285 research outputs found

    Self streamlining wind tunnel: Low speed testing and transonic test section design

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    Comprehensive aerodynamic data on an airfoil section were obtained through a wide range of angles of attack, both stalled and unstalled. Data were gathered using a self streamlining wind tunnel and were compared to results obtained on the same section in a conventional wind tunnel. The reduction of wall interference through streamline was demonstrated

    Predictive wall adjustment strategy for two-dimensional flexible walled adaptive wind tunnel: A detailed description of the first one-step method

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    Following the realization that a simple iterative strategy for bringing the flexible walls of two-dimensional test sections to streamline contours was too slow for practical use, Judd proposed, developed, and placed into service what was the first Predictive Strategy. The Predictive Strategy reduced by 75 percent or more the number of iterations of wall shapes, and therefore the tunnel run-time overhead attributable to the streamlining process, required to reach satisfactory streamlines. The procedures of the Strategy are embodied in the FORTRAN subroutine WAS (standing for Wall Adjustment Strategy) which is written in general form. The essentials of the test section hardware, followed by the underlying aerodynamic theory which forms the basis of the Strategy, are briefly described. The subroutine is then presented as the Appendix, broken down into segments with descriptions of the numerical operations underway in each, with definitions of variables

    Studies of self streamlining wind tunnel real and imaginary flows

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    Testing in the low speed flexible walled tunnel in an effort to explain the reasons for data discrepancies at high angles of attack are presented. Automated transonic test sections were developed. The flexible walled tunnel was used in a new operating mode to a generated curved flow around the airfoil, allowing the extraction of purely rotary derivatives. Some straight wall, low speed pressure data, for wall and model, which is used for checking interference correction methods were reported. Computer software which includes an old streamlining algorithm and a prediction algorithm was examined

    Streamlining the walls of an empty two-dimensional flexible-walled test section

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    The techniques used to find aerodynamically straight wall contours in a test section of a transonic wind tunnel are discussed. The walls were defined as aerodynamically straight up to Mach 0.9

    Model and boundary aerodynamic data from high blockage two-dimensional airfoil tests in a shallow unstreamlined transonic flexible walled test section

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    Data for a NACA 0012-64 airfoil at Mach numbers of 0.3, 0.5, and 0.7 with the test section flexible walls set in the "straight" position are presented because they may prove useful in the development of wind tunnel correction techniques

    The effects of cognitive-behavioural therapy on mood-related ruminative response style in depressed adolescents

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    <p>Abstract</p> <p>Background</p> <p>A mood-related ruminative response style increases the risk of onset and persistence of depression. This preliminary study investigated whether, in depressed adolescents, cognitive-behaviour therapy reduces mood-related ruminative response style. Whether specific factors within the rumination scale were differentially affected by CBT is also reported.</p> <p>Methods</p> <p>26 depressed adolescents were randomised to receiving serotonin-specific reuptake inhibitor antidepressants (SSRI) plus psychosocial treatment as usual or SSRI and psychosocial treatment as usual plus CBT. Ruminative response style and depressive symptoms were measured at baseline and after 30 weeks of treatment, with the Responses to Depression Questionnaire and Mood and Feelings Questionnaire.</p> <p>Results</p> <p>There were significantly greater reductions in ruminations in the CBT group compared to the non-CBT group (<it>p </it>= .002). There was no significant difference in the reduction in self-reported depressive symptoms between the groups. Rumination was reduced to levels of never-depressed controls in adolescents who had recovered from depression and received CBT. There were greater falls in the CBT group in the more pathological 'brooding' factor of rumination.</p> <p>Conclusion</p> <p>These findings suggest that adding CBT to SSRI medication in the presence of active clinical care causes a greater reduction in mood-related ruminative response style in depressed adolescents. This may reduce the risk of future relapse.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCNT83809224.</p

