bluuebunny/crossref_metadata_2025 huggingface dataset:
First Comes Love, Then Comes Google: An Investigation of Uncertainty Reduction Strategies and Self-Disclosure in Online Dating
Authors: Gibbs Jennifer L. , Ellison Nicole B. , Lai Chih-Hui
Published: December 2010

This study investigates relationships between privacy concerns, uncertainty reduction behaviors, and self-disclosure among online dating participants, drawing on uncertainty reduction theory and the warranting principle. The authors propose a conceptual model integrating privacy concerns, self-efficacy, and Internet experience with uncertainty reduction strategies and amount of self-disclosure and then test this model on a nationwide sample of online dating participants ( N = 562). The study findings confirm that the frequency of use of uncertainty reduction strategies is predicted by three sets of online dating concerns—personal security, misrepresentation, and recognition—as well as self-efficacy in online dating. Furthermore, the frequency of uncertainty reduction strategies mediates the relationship between these variables and amount of self-disclosure with potential online dating partners. The authors explore the theoretical implications of these findings for our understanding of uncertainty reduction, warranting, and self-disclosure processes in online contexts.
Genre-Specific Cultivation Effects
Authors: Lee Chul-joo , Niederdeppe Jeff
Published: December 2010

Cultivation theory and research have been criticized for their failures to consider variation in effects by genre, employ appropriate third-variable controls, and determine causal direction. Recent studies, controlling for a variety of demographic characteristics and media use variables, have found that exposure to local television (TV) newscasts is associated with a variety of problematic “real-world” beliefs. However, many of these studies have not adequately assessed causal direction. Redressing this limitation, we analyzed data from a two-wave national representative survey which permitted tests of lagged association between overall TV viewing, local TV news viewing, and fatalistic beliefs about cancer prevention. We first replicated the original cultivation effect and found a positive association between overall TV viewing at Time 1 and increased fatalistic beliefs about cancer prevention at Time 2. Analyses also provided evidence that local TV news viewing at Time 1 predicts increased fatalistic beliefs about cancer prevention at Time 2. There was little evidence for reverse causation in predicting changes in overall TV viewing or local TV news viewing. The article concludes with a discussion of theoretical and practical implications of these findings.
An Item Response Theory Analysis of the Mathematics Teaching Efficacy Beliefs Instrument
Authors: Kieftenbeld Vincent , Natesan Prathiba , Eddy Colleen
Published: December 2010

The mathematics teaching efficacy beliefs of preservice elementary teachers have been the subject of several studies. A widely used measure in these studies is the Mathematics Teaching Efficacy Beliefs Instrument (MTEBI). The present study provides a detailed analysis of the psychometric properties of the MTEBI using Bayesian item response theory. We discuss local dependence between item pairs, psychometric quality of the items, validity of the scoring procedure, and measurement accuracy for teachers with different efficacy levels. Our findings suggest that in its present form, the test reliability of the MTEBI may not be as high as assumed to date. The scale, wording, and placement of the items need revision. Moreover, additional items need to be constructed to measure below average levels of efficacy more accurately. Ordering the items according to difficulty, we describe the structure of mathematics teaching efficacy beliefs and draw some implications for mathematics teacher educators.
Peer violence perpetration among urban adolescents: Dispelling the myth of the violent immigrant
Authors: Almeida Joanna , Johnson Renee M. , McNamara Mariah , Gupta Jhumka
Published: December 2010

Researchers have found an inverse relationship between immigrant status and violence perpetration. Most studies have examined Mexican immigrants, and few have assessed immigration factors other than nativity. Additionally, the majority have focused on the most serious forms of violence despite the fact that moderate violence is more common.

Using data from the 2008 Boston Youth Survey, we generated prevalence estimates of peer violence perpetration across immigration related factors, examined whether risk factors for peer violence differed by these variables, and explored the contribution of risk factors to peer violence perpetration. Recent immigrants had a significantly lower prevalence of peer violence compared to each other generations/time in U.S. group. Known risk factors for violence perpetration varied by generation/time in U.S.: compared to other groups, recent immigrants were less likely to have used substances, and were more likely earn A’s and B’s in school. Recent immigrants had a significantly lower risk of violence perpetration relative to U.S.-born (RR = 0.35, 95% CI: 0.19, 0.62). Adjusting for known risk factors did not attenuate differences in risk.

