Drainage after total thyroidectomy or lobectomy for benign thyroidal disorders

Objective: This prospective randomized clinical trial was conducted to evaluate the necessity of drainage after total thyroidectomy or lobectomy for benign thyroidal disorders. Methods: A total of 116 patients who underwent total thyroidectomy or lobectomy for benign thyroidal disorders were randomly allocated to be drained or not. Operative and postoperative outcomes including operating time, postoperative pain assessed by visual analogue scale (VAS), total amount of intramuscular analgesic administration, hospital stay, complications, necessity for re-operation and satisfaction of patients were all assessed. Results: The mean operating time was similar between two groups (the drained and non-drained groups). The mean VAS score was found to be significantly low in the non-drained group patients in postoperative day (POD) 0 and POD 1. The mean amount of intramuscular analgesic requirement was significantly less in the non-drained group. One case of hematoma, two cases of seroma and three cases of transient hypoparathyroidism occurred in the non-drained group, whereas one case of hematoma, two cases of seroma, two cases of wound infections and two cases of transient hypoparathyroidism occurred in the drained group. No patient needed re-operation for any complication. The mean hospital stay was significantly shorter and the satisfaction of patients was superior in the non-drained group. Conclusion: These findings suggest that postoperative complications cannot be prevented by using drains after total thyroidectomy or lobectomy for benign thyroid disorders. Furthermore, the use of drains may increase postoperative pain and the analgesic requirement, and prolong the hospital stay. In the light of these findings, the routine use of drains might not be necessary after thyroid surgery for benign disorders.     

Examining the Effects of Problem‐solving Training on the Acquisition of Interpersonal Problem‐solving Skills by 5‐Year‐old Children in Turkey

This study was designed and carried out to examine the effect of problem‐solving training on the acquisition of interpersonal problem‐solving skills by 5 year‐old children. The subjects consisted of 74 5 year‐olds (34 girls and 40 boys) attending a kindergarten in Ankara, Turkey. Of these children 38 were assigned to the experimental group and 36 to the control group. The procedure consisted of pre‐testing, training and post‐testing activities. The training phase involved a programme of activities that required working with children for a certain period of time every day for 14 weeks. In the statistical analysis of the data collected ‘Chi‐Square (x²) test for significance’ was used for the evaluation of the differences between the experimental and control groups. The results were also evaluated on the basis of ‘the significance test for the difference between two means’. This was used to study the relationship between variables. The results showed that problem‐solving training was effective in helping 5 year‐old kindergarten children acquire interpersonal problem‐solving skills.     

Static Versus Dynamic Disposition: The Role of GeoGebra in Representing Polynomial-Rational Inequalities and Exponential-Logarithmic Functions

This study investigates prospective secondary mathematics teachers’ visual representations of polynomial and rational inequalities, and graphs of exponential and logarithmic functions with GeoGebra Dynamic Software. Five prospective teachers in a university in the United States participated in this research study, which was situated within a framework of productive disposition and visual representations in pre-calculus. The main result was that the role of GeoGebra as a cognitive tool fostered the research participants’ productive disposition, despite recurrent mismatches between the algebraic and visualized formalisms. Moreover, participants exhibiting dynamic productive disposition seemed to understand and make better sense of the conceptual underpinnings of the mathematical content they explored in contrast to those embracing static productive disposition.     

The change of planned happenstance skills and its association with career-related variables during school-to-work transition

The current study examined how planned happenstance skills (i.e., curiosity, flexibility, persistence, optimism, and risk-taking) changed during school-to-work transition and how career-related variables were associated with the initial levels and change rates of planned happenstance skills. In a sample of 307 South Korean college students, all planned happenstance skills except for risk-taking decreased over time. Furthermore, some of the career-related variables were associated with the initial level and the change rates of planned happenstance skills. In sum, the current study suggests that utilizing planned happenstance skills may be a worthwhile pursuit during school-to-work transition.     

