120 research outputs found

    Tool support for reasoning in display calculi

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    We present a tool for reasoning in and about propositional sequent calculi. One aim is to support reasoning in calculi that contain a hundred rules or more, so that even relatively small pen and paper derivations become tedious and error prone. As an example, we implement the display calculus D.EAK of dynamic epistemic logic. Second, we provide embeddings of the calculus in the theorem prover Isabelle for formalising proofs about D.EAK. As a case study we show that the solution of the muddy children puzzle is derivable for any number of muddy children. Third, there is a set of meta-tools, that allows us to adapt the tool for a wide variety of user defined calculi

    Kompetenzentwicklung und Bildungsentscheidungen im Vor- und Grundschulalter

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    "In den meisten soziologischen Theorien zu Bildungsungleichheiten gehen die Verfasser davon aus, dass unterschiedliche Schulleistungen vor allem Resultat unterschiedlicher familiärer Bedingungen im Hinblick auf kulturelles Kapital sind. Allerdings wird in neueren soziologischen Studien konzediert, dass Schulleistungen auch als Ergebnis der unterschiedlich ausgeprägten Kompetenzgefüge der Kinder zu betrachten sind. Wenn jedoch überhaupt Kompetenzparameter in quantitative soziologische Analysen einfließen, dann meist in Form von Schulnoten. Diese sind aber nicht unbedingt ein valider Indikator für die kindliche Kompetenzlage, sondern das Ergebnis eines längeren und komplexen Prozesses, in dem auch die Bedingungen in Familie, Kindergarten und Schule wirksam werden. Um die Herausbildung von schichtspezifischen Bildungswegen besser zu verstehen und abschätzen zu können, welcher Stellenwert den Kompetenzen der Kinder zukommt, ist es erforderlich, verschiedene Aspekte kindlicher Kompetenzen zu unterscheiden und diese über einen längeren Zeitraum in ihrer Abhängigkeit von familiären und institutionellen Bedingungen zu untersuchen. In enger Zusammenarbeit von SoziologInnen, PsychologInnen und PädagogInnen wendet sich das BiKS-Projekt derzeit diesen Fragen zu. In dem Vortrag stellen sie zunächst die theoretische Konzeption und das Design der BiKS-Studie vor. Sodann thematisieren sie die Frage, wie in der modernen psychologischen Kompetenzforschung der Gegensatz zwischen angeborenem Potential und Umwelteinflüssen diskutiert wird, und isolieren darauf aufbauend unterschiedliche Aspekte der kognitiven und sprachlichen Kompetenz. Danach präsentieren sie erste empirische Ergebnisse aus dem BiKS-Schullängsschnitt und stellen dar, ob und in welcher Weise kindliche Kompetenzen und Schulnoten mit den familiären Bedingungen kovariieren und auf die Formation von Bildungsentscheidungen einwirken." (Autorenreferat

    Методы повышения эффективности работы газотурбинных установок

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    Объект исследования: газотурбинная установка. Цель работы: аналитический обзор современных направлений повышения эффективности работы ГТУ, сравнительный расчет простой и регенеративной ГТУ при заданных равных условиях. Для достижения поставленной цели рассмотрены следующие задачи: проведение литературного обзора современных направлений повышения эффективности работы газотурбинных установок; сравнительный тепловой расчет простой и регенеративной ГТУ при заданных равных условиях; Определение сметной стоимости работ по монтажу регенератора; анализ вредныхThe object of the study: gas turbine plant. The purpose of the work: analytical review of modern directions of increasing the efficiency of GTP operation, comparative calculation of simple and regenerative GTP under given equal conditions. To achieve this goal, the following tasks are considered: conducting a literature review of modern technologies to increase the efficiency of gas turbine plants; comparative heat calculation of simple and regenerative gas turbine plant (efficiency, specific fuel consumption, heat rate) for given equal conditions; determination of the estimated cost of

    One, two, three: portable sample size in agricultural research

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    Determination of sample size (the number of replications) is a key step in the design of an observational study or randomized experiment. Statistical procedures for this purpose are readily available. Their treatment in textbooks is often somewhat marginal, however, and frequently the focus is on just one particular method of inference (significance test, confidence interval). Here, we provide a unified review of approaches and explain their close interrelationships, emphasizing that all approaches rely on the standard error of the quantity of interest, most often a pairwise difference of two means. The focus is on methods that are easy to compute, even without a computer. Our main recommendation based on standard errors is summarized as what we call the 1-2-3 rule for a difference of two treatment means

    Cerebral Changes Occurring in Arginase and Dimethylarginine Dimethylaminohydrolase (DDAH) in a Rat Model of Sleeping Sickness

