Carvajal, Ricardo Enrique; Flávio de Melo, Leonimer; Maurício Rosário, João; Tenreiro Machado, J. A.

    2016-07-01

    While fractional calculus (FC) is as old as integer calculus, its application has been mainly restricted to mathematics. However, many real systems are better described using FC equations than with integer models. FC is a suitable tool for describing systems characterised by their fractal nature, long-term memory and chaotic behaviour. It is a promising methodology for failure analysis and modelling, since the behaviour of a failing system depends on factors that increase the model's complexity. This paper explores the proficiency of FC in modelling complex behaviour by tuning only a few parameters. This work proposes a novel two-step strategy for diagnosis, first modelling common failure conditions and, second, by comparing these models with real machine signals and using the difference to feed a computational classifier. Our proposal is validated using an electrical motor coupled with a mechanical gear reducer.

  7. A Physiographic Approach to Downscaling Remotely Sensed Fractional Snow Cover Data

    NASA Astrophysics Data System (ADS)

    Walters, R. D.; Watson, K. A.; Flores, A. N.

    2012-12-01

    Improved characterization of hydrologic states like soil moisture and snow water equivalent at scales of individual hillslopes (i.e., 10s to 100s of meters) would substantially benefit applications ranging from flood-forecasting to military trafficability assessment. In seasonally snow-covered mountain watersheds, complex topography influences the evolution of areal snow cover. Various satellite remote sensing data are able to capture the extent of snow covered area with spatial or temporal limitations depending on the particular product. For instance, the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor, aboard Terra and Aqua satellites, produces fractional snow covered area (fSCA) grids daily but with 500-m spatial resolution. Conversely, the Landsat system can estimate binary snow cover at 30-m spacing but only on a 16-day return interval. Since variable snow ablation occurs within these spatiotemporal boundaries, it is desirable to estimate the snow cover at higher resolution. Here we propose a simple method to downscale daily MODIS fSCA data to 30-m resolution binary snow cover estimates. The algorithm computes a terrain score as a linear weighted average of two physiographic variables: elevation and relative insolation slope factor. Shuttle Radar Topography Mission (SRTM) data (30-m, co-registered with Landsat) are used to extract the elevation and to compute the radiation data. Under the assumption that low-elevation and high-insolation pixels will have melted first in an ephemeral snowpack, cells within each MODIS window are assigned a binary snow cover classification such that the fSCA observation is satisfied. Terrain score weights are optimized according to historical Landsat scenes within regions of southwestern Idaho. Blind test results in the same regions show good model performance (< 10%) when MODIS and Landsat are in agreement regarding snow cover fraction. The model is thus at the mercy of fSCA accuracy and may not perform as well when

  8. A novel approach to improve operation and performance in flow field-flow fractionation.

    PubMed

    Johann, Christoph; Elsenberg, Stephan; Roesch, Ulrich; Rambaldi, Diana C; Zattoni, Andrea; Reschiglian, Pierluigi

    2011-07-08

    A new system design and setup are proposed for the combined use of asymmetrical flow field-flow fractionation (AF4) and hollow-fiber flow field-flow fractionation (HF5) within the same instrumentation. To this purpose, three innovations are presented: (a) a new flow control scheme where focusing flow rates are measured in real time allowing to adjust the flow rate ratio as desired; (b) a new HF5 channel design consisting of two sets of ferrule, gasket and cap nut used to mount the fiber inside a tube. This design provides a mechanism for effective and straightforward sealing of the fiber; (c) a new AF4 channel design with only two fluid connections on the upper plate. Only one pump is needed to deliver the necessary flow rates. In the focusing/relaxation step the two parts of the focusing flow and a bypass flow flushing the detectors are created with two splits of the flow from the pump. In the elution mode the cross-flow is measured and controlled with a flow controller device. This leads to reduced pressure pulsations in the channel and improves signal to noise ratio in the detectors. Experimental results of the separation of bovine serum albumin (BSA) and of a mix of four proteins demonstrate a significant improvement in the HF5 separation performance, in terms of efficiency, resolution, and run-to-run reproducibility compared to what has been reported in the literature. Separation performance in HF5 mode is shown to be comparable to the performance in AF4 mode using a channel with two connections in the upper plate.

  9. Application of Liquid Chromatography-Tandem Mass Spectrometry To Determine Urinary Concentrations of Five Commonly Used Low-Calorie Sweeteners: A Novel Biomarker Approach for Assessing Recent Intakes?

    PubMed

    Logue, Caomhan; Dowey, Le Roy C; Strain, J J; Verhagen, Hans; McClean, Stephen; Gallagher, Alison M

    2017-06-07

    Although the use of low-calorie sweeteners (LCSs) is widespread, methods of assessing consumption within free-living populations have inherent limitations. Five commonly consumed LCSs, namely, acesulfame-K, saccharin, sucralose, cyclamate, and steviol glycosides, are excreted via the urine, and therefore a urinary biomarker approach may provide more objective LCS intake data. A LC-ESI-MS/MS method of simultaneously determining acesulfame-K, saccharin, sucralose, cyclamate, and the excretory metabolite of steviol glycosides, steviol glucuronide, in human urine was developed and validated. Linearity was observed over a concentration range of 10-1000 ng/mL with coefficients of determination ranging from 0.9969 to 0.9997. Accuracy ranged from 92 to 104%, and intrabatch and interday precisions were within acceptable limits with %CV below 8% for all compounds. A double-blind, randomized crossover dose-response study was conducted to assess the usefulness of urinary LCS excretions (from both fasting spot and a full 24-h urine collection) for investigating recent intakes. Both modes of sampling were useful for distinguishing between the three short-term intakes of acesulfame-K, saccharin, cyclamates, and steviol glycosides (p < 0.001), whereas for sucralose, urinary concentrations were useful for distinguishing between low (0.1% ADI) and high doses (10% ADI) only (p < 0.001). In summary, this biomarker approach may be useful for assessing intakes of five commonly consumed LCSs.

  10. A conformal mapping based fractional order approach for sub-optimal tuning of PID controllers with guaranteed dominant pole placement

    NASA Astrophysics Data System (ADS)

    Saha, Suman; Das, Saptarshi; Das, Shantanu; Gupta, Amitava

    2012-09-01

    A novel conformal mapping based fractional order (FO) methodology is developed in this paper for tuning existing classical (Integer Order) Proportional Integral Derivative (PID) controllers especially for sluggish and oscillatory second order systems. The conventional pole placement tuning via Linear Quadratic Regulator (LQR) method is extended for open loop oscillatory systems as well. The locations of the open loop zeros of a fractional order PID (FOPID or PIλDμ) controller have been approximated in this paper vis-à-vis a LQR tuned conventional integer order PID controller, to achieve equivalent integer order PID control system. This approach eases the implementation of analog/digital realization of a FOPID controller with its integer order counterpart along with the advantages of fractional order controller preserved. It is shown here in the paper that decrease in the integro-differential operators of the FOPID/PIλDμ controller pushes the open loop zeros of the equivalent PID controller towards greater damping regions which gives a trajectory of the controller zeros and dominant closed loop poles. This trajectory is termed as "M-curve". This phenomena is used to design a two-stage tuning algorithm which reduces the existing PID controller's effort in a significant manner compared to that with a single stage LQR based pole placement method at a desired closed loop damping and frequency.

  11. A new approach to quantitatively describe permafrost core using multi-energy CT scanning: composition fraction and morphological analysis

    NASA Astrophysics Data System (ADS)

    Chang, C.; McKnight, C.; Kneafsey, T. J.

    2014-12-01

    Composition discernment, fraction calculation and morphological analysis of a shallow core retrieved from Barrow, AK as part of the Next Generation Ecosystem Experiments in the Arctic (NGEE-Arctic) were conducted to give a quantitative description of the core. Imaging of the core was performed using a medical X-ray computed tomography (CT) scanner, which gives a 3D image with a resolution of 0.195×0.195×0.625mm3. The core consists mainly of mineral, ice, organic matter and air and composition discernment and fraction calculation focus on the first three materials. Four scans with different energies were performed because materials with different density show different responses on scans with varying energies. A calibration curve showing the relationship between density and CT value was built by scanning standard materials having a wide range of density. CT value of the three compositions under four energies was determined by the calibration curve and the core scan. Composition fraction was calculated on the assumption that the core CT value is linearly proportional to the composition fraction and by solving linear least-squares problems with bounds. Comparison of the estimated and measured core CT value shows that the correlation coefficient is more than 0.99, indicating the accuracy of the calculation. Two regions with relatively high fraction of organic matter (10%) were distinguished, which are located at the top of the core and ice filled fractures at the bottom of the active layer. Morphological analysis was applied to the mineral and ice because of low fraction of organic matter. Three segmentations corresponding to ice-rich (with a density of 0.86 to 1.24 g/cm3), transition from ice to mineral (1.24 to 1.47 g/cm3) and mineral-rich (1.47 to 2.65 g/cm3) were applied to the core, and two area (area and area standard deviation) and three morphological (circulatory, roundness and rectangularity) parameters were analysed. By conducting Principle Component

  12. Equilibrium Tin Isotope Fractionation during Metal-Sulfide-Silicate Differentiation: A Nuclear Resonant Inelastic X-ray Scattering Approach

    NASA Astrophysics Data System (ADS)

    Roskosz, M.; Amet, Q.; Fitoussi, C.; Laporte, D.; Hu, M. Y.; Alp, E. E.

    2016-12-01

    Metal-silicate differentiation was recently addressed through the insight of the isotopic composition of siderophile elements (mainly Fe, Si and Cr isotopes) of planetary and extraterrestrial bodies. A key limitation of this approach is however the knowledge of equilibrium fractionation factors between coexisting phases (metal alloys, silicates and sulfides) used to interpret data on natural samples. These properties are difficult to determine experimentally. In this context, tin is generally classified as a chalcophile element but it is also siderophile and volatile. We applied a synchrotron-based method to circumvent difficulties related to determination of equilibrium isotope fractionation. The nuclear resonant inelastic x-ray scattering (NRIXS) was used to measure the phonon excitation spectrum and then to derive the force constant and finally the fractionation factors of Sn-bearing geomaterials. Spectroscopic measurements were carried out at room pressure at Sector 30-ID (APS, USA). A range of Fe-Ni alloys, rhyolitic and basaltic glasses and iron sulfides containing isotopically enriched 119Sn were synthesized. The tin content and the redox conditions prevailing during the synthesis were varied. The data evaluation was carried out using PHOENIX and SciPhon programs. A strong effect of both the redox state and the tin content was measured. In addition, the composition of the silicate glasses was found to be another important factor determining the tin isotope metal-silicate-sulfide fractionation factors. Our results are consistent with trends previously observed in the case of iron isotopes [1,2]. We will discuss the implications of our experimental results in terms of tin isotope planetary signatures. References: [1] Dauphas et al. (2014), EPSL, 398, 127-140; [2] Roskosz et al. (2015), GCA, 169, 184-199.

  13. Fate and mass balance of contaminants of emerging concern during wastewater treatment determined using the fractionated approach.

    PubMed

    Baalbaki, Zeina; Sultana, Tamanna; Maere, Thomas; Vanrolleghem, Peter A; Metcalfe, Chris D; Yargeau, Viviane

    2016-12-15

    Contaminants of emerging concern (CECs) are often poorly removed from wastewater using conventional treatment technologies and there is limited understanding of their fate during treatment. Inappropriate sampling strategies lead to inaccuracies in estimating removals of CECs. In this study, we used the "fractionated approach" that accounts for the residence time distribution (RTD) in treatment units to investigate the fate of 26 target CECs in a municipal wastewater treatment plant (WWTP) that includes primary, secondary and tertiary treatment steps. Prior hydraulic calibration of each treatment unit was performed. Wastewater and sludge samples were collected at different locations along the treatment train and the concentrations of target CECs were measured by liquid chromatography mass spectrometry. The most substantial aqueous removal occurred during activated sludge treatment (up to 99%). Removals were <50% in the primary clarifier and tertiary rotating biological contactors (RBCs) and up to 70% by sand filtration. Mass balance calculations demonstrated that (bio)degradation accounted for up to 50% of the removal in the primary clarifier and 100% in activated sludge. Removal by sorption to primary and secondary sludge was minimal for most CECs. Analysis of the selected metabolites demonstrated that negative removals obtained could be explained by transformations between the parent compound and their metabolites. This study contributes to the growing literature by applying the fractionated approach to calculate removal of different types of CECs across each wastewater treatment step. An additional level of understanding of the fate of CECs was provided by mass balance calculations in primary and secondary treatments.

  14. Numerical Solution of Incompressible Navier-Stokes Equations Using a Fractional-Step Approach

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Kwak, Dochan

    1999-01-01

    A fractional step method for the solution of steady and unsteady incompressible Navier-Stokes equations is outlined. The method is based on a finite volume formulation and uses the pressure in the cell center and the mass fluxes across the faces of each cell as dependent variables. Implicit treatment of convective and viscous terms in the momentum equations enables the numerical stability restrictions to be relaxed. The linearization error in the implicit solution of momentum equations is reduced by using three subiterations in order to achieve second order temporal accuracy for time-accurate calculations. In spatial discretizations of the momentum equations, a high-order (3rd and 5th) flux-difference splitting for the convective terms and a second-order central difference for the viscous terms are used. The resulting algebraic equations are solved with a line-relaxation scheme which allows the use of large time step. A four color ZEBRA scheme is employed after the line-relaxation procedure in the solution of the Poisson equation for pressure. This procedure is applied to a Couette flow problem using a distorted computational grid to show that the method minimizes grid effects. Additional benchmark cases include the unsteady laminar flow over a circular cylinder for Reynolds Numbers of 200, and a 3-D, steady, turbulent wingtip vortex wake propagation study. The solution algorithm does a very good job in resolving the vortex core when 5th-order upwind differencing and a modified production term in the Baldwin-Barth one-equation turbulence model are used with adequate grid resolution.

  15. Estimates of the theoretical maximum daily intake of erythorbic acid, gallates, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) in Italy: a stepwise approach.

    PubMed

    Leclercq, C; Arcella, D; Turrini, A

    2000-12-01

    The three recent EU directives which fixed maximum permitted levels (MPL) for food additives for all member states also include the general obligation to establish national systems for monitoring the intake of these substances in order to evaluate their use safety. In this work, we considered additives with primary antioxidant technological function for which an acceptable daily intake (ADI) was established by the Scientific Committee for Food (SCF): gallates, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and erythorbic acid. The potential intake of these additives in Italy was estimated by means of a hierarchical approach using, step by step, more refined methods. The likelihood of the current ADI to be exceeded was very low for erythorbic acid, BHA and gallates. On the other hand, the theoretical maximum daily intake (TMDI) of BHT was above the current ADI. The three food categories found to be main potential sources of BHT were "pastry, cake and biscuits", "chewing gums" and "vegetables oils and margarine"; they overall contributed 74% of the TMDI. Actual use of BHT in these food categories is discussed, together with other aspects such as losses of this substance in the technological process and percentage of ingestion in the case of chewing gums.

  16. A treatment planning approach to spatially fractionated megavoltage grid therapy for bulky lung cancer

    SciTech Connect

    Costlow, Heather N.; Zhang, Hualin; Das, Indra J.

    2014-10-01

    The purpose of this study was to explore the treatment planning methods of spatially fractionated megavoltage grid therapy for treating bulky lung tumors using multileaf collimator (MLC). A total of 5 patients with lung cancer who had gross tumor volumes ranging from 277 to 635 cm{sup 3} were retrospectively chosen for this study. The tumors were from 6.5 to 9.6 cm at shortest dimension. Several techniques using either electronic compensation or intensity-modulated radiation therapy (IMRT) were used to create a variety of grid therapy plans on the Eclipse treatment planning system. The dose prescription point was calculated to the volume, and a dose of 20 Gy with 6-MV/15-MV beams was used in each plan. The dose-volume histogram (DVH) curves were obtained to evaluate dosimetric characteristics. In addition, DVH curves from a commercially available cerrobend grid collimator were also used for comparison. The linear-quadratic radiobiological response model was used to assess therapeutic ratios (TRs) and equivalent uniform doses (EUD) for all generated plans. A total of 6 different grid therapy plans were created for each patient. Overall, 4 plans had different electronic compensation techniques: Ecomps-Tubes, Ecomps-Circles, Ecomps-Squares, and Ecomps-Weave; the other 2 plans used IMRT and IMRT-Weave techniques. The DVH curves and TRs demonstrated that these MLC-based grid therapy plans can achieve dosimetric properties very similar to those of the cerrobend grid collimator. However, the MLC-based plans have larger EUDs than those with the cerrobend grid collimator. In addition, the field shaping can be performed for targets of any shape in MLC-based plans. Thus, they can deliver a more conformal dose to the targets and spare normal structures better than the cerrobend grid collimator can. The plans generated by the MLC technique demonstrated the advantage over the standard cerrobend grid collimator on accommodating targets and sparing normal structures. Overall, 6

  17. SU-E-T-549: A Combinatorial Optimization Approach to Treatment Planning with Non-Uniform Fractions in Intensity Modulated Proton Therapy

    SciTech Connect

    Papp, D; Unkelbach, J

    2014-06-01

    Purpose: Non-uniform fractionation, i.e. delivering distinct dose distributions in two subsequent fractions, can potentially improve outcomes by increasing biological dose to the target without increasing dose to healthy tissues. This is possible if both fractions deliver a similar dose to normal tissues (exploit the fractionation effect) but high single fraction doses to subvolumes of the target (hypofractionation). Optimization of such treatment plans can be formulated using biological equivalent dose (BED), but leads to intractable nonconvex optimization problems. We introduce a novel optimization approach to address this challenge. Methods: We first optimize a reference IMPT plan using standard techniques that delivers a homogeneous target dose in both fractions. The method then divides the pencil beams into two sets, which are assigned to either fraction one or fraction two. The total intensity of each pencil beam, and therefore the physical dose, remains unchanged compared to the reference plan. The objectives are to maximize the mean BED in the target and to minimize the mean BED in normal tissues, which is a quadratic function of the pencil beam weights. The optimal reassignment of pencil beams to one of the two fractions is formulated as a binary quadratic optimization problem. A near-optimal solution to this problem can be obtained by convex relaxation and randomized rounding. Results: The method is demonstrated for a large arteriovenous malformation (AVM) case treated in two fractions. The algorithm yields a treatment plan, which delivers a high dose to parts of the AVM in one of the fractions, but similar doses in both fractions to the normal brain tissue adjacent to the AVM. Using the approach, the mean BED in the target was increased by approximately 10% compared to what would have been possible with a uniform reference plan for the same normal tissue mean BED.

  18. The effects of calcium hydroxide-treated whole-plant and fractionated corn silage on intake, digestion, and lactation performance in dairy cows.

    PubMed

    Cook, D E; Bender, R W; Shinners, K J; Combs, D K

    2016-07-01

    The objective of this trial was to evaluate, in dairy cattle, the effects of calcium hydroxide treatment of whole-plant corn and a treatment applied to the bottom stalk fraction of the corn plant, achieved by harvesting corn in 2 crop streams. The treatments were calcium hydroxide-treated corn silage (TRTCS), toplage supplemented with calcium hydroxide-treated stalklage (TPL), a positive control of brown midrib corn silage (BMR), and a negative control of conventional whole-plant corn silage (WPCS). The toplage was harvested at a height of 82 cm with 2 of the 6 rows set as ear-snapping to incorporate higher tissues into the stalklage. Stalklage was harvested at 12 cm, and other corn silages were harvested at 27 cm. Sixteen pens, each with 8 Holstein cows averaging 70±25 d in milk and 46±11 kg of milk d(-1), were assigned 4 per treatment in a completely randomized design. The diet was approximately 40% corn silage, 20% alfalfa silage, and 40% concentrate on a dry matter basis. A 2-wk covariate period with conventional corn silage was followed by an 8-wk treatment period in which the 4 corn silage treatments were the only effective difference in diets. Cows fed TPL and TRTCS consumed more (1.9 and 1.4 kg of organic matter d(-1), respectively) than did cows fed WPCS. Milk yield was greater for cows fed BMR, TPL, and TRTCS. Cows fed BMR and TPL produced 2.9 and 2.7 kg d(-1), respectively, more energy-corrected milk (ECM) than cows fed WPCS, and cows fed TRTCS had the greatest ECM production (4.8 kg of ECM d(-1) greater than cows fed WPCS). No differences in body weight or body condition scored were observed. Milk fat concentration was similar among treatments and milk protein concentration was reduced for TRTCS. Starch and neutral detergent fiber digestibility were greater for cows fed TRTCS. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  19. Novel approach with fractional ultrapulse CO2 laser for the treatment of upper eyelid dermatochalasis and periorbital rejuvenation.

    PubMed

    Balzani, Alberto; Chilgar, Ram M; Nicoli, Marzia; Sapountzis, Stamatis; Lazzeri, Davide; Cervelli, Valerio; Nicoli, Fabio

    2013-11-01

    Fractional ultrapulse CO2 laser resurfacing improves photodamage, wrinkles, and acne scarring by ablation of damaged tissue with subsequent regeneration and remodeling of collagen. In this study, the authors examined the efficacy and safety of fractional CO2 laser and introduce a novel approach to the treatment of upper eyelid dermatochalasis. We treated 20 patients with low and moderate upper eyelid dermatochalasis. We did photographic analysis of results by measuring distance of upper eyelid fold and lateral eyebrow in vertical axis from a horizontal line joining medial and lateral canthi. All patients underwent UltraPulse CO2 laser (Microxel MX 7000) resurfacing at upper eyelid, superior to eyebrow, and in periorbital area. Measurements were taken before and at 3 and 6 months after the laser treatment. We evaluated results at 3 and 6 months after laser treatment and found that the UltraPulse CO2 laser induced elevation of eyelid crease and brow position (1.62 ± 0.69 and 2.110 ± 0.66 mm at 3 months; 1.63 ± 0.68 and 2.300 ± 0.67 mm at 6 months, respectively) as compared to before the treatment. Side effects were mild, patients reported minor crusting and oozing that resolved within 48 to 72 h, edema (1-2 days), and moderate postoperative erythema resolved within 4 days. These data illustrate the safety and efficacy of fractional ultrapulse CO2 laser in the treatment of low and moderate upper eyelid dermatochalasis with added advantage of nonsurgical brow lift.

  20. A validation of a thermal inertia approach to map soil water content on soils characterized by low fractional cover

    NASA Astrophysics Data System (ADS)

    Maltese, Antonino; Capodici, Fulvio; La Loggia, Goffredo; Corbari, Chiara; Mancini, Marco

    2013-10-01

    The assessment of the spatial distribution of soil water content could improve the effectiveness of agro-hydrological models. Although it is possible to retrieve the spatial distribution of the soil water content using thermal inertia, the main limit is its applicability to bare soils only. Recently, a variation of the thermal inertia approach has been setup also on vegetated soils characterized by low fractional cover. In particular, the methodology proposes to attenuate the solar radiation at the top of the canopy to the one reaching the soil trough an extinction factor. In situ data were acquired in June 2011 and July 2012 over two fields of maize and sunflowers; both were at their early growing stages. An airborneplatform provided images in the visible/near infrared and thermal infrared, both in day and night time. Results of the 2011 experiment demonstrated that the vegetation cover correction is required even with low fractional cover; indeed, not applying this correction would results in strong overestimation. The 2012 experiment (REFLEX) further validates the model on an independent dataset, thus, confirming the reliability of the methodology. Furthermore, a spatial resolution analysis highlighted that retrievals at low spatial resolution best compares with in situsoil water content than those obtained at high-resolution. Finally, the availability of a thermal image acquired after irrigating demonstrated the unreliability of the method when soil water content significantly changes between the two thermal acquisitions.

  1. An approach to optimize sample preparation for MALDI imaging MS of FFPE sections using fractional factorial design of experiments.

    PubMed

    Oetjen, Janina; Lachmund, Delf; Palmer, Andrew; Alexandrov, Theodore; Becker, Michael; Boskamp, Tobias; Maass, Peter

    2016-09-01

    A standardized workflow for matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI imaging MS) is a prerequisite for the routine use of this promising technology in clinical applications. We present an approach to develop standard operating procedures for MALDI imaging MS sample preparation of formalin-fixed and paraffin-embedded (FFPE) tissue sections based on a novel quantitative measure of dataset quality. To cover many parts of the complex workflow and simultaneously test several parameters, experiments were planned according to a fractional factorial design of experiments (DoE). The effect of ten different experiment parameters was investigated in two distinct DoE sets, each consisting of eight experiments. FFPE rat brain sections were used as standard material because of low biological variance. The mean peak intensity and a recently proposed spatial complexity measure were calculated for a list of 26 predefined peptides obtained by in silico digestion of five different proteins and served as quality criteria. A five-way analysis of variance (ANOVA) was applied on the final scores to retrieve a ranking of experiment parameters with increasing impact on data variance. Graphical abstract MALDI imaging experiments were planned according to fractional factorial design of experiments for the parameters under study. Selected peptide images were evaluated by the chosen quality metric (structure and intensity for a given peak list), and the calculated values were used as an input for the ANOVA. The parameters with the highest impact on the quality were deduced and SOPs recommended.

  2. A new fractional wavelet approach for the simultaneous determination of ampicillin sodium and sulbactam sodium in a binary mixture

    NASA Astrophysics Data System (ADS)

    Dinç, Erdal; Baleanu, Dumitru

    2006-03-01

    A new application of the fractional wavelet transform (FWT) was proposed for the simultaneous determination of ampicillin (AP) and sulbactam (SB) in a pharmaceutical combination for injection. FWT approach is a new powerful tool for removing noise and irrelevant information from the absorption spectra. Cardinal information having higher peak amplitude, eliminated noise, sharp peaks with shrinking width of spectral range was obtained by the application of FWT procedure to the original absorption spectra. In this paper, FWT approach was subjected to the data vector of the UV-signals obtained from AP and SB in the wavelength range of 211.5-313.8 nm. Derivative transform was applied to the original absorption signal together with its FWT generalization. The calibration graphs for AP and SB were obtained by measuring the FWT and usual derivative amplitudes at zero-crossing points. The method validation was carried out by using the synthetic mixture analysis. Our proposed FWT approach was compared with the usual derivative spectrophotometry and chemometric methods (CLS, PCR and PLS) and a good agreement was reported.

  3. Re-fraction: a machine learning approach for deterministic identification of protein homologues and splice variants in large-scale MS-based proteomics.

    PubMed

    Yang, Pengyi; Humphrey, Sean J; Fazakerley, Daniel J; Prior, Matthew J; Yang, Guang; James, David E; Yang, Jean Yee-Hwa

    2012-05-04

    A key step in the analysis of mass spectrometry (MS)-based proteomics data is the inference of proteins from identified peptide sequences. Here we describe Re-Fraction, a novel machine learning algorithm that enhances deterministic protein identification. Re-Fraction utilizes several protein physical properties to assign proteins to expected protein fractions that comprise large-scale MS-based proteomics data. This information is then used to appropriately assign peptides to specific proteins. This approach is sensitive, highly specific, and computationally efficient. We provide algorithms and source code for the current version of Re-Fraction, which accepts output tables from the MaxQuant environment. Nevertheless, the principles behind Re-Fraction can be applied to other protein identification pipelines where data are generated from samples fractionated at the protein level. We demonstrate the utility of this approach through reanalysis of data from a previously published study and generate lists of proteins deterministically identified by Re-Fraction that were previously only identified as members of a protein group. We find that this approach is particularly useful in resolving protein groups composed of splice variants and homologues, which are frequently expressed in a cell- or tissue-specific manner and may have important biological consequences.

  4. 78 FR 20672 - Literature Review Approach “Identifying Research Needs for Assessing Safe Use of High Intakes of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-05

    ... available on the NTP Folic Acid Request for Information (RFI) Web site ( http://ntp.niehs.nih.gov/go/38143... should be submitted at http://ntp.niehs.nih.gov/go/38143 . FOR FURTHER INFORMATION CONTACT: Abee L... Intakes of Folic Acid,'' is available on the RFI Web site ( http://ntp.niehs.nih.gov/go/38143 ) and should...

  5. Approaches for quantifying energy intake and % calorie restriction (CR) during CR interventions in humans: the multicenter CALERIE study

    USDA-ARS?s Scientific Manuscript database

    Calorie restriction (CR) is a component of most weight-loss interventions and a potential strategy to slow aging. Accurate determination of energy intake and %CR is critical when interpreting the results of CR interventions; this is best achieved using the doubly labeled water method to quantify tot...

  6. Random forests approach for identifying additive and epistatic single nucleotide polymorphisms associated with residual feed intake in dairy cattle

    USDA-ARS?s Scientific Manuscript database

    Feed efficiency is an economically important trait in the beef and dairy cattle industries. Residual feed intake (RFI) is a measure of partial efficiency that is independent of production level per unit of body weight. The objective of this study was to identify significant associations between sing...

  7. Ramjet Intakes

    DTIC Science & Technology

    2010-09-01

    allow intakes to function over large Mach number ranges and at relatively low Reynolds numbers. The NASA Hypersonic Research Engine, the BAC/SUD...Concorde and the Lockheed SR-71 will serve as an introduction to this aspect of intake design. 4.2 NASA Hypersonic research engine The Hypersonic Research...results of the inlet for the nasa hypersonic research engine aerothermodynamic integration model, NASA-TMX-3365; Ramjet Intakes RTO-EN-AVT-185 5

  8. Dietary inulin intake and age can significantly affect intestinal absorption of calcium and magnesium in rats: a stable isotope approach

    PubMed Central

    Coudray, Charles; Rambeau, Mathieu; Feillet-Coudray, Christine; Tressol, Jean Claude; Demigne, Christian; Gueux, Elyett; Mazur, Andrzej; Rayssiguier, Yves

    2005-01-01

    Background previous studies have shown that non-digestible inulin-type fructan intake can increase intestinal mineral absorption in both humans and animals. However, this stimulatory effect on intestinal absorption may depend on experimental conditions such as duration of fermentable fiber intake, mineral diet levels and animals' physiological status, in particular their age. Objectives the aim of this study was to determine the effect of inulin intake on Ca and Mg absorption in rats at different age stages. Methods eighty male Wistar rats of four different ages (2, 5, 10 and 20 months) were randomized into either a control group or a group receiving 3.75% inulin in their diet for 4 days and then 7.5% inulin for three weeks. The animals were fed fresh food and water ad libitum for the duration of the experiment. Intestinal absorption of Ca and Mg was determined by fecal monitoring using stable isotopic tracers. Ca and Mg status was also assessed. Results absorption of Ca and Mg was significantly lower in the aged rats (10 and 20 mo) than in the young and adult rat groups. As expected, inulin intake increased Ca and Mg absorption in all four rat groups. However, inulin had a numerically greater effect on Ca absorption in aged rats than in younger rats whereas its effect on Mg absorption remained similar across all four rat age groups. Conclusion the extent of the stimulatory effect of inulin on absorption of Ca may differ according to animal ages. Further studies are required to explore this effect over longer inulin intake periods, and to confirm these results in humans. PMID:16253138

  9. A high-resolution peak fractionation approach for streamlined screening of nuclear-factor-E2-related factor-2 activators in Salvia miltiorrhiza.

    PubMed

    Zhang, Hui; Luo, Li-Ping; Song, Hui-Peng; Hao, Hai-Ping; Zhou, Ping; Qi, Lian-Wen; Li, Ping; Chen, Jun

    2014-01-24

    Generation of a high-purity fraction library for efficiently screening active compounds from natural products is challenging because of their chemical diversity and complex matrices. In this work, a strategy combining high-resolution peak fractionation (HRPF) with a cell-based assay was proposed for target screening of bioactive constituents from natural products. In this approach, peak fractionation was conducted under chromatographic conditions optimized for high-resolution separation of the natural product extract. The HRPF approach was automatically performed according to the predefinition of certain peaks based on their retention times from a reference chromatographic profile. The corresponding HRPF database was collected with a parallel mass spectrometer to ensure purity and characterize the structures of compounds in the various fractions. Using this approach, a set of 75 peak fractions on the microgram scale was generated from 4mg of the extract of Salvia miltiorrhiza. After screening by an ARE-luciferase reporter gene assay, 20 diterpene quinones were selected and identified, and 16 of these compounds were reported to possess novel Nrf2 activation activity. Compared with conventional fixed-time interval fractionation, the HRPF approach could significantly improve the efficiency of bioactive compound discovery and facilitate the uncovering of minor active components. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. The PREMIER intervention helps participants follow the Dietary Approaches to Stop Hypertension dietary pattern and the current Dietary Reference Intakes recommendations.

    PubMed

    Lin, Pao-Hwa; Appel, Lawrence J; Funk, Kristine; Craddick, Shirley; Chen, Chuhe; Elmer, Patricia; McBurnie, Mary Ann; Champagne, Catherine

    2007-09-01

    To examine the influence of the PREMIER study lifestyle interventions on dietary intakes and adherence to the Dietary Approaches to Stop Hypertension (DASH) dietary pattern and the Dietary Reference Intakes (DRI). An 18-month multicenter, randomized controlled trial comparing two multicomponent lifestyle intervention programs to an advice only control group. A total of 810 participants were recruited from local communities and randomized into the study. Individuals were eligible if they were aged 25 years or older, had body mass index between 18.5 and 45.0, not taking antihypertensive medication, and had prehypertension or stage 1 hypertension (systolic blood pressure 120 to 159 mm Hg and diastolic blood pressure 80 to 95 mm Hg). The two active intervention programs were a behavioral lifestyle intervention that implements established recommendations, and an established intervention plus the DASH dietary pattern. Both interventions consisted of intensive group and individual counseling sessions. The control group received a brief advice session after randomization and again after 6 months of data collection. Dietary intakes were collected by two random 24-hour recalls at baseline, 6 months, and 18 months. The primary outcome of the PREMIER study was change in systolic blood pressure at 6 months. The main outcomes examined here include dietary variables collected by 24-hour recall at each time point. Nutrient intakes were calculated and compared among the time points and the three intervention groups using mixed models with repeated measures at 6 and 18 months. Proportion of participants who met or achieved the original DASH nutrient intake levels and the DRIs were calculated and compared among the three intervention groups. P<0.01 was considered statistically significant. Participants in both the established intervention and established intervention plus DASH dietary pattern groups substantially reduced energy, total fat, saturated fat, and sodium intake and these

  11. A quantitative look at fluorosis, fluoride exposure, and intake in children using a health risk assessment approach.

    PubMed

    Erdal, Serap; Buchanan, Susan N

    2005-01-01

    The prevalence of dental fluorosis in the United States has increased during the last 30 years. In this study, we used a mathematical model commonly employed by the U.S. Environmental Protection Agency to estimate average daily intake of fluoride via all applicable exposure pathways contributing to fluorosis risk for infants and children living in hypothetical fluoridated and nonfluoridated communities. We also estimated hazard quotients for each exposure pathway and hazard indices for exposure conditions representative of central tendency exposure (CTE) and reasonable maximum exposure (RME) conditions. The exposure pathways considered were uptake of fluoride via fluoridated drinking water, beverages, cow's milk, foods, and fluoride supplements for both age groups. Additionally, consumption of infant formula for infants and inadvertent swallowing of toothpaste while brushing and incidental ingestion of soil for children were also considered. The cumulative daily fluoride intake in fluoridated areas was estimated as 0.20 and 0.11 mg/kg-day for RME and CTE scenarios, respectively, for infants. On the other hand, the RME and CTE estimates for children were 0.23 and 0.06 mg/kg-day, respectively. In areas where municipal water is not fluoridated, our RME and CTE estimates for cumulative daily average intake were, respectively, 0.11 and 0.08 mg/kg-day for infants and 0.21 and 0.06 mg/kg-day for children. Our theoretical estimates are in good agreement with measurement-based estimates reported in the literature. Although CTE estimates were within the optimum range for dental caries prevention, the RME estimates were above the upper tolerable intake limit. This suggests that some children may be at risk for fluorosis.

  12. Area-based cell colony surviving fraction evaluation: A novel fully automatic approach using general-purpose acquisition hardware.

    PubMed

    Militello, Carmelo; Rundo, Leonardo; Conti, Vincenzo; Minafra, Luigi; Cammarata, Francesco Paolo; Mauri, Giancarlo; Gilardi, Maria Carla; Porcino, Nunziatina

    2017-09-05

    The current methodology for the Surviving Fraction (SF) measurement in clonogenic assay, which is a technique to study the anti-proliferative effect of treatments on cell cultures, involves manual counting of cell colony forming units. This procedure is operator-dependent and error-prone. Moreover, the identification of the exact colony number is often not feasible due to the high growth rate leading to the adjacent colony merging. As a matter of fact, conventional assessment does not deal with the colony size, which is generally correlated with the delivered radiation dose or the administered cytotoxic agent. Considering that the Area Covered by Colony (ACC) is proportional to the colony number and size as well as to the growth rate, we propose a novel fully automatic approach exploiting Circle Hough Transform, to automatically detect the wells in the plate, and local adaptive thresholding, which calculates the percentage of ACC for the SF quantification. This measurement relies just on this covering percentage and does not consider the colony number, preventing inconsistencies due to intra- and inter-operator variability. To evaluate the accuracy of the proposed approach, we compared the SFs obtained by our automatic ACC-based method against the conventional counting procedure. The achieved results (r = 0.9791 and r = 0.9682 on MCF7 and MCF10A cells, respectively) showed values highly correlated with the measurements using the traditional approach based on colony number alone. The proposed computer-assisted methodology could be integrated in laboratory practice as an expert system for the SF evaluation in clonogenic assays. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. A hydrodynamics-based approach to evaluating the risk of waterborne pathogens entering drinking water intakes in a large, stratified lake.

    PubMed

    Hoyer, Andrea B; Schladow, S Geoffrey; Rueda, Francisco J

    2015-10-15

    Pathogen contamination of drinking water lakes and reservoirs is a severe threat to human health worldwide. A major source of pathogens in surface sources of drinking waters is from body-contact recreation in the water body. However, dispersion pathways of human waterborne pathogens from recreational beaches, where body-contact recreation is known to occur to drinking water intakes, and the associated risk of pathogens entering the drinking water supply remain largely undocumented. A high spatial resolution, three-dimensional hydrodynamic and particle tracking modeling approach has been developed to analyze the risk and mechanisms presented by pathogen dispersion. The pathogen model represents the processes of particle release, transport and survival. Here survival is a function of both water temperature and cumulative exposure to ultraviolet (UV) radiation. Pathogen transport is simulated using a novel and computationally efficient technique of tracking particle trajectories backwards, from a drinking water intake toward their source areas. The model has been applied to a large, alpine lake - Lake Tahoe, CA-NV (USA). The dispersion model results reveal that for this particular lake (1) the risk of human waterborne pathogens to enter drinking water intakes is low, but significant; (2) this risk is strongly related to the depth of the thermocline in relation to the depth of the intake; (3) the risk increases with the seasonal deepening of the surface mixed layer; and (4) the risk increases at night when the surface mixed layer deepens through convective mixing and inactivation by UV radiation is eliminated. While these risk factors will quantitatively vary in different lakes, these same mechanisms will govern the process of transport of pathogens.

  14. Importance of calcium co-medication in bisphosphonate therapy of osteoporosis: an approach to improving correct intake and drug adherence.

    PubMed

    Ringe, Johann D; van der Geest, Stefan A P; Möller, Gerd

    2006-01-01

    In all of the large, pivotal, multicentre trials of bisphosphonate therapy, patients have received added calcium in amounts ranging from 500 to 1000 mg/day above individual dietary intake. Accordingly, calcium supplements or calcium/vitamin D combinations are currently recommended as co-medication with anti-resorptive therapy in all recently published guidelines on the treatment of osteoporosis. However, the consistent use or effectiveness of calcium may be impaired by several factors in the individual patient, including low prescription rate or lack of advice to purchase calcium, reduced adherence because of the complexity of the regimen, and incorrect intake (e.g. taking calcium with bisphosphonates at the same time). Patients with osteoporosis who adhere to drug therapy experience a significantly lower fracture rate. Therefore, there is a need to improve correct intake of bisphosphonates together with calcium supplementation, which may enhance adherence. The dosage regimen could be simplified by providing the two compounds in an integrated pack. Such a pack, containing one tablet of risedronic acid and six calcium carbonate tablets (Actonel), Procter & Gamble Pharmaceuticals, Weiterstadt, Germany), has been developed to facilitate correct intake. In this study, the impact of this fixed-combination pack on patient understanding of dosing instructions and on preference was tested by comparing the fixed combination with separate risedronic acid and calcium packages. A new blister strip was developed containing one tablet of risedronic acid 35mg and six tablets of calcium carbonate 1250mg (500mg elemental calcium), representing 1 week of therapy; the control was the same medications in separate packaging. The study was conducted in a cohort of 164 postmenopausal women (mean age 69 years). Half of the participants were bisphosphonate users (n = 83). The combined understanding of five instructions - risedronic acid intake in the morning, only with water, without food

  15. An intuitive approach to understanding the attributable fraction of disease due to a risk factor: the case of smoking.

    PubMed

    Rosen, Laura

    2013-07-16

    The health damage from tobacco use has been studied intensively, yet quantifying the precise burden of disease and death due to smoking is a complex problem, and consequently open to manipulation by interested parties. The goals of this paper are to clearly communicate the concept of the attributable fraction (AF), i.e., the proportion of disease in a population which can be attributed to a risk factor, and to understand the relationship between the AF, the prevalence of exposure in a population, and the relative risk of disease given the exposure. The current approach to calculating the AF is summarized. An intuitive formula is proposed, with accompanying graphical illumination. For diseases caused by smoking, the AF of disease due to smoking increases with the prevalence of smoking and with the relative risk of disease due to smoking. The proposed method has the potential to help health professionals and decision makers understand the concept of the burden of disease due to smoking or other lifestyle, environmental, and occupational factors, in the context of public health importance. This will aid sound decision-making in public health policy.

  16. Hydrodynamic radius determination with asymmetrical flow field-flow fractionation using decaying cross-flows. Part I. A theoretical approach.

    PubMed

    Håkansson, Andreas; Magnusson, Emma; Bergenståhl, Björn; Nilsson, Lars

    2012-08-31

    Direct determination of hydrodynamic radius from retention time is an advantage of the field-flow fractionation techniques. However, this is not always completely straight forward since non-idealities exist and assumptions have been made in deriving the retention equations. In this study we investigate the effect on accuracy from two factors: (1) level of sophistication of the equations used to determine channel height from a calibration experiment and (2) the influence of secondary relaxation on the accuracy of hydrodynamic radius determination. A new improved technique for estimating the channel height from calibration experiments is suggested. It is concluded that severe systematic error can arise if the most common channel height equations are used and an alternative more rigorous approach is described. For secondary relaxation it is concluded that this effect increases with the cross-flow decay rate. The secondary relaxation effect is quantified for different conditions. This is part one of two. In the second part the determination of hydrodynamic radius are evaluated experimentally under similar conditions.

  17. Wave simulation in 2D heterogeneous transversely isotropic porous media with fractional attenuation: A Cartesian grid approach

    NASA Astrophysics Data System (ADS)

    Blanc, Emilie; Chiavassa, Guillaume; Lombard, Bruno

    2014-10-01

    A time-domain numerical modeling of transversely isotropic Biot poroelastic waves is proposed in two dimensions. The viscous dissipation occurring in the pores is described using the dynamic permeability model developed by Johnson-Koplik-Dashen (JKD). Some of the coefficients in the Biot-JKD model are proportional to the square root of the frequency. In the time-domain, these coefficients introduce shifted fractional derivatives of order 1/2, involving a convolution product. Based on a diffusive representation, the convolution kernel is replaced by a finite number of memory variables that satisfy local-in-time ordinary differential equations, resulting in the Biot-DA (diffusive approximation) model. The properties of both the Biot-JKD and the Biot-DA models are analyzed: hyperbolicity, decrease of energy, dispersion. To determine the coefficients of the diffusive approximation, two approaches are analyzed: Gaussian quadratures and optimization methods in the frequency range of interest. The nonlinear optimization is shown to be the better way of determination. A splitting strategy is then applied to approximate numerically the Biot-DA equations. The propagative part is discretized using a fourth-order ADER scheme on a Cartesian grid, whereas the diffusive part is solved exactly. An immersed interface method is implemented to take into account heterogeneous media on a Cartesian grid and to discretize the jump conditions at interfaces. Numerical experiments are presented. Comparisons with analytical solutions show the efficiency and the accuracy of the approach, and some numerical experiments are performed to investigate wave phenomena in complex media, such as multiple scattering across a set of random scatterers.

  18. Analysis of the Oryza sativa plasma membrane proteome using combined protein and peptide fractionation approaches in conjunction with mass spectrometry.

    PubMed

    Natera, Siria H A; Ford, Kristina L; Cassin, Andrew M; Patterson, John H; Newbigin, Edward J; Bacic, Antony

    2008-03-01

    To identify integral and peripheral plasma membrane (PM) proteins from Oryza sativa (rice), highly enriched PM fractions from rice suspension cultured cells were analyzed using two complementary approaches. The PM was enriched using aqueous two-phase partitioning and high pH carbonate washing to remove soluble, contaminating proteins and characterized using enzymatic and immunological analyses. Proteins from the carbonate-washed PM (WPM) were analyzed by either one-dimensional gel electrophoresis (1D-SDS-PAGE) followed by tryptic proteolysis or proteolysis followed by strong cation exchange liquid chromatography (LC) with subsequent analysis of the tryptic peptides by LC-MS/MS (termed Gel-LC-MS/MS and 2D-LC-MS/MS, respectively). Combining the results of these two approaches, 438 proteins were identified on the basis of two or more matching peptides, and a further 367 proteins were identified on the basis of single peptide matches after data analysis with two independent search algorithms. Of these 805 proteins, 350 were predicted to be PM or PM-associated proteins. Four hundred and twenty-five proteins (53%) were predicted to be integrally associated with a membrane, via either one or many (up to 16) transmembrane domains, a GPI-anchor, or membrane-spanning beta-barrels. Approximately 80% of the 805 identified proteins were assigned a predicted function, based on similarity to proteins of known function or the presence of functional domains. Proteins involved in PM-related activities such as signaling (21% of the 805 proteins), transporters and ATPases (14%), and cellular trafficking (8%), such as via vesicles involved in endo- and exocytosis, were identified. Proteins that are involved in cell wall biosynthesis were also identified (5%) and included three cellulose synthase (CESA) proteins, a cellulose synthase-like D (CSLD) protein, cellulases, and several callose synthases. Approximately 20% of the proteins identified in this study remained functionally

  19. Random Forests approach for identifying additive and epistatic single nucleotide polymorphisms associated with residual feed intake in dairy cattle.

