3,044 research outputs found

    Generic and customised digital image enhancement filters for the visually impaired

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    AbstractThis study compares the effectiveness of various image enhancement filters for improving the perceived visibility of coloured digital natural images for people with visual impairment. Generic filters were compared with Peli’s adaptive enhancement and adaptive thresholding and custom-devised filters based on each subject’s contrast sensitivity loss. Subjects with low vision made within filter rankings followed by between filter ratings. In general, subjects preferred filters with lower gains. Unsharp masking resulted in a significant increase in perceived visibility for some image types (p⩽0.05) while Peli’s adaptive enhancement, edge enhancement and histogram equalization resulted in borderline improvements. Adaptive thresholding and the custom devised filter did not result in overall improvements in perceived visibility

    College transition Fall 2020 and 2021: Understanding the relationship of COVID-19 experiences and psychosocial correlates with anxiety and depression

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    Rates of mental health symptoms, particularly anxiety and depression, have increased significantly in college students in the past decade along with utilization of mental health resources. The COVID-19 pandemic created an additional source of stressors to an already challenging landscape of college transition. COVID-19 has been associated with an increase of anxiety among college students, particularly first year students, entering college in Fall 2020. The shifts in policy (e.g., federal, state, and college) accruing medical data, and vaccine availability between Fall 2020 and Fall 2021 provide an opportunity to examine the role of COVID-19 experiences in the transition to college for these two first-year student cohorts. This study examined two cohorts of first-year students, Fall 2020 and 2021, to better understand the relationship between COVID-19 experiences, psychosocial correlates, and mental health symptoms. Results suggest that for students in our Fall 2020 cohort COVID-19 experiences played a distinct role in the prediction of mental health symptoms while in Fall 2021 COVID-19 experiences did not uniquely contribute to prediction of mental health symptoms. These findings have implications for mental health interventions for first-year students transitioning to college

    BDNF Val66Met Polymorphism Influences Age Differences in Microstructure of the Corpus Callosum

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    Brain-derived neurotrophic factor (BDNF) plays an important role in neuroplasticity and promotes axonal growth, but its secretion, regulated by a BDNF gene, declines with age. The low-activity (met) allele of common polymorphism BDNF val66met is associated with reduced production of BDNF. We examined whether age-related reduction in the integrity of cerebral white matter (WM) depends on the BDNF val66met genotype. Forty-one middle-aged and older adults participated in the study. Regional WM integrity was assessed by fractional anisotropy (FA) computed from manually drawn regions of interest in the genu and splenium of the corpus callosum on diffusion tensor imaging scans. After controlling for effects of sex and hypertension, we found that only the BDNF 66met carriers displayed age-related declines in the splenium FA, whereas no age-related declines were shown by BDNF val homozygotes. No genotype-related differences were observed in the genu of the corpus callosum. This finding is consistent with a view that genetic risk for reduced BDNF affects posterior regions that otherwise are considered relatively insensitive to normal aging. Those individuals with a genetic predisposition for decreased BDNF expression may not be able to fully benefit from BDNF-based plasticity and repair mechanisms

    Requirement for sphingosine kinase 1 in mediating phase 1 of the hypotensive response to anandamide in the anaesthetised mouse

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    In the isolated rat carotid artery, the endocannabinoid anandamide induces endothelium-dependent relaxation via activation of the enzyme sphingosine kinase (SK). This generates sphingosine-1-phosphate (S1P) which can be released from the cell and activates S1P receptors on the endothelium. In anaesthetised mice, anandamide has a well-characterised triphasic effect on blood pressure but the contribution of SK and S1P receptors in mediating changes in blood pressure has never been studied. Therefore, we assessed this in the current study. The peak hypotensive response to 1 and 10 mg/kg anandamide was measured in control C57BL/6 mice and in mice pretreated with selective inhibitors of SK1 (BML-258, also known as SK1-I) or SK2 ((R)-FTY720 methylether (ROMe), a dual SK1/2 inhibitor (SKi) or an S1P1 receptor antagonist (W146). Vasodilator responses to S1P were also studied in isolated mouse aortic rings. The hypotensive response to anandamide was significantly attenuated by BML-258 but not by ROMe. Antagonising S1P1 receptors with W146 completely blocked the fall in systolic but not diastolic blood pressure in response to anandamide. S1P induced vasodilation in denuded aortic rings was blocked by W146 but caused no vasodilation in endothelium-intact rings. This study provides evidence that the SK1/S1P regulatory-axis is necessary for the rapid hypotension induced by anandamide. Generation of S1P in response to anandamide likely activates S1P1 to reduce total peripheral resistance and lower mean arterial pressure. These findings have important implications in our understanding of the hypotensive and cardiovascular actions of cannabinoids

