Young Min Baek

Stages of pTDP-43 pathology in amyotrophic lateral sclerosis

To see whether the distribution patterns of phosphorylated 43kDa TAR DNA‐binding protein (pTDP‐43) intraneuronal inclusions in amyotrophic lateral sclerosis (ALS) permit recognition of neuropathological stages.

Online versus face-to-face deliberation: Who? Why? What? With what effects?

Although there has been much speculation regarding the strengths and weaknesses of face-to-face versus online deliberative settings, no studies have systematically compared the two. Drawing on a national sample of Americans who reported deliberating face-to-face and/or online, we examine these two deliberative settings with regard to the participants, the motivations, the process, and the effects. Our findings, although tentative, suggest that the two settings are distinct in several important ways. Relative to face-to-face deliberation, online deliberation over-represents young, male, and white users, attracts more ideological moderates, generates more negative emotions, and is less likely to result in consensus and political action. At the same time, online deliberators perceived online settings as more politically and racially diverse. Implications for understanding the democratic potential of different forms of deliberation are discussed.

A platform for discovery: The University of Pennsylvania Integrated Neurodegenerative Disease Biobank

Neurodegenerative diseases (NDs) are defined by the accumulation of abnormal protein deposits in the central nervous system (CNS), and only neuropathological examination enables a definitive diagnosis. Brain banks and their associated scientific programs have shaped the actual knowledge of NDs, identifying and characterizing the CNS deposits that define new diseases, formulating staging schemes, and establishing correlations between neuropathological changes and clinical features. However, brain banks have evolved to accommodate the banking of biofluids as well as DNA and RNA samples. Moreover, the value of biobanks is greatly enhanced if they link all the multidimensional clinical and laboratory information of each case, which is accomplished, optimally, using systematic and standardized operating procedures, and in the framework of multidisciplinary teams with the support of a flexible and user‐friendly database system that facilitates the sharing of information of all the teams in the network. We describe a biobanking system that is a platform for discovery research at the Center for Neurodegenerative Disease Research at the University of Pennsylvania.

To Buy or Not to Buy: Who are Political Consumers? What do they Think and How Do they Participate?

Political consumerism has recently generated academic interest among political participation researchers. While some scholars underscore political consumerism as an emerging civic and political engagement, others discredit its democratic potentials. Drawing on two national survey samples in 2002 that measured both boycotting and ‘buycotting’, this study examines political consumers demographic backgrounds, socio-political attitudes, issue orientations and their status of civic and political participation. Findings suggest that: (1) boycotters and buycotters should be distinguished because their demographic backgrounds are substantially different; (2) political consumers possess post-material values and are mainly interested in lifestyle-oriented social issues; and (3) political consumers are more active political participants. Theoretical implications of the findings and an agenda for future studies are also discussed.

Don't expect too much! learning from late-night comedy and knowledge item difficulty

The debate on late night comedy has been inconclusive, with some scholars arguing that this genre increases political knowledge, and others seeing late night comedy as harmful to effective citizenry. We add to the debate and to the research on media effects more generally, by proposing a model that measures political knowledge. The model utilizes item response theory (IRT) to account for individual characteristics, knowledge item difficulty, and response format that influences the likelihood of providing a correct response. Drawing on the 2004 National Annenberg Election Study, we employ this model to test knowledge gain from late night comedy. Using a meta-analysis across 35 political knowledge items, we show that late night comedy increases knowledge, but primarily on easy political items that have fewer correct response options, and mainly among the inattentive citizens. We discuss theoretical implications and provide practical suggestions for scholarship on media effects.

Building An Integrated Neurodegenerative Disease Database At An Academic Health Center

It is becoming increasingly important to study common and distinct etiologies, clinical and pathological features, and mechanisms related to neurodegenerative diseases such as Alzheimers disease, Parkinsons disease, amyotrophic lateral sclerosis, and frontotemporal lobar degeneration. These comparative studies rely on powerful database tools to quickly generate data sets that match diverse and complementary criteria set by them.