    PubMed

    Yao, C; Spurlock, D M; Armentano, L E; Page, C D; VandeHaar, M J; Bickhart, D M; Weigel, K A

    2013-10-01

    Feed efficiency is an economically important trait in the beef and dairy cattle industries. Residual feed intake (RFI) is a measure of partial efficiency that is independent of production level per unit of body weight. The objective of this study was to identify significant associations between single nucleotide polymorphism (SNP) markers and RFI in dairy cattle using the Random Forests (RF) algorithm. Genomic data included 42,275 SNP genotypes for 395 Holstein cows, whereas phenotypic measurements were daily RFI from 50 to 150 d postpartum. Residual feed intake was defined as the difference between an animal's feed intake and the average intake of its cohort, after adjustment for year and season of calving, year and season of measurement, age at calving nested within parity, days in milk, milk yield, body weight, and body weight change. Random Forests is a widely used machine-learning algorithm that has been applied to classification and regression problems. By analyzing the tree structures produced within RF, the 25 most frequent pairwise SNP interactions were reported as possible epistatic interactions. The importance scores that are generated by RF take into account both main effects of variables and interactions between variables, and the most negative value of all importance scores can be used as the cutoff level for declaring SNP effects as significant. Ranking by importance scores, 188 SNP surpassed the threshold, among which 38 SNP were mapped to RFI quantitative trait loci (QTL) regions reported in a previous study in beef cattle, and 2 SNP were also detected by a genome-wide association study in beef cattle. The ratio of number of SNP located in RFI QTL to the total number of SNP in the top 188 SNP chosen by RF was significantly higher than in all 42,275 whole-genome markers. Pathway analysis indicated that many of the top 188 SNP are in genomic regions that contain annotated genes with biological functions that may influence RFI. Frequently occurring

  20. A food-based approach introducing orange-fleshed sweet potatoes increased vitamin A intake and serum retinol concentrations in young children in rural Mozambique.

    PubMed

    Low, Jan W; Arimond, Mary; Osman, Nadia; Cunguara, Benedito; Zano, Filipe; Tschirley, David

    2007-05-01

    Vitamin A deficiency is widespread and has severe consequences for young children in the developing world. Food-based approaches may be an appropriate and sustainable complement to supplementation programs. Orange-fleshed sweet potato (OFSP) is rich in beta-carotene and is well accepted by young children. In an extremely resource poor area in Mozambique, the effectiveness of introduction of OFSP was assessed in an integrated agriculture and nutrition intervention, which aimed to increase vitamin A intake and serum retinol concentrations in young children. The 2-y quasi-experimental intervention study followed households and children (n = 741; mean age 13 mo at baseline) through 2 agricultural cycles. In y 2, 90% of intervention households produced OFSP, and mean OFSP plot size in intervention areas increased from 33 to 359 m(2). Intervention children (n = 498) were more likely than control children (n = 243) to eat OFSP 3 or more d in the last wk (55% vs. 8%, P < 0.001) and their vitamin A intakes were much higher than those of control children (median 426 vs. 56 microg retinol activity equivalent, P < 0.001). Controlling for infection/inflammation and other confounders, mean serum retinol increased by 0.100 micromol/L (SEM 0.024; P < 0.001) in intervention children and did not increase significantly in control subjects. Integrated promotion of OFSP can complement other approaches and contribute to increases in vitamin A intake and serum retinol concentrations in young children in rural Mozambique and similar areas in Sub-Saharan Africa.

  1. Development of toxicity criteria for petroleum hydrocarbon fractions in the Petroleum Hydrocarbon Criteria Working Group approach for risk-based management of total petroleum hydrocarbons in soil.

    PubMed

    Twerdok, L E

    1999-02-01

    The Total Petroleum Hydrocarbon Criteria Working Croup (TPHCWG) was formed in 1993 based on the observation that widely different clean-up requirements were being used by states at sites that were contaminated with hydrocarbon materials such as fuels, lubricating oils, and crude oils. These requirements were usually presented as concentration of total petroleum hydrocarbon (TPH), and ranged from 10 to over 10,000 mg TPH/kg soil. Members of this multi-disciplinary group, consisting of representatives from industry, government and academia, jointly recognized that the numerical standard was not based on a scientific assessment of human health risk and established the following goal for the effort: To develop scientifically defensible information for establishing soil cleanup levels that are protective of human health at hydrocarbon contaminated sites. The approach developed by the TPHCWG for TPH hazard assessment consisted of dividing the petroleum hydrocarbon material into multichemical-containing fractions with similar fate and transport characteristics. These fractions were then assigned fate and transport properties (volatilization factor, soil leaching factor, etc.) and toxicity values (RfDs/RfCs) representative of the fraction. The actual site specific hazard assessment and derivation of cleanup levels is accomplished by analyzing sites to determine which fraction(s) is present and applying the appropriate fate, transport and toxicity factors. The method used by this group to determine TPH Faction specific toxicity criteria is a surrogate approach intended to supplement the indicator approach. Indicators are single, carcinogenic hydrocarbon compounds which are evaluated/regulated individually at either the federal or state level. The TPHCWG surrogate approach utilized all appropriate fraction specific toxicity data (single compound and mixture/product), minus the carcinogenic indicator compounds, to derive the fraction specific RfDs and RfCs. This hazard

  2. Comparison of different segmentation approaches without using gold standard. Application to the estimation of the left ventricle ejection fraction from cardiac cine MRI sequences

    PubMed Central

    Lebenberg, Jessica; Buvat, Irène; Garreau, Mireille; Casta, Christopher; Constantinidès, Constantin; Cousty, Jean; Cochet, Alexandre; Jehan-Besson, Stéphanie; Tilmant, Christophe; Lefort, Muriel; Roullot, Elodie; Najman, Laurent; Sarry, Laurent; Clarysse, Patrick; De Cesare, Alain; Lalande, Alain; Frouin, Frédérique

    2011-01-01

    A statistical method is proposed to compare several estimates of a relevant clinical parameter when no gold standard is available. The method is illustrated by considering the left ventricle ejection fraction derived from cardiac magnetic resonance images and computed using seven approaches with different degrees of automation. The proposed method did not use any a priori regarding with the reliability of each method and its degree of automation. The results showed that the most accurate estimates of the ejection fraction were obtained using manual segmentations, followed by the semi-automatic methods, while the methods with the least user input yielded the least accurate ejection fraction estimates. These results were consistent with the expected performance of the estimation methods, suggesting that the proposed statistical approach might be helpful to assess the performance of estimation methods on clinical data for which no gold standard is available. PMID:22254889

  3. Iron isotope fractionation between aqueous Fe(II) and goethite revisited: New insights based on a multi-direction approach to equilibrium and isotopic exchange rate modification

    NASA Astrophysics Data System (ADS)

    Frierdich, Andrew J.; Beard, Brian L.; Reddy, Thiruchelvi R.; Scherer, Michelle M.; Johnson, Clark M.

    2014-08-01

    The Fe isotope compositions of naturally occurring Fe oxide minerals provide insights into biogeochemical processes that occur in modern and ancient environments. Key to understanding isotopic variations in such minerals is knowledge of the equilibrium Fe isotope fractionation factors between common minerals and aqueous Fe species. Because experimental measurements of isotopic fractionation may reflect a combination of kinetic and equilibrium fractionations during rapid dissolution and precipitation, even in experiments that employ the three-isotope method, assessment of the attainment of equilibrium is often difficult. Here, we re-examine Fe isotope exchange, via a 57Fe tracer, and natural mass-dependent fractionation, through changes in initial 56Fe/54Fe ratios, between aqueous Fe(II) (Fe(II)aq) and goethite. This approach uses the three-isotope method, but is distinct in its evaluation of kinetic isotope fractionation and the attainment of equilibrium by: (i) employing a multi-direction approach to equilibrium at 22 °C via reaction of three Fe(II)aq solutions that had different initial 56Fe/54Fe ratios, (ii) conducting isotopic exchange experiments at elevated temperature (50 °C), and (iii) modifying the rate of isotopic exchange through a combination of trace-element substitutions and particle coarsening to evaluate corresponding temporal changes in fractionation trajectories that may reflect changing instantaneous fractionation factors. We find that rapid isotopic exchange produces kinetic isotope effects between Fe(II)aq and goethite, which shifts the 56Fe/54Fe ratios of Fe(II)aq early in reactions toward that of goethite, indicating that the instantaneous Fe(II)aq-goethite fractionation factor under kinetic conditions is small. Importantly, however, this kinetic fractionation is “erased” with continued reaction, and this is evident by the congruence for multiple-exchange trajectories of distinct initial Fe(II)aq solutions toward the same final value

  4. The Local Food Environment and Fruit and Vegetable Intake: A Geographically Weighted Regression Approach in the ORiEL Study.

    PubMed

    Clary, Christelle; Lewis, Daniel J; Flint, Ellen; Smith, Neil R; Kestens, Yan; Cummins, Steven

    2016-12-01

    Studies that explore associations between the local food environment and diet routinely use global regression models, which assume that relationships are invariant across space, yet such stationarity assumptions have been little tested. We used global and geographically weighted regression models to explore associations between the residential food environment and fruit and vegetable intake. Analyses were performed in 4 boroughs of London, United Kingdom, using data collected between April 2012 and July 2012 from 969 adults in the Olympic Regeneration in East London Study. Exposures were assessed both as absolute densities of healthy and unhealthy outlets, taken separately, and as a relative measure (proportion of total outlets classified as healthy). Overall, local models performed better than global models (lower Akaike information criterion). Locally estimated coefficients varied across space, regardless of the type of exposure measure, although changes of sign were observed only when absolute measures were used. Despite findings from global models showing significant associations between the relative measure and fruit and vegetable intake (β = 0.022; P < 0.01) only, geographically weighted regression models using absolute measures outperformed models using relative measures. This study suggests that greater attention should be given to nonstationary relationships between the food environment and diet. It further challenges the idea that a single measure of exposure, whether relative or absolute, can reflect the many ways the food environment may shape health behaviors. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Randomization to plant-based dietary approaches leads to larger short-term improvements in Dietary Inflammatory Index scores and macronutrient intake compared with diets that contain meat.

    PubMed

    Turner-McGrievy, Gabrielle M; Wirth, Michael D; Shivappa, Nitin; Wingard, Ellen E; Fayad, Raja; Wilcox, Sara; Frongillo, Edward A; Hébert, James R

    2015-02-01

    Studies have examined nutrient differences among people following different plant-based diets. However, all of these studies have been observational. The aim of the present study was to examine differences in nutrient intake and Dietary Inflammatory Index (DII) scores among overweight and obese (body mass index 25.0-49.9 kg/m(2)) adults randomized to receive dietary instruction on a vegan (n = 12), vegetarian (n = 13), pescovegetarian (n = 13), semivegetarian (n = 13), or omnivorous (n = 12) diet during a 6-month randomized controlled trial. Nutrient intake, nutrient adequacy, and DII score were assessed via two 24-hour dietary recalls (Automated Self-Administered 24-Hour Dietary Recall) at baseline and at 2 and 6 months. Differences in nutrient intake and the DII were examined using general linear models with follow-up tests at each time point. We hypothesized that individuals randomized to the vegan diet would have lower DII scores and greater improvements in fiber, carbohydrate, fat, saturated fat, and cholesterol at both 2 and 6 months as compared with the other 4 diets. Participants randomized to the vegan diet had significantly greater changes in most macronutrients at both time points, including fat and saturated fat, as well as cholesterol and, at 2 months, fiber, as compared with most of the other diet groups (Ps < .05). Vegan, vegetarian, and pescovegetarian participants all saw significant improvements in the DII score as compared with semivegetarian participants at 2 months (Ps < .05) with no differences at 6 months. Given the greater impact on macronutrients and the DII during the short term, finding ways to provide support for adoption and maintenance of plant-based dietary approaches, such as vegan and vegetarian diets, should be given consideration. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. A Multiphysics Modeling Approach to Develop Right Ventricle Pulmonary Valve Replacement Surgical Procedures with a Contracting Band to Improve Ventricle Ejection Fraction

    PubMed Central

    Tang, Dalin; Yang, Chun; Geva, Tal; Rathod, Rahul; Yamauchi, Haruo; Gooty, Vasu; Tang, Alexander; Kural, Mehmet H.; Billiar, Kristen L.; Gaudette, Glenn; del Nido, Pedro J.

    2012-01-01

    Patients with repaired tetralogy of Fallot account for the majority of cases with late onset right ventricle (RV) failure. A new surgical procedure placing an elastic band in the right ventricle is proposed to improve RV function measured by ejection fraction. A multiphysics modeling approach is developed to combine cardiac magnetic resonance imaging, modeling, tissue engineering and mechanical testing to demonstrate feasibility of the new surgical procedure. Our modeling results indicated that the new surgical procedure has the potential to improve right ventricle ejection fraction by 2–7% which compared favorably with recently published drug trials to treat LV heart failure. PMID:23667272

  7. Assessment of exposure to PCB 153 from breast feeding and normal food intake in individual children using a system approach model

    PubMed Central

    Trnovec, Tomáš; Dedík, Ladislav; Jusko, Todd A.; Lancz, Kinga; Palkovičová, Ľubica; Kočan, Anton; Šovčíková, Eva; Wimmerová, Soňa; Tihányi, Juraj; Patayová, Henrieta; Hertz-Picciotto, Irva

    2011-01-01

    Investigators have typically relied on a single or few discrete time points as measures of polychlorinated biphenyl (PCB) body burden, however health effects are more likely to be the result of integrative exposure in time, optionally expressed as an area under the time curve (AUC) of PCB serum concentration. Using data from a subgroup of 93 infants from a birth cohort in eastern Slovakia—a region highly polluted by PCBs—we fit a system type model, customized to our longitudinal measures of serum PCB concentrations in cord, 6, 16, and, 45 month blood specimens. The most abundant congener, PCB 153, was chosen for modeling purposes. In addition to currently used methods of exposure assessment, our approach estimates a concentration time profile for each subject, taking into account mean residence time of PCB 153 molecules in the body, duration of breast feeding, hypothetical PCB 153 concentration in steady-state without breast feeding and alternately without normal food intake. Hypothetical PCB 153 concentration in steady-state without normal food intake correlates with AUC (r=0.84, p<0.001) as well as with duration of breast feeding (r=0.64, p<0.001). It makes possible to determine each subject’s exposure profile expressed as AUC of PCBs serum concentration with a minimum model parameters. PCB body burden in most infants was strongly associated with duration of breast feeding in most, but not all children, was apparent from model output. PMID:22051344

  8. Using a mixed-methods approach to measure impact of a school-based nutrition and media education intervention study on fruit and vegetable intake of Italian children.

    PubMed

    Grassi, Elena; Evans, Alexandra; Ranjit, Nalini; Pria, Simona Dalla; Messina, Laura

    2016-08-01

    The purpose of the present study was to investigate the impact of a school-based nutrition and media education intervention on the promotion of fruit and vegetable consumption to help prevent childhood obesity. The 10-week-long intervention included sessions on nutrition education and media literacy. It also included a health communication media-based campaign workshop during which the children created posters, newsletters and video commercials related to fruits and vegetables targeted to their parents. For evaluation purposes, the study utilized a mixed-methods approach, including a quasi-experimental study (with one intervention group and one control group) and a focus group study. Four different elementary schools in Treviso (Veneto Region of Italy) agreed to participate in the research. The target population for the study included 10-year-old Italian children and their parents. Data indicate that this intervention was effective for children but not for parents. Evaluation results show that the intervention was effective in significantly increasing children's fruit and vegetable intake (P<0·05) and all psychosocial determinants (P<0·05). The study results confirm the efficacy of a school-based health and media education intervention to address the children's obesity issue and, in particular, to increase children's fruit and vegetable intake. The study also opens a new perspective on the theoretical constructs investigated, because the development of 'ability of expression' could be considered one of the most important factors to determine the efficacy of the intervention.

  9. Fractional vector calculus and fractional Maxwell's equations

    SciTech Connect

    Tarasov, Vasily E.

    2008-11-15

    The theory of derivatives and integrals of non-integer order goes back to Leibniz, Liouville, Grunwald, Letnikov and Riemann. The history of fractional vector calculus (FVC) has only 10 years. The main approaches to formulate a FVC, which are used in the physics during the past few years, will be briefly described in this paper. We solve some problems of consistent formulations of FVC by using a fractional generalization of the Fundamental Theorem of Calculus. We define the differential and integral vector operations. The fractional Green's, Stokes' and Gauss's theorems are formulated. The proofs of these theorems are realized for simplest regions. A fractional generalization of exterior differential calculus of differential forms is discussed. Fractional nonlocal Maxwell's equations and the corresponding fractional wave equations are considered.

  10. Analyzing signal attenuation in PFG anomalous diffusion via a non-Gaussian phase distribution approximation approach by fractional derivatives.

    PubMed

    Lin, Guoxing

    2016-11-21

    Anomalous diffusion exists widely in polymer and biological systems. Pulsed-field gradient (PFG) techniques have been increasingly used to study anomalous diffusion in nuclear magnetic resonance and magnetic resonance imaging. However, the interpretation of PFG anomalous diffusion is complicated. Moreover, the exact signal attenuation expression including the finite gradient pulse width effect has not been obtained based on fractional derivatives for PFG anomalous diffusion. In this paper, a new method, a Mainardi-Luchko-Pagnini (MLP) phase distribution approximation, is proposed to describe PFG fractional diffusion. MLP phase distribution is a non-Gaussian phase distribution. From the fractional derivative model, both the probability density function (PDF) of a spin in real space and the PDF of the spin's accumulating phase shift in virtual phase space are MLP distributions. The MLP phase distribution leads to a Mittag-Leffler function based PFG signal attenuation, which differs significantly from the exponential attenuation for normal diffusion and from the stretched exponential attenuation for fractional diffusion based on the fractal derivative model. A complete signal attenuation expression Eα(-Dfbα,β(*)) including the finite gradient pulse width effect was obtained and it can handle all three types of PFG fractional diffusions. The result was also extended in a straightforward way to give a signal attenuation expression of fractional diffusion in PFG intramolecular multiple quantum coherence experiments, which has an n(β) dependence upon the order of coherence which is different from the familiar n(2) dependence in normal diffusion. The results obtained in this study are in agreement with the results from the literature. The results in this paper provide a set of new, convenient approximation formalisms to interpret complex PFG fractional diffusion experiments.

  11. Analyzing signal attenuation in PFG anomalous diffusion via a non-Gaussian phase distribution approximation approach by fractional derivatives

    NASA Astrophysics Data System (ADS)

    Lin, Guoxing

    2016-11-01

    Anomalous diffusion exists widely in polymer and biological systems. Pulsed-field gradient (PFG) techniques have been increasingly used to study anomalous diffusion in nuclear magnetic resonance and magnetic resonance imaging. However, the interpretation of PFG anomalous diffusion is complicated. Moreover, the exact signal attenuation expression including the finite gradient pulse width effect has not been obtained based on fractional derivatives for PFG anomalous diffusion. In this paper, a new method, a Mainardi-Luchko-Pagnini (MLP) phase distribution approximation, is proposed to describe PFG fractional diffusion. MLP phase distribution is a non-Gaussian phase distribution. From the fractional derivative model, both the probability density function (PDF) of a spin in real space and the PDF of the spin's accumulating phase shift in virtual phase space are MLP distributions. The MLP phase distribution leads to a Mittag-Leffler function based PFG signal attenuation, which differs significantly from the exponential attenuation for normal diffusion and from the stretched exponential attenuation for fractional diffusion based on the fractal derivative model. A complete signal attenuation expression Eα(-Dfbα,β * ) including the finite gradient pulse width effect was obtained and it can handle all three types of PFG fractional diffusions. The result was also extended in a straightforward way to give a signal attenuation expression of fractional diffusion in PFG intramolecular multiple quantum coherence experiments, which has an nβ dependence upon the order of coherence which is different from the familiar n2 dependence in normal diffusion. The results obtained in this study are in agreement with the results from the literature. The results in this paper provide a set of new, convenient approximation formalisms to interpret complex PFG fractional diffusion experiments.

  12. Exploiting Fractional Order PID Controller Methods in Improving the Performance of Integer Order PID Controllers: A GA Based Approach

    NASA Astrophysics Data System (ADS)

    Mukherjee, Bijoy K.; Metia, Santanu

    2009-10-01

    The paper is divided into three parts. The first part gives a brief introduction to the overall paper, to fractional order PID (PIλDμ) controllers and to Genetic Algorithm (GA). In the second part, first it has been studied how the performance of an integer order PID controller deteriorates when implemented with lossy capacitors in its analog realization. Thereafter it has been shown that the lossy capacitors can be effectively modeled by fractional order terms. Then, a novel GA based method has been proposed to tune the controller parameters such that the original performance is retained even though realized with the same lossy capacitors. Simulation results have been presented to validate the usefulness of the method. Some Ziegler-Nichols type tuning rules for design of fractional order PID controllers have been proposed in the literature [11]. In the third part, a novel GA based method has been proposed which shows how equivalent integer order PID controllers can be obtained which will give performance level similar to those of the fractional order PID controllers thereby removing the complexity involved in the implementation of the latter. It has been shown with extensive simulation results that the equivalent integer order PID controllers more or less retain the robustness and iso-damping properties of the original fractional order PID controllers. Simulation results also show that the equivalent integer order PID controllers are more robust than the normal Ziegler-Nichols tuned PID controllers.

  13. Comparison of two experimental speciation methods with a theoretical approach to monitor free and labile Cd fractions in soil solutions.

    PubMed

    Parat, C; Cornu, J-Y; Schneider, A; Authier, L; Sapin-Didier, V; Denaix, L; Potin-Gautier, M

    2009-08-26

    This work focused on the suitability of two techniques to monitor cadmium speciation in soil solutions collected during a 7-day incubation of a contaminated soil. Anodic stripping voltammetry (ASV) and ion exchange were performed on soil solutions collected daily and results were compared with calculations obtained with the speciation software Visual MINTEQ. The electrochemically labile Cd fraction was greater than the exchange-estimated free Cd fraction during the first 6 days, after which it decreased sharply during the last 2 days to reach values close to the exchange-estimated free Cd fraction. Further investigations showed that the increase in pH was mainly responsible for the reduction. However, calculations performed with Visual MINTEQ software clearly demonstrated that a change in the nature of organic matter and/or its complexing capacity also needed to be taken into consideration.

  14. A new simple, low-cost approach for generation of the PM10 fraction from soil and related materials: application to human health risk assessment.

    PubMed

    Boisa, Ndokiari; Entwistle, Jane; Dean, John R

    2014-12-10

    A new simple, robust and low-cost wet laboratory method for the generation of the <10 μm (PM10) particle size fraction is reported. A sedimentation method is directly compared with a centrifugation method for generation of the PM10 fraction. Both approaches are based on an integrated form of Stokes' law. Subsequently the sedimentation method was adopted. The results from the sedimentation method were corroborated using particle size distribution measurements. This approach for the generation of the PM10 fraction was applied to soil and mine waste samples from Mitrovica, Kosovo as part of an investigation in to the human risk assessment from inhalation of the PM10 fraction containing potentially harmful elements (PHEs). The average daily dose for Cd from the inhalation of suspended soil particles was calculated to be 0.021 and 0.010 μg kg(-1) BW d(-1) for a child and an adult, respectively. This corresponded to an inhalation dose of 0.50 and 0.70 μg Cdd(-1) for a child (20 kg) and an adult (70 kg), respectively.

  15. Daily self-monitoring of body weight, step count, fruit/vegetable intake, and water consumption: a feasible and effective long-term weight loss maintenance approach.

    PubMed

    Akers, Jeremy D; Cornett, Rachel A; Savla, Jyoti S; Davy, Kevin P; Davy, Brenda M

    2012-05-01

    Maintenance of weight loss remains a challenge for most individuals. Thus, practical and effective weight-loss maintenance (WTLM) strategies are needed. A two-group 12-month WTLM intervention trial was conducted from June 2007 to February 2010 to determine the feasibility and effectiveness of a WTLM intervention for older adults using daily self-monitoring of body weight, step count, fruit/vegetable (F/V) intake, and water consumption. Forty weight-reduced individuals (mean weight lost=6.7±0.6 kg; body mass index [calculated as kg/m²] 29.2±1.1), age 63±1 years, who had previously participated in a 12-week randomized controlled weight-loss intervention trial, were instructed to record daily body weight, step count, and F/V intake (WEV [defined as weight, exercise, and F/V]). Experimental group (WEV+) participants were also instructed to consume 16 fl oz of water before each main meal (ie, three times daily), and to record daily water intake. Outcome measures included weight change, diet/physical activity behaviors, theoretical constructs related to health behaviors, and other clinical measures. Statistical analyses included growth curve analyses and repeated measures analysis of variance. Over 12 months, there was a linear decrease in weight (β=-0.32, P<0.001) and a quadratic trend (β=0.02, P<0.01) over time, but no group difference (β=-0.23, P=0.08). Analysis of the 365 days of self-reported body weight for each participant determined that weight loss was greater over the study period in the WEV+ group than in the WEV group, corresponding to weight changes of -0.67 kg and 1.00 kg, respectively, and an 87% greater weight loss (β=-0.01, P<0.01). Overall compliance to daily tracking was 76%±5%. Daily self-monitoring of weight, physical activity, and F/V consumption is a feasible and effective approach for maintaining weight loss for 12 months, and daily self-monitoring of increased water consumption may provide additional WTLM benefits.

  16. Daily Self-Monitoring of Body Weight, Step Count, Fruit/Vegetable Intake and Water Consumption: A Feasible and Effective Long-Term Weight Loss Maintenance Approach

    PubMed Central

    Akers, Jeremy D.; Cornett, Rachel A.; Savla, Jyoti S.; Davy, Kevin P.; Davy, Brenda M.

    2012-01-01

    Maintenance of weight loss remains a challenge for most individuals, thus practical and effective weight loss maintenance (WTLM) strategies are needed. A two-group (WEV versus WEV+) 12-month WTLM intervention trial was conducted (June 2007–February 2010) to determine the feasibility and effectiveness of weight loss maintenance intervention for older adults using daily self-monitoring of body weight, step count, fruit/vegetable intake and water consumption. Forty weight-reduced (mean weight lost = 6.7 ± 0.6 kg; BMI 29.2 ± 1.1 kg/m2) individuals aged 63 ± 1 yrs, who had previously participated in a 12-week randomized controlled weight loss intervention trial, were instructed to record daily body weight (Weight), step count (Exercise), and fruit/vegetable intake (Vegetable). Experimental group (WEV+) participants were also instructed to consume 16 floz of water before each main meal (i.e., three times daily), and to record daily water intake. Outcome measures included weight change, diet/physical activity behaviors, theoretical constructs related to health behaviors, and other clinical measures. Statistical analyses included growth curve analyses and repeated measures ANOVA. Over 12 months, there was a linear decline in weight (β = −0.32, P < 0.001) and a quadratic trend (β = 0.02, P < 0.01) over time, but no group difference (β = −0.23, P = 0.08). Analysis of the 365 days of self-reported body weight for each participant determined that weight loss was greater over the study period in WEV+ than WEV, corresponding to weight changes of −0.67 kg and 1.00 kg respectively, and an 87% greater weight loss (β = −0.01, P < 0.01). Overall compliance to daily tracking was 76 ± 5%. Daily self-monitoring of weight, physical activity, and fruit/vegetable consumption is a feasible and effective approach for maintaining weight loss for 12 months, and daily self-monitoring of increased water consumption may provide additional WTLM benefits. PMID:22709772

  17. Spontaneous emission from a two-level atom in anisotropic one-band photonic crystals: A fractional calculus approach

    SciTech Connect

    Wu, J.-N.; Huang, C.-H.; Cheng, S.-C.; Hsieh, W.-F.

    2010-02-15

    Spontaneous emission (SE) from a two-level atom in an anisotropic photonic crystal (PC) is investigated by the fractional calculus. Physical phenomena of the SE are studied analytically by solving the fractional kinetic equations of the SE. There is a dynamical discrepancy between the SE of anisotropic and isotropic PCs. We find that, contrary to the SE phenomenon of the isotropic PC, the SE near the band edge of an anisotropic PC shows no photon-atom bound state. It is consistent with the experimental results of Barth, Schuster, Gruber, and Cichos [Phys. Rev. Lett. 96, 243902 (2006)] that the anisotropic property of the system enhances the SE. We also study effects of dispersion curvatures on the changes of the photonic density of states and the appearance of the diffusion fields in the SE.

  18. Lineage depletion of stromal vascular fractions isolated from human adipose tissue: a novel approach towards cell enrichment technology.

    PubMed

    Indumathi, S; Mishra, Rashmi; Harikrishnan, R; Rajkumar, J S; Kantawala, Neha; Dhanasekaran, M

    2014-03-01

    The therapeutic rationale for tissue repair and regeneration using stem cells is at its infancy and needs advancement in understanding the role of individual component's innate capability. As stem cells of adipose tissue reside in a more heterogeneous population of stromal vascular fractions, cell separation or sorting becomes an eminent step towards revealing their unique properties. This study elucidates the comparative efficacy of lineage depleted adipose derived stromal vascular fraction (SVF) and their innate ability using magnetic activated cell sorter (MACS). To this end, isolated SVF from human adipose tissue was lineage depleted according to the manufacturer's instructions using specific antibody cocktail through MACS. The enriched lineage negative (lin-) and lineage positive (lin+) cell fractions were cultured, phenotypically characterized for the panel of cell surface markers using flowcytometry and subjected to osteoblastic and adipogenic differentiation. The expression profile obtained for lin- cells was CD34-/CD45-/HLADR-/CD49d-/CD140b-/CD31-/CD90+/CD105+/CD73+/CD54+/CD166+/CD117- when compared to Lin+ cells expressing CD34+/CD45+/HLADR-/CD49d-/CD140b+/CD31-/CD90+/CD105+/CD73+/CD54+/CD166+/CD117+ (CD-cluster of differentiation). These results, thus, advances our understanding on the inherent property of the individual cell population. Furthermore, both the fractions exhibited mesodermal lineage differentiation capacity. To conclude, this research pursuit rationalized the regenerative therapeutic applicability of both lin- and lin+ cultures of human adipose tissue for disorders of mesodermal, haematological and vascular origin.

  19. Evolving approaches to the management of heart failure with preserved ejection fraction in patients with coronary artery disease.

    PubMed

    Shah, Sanjiv J

    2010-01-01

    Coronary artery disease (CAD) is a major cause of heart failure with preserved ejection fraction (HFpEF). In studies of HFpEF, the reported prevalence of CAD varies widely, which may be the result of inconsistent definitions of CAD, geographic and ethnic differences in CAD burden, varying definitions of HFpEF (including different cutoffs for "preserved ejection fraction"), and differences in study design. Despite these limitations, pooled analysis of prospective HFpEF studies demonstrates that CAD is common in HFpEF, with an estimated prevalence of approximately 50%. Based on available data, patients with signs and symptoms of heart failure who have preserved left ventricular ejection fraction and evidence of CAD (HFpEF-CAD) most likely comprise a distinct etiologic and pathophysiologic subset of HFpEF. Therefore, future clinical trials in HFpEF should a priori stratify by CAD or specifically target patients with CAD, strategies that may improve the disappointing track record of therapies tested in HFpEF. The combination of systematic evaluation and management of CAD in HFpEF, along with promising future therapies for HFpEF-CAD, may lead to improved outcomes for this challenging clinical syndrome.

  20. Environmental attributable fractions in remote Australia: the potential of a new approach for local public health action.

    PubMed

    McMullen, Cheryl; Eastwood, Ashley; Ward, Jeanette

    2016-04-01

    To determine local values for environmental attributable fractions and explore their applicability and potential for public health advocacy. Using World Health Organization (WHO) values for environmental attributable fractions, responses from a practitioner survey (73% response rate) were considered by a smaller skills-based panel to determine consensus values for Kimberley environmental attributable fractions (KEAFs). Applied to de-identified data from 17 remote primary healthcare facilities over two years, numbers and proportions of reasons for attendance directly attributable to the environment were calculated for all ages and children aged 0-4 years, including those for Aboriginal patients. Of 150,357 reasons for attendance for patients of all ages, 31,775 (21.1%) were directly attributable to the environment. The proportion of these directly due to the environment was significantly higher for Aboriginal patients than others (23.1% v 14.6%; p<0.001). Of 29,706 reasons for attendance by Aboriginal children aged 0-4 years, 7,599 (25.6%) were directly attributable to the environment, significantly higher than for non-Aboriginal children aged 0-4 years (25.6% v 18.6%; p<0.001). By addressing environmental factors, 20% of total primary healthcare demand could be prevented and, importantly, some 25% of presentations by Aboriginal children. KEAFs have potential to monitor impact of local environmental investments. © 2015 Public Health Association of Australia.

  1. Role of islet-, gut-, and adipocyte-derived hormones in the central control of food intake and body weight: implications for an integrated neurohormonal approach to obesity pharmacotherapy.

    PubMed

    Chen, Hubert C; Roth, Jonathan D; Schroeder, Brock E; Weyer, Christian

    2008-05-01

    Contrary to its historical epithet as a lifestyle disorder, obesity is now widely recognized as having a neurobiological basis. This progress is due to our knowledge not only about energy homoeostatic pathways within the central nervous system (CNS), but also about the role of peripheral peptide hormones acting upon the CNS. These hormones include long-term adiposity signals, such as leptin, that inform the CNS primarily of changes in the body's overall fat and energy reserves, and short-term signals such as amylin, peptide YY (PYY) and ghrelin, that primarily reflect changes in the immediate nutritive state (energy intake). The limited weight loss effects achieved with current monotherapy approaches to obesity have been attributed, at least in part, to the redundancies and potent counter-regulatory responses within the neurohormonal feedback loop governing energy balance. Recently, we reported that combinations of amylin, leptin and PYY(3-36) resulted in additive and/or synergistic interactions and caused marked weight loss in the diet-induced obese rat model, which to date has reasonably predicted the clinical effects of several hormones in obese humans. If confirmed in ongoing translational clinical research studies, these findings may provide a physiological rationale for a novel, integrated neurohormonal approach to pharmacotherapy for obesity.

  2. Investigating the Partitioning of Inorganic Elements Consumed by Humans between the Various Fractions of Human Wastes: An Alternative Approach

    NASA Technical Reports Server (NTRS)

    Wignarajah, Kanapathipillai; Pisharody, Suresh; Fisher, John W.

    2003-01-01

    The elemental composition of food consumed by astronauts is well defined. The major elements carbon, hydrogen, oxygen, nitrogen and sulfur are taken up in large amounts and these are often associated with the organic fraction (carbohydrates, proteins, fats etc) of human tissue. On the other hand, a number of the elements are located in the extracellular fluids and can be accounted for in the liquid and solid waste fraction of humans. These elements fall into three major categories - cationic macroelements (e.g. Ca, K, Na, Mg and Si), anionic macroelements (e.g. P, S and Cl and 17 essential microelements, (e.g. Fe, Mn, Cr, Co, Cu, Zn, Se and Sr). When provided in the recommended concentrations to an adult healthy human, these elements should not normally accumulate in humans and will eventually be excreted in the different human wastes. Knowledge of the partitioning of these elements between the different human waste fractions is important in understanding (a) developing waste separation technologies, (b) decision-making on how these elements can be recovered for reuse in space habitats, and (c) to developing the processors for waste management. Though considerable literature exists on these elements, there is a lack of understanding and often conflicting data. Two major reasons for these problems include the lack of controlled experimental protocols and the inherently large variations between human subjects (Parker and Gallagher, 1988). We have used the existing knowledge of human nutrition and waste from the available literature and NASA documentation to build towards a consensus to typify and chemically characterize the various human wastes. It is our belief, that this could be a building block towards integrating a human life support and waste processing in a closed system.

  3. Evaluating a novel dimensional reduction approach for mechanical fractionation of cells using a tandem flexible micro spring array (tFMSA).

    PubMed

    Yeh, Yin-Ting; Harouaka, Ramdane A; Zheng, Si-Yang

    2017-02-14

    We present a novel methodology to establish experimental models for the rational design of cell fractionation based on physical properties of cells. Label-free microfluidic separation of cells based on size is a widely employed technique. However, close observation reveals that cell capture results cannot be explained by cell sizes alone. This is particularly apparent with viable cell fractionation, where cells retain their native deformability. We have developed a principal size cutoff (PSC) model based on the analysis of size distribution and size-based filtration efficiency for cell populations. The goal of this analysis is to use an unbiased approach to achieve dimensional reduction of deformability and other mechanical properties that affect cell capture. The PSC model provides a single calibrated principal size component that may be compared directly to device gap width, which is the critical dimension for cell filtration. The PSC model was evaluated experimentally using a tandem flexible micro spring array (tFMSA) device made of parylene filtration elements applied within micro-molded polydimethylsiloxane (PDMS) chambers. In the tFMSA device, a mixture of cells is sequentially passed through individual filters with decreasing gap widths to allow size-based selection. We applied this method to demonstrate viable separation of subgroups of cells with different mechanical properties from complex mixtures, including fractionation according to cancer cell type, cell cycle stage, cell viability status, and leukocyte nuclear phenotype. The PSC methodology and tFMSA device can advance a better understanding of complex factors affecting mechanical cell fractionation and provide a miniature platform for obtaining rationally designed cell fractions for biomedical applications.

  4. Omega-3 Polyunsaturated Fatty Acids Intake to Regulate Helicobacter pylori-Associated Gastric Diseases as Nonantimicrobial Dietary Approach

    PubMed Central

    Park, Jong-Min; Jeong, Migyeong; Kim, Eun-Hee; Han, Young-Min; Kwon, Sung Hun; Hahm, Ki-Baik

    2015-01-01

    Omega-3 polyunsaturated fatty acids (n-3 PUFAs), commonly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been acknowledged as essential long-chain fatty acids imposing either optimal health promotion or the rescuing from chronic inflammatory diseases such as atherosclerosis, fatty liver, and various inflammatory gastrointestinal diseases. Recent studies dealing with EPA and DHA have sparked highest interests because detailed molecular mechanisms had been documented with the identification of its receptor, G protein coupled receptor, and GPR120. In this review article, we have described clear evidences showing that n-3 PUFAs could reduce various Helicobacter pylori- (H. pylori-) associated gastric diseases and extended to play even cancer preventive outcomes including H. pylori-associated gastric cancer by influencing multiple targets, including proliferation, survival, angiogenesis, inflammation, and metastasis. Since our previous studies strongly concluded that nonantimicrobial dietary approach for reducing inflammation, for instance, application of phytoceuticals, probiotics, natural products including Korean red ginseng, and walnut plentiful of n-3 PUFAs, might be prerequisite step for preventing H. pylori-associated gastric cancer as well as facilitating the rejuvenation of precancerous atrophic gastritis, these beneficial lipids can restore or modify inflammation-associated lipid distortion and correction of altered lipid rafts to send right signaling to maintain healthy stomach even after chronic H. pylori infection. PMID:26339635

  5. Leaf area index retrieval using gap fractions obtained from high resolution satellite data: Comparisons of approaches, scales and atmospheric effects

    NASA Astrophysics Data System (ADS)

    Gonsamo, Alemu

    2010-08-01

    This study is aimed at demonstrating the feasibility of the large scale LAI inversion algorithms using red and near infrared reflectance obtained from high resolution satellite imagery. Radiances in digital counts were obtained in 10 m resolution acquired on cloud free day of August 23, 2007, by the SPOT 5 high resolution geometric (HRG) instrument on mostly temperate hardwood forest located in the Great Lakes - St. Lawrence forest in Southern Quebec. Normalized difference vegetation index (NDVI), scaled difference vegetation index (SDVI) and modified soil-adjusted vegetation index (MSAVI) were applied to calculate gap fractions. LAI was inverted from the gap fraction using the common Beer-Lambert's law of light extinction under forest canopy. The robustness of the algorithm was evaluated using the ground-based LAI measurements and by applying the methods for the independently simulated reflectance data using PROSPECT + SAIL coupled radiative transfer models. Furthermore, the high resolution LAI was compared with MODIS LAI product. The effects of atmospheric corrections and scales were investigated for all of the LAI retrieval methods. NDVI was found to be not suitable index for large scale LAI inversion due to the sensitivity to scale and atmospheric effects. SDVI was virtually scale and atmospheric correction invariant. MSAVI was also scale invariant. Considering all sensitivity analysis, MSAVI performed best followed by SDVI for robust LAI inversion from high resolution imagery.

  6. A generalized fuzzy credibility-constrained linear fractional programming approach for optimal irrigation water allocation under uncertainty

    NASA Astrophysics Data System (ADS)

    Zhang, Chenglong; Guo, Ping

    2017-10-01

    The vague and fuzzy parametric information is a challenging issue in irrigation water management problems. In response to this problem, a generalized fuzzy credibility-constrained linear fractional programming (GFCCFP) model is developed for optimal irrigation water allocation under uncertainty. The model can be derived from integrating generalized fuzzy credibility-constrained programming (GFCCP) into a linear fractional programming (LFP) optimization framework. Therefore, it can solve ratio optimization problems associated with fuzzy parameters, and examine the variation of results under different credibility levels and weight coefficients of possibility and necessary. It has advantages in: (1) balancing the economic and resources objectives directly; (2) analyzing system efficiency; (3) generating more flexible decision solutions by giving different credibility levels and weight coefficients of possibility and (4) supporting in-depth analysis of the interrelationships among system efficiency, credibility level and weight coefficient. The model is applied to a case study of irrigation water allocation in the middle reaches of Heihe River Basin, northwest China. Therefore, optimal irrigation water allocation solutions from the GFCCFP model can be obtained. Moreover, factorial analysis on the two parameters (i.e. λ and γ) indicates that the weight coefficient is a main factor compared with credibility level for system efficiency. These results can be effective for support reasonable irrigation water resources management and agricultural production.

  7. Municipal solid waste management planning for Xiamen City, China: a stochastic fractional inventory-theory-based approach.

    PubMed

    Chen, Xiujuan; Huang, Guohe; Zhao, Shan; Cheng, Guanhui; Wu, Yinghui; Zhu, Hua

    2017-09-09

    In this study, a stochastic fractional inventory-theory-based waste management planning (SFIWP) model was developed and applied for supporting long-term planning of the municipal solid waste (MSW) management in Xiamen City, the special economic zone of Fujian Province, China. In the SFIWP model, the techniques of inventory model, stochastic linear fractional programming, and mixed-integer linear programming were integrated in a framework. Issues of waste inventory in MSW management system were solved, and the system efficiency was maximized through considering maximum net-diverted wastes under various constraint-violation risks. Decision alternatives for waste allocation and capacity expansion were also provided for MSW management planning in Xiamen. The obtained results showed that about 4.24 × 10(6) t of waste would be diverted from landfills when p i is 0.01, which accounted for 93% of waste in Xiamen City, and the waste diversion per unit of cost would be 26.327 × 10(3) t per $10(6). The capacities of MSW management facilities including incinerators, composting facility, and landfills would be expanded due to increasing waste generation rate.

  8. Imperfect fractional crystallization of the lunar magma ocean and formation of the lunar mantle: A realistic chemical approach

    NASA Technical Reports Server (NTRS)

    Snyder, Gregory A.; Taylor, Lawrence A.

    1992-01-01

    It is generally considered that lunar mare basalts were generated by the melting of a cumulate mantle formed in an early Moon-wide magma ocean or magmasphere. However, the nature and chemistry of this cumulate mantle and the logistics of its origin have remained elusive. Extensive studies of terrestrial layered mafic intrusions over the past sixty years have emphasized the imperfection of fractional crystallization and attendant crystal-crystal and crystal-liquid separation in a convecting magma chamber. These separations were similarly inefficient during evolution of the lunar magmasphere, allowing for the trapping of interstitial melt and entrainment of a small proportion of less-dense plagioclase into the more-dense mafic cumulate mush. Indeed, petrography of lunar highlands samples demonstrates this well for anorthosites (with 1-10 percent olivine). Therefore, we propose a 'realistic' model for the evolution of the lunar mantle, which takes these observations into consideration, by the imperfect fractional crystallization of an early lunar magma ocean.

  9. Food-based recommendations to reduce fat intake: an evidence-based approach to the development of a family-focused child weight management programme.

    PubMed

    Gehling, R K; Magarey, A M; Daniels, L A

    2005-03-01

    To develop food-based recommendations to lower fat and energy intake for use in a family-focussed weight management programme for 6-9 year old children. Secondary analysis of the 1995 National Nutrition Survey (NNS95) informed the development of food-based recommendations aiming to reduce fat and energy intake. Each recommendation was used to progressively modify a model 3-day high fat dietary intake with the accumulative effect on energy and nutrient intake of each recommendation assessed. Six to nine-year-olds in the NNS95 consuming 35-45% energy as fat (n= 280) consumed more total energy (mean +/- SD, 8671 +/- 2741 vs. 7571 +/- 2328 kJ/day) than children consuming a 'low fat' (23-27% energy as fat, n= 85) diet (P < 0.002). Food-based recommendations found to be most effective for reducing energy and fat intake included; changing to reduced fat milk, reducing intake of cereal-based and snack foods and replacing juice or soft drink with water. These changes, together with avoiding adding fat to vegetables and using sources of lean meat, reduced energy intake by approximately 10%, total fat intake by approximately 30% and saturated fat intake by 53%. Modifying six areas of food choices results in a moderate reduction in fat and energy intake. An eating pattern that is consistent with Australian dietary guidelines and uses foods commonly eaten by children is achievable for children aged 6-9 years. These food-based recommendations provide an evidence-based dietary framework for prevention and management of overweight in children.

  10. An innovative approach for sequential extraction of phosphorus in sediments: Ferrous iron P as an independent P fraction.

    PubMed

    Gu, Sen; Qian, Yiguang; Jiao, Yang; Li, Qingman; Pinay, Gilles; Gruau, Gerard

    2016-10-15

    Accurate identification of phosphorus (P) forms is crucially important for understanding the geochemical cycle of P; however, until now the role of ferrous iron P (Fe(II)-P) buried in sediments has been completely ignored in nearly all sequential extraction procedures developed. Using sediment cores sampled from Donghu Lake in Wuhan, China, this study explored a modified version of widely used sequential P extraction method (SEDEX; Ruttenberg, 1992) in which Fe(II)-P was identified as an independent fraction. Based on the high selectivity of the extractant (0.2% 2,2'-bipyridine+0.1 M KCl) and the dissolution equilibrium of P, procedures for extracting Fe(II)-P were optimized using a 1:100 solid:liquid ratio and extraction at 50 ± 1 °C for 24 h. The sedimentary P extracted was divided into five fractions: loosely-bound P, Fe(II)-P, CDB-P, Ca-P and O-P. Fe(II)-P was the predominant fraction in fresh sediments in Donghu Lake, accounting for 15.7-49.9% of TP, with a mean of 31.6%. The mean values of Ca-P, O-P, CDB-P and loosely-bound P were 28.4%, 22.7%, 17.1% and 4.3%, respectively. Combined with component analysis of extracts and recovery experiments of standard reference minerals (vivianite, Fe3(PO4)2·8H2O) in natural sediments, extraction of Fe(II)-P with 0.2% 2,2-bipridine and 0.1 M KCl was robust, with a good recovery rate (88.7-100.6%) and little of the Ca-P dissolved. It is possible to use this innovative SEDEX not only to distinguish the contribution of different P matrices in fresh sediments, but also to investigate the transformation of sedimentary P under different redox conditions. Therefore, greater focus on Fe(II)-P is necessary, because it is a major sink for the geochemical process of sedimentary P. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. α-HCH enantiomer fraction (EF): A novel approach to calculate the ventilation age of water in the Arctic Ocean?

    NASA Astrophysics Data System (ADS)

    Pućko, Monika; Macdonald, Robie W.; Barber, David G.; Rosenberg, Bruno; Gratton, Yves; Stern, Gary A.

