98 research outputs found

    Multidisciplinary Design Optimization and Cruise Mach Number Study of Truss-Braced Wing Aircraft

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    The Subsonic Ultra Green Aircraft Research (SUGAR) Phase III was led by Dr. Rakesh K. Kapania and Dr. Joseph A. Schetz at the Multidisciplinary Analysis and Design Center for Advanced Vehicles, Department of Aerospace and Ocean Engineering, Virginia Tech, Blacksburg VA. The research was performed from December 2014 to December 2015. Three major areas were investigated: Multidisciplinary Design Optimization (MDO) studies of truss braced wing (TBW) and strut braced wing (SBW) vehicles at cruise Mach numbers of 0.7 and 0.8 for a flight mission similar to current market single aisle configurations. The performance and the characteristics of the optimized vehicles were compared to the SUGAR Phase II TBW vehicle. These results were obtained without applying any of the extended transonic aerodynamic and aeroelastic tools that will be discussed later. It was found that the cruise Mach number has a large effect on the best truss configuration. At Mach 0.7, an SBW has a better fuel consumption and better take-off gross weight (TOGW). However, at Mach 0.8, the TBW is superior because the jury strut aids in satisfying the flutter constraint; Two-dimensional, steady, transonic aerodynamic analysis of the Boeing Airfoil J (BACJ) airfoil was performed for a range of thickness ratios, Mach numbers and lift coefficients. Reynolds-averaged Navier-Stokes (RANS) equations were solved to obtain the lift-curve slope, wave drag coefficient, the location of the center of pressure and to predict the separation at the trailing edge, which may lead to buffeting. One of the goals was to develop a database of lift-curve slope and the location of center of pressure, which could be used in a transonic aeroelastic analysis. Another goal was to compare the wave drag coefficients to those predicted by Locks fourth-power law and also to compare the transonic effects obtained from RANS simulations to those predicted by the Korn equations. A third goal was to develop a buffet boundary, which can be integrated into the MDO framework to prevent the optimized designs from probable buffeting; A state-space transonic aeroelastic analysis tool was developed, which can incorporate the nonlinear transonic effects in the unsteady aerodynamics but is yet computationally cheap when used within the VT MDO framework. The aeroelastic analysis uses Leishman- Beddoes (LB) indicial functions, which generated a state-space representation of the aeroelastic system. The indicial functions allow the incorporation of data for steady lift-curve slope and location of the center of pressure. Thus, the steady transonic effects are included, and the unsteady aerodynamic responses are a linearization about the steady results. The aeroelastic approach discretizes the wing into numerous strips, which results in a large eigenvalue problem as each strip has eight augmented aerodynamic states as per the LB theory. Thus, to reduce the computation expense, a reduced order model (ROM) was developed. The approach was validated using a few examples

    Office-Based Educational Handout for Influenza Vaccination: A Randomized Controlled Trial

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    This is the author accepted manuscript. The final version is available from American Academy of Pediatrics via the DOI in this recordData sharing statement: De-identified individual participant data will not be made available.OBJECTIVES: To assess the impact of a parent educational intervention about influenza disease on child vaccine receipt. METHODS: A convenience sample of parents of children ≥6 months old with a visit at 2 New York City pediatric clinics between August 2016 and March 2017 were randomly assigned (1:1:1) to receive either usual care, an educational handout about influenza disease that was based on local data, or an educational handout about influenza disease that was based on national data. Parents received the handout in the waiting room before their visit. Primary outcomes were child influenza vaccine receipt on the day of the clinic visit and by the end of the season. A multivariable logistic regression was used to assess associations between intervention and vaccination, with adjustment for variables that were significantly different between arms. RESULTS: Parents who received an intervention (versus usual care) had greater odds of child influenza vaccine receipt by the end of the season (74.9% vs 65.4%; adjusted odds ratio 1.68; 95% confidence interval: 1.06-2.67) but not on the day of the clinic visit. Parents who received the national data handout (versus usual care) had greater odds of child influenza vaccine receipt on the day of the clinic visit (59.0% vs 52.6%; adjusted odds ratio 1.79; 95% confidence interval: 1.04-3.08) but not by the end of the season. CONCLUSIONS: Providing an educational intervention in the waiting room before a pediatric provider visit may help increase child influenza vaccine receipt.European CommissionNIH - Ruth L. Kirschstein National Research Service Awar

