710 research outputs found

    Condicionantes geologicos en el cruce de la sierra de Valle Fertil. San Juan

    Get PDF
    La Ruta Nacional 150 cruza el norte de la sierra de Valle Fértil con una traza que sigue la quebrada del río Agua de laPeña y del arroyo León. Esta quebrada secciona el Pliegue de la Sierra Morada, y pone al descubierto parte de una de lasmayores cuencas extensionales carbonífero-triásica conocidas en Argentina (Cuenca de Paganzo - Cuenca de IschigualastoVilla Unión), donde afloran sedimentitas depositadas en paleoambientes mayormente fluvio-lacustres.Las sedimentitas de la Cuenca de Paganzo, de edades carboníferas a pérmicas, fueron depositadas en dos grandesdepocentros, oriental y occidental, controlados por fallas en una tectónica de pull-apart. La primera formación, denominadaGuandacol, fue depositada cercana a las fallas. Posteriormente, se depositó la Formación Tupe que registra unaamalgamación progresiva de cuencas apiladas para llegar a formar una cuenca compleja con un piso irregular. Finalmente, durante una etapa de subsidencia gradual y máxima expansión, se deposita la Formación Patquía-De la Cuesta.A lo largo de unos 40 km de extensión se han realizado distintas obras de arte, incluyendo seis túneles con forma de herradura de unos 70 m2 de sección y cinco puentes, dos de ellos en arco. Se analiza en detalle la influencia de las condiciones geológicas en cada sectorFil: Aceituno Cieri, P.. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geología; ArgentinaFil: Zeballos, M.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Rocca, Ricardo Jose. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Martino, Roberto Donato. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Carignano, Claudio Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Estudios Avanzados en Ingeniería y Tecnología. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Estudios Avanzados en Ingeniería y Tecnología; ArgentinaFil: Guereschi, Alina Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Giambastiani, M.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentin

    Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study

    Get PDF
    : The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI

    Management practices for postdural puncture headache in obstetrics : a prospective, international, cohort study

    No full text
    Background: Accidental dural puncture is an uncommon complication of epidural analgesia and can cause postdural puncture headache (PDPH). We aimed to describe management practices and outcomes after PDPH treated by epidural blood patch (EBP) or no EBP. Methods: Following ethics committee approval, patients who developed PDPH after accidental dural puncture were recruited from participating countries and divided into two groups, those receiving EBP or no EBP. Data registered included patient and procedure characteristics, headache symptoms and intensity, management practices, and complications. Follow-up was at 3 months. Results: A total of 1001 patients from 24 countries were included, of which 647 (64.6%) received an EBP and 354 (35.4%) did not receive an EBP (no-EBP). Higher initial headache intensity was associated with greater use of EBP, odds ratio 1.29 (95% confidence interval 1.19-1.41) per pain intensity unit increase. Headache intensity declined sharply at 4 h after EBP and 127 (19.3%) patients received a second EBP. On average, no or mild headache (numeric rating score <= 3) was observed 7 days after diagnosis. Intracranial bleeding was diagnosed in three patients (0.46%), and backache, headache, and analgesic use were more common at 3 months in the EBP group. Conclusions: Management practices vary between countries, but EBP was more often used in patients with greater initial headache intensity. EBP reduced headache intensity quickly, but about 20% of patients needed a second EBP. After 7 days, most patients had no or mild headache. Backache, headache, and analgesic use were more common at 3 months in patients receiving an EBP

    Global attitudes in the management of acute appendicitis during COVID-19 pandemic: ACIE Appy Study

    No full text
    Background: Surgical strategies are being adapted to face the COVID-19 pandemic. Recommendations on the management of acute appendicitis have been based on expert opinion, but very little evidence is available. This study addressed that dearth with a snapshot of worldwide approaches to appendicitis. Methods: The Association of Italian Surgeons in Europe designed an online survey to assess the current attitude of surgeons globally regarding the management of patients with acute appendicitis during the pandemic. Questions were divided into baseline information, hospital organization and screening, personal protective equipment, management and surgical approach, and patient presentation before versus during the pandemic. Results: Of 744 answers, 709 (from 66 countries) were complete and were included in the analysis. Most hospitals were treating both patients with and those without COVID. There was variation in screening indications and modality used, with chest X-ray plus molecular testing (PCR) being the commonest (19\ub78 per cent). Conservative management of complicated and uncomplicated appendicitis was used by 6\ub76 and 2\ub74 per cent respectively before, but 23\ub77 and 5\ub73 per cent, during the pandemic (both P < 0\ub7001). One-third changed their approach from laparoscopic to open surgery owing to the popular (but evidence-lacking) advice from expert groups during the initial phase of the pandemic. No agreement on how to filter surgical smoke plume during laparoscopy was identified. There was an overall reduction in the number of patients admitted with appendicitis and one-third felt that patients who did present had more severe appendicitis than they usually observe. Conclusion: Conservative management of mild appendicitis has been possible during the pandemic. The fact that some surgeons switched to open appendicectomy may reflect the poor guidelines that emanated in the early phase of SARS-CoV-2

