CCDM Model with Spatial Curvature and The Breaking of "Dark Degeneracy"

Creation of Cold Dark Matter (CCDM), in the context of Einstein Field Equations, leads to a negative creation pressure, which can be used to explain the accelerated expansion of the Universe. Recently, it has been shown that the dynamics of expansion of such models can not be distinguished from the concordance $\Lambda$CDM model, even at higher orders in the evolution of density perturbations, leading at the so called "dark degeneracy". However, depending on the form of the CDM creation rate, the inclusion of spatial curvature leads to a different behavior of CCDM when compared to $\Lambda$CDM, even at background level. With a simple form for the creation rate, namely, $\Gamma\propto\frac{1}{H}$, we show that this model can be distinguished from $\Lambda$CDM, provided the Universe has some amount of spatial curvature. Observationally, however, the current limits on spatial flatness from CMB indicate that neither of the models are significantly favored against the other by current data, at least in the background level.Comment: 13 pages, 5 figure

Bayesian analysis of CCDM Models

Creation of Cold Dark Matter (CCDM), in the context of Einstein Field Equations, leads to negative creation pressure, which can be used to explain the accelerated expansion of the Universe. In this work we tested six different spatially flat models for matter creation using statistical tools, at light of SN Ia data: Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC) and Bayesian Evidence (BE). These approaches allow to compare models considering goodness of fit and number of free parameters, penalizing excess of complexity. We find that JO model is slightly favoured over LJO/$\Lambda$CDM model, however, neither of these, nor $\Gamma=3\alpha H_0$ model can be discarded from the current analysis. Three other scenarios are discarded either from poor fitting, either from excess of free parameters.Comment: 16 pages, 6 figures, 6 tables. Corrected some text and language in new versio

Wind Risk Assessment in Urban Environments: The Case of Falling Trees During Windstorm Events in Lisbon

Trees bring many benefits to the urban environment. However, they may also cause hazards to human population, being the major causes of injuries and infrastructural damage during strong wind events. In the city of Lisbon, strong winds rather frequently result in tree falls, depending on the season and meteorological conditions. This paper presents a methodology to analyse tree damage due to strong wind events in urban environments. Each occurrence has been recorded by the Lisbon Fire Brigade and Rescue Services (Regimento de Sapadores Bombeiros de Lisboa - RSBL). Information provided by RSBL relating to the period of 1990-2005 was considered along with hourly wind speed and direction, species, fitossanitary conditions and urban parameters. To ensure that the fallen trees were caused by strong winds, only days with three or more occurrences of fallen trees were selected. It was found that in summer, northerly winds are responsible for 11% of tree falls, with winds from other directions (west, southwest and south) responsible for 5%. From autumn to spring, perturbed weather conditions originating from the west, southwest and south are responsible for 84% of fallen trees. The majority of tree falls occurred when wind speed surpassed 7 m/s in the six hours prior to their fall. Some recommendations to the Civil Protection Agency and the Fire Department are presented to improve the mission of collecting information. This research is a contribution to the assessment of wind risk in Lisbon

Large cities are less green

We study how urban quality evolves as a result of carbon dioxide emissions as urban agglomerations grow. We employ a bottom-up approach combining two unprecedented microscopic data on population and carbon dioxide emissions in the continental US. We first aggregate settlements that are close to each other into cities using the City Clustering Algorithm (CCA) defining cities beyond the administrative boundaries. Then, we use data on $\rm{CO}_2$ emissions at a fine geographic scale to determine the total emissions of each city. We find a superlinear scaling behavior, expressed by a power-law, between $\rm{CO}_2$ emissions and city population with average allometric exponent $\beta = 1.46$ across all cities in the US. This result suggests that the high productivity of large cities is done at the expense of a proportionally larger amount of emissions compared to small cities. Furthermore, our results are substantially different from those obtained by the standard administrative definition of cities, i.e. Metropolitan Statistical Area (MSA). Specifically, MSAs display isometric scaling emissions and we argue that this discrepancy is due to the overestimation of MSA areas. The results suggest that allometric studies based on administrative boundaries to define cities may suffer from endogeneity bias

Wind risk assessment in urban environments: the case of falling trees during windstorm events in Lisbon

Trees bring many benefits to the urban environment. However, they may also cause hazards to human population, being the major causes of injuries and infrastructural damage during strong wind events. In the city of Lisbon, strong winds rather frequently result in tree falls, depending on the season and meteorological conditions. This paper presents a methodology to analyse tree damage due to strong wind events in urban environments. Each occurrence has been recorded by the Lisbon Fire Brigade and Rescue Services (Regimento de Sapadores Bombeiros de Lisboa - RSBL). Information provided by RSBL relating to the period of 1990-2005 was considered along with hourly wind speed and direction, species, fitossanitary conditions and urban parameters. To ensure that the fallen trees were caused by strong winds, only days with three or more occurrences of fallen trees were selected. It was found that in summer, northerly winds are responsible for 11% of tree falls, with winds from other directions (west, southwest and south) responsible for 5%. From autumn to spring, perturbed weather conditions originating from the west, southwest and south are responsible for 84% of fallen trees. The majority of tree falls occurred when wind speed surpassed 7 m/s in the six hours prior to their fall. Some recommendations to the Civil Protection Agency and the Fire Department are presented to improve the mission of collecting information. This research is a contribution to the assessment of wind risk in Lisbon

The impact of health consciousness on consumers’ purchase intention and the mediating effect of ingredients’ awareness : an analysis on Chocolate

