Windowed Integral Equation Methods for Problems of Scattering by Defects and Obstacles in Layered Media

This thesis concerns development of efficient high-order boundary integral equation methods for the numerical solution of problems of acoustic and electromagnetic scattering in the presence of planar layered media in two and three spatial dimensions. The interest in such problems arises from application areas that benefit from accurate numerical modeling of the layered media scattering phenomena, such as electronics, near-field optics, plasmonics and photonics as well as communications, radar and remote sensing. A number of efficient algorithms applicable to various problems in these areas are pre- sented in this thesis, including (i) A Sommerfeld integral based high-order integral equation method for problems of scattering by defects in presence of infinite ground and other layered media, (ii) Studies of resonances and near resonances and their impact on the absorptive properties of rough surfaces, and (iii) A novel Window Green Function Method (WGF) for problems of scattering by obstacles and defects in the presence of layered media. The WGF approach makes it possible to completely avoid use of expensive Sommerfeld integrals that are typically utilized in layer-media simulations. In fact, the methods and studies referred in points (i) and (ii) above motivated the development of the markedly more efficient WGF alternative.</p

Estrategia de la Asociación Torácica Latinoamericana (ALAT). Diez metas estratégicas para el desarrollo en 2016–2020

Introduction Respiratory Health in Latin America faces great challenges. Prevalence and impact of respiratory diseases have been increasing in morbidity. Mortality rates have been rising in the region1 and respiratory medicine practice has been developing in a very fast and disorganized way. Our health systemand institutions are inefficient and fragmented. The Human Resources are insufficient and not well trained.2,3 Ensuring a successful and sustainable development of the respiratory medical specialty in this context is a priority for the Latin American Thoracic Association (Asociación Latinoamericana de Tórax – ALAT).4 Twenty years after its foundation, ALAT proposes an institutional strategy for 2016–2020. This project was led by the President and the General Secretary at a first meeting in Panama City on the 4th and 5th of December 2014 and additional sessions during 2015. It broughttogether the members ofthe Executive Committee, directors ofthe committees in charge of Science and Research, Education, International Relations, Congress, members of the Scientific Departments, Past Presidents, Members of ALAT’s staff and external consultants (Fig. 1). Participants were instructed to visualize the future challenges of ALAT and to propose initiatives, goals and plans that were to be presented to the group with a view on how to implement them successfully. Using methodologies and tools generally accepted in strategic business development,5 and taking into consideration successful case stories from related societies,6,7 the work done enabled the group to redefine the mission and the vision of ALAT. It also enabled the group to propose an integrated strategic plan composed of ten strategic goals

Estrategia de la Asociación Latinoamericana de Tórax (ALAT).Los diez objetivos estratégicos para su desarrollo en el quinquenio 2016-2020

4 páginasLa salud respiratoria en América Latina enfrenta grandes desafíos.La prevalencia y el impacto de las enfermedades respiratorias sobre la morbimortalidad en la región ha aumentado y la práctica de la medicina respiratoria ha crecido de forma vertiginosa y desordenada. Nuestros sistemas de salud son ineficientes y fragmentados, y el recurso humano, insuficiente y poco preparad

Capitalismo tardío y sujetos transformadores

El capitalismo histórico ha experimentado, en la escala mundial que hoy le corresponde, profundos cambios que han modificado sustancialmente su componente de acumulación, pero también, de forma significativa, el de regulación, perturbando críticamente su forma de gestionar las inequidades, desigualdades y doxas que él mismo produce. Actualmente, la expansión de un capitalismo autoritario premunido del paradigma mercantil, promueve una cultura individual que ha calado duramente en los sujetos y en los movimientos transformadores de la sociedad, dejándolos sometidos a un nuevo orden/desorden. Las solidaridades colectivas del campo laboral se han fragmentado obligando a los trabajadores a una competitividad que mella sobre la fuerza de sus organizaciones y que afecta las confianzas necesarias para resistir al embate de los poderosos

Capitalismo tardío y sujetos transformadores

El capitalismo histórico ha experimentado, en la escala mundial que hoy le corresponde, profundos cambios que han modificado sustancialmente su componente de acumulación, pero también, de forma significativa, el de regulación, perturbando críticamente su forma de gestionar las inequidades, desigualdades y doxas que él mismo produce. Actualmente, la expansión de un capitalismo autoritario premunido del paradigma mercantil, promueve una cultura individual que ha calado duramente en los sujetos y en los movimientos transformadores de la sociedad, dejándolos sometidos a un nuevo orden/desorden. Las solidaridades colectivas del campo laboral se han fragmentado obligando a los trabajadores a una competitividad que mella sobre la fuerza de sus organizaciones y que afecta las confianzas necesarias para resistir al embate de los poderosos

