772 research outputs found

    Rapidly assessing the risks of infectious diseases to wildlife species

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    Predicting the likelihood of rare events is increasingly demanded by risk managers. A key challenge is dealing with different types of uncertainty, including epistemic uncertainties (lack of knowledge), stochasticity (inherent randomness) and natural variation. One potentially catastrophic event which is impacted by high levels of all three of these uncertainty types is the transmission of livestock pathogens to wildlife, particularly for endangered species. There is often a lack of basic information, e.g. about a given pathogen's presence in local livestock populations or the susceptibility of a given wildlife species to infection by the pathogen. We adapted the OIE (World Organisation for Animal Health) risk assessment framework to rapidly assess and prioritize the risks of livestock pathogens for wildlife, taking account of epistemic uncertainties, stochasticity, seasonal movement of animals and interaction between different species at different spatial and temporal scales. We demonstrate the approach using the endangered saiga antelope (Saiga tatarica tatarica) as a case study. We conclude that, in general, transmission events are likely to be rare and limited to small geographical areas; however, their impact could be high. Brucella spp. and foot-and-mouth disease virus are among those most likely to be transmitted from livestock to the Betpak-Dala saiga population

    Resistless electron beam lithography process for the fabrication of sub-50 nm silicide structures

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    We report on a study of the fabrication of submicron silicide structures with a resistless lithography technique. Several different metals can be used as a basis for producing silicide using this method; in this work, results will be discussed for both platinum and nickel silicide. The feasibility of producing nanostructures using polycrystalline silicon as a base growth layer for metal–oxide– semiconductor, and other device applications have also been demonstrated. Threshold doses for this method for submicron lines (<50 nm) and square areas were obtained in order to establish a framework for the fabrication of more complex devices. Preliminary electrical measurements were carried out which indicate that the resistivity of the silicide is 45 [mu omega] cm, and that the barrier height of the silicide/(high resistivity silicon) interface is 0.56 eV

    Coordination of ECA Rules by Verification and Control

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    International audienceEvent-Condition-Action (ECA) rules are a widely used language for the high level specification of controllers in adaptive systems, such as Cyber-Physical Systems and smart environments, where devices equipped with sensors and actuators are controlled according to a set of rules. The evaluation and execution of every ECA rule is considered to be independent from the others, but interactions of rule actions can cause the system behaviors to be unpredictable or unsafe. Typical problems are in redundancy of rules, inconsistencies, circularity, or application-dependent safety issues. Hence, there is a need for coordination of ECA rule-based systems in order to ensure safety objectives. We propose a tool-supported method for verifying and controlling the correct interactions of rules, relying on formal models related to reactive systems, and Discrete Controller Synthesis (DCS) to generate correct rule controllers

    Passive solid state microdosimeter with electronic readout

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    Apparatus and method for qualitatively and quantitatively analyzing a complex radiation field are provided. A passive microdosimetry detector device records the energy deposition of incident radiation using an array of microstructure non-volatile memory devices. Each microstructure non-volatile memory device is capable of storing a predetermined initial charge without requiring a power source. A radiation particle incident to a microstructure non-volatile memory device is termed an event . Each such event may generate a charge within a sensitive volume defined by the microstructure non-volatile memory device. The charge generated within the sensitive volume alters the stored initial charge by an amount falling within a range corresponding to the energy deposited by certain particle types. Data corresponding to such charge alterations for a plurality of microstructure non-volatile memory devices within an array of such devices are presented to a qualitative analyzing device. The qualitative analyzing device converts the data to a spectral analysis of the incident radiation field by applying ICRP-recommended weighting factors to individual events or approximations thereof

    New York State dairy farmers&apos; perceptions of antibiotic use and resistance : A qualitative interview study

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    Antibiotic resistance is a global problem affecting both human and animal health. Ensuring the strategic and effective use of antibiotics is paramount to combatting the emergence and spread of resistance. This study explored New York State (NYS) dairy farmers' perceptions regarding antibiotic use in dairy farming and antibiotic resistance. Dairy farmers' perceptions were assessed through semi-structured, in-person interviews. Twenty interviews with farm owners and/or managers of 15 conventional and five USDA certified organic dairy farms with 40 to 2,300 lactating cows were conducted. Thematic analysis was used to assess, compare and contrast transcripts for farmers' characterization of their beliefs, values, and concerns. Conventional dairy farmers had a low level of concern about the possible impacts of on-farm antibiotic resistance on human health and believed their antibiotic use was already judicious. Generally, they believed their cattle's health would suffer if antibiotic use were further curtailed. Conventional farmers expressed frustration over the possibility of more stringent governmental, milk cooperative, buyer, or marketer requirements for antibiotic use and associated animal welfare in the future. They attributed expanding regulations in part to misinformed consumer preferences, that farmers felt were influenced by the marketing of organic dairy products. Organic dairy farmers were generally more concerned about issues related to antibiotic resistance than conventional farmers. Both conventional and organic farmers placed emphasis on disease prevention through herd health management rather than treatment. In conclusion, the conventional NYS dairy farmers in this study were skeptical of the need for and benefits of reduced antibiotic use on their dairy farms. Interventions for farmers, delivered by a trusted source such as a veterinarian, that provide training about proper antibiotic use practices and information of possible financial benefits of refining antibiotic use may hold promise

    Who acquires infection from whom and how? Disentangling multi-host and multi-mode transmission dynamics in the 'elimination' era

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    Multi-host infectious agents challenge our abilities to understand, predict and manage disease dynamics. Within this, many infectious agents are also able to use, simultaneously or sequentially, multiple modes of transmission. Furthermore, the relative importance of different host species and modes can itself be dynamic, with potential for switches and shifts in host range and/ or transmission mode in response to changing selective pressures, such as those imposed by disease control interventions. The epidemiology of such multi-host, multi-mode infectious agents thereby can involve a multi-faceted community of definitive and intermediate/secondary hosts or vectors, often together with infectious stages in the environment, all of which may represent potential targets, as well as specific challenges, particularly where disease elimination is proposed. Here, we explore, focusing on examples fromboth human and animal pathogen systems, why and how we should aim to disentangle and quantify the relative importance of multi-host multi-mode infectious agent transmission dynamics under contrasting conditions, and ultimately, how this can be used to help achieve efficient and effective disease control. This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'
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