Making Accident Statistics More Meaningful

With the improvement in driver licensing and highway policing systems throughout the country there has arisen the need for better reporting and analysis of accidents and accident trends. Many states have inaugurated standard IBM equipment and follow a more or less uniform system of recording and punching accident data on cards for machine analysis. In most respects the trends in this development have been very desirable but standardization is sometimes a virtue which may occasionally boomerang. After a system is once established it takes a great deal of effort to make a change and changes are frequently desirable. Standardization may thus become a hindrance to progress. In other areas this may be readily illustrated by the English and American system of mensuration as well as by our clumsy 12-month calendar. However, the purpose of this paper is not to propose a new system, but to add some needed extensions and improvements which make any system now in common usage much more effective. An illustration using actual data will be set forth to illustrate one type of problem in the field of accident prevention

Report of the direct infrared sensors panel

The direct infrared sensors panel considered a wide range of options for technologies relevant to the science goals of the Astrotech 21 mission set. Among the technologies assessed are: large format arrays; photon counting detectors; higher temperature 1 to 10 micro-m arrays; impurity band conduction (IBC) or blocked impurity band (BIB) detectors; readout electronics; and adapting the Space Infrared Telescope Facility and Hubble Space Telescope. Detailed development plans were presented for each of these technology areas

Mitochondrial dysfunction leads to nuclear genome instability: A link through iron-sulfur clusters

Mutations and deletions in the mitochondrial genome (mtDNA), as well as instability of the nuclear genome, are involved in multiple human diseases. Here we report that in Saccharomyces cerevisiae, loss of mtDNA leads to nuclear genome instability, through a process of cell cycle arrest and selection we define as a cellular crisis. This crisis is not mediated by the absence of respiration, but instead correlates with a reduction in the mitochondrial membrane potential. Analysis of cells undergoing this crisis identified a defect in iron-sulfur cluster (ISC) biogenesis, which requires normal mitochondrial function. We found that down-regulation of non-mitochondrial ISC protein biogenesis was sufficient to cause increased genomic instability in cells with intact mitochondrial function. These results suggest mitochondrial dysfunction stimulates nuclear genome instability by inhibiting the production of ISC-containing protein(s), which are required for maintenance of nuclear genome integrity

The Infrared Array Camera (IRAC) for the Spitzer Space Telescope

The Infrared Array Camera (IRAC) is one of three focal plane instruments in the Spitzer Space Telescope. IRAC is a four-channel camera that obtains simultaneous broad-band images at 3.6, 4.5, 5.8, and 8.0 microns. Two nearly adjacent 5.2x5.2 arcmin fields of view in the focal plane are viewed by the four channels in pairs (3.6 and 5.8 microns; 4.5 and 8 microns). All four detector arrays in the camera are 256x256 pixels in size, with the two shorter wavelength channels using InSb and the two longer wavelength channels using Si:As IBC detectors. IRAC is a powerful survey instrument because of its high sensitivity, large field of view, and four-color imaging. This paper summarizes the in-flight scientific, technical, and operational performance of IRAC.Comment: 7 pages, 3 figures. Accepted for publication in the ApJS. A higher resolution version is at http://cfa-www.harvard.edu/irac/publication

Cost-effectiveness analysis of sacubitril/valsartan vs enalapril in patients with heart failure and reduced ejection fraction

