Hierarchical differences in the encoding of amplitude modulation in the subcortical auditory system of awake nonhuman primates.

Sinusoidal amplitude modulation (SAM) is a key feature of complex sounds. Although psychophysical studies have characterized SAM perception, and neurophysiological studies in anesthetized animals report a transformation from the cochlear nucleus' (CN; brainstem) temporal code to the inferior colliculus' (IC; midbrain's) rate code, none have used awake animals or nonhuman primates to compare CN and IC's coding strategies to modulation-frequency perception. To address this, we recorded single-unit responses and compared derived neurometric measures in the CN and IC to psychometric measures of modulation frequency (MF) discrimination in macaques.

The relationship between distortion product otoacoustic emissions and audiometric thresholds in the extended high-frequency range.

Distortion product otoacoustic emissions (DPOAEs) and behavioral audiometry are routinely used for hearing screening and assessment. These measures provide related information about hearing status as both are sensitive to cochlear pathologies. However, DPOAE testing is quicker and does not require a behavioral response.

Comparing genome-based estimates of relatedness for use in pedigree-based conservation management.

Researchers have long debated which estimator of relatedness best captures the degree of relationship between two individuals. In the genomics era, this debate continues, with relatedness estimates being sensitive to the methods used to generate markers, marker quality, and levels of diversity in sampled individuals. Here, we compare six commonly used genome-based relatedness estimators (kinship genetic distance [KGD], Wang maximum likelihood [TrioML], Queller and Goodnight [R ], Kinship INference for Genome-wide association studies [KING-robust), and pairwise relatedness [R ], allele-sharing coancestry [AS]) across five species bred in captivity-including three birds and two mammals-with varying degrees of reliable pedigree data, using reduced-representation and whole genome resequencing data.

Waste not, want not: Microsatellites remain an economical and informative technology for conservation genetics.

Comparisons of microsatellites and single-nucleotide polymorphisms (SNPs) have found that SNPs outperform microsatellites in population genetic analyses, questioning the continued utility of microsatellites in population and landscape genetics. Yet, highly polymorphic markers may be of value in species that have reduced genetic variation. This study repeated previous analyses that used microsatellites with SNPs developed from ddRAD sequencing in the black-capped vireo source-sink system.

The crucial role of genome-wide genetic variation in conservation.

The unprecedented rate of extinction calls for efficient use of genetics to help conserve biodiversity. Several recent genomic and simulation-based studies have argued that the field of conservation biology has placed too much focus on conserving genome-wide genetic variation, and that the field should instead focus on managing the subset of functional genetic variation that is thought to affect fitness. Here, we critically evaluate the feasibility and likely benefits of this approach in conservation.

Landscape genetic inferences vary with sampling scenario for a pond-breeding amphibian.

A critical decision in landscape genetic studies is whether to use individuals or populations as the sampling unit. This decision affects the time and cost of sampling and may affect ecological inference. We analyzed 334 Columbia spotted frogs at 8 microsatellite loci across 40 sites in northern Idaho to determine how inferences from landscape genetic analyses would vary with sampling design.

Asymmetrical gene flow of the recently delisted passerine black-capped vireo () indicates source-sink dynamics in central Texas.

Habitat fragmentation can produce metapopulations or source-sink systems in which dispersal in crucial for population maintenance. Our objective was to investigate connectivity among black-capped vireo () populations in tandem with a demographic study (Biological Conservation, 2016, 203, 108-118) to elucidate if central Texas populations act as a source-sink system. We genotyped 343 individuals at 12 microsatellite loci to elucidate the movement ecology of the black-capped vireo in central Texas surrounding Fort Hood; the largest and most stable breeding population of black-capped vireos inhabit Fort Hood.

Inconsistent use of multiple comparison corrections in studies of population genetic structure: Are some type I errors more tolerable than others?

Studies of genetic population structure often involve numerous tests of Hardy-Weinberg equilibrium (HWE), linkage disequilibrium (LD) and genetic differentiation. Tests of HWE or LD are important precursors to population structure assessments. When conducting multiple related statistical tests, type I error increases, e.

Effects of noise overexposure on tone detection in noise in nonhuman primates.

This report explores the consequences of acoustic overexposures on hearing in noisy environments for two macaque monkeys trained to perform a reaction time detection task using a Go/No-Go lever release paradigm. Behavioral and non-invasive physiological assessments were obtained before and after narrowband noise exposure. Physiological measurements showed elevated auditory brainstem response (ABR) thresholds and absent distortion product otoacoustic emissions (DPOAEs) post-exposure relative to pre-exposure.