118 research outputs found
Age and Abundance Discrimination in Old Stellar Populations Using Mid-Ultraviolet Colors
The restframe mid-ultraviolet spectral region (2000-3200 A) is important in
analyzing the stellar populations of the "red envelope" systems observed at
high redshifts. Here, we explore the usefulness of the mid-UV for determining
ages and abundances of old populations. A mid-UV to optical/IR wavelength
baseline provides good separation of population components because the main
sequence turnoff dominates the integrated light between 2500 and 4000 A. We
find a six magnitude difference in the mid-UV continuum level over the
metallicity range -1.5 < log Z/Z_o < +0.5 and a comparable difference (per unit
log t) for ages in the range 4-16 Gyr. Logarithmic derivatives of mid-UV colors
with respect to age or metal abundance are 3-10 times larger than for the UBV
region. Most of the spectral information on old populations therefore resides
below 4000 A. We investigate the capability of UBV and mid-UV broad-band colors
to separately determine age and abundance, taking into account precision in the
color measurements. We find that the mid-UV improves resolution in (log t,log
Z) space by about a factor of 3 for a given observational precision.
Contamination by hot horizontal branch phases can seriously affect mid-UV
spectra, reaching over 80% in some cases. However, this is straightforward to
remove as long as far-UV measurements are available. Finally, we show that a 4
Gyr, solar abundance model based on empirical spectra provides an excellent fit
to the mid-UV spectrum of the E galaxy M32. This indicates that the poorer
results obtained from theoretical spectra arise from limitations of the
synthesis models for individual stars. [Condensed]Comment: 38 pages, 8 figures. Accepted by ApJ. Full resolution figures
available at: http://www.astro.virginia.edu/~rwo/miduv-fullresfigs.ps.g
Evaluation of LOXL1 gene polymorphisms in exfoliation syndrome and exfoliation glaucoma
Purpose: To evaluate genetic susceptibility of lysyl oxidase-like 1 (LOXL1) gene polymorphisms to exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) in a case-control cohort of American and European patients.
Methods: DNA from a total of 620 individuals including 287 exfoliation patients and 333 healthy control subjects were
extracted by standard methods. Three single nucleotide polymorphisms (SNPs) of rs1048661 (R141L), rs3825942
(G153D), and rs2165241 were genotyped in these individuals by SNaPshot Assay. The seven coding exons of the LOXL1 gene and their immediate flanking regions were directly sequenced in 95 affected patients. Data management and
case-control association studies were performed with SNP-STAT and PLINK programs. The obtained DNA sequences
were evaluated with the STADEN package.
Results: The 287 unrelated exfoliation cases comprised of 171 American patients (mostly of European background) and
116 patients from 12 European countries. This phenotype was further divided into patients with exfoliation only and no
glaucoma (XFO; n=95), exfoliation with glaucoma (XFG; n=133), and exfoliation unclassified (XFU; n=59). Genotypic
data were analyzed separately for XFO, XFG, XFU, and XFS (all exfoliations; n=287) and for Americans and Europeans.
The observed genotypic frequencies for each exfoliation phenotype or population were tabulated separately and tested for deviation from the HardyâWeinberg equilibrium (HWE) using a standard Χ2 test. There were no HWE deviations and no significant genotypic differences between these subcategories for the three studied SNPs. For the combined exfoliation cohort, homozygote genotypes of G/G (rs1048661), G/G (rs3825942), and T/T (rs2165241) were significantly overrepresented. Likewise, case-control allelic association for rs1048661 (p=7.74x10â9), rs3825942 (p=3.10x10â17), and rs2165241 (p=4.85x10â24) were highly significant. The corresponding two-locus haplotype frequencies of GG for rs1048661-rs3825942 (p=1.47x10â27), GT for rs1048661-rs2165241 (p=1.29x10â24), and GT for rs3825942-rs2165241 (p=2.02x10â24) were highly associated with exfoliation phenotypes. The combined effect of these three SNPs revealed that the GGT haplotype is overrepresented by 66% in exfoliation cases, and this deviation from controls is highly significant
(p=1.93x10â24). This haplotype constituted a major risk factor for development of exfoliation in both XFS and XFG. By contrast, the GAC haplotype was significantly underrepresented (p=4.99x10â18) in exfoliation cases by 83% and may potentially have a protective effect for this condition with an estimated attributable risk percent reduction of 457%. The only other haplotype that was significantly different between cases and controls was TGC (p=5.82x10â9). No observation was made for the GAT haplotype. The combined three haplotypes of GGT, GAC, and TGC were associated with 91% of the exfoliation syndrome cases in the studied populations. Seven coding exons of LOXL1 were also sequenced in 95 affected cases. In addition to the three above-mentioned SNPs, 12 other variations were also observed in these patients(G240G, D292D, A320A, V385V, rs2304719, IVS3+23C>T, IVS3â155G>A, IVS3â101G>A, IVS4+49G>A,
rs2304721, IVS5â121C>T, and rs2304722). None were considered a disease-causing mutation.
