849 research outputs found

    Involution of the mouse mammary gland is associated with an immune cascade and an acute-phase response, involving LBP, CD14 and STAT3

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    INTRODUCTION: Involution of the mammary gland is a complex process of controlled apoptosis and tissue remodelling. The aim of the project was to identify genes that are specifically involved in this process. METHODS: We used Affymetrix oligonucleotide microarrays to perform a detailed transcript analysis on the mechanism of controlled involution after withdrawal of the pups at day seven of lactation. Some of the results were confirmed by semi-quantitative reverse transcriptase polymerase chain reaction, Western blotting or immunohistochemistry. RESULTS: We identified 145 genes that were specifically upregulated during the first 4 days of involution; of these, 49 encoded immunoglobulin genes. A further 12 genes, including those encoding the signal transducer and activator of transcription 3 (STAT3), the lipopolysaccharide receptor (CD14) and lipopolysaccharide-binding protein (LBP), were involved in the acute-phase response, demonstrating that the expression of acute-phase response genes can occur in the mammary gland itself and not only in the liver. Expression of LBP and CD14 was upregulated, at both the RNA and protein level, immediately after pup withdrawal; CD14 was strongly expressed in the luminal epithelial cells. Other genes identified suggested neutrophil activation early in involution, followed by macrophage activation late in the process. Immunohistochemistry and histological staining confirmed the infiltration of the involuting mammary tissue with neutrophils, plasma cells, macrophages and eosinophils. CONCLUSION: Oligonucleotide microarrays are a useful tool for identifying genes that are involved in the complex developmental process of mammary gland involution. The genes identified are consistent with an immune cascade, with an early acute-phase response that occurs in the mammary gland itself and resembles a wound healing process

    Supermarket Transaction Records In Dietary Evaluation – The STRIDE study: validation against self-reported dietary intake

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    Objective: Scalable methods are required for population dietary monitoring. The Supermarket Transaction Records In Dietary Evaluation (STRIDE) study compares dietary estimates from supermarket transactions with an online FFQ. Design: Participants were recruited in four waves, accounting for seasonal dietary variation. Purchases were collected for 1 year during and 1 year prior to the study. Bland–Altman agreement and limits of agreement (LoA) were calculated for energy, sugar, fat, saturated fat, protein and sodium (absolute and relative). Setting: This study was partnered with a large UK retailer. Participants: Totally, 1788 participants from four UK regions were recruited from the retailer’s loyalty card customer database, according to breadth and frequency of purchases. Six hundred and eighty-six participants were included for analysis. Results: The analysis sample were mostly female (72 %), with a mean age of 56 years (SD 13). The ratio of purchases to intakes varied depending on amounts purchased and consumed; purchases under-estimated intakes for smaller amounts on average, but over-estimated for larger amounts. For absolute measures, the LoA across households were wide, for example, for energy intake of 2000 kcal, purchases could under- or over-estimate intake by a factor of 5; values could be between 400 kcal and 10000 kcal. LoA for relative (energy-adjusted) estimates were smaller, for example, for 14 % of total energy from saturated fat, purchase estimates may be between 7 % and 27 %. Conclusions: Agreement between purchases and intake was highly variable, strongest for smaller loyal households and for relative values. For some customers, relative nutrient purchases are a reasonable proxy for dietary composition indicating utility in population-level dietary research

    Instantons and the endpoint of the lepton energy spectrum in charmless semileptonic BB decays

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    A recent calculation by Chay and Rey has shown that instantons may make a significant contribution to the lepton energy spectrum near its endpoint. Using an ansatz borrowed from the study of high energy baryon number violating processes, we investigate whether these corrections could spoil the relation between the nonperturbative contributions to this spectrum and to the photon energy spectrum in radiative BB decays. We find, in general, that this universality may well fail unless the spectrum is smeared over a region which is considerably larger than had previously been thought necessary. This result affects the possibility of performing a reliable measurement of VubV_{ub} using inclusive decays.Comment: Slightly revised version, to appear in Phys. Rev. D. A few additional comments have been added on the approximations which are used. 13 pages, 2 embedded uuencoded figures, uses REVTe

