1,683 research outputs found

    Initiation of hepatitis C virus infection is dependent on cholesterol and cooperativity between CD81 and scavenger receptor B type I.

    Get PDF
    In the past several years, a number of cellular proteins have been identified as candidate entry receptors for hepatitis C virus (HCV) by using surrogate models of HCV infection. Among these, the tetraspanin CD81 and scavenger receptor B type I (SR-BI), both of which localize to specialized plasma membrane domains enriched in cholesterol, have been suggested to be key players in HCV entry. In the current study, we used a recently developed in vitro HCV infection system to demonstrate that both CD81 and SR-BI are required for authentic HCV infection in vitro, that they function cooperatively to initiate HCV infection, and that CD81-mediated HCV entry is, in part, dependent on membrane cholesterol

    Cryptococcus--diversity of clinical presentation

    Get PDF

    Ideal Bandgap in a 2D Ruddlesden-Popper Perovskite Chalcogenide for Single-junction Solar Cells

    Full text link
    Transition metal perovskite chalcogenides (TMPCs) are explored as stable, environmentally friendly semiconductors for solar energy conversion. They can be viewed as the inorganic alternatives to hybrid halide perovskites, and chalcogenide counterparts of perovskite oxides with desirable optoelectronic properties in the visible and infrared part of the electromagnetic spectrum. Past theoretical studies have predicted large absorption coefficient, desirable defect characteristics, and bulk photovoltaic effect in TMPCs. Despite recent progresses in polycrystalline synthesis and measurements of their optical properties, it is necessary to grow these materials in high crystalline quality to develop a fundamental understanding of their optical properties and evaluate their suitability for photovoltaic application. Here, we report the growth of single crystals of a two-dimensional (2D) perovskite chalcogenide, Ba3Zr2S7, with a natural superlattice-like structure of alternating double-layer perovskite blocks and single-layer rock salt structure. The material demonstrated a bright photoluminescence peak at 1.28 eV with a large external luminescence efficiency of up to 0.15%. We performed time-resolved photoluminescence spectroscopy on these crystals and obtained an effective recombination time of ~65 ns. These results clearly show that 2D Ruddlesden-Popper phases of perovskite chalcogenides are promising materials to achieve single-junction solar cells.Comment: 4 Figure

    HEAPCRAFT: Quantifying and Predicting Collaboration in Minecraft

    Get PDF
    We present HEAPCRAFT: an open-source suite of tools for monitoring and improving collaboration in Minecraft. At the core of our system is a data collection and analysis framework or recording gameplay. We collected over 3451 playerhours of game behavior from 908 different players, and performed a general study of online collaboration. To make our game analytics easily accessible, we developed interactive information visualization tools and an analysis framework for players, administrators, and researchers to explore graphs, maps and timelines of live server activity. As part of our research, we introduce the collaboration index, a metric which allows server administrators and researchers to quantify, predict, and improve collaboration on Minecraft servers. Our analysis reveals several possible predictors of collaboration which can be used to improve collaboration on Minecraft servers. HEAPCRAFT is designed to be general, and has the potential to be used for other shared online virtual worlds

    Linking Home and Market:

    Get PDF
    Summaries This article identifies changing labour market relations in West Bengal agriculture and argues that these cannot be fully explained without extending the analysis beyond paid work to the questions of who does what work and why inside labour?selling households. The pragmatic approach to employer?worker negotiation adopted by the ruling Communist Party of India (Marxist) at the local level is built on an implicit understanding of agricultural worker households' unwaged work. While unwaged work may enable labour?sellers to negotiate higher wages, it also adds to employers' capacity to contain wage rises. Moreover, ascribed ‘responsibility’ for unwaged work to certain individuals within a household means that those people are less able to enter contractual arrangements involving prior commitments. At the same time the withdrawal of women in status?aspiring groups from involvement in paid work contributes to the increasing incidence of seasonally tied labour arrangements. Thus, workers' actions are both contingent on and constitutive of the wider structures in which they operate. Understanding the meaning of the closing wage gap between men and women in West Bengal, and the paradoxical continuity of a low proportion of women among agricultural workers requires analysis of how those structures, including ideologies of gender and caste as well as contractual arrangements (for both local and seasonal migrant workers) and the practices of political parties, change over time

