297 research outputs found

    AC-coupled GaAs microstrip detectors with a new type of integrated bias resistors

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    Full size single-sided GaAs microstrip detectors with integrated coupling capacitors and bias resistors have been fabricated on 3'' substrate wafers. PECVD deposited SiO_2 and SiO_2/Si_3N_4 layers were used to provide coupling capacitaces of 32.5 pF/cm and 61.6 pF/cm, respectively. The resistors are made of sputtered CERMET using simple lift of technique. The sheet resistivity of 78 kOhm/sq. and the thermal coefficient of resistance of less than 4x10^-3 / degree C satisfy the demands of small area biasing resistors, working on a wide temperature range.Comment: 20 pages, 9 figures, to be published in NIM

    An ontology for strongly sustainable business models: Defining an enterprise framework compatible with natural and social science

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    Business is increasingly employing sustainability practices, aiming to improve environmental and social responsibility while maintaining and improving profitability. For many organizations, profit-oriented business models are a major constraint impeding progress in sustainability. A formally defined ontology, a model definition, for profit-oriented business models has been employed globally for several years. However, no equivalent ontology is available in research or practice that enables the description of strongly sustainable business models, as validated by ecological economics and derived from natural, social, and system sciences. We present a framework of strongly sustainable business model propositions and principles as findings from a transdisciplinary review of the literature. A comparative analysis was performed between the framework and the Osterwalder profit-oriented ontology for business models. We introduce an ontology that enables the description of successful strongly sustainable business models that resolves weaknesses and includes functionally necessary relationships

    In vivo serotonin 1A receptor hippocampal binding potential in depression and reported childhood adversity

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    Abstract Background Reported childhood adversity (CA) is associated with development of depression in adulthood and predicts a more severe course of illness. Although elevated serotonin 1A receptor (5-HT1AR) binding potential, especially in the raphe nuclei, has been shown to be a trait associated with major depression, we did not replicate this finding in an independent sample using the partial agonist positron emission tomography tracer [11C]CUMI-101. Evidence suggests that CA can induce long-lasting changes in expression of 5-HT1AR, and thus, a history of CA may explain the disparate findings. Methods Following up on our initial report, 28 unmedicated participants in a current depressive episode (bipolar n = 16, unipolar n = 12) and 19 non-depressed healthy volunteers (HVs) underwent [11C]CUMI-101 imaging to quantify 5-HT1AR binding potential. Participants in a depressive episode were stratified into mild/moderate and severe CA groups via the Childhood Trauma Questionnaire. We hypothesized higher hippocampal and raphe nuclei 5-HT1AR with severe CA compared with mild/moderate CA and HVs. Results There was a group-by-region effect (p = 0.011) when considering HV, depressive episode mild/moderate CA, and depressive episode severe CA groups, driven by significantly higher hippocampal 5-HT1AR binding potential in participants in a depressive episode with severe CA relative to HVs (p = 0.019). Contrary to our hypothesis, no significant binding potential differences were detected in the raphe nuclei (p -value s > 0.05). Conclusions With replication in larger samples, elevated hippocampal 5-HT1AR binding potential may serve as a promising biomarker through which to investigate the neurobiological link between CA and depression

    Activation of adherent vascular neutrophils in the lung during acute endotoxemia

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    BACKGROUND: Neutrophils constitute the first line of defense against invading microorganisms. Whereas these cells readily undergo apoptosis under homeostatic conditions, their survival is prolonged during inflammatory reactions and they become biochemically and functionally activated. In the present study, we analyzed the effects of acute endotoxemia on the response of a unique subpopulation of neutrophils tightly adhered to the lung vasculature. METHODS: Rats were treated with 5 mg/kg lipopolysaccharide (i.v.) to induce acute endotoxemia. Adherent neutrophils were isolated from the lung vasculature by collagenase digestion and sequential filtering. Agarose gel electrophoresis, RT-PCR, western blotting and electrophoretic mobility shift assays were used to evaluate neutrophil activity. RESULTS: Adherent vascular neutrophils isolated from endotoxemic animals exhibited decreased apoptosis when compared to cells from control animals. This was associated with a marked increase in expression of the anti-apoptotic protein, Mcl-1. Cells isolated 0.5–2 hours after endotoxin administration were more chemotactic than cells from control animals and expressed increased tumor necrosis factor-alpha and cyclooxygenase-2 mRNA and protein, demonstrating that they are functionally activated. Endotoxin treatment of the animals also induced p38 and p44/42 mitogen activated protein kinases in the adherent lung neutrophils, as well as nuclear binding activity of the transcription factors, NF-κB and cAMP response element binding protein. CONCLUSION: These data demonstrate that adherent vascular lung neutrophils are highly responsive to endotoxin and that pathways regulating apoptosis and cellular activation are upregulated in these cells

    Accounting for dynamic fluctuations across time when examining fMRI test-retest reliability: Analysis of a reward paradigm in the EMBARC study

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    Longitudinal investigation of the neural correlates of reward processing in depression may represent an important step in defining effective biomarkers for antidepressant treatment outcome prediction, but the reliability of reward-related activation is not well understood. Thirty-seven healthy control participants were scanned using fMRI while performing a reward-related guessing task on two occasions, approximately one week apart. Two main contrasts were examined: right ventral striatum (VS) activation fMRI BOLD signal related to signed prediction errors (PE) and reward expectancy (RE). We also examined bilateral visual cortex activation coupled to outcome anticipation. Significant VS PE-related activity was observed at the first testing session, but at the second testing session, VS PE-related activation was significantly reduced. Conversely, significant VS RE-related activity was observed at time 2 but not time 1. Increases in VS RE-related activity from time 1 to time 2 were significantly associated with decreases in VS PE-related activity from time 1 to time 2 across participants. Intraclass correlations (ICCs) in VS were very low. By contrast, visual cortex activation had much larger ICCs, particularly in individuals with high quality data. Dynamic changes in brain activation are widely predicted, and failure to account for these changes could lead to inaccurate evaluations of the reliability of functional MRI signals. Conventional measures of reliability cannot distinguish between changes specified by algorithmic models of neural function and noisy signal. Here, we provide evidence for the former possibility: reward-related VS activations follow the pattern predicted by temporal difference models of reward learning but have low ICCs
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