Abstract: The world is facing a global refugee crisis where people are being forced to flee their countries mostly due to violence and poverty; crossing borders to new nations hoping to find not only a new life and stability but also peace without losing their identity. In Venezuela, the Refugee crisis was established as a crisis, until 2019, that is why in the same report, the country does not appear in the ranking of countries with the most international displacement. Venezuela would be the country with the second most international forced displacement, where more than 4 million Venezuelans have fled around the world in the past 5 years. 1.3 million of these refugees have been received by Colombia’s government in the past two. Colombia - both its government and its people - has been very open to receiving Venezuelan refugees and it has been able to find ways to provide them the best options and conditions for them to either stay in a temporary or in a permanent way, but the situation is challenging. But the rapidly increasing flows of immigrants crossing the border, the unexpected numbers of groups of people arriving in Colombia, and the problems Colombia on its own is facing (high unemployment and poverty rates to name a few) are fundamental for this crisis to be even more difficult to solve. It was difficult to find solutions in Colombia even before Venezuela’s crisis, today a state of emergency has been declared in most cities across the 2,300 kilometers of shared borders. Inspired and influenced by this crisis, this Capstone project aims to create a local solution to Venezuela’s refugee crisis in Colombia; one, that can be replicated in all places that are going through the same or similar circumstances. What development tools can be used or included in these specific communities as part of the solution? How can we transform this crisis into an opportunity for both Colombian communities and Venezuelan refugees? This study is focused on implementing circular economies recommendations in temporal shelters for Venezuelan refugees in Colombia. Specifically, shelters that are supervised by Carminates Tricolor a Colombian/Venezuelan nonprofit. Taking into account that there are various routes and multiple organizations involved, the project will start by creating recommendations to the temporal and local shelters located in the section between Cucuta and Bucaramanga, one of the most dangerous routes that the walkers cross to get to their final destinations.

Resumen: El estudio de las maternidades no heteronormativas viene ampliando el concepto de familia hacia una comprensión que se acerca cada vez más a los aspectos sociales del parentesco y la crianza. El objetivo de este trabajo es mostrar los patrones y las discontinuidades que aparecen en las narrativas de un grupo de mujeres lesbianas, bisexuales, -o que se salen de la heteronorma- en la configuración de sus proyectos de maternidad. Parto del análisis de sus narrativas para señalar que la reproducción asistida es un lugar de disputa, pues: i) apuesta por una construcción colectiva del parentesco por medio del diálogo y las conversaciones, ii) se presenta como un desafío al modelo de parentesco basado en lazos genéticos, iii) abre caminos para formas creativas de familia, maternidad y crianza más allá de los determinismos y mandatos sexo-genéricos, iv) fomenta prácticas de resistencia y agencia contra la discriminación y violencia del heteropatriarcado, y al mismo tiempo v) es un campo atravesado por cuestiones de clase y raza que demarca categorías de mujeres por las formas en las que acceden y se relacionan con la maternidad en el contexto catalán.

Abstract: This paper studies the potential drivers of governments’ approval rates in 18 Latin American countries using Internet search query data from Google Trends and traditional data sources. It employs monthly panel data between January 2006 and December 2015. The analysis tests several specifications including traditional explanatory variables of governments’ approval rates – i.e. inflation, unemployment rate, GDP growth, output gap – and subjective explanatory variables – e.g. perception of corruption and insecurity. For the latter, it uses Internet search query data to proxy citizens’ main social concerns, which are expected to drive governments’ approval rates. The results show that the perception of corruption and insecurity, and complaints about public services have a statistically significant association with governments’ approval rates. This paper also discusses the potential of Internet search query data as a tool for policy makers to understand better citizens’ perceptions, since it provides highly anonymous and high-frequency series in real-time.

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.

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.

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.

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.

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: 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: 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.