While immigrant youth had a lower risk of peer violence, the protective effect was diminished among immigrants who had resided in the U.S. for >4 years. This pattern demonstrates that negative assimilation occurs within the first generation, not just across generations. Results suggest that perpetration of violence worsens with increased time in the U.S. Research is needed to identify factors that contribute to the acquisition of behaviors such as violence among recently arrived immigrant youth.
Distinctive Characteristics of Sexual Orientation Bias Crimes
Authors: Stacey Michele
Published: December 2010

Despite increased attention in the area of hate crime research in the past 20 years, sexual orientation bias crimes have rarely been singled out for study. When these types of crimes are looked at, the studies are typically descriptive in nature. This article seeks to increase our knowledge of sexual orientation bias by answering the question: What are the differences between sexual orientation motivated bias crimes and racial bias crimes? This question is examined using data from the National Incident Based Reporting System (NIBRS) and multiple regression techniques. This analysis draws on the strengths of NIBRS to look at the incident characteristics of hate crimes and distinguishing characteristics of sexual orientation crimes. Specifically this analysis looks at the types and seriousness of offenses motivated by sexual orientation bias as opposed to race bias as well as victim and offender characteristics. The findings suggest that there are differences between these two types of bias crimes, suggesting a need for further separation of the bias types in policy and research.
Preliminary Validation of the Child Abuse Potential Inventory in Turkey
Authors: Kutsal Ebru , Pasli Figen , Isikli Sedat , Sahin Figen , Yilmaz Gokce , Beyazova Ufuk
Published: December 2010

This study aims to provide preliminary findings on the validity of Child Abuse Potential Inventory (CAP Inventory) on Turkish sample of 23 abuser and 47 nonabuser parents. To investigate validity in two groups, Minnesota Multiphasic Personality Inventory (MMPI) Psychopathic Deviate (MMPI-PD) scale is also used along with CAP. The results show that, with the 200.5 cutoff point, which is the average score of the whole Turkish sample, Abuse Scale correctly classified 83% of the participants in the abuse group and 78.8% of the participants in the control group, which gives 21.2% false-positive result. MMPI-PD to all group and Pearson correlation coefficient analysis is found to be significant for both groups. These results show us high reliability and validity of the abuse scale for Turkey.
Psychological Abuse and Posttraumatic Stress Symptoms in College Students
Authors: Avant Elizabeth M. , Swopes Rachel M. , Davis Joanne L. , Elhai Jon D.
Published: December 2010

Research suggests that among college students, physical and sexual abuse in intimate relationships are associated with posttraumatic stress. Psychological abuse occurs in intimate relationships among college students, and though there is evidence that such abuse has a negative emotional impact, posttraumatic stress has not been extensively researched as an outcome in this population. The purpose of this study is to determine the associations of past-year psychological abuse with posttraumatic stress symptoms while controlling for other types of past-year relationship abuse and lifetime trauma history. The sample consists of 191 college men and women (81.7% women and 89.5% White). Linear regression analyses demonstrate that trauma history, but not past year relationship violence, is a significant predictor of PTSD symptom severity for women, and neither set of variables significantly predicts PTSD symptom severity for men. Implications for future research are discussed.
Reactions to Participating in Dating Violence Research: Are Our Questions Distressing Participants?
Authors: Shorey Ryan C. , Cornelius Tara L. , Bell Kathryn M.
Published: December 2010

In recent years, there has been increased research focus on dating violence, producing important information for reducing these violent relationships. Yet Institutional Review Boards (IRBs) are often hesitant to approve research on dating violence, citing emotional distress of participants as a possible risk of participation. However, no known research has examined the reactions of research participants to questions about dating violence. The current study examined the reactions among college students to completing a self-report measure on dating violence. Results showed that participants reported numerous positive experiences as a result of their research participation, with only mildly increased negative emotional reactions evident for some. Findings are discussed in relation to IRB proposals and appropriate informed consent for research participants.
Alcohol Consumption and Health Status in Very Old Veterans
Authors: Denneson Lauren M. , Lasarev Michael R. , Dickinson Kathryn C. , Dobscha Steven K.
Published: December 2010

Previous research has linked drinking with health, but has yet to address alcohol consumption and the relationship between drinking and health among very old veterans. To help fill this gap, the authors present a cross-sectional self-report study on 1105 veterans age 90 and older who completed the national Veteran’s Affairs (VA) Survey of the Health Experiences of Patients (SHEP) for fiscal year (FY) 2005. Alcohol consumption was measured using Alcohol Use Disorders Identification Test scores (AUDIT-C).1 Health status was measured using the Veterans Rand Health Survey: VR-12.2 Among men (n = 1063), 60% were abstainers. No significant differences in mental health component (MCS; F3,1040 = 1.80, P = .15) or physical health component (PCS; F3,1040 = 1.48, P = .22) scores were detected across consumption categories. Among women (n = 42), 47% were abstainers. These results suggest many very old veterans abstain from alcohol and, among men, the associations between health status and drinking observed in younger groups may not be present in very old age.
Local Government Without Governance: A New Institutional Perspective of Local Governance Policy Paralysis in Malawi
Authors: Tambulasi Richard I.C.
Published: December 2010

Democratic local governance in Malawi dates back to the year 2000 when Malawi had its first democratic local government elections. The councillors’ mandate ended in March 2005 and a new set of local government elections were supposed to be held in the same month. However, up to the writing of this article (April 2010) the Government has not yet conducted the local government elections. With the presidential and parliamentary elections already held in May 2009, there are no plans to conduct local elections any sooner. The argument of this article is that the absence of councillors is paralyzing the local governance policy in the country. This is because currently, it is only administrative activities that are taking place but governance functions have been stalled, thereby paralyzing the policies that provide for these functions. Taking a new institutional perspective, this article seeks to understand the nature, dynamics, explanations and impacts of the paralysis. Through an institutional analysis, the article explains the intricacies that shape the local governance policy paralysis in Malawi and the underlying motives of the political actors in the paralysis.
The case of the disappearing dilemma: Herbert Blumer on sociological method
Authors: Hammersley Martyn
Published: December 2010

