The goal of this paper is the combined use of two theories, APOS and OSA, for the analysis of the university students' understanding on the graph of the function and its derivative. For this, we study the students' understanding to solve one graphing problem in relation to the first derivative and characterize their schemas in terms of levels (intra, inter and trans) of development of the schema for sketching ′ when given the graph . We present a multiple case study in which 14 students of the first course of Calculus in one university of Iran participated voluntarily. Results show that most of the students in our study had major problems in developing mental constructions and doing the practical work needed to solve the problem, particularly those mental constructions that have to be made to calculate the derivative at the critical points and to determine the speed of the variation of the inclination of the tangent lines to , which is why most of them have constructed a schema at the intra level of development of the schema for sketching ′ when given the graph . We finish with some final conclusions.

APOS-ACE (Action, Process, Object, and Schema-Activities, Classroom discussion, and Exercises) is applied in this article to explore the teaching and learning of derivative by giving emphasis on its graphical understanding. For this purpose, a Genetic Decomposition is developed based on the outcomes of previous studies and on our personal teaching experiences. An ACE cycle is designed with the help of the Maple software and implemented on a group of freshmen Iranian students (experimental group). The outcomes of this implementation are evaluated by comparing the performance of the experimental group to the performance of another equivalent student group (control group), to which the same subject was taught in the traditional, lecture-based way. Our findings demonstrated students' who were in the experimental group shown a better understanding of the derivate compared to the control group. Therefore, such ACE cycle with Maple could be used more frequently for teaching calculus, especially derivative.

BackgroundInadequate sleep hygiene may result in difficulties in daily functioning; therefore, reliable scales for measuring sleep hygiene are important.ObjectivesThe purpose of this study was to assess the psychometric properties of the Persian version of the Sleep Hygiene Index (SHI).Materials and MethodsFrom April 2014 to May 2015, 1280 subjects, who were selected by cluster random sampling in Kermanshah province, filled out the SHI, Pittsburgh sleep quality index (PSQI), Epworth sleepiness scale (ESS), and insomnia severity index (ISI). A subset of the participants (20%) repeated the SHI after a four to six-week interval to measure test–retest reliability. Then, we computed the Pearson product-moment correlation coefficients of SHI against PSQI, ESS and ISI, to demonstrate the construct validity of the SHI. The factor structure of the SHI was evaluated by explanatory factor analysis.ResultsThe interclass correlation coefficient was 0.89, and SHI was found to have good test–retest reliability (r = 0.89, P < 0.01). The SHI was positively correlated with the total score of the PSQI (r = 0.60, P < 0.01), ESS (r = 0.62, P < 0.01) and ISI (r = 0.60, P < 0.01). Exploratory factor analysis extracted three factors, namely “sleep–wake cycle behaviors” (four items), “bedroom factors” (three items), and “behaviors that affect sleep” (six items).ConclusionsThe Persian version of the SHI can be considered a reliable tool for evaluating sleep hygiene in the general population.

Major risk factors for diabetes, cardiovascular disorders and cancer (prostate, intestine, breast, etc.) are obesity and being overweight. This study aims to investigating the effect of neurofeedback training to food craving and mental health in overweight women. To this aim, thirty overweight women were divided into two groups; neurofeedback and control groups, using a simple random method. In this experiment, which was accompanied with pre-test and post-test with the control group, women in the experimental group received 10 sessions of neurofeedback. Both experimental and control subjects filled the food craving and general health questionnaire before and after the intervention. Univariate analysis of covariance was used for data analysis. The results showed a significant difference in food craving and mental health between the neurofeedback group and control group. The results showed that neurofeedback training can be considered as one of the complementary therapy intervention, in the field of obesity and overweight.

The main objective of this study is (a) to explore the relationship among cognitive style (field dependence/independence), working memory, and mathematics anxiety and (b) to examine their effects on students' mathematics problem solving. A sample of 161 school girls (13-14 years old) were tested on (1) the Witkin's cognitive style (Group Embedded Figure Test) and (2) Digit Span Backwards Test, with two mathematics exams. Results obtained indicate that the effect of field dependency, working memory, and mathematics anxiety on students' mathematical word problem solving was significant. Moreover, the correlation among working memory capacity, cognitive style, and students' mathematics anxiety was significant. Overall, these findings could help to provide some practical implications for adapting problem solving skills and effective teaching/learning.Keywords Field-dependent/independent Á Working memory Á Word problem Á Mathematics anxiety Students find problem solving difficult. A problem is often defined as a goal that is not immediately attainable (Hambrick and Engle 2003). Successful problem solvers spend more time analyzing a problem and should consider a wide range of alternatives. They should be open minded, flexible, and make sense of the mathematics concepts they are learning (e.g., Fernandez et al. 1994). Students approach mathematical problem solving in fundamentally different ways, particularly problems requiring conceptual understanding and complicated strategies such as word problems.Students express great difficulties in handling a word or story problem (e.g.Nickson 2004). The order of information, the relation between known and unknown, and the transition from known to unknown all influence the understanding of a story problem on younger learners (Laborde 1990;Orton 1992). As Gagne (1983) suggested, in the process of mathematical word problem solving, the student should be able to translate the concrete to the abstract, and the abstract to the concrete. It seems that the mathematical word problem exam is a more distinctive and challenging task than the ordinary mathematics task (Alamolhodaei 2002).