    Two patients with an anti-N-methyl-D-aspartate receptor antibody syndrome-like presentation and negative results of testing for autoantibodies. Pediatr Neurol

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    abstract We describe two boys whose distinct and remarkable clinical pictures suggested the possibility of anti-Nmethyl-D-aspartate receptor antibody encephalitis. Both patients responded to immunotherapy, but neither manifested that antibody. Patient 1 exhibited florid encephalopathy with psychotic manifestations including inappropriate affect, intermittent delirium, visual hallucinations, severe anorexia, agitation, paranoid ideation, and abnormal electroencephalogram results. He responded to intravenous immunoglobulin, with steady improvement over 3 months to almost complete remission for 1 year, followed by a relapse that again responded, more quickly, to intravenous immunoglobulin. A second relapse occurred 1 month later, and again responded to intravenous immunoglobulin. Patient 2 exhibited progressive, severely debilitating limb dystonia that worsened over 1.5 years, with milder psychiatric symptoms including mood instability, aggressiveness, impulsivity, and depression. When he developed thymic hyperplasia 1.5 years into his illness, he underwent a thymectomy, and improved significantly on a regimen of plasmapheresis and intravenous immunoglobulin. Patients presenting with symptoms suggestive of autoimmune encephalitis, but without antibodies, may still respond to immunotherapy

    The accuracy of MRI in the detection of Lumbar Disc Containment

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    <p>Abstract</p> <p>Background</p> <p>MRI has proven to be an extremely valuable tool in the assessment of normal and pathological spinal anatomy. Accordingly, it is commonly used to assess containment of discal material by the outer fibers of the anulus fibrosus and posterior longitudinal ligaments. Determination of such containment is important to determine candidacy for intradiscal techniques and has prognostic significance. The accuracy of MRI in detecting containment has been insufficiently documented.</p> <p>Methods</p> <p>The MRI's of fifty consecutive patients undergoing open lumbar microdiscectomy were prospectively evaluated for disc containment by a neuroradiologist and senior spinal surgeon using criteria available in the literature and the classification of Macnab/McCulloch. An independent surgeon then performed the surgery and documented the actual containment status using the same methods. Statistical evaluation of accuracy was undertaken.</p> <p>Results</p> <p>MRI was found to be 72% sensitive, 68% specific, and 70% accurate in detecting containment status of lumbar herniated discs.</p> <p>Conclusion</p> <p>MRI may be inaccurate in assessing containment status of lumbar disc herniations in 30% of cases. Given the importance of containment for patient selection for indirect discectomy techniques and intradiscal therapies, coupled with prognostic significance; other methods to assess containment should be employed to assess containment when such alternative interventions are being considered.</p

    The Relative Merits of Posterior Surgical Treatments for Multi-Level Degenerative Cervical Myelopathy Remain Uncertain: Findings from a Systematic Review.

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    OBJECTIVES: To assess the reporting of study design and characteristics in multi-level degenerative cervical myelopathy (DCM) treated by posterior surgical approaches, and perform a comparison of clinical and radiographic outcomes between different approaches. METHODS: A literature search was performed in Embase and MEDLINE between 1995-2019 using a sensitive search string combination. Studies were selected by predefined selection criteria: Full text articles in English, with >10 patients (prospective) or >50 patients (retrospective), reporting outcomes of multi-level DCM treated by posterior surgical approach. RESULTS: A total of 75 studies involving 19,510 patients, conducted worldwide, were identified. Laminoplasty was described in 56 studies (75%), followed by laminectomy with (36%) and without fusion (16%). The majority of studies were conducted in Asia (84%), in the period of 2016-2019 (51%), of which laminoplasty was studied predominantly. Twelve (16%) prospective studies and 63 (84%) retrospective studies were identified. The vast majority of studies were conducted in a single centre (95%) with clear inclusion/exclusion criteria and explicit cause of DCM. Eleven studies (15%) included patients with ossification of the posterior longitudinal ligament exclusively with cohorts of 57 to 252. The clinical and radiographic outcomes were reported with heterogeneity when comparing laminoplasty, laminectomy with and without fusion. CONCLUSIONS: Heterogeneity in the reporting of study and sample characteristics exists, as well as in clinical and radiographic outcomes, with a paucity of studies with a higher level of evidence. Future studies are needed to elucidate the clinical effectiveness of posterior surgical treatments

    A map of transcriptional heterogeneity and regulatory variation in human microglia.

