204 research outputs found

    Λc+\Lambda^+_c- and Λb\Lambda_b-hypernuclei

    Full text link
    Λc+\Lambda^+_c- and Λb\Lambda_b-hypernuclei are studied in the quark-meson coupling (QMC) model. Comparisons are made with the results for Λ\Lambda-hypernuclei studied in the same model previously. Although the scalar and vector potentials felt by the Λ\Lambda, Λc+\Lambda_c^+ and Λb\Lambda_b in the corresponding hypernuclei multiplet which has the same baryon numbers are quite similar, the wave functions obtained, e.g., for 1s1/21s_{1/2} state, are very different. The Λc+\Lambda^+_c baryon density distribution in Λc+209^{209}_{\Lambda^+_c}Pb is much more pushed away from the center than that for the Λ\Lambda in Λ209^{209}_\LambdaPb due to the Coulomb force. On the contrary, the Λb\Lambda_b baryon density distributions in Λb\Lambda_b-hypernuclei are much larger near the origin than those for the Λ\Lambda in the corresponding Λ\Lambda-hypernuclei due to its heavy mass. It is also found that level spacing for the Λb\Lambda_b single-particle energies is much smaller than that for the Λ\Lambda and Λc+\Lambda^+_c.Comment: Latex, 14 pages, 4 figures, text was extended, version to appear in Phys. Rev.

    Galaxy infall kinematics as a test of modified gravity

    Get PDF
    Infrared modifications of General Relativity (GR) can be revealed by comparing the mass of galaxy clusters estimated from weak lensing to that from infall kinematics. We measure the 2D galaxy velocity distribution in the cluster infall region by applying the galaxy infall kinematics (GIK) model developed by Zu and Weinberg (2013) to two suites of f(R) and Galileon modified gravity simulations. Despite having distinct screening mechanisms, namely, the Chameleon and the Vainshtein effects, the f(R) and Galileon clusters exhibit very similar deviations in their GIK profiles from GR, with ~ 100-200 k/s enhancement in the characteristic infall velocity at r=5 Mpc/h and 50-100 km/s broadening in the radial and tangential velocity dispersions across the entire infall region, for clusters with mass ~ 10^{14} Msol/h at z=0.25. These deviations are detectable via the GIK reconstruction of the redshift--space cluster-galaxy cross-correlation function, xi_cg^s(r_p,r_\pi), which shows ~ 1-2 Mpc/h increase in the characteristic line-of-sight distance r_\pi^c at r_p<6 Mpc/h from GR predictions. With overlapping deep imaging and large redshift surveys in the future, we expect that the GIK modelling of xi_cg^s, in combination with the stacked weak lensing measurements, will provide powerful diagnostics of modified gravity theories and the origin of cosmic acceleration

    Relationship of Circulating Ghrelin and Leptin Concentrations in Beef Cattle ExhibitingDifferences in Composition of Gain

    Get PDF
    Beef steers (n = 72) of similar age, weight (651 ± 3.1 lb), and genetic background (Angus crossbred) were used to determine the effects of growing period diet on the relationship of plasma ghrelin and leptin concentrations with growth performance and carcass composition. At trial initiation (d 0), 8 steers were harvested for initial carcass composition. The remaining 64 steers were allotted, by weight, to pen and treatment was assigned randomly. Treatments were 1) a high‐forage diet fed during the growing period (0‐116 d) followed by a high‐concentrate diet during the finishing period (117‐209 d; GRW‐FNSH) or 2) a high‐concentrate diet fed for the duration of the trial (0‐209 d; FNSH‐FNSH). Steers were allowed ad libitum consumption regardless of dietary treatment. Eight steers per treatment (1 pen) were harvested on d 88, 116, 165, and 209. At each harvest date, 9‐10‐11th rib sections were dissected for chemical composition, and carcass characteristics were recorded. Replicate blood samples were collected from every steer prior to each harvest, and assayed for ghrelin, leptin, GH, insulin, and NEFA concentrations. Hormone, growth performance, and carcass composition were analyzed statistically using the GLM procedure of SAS to evaluate diet, harvest date, and their interaction. Linear, quadratic, and cubic contrasts were performed. Percent carcass protein decreased linearly (P \u3c 0.001) and percent carcass fat increased linearly (P \u3c 0.001) in both treatments. At each harvest day, FNSH‐FNSH steers had greater carcass fat (P \u3c 0.01) compared with GRW‐FNSH steers. Plasma ghrelin concentrations for FNSH‐FNSH increased quadraticly (P \u3c 0.001) over time, whereas plasma ghrelin concentrations were not different over time for GRW‐FNSH. Plasma leptin concentrations for FNSH‐FNSH increased (P \u3c 0.001) from d 0 to 88 and then plateaued, whereas plasma leptin concentrations increased linearly (P \u3c 0.001) for the GRW‐FNSH. Plasma ghrelin and leptin concentrations fluctuated relative to nutritional status, and plasma ghrelin concentrations were highest in excessively fat cattle. The role of ghrelin during fat accumulation warrants further investigation

    A surveillance of enteropathogens in piglets from birth to seven days of age in Brazil

    Full text link
    The purpose of the study was to evaluate the real importance of anaerobic enteropathogens and rotavirus in contrast to more common agents as cause of diarrhea in piglets within the first week of life. Sixty 1- to 7-day-old piglets, 30 diarrheic and 30 non-diarrheic (control), from 15 different herds were selected, euthanized and necropsied. Samples of the jejunum, ileum, colon, cecum and feces were collected from the piglets and analyzed to determine the presence of the following enteropathogens: enterotoxigenic Escherichia coli (ETEC), Clostridium perfringens types A and C, Clostridium difficile, rotavirus and Isospora suis. Among diarrheic piglets, 23.3% were positive for C. difficile, 70% for C. perfringens type A cpb2+, 14.3% for rotavirus and 10% for ETEC. Among non-diarrheic control piglets, 10% were positive for C. difficile, 76.7% for C. perfringens type A cpb2+, 0% for rotavirus, 3.3% for ETEC and 3.3% for I. suis. C. perfringens type C was not detected in any of the animals. Histological lesions characteristic of C. difficile, E. coli and rotavirus were observed. However, no C. perfringens type A suggestive lesions were detected. There was a positive correlation between mesocolon edema and the presence of C. difficile toxins. Although C. perfringens type A cpb2+ was the most frequently detected enteropathogen, there was no association between its presence and diarrhea or macro or microscopic changes. C. difficile and Rotavirus were the most relevant pathogens involved with neonatal diarrhea in this study, and histopathology associated with microbiological test proved to be the key to reach a final diagnosis

    Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

    Get PDF
    The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages
    corecore