2,445 research outputs found

    Continuous Theta Rhythm During Spatial Working Memory Task in Rodent Models of Streptozotocin-induced Type 2 Diabetes

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    Alzheimer’s disease is a neurodegenerative disorder altering memory loss thought to be due to neuropathological symptoms such as the buildup of beta amyloid plaques (Ab) and neurofibrillary tangles (NFT). The etiology of Alzheimer’s is still unknown; however, potential risk factors such as diabetes may lead to its development. The most common form of diabetes is type 2 diabetes known for persistent insulin resistance leading to a state of hyperglycemia. Insulin resistance has been shown to affect cognitive abilities such as learning, memory and also alters synaptic plasticity. Neural connections between the hippocampus (HC) and anterior cingulate cortex (ACC) are known to be very important for learning and memory and are highly plastic, making them an intriguing target that could be altered by hyperglycemia. We hypothesize that hyperglycemic rodents will exhibit spatial memory deficits that may be associated with cognitively linked interactions between the HC and ACC. Minimal doses of streptozotocin (STZ), which is toxic to insulin producing beta cells, were given for 9-10 weeks. Using a spatial working memory task known as delayed alternation we found significant differences between control and experimental rats in working memory accuracy. This task places strong working memory demands on subjects which may be compromised by a hyperglycemic state. We measured EEG recordings from the HC and ACC during task performance and found that hyperglycemic rats had nearly continuous theta rhythm during the 30-minute session. Control rats however, displayed normal transitions between theta and lower frequency delta. Neural connectivity may be altered due to a change in frequency activity between the HC and ACC due to diabetes which is a risk factor in the development of AD impairments. These results show that hyperglycemia leads to changes along the circuit critical for learning and memory

    The impact of strictly protected areas in a deforestation hotspot

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    Protected areas are often thought of as a key conservation strategy for avoiding deforestation and retaining biodiversity; therefore, it is crucial to know how effective they are at achieving this purpose. Using a case study from Queensland, Australia, we identified and controlled for bias in allocating strictly protected areas (IUCN Class I and II) and evaluated their impact (in terms of avoiding deforestation) using statistical matching methods. Over the 30 years between 1988 and 2018, approximately 70,481 km2 of native forest was cleared in the study region. Using statistical matching, we estimated that 10.5% (1,447 km2) of Category I and II (strict) protected areas would have been cleared in the absence of protection. Put differently, 89.5% of strictly protected areas are unlikely to have been cleared, even if they were never protected. While previous studies have used statistical matching at a country or state level, we conducted an analysis that allows regional comparison across a single State. Our research indicates that strictly protected areas are marginally effective at preventing deforestation, and this likely due to biases in establishing protected areas on unproductive land

    Updated Genes, Lifestyles, and their Interactions for Human Longevity

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    Healthy aging is the prolonging of optimal wellbeing during the progressive decline in physiological functions that are necessary for survival. Two important components of aging include an individual’s genetic makeup and lifestyle choices such as diet and exercise. Genetic factors are responsible for the functional physiology of the body including cell maintenance, metabolism and apoptosis. The individual effects of genes and lifestyle choices on aging are reported mainly in Caucasian populations, with very limited studies in minority populations. In this review, we included the effects of genes and environment and the interaction between them on aging in Hispanic population in addition to other populations. Our systematic review focuses on exploring present findings that assess the involvement of genes and lifestyles with healthy aging, as well as the interactions between the two. The purpose of the review is to update current findings of longevity as it pertains to the genetic composition of humans and the lifestyle choices people make. We were specifically looking for research conducted in the US Hispanic population and/or other minority populations. We searched through PubMed to identify reliable and relevant research articles involving ‘genes’, ‘lifestyle’, ‘longevity’, and ‘healthy aging’. We filtered the articles for those that pertain towards humans and are in the English language. We searched most updated top longevity-associated genes, lifestyles, and their interactions. We found that the biological and environmental factors (e.g., lifestyle) involved in aging are important factors that attribute towards attainment of longevity. The individual’s genetic composition and lifestyle choices significantly impact the aging process and longevity

    Mixed Valvular Disease Following Transcatheter Aortic Valve Replacement: Quantification and Systematic Differentiation Using Clinical Measurements and Image-Based Patient‐Specific In Silico Modeling

