694 research outputs found

    Cell-Type Specific Changes in Glial Morphology and Glucocorticoid Expression During Stress and Aging in the Medial Prefrontal Cortex.

    Get PDF
    Repeated exposure to stressors is known to produce large-scale remodeling of neurons within the prefrontal cortex (PFC). Recent work suggests stress-related forms of structural plasticity can interact with aging to drive distinct patterns of pyramidal cell morphological changes. However, little is known about how other cellular components within PFC might be affected by these challenges. Here, we examined the effects of stress exposure and aging on medial prefrontal cortical glial subpopulations. Interestingly, we found no changes in glial morphology with stress exposure but a profound morphological change with aging. Furthermore, we found an upregulation of non-nuclear glucocorticoid receptors (GR) with aging, while nuclear levels remained largely unaffected. Both changes are selective for microglia, with no stress or aging effect found in astrocytes. Lastly, we show that the changes found within microglia inversely correlated with the density of dendritic spines on layer III pyramidal cells. These findings suggest microglia play a selective role in synaptic health within the aging brain

    Evaluation of detailed aromatic mechanisms (MCMv3 and MCMv3.1) against environmental chamber data

    Get PDF
    International audienceA high quality dataset on the photo-oxidation of benzene, toluene, p-xylene and 1,3,5-trimethylbenzene has been obtained from experiments in the European Photoreactor (EUPHORE), a large outdoor environmental reaction chamber. The experiments were designed to test sensitive features of detailed aromatic mechanisms, and the dataset has been used to evaluate the performance of the Master Chemical Mechanism Version 3 (MCMv3). An updated version (MCMv3.1) was constructed based on recent experimental data, and details of its development are described in a companion paper. The MCMv3.1 aromatic mechanisms have also been evaluated using the EUPHORE dataset. Significant deficiencies have been identified in the mechanisms, in particular: 1) an over-estimation of the ozone concentration, 2) an under-estimation of the NO oxidation rate, 3) an under-estimation of OH. The use of MCMv3.1 improves the model-measurement agreement in some areas but significant discrepancies remain

    Chemically-Mediated Roostmate Recognition and Roost Selection by Brazilian Free-Tailed Bats (Tadarida brasiliensis)

    Get PDF
    BACKGROUND: The Brazilian free-tailed bat (Tadarida brasiliensis) is an exceptionally social and gregarious species of chiropteran known to roost in assemblages that can number in the millions. Chemical recognition of roostmates within these assemblages has not been extensively studied despite the fact that an ability to chemically recognize individuals could play an important role in forming and stabilizing complex suites of social interactions. METHODOLOGY/PRINCIPAL FINDINGS: Individual bats were given a choice between three roosting pouches: one permeated with the scent of a group of roostmates, one permeated with the scent of non-roostmates, and a clean control. Subjects rejected non-roostmate pouches with greater frequency than roostmate pouches or blank control pouches. Also, bats chose to roost in the roostmate scented pouches more often than the non-roostmate or control pouches. CONCLUSIONS/SIGNIFICANCE: We demonstrated that T. brasiliensis has the ability to chemically recognize roostmates from non-roostmates and a preference for roosting in areas occupied by roostmates. It is important to investigate these behaviors because of their potential importance in colony dynamics and roost choice

    Iodine monoxide at a clean marine coastal site: observations of high frequency variations and inhomogeneous distributions

    Get PDF
    The first in situ point observations of iodine monoxide (IO) at a clean marine site were made using a laser-induced fluorescence instrument deployed at Mace Head, Ireland in August 2007. IO mixing ratios of up to 49.8 pptv (equivalent to pmol mol<sup>−1</sup>; 1 s average) were observed at day-time low tide, well in excess of previous observed spatially-averaged maxima. A strong anti-correlation of IO mixing ratios with tide height was evident and the high time resolution of the observations showed IO peaked in the hour after low tide. The temporal delay in peak IO compared to low tide has not been observed previously but coincides with the time of peak aerosol number previously observed at Mace Head. <br><br> A long path-differential optical absorption spectroscopy instrument (with a 2 × 6.8 km folded path across Roundstone Bay) was also based at the site for 3 days during the point measurement observation period. Both instruments show similar temporal trends but the point measurements of IO are a factor of ~6–10 times greater than the spatially averaged IO mixing ratios, providing direct empirical evidence of the presence of inhomogeneities in the IO mixing ratio near the intertidal region

    Creating Information Resources and Trainings for Farmworker-Serving Community Health Workers

    Get PDF
    BACKGROUND: Farmworker-serving community health workers have limited access to farmworker health research findings, training, and education resources. With funding from the National Library of Medicine, we are working to improve the health information literacy of both community health workers and farmworkers. We conducted focus group discussions with community health workers to explore their experiences providing health education and information to farmworkers, their information-seeking behaviors, and their technology and information needs. Data from the focus groups provided insights into the main areas in which community health workers would like to receive professional development. CASE PRESENTATION: Our team, which includes health sciences librarians, developed a resource list of educational materials for farmworker health, videos to increase community health workers' skills finding health information online, and webinars to introduce these resources to community health workers. Videos, available in Spanish and English, included instruction on finding and evaluating online health information, accessing reputable online consumer health information sources, and advanced searching tips for Google and PubMed. Through three webinars, we introduced the resource list, videos, and design software for creating handouts and infographics to community health workers. CONCLUSIONS: Community health workers have a critical role in providing health education and information to farmworkers, and our efforts represent a first step in addressing community health workers' limited access to professional development. Health sciences librarians are well positioned to partner with interdisciplinary teams working to reduce health disparities and provide resources and training to community health workers, farmworkers, and other underserved communities

    Trees and urban air quality: a briefing note

    Get PDF
    Key messages 1. Trees alone are not the solution to air pollution. They can create a localised positive benefit for air quality by changing the dispersion of pollution, but the amount of pollution deposited onto trees is not significant on an urban scale. 2. Air pollution can damage trees. 3. Emissions of VOCs from trees can, under the correct conditions, create ozone pollution. This is only relevant when creating new woodlands
    • …
    corecore