474 research outputs found
Modulation of emotional appraisal by false physiological feedback during fMRI
BACKGROUND
James and Lange proposed that emotions are the perception of physiological reactions. Two-level theories of emotion extend this model to suggest that cognitive interpretations of physiological changes shape self-reported emotions. Correspondingly false physiological feedback of evoked or tonic bodily responses can alter emotional attributions. Moreover, anxiety states are proposed to arise from detection of mismatch between actual and anticipated states of physiological arousal. However, the neural underpinnings of these phenomena previously have not been examined.
METHODOLOGY/PRINCIPAL FINDINGS
We undertook a functional brain imaging (fMRI) experiment to investigate how both primary and second-order levels of physiological (viscerosensory) representation impact on the processing of external emotional cues. 12 participants were scanned while judging face stimuli during both exercise and non-exercise conditions in the context of true and false auditory feedback of tonic heart rate. We observed that the perceived emotional intensity/salience of neutral faces was enhanced by false feedback of increased heart rate. Regional changes in neural activity corresponding to this behavioural interaction were observed within included right anterior insula, bilateral mid insula, and amygdala. In addition, right anterior insula activity was enhanced during by asynchronous relative to synchronous cardiac feedback even with no change in perceived or actual heart rate suggesting this region serves as a comparator to detect physiological mismatches. Finally, BOLD activity within right anterior insula and amygdala predicted the corresponding changes in perceived intensity ratings at both a group and an individual level.
CONCLUSIONS/SIGNIFICANCE
Our findings identify the neural substrates supporting behavioural effects of false physiological feedback, and highlight mechanisms that underlie subjective anxiety states, including the importance of the right anterior insula in guiding second-order "cognitive" representations of bodily arousal state
Modulation of emotional appraisal by false physiological feedback during fMRI
BACKGROUND
James and Lange proposed that emotions are the perception of physiological reactions. Two-level theories of emotion extend this model to suggest that cognitive interpretations of physiological changes shape self-reported emotions. Correspondingly false physiological feedback of evoked or tonic bodily responses can alter emotional attributions. Moreover, anxiety states are proposed to arise from detection of mismatch between actual and anticipated states of physiological arousal. However, the neural underpinnings of these phenomena previously have not been examined.
METHODOLOGY/PRINCIPAL FINDINGS
We undertook a functional brain imaging (fMRI) experiment to investigate how both primary and second-order levels of physiological (viscerosensory) representation impact on the processing of external emotional cues. 12 participants were scanned while judging face stimuli during both exercise and non-exercise conditions in the context of true and false auditory feedback of tonic heart rate. We observed that the perceived emotional intensity/salience of neutral faces was enhanced by false feedback of increased heart rate. Regional changes in neural activity corresponding to this behavioural interaction were observed within included right anterior insula, bilateral mid insula, and amygdala. In addition, right anterior insula activity was enhanced during by asynchronous relative to synchronous cardiac feedback even with no change in perceived or actual heart rate suggesting this region serves as a comparator to detect physiological mismatches. Finally, BOLD activity within right anterior insula and amygdala predicted the corresponding changes in perceived intensity ratings at both a group and an individual level.
CONCLUSIONS/SIGNIFICANCE
Our findings identify the neural substrates supporting behavioural effects of false physiological feedback, and highlight mechanisms that underlie subjective anxiety states, including the importance of the right anterior insula in guiding second-order "cognitive" representations of bodily arousal state
Study of cosolvent-induced α-chymotrypsin fibrillogenesis: Does protein surface hydrophobicity trigger early stages of aggregation reaction?
