Prevalence of dieting among working men and women: the healthy worker project

Examined dieting to lose weight in a population of 2,107 men and 2,540 women employed in 32 worksites in the upper Midwest. Lifetime prevalence of this behavior was estimated to be 47% in men and 75% in women, and point prevalence was reported as 13% and 25% in men and women, respectively. Lifetime prevalence of participation in organized weight-loss programs was 6% in men and 31% in women; current prevalence was 1% in men and 6% in women. The strongest correlate of dieting behavior was relative body weight. In logistic regression analyses, dieting tended to be associated positively with education and occupational status and, in men only, was more prevalent among those with a history of hypertension. Dieters reported lower food intakes than nondieters, but the two groups did not differ consistently in reported physical activity. Overall, dieting appears to be a pervasive behavioral U.S. phenomenon that may contribute in part to population differences in the prevalence of obesity.     

The origin and virulence of the 1918 "Spanish" influenza virus

The "Spanish" influenza pandemic of 1918-19 caused acute illness in 25-30 percent of the world's population and resulted in the death of up to an estimated 40 million people. Using fixed and frozen lung tissue of 1918 influenza victims, the complete genomic sequence of the 1918 influenza virus has been deduced. Sequence and phylogenetic analysis of the completed 1918 influenza virus genes shows them to be the most avian-like among the mammalian-adapted viruses. This finding supports the hypotheses that (1) the pandemic virus contains genes derived from avian-like influenza virus strains and that (2) the 1918 virus is the common ancestor of human and classical swine H1N1 influenza viruses. The relationship of the 1918 virus with avian influenza viruses is further supported by recent work in which the 1918 hemagglutinin (HA) protein crystal structure was resolved. Neither the 1918 hemagglutinin (HA) nor the neuraminidase (NA) genes possess mutations known to increase tissue tropicity that account for the virulence of other influenza virus strains like A/WSN/33 or the highly pathogenic avian influenza H5 or H7 viruses. Using reverse genetics approaches, influenza virus constructs containing the 1918 HA and NA on a modern human influenza virus background were lethal in mice. The complete 1918 virus was even more virulent in mice. The genotypic basis of this virulence has not yet been elucidated. The complete sequence of the non-structural (NS) gene segment of the 1918 virus was deduced and also tested for the hypothesis that enhanced virulence in 1918 could have been due to type I interferon inhibition by the NS1 protein. Results from these experiments suggest that in human cells the 1918 NS1 is a very effective interferon antagonist, but the 1918 NS1 gene does not have the amino acid change that correlates with virulence in the H5N1 virus strains identified in 1997 in Hong Kong. Sequence analysis of the 1918 pandemic influenza virus is allowing us to test hypotheses as to the origin and virulence of this strain. This information should help elucidate how pandemic influenza virus strains emerge and what genetic features contribute to virulence in humans.     

Commitment Shift during Organizational Upheaval: Physicians' Transitions from Private Practitioner to Employee

This longitudinal study examines the individual transition journeys of physicians as their private medical practices are acquired by a large integrated health care system. We test the proposition that transition patterns (trends in an individual's commitments to organization and profession over time) are a function of individual differences in years in profession and perceived organizational enabling characteristics (change involvement, openness to ideas, and work discretion). Three years of survey data were obtained from a panel of 48 physicians who transitioned through an organizational change process. Results challenge traditional assumptions that tenure reinforces commitment and cast doubt on the effectiveness of current medical school curricula in preparing medical graduates to practice in an administrative environment. In addition, results strongly suggest that enabling characteristics of organizational change are critical for compatibility between the organizational and professional attachments of transitioning physicians.     

Relational learning with and without awareness: Transitive inference using nonverbal stimuli in humans

Learning complex relationships among items and representing them flexibly have been shown to be highly similar in function and structure to conscious forms of learning. However, it is unclear whether conscious learning is essential for the exhibition of flexibility in learning. Successful performance on the transitive inference task requires representational flexibility. Participants learned four overlapping premise pairs (A > B, B > C, C > D, D > E) that could be encoded separately or as a sequential hierarchy (A > B > C > D > E). Some participants (informed) were told prior to training that the task required an inference made from premise pairs. Other participants (uninformed) were told simply that they were to learn a series of pairs by trial and error. Testing consisted of unreinforced trials that included the non-adjacent pair, B versus D, to assess capacity for transitive inference. Not surprisingly, those in the informed condition outperformed those in the uninformed condition. After completion of training and testing, uninformed participants were given a postexperimental questionnaire to assess awareness of the task structure. In contrast with expectations, successful performance on the transitive inference task for uninformed participants does not depend on or correlate with postexperimental awareness. The present results suggest that relational learning tasks do not necessarily require conscious processes.     

The Temporal Consistency of Personality Effects: Evidence from the British Household Panel Survey

Personality traits have been posited to function as stable influences on political attitudes and behavior. Although personality traits themselves exhibit high levels of temporal stability, it is not yet known whether the effects of these traits are marked by comparable temporal consistency. To address this question, this research note examines data from Wave 13 (2003–2004), Wave 15 (2005–2006) and Wave 17 (2007–2008) of the British Household Panel Survey (BHPS). Twenty‐seven behavioral and 14 attitudinal dependent variables are studied. Consistency of effects is gauged via a series of multilevel models in which personality effects are permitted to vary by year. High levels of temporal consistency are observed for personality traits as represented by the Big Five framework.     

Are Workplace Friendships a Mixed Blessing? Exploring Tradeoffs of Multiplex Relationships and their Associations with Job Performance

Theory and research note the ubiquity of multiplex workplace friendships—multifaceted relationships that superimpose friendship with work‐focused interactions—but it is unclear how they compel or hinder job performance. In a study of insurance company employees (n = 168), we found that the number of multiplex workplace friendships in one's social network is positively associated with supervisor ratings of job performance. However, we also found that there is a negative indirect effect on job performance through emotional exhaustion, which is offset, in part, through enhanced positive affect. Results of a second study of restaurant and retail sales employees (n = 182) provide greater insight into the positive and negative effects of multiplex workplace friendships. Specifically, these relationships enhanced job performance through trust but detracted from job performance through maintenance difficulty. Collectively, our results illustrate that having a large number of multiplex friendships at work is a mixed blessing. Although the provision and restoration of resources fostered by multiplex relationships benefits employee job performance, these benefits are muted somewhat by the personal resources they deplete.