High-volume resistance training reduces postprandial lipaemia in postmenopausal women

The aim of this study was to compare the effects of 11 weeks of low-volume resistance training (LVRT) and high-volume resistance training (HVRT) on muscle strength, muscle thickness (MT), and postprandial lipaemia (PPL) in postmenopausal women. Thirty-six healthy and untrained postmenopausal women (age, 58.9 ± 5.8 years; 68.6 ± 10.3 kg; and BMI, 26.9 ± 4.8 kg · m^?2) participated in resistance training 3× per week for 11 weeks (HVRT = 12; LVRT = 13; and control group = 11). Biochemical variables, both pretraining and post-training, were evaluated 16 h after the administration of an oral fat tolerance test (OFTT) and metabolic variable during [energy expenditure (EE)] and after training session [excess postexercise oxygen consumption (EPOC)]. Muscle strength (1 RM) and MT were also calculated, and no significant differences were observed between the groups for PPL (mmol · L^?1 per 5 h) as measured by glucose, high-density lipoprotein, low-density lipoprotein, and total cholesterol. EE total (EE + EPOC; 6.12 ± 1.21 MJ vs. 2.26 ± 0.85 MJ), resting fat oxidation (5.52 ± 1.69 g · h^?1 vs. 4.11 ± 1.12 g · h^?1); MT (vastus medialis, 21.4 ± 1.8 mm vs. 18.4 ± 1.2 mm and vastus lateralis 22.3 ± 1.2 mm vs. 20.8 ± 1.3 mm); triacylglycerol (TAG) 0, 1, 2, 4; and 5 h after OFTT, TAG area under the curve (AUC) (5.79 ± 0.42 vs. 7.78 ± 0.68), and incremental AUC (?46.21 ± 14.42% vs. 7.78 ± 4.68%) were all significantly different post-training for HVRT versus LVRT, respectively (P < 0.05). The results of this investigation suggest that HVRT reduces PPL in postmenopausal women.     

Movement behaviors and their association with depressive symptoms in Brazilian adolescents: A cross-sectional study

Background:Physical activity,sleep,and sedentary behaviors compose 24-h movement behaviors and have been independently associated with depressive symptoms.However,it is not clear whether it is the movement behavior itself or other contextual factors that are related to depressive symptoms.The objective of the present study was to examine the associations between self-reported and accelerometer-measured movement behaviors and depressive symptoms in adolescents.Methods:Cross-sectional data from 610 adolescents(14-18 years old)were used.Adolescents answered questions from the Center for Epidemiological Studies Depression scale and reported time spent watching videos,playing videogames,using social media,time spent in various physical activities,and daytime sleepiness.Wrist-worn accelerometers were used to measure sleep duration,sleep efficiency,sedentary time,and physical activity.Mixed-effects logistic regressions were used.Results:Almost half of the adolescents(48%)were classified as being at high risk for depression(score≥20).No significant associations were found between depressive symptoms and accelerometer-measured movement behaviors,self-reported non-sport physical activity,watching videos,and playing videogames.However,higher levels of self-reported total physical activity(odd ratio(OR)=0.92,95%confidence interval(95%CI):0.86-0.98)and volume of sports(OR=0.88,95%CI:0.79-0.97),in minutes,were associated with a lower risk of depression,while using social media for either 2.0-3.9 h/day(OR=1.77,95%CI:1.58-2.70)or>3.9 h/day(OR=1.67,95%CI:1.10-2.54),as well as higher levels of daytime sleepiness(OR=1.17,95%CI:1.12-1.22),were associated with a higher risk of depression.Conclusion:What adolescents do when they are active or sedentary may be more important than the time spent in the movement behaviors because it relates to depressive symptoms.Targeting daytime sleepiness,promoting sports,and limiting social media use may benefit adolescents.     

Observations sur la dimension pratique dans la formation des enseignants

The strongpoints on which to plan the initial education and training of teachers are dealt with. On the training side two elements are considered: that part of training linked to learning processes, and the other part facing the social life of classroom and school, social and affective growth, civic education. It is advocated that the interaction between subject‐matter and its construction/transmission could take place through practical experimental paths within the actual work of school.     

The difficulty of sit-ups tests: an empirical investigation.

This study estimated the difficulty of various sit-ups tests using an item response theory (IRT) model, the Rasch Poisson Counts model. Scores were obtained on 18 sit-ups tests. All tests were thought to vary in difficulty based on clinical observations. Item difficulty was defined by the Poisson model as the difficulty of Step 1, where the difficulty of a step represented the difficulty of completing a sit-up. The difficulty values of the tests ranged from -4.02 to -3.57. The easiest test was executed with hands on thighs and feet anchored. Most tests had good fit values. The results demonstrated that a variety of sit-ups tests can provide a range of difficulties and variety in forming a sit-ups test bank.     

