Once a reservoir, always a reservoir? Seasonality affects the pathogen maintenance potential of amphibian hosts.

Host species that can independently maintain a pathogen in a host community and contribute to infection in other species are important targets for disease management. However, the potential of host species to maintain a pathogen is not fixed over time, and an important challenge is understanding how within- and across-season variability in host maintenance potential affects pathogen persistence over longer time scales relevant for disease management (e.g.

Evaluating environmental DNA as a tool for detecting an amphibian pathogen using an optimized extraction method.

Environmental DNA (eDNA) detection is a valuable conservation tool that can be used to identify and monitor imperiled or invasive species and wildlife pathogens. Batrachochytrium pathogens are of global conservation concern because they are a leading cause of amphibian decline. While eDNA techniques have been used to detect Batrachochytrium DNA in the environment, a systematic comparison of extraction methods across environmental samples is lacking.

Optimized Batrachochytrium dendrobatidis DNA extraction of swab samples results in imperfect detection particularly when infection intensities are low.

Accurate detection of the amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd) is critical for wildlife disease research; however, false negatives in detection do occur. Here we compared different DNA extraction methods to determine the threshold for Bd detection and identify an optimal extraction method to improve detection and quantification of the pathogen. We extracted both lab-created cell suspension standards using PrepMan Ultra, Chelex resin, and 3 spin column DNA extraction kits (Qiagen DNeasy Blood and Tissue, Zymo Quick DNA miniprep, and IBI gMAX mini kit), and further compared extraction methods using field-collected samples.

Defectlike structures and localized patterns in the cubic-quintic-septic Swift-Hohenberg equation.

We study numerically the cubic-quintic-septic Swift-Hohenberg (SH357) equation on bounded one-dimensional domains. Under appropriate conditions stripes with wave number k≈1 bifurcate supercritically from the zero state and form S-shaped branches resulting in bistability between small and large amplitude stripes. Within this bistability range we find stationary heteroclinic connections or fronts between small and large amplitude stripes, and demonstrate that the associated spatially localized defectlike structures either snake or fall on isolas.

Pattern analysis in a benthic bacteria-nutrient system.

We study steady states in a reaction-diffusion system for a benthic bacteria-nutrient model in a marine sediment over 1D and 2D domains by using Landau reductions and numerical path following methods. We point out how the system reacts to changes of the strength of food supply and ingestion. We find that the system has a stable homogeneous steady state for relatively large rates of food supply and ingestion, while this state becomes unstable if one of these rates decreases and Turing patterns such as hexagons and stripes start to exist.

Heterozygosity predicts clutch and egg size but not plasticity in a house sparrow population with no evidence of inbreeding.

We investigated the link between heterozygosity and the reaction norm attributes of reproductive performance in female house sparrows (Passer domesticus). We collected data on clutch size, egg size, hatching success and nestling survival in 2816 nesting attempts made by 791 marked individuals over a 16-year period. Pedigree analysis revealed no evidence of inbreeding.

Individual variation in parental care reaction norms: integration of personality and plasticity.

Personality (consistent differences between individuals in behavior) and plasticity (changes within individuals in behavior) are often viewed as separate and opposing phenomena. We tested this idea by analyzing parental care reaction norms in a bird that exhibits biparental care. Personality in provisioning behavior existed (r(ic) = 0.

Heterozygosity and extra-pair paternity: biased tests result from the use of shared markers.

Recent studies of extra-pair paternity have found support for the idea that heterozygous males have an advantage in siring offspring. Most studies use DNA microsatellite loci to determine paternity and then use the same loci to estimate individual heterozygosity. However, because the likelihood of detecting extra-pair offspring depends on the combinations of parental alleles, it is possible that biases arise from particular allele combinations.