84 research outputs found

    Simplified approach to understanding boundary layer structure impacts on tropical cyclone intensity, A

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    2018 Fall.Includes bibliographical references.The relationship between tropical cyclone boundary layer (TCBL) structure and tropical cyclone (TC) intensity change is difficult to understand due to limited observations of the complex, non-linear interactions at both the top and bottom boundaries of the TCBL. Consequently, there are debates on how the TCBL interacts with surface friction and how these interactions affect TC intensity change. To begin to address these questions, a conceptual framework of how axisymmetric dynamics within the TCBL can impact TC intensity change is developed from first principles in the form of a new, simple logistic growth equation (LGE). Although this LGE bears some similarities to the operational LGE Model (LGEM; DeMaria 2009), the difference is that our growth-limiting term incorporates TCBL structure and surface drag. The carrying capacity of the LGE—termed the instantaneous logistic potential intensity (ILPI) in this study—is used to explore the relationship between TCBL structure and TC intensity. The LGE is also further solved for the drag coefficient (CD) to explore the relationships between it and both TCBL structure and TC intensity. The validity of this new LGE framework is then explored in idealized numerical modeling using the axisymmetric version of Cloud Model 1 (CM1; Bryan and Fritsch 2002). Results show that CM1 exhibits changes to TCBL structure and TC intensity that are consistent with the LGE framework. Sensitivity of these results to the turbulent mixing lengths, Lh and Lv, are also explored, and general LGE relation- ships still hold as CD is increased. Finally, the LGE framework is applied to observations, and initial CD retrievals indicate that while this new method is low compared to Bell et al. (2012), they are still plausible estimates

    Caring to make a difference with vulnerable women: the impact of targeted support on birth-related outcomes and experiences

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    We report findings from a mixed-methods study to compare birth outcomes and experiences between vulnerable women who had or had not received targeted support from a specialist midwifery team and/or a third-sector organisation. Sociodemographic and birth-related outcome data from a 12-month birth cohort were used to explore differences between a) vulnerable and non-vulnerable women; and b) vulnerable women who had and those who had not received targeted support. Seventeen women who had or had not received targeted support were interviewed. Vulnerable mothers were significantly more likely to be younger, from a minority ethnic group, access care later in pregnancy and have a baby born earlier and at a lower birth weight. A higher percentage of women who received targeted support had a spontaneous birth, a vaginal presentation at birth and were less likely to use anaesthesia during labour when compared with unsupported vulnerable women. Targeted support was associated with reassurance, increased parental confidence and wellbeing. Key practice and policy-based implications are considered

    Oscillations in Neural Drive and Age-related Reductions in Force Steadiness with a Cognitive Challenge

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    A cognitive challenge when imposed during a low-force isometric contraction will exacerbate sex- and age-related decreases in force steadiness, but the mechanism is not known. We determined the role of oscillations in the common synaptic input to motor units on force steadiness during a muscle contraction with a concurrent cognitive challenge. Forty-nine young adults (19–30 yr; 25 women, 24 men) and 36 old adults (60–85 yr; 19 women, 17 men) performed a cognitive challenge (counting backward by 13) during an isometric elbow flexion task at 5% of maximal voluntary contraction. Single-motor units were decomposed from high-density surface EMG recordings. For a subgroup of participants, motor units were matched during control and cognitive challenge trials, so the same motor unit was analyzed across conditions. Reduced force steadiness was associated with greater oscillations in the synaptic input to motor units during both control and cognitive challenge trials (r = 0.45–0.47, P \u3c 0.01). Old adults and young women showed greater oscillations in the common synaptic input to motor units and decreased force steadiness when the cognitive challenge was imposed, but young men showed no change across conditions (session × age × sex, P \u3c 0.05). Oscillations in the common synaptic input to motor units is a potential mechanism for altered force steadiness when a cognitive challenge is imposed during low-force contractions in young women and old adults

    Translocation t(7;9)(q34;q32) found in pediatric T-cell acute lymphoblastic leukemia

