120 research outputs found

    Defect structures and torque on an elongated colloidal particle immersed in a liquid crystal host

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    Combining molecular dynamics and Monte Carlo simulation we study defect structures around an elongated colloidal particle embedded in a nematic liquid crystal host. By studying nematic ordering near the particle and the disclination core region we are able to examine the defect core structure and the difference between two simulation techniques. In addition, we also study the torque on a particle tilted with respect to the director, and modification of this torque when the particle is close to the cell wall

    GPR18 drives FAAH inhibition-induced neuroprotection against HIV-1 Tat-induced neurodegeneration

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    Human immunodeficiency virus type 1 (HIV-1) is known to provoke microglial immune responses which likely play a paramount role in the development of chronic neuroinflammatory conditions and neuronal damage related to HIV-1 associated neurocognitive disorders (HAND). In particular, HIV-1 Tat protein is a proinflammatory neurotoxin which predisposes neurons to synaptodendritic injury. Drugs targeting the degradative enzymes of endogenous cannabinoids have shown promise in reducing inflammation with minimal side effects in rodent models. Considering that markers of neuroinflammation can predict the extent of neuronal injury in HAND patients, we evaluated the neurotoxic effect of HIV-1 Tat-exposed microglia following blockade of fatty acid amid hydrolyze (FAAH), a catabolic enzyme responsible for degradation of endocannabinoids, e.g. anandamide (AEA). In the present study, cultured murine microglia were incubated with Tat and/or a FAAH inhibitor (PF3845). After 24 h, cells were imaged for morphological analysis and microglial conditioned media (MCM) was collected. Frontal cortex neuron cultures (DIV 7–11) were then exposed to MCM, and neurotoxicity was assessed via live cell calcium imaging and staining of actin positive dendritic structures. Results demonstrate a strong attenuation of microglial responses to Tat by PF3845 pretreatment, which is indicated by 1) microglial changes in morphology to a less proinflammatory phenotype using fractal analysis, 2) a decrease in release of neurotoxic cytokines/chemokines (MCP-1/CCL2) and matrix metalloproteinases (MMPs; MMP-9) using ELISA/multiplex assays, and 3) enhanced production of endocannabinoids (AEA) using LC/MS/MS. Additionally, PF3845\u27s effects on Tat-induced microglial-mediated neurotoxicity, decreased dysregulation of neuronal intracellular calcium and prevented the loss of actin-positive staining and punctate structure in frontal cortex neuron cultures. Interestingly, these observed neuroprotective effects appeared to be independent of cannabinoid receptor activity (CB1R & CB2R). We found that a purported GPR18 antagonist, CID-85469571, blocked the neuroprotective effects of PF3845 in all experiments. Collectively, these experiments increase understanding of the role of FAAH inhibition and Tat in mediating microglial neurotoxicity in the HAND condition

    Comparative phylogeography of reef fishes from the Gulf of Aden to the Arabian Sea reveals two cryptic lineages

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    Arabian Sea is a heterogeneous region with high coral cover and warm stable conditions at the western end (Djibouti), in contrast to sparse coral cover, cooler temperatures, and upwelling at the eastern end (southern Oman). We tested for barriers to dispersal across this region (including the Gulf of Aden and Gulf of Oman), using mitochondrial DNA surveys of 11 reef fishes. Study species included seven taxa from six families with broad distributions across the Indo-Pacific and four species restricted to the Arabian Sea (and adjacent areas). Nine species showed no significant genetic partitions, indicating connectivity among contrasting environments spread across 2000 km. One butterflyfish (Chaetodon melannotus) and a snapper (Lutjanus kasmira) showed phylogenetic divergences of d = 0.008 and 0.048, respectively, possibly indicating cryptic species within these broadly distributed taxa. These genetic partitions at the western periphery of the Indo-Pacific reflect similar partitions recently discovered at the eastern periphery of the Indo-Pacific (the Hawaiian and the Marquesan Archipelagos), indicating that these disjunctive habitats at the ends of the range may serve as evolutionary incubators for coral reef organisms. © 2017 Springer-Verlag Berlin HeidelbergTh

    The Black Sea Turks: some aspects of their ethnic and cultural background

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    Donated by Klaus Kreise

    The Dede Korkut ethic

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    Donated by Klaus Kreise

    « L’exception turque » : un héritage de la culture politique ottomane

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    La République turque se distingue des autres États-nations établis en terre d’Islam par la nature des relations nouées entre l’État et la société. L’Empire ottoman s’était organisé à travers une culture politique particulière fondée sur une nette séparation entre les tenants du pouvoir (insiders) et ceux qui en étaient exclus (outsiders). À l’âge classique, seule la classe dirigeante, pourvue de liens plus ou moins directs avec le Palais, participa à cette culture politique. À l’âge post-clas..

    Ottoman legacy of Turkish modernity

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    This innovative study of modern Turkey is the result of many years of ethnographic fieldwork and archival research. Michael Meeker expertly combines anthropological and historical methods to examine the transition from the Ottoman Empire to the Turkish Republic in a major region of the country, the eastern Black Sea coast. His most significant finding is that a state-oriented provincial oligarchy played a key role in successive programs of reform over the course of more than two hundred years of imperial and national history. As Meeker demonstrates, leading individuals backed by interpersonal networks determined the outcome of the modernizing process, first during the westernizing period of the Empire, then during the revolutionary period of the Republic.To understand how such a state-oriented provincial oligarchy was produced and reproduced along the eastern Black Sea coast, Meeker integrates a contemporary ethnographic study of public life in towns and villages with a historical study of official documents, consular reports, and travel narratives. A Nation of Empire provides anthropologists, historians, and students of Eastern Europe and the Middle East with a new understanding of the complexities and contradictions of modern Turkish experience
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