Conclusions: We confirmed a strong association with LOXL1 variants in our patients. For the LOXL1 gene, individual
alleles of rs1048661 (G), rs3825942 (G), and rs2165241 (T) are highly associated with XFS and XFG in American and
European populations. The GGT haplotype constitutes a major risk haplotype for exfoliation, and GAC may have a
protective role. DNA sequencing of 95 affected patients did not show any mutations in this gene. The LOXL1 SNPs are
located in the 15q24.1 band and within a genetic locus (GLC1N) that is associated with primary open-angle glaucoma
(POAG). However, the LOXL1 genetic predisposition is only limited to exfoliation with or without glaucoma and does
not include the POAG phenotype
International society of sports nutrition position stand: diets and body composition
Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature regarding the effects of diet types (macronutrient composition; eating styles) and their influence on body composition. The ISSN has concluded the following. 1) There is a multitude of diet types and eating styles, whereby numerous subtypes fall under each major dietary archetype. 2) All body composition assessment methods have strengths and limitations. 3) Diets primarily focused on fat loss are driven by a sustained caloric deficit. The higher the baseline body fat level, the more aggressively the caloric deficit may be imposed. Slower rates of weight loss can better preserve lean mass (LM) in leaner subjects. 4) Diets focused primarily on accruing LM are driven by a sustained caloric surplus to facilitate anabolic processes and support increasing resistance-training demands. The composition and magnitude of the surplus, as well as training status of the subjects can influence the nature of the gains. 5) A wide range of dietary approaches (low-fat to low-carbohydrate/ketogenic, and all points between) can be similarly effective for improving body composition. 6) Increasing dietary protein to levels significantly beyond current recommendations for athletic populations may result in improved body composition. Higher protein intakes (2.3â3.1 g/ kg FFM) may be required to maximize muscle retention in lean, resistance-trained subjects under hypocaloric conditions. Emerging research on very high protein intakes (\u3e3 g/kg) has demonstrated that the known thermic, satiating, and LM-preserving effects of dietary protein might be amplified in resistance-training subjects. 7) The collective body of intermittent caloric restriction research demonstrates no significant advantage over daily caloric restriction for improving body composition. 8) The long-term success of a diet depends upon compliance and suppression or circumvention of mitigating factors such as adaptive thermogenesis. 9) There is a paucity of research on women and older populations, as well as a wide range of untapped permutations of feeding frequency and macronutrient distribution at various energetic balances combined with training. Behavioral and lifestyle modification strategies are still poorly researched areas of weight management
A systematic review, meta-analysis and metaregression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults
Objective We performed a systematic review, metaanalysis and meta-regression to determine if dietary protein supplementation augments resistance exercise training (RET)-induced gains in muscle mass and strength.
Data sources A systematic search of Medline, Embase, CINAHL and SportDiscus.
Eligibility criteria Only randomised controlled trials with RET â„6 weeks in duration and dietary protein supplementation.
Design Random-effects meta-analyses and metaregressions with four a priori determined covariates. Twophase break point analysis was used to determine the relationship between total protein intake and changes in fat-free mass (FFM).
