Does solar irradiation drive community assembly of vulture plumage microbiotas?

Abstract Background Stereotyped sunning behaviour in birds has been hypothesized to inhibit keratin-degrading bacteria but there is little evidence that solar irradiation affects community assembly and abundance of plumage microbiota. The monophyletic New World vultures (Cathartiformes) are renowned for scavenging vertebrate carrion, spread-wing sunning at roosts, and thermal soaring. Few avian species experience greater exposure to solar irradiation. We used 16S rRNA sequencing to investigate the plumage microbiota of wild individuals of five sympatric species of vultures in Guyana. Results The exceptionally diverse plumage microbiotas (631 genera of Bacteria and Archaea) were numerically dominated by bacterial genera resistant to ultraviolet (UV) light, desiccation, and high ambient temperatures, and genera known for forming desiccation-resistant endospores (phylum Firmicutes, order Clostridiales). The extremophile genera Deinococcus (phylum Deinococcus-Thermus) and Hymenobacter (phylum, Bacteroidetes), rare in vertebrate gut microbiotas, accounted for 9.1% of 2.7 million sequences (CSS normalized and log2 transformed). Five bacterial genera known to exhibit strong keratinolytic capacities in vitro (Bacillus, Enterococcus, Pseudomonas, Staphylococcus, and Streptomyces) were less abundant (totaling 4%) in vulture plumage. Conclusions Bacterial rank-abundance profiles from melanized vulture plumage have no known analog in the integumentary systems of terrestrial vertebrates. The prominence of UV-resistant extremophiles suggests that solar irradiation may play a significant role in the assembly of vulture plumage microbiotas. Our results highlight the need for controlled in vivo experiments to test the effects of UV on microbial communities of avian plumage

Impact of an addiction medicine consult service on patients admitted to the hospital with injection drug use-associated infective endocarditis

Background: The addition of an addiction medicine consult service has been shown to improve mortality and decrease hospital costs but its impact on the proportion of patients discharged against medical advice (DAMA) and in-hospital initiation of medication for opioid use disorder (MOUD) has not been examined. Methods: A retrospective before-after cohort study was performed at an urban, academic medical center between January 1, 2015 and November 1, 2019. We included adult patients with infective endocarditis and injection drug use determined by admitting diagnosis ICD-9 or ICD-10 codes or documentation within the history section of electronic health recordEHR. Our institution implemented a formal addiction medicine consult service on July 1, 2018. We determined the proportion of patients DAMA and the proportion of patients started on MOUD among patients in the pre-intervention (i.e. hospitalized before July 1, 2018) and intervention (i.e. hospitalized July 1, 2018 or after) groups. Results: A total of 171 patients among hospitalized patients with injection drug use-associated infective endocarditis were included with 119 patients in the pre-intervention group and 52 patients in the intervention group. There was no statistically significant difference in patients DAMA [19% vs 15%, absolute risk difference 4.6% (95% confidence interval -8.6% to 17.7%)] between the intervention and pre-intervention groups. However, there was an increase in the proportion of inpatient MOUD initiation in the intervention group compared to the pre-intervention group [56% vs 21%, absolute risk difference 35% (95% confidence interval 19% to 50%)]. Conclusions: The initiation of an addiction medicine consult service was associated with a higher proportion of MOUD initiation but there was no statistically significant association with the proportion of patients DAMA

Development of electrochromic cells by the sol-gel process

These investigations have the development of electrochromic cells via the sol-gel process as their objective. Syntheses routes for tungsten oxide, WO3, coating sols and cerium oxide-titanium oxide sols, CeO2-TiO2, were developed, which enabled indium-tin oxide (ITO) coated glass substrates to be coated homogeneously and without visible cracking. Optoelectrochemical measurements were employed to determine the variation of the electrochromic properties (change in optical density, ΔOD, and switching times) of WO3 layers, investigated as a function of coating parameters, such as chamber humidity and the temperature of heat treatment. A novel nanocomposite electrolyte system, based on organically modified silanes, was developed, which has an ionic conductivity of 10-4-10-5 S cm-1 at 25°C. Values of diffusion coefficients for lithium ions in tungsten oxide layers could be determined by electrochemical impedance spectroscopy (EIS) and lie in the range 10-11-10-12 cm2/s. The values obtained are comparable with literature values for WO3 layers deposited by sputtering. The cells which have been constructed to date show a typical reduction in transmission from 80% to 20% with a half-life of less than 30 s, where half-life is here defined as the time necessary for half of the change in transmission to be obtained, i.e. from 80% to 50%

Constraints on Type Ib/c and GRB Progenitors

Although there is strong support for the collapsar engine as the power source of long-duration gamma-ray bursts (GRBs), we still do not definitively know the progenitor of these explosions. Here we review the current set of progenitor scenarios for long-duration GRBs and the observational constraints on these scenarios. Examining these, we find that single-star models cannot be the only progenitor for long-duration GRBs. Several binary progenitors can match the solid observational constraints and also have the potential to match the trends we are currently seeing in the observations. Type Ib/c supernovae are also likely to be produced primarily in binaries; we discuss the relationship between the progenitors of these explosions and those of the long-duration GRBs.Comment: 36 pages, 6 figure