1,972 research outputs found

    Interaction of Seed Dispersal and Environmental Filtering Affects Woody Encroachment Patterns in Coastal Grassland

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    Encroachment of woody plants into grasslands has occurred worldwide and includes coastal ecosystems. This conversion process is mediated by seed dispersal patterns, environmental filtering, and biotic interactions. As spatiotemporally heterogeneous, harsh environments, barrier islands present a unique set of challenges for dispersal and establishment. Environmental conditions act as filters on dispersed seeds, thereby influencing encroachment and distribution patterns. Seldom have patterns of propagule dispersal been considered in the context of woody encroachment. We quantified dispersal and post‐dispersal processes of an encroaching woody population of Morella cerifera relative to directional rate of encroachment and observed distribution patterns on an Atlantic coastal barrier island with strong environmental filtering. We analyzed historic foredune elevation as a proxy for reduced interior environmental stress. The dispersal kernel was leptokurtic, a common characteristic of expanding populations, but rate of encroachment has slowed since 2005. Expansion pattern was related to foredune elevation, which limits encroachment below a threshold elevation. This difference between dispersal kernel behavior and encroachment rate is due to limited availability of suitable habitat for Morella and temporal variability in chlorides during the time of germination. Our results demonstrate that processes mediating seeds and seedling success must be accounted for to better understand establishment patterns of encroaching woody plants

    Mandarin Market Segments Based on Consumer Sensory Evaluations

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    Ninety-five consumers in seven grocery stores tasted unidentified peeled sections of three mandarins (a tangerine, a satsuma, and a clementine), and provided demographic and purchase information. Forty-four percent of the respondents preferred tangerines, 34 percent satsumas, and 22 percent clementines. The probability of preferring each of type of mandarin was estimated from internal quality analysis of paired samples, as well as from demographic and purchase responses. Model simulations were used to recommend harvest standards for satsumas based on Brix-to-acid ratios.Demand and Price Analysis, Food Consumption/Nutrition/Food Safety,

    An amphipathic helix enables septins to sense micrometer-scale membrane curvature

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    © The Authors, 2019. This article is distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 4.0 International License. The definitive version was published in Journal of Cell Biology (2019), doi:10.1083/jcb.201807211.Cell shape is well described by membrane curvature. Septins are filament-forming, GTP-binding proteins that assemble on positive, micrometer-scale curvatures. Here, we examine the molecular basis of curvature sensing by septins. We show that differences in affinity and the number of binding sites drive curvature-specific adsorption of septins. Moreover, we find septin assembly onto curved membranes is cooperative and show that geometry influences higher-order arrangement of septin filaments. Although septins must form polymers to stay associated with membranes, septin filaments do not have to span micrometers in length to sense curvature, as we find that single-septin complexes have curvature-dependent association rates. We trace this ability to an amphipathic helix (AH) located on the C-terminus of Cdc12. The AH domain is necessary and sufficient for curvature sensing both in vitro and in vivo. These data show that curvature sensing by septins operates at much smaller length scales than the micrometer curvatures being detected.We thank the Gladfelter laboratory and Danny Lew for useful discussions, Matthias Garten for ideas in setting up the rod assay, and the University of North Carolina EM facility (Victoria Madden and Kristen White) for support with scanning electron microscope. This work was supported by a Howard Hughes Medical Institute Faculty Scholars award to A.S. Gladfelter, and K.S. Cannon was supported in part by a grant from the National Institute of General Medical Sciences under award T32 GM119999.2019-07-0

    Inter and intra-hemispheric structural imaging markers predict depression relapse after electroconvulsive therapy: a multisite study.

