The organisational goals of social entrepreneurs: how social are they?

There is an increasing consensus among academics that the common denominator of ‘social entrepreneurs’ is their adherence to a ‘dominant social mission’. The extent to which social entrepreneurs actually adhere to socially oriented goals and values is largely taken for granted and treated as a black box. Building on established theoretical constructs, this paper develops a number of measures that can potentially contribute to our understanding of how ‘social’ social entrepreneurs really are. More specifically, we empirically test four potential measures of “social proclivity” in a well defined sample of social ventures, performing confirmatory factor analysis (CFA) (N~270). CFA points to high reliability and validity for the measures of each of the four constructs and supports the existence of a higher order construct “social proclivity”. Further, results show that social entrepreneurs display strong social as well as economic motives, providing an empirical base for actually capturing the dual-bottom line that characterises these enterprises

Searches for galaxies at z > 4 through Lyman-limit imaging

We present preliminary results of a search for galaxies at z>4 through Lyman-limit imaging of the fields of known high-redshift radio-galaxies. Objects were selected by means of their broad-band colours, and spectroscopy of candidate objects in one of the fields has been performed through multi-slit spectroscopy at the 4.2m William Herschel Telescope. These spectra show some of the first z>4 galaxies to be identified using the Lyman break technique.Comment: 4 pages, LaTeX, requires paspconf.sty (included). To appear in Proceedings of "The Young Universe", Rome Observatory, Sep 29 - Oct 3 199

Social and economic proclivity of social entrepreneurs : dimensions, measurement and validation

Social entrepreneurs are argued to adhere to a ‘dominant social goal’, using revenue streams from the market as a means to support their mission.. However, the extent to which social entrepreneurs actually adhere to socially or economically oriented goals is largely treated as a black box in the literature. This paper develops and validates measures for gaining insight in the relative importance of the “social” and “economic” proclivity of social entrepreneurs, conceptualizing them as two aggregated constructs with three dimensions: work values, organizational identity, and responsibility. The paper validates the theoretically developed constructs and dimension in a well defined sample of social ventures, performing higher order confirmatory factor analysis (N~270)

Genetic analysis of synaptogyrin function in the synaptic vesicle cycle

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2012.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references.Neuronal communication relies on the continual replenishment of synaptic vesicles that are primed for neurotransmitter release in response to action potentials. A vast array of proteins is required to mediate synaptic vesicle biogenesis, trafficking, docking, exocytosis, and endocytosis. Synaptogyrin and synaptophysin are abundant and evolutionarily conserved synaptic vesicles proteins that were identified over twenty years ago, yet their exact function in the synaptic vesicle cycle remains unknown. To further elucidate the role of these proteins, we have generated and characterized a synaptogyrin null mutant in Drosophila, whose genome encodes a single synaptogyrin isoform and lacks a synaptophysin homolog. Here we demonstrate that Drosophila synaptogyrin is abundantly expressed in neurons, where it localizes to the presynaptic terminal of the larval neuromuscular junction (NMJ). Drosophila lacking synaptogyrin are viable and fertile and have no overt deficits in motor function or courtship behavior. Ultrastructural analysis of mutant larvae revealed an increase in average synaptic vesicle diameter as well as enhanced variability in the size of synaptic vesicles. In addition, the resolution of endocytic cisternae into synaptic vesicles in response to robust exocytosis is defective in synaptogyrin mutants. While basal synaptic transmission at the larval NMJ is unaffected, synaptogyrin mutants do display increased facilitation during high-frequency stimulation, indicating that synaptic vesicle exocytosis is abnormally regulated during strong stimulation conditions. These results suggest that, while not required for neurotransmission, Drosophila synaptogyrin nevertheless modulates synaptic vesicle exo-endocytosis, especially during elevated rates of synaptic vesicle fusion.by Robin J. Stevens.Ph.D

Uncoupling inequality: Reflections on the ethics of benchmarks for digital media

Our collaboration seeks to demonstrate shared interrogation by exploring the ethics of machine learning benchmarks from a socio-technical management perspective with insight from public health and ethnic studies. Benchmarks, such as ImageNet, are annotated open data sets for training algorithms. The COVID-19 pandemic reinforced the practical need for ethical information infrastructures to analyze digital and social media, especially related to medicine and race. Social media analysis that obscures Black teen mental health and ignores anti-Asian hate fails as information infrastructure. Despite inadequately handling non-dominant voices, machine learning benchmarks are the basis for analysis in operational systems. Turning to the management literature, we interrogate cross-cutting problems of benchmarks through the lens of coupling, or mutual interdependence between people, technologies, and environments. Uncoupling inequality from machine learning benchmarks may require conceptualizing the social dependencies that build structural barriers to inclusion

Social Media in the Sexual Lives of African American and Latino Youth: Challenges and Opportunities in the Digital Neighborhood

There has been significant interest in the role of social media in the lives of adolescents, particularly as it relates to sexual risk. Researchers have focused on understanding usage behaviors, quantifying effects of social media exposure and activity, and using social media to intervene. Much of this work has focused on college students and non-minority youth. In this paper, we examine the growing body of literature around social media use among US minority youth and its intersection with sexual risk behavior. We introduce the concept of the “digital neighborhood” and examine the intersection of social media and sexual health in two domains: 1) sexual content in social media and 2) evidence of social media effects on sexual behavior. Finally, we discuss the opportunities and challenges for researchers and practitioners engaging youth of color

Sex, Drugs, and Alcohol in the Digital Neighborhood: A multi-method analysis of online discourse amongst Black and Hispanic Youth

In the digital neighborhood, Black and Hispanic youth communicate their perspectives about a myriad of issues facing youth, including sex and substance use. This population of young people are also disproportionately burdened by negative outcomes associated with sex and substance use behaviors, even when their behavior is less risky. Given the increased likelihood of negative outcomes, we investigated how youth talk about these behaviors in their online social networks. This mixed methods study integrates a behavioral survey with a machine learning-supported, qualitative content analysis of one year of Facebook and Twitter posts from 50 participants, with feedback from a youth advisory board. Findings suggest that participants who drank were more likely to post about alcohol. Women posted more about STIs, HIV and pregnancy. Posts around sexual behavior often discussed trust in sexual partnerships and gendered views of sex. Alcohol and marijuana were used to relieve stress, to handle personal grief and community violence, and as a coping mechanism for general distress. Understanding how youth think about sexual risk and substance use can inform the design of more effective prevention efforts