3,300 research outputs found
Designing Information Markets for Decision Making
People often make important decisions based on information elicited from experts with uncertain preferences. We provide a theoretical rationale for the use of information markets in decision making tasks. Specifically, we show that markets for claims on decision-relevant variables can be efficient incentive schemes for eliciting information. Our model shows decision makers will subsidize liquidity in illiquid decision markets to gather valuable information. Our model also shows that the mere act of linking the decision to the market price will typically enhance liquidity in the market. Overall, our results highlight the potential for using information markets in diverse decision making tasks.
Quantifying Forest Ground Flora Biomass Using Proximal Sensing
Current focus on forest conservation and forest sustainability has increased the level of attention given to measures of ground flora in forest ecosystems. Traditionally, such data are collected via time- and resource-intensive methods of field identification, clipping, and weighing. With increased focus on community composition and structure measures of forest ground flora, the manner in which these data are collected must change. This project uses color and color infrared digital cameras to proximally sense forest ground flora and to develop regression models to predict green and dry biomass (g/m^) from the proximally sensed data. Traditional vegetative indices such as the Normalized Difference Vegetative Index (NDVI) and the Average Visible Reflectance Index (AVR) explained 35-45% of the variation in forest ground flora biomass. Adding individual color band variables, especially the red and near infrared bands, to the regression model allowed the model to explain 66% and 58% of the variation in green and dry biomass, respectively, present
Scientific Rationale and Requirements for a Global Seismic Network on Mars
Following a brief overview of the mission concepts for a Mars Global Network Mission as of the time of the workshop, we present the principal scientific objectives to be achieved by a Mars seismic network. We review the lessons for extraterrestrial seismology gained from experience to date on the Moon and on Mars. An important unknown on Mars is the expected rate of seismicity, but theoretical expectations and extrapolation from lunar experience both support the view that seismicity rates, wave propagation characteristics, and signal-to-noise ratios are favorable to the collection of a scientifically rich dataset during the multiyear operation of a global seismic experiment. We discuss how particular types of seismic waves will provide the most useful information to address each of the scientific objectives, and this discussion provides the basis for a strategy for station siting. Finally, we define the necessary technical requirements for the seismic stations
Feasibility of Infectious Prion Digestion Using Mild Conditions and Commercial Subtilisin
Two serine protease enzymes, subtilisin 309 and subtilisin 309-v,were used to digest brain homogenates containing high levels of prion infectivity using mildly alkaline conditions to investigate prion decontamination methods. To establish that PrPres infectivity was eliminated, we utilized the Rocky Mountain Laboratory (RML) mouse-adapted scrapie model system for bioassay. Only one digestion condition (subtilisin 309 at 138mAU/ml, 55 â—¦C and 14 h digestion time pH 7.9) was considered to be highly relevant statistically (P \u3c 0.001) compared to control, with 52% of challenged mice surviving until the end of the study period. In contrast, treatment of PrPres by autoclaving at 134 â—¦C or treatment with hypochlorite at a concentration of 20,000ppm completely protected mice from prionosis. Further, in vitro assays suggest that potential proteolytic based PrPres decontamination methods must use high enzyme concentration, pH values \u3e9.0, and elevated temperatures to be a safely efficacious, thereby limiting applicability on delicate surgical instruments and use in the environment
Plasticity of streptomyces coelicolor membrane composition under different growth conditions and during development
Streptomyces coelicolor is a model actinomycete that is well known for the diversity of its secondary metabolism and its complex life cycle. As a soil inhabitant, it is exposed to heterogeneous and frequently changing environmental circumstances. In the present work, we studied the effect of diverse growth conditions and phosphate depletion on its lipid profile and the relationship between membrane lipid composition and development in S. coelicolor. The lipid profile from cultures grown on solid media, which is closer to the natural habitat of this microorganism, does not resemble the previously reported lipid composition from liquid grown cultures of S. coelicolor. Wide variations were also observed across different media, growth phases, and developmental stages indicating active membrane remodeling. Ornithine lipids (OL) are phosphorus-free polar lipids that were accumulated mainly during sporulation stages, but were also major components of the membrane under phosphorus limitation. In contrast, phosphatidylethanolamine, which had been reported as one of the major polar lipids in the genus Streptomyces, is almost absent under these conditions. We identified one of the genes responsible for the synthesis of OL (SCO0921) and found that its inactivation causes the absence of OL, precocious morphological development and actinorhodin production. Our observations indicate a remarkable plasticity of the membrane composition in this bacterial species, reveal a higher metabolic complexity than expected, and suggest a relationship between cytoplasmic membrane components and the differentiation programs in S. coelicolor
Predicting, Preparing for, and Creating the Future: What Will Happen to Internal Medicine?
It is the year 2025. During the past 20 years, internal medicine as a discipline continued to become less prestigious, less respected, and more fragmented. As fewer medical students chose internal medicine as a career, residency programs began to close. Those that remained open filled with fewer graduates of US medical schools but filled with more US citizens who graduated from international medical schools, more graduates of osteopathic medical schools, and more foreign graduates of international medical schools. Due to lack of adequate remuneration and a shift of primary care provision from generalist physicians to nurse practitioners and physician assistants, training in general internal medicine as a patient care specialty ceased. Generalist internal medicine careers have been replaced by tracks designed to foster health services research or academic careers; internal medicine training graduates subspecialty physicians. Although the projected collapse of Medicare in 2019 was avoided, severe cuts in federal funding for undergraduate and graduate medical education programs forced medical schools and residency programs to compete for federal funds. As a result, medical school tuition became prohibitive, for-profit health care systems viewed medical education as a significant cost center and chose to limit the size of their residency programs, and community-based training programs could not withstand the financial pressures and closed. The result was a reduced supply of internists. Furthermore, compliance with the regulatory burden imposed by accrediting organizations—such as the Accreditation Council for Graduate Medical Education—drove individuals from sustained careers in education, further impacting the viability of training programs
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