The high-intensity hyperon beam at CERN

A high-intensity hyperon beam was constructed at CERN to deliver Sigma- to experiment WA89 at the Omega facility and operated from 1989 to 1994. The setup allowed rapid changeover between hyperon and conventional hadron beam configurations. The beam provided a Sigma-flux of 1.4 x 10^5 per burst at mean momenta between 330 and 345 Gev/c, produced by about 3 x 10^10 protons of 450 GeV/c . At the experiment target the beam had a Sigma-/pi- ratio close to 0.4 and a size of 1.6 x 3.7 cm^2. The beam particle trajectories and their momenta were measured with a scintillating fibre hodoscope in the beam channel and a silicon microstrip detector at the exit of the channel. A fast transition radiation detector was used to identify the pion component of the beam.Comment: 20 pages, 13 figures. Submitted to Nucl. Instr. Meth.

Undergraduate training in breaking bad news: A continuation study exploring the patient perspective.

This paper reports on the continuation of an initial study that demonstrated the effectiveness, as rated by experts, of an undergraduate training in breaking bad news (BBN) using simulated patient (SP) and individual feedback. The current study aimed to further explore whether such an individualized training approach also has positive effects from the perspective of the patient, using the analogue patient (AP) methodology. A subsample of 180 videotaped interviews with SPs were selected from the existing data set (N = 332), consisting of 60 pre- and post-training interviews of students benefiting from the individualized approach (intervention group) and 60 post-training interviews of students having small-group SP training and collective supervision (comparison group). Sixty-eight APs-healthy untrained observers-were asked to view the videotaped interviews while "putting themselves in the patient's shoes" and evaluate satisfaction, trust, liking, and the competence of medical students. The intervention group students improved significantly from pre- to post-training on several dimensions evaluated by the APs: patient satisfaction, trust in the student, liking of the student, and perceived medical competence. Increased AP satisfaction was related to different changes in students' communication behavior between pre- and post-training: increase in positive talk, emotional responsiveness, biomedical and psychosocial information, and biomedical counseling. There was no significant between-group difference at post-training. AP evaluation showed significant improvement between pre- and post-training. This result provides additional and complementary evidence of the positive effects of individualized training in BBN from the AP perspective, a proxy of (real) patients

Core stories of physicians on a Swiss internal medicine ward during the first COVID-19 wave: a qualitative exploration.

The first COVID-19 wave (2020), W1, will remain extraordinary due to its novelty and the uncertainty on how to handle the pandemic. To understand what physicians went through, we collected narratives of frontline physicians working in a Swiss university hospital during W1. Physicians in the Division of Internal Medicine of Lausanne University Hospital (CHUV) were invited to send anonymous narratives to an online platform, between 28 April and 30 June 2020. The analysed material consisted of 13 written texts and one audio record. They were examined by means of a narrative analysis based on a holistic content approach, attempting to identify narrative highlights, referred to as foci, in the texts. Five main foci were identified: danger and threats, acquisition of knowledge and practices, adaptation to a changing context, commitment to the profession, and sense of belonging to the medical staff. In physicians' narratives, danger designated a variety of rather negative feelings and emotions, whereas threats were experienced as being dangerous for others, but also for oneself. The acquisition of knowledge and practices focus referred to the different types of acquisition that took place during W1. The narratives that focused on adaptation reflected how physicians coped with W1 and private or professional upheavals. COVID-19 W1 contributed to revealing a natural commitment (or not) of physicians towards the profession and patients, accompanied by the concern of offering the best possible care to all. Lastly, sense of belonging referred to the team and its reconfiguration during W1. Our study deepens the understanding of how physicians experienced the pandemic both in their professional and personal settings. It offers insights into how they prepared and reacted to a pandemic. The foci reflect topics that are inherent to a physician's profession, whatever the context. During a pandemic, these foundational elements are particularly challenged. Strikingly, these topics are not studied in medical school, thus raising the general question of how students are prepared for the medical profession

SU(3) Breaking in Hyperon Beta Decays: a Prediction for Xi^0 -> Sigma^+ e nu-bar

On the basis of a previous analysis of hyperon semi-leptonic decay data, a prediction is presented for g_1/f_1 in the Xi^0 -> Sigma^+ e nu-bar beta-decay. The analysis takes into account SU(3) breaking in this sector via the inclusion of mass-driven corrections. A rather precise measurement of the above channel by the KTeV experiment at Fermilab will shortly be available. Since the dependence on the SU(3) parameters, F and D, is identical to that of the neutron beta-decay, such a measurement will provide a rather stringent test of SU(3) and the models used to describe its violation in these decays. The prediction given here for the above decay is g_1/f_1=1.17, which leads to a rate of 0.80 x 10^6 s^-1 and thus a branching fraction of 2.3 x 10^-4.Comment: LaTeX, 7 pages, uses acromake, cite and topcapt packages. Non-printing extended ascii characters replaced plus minor correction

Suicides in Psychiatric Patients: Identifying Health Care-Related Factors through Clinical Practice Reviews.

