392 research outputs found

    Identification of mechanisms involved in mastitis response by means of gene network building.

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    Mastitis, an inflammation of the mammary gland, is the most prevalent and costly production disease in dairy herds worldwide. It is caused generally by bacteria and accounts for a significant decrease in milk production and quality. One promising approach to reduce problems caused by mastitis, in addition to sanitary care, is the selection of animals resistant to disease and the incorporation of this trait into the herds. Therefore, studies to better understand the mechanisms involved in animal response to this disease are essential to the proposition of new advances in area. In this context, the aim of this study was to identify groups of genes involved in cow response to mastitis infection, through gene network building from microarray data. Gene expression data from the GeneChipĂą Bovine Genome Array (Affymetrix) hybridization with milk somatic cells samples from Holstein-Zebu crossbreed dairy cows, obtained before (B) and 24 hrs after (A) artificial infection with Staphylococcus agalactiae, were analyzed using a network building methodology based on gene co-expression. We used WGCNA (Weighted Gene Co-expression Analysis), a systems biology method for describing the correlation patterns among genes across microarray samples, that can be used for finding clusters (modules) of highly correlated genes to identify modules of co-expressed genes, which may correspond to functionally related genes. By comparing two networks (between contrasting data sets), conserved and non-conserved modules can be identified. This strategy, named differential network analysis, aims to identify genes groups that are both differentially expressed and differentially connected, and changes in connectivity may correspond to large-scale rewiring, in response to environmental changes and/or physiologic perturbations. Two microarray data sets, B (n=5) and A (n=5), were preprocessed using affy and gcrma R/Bioconductor packages. A filter was applied, which resulted in the use of only those transcripts present in all samples. Gene co-expression networks were identified separately for each group (B and A), by the R/WGCNA package. Gene networks were compared between the two groups, and non-conserved modules were uncovered from a correlation test of the connectivity values. Our analysis identified a total of 17 modules of co-expressed genes, three of them, designed by the colors grey (n=35), blue (n=37) and turquoise (n=192), non-conserved between the groups. Using Blast2GO for enrichment analysis, we find the molecular function Protein Binding overrepresented in all three modules. However, in despite of the same molecular function, each one of the modules showed distinct characteristcs. Genes of grey module (BTG3, CD3E, MBD1, CHIC2, PLXNA3, MOCS3, NEIL1, VPS45, BCL2) were related to apoptosis and antigen recognition. Genes of turquoise module were enriched in inflammation mediators, including known mastitis marker genes (FGL1, GJA1, F2RL1, PTPRF, S100A2, TGFB2). The blue one uncovered genes involved in cell division and inflammatory response (CD97, MAD2L1, ZFP106, CDKN2C, LOC514364, NOP14, PCBD1, LOC100139798, AP1S1, EDN1, IL1B, ANXA11). Our study identified some mechanisms (represented by gene modules) that have changed in cows in early response to mastitis infection. Further analysis are being carried out, based on these results, to advance the understanding of animals response to the disease, which can lead to identify the candidate genes that could be used in breeding programs.X-MEETING 2011

    Men who were thin during early adulthood exhibited greater weight gain‐associated visceral fat accumulation in a study of middle‐aged Japanese men

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    ObjectiveThis study aimed to assess the relationship between weight gain from early adulthood and visceral fat accumulation.MethodsThe participants were 549 men aged 42 to 64 years who were randomly selected from the local resident registry for the National Institute for Longevity Sciences\u27 neighbourhood. They were asked to recall their weight at 18 years of age, and then, post‐18 weight‐change values were calculated for each participant (their current weight minus their weight at 18). The participants were divided according to their median body mass index (BMI) at 18 years of age (initial BMI) (<20.14 and ≄20.14 kg m−2). Visceral fat area (VFA) and subcutaneous fat area (SFA) were measured on computed tomography scans.ResultsThe participants with initial BMI of <20.14 kg m−2 exhibited greater post‐18 weight changes than those with initial BMI of ≄20.14 kg m−2. The participants\u27 post‐18 weight‐change values were negatively correlated with their initial BMI and positively correlated with both VFA and SFA. The slope of the regression line for the relationship between post‐18 weight change and VFA was steeper in the participants with initial BMI of <20.14 kg m−2 (ÎČ = 4.36) than in those with initial BMI of ≄20.14 kg m−2 (ÎČ = 3.23).ConclusionsVisceral fat accumulation is affected not only by an individual\u27s post‐18 weight gain but also by their initial BMI. Men who were thin in early adulthood experienced greater weight gain‐associated VFA increases, but the same was not true for SFA

