661 research outputs found

    The Parasitoid Complex of Forest Tent Caterpillar, \u3ci\u3eMalacosoma Disstria\u3c/i\u3e (Lepidoptera: Lasiocampidae), in Eastern Wyoming Shelterbelts

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    A parasitoid complex affecting the forest tent caterpillar, Malacosoma disstria, was investigated during 1978-79 in shelterbelts in eastern Wyoming. Egg parasitoids included five species: Ablerus clisiocampae, Ooencyrtus clisiocampae, Telenomus clisiocampae, Tetrastichus sp. 1 and Telenomus sp. Thirteen hymenopterous species and five dipterous species were reared from larvae and pupae of the forest tent caterpillar. The most common 5th-instar larval parasitoids were the tachinid flies, Lespesia archippivora and Archytas lateralis. Of the pupal parasitoids reared, 640/0 were Diptera and 36% were Hymenoptera. Four previously unrecorded parasitoids of M. disstria were reared: Cotesia alalantae, Macrocentrus irridescens, Pimpla sanguinipes erythropus, and Lespesia flavifrons.

    An extension of the Markowitz portfolio selection model to include variable transactions' costs, short sales, leverage policies and taxes

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    Based on the earlier paper, Portfolio selection, in the Journal of finance

    An inter-temporal model for investment management,

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    Based on the author's Doctoral dissertation, An adaptive model for investment management, Carnegie-Mellon University, 1967

    A linear programming model for short term financial planning under uncertainty

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    Performance Assessment of Diffuse Optical Spectroscopic Imaging Instruments in a 2-Year Multicenter Breast Cancer Trial

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    We present a framework for characterizing the performance of an experimental imaging technology, diffuse optical spectroscopic imaging (DOSI), in a 2-year multicenter American College of Radiology Imaging Network (ACRIN) breast cancer study (ACRIN-6691). DOSI instruments combine broadband frequency-domain photon migration with time-independent near-infrared (650 to 1000 nm) spectroscopy to measure tissue absorption and reduced scattering spectra and tissue hemoglobin, water, and lipid composition. The goal of ACRIN-6691 was to test the effectiveness of optically derived imaging endpoints in predicting the final pathologic response of neoadjuvant chemotherapy (NAC). Sixty patients were enrolled over a 2-year period at participating sites and received multiple DOSI scans prior to and during 3- to 6-month NAC. The impact of three sources of error on accuracy and precision, including different operators, instruments, and calibration standards, was evaluated using a broadband reflectance standard and two different solid tissue-simulating optical phantoms. Instruments showed \u3c 0.0010 mm−1 (10.3%) and 0.06 mm−1 (4.7%) deviation in broadband absorption and reduced scattering, respectively, over the 2-year duration of ACRIN-6691. These variations establish a useful performance criterion for assessing instrument stability. The proposed procedures and tests are not limited to DOSI; rather, they are intended to provide methods to characterize performance of any instrument used in translational optical imaging

    Clinical study of the factors affecting radioulnar deviation of the wrist joint

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    <p>Abstract</p> <p>Background</p> <p>The radioulnar carpal joint is critical for hand and wrist function. Radioulnar deviation indicates distal radioulnar joint flexibility and reflects the structure and function of the carpal bones, ulna, radius and ligaments. The present study examined whether radioulnar deviation is affected by gender, manual labor, playing a musical instrument, playing sport, handedness, previous fracture or prior inflammation. The study used clinical findings based on anatomical landmarks</p> <p>Methods</p> <p>The ulnar, radial and total deviations for both left and right hands were measured in 300 subjects (157 men and 143 women) of mean age 21.7 years. Measurements were made with the forearm in a fixed pronated position using a novel specially designed goniometer. The gender of each subject was recorded, and information on playing of sport, playing a musical instrument, manual labor, handedness, and history of fracture or inflammation was sought. Data were analyzed using a multifactor ANOVA test.</p> <p>Results</p> <p>No statistically significant difference (p-value > 0.05) was found between those comparing groups except the total deviation of athletes' left hand versus the total deviation of non athletes' left hand (p-value 0.041 < 0.05) and the radial deviation of manual workers' left hand and non manual workers' left hand (p-value 0.002 < 0.05).</p> <p>Conclusions</p> <p>This study was based on clinical findings using anatomical landmarks. We found that manual workers and athletes showed greater left hand flexibility. This suggests that activities that place chronic stress on the radiocarpal joint can independently affect radioulnar deviation.</p

    Estimating required information size by quantifying diversity in random-effects model meta-analyses

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    <p>Abstract</p> <p>Background</p> <p>There is increasing awareness that meta-analyses require a sufficiently large information size to detect or reject an anticipated intervention effect. The required information size in a meta-analysis may be calculated from an anticipated <it>a priori </it>intervention effect or from an intervention effect suggested by trials with low-risk of bias.</p> <p>Methods</p> <p>Information size calculations need to consider the total model variance in a meta-analysis to control type I and type II errors. Here, we derive an adjusting factor for the required information size under any random-effects model meta-analysis.</p> <p>Results</p> <p>We devise a measure of diversity (<it>D</it><sup>2</sup>) in a meta-analysis, which is the relative variance reduction when the meta-analysis model is changed from a random-effects into a fixed-effect model. <it>D</it><sup>2 </sup>is the percentage that the between-trial variability constitutes of the sum of the between-trial variability and a sampling error estimate considering the required information size. <it>D</it><sup>2 </sup>is different from the intuitively obvious adjusting factor based on the common quantification of heterogeneity, the inconsistency (<it>I</it><sup>2</sup>), which may underestimate the required information size. Thus, <it>D</it><sup>2 </sup>and <it>I</it><sup>2 </sup>are compared and interpreted using several simulations and clinical examples. In addition we show mathematically that diversity is equal to or greater than inconsistency, that is <it>D</it><sup>2 </sup>≥ <it>I</it><sup>2</sup>, for all meta-analyses.</p> <p>Conclusion</p> <p>We conclude that <it>D</it><sup>2 </sup>seems a better alternative than <it>I</it><sup>2 </sup>to consider model variation in any random-effects meta-analysis despite the choice of the between trial variance estimator that constitutes the model. Furthermore, <it>D</it><sup>2 </sup>can readily adjust the required information size in any random-effects model meta-analysis.</p
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