Novel investigation methods in Computational Social Dynamics and Complex Systems

In this thesis the evolution of the techno-social systems analysis methods will be reported, through the explanation of the various research experience directly faced. The first case presented is a research based on data mining of a dataset of words association named Human Brain Cloud: validation will be faced and, also through a non-trivial modeling, a better understanding of language properties will be presented. Then, a real complex system experiment will be introduced: the WideNoise experiment in the context of the EveryAware european project. The project and the experiment course will be illustrated and data analysis will be displayed. Then the Experimental Tribe platform for social computation will be introduced . It has been conceived to help researchers in the implementation of web experiments, and aims also to catalyze the cumulative growth of experimental methodologies and the standardization of tools cited above. In the last part, three other research experience which already took place on the Experimental Tribe platform will be discussed in detail, from the design of the experiment to the analysis of the results and, eventually, to the modeling of the systems involved. The experiments are: CityRace, about the measurement of human traffic-facing strategies; laPENSOcosì, aiming to unveil the political opinion structure; AirProbe, implemented again in the EveryAware project framework, which consisted in monitoring air quality opinion shift of a community informed about local air pollution. At the end, the evolution of the technosocial systems investigation methods shall emerge together with the opportunities and the threats offered by this new scientific path.

Caregivers' Social Capital and Satisfaction with their Children's Service Providers

The authors examine children's access to and caregiver's satisfaction with organizations that provide leisure time activities for children on Saturdays. The authors argue that access and satisfaction are a function of familie's financial, cultural and social capital. Using data on 1,036 households in the Phoenix metropolitan area in 2003-04, the authors found that families' financial and cultural capital affected whether or not children participate din activities organized by organizations, but family ties to the organization directly (e.g., either worked there, volunteered, donated) resulted in caregivers being more satisfied with the services. The authors also found that the benefits of network closure (caregivers knowing the parents of other children on site) were greater the riskier the activities of the child (e.g., sports or cheerleading). Contrary to the authors expectations, having family or friends in the area did not affect caregiver's satisfaction with the child's provider.

Group Stereotypes and The Self: How Social Status and Interaction Expectation Affect Self-Stereotyping

This study examined how ingroup status affects the tendency for people to internalize ingroup stereotypes (i.e. self-stereotype) when expecting to interact with another individual who holds stereotypic views of them. Past research has demonstrated that people self-stereotype when they want to affiliate with another individual who holds stereotypic views of them. By self-stereotyping, individuals create a common bond or shared set of beliefs with the other individual. This line of research has not yet examinedif there are any moderators in the relationship between affiliation motivation and self-stereotyping. However, there is reason to believe that members of lower-status groups are more likely to feel the need to create this common bond through self-stereotyping because 1) they identify more closely with their social group, 2) their group identity is more salient 3) they are more aware of the expectations of others, 4) and they care more about the quality of an interaction with a member from a higher-status group. For this experiment, I recruited twenty-seven members of Alpha Chi Omega andtwenty-eight members of Delta Gamma, two sororities that are perceived to be middle-ranked (as determined by a pre-test survey). Upon arriving to the study, half the participants were informed that they would be interacting with a member of Kappa Kappa Gamma, a higher-ranked sorority (as determined by a pre-test survey) and half the participants were informed that they would be interacting with a member of a Chi Omega, a lower-ranked sorority (as determined by a pre-test survey). Participants were also informed that this partner held stereotypic views of their (i.e. the participant’s)sorority. After, participants were given the Self-Stereotyping Measure in which they rated how well sixteen characteristics described themselves. The results of the series of analyses performed on participants’ ratings on the Self-Stereotyping Measure indicated that when expecting to interact with another individual, members of low-status groups self-stereotype more than members of high-statusgroups and those who do not expect to interact. Furthermore, unexpectedly, among members of high-status groups, those who expected to interact with a member of a low-status group self-stereotyped less than those who did not expect to interact. Thus, this research provides support for the hypothesis that group status is a moderator in the relationship between self-stereotyping and affiliation motivation.

Depressive symptoms, perceived social support, and prothrombotic measures in patients with venous thromboembolism

Psychosocial factors have been associated with both a prothrombotic state and an increased risk of venous thromboembolism (VTE). We examined the relation of depressive symptoms and social support with D-dimer, an integrative measure of enhanced coagulation activity, and several additional prothrombotic measures in patients with VTE.

Mutagenesis and computer modeling studies of a GPCR conserved residue W5.43(194) in ligand recognition and signal transduction for CB2 receptor

W5.43(194), a conserved tryptophan residue among G-protein coupled receptors (GPCRs) and cannabinoid receptors (CB), was examined in the present report for its significance in CB2 receptor ligand binding and adenylyl cyclase (AC) activity. Computer modeling postulates that this site in CB2 may be involved in the affinity of WIN55212-2 and SR144528 through aromatic contacts. In the present study, we reported that a CB2 receptor mutant, W5.43(194)Y, which had a tyrosine (Y) substitution for tryptophan (W), retained the binding affinity for CB agonist CP55940, but reduced binding affinity for CB2 agonist WIN55212-2 and inverse agonist SR144528 by 8-fold and 5-fold, respectively; the CB2 W5.43(194)F and W5.43(194)A mutations significantly affect the binding activities of CP55940, WIN55212-2 and SR144528. Furthermore, we found that agonist-mediated inhibition of the forskolin-induced cAMP production was dramatically diminished in the CB2 mutant W5.43(194)Y, whereas W5.43(194)F and W5.43(194)A mutants resulted in complete elimination of downstream signaling, suggesting that W5.43(194) was essential for the full activation of CB2. These results indicate that both aromatic interaction and hydrogen bonding are involved in ligand binding for the residue W5.43(194), and the mutations of this tryptophan site may affect the conformation of the ligand binding pocket and therefore control the active conformation of the wild type CB2 receptor. W5.43(194)Y/F/A mutations also displayed noticeable enhancement of the constitutive activation probably attributed to the receptor conformational changes resulted from the mutations.