570 research outputs found

    Auctions Versus Negotiations in Procurement: An Empirical Analysis

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    Should the buyer of a customized good use competitive bidding or negotiation to select a contractor? To shed light on this question, we offer a framework that compares auctions with negotiations. We then examine a comprehensive data set of private sector building contracts awarded in Northern California during the years 1995-2000. The analysis suggests a number of potential limitations to the use of auctions. Auctions perform poorly when projects are complex, contractual design is incomplete and there are few available bidders. Furthermore, auctions stifle communication between buyers and the sellers, preventing the buyer from utilizing the contractor's expertise when designing the project. Some implications of these results for procurement in the public sector are discussed.

    The radial velocity search for extrasolar planets

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    Radial velocity measurements are being made to search for planets orbiting stars other than the Sun. The reflex acceleration induced on stars by planets can be sensed by measuring the small, slow changes in the line-of-site velocities of stars. To detect these planetary perturbations, the data series must be made on a uniform instrumental scale for as long as it takes a planet to orbit its star. A spectrometer of extreme stability and unprecedented sensitivity to changes in stellar radial velocities was operated

    New Research by CCD Scanning for Comets and Asteroids

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    The purpose of Spacewatch is to explore the various populations of small objects within the solar system. Spacewatch provides data for studies of comets and asteroids, finds potential targets for space missions, and provides information on the environmental problem of possible impacts. Moving objects are discovered by scanning the sky with charge-coupled devices (CCDs) on the 0.9-meter Spacewatch Telescope of the University of Arizona on Kitt Peak. Each Spacewatch scan consists of three drift scan passes over an area of sky using a CCD filtered to a bandpass of 0.5-1.0 microns (approximately V+R+I with peak sensitivity at 0.7 micron). The effective exposure time for each pass is 143 seconds multiplied by the secant of the declination. We have been finding some 30,000 new asteroids per year and applying their statistics to the study of the collisional history of the solar system. As of the end of the observing run of Nov. 1997, Spacewatch had found a total of 153 Near-Earth Asteroids (NEAs) and 8 new comets since the project began in the 1980s, and had recovered one lost comet. The total number of NEAs found by Spacewatch big enough to be hazardous if they were to impact the Earth is 36. Spacewatch is also efficient in recovery of known comets and has detected and reported positions for more than 137,000 asteroids, mostly new ones in the main belt, including more than 16,000 asteroids designated by the Minor Planet Center (MPC)

    Discovery of near-Earth asteroids by CCD scanning

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    The found near-Earth asteroid are different objects with peculiar orbits. With the new technique of CCD scanning we entered the domain of the smallest, the fastest, and the closest near-Earth asteroids. The results are presented

    Simple and objective prediction of survival in patients with lung cancer: staging the host systemic inflammatory response

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    Background. Prediction of survival in patients diagnosed with lung cancer remains problematical. The aim of the present study was to examine the clinical utility of an established objective marker of the systemic inflammatory response, the Glasgow Prognostic Score, as the basis of risk stratification in patients with lung cancer. Methods. Between 2005 and 2008 all newly diagnosed lung cancer patients coming through the multidisciplinary meetings (MDTs) of four Scottish centres were included in the study. The details of 882 patients with a confirmed new diagnosis of any subtype or stage of lung cancer were collected prospectively. Results. The median survival was 5.6 months (IQR 4.8–6.5). Survival analysis was undertaken in three separate groups based on mGPS score. In the mGPS 0 group the most highly predictive factors were performance status, weight loss, stage of NSCLC, and palliative treatment offered. In the mGPS 1 group performance status, stage of NSCLC, and radical treatment offered were significant. In the mGPS 2 group only performance status and weight loss were statistically significant. Discussion. This present study confirms previous work supporting the use of mGPS in predicting cancer survival; however, it goes further by showing how it might be used to provide more objective risk stratification in patients diagnosed with lung cancer

    Long-Term Results Of Autologous Hematopoietic Cell Transplantation For Peripheral T Cell Lymphoma: The Stanford Experience

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    AbstractThe peripheral T cell lymphomas (PTCL) carry a worse prognosis compared to B cell non-Hodgkin lymphoma. There is no uniform standard therapy for PTCL, and autologous hematopoietic cell transplant (AHCT) is often offered as consolidation in first remission or at relapse because of the poor outcomes with conventional therapy. We conducted a retrospective review of patients who underwent AHCT for PTCL from 1989 to 2006. Fifty-three cases were identified consisting of systemic anaplastic large cell (n = 18), PTCL unspecified (n = 17), angioimmunoblastic (n = 9), nasal type extranodal NK/T (n = 7), hepatosplenic (n = 2), and adult T cell leukemia/lymphoma (n = 1). Fifteen patients were transplanted in first complete or partial response (CR1/PR1), 32 in second or beyond CR or PR (CR2/PR2+), and 11 with primary refractory disease (REF). With a median follow-up was 5 years (range: 1.0-11.5), the 5-year progression-free survival (PFS) and overall survival (OS) were 25% and 48%, respectively. Disease status at AHCT had a significant impact on PFS and OS. The 5-year PFS for patients in CR1/PR1, CR2/PR2+, and REF was 51%, 12%, and 0%, respectively, and the corresponding figures for OS were 76%, 40%, and 30%, respectively. The pretransplant factors that impacted survival were disease status and the number of prior regimens. Histology, age, sex, stage, B symptoms, bone marrow involvement, and duration of first response did not significantly affect PFS or OS. Based on these results, AHCT as consolidation therapy in first complete or partial response may offer a durable survival benefit. However, AHCT with conventional salvage chemotherapy has minimal durable benefit in patients with relapsed or refractory PTCL, and thus novel strategies and/or allogeneic HCT should be more aggressively explored in lieu of AHCT for relapsed/ refractory PTCL

