Urban Sprawl and Sustainable Urban Policies. A Review of the Cases of Lima, Mexico City and Santiago de Chile

In recent decades, urban processes have experienced deep transformations. One of them has been the growing importance of urban sprawl. This article reviews its main features and the policies related to the paradigm of sustainability in three Latin American Megalopolises: Mexico City, Lima, and Santiago de Chile. For this purpose, we have carried out an extensive compilation of the existing academic literature. Urban sprawl in those cities cannot be understood without considering the rising housing needs of popular classes, usually addressed through the sequence settlement-parceling-building-urbanization. Simultaneously high-income groups tend to create separated and gated commodities and there is increasing spatial mobility of the middle classes. Those processes tend to generate highly segregated and increasingly patched metropolitan areas. Sustainability is framed on models of urban governance based on ecological modernization. In this context, three main sustainable policies are analyzed: water supply, green areas provision, and transport. Conclusions stress: (1) Deep changes experienced and the path-dependent element observed in the social construction of sustainability (2) Consolidation of a model of socially segregated and ecologically differentiated urban polycentrism (3) Relevance of the different megalopolises as niches of experimentation and innovation in the construction of specific forms of sustainable transition

Causal hierarchy of multipartite Bell nonlocality

As with entanglement, different forms of Bell nonlocality arise in the multipartite scenario. These can be defined in terms of relaxations of the causal assumptions in local hidden-variable theories. However, a characterisation of all the forms of multipartite nonlocality has until now been out of reach, mainly due to the complexity of generic multipartite causal models. Here, we employ the formalism of Bayesian networks to reveal connections among different causal structures that make a both practical and physically meaningful classification possible. Our framework holds for arbitrarily many parties. We apply it to study the tripartite scenario in detail, where we fully characterize all the nonlocality classes. Remarkably, we identify new highly nonlocal causal structures that cannot reproduce all quantum correlations. This shows, to our knowledge, the strongest form of quantum multipartite nonlocality known to date. Finally, as a by-product result, we derive a non-trivial Bell-type inequality with no quantum violation. Our findings constitute a significant step forward in the understanding of multipartite Bell nonlocality and open several venues for future research.Comment: 6 pages + appendix, 3 figures, 3 tables. Minor errors corrected, discovery of strongest form of quantum multipartite non-locality known so far added. v3: text improved. v4: Accepted by Quantu

2022-7 Market Power, Taxation and Product Variety in the Brazilian Automobile Industry

This paper empirically assesses the impact of a discontinuous tax schedule on prices, markups and product assortment in the Brazilian automobile industry. To this end, I estimate a structural, equilibrium model of demand and supply for over a hundred different models and engine sizes of automobiles. With the model estimates of price elasticities and marginal costs I quantify how market power impacts the progressivity of the discontinuous tax schedule. I also examine how firms would reposition their products to avoid the tax and quantify the impact of this repositioning on equilibrium outcomes

Stability of 2pi domain walls in ferromagnetic nanorings

The stability of 2pi domain walls in ferromagnetic nanorings is investigated via calculation of the minimum energy path that separates a 2pi domain wall from the vortex state of a ferromagnetic nanoring. Trapped domains are stable when they exist between certain types of transverse domain walls, i.e., walls in which the edge defects on the same side of the magnetic strip have equal sign and thus repel. Here the energy barriers between these configurations and vortex magnetization states are obtained using the string method. Due to the geometry of a ring, two types of 2pi walls must be distinguished that differ by their overall topological index and exchange energy. The minimum energy path corresponds to the expulsion of a vortex. The energy barrier for annihilation of a 2pi wall is compared to the activation energy for transitions between the two ring vortex states.Comment: 4 pages, 2 figure

