324 research outputs found
Multiâscale effects of land cover, weather, and fire on Columbian sharpâtailed grouse
Columbian sharpâtailed grouse (Tympanuchus phasianellus columbianus) are endemic to grassland and shrubâsteppe ecosystems of western North America, yet their distribution has contracted to \u3c10% of their historical range. Primary threats to Columbian sharpâtailed grouse include loss of native habitat and conversion to agriculture, reductions in habitat once provided by the Conservation Reserve Program (CRP), wildfire, and drought conditions, yet populationâlevel consequences of these threats and their spatioâtemporal scales of effect are poorly understood. We evaluated multiâscale effects of land cover, weather, and fire histories on patterns of abundance and productivity for Columbian sharpâtailed grouse populations during 1995â2020 in Idaho, USA, using mixedeffects generalized regression and remotely sensed data. We demonstrated negative effects of fire, tree encroachment, and bare ground, positive effects of spring and summer precipitation and cover of shrubs and perennial forbs and grasses, and positive effects of CRP on grouse abundance that changed in magnitude with cover of perennials and shrubs near leks (i.e., strongest effects when average cover of shrubs and perennial forbs and grasses were less abundant). We also demonstrated per capita recruitment of Columbian sharpâtailed grouse is positively associated with lateâsummer greenness. Our results show that several suspected threats have measurable, populationâlevel impacts to Columbian sharpâtailed grouse within Idaho. Moreover, our results suggest ongoing changes occurring within the core range of Columbian sharpâtailed grouse, including loss of CRP cover to tilled agriculture and changes to wildfire and precipitation dynamics are likely to have negative effects on populations
Cardiorespiratory fitness and preserved medial temporal lobe volume in Alzheimer's Disease
This is not the final published version.Exercise and cardiorespiratory (CR) fitness may moderate age-related regional brain changes in nondemented older adults (ND). The relationship of fitness to Alzheimer's disease (AD) related brain change is understudied, particularly in the hippocampus which is disproportionately affected in early AD. The role of apolipoprotein E4 (apoE4) genotype in modulating this relationship is also unknown. Nondemented (n=56) and early-stage AD subjects (n=61) over age 65 had MRI and CR fitness assessments. Voxel-based morphometry (VBM) techniques were utilized to identify AD-related atrophy. We analyzed the relationship of CR fitness with white and gray matter within groups, assessed fitness-related brain volume change in areas most affected by AD-related atrophy, and then analyzed differential fitness-brain relationships between apoE4 carriers. Atrophy was present in the medial temporal, temporal, and parietal cortices in subjects with mild AD. There was a significant positive correlation of CR fitness with parietal and medial temporal volume in AD subjects. ND subjects did not have a significant relationship between brain volume and CR fitness in the global or SVC analyses. There was not a significant interaction for fitness Ă apoE4 genotype in either group. In early-stage AD, cardiorespiratory fitness is associated with regional brain volumes in the medial temporal and parietal cortices suggesting that maintaining cardiorespiratory fitness may modify AD-related brain atrophy
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Intraoperative Monitoring of the Cochlear Nerve during Neurofibromatosis Type-2 Vestibular Schwannoma Surgery and Description of a "Test Intracochlear Electrode".
Objectives âA decision on whether to insert a cochlear implant can be made in neurofibromatosis 2 (NF2) if there is objective evidence of cochlear nerve (CN) function post vestibular schwannoma (VS) excision. We aimed to develop intraoperative CN monitoring to help in this decision. Design âWe describe the intraoperative monitoring of a patient with NF2 and our stimulating and recording set up. A novel test electrode is used to stimulate the CN electrically. Setting âThis study was set at a tertiary referral center for skull base pathology. Main outcome measure âPreserved auditory brainstem responses leading to cochlear implantation. Results âElectrical auditory brainstem response (EABR) waveforms will be displayed from different stages of the operation. A cochlear implant was inserted at the same sitting based on the EABR. Conclusion âElectrically evoked CN monitoring can provide objective evidence of CN function after VS excision and aid in the decision-making process of hearing rehabilitation in patients who will be rendered deaf
Low-Tech Riparian and Wet Meadow Restoration Increases Vegetation Productivity and Resilience Across Semiarid Rangelands
Restoration of riparian and wet meadow ecosystems in semiarid rangelands of the western United States is a high priority given their ecological and hydrological importance in the region. However, traditional restoration approaches are often intensive and costly, limiting the extent over which they can be applied. Practitioners are increasingly trying new restoration techniques that are more costâeffective, less intensive, and can more practically scale up to the scope of degradation. Unfortunately, practitioners typically lack resources to undertake outcomeâbased evaluations necessary to judge the efficacy of these techniques. In this study, we use freely available, satellite remote sensing to explore changes in vegetation productivity (normalized difference vegetation index) of three distinct, lowâtech, riparian and wet meadow restoration projects. Case studies are presented that range in geographic location (Colorado, Oregon, and Nevada), restoration practice (Zeedyk structures, beaver dam analogs, and grazing management), and time since implementation. Restoration practices resulted in increased vegetation productivity of up to 25% and increased annual persistence of productive vegetation. Improvements in productivity with time since restoration suggest that elevated resilience may further enhance wildlife habitat and increase forage production. Longâterm, documented outcomes of conservation are rare; we hope our findings empower practitioners to further monitor and explore the use of lowâtech methods for restoration of ecohydrologic processes at meaningful spatial scales
Vitamin Enhanced Waters and Polyphenol Rich Beverages Analyzed for Antioxidant Capacity and Antioxidants/Calorie
