9 research outputs found
Inferring inter‑colony movement within metapopulations of yellow‑footed rock‑wallabies using estimates of kinship
Understanding the exchange of individuals between wildlife populations, particularly those with naturally fragmented habitats, is important for the effective management of these species. This is of particular consequence when the species is of conservation concern, and isolated populations may be lost due to pressures from predation or competition, or catastrophic events such as wildfire. Here we demonstrate the use kinship and population structure analysis to show potential recent movement between colonies in metapopulations of yellow-footed rock-wallaby (Petrogale xanthopus Gray 1854) at two sites in the Grey Range of Queensland, and at four sites in the Gawler Ranges of South Australia. These colonies are also compared to a single colony from the Flinders Ranges, a connected landscape of rock-wallaby habitat. Using reduced representation next-generation sequencing, we acquired and filtered a set of similar to 17,000 single-nucleotide polymorphisms to examine population genetic variation, structure and relationships within populations, and also identify putative migrants. Initial STRUCTURE analysis re-confirmed each population should be considered separately. Tests of population genetic variation identify several colonies appearing to be experiencing genetic erosion, also with low calculated effective population sizes (Ne = 4.5-36.6). Pairwise comparisons of individual relatedness (relatedness coeffiecients; r) implied several contemporary movement events between colonies within both the Gawler and Grey Ranges (r > 0.125), which was then affirmed with tests for putative first generation migrants. These results are of particular note in South Australia, where threat abatement (management of key predators and competitors) may facilitate dispersion. Additionally, in Queensland, colonies are separated by anthropogenic barriers: predator exclusion fencing designed to exclude dingoes ( 0.125), which was then affirmed with tests for putative first generation migrants. These results are of particular note in South Australia, where threat abatement (management of key predators and competitors) may facilitate dispersion. Additionally, in Queensland, colonies are separated by anthropogenic barriers: predator exclusion fencing designed to exclude dingoes (Canis familiaris) from grazing land, which may hinder dispersal. This work highlights the usefulness of population genetics to inform management outcomes in wildlife, in this case, highlighting the need for threatened species management at the landscape level
The genetic architecture of the human cerebral cortex
The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder
Evaluation of medetomidine-ketamine and medetomidine-ketamine-butorphanol for the field anesthesia of free-ranging dromedary camels (Camelus dromedarius) in Australia
We report the clinical course and physiologic and anesthetic data for a case series of 76 free-ranging dromedary camels (Camelus dromedarius) chemically restrained, by remote injection from a helicopter, in the rangelands of Western Australia and South Australia, 2008–11, to attach satellite-tracking collars. Fifty-five camels were successfully anesthetized using medetomidine-ketamine (MK, n = 27) and medetomidine-ketamine-butorphanol (MKB, n = 28); the induction of anesthesia in 21 animals was considered unsuccessful. To produce reliable anesthesia for MK, medetomidine was administered at 0.22 mg/kg (±SD = 0.05) and ketamine at 2.54 mg/kg (±0.56), and for MKB, medetomidine was administered at 0.12 mg/kg (±0.05), ketamine at 2.3 mg/kg (±0.39), and butorphanol at 0.05 mg/kg (±0.02). Median time-to-recumbency for MKB (8.5 min) was 2.5 min shorter than for MK (11 min) (P = 0.13). For MK, the reversal atipamezole was administered at 0.24 mg/kg (±0.10), and for MKB, atipamezole was administered at 0.23 mg/kg (±0.13) and naltrexone at 0.17 mg/kg (±0.16). Median time-to-recovery was 1 min shorter for MK (5 min) than MKB (6 min; P = 0.02). Physiologic parameters during recumbency were not clinically different between the two regimes. Both regimes were suitable to safely anesthetize free-ranging camels; however, further investigation is required to find the safest, most consistent, and logistically practical combination
At the interface of sensory and motor dysfunctions and Alzheimer's disease.
Recent evidence indicates that sensory and motor changes may precede the cognitive symptoms of Alzheimer's disease (AD) by several years and may signify increased risk of developing AD. Traditionally, sensory and motor dysfunctions in aging and AD have been studied separately. To ascertain the evidence supporting the relationship between age-related changes in sensory and motor systems and the development of AD and to facilitate communication between several disciplines, the National Institute on Aging held an exploratory workshop titled "Sensory and Motor Dysfunctions in Aging and AD." The scientific sessions of the workshop focused on age-related and neuropathologic changes in the olfactory, visual, auditory, and motor systems, followed by extensive discussion and hypothesis generation related to the possible links among sensory, cognitive, and motor domains in aging and AD. Based on the data presented and discussed at this workshop, it is clear that sensory and motor regions of the central nervous system are affected by AD pathology and that interventions targeting amelioration of sensory-motor deficits in AD may enhance patient function as AD progresses