Zero-inflated longitudinal mixture model for stochastic radiographic lung compositional change following radiotherapy of lung cancer

Compositional data (CD) is mostly analyzed as relative data, using ratios of components, and log-ratio transformations to be able to use known multivariable statistical methods. Therefore, CD where some components equal zero represent a problem. Furthermore, when the data is measured longitudinally, observations are spatially related and appear to come from a mixture population, the analysis becomes highly complex. For this matter, a two-part model was proposed to deal with structural zeros in longitudinal CD using a mixed-effects model. Furthermore, the model has been extended to the case where the non-zero components of the vector might a two component mixture population. Maximum likelihood estimates for fixed effects and variance components are calculated by an approximate Fisher scoring procedure base on sixth-order Laplace approximation. The EM algorithm is used to estimate the probability of the mixture model. The proposed model was used to analyze the radiation therapy effect on tissue change in one patient with non-small cell lung cancer (NSCLC). Five CT-scans were obtained during 24 months following RT. Instead of using voxel-level data, voxels were grouped into larger subvolumes called patches. Data in each patch can be represented by a vector in the form of CD with the proportions of tissue classified as dense, hazy, or normal. A statistical model of radiation-induced lung damage (RILD) over time for each patch as a function of time and dose was implemented. The predicted longitudinal compositions were classified to describe tissue change using cluster analysis. Finally, proposed method and cluster analysis were applied to two groups of patients with and without radiation pneumonitis (RP) to characterize tissue changes in RP

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

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 eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M&gt;70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0&lt;e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

La lucha por los comunes y las alternativas al desarrollo frente al extractivismo : miradas desde las ecología(s) política(s) latinoamericanas

Este libro aporta nuevos elementos a los urgentes y necesarios cuestionamientos colectivos, teniendo en cuenta los nuevos paradigmas teóricos y políticos de la transformación social en América Latina en un diálogo entre experiencias de construcción de lo común. Las alternativas al desarrollo, nuestro gran desafío desde la ecología política latinoamericana, implica profundizar estas luchas por la producción de lo común hacia una transformación social que debe abordarse simultáneamente en sus complejas relaciones existentes entre capital, clase, raza, colonialidad, género y naturaleza, ya que son precisamente sus tejidos, enredos e interdependencias históricas los que configuran las bases civilizatorias del sistema que enfrentamos. Del Prólogo

Memorias : XX Congreso Institucional de Investigaciones

Este documento, recoge 10 resúmenes de los trabajos presentados como resultado del proyecto en investigación sobre salud oral e investigación en ingeniería, salud y medio ambiente y biología, para el XX congreso institucional de investigaciones de la Universidad del Bosque. Los productos obtenidos como parte de la investigación son: (1) Condición periodontal en pacientes colombianos con artritis idiopática juvenil (AIJ); (2) Efecto del ácido hipocloroso sobre el sistema amortiguador del pH de la saliva. Estudio in vitro e in vivo; (3) Efecto oxidativo del ácido hipocloroso sobre las proteínas salivales: estudio in vitro; (4) Evaluación del ácido hipocloroso como agente antiplaca para uso en la cavidad oral. Parte I: sustantividad, efecto antiplaca y efectos adversos; (5) Identificación de los factores de virulencia de Klebsiella pneumoniae aislada de cavidad oral asociada a fuentes de contaminación exógena; (6) Modulación de la expresión de factores de crecimiento por ácido hipocloroso sobre fibroblastos gingivales humanos; (7) Potencial de diferenciación y expansión neuronal in vitro a partir de Células Troncales de pulpa dental humana; (8) Resolvina D1 inhibe la expresión de moléculas de adhesión en células endoteliales de arteria coronaria humana estimuladas con lipopolisacárido de P. gingivalis. Estudio in vitro; (9) Viabilidad de microorganismos periodontopáticos y bacilos entéricos después del tratamiento con ácido hipocloroso en comparación con clorhexidina; (10) Modelo in vivo de regeneración ósea mandibular a partir de células troncales dentales humanas.Departamento Administrativo de Ciencia, Tecnología e Innovación [CO] Colciencias1308-519-28960Inducción de disfunción endotelial in vitro por lipopolisacarido de bacterias periodontopaticas e inhibición de la inflamación por resolvina (rvd1) y estatina (rosuvastatina)n

Primer Encuentro Internacional de Experiencias de Investigación en Ciencias Administrativas

Este evento de investigación organizado por la Escuela de Administración de la Universidad del Rosario surgió como una iniciativa para fomentar la investigación formativa en áreas administrativas. El evento, al que asistieron 165 participantes, contó con dos conferencias centrales, 30 ponencias presentadas en 8 simposios y 7 posters. La participación de distintas universidades permitió un intercambio académico muy importante y formativo para los ponentes y asistentes en general, promoviendo el interés por la investigación en el campo de la administración, el cual fue el interés central de este encuentro. Este encuentro recibió el apoyo de las directivas de la Universidad del Rosario, la Señora vicerrectora Stephanie Lavaux, el Señor Decano de la Escuela de Administración, Dr. Alejandro Cheyne, ACBSP (Accreditation Council for Business Schools & Programs) y Asociación Colombiana de Facultades de Administración (ASCOLFA)