Lean and mean rats: Some effects of acute changes in the food supply upon territorial aggression

In experiment 1, individually housed rats subjected to short-term food restriction displayed more territorial aggression toward conspecific intruders than controls maintained on a free-feeding diet. In experiment 2, small groups of three adult male rats had access to either a standard laboratory diet or the standard diet plus sucrose. Groups with the sucrose supplement were significantly less aggressive toward intruders than controls. Sucrose availability did not produce appreciable gains in body weight but it did reliably decrease within-colony weight variation. The results suggest the existence of an effective dietary mechanism that enables a social species such as Rattus norvegicus to tolerate each other in dense feeding aggregations when food is abundant. Conversely, when food is limited, social intolerance increases and serves to limit the development of large feeding groups.     

Addressing Weight Suppression to Improve Treatment Outcome for Bulimia Nervosa

Cognitive behavioral therapy (CBT) is regarded as the gold-standard treatment for bulimia nervosa (BN), yet despite impressive empirical support for its effectiveness, over 50% of patients fail to achieve abstinence from binge eating and purging by the end of treatment. One factor that may contribute to reduced efficacy rates in CBT is weight suppression (WS; the difference between a person's highest weight ever at their adult height and current weight). A growing body of research indicates that WS in patients with BN may have a clinically significant effect on symptomatology and prognosis. However, the current cognitive behavioral framework for BN does not explicitly acknowledge the role of WS in the onset or maintenance of BN symptoms and does not provide guidance for clinicians on how to address WS during treatment. The relationship between WS, biological pressure to regain lost weight, and the maintenance of BN symptoms suggest that current cognitive behavioral models of BN may be improved by considering the role of WS and exploring needed treatment modifications. Indeed, a reconceptualization of existing models may offer insight into potential strategies that can be used to reduce the susceptibility to treatment dropout, nonresponse, and relapse. It is therefore necessary to consider whether, and how, clinicians' consideration of WS during case conceptualization and treatment planning could serve to improve CBT outcomes. The current review explores ways in which high WS could contribute to poor CBT outcomes, provides preliminary clinical recommendations for incorporating WS into existing cognitive behavioral treatments based on extant data and clinical wisdom, and proposes suggestions for future research needed in this domain.     

Influence in canonical correlation analysis

The perturbation theory of the generalized eigenproblem is used to derive influence functions of each squared canonical correlation coefficient and the corresponding canonical vector pair. Three sample versions of these functions are described and some properties are noted. As particular applications, the influence function of the squared multiple correlation coefficient and influence functions of eigenvalues and eigenvectors in correspondence analysis are obtained. Three numerical examples are briefly discussed.We thank the Editor and the anonymous reviewers for their helpful comments. This research was carried out with the financial support of the Italian Ministry of the University and the National Research Council.     

Predicting 2-year weight loss through temporally specific earlier losses,relevant behaviors,and their psychological correlates: Implications for behavioral treatment architectures

Maintaining loss of weight beyond an initial 6–9 months remains problematic, with research indicating little recent progress. A poor understanding of how and when prior weight loss, behavioral changes, and psychosocial predictors are associated with long-term weight changes persists. To better-inform behavioral treatments for long-term success with weight loss, women with obesity (N = 86; M_age = 48.6 years) volunteered for research incorporating community-based weight-management treatments. They were assessed at months 6, 12, and 24 on theory-based psychosocial and behavioral factors, and over 24 months on weight. Considering the included times and temporal ranges, it was found that change in weight from month 6–24 was the strongest predictor of 24-month weight change, and physical activity and fruit/vegetable intake at month 24 best predicted that change in weight. Self-regulation, self-efficacy, and mood at month 24 best predicted both physical activity and fruit/vegetable intake at month 24, with body satisfaction also a significant predictor of physical activity. From these data, mediation analyses found that the predictions of long-term weight loss by scores of self-regulation, self-efficacy, body satisfaction, and mood at month 24 were significantly mediated by fruit/vegetable intake and physical activity in separate equations. Findings indicated both psychosocial and behavioral targets, and timing for those targets, most indicative of long-term success with weight loss.     

Some symmetric,invariant measures of multivariate association

A distinction is drawn between redundancy measurement and the measurement of multivariate association for two sets of variables. Several measures of multivariate association between two sets of variables are examined. It is shown that all of these measures are generalizations of the (univariate) squared-multiple correlation; all are functions of the canonical correlations, and all are invariant under linear transformations of the original sets of variables. It is further shown that the measures can be considered to be symmetric and are strictly ordered for any two sets of observed variables. It is suggested that measures of multivariate relationship may be used to generalize the concept of test reliability to the case of vector random variables.     

