731 research outputs found

    Baseline Severity as Predictor of Change in St George's Respiratory Questionnaire Scores in Trials of Long-acting Bronchodilators with COPD Patients.

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    Background: In trials oflong-acting bronchodilators, health status is an important trial outcome, however the influence of baseline severity on response measured by St George's Respiratory Questionnaire (SGRQ) is not known. We have compared SGRQ changes between patients with chronic obstructive pulmonary disease (COPD) of mild-moderate severity or dyspnea (Global initiative for chronic Obstructive Lung disease [GOLD] grades 1 and 2; modified Medical Research Council [mMRC] grades 1 and 2) to those with severe-very severe severity or dyspnea (GOLD grades 3 and 4; mMRC grades 3 and 4). Methods: Combined individual patient data from the COPD Biomarkers Qualification Consortium database (trials of long-acting bronchodilators) were used comprising of patients from short-term (≀1-year duration; n=10802) and medium-term (2-4 years' duration; n=8963) studies. A repeated measures analysis of variance (ANOVA) was used to determine the effects of baseline severity (GOLD/mMRC) on SGRQ response to treatment. All treatment arms were combined. Results: In short-term studies, milder patients showed a greater response than those with more severe disease in terms of GOLD grade (partial Eta(2) = 0.03, p < 0.0001) and mMRC grade (partial Eta(2) = 0.05, p < 0.0001). Similar results were seen in the medium-term studies (partial Eta(2) = 0.02, p < 0.0001; mMRC: partial Eta(2) = 0.05, p < 0.0001,). Conclusions: Patients with less severe airflow limitation and less severe dyspnea showed larger improvements in SGRQ score than more severely obstructed or dyspneic patients. Although these severity influences are small (2%-5% of the variance in SGRQ score), they do suggest that pre-specified separate analyses are warranted to test for differences in response, based on baseline severity

    Responder Analyses for Treatment Effects in COPD Using the St George's Respiratory Questionnaire.

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    Background: Patient-reported outcomes data in clinical trials are usually reported as mean values, interpreted in comparison to a minimum clinically important difference (MCID) and ignoring the possibility of a sizable proportion of patients experiencing a worthwhile benefit when the majority did not. This analysis tested the reliability of calculated responder rates (from chronic obstructive pulmonary disease [COPD] patients) with the St George's Respiratory Questionnaire (SGRQ) using a range of responder cut-points above and below the MCID (4 units). Methods: Individual patient data (i.e., data from long-acting bronchodilator [LAB] and inhaled corticosteroids [ICS]/long-acting beta2-agonist [LABA] randomized clinical studies) in the COPD Biomarker Qualification Consortium database were used: short-term (≀1-year duration; 14,814 patients,) and medium-term (2-4 years; 12,043 patients). Responder rates versus placebo across SGRQ score change thresholds ranging from -1.5 to -8.0 were tested; differences were expressed as the odds ratio (OR) of a patient exceeding the threshold versus no change or deterioration. Results: The ORs measuring benefit of active treatment were similar across thresholds in short-term studies (LAB, ORs 1.40-1.42; LABA/ICS, 1.50-1.56) and medium-term LAB studies (ORs 1.34-1.43), whereas ORs in medium-term studies with LABA/ICS intervention showed a trend for higher response rates at higher values of threshold cut-points (1.64-1.79). In short-term studies, different thresholds had little effect on the OR between active drugs versus a trend for lower ORs with lower thresholds in medium-term studies. Conclusions: The OR for a treatment effect compared with placebo appears consistent across a range of responder cut-points. In medium-term trials, the treatment difference between active drugs suggests that use of a lower threshold would not increase the odds of observing a measured treatment difference

    The magical realism of body counts: How media credulity and flawed statistics sustain a controversial policy

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    The drone war in Pakistan poses humanitarian, legal, ethical and political challenges. The tactic is controversial and has been condemned by the United Nations&rsquo; special rapporteur on extrajudicial killings. Yet, polls have shown high support for the tactic in the United States (and to a lesser degree in the United Kingdom). Much of this has to do with the media reporting on the war, which consistently underestimates its human toll. Dubious statistics have sustained the image of a surgical war with little collateral damage. But as this article shows, there are reasons to doubt these numbers. The article argues that two interrelated factors have contributed to a flawed accounting of the war&rsquo;s human toll: (1) rituals of objectivity that privilege &lsquo;official sources&rsquo; and (2) fetishizing of statistics as hard facts without regard for the underlying data. The coverage has also been distorted by news values that downplay or ignore deaths in distant places unless they cross an inordinately high threshold