Herbert Blumer was a key figure in what came to be identified as the Chicago School of Sociology. He invented the term ‘symbolic interactionism’ as a label for a theoretical approach that derived primarily from the work of John Dewey, George Herbert Mead and Charles Cooley. But his most influential work was methodological in character, and he is generally viewed today as a prominent critic of positivism, and of the growing dominance of quantitative method within US sociology. While this picture is broadly accurate, it neglects an important strand in his methodological thinking. He was committed to the goal of a science of social life, while at the same time he was uncertain whether such a science is possible. In his Appraisal of Thomas and Znaniecki’s The Polish Peasant, he identified a serious dilemma facing this project: the problem of how a scientific approach can be made compatible with the distinctive nature of human social life. In the first chapter of his most influential book, Symbolic Interactionism, he advocates a naturalistic approach to case study, and seems to treat this as avoiding the dilemma. However, there is evidence to suggest that, even towards the end of his life, he regarded the problem as still unresolved. In this article, I examine both sides of Blumer’s dilemma, and whether his attitude towards it changed. However, my interest here is not only historiographical. I evaluate Blumer’s arguments and show that his intellectual struggle with this issue remains relevant today, despite the shifts that have taken place in social science methodology and the philosophy of science since his death.
Alternative Avenues in the Assessment of Driving Capacities in Older Drivers and Implications for Training
Authors: Gamache Pierre-Luc , Hudon Carol , Teasdale Normand , Simoneau Martin
Published: December 2010

The aging of the population, combined with the overrepresentation of older drivers in car crashes, has engendered a whole body of research destined at finding simple and efficient assessment methods of driving capacities. Such a search is destined to fail, given that car crashes and unsafe driving behaviors can result from myriad interacting factors. This review highlights the main problems of the current assessment methods and training programs and presents theoretical and empirical arguments justifying the need of reorienting the research focus. In our discussion, we elaborate the fundamental principle of specificity in learning and practice. We also identify overlooked variables that are deterministic when assessing and training a complex ability like driving. We especially focus on the role of the sensorimotor transformation process. Finally, we propose alternative methods of assessment and training that, in line with recent trends in education, use virtual reality and simulation technologies.
Distress Tolerance
Authors: Zvolensky Michael J. , Vujanovic Anka A. , Bernstein Amit , Leyro Teresa
Published: December 2010

In this article we present the theoretical and empirical bases of distress tolerance research. Although distress tolerance offers a promising lens through which to better understand various psychological symptoms and disorders, further theoretical development and empirical inquiry is needed to promote our understanding of the construct. Overall, a number of questions regarding its theoretical conceptualization and measurement, associations with related constructs and psychopathology, and role(s) in therapeutic change and intervention remain unanswered. Directions for future research are discussed to stimulate further empirical study on this theoretically and clinically promising topic.
Fact and Fiction in Cognitive Ability Testing for Admissions and Hiring Decisions
Authors: Kuncel Nathan R. , Hezlett Sarah A.
Published: December 2010

Standardized measures of intelligence, ability, or achievement are all measures of acquired knowledge and skill and have consistent relationships with multiple facets of success in life, including academic and job performance. Five persistent beliefs about ability tests have developed, including: (a) that there is no relationship with important outcomes like creativity or leadership, (b) that there is predictive bias, (c) that there is a lack of predictive independence from socioeconomic status, (d) that there are thresholds beyond which scores cease to matter, and (e) that other characteristics, like personality, matter as well. We present the evidence and conclude that of these five beliefs, only the importance of personality is a fact; the other four are fiction.
A New Look at Selective-Exposure Effects
Authors: Fischer Peter , Greitemeyer Tobias
Published: December 2010

When individuals make decisions, they tend to prefer information that is consistent with their choices over information that is inconsistent with their choices. This phenomenon is known as selective exposure to confirmatory information, and it has been shown to detrimentally affect the quality of decision outcomes. In this article, we review the most important recent findings on the determinants of this phenomenon, highlight its potential real-life consequences for decision makers and their judgments, and propose a theoretical model that is able to integrate a variety of inconsistent findings in selective exposure research.
Beyond the Threshold Hypothesis
Authors: Robertson Kimberley Ferriman , Smeets Stijn , Lubinski David , Benbow Camilla P.
Published: December 2010

