590 research outputs found

    Evaluation of analysis techniques for low frequency interior noise and vibration of commercial aircraft

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    The application of selected analysis techniques to low frequency cabin noise associated with advanced propeller engine installations is evaluated. Three design analysis techniques were chosen for evaluation including finite element analysis, statistical energy analysis (SEA), and a power flow method using element of SEA (computer program Propeller Aircraft Interior Noise). An overview of the three procedures is provided. Data from tests of a 727 airplane (modified to accept a propeller engine) were used to compare with predictions. Comparisons of predicted and measured levels at the end of the first year's effort showed reasonable agreement leading to the conclusion that each technique had value for propeller engine noise predictions on large commercial transports. However, variations in agreement were large enough to remain cautious and to lead to recommendations for further work with each technique. Assessment of the second year's results leads to the conclusion that the selected techniques can accurately predict trends and can be useful to a designer, but that absolute level predictions remain unreliable due to complexity of the aircraft structure and low modal densities

    Application of analysis techniques for low frequency interior noise and vibration of commercial aircraft

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    Finite element analysis (FEA), statistical energy analysis (SEA), and a power flow method (computer program PAIN) were used to assess low frequency interior noise associated with advanced propeller installations. FEA and SEA models were used to predict cabin noise and vibration and evaluate suppression concepts for structure-borne noise associated with the shaft rotational frequency and harmonics (less than 100 Hz). SEA and PAIN models were used to predict cabin noise and vibration and evaluate suppression concepts for airborne noise associated with engine radiated propeller tones. Both aft-mounted and wing-mounted propeller configurations were evaluated. Ground vibration test data from a 727 airplane modified to accept a propeller engine were used to compare with predictions for the aft-mounted propeller. Similar data from the 767 airplane was used for the wing-mounted comparisons

    Dendritic cell quiescence during systemic inflammation driven by LPS stimulation of radioresistant cells in vivo

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    Dendritic cell (DC) activation is a prerequisite for T cell priming. During infection, activation can ensue from signaling via pattern-recognition receptors after contact with pathogens or infected cells. Alternatively, it has been proposed that DCs can be activated indirectly by signals produced by infected tissues. To address the contribution of tissue-derived signals, we measured DC activation in a model in which radioresistant cells can or cannot respond to lipopolysaccharide (LPS). We report that recognition of LPS by the radioresistant compartment is sufficient to induce local and systemic inflammation characterized by high circulating levels of tumor necrosis factor (TNF) α, interleukin (IL) 1β, IL-6, and CC chemokine ligand 2. However, this is not sufficient to activate DCs, whether measured by migration, gene expression, phenotypic, or functional criteria, or to render DC refractory to subsequent stimulation with CpG-containing DNA. Similarly, acute or chronic exposure to proinflammatory cytokines such as TNF-α ± interferon α/β has marginal effects on DC phenotype in vivo when compared with LPS. In addition, DC activation and migration induced by LPS is unimpaired when radioresistant cells cannot respond to the stimulus. Thus, inflammatory mediators originating from nonhematopoietic tissues and from radioresistant hematopoietic cells are neither sufficient nor required for DC activation in vivo

    fMRI evidence of ‘mirror’ responses to geometric shapes

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    Mirror neurons may be a genetic adaptation for social interaction [1]. Alternatively, the associative hypothesis [2], [3] proposes that the development of mirror neurons is driven by sensorimotor learning, and that, given suitable experience, mirror neurons will respond to any stimulus. This hypothesis was tested using fMRI adaptation to index populations of cells with mirror properties. After sensorimotor training, where geometric shapes were paired with hand actions, BOLD response was measured while human participants experienced runs of events in which shape observation alternated with action execution or observation. Adaptation from shapes to action execution, and critically, observation, occurred in ventral premotor cortex (PMv) and inferior parietal lobule (IPL). Adaptation from shapes to execution indicates that neuronal populations responding to the shapes had motor properties, while adaptation to observation demonstrates that these populations had mirror properties. These results indicate that sensorimotor training induced populations of cells with mirror properties in PMv and IPL to respond to the observation of arbitrary shapes. They suggest that the mirror system has not been shaped by evolution to respond in a mirror fashion to biological actions; instead, its development is mediated by stimulus-general processes of learning within a system adapted for visuomotor control

