Using compositional data analysis to explore accumulation of sedentary behavior,physical activity and youth health

Purpose:The study aimed to describe youth time-use compositions,focusing on time spent in shorter and longer bouts of sedentary behavior and physical activity(PA),and to examine associations of these time-use compositions with cardiometabolic biomarkers.Methods:Accelerometer and cardiometabolic biomarker data from 2 Australian studies involving youths 7-13 years old were pooled(complete cases with accelerometry and adiposity marker data,n=782).A 9-component time-use composition was formed using compositional data analysis:time in shorter and longer bouts of sedentary behavior;time in shorter and longer bouts of light-,moderate-,or vigorous-intensity PA;and"other time"(i.e.,non-wear/sleep).Shorter and longer bouts of sedentary time were defined as<5 min and>5 min,respectively.Shorter bouts of light-,moderate-,and vigorous-intensity PA were defined as<1 min;longer bouts were defined as≥1 min.Regression models examined associations between overall time-use composition and cardiometabolic biomarkers.Then,associations were derived between ratios of longer activity patterns relative to shorter activity patterns,and of each intensity level relative to the other intensity levels and"other time",and cardiometabolic biomarkers.Results:Confounder-adjusted models showed that the overall time-use composition was associated with adiposity,blood pressure,lipids,and the summary score.Specifically,more time in longer bouts of light-intensity PA relative to shorter bouts of light-intensity PA was significantly associated with greater body mass index z-score(zBMI)(β=1.79;SE=0.68)and waist circumference(β=18.35,SE=4.78).When each activity intensity was considered relative to all higher intensities and"other time",more time in light-and vigorous-intensity PA,and less time in sedentary behavior and moderate-intensity PA,were associated with lower waist circumference.Conclusion:Accumulating PA,particularly light-intensity PA,in frequent short bursts may be more beneficial for limiting adiposity compared to accumulating the same amount of PA at these intensities in longer bouts.     

High-throughput study of alpha-synuclein expression in yeast using microfluidics for control of local cellular microenvironment

Microfluidics is an emerging technology which allows the miniaturization, integration, and automation of fluid handling processes. Microfluidic systems offer low sample consumption, significantly reduced processing time, and the prospect of massive parallelization. A microfluidic platform was developed for the control of the soluble cellular microenvironment of Saccharomyces cerevisiae cells, which enabled high-throughput monitoring of the controlled expression of alpha-synuclein (aSyn), a protein involved in Parkinson's disease. Y-shaped structures were fabricated using particle desorption mass spectrometry-based soft-lithography techniques to generate biomolecular gradients along a microchannel. Cell traps integrated along the microchannel allowed the positioning and monitoring of cells in precise locations, where different, well-controlled chemical environments were established. S. cerevisiae cells genetically engineered to encode the fusion protein aSyn-GFP (green fluorescent protein) under the control of GAL1, a galactose inducible promoter, were loaded in the microfluidic structure. A galactose concentration gradient was established in the channel and a time-dependent aSyn-GFP expression was obtained as a function of the positioning of cells along the galactose gradient. Our results demonstrate the applicability of this microfluidic platform to the spatiotemporal control of cellular microenvironment and open a range of possibilities for the study of cellular processes based on single-cell analysis.     

Interpersonal dynamics and relative positioning to scoring target of performers in 1 vs. 1 sub-phases of team sports

Abstract In this study, we examined the effects of relative positioning of attacker-defender dyads to the basket on interpersonal coordination tendencies in basketball. To achieve this aim, four right-hand dominant basketball players performed in a 1 vs. 1 sub-phase, at nine different playing locations relative to the basket (from 0° to 180°, in 20° increments). Performers' movement displacement trajectories were video-recorded and digitized in 162 trials. Results showed that interpersonal coordination tendencies changed according to the scaling of the relative position of performers to the basket. Stable in-phase modes of coordination were observed between performers' longitudinal and lateral displacements (50.47% and 43.02%) on the left side of the court. On the right side of the court, a shift in the dominant mode of coordination was observed to a defender lead-lag of -30°, both for longitudinal and lateral displacements (30.51% and 32.65%). These results suggest how information about dribbler hand dominance and relative position to the basket may have constrained attacker-defender coordination tendencies in 1 vs. 1 sub-phases of basketball.     

Robust regulation for a 3-DOF helicopter via sliding-mode observation and identification

This paper tackles the problem of robust output regulation for a 3-DOF helicopter. The considered system is subjected to model uncertainties and external perturbations. A sliding mode observer is used to estimate the state vector in finite time and identify the uncertainties and perturbations using the information of the equivalent output injection. Based on these estimations a robust regulation controller is designed. Experimental results show the feasibility of this approach.     

