294 research outputs found

    DEFORMATION MICROSTRUCTURE AND TEXTURE EVOLUTION OF {110}<112> Al-0.3wt.%Mn SINGLE CRYSTALS COMPRESSED IN A CHANNEL-DIE

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    Publié suite au congrès : 10th French-Polish Joint Symposium on Inhomogeneity of Deformation in Materials Univ Paris Sud, Orsay, FRANCE, MAY 19-20, 2008 Pas de DOI : http://www.imim.pl/files/archiwum/Vol1_2009/65-74.pdfInternational audienceCrystal subdivision patterns of microbands have been extensively reported but mostly by studies on only one section, using either TEM or SEM-EBSD. To better correlate substructure with slip patterns a systematic study of the 3D deformation microstructure in a deformed single crystal (i.e. over the 3 perpendicular surfaces) has been carried out. The microstructure and microtexture evolutions during plane strain deformation of high purity single crystals of Al-0.3%wt.Mn alloy with initial ideal and near-brass{110} orientations were characterised by TEM and high resolution FEG-SEM/EBSD after strains of 0.15 and 0.56. These two different techniques enable one to examine the crystal subdivision deformation pattern at different microscopic scales, on the 3 orthogonal sections, i.e. perpendicular to the nominal , and crystallographic directions. Particular attention is paid to a comparison of the microband orientations with the expected slip traces of the 2 active slip systems on all 3 surfaces. It is concluded that the microband boundary alignment corresponds very well to the traces of the crystallographic {111} planes, on which most of the slip occurs

    Rainbow: Combining Improvements in Deep Reinforcement Learning

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    The deep reinforcement learning community has made several independent improvements to the DQN algorithm. However, it is unclear which of these extensions are complementary and can be fruitfully combined. This paper examines six extensions to the DQN algorithm and empirically studies their combination. Our experiments show that the combination provides state-of-the-art performance on the Atari 2600 benchmark, both in terms of data efficiency and final performance. We also provide results from a detailed ablation study that shows the contribution of each component to overall performance.Comment: Under review as a conference paper at AAAI 201

    Innovating healthcare delivery to address noncommunicable diseases in low-income settings: the example of hypertension.

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    London Dialogue event, The Hospital Club, 24 Endell St, London, WC2H 9HQ, London, UK, 1 December 2015 Hypertension is a global health issue causing almost 10 million deaths annually, with a disproportionate number occurring in low- and middle-income countries. The condition can be managed effectively, but there is a need for innovation in healthcare delivery to alleviate its burden. This paper presents a number of innovative delivery models from a number of different countries, including Kenya, Ghana, Barbados and India. These models were presented at the London Dialogue event, which was cohosted by the Novartis Foundation and the London School of Hygiene & Tropical Medicine Centre for Global Noncommunicable Diseases on 1 December 2015. It is argued that these models are applicable not only to hypertension, but provide valuable lessons to address other noncommunicable diseases

    Mitochondrial targeting of cyclosporin A enables selective inhibition of cyclophilin-D and enhanced cytoprotection after glucose and oxygen deprivation

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    CsA (cyclosporin A) is a hydrophobic undecapeptide that inhibits CyPs (cyclophilins), a family of PPIases (peptidylprolyl cis–trans isomerases). In some experimental models, CsA offers partial protection against lethal cell injury brought about by transient ischaemia; this is believed to reflect inhibition of CyP-D, a mitochondrial isoform that facilitates formation of the permeability transition pore in the mitochondrial inner membrane. To evaluate this further, we have targeted CsA to mitochondria so that it becomes selective for CyP-D in cells. This was achieved by conjugating the inhibitor to the lipophilic triphenylphosphonium cation, enabling its accumulation in mitochondria due to the inner membrane potential. In a cell-free system and in B50 neuroblastoma cells the novel reagent (but not CsA itself) preferentially inhibited CyP-D over extramitochondrial CyP-A. In hippocampal neurons, mitochondrial targeting markedly enhanced the capacity of CsA to prevent cell necrosis brought about by oxygen and glucose deprivation, but largely abolished its capacity to inhibit glutamate-induced cell death. It is concluded that CyP-D has a major pathogenic role in ‘energy failure’, but not in glutamate excitotoxicity, where cytoprotection primarily reflects CsA interaction with extramitochondrial CyPs and calcineurin. Moreover, the therapeutic potential of CsA against ischaemia/reperfusion injuries not involving glutamate may be improved by mitochondrial targeting

    Advanced Television Research Program

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    Contains reports on ten research projects.National Science Foundation Grant MIP 87-14969National Science Foundation FellowshipAdvanced Television Research ProgramAT&T Bell Laboratories Doctoral Support ProgramKodak FellowshipU.S. Air Force - Electronic Systems Division Contract F1 9628-89-K-004

    Discovery and Description of Ebola Zaire Virus in 1976 and Relevance to the West African Epidemic During 2013-2016.

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    BACKGROUND: In 1976, the first cases of Ebola virus disease in northern Democratic Republic of the Congo (then referred to as Zaire) were reported. This article addresses who was responsible for recognizing the disease; recovering, identifying, and naming the virus; and describing the epidemic. Key scientific approaches used in 1976 and their relevance to the 3-country (Guinea, Sierra Leone, and Liberia) West African epidemic during 2013-2016 are presented. METHODS: Field and laboratory investigations started soon after notification, in mid-September 1976, and included virus cell culture, electron microscopy (EM), immunofluorescence antibody (IFA) testing of sera, case tracing, containment, and epidemiological surveys. In 2013-2016, medical care and public health work were delayed for months until the Ebola virus disease epidemic was officially declared an emergency by World Health Organization, but research in pathogenesis, clinical presentation, including sequelae, treatment, and prevention, has increased more recently. RESULTS: Filoviruses were cultured and observed by EM in Antwerp, Belgium (Institute of Tropical Medicine); Porton Down, United Kingdom (Microbiological Research Establishment); and Atlanta, Georgia (Centers for Disease Control and Prevention). In Atlanta, serological testing identified a new virus. The 1976 outbreak (280 deaths among 318 cases) stopped in 2 years. Transmission indices (R0) are higher in all 3 countries than in 1976. CONCLUSIONS: An international commission working harmoniously in laboratories and with local communities was essential for rapid success in 1976. Control and understanding of the recent West African outbreak were delayed because of late recognition and because authorities were overwhelmed by many patients and poor community involvement. Despite obstacles, research was a priority in 1976 and recently
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