4,574 research outputs found

    Perkinsus marinus tissue distribution and seasonal variation in oysters Crassostrea virginica from Florida, Virginia and New York

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    Perkinsus marinus infection intensity was measured in eastern oysters Crassostrea virginica collected in October and December 1993, and March, May, and July 1994 from 3 U.S. sites: Apalachicola Bay (FL), Chesapeake Bay (VA), and Oyster Bay (Mr\u27). Gill, mantle, digestive gland. adductor muscle, hemolymph, and remaining tissue (including gonadal material and rectum) were dissected from 20 oysters from each site at each collection time. Samples were separately diagnosed for P. marin us infections by incubation in Ray\u27s Fluid Thioglycollate Medium (RFTM) and subsequent microscopic quantification of purified enlarged hypnospores. At all sampling times and sites, average P. marinus infection intensity (g wet wt tissue(-1) or ml hemolymph(-1)) was lowest in hemolymph samples, and generally highest in the digestive gland. Perkinsus marinus prevalence was 100% at both FL and NY sites for each of the 5 collection times, and, for the VA site, was less than 100% in only 1 month (May 1994). Seasonal intensity patterns and mean total body burdens differed among the sites. Average body burden was highest in VA during October and progressively declined to a minimum in May. This decline was probably due to mortality of heavily infected oysters and diminution of parasite activity associated with colder temperatures and reduced salinities. Intensities varied little during the months of October and December at both the FL and NY sites. Minimum average intensities were observed in March in FL oysters and May in NY oysters. Relatively high P. marinus infection levels that persisted throughout the winter in NY oysters compared with VA oysters could reflect constant high salinity in Long Island Sound which favors parasite activity, and also rapid decline in temperature in the fall that may have prevented epizootic oyster mortalities

    Asymmetric interlimb transfer of concurrent adaptation to opposing dynamic forces

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    Interlimb transfer of a novel dynamic force has been well documented. It has also been shown that unimanual adaptation to opposing novel environments is possible if they are associated with different workspaces. The main aim of this study was to test if adaptation to opposing velocity dependent viscous forces with one arm could improve the initial performance of the other arm. The study also examined whether this interlimb transfer occurred across an extrinsic, spatial, coordinative system or an intrinsic, joint based, coordinative system. Subjects initially adapted to opposing viscous forces separated by target location. Our measure of performance was the correlation between the speed profiles of each movement within a force condition and an ā€˜averageā€™ trajectory within null force conditions. Adaptation to the opposing forces was seen during initial acquisition with a significantly improved coefficient in epoch eight compared to epoch one. We then tested interlimb transfer from the dominant to non-dominant arm (D ā†’ ND) and vice-versa (ND ā†’ D) across either an extrinsic or intrinsic coordinative system. Interlimb transfer was only seen from the dominant to the non-dominant limb across an intrinsic coordinative system. These results support previous studies involving adaptation to a single dynamic force but also indicate that interlimb transfer of multiple opposing states is possible. This suggests that the information available at the level of representation allowing interlimb transfer can be more intricate than a general movement goal or a single perceived directional error

    Defining language impairments in a subgroup of children with autism spectrum disorder

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    Autism spectrum disorder (ASD) is diagnosed on the basis of core impairments in pragmatic language skills, which are found across all ages and subtypes. In contrast, there is significant heterogeneity in language phenotypes, ranging from nonverbal to superior linguistic abilities, as defined on standardized tests of vocabulary and grammatical knowledge. The majority of children are verbal but impaired in language, relative to age-matched peers. One hypothesis is that this subgroup has ASD and co-morbid specific language impairment (SLI). An experiment was conducted comparing children with ASD to children with SLI and typically developing controls on aspects of language processing that have been shown to be impaired in children with SLI: repetition of nonsense words. Patterns of performance among the children with ASD and language impairment were similar to those with SLI, and contrasted with the children with ASD and no language impairment and typical controls, providing further evidence for the hypothesis that a subgroup of children with ASD has co-morbid SLI. The findings are discussed in the context of brain imaging studies that have explored the neural bases of language impairment in ASD and SLI, and overlap in the genes associated with elevated risk for these disorders.M01 RR00533 - NCRR NIH HHS; R01 DC10290 - NIDCD NIH HHS; U19 DC03610 - NIDCD NIH HH