    High-throughput sequencing for community analysis: the promise of DNA barcoding to uncover diversity, relatedness, abundances and interactions in spider communities

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    Large-scale studies on community ecology are highly desirable but often difficult to accomplish due to the considerable investment of time, labor and, money required to characterize richness, abundance, relatedness, and interactions. Nonetheless, such large-scale perspectives are necessary for understanding the composition, dynamics, and resilience of biological communities. Small invertebrates play a central role in ecosystems, occupying critical positions in the food web and performing a broad variety of ecological functions. However, it has been particularly difficult to adequately characterize communities of these animals because of their exceptionally high diversity and abundance. Spiders in particular fulfill key roles as both predator and prey in terrestrial food webs and are hence an important focus of ecological studies. In recent years, large-scale community analyses have benefitted tremendously from advances in DNA barcoding technology. High-throughput sequencing (HTS), particularly DNA metabarcoding, enables community-wide analyses of diversity and interactions at unprecedented scales and at a fraction of the cost that was previously possible. Here, we review the current state of the application of these technologies to the analysis of spider communities. We discuss amplicon-based DNA barcoding and metabarcoding for the analysis of community diversity and molecular gut content analysis for assessing predator-prey relationships. We also highlight applications of the third generation sequencing technology for long read and portable DNA barcoding. We then address the development of theoretical frameworks for community-level studies, and finally highlight critical gaps and future directions for DNA analysis of spider communities

    Novel Approach to Mass Tort Class Actions: The Billion Dollar Settlement in the Sulzer Artificial Hip and Knee Litigation: A Symposium

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    This is a transcript of a two hour symposium which deals with the Sulzer knee and hip replacement class action. A copy of the settlement is included as an appendix. The settlement in the U.S. District Court for the N.D. Ohio was unique and creative approach to resolving a mass tort class action. In a novel move, Sulzer agreed to open its books to an independent review firm to determine how much the firm could pay without going bankrupt. The number was $1 billion. As negotiated by the parties and approved by the court, the final settlement provides compensation for each member of the class based on a variety of factors, such as whether the member has undergone - or is likely to undergo - a revision to replace the defective part. Professor Susan Becker made the introductory remarks. The panel members were all involved in the Sulzer knee and hip replacement class action. R. Eric Kennedy served as lead plaintiffs\u27 counsel. The Honorable Kathleen McDonald O\u27Malley of the U.S. District Court for the Northern District of Ohio presided over the Sulzer class action litigation and settlement. Sidney A. Backstrom and Richard F. Scruggs were the defense counsel. James J. McMonagle served as the Claims Administrator overseeing distribution of the Sulzer class action settlement funds

    Novel Approach to Mass Tort Class Actions: The Billion Dollar Settlement in the Sulzer Artificial Hip and Knee Litigation: A Symposium

    Get PDF
    This is a transcript of a two hour symposium which deals with the Sulzer knee and hip replacement class action. A copy of the settlement is included as an appendix. The settlement in the U.S. District Court for the N.D. Ohio was unique and creative approach to resolving a mass tort class action. In a novel move, Sulzer agreed to open its books to an independent review firm to determine how much the firm could pay without going bankrupt. The number was $1 billion. As negotiated by the parties and approved by the court, the final settlement provides compensation for each member of the class based on a variety of factors, such as whether the member has undergone - or is likely to undergo - a revision to replace the defective part. Professor Susan Becker made the introductory remarks. The panel members were all involved in the Sulzer knee and hip replacement class action. R. Eric Kennedy served as lead plaintiffs\u27 counsel. The Honorable Kathleen McDonald O\u27Malley of the U.S. District Court for the Northern District of Ohio presided over the Sulzer class action litigation and settlement. Sidney A. Backstrom and Richard F. Scruggs were the defense counsel. James J. McMonagle served as the Claims Administrator overseeing distribution of the Sulzer class action settlement funds

    Planning for Adaptation to Climate Change: Lessons from the US National Wildlife Refuge System

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    US national wildlife refuges have recent, detailed management plans illustrating the state of planning for climate-change adaptation in protected areas. Discussion of and prescriptions for addressing climate change increased in refuge plans between 2005 and 2010 but decreased in 2011. The plans respond to some climate-change impacts on biodiversity and call for monitoring but with little clarity regarding how to act on monitoring results and scant attention to future changes in phenology and community composition. The threats posed by sea-level rise generated the best-developed plan prescriptions. Examples of excellent prescriptions provide models for future planning. Some decision-support tools, such as vulnerability assessments, will improve future planning as they become more available. However, research better targeted at management information gaps is also needed. Region-level coordination, such as through landscape conservation design, offers opportunities for enlarging conservation footprints and improving information generation and sharing
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