    Swiss QUality of life and healthcare impact Assessment in a Real-world Erenumab treated migraine population (SQUARE study): interim results

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    BACKGROUND The fully human monoclonal antibody erenumab, which targets the calcitonin gene-related peptide (CGRP) receptor, was licensed in Switzerland in July 2018 for the prophylactic treatment of migraine. To complement findings from the pivotal program, this observational study was designed to collect and evaluate clinical data on the impact of erenumab on several endpoints, such as quality of life, migraine-related impairment and treatment satisfaction in a real-world setting. METHODS An interim analysis was conducted after all patients completed 6 months of erenumab treatment. Patients kept a headache diary and completed questionnaires at follow up visits. The overall study duration comprises 24 months. RESULTS In total, 172 adults with chronic or episodic migraine from 19 different sites across Switzerland were enrolled to receive erenumab every 4 weeks. At baseline, patients had 16.6 ± 7.2 monthly migraine days (MMD) and 11.6 ± 7.0 acute migraine-specific medication days per month. After 6 months, erenumab treatment reduced Headache Impact Test (HIT-6™) scores by 7.7 ± 8.4 (p < 0.001), the modified Migraine Disability Assessment (mMIDAS) by 14.1 ± 17.8 (p < 0.001), MMD by 7.6 ± 7.0 (p < 0.001) and acute migraine-specific medication days per month by 6.6 ± 5.4 (p < 0.001). Erenumab also reduced the impact of migraine on social and family life, as evidenced by a reduction of Impact of Migraine on Partners and Adolescent Children (IMPAC) scores by 6.1 ± 6.7 (p < 0.001). Patients reported a mean effectiveness of 67.1, convenience of 82.4 and global satisfaction of 72.4 in the Treatment Satisfaction Questionnaire for Medication (TSQM-9). In total, 99 adverse events (AE) and 12 serious adverse events (SAE) were observed in 62 and 11 patients, respectively. All SAE were regarded as not related to the study medication. CONCLUSIONS Overall quality of life improved and treatment satisfaction was rated high with erenumab treatment in real-world clinical practice. In addition, the reported impact of migraine on spouses and children of patients was reduced. TRIAL REGISTRATION BASEC ID 2018-02,375 in the Register of All Projects in Switzerland (RAPS)

    Swiss QUality of life and healthcare impact Assessment in a Real-world Erenumab treated migraine population (SQUARE study): interim results.

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    BACKGROUND The fully human monoclonal antibody erenumab, which targets the calcitonin gene-related peptide (CGRP) receptor, was licensed in Switzerland in July 2018 for the prophylactic treatment of migraine. To complement findings from the pivotal program, this observational study was designed to collect and evaluate clinical data on the impact of erenumab on several endpoints, such as quality of life, migraine-related impairment and treatment satisfaction in a real-world setting. METHODS An interim analysis was conducted after all patients completed 6 months of erenumab treatment. Patients kept a headache diary and completed questionnaires at follow up visits. The overall study duration comprises 24 months. RESULTS In total, 172 adults with chronic or episodic migraine from 19 different sites across Switzerland were enrolled to receive erenumab every 4 weeks. At baseline, patients had 16.6 ± 7.2 monthly migraine days (MMD) and 11.6 ± 7.0 acute migraine-specific medication days per month. After 6 months, erenumab treatment reduced Headache Impact Test (HIT-6™) scores by 7.7 ± 8.4 (p < 0.001), the modified Migraine Disability Assessment (mMIDAS) by 14.1 ± 17.8 (p < 0.001), MMD by 7.6 ± 7.0 (p < 0.001) and acute migraine-specific medication days per month by 6.6 ± 5.4 (p < 0.001). Erenumab also reduced the impact of migraine on social and family life, as evidenced by a reduction of Impact of Migraine on Partners and Adolescent Children (IMPAC) scores by 6.1 ± 6.7 (p < 0.001). Patients reported a mean effectiveness of 67.1, convenience of 82.4 and global satisfaction of 72.4 in the Treatment Satisfaction Questionnaire for Medication (TSQM-9). In total, 99 adverse events (AE) and 12 serious adverse events (SAE) were observed in 62 and 11 patients, respectively. All SAE were regarded as not related to the study medication. CONCLUSIONS Overall quality of life improved and treatment satisfaction was rated high with erenumab treatment in real-world clinical practice. In addition, the reported impact of migraine on spouses and children of patients was reduced. TRIAL REGISTRATION BASEC ID 2018-02,375 in the Register of All Projects in Switzerland (RAPS)