    Conserved Usage of Alternative 5′ Untranslated Exons of the GATA4 Gene

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    BACKGROUND:GATA4 is an essential transcription factor required for the development and function of multiple organs. Despite this important role, our knowledge of how the GATA4 gene is regulated remains limited. To better understand this regulation, we characterized the 5' region of the mouse, rat, and human GATA4 genes. METHODOLOGY/PRINCIPAL FINDINGS:Using 5' RACE, we identified novel transcription start sites in all three species. GATA4 is expressed as multiple transcripts with varying 5' ends encoded by alternative untranslated first exons. Two of these non-coding first exons are conserved between species: exon 1a located 3.5 kb upstream of the GATA4 ATG site in exon 2, and a second first exon (exon 1b) located 28 kb further upstream. Expression of both mRNA variants was found in all GATA4-expressing organs but with a preference for the exon 1a-containing transcript. The exception was the testis where exon 1a- and 1b-containing transcripts were similarly expressed. In some tissues such as the intestine, alternative transcript expression appears to be regionally regulated. Polysome analysis suggests that both mRNA variants contribute to GATA4 protein synthesis. CONCLUSIONS/SIGNIFICANCE:Taken together, our results indicate that the GATA4 gene closely resembles the other GATA family members in terms of gene structure where alternative first exon usage appears to be an important mechanism for regulating its tissue- and cell-specific expression

    Neuroactive steroids in depression and anxiety disorders: Clinical studies

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    Certain neuroactive steroids modulate ligand-gated ion channels via non-genomic mechanisms. Especially 3 alpha-reduced pregnane steroids are potent positive allosteric modulators of the gamma-aminobutyric acid type A (GABA(A)) receptor. During major depression, there is a disequilibrium of 3 alpha-reduced neuroactive steroids, which is corrected by clinically effective pharmacological treatment. To investigate whether these alterations are a general principle of successful antidepressant treatment, we studied the impact of nonpharmacological treatment options on neuroactive steroid concentrations during major depression. Neither partial sleep deprivation, transcranial magnetic stimulation, nor electroconvulsive therapy affected neuroactive steroid levels irrespectively of the response to these treatments. These studies suggest that the changes in neuroactive steroid concentrations observed after antidepressant pharmacotherapy more likely reflect distinct pharmacological properties of antidepressants rather than the clinical response. In patients with panic disorder, changes in neuroactive steroid composition have been observed opposite to those seen in depression. However, during experimentally induced panic induction either with cholecystokinine-tetrapeptide or sodium lactate, there was a pronounced decline in the concentrations of 3 alpha-reduced neuroactive steroids in patients with panic disorder, which might result in a decreased GABAergic tone. In contrast, no changes in neuroactive steroid concentrations could be observed in healthy controls with the exception of 3 alpha,5 alpha-tetrahydrodeoxycorticosterone. The modulation of GABA(A) receptors by neuroactive steroids might contribute to the pathophysiology of depression and anxiety disorders and might offer new targets for the development of novel anxiolytic compounds. Copyright (c) 2006 S. Karger AG, Basel

    Development of a gamified cognitive training app “Social Brain Train” to enhance adolescent mental health: a participatory design study protocol

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    Background: Adolescence is a sensitive period for the onset of mental health disorders. Effective, easy-to-disseminate, scalable prevention and early interventions are urgently needed. Affective control has been proposed as a potential target mechanism. Training affective control has been shown to reduce mental health symptoms and improve emotion regulation. However, uptake and adherence to such training by adolescents has been low. Thus, the current study aims to receive end user (i.e., adolescents) feedback on a prototype of a novel app-based gamified affective control training program, the Social Brain Train. Methods: The proposed study aims to recruit participants aged 13-16 years old (N = 20) to provide user feedback on the Social Brain Train app. The first group of participants (n = 5) will complete an online questionnaire assessing demographics, symptoms of depression and anxiety, social rejection sensitivity and attitudes toward the malleability of cognition and mental health. They will complete two tasks assessing cognitive capacity and interpretation bias. Participants will be then be invited to an online group workshop, where they will be introduced to the app. They will train on the app for three days, and following app usage, participants will complete the aforementioned measures again, as well as provide ratings on app content, and complete a semi-structured interview to obtain in-depth user feedback, which will be used to inform modifications to the app. Following these modifications, a second group of participants (n = 15) will follow the same procedure, except they will train on the app for 14 days. Feedback from both groups of participants will be used to inform the final design. Conclusions: By including young people in the design of the Social Brain Train app, the proposed study will help us to develop a novel mental health intervention that young people find engaging, acceptable, and easy-to-useSavannah Minihan, Annabel Songco, Jack L. Andrews, Karina Grunewald, Aliza Werner-Seidler, Sarah-Jayne Blakemore, Helen Christensen, Elaine Fox, Ian M. Goodyer, William Raffe, Susanne Schweize
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