An Adaptive Design for Item Parameter Online Estimation and Q-Matrix Online Calibration in CD-CAT

The implementation of cognitive diagnostic computerized adaptive testing often depends on a high-quality item bank. How to online estimate the item parameters and calibrate the Q-matrix required by items becomes an important problem in the construction of the high-quality item bank for personalized adaptive learning. The related previous research mainly focused on the calibration method with the random design in which the new items were randomly assigned to examinees. Although the way of randomly assigning new items can ensure the randomness of data sampling, some examinees cannot provide enough information about item parameter estimation or Q-matrix calibration for the new items. In order to increase design efficiency, we investigated three adaptive designs under different practical situations: (a) because the non-parametric classification method needs calibrated item attribute vectors, but not item parameters, the first study focused on an optimal design for the calibration of the Q-matrix of the new items based on Shannon entropy; (b) if the Q-matrix of the new items was specified by subject experts, an optimal design was designed for the estimation of item parameters based on Fisher information; and (c) if the Q-matrix and item parameters are unknown for the new items, we developed a hybrid optimal design for simultaneously estimating them. The simulation results showed that, the adaptive designs are better than the random design with a limited number of examinees in terms of the correct recovery rate of attribute vectors and the precision of item parameters.

A Salute to PVT TIM HiLL: Indispensable amino acids and global human health

Students are taught the study mnemonic PVT TIM HiLL to memorize nineindispensable amino acids (IAA); Phenylalanine, Valine, Threonine, Tryptophan,Isoleucine, Methionine, Histidine, Leucine, and Lysine.  The Food and Animal Organization (FAO)recommended IAA be treated as individual nutrients on food labels because‘crude protein’ alone does not indicate protein quality.  Protein quality, determined by digestible IAAscore (DIAAS) is calculated for three life stages; birth to 6 months; 6 monthsto 3 years, and 3 years and older.  Foodspossessing DIAAS greater than 100 are “excellent” protein quality, DIAASbetween 75 and 99 are ‘good’, while foods with DIAAS < 75 cannot make aprotein claim.  Processing, heating,and(or) grinding can decrease or improve plant and animal IAA digestibility.For children six months to three years, ground pork, smoked-cooked bacon,cooked pork leg, cured ham, cooked pork loin, salami, beef/pork bologna, beefjerky, and medium and medium rare beef ribeye steaks can be described‘excellent’.  Cooked ground beef can beclassified as ‘good’ or ‘excellent’ depending on the study, while theImpossible and Beyond meat-alternative burgers and well-done ribeye can beclassified as ‘good’ sources of IAA for young children.  For persons > 3 years, all meat categoriesbut cooked ground beef can be classified ‘excellent’ sources of IAA.  For meat alternatives, Impossible Burger®could be classified as ‘excellent’ but Beyond Burger® could only claim to be‘good’.  Protein quality claims forindividual food ingredients can be diminished when consumed with a lowerprotein quality item such as a wheat flour bun. To provide meals that are adequate in all IAA, the protein quality ineach food item must be determined.  Mixedmeals must be adjusted for protein quality by combining low quality proteins(present in cereals and grains) with higher quality proteins (present in foodsof animal origin).

Association between splenectomy and chronic thromboembolic pulmonary hypertension: a systematic review and meta-analysis

ObjectiveWhether splenectomy increases the risk of chronic thromboembolic pulmonary hypertension (CTEPH) remains unclear. We conducted a systematic review and meta-analysis to explore the association between splenectomy and CTEPH.DesignSystematic review and meta-analysis.Data sourcesPubMed, Embase and Cochrane Library databases.MethodsTwo authors independently searched and extracted the data. The Newcastle-Ottawa Scale and the Strengthening the Reporting of Observational Studies in Epidemiology guidelines were used to assess the quality of the included studies, and each quality item was graded as low risk or high risk. A random-effects model was used to calculate different effective values.ResultsIn total, 8 trials involving 6183 participants fulfilled the inclusion criteria. The overall pooled crude prevalence of splenectomy was 4.0% (95% CI 0.03 to 0.06, I2=71.5%, p<0.001) in patients with CTEPH. Subgroup analysis showed a statistically significant high incidence of splenectomy in patients with CTEPH (OR=2.94, 95% CI 1.62 to 5.33, I2=0.0%, p<0.001) compared with patients with pulmonary arterial hypertension. There was a significantly high incidence of splenectomy in patients with CTEPH (OR=5.59, 95% CI 2.12 to 14.74, I2=0.0%, p<0.001) compared with patients with thromboembolism disease (venous thromboembolism or pulmonary embolism).ConclusionThe prevalence of splenectomy in patients with CTEPH was 4.0% and CTEPH might be associated with splenectomy. However, high-quality prospective trials are needed.PROSPERO registration numberCRD42020137591.

