966 research outputs found
Distance, Growth Factor, and Dark Energy Constraints from Photometric Baryon Acoustic Oscillation and Weak Lensing Measurements
Baryon acoustic oscillations (BAOs) and weak lensing (WL) are complementary
probes of cosmology. We explore the distance and growth factor measurements
from photometric BAO and WL techniques and investigate the roles of the
distance and growth factor in constraining dark energy. We find for WL that the
growth factor has a great impact on dark energy constraints but is much less
powerful than the distance. Dark energy constraints from WL are concentrated in
considerably fewer distance eigenmodes than those from BAO, with the largest
contributions from modes that are sensitive to the absolute distance. Both
techniques have some well determined distance eigenmodes that are not very
sensitive to the dark energy equation of state parameters w_0 and w_a,
suggesting that they can accommodate additional parameters for dark energy and
for the control of systematic uncertainties. A joint analysis of BAO and WL is
far more powerful than either technique alone, and the resulting constraints on
the distance and growth factor will be useful for distinguishing dark energy
and modified gravity models. The Large Synoptic Survey Telescope (LSST) will
yield both WL and angular BAO over a sample of several billion galaxies. Joint
LSST BAO and WL can yield 0.5% level precision on ten comoving distances evenly
spaced in log(1+z) between redshift 0.3 and 3 with cosmic microwave background
priors from Planck. In addition, since the angular diameter distance, which
directly affects the observables, is linked to the comoving distance solely by
the curvature radius in the Friedmann-Robertson-Walker metric solution, LSST
can achieve a pure metric constraint of 0.017 on the mean curvature parameter
Omega_k of the universe simultaneously with the constraints on the comoving
distances.Comment: 15 pages, 9 figures, details and references added, ApJ accepte
Restrictive ID policies: implications for health equity
We wish to thank Synod Community Services for their critical work to develop, support, and implement a local government-issued ID in Washtenaw County, MI. We also thank Yousef Rabhi of the Michigan House of Representatives and Janelle Fa'aola of the Washtenaw ID Task Force, Lawrence Kestenbaum of the Washtenaw County Clerk's Office, Sherriff Jerry Clayton of the Washtenaw County Sherriff's Office, and the Washtenaw ID Task Force for their tireless commitment to developing and supporting the successful implementation of the Washtenaw ID. Additionally, we thank Vicenta Vargas and Skye Hillier for their contributions to the Washtenaw ID evaluation. We thank the Curtis Center for Research and Evaluation at the University of Michigan School of Social Work, the National Center for Institutional Diversity at the University of Michigan, and the University of California-Irvine Department of Chicano/Latino Studies and Program in Public Health for their support of the Washtenaw ID community-academic research partnership. Finally, we thank the reviewers for their helpful comments on earlier drafts of this manuscript. (Curtis Center for Research and Evaluation at the University of Michigan School of Social Work; National Center for Institutional Diversity at the University of Michigan; University of California-Irvine Department of Chicano/Latino Studies; Program in Public Health)https://link.springer.com/content/pdf/10.1007/s10903-017-0579-3.pdfPublished versio
Lateral opening in the intact ÎČ-barrel assembly machinery captured by cryo-EM
The ÎČ-barrel assembly machinery (BAM) is a ~203 kDa complex of five proteins (BamA-E) which is essential for viability in E. coli. BAM promotes the folding and insertion of ÎČ-barrel proteins into the outer membrane via a poorly understood mechanism. Several current models suggest that BAM functions through a âlateral gatingâ motion of the ÎČ-barrel of BamA. Here we present a cryo-EM structure of the BamABCDE complex, at 4.9 Ă
resolution. The structure is in a laterally open conformation showing that gating is independent of BamB binding. We describe conformational changes throughout the complex, and interactions between BamA, B, D, and E and the detergent micelle that suggest communication between BAM and the lipid bilayer. Finally, using an enhanced reconstitution protocol and functional assays, we show that for the outer membrane protein OmpT, efficient folding in vitro requires lateral gating in BAM
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Sexualized drug use ("chemsex') and high-risk sexual behaviours in HIV-positive men who have sex with men
Objectives
The incidence of sexually transmitted infections (STI s) and HIV infection remains high in gay, bisexual, and other men who have sex with men (MSM ) in the UK , and sexualized drug use (âchemsexâ) and injecting drug use (âslamsexâ) may play a part in this. We aimed to characterize HIV âpositive MSM engaging in chemsex/slamsex and to assess the associations with selfâreported STI diagnoses and sexual behaviours.
Methods
Data from a 2014 survey of people attending HIV clinics in England and Wales were linked to clinical data from national HIV surveillance records and weighted to be nationally representative. Multivariable logistic regression assessed the associations of chemsex and slamsex with selfâreported unprotected anal intercourse (UAI ), serodiscordant UAI (sdUAI ) (i.e. UAI with an HIV ânegative or unknown HIV status partner), sdUAI with a detectable viral load (>50 HIV â1 RNA copies/mL ), hepatitis C, and bacterial STI s.
Results
In the previous year, 29.5% of 392 sexually active participants engaged in chemsex, and 10.1% in slamsex. Chemsex was significantly associated with increased odds of UAI [adjusted odds ratio (AOR ) 5.73; P < 0.001], sdUAI (AOR 2.34; P < 0.05), sdUAI with a detectable viral load (AOR 3.86; P < 0.01), hepatitis C (AOR 6.58; P < 0.01), and bacterial STI diagnosis (AOR 2.65; P < 0.01). Slamsex was associated with increased odds of UAI (AOR 6.11; P < 0.05), hepatitis C (AOR 9.39; P < 0.001), and bacterial STI diagnosis (AOR 6.11; P < 0.001).
Conclusions
Three in ten sexually active HIV âpositive MSM engaged in chemsex in the past year, which was positively associated with selfâreported depression/anxiety, smoking, nonsexual drug use, risky sexual behaviours, STI s, and hepatitis C. Chemsex may therefore play a role in the ongoing HIV and STI epidemics in the UK
Prevalence and Factors Associated with Hygiene Behaviours among In-School Adolescents in Ghana
(1) Background: Despite a global call to act to resolve communicable diseases caused by lack of clean water, sanitation, and hygiene, many people in low- and middle-income countries continue to die each year. In this study, we looked at in-school adolescentsâ oral and hand hygiene activities in Ghana, as well as the factors that influence them. (2) Methods: This was a cross-sectional study that utilised data on 1348 in-school adolescents from the 2012 global school-based health survey. Using Stata software version 14.2, descriptive and inferential statistics were used to analyze the data. All statistical analyses were considered significant at p-value < 0.05. (3) Results: The prevalence of good hygiene behaviour was 62.6% and 79.9% for good oral hygiene and good hand hygiene, respectively. In-school adolescents who were truant were 31% (AOR = 0.69, 95% CI = 0.51â0.92) and 28% (AOR = 0.72, 95% CI = 0.54â0.87), respectively, less likely to practise good hand and oral hygiene compared to those who were not. Adolescents whose parents supervised their homework, however, had higher probabilities of practising good hand (AOR = 2.30, 95% CI = 1.64â2.31) and oral (AOR = 2.34, 95% CI = 1.80â3.04) hygiene respectively. Adolescents aged 18 years and above were 1.33 times more likely to practice good oral hygiene than younger adolescents (AOR=1.33, 95% CI = 1.07â1.66). Adolescents who were bullied had lower odds of practicing good hand hygiene (AOR = 0.70, 95% CI = 0.52â0.94). (4) Conclusions: While good hygiene behaviour remains a major strategy in decreasing the prevalence of communicable diseases, the less than 65% prevalence of hand hygiene we observed in the current study is indicative of the countryâs inability to achieve water, hygiene and sanitation for all by the year 2030. To accelerate progress towards meeting the Sustainable Development Goal 6.2, there is a need for the implementation of innovative interventions which seek to promote good hygiene behaviours among adolescents and the expansion of existing interventions, such as the WASH initiative, in schools. Such interventions should focus more on younger adolescents, those who are truant, and adolescents who suffer from bullying in school.</jats:p
Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine
In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown
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