Assessment of a doctoral thesis

RESUMEN: Dada la complejidad de los procesos de evaluación de las tesis doctorales, el Comité de Programa del doctorado de Salud Pública de la Facultad Nacional de Salud Pública de la Universidad de Antioquia, efectuó un seminario para discutir diferentes aspectos de este proceso, en el cual participaron estudiantes, directores y miembros de comités de tesis de los estudiantes del program

Patrones de asociación entre variables del suelo y usos del terreno en la cuenca del río La Vieja, Colombia

In the Coffee Belt of Colombia we studied different patterns in land use considering the interaction between abundance, diversity and biomass of soil invertebrates (millipedes, beetles and earthworms), some physicochemical variables and land use intensity. Highest abundance and biomass of Coleoptera were found in Eucalyptus-lulo (Solanum quitoense), with 48 ind. m-2 and 9.4 g fresh weight (gfw) m-2, respectively. Millipede abundance and biomass was higher in the relict forest (53 ind. m-2 and 4.8 gfw m-2, respectively) and in the coffee variety Colombia (39.4 ind. m-2 and 3.1 gfw m-2, respectively). Earthworm abundance was higher in Eucalyptus-lulo (768 ind. m-2) and in the coffee variety Colombia (540 ind. m-2). Biological and physicochemical variables permitted the differentiation of three and four land use patterns, respectively. When they were combined with coinertia analysis, three patterns were distinguished, related to soil moisture, C and N contents and bulk density (p < 0.02). In pastures and the coffee variety Colombia, beetles (Ataenius sp., Onthophagus atriglabrus, Dichotomius satanas) and peregrine earthworms were dominant (Pontoscolex corethrurus, Polypheretima elongata, Dichogaster annae, Perionyx excavatus), soil C and N contents were low and bulk density higher. The analysis showed potential for separating biodiversity-friendly or biodiversity-critical areas and may be useful for land use planning in rural áreas.En el Eje Cafetero de Colombia se diferenciaron patrones de uso del terreno con abundancia, diversidad y biomasa de invertebrados edáficos (coleópteros, diplópodos y lombrices de tierra), algunas variables físico-químicas e intensidad de uso. Los valores más elevados de abundancia y biomasa de coleópteros se encontraron en eucalipto-lulo (Solanum quitoense), con 48 ind. m-2 y 9.4 g peso fresco (g.p.f.) m-2, respectivamente. La abundancia y biomasa de diplópodos fue superior en relicto de selva (53 ind. m-2 y 4.8 g.p.f. m-2, respectivamente) y en cafetales variedad Colombia (39 ind. m-2 y 3.1 g.p.f. m-2, respectivamente). La abundancia de lombrices fue mayor en eucalipto-lulo (768 ind. m-2) y en cafetales variedad Colombia (540 ind. m-2). Las variables biológicas y fisicoquímicas configuraron tres y cuatro patrones de usos del terreno, respectivamente. La coinercia sugirió tres patrones relacionados con humedad, C, N y densidad aparente del suelo (p < 0.02). En pastizales y cafetales variedad Colombia predominaron lombrices peregrinas (Pontoscolex corethrurus, Polypheretima elongata, Dichogaster annae, Perionyx excavatus) o coleópteros (Ataenius sp., Onthophagus atriglabrus, Dichotomius satanas) y los valores para C y N fueron bajos y la densidad aparente mayor. El análisis de la información diferenció coberturas amigables o críticas para la biodiversidad, lo cual es valioso en la planificación del territorio

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Search for top squark production in fully hadronic final states in proton-proton collisions at root s=13 TeV

A search for production of the supersymmetric partners of the top quark, top squarks, is presented. The search is based on proton-proton collision events containing multiple jets, no leptons, and large transverse momentum imbalance. The data were collected with the CMS detector at the CERN LHC at a center-of-mass energy of 13 TeV, and correspond to an integrated luminosity of 137 fb(-1). The targeted signal production scenarios are direct and gluino-mediated top squark production, including scenarios in which the top squark and neutralino masses are nearly degenerate. The search utilizes novel algorithms based on deep neural networks that identify hadronically decaying top quarks and W bosons, which are expected in many of the targeted signal models. No statistically significant excess of events is observed relative to the expectation from the standard model, and limits on the top squark production cross section are obtained in the context of simplified supersymmetric models for various production and decay modes. Exclusion limits as high as 1310 GeVare established at the 95% confidence level on the mass of the top squark for direct top squark production models, and as high as 2260 GeV on the mass of the gluino for gluino-mediated top squark production models. These results represent a significant improvement over the results of previous searches for supersymmetry by CMS in the same final state.Peer reviewe

