Measure-valued weak solutions to some kinetic equations with singular kernels for quantum particles

In this thesis, we present a mathematical study of three problems arising in the kinetic theory of quantum gases. In the first part, we consider a Boltzmann equation that is used to describe the time evolution of the particle density of a homogeneous and isotropic photon gas, that interacts through Compton scattering with a low-density electron gas at non-relativistic equilibrium. The kernel in the kinetic equation is highly singular, and we introduce a truncation motivated by the very-peaked shape of the kernel along the diagonal. With this modified kernel, the global existence of measure-valued weak solutions is established for a large set of initial data. We also study a simplified version of this equation, that appears at very low temperatures of the electron gas, where only the quadratic terms are kept. The global existence of measure-valued weak solutions is proved for a large set of initial data, as well as the global existence of $L^1$ solutions for initial data that satisfy a strong integrability condition near the origin. The long time asymptotic behavior of weak solutions for this simplified equation is also described. In the second part of the thesis, we consider a system of two coupled kinetic equations related to a simplified model for the time evolution of the particle density of the normal and superfluid components in a homogeneous and isotropic weakly interacting dilute Bose gas. We establish the global existence of measure-valued weak solutions for a large class of initial data. The conservation of mass and energy and the production of moments of all positive order is also proved. Finally, we study some of the properties of the condensate density and establish an integral equation that describes its time evolution.MTM2014-52347-C2-1-R of DGE

Evidence of amplitude modulation due to Resonant Mode Coupling in the delta Scuti star KIC5892969

A study of the star KIC5892969 observed by the Kepler satellite is presented. Its three highest amplitude modes present a strong amplitude modulation. The aim of this work is to investigate amplitude variations in this star and their possible cause. Using the 4 years-long observations available, we obtained the frequency content of the full light curve. Then, we studied the amplitude and phase variations with time using shorter time stamps. The results obtained are compared with the predicted ones for resonant mode coupling of an unstable mode with lower frequency stable modes. Our conclusion is that resonant mode coupling is consistent as an amplitude limitation mechanism in several modes of KIC5892969 and we discuss to which extent it might play an important role for other delta Scuti stars

La pandemia de COVID-19: Importancia de estar alerta ante las zoonosis.: The COVID-19 pandemic: The importance of being alert to zoonoses.

The pandemic of Coronavirus Disease - 2019 (COVID) has produced hundreds of thousands of deaths and millions of infected people worldwide, with the consequent collapse of health systems. SARS-CoV-2, the coronavirus causing COVID-19, is a pathogen with a zoonotic origin. The objective of this article is to highlight the importance of being alert to zoonoses, with special reference to COVID-19. First, the general chronology of the COVID-19 pandemic is described, then the characteristics of the coronaviruses are described in detail, especially regarding those of SARS-CoV-2. Subsequently, the One Health concept is highlighted as an appropriate approach to face this zoonosis and other related ones. Furthermore, the importance of unequivocally identifying the SARS-CoV-2 reservoir and intermediate animals as part of the knowledge necessary to develop treatments and a vaccine for COVID-19 and related diseases is highlighted. It is concluded that it is important that the One Health approach be known, communicated and integrated by all health centres and health professionals because, considering the severity of zoonoses such as COVID-19, we should not forget that human health is linked to animal health, and both with environmental health. Finally, it is recommended that health agencies maintain preventive measures and personal distancing to avoid more infections.La pandemia de Enfermedad por Coronavirus – 2019 (COVID) ha producido cientos de miles de muertos y millones de contagiados en el mundo, con el consecuente colapso de los sistemas de salud. SARS-CoV-2, coronavirus causante de COVID-19, es un agente patógeno de origen zoonótico. El objetivo de este artículo es destacar la importancia de estar alerta ante las zoonosis, con especial referencia a COVID-19. Primero, se describe de forma general la cronología de la pandemia de COVID-19, luego se describen en detalle las características de los coronavirus, profundizando en aquellas propias de SARS- CoV-2. Posteriormente, se destaca el concepto de Salud Única como un enfoque apropiado para enfrentar esta zoonosis y otras relacionadas. Además, se destaca la importancia de identificar inequívocamente al reservorio y al intermediario de SARS-CoV-2 como parte del conocimiento necesario para desarrollar tratamientos y una vacuna para COVID-19 y enfermedades relacionadas. Se concluye que es importante que el enfoque de Salud Única sea conocido, difundido e integrado por todos los centros de salud y los profesionales sanitarios ya que, ante la gravedad de zoonosis como COVID-19, no debemos olvidar que la salud humana está vinculada con la salud animal, y estas dos, con la salud ambiental. Finalmente, se recomienda que los organismos de salud mantengan las medidas de prevención y distanciamiento personal para evitar más contagios

Interacción entre vulcanismo, tectónica y sedimentación en una plataforma carbonatada somera: Ejemplo en el Tethys occidental (Jurásico Medio, sureste de la Cordillera Ibérica)