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    Microglia, the tissue-resident macrophages of the central nervous system (CNS), play critical roles in immune defense, development and homeostasis. However, isolating microglia from humans in large numbers is challenging. Here, we profiled gene expression variation in primary human microglia isolated from 141 patients undergoing neurosurgery. Using single-cell and bulk RNA sequencing, we identify how age, sex and clinical pathology influence microglia gene expression and which genetic variants have microglia-specific functions using expression quantitative trait loci (eQTL) mapping. We follow up one of our findings using a human induced pluripotent stem cell-based macrophage model to fine-map a candidate causal variant for Alzheimer's disease at the BIN1 locus. Our study provides a population-scale transcriptional map of a critically important cell for human CNS development and disease

    Socio-Technical Innovation Bundles for Agri-Food Systems Transformation

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    Technological and institutional innovations in agri-food systems (AFSs) over the past century have brought dramatic advances in human well-being worldwide. Yet these gains increasingly appear unsustainable due to massive, adverse spillover effects on climate, natural environment, public health and nutrition, and social justice. How can humanity innovate further to bring about AFS transformations that can sustain and expand past progress, while making them healthier for all people and for the planet that must sustain current and future generations? This report was commissioned by the Cornell Atkinson Center for Sustainability in response to an invitation from the journal Nature Sustainability, which—in collaboration with its new sister journal, Nature Food—wanted to devote its 2020 expert panel to this topic. The panel brought together experts who come from many different continents and who span a wide range of disciplines and organizations—from industry and universities to social movements, governments, philanthropies, institutional and venture capital investors, and multilateral agencies. The panel synthesized the best current science to describe the present state of the world’s AFSs and key external drivers of AFS changes over the next 25–50 years, as well as tease out key lessons from the COVID-19 pandemic experience this year. As is increasingly widely recognized, the costs that farmers and downstream value chain actors incur and the prices consumers pay understate foods’ true costs to society once one accounts for adverse environmental, health, and social spillover effects. Inevitable demographic, economic, and climate change in the coming decades will catastrophically aggravate these problems under business-as-usual scenarios. Innovations will be needed to facilitate concerted, coordinated efforts to transition to more healthy, equitable, resilient, and sustainable AFSs

    Brucellosis as an Emerging Threat in Developing Economies:Lessons from Nigeria

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    Nigeria is the most populous country in Africa, has a large proportion of the world's poor livestock keepers, and is a hotspot for neglected zoonoses. A review of the 127 accessible publications on brucellosis in Nigeria reveals only scant and fragmented evidence on its spatial and temporal distribution in different epidemiological contexts. The few bacteriological studies conducted demonstrate the existence of Brucella abortus in cattle and sheep, but evidence for B. melitensis in small ruminants is dated and unclear. The bulk of the evidence consists of seroprevalence studies, but test standardization and validation are not always adequately described, and misinterpretations exist with regard to sensitivity and/or specificity and ability to identify the infecting Brucella species. Despite this, early studies suggest that although brucellosis was endemic in extensive nomadic systems, seroprevalence was low, and brucellosis was not perceived as a real burden; recent studies, however, may reflect a changing trend. Concerning human brucellosis, no studies have identified the Brucella species and most reports provide only serological evidence of contact with Brucella in the classical risk groups; some suggest brucellosis misdiagnoses as malaria or other febrile conditions. The investigation of a severe outbreak that occurred in the late 1970s describes the emergence of animal and human disease caused by the settling of previously nomadic populations during the Sahelian drought. There appears to be an increasing risk of re-emergence of brucellosis in sub-Saharan Africa, as a result of the co-existence of pastoralist movements and the increase of intensive management resulting from growing urbanization and food demand. Highly contagious zoonoses like brucellosis pose a threat with far-reaching social and political consequences
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