Phase I and Phase II control charts for the variance and generalized variance

By extending the results of Human, Chakraborti and Smit (2010), Phase I control charts are derived for the generalized variance when the mean vector and covariance matrix of multivariate normally distributed data are unknown and estimated from m independent samples, each of size n. In Phase II predictive distributions based on a Bayesian approach are used to construct Shewart-type control limits for the variance and generalized variance. The posterior distribution is obtained by combining the likelihood (the observed data in Phase I) and the uncertainty of the unknown parameters via the prior distribution. By using the posterior distribution the unconditional predictive density functions are derived

Die uitdagings van MIV/VIGS-opvoeding vir die 'gewone' klas- en vakonderwyser: ’n prinsipiële besinning

The challenges of HIV/AIDS education for the 'ordinary' class and subject teacher: A principial reflection HIV/AIDS has become a wide-spread epidemic. It has already claimed thousands of lives and many others are infected daily. HIV/AIDS education forms an important facet in the struggle against the disease, also in schools where ‘ordinary’ teachers (i.e. not professional AIDS practitioners) find themselves having to deal with classes of students in which learners infected by HIV or suffering from full-blown AIDS might be present. HIV/AIDS education confronts these teachers with several challenges. Feedback from an empirical survey in a province of South Africa where HIV/AIDS has assumed rampant proportions revealed that, while these ‘ordinary’ teachers were quite prepared to become involved in the struggle against HIV/AIDS, they did not see themselves as adequately equipped and prepared for the task. A number of recommendations are made to deal with this shortcoming in their training

Pyridinium diaqua­bis­(methyl­enediphospho­nato-κ2 O,O′)chromate(III) tetra­hydrate

In the title complex, (C5H6N)[Cr(CH4O6P2)2(H2O)2]·4H2O, the CrIII atom, lying on an inversion centre, is coordinated by two bidentate methyl­ene diphospho­nate ligands and two water molecules in a distorted octa­hedral coordination geometry. The pyridinium cation is located on an inversion centre, with an N atom and a C atom sharing a position each at a half occupancy. A three-dimensional network is constructed by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds between the pyridin­ium cation, complex anion and uncoordinated water mol­ecules

Long-term neuropathological and/or neurobehavioral effects of antenatal corticosteroid therapy in animal models: a systematic review

BACKGROUND: Antenatal corticosteroids (ACSs) are recommended to all women at risk for preterm delivery; currently, there is controversy about the subsequent long-term neurocognitive sequelae. This systematic review summarizes the long-term neurodevelopmental outcomes after ACS therapy in animal models. METHODS: An electronic search strategy incorporating MeSH and keywords was performed using all known literature databases and in accordance with PRISMA guidance (PROSPERO CRD42019119663). RESULTS: Of the 669 studies identified, eventually 64 were included. The majority of studies utilized dexamethasone at relative high dosages and primarily involved rodents. There was a high risk of bias, mostly due to lack of randomization, allocation concealment, and blinding. The main outcomes reported on was neuropathological, particularly glucocorticoid receptor expression and neuron densities, and neurobehavior. Overall there was an upregulation of glucocorticoid receptors with lower neuron densities and a dysregulation of the dopaminergic and serotonergic systems. This coincided with various adverse neurobehavioral outcomes. CONCLUSIONS: In animal models, ACSs consistently lead to deleterious long-term neurocognitive effects. This may be due to the specific agents, i.e., dexamethasone, or the repetitive/higher total dosing used. ACS administration varied significantly between studies and there was a high risk of bias. Future research should be standardized in well-characterized models

Bayesian testing for process capability indices

Process capability indices have been widely used in the manufacturing industry. They measure the ability of a manufacturing process to produce items that meet certain specifications. A capability index relates the voice of the customer (specification limits) to the voice of the process. There is a need to understand and interpret process capability indices. Most of the existing work in this area has been devoted to classical frequentist large sample theory. An alternative approach to the problem of making inference about capability indices is the Bayesian approach. In this paper a Bayesian version of Tukey’s method is used for constructing simultaneous credibility intervals for all pairwise differences. A Bayesian procedure for testing all possible contrasts is also given. The problem of selecting the best supplier(s) has received considerable attention in the literature, but mainly from a classical frequentist point of view. A Bayesian simulation procedure is also illustrated to find the best supplier or group of suppliers.This method seems much easier to perform than the Monte Carlo integration method given in Wu, Shiau, Pearn and Hung (2016). In section 10, a sensitivity analysis regarding the prior choice is considered and in the last section, t-distributed data are analysed

