1,309 research outputs found

    Mandated Health Insurance Benefits and the Utilization and Outcomes of Infertility Treatments

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    During the last two decades, the treatment of infertility has improved dramatically. These treatments, however, are expensive and rarely covered by insurance, leading many states to adopt regulations mandating that health insurers cover them. In this paper, we explore the effects of benefit mandates on the utilization and outcomes of infertility treatments. We find that use of infertility treatments is significantly greater in states adopting comprehensive versions of these mandates. While greater utilization had little impact on the number of deliveries, mandated coverage was associated with a relatively large increase in the probability of a multiple birth. For relatively low fertility patients who responded to the expanded insurance coverage, treatment was often unsuccessful and did not result in a live birth. For relatively high fertility patients, in contrast, treatment often led to a multiple, rather than a singleton, birth. We also find evidence that the beneficial effects on the intensive treatment margin that have been proposed in other studies are relatively small. We conclude that, while benefit mandates potentially solve a problem of adverse selection in this market, these benefits must be weighed against the costs of the significant moral hazard in utilization they induce.

    Wing analysis using a transonic potential flow computational method

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    The ability of the method to compute wing transonic performance was determined by comparing computed results with both experimental data and results computed by other theoretical procedures. Both pressure distributions and aerodynamic forces were evaluated. Comparisons indicated that the method is a significant improvement in transonic wing analysis capability. In particular, the computational method generally calculated the correct development of three-dimensional pressure distributions from subcritical to transonic conditions. Complicated, multiple shocked flows observed experimentally were reproduced computationally. The ability to identify the effects of design modifications was demonstrated both in terms of pressure distributions and shock drag characteristics

    Wind tunnel and analytical investigation of over-the-wing propulsion/air frame interferences for a short-haul aircraft at Mach numbers from 0.6 to 0.78

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    Results of analytical calculations and wind tunnel tests at cruise speeds of a representative four engine short haul aircraft employing upper surface blowing (USB) with a supercritical wing are discussed. Wind tunnel tests covered a range of Mach number M from 0.6 to 0.78. Tests explored the use of three USB nozzle configurations. Results are shown for the isolated wing body and for each of the three nozzle types installed. Experimental results indicate that a low angle nacelle and streamline contoured nacelle yielded the same interference drag at the design Mach number. A high angle powered lift nacelle had higher interference drag primarily because of nacelle boattail low pressures and flow separation. Results of varying the spacing between the nacelles and the use of trailing edge flap deflections, wing upper surface contouring, and a convergent-divergent nozzle to reduce potential adverse jet effects were also discussed. Analytical comparisons with experimental data, made for selected cases, indicate favorable agreement

    Alpine Glacier Reveals Ecosystem Impacts of Europe’s Prosperity and Peril Over the Last Millennium

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    Information about past ecosystem dynamics and human activities is stored in the ice of Colle Gnifetti glacier in the Swiss Alps. Adverse climatic intervals incurred crop failures and famines and triggered reestablishment of forest vegetation but also societal resilience through innovation. Historical documents and lake sediments record these changes at local—regional scales but often struggle to comprehensively document continental-scale impacts on ecosystems. Here, we provide unique multiproxy evidence of broad-scale ecosystem, land use, and climate dynamics over the past millennium from a Colle Gnifetti microfossil and oxygen isotope record. Microfossil data indicate that before 1750 CE forests and fallow land rapidly replaced crop cultivation during historically documented societal crises caused by climate shifts and epidemics. Subsequently, with technology and the introduction of more resilient crops, European societies adapted to the Little Ice Age cold period, but resource overexploitation and industrialization led to new regional to global-scale environmental challenges

    Continuous isotopic composition measurements of tropospheric CO<sub>2</sub> at Jungfraujoch (3580 m a.s.l.), Switzerland: real-time observation of regional pollution events

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    A quantum cascade laser based absorption spectrometer (QCLAS) is applied for the first time to perform in situ, continuous and high precision isotope ratio measurements of CO<sub>2</sub> in the free troposphere. Time series of the three main CO<sub>2</sub> isotopologue mixing ratios (<sup>12</sup>C<sup>16</sup>CO<sub>2</sub>, <sup>13</sup>C<sup>16</sup>CO<sub>2</sub> and <sup>12</sup>C<sup>18</sup>O<sup>16</sup>O) have simultaneously been measured at one second time resolution over two years (from August 2008 to present) at the High Altitude Research Station Jungfraujoch (3580 m a.s.l., Switzerland). This work focuses on periods in February 2009 only, when sudden and pronounced enhancements in the tropospheric CO<sub>2</sub> were observed. These short-term changes were closely correlated with variations in CO mixing ratios measured at the same site, indicating combustion related emissions as potential source. The analytical precision of 0.046&permil; (at 50 s integration time) for both &delta;<sup>13</sup>C and &delta;<sup>18</sup>O and the high temporal resolution allowed the application of the Keeling plot method for source signature identification. The spatial origin of these CO<sub>2</sub> emission sources was then determined by backward Lagrangian particle dispersion simulations

