Low-Speed Flight Dynamic Tests and Analysis of the Orion Crew Module Drogue Parachute System

A test of a dynamically scaled model of the NASA Orion Crew Module (CM) with drogue parachutes was conducted in the NASA-Langley 20-Foot Vertical Spin Tunnel. The primary test objective was to assess the ability of the Orion Crew Module drogue parachute system to adequately stabilize the CM and reduce angular rates at low subsonic Mach numbers. Two attachment locations were tested: the current design nominal and an alternate. Experimental results indicated that the alternate attachment location showed a somewhat greater tendency to attenuate initial roll rate and reduce roll rate oscillations than the nominal location. Comparison of the experimental data to a Program To Optimize Simulated Trajectories (POST II) simulation of the experiment yielded results for the nominal attachment point that indicate differences between the low-speed pitch and yaw damping derivatives in the aerodynamic database and the physical model. Comparisons for the alternate attachment location indicate that riser twist plays a significant role in determining roll rate attenuation characteristics. Reevaluating the impact of the alternate attachment points using a simulation modified to account for these results showed significantly reduced roll rate attenuation tendencies when compared to the original simulation. Based on this modified simulation the alternate attachment point does not appear to offer a significant increase in allowable roll rate over the nominal configuration

Identität durch Technik: wie soziale Identität und Gruppenidentität im soziotechnischen Ensemble von Ego-Shooterclans entstehen

Die Arbeit widmet sich der Frage, wie soziale Identität und Gruppenidentität in der Ego-Shooterclanszene entstehen und welche Rolle den unterschiedlichen Elementen des soziotechnischen Ensembles dabei zukommt. Nach einer Problematisierung dieser Frage in Kapitel 1 wird der Autor im zweiten Kapitel in besonders verkürzter Form die von ihm verwendeten Theorien vorstellen. Er geht dabei davon aus, dass soziale Identität und Gruppenidentität als antagonistische Kräfte in Gruppen wirken, die aber gerade deshalb die Handlungsfähigkeit, sowie die Kohäsion der Gruppe ermöglichen. Im dritten Kapitel präsentiert der Autor die Ergebnisse der Auswertung zweier großer Gruppeninterviews, die er mit zwei verschiedenen Clans geführt hat, sowie die Auswertung der Analyse von 20 Clanwebsites. Er wird herausarbeiten, an welchen Stellen in der Clanszene sich die verschiedenen identitätsstiftenden Faktoren zeigen, in wiefern sie sich derart wieder finden, wie es von den unterschiedlichen Identitätstheoretikern beschrieben wird. Im Schlussteil werden die Ergebnisse noch einmal zusammengefasst und auf die Fragestellung rückbezogen

Comparison of Fas(Apo-1/CD95)- and perforin-mediated cytotoxicity in primary T lymphocytes

Cytolytic T lymphocytes kill target cells by two independent cytolytic mechanisms. One pathway depends on the polarized secretion of granule-stored proteins including perform and granzymes, causing target cell death through membrane and DNA damage. The second cytolytic effector system relies on the interaction of the Fas ligand (FasL) on the effector cell with its receptor (Fas) on the target cell, leading to apoptotic cell death. Using mixed lymphocyte culture (MLC)-derived primary T lymphocytes of perforin-knockout and gld (with non-functional FasL) mice, the molecular basis of the two killing mechanisms was compared. The activity of both pathways was dependent on extracellular Ca2+. Incubation of MLC-stimulated primary T cells with protein synthesis inhibitors prior to TCR triggering impaired FasL cell surface expression and abolished cytolytic activity, although the cells exhibited an intracellular pool of FasL. The perforin-dependent mechanism induced cell death more rapidly, although both pathways ultimately showed similar killing efficiencies. Both pathways induced comparable levels of DNA degradation, but Fas-induced membrane damage was less pronounced. We conclude that upon TCR triggering FasL may be recruited in part from pre-existing intracellular stores. However, efficient induction of target cell death still depends on the continuous biosynthesis of FasL molecule

Lymphotoxin α revisited: general features and implications in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease affecting synovial joints. Therapies blocking tumor necrosis factor-alpha (TNFα) are now routinely used in the management of RA. However, a significant number of patients with RA do not respond or develop resistance to anti-TNF therapies, and the participation of other cytokines in RA pathogenesis has been reported as well. Lymphotoxin alpha (LTα) is the closest homolog to TNFα and has been implicated in inflammation and autoimmunity since its original description in 1968. In spite of that, little is known about the role of LTα in RA or the potential of blocking this cytokine as an alternative therapeutic approach. In this review, we aim to summarize the general features of LTα and what is currently known about its participation in RA

Apoptosis is not the major death mechanism induced by celecoxib on rheumatoid arthritis synovial fibroblasts

