316 research outputs found

    4-Methylcyclohexanemethanol Acute Toxicity to Daphnia and Its Effects on General Esterase and Glutathione S-Transferase Activity in Fathead Minnows

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    In 2014, 10,000 gallons of crude MCHM spilled into the Elk River in West Virginia. Due to a paucity of information about the toxicity of this chemical prior to the spill, our research aimed to verify the published 48-h EC50 for Daphnia magna (Daphnia) examine the effects of MCHM on two enzyme detoxification systems, general esterase and glutathione S-transferase, in Pimephales promelas (Fathead Minnow). We used pure MCHM instead of the crude form used in Eastman’s toxicity tests because the composition of crude MCHM is variable. The EC50 we obtained for pure MCHM did not differ significantly from the EC50 provided by Eastman for the crude form. We exposed Fathead Minnows to sublethal environmentally-relevant concentrations of MCHM for 96 h prior to performing the enzyme assays. The experimental groups in these assays did not show significant difference from control groups. Although our results add to the toxicity information, there is still a concerning deficit in chronic toxicity testing because of possible prolonged human exposure following the spill

    Archeota, Spring 2019

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    This is the Spring 2019 issue of Archeota, the official publication of SJSU SAASC. Archeota is a platform for students to contribute to the archival conversation. It is written BY students, FOR students. It provides substantive content on archival concerns and issues, and promotes career development in the field of archival studies. Archeota upholds the core values of the archival profession. It is a semiannual publication of the Student Chapter of the Society of American Archivists at the San Jose State University School of Information.https://scholarworks.sjsu.edu/saasc_archeota/1009/thumbnail.jp

    Investigating the Swimming of Microbial Pathogens Using Digital Holography.

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    To understand much of the behaviour of microbial pathogens, it is necessary to image living cells, their interactions with each other and with host cells. Species such as Escherichia coli are difficult subjects to image: they are typically microscopic, colourless and transparent. Traditional cell visualisation techniques such as fluorescent tagging or phase-contrast microscopy give excellent information on cell behaviour in two dimensions, but no information about cells moving in three dimensions. We review the use of digital holographic microscopy for three-dimensional imaging at high speeds, and demonstrate its use for capturing the shape and swimming behaviour of three important model pathogens: E. coli, Plasmodium spp. and Leishmania spp

    Altered fMRI Connectivity Dynamics in Temporal Lobe Epilepsy Might Explain Seizure Semiology

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    Temporal lobe epilepsy (TLE) can be conceptualized as a network disease. The network can be characterized by inter-regional functional connectivity, i.e., blood oxygen level-dependent (BOLD) signal correlations between any two regions. However, functional connectivity is not constant over time, thus computing correlation at a given time and then at some later time could give different results (non-stationarity). We hypothesized (1) that non-stationarities can be induced by epilepsy (e.g., interictal epileptic activity) increasing local signal variance and that (2) these transient events contribute to fluctuations in connectivity leading to pathological functioning, i.e., TLE semiology. We analyzed fMRI data from 27 patients with TLE and 22 healthy controls focusing on EEG-confirmed wake epochs only to protect against sleep-induced connectivity changes. Testing hypothesis (1), we identified brain regions where the BOLD signal variance was significantly greater in TLE than in controls: the temporal pole – including the hippocampus. Taking the latter as the seed region and testing hypothesis (2), we calculated the time-varying inter-regional correlation values (dynamic functional connectivity) to other brain regions and found greater connectivity variance in the TLE than the control group mainly in the precuneus, the supplementary and sensorimotor, and the frontal cortices. We conclude that the highest BOLD signal variance in the hippocampi is highly suggestive of a specific epilepsy-related effect. The altered connectivity dynamics in TLE patients might help to explain the hallmark semiological features of dyscognitive seizures including impaired consciousness (precuneus, frontal cortex), sensory disturbance, and motor automatisms (sensorimotor cortices, supplementary motor cortex). Accounting for the non-stationarity and state-dependence of functional connectivity are a prerequisite in the search for potential connectivity-derived biomarkers in TLE

