1,498 research outputs found

    Virtual Prototype of Shuttle Bay Door

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    This study analyzed the motion of the Space Shuttle free floating in space after one of its bay doors is opened and closed. Kane\u27s method and Autolev motion simulation software were used to carry out simulation and analysis. The Space Shuttle has two large bay doors that open simultaneously, but for our study we analyzed a hypothetical situation, in which only one door functioned properly, in order to achieve amplified results. To model this system we used a rigid body to resemble the Shuttle and an attached rotating flap to resemble the door. Since the Shuttle is free floating in space with no external forces, the rigid body has six degrees of freedom. The rotating flap has one degree of freedom, therefore giving the system a total of seven degrees of freedom. Through the use of Autolev dynamic analysis software, we were able to program the system to output codes compatible with Matlab in order to graph the motion of the multibody system

    An exemplary life? A personal construct analysis of the autobiography of Rudolf Hoess, Commandant of Auschwitz

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    This is an Accepted Manuscript of an article published by Taylor & Francis Group in Journal of Constructivist Psychology on 27 August 2014, available online at: https://www.tandfonline.com/doi/abs/10.1080/10720537.2013.849214This article analyses the autobiography of Rudolf Hoess, commandant of Auschwitz. Textual grid, ABC and self-characterisation analyses of the autobiography are used to construe Hoess’s writing. The textual grid analysis suggests that Hoess saw his adult self as being different from others but his young self as similar to Jews. Conflicts in self-construing are identified. The ABC analysis indicates that, from his perspective, it made sense for Hoess to choose not to leave the concentration camp service. The self-characterisation analysis focuses on whether Hoess experienced Kellyan guilt and it suggests that he did, but in unexpected contexts.Peer reviewedFinal Accepted Versio

    The State of Vaccine Confidence 2016: Global Insights Through a 67-Country Survey.

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    BACKGROUND: Public trust in immunization is an increasingly important global health issue. Losses in confidence in vaccines and immunization programmes can lead to vaccine reluctance and refusal, risking disease outbreaks and challenging immunization goals in high- and low-income settings. National and international immunization stakeholders have called for better monitoring of vaccine confidence to identify emerging concerns before they evolve into vaccine confidence crises. METHODS: We perform a large-scale, data-driven study on worldwide attitudes to immunizations. This survey - which we believe represents the largest survey on confidence in immunization to date - examines perceptions of vaccine importance, safety, effectiveness, and religious compatibility among 65,819 individuals across 67 countries. Hierarchical models are employed to probe relationships between individual- and country-level socio-economic factors and vaccine attitudes obtained through the four-question, Likert-scale survey. FINDINGS: Overall sentiment towards vaccinations is positive across all 67 countries, however there is wide variability between countries and across world regions. Vaccine-safety related sentiment is particularly negative in the European region, which has seven of the ten least confident countries, with 41% of respondents in France and 36% of respondents in Bosnia & Herzegovina reporting that they disagree that vaccines are safe (compared to a global average of 13%). The oldest age group (65+) and Roman Catholics (amongst all faiths surveyed) are associated with positive views on vaccine sentiment, while the Western Pacific region reported the highest level of religious incompatibility with vaccines. Countries with high levels of schooling and good access to health services are associated with lower rates of positive sentiment, pointing to an emerging inverse relationship between vaccine sentiments and socio-economic status. CONCLUSIONS: Regular monitoring of vaccine attitudes - coupled with monitoring of local immunization rates - at the national and sub-national levels can identify populations with declining confidence and acceptance. These populations should be prioritized to further investigate the drivers of negative sentiment and to inform appropriate interventions to prevent adverse public health outcomes

    Accumulation of specific sterol precursors targets a MAP kinase cascade mediating cell-cell recognition and fusion

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    Sterols are vital components of eukaryotic cell membranes. Defects in sterol biosynthesis, which result in the accumulation of precursor molecules, are commonly associated with cellular disorders and disease. However, the effects of these sterol precursors on the metabolism, signaling, and behavior of cells are only poorly understood. In this study, we show that the accumulation of only ergosterol precursors with a conjugated double bond in their aliphatic side chain specifically disrupts cell–cell communication and fusion in the fungus Neurospora crassa. Genetically identical germinating spores of this fungus undergo cell–cell fusion, thereby forming a highly interconnected supracellular network during colony initiation. Before fusion, the cells use an unusual signaling mechanism that involves the coordinated and alternating switching between signal sending and receiving states of the two fusion partners. Accumulation of only ergosterol precursors with a conjugated double bond in their aliphatic side chain disrupts this coordinated cell–cell communication and suppresses cell fusion. These specific sterol precursors target a single ERK-like mitogen-activated protein (MAP) kinase (MAK-1)-signaling cascade, whereas a second MAP kinase pathway (MAK-2), which is also involved in cell fusion, is unaffected. These observations indicate that a minor specific change in sterol structure can exert a strong detrimental effect on a key signaling pathway of the cell, resulting in the absence of cell fusion

    A self-referenced in-situ arrival time monitor for X-ray free-electron lasers

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    We present a novel, highly versatile, and self-referenced arrival time monitor for measuring the femtosecond time delay between a hard X-ray pulse from a free-electron laser and an optical laser pulse, measured directly on the same sample used for pump-probe experiments. Two chirped and picosecond long optical supercontinuum pulses traverse the sample with a mutually fixed time delay of 970 fs, while a femtosecond X-ray pulse arrives at an instant in between both pulses. Behind the sample the supercontinuum pulses are temporally overlapped to yield near-perfect destructive interference in the absence of the X-ray pulse. Stimulation of the sample with an X-ray pulse delivers non-zero contributions at certain optical wavelengths, which serve as a measure of the relative arrival time of the X-ray pulse with an accuracy of better than 25 fs. We find an excellent agreement of our monitor with the existing timing diagnostics at the SACLA XFEL with a Pearson correlation value of 0.98. We demonstrate a high sensitivity to measure X-ray pulses with pulse energies as low as 30 μ\muJ. Using a free-flowing liquid jet as interaction sample ensures the full replacement of the sample volume for each X-ray/optical event, thus enabling its utility even at MHz repetition rate XFEL sources

