629 research outputs found

    BcB_c mesons in a Bethe-Salpeter model

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    We apply our Bethe-Salpeter model for mesons to the BcB_c family with parameters fixed in our previous investigation. We evaluate the mass of the pseudo-scalar BcB_c meson as 6.356 GeV/c2c^2 and 6.380 GeV/c2c^2 and the lifetime as 0.47 ps and 0.46 ps respectively in two reductions of the Bethe-Salpeter Equation, in good agreement with the recently reported mass of 6.40 ±\pm 0.39 (stat.) ±\pm 0.13 (syst.) GeV/c2c^2 and lifetime of 0.46−0.16+0.180.46^{+0.18}_{-0.16} (stat.) ±\pm 0.03 (syst.) ps by the CDF Collaboration. We evaluate the decay constant of the BcB_c meson and compare different contributions to its decay width.Comment: 9 page

    Solar Modulation of Inner Trapped Belt Radiation Flux as a Function of Atmospheric Density

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    No simple algorithm seems to exist for calculating proton fluxes and lifetimes in the Earth's inner, trapped radiation belt throughout the solar cycle. Most models of the inner trapped belt in use depend upon AP8 which only describes the radiation environment at solar maximum and solar minimum in Cycle 20. One exception is NOAAPRO which incorporates flight data from the TIROS/NOAA polar orbiting spacecraft. The present study discloses yet another, simple formulation for approximating proton fluxes at any time in a given solar cycle, in particular between solar maximum and solar minimum. It is derived from AP8 using a regression algorithm technique from nuclear physics. From flux and its time integral fluence, one can then approximate dose rate and its time integral dose

    Characterization of RAPD markers in Vitis

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    A study was initiated to investigate the possibility of using RAPD markers in related populations of Vitis. We also sought to design primers that could amplify translation initiation sites (Kozak sequence) as a mean to maximize the production of RAPD markers from single copy DNA sequences in the genome. RAPD bands were labeled and used as probes on blots with either genomic DNA or RAPD products from cvs Aurore, Cayuga White, Horizon and Illinois 547-1. Reamplification of excised RAPD products produced either several bands of smaller size, a single band of smaller size or a single band of the same size as the original band. Among 16 probes hybridized to genomic DNA blots, three probes, including one from the Kozak primer amplification, hybridized to 1-2 bands, 5 probes hybridized to 3-8 bands and 8, including two from a Kozak primer reaction, to more than 10 bands on the genomic DNA blots. Twelve RAPD bands were also probed on RAPD blots derived from the RAPD reaction that produced each probe. Three of those probes hybridized to 1-2 bands, 8 hybridized to 3-8 and one hybridized to more than 10 bands indicating the presence of probe sequences in more than one RAPD band as amplified with the same primers. This result and the observations on reamplification of RAPD bands support the hypothesis that some of the longer RAPD fragments harbor internal priming sites that are either not amplified unless the reaction mixture is saturated with longer other primers indicating amplification from the same sequence but different sized repetitive DNA. RAPD reactions were also run with 16 primers on parental DNA of 2 crosses used in genetic mapping (Cayuga White x Aurore and Horizon x Illinois 547-1). These reactions rated 140 bands; 100 bands were shared by both populations, including 47 polymorphic bands. Ten polymorphic bands in Cayuga White x Aurore and 22 in Horizon x Illinois 547-1 were population specific. The RAPD analysis as well as hybridization of RAPD markers to the genomic blots suggest that linkage analysis could be used in related segregating populations with carefully chosen markers. Tagging single copy regions with Kozak-sequence-derived primers may be possible, but the low number of probes tested and lack of DNA sequence information prevents any definite conclusions

    Serum Macromineral Levels in Estrual, Fertile, Subfertile and Pregnant Mares Kept Under Two Different Managemental Conditions