Perceptions of peer-led learning among older adults in a community-based aquatic exercise program

While aquatic exercises have been considered one of the most appropriate learning activities for older adult learners because they are safe and beneficial for health, limited evidence exists regarding how older adult learners perceive their learning environment and different learning strategies. Thus, our research explored older adults’ perceptions of peer-led aquatics classes. We interviewed 19 individuals who participated in aquatics exercise courses in a community recreation center in order to answer the following research questions: (a) How do older adults perceive a peer-led aquatics class? (b) How do older adult learners describe their interaction with their instructor and other learners in their learning environment? Using constant comparative analysis, we identified the participants’ perceptions of peer-led learning with regard to their perceived relationships in class, optimistic views on the peer-led learning concept, mixed and neutral attitudes, and professionalism of teaching. From our findings, we discussed empathic relationships, mixed perspectives derived from learners’ physical condition and personal value, and a lack of peer instructor training programs, especially in a senior fitness field. Findings have implications for senior fitness instructors and educators of older adults.     

Ionosphere and radio communication

The Earth’s ionosphere consists of plasma produced by the photoionization of thin upper atmospheric gases by UV rays and photons of short wavelength from the sun. The upper ionosphere is used for radio communication and navigation as it re-ects long, medium, as well as short radio waves. Since solar radiation is the main cause of the existence of ionosphere, any variation in the radiations can affect the entire radio communication system. This article attempts to brie-y introduce the readers to the study of ionosphere in the context of its use as a radio re-ector, with particular reference to India.     

Linear Algebra Students' Understanding of Similar Matrices and Matrix Representations of Linear Transformations in a MATLAB-Assisted Learning Environment

Abstract

The purpose of this research study was to understand how mathematics majors make sense of similar matrices, a linear algebra topic that is rich in internal and external connections, in a series of in-depth qualitative interviews in a technology-assisted (MATLAB) learning environment. The study was also an attempt to develop a cognitive theory in mathematics majors’ treatment of similar matrices and matrix representations of linear transformations in a computer-assisted learning environment by drawing primarily on three aspects of the experimental mathematics methodology, made possible by using modern digital tools to enhance learning: testing conjectures, suggesting proofs, and, computing lengthy hand derivations (Borwein &; Bailey, 2003 Borwein, J. M., &; Bailey, D. H. (2003). Experiments in mathematics: Computational paths to discovery. Natick, MA: AK Peters. [Google Scholar]). The analysis revealed a diversity of innovative ways by which research participants coordinated analytic and computational (MATLAB) methods for understanding matrix similarity and its connections to the rest of linear algebra. The paper concludes by offering pedagogical implications and recommendations for further research.     

Prospective mathematics teachers’ sense making of polynomial multiplication and factorization modeled with algebra tiles

This study is about prospective secondary mathematics teachers’ understanding and sense making of representational quantities generated by algebra tiles, the quantitative units (linear vs. areal) inherent in the nature of these quantities, and the quantitative addition and multiplication operations—referent preserving versus referent transforming compositions—acting on these quantities. Although multiplicative structures can be modeled by additive structures, they have their own characteristics inherent in their nature. I situate my analysis within a framework of unit coordination with different levels of units supported by a theory of quantitative reasoning and theorems-in-action. Data consist of videotaped qualitative interviews during which prospective mathematics teachers were asked problems on multiplication and factorization of polynomial expressions in x and y. I generated a thematic analysis by undertaking a retrospective analysis, using constant comparison methodology. There was a pattern which showed itself in all my findings. Two student–teachers constantly relied on an additive interpretation of the context, whereas three others were able to distinguish between and when to rely on an additive or a multiplicative interpretation of the context. My results indicate that the identification and coordination of the representational quantities and their units at different categories (multiplicative, additive, pseudo-multiplicative) are critical aspects of quantitative reasoning and need to be emphasized in the teaching–learning process. Moreover, representational Cartesian products-in-action at two different levels, indicators of multiplicative thinking, were available to two research participants only.