    Understanding Family-Level Effects of Adult Chronic Disease Management Programs: Perceived Influences of Behavior Change on Adolescent Family Members' Health Behaviors Among Low-Income African Americans With Uncontrolled Hypertensions

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    Background: Despite improvements in cardiovascular disease (CVD) prevention and treatment, low-income African Americans experience disparities in CVD-related morbidity and mortality. Childhood obesity disparities and poor diet and physical activity behaviors contribute to CVD disparities throughout the life course. Given the potential for intergenerational transmission of CVD risk, it is important to determine whether adult disease management interventions could be modified to achieve family-level benefits and improve primary prevention among high-risk youth.Objective: To explore mechanisms by which African-American adults' (referred to as index patients) participation in a hypertension disease management trial influences adolescent family members' (referred to as adolescents) lifestyle behaviors.Design/Methods: The study recruited index patients from the Achieving blood pressure Control Together (ACT) study who reported living with an adolescent ages 12–17 years old. Index patients and adolescents were recruited for in-depth interviews and were asked about any family-level changes to diet and physical activity behaviors during or after participation in the ACT study. If family-level changes were described, index patients and adolescents were asked whether role modeling, changes in the home food environment, meal preparation, and family functioning contributed to these changes. These mechanisms were hypothesize to be important based on existing research suggesting that parental involvement in childhood obesity interventions influences child and adolescent weight status. Thematic content analysis of transcribed interviews identified both a priori and emergent themes.Results: Eleven index patients and their adolescents participated in in-depth interviews. Index patients and adolescents both described changes to the home food environment and meal preparation. Role modeling was salient to index patients, particularly regarding healthy eating behaviors. Changes in family functioning due to study participation were not endorsed by index patients or adolescents. Emergent themes included adolescent care-taking of index patients and varying perceptions by index patients of their influence on adolescents' health behaviors.Conclusions: Our findings suggest that disease management interventions directed at high-risk adult populations may influence adolescent family members' health behaviors. We find support for the hypotheses that role modeling and changes to the home food environment are mechanisms by which family-level health behavior change occurs. Adolescents' roles as caretakers for index patients emerged as another potential mechanism. Future research should explore these mechanisms and ways to leverage disease management to support both adult and adolescent health behavior change

    The effect of stress on the expression of the amyloid precursor protein in rat brain

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    AbstractThe abnormal processing of the amyloid precursor protein (APP) is a pivotal event in the development of the unique pathology that defines Alzheimer's disease (AD). Stress, and the associated increase in corticosteroids, appear to accelerate brain ageing and may increase vulnerability to Alzheimer's disease via altered APP processing. In this study, rats were repeatedly exposed to an unavoidable stressor, an open elevated platform. Previous studies in this laboratory have shown that a single exposure produces a marked increase in plasma corticosterone levels but animals develop tolerance to this effect between 10 and 20 daily sessions. Twenty-four hours after stress, there was an increase in the ratio of the deglycosylated form of APP in the particulate fraction of the brain, which subsequently habituated after 20 days. The levels of soluble APP (APPs) tended to be lower in the stress groups compared to controls except for a significant increase in the hippocampus after 20 days of platform exposure. Since APPs is reported to have neurotrophic properties, this increased release may represent a neuroprotective response to repeated stress. It is possible that the ability to mount this response decreases with age thus increasing the vulnerability to stress-induced AD-related pathology

    Evaluating Strategies For Reducing Health Disparities By Addressing The Social Determinants Of Health

