Taiwanese Junior High School Students’ Understanding about the Validity of Conditional Statements

This research was designed to study Taiwanese junior high school students understanding about the validity of conditional statements. Distinguishing between validity and truth is a crucial topic in mathematical reasoning and argumentation but has been always neglected in the mathematics curriculum at junior high school level of schooling. The aims of the survey were (1) to find out the methods Taiwanese junior high school students used when conducting mathematical justification on conditional statements; (2) to examine whether the students could distinguish between a statement and its converse statement; (3) to analyse whether the correctness of a conditional statement influenced the students to conduct mathematical reasoning and argumentation. Approaching the three aims of the survey is expected to give some insights into the issue of whether the students could distinguish between the validity of conditional statements and the truth of assertions. Several thousand students from different schools which were randomly sampled from within six geographically diverse (regions of Taiwan) were administered a test on either algebra/number-pattern or geometry corresponding to their respective grades. The main results were (1) the methods the students used when conducting mathematical justifications on conditional statements were called producing (supporting- or counter-) example(s), analytical narrative, and analytical formal; (2) over a third of those students, who considered the given conditional statement to be valid or invalid, proposed supporting- or counter-example(s), respectively; (3) over half the students considered the statement and its converse to be the same; (4) students reasoning performance was influenced by their opinions of the correctness of the conditional statements. These results seem to lead to the conclusion that most of these students could not distinguish between the validity of conditional statements and the truth of assertions.     

Students’ Perception of Interdisciplinary,Problem‐Based Learning in a Food Biotechnology Course

Abstract: Students’ perception of 8 criteria (rationale of the problem; interdisciplinary learning; facilitator asked essential questions; learner's skills; assessments; facilitation procedures; team's use of resources [team collaboration], and facilitator within a problem‐based learning context) were assessed for a food biotechnology course that was part of a 3rd year biotechnology program. The mean score for “perceived learner's skills” was the lowest whereas those for “facilitation” and “facilitator” were the highest. Selected qualitative comments from students were also analyzed. This study demonstrated interdisciplinary learning as the students could make meaningful connections across different science disciplines. Further investigation is needed to develop possible strategies to accommodate the challenges in making meaningful connections across science disciplines as well as to develop a defined hybrid method for analysis of students’ responses.     

The phonological awareness relation to early reading in English for three groups of simultaneous bilingual children

Reading and Writing - Phonological awareness is critical for early reading acquisition across alphabetic as well as non-alphabetic languages. The grain size of phonological awareness varies with...     

Limit cycle analysis of nonlinear sampled-data systems by gain-phase margin approach

This work analyzes the limit cycle phenomena of nonlinear sampled-data systems by applying the methods of gain-phase margin testing, the M-locus and the parameter plane. First, a sampled-data control system with nonlinear elements is linearized by the classical method of describing functions. The stability of the equivalent linearized system is then analyzed using the stability equations and the parameter plane method, with adjustable parameters. After the gain-phase margin tester has been added to the forward open-loop system, exactly how the gain-phase margin and the characteristics of the limit cycle are related can be elicited by determining the intersections of the M-locus and the constant gain and phase boundaries. A concise method is presented to solve this problem. The minimum gain-phase margin of the nonlinear sampled-data system at which a limit cycle can occur is investigated. This work indicates that the procedure can be easily extended to analyze the limit cycles of a sampled-data system from a continuous-data system cases considered in the literature. Finally, a sampled-data system with multiple nonlinearities is illustrated to verify the validity of the procedure.     

Health benefits of Kung Fu: a systematic review

The Chinese martial arts (Kung Fu) have existed for centuries and are generally accepted as being beneficial for health without much empirical data. The aim of this systematic review was to assess the health effects of "hard" Kung Fu styles by performing electronic and manual searches of the literature. The aspects of health and the Kung Fu style examined varied between most studies; in some cases, the martial art group consisted of practitioners of other martial art styles also. Of 2103 references identified, only nine papers were eligible and reviewed. All were observational studies, observing a range of health aspects possibly related to Kung Fu training or performance. Our findings suggest that there is no evidence that Kung Fu practice is associated with the prevention or treatment of any health condition. However, as a moderate- to high-intensity form of aerobic exercise, it may confer benefits similar to those attributed to other aerobic training modalities. However, this hypothesis remains to be tested in clinical trials. Physiological benefits (e.g., aerobic capacity and bone density) may be associated with long-term Kung Fu practice. Future research in this area should adopt experimental designs, clearly identifying eligibility criteria, testing and training protocols, and include health-related outcomes and documentation of adverse events, to advance knowledge in this field.     

