127 research outputs found

    Full-scale semispan tests of a business-jet wing with a natural laminar flow airfoil

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    A full-scale semispan model was investigated to evaluate and document the low-speed, high-lift characteristics of a business-jet class wing that utilized the HSNLF(1)-0213 airfoil section and a single-slotted flap system. Also, boundary-layer transition effects were examined, a segmented leading-edge droop for improved stall/spin resistance was studied, and two roll-controlled devices were evaluated. The wind-tunnel investigation showed that deployment of single-slotted, trailing-edge flap was effective in providing substantial increments in lift required for takeoff and landing performance. Fixed-transition studies to investigate premature tripping of the boundary layer indicated no adverse effects in lift and pitching-moment characteristics for either the cruise or landing configuration. The full-scale results also suggested the need to further optimize the leading-edge droop design that was developed in the subscale tests

    Effiziente Datenanalyse

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    Die Fähigkeit zur Analyse großer Datenmengen sowie das extrahieren wichtiger Erkenntnisse daraus, sind in der modernen Unternehmenswelt ein entscheidender Wettbewerbsvorteil geworden. Umso wichtiger ist es, dabei vor allem nachvollziehbar, reproduzierbar und effizient vorzugehen. Der Beitrag stellt mit dem Instrument der skriptbasierten Datenanalyse eine Möglichkeit vor, um diesen Anforderungen gerecht zu werden

    Wind tunnel results of the high-speed NLF(1)-0213 airfoil

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    Wind tunnel tests were conducted to evaluate a natural laminar flow airfoil designed for the high speed jet aircraft in general aviation. The airfoil, designated as the High Speed Natural Laminar Flow (HSNLF)(1)-0213, was tested in two dimensional wind tunnels to investigate the performance of the basic airfoil shape. A three dimensional wing designed with this airfoil and a high lift flap system is also being evaluated with a full size, half span model

    Novel tempeh (fermented soyabean) isoflavones inhibit in vivo angiogenesis in the chicken chorioallantoic membrane assay

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    Anti-angiogenic strategies are emerging as an important tool for the treatment of cancer and inflammatory diseases. In the present investigation we isolated several isoflavones from a tempeh (fermented soyabean) extract. The isolated isoflavones were identified as 5,7,4′-trihydroxyisoflavone (genistein), 7,4′-dihydroxyisoflavone (daidzein), 6,7,4′-trihydroxyisoflavone (factor 2), 7,8,4′-trihydroxyisoflavone (7,8,4′-TriOH) and 5,7,3′,4′-tetrahydroxyisoflavone (orobol). The effects on angiogenesis of these isoflavones were evaluated in the chicken chorioallantoic membrane assay; their capacity to inhibit vascular endothelial growth factor-induced endothelial cell proliferation and expression of the Ets 1 transcription factor, known to be implicated in the regulation of new blood vessel formation, were also investigated. We found that all isoflavones inhibited angiogenesis, albeit with different potencies. Compared with negative controls, which slightly inhibited in vivo angiogenesis by 6·30 %, genistein reduced angiogensis by 75·09 %, followed by orobol (67·96 %), factor 2 (56·77 %), daidzein (48·98 %) and 7,8,4′-TriOH (24·42 %). These compounds also inhibited endothelial cell proliferation, with orobol causing the greatest inhibition at lower concentrations. The isoflavones also inhibited Ets 1 expression, providing some insight into the molecular mechanisms of their action. Furthermore, the chemical structure of the different isoflavones suggests a structure-activity relationship. Our present findings suggest that the new isoflavones might be added to the list of low molecular mass therapeutic agents for the inhibition of angiogenesi

    Erfassung, Bewertung und Minderung von Treibhausgasemissionen des deutschen Agrar- und Ernährungssektors: Studie im Auftrag des Bundesministeriums für Ernährung, Landwirtschaft und Verbraucherschutz