In the southeastern Iberian Range, several mainly volcaniclastic rocks resulting from submarine eruptions can be found interbedded in the Lower‒Middle Jurassic carbonate succession. The geological mapping of the outcrop­ping volcanic rocks reveals that they follow three well marked lineaments of cortical weakness (Teruel, Caudiel and Alcublas Fault Zones), probably caused by the faulting related to the opening and sea‒floor spreading of the Ligurian and Alpine Tethys oceans. The present work introduces the results of the study, which aims to evaluate the tectonosedimentary evolution of a shallow submarine setting affected by volcanism during the Aalenian‒Bajocian boundary (Middle Jurassic). This site, known as “Caudiel volcanic outcrop”, is located at the southeastern part of the Caudiel Fault Zone. The presence of positive subaqueous volcaniclastic reliefs, added to shallow marine plat­forms, strongly affects the depth‒dependent carbonate sedimentation: it induces substantial changes in lithofacies compared to other neighboring areas, or even directly prevents the sedimentation. Moreover, episodic normal fault activity generated a dynamic topography over time, with variable rates of both subsidence and uplifting throughout different areas. The Caudiel outcrop represents a good ancient example of interaction between multiple factors (volcanism, tectonism and sedimentation) in shallow carbonate platforms, where the accommodation changes and the sedimentation rates seem to be subordinate to the local tectonic disturbances.En el sureste de la Cordillera Ibérica (España) existen una serie de afloramientos de rocas volcánicas origi­nadas por erupciones submarinas, principalmente de tipo volcanoclástico, interestratificadas en las sucesiones carbonatadas del Jurásico Inferior y Medio. La cartografía geológica de los afloramientos de rocas volcánicas revela que se encuentran alineados a lo largo de tres elementos de debilidad cortical bien definidos (zonas de falla de Teruel, de Caudiel y de Alcublas), originados probablemente por fracturas relacionadas con la apertura y expansión del Tethys Ligur y del Tethys Alpino. En este trabajo se presentan los resultados del estudio de la evolución tectonosedimentaria de un ambiente submarino somero afectado por la presencia de una acumulación volcánica que tuvo lugar en el Jurásico Medio (límite Aaleniense‒Bajociense). Se trata del afloramiento volcánico de Caudiel, que es el más suroriental de todos los afloramientos localizados en uno de los tres elementos de debilidad estructural mencionados: la Zona de Falla de Caudiel. La presencia de un relieve positivo en el fondo de la plataforma, ya de por sí bastante somera, condiciona la sedimentación carbonatada, muy sensible a la pro­fundidad, hasta el punto de llegar a inducir cambios significativos de facies con respecto a otras áreas cercanas o de impedir la sedimentación. Los movimientos episódicos del substrato generaron una topografía irregular y cambiante a lo largo del tiempo, con tasas variables de hundimiento y levantamiento en diferentes áreas. El aflo­ramiento de Caudiel constituye un buen ejemplo fósil de interacción entre varios factores (vulcanismo, tectónica y sedimentación) en plataformas carbonatadas someras, en las que los cambios de acomodación y las tasas de sedimentación parecen estar subordinadas a perturbaciones tectónicas de carácter local

Teoría social de la comunicación

Texto sobre el trabajo “Teoría social de la comunicación” realizado por Manuel Martín Serrano y su equipo de trabajo de la Universidad Complutense de Madrid. Se hace una reflexión sobre esta propuesta teórica que tiene por objeto la producción social de información pública y se hace mención del seminario realizado en el ITESO del 2 al 5 de marzo de 1987 que contó con la presencia de Manuel Martín Serrano.ITESO, A.C

Critical Steps of Plasmodium falciparum Ookinete Maturation

The egress and fertilization of Plasmodium gametes and development of a motile ookinete are the first crucial steps that mediate the successful transmission of the malaria parasites from humans to the Anopheles vector. However, limited information exists about the cell biology and regulation of this process. Technical impediments in the establishment of in vitro conditions for ookinete maturation in Plasmodium falciparum and other human malaria parasites further constrain a detailed characterization of ookinete maturation. Here, using fluorescence microscopy and immunolabeling, we compared P. falciparum ookinete maturation in Anopheles coluzzii mosquitoes in vivo and in cell culture in vitro. Our results identified two critical steps in ookinete maturation that are regulated by distinct mosquito factors, thereby highlighting the role of the mosquito environment in the transmission efficiency of malaria parasites

On a Boltzmann equation for Compton scattering, from non relativistic electrons at low density.

A Boltzmann equation, used to describe the Compton scattering in the non-relativistic limit is considered. A truncation of the very singular redistribution function is introduced and justified. The existence of weak solutions is proved for a large set of initial data. A simplified equation, where only the quadratic terms are kept, is also studied. The existence of weak solutions, and also of more regular solutions that are very flat near the origin, is proved. The long time asymptotic behavior of weak solutions of the simplified equation is described.MTM2014-52347- C2-1-R of DGE