    Production of Λ\Lambda and KS0{\rm K}^{0}_{\rm S} in jets in p-Pb collisions at sNN=5\sqrt{s_{\rm NN}} = 5 TeV and pp collisions at s=7\sqrt{s} = 7 TeV

    No full text
    The production of Λ\Lambda baryons and KS0{\rm K}^{0}_{\rm S} mesons (V0{\rm V}^{0} particles) was measured in p-Pb collisions at sNN=5\sqrt{s_{\rm NN}} = 5 TeV and pp collisions at s=7\sqrt{s} = 7 TeV with ALICE at the LHC. The production of these strange particles is studied separately for particles associated with hard scatterings and the underlying event to shed light on the baryon-to-meson ratio enhancement observed at intermediate transverse momentum (pTp_{\rm T}) in high multiplicity pp and p-Pb collisions. Hard scatterings are selected on an event-by-event basis with jets reconstructed with the anti-kTk_{\rm T} algorithm using charged particles. The production of strange particles associated with jets pT,  jetch>10p_{\rm T,\;jet}^{\rm ch}>10 GeV/cc is reported as a function of pTp_{\rm T} in both systems; and its dependence on pTp_{\rm T} with jets pT,  jetch>20p_{\rm T,\;jet}^{\rm ch}>20 GeV/cc and on angular distance from the jet axis, R(V0,  jet)R({\rm V}^{0},\;{\rm jet}), for jets with pT,  jetch>10p_{\rm T,\;jet}^{\rm ch} > 10 GeV/cc are reported in p-Pb collisions. The results are compared with the strange particle production in the underlying event. The Λ/KS0\Lambda/{\rm K}^{0}_{\rm S} ratio associated with jets in p-Pb collisions for R(V0,  jet)<0.4R({\rm V}^{0},\;{\rm jet})<0.4 is consistent with the ratio measured in pp collisions and with the expectation of jets fragmenting in vacuum given by the PYTHIA event generator

    Measurement of Prompt D0^{0}, Λc+\Lambda_{c}^{+}, and Σc0,++\Sigma_{c}^{0,++}(2455) Production in Proton–Proton Collisions at s\sqrt s = 13  TeV

    No full text
    International audienceThe pT-differential production cross sections of prompt D0, Λc+, and Σc0,++(2455) charmed hadrons are measured at midrapidity (|y|&lt;0.5) in pp collisions at s=13  TeV. This is the first measurement of Σc0,++ production in hadronic collisions. Assuming the same production yield for the three Σc0,+,++ isospin states, the baryon-to-meson cross section ratios Σc0,+,++/D0 and Λc+/D0 are calculated in the transverse momentum (pT) intervals 2&lt;pT&lt;12 and 1&lt;pT&lt;24  GeV/c. Values significantly larger than in e+e- collisions are observed, indicating for the first time that baryon enhancement in hadronic collisions also extends to the Σc. The feed-down contribution to Λc+ production from Σc0,+,++ is also reported and is found to be larger than in e+e- collisions. The data are compared with predictions from event generators and other phenomenological models, providing a sensitive test of the different charm-hadronization mechanisms implemented in the models

    Measurement of the production of charm jets tagged with D0^{0} mesons in pp collisions at s \sqrt{s} = 5.02 and 13 TeV

