VARICELLA-RELATED HOSPITALIZATIONS IN CHILDREN – CASE SERIES IN A SECONDARY HOSPITAL

Introdução: A varicela é uma doença infeciosa frequente na infância. Embora considerada geralmente uma doença benigna e autolimitada, pode cursar com complicações graves. O objetivo deste trabalho foi caracterizar os internamentos por varicela e suas complicações. Métodos: Análise retrospetiva dos processos clínicos das crianças com internamento no Serviço de Pediatria por varicela entre 01.01.2000 e 31.12.2012. Resultados: Foram internadas 105 crianças por varicela, nos 13 anos avaliados, com idades entre um dia e os dez anos (mediana: 22 meses), sendo 51,4% do género feminino. A maior incidência sazonal foi de Abril a Junho. Nenhuma criança tinha a vacina antivírus varicela-zoster. Complicações associadas à varicela foram o motivo de internamento mais frequente (76%), incluindo infeções cutâneas (56,8%), complicações respiratórias (14,8%) e neurológicas (14,8%). As restantes crianças foram internadas, pela presença de fatores de risco (idade, varicela congénita, imunossupressão) ou pela gravidade da sintomatologia. Efetuaram aciclovir 68 crianças (65%), das quais, 20 tinham iniciado terapêutica antes da hospitalização. A duração média do internamento foi de 4,5 dias. Foram transferidas três crianças para hospital terciário, uma por síndrome de pele escaldada, uma por otomastoidite com indicação cirúrgica e outra por pneumonia com derrame pleural. Uma criança com encefalite desenvolveu sequelas. Discussão: A varicela pode originar complicações graves sobretudo em crianças com fatores de risco. No período referido foi responsável por 0,7% dos internamentos. As complicações mais frequentes foram as cutâneas, o que está de acordo com outros estudos. Este trabalho permitiu rever as práticas do serviço, nomeadamente questionar critérios de internamento no grupo com fatores de risco, mas sem complicações da doença

Inibição de crescimento de plantas espontâneas por leguminosas herbáceas perenes na Caatinga Mineira - primeiro ano.

Publicado também na: Revista Brasileira de Agroecologia, v. 6. n. 2, dez. 2011

Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering

A semi-inclusive measurement of charged hadron multiplicities in deep inelastic muon scattering off an isoscalar target was performed using data collected by the COMPASS Collaboration at CERN. The following kinematic domain is covered by the data: photon virtuality Q2>1  (GeV/c)2, invariant mass of the hadronic system W>5  GeV/c2, Bjorken scaling variable in the range 0.003<x<0.4, fraction of the virtual photon energy carried by the hadron in the range 0.2<z<0.8, and square of the hadron transverse momentum with respect to the virtual photon direction in the range 0.02  (GeV/c)2<PhT2<3  (GeV/c)2. The multiplicities are presented as a function of PhT2 in three-dimensional bins of x, Q2, z and compared to previous semi-inclusive measurements. We explore the small-PhT2 region, i.e. PhT2<1  (GeV/c)2, where hadron transverse momenta are expected to arise from nonperturbative effects, and also the domain of larger PhT2, where contributions from higher-order perturbative QCD are expected to dominate. The multiplicities are fitted using a single-exponential function at small PhT2 to study the dependence of the average transverse momentum ⟨PhT2⟩ on x, Q2 and z. The power-law behavior of the multiplicities at large PhT2 is investigated using various functional forms. The fits describe the data reasonably well over the full measured range.Peer Reviewe

Measurement of azimuthal hadron asymmetries in semi-inclusive deep inelastic scattering off unpolarised nucleons

Spin-averaged asymmetries in the azimuthal distributions of positive and negative hadrons produced in deep inelastic scattering were measured using the CERN SPS longitudinally polarised muon beam at 160 GeV/c and a 6 LiD target. The amplitudes of the three azimuthal modulations cos⁡ϕh , cos⁡2ϕh and sin⁡ϕh were obtained binning the data separately in each of the relevant kinematic variables x , z or pTh and binning in a three-dimensional grid of these three variables. The amplitudes of the cos⁡ϕh and cos⁡2ϕh modulations show strong kinematic dependencies both for positive and negative hadrons.Peer Reviewe

Experimental investigation of transverse spin asymmetries in muon-p SIDIS processes: Collins asymmetries

The COMPASS Collaboration at CERN has measured the transverse spin azimuthal asymmetry of charged hadrons produced in semi-inclusive deep inelastic scattering using a 160 GeV positive muon beam and a transversely polarised NH_3 target. The Collins asymmetry of the proton was extracted in the Bjorken x range 0.003<x<0.7. These new measurements confirm with higher accuracy previous measurements from the COMPASS and HERMES collaborations, which exhibit a definite effect in the valence quark region. The asymmetries for negative and positive hadrons are similar in magnitude and opposite in sign. They are compatible with model calculations in which the u-quark transversity is opposite in sign and somewhat larger than the d-quark transversity distribution function. The asymmetry is extracted as a function of Bjorken $x$, the relative hadron energy $z$ and the hadron transverse momentum p_T^h. The high statistics and quality of the data also allow for more detailed investigations of the dependence on the kinematic variables. These studies confirm the leading-twist nature of the Collins asymmetry.Peer Reviewe

