Categorical Abstract Algebraic Logic: Equivalent Institutions

A category theoretic generalization of the theory of algebraizable deductive systems of Blok and Pigozzi is developed. The theory of institutions of Goguen and Burstall is used to provide the underlying framework which replaces and generalizes the universal algebraic framework based on the notion of a deductive system. The notion of a term -institution is introduced first. Then the notions of quasi-equivalence, strong quasi-equivalence and deductive equivalence are defined for -institutions. Necessary and sufficient conditions are given for the quasi-equivalence and the deductive equivalence of two term -institutions, based on the relationship between their categories of theories. The results carry over without any complications to institutions, via their associated -institutions. The -institution associated with a deductive system and the institution of equational logic are examined in some detail and serve to illustrate the general theory.     

Influence of strain rate on the orientation dependence of microstructure in nickel single crystals

The deformation microstructures of nickel single crystals (99.945 wt.%) during dynamic plastic deformation and quasi-static compression to a true strain of 0.20 were comparatively investigated. The deformation microstructures are orientation dependent, forming cell structure, slip plane aligned or not slip plane aligned extended boundaries. It is found that the orientation spread decreases, remains unchanged and becomes enhanced when loading along 〈0?0?1〉, 〈0?1?1〉 and 〈1?1?1〉, respectively, as strain rate increases.     

A longitudinal person-centred approach to the job demands-control model

We used a longitudinal design and a person-centred methodology to test the strain and learning hypotheses of the job demands–control model among Finnish employees (n = 926), who were followed-up at three time points covering a period of 2 years (2008–2010). First, we identified longitudinal subgroups in demands and control across three measurement points. Second, we examined how these subgroups differed in strain (job exhaustion) and motivation-related outcomes (vigour at work, work–family enrichment). Growth mixture modelling revealed four subgroups: “stable high strain”, “stable low strain”, “increasing control”, and “decreasing control”. The stable high- and low-strain subgroups also differed in the outcomes studied (exhaustion, work–family enrichment) as suggested by the demands–control model. The findings also suggest that job control is subject to changes over time and that these changes are likely to be associated with changes in employee outcomes. Malleability of job control should be kept in mind in job stress interventions, likewise the fact that some employees suffer from chronic job stress.     

Aspiration Strain and Mental Health: The Education‐Contingent Role of Religion

This study examines whether dimensions of religious involvement (i.e., perceived divine control, private religious practices, and religious social integration) buffer associations between aspiration strain and mental health outcomes (i.e., psychological distress, loneliness, and optimism). We also test three‐way interactions to determine whether the stress‐buffering effects of religious involvement are amplified among undereducated persons. We test our hypotheses with cross‐sectional survey data from Vanderbilt University's Nashville Stress and Health Study (2011–2014), a probability sample of non‐Hispanic white and black adults from Davidson County, Tennessee (n = 1,252). Results from multivariate regression models confirmed: (1) aspiration strain was positively associated with psychological distress and loneliness, and negatively associated with optimism; and (2) religious involvement attenuated these associations, but only for respondents with less than or equal to a high school education. We discuss the implications and limitations of our findings and outline avenues for future research.     

Genetic differences in the mouse defense test battery

The mouse defense test battery (MDTB) has been designed to examine anxiogenic- or anxiolytic-like properties of psychoactive drugs through effects on specific defensive behaviors. In the present study, the MDTB was used to evaluate the potential contribution of genetic factors to these behaviors. The data revealed pronounced differences in several defense reactions among four inbred strains (BALB/c, C57BL/6, CBA, DBA/2) and one outbred (Swiss) mouse line. Thus, when subjects were introduced into the apparatus, Swiss and C57BL/6 displayed the highest levels of horizontal and vertical activities, while BALB/c and DBA/2 mice showed intermediate and CBA low activity rates. When subjects were chased by the rat, C57BL/6 mice used flight as the dominant defense strategy, while the defensive responses of BALB/c, C57BL/6, and DBA/2 mice consisted of flight reactions and risk assessment activities. However, when flight or escape was not possible, risk assessment became the predominant feature of the defense repertoire in the C57BL/6 mice. When defensive threat/attack behaviors were required, Swiss, BALB/c, DBA/2, and C57BL/6 mice showed very similar reactions in terms of the magnitude of the responses observed. CBA mice were poorly defensive in all these test situations. Finally, after the rat was removed from the test apparatus, Swiss, DBA/2, and C57BL/6 mice displayed more vertical activities than BALB/c mice. These latter, however, showed an increased level of ambulation compared to the activity recorded before the rat exposure. Together, these findings indicate that genetic factors contribute to defensive behaviors in this animal model of anxiety. The different behavioral profiles displayed by the strains used here may provide the means to obtain a better insight into the neurobehavioral mechanisms involved in anxiety-related disorders. Aggr. Behav. 23:19–31, 1997. © 1997 Wiley-Liss, Inc.     

Intrasession and intersession habituation in mice: From inbred strain variability to linkage analysis

When placed in a novel environment, mice tend to explore for a period of time, and then reduce the level of exploration. This reduction in locomotor or exploratory behavior is known as habituation and can occur within a single session or across sessions, respectively, termed intrasession and intersession habituation. Recent research indicates that there is a genetic component to habituation behavior and that some of the genes involved differ between the two types of habituation. The genetic evidence also suggests that intrasession habituation and intersession habituation are measuring somewhat different conceptual entities and with more such evidence may eventually help us understand the different pathways involved. Some of the genetic methods and tools used to unravel the roles of specific genes in both types of habituation are outlined here, with examples from the literature, as well as new data, to illustrate that this seemingly simple behavior is actually very complicated in terms of genetics. Evidence to date suggests that a number of genetic regions play roles in one or both types of habituation, and further research will be necessary to determine the specific genes involved.     

Social support,strain, and glycemic control: A path analysis

Social support and strain have been linked with many health outcomes. However, less is known about whether these psychosocial factors are associated with Type 2 diabetes risk. This study uses the Midlife in the United States (MIDUS) dataset to examine the relationship between social support and strain from friends, family members, and spouse/partners and blood hemoglobin A1c levels in married/cohabiting adults who have not been diagnosed with diabetes. In addition, health locus of control is examined as a possible mediator. The study's findings suggest that support from friends is negatively associated with HbA1c levels, indicating a relationship between better glycemic control and social support from friends, and an indirect association for spouse/partner support. A direct effect for internal health locus of control was also found.     

The Demand–Control model and target's reports of bullying at work: A test within Spanish and Belgian blue-collar workers

The present study explores whether Karasek's Job Demand–Control (JDC) model's strain hypothesis can be applied to target's reports of bullying at work in matched samples of Spanish and Belgian blue-collar workers. In the Spanish sample, results reveal a positive main effect of workload and a negative main effect of autonomy. The relationship between workload and bullying is particularly strong under the condition of low autonomy (i.e., interaction), in line with Karasek's strain hypothesis. In the Belgian sample, results show a positive main effect of workload and a significant workload–autonomy interaction effect in accordance with the strain hypothesis. In sum, high strain jobs associate with target's reports of bullying in both the Spanish and Belgian sample. Karasek's JDC model may accordingly be extended to target's reports of bullying as a form of social behavioural strain. These findings furthermore enhance research in the realm of bullying at work by introducing a well-established theoretical framework to account for the relationship between workload, autonomy, and target's reports of bullying.