平辈亲属词语义加工中长幼概念的空间隐喻和重量隐喻——来自中国朝鲜族和汉族的证据

采用具身认知范式考察平辈亲属词语义加工中长幼概念的空间和重量隐喻,比较中国朝鲜族和汉族的长幼观念。实验1表明,中国朝鲜族人在平辈亲属词语义加工中对平辈年长亲属词的加工快于对平辈年幼亲属词的加工,并且存在着部分的上下隐喻一致性效应,平辈年幼亲属词呈现在屏幕的下方加工得快。汉族人在平辈亲属词语义加工中存在着完整的上下隐喻一致性效应:平辈年长亲属词呈现在屏幕上方加工得快,平辈年幼亲属词呈现在屏幕下方加工得快。实验2表明,"左大右小"的亲属词对促进了中国朝鲜族人对"左重右轻"天平倾斜方向的判断,表明亲属词对蕴含的长幼概念激活了重量概念,但对汉族人的天平倾斜方向判断却无显著的影响。实验3表明,"左重右轻"的天平倾斜方向促进了中国朝鲜族人对"左大右小"的朝鲜语亲属词对的年龄比较,表明重量加工激活了长幼概念,但不影响汉族人对汉语亲属词对的年龄比较。朝、汉两个民族对平辈亲属词的不同隐喻方式源于不同的文化图式,反映了两个民族的长幼文化的差异:与汉族人相比,中国朝鲜族人更重视长幼秩序,对长幼规范的要求更加严格。     

FINITE MODELS CONSTRUCTED FROM CANONICAL FORMULAS

This paper obtains the weak completeness and decidability results for standard systems of modal logic using models built from formulas themselves. This line of work began with Fine (Notre Dame J. Form. Log. 16:229–237, 1975). There are two ways in which our work advances on that paper: First, the definition of our models is mainly based on the relation Kozen and Parikh used in their proof of the completeness of PDL, see (Theor. Comp. Sci. 113–118, 1981). The point is to develop a general model-construction method based on this definition. We do this and thereby obtain the completeness of most of the standard modal systems, and in addition apply the method to some other systems of interest. None of the results use filtration, but in our final section we explore the connection.     

Culture and body image: Body perception and weight concern in young Asian and Caucasian British women

The comparatively lower prevalence of eating disorders among Asian and Afro-Caribbean than Caucasian women in the UK has often been attributed to cultural differences in pressures for slimness. However, there have been no attempts to evaluate cultural differences in ideals for female physique directly among women in the at risk age groups. In the present study, cultural influences on body image were evaluated by comparing the body size ideals, body image and dieting concerns in a sample of 274 young white and Asian British women. The results indicate that Asian women are less likely to describe themselves as too fat, were less dissatisfied with their body size, less likely to want to lose weight and less restrained. However, Asian women were slimmer than white women and, after controlling for the difference in body size, the effects were reduced. The hypothesis that any body satisfaction differences could be explained by differences in ideal body size between the two groups were not supported; Asian women favoured even slimmer ideal body sizes than white women. Alternative explanations in terms of cultural differences in evaluation of fatness are discussed.     

Data, model, conclusion, doing it again

This paper explores the robustness of conclusions from a statistical model against variations in model choice (rather than variations in random sampling and random assignment to treatments, which are the usual variations covered by inferential statistics). After the problem formulation in section 1, section 2 presents an example from Box and Tiao in which variation in parent distribution is modeled for a one sample location problem. An adaptive Bayesian procedure permits to use a weighted mixture of parent distributions rather than choosing just one, such as a normal or a uniform distribution.In section 3 similar considerations are applied to an event history model for the influence of education and gender on age at first marriage, but here the conclusions are hardly influenced by the choice of the duration distribution. In section 4 a brief discussion of model choice in factor analysis and structural equation models is followed by a more elaborate treatment of the choice of integer valued slopes for item response functions in the OPLM model which is an extension of the Rasch model. A modest simulation study suggests that Adaptive Bayesian Modeling with a mixture of sets of slopes works better than fixing one set of postulated slopes.The paper concludes with some remarks on the roles and sources of prior distributions followed by a short epilogue which argues that simultaneous consideration of a class of models for the same data is sometimes superior to exclusively analyzing the data under one specific model chosen from such a class.This article is based on the Presidential Address Ivo W. Molenaar gave on June 20, 1998 at the 1998 Annual Meeting of the Psychometric Society held at the University of Illinois in Champaign, Illinois. Thanks is given to John Wiley & Sons and George C. Tiao for granting permission to reprint three figures from the book George C. Tiao wrote with George E. P. Box titled Bayesian Inference in Statistical Analysis.—EditorThanks are due to Anne Boomsma, Jeffrey Hoogland, Mark Huisman, Tom Snijders, Marijtje Van Duijn, and Norman Verhelst for suggesting improvements and/or assisting with data analyses.