What patients with bipolar disorder and major depressive disorder perceive as adverse life events precipitating a current major depressive episode

BACKGROUND : Adverse life events (ALEs) as precipitants of a major depressive episode (MDE) have been the subject of many studies. These studies indicate an increase in ALEs in the 6 months preceding an MDE. OBJECTIVES : The study examined what participants, suffering from major depressive disorder (MDD) or bipolar disorder (BD), perceived as the precipitating ALE of a current MDE. The severity and categories of ALEs were compared between these two patient groups. METHODS : Consenting, adult inpatients were sourced from Weskoppies Hospital, Steve Biko Academic Hospital, Tshwane District Hospital, Denmar Psychiatric Hospital and Vista Clinic in the Pretoria area. A semi-structured questionnaire was used to obtain demographic data and the diagnosis. Information regarding the course of the disorder, including the number of previous MDEs and the age at which the first MDE occurred, was also obtained. The perceived precipitating ALE was detailed for each participant. A severity value referred to as a Life Change Unit Score (LCU score), based on the Recent Life Changes Questionnaire (RLCQ) by Miller and Rahe, was then assigned to each participant’s perceived precipitant. RESULTS : Of the 64 participants, 12.7 % were experiencing a first MDE. In those participants who had experienced prior episodes the average number (standard deviation (SD)) of previous episodes was 3.86 (2.46). The mean approximate age (SD) at first onset of an MDE was 24.81 (10.9) years. The BD group had significantly more previous MDEs than the MDD group. Although the average LCU scores were higher in the BD group than the MDD group this did not reach statistical significance. Therefore, this study could not find a difference in the severity of the perceived precipitants between the BD group and MDD group. However, when the LCU scores were analysed within subcategories of the RLCQ, it was found that participants with BD perceived significantly more problems associated with the workplace as precipitants of a current MDE than individuals with MDD. CONCLUSION : Most participants could link an ALE to the onset of a current MDE. The study did not find a differential response to ALEs between patients with BD and MDD. The severity of the social precipitants did not differ significantly between the two groups. The notion of a ‘kindling effect’ could not be supported by the outcome of this study. Because some study participants experienced ALEs not accounted for by the RLCQ, a more comprehensive assessment instrument may be more appropriate for similar studies.http://www.sajp.org.za/index.php/sajphb201

A new lab facility for measuring bidirectional reflectance/emittance distribution functions of soils and canopies

Recently, a laboratory measurement facility has been realized for assessing the anisotropic reflectance and emittance behaviour of soils, leaves and small canopies under controlled illumination conditions. The facility consists of an ASD FieldSpec 3 spectroradiometer covering the spectral range from 350 – 2500 nm at 1 nm spectral sampling interval. The spectroradiometer is deployed using a fiber optic cable with either a 1°, 8° or 25° instantaneous field of view (IFOV). These measurements can be used to assess the plant pigment (chlorophyll, xanthophyll, etc.) and non-pigment system (water, cellulose, lignin, nitrogen, etc.). The thermal emittance is measured using a NEC TH9100 Infrared Thermal Imager. It operates in a single band covering the spectral range from 8 – 14 mm with a resolution of 0.02 K. Images are 320 (H) by 240 (V) pixels with an IFOV of 1.2 mrad. A 1000 W Quartz Tungsten Halogen (QTH) lamp is used as illumination source, approximating the radiance distribution of the sun. This one is put at a fixed position during a measurement session. Multi-angular measurements are achieved by using a robotic positioning system allowing to perform either reflectance or emittance measurements over almost a complete hemisphere. The hemisphere can be sampled continuously between 0° and 80° from nadir and up to a few degrees from the hot-spot configuration (depending on the IFOV of the measurement device) for a backscattering target. Measurement distance to targets can be varied between 0.25 and 1 m, although with a distance of more than 0.6 m it is not possible to cover the full hemisphere. The goal is to infer the BRDF (bidirectional reflectance distribution function) and BTDF (bidirectional thermal distribution function) from these multi-angular measurements for various surface types (like soils, agricultural crops, small tree canopies and artificial objects) and surface roughness. The steering of the robotic arm and the reading of the spectroradiometer and the thermal camera are all fully automated

Improving Patient Pre-screening for Clinical Trials: Assisting Physicians with Large Language Models

Physicians considering clinical trials for their patients are met with the laborious process of checking many text based eligibility criteria. Large Language Models (LLMs) have shown to perform well for clinical information extraction and clinical reasoning, including medical tests, but not yet in real-world scenarios. This paper investigates the use of InstructGPT to assist physicians in determining eligibility for clinical trials based on a patient's summarised medical profile. Using a prompting strategy combining one-shot, selection-inference and chain-of-thought techniques, we investigate the performance of LLMs on 10 synthetically created patient profiles. Performance is evaluated at four levels: ability to identify screenable eligibility criteria from a trial given a medical profile; ability to classify for each individual criterion whether the patient qualifies; the overall classification whether a patient is eligible for a clinical trial and the percentage of criteria to be screened by physician. We evaluated against 146 clinical trials and a total of 4,135 eligibility criteria. The LLM was able to correctly identify the screenability of 72% (2,994/4,135) of the criteria. Additionally, 72% (341/471) of the screenable criteria were evaluated correctly. The resulting trial level classification as eligible or ineligible resulted in a recall of 0.5. By leveraging LLMs with a physician-in-the-loop, a recall of 1.0 and precision of 0.71 on clinical trial level can be achieved while reducing the amount of criteria to be checked by an estimated 90%. LLMs can be used to assist physicians with pre-screening of patients for clinical trials. By forcing instruction-tuned LLMs to produce chain-of-thought responses, the reasoning can be made transparent to and the decision process becomes amenable by physicians, thereby making such a system feasible for use in real-world scenarios.Comment: 11 pages, 4 tables, 2 figure

