904 research outputs found

    Adoption and Diffusion of At-Home Medical Tests

    Get PDF
    The purpose of this study is to understand the at-home medical test market including the medical and regulatory requirements to create at-home medical tests, as well as the market factors that influence consumer adoption in the context of the COVID-19 pandemic. To address testing shortages of COVID-19 tests companies created at-home tests which were rapidly approved by the FDA, bringing at-home testing to the forefront. History of at-home health testing is reviewed, the medical requirements for creating them, and how the pandemic has affected such testing. Tables are also included to demonstrate currently available tests and potential future tests. The research draws attention to two categories of at-home tests 1) collection kits and 2) testing kits, both presenting opportunities for test developers. Companies interested in bringing at-home medical tests to the market must decide if they will utilize a preexisting laboratory test or develop a new test and if the tests will be physician ordered or sold directly to the consumer. Our investigation focuses on the effect COVID-19 has had on the at-home testing market which has been explored through traditional marketing concepts, the Rogers (2003) adoption and diffusion of innovations’ framework and critical success factors

    Mapping Weekly Rangeland Vegetation Productivity Using MODIS Algorithms

    Get PDF
    The great spatial extent of rangelands combined with recent emphasis on rangeland health has prompted a need for more efficient and cost effective management tools. The Moderate Resolution Imaging Spectroradiometer (MODIS) sensor of the Earth Observing System (EOS) will offer improved and more timely monitoring of rangeland vegetation, and, unlike any previous satellite sensor, the publicly available MODIS data stream will include estimates of rangeland productivity. These estimations of rangeland productivity can be used regionally for measuring biomass production and will be available every eight-days, with global coverage at 1- km^ resolution. MODIS derived estimates of rangeland productivity combine remote sensing information with daily meteorological data as inputs to a mathematical model of photosynthetic conversion of solar radiation into plant carbohydrates. Vegetation productivity is .a measure of rangeland vegetation vigor and growth capacity, which are important components of rangeland management and health assessment. Using MODIS data, it will be possible to characterize rangeland vegetation seasonality, estimate herbage quantity and, monitor the rates and trends of change in primary production. Consistent, objective and frequent productivity estimates will be available for even the most inaccessible rangelands. Potential applications of weekly and annual productivity estimates are demonstrated on the Shoshone BLM Administrative District and a larger portion of the Interior Northwestern United States. Productivity estimates were derived using Advanced Very High-Resolution Radiometer data as a surrogate for the MODIS data stream. Shrub and grassland vegetation seasonality for 1991 was characterized. Herbage quantity was estimated from the 1993 shrub and grassland regional net primary production. A 5-year average productivity from 1990 - 1994 and departures from that average were calculated for the years 1991 and 1993. The measures of departure indicated that 1991 was regionally less productive and 1993 more productive than the five year average. Collaboration between rangeland scientists and managers is necessary to realize the potential for EOS-derived vegetation productivity as a management tool. Future research will include field calibration of the productivity algorithms and exploration of new techniques for using EOS-derived productivity measures for rangeland management. Measures of rangeland productivity could become part of an integrated rangeland system analysis. This may permit differentiation between anthropogenic, biotic, and abiotic factors as the primary cause of declining productivity. Other research may include customization of biome properties for selected regions

    All plug-in electric vehicles are not the same: Predictors of preference for a plug-in hybrid versus a battery-electric vehicle

    Get PDF
    This study analyzes data from a survey of drivers (n = 1080) administered in late 2013 to assess factors that influence potential car buyers to consider two different types of plug-in electric vehicles (PEVs) in the United States: plug-in hybrid electric vehicles (PHEVs) and battery electric vehicles (BEVs). The results indicate distinct profiles of respondents preferring PHEVs, which have a gasoline backup engine, versus battery BEVs, which rely solely on a battery for power. Respondents interested in selecting a PHEV consider it more for its economic benefits, such as reduced gasoline and maintenance expenditures. Respondents preferring a BEV are drawn to its environmental and technological appeal. The absence of range anxiety for PHEV is a major factor influencing potential PEV buyers

    Crested macaque facial movements are more intense and stereotyped in potentially risky social interactions

