481 research outputs found

    Sequential analysis of social interaction: Assessing internal versus social determinants of behavior

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    Predictability and controllability of events influence attributions and affect in many research domains. In face-to-face social interaction, behavior is predictable from actor's own past behavior (internal determinants) and from partner's past behavior (social determinants). This study assessed how affect ratings are related to predictability of vocal activity from internal and social determinants. Time and frequency domain analysis of on-off vocal activity from 55 dyadic gettingacquainted conversations provided indexes of predictability from internal and social determinants. Greater predictability of vocal activity patterns from both internal and social determinants was associated with more positive affect. Future research should take internal as well as social determinants of behavior into account. The study of behavioral dialogues is emerging as an important research paradigm in social, developmental, and clinical psychology (Warner, 1991a). Investigators have examined time series data on the behavior, affect, or physiological states of social interaction partners to assess how social behavior is structured in time and how the behaviors of partners are interdependent

    How Do We Know If It Works? Measuring Outcomes in Bystander-Focused Abuse Prevention on Campuses

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    Objective: To address acknowledged limitations in the effectiveness of sexual and relationship abuse prevention strategies, practitioners have developed new tools that use a bystander framework (Lonsway et al, 2009). Evaluation of bystander-focused prevention requires measures, specific to the bystander approach, that assess changes over time in participants’ attitudes and behaviors. Few measures exist and more psychometric analyses are needed. We present analyses to begin to establish the psychometric properties of four new measures of bystander outcomes and their subscales. Method: We collected data from 948 first year college students on two campuses in the northeast United States. Items assessing attitudes and behaviors related to bystander helping responses in college campus communities for situations where there is sexual or relationship abuse risk were factor analyzed. Results: Measures of readiness to help (assessed specifically with scales representing taking action, awareness, and taking responsibility), intent to be an active bystander, self-reported bystander responses, and perceptions of peer norms in support of action all showed adequate reliability and validity. Conclusion: The study represents a next step in the development of tools that can be used by researchers and practitioners seeking both to understand bystander behavior in the context of sexual and relationship abuse and evaluating the effectiveness of prevention tools to address these problems. The measures investigated will be helpful for prevention educators and researchers evaluating the effectiveness of sexual and relationship abuse education tools that use a bystander intervention framework

    What to expect when you're expecting a hepatopancreatobiliary surgeon: self‐reported experiences of HPB surgeons from different training pathways

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    BackgroundHepatopancreatobiliary (HPB) surgery fellowship training has multiple paths. Prospective trainees and employers must understand the differences between training pathways. This study examines self‐reported fellowship experiences and current scope of practice across three pathways.MethodsAn online survey was disseminated to 654 surgeons. These included active Americas Hepato‐Pancreato‐Biliary Association (AHPBA) members and recent graduates of HPB, transplant–HPB and HPB–heavy surgical oncology fellowships.ResultsA total of 416 (64%) surgeons responded. Most respondents were male (89%) and most were practising in an academic setting (83%). 290 (70%) respondents underwent formal fellowship training. Although fellowship experiences varied, current practice was largely similar. Minimally invasive surgery (MIS) and ultrasound were the most commonly identified areas of training deficiencies and were, respectively, cited as such by 47% and 34% of HPB‐, 49% and 50% of transplant‐, and 52% and 25% of surgical oncology‐trained respondents. Non‐HPB cases performed in current practice included gastrointestinal (GI) and general surgery cases (56% and 49%, respectively) for HPB‐trained respondents, transplant and general surgery cases (87% and 21%, respectively) for transplant‐trained respondents, and GI surgery and non‐HPB surgical oncology cases (70% and 28%, respectively) for surgical oncology‐trained respondents.ConclusionsFellowship training in HPB surgery varies by training pathway. Training in MIS and ultrasound is deficient in each pathway. The ultimate scope of non‐transplant HPB practice appears similar across training pathways. Thus, training pathway choice is best guided by the training experience desired and non‐HPB components of anticipated practice.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113167/1/hpb12430.pd

    On Orbital Period Changes in Nova Outbursts

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    We propose a new mechanism that produces an orbital period change during a nova outburst. When the ejected material carries away the specific angular momentum of the white dwarf, the orbital period increases. A magnetic field on the surface of the secondary star forces a fraction of the ejected material to corotate with the star, and hence the binary system. The ejected material thus takes angular momentum from the binary orbit and the orbital period decreases. We show that for sufficiently strong magnetic fields on the surface of the secondary star, the total change to the orbital period could even be negative during a nova outburst, contrary to previous expectations. Accurate determinations of pre- and post-outburst orbital periods of recurrent nova systems could test the new mechanism, in addition to providing meaningful constraints on otherwise difficult to measure physical quantities. We apply our mechanism to outbursts of the recurrent nova U Sco.Comment: Accepted for publication in MNRA

    Tissue memory CD4+ T cells expressing IL-7 receptor-alpha (CD127) preferentially support latent HIV-1 infection.

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    The primary reservoir for HIV is within memory CD4+ T cells residing within tissues, yet the features that make some of these cells more susceptible than others to infection by HIV is not well understood. Recent studies demonstrated that CCR5-tropic HIV-1 efficiently enters tissue-derived memory CD4+ T cells expressing CD127, the alpha chain of the IL7 receptor, but rarely completes the replication cycle. We now demonstrate that the inability of HIV to replicate in these CD127-expressing cells is not due to post-entry restriction by SAMHD1. Rather, relative to other memory T cell subsets, these cells are highly prone to undergoing latent infection with HIV, as revealed by the high levels of integrated HIV DNA in these cells. Host gene expression profiling revealed that CD127-expressing memory CD4+ T cells are phenotypically distinct from other tissue memory CD4+ T cells, and are defined by a quiescent state with diminished NFÎșB, NFAT, and Ox40 signaling. However, latently-infected CD127+ cells harbored unspliced HIV transcripts and stimulation of these cells with anti-CD3/CD28 reversed latency. These findings identify a novel subset of memory CD4+ T cells found in tissue and not in blood that are preferentially targeted for latent infection by HIV, and may serve as an important reservoir to target for HIV eradication efforts
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