    Consenting to health record linkage: evidence from a multi-purpose longitudinal survey of a general population

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    Background: The British Household Panel Survey (BHPS) is the first long-running UK longitudinal survey with a non-medical focus and a sample covering the whole age range to have asked for permission to link to a range of administrative health records. This study determines whether informed consent led to selection bias and reflects on the value of the BHPS linked with health records for epidemiological research. Methods. Multivariate logistical regression is used, with whether the respondent gave consent to data linkage or not as the dependent variable. Independent variables were entered as four blocks; (i) a set of standard demographics likely to be found in most health registration data, (ii) a broader set of socio-economic characteristics, (iii) a set of indicators of health conditions and (iv) information about the use of health services. Results: Participants aged 16-24, males and those living in England were more likely to consent. Consent is not biased with respect to socio-economic characteristics or health. Recent users of GP services are underrepresented among consenters. Conclusions: Whilst data could only be linked for a minority of BHPS participants, the BHPS offers a great range of information on people's life histories, their attitudes and behaviours making it an invaluable source for epidemiological research. © 2012 Knies et al; licensee BioMed Central Ltd

    A gene expression atlas of Vellozia nivea, a desiccation-tolerant species from the Brazilian campos rupestres.

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    Velloziaceae are an angiosperm family that contains the most desiccation-tolerant species (approximately 200 out of 270 species). More than 80% of the Velloziaceae species occur in South America, where the greatest morphological diversity is also found. The genus Vellozia comprises both desiccation-tolerant and non-desiccation-tolerant species, offering an excellent model for studying the evolution of desiccation- and drought-tolerance traits on plant genomes. To date, only limited genomic or transcript sequences are available for Velloziaceaespecies. Here we present a Vellozia nivea gene expression atlas across different plant organs and tissues, including flower, developing seeds, root, leaf, stem and seedling. Vellozia nivea is a desiccation-tolerant species, endemic to the Brazilian campos rupestres (rupestrian grasslands) and highly adapted to their extreme conditions. A total of 180.67 Gb of raw data were generated, and of these, 152.79 Gb were subjected to downstream analysis after quality control (QC). Vellozia niveade novotranscriptome assembly was performed with the Trinity bioinformatics tool, resulting in 684.615 contigs. After filtering contaminated sequence contigs from bacteria and fungi and removal of contigs with less than 10 sequence reads associated with the initial assembly, the transcriptome resulted in 195.512 remaining sequences. A GO enrichment analysis was performed on tissue&#8208;specific transcripts. The Vellozia nivea transcriptome should be a useful resource for genome annotation and gene function discovery studies.PE1028

    The Hyper Suprime-Cam SSP Survey: Overview and Survey Design

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    Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2m Subaru telescope on the summit of Maunakea in Hawaii. A team of scientists from Japan, Taiwan and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400 deg2^2 in five broad bands (grizygrizy), with a 5 σ5\,\sigma point-source depth of r≈26r \approx 26. The Deep layer covers a total of 26~deg2^2 in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter still in two pointings of HSC (a total of 3.5 deg2^2). Here we describe the instrument, the science goals of the survey, and the survey strategy and data processing. This paper serves as an introduction to a special issue of the Publications of the Astronomical Society of Japan, which includes a large number of technical and scientific papers describing results from the early phases of this survey.Comment: 14 pages, 7 figures, 5 tables. Corrected for a typo in the coordinates of HSC-Wide spring equatorial field in Table