    Get PDF
    Ambiguity in communicative signals may lead to misunderstandings and thus reduce the effectiveness of communication, especially in unpredictable interactions such as between closely matched rivals or those with a weak social bond. Therefore, signals used in these circumstances should be less ambiguous, more stereotyped and more intense. To test this prediction, we measured facial movements of crested macaques (Macaca nigra) during spontaneous social interaction, using the Facial Action Coding System for macaques (MaqFACS). We used linear mixed models to assess whether facial movement intensity and variability varied according to the interaction outcome, the individuals' dominance relationship and their social bond. Movements were least intense and most variable in affiliative contexts, and more intense in interactions between individuals who were closely matched in terms of dominance rating. We found no effect of social bond strength. Our findings provide evidence for a reduction in ambiguity of facial behaviour in risky social situations but do not demonstrate any mitigating effect of social relationship quality. The results indicate that the ability to modify communicative signals may play an important role in navigating complex primate social interactions. This article is part of the theme issue ‘Cognition, communication and social bonds in primates’

    Alan Greenspan, the Quants and Stochastic Optimal Control

    Get PDF
    Alan Greenspan's paper (March 2010) presents his retrospective view of the crisis. His theme has several parts. First, the housing price bubble, its subsequent collapse and the financial crisis were not predicted either by the market, the FED, the IMF or the regulators in the years leading to the current crisis. Second, financial intermediation tried to function on too thin layer of capital - high leverage - owing to a misreading of the degree of risk embodied in ever more complex financial products and markets. Third, the breakdown was unpredictable and inevitable, given the 'excessive' leverage - or low capital - of the financial intermediaries. The proposed legislation for the 'reform' of the financial system requires that the FED "identify, measure, manage and mitigate risks to the financial stability of the United States". The focus is upon capital requirements or debt ratios. The 'Quants' ignored systemic risk and just focused upon risk transfer in very liquid markets. The FED, IMF, Treasury and the 'Quants'/market lacked the appropriate tools of analysis to answer the following questions: what is an optimal leverage or capital requirement that balances the expected growth against risk? What are theoretically founded early warning signals of a crisis? The author explains why the application of stochastic optimal control (SOC)/dynamic risk management is an effective approach to determine the optimal degree of leverage, the optimum and excessive risk and the probability of a debt crisis. The theoretically derived early warning signal of a crisis is the excess debt ratio, equal to the difference between the actual and optimal ratio. The excess debt starting from 2004-05 indicated that a crisis was most likely. This SOC analysis should be used by those charged with surveillance of financial markets

    Refined Neutron-Star Mass Determinations for Six Eclipsing X-Ray Pulsar Binaries

    Full text link
    We present an improved method for determining the mass of neutron stars in eclipsing X-ray pulsar binaries and apply the method to six systems, namely Vela X-1, 4U 1538-52, SMC X-1, LMC X-4, Cen X-3, and Her X-1. In previous studies to determine neutron star mass, the X-ray eclipse duration has been approximated analytically by assuming the companion star is spherical with an effective Roche lobe radius. We use a numerical code based on Roche geometry with various optimizers to analyze the published data for these systems, which we supplement with new spectroscopic and photometric data for 4U 1538-52. This allows us to model the eclipse duration more accurately and thus calculate an improved value for the neutron star mass. The derived neutron star mass also depends on the assumed Roche lobe filling factor beta of the companion star, where beta = 1 indicates a completely filled Roche lobe. In previous work a range of beta between 0.9 and 1.0 was usually adopted. We use optical ellipsoidal lightcurve data to constrain beta. We find neutron star masses of 1.77 +/- 0.08 M_{sun} for Vela X-1, 0.87 +/- 0.07 M_{sun} for 4U 1538-52 (eccentric orbit), 1.00 +/- 0.10 M_{sun} for 4U 1538-52 (circular orbit), 1.04 +/- 0.09 M_{sun} for SMC X-1, 1.29 +/- 0.05 M_{sun} for LMC X-4, 1.49 +/- 0.08 M_{sun} for Cen X-3, and 1.07 +/- 0.36 M_{sun} for Her X-1. We discuss the limits of the approximations that were used to derive the earlier mass determinations, and we comment on the implications our new masses have for observationally refining the upper and lower bounds of the neutron star mass distribution.Comment: 10 figures, accepted for publication in The Astrophysical Journa

    Gulf Coast Ticks (Amblyomma maculatum) and Rickettsia parkeri, United States

    Get PDF
    Geographic distribution of Rickettsia parkeri in its US tick vector, Amblyomma maculatum, was evaluated by PCR. R. parkeri was detected in ticks from Florida, Georgia, Kentucky, Mississippi, Oklahoma, and South Carolina, which suggests that A. maculatum may be responsible for additional cases of R. parkeri rickettsiosis throughout much of its US range
    corecore