    Rectal Transmission of Transmitted/Founder HIV-1 Is Efficiently Prevented by Topical 1% Tenofovir in BLT Humanized Mice

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    Rectal microbicides are being developed to prevent new HIV infections in both men and women. We focused our in vivo preclinical efficacy study on rectally-applied tenofovir. BLT humanized mice (n = 43) were rectally inoculated with either the primary isolate HIV-1(JRCSF) or the MSM-derived transmitted/founder (T/F) virus HIV-1(THRO) within 30 minutes following treatment with topical 1% tenofovir or vehicle. Under our experimental conditions, in the absence of drug treatment we observed 50% and 60% rectal transmission by HIV-1(JRCSF) and HIV-1(THRO), respectively. Topical tenofovir reduced rectal transmission to 8% (1/12; log rank p = 0.03) for HIV-1(JRCSF) and 0% (0/6; log rank p = 0.02) for HIV-1(THRO). This is the first demonstration that any human T/F HIV-1 rectally infects humanized mice and that transmission of the T/F virus can be efficiently blocked by rectally applied 1% tenofovir. These results obtained in BLT mice, along with recent ex vivo, Phase 1 trial and non-human primate reports, provide a critically important step forward in the development of tenofovir-based rectal microbicides

    Optimized focusing ion optics for an ultracold deterministic single ion source targeting nm resolution

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    Using a segmented ion trap with mK laser-cooled ions we have realised a novel single ion source which can deterministically deliver a wide range of ion species, isotopes or ionic molecules [Schnitzler et al., Phys. Rev. Lett. 102, 070501 (2009)]. Experimental data is discussed in detail and compared with numerical simulations of ion trajectories. For the novel ion source we investigate numerically the influence of various extraction parameters on fluctuations in velocity and position of the beam. We present specialized ion optics and show from numerical simulations that nm resolution is achievable. The Paul trap, which is used as a single ion source, together with the presented ion optics, constitutes a promising candidate for a deterministic ion implantation method for applications in solid state quantum computing or classical nano-electronic devices.Comment: 17 pages, 13 figures (including 2 color figures), submitted to special issue of Journal of Modern Optics - Conference Proceedings of PQE-200

    The United States, PMSCs and the state monopoly on violence: Leading the way towards norm change

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2013 Sage.The proliferation of private military and security companies (PMSCs) in Iraq and Afghanistan has raised many questions regarding the use of armed force by private contractors. This article addresses the question of whether the increased acceptance of PMSCs indicates a transformation of the international norm regarding the state monopoly on the legitimate use of armed force. Drawing on theoretical approaches to the analysis of norm change, the article employs four measures to investigate possible changes in the strength and meaning of this norm: modifications in state behaviour, state responses to norm violation, the promulgation of varying interpretations of the norm in national and international laws and regulations, and changes in norm discourse. Based on an analysis of empirical evidence from the United States of America and its allies, the article concludes that these measures suggest that the USA is leading the way towards a transformation of the international norm of the state monopoly on violence, involving a revised meaning. Although this understanding has not yet been formally implemented in international law, it has allowed a growing number of countries to tolerate, accept or legalize the use of armed force by PMSCs in the international arena.The Alexander von Humboldt Foundation and the Peace Research Institute Frankfurt

    Could rebel child soldiers prolong civil wars?

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    While we know why rebels may recruit children for their cause, our understanding of the consequences of child soldiering by non-state armed groups remains limited. The following research contributes to addressing this by examining how rebels? child recruitment practice affects the duration of internal armed conflicts. We advance the argument that child soldiering increases the strength of rebel organizations vis-ïżœ-vis the government. This, in turn, lowers the capability asymmetry between these nonstate actors and the incumbent, allowing the former to sustain in dispute. Ultimately, the duration of armed conflicts is likely to be prolonged. We analyze this relationship with quantitative data on child soldier recruitment by rebel groups in the post-1989 period. The results confirm our main hypothesis: disputes are substantially longer when rebels recruit children. This work has important implications for the study of armed conflicts, conflict duration, and our understanding of child soldiering
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