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    Relapse of depression following treatment is high. Biomarkers predictive of an individual's relapse risk could provide earlier opportunities for prevention. Since electroconvulsive therapy (ECT) elicits robust and rapidly acting antidepressant effects, but has a >50% relapse rate, ECT presents a valuable model for determining predictors of relapse-risk. Although previous studies have associated ECT-induced changes in brain morphometry with clinical response, longer-term outcomes have not been addressed. Using structural imaging data from 42 ECT-responsive patients obtained prior to and directly following an ECT treatment index series at two independent sites (UCLA: n = 17, age = 45.41±12.34 years; UNM: n = 25; age = 65.00±8.44), here we test relapse prediction within 6-months post-ECT. Random forests were used to predict subsequent relapse using singular and ratios of intra and inter-hemispheric structural imaging measures and clinical variables from pre-, post-, and pre-to-post ECT. Relapse risk was determined as a function of feature variation. Relapse was well-predicted both within site and when cohorts were pooled where top-performing models yielded balanced accuracies of 71-78%. Top predictors included cingulate isthmus asymmetry, pallidal asymmetry, the ratio of the paracentral to precentral cortical thickness and the ratio of lateral occipital to pericalcarine cortical thickness. Pooling cohorts and predicting relapse from post-treatment measures provided the best classification performances. However, classifiers trained on each age-disparate cohort were less informative for prediction in the held-out cohort. Post-treatment structural neuroimaging measures and the ratios of connected regions commonly implicated in depression pathophysiology are informative of relapse risk. Structural imaging measures may have utility for devising more personalized preventative medicine approaches

    Age and Body Satisfaction Predict Diet Adherence in Adolescents with Inflammatory Bowel Disease

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    The aim of the current study was to determine whether age and body satisfaction predict dietary adherence in adolescents with Inflammatory Bowel Disease (IBD), and whether older females are less adherent than younger males and females. Forty-four participants aged 10-21 with IBD were recruited. Participants provided informed consent and demographics. Body satisfaction was measured by a questionnaire and a task in which participants selected their current and ideal body image out of silhouettes depicting bodies ranging from underweight to obese. Adherence was measured by marking a 100mm visual analog scale, the 1-week completion of a dietary log, and a questionnaire evaluating coping strategies used for overcoming obstacles to dietary adherence. Age was related to dietary adherence, with younger children being more likely to adhere. Participants more satisfied with their body reported better dietary adherence. Findings remained consistent across multiple measures of body satisfaction and adherence. Healthcare providers and parents should be informed of these findings in order to improve adherence

    Interplay of septin amphipathic helices in sensing membrane-curvature and filament bundling

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    © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Woods, B. L., Cannon, K. S., Vogt, E. J. D., Crutchley, J. M., & Gladfelter, A. S. Interplay of septin amphipathic helices in sensing membrane-curvature and filament bundling. Molecular Biology of the Cell, 32(20), (2021): mbcE20050303, https://doi.org/10.1091/mbc.E20-05-0303.The curvature of the membrane defines cell shape. Septins are GTP-binding proteins that assemble into heteromeric complexes and polymerize into filaments at areas of micron-scale membrane curvature. An amphipathic helix (AH) domain within the septin complex is necessary and sufficient for septins to preferentially assemble onto micron-scale curvature. Here we report that the nonessential fungal septin, Shs1, also has an AH domain capable of recognizing membrane curvature. In a septin mutant strain lacking a fully functional Cdc12 AH domain (cdc12-6), the C-terminal extension of Shs1, containing an AH domain, becomes essential. Additionally, we find that the Cdc12 AH domain is important for regulating septin filament bundling, suggesting septin AH domains have multiple, distinct functions and that bundling and membrane binding may be coordinately controlled.This work was supported by National Institutes of Health (NIH) Grant no. R01GM-130934 to A.S.G. B.L.W. was supported by the NIH Training Grant no. 2T32AI052080-16. K.S.C. and E.J.D.V. were supported in part by a grant from the National Institute of General Medical Sciences under award T32 GM119999

    Anticoagulant rodenticides on our public and community lands: spatial distribution of exposure and poisoning of a rare forest carnivore.