Los saberes múltiples y las ciencias sociales y políticas

Este libro debe comprenderse como un intento de formalización por escrito de las razones y emociones que animaron el Coloquio Internacional sobre Saberes Múltiples, Ciencias Sociales y Políticas, realizado en la Sede Bogotá de la Universidad Nacional de Colombia (18-21 de octubre de 2016). Este evento contó con la colaboración de la Universidade Nova de Lisboa (CICS - Centro Interdisciplinar de Ciências Sociais), la Universität Freiburg (Suiza), la Unievrsidade Estadual de Montes Claros (Brasil), la Université catholique de Louvain (Bélgica) y la Association internationale des sociologues de langue française (AISLF) en el marco de las actividades del Comité de recherche 30 (CR30) (Inégalités, identités et liens sociaux). Los textos reunidos aquí son testimonios de los debates alrededor de dos perspectivas metodológicas y epistemológicas que con frecuencia se confrontan en el campo de las ciencias sociales y políticas: la monista y la pluralista. Los grandes temas que animaron las discusiones fueron: 1) los movimientos sociales o las sociedades y comunidades en movimiento; 2) los saberes sociales: indígenas, populares y ancestrales; 3) los estudios sobre el género y la diversidad sexual; 4) el ambientalismo, el ecologismo, los estudios sobre el territorio, el desarrollo y el animalismo; 5) la investigación acción participativa, la intervención sociológica y la educación popular; y 6) el debate epistemológico

Lo local: ámbito de contención de la globalización “perversa”

Se escribe que el tiempo y el espacio han perdido su significado tradicional. Por eso Manuel Castells habla de nueva Era y Alain Touraine de ruptura. El Norte está cada vez más disperso y fragmentado y el Sur también. Podría decirse que ahora hay muchos Nortes y muchos Sures. Por eso hay visiones tan distin¬tas del intenso e imprevisible proceso iniciado hace apenas tres décadas. Nadie sabe hacia dónde nos va a conducir el proceso de cambio en esta nueva Era de la información y la comunicación. Existe un consenso básico en torno al final de un «viejo» orden mundial, pero ¿cómo definir el nuevo contexto? Las referencias son tan distintas como distantes: nuevo orden, nuevo desorden, nueva Edad Media, geopolítica de la complejidad, geopolítica de las fractu¬ras, geopolítica del caos, segunda modernidad, modernidad radi¬cal, modernidad líquida, posmodernidad... Las propias ciencias sociales participan de este grado notable de desconcierto. Desde comienzos de la década de 1980, los economistas empiezan a hacer uso de la palabra globalización, la que llega a ser cen¬tral en todas las Ciencias Sociales después de la caída del Muro de Berlín y la desaparición de la Unión Soviética. Aparecen propuestas de «final de los territorios» (Ber¬trand Badie), «ciudades mun¬diales» (Saskia Sassen), «lsociedad-red» (Manuel Castells), «economía de archipiélago» (Pierre Veltz) y los «no-lugares» (Marc Augé), entre muchas otras

Lo local: ámbito de contención de la globalización “perversa”

Se escribe que el tiempo y el espacio han perdido su significado tradicional. Por eso Manuel Castells habla de nueva Era y Alain Touraine de ruptura. El Norte está cada vez más disperso y fragmentado y el Sur también. Podría decirse que ahora hay muchos Nortes y muchos Sures. Por eso hay visiones tan distin¬tas del intenso e imprevisible proceso iniciado hace apenas tres décadas. Nadie sabe hacia dónde nos va a conducir el proceso de cambio en esta nueva Era de la información y la comunicación. Existe un consenso básico en torno al final de un «viejo» orden mundial, pero ¿cómo definir el nuevo contexto? Las referencias son tan distintas como distantes: nuevo orden, nuevo desorden, nueva Edad Media, geopolítica de la complejidad, geopolítica de las fractu¬ras, geopolítica del caos, segunda modernidad, modernidad radi¬cal, modernidad líquida, posmodernidad... Las propias ciencias sociales participan de este grado notable de desconcierto. Desde comienzos de la década de 1980, los economistas empiezan a hacer uso de la palabra globalización, la que llega a ser cen¬tral en todas las Ciencias Sociales después de la caída del Muro de Berlín y la desaparición de la Unión Soviética. Aparecen propuestas de «final de los territorios» (Ber¬trand Badie), «ciudades mun¬diales» (Saskia Sassen), «lsociedad-red» (Manuel Castells), «economía de archipiélago» (Pierre Veltz) y los «no-lugares» (Marc Augé), entre muchas otras

