373 research outputs found
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Functional variants of DOG1 control seed chilling responses and variation in seasonal life-history strategies in Arabidopsis thaliana.
The seasonal timing of seed germination determines a plant's realized environmental niche, and is important for adaptation to climate. The timing of seasonal germination depends on patterns of seed dormancy release or induction by cold and interacts with flowering-time variation to construct different seasonal life histories. To characterize the genetic basis and climatic associations of natural variation in seed chilling responses and associated life-history syndromes, we selected 559 fully sequenced accessions of the model annual species Arabidopsis thaliana from across a wide climate range and scored each for seed germination across a range of 13 cold stratification treatments, as well as the timing of flowering and senescence. Germination strategies varied continuously along 2 major axes: 1) Overall germination fraction and 2) induction vs. release of dormancy by cold. Natural variation in seed responses to chilling was correlated with flowering time and senescence to create a range of seasonal life-history syndromes. Genome-wide association identified several loci associated with natural variation in seed chilling responses, including a known functional polymorphism in the self-binding domain of the candidate gene DOG1. A phylogeny of DOG1 haplotypes revealed ancient divergence of these functional variants associated with periods of Pleistocene climate change, and Gradient Forest analysis showed that allele turnover of candidate SNPs was significantly associated with climate gradients. These results provide evidence that A. thaliana's germination niche and correlated life-history syndromes are shaped by past climate cycles, as well as local adaptation to contemporary climate
Recovery from Substance Abuse: The Role of Unsupportive Social Interactions
ABSTRACTRECOVERY FROM SUBSTANCE ABUSE: THE ROLE OF UNSUPPORTIVE SOCIAL INTERATIONSBy Michelle M. Schmitt, M.A., M.S. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University.Virginia Commonwealth University, 2003Major Director: Kathleen M. Ingram, Ph.D., Assistant Professor, Department of Psychology It has been estimated that over 20 million individuals struggle with substance abuse and/or dependence each year. Theories of addiction and recovery have long incorporated the notion of social support and helping relationships to facilitate adjustment. However, the literature investigating the role of social support is fraught with contradictions. In addition, in substance abusing populations, researchers have just begun to investigate social support as having negative, as well as positive implications. Historically with these populations, interpersonal conflict and loss of relationships were investigated as negative life events, rather than types of unsupportive social interactions. This study was designed to explore how positive and negative social relationships are associated with adjustment among individuals struggling with addiction. Ninety-seven individuals, who were currently participants in two Drug Court programs, completed measures of global positive social support (the 6-item Social Support Questionnaire), recovery-specific positive social support (Important People & Activities Instrument, brief version), recovery-specific unsupportive social interactions (Unsupportive Social Interactions Inventory), recovery-specific cognitive threat appraisals, and well-being (Situational Confidence Questionnaire and Center for Epidemiologic Studies Depression Scale). Information regarding treatment attendance and positive urine toxicology reports was gleaned from treatment records. Results suggested that global positive social support accounted for the greatest proportion of variance in the well-being outcomes of self-efficacy for recovery and depression. Global positive social support eclipsed the role of recovery-specific unsupportive social interactions in relation to well-being. However, recovery-specific unsupportive social interactions were found pertinent to this population. None of the survey variables were significantly related to treatment attendance, and only self-efficacy for recovery was related to continued drug use (urine toxicology screenings). Implications for future research and interventions to enhance the well-being of individuals in recovery are discussed
Investigating German Higher Education Institutions\u27 Transfer Activities: New Measurements Based on Web Mining
In recent years, higher education institutions (HEI) have expanded their involvement in diverse transfer activities (TA), extending beyond traditional teaching and research roles. These TA are often heterogeneous and informal, which makes measuring their full scope and effects challenging. In this article, we propose a new and straightforward to implement approach for mastering this task. In a first step, we theoretically derive three different dimensions of transfer, namely the transfer of knowledge, technology and personnel. For each of these categories, we develop an artificial intelligence (AI) optimized keyword list. Finally, we use these lists and apply web mining techniques and natural language processing (NLP) to measure TA from German HEI. To this end, we analyze a total of 299,229 texts from 376 German HEI websites. Our study shows that our proposed approach represents an effective and valuable tool for measuring TA from HEI and provides a foundation for further research
Mind Your Meds: Safe Opioid Disposal Awareness
Driven by the effects of the opioid epidemic on friends, family members, students, and patients, members of the 2019 GEHLI Team “Mission Possible” are dedicated to bolstering educational awareness of safe leftover opioid disposal methods to decrease the supply of opioids in our community. On average, over 2/3 of opioid prescription medications are leftover and lead to later misuse or abuse (JAMA Survey). Despite a decrease in prescription writing for pain medication over the years, the mortality rate from overdose, and the rate of infants born to mothers with opioid abuse continues to steadily increase in Virginia (VDH). Team Mission Possible seeks to promote awareness of both the need and resources available for safe opioid disposal by educating prescribers in the VCU Health system and spreading knowledge to VCU patients, students, faculty, staff, and members of the surrounding community through: educational events on the Monroe Park and Medical campuses; teaming up with Miss Virginia’s “Mind your Meds campaign”; live Facebook interviews; and educational flyers
Research priorities in cardiovascular imaging.
