12 research outputs found
Intra-night optical flux and polarization variability of BL~Lacertae during its 2020 2021 high state
In this work, we report the presence of rapid intra-night optical variations
in both -- flux and polarization of the blazar BL Lacertae during its
unprecedented 2020--2021 high state of brightness. The object showed
significant flux variability and some color changes, but no firmly detectable
time delays between the optical bands. The linear polarization was also highly
variable in both -- polarization degree and angle (EVPA). The object was
observed from several observatories throughout the world, covering in a total
of almost 300 hours during 66 nights. Based on our results, we suggest, that
the changing Doppler factor of an ensemble of independent emitting regions,
travelling along a curved jet that at some point happens to be closely aligned
with the line of sight can successfully reproduce our observations during this
outburst. This is one of the most extensive variability studies of the optical
polarization of a blazar on intra-night timescales.Comment: 23 pages,7 figures, 5 Tables (2 as appendix). Accepted for
publication in MNRA
Optical intra-day variability of the blazar S5 0716+714
We present an extensive recent multi-band optical photometric observations of
the blazar S5 0716+714 carried out over 53 nights with two telescopes in India,
two in Bulgaria, one in Serbia, and one in Egypt during 2019 November -- 2022
December. We collected 1401, 689, 14726, and 165 photometric image frames in B,
V, R, and I bands, respectively. We montiored the blazar quasi-simultaneously
during 3 nights in B, V, R, and I bands; 4 nights in B, V, and R; 2 nights in
V, R, and I; 5 nights in B and R; and 2 nights in V and R bands. We also took
37 nights of data only in R band. Single band data are used to study intraday
flux variability and two or more bands quasi-simultaneous observations allow us
to search for colour variation in the source. We employ the power-enhanced
F-test and the nested ANOVA test to search for genuine flux and color
variations in the light curves of the blazar on intraday timescales. Out of 12,
11, 53, and 5 nights observations, intraday variations with amplitudes between
~3% and ~20% are detected in 9, 8, 31 and 3 nights in B, V, R, and I bands,
respectively, corresponding to duty cycles of 75%, 73%, 58% and 60%. These duty
cycles are lower than those typically measured at earlier times. On these
timescales color variations with both bluer-when-brighter and
redder-when-brighter are seen, though nights with no measurable colour
variation are also present. We briefly discuss possible explanations for this
observed intraday variability.Comment: 19 pages, 5 figures, 4 tables, Accepted for Publication in MNRA
Evaluation of outcomes of a formative objective structured clinical examination for second-year UK medical students
OBJECTIVES: To explore how formative OSCEs influence student performance and perception when undertaking summative OSCEs. METHODS: We introduced formative OSCEs for second-year medical students at a large London medical school. Examination data from both formative and subsequent summative OSCEs were analysed to determine the effect on summative OSCE performance. We gathered student perceptions using an anonymous online survey tool. The data was investigated using a standard scale of 1 to 5 and qualitative analysis of free text. RESULTS: Overall, 46.6% and 85.0% of students passed the formative and summative OSCEs respectively. Formative OSCEs did not improve overall pass rates in summative OSCEs. Inclusion of an individual formative station was associated with improved performance in that station in summative OSCEs, with one exception. Formative OSCEs had a positive predictive value of 92.5% for passing the summative OSCE but limited negative predictive value. Students who passed fewer than two out of three formative OSCE stations were significantly more likely to fail the summative OSCE (78.2% vs 89.7%, p <0.001). Students felt formative OSCEs were good exam preparation and suggested logistical changes. CONCLUSION: Formative OSCEs were associated with improved performance in subsequent summative OSCEs only for identical stations. They did not improve overall pass rates in summative OSCEs, and did not predict performance well. Students viewed the formative OSCE as a positive and useful activity. However, to maximise its benefit as a tool for learning, students need better communication about the role and purpose of formative OSCEs
Responding to experienced and anticipated discrimination (READ):anti -stigma training for medical students towards patients with mental illness – study protocol for an international multisite non-randomised controlled study
Abstract Background Stigma and discrimination are a significant public health concern and cause great distress to people with mental illness. Healthcare professionals have been identified as one source of this discrimination. In this article we describe the protocol of an international, multisite controlled study, evaluating the effectiveness of READ, an anti-stigma training for medical students towards patients with mental illness. READ aims to improve students’ ability to minimise perceived discriminatory behaviours and increase opportunities for patients, therefore developing the ability of future doctors to address and challenge mental illness related discrimination. READ includes components that medical education research has shown to be effective at improving attitudes, beliefs and understanding. Methods/design READ training was developed using evidence based components associated with changes in stigma related outcomes. The study will take place in multiple international medical schools across high, middle and low income countries forming part of the INDIGO group network, with 25 sites in total. Students will be invited to participate via email from the lead researcher at each site during their psychiatry placement, and will be allocated to an intervention or a control arm according to their local teaching group at each site. READ training will be delivered solely to the intervention arm. Standardised measures will be used to assess students’ knowledge, attitudes and skills regarding discrimination in both the intervention and control groups, at baseline and at follow up immediately after the intervention. Statistical analyses of individual-level data will be conducted using random effects models accounting for clustering within sites to investigate changes in mean or percentages of each outcome, at baseline and immediately after the intervention. Discussion This is the first international study across high, middle and low income countries, which will evaluate the effectiveness of training for medical students to respond effectively to patients’ experiences and anticipation of discrimination. The results will promote implementation of manualised training that will help future doctors to reduce the impact of mental illness related discrimination on their patients. Limitations of the study are also discussed
Anti-stigma training and positive changes in mental illness stigma outcomes in medical students in ten countries: A mediation analysis on pathways via empathy development and anxiety reduction
PURPOSE: Studies of mental illness stigma reduction interventions have been criticised for failing to evaluate behavioural outcomes and mechanisms of action. This project evaluates training for medical students entitled ‘Responding to Experienced and Anticipated Discrimination’ (READ), developed to focus on skills in addition to attitudes and knowledge. We aimed to (i) evaluate the effectiveness of READ with respect to knowledge, attitudes, and clinical communication skills in responding to mental illness-related discrimination, and (ii) investigate whether its potential effectiveness was mediated via empathy or/and intergroup anxiety. METHODS: This is an international multisite non-randomised pre- vs post-controlled study. Eligible medical students were currently undertaking their rotational training in psychiatry. Thirteen sites across ten countries (n = 570) were included in the final analysis. RESULTS: READ was associated with positive changes in knowledge (mean difference 1.35; 95% CI 0.87 to 1.82), attitudes (mean difference − 2.50; 95% CI − 3.54 to − 1.46), skills (odds ratio 2.98; 95% CI 1.90 to 4.67), and simulated patient perceived empathy (mean difference 3.05; 95% CI 1.90 to 4.21). The associations of READ with knowledge, attitudes, and communication skills but not with simulated patient perceived empathy were partly mediated through student reported empathy and intergroup anxiety. CONCLUSION: This is the first study to identify mediating effects of reduced intergroup anxiety and increased empathy in an evaluation of anti-stigma training that includes behavioural measures in the form of communication skills and perceived empathy. It shows the importance of both mediators for all of knowledge, skills, and attitudes, and hence of targeting both in future interventions. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00127-022-02284-0