    2012-08-01

    α-HCH (hexachlorocyclohexane) and the enantiomeric fraction (EF) of its mirror-image isomers have been determined for water column profiles in the southern Beaufort Sea in 2004 and 2007. Using estimated rates of metabolic degradation, we have applied a simple kinetic model to convert the observed EFs to apparent ventilation ages of the water masses in the study region. We found an age of 1.7 ± 0.1 years for the Polar Mixed Layer (PML), 6.6 ± 0.6 for the core of the Pacific Layer centered at salinity 33.1, and 21.7 ± 0.5 years for the core of the Atlantic Layer identified by a Tmax of ˜0.5°C. These ages are in reasonable accord with other methods used to date water masses in the Arctic Ocean suggesting that α-HCH has an unexploited potential as a dating tool.

  12. A systematic approach for the chromatographic fractionation and purification of major steroid saponins in commercial extracts of Yucca schidigera Roezl.

    PubMed

    Sastre, F; Ferreira, F; Pedreschi, F

    2017-03-01

    Yucca schidigera Roezl. (yucca) is one of the major industrial sources of steroid saponins used as animal and human food additives. This work describes a new, systematic and reproducible three-step method by medium and high-pressure liquid chromatography (under RP, NP and RP conditions), for the isolation and purification of three groups of saponins, which were further purified in six sub-fractions, and finally into twelve individual steroid saponins previously reported in Y. schidigera. In accordance to the increasing applications of yucca extracts, further analytical, biological and physicochemical studies are still required. The presented method is applicable to the preparation of steroids saponins previously reported in commercial extracts of Y. schidigera, both as highly purified mixtures of defined composition, including twelve pure components.

  13. Fractional Diffusion Analysis of the Electromagnetic Field In Fractured Media Part II: 2.5-D Approach

    NASA Astrophysics Data System (ADS)

    Ge, J.; Everett, M. E.; Weiss, C. J.

    2012-12-01

    A 2.5D finite difference (FD) frequency-domain modeling algorithm based on the theory of fractional diffusion of electromagnetic (EM) fields generated by a loop source lying above a fractured geological medium is addressed in this paper. The presence of fractures in the subsurface, usually containing highly conductive pore fluids, gives rise to spatially hierarchical flow paths of induced EM eddy currents. The diffusion of EM eddy currents in such formations is anomalous, generalizing the classical Gaussian process described by the conventional Maxwell equations. Based on the continuous time random walk (CTRW) theory, the diffusion of EM eddy currents in a rough medium is governed by the fractional Maxwell equations. Here, we model the EM response of a 2D subsurface containing fractured zones, with a 3D loop source, which results the so-called 2.5D model geometry. The governing equation in the frequency domain is converted using Fourier transform into k domain along the strike direction (along which the model conductivity doesn't vary). The resulting equation system is solved by the multifrontal massively parallel solver (MUMPS). The data obtained is then converted back to spatial domain and the time domain. We find excellent agreement between the FD and analytic solutions for a rough halfspace model. Then FD solutions are calculated for a 2D fault zone model with variable conductivity and roughness. We compare the results with responses from several classical models and explore the relationship between the roughness and the spatial density of the fracture distribution.

  14. Beyond long memory in heart rate variability: An approach based on fractionally integrated autoregressive moving average time series models with conditional heteroscedasticity

    NASA Astrophysics Data System (ADS)

    Leite, Argentina; Paula Rocha, Ana; Eduarda Silva, Maria

    2013-06-01

    Heart Rate Variability (HRV) series exhibit long memory and time-varying conditional variance. This work considers the Fractionally Integrated AutoRegressive Moving Average (ARFIMA) models with Generalized AutoRegressive Conditional Heteroscedastic (GARCH) errors. ARFIMA-GARCH models may be used to capture and remove long memory and estimate the conditional volatility in 24 h HRV recordings. The ARFIMA-GARCH approach is applied to fifteen long term HRV series available at Physionet, leading to the discrimination among normal individuals, heart failure patients, and patients with atrial fibrillation.

  15. Effects of sodium intake and diet on racial differences in urinary potassium excretion: results from the Dietary Approaches to Stop Hypertension (DASH)-Sodium trial.

    PubMed

    Turban, Sharon; Thompson, Carol B; Parekh, Rulan S; Appel, Lawrence J

    2013-01-01

    We previously showed that African Americans excreted less urinary potassium than whites, even while consuming similar diets in the Dietary Approaches to Stop Hypertension (DASH) trial. We hypothesized that a low-sodium diet may eliminate these differences. Data from the DASH-Sodium randomized controlled feeding trial were analyzed. 412 adults with prehypertension or stage 1 hypertension. Random assignment to either a typical American "control" diet (1.7 g [43 mEq] potassium/2,100 kcal/d) or the DASH diet (4.1 g [105 mEq] potassium/2,100 kcal/d). Within each diet, participants received 3 levels of sodium intake in random order for 30 days. 24-hour urine samples were analyzed at the end of each period. The primary outcome was urinary potassium excretion. On the DASH diet, African Americans consistently excreted significantly less urinary potassium (mean 24-hour urinary potassium excretion, 2,594 ± 961 mg [66 ± 25 mEq]) than whites (3,412 ± 1,016 mg [87 ± 26 mEq]) at the highest sodium level; adjusted (P < 0.001); this difference was not altered by sodium level (P = 0.6 comparing white to African American difference in urinary potassium excretion on high- vs low-sodium diet). In contrast, there was a smaller but significant white-African American difference in mean daily urinary potassium excretion in participants fed the control/high-sodium diet that was not present in the control/low-sodium diet (adjusted differences of 281 mg [7 mEq]/d vs 20 mg [0.5 mEq]/d, respectively; P = 0.007). Significant interactions were found between race and diet (P < 0.001) and between race and sodium (P = 0.02). Single rather than multiple urine collections were available at each time. Lack of stool potassium and sweat potassium values. Racial differences in urinary potassium excretion depend on sodium intake and diet. Our results may help explain the previously documented large variability in urinary potassium excretion. Copyright © 2012 National Kidney Foundation, Inc. Published

  16. A restricted cubic spline approach to assess the association between high fat fish intake and red blood cell EPA + DHA content.

    PubMed

    Sirot, V; Dumas, C; Desquilbet, L; Mariotti, F; Legrand, P; Catheline, D; Leblanc, J-C; Margaritis, I

    2012-04-01

    Fish, especially fatty fish, are the main contributor to eicosapentaenoic (EPA) and docosahexaenoic (DHA) intake. EPA and DHA concentrations in red blood cells (RBC) has been proposed as a cardiovascular risk factor, with <4% and >8% associated with the lowest and greatest protection, respectively. The relationship between high fat fish (HFF) intake and RBC EPA + DHA content has been little investigated on a wide range of fish intake, and may be non-linear. We aimed to study the shape of this relationship among high seafood consumers. Seafood consumption records and blood were collected from 384 French heavy seafood consumers and EPA and DHA were measured in RBC. A multivariate linear regression was performed using restricted cubic splines to consider potential non-linear associations. Thirty-six percent of subjects had an RBC EPA + DHA content lower than 4% and only 5% exceeded 8%. HFF consumption was significantly associated with RBC EPA + DHA content (P [overall association] = 0.021) adjusted for sex, tobacco status, study area, socioeconomic status, age, alcohol, other seafood, meat, and meat product intakes. This relationship was non-linear: for intakes higher than 200 g/wk, EPA + DHA content tended to stagnate. Tobacco status and fish contaminants were negatively associated with RBC EPA + DHA content. Because of the saturation for high intakes, and accounting for the concern with exposure to trace element contaminants, intake not exceeding 200 g should be considered. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Results from an experimental trial at a Head Start center to evaluate two meal service approaches to increase fruit and vegetable intake of preschool aged children.

    PubMed

    Harnack, Lisa J; Oakes, J Michael; French, Simone A; Rydell, Sarah A; Farah, Farhiyah M; Taylor, Gretchen L

    2012-04-30

    Strategies to increase fruit and vegetable consumption of preschool aged children are needed. Evaluate the independent effects of the following meal service strategies on intake of fruits and vegetables of preschool children: 1.) Serving fruits and vegetables in advance of other menu items as part of traditional family style meal service; and 2.) Serving meals portioned and plated by providers. Fifty-three preschool aged children completed a randomized crossover experiment conducted at a Head Start center in Minneapolis, MN. Over a six week trial period each of the experimental meal service strategies (serving fruits and vegetable first and serving meals portioned by providers) was implemented during lunch service for two one-week periods. Two one-week control periods (traditional family style meal service with all menu items served at once) were also included over the six week trial period. Childrens lunch intake was observed as a measure of food and nutrient intake during each experimental condition. Fruit intake was significantly higher (p<0.01) when fruits and vegetables were served in advance of other meal items (0.40 servings/meal) compared to the traditional family style meal service control condition when they were served in tandem with other menu items (0.32 servings/meal). Intakes of some nutrients found in fruits (vitamin A and folate) were concomitantly higher. In contrast, fruit and vegetable intakes were significantly lower and energy intake significantly higher during the provider portioned compared with control condition. Serving fruits in advance of other meal items may be a low cost easy to implement strategy for increasing fruit intake in young children. However, serving vegetables first does not appear to increase vegetable intake. Results provide support for current recommendations for traditional family style meal service in preschool settings.

  18. Worldwide trends in dietary sugars intake.

    PubMed

    Wittekind, Anna; Walton, Janette

    2014-12-01

    Estimating trends in dietary intake data is integral to informing national nutrition policy and monitoring progress towards dietary guidelines. Dietary intake of sugars is a controversial public health issue and guidance in relation to recommended intakes is particularly inconsistent. Published data relating to trends in sugars intake are relatively sparse. The purpose of the present review was to collate and review data from national nutrition surveys to examine changes and trends in dietary sugars intake. Only thirteen countries (all in the developed world) appear to report estimates of sugars intake from national nutrition surveys at more than one point in time. Definitions of dietary sugars that were used include 'total sugars', 'non-milk extrinsic sugars', 'added sugars', sucrose' and 'mono- and disaccharides'. This variability in terminology across countries meant that comparisons were limited to within countries. Hence trends in dietary sugars intake were examined by country for the whole population (where data permitted), and for specific or combined age and sex subpopulations. Findings indicate that in the majority of population comparisons, estimated dietary sugars intake is either stable or decreasing in both absolute (g/d) and relative (% energy) terms. An increase in sugars intake was observed in few countries and only in specific subpopulations. In conclusion, the findings from the present review suggest that, in the main, dietary sugars intake are decreasing or stable. A consistent approach to estimation of dietary sugars intake from national nutrition surveys is required if more valid estimates of changes in dietary sugars intakes are required in the future.

  19. Assessing the risk of an excess fluoride intake among Swedish children in households with private wells--expanding static single-source methods to a probabilistic multi-exposure-pathway approach.

    PubMed

    Augustsson, Anna; Berger, Tobias

    2014-07-01

    It is often assumed that water consumption is the major route of exposure for fluoride and analysis of water fluoride content is the most common approach for ensuring that the daily intake is not too high. In the present study, the risk of excess intake was characterized for children in households with private wells in Kalmar County, Sweden, where the natural geology shows local enrichments in fluorine. By comparing water concentrations with the WHO drinking water guideline (1.5 mg/L), it was found that 24% of the ca. 4800 sampled wells had a concentration above this limit, hence providing a figure for the number of children in the households concerned assessed to be at risk using this straightforward approach. The risk of an excess intake could, alternatively, also be characterized based on a tolerable daily intake (in this case the US EPA RfD of 0.06 mg/kg-day). The exposure to be evaluated was calculated using a probabilistic approach, where the variability in all exposure factors was considered, again for the same study population. The proportion of children assessed to be at risk after exposure from drinking water now increased to 48%, and when the probabilistic model was adjusted to also include other possible exposure pathways; beverages and food, ingestion of toothpaste, oral soil intake and dust inhalation, the number increased to 77%. Firstly, these results show how the risk characterization is affected by the basis of comparison. In this example, both of the reference values used are widely acknowledged. Secondly, it illustrates how much of the total exposure may be overlooked when only focusing on one exposure pathway, and thirdly, it shows the importance of considering the variability in all relevant pathways. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Metallomics approach to trace element analysis in ustilago maydis using cellular fractionation, atomic absorption spectrometry, and size exclusion chromatography with ICP-MS detection.

    PubMed

    Muñoz, Alma Hortensia Serafin; Kubachka, Kevin; Wrobel, Kazimierz; Corona, Felix Gutierrez; Yathavakilla, Santha K V; Caruso, Joseph A; Wrobel, Katarzyna

    2005-06-29

    Huitlacoche is the ethnic name of the young fruiting bodies of Ustilago maydis, a common parasite of maize. In Mexico and other Latin American countries, this fungus has been traditionally appreciated as a local delicacy. In this work a metallomics approach was used with the determination of eight elements in huitlacoche by electrothermal atomic absorption spectrometry as one facet of this approach. The results obtained indicated relatively lower concentrations of commonly analyzed metals, as referred to the data reported for other mushroom types. This effect was ascribed to different accessibilities of elements, depending on fungus substrate (lower from plant than from soil). Subcellular fractionation was accomplished by centrifugation of cell homogenates suspended in Tris-HCl buffer. Recoveries of the fractionation procedure were in the range of 71-103%. For six elements (Cr, Cu, Fe, Mn, Ni, and Pb), the mean relative contributions in cytosol, cell walls, and mixed membrane fraction were 50.7, 48.2, and 1.1% respectively. To attain the molecular weight distribution of compounds containing target elements as an additional aspect of the metallomics approach, the fungus extract (1% sodium dodecyl sulfate in Tris-HCl, 30 mmol L(-)(1), pH 7.0) was analyzed by size exclusion chromatography with UV and ICP-MS detection. With spectrophotometric detection (280 nm), the elution of high molecular weight compounds was observed in the form of one peak (MW > 10 kDa), and several lower peaks appeared at higher retention times (MW < 10 kDa). On ICP-MS chromatograms, a coelution of (59)Co, (63)Cu, (57)Fe, (202)Hg, (60)Ni, and (80)Se with the first peak on the UV chromatogram was clearly observed, indicating that a fraction of each element incorporated with high molecular weight compounds (12.7, 19.8, 33.7, 100, 19.4, and 45.8%, respectively, based on the peak area measurements). From a comparison of (80)Se and (33)S chromatograms (for sulfur analysis, the extract was obtained in

  1. Real-Time Noise Removal for Line-Scanning Hyperspectral Devices Using a Minimum Noise Fraction-Based Approach

    PubMed Central

    Bjorgan, Asgeir; Randeberg, Lise Lyngsnes

    2015-01-01

    Processing line-by-line and in real-time can be convenient for some applications of line-scanning hyperspectral imaging technology. Some types of processing, like inverse modeling and spectral analysis, can be sensitive to noise. The MNF (minimum noise fraction) transform provides suitable denoising performance, but requires full image availability for the estimation of image and noise statistics. In this work, a modified algorithm is proposed. Incrementally-updated statistics enables the algorithm to denoise the image line-by-line. The denoising performance has been compared to conventional MNF and found to be equal. With a satisfying denoising performance and real-time implementation, the developed algorithm can denoise line-scanned hyperspectral images in real-time. The elimination of waiting time before denoised data are available is an important step towards real-time visualization of processed hyperspectral data. The source code can be found at http://www.github.com/ntnu-bioopt/mnf. This includes an implementation of conventional MNF denoising. PMID:25654717

  2. Real-time noise removal for line-scanning hyperspectral devices using a minimum noise fraction-based approach.

    PubMed

    Bjorgan, Asgeir; Randeberg, Lise Lyngsnes

    2015-02-03

    Processing line-by-line and in real-time can be convenient for some applications of line-scanning hyperspectral imaging technology. Some types of processing, like inverse modeling and spectral analysis, can be sensitive to noise. The MNF (minimum noise fraction) transform provides suitable denoising performance, but requires full image availability for the estimation of image and noise statistics. In this work, a modified algorithm is proposed. Incrementally-updated statistics enables the algorithm to denoise the image line-by-line. The denoising performance has been compared to conventional MNF and found to be equal. With a satisfying denoising performance and real-time implementation, the developed algorithm can denoise line-scanned hyperspectral images in real-time. The elimination of waiting time before denoised data are available is an important step towards real-time visualization of processed hyperspectral data. The source code can be found at http://www.github.com/ntnu-bioopt/mnf. This includes an implementation of conventional MNF denoising.

  3. Differentiation of lemon essential oil based on volatile and non-volatile fractions with various analytical techniques: a metabolomic approach.

    PubMed

    Mehl, Florence; Marti, Guillaume; Boccard, Julien; Debrus, Benjamin; Merle, Philippe; Delort, Estelle; Baroux, Lucie; Raymo, Vilfredo; Velazco, Maria Inés; Sommer, Horst; Wolfender, Jean-Luc; Rudaz, Serge

    2014-01-15

    Due to the importance of citrus lemon oil for the industry, fast and reliable analytical methods that allow the authentication and/or classification of such oil, using the origin of production or extraction process, are necessary. To evaluate the potential of volatile and non-volatile fractions for classification purposes, volatile compounds of cold-pressed lemon oils were analyzed, using GC-FID/MS and FT-MIR, while the non-volatile residues were studied, using FT-MIR, (1)H-NMR and UHPLC-TOF-MS. 64 Lemon oil samples from Argentina, Spain and Italy were considered. Unsupervised and supervised multivariate analyses were sequentially performed on various data blocks obtained by the above techniques. Successful data treatments led to statistically significant models that discriminated and classified cold-pressed lemon oils according to their geographic origin, as well as their production processes. Studying the loadings allowed highlighting of important classes of discriminant variables that corresponded to putative or identified chemical functions and compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Survival probability of an immobile target in a sea of evanescent diffusive or subdiffusive traps: A fractional equation approach

    NASA Astrophysics Data System (ADS)

    Abad, E.; Yuste, S. B.; Lindenberg, Katja

    2012-12-01

    We calculate the survival probability of an immobile target surrounded by a sea of uncorrelated diffusive or subdiffusive evanescent traps (i.e., traps that disappear in the course of their motion). Our calculation is based on a fractional reaction-subdiffusion equation derived from a continuous time random walk model of the system. Contrary to an earlier method valid only in one dimension (d=1), the equation is applicable in any Euclidean dimension d and elucidates the interplay between anomalous subdiffusive transport, the irreversible evanescence reaction, and the dimension in which both the traps and the target are embedded. Explicit results for the survival probability of the target are obtained for a density ρ(t) of traps which decays (i) exponentially and (ii) as a power law. In the former case, the target has a finite asymptotic survival probability in all integer dimensions, whereas in the latter case there are several regimes where the values of the decay exponent for ρ(t) and the anomalous diffusion exponent of the traps determine whether or not the target has a chance of eternal survival in one, two, and three dimensions.

  5. Factors affecting recall rate and false positive fraction in breast cancer screening with breast tomosynthesis - A statistical approach.

    PubMed

    Rosso, Aldana; Lång, Kristina; Petersson, Ingemar F; Zackrisson, Sophia

    2015-10-01

    In this study, we investigate which factors affect the false positive fraction (FPF) for digital breast tomosynthesis (DBT) compared to digital mammography (DM) in a screening population by using classification and regression trees (C&RT) and binary marginal generalized linear models. The data was obtained from the Malmö Breast Tomosynthesis Screening Trial, which aimed to compare the performance of DBT to DM in breast cancer screening. By using data from the first half of the study population (7500 women), a tree with the recall probability for different groups was calculated. The effect of age and breast density on the FPF was estimated using a binary marginal generalized linear model. Our results show that breast density and breast cancer were the main factors influencing recall. The FPF is mainly affected by breast density and increases with breast density for DBT and DM. In conclusion, the results obtained with C&RT are easy to interpret and similar to those obtained using binary marginal generalized linear models. The FPF is approximately 40% higher for DBT compared to DM for all breast density categories.

  6. Field-flow fractionation: An efficient approach for matrix removal of soil extract for inductively coupled plasma optical emission spectrometry

    NASA Astrophysics Data System (ADS)

    Sangsawong, Supharart; Waiyawat, Weerawan; Shiowatana, Juwadee; Siripinyanond, Atitaya

    2011-06-01

    An on-line coupling between a continuous-flow sequential extraction (CFSE) unit and flow field-flow fractionation with cross flow matrix removal (FlFFF/CFM) with ICP-OES detection was developed for determination of metal leachability from soil. The use of high concentration of Mg(NO 3) 2 in exchangeable phase can cause undesirable matrix effects by shifting ionization equilibrium in the plasma, etc., resulting in a clear need for matrix removal. Therefore, the capability of FlFFF/CFM to remove Mg matrix ion from soil extract was evaluated. Poly(ethylene imine) (PEI) having molecular weight of 25,000 Da was added to form complexes with analyte elements (Cu, Mn, Pb, and Zn) but not the matrix element (Mg). The free Mg matrix ions were then removed by filtering off through the ultrafiltration membrane, having a 1000-Da molecular weight cut-off, inside the FlFFF channel. With the use of FlFFF/CFM, matrix removal efficiency was approximately 83.5%, which was equivalent to approximately 6-fold dilution of the matrix ion. The proposed hyphenated system of CFSE and FlFFF/CFM with ICP-OES detection was examined for its reliability by checking with SRM 2710 (a highly contaminated soil from Montana). The metal contents determined by the proposed method were not significantly different (at 95% confidence) from the certified values.

  7. Hydrogen Isotope Fractionation during the Biodegradation of 1,2-Dichloroethane: Potential for Pathway Identification Using a Multi-element (C, Cl, and H) Isotope Approach.

    PubMed

    Palau, Jordi; Shouakar-Stash, Orfan; Hatijah Mortan, Siti; Yu, Rong; Rosell, Monica; Marco-Urrea, Ernest; Freedman, David L; Aravena, Ramon; Soler, Albert; Hunkeler, Daniel

    2017-09-19

    Even though multi-element isotope fractionation patterns provide crucial information with which to identify contaminant degradation pathways in the field, those involving hydrogen are still lacking for many halogenated groundwater contaminants and degradation pathways. This study investigates for the first time hydrogen isotope fractionation during both aerobic and anaerobic biodegradation of 1,2-dichloroethane (1,2-DCA) using five microbial cultures. Transformation-associated isotope fractionation values (εbulk(H)) were -115 ± 18‰ (aerobic C-H bond oxidation), -34 ± 4‰ and -38 ± 4‰ (aerobic C-Cl bond cleavage via hydrolytic dehalogenation), and -57 ± 3‰ and -77 ± 9‰ (anaerobic C-Cl bond cleavage via reductive dihaloelimination). The dual-element C-H isotope approach (ΛC-H = Δδ(2)H/Δδ(13)C ≈ εbulk(H)/εbulk(C), where Δδ(2)H and Δδ(13)C are changes in isotope ratios during degradation) resulted in clearly different ΛC-H values: 28 ± 4 (oxidation), 0.7 ± 0.1 and 0.9 ± 0.1 (hydrolytic dehalogenation), and 1.76 ± 0.05 and 3.5 ± 0.1 (dihaloelimination). This result highlights the potential of this approach to identify 1,2-DCA degradation pathways in the field. In addition, distinct trends were also observed in a multi- (i.e., Δδ(2)H versus Δδ(37)Cl versus Δδ(13)C) isotope plot, which opens further possibilities for pathway identification in future field studies. This is crucial information to understand the mechanisms controlling natural attenuation of 1,2-DCA and to design appropriate strategies to enhance biodegradation.

  8. Effects of a Flavonoid-Rich Fraction on the Acquisition and Extinction of Fear Memory: Pharmacological and Molecular Approaches

    PubMed Central

    de Oliveira, Daniela R.; Zamberlam, Claudia R.; Rêgo, Gizelda M.; Cavalheiro, Alberto; Cerutti, Janete M.; Cerutti, Suzete M.

    2016-01-01

    The effects of flavonoids have been correlated with their ability to modulate the glutamatergic, serotoninergic, and GABAergic neurotransmission; the major targets of these substances are N-methyl-D-aspartic acid receptor (NMDARs), serotonin type1A receptor (5-HT1ARs), and the gamma-aminobutyric acid type A receptors (GABAARs). Several studies showed that these receptors are involved in the acquisition and extinction of fear memory. This study assessed the effects of treatment prior to conditioning with a flavonoid-rich fraction from the stem bark of Erythrina falcata (FfB) on the acquisition and extinction of the conditioned suppression following pharmacological manipulations and on gene expression in the dorsal hippocampus (DH). Adult male Wistar rats were treated before conditioned fear with FfB, vehicle, an agonist or antagonist of the 5-HT1AR, GABAARs or the GluN2B-NMDAR or one of these antagonists before FfB treatment. The effects of these treatments on fear memory retrieval, extinction training and extinction retrieval were evaluated at 48, 72, and 98 h after conditioning, respectively. We found that activation of GABAARs and inactivation of GluN2B-NMDARs play important roles in the acquisition of lick response suppression. FfB reversed the effect of blocking GluN2B-NMDARs on the conditioned fear and induced the spontaneous recovery. Blocking the 5-HT1AR and the GluN2B-NMDAR before FfB treatment seemed to be associated with weakening of the spontaneous recovery. Expression of analysis of DH samples via qPCR showed that FfB treatment resulted in the overexpression of Htr1a, Grin2a, Gabra5, and Erk2 after the retention test and of Htr1a and Erk2 after the extinction retention test. Moreover, blocking the 5-HT1ARs and the GluN2B-NMDARs before FfB treatment resulted in reduced Htr1a and Grin2b expression after the retention test, but played a distinct role in Grin2a and Erk2 expression, according session evaluated. We show for the first time that the

  9. Effects of a Flavonoid-Rich Fraction on the Acquisition and Extinction of Fear Memory: Pharmacological and Molecular Approaches.

    PubMed

    de Oliveira, Daniela R; Zamberlam, Claudia R; Rêgo, Gizelda M; Cavalheiro, Alberto; Cerutti, Janete M; Cerutti, Suzete M

    2015-01-01

    The effects of flavonoids have been correlated with their ability to modulate the glutamatergic, serotoninergic, and GABAergic neurotransmission; the major targets of these substances are N-methyl-D-aspartic acid receptor (NMDARs), serotonin type1A receptor (5-HT1ARs), and the gamma-aminobutyric acid type A receptors (GABAARs). Several studies showed that these receptors are involved in the acquisition and extinction of fear memory. This study assessed the effects of treatment prior to conditioning with a flavonoid-rich fraction from the stem bark of Erythrina falcata (FfB) on the acquisition and extinction of the conditioned suppression following pharmacological manipulations and on gene expression in the dorsal hippocampus (DH). Adult male Wistar rats were treated before conditioned fear with FfB, vehicle, an agonist or antagonist of the 5-HT1AR, GABAARs or the GluN2B-NMDAR or one of these antagonists before FfB treatment. The effects of these treatments on fear memory retrieval, extinction training and extinction retrieval were evaluated at 48, 72, and 98 h after conditioning, respectively. We found that activation of GABAARs and inactivation of GluN2B-NMDARs play important roles in the acquisition of lick response suppression. FfB reversed the effect of blocking GluN2B-NMDARs on the conditioned fear and induced the spontaneous recovery. Blocking the 5-HT1AR and the GluN2B-NMDAR before FfB treatment seemed to be associated with weakening of the spontaneous recovery. Expression of analysis of DH samples via qPCR showed that FfB treatment resulted in the overexpression of Htr1a, Grin2a, Gabra5, and Erk2 after the retention test and of Htr1a and Erk2 after the extinction retention test. Moreover, blocking the 5-HT1ARs and the GluN2B-NMDARs before FfB treatment resulted in reduced Htr1a and Grin2b expression after the retention test, but played a distinct role in Grin2a and Erk2 expression, according session evaluated. We show for the first time that the

  10. Fractional distillation

    SciTech Connect

    Brand, M. J.; Callejas, R. J.

    1985-10-08

    Process and apparatus are provided for the recovery of low, medium and high boiling components from feed streams containing same wherein reboiler fouling, gumming and the like are minimized, via the control of fractionator reboiler temperatures.

  11. Fractionalize this

    SciTech Connect

    Phillips, Philip

    2010-12-01

    Precisely what are the electrons in a high-temperature superconductor doing before they superconduct? Strong electronic correlations may give rise to composite rather than fractionalized excitations, as is typical in other strongly coupled systems such as quark matter.

  12. Exceeding the filling fraction limit: An approach to enhancement of thermoelectric properties of filled - Co4Sb12 skutterudite

    NASA Astrophysics Data System (ADS)

    Graff, Jennifer Whitney

    Currently the world energy usage has nearly tripled since 1950 and is projected to grow at a rate of 1.5% per year and predicted to at least double from the beginning of the millennium to 2050. The United States alone is currently consuming more energy than it can produce (≈ 97 Quadrillion BTU's consumed in 2011).(1) Presently, fossil fuels make up over 85% of our energy landscape, including both the stationary grid (like coal and nuclear power plants) and the mobile grid (automobiles using gas and oil). This presents a major demand for developing methods of saving, storing, and renewing energy. Answers to these existing energy demands must come from a variety of renewable sources including: solar, wind, biomass, geothermal and others. But currently, most renewable sources are only a small part of the big energy picture. One approach to this exponentially growing problem, lies within high efficiency (15%-20%) thermoelectric (TE) materials which address small, yet very important and specific, parts of a bigger problem. Specifically, Co4Sb12-based skutterudites, an increasingly favorable thermoelectric material for mid to high temperature applications (currently used in General Motors TE Generator devices). These materials have the ability to be 'tuned' or controlled thermally and electrically through doping and filling mechanisms, as you will see in this dissertation. However, one of the major drawbacks of TE materials is the difficulty in optimizing both electrical and thermal properties simultaneously. Typically, different control parameters are used in order to enhance the electrical and thermal properties individually. It is very rare to observe optimization of both in a TE material via one control parameter. However, the work presented herein successfully augments all TE properties, with one control variable, by using an approach that can be applied to all doped skutterudites and clathrate materials. Skutterudites are novel materials in that they are a binary

  13. Species-specific responses of N homeostasis and electrolyte handling to low N intake: a comparative physiological approach in a monogastric and a ruminant species.

    PubMed

    Starke, S; Cox, C; Südekum, K-H; Huber, K

    2014-01-01

    In our former studies low crude protein (LCP) intake influenced N homeostasis and electrolyte handling in goats. We hypothesised that due to rumino-hepatic nitrogen (N) recycling adaptation of N homeostasis and adjustment of electrolyte handling to LCP intake differs between goats and monogastric animals. Therefore, an experiment similar to that with goats was conducted with rats. Two feeding groups received a diet either containing 20 or 8 % crude protein (as fed basis) for 5 weeks and intake and excretion of N, calcium (Ca) and phosphorus (P) were determined. To detect systemic and endocrine adaptation to LCP intake plasma concentrations of urea, Ca, phosphate (Pi), insulin-like growth factor 1 (IGF-1), 1,25-dihydroxyvitamin D3 (calcitriol), parathyroid hormone (PTH) and cross-linked telopeptide of type I collagen (CTX) were measured. Adjustment of renal electrolyte transport was assessed by detecting protein expression of key proteins of renal Pi transport. All data were compared with the data of the goat experiment. LCP intake decreased plasma urea concentration stronger in goats than in rats. In both species urinary N excretion declined, but faecal N excretion decreased in goats only. Furthermore, in goats urinary Ca excretion decreased, but in rats urinary Ca concentration increased. Decreased plasma IGF-1 and calcitriol concentrations were found in goats only. Thus, renal Ca excretion appears to be a common target in adaptation of electrolyte homeostasis in both species, but is regulated differently.

  14. Understanding Multiplication of Fractions.

    ERIC Educational Resources Information Center

    Sweetland, Robert D.

    1984-01-01

    Discussed the use of Cuisenaire rods in teaching the multiplication of fractions. Considers whole number times proper fraction, proper fraction multiplied by proper fraction, mixed number times proper fraction, and mixed fraction multiplied by mixed fractions. (JN)

  15. Merging high-quality biochemical fractionation with a refined flow cytometry approach to monitor nucleocytoplasmic protein expression throughout the unperturbed mammalian cell cycle.

    PubMed

    Rosner, Margit; Schipany, Katharina; Hengstschläger, Markus

    2013-03-01

    This protocol describes a method for nucleocytoplasmic protein tracking during normal cell cycle progression using unmanipulated, asynchronous cells. In contrast with prevalent traditional methods, our approach does not require time-consuming, perturbing cell synchronization or separation. To this end, we chose a single-cell approach and developed a flow cytometry assay that is applied to whole cells and isolated nuclei. Our protocol involves a stepwise biochemical fractionation procedure to purify nuclei from whole cells, conventional DNA and indirect immunostaining techniques for the dual labeling of cells and nuclei for DNA and protein, and a refined concept of flow cytometric data processing and calculation: through the specific combination of DNA and cell size analyses, G1, S and G2/M phases of the cell cycle are further dissected to establish a high-resolution map of cell cycle progression, to which protein expression in cells or nuclei is correlated. In a final data analysis step, cell cycle-related, cytoplasmic protein expression is calculated on the basis of results obtained for whole cells and isolated nuclei. A minimum of 8 h is required to complete the procedure. As the approach does not require cell type-restricting pretreatments, numerous cell types of different origin can be readily studied. Human amniotic fluid stem cells, primary human fibroblasts, immortalized mouse fibroblasts and transformed tumor cells are analyzed at comparable efficiencies, demonstrating low intercell assay variability.

  16. Dietary Intake, Changes in Lipid Parameters and the Risk of Hypertriglyceridemia: A Prospective Approach in the Tehran Lipid and Glucose Study.

    PubMed

    Mirmiran, Parvin; Bahadoran, Zahra; Mirzaei, Sahar; Azizi, Fereidoun

    2014-01-01

    This study assessed the association of dietary factors with 3-year changes in serum triglycerides (TG), HDL-C and the atherogenic index of plasma (AIP) among Iranian adults. This longitudinal study was conducted with 1938 adults. Demographics, anthropometrics and biochemical measurements, including serum (TG) and HDL-C and AIP, were assessed at baseline (2006 - 2008) and after a 3 year follow-up (2009 - 2011). Dietary data was collected using a validated food frequency questionnaire at baseline. The associations of dietary factors with 3-year changes in lipid parameters were evaluated using linear regression models and the incidence of hypertriglyceridemia after 3 years was assessed using logistic regression models with adjustment for potential confounders. The mean age of the participants at baseline was 41.0 ± 13.0 years. Dietary energy density was negatively associated with HDL-C and positively associated with AIP changes (P < 0.05). A three-year change of serum TG was inversely related to energy intake from phytochemical rich foods, whole grains, and legumes (P < 0.05). Fast food intake was positively related to serum TG and AIP changes. Higher compared to lower intakes of dietary fiber and phytochemical-rich foods had similar impacts on a decreased risk of hypertriglyceridemia (OR = 0.58, 95 % CI = 0.34 - 1.00). Higher - compared to lower - dietary sodium to potassium ratios (Na/K ratio) increased the risk of hypertriglyceridemia by 63 % (OR = 0.1.63, 95 % CI = 0.34 - 1.00). These findings suggested that more dense diets, and a higher intake of fast food and fat, could have undesirable effects on lipid and lipoprotein levels; in contrast, higher intakes of fiber, and phytochemical rich foods, especially whole grain and legumes, could have protective effects against undesirable changes in lipid and lipid profiles.

  17. Fractional market dynamics

    NASA Astrophysics Data System (ADS)

    Laskin, Nick

    2000-12-01

    A new extension of a fractality concept in financial mathematics has been developed. We have introduced a new fractional Langevin-type stochastic differential equation that differs from the standard Langevin equation: (i) by replacing the first-order derivative with respect to time by the fractional derivative of order μ; and (ii) by replacing “white noise” Gaussian stochastic force by the generalized “shot noise”, each pulse of which has a random amplitude with the α-stable Lévy distribution. As an application of the developed fractional non-Gaussian dynamical approach the expression for the probability distribution function (pdf) of the returns has been established. It is shown that the obtained fractional pdf fits well the central part and the tails of the empirical distribution of S&P 500 returns.

  18. Mystery Fractions

    ERIC Educational Resources Information Center

    Bhattacharyya, Sonalee; Namakshi, Nama; Zunker, Christina; Warshauer, Hiroko K.; Warshauer, Max

    2016-01-01

    Making math more engaging for students is a challenge that every teacher faces on a daily basis. These authors write that they are constantly searching for rich problem-solving tasks that cover the necessary content, develop critical-thinking skills, and engage student interest. The Mystery Fraction activity provided here focuses on a key number…

  19. Mystery Fractions

    ERIC Educational Resources Information Center

    Bhattacharyya, Sonalee; Namakshi, Nama; Zunker, Christina; Warshauer, Hiroko K.; Warshauer, Max

    2016-01-01

    Making math more engaging for students is a challenge that every teacher faces on a daily basis. These authors write that they are constantly searching for rich problem-solving tasks that cover the necessary content, develop critical-thinking skills, and engage student interest. The Mystery Fraction activity provided here focuses on a key number…

  20. Pitch Fractionation.

    DTIC Science & Technology

    1981-12-15

    13 3. Solvent Fractionation Experiments .................................... 15 4. Fourier Transform Infrared Spectra for A240 Petrolem Pitch AG 12...34 and Mesophase Pitch AG 164B ............................... 21 5. Fourier Transform Infrared Spectra ................................... 23 6...compared by Fourier transform infrared (FTIR) analysis using a Digilab Model FTS 14 spectrophotometer (Rockwell International, Anaheim, California

  1. Fractional magnetization plateaus of the spin-1/2 Heisenberg orthogonal-dimer chain: Strong-coupling approach developed from the exactly solved Ising-Heisenberg model

    NASA Astrophysics Data System (ADS)

    Verkholyak, Taras; Strečka, Jozef

    2016-10-01

    The spin-1/2 Heisenberg orthogonal-dimer chain is considered within the perturbative strong-coupling approach, which is developed from the exactly solved spin-1/2 Ising-Heisenberg orthogonal-dimer chain with the Heisenberg intradimer and the Ising interdimer couplings. Although the spin-1/2 Ising-Heisenberg orthogonal-dimer chain exhibits just intermediate plateaus at zero, one-quarter, and one-half of the saturation magnetization, the perturbative treatment up to second order stemming from this exactly solvable model additionally corroborates the fractional one-third plateau as well as the gapless Luttinger spin-liquid phase. It is evidenced that the approximate results obtained from the strong-coupling approach are in an excellent agreement with the state-of-the-art numerical data obtained for the spin-1/2 Heisenberg orthogonal-dimer chain within the exact diagonalization and density-matrix renormalization group method. The nature of individual quantum ground states is comprehensively studied within the developed perturbation theory.

  2. Fractional calculus in bioengineering.

    PubMed

    Magin, Richard L

    2004-01-01

    Fractional calculus (integral and differential operations of noninteger order) is not often used to model biological systems. Although the basic mathematical ideas were developed long ago by the mathematicians Leibniz (1695), Liouville (1834), Riemann (1892), and others and brought to the attention of the engineering world by Oliver Heaviside in the 1890s, it was not until 1974 that the first book on the topic was published by Oldham and Spanier. Recent monographs and symposia proceedings have highlighted the application of fractional calculus in physics, continuum mechanics, signal processing, and electromagnetics, but with few examples of applications in bioengineering. This is surprising because the methods of fractional calculus, when defined as a Laplace or Fourier convolution product, are suitable for solving many problems in biomedical research. For example, early studies by Cole (1933) and Hodgkin (1946) of the electrical properties of nerve cell membranes and the propagation of electrical signals are well characterized by differential equations of fractional order. The solution involves a generalization of the exponential function to the Mittag-Leffler function, which provides a better fit to the observed cell membrane data. A parallel application of fractional derivatives to viscoelastic materials establishes, in a natural way, hereditary integrals and the power law (Nutting/Scott Blair) stress-strain relationship for modeling biomaterials. In this review, I will introduce the idea of fractional operations by following the original approach of Heaviside, demonstrate the basic operations of fractional calculus on well-behaved functions (step, ramp, pulse, sinusoid) of engineering interest, and give specific examples from electrochemistry, physics, bioengineering, and biophysics. The fractional derivative accurately describes natural phenomena that occur in such common engineering problems as heat transfer, electrode/electrolyte behavior, and sub

  3. Simulation-Based Stochastic Sensitivity Analysis of a Mach 4.5 Mixed-Compression Intake Performance

    NASA Astrophysics Data System (ADS)

    Kato, H.; Ito, K.

    2009-01-01

    A sensitivity analysis of a supersonic mixed-compression intake of a variable-cycle turbine-based combined cycle (TBCC) engine is presented. The TBCC engine is de- signed to power a long-range Mach 4.5 transport capable of antipodal missions studied in the framework of an EU FP6 project, LAPCAT. The nominal intake geometry was designed using DLR abpi cycle analysis pro- gram by taking into account various operating require- ments of a typical mission profile. The intake consists of two movable external compression ramps followed by an isolator section with bleed channel. The compressed air is then diffused through a rectangular-to-circular subsonic diffuser. A multi-block Reynolds-averaged Navier- Stokes (RANS) solver with Srinivasan-Tannehill equilibrium air model was used to compute the total pressure recovery and mass capture fraction. While RANS simulation of the nominal intake configuration provides more realistic performance characteristics of the intake than the cycle analysis program, the intake design must also take into account in-flight uncertainties for robust intake performance. In this study, we focus on the effects of the geometric uncertainties on pressure recovery and mass capture fraction, and propose a practical approach to simulation-based sensitivity analysis. The method begins by constructing a light-weight analytical model, a radial-basis function (RBF) network, trained via adaptively sampled RANS simulation results. Using the RBF network as the response surface approximation, stochastic sensitivity analysis is performed using analysis of variance (ANOVA) technique by Sobol. This approach makes it possible to perform a generalized multi-input- multi-output sensitivity analysis based on high-fidelity RANS simulation. The resulting Sobol's influence indices allow the engineer to identify dominant parameters as well as the degree of interaction among multiple parameters, which can then be fed back into the design cycle.

  4. Multi-site study of additive genetic effects on fractional anisotropy of cerebral white matter: Comparing meta and megaanalytical approaches for data pooling.

    PubMed

    Kochunov, Peter; Jahanshad, Neda; Sprooten, Emma; Nichols, Thomas E; Mandl, René C; Almasy, Laura; Booth, Tom; Brouwer, Rachel M; Curran, Joanne E; de Zubicaray, Greig I; Dimitrova, Rali; Duggirala, Ravi; Fox, Peter T; Hong, L Elliot; Landman, Bennett A; Lemaitre, Hervé; Lopez, Lorna M; Martin, Nicholas G; McMahon, Katie L; Mitchell, Braxton D; Olvera, Rene L; Peterson, Charles P; Starr, John M; Sussmann, Jessika E; Toga, Arthur W; Wardlaw, Joanna M; Wright, Margaret J; Wright, Susan N; Bastin, Mark E; McIntosh, Andrew M; Boomsma, Dorret I; Kahn, René S; den Braber, Anouk; de Geus, Eco J C; Deary, Ian J; Hulshoff Pol, Hilleke E; Williamson, Douglas E; Blangero, John; van 't Ent, Dennis; Thompson, Paul M; Glahn, David C

    2014-07-15

    Combining datasets across independent studies can boost statistical power by increasing the numbers of observations and can achieve more accurate estimates of effect sizes. This is especially important for genetic studies where a large number of observations are required to obtain sufficient power to detect and replicate genetic effects. There is a need to develop and evaluate methods for joint-analytical analyses of rich datasets collected in imaging genetics studies. The ENIGMA-DTI consortium is developing and evaluating approaches for obtaining pooled estimates of heritability through meta-and mega-genetic analytical approaches, to estimate the general additive genetic contributions to the intersubject variance in fractional anisotropy (FA) measured from diffusion tensor imaging (DTI). We used the ENIGMA-DTI data harmonization protocol for uniform processing of DTI data from multiple sites. We evaluated this protocol in five family-based cohorts providing data from a total of 2248 children and adults (ages: 9-85) collected with various imaging protocols. We used the imaging genetics analysis tool, SOLAR-Eclipse, to combine twin and family data from Dutch, Australian and Mexican-American cohorts into one large "mega-family". We showed that heritability estimates may vary from one cohort to another. We used two meta-analytical (the sample-size and standard-error weighted) approaches and a mega-genetic analysis to calculate heritability estimates across-population. We performed leave-one-out analysis of the joint estimates of heritability, removing a different cohort each time to understand the estimate variability. Overall, meta- and mega-genetic analyses of heritability produced robust estimates of heritability.

  5. Fractional Hopfield Neural Networks: Fractional Dynamic Associative Recurrent Neural Networks.

    PubMed

    Pu, Yi-Fei; Yi, Zhang; Zhou, Ji-Liu

    2017-10-01

    This paper mainly discusses a novel conceptual framework: fractional Hopfield neural networks (FHNN). As is commonly known, fractional calculus has been incorporated into artificial neural networks, mainly because of its long-term memory and nonlocality. Some researchers have made interesting attempts at fractional neural networks and gained competitive advantages over integer-order neural networks. Therefore, it is naturally makes one ponder how to generalize the first-order Hopfield neural networks to the fractional-order ones, and how to implement FHNN by means of fractional calculus. We propose to introduce a novel mathematical method: fractional calculus to implement FHNN. First, we implement fractor in the form of an analog circuit. Second, we implement FHNN by utilizing fractor and the fractional steepest descent approach, construct its Lyapunov function, and further analyze its attractors. Third, we perform experiments to analyze the stability and convergence of FHNN, and further discuss its applications to the defense against chip cloning attacks for anticounterfeiting. The main contribution of our work is to propose FHNN in the form of an analog circuit by utilizing a fractor and the fractional steepest descent approach, construct its Lyapunov function, prove its Lyapunov stability, analyze its attractors, and apply FHNN to the defense against chip cloning attacks for anticounterfeiting. A significant advantage of FHNN is that its attractors essentially relate to the neuron's fractional order. FHNN possesses the fractional-order-stability and fractional-order-sensitivity characteristics.

  6. Fraction Reduction through Continued Fractions

    ERIC Educational Resources Information Center

    Carley, Holly

    2011-01-01

    This article presents a method of reducing fractions without factoring. The ideas presented may be useful as a project for motivated students in an undergraduate number theory course. The discussion is related to the Euclidean Algorithm and its variations may lead to projects or early examples involving efficiency of an algorithm.

  7. Fraction Reduction through Continued Fractions

    ERIC Educational Resources Information Center

    Carley, Holly

    2011-01-01

    This article presents a method of reducing fractions without factoring. The ideas presented may be useful as a project for motivated students in an undergraduate number theory course. The discussion is related to the Euclidean Algorithm and its variations may lead to projects or early examples involving efficiency of an algorithm.

  8. Isotope fractionation

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    A rash of new controversy has emerged around the subject of mass-independent isotope fractionation effects, particularly in the case of the oxygen isotopes. To be sure, the controversy has been around for awhile, but it has been given new impetus by the results of a recent study by Mark H. Thiemens and John E. Heidenreich III of the University of California, San Diego (Science, March 4, 1983).Gustav Arrhenius has been trying to convince the planetary science community that chemical effects in isotope fractionation processes could explain observations in meteorites that appear to be outside of the traditionally understood mass-dependent fractionations (G. Arrhenius, J . L. McCrumb, and N. F. Friedman, Astrophys. Space Sci, 65, 297, 1974). Robert Clayton had made the basic observations of oxygen in carbonaceous chondrites that the slope of the δ17 versus δ18 line was 1 instead of the slope of ½ characteristic of terrestrial rocks and lunar samples (Ann. Rev. Nucl. Part. Sci., 28, 501, 1978). The mass-independent effects were ascribed to the apparent contribution of an ancient presolar system component of O16.

