Do spouses cooperate? An experimental investigation

This study makes a significant contribution to investigations of household behavior by testing for a willingness to cooperate and share income by men and women who are either in couple with each other or complete strangers. We present results from an economic experiment conducted with 100 co-habiting heterosexual couples. We compare defection behavior in the prisoner’s dilemma within real couples to pairs of strangers. One out of four participants chose not to cooperate with their spouse. To understand why spouses might prefer defection, we use a novel allocation task to elicit the individual’s trade-off between efficiency and equality within a couple. We further investigate the impact of socio-demographic and psychological characteristics of the couples. We find in particular that lack of preferences for joint income maximization, having children and being married lead to higher defection rates in the social dilemma.     

Thermal,viscoelastic and mechanical properties' optimization of polyphenylene sulfide via optimal processing parameters using the Taguchi method

Thermal, viscoelastic and mechanical properties of polyphenylene sulfide (PPS) were optimized as a function of extrusion and injection molding parameters. For this purpose, design of experiments approach utilizing Taguchi's L₂₇ (3⁷) orthogonal arrays was used. Effect of the parameters on desired properties was determined using the analysis of variance. Differential scanning calorimeter (DSC) tests were performed for the analysis of thermal properties such as melting temperature (T_m) and melting enthalpy (ΔH_M). Dynamic mechanical analysis (DMA) tests were performed for the analysis of viscoelastic properties such as damping factor (tan?δ) and glass transition temperature (T_g). Tensile tests were performed for the analysis of mechanical properties such as tensile strength and modulus. With optimized process parameters, verification DSC, DMA and tensile tests were performed for thermal, viscoelastic and mechanical properties, respectively. The Taguchi method showed that ‘barrel temperature’ and its level of ‘340°C’ were seen to be the most effective parameter and its level; respectively. It was suggested that PPS can be reinforced for further improvement after optimized thermal, viscoelastic and mechanical properties.     

Methylmercury Risks and EPA + DHA Benefits Associated with Seafood Consumption in Europe

The intake of methyl‐Hg and EPA + DHA through consumption of seafood in Europe as well as the associated probability of exceeding the provisional tolerable weekly intake (PTWI) and the recommended daily intake (RDI), respectively, were estimated by combining methyl‐Hg and EPA + DHA contents in the five most consumed seafood species with hypothesized consumption distributions for eight European countries, chosen on the basis of size and representative significance. Two estimators were used: plug‐in (PI) and tail estimation (TE). The latter was based on the application of the extreme value theory to the intakes distribution curves. Whereas contents data were collected from own database and published scientific papers, consumption data were obtained from statistical sources of the various countries. Seafood consumption levels varied considerably between countries, from 140 in the United Kingdom to 628.5 g/(person.week) in Iceland. The main consumed species were also different between countries. The probability of exceeding the methyl‐Hg PTWI ranged from 0.04% in the United Kingdom to 9.61% in Iceland. Concerning the probability of exceeding the RDI of EPA + DHA, Iceland was third, after Portugal (66.05%) and Spain (61.05%) and the United Kingdom was the last (0.32%). While TE was most accurate for small probabilities, PI yielded best estimates for larger probabilities.     

Feasibility Study on the Use of Probabilistic Migration Modeling in Support of Exposure Assessment from Food Contact Materials

The use of probabilistic approaches in exposure assessments of contaminants migrating from food packages is of increasing interest but the lack of concentration or migration data is often referred as a limitation. Data accounting for the variability and uncertainty that can be expected in migration, for example, due to heterogeneity in the packaging system, variation of the temperature along the distribution chain, and different time of consumption of each individual package, are required for probabilistic analysis. The objective of this work was to characterize quantitatively the uncertainty and variability in estimates of migration. A Monte Carlo simulation was applied to a typical solution of the Fick's law with given variability in the input parameters. The analysis was performed based on experimental data of a model system (migration of Irgafos 168 from polyethylene into isooctane) and illustrates how important sources of variability and uncertainty can be identified in order to refine analyses. For long migration times and controlled conditions of temperature the affinity of the migrant to the food can be the major factor determining the variability in the migration values (more than 70% of variance). In situations where both the time of consumption and temperature can vary, these factors can be responsible, respectively, for more than 60% and 20% of the variance in the migration estimates. The approach presented can be used with databases from consumption surveys to yield a true probabilistic estimate of exposure.     