    Efficient Algorithm on a Non-staggered Mesh for Simulating Rayleigh-Benard Convection in a Box

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    An efficient semi-implicit second-order-accurate finite-difference method is described for studying incompressible Rayleigh-Benard convection in a box, with sidewalls that are periodic, thermally insulated, or thermally conducting. Operator-splitting and a projection method reduce the algorithm at each time step to the solution of four Helmholtz equations and one Poisson equation, and these are are solved by fast direct methods. The method is numerically stable even though all field values are placed on a single non-staggered mesh commensurate with the boundaries. The efficiency and accuracy of the method are characterized for several representative convection problems.Comment: REVTeX, 30 pages, 5 figure

    Tree method for quantum vortex dynamics

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    We present a numerical method to compute the evolution of vortex filaments in superfluid helium. The method is based on a tree algorithm which considerably speeds up the calculation of Biot-Savart integrals. We show that the computational cost scales as Nlog{(N) rather than N squared, where NN is the number of discretization points. We test the method and its properties for a variety of vortex configurations, ranging from simple vortex rings to a counterflow vortex tangle, and compare results against the Local Induction Approximation and the exact Biot-Savart law.Comment: 12 pages, 10 figure

    New Lump-like Structures in Scalar-field Models

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    In this work we investigate lump-like solutions in models described by a single real scalar field. We start considering non-topological solutions with the usual lump-like form, and then we study other models, where the bell-shape profile may have varying amplitude and width, or develop a flat plateau at its top, or even induce a lump on top of another lump. We suggest possible applications where these exotic solutions might be used in several distinct branches of physics.Comment: REvTex4, twocolumn, 10 pages, 9 figures; new reference added, to appear in EPJ

    The sensitivity of the vortex filament method to different reconnection models

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    We present a detailed analysis on the effect of using different algorithms to model the reconnection of vortices in quantum turbulence, using the thin-filament approach. We examine differences between four main algorithms for the case of turbulence driven by a counterflow. In calculating the velocity field we use both the local induction approximation (LIA) and the full Biot-Savart integral. We show that results of Biot-Savart simulations are not sensitive to the particular reconnection method used, but LIA results are.Comment: 9 pages, 9 figure

