Abstract: In Bogota as in many Latin American cities, an important amount of human settlements were originally occupied by non-formal and non-planned ways, because of the high demographic growth, the internal conflict and the low capacity of the government to provide housing, among others. Non-formal settlements in Bogotá represent nowadays a permanent housing and living solution for milliards of citizens and the government has been forced to recognize them as legal, so these have become valuable in terms of urban land tenure. However in Colombia, with a geographically complex environment, the precarious origins of these settlements and the historical absence of governance have resulted in setting up several risks. Faced with this type of conflicts, public administration promotes the execution of engineering solutions or the imposition of restrictive measures on land use, which includes the resettlement of the people. Different social organizations from these zones impacted by resettlement, have been joining forces into what is being shaped as a Platform of People Affected by Risk and Resettlement, called ARRAIGO (term in Spanish for Rooting). The purposes of the Platform are to promote discussions that impact public policies related with resettlement, to join efforts required to restore the rights of population, to share knowledge of all the actors involved and to find innovative solutions to be implemented in this zones. The present paper examines the social conflict underlying the emergence of ARRAIGO as social phenomena, the significance of the initiative and the theoretical fundamentals that may explain the mismatching with the public policies for risk resettlement of population. It fosters to open new approaches to understand and manage risk, putting the people in the centre, understanding ARRAIGO as a social movement that must be considered to enrich discussions on risk management, governance, resilience, adaptation and their implications in a context of urban policy.

Resumen: Los desarrollos de origen informal en Bogotá, han significado una solución de vivienda legítimamente reconocida, mediante la cual millares de colombianos de escasos recursos han accedido al dominio o propiedad del suelo de una importante proporción del área urbana de la ciudad. Sin embargo, en un contexto geográficamente complejo como el de Colombia, la precariedad en el origen de estos asentamientos, la ausencia prolongada del Estado y los pasivos históricos, han configurado desequilibrios en los territorios los cuales se manifiestan en conflictos socio-ambientales, como es el caso de las problemáticas caracterizadas como riesgo de origen antrópico o natural. La administración pública ante este tipo de fenómenos acude a la imposición de una serie de «categorías» como «alto riesgo», «zona de protección» o «reserva», cuyo carácter político es analizado y problematizado como una operación geográfica del poder, que se ejecuta en correspondencia con los denominados «dispositivos biopolíticos» de «destrucción creativa», proyectando sobre el espacio social una coherencia que en su aplicación oculta, desplaza y reprime una serie de contradicciones que pretenden ser cartografiadas. Ante la destrucción creativa se detecta la activación de una serie de manifestaciones de vitalidad social, cuyo común denominador podría denominarse como «arraigo», entendido como una fuerza que vincula a la población con su construcción territorial, dinamizando la configuración de sujetos políticos y mecanismos de apropiación, des-alienación, con la consigna de habitar el riesgo, procesada a través de los conceptos de «ciudad posible», «máxima diferencia», «autogestión» y «derecho a la ciudad» de Henri Lefevbre. Se analizan las consecuencias y posibilidades del despliegue de un discurso desde el arraigo, como una base teórica de las reivindicaciones y una plataforma programática, frente a las lógicas institucionales en Bogotá. Abstract: The informal developments in Bogotá have meant a legitimately recognized housing solution, through which thousands of low-income Colombians have accessed land ownership or ownership of a significant proportion of the urban area of ​​the city. However, in a geographically complex context such as that of Colombia, the precariousness in the origin of these settlements, the prolonged absence of the State and historical liabilities, have configured imbalances in the territories which are manifested in socio-environmental conflicts, such as the case of problems characterized as risk of anthropic or natural origin. The public administration before this type of phenomena resort to the imposition of a series of «categories» such as «high risk», «protection zone» or «reserve», whose political character is analyzed and problematized as a geographical operation of power, which it is executed in correspondence with the so-called "biopolitical devices" of "creative destruction", projecting on the social space a coherence that, in its hidden application, displaces and represses a series of contradictions that are intended to be mapped. Faced with creative destruction, the activation of a series of manifestations of social vitality is detected, the common denominator of which could be called "roots", understood as a force that links the population with its territorial construction, dynamizing the configuration of political subjects and mechanisms of appropriation, de-alienation, with the slogan of inhabiting risk, processed through the concepts of "possible city", "maximum difference", "self-management" and "right to the city" by Henri Lefevbre. The consequences and possibilities of the deployment of a discourse from the roots are analyzed, as a theoretical base of the demands and a programmatic platform, in front of the institutional logics in Bogotá.