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    This study was conducted on 300 mares kept under one of the two managemental conditions: field (individual management) and farm (organizational management). Mares were categorized as estrual, fertile, subfertile or pregnant. Any possible relationship between fertility and serum levels of sodium, magnesium, phosphorus, potassium and calcium was investigated. The serum sodium level differed significantly (P<0.05) among all groups of mares at both conditions, with pregnant mares having the highest and subfertile the lowest levels. Also, independent of the condition, the pregnant mares had significantly higher (P<0.05) serum potassium levels compared with subfertile ones. Serum calcium levels were significantly higher in estrual mares when compared with those of pregnant mares under farm management or subfertile mares under field conditions. In each group, mares kept under farm management had significantly higher serum magnesium levels but significantly lower serum calcium levels than those of mares kept under field. In estrual group, mares raised under field condition had significantly higher serum phosphorus levels. These results sufficiently provide the foundation for more rigorous and controlled studies to establish a firm basis for fertility versus serum-mineral-profile relationship. Moreover, due to marginally adequate serum mineral levels in mares kept under both managements, supplementation with mineral mixture was recommended for optimum fertility

    Simplified Solar Modulation Model of Inner Trapped Belt Proton Flux As a Function of Atmospheric Density

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    No simple algorithm seems to exist for calculating proton fluxes and lifetimes in the Earth's inner, trapped radiation belt throughout the solar cycle. Most models of the inner trapped belt in use depend upon AP8 which only describes the radiation environment at solar maximum and solar minimum in Cycle 20. One exception is NOAAPRO which incorporates flight data from the TIROS/NOAA polar orbiting spacecraft. The present study discloses yet another, simple formulation for approximating proton fluxes at any time in a given solar cycle, in particular between solar maximum and solar minimum. It is derived from AP8 using a regression algorithm technique from nuclear physics. From flux and its time integral fluence, one can then approximate dose rate and its time integral dose. It has already been published in this journal that the absorbed dose rate, D, in the trapped belts exhibits a power law relationship, D = A(rho)(sup -n), where A is a constant, rho is the atmospheric density, and the index n is weakly dependent upon shielding. However, that method does not work for flux and fluence. Instead, we extend this idea by showing that the power law approximation for flux J is actually bivariant in energy E as well as density rho. The resulting relation is J(E,rho)approx.(sum of)A(E(sup n))rho(sup -n), with A itself a power law in E. This provides another method for calculating approximate proton flux and lifetime at any time in the solar cycle. These in turn can be used to predict the associated dose and dose rate

    Evolving rules for document classification

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    We describe a novel method for using Genetic Programming to create compact classification rules based on combinations of N-Grams (character strings). Genetic programs acquire fitness by producing rules that are effective classifiers in terms of precision and recall when evaluated against a set of training documents. We describe a set of functions and terminals and provide results from a classification task using the Reuters 21578 dataset. We also suggest that because the induced rules are meaningful to a human analyst they may have a number of other uses beyond classification and provide a basis for text mining applications

    EPIDEMIOLOGICAL SURVEY OF GENITAL PROLAPSE IN BUFFALOES KEPT UNDER DIFFERENT SYSTEMS AND SERUM MICRO MINERAL CONTENTS

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    The present project was planned to conduct an epidemiological survey of genital prolapse in buffaloes kept under different feeding and production systems and to study serum micro mineral contents in these animals. Data on 343 buffaloes were recorded for epidemiological studies, including 297 normal pregnant and 46 prolapsed cases. For serum micro mineral contents, blood samples were collected from 40 buffaloes comprising of 20 normal pregnant and 20 suffering from genital prolapse and analyzed for serum Cu, Zn, Fe and Mn contents. Occurrence of genital prolapse differed non significantly in animals kept under two feeding systems (stall fed and semi stall fed), three floor conditions (uneven floor, kacha/brick floor, sloppy floor) and two production systems (rural subsistence small holding and market oriented small holding). Its occurrence was higher during humid summer than other seasons. The mean values of serum copper and zinc were lower in prolapsed buffaloes compared to controls (P<0.01), while there was no difference in serum iron and manganese concentrations among animals of the two groups. Parity had no effect on serum concentration of any micro mineral. However, serum Zn level was higher in buffaloes suffering from vaginal prolapse compared to those with uterine prolapse (P<0.05)
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