381 research outputs found
Economic, Health-Care and Teaching-Learning Impact of COVID-19 (SARS-CoV-2) on Dentistry
The aim of this chapter is to look more closely at the impact that the crisis generated by the SARS-CoV-2 is having on health, the economy and education in the field of dentistry. The considerations that must be taken into account in dental practice will be presented, as well as the usefulness that the use of teledentistry (TD) could have in times of pandemic, reflecting on the different specialties of dentistry that can benefit from this modality, as well as the advantages and disadvantages that its use can present. Likewise, teaching has been condemned to a lack of presence, having to resort to distance learning, both synchronous and non-synchronous, which can cause needs and deficiencies in undergraduate and postgraduate students. We will analyse the health risks in the dental field and the changes and needs for safe dentistry in times of pandemic. We will also break down the effect of the crisis on the medical-dental sector and the economy, from the point of view of patients and professionals, especially in times of increased restriction and confinement worldwide
Caracterización de Xylella fastidiosa a partir de materiales vegetales y cepas aisladas de olivo (Olea europaea L.) e implementación de un sistema de diagnóstico serológico en Argentina
Xylella fastidiosa está considerada plaga cuarentenaria de importancia global por el grave impacto económico y social que ocasiona en cultivos de importancia agrícola. El objetivo de este trabajo fue aislar y caracterizar cepas bacterianas y muestras vegetales infectadas con X. fastidiosa de plantas de olivo (Olea europaea L.) e implementar un sistema de diagnóstico serológico para su detección. Para la caracterización molecular se utilizó el sistema de tipificación multilocus de secuencias (MLST). Se logró el aislamiento de la bacteria desde olivo y se determinó que todos los materiales caracterizados corresponden a X. fastidiosa subespecie pauca ST69, un grupo genético solo presente en Argentina. Se elaboraron reactivos serológicos fundamentales para la puesta a punto de técnicas de diagnóstico. Con la técnica DAS ELISA se logró un sistema de diagnóstico rápido, robusto y económico, permitiendo resolver la ausencia de disponibilidad continua de reactivos serológicos específicos para X. fastidiosa.Xylella fastidiosa is considered a quarantine pest of global significance due to the severe economic and social damage it causes on most valuable crops. The objective of this work was to isolate and characterize bacterial strains of infected with X. fastidiosa of olive (Olea europaea L.) samples and implement a serological diagnostic system for their detection. For the molecular characterization, the multilocus sequence typing system (MLST) was used. The isolation of the bacterium from the olive tree was achieved and it was determined that all materials characterized correspond to X. fastidiosa subsp. pauca ST69, a genetic subgroup that has been detected only in Argentina. An antiserum was produced and serological diagnosis systems were adjusted. A solid, fast and economical diagnostic method DAS ELISA system was achieved, solving the continuous lack of availability of serological reagents for X. fastidiosa.Fil: Tolocka, Patricia Andrea. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Giolitti, Fabián José. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Guzmán, F. A.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Mattio, Maria Fernanda. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nome, C. F.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Ortega, Leandro Ismael. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Fisiología y Recursos Genéticos Vegetales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Paccioretti, M. A.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Roca, Monica Esther María. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; Argentina. Universidad Nacional de La Rioja; ArgentinaFil: Otero, M. L.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Haelterman, Raquel Mercedes. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; Argentin
Precise measurement of the top quark mass in the dilepton channel at D0
We measure the top quark mass (mt) in ppbar collisions at a center of mass
energy of 1.96 TeV using dilepton ttbar->W+bW-bbar->l+nubl-nubarbbar events,
where l denotes an electron, a muon, or a tau that decays leptonically. The
data correspond to an integrated luminosity of 5.4 fb-1 collected with the D0
detector at the Fermilab Tevatron Collider. We obtain mt = 174.0 +- 1.8(stat)
+- 2.4(syst) GeV, which is in agreement with the current world average mt =
173.3 +- 1.1 GeV. This is currently the most precise measurement of mt in the
dilepton channel.Comment: 7 pages, 4 figure
A search for charged massive long-lived particles
We report on a search for charged massive long-lived particles (CMLLPs),
based on 5.2 fb of integrated luminosity collected with the D0 detector
at the Fermilab Tevatron collider. We search for events in which one
or more particles are reconstructed as muons but have speed and ionization
energy loss inconsistent with muons produced in beam collisions.
CMLLPs are predicted in several theories of physics beyond the standard model.
