51 research outputs found
A Preliminary Assessment of Lung lesion Distribution in Fed Cattle
The objectives of this research were to describe the lobar location of lung lesions and determine diagnostic sensitivity of lung lesion detection when only a portion of lobes are evaluated
A Retrospective Case Study Implicating Foster Calves in a Calf Diarrhea Epidemic
This report is a retrospective case study of a herd that experienced a severe calf scours epidemic in 2000. The objective of this study was to determine risk factors at work in this epidemic
Corn Germ as a Source of Supplemental Fat for Cows in late Gestation
To evaluate corn germ as a source of supplemental fat, 217 two to twelve-year-old cows receiving grass hay free choice were supplemented with either 2.75 lb of corn germ (dry basis) or an equal amount of crude protein from soybean meal (0.80 lb dry matter) starting approximately 50 days prior to the first expected calving. Cows were removed from treatment the day they calved and where managed as a group through the breeding season. Supplement treatment did not affect cow weight change or body condition score. Corn germ did not improve any measure of reproduction, including the percentage of cows cycling or conceiving in the first 21 days of the breeding season or the days from calving to the onset of cyclicity or conception. Calf performance, calf health or indicators of colostrum absorption (total serum protein or IgG) were not influenced by supplement treatment. The results were similar whether all age groups were included in the analysis or when only data for the two and three year old cows were included in the data set. Under the conditions of this study there was no advantage to feeding a source of supplemental fat from corn germ during late gestation
Assessment of Diversity of Antimicrobial Resistance Phenotypes and Genotypes of \u3ci\u3eMannheimia haemolytica\u3c/i\u3e Isolates from Bovine Nasopharyngeal Swabs
The threat of bovine respiratory disease (BRD) for cattle operations is exacerbated by increasing prevalence of antimicrobial resistance (AMR) in Mannheimia haemolytica, a leading cause of BRD. Characterization of AMR in M. haemolytica by culture and susceptibility testing is complicated by uncertainty regarding the number of colonies that must be selected to accurately characterize AMR phenotypes (antibiograms) and genotypes in a culture. The study objective was to assess phenotypic and genotypic diversity of M. haemolytica isolates on nasopharyngeal swabs (NPS) from 28 cattle at risk for BRD or with BRD. NPS were swabbed onto five consecutive blood agar plates; after incubation up to 20 M. haemolytica colonies were selected per plate (up to 100 colonies per NPS). Phenotype was determined by measuring minimum inhibitory concentrations (MIC) for 11 antimicrobials and classifying isolates as resistant or not. Genotype was indirectly determined by matrix-assisted laser desorption/ionization time of flight mass spectroscopy (MALDI-TOF MS). NPS from 11 of 28 cattle yielded at least one M. haemolytica isolate; median (range) of isolates per NPS was 48 (1–94). NPS from seven cattle yielded one phenotype, 3 NPS yielded two, and 1 NPS yielded three; however, within a sample all phenotypic differences were due to only oneMIC dilution. On each NPS all M. haemolytica isolated were the same genotype; genotype 1 was isolated from three NPS and genotype two was isolated from eight. Diversity of M. haemolytica on bovine NPS was limited, suggesting that selection of few colonies might adequately identify relevant phenotypes and genotypes
Measurement of inclusive D*+- and associated dijet cross sections in photoproduction at HERA
Inclusive photoproduction of D*+- mesons has been measured for photon-proton
centre-of-mass energies in the range 130 < W < 280 GeV and a photon virtuality
Q^2 < 1 GeV^2. The data sample used corresponds to an integrated luminosity of
37 pb^-1. Total and differential cross sections as functions of the D*
transverse momentum and pseudorapidity are presented in restricted kinematical
regions and the data are compared with next-to-leading order (NLO) perturbative
QCD calculations using the "massive charm" and "massless charm" schemes. The
measured cross sections are generally above the NLO calculations, in particular
in the forward (proton) direction. The large data sample also allows the study
of dijet production associated with charm. A significant resolved as well as a
direct photon component contribute to the cross section. Leading order QCD
Monte Carlo calculations indicate that the resolved contribution arises from a
significant charm component in the photon. A massive charm NLO parton level
calculation yields lower cross sections compared to the measured results in a
kinematic region where the resolved photon contribution is significant.Comment: 32 pages including 6 figure
Measurement of Jet Shapes in Photoproduction at HERA
The shape of jets produced in quasi-real photon-proton collisions at
centre-of-mass energies in the range GeV has been measured using the
hadronic energy flow. The measurement was done with the ZEUS detector at HERA.
Jets are identified using a cone algorithm in the plane with a
cone radius of one unit. Measured jet shapes both in inclusive jet and dijet
production with transverse energies GeV are presented. The jet
shape broadens as the jet pseudorapidity () increases and narrows
as increases. In dijet photoproduction, the jet shapes have been
measured separately for samples dominated by resolved and by direct processes.
Leading-logarithm parton-shower Monte Carlo calculations of resolved and direct
processes describe well the measured jet shapes except for the inclusive
production of jets with high and low . The observed
broadening of the jet shape as increases is consistent with the
predicted increase in the fraction of final state gluon jets.Comment: 29 pages including 9 figure
Measurement of the Diffractive Cross Section in Deep Inelastic Scattering using ZEUS 1994 Data
The DIS diffractive cross section, , has been measured in the mass range GeV for c.m. energies GeV and photon virtualities to 140 GeV. For fixed and , the diffractive cross section rises rapidly with , with corresponding to a -averaged pomeron trajectory of \bar{\alphapom} = 1.127 \pm 0.009 (stat)^{+0.039}_{-0.012} (syst) which is larger than \bar{\alphapom} observed in hadron-hadron scattering. The dependence of the diffractive cross section is found to be the same as that of the total cross section for scattering of virtual photons on protons. The data are consistent with the assumption that the diffractive structure function factorizes according to \xpom F^{D(3)}_2 (\xpom,\beta,Q^2) = (x_0/ \xpom)^n F^{D(2)}_2(\beta,Q^2). They are also consistent with QCD based models which incorporate factorization breaking. The rise of \xpom F^{D(3)}_2 with decreasing \xpom and the weak dependence of on suggest a substantial contribution from partonic interactions
Exclusive Electroproduction of and Mesons at HERA
Exclusive production of and mesons in e^+ p collisions has
been studied with the ZEUS detector in the kinematic range for the data and for the data. Cross sections for exclusive and
production have been measured as a function of and . The
spin-density matrix elements and have
been determined for exclusive production as well as and
for exclusive production.
The results are discussed in the context of theoretical models invoking soft
and hard phenomena.Comment: 57 pages including 21 figures, minor modifications to Figs. 19-21,
these figures supercede those of Eur. Phys. J. C6 (1999) 603-62
Application of Functional Genomics for Bovine Respiratory Disease Diagnostics
Bovine respiratory disease (BRD) is the most common economically important disease affecting cattle. For developing accurate diagnostics that can predict disease susceptibility/resistance and stratification, it is necessary to identify the molecular mechanisms that underlie BRD. To study the complex interactions among the bovine host and the multitude of viral and bacterial pathogens, as well as the environmental factors associated with BRD etiology, genome-scale high-throughput functional genomics methods such as microarrays, RNA-seq, and proteomics are helpful. In this review, we summarize the progress made in our understanding of BRD using functional genomics approaches. We also discuss some of the available bioinformatics resources for analyzing high-throughput data, in the context of biological pathways and molecular interactions. Although resources for studying host response to infection are available, the corresponding information is lacking for majority of BRD pathogens, impeding progress in identifying diagnostic signatures for BRD using functional genomics approaches
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