Negative affect as a mediator between body dissatisfaction and extreme weight loss and muscle gain behaviors

Negative affect has been found to mediate the relationship between body dissatisfaction and bulimia. However, it is unknown if this relationship also applies to disordered eating, excessive exercise and strategies to increase muscle for men or women. The aim of this study was to investigate whether negative and positive affect mediate the relationship between body dissatisfaction, and these body change strategies. Respondents were 93 men and 97 women (age range: 18-25 years), who completed measures of body dissatisfaction, positive and negative affect and body change strategies to lose weight or increase muscles. Body dissatisfaction was associated with strategies to lose weight, dietary restraint and bulimia for both genders. Negative affect mediated the relationship between dissatisfaction with muscles and strategies to lose weight, dietary restraint and bulimia for women only. The results confirm previous findings related to the association between negative affect and disordered eating for women. They also demonstrate the need to further investigate the impact of negative affect on body change strategies, particularly among men, and those strategies related to increasing muscles.

Sex-role traits and the comorbidity of symptoms of disordered eating and problem drinking

The symptoms of problem drinking and disordered eating were studied independently in relation to sex-role traits and also for evidence of comorbidity in a student sample of 217 women. The participants completed surveys that assessed positive and negative sex-role traits, reported drinking levels, alcohol dependence, problem drinking, bulimic symptoms, dietary restraint, and drive for thinness. Eating symptoms were related to both the negative and positive traits of Femininity, but self-descriptions involving negative traits (passivity, dependence, unassertiveness, etc.) showed the strongest relationship. High scores on identification with the traits typically labelled as Masculinity were related to drinking but there was an important difference between drinking per se (which was related to Positive Masculinity) and drinking found to be associated with drinking problems, which was related to Negative Masculinity (aggression, showing-off, rudeness, etc.). Feminine traits were also related to drinking. Low identification with the traits of Negative Femininity was associated with non-problem drinking, whereas low identification with the traits of Positive Femininity were associated with problem-related drinking. Young women who displayed comorbid symptoms described themselves by a high identification with the traits of both Negative Masculinity and Negative Femininity. It was argued that comorbidity reveals a more extreme form of the sex-role conflict previously described in relation to disordered control over both eating and drinking when considered independently.

Implications of accuracy, sensitivity, and variability of body size estimations to disordered eating

The current study was conducted to investigate the relationships between body size estimations and disordered eating symptomatology. The method of constant stimuli was used to derive three measures of self-perceived body size in 93 women: (1) accuracy of body size estimations (body image distortion); (2) sensitivity in discriminating body size within blocks of trials (body image sensitivity); and (3) variability in making body size estimations between blocks of trials (body image variability). Participants also completed measures of disordered eating. Although body image distortion correlated with dietary restraint and eating concern, body image variability accounted for additional variance in these variables, as well as variance in binge eating. The relationships involving body image variability were found to be mediated by body dissatisfaction and internalization of the thin ideal. Together, these results are consistent with the proposition that body image variability is a significant factor in disordered eating.

Corporate social responsibility : corporate reputation, business performance and public liability

Corporate Social Responsibility (CSR) may be viewed as a business strategy rather than a philanthropic concept. The increasing use of CSR as a corporate core strategy, in reaction to consumers‘ growing sentiments, can influence aggregate consumption and consumers‘ quality of life. As such, CSR would be of interest to the policy makers and may become subject to corporate governance and control mechanism. CSR is largely unregulated. Reliance on corporations‘ self-restraint and voluntary initiatives is inadequate to protect the society and avoid the disadvantages that may emerge from the potential deceptive practices in using a CSR strategy. This study investigates the evidence of economic benefits as incentives to corporations for using CSR. CSR is measured in terms of the firm‘s relationships with primary stakeholders. A model is constructed to identify the primary stakeholders and to estimate the association between CSR, corporate reputation and business performance. Policy implications of CSR are discussed.