Synovial hyperplasia in rheumatoid arthritis (RA) has been associated with apoptosis deficiency of RA fibroblast-like synoviocytes (FLSs). Celecoxib is a non-steroidal anti-inflammatory drug that has been demonstrated to induce apoptosis in some cellular systems. We have therefore examined the dose- and time-dependent effects of celecoxib on RA FLS viability. Treatment of RA FLSs with celecoxib for 24 hours reduced their viability in a dose-dependent manner. Analysis of celecoxib-treated RA FLSs for their content of apoptotic and necrotic cells by Annexin V staining and TO-PRO-3 uptake displayed only few apoptotic cells. Caspase 3, a key mediator of apoptosis, was not activated in celecoxib-treated RA FLSs, and the presence of specific caspase 3 or pan-caspase inhibitors did not affect celecoxib-induced cell death. Moreover, we could not detect other signs of apoptosis, such as cleavage of poly(ADP-ribose) polymerase, caspase 8 or 9, or DNA fragmentation. We therefore conclude that apoptosis is not the major death pathway in celecoxib-treated RA FLSs

Potential role of APRIL as autocrine growth factor for megakaryocytopoiesis

Abstract A proliferation-inducing ligand (APRIL) is a new tumor necrosis factor family member implicated in tumor cell proliferation. We investigated the role of APRIL in megakaryocytopoiesis, a developmental hematopoietic process responsible for progenitor cell differentiation to megakaryoblasts and megakaryocytes, leading to platelet formation. APRIL is not expressed in CD34+ progenitor cells from healthy donors, but it is massively up-regulated during the proliferative phase of megakaryocytic cell differentiation. Exogenous APRIL expression in primary cells increases megakaryocytic cell growth, suggesting that APRIL acts as a proliferative factor in megakaryocytopoiesis. More importantly, neutralization of endogenous APRIL was able to dramatically reduce megakaryocyte expansion and platelet production. Thus, our data provide evidence that APRIL acts as a growth factor for terminal megakaryocytopoiesis and may promote physiologic platelet production

La cultura científica, la percepción pública y el caso de la biotecnología

Ponencia presentada en el seminario "La cultura científica en la sociedad de la información" (Oviedo, 30 de mayo a de junio de 2002), organizado por el Observatorio de Cultura Científica de la Universidad de Oviedo.Peer reviewe

High levels of memory B cells are associated with response to a first tumor necrosis factor inhibitor in patients with rheumatoid arthritis in a longitudinal prospective study

Tumor necrosis factor inhibitor (TNFi) therapy is effective for rheumatoid arthritis (RA). Some reports suggested that the therapy affects B-cell homeostasis. We studied the effect of TNFi therapy on the distribution of peripheral B-cell subsets and elucidated B-cell-related biomarkers to predict the TNFi response. Peripheral B cells were analyzed for expression of CD19, CD27, CD38, and IgD in 31 healthy donors and 96 RA patients, including 21 who were followed 3 months after TNFi introduction. Treatment with steroids significantly altered the distribution of B-cell subsets. After adjustment for age, gender and steroid dose, patients with RA had similar B-cell subset proportions as controls. B-cell subset distribution did not differ by use of TNFi at baseline or before and after TNFi introduction. TNFi responders (according to European League Against Rheumatism criteria) at 3 months had significantly higher proportion of CD27+ memory B cells at baseline, and >= 26% CD27+ cells at inclusion was associated with a relative risk of 4.9 (1.3 to 18.6) of responding to TNFi treatment. CD27+ cells produced 3 times more TNFalpha than did naive B cells, and were correlated with interferon-gamma produced from CD4+ cells in patients without TNFi treatment. In patients with RA, high levels of baseline memory B cells were associated with response to TNFi, which may be related to TNFalpha-dependent activation of the T helper cell type 1 pathwa