The assertion that ability differences no longer matter beyond a certain threshold is inaccurate. Among young adolescents in the top 1% of quantitative reasoning ability, individual differences in general cognitive ability level and in specific cognitive ability pattern (that is, the relationships among an individual’s math, verbal, and spatial abilities) lead to differences in educational, occupational, and creative outcomes decades later. Whereas ability level predicts the level of achievement, ability pattern predicts the realm of achievement. Adding information on vocational interests refines prediction of educational and career choices. Finally, lifestyle preferences relevant to career choice, performance, and persistence often change between ages 25 and 35. This change results in sex differences in preferences, which likely have relevance for understanding the underrepresentation of women in careers that demand more than full-time (40 hours per week) commitment.
Conflict in Small Groups: The Meaning and Consequences of Process Conflict
Authors: Behfar Kristin J. , Mannix Elizabeth A. , Peterson Randall S. , Trochim William M.
Published: December 2010

Through three studies of interacting small groups, we aimed to better understand the meaning and consequences of process conflict. Study 1 was an exploratory analysis of qualitative data that helped us to identify the unique dimensions of process conflict to more clearly distinguish it from task and relationship conflict. Study 2 used a broader sampling of participants to (a) demonstrate why process conflict has been difficult to discriminate from task conflict in many conflict scales, and (b) develop a two-factor Process Conflict Scale that effectively distinguishes process from task conflict. Study 3 used this new scale to examine the relationship between process conflict and group viability (group performance, satisfaction, and effective group process). The results showed that process conflict negatively affects group performance, member satisfaction, and group coordination.
Prevalence of Life-Threatening Conditions in Children
Authors: Randall Virginia , Cervenka Jason , Arday David , Hooper Tomoko , Hanson Janice
Published: December 2010

Objective: We estimated the prevalence of children with life-threatening conditions (LTC) cared for in the military health system (MHS) in response to a Congressional inquiry and to inform program planning. Methods: We developed a case definition of LTC, using the concept ‘‘death trajectory’’1,2 to define our cases. We conducted an unduplicated count of children with LTC in the MHS database during FY 2001/FY 2002 using selected ICD-9 codes based on our case definition. We then surveyed the literature for reported prevalence of LTC among children with similar case definitions. The concept of ‘‘death trajectory’’ describes non-categorical life-threatening conditions of four types: progressive decline to death (e.g., spinal muscular atrophy); intermittent periods of intensive care to maintain quality-of-life (e.g., cystic fibrosis); curative treatment is possible but may fail (e.g., childhood cancers); and severe but non-progressive disability with extreme health vulnerability (e.g., spastic quadriplegia with tracheotomy). Results: There were 3,976 children identified with LTC in a population of 2.6 million children, for a prevalence of 0.15%. Conclusion: A prevalence of 0.15% for children with LTC in the MHS population agrees closely with that derived for similar case definitions by other authors among populations of children in other single-payer health care systems (i.e., United Kingdom). The method used here may apply to similar health care systems with ICD 9 codes in a searchable database.
Development and Evaluation of a Program to Strengthen First Year Residents’ Proficiency in Leading End-of-Life Discussions
Authors: Williams Donna M. , Fisicaro Tamara , Veloski J. Jon , Berg Dale
Published: December 2010

Purpose: Multiple interventions have been developed to teach and improve internal medicine residents’ end-of-life communication skills, but have not been easily adaptable to other institutions. The purpose of this study was to develop and evaluate a program to enhance physicians’ end-of-life communication with families of dying patients using a format that could be incorporated into an existing curriculum for first-year internal medicine residents. Methods: An end-of-life educational program was developed and evaluated in the context of educating first-year residents at an urban academic medical center during the 2008-2009 academic year. The program consisted of three sessions including an interactive workshop flanked by pre- and post-workshop evaluations in simulated encounter and clinical vignette formats. Simulated encounters were recorded on video and residents’ performances were rated by two independent observers using a 23 point checklist. Results: Complete data were available for 24 (73%) of 33 residents who participated in the program. The residents’ checklist scores increased significantly from a mean of 48.1 at baseline to 73.9 at follow-up. The increase in the scores on the clinical vignettes was also statistically significant, but of lesser magnitude. Conclusions: A short, focused intervention can have significant impact on residents’ communication skills in the setting of an end-of-life objective structured clinical examination (OSCE).
JPBI 10 Years Later: Trends in Research Studies
Authors: O'Dell Sean M. , Vilardo Brigid A. , Kern Lee , Kokina Anastasia , Ash Allison N. , Seymour Kimberly J. , Castrantas Lauren M. , Kollar Rachel B. , Wagner Andrea M. , Bartholomew Audrey , Thomas Lisa B.
Published: December 2010

In 2008, the Journal of Positive Behavior Interventions ( JPBI) celebrated 10 years in publication. As the flagship journal of positive behavior support (PBS), it is important to periodically examine the research published in JPBI to determine whether it reflects the basic principles of PBS, to explore the ways in which PBS is being practiced, and to consider future directions for PBS. We analyzed various dimensions of intervention research studies published in JPBI during the first 10 years. The data indicate that research has increasingly becoming aligned with PBS principles in many areas, yet other areas merit additional focus in the future.
What Does Seeing an Image Mean?
Authors: Mondzain Marie-José
Published: December 2010

