20,234 research outputs found
Feasibility of an Incoherent-scatter Radar Aboard the Space Shuttle
The results of a preliminary study to investigate the feasibility of conducting an incoherent scatter radar experiment on board the space shuttle are presented. The results indicate that such an experiment is technically feasible. The more difficult questions to answer are whether the system can be made flexible enough to justify the problems and costs involved. The design parameters and the tradeoffs that are available in the consideration of these questions are evaluated. Some of the more serious limitations pertain to: (1) the presence of ground clutter and F region auroral clutter; (2) available average power; (3) weight and volume associated with required antenna size, transmitter, and energy storage devices; and (4) antenna breakdown associated with high power transmitter problems
Effect of seasonality and weather on fracture risk in individuals 65years and older
Summary: In this large population-based study, fracture rates for hips, distal forearms, proximal humeri, and ankles were higher in winter than in other seasons, although the winter peak was small for hip fractures (p < 0.05 at all sites). Younger age between 65 and 80, living in warmer states and male gender were associated with increased winter morbidity due to fractures. Introduction: The objective was to investigate seasonal variation in the incidence of four common fractures, and explore the association of weather with risk. Methods: Population-based analysis of individuals age 65 and older, including fractures of the hip, the distal forearm, the proximal humerus and the ankle. Weather information was obtained from the US National Oceanic and Atmospheric Administration website. Results: For all fractures, rates were highest in winter and lowest in summer (p < 0.05 at all sites). Winter peaks were more pronounced in warm climate states, in men, and in those younger than 80years old. In winter, total snowfall was associated with a reduced risk of hip fracture (−5% per 20inches) but an increased risk of non-hip fractures (6-12%; p < 0.05 at all sites). In summer, hip fracture risk tended to be lower during sunny weather (− 3% per 2weeks of sunny days; p = 0.13), while other fractures were increased (15%-20%; p < 0.05) in sunny weather. Conclusion: Fractures contribute considerably to winter morbidity in older individuals. Younger age between 65 and 80, living in warmer states and male gender are risk factors for increased winter morbidity due to fractures. Weather affects hip fracture risk differently than the other fractures studie
Detailed Spectral Modeling of a 3-D Pulsating Reverse Detonation Model: Too Much Nickel
We calculate detailed NLTE synthetic spectra of a Pulsating Reverse
Detonation (PRD) model, a novel explosion mechanism for Type Ia supernovae.
While the hydro models are calculated in 3-D, the spectra use an angle averaged
hydro model and thus some of the 3-D details are lost, but the overall average
should be a good representation of the average observed spectra. We study the
model at 3 epochs: maximum light, seven days prior to maximum light, and 5 days
after maximum light. At maximum the defining Si II feature is prominent, but
there is also a prominent C II feature, not usually observed in normal SNe Ia
near maximum. We compare to the early spectrum of SN 2006D which did show a
prominent C II feature, but the fit to the observations is not compelling.
Finally we compare to the post-maximum UV+optical spectrum of SN 1992A. With
the broad spectral coverage it is clear that the iron-peak elements on the
outside of the model push too much flux to the red and thus the particular PRD
realizations studied would be intrinsically far redder than observed SNe Ia. We
briefly discuss variations that could improve future PRD models.Comment: 15 pages, 4 figures, submitted to Ap
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The impact of mobile monitoring technologies on glycosylated hemoglobin in diabetes: a systematic review
Background: A new development in the field of telehealth is the use of mobile health technologies (mhealth) to help patients record and track medical information. Mhealth appears particularly advantageous for conditions that require intense and ongoing monitoring, such as diabetes, and where people are of working age and not disabled. This review aims to evaluate the evidence for the effectiveness of mhealth interventions in diabetes management on glycosylated hemoglobin.
Method: A comprehensive search strategy was developed and applied to eight electronic databases to identify studies that investigated the clinical effectiveness of mobile-based applications that allowed patients to record and send their blood glucose readings to a central server. The eligibility of 8543 papers was assessed against the selection criteria, and 24 papers were reviewed. All studies reviewed were assessed for quality using a standardized quality assessment tool.
Results: Results for patients with type 1 and type 2 diabetes were examined separately. Study variability and poor reporting made comparison difficult, and most studies had important methodological weaknesses. Evidence on the effectiveness of mhealth interventions for diabetes was inconsistent for both types of diabetes and remains weak
Taking a Constitutional: A Walking Tour of Boston\u27s Constitutional History
A tour supplementing The Freedom Trail and The Black Heritage Trail with sites and information of special relevance to the Bicentennial of the United States Constitution
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