Social comparison theory offers a useful conceptual framework to understand how mainstream American sociocultural values of appearance may shape the development of body image disturbance and eating disorders. Some experimental research demonstrates that women report significantly greater increases in negative affect and body image disturbance and decreases in self-esteem after viewing thin models than after viewing inanimate objects, normal-weight models, and overweight women. The main goal of this study was to investigate whether the effects of viewing thin models are influenced by the ethnicity of the observer and/or the ethnic and racial similarity of the model to the observer. In addition, the study tested the extent to which social comparison tendency, trait appearance evaluation, ethnic identity, and racial identity may moderate these effects. In study 1, women rated the race, attractiveness, and thinness of a group of ethnically diverse models. Study 2 assessed affect, self-esteem, and body image in Euro-American (n = 105), African-American (n = 91), and Latina (n = 111) women before and after viewing ethnically self-similar models, self-different models, or control images. Results indicated that ethnic similarity between model and participants influenced affect such that increased social comparison tendency in Latina participants predicted increased negative affect after viewing Latina models. Additionally, the type of media images viewed and proposed moderators influenced affect and body image. As predicted, positive appearance evaluation was more strongly associated with positive feelings about one’s weight after viewing models and, in African-American and Latina women, increased idealization of Whiteness was associated with decreased positive feelings regarding one’s weight after viewing White models. Unexpectedly, increased social comparison tendency was associated with increased positive affect after viewing African-American models whereas increased social comparison tendency was associated with less positive affect after viewing Latina models. Finally, independent of media exposure, African-American women reported higher appearance-based self-esteem and body image than Euro-American and Latina women and increased social comparison tendency, decreased positive appearance evaluation, decreased ethnic identity, and increased racial identity idealizing Whiteness were each associated with undesirable levels of self-esteem and body image. Clinical implications and directions for future research are provided.

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Although there have been only a few etiological studies that have examined the development and maintenance of body image in males, research fairly consistently reports that exposure and presumed comparison to images of ideal male bodies increases body dissatisfaction. Social comparison provides individuals with a mechanism by which to evaluate their body appearance to those around them. When individuals compare their bodies to those of others, they are attempting to gauge their standing or status relative to those around them, the results of which have inherent status implications. There is increasing empirical evidence that suggests perceived increases in status result in increased testosterone levels, whereas testosterone decreases when status is perceived as having been diminished. Thus, the core of the present study: can the process of comparing the appearance of one’s body to that of others affect the testosterone levels, body satisfaction, and mood of males? To examine the above research questions, a two-part study was designed. A pilot study was conducted with 117 male undergraduates primarily to examine the psychometrics of measures to be used in the main study. The measures appeared psychometrically sound and were thus used in the main study. In the main study, 129 male undergraduates were exposed to photographs of one of three male body types (i.e., lean/muscular, skinny, average) to determine whether or not exposure to the different body types differentially affected participants’ testosterone levels, body satisfaction, and mood. Results indicate that testosterone levels decreased over the course of the experiment in each of the three groups; however, the body type to which participants were exposed did not differentially affect participants’ testosterone levels. Body dissatisfaction was greater among participants who viewed lean/muscular bodies than those who viewed average bodies. Lastly, mood was not differentially affected by viewing different types of male bodies. Implications and possible explanations for these results are discussed.

Childhood cancer has obvious impacts on the children themselves, but also has impacts on their families and siblings. While studies have been conducted on the impacts of cancer on children and their parents, there has been limited consideration of the impacts of cancer on healthy siblings. Some studies have suggested that siblings of children with cancer are the most emotionally disregarded and distressed of all family members as a result of their sibling having cancer. Exposure to stress has a negative impact on the immune system and places siblings at risk for health problems. Thus, finding mechanisms to ameliorate stress are critical. Early intervention and treatment may serve as protective factors against risky behavior and lead to more normative child development and well-being. One method of improving the psychosocial adjustment of siblings of children with cancer has been through interventions such as camp experiences that include opportunities for campers to experience social support. There is a need to better understand the efficacy of intervention programs designed to reduce stress across a variety of settings. The focus of this study was if campers experience social support (emotional, informational, and instrumental) at a three and one-half day residential camp, and the elements of camp campers' identified as leading to social support. Participant observations of camp and semi-structured interviews with selected campers were used to help gain insights concerning the impact of the camp experience on siblings of children with cancer. Coding of responses was undertaken, which led to the identification of themes and subthemes. Findings provided a narrative description of how campers perceived social support. In addition, social comparison was identified as a critical mechanism for meeting camper's biological, physiological and behavioral needs. Overarching perceptions of campers were that people at camp were nice and staff was instrumental in facilitating universality and a cycle of reciprocity. Implications of this study suggest intentionally designed camps have the ability to impact a broad range of attitudes and behaviors. The study also supports theory of how structures and processes of social relationships work in relation to good health; and can be applied to a camp setting.