    Cluster Lenses

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    Clusters of galaxies are the most recently assembled, massive, bound structures in the Universe. As predicted by General Relativity, given their masses, clusters strongly deform space-time in their vicinity. Clusters act as some of the most powerful gravitational lenses in the Universe. Light rays traversing through clusters from distant sources are hence deflected, and the resulting images of these distant objects therefore appear distorted and magnified. Lensing by clusters occurs in two regimes, each with unique observational signatures. The strong lensing regime is characterized by effects readily seen by eye, namely, the production of giant arcs, multiple-images, and arclets. The weak lensing regime is characterized by small deformations in the shapes of background galaxies only detectable statistically. Cluster lenses have been exploited successfully to address several important current questions in cosmology: (i) the study of the lens(es) - understanding cluster mass distributions and issues pertaining to cluster formation and evolution, as well as constraining the nature of dark matter; (ii) the study of the lensed objects - probing the properties of the background lensed galaxy population - which is statistically at higher redshifts and of lower intrinsic luminosity thus enabling the probing of galaxy formation at the earliest times right up to the Dark Ages; and (iii) the study of the geometry of the Universe - as the strength of lensing depends on the ratios of angular diameter distances between the lens, source and observer, lens deflections are sensitive to the value of cosmological parameters and offer a powerful geometric tool to probe Dark Energy. In this review, we present the basics of cluster lensing and provide a current status report of the field.Comment: About 120 pages - Published in Open Access at: http://www.springerlink.com/content/j183018170485723/ . arXiv admin note: text overlap with arXiv:astro-ph/0504478 and arXiv:1003.3674 by other author

    The "lipid accumulation product" performs better than the body mass index for recognizing cardiovascular risk: a population-based comparison

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    BACKGROUND: Body mass index (BMI, kg/m(2)) may not be the best marker for estimating the risk of obesity-related disease. Consistent with physiologic observations, an alternative index uses waist circumference (WC) and fasting triglycerides (TG) concentration to describe lipid overaccumulation. METHODS: The WC (estimated population minimum 65 cm for men and 58 cm for women) and TG concentration from the third National Health and Nutrition Examination Survey (N = 9,180, statistically weighted to represent 100.05 million US adults) were used to compute a "lipid accumulation product" [LAP = (WC-65) × TG for men and (WC-58) × TG for women] and to describe the population distribution of LAP. LAP and BMI were compared as categorical variables and as log-transformed continuous variables for their ability to identify adverse levels of 11 cardiovascular risk factors. RESULTS: Nearly half of the represented population was discordant for their quartile assignments to LAP and BMI. When 23.54 million with ordinal LAP quartile > BMI quartile were compared with 25.36 million with ordinal BMI quartile > LAP quartile (regression models adjusted for race-ethnicity and sex) the former had more adverse risk levels than the latter (p < 0.002) for seven lipid variables, uric acid concentration, heart rate, systolic and diastolic blood pressure. Further adjustment for age did not materially alter these comparisons except for blood pressures (p > 0.1). As continuous variables, LAP provided a consistently more adverse beta coefficient (slope) than BMI for nine cardiovascular risk variables (p < 0.01), but not for blood pressures (p > 0.2). CONCLUSION: LAP (describing lipid overaccumulation) performed better than BMI (describing weight overaccumulation) for identifying US adults at cardiovascular risk. Compared to BMI, LAP might better predict the incidence of cardiovascular disease, but this hypothesis needs prospective testing

    Structural, thermal and dissolution properties of MgO- and CaO-containing borophosphate glasses: effect of Fe2O3 addition

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    This paper investigated manufacture of high-durability phosphate glass fibres for biomedical applications. Five different borophosphate glass formulations in the systems of 45P2O5–5B2O3–5Na2O–(29 − x)CaO–16MgO–(x)Fe2O3 and 45P2O5–5B2O3–5Na2O–24CaO–(21 − x)MgO–(x)Fe2O3 where x = 5, 8 and 11 mol% were produced via melt quenching. The compositions and amorphous nature of the glasses were confirmed by ICP-MS and XRD, respectively. FTIR results indicated depolymerisation of the phosphate chains with a decrease in Q2 units with increasing Fe2O3 content. DSC analyses showed an increase in Tg by ~5 °C with an increment of 3 mol% in Fe2O3 content. The thermal properties were also used to calculate processing window (i.e. Tc,ons—Tg) and another parameter, Kgl, to determine the suitability for fibre drawing directly from melt, which equals (Tc,ons—Tg)/(Tl—Tc,ons). The degradation study conducted in PBS solution at 37 °C showed a decrease of 25–47% in degradation rate with increasing Fe2O3 content. This confirmed that the chemical durability of the glasses had increased, which was suggested to be due to Fe2O3 addition. Furthermore, the density measured via Archimedes method revealed a linear increase with increasing Fe2O3 content
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