Chronic stress alters the density and morphology of microglia in a subset of stress-responsive brain regions

The current study, in parallel experiments, evaluated the impact of chronic psychological stress on physiological and behavioural measures, and on the activation status of microglia in 15 stress-responsive brain regions. Rats were subjected, for 14 days, to two 30 min sessions of restraint per day, applied at random times each day. In one experiment the effects of stress on sucrose preference, weight gain, core body temperature, and struggling behaviour during restraint, were determined. In the second experiment we used immunohistochemistry to investigate stress-induced changes in ionized calcium-binding adaptor molecule-1 (Iba1), a marker constitutively expressed by microglia, and major histocompatibility complex-II (MHC-II), a marker often expressed on activated microglia, in a total of 15 stress-responsive nuclei. We also investigated cellular proliferation in these regions using Ki67 immunolabelling, to check for the possibility of microglial proliferation. Collectively, the results we obtained showed that chronic stress induced a significant increase in anhedonia, a decrease in weight gain across the entire observation period, a significant elevation in core body temperature during restraint, and a progressive decrease in struggling behaviour within and over sessions. With regard to microglial activation, chronic stress induced a significant increase in the density of Iba1 immunolabelling (nine of 15 regions) and the number of Iba1-positive cells (eight of 15 regions). Within the regions that exhibited an increased number of Iba1-positive cells after chronic stress, we found no evidence of a between group difference in the number of MHC-II or Ki67 positive cells. In summary, these results clearly demonstrate that chronic stress selectively increases the number of microglia in certain stress-sensitive brain regions, and also causes a marked transition of microglia from a ramified-resting state to a non-resting state. These findings are consistent with the view that microglial activation could play an important role in controlling and/or adapting to stress.

Opposing roles for medial and central amygdala in the initiation of noradrenergic cell responses to a psychological stressor

Psychological stressors trigger the activation of medullary noradrenergic cells, an effect that has been shown to depend upon yet-to-be-identified structures located higher in the brain. To test whether the amygdala is important in this regard, we examined the effects of amygdala lesions on noradrenergic cell responses to restraint, and also looked at whether any amygdala cells that respond to restraint project directly to the medulla. Ibotenic acid lesions of the medial amygdala completely abolished restraint-induced Fos expression in A1 and A2 noradrenergic cells. In contrast, lesions of the central amygdala actually facilitated noradrenergic cell responses to restraint. Tracer deposits in the dorsomedial (but not ventrolateral) medulla retrogradely labelled many cells in the central nucleus of the amygdala, but none of these cells expressed Fos in response to restraint. These data suggest for the first time that the medial amygdala is critical to the activation of medullary noradrenergic cells by a psychological stressor whereas the central nucleus exerts an opposing, inhibitory influence upon noradrenergic cell recruitment. The initiation of noradrenergic cell responses by the medial amygdala does not involve a direct projection to the medulla. Accordingly, a relay through some other structure, such as the hypothalamic paraventricular nucleus, warrants careful consideration.

Stressor categorization : acute physical and psychological stressors elicit distinctive recruitment patterns in the amygdala and in medullary noradrenergic cell groups

It has been hypothesized that the brain categorizes stressors and utilizes neural response pathways that vary in accordance with the assigned category. If this is true, stressors should elicit patterns of neuronal activation within the brain that are category-specific. Data from previous immediate–early gene expression mapping studies have hinted that this is the case, but interstudy differences in methodology render conclusions tenuous. In the present study, immunolabelling for the expression of c-fos was used as a marker of neuronal activity elicited in the rat brain by haemorrhage, immune challenge, noise, restraint and forced swim. All stressors elicited c-fos expression in 25–30% of hypothalamic paraventricular nucleus corticotrophin-releasing-factor cells, suggesting that these stimuli were of comparable strength, at least with regard to their ability to activate the hypothalamic–pituitary–adrenal axis. In the amygdala, haemorrhage and immune challenge both elicited c-fos expression in a large number of neurons in the central nucleus of the amygdala, whereas noise, restraint and forced swim primarily elicited recruitment of cells within the medial nucleus of the amygdala. In the medulla, all stressors recruited similar numbers of noradrenergic (A1 and A2) and adrenergic (C1 and C2) cells. However, haemorrhage and immune challenge elicited c-fos expression in subpopulations of A1 and A2 noradrenergic cells that were significantly more rostral than those recruited by noise, restraint or forced swim. The present data support the suggestion that the brain recognizes at least two major categories of stressor, which we have referred to as ‘physical’ and ‘psychological’. Moreover, the present data suggest that the neural activation footprint that is left in the brain by stressors can be used to determine the category to which they have been assigned by the brain.