Social networking and social media technologies have greatly changed the way information is created and transmitted. Social media has made content contribution an efficient approach for individual brand building. With abundant user generated content and social networks, content consumers are constantly subject to social influence. Such social influence can be further utilized to encourage pro-social behavior. Chapter 1 examines the incentives for content contribution in social media. We propose that exposure and reputation are the major incentives for contributors. Besides, as more and more social media websites offer advertising-revenue sharing with some of their contributors, shared revenue provides an extra incentive for contributors who have joined revenue-sharing programs. We develop a dynamic structural model to identify a contributor's underlying utility function from observed contribution behavior. We recognize the dynamic nature of the content-contribution decision--that contributors are forward-looking, anticipating how their decisions impact future rewards. Using data collected from YouTube, we show that content contribution is driven by a contributor's desire for exposure, revenue sharing, and reputation and that the contributor makes decisions dynamically. Chapter 2 examines how social influence impact individuals' content consumption decisions in social network. Specifically, we consider social learning and network effects as two important mechanisms of social influence, in the context of YouTube. Rather than combining both social learning and network effects under the umbrella of social contagion or peer influence, we develop a theoretical model and empirically identify social learning and network effects separately. Using a unique data set from YouTube, we find that both mechanisms have statistically and economically significant effects on video views, and which mechanism dominates depends on the specific video type. Chapter 3 studies incentive mechanism to improve users' pro-social behavior based on social comparison. In particular, we aim to motivate organizations to improve Internet security. We propose an approach to increase the incentives for addressing security problems through reputation concern and social comparison. Specifically, we process existing security vulnerability data, derive explicit relative security performance information, and disclose the information as feedback to organizations and the public. To test our approach, we conducted a field quasi-experiment for outgoing spam for 1,718 autonomous systems in eight countries. We found that the treatment group subject to information disclosure reduced outgoing spam approximately by 16%. Our results suggest that social information and social comparison can be effectively leveraged to encourage desirable behavior. / text

Structural equation model (SEM) is a general approach to analyze multivariate data. It is a relatively comprehensive model and combines useful characteristics from many statistical approaches, thus enjoys a variety of advantages when dealing complex relationships. This report gives a brief introduction to SEM, focusing especially the comparison of SEM and OLS regression. A simple tutorial of how to apply SEM is also included with the introduction and comparison. SEM can be roughly seen as OLS regression added with features such as simultaneous estimation, latent factors and autocorrelation. Therefore, SEM enjoys a variety of advantages over OLS regression. However, it is not always the case that SEM will be the optimal choice. The biggest concern is the complexity of SEM, for simpler model will be preferable for researchers when the fitness is similar. Two simulation cases, one requires special features of SEM and one satisfies assumptions of OLS regression, are applied to illustrate the choice between SEM and OLS regression. A study using data from US life insurers in the year 1994 serves as a further illustration. The conclusion is when special features of SEM is required, SEM fits better and will be the better choice, while when OLS regression assumptions are satisfied, SEM and OLS regression will fit equally well, considering the complexity of SEM, OLS regression will be the better choice. / text

It is widely accepted that the educational system of universities has to provide an academic environment that may serve as a catalysts for high-technology start-ups. The academic tradition of entrepreneurship in German-speaking countries is very short. Until recently, fostering innovations and new product development through entrepreneurship has not been regarded as a primary task of universities. However, perspectives have changed in this respect, and there have been numerous attempts to enhance the role of university graduates as founders of innovative businesses. In this paper, we compare the entrepreneurial intentions of students at two German-speaking universities (the Vienna University of Economics and Business Administration and the University of Munich) with the corresponding results for a leading institution in this field: Massachusetts Institute of Technology (MIT). We find very distinct patterns of entrepreneurial spirit in these universities. The results also suggest that the lower level of founding intentions among students in Munich and Vienna may be attributed to their less distinctive entrepreneurship education. This leaves a great deal of room for improvement. (author's abstract)