AIM: A modified Delphi approach was used to develop consensus opinion among British Society for Cardiac Imaging/British Society of Cardiac CT (BSCI/BSCCT) members in order to prioritise research questions in cardiovascular imaging. METHODS: All members of the BSCI/BSCCT were invited to submit research questions that they considered to be of the highest clinical and/or academic priority in the field of cardiovascular imaging (phase 1). Subsequently a steering committee removed duplicate questions and combined questions of a similar theme by consensus agreement where appropriate. BSCI/BSCCT members were invited to rank the resulting research questions in two further iterative rounds (phases 2 and 3) to determine a final list of high-priority research questions. RESULTS: A total of 111 research questions were submitted in phase 1 by 30 BSCI/BSCCT members. While there was a broad range of topics, from determining the optimal features/markers of the vulnerable plaque to investigating how cardiac imaging can best be used to maximise clinical outcomes and economic costs, multimodality imaging-related (n=44, 40%) questions dominated the categories and coronary artery imaging (n=40, 36%) was the most common topic. Over two iterative rounds of prioritisation of these research questions, the original 111 were reduced to 75 questions in round 2, and 25 in round 3. From these 25 a final Top 10 list was distilled by consensus grouping. CONCLUSION: This study has identified and ranked the top research priorities in cardiovascular imaging, as identified by the BSCI/BSCCT membership. This is a first step towards identifying the cardiovascular imaging research priorities within the UK and may assist researchers and funding bodies alike in setting priorities
From Anecdotal Evidence to Quantitative Evaluation Methods:A Systematic Review on Evaluating Explainable AI
The rising popularity of explainable artificial intelligence (XAI) to
understand high-performing black boxes, also raised the question of how to
evaluate explanations of machine learning (ML) models. While interpretability
and explainability are often presented as a subjectively validated binary
property, we consider it a multi-faceted concept. We identify 12 conceptual
properties, such as Compactness and Correctness, that should be evaluated for
comprehensively assessing the quality of an explanation. Our so-called Co-12
properties serve as categorization scheme for systematically reviewing the
evaluation practice of more than 300 papers published in the last 7 years at
major AI and ML conferences that introduce an XAI method. We find that 1 in 3
papers evaluate exclusively with anecdotal evidence, and 1 in 5 papers evaluate
with users. We also contribute to the call for objective, quantifiable
evaluation methods by presenting an extensive overview of quantitative XAI
evaluation methods. This systematic collection of evaluation methods provides
researchers and practitioners with concrete tools to thoroughly validate,
benchmark and compare new and existing XAI methods. This also opens up
opportunities to include quantitative metrics as optimization criteria during
model training in order to optimize for accuracy and interpretability
simultaneously.Comment: Link to website added: https://utwente-dmb.github.io/xai-papers
Sex Differences in the Frequencies of B and T Cell Subpopulations of Human Cord Blood
Cord blood represents a link between intrauterine and early extrauterine development.
Cord blood cells map an important time frame in human immune imprinting processes. It is unknown
whether the sex of the newborn affects the lymphocyte subpopulations in the cord blood. Nine B and
twenty-one T cell subpopulations were characterized using flow cytometry in human cord blood from
sixteen male and twenty-one female newborns, respectively. Except for transitional B cells and naïve
B cells, frequencies of B cell counts across all subsets was higher in the cord blood of male newborns
than in female newborns. The frequency of naïve thymus-negative Th cells was significantly higher
in male cord blood, whereas the remaining T cell subpopulations showed a higher count in the
cord blood of female newborns. Our study is the first revealing sex differences in the B and T cell
subpopulations of human cord blood. These results indicate that sex might have a higher impact for
the developing immune system, urging the need to expand research in this area
Caveolin 1 is overexpressed and amplified in a subset of basal-like and metaplastic breast carcinomas: a morphologic, ultrastructural, immunohistochemical, and in situ hybridization analysis
The distribution and significance of caveolin 1 (CAV1) expression in different breast cell types and role in breast carcinogenesis remain poorly understood. Both tumor-suppressive and oncogenic roles have been proposed for this protein. The aims of this study were to characterize the distribution of CAV1 in normal breast, benign breast lesions, breast cancer precursors, and metaplastic breast carcinomas; to assess the prognostic significance of CAV1 expression in invasive breast carcinomas; and to define whether CAV1 gene amplification is the underlying genetic mechanism driving CAV1 overexpression in breast carcinomas. Purpose: The distribution and significance of caveolin 1 (CAV1) expression in different breast cell types and role in breast carcinogenesis remain poorly understood. Both tumor-suppressive and oncogenic roles have been proposed for this protein. The aims of this study were to characterize the distribution of CAV1 in normal breast, benign breast lesions, breast cancer precursors, and metaplastic breast carcinomas; to assess the prognostic significance of CAV1 expression in invasive breast carcinomas; and to define whether CAV1 gene amplification is the underlying genetic mechanism driving CAV1 overexpression in breast carcinomas.
Experimental Design: CAV1 distribution in frozen and paraffin-embedded whole tissue sections of normal breast was evaluated using immunohistochemistry, immunofluorescence, and immunoelectron microscopy. CAV1 expression was immunohistochemically analyzed in benign lesions, breast cancer precursors, and metaplastic breast carcinomas and in a cohort of 245 invasive breast carcinomas from patients treated with surgery followed by anthracycline-based chemotherapy. In 25 cases, CAV1 gene amplification was assessed by chromogenic in situ hybridization.
Results: In normal breast, CAV1 was expressed in myoepithelial cells, endothelial cells, and a subset of fibroblasts. Luminal epithelial cells showed negligible staining. CAV1 was expressed in 90% of 39 metaplastic breast carcinomas and in 9.4% of 245 invasive breast cancers. In the later cohort, CAV1 expression was significantly associated with ‘basal-like’ immunophenotype and with shorter disease-free and overall survival on univariate analysis. CAV1 gene amplification was found in 13% of cases with strong CAV1 expression.
Conclusions: The concurrent CAV1 amplification and overexpression call into question its tumor-suppressive effects in basal-like breast carcinomas
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