Detection of local-scale population declines through optimized tidal marsh bird monitoring design

Evaluating the efficacy of monitoring designs is crucial for the successful monitoring and conservation of populations. For tidal marsh bird species of conservation concern, detecting population declines at local spatial scales within actionable time frames is a top priority. We examined and compared the effectiveness of alternative monitoring strategies for detecting local-scale population declines using count data from 1176 spatially-independent salt marsh sampling points throughout the northeastern United States (Maine to Virginia). We used abundance estimates that accounted for imperfect detection as initial conditions to simulate annual population declines of 5%, 10%, 30%, and 50% over a 5-year sampling period. Under an optimal monitoring design with biennial sampling, we were able to successfully detect annual population declines of ≥30% for each species and for all species combined. However, this required a minimum of 15–20 points per site being sampled. Power to detect declines, although low for detecting smaller annual declines (i.e., \u3c10%), improved substantially when points were visited twice per season, yet a third visit provided a reduced benefit. When testing factors that could potentially influence power to detect declines, we found that the power within sites was positively related to species abundance. Power was similar between biennial sampling (3 of 5 years) and annual sampling (5 of 5 years), suggesting a more cost-effective approach would be to sample every other year. We found that within most sites, detecting annual declines of 10% or less over a relatively short 5-year duration would be difficult. Hence, we recommend that salt marsh bird monitoring programs in the northeastern United States conduct two visits to each site per sampling year, include 15 or more sampling points per site (without confounding spatial independence), and conduct monitoring efforts every other year. This approach will maximize the efficacy of site-level monitoring of tidal marsh birds, which can aid in assessments of coastal wetland conservation and related habitat management efforts

Glycosaminoglycans and Sialylated Glycans Sequentially Facilitate Merkel Cell Polyomavirus Infectious Entry

Merkel cell polyomavirus (MCV or MCPyV) appears to be a causal factor in the development of Merkel cell carcinoma, a rare but highly lethal form of skin cancer. Although recent reports indicate that MCV virions are commonly shed from apparently healthy human skin, the precise cellular tropism of the virus in healthy subjects remains unclear. To begin to explore this question, we set out to identify the cellular receptors or co-receptors required for the infectious entry of MCV. Although several previously studied polyomavirus species have been shown to bind to cell surface sialic acid residues associated with glycolipids or glycoproteins, we found that sialylated glycans are not required for initial attachment of MCV virions to cultured human cell lines. Instead, glycosaminoglycans (GAGs), such as heparan sulfate (HS) and chondroitin sulfate (CS), serve as initial attachment receptors during the MCV infectious entry process. Using cell lines deficient in GAG biosynthesis, we found that N-sulfated and/or 6-O-sulfated forms of HS mediate infectious entry of MCV reporter vectors, while CS appears to be dispensable. Intriguingly, although cell lines deficient in sialylated glycans readily bind MCV capsids, the cells are highly resistant to MCV reporter vector-mediated gene transduction. This suggests that sialylated glycans play a post-attachment role in the infectious entry process. Results observed using MCV reporter vectors were confirmed using a novel system for infectious propagation of native MCV virions. Taken together, the findings suggest a model in which MCV infectious entry occurs via initial cell binding mediated primarily by HS, followed by secondary interactions with a sialylated entry co-factor. The study should facilitate the development of inhibitors of MCV infection and help shed light on the infectious entry pathways and cellular tropism of the virus

International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist

Data from: Consequences of breeding system for body condition and survival throughout the annual cycle of tidal marsh sparrows

An individual’s body condition and probability of survival can change throughout the annual cycle, based on the combined effects of many factors, including reproductive investment during breeding, colder temperatures during winter, and elevated risks during migration. We evaluated body condition and survival during breeding and non-breeding periods in two closely related species with notably different reproductive systems. Male and female saltmarsh sparrows (Ammodramus caudacutus) represent extremes in parental care: males perform none, leaving females to do everything from build nests to care for fledglings. In contrast, male and female seaside sparrows (A. maritimus) have bi-parental care and similar levels of reproductive investment, intermediate between male and female saltmarsh sparrows. Our results are consistent with the idea that females experience non-lethal effects of reproduction, and that differences between the breeding season and winter affect condition. In both species, females had lower scaled mass index (SMI) values than males during both breeding and non-breeding seasons, and female saltmarsh sparrows had lower SMI values than female seaside sparrows. Females carried more fat than males during the breeding season, and female, but not male, fat and muscle scores decreased over time, which is consistent with the adaptive mass hypothesis. In winter, all groups carried more fat and had higher muscle scores than when breeding, despite having lower SMI scores. Although we observed variation in body condition, within-season survival was uniformly high in both seasons, suggesting that sex, species, season, body size, and body condition have little impacts on within season survival. Comparisons with previously-published estimates of annual adult survival suggest that most mortality occurs during migration, even in these short-distance migrants. The importance of considering multiple aspects of body condition, multiple seasons, and difficult-to-monitor events, such as migration, should not be ignored when thinking about the events and processes that cumulatively determine population dynamics

Sub-Antarctic Biocultural Conservation Program

Article on the annual variation of abundance and composition in forest bird assemblages on Navarino Island, Cape Horn Biosphere Reserve, Chile