From implementation to revising simulation integration into undergraduate physiotherapy training

Background. Careful consideration of an increasingly underprepared tertiary student population, the limited use of simulation in South African (SA) healthcare education and a changing healthcare education milieu is required from SA educators when implementing, evaluating and revising simulation integration. Objectives. To develop a conceptual framework for the integration of simulation in the SA undergraduate physiotherapy programme. Methods. A non-experimental descriptive research design was used. A purposive sample of 15 healthcare educationalists from SA and abroad were approached to participate in a modified Delphi survey, informed by the results obtained from a systematic review identifying simulation integration framework elements. Data were analysed as percentages, with feedback provided to panel members following each round. Results. Data saturation was achieved after round 3, with a response rate of 73.3% (n=11). The main findings suggested that student preparation prior to simulation-based learning experiences (SBLEs) should include orientation to SBLE logistics and expectations (73%), and could include informal assessment of theory (64%). Inclusion of the feedback/debriefing process (82%), methods (100%) and timing (85%) as part of student and educator preparation were also deemed essential. Panel members agreed that programme evaluation in line with stakeholder feedback (92%) is vital for guiding adjustments to the programme that is integrating simulation. Conclusion. The developed conceptual framework indicates the necessity of student and educator preparation to ensure optimal SBLE participation and outcome achievement. Programme sustainability should be ensured through programme evaluation and adjustment, in line with stakeholder feedback, best practice and accrediting professional body guidelines

How to plan for simulation integration into undergraduate physiotherapy training

Background. The benefits of simulation in healthcare education are undeniable, and in the current healthcare climate, a drastic change in delivering healthcare training is critical. Therefore, integration of simulation is essential, and necessitates detailed planning and well-trained educators. Objectives. To develop a conceptual framework for the integration of simulation in South African (SA) undergraduate physiotherapy programmes. Methods. A non-experimental descriptive research design using a modified Delphi survey was conducted. Results from a systematic review identifying simulation integration framework elements informed the Delphi survey. A purposive sample of 15 healthcare educationalists from SA and abroad were approached to participate. Data were analysed as percentages, and feedback was provided to panel members following each round. Results. A response rate of 73.3% (n=11) was achieved. Planning was explored as one of the themes. Both institutional- and discipline-specific needs analyses were identified as essential (93%), and societal needs were useful to consider (64%). Resource identification and sharing (84%) were regarded as vital, and expert collaboration in curriculum development (79%) with scaffolded skills integration (75%) was advised. The necessity for trained facilitators (93%) and educator role identification (71%) was evident. Statements related to mastery learning/deliberate practice and the use of simulation for assessment purposes yielded the least consensus. Conclusion. A constructively aligned curriculum based on both student and institutional needs and resource availability in guiding simulation integration was regarded as essential. Educator competency in both the development and delivery of the programme, especially debriefing methods, is vital for optimising student learning

DNA amplified fingerprinting, a useful tool for determination of genetic origin and diversity analysis in Citrus

We used three short repetitive nucleotide sequences [(GTG)5, (TAC)5, and (GACA)4] either as radiolabeled probes for hybridization with restricted Citrus DNA or as single primers in polymerase chain reaction amplification experiments with total genomic DNA. We tested the ability of the sequences to discriminate between seedlings of zygotic or nuclear origin in the progeny of a Volkamer lemon #Citrus volkameriana# Ten. & Pasq.) tree. The genetic variability within two species [#Citrus sinensis# (L.) Osbeck (sweet oranges) and #Citrus reticulata# Blanco and relatives (mandarins)] was evaluated. DNA amplified figerprinting with single primers was the more successful technique for discriminating between nucellular and zygotic seedlings. Although we were not able to distinguish among 10 cultivars of #C. sinensis#, all 10 #C. reticulata# cultivars tested were distinguishable. However, it still is difficult to identify the putative parents of a hybrid plant when the two parental genomes are closely related. (Résumé d'auteur