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    Case report of a translocation : Translocation t(7;9)(q34;q32) found in pediatric T-cell acute lymphoblastic leukemia

    An analysis-ready and quality controlled resource for pediatric brain white-matter research

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    We created a set of resources to enable research based on openly-available diffusion MRI (dMRI) data from the Healthy Brain Network (HBN) study. First, we curated the HBN dMRI data (N = 2747) into the Brain Imaging Data Structure and preprocessed it according to best-practices, including denoising and correcting for motion effects, susceptibility-related distortions, and eddy currents. Preprocessed, analysis-ready data was made openly available. Data quality plays a key role in the analysis of dMRI. To optimize QC and scale it to this large dataset, we trained a neural network through the combination of a small data subset scored by experts and a larger set scored by community scientists. The network performs QC highly concordant with that of experts on a held out set (ROC-AUC = 0.947). A further analysis of the neural network demonstrates that it relies on image features with relevance to QC. Altogether, this work both delivers resources to advance transdiagnostic research in brain connectivity and pediatric mental health, and establishes a novel paradigm for automated QC of large datasets

    Systematic Conservation Planning in the Face of Climate Change: Bet-Hedging on the Columbia Plateau

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    Systematic conservation planning efforts typically focus on protecting current patterns of biodiversity. Climate change is poised to shift species distributions, reshuffle communities, and alter ecosystem functioning. In such a dynamic environment, lands selected to protect today's biodiversity may fail to do so in the future. One proposed approach to designing reserve networks that are robust to climate change involves protecting the diversity of abiotic conditions that in part determine species distributions and ecological processes. A set of abiotically diverse areas will likely support a diversity of ecological systems both today and into the future, although those two sets of systems might be dramatically different. Here, we demonstrate a conservation planning approach based on representing unique combinations of abiotic factors. We prioritize sites that represent the diversity of soils, topographies, and current climates of the Columbia Plateau. We then compare these sites to sites prioritized to protect current biodiversity. This comparison highlights places that are important for protecting both today's biodiversity and the diversity of abiotic factors that will likely determine biodiversity patterns in the future. It also highlights places where a reserve network designed solely to protect today's biodiversity would fail to capture the diversity of abiotic conditions and where such a network could be augmented to be more robust to climate-change impacts

    A survey of the hybridisation status of Cervus deer species on the island of Ireland

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    Red deer (Cervus elaphus) did not recolonise Ireland after the last glaciation, but the population in Co. Kerry is descended from an ancient (c. 5000 BP) introduction and merits conservation. During the mid-19th century exotic species including North American wapiti (C. canadensis) and Japanese sika deer (C. nippon nippon) were introduced to Ireland, mainly via Powerscourt Park, Co. Wicklow. While wapiti failed to establish, sika thrived, dispersed within Co. Wicklow and were translocated to other sites throughout Ireland. Red deer and sika are known to have hybridised in Ireland, particularly in Co. Wicklow, but an extensive survey with a large, highly diagnostic marker panel is required to assess the threat hybridisation potentially poses to the Co. Kerry red deer population. Here, 374 individuals were genotyped at a panel of 22 microsatellites and at a single mtDNA marker that are highly diagnostic for red deer and Japanese sika. The microsatellites are also moderately diagnostic for red deer and wapiti. Wapiti introgression was very low [trace evidence in 2 (0.53 %) individuals]. Despite long-standing sympatry of red deer and sika in the area, no red deer-sika hybrids were detected in Co. Kerry suggesting strong assortative mating by both species in this area. However, 80/197 (41 %) of deer sampled in Co. Wicklow and 7/15 (47 %) of deer sampled in Co. Cork were red-sika hybrids. Given their proximity and that hybrids are less likely to mate assortatively than pure individuals, the Co. Cork hybrids pose a threat to the Co. Kerry red deer.UK Natural Environment Research Council PhD studentshi

    Author Correction: An analysis-ready and quality controlled resource for pediatric brain white-matter research

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