    Efficient in vitro RNA interference and immunofluorescence-based phenotype analysis in a human parasitic nematode, Brugia malayi

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    <p>Abstract</p> <p>Background</p> <p>RNA interference (RNAi) is an efficient reverse genetics technique for investigating gene function in eukaryotes. The method has been widely used in model organisms, such as the free-living nematode <it>Caenorhabditis elegans</it>, where it has been deployed in genome-wide high throughput screens to identify genes involved in many cellular and developmental processes. However, RNAi techniques have not translated efficiently to animal parasitic nematodes that afflict humans, livestock and companion animals across the globe, creating a dependency on data tentatively inferred from <it>C. elegans</it>.</p> <p>Results</p> <p>We report improved and effective <it>in vitro </it>RNAi procedures we have developed using heterogeneous short interfering RNA (hsiRNA) mixtures that when coupled with optimized immunostaining techniques yield detailed analysis of cytological defects in the human parasitic nematode, <it>Brugia malayi</it>. The cellular disorganization observed in <it>B. malayi </it>embryos following RNAi targeting the genes encoding γ-tubulin, and the polarity determinant protein, PAR-1, faithfully phenocopy the known defects associated with gene silencing of their <it>C. elegans </it>orthologs. Targeting the <it>B. malayi </it>cell junction protein, AJM-1 gave a similar but more severe phenotype than that observed in <it>C. elegans</it>. Cellular phenotypes induced by our <it>in vitro </it>RNAi procedure can be observed by immunofluorescence in as little as one week.</p> <p>Conclusions</p> <p>We observed cytological defects following RNAi targeting all seven <it>B. malayi </it>transcripts tested and the phenotypes mirror those documented for orthologous genes in the model organism <it>C. elegans</it>. This highlights the reliability, effectiveness and specificity of our RNAi and immunostaining procedures. We anticipate that these techniques will be widely applicable to other important animal parasitic nematodes, which have hitherto been mostly refractory to such genetic analysis.</p

    The Southern African Regional Science Initiative (SAFARI 2000): Overview of the Dry Season Field Campaign

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    The Southern African Regional Science Initiative (SAFARI 2000) is an international science project investigating the earth-atmosphere-human system in southern Africa. The programme was conducted over a two-year period from March 1999 to March 2001. The dry season field campaign (August-September 2000) was the most intensive activity and involved over 200 scientists from eighteen countries. The main objectives were to characterize and quantify biogenic, pyrogenic and anthropogenic aerosol and trace gas emissions and their transport and transformations in the atmosphere, and to validate NASA\u27s Earth Observing System\u27s satellite Terra within a scientific context. Five aircraft - two South African Weather Service Aerocommanders, the University of Washington\u27s CV-580, the U.K. Meteorological Office\u27s C-130, and NASA\u27s ER-2-with different altitude capabilities, participated in the campaign. Additional airborne sampling of southern African air masses, that had moved downwind of the subcontinent, was conducted by the CSIRO over Australia. Multiple observations were made in various geographical sectors under different synoptic conditions. Airborne missions were designed to optimize the value of synchronous over-flights of the Terra satellite platform, above regional ground validation and science targets. Numerous smaller-scale ground validation activities took place throughout the subcontinent during the campaign period
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