A Random Walk down Main Street

US suburbs have often been characterized by their relatively low walk accessibility compared to more urban environments, and US urban environments have been characterized by low walk accessibility compared to cities in other countries. Lower overall density in the suburbs implies that activities, if spread out, would have a greater distance between them. But why should activities be spread out instead of developed contiguously? This brief research note builds a positive model for the emergence of contiguous development along “Main Street” to illustrate the trade-offs that result in the built environment we observe. It then suggests some policy interventions to place a “thumb on the scale” to choose which parcels will develop in which sequence to achieve socially preferred outcomes.

Large Eddy Simulations applied to wind loading and pollutant dispersion

The application of Computational Fluid Dynamics based on the Reynolds-Averaged Navier-Stokes equations to the simulation of bluff body aerodynamics has been thoroughly investigated in the past. Although a satisfactory accuracy can be obtained for some urban physics problems their predictive capability is limited to the mean flow properties, while the ability to accurately predict turbulent fluctuations is recognized to be of fundamental importance when dealing with wind loading and pollution dispersion problems. The need to correctly take into account the flow dynamics when such problems are faced has led researchers to move towards scale-resolving turbulence models such as Large Eddy Simulations (LES). The development and assessment of LES as a tool for the analysis of these problems is nowadays an active research field and represents a demanding engineering challenge. This research work has two objectives. The first one is focused on wind loads assessment and aims to study the capabilities of LES in reproducing wind load effects in terms of internal forces on structural members. This differs from the majority of the existing research, where performance of LES is evaluated only in terms of surface pressures, and is done with a view of adopting LES as a complementary design tools alongside wind tunnel tests. The second objective is the study of LES capabilities in calculating pollutant dispersion in the built environment. The validation of LES in this field is considered to be of the utmost importance in order to conceive healthier and more sustainable cities. In order to validate the numerical setup adopted, a systematic comparison between numerical and experimental data is performed. The obtained results are intended to be used in the drafting of best practice guidelines for the application of LES in the urban physics field with a particular attention to wind load assessment and pollution dispersion problems.

Dendrochronological study of the avalanche path Canal del Roc Roig: first results of the ALUDEX Project in the Pyrenees

Historical data about ancient avalanches are scarce in the Pyrenees. Dendrochronology can provide new data about past avalanches and their return period, but up to now little research has been carried out with this purpose. The Aludex project aims to obtain information about the frequency and extent of extreme avalanches, using a dendrochronological and a nivo-meteorological approach. In this paper, we present the results of a dendrochronological study of the Canal del Roc Roig avalanche path which was affected by two extreme avalanches in February 1996. This first dendrochronological study has permitted us to assess the tree-ring signals due to avalanche events in 53 out of 132 dated trees. The trees presented a variety of responses to the 1996 avalanche events. It is shown that the type of tree-ring signal depends on tree age. The methodology has proved successful in detecting the 1996 and 1972 documented avalanche events, and provided outstanding evidence of undocumented past events such as one in 1930.

Return Migration in the Ecuadorian and Bolivian population: motivations, strategies and discourses

This article analyses the motivations for return migration among the Ecuadorians and Bolivians who, after living in Spain, returned to their countries of origin during the economic crisis that started in 2008. From the analysis of 22 interviews in-depth which took place in Ecuador and 38 in Bolivia to women, men and young people from migrant families, this decision-making process is shown to be embedded into a gendered dynamics of relationships. Particular detail is given to affective and economic elements that had an influence on the decision to return, as well as to the strategies deployed to project their readjustment back in origin. Males and females occupy differential positions within the family, work and social circle, their expectations being built in a gendered manner. Despite the fact migration has brought women greater economic power within the family group, their reintegration upon return redefines their role as main managers in the household and the dynamics that allow their social reproduction. Men, for their part, aspire to refresh their role as providers in spite of their frail labour position upon return. Social mobility for females is passed on through generations by a strong investment on education for their daughters and sons, while for males this mobility revolves around setting up family businesses and around their demonstrative abilities.

Looking for Determinants of Ontological Security in the Spain of the Crisis

The concept of ontological security has a remarkable echo in the current sociology to describe emotional status of men of late modernity. However, the concept created by Giddens in the eighties has been little used in empirical research covering various sources of risk or uncertainty. In this paper, a scale for ontological security is proposed. To do this, we start from the results of a research focused on the relationship between risk, uncertainty and vulnerability in the context of the economic crisis in Spain. These results were produced through nine focus groups and a telephone survey with standardized questionnaire applied to a national sample of 2,408 individuals over 18 years. This work is divided into three main sections. In the fi rst, a scale has been built from the results of the application of different items present in the questionnaire used. The second part explores the relationships of the scale obtained with the variables further approximate the emotional dimensions of individuals. The third part observes the variables that contribute to changes in the scale: These variables show the structural feature of the ontological security.