Restrained eaters consume more food only if they are impulsive and male

This study utilised the preload paradigm to evaluate whether dietary restraint, impulsivity, or their interaction significantly predicts heightened food consumption among male and/or female participants. Following a high calorie preload, 79 participants aged 18 to 40 (53 females and 26 males) completed a deceptive taste test and questionnaires measuring restraint and impulsivity levels. A series of hierarchical regressions were run, controlling for self-rated hunger levels. A significant negative association between level of restraint and food consumption post-preload was found for males, but this relationship was not significant for female participants. The hypothesis that impulsivity would directly predict heightened food consumption was not supported for either gender. However, impulsivity was found to significantly moderate the relationship between restraint and food intake in the male sample, but not the female, providing partial support for this hypothesis. Potential reasons for this gender-specific interaction effect of impulsivity and restraint for food consumption are discussed. More broadly, present findings highlight the need for further consideration of the role of impulsivity in undermining food intake of restrained eaters. Future research should also consider how preload effects may differ across gender.

Understanding the link between body image and binge eating: a model comparison approach

Purpose
The present study tests several competing, explanatory models—dual pathways, escape from awareness, and objectification theory—for the established link between body dissatisfaction and binge eating.

Methods
408 women aged between 18 and 40 years completed a survey designed to assess contributions of proposed mediators (dietary restraint and negative affect from the dual pathway model, self-distraction from the escape from awareness model, and interoceptive deficits from objectification theory) for the body dissatisfaction–binge eating relationship.

Results
Although mediation analyses supported the dual pathway model and objectification theory when tested separately, the dual pathway model most strongly predicted the body dissatisfaction–binge eating relationship. Both model-implied mediators (dietary restraint and negative affect) made significant unique contributions, accounting for roughly one-quarter of the shared variance between body dissatisfaction and binge eating when tested separately from other mediators. Improvements in variance explained were negligible once other proposed mediators were included in a test of models combined.

Conclusions
Collectively, these findings suggest the superiority of the dual pathway model over objectification theory and the escape model, but the remaining unaccounted for covariance suggests need to consider alternative mechanisms that may also account for the relationship between body dissatisfaction and binge eating.

Understanding the link between body dissatisfaction and binge eating: a model comparison approach

 This thesis explored the association between body dissatisfaction and binge eating by comparing three competing theoretical frameworks. Study I utilised a cross-sectional design and collectively these findings suggest the superiority of the dual pathway model (dietary restraint and negative affect) over the objectification theory and the escape model. The purpose of Study II was then to extend on the findings from Study I by further examining in real-time the model/theory that most strongly explained the body dissatisfaction-binge eating relationship. Participants were prompted at random intervals seven times daily across the course of a week to self-report their state body dissatisfaction, current mood experiences, and eating practices. Results revealed that negative mood, but not dietary restraint, significantly mediated the state body dissatisfaction-binge eating relationship. These results highlight that the dual pathway model is robust, but raise the possibility that the dietary restraint path in the model is not well operationalized. In light of the non-significant mediating effect of dietary restraint, this led the researcher to identify various modeling alternatives to further understand the mediating influences of the pathways of negative affect and dietary restraint.

Effects of physical and chemical immobilization on hematologic and biochemical variables in captive brown brocket deer (Mazama gouazoubira)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Exposure to chronic stress increases the locomotor response to cocaine and the basal levels of corticosterone in adolescent rats

Repeated exposure to stress results in augmentation in the locomotor response to psychostimulant drugs. We investigated the locomotor response to a novel environment or cocaine [ 10 mg/kg, intraperitoneally (i.p.)] and basal corticosterone levels in male adolescent rats exposed to chronic restraint or variable stress. Animals in the chronic restraint group were restrained for 1 hour daily. The chronic variable stress protocol consisted of exposure to different stressors twice a day in random order. Chronic restraint and variable stress regimens began simultaneously on postnatal day (P) 25 and were applied for 10 days. During this period the control group was left undisturbed except for cleaning the cages. Three days after the last exposure to stress, cocaine- and novelty-induced locomotion were recorded in an activity cage. Plasma corticosterone levels were determined in a subset of stress and control animals. Exposure to both chronic restraint and variable stress increased cocaine- induced locomotion and basal corticosterone plasma levels, while no change was observed in the response to a novel environment. Moreover, rats exposed to variable stress displayed the greatest locomotor response following a challenge dose with cocaine when compared to control and chronic restraint stress groups. This observation indicates that the stress regimen is relevant to the degree of stress-induced sensitization to cocaine.

