Extensional flow of hyaluronic acid solutions in an optimized microfluidic cross-slot device

We utilize a recently developed microfluidic device, the Optimized Shape Cross-slot Extensional Rheometer (OSCER), to study the elongational flow behavior and rheological properties of hyaluronic acid (HA) solutions representative of the synovial fluid (SF) found in the knee joint. The OSCER geometry is a stagnation point device that imposes a planar extensional flow with a homogenous extension rate over a significant length of the inlet and outlet channel axes. Due to the compressive nature of the flow generated along the inlet channels, and the planar elongational flow along the outlet channels, the flow field in the OSCER device can also be considered as representative of the flow field that arises between compressing articular cartilage layers of the knee joints during running or jumping movements. Full-field birefringence microscopy measurements demonstrate a high degree of localized macromolecular orientation along streamlines passing close to the stagnation point of the OSCER device, while micro-particle image velocimetry is used to quantify the flow kinematics. The stress-optical rule is used to assess the local extensional viscosity in the elongating fluid elements as a function of the measured deformation rate. The large limiting values of the dimensionless Trouton ratio, Tr ∼ O(50), demonstrate that these fluids are highly extensional-thickening, providing a clear mechanism for the load-dampening properties of SF. The results also indicate the potential for utilizing the OSCER in screening of physiological SF samples, which will lead to improved understanding of, and therapies for, disease progression in arthritis sufferers.     

The point of view of firms in Minas Gerais about the contribution of universities and research institutes to R&D activities

The purpose of this paper is to analyze the interactions between firms, universities and research institutes based in Minas Gerais, Brazil. The theoretical standpoint is the innovation system of developing countries. Multivariate cluster analysis is used, more specifically, the Grade of Membership method, to group firms with similar characteristics and evaluate their pattern of interaction with universities and research institutes. The main results show that the highest rates of interaction are found among firms that manufacture chemical products, cellulose, paper and paper products, followed by those engaged in the extraction of metallic and non-metallic minerals.     

A robust unscented transformation for uncertain moments

This paper proposes a robust version of the unscented transform (UT) for one-dimensional random variables. It is assumed that the moments are not exactly known, but are known to lie in intervals. In this scenario, the moment matching equations are reformulated as a system of polynomial equations and inequalities, and it is proposed to use the Chebychev center of the solution set as a robust UT. This method yields a parametrized polynomial optimization problem, which in spite of being NP-Hard, can be relaxed by some algorithms that are proposed in this paper.     

EDLE: an integrated tool to foster entrepreneurial skills development in engineering education

Academic papers on entrepreneurship in engineers’ education have been growing in the last decades. However, studies on entrepreneurship in engineering have not sought to analyze how entrepreneurship education, in connection to active learning, design thinking, and Bloom’s Taxonomy, inserted in an integrated way, as a tool, might help the process of engineering students’ entrepreneurial skills development. Thus, this study has the goal to propose an integrated tool, linked to the principles of entrepreneurship education, active learning, design thinking, and Bloom’s Taxonomy, to foster engineering students’ entrepreneurial skills development. The tool, called Entrepreneurial Dynamic Learning, is operationalized and validated in a 2-year case study in a Brazilian public university. The study also produces practical implications, and five are highlighted: (1) at the level of governments and policy makers; (2) engineering scientific associations; (3) universities, coordinators, and professors of engineering undergraduate programs; (4) engineering education researchers; and (5) the Brazilian National Confederation of Industry.     

An interrogation of the role of critical thinking in English language pedagogy in Chile

The present study aims to critically interrogate the role of Critical Thinking (CT) in English language education in Chile through the analysis of teacher educators’ and postgraduate students’ perceptions and understandings of CT in relation to their academic trajectories through university. Five postgraduate students and five teacher educators from three different Masters of Teaching English as a Foreign Language (MTEFL) programs agreed to take part in the research. Informed by a qualitative paradigm, semi-structured interviews were conducted aimed mainly at (1) unpacking teacher educators’ and postgraduate students’ understandings of CT; (2) investigating postgraduates’ views of the place of critical thinking in their English teacher education training; (3) examining the ways in which teacher educators deal with CT in their pedagogies; and (4) identifying students’ preparedness to approach reading and writing critically, as viewed by both groups of participants. Analysis of responses revealed, on the one hand, students’ recognition of CT skills as necessary to succeed in academic life and, on the other, great concerns for the limited importance accorded to teaching these skills in teacher education courses. Teacher educators’ responses generally showed an increasing interest in trying to incorporate the teaching of CT skills in their pedagogies, but admitted to an overall lack of consistency in the implementation process. The paper concludes with critical questions about the perceived pedagogical mismatches between teacher educators’ and postgraduate students’ perceptions of the role of CT in their academic journeys, and about the role of Chilean teacher education programs in addressing these issues.     

Teacher perceived difficulty in implementing differentiated instructional strategies in primary school

This study analyses teacher perceived difficulty in implementing differentiated instructional strategies in regular classes. The participants were 273 Portuguese primary school teachers with teaching experience ranging from 1 to 33 years. A 39-item questionnaire was used to evaluate teacher perceived difficulty in relation to different instructional strategies. Teacher responses were factor analysed and five different domains were identified: (1) activities and materials; (2) assessment; (3) management; (4) planning and preparation; and (5) classroom environment. Results showed that with the exception of the classroom environment domain, all the instruction practices in the remaining domains were considered to be difficult. In particular, the most difficult practices were under the domain of activities and materials and were associated with the adaptation of curricular elements (content, process, and product) based on student characteristics (readiness, interest, and learning profiles). The results also revealed a strong association between the activities and materials domain and the assessment domain. Some implications of these findings for initial teacher training and teacher professional development programmes are discussed.     

Biomechanics,energetics and coordination during extreme swimming intensity: effect of performance level

The present study aimed to examine how high- and low-speed swimmers organise biomechanical, energetic and coordinative factors throughout extreme intensity swim. Sixteen swimmers (eight high- and eight low-speed) performed, in free condition, 100-m front crawl at maximal intensity and 25, 50 and 75-m bouts (at same pace as the previous 100-m), and 100-m maximal front crawl on the measuring active drag system (MAD-system). A 3D dual-media optoelectronic system was used to assess speed, stroke frequency, stroke length, propelling efficiency and index of coordination (IdC), with power assessed by MAD-system and energy cost by quantifying oxygen consumption plus blood lactate. Both groups presented a similar profile in speed, power output, stroke frequency, stroke length, propelling efficiency and energy cost along the effort, while a distinct coordination profile was observed (F_{(3, 42)} = 3.59, P = 0.04). Speed, power, stroke frequency and propelling efficiency (not significant, only a tendency) were higher in high-speed swimmers, while stroke length and energy cost were similar between groups. Performing at extreme intensity led better level swimmers to achieve superior speed due to higher power and propelling efficiency, with consequent ability to swim at higher stroke frequencies. This imposes specific constraints, resulting in a distinct IdC magnitude and profile between groups.     

William Peter Robinson: 1933–2021

European Journal of Psychology of Education -