    Genetic influence on family socioeconomic status and children's intelligence

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    Environmental measures used widely in the behavioral sciences show nearly as much genetic influence as behavioral measures, a critical finding for interpreting associations between environmental factors and children's development. This research depends on the twin method that compares monozygotic and dizygotic twins, but key aspects of children's environment such as socioeconomic status (SES) cannot be investigated in twin studies because they are the same for children growing up together in a family. Here, using a new technique applied to DNA from 3000 unrelated children, we show significant genetic influence on family SES, and on its association with children's IQ at ages 7 and 12. In addition to demonstrating the ability to investigate genetic influence on between-family environmental measures, our results emphasize the need to consider genetics in research and policy on family SES and its association with children's IQ

    Predicting educational achievement from genomic measures and socioeconomic status

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    The two best predictors of children's educational achievement available from birth are parents’ socioeconomic status (SES) and, recently, children's inherited DNA differences that can be aggregated in genome-wide polygenic scores (GPS). Here, we chart for the first time the developmental interplay between these two predictors of educational achievement at ages 7, 11, 14 and 16 in a sample of almost 5,000 UK school children. We show that the prediction of educational achievement from both GPS and SES increases steadily throughout the school years. Using latent growth curve models, we find that GPS and SES not only predict educational achievement in the first grade but they also account for systematic changes in achievement across the school years. At the end of compulsory education at age 16, GPS and SES, respectively, predict 14% and 23% of the variance of educational achievement. Analyses of the extremes of GPS and SES highlight their influence and interplay: In children who have high GPS and come from high SES families, 77% go to university, whereas 21% of children with low GPS and from low SES backgrounds attend university. We find that the associations of GPS and SES with educational achievement are primarily additive, suggesting that their joint influence is particularly dramatic for children at the extreme ends of the distribution

    Stellar Astrophysics with a Dispersed Fourier Transform Spectrograph. II. Orbits of Double-lined Spectroscopic Binaries

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    We present orbital parameters for six double-lined spectroscopic binaries (iota Pegasi, omega Draconis, 12 Bootis, V1143 Cygni, beta Aurigae, and Mizar A) and two double-lined triple star systems (kappa Pegasi and eta Virginis). The orbital fits are based upon high-precision radial velocity observations made with a dispersed Fourier Transform Spectrograph, or dFTS, a new instrument which combines interferometric and dispersive elements. For some of the double-lined binaries with known inclination angles, the quality of our RV data permits us to determine the masses M_1 and M_2 of the stellar components with relative errors as small as 0.2%.Comment: 41 pages, 8 figures, accepted by A

    Clinical Characteristics of Patients with Malignant Pleural Mesothelioma Harboring Somatic BAP1 Mutations

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    IntroductionGenomic studies of malignant pleural mesothelioma (MPM) have recently identified frequent mutations in the BRCA-associated protein 1(BAP1) gene. In uveal melanoma and clear cell renal cell carcinoma, BAP1 mutations are associated with poor outcomes but their clinical significance in MPM is unknown. We therefore undertook this study to define the characteristics of patients whose MPM tumors harbor somatic BAP1 mutation and to examine the relationship between BAP1 mutation and survival.MethodsWe reviewed the charts of 121 patients with MPM tumors diagnosed between 1991 and 2009 tested for BAP1 mutation, and extracted the following information: age at diagnosis, sex, histology, stage, smoking status, asbestos exposure, family or personal history of malignancy, and treatment including surgery, chemotherapy, and radiation as well as survival status.ResultsTwenty-four of the 121 tumors (20%) harbored somatic BAP1 mutations. The percentage of current or former smokers among cases with BAP1 mutations was significantly higher than in BAP1 wild-type cases, (75% versus 42%; p = 0.006). However, the types of nucleotide substitutions in BAP1 did not suggest that this association was because of a causative role of smoking in BAP1 mutations. No other clinical feature was significantly different among those with and without BAP1 mutations in their MPM. There was also no difference in survival according to somatic BAP1 mutation status.ConclusionThere is no apparent distinct clinical phenotype for MPM with somatic BAP1 mutation. The significance of the more frequent history of smoking among patients with BAP1-mutated MPM warrants further study
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