Inertial measurement units (IMUs) are used in a wide range of applications to estimate position, velocity, and attitude of vehicles. The high cost of tactical grade IMUs makes the low-cost microelectromechanical systems (MEMS) based IMUs appealing. These types of IMUs are less accurate, so to counteract this effect, multiple and different configurations should be used. The work presented here provides efficient and low cost solutions using different configurations of redundant (multiple) MEMS-IMU swarms, which increase the level of accuracy to potentially the order of that of a tactical IMU. Several configurations are presented and compared through different methods. / text

The purpose of this study was to examine the similarity of outcomes from three different treatment integrity (TI) methods, and to identify the method which best corresponded to the assessment of a child’s behavior. Six raters were recruited through individual contact via snowball sampling. A modified intervention component list and 19 video clips were derived from Stahr’s (2005) study, “An Intervention for Children with Autism Spectrum Disorders (ASD) who Have Food Selectivity.” The raters, randomly and evenly assigned to three dyads. Each dyad received an average of six hours training and reached 85% interobserver agreement (IOA) with a 0.60 kappa score. After training, each dyad watched 5 video clips per day and measured both the child’s behavior and TI. The percentages of IOA, kappas, and indices of dependability for assessment of the child’s behavior and TI were analyzed. The data revealed that all raters reached over 80% IOA and the whole interval (WI) and yes/no (Y/N) dyads reached .60 kappa, but the two raters in the Likert-type (LIK) dyad could not reach .60 kappa. The indices of dependability indicated that the six raters consistently observed and rated both the child’s behavior and TI, but there was a discrepancy in scores (i.e., percentages of TI) between the two raters in the two indirect measure dyads (i.e., Y/N and LIK). An analysis of the percentages of total variance showed that the two indirect TI methods may affect the discrepancy between the two raters’ rating scores. A comparison of the three different TI methods and correlation between the child’s behavior and TI were examined using the PASW Statistics 18 software program. There was no significant difference between the WI and the Y/N dyads, while the assessments from the LIK dyad indicated a significant difference from the other two dyads. Both the WI and the Y/N dyads showed correlations between the degree of the child’s behavior and the degree of TI, but there was no significant difference between the two correlation coefficients. Questions about reliability with the indirect TI measures suggest one should be careful in considering these results.

Candidate virulence genes were sought through the genetic analyses of two strains of Mycobacterium tuberculosis, one virulent, H37Rv, one attenuated, H37Ra. Derived from the same parent, H37, genomic differences between strains were first examined via two-dimensional DNA technologies: two-dimensional bacterial genome display, and bacterial comparative genomic hybridisation. The two-dimensional technologies were optimised for mycobacterial use, but failed to yield reproducible genomic differences between the two strains. Expression differences between strains during their infection of murine bone-marrow-derived macrophages were then assessed using Bacterial Artificial Chromosome Fingerprint Arrays. This technique successfully identified expression differences between intracellular M. tuberculosis H37Ra and H37Rv, and six candidate genes were confirmed via quantitative real-time PCR for their differential expression at 168 hours post-infection. Genes identified to be upregulated in the attenuated H37Ra were frdB, frdC, and frdD. Genes upregulated in the virulent H37Rv were pks2, aceE, and Rv1571. Further qPCR analysis of these genes at 4 and 96h post-infection revealed that the frd operon (encoding for the fumarate reductase enzyme complex or FRD) was expressed at higher levels in the virulent H37Rv at earlier time points while the expression of aceE and pks2 was higher in the virulent strain throughout the course of infection. Assessment of frd transcripts in oxygen-limited cultures of M. tuberculosis H37Ra and H37Rv showed that the attenuated strain displayed a lag in frdA and frdB expression at the onset of culture when compared to microaerophilic cultures of H37Rv and aerated cultures of H37Ra. Furthermore, inhibition of the fumarate reductase complex in intracellular bacteria resulted in a significant reduction of intracellular growth. Microarray technology was also applied in the expression analysis of intracellular bacteria at 168h post-infection. Forty-eight genes were revealed to be differentially expressed between the H37Ra and H37Rv strains, and a subset were further analysed via qPCR to confirm and validate the microarray data. phoP was expressed at a lower level in the attenuated M. tuberculosis H37Ra, whereas members of the phoPR regulon were up-regulated in the virulent H37Rv. Additionally, a group of genes (Rv3616c-Rv3613c) that may associate with the region of difference 1 were also up-regulated in the virulent H37Rv.