We exclude pair-produced long-lived gaugino-like charginos below 267 GeV and
higgsino-like charginos below 217 GeV at 95% C.L., as well as long-lived scalar
top quarks with mass below 285 GeV.Comment: submitted to Phys. Rev. Letter
Direct measurement of the mass difference between top and antitop quarks
We present a direct measurement of the mass difference between top and
antitop quarks (dm) in lepton+jets top-antitop final states using the "matrix
element" method. The purity of the lepton+jets sample is enhanced for
top-antitop events by identifying at least one of the jet as originating from a
b quark. The analyzed data correspond to 3.6 fb-1 of proton-antiproton
collisions at 1.96 TeV acquired by D0 in Run II of the Fermilab Tevatron
Collider. The combination of the e+jets and mu+jets channels yields dm = 0.8
+/- 1.8 (stat) +/- 0.5 (syst) GeV, which is in agreement with the standard
model expectation of no mass difference.Comment: submitted to Phys. Rev.
Search for single vector-like quarks in ppbar collisions at sqrt(s) = 1.96 TeV
We present a search for hypothetical vector-like quarks in ppbar collisions
at sqrt(s) = 1.96 TeV. The data were collected by the D0 detector at the
Fermilab Tevatron Collider and correspond to an integrated luminosity of 5.4
fb^(-1). We select events with a final state composed of a W or Z boson and a
jet consistent with a heavy object decay. We observe no significant excess in
comparison to the background prediction and set limits on production cross
sections for vector-like quarks decaying to W+jet and Z+jet. These are the most
stringent mass limits for electroweak single vector-like quark production at
hadron colliders.Comment: submitted to Phys. Rev. Let
Measurements of single top quark production cross sections and |Vtb| in ppbar collisions at sqrt{s}=1.96 TeV
We present measurements of production cross sections of single top quarks in
\ppbar collisions at in a data sample corresponding
to an integrated luminosity of collected by the D0 detector
at the Fermilab Tevatron Collider. We select events with an isolated electron
or muon, an imbalance in transverse energy, and two, three, or four jets, with
one or two of them containing a bottom hadron. We obtain an inclusive cross
section of \sigma({\ppbar}{\rargap}tb+X, tqb+X) = 3.43\pm^{0.73}_{0.74}\;\rm
pb and use it to extract the CKM matrix element at
the 95% C.L. We also measure \sigma({\ppbar}{\rargap}tb+X) =
0.68\pm^{0.38}_{0.35}\;\rm pb and \sigma({\ppbar}{\rargap}tqb+X) =
2.86\pm^{0.69}_{0.63}\;\rm pb when assuming, respectively, and
production rates as predicted by the standard model.Comment: 11 pages, 8 figures, submitted to Phys. Rev.
Measurement of the top quark pair production cross section in the lepton+jets channel in proton-antiproton collisions at =1.96 TeV
We present a measurement of the inclusive top quark pair production cross
section in \ppbar collisions at (\sqrt{s}=1.96) TeV utilizing data
corresponding to an integrated luminosity of \lumi\ collected with the D0
detector at the Fermilab Tevatron Collider. We consider final states containing
one high- isolated electron or muon and at least two jets, and we
perform three analyses: one exploiting specific kinematic features of \ttbar
events, the second using -jet identification, and the third using both
techniques to separate \ttbar\ signal from background. In the third case, we
determine simultaneously the cross section and the ratio of the
production rates of +heavy flavor jets and +light flavor jets, which
reduces the impact of the systematic uncertainties related to the background
estimation. Assuming a top quark mass of 172.5 GeV, we obtain
pb. This result agrees with
predictions of the standard model.Comment: 19 pages, 6 figures, submitted to Phys. Rev.
Zgamma production and limits on anomalous ZZgamma and Zgammagamma couplings in ppbar collisions at sqrt(s)=1.96 TeV
We present a measurement of ppbar->Zgamma->ll+gamma (l = e, mu) production
with a data sample corresponding to an integrated luminosity of 6.2 fb^{-1}
collected by the D0 detector at the Fermilab Tevatron ppbar Collider. The
results of the electron and muon channels are combined, and we measure the
total production cross section and the differential cross section
dsigma/dp_T^gamma, where p_T^gamma is the momentum of the photon in the plane
transverse to the beamline. The results obtained are consistent with the
standard model predictions from next-to-leading order calculations. We use the
transverse momentum spectrum of the photon to place limits on anomalous ZZgamma
and Zgammagamma couplings
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