To ask what seeing an image means is nothing more than trying to understand how, in viewing images, we become spectators with a new role of speaking and desiring subjects. The Christian history of images was significant for western relationships to images as the iconoclastic crisis created fundamental distinctions between vision and gaze, visible and invisible, power and authority, belief and suspicion. If we look further at paleontological images found in caves, it seems that the iconic gesture represents the speaking and desiring subject. The Christian doctrine was an ‘economical’ sequence of negotiation between anthropological truth and political purposes.
Oral Definitions of Newly Learned Words
Authors: Steele Sara C.
Published: December 2010

This study examined and compared patterns of errors in the oral definitions of newly learned words. Fifteen 9- to 11-year-old children with language learning disability (LLD) and 15 typically developing age-matched peers inferred the meanings of 20 nonsense words from four novel reading passages. After reading, children provided oral definitions for target words. Oral definition errors were categorized and proportions were computed. Results indicated that the LLD and typical groups showed similar error proportions in indeterminate ( p = .055), false ( p = .506), and semantic ( p = .370) categories. Different error proportions were found for phonological ( p = .048), sentence ( p = .031), substitution ( p = .001), and syntactic ( p = .023) categories. Similar patterns of errors were found for frontier and unknown words for the LLD group. These patterns provided evidence that children with LLD have difficulty gaining partial word knowledge during reading tasks.
Shirking the Initiative? The Effects of Statewide Ballot Measures on Congressional Roll Call Behavior
Authors: Huder Joshua , Ragusa Jordan Michael , Smith Daniel A.
Published: December 2010

Do ballot measures affect congressional voting behavior? Examining the issues of gay marriage, campaign finance, and minimum wage, we test if the results of statewide ballot initiatives inform congressional roll call votes on legislation occupying the same issue space. Theoretically, we expect signals from ballot measures—which provide precise information about the preferences of a member’s voting constituency—reduce policy “shirking” by members. Our findings across the three issues indicate that ballot initiative outcomes alter the floor votes of members of the House, reducing legislative shirking, but we find that the educative effect of ballot measures is attenuated in the Senate due to institutional factors. We attribute the positive effect in House to the precise signal ballot measures provide members about the preferences of the median voter in their district.
The PP2A inhibitor SET regulates granzyme B expression in human natural killer cells
Authors: Trotta Rossana , Ciarlariello David , Dal Col Jessica , Mao Hsiaoyin , Chen Li , Briercheck Edward , Yu Jianhua , Zhang Jianying , Perrotti Danilo , Caligiuri Michael A.
Published: December 2010

The ability of natural killer (NK) cells to kill malignant or infected cells depends on the integration of signals from different families of cell surface receptors, including cytokine receptors. How such signals then regulate NK-cell cytotoxicity is incompletely understood. Here we analyzed an endogenous inhibitor of protein phosphatase 2A (PP2A) activity called SET, and its role in regulating human NK-cell cytotoxicity and its mechanism of action in human NK cells. RNAi-mediated suppression of SET down-modulates NK-cell cytotoxicity, whereas ectopic overexpression of SET enhances cytotoxicity. SET knockdown inhibits both mRNA and protein granzyme B expression, as well as perforin expression, whereas SET overexpression enhances granzyme B expression. Treatment of NK cells with the PP2A activator 1,9-dideoxy-forskolin also inhibits both granzyme B expression and cytotoxicity. In addition, pretreatment with the PP2A inhibitor okadaic acid rescues declining granzyme B mRNA levels in SET knockdown cells. Down-modulation of SET expression or activation of PP2A also decreases human NK-cell antibody-dependent cellular cytotoxicity. Finally, the induction of granzyme B gene expression by interleukin-2 and interleukin-15 is inhibited by SET knockdown. These data provide evidence that granzyme B gene expression and therefore human NK-cell cytotoxicity can be regulated by the PP2A-SET interplay.
Results of allogeneic hematopoietic stem cell transplantation for chronic myelogenous leukemia patients who failed tyrosine kinase inhibitors after developing BCR-ABL1 kinase domain mutations
Authors: Jabbour Elias , Cortes Jorge , Santos Fabio P. S. , Jones Dan , O'Brien Susan , Rondon Gabriela , Popat Uday , Giralt Sergio , Kebriaei Partow , Jones Roy B. , Kantarjian Hagop , Champlin Richard , de Lima Marcos
Published: December 2010

Hematopoietic stem cell transplantation (HSCT) is effective therapy for patients with chronic myelogenous leukemia (CML) but is now mostly indicated for patients who develop resistance to tyrosine kinase inhibitors (TKIs), which can be associated with point mutations in BCR-ABL1. We reviewed the outcomes of imatinib-resistant CML patients (chronic phase, n = 34; accelerated phase [AP], n = 9; and blast phase [BP], n = 4) who underwent HSCT and had BCR-ABL1 sequencing. Mutations were found in 19 patients (40%); 15 of 19 had advanced CML (AP + BP + second chronic phase). Patients with mutations were more likely to transform to AP/BP at time of imatinib failure (69% vs 35%, P = .03). Forty-two patients (89%) responded to HSCT: 32 (68%) had at least a major molecular response. The 2-year event-free survival was 36% and 58% (P = .05) for the mutant and nonmutant groups, respectively; and the 2-year overall survival was 44% and 76% (P = .02), respectively. HSCT is an important salvage option for TKI-resistant patients with or without BCR-ABL1 mutations. Patients with mutations were more likely to develop advanced disease and had worse outcomes after HSCT. HSCT should be considered early for patients deemed to have a low probability of responding to second-generation TKI.
Perfect-Information Games with Lower-Semicontinuous Payoffs
Authors: Flesch János , Kuipers Jeroen , Mashiah-Yaakovi Ayala , Schoenmakers Gijs , Solan Eilon , Vrieze Koos
Published: December 2010

