Bayesian Generative Modelling of Student Results in Course Networks

We present an innovative modelling technique that simultaneously constrains student performance, course difficulty, and the sensitivity with which a course can differentiate between students by means of grades. Grade lists are the only necessary ingredient. Networks of courses will be constructed where the edges are populations of students that took both connected course nodes. Using idealized experiments and two real-world data sets, we show that the model, even though simple in its set-up, can constrain the properties of courses very well, as long as some basic requirements in the data set are met: (1) significant overlap in student populations, and thus information exchange through the network; (2) non-zero variance in the grades for a given course; and (3) some correlation between grades for different courses. The model can then be used to evaluate a curriculum, a course, or even subsets of students for a very wide variety of applications, ranging from program accreditation to exam fraud detection. We publicly release the code with examples that fully recreate the results presented here

Effects of Oestrogens and FSH on LH Stimulation of Steroid Production by Testis Leydig Cells from Immature Rats

Hypophysectomy of immature male rats results after 5 days in a decreased production of testosterone by isolated testis Leydig cells in response to LH. The LH responsiveness of the Leydig cells can be partly restored by treatment of the hypophysectomized rats with FSH. In continuation of previous reports on this subject (Steroids 28 (1976) 847; and 30 (1978) the following conclusions were derived from the results in the present paper: 1. After hypophysectomy of immature male rats the production of testosterone (T) as well as of 5‐pregnenolone (Δ5P) by isolated Leydig cells in response to LH is reduced. 2. Daily administration of FSH after hypophysectomy restores the Δ5P production in response to LH almost completely, but has a much smaller effect on the restoration of T production. 3. Administration of oestradiol benzoate (E2B) together with FSH has no effect on the restoration of LH‐stimulated Δ5P production, but causes a reduction of T production, when compared with Leydig cells from animals treated with FSH only. 4. Treatment of intact immature rats with E2B results in a decreased production of T and an increased production of Δ5P in isolated Leydig cells. 5. From experiments with labelled pregnenolone it appears that E2B and diethylstilboestrol (DES) inhibit the 17α‐hydroxylase activity of Leydig cells from intact as well as from hypophysectomized rats. This results in a reduced conversion of pregnenolone to C1:)‐steroids and in increased production of 3α‐hydroxy‐5α‐pregnan‐20‐one from δ5P. 6. The observed effects of FSH and E, were similar within a dose range of 100–10000 ng LH per 106 Leydig cells. Copyrigh

Occupational physicians' perceived barriers and suggested solutions to improve adherence to a guideline on mental health problems:Analysis of a peer group training

Background Despite the impact of mental health problems on sickness absence, only few occupational health guidelines addressing these problems are available. Moreover, adherence has found to be suboptimal. To improve adherence to the Dutch guideline on mental health problems a training was developed for Dutch occupational physicians (OPs) focusing on identifying barriers and addressing them. The aim of this study was to provide an overview of the barriers that OPs perceived in adhering to the Dutch guideline on mental health problems as well as their solutions to overcome them. Methods A qualitative study was conducted using data from the peer group training. Thirty-two (6 groups of 4 to 6) OPs received a multiple-session interactive training over the course of a year, focusing on identifying and addressing barriers, using a Plan-Do-Check-Act approach. Sessions were audio-taped and transcribed verbatim. Thematic content analysis was performed by two researchers with a selection of 50 % (21 out of 42) of the transcripts to identify the perceived barriers and the suggested solutions, using AtlasTi 7.0. Results Knowledge-related barriers were perceived regarding the content of all parts of the guideline. Commonly perceived attitude-related barriers were a lack of self-efficacy to perform certain guideline recommendations and difficulties with changing habits and routines. External barriers that were commonly perceived were work-contextual barriers, such as a lack of time/work pressure, tight contracts between occupational health services (OHSs) and employers, and conflicting policy of and a lack of collaboration with other parties (e.g. employer, other healthcare providers). The most often tested solutions by OPs during the training were sharing information, experiences, tips and tricks and referring to existing tools, or developing new tools to facilitate guideline usage. Conclusions Dutch OPs perceive a range of knowledge-related, attitude-related and external barriers in adhering to the guideline on mental health problems. The tested solutions during the training particularly seemed to focus on knowledge and attitude-related barriers. To optimally implement this or similar mental health guidelines, it may be important to complement guideline training and education of individual or groups of OPs, with interventions that address external barriers such as changing tight contracts, or improving communication and collaboration with other parties. Keywords Mental health, Practice guideline, Occupational medicine, Barriers, Solutions, Implementatio

Effectiveness of an intervention to enhance occupational physicians’ guideline adherence on sickness absence duration in workers with common mental disorders:A cluster-randomized controlled trial