Measurement of B-c(2S)(+) and B-c*(2S)(+) cross section ratios in proton-proton collisions at root s=13 TeV

Peer reviewe

Search for long-lived particles decaying to jets with displaced vertices in proton-proton collisions at root s=13 Te V

A search is presented for long-lived particles produced in pairs in proton-proton collisions at the LHC operating at a center-of-mass energy of 13 TeV. The data were collected with the CMS detector during the period from 2015 through 2018, and correspond to a total integrated luminosity of 140 fb(-1). This search targets pairs of long-lived particles with mean proper decay lengths between 0.1 and 100 mm, each of which decays into at least two quarks that hadronize to jets, resulting in a final state with two displaced vertices. No significant excess of events with two displaced vertices is observed. In the context of R-parity violating supersymmetry models, the pair production of long-lived neutralinos, gluinos, and top squarks is excluded at 95% confidence level for cross sections larger than 0.08 fb, masses between 800 and 3000 GeV, and mean proper decay lengths between 1 and 25 mm.Peer reviewe

Measurement of the W gamma Production Cross Section in Proton-Proton Collisions at root s=13 TeV and Constraints on Effective Field Theory Coefficients

A fiducial cross section for W gamma production in proton-proton collisions is measured at a center-of-mass energy of 13 TeV in 137 fb(-1) of data collected using the CMS detector at the LHC. The W -> e nu and mu nu decay modes are used in a maximum-likelihood fit to the lepton-photon invariant mass distribution to extract the combined cross section. The measured cross section is compared with theoretical expectations at next-to-leading order in quantum chromodynamics. In addition, 95% confidence level intervals are reported for anomalous triple-gauge couplings within the framework of effective field theory.Peer reviewe

Reconstruction of signal amplitudes in the CMS electromagnetic calorimeter in the presence of overlapping proton-proton interactions

A template fitting technique for reconstructing the amplitude of signals produced by the lead tungstate crystals of the CMS electromagnetic calorimeter is described. This novel approach is designed to suppress the contribution to the signal of the increased number of out-of-time interactions per beam crossing following the reduction of the accelerator bunch spacing from 50 to 25 ns at the start of Run 2 of the LHC. Execution of the algorithm is sufficiently fast for it to be employed in the CMS high-level trigger. It is also used in the offline event reconstruction. Results obtained from simulations and from Run 2 collision data (2015-2018) demonstrate a substantial improvement in the energy resolution of the calorimeter over a range of energies extending from a few GeV to several tens of GeV.Peer reviewe

Observation of the Production of Three Massive Gauge Bosons at root s=13 TeV

The first observation is reported of the combined production of three massive gauge bosons (VVV with V = W, Z) in proton-proton collisions at a center-of-mass energy of 13 TeV. The analysis is based on a data sample recorded by the CMS experiment at the CERN LHC corresponding to an integrated luminosity of 137 fb(-1). The searches for individualWWW, WWZ, WZZ, and ZZZ production are performed in final states with three, four, five, and six leptons (electrons or muons), or with two same-sign leptons plus one or two jets. The observed (expected) significance of the combinedVVV production signal is 5.7 (5.9) standard deviations and the corresponding measured cross section relative to the standard model prediction is 1.02(-0.23)(+0.26). The significances of the individual WWW and WWZ production are 3.3 and 3.4 standard deviations, respectively. Measured production cross sections for the individual triboson processes are also reported

Performance of the CMS muon trigger system in proton-proton collisions at √s = 13 TeV

The muon trigger system of the CMS experiment uses a combination of hardware and software to identify events containing a muon. During Run 2 (covering 2015-2018) the LHC achieved instantaneous luminosities as high as 2 × 10 cm s while delivering proton-proton collisions at √s = 13 TeV. The challenge for the trigger system of the CMS experiment is to reduce the registered event rate from about 40 MHz to about 1 kHz. Significant improvements important for the success of the CMS physics program have been made to the muon trigger system via improved muon reconstruction and identification algorithms since the end of Run 1 and throughout the Run 2 data-taking period. The new algorithms maintain the acceptance of the muon triggers at the same or even lower rate throughout the data-taking period despite the increasing number of additional proton-proton interactions in each LHC bunch crossing. In this paper, the algorithms used in 2015 and 2016 and their improvements throughout 2017 and 2018 are described. Measurements of the CMS muon trigger performance for this data-taking period are presented, including efficiencies, transverse momentum resolution, trigger rates, and the purity of the selected muon sample. This paper focuses on the single- and double-muon triggers with the lowest sustainable transverse momentum thresholds used by CMS. The efficiency is measured in a transverse momentum range from 8 to several hundred GeV