We prove that every multiplayer perfect-information game with bounded and lower-semicontinuous payoffs admits a subgame-perfect ε-equilibrium in pure strategies. This result complements Example 3 in Solan and Vieille [Solan, E., N. Vieille. 2003. Deterministic multi-player Dynkin games. J. Math. Econom. 39 911–929], which shows that a subgame-perfect ε-equilibrium in pure strategies need not exist when the payoffs are not lower-semicontinuous. In addition, if the range of payoffs is finite, we characterize in the form of a Folk Theorem the set of all plays and payoffs that are induced by subgame-perfect 0-equilibria in pure strategies.
Wiener Disorder Problem with Observations at Fixed Discrete Time Epochs
Authors: Dayanik Savas
Published: December 2010

Suppose that a Wiener process gains a known drift rate at some unobservable disorder time with some zero-modified exponential distribution. The process is observed only at known fixed discrete time epochs, which may not always be spaced in equal distances. The problem is to detect the disorder time as quickly as possible by means of an alarm that depends only on the observations of Wiener process at those discrete time epochs. We show that Bayes optimal alarm times, which minimize expected total cost of frequent false alarms and detection delay time, always exist. Optimal alarms may in general sound between observation times and when the space-time process of the odds that disorder happened in the past hits a set with a nontrivial boundary. The optimal stopping boundary is piecewise-continuous and explodes as time approaches from left to each observation time. On each observation interval, if the boundary is not strictly increasing everywhere, then it first decreases and then increases. It is strictly monotone wherever it does not vanish. Its decreasing portion always coincides with some explicit function. We develop numerical algorithms to calculate nearly optimal detection algorithms and their Bayes risks, and we illustrate their use on numerical examples. The solution of Wiener disorder problem with discretely spaced observation times will help reduce risks and costs associated with disease outbreak and production quality control, where the observations are often collected and/or inspected periodically.
Duality Gap Estimation of Linear Equality Constrained Binary Quadratic Programming
Authors: Zheng Xiaojin , Sun Xiaoling , Li Duan , Xia Yong
Published: December 2010

We investigate in this paper the Lagrangian duality properties of linear equality constrained binary quadratic programming. We derive an underestimation of the duality gap between the primal problem and its Lagrangian dual or SDP relaxation, using the distance from the set of binary integer points to certain affine subspace, while the computation of this distance can be achieved by the cell enumeration of hyperplane arrangement. Alternative Lagrangian dual schemes via the exact penalty and the squared norm constraint reformulations are also discussed.
Potential for Electronic Health Records and Online Social Networking to Redefine Medical Research
Authors: Pearson John F , Brownstein Catherine A , Brownstein John S
Published: December 2010

BACKGROUND

Recent legislation in the US requires that all medical records become electronic over the next decade. In addition, ongoing developments in patient-oriented care, most notably with the advent of health social networking and personal health records, provide a plethora of new information sources for research.

CONTENT

Electronic health records (EHRs) show great potential for use in observational studies to examine drug safety via pharmacovigiliance methods that can find adverse drug events as well as expand drug safety profiles. EHRs also show promise for head-to-head comparative effectiveness trials and could play a critical role in secondary and tertiary diabetes prevention efforts. A growing subset of EHRs, personal health records (PHRs), opens up the possibility of engaging patients in their care, as well as new opportunities for participatory research and personalized medicine. Organizations nationwide, from providers to employers, are already investing heavily in PHR systems. Additionally, the explosive use of online social networking sites and mobile technologies will undoubtedly play a role in future research efforts by making available a veritable flood of information, such as real-time exercise monitoring, to health researchers.

The future confluence of health information technologies will enable researchers and clinicians to reveal novel therapies and insights into treatments and disease management, as well as environmental and genomic interactions, at an unprecedented population scale.
Rapid Cortical Plasticity Underlying Novel Word Learning
Authors: Shtyrov Yury , Nikulin Vadim V. , Pulvermüller Friedemann
Published: December 2010