Resumen: Altos de la Estancia en Ciudad Bolívar, Bogotá (Colombia), sufrió uno de los deslizamientos urbanos más grandes en América Latina. En total hubo aproximadamente 2.000.000 m3 de material desplazado, 3.305 familias reasentadas equivalente a 15.000 personas, 16 barrios afectados y un polígono de 73 hectáreas declarado en suelo de protección. Se trata de un ejemplo de la desadaptación institucional, territorial y social de un área que empezó a ser considerada por la comunidad como peligrosa, por la reducida atención del Estado y por su condición de zona de Alto Riesgo. En este sentido, se propone un Programa Integral de Gestión de Riesgo dentro del Plan de Desarrollo de Bogotá Humana 2012-2015 que promovió generar territorios menos vulnerables frente a riesgos y el cambio climático, con acciones integrales a través de procesos de planificación urbana participativa y generación de capacidades hacia la resiliencia. Abstract: Altos de la Estancia in Ciudad Bolívar, Bogotá (Colombia), suffered one of the largest urban landslides in Latin America. In total there were approximately 2,000,000 m3 of displaced material, 3,305 resettled families equivalent to 15,000 people, 16 affected neighborhoods and a 73-hectare polygon declared as protected land. This is an example of the institutional, territorial and social maladjustment of an area that began to be considered by the community as dangerous, due to the reduced attention of the State and due to its status as a High Risk area. In this sense, a Comprehensive Risk Management Program is proposed within the Bogotá Humana Development Plan 2012-2015 that promoted the generation of territories that are less vulnerable to risks and climate change, with comprehensive actions through participatory urban planning processes and capacity building towards resilience.

Abstract: This PhD dissertation addresses the open and collaborative mode of production in software. Specifically, it examines how various practices in the software culture have evolved and their relevance in the construct of the network society. It begins with a philosophical discussion in which a modern philosophy of technology points to technology as a system of thought and software as a technical culture. Not unlike the open and collaborative mode of production, software is source of metaphors. Upon these foundations, it undertakes the evolution of open practices from a historical and structural position. The historical account follows the premise that open collaborative practices of software precede the well-known Free/Libre Open Source Software (FLOSS). It presents some examples, first, related to the history of software and then to computer networks to track the motives and transformation of the open collaboration metaphor. The structural approach presents modern open collaboration in software as the result of a sociotechnical network composed of actants (node/artifacts), executed, in turn, by a collective made up of a human community and technical developments, in which textual machines for coding and communication are highlighted. Finally, the conclusion posits the findings and three modes of agency in software (algorithmic, interactive, and distributive). It also and suggests hybridization as the means to overcomes some shortcomings of the software open metaphor rhetoric. Resumen: Esta tesis doctoral aborda el modo de producción abierto y colaborativo del software. En concreto, examina cómo han evolucionado diversas prácticas de la cultura del software y su relevancia en la construcción de la sociedad en red. Comienza con una discusión filosófica en la que una filosofía moderna de la tecnología apunta a la tecnología como un sistema de pensamiento y al software como una cultura técnica. Al igual que el modo de producción abierto y colaborativo, el software es fuente de metáforas. Sobre estos fundamentos, emprende la evolución de las prácticas abiertas desde una posición histórica y estructural. El relato histórico parte de la premisa de que las prácticas abiertas y colaborativas del software preceden al conocido software libre de código abierto (FLOSS). Presenta algunos ejemplos, primero, relacionados con la historia del software y, después, con las redes informáticas para rastrear los motivos y la transformación de la metáfora de la colaboración abierta. El enfoque estructural presenta la colaboración abierta moderna en el software como el resultado de una red sociotécnica compuesta por actantes (nodos/artefactos), ejecutados, a su vez, por un colectivo formado por una comunidad humana y por desarrollos técnicos, en los que destacan las máquinas textuales de codificación y comunicación. Por último, la conclusión postula los hallazgos y tres modos de agencia en el software (algorítmica, interactiva y distributiva). También sugiere la hibridación como medio para superar algunas deficiencias de la retórica de la metáfora abierta del software.

Abstract: Science and technology are changing. We have seen the emergence of open and citizen-based science practices in the context of facing pandemics, such as COVID-19, xenophobia, or inequality, among others. Open science is a movement that advocates the collective construction of knowledge. This perspective has shown its importance with the emergence of rapid response initiatives to the current situation at national and international levels. This article discusses the relevance of knowledge commons and transparent objects in the era of intellectual property. Solidarity technoscientific initiatives become a vehicle to pose free culture as a pillar of a human future based on mutual support. In that sense, universities, publishers, students, the scientific and engineering community, and even citizens are creating efforts around open science intending to share results, data, designs, specifications, and even resources despite new socio-political limits and precautions. We argue that a technoscientific movement based on solidarity, free and open culture, is key to permeate and transform the various layers of governments, research institutions, and citizens-led initiatives. To address this, several examples are exposed offering a brief critical appraisal in the context of open science, a concept still in the making.