Probing dark matter with higgs bosons and top quarks

Dissertação de mestrado em PhysicsThe Dark Matter (DM) mystery, or, also called, the missing matter problem, is probably the most important astrophysical and cosmological problem to be solved in order to explain numerous phenomena that our current best theories of gravity fail to describe. These observations, gathered for the last century, imply the existence of extra matter in the Universe, to which we called dark matter, due to its non-interactive nature with the Standard Model (SM) interactions like the Electromagnetic (EM) force, making it extremely hard to detect. Although its existence is generally accepted, some astrophysicists argue for various modifi cations of the laws of general relativity, such as modified Newtonian dynamics, tensor-vector-scalar gravity, entropic gravity and some others. These models attempt to account for all observations without invoking supplemental matter. DM is thought to have had a strong influence on the structure and evolution of the Universe and to be non-baryonic, meaning it may be composed of some particles yet to be discovered, which constitutes another evidence supporting the incompleteness of the SM. A phenomenological study is presented in this thesis in which a simplified DM model was used in order to perform the reconstruction of the ¯ system in the presence of a scalar dark matter particle, 0. In order to do this, signal samples of → ¯ 0 were generated at Leading Order (LO) using MadGraph5_aMC@NLO at the Large Hadron Collider (LHC), considering a pure CP-odd scalar boson, with a mass of 0 = 0 GeV, and considering only the dileptonic final states of the top quark pair. An event analysis is described and applied to signal samples and background SM events, which are reconstructed using a kinematic fit, assuming all the contributions for the missing transverse energy belong only to the undetected neutrinos. Furthermore, CP angular observables, that were explored in the studies of the Higgs boson, were used to set Confidence Levels (CL) limits as a function of the CP nature of the top quark couplings to the proposed scalar particle 0. Of these observables, the Δℓ +ℓ − and 4 variables were used to calculate exclusion limits for the CP-even and CP-odd components of the top quark DM couplings.O mistério da matéria escura é possivelmente o problema astrofísico e cosmológico mais significativo a ser resolvido pela comunidade científica a fim de explicar vários fenómenos que as melhores teorias da gravidade dos dias de hoje falham em descrever. As observações astronómicas realizadas no último século, implicam a existência de matéria extra no Universo, à qual chamamos matéria escura, devido à sua natureza não interactuante com as interações do Modelo Padrão, como é o caso da força eletromag nética, tornando a sua deteção particularmente difícil. Embora a sua existência seja geralmente aceite, existem modelos alternativos que envolvem possíveis alterações nas leis da relatividade geral, tais como a dinâmica modificada de Newton, gravidade tensorial-vetorial-escalar, gravidade entrópica, entre outras. Estes modelos tentam explicar todas as observações sem invocar matéria suplementar. Pensa-se que a matéria escura tenha tido uma forte influência na estrutura e evolução do Universo e de ser não-bariónica, ou seja, constituída por partículas que estão ainda por descobrir, dando assim mais uma indicação de que o Modelo Padrão está de facto incompleto. Nesta dissertação é apresentado um estudo fenomenológico no qual foi utilizado um modelo de ma téria escura simplificado que considera a produção de um sistema ¯ associado a uma partícula escalar de matéria escura, 0. Para este objetivo, amostras de sinal do tipo → ¯ 0 foram geradas à ordem mais baixa (LO) usando o gerador Monte Carlo MadGraph5_aMC@NLO no LHC (Large Hadron Collider), considerando um bosão puramente CP-ímpar, com uma massa de 0 = 0 GeV, e considerando apenas estados finais dileptónicos. A análise descrita foi efetuada nestas amostras de sinal em conjunto com eventos de fundo do Modelo Padrão e estes foram reconstruídos com recurso a um ajuste cinemático, assumindo que toda a energia transversa em falta pertence aos neutrinos, provenientes dos decaimentos do quark top e que não são detetados. Para além disto, observáveis angulares, que foram explorados an teriormente em estudos do bosão de Higgs, foram usados para definir limites nos níveis de confiança com que se detetam estas partículas em função da natureza CP dos acoplamentos do quark top à partícula proposta 0. Destes observáveis, houve um particular foco na diferença do ângulo azimutal dos dois lep tões presentes nos eventos (Δℓ +ℓ −) e na variável 4 para calcular limites de exclusão aos acoplamentos do quark top ao mediador de matéria escura

2021-6 The Inner Workings of a Hub-and-Spoke Cartel in the Automotive Fuel Industry