Generalizing the Welch Test To Non-Zero Hypotheses on the Variance Component in the One-Way Random Effects Model Under Variance Heterogeneity

In an unbalanced and heteroscedastic one-way random effects model of analysis of variance we consider hypotheses concerning the between group variance where in a classical set-up the hypothesis whether this variance component is zero is tested. We consider the still open problem of testing also extended hypotheses concerning this parameter and generalize the prominent Welch test to deal with these hypotheses, too.     

Longitudinal Associations Between Other‐Sex Friendships and Substance Use in Adolescence

The impact of the changes in the gender composition of friendship networks during early adolescence on substance use in late adolescence was examined. The hypothesis was that initial level and increase in the proportion of other‐sex friends in the network would be associated with higher levels of substance use among girls, but not among boys. Girls and boys (n=390) were interviewed annually from ages 12 to 18 (79% retention). For both boys and girls, initial level in the proportion of other‐sex friends predicted alcohol use in late adolescence, whereas it was predictive of drug use in girls only. Moreover, for girls only, a faster increase in the proportion of other‐sex friends in the network predicted later use of alcohol and drugs.     

Inflation targeting and the exchange rate: Does it matter in Turkey?

This paper investigates the monetary policy reaction functions of the Central Bank of Republic of Turkey (CBRT) over the periods 1987:01–2001:12 and 2002:01–2009:05. We specifically attempt to shed light on question to what extent exchange rate developments still continue to influence monetary policy, even under inflation targeting. This study seeks to investigate how the monetary policy responded to the exchange rate shocks before and after adoption of inflation targeting regime. How large the effect of exchange rate shocks is accounted for in forecast error variances decompositions for monetary policy as compared to other shocks? Using the VAR model, this study shows that there has been strong pass-through during whole period. Moreover, in the postcrisis period, exchange rate has been the main reaction variable for the CBRT.     

Bayesian Development of a Dose‐Response Model for Aspergillus fumigatus and Invasive Aspergillosis

Invasive aspergillosis (IA) is a major cause of mortality in immunocompromized hosts, most often consecutive to the inhalation of spores of Aspergillus. However, the relationship between Aspergillus concentration in the air and probability of IA is not quantitatively known. In this study, this relationship was examined in a murine model of IA. Immunosuppressed Balb/c mice were exposed for 60 minutes at day 0 to an aerosol of A. fumigatus spores (Af293 strain). At day 10, IA was assessed in mice by quantitative culture of the lungs and galactomannan dosage. Fifteen separate nebulizations with varying spore concentrations were performed. Rates of IA ranged from 0% to 100% according to spore concentrations. The dose‐response relationship between probability of infection and spore exposure was approximated using the exponential model and the more flexible beta‐Poisson model. Prior distributions of the parameters of the models were proposed then updated with data in a Bayesian framework. Both models yielded close median dose‐responses of the posterior distributions for the main parameter of the model, but with different dispersions, either when the exposure dose was the concentration in the nebulized suspension or was the estimated quantity of spores inhaled by a mouse during the experiment. The median quantity of inhaled spores that infected 50% of mice was estimated at 1.8 × 10⁴ and 3.2 × 10⁴ viable spores in the exponential and beta‐Poisson models, respectively. This study provides dose‐response parameters for quantitative assessment of the relationship between airborne exposure to the reference A. fumigatus strain and probability of IA in immunocompromized hosts.     

A Communication Perspective on Video Lottery Terminals

Video Lottery Terminals (VLT) are associated with pathological gambling and with most of the requests for help in combating gambling addiction. Embeddedness of a person in his or her social network is among the communicational factors that may help explain this phenomenon. To verify this, we compared ego networks of VLT gamblers, of gamblers of games with low request for help and of VLT gamblers in treatment (n = 90). The networks of regular VLT gamblers are small and dense and offer little social support. Gamblers in treatment also have small networks, but they are less dense, have more components and offer more social support. Networks of gamblers with low requests for assistance are approximately twice the size as those of VLT gamblers, are sparser and offer more companionship. In conclusion, the VLT gambler is not an isolated individual, but rather an individual ‘shut-in’ a small network of tightly knitted relationships.