8,338 research outputs found
Goals and Plans in Protective Decision Making
Protective decisions are often puzzling. Among other anomalies, people insure against non-catastrophic events, underinsure against catastrophic risks, and allow extraneous factors to influence insurance purchases and other protective decisions. Neither expected utility theory nor prospect theory can explain these anomalies satisfactorily. We propose a constructed-choice model for general decision making. The model departs from utility theory and prospect theory in its treatment of multiple goals and it suggests several different ways in which context can affect choice. To apply this model to the above anomalies, we consider many different insurance-related goals, organized in a taxonomy, and we consider the effects of context on goals, resources, plans and decision rules. The paper concludes by suggesting some prescriptions for improving individual decision making with respect to protective measures.
Productivity of Florida Springs: first semi-annual report to Biology Division, Office of Naval Research, progress from June 1, 1952 to January 31, 1953
Work has begun on studying the factors responsible for productivity
in the Florida springs, which are nearly constant temperature, constant
chemical, steady state giant laboratories. Progress has been made on five
aspects: qualitative description, quantitative description, completion
of knowledge of chemical factors, measurement of productivity , development
of productivity theory.
Measurement of the primary productivity in Silver Springs and Green
Cove Springs by two new methods: the raising of organisms in cages, and the
measurement of night & day differences in oxygen downstream agree roughly.
Production in these springs is greater than previous production figures reported
for marine, fresh water, and land areas. Instantaneous measures of production
show large variations with season, time of day, cloud cover. Production
estimates range from 11,000 lbs per acre per year to 70,000 lbs. glucose per
acre per year during daylight hours.
Essential stability of the springs environment has been shown with
respect to temperature, phosphorus, and plant cover. A correlation of species
number with lack of stability has been shown with insects. Quantitative
studies have shown very large plant base to pyramids of mass. Correlation
of marine invasion with chlorinity has been shown. The essential aspects of
pH regulated phosphorus geochemistry in Florida have been outlined. Some
theoretical ideas on productivity have been evolved. Mapping of sessile
organisms in springs and taxonomic identification of dominants are half
completed. Plans for second six months include measurement of herbivore
and carnivore production rates and completion of food chain efficiency
determinations in Silver Springs as a preparation for subsequent
comparisons between springs. (34pp.
Exercise-induced pulmonary hemorrhage: where are we now?
Citation: Poole, D. C., & Erickson, H. H. (2016). Exercise-induced pulmonary hemorrhage: where are we now? Veterinary Medicine-Research and Reports, 7, 133-148.
https://doi.org/10.2147/vmrr.s120421As the Thoroughbreds race for the final stretch, 44 hooves flash and thunder creating a cacophony of tortured air and turf. Orchestrated by selective breeding for physiology and biomechanics, expressed as speed, the millennia-old symphony of man and beast reaches its climax. At nearly 73 kilometers per hour (45 mph) over half a ton of flesh and bone dwarfs its limpet-like jockey as, eyes wild and nostrils flaring, their necks stretch for glory. Beneath each resplendent livery-adorned, latherin-splattered coat hides a monstrous heart trilling at 4 beats per second, and each minute, driving over 400 L (105 gallons) of oxygen-rich blood from lungs to muscles. Matching breath to stride frequency, those lungs will inhale 16 L (4 gallons) of air each stride moving >1,000 L/min in and out of each nostril - and yet failing. Engorged with blood and stretched to breaking point, those lungs can no longer redden the arterial blood but leave it dusky and cyanotic. Their exquisitely thin blood-gas barrier, a mere 10.5 mu m thick (1/50,000 of an inch), ruptures, and red cells invade the lungs. After the race is won and lost, long after the frenetic crowd has quieted and gone, that blood will clog and inflame the airways. For a few horses, those who bleed extensively, it will overflow their lungs and spray from their nostrils incarnadining the walls of their stall: a horrifically poignant canvas that strikes at horse racing's very core. That exercise-induced pulmonary hemorrhage (EIPH) occurs is a medical and physiological reality. That every reasonable exigency is not taken to reduce/prevent it would be a travesty. This review is not intended to provide an exhaustive coverage of EIPH for which the reader is referred to recent reviews, rather, after a brief reminder of its physiologic and pathologic bases, focus is brought on the latest developments in EIPH discovery as this informs state-of-the-art knowledge, the implementation of that knowledge and recommendations for future research and treatment
Productivity of Florida Springs: Second annual report to Biology Branch, Office of Naval Research progress from January 1 to December 31, 1954