  9. Carbohydrate intake, obesity, metabolic syndrome and cancer risk? A two-part systematic review and meta-analysis protocol to estimate attributability

    PubMed Central

    Sartorius, B; Sartorius, K; Aldous, C; Madiba, T E; Stefan, C; Noakes, T

    2016-01-01

    Introduction Linkages between carbohydrates, obesity and cancer continue to demonstrate conflicting results. Evidence suggests inconclusive direct linkages between carbohydrates and specific cancers. Conversely, obesity has been strongly linked to a wide range of cancers. The purpose of the study is to explore linkages between carbohydrate intake and cancer types using a two-step approach. First the study will evaluate the linkages between carbohydrate intake and obesity, potentially stratified by metabolic syndrome status. Second, the estimated attributable fraction of obesity ascribed to carbohydrate intake will be multiplied against obesity attributable fractions for cancer types to give estimated overall attributable fraction for carbohydrate versus cancer type. Methods and analysis We will perform a comprehensive search to identify all possible published and unpublished studies that have assessed risk factors for obesity including dietary carbohydrate intake. Scientific databases, namely PubMed MEDLINE, EMBASE, EBSCOhost and ISI Web of Science will be searched. Following study selection, paper/data acquisition, and data extraction and synthesis, we will appraise the quality of studies and risk of bias, as well as assess heterogeneity. Meta-weighted attributable fractions of obesity due to carbohydrate intake will be estimated after adjusting for other potential confounding factors (eg, physical inactivity, other dietary intake). Furthermore, previously published systematic reviews assessing the cancer-specific risk associated with obesity will also be drawn. These estimates will be linked with the attributability of carbohydrate intake in part 1 to estimate the cancer-specific burden that can be attributed to dietary carbohydrates. This systematic review protocol has been developed according to the ‘Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) 2015’. Ethics and dissemination The current study will be based on

  10. Cooling Water Intakes

    EPA Pesticide Factsheets

    Industries use large volumes of water for cooling. The water intakes pull large numbers of fish and other organisms into the cooling systems. EPA issues regulations on intake structures in order to minimize adverse environmental impacts.

  11. West Closure Complex Pump Intake Model, New Orleans, Louisiana

    DTIC Science & Technology

    2013-02-01

    Abstract The WCC pump station intake was evaluated for intake performance using a 1: 20 -scale model of the approach channel, intake bays, contracted... 20   Figure 15. Top view of contracted section and FSI in original design... 20   Figure 16. Model trash rack

  12. Dietary Intake of Competitive Bodybuilders.

    PubMed

    Spendlove, Jessica; Mitchell, Lachlan; Gifford, Janelle; Hackett, Daniel; Slater, Gary; Cobley, Stephen; O'Connor, Helen

    2015-07-01

    Competitive bodybuilders are well known for extreme physique traits and extremes in diet and training manipulation to optimize lean mass and achieve a low body fat. Although many of the dietary dogmas in bodybuilding lack scientific scrutiny, a number, including timing and dosing of high biological value proteins across the day, have more recently been confirmed as effective by empirical research studies. A more comprehensive understanding of the dietary intakes of bodybuilders has the potential to uncover other dietary approaches, deserving of scientific investigation, with application to the wider sporting, and potential health contexts, where manipulation of physique traits is desired. Our objective was to conduct a systematic review of dietary intake practices of competitive bodybuilders, evaluate the quality and currency of the existing literature, and identify research gaps to inform future studies. A systematic search of electronic databases was conducted from the earliest record until March 2014. The search combined permutations of the terms 'bodybuilding', 'dietary intake', and 'dietary supplement'. Included studies needed to report quantitative data (energy and macronutrients at a minimum) on habitual dietary intake of competitive bodybuilders. The 18 manuscripts meeting eligibility criteria reported on 385 participants (n = 62 women). Most studies were published in the 1980-1990s, with three published in the past 5 years. Study methodological quality was evaluated as poor. Energy intake ranged from 10 to 24 MJ/day for men and from 4 to 14 MJ/day for women. Protein intake ranged from 1.9 to 4.3 g/kg for men and from 0.8 to 2.8 g/kg for women. Intake of carbohydrate and fat was <6 g/kg/day and below 30% of energy, respectively. Carbohydrate intakes were below, and protein (in men) intakes were higher than, the current recommendations for strength athletes, with no consideration for exploration of macronutrient quality or distribution over the day. Energy

  13. An increase of cereal intake as an approach to weight reduction in children is effective only when accompanied by nutrition education: a randomized controlled trial

    PubMed Central

    Rosado, Jorge L; del R Arellano, María; Montemayor, Karina; García, Olga P; Caamaño, María del C

    2008-01-01

    Background The main emphasis of dietary advice for control of obesity has been on reducing dietary fat. Increasing ready to eat cereal (RTEC) consumption could be a strategy to reduce fat intake and increase carbohydrate intake resulting in a diet with lower energy density. Objectives 1. To determine if an increase in RTEC intake is an effective strategy to reduce excess body weight and blood lipids in overweight or at risk of overweight children. 2. To determine if a nutrition education program would make a difference on the response to an increase in cereal intake. 3) To determine if increase in RTEC intake alone or with a nutrition education program has an effect on plasma lipid profile. Experimental design One hundred and forty seven overweight or at risk of overweight children (6–12 y of age) were assigned to one of four different treatments: a. One serving of 33 ± 7 g of RTEC for breakfast; b. one serving of 33 ± 7 g of RTEC for breakfast and another one for dinner; c. one serving of 33 ± 7 g of RTEC for breakfast and a nutrition education program. d. Non intervention, control group. Anthropometry, body composition, physical activity and blood lipids were measured at baseline, before treatments, and 12 weeks after treatments. Results After 12 weeks of intervention only the children that received 33 ± 7 g of RTEC and nutrition education had significantly lower body weight [-1.01 (-1.69, -0.34) ], p < 0.01], lower BMI [-0.95 (-1.71, -0.20), p < 0.01] and lower total body fat [-0.71 (-1.71, 0.28), p < 0.05] compared with the control group [1.19 (0.39, 1.98), 0.01 (-0.38, 0.41), 0.44 (-0.46, 1.35) respectively]. Plasma triglycerides and VLDL were significantly reduced [-20.74 (-36.44, -5.05), -3.78 (-6.91, -0.64) respectively, p < 0.05] and HDL increased significantly [6.61 (2.15, 11.08), p < 0.01] only in this treatment group. The groups that received 1 or 2 doses of RTEC alone were not significantly different to the control group. Conclusion A strategy to

  14. Fractional order model reduction approach based on retention of the dominant dynamics: application in IMC based tuning of FOPI and FOPID controllers.

    PubMed

    Tavakoli-Kakhki, Mahsan; Haeri, Mohammad

    2011-07-01

    Fractional order PI and PID controllers are the most common fractional order controllers used in practice. In this paper, a simple analytical method is proposed for tuning the parameters of these controllers. The proposed method is useful in designing fractional order PI and PID controllers for control of complicated fractional order systems. To achieve the goal, at first a reduction technique is presented for approximating complicated fractional order models. Then, based on the obtained reduced models some analytical rules are suggested to determine the parameters of fractional order PI and PID controllers. Finally, numerical results are given to show the efficiency of the proposed tuning algorithm. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  15. Agglomeration behaviour of titanium dioxide nanoparticles in river waters: A multi-method approach combining light scattering and field-flow fractionation techniques.

    PubMed

    Chekli, L; Roy, M; Tijing, L D; Donner, E; Lombi, E; Shon, H K

    2015-08-15

    Titanium dioxide nanoparticles (TiO2 NPs) are currently one of the most prolifically used nanomaterials, resulting in an increasing likelihood of release to the environment. This is of concern as the potential toxicity of TiO2 NPs has been investigated in several recent studies. Research into their fate and behaviour once entering the environment is urgently needed to support risk assessment and policy development. In this study, we used a multi-method approach combining light scattering and field-flow fractionation techniques to assess both the aggregation behaviour and aggregate structure of TiO2 NPs in different river waters. Results showed that both the aggregate size and surface-adsorbed dissolved organic matter (DOM) were strongly related to the initial DOM concentration of the tested waters (i.e. R(2) > 0.90) suggesting that aggregation of TiO2 NPs is controlled by the presence and concentration of DOM. The conformation of the formed aggregates was also found to be strongly related to the surface-adsorbed DOM (i.e. R(2) > 0.95) with increasing surface-adsorbed DOM leading to more compact structures. Finally, the concentration of TiO2 NPs remaining in the supernatant after sedimentation of the larger aggregates was found to decrease proportionally with both increasing IS and decreasing DOM concentration, resulting in more than 95% sedimentation in the highest IS sample.

  16. Exposure assessment of adult intake of bisphenol A (BPA) with emphasis on canned food dietary exposures.

    PubMed

    Lorber, Matthew; Schecter, Arnold; Paepke, Olaf; Shropshire, William; Christensen, Krista; Birnbaum, Linda

    2015-04-01

    Bisphenol A (BPA) is a high-volume, synthetic compound found in epoxy resins and plastics used in food packaging. Food is believed to be a major source of BPA intake. In this study, we measured the concentration of BPA in convenience samplings of foodstuffs purchased in Dallas, Texas. Sampling entailed collection of 204 samples of fresh, frozen, and canned foods in two rounds in 2010. BPA was positive in 73% of the canned food samples, while it was found in only 7% of non-canned foods at low concentrations. The results of this food sampling program were used to calculate adult dietary intakes of BPA. A pathway approach combined food intakes, a "canned fraction" parameter which described what portion of total intake of that food came from canned products, and measured food concentrations. Dietary intakes were calculated as 12.6 ng/kg-day, of which 12.4 ng/kg-day was from canned foods. Canned vegetable intakes alone were 11.9 ng/kg-day. This dietary intake was compared to total intakes of BPA estimated from urine measurements of the National Health and Nutrition Examination Survey (NHANES). Total adult central tendency intakes ranged from 30 to 70 ng/kg-day for NHANES cycles between 2005 and 2010. Three possibilities were explored to explain the difference between these two approaches for intake estimation. Not all foods which may have been canned, particularly canned beverages such as soft drinks, were sampled in our food sampling program. Second, non-food pathways of exposure may be important for adults, including thermal paper exposures, and dust and air exposures. Finally, our canned food concentrations may not be adequately representative of canned foods in the United States; they were found to be generally lower compared to canned food concentrations measured in six other worldwide food surveys including three in North America. Our finding that canned food concentrations greatly exceeded non-canned concentrations was consistent with other studies, and

  17. Contribution of maternal radionuclide burdens to prenatal radiation doses: Relationships between annual limits on intake and prenatal doses. Revision 1, Addendum 1

    SciTech Connect

    Sikov, M.R.; Hui, T.E.

    1993-10-01

    This addendum describes approaches for calculating and expressing radiation doses to the embryo/fetus from maternal intakes of radionuclides at levels corresponding to fractions or multiples of the Annual Limits on Intake (ALI). Information, concerning metabolic or dosimetric characteristics and the placental transfer of selected, occupationally significant radionuclides was presented in NUREG/CR-5631, Revision 1. That information was used to estimate levels of radioactivity in the embryo/fetus as a function of stage of pregnancy and time after entry. Extension of MIRD methodology to accommodate gestational-stage-dependent characteristics allowed dose calculations for the simplified situation based on introduction of 1 {mu}Ci into the woman`s transfer compartment (blood). The expanded scenarios in this addendum include repeated or chronic ingestion or inhalation intakes by a woman during pregnancy and body burdens at the beginning of pregnancy. Tables present dose equivalent to the embryo/fetus relative to intakes of these radionuclides in various chemical or physical forms and from preexisting maternal burdens corresponding to ALI; complementary intake values (fraction of an ALI and {mu}Ci) that yield a dose equivalent of 0.05 rem are included. Similar tables give these measures of dose equivalency to the uterus from intakes of radionuclides for use as surrogates for embryo/fetus dose when biokinetic information is not available.

  18. Personalized State-space Modeling of Glucose Dynamics for Type 1 Diabetes Using Continuously Monitored Glucose, Insulin Dose, and Meal Intake: An Extended Kalman Filter Approach.

    PubMed

    Wang, Qian; Molenaar, Peter; Harsh, Saurabh; Freeman, Kenneth; Xie, Jinyu; Gold, Carol; Rovine, Mike; Ulbrecht, Jan

    2014-03-01

    An essential component of any artificial pancreas is on the prediction of blood glucose levels as a function of exogenous and endogenous perturbations such as insulin dose, meal intake, and physical activity and emotional tone under natural living conditions. In this article, we present a new data-driven state-space dynamic model with time-varying coefficients that are used to explicitly quantify the time-varying patient-specific effects of insulin dose and meal intake on blood glucose fluctuations. Using the 3-variate time series of glucose level, insulin dose, and meal intake of an individual type 1 diabetic subject, we apply an extended Kalman filter (EKF) to estimate time-varying coefficients of the patient-specific state-space model. We evaluate our empirical modeling using (1) the FDA-approved UVa/Padova simulator with 30 virtual patients and (2) clinical data of 5 type 1 diabetic patients under natural living conditions. Compared to a forgetting-factor-based recursive ARX model of the same order, the EKF model predictions have higher fit, and significantly better temporal gain and J index and thus are superior in early detection of upward and downward trends in glucose. The EKF based state-space model developed in this article is particularly suitable for model-based state-feedback control designs since the Kalman filter estimates the state variable of the glucose dynamics based on the measured glucose time series. In addition, since the model parameters are estimated in real time, this model is also suitable for adaptive control.

  19. Systematic review on daily vitamin B12 losses and bioavailability for deriving recommendations on vitamin B12 intake with the factorial approach.

    PubMed

    Doets, Esmée L; In 't Veld, Paulette H; Szczecińska, Anna; Dhonukshe-Rutten, Rosalie A M; Cavelaars, Adrienne E J M; van 't Veer, Pieter; Brzozowska, Anna; de Groot, Lisette C P G M

    2013-01-01

    To systematically review the literature on daily losses and bioavailability of vitamin B12. These estimates could be used for deriving recommendations on vitamin B12 intake for adults and elderly. We identified publications on daily vitamin B12 losses (July 2011) and publications on the bioavailability of vitamin B12 from foods or diets (June 2010) in MEDLINE, EMBASE and the Cochrane Library. A pooled analysis of five studies (52 subjects) showed that 0.13 ± 0.03% of the total body store is lost per day. Absorption of vitamin B12 ranged from 4.5 (dose of 38 µg from consumption of liver) to 83% (dose of 3.0 µg from consumption of mutton meat). Data from eight studies including 83 subjects suggested that the amount of vitamin B12 absorbed from food (Ai) increased with increasing doses of vitamin B12 (Di) as described by the equation: ln(Ai) = 0.7694 * ln(Di) - 0.9614. Daily vitamin B12 losses in apparently healthy adults and elderly probably range from 1.4 to 5.1 µg. Vitamin B12 intakes needed to compensate for these losses seem to range from 3.8 to 20.7 µg. More evidence is needed on the relationships between biochemical markers of vitamin B12 status, vitamin B12 body store and long-term health outcomes to evaluate whether current recommendations on vitamin B12 intake (1.4-3 µg) need to be changed. Copyright © 2013 S. Karger AG, Basel.

  20. Saturated fats: what dietary intake?

    PubMed

    German, J Bruce; Dillard, Cora J

    2004-09-01

    Public health recommendations for the US population in 1977 were to reduce fat intake to as low as 30% of calories to lower the incidence of coronary artery disease. These recommendations resulted in a compositional shift in food materials throughout the agricultural industry, and the fractional content of fats was replaced principally with carbohydrates. Subsequently, high-carbohydrate diets were recognized as contributing to the lipoprotein pattern that characterizes atherogenic dyslipidemia and hypertriacylglycerolemia. The rising incidences of metabolic syndrome and obesity are becoming common themes in the literature. Current recommendations are to keep saturated fatty acid, trans fatty acid, and cholesterol intakes as low as possible while consuming a nutritionally adequate diet. In the face of such recommendations, the agricultural industry is shifting food composition toward lower proportions of all saturated fatty acids. To date, no lower safe limit of specific saturated fatty acid intakes has been identified. This review summarizes research findings and observations on the disparate functions of saturated fatty acids and seeks to bring a more quantitative balance to the debate on dietary saturated fat. Whether a finite quantity of specific dietary saturated fatty acids actually benefits health is not yet known. Because agricultural practices to reduce saturated fat will require a prolonged and concerted effort, and because the world is moving toward more individualized dietary recommendations, should the steps to decrease saturated fatty acids to as low as agriculturally possible not wait until evidence clearly indicates which amounts and types of saturated fatty acids are optimal?

  1. Low-sodium dietary approaches to stop hypertension diet reduces blood pressure, arterial stiffness, and oxidative stress in hypertensive heart failure with preserved ejection fraction.

    PubMed

    Hummel, Scott L; Seymour, E Mitchell; Brook, Robert D; Kolias, Theodore J; Sheth, Samar S; Rosenblum, Hannah R; Wells, Joanna M; Weder, Alan B

    2012-11-01

    Recent studies suggest that oxidative stress and vascular dysfunction contribute to heart failure with preserved ejection fraction (HFPEF). In salt-sensitive HFPEF animal models, diets low in sodium and high in potassium, calcium, magnesium, and antioxidants attenuate oxidative stress and cardiovascular damage. We hypothesized that the sodium-restricted Dietary Approaches to Stop Hypertension diet (DASH/SRD) would have similar effects in human hypertensive HFPEF. Thirteen patients with treated hypertension and compensated HFPEF consumed the DASH/SRD for 21 days (all food/most beverages provided). The DASH/SRD reduced clinic systolic (155-138 mm Hg; P=0.02) and diastolic blood pressure (79-72 mm Hg; P=0.04), 24-hour ambulatory systolic (130-123 mm Hg; P=0.02) and diastolic blood pressure (67-62 mm Hg; P=0.02), and carotid-femoral pulse wave velocity (12.4-11.0 m/s; P=0.03). Urinary F2-isoprostanes decreased by 31% (209-144 pmol/mmol Cr; P=0.02) despite increased urinary aldosterone excretion. The reduction in urinary F2-isoprostanes closely correlated with the reduction in urinary sodium excretion on the DASH/SRD. In this cohort of HFPEF patients with treated hypertension, the DASH/SRD reduced systemic blood pressure, arterial stiffness, and oxidative stress. These findings are characteristic of salt-sensitive hypertension, a phenotype present in many HFPEF animal models and suggest shared pathophysiological mechanisms linking these 2 conditions. Further dietary modification studies could provide insights into the development and progression of hypertensive HFPEF.

  2. Effect of surfactant on retention behaviors of polystyrene latex particles in sedimentation field-flow fractionation: effective boundary slip model approach.

    PubMed

    Kim, Sun Tae; Rah, Kyunil; Lee, Seungho

    2012-07-24

    A retention theory in sedimentation field-flow fractionation (SdFFF) was developed by exploiting the effective slip boundary condition (BC) that allows a finite velocity for particles to have at the wall, thereby alleviating the limitations set by the no-slip BC constraint bound to the standard retention theory (SRT). This led to an expression for the retention ratio R as R = (R(o) + v*(b))/(R(o) + v*(b)), where R(o) is the sterically corrected SRT retention ratio and v*(b) is the reduced boundary velocity. Then, v*(b) was modeled as v*(b) = v*(b,o)/[1 + (7K*S(o))(1/2)], where S(o) is the surfactant (FL-70) concentration and K* is the distribution coefficient associated with the langmuirian isotherm of the apparent effective mass against S(o). We applied this to study the surfactant effect on the retention behaviors of polystyrene (PS) latex beads of 170-500 nm in diameter. As a result, an empirical relation was found to hold between v*(b,o) and d(o) (estimated from R(o) at S(o) = 0) as v*(b,o) - v*(o,o)[1 - (d(c)/d(o))], where v*(o,o) is the asymptotic value of v*(b,o) in the vanishing d(c)/d(o) limit and d(c) is the cutoff value at which v*(b,o) would vanish. According to the present approach, the no-slip BC (v*(b,o) = 0) was predicted to recover when d(o) ∼ d(c), and the boundary slip effect could be significant for S(o) ≤ 0.05%, particularly for large latex beads.

  3. Development of a low-cost, high-throughput native polyacrylamide gel electrophoresis (N-PAGE) protocol for lipoprotein sub-fractionation using Quality by Design approach.

    PubMed

    Pathak, Mili; Chaudhary, Neha; Rathore, Anurag S

    2014-04-01

    Ratio of low density to high density lipoprotein concentration is critical for normal functioning of human body. Deviation in this ratio has been linked to various diseases, many of which are fatal if not diagnosed at early stages. For example, cardiovascular diseases (CVD) have been linked to the level of low density lipoprotein (LDL). Henceforth, detection of the lipoprotein subtractions is crucial for health of an individual. To date, methods like ultracentrifugation, nuclear magnetic resonance (NMR), high performance liquid chromatography (HPLC) and gradient gel electrophoresis (GGE) have been used for separation and identification of lipoprotein types and subtypes. However, these methods are expensive, time consuming and require specialized equipments and expertise. This paper aims to propose a low-cost, high-throughput native polyacrylamide gel electrophoresis (N-PAGE) based protocol for analysis of lipoproteins. Quality by Design (QbD) based approach has been utilized. The initial screening of parameters was followed by a fractional factorial design to optimize the protocol. The lipoprotein subtractions obtained by the optimized protocol were compared with the commercially available and commonly used Lipoprint(®) Lipoprotein Subfractions Testing System from Quantimetrix. The proposed method gave comparable results to those obtained with the commercial system. The proposed method is capable of analysis of up to forty different samples in two hours at a cost of approximately 2$/sample. This is an order of magnitude better than the present cost of 265$/sample when using the commercial system. We think that the proposed method would be of particular interest to the developing and under-developed economies of the world, where this cost differential would be deemed quite significant and would make testing affordable to the majority of the population.

  4. Application of the Accurate Mass and Time Tag Approach to the Proteome Analysis of Sub-cellular Fractions Obtained from Rhodobacter sphaeroides 2.4.1 Aerobic and Photosynthetic Cell Cultures

    SciTech Connect

    Callister, Stephen J.; Dominguez, Migual; Nicora, Carrie D.; Zeng, Xiaohua; Tavano, Christine; Kaplan, Samuel; Donohue, Timothy; Smith, Richard D.; Lipton, Mary S.

    2006-08-04

    Abstract The high-throughput accurate mass and time tag (AMT) proteomic approach was utilized to characterize the proteomes for cytoplasm, cytoplasmic membrane, periplasm, and outer membrane fractions from aerobic and photosynthetic cultures of the gram-nagtive bacterium Rhodobacter sphaeroides 2.4.1. In addition, we analyzed the proteins within purified chromatophore fractions that house the photosynthetic apparatus from photosynthetically grown cells. In total, 8300 peptides were identified with high confidence from at least one sub-cellular fraction from either cell culture. These peptides were derived from 1514 genes or 35% percent of proteins predicted to be encoded by the genome. A significant number of these proteins were detected within a single sub-cellular fraction and their localization was compared to in-silico predictions. However, the majority of proteins were observed in multiple sub-cellular fractions, and the most likely sub-cellular localization for these proteins was investigated using a Z-score analysis of peptide abundance along with clustering techniques. Good (81%) agreement was observed between the experimental results and in-silico predictions. The AMT tag approach provides localization evidence for those proteins that have no predicted localization information, those annotated as putative proteins, and/or for those proteins annotated as hypothetical and conserved hypothetical.

  5. Application of the Accurate Mass and Time Tag Approach to the Proteome Analysis of Sub-cellular Fractions Obtained from Rhodobacter sphaeroides 2.4.1. Aerobic and Photosynthetic Cell Cultures

    PubMed Central

    Callister, Stephen J.; Dominguez, Miguel A.; Nicora, Carrie D.; Zeng, Xiaohua; Tavano, Christine L.; Kaplan, Samuel; Donohue, Timothy J.; Smith, Richard D.; Lipton, Mary S.

    2009-01-01

    The high-throughput accurate mass and time (AMT) tag proteomic approach was utilized to characterize the proteomes for cytoplasm, cytoplasmic membrane, periplasm, and outer membrane fractions from aerobic and photosynthetic cultures of the gram-nagtive bacterium Rhodobacter sphaeroides 2.4.1. In addition, we analyzed the proteins within purified chromatophore fractions that house the photosynthetic apparatus from photosynthetically grown cells. In total, 8300 peptides were identified with high confidence from at least one subcellular fraction from either cell culture. These peptides were derived from 1514 genes or 35% percent of proteins predicted to be encoded by the genome. A significant number of these proteins were detected within a single subcellular fraction and their localization was compared to in silico predictions. However, the majority of proteins were observed in multiple subcellular fractions, and the most likely subcellular localization for these proteins was investigated using a Z-score analysis of estimated protein abundance along with clustering techniques. Good (81%) agreement was observed between the experimental results and in silico predictions. The AMT tag approach provides localization evidence for those proteins that have no predicted localization information, those annotated as putative proteins, and/or for those proteins annotated as hypothetical and conserved hypothetical. PMID:16889416

  6. A counter-intuitive approach to calculating non-exchangeable 2H isotopic composition of hair: treating the molar exchange fraction fE as a process-related rather than compound-specific variable

    USGS Publications Warehouse

    Landwehr, J.M.; Meier-Augenstein, W.; Kemp, H.F.

    2011-01-01

    Hair is a keratinous tissue that incorporates hydrogen from material that an animal consumes but it is metabolically inert following synthesis. The stable hydrogen isotope composition of hair has been used in ecological studies to track migrations of mammals as well as for forensic and archaeological purposes to determine the provenance of human remains or the recent geographic life trajectory of living people. Measurement of the total hydrogen isotopic composition of a hair sample yields a composite value comprised of both metabolically informative, non-exchangeable hydrogen and exchangeable hydrogen, with the latter reflecting ambient or sample preparation conditions. Neither of these attributes is directly measurable, and the non-exchangeable hydrogen composition is obtained by estimation using a commonly applied mathematical expression incorporating sample measurements obtained from two distinct equilibration procedures. This commonly used approach treats the fraction of exchangeable hydrogen as a mixing ratio, with a minimal procedural fractionation factor assumed to be close or equal to 1. Instead, we propose to use full molar ratios to derive an expression for the non-exchangeable hydrogen composition explicitly as a function of both the procedural fractionation factor α and the molar hydrogen exchange fraction fE. We apply these derivations in a longitudinal study of a hair sample and demonstrate that the molar hydrogen exchange fraction fE should, like the procedural fractionation factor α, be treated as a process-dependent parameter, i.e. a reaction-specific constant. This is a counter-intuitive notion given that maximum theoretical values for the molar hydrogen exchange fraction fE can be calculated that are arguably protein-type specific and, as such, fE could be regarded as a compound-specific constant. We also make some additional suggestions for future approaches to determine the non-exchangeable hydrogen composition of hair and the use of

  7. An Industrial Ecology Approach to Municipal Solid Waste Management: II. Case Studies for Recovering Energy from the Organic Fraction of MSW

    EPA Science Inventory

    The organic fraction of municipal solid waste provides abundant opportunities for industrial ecology-based symbiotic use. Energy production, economics, and environmental aspects are analyzed for four alternatives based on different technologies: incineration with energy recovery...

  8. An Industrial Ecology Approach to Municipal Solid Waste Management: II. Case Studies for Recovering Energy from the Organic Fraction of MSW

    EPA Science Inventory

    The organic fraction of municipal solid waste provides abundant opportunities for industrial ecology-based symbiotic use. Energy production, economics, and environmental aspects are analyzed for four alternatives based on different technologies: incineration with energy recovery...

  9. [Salt intake in children].

    PubMed

    Girardet, J-P; Rieu, D; Bocquet, A; Bresson, J-L; Briend, A; Chouraqui, J-P; Darmaun, D; Dupont, C; Frelut, M-L; Hankard, R; Goulet, O; Simeoni, U; Turck, D; Vidailhet, M

    2014-05-01

    Very early in life, sodium intake correlates with blood pressure level. This warrants limiting the consumption of sodium by children. However, evidence regarding exact sodium requirements in that age range is lacking. This article focuses on the desirable sodium intake according to age as suggested by various groups of experts, on the levels of sodium intake recorded in consumption surveys, and on the public health strategies implemented to reduce salt consumption in the pediatric population. Practical recommendations are given by the Committee on nutrition of the French Society of Pediatrics in order to limit salt intake in children.

  10. A fractional Dirac equation and its solution

    NASA Astrophysics Data System (ADS)

    Muslih, Sami I.; Agrawal, Om P.; Baleanu, Dumitru

    2010-02-01

    This paper presents a fractional Dirac equation and its solution. The fractional Dirac equation may be obtained using a fractional variational principle and a fractional Klein-Gordon equation; both methods are considered here. We extend the variational formulations for fractional discrete systems to fractional field systems defined in terms of Caputo derivatives. By applying the variational principle to a fractional action S, we obtain the fractional Euler-Lagrange equations of motion. We present a Lagrangian and a Hamiltonian for the fractional Dirac equation of order α. We also use a fractional Klein-Gordon equation to obtain the fractional Dirac equation which is the same as that obtained using the fractional variational principle. Eigensolutions of this equation are presented which follow the same approach as that for the solution of the standard Dirac equation. We also provide expressions for the path integral quantization for the fractional Dirac field which, in the limit α → 1, approaches to the path integral for the regular Dirac field. It is hoped that the fractional Dirac equation and the path integral quantization of the fractional field will allow further development of fractional relativistic quantum mechanics.

  11. Application of an asymmetric flow field flow fractionation multi-detector approach for metallic engineered nanoparticle characterization--prospects and limitations demonstrated on Au nanoparticles.

    PubMed

    Hagendorfer, Harald; Kaegi, Ralf; Traber, Jacqueline; Mertens, Stijn F L; Scherrers, Roger; Ludwig, Christian; Ulrich, Andrea

    2011-11-14

    In this work we discuss about the method development, applicability and limitations of an asymmetric flow field flow fractionation (A4F) system in combination with a multi-detector setup consisting of UV/vis, light scattering, and inductively coupled plasma mass spectrometry (ICPMS). The overall aim was to obtain a size dependent-, element specific-, and quantitative method appropriate for the characterization of metallic engineered nanoparticle (ENP) dispersions. Thus, systematic investigations of crucial method parameters were performed by employing well characterized Au nanoparticles (Au-NPs) as a defined model system. For good separation performance, the A4F flow-, membrane-, and carrier conditions were optimized. To obtain reliable size information, the use of laser light scattering based detectors was evaluated, where an online dynamic light scattering (DLS) detector showed good results for the investigated Au-NP up to a size of 80 nm in hydrodynamic diameter. To adapt large sensitivity differences of the various detectors, as well as to guarantee long term stability and minimum contamination of the mass spectrometer a split-flow concept for coupling ICPMS was evaluated. To test for reliable quantification, the ICPMS signal response of ionic Au standards was compared to that of Au-NP. Using proper stabilization with surfactants, no difference for concentrations of 1-50 μg Au L(-1) in the size range from 5 to 80 nm for citrate stabilized dispersions was observed. However, studies using different A4F channel membranes showed unspecific particle-membrane interaction resulting in retention time shifts and unspecific loss of nanoparticles, depending on the Au-NP system as well as membrane batch and type. Thus, reliable quantification and discrimination of ionic and particular species was performed using ICPMS in combination with ultracentrifugation instead of direct quantification with the A4F multi-detector setup. Figures of merit were obtained, by comparing the

  12. Alternating layer addition approach to CdSe/CdS core/shell quantum dots with near-unity quantum yield and high on-time fractions

    PubMed Central

    Allen, Peter M.; Liu, Wenhao; Zhao, Jing; Young, Elizabeth R.; Popović, Zoran; Walker, Brian

    2014-01-01

    We report single-particle photoluminescence (PL) intermittency (blinking) with high on-time fractions in colloidal CdSe quantum dots (QD) with conformal CdS shells of 1.4 nm thickness, equivalent to approximately 4 CdS monolayers. All QDs observed displayed on-time fractions > 60% with the majority > 80%. The high-on-time-fraction blinking is accompanied by fluorescence quantum yields (QY) close to unity (up to 98% in an absolute QY measurement) when dispersed in organic solvents and a monoexponential ensemble photoluminescence (PL) decay lifetime. The CdS shell is formed in high synthetic yield using a modified selective ion layer adsorption and reaction (SILAR) technique that employs a silylated sulfur precursor. The CdS shell provides sufficient chemical and electronic passivation of the QD excited state to permit water solubilization with greater than 60% QY via ligand exchange with an imidazole-bearing hydrophilic polymer. PMID:24932403

  13. Low Incidence of Chest Wall Pain with a Risk-Adapted Lung Stereotactic Body Radiation Therapy Approach Using Three or Five Fractions Based on Chest Wall Dosimetry

    PubMed Central

    Lewis, John H.; Baldini, Elizabeth H.; Chen, Aileen B.; Colson, Yolonda L.; Hacker, Fred L.; Hermann, Gretchen; Kozono, David; Mannarino, Edward; Molodowitch, Christina; Wee, Jon O.; Sher, David J.; Killoran, Joseph H.

    2014-01-01

    Purpose To examine the frequency and potential of dose-volume predictors for chest wall (CW) toxicity (pain and/or rib fracture) for patients receiving lung stereotactic body radiotherapy (SBRT) using treatment planning methods to minimize CW dose and a risk-adapted fractionation scheme. Methods We reviewed data from 72 treatment plans, from 69 lung SBRT patients with at least one year of follow-up or CW toxicity, who were treated at our center between 2010 and 2013. Treatment plans were optimized to reduce CW dose and patients received a risk-adapted fractionation of 18 Gy×3 fractions (54 Gy total) if the CW V30 was less than 30 mL or 10–12 Gy×5 fractions (50–60 Gy total) otherwise. The association between CW toxicity and patient characteristics, treatment parameters and dose metrics, including biologically equivalent dose, were analyzed using logistic regression. Results With a median follow-up of 20 months, 6 (8.3%) patients developed CW pain including three (4.2%) grade 1, two (2.8%) grade 2 and one (1.4%) grade 3. Five (6.9%) patients developed rib fractures, one of which was symptomatic. No significant associations between CW toxicity and patient and dosimetric variables were identified on univariate nor multivariate analysis. Conclusions Optimization of treatment plans to reduce CW dose and a risk-adapted fractionation strategy of three or five fractions based on the CW V30 resulted in a low incidence of CW toxicity. Under these conditions, none of the patient characteristics or dose metrics we examined appeared to be predictive of CW pain. PMID:24728448

  14. Fruits and vegetables: measuring intake and encouraging increased consumption.

    PubMed

    Woodside, Jayne V; Young, Ian S; McKinley, Michelle C

    2013-05-01

    A high intake of fruit and vegetables (FV) is associated with reduced risk of chronic disease, although the evidence base is mostly observational. Blood biomarkers offer an objective indicator of FV intake, potentially improving estimates of intakes based on traditional methods. A valid biomarker of overall FV intake would be able to confirm population intakes, more precisely evaluate the association between intakes and health outcomes and confirm compliance in FV interventions. Several substances have been proposed as biomarkers of FV intake: vitamin C, the carotenoids and polyphenols. Certain biomarkers are strong predictors of single FV; however, the proposed single biomarkers of FV consumption are only modestly predictive of overall FV consumption. This is likely to be due to the complexity of the FV food group. While accurately measuring FV intake is important in nutrition research, another critical question is: how best can an increase in FV intake be achieved? Increased FV intake has been achieved in efficacy studies using intensive dietary advice. Alternative, less intensive methods for encouraging FV consumption need to be developed and tested for population level intervention. Systematic reviews suggest peer support to be an effective strategy to promote dietary change. This review will describe the evidence for a link between increased FV intake and good health, outline possible novel biomarkers of FV consumption, present the most recently available data on population intake of FV and examine the usefulness of different approaches to encourage increased consumption of FV.

  15. Numerical approximation of higher-order time-fractional telegraph equation by using a combination of a geometric approach and method of line

    NASA Astrophysics Data System (ADS)

    Hashemi, M. S.; Baleanu, D.

    2016-07-01

    We propose a simple and accurate numerical scheme for solving the time fractional telegraph (TFT) equation within Caputo type fractional derivative. A fictitious coordinate ϑ is imposed onto the problem in order to transform the dependent variable u (x , t) into a new variable with an extra dimension. In the new space with the added fictitious dimension, a combination of method of line and group preserving scheme (GPS) is proposed to find the approximate solutions. This method preserves the geometric structure of the problem. Power and accuracy of this method has been illustrated through some examples of TFT equation.

  16. Metal extractability patterns to evaluate (potentially) mobile fractions in periurban calcareous agricultural soils in the Mediterranean area-analytical and mineralogical approaches.

    PubMed

    de Santiago-Martín, Ana; Valverde-Asenjo, Inmaculada; Quintana, Jose R; Vázquez, Antonio; Lafuente, Antonio L; González-Huecas, Concepción

    2013-09-01

    A set of periurban calcareous agricultural Mediterranean soils was spiked with a mixture of Cd, Cu, Pb and Zn at two levels within the limit values proposed by current European legislation, incubated for up to 12 months, and subjected to various one-step extraction procedures to estimate mobile (neutral salts) and potentially mobile metal fractions (complexing and acidic extraction methods). The results obtained were used to study metal extractability patterns according to the soil characteristics. The analytical data were coupled with mineralogical investigations and speciation modelling using the Visual Minteq model. The formation of soluble metal-complexes in the complexing extracts (predicted by the Visual Minteq calculations) led to the highest extraction efficiency with complexing extractants. Metal extractability patterns were related to both content and composition of carbonate, organic matter, Fe oxide and clay fractions. Potentially mobile metal fractions were mainly affected by the finest soil fractions (recalcitrant organic matter, active lime and clay minerals). In the case of Pb, scarce correlations between extractable Pb and soil constituents were obtained which was attributed to high Pb retention due to the formation of 4PbCO3·3PbO (corroborated by X-ray diffraction). In summary, the high metal proportion extracted with complexing agents highlighted the high but finite capacity to store potentially mobilizable metals and the possible vulnerability of these soils against environmental impact from metal accumulation.

  17. Prevalence of pure versus mixed snow cover pixels across spatial resolutions in alpine environments: implications for binary and fractional remote sensing approaches

    USGS Publications Warehouse

    Selkowitz, David J.; Forster, Richard; Caldwell, Megan K.

    2014-01-01

    Remote sensing of snow-covered area (SCA) can be binary (indicating the presence/absence of snow cover at each pixel) or fractional (indicating the fraction of each pixel covered by snow). Fractional SCA mapping provides more information than binary SCA, but is more difficult to implement and may not be feasible with all types of remote sensing data. The utility of fractional SCA mapping relative to binary SCA mapping varies with the intended application as well as by spatial resolution, temporal resolution and period of interest, and climate. We quantified the frequency of occurrence of partially snow-covered (mixed) pixels at spatial resolutions between 1 m and 500 m over five dates at two study areas in the western U.S., using 0.5 m binary SCA maps derived from high spatial resolution imagery aggregated to fractional SCA at coarser spatial resolutions. In addition, we used in situ monitoring to estimate the frequency of partially snow-covered conditions for the period September 2013–August 2014 at 10 60-m grid cell footprints at two study areas with continental snow climates. Results from the image analysis indicate that at 40 m, slightly above the nominal spatial resolution of Landsat, mixed pixels accounted for 25%–93% of total pixels, while at 500 m, the nominal spatial resolution of MODIS bands used for snow cover mapping, mixed pixels accounted for 67%–100% of total pixels. Mixed pixels occurred more commonly at the continental snow climate site than at the maritime snow climate site. The in situ data indicate that some snow cover was present between 186 and 303 days, and partial snow cover conditions occurred on 10%–98% of days with snow cover. Four sites remained partially snow-free throughout most of the winter and spring, while six sites were entirely snow covered throughout most or all of the winter and spring. Within 60 m grid cells, the late spring/summer transition from snow-covered to snow-free conditions lasted 17–56 days and averaged 37

  18. Parent Diet Quality and Energy Intake Are Related to Child Diet Quality and Energy Intake.

    PubMed

    Robson, Shannon M; Couch, Sarah C; Peugh, James L; Glanz, Karen; Zhou, Chuan; Sallis, James F; Saelens, Brian E

    2016-06-01

    Parents' diets are believed to influence their children's diets. Previous studies have not adequately and simultaneously assessed the relationship between parent and child total diet quality and energy intakes. Our aim was to investigate whether parent and child diet quality and energy intakes are related. We conducted a cross-sectional analysis using baseline dietary intake data from the Neighborhood Impact on Kids study collected in 2007 to 2009. Participants were parents and 6- to 12-year-old children from households in King County (Seattle area), WA, and San Diego County, CA, targeted by Neighborhood Impact on Kids were recruited. Eligible parent-child dyads (n=698) with two or three 24-hour dietary recalls were included in this secondary analysis. Child diet quality (Healthy Eating Index-2010, Dietary Approaches to Stop Hypertension score, and energy density [for food only]) and energy intake were derived from the dietary recalls using Nutrition Data Systems for Research. Multiple linear regression models examined the relationship between parent diet quality and child diet quality, and the relationship between parent energy intake and child energy intake. In both analyses, we controlled for parent characteristics, child characteristics, household education, and neighborhood type. Parent diet quality measures were significantly related to corresponding child diet quality measures: Healthy Eating Index-2010 (standardized β=.39; P<0.001); Dietary Approaches to Stop Hypertension score (β=.33; P<0.001); and energy density (β=.32; P<0.001). Parent daily mean energy intake (1,763±524 kcal) was also significantly related (β=.30; P<0.001) to child daily mean energy intake (1,751±431 kcal). Parent and child intakes were closely related across various metrics of diet quality and for energy intake. Mechanisms of influence are likely to be shared food environments, shared meals, and parent modeling. Copyright © 2016 Academy of Nutrition and Dietetics. Published by

  19. Hydrothermal liquefaction of freshwater and marine algal biomass: A novel approach to produce distillate fuel fractions through blending and co-processing of biocrude with petrocrude.

    PubMed

    Lavanya, Melcureraj; Meenakshisundaram, Arunachalam; Renganathan, Sahadevan; Chinnasamy, Senthil; Lewis, David Milton; Nallasivam, Jaganathan; Bhaskar, Sailendra

    2016-03-01

    Biocrude was produced from Tetraselmis sp. - a marine alga and Arthrospira platensis - a fresh water alga using hydrothermal liquefaction (HTL) process. Considering the constraints in cultivating algae for replacing 100% petrocrude, this study evaluated the option of blending and co-processing algal biocrude with petrocrude. Biocrudes obtained from algal strains cultivated in fresh water and sea water were blended with petrocrude at 10% concentration and the characteristics were studied using FT-IR and CNS SIMDIST. True Boiling Point (TBP) distillation was carried out to assess yields and properties of distillates of blended biocrudes. Biocrudes obtained from both algae were light crudes and the blended crudes recorded distillate yields of 76-77 wt%. The yield of light naphtha fraction of biocrude blends was 29-30%; whereas the yield of diesel fraction was about 18%. This study proposes blending and co-processing of algal biocrude with petrocrude to produce drop-in biofuels.

  20. [Phosphorus intake and osteoporosis].

    PubMed

    Omi, N; Ezawa, I

    2001-10-01

    Phosphorus (P) is one of the most important nutrients for bone metabolism, such as calcium. In general, P intake is usually adequate in our daily diet, and there is a risk of over-consumption from processed food. On the other hand, Ca intake is not always adequate from the Japanese daily diet. When Ca/P is taken from the daily diet at a level of 0.5 - 2.0, the P intake level dose not affect intestinal Ca absorption. Therefore, it is important not only to pay attention to preventing the over-consumption of P, but also to obtain a sufficient intake of Ca. For the prevention of osteoporosis, it is important to consume sufficient Ca and to maintain and appropriate Ca/P balance from diet.

  1. Fine-grained clay fraction (,0.2 {mu}m): An interesting tool to approach the present thermal and permeability state in active geothermal systems

    SciTech Connect

    Patrier, P.; Papapanagiotou, P.; Beaufort, D.; Traineau, H.; Bril, H.

    1992-01-01

    We have investigated by X-ray diffraction the very fine grained secondary minerals (< 0.2 {micro}m) developed in geothermal systems, in relation with their present thermal and permeability state. Because the smallest particles are the most reactive part of a rock, they are the youngest mineral phases of the geothermal fields. This study has been performed on two active geothermal fields: Milos field, Greece (130 < T < 320 C) and Chipilapa field, Salvador (90 < T < 215 C). In the Milos field, the mineralogical composition of the < 0.2 {micro}m clay fraction observed in the reservoir strongly differs from the overlying altered metamorphic schists in the presence of abundant quantities of saponite and talc/saponite interstratified minerals at unusually high temperature. These phases are considered to be kinetically control-led ''metastable'' minerals which rapidly evolve towards actinolite and talc for present temperatures higher than 300 C. Their occurrence is a good indicator of discharge in highly permeable zones. In the geothermal field of Chipilapa, the mineralogical composition of the < 0.2 {micro}m clay fractions fairly agrees with the temperatures presently measured in the wells, whereas several discrepancies may be pointed out from the compositions of coarser clay fractions (< 5 {micro}m) which contain minerals inherited from higher temperature stages. Permeable zones may be evidenced from an increase of expandable components in the interstratified minerals and a decrease of the coherent domain of the unexpandable clay particles (chlorite).

  2. Turbulence control by intake

    NASA Astrophysics Data System (ADS)

    Pailhas, G.

    1991-01-01

    Results from the first part of an experimental study aimed at establishing the effects of a local intake by slots on a turbulent boundary layer are reported. Measurements were taken on the wall of a test vein of an Eiffel type wind tunnel. Results show that a local wall intake leads to a significant decrease of deflection type fluctuations of longitudinal velocity in the internal region of the boundary layer region where the turbulent production is maximum.

  3. Guidelines for predicting the dietary intake of pesticide residues*

    PubMed Central

    1988-01-01

    These guidelines have been developed to describe procedures for predicting the dietary intake of pesticide residues, and will assist national authorities in their considerations of the acceptability of the Codex maximum residue limits (MRLs). The relevant authorities are invited to consider the basic approaches described in these guidelines, which have been designed to provide reasonable assurance that such MRLs would not result in dietary intakes that exceed the acceptable daily intake (ADI) of a pesticide. PMID:3262445

  4. Central and peripheral control of food intake.

    PubMed

    Abdalla, M M I

    2017-01-01

    The maintenance of the body weight at a stable level is a major determinant in keeping the higher animals and mammals survive. Th e body weight depends on the balance between the energy intake and energy expenditure. Increased food intake over the energy expenditure of prolonged time period results in an obesity. Th e obesity has become an important worldwide health problem, even at low levels. The obesity has an evil effect on the health and is associated with a shorter life expectancy. A complex of central and peripheral physiological signals is involved in the control of the food intake. Centrally, the food intake is controlled by the hypothalamus, the brainstem, and endocannabinoids and peripherally by the satiety and adiposity signals. Comprehension of the signals that control food intake and energy balance may open a new therapeutic approaches directed against the obesity and its associated complications, as is the insulin resistance and others. In conclusion, the present review summarizes the current knowledge about the complex system of the peripheral and central regulatory mechanisms of food intake and their potential therapeutic implications in the treatment of obesity.