Abstract: The objective of this study is to quantitatively estimate the probability of transmission of the SARS-CoV-2 virus inside the train carriage and to develop a simulation for the model based on the passenger demand for calculating the risk associated with origin-destination. The transmission rate of the virus in train carriage was analyzed using trip data from Pakenham Station to Flinders Street Station in Melbourne, Victoria, Australia, and the modified Wells-Riley model.

Abstract: The concept of semi-regular sequences was introduced in order to assess the complexity of Gröumlbner basis algorithms such as F4 for the solution of polynomial equations. Despite the experimental evidence that semi-regular sequences are common, it was unknown whether there existed semi-regular sequences for all n, except in extremely trivial situations. In the present work, I prove some results on the existence and non-existence of semi-regular sequences. It was observed by J. Schlather and T. Hodges that if an element of degree d in Β(n)-variables is semi-regular, then we must have n≤3d. In this thesis, I establish precisely when the elementary symmetric polynomial of degree d is semi-regular. In particular, when d=2t and n=3d, the elementary symmetric polynomial of degree d is semi-regular establishing that the bound given by J. Schlather and T. Hodges is sharp for infinitely many n. For the general case of existence of semi-regular sequences Bardet, Faug&egravere and Salvy conjecture that the proportion π(n, m, d1, . . . , dm) of semiregular sequences over F2 in the set Ε(n, m, d1, . . . , dm) of algebraic systems of mequations of degrees d1, . . . , dm in n-variables tends to 1 as n tends to infinity. In this work, I show that for a fixed choice of (m, d1, . . . , dm), we have that limn→∞ π(n, m, d1, .. . , dm ) — 0 showing that the conjecture is false in this case.

Semi-regular sequences over F2 are sequences of homogeneous elements of the algebra B(n) = F2[X1, ...,Xn]/(X21, ...,X2n), which have as few relations between them as possible. They were introduced in order to assess the complexity of Gröbner basis algorithms such as F4, F5 for the solution of polynomial equations. Despite the experimental evidence that semi-regular sequences are common, it was unknown whether there existed semi-regular sequences for all n, except in extremely trivial situations. We prove some results on the existence and non-existence of semi-regular sequences. In particular, we show that if an element of degree d in B(n) is semi-regular, then we must have n ≤3d. Also, we show that if d = 2t and n = 3d there exits a semi-regular element of degree d establishing that the bound is sharp for infinitely many n. Finally, we generalize the result of non-existence of semi-regular elements to the case of sequences of a fixed length m.

Semi-regular sequences over F2 are sequences of homogeneous elements of the algebra B(n) = F2[X1,…, Xn]/(X2 1,…, X2n), which have as few relations between them as possible. It is believed that most such systems are F2-semi-regular and this property has important consequences for understanding the complexity of Gröbner basis algorithms such as F4 and F5 for solving such systems. In fact even in one of the simplest and most important cases, that of quadratic sequences of length n in n variables, the question of the existence of semi-regular sequences for all n remains open. In this paper we present a new framework for the concept of F2-semi-regularity which we hope will allow the use of ideas and machinery from homological algebra to be applied to this interesting and important open question. First we introduce an analog of the Koszul complex and show that F2-semi-regularity can be characterized by the exactness of this complex. We show how the well known formula for the Hilbert series of a F2-semi-regular sequence can be deduced from the Koszul complex. Finally we show that the concept of first fall degree also has a natural description in terms of the Koszul complex.

Abstract: The present dissertation consists of three main chapters of self-contained works about international human migration and migrant's integration in the host society. The empirical studies can be read independently since each chapter addresses a research question and contains a specific literature review, methodology, empirical results, conclusions, and discussion of the results. As a summary: first, it estimates the joint effects of the preexisting stocks of migrant and ancestral distance to predict migration inflows. Second, it studies the children of migrants in the United States of America, their performance in high school when compared to the children of natives, and the role of educational aspirations and expectations as determinant factors behind their educational performance. Third, it examines international students and the role of financial aid on the successful completion of higher education abroad using data from Colfuturo's scholarship loan program. Resumen: La presente tesis consta de tres capítulos principales dedicados a estudiar la migración humana internacional y la integración de los migrantes en la sociedad de acogida. Los estudios empíricos se pueden leer de forma independiente ya que cada capítulo aborda una pregunta de investigación, contiene una revisión de literatura específica, metodología, resultados empíricos, conclusiones y discusión de los resultados. Como resumen: primero, esta tesis estima los efectos conjuntos de los stocks preexistentes de distancia migrante y ancestral para predecir los flujos migratorios. En segundo lugar, estudia a los hijos de migrantes en los Estados Unidos de América, su desempeño en la escuela secundaria en comparación con los hijos de nativos, y el papel de las aspiraciones y expectativas educativas como factores determinantes de su desempeño educativo. En tercer lugar, examina a los estudiantes internacionales y el papel de la ayuda financiera en la finalización exitosa de la educación superior en el extranjero utilizando datos del programa de becas / préstamos de Colfuturo.