    Effects of relative humidity on aerosol light scattering in the Arctic

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    Aerosol particles experience hygroscopic growth in the ambient atmosphere. Their optical properties – especially the aerosol light scattering – are therefore strongly dependent on the ambient relative humidity (RH). In-situ light scattering measurements of long-term observations are usually performed under dry conditions (RH&amp;gt;30–40%). The knowledge of this RH effect is of eminent importance for climate forcing calculations or for the comparison of remote sensing with in-situ measurements. This study combines measurements and model calculations to describe the RH effect on aerosol light scattering for the first time for aerosol particles present in summer and fall in the high Arctic. For this purpose, a field campaign was carried out from July to October 2008 at the Zeppelin station in Ny-Ålesund, Svalbard. The aerosol light scattering coefficient &amp;sigma;&lt;sub&gt;sp&lt;/sub&gt;(&amp;lambda;) was measured at three distinct wavelengths (λ=450, 550, and 700 nm) at dry and at various, predefined RH conditions between 20% and 95% with a recently developed humidified nephelometer (WetNeph) and with a second nephelometer measuring at dry conditions with an average RH&amp;lt;10% (DryNeph). In addition, the aerosol size distribution and the aerosol absorption coefficient were measured. The scattering enhancement factor &lt;i&gt;f&lt;/i&gt;(RH, &amp;lambda;) is the key parameter to describe the RH effect on &amp;sigma;&lt;sub&gt;sp&lt;/sub&gt;(&amp;lambda;) and is defined as the RH dependent &amp;sigma;&lt;sub&gt;sp&lt;/sub&gt;(RH, &amp;lambda;) divided by the corresponding dry &amp;sigma;&lt;sub&gt;sp&lt;/sub&gt;(RH&lt;sub&gt;dry&lt;/sub&gt;, &amp;lambda;). During our campaign the average &lt;i&gt;f&lt;/i&gt;(RH=85%, λ=550 nm) was 3.24&amp;plusmn;0.63 (mean &amp;plusmn; standard deviation), and no clear wavelength dependence of &lt;i&gt;f&lt;/i&gt;(RH, &amp;lambda;) was observed. This means that the ambient scattering coefficients at RH=85% were on average about three times higher than the dry measured in-situ scattering coefficients. The RH dependency of the recorded &lt;i&gt;f&lt;/i&gt;(RH, &amp;lambda;) can be well described by an empirical one-parameter equation. We used a simplified method to retrieve an apparent hygroscopic growth factor &lt;i&gt;g&lt;/i&gt;(RH), defined as the aerosol particle diameter at a certain RH divided by the dry diameter, using the WetNeph, the DryNeph, the aerosol size distribution measurements and Mie theory. With this approach we found, on average, &lt;i&gt;g&lt;/i&gt;(RH=85%) values to be 1.61&amp;plusmn;0.12 (mean&amp;plusmn;standard deviation). No clear seasonal shift of &lt;i&gt;f&lt;/i&gt;(RH, &amp;lambda;) was observed during the 3-month period, while aerosol properties (size and chemical composition) clearly changed with time. While the beginning of the campaign was mainly characterized by smaller and less hygroscopic particles, the end was dominated by larger and more hygroscopic particles. This suggests that compensating effects of hygroscopicity and size determined the temporal stability of &lt;i&gt;f&lt;/i&gt;(RH, &amp;lambda;). During sea salt influenced periods, distinct deliquescence transitions were observed. At the end we present a method on how to transfer the dry in-situ measured aerosol scattering coefficients to ambient values for the aerosol measured during summer and fall at this location

    Compilation of Selected Vegetable Crop Reports Dealing with Research and Demonstration Plots Located at the Muck Crops Branch, 1983

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    Spinach cultivar trials, 1982 ; Celery cultivar trials, 1982 / James M. Pisarczyk and Richard L. Hassell -- Potato cultivar trials, 1982 / James M. Pisarczyk -- Celery transplant study, 1982 / Richard L. Hassell -- Parsley 1982 variety trials ; Onion 1982 variety trials ; Broccoli variety trials, 1982 / Richard L. Hassell -- Carrot variety trials, 1982 / R. Mack Riedel and Richard C. Henne -- Control of early blight of celery with fungicides, 1982 ; Control of crucifer downy mildew with fungicide sprays, 1982 / Randall C. Rowe and Richard L. Hassell -- Synergistic interaction between species of lesion nematodes and Verticillium dahliae, 1982 / R. M. Riedel and R. C. Rowe -- Transplants vs. bare-root in controlling root-knot nematode / R. M. Riedel -- Rotations for control of root-knot nematode / R. M. Riedel and J. A. Chatfield -- Fertilizer guidelines for vegetable crops grown on muck soils in Ohio / William M. Brooks, E. C. Wittmeyer and Richard Hassel
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