What hampers innovation? Revealed barriers versus deterring barriers

Innovating firms are likely to face several challenges and experience different types of barriers. In this paper we argue that it is necessary to distinguish between two kinds of barriers to innovation. The first corresponds to what we describe as revealed barriers and reflects the degree of difficulty of the innovation process and the learning experience consequent on the firm engaging in innovation activity. The second type of impediment, which we label deterring barriers, encompasses the obstacles that prevent firms from committing to innovation. We use data from the 4th UK Community Innovation Survey (CIS4) to investigate the relationship between firms’ engagement in innovation and their assessment of the barriers to innovation. We show that the relationship is curvilinear in the case of costs and market barriers. These results have important implications for innovation policy and innovation management.     

Approaches to studying in higher education Portuguese students: a Portuguese version of the approaches and study skills inventory for students

This paper examines the validity of the Approaches and Study Skills Inventory for Students—short version (ASSIST; Tait et al. in Improving student learning: Improving students as learners, 1998), to be used with Portuguese undergraduate students. The ASSIST was administrated to 566 students, in order to analyse a Portuguese version of this inventory. Exploratory factor analysis (principal axis factor analysis followed by direct oblimin rotation) reproduced the three main factors that correspond to the original dimensions of the inventory (deep, surface apathetic and strategic approaches to learning). The results are consistent with the background theory on approaches to learning. Additionally, the reliability analysis revealed acceptable internal consistency indexes for the main scales and subscales. This inventory might represent a valuable research tool for the assessment of approaches to learning among Portuguese higher education students.     

Developing a ‘leading identity’: the relationship between students’ mathematical identities and their career and higher education aspirations

The construct of identity has been used widely in mathematics education in order to understand how students (and teachers) relate to and engage with the subject (Kaasila, 2007; Sfard & Prusak, 2005; Boaler, 2002). Drawing on cultural historical activity theory (CHAT), this paper adopts Leont’ev’s notion of leading activity in order to explore the key ‘significant’ activities that are implicated in the development of students’ reflexive understanding of self and how this may offer differing relations with mathematics. According to Leont’ev (1981), leading activities are those which are significant to the development of the individual’s psyche through the emergence of new motives for engagement. We suggest that alongside new motives for engagement comes a new understanding of self—a leading identity—which reflects a hierarchy of our motives. Narrative analysis of interviews with two students (aged 16–17 years old) in post-compulsory education, Mary and Lee, are presented. Mary holds a stable ‘vocational’ leading identity throughout her narrative and, thus, her motive for studying mathematics is defined by its ‘use value’ in terms of pursuing this vocation. In contrast, Lee develops a leading identity which is focused on the activity of studying and becoming a university student. As such, his motive for study is framed in terms of the exchange value of the qualifications he hopes to obtain. We argue that this empirical grounding of leading activity and leading identity offers new insights into students’ identity development.     

Literacy,competence and meaning‐making: a human sciences approach

This semiotically informed article problematizes the concept of literacy as an aesthetic activity rather than reading skills and offers strategies for assessing young readers’ understanding of fictional texts. Although not based on empirical research, the essay refers to and theorizes from extensive field studies of children’s responses to literature. The concept of the implied reader, derived from reception theories, is employed to explore the skills demanded in order to make meaning from fictional texts. The essay presents a number of interpretative codes, including anticipatory, narrative, hermeneutic, semic, symbolic and referential. The implication of these codes is investigated in their relevance for texts specifically addressed to young readers. The article argues that literary competence is an essential component of a child’s intellectual growth that should be trained and encouraged, and that the acknowledgement of this competence it is of overall importance for educational research as well as for practitioners.     

Faculty and student perceptions of outstanding university teachers in the USA and Russia

The majority of research that relates teacher characteristics to student learning in the university has come from Western universities. Using various methodologies, research continues to examine the characteristics of outstanding university teachers. Much of that research in the USA assesses faculty and student perspectives. However, there are nearly no cross‐cultural comparisons on this issue. We examined faculty and student perspectives about outstanding university teachers in the USA and in Russia. Faculty members and students at the University of Central Arkansas, Orel State University and Moscow City University rated the qualities of outstanding teachers on the Teacher Behaviors Checklist (TBC). Results showed significant positive correlations for the relative importance of teacher characteristics across the six participant groups. There did not appear to be any substantial differences between the American and Russian counterparts for 21 of the 28 specific teacher characteristics. The comparison of American and Russian faculty and students suggests more universality than cross‐cultural differences in the characteristics of outstanding university teachers.