Importance  The angiotensin receptor neprilysin inhibitor sacubitril/valsartan was associated with a reduction in cardiovascular mortality, all-cause mortality, and hospitalizations compared with enalapril. Sacubitril/valsartan has been approved for use in heart failure (HF) with reduced ejection fraction in the United States and cost has been suggested as 1 factor that will influence the use of this agent. Objective  To estimate the cost-effectiveness of sacubitril/valsartan vs enalapril in the United States. Design, Setting, and Participants  Data from US adults (mean [SD] age, 63.8 [11.5] years) with HF with reduced ejection fraction and characteristics similar to those in the PARADIGM-HF trial were used as inputs for a 2-state Markov model simulated HF. Risks of all-cause mortality and hospitalization from HF or other reasons were estimated with a 30-year time horizon. Quality of life was based on trial EQ-5D scores. Hospital costs combined Medicare and private insurance reimbursement rates; medication costs included the wholesale acquisition cost for sacubitril/valsartan and enalapril. A discount rate of 3% was used. Sensitivity analyses were performed on key inputs including: hospital costs, mortality benefit, hazard ratio for hospitalization reduction, drug costs, and quality-of-life estimates. Main Outcomes and Measures  Hospitalizations, quality-adjusted life-years (QALYs), costs, and incremental costs per QALY gained. Results  The 2-state Markov model of US adult patients (mean age, 63.8 years) calculated that there would be 220 fewer hospital admissions per 1000 patients with HF treated with sacubitril/valsartan vs enalapril over 30 years. The incremental costs and QALYs gained with sacubitril/valsartan treatment were estimated at $35 512 and 0.78, respectively, compared with enalapril, equating to an incremental cost-effectiveness ratio (ICER) of$45 017 per QALY for the base-case. Sensitivity analyses demonstrated ICERs ranging from $35 357 to$75 301 per QALY. Conclusions and Relevance  For eligible patients with HF with reduced ejection fraction, the Markov model calculated that sacubitril/valsartan would increase life expectancy at an ICER consistent with other high-value accepted cardiovascular interventions. Sensitivity analyses demonstrated sacubitril/valsartan would remain cost-effective vs enalapril

Validation of Up-the-Ramp Sampling with Cosmic Ray Rejection on IR Detectors

We examine cosmic ray rejection methodology on data collected from InSb and Si:As detectors. The application of an Up-the-Ramp sampling technique with cosmic ray identification and mitigation is the focus of this study. This technique is valuable for space-based observatories which are exposed to high-radiation environments. We validate the Up-the-Ramp approach on radiation-test data sets with InSb and Si:As detectors which were generated for SIRTF. The Up-the-Ramp sampling method studied in this paper is over 99.9% effective at removing cosmic rays and preserves the structure and photometric quality of the image to well within the measurement error.Comment: 30 pages, 13 figures. Accepted for publication in the PASP, 25 October 200

Adolescents with metabolic syndrome have a history of low aerobic fitness and physical activity levels

Abstract: Purpose: Metabolic syndrome (MS) is a clustering of cardiovascular disease risk factors that identifies individuals with the highest risk for heart disease. Two factors that may influence the MS are physical activity and aerobic fitness. This study determined if adolescent with the MS had low levels of aerobic fitness and physical activity as children. Methods: This longitudinal, exploratory study had 389 participants: 51% girls, 84% Caucasian, 12% African American, 1% Hispanic, and 3% other races, from the State of North Carolina. Habitual physical activity (PA survey), aerobic fitness (VO2max), body mass index (BMI), blood pressure, and lipids obtained at 7–10 y of age were compared to their results obtained 7 y later at ages 14–17 y. Results: Eighteen adolescents (4.6%) developed 3 or more characteristics of the MS. Logistic regression, adjusting for BMI percentile, blood pressure, and cholesterol levels, found that adolescents with the MS were 6.08 (95%CI = 1.18–60.08) times more likely to have low aerobic fitness as children and 5.16 (95%CI = 1.06–49.66) times more likely to have low PA levels. Conclusion: Low levels of childhood physical activity and aerobic fitness are associated with the presence of the metabolic syndrome in adolescents. Thus, efforts need to begin early in childhood to increase exercise

Semiconductor detector performance for low-energy x-rays

Factors that limit the capabilities of semiconductor detectors at photon energies below 5 keV include energy resolution, detector efficiency, and detector-related continuum background. These properties can be controlled to a certain extent by optimal detector design and fabrication techniques. We describe measurements on the low-energy response of Si(Li) detectors obtained using a tunable, low-energy monochromatic source. Window thicknesses have been measured for a number of devices using different materials for the entry contact. The interpretation of these results in terms of existing detector window models is discussed. Results obtained using a new contact structure demonstrate that a dramatic reduction in window-related absorption in Si(Li) detectors can be achieved