Kinetic wealth-exchange model of economic growth

En esta tesis se propone un modelo cinético de intercambio de riqueza con crecimiento económico (KWEMEG) en el que se explora el efecto del ahorro de la producción, los im- puestos con beneficio tributario y la aversión al intercambio, sobre las distribuciones de riqueza y de dinero. Este modelo se obtiene a partir de una extensión al formalismo mi- croeconómico del modelo de Chakraborti y Chakrabarti (CCM), donde las preferencias de consumo se describen mediante funciones de utilidad tipo Cobb-Douglas. Al maximizar es- tas funciones, sujetas a ciertas restricciones sobre el consumo, se obtienen reglas generales de interacción entre agentes económicos, caracterizadas por la emergencia de un régimen conservativo, donde la riqueza total se mantiene constante en el tiempo y las interacciones entre agentes se reducen a meros intercambios monetarios; y un régimen no conservativo, en el cual la riqueza crece exponencialmente, induciendo un efecto de crecimiento económi- co a tasa constante. Como casos particulares del KWEMEG se presentan por separado en esta tesis tres nuevos modelos en el contexto de la econofı́sica, que extienden el CCM. Su dinámica macroscópica se estudia analı́ticamente en todos los casos, utilizando la ecuación cinética de Boltzmann; y numéricamente por medio de simulaciones de Monte Carlo. Esto permite ajustar las distribuciones emergentes a densidades de probabilidad tipo gamma, y establecer relaciones analı́ticas para sus parámetros, ası́ como para el ı́ndice de Gini, con el cual se estudia el nivel de desigualdad en las distribuciones. Adicionalemente, en el régimen no conservativo es posible estudiar distribuciones auto-semejantes utilizando una aproxima- ción de campo medio, que abre la puerta a la discusión sobre la posible existencia de colas de Pareto. Como un resultado general, al agregar en el modelo un efecto relacionado con el ingreso por salario, se obtiene como una propiedad emergente la Segunda ley fundamental del capitalismo, de Piketty. Las ideas propuestas en este trabajo atan algunos de los problemas de la economı́a moderna con el discurso tradicional de los modelos cinéticos de intercambio y proponen un puente que conecta de forma efectiva la microfundamentación basada en la maximización de la función de utilidad y los modelos no conservativos. Ambos resultados son novedosos en el contexto de la econofı́sica.This thesis proposes a Kinetic wealth-exchange model of economic growth (KWEMEG) which explores the effects of saving of production, tax benefits with redistribution, and exchange aversion, over the wealth and the money distributions. The model is achieved extending the microeconomic formalism of the Chakraborti and Chakrabarti model (CCM), based on the Cobb-Douglas utility functions describing the preferences for consumption. The maximization of this functions, subjected to certain constraints over consumption leads to general rules of interaction between economic agents that induces the emergence of a conservative regime, where the total wealth of the system remains constant in time, and the interactions between agents are reduced to mere monetary exchanges; and a non-conservative regime, where the wealth and income increase exponentially, inducing an effect of economic growth with a constant rate. The particular cases of the KWEMEG set three new models in the context of econophysics that extend the CCM. All the cases are presented separately in the thesis, and their macroscopic dynamics are studied using the Boltzmann kinetic equation and Monte Carlo simulations, which allows to fit the emergent distributions to the gamma probability density function and to establish analytical relations for its parameters and the evolution of the economic inequality in terms of the Gini index. In addition, it is possible to study a mean field approach for self-similar distributions that allows to discuss the possibility of Pareto tails in the non-conservative regime. As a general result, the model leads to Piketty’s second fundamental law of capitalism as an emergent property, by adding an effect of income due to salary. The ideas developed in this work tie some of the problems of modern economics with the traditional speech of kinetic exchange models of markets, and propose an effective bridge between the microfoundation based on the maximization of the utility function and the non-conservative models. Both results are new in the context of econophysics.Maestrí

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

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Libro de Proyectos Finales 2021 primer semestre

PregradoIngeniero CivilIngeniero de SistemasIngeniero ElectricistaIngeniero ElectrónicoIngeniero IndustrialIngeniero Mecánic

Risk of COVID-19 after natural infection or vaccinationResearch in context

Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health

Risk of COVID-19 after natural infection or vaccinationResearch in context

Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health