Comparison of xMAP and ELISA Assays for Detecting Cerebrospinal Fluid Biomarkers of Alzheimer's Disease

The best-studied biomarkers of Alzheimers disease (AD) are the pathologically-linked cerebrospinal fluid (CSF) proteins amyloid-β 42 (Aβ(1-42)), total tau (t-tau), and tau phosphorylated on amino acid 181 (p-tau(181)). Many laboratories measure these proteins using enzyme-linked immunosorbent assay (ELISA). Multiplex xMAP Luminex is a semi-automated assay platform with reduced intra-sample variance, which could facilitate its use in CLIA-approved clinical laboratories. CSF concentrations of these three biomarkers reported using xMAP technology differ from those measured by the most commonly used ELISA, confounding attempts to compare results. To develop a model for converting between xMAP and ELISA levels of the three biomarkers, we analyzed CSF samples from 140 subjects (59 AD, 30 controls, 34 with mild cognitive impairment, and 17 with Parkinsons disease, including 1 with dementia). Log-transformation of ELISA and xMAP levels made the variance constant in all three biomarkers and improved the linear regression: t-tau concentrations were highly correlated (r = 0.94); p-tau(181) concentrations by ELISA can be better predicted using both the t-tau and p-tau(181) xMAP values (r = 0.96) as compared to p-tau(181) concentrations alone (r = 0.82); correlation of Aβ(1-42) concentrations was relatively weaker but still high (r = 0.77). Among all six protein/assay combinations, xMAP Aβ(1-42) had the best accuracy for diagnostic classification (88%) between AD and control subjects. In conclusion, our study demonstrates that multiplex xMAP is an appropriate assay platform providing results that can be correlated with research-based ELISA values, facilitating the incorporation of this diagnostic biomarker into routine clinical practice.

Comparative survey of the topographical distribution of signature molecular lesions in major neurodegenerative diseases

An understanding of the anatomic distributions of major neurodegenerative disease lesions is important to appreciate the differential clinical profiles of these disorders and to serve as neuropathological standards for emerging molecular neuroimaging methods. To address these issues, here we present a comparative survey of the topographical distribution of the defining molecular neuropathological lesions among 10 neurodegenerative diseases from a large and uniformly assessed brain collection. Ratings of pathological severity in 16 brain regions from 671 cases with diverse neurodegenerative diseases are summarized and analyzed. These include: 1) amyloid‐β and tau lesions in Alzheimers disease; 2) tau lesions in three other tauopathies including Picks disease, progressive supranuclear palsy and corticobasal degeneration; 3) α‐synuclein inclusion ratings in four synucleinopathies including Parkinsons disease, Parkinsons disease with dementia, dementia with Lewy bodies, and multiple system atrophy; and 4) TDP‐43 lesions in two TDP‐43 proteinopathies, including frontotemporal lobar degeneration associated with TDP‐43 and amyotrophic lateral sclerosis. The data presented graphically and topographically confirm and extend previous pathological anatomic descriptions and statistical comparisons highlight the lesion distributions that either overlap or distinguish the diseases in each molecular disease category. J. Comp. Neurol. 521:4339–4355, 2013.

An integrative model of ambivalence

Abstract Ambivalence is a widely experienced psychological state, but inter-disciplinary studies, to a certain extent, define and conceptualize ambivalence independently. In spite of its lack of clarity, ambivalence has become an increasingly popular concept, utilized in hypotheses concerning a variety of social phenomena. This study provides an overview of extant studies on ambivalence, and summarizes the similarities and differences in how practitioners of social psychology, political science, and sociology have adopted the concept. A survey of literature from the three fields suggests four distinctive definitions of ambivalence or antecedents that have caused ambivalence: (1) co-activation of both positivity and negativity; (2) co-emergence of conflicting attitudes; (3) co-constraint of conflicting values; and (4) co-existence of conflicting reference groups. Some potential problems, such as inconsistent findings and lack of relevant measures or indices are indicated, and alternative methods are suggested. The paper concludes by suggesting a more sophisticated and precise integrative model of ambivalence.

WHAT IS REALLY GOING ON

Does deliberative setting, online versus face-to-face, influence citizens experiences? Are certain factors differently influential in one setting than in the other? We draw on a nationally representative survey and identify citizens who participated in both online and face-to-face settings (nu2009=u200982). We use structural equation modeling to first assess the effects that deliberation format has on the interrelationship between such crucial factors as motivations to deliberate, perceived diversity, elicited emotions, enhanced understanding, and goal evaluation. We later employ network analysis to ask which factor or which cluster of factors is more central to an overall experience in which format. Relying on citizens who participated in both settings and using within-subject analyses, we assure that the previously unnoted findings are attributable to the format per se rather than to individual characteristics. We discuss the theoretical, practical and methodological implications.