Psychological characteristics of volunteers in studies on gambling

Advertisements were published in local newspapers asking for volunteers to participate in a study on gambling. A battery of eleven questionnaires was mailed to the subjects assessing pathological gambling behavior, sociodemographic characteristics, motivation to gamble, erroneous perceptions about gambling, superstitious beliefs, depressive symptoms, social anxiety and avoidance, alcohol and drug abuse, problem-solving skills, and marital satisfaction. Subjects received $10 when they returned the questionnaires fully completed. Response rate was over 95%. Surprisingly, 29% of the respondents met the criterion for probable pathological gambling (score of 5 or more on the SOGS) and a further 16% were identified as potential pathological gamblers (scores of 3 or 4). The potential and probable pathological gamblers showed significant differences on motivational and cognitive variables related to gambling compared to those subjects who showed no signs of pathological gambling. The probable pathological gamblers reported significantly more signs of poor psychosocial functioning than the other two groups, including depressive symptoms, poor problem orientation, drug and alcohol abuse, and interpersonal conflict. The practical and theoretical implications of these results are discussed.     

Parental Divorce and Offspring Depressive Symptoms: Dutch Developmental Trends During Early Adolescence

In this study, we investigated if the association between parental divorce and depressive symptoms changes during early adolescence and if developmental patterns are similar for boys and girls. Data were collected in a prospective population cohort of Dutch adolescents (N = 2,149), aged 10 – 15 years. Outcome variables were self‐reported and parent‐reported depressive symptoms. The effects of divorce were adjusted for parental depression. In both self‐reported and parent‐reported data, we found a three‐way interaction of gender, age, and parental divorce, indicating that with increasing age, parental divorce became more strongly associated with depressive symptoms among girls, but not boys. These results suggest that girls with divorced parents are at particularly high risk to develop depressive symptoms during adolescence.     

Análisis de la contextualización del comportamiento adaptativo en el retraso mental: Comparación entre contexto familiar e institucional

Resumen

Este estudio se dirige a contrastar las diferencias en el comportamiento adaptativo de los sujetos retrasados que son producto de los diferentes contextos en los que éste es emitido. En este caso, el contexto se entiende como los aspectos físicos y sociales del lugar en el que inmediatamente se produce la conducta. Esta perspectiva molecular del contexto ha permitido detectar diferencias en el comportamiento adaptativo en términos de lenguaje receptivo y lenguaje expresivo. La muestra utilizada fueron 71 sujetos evaluados a través del West Virginia assessment and tracking system.     

A Case Study of De-randomization Methods for Combinatorial Approximation Algorithms

We study three different de-randomization methods that are often applied to approximate combinatorial optimization problems. We analyze the conditional probabilities method in connection with randomized rounding for routing, packing and covering integer linear programming problems. We show extensions of such methods for non-independent randomized rounding for the assignment problem. The second method, the so-called random walks is exemplified with algorithms for dense instances of some NP problems. Another often used method is the bounded independence technique; we explicit this method for the sparsest cut and maximum concurrent flow problems.     

A multivariate uniformity test for the case of unknown support

A test for the hypothesis of uniformity on a support S⊂ℝ ^d is proposed. It is based on the use of multivariate spacings as those studied in Janson (Ann. Probab. 15:274–280, 1987). As a novel aspect, this test can be adapted to the case that the support S is unknown, provided that it fulfils the shape condition of λ-convexity. The consistency properties of this test are analyzed and its performance is checked through a small simulation study. The numerical problems involved in the practical calculation of the maximal spacing (which is required to obtain the test statistic) are also discussed in some detail.     

Factorial Validity and Invariance of the Rosenberg Self-Esteem Scale Among Portuguese Youngsters

The purpose of the present study was to examine the reliability, factorial validity and measurement invariance (across gender, age and physical activity participation) of a Portuguese version of the Rosenberg Self-Esteem Scale (RSES). The sample consisted of 1,763 Portuguese youngsters (731 male and 1,032 female) with ages between 15 and 20 years. Reliability estimate for the one-factor solution was .845, although some proposed RSES’s underlying dimensions were lower than .70. Confirmatory factor analysis revealed that the best-fitting model was a single self-esteem factor, plus simultaneous correlated uniqueness for positively and negatively worded items. Multigroup analysis supported measurement invariance across age and physical activity participation, and partial metric invariance across gender, as three items failed to show metric equivalence. These results provide evidence that RSES has excellent psychometric properties and it is a valid self-esteem measure to be used among Portuguese youngsters.     

New algorithms for k-center and extensions

The problem of interest is covering a given point set with homothetic copies of several convex containers C ₁,…,C _k , while the objective is to minimize the maximum over the dilatation factors. Such k-containment problems arise in various applications, e.g. in facility location, shape fitting, data classification or clustering. So far most attention has been paid to the special case of the Euclidean k-center problem, where all containers C _i are Euclidean unit balls. Recent developments based on so-called core-sets enable not only better theoretical bounds in the running time of approximation algorithms but also improvements in practically solvable input sizes. Here, we present some new geometric inequalities and a Mixed-Integer-Convex-Programming formulation. Both are used in a very effective branch-and-bound routine which not only improves on best known running times in the Euclidean case but also handles general and even different containers among the C _i .     

Characterizations of discrete distributions based on conditional expectations of record values

r -th record values subject to (r + 1)-th record values, record mean function, from a distribution of discrete type. We give some properties of the record mean function and an explicit expression for the distribution function based on its record mean function, which allows us to characterize particular discrete distributions using the record mean functions. Received: January 4, 1999; revised version: September 27, 1999     

Aggregation of coarse preferences

We consider weak preference orderings over a set A _n of n alternatives. An individual preference is of refinement?≤n if it first partitions A _n into ? subsets of `tied' alternatives, and then ranks these subsets within a linear ordering. When ?<n, preferences are coarse. It is shown that, if the refinement of preferences does not exceed ?, a super majority rule (within non-abstaining voters) with rate 1− 1/? is necessary and sufficient to rule out Condorcet cycles of any length. It is argued moreover how the coarser the individual preferences, (1) the smaller the rate of super majority necessary to rule out cycles `in probability'; (2) the more probable the pairwise comparisons of alternatives, for any given super majority rule. Received: 29 June 1999/Accepted: 25 February 2000     

Ranking sets additively in decisional contexts: an axiomatic characterization

Ranking finite subsets of a given set X of elements is the formal object of analysis in this article. This problem has found a wide range of economic interpretations in the literature. The focus of the article is on the family of rankings that are additively representable. Existing characterizations are too complex and hard to grasp in decisional contexts. Furthermore, Fishburn (1996), Journal of Mathematical Psychology 40, 64–77 showed that the number of sufficient and necessary conditions that are needed to characterize such a family has no upper bound as the cardinality of X increases. In turn, this article proposes a way to overcome these difficulties and allows for the characterization of a meaningful (sub)family of additively representable rankings of sets by means of a few simple axioms. Pattanaik and Xu’s (1990), Recherches Economiques de Louvain 56, 383–390) characterization of the cardinality-based rule will be derived from our main result, and other new rules that stem from our general proposal are discussed and characterized in even simpler terms. In particular, we analyze restricted-cardinality based rules, where the set of “focal” elements is not given ex-ante; but brought out by the axioms.