The new research centre of the Brazilian Petroleum Company in Rio de Janeiro, Brazil: The achievements in the thermal performance of air-conditioned buildings in the tropics

The study on the thermal performance of the air-conditioned buildings of the new research centre of the Brazilian Petroleum Company, in the tropical climate of Rio de Janeiro, was part of a bigger research and consultancy, project involving environmental issues. The architectural design was the subject of a national competition in 2004, encompassing over 100,000 m(2). According to the design brief, out of the 10 buildings of the new research centre, 7 have to be either completely or partially air-conditioned, due to specific occupation requirements. The challenge for better thermal performance was related to systems` energy efficiency, to the introduction of natural ventilation and to the notion of adaptive comfort, which were verified with the support of thermal dynamic simulations. At the early stages of the assessments, the potential for natural ventilation in the working spaces considering the mixed-mode strategy achieved 30% of occupation hours. However, the development of the design project led to fully air-conditioned working spaces, due to users` references regarding the conventional culture of the office environment. Nevertheless, the overall architectural approach in accordance to the climatic conditions still showed a contribution to the buildings` energy efficiency. (C) 2008 Elsevier B.V. All rights reserved.

Participatory assessment of rural livelihoods in the Central Highlands of Vietnam

There is a need for improved monitoring and evaluation (M&E) of participatory research with smallholder farmers, in particular to help differentiate between different types of farm household with different needs. This paper reports some of the results of a study to develop participatory M&E tools for the Forages for Smallholders Project in Southeast Asia, focusing on an upland commune in central Vietnam with a highly diverse crop-livestock system. Participatory rural appraisal techniques were used within a rural livelihoods framework to assess the differing livelihoods of poor, average, and better-off households. There were found to be marked differences between households, particularly in human resources, landholdings, and cattle numbers, affecting the livelihood strategies pursued. The improved understanding of livelihood strategies was gained in a cost-effective way and could be readily used by project participants to monitor the impacts of the introduced forages within the commune, enabling better focusing of the participatory research process on the needs and circumstances of poor farmers. (C) 2003 Elsevier Ltd. All rights reserved.

Current smoking and the risk of non-fatal myocardial infarction in the WHO MONICA Project populations

Background: Cohort studies have shown that smoking has a substantial influence on coronary heart disease mortality in young people. Population based data on non-fatal events have been sparse, however. Objective: To study the impact of smoking on the risk of non-fatal acute myocardial infarction (MI) in young middle age people. Methods: From 1985 to 1994 all non-fatal MI events in the age group 35 - 64 were registered in men and women in the WHO MONICA ( multinational monitoring of trends and determinants in cardiovascular disease) project populations ( 18 762 events in men and 4047 in women from 32 populations from 21 countries). In the same populations and age groups 65 741 men and 66 717 women participated in the surveys of risk factors ( overall response rate 72%). The relative risk of non-fatal MI for current smokers was compared with non-smokers, by sex and five year age group. Results: The prevalence of smoking in people aged 35 - 39 years who experienced non-fatal MI events was 81% in men and 77% in women. It declined with increasing age to 45% in men aged 60 - 64 years and 36% in women, respectively. In the 35 - 39 years age group the relative risk of non-fatal MI for smokers was 4.9 (95% confidence interval (CI) 3.9 to 6.1) in men and 5.3 ( 95% CI 3.2 to 8.7) in women, and the population attributable fractions were 65% and 55%, respectively. Conclusions: During the study period more than half of the non-fatal MIs occurring in young middle age people can be attributed to smoking.

Scenario Planning and Evaluation of Pricing Strategies in the Portuguese Bulk LPG Market

Portugal has the largest LPG (Liquefied Petroleum Gas) share of primary energy demand in the EU (about 5%). Due to the increasing international cost of LPG in the last years and the high price sensitivity of the consumers the preference for substitute energy sources in new and existing consumers has been increasing. To select the kind of energy, some consumer estimate and compare the total costs while others follow agents (equipment sellers) recommendations. It takes time to build agents perception about the most advantageous source of energy, which is seen as an important resource that drives client resource accumulation and retention. Marketing strategies have to take into consideration some market dynamic effects derived from the accumulation and depletion of these resources. A simple system dynamics model was built, combined with Economic Value Added framework, to evaluate some pricing strategies under different scenarios of LPG international cost.

Scenario Planning and Evaluation of Pricing Strategies in the Portuguese Bulk LPG Market

Portugal has the largest LPG (Liquefied Petroleum Gas) share of primary energy demand in the EU (about 5%). Due to the increasing international cost of LPG in the last years and the high price sensitivity of the consumers the preference for substitute energy sources in new and existing consumers has been increasing. To select the kind of energy, some consumer estimate and compare the total costs while others follow agents (equipment sellers) recommendations. It takes time to build agents perception about the most advantageous source of energy, which is seen as an important resource that drives client resource accumulation and retention. Marketing strategies have to take into consideration some market dynamic effects derived from the accumulation and depletion of these resources. A simple system dynamics model was built, combined with Economic Value Added framework, to evaluate some pricing strategies under different scenarios of LPG international cost.