Are personalities genetically determined? Inferences from subsocial spiders.

BACKGROUND:Recent research has revealed that polymorphic behavioral strategies shape intra-and interspecific interactions and contribute to fitness in many animal species. A better understanding of the proximate mechanisms underlying these behavioral syndromes will enhance our grasp this phenomenon. Spiders in the genus Anelosimus exhibit inter-individual behavioral variation on several axes: individuals have consistent responses to stimuli (e.g. bold vs. shy individuals) and they are subsocial (exhibiting extended maternal care and sibling cooperation) across most of their range, but they sometimes form permanent social groups in northern temperate regions. Here, we seek genetic variants associated with boldness and with social structure in a socially polymorphic population of the spider Anelosimus studiosus. We also develop preliminary genomic resources, including a genome assembly and linkage map, that support this and future genomic research on this group. RESULTS:Remarkably, we identify a small genomic scaffold (~ 1200 bp) that harbors seven single nucleotide polymorphisms (SNPs) associated with boldness. Moreover, heterozygotes are less common than expected based on Hardy-Weinberg equilibrium, suggesting that either assortative mating or selection against heterozygotes may be occurring in this system. We find no loci significantly associated with social organization. Our draft genome assembly allows us to localize SNPs of interest in this study and to carry out genetic comparisons with other published genomes, although it remains highly fragmented. CONCLUSIONS:By identifying a locus associated with a well-studied animal personality trait, this study opens up avenues for future research to link behavioral studies of animal personality with genotype and fitness

Insights from the study of complex systems for the ecology and evolution of animal populations

D.N.F. thanks Jack W. Bradbury and Sandra L. Vehrencamp for writing the article that originally stimulated his thoughts in this area. The authors are also grateful to Simon Denomme-Brown, Gustavo Betini and Elizabeth Hobson for reviewing drafts of this article, and Andrew G. McAdam for allowing D.N.F. to pursue this project despite employing him to study squirrels. Four anonymous reviewers provided useful comments that helped improve the manuscript. We have no conflicting interests.Peer reviewedPublisher PD

Evidence of social niche construction: persistent and repeated social interactions generate stronger personalities in a social spider.

While there are now a number of theoretical models predicting how consistent individual differences in behaviour may be generated and maintained, so far, there are few empirical tests. The social niche specialization hypothesis predicts that repeated social interactions among individuals may generate among-individual differences and reinforce within-individual consistency through positive feedback mechanisms. Here, we test this hypothesis using groups of the social spider Stegodyphus mimosarum that differ in their level of familiarity. In support of the social niche specialization hypothesis, individuals in groups of spiders that were more familiar with each other showed greater repeatable among-individual variation in behaviour. Additionally, individuals that were more familiar with each other exhibited lower within-individual variation in behaviour, providing one of the first examples of how the social environment can influence behavioural consistency. Our study demonstrates the potential for the social environment to generate and reinforce consistent individual differences in behaviour and provides a potentially general mechanism to explain this type of behavioural variation in animals with stable social groups

Sex-specific roles of cellular inflammation and cardiometabolism in obesity-associated depressive symptomatology.

BackgroundObesity and depression are complex conditions with stronger comorbid relationships among women than men. Inflammation and cardiometabolic dysfunction are likely mechanistic candidates for increased depression risk, and their prevalence differs by sex. Whether these relationships extend to depressive symptoms is poorly understood. Therefore, we analyzed sex in associations between inflammation and metabolic syndrome (MetS) criteria on depressive symptomatology. Specifically, we examined whether sex positively moderates the relationship between depressive symptoms and inflammation among women, and whether MetS has parallel effects among men.MethodsDepressive symptoms, MetS, and inflammation were assessed in 129 otherwise healthy adults. Depressive symptoms were assessed using Beck Depression Inventory (BDI-Ia). Monocyte inflammation regulation (BARIC) was quantified using flow cytometry measurement of TNF-α suppression by β-agonist. Moderation effects of sex on associations between BARIC, MetS criteria, and BDI were estimated using two-way ANOVA and linear regression, adjusting for BMI, and by sex subgroup analyses.ResultsObese individuals reported more depressive symptoms. Sex did not formally moderate this relationship, though BDI scores tended to differ by BMI among women, but not men, in subgroup analysis. Poorer inflammation control and higher MetS criteria were correlated with somatic depressive symptoms. Sex moderated associations between MetS criteria and somatic symptoms; among men, MetS criteria predicted somatic symptoms, not among women. Subgroup analysis further indicated that poorer inflammation control tended to be associated with higher somatic symptoms in women.ConclusionsThese results indicate that obesity-related inflammation and MetS factors have sex-specific effects on depressive symptoms in a non-clinical population. Although pathophysiological mechanisms underlying sex differences remain to be elucidated, our findings suggest that distinct vulnerabilities to depressive symptoms exist between women and men, and highlight the need to consider sex as a key biological variable in obesity-depression relationships. Future clinical studies on comorbid obesity and depression should account for sex, which may optimize therapeutic strategies

Individual and Group Performance Suffers from Social Niche Disruption.