A case-based, small-group cooperative learning course in preclinical veterinary science aimed at bridging basic science and clinical literacy

In 1999 a dedicated problem-based learning course was introduced into the lecture-based preclinical veterinary curriculum of the University of Pretoria. The Introduction to Clinical Studies Course combines traditional lectures, practical sessions, student self-learning and guided tutorials. The self-directed component of the course utilises case-based, small group cooperative learning as an educational vehicle to link basic science with clinical medicine. The aim of this article is to describe the objectives and structure of the course and to report the results of the assessment of the students' perceptions on some aspects of the course. Students reacted very positively to the ability of the course to equip them with problem-solving skills. Students indicated positive perceptions about the workload of the course. There were, however, significantly lower scores for the clarity of the course objectives. Although the study guide for the course is very comprehensive, the practice regarding the objectives is still uncertain. It is imperative to set clear objectives in non-traditional, student-centred courses. The objectives have to be explained at the outset and reiterated throughout the course. Tutors should also communicate the rationale behind problem based learning as a pedagogical method to the students. Further research is needed to verify the effectiveness of this course in bridging the gap between basic science and clinical literacy in veterinary science. Ongoing feedback and assessment of the management and content are important to refine this model for integrating basic science with clinical literacy

Acceptance and compliance with external hip protectors: A systematic review of the literature

Hip fractures may be prevented by the use of external hip protectors, but compliance is often poor. Therefore, the objective of this study was to assess the determinants of compliance with hip protectors by systematically reviewing the literature. A literature search was performed in PubMed, Embase and the Cochrane Library. Primary acceptance with hip protectors ranged from 37% to 72% (median 68%); compliance varied between 20% and 92% (median 56%). However, in most studies it was not very clear how compliance was defined (e.g., average wearing time on active days and during waking hours, number of user-days per all available follow-up days, percentage falls with hip protector) and how it was measured. To provide more insight in the compliance percentages, the different methods of defining and measuring compliance were presented for the selected studies, when provided. Because of the heterogeneity in study design of the selected studies and the lack of quantitative data in most studies, results regarding the determinants of compliance could not be statistically pooled. Instead a qualitative summary of the determinants of compliance was given. The reasons most frequently mentioned for not wearing hip protectors, were: not being comfortable (too tight/poor fit); the extra effort (and time) needed to wear the device; urinary incontinence; and physical difficulties/illnesses. In conclusion, compliance is a very complex, but important issue in hip protector research and implementation. Based on the experiences of elderly people who wear the hip protectors, adjustments should be made to the protector and the underwear, while maintaining the force attenuation capacity. Furthermore, methods to improve the compliance should be developed, and their effectiveness tested. (aut.ref.

Participatory Experimentation with Energy Law:Digging in a ‘Regulatory Sandbox’ for Local Energy Initiatives in the Netherlands

To facilitate energy transition, regulators have devised ‘regulatory sandboxes’ to create a participatory experimentation environment for exploring revision of energy law in several countries. These sandboxes allow for a two-way regulatory dialogue between an experimenter and an approachable regulator to innovate regulation and enable new socio-technical arrangements. However, these experiments do not take place in a vacuum but need to be formulated and implemented in a multi-actor, polycentric decision-making system through collaboration with the regulator but also energy sector incumbents, such as the distribution system operator. Therefore, we are exploring new roles and power division changes in the energy sector as a result of such a regulatory sandbox. We researched the Dutch executive order ‘experiments decentralized, sustainable electricity production’ (EDSEP) that invites homeowners’ associations and energy cooperatives to propose projects that are prohibited by extant regulation. Local experimenters can, for instance, organise peer-to-peer supply and determine their own tariffs for energy transport in order to localize, democratize, and decentralize energy provision. Theoretically, we rely on Ostrom’s concept of polycentricity to study the dynamics between actors that are involved in and engaging with the participatory experiments. Empirically, we examine four approved EDSEP experiments through interviews and document analysis. Our conclusions focus on the potential and limitations of bottom-up, participatory innovation in a polycentric system. The most important lessons are that a more holistic approach to experimentation, inter-actor alignment, providing more incentives, and expert and financial support would benefit bottom-up participatory innovation

Ion cyclotron wall conditioning experiments on Tore Supra in presence of the toroidal magnetic field

Wall conditioning techniques applicable in the presence of the high toroidal magnetic field will be required for the operation of ITER for tritium removal, isotopic ratio control and recovery to normal operation after disruptions. Recently ion cyclotron wall conditioning (ICWC) experiments have been carried out on Tore Supra in order to assess the efficiency of this technique in ITER relevant conditions. The ICRF discharges were operated in He/H-2 Mixtures at the Tore Supra nominal field (3.8 T) and a RF frequency of 48 MHz, i.e. within the ITER operational space. RF pulses of 60 s (max.) were applied using a standard Tore Supra two-strap resonant double loop antenna in ICWC mode, operated either in pi or 0-phasing with a noticeable improvement of the RF coupling in the latter case. In order to assess the efficiency of the technique for the control of isotopic ratio the wall was first preloaded using a D-2 glow discharge. After 15 minutes of ICWC in He/H-2 gas mixtures the isotopic ratio was altered from 4% to 50% at the price of an important H implantation into the walls. An overall analysis comparing plasma production and the conditioning efficiency as a function of discharge parameters is given