735 research outputs found
Measured unsteady transonic aerodynamic characteristics of an elastic supercritical wing with an oscillating control surface
Transonic steady and unsteady aerodynamic data were measured on a large elastic wing in the NASA Langley Transonic Dynamics Tunnel. The wing had a supercritical airfoil shape and a leading-edge sweepback of 28.8 deg. The wing was heavily instrumented to measure both static and dynamic pressures and deflections. A hydraulically driven outboard control surface was oscillated to generate unsteady airloads on the wing. Representative results from the wind tunnel tests are presented and discussed, and the unexpected occurrence of an unusual dynamic wing instability, which was sensitive to angle of attack, is reported
Data and product needs for influenza immunization programs in low- and middle-income countries: Rationale and main conclusions of the WHO preferred product characteristics for next-generation influenza vaccines.
In 2017, WHO convened a working group of global experts to develop the Preferred Product Characteristics (PPC) for Next-Generation Influenza Vaccines. PPCs are intended to encourage innovation in vaccine development. They describe WHO preferences for parameters of vaccines, in particular their indications, target groups, implementation strategies, and clinical data needed for assessment of safety and efficacy. PPCs are shaped by the global unmet public health need in a priority disease area for which WHO encourages vaccine development. These preferences reflect WHO's mandate to promote the development of vaccines with high public health impact and suitability in Low- and Middle-Income Countries (LMIC). The target audience is all entities intending to develop or to achieve widespread adoption of a specific influenza vaccine product in these settings. The working group determined that existing influenza vaccines are not well suited for LMIC use. While many developed country manufactures and research funders prioritize influenza vaccine products for use in adults and the elderly, most LMICs do not have sufficiently strong health systems to deliver vaccines to these groups. Policy makers from LMICs are expected to place higher value on vaccines indicated for prevention of severe illness, however the clinical development of influenza vaccines focuses on demonstrating prevention of any influenza illness. Many influenza vaccine products do not meet WHO standards for programmatic suitability of vaccines, which introduces challenges when vaccines are used in low-resource settings. And finally, current vaccines do not integrate well with routine immunization programs in LMICs, given age of vaccine licensure, arbitrary expiration dates timed for temperate country markets, and the need for year-round immunization in countries with prolonged influenza seasonality. While all interested parties should refer to the full PPC document for details, in this article we highlight data needs for new influenza vaccines to better demonstrate the value proposition in LMICs
Прогностическое значение аспиринорезистентности при ишемической болезни сердца
Рассмотрены данные литературы о значении аспиринорезистентности при ИБС. Предложен разработанный авторами новый экспресс−метод определения чувствительности к аспирину. Показана роль аспиринорезистентности в развитии сердечно−сосудистых событий у больных.The literature data about the role of aspirin resistance in coronary artery disease are discussed. The original new express method of determining sensitivity to aspirin is suggested. The role of aspirin resistance in development of cardiovascular events in the patients is shown
Infant regulatory problems, parenting quality and childhood attention problems
Background and aims
To determine the combined impact of infant multiple/persistent regulatory problems (RPs), parenting quality and maternal mental health on childhood attention problems.
Study design
A prospective, population-based cohort study including 16 paediatric hospitals in Southern Bavaria (Germany).
Subjects
1459 infants were followed from birth to 8 years of age.
Outcome measures
RPs were assessed at 5 and 20 months using interviews by trained paediatricians; parenting quality was assessed between birth and 5 months using parent interviews and nurses' observations; maternal mental health was assessed at birth and 5 months using standardized parents' interviews; childhood data on attention problems were collected at 8 years, using parent reports and expert behaviour observation ratings.
Results
After correction for gestational age, sex, and socioeconomic status, early RPs (β = 0.079) and low parenting quality (β = 0.175) predicted later attention problems (R2 = 0.272). Their impact was additive, such that infants with both multiple/persistent RPs and poor parenting quality showed the highest attention problems 8 years later. However, the impact of RPs on attention was strongest for preterm children. Maternal mental health was a significant moderator of the relationship between parenting quality and attention problems. With adequate maternal mental health, good parenting quality was related to lower attention problems, yet with mental health problems present, the effect of good parenting on attention problems diminished.
Conclusions
Guidance and support for parents of infants with multiple/persistent crying, sleeping or feeding problems may be essential to prevent the development of childhood attention problems, especially when maternal mental health problems are present
An Analytical Assessment of NASA's N+1 Subsonic Fixed Wing Project Noise Goal
The Subsonic Fixed Wing Project of NASA's Fundamental Aeronautics Program has adopted a noise reduction goal for new, subsonic, single-aisle, civil aircraft expected to replace current 737 and A320 airplanes. These so-called 'N+1' aircraft - designated in NASA vernacular as such since they will follow the current, in-service, 'N' airplanes - are hoped to achieve certification noise goal levels of 32 cumulative EPNdB under current Stage 4 noise regulations. A notional, N+1, single-aisle, twinjet transport with ultrahigh bypass ratio turbofan engines is analyzed in this study using NASA software and methods. Several advanced noise-reduction technologies are analytically applied to the propulsion system and airframe. Certification noise levels are predicted and compared with the NASA goal
Genome-wide association study of lifetime cannabis use based on a large meta-analytic sample of 32330 subjects from the International Cannabis Consortium
Cannabis is the most widely produced and consumed illicit psychoactive substance worldwide. Occasional cannabis use can progress to frequent use, abuse and dependence with all known adverse physical, psychological and social consequences. Individual differences in cannabis initiation are heritable (40-48%). The International Cannabis Consortium was established with the aim to identify genetic risk variants of cannabis use. We conducted a meta-analysis of genome-wide association data of 13 cohorts (N=32 330) and four replication samples (N=5627). In addition, we performed a gene-based test of association, estimated single-nucleotide polymorphism (SNP)-based heritability and explored the genetic correlation between lifetime cannabis use and cigarette use using LD score regression. No individual SNPs reached genome-wide significance. Nonetheless, gene-based tests identified four genes significantly associated with lifetime cannabis use: NCAM1, CADM2, SCOC and KCNT2. Previous studies reported associations of NCAM1 with cigarette smoking and other substance use, and those of CADM2 with body mass index, processing speed and autism disorders, which are phenotypes previously reported to be associated with cannabis use. Furthermore, we showed that, combined across the genome, all common SNPs explained 13-20% (P<0.001) of the liability of lifetime cannabis use. Finally, there was a strong genetic correlation (rg=0.83; P=1.85 × 10(-8)) between lifetime cannabis use and lifetime cigarette smoking implying that the SNP effect sizes of the two traits are highly correlated. This is the largest meta-analysis of cannabis GWA studies to date, revealing important new insights into the genetic pathways of lifetime cannabis use. Future functional studies should explore the impact of the identified genes on the biological mechanisms of cannabis use.</p
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