7,067 research outputs found

    Binary Relations as a Foundation of Mathematics

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    We describe a theory for binary relations in the Zermelo-Fraenkel style. We choose for ZFCU, a variant of ZFC Set theory in which the Axiom of Foundation is replaced by an axiom allowing for non-wellfounded sets. The theory of binary relations is shown to be equi-consistent ZFCU by constructing a model for the theory of binary relations in ZFU and vice versa. Thus, binary relations are a foundation for mathematics in the same sense as sets are

    Improved solid state electron-charge-storage device

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    Storage device is applicable in memory systems and in high-resolution arrays for light-responsive image sensing. The device offers high yield in multiple arrays and allows charge release with light striking only the edge of a metal electrode

    CadC-mediated activation of the cadBA promoter in Escherichia coli

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    The transcriptional activator CadC in Escherichia coli, a member of the ToxR-like proteins, activates transcription of the cadBA operon encoding the lysine decarboxylase CadA and the lysine-cadaverine antiporter CadB. cadBA is induced under conditions of acidic external pH and exogenous lysine; anoxic conditions raise the expression level up to 10 times. To characterize the binding mechanism of CadC, procedures for the purification of this membrane-integrated protein and its reconstitution into proteoliposomes were established. The binding sites of CadC upstream of the cadBA promoter region were determined by in vitro DNaseI protection analysis. Two regions were protected during DNaseI digestion, one from - 144 to - 112 bp, designated Cad1, and another one from - 89 to - 59 bp, designated Cad2. Binding of purified CadC to Cad1 and Cad2 was further characterized by DNA-binding assays, indicating that CadC was able to bind to both DNA fragments. Genetic analysis with promoter-lacZ fusions confirmed that both sites, Cad1 and Cad2, are essential for activation of cadBA transcription. Moreover, these experiments revealed that binding of H-NS upstream of the CadC-binding sites is necessary for repression of cadBA expression at neutral pH and under aerobic conditions. Based on these results, a model for transcriptional regulation of the cadBA operon is proposed, according to which H-NS is involved in the formation of a repression complex under non-inducing conditions. This complex is dissolved by binding of CadC to Cad1 under inducing conditions. Upon binding of CadC to Cad2 cadBA expression is activated. Copyright (C) 2005 S. Karger AG, Basel

    Silicon surface passivation for devices Quarterly status report

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    Water contamination in thermal oxide on silico

    The appropriateness of canal water supplies: The response of the farmers - A case study in the Fordwah/Eastern Sadiqia area, Punjab, Pakistan

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    Irrigation water / Irrigation canals / Water supply / Farmer managed irrigation systems / Pakistan

    Dynamic conditional correlation analysis of financial market interdependence: An application to Thailand and Indonesia

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    This paper examines the dynamic linkages among financial markets in Thailand and Indonesia. In particular, we focus on the cross-border relationship in individual markets and on the relationship between finan- cial markets within each country. We find that while tight monetary policy pursued by Thailand authorities helped to defend the exchange rate at the outbreak of the financial crisis, it had little consequences for Indonesia at the end of 1998. The correlations between countries within each of the financial market reveals a certain degree of interde- pendence among countries, which is lower during crises.

    Urbanization, ethnicity and cardiovascular risk in a population in transition in Nakuru, Kenya: a population-based survey.

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    BACKGROUND: Cardiovascular disease (CVD) is the leading cause of death among older people in Africa. This study aimed to investigate the relationship of urbanization and ethnicity with CVD risk markers in Kenya. METHODS: A cross-sectional population-based survey was carried out in Nakuru Kenya in 2007-2008. 100 clusters of 50 people aged ā‰„ 50 years were selected by probability proportionate to size sampling. Households within clusters were selected through compact segment sampling. Participants were interviewed by nurses to collect socio-demographic and lifestyle information. Nurses measured blood pressure, height, weight and waist and hip circumference. A random finger-prick blood sample was taken to measure glucose and cholesterol levels.Hypertension was defined as systolic blood pressure (SBP) ā‰„ 140 mm Hg, or diastolic blood pressure (DBP) ā‰„ 90 mm Hg or current use of antihypertensive medication; Diabetes as reported current medication or diet control for diabetes or random blood glucose level ā‰„ 11.1 mmol/L; High cholesterol as random blood cholesterol level ā‰„ 5.2 mmol/L; and Obesity as Body Mass Index (BMI)ā‰„ 30 kg/m2. RESULTS: 5010 eligible subjects were selected, of whom 4396 (88%) were examined. There was a high prevalence of hypertension (50.1%, 47.5-52.6%), obesity (13.0%, 11.7-14.5%), diabetes (6.6%, 5.6-7.7%) and high cholesterol (21.1%, 18.6-23.9). Hypertension, diabetes and obesity were more common in urban compared to rural groups and the elevated prevalence generally persisted after adjustment for socio-demographic, lifestyle, obesity and cardiovascular risk markers. There was also a higher prevalence of hypertension, obesity, diabetes and high cholesterol among Kikuyus compared to Kalenjins, even after multivariate adjustment. CVD risk markers were clustered both across the district and within individuals. Few people received treatment for hypertension (15%), while the majority of cases with diabetes received treatment (68%). CONCLUSIONS: CVD risk markers are common in Kenya, particularly in urban areas. Exploring differences in CVD risk markers between ethnic groups may help to elucidate the epidemiology of these conditions

    Study of dynamics of charge trapping in a-Si:H/SiN TFTs

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    In this paper we present the study of the failure mechanism responsible for long-term degradation that ultimately leads to instability in a-Si:H/SiN TFTs. The experimental data points we obtain by monitoring in-situ the drain current during gate bias stress (forward and reverse bias) and relaxation could not be fitted with the models existent in the literature. A new model that we have christened "Progressive Degradation Model" (PDM) emerged. The model makes use of Heimann-Warfield theory of trapping/detrapping front. PDM achieves a consistent fit to any bias condition showing that the degradation can be modelled quantitatively yielding the number of traps involved, their position and the charge dispersion coefficient. According to PDM the degradation of electrical response is a combined effect of a fast interface traps generation and a slow charge trapping at the created defect sites in a-SiN:H transitional region

    Flexible Sensor Network Reprogramming for Logistics

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    Besides the currently realized applications, Wireless Sensor Networks can be put to use in logistics processes. However, doing so requires a level of flexibility and safety not provided by the current WSN software platforms. This paper discusses a logistics scenario, and presents SensorScheme, a runtime environment used to realize this scenario, based on semantics of the Scheme programming language. SensorScheme is a general purpose WSN platform, providing dynamic reprogramming, memory safety (sandboxing), blocking I/O, marshalled communication, compact code transport. It improves on the state of the art by making better use of the little available memory, thereby providing greater capability in terms of program size and complexity. We illustrate the use of our platform with some application examples, and provide experimental results to show its compactness, speed of operation and energy efficiency
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