Purpose Evidence-based guidelines in occupational health care improve the quality of care and may reduce sickness absence duration. Notwithstanding that, guideline adherence of occupational physicians (OPs) is limited. Based on the literature on guideline implementation, an intervention was developed that was shown to effectively improve self-reported adherence in OPs. The aim of present study was to evaluate whether this intervention leads to earlier return to work (RTW) in workers with common mental disorders (CMD). Methods In a two-armed cluster randomized controlled trial, 66 OPs were randomized. The trial included 3379 workers, with 1493 in the intervention group and 1886 in the control group. The outcome measures were: time to full RTW, time to first RTW, and total hours of sickness absence. Cox regression analyses and generalized linear mixed model analyses were used for the evaluations. Results The median time to RTW was 154 days among the 3228 workers with CMD. No significant differences occurred in (time to) full RTW between intervention and control group HR 0.96 (95% CI 0.81–1.15) nor for first RTW HR 0.96 (95% CI 0.80–1.15). The mean total hours of sickness absence was 478 h in the intervention group and 483 h in the control group. Conclusions The intervention to enhance OPs’ guideline adherence did not lead to earlier RTW in workers with CMD guided by the OPs. Possible explanations are the remaining external barriers for guideline use, and that perceived guideline adherence might not represent actual guideline adherence and improved care

Robust DC and efficient time-domain fast fault simulation

Purpose – Imperfections in manufacturing processes may cause unwanted connections (faults) that are added to the nominal, "golden", design of an electronic circuit. By fault simulation one simulates all situations. Normally this leads to a large list of simulations in which for each defect a steady-state (DC) solution is determined followed by a transient simulation. We improve the robustness and the e¿iciency of these simulations. Design/methodology/approach – Determining the DC solution can be very hard. For this we present an adaptive time domain source stepping procedure that can deal with controlled sources. The method can easily be combined with existing pseudo-transient procedures. The method is robust and e¿cient. In the subsequent transient simulation the solution of a fault is compared to a golden, fault-free, solution. A strategy is developed to e¿ciently simulate the faulty solutions until their moment of detection. Finding – We fully exploit the hierarchical structure the circuit in the simulation process to bypass parts of the circuit that appear to be una¿ected by the fault. Accurate prediction and e¿cient solution procedures lead to fast fault simulation. Originality/value – Our fast fault simulation helps to store a database with detectable deviations for each fault. If such a detectable output "matches" a result of a product that has been returned because of malfunctioning it helps to identify the subcircuit that may contain the real fault. One aims to detect as much as possible candidate faults. Because of the many options the simulations must be very e¿cient

Robust DC and efficient time-domain fast fault simulation

Purpose – Imperfections in manufacturing processes may cause unwanted connections (faults) that are added to the nominal, "golden", design of an electronic circuit. By fault simulation one simulates all situations. Normally this leads to a large list of simulations in which for each defect a steady-state (DC) solution is determined followed by a transient simulation. We improve the robustness and the e¿iciency of these simulations. Design/methodology/approach – Determining the DC solution can be very hard. For this we present an adaptive time domain source stepping procedure that can deal with controlled sources. The method can easily be combined with existing pseudo-transient procedures. The method is robust and e¿cient. In the subsequent transient simulation the solution of a fault is compared to a golden, fault-free, solution. A strategy is developed to e¿ciently simulate the faulty solutions until their moment of detection. Finding – We fully exploit the hierarchical structure the circuit in the simulation process to bypass parts of the circuit that appear to be una¿ected by the fault. Accurate prediction and e¿cient solution procedures lead to fast fault simulation. Originality/value – Our fast fault simulation helps to store a database with detectable deviations for each fault. If such a detectable output "matches" a result of a product that has been returned because of malfunctioning it helps to identify the subcircuit that may contain the real fault. One aims to detect as much as possible candidate faults. Because of the many options the simulations must be very e¿cient

Informing the development of online weight management interventions:a qualitative investigation of primary care patient perceptions

Background: The internet is a potentially promising medium for delivering weight loss interventions. The current study sought to explore factors that might influence primary care patients’ initial uptake and continued use (up to four-weeks) of such programmes to help inform the development of novel, or refinement of existing, weight management interventions.Methods: Semi-structured interviews were conducted with 20 patients purposively sampled based on age, gender and BMI from a single rural general practice. The interviews were conducted 4 weeks after recruitment at the general practice and focused on experiences with using one of three freely available weight loss websites. Thematic Analysis was used to analyse the data.Results: Findings suggested that patients were initially motivated to engage with internet-based weight loss programmes by their accessibility and novelty. However, continued use was influenced by substantial facilitators and barriers, such as time and effort involved, reaction to prompts/reminders, and usefulness of information. Facilitation by face-to-face consultations with the GP was reported to be helpful in supporting change.Conclusions: Although primary care patients may not be ready yet to solely depend on online interventions for weight loss, their willingness to use them shows potential for use alongside face–to-face weight management advice or intervention. Recommendations to minimise barriers to engagement are provided