Determinants of recovery from a 161-km ultramarathon

The primary study objective was to identify determinants of short-term recovery from a 161-km ultramarathon. Participants completed 400 m runs at maximum speed before the race and on days 3 and 5 post-race, provided a post-race blood sample for plasma creatine kinase (CK) concentration, and provided lower body muscle pain and soreness ratings (soreness, 10-point scale) and overall muscular fatigue scores (fatigue, 100-point scale) pre-race and for 7 days post-race. Among 72 race finishers, soreness and fatigue had statistically returned to pre-race levels by 5 days post-race; and 400 m times at days 3 and 5 remained 26% (P = 0.001) and 12% (P = 0.01) slower compared with pre-race, respectively. CK best modelled soreness, fatigue and per cent change in post-race 400 m time. Runners with the highest CKs had 1.5 points higher (P < 0.001) soreness and 11.2 points higher (P = 0.006) fatigue than runners with the lowest CKs. For the model of 400 m time, a significant interaction of time with CK (P < 0.001) indicates that higher CKs were linked with a slower rate of return to pre-race 400 m time. Since post-race CK was the main modifiable determinant of recovery following the ultramarathon, appropriate training appears to be the optimal approach to enhance ultramarathon recovery.     

Shaping selection environments for industrial catch-up and sustainability transitions: A systemic perspective on endogenizing windows of opportunity

Transitioning economic sectors towards more sustainable futures is a major global challenge, in particular for non-OECD countries. Policymakers in these countries are confronted with a double challenge: how to implement cleaner technologies and infrastructures while at the same time promoting rapid industrial development. In catch-up studies, this trade-off has been increasingly interpreted as providing windows of opportunity for gaining strong leadership in new generations of cleantech industries. In this paper, we maintain that in order to specify how these windows of opportunity can be endogenized, a deeper understanding is needed about whether, how and by whom the directionality of innovation systems can be influenced. For this purpose, we propose an analytical approach that draws on the technological innovation system framework extending the current understanding of directionality in two ways: first, we complement the prevalent top-down perspective with a bottom-up view exemplified by the institutional entrepreneurship literature. Second, we posit that the focus has to be shifted from the manufacturing of single technologies to the transformation of entire socio-technical systems. The presented framework is validated by a case study on recent shifts in the dominant technology in China’s urban water management sector. Major changes in the country’s sectoral selection environment led membrane bioreactor technology to become the dominant design in urban water management – a development that is unmatched in any other country in the world. Owing to these transformations, China’s technology firms outcompete multinational players and therefore they show strong potentials for industrial leapfrogging. However, although the promise to solve environmental problems played a decisive role in the shaping of the selection environment, it remains unclear whether the observed transformation leads the way to a more sustainable sector structure in the longer run. The case, however, still enables us to specify how windows of opportunity can be endogenized through the interplay of different actors trying to shape different layers of the selection environment in a specific sector.     

Preparing students for future learning with Teachable Agents

One valuable goal of instructional technologies in K-12 education is to prepare students for future learning. Two classroom studies examined whether Teachable Agents (TA) achieves this goal. TA is an instructional technology that draws on the social metaphor of teaching a computer agent to help students learn. Students teach their agent by creating concept maps. Artificial intelligence enables TA to use the concept maps to answer questions, thereby providing interactivity, a model of thinking, and feedback. Elementary schoolchildren learning science with TA exhibited “added-value” learning that did not adversely affect the “basic-value” they gained from their regular curriculum, despite trade-offs in instructional time. Moreover, TA prepared students to learn new science content from their regular lessons, even when they were no longer using the software.     

A microfluidics approach towards high-throughput pathogen removal from blood using margination

Sepsis is an adverse systemic inflammatory response caused by microbial infection in blood. This paper reports a simple microfluidic approach for intrinsic, non-specific removal of both microbes and inflammatory cellular components (platelets and leukocytes) from whole blood, inspired by the invivo phenomenon of leukocyte margination. As blood flows through a narrow microchannel (20 × 20 µm), deformable red blood cells (RBCs) migrate axially to the channel centre, resulting in margination of other cell types (bacteria, platelets, and leukocytes) towards the channel sides. By using a simple cascaded channel design, the blood samples undergo a 2-stage bacteria removal in a single pass through the device, thereby allowing higher bacterial removal efficiency. As an application for sepsis treatment, we demonstrated separation of Escherichia coli and Saccharomyces cerevisiae spiked into whole blood, achieving high removal efficiencies of ∼80% and ∼90%, respectively. Inflammatory cellular components were also depleted by >80% in the filtered blood samples which could help to modulate the host inflammatory response and potentially serve as a blood cleansing method for sepsis treatment. The developed technique offers significant advantages including high throughput (∼1 ml/h per channel) and label-free separation which allows non-specific removal of any blood-borne pathogens (bacteria and fungi). The continuous processing and collection mode could potentially enable the return of filtered blood back to the patient directly, similar to a simple and complete dialysis circuit setup. Lastly, we designed and tested a larger filtration device consisting of 6 channels in parallel (∼6 ml/h) and obtained similar filtration performances. Further multiplexing is possible by increasing channel parallelization or device stacking to achieve higher throughput comparable to convectional blood dialysis systems used in clinical settings.