1,720,958 research outputs found

    Effects of CB2 Receptor Activation on Variable Chronic Mild Stress (CMS) Induced Depression and Hippocampal Dependant Spatial Learning

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    Major Depressive Disorder (MDD) accounts for approximately 10% of all diagnosed chronic illness in the United States. The most common treatments for MDD is serotonergic manipulation via pharmacological treatments such as monoamine oxidase inhibitors (MAO-I) or selective serotonin reuptake inhibitors (SSRI). However, not only have these treatments proven to be ineffective for a portion of the population, but they also fail to treat some of the physiological damages that occur in the hippocampus during MDD due to over-activation of inflammatory cells known as microglia. Activation of the CB2 receptor in the hippocampus has been shown to inhibit microglial cells and promote neuron proliferation. This study investigates the effects of the CB2 agonist GW405833 on rats in the chronic mild stress model for depression. Results showed significant decrease in depressive-like behavior in the Forced Swim Test, the Open Field Test for anxiety and the Morris Water Maze. Sucrose Preference testing and weight gain did not differ significantly. Immunohistochemical staining for activated microglial cells and neuron nuclei was performed. The data suggest that CB2 activation could play an important role in MDD treatment for both behavioral and physical changes occurring in the brain

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    Myelin and glial pathology in aging and congnitive decline: evidence for faulty myelin clearance in the rhesus monkey

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    Aging is associated with a loss of cognitive function related to learning, memory, and executive function with varying severity. Although there is no age-related loss of neurons in healthy aging, myelin damage accumulates and is associated with cognitive decline. The brain’s resident macrophages, microglia, are responsible for clearing damaged myelin and promoting subsequent oligodendrocyte-mediated remyelination. To test the hypothesis that age-related dysfunction of microglial phagocytosis and oligodendrocyte remyelination capacity contributes to myelin pathology and cognitive impairment. To test this, rhesus monkeys from across the lifespan (7-30 years of age) were tested in three specific aims. 1) To characterize gene expression of myelin basic protein (MBP) in the brain and clearance of MBP to the cerebrospinal fluid (CSF) in relation to age-related myelin pathology. The density of myelinated axons visualized using label-free spectral confocal reflectance imaging did not correlate with age, but was significantly lower in aged animals with cognitive impairment. Next, MBP gene expression was measured using qPCR in the dorsal prefrontal cortex along with quantification of MBP protein levels in the CSF using ELISA. Age-dependent increases of MBP gene expression in the brain and MBP protein levels in the CSF were observed. Interestingly, MBP levels in the CSF were lower in animals with cognitive impairment. 2) To test the hypothesis that microglia would become increasingly primed for phagocytosis with age-related myelin pathology. The number of microglia immunostained with galectin-3, a marker for phagocytic activation, was quantified in the frontal white matter and increases in both aging and cognitive decline were detected. 3) To evaluate the hypothesis that lipofuscin, an age-related accumulation indicative of autophagic dysfunction, would accumulate and impair glial cells of the white matter in aged animals. Lipofuscin accumulation was increased with age in the frontal white matter and the size of lipofuscin clusters was associated with cognitive impairment. Lipofuscin was found primarily in microglia and oligodendrocytes, but not in astrocytes. These data suggest that lipofuscin burden in microglia and oligodendrocytes inhibits their homeostatic functions resulting in improper myelin clearance and turnover, leading to a devastating feed-forward cycle of myelin damage that contributes to age-related cognitive impairment

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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