Neurocognitive Effects in Welders Exposed to Aluminium: An Application of the NPC Test and NPC Ranking Methods

The aim of this study is to investigate the effects of exposure to aluminium on the cognitive sphere in a group of welders. Given the intrinsic complexity of the neurocognitive sphere, three different psychomotor variables were used for its investigation allowing the resulting problem to be naturally modelized into a multivariate framework and solved by a nonparametric combination of permutation tests (NPC test). In order to make the treated and control groups comparable, we also stratified the samples on the basis of a risk index that estimates the combined action of biological age and exposure time. Despite the fact that studies in the literature have reached conflicting results, our study highlights a significant drop in attention and memory performances in individuals exposed to aluminium. Finally, we identify a global criterion that summarises the information on the neurocognitive state by applying the nonparametric combination of dependent rankings method (NPC ranking).     

The Effect of Changing Sexual, Marital and Contraceptive Behaviour on Conceptions, Abortions, and Births

A model is proposed to estimate the number of conceptions during a single year using scarce survey data, official data on births and abortions for the two years following the survey, and some parameters on contraception failure. The model is fitted for 1979, 1989, 1994 to Puglia, a Southern Italian region with a population of 4 millions. Simulations are also produced.The decrease in births is caused mainly by the decline in wanted births, whereas the decline in abortions is caused by diffusion of the pill, IUD, and condom. The rapid increase in the proportion of never-married women explains the slow decrease in unwanted births and conceptions, compared to the fast decline in wanted ones. This situation is different compared to other Western countries (e.g. France, UK, and USA) where the decline in TFR during the 1960s and 1970s was largely caused by the decline in unwanted fertility, thanks to improved modern contraception and sterilisation.     

Why communities of practice succeed and why they fail

A specific form of intra-organizational networks – a community of practice (COP) – is increasingly regarded as an important structure within organizations. This network structure is well suited for the development and sharing of knowledge and practices across divisions. Our research explores the most salient reasons for the success and failure of such networks. An investigation of 57 COPs from major European and US companies led to the discovery of 10 “commandments” that lead to the successful development and sharing of best practices. It also identified five main reasons for failure.     

Agriculture,Pesticide Use,and Economic Development: A Global Examination (1990–2014)

Modern agricultural production typically requires large quantities of chemical pesticides, a potential source of both environmental and human harm. Previous social science research has suggested that environmental problems such as those associated with pesticide use may begin to decline at higher levels of economic development. Using fixed effects models, we examine whether this possible relationship holds within nations and over time. This study draws on data from the World Bank as well as pesticide use data from the Food and Agriculture Organization of the United Nations to examine the relationship between pesticide use and economic development within nations from 1990 to 2014. The findings are considered from theoretical perspectives in environmental sociology on the drivers of environmental impacts: the treadmill of production theory, structural human ecology, ecological modernization theory, and the environmental Kuznets curve hypothesis. The results of this study show a positive relationship between economic development and pesticide consumption over time, with no decline in use at higher levels of economic development. Thus, they generally support the claims made by treadmill of production and structural human ecology.     

A Bayesian non-parametric modeling to estimate student response to ICT investment†

This paper estimates the causal impact of investment in information and communication technologies (ICT) on student performances in mathematics as measured in the Program for International Student Assessment (PISA) 2012 for Spain. To do this we apply a new methodology in this context known as Bayesian Additive Regression Trees that has important advantages over more standard parametric specifications. Results indicate that ICT has a moderate positive effect on math scores. In addition, we analyze how this effect interacts with variables related to school features and student socioeconomic status, finding that ICT investment is especially beneficial for students from a low socioeconomic background.     

Association of Problem Gambling with Type of Gambling Among Italian General Population

The origin of gambling disorders is uncertain; however, research has shown a tendency to focus on specific types of games as a potential important risk factor. The principal aim of this study is to examine the relationships between types of gambling practices and gambling disorder. The data were extracted from IPSAD-Italia^® 2010–2011 (Italian Population Survey on Alcohol and other Drugs), a survey among the Italian general population which collects socio-cultural information, information about the use of drugs, legal substances and gambling habits. In order to identify the “problem gambler” we used the Problem Gambling Severity Index. Three groups are considered in this analysis: no-risk gamblers, low-risk gamblers, moderate-risk/problem gamblers. Type of gambling practice was considered among two types of gambler: one-game players and multi-games players. 1.9 % of multi-game players were considered problem gamblers, only 0.6 % of one-game players were problem gamblers (p < 0.001). The percentage of players who were low and moderate-risk gamblers was approximately double among multi-game players, with 14.4 % low-risk and 5.8 % moderate-risk; compared with 7.7 % low-risk and 2.5 % moderate risk among one-game players. Results of ordinal logistic regression analysis confirmed that higher level of gambling severity was associated with multi-game players (OR = 2.23, p < 0.0001). Video-poker/slot-machines show the highest association with gambling severity among both one-game players and multi-game players, with scores of OR equal to 4.3 and 4.5 respectively. These findings suggest a popular perception of risk associated with this type of gambling for the development of gambling problems.     

Does Immigration Raise Blue and White Collar Wages of Natives? The Case of Italy

This paper analyses both theoretically and empirically the effects of immigration on the wage rate of native workers. There is rare evidence in empirical literature that immigration generates a fall in the wages of manual workers. By hypothesizing an economic system where advanced firms buy an intermediate good from traditional firms, which employ manual workers in both clean and dirty tasks, the latter being more disliked by native workers, we present a theoretical model that justifies these results. We conclude that native skilled wages always increase whereas native unskilled wages can both increase or decrease with immigration. An empirical analysis of the Italian labour market follows, showing that native workers' wages always rise with immigration.