1,086 research outputs found
A Content Analysis of Interviewee Reports of Medical School Admissions Interviews
Introduction. Prospective medical school applicants use Internet websites to gain information about medical school interviews as well as to offer their experience in such interviews. This study examined applicants’ reported experiences of interviews and compared them to the purposes of the interview as purported by medical schools.
Method. Content analysis of student feedback regarding medical school interviews at 161 medical schools was conducted for entries of over 4600 students applying to medical school who anonymously and voluntarily completed an online questionnaire.
Results. Across all medical schools, nearly one half of all cited interview questions addressed non-cognitive characteristics of the applicants. Top ranked medical schools were reported to ask significantly more interpersonal and illegal questions and fewer academic/general knowledge questions than other medical schools. Lower ranked schools did not differ significantly in the types of questions reportedly asked applicants compared to other medical schools.
Discussion. Medical school interviews are generally gathering types of information about applicants that admissions personnel identify as important in the admission decision. In addition to measuring interpersonal characteristics, medical school admissions interviews are assessing cognitive abilities and ethical decision-making. Sources on the Internet provide actual medical school interview questions to prospective students. This practice can help them gain an undue advantage in interviewing. Admissions committees and faculty who interview students may want to consider how best to obtain accurate and valid responses from applicants
Brain Activation Patterns during Visual Scene Encoding and Recognition fMRI Tasks in Early Phase Psychosis
poster abstractSchizophrenia is a chronic and disabling illness that is associated with significant impairments in areas such as independent living, social functioning, and vocational functioning. Cognitive dysfunction is a core facet of schizophrenia with deficits occurring in areas of abstraction, attention, language, and memory. Episodic memory (EM) is a cognitive domain that has been shown to be impaired in schizophrenia. EM combines event-specific autobiographical experiences and information regarding the context in which events took place. Patients with schizophrenia may exhibit broad impairments in EM, with deficits occurring during encoding and retrieval with both visual and verbal tasks. There are a number of inconsistencies in the EM fMRI literature and indicating a need for first episode psychosis (FEP) versus chronic phase schizophrenia research. FEP have fewer and less severe medical comorbidities, shorter durations of antipsychotic treatment exposure, and lower severity of illness, all of which can impact data interpretation. In this study, brain activation patterns were assessed during performance of visual scene encoding and recognition fMRI tasks in FEP patients and healthy control subjects. It is hypothesized that FEP patients would demonstrate decreased activation during encoding and recognition in the main areas that mediate EM function, namely the hippocampus, prefrontal, and parietal cortices. Within the FEP group correlations can be determined by comparing brain activation patterns with cognition (Brief Assessment of Cognition in Schizophrenia [BACS]) and symptom (Positive and Negative Syndrome Scale [PANSS]) outcome measures. Results indicate that during the encoding task FEP exhibited significantly lower activation in the hippocampus and fusiform gyrus when compared to controls. During the recognition task FEP showed a significantly weaker cortical response in the posterior cingulate cortex, the precuneus, and the left middle temporal cortex when compared to controls. These results demonstrate a pattern of alteration in hippocampal, parietal, and temporal activity during EM processes in FEP. Altered hippocampal response in FEP may reflect dysfunctional binding mechanisms and less efficient encoding
Metacognition in Early Phase Psychosis: Toward Understanding Neural Substrates
Individuals in the early phases of psychotic illness have disturbed metacognitive capacity, which has been linked to a number of poor outcomes. Little is known, however, about the neural systems associated with metacognition in this population. The purpose of this study was to elucidate the neuroanatomical correlates of metacognition. We anticipated that higher levels of metacognition may be dependent upon gray matter density (GMD) of regions within the prefrontal cortex. Examining whole-brain structure in 25 individuals with early phase psychosis, we found positive correlations between increased medial prefrontal cortex and ventral striatum GMD and higher metacognition. These findings represent an important step in understanding the path through which the biological correlates of psychotic illness may culminate into poor metacognition and, ultimately, disrupted functioning. Such a path will serve to validate and promote metacognition as a viable treatment target in early phase psychosis
Viruses infecting a warm water picoeukaryote shed light on spatial co-occurrence dynamics of marine viruses and their hosts
