A teleoperated unmanned rotorcraft flight test technique

NASA and the U.S. Army are jointly developing a teleoperated unmanned rotorcraft research platform at the National Aeronautics and Space Administration (NASA) Langley Research Center. This effort is intended to provide the rotorcraft research community an intermediate step between wind tunnel rotorcraft studies and full scale flight testing. The research vehicle is scaled such that it can be operated in the NASA Langley 14- by 22-Foot Subsonic Tunnel or be flown freely at an outside test range. This paper briefly describes the system's requirements and the techniques used to marry the various technologies present in the system to meet these requirements. The paper also discusses the status of the development effort

An Integrated Analysis of Radial Velocities in Planet Searches

We discuss a Bayesian approach to the analysis of radial velocities in planet searches. We use a combination of exact and approximate analytic and numerical techniques to efficiently evaluate chi-squared for multiple values of orbital parameters, and to carry out the marginalization integrals for a single planet including the possibility of a long term trend. The result is a robust algorithm that is rapid enough for use in real time analysis that outputs constraints on orbital parameters and false alarm probabilities for the planet and long term trend. The constraints on parameters and odds ratio that we derive compare well with previous calculations based on Markov Chain Monte Carlo methods, and we compare our results with other techniques for estimating false alarm probabilities and errors in derived orbital parameters. False alarm probabilities from the Bayesian analysis are systematically higher than frequentist false alarm probabilities, due to the different accounting of the number of trials. We show that upper limits on the velocity amplitude derived for circular orbits are a good estimate of the upper limit on the amplitude of eccentric orbits for eccentricities less than about 0.5.Comment: 16 pages, 9 figures, to appear in MNRA

Beyond Context: Social Facts as Case-Specific Evidence

Experts often seek to apply social science to the facts of a particular case. Sometimes experts link social science findings to cases using only their expert judgment, and other times experts conduct case-specific research using social science principles and methods to produce case-specific evidence. This Article argues against expert judgment as the means of linking general social science to specific cases, and for the use of methodologically rigorous case-specific research to produce ¿social facts,¿ or case-specific evidence derived from social science principles. We explain the many ways that social fact studies can be conducted to yield reliable case-specific opinions, and we dispel the view that litigation poses insurmountable barriers to the conduct of case-specific empirical research. Social fact studies are feasible for both plaintiffs and defendants, and they provide much sounder conclusions about the relevance of social science to a litigated case than does linkage via expert judgment

Toward Improving Interventions Against Toxoplasmosis by Identifying Routes of Transmission Using Sporozoite- specific Serological Tools

Background. Horizontal transmission of Toxoplasma gondii occurs primarily via ingestion of environmental oocysts or con- sumption of undercooked/raw meat containing cyst-stage bradyzoites. The relative importance of these 2 transmission routes remains unclear. Oocyst infection can be distinguished from bradyzoite infection by identification of immunoglobulin G (IgG) antibodies against T. gondii embryogenesis-related protein (TgERP). These antibodies are, however, thought to persist for only 6–8 months in human sera, limiting the use of TgERP serology to only those patients recently exposed to T. gondii. Yet recent sero- logical survey data indicate a more sustained persistence of anti-TgERP antibodies. Elucidating the duration of anti-TgERP IgG will help to determine whether TgERP serology has epidemiological utility for quantifying the relative importance of different routes of T. gondii transmission. Methods. We developed a serocatalytic mathematical model to capture the change in seroprevalence of non-stage-specific IgG and anti-TgERP IgG antibodies with human age. The model was fitted to published datasets collected in an endemic region of Brazil to estimate the duration of anti-TgERP IgG antibodies, accounting for variable age–force of infection profiles and uncertainty in the diagnostic performance of TgERP serology. Results. We found that anti-TgERP IgG persists for substantially longer than previously recognized, with estimates ranging from 8.3 to 41.1 years. The Brazilian datasets were consistent with oocysts being the predominant transmission route in these settings. Conclusions. The longer than previously recognized duration of anti-TgERP antibodies indicates that anti-TgERP serology could be a useful tool for delineating T. gondii transmission routes in human populations. TgERP serology may therefore be an important epidemiological tool for informing the design of tailored, setting-specific public health information campaigns and interventions

Genotypic Variation in Constitutive and Induced Resistance in Grapes against Spider Mite (Acari: Tetranychidae) Herbivores

We examined genotypic variation in constitutive and induced resistance in grapes against Willamette spider mites, Eotetranychus willametti Ewing, and Pacific spider mites, Tetranychus pacificus McGregor, 2 common species of tetranychid mites found in California vineyards. We found evidence that early-season injury by Pacific mites induced resistance against subsequent Willamette mite populations but early-season injury by Willamette mites did not induce resistance against subsequent Willamette mite populations. Significant levels of induction were detected for several cultivars of the Old World species Vitis vinifera L. as well as the North American species V. calif arnica Bentham. Phylogenetic relationships among grape genotypes explained little of the variation we observed in induced resistance. Phylogenetic relatedness among grapes did help explain patterns of constitutive resistance for Pacific mites; cultivars of V. vinifera L. tended to be susceptible, whereas North American species were resistant. Wi11amette mites, however, performed well on some Old World cultivars and 2 North American species of Vitis that are native to California. We did not find any strong evidence of a negative correlation between constitutive resistance and strength of induction for these grape genotypes. Our results show that several factors contribute to variation in constitutive and induced resistance in grapes against these 2 species of spider mites, including grape genotype, previous history of mite injury (induction), the species of mite causing previous injury, and to some extent, phylogenetic relatedness among grapes. We also suspect that mite genotype has important influence