  5. Parent Diet Quality and Energy Intake Are Related to Child Diet Quality and Energy Intake

    PubMed Central

    Robson, Shannon M.; Couch, Sarah C.; Peugh, James L.; Glanz, Karen; Zhou, Chuan; Sallis, James F.; Saelens, Brian E.

    2016-01-01

    Background Parents' diets are believed to influence their children's diets. Previous studies have not adequately and simultaneously assessed the relation of parent and child total diet quality and energy intake. Objective To investigate if parent and child diet quality and energy intakes are related. Design A cross-sectional analysis using baseline dietary intake data from the Neighborhood Impact on Kids (NIK) study collected in 2007-2009. Participants/setting Parents and 6-12 year old children from households in King County (Seattle area), WA and San Diego County, CA, targeted by NIK were recruited. Eligible parent-child dyads (n=698) with two or three 24-hour dietary recalls were included in this secondary analysis. Main Outcome Measures Child diet quality (Healthy Eating Index-2010 [HEI-2010], Dietary Approaches to Stop Hypertension [DASH] score, and energy density (for food-only) and energy intake were derived from the dietary recalls using Nutrition Data Systems for Research. Statistical Analyses Performed Multiple linear regression models examined the relationship between parent diet quality and child diet quality, and the relationship between parent energy intake and child energy intake. In both analyses, we controlled for parent characteristics, child characteristics, household education and neighborhood type. Results Parent diet quality measures were significantly related to corresponding child diet quality measures: HEI-2010 (standardized beta [β] = 0.39, p<0.001); DASH score (β = 0.33, p<0.001); energy density (β = 0.32, p<0.001). Parent daily average energy intake (1763 ± 524 kilocalories) also was significantly related (β = 0.30, p<0.001) to child daily average energy intake (1751 ± 431 kilocalories). Conclusion Parent and child intakes were closely related across various metrics of diet quality and for energy intake. Mechanisms of influence are likely to be shared food environments, shared meals, and parent modeling. PMID:27050725

  6. Understanding Division of Fractions: An Alternative View

    ERIC Educational Resources Information Center

    Fredua-Kwarteng, E.; Ahia, Francis

    2006-01-01

    The purpose of this paper is to offer three alternatives to patterns or visualization used to justify division of fraction "algorithm" invert and multiply". The three main approaches are historical, similar denominators and algebraic, that teachers could use to justify the standard algorithm of division of fraction. The historical approach uses…

  7. Adaptive fractionation therapy: II. Biological effective dose.

    PubMed

    Chen, Mingli; Lu, Weiguo; Chen, Quan; Ruchala, Kenneth; Olivera, Gustavo

    2008-10-07

    Radiation therapy is fractionized to differentiate the cell killing between the tumor and organ at risk (OAR). Conventionally, fractionation is done by dividing the total dose into equal fraction sizes. However, as the relative positions (configurations) between OAR and the tumor vary from fractions to fractions, intuitively, we want to use a larger fraction size when OAR and the tumor are far apart and a smaller fraction size when OAR and the tumor are close to each other. Adaptive fractionation accounts for variations of configurations between OAR and the tumor. In part I of this series, the adaptation minimizes the OAR (physical) dose and maintains the total tumor (physical) dose. In this work, instead, the adaptation is based on the biological effective dose (BED). Unlike the linear programming approach in part I, we build a fraction size lookup table using mathematical induction. The lookup table essentially describes the fraction size as a function of the remaining tumor BED, the OAR/tumor dose ratio and the remaining number of fractions. The lookup table is calculated by maximizing the expected survival of OAR and preserving the tumor cell kill. Immediately before the treatment of each fraction, the OAR-tumor configuration and thus the dose ratio can be obtained from the daily setup image, and then the fraction size can be determined by the lookup table. Extensive simulations demonstrate the effectiveness of our method compared with the conventional fractionation method.

  8. Persistence of low levels of plasma viremia and of the latent reservoir in patients under ART: A fractional-order approach

    NASA Astrophysics Data System (ADS)

    Pinto, Carla M. A.

    2017-02-01

    Low levels of viral load are found in HIV-infected patients, after many years under successful suppressive anti-retroviral therapy (ART). The factors leading to this persistence are still under debate, but it is now more or less accepted that the latent reservoir may be crucial to the maintenance of this residual viremia. In this paper, we study the role of the latent reservoir in the persistence of the latent reservoir and of the plasma viremia in a fractional-order (FO) model for HIV infection. Our model assumes that (i) the latently infected cells may undergo bystander proliferation, without active viral production, (ii) the latent cell activation rate decreases with time on ART, (iii) the productively infected cells' death rate is a function of the infected cell density. The proposed model provides new insights on the role of the latent reservoir in the persistence of the latent reservoir and of the plasma virus. Moreover, the fractional-order derivative distinguishes distinct velocities in the dynamics of the latent reservoir and of plasma virus. The later may be used to better approximations of HIV-infected patients data. To our best knowledge, this is the first FO model that deals with the role of the latent reservoir in the persistence of low levels of viremia and of the latent reservoir.

  9. Fractional order PID control design for semi-active control of smart base-isolated structures: A multi-objective cuckoo search approach.

    PubMed

    Zamani, Abbas-Ali; Tavakoli, Saeed; Etedali, Sadegh

    2017-03-01

    Fractional order PID (FOPID) controllers are introduced as a general form of classical PID controllers using fractional calculus. As this controller provides good disturbance rejection and is robust against plant uncertainties it is appropriate for the vibration mitigation in structures. In this paper, an FOPID controller is designed to adjust the contact force of piezoelectric friction dampers for semi-active control of base-isolated structures during far-field and near-field earthquake excitations. A multi-objective cuckoo search algorithm is employed to tune the controller parameters. Considering the resulting Pareto optimal front, the best input for the FOPID controller is selected. For seven pairs of earthquakes and nine performance indices, the performance of the proposed controller is compared with those provided by several well-known control techniques. According to the simulation results, the proposed controller performs better than other controllers in terms of simultaneous reduction of the maximum base displacement and story acceleration for various types of earthquakes. Also, it provides acceptable responses in terms of inter-story drifts, root mean square of base displacements and floor acceleration. In addition, the evaluation of robustness for a stiffness uncertainty of ±10% indicates that the proposed controller gives a robust performance against such modeling errors.

  10. Exploratory characterization of the unsaponifiable fraction of tunisian virgin olive oils by a global approach with HPLC-APCI-IT MS/MS analysis.

    PubMed

    Zarrouk, Wissem; Carrasco-Pancorbo, Alegría; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto; Zarrouk, Mokhtar

    2010-05-26

    The unsaponifiable fraction of six Tunisian monovarietal virgin olive oils from the region of Medenine was evaluated within a single chromatographic run by using HPLC-APCI-tandem MS. Separation of the compounds under study was achieved by the RP-LC method, giving a reasonable analysis time and good resolution. Detection was done by an ion trap (working alternatively in MS and MS/MS modes), the fact which made our method suitable to unequivocally identify a high number of compounds belonging to different families of the unsaponifiable fraction of oil and to carry out their reliable and sensitive quantification. A great amount of qualitative information was generated in every analysis, although we focused on the quantification of sterols, tocopherols, and triterpenic dialcohols since their standards were commercially available. The limits of detections achieved were within the range of 1.21 and 10.31 microg/kg for sitostanol and beta-sitosterol, respectively. Significant differences were observed in the composition of the studied olive cultivars. Jemri Ben Guerdane oil was the richest one in terms of all of the sterols under study. alpha-Tocopherol was the main vitamin E isomer in all samples, ranging from 70.14 to 130.72 mg/kg. Principal component analysis (PCA) and cluster analysis were applied to the whole data set in order to explore the distribution of the olive cultivars according to their oil composition.

  11. Fractional factorial approach combining 4 Escherichia coli strains, 3 culture media, 3 expression temperatures and 5 N-terminal fusion tags for screening the soluble expression of recombinant proteins.

    PubMed

    Noguère, Christophe; Larsson, Anna M; Guyot, Jean-Christophe; Bignon, Christophe

    2012-08-01

    Producing recombinant proteins in Escherichia coli (E. coli) is generally performed using a trial and error approach with the different expression variables being tested independently from each other. As a consequence, variable interactions are lost which makes the trial and error approach quite time-consuming. In this paper, we report how switching from a trial and error to a fractional factorial approach allows testing in less than 2 weeks four expression variables (E. coli strains, culture media, expression temperatures and N-terminal fusion tags) in a single experiment. The method, called "Fusion-InFFact", was validated using four test proteins. In all cases, Fusion-InFFact allowed finding conditions for expressing high yields of soluble proteins. The method was originally set-up for high throughput structural genomics programs, but can be used in any recombinant protein expression project.

  12. Protein intakes in India.

    PubMed

    Swaminathan, Sumathi; Vaz, Mario; Kurpad, Anura V

    2012-08-01

    Indian diets derive almost 60 % of their protein from cereals with relatively low digestibility and quality. There have been several surveys of diets and protein intakes in India by the National Nutrition Monitoring Board (NNMB) over the last 25 years, in urban and rural, as well as in slum dwellers and tribal populations. Data of disadvantaged populations from slums, tribals and sedentary rural Indian populations show that the protein intake (mainly from cereals) is about 1 gm/kg/day. However, the protein intake looks less promising in terms of the protein digestibility corrected amino acid score (PDCAAS), using lysine as the first limiting amino acid, where all populations, particularly rural and tribal, appear to have an inadequate quality to their protein intake. The protein: energy (PE) ratio is a measure of dietary quality, and has been used in the 2007 WHO/FAO/UNU report to define reference requirement values with which the adequacy of diets can be evaluated in terms of a protein quality corrected PE ratio. It is likely that about one third of this sedentary rural population is at risk of not meeting their requirements. These levels of risk of deficiency are in a population with relatively low BMI populations, whose diets are also inadequate in fruits and vegetables. Therefore, while the burden of enhancing the quality of protein intake in rural India exists, the quality of the diet, in general, represents a challenge that must be met.

  13. Sodium intake and hypertension.

    PubMed

    Karppanen, Heikki; Mervaala, Eero

    2006-01-01

    In current diets, the level of sodium is very high, whereas that of potassium, calcium, and magnesium is low compared with the level in diets composed of unprocessed, natural foods. We present the biologic rationale and scientific evidence that show that the current salt intake levels largely explain the high prevalence of hypertension. Comprehensive reduction of salt intake, both alone and particularly in combination with increases in intakes of potassium, calcium, and magnesium, is able to lower average blood pressure levels substantially. During the past 30 years, the one-third decrease in the average salt intake has been accompanied by a more than 10-mm Hg fall in the population average of both systolic and diastolic blood pressure, and a 75% to 80% decrease in both stroke and coronary heart disease mortality in Finland. There is no evidence of any harmful effects of salt reduction. Salt-reduction recommendations alone have a very small, if any, population impact. In the United States, for example, the per capita use of salt increased by approximately 55% from the mid-1980s to the late 1990s. We deal with factors that contribute toward increasing salt intakes and present examples of the methods that have contributed to the successful salt reduction in Finland.

  14. An Analytical Pipeline for Quantitative Characterization of Dietary Intake: Application To Assess Grape Intake.

    PubMed

    Garcia-Perez, Isabel; Posma, Joram M; Chambers, Edward S; Nicholson, Jeremy K; C Mathers, John; Beckmann, Manfred; Draper, John; Holmes, Elaine; Frost, Gary

    2016-03-23

    Lack of accurate dietary assessment in free-living populations requires discovery of new biomarkers reflecting food intake qualitatively and quantitatively to objectively evaluate effects of diet on health. We provide a proof-of-principle for an analytical pipeline to identify quantitative dietary biomarkers. Tartaric acid was identified by nuclear magnetic resonance spectroscopy as a dose-responsive urinary biomarker of grape intake and subsequently quantified in volunteers following a series of 4-day dietary interventions incorporating 0 g/day, 50 g/day, 100 g/day, and 150 g/day of grapes in standardized diets from a randomized controlled clinical trial. Most accurate quantitative predictions of grape intake were obtained in 24 h urine samples which have the strongest linear relationship between grape intake and tartaric acid excretion (r(2) = 0.90). This new methodological pipeline for estimating nutritional intake based on coupling dietary intake information and quantified nutritional biomarkers was developed and validated in a controlled dietary intervention study, showing that this approach can improve the accuracy of estimating nutritional intakes.

  15. Experimental study on the gas exchange process of different intake valve closing in a 4-stroke diesel engine

    NASA Astrophysics Data System (ADS)

    Wang, Ziyu; Wu, Peishan; Li, Yaozong; Cai, Zhongzhou; Liu, Jinlong

    2017-05-01

    A single cylinder diesel engine was modified to operate at different late intake valve closing timings (LIVC), the gas exchange process is studied by experiment. The results shows that with the retard of intake valve closing times (IVC), the losses of gas exchange work are decreased at the same intake air flow conditions, and the pressure drops of intake process are increased, the scavenging processes strengthen, and the residual gas fractions in cylinder are obviously decreased.

  16. Ca isotope fractionation and Sr/Ca partitioning associated with anhydrite formation at mid-ocean ridge hydrothermal systems: An experimental approach

    NASA Astrophysics Data System (ADS)

    Syverson, D. D.; Scheuermann, P.; Pester, N. J.; Higgins, J. A.; Seyfried, W. E., Jr.

    2016-12-01

    The elemental and isotopic mass balance of Ca and Sr between seawater and basalt at mid-ocean ridge (MOR) hydrothermal systems is an integrated reflection of the various physiochemical processes, which induce chemical exchange, in the subseafloor. Specifically, the processes of anhydrite precipitation and recrystallization are recognized to be important controls on governing the Ca and Sr elemental and isotope compositions of high temperature vent fluids, however, few experimental data exist to constrain these geochemical effects. Thus, to better understand the associated Sr/Ca partitioning and Ca isotope fractionation and rate of exchange between anhydrite and dissolved constituents, anhydrite precipitation and recrystallization experiments were performed at 175, 250, and 350°C and 500 bar at chemical conditions indicative of active MOR hydrothermal systems. The experimental data suggest that upon entrainment of seawater into MOR hydrothermal systems, anhydrite will precipitate rapidly and discriminate against the heavy isotopes of Ca (Δ44/40Ca(Anh-Fluid) = -0.68 - -0.25 ‰), whereas Sr/Ca partitioning depends on the saturation state of the evolving hydrothermal fluid with respect to anhydrite at each PTX (KD(Anh-Fluid) = 1.24 - 0.55). Coupling experimental constraints with the temperature gradient inferred for high temperature MOR hydrothermal systems in the oceanic crust, data suggest that the Ca isotope and Sr elemental composition of anhydrite formed near the seafloor will be influenced by disequilibrium effects, while, at higher temperatures further into the oceanic crust, anhydrite will be representative of equilibrium Sr/Ca partitioning and Ca isotope fractionation conditions. These experimental observations are consistent with analyzed Sr/Ca and Ca isotope compositions of anhydrites and vent fluids sampled from modern MOR hydrothermal systems1,2 and can be used to further constrain the geochemical effects of hydrothermal circulation in the oceanic crust

  17. Fiducial-free CyberKnife stereotactic body radiation therapy (SBRT) for single vertebral body metastases: acceptable local control and normal tissue tolerance with 5 fraction approach.

    PubMed

    Gill, Beant; Oermann, Eric; Ju, Andrew; Suy, Simeng; Yu, Xia; Rabin, Jennifer; Kalhorn, Christopher; Nair, Mani N; Voyadzis, Jean-Marc; Unger, Keith; Collins, Sean P; Harter, K W; Collins, Brian T

    2012-01-01

    This retrospective analysis examines the local control and toxicity of five-fraction fiducial-free CyberKnife stereotactic body radiation therapy (SBRT) for single vertebral body (VB) metastases. All patients had favorable performance status (ECOG 0-1), oligometastatic disease, and no prior spine irradiation. A prescribed dose of 30-35 Gy was delivered in five fractions to the planning target volume (PTV) using the CyberKnife with X-sight spine tracking. Suggested maximum spinal cord and esophagus point doses were 30 and 40 Gy, respectively. A median 30 Gy (IQR, 30-35 Gy) dose was delivered to a median prescription isodose line of 70% (IQR, 65-77%) to 20 patients. At 34 months median follow-up (IQR, 25-40 months) for surviving patients, the 1- and 2-year Kaplan-Meier local control estimates were 80 and 73%, respectively. Two of the five local failures were infield in patients who had received irradiation to the gross tumor volume and three were paravertebral failures just outside the PTV in patients with prior corpectomy. No local failures occurred in patients who completed VB radiation alone. The 1- and 2-year Kaplan-Meier overall survival estimates were 80 and 57%, respectively. Most deaths were attributed to metastatic disease; one death was attributed to local recurrence. The mean maximum point doses were 26.4 Gy (SD, 5.1 Gy) to the spinal cord and 29.1 Gy (SD, 8.9 Gy) to the esophagus. Patients receiving maximum esophagus point doses greater than 35 Gy experienced acute dysphagia (Grade I/II). No spinal cord toxicity was documented. Five-fraction fiducial-free CyberKnife SBRT is an acceptable treatment option for newly diagnosed VB metastases with promising local control rates and minimal toxicity despite the close proximity of such tumors to the spinal cord and esophagus. A prospective study aimed at further enhancing local control by targeting the intact VB and escalating the total dose is planned.

  18. Stroop interference and food intake.

    PubMed

    Overduin, J; Jansen, A; Louwerse, E

    1995-11-01

    The Stroop task is aimed at assessing attentional bias. Words are displayed one by one on a computer screen and subjects are instructed to name the color in which every word is printed. The attentional bias is supposed to be reflected in the extent to which the word meanings interfere with the speed of color naming: The longer the color naming latency, the larger the attentional bias. Experiments using this task have demonstrated attentional bias for eating and body shape-related words in bulimic, anorexic, and restrained subjects. Explanations of these results have generally been formulated in terms of restricted food intake or emotional concerns about food and body shape-related themes. In contrast, in the present article it was proposed that Stroop interference might reflect a tendency either to withdraw or approach food or body shape-related stimuli. Fifty-one subjects (25 unrestrained, 26 restrained) were administered a Stroop task containing neutral, food, and body shape-related words. There were two conditions to which subjects were randomly allocated: the "appetizer" and "no-appetizer" condition. The appetizer was a bit of pudding to be ingested by the subject just before the Stroop task. Following the Stroop task an ice cream taste test was presented in which the subjects were allowed to eat as much as they liked. The amount of ice cream eaten was registered secretly. The results show that in unrestrained subjects Stroop interference for food words was found only in the appetizer condition. Restrained subjects, however, showed a permanent interference for food words. A significant correlation of .58 between Stroop food-word interference and ice cream intake was found only in unrestrained subjects. In restrained eaters the correlation was near 0. No effect of condition or restraint was found on Stroop body shape-word interference. The findings indicate that (1) ingestion of an appetizer seems to have evoked an attentional bias for food words in

  19. A new analytical approach based on asymmetrical flow field-flow fractionation coupled to ultraviolet spectrometry and light scattering detection for SWCNT aqueous dispersion studies.

    PubMed

    Gigault, Julien; Grassl, Bruno; Lespes, Gaëtane

    2012-02-21

    This work demonstrates the potential of asymmetrical flow field-flow fractionation (A4F) coupled to Ultraviolet spectrometry (UV) and multi-angle light scattering (MALS) for the study of single-walled carbon nanotube (SWCNT) dispersion in aqueous solutions containing a surfactant. The results indicate that this technique is a powerful analytical tool that is able to evaluate SWCNT dispersion states in aqueous media and, more importantly, determine the presence or absence of aggregates, the numbers and sizes of different SWCNT populations and the SWCNT size distribution. Dynamic light scattering was employed to complete and demonstrate the relevance of the data that were obtained via A4F-UV-MALS. Two different anionic surfactants that are used to disperse SWCNTs were then studied. The dispersing powers of the surfactants were experimentally evaluated based on their structural organizations. This study demonstrates that surfactant concentration and sonication energy are key parameters that control the SWCNT dispersion state and SWCNT structural integrity therein.

  20. Energy Intake from Restaurants

    PubMed Central

    Powell, Lisa M.; Nguyen, Binh T.; Han, Euna

    2012-01-01

    Background Eating food away from home and restaurant consumption have increased over the past few decades. Purpose To examine recent changes in calories from fast-food and full-service restaurant consumption and to assess characteristics associated with consumption. Methods Analyses of 24-hour dietary recalls from children, adolescents, and adults using nationally representative data from the 2003–2004 through 2007–2008 National Health and Nutrition Examination Surveys, including analysis by gender, ethnicity, income and location of consumption. Multivariate regression analyses of associations between demographic and socioeconomic characteristics and consumption prevalence and average daily caloric intake from fast-food and full-service restaurants. Results In 2007–2008, 33%, 41% and 36% of children, adolescents and adults, respectively, consumed foods and/or beverages from fast-food restaurant sources and 12%, 18% and 27% consumed from full-service restaurants. Their respective mean caloric intake from fast food was 191 kcal, 404 kcal, and 315 kcal, down by 25% (p≤0.05), 3% and 9% from 2003–2004; and among consumers, intake was 576 kcal, 988 kcal, and 877 kcal, respectively, down by 12% (p≤0.05), 2% and 7%. There were no changes in daily calories consumed from full-service restaurants. Consumption prevalence and average daily caloric intake from fast-food (adults only) and full-service restaurants (all age groups) were higher when consumed away from home versus at home. There were some demographic and socioeconomic associations with the likelihood of fast-food consumption, but characteristics were generally not associated with the extent of caloric intake among those who consumed from fast-food or from full-service restaurants. Conclusions In 2007–2008, fast-food and full-service restaurant consumption remained prevalent and a source of substantial energy intake. PMID:23079172

  1. Fate of metals in coastal sediments of a Mediterranean flood-dominated system: An approach based on total and labile fractions

    NASA Astrophysics Data System (ADS)

    Roussiez, Vincent; Ludwig, Wolfgang; Radakovitch, Olivier; Probst, Jean-Luc; Monaco, André; Charrière, Bruno; Buscail, Roselyne

    2011-05-01

    The dynamics of sediment-bound metals (Cs, Cu, Ni, Pb, Ti and Zn) were studied off the Têt River (western Gulf of Lion), a typical Mediterranean coastal river punctuated by short and violent flash-floods. Spatial and temporal sampling strategies were combined to elucidate the fate of these elements in response to both the riverine sediment input and the offshore transport of these sediments through hydrodynamics. Our results show the temporal entrapment of riverborne particles and associated metals, consecutively to a major flood event, in the nearshore sedimentary unit called prodelta. Here, deposition and resuspension mechanisms define a sedimentological cycle that could be followed completely in this study. In terms of speciation between reactive (labile) and residual fractions along the fluvio-deltaic continuum, our results show that Cu, Pb and Zn are the most labile (potentially mobile) metals in the river, in accordance with their contributions from anthropogenic sources. But in the marine surficial sediments, two main behaviours can be discriminated when compared to the riverine suspended particulate matter. While Pb and Zn depict rather a constant labile fraction, Cu is characterized by decreasing levels (up to 50% difference). In terms of environmental impact, these contrasting trends have direct repercussions for the contaminant dispersal in the coastal area. Whereas Pb and Zn conserve their enhanced levels because of their stronger affinity with fine sediments, Cu is marked by the entire loss of its anthropogenic component that is progressively transferred to the dissolved phase, likely mediated by organic ligands. We ascribe these behaviours to different post-depositional partition mechanisms with respect to oxidation of the particulate organic phase at the bottom sediment/water interface. Also, analysis of one sediment core from the prodelta indicates that these early diagenetic processes govern the chemical forms of land-derived contaminants

  2. Initialized Fractional Calculus

    NASA Technical Reports Server (NTRS)

    Lorenzo, Carl F.; Hartley, Tom T.

    2000-01-01

    This paper demonstrates the need for a nonconstant initialization for the fractional calculus and establishes a basic definition set for the initialized fractional differintegral. This definition set allows the formalization of an initialized fractional calculus. Two basis calculi are considered; the Riemann-Liouville and the Grunwald fractional calculi. Two forms of initialization, terminal and side are developed.

  3. Fractional Action Cosmology with Variable Order Parameter

    NASA Astrophysics Data System (ADS)

    El-Nabulsi, Rami Ahmad

    2017-01-01

    Fractional action cosmology with variable order parameter was constructed in this paper. Starting from a fractional weighted action which generalizes the fractional actionlike variational approach, a large number of cosmological dynamical equations are obtained depending on the mathematical type of the fractional order parameter. Through this paper, we selected two independent types which result on a number of cosmological scenarios and we discussed their dynamical consequences. It was observed that the present fractional cosmological formalism holds a large family of solutions and offers new features not found in the standard formalism and in many fundamental research papers.

  4. Fractional Action Cosmology with Variable Order Parameter

    NASA Astrophysics Data System (ADS)

    El-Nabulsi, Rami Ahmad

    2017-04-01

    Fractional action cosmology with variable order parameter was constructed in this paper. Starting from a fractional weighted action which generalizes the fractional actionlike variational approach, a large number of cosmological dynamical equations are obtained depending on the mathematical type of the fractional order parameter. Through this paper, we selected two independent types which result on a number of cosmological scenarios and we discussed their dynamical consequences. It was observed that the present fractional cosmological formalism holds a large family of solutions and offers new features not found in the standard formalism and in many fundamental research papers.

  5. Tempered fractional calculus

    SciTech Connect

    Sabzikar, Farzad; Meerschaert, Mark M.; Chen, Jinghua

    2015-07-15

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  6. Biomarker of whole grain wheat intake associated lower BMI in older adults

    USDA-ARS?s Scientific Manuscript database

    Alkylresorcinols (AR) are phenolic lipids in the bran fraction of some whole grains (wheat, rye and barley). Plasma AR reflect recent intake of these whole grains. We examined the cross-sectional associations between plasma AR (measured by LCMS/ MS), whole wheat intake, and body mass index (BMI) in ...

  7. Peptides and food intake.

    PubMed

    Sobrino Crespo, Carmen; Perianes Cachero, Aránzazu; Puebla Jiménez, Lilian; Barrios, Vicente; Arilla Ferreiro, Eduardo

    2014-01-01

    The mechanisms for controlling food intake involve mainly an interplay between gut, brain, and adipose tissue (AT), among the major organs. Parasympathetic, sympathetic, and other systems are required for communication between the brain satiety center, gut, and AT. These neuronal circuits include a variety of peptides and hormones, being ghrelin the only orexigenic molecule known, whereas the plethora of other factors are inhibitors of appetite, suggesting its physiological relevance in the regulation of food intake and energy homeostasis. Nutrients generated by food digestion have been proposed to activate G-protein-coupled receptors on the luminal side of enteroendocrine cells, e.g., the L-cells. This stimulates the release of gut hormones into the circulation such as glucagon-like peptide-1 (GLP-1), oxyntomodulin, pancreatic polypeptides, peptide tyrosine tyrosine, and cholecystokinin, which inhibit appetite. Ghrelin is a peptide secreted from the stomach and, in contrast to other gut hormones, plasma levels decrease after a meal and potently stimulate food intake. Other circulating factors such as insulin and leptin relay information regarding long-term energy stores. Both hormones circulate at proportional levels to body fat content, enter the CNS proportionally to their plasma levels, and reduce food intake. Circulating hormones can influence the activity of the arcuate nucleus (ARC) neurons of the hypothalamus, after passing across the median eminence. Circulating factors such as gut hormones may also influence the nucleus of the tractus solitarius (NTS) through the adjacent circumventricular organ. On the other hand, gastrointestinal vagal afferents converge in the NTS of the brainstem. Neural projections from the NTS, in turn, carry signals to the hypothalamus. The ARC acts as an integrative center, with two major subpopulations of neurons influencing appetite, one of them coexpressing neuropeptide Y and agouti-related protein (AgRP) that increases food

  8. Peptides and Food Intake

    PubMed Central

    Sobrino Crespo, Carmen; Perianes Cachero, Aránzazu; Puebla Jiménez, Lilian; Barrios, Vicente; Arilla Ferreiro, Eduardo

    2014-01-01

    The mechanisms for controlling food intake involve mainly an interplay between gut, brain, and adipose tissue (AT), among the major organs. Parasympathetic, sympathetic, and other systems are required for communication between the brain satiety center, gut, and AT. These neuronal circuits include a variety of peptides and hormones, being ghrelin the only orexigenic molecule known, whereas the plethora of other factors are inhibitors of appetite, suggesting its physiological relevance in the regulation of food intake and energy homeostasis. Nutrients generated by food digestion have been proposed to activate G-protein-coupled receptors on the luminal side of enteroendocrine cells, e.g., the L-cells. This stimulates the release of gut hormones into the circulation such as glucagon-like peptide-1 (GLP-1), oxyntomodulin, pancreatic polypeptides, peptide tyrosine tyrosine, and cholecystokinin, which inhibit appetite. Ghrelin is a peptide secreted from the stomach and, in contrast to other gut hormones, plasma levels decrease after a meal and potently stimulate food intake. Other circulating factors such as insulin and leptin relay information regarding long-term energy stores. Both hormones circulate at proportional levels to body fat content, enter the CNS proportionally to their plasma levels, and reduce food intake. Circulating hormones can influence the activity of the arcuate nucleus (ARC) neurons of the hypothalamus, after passing across the median eminence. Circulating factors such as gut hormones may also influence the nucleus of the tractus solitarius (NTS) through the adjacent circumventricular organ. On the other hand, gastrointestinal vagal afferents converge in the NTS of the brainstem. Neural projections from the NTS, in turn, carry signals to the hypothalamus. The ARC acts as an integrative center, with two major subpopulations of neurons influencing appetite, one of them coexpressing neuropeptide Y and agouti-related protein (AgRP) that increases food

  9. A novel approach of anaerobic co-digestion between organic fraction of food waste and waste sludge from municipal wastewater treatment plant: Effect of mixing ratio

    NASA Astrophysics Data System (ADS)

    Nga, Dinh Thi; Ngoc, Tran Thi Minh; Van Ty, Nguyen; Thuan, Van Tan

    2017-09-01

    The aim of this study was to investigate the effect of mixing ratio of co-anaerobic digestion between dewatered waste sludge from municipal wastewater treatment plant (DS) and organic fraction of food waste (FW). The experiment was carried out in 3L reactors for 16 days at ambient temperature. Four mixing ratios of DW and FW was investigated including 100 % DS : 0 % FW (Run S100); 75% DS : 25 % FW (Run S75); 50% DS : 50% FW (Run S50); and 25% DS : 75% FW (Run S25) in term of VS concentration. As a result, the Run S50 achieved best performance among the four funs indicated in biogas accumulation of 32.48 L biogas and methane yield of 358.9 400ml CH4/g VS removal after 16 days operation at ambient temperature. Biogas accumulation of Run S25 was higher than that of Run S75. Run S100 produced the lowest of biogas of all runs. It is concluded that co-anaerobic digestion of different organic sources could enhance the performance of methane fermentation.

  10. Combining gas-phase electrophoretic mobility molecular analysis (GEMMA), light scattering, field flow fractionation and cryo electron microscopy in a multidimensional approach to characterize liposomal carrier vesicles.

    PubMed

    Urey, Carlos; Weiss, Victor U; Gondikas, Andreas; von der Kammer, Frank; Hofmann, Thilo; Marchetti-Deschmann, Martina; Allmaier, Günter; Marko-Varga, György; Andersson, Roland

    2016-11-20

    For drug delivery, characterization of liposomes regarding size, particle number concentrations, occurrence of low-sized liposome artefacts and drug encapsulation are of importance to understand their pharmacodynamic properties. In our study, we aimed to demonstrate the applicability of nano Electrospray Gas-Phase Electrophoretic Mobility Molecular Analyser (nES GEMMA) as a suitable technique for analyzing these parameters. We measured number-based particle concentrations, identified differences in size between nominally identical liposomal samples, and detected the presence of low-diameter material which yielded bimodal particle size distributions. Subsequently, we compared these findings to dynamic light scattering (DLS) data and results from light scattering experiments coupled to Asymmetric Flow-Field Flow Fractionation (AF4), the latter improving the detectability of smaller particles in polydisperse samples due to a size separation step prior detection. However, the bimodal size distribution could not be detected due to method inherent limitations. In contrast, cryo transmission electron microscopy corroborated nES GEMMA results. Hence, gas-phase electrophoresis proved to be a versatile tool for liposome characterization as it could analyze both vesicle size and size distribution. Finally, a correlation of nES GEMMA results with cell viability experiments was carried out to demonstrate the importance of liposome batch-to-batch control as low-sized sample components possibly impact cell viability. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Combining gas-phase electrophoretic mobility molecular analysis (GEMMA), light scattering, field flow fractionation and cryo electron microscopy in a multidimensional approach to characterize liposomal carrier vesicles

    PubMed Central

    Gondikas, Andreas; von der Kammer, Frank; Hofmann, Thilo; Marchetti-Deschmann, Martina; Allmaier, Günter; Marko-Varga, György; Andersson, Roland

    2017-01-01

    For drug delivery, characterization of liposomes regarding size, particle number concentrations, occurrence of low-sized liposome artefacts and drug encapsulation are of importance to understand their pharmacodynamic properties. In our study, we aimed to demonstrate the applicability of nano Electrospray Gas-Phase Electrophoretic Mobility Molecular Analyser (nES GEMMA) as a suitable technique for analyzing these parameters. We measured number-based particle concentrations, identified differences in size between nominally identical liposomal samples, and detected the presence of low-diameter material which yielded bimodal particle size distributions. Subsequently, we compared these findings to dynamic light scattering (DLS) data and results from light scattering experiments coupled to Asymmetric Flow-Field Flow Fractionation (AF4), the latter improving the detectability of smaller particles in polydisperse samples due to a size separation step prior detection. However, the bimodal size distribution could not be detected due to method inherent limitations. In contrast, cryo transmission electron microscopy corroborated nES GEMMA results. Hence, gas-phase electrophoresis proved to be a versatile tool for liposome characterization as it could analyze both vesicle size and size distribution. Finally, a correlation of nES GEMMA results with cell viability experiments was carried out to demonstrate the importance of liposome batch-to-batch control as low-sized sample components possibly impact cell viability. PMID:27639623

  12. Dietary intakes of pesticides based on community duplicate diet samples

    EPA Science Inventory

    The calculation of dietary intake of selected pesticides was accomplished using food samples collected from individual representatives of a defined demographic community using a community duplicate diet approach. A community of nine participants was identified in Apopka, FL from...

  13. Dietary intakes of pesticides based on community duplicate diet samples

    EPA Science Inventory

    The calculation of dietary intake of selected pesticides was accomplished using food samples collected from individual representatives of a defined demographic community using a community duplicate diet approach. A community of nine participants was identified in Apopka, FL from...

  14. TEMPERED FRACTIONAL CALCULUS

    PubMed Central

    MEERSCHAERT, MARK M.; SABZIKAR, FARZAD; CHEN, JINGHUA

    2014-01-01

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series. PMID:26085690

  15. Fraction Sense: Foundational Understandings.

    PubMed

    Fennell, Francis Skip; Karp, Karen

    2016-08-09

    The intent of this commentary is to identify elements of fraction sense and note how the research studies provided in this special issue, in related but somewhat different ways, validate the importance of such understandings. Proficiency with fractions serves as a prerequisite for student success in higher level mathematics, as well as serving as a gateway to many occupations and varied contexts beyond the mathematics classroom. Fraction sense is developed through instructional opportunities involving fraction equivalence and magnitude, comparing and ordering fractions, using fraction benchmarks, and computational estimation. Such foundations are then extended to operations involving fractions and decimals and applications involving proportional reasoning. These components of fraction sense are all addressed in the studies provided in this issue, with particular consideration devoted to the significant importance of the use of the number line as a central representational tool for conceptually understanding fraction magnitude. © Hammill Institute on Disabilities 2016.

  16. The Use of Total Human Bone Marrow Fraction in a Direct Three-Dimensional Expansion Approach for Bone Tissue Engineering Applications: Focus on Angiogenesis and Osteogenesis

    PubMed Central

    Oliveira, Hugo; Catros, Sylvain; Siadous, Robin; Derkaoui, Sidi-Mohammed; Bareille, Reine; Letourneur, Didier; Amédée, Joëlle

    2015-01-01

    Current approaches in bone tissue engineering have shown limited success, mostly owing to insufficient vascularization of the construct. A common approach consists of co-culture of endothelial cells and osteoblastic cells. This strategy uses cells from different sources and differentiation states, thus increasing the complexity upstream of a clinical application. The source of reparative cells is paramount for the success of bone tissue engineering applications. In this context, stem cells obtained from human bone marrow hold much promise. Here, we analyzed the potential of human whole bone marrow cells directly expanded in a three-dimensional (3D) polymer matrix and focused on the further characterization of this heterogeneous population and on their ability to promote angiogenesis and osteogenesis, both in vitro and in vivo, in a subcutaneous model. Cellular aggregates were formed within 24 h and over the 12-day culture period expressed endothelial and bone-specific markers and a specific junctional protein. Ectopic implantation of the tissue-engineered constructs revealed osteoid tissue and vessel formation both at the periphery and within the implant. This work sheds light on the potential clinical use of human whole bone marrow for bone regeneration strategies, focusing on a simplified approach to develop a direct 3D culture without two-dimensional isolation or expansion. PMID:25333855

  17. FRACTIONAL INTEGRATION TOOLBOX.

    PubMed

    Marinov, Toma M; Ramirez, Nelson; Santamaria, Fidel

    2013-09-01

    The problems formulated in the fractional calculus framework often require numerical fractional integration/differentiation of large data sets. Several existing fractional control toolboxes are capable of performing fractional calculus operations, however, none of them can efficiently perform numerical integration on multiple large data sequences. We developed a Fractional Integration Toolbox (FIT), which efficiently performs fractional numerical integration/differentiation of the Riemann-Liouville type on large data sequences. The toolbox allows parallelization and is designed to be deployed on both CPU and GPU platforms.

  18. Expanded Stem Cells, Stromal-Vascular Fraction, and Platelet-Rich Plasma Enriched Fat: Comparing Results of Different Facial Rejuvenation Approaches in a Clinical Trial

    PubMed Central

    Rigotti, Gino; Charles-de-Sá, Luiz; Gontijo-de-Amorim, Natale Ferreira; Takiya, Christina Maeda; Amable, Paola Romina; Borojevic, Radovan; Benati, Donatella; Bernardi, Paolo; Sbarbati, Andrea

    2016-01-01

    Background In a previous study, the authors demonstrated that treatment with expanded adipose-derived stem cells or stromal vascular fraction (SVF)-enriched fat modify the pattern of the dermis in human beings, representing a skin rejuvenation effect. Considering that expanded stem cells require a cell factor, the authors wanted to assess similar results by replacing them with platelet-rich plasma (PRP), which is easier to obtain and for which an empirical regenerative effect has been already described. Objectives To determine if PRP injection could replace the cutaneous regenerative effect of adipose-derived stem cells. Methods This study was performed in 13 patients who were candidates for facelift. The patients underwent sampling of fat by liposuction from the abdomen and submitted to one of three protocols: injection of SVF-enriched fat or expanded adipose-derived stem cells or fat plus PRP in the preauricular areas. Fragments of skin were removed before and 3 months after treatment and analyzed by optical and electron microscopy. Results The use of fat plus PRP led to the presence of more pronounced inflammatory infiltrates and a greater vascular reactivity, increasing in vascular permeability and a certain reactivity of the nervous component. The addition of PRP did not improve the regenerative effect. Conclusion The use of PRP did not have significant advantages in skin rejuvenation over the use of expanded adipose-derived stem cells or SVF-enriched fat. The effect of increased vascular reactivity may be useful in pathological situations in which an intense angiogenesis is desirable, such as tissular ischemia. Level of Evidence: 4 Therapeutic PMID:26879294

  19. A new approach to assess intracranial white matter abnormalities in glaucoma patients: changes of fractional anisotropy detected by 3T diffusion tensor imaging.

    PubMed

    Engelhorn, Tobias; Michelson, Georg; Waerntges, Simone; Hempel, Susanne; El-Rafei, Ahmed; Struffert, Tobias; Doerfler, Arnd

    2012-04-01

    The aims of this study was to evaluate, using 3-T diffusion tensor imaging, changes of fractional anisotropy (FA) in the orbital and intracranial part of the optic nerve (ON), the optic chiasm, the lateral geniculate nucleus, and different parts of the optic radiation (OR) in patients with glaucoma compared to controls and to determine whether FA correlates with disease severity. Twenty patients with glaucoma and 22 age-matched controls were examined using 3-T diffusion tensor imaging. Regions of interest were positioned on the FA maps, and mean values were calculated for each ON, optic chiasm, lateral geniculate nucleus, and OR. Results were compared to those from controls and correlated with ON atrophy and reduced spatial-temporal contrast sensitivity of the retina. Compared to controls, FA in patients with glaucoma was significantly lower in the intracranial part of the ON (0.48 ± 0.15 vs 0.66 ± 0.12, P < .05) and in the OR (0.40 ± 0.16 to 0.48 ± 0.17 vs 0.53 ± 0.20 to 0.64 ± 0.11, P < .05). A high correlation between reduced FA in the intracranial ON and OR and ON atrophy and spatial-temporal contrast sensitivity of the retina was observed (r > 0.81). Otherwise, there was no significant difference in FA between patients with glaucoma and controls measured in the orbital part of the ON, optic chiasm, and lateral geniculate nucleus. Diffusion tensor imaging at 3 T allows robust FA measurements in the intracranial part of the ON and the OR. FA is significantly reduced in patients with glaucoma compared to controls, with a good correlation with established ophthalmologic examinations. Copyright © 2012 AUR. Published by Elsevier Inc. All rights reserved.

  20. Developing a new simplified method to determine diffusive uptake rates of volatile organic compounds in workplaces based on a fractional factorial designs approach.

    PubMed

    Estève, Williams; Lhuillier, Francine; Ravera, Christel; Grzebyck, Michel; Langlois, Eddy

    2013-01-01

    Exposure to organic vapors in the workplace is a source of occupational risk. Admissible exposure levels are tightly regulated and must be closely monitored. However, the complexity and slowness of the existing complete protocols to determine diffusive uptake rates through passive sampling have limited the use of this tool despite obvious advantages. In this study, we experimentally validate two simplified protocols to determine diffusive uptake rates with passive sampling. The proposed 2(6-3) and 2(6-2) fractional factorial designs were validated for toluene sampling using a (Gas Adsorbent Badge for Individual Exposure) GABIE-activated charcoal sampler in a controlled atmosphere. The uptake rate for this sampler had been determined previously using a full protocol. The uptake rates for all three protocols were similar, indicating that the proposed new designs can be substituted for classical full protocols. After validation of our protocols, uptake rates for new substances used as fuel additives (methyl and ethyl tert-butyl ethers, MTBE and ETBE) were determined on the same sampler using the 2(6-2) design. In these experiments, temperature appears to have a non-negligible influence on the uptake rates measured for these compounds. With some precautions of usage (ambient temperature below a determined limit temperature or at least exposure time ≥4 h) and storage (storage temperature = 4°C) of the sampler, the experimental diffusive uptake rates determined by this method can be used with good confidence. Field experiments confirmed the experimental results, showing good agreement between active and passive sampling using the experimentally determined uptake rates.

  1. Expanded Stem Cells, Stromal-Vascular Fraction, and Platelet-Rich Plasma Enriched Fat: Comparing Results of Different Facial Rejuvenation Approaches in a Clinical Trial.

    PubMed

    Rigotti, Gino; Charles-de-Sá, Luiz; Gontijo-de-Amorim, Natale Ferreira; Takiya, Christina Maeda; Amable, Paola Romina; Borojevic, Radovan; Benati, Donatella; Bernardi, Paolo; Sbarbati, Andrea

    2016-03-01

    In a previous study, the authors demonstrated that treatment with expanded adipose-derived stem cells or stromal vascular fraction (SVF)-enriched fat modify the pattern of the dermis in human beings, representing a skin rejuvenation effect. Considering that expanded stem cells require a cell factor, the authors wanted to assess similar results by replacing them with platelet-rich plasma (PRP), which is easier to obtain and for which an empirical regenerative effect has been already described. To determine if PRP injection could replace the cutaneous regenerative effect of adipose-derived stem cells. This study was performed in 13 patients who were candidates for facelift. The patients underwent sampling of fat by liposuction from the abdomen and submitted to one of three protocols: injection of SVF-enriched fat or expanded adipose-derived stem cells or fat plus PRP in the preauricular areas. Fragments of skin were removed before and 3 months after treatment and analyzed by optical and electron microscopy. The use of fat plus PRP led to the presence of more pronounced inflammatory infiltrates and a greater vascular reactivity, increasing in vascular permeability and a certain reactivity of the nervous component. The addition of PRP did not improve the regenerative effect. The use of PRP did not have significant advantages in skin rejuvenation over the use of expanded adipose-derived stem cells or SVF-enriched fat. The effect of increased vascular reactivity may be useful in pathological situations in which an intense angiogenesis is desirable, such as tissular ischemia. © 2016 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  2. Carbohydrate intake, obesity, metabolic syndrome and cancer risk? A two-part systematic review and meta-analysis protocol to estimate attributability.

    PubMed

    Sartorius, B; Sartorius, K; Aldous, C; Madiba, T E; Stefan, C; Noakes, T

    2016-01-04

    Linkages between carbohydrates, obesity and cancer continue to demonstrate conflicting results. Evidence suggests inconclusive direct linkages between carbohydrates and specific cancers. Conversely, obesity has been strongly linked to a wide range of cancers. The purpose of the study is to explore linkages between carbohydrate intake and cancer types using a two-step approach. First the study will evaluate the linkages between carbohydrate intake and obesity, potentially stratified by metabolic syndrome status. Second, the estimated attributable fraction of obesity ascribed to carbohydrate intake will be multiplied against obesity attributable fractions for cancer types to give estimated overall attributable fraction for carbohydrate versus cancer type. We will perform a comprehensive search to identify all possible published and unpublished studies that have assessed risk factors for obesity including dietary carbohydrate intake. Scientific databases, namely PubMed MEDLINE, EMBASE, EBSCOhost and ISI Web of Science will be searched. Following study selection, paper/data acquisition, and data extraction and synthesis, we will appraise the quality of studies and risk of bias, as well as assess heterogeneity. Meta-weighted attributable fractions of obesity due to carbohydrate intake will be estimated after adjusting for other potential confounding factors (eg, physical inactivity, other dietary intake). Furthermore, previously published systematic reviews assessing the cancer-specific risk associated with obesity will also be drawn. These estimates will be linked with the attributability of carbohydrate intake in part 1 to estimate the cancer-specific burden that can be attributed to dietary carbohydrates. This systematic review protocol has been developed according to the 'Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) 2015'. The current study will be based on published literature and data, and, as such, ethics approval is not

  3. Use of Urine Biomarkers to Assess Sodium Intake: Challenges and Opportunities.

    PubMed

    Cogswell, Mary E; Maalouf, Joyce; Elliott, Paul; Loria, Catherine M; Patel, Sheena; Bowman, Barbara A

    2015-01-01

    This article summarizes current data and approaches to assess sodium intake in individuals and populations. A review of the literature on sodium excretion and intake estimation supports the continued use of 24-h urine collections for assessing population and individual sodium intake. Since 2000, 29 studies used urine biomarkers to estimate population sodium intake, primarily among adults. More than half used 24-h urine; the rest used a spot/casual, overnight, or 12-h specimen. Associations between individual sodium intake and health outcomes were investigated in 13 prospective cohort studies published since 2000. Only three included an indicator of long-term individual sodium intake, i.e., multiple 24-h urine specimens collected several days apart. Although not insurmountable, logistic challenges of 24-h urine collection remain a barrier for research on the relationship of sodium intake and chronic disease. Newer approaches, including modeling based on shorter collections, offer promise for estimating population sodium intake in some groups.