Production measurements at different times of the year indicate a linear relationship of light intensity and overall production at about 8% of the visible light energy reaching plant level. Measurements of a coral reef at Eniwetok indicate 6%. Further evidence of breeding at all seasons but with a quantitative pulse in the seasons of maximum light indicates that the seasonal fluctuation in primary production is routed through reproduction rather than through major changes in populations. The succession of plants and anmals of the aufwuchs has been shown with glass slides and counts from Sagittaria blades. Losss of oxygen bubbles during the day and emergence of aquatic insects at night have been measured with funnels. Bell jar measurements are reported for bacterial metabolism on mud surfaces. pH determined CO2 uptake agrees with titration determinations. A few rough estimates of herbivore production have been made from caged snails, aufwuchs succession, and fish tagging. Nitrate uptake a night by aufwuchs communities has been confirmed in a circulating microcosm experiment as well as in bell jars in the springs. Distributions of oxygen and organisms have been used to criticize the saprobe stream classification system. Theoretical consideration of maximum photosynthetic rates in teh literature data indicates logarithmic rate variation inversely with organismal size just as for respiratory metabolism. Extreme pyramid shapes are thus shown for communities in which organismal size decreases up the food chain and for other communities with the same energy influx but with organismal size increasing up the food chain. Literature data is used to further demonstrate the validity of the optimum efficiency-maximum power principle for photosynthesis. Work on plants by Dr. Delle Natelson indicates essential stability of aquatic plant communities after 3 years and about 10-20% reproducibility in previous biomass estimates by Davis. Work on an animal picture of the fishery characteristics by Caldwell, Barry, and Odum is half completed. The study of aquatic insects in relationship to spring gradients by W.C. Sloan has been completed an an M.S. thesis. J. Yount has begun a study of affect of total productivity on community composition using aufwuchs organisms on glass slides placed in different current and light conditions in Silver Springs. (49pp.
EVIDENCE FOR IDENTITY OR CLOSE ASSOCIATION OF THE Fc RECEPTOR OF B LYMPHOCYTES AND ALLOANTIGENS DETERMINED BY THE Ir REGION OF THE H-2 COMPLEX
Immunoglobulin complexes, composed of heat-aggregated human Ig, were shown to bind to mouse B lymphocytes of a variety of strains, but not to either thymocytes or thymus-derived (T) lymphocytes under a variety of conditions. It was shown that this binding was not due to either natural human antibodies against mouse nor to nonspecific binding of human Ig by mouse lymphocytes. Such complexes were shown to bind to the same sites which bind mouse antibody-antigen complexes. This site is known as the Fc receptor. The binding of Ig complexes to mouse B lymphocytes was markedly inhibited by pretreatment of the lymphocytes with anti-H-2 antisera. A series of experiments indicated the specificity of this result, including the fact that this inhibition was shown not to be due to the artifact of shedding of H-2 antibody-antigen complexes, nor to nonspecific steric inhibition. The antibodies within anti-H-2 antisera which were responsible for this inhibition were specific for alloantigens associated with the Ir region of the H-2 complex (Ia antigens). Antiserum specific for these Ia antigens produced inhibition, whereas antisera specific for antigens determined by the K or D regions of the H-2 complex did not. Evidence was obtained using F1 hybrid cells that at least some Ia antigens of both parental types are expressed on every B lymphocyte (i.e. codominant expression). These data indicate that the Fc receptor and a series of alloantigens controlled by the Ir region of the H-2 complex are identical or closely associated on the B-lymphocyte surface membrane. This observation may have implications for the mechanism of control of the immune response
Comparative Effectiveness Research, COURAGE, and Technological Abandonment
When a major study finds that a widely used medical treatment is no better than a less expensive alternative, do physicians stop using it? Policymakers hope that comparative effectiveness research will identify less expensive substitutes for widely-used treatments, but physicians may be reluctant to abandon profitable therapies. We examine the impact of the COURAGE trial, which found that medical therapy is as effective as percutaneous coronary intervention (PCI) for patients with stable angina, on practice patterns. Using hospital discharge data from US community, Veterans Administration, and English hospitals, we detect a moderate decline in PCI volume post-COURAGE. However, many patients with stable angina continue to receive PCI. We do not find differences in PCI volume trends by reimbursement scheme or hospitals’ teaching status, ownership, or degree of vertical integration.
Maximum Activation of Thin Filaments at High Ionic Strength requires Bound Calcium and Rigor Myosin
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