The social niche specialization hypothesis predicts that animal personalities emerge as a result of individuals occupying different social niches within a group. Here we track individual personality and performance and collective performance among groups of social spiders where we manipulated the familiarity of the group members. We show that individual personalities, as measured by consistent individual differences in boldness behavior, strengthen with increasing familiarity and that these personalities can be disrupted by a change in group membership. Changing group membership negatively impacted both individual and group performance. Individuals in less familiar groups lost weight, and these groups were less successful at performing vital collective tasks. These results provide a mechanism for the evolution of stable social groups by demonstrating that social niche reestablishment carries a steep cost for both individuals and groups. Social niche specialization may therefore provide a potential first step on the path toward more organized social systems

Pasture Weaning and Forage Barley to Extend the Grazing Season for Replacement Heifers

In a two-year study at the SDSU Cow/Calf Teaching and Research Unit, Brookings, SD, heifer calves were allotted to two weaning management treatments in early October at an average age of 202 days. The pasture-weaned group was separated from their dams and grazed grass pasture across the fence from their dams for two weeks. Then, until early December, they grazed “Robust” barley (forage type) that had been no-till planted into oat stubble in early August. The drylot-weaned group was fed a traditional weaning diet of grass hay, corn, and protein supplement from weaning until early December. The effect of management on heifer weight gain depended on year. In the first year, pasture-weaned heifers gained more than the drylot group during the first two weeks after weaning. Due to less than ideal pasture conditions in the second year, the drylot group gained more than the pasture weaned group for two and four weeks after weaning. In both years, gains from weaning to the end of the grazing period in December and to the following April were similar between management systems. Pasture weaning appeared to cause less stress for both cows and calves, but no differences in disease symptoms were observed. Antibody titers for IBR, BVD type 1 and BVD type 2 were determined at weaning and two and four weeks after weaning to measure the development of immunity from vaccinations administered two months prior to and at weaning. At two weeks after weaning in the second year of the study, antibody titer for BVD type 1 was greater for the drylot group than the pasture-weaned group. By four weeks after weaning the pasture-weaned heifers had antibody titers similar to the drylot group. The results of this study indicate that pasture weaning combined with small grain pasture to extend the grazing system can be an effective alternative for managing replacement heifers compared to a traditional drylot weaning system

Bilateral negotiation in a multi-agent supply chain system

A supply chain is a set of organizations directly linked by flows of services from suppliers to customers. Supply chain activities range from the ordering and receipt of raw materials to the production and distribution of finished goods. Supply chain management is the integration of key activities across a supply chain for the purposes of building competitive infrastructures, synchronizing supply with demand, and leveraging worldwide logistics. This paper addresses the challenges created by supply chain management towards improving long-term performance of companies. It presents a multi-agent supply chain system composed of multiple software agents, each responsible for one or more supply chain activities, and each interacting with other agents in the execution of their responsibilities. Additionally, this paper presents the key features of a negotiation model for software agents. The model handles bilateral multi-issue negotiation and incorporates an alternating offers protocol, a set of logrolling strategies, and a set of negotiation tactics

"She's Just a Normal Girl": ESPN the Magazine's Body Issue and the Framing of Women Athletes

Although the number of women participating in organized sport has drastically increased since the passage of Title IX, sport media has not necessarily reflected this change. As well as being underrepresented in sport media, women athletes are also portrayed in gender biased ways. When examining photographic media, many studies investigate Sports Illustrated�s Swimsuit Issue; however, the present study argues that using this magazine is methodologically flawed. Therefore, I explore an emergent source�ESPN the Magazine�s Body Issue�in order to determine how women are represented in this magazine. Using Goffman�s (1974) framing theory and (1979) Gender Advertisements, as well as Schipper�s (2007) extension of hegemonic femininity, I utilized content analytic methods to analyze all editions of the annual Body Issue from 2009 � 2014. In total, I studied 143 athletes represented in 146 images, as well as the captions which accompanied these images. Results uncovered that, although women are more highly represented than men in the Body Issue, they are still presented using hegemonically feminine frames. While the Body Issue does occasionally present women in ways which challenge the hegemonic gender structure, these instances are few. Contributions of this study to the body of literature regarding sport media strengthen the suggestion that sport media plays a role in both producing and reproducing the hegemonic gender structure.Sociolog