    Exercise Addiction Prevalence and Correlates in the Absence of Eating Disorder Symptomology: A Systematic Review and Meta-analysis

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    BACKGROUND: Exercise addiction (EA) can be debilitating and can be a symptom of an eating disorder. To date, the prevalence rates of EA without indicated eating disorders in the general population and associated correlates remain unreported. METHODS: Two authors searched major databases from inception to 31/12/2018 to identify studies investigating the prevalence of EA in any population without indicated eating disorders. We conducted a random effects meta-analysis to report (i) prevalence rates of EA using the exercise addiction inventory and exercise dependence scale and compare sub-populations, (ii) compare methods of EA measurement and explore heterogeneity, and (iii) report on correlates. RESULTS: A total of 13 studies including 3635 people were included. The prevalence of EA among general exercisers was 8.1% (95% CI 1.5%-34.2%), amateur competitive athletes was 5.0% (95% CI 1.3%-17.3%), and university students was 5.5% (95% CI 1.4-19.1%%). Overall prevalence rates varied depending on the EA measurement tool. EA subjects were more likely to have lower levels of overall wellbeing (only in amateur competitive athletes), higher anxiety levels, and have greater frontal brain activity. CONCLUSIONS: EA is prevalent in the absence of indicated eating disorders across populations but varies depending on measurement tool. Further research is needed to explore EA without indicated eating disorders in different populations using homogenous measurement tools, further determine psychological correlates, and examine which measures of EA without indicated eating disorders predict poor health outcomes

    The re-emergence of natural products for drug discovery in the genomics era

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    Natural products have been a rich source of compounds for drug discovery. However, their use has diminished in the past two decades, in part because of technical barriers to screening natural products in high-throughput assays against molecular targets. Here, we review strategies for natural product screening that harness the recent technical advances that have reduced these barriers. We also assess the use of genomic and metabolomic approaches to augment traditional methods of studying natural products, and highlight recent examples of natural products in antimicrobial drug discovery and as inhibitors of protein-protein interactions. The growing appreciation of functional assays and phenotypic screens may further contribute to a revival of interest in natural products for drug discovery

    The Power of Optimization Over Randomization in Designing Experiments Involving Small Samples

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    Human cerebrovascular responses to diving are not related to facial cooling

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    Ā© 2020 The Authors. Experimental Physiology Ā© 2020 The Physiological Society New Findings: What is the central question of this study? Does facial cooling-mediated stimulation of cutaneous trigeminal afferents associated with the diving response increase cerebral blood flow or are factors associated with breath-holding (e.g. arterial carbon dioxide accumulation, pressor response) more important in humans? What is the main finding and its importance? Physiological factors associated with breath-holding such as arterial carbon dioxide accumulation and the pressor response, but not facial cooling (trigeminal nerve stimulation), make the predominant contribution to diving response-mediated increases in cerebral blood flow in humans. Abstract: Diving evokes a pattern of physiological responses purported to preserve oxygenated blood delivery to vital organs such as the brain. We sought to uncouple the effects of trigeminal nerve stimulation on cerebral blood flow (CBF) from other modifiers associated with the diving response, such as apnoea and changes in arterial carbon dioxide tension. Thirty-seven young healthy individuals participated in separate trials of facial cooling (FC, 3Ā min) and cold pressor test (CPT, 3Ā min) under poikilocapnic (Protocol 1) and isocapnic conditions (Protocol 2), facial cooling while either performing a breath-hold (FCĀ +BH) or breathing spontaneously for a matched duration (FCĀ āˆ’BH) (Protocol 3), and BH during facial cooling (BHĀ +FC) or without facial cooling (BHĀ āˆ’FC) (Protocol 4). Under poikilocapnic conditions neither facial cooling nor CPT evoked a change in middle cerebral artery blood flow velocity (MCA vmean; transcranial Doppler) (PĀ >Ā 0.05 vs. baseline). Under isocapnic conditions, facial cooling did not change MCA vmean (PĀ >Ā 0.05), whereas CPT increased MCA vmean by 13% (PĀ Ā 0.05). Finally, MCA vmean and ICAQ were similarly increased by BH either with or without facial cooling. These findings suggest that physiological factors associated with BH, and not facial cooling (i.e. trigeminal nerve stimulation) per se, make the predominant contribution to increases in CBF during diving in humans