    HeapCraft Social Tools: Understanding and Improving Player Collaboration in Minecraft

    Get PDF
    We introduce a framework to infuence and analyze player collaboration in Minecraft. The framework consists of a telemetry system and several tools to influence player behavior and provide value to server administrators to increase adoption. The data collection includes almost every aspect of gameplay and can be used for analysis beyond player collaboration.1 We started collecting data from several Minecraft servers in March 2015. Most data will be made available to researchers upon request.2 We have also demonstrated the use of our framework to statistically analyze player behavior in Minecraft. More details can be found [1]

    Authoring Multi-Actor Behaviors in Crowds With Diverse Personalities

    Get PDF
    Multi-actor simulation is critical to cinematic content creation, disaster and security simulation, and interactive entertainment. A key challenge is providing an appropriate interface for authoring high-fidelity virtual actors with featurerich control mechanisms capable of complex interactions with the environment and other actors. In this chapter, we present work that addresses the problem of behavior authoring at three levels: Individual and group interactions are conducted in an event-centric manner using parameterized behavior trees, social crowd dynamics are captured using the OCEAN personality model, and a centralized automated planner is used to enforce global narrative constraints on the scale of the entire simulation. We demonstrate the benefits and limitations of each of these approaches and propose the need for a single unifying construct capable of authoring functional, purposeful, autonomous actors which conform to a global narrative in an interactive simulation

    Exposure of fibrinogen and thrombin to nitric oxide donor ProliNONOate affects fibrin clot properties

    Get PDF
    Fibrin fibers form the structural backbone of blood clots. The structural properties of fibrin clots are highly dependent on formation kinetics. Environmental factors such as protein concentration, pH, salt, and protein modification, to name a few, can affect fiber kinetics through altered fibrinopeptide release, monomer association, and/or lateral aggregation. The objective of our study was to determine the effect of thrombin and fibrinogen exposed to nitric oxide on fibrin clot properties. ProliNONOate (5 [mu]mol/l) was added to fibrinogen and thrombin before clot initiation and immediately following the addition of thrombin to the fibrinogen solution. Resulting fibrin fibers were probed with an atomic force microscope to determine their diameter and extensibility and fibrin clots were analyzed for clot density using confocal microscopy. Fiber diameters were also determined by confocal microscopy and the rate of clot formation was recorded using UV-vis spectrophotometry. Protein oxidation and S-nitrosation was determined by UV-vis, ELISA, and chemiluminescence. The addition of ProliNONOate to fibrinogen or thrombin resulted in a change in clot structure. ProliNONOate exposure produced clots with lower fiber density, thicker fibers, and increased time to maximum turbidity. The effect of the exposure of nitric oxide to thrombin and fibrinogen were measured independently and indicated that each plays a role in altering clot properties. We detected thrombin S-nitrosation and protein carbonyl formation after nitric oxide exposure. Our study reveals a regulation of fibrin clot properties by nitric oxide exposure and suggests a role of peroxynitrite in oxidative modifications of the proteins. These results relate nitric oxide bioavailability and oxidative stress to altered clot properties

    A rare midbrain infarction presenting with plus-minus lid syndrome with ataxia: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>We present the case of a patient with midbrain infarction with an unusual clinical presentation, where clinical diagnosis and anatomical localization were valuable tools in deciding treatment.</p> <p>Case presentation</p> <p>Our patient was a 59-year-old, right-handed Caucasian man with hypertension who presented to our facility with acute diplopia that persisted until he developed complete right-sided ptosis. He also had difficulty walking and coordinating movements of his upper extremities bilaterally, but this was worse on his left side.</p> <p>Conclusions</p> <p>Plus-minus lid syndrome with ataxia is a rare presentation of midbrain infarction with a unique localization and anatomical description. This case highlights the importance of clinical skills for making a diagnosis in the absence of imaging to confirm the findings.</p
    • …
    corecore