680 research outputs found

    A hybrid computer program for the visual display of compensatory system model parameters

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    A hybrid computer identification program has been developed which determines and displays those parameter values of a model of the compensatory control system that existed over the last fifteen seconds of operation. These values are up-dated every 0.05 sec so that a visual display of the parameters appears to be continuous. Presently, a closed loop crossover model is being used as the compensatory system model with the parameters K and tau displayed, however, any suitable model could be used in its place

    Nouvelles recherches sur les nystagmus et le sens de l'équilibre

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    Detection of corn and sunflower oil adulterations of olive oils using fluorescence spectroscopy

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    A novel approach for the detection of admixtures of vegetable (corn and sunflower) oils in commercially available olive oils on a qualitative level is presented. Chemical analysis of the contents of fatty acids in each of the model systems under study is performed. The dependence of the ratio of the two main fluorescence intensity peaks 1 2 F / F and that of the linoleic to oleic acids C18:2 / C18:1 is studied. It is shown that an increase of the concentration of the adulterant the maximum of the first fluorescence peak exhibits a wavelength shift. Fluorescence analysis can be used for a qualitative real time determination of the presence of adulterants in olive oil by comparison of the observed particular fluorescence spectrum with those from a database of spectra of olive oils and adulterants from a particular region

    Endogenous testosterone is associated with lower amygdala reactivity to angry faces and reduced aggressive behavior in healthy young women

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    Testosterone and cortisol have been proposed to influence aggressive behavior by altering the neural processing of facial threat signals. However, this has not been investigated in direct social interactions. Here, we explored the joint impact of testosterone, cortisol, and brain reactivity to anger expressions on women's reactive aggression in the Social Threat Aggression Paradigm (STAP). The STAP is a competitive reaction time task in which the purported opponent displays either an angry or a neutral facial expression at the beginning of each trial and delivers increasingly loud sound blasts to the participants, successfully provoking them. Strikingly, salivary testosterone at scan-time was negatively related to both aggression and basolateral amygdala (BLA) reactivity to angry faces, whereas cortisol had no effect. When the opponent looked angry, BLA-orbitofrontal coupling was reduced, and BLA reactivity was positively related to aggression. The latter relationship was fully mediated by bilateral superior temporal gyrus (STG) activation. Our results thus support previous neurobiological models of aggression, and extend them by demonstrating that fast amygdala responses to threat modulate STG activity in order to favor aggressive retaliation. Furthermore, our study agrees with recent evidence underscoring a fear-reducing and strategically prosocial effect of testosterone on human social behavior

    Expression of hypoxia-inducible factor 1α in thyroid carcinomas

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    Hypoxia-inducible factor 1α (HIF-1α) is upregulated by hypoxia and oncogenic signalling in many solid tumours. Its regulation and function in thyroid carcinomas are unknown. We evaluated the regulation of HIF-1α and target gene expression in primary thyroid carcinomas and thyroid carcinoma cell lines (BcPAP, WRO, FTC-133 and 8505c). HIF-1α was not detectable in normal tissue but was expressed in thyroid carcinomas. Dedifferentiated anaplastic tumours (ATCs) exhibited high levels of nuclear HIF-1α staining. The HIF-1 target glucose transporter 1 was expressed to a similar level in all tumour types, whereas carbonic anhydrase-9 was significantly elevated in ATCs. In vitro studies revealed a functionally active HIF-1α pathway in thyroid cells with transcriptional activation observed after graded hypoxia (1% O2, anoxia) or treatment with a hypoxia mimetic cobalt chloride. High basal and hypoxia-induced expression of HIF-1α in FTC-133 cells that harbour a phosphatase and tensin homologue (PTEN) mutation was reduced by introduction of wild-type PTEN. Similarly, pharmacological inhibition of the phosphoinositide 3-kinase (PI3K) pathway using LY294002 inhibited HIF-1α and HIF-1α targets in all cell lines, including those with B-RAF mutations (BcPAP and 8505c). In contrast, the effects of inhibition of the RAF/MEK/extracellular signal-regulated kinase pathway were restricted by environmental condition and B-RAF mutation status. HIF-1 is functionally expressed in thyroid carcinomas and is regulated not only by hypoxia but also via growth factor signalling pathways and, in particular, the PI3K pathway. Given the strong association of HIF-1α with an aggressive disease phenotype and therapeutic resistance, this pathway may be an attractive target for improved therapy in thyroid carcinomas

    Atrial natriuretic factor

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    The discovery of the first well-defined natriuretic hormone, the Atrial Natriuretic Factor (ANF), has prompted research on its impact on volume regulation in health and disease. The natriuretic, diuretic, and smooth muscle-relaxing properties suggest an important role of this novel hormone in pathophysiological states with sodium or volume retention, such as congestive heart failure or cirrhosis of the liver. Investigations on the implications of ANF in liver disease have been performed for little more than 1 year, and results are still controversial in many respects. At present, it seems very likely that there is no absolute deficiency of plasma ANF in patients with cirrhosis. Moreover, elevated plasma levels in cirrhotics with ascites have been reported by several groups. However, as yet, a molecular characterization of this increased immunoreactivity is still lacking. There is disagreement on the reduced release of and renal response to ANF in subgroups of cirrhotics; however, stimulus-response-coupling might be impaired. Further studies are needed to elucidate the pathophysiological implications and therapeutical potential of ANF in patients with chronic liver disease

    Bidding for Success? Impacts of the European Capital of Culture Bid

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    The increasingly multifaceted nature of event impacts makes them even more attractive as a potential solution to a range of urban and regional problems. As a result, competition to stage major cultural and sporting events is intensifying, and the cost of bidding is also rising. Given that such bidding processes only produce one winner, this means that a growing number of disappointed cities have to justify the costs of bidding for major events. In this context, we analyse the bidding process for the European Capital of Culture in the Netherlands (2018) and its impacts on local social structures. In particular the article focuses on the less tangible, non-economic effects of bidding for events, establishing a framework based on network formation, public support for the bidding process and social cohesion. The conclusions point to the key role of sociality and networking for events, which should therefore be developed throughout the bidding process for successful impacts, either the event is won or not
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