We analyze a hub-and-spoke cartel in the Brazilian automotivefuel industry. Using the court documents and detailed data on the supply chain we uncover three mechanisms beyond information sharing used by wholesalers (hub) to help retailers (spokes) solve the obstacles of price coordination: vertical transfers across asymmetric spokes; subsidies during punishment; and cost stabilization. We argue that wholesalers benefited from the cartel by being the exclusive supplier during the scheme. We use the synthetic control approach to quantify how successful the cartel was in increasing markups. We find that not only retailers, but wholesalers benefited from the cartel

Chandra Observation of the Edge-on Galaxy NGC 3556 (M 108): Violent Galactic Disk-halo Interaction Revealed

We present a 60 ks Chandra ACIS-S observation of the isolated edge-on spiral NGC 3556, together with a multiwavelength analysis of various discrete X-ray sources and diffuse X-ray features. Among 33 discrete X-ray sources detected within the I_B = 25 mag per square arcsec isophote ellipse of the galaxy, we identify a candidate for the galactic nucleus, an ultraluminous X-ray source that might be an accreting intermediate-mass black hole, a possible X-ray binary with a radio counterpart, and two radio-bright giant HII regions. We detect large amounts of extraplanar diffuse X-ray emission, which extends about 10 kpc radially in the disk and >~ 4 kpc away from the galactic plane. The diffuse X-ray emission exhibits significant substructures, possibly representing various blown-out superbubbles or chimneys of hot gas heated in massive star forming regions. This X-ray-emitting gas has temperatures in the range of ~ 2-7 x 10^6 K and has a total cooling rate of ~ 2 x 10^40 erg/s. The energy can be easily supplied by supernova blast-waves in the galaxy. These results demonstrate NGC 3556 as being a galaxy undergoing vigorous disk-halo interaction. The halo in NGC 3556 is considerably less extended, however, than that of NGC 4631, in spite of many similarities between the two galaxies. This may be due to the fact that NGC 3556 is isolated whereas NGC 4631 is interacting. Thus NGC 3556 presents a more pristine environment for studying the disk-halo interaction.Comment: 30 pages, 12 figures. To appear in ApJ. Please see http://www.astro.umass.edu/~wqd/papers/n3556/n3556.pdf for a high resolution versio

La Constitución Política de 1991, el Estado social de derecho y la salud: una relación compleja

El capítulo parte por ubicar el contexto social y político en el que se enmarca el cambio constitucional de 1991 en Colombia, asimismo, sus antecedentes jurídicos-políticos, a fin de dar cuenta de las diversas estrategias utilizadas para su aprobación y desarrollo. Seguidamente, nos ocupamos de las discusiones que al interior de la ANC se dan sobre la salud, y la forma bajo la cual se configuran las políticas sociales bajo la nueva forma de Estado Social de Derecho, para presentar finalmente algunos elementos de discusión

Bibliothèque de Blonay-St-Légier: vers une bibliothèque troisième lieu

Ce travail de Bachelor a été réalisé sur mandat de la Bibliothèque publique et scolaire de Blonay - St-Légier. Ce mandat consistait à proposer un projet de réagencement s’inspirant du concept de troisième lieu en bibliothèque. La Bibliothèque de Blonay - St- Légier souhaitait par ce biais fidéliser les usagers et les inciter à prolonger leurs visites en bibliothèque. Il fallait, dans la même optique, proposer trois projets d’actions. Ceuxci devaient initier de nouvelles activités, de telle façon que les usagers continuent à les pratiquer en bibliothèque, une fois l’action terminée. Enfin, le mandat prévoyait la réalisation d’un dossier de vulgarisation sur le concept de troisième en bibliothèque, ainsi que d’un support de présentation, permettant à la bibliothèque d’exposer de manière claire et synthétique son projet à ses partenaires et son autorité de tutelle. La première partie du travail tente de cerner les caractéristiques d’une bibliothèque troisième lieu à travers une revue de la littérature professionnelle. Elle met également en évidence les atouts et les insuffisances de la bibliothèque de Blonay - St-Légier dans une optique de troisième lieu. La seconde partie contient le projet de réaménagement et les différentes propositions d’action, celles qui ont été retenues, comme celles qui ont été refusées. Cette partie intègre aussi une description de la méthode et du cheminement intellectuel qui ont conduit à ces résultats. Le dossier de vulgarisation et son support sont en annexes