7,039 research outputs found

    Associations between mothers’ perceptions of the cost of fruit and vegetables and children’s diets : Will children pay the price?

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    Background/Objectives: Perceptions that fruit and vegetables are expensive are more common among the socio-economically disadvantaged groups and are linked to poor dietary outcomes. Such perceptions may be exacerbated in countries recently affected by natural disasters, where devastation of fruit and vegetable crops has resulted in increase in prices of fruit and vegetables. Examining the associations of perceptions of fruit and vegetable affordability and children\u27s diets can offer insights into how the high prices of fruit and vegetables might have an impact on the diets of children.Subjects/Methods: We analysed the data from 546 socio-economically disadvantaged mother&ndash;child pairs to assess the relationship between maternal perceptions of fruit and vegetable affordability and the diets of their children.Results: Fruit consumption was lower among children whose mothers felt the cost of fruit was too high. Maternal perceptions of fruit and vegetable affordability were not associated with any other aspect of child\u27s diet.Conclusions: Our results suggest a possible role for maternal perceptions of fruit affordability in children\u27s diet, though further research is warranted.<br /

    Counting and computing regions of DD-decomposition: algebro-geometric approach

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    New methods for DD-decomposition analysis are presented. They are based on topology of real algebraic varieties and computational real algebraic geometry. The estimate of number of root invariant regions for polynomial parametric families of polynomial and matrices is given. For the case of two parametric family more sharp estimate is proven. Theoretic results are supported by various numerical simulations that show higher precision of presented methods with respect to traditional ones. The presented methods are inherently global and could be applied for studying DD-decomposition for the space of parameters as a whole instead of some prescribed regions. For symbolic computations the Maple v.14 software and its package RegularChains are used.Comment: 16 pages, 8 figure

    Polynomial-Time Amoeba Neighborhood Membership and Faster Localized Solving

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    We derive efficient algorithms for coarse approximation of algebraic hypersurfaces, useful for estimating the distance between an input polynomial zero set and a given query point. Our methods work best on sparse polynomials of high degree (in any number of variables) but are nevertheless completely general. The underlying ideas, which we take the time to describe in an elementary way, come from tropical geometry. We thus reduce a hard algebraic problem to high-precision linear optimization, proving new upper and lower complexity estimates along the way.Comment: 15 pages, 9 figures. Submitted to a conference proceeding

    Solarization in a forest nursery : Effect on ectomycorrhizal soil infectivity and soil receptiveness to inoculation with Laccaria bicolor

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    Field experiments were carried out in a forest nursery during the summer of 1994 to examine the effect of soil solarization on ectomycorrhizal soil infectivity (ESI) and soil receptiveness to inoculation with Laccaria bicolor. Soil samples from solarized, steamed, fumigated and untreated plots were periodically collected and assayed for ESI. Untreated soil exhibited high ESI. Solarization was as effective as steaming or fumigation in reducing ESI in the uppermost layer. Solarization with a double layer of polyethylene film and fumigation were the only treatments which reduced ESI deeper in the soil. During July, the temperature of covered beds reached 50 °C at a soil depth of 5 cm. Ectomycorrhizal fungi were among the soil-borne fungi most sensitive to solar heating. Soil solarization provides an effective disinfection method for controlled mycorrhization in forest nurseries.Facultad de Ciencias Agrarias y Forestale