Engineered three-dimensional microfluidic device for interrogating cell-cell interactions in the tumor microenvironment

Stromal cells in the tumor microenvironment play a key role in the metastatic properties of a tumor. It is recognized that cancer-associated fibroblasts (CAFs) and endothelial cells secrete factors capable of influencing tumor cell migration into the blood or lymphatic vessels. We developed a microfluidic device that can be used to image the interactions between stromal cells and tumor cell spheroids in a three dimensional (3D) microenvironment while enabling external control of interstitial flow at an interface, which supports endothelial cells. The apparatus couples a 200-μm channel with a semicircular well to mimic the interface of a blood vessel with the stroma, and the design allows for visualization of the interactions of interstitial flow, endothelial cells, leukocytes, and fibroblasts with the tumor cells. We observed that normal tissue-associated fibroblasts (NAFs) contribute to the “single file” pattern of migration of tumor cells from the spheroid in the 3D microenvironment. In contrast, CAFs induce a rapid dispersion of tumor cells out of the spheroid with migration into the 3D matrix. Moreover, treatment of tumor spheroid cultures with the chemokine CXCL12 mimics the effect of the CAFs, resulting in similar patterns of dispersal of the tumor cells from the spheroid. Conversely, addition of CXCL12 to co-cultures of NAFs with tumor spheroids did not mimic the effects observed with CAF co-cultures, suggesting that NAFs produce factors that stabilize the tumor spheroids to reduce their migration in response to CXCL12.     

Investigating how college students’ task definitions and plans relate to self-regulated learning processing and understanding of a complex science topic

Winne and Hadwin (2008) identified four phases of self-regulated learning (SRL) including defining the task, setting goals and making plans, studying (i.e., learning), and adaptation. The vast majority of SRL research has focused on processing during the third phase, studying. In this study, we developed coding rubrics that allowed us to examine how the results of college students’ processing during phases one and two of Winne and Hadwin’s model, task definitions and plans, affected their SRL processing while learning with a hypermedia learning environment (HLE), and their subsequent academic performance. Our findings showed that, on average, participants gained both factual knowledge and integrated conceptual understanding over the course of learning with the HLE. The quality of participants’ task definitions and plans at pretest, as well as their SRL processing during learning, were related to learning outcomes. On average, participants’ task definitions improved from pretest to posttest. The findings from this study and the associated coding methodologies have implications for educational research and practice.     

Outcasts on the inside: academics reinventing themselves online

Recent developments in digital scholarship point out that academic practices supported by technologies may not only be transformed through the obvious process of digitization, but also renovated through distributed knowledge networks that digital technologies enable, and the practices of openness that such networks develop. Yet, this apparent freedom for individuals to re-invent the logic of academic practice comes at a price, as it tends to clash with the conventions of a rather conservative academic world. In other words, it may still take some time until academia and the participatory web can fully identify themselves with one another as spaces of ‘public intellectualism’, scholarly debate and engagement. Through a narrative inquiry approach, this research explores how academic researchers engaged in digital scholarship practices perceive the effects of their activity on their professional identity. Pierre Bourdieu’s concept of habitus is used as a theoretical construct and method to capture and understand the professional trajectories of the research participants and the significance of their digital practices on their perceived academic identity. The research suggests that academics engaged in digital practices experience a disjointed sense of identity. The findings presented in this article illustrate how experiences with and on the participatory web inform a new habitus which is at odds with a habitus that is traditionally expected in academia.     

The Difficulty of Sit-Ups Tests: An Empirical Investigation

Abstract

This study estimated the difficulty of various sit-ups tests using an item response theory (IRT) model, the Rasch Poisson Counts model Scores were obtained on 18 sit-ups tests. All tests were thought to vary in difficulty based on clinical observations. Item difficulty was defined by the Poisson model as the difficulty of Step 1, where the difficulty of a step represented the difficulty of completing a sit-up. The difficulty values of the tests ranged from ?4.02 to ?3.57. The easiest test was executed with hands on thighs and feet anchored. Most tests had good fit values. The results demonstrated that a variety of sit-ups tests can provide a range of difficulties and variety in forming a sit-ups test bank.     

Item Response Theory and the Measurement of Motor Behavior

Abstract

Item response theory (IRT) has been the focus of intense research and development activity in educational and psychological measurement during the