  4. Use of Urine Biomarkers to Assess Sodium Intake: Challenges and Opportunities

    PubMed Central

    Maalouf, Joyce; Elliott, Paul; Loria, Catherine M.; Patel, Sheena; Bowman, Barbara A.

    2017-01-01

    This article summarizes current data and approaches to assess sodium intake in individuals and populations. A review of the literature on sodium excretion and intake estimation supports the continued use of 24-h urine collections for assessing population and individual sodium intake. Since 2000, 29 studies used urine biomarkers to estimate population sodium intake, primarily among adults. More than half used 24-h urine; the rest used a spot/casual, overnight, or 12-h specimen. Associations between individual sodium intake and health outcomes were investigated in 13 prospective cohort studies published since 2000. Only three included an indicator of long-term individual sodium intake, i.e., multiple 24-h urine specimens collected several days apart. Although not insurmountable, logistic challenges of 24-h urine collection remain a barrier for research on the relationship of sodium intake and chronic disease. Newer approaches, including modeling based on shorter collections, offer promise for estimating population sodium intake in some groups. PMID:25974702

  5. Meaning of Fractions

    NASA Astrophysics Data System (ADS)

    Dewi, D. A. K.; Suryadi, D.; Suratno, T.; Mulyana, E.; Kurniawan, H.

    2017-02-01

    Introducing fractions is identical to divide an object. Suppose we divide the apple into two parts. One divided into two parts, the question arises whether one part can be called a half or not. Based on this activity, how can students give meaning to fractions. This study aims at designing a different fractions lesson by applying Didactical Design Research. In doing so, we undertook several research phases: 1) thinking what is fractions and why students should learn this concept; 2) designing didactical situation based on identified learning obstacles; and 3) reflecting retrospectively on the lesson design and its implementation as to redesign the fractions lesson. Our analysis revealed that most students held epistemological obstacles in giving meaning of fractions because they only know fractions as numbers that have numerator and denominator. By positioning ourselves as students, we discuss the ideal design to help students in constructing the meaning of fractions.

  6. Beverage caffeine intake in US consumers and subpopulations of interest: estimates from the Share of Intake Panel survey.

    PubMed

    Knight, C A; Knight, I; Mitchell, D C; Zepp, J E

    2004-12-01

    Concerns exist about the potential adverse health effects of high consumption of dietary caffeine, especially in children and pregnant women. Recommended caffeine intakes corresponding to no adverse health effects have been suggested recently for healthy adults (400-450 mg/day), for women contemplating pregnancy (300 mg/day), and for young children age 4-6 years (45 mg/day). To determine whether current caffeine intake approaches these levels, intake from major dietary sources (coffee, tea and carbonated soft drinks) were measured in 10,712 caffeinated beverage consumers in the 1999 US Share of Intake Panel, a targeted beverage survey. Mean caffeine intakes in adult caffeinated beverage consumers ranged from 106 to 170 mg/day (90th percentile intake was 227-382 mg/day). In children 1-5 and 6-9 years, mean caffeine intakes were 14 and 22 mg/day, respectively; corresponding 90th percentile intakes were 37 and 45 mg/day. Pregnant women consumed an average of 58 mg/day (157 mg/day at the 90th percentile), and women of reproductive age ingested 91-109 mg/day (229-247 mg/day at the 90th percentile). These data show that while mean caffeine intakes are within recommended safe levels, heavy consumers of certain subpopulations, including young children and women contemplating pregnancy, might benefit from dietary advice.

  7. Fractional characteristic times and dissipated energy in fractional linear viscoelasticity

    NASA Astrophysics Data System (ADS)

    Colinas-Armijo, Natalia; Di Paola, Mario; Pinnola, Francesco P.

    2016-08-01

    In fractional viscoelasticity the stress-strain relation is a differential equation with non-integer operators (derivative or integral). Such constitutive law is able to describe the mechanical behavior of several materials, but when fractional operators appear, the elastic and the viscous contribution are inseparable and the characteristic times (relaxation and retardation time) cannot be defined. This paper aims to provide an approach to separate the elastic and the viscous phase in the fractional stress-strain relation with the aid of an equivalent classical model (Kelvin-Voigt or Maxwell). For such equivalent model the parameters are selected by an optimization procedure. Once the parameters of the equivalent model are defined, characteristic times of fractional viscoelasticity are readily defined as ratio between viscosity and stiffness. In the numerical applications, three kinds of different excitations are considered, that is, harmonic, periodic, and pseudo-stochastic. It is shown that, for any periodic excitation, the equivalent models have some important features: (i) the dissipated energy per cycle at steady-state coincides with the Staverman-Schwarzl formulation of the fractional model, (ii) the elastic and the viscous coefficients of the equivalent model are strictly related to the storage and the loss modulus, respectively.

  8. Ablative and fractional ablative lasers.

    PubMed

    Brightman, Lori A; Brauer, Jeremy A; Anolik, Robert; Weiss, Elliot; Karen, Julie; Chapas, Anne; Hale, Elizabeth; Bernstein, Leonard; Geronemus, Roy G

    2009-10-01

    The field of nonsurgical laser resurfacing for aesthetic enhancement continues to improve with new research and technological advances. Since its beginnings in the 1980s, the laser-resurfacing industry has produced a multitude of devices employing ablative, nonablative, and fractional ablative technologies. The three approaches largely differ in their method of thermal damage, weighing degrees of efficacy, downtime, and side effect profiles against each other. Nonablative technologies generate some interest, although only for those patient populations seeking mild improvements. Fractional technologies, however, have gained dramatic ground on fully ablative resurfacing. Fractional laser resurfacing, while exhibiting results that fall just short of the ideal outcomes of fully ablative treatments, is an increasingly attractive alternative because of its far more favorable side effect profile, reduced recovery time, and significant clinical outcome.

  9. DIY Fraction Pack.

    ERIC Educational Resources Information Center

    Graham, Alan; Graham, Louise

    2003-01-01

    Describes a very successful attempt to teach fractions to year 5 pupils based on pupils making their own fraction pack. Children decided for themselves how to make the fractional slices used in the activity using colored cardboard sheets and templates of a paper circle consisting of 24 equal slices. (Author/NB)

  10. Unfolding Fraction Multiplication

    ERIC Educational Resources Information Center

    Wyberg, Terry; Whitney, Stephanie R.; Cramer, Kathleen A.; Monson, Debra S.; Leavitt, Seth

    2011-01-01

    Students often have difficulty understanding fractions, in general, and understanding how to multiply fractions, in particular. To move past this potential problem area, students need to develop a deeper understanding of multiplication and connect the ideas to fractions. In this article, the authors share their insights into teaching fraction…

  11. DIY Fraction Pack.

    ERIC Educational Resources Information Center

    Graham, Alan; Graham, Louise

    2003-01-01

    Describes a very successful attempt to teach fractions to year 5 pupils based on pupils making their own fraction pack. Children decided for themselves how to make the fractional slices used in the activity using colored cardboard sheets and templates of a paper circle consisting of 24 equal slices. (Author/NB)

  12. Demonstration of the utility of biomarkers for dietary intake assessment; proline betaine as an example.

    PubMed

    Gibbons, Helena; Michielsen, Charlotte J R; Rundle, Milena; Frost, Gary; McNulty, Breige A; Nugent, Anne P; Walton, Janette; Flynn, Albert; Gibney, Michael J; Brennan, Lorraine

    2017-10-01

    There is a dearth of studies demonstrating the use of dietary biomarkers for determination of food intake. The objective of this study was to develop calibration curves for use in quantifying citrus intakes in an independent cohort. Participants (n = 50) from the NutriTech food-intake study consumed standardized breakfasts for three consecutive days over three consecutive weeks. Orange juice intake decreased over the weeks. Urine samples were analyzed by NMR-spectroscopy and proline betaine was quantified and normalized to osmolality. Calibration curves were developed and used to predict citrus intake in an independent cohort; the Irish National Adult Nutrition Survey (NANS) (n = 565). Proline betaine displayed a dose-response relationship to orange juice intake in 24 h and fasting samples (p < 0.001). In a test set, predicted orange juice intakes displayed excellent agreement with true intake. There were significant associations between predicted intake measured in 24 h and fasting samples and true intake (r = 0.710-0.919). Citrus intakes predicted for the NANS cohort demonstrated good agreement with self-reported intake and this agreement improved following normalization to osmolality. The developed calibration curves successfully predicted citrus intakes in an independent cohort. Expansion of this approach to other foods will be important for the development of objective intake measurements. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Homotopy analysis method for fractional IVPs

    NASA Astrophysics Data System (ADS)

    Hashim, I.; Abdulaziz, O.; Momani, S.

    2009-03-01

    In this paper, the homotopy analysis method is applied to solve linear and nonlinear fractional initial-value problems (fIVPs). The fractional derivatives are described by Caputo's sense. Exact and/or approximate analytical solutions of the fIVPs are obtained. The results of applying this procedure to the studied cases show the high accuracy and efficiency of the approach.

  14. Pitch fractionation. Technical report

    SciTech Connect

    Weinberg, V.L.; White, J.L.

    1981-12-15

    Petroleum pitch (Ashland A240) has been subjected to thermal treatment and solvent fractionation to produce refined pitches to be evaluated as impregnants for carbon-carbon composites. The solvent fractions were obtained by sequential Soxhlet extraction with solvents such as hexane, cyclohexane, toluene, and pyridine. The most severe thermal treatment produced a mesophase pitch (approximately 50% mesophase); an appreciable portion of the mesophase was soluble in strong solvents. There were substantial differences in chemical composition and in pyrolysis behavior of the fractions. As the depth of fraction increased, the pyrolysis yield and bloating increased, and the microstructure of the coke became finer until glassy microconstituents were formed in the deepest fractions.

  15. Application of DoE approach in the development of mini-capsules, based on biopolymers and manuka honey polar fraction, as powder formulation for the treatment of skin ulcers.

    PubMed

    Tenci, Marika; Rossi, Silvia; Bonferoni, Maria Cristina; Sandri, Giuseppina; Mentori, Irene; Boselli, Cinzia; Cornaglia, Antonia Icaro; Daglia, Maria; Marchese, Anna; Caramella, Carla; Ferrari, Franca

    2017-01-10

    The aim of the present work was the development of a powder formulation for the delivery of manuka honey (MH) bioactive components in the treatment of chronic skin ulcers. In particular pectin (PEC)/chitosan glutamate (CS)/hyaluronic acid (HA) mini-capsules were obtained by inverse ionotropic gelation in presence of calcium chloride and subsequently freeze-dried. Optimization of unloaded (blank) formulation was performed using DoE approach. In a screening phase, the following three factors were investigated at two levels: CS (0.5-1% w/w), PEC (0.5-1% w/w) and HA (0.3-0.5% w/w) concentrations. For the optimization phase a "central composite design" was used. The response variables considered were: particle size, buffer (PBS) absorption and mechanical resistance. In a previously work two different MH fractions were investigated, in particular MH fraction 1 (Fr1), rich in polar substances (sugars, methylglyoxal (MGO), dicarbonyl compounds, …), was able to enhance human fibroblasts in vitro proliferation. In the present work, the loading of MH Fr1 into mini-capsules of optimized composition determined a significant increase in cell proliferation in comparison with the unloaded ones. Loaded particles showed antimicrobial activity against Staphylococcus aureus and Streptococcus pyogenes; they were also able to improve wound healing in vivo on a rat wound model. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Fractional quantum Hall effect revisited

    NASA Astrophysics Data System (ADS)

    Jacak, J.; Łydżba, P.; Jacak, L.

    2015-10-01

    The topology-based explanation of the fractional quantum Hall effect (FQHE) is summarized. The cyclotron braid subgroups crucial for this approach are introduced in order to identify the origin of the Laughlin correlations in 2D (two-dimensional) Hall systems. Flux-tubes and vortices for composite fermions in their standard constructions are explained in terms of cyclotron braids. The derivation of the hierarchy of the FQHE is proposed by mapping onto the integer effect within the topology-based approach. The experimental observations of the FQHE supporting the cyclotron braid picture are reviewed with a special attention paid to recent experiments with a suspended graphene. The triggering role of a carrier mobility for organization of the fractional state in Hall configuration is emphasized. The prerequisites for the FQHE are indicated including topological conditions substantially increasing the previously accepted set of physical necessities. The explanation of numerical studies by exact diagonalizations of the fractional Chern insulator states is formulated in terms of the topology condition applied to the Berry field flux quantization. Some new ideas withz regard to the synthetic fractional states in the optical lattices are also formulated.

  17. Obesity: Interactions of Genome and Nutrients Intake

    PubMed Central

    Doo, Miae; Kim, Yangha

    2015-01-01

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

  18. First applications of a targeted exome sequencing approach in fetuses with ultrasound abnormalities reveals an important fraction of cases with associated gene defects.

    PubMed

    Pangalos, Constantinos; Hagnefelt, Birgitta; Lilakos, Konstantinos; Konialis, Christopher

    2016-01-01

    Background. Fetal malformations and other structural abnormalities are relatively frequent findings in the course of routine prenatal ultrasonographic examination. Due to their considerable genetic and clinical heterogeneity, the underlying genetic cause is often elusive and the resulting inability to provide a precise diagnosis precludes proper reproductive and fetal risk assessment. We report the development and first applications of an expanded exome sequencing-based test, coupled to a bioinformatics-driven prioritization algorithm, targeting gene disorders presenting with abnormal prenatal ultrasound findings. Methods. We applied the testing strategy to14 euploid fetuses, from 11 on-going pregnancies and three products of abortion, all with various abnormalities or malformations detected through prenatal ultrasound examination. Whole exome sequencing (WES) was followed by variant prioritization, utilizing a custom analysis pipeline (Fetalis algorithm), targeting 758 genes associated with genetic disorders which may present with abnormal fetal ultrasound findings. Results. A definitive or highly-likely diagnosis was made in 6 of 14 cases (43%), of which 3 were abortuses (Ellis-van Creveld syndrome, Ehlers-Danlos syndrome and Nemaline myopathy 2) and 3 involved on-going pregnancies (Citrullinemia, Noonan syndrome, PROKR2-related Kallmann syndrome). In the remaining eight on-going pregnancy cases (57%), a ZIC1 variant of unknown clinical significance was detected in one case, while in seven cases testing did not reveal any pathogenic variant(s). Pregnancies were followed-up to birth, resulting in one neonate harboring the PROKR2 mutation, presenting with isolated minor structural cardiac abnormalities, and in seven apparently healthy neonates. Discussion. The expanded targeted exome sequencing-based approach described herein (Fetalis), provides strong evidence suggesting a definite and beneficial increase in our diagnostic capabilities in prenatal diagnosis of

  19. A metabolomic study of biomarkers of meat and fish intake.

    PubMed

    Cheung, William; Keski-Rahkonen, Pekka; Assi, Nada; Ferrari, Pietro; Freisling, Heinz; Rinaldi, Sabina; Slimani, Nadia; Zamora-Ros, Raul; Rundle, Milena; Frost, Gary; Gibbons, Helena; Carr, Eibhlin; Brennan, Lorraine; Cross, Amanda J; Pala, Valeria; Panico, Salvatore; Sacerdote, Carlotta; Palli, Domenico; Tumino, Rosario; Kühn, Tilman; Kaaks, Rudolf; Boeing, Heiner; Floegel, Anna; Mancini, Francesca; Boutron-Ruault, Marie-Christine; Baglietto, Laura; Trichopoulou, Antonia; Naska, Androniki; Orfanos, Philippos; Scalbert, Augustin

    2017-03-01

    Background: Meat and fish intakes have been associated with various chronic diseases. The use of specific biomarkers may help to assess meat and fish intake and improve subject classification according to the amount and type of meat or fish consumed.Objective: A metabolomic approach was applied to search for biomarkers of meat and fish intake in a dietary intervention study and in free-living subjects from the European Prospective Investigation into Cancer and Nutrition (EPIC) study.Design: In the dietary intervention study, 4 groups of 10 subjects consumed increasing quantities of chicken, red meat, processed meat, and fish over 3 successive weeks. Twenty-four-hour urine samples were collected during each period and analyzed by high-resolution liquid chromatography-mass spectrometry. Signals characteristic of meat or fish intake were replicated in 50 EPIC subjects for whom a 24-h urine sample and 24-h dietary recall were available and who were selected for their exclusive intake or no intake of any of the 4 same foods.Results: A total of 249 mass spectrometric features showed a positive dose-dependent response to meat or fish intake in the intervention study. Eighteen of these features best predicted intake of the 4 food groups in the EPIC urine samples on the basis of partial receiver operator curve analyses with permutation testing (areas under the curve ranging between 0.61 and 1.0). Of these signals, 8 metabolites were identified. Anserine was found to be specific for chicken intake, whereas trimethylamine-N-oxide showed good specificity for fish. Carnosine and 3 acylcarnitines (acetylcarnitine, propionylcarnitine, and 2-methylbutyrylcarnitine) appeared to be more generic indicators of meat and meat and fish intake, respectively.Conclusion: The meat and fish biomarkers identified in this work may be used to study associations between meat and fish intake and disease risk in epidemiologic studies. This trial was registered at clinicaltrials.gov as NCT01684917.

  20. First applications of a targeted exome sequencing approach in fetuses with ultrasound abnormalities reveals an important fraction of cases with associated gene defects

    PubMed Central

    Pangalos, Constantinos; Hagnefelt, Birgitta; Lilakos, Konstantinos

    2016-01-01

    Background. Fetal malformations and other structural abnormalities are relatively frequent findings in the course of routine prenatal ultrasonographic examination. Due to their considerable genetic and clinical heterogeneity, the underlying genetic cause is often elusive and the resulting inability to provide a precise diagnosis precludes proper reproductive and fetal risk assessment. We report the development and first applications of an expanded exome sequencing-based test, coupled to a bioinformatics-driven prioritization algorithm, targeting gene disorders presenting with abnormal prenatal ultrasound findings. Methods. We applied the testing strategy to14 euploid fetuses, from 11 on-going pregnancies and three products of abortion, all with various abnormalities or malformations detected through prenatal ultrasound examination. Whole exome sequencing (WES) was followed by variant prioritization, utilizing a custom analysis pipeline (Fetalis algorithm), targeting 758 genes associated with genetic disorders which may present with abnormal fetal ultrasound findings. Results. A definitive or highly-likely diagnosis was made in 6 of 14 cases (43%), of which 3 were abortuses (Ellis-van Creveld syndrome, Ehlers-Danlos syndrome and Nemaline myopathy 2) and 3 involved on-going pregnancies (Citrullinemia, Noonan syndrome, PROKR2-related Kallmann syndrome). In the remaining eight on-going pregnancy cases (57%), a ZIC1 variant of unknown clinical significance was detected in one case, while in seven cases testing did not reveal any pathogenic variant(s). Pregnancies were followed-up to birth, resulting in one neonate harboring the PROKR2 mutation, presenting with isolated minor structural cardiac abnormalities, and in seven apparently healthy neonates. Discussion. The expanded targeted exome sequencing-based approach described herein (Fetalis), provides strong evidence suggesting a definite and beneficial increase in our diagnostic capabilities in prenatal diagnosis of

  1. Sodium intake and cardiovascular health.

    PubMed

    O'Donnell, Martin; Mente, Andrew; Yusuf, Salim

    2015-03-13

    Sodium is an essential nutrient. Increasing sodium intake is associated with increasing blood pressure, whereas low sodium intake results in increased renin and aldosterone levels. Randomized controlled trials have reported reductions in blood pressure with reductions in sodium intake, to levels of sodium intake <1.5 g/d, and form the evidentiary basis for current population-wide guidelines recommending low sodium intake. Although low sodium intake (<2.0 g/d) has been achieved in short-term feeding clinical trials, sustained low sodium intake has not been achieved by any of the longer term clinical trials (>6-month duration). It is assumed that the blood pressure-lowering effects of reducing sodium intake to low levels will result in large reductions in cardiovascular disease globally. However, current evidence from prospective cohort studies suggests a J-shaped association between sodium intake and cardiovascular events, based on studies from >300 000 people, and suggests that the lowest risk of cardiovascular events and death occurs in populations consuming an average sodium intake range (3-5 g/d). The increased risk of cardiovascular events associated with higher sodium intake (>5 g/d) is most prominent in those with hypertension. A major deficit in the field is the absence of large randomized controlled trials to provide definitive evidence on optimal sodium intake for preventing cardiovascular events. Pending such trials, current evidence would suggest a recommendation for moderate sodium intake in the general population (3-5 g/d), with targeting the lower end of the moderate range among those with hypertension.

  2. Fractional viscoelastic beam under torsion

    NASA Astrophysics Data System (ADS)

    Colinas-Armijo, N.; Cutrona, S.; Di Paola, M.; Pirrotta, A.

    2017-07-01

    This paper introduces a study on twisted viscoelastic beams, having considered fractional calculus to capture the viscoelastic behaviour. Further another novelty of this paper is extending a recent numerical approach, labelled line elementless method (LEM), to viscoelastic beams. The latter does not require any discretization neither in the domain nor in the boundary. Some numerical applications have been reported to demonstrate the efficiency and accuracy of the method.

  3. Dividing Fractions: A Pedagogical Technique

    ERIC Educational Resources Information Center

    Lewis, Robert

    2016-01-01

    When dividing one fraction by a second fraction, invert, that is, flip the second fraction, then multiply it by the first fraction. To multiply fractions, simply multiply across the denominators, and multiply across the numerators to get the resultant fraction. So by inverting the division of fractions it is turned into an easy multiplication of…

  4. Dividing Fractions: A Pedagogical Technique

    ERIC Educational Resources Information Center

    Lewis, Robert

    2016-01-01

    When dividing one fraction by a second fraction, invert, that is, flip the second fraction, then multiply it by the first fraction. To multiply fractions, simply multiply across the denominators, and multiply across the numerators to get the resultant fraction. So by inverting the division of fractions it is turned into an easy multiplication of…

  5. Risk assessment for polycyclic aromatic hydrocarbon NAPLs using component fractions

    SciTech Connect

    Brown, D.G.; Knightes, C.D.; Peters, C.A.

    1999-12-15

    This paper presents an alternative method for characterizing PAH NAPLs that is based on the fraction approach developed by the Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG). The fraction approach characterizes the PAH NAPL as a collection of US EPA Priority Pollutants plus hydrocarbon fractions. This approach allows prediction of the NAPL compositional dynamics while retaining some of the simplified analysis of a lumped parameter approach. The fractions and priority pollutants are modeled as NAPL components for performing risks assessments and assessing the potential of remediation strategies. This makes the fraction approach amenable for use in a Risk-Based Corrective Action (RBCA) framework. In this work, the TPHCWG fraction approach was modified for description of NAPL constituents that are solids in their pure states. This was accomplished by assigning an equivalent solid-liquid reference fugacity ratio for each fraction. Thirty-year simulations with two model coal tars are presented, comparing the risk calculations for the fraction approach to those accounting for the complete NAPL composition. These simulations show that the model using the fraction approach predicts similar NAPL compositional dynamics and PAH carcinogenic risk as the model describing all the compounds. Use of the fraction approach at PAH NAPL sites will allow a more accurate accounting of the risk variation than the TPH approach. Additionally, it will emphasize development and use of remediation methods that address risk reduction, not just the reduction in total contaminant mass.

  6. Global patterns of water intake: how intake data affect recommendations.

    PubMed

    Shirreffs, Susan M

    2012-11-01

    Studies to assess water intake have been undertaken in many countries around the world. Some of these have been large-scale studies, whereas others have used a small number of subjects. These studies provide an emerging picture of water and/or fluid consumption in different populations around the world. Studies of this nature have also formed the basis of a number of recommendations published by different organizations, including the US Institute of Medicine and the European Food Safety Authority. The results of these intake studies indicate substantial differences in water and/or fluid intake in different populations, which have translated into different intake recommendations.

  7. Dietary intake of artificial sweeteners by the Belgian population.

    PubMed

    Huvaere, Kevin; Vandevijvere, Stefanie; Hasni, Moez; Vinkx, Christine; Van Loco, Joris

    2012-01-01

    This study investigated whether the Belgian population older than 15 years is at risk of exceeding ADI levels for acesulfame-K, saccharin, cyclamate, aspartame and sucralose through an assessment of usual dietary intake of artificial sweeteners and specific consumption of table-top sweeteners. A conservative Tier 2 approach, for which an extensive label survey was performed, showed that mean usual intake was significantly lower than the respective ADIs for all sweeteners. Even consumers with high intakes were not exposed to excessive levels, as relative intakes at the 95th percentile (p95) were 31% for acesulfame-K, 13% for aspartame, 30% for cyclamate, 17% for saccharin, and 16% for sucralose of the respective ADIs. Assessment of intake using a Tier 3 approach was preceded by optimisation and validation of an analytical method based on liquid chromatography with mass spectrometric detection. Concentrations of sweeteners in various food matrices and table-top sweeteners were determined and mean positive concentration values were included in the Tier 3 approach, leading to relative intakes at p95 of 17% for acesulfame-K, 5% for aspartame, 25% for cyclamate, 11% for saccharin, and 7% for sucralose of the corresponding ADIs. The contribution of table-top sweeteners to the total usual intake (<1% of ADI) was negligible. A comparison of observed intake for the total population with intake for diabetics (acesulfame-K: 3.55 versus 3.75; aspartame: 6.77 versus 6.53; cyclamate: 1.97 versus 2.06; saccharine: 1.14 versus 0.97; sucralose: 3.08 versus 3.03, expressed as mg kg(-1) bodyweight day(-1) at p95) showed that the latter group was not exposed to higher levels. It was concluded that the Belgian population is not at risk of exceeding the established ADIs for sweeteners.

  8. Protein Secondary Structures (alpha-helix and beta-sheet) at a Cellular Levle and Protein Fractions in Relation to Rumen Degradation Behaviours of Protein: A New Approach

    SciTech Connect

    Yu,P.

    2007-01-01

    Studying the secondary structure of proteins leads to an understanding of the components that make up a whole protein, and such an understanding of the structure of the whole protein is often vital to understanding its digestive behaviour and nutritive value in animals. The main protein secondary structures are the {alpha}-helix and {beta}-sheet. The percentage of these two structures in protein secondary structures influences protein nutritive value, quality and digestive behaviour. A high percentage of {beta}-sheet structure may partly cause a low access to gastrointestinal digestive enzymes, which results in a low protein value. The objectives of the present study were to use advanced synchrotron-based Fourier transform IR (S-FTIR) microspectroscopy as a new approach to reveal the molecular chemistry of the protein secondary structures of feed tissues affected by heat-processing within intact tissue at a cellular level, and to quantify protein secondary structures using multicomponent peak modelling Gaussian and Lorentzian methods, in relation to protein digestive behaviours and nutritive value in the rumen, which was determined using the Cornell Net Carbohydrate Protein System. The synchrotron-based molecular chemistry research experiment was performed at the National Synchrotron Light Source at Brookhaven National Laboratory, US Department of Energy. The results showed that, with S-FTIR microspectroscopy, the molecular chemistry, ultrastructural chemical make-up and nutritive characteristics could be revealed at a high ultraspatial resolution ({approx}10 {mu}m). S-FTIR microspectroscopy revealed that the secondary structure of protein differed between raw and roasted golden flaxseeds in terms of the percentages and ratio of {alpha}-helixes and {beta}-sheets in the mid-IR range at the cellular level. By using multicomponent peak modelling, the results show that the roasting reduced (P <0.05) the percentage of {alpha}-helixes (from 47.1% to 36.1%: S

  9. Evaluating fractionated space systems - Status

    NASA Astrophysics Data System (ADS)

    Cornford, S.; Jenkins, S.; Wall, S.; Cole, B.; Bairstow, B.; Rouquette, N.; Dubos, G.; Ryan, T.; Zarifian, P.; Boutwell, J.

    DARPA has funded a number of teams to further refine its Fractionated Spacecraft vision. Several teams, including this team led by JPL, have been tasked to develop a tool for the evaluation of the Business case for a fractionated system architecture. This evaluation is to understand under what conditions and constraints the fractionated architecture make more sense (in a cost/benefit sense) than the traditional monolithic paradigm. Our approach to this evaluation is to generate and evaluate a variety of trade space options. These options include various sets of stimuli, various degrees of fractionation and various subsystem element properties. The stimuli include many not normally modeled such as technology obsolescence, funding profile changes and changes in mission objectives during the mission itself. The degrees of fractionation enable various traditional subsystem elements to be distributed across different free flyers which then act in concert as needed. This will enable key technologies to be updated as need dictates and availability allows. We have described our approach in a previous IEEE Aerospace conference paper but will briefly summarize here. Our approach to generate the Business Case evaluation is to explicitly model both the implementation and operation phases for the life cycle of a fractionated constellation. A variety of models are integrated into the Phoenix ModelCenter framework and are used to generate various intermediate data which is aggregated into the Present Strategic Value (PSV). The PSV is essentially the value (including the value of the embedded real options) minus the cost. These PSVs are calculated for a variety of configurations and scenarios including variations of various stimuli or uncertainties (e.g. supply chain delays, launch vehicle failures and orbital debris events). There are various decision options (e.g. delay, accelerate, cancel) which can now be exercised for each stimulus. We can compute the PSV for the various comb

  10. Dietary intake and nutritional status.

    PubMed

    Ahn, Jiyoung; Abnet, Christian C; Cross, Amanda J; Sinha, Rashmi

    2011-01-01

    Though dietary factors are implicated in chronic disease risk, assessment of dietary intake has limitations, including problems with recall of complex food intake patterns over a long period of time. Diet and nutrient biomarkers may provide objective measures of dietary intake and nutritional status, as well as an integrated measure of intake, absorption and metabolism. Thus, the search for an unbiased biomarker of dietary intake and nutritional status is an important aspect of nutritional epidemiology. This chapter reviews types of biomarkers related to dietary intake and nutritional status, such as exposure biomarkers of diet and nutritional status, intermediate endpoints, and susceptibility. Novel biomarkers, such as biomarkers of physical fitness, oxidative DNA damage and tissue concentrations are also discussed.

  11. FRACTIONAL PEARSON DIFFUSIONS.

    PubMed

    Leonenko, Nikolai N; Meerschaert, Mark M; Sikorskii, Alla

    2013-07-15

    Pearson diffusions are governed by diffusion equations with polynomial coefficients. Fractional Pearson diffusions are governed by the corresponding time-fractional diffusion equation. They are useful for modeling sub-diffusive phenomena, caused by particle sticking and trapping. This paper provides explicit strong solutions for fractional Pearson diffusions, using spectral methods. It also presents stochastic solutions, using a non-Markovian inverse stable time change.

  12. FRACTIONAL PEARSON DIFFUSIONS

    PubMed Central

    Leonenko, Nikolai N.; Meerschaert, Mark M.

    2013-01-01

    Pearson diffusions are governed by diffusion equations with polynomial coefficients. Fractional Pearson diffusions are governed by the corresponding time-fractional diffusion equation. They are useful for modeling sub-diffusive phenomena, caused by particle sticking and trapping. This paper provides explicit strong solutions for fractional Pearson diffusions, using spectral methods. It also presents stochastic solutions, using a non-Markovian inverse stable time change. PMID:23626377

  13. Carbohydrate intake and obesity.

    PubMed

    van Dam, R M; Seidell, J C

    2007-12-01

    The prevalence of obesity has increased rapidly worldwide and the importance of considering the role of diet in the prevention and treatment of obesity is widely acknowledged. This paper reviews data on the effects of dietary carbohydrates on body fatness. Does the composition of the diet as related to carbohydrates affect the likelihood of passive over-consumption and long-term weight change? In addition, methodological limitations of both observational and experimental studies of dietary composition and body weight are discussed. Carbohydrates are among the macronutrients that provide energy and can thus contribute to excess energy intake and subsequent weight gain. There is no clear evidence that altering the proportion of total carbohydrate in the diet is an important determinant of energy intake. However, there is evidence that sugar-sweetened beverages do not induce satiety to the same extent as solid forms of carbohydrate, and that increases in sugar-sweetened soft drink consumption are associated with weight gain. Findings from studies on the effect of the dietary glycemic index on body weight have not been consistent. Dietary fiber is associated with a lesser degree of weight gain in observational studies. Although it is difficult to establish with certainty that fiber rather than other dietary attributes are responsible, whole-grain cereals, vegetables, legumes and fruits seem to be the most appropriate sources of dietary carbohydrate.

  14. Antenatal calcium intake in Malaysia.

    PubMed

    Mahdy, Zaleha Abdullah; Basri, Hashimah; Md Isa, Zaleha; Ahmad, Shuhaila; Shamsuddin, Khadijah; Mohd Amin, Rahmah

    2014-04-01

    To determine the adequacy of antenatal calcium intake in Malaysia, and the influencing factors. A cross-sectional study was conducted among postnatal women who delivered in two tertiary hospitals. Data were collected from antenatal cards, hospital documents and diet recall on daily milk and calcium intake during pregnancy. SPSS version 19.0 was used for statistical analyses. A total of 150 women were studied. The total daily calcium intake was 834 ± 43 mg (mean ± standard error of the mean), but the calcium intake distribution curve was skewed to the right with a median intake of 725 mg daily. When calcium intake from milk and calcium supplements was excluded, the daily dietary calcium intake was only 478 ± 25 mg. Even with inclusion of milk and calcium supplements, more than a third (n=55 or 36.7%) of the women consumed less than 600 mg calcium in their daily diet. The adequacy of daily calcium intake was not influenced by maternal age, ethnicity, income or maternal job or educational status as well as parity. The daily dietary calcium intake of the Malaysian antenatal population is far from adequate without the addition of calcium supplements and milk. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.

  15. [Dietary reference intakes of phosphorus].

    PubMed

    Uenishi, Kazuhiro

    2012-10-01

    Phosphorus (P) exists at the all organs and plays important physiological roles in the body. A wide range of food contains P, which is absorbed at a higher level (60-70%) and its insufficiency and deficiency are rarely found. P is used as food additives in many processed food, where risk of overconsumption could be an issue. P has less evidence in terms of nutrition. P has the adequate intake and the tolerable upper intake level, for risk reduction of health disorders associated with excess intake, at the Dietary Reference Intakes for Japanese (2010 edition).

  16. Automated segmentation of the lamina cribrosa using Frangi's filter: a novel approach for rapid identification of tissue volume fraction and beam orientation in a trabeculated structure in the eye.

    PubMed

    Campbell, Ian C; Coudrillier, Baptiste; Mensah, Johanne; Abel, Richard L; Ethier, C Ross

    2015-03-06

    The lamina cribrosa (LC) is a tissue in the posterior eye with a complex trabecular microstructure. This tissue is of great research interest, as it is likely the initial site of retinal ganglion cell axonal damage in glaucoma. Unfortunately, the LC is difficult to access experimentally, and thus imaging techniques in tandem with image processing have emerged as powerful tools to study the microstructure and biomechanics of this tissue. Here, we present a staining approach to enhance the contrast of the microstructure in micro-computed tomography (micro-CT) imaging as well as a comparison between tissues imaged with micro-CT and second harmonic generation (SHG) microscopy. We then apply a modified version of Frangi's vesselness filter to automatically segment the connective tissue beams of the LC and determine the orientation of each beam. This approach successfully segmented the beams of a porcine optic nerve head from micro-CT in three dimensions and SHG microscopy in two dimensions. As an application of this filter, we present finite-element modelling of the posterior eye that suggests that connective tissue volume fraction is the major driving factor of LC biomechanics. We conclude that segmentation with Frangi's filter is a powerful tool for future image-driven studies of LC biomechanics.

  17. Automated segmentation of the lamina cribrosa using Frangi's filter: a novel approach for rapid identification of tissue volume fraction and beam orientation in a trabeculated structure in the eye

    PubMed Central

    Campbell, Ian C.; Coudrillier, Baptiste; Mensah, Johanne; Abel, Richard L.; Ethier, C. Ross

    2015-01-01

    The lamina cribrosa (LC) is a tissue in the posterior eye with a complex trabecular microstructure. This tissue is of great research interest, as it is likely the initial site of retinal ganglion cell axonal damage in glaucoma. Unfortunately, the LC is difficult to access experimentally, and thus imaging techniques in tandem with image processing have emerged as powerful tools to study the microstructure and biomechanics of this tissue. Here, we present a staining approach to enhance the contrast of the microstructure in micro-computed tomography (micro-CT) imaging as well as a comparison between tissues imaged with micro-CT and second harmonic generation (SHG) microscopy. We then apply a modified version of Frangi's vesselness filter to automatically segment the connective tissue beams of the LC and determine the orientation of each beam. This approach successfully segmented the beams of a porcine optic nerve head from micro-CT in three dimensions and SHG microscopy in two dimensions. As an application of this filter, we present finite-element modelling of the posterior eye that suggests that connective tissue volume fraction is the major driving factor of LC biomechanics. We conclude that segmentation with Frangi's filter is a powerful tool for future image-driven studies of LC biomechanics. PMID:25589572

  18. Procedure for developing biological input for the design, location, or modification of water-intake structures

    SciTech Connect

    Neitzel, D.A.; McKenzie, D.H.

    1981-12-01

    To minimize adverse impact on aquatic ecosystems resulting from the operation of water intake structures, design engineers must have relevant information on the behavior, physiology and ecology of local fish and shellfish. Identification of stimulus/response relationships and the environmental factors that influence them is the first step in incorporating biological information in the design, location or modification of water intake structures. A procedure is presented in this document for providing biological input to engineers who are designing, locating or modifying a water intake structure. The authors discuss sources of stimuli at water intakes, historical approaches in assessing potential/actual impact and review biological information needed for intake design.

  19. Dietary intake of schoolchildren and adolescents in developing countries.

    PubMed

    Ochola, Sophie; Masibo, Peninah Kinya

    2014-01-01

    School age and adolescence is a dynamic period of growth and development forming a strong foundation for good health and productive adult life. Appropriate dietary intake is critical for forming good eating habits and provides the much needed nutrients for growth, long-term health, cognition and educational achievements. A large proportion of the population globally is in the school age or adolescence, with more than three quarters of these groups living in developing countries. An up-to-date review and discussion of the dietary intake of schoolchildren and adolescents in developing countries is suitable to provide recent data on patterns of dietary intake, adequacy of nutrient intake and their implications for public health and nutrition issues of concern. This review is based on literature published from 2000 to 2014 on dietary intake of schoolchildren and adolescents aged 6-19 years. A total of 50 studies from 42 countries reporting on dietary intake of schoolchildren and adolescents were included. The dietary intake of schoolchildren and adolescents in developing countries is limited in diversity, mainly comprising plant-based food sources, but with limited intake of fruits and vegetables. There is a low energy intake and insufficient micronutrient intake. At the same time, the available data indicate an emerging trend of consumption of high-energy snacks and beverages, particularly in urban areas. The existence of a negative and positive energy balance in the same population points to the dual burden of malnutrition and highlights the emerging nutrition transition in developing countries. This observation is important for planning public health nutrition approaches that address the concerns of the two ends of the nutrition divide. © 2014 S. Karger AG, Basel.

  20. An Appetite for Fractions

    ERIC Educational Resources Information Center

    Wilkerson, Trena L.; Bryan, Tommy; Curry, Jane

    2012-01-01

    This article describes how using candy bars as models gives sixth-grade students a taste for learning to represent fractions whose denominators are factors of twelve. Using paper models of the candy bars, students explored and compared fractions. They noticed fewer different representations for one-third than for one-half. The authors conclude…

  1. Paper Folding Fractions

    ERIC Educational Resources Information Center

    Pagni, David

    2007-01-01

    In this article, the author presents a paper folding activity that can be used for teaching fractions. This activity can be used to describe areas of folded polygons in terms of a standard unit of measure. A paper folding fractions worksheet and its corresponding solutions are also presented in this article. (Contains 2 figures.)

  2. The Future of Fractions

    ERIC Educational Resources Information Center

    Usiskin, Zalman P.

    2007-01-01

    In the 1970s, the movement to the metric system (which has still not completely occurred in the United States) and the advent of hand-held calculators led some to speculate that decimal representation of numbers would render fractions obsolete. This provocative proposition stimulated Zalman Usiskin to write "The Future of Fractions" in 1979. He…

  3. On fractional programming

    SciTech Connect

    Bajona-Xandri, C.; Martinez-Legaz, J.E.

    1994-12-31

    This paper studies the minimax fractional programming problem, assuming quasiconvexity of the objective function, under the lower subdifferentiability viewpoint. Necessary and sufficient optimality conditions and dual properties are found. We present applications of this theory to find the Pareto efficient solutions of a multiobjective fractional problem and to solve several economic models.

  4. An Appetite for Fractions

    ERIC Educational Resources Information Center

    Wilkerson, Trena L.; Bryan, Tommy; Curry, Jane

    2012-01-01

    This article describes how using candy bars as models gives sixth-grade students a taste for learning to represent fractions whose denominators are factors of twelve. Using paper models of the candy bars, students explored and compared fractions. They noticed fewer different representations for one-third than for one-half. The authors conclude…

  5. Can Kindergartners Do Fractions?

    ERIC Educational Resources Information Center

    Cwikla, Julie

    2014-01-01

    Mathematics professor Julie Cwikla decided that she needed to investigate young children's understandings and see what precurricular partitioning notions young minds bring to the fraction table. Cwikla realized that only a handful of studies have examined how preschool-age and early elementary school-age students solve fraction problems (Empson…

  6. (Carbon isotope fractionation inplants)

    SciTech Connect

    O'Leary, M.H.

    1990-01-01

    The objectives of this research are: To develop a theoretical and experimental framework for understanding isotope fractionations in plants; and to develop methods for using this isotope fractionation for understanding the dynamics of CO{sub 2} fixation in plants. Progress is described.

  7. Can Kindergartners Do Fractions?

    ERIC Educational Resources Information Center

    Cwikla, Julie

    2014-01-01

    Mathematics professor Julie Cwikla decided that she needed to investigate young children's understandings and see what precurricular partitioning notions young minds bring to the fraction table. Cwikla realized that only a handful of studies have examined how preschool-age and early elementary school-age students solve fraction problems (Empson…

  8. Fractional dissipative standard map.

    PubMed

    Tarasov, Vasily E; Edelman, M

    2010-06-01

    Using kicked differential equations of motion with derivatives of noninteger orders, we obtain generalizations of the dissipative standard map. The main property of these generalized maps, which are called fractional maps, is long-term memory. The memory effect in the fractional maps means that their present state of evolution depends on all past states with special forms of weights. Already a small deviation of the order of derivative from the integer value corresponding to the regular dissipative standard map (small memory effects) leads to the qualitatively new behavior of the corresponding attractors. The fractional dissipative standard maps are used to demonstrate a new type of fractional attractors in the wide range of the fractional orders of derivatives.

  9. Strategies to reduce dietary sodium intake.

    PubMed

    Cobb, Laura K; Appel, Lawrence J; Anderson, Cheryl A M

    2012-08-01

    Excess sodium intake has an important, if not predominant, role in the pathogenesis of elevated blood pressure, one of the most important modifiable determinants of cardiovascular disease (CVD). In the United States, almost 80 % of sodium in the diet comes from packaged and restaurant foods. Given the current food environment, educational efforts such as clinician counseling are useful, but a comprehensive public health approach is necessary to achieve meaningful reductions in sodium intake. A successful approach includes several key strategies, which together will both promote positive decisions by individuals and change the context in which they make those decisions. The strategies include 1) public education, 2) individual dietary counseling, 3) food labeling, 4) coordinated and voluntary industry sodium reduction, 5) government and private sector food procurement policies, and 6) FDA regulations, as recommended by the Institute of Medicine, to modify sodium's generally regarded as safe (GRAS) status. Population-wide reduction in sodium intake has the potential to substantially reduce the public burden of preventable CVD and reduce health care costs.

  10. Nutrient intake of Swiss toddlers.

    PubMed

    Brunner, Thomas A; Casetti, Luca; Haueter, Petra; Müller, Pascal; Nydegger, Andreas; Spalinger, Johannes

    2017-08-10

    During the first years of life, food preferences are shaped that might last throughout a person's entire life affecting his/her health in the long term. However, knowledge on early feeding habits is still limited for toddlers. Therefore, the goal of the present study was to: (1) assess toddlers' nutrient intake; (2) compare the findings to past studies as well as to national feeding recommendations and (3) identify major food sources for energy and macronutrients. A food survey using a 4-day diary was conducted. The dietary software nut.s(®) was used to analyse the data. A cohort of 188 healthy toddlers (aged 1-3 years) was analysed. The energy intake of most toddlers was below the recommended daily intake (RDI) but in accordance with earlier studies. Protein intake was three- to fourfold higher than the RDI and reached the proposed upper limit of 15% of total energy intake. Fat intake was in accordance with the RDI, but the balance of saturated and unsaturated fatty acids should be improved. Carbohydrate intake met the RDI. For the micronutrients, iron and vitamin D intakes showed critical values. As in other European countries, the diet of Swiss toddlers in general seems adequate but does not meet all nutritional requirements. In particular, the quality of the fats and vitamin D supplementation should be improved. For proteins and iron, additional research is needed to gain more confidence in the recommendations.

  11. Chapter 11: Dietary reference intakes

    USDA-ARS?s Scientific Manuscript database

    The Dietary Reference Intakes (DRI) are a set of recommendations intended to provide guidance in evaluating nutrient intakes and planning meals on the basis of nutrient adequacy. In contrast to their predecessor, Recommended Dietary Allowances last published in 1989, the DRIs differ in two ways: th...

  12. Vitamin K Intake and Atherosclerosis

    USDA-ARS?s Scientific Manuscript database

    It has been hypothesized that insufficient intake of vitamin K may increase soft tissue calcification due to impaired gamma-carboxylation of the vitamin K-dependent protein, matrix gamma-carboxyglutamic acid (MGP). The evidence to support this putative role of vitamin K intake in atherosclerosis is ...