    Introducing EMMIE: An evidence rating scale to encourage mixed-method crime prevention synthesis reviews

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    Objectives This short report describes the need for, and the development of, a coding system to distil the quality and coverage of systematic reviews of the evidence relating to crime prevention interventions. The starting point for the coding system concerns the evidence needs of policymakers and practitioners. Methods The coding scheme (EMMIE) proposed builds on previous scales that have been developed to assess the probity, coverage and utility of evidence both in health and criminal justice. It also draws on the principles of realist synthesis and review. Results The proposed EMMIE scale identifies five dimensions to which systematic reviews intended to inform crime prevention should speak. These are the Effect of intervention, the identification of the causal Mechanism(s) through which interventions are intended to work, the factors that Moderate their impact, the articulation of practical Implementation issues, and the Economic costs of intervention

    Reducing bias in open-label trials where blinded outcome assessment is not feasible: strategies from two randomised trials

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    Background Blinded outcome assessment is recommended in open-label trials to reduce bias, however it is not always feasible. It is therefore important to find other means of reducing bias in these scenarios. Methods We describe two randomised trials where blinded outcome assessment was not possible, and discuss the strategies used to reduce the possibility of bias. Results TRIGGER was an open-label cluster randomised trial whose primary outcome was further bleeding. Because of the cluster randomisation, all researchers in a hospital were aware of treatment allocation and so could not perform a blinded assessment. A blinded adjudication committee was also not feasible as it was impossible to compile relevant information to send to the committee in a blinded manner. Therefore, the definition of further bleeding was modified to exclude subjective aspects (such as whether symptoms like vomiting blood were severe enough to indicate the outcome had been met), leaving only objective aspects (the presence versus absence of active bleeding in the upper gastrointestinal tract confirmed by an internal examination). TAPPS was an open-label trial whose primary outcome was whether the patient was referred for a pleural drainage procedure. Allowing a blinded assessor to decide whether to refer the patient for a procedure was not feasible as many clinicians may be reluctant to enrol patients into the trial if they cannot be involved in their care during follow-up. Assessment by an adjudication committee was not possible, as the outcome either occurred or did not. Therefore, the decision pathway for procedure referral was modified. If a chest x-ray indicated that more than a third of the pleural space filled with fluid, the patient could be referred for a procedure; otherwise, the unblinded clinician was required to reach a consensus on referral with a blinded assessor. This process allowed the unblinded clinician to be involved in the patient’s care, while reducing the potential for bias. Conclusions When blinded outcome assessment is not possible, it may be useful to modify the outcome definition or method of assessment to reduce the risk of bias

    Implementation of customer relationship management and inventory control software: a multiple case study of small retailers

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    Gemstone Team Small Business SolutionsThis study examines the impact of customer relationship management and inventory control software on small retail stores. Our team began by conducting a literature review, retailer-needs surveys, and product design interviews. We determined that small retailers have a need for a simple reminder system to assist in tracking customers and inventory. We then designed software to address these needs and tested it in two case study stores. We also conducted a systematic review of other case studies of software implementation in small businesses and identified ten factors that influence small business adoption of software. The five factors that influenced the failure to implement the system in these stores were consistent with the framework identified in the systematic review. The identified factors are relative advantages of the system compared to competitor products, compatibility with existing applications, the user's computer self-efficacy, ease-of-use of the system, and store owners' attitude toward information technology

    Genetic Determinants of Circulating Sphingolipid Concentrations in European Populations

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    Sphingolipids have essential roles as structural components of cell membranes and in cell signalling, and disruption of their metabolism causes several diseases, with diverse neurological, psychiatric, and metabolic consequences. Increasingly, variants within a few of the genes that encode enzymes involved in sphingolipid metabolism are being associated with complex disease phenotypes. Direct experimental evidence supports a role of specific sphingolipid species in several common complex chronic disease processes including atherosclerotic plaque formation, myocardial infarction (MI), cardiomyopathy, pancreatic beta-cell failure, insulin resistance, and type 2 diabetes mellitus. Therefore, sphingolipids represent novel and important intermediate phenotypes for genetic analysis, yet little is known about the major genetic variants that influence their circulating levels in the general population. We performed a genome-wide association study (GWAS) between 318,237 single-nucleotide polymorphisms (SNPs) and levels of circulating sphingomyelin (SM), dihydrosphingomyelin (Dih-SM), ceramide (Cer), and glucosylceramide (GluCer) single lipid species (33 traits); and 43 matched metabolite ratios measured in 4,400 subjects from five diverse European populations. Associated variants (32) in five genomic regions were identified with genome-wide significant corrected p-values ranging down to 9.08 x 10(-66). The strongest associations were observed in or near 7 genes functionally involved in ceramide biosynthesis and trafficking: SPTLC3, LASS4, SGPP1, ATP10D, and FADS1-3. Variants in 3 loci (ATP10D, FADS3, and SPTLC3) associate with MI in a series of three German MI studies. An additional 70 variants across 23 candidate genes involved in sphingolipid-metabolizing pathways also demonstrate association (p = 10(-4) or less). Circulating concentrations of several key components in sphingolipid metabolism are thus under strong genetic control, and variants in these loci can be tested for a role in the development of common cardiovascular, metabolic, neurological, and psychiatric diseases
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