Improved Quality: Item and Test parameters

Introduction: Quality of a MCQ type test depends on qualities of the constituent items, assessed in terms of item reliability, item difficulty value, item discriminating value, etc. However, quality of a test involving reliability, validity, difficulty and discriminating values of the test etc. requires new approaches. Need is felt to find difficulty and discriminating values of an item and test using entire data and to derive relationships amongst them including relationship with test reliability to see impact of item deletion. Methods: Using angular similarity approach, measures proposed for item difficulty and item discriminating value, difficulty and discriminating value of test. Relationship derived between (i) difficulty value and discriminating value of item; (ii) difficulty value and discriminating value of a test (iii) test discriminating value and test reliability as per theoretical definition. Cronbach alpha was expressed using sum of item difficulty values and test discriminating value Results and Discussion: Each proposed measure ranges between 0 to 1. Discriminating value of test and item as coefficient of variation satisfy desired properties and facilitates population estimations. Intersection of item difficulty and item discriminating curves provides a data driven criterion for item deletion, impact of which on test reliability may be checked. In addition, the proposed measures facilitate testing of statistical hypothesis of departure of test reliability from unity, confidence interval of reliability, etc. Future problems suggested.

Sludge Production Characteristics of SedimentationㆍDissolved Air Flotation (SeDAF) Process for Enhanced Phosphorus Removal

Objectives : In order to prevent eutrophication and algal blooms, Ministry of Environment in Korea reinforced the effluent standards of wastewater treatment facilities. As a result, many advanced wastewater treatment processes have been implemented nationwide. Current conventional treatment systems have usually been facing high operational costs and large sludge production problems. Therefore, it is essential to develop more economic and efficient process to cope with these issues.Methods : The sedimentation and dissolved air flotation (SeDAF) process has been developed, that integrates sedimentation and dissolved air flotation. Several simulation experiments were carried out to verify and optimize the operation conditions of the SeDAF process. Removal efficiencies of each water quality item and sludge mass balance were analyzed intensively in the SeDAF process using the modified jar-test.Results and Discussion : Removal efficiencies of the SeDAF process were higher and more stable than those of sedimentation process. Several ‘sludge production / coagulant dosage’ ratios were analyzed and the representative value of 4 mg･L-1 as SS / mg･L-1 as Al₂O₃ was obtained in the SeDAF process. Fractions of suspended solids (SS) and total phosphorus (T-P) in sludge were measured; the ratios of flotation sludge to sedimentation sludge and fractions of flotation sludge in total sludge had their typical convergence ranges for the conditions of optimal coagulant dosage.Conclusions : The ratios or fractions of SS and T-P in sludge could be applied as the evaluation indicators of the SeDAF process. The reduction of coagulant dosage could be corresponded directly to the reduction of sludge production.