Measurement of the charged-pion polarizability

The COMPASS collaboration at CERN has investigated pion Compton scattering, π-γ→π-γ, at center-of-mass energy below 3.5 pion masses. The process is embedded in the reaction π-Ni→π-γNi, which is initiated by 190 GeV pions impinging on a nickel target. The exchange of quasireal photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, Q2&lt;0.0015  (GeV/c)2. From a sample of 63 000 events, the pion electric polarizability is determined to be απ=(2.0±0.6stat±0.7syst)×10-4  fm3 under the assumption απ=-βπ, which relates the electric and magnetic dipole polarizabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is found in agreement with the expectation from chiral perturbation theory. An additional measurement replacing pions by muons, for which the cross-section behavior is unambiguously known, was performed for an independent estimate of the systematic uncertainty.Peer Reviewe

Interplay among transversity induced asymmetries in hadron leptoproduction

In the fragmentation of a transversely polarized quark several left-right asymmetries are possible for the hadrons in the jet. When only one unpolarized hadron is selected, it exhibits an azimuthal modulation known as Collins effect. When a pair of oppositely charged hadrons is observed, three asymmetries can be considered, a di-hadron asymmetry and two single hadron asymmetries. In lepton deep inelastic scattering on transversely polarized nucleons all these asymmetries are coupled with the transversity distribution. From the high statistics COMPASS data on oppositely charged hadron-pair production we have investigated for the first time the dependence of these three asymmetries on the difference of the azimuthal angles of the two hadrons. The similarity of transversity induced single and di-hadron asymmetries is discussed. A new analysis of the data allows to establish quantitative relationships among them, providing for the first time strong experimental indication that the underlying fragmentation mechanisms are all driven by a common physical process.Peer Reviewe

K−^− over K+^+ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy

The K$^{-}$ over K$^{+}$ multiplicity ratio is measured in deep-inelastic scattering, for the first time for kaons carrying a large fraction $z$ of the virtual-photon energy. The data were obtained by the COMPASS collaboration using a 160 GeV muon beam and an isoscalar $^6$LiD target. The regime of deep-inelastic scattering is ensured by requiring $Q^2>1$ (GeV/$c)^2$ for the photon virtuality and $W>5$ GeV/$c^2$ for the invariant mass of the produced hadronic system. Kaons are identified in the momentum range from 12 GeV/$c$ to 40 GeV/$c$, thereby restricting the range in Bjorken-$x$ to $0.010.75$. For very large values of $z$, $i.e.$ $z>0.8$, the results contradict expectations obtained using the formalism of (next-to-)leading order perturbative quantum chromodynamics. This may imply that cross-section factorisation or/and universality of (kaon) fragmentation functions do not hold. Our studies suggest that within this formalism an additional correction may be required, which takes into account the phase space available for hadronisation.Peer Reviewe

First measurement of transverse-spin-dependent azimuthal asymmetries in the Drell-Yan process

The first measurement of transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan (DY) process is reported. We use the CERN SPS 190  GeV/c π- beam and a transversely polarized ammonia target. Three azimuthal asymmetries giving access to different transverse-momentum-dependent (TMD) parton distribution functions (PDFs) are extracted using dimuon events with invariant mass between 4.3  GeV/c2 and 8.5  GeV/c2. Within the experimental uncertainties, the observed sign of the Sivers asymmetry is found to be consistent with the fundamental prediction of quantum chromodynamics (QCD) that the Sivers TMD PDFs extracted from DY have a sign opposite to the one extracted from semi-inclusive deep-inelastic scattering (SIDIS) data. We present two other asymmetries originating from the pion Boer-Mulders TMD PDFs convoluted with either the nucleon transversity or pretzelosity TMD PDFs. A recent COMPASS SIDIS measurement was obtained at a hard scale comparable to that of these DY results. This opens the way for possible tests of fundamental QCD universality predictions.Peer Reviewe

Final COMPASS results on the deuteron spin-dependent structure function g1dg_1^{\rm d} and the Bjorken sum rule

Final results are presented from the inclusive measurement of deep-inelastic polarised-muon scattering on longitudinally polarised deuterons using a 6 LiD target. The data were taken at 160 GeV beam energy and the results are shown for the kinematic range 1(GeV/c)24GeV/c2 in the mass of the hadronic final state. The deuteron double-spin asymmetry A1d and the deuteron longitudinal-spin structure function g1d are presented in bins of x and Q2 . Towards lowest accessible values of x , g1d decreases and becomes consistent with zero within uncertainties. The presented final g1d values together with the recently published final g1p values of COMPASS are used to again evaluate the Bjorken sum rule and perform the QCD fit to the g1 world data at next-to-leading order of the strong coupling constant. In both cases, changes in central values of the resulting numbers are well within statistical uncertainties. The flavour-singlet axial charge a0 , which is identified in the MS‾ renormalisation scheme with the total contribution of quark helicities to the nucleon spin, is extracted at next-to-leading order accuracy from only the COMPASS deuteron data: a0(Q2=3(GeV/c)2)=0.32±0.02stat±0.04syst±0.05evol . Together with the recent results on the proton spin structure function g1p , the results on g1d constitute the COMPASS legacy on the measurements of g1 through inclusive spin-dependent deep inelastic scattering.Peer Reviewe