Over the past few years a dramatic move has taken place in the food industry and people become more and more concerned about their own health. Following this trend, retailers are also taking actions, not just by creating areas in the supermarket dedicated to healthy food products but also having, on the same shelf, the healthy option of the same product. This entire study consists on an investigation about if the health consciousness impacts or not the purchase intention, giving a special attention to the role of the ingredients’ awareness, going deep on sugars. The pushback against sugar comes as, in general, consumers have begun to take a greater interest in what makes up their food and diets. The health conscious took umbrage with not only how much sugar was put into processed food, but also how many products included added sugars. The methodology used for this investigation includes both primary and secondary data, encompassing one survey. Results obtained with this study suggest that Purchase Intention is explained by Health Consciousness as well as by the Ingredients’ Awareness. In addition, Ingredients’ Awareness plays a key role in mediating some of these relationships.Ao longo dos últimos anos ocorreu um novo e importante movimento na indústria alimentar, com os consumidores a tornarem-se crescentemente preocupados com a sua saúde. Respondendo a esta tendência, os grandes retalhistas têm vindo a tomar medidas, não só começando a apresentar num mesmo linear as opções standard e mais saudáveis para um mesmo tipo de produto, como inclusivamente criando nas lojas áreas específicas e perfeitamente individualizadas, dedicadas a produtos alimentares saudáveis. Todo este estudo consiste numa investigação sobre se, e em que medida, a consciência da saúde por parte dos consumidores afeta a sua intenção de compra, dando especial relevo ao papel da perceção que os mesmos têm relativamente aos ingredientes, particularmente e com maior profundidade no que respeita aos açúcares. Em geral, a repulsa pelo açúcar decorre, da crescente atenção dos consumidores relativamente à composição dos seus alimentos e dietas. A consciência da saúde surge assim em consonância não só com o teor de açúcar adicionado aos alimentos processados, mas também com a quantidade de produtos aos quais foram adicionados açúcares. A metodologia utilizada para esta investigação inclui dados primários e secundários, envolvendo um questionário. Os resultados obtidos com este estudo sugerem que a Intenção de Compra é explicada pela Consciência da Saúde, bem como pela Perceção dos Ingredientes, desempenhando esta um papel chave na mediação de algumas dessas relações

Transtornos mentais e do comportamento relacionados ao trabalho em médicos anestesiologistas

ResumoJustificativaa anestesiologia é uma especialidade cuja especificidade do processo de trabalho torna elevados níveis de estresse uma condição inevitável, situação preocupante no cotidiano desses profissionais.Objetivoso presente estudo, fundamentado em dados da literatura nacional e internacional, tem o propósito de discutir as bases da ocorrência de transtornos mentais e de comportamento ou agravos psicopatológicos (sofrimento psíquico) relacionados à atividade laboral em médicos anestesiologistas.Métodofez‐se uma revisão de literatura em que foram selecionados artigos científicos nas bases de dados Medline e Lilacs, publicados entre 2000 e 2012, em português, inglês e espanhol, que abordam a possível associação entre riscos ocupacionais da profissão de médico anestesiologista e problemas de saúde mental e sofrimento psíquico. Foram enumeradas 26 publicações.Resultadosvários aspectos do trabalho do médico anestesiologista apresentam‐se como pontos importantes para a compreensão das relações entre saúde mental no trabalho e organização do trabalho. Podem ser destacados como adoecedores a má estruturação temporal do trabalho, as relações interpessoais conflituosas e o mau controle sobre a própria atividade.Conclusãoa organização do trabalho, quando não adequada, é um importante fator de risco ocupacional para a vida e a saúde mental dos trabalhadores, principalmente, dos profissionais voltados para o cuidado de pessoas. O foco presente são os médicos anestesiologistas, constantemente expostos a fatores estressantes e ansiogênicos.AbstractBackgroundAnaesthesiology is a specialty whose specificity of the working process results in high levels of stress as an inevitable condition – a particularly worrying situation in the daily life of these professionals.ObjectivesThis study, based on data from national and international literature, aims to discuss the basis of the occurrence of mental and behavioural disorders or of psychopathological injuries (psychological distress) related to working activity in anesthesiologists.MethodA literature review was conducted, with papers selected from Medline and Lilacs databases, published between 2000 and 2012 in Portuguese, English and Spanish, and addressing the possible association between occupational hazards of the anaesthesiologist profession and mental health problems and psychic distress. Twenty‐six publications were listed.ResultsSeveral aspects of the anesthesiologist's work are important points to better understand the relationship between mental health at work and working organization. Poor temporal structuring of work, conflictuous interpersonal relationships and poor control over the activity itself may be mentioned as illness enhancers.ConclusionThe working organization, when not appropriate, is an important occupational risk factor for the life and mental health of workers, mainly of professionals focused on the care of people. This paper focuses on anesthesiologists, who are constantly exposed to stressful and anxiogenic factors

A worldwide model for boundaries of urban settlements

The shape of urban settlements plays a fundamental role in their sustainable planning. Properly defining the boundaries of cities is challenging and remains an open problem in the Science of Cities. Here, we propose a worldwide model to define urban settlements beyond their administrative boundaries through a bottom-up approach that takes into account geographical biases intrinsically associated with most societies around the world, and reflected in their different regional growing dynamics. The generality of the model allows to study the scaling laws of cities at all geographical levels: countries, continents, and the entire world. Our definition of cities is robust and holds to one of the most famous results in Social Sciences: Zipf's law. According to our results, the largest cities in the world are not in line with what was recently reported by the United Nations. For example, we find that the largest city in the world is an agglomeration of several small settlements close to each other, connecting three large settlements: Alexandria, Cairo, and Luxor. Our definition of cities opens the doors to the study of the economy of cities in a systematic way independently of arbitrary definitions that employ administrative boundaries