574 research outputs found
Developing a Robust Balance for Wingsuit Aerodynamic Research
Research on wingsuit aerodynamics requires specialized wind tunnel equipment. There is the potential for the relatively large ram-air inflated fabric airfoils being examined to flap and oscillate uncontrolled in the wind tunnel airflow. This chaotic combination of motion and forces could damage the fragile precision balances currently used. Due to the relatively recent development of wingsuit flight as an active sport, there is very little background literature on wingsuit aerodynamics, wingsuit testing, and the equipment and sensors required. A new balance design, able to accurately measure and record basic lift and drag forces while also being able to withstand the potentially destructive unstable response of flexible fabric airfoils at airspeeds of up to 180 knots was required. An additional requirement was introduced by a severely constrained budget supporting this research.
There are several basic and inexpensive wind tunnel balance designs. Commercially available, highly accurate balances can easily cost 5000 that is capable of generating the data required for credible wingsuit aerodynamic research. The details of design process, components, assembly, and calibration are presented
Variability of crop calendar stage dates
There are no author-identified significant results in this report
Aerodynamic Forces on Flight Crew Helmets
Wind tunnel tests were conducted to deter- mine the aerodynamic forces generated on aircrew flight helmets. Three helmets were tested: two used by aircrews flying ejection seat aircraft in the U.S. military, the Navy HGU-33/P and the Air Force HGU-53/P; and one prototype helmet of significantly different shape and volume. Axial and normal forces were measured through a range of pitch and yaw angles. It was found that large forces exist tending to promote helmet loss during ejection, and that simple modifications to the current helmet configurations can reduce those forces by as much as 40%. It is demonstrated that the proper design of future helmet external geometry can contribute to the increased safety and survivability of aircrews in the ejection environment
Participant-Reported Symptoms and Their Effect on Long-Term Adherence in the International Breast Cancer Intervention Study I (IBIS I)
Purpose: To assess the role of participant-reported symptoms on long-term adherence to preventive therapy in the United Kingdom sample of the International Breast Cancer Intervention Study (IBIS-I). IBIS-I was a randomized controlled trial that investigated the effectiveness of tamoxifen in reducing the risk of breast cancer among women at increased risk of the disease. Participants and Methods: Women were randomly assigned to tamoxifen versus placebo (20 mg/day; n = 4,279). After 456 exclusions, 3,823 women were included in this analysis. Adherence (< 4.5 years or ≥ 4.5 years) was calculated using data from six monthly clinical visits. Analyses were adjusted for age, Tyrer-Cuzick risk, smoking, use of hormone replacement therapy, menopausal status, baseline menopausal symptoms, and treatment.
Results: Overall, 69.7% of women were adherent for at least 4.5 years (tamoxifen: 65.2% v placebo: 74.0%; P .05). In both treatment arms, we observed significant trends for lower adherence with increasing severity for all symptoms (P < .01) except headaches (P = .054).
Conclusion: In the IBIS-I trial, experiencing predefined symptoms in the first 6 months reduced long-term adherence. Effects were similar between treatment arms, suggesting that women were attributing age-related symptoms to preventive therapy. Interventions were required to support symptom management
Anastrozole-Induced Carpal Tunnel Syndrome: Results From the International Breast Cancer Intervention Study II Prevention Trial
Supported in part by Cancer Research UK
(C569/A5032) and the National Health and
Medical Research Council Australia
(GNT300755, GNT569213), and in part by
AstraZeneca, who also provided
anastrozole and matching placebo. This
study was sponsored by Queen Mary
University of London, London, United
Kingdom
Preliminary evaluation of spectral, normal and meteorological crop stage estimation approaches
Several of the projects in the AgRISTARS program require crop phenology information, including classification, acreage and yield estimation, and detection of episodal events. This study evaluates several crop calendar estimation techniques for their potential use in the program. The techniques, although generic in approach, were developed and tested on spring wheat data collected in 1978. There are three basic approaches to crop stage estimation: historical averages for an area (normal crop calendars), agrometeorological modeling of known crop-weather relationships agrometeorological (agromet) crop calendars, and interpretation of spectral signatures (spectral crop calendars). In all, 10 combinations of planting and biostage estimation models were evaluated. Dates of stage occurrence are estimated with biases between -4 and +4 days while root mean square errors range from 10 to 15 days. Results are inconclusive as to the superiority of any of the models and further evaluation of the models with the 1979 data set is recommended
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In Search of the Solar Wind Nitrogen Isotope Composition: Analysis of a Gold Plate from the Genesis Spacecraft Concentrator
We report N isotope analysis of a gold plate from the Genesis spacecraft concentrator. We did not find evidence for a light N component in the solar wind
Effect of Preventive Supplementation with Zinc and other Micronutrients on Non-Malarial Morbidity in Tanzanian Pre-School Children: A Randomized Trial.
The efficacy of preventive zinc supplementation against diarrhea and respiratory illness may depend on simultaneous supplementation with other micronutrients. We aimed to assess the effect of supplementation with zinc and multiple micronutrients on diarrhea and other causes of non-malarial morbidity. Rural Tanzanian children (n = 612) aged 6-60 months and with height-for-age z-score < -1.5 SD were randomized to daily supplementation with zinc (10 mg) alone, multi-nutrients without zinc, multi-nutrients with zinc, or placebo. Children were followed for an average of 45 weeks. During follow-up, we recorded morbidity episodes. We found no evidence that concurrent supplementation with multi-nutrients influenced the magnitude of the effect of zinc on rates of diarrhea, respiratory illness, fever without localizing signs, or other illness (guardian-reported illness with symptoms involving skin, ears, eyes and abscesses, but excluding trauma or burns). Zinc supplementation reduced the hazard rate of diarrhea by 24% (4%-40%). By contrast, multi-nutrients seemed to increase this rate (HR; 95% CI: 1.19; 0.94-1.50), particularly in children with asymptomatic Giardia infection at baseline (2.03; 1.24-3.32). Zinc also protected against episodes of fever without localizing signs (0.75; 0.57-0.96), but we found no evidence that it reduced the overall number of clinic visits. We found no evidence that the efficacy of zinc supplements in reducing diarrhea rates is enhanced by concurrent supplementation with other micronutrients. By reducing rates of fever without localizing signs, supplementation with zinc may reduce inappropriate drug use with anti-malarial medications and antibiotics. ClinicalTrials.gov NCT00623857
Relationships between CYP2D6 phenotype, breast cancer and hot flushes in women at high risk of breast cancer receiving prophylactic tamoxifen: results from the IBIS-I trial
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