ResultsData from 49 studies with 1863 participants showed that dietary protein supplementation significantly (all p
Summary/conclusion Dietary protein supplementation significantly enhanced changes in muscle strength and size during prolonged RET in healthy adults. Increasing age reduces and training experience increases the efficacy of protein supplementation during RET. With protein supplementation, protein intakes at amounts greater than ~1.6 g/kg/day do not further contribute RET-induced gains in FFM
Antischistosomal Activity of Trioxaquines: In Vivo Efficacy and Mechanism of Action on Schistosoma mansoni
Schistosomiasis is among the most neglected tropical diseases, since its mode of spreading tends to limit the contamination to people who are in contact with contaminated waters in endemic countries. Here we report the in vitro and in vivo anti-schistosomal activities of trioxaquines. These hybrid molecules are highly active on the larval forms of the worms and exhibit different modes of action, not only the alkylation of heme. The synergy observed with praziquantel on infected mice is in favor of the development of these trioxaquines as potential anti-schistosomal agents
The emergence and diversification of a zoonotic pathogen from within the microbiota of intensively farmed pigs
The expansion and intensification of livestock production is predicted to promote the emergence of pathogens. As pathogens sometimes jump between species, this can affect the health of humans as well as livestock. Here, we investigate how livestock microbiota can act as a source of these emerging pathogens through analysis of Streptococcus suis, a ubiquitous component of the respiratory microbiota of pigs that is also a major cause of disease on pig farms and an important zoonotic pathogen. Combining molecular dating, phylogeography, and comparative genomic analyses of a large collection of isolates, we find that several pathogenic lineages of S. suis emerged in the 19th and 20th centuries, during an early period of growth in pig farming. These lineages have since spread between countries and continents, mirroring trade in live pigs. They are distinguished by the presence of three genomic islands with putative roles in metabolism and cell adhesion, and an ongoing reduction in genome size, which may reflect their recent shift to a more pathogenic ecology. Reconstructions of the evolutionary histories of these islands reveal constraints on pathogen emergence that could inform control strategies, with pathogenic lineages consistently emerging from one subpopulation of S. suis and acquiring genes through horizontal transfer from other pathogenic lineages. These results shed light on the capacity of the microbiota to rapidly evolve to exploit changes in their host population and suggest that the impact of changes in farming on the pathogenicity and zoonotic potential of S. suis is yet to be fully realized
Spectrum and Inoculum Size Effect of a Rapid Antigen Detection Test for Group A Streptococcus in Children with Pharyngitis
BACKGROUND: The stability of the accuracy of a diagnostic test is critical to whether clinicians can rely on its result. We aimed to assess whether the performance of a rapid antigen detection test (RADT) for group A streptococcus (GAS) is affected by the clinical spectrum and/or bacterial inoculum size. METHODS: Throat swabs were collected from 785 children with pharyngitis in an office-based, prospective, multicenter study (2009-2010). We analysed the effect of clinical spectrum (i.e., the McIsaac score and its components) and inoculum size (light or heavy GAS growth) on the accuracy (sensitivity, specificity, likelihood ratios and predictive values) of a RADT, with laboratory throat culture as the reference test. We also evaluated the accuracy of a McIsaac-score-based decision rule. RESULTS: GAS prevalence was 36% (95CI: 33%-40%). The inoculum was heavy for 85% of cases (81%-89%). We found a significant spectrum effect on sensitivity, specificity, likelihood ratios and positive predictive value (p<0.05) but not negative predictive value, which was stable at about 92%. RADT sensitivity was greater for children with heavy than light inoculum (95% vs. 40%, p<0.001). After stratification by inoculum size, the spectrum effect on RADT sensitivity was significant only in patients with light inoculum, on univariate and multivariate analysis. The McIsaac-score-based decision rule had 99% (97%-100%) sensitivity and 52% (48%-57%) specificity. CONCLUSIONS: Variations in RADT sensitivity only occur in patients with light inocula. Because the spectrum effect does not affect the negative predictive value of the test, clinicians who want to rule out GAS can rely on negative RADT results regardless of clinical features if they accept that about 10% of children with negative RADT results will have a positive throat culture. However, such a policy is more acceptable in populations with very low incidence of complications of GAS infection
The emergence and diversification of a zoonotic pathogen from within the microbiota of intensively farmed pigs
The expansion and intensification of livestock production is predicted to promote the
emergence of pathogens. As pathogens sometimes jump between species, this can affect
the health of humans as well as livestock. Here, we investigate how livestock microbiota
can act as a source of these emerging pathogens through analysis of Streptococcus suis, a
ubiquitous component of the respiratory microbiota of pigs that is also a major cause of
disease on pig farms and an important zoonotic pathogen. Combining molecular dating,
phylogeography, and comparative genomic analyses of a large collection of isolates, we
find that several pathogenic lineages of S. suis emerged in the 19th and 20th centuries,
during an early period of growth in pig farming. These lineages have since spread between
countries and continents, mirroring trade in live pigs. They are distinguished by the
presence of three genomic islands with putative roles in metabolism and cell adhesion,
and an ongoing reduction in genome size, which may reflect their recent shift to a more
pathogenic ecology. Reconstructions of the evolutionary histories of these islands reveal