The purpose of this study was to analyze polyphenol rich beverages (vitamin enhanced waters (VEWs), fruit juices and berry juices) to determine free polyphenol concentrations and free polyphenols per Calorie based on a serving size. The FolinâCiocalteu reagent was used in a colorimetric assay based on a catechin standard. Fruit and berry juices contained, on average, more than eight-times the concentration of free polyphenols when compared to VEWs. When Calories per serving were taken into consideration, fruit and berry juices contained more than twice the free polyphenols per Calorie
Rapid online assessment of reading ability
Published18 March 2021An accurate model of the factors that contribute to individual differences in reading ability depends
on data collection in large, diverse and representative samples of research participants. However, that
is rarely feasible due to the constraints imposed by standardized measures of reading ability which
require test administration by trained clinicians or researchers. Here we explore whether a simple,
two-alternative forced choice, time limited lexical decision task (LDT), self-delivered through the webbrowser,
can serve as an accurate and reliable measure of reading ability. We found that performance
on the LDT is highly correlated with scores on standardized measures of reading ability such as the
Woodcock-Johnson Letter Word Identification test (r = 0.91, disattenuated r = 0.94). Importantly,
the LDT reading ability measure is highly reliable (r = 0.97). After optimizing the list of words and
pseudowords based on item response theory, we found that a short experiment with 76 trials
(2â3 min) provides a reliable (r = 0.95) measure of reading ability. Thus, the self-administered, Rapid
Online Assessment of Reading ability (ROAR) developed here overcomes the constraints of resourceintensive,
in-person reading assessment, and provides an efficient and automated tool for effective
online research into the mechanisms of reading (dis)ability.We would like to thank the Pavlovia and PsychoPy team for their support on the browser-based experiments.
This work was funded by NIH NICHD R01HD09586101, research grants from Microsoft and Jacobs Foundation
Research Fellowship to J.D.Y
Homozygous microdeletion of exon 5 in ZNF277 in a girl with specific language impairment
Peer reviewedPublisher PD
Weight-loss intervention using implementation intentions and mental imagery: A randomised control trial study protocol
Background: Overweight and obesity are major health problems worldwide. This protocol describes the HEALTHI (Healthy Eating and Active LifesTyle Health Intervention) Program, a 12-week randomised-controlled weight-loss intervention that adopts two theory-based intervention techniques, mental imagery and implementation intentions, a behaviour-change technique based on planning that have been shown to be effective in promoting health-behaviour change in previous research. The effectiveness of goal-reminder text messages to augment intervention effects will also be tested. The trial will determine the effects of a brief, low cost, theory-based weight-loss intervention to improve dietary intake and physical activity behaviour and facilitate weight-loss in overweight and obese individuals. Methods/Design: Overweight or obese participants will be randomly allocated to one of three conditions: (1) a psycho-education plus an implementation intentions and mental imagery condition; (2) a psycho-education plus an implementation intentions and mental imagery condition with text messages; or (3) a psycho-education control condition. The intervention will be delivered via video presentation to increase the intervention's applicability in multiple contexts and keep costs low. We hypothesise that the intervention conditions will lead to statistically-significant changes in the primary and secondary outcome variables measured at 6 and 12 weeks post-intervention relative to the psycho-education control condition after controlling for baseline values. The primary outcome variable will be body weight and secondary outcome variables will be biomedical (body mass, body fat percentage, muscle mass, waist-hip circumference ratio, systolic and diastolic blood pressure, low-density lipoprotein, high-density lipoprotein, total cholesterol, triglycerides, blood glucose and insulin levels), psychological (quality of life, motivation, risk perception, outcome expectancy, intention, action self-efficacy, maintenance self-efficacy, goal setting and planning), and behavioural (self-reported diet intake, and physical activity involvement) measures. We also expect the intervention condition augmented with text messages to lead to statistically significant differences in the primary and secondary outcome variables at the follow up periods after controlling for baseline values. Discussion: The planned trial will test the effectiveness of the theory-based HEALTHI program intervention to reduce weight and salient psychological, biomedical, and behavioural outcomes in overweight and obese adults. The study has been designed to maximise applicability to real world settings and could be integrated into existing weight management practices
Glucagon-like peptide-1 and its class B G protein-coupled receptors: A long march to therapeutic successes
Theglucagon-likepeptide (GLP)-1receptor (GLP-1R) is a class B G protein-coupled receptor (GPCR) that mediates the action of GLP-1, a peptide hormone secretedfromthreemajor tissues inhumans,enteroendocrine L cells in the distal intestine, a cells in the pancreas, and the central nervous system, which exerts important actions useful in the management of type 2 diabetes mellitus and obesity, including glucose homeostasis and regulation of gastric motility and food intake. Peptidic analogs of GLP-1 have been successfully developed with enhanced bioavailability and pharmacological activity. Physiologic and biochemical studies with truncated, chimeric, and mutated peptides and GLP-1R variants, together with ligand-bound crystal structures of the extracellular domain and the first three-dimensional structures of the 7-helical transmembrane domain of class B GPCRs, have provided the basis for a twodomain-binding mechanism of GLP-1 with its cognate receptor. Although efforts in discovering therapeutically viable nonpeptidicGLP-1R agonists have been hampered, small-moleculemodulators offer complementary chemical tools to peptide analogs to investigate ligand-directed biased cellular signaling of GLP-1R. The integrated pharmacological and structural information of different GLP-1 analogs and homologous receptors give new insights into the molecular determinants of GLP-1R ligand selectivity and functional activity, thereby providing novel opportunities in the design and development of more efficacious agents to treat metabolic disorders
Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.
Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis
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