The fiscal impact of trade liberalization and commodity price fluctuation: the case of Dominican Republic, 1980-1998

Includes bibliography

Clutch-size adjustments and skew models: effects on reproductive partitioning and group stability

Reproductive skew theory seeks to integrate social and ecological factors thought to influence the division of reproduction among group-living animals. However, most reproductive skew models only examine interactions between individuals of the same sex. Here, we suggest that females can influence group stability and conflict among males by modifying their clutch size and may do so if they benefit from the presence of subordinate male helpers or from reduced conflict. We develop 3 models, based on concessions-based, restraint, and tug-of-war models, in which female clutch size is variable and ask when females will increase their clutch size above that which would be optimal in the absence of male-male conflict. In concessions-based and restraint models, females should increase clutch size above their optima if the benefits of staying for subordinate males are relatively low. Relatedness between males has no effect on clutch size. When females do increase clutch size, the division of reproduction between males is not influenced by relatedness and does not differ between restraint and concessions-based models. Both of these predictions are in sharp contrast to previous models. In tug-of-war models, clutch size is strongly influenced by relatedness between males, with the largest clutches, but the fewest surviving offspring, produced when males are unrelated. These 3 models demonstrate the importance of considering third-party interests in the decisions of group-living organisms.

Regulation of woody plant development by gibberellin catabolic and signaling genes

Gibberellin (GA) is a growth promoting hormone implicated in regulating a diversity of plant processes. This dissertation examines the role of GA metabolic and signaling genes in woody plant growth and development. Transgenic modifications, expression analysis, physiological/biochemical assays, biometric measurements and histological analysis were used to understand the regulatory roles these genes play in the model woody plant, Populus. Our results highlight the importance of GA regulatory genes in woody perennial growth, including: phenology, wood formation, phenotypic plasticity, and growth/survival under field conditions. We characterize two putative Populus orthologs of the SHORT INTERNODES (SHI) gene from Arabidopsis, a negative regulator of GA signaling. RNAi-mediated suppression of Populus SHI-like genes increased several growth-related traits, including extent of xylem proliferation, in a dose-dependent manner. Three Populus genes, sharing sequence homology to the positive regulator of GA signaling gene PHOTOPERIOD-RESPONSIVE 1 (PHOR1) from Solanum, are up-regulated in GA-deficient and insensitive plants suggesting a conserved role in GA signaling. We demonstrate that Populus PHOR1-like genes have overlapping and divergent function(s). Two PHOR1-like genes are highly expressed in roots, predominantly affect root growth (e.g., morphology, starch quantity and gravitropism), and induced by short-days (SD). The other PHOR1-like gene is ubiquitously expressed with a generalized function in root and shoot development. The effects of GA catabolic and signaling genes on important traits (e.g., adaptive and productivity traits) were studied in a multi-year field trial. Transgenics overexpressing GA 2-oxidase (GA2ox) and DELLA genes showed tremendous variation in growth, form, foliage, and phenology (i.e., vegetative and reproductive). Observed gradients in trait modifications were correlated to transgene expression levels, in a manner suggesting a dose-dependent relationship. We explore GA2ox and DELLA genes involvement in mediating growth responses to immediate short-term drought stress, and SD photoperiods, signaling prolonged periods of stress (e.g., winter bud dormancy). GA2ox and DELLA genes show substantial up-regulation in response to drought and SDs. Transgenics overexpressing homologs of these genes subjected to drought and SD photoperiods show hypersensitive growth restraint and increased stress resistances. These results suggest growth cessation (i.e., dormancy) in response to adverse conditions is mediated by GA regulatory genes.