    COMBINING ABILITY AND HETEROTIC PATTERN IN WEST AFRICAN SORGHUM LANDRACES

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    Heterotic grouping based on combining ability for traits of interest, in addition to plant performance and genetic relationship among germplasm, would be useful in planning crosses in breeding programmes. This study aimed at determining the combining abilities of selected landraces for morphological and physiological traits under contrasted environments and identifying the suitable heterotic grouping method for superior hybrid production. For this purpose, nineteen accessions representing different origins and population structure among West African Sorghum Accessions Panel (WASAP) and two female lines, were used in \uab\ua0Line x tester\ua0\ubb mating design to produce thirty-eight (38) hybrids. Analysis of variance showed significant general combining ability and specific combining ability effects for grain weight, plant height, days to flowering, panicle length and chlorophyll content implying existence of heterotic responses for these traits. Both additive and non-additive gene effects were important in controlling the inheritance of the traits. Parents K31.3, K37 and Ni331 were the best combiners for grain weight, providing the opportunity for breeders to improve grain yield under diverse environments. AVG-1 x K31.3 and AVG-1 x Tg148 were the superior hybrids. Combining ability based heterotic grouping methods classified sorghum accessions into four groups. The heterotic group\u2019s specific and general combining ability (HSGCA) method was the suitable in predicting hybrid superiority. This combining abilities based heterotic grouping study is an additional tool that breeders could use to identify the best parents for superior hybrids development in West Africa.La d\ue9termination des groupes h\ue9t\ue9rotiques bas\ue9e sur les aptitudes \ue0 la combinaison des traits d\u2019int\ue9r\ueat en plus des performances et des relations g\ue9n\ue9tiques dans une collection est importante pour planifier les croisements en s\ue9lection. Cette visait la d\ue9termination des aptitudes \ue0 la combinaison des accessions locales pour certains traits morphologiques sous environnements contrast\ue9s et l\u2019identification de la meilleure m\ue9thode dans la pr\ue9diction de la vigueur hybride. Dans cette perspective, dix-neuf accessions repr\ue9sentant diff\ue9rentes origines et la structure de la population d\u2019un panel ouest africain de sorgho (WASAP) et deux m\ue2les st\ue9riles ont \ue9t\ue9 utilis\ue9s dans un croisement \uab\ua0Line x tester\ua0\ubb pour produire trente-huit hybrides F1, objet de cette \ue9tude. L\u2019analyse de variance a indiqu\ue9 des effets significatifs de l\u2019aptitude g\ue9n\ue9rale et sp\ue9cifique \ue0 la combinaison pour le poids grain, la hauteur plante, la dur\ue9e semis floraison et la concentration en chlorophylle traduisant l\u2019existence des r\ue9ponses h\ue9t\ue9rotiques pour ces traits. Les effets g\ue9niques additif et non-additif ont \ue9t\ue9 importants dans le contr\uf4le de ces caract\ue8res. K31.3, K37 et Ni331 pr\ue9sentent les meilleures aptitudes g\ue9n\ue9rales \ue0 la combinaison puis AVG-1 x K31.3 et AVG-1 x Tg148 ont \ue9t\ue9 les meilleurs hybrides pour le poids grains. Ils constituent une opportunit\ue9 pour l\u2019am\ue9lioration dans divers environnements. Les diff\ue9rentes m\ue9thodes ont class\ue9 les accessions de sorgho en quatre groupes. Le groupage bas\ue9 sur la m\ue9thode HSGCA accroit l\u2019efficience en s\ue9lection de 15 %. Cette \ue9tude offre un outil d\u2019aide pour les s\ue9lectionneurs dans le choix des meilleurs parents \ue0 croiser pour la production des hybrides sup\ue9rieurs en Afrique de l\u2019Ouest

    Gravitational corrections to Yukawa systems

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    We compute the gravitational corrections to the running of couplings in a scalar-fermion system, using the Wilsonian approach. Our discussion is relevant for symmetric as well as for broken scalar phases. We find that the Yukawa and quartic scalar couplings become irrelevant at the Gaussian fixed point.Comment: 5 pages, RevTex, discussion extended, typos corrected, reference added. Published online on PLB

    Investigating the effects of an oral fructose challenge on hepatic ATP reserves in healthy volunteers: a 31P MRS study

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    Background: Impaired homeostasis of hepatic ATP has been associated with NAFLD. An intravenous fructose infusion has been shown to be an effective challenge to monitor the depletion and subsequent recovery of hepatic ATP reserves using 31P MRS. Aims: The purpose of this study was to evaluate the effects of an oral rather than intravenous fructose challenge on hepatic ATP reserves in healthy subjects. Methods: Self-reported healthy males were recruited. Following an overnight fast, baseline liver glycogen and lipid levels were measured using Magnetic Resonance Spectroscopy (MRS). Immediately after consuming a 500 ml 75 g fructose drink (1275 kJ) subjects were scanned continuously for 90 min to acquire dynamic 31P MRS measurements of liver ATP reserves. Results: A significant effect on ATP reserves was observed across the time course (P < 0.05). Mean ATP levels reached a minimum at 50 min which was markedly lower than baseline (80 ± 17% baseline, P < 0.05). Subsequently, mean values tended to rise but did not reach statistical significance above minimum. The time to minimum ATP levels across subjects was negatively correlated with BMI (R2 ¼ 0.74, P < 0.005). Rates of ATP recovery were not significantly correlated with BMI or liver fat levels, but were negatively correlated with baseline glycogen levels (R2 ¼ 0.7, P < 0.05). Conclusions: Depletion of ATP reserves can be measured non-invasively following an oral fructose challenge using 31P
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