Humans are unique in developing large lexicons as their communication tool. To achieve this, they are able to learn new words rapidly. However, neural bases of this rapid learning, which may be an expression of a more general cognitive mechanism, are not yet understood. To address this, we exposed our subjects to familiar words and novel spoken stimuli in a short passive perceptual learning session and compared automatic brain responses to these items throughout the learning exposure. Initially, we found enhanced activity for known words, indexing the ignition of their underlying memory traces. However, just after 14 min of learning exposure, the novel items exhibited a significant increase in response magnitude matching in size with that to real words. This activation increase, as we would like to propose, reflects rapid mapping of new word forms onto neural representations. Similar to familiar words, the neural activity subserving rapid learning of new word forms was generated in the left-perisylvian language cortex, especially anterior superior-temporal areas. This first report of a neural correlate of rapid learning suggests that our brain may effectively form new neuronal circuits online as it gets exposed to novel patterns in the sensory input. Understanding such fast learning is key to the neurobiological explanation of the human language faculty and learning mechanisms in general.
Medial Superior Olivary Neurons Receive Surprisingly Few Excitatory and Inhibitory Inputs with Balanced Strength and Short-Term Dynamics
Authors: Couchman Kiri , Grothe Benedikt , Felmy Felix
Published: December 2010

Neurons in the medial superior olive (MSO) process microsecond interaural time differences, the major cue for localizing low-frequency sounds, by comparing the relative arrival time of binaural, glutamatergic excitatory inputs. This coincidence detection mechanism is additionally shaped by highly specialized glycinergic inhibition. Traditionally, it is assumed that the binaural inputs are conveyed by many independent fibers, but such an anatomical arrangement may decrease temporal precision. Short-term depression on the other hand might enhance temporal fidelity during ongoing activity. For the first time we show that binaural coincidence detection in MSO neurons may require surprisingly few but strong inputs, challenging long-held assumptions about mammalian coincidence detection. This study exclusively uses adult gerbils forin vitroelectrophysiology, single-cell electroporation and immunohistochemistry to characterize the size and short-term plasticity of inputs to the MSO. We find that the excitatory and inhibitory inputs to the MSO are well balanced both in strength and short-term dynamics, redefining this fastest of all mammalian coincidence detector circuits.
LRRK2 Kinase Regulates Synaptic Morphology through Distinct Substrates at the Presynaptic and Postsynaptic Compartments of theDrosophilaNeuromuscular Junction
Authors: Lee Seongsoo , Liu Hsin-Ping , Lin Wei-Yong , Guo Huifu , Lu Bingwei
Published: December 2010

Mutations in leucine-rich repeat kinase 2 (LRRK2) are linked to familial as well as sporadic forms of Parkinson's disease (PD), a neurodegenerative disease characterized by dysfunction and degeneration of dopaminergic and other types of neurons. The molecular and cellular mechanisms underlying LRRK2 action remain poorly defined. Here, we show that LRRK2 controls synaptic morphogenesis at theDrosophilaneuromuscular junction. Loss ofDrosophilaLRRK2 results in synaptic overgrowth, whereas overexpression ofDrosophilaLRRK or human LRRK2 has opposite effects. Alteration of LRRK2 activity also affects neurotransmission. LRRK2 exerts its effects on synaptic morphology by interacting with distinct downstream effectors at the presynaptic and postsynaptic compartments. At the postsynapse, LRRK2 interacts with the previously characterized substrate 4E-BP, an inhibitor of protein synthesis. At the presynapse, LRRK2 phosphorylates and negatively regulates the microtubule (MT)-binding protein Futsch. These results implicate synaptic dysfunction caused by deregulated protein synthesis and aberrant MT dynamics in LRRK2 pathogenesis and offer a new paradigm for understanding and ultimately treating PD.
Beyond Reversal: A Critical Role for Human Orbitofrontal Cortex in Flexible Learning from Probabilistic Feedback
Authors: Tsuchida Ami , Doll Bradley B. , Fellows Lesley K.
Published: December 2010

Damage to the orbitofrontal cortex (OFC) has been linked to impaired reinforcement processing and maladaptive behavior in changing environments across species. Flexible stimulus–outcome learning, canonically captured by reversal learning tasks, has been shown to rely critically on OFC in rats, monkeys, and humans. However, the precise role of OFC in this learning remains unclear. Furthermore, whether other frontal regions also contribute has not been definitively established, particularly in humans. In the present study, a reversal learning task with probabilistic feedback was administered to 39 patients with focal lesions affecting various sectors of the frontal lobes and to 51 healthy, demographically matched control subjects. Standard groupwise comparisons were supplemented with voxel-based lesion-symptom mapping to identify regions within the frontal lobes critical for task performance. Learning in this dynamic stimulus-reinforcement environment was considered both in terms of overall performance and at the trial-by-trial level. In this challenging, probabilistic context, OFC damage disrupted both initial and reversal learning. Trial-by-trial performance patterns suggest that OFC plays a critical role in interpreting feedback from a particular trial within the broader context of the outcome history across trials rather than in simply suppressing preexisting stimulus–outcome associations. The findings show that OFC, and not other prefrontal regions, plays a necessary role in flexible stimulus–reinforcement learning in humans.
mGluR5 in Cortical Excitatory Neurons Exerts Both Cell-Autonomous and -Nonautonomous Influences on Cortical Somatosensory Circuit Formation
Authors: Ballester-Rosado Carlos J. , Albright Michael J. , Wu Chia-Shan , Liao Chun-Chieh , Zhu Jie , Xu Jian , Lee Li-Jen , Lu Hui-Chen
Published: December 2010