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    Research reveals that the opportunities for healthy choices in homes, neighborhoods, schools, and workplaces can have decisive impacts on health. This article reviews scientific evidence from promising interventions focused on the social determinants of health, and describes ways in which they can improve population health and reduce health disparities. We show that there is sufficient evidence to support policy interventions targeted at education and early childhood; urban planning and community development; housing; income enhancements and supplements; and employment. When available, cost-effectiveness evaluations show that these interventions lead to long-term societal savings; however, more routine attention to cost considerations is needed for these interventions. We also discuss challenges to implementation, including the need for long-term financing in order to scale-up effective interventions for implementation at the local, state, or national level. Although we know enough to act, questions remain about how to optimally scale-up these interventions and maximize their benefits for the most vulnerable populations

    Maternal presence or absence alters nociceptive responding and cortical anandamide levels in juvenile female rats

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    The influence of parental support on child pain experiences is well recognised. Accordingly, animal studies have revealed both short- and long-term effects of early life stress on nociceptive responding and neural substrates such as endocannabinoids. The endocannabinoid system plays an important role in mediating and modulating stress, social interaction, and nociception. This study examined the effects of maternal support or acute isolation on nociceptive responding of female rats to a range of stimuli during the juvenile pre-adolescent period and accompanying changes in the endocannabinoid system. The data revealed that juvenile female Sprague Dawley rats (PND21-24) isolated from the dam for 1 hr prior to nociceptive testing exhibited increased latency to withdraw in the hot plate test and increased mechanical withdrawal threshold in the Von Frey test, compared to rats tested in the presence of the dam. Furthermore, isolated rats exhibited reduced latency to respond in the acetone drop test and enhanced nociceptive responding in the formalin test when compared to dam-paired counterparts. Anandamide, but not 2-AG, levels were reduced in the prefrontal cortex of dam-paired, but not isolated, juvenile rats following nociceptive testing. There was no change in the expression of CB1, FAAH or MAGL; however, CB2 receptor expression was reduced in both dam-paired and isolated rats following nociceptive testing. Taken together the data demonstrate that brief social isolation or the presence of the dam modulates nociceptive responding of juvenile rat pups in a modality specific manner, and suggest a possible role for the endocannabinoid system in the prefrontal cortex in sociobehavioural pain responses during early life

    Can vitamin D status influence the effect of stress on planning and problem-solving? A randomized control trial

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    Background: Nutritional interventions may serve as a stress resilience strategy with important implications for human health.Objective: The aim of this study was to investigate the effect of vitamin D supplementation throughout wintertime on problem-solving and planning abilities during stressful circumstances.Design: A total of 77 male inpatients with a mean age of 48 years (range 31–81) and stress-related mental health disorders were randomly assigned into a Vitamin D supplement group (daily intake of 40 μg) or a pla-cebo supplement group (Control) (daily intake of 120 mg olive oil). The intervention period was from January 2018 to May 2018. The means and standard deviations for vitamin D status (25-hydroxyvitamin D3, nmol/L), pre- and post-test, respectively, were 58(21) and 46(15) for the Control group, and 63(18) and 76(21) for the Vitamin D group. Problem-solving and planning abilities were measured by the Tower of London (ToL) task pre- (midwinter) and post- (spring) supplement intervention. The ToL task was performed during exposure to distracting noise.Results: The results revealed that vitamin D supplementation throughout the winter had a significant effect on number of correct responses on easier (1 and 2 move) ToL problems during stress; the Vitamin D group improved significantly from pre- to post-test, whereas the Control group did not. In addition, the Vitamin D group had significantly more correct responses than the Control group on post-test. The improved perfor-mance was not related to a speed-accuracy trade off effect; both groups showed significantly decreased plan-ning times from pre- to post-test. The intervention did not differentially affect task performance on the more difficult (3 to 5 move) ToL problems. For the more demanding problems, IQ seemed to explain most of the variance regarding accuracy. Age explained most of the variance associated with task planning time.Conclusion: Vitamin D supplementation seemed to improve resilience to stress, but it was limited to performance of easier tasks.publishedVersio
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