Manufacturing and selling tactics for a green supply chain under a green cost sharing and a refund agreement

Purpose This paper aims to deal with optimal pricing and production tactics for a bi-echelon green supply chain, including a producer and a vendor in presence of three various scenarios. Demand depends on a price, refund and quality where the producer controls quality and the vendor proposes a refund policy to purchasers to encourage them to order more. Design/methodology/approach In the first scenario, the members seek to optimize their optimum decision variables under a centralized decision-making method while in the second scenario, a decentralized system is assumed where the members make a decision about variables and profits under a non-cooperative game. In the third scenario, a cost-sharing agreement is concluded between the members to provide a high-quality item to the purchasers. Findings The performance of the proposed model is investigated by illustrating a numerical example. A sensitivity analysis of some key parameters has been done to study the effect of the changes on the optimal values of the decision variables and profits. From sensitivity analysis, the real features are observed and mentioned in this section. Originality/value This research examines the behavior of partners in a green supply chain facing with a group of purchasers whose demand is the function of a price, greenery degree and refund rate. This proposed mathematical model is developed and analyzed which has an implication in supply chain model.

Improvement of Faculty’s Skills on the Creation of Items for Progress Testing Through Feedback to Item Writers: a Successful Experience

The evaluation of knowledge is an important step in the teachers’ work, because it is fundamental that the evaluation results be valid and reliable. Several faculty development programs have been undertaken to improve teachers’ skills on item writing. Few studies, however, have explored the benefits of providing feedback to multiple-choice item writers. Progress Testing is a longitudinal assessment of students’ knowledge gain. Their results are useful for generating feedback to students, teachers and medical school managers. The aim of this report is to present a successful experience of faculty development on high-quality item writing for Progress Testing through feedback about the fate of the items written by faculty members. Annually, faculties from medical schools participating in a consortium for the application of the Progress Test are asked to formulate new items to compose the test version. However, the fate of the items is not known by their authors, that is, they do not know if the items are incorporated into the test, if the items have good quality, what is the students’ performance in each of the items, and what is the psychometric function of the items. In 2017, one of the schools participating in the consortium offered its item authors a feedback regarding the flaws in item writing, modification of items by the review committee and students’ performance, as well as psychometric function in each item. The percentage of flawed item (items without enough quality to be selected for the test) was more than 30%. There was an inverse relation between the number of flawed item and the number of items included in the final exam, when analyzing the different content areas of the test (that is, Internal Medicine, Surgery, Pediatrics, Obstetrics and Gynecology, Public Health, and Basic Sciences). In the following year, we observed a decrease in the number of flawed item (less than 10%) and an increase in the number of eligible items to be selected for the Progress Testing. Therefore, giving feedback to item writers seems to be a good strategy for developing the faculty’s ability on writing good quality items.

Accessing DMPA-SC through the public and private sectors in Nigeria: users’ characteristics and their experiences

Background: Beginning in 2015, subcutaneous depot medroxyprogesterone acetate (DMPA-SC) was added to the contraceptive method mix in Nigeria, primarily through social marketing in the private sector and community-based distribution in the public sector. We compare user experiences in acquiring DMPA-SC across sectors during this national scale-up. Methods: From October 2017 to February 2018, 459 women (Npublic=235; Nprivate=224) completed a phone survey from a convenience sample of 1,444 women (Npublic=912; Nprivate=532) who obtained DMPA-SC from participating providers and agreed to be contacted. We examined the sociodemographic predictors of attending a public vs. private provider and analyzed differences in care-seeking across sectors (becoming aware of DMPA-SC, choosing a provider, choosing DMPA-SC, quality of care). Results: Respondents obtaining DMPA-SC from public providers were younger and less educated than those attending private providers. Both program respondents were comprised of similar percentages of new users of modern contraception (58.7-60.3%), although most respondents became aware of DMPA-SC through a friend/family member (43.1%) or a provider (41.5%). Relatively more public sector respondents also heard about DMPA-SC through community outreaches whereas relatively more private sector respondents became aware through media. Convenience was the most common reason for choosing a provider—43.8% among all respondents (higher among public sector respondents). Private sector respondents were also more likely to choose a past or usual provider. Having overall higher quality interactions were more likely among clients who attended private providers than public providers, but responses to individual quality item measures show specific areas of poor quality for providers in each sector. Conclusions: Training emphasizing technical thoroughness, sensitivity toward younger women, and client choice may help improve women’s experiences with obtaining DMPA-SC, ultimately contributing to accelerating demand for and uptake of DMPA-SC specifically and contraception in general.