constraints on pathogen emergence that could inform control strategies, with pathogenic lineages consistently emerging from one subpopulation of S. suis and acquiring
genes through horizontal transfer from other pathogenic lineages. These results shed
light on the capacity of the microbiota to rapidly evolve to exploit changes in their host
population and suggest that the impact of changes in farming on the pathogenicity and
zoonotic potential of S. suis is yet to be fully realized.This work was primarily funded by an EU Horizon 2020 grant âPIGSsâ (727966) and a ZELS BBSRC award âMyanmar Pigs Partnership (MPP)â (BB/L018934/1). G.G.R.M., E.L.M., and L.A.W. were supported by a Sir Henry Dale Fellowship to L.A.W. jointly funded by the Wellcome Trust and the Royal Society (109385/Z/15/Z). N.H. was supported by a Challenge grant from the Royal Society (CH16011) and an Isaac Newton Trust Research Grant [17.24(u)]. G.G.R.M. was also supported by a Research Fellowship at Newnham College. S.B. is supported by the Medical Research Council (MR/V032836/1). PIC North America provided part of the funds for the sequencing of the isolates from the USA. A.J.B. and M.M. were funded by Medical Research Council and Biotechnology and Biological Sciences Research Council studentships respectively, and M.M. was co-funded by the Raymond and Beverly Sackler Fund. We would like to acknowledge Susanna Williamson at the APHA for providing samples, Oscar CabezĂłn for sampling of the wild boar population in Spain, Mark OâDea for access to sequence data from Australian isolates, the PIGSs and MPP consortiums for providing samples and helpful discussions, Julian Parkhill and John Welch for helpful discussions, and two anonymous reviewers for their valuable suggestions for improving the manuscript. This research was funded in whole or in part by the Wellcome Trust. For the purpose of Open Access, the author has applied a CC BY public copyright license to any Author Accepted Manuscript (AAM) version arising from this submission.info:eu-repo/semantics/publishedVersio
International society of sports nutrition position stand: diets and body composition
Abstract Position Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature regarding the effects of diet types (macronutrient composition; eating styles) and their influence on body composition. The ISSN has concluded the following. 1) There is a multitude of diet types and eating styles, whereby numerous subtypes fall under each major dietary archetype. 2) All body composition assessment methods have strengths and limitations. 3) Diets primarily focused on fat loss are driven by a sustained caloric deficit. The higher the baseline body fat level, the more aggressively the caloric deficit may be imposed. Slower rates of weight loss can better preserve lean mass (LM) in leaner subjects. 4) Diets focused primarily on accruing LM are driven by a sustained caloric surplus to facilitate anabolic processes and support increasing resistance-training demands. The composition and magnitude of the surplus, as well as training status of the subjects can influence the nature of the gains. 5) A wide range of dietary approaches (low-fat to low-carbohydrate/ketogenic, and all points between) can be similarly effective for improving body composition. 6) Increasing dietary protein to levels significantly beyond current recommendations for athletic populations may result in improved body composition. Higher protein intakes (2.3â3.1Â g/kg FFM) may be required to maximize muscle retention in lean, resistance-trained subjects under hypocaloric conditions. Emerging research on very high protein intakes (>3Â g/kg) has demonstrated that the known thermic, satiating, and LM-preserving effects of dietary protein might be amplified in resistance-training subjects. 7) The collective body of intermittent caloric restriction research demonstrates no significant advantage over daily caloric restriction for improving body composition. 8) The long-term success of a diet depends upon compliance and suppression or circumvention of mitigating factors such as adaptive thermogenesis. 9) There is a paucity of research on women and older populations, as well as a wide range of untapped permutations of feeding frequency and macronutrient distribution at various energetic balances combined with training. Behavioral and lifestyle modification strategies are still poorly researched areas of weight management
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in
operation since July 2014. This paper describes the second data release from
this phase, and the fourteenth from SDSS overall (making this, Data Release
Fourteen or DR14). This release makes public data taken by SDSS-IV in its first
two years of operation (July 2014-2016). Like all previous SDSS releases, DR14
is cumulative, including the most recent reductions and calibrations of all
data taken by SDSS since the first phase began operations in 2000. New in DR14
is the first public release of data from the extended Baryon Oscillation
Spectroscopic Survey (eBOSS); the first data from the second phase of the
Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2),
including stellar parameter estimates from an innovative data driven machine
learning algorithm known as "The Cannon"; and almost twice as many data cubes
from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous
release (N = 2812 in total). This paper describes the location and format of
the publicly available data from SDSS-IV surveys. We provide references to the
important technical papers describing how these data have been taken (both
targeting and observation details) and processed for scientific use. The SDSS
website (www.sdss.org) has been updated for this release, and provides links to
data downloads, as well as tutorials and examples of data use. SDSS-IV is
planning to continue to collect astronomical data until 2020, and will be
followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14
happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov
2017 (this is the "post-print" and "post-proofs" version; minor corrections
only from v1, and most of errors found in proofs corrected
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