Insulator-based dielectrophoresis of mitochondria

Isolated mitochondria display a wide range of sizes plausibly resulting from the coexistence of subpopulations, some of which may be associated with disease or aging. Strategies to separate subpopulations are needed to study the importance of these organelles in cellular functions. Here, insulator-based dielectrophoresis (iDEP) was exploited to provide a new dimension of organelle separation. The dielectrophoretic properties of isolated Fischer 344 (F344) rat semimembranosus muscle mitochondria and C57BL/6 mouse hepatic mitochondria in low conductivity buffer (0.025–0.030 S/m) at physiological pH (7.2–7.4) were studied using polydimethylsiloxane (PDMS) microfluidic devices. First, direct current (DC) and alternating current (AC) of 0–50 kHz with potentials of 0–3000 V applied over a channel length of 1 cm were separately employed to generate inhomogeneous electric fields and establish that mitochondria exhibit negative DEP (nDEP). DEP trapping potential thresholds at 0–50 kHz were also determined to be weakly dependent on applied frequency and were generally above 200 V. Second, we demonstrated a separation scheme using DC potentials <100 V to perform the first size-based iDEP sorting of mitochondria. Samples of isolated mitochondria with heterogeneous sizes (150 nm–2 μm diameters) were successfully separated into sub-micron fractions, indicating the ability to isolate mitochondria into populations based on their size.     

Relationships between functional movement screen scores,maturation and physical performance in young soccer players

The purpose of this study was to examine relationships between functional movement screen scores, maturation and physical performance in young soccer players. Thirty males (11–16 years) were assessed for maturation, functional movement screen scores and a range of physical performance tests (squat jump, reactive strength index protocol and reactive agility cut). Older players significantly outperformed younger participants in all tests (P < 0.05; effect sizes = 1.25–3.40). Deep overhead squat, in-line lunge, active straight leg raise and rotary stability test were significantly correlated to all performance tests. In-line lunge performance explained the greatest variance in reactive strength index (adjusted R² = 47%) and reactive agility cut (adjusted R² = 38%) performance, whilst maturation was the strongest predictor of squat jump performance (adjusted R² = 46%). This study demonstrated that variation of physical performance in youth soccer players could be explained by a combination of both functional movement screen scores and maturation.     

Fostering self-monitoring of university students by means of a standardized learning journal—a longitudinal study with process analyses

The self-regulation of learning behavior is an important key competence for university students. In this presented study, we aimed at fostering students’ self-regulation of learning by means of a standardized learning journal. In two of four courses that were included in the study, students had to keep a structured learning diary and/or received further intervention on self-regulated learning through a weekly course. Students who received these interventions were compared to students who received no treatment whatsoever in their self-regulation and learning achievement. The study reports pre–post measures as well as process analyses. Results revealed that keeping a structured learning diary without any further intervention did not improve students’ self-regulation. Those students who only kept learning diaries even showed a decrease in their motivation. Students who kept the learning diary and at the same time received further information on self-regulation showed increases in their strategy use and their self-efficacy. However, no improvements were found for students’ academic performance. It can be concluded that in order for students to profit in keeping a structured learning diary, they should be informed on the benefits of self-monitoring to increase their motivation.     

Developing schools as professional learning communities： The TL21 experience

Over the last 2 decades, Irish schooling and society have gone through a period of significant structural and policy-driven change. To meet the emerging needs of the knowledge/learning society, schools and teachers are challenged to develop their capacities as ＂active learning communities＂. This places greater demands on teachers and schools to reflect on their classroom practices, to utilise a wider repertoire of pedagogic styles more suited to the needs of the 21st century learners and so that meaningfully collaborate with their fellow professionals. Teaching and Learning for the 21st Century （TL21） was a 4-year （2003-2007） multi-pronged research and development project involving the Education Department at the National University of Ireland, Maynooth （NUIM） and 15 post-primary schools. The project sought to address a number of key aims in terms of developing schools as professional learning communities, including addressing the isolation and insulation which teachers can, and do experience in their day-to-day professional lives and prioritize quality in teaching and learning as a key challenge for school development planning. This paper attempts to succinctly frame the key developments and findings which emerged over the duration of this process.     