    No full text
    The measurement of the production of charm jets, identified by the presence of a D0{\rm D^0} meson in the jet constituents, is presented in proton–proton collisions at centre-of-mass energies of s\sqrt{s} = 5.02 and 13 TeV with the ALICE detector at the CERN LHC. The D0 mesons were reconstructed from their hadronic decay D0Kπ+{\rm D^0} \rightarrow {\rm K^-}\pi^+ and the respective charge conjugate. Jets were reconstructed from D0{\rm D^0}-meson candidates and charged particles using the anti-kTk_{\rm T} algorithm, in the jet transverse momentum range 5<pT;chjet<505<p_{\rm T;chjet}<50 GeV/cc, pseudorapidity ηjet<0.9R|\eta_{\rm jet}| <0.9-R, and with the jet resolution parameters RR = 0.2, 0.4, 0.6. The distribution of the jet momentum fraction carried by a D0{\rm D^0} meson along the jet axis (zchz^{\rm ch}_{||}) was measured in the range 0.4<zch<1.00.4 < z^{\rm ch}_{||} < 1.0 in four ranges of the jet transverse momentum. Comparisons of results for different collision energies and jet resolution parameters are also presented. The measurements are compared to predictions from Monte Carlo event generators based on leading-order and next-to-leading-order perturbative quantum chromodynamics calculations. A generally good description of the main features of the data is obtained in spite of a few discrepancies at low pT;chjetp_{\rm T;chjet}. Measurements were also done for R=0.3R = 0.3 at s\sqrt{s} = 5.02 TeV and are shown along with their comparisons to theoretical predictions in an appendix to this paper.The measurement of the production of charm jets, identified by the presence of a D0^{0} meson in the jet constituents, is presented in proton–proton collisions at centre-of-mass energies of s \sqrt{s} = 5.02 and 13 TeV with the ALICE detector at the CERN LHC. The D0^{0} mesons were reconstructed from their hadronic decay D0^{0} → K^{−}π+^{+} and the respective charge conjugate. Jets were reconstructed from D0^{0}-meson candidates and charged particles using the anti-kT_{T} algorithm, in the jet transverse momentum range 5 < pT,chjet_{T,chjet}< 50 GeV/c, pseudorapidity |ηjet_{jet}| < 0.9 − R, and with the jet resolution parameters R = 0.2, 0.4, 0.6. The distribution of the jet momentum fraction carried by a D0^{0} meson along the jet axis (zch) \left({z}_{\Big\Vert}^{\textrm{ch}}\right) was measured in the range 0.4 <zch {z}_{\Big\Vert}^{\textrm{ch}} < 1.0 in four ranges of the jet transverse momentum. Comparisons of results for different collision energies and jet resolution parameters are also presented. The measurements are compared to predictions from Monte Carlo event generators based on leading-order and next-to-leading-order perturbative quantum chromodynamics calculations. A generally good description of the main features of the data is obtained in spite of a few discrepancies at low pT,chjet_{T,chjet}. Measurements were also done for R = 0.3 at s \sqrt{s} = 5.02 and are shown along with their comparisons to theoretical predictions in an appendix to this paper.[graphic not available: see fulltext]The measurement of the production of charm jets, identified by the presence of a D0{\rm D^0} meson in the jet constituents, is presented in proton-proton collisions at centre-of-mass energies of s\sqrt{s} = 5.02 and 13 TeV with the ALICE detector at the CERN LHC. The D0{\rm D^0} mesons were reconstructed from their hadronic decay D0Kπ+{\rm D^0} \rightarrow {\rm K^-}\pi^+ and the respective charge conjugate. Jets were reconstructed from D0{\rm D^0}-meson candidates and charged particles using the anti-kTk_{\rm T} algorithm, in the jet transverse momentum range 5<pT;chjet<505<p_{\rm T;chjet}<50 GeV/cc, pseudorapidity ηjet<0.9R|\eta_{\rm jet}| <0.9-R, and with the jet resolution parameters RR = 0.2, 0.4, 0.6. The distribution of the jet momentum fraction carried by a D0{\rm D^0} meson along the jet axis (zchz^{\rm ch}_{||}) was measured in the range 0.4<zch<1.00.4 < z^{\rm ch}_{||} < 1.0 in four ranges of the jet transverse momentum. Comparisons of results for different collision energies and jet resolution parameters are also presented. The measurements are compared to predictions from Monte Carlo event generators based on leading-order and next-to-leading-order perturbative quantum chromodynamics calculations. A generally good description of the main features of the data is obtained in spite of a few discrepancies at low pT;chjetp_{\rm T;chjet}. Measurements were also done for R=0.3R = 0.3 at s\sqrt{s} = 5.02 TeV and are shown along with their comparisons to theoretical predictions in an appendix to this paper