The marine picoeukaryote Bathycoccus prasinos has been considered a cosmopolitan alga, although recent studies indicate two ecotypes exist, Clade BI (B. prasinos) and Clade BII. Viruses that infect Bathycoccus Clade BI are known (BpVs), but not that infect BII. We isolated three dsDNA prasinoviruses from the Sargasso Sea against Clade BII isolate RCC716. The BII-Vs do not infect BI, and two (BII-V2 and BII-V3) have larger genomes (~210 kb) than BI-Viruses and BII-V1. BII-Vs share ~90% of their proteins, and between 65% to 83% of their proteins with sequenced BpVs. Phylogenomic reconstructions and PolB analyses establish close-relatedness of BII-V2 and BII-V3, yet BII-V2 has 10-fold higher infectivity and induces greater mortality on host isolate RCC716. BII-V1 is more distant, has a shorter latent period, and infects both available BII isolates, RCC716 and RCC715, while BII-V2 and BII-V3 do not exhibit productive infection of the latter in our experiments. Global metagenome analyses show Clade BI and BII algal relative abundances correlate positively with their respective viruses. The distributions delineate BI/BpVs as occupying lower temperature mesotrophic and coastal systems, whereas BII/BII-Vs occupy warmer temperature, higher salinity ecosystems. Accordingly, with molecular diagnostic support, we name Clade BII Bathycoccus calidus sp. nov. and propose that molecular diversity within this new species likely connects to the differentiated host-virus dynamics observed in our time course experiments. Overall, the tightly linked biogeography of Bathycoccus host and virus clades observed herein supports species-level host specificity, with strain-level variations in infection parameters
Abnormal P300 in people with high risk of developing psychosis
Background
Individuals with an “at-risk mental state” (or “prodromal” symptoms) have a 20–40% chance of developing psychosis; however it is difficult to predict which of them will become ill on the basis of their clinical symptoms alone. We examined whether neurophysiological markers could help to identify those who are particularly vulnerable.
Method
35 cases meeting PACE criteria for the at-risk mental state (ARMS) and 57 controls performed an auditory oddball task whilst their electroencephalogram was recorded. The latency and amplitude of the P300 and N100 waves were compared between groups using linear regression.
Results
The P300 amplitude was significantly reduced in the ARMS group [8.6 ± 6.4 microvolt] compared to controls [12.7 ± 5.8 microvolt] (p < 0.01). There were no group differences in P300 latency or in the amplitude and latency of the N100. Of the at-risk subjects that were followed up, seven (21%) developed psychosis.
Conclusion
Reduction in the amplitude of the P300 is associated with an increased vulnerability to psychosis. Neurophysiological and other biological markers may be of use to predict clinical outcomes in populations at high risk
Functional network connectivity in early-stage schizophrenia
Schizophrenia is a disorder of altered neural connections resulting in impaired information integration. Whole brain assessment of within- and between-network connections may determine how information processing is disrupted in schizophrenia. Patients with early-stage schizophrenia (n = 56) and a matched control sample (n = 32) underwent resting-state fMRI scans. Gray matter regions were organized into nine distinct functional networks. Functional connectivity was calculated between 278 gray matter regions for each subject. Network connectivity properties were defined by the mean and variance of correlations of all regions. Whole-brain network measures of global efficiency (reflecting overall interconnectedness) and locations of hubs (key regions for communication) were also determined. The control sample had greater connectivity between the following network pairs: somatomotor-limbic, somatomotor-default mode, dorsal attention-default mode, ventral attention-limbic, and ventral attention-default mode. The patient sample had greater variance in interactions between ventral attention network and other functional networks. Illness duration was associated with overall increases in the variability of network connections. The control group had higher global efficiency and more hubs in the cerebellum network, while patient group hubs were more common in visual, frontoparietal, or subcortical networks. Thus, reduced functional connectivity in patients was largely present between distinct networks, rather than within-networks. The implications of these findings for the pathophysiology of schizophrenia are discussed
Incarceration history and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis
Background
People who inject drugs (PWID) experience a high prevalence of incarceration and might be at high risk of HIV and hepatitis C virus (HCV) infection during or after incarceration. We aimed to assess whether incarceration history elevates HIV or HCV acquisition risk among PWID.
Methods
In this systematic review and meta-analysis, we searched MEDLINE, Embase, and PsycINFO databases for studies in any language published from Jan 1, 2000 until June 13, 2017 assessing HIV or HCV incidence among PWID. We included studies that measured HIV or HCV incidence among community-recruited PWID. We included only studies reporting original results and excluded studies that evaluated incident infections by self-report. We contacted authors of cohort studies that met the inclusion or exclusion criteria, but that did not report on the outcomes of interest, to request data. We extracted and pooled data from the included studies using random-effects meta-analyses to quantify the associations between recent (past 3, 6, or 12 months or since last follow-up) or past incarceration and HIV or HCV acquisition (primary infection or reinfection) risk among PWID. We assessed the risk of bias of included studies using the Newcastle-Ottawa Scale. Between-study heterogeneity was evaluated using the I2 statistic and the P-value for heterogeneity.