(Un-)Sicherheitsgefühle und subjektive Sicherheit im urbanen Raum

(UN-)SICHERHEITSGEFÜHLE UND SUBJEKTIVE SICHERHEIT IM URBANEN RAUM Berliner Forum Gewaltprävention (Rights reserved) (-) Issue73 Gewaltprävention in der Schule (Rights reserved) ( - ) Issue72 Rechte Gewalt und Prävention (Rights reserved) ( - ) Issue71 Gesamtkonzept "Berlin gegen Gewalt" (Rights reserved) ( - ) Issue70,2 (Un-)Sicherheitsgefühle und subjektive Sicherheit im urbanen Raum (Rights reserved) ( - ) Issue70,1 Kiezorientierte Gewalt- und Kriminalitätsprävention in Berlin (Rights reserved) ( - ) Issue69 Interdisziplinäre Beiträge zu Radikalisierung (Rights reserved) ( - ) Issue67,5 Jugendgewalt in Marzahn-Nord (Rights reserved) ( - ) Issue67,4 Professioneller Umgang mit Opfern von Straftaten als polizeiliche Kernkompetenz (Rights reserved) ( - ) Issue67,1 "Auf die Plätze!" - kiezorientierte Gewaltprävention im Sozialraum (Rights reserved) ( - ) Issue65 Handreichung für Lehrkräfte: Reduktion von feindseligen Zuschreibungen in sozialen Situationen (Rights reserved) ( - ) Issue63 Berliner Landesprogramm Radikalisierungsprävention (Rights reserved) ( - ) Issue61 Die Praxis der Prävention (Rights reserved) ( - ) Issue60 Gemeinsam gegen Gewalt (Rights reserved) ( - ) Issue59 Berliner Landesprogramm Radikalisierungsprävention (Rights reserved) ( - ) Issue57 Prävention auf dem Prüfstand (Rights reserved) ( - ) Issue55 Lösungsfokussierte Paarberatung bei häuslicher Gewalt (Rights reserved) ( - ) Issue54 Gewalterfahrung und Lebenslage (Rights reserved) ( - ) Issue52 Antisemitismus als Problem und Symbol (Rights reserved) ( - ) Issue52 Antisemitismus als Problem und Symbol (Rights reserved) ( - ) Issue51 Handreichung Selbstevaluation (Rights reserved) ( - ) Issue50 Das Rechtskundepaket (Rights reserved) ( - ) Issue49 Dokumentation des Berlin-Brandenburger "Fachtages gegen Rechtsextremismus/Kommunale Netzwerke, Beratung, Bildung und Aufklärung" (Rights reserved) ( - ) Issue48 Schöne neue Welt - total vernetzt! Fluch oder Segen? (Rights reserved) ( - ) Issue47 Die Praxis von Vorurteils- und Gewaltprävention in zwei Berliner Quartieren (Rights reserved) ( - ) Issue46 Brücken bauen - Respekt fördern - Vielfalt gestalten (Rights reserved) ( - ) Issue45 Jugendliche als Opfer und Täter von Gewalt in Berlin (Rights reserved) ( - ) Issue44 Haftverläufe und Ausblicke auf die Legalbewährung junger Mehrfachtäter [Intensivtäter in Berlin ; 3] (Rights reserved) ( - ) Issue43 Ergebnisse der wissenschaftlichen Begleitung von Modellprojekten der Landeskommission Berlin gegen Gewalt (Rights reserved) ( - ) Issue42 Analyse der Gewalt am 1. Mai 2009 in Berlin (Rights reserved) ( - ) Issue41 Evaluation und Qualitätsentwicklung in der Gewalt- und Kriminalitätsprävention (Rights reserved) ( - ) Issue40 Schnittstellenanalyse zum Themenkomplex Sexuelle Gewalt (Rights reserved) ( - ) Issue39 Was tun gegen Rechte Gewalt? (Rights reserved) ( - ) Issue38 Jugendgewalt: Was leisten Trainings, Kurse und Seminare? (Rights reserved) ( - ) Issue37 Intoleranz betäubt die Sinne (Rights reserved) ( - ) Issue36 Kinder- und Jugenddelinquenz (Rights reserved) ( - ) Issue35 Dokumentation des 8. Berliner Präventionstages (Rights reserved) ( - ) Issue34 Schlagwort Integration (Rights reserved) ( - ) Issue33 Ergebnisse der Befragung von "Intensivtätern" sowie der Auswertung ihrer Schulakten [Intensivtäter in Berlin ; 2] (Rights reserved) ( - ) Issue32 Männliche Sozialisation und Gewalt (Rights reserved) ( - ) Issue31 Das ist mir fremd. Das war mir fremd. Das kenne ich. (Rights reserved) ( - ) Issue30 Berliner Projekte gegen Rechtsextremismus (Rights reserved) ( - ) Issue29 Dokumentation des 7. Berliner Präventionstages: Psychische Gewalt (Rights reserved) ( - ) Issue28 Gewalt von Jungen, männlichen Jugendlichen und jungen Männern mit Migrationshintergrund in Berlin (Rights reserved) ( - ) Issue27 Das jugendliche Opfer (Rights reserved) ( - ) Issue26 Ergebnisse der Analyse von "Intensivtäterakten" der Staatsanwaltschaft Berlin [Intensivtäter in Berlin ; 1] (Rights reserved) ( - ) Issue25 Häusliche Gewalt gegen Migrantinnen (Rights reserved) ( - ) Issue24 Dokumentation des 6. Berliner Präventionstages (Rights reserved) ( - ) Issue23 Plakatwettbewerb der Landeskommission Berlin gegen Gewalt (Rights reserved) ( - ) Issue22 Themenschwerpunkt: Soziales Lernen in der Schule (Rights reserved) ( - ) Issue21 Dokumentation des 5. 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