    System-size dependence of the charged-particle pseudorapidity density at <math altimg="si1.svg"><msqrt><mrow><msub><mrow><mi>s</mi></mrow><mrow><mi mathvariant="normal">NN</mi></mrow></msub></mrow></msqrt><mo linebreak="goodbreak" linebreakstyle="after">=</mo><mn>5.02</mn><mspace width="0.2em"/><mtext>TeV</mtext></math> for pp, pPb, and PbPb collisions

    No full text
    International audienceWe present the first systematic comparison of the charged-particle pseudorapidity densities for three widely different collision systems, pp, pPb, and PbPb, at the top energy of the Large Hadron Collider (sNN=5.02TeV) measured over a wide pseudorapidity range (−3.5&lt;η&lt;5), the widest possible among the four experiments at that facility. The systematic uncertainties are minimised since the measurements are recorded by the same experimental apparatus (ALICE). The distributions for pPb and PbPb collisions are determined as a function of the centrality of the collisions, while results from pp collisions are reported for inelastic events with at least one charged particle at midrapidity. The charged-particle pseudorapidity densities are, under simple and robust assumptions, transformed to charged-particle rapidity densities. This allows for the calculation and the presentation of the evolution of the width of the rapidity distributions and of a lower bound on the Bjorken energy density, as a function of the number of participants in all three collision systems. We find a decreasing width of the particle production, and roughly a smooth ten fold increase in the energy density, as the system size grows, which is consistent with a gradually higher dense phase of matter

    Measurements of mixed harmonic cumulants in Pb–Pb collisions at sNN\sqrt {s_{NN}} = 5.02 TeV

    No full text
    Correlations between moments of different flow coefficients are measured in Pb–Pb collisions at sNN\sqrt {s_{NN}} = 5.02 TeV recorded with the ALICE detector. These new measurements are based on multiparticle mixed harmonic cumulants calculated using charged particles in the pseudorapidity region |η|<0.8 with the transverse momentum range 0.2 < pTp_T < 5.0 GeV/c . The centrality dependence of correlations between two flow coefficients as well as the correlations between three flow coefficients, both in terms of their second moments, are shown. In addition, a collection of mixed harmonic cumulants involving higher moments of v2v_2 and v3v_3 is measured for the first time, where the characteristic signature of negative, positive and negative signs of four-, six- and eight-particle cumulants are observed, respectively. The measurements are compared to the hydrodynamic calculations using iEBE-VISHNU with AMPT and TRENTo initial conditions. It is shown that the measurements carried out using the LHC Run 2 data in 2015 have the precision to explore the details of initial-state fluctuations and probe the nonlinear hydrodynamic response of v2v_2 and v3v_3 to their corresponding initial anisotropy coefficients ε2ε_2 and ε3ε_3 . These new studies on correlations between three flow coefficients as well as correlations between higher moments of two different flow coefficients will pave the way to tighten constraints on initial-state models and help to extract precise information on the dynamic evolution of the hot and dense matter created in heavy-ion collisions at the LHC

    Inclusive J/ψ\psi production at midrapidity in pp collisions at s = 13\sqrt{s}~=~13 TeV

    No full text
    We report on the inclusive J/ψ\psi production cross section measured at the CERN Large Hadron Collider in proton-proton collisions at a centre-of-mass energy s = 13\sqrt{s}~=~13 TeV. The J/ψ\psi mesons are reconstructed in the e+e\rm e^{+} e^{-} decay channel and the measurements are performed at midrapidity (y<0.9|y|<0.9) in the transverse-momentum interval 0<pT<400< p_{\rm T} <40 GeV/cc, using a minimum bias data sample corresponding to an integrated luminosity Lint=32.2 nb1L_{\text{int}} = 32.2~\text{nb}^{-1} and an Electromagnetic Calorimeter triggered data sample with Lint=8.3 pb1L_{\text{int}} = 8.3~\mathrm{pb}^{-1}. The pTp_{\rm T}-integrated J/ψ\psi production cross section at midrapidity, computed using the minimum bias data sample, is dσ/dyy=0=8.97±0.24 (stat)±0.48 (syst)±0.15 (lumi) μb\text{d}\sigma/\text{d}y|_{y=0} = 8.97\pm0.24~(\text{stat})\pm0.48~(\text{syst})\pm0.15~(\text{lumi})~\mu\text{b}. An approximate logarithmic dependence with the collision energy is suggested by these results and available world data, in agreement with model predictions. The integrated and pTp_{\rm T}-differential measurements are compared with measurements in pp collisions at lower energies and with several recent phenomenological calculations based on the non-relativistic QCD and Color Evaporation models
    corecore