Findings
We included published results from 20 studies and unpublished results from 21 studies. These studies originated from Australasia, western and eastern Europe, North and Latin America, and east and southeast Asia. Recent incarceration was associated with an 81% (relative risk [RR] 1·81, 95% CI 1·40–2·34) increase in HIV acquisition risk, with moderate heterogeneity between studies (I2=63·5%; p=0·001), and a 62% (RR 1·62, 95% CI 1·28–2·05) increase in HCV acquisition risk, also with moderate heterogeneity between studies (I2=57·3%; p=0·002). Past incarceration was associated with a 25% increase in HIV (RR 1·25, 95% CI 0·94–1·65) and a 21% increase in HCV (1·21, 1·02–1·43) acquisition risk.
Interpretation
Incarceration is associated with substantial short-term increases in HIV and HCV acquisition risk among PWID and could be a significant driver of HCV and HIV transmission among PWID. These findings support the need for developing novel interventions to minimise the risk of HCV and HIV acquisition, including addressing structural risks associated with drug laws and excessive incarceration of PWID
Bench- and Pilot-Scale Studies of Reaction and Regeneration of Ni–Mg–K/Al2O3 for Catalytic Conditioning of Biomass-Derived Syngas
Diagnosis of obstructive coronary artery disease using computed tomography angiography in patients with stable chest pain depending on clinical probability and in clinically important subgroups: meta-analysis of individual patient data
OBJECTIVE:
To determine whether coronary computed tomography angiography (CTA) should be performed in patients with any clinical probability of coronary artery disease (CAD), and whether the diagnostic performance differs between subgroups of patients.
DESIGN:
Prospectively designed meta-analysis of individual patient data from prospective diagnostic accuracy studies.
DATA SOURCES:
Medline, Embase, and Web of Science for published studies. Unpublished studies were identified via direct contact with participating investigators.
ELIGIBILITY CRITERIA FOR SELECTING STUDIES:
Prospective diagnostic accuracy studies that compared coronary CTA with coronary angiography as the reference standard, using at least a 50% diameter reduction as a cutoff value for obstructive CAD. All patients needed to have a clinical indication for coronary angiography due to suspected CAD, and both tests had to be performed in all patients. Results had to be provided using 2×2 or 3×2 cross tabulations for the comparison of CTA with coronary angiography. Primary outcomes were the positive and negative predictive values of CTA as a function of clinical pretest probability of obstructive CAD, analysed by a generalised linear mixed model; calculations were performed including and excluding non-diagnostic CTA results. The no-treat/treat threshold model was used to determine the range of appropriate pretest probabilities for CTA. The threshold model was based on obtained post-test probabilities of less than 15% in case of negative CTA and above 50% in case of positive CTA. Sex, angina pectoris type, age, and number of computed tomography detector rows were used as clinical variables to analyse the diagnostic performance in relevant subgroups.
RESULTS:
Individual patient data from 5332 patients from 65 prospective diagnostic accuracy studies were retrieved. For a pretest probability range of 7-67%, the treat threshold of more than 50% and the no-treat threshold of less than 15% post-test probability were obtained using CTA. At a pretest probability of 7%, the positive predictive value of CTA was 50.9% (95% confidence interval 43.3% to 57.7%) and the negative predictive value of CTA was 97.8% (96.4% to 98.7%); corresponding values at a pretest probability of 67% were 82.7% (78.3% to 86.2%) and 85.0% (80.2% to 88.9%), respectively. The overall sensitivity of CTA was 95.2% (92.6% to 96.9%) and the specificity was 79.2% (74.9% to 82.9%). CTA using more than 64 detector rows was associated with a higher empirical sensitivity than CTA using up to 64 rows (93.4% v 86.5%, P=0.002) and specificity (84.4% v 72.6%, P<0.001). The area under the receiver-operating-characteristic curve for CTA was 0.897 (0.889 to 0.906), and the diagnostic performance of CTA was slightly lower in women than in with men (area under the curve 0.874 (0.858 to 0.890) v 0.907 (0.897 to 0.916), P<0.001). The diagnostic performance of CTA was slightly lower in patients older than 75 (0.864 (0.834 to 0.894), P=0.018 v all other age groups) and was not significantly influenced by angina pectoris type (typical angina 0.895 (0.873 to 0.917), atypical angina 0.898 (0.884 to 0.913), non-anginal chest pain 0.884 (0.870 to 0.899), other chest discomfort 0.915 (0.897 to 0.934)).
CONCLUSIONS:
In a no-treat/treat threshold model, the diagnosis of obstructive CAD using coronary CTA in patients with stable chest pain was most accurate when the clinical pretest probability was between 7% and 67%. Performance of CTA was not influenced by the angina pectoris type and was slightly higher in men and lower in older patients.
SYSTEMATIC REVIEW REGISTRATION:
PROSPERO CRD42012002780
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