  13. Limited Intervention at Sub Concept of Fractions in the Object Conversion into Fractions

    ERIC Educational Resources Information Center

    Kurniawan, Henry; Nusantara, Toto; Subanji; Susiswo; Setiawan, Iwan; Sutawidjaja, Akbar; As'ari, Abdur Rahman; Muksar, Makbul

    2016-01-01

    This research is an exploratory study with a qualitative approach, which is based on interviews with a task-based the purpose of this study is to describe the understanding of elementary school students in interpreting sub concept fractions in changing of the object is given to fractions with limit intervention. While intervention on problems…

  14. Wave function methods for fractional electrons.

    PubMed

    Steinmann, Stephan N; Yang, Weitao

    2013-08-21

    Determining accurate chemical potentials is of considerable interest in various chemical and physical contexts: from small molecular charge-transfer complexes to bandgap in bulk materials such as semi-conductors. Chemical potentials are typically evaluated either by density functional theory, or, alternatively, by computationally more intensive Greens function based GW computations. To calculate chemical potentials, the ground state energy needs to be defined for fractional charges. We thus explore an extension of wave function theories to fractional charges, and investigate the ionization potential and electron affinity as the derivatives of the energy with respect to the electron number. The ultimate aim is to access the chemical potential of correlated wave function methods without the need of explicitly changing the numbers of electrons, making the approach readily applicable to bulk materials. We find that even though second order perturbation theory reduces the fractional charge error considerably compared to Hartree-Fock and standard density functionals, higher order perturbation theory is more accurate and coupled-cluster approaches are even more robust, provided the electrons are bound at the Hartree-Fock level. The success of post-HF approaches to improve over HF relies on two equally important aspects: the integer values are more accurate and the Coulomb correlation between the fractionally occupied orbital and all others improves the straight line behavior significantly as identified by a correction to Hartree-Fock. Our description of fractional electrons is also applicable to fractional spins, illustrating the ability of coupled-cluster singles and doubles to deal with two degenerate fractionally occupied orbitals, but its inadequacy for three and more fractional spins, which occur, for instance, for spherical atoms and when dissociating double bonds. Our approach explores the realm of typical wave function methods that are applied mostly in molecular

  15. Wave function methods for fractional electrons

    NASA Astrophysics Data System (ADS)

    Steinmann, Stephan N.; Yang, Weitao

    2013-08-01

    Determining accurate chemical potentials is of considerable interest in various chemical and physical contexts: from small molecular charge-transfer complexes to bandgap in bulk materials such as semi-conductors. Chemical potentials are typically evaluated either by density functional theory, or, alternatively, by computationally more intensive Greens function based GW computations. To calculate chemical potentials, the ground state energy needs to be defined for fractional charges. We thus explore an extension of wave function theories to fractional charges, and investigate the ionization potential and electron affinity as the derivatives of the energy with respect to the electron number. The ultimate aim is to access the chemical potential of correlated wave function methods without the need of explicitly changing the numbers of electrons, making the approach readily applicable to bulk materials. We find that even though second order perturbation theory reduces the fractional charge error considerably compared to Hartree-Fock and standard density functionals, higher order perturbation theory is more accurate and coupled-cluster approaches are even more robust, provided the electrons are bound at the Hartree-Fock level. The success of post-HF approaches to improve over HF relies on two equally important aspects: the integer values are more accurate and the Coulomb correlation between the fractionally occupied orbital and all others improves the straight line behavior significantly as identified by a correction to Hartree-Fock. Our description of fractional electrons is also applicable to fractional spins, illustrating the ability of coupled-cluster singles and doubles to deal with two degenerate fractionally occupied orbitals, but its inadequacy for three and more fractional spins, which occur, for instance, for spherical atoms and when dissociating double bonds. Our approach explores the realm of typical wave function methods that are applied mostly in molecular

  16. Power plant intake entrainment analysis

    SciTech Connect

    Edinger, J.E.; Kolluru, V.S.

    2000-04-01

    Power plant condenser cooling water intake entrainment of fish eggs and larvae is becoming an issue in evaluating environmental impacts around the plants. Methods are required to evaluate intake entrainment on different types of water bodies. Presented in this paper is a derivation of the basic relationships for evaluating entrainment from the standing crop of fish eggs and larvae for different regions of a water body, and evaluating the rate of entrainment from the standing crop. These relationships are coupled with a 3D hydrodynamic and transport model that provides the currents and flows required to complete the entrainment evaluation. Case examples are presented for a simple river system, and for the more complex Delaware River Estuary with multiple intakes. Example evaluations are made for individual intakes, and for the cumulative impacts of multiple intakes.

  17. Approximate solutions to fractional subdiffusion equations

    NASA Astrophysics Data System (ADS)

    Hristov, J.

    2011-03-01

    The work presents integral solutions of the fractional subdiffusion equation by an integral method, as an alternative approach to the solutions employing hypergeometric functions. The integral solution suggests a preliminary defined profile with unknown coefficients and the concept of penetration (boundary layer). The prescribed profile satisfies the boundary conditions imposed by the boundary layer that allows its coefficients to be expressed through its depth as unique parameter. The integral approach to the fractional subdiffusion equation suggests a replacement of the real distribution function by the approximate profile. The solution was performed with Riemann-Liouville time-fractional derivative since the integral approach avoids the definition of the initial value of the time-derivative required by the Laplace transformed equations and leading to a transition to Caputo derivatives. The method is demonstrated by solutions to two simple fractional subdiffusion equations (Dirichlet problems): 1) Time-Fractional Diffusion Equation, and 2) Time-Fractional Drift Equation, both of them having fundamental solutions expressed through the M-Wright function. The solutions demonstrate some basic issues of the suggested integral approach, among them: a) Choice of the profile, b) Integration problem emerging when the distribution (profile) is replaced by a prescribed one with unknown coefficients; c) Optimization of the profile in view to minimize the average error of approximations; d) Numerical results allowing comparisons to the known solutions expressed to the M-Wright function and error estimations.

  18. Dietary intake of nutrients with adequate intake values in the dietary reference intakes for Japanese.

    PubMed

    Tsuboyama-Kasaoka, Nobuyo; Takizawa, Asuka; Tsubota-Utsugi, Megumi; Nakade, Makiko; Imai, Eri; Kondo, Akiko; Yoshida, Kazue; Okuda, Nagako; Nishi, Nobuo; Takimoto, Hidemi

    2013-01-01

    The Adequate Intake (AI) values in the Dietary Reference Intakes for Japanese (DRIs-J) 2010 were mainly determined based on the median intakes from 2 y of pooled data (2005-2006) from the National Health and Nutrition Survey-Japan (NHNS-J). However, it remains unclear whether 2 y of pooled data from the NHNS-J are appropriate for evaluating the intake of the population. To clarify the differences in nutrient intakes determined from 2 and 7 y of pooled data, we analyzed selected nutrient intake levels by sex and age groups using NHNS-J data. Intake data were obtained from 64,624 individuals (age: ≥1 y; 47.4% men) who completed a semi-weighed 1-d household dietary record that was part of the NHNS-J conducted annually in Japan from 2003 to 2009. There were no large differences between the median intakes calculated from 2 or 7 y of pooled data for n-6 or n-3 polyunsaturated fatty acids (PUFAs), vitamin D, pantothenic acid, potassium, or phosphorus. When the AI values and median intakes were compared, there was no large difference in the values for n-6 or n-3 PUFAs, pantothenic acid, or phosphorus. Conversely, the AI values for vitamin D and potassium differed from the median intakes of these nutrients for specific sex and age groups, because values were not based on NHNS-J data. Our results indicate that 2 y of pooled data from the NHNS-J adequately reflect the population's intake, and that the current system for determination of AI values will be applicable for future revisions.

  19. Micronutrients: dietary intake v. supplement use.

    PubMed

    Woodside, Jayne V; McCall, Damian; McGartland, Claire; Young, Ian S

    2005-11-01

    Whilst clinical deficiency of micronutrients is uncommon in the developed world, a suboptimal intake of certain micronutrients has been linked with an increased risk of chronic diseases such as CVD and cancer. Attention has therefore focused on increasing micronutrient status in order to theoretically reduce chronic disease risk. Increasing micronutrient status can involve a number of approaches: increasing dietary intake of micronutrient-rich foods; food fortification; use of supplements. Observational cohort studies have demonstrated an association between high intakes of micronutrients such as vitamin E, vitamin C, folic acid and beta-carotene, and lower risk of CHD, stroke and cancer at various sites. However, randomised intervention trials of micronutrient supplements have, to date, largely failed to show an improvement in clinical end points. The discordance between data from cohort studies and the results so far available from clinical trials remains to be explained. One reason may be that the complex mixture of micronutrients found, for example, in a diet high in fruit and vegetables may be more effective than large doses of a small number of micronutrients, and therefore that intervention studies that use single micronutrient supplements are unlikely to produce a lowering of disease risk. Studies concentrating on whole foods (e.g. fruit and vegetables) or diet pattern (e.g. Mediterranean diet pattern) may be more effective in demonstrating an effect on clinical end points. The present review will consider the clinical trial evidence for a beneficial effect of micronutrient supplements on health, and review the alternative approaches to the study of dietary intake of micronutrients.

  20. Dietary sodium intake among Canadian adults with and without hypertension.

    PubMed

    Shi, Y; de Groh, M; Morrison, H; Robinson, C; Vardy, L

    2011-03-01

    Almost 30% of hypertension among Canadians may be attributed to excess dietary sodium. We examined the average sodium intake of Canadians aged 30 years and over, with and without hypertension, by age, sex and diabetes status using 24-hour recall data from the 2004 Canadian Community Health Survey, Cycle 2.2, Nutrition. We compared absolute (crude) average sodium intake levels of those with and without hypertension to the 2009 Canadian Hypertension Education Program (CHEP) guidelines and adjusted average sodium intake between those with and without hypertension. Both those with and without diagnosed hypertension display average sodium intakes well above the 1500 mg/day recommended by the 2009 CHEP guidelines (2950 mg/day and 3175 mg/day, respectively). After confounding adjustment, those with hypertension have significantly higher average sodium intake (p = .0124). Stratified subgroup analyses found the average sodium intake among those with hypertension was higher for men between 30 and 49 years old (p = .0265), women between 50 and 69 years old (p = .0083) and those without diabetes (p = .0071) when compared to their counterparts without hypertension. Better approaches are needed to reduce sodium intake in hypertension patients, as well as the general population.

  1. Changes in dietary intake and nutritional status associated with a significant reduction in sodium intake in patients with heart failure. A sub-analysis of the SODIUM-HF pilot study.

    PubMed

    Colin-Ramirez, Eloisa; McAlister, Finlay A; Zheng, Yinggan; Sharma, Sangita; Ezekowitz, Justin A

    2016-02-01

    Concerns have been raised about the impact of dietary sodium restriction on the overall dietary intake and nutritional status in patients with heart failure (HF). The objective of this study was to evaluate the association between a significant reduction in sodium intake and dietary changes and nutritional status in patients with chronic HF. This is a secondary analysis of 38 patients enrolled in a pilot study of dietary sodium reduction. Patients were classified into two groups according to a level of sodium reduction achieved (≥25% [n = 21 patients] and <25% [n = 14 patients]) at 6 months. Between group changes in energy, nutrient intake, weight loss, and hand grip strength from baseline to 6 months were compared. Patients had a median age of 65 years, 51% were male, median body mass index was 30.7 kg/m(2) and median ejection fraction was 39%. Over 6 months, the group with ≥25% sodium reduction exhibited a greater increase in folate intake [median change 50 mcg/day (25th-75th percentiles: -101, 167) vs. -31 mcg/day (25th-75th percentiles: -221, 51), p = 0.04 between groups] and a larger reduction in calcium intake [median change -262 (25th-75th percentiles: -585, -9) vs. 91 (25th-75th percentiles: -114, 210), p = 0.01 between groups], and were more likely to meet the parameters of the DASH diet compared to the <25% sodium reduction group. No significant differences between groups were seen for caloric intake and other relevant nutrients and no significant weight loss was found in either group. Dietary sodium reduction may be achieved without compromising overall dietary intake and nutritional status in patients with HF when an individualized and comprehensive dietary approached is used. Clinicaltrials.gov identifier: NCT01480401. Copyright © 2015 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

  2. Neutron Imaging Calibration to Measure Void Fraction

    SciTech Connect

    Geoghegan, Patrick J; Bilheux, Hassina Z; Sharma, Vishaldeep; Fricke, Brian A

    2015-01-01

    Void fraction is an intuitive parameter that describes the fraction of vapor in a two-phase flow. It appears as a key variable in most heat transfer and pressure drop correlations used to design evaporating and condensing heat exchangers, as well as determining charge inventory in refrigeration systems. Void fraction measurement is not straightforward, however, and assumptions on the invasiveness of the measuring technique must be made. Neutron radiography or neutron imaging has the potential to be a truly non-invasive void fraction measuring technique but has until recently only offered qualitative descriptions of two-phase flow, in terms of flow maldistributions, for example. This paper describes the calibration approach necessary to employ neutron imaging to measure steady-state void fraction. Experiments were conducted at the High Flux Isotope Reactor (HFIR) Cold Guide 1D neutron imaging facility at Oak Ridge National Laboratory (ORNL), Oak Ridge, TN, USA.

  3. Harmonization of nutrient intake values.

    PubMed

    King, Janet C; Garza, Cutberto

    2007-03-01

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

  4. Exact solution to fractional logistic equation

    NASA Astrophysics Data System (ADS)

    West, Bruce J.

    2015-07-01

    The logistic equation is one of the most familiar nonlinear differential equations in the biological and social sciences. Herein we provide an exact solution to an extension of this equation to incorporate memory through the use of fractional derivatives in time. The solution to the fractional logistic equation (FLE) is obtained using the Carleman embedding technique that allows the nonlinear equation to be replaced by an infinite-order set of linear equations, which we then solve exactly. The formal series expansion for the initial value solution of the FLE is shown to be expressed in terms of a series of weighted Mittag-Leffler functions that reduces to the well known analytic solution in the limit where the fractional index for the derivative approaches unity. The numerical integration to the FLE provides an excellent fit to the analytic solution. We propose this approach as a general technique for solving a class of nonlinear fractional differential equations.

  5. Fractional kinetics in multi-compartmental systems.

    PubMed

    Dokoumetzidis, Aristides; Magin, Richard; Macheras, Panos

    2010-10-01

    Fractional calculus, the branch of calculus dealing with derivatives of non-integer order (e.g., the half-derivative) allows the formulation of fractional differential equations (FDEs), which have recently been applied to pharmacokinetics (PK) for one-compartment models. In this work we extend that theory to multi-compartmental models. Unlike systems defined by a single ordinary differential equation (ODE), considering fractional multi-compartmental models is not as simple as changing the order of the ordinary derivatives of the left-hand side of the ODEs to fractional orders. The latter may produce inconsistent systems which violate mass balance. We present a rationale for fractionalization of ODEs, which produces consistent systems and allows processes of different fractional orders in the same system. We also apply a method of solving such systems based on a numerical inverse Laplace transform algorithm, which we demonstrate that is consistent with analytical solutions when these are available. As examples of our approach, we consider two cases of a basic two-compartment PK model with a single IV dose and multiple oral dosing, where the transfer from the peripheral to the central compartment is of fractional order α < 1, accounting for anomalous kinetics and deep tissue trapping, while all other processes are of the usual order 1. Simulations with the studied systems are performed using the numerical inverse Laplace transform method. It is shown that the presence of a transfer rate of fractional order produces a non-exponential terminal phase, while multiple dose and constant infusion systems never reach steady state and drug accumulation carries on indefinitely. The IV fractional system is also fitted to PK data and parameter values are estimated. In conclusion, our approach allows the formulation of systems of FDEs, mixing different fractional orders, in a consistent manner and also provides a method for the numerical solution of these systems.

  6. Profiling food volatiles by comprehensive two-dimensional ga schromatography coupled with mass spectrometry: advanced fingerprinting approaches for comparative analysis of the volatile fraction of roasted hazelnuts (Corylus avellana L.) from different origins.

    PubMed

    Cordero, Chiara; Liberto, Erica; Bicchi, Carlo; Rubiolo, Patrizia; Schieberle, Peter; Reichenbach, Stephen E; Tao, Qingping

    2010-09-10

    This study examined how advanced fingerprinting methods (i.e., non-targeted methods) provide reliable and specific information about groups of samples based on their component distribution on the GC x GC chromatographic plane. The volatile fractions of roasted hazelnuts (Corylus avellana L.) from nine different geographical origins, comparably roasted for desirable flavor and texture, were sampled by headspace-solid phase micro extraction (HS-SPME) and then analyzed by GC x GC-qMS. The resulting patterns were processed by: (a) "chromatographic fingerprinting", i.e., a pattern recognition procedure based on retention-time criteria, where peaks correspondences were established through a comprehensive peak pattern covering the chromatographic plane; and (b) "comprehensive template matching" with reliable peak matching, where peak correspondences were constrained by retention time and MS fragmentation pattern similarity criteria. Fingerprinting results showed how the discrimination potential of GC x GC can be increased by including in sample comparisons and correlations all the detected components and, in addition, provide reliable results in a comparative analysis by locating compounds with a significant role. Results were completed by a chemical speciation of volatiles and sample profiling was extended to known markers whose distribution can be correlated to sensory properties, geographical origin, or the effect of thermal treatment on different classes of compounds. The comprehensive approach for data interpretation here proposed may be useful to assess product specificity and quality, through measurable parameters strictly and consistently correlated to sensory properties and origin. Copyright 2010 Elsevier B.V. All rights reserved.

  7. Fractionation: past, present, future.

    PubMed

    Saedi, Nazanin; Jalian, H Ray; Petelin, Anthony; Zachary, Christopher

    2012-06-01

    The development of fractional photothermolysis is a milestone in the history of laser technology and cutaneous resurfacing. Based on the concept that skin is treated in a fractional manner, where narrow cylinders of tissue are thermally heated and normal adjacent skin is left unaffected, the fractional devices have shown effectiveness in treating a variety of conditions. Since its development, we are becoming more adept at using optimal parameters to induce near carbon dioxide laser benefits with a much more comfortable postoperative period and fewer complications. The future remains bright for fractionated laser devices and with new devices and wavelengths, the applications of this technology continue to grow. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Quantifying Drosophila food intake: comparative analysis of current methodology

    PubMed Central

    Deshpande, Sonali A.; Carvalho, Gil B.; Amador, Ariadna; Phillips, Angela M.; Hoxha, Sany; Lizotte, Keith J.; Ja, William W.

    2014-01-01

    Food intake is a fundamental parameter in animal studies. Despite the prevalent use of Drosophila in laboratory research, precise measurements of food intake remain challenging in this model organism. Here, we compare several common Drosophila feeding assays: the Capillary Feeder (CAFE), food-labeling with a radioactive tracer or a colorimetric dye, and observations of proboscis extension (PE). We show that the CAFE and radioisotope-labeling provide the most consistent results, have the highest sensitivity, and can resolve differences in feeding that dye-labeling and PE fail to distinguish. We conclude that performing the radiolabeling and CAFE assays in parallel is currently the best approach for quantifying Drosophila food intake. Understanding the strengths and limitations of food intake methodology will greatly advance Drosophila studies of nutrition, behavior, and disease. PMID:24681694

  9. Catalytic reforming of naphtha fractions

    SciTech Connect

    Bishop, K.C.; Vorhis, F.H.

    1980-09-16

    Production of motor gasoline and a btx-enriched reformate by fractionating a naphtha feedstock into a mid-boiling btxprecursor fraction, a relatively high-boiling fraction and a relatively low-boiling fraction; catalytically reforming the btxprecursor fraction in a first reforming zone; combining the relatively high-boiling and low-boiling fractions and catalytically reforming the combined fractions in a second reforming zone.

  10. The association between motivation and fruit and vegetable intake: The moderating role of social support.

    PubMed

    McSpadden, Kate E; Patrick, Heather; Oh, April Y; Yaroch, Amy L; Dwyer, Laura A; Nebeling, Linda C

    2016-01-01

    Despite knowing that fruit and vegetable (FV) intake promotes health and well-being, few U.S. adults meet current guidelines. Thus, understanding people's motivation for FV intake is important for predicting dietary behavior. Applying self-determination theory, the goal of this study was to examine the role of social support as a potential moderator of the link between autonomous and controlled motivations and FV intake. Cross-sectional data from 2959 adults in the United States were analyzed. Autonomous motivation and perceived social support were positively associated with FV intake, while controlled motivation was negatively associated with FV intake. Additionally, there was evidence that the negative association between controlled motivation and FV intake was attenuated by higher levels of perceived social support. Findings suggest the need for a more comprehensive approach to understanding the role of motivation in health behaviors like FV intake and the potential roles played by friends and family in these motivational processes.

  11. Symmetric continued fractions

    SciTech Connect

    Panprasitwech, Oranit; Laohakosol, Vichian; Chaichana, Tuangrat

    2010-11-11

    Explicit formulae for continued fractions with symmetric patterns in their partial quotients are constructed in the field of formal power series. Similar to the work of Cohn in 1996, which generalized the so-called folding lemma to {kappa}-fold symmetry, the notion of {kappa}-duplicating symmetric continued fractions is investigated using a modification of the 1995 technique due to Clemens, Merrill and Roeder.

  12. Thermodynamics in Fractional Calculus

    NASA Astrophysics Data System (ADS)

    Meilanov, R. P.; Magomedov, R. A.

    2014-11-01

    A generalization of thermodynamics in the formalism of fractional-order derivatives is given. Results of the traditional thermodynamics of Carnot, Clausius, and Helmholtz are obtained in the particular case where the exponent of a fractional-order derivative is equal to unity. A one-parametric "fractal" equation of state is obtained with account of the second virial coefficient. The application of the resulting equation of state in the case of the gas argon is considered.

  13. Intracellular Cadmium Isotope Fractionation

    NASA Astrophysics Data System (ADS)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  14. Dietary Salt Intake and Hypertension

    PubMed Central

    2014-01-01

    Over the past century, salt has been the subject of intense scientific research related to blood pressure elevation and cardiovascular mortalities. Moderate reduction of dietary salt intake is generally an effective measure to reduce blood pressure. However, recently some in the academic society and lay media dispute the benefits of salt restriction, pointing to inconsistent outcomes noted in some observational studies. A reduction in dietary salt from the current intake of 9-12 g/day to the recommended level of less than 5-6 g/day will have major beneficial effects on cardiovascular health along with major healthcare cost savings around the world. The World Health Organization (WHO) strongly recommended to reduce dietary salt intake as one of the top priority actions to tackle the global non-communicable disease crisis and has urged member nations to take action to reduce population wide dietary salt intake to decrease the number of deaths from hypertension, cardiovascular disease and stroke. However, some scientists still advocate the possibility of increased risk of CVD morbidity and mortality at extremes of low salt intake. Future research may inform the optimal sodium reduction strategies and intake targets for general populations. Until then, we have to continue to build consensus around the greatest benefits of salt reduction for CVD prevention, and dietary salt intake reduction strategies must remain at the top of the public health agenda. PMID:25061468

  15. Fractional diffusion: recovering the distributed fractional derivative from overposed data

    NASA Astrophysics Data System (ADS)

    Rundell, W.; Zhang, Z.

    2017-03-01

    There has been considerable recent study in ‘subdiffusion’ models that replace the standard parabolic equation model by a one with a fractional derivative in the time variable. There are many ways to look at this newer approach and one such is to realize that the order of the fractional derivative is related to the time scales of the underlying diffusion process. This raises the question of what order α of derivative should be taken and if a single value actually suffices. This has led to models that combine a finite number of these derivatives each with a different fractional exponent {αk} and different weighting value c k to better model a greater possible range of time scales. Ultimately, one wants to look at a situation that combines derivatives in a continuous way—the so-called distributional model with parameter μ ≤ft(α \\right) . However all of this begs the question of how one determines this ‘order’ of differentiation. Recovering a single fractional value has been an active part of the process from the beginning of fractional diffusion modeling and if this is the only unknown then the markers left by the fractional order derivative are relatively straightforward to determine. In the case of a finite combination of derivatives this becomes much more complex due to the more limited analytic tools available for such equations, but recent progress in this direction has been made, (Li et al 2015 Appl. Math. Comput. 257 381–97, Li and Yamamoto 2015 Appl. Anal. 94 570–9). This paper considers the full distributional model where the order is viewed as a function μ ≤ft(α \\right) on the interval (0, 1]. We show existence, uniqueness and regularity for an initial-boundary value problem including an important representation theorem in the case of a single spatial variable. This is then used in the inverse problem of recovering the distributional coefficient μ ≤ft(α \\right) from a time trace of the solution and a uniqueness result is

  16. Chromatographic methods of fractionation.

    PubMed

    Friesen, A D

    1987-01-01

    Chromatography's functional versatility, separation efficiency, gentle non-denaturing separating process and ease of automation and scale-up make it attractive for industrial scale protein purification. The Winnipeg Rh Institute's new Plasma Fractionation facility is an example of the use of chromatography for the large scale purification of plasma protein fractions. The fractionation facility has a capacity to process 800 litres of plasma per batch into blood clotting factor VIII and IX, albumin and intravenous immune serum globulin (i.v. ISG). Albumin and i.v. ISG are purified using ion exchange columns of DEAE-Sepharose (230 litre size), DEAE-Biogel (150 litre size) and CM-Sepharose (150 litre size). The chromatographic process is automated using a Modicon 584 Programmable Logic Controller to regulate valves, pumps and sensors which control plasma flow during fractionation. The stainless steel tanks and piping are automatically cleaned-in-place. The high degree of automation and cleaning provides efficient operation and sanitary processing. Chromatographic methods (DEAE-Sepharose and metal chelation) are also being used at the pilot scale to purify the human blood products superoxide dismutase and hemoglobin from outdated red blood cells. Characterization of the protein fractions produced by chromatography has shown them to be of equal or higher quality than fractions produced by other techniques.

  17. Fractional laser skin resurfacing.

    PubMed

    Alexiades-Armenakas, Macrene R; Dover, Jeffrey S; Arndt, Kenneth A

    2012-11-01

    Laser skin resurfacing (LSR) has evolved over the past 2 decades from traditional ablative to fractional nonablative and fractional ablative resurfacing. Traditional ablative LSR was highly effective in reducing rhytides, photoaging, and acne scarring but was associated with significant side effects and complications. In contrast, nonablative LSR was very safe but failed to deliver consistent clinical improvement. Fractional LSR has achieved the middle ground; it combined the efficacy of traditional LSR with the safety of nonablative modalities. The first fractional laser was a nonablative erbium-doped yttrium aluminum garnet (Er:YAG) laser that produced microscopic columns of thermal injury in the epidermis and upper dermis. Heralding an entirely new concept of laser energy delivery, it delivered the laser beam in microarrays. It resulted in microscopic columns of treated tissue and intervening areas of untreated skin, which yielded rapid reepithelialization. Fractional delivery was quickly applied to ablative wavelengths such as carbon dioxide, Er:YAG, and yttrium scandium gallium garnet (2,790 nm), providing more significant clinical outcomes. Adjustable laser parameters, including power, pitch, dwell time, and spot density, allowed for precise determination of percent surface area, affected penetration depth, and clinical recovery time and efficacy. Fractional LSR has been a significant advance to the laser field, striking the balance between safety and efficacy.

  18. The maximum oxygen intake*

    PubMed Central

    Shephard, Roy J.; Allen, C.; Benade, A. J. S.; Davies, C. T. M.; di Prampero, P. E.; Hedman, R.; Merriman, J. E.; Myhre, K.; Simmons, R.

    1968-01-01

    Lack of cardiorespiratory fitness may well contribute to the increasing prevalence of degenerative cardiovascular disease throughout the world. As a first step towards co-ordinated and internationally comparable investigation of this problem, methods of measuring the reference standard of cardiorespiratory fitness—the maximum oxygen intake, (V̇o2)max—were compared by an international working party that met in Toronto in the summer of 1967. Repeated testing of 24 subjects showed that the (V̇o2)max was greatest on the treadmill, 3.4% smaller in a stepping test, and 6.6% smaller during use of a bicycle ergometer. There were also parallel differences in cardiac stroke volume. Uphill treadmill running was recommended for the laboratory measurement of (V̇o2)max, and stepping or bicycle exercise for field studies. A discontinuous series of maximum tests caused some improvement in the fitness of subjects, and a “continuous” test (with small increases in load at 2-min intervals) was preferred. PMID:5303329

  19. Fiber intake and childhood appendicitis.

    PubMed Central

    Brender, J D; Weiss, N S; Koepsell, T D; Marcuse, E K

    1985-01-01

    Parents of 135 children with appendicitis and of 212 comparison children were interviewed about their children's diet. Children in the upper two quartiles of fiber intake were estimated to have a 30 per cent lower risk of appendicitis than children in the lowest quartile. Estimated risk of appendicitis decreased as monthly intake of whole-grain foods increased. Children 7 to 18 years of age who had an intake of whole-grain foods in the upper fiftieth percentile were estimated to have a 50 per cent lower risk of appendicitis. This reduction in risk was not observed in the group of children less than 7 years of age. PMID:2983577

  20. Weighted fractional permutation entropy and fractional sample entropy for nonlinear Potts financial dynamics

    NASA Astrophysics Data System (ADS)

    Xu, Kaixuan; Wang, Jun

    2017-02-01

    In this paper, recently introduced permutation entropy and sample entropy are further developed to the fractional cases, weighted fractional permutation entropy (WFPE) and fractional sample entropy (FSE). The fractional order generalization of information entropy is utilized in the above two complexity approaches, to detect the statistical characteristics of fractional order information in complex systems. The effectiveness analysis of proposed methods on the synthetic data and the real-world data reveals that tuning the fractional order allows a high sensitivity and more accurate characterization to the signal evolution, which is useful in describing the dynamics of complex systems. Moreover, the numerical research on nonlinear complexity behaviors is compared between the returns series of Potts financial model and the actual stock markets. And the empirical results confirm the feasibility of the proposed model.

  1. Girls' dairy intake, energy intake, and weight status.

    PubMed

    Fiorito, Laura M; Ventura, Alison K; Mitchell, Diane C; Smiciklas-Wright, Helen; Birch, Leann L

    2006-11-01

    We explored the relationships among girls' weight status, dairy servings, and total energy intake. The hypothesis that consuming dairy could reduce risk for overweight was evaluated by comparing energy intake and weight status of girls who met or consumed less than the recommended three servings of dairy per day. Participants included 172 11-year-old non-Hispanic white girls, assessed cross-sectionally. Intakes of dairy, calcium, and energy were measured using three 24-hour recalls. Body mass index and body fat measures from dual-energy x-ray absorptiometry were obtained. Because preliminary analyses suggested systematic underreporting of energy intake, the relationships among dairy servings and measures of weight status were examined for the total sample and for subsamples of under-, plausible, and overreporters. Data for the total sample provided support for the hypothesized relationship among weight status, dairy servings, and energy intake. Thirty-nine percent of girls reported consuming the recommended >/=3 servings of dairy per day; these girls also reported higher energy intake but had lower body mass index z scores and body fat than the girls who consumed fewer than three dairy servings each day. Among plausible reporters, no relationship between dairy intake and weight status was noted. This discrepancy may be attributable to a high percentage (45%) of overweight underreporters in the total sample. Our findings reveal that reporting bias, resulting from the presence of a substantial proportion of underreporters of higher weight status, can contribute to obtaining spurious associations between dairy intake and weight status. These findings underscore the need for randomly controlled trials to assess the role of dairy in weight management.

  2. Girls’ Dairy Intake, Energy Intake, and Weight Status

    PubMed Central

    FIORITO, LAURA M.; VENTURA, ALISON K.; MITCHELL, DIANE C.; SMICIKLAS-WRIGHT, HELEN; BIRCH, LEANN L.

    2008-01-01

    We explored the relationships among girls’ weight status, dairy servings, and total energy intake. The hypothesis that consuming dairy could reduce risk for overweight was evaluated by comparing energy intake and weight status of girls who met or consumed less than the recommended three servings of dairy per day. Participants included 172 11-year-old non-Hispanic white girls, assessed cross-sectionally. Intakes of dairy, calcium, and energy were measured using three 24-hour recalls. Body mass index and body fat measures from dual-energy x-ray absorptiometry were obtained. Because preliminary analyses suggested systematic underreporting of energy intake, the relationships among dairy servings and measures of weight status were examined for the total sample and for subsamples of under-, plausible, and overreporters. Data for the total sample provided support for the hypothesized relationship among weight status, dairy servings, and energy intake. Thirty-nine percent of girls reported consuming the recommended ≥3 servings of dairy per day; these girls also reported higher energy intake but had lower body mass index z scores and body fat than the girls who consumed fewer than three dairy servings each day. Among plausible reporters, no relationship between dairy intake and weight status was noted. This discrepancy may be attributable to a high percentage (45%) of overweight underreporters in the total sample. Our findings reveal that reporting bias, resulting from the presence of a substantial proportion of underreporters of higher weight status, can contribute to obtaining spurious associations between dairy intake and weight status. These findings underscore the need for randomly controlled trials to assess the role of dairy in weight management. PMID:17081836

  3. 11. Photocopied August 1978. INTAKE LOOKING NORTH AT UPPER INTAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photocopied August 1978. INTAKE LOOKING NORTH AT UPPER INTAKE COFFER DAM, OCTOBER 10, 1900. ONE OF THE HUBBELL COMPANY DREDGES IS AT WORK IN THE CENTER OF THE ILLUSTRATION, THE TIMBER FLOATING AROUND WAS PROBABLY FOR USE IN THE CONSTRUCTION OF SIDE WALL RETAINING CRIBS. ONE OF THESE IS BEING CONSTRUCTED JUST TO THE LEFT AND TOWARDS THE VIEWER FROM THE DREDGES. (87) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

  4. Plant and soil intake by organic broilers reared in tree- or grass-covered plots as determined by means of n-alkanes and of acid-insoluble ash.

    PubMed

    Jurjanz, S; Germain, K; Juin, H; Jondreville, C

    2015-05-01

    Free-range birds such as organic broilers may ingest soil and plants during exploration. The estimation of such intakes is of great interest to quantify possible nutritional supplies and also to evaluate the risk of exposure to parasites or to environmental contaminants. Marker-based techniques are now available and would allow to quantify plant and, especially, soil intake in free-range birds, and this quantification was the aim of this study. Methodologically, the proportion of plants in diet intake was determined first using a method based on n-alkanes. Subsequently, the fraction of soil in the total intake was estimated with a second marker, acid-insoluble ash. This approach was carried out to estimate ingested amounts of plants and soil for five successive flocks of organic broilers, exploring grass-covered yards or those under trees, at two time points for each yard: 51 and 64 days of age. Each factor combination (yard type×period=flock number×age) was repeated on two different yards of 750 broilers each. The birds' plant intake varied widely, especially on grass-covered yards. The proportion of plant intake was significantly higher on grass-covered plots than under trees and was also affected, but to a lesser extent, by age or flock number. The ingestion of plants would generally not exceed 11 g of DM daily, except two extreme outliers of nearly 30 g. The daily plant intake under trees tended to be lower and never exceeded 7 g of DM. The amount of ingested plants increased significantly for spring flocks. It increased slightly but significantly with age. The proportion of ingested soil was significantly higher under trees than on grass-covered yards. Dry soil intake was generally low with not more than 3 g per day. Only in adverse conditions - that is, older birds exploring yards under trees in winter - soil intake reached the extreme value of nearly 5 g. Broilers on yards under trees ingested significantly more soil than on grass-covered yards with least

  5. Modeling some real phenomena by fractional differential equations

    NASA Astrophysics Data System (ADS)

    Almeida, Ricardo; Bastos, Nuno R. O.; Monteiro, M. Teresa T.

    2016-11-01

    This paper deals with fractional differential equations, with dependence on a Caputo fractional derivative of real order. The goal is to show, based on concrete examples and experimental data from several experiments, that fractional differential equations may model more efficiently certain problems than ordinary differential equations. A numerical optimization approach based on least squares approximation is used to determine the order of the fractional operator that better describes real data, as well as other related parameters.

  6. Numerical simulation of pump-intake vortices

    NASA Astrophysics Data System (ADS)

    Rudolf, Pavel; Klas, Roman

    2015-05-01

    Pump pre-swirl or uneven flow distribution in front of the pump can induce pump-intake vortices. These phenomena result in blockage of the impeller suction space, deterioration of efficiency, drop of head curve and earlier onset of cavitation. Real problematic case, where head curve drop was documented, is simulated using commercial CFD software. Computational simulation was carried out for three flow rates, which correspond to three operating regimes of the vertical pump. The domain consists of the pump sump, pump itself excluding the impeller and the delivery pipe. One-phase approach is applied, because the vortex cores were not filled with air during observation of the real pump operation. Numerical simulation identified two surface vortices and one bottom vortex. Their position and strength depend on the pump flow rate. Paper presents detail analysis of the flow field on the pump intake, discusses influence of the vortices on pump operation and suggests possible actions that should be taken to suppress the intake vortices.

  7. Modern plasma fractionation.

    PubMed

    Burnouf, Thierry

    2007-04-01

    Protein products fractionated from human plasma are an essential class of therapeutics used, often as the only available option, in the prevention, management, and treatment of life-threatening conditions resulting from trauma, congenital deficiencies, immunologic disorders, or infections. Modern plasma product production technology remains largely based on the ethanol fractionation process, but much has evolved in the last few years to improve product purity, to enhance the recovery of immunoglobulin G, and to isolate new plasma proteins, such as alpha1-protease inhibitor, von Willebrand factor, and protein C. Because of the human origin of the starting material and the pooling of 10,000 to 50,000 donations required for industrial processing, the major risk associated to plasma products is the transmission of blood-borne infectious agents. A complete set of measures--and, most particularly, the use of dedicated viral inactivation and removal treatments--has been implemented throughout the production chain of fractionated plasma products over the last 20 years to ensure optimal safety, in particular, and not exclusively, against HIV, hepatitis B virus, and hepatitis C virus. In this review, we summarize the practices of the modern plasma fractionation industry from the collection of the raw plasma material to the industrial manufacture of fractionated products. We describe the quality requirements of plasma for fractionation and the various treatments applied for the inactivation and removal of blood-borne infectious agents and provide examples of methods used for the purification of the various classes of plasma protein therapies. We also highlight aspects of the good manufacturing practices and the regulatory environment that govern the whole chain of production. In a regulated and professional environment, fractionated plasma products manufactured by modern processes are certainly among the lowest-risk therapeutic biological products in use today.

  8. Control of Initialized Fractional-Order Systems

    NASA Technical Reports Server (NTRS)

    Hartley, Tom T.; Lorenzo, Carl F.

    2004-01-01

    Fractional-Order systems, or systems containing fractional derivatives and integrals, have been studied by many in the engineering area. Additionally, very readable discussions, devoted specifically to the subject, are presented by Oldham and Spanier, Miller and Ross, and Pudlubny (1999a). It should be noted that there are a growing number of physical systems whose behavior can be compactly described using fractional system theory. Of specific interest to electrical engineers are long lines, electrochemical processes, dielectric polarization, colored noise, viscoelastic materials, and chaos. With the growing number of applications, it is important to establish a theory of control for these fractional-order systems, and for the potential use of fractional-order systems as feedback compensators. This topic is addressed in this paper. The first section discusses the control of fractional-order systems using a vector space representation, where initialization is included in the discussion. It should be noted that Bagley and Calico and Padovan and Sawicki both present a fractional state-space representation, which do not include the important historic effects. Incorporation of these effects based on the initialized fractional calculus is presented . The control methods presented in this paper are based on the initialized fractional order system theory. The second section presents an input-output approach. Some of the problems encountered in these sections are: a) the need to introduce a new complex plane to study the dynamics of fractional-order systems, b) the need to properly define the Laplace transform of the fractional derivative, and c) the proper inclusion of the initialization response in the system and control formulation. Following this, the next section generalizes the proportional-plus-integral-control (PI-control) and PID-control (PI-plus- derivative) concepts using fractional integrals. This is then further generalized using general fractional- order

  9. Control of Initialized Fractional-Order Systems

    NASA Technical Reports Server (NTRS)

    Hartley, Tom T.; Lorenzo, Carl F.

    2004-01-01

    Fractional-Order systems, or systems containing fractional derivatives and integrals, have been studied by many in the engineering area. Additionally, very readable discussions, devoted specifically to the subject, are presented by Oldham and Spanier, Miller and Ross, and Pudlubny (1999a). It should be noted that there are a growing number of physical systems whose behavior can be compactly described using fractional system theory. Of specific interest to electrical engineers are long lines, electrochemical processes, dielectric polarization, colored noise, viscoelastic materials, and chaos. With the growing number of applications, it is important to establish a theory of control for these fractional-order systems, and for the potential use of fractional-order systems as feedback compensators. This topic is addressed in this paper. The first section discusses the control of fractional-order systems using a vector space representation, where initialization is included in the discussion. It should be noted that Bagley and Calico and Padovan and Sawicki both present a fractional state-space representation, which do not include the important historic effects. Incorporation of these effects based on the initialized fractional calculus is presented . The control methods presented in this paper are based on the initialized fractional order system theory. The second section presents an input-output approach. Some of the problems encountered in these sections are: a) the need to introduce a new complex plane to study the dynamics of fractional-order systems, b) the need to properly define the Laplace transform of the fractional derivative, and c) the proper inclusion of the initialization response in the system and control formulation. Following this, the next section generalizes the proportional-plus-integral-control (PI-control) and PID-control (PI-plus- derivative) concepts using fractional integrals. This is then further generalized using general fractional- order

  10. Carbohydrate Intake Considerations for Young Athletes

    PubMed Central

    Montfort-Steiger, Veronica; Williams, Craig A.

    2007-01-01

    Good nutritional practices are important for exercise performance and health during all ages. Athletes and especially growing children engaged in heavy training have higher energy and nutrient requirements compared to their non-active counterparts. Scientific understanding of sports nutrition for the young athlete is lacking behind the growing number of young athletes engaged in sports. Most of the sports nutrition recommendations given to athletic children and adolescents are based on adult findings due to the deficiency in age specific information in young athletes. Therefore, this review reflects on child specific sports nutrition, particularly on carbohydrate intake and metabolism that distinguishes the child athlete from the adult athlete. Children are characterised to be in an insulin resistance stage during certain periods of maturation, have different glycolytic/metabolic responses during exercise, have a tendency for higher fat oxidation during exercise and show different heat dissipation mechanisms compared to adults. These features point out that young athletes may need different nutritional advice on carbohydrate for exercise to those from adult athletes. Sport drinks for example may need to be adapted to children specific needs. However, more research in this area is warranted to clarify sports nutrition needs of the young athlete to provide better and healthy nutritional guidance to young athletes. Key pointsAthletic girls show lower carbohydrate intakes compared to boys.Substrate oxidation during exercise appears to be maturity related, fat being the preferred fuel for oxidation in younger athletic children.Children appear to have lower endogenous but greater exogenous carbohydrate oxidation rates during exercise.Carbohydrate intake during exercise appears to show no additional performance improvement in young athletes. Perhaps fat intake or a combination of both nutrients may be a better approach for nutrient supplementation during exercise

  11. Dietary Reference Intakes (DRIs) in Japan.

    PubMed

    Sasaki, Satoshi

    2008-01-01

    Following the comprehensive systematic review of domestic and overseas scientific evidence, the "Dietary Reference Intakes for Japanese, 2005 (DRI-J)" was published in April, 2005. The DRIs-J were prepared for health individuals and groups and designed to present a reference for intake values of energy and 34 nutrients to maintain and promote health and to prevent lifestyle-related diseases and illness due to excessive consumption of either energy or nutrients. The DRI-J also includes a special chapter for basic knowledge of DRIs. The energy recommendation is provided as an estimated energy requirement (EER), while five indices were used for nutrients: Estimated average requirement (EAR), recommended dietary allowance (RDA), adequate intake (AI), tolerable upper intake level (UL), and tentative dietary goal for preventing lifestyle-related [chronic non-communicable] diseases (DG). Whilst the first four indices are same as the ones used in other countries, DG is unique index in Japan, which was set as a reference value for preventing non-communicable diseases such as cardiovascular (including hypertension), major types of cancer and osteoporosis. This report (DRI-J) is the first dietary guidance in Japan, which applied evidence-based approach utilizing a systematic review process. Only a few articles from within Japan and other Asian countries could be used for its establishment. The project to establish the DRI-J revealed a severe lack of researchers and publications focused upon establishing DRIs for Japanese. Further review is therefore required in preparation for the next revision scheduled in 2010.

  12. Low level alcohol intake, cigarette smoking and risk of breast cancer in Asian-American women

    PubMed Central

    Brown, Linda Morris; Gridley, Gloria; Wu, Anna H.; Falk, Roni T.; Hauptmann, Michael; Kolonel, Laurence N.; West, Dee W.; Nomura, Abraham M. Y.; Pike, Malcolm C.; Hoover, Robert N.; Ziegler, Regina G.

    2009-01-01

    Studies have shown that breast cancer incidence rates among Asian migrants to the United States approach U.S. incidence rates over several generations, implicating potentially modifiable exposures such as moderate alcohol use that has been linked to excess breast cancer risk in other populations. The goal of this study was to investigate the effect of alcohol intake, primarily low levels, on breast cancer risk in Asian-American women and explore whether smoking and alcohol contributed to the in breast cancer incidence rates observed among Asian migrants to the United States. Study subjects in this population-based case-control study included 597 incident cases of breast cancer of Chinese, Japanese, and Filipino ethnicity living in San Francisco-Oakland, Los Angeles, and Oahu, Hawaii and 966 population controls frequency matched on age, ethnicity, and area of residence. The fraction of smokers and drinkers was significantly higher in women born in Western compared with Eastern countries. However, breast cancer risk was not significantly associated with smoking (odds ratio (OR) = 1.2, 95% confidence interval (95% CI) = 0.9–1.6) or alcohol drinking (OR = 0.9, 95% CI = 0.7–1.1) in this population of low consumers of alcohol (median intake among drinkers in grams per day was 0.48 for cases and 0.40 for controls). These data suggest that low alcohol intake is not related to increased breast cancer risk in Asian-American women and that neither alcohol nor cigarette use contributed to the elevated risks in Asian-American women associated with migration patterns and Westernization. PMID:19597702

  13. Power Plant Water Intake Assessment.

    ERIC Educational Resources Information Center

    Zeitoun, Ibrahim H.; And Others

    1980-01-01

    In order to adequately assess the impact of power plant cooling water intake on an aquatic ecosystem, total ecosystem effects must be considered, rather than merely numbers of impinged or entrained organisms. (Author/RE)

  14. Fiber Intake and Childhood Appendicitis.

    ERIC Educational Resources Information Center

    Brender, Jean D.; And Others

    1985-01-01

    Parents of 135 children with appendicitis and of 212 comparison children were interviewed about their children's diet. Results suggest that a liberal intake of whole-grain breads and cereals may decrease the risk of appendicitis during childhood. (KH)

  15. Sodium intake and cardiovascular disease.

    PubMed

    Morrison, Alanna C; Ness, Roberta B

    2011-01-01

    Sodium consumption is a target for prevention of cardiovascular disease (CVD). The relationship between sodium intake and blood pressure (BP) is well-established, but the relationship with CVD is less clear. This review focuses on studies investigating the association between sodium intake and CVD within five principal subgroups: age, underlying BP, gender, body size, and ethnicity. We conclude that sodium reduction results in decreased CVD risk in the general population, and some susceptible subgroups may especially benefit from preventive efforts. Older individuals, those with underlying elevated BP, and those with increased body size may benefit most, but men and women of all ages, ethnicities, and normotensives also experience reduced CVD risk in relation to lowered sodium intake. Public health policy to reduce sodium intake in the United States would have significant cost-savings, far greater than the cost of intervention, and would also result in a significant gain in quality-adjusted life years.

  16. Power Plant Water Intake Assessment.

    ERIC Educational Resources Information Center

    Zeitoun, Ibrahim H.; And Others

    1980-01-01

    In order to adequately assess the impact of power plant cooling water intake on an aquatic ecosystem, total ecosystem effects must be considered, rather than merely numbers of impinged or entrained organisms. (Author/RE)

  17. Childhood obesity and food intake.

    PubMed

    Huang, Jia-Yi; Qi, Sui-Jian

    2015-05-01

    The prevalence of obesity among children is growing in China at present. Childhood obesity reflects complex interactions of genetic, environmental, social and behavioral factors. Foods, nutritional components, and food intake patterns may be associated with the increasing obesity rate in children. Articles about the relationship between childhood obesity and food intake were collected from the databases including Web of Knowledge, PubMed, Elsevier and Google Scholar. Foods and nutritional components such as calcium, dietary fiber are inversely related to obesity, whereas others such as vitamin B and sugar-sweeten beverages play a positive role in obesity development. The differences in food intake pattern also influence the risk of obesity. Food intake is an important factor influencing childhood obesity. One strategy to prevent childhood obesity is to take foods of moderate amount in a proper pattern.