Rounding the Regression

Rounding is a necessary step in many mathematical processes. We are taught early in our education about significant figures and how to properly round a number. So when we are given a data set and asked to find a regression line, we are inclined to offer the line with rounded coefficients to reflect our model. However, the effects are not as insignificant as they might seem at first. In this paper, we investigate some consequences of rounding the coefficients in a least squares linear regression with respect to the calculated value of R², and consider ways to minimize the amount of error that can arise.     

Acute short-term sleep deprivation does not affect metacognitive monitoring captured by confidence ratings: a systematic literature review

This article presents the results of a systematic review of the literature surrounding the effects that acute sleep deprivation has on metacognitive monitoring. Metacognitive monitoring refers to the ability to accurately assess one’s own performance and state of knowledge. The mechanism behind this assessment is captured by subjective feelings of confidence concerning the accuracy of our judgments or performance. These judgments influence decision behavior. How well these subjective feelings fit with reality is critical for good decision making. For example, a driver who is overconfident in their ability to remain vigilant after a night without sleep is at risk of having an accident. A learner who is overconfident in their ability to perform well on an exam without sleep is at risk of failing. A break down in metacognitive monitoring might be responsible for the increase in poor decision making observed when people are sleep deprived. Using defined search terms and exclusion criteria, electronic database searches identified ten empirical studies suitable for review. Participants in these studies completed performance-based tasks, typically cognitive, while remaining awake for 28–63 hours. In all studies, metacognitive monitoring was assessed via confidence ratings either pre-, on-, or post-task. Extended wakefulness had a significant negative effect on performance in most studies. Evidencing good monitoring, however, the monitoring estimates such as confidence also tended to decline. Moreover, two critical variables that assess the fit of these estimates to actual performance (bias and discrimination) were mostly unaffected by the number of hours awake. Still, some results indicated that these variables may be affected by substances intended to fight sleep deprivation, such as modafinil. Within the limitations of extant literature (e.g., a sampling bias towards young adult male participants), empirical observations to date converge to suggest that metacognitive monitoring remains largely unaffected by the examined quantities of acute sleep deprivation (up to 63 hours).     

Drivers and barriers to the utilisation of gamification and game-based learning in universities: A systematic review of educators' perspectives

While gamification and game-based learning have both been demonstrated to have a host of educational benefits for university students, many university educators do not routinely use these approaches in their teaching. Therefore, this systematic review, conducted using the PRISMA guidelines, sought to identify the primary drivers and barriers to the use of gamification and game-based learning by university educators. A search of multiple databases (Web of Science, Scopus and EBSCO (Business Source Complete; ERIC; Library, Information Science & Technology Abstracts)) identified 1330 articles, with 1096 retained after duplicates were removed. Seventeen articles (11 quantitative, two mixed-methods and four qualitative) were included in the systematic review. The primary drivers described by the educators that positively influenced their gamification and game-based learning usage were their beliefs that it encourages student interactions and collaborative learning; provides fun and improves engagement; and can easily be used by students. Alternatively, the university educators' major barriers included a lack of time to develop gamification approaches, lack of proven benefits and classroom setting issues. Many of these and other less commonly reported drivers and barriers can be categorised as attitudinal, design-related or administrative in nature. Such categorisations may assist university educators, teaching support staff and administrators in better understanding the primary factors influencing the utilisation of gamification and game-based learning and develop more effective strategies to overcome these barriers to its successful implementation.

Practitioner notes

What is already known about this topic

• Gamification and game-based learning may have many benefits for university students.
• The majority of university educators do not routinely use gamification and game-based learning in their teaching.

What this paper adds

• University educators' major drivers that positively influence the use of gamification and game-based learning include their perceptions that it encourages student interactions and collaborative learning, provides fun and improves engagement and can easily be used by students.
• University educators' major barriers that negatively influence the use of gamification and game-based learning include their perceptions of a lack of time to develop gamification approaches, lack of proven benefits and classroom setting issues.
• These drivers and barriers may be classified as attitudinal, design-related and administrative, with these categories providing a useful way for universities to develop strategies to better support educators who wish to use these approaches in their teaching.

Implications for practice and policy

• Attitudinal factors such as university educators' intention to use gamification and game-based learning are influenced by a host of their perceptions including attitude, perceived usefulness and ease of use.
• A range of design-related and administrative barriers may need to be overcome to increase the use of gamification and game-based learning in the university sector.