    The Health Behavior Information Needs and Preferences of Teenage and Young Adult Cancer Survivors

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    PURPOSE: This study aimed to establish teenage and young adult cancer survivors (TYACS') specific interest in receiving information on physical activity, diet, smoking, and alcohol consumption and their preferences regarding the delivery, format, and timing of such health behaviour information. METHODS: TYACS aged 13-25 years were invited to complete a questionnaire assessing the advice they had received in the past and their preferences on when and how health behavior information should be delivered. RESULTS: A total of 216 TYACS (mean age: 20 years; mean age at diagnosis: 16 years) completed the questionnaire. Approximately 40% of TYACS received no advice on physical activity and diet, and more than half (54%) received no advice on weight management. The majority (>70%) reported receiving no advice on smoking or alcohol consumption. Interest in receiving lifestyle advice was high overall (71%) but varied across behaviors, with TYACS reporting a greater level of interest in receiving advice on health protective behaviors (physical activity and diet) than health risk behaviors (smoking and alcohol consumption) (āˆ¼85% vs. āˆ¼15%, respectively). TYACS reported seeking health behavior information from health professionals and were most interested in information delivered online or in the form of a mobile app. Similar proportions (18%-29%) felt health behavior information should first be provided before, during, immediately after, and post-treatment. CONCLUSIONS: It is evident that there is a need to develop lifestyle interventions in a range of formats available to TYACS throughout the care pathway to address the health behavior information needs of young people with cancer

    Speech and language deficits are central to SETBP1 haploinsufficiency disorder

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    Expressive communication impairment is associated with haploinsufficiency of SETBP1, as reported in small case series. Heterozygous pathogenic loss-of-function (LoF) variants in SETBP1 have also been identified in independent cohorts ascertained for childhood apraxia of speech (CAS), warranting further investigation of the roles of this gene in speech development. Thirty-one participants (12 males, aged 0; 8-23; 2 years, 28 with pathogenic SETBP1 LoF variants, 3 with 18q12.3 deletions) were assessed for speech, language and literacy abilities. Broader development was examined with standardised motor, social and daily life skills assessments. Gross and fine motor deficits (94%) and intellectual impairments (68%) were common. Protracted and aberrant speech development was consistently seen, regardless of motor or intellectual ability. We expand the linguistic phenotype associated with SETBP1 LoF syndrome (SETBP1 haploinsufficiency disorder), revealing a striking speechĀ presentation that implicates both motor (CAS, dysarthria) and language (phonological errors) systems, with CAS (80%) being the most common diagnosis. In contrast to past reports, the understanding of language was rarely better preserved than language expression (29%). Language was typically low, to moderately impaired, with commensurate expression and comprehension ability. Children were sociable with a strong desire to communicate. Minimally verbal children (32%) augmented speech with sign language, gestures or digital devices. Overall, relative to general development, spoken language and literacy were poorer than social, daily living, motor and adaptive behaviour skills. Our findings show that poor communication is a central feature of SETBP1 haploinsufficiency disorder, confirming this gene as a strong candidate for speech and language disorders
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