Optimal k-circulant supersaturated designs

Optimal k-circulant supersaturated designs have been constructed in literature using computer intensive methods. A systematic method of construction for multi-level experiments based on balanced incomplete block designs is presented in this paper. The method is also applicable to two-level experiments. Illustrative examples are also given.     

Controlling for initial endowment and experience in binary choice tasks

Learning literature typically assumes that initial attractions to choose each possible alternative are given exogenously. However, evidence shows that current behaviour depends on past experiences. In this paper, we design an experiment to control for the initial experience in decisions from experience by providing decision makers with an exogenous history (successful vs. unsuccessful) prior to initiating the decision task. Moreover, varying the initial endowment level for fixed histories we investigate the income effect. We are also interested in analysing the duration of both effects (history and income). We find significant treatment effects in the sense that more risk taking behaviour is associated with good histories and with low income levels. According to previous literature, our results confirm the transitory nature of both effects, although the duration of the income effect doubles the duration of the history effect. In the long run, risky choice behaviour converges across different treatments.     

Urban transition toward food sovereignty

In cities throughout the world, people are taking steps to develop just, sustainable alternatives to the dominant food system. These initiatives pose questions which, to be answered, require new theoretical approaches. This study makes use of Marx's concepts of ‘social metabolism’ and ‘metabolic rift’, as well as Altvater's analysis of forms of capitalist appropriation, in order to understand how current society-nature relationships have given way to a socioeconomic spatial order which makes it difficult to develop just, sustainable food systems. From this theoretical framework, we identify and analyse some key aspects of the urban transition toward food sovereignty.     

The joy of ruling: an experimental investigation on collective giving

We analyse team dictator games with different voting mechanisms in the laboratory. Individuals vote to select a donation for all group members. Standard Bayesian analysis makes the same prediction for all three mechanisms: participants should cast the same vote regardless of the voting mechanism used to determine the common donation level. Our experimental results show that subjects fail to choose the same vote. We show that their behaviour is consistent with a joy of ruling: individuals get an extra utility when they determine the voting outcome.     

Work situation operative model MOST: linking diagnosis and intervention to improve work conditions

This paper presents the model "Work Situation Operative Model" - MOST (after its Spanish acronym). It offers a comprehensive, systemic approach to analysing work stations and/or work processes, serving also as a framework for pursuing various ergonomic and occupational health and safety goals. Originally produced for a food sector company, the model has been extended and successfully applied in several industries in Colombia and Ecuador, including cement, oil, and paper industries. Based on a systemic understanding of work systems and tasks, the model not only allows different, commonly-used methods and tools for evaluating or assessing the risk of muscular-sketetal disorders to be included, but also supports occupational risk management strategies. Hence, one of its more important contributions relies on providing meaningful information that is useful for improving the work station and/or work process through design and re-design, by focusing on the interactions between all system elements.     

Latinos’ Changing Ethnic Group Representation From Elementary to Middle School: Perceived Belonging and Academic Achievement

This study examined the association between change in ethnic group representation from elementary to middle school and Latino students’ school belonging and achievement. The ethnic diversity of students’ middle school was examined as a moderator. Participants were 1,825 Latino sixth graders from 26 ethnically diverse urban middle schools. Hierarchical regression analyses showed that a change in ethnic representation toward fewer Latinos in middle school than elementary school was related to less perceived belonging and lower achievement in schools with low ethnic diversity. There were no mean differences as a function of declining representation in more diverse middle schools, suggesting that greater school diversity was protective. Findings highlight the importance of examining school ethnic context, especially across the middle school transition.     

Toddler Inhibitory Control,Bold Response to Novelty,and Positive Affect Predict Externalizing Symptoms in Kindergarten

Poor inhibitory control and bold approach have been found to predict the development of externalizing behavior problems in young children. Less research has examined how positive affect may influence the development of externalizing behavior in the context of low inhibitory control and high approach. We used a multi‐method approach to examine how observed toddler inhibitory control, bold approach, and positive affect predicted externalizing outcomes (observed, adult‐, and self‐reported) in additive and interactive ways at the beginning of kindergarten. Children who were 24‐month‐olds (N = 110) participated in a laboratory visit and 84 were followed up in kindergarten for externalizing behaviors. Overall, children who were low in inhibitory control, high in bold approach, and low in positive affect at 24 months of age were at greater risk for externalizing behaviors during kindergarten.     

Psychometric properties and criterion validity of the Perceived Vulnerability to Disease Scale (PVD) in the Spanish population / Propiedades psicométricas y validez de criterio de la escala de Percepción de Vulnerabilidad a la Enfermedad (PVE en población española)

Perceived Vulnerability to Disease may be defined as the beliefs about personal susceptibility to the transmission of infectious diseases and the emotional discomfort associated with the potential disease transmission. To evaluate these beliefs, the Perceived Vulnerability to Disease Scale (PVD) has been used in most studies. The aim of Study 1 was to validate the PVD questionnaire to the Spanish population. The sample was made up of 744 university students from all over Spain. Confirmatory factor analysis revealed that the items on the short version of the questionnaire corresponding to an interrelated two-factor model (perceived infectability and germ aversion) showed the best fit of all the tested models. In Study 2, scales to measure antifat attitudes, disgust and negative attitudes towards AIDS were used to analyse the criterion validity of the PVD questionnaire. The sample was made up of 434 university students. It was found that germ aversion was positively related with antifat attitudes, disgust and negative attitudes towards AIDS. In light of these results, we conclude that the short version of the questionnaire has good psychometric properties and can be used by the scientific community to measure Perceived Vulnerability to Disease.     

Are Nuclear-Weapon States not Parties to the Non-proliferation Treaty Ready to Renounce to the Possession of Nuclear Weapons?

The situation of nuclear-weapon states not parties to the NPT is different from the situation of the nuclear-weapon states parties to that treaty. This last group of countries has signed and ratified a treaty that encourage them to begin negotiations in good faith for the discussion of concrete measures that lead them to nuclear disarmament, while the first group of states have made no commitment to do that. In other words, nuclear-weapon states not parties to the NPT have made no commitment to nuclear disarmament and are not obliged to report anything related to the possession of nuclear weapons to the any specific body or organ or to the international community. Taking into account the position of nuclear-weapon states parties to the NPT regarding the possession of nuclear weapons, there is no possibility to convince nuclear-weapon states not parties to this treaty to renounce to the possession of this type of weapons under the present circumstances.