Estudio proteómico de factores moleculares que coordinan la reprogramación génica estacional del pez Cyprinus carpio

Tesis (Doctor en Biociencias Moleculares)RESUMEN: El pez Cyprinus carpio es un ectotermo euritermal que habita los ríos de la zona central y sur de Chile. En este escenario, se ve enfrentado a las variaciones físicas del medio ambiente propias de un clima con las estaciones claramente diferenciadas. El fenómeno de plasticidad fenotípica concomitante a las variaciones estacionales se conoce como aclimatización, el cual se ve reflejado a nivel fisiológico, celular y molecular. En la carpa, el cambio más notable se observa en el reordenamiento ultraestructural que sufre el nucléolo, el cual durante la estación veraniega presenta sus componentes integrados (con una alta actividad transcripcional), mientras que en invierno sus componentes se observan segregados (representativo de una baja tasa transcripcional). Nuestra hipótesis de trabajo sostiene que la homeostasis que caracteriza la adaptación estacional de la carpa, implica cambios en el repertorio de proteínas nucleares y en él se representan los factores moleculares centrales para la coordinación de la reprogramación génica estacional de C. carpio. Este estudio, permitió demostrar los cambios que sufre el proteoma nuclear de la carpa concomitante a la adaptación estacional, observándose que aproximadamente un 10% de las proteínas presentes en ambas estaciones son reguladas. Adicionalmente, hemos identificado cinco proteínas, dos no mostraron variación estacional y tres se sobre expresaron durante el invierno. Las identidades de estas proteínas nos sugieren la participación de diversos mecanismos regulatorios de la expresión génica en el proceso de aclimatización. La subunidad Rpb7 es necesaria para el inicio de transcripción y Spt4 participa de la elongación de la transcripción, Pur b se ha descrito como represor de ciertos genes en células musculares, mientras que CENP-A y Actina1 muestran funciones asociadas la estructura de la cromatina. Paralelamente, hemos evidenciado que la histona variante H2A.Z presenta una regulación estacional durante el proceso adaptativo. En particular, esta variante de histona se encuentra enriquecida en los genes ribosomales de la carpa (principalmente en verano), y su relación a través de ensayo de reChIp con marcadores epigenéticos de activación (AcK12H4) y represión (DimetK27H3), nos sugiere su participación en la modulación de la actividad transcripcional de los genes ribosomales durante el fenómeno de aclimatización. Las funciones descritas para estas proteínas, nos sugieren que la regulación de la expresión génica se llevaría a cabo a través de factores XII transcripcionales específicos y de la modulación de la estructura de la cromatina. Esto nos indica la concertación de diversos procesos nucleares, los cuales sustentarían la reprogramación génica cíclica como una de las respuestas compensatorias centrales frente a los cambios medioambientales al que debe hacer frente el pez C. carpio.ABSTRACT: The ectotherm eurithermal fish Cyprinus carpio lives in the rivers of the central and south areas of Chile. It faces clearly differentiated seasons and it is subjected to selective pressure impose by environmental fluctuations. The carp adaptative response to this phenomenon is a complex mechanism that involves physiological, cellular and molecular adjustments. The phenotypic plasticity of the carp concomitant to seasonal variations is known as acclimatization. This process involves profound nucleolar adjustments and remarkable changes in RNA synthesis, which affects ribosomal biosynthesis. The hypothesis proposes that the homeostasis which characterizes the seasonal adaptation of the C. carpio in winter and summer, involves changes in the repertory of nuclear proteins and those changes include the central molecular factors for coordinating the seasonal gene reprogramming in C. carpio. This study has demonstrated the changes experienced by the nuclear proteome concomitant upon seasonal acclimatization. It has been observed that 10% of the proteins present in both seasons are regulated. In addition, this work identified five proteins; two without seasonal changes y three were overexpressed during the winter. The identities of these proteins suggest the involvement of various mechanisms of gene expression in the process of acclimatization. Rpb7 is required for the initiation of transcription; Purb has been described as a repressor of certain genes in muscle cells, while CENP-A and Actina1-A shows the functions associated to the chromatin’s structure. Parallel to this, it was shown that H2A.Z presents a seasonal regulation during the adaptative process. This histone variant was demonstrated to be associated with ribosomal genes, mainly in summer. Also, its relationship, tested by reChIp, with activation (AcK12H4) and repression (DimetK27H3) epigenetic markers suggests its involvement in the modulation of ribosomal genes transcription during seasonal acclimatization. The functions of these proteins suggest that gene expression regulation would be carrying out through specific transcriptional factors and changes in chromatin structure. This indicate the diverse nuclear processes coordination, which support the cyclical gene reprogramming as a compensatory response to changes in the physical environment that affects fish C. carpio

