Microfluidic platform for separation and extraction of plasma from whole blood using dielectrophoresis

Microfluidic based blood plasma extraction is a fundamental necessity that will facilitate many future lab-on-a-chip based point-of-care diagnostic systems. However, current approaches for providing this analyte are hampered by the requirement to provide external pumping or dilution of blood, which result in low effective yield, lower concentration of target constituents, and complicated functionality. This paper presents a capillary-driven, dielectrophoresis-enabled microfluidic system capable of separating and extracting cell-free plasma from small amounts of whole human blood. This process takes place directly on-chip, and without the requirement of dilution, thus eliminating the prerequisite of pre-processed blood samples and external liquid handling systems. The microfluidic chip takes advantage of a capillary pump for driving whole blood through the main channel and a cross flow filtration system for extracting plasma from whole blood. This filter is actively unblocked through negative dielectrophoresis forces, dramatically enhancing the volume of extracted plasma. Experiments using whole human blood yield volumes of around 180 nl of cell-free, undiluted plasma. We believe that implementation of various integrated biosensing techniques into this plasma extraction system could enable multiplexed detection of various biomarkers.     

Characteristics impacting on session rating of perceived exertion training load in Australian footballers

The relationship between external training load and session rating of perceived exertion (s-RPE) training load and the impact that playing experience, playing position and 2-km time-trial performance had on s-RPE training load were explored. From 39 Australian Football players, 6.9 ± 4.6 training sessions were analysed, resulting in 270 samples. Microtechnology devices provided external training load (distance, average speed, high-speed running distance, player load (PL) and player load_slow (PL_slow)). The external training load measures had moderate to very large associations (r, 95% CI) with s-RPE training load, average speed (0.45, 0.35–0.54), high-speed running distance (0.51, 0.42–0.59), PL_slow (0.80, 0.75–0.84), PL (0.86, 0.83–0.89) and distance (0.88, 0.85–0.90). Differences were described using effect sizes (d ±95% CL). When controlling for external training load, the 4- to 5-year players had higher s-RPE training load than the 0- to 1- (0.44 ± 0.33) and 2- to 3-year players (0.51 ± 0.30), ruckmen had moderately higher s-RPE training load than midfielders (0.82 ± 0.58), and there was a 0.2% increase in s-RPE training load per 1 s increase in time-trial (95% CI: 0.07–0.34). Experience, position and time-trial performance impacted the relationship between external training load and s-RPE training load. This suggests that a given external training load may result in different internal responses between athletes, potentially leaving individuals at risk of overtraining or failing to elicit positive adaptation. It is therefore vital that coaches and trainers give consideration to these mediators of s-RPE training load.     

Flights to Empire: Australia's imperial engagement with the Olympic Games, 1900–1938

Imperialism was a key concern for Australia during its early engagement with the Olympic Movement. This engagement was marked by a tension between traditional British approaches to sport and more modern approaches that could stem the tide of American superiority that had been expressed at the Olympic Games since 1896. Australia used the Olympic Games to assert its centrality within the British Empire in a sporting context. These themes are observable in three sets of circumstances: the selection of Australian teams between 1900 and 1932, Australia's engagement with the British Empire Games and Australia's response to the development of state amateurism within the Olympic Movement.     

Content-Related Interactions in Self-initiated Study Groups

The central goal of the present exploratory study was to investigate the nature of the content-related interactions in study groups independently organized by college organic chemistry students. We were particularly interested in the identification of the different factors that affected the emergence of opportunities for students to co-construct understanding and engage in higher levels of cognitive processing. Our results are based on the analysis of in situ observations of 34 self-initiated study sessions involving over a 100 students in three academic semesters. The investigation revealed three major types of social regulation processes, teaching, tutoring, and co-construction in the observed study sessions. However, the extent to which students engaged in each of them varied widely from one session to another. This variability was mostly determined by the specific composition of the study groups and the nature of the study tasks in which they were engaged. Decisions about how to organize the study session, the relative content knowledge and conceptual understanding expressed by the participants, as well as the cognitive level of the problems that guided group work had a strong impact on the nature of student interactions. Nevertheless, group talk in the observed study groups was mostly focused on low-level cognitive processes. The results of our work provide insights on how to better support students' productive engagement in study groups.     

Do you want your child to have a certified teacher?

This study examines how the teaching staff composition with respect to certification affects student achievement in compulsory Swedish schools. We apply an instrumental variable to estimate the effect of the share of non-certified teachers on student achievement (measured by grade point average, GPA). We find statistically significant negative effects on the GPA. The effect is stronger for students with highly educated parents. A one percentage point increase in the share of non-certified teachers is expected to decrease student's GPA by, on average, 1.8 standard deviations per year. This is a substantial effect considering the large differences in the shares of non-certified teachers across schools and municipalities.     

History and philosophy of science in physics education

Physics education in the Danish upper secondary school system has undergone a major reform, starting in August 1988. The earlier science‐centred physics curriculum has given way to a presentation of physics as a human activity, one way of obtaining this aim being through a compulsory introduction to elements of the history and philosophy of science. Following a brief presentation of the main reasons for including the historical‐philosophical dimension in physics teaching, this article describes how this dimension‐‐which was unfamiliar to most physics teachers‐‐was implemented in daily teaching practice. The implementation took place in three steps: (1) the development of a comprehensive teachers’ guide, (2) a nationwide in‐service teacher training programme, and (3) the publication of a number of students’ books written according to the guidelines of the committee responsible for all aspects of the implementation programme.     

Profiles of cognitive precursors to reading acquisition. Contributions to a developmental perspective of adult literacy

This article discusses conceptual and empirical elements concerning the development of cognitive processes that function as precursors of reading, and their association with the acquisition of reading skills in an adult population participating in literacy courses. It connects emergent literacy research with historical–cultural and bioecological concepts. Subsequently, it focuses on the problem of the development of profiles of cognitive reading precursors. A sample of 63 Chilean adults was studied through a growth/learning curves approach. The study replicated previous results indicating the existence of three major profiles of these cognitive precursors. Together, these precursors are associated with significantly different learning curves beyond the effect of each precursor considered separately. In addition, it established a negative association between initial phonological awareness and the rate of reading acquisition during the course. It has been claimed that an individual's participation in specific cultural activities throughout his/her life influences the development of the precursors of reading. Based on a complementary biographical study of a subsample of participants, preliminary evidence is presented that supports this link.