    Foregut microbiome in development of esophageal adenocarcinoma

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    Esophageal adenocarcinoma (EA), the type of cancer linked to heartburn due to gastroesophageal reflux diseases (GERD), has increased six fold in the past 30 years. This cannot currently be explained by the usual environmental or by host genetic factors. EA is the end result of a sequence of GERD-related diseases, preceded by reflux esophagitis (RE) and Barrett&#x2019;s esophagus (BE). Preliminary studies by Pei and colleagues at NYU on elderly male veterans identified two types of microbiotas in the esophagus. Patients who carry the type II microbiota are &#x3e;15 fold likely to have esophagitis and BE than those harboring the type I microbiota. In a small scale study, we also found that 3 of 3 cases of EA harbored the type II biota. The findings have opened a new approach to understanding the recent surge in the incidence of EA. &#xd;&#xa;&#xd;&#xa;Our long-term goal is to identify the cause of GERD sequence. The hypothesis to be tested is that changes in the foregut microbiome are associated with EA and its precursors, RE and BE in GERD sequence. We will conduct a case control study to demonstrate the microbiome disease association in every stage of GERD sequence, as well as analyze the trend in changes in the microbiome along disease progression toward EA, by two specific aims. Aim 1 is to conduct a comprehensive population survey of the foregut microbiome and demonstrate its association with GERD sequence. Furthermore, spatial relationship between the esophageal microbiota and upstream (mouth) and downstream (stomach) foregut microbiotas as well as temporal stability of the microbiome-disease association will also be examined. Aim 2 is to define the distal esophageal metagenome and demonstrate its association with GERD sequence. Detailed analyses will include pathway-disease and gene-disease associations. Archaea, fungi and viruses, if identified, also will be correlated with the diseases. A significant association between the foregut microbiome and GERD sequence, if demonstrated, will be the first step for eventually testing whether an abnormal microbiome is required for the development of the sequence of phenotypic changes toward EA. If EA and its precursors represent a microecological disease, treating the cause of GERD might become possible, for example, by normalizing the microbiota through use of antibiotics, probiotics, or prebiotics. Causative therapy of GERD could prevent its progression and reverse the current trend of increasing incidence of EA

    Mortar FEs on Overlapping Meshes : Application to Magnetodynamics

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    Abstract The finite element (FE) method is frequently used in magnetodynamics as well suited to treat problems with complex geometries while keeping a simplicity in the implementation. However, some modelisations, as in eddy current (EC) non destructive testing (NDT), present the particularity to have moving parts. A global remeshing can be necessary which causes expensive CPU time. Domain decomposition methods allowing to take into account the movement without having to remesh the whole computational domain. The mortar element method (MEM), a variational non-conforming domain decomposition approach [1] offers attractive advantages in terms of flexibility and accuracy. In its original version for non-overlapping subdomains, the information is transferred through the skeleton of the decomposition by means of a suitable L 2 -projection of the field trace from the master to the slave subdomains. A MEM with overlapping subdomains has been proposed to coupled a global scalar potential defined everywhere in the considered domain and a local vector potential defined only in (possibly moving) conductor

    Non-Parametric Approximations for Anisotropy Estimation in Two-dimensional Differentiable Gaussian Random Fields

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    Spatially referenced data often have autocovariance functions with elliptical isolevel contours, a property known as geometric anisotropy. The anisotropy parameters include the tilt of the ellipse (orientation angle) with respect to a reference axis and the aspect ratio of the principal correlation lengths. Since these parameters are unknown a priori, sample estimates are needed to define suitable spatial models for the interpolation of incomplete data. The distribution of the anisotropy statistics is determined by a non-Gaussian sampling joint probability density. By means of analytical calculations, we derive an explicit expression for the joint probability density function of the anisotropy statistics for Gaussian, stationary and differentiable random fields. Based on this expression, we obtain an approximate joint density which we use to formulate a statistical test for isotropy. The approximate joint density is independent of the autocovariance function and provides conservative probability and confidence regions for the anisotropy parameters. We validate the theoretical analysis by means of simulations using synthetic data, and we illustrate the detection of anisotropy changes with a case study involving background radiation exposure data. The approximate joint density provides (i) a stand-alone approximate estimate of the anisotropy statistics distribution (ii) informed initial values for maximum likelihood estimation, and (iii) a useful prior for Bayesian anisotropy inference.Comment: 39 pages; 8 figure

    Analytic Metaphysics versus Naturalized Metaphysics: The Relevance of Applied Ontology

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    The relevance of analytic metaphysics has come under criticism: Ladyman & Ross, for instance, have suggested do discontinue the field. French & McKenzie have argued in defense of analytic metaphysics that it develops tools that could turn out to be useful for philosophy of physics. In this article, we show first that this heuristic defense of metaphysics can be extended to the scientific field of applied ontology, which uses constructs from analytic metaphysics. Second, we elaborate on a parallel by French & McKenzie between mathematics and metaphysics to show that the whole field of analytic metaphysics, being useful not only for philosophy but also for science, should continue to exist as a largely autonomous field

    Fundamental representations and algebraic properties of biquaternions or complexified quaternions

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    The fundamental properties of biquaternions (complexified quaternions) are presented including several different representations, some of them new, and definitions of fundamental operations such as the scalar and vector parts, conjugates, semi-norms, polar forms, and inner and outer products. The notation is consistent throughout, even between representations, providing a clear account of the many ways in which the component parts of a biquaternion may be manipulated algebraically
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