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    Background: Mixed valvular disease (MVD), mitral regurgitation (MR) from pre‐existing disease in conjunction with paravalvular leak (PVL) following transcatheter aortic valve replacement (TAVR), is one of the most important stimuli for left ventricle (LV) dysfunction, associated with cardiac mortality. Despite the prevalence of MVD, the quantitative understanding of the interplay between pre‐existing MVD, PVL, LV, and post‐TAVR recovery is meager. Methods and Results: We quantified the effects of MVD on valvular‐ventricular hemodynamics using an image‐based patient‐specific computational framework in 72 MVD patients. Doppler pressure was reduced by TAVR (mean, 77%; N=72; P<0.05), but it was not always accompanied by improvements in LV workload. TAVR had no effect on LV workload in 22 patients, and LV workload post‐TAVR significantly rose in 32 other patients. TAVR reduced LV workload in only 18 patients (25%). PVL significantly alters LV flow and increases shear stress on transcatheter aortic valve leaflets. It interacts with mitral inflow and elevates shear stresses on mitral valve and is one of the main contributors in worsening of MR post‐TAVR. MR worsened in 32 patients post‐TAVR and did not improve in 18 other patients. Conclusions: PVL limits the benefit of TAVR by increasing LV load and worsening of MR and heart failure. Post‐TAVR, most MVD patients (75% of N=72; P<0.05) showed no improvements or even worsening of LV workload, whereas the majority of patients with PVL, but without that pre‐existing MR condition (60% of N=48; P<0.05), showed improvements in LV workload. MR and its exacerbation by PVL may hinder the success of TAVR

    Student Knowledge of Signs, Risk Factors, and Resources for Depression, Anxiety, Sleep Disorders, and Other Mental Health Problems on Campus

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    A mixed methods study sought to assess student knowledge of signs, risk factors, and campus services available for mental health disorders. A survey was completed by 831 students and three focus groups were conducted. Respondents felt more knowledgeable about depression than about anxiety and sleep disorders. Graduate students and seniors had a keener awareness of risk factors for anxiety and sophomores were in the greatest danger of failing to recognize these risks. Males often failed to recognize signs and risk factors for mental health problems. Support groups, courses, and workshops on managing relationships, transition to college, and specific mental health disorders are advocated

    Ecological constraint mapping: understanding uutcome-limiting bottlenecks for improved environmental decision-making in marine and coastal environments

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    Despite genuine attempts, the history of marine and coastal ecosystem management is littered with examples of poor environmental, social and financial outcomes. Marine ecosystems are largely populated by species with open populations, and feature ecological processes that are driven by multiple, interwoven, dynamic causes and effects. This complexity limits the acquisition of relevant knowledge of habitat characteristics, species utilisation and ecosystem dynamics. The consequence of this lack of knowledge is uncertainty about the link between action taken and outcome achieved. Such uncertainty risks misdirected human and financial investment, and sometimes may even lead to perverse outcomes. Technological advances offer new data acquisition opportunities, but the diversity and complexity of the biological and ecological information needed to reduce uncertainty means the increase in knowledge will be slow unless it is undertaken in a structured and focussed way. We introduce “Ecological Constraint Mapping” – an approach that takes a “supply chain” point of view and focusses on identifying the principal factors that constrain life-history outcomes (success/productivity/resilience/fitness) for marine and coastal species, and ultimately the quality and resilience of the ecosystems they are components of, and the life-history supporting processes and values ecosystems provide. By providing a framework for the efficient development of actionable knowledge, Ecological Constraint Mapping can facilitate a move from paradigm-based to knowledge-informed decision-making on ecological issues. It is suitable for developing optimal solutions to a wide range of conservation and management problems, providing an organised framework that aligns with current perspectives on the complex nature of marine and coastal systems

    Sexual Orientation/Gender Identity, Socioeconomic Status, and Health across the Life Course (SOGI-SES) User Guide: Study Overview

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    The Sexual Orientation/Gender Identity, Socioeconomic Status, and Health across the Life Course Study (SOGI-SES) collected new survey data to support exploration of the relationships among sexual orientation, gender identity, gender expression, same-sex romantic and sexual behaviors, socioeconomic status, and health. The study was designed and conducted under the direction of the co-PIs, Carolyn T. Halpern from the Carolina Population Center (CPC) at the University of North Carolina at Chapel Hill and Kerith J. Conron from the Williams Institute at the University of California Los Angeles (UCLA). SOGI-SES is funded by a grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institute on Minority Health and Health Disparities (Grant numbers: 1R01HD087365 and R01 HD087365-03S1)

