David A. Askay

Alterations in mGluR5 Expression and Signaling in Lewy Body Disease and in Transgenic Models of Alpha-Synucleinopathy – Implications for Excitotoxicity

Dementia with Lewy bodies (DLB) and Parkinsons Disease (PD) are neurodegenerative disorders of the aging population characterized by the abnormal accumulation of alpha-synuclein (alpha-syn). Previous studies have suggested that excitotoxicity may contribute to neurodegeneration in these disorders, however the underlying mechanisms and their relationship to alpha-syn remain unclear. For this study we proposed that accumulation of alpha-syn might result in alterations in metabotropic glutamate receptors (mGluR), particularly mGluR5 which has been linked to deficits in murine models of PD. In this context, levels of mGluR5 were analyzed in the brains of PD and DLB human cases and alpha-syn transgenic (tg) mice and compared to age-matched, unimpaired controls, we report a 40% increase in the levels of mGluR5 and beta-arrestin immunoreactivity in the frontal cortex, hippocampus and putamen in DLB cases and in the putamen in PD cases. In the hippocampus, mGluR5 was more abundant in the CA3 region and co-localized with alpha-syn aggregates. Similarly, in the hippocampus and basal ganglia of alpha-syn tg mice, levels of mGluR5 were increased and mGluR5 and alpha-syn were co-localized and co-immunoprecipated, suggesting that alpha-syn interferes with mGluR5 trafficking. The increased levels of mGluR5 were accompanied by a concomitant increase in the activation of downstream signaling components including ERK, Elk-1 and CREB. Consistent with the increased accumulation of alpha-syn and alterations in mGluR5 in cognitive- and motor-associated brain regions, these mice displayed impaired performance in the water maze and pole test, these behavioral alterations were reversed with the mGluR5 antagonist, MPEP. Taken together the results from study suggest that mGluR5 may directly interact with alpha-syn resulting in its over activation and that this over activation may contribute to excitotoxic cell death in select neuronal regions. These results highlight the therapeutic importance of mGluR5 antagonists in alpha-synucleinopathies.

Silence in the crowd: The spiral of silence contributing to the positive bias of opinions in an online review system

A positive bias of opinions has frequently been identified across online review websites, suggesting that the public is making decisions based on a limited range of opinions. While scholars often attribute this bias to social loafing or self-selection, this study investigates the positive bias from the perspective of opinion expression. Drawing from the spiral of silence theory, a qualitative analysis of discussion forums reveals that fear of isolation reduces the willingness of members to voice neutral and negative reviews. Additionally, communicative affordances of the interface were found to further suppress neutral and negative opinions. These results extend the spiral of silence theory into the context of non-anonymous multichannel communication platforms and indicate the need to consider the role of communicative affordances in online opinion expression.

The Multidimensional Role of Trust in Enabling Creativity within Virtual Communities of Practice: A Theoretical Model Integrating Swift, Knowledge-Based, Institution-Based, and Organizational Trust

Virtual communities of practice are gaining attention among scholars and practitioners as managers and high-level executives look for ways to adapt to an ever-increasing rate of environmental change. These communities have been recognized as a tool for generating new ideas by accessing geographically distributed expertise. As most expert knowledge is tacit and tacit knowledge exchange is what leads to creativity, an understanding of antecedents to tacit knowledge exchange is needed. This manuscript responds by examining the role of trust, a well-known antecedent of creativity, within the context of virtual communities of practice. An interdisciplinary approach led to the development of a multi-level, multi-dimensional model of trust. The authors propose that different dimensions of trust serve as both an antecedent and outcome of creativity in virtual communities of practice, by taking on various forms and roles in the creative process based on tenure of its members.

Concealing Communities Within the Crowd Hiding Organizational Identities and Brokering Member Identifications of the Yelp Elite Squad

This study investigates organizational identity and member identification in a hidden organization operating within a crowd-based collective. Specifically, it draws from Scott’s hidden organization framework to examine the role of the Yelp Elite Squad, an invitation-only organization that receives access to free monthly parties and other rewards organized by a local employee of Yelp. Analyses of qualitative interviews and participant observation indicate that through limited information, restricted channels of communication, and framing participation as “community,” Yelp is able to conceal the Elite Squad organizational identity from both the public as well as members of the Elite Squad. Further analysis reveals tensions emerging from expressing and suppressing organizational identification among members of the Elite Squad. Finally, Yelp is shown to broker (in)visibilities of the Elite Squad with local businesses to create value for the organization.

Of values and functionality: the sequestering nonpositive reviews in an online feedback system

The positive bias commonly found in online feedback systems suggests the presence of a marginalized group of users that sequester their non-positive reviews, excluding these users from participation in social discourse. To understand the barriers to participation, this paper analyzes unsolicited online forum discussions of a virtual community to identify features of an online feedback system that may act as barriers to contribution. By examining conflicts between user perceptions of values and functionality of the system, this study reveals that character limitations to reviews and restricted labeling conventions discourage users from contributing non-positive feedback.

A Conceptual Framework for Investigating Organizational Control and Resistance in Crowd-Based Platforms

This paper presents a research agenda for crowd behavior research by drawing from the organizational control literature. It addresses the need for research into the organizational and social structures that guide user behavior and contributions in crowd-based platforms. Crowd behavior is situated within a conceptual framework of organizational control. This framework helps scholars more fully articulate the full range of control mechanisms operating in crowd-based platforms, contextualizes these mechanisms into the context of crowd-based platforms, challenges existing rational assumptions about incentive systems, and clarifies theoretical constructs of organizational control to foster stronger integration between information systems research and organizational and management science.

From "Effects" to "Entanglements": A Fishbowl Discussion on Sociomateriality

Multiple research areas within the field of information studies grapple with the notion of technology and its role in social processes and outcomes. Recent theorizations on sociomateriality reflect ...

Managing Entitativity through Social Media

Abstract Purpose This chapter examines the affordances of social media to understand how groups are experienced through social media. Specifically, the chapter presents a theoretical model to understand how affordances of social media promote or suppress entitativity. Methodology Participants (N=265) were recruited through snowball sampling to answer questions about their recent Facebook status updates. Confirmatory factor analysis (CFA) was used to examine the goodness of fit for our model. Findings We validate a model of entitativity as it occurs through the affordances offered by social media. Participant’s knowledge that status update responders were an interacting group outside of Facebook affected their perceptions of interactivity in the responses. Interactivity and history of interactions were the strongest predictors of status update entitativity. Further, status update entitativity had positive relationships with overall Facebook entitativity as well as group identity. Practical implications To encourage group identity through social media, managers need to increase employees’ perceptions of entitativity, primarily by enabling employees to see the interactions of others and to contribute content in social media platforms. Originality/value This is the only study we know of that empirically examines how groups are experienced through social media. Additionally, we draw from an affordance perspective, which helps to generalize our findings beyond the site of our study.