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    Involvement of nitric oxide (NO) in the pathophysiology of human African trypanosomiasis (HAT) was analyzed in a HAT animal model (rat infected with Trypanosoma brucei brucei). With this model, it was previously reported that trypanosomes were capable of limiting trypanocidal properties carried by NO by decreasing its blood concentration. It was also observed that brain NO concentration, contrary to blood, increases throughout the infection process. The present approach analyses the brain impairments occurring in the regulations exerted by arginase and N(G), N(G)-dimethylarginine dimethylaminohydrolase (DDAH) on NO Synthases (NOS). In this respect: (i) cerebral enzymatic activities, mRNA and protein expression of arginase and DDAH were determined; (ii) immunohistochemical distribution and morphometric parameters of cells expressing DDAH-1 and DDAH-2 isoforms were examined within the diencephalon; (iii) amino acid profiles relating to NOS/arginase/DDAH pathways were established.Arginase and DDAH activities together with mRNA (RT-PCR) and protein (western-blot) expressions were determined in diencephalic brain structures of healthy or infected rats at various days post-infection (D5, D10, D16, D22). While arginase activity remained constant, that of DDAH increased at D10 (+65%) and D16 (+51%) in agreement with western-blot and amino acids data (liquid chromatography tandem-mass spectrometry). Only DDAH-2 isoform appeared to be up-regulated at the transcriptional level throughout the infection process. Immunohistochemical staining further revealed that DDAH-1 and DDAH-2 are contained within interneurons and neurons, respectively.In the brain of infected animals, the lack of change observed in arginase activity indicates that polyamine production is not enhanced. Increases in DDAH-2 isoform may contribute to the overproduction of NO. These changes are at variance with those reported in the periphery. As a whole, the above processes may ensure additive protection against trypanosome entry into the brain, i.e., maintenance of NO trypanocidal pressure and limitation of polyamine production, necessary for trypanosome growth

    RHAPSODY - Internet-based support for caregivers of people with young onset dementia: program design and methods of a pilot study

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    YesBackground: Young Onset Dementia (YOD), defined by first symptoms of cognitive or behavioral decline occurring before the age of 65 years, is relatively rare compared to dementia of later onset, but it is associated with diagnostic difficulty and heavy burden on affected individuals and their informal carers. Existing health and social care structures rarely meet the needs of YOD patients. Internet-based interventions are a novel format of delivering health-related education, counseling and support to this vulnerable yet underserved group. Methods: The RHAPSODY (Research to Assess Policies and Strategies for Dementia in the Young) project is a European initiative to improve care for people with YOD by providing an internet-based information and skill-building program for family carers. The e-learning program focuses on managing problem behaviors, dealing with role change, obtaining support and looking after oneself. It will be evaluated in a pilot study in three countries using a randomized unblinded design with a wait-list control group. Participants will be informal carers of people with dementia in Alzheimer’s disease or behavioral-variant Frontotemporal degeneration with an onset before the age of 65 years. The primary outcome will be caregiving self-efficacy after 6 weeks of program use. As secondary outcomes caregivers’ stress and burden, carer health-related quality of life, caring-related knowledge, patient problem behaviors and user satisfaction will be assessed. Program utilization will be monitored and a health-economic evaluation will also be performed. Conclusions: The RHAPSODY project will add to the evidence on the potential and limitations of a conveniently accessible, user-friendly and comprehensive internet-based intervention as an alternative for traditional forms of counseling and support in healthcare, aiming to optimize care and support for people with YOD and their informal caregivers.RHAPSODY is an EU Joint Program - Neurodegenerative Disease Research (JPND) project. The project is supported through the following funding organizations under the aegis of JPND (www.jpnd.eu). France: National Research Agency; Germany: Ministry of Education and Research; The Netherlands: The Netherlands Organization for Health Research and Development; Portugal: Foundation for Science and Technology; Sweden: The Swedish Research Council; United Kingdom: Economic and Social Research Council

    Ebola Virion Attachment and Entry into Human Macrophages Profoundly Effects Early Cellular Gene Expression

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    Zaire ebolavirus (ZEBOV) infections are associated with high lethality in primates. ZEBOV primarily targets mononuclear phagocytes, which are activated upon infection and secrete mediators believed to trigger initial stages of pathogenesis. The characterization of the responses of target cells to ZEBOV infection may therefore not only further understanding of pathogenesis but also suggest possible points of therapeutic intervention. Gene expression profiles of primary human macrophages exposed to ZEBOV were determined using DNA microarrays and quantitative PCR to gain insight into the cellular response immediately after cell entry. Significant changes in mRNA concentrations encoding for 88 cellular proteins were observed. Most of these proteins have not yet been implicated in ZEBOV infection. Some, however, are inflammatory mediators known to be elevated during the acute phase of disease in the blood of ZEBOV-infected humans. Interestingly, the cellular response occurred within the first hour of Ebola virion exposure, i.e. prior to virus gene expression. This observation supports the hypothesis that virion binding or entry mediated by the spike glycoprotein (GP1,2) is the primary stimulus for an initial response. Indeed, ZEBOV virions, LPS, and virus-like particles consisting of only the ZEBOV matrix protein VP40 and GP1,2 (VLPVP40-GP) triggered comparable responses in macrophages, including pro-inflammatory and pro-apoptotic signals. In contrast, VLPVP40 (particles lacking GP1,2) caused an aberrant response. This suggests that GP1,2 binding to macrophages plays an important role in the immediate cellular response
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