    Rapid Quantification of Dynamic and Spall Strength of Metals Across Strain Rates

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    The response of metals and their microstructures under extreme dynamic conditions can be markedly different from that under quasistatic conditions. Traditionally, high strain rates and shock stresses are measured using cumbersome and expensive methods such as the Kolsky bar or large spall experiments. These methods are low throughput and do not facilitate high-fidelity microstructure-property linkages. In this work, we combine two powerful small-scale testing methods, custom nanoindentation, and laser-driven micro-flyer shock, to measure the dynamic and spall strength of metals. The nanoindentation system is configured to test samples from quasistatic to dynamic strain rate regimes (103^{-3} s1^{-1} to 10+4^{+4} s1^{-1}). The laser-driven micro-flyer shock system can test samples through impact loading between 10+5^{+5} s1^{-1} to 10+7^{+7} s1^{-1} strain rates, triggering spall failure. The model material used for testing is Magnesium alloys, which are lightweight, possess high-specific strengths and have historically been challenging to design and strengthen due to their mechanical anisotropy. Here, we modulate their microstructure by adding or removing precipitates to demonstrate interesting upticks in strain rate sensitivity and evolution of dynamic strength. At high shock loading rates, we unravel an interesting paradigm where the spall strength of these materials converges, but the failure mechanisms are markedly different. Peak aging, considered to be a standard method to strengthen metallic alloys, causes catastrophic failure, faring much worse than solutionized alloys. Our high throughput testing framework not only quantifies strength but also teases out unexplored failure mechanisms at extreme strain rates, providing valuable insights for the rapid design and improvement of metals for extreme environments

    A Cohort Study of the Milk Microbiota of Healthy and Inflamed Bovine Mammary Glands From Dryoff Through 150 Days in Milk

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    The objective of this longitudinal cohort study was to describe the milk microbiota of dairy cow mammary glands based on inflammation status before and after the dry period. Individual mammary quarters were assigned to cohorts based on culture results and somatic cell count (SCC) at dryoff and twice in the first 2 weeks post-calving. Mammary glands that were microbiologically negative and had low SCC (&lt; 100,000 cells/mL) at all 3 sampling periods were classified as Healthy (n = 80). Microbiologically negative mammary glands that had SCC ≥150,000 cells/mL at dryoff and the first post-calving sample were classified as Chronic Culture-Negative Inflammation (CHRON; n = 17). Quarters that did not have both culture-negative milk and SCC ≥ 150,000 cells/mL at dryoff but were culture-negative with SCC ≥ 150,000 at both post-calving sampling periods were classified as Culture-Negative New Inflammation (NEWINF; n = 6). Mammary glands with bacterial growth and SCC ≥ 150,000 cells/mL at all 3 periods were classified as Positive (POS; n = 3). Milk samples were collected from all enrolled quarters until 150 days in milk and subjected to microbiota analysis. Milk samples underwent total DNA extraction, a 40-cycle PCR to amplify the V4 region of the bacterial 16S rRNA gene, and next-generation sequencing. Healthy quarters had the lowest rate of PCR and sequencing success (53, 67, 83, and 67% for Healthy, CHRON, NEWINF, and POS, respectively). Chao richness was greatest in milk collected from Healthy quarters and Shannon diversity was greater in milk from Healthy and CHRON quarters than in milk collected from glands in the NEWINF or POS cohorts. Regardless of cohort, season was associated with both richness and diversity, but stage of lactation was not. The most prevalent OTUs included typical gut- and skin-associated bacteria such as those in the phylum Bacteroidetes and the genera Enhydrobacter and Corynebacterium. The increased sequencing success in quarters with worse health outcomes, combined with the lack of bacterial growth in most samples and the high PCR cycle number required for amplification of bacterial DNA, suggests that the milk microbiota of culture-negative, healthy mammary glands is less abundant than that of culture-negative glands with a history of inflammation

    The Healthy Native Youth Implementation toolbox: Using Implementation Mapping to adapt an Online Decision Support System to Promote Culturally-Relevant Sexual Health Education For american indian and alaska Native Youth

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    BACKGROUND: American Indian and Alaska Native (AI/AN) youth experience serious disparities in sexual and reproductive health, including the highest teen birth rate among racial/ethnic groups, and disproportionate rates of sexually transmitted infections (STI), including HIV. A growing number of evidence-based programs (EBPs) that integrate the strengths and cultural teachings of Native communities exist. Yet, multiple factors, including lack of trained personnel, limited resources, and geographic isolation, may hinder their adoption and implementation. Innovative implementation strategies that facilitate the adoption and implementation of sexual health EBPs in Native communities may help reduce these disparities. METHODS: We applied Implementation Mapping, a systematic planning framework that utilizes theory, empirical evidence, and community input, to adapt a theory-based, online decision support system, iCHAMPSS (CHoosing And Maintaining Effective Programs for Sex Education in Schools), to support underlying dissemination and implementation processes unique to Native communities. We used an iterative design process, incorporating input from Native practitioners and academicians, to ensure that the adapted decision support system reflects cultural identification, community values, and experiences. RESULTS: Grounded in diffusion of innovations, organizational stage theory, and social cognitive theory, the CONCLUSION: There is a continued need to design, test, and evaluate D&I strategies that are relevant to Native communities. Th
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