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    Anticoagulant rodenticide (AR) poisoning has emerged as a significant concern for conservation and management of non-target wildlife. The purpose for these toxicants is to suppress pest populations in agricultural or urban settings. The potential of direct and indirect exposures and illicit use of ARs on public and community forest lands have recently raised concern for fishers (Martes pennanti), a candidate for listing under the federal Endangered Species Act in the Pacific states. In an investigation of threats to fisher population persistence in the two isolated California populations, we investigate the magnitude of this previously undocumented threat to fishers, we tested 58 carcasses for the presence and quantification of ARs, conducted spatial analysis of exposed fishers in an effort to identify potential point sources of AR, and identified fishers that died directly due to AR poisoning. We found 46 of 58 (79%) fishers exposed to an AR with 96% of those individuals having been exposed to one or more second-generation AR compounds. No spatial clustering of AR exposure was detected and the spatial distribution of exposure suggests that AR contamination is widespread within the fisher's range in California, which encompasses mostly public forest and park lands Additionally, we diagnosed four fisher deaths, including a lactating female, that were directly attributed to AR toxicosis and documented the first neonatal or milk transfer of an AR to an altricial fisher kit. These ARs, which some are acutely toxic, pose both a direct mortality or fitness risk to fishers, and a significant indirect risk to these isolated populations. Future research should be directed towards investigating risks to prey populations fishers are dependent on, exposure in other rare forest carnivores, and potential AR point sources such as illegal marijuana cultivation in the range of fishers on California public lands

    Patterns of Natural and Human-Caused Mortality Factors of a Rare Forest Carnivore, the Fisher (Pekania pennanti) in California.

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    Wildlife populations of conservation concern are limited in distribution, population size and persistence by various factors, including mortality. The fisher (Pekania pennanti), a North American mid-sized carnivore whose range in the western Pacific United States has retracted considerably in the past century, was proposed for threatened status protection in late 2014 under the United States Endangered Species Act by the United States Fish and Wildlife Service in its West Coast Distinct Population Segment. We investigated mortality in 167 fishers from two genetically and geographically distinct sub-populations in California within this West Coast Distinct Population Segment using a combination of gross necropsy, histology, toxicology and molecular methods. Overall, predation (70%), natural disease (16%), toxicant poisoning (10%) and, less commonly, vehicular strike (2%) and other anthropogenic causes (2%) were causes of mortality observed. We documented both an increase in mortality to (57% increase) and exposure (6%) from pesticides in fishers in just the past three years, highlighting further that toxicants from marijuana cultivation still pose a threat. Additionally, exposure to multiple rodenticides significantly increased the likelihood of mortality from rodenticide poisoning. Poisoning was significantly more common in male than female fishers and was 7 times more likely than disease to kill males. Based on necropsy findings, suspected causes of mortality based on field evidence alone tended to underestimate the frequency of disease-related mortalities. This study is the first comprehensive investigation of mortality causes of fishers and provides essential information to assist in the conservation of this species

    Treatment Use Among Children with Tourette Syndrome Living in The United States, 2014

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    Treatment of Tourette syndrome (TS) can be complicated by changes over time in tic expression, severity, and co-occurring disorders. Using the 2014 National Survey of the Diagnosis and Treatment of ADHD and Tourette Syndrome, this study provides descriptive estimates of the use of behavioral interventions and medication among children living with TS. Parent-reported data on 115 children aged 5–17 years ever diagnosed with TS were analyzed to provide descriptive, unweighted results. Overall, 77.4% of children had current or past use of any TS treatment; 59.1% ever used behavioral interventions and 56.1% had ever taken TS medication. Children with moderate” or “severe” versus “mild” TS, ≥1 co-occurring disorders, and tics that interfered with functioning were significantly more likely to have used one or more TS treatments. Side effects were reported for 84.4% of children who took TS medication. Most parents of children with current TS (87.2%) were satisfied with the management of their child\u27s TS. However, parents of children with “moderate” or “severe” current TS were significantly more dissatisfied compared to parents of children with “mild” TS. Findings from this study could be used to inform efforts to support children living with TS and their families
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