Glutamatergic neurotransmission plays important roles in sensory map formation. The absence of the group I metabotropic glutamate receptor 5 (mGluR5) leads to abnormal sensory map formation throughout the mouse somatosensory pathway. To examine the role of cortical mGluR5 expression on barrel map formation, we generated cortex-specific mGluR5 knock-out (KO) mice. Eliminating mGluR5 function solely in cortical excitatory neurons affects, not only the whisker-related organization of cortical neurons (barrels), but also the patterning of their presynaptic partners, the thalamocortical axons (TCAs). In contrast, subcortical whisker maps develop normally in cortical-mGluR5 KO mice. In the S1 cortex of cortical-mGluR5 KO, layer IV neurons are homogenously distributed and have no clear relationship to the location of TCA clusters. The altered dendritic morphology of cortical layer IV spiny stellate neurons in cortical-mGluR5 KO mice argues for a cell-autonomous role of mGluR5 in dendritic patterning. Furthermore, morphometric analysis of single TCAs in both cortical- and global-mGluR5 KO mice demonstrated that in these mice, the complexity of axonal arbors is reduced, while the area covered by TCA arbors is enlarged. Using voltage-clamp whole-cell recordings in acute thalamocortical brain slices, we found that KO of mGluR5 from cortical excitatory neurons reduced inhibitory but not excitatory inputs onto layer IV neurons. This suggests that mGluR5 signaling in cortical excitatory neurons nonautonomously modulates the functional development of GABAergic circuits. Together, our data provide strong evidence that mGluR5 signaling in cortical principal neurons exerts both cell-autonomous and -nonautonomous influences to modulate the formation of cortical sensory circuits.
Atypical Protein Kinase C Regulates Primary Dendrite Specification of Cerebellar Purkinje Cells by Localizing Golgi Apparatus
Authors: Tanabe Koji , Kani Shuichi , Shimizu Takashi , Bae Young-Ki , Abe Takaya , Hibi Masahiko
Published: December 2010

Neurons have highly polarized structures that determine what parts of the soma elaborate the axon and dendrites. However, little is known about the mechanisms that establish neuronal polarityin vivo. Cerebellar Purkinje cells extend a single primary dendrite from the soma that ramifies into a highly branched dendritic arbor. We used the zebrafish cerebellum to investigate the mechanisms by which Purkinje cells acquire these characteristics. To examine dendritic morphogenesis in individual Purkinje cells, we marked the cell membrane using a Purkinje cell-specific promoter to drive membrane-targeted fluorescent proteins. We found that zebrafish Purkinje cells initially extend multiple neurites from the soma and subsequently retract all but one, which becomes the primary dendrite. In addition, the Golgi apparatus specifically locates to the root of the primary dendrite, and its localization is already established in immature Purkinje cells that have multiple neurites. Inhibiting secretory trafficking through the Golgi apparatus reduces dendritic growth, suggesting that the Golgi apparatus is involved in the dendritic morphogenesis. We also demonstrated that in a mutant of an atypical protein kinase C (aPKC), Prkci, Purkinje cells retain multiple primary dendrites and show disrupted localization of the Golgi apparatus. Furthermore, a mosaic inhibition of Prkci in Purkinje cells recapitulates the aPKC mutant phenotype. These results suggest that the aPKC cell autonomously controls the Golgi localization and thereby regulates the specification of the primary dendrite of Purkinje cells.
Projection-Specific Neuromodulation of Medial Prefrontal Cortex Neurons
Authors: Dembrow Nikolai C. , Chitwood Raymond A. , Johnston Daniel
Published: December 2010

Mnemonic persistent activity in the prefrontal cortex (PFC) constitutes the neural basis of working memory. To understand how neuromodulators contribute to the generation of persistent activity, it is necessary to identify the intrinsic properties of the layer V pyramidal neurons that transfer this information to downstream networks. Here we show that the somatic dynamic and integrative properties of layer V pyramidal neurons in the rat medial PFC depend on whether they project subcortically to the pons [corticopontine (CPn)] or to the contralateral cortex [commissural (COM)]. CPn neurons display low temporal summation and accelerate in firing frequency when depolarized, whereas COM neurons have high temporal summation and display spike frequency accommodation. In response to dynamic stimuli, COM neurons act as low-pass filters, whereas CPn neurons act as bandpass filters, resonating in the theta frequency range (3–6 Hz). The disparate subthreshold properties of COM and CPn neurons can be accounted for by differences in the hyperpolarization-activated cyclic nucleotide gated cation h-current. Interestingly, neuromodulators hypothesized to enhance mnemonic persistent activity affect COM and CPn neurons distinctly. Adrenergic modulation shifts the dynamic properties of CPn but not COM neurons and increases the excitability of CPn neurons significantly more than COM neurons. In response to cholinergic modulation, CPn neurons were much more likely to display activity-dependent intrinsic persistent firing than COM neurons. Together, these data suggest that the two categories of projection neurons may subserve separate functions in PFC and may be engaged differently during working memory processes.