The double sampling S2 chart with estimated process variance

This paper proposes useful exact bounds for the parameters of the double sampling S² chart with known process variance and it also investigates the properties of the double sampling S² chart with estimated process variance, in terms of the average run length, the standard deviation of the run length and the average sample size, providing a numerical comparison with the known process variance case. It also provides guidelines to systematically design the double sampling S² chart both with known and estimated process variance and proposes two optimal design procedures with estimated process variance, for (a) minimizing the out-of-control average run length and (b) minimizing the out-of-control average sample size.     

Marital Fertility and its Determinants in Rural and in Urban Spain, 1887–1930

Based primarily on census data between 1887 and 1920, the present article explores the basic structure of the social and economic factors that influenced marital fertility levels during the early part of the fertility transition in Spain. Multiple regression analysis is applied to ecological models based on separate rural and urban data. While some of the conclusions from the Princeton European Fertility Project have been corroborated, a number of the results have been quite noteworthy. Not the least of these are the sharply differing structures of causality in rural and urban areas, and the surprising and consistent role played by literacy as a stimulant of marital fertility. In the discussion of the results, we have insisted on the importance of interpreting different demographic, economic, and cultural indicators within concrete historical contexts.     

WORKERS,WARRIORS, AND CRIMINALS: SOCIAL CONFLICT IN GENERAL EQUILIBRIUM

We incorporate appropriation activities (social conflict) into canonical models of trade and study how economic shocks and policies affect the intensity of conflict. We show that not all shocks that could make society richer reduce conflict: positive shocks to labor‐intensive industries diminish conflict, while positive shocks to capital‐intensive industries increase it. The key requirement is that conflict activities be more labor intensive than the economy as this determines how shocks affect the returns and costs of conflict. Our theory is consistent with several observed patterns of conflict and implies that empirical work should take into account the relative factor intensities of the productive and conflict sectors in each country. Incorporating appropriation into a canonic general equilibrium model affects what policies may be deemed desirable: in order to reduce conflict and generate Pareto‐improvements policy must be distortionary, while reforms that appear efficiency‐enhancing under the unrealistic assumption of perfect property rights may backfire. This offers one explanation for why reforms based on traditional models without appropriation may be delayed and become unpopular when implemented, and why societies may sympathize with seemingly inefficient redistribution.     

The Child Support Enforcement Amendments of 1984 and Educational Attainment of Young Adults in the United States

ABSTRACT: We compare changes in the effect of child support payments on the educational attainment of children age 16 to 19 before and after passage of the Child Support Enforcement Amendments of 1984, which strengthened enforcement of child support obligations in the United States. Using 1979, 1984, and 1988 Current Population Survey data, we hypothesize and find a decline in the positive effect of child support between 1984 and 1988 that exceeds any earlier decline. Instrumental variables estimates provide additional evidence consistent with the idea that child support serves as an indicator of unobservable characteristics of noncustodial fathers who pay support.     

Urban gradients alter the diversity,specific composition and guild distribution in tropical butterfly communities

The increasing expansion of the urban environment has been considered one of the causes of biodiversity loss. Due to the decrease of the quantity and quality of habitats, this process causes the restriction of organisms to sometimes-specific microhabitats. The patterns of variation of the biodiversity along the environmental gradients, however, are still poorly understood. This study evaluated how urban gradients affect the diversity, specific composition and frequency of guild of the community of butterflies. Butterflies were collected in three transects continuously traversing the urban, rural and preserved habitats using baited traps and by active sampling. We found that the urban gradient acts as an environmental filter in the butterfly communities, reducing the richness and frequency of guilds of frugivorous butterflies, structuring the community through turnover, but without effects in the abundance. This study shows the importance of the urban gradients approach in the butterfly community and its applicability in the management of urban areas in order to include native vegetation along the gradients, aiming at increasing environmental heterogeneity, to preserve butterflies and maintain the ecosystem services and network interactions in altered landscapes.

     

Identification of the mental workload of public employees in the administrative sector at a public university

In the workplace there are risk factors that can overwhelm the health of the worker causing physical and psychological disorders. Among these disorders, is occupational stress. Thus, this research proposes to measure the mental workload of job stress from the identification of demand, control and social support. It is an observational cross-sectional epidemiological character, performed with the Rectory office workers at the State University of West Paraná (Unioeste). Data collection was due to the application of the "Job Stress Scale" (JSS) and in its reduced version adapted to Portuguese. The survey sample consisted of 44 individuals. Statistical analysis was correlated inversely with medium intensity (r = -0.404) between age and social support. For males was found between control and age (r = 0.603). According to the data obtained, we conclude that most workers are exposed to passive work, leading to loss of skills or disinterest in the job. This study highlights the importance of research in the area and the need for new actions that change the conditions of stress at work.     

Urban ergonomics: an ongoing study of city signs and maps

The purpose of this study is to assess whether the existing signals in three European cities were developed according usability principles and ergonomic aspects for the citizen. City maps and signals will be tested using efficiency, effectiveness and user's satisfaction criteria. Among the urban areas are the center of Paris-FR, assumed to be well signalized, the historical center of Guimar?es-PT and Chorweiler, Cologne-DE, a residential neighborhood of modern urbanism characterized by the extensive use of vegetation, the landscape homogeneity, and, consequently, by the difficult navigation.