The misfolding of specific proteins is often associated with their assembly into fibrillar aggregates, commonly termed amyloid fibrils. Despite the many efforts expended to characterize amyloid formation in vitro, there is no deep knowledge about the environment (in which aggregation occurs) as well as mechanism of this type of protein aggregation. Alpha-chymotrypsin was recently driven toward amyloid aggregation by the addition of intermediate concentrations of trifluoroethanol. In the present study, approaches such as turbidimetric, thermodynamic, intrinsic fluorescence and quenching studies as well as chemical modification have been successfully used to elucidate the underlying role of hydrophobic interactions (involved in early stages of amyloid formation) in α-chymotrypsin-based experimental system. © 2009 Springer Science+Business Media, LLC
Practicing doctors' perceptions on new learning objectives for Vietnamese medical schools
<p>Abstract</p> <p>Background</p> <p>As part of the process to develop more community-oriented medical teaching in Vietnam, eight medical schools prepared a set of standard learning objectives with attention to the needs of a doctor working with the community. Because they were prepared based on government documents and the opinions of the teachers, it was necessary to check them with doctors who had already graduated and were working at different sites in the community.</p> <p>Methods</p> <p>Each of the eight medical faculties asked 100 practising recent graduates to complete a questionnaire to check the relevance of the skills that the teachers considered most important. We used mean and standard deviation to summarize the scores rated by the respondents for each skill and percentile at four points: p50, p25, p10 and p5 to describe the variation of scores among the respondents. Correlation coefficient was used to measure the relationship between skill levels set by the teachers and the perception of practicing doctors regarding frequency of using skills and priority for each skill. Additional information was taken from the records of focus group discussions to clarify, explain or expand on the results from the quantitative data.</p> <p>Results</p> <p>In many cases the skills considered important by teachers were also rated as highly necessary and/or frequently used by the respondents. There were, however, discrepancies: some skills important to teachers were seldom used and not considered important by the doctors. In focus group discussions the doctors also identified skills that are not taught at all in the medical schools but would be needed by practising doctors. </p> <p>Conclusion</p> <p>Although most of the skills and skill levels included in the learning objectives by the teachers were consistent with the opinions of their graduates, the match was not perfect. The experience of the graduates and their additional comments should be included as inputs to the definition of learning objectives for medical students.</p
Wild chimpanzees modify modality of gestures according to the strength of social bonds and personal network size
Primates form strong and enduring social bonds with others and these bonds have important fitness consequences. However, how different types of communication are associated with different types of social bonds is poorly understood. Wild chimpanzees have a large repertoire of gestures, from visual gestures to tactile and auditory gestures. We used social network analysis to examine the association between proximity bonds (time spent in close proximity) and rates of gestural communication in pairs of chimpanzees when the intended recipient was within 10 m of the signaller. Pairs of chimpanzees with strong proximity bonds had higher rates of visual gestures, but lower rates of auditory long-range and tactile gestures. However, individual chimpanzees that had a larger number of proximity bonds had higher rates of auditory and tactile gestures and lower rates of visual gestures. These results suggest that visual gestures may be an efficient way to communicate with a small number of regular interaction partners, but that tactile and auditory gestures may be more effective at communicating with larger numbers of weaker bonds. Increasing flexibility of communication may have played an important role in managing differentiated social relationships in groups of increasing size and complexity in both primate and human evolution
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
The Role of Medical Education in Reducing Health Care Disparities: The First Ten Years of the UCLA/Drew Medical Education Program
BACKGROUND: The University of California, Los Angeles (UCLA)/Charles R. Drew University Medical Education Program was developed to train physicians for practice in underserved areas. The UCLA/Drew Medical Education Program students receive basic science instruction at UCLA and complete their required clinical rotations in South Los Angeles, an impoverished urban community. We have previously shown that, in comparison to their UCLA counterparts, students in the Drew program had greater odds of maintaining their commitment to medically disadvantaged populations over the course of medical education. OBJECTIVE: To examine the independent association of graduation from the UCLA/Drew program with subsequent choice of physician practice location. We hypothesized that participation in the UCLA/Drew program predicts future practice in medically disadvantaged areas, controlling for student demographics such as race/ethnicity and gender, indicators of socioeconomic status, and specialty choice. DESIGN: Retrospective cohort study. PARTICIPANTS: Graduates (1,071) of the UCLA School of Medicine and the UCLA/Drew Medical Education Program from 1985–1995, practicing in California in 2003 based on the address listed in the American Medical Association (AMA) Physician Masterfile. MEASUREMENTS: Physician address was geocoded to a California Medical Service Study Area (MSSA). A medically disadvantaged community was defined as meeting any one of the following criteria: (a) federally designated HPSA or MUA; (b) rural area; (c) high minority area; or (d) high poverty area. RESULTS: Fifty-three percent of UCLA/Drew graduates are located in medically disadvantaged areas, in contrast to 26.1% of UCLA graduates. In multivariate analyses, underrepresented minority race/ethnicity (OR: 1.57; 95% CI: 1.10–2.25) and participation in the Drew program (OR: 2.47; 95% CI: 1.59–3.83) were independent predictors of future practice in disadvantaged areas. CONCLUSIONS: Physicians who graduated from the UCLA/Drew Medical Education Program have higher odds of practicing in underserved areas than those who completed the traditional UCLA curriculum, even after controlling for other factors such as race/ethnicity. The association between participation in the UCLA/Drew Medical Education Program and physician practice location suggests that medical education programs may reinforce student goals to practice in disadvantaged communities
Diversification of U.S. medical schools via affirmative action implementation
BACKGROUND: The diversification of medical school student and faculty bodies via race-conscious affirmative action policy is a societal and legal option for the U.S. Supreme Court has recently ruled its use constitutional. This paper investigates the implications of affirmative action, particularly race-conscious compared to race-blind admissions policy; explains how alternative programs are generally impractical; and provides a brief review of the history and legality of affirmative action in the United States. DISCUSSION: Selection based solely on academic qualifications such as GPA and MCAT scores does not achieve racial and ethnic diversity in medical school, nor does it adequately predict success as practicing physicians. However, race-conscious preference yields greater practice in underserved and often minority populations, furthers our biomedical research progression, augments health care for minority patients, and fosters an exceptional medical school environment where students are better able to serve an increasingly multicultural society. SUMMARY: The implementation of race-conscious affirmative action results in diversity in medicine. Such diversity has shown increased medical practice in underserved areas, thereby providing better health care for the American people
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