Efficacy and safety of the CVnCoV SARS-CoV-2 mRNA vaccine candidate in ten countries in Europe and Latin America (HERALD): a randomised, observer-blinded, placebo-controlled, phase 2b/3 trial

Background: Additional safe and efficacious vaccines are needed to control the COVID-19 pandemic. We aimed to analyse the efficacy and safety of the CVnCoV SARS-CoV-2 mRNA vaccine candidate. Methods: HERALD is a randomised, observer-blinded, placebo-controlled, phase 2b/3 clinical trial conducted in 47 centres in ten countries in Europe and Latin America. By use of an interactive web response system and stratification by country and age group (18–60 years and ≥61 years), adults with no history of virologically confirmed COVID-19 were randomly assigned (1:1) to receive intramuscularly either two 0·6 mL doses of CVnCoV containing 12 μg of mRNA or two 0·6 mL doses of 0·9% NaCl (placebo) on days 1 and 29. The primary efficacy endpoint was the occurrence of a first episode of virologically confirmed symptomatic COVID-19 of any severity and caused by any strain from 15 days after the second dose. For the primary endpoint, the trial was considered successful if the lower limit of the CI was greater than 30%. Key secondary endpoints were the occurrence of a first episode of virologically confirmed moderate-to-severe COVID-19, severe COVID-19, and COVID-19 of any severity by age group. Primary safety outcomes were solicited local and systemic adverse events within 7 days after each dose and unsolicited adverse events within 28 days after each dose in phase 2b participants, and serious adverse events and adverse events of special interest up to 1 year after the second dose in phase 2b and phase 3 participants. Here, we report data up to June 18, 2021. The study is registered at ClinicalTrials.gov, NCT04652102, and EudraCT, 2020–003998–22, and is ongoing. Findings: Between Dec 11, 2020, and April 12, 2021, 39 680 participants were enrolled and randomly assigned to receive either CVnCoV (n=19 846) or placebo (n=19 834), of whom 19 783 received at least one dose of CVnCoV and 19 746 received at least one dose of placebo. After a mean observation period of 48·2 days (SE 0·2), 83 cases of COVID-19 occurred in the CVnCoV group (n=12 851) in 1735·29 person-years and 145 cases occurred in the placebo group (n=12 211) in 1569·87 person-years, resulting in an overall vaccine efficacy against symptomatic COVID-19 of 48·2% (95·826% CI 31·0–61·4; p=0·016). Vaccine efficacy against moderate-to-severe COVID-19 was 70·7% (95% CI 42·5–86·1; CVnCoV 12 cases in 1735·29 person-years, placebo 37 cases in 1569·87 person-years). In participants aged 18–60 years, vaccine efficacy against symptomatic disease was 52·5% (95% CI 36·2–64·8; CVnCoV 71 cases in 1591·47 person-years, placebo, 136 cases in 1449·23 person-years). Too few cases occurred in participants aged 61 years or older (CVnCoV 12, placebo nine) to allow meaningful assessment of vaccine efficacy. Solicited adverse events, which were mostly systemic, were more common in CVnCoV recipients (1933 [96·5%] of 2003) than in placebo recipients (1344 [67·9%] of 1978), with 542 (27·1%) CVnCoV recipients and 61 (3·1%) placebo recipients reporting grade 3 solicited adverse events. The most frequently reported local reaction after any dose in the CVnCoV group was injection-site pain (1678 [83·6%] of 2007), with 22 grade 3 reactions, and the most frequently reported systematic reactions were fatigue (1603 [80·0%] of 2003) and headache (1541 [76·9%] of 2003). 82 (0·4%) of 19 783 CVnCoV recipients reported 100 serious adverse events and 66 (0·3%) of 19 746 placebo recipients reported 76 serious adverse events. Eight serious adverse events in five CVnCoV recipients and two serious adverse events in two placebo recipients were considered vaccination-related. None of the fatal serious adverse events reported (eight in the CVnCoV group and six in the placebo group) were considered to be related to study vaccination. Adverse events of special interest were reported for 38 (0·2%) participants in the CVnCoV group and 31 (0·2%) participants in the placebo group. These events were considered to be related to the trial vaccine for 14 (<0·1%) participants in the CVnCoV group and for five (<0·1%) participants in the placebo group. Interpretation: CVnCoV was efficacious in the prevention of COVID-19 of any severity and had an acceptable safety profile. Taking into account the changing environment, including the emergence of SARS-CoV-2 variants, and timelines for further development, the decision has been made to cease activities on the CVnCoV candidate and to focus efforts on the development of next-generation vaccine candidates. Funding: German Federal Ministry of Education and Research and CureVac

Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study an international prospective cohort study

We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care. We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care