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    In dieser Studie werden Treibhausgasemissionen (THG) aus der deutschen Agrar- und Ernährungswirtschaft analysiert und Möglichkeiten zu ihrer Reduzierung erörtert. Darüber hinaus wird die Eignung von Ökobilanzen für die Bewertung von Produktionsverfahren und Produkten untersucht. In Kapitel 2 werden theoretische Grundlagen für die Umsetzung von Klimaschutzpolitiken erörtert. Als Bilanzierungs- und Analysemethoden werden die Emissionsberichterstattung, die umweltökonomischen Gesamtrechnungen, Ökobilanzen (Life Cycle Assessment) und Carbon Footprints vorgestellt. Es folgt in Kapitel 3 eine Analyse der THG-Emissionen des deutschen Agrar- und Ernährungssektors nach Quellgruppen der Klimaberichterstattung sowie in Bezug auf Produktionsprozesse und erzeugte Agrargüter. Anschließend wird in Kapitel 4 der Stand des Wissens zu kumulierten THG-Emissionen der Ernährungswirtschaft bis hin zum Konsum dargestellt. In Kapitel 5 wird eine Übersicht über mögliche technische und organisatorische Maßnahmen zur Verringerung von THG-Emissionen im Agrarsektor sowie Optionen für das individuelle Verbraucherverhalten gegeben. Erste Hinweise, wie die Politik die Realisierung wirksamer Klimaschutzmaßnahmen unterstützen kann, werden in Kapitel 6 vorgestellt. Als Klimaschutzmaßnahmen im Bereich Landwirtschaft und Landnutzung werden die Verbesserung der Stickstoffausnutzung, die Verwendung von Gülle in Biogasanlagen, die Beschränkung der Umwandlung von Grünland in Ackerland und die Renaturierung von Niedermooren hervorgehoben. Im Bereich Ernährung und Verbraucherverhalten sollte der Wissenstransfer im Mittelpunkt stehen. Produktspezifische Klima-Labels für Lebensmittel werden als ungeeignet angesehen. Bezüglich der Politiken zur Förderung der Bioenergie wird eine Ausrichtung auf Technologien mit den kostengünstigsten Klimaschutzbeiträgen empfohlen. Die Studie schließt mit einem kurzen Ausblick auf die zukünftige Forschungsarbeit des vTI im Bereich Klimaschutz und Ökobilanzierung. -- This study addresses the emissions of greenhouse gases (GHG) from the German agri-food sector, and options for mitigation. Further, the suitability of eco-balances for valuation of processes and products is explored. Chapter 2 refers to the theoretical basis of climate protection, and, as tools for analysis, GHG accounting, the System of Integrated Environmental and Economic Accounting (SEEA), eco-balances (Life Cycle Analysis) and carbon footprints are presented. In chapter 3, agricultural GHG emissions are analysed by GHG sources, processes and food products, and in chapter 4 the state of knowledge of emissions stemming from food processing, retail and households is portrayed. Chapter 5 introduces to technical and organisational mitigation options in agriculture and regarding consumer decisions. First hints how policy might support GHG mitigation are presented in chapter 6. The study closes with an outlook on future research activities of vTI in the area of climate protection and eco-balancing.Klimawandel,Treibhausgase,Landwirtschaft,Kohlenstoff Fußabdruck,Climate Change,Greenhouse gases,Agriculture,Carbon footprint

    PhenoFam-gene set enrichment analysis through protein structural information

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    <p>Abstract</p> <p>Background</p> <p>With the current technological advances in high-throughput biology, the necessity to develop tools that help to analyse the massive amount of data being generated is evident. A powerful method of inspecting large-scale data sets is gene set enrichment analysis (GSEA) and investigation of protein structural features can guide determining the function of individual genes. However, a convenient tool that combines these two features to aid in high-throughput data analysis has not been developed yet. In order to fill this niche, we developed the user-friendly, web-based application, PhenoFam.</p> <p>Results</p> <p>PhenoFam performs gene set enrichment analysis by employing structural and functional information on families of protein domains as annotation terms. Our tool is designed to analyse complete sets of results from quantitative high-throughput studies (gene expression microarrays, functional RNAi screens, <it>etc</it>.) without prior pre-filtering or hits-selection steps. PhenoFam utilizes Ensembl databases to link a list of user-provided identifiers with protein features from the InterPro database, and assesses whether results associated with individual domains differ significantly from the overall population. To demonstrate the utility of PhenoFam we analysed a genome-wide RNA interference screen and discovered a novel function of plexins containing the cytoplasmic RasGAP domain. Furthermore, a PhenoFam analysis of breast cancer gene expression profiles revealed a link between breast carcinoma and altered expression of PX domain containing proteins.</p> <p>Conclusions</p> <p>PhenoFam provides a user-friendly, easily accessible web interface to perform GSEA based on high-throughput data sets and structural-functional protein information, and therefore aids in functional annotation of genes.</p