Incremental Sampling-based Algorithm for Minimum-violation Motion Planning

This paper studies the problem of control strategy synthesis for dynamical systems with differential constraints to fulfill a given reachability goal while satisfying a set of safety rules. Particular attention is devoted to goals that become feasible only if a subset of the safety rules are violated. The proposed algorithm computes a control law, that minimizes the level of unsafety while the desired goal is guaranteed to be reached. This problem is motivated by an autonomous car navigating an urban environment while following rules of the road such as "always travel in right lane'' and "do not change lanes frequently''. Ideas behind sampling based motion-planning algorithms, such as Probabilistic Road Maps (PRMs) and Rapidly-exploring Random Trees (RRTs), are employed to incrementally construct a finite concretization of the dynamics as a durational Kripke structure. In conjunction with this, a weighted finite automaton that captures the safety rules is used in order to find an optimal trajectory that minimizes the violation of safety rules. We prove that the proposed algorithm guarantees asymptotic optimality, i.e., almost-sure convergence to optimal solutions. We present results of simulation experiments and an implementation on an autonomous urban mobility-on-demand system.Comment: 8 pages, final version submitted to CDC '1

Chapter Un lenguaje grafico para comprender y simular la intangibilidad de paisajes verdes urbanos

The 43rd UID conference, held in Genova, takes up the theme of ‘Dialogues’ as practice and debate on many fundamental topics in our social life, especially in these complex and not yet resolved times. The city of Genova offers the opportunity to ponder on the value of comparison and on the possibilities for the community, naturally focused on the aspects that concern us, as professors, researchers, disseminators of knowledge, or on all the possibile meanings of the discipline of representation and its dialogue with ‘others’, which we have broadly catalogued in three macro areas: History, Semiotics, Science / Technology. Therefore, “dialogue” as a profitable exchange based on a common language, without which it is impossible to comprehend and understand one another; and the graphic sign that connotes the conference is the precise transcription of this concept: the title ‘translated’ into signs, derived from the visual alphabet designed for the visual identity of the UID since 2017. There are many topics which refer to three macro sessions: - Witnessing (signs and history) - Communicating (signs and semiotics) - Experimenting (signs and sciences) Thanks to the different points of view, an exceptional resource of our disciplinary area, we want to try to outline the prevailing theoretical-operational synergies, the collaborative lines of an instrumental nature, the recent updates of the repertoires of images that attest and nourish the relations among representation, history, semiotics, sciences

Bogotá arte urbano o graffiti. Entre la ilegalidad y la forma artística de expresión

The research related to urban graffiti art, design and visual communication, social culture and politics in the city of Bogota, are issues that this research focus. Reviews and interviews were revealing the influence on the community, civil society, politics and the radical confrontation with the law, their classification and their demand different social strata have made public spaces in Bogota a city with walls speakers. Although it is not taken as a bad thing, -for some- vandalism to others, awakens in many different opinions and above all understated assessment of the artists towards a liberal and democratic expression of a system that moves away from any display of traditional art. bición del arte tradicional.La investigación sobre el graffiti relacionado con el arte urbano, el diseño y la comunicación visual, la cultura social y política en la ciudad de Bogotá, son temas que concentran esta investigación. Opiniones y entrevistas fueron revelando la influencia sobre la comunidad, la sociedad civil, la política, y el enfrentamiento radical con la leyes, su clasificación y su exigencia según el estrato social han hecho de los espacios públicos de Bogotá una ciudad con paredes hablantes. Aunque no es tomado como algo malo, -para algunos- vandalismo para otros, despierta en muchos, opiniones diversas y sobre todo una subestimada valoración de los artistas hacia una expresión liberal y democrática de un sistema que los aleja de cualquier exhibición del arte tradicional