5,860 research outputs found

    A quiet politics of being together: Miriam and Rose

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    This paper draws on fieldwork with a befriending scheme that pairs refugees, asylum seekers and local residents in the north east of England. It explores the ways in which a ‘quiet politics’ of encounter, embedded in intimate relationships, is caught up in and productive of complex inter-scale geographies, highlighting the ebbs and flows across security and insecurity. Critically, it foregrounds the relationality of emotions in enabling and maintaining intimate-geopolitics

    Land tenure in Ethiopia: Continuity and change, shifting rulers, and the quest for state control

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    "Ethiopia experiences a fierce political debate about the appropriate land tenure policy. After the fall of the socialist derg regime in 1991, land property rights have remained vested in the state and only usufruct rights have been alienated to farmers – to the disappointment of international donor agencies. This has nurtured an antagonistic debate between advocates of the privatization of land property rights to individual plot holders and those supporting the government's position. This debate, however, fails to account for the diversity and continuities in Ethiopian land tenure systems. This paper reviews the changing bundles of rights farmers have held during various political regimes in Ethiopia, the imperial, the derg and the current one, at different times and places. Our analysis indicates the marked differences in tenure arrangements after the fall of the empire, but identifies some commonalities in land tenure regimes as well, in particular between the traditional rist system and the current tenure system." authors' abstractLand tenure, Property rights regime, Bundles of rights, Legal pluralism, Devolution,

    Software-Defined Networks Supporting Time-Sensitive In-Vehicular Communication

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    Future in-vehicular networks will be based on Ethernet. The IEEE Time-Sensitive Networking (TSN) is a promising candidate to satisfy real-time requirements in future car communication. Software-Defined Networking (SDN) extends the Ethernet control plane with a programming option that can add much value to the resilience, security, and adaptivity of the automotive environment. In this work, we derive a first concept for combining Software-Defined Networking with Time-Sensitive Networking along with an initial evaluation. Our measurements are performed via a simulation that investigates whether an SDN architecture is suitable for time-critical applications in the car. Our findings indicate that the control overhead of SDN can be added without a delay penalty for the TSN traffic when protocols are mapped properly.Comment: To be published at IEEE VTC2019-Sprin

    Simulation of Mixed Critical In-vehicular Networks

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    Future automotive applications ranging from advanced driver assistance to autonomous driving will largely increase demands on in-vehicular networks. Data flows of high bandwidth or low latency requirements, but in particular many additional communication relations will introduce a new level of complexity to the in-car communication system. It is expected that future communication backbones which interconnect sensors and actuators with ECU in cars will be built on Ethernet technologies. However, signalling from different application domains demands for network services of tailored attributes, including real-time transmission protocols as defined in the TSN Ethernet extensions. These QoS constraints will increase network complexity even further. Event-based simulation is a key technology to master the challenges of an in-car network design. This chapter introduces the domain-specific aspects and simulation models for in-vehicular networks and presents an overview of the car-centric network design process. Starting from a domain specific description language, we cover the corresponding simulation models with their workflows and apply our approach to a related case study for an in-car network of a premium car

    Lateral flow (immuno)assay: its strengths, weaknesses, opportunities and threats. A literature survey

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    Lateral flow (immuno)assays are currently used for qualitative, semiquantitative and to some extent quantitative monitoring in resource-poor or non-laboratory environments. Applications include tests on pathogens, drugs, hormones and metabolites in biomedical, phytosanitary, veterinary, feed/food and environmental settings. We describe principles of current formats, applications, limitations and perspectives for quantitative monitoring. We illustrate the potentials and limitations of analysis with lateral flow (immuno)assays using a literature survey and a SWOT analysis (acronym for 'strengths, weaknesses, opportunities, threats'). Articles referred to in this survey were searched for on MEDLINE, Scopus and in references of reviewed papers. Search terms included 'immunochromatography', 'sol particle immunoassay', 'lateral flow immunoassay' and 'dipstick assay'

    The effect of Nb2O5 and ZrO2 additions on the behaviour of Li/MgO and Li/Na/MgO catalysts for the oxidative coupling of methane

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    Incorporation of Nb2O5 or ZrO2 into both Li/MgO and Li/Na/MgO systems produced ternary and quaternary catalysts, respectively, capable of attaining optimal C2 yields and selectivities at lower temperatures relative to the unpromoted materials. The degree of enhancement effected by these metal oxide additives was compared to that produced by Li/MgO and Li/Na/MgO catalysts promoted with SnO2 or Co3O4. At reaction temperatures < 700°C, the Li/Co/MgO ternary system showed marked differences in behaviour compared to the other ternary catalysts tested. This was particularly evident in the variation in C2 selectivity with time on stream during ageing studies of (i) untreated materials, (ii) materials pretreated in CO2, and (iii) materials dosed periodically with CHCI3

    An investigation of the comparative reactivities of ethane and ethylene in the presence of oxygen over Li/MgO and Ca/Sm2O3 catalysts in relation to the oxidative coupling of methane

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    In order to examine the importance of the further oxidation of the desired C2 products in the oxidative coupling of methane, ethylene and ethane have been added to the feed (containing methane and oxygen) to a Li/MgO or Ca/Sm2O3 catalyst. The results of these measurements show that neither of these C2 molecules is stable under these conditions with either of the catalysts. Additionally, the rates of the oxidation of ethane and of ethylene alone have been measured using a gradientless reactor for both catalysts as well as for a quartz bed. It was found that the Ca/Sm2O3 material had higher activities for the oxidation of C2H6 and C2H4 (and also of CH4) than had the Li/MgO material. These higher activities result in a lower optimal reaction temperature for the oxidative coupling of methane and are (at least partially) responsible for the lower selectivity to C2 products observed with the Ca/Sm2O3 catalyst compared to that with the Li/MgO catalyst

    Human Stem Cells: Is it Possible to Limit Pluripotent Human Stem Cells to Differentiate into Specific Tissue or Organ?

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    It would seem that differentiation of stem cells is the remedy of modern times. Yet stem cell research is more complex that the public may recognize and is still in the developmental stage. Recent breakthroughs show promise; various guidelines provide structure to this growing field but it is not ready for gross public application. The objective of this paper is to research various different methods of stem cell production and application. Methods included reviewing articles and studies to evaluate the process in production of affective stem cells. There are many therapies that illustrate this research. Upon completing and explaining this phase, further analysis of research presented risk factors such as negative immune responses, tumor, and teratoma formation are discussed. This paper further examines the different complications that may be triggered by stem cell therapy. The danger analysis is briefed to describe the risks involved in stem cell therapy while explaining the ongoing research and discoveries to assist in limiting these risks. This paper culminated with the success of the most affective form of therapy to date. There are ongoing studies directed to limiting stem cell therapy for safe and risk-free application. Nevertheless, no definite conclusion can be reached as to how stem cells can be limited to the point of remaining simultaneously pluripotent and effective
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