  18. Fiber Intake and Childhood Appendicitis.

    ERIC Educational Resources Information Center

    Brender, Jean D.; And Others

    1985-01-01

    Parents of 135 children with appendicitis and of 212 comparison children were interviewed about their children's diet. Results suggest that a liberal intake of whole-grain breads and cereals may decrease the risk of appendicitis during childhood. (KH)

  19. Ecological study for refrigerator use, salt, vegetable, and fruit intakes, and gastric cancer.

    PubMed

    Park, Boyoung; Shin, Aesun; Park, Sue K; Ko, Kwang-Pil; Ma, Seung Hyun; Lee, Eun-Ha; Gwack, Jin; Jung, En-Joo; Cho, Lisa Y; Yang, Jae Jeong; Yoo, Keun-Young

    2011-11-01

    We used an ecological approach to determine the correlation between vegetable, fruit and salt intakes, refrigerator use, and gastric cancer mortality in Korean population. Information on fruit and vegetable intakes per capita from the National Health and Nutrition Survey, death certificate data from the National Statistical office, refrigerator per household data from Korean Statistical Information Service, and salt/sodium intake data from a cross-sectional survey were utilized. Correlation coefficients were calculated between vegetable and fruit intakes, refrigerator per household, and gastric cancer mortality and between salt and sodium intakes, and gastric cancer mortality and incidence in the four areas. With 5, 10, and 15 years lag time, refrigerator usage and fruit intake were negatively associated with gastric cancer mortality (p < 0.01), but vegetable intake was not associated with gastric cancer mortality. When estimates of salt/sodium intake evaluated by 24-h urine collection in four areas of Korea were compared to the gastric cancer mortality and incidence in these regions, positive correlation was shown between salt/sodium intake, and gastric cancer incidence and mortality. Negative associations between refrigerator use, fruit intake, and gastric cancer mortality and positive associations between salt/sodium intake and gastric cancer mortality and incidence were suggested.

  20. Estimating micronutrient intakes from Household Consumption and Expenditures Surveys (HCES): an example from Bangladesh.

    PubMed

    Bermudez, Odilia I; Lividini, Keith; Smitz, Marc-Francois; Fiedler, John L

    2012-09-01

    Globally, there is a scarcity of national food consumption data that could help to assess food patterns and nutrient intakes of population groups. Estimates of food consumption patterns and apparent intakes of energy and nutrients could be obtained from national Household Consumption and Expenditures Surveys (HCES). To use the HCES conducted in Bangladesh in 2005 (HIES2005) to estimate apparent intakes of vitamin A, iron, and zinc. Food acquisition data from HIES2005, which surveyed 10,080 households, were transformed into standard measurement units. Intrahousehold food and nutrient distribution was estimated with Adult Male Equivalent (AME) units. Adequacy of intake was assessed by comparing individual nutrient intakes with requirements and was then aggregated by households. The weighted mean energy intake for the population was 2,151 kcal/person/day, with a range among divisions from 1,950 in Barisal to 2,195 in Dhaka division. The apparent intakes of vitamin A and iron were insufficient to satisfy the recommended intakes for more than 80% of the population in Bangladesh, while apparent intakes of zinc, adjusted by bioavailability, satisfied the requirements of approximately 60% of the population. Using the HIES2005, we were able to produce estimates of apparent food consumption and intakes of some key micronutrients for the Bangladeshi population and observed wide differences among divisions. However, the methodological approaches reported here, although feasible and promising, need to be validated with other dietary intake methods.

  1. Moderate doses of commercial preparations of Ginkgo biloba do not alter markers of liver function but moderate alcohol intake does: A new approach to identify and quantify biomarkers of 'adverse effects' of dietary supplements.

    PubMed

    Lieberman, Harris R; Kellogg, Mark D; Fulgoni, Victor L; Agarwal, Sanjiv

    2017-03-01

    It is difficult to determine if certain dietary supplements are safe for human consumption. Extracts of leaves of Ginkgo biloba trees are dietary supplements used for various purported therapeutic benefits. However, recent studies reported they increased risk of liver cancer in rodents. Therefore, this study assessed the association between ginkgo consumption and liver function using NHANES 2001-2012 data (N = 29,684). Since alcohol is known to adversely affect liver function, association of its consumption with liver function was also assessed. Alcohol and ginkgo extract intake of adult consumers and clinical markers of liver function (alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase, lactate dehydrogenase, bilirubin) were examined. Moderate consumers of alcohol (0.80 ± 0.02 drinks/day) had higher levels of aspartate aminotransferase and gamma glutamyl transferase than non-consumers (P < 0.001). There was no difference (P > 0.01) in levels of markers of liver function in 616 ginkgo consumers (65.1 ± 4.4 mg/day intake) compared to non-consumers. While moderate alcohol consumption was associated with changes in markers of liver function, ginkgo intake as typically consumed by U.S. adults was not associated with these markers. Biomarkers measured by NHANES may be useful to examine potential adverse effects of dietary supplements for which insufficient human adverse event and toxicity data are available. Not applicable, as this is secondary analysis of publicly released observational data (NHANES 2001-2012). Published by Elsevier Inc.

  2. Constraints and opportunities for implementing nutrition‐specific, agricultural and market‐based approaches to improve nutrient intake adequacy among infants and young children in two regions of rural Kenya

    PubMed Central

    Pelto, Gretel; Armar‐Klemesu, Margaret; Ferguson, Elaine F.; Chege, Peter; Musinguzi, Enock

    2015-01-01

    Abstract Several types of interventions can be used to improve nutrient intake adequacy in infant and young child (IYC) diets, including fortified foods, home fortification, nutrition education and behaviour change communication (BCC) in addition to agricultural and market‐based strategies. However, the appropriate selection of interventions depends on the social, cultural, physical and economic context of the population. Derived from two rural Kenyan populations, this analysis combined information from: (1) a quantitative analysis to derive a set of food‐based recommendations (FBRs) to fill nutrient intake gaps in IYC diets and identify ‘problem nutrients’ for which intake gaps require solutions beyond currently available foods and dietary patterns, and (2) an ethnographic qualitative analysis to identify contextual factors posing opportunities or constraints to implementing the FBRs, including perceptions of cost, convenience, accessibility and appropriateness of the recommended foods for IYC diets and other social or physical factors that determine accessibility of those foods. Opportunities identified included BCC to increase the acceptability and utilisation of green leafy vegetables (GLV) and small fish and agronomic interventions to increase the productivity of GLV and millet. Value chains for millet, beans, GLV, milk and small fish should be studied for opportunities to increase their accessibility in local markets. Processor‐level interventions, such as partially cooked fortified dry porridge mixes or unfortified cereal mixes incorporating millet and beans, may increase the accessibility of foods that provide increased amounts of the problem nutrients. Multi‐sectoral actors and community stakeholders should be engaged to assess the feasibility of implementing these locally appropriate strategies. PMID:26778801

  3. Constraints and opportunities for implementing nutrition-specific, agricultural and market-based approaches to improve nutrient intake adequacy among infants and young children in two regions of rural Kenya.

    PubMed

    Hotz, Christine; Pelto, Gretel; Armar-Klemesu, Margaret; Ferguson, Elaine F; Chege, Peter; Musinguzi, Enock

    2015-12-01

    Several types of interventions can be used to improve nutrient intake adequacy in infant and young child (IYC) diets, including fortified foods, home fortification, nutrition education and behaviour change communication (BCC) in addition to agricultural and market-based strategies. However, the appropriate selection of interventions depends on the social, cultural, physical and economic context of the population. Derived from two rural Kenyan populations, this analysis combined information from: (1) a quantitative analysis to derive a set of food-based recommendations (FBRs) to fill nutrient intake gaps in IYC diets and identify 'problem nutrients' for which intake gaps require solutions beyond currently available foods and dietary patterns, and (2) an ethnographic qualitative analysis to identify contextual factors posing opportunities or constraints to implementing the FBRs, including perceptions of cost, convenience, accessibility and appropriateness of the recommended foods for IYC diets and other social or physical factors that determine accessibility of those foods. Opportunities identified included BCC to increase the acceptability and utilisation of green leafy vegetables (GLV) and small fish and agronomic interventions to increase the productivity of GLV and millet. Value chains for millet, beans, GLV, milk and small fish should be studied for opportunities to increase their accessibility in local markets. Processor-level interventions, such as partially cooked fortified dry porridge mixes or unfortified cereal mixes incorporating millet and beans, may increase the accessibility of foods that provide increased amounts of the problem nutrients. Multi-sectoral actors and community stakeholders should be engaged to assess the feasibility of implementing these locally appropriate strategies.

  4. Antioxidant Vitamin Intake and Mortality

    PubMed Central

    Paganini-Hill, Annlia; Kawas, Claudia H.; Corrada, María M.

    2015-01-01

    To assess the relationship between antioxidant vitamin intake and all-cause mortality in older adults, we examined these associations using data from the Leisure World Cohort Study, a prospective study of residents of the Leisure World retirement community in Laguna Hills, California. In the early 1980s, participants (who were aged 44–101 years) completed a postal survey, which included details on use of vitamin supplements and dietary intake of foods containing vitamins A and C. Age-adjusted and multivariate-adjusted (for factors related to mortality in this cohort—smoking, alcohol intake, caffeine consumption, exercise, body mass index, and histories of hypertension, angina, heart attack, stroke, diabetes, rheumatoid arthritis, and cancer) hazard ratios for death were calculated using Cox regression for 8,640 women and 4,983 men (median age at entry, 74 years). During follow-up (1981–2013), 13,104 participants died (median age at death, 88 years). Neither dietary nor supplemental intake of vitamin A or vitamin C nor supplemental intake of vitamin E was significantly associated with mortality after multivariate adjustment. A compendium that summarizes previous findings of cohort studies evaluating vitamin intake and mortality is provided. Attenuation in the observed associations between mortality and antioxidant vitamin use after adjustment for confounders in our study and in previous studies suggests that such consumption identifies persons with other mortality-associated lifestyle and health risk factors. PMID:25550360

  5. Protein leverage and energy intake.

    PubMed

    Gosby, A K; Conigrave, A D; Raubenheimer, D; Simpson, S J

    2014-03-01

    Increased energy intakes are contributing to overweight and obesity. Growing evidence supports the role of protein appetite in driving excess intake when dietary protein is diluted (the protein leverage hypothesis). Understanding the interactions between dietary macronutrient balance and nutrient-specific appetite systems will be required for designing dietary interventions that work with, rather than against, basic regulatory physiology. Data were collected from 38 published experimental trials measuring ad libitum intake in subjects confined to menus differing in macronutrient composition. Collectively, these trials encompassed considerable variation in percent protein (spanning 8-54% of total energy), carbohydrate (1.6-72%) and fat (11-66%). The data provide an opportunity to describe the individual and interactive effects of dietary protein, carbohydrate and fat on the control of total energy intake. Percent dietary protein was negatively associated with total energy intake (F = 6.9, P < 0.0001) irrespective of whether carbohydrate (F = 0, P = 0.7) or fat (F = 0, P = 0.5) were the diluents of protein. The analysis strongly supports a role for protein leverage in lean, overweight and obese humans. A better appreciation of the targets and regulatory priorities for protein, carbohydrate and fat intake will inform the design of effective and health-promoting weight loss diets, food labelling policies, food production systems and regulatory frameworks.

  6. Identifying Fractions on Number Lines.

    ERIC Educational Resources Information Center

    Bright, George W.; And Others

    1988-01-01

    This study investigated the ways students represented fractions on number lines and the effects of instruction on those representations. The instruction primarily concerned representing fractions and ordering fractions on number lines. (Author/PK)

  7. Fractional Differential Equations and Multifractality

    NASA Astrophysics Data System (ADS)

    Larcheveque, M.; Schertzer, D. J.; Schertzer, D. J.; Duan, J.; Lovejoy, S.

    2001-12-01

    There has been a mushrooming interest in the linear Fokker-Planck Equation (FPPE) which corresponds to the generating equation of Lévy's anomalous diffusion. We already pointed out some theoretical and empirical limitations of the linear FPPE for various geophysical problems: the medium is in fact considered as homogeneous and the exponent of the power law of the pdf tails should be smaller than 2. We showed that a nonlinear extension based on a nonlinear Langevin equation forced by a Lévy stable motion overcomes these limitations. We show that in order to generate multifractal diffusion, and more generally multifractal fields, we need to furthermore consider fractional time derivatives in the Langevin equation and in FPPE. We compare our approach with the Continuous-Time Random Walk (CTWR) approach.

  8. Fractionator feed section

    SciTech Connect

    Sampath, V.R.; Bachmann, D.E.

    1993-07-27

    A fractionator feed section in a fractionator to which is fed a feed mixture comprising a vapor component and a liquid component and which fractionator comprises a tray above said feed section which passes liquid reflux to said feed section, said feed section comprising: (a) a downwardly extending, elongated first baffle; (b) a downwardly extending, elongated second baffle; (c) a seal pan below said first baffle and said second baffle, said seal pan comprising a seal pan mixture of liquids into which a portion of said first baffle and a portion of said second baffle extend to form a mixing zone; (d) a feed nozzle which introduces said liquid component and said vapor component downward into said mixing zone; and, (e) a trough which introduces said liquid reflux to said mixing zone, wherein said liquid component and said liquid reflux mix to form said seal pan mixture of liquids.

  9. Iterated fractional Tikhonov regularization

    NASA Astrophysics Data System (ADS)

    Bianchi, Davide; Buccini, Alessandro; Donatelli, Marco; Serra-Capizzano, Stefano

    2015-05-01

    Fractional Tikhonov regularization methods have been recently proposed to reduce the oversmoothing property of the Tikhonov regularization in standard form, in order to preserve the details of the approximated solution. Their regularization and convergence properties have been previously investigated showing that they are of optimal order. This paper provides saturation and converse results on their convergence rates. Using the same iterative refinement strategy of iterated Tikhonov regularization, new iterated fractional Tikhonov regularization methods are introduced. We show that these iterated methods are of optimal order and overcome the previous saturation results. Furthermore, nonstationary iterated fractional Tikhonov regularization methods are investigated, establishing their convergence rate under general conditions on the iteration parameters. Numerical results confirm the effectiveness of the proposed regularization iterations.

  10. Fractional generalization of Liouville equations.

    PubMed

    Tarasov, Vasily E

    2004-03-01

    In this paper fractional generalization of Liouville equation is considered. We derive fractional analog of normalization condition for distribution function. Fractional generalization of the Liouville equation for dissipative and Hamiltonian systems was derived from the fractional normalization condition. This condition is considered as a normalization condition for systems in fractional phase space. The interpretation of the fractional space is discussed. Copyright 2004 American Institute of Physics.

  11. Some Consequences of Learning Theory Applied to Division of Fractions

    ERIC Educational Resources Information Center

    Bidwell, James K.

    1971-01-01

    Reviews the learning theories of Robert Gagne and David Ausubel, and applies these theories to the three most common approaches to teaching division of fractions: common denominator, complex fraction, and inverse operation methods. Such analysis indicates the inverse approach should be most effective for meaningful teaching, as is verified by…

  12. Some Consequences of Learning Theory Applied to Division of Fractions

    ERIC Educational Resources Information Center

    Bidwell, James K.

    1971-01-01

    Reviews the learning theories of Robert Gagne and David Ausubel, and applies these theories to the three most common approaches to teaching division of fractions: common denominator, complex fraction, and inverse operation methods. Such analysis indicates the inverse approach should be most effective for meaningful teaching, as is verified by…

  13. Peptide fingerprinting of the neurotoxic fractions isolated from the secretions of sea anemones Stichodactyla helianthus and Bunodosoma granulifera. New members of the APETx-like family identified by a 454 pyrosequencing approach.

    PubMed

    Rodríguez, Armando Alexei; Cassoli, Juliana Silva; Sa, Fei; Dong, Zhi Qiang; de Freitas, José Carlos; Pimenta, Adriano M C; de Lima, Maria Elena; Konno, Katsuhiro; Lee, Simon Ming Yuen; Garateix, Anoland; Zaharenko, André J

    2012-03-01

    Sea anemones are known to contain a wide diversity of biologically active peptides, mostly unexplored according to recent peptidomic and transcriptomic studies. In the present work, the neurotoxic fractions from the exudates of Stichodactyla helianthus and Bunodosoma granulifera were analyzed by reversed-phase chromatography and mass spectrometry. The first peptide fingerprints of these sea anemones were assessed, revealing the largest number of peptide components (156) so far found in sea anemone species, as well as the richer peptide diversity of B. granulifera in relation to S. helianthus. The transcriptomic analysis of B. granulifera, performed by massive cDNA sequencing with 454 pyrosequencing approach allowed the discovery of five new APETx-like peptides (U-AITX-Bg1a-e - including the full sequences of their precursors for four of them), which together with type 1 sea anemone sodium channel toxins constitute a very distinguishable feature of studied sea anemone species belonging to genus Bunodosoma. The molecular modeling of these new APETx-like peptides showed a distribution of positively charged and aromatic residues in putative contact surfaces as observed in other animal toxins. On the other hand, they also showed variable electrostatic potentials, thus suggesting a docking onto their targeted channels in different spatial orientations. Moreover several crab paralyzing toxins (other than U-AITX-Bg1a-e), which induce a variety of symptoms in crabs, were isolated. Some of them presumably belong to new classes of crab-paralyzing peptide toxins, especially those with molecular masses below 2kDa, which represent the smallest peptide toxins found in sea anemones. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Release Fraction Evaluation

    SciTech Connect

    Bamberger, Judith A.; Glissmeyer, John A.

    2004-01-01

    This document presents results of experiments conducted to measure release fractions during certain tank retrieval processes. The tests were performed in a 1/4 scale model of a waste storage tank. The retrieval processes simulated were: (1) Discharging liquid or slurry from the mouth of a vertically oriented two-in. Schedule 40 pipe. The discharging material was in free-fall from the mouth of the pipe near the top of the tank into a liquid or slurry pool at the bottom of the tank. (2) The jet from a 9/16-in.-diameter nozzle transferring liquid or slurry waste from one side of the tank to the other. The discharging liquid was aimed at the opposite side of the tank from the nozzle and either impacted the tank wall or fell into a liquid or slurry pool in the bottom of the tank. (3) A high pressure fan jet of liquid striking a steel plate or simulated waste from a stand-off distance of a few inches. For each process, a water-soluble fluorescent dye was added to the liquid fraction as a tracer. Kaolin clay was used to represent the solids. The tank was covered and there was no forced ventilation in the tank during the tests. Six air samples were collected during each test. The air samples were collected at fixed positions in the tank. The air sample filters were dried and weighed to determine the solids collection. The fluorescent dye was then leached from each filter and quantified with a fluorometer to determine the collection of liquid. Samples of the slurry and liquid simulants were also collected to determine the quantities of simulant used in each test. To calculate the release fraction, the quantity collected on each air sample was adjusted for the fraction of the tank volume sampled and divided by the quantity of material exposed in the simulation. The method was not as sensitive for the solids content as it was for the liquid content, but in those instances where a solids release fraction was determined, it was in relatively good agreement with that of the

  15. FRACTIONAL CRYSTALLIZATION FEED ENVELOPE

    SciTech Connect

    HERTING DL

    2008-03-19

    Laboratory work was completed on a set of evaporation tests designed to establish a feed envelope for the fractional crystallization process. The feed envelope defines chemical concentration limits within which the process can be operated successfully. All 38 runs in the half-factorial design matrix were completed successfully, based on the qualitative definition of success. There is no feed composition likely to be derived from saltcake dissolution that would cause the fractional crystallization process to not meet acceptable performance requirements. However, some compositions clearly would provide more successful operation than other compositions.

  16. Estimation of selenium intake in Switzerland in relation to selected food groups.

    PubMed

    Jenny-Burri, J; Haldimann, M; Dudler, V

    2010-11-01

    The selenium concentration in foods was analysed in order to identify principal sources of this trace element in Switzerland. Selenium intake estimations based on three different approaches were carried out. From the relationship between intake and serum/plasma concentration, the selenium intake was estimated to 66 µg day(-1). The second approach based on measured food groups combined with consumption statistics; and the third approach consisted of duplicate meal samples. With the last two methods, over 75% of the serum/plasma based intake was confirmed. Swiss pasta made of North American durum wheat was the food with the highest contribution to the dietary intake, followed by meat. The strong decrease in imports of selenium-rich North American wheat of the last years was not reflected in the present intake estimations. It appears that this intake loss was compensated by a consumption increase of other foods. Compared with former intake estimations, selenium intake seems to be in Switzerland nearly constant for the last 25 years.

  17. In vitro and ex vivo approach for anti-urolithiatic potential of bioactive fractions of gokhru with simultaneous HPLC analysis of six major metabolites and their exploration in rat plasma.

    PubMed

    Sharma, Ikshit; Khan, Washim; Ahmad, Sayeed

    2017-12-01

    Tribulus terrestris L. (Zygophyllaceae) fruits have long been used in traditional systems of medicine for the treatment of various urinary diseases including urolithiasis. To explore the anti-urolithiatic potential of gokhru and to develop an analytical method for quantitative estimation of metabolites for its quality control. Aqueous extract of gokhru fruit was prepared through maceration followed by decoction to produce a mother extract, which was further used for polarity-based fractionations. In vitro and ex vivo anti-urolithiatic activity of mother extract and fractions at different concentration (100-1000 μg/mL) were carried out using aggregation assay in synthetic urine and in rat plasma, however, nucleation assay for 30 min was done using confocal microscopy. A simultaneous HPLC method has been developed for quantification of diosgenin, catechin, rutin, gallic acid, tannic acid and quercetin in mother extract and in fractions. The extraction resulted in 14.5% of w/w mother extract, however, polarity-based fractionation yielded 2.1, 2.6, 1.5, 1.3 and 6.1% w/w of hexane, toluene, dichloromethane (DCM), n-butanol and water fractions, respectively. In vitro and ex vivo studies showed a significant anti-urolithiatic potential of n-butanol fraction. Further, HPLC analysis revealed significantly (p < 0.01) higher content of quercetin (1.95 ± 0.41% w/w), diosgenin (12.75 ± 0.18% w/w) and tannic acid (9.81 ± 0.47% w/w) in n-butanol fraction as compared to others fractions. In vitro and ex vivo studies demonstrated potent anti-urolithiatic activity of n-butanol fraction which can be developed as new phytopharmaceuticals for urolithiasis. HPLC method can be used for quality control and pharmacokinetic studies of gokhru.

  18. Dietary intakes of pesticides based on community duplicate diet samples.

    PubMed

    Melnyk, Lisa Jo; Xue, Jianping; Brown, G Gordon; McCombs, Michelle; Nishioka, Marcia; Michael, Larry C

    2014-01-15

    The calculation of dietary intake of selected pesticides was accomplished using food samples collected from individual representatives of a defined demographic community using a community duplicate diet approach. A community of nine participants was identified in Apopka, FL from which intake assessments of organophosphate (OP) and pyrethroid pesticides were made. From these nine participants, sixty-seven individual samples were collected and subsequently analyzed by gas chromatography/mass spectrometry. Measured concentrations were used to estimate dietary intakes for individuals and for the community. Individual intakes of total OP and pyrethroid pesticides ranged from 6.7 to 996 ng and 1.2 to 16,000 ng, respectively. The community intake was 256 ng for OPs and 3430 ng for pyrethroid pesticides. The most commonly detected pesticide was permethrin, but the highest overall intake was of bifenthrin followed by esfenvalerate. These data indicate that the community in Apopka, FL, as represented by the nine individuals, was potentially exposed to both OP and pyrethroid pesticides at levels consistent with a dietary model and other field studies in which standard duplicate diet samples were collected. Higher levels of pyrethroid pesticides were measured than OPs, which is consistent with decreased usage of OPs. The diversity of pyrethroid pesticides detected in food samples was greater than expected. Continually changing pesticide usage patterns need to be considered when determining analytes of interest for large scale epidemiology studies. The Community Duplicate Diet Methodology is a tool for researchers to meet emerging exposure measurement needs that will lead to more accurate assessments of intake which may enhance decisions for chemical regulation. Successfully determining the intake of pesticides through the dietary route will allow for accurate assessments of pesticide exposures to a community of individuals, thereby significantly enhancing the research benefit

  19. Fractional Adams-Bashforth/Moulton methods: An application to the fractional Keller-Segel chemotaxis system

    NASA Astrophysics Data System (ADS)

    Zayernouri, Mohsen; Matzavinos, Anastasios

    2016-07-01

    We first formulate a fractional class of explicit Adams-Bashforth (A-B) and implicit Adams-Moulton (A-M) methods of first- and second-order accuracy for the time-integration of t τ 0 CD u (x , t) = g (t ; u), τ ∈ (0 , 1 ], where t τ 0 CD #x03c4; 0 C denotes the fractional derivative in the Caputo sense. In this fractional setting and in contrast to the standard Adams methods, an extra history load term emerges and the associated weight coefficients are τ-dependent. However when τ = 1, the developed schemes reduce to the well-known A-B and A-M methods with standard coefficients. Hence, in terms of scientific computing, our approach constitutes a minimal modification of the existing Adams libraries. Next, we develop an implicit-explicit (IMEX) splitting scheme for linear and nonlinear fractional PDEs of a general advection-reaction-diffusion type, and we apply our scheme to the time-space fractional Keller-Segel chemotaxis system. In this context, we evaluate the nonlinear advection term explicitly, employing the fractional A-B method in the prediction step, and we treat the corresponding diffusion term implicitly in the correction step using the fractional A-M scheme. Moreover, we perform the corresponding spatial discretization by employing an efficient and spectrally-accurate fractional spectral collocation method. Our numerical experiments exhibit the efficiency of the proposed IMEX scheme in solving nonlinear fractional PDEs.

  20. Impulsivity, "advergames," and food intake.

    PubMed

    Folkvord, Frans; Anschütz, Doeschka J; Nederkoorn, Chantal; Westerik, Henk; Buijzen, Moniek

    2014-06-01

    Previous studies have focused on the effect of food advertisements on the caloric intake of children. However, the role of individual susceptibility in this effect is unclear. The aim of this study was to examine the role of impulsivity in the effect of advergames that promote energy-dense snacks on children's snack intake. First, impulsivity scores were assessed with a computer task. Then a randomized between-subject design was conducted with 261 children aged 7 to 10 years who played an advergame promoting either energy-dense snacks or nonfood products. As an extra manipulation, half of the children in each condition were rewarded for refraining from eating, the other half were not. Children could eat freely while playing the game. Food intake was measured. The children then completed questionnaire measures, and were weighed and measured. Overall, playing an advergame containing food cues increased general caloric intake. Furthermore, rewarding children to refrain from eating decreased their caloric intake. Finally, rewarding impulsive children to refrain from eating had no influence when they were playing an advergame promoting energy-dense snacks, whereas it did lead to reduced intake among low impulsive children and children who played nonfood advergames. Playing an advergame promoting energy-dense snacks contributes to increased caloric intake in children. The advergame promoting energy-dense snacks overruled the inhibition task to refrain from eating among impulsive children, making it more difficult for them to refrain from eating. The findings suggest that impulsivity plays an important role in susceptibility to food advertisements. Copyright © 2014 by the American Academy of Pediatrics.

  1. Videodisc Instruction in Fractions.

    ERIC Educational Resources Information Center

    Carnine, Douglas; And Others

    1987-01-01

    How laser videodisc technology can be used to improve mathematics instruction is described, with note of the development of a videodisc curriculum on mastering fractions. Relevant research is reviewed, as well as how teachers can use the technology. The instructional design is described, and field-testing and revision reported. (MNS)

  2. Sweet Work with Fractions

    ERIC Educational Resources Information Center

    Vinogradova, Natalya; Blaine, Larry

    2013-01-01

    Almost everyone loves chocolate. However, the same cannot be said about fractions, which are loved by markedly fewer. Middle school students tend to view them with wary respect, but little affection. The authors attempt to sweeten the subject by describing a type of game involving division of chocolate bars. The activity they describe provides a…

  3. Fractional charge search

    SciTech Connect

    Innes, W.; Klein, S.; Perl, M.; Price, J.C.

    1982-06-01

    A device to search for fractional charge in matter is described. The sample is coupled to a low-noise amplifier by a periodically varying capacitor and the resulting signal is synchronously detected. The varying capacitor is constructed as a rapidly spinning wheel. Samples of any material in volumes of up to 0.05 ml may be searched in less than an hour.

  4. Fraction collector for electrophoresis

    NASA Technical Reports Server (NTRS)

    Bier, M.

    1977-01-01

    Rotating-tube electrophoresis apparatus employs rotating jet of eluting buffer to reduce effects of convection during separation. Designed for separation of microorganisms and biological species, system combines gravity/gradient compensating of lumen with buffer flush at fraction outlet to increase separation efficiency.

  5. Fractions through Fruit Salad.

    ERIC Educational Resources Information Center

    Lincoln, Lisa

    1987-01-01

    The mathematics concept of fractions was taught to a group of learning disabled, dyslexic, and multiply handicapped students (15-20 years old) by preparing a fruit salad. Enthusiastic student participation and enhanced knowledge illustrated the effectiveness of employing several sensory modes in learning activities. (CB)

  6. Momentum fractionation on superstrata

    SciTech Connect

    Bena, Iosif; Martinec, Emil; Turton, David; Warner, Nicholas P.

    2016-05-11

    Superstrata are bound states in string theory that carry D1, D5, and momentum charges, and whose supergravity descriptions are parameterized by arbitrary functions of (at least) two variables. In the D1-D5 CFT, typical three-charge states reside in highdegree twisted sectors, and their momentum charge is carried by modes that individually have fractional momentum. Understanding this momentum fractionation holographically is crucial for understanding typical black-hole microstates in this system. We use solution-generating techniques to add momentum to a multi-wound supertube and thereby construct the first examples of asymptotically-flat superstrata. The resulting supergravity solutions are horizonless and smooth up to well-understood orbifold singularities. Upon taking the AdS3 decoupling limit, our solutions are dual to CFT states with momentum fractionation. We give a precise proposal for these dual CFT states. Lastly, our construction establishes the very nontrivial fact that large classes of CFT states with momentum fractionation can be realized in the bulk as smooth horizonless supergravity solutions.

  7. Field-Flow Fractionation.

    ERIC Educational Resources Information Center

    Caldwell, Karin D.

    1988-01-01

    Describes a technique for separating samples that range over 15 orders of magnitude in molecular weight. Discusses theory, apparatus, and sample preparation techniques. Lists several types of field-flow fractionation (FFF) and their uses: sedimentation FFF, thermal FFF, flow FFF, electrical FFF, and steric FFF. (ML)

  8. Sweet Work with Fractions

    ERIC Educational Resources Information Center

    Vinogradova, Natalya; Blaine, Larry

    2013-01-01

    Almost everyone loves chocolate. However, the same cannot be said about fractions, which are loved by markedly fewer. Middle school students tend to view them with wary respect, but little affection. The authors attempt to sweeten the subject by describing a type of game involving division of chocolate bars. The activity they describe provides a…

  9. Momentum fractionation on superstrata

    DOE PAGES

    Bena, Iosif; Martinec, Emil; Turton, David; ...

    2016-05-11

    Superstrata are bound states in string theory that carry D1, D5, and momentum charges, and whose supergravity descriptions are parameterized by arbitrary functions of (at least) two variables. In the D1-D5 CFT, typical three-charge states reside in highdegree twisted sectors, and their momentum charge is carried by modes that individually have fractional momentum. Understanding this momentum fractionation holographically is crucial for understanding typical black-hole microstates in this system. We use solution-generating techniques to add momentum to a multi-wound supertube and thereby construct the first examples of asymptotically-flat superstrata. The resulting supergravity solutions are horizonless and smooth up to well-understood orbifoldmore » singularities. Upon taking the AdS3 decoupling limit, our solutions are dual to CFT states with momentum fractionation. We give a precise proposal for these dual CFT states. Lastly, our construction establishes the very nontrivial fact that large classes of CFT states with momentum fractionation can be realized in the bulk as smooth horizonless supergravity solutions.« less

  10. Measuring Outdoor Air Intake Rates into Existing Building

    SciTech Connect

    Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

    2009-04-16

    Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10 percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15 percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100 percent, and were often greater than 25 percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

  11. Density-Functional Theory of the Fractional Quantum Hall Effect.

    PubMed

    Zhao, Jianyun; Thakurathi, Manisha; Jain, Manish; Sen, Diptiman; Jain, J K

    2017-05-12

    A conceptual difficulty in formulating the density-functional theory of the fractional quantum Hall effect is that while in the standard approach the Kohn-Sham orbitals are either fully occupied or unoccupied, the physics of the fractional quantum Hall effect calls for fractionally occupied Kohn-Sham orbitals. This has necessitated averaging over an ensemble of Slater determinants to obtain meaningful results. We develop an alternative approach in which we express and minimize the grand canonical potential in terms of the composite fermion variables. This provides a natural resolution of the fractional-occupation problem because the fully occupied orbitals of composite fermions automatically correspond to fractionally occupied orbitals of electrons. We demonstrate the quantitative validity of our approach by evaluating the density profile of fractional Hall edge as a function of temperature and the distance from the delta dopant layer and showing that it reproduces edge reconstruction in the expected parameter region.

  12. The fractional-nonlinear robotic manipulator: Modeling and dynamic simulations

    NASA Astrophysics Data System (ADS)

    David, S. A.; Balthazar, J. M.; Julio, B. H. S.; Oliveira, C.

    2012-11-01

    In this paper, we applied the Riemann-Liouville approach and the fractional Euler-Lagrange equations in order to obtain the fractional-order nonlinear dynamics equations of a two link robotic manipulator. The aformentioned equations have been simulated for several cases involving: integer and non-integer order analysis, with and without external forcing acting and some different initial conditions. The fractional nonlinear governing equations of motion are coupled and the time evolution of the angular positions and the phase diagrams have been plotted to visualize the effect of fractional order approach. The new contribution of this work arises from the fact that the dynamics equations of a two link robotic manipulator have been modeled with the fractional Euler-Lagrange dynamics approach. The results reveal that the fractional-nonlinear robotic manipulator can exhibit different and curious behavior from those obtained with the standard dynamical system and can be useful for a better understanding and control of such nonlinear systems.

  13. Density-Functional Theory of the Fractional Quantum Hall Effect

    NASA Astrophysics Data System (ADS)

    Zhao, Jianyun; Thakurathi, Manisha; Jain, Manish; Sen, Diptiman; Jain, J. K.

    2017-05-01

    A conceptual difficulty in formulating the density-functional theory of the fractional quantum Hall effect is that while in the standard approach the Kohn-Sham orbitals are either fully occupied or unoccupied, the physics of the fractional quantum Hall effect calls for fractionally occupied Kohn-Sham orbitals. This has necessitated averaging over an ensemble of Slater determinants to obtain meaningful results. We develop an alternative approach in which we express and minimize the grand canonical potential in terms of the composite fermion variables. This provides a natural resolution of the fractional-occupation problem because the fully occupied orbitals of composite fermions automatically correspond to fractionally occupied orbitals of electrons. We demonstrate the quantitative validity of our approach by evaluating the density profile of fractional Hall edge as a function of temperature and the distance from the delta dopant layer and showing that it reproduces edge reconstruction in the expected parameter region.

  14. Macronutrient intake and stomach cancer.

    PubMed

    Hu, Jinfu; La Vecchia, Carlo; Negri, Eva; de Groh, Margaret; Morrison, Howard; Mery, Les

    2015-06-01

    This study examines the association between intake of selected macronutrients and the risk of stomach cancer in a Northern American population. Mailed questionnaires were completed between 1994 and 1997 in eight Canadian provinces by 1,181 incident, histologically confirmed cases of stomach cancer and 5,039 population controls. Information on nutrient intake was obtained using a food frequency questionnaire. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were derived through unconditional logistic regression to adjust for potential confounders, including an estimate of total energy intake. Intakes of total fat, saturated fat, and cholesterol were significantly associated with the risk of stomach cancer: The ORs for the highest versus the lowest quartile were 1.58 (95% CI 1.13-2.20), 1.86 (95% CI 1.37-2.52), and 1.75 (95% CI 1.36-2.25), respectively. Total fiber was inversely associated with stomach cancer (p = 0.03). The positive associations with intake of total fat and saturated fat were apparently stronger in women, overweight or obese subjects, and ever smokers. Saturated fat was specifically associated with increased risk of gastric cardia cancer, with an OR of 3.31 (95% CI 1.48-7.43). A diet high in saturated fat appears to increase the risk of stomach cancer, particularly among obese subjects and for gastric cardia cancer.

  15. Neuroendocrine control of food intake.

    PubMed

    Park, Adrian J; Bloom, Stephen R

    2005-03-01

    Obesity is a major public health problem and substantially increases the risk of type 2 diabetes, hypertension, stroke, cardiovascular, respiratory problems, gall bladder disease, osteoarthritis and sleep apnoea, as well as certain cancers. The prevalence of obesity is rapidly increasing worldwide. However, for individuals weight is regulated within a narrow range. This regulation depends on energy intake (in the form of food) and energy expenditure. Recently, there has been a remarkable increase in our understanding of the homeostatic mechanisms that control food intake and energy homeostasis. There is increased understanding of the central regulation of appetite. In particular, this includes new knowledge about the hypothalamus and brainstem and their relation to food intake regulation. Peripheral hormones (notably adipostat factors and gut hormones) have now been found to be important in food intake regulation. Complex central circuitry controls food intake. Circulating hormones, in particular the gut hormones have unexpectedly been found to be very important in appetite control. The gut hormones are thus new and exciting targets for future obesity therapies.

  16. Nutrition knowledge and food intake.

    PubMed

    Wardle, J; Parmenter, K; Waller, J

    2000-06-01

    In many studies, correlations between nutrition knowledge and dietary behaviour have failed to reach statistical significance, leading researchers to question the relevance of nutrition knowledge to food choice, and the value of nutrition education campaigns. This study aimed to investigate the relationship between knowledge and intake of fat, fruit and vegetables using a well-validated measure of nutrition knowledge. The study was a postal survey, using 1040 adult participants selected at random from General Practitioners' lists in England. Nutrition knowledge and food intake followed the expected demographic patterns. Knowledge was significantly associated with healthy eating, and the effect persisted after controlling for demographic variables. Logistic regression showed that respondents in the highest quintile for knowledge were almost 25 times more likely to meet current recommendations for fruit, vegetable and fat intake than those in the lowest quintile. Nutrition knowledge was shown to be a partial mediator of the socio-demographic variation in intake, especially for fruit and vegetables. This demonstrates the value of using more sophisticated statistical techniques to investigate associations between knowledge and food intake and indicates that knowledge is an important factor in explaining variations in food choice. The results support the likely value of including nutrition knowledge as a target for health education campaigns aimed at promoting healthy eating.

  17. Energy density, energy intake regulation and body weight

    USDA-ARS?s Scientific Manuscript database

    Obesity is one of the major health crises of our time. The majority of adult Americans are now either overweight or obese, and recent research indicates that obesity is approaching smoking as the major cause of disability and premature death. National improvements in dietary intake, and in particu...

  18. Goal Sketches in Fraction Learning

    ERIC Educational Resources Information Center

    Sophian, Catherine; Madrid, Samara

    2003-01-01

    To examine how conceptual knowledge about fraction magnitudes changes as students' learning progresses, 5th and 7th-grade students were asked to solve fraction magnitude problems that entailed finding a fraction between two given fractions and then to evaluate solutions for similar problems that were modeled for them. When the given fractions…

  19. Creating, Naming, and Justifying Fractions

    ERIC Educational Resources Information Center

    Siebert, Daniel; Gaskin, Nicole

    2006-01-01

    For students to develop meaningful conceptions of fractions and fraction operations, they need to think of fractions in terms other than as just whole-number combinations. In this article, we suggest two powerful images for thinking about fractions that move beyond whole-number reasoning. (Contains 5 figures.)

  20. Local food-based complementary feeding recommendations developed by the linear programming approach to improve the intake of problem nutrients among 12-23-month-old Myanmar children.

    PubMed

    Hlaing, Lwin Mar; Fahmida, Umi; Htet, Min Kyaw; Utomo, Budi; Firmansyah, Agus; Ferguson, Elaine L

    2016-07-01

    Poor feeding practices result in inadequate nutrient intakes in young children in developing countries. To improve practices, local food-based complementary feeding recommendations (CFR) are needed. This cross-sectional survey aimed to describe current food consumption patterns of 12-23-month-old Myanmar children (n 106) from Ayeyarwady region in order to identify nutrient requirements that are difficult to achieve using local foods and to formulate affordable and realistic CFR to improve dietary adequacy. Weekly food consumption patterns were assessed using a 12-h weighed dietary record, single 24-h recall and a 5-d food record. Food costs were estimated by market surveys. CFR were formulated by linear programming analysis using WHO Optifood software and evaluated among mothers (n 20) using trial of improved practices (TIP). Findings showed that Ca, Zn, niacin, folate and Fe were 'problem nutrients': nutrients that did not achieve 100 % recommended nutrient intake even when the diet was optimised. Chicken liver, anchovy and roselle leaves were locally available nutrient-dense foods that would fill these nutrient gaps. The final set of six CFR would ensure dietary adequacy for five of twelve nutrients at a minimal cost of 271 kyats/d (based on the exchange rate of 900 kyats/USD at the time of data collection: 3rd quarter of 2012), but inadequacies remained for niacin, folate, thiamin, Fe, Zn, Ca and vitamin B6. TIP showed that mothers believed liver and vegetables would cause worms and diarrhoea, but these beliefs could be overcome to successfully promote liver consumption. Therefore, an acceptable set of CFR were developed to improve the dietary practices of 12-23-month-old Myanmar children using locally available foods. Alternative interventions such as fortification, however, are still needed to ensure dietary adequacy of all nutrients.

  1. Food intake and nutrition in children 1-4 years of age in Yucatan, Mexico.

    PubMed

    Cuanalo de la Cerda, Heriberto E; Ochoa Estrada, Ernesto; Tuz Poot, Felipe R; Datta Banik, Sudip

    2014-01-01

    The National Health and Nutrition Survey 2006 (ENSANUT in Spanish) reported high rates of under-nutrition in children of Yucatan. Is food intake the main cause of under-nutrition in children of the state of Yucatan, Mexico? Identify the primary causes of under-nutrition in pre-school children in Yucatan. A sample of 111 children (59 girls and 52 boys) aged 1-4 years representing Yucatan was taken from a database of ENSANUT 2006 and another national survey, a federal poverty mitigation programme for the state of Yucatan, Mexico entitled "Oportunidades". A human ecology approach together with life history theory was used to analyse anthropometric indices and food intake data from the ENSANUT 2006 and "Oportunidades". Height and weight were significantly correlated to age and total food intake. No correlations were found between age and anthropometric indices or food intake rates. The children in the sample had adequate protein intake but deficient energy intake. No correlation was identified between nutritional status and food intake rates. Pre-schoolers with higher weight-for-height values achieved greater height-for-age. These relationships can be explained by life history theory in that energy intake was used either for maintenance (combating and recovering from infections) or growth. The poor relationship between food intake rates and nutritional status is probably explained by the interaction between high disease incidence and insufficient energy intake. These conditions are endemic in Yucatan due to widespread poor housing, water and sanitation conditions.

  2. Arbitrage with fractional Gaussian processes

    NASA Astrophysics Data System (ADS)

    Zhang, Xili; Xiao, Weilin

    2017-04-01

    While the arbitrage opportunity in the Black-Scholes model driven by fractional Brownian motion has a long history, the arbitrage strategy in the Black-Scholes model driven by general fractional Gaussian processes is in its infancy. The development of stochastic calculus with respect to fractional Gaussian processes allowed us to study such models. In this paper, following the idea of Shiryaev (1998), an arbitrage strategy is constructed for the Black-Scholes model driven by fractional Gaussian processes, when the stochastic integral is interpreted in the Riemann-Stieltjes sense. Arbitrage opportunities in some fractional Gaussian processes, including fractional Brownian motion, sub-fractional Brownian motion, bi-fractional Brownian motion, weighted-fractional Brownian motion and tempered fractional Brownian motion, are also investigated.

  3. Gastrointestinal regulation of food intake

    PubMed Central

    Cummings, David E.; Overduin, Joost

    2007-01-01

    Despite substantial fluctuations in daily food intake, animals maintain a remarkably stable body weight, because overall caloric ingestion and expenditure are exquisitely matched over long periods of time, through the process of energy homeostasis. The brain receives hormonal, neural, and metabolic signals pertaining to body-energy status and, in response to these inputs, coordinates adaptive alterations of energy intake and expenditure. To regulate food consumption, the brain must modulate appetite, and the core of appetite regulation lies in the gut-brain axis. This Review summarizes current knowledge regarding the neuroendocrine regulation of food intake by the gastrointestinal system, focusing on gastric distention, intestinal and pancreatic satiation peptides, and the orexigenic gastric hormone ghrelin. We highlight mechanisms governing nutrient sensing and peptide secretion by enteroendocrine cells, including novel taste-like pathways. The increasingly nuanced understanding of the mechanisms mediating gut-peptide regulation and action provides promising targets for new strategies to combat obesity and diabetes. PMID:17200702

  4. Dietary intake and body composition of football players during the holy month of Ramadan.

    PubMed

    Maughan, Ronald J; Bartagi, Zakia; Dvorak, Jiri; Zerguini, Yacine

    2008-12-01

    Healthy young male football players who were either fasting (n = 59) or not fasting (n = 36) during the month of Ramadan were studied. Body mass, body composition, and dietary intake were assessed at each time point. Energy intake was relatively stable in the fasting participants, but there was a small decrease of approximately 0.7 kg in body mass during Ramadan. Mean daily energy intake increased from 14.8 MJ (s = 2.9) to 18.1 MJ (s = 3.2) during Ramadan in non-fasting participants, with concomitant increases in body mass and body fat content of about 1.4 kg and 1% respectively over the month. The fractional intake of protein increased and the fractional contribution of carbohydrate decreased for both groups in Ramadan. Estimated mean daily water intake was high (about 3.8 litres) throughout the study period. Water intake increased on average by 1.3 litres . day(-1) in line with the greater energy intake in the non-fasting group in Ramadan. Daily sodium intake fell during Ramadan in the fasting participants from 5.4 g (s = 1.1) before Ramadan to 4.3 g (s = 1.0) during Ramadan, but increased slightly by about 0.7 g . day(-1) in the non-fasting group. Dietary iron decreased in the fasting group and increased in the non-fasting group, reflecting the difference in energy intake in both groups during Ramadan. These data suggest that Ramadan fasting had some effects on diet composition, but the effects were generally small even though the pattern of eating was very different. After Ramadan, the dietary variables reverted to the pre-Ramadan values.

  5. Floquet Fractional Chern Insulators

    NASA Astrophysics Data System (ADS)

    Grushin, Adolfo G.; Gómez-León, Álvaro; Neupert, Titus

    2014-04-01