Fuzzy logic and Gagné learning hierarchy for assessing mathematics skills.

This study developed a fuzzy logic and Gagné learning hierarchy (FL-GLH) for assessing mathematics skills and identifying learning barrier points. Fuzzy logic was used to model the human reasoning process in linguistic terms. Specifically, fuzzy logic was used to build relationships between skill level concepts as inputs and learning achievement as an output. Gagné learning hierarchy was used to develop a learning hierarchy diagram, which included learning paths and test questions for assessing mathematics skills. First, the Gagné learning hierarchy was used to generate learning path diagrams and test questions. In the second step, skill level concepts were grouped, and their membership functions were established to fuzzify the input parameters and to build membership functions of learning achievement as an output. Third, the inference engine generated fuzzy values by applying fuzzy rules based on fuzzy reasoning. Finally, the defuzzifier converted fuzzy values to crisp output values for learning achievement. Practical applications of the FL-GLH confirmed its effectiveness for evaluating student learning achievement, for finding student learning barrier points, and for providing teachers with guidelines for improving learning efficiency in students.

Efficacy and tolerability of micronized purified flavonoid fractions (MPFF) for haemorrhoids: A systematic review and meta-analysis.

OBJECTIVE: To present a systematic review of randomised controlled trials (RCTs) examining the effects of MPFF in the management of haemorrhoid symptoms. METHODS: Electronic databases including CENTRAL, CINAHL, EMBASE, MEDLINE were searched up to April 2018 for relevant RCTs. Journal and conference proceedings were also searched. Two review authors independently selected trials, extracted data, assessed the risks of bias in included trials and graded the quality of evidence. Meta-analyses were conducted for studies presenting similar outcomes. RESULTS: Ten RCTs involving 1164 participants were included. These RCTs varied in terms of patients' grade of haemorrhoids, length of trials, and outcome assessed. Most of the studies did not describe adequately the process of randomisation and allocation concealment. The pooled analysis of data from three studies indicated that there was significant difference between groups for the bleeding outcome, favoring the MPFF group (RR 1.46; 95% CI 1.10-1.93; p = 0.008). Except for bleeding, the current evidence did not show MPFF has significant effects on all the other outcomes examined when compared with placebo. Even then, the quality of evidence for bleeding was judged as low due to the small number and inconsistent results among the included studies. CONCLUSION: This review highlights the need for further rigorous research if MPFF was to be routinely used for the treatment of haemorrhoid symptoms.

Trace levels of mitomycin C disrupt genomic integrity and lead to DNA damage response defect in long-term-cultured human embryonic stem cells.

How to maintain the genetic integrity of cultured human embryonic stem (hES) cells is raising crucial concerns for future clinical use in regenerative medicine. Mitomycin C(MMC), a DNA damage agent, is widely used for preparation of feeder cells in many laboratories. However, to what extent MMC affects the karyotypic stability of hES cells is not clear. Here, we measured residual MMC using High Performance Liquid Chromatography-Mass Spectrometry/Mass Spectrometry following each step of feeder preparation and found that 2.26 ± 0.77 and 3.50 ± 0.92 ng/ml remained in mouse feeder cells and human feeder cells, respectively. In addition, different amounts of MMC caused different chromosomal aberrations in hES cells. In particular, one abnormality, dup(1)(p32p36), was the same identical to one we previously reported in another hES cell line. Using Affymetrix SNP 6.0 arrays, the copy number variation changes of the hES cells maintained on MMC-inactivated feeders (MMC-feeder) were significantly more than those cultured on γ-inactivated feeder (IR-feeder) cells. Furthermore, DNA damage response (DDR) genes were down-regulated during long-term culture in the MMC-containing system, leading to DDR defect and shortened telomeres of hES cells, a sign of genomic instability. Therefore, MMC-feeder and MMC-induced genomic variation present an important safety problem that would limit such hES from being applied for future clinic use and drug screening.