121 research outputs found

    Evaluation of PRNP Expression Based on Genotypes and Alleles of Two Indel Loci in the Medulla Oblongata of Japanese Black and Japanese Brown Cattle

    Get PDF
    BACKGROUND: Prion protein (PrP) level plays the central role in bovine spongiform encephalopathy (BSE) susceptibility. Increasing the level of PrP decreases incubation period for this disease. Therefore, studying the expression of the cellular PrP or at least the messenger RNA might be used in selection for preventing the propagation of BSE and other prion diseases. Two insertion/deletion (indel) variations have been tentatively associated with susceptibility/resistance of cattle to classical BSE. METHODOLOGY/PRINCIPAL FINDINGS: We studied the expression of each genotype at the two indel sites in Japanese Black (JB) and Japanese Brown (JBr) cattle breeds by a standard curve method of real-time PCR. Five diplotypes subdivided into two categories were selected from each breed. The two cattle breeds were considered differently. Expression of PRNP was significantly (p<0.0001) greater in the homozygous deletion genotype at the 23-bp locus in JB breed. Compared to the homozygous genotypes, the expression of PRNP was significantly greater in the heterozygous genotype at the 12-bp locus in JB (p<0.0001) and in JBr (p = 0.0394) breeds. In addition, there was a statistical significance in the PRNP levels between the insertion and the deletion alleles of the 23-bp locus in JB (p = 0.0003) as well as in JBr (p = 0.0032). There was no significance in relation to sex, age, geographical location or due to their interactions (p>0.05). CONCLUSION: Our results suggest that the del/del genotype or at least its del allele may modulate the expression of PRNP at the 23-bp locus in the medulla oblongata of these cattle breeds

    Measurement of the diffractive structure function in deep inelastic scattering at HERA

    Full text link
    This paper presents an analysis of the inclusive properties of diffractive deep inelastic scattering events produced in epep interactions at HERA. The events are characterised by a rapidity gap between the outgoing proton system and the remaining hadronic system. Inclusive distributions are presented and compared with Monte Carlo models for diffractive processes. The data are consistent with models where the pomeron structure function has a hard and a soft contribution. The diffractive structure function is measured as a function of \xpom, the momentum fraction lost by the proton, of β\beta, the momentum fraction of the struck quark with respect to \xpom, and of Q2Q^2. The \xpom dependence is consistent with the form \xpoma where a = 1.30 ± 0.08 (stat)  0.14+ 0.08 (sys)a~=~1.30~\pm~0.08~(stat)~^{+~0.08}_{-~0.14}~(sys) in all bins of β\beta and Q2Q^2. In the measured Q2Q^2 range, the diffractive structure function approximately scales with Q2Q^2 at fixed β\beta. In an Ingelman-Schlein type model, where commonly used pomeron flux factor normalisations are assumed, it is found that the quarks within the pomeron do not saturate the momentum sum rule.Comment: 36 pages, latex, 11 figures appended as uuencoded fil

    Observation of hard scattering in photoproduction events with a large rapidity gap at HERA

    Get PDF
    Events with a large rapidity gap and total transverse energy greater than 5 GeV have been observed in quasi-real photoproduction at HERA with the ZEUS detector. The distribution of these events as a function of the γp\gamma p centre of mass energy is consistent with diffractive scattering. For total transverse energies above 12 GeV, the hadronic final states show predominantly a two-jet structure with each jet having a transverse energy greater than 4 GeV. For the two-jet events, little energy flow is found outside the jets. This observation is consistent with the hard scattering of a quasi-real photon with a colourless object in the proton.Comment: 19 pages, latex, 4 figures appended as uuencoded fil

    Measurement of Charged and Neutral Current e-p Deep Inelastic Scattering Cross Sections at High Q2

    Get PDF
    Deep inelastic e-p scattering has been studied in both the charged current (CC) and neutral current (NC) reactions at momentum transfers squared Q(2) above 400 GeV2 using the ZEUS detector at the HERA ep collider. The CC and NC total cross sections, the NC to CC cross section ratio, and the differential cross sections d sigma/dQ(2) are presented. From the Q(2) dependence of the CC cross section, the mass term in the CC propagator is determined to be M(W) = 76 +/- 16 +/- 13 GeV

    Extraction of the gluon density of the proton at x

    Full text link
    corecore