    How to Minimize the Attack Rate during Multiple Influenza Outbreaks in a Heterogeneous Population

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    <div><h3>Background</h3><p>If repeated interventions against multiple outbreaks are not feasible, there is an optimal level of control during the first outbreak. Any control measures above that optimal level will lead to an outcome that may be as sub-optimal as that achieved by an intervention that is too weak. We studied this scenario in more detail.</p> <h3>Method</h3><p>An age-stratified ordinary-differential-equation model was constructed to study infectious disease outbreaks and control in a population made up of two groups, adults and children. The model was parameterized using influenza as an example. This model was used to simulate two consecutive outbreaks of the same infectious disease, with an intervention applied only during the first outbreak, and to study how cumulative attack rates were influenced by population composition, strength of inter-group transmission, and different ways of triggering and implementing the interventions. We assumed that recovered individuals are fully immune and the intervention does not confer immunity.</p> <h3>Results/Conclusion</h3><p>The optimal intervention depended on coupling between the two population sub-groups, the length, strength and timing of the intervention, and the population composition. Population heterogeneity affected intervention strategies only for very low cross-transmission between groups. At more realistic values, coupling between the groups led to synchronization of outbreaks and therefore intervention strategies that were optimal in reducing the attack rates for each subgroup and the population overall coincided. For a sustained intervention of low efficacy, early intervention was found to be best, while at high efficacies, a delayed start was better. For short interventions, a delayed start was always advantageous, independent of the intervention efficacy. For most scenarios, starting the intervention after a certain cumulative proportion of children were infected seemed more robust in achieving close to optimal outcomes compared to a strategy that used a specified duration after an outbreak’s beginning as the trigger.</p> </div

    Specific treatment of problems of the spine (STOPS): design of a randomised controlled trial comparing specific physiotherapy versus advice for people with subacute low back disorders

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    <p>Abstract</p> <p>Background</p> <p>Low back disorders are a common and costly cause of pain and activity limitation in adults. Few treatment options have demonstrated clinically meaningful benefits apart from advice which is recommended in all international guidelines. Clinical heterogeneity of participants in clinical trials is hypothesised as reducing the likelihood of demonstrating treatment effects, and sampling of more homogenous subgroups is recommended. We propose five subgroups that allow the delivery of specific physiotherapy treatment targeting the pathoanatomical, neurophysiological and psychosocial components of low back disorders. The aim of this article is to describe the methodology of a randomised controlled trial comparing specific physiotherapy treatment to advice for people classified into five subacute low back disorder subgroups.</p> <p>Methods/Design</p> <p>A multi-centre parallel group randomised controlled trial is proposed. A minimum of 250 participants with subacute (6 weeks to 6 months) low back pain and/or referred leg pain will be classified into one of five subgroups and then randomly allocated to receive either physiotherapy advice (2 sessions over 10 weeks) or specific physiotherapy treatment (10 sessions over 10 weeks) tailored according to the subgroup of the participant. Outcomes will be assessed at 5 weeks, 10 weeks, 6 months and 12 months following randomisation. Primary outcomes will be activity limitation measured with a modified Oswestry Disability Index as well as leg and back pain intensity measured on separate 0-10 Numerical Rating Scales. Secondary outcomes will include a 7-point global rating of change scale, satisfaction with physiotherapy treatment, satisfaction with treatment results, the Sciatica Frequency and Bothersomeness Scale, quality of life (EuroQol-5D), interference with work, and psychosocial risk factors (Orebro Musculoskeletal Pain Questionnaire). Adverse events and co-interventions will also be measured. Data will be analysed according to intention to treat principles, using linear mixed models for continuous outcomes, Mann Whitney U tests for ordinal outcomes, and Chi-square, risk ratios and risk differences for dichotomous outcomes.</p> <p>Discussion</p> <p>This trial will determine the difference in outcomes between specific physiotherapy treatment tailored to each of the five subgroups versus advice which is recommended in guidelines as a suitable treatment for most people with a low back disorder.</p> <p>Trial registration</p> <p>Australia and New Zealand Clinical Trials Register (ANZCTR): <a href="http://www.anzctr.org.au/ACTRN12609000834257.aspx">ACTRN12609000834257</a>.</p
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