MONITORAMENTO OVARIANO AO ABATE DE LEITOAS DESCARTADAS POR ANESTRO OU ESTRO ATÍPICO

Granjas , manejadas dentro de intenso fluxo de produção, trabalham com taxas anuais de descarte relativamente elevadas (35-50%). Muitas fêmeas são descartadas por problemas irreais. Esses podem ser oriundos de falhas humanas durante sua determinação, levando a um aumento na taxa de renovação do plantel, diminuição da produtividade e, conseqüentemente, aumento dos dias não produtivos e elevados custos. O objetivo do presente trabalho foi realizar uma análise observacional dos ovários de leitoas descartadas por anestro ou estro atípico. O experimento foi realizado em dois frigoríficos de abate de suínos, onde foram avaliados macroscopicamente os ovários de 145 leitoas descartadas por anestro ou estro atípico. Os ovários foram classificados em lisos ou com folículos; com corpos lúteos, e com corpos albicans e corpos lúteos. Das 83 leitoas descartadas por anestro, 13% apresentaram ovários lisos ou com folículos, indicando que essas não haviam ciclado na granja. Por outro lado, 83% das fêmeas apresentaram ovários com corpos lúteos e/ou corpos albicans, indicando que já haviam ciclado na granja. Algumas fêmeas (4%) apresentaram ovários policísticos. Das 62 fêmeas descartadas por estro atípico na granja, 2, 24% não haviam ciclado na granja e 76% haviam ciclado, segundo a avaliação de seus ovários. Os resultados mostram que o acompanhamento ao abate, de fêmeas descartadas por falhas reprodutivas, permite verificar se as razões do descarte condizem ou não com o status fisiológico do trato reprodutivo. Ovarian monitorament at slaughter of gilts culled by anoestrus or atypic oestrus Abstract Intensively managed pig farms work with relatively high annual culling rate, between 35-50%. Many females are culled by causes unrelated to the suspected diagnosis. The problems can arise from human failure, leading to an increased herd replacement rate, decrease on productivity and consequent increase in non-productive days and raised costs. The objective of the present work was to perform an observational analysis of the ovaries of gilts culled by anoestrus or atypical oestrus. The experiment was carried out in two swine slaughterhouses where 145 ovaries of gilts, culled by anoestrus or atypical oestrus, were macroscopically evaluated. The ovaries were classified in: inactive or with follicles; with corpora lutea; and with corpora albicantia and corpora lutea. From 83 gilts culled by anoestrus, 13% presented inactive ovaries or with follicles, indicating that they had not cycled on the farm. On the other hand, 83% presented ovaries with corpora lutea and/or corpora albicantia, indicating that they had previously cycled. Some gilts (4%) presented policystic ovaries. From 62 females culled by atypical oestrus on farm 2, 24% did not cycle on the farm and 76% cycled, according to the ovary examination. The results show that a slaughter examination of gilts culled by reproductive causes, allow to assess if culling reasons correspond to the physiological status of the reproductive tract

Low Q^2 Jet Production at HERA and Virtual Photon Structure

The transition between photoproduction and deep-inelastic scattering is investigated in jet production at the HERA ep collider, using data collected by the H1 experiment. Measurements of the differential inclusive jet cross-sections dsigep/dEt* and dsigmep/deta*, where Et* and eta* are the transverse energy and the pseudorapidity of the jets in the virtual photon-proton centre of mass frame, are presented for 0 < Q2 < 49 GeV2 and 0.3 < y < 0.6. The interpretation of the results in terms of the structure of the virtual photon is discussed. The data are best described by QCD calculations which include a partonic structure of the virtual photon that evolves with Q2.Comment: 20 pages, 5 Figure

Hadron Production in Diffractive Deep-Inelastic Scattering

Characteristics of hadron production in diffractive deep-inelastic positron-proton scattering are studied using data collected in 1994 by the H1 experiment at HERA. The following distributions are measured in the centre-of-mass frame of the photon dissociation system: the hadronic energy flow, the Feynman-x (x_F) variable for charged particles, the squared transverse momentum of charged particles (p_T^{*2}), and the mean p_T^{*2} as a function of x_F. These distributions are compared with results in the gamma^* p centre-of-mass frame from inclusive deep-inelastic scattering in the fixed-target experiment EMC, and also with the predictions of several Monte Carlo calculations. The data are consistent with a picture in which the partonic structure of the diffractive exchange is dominated at low Q^2 by hard gluons.Comment: 16 pages, 6 figures, submitted to Phys. Lett.

Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA

An investigation of the hadronic final state in diffractive and non--diffractive deep--inelastic electron--proton scattering at HERA is presented, where diffractive data are selected experimentally by demanding a large gap in pseudo --rapidity around the proton remnant direction. The transverse energy flow in the hadronic final state is evaluated using a set of estimators which quantify topological properties. Using available Monte Carlo QCD calculations, it is demonstrated that the final state in diffractive DIS exhibits the features expected if the interaction is interpreted as the scattering of an electron off a current quark with associated effects of perturbative QCD. A model in which deep--inelastic diffraction is taken to be the exchange of a pomeron with partonic structure is found to reproduce the measurements well. Models for deep--inelastic $ep$ scattering, in which a sizeable diffractive contribution is present because of non--perturbative effects in the production of the hadronic final state, reproduce the general tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil

A Search for Selectrons and Squarks at HERA

Data from electron-proton collisions at a center-of-mass energy of 300 GeV are used for a search for selectrons and squarks within the framework of the minimal supersymmetric model. The decays of selectrons and squarks into the lightest supersymmetric particle lead to final states with an electron and hadrons accompanied by large missing energy and transverse momentum. No signal is found and new bounds on the existence of these particles are derived. At 95% confidence level the excluded region extends to 65 GeV for selectron and squark masses, and to 40 GeV for the mass of the lightest supersymmetric particle.Comment: 13 pages, latex, 6 Figure

Measurement of D* Meson Cross Sections at HERA and Determination of the Gluon Density in the Proton using NLO QCD

With the H1 detector at the ep collider HERA, D* meson production cross sections have been measured in deep inelastic scattering with four-momentum transfers Q^2>2 GeV2 and in photoproduction at energies around W(gamma p)~ 88 GeV and 194 GeV. Next-to-Leading Order QCD calculations are found to describe the differential cross sections within theoretical and experimental uncertainties. Using these calculations, the NLO gluon momentum distribution in the proton, x_g g(x_g), has been extracted in the momentum fraction range 7.5x10^{-4}< x_g <4x10^{-2} at average scales mu^2 =25 to 50 GeV2. The gluon momentum fraction x_g has been obtained from the measured kinematics of the scattered electron and the D* meson in the final state. The results compare well with the gluon distribution obtained from the analysis of scaling violations of the proton structure function F_2.Comment: 27 pages, 9 figures, 2 tables, submitted to Nucl. Phys.

Measurement of Leading Proton and Neutron Production in Deep Inelastic Scattering at HERA

Deep--inelastic scattering events with a leading baryon have been detected by the H1 experiment at HERA using a forward proton spectrometer and a forward neutron calorimeter. Semi--inclusive cross sections have been measured in the kinematic region 2 <= Q^2 <= 50 GeV^2, 6.10^-5 <= x <= 6.10^-3 and baryon p_T <= MeV, for events with a final state proton with energy 580 <= E' <= 740 GeV, or a neutron with energy E' >= 160 GeV. The measurements are used to test production models and factorization hypotheses. A Regge model of leading baryon production which consists of pion, pomeron and secondary reggeon exchanges gives an acceptable description of both semi-inclusive cross sections in the region 0.7 <= E'/E_p <= 0.9, where E_p is the proton beam energy. The leading neutron data are used to estimate for the first time the structure function of the pion at small Bjorken--x.Comment: 30 pages, 9 figures, 2 tables, submitted to Eur. Phys.

Search for heavy neutral lepton production in K+ decays to positrons

A search for heavy neutral lepton (N) production in K+→e+N decays using the data sample collected by the NA62 experiment at CERN in 2017-2018 is reported. Upper limits of the extended neutrino mixing matrix element |Ue4|^2 are established at the level of 10^−9 over most of the accessible heavy neutral lepton mass range 144-462 MeV/c^2, with the assumption that the lifetime exceeds 50 ns. These limits improve significantly upon those of previous production and decay searches. The |Ue4|^2 range favoured by Big Bang Nucleosynthesis is excluded up to a mass of about 340 MeV/c^2