Size and shape of Mott regions for fermionic atoms in a two-dimensional optical lattice

We investigate the harmonic-trap control of size and shape of Mott regions in the Fermi Hubbard model on a square optical lattice. The use of Lanczos diagonalization on clusters with twisted boundary conditions, followed by an average over 50-80 samples, drastically reduce finite-size effects in some ground state properties; calculations in the grand canonical ensemble together with a local-density approximation (LDA) allow us to simulate the radial density distribution. We have found that as the trap closes, the atomic cloud goes from a metallic state, to a Mott core, and to a Mott ring; the coverage of Mott atoms reaches a maximum at the core-ring transition. A `phase diagram' in terms of an effective density and the on-site repulsion is proposed, as a guide to maximize the Mott coverage. We also predict that the usual experimentally accessible quantities, the global compressibility and the average double occupancy (rather, its density derivative) display detectable signatures of the core-ring transition. Some spin correlation functions are also calculated, and predict the existence N\'eel ordering within Mott cores and rings.Comment: 5 pages, 6 figure

A representação literária do jornal no universo romanesco barretiano

Dissertação (mestrado)—Universidade de Brasília, Instituto de Letras, Departamento de Teoria Literária e Literaturas, 2007.O presente trabalho pretende estudar a representação literária da imprensa nos romances de Lima Barreto. A partir das obras Recordações do Escrivão Isaías Caminha, Triste Fim de Policarpo Quaresma, Numa e a Ninfa, Vida e Morte de M. J.Gonzaga de Sá e Clara dos Anjos, selecionam-se aspectos jornalísticos e literários presentes para descrever e analisar as relações entre jornalismo e literatura nestes romances, a fim de questionar esta confluência e apontar a articulação textual destas relações no texto barretiano. No capítulo inicial, o autor situa a trajetória de repórter e cronista e o trabalho literário de Lima Barreto na história da imprensa brasileira. Na seqüência, aborda a influência da militância no jornalismo sobre o estilo e projeto literário deste escritor. No capítulo seguinte, examina o posicionamento de Lima Barreto sobre a imprensa de sua época e as contradições apontadas por ele nesta instituição. Nos capítulos quatro e cinco, o autor analisa, respectivamente, a galeria de personagens jornalistas e o papel da imprensa nos enredos do universo romanesco barretiano

Religiosity and optimism in ill and healthy elderly

Introducción: Teniendo en cuenta el análisis de la función de la religiosidad y su impacto en la salud, los comportamientos de riesgo, y el bienestar como un clásico, la investigación sobre el impacto de la religiosidad en el optimismo en los ancianos se ha descuidado. De hecho, la religiosidad en el proceso de envejecimiento se ha demostrado que se asocia con beneficios importantes. Objetivos: En este trabajo se pretende analizar los factores de la religiosidad en el optimismo y la mediación de la satisfacción con la vida en ancianos sanos y enfermos. Método: La muestra de encuestados que consta de 250 ancianos clasificados como sanos (M = 74,87, DP = 6,77 años) y 244 enfermos de edad avanzada (M = 68,92; DP = 10,35 años). Todos los participantes respondieron al cuestionario CRSV (Mónico, 2010). Conclusiones: Se encontró una relación positiva entre la religiosidad y el optimismo sólo para el grupo de ancianos sanos. El optimismo para ancianos enfermos fue promovido solamente de manera significativa por la satisfacción con la vida. La distinción entre interioridad y exterioridad del optimismo, se ha demostrado que en ancianos sanos su optimismo se basa en las creencias de interioridad , mientras que los pacientes de edad avanzada enfermos basan su optimismo en factores externos. El establecimiento de un sistema de autorregulación en los ancianos se discute con las creencias y prácticas religiosas como perpetradores.Introduction: Considering the analysis of the roles of religiosity and its impact on health, risk behaviors, and well-being as classic, research about the impact of religiosity on optimism in the elderly has been neglected. Indeed, in the ageing process religiosity has been shown to be associated with important benefits. Aims: In this paper we seek to analyze the agency factors of religiosity in optimism and the mediation by satisfaction with life in healthy and ill elderly. Method: The surveyed sample consisting of 250 elderly classified as healthy (M = 74.87, DP = 6.77 years old) and 244 ill elderly (M = 68.92; DP = 10.35 years old). All the participants answered to the CRSV Questionnaire (Mónico, 2010). Conclusions: We found a positive relationship between religiosity and optimism only for the group of healthy elderly. For ill elderly optimism was only significantly promoted by satisfaction with life. The distinction between internality and externality optimism has shown that healthy elderly anchor their optimism in internality beliefs, while elderly patients base their optimism on external factors. The establishment of a self-regulating system in elderly is discussed with beliefs and religious practices as perpetuators.peerReviewe