The objective of this study was to identify health care-related factors associated with death by suicide in psychiatric patients and to gain insight into clinician views on how to deal with suicidality. The study material derived from a clinician committee in a psychiatric department reviewing every outpatient and inpatient suicide in a standardized way. Reports' conclusions and corresponding plenary discussion minutes regarding 94 suicides were analyzed using inductive thematic content analysis. Health care-related factors were categorized into 4 themes: patient evaluation, patient management, clinician training, and involvement of relevant non-clinical partners. Clinician views on the themes were expressed through statements (i) promoting or restricting an aspect of care (here called recommendations), which mainly followed existing guidelines and were consensual and (ii) without precise indication (here called comments), which departed from mainstream opinions or addressed topics not covered by existing policy. Involvement of non-clinical partners emerged as a new key issue for suicide prevention in psychiatric departments and should be openly discussed with patients. Clinicians preferred balanced conclusions when they reviewed suicide cases

Individual training at the undergraduate level to promote competence in breaking bad news in oncology

Training medical students in breaking bad news (BBN) in oncology may be key to improve patient care in an area where many physicians tend to be uncomfortable. Given the lack of evidence in the literature, this study aimed to assess empirically the impact of 2 teaching strategies to prepare students for the task of BBN in oncology: one-to-one simulated patient (SP) training with individual feedback (intervention group) vs small-group SP training with collective feedback (comparison group). Fourth-year students (N = 236) were randomly assigned to the intervention or comparison group. The SP videotaped interviews were analyzed with respect to BBN communication performance, rated using the Calgary-Cambridge checklist of teaching objectives for BBN; verbal interaction behaviors, coded with the Roter interaction analysis system; and 7 nonverbal behaviors. Students in the intervention group scored significantly higher after than before the training on the overall evaluation of the interview (P < .001) as well as on process skills (P < .001); they also obtained significantly higher scores compared to students in the comparison group on the overall evaluation of the interview (P < .001) and on process skills (P < .001). This study supports an individualized BBN teaching strategy and contributes to efforts to find the best way to train and reach the largest number of future physicians to improve communication competences in oncology

Analytical sensitivity of COVID-19 rapid antigen tests: A case for a robust reference standard

Aggressive diagnostic testing remains an indispensable strategy for health and aged care facilities to prevent the transmission of SARS-CoV-2 in vulnerable populations. The preferred diagnostic platform has shifted towards COVID-19 rapid antigen tests (RATs) to identify the most infectious individuals. As such, RATs are being manufactured faster than at any other time in our history yet lack the relevant quantitative analytics required to inform on absolute analytical sensitivity enabling manufacturers to maintain high batch-to-batch reproducibility, and end-users to accurately compare brands for decision making. Here, we describe a novel reference standard to measure and compare the analytical sensitivity of RATs using a recombinant GFP-tagged nucleocapsid protein (NP-GFP). Importantly, we show that the GFP tag does not interfere with NP detection and provides several advantages affording streamlined protein expression and purification in high yields as well as faster, cheaper and more sensitive quality control measures for post-production assessment of protein solubility and stability. Ten commercial COVID-19 RATs were evaluated and ranked using NP-GFP as a reference standard. Analytical sensitivity data of the selected devices as determined with NP-GFP did not correlate with those reported by the manufacturers using the median tissue culture infectious dose (TCID50) assay. Of note, TCID50 discordance has been previously reported. Taken together, our results highlight an urgent need for a reliable reference standard for evaluation and benchmarking of the analytical sensitivity of RAT devices. NP-GFP is a promising candidate as a reference standard that will ensure that RAT performance is accurately communicated to healthcare providers and the public

Sea Contributions and Nucleon Structure

We suggest a general formalism to treat a baryon as a composite system of three quarks and a `sea'. In this formalism, the sea is a cluster which can consists of gluons and quark-antiquark pairs. The hadron wave function with a sea component is given. The magnetic moments, related sum rules and axial weak coupling constants are obtained. The data seems to favor a vector sea rather than a scalar sea. The quark spin distributions in the nucleon are also discussed.Comment: 24 page

Semileptonic decay constants of octet baryons in the chiral quark-soliton model

Based on the recent study of the magnetic moments and axial constants within the framework of the chiral quark-soliton model, we investigate the baryon semileptonic decay constants $(f_1,f_2)$ and $(g_1, g_2)$. Employing the relations between the diagonal transition matrix elements and off-diagonal ones in the vector and axial-vector channels, we obtain the ratios of baryon semileptonic decay constants $f_2/f_1$ and $g_1/f_1$. The $F/D$ ratio is also discussed and found that the value predicted by the present model naturally lies between that of the Skyrme model and that of the nonrelativistic quark model. The singlet axial constant $g^{(0)}_A$ can be expressed in terms of the $F/D$ ratio and $g^{(3)}_A$ in the present model and turns out to be small. The results are compared with available experimental data and found to be in good agreement with them. In addition, the induced pseudotensor coupling constants $g_2/f_1$ are calculated, the SU(3) symmetry breaking being considered. The results indicate that the effect of SU(3) symmetry breaking might play an important role for some decay modes in hyperon semileptonic decay.Comment: 16 pages, RevTeX is used. No figure. Accepted for publication in Phys. Rev.

Experiments to Find or Exclude a Long-Lived, Light Gluino

Gluinos in the mass range ~1 1/2 - 3 1/2 GeV are absolutely excluded. Lighter gluinos are allowed, except for certain ranges of lifetime. Only small parts of the mass-lifetime parameter space are excluded for larger masses unless the lifetime is shorter than ~ 2 10^{-11} (m_{gluino}/ GeV) sec. Refined mass and lifetime estimates for R-hadrons are given, present direct and indirect experimental constraints are reviewed, and experiments to find or definitively exclude these possibilities are suggested.Comment: 27 pp, latex with 1 uufiled figure, RU-94-35. New version amplifies discussion of some points and corresponds to version for Phys. Rev.