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

Catastrophic photometric redshift errors: weak lensing survey requirements

We study the sensitivity of weak lensing surveys to the effects of catastrophic redshift errors - cases where the true redshift is misestimated by a significant amount. To compute the biases in cosmological parameters, we adopt an efficient linearized analysis where the redshift errors are directly related to shifts in the weak lensing convergence power spectra. We estimate the number Nspec of unbiased spectroscopic redshifts needed to determine the catastrophic error rate well enough that biases in cosmological parameters are below statistical errors of weak lensing tomography. While the straightforward estimate of Nspec is ~10^6 we find that using only the photometric redshifts with z<=2.5 leads to a drastic reduction in Nspec to ~30,000 while negligibly increasing statistical errors in dark energy parameters. Therefore, the size of spectroscopic survey needed to control catastrophic errors is similar to that previously deemed necessary to constrain the core of the z_s-z_p distribution. We also study the efficacy of the recent proposal to measure redshift errors by cross-correlation between the photo-z and spectroscopic samples. We find that this method requires ~10% a priori knowledge of the bias and stochasticity of the outlier population, and is also easily confounded by lensing magnification bias. The cross-correlation method is therefore unlikely to supplant the need for a complete spectroscopic redshift survey of the source population.Comment: 14 pages, 3 figure

Gut epithelial electrical cues drive differential localization of enterobacteria

Salmonella translocate to the gut epithelium via microfold cells lining the follicle-associated epithelium (FAE). How Salmonella localize to the FAE is not well characterized. Here we use live imaging and competitive assays between wild-type and chemotaxis-deficient mutants to show that Salmonella enterica serotype Typhimurium (S. Typhimurium) localize to the FAE independently of chemotaxis in an ex vivo mouse caecum infection model. Electrical recordings revealed polarized FAE with sustained outward current and small transepithelial potential, while the surrounding villus is depolarized with inward current and large transepithelial potential. The distinct electrical potentials attracted S. Typhimurium to the FAE while Escherichia coli (E. coli) localized to the villi, through a process called galvanotaxis. Chloride flux involving the cystic fibrosis transmembrane conductance regulator (CFTR) generated the ionic currents around the FAE. Pharmacological inhibition of CFTR decreased S. Typhimurium FAE localization but increased E. coli recruitment. Altogether, our findings demonstrate that bioelectric cues contribute to S. Typhimurium targeting of specific gut epithelial locations, with potential implications for other enteric bacterial infections

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

Assessment of Food Safety Knowledge, Attitudes and Practices of Food Service Staff in Bangladeshi Hospitals: A Cross-Sectional Study.

Food safety knowledge, attitudes and practices among hospital food service staff are crucial in the prevention of foodborne disease outbreaks, as hospitalized patients are more vulnerable to potential hazards. This study, therefore, sought to assess the food safety knowledge, attitudes and practices of food service staff in Bangladeshi hospitals. A cross-sectional study was conducted among 191 food service staff from seven different hospitals in Dhaka and Chattogram from October 2021 to March 2022 using pretested questionnaires. Multiple linear regression was used to identify the factors associated with the food safety knowledge, attitudes and practices. The findings showed moderate knowledge but high levels of attitudes and practices of food safety among hospital food handlers. Food safety knowledge was significantly higher among males, participants from private hospitals and participants working in a hospital that had a food service supervisor and dietitian in charge of food service operations. Moreover, participants from private hospitals and participants working in a hospital that had a food service supervisor and dietitian in charge of food service operations had more positive attitudes and better practices regarding food safety. Hospital management should consider these factors for enhancing food handlers' knowledge and increase training and supervision on food safety practices to reduce foodborne diseases and outbreaks

Lateral opening in the intact β-barrel assembly machinery captured by cryo-EM

The β-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 β-barrel proteins into the outer membrane via a poorly understood mechanism. Several current models suggest that BAM functions through a ‘lateral gating’ motion of the β-barrel of BamA. Here we present a cryo-EM structure of the BamABCDE complex, at 4.9 Å 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

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 (“chemsex”) and injecting drug use (“slamsex”) may play a part in this. We aimed to characterize HIV ‐positive MSM engaging in chemsex/slamsex and to assess the associations with self‐reported 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 self‐reported unprotected anal intercourse (UAI ), serodiscordant UAI (sdUAI ) (i.e. UAI with an HIV ‐negative or unknown HIV status partner), sdUAI with a detectable viral load (>50 HIV ‐1 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 ‐positive MSM engaged in chemsex in the past year, which was positively associated with self‐reported 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 adolescents’ 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 &lt; 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 = 0.51–0.92) and 28% (AOR = 0.72, 95% CI = 0.54–0.87), 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 = 1.64–2.31) and oral (AOR = 2.34, 95% CI = 1.80–3.04) 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 = 1.07–1.66). Adolescents who were bullied had lower odds of practicing good hand hygiene (AOR = 0.70, 95% CI = 0.52–0.94). (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 country’s 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