The effect of the vehicle registration tax in the sales of new passenger cars in Portugal

The purpose of this dissertation is to understand how the ISV (Imposto Sobre Veículos) has been impacting the sales of new passenger cars in the Portuguese market, through the estimation of fixed effect models. There is an overview on how the fixed models work and its main features, there is also a summary about the ISV, how is calculated and the changes made by the Portuguese Government throughout the years. The main findings of this dissertation are that the effect of the ISV has not been constant, the first semester of the year has a stronger positive impact in the sales of new passenger cars and there is a positive sales anticipation effect with a size between 0.2% and 0.4%

Probing Radiosensitisers in Electron Transfer Experiments

The impact of ionising radiation in the living systems is being investigated for decades, because its capability to induce damage in tissues and cells, compromising the DNA molecule integrity, resulting in mutations and eventually cells death. Considering this, ionising radiation can be very useful in different fields, especially in radiation therapy. However, it is necessary to guarantee that the effects of radiation in normal tissues during a radiation treatment are minimised. Many efforts have been made to improve the radiotherapy protocols, namely by the application of radiosensitisers which enhance the effect of radiation. Recent research investigations have demonstrated the role of secondary low-energy electrons as the main damaging agents in DNA. These secondary electrons can interact directly or indirectly with molecules, producing highly reactive species (ions and radicals). Moreover, it is also known that electrons do not exist freely in the physiological medium, but rather in solvated and/or in pre-solvated states. Therefore, studies on electron transfer between atoms/ions and biomolecules seems crucial to better understand the molecular mechanism of radiation interaction. The work presented in this thesis consists on the study of electron transfer collisions of atoms/ions in molecules of biological relevance. Initially, neutral potassium collisions in imidazole, nitroimidazoles (4-nitroimidazole and 2-nitroimidazole) and methylated compounds (1-methyl-4-nitroimidazole and 1-methyl-5-nitroimidazole) were investigated by time-of-flight (TOF) mass spectrometry in a crossed beam experiment comprising a neutral potassium beam and a molecular effusive beam. In these experiments the anionic fragmentation patterns and yields were obtained. These results present some differences from the dissociative electron attachment (free electrons) results, highlighting the importance of charge transfer studies in understanding the molecular reactions upon radiation. The second part of the work was performed in a novel crossed beam setup where collisions between oxygen anions and molecules as nitrogen, water and pyridine were investigated by measuring positive and negative fragmentation patterns through TOF mass spectrometry. From these studies we obtained for the first time experimental electron detachment cross-section of O2− in water and pyridine

Validation of automatic similarity measures

Tese de mestrado em Bioinformática e Biologia Computacional, Universidade de Lisboa, Faculdade de Ciências, 2020A capacidade para comparar automaticamente duas entidades biomédicas (p. ex. doenças, vias metabólicas ou artigos científicos) permite que os computadores raciocinem sobre o conhecimento científico. Assim sendo, fazer a validação destas medidas é essencial para garantir que os resultados produzidos por elas reflictam o actual conhecimento colectivo sobre o respectivo domínio. Uma das estratégias para avaliar se a medida é precisa e funcional é a validação manual por parte de peritos. Contudo, este processo é ineficiente devido a toda a pesquisa secundária necessária para o fazer, o que significa que compilar grandes conjuntos de dados de valores de semelhança atribuídos por humanos é uma tarefa difícil. “Manual Validation Helper Tool” (MVHT) é uma aplicação web criada com o intuito de acelerar esta validação manual, em conjunto com um formato capaz de acomodar os diversos tipos de dados em forma de anotações, provenientes de diferentes ontologias ou domínios. MVHT foi testada em quatro datasets distintos e um deles foi apresentado a utilizadores piloto para que dessem o seu feedback acerca do que poderia ser melhorado na aplicação, bem como para se obter um gold-standard de semelhança manual. Com o seu auxílio, a ferramenta foi optimizada e encontra-se acessível para ser usada por criadores de medidas de semelhança semântica, que por sua vez podem partilhar os seus datasets de forma prática, os quais peritos podem visitar e rapidamente começar a comparar pares de entidades.The ability to automatically compare two biomedical entities (e.g. diseases, biochemical pathways, papers) enables the use of computers to reason over scientific knowledge. As such, validating these measures is essential to ensure that the results they produce reflect the current community knowledge on the respective domain. Manual validation by experts is one of the strategies to assess whether a measure is sound and accurate. However, this is an inefficient process because of the secondary research required to do so, which means that compiling large datasets of human-curated similarity values is difficult. The “Manual Validation Helper Tool” (MVHT) is a web application created to accelerate this manual validation, coupled to a format that can accommodate different types of data in the form of annotations, from different domains or ontologies. MVHT was tested on four distinct datasets and one of them was given to pilot users so they could provide feedback on the application, as well as to gather a gold-standard of manual similarity. With their help the tool was optimized and is accessible to be used by creators of semantic similarity measures, who can share their datasets in a more practical way via generated URLs, which other people can visit and quickly start comparing pairs of entities

Religiosity and optimism in ill and healthy elderly

Introducción: Teniendo en cuenta el análisis de la función de la religiosidad y su impacto en la salud, los comportamientos de riesgo, y el bienestar como un clásico, la investigación sobre el impacto de la religiosidad en el optimismo en los ancianos se ha descuidado. De hecho, la religiosidad en el proceso de envejecimiento se ha demostrado que se asocia con beneficios importantes. Objetivos: En este trabajo se pretende analizar los factores de la religiosidad en el optimismo y la mediación de la satisfacción con la vida en ancianos sanos y enfermos. Método: La muestra de encuestados que consta de 250 ancianos clasificados como sanos (M = 74,87, DP = 6,77 años) y 244 enfermos de edad avanzada (M = 68,92; DP = 10,35 años). Todos los participantes respondieron al cuestionario CRSV (Mónico, 2010). Conclusiones: Se encontró una relación positiva entre la religiosidad y el optimismo sólo para el grupo de ancianos sanos. El optimismo para ancianos enfermos fue promovido solamente de manera significativa por la satisfacción con la vida. La distinción entre interioridad y exterioridad del optimismo, se ha demostrado que en ancianos sanos su optimismo se basa en las creencias de interioridad , mientras que los pacientes de edad avanzada enfermos basan su optimismo en factores externos. El establecimiento de un sistema de autorregulación en los ancianos se discute con las creencias y prácticas religiosas como perpetradores.Introduction: Considering the analysis of the roles of religiosity and its impact on health, risk behaviors, and well-being as classic, research about the impact of religiosity on optimism in the elderly has been neglected. Indeed, in the ageing process religiosity has been shown to be associated with important benefits. Aims: In this paper we seek to analyze the agency factors of religiosity in optimism and the mediation by satisfaction with life in healthy and ill elderly. Method: The surveyed sample consisting of 250 elderly classified as healthy (M = 74.87, DP = 6.77 years old) and 244 ill elderly (M = 68.92; DP = 10.35 years old). All the participants answered to the CRSV Questionnaire (Mónico, 2010). Conclusions: We found a positive relationship between religiosity and optimism only for the group of healthy elderly. For ill elderly optimism was only significantly promoted by satisfaction with life. The distinction between internality and externality optimism has shown that healthy elderly anchor their optimism in internality beliefs, while elderly patients base their optimism on external factors. The establishment of a self-regulating system in elderly is discussed with beliefs and religious practices as perpetuators.peerReviewe

Scaling laws in the dynamics of crime growth rate

The increasing number of crimes in areas with large concentrations of people have made cities one of the main sources of violence. Understanding characteristics of how crime rate expands and its relations with the cities size goes beyond an academic question, being a central issue for contemporary society. Here, we characterize and analyze quantitative aspects of murders in the period from 1980 to 2009 in Brazilian cities. We find that the distribution of the annual, biannual and triannual logarithmic homicide growth rates exhibit the same functional form for distinct scales, that is, a scale invariant behavior. We also identify asymptotic power-law decay relations between the standard deviations of these three growth rates and the initial size. Further, we discuss similarities with complex organizations.Comment: Accepted for publication in Physica

Política alimentar brasileira: fome e obesidade, uma história de carências = Brazilian food policy: hunger and obesity, a history of deprivation

O presente artigo tem como foco o fato de como as políticas sociais vêm atentando, no Brasil, à questão da alimentação. Assim, este artigo pretende analisar a questão da fome, da desnutrição e da obesidade da população brasileira. Historicamente, a luta contra a fome tem sido uma preocupação central e, paradoxalmente, a obesidade atinge índices de epidemia. Ao longo do período brasileiro, ocorreram lutas em torno da fome e, em resposta, foram apresentados planos e ações governamentais, ainda não satisfatórios; a questão ampliou-se da fome à obesidade e hoje se sugere que os debates do Estado brasileiro precisam considerar o caráter especial da política pública: o seu propósito emancipatório. Neste contexto, o Serviço Social tem o compromisso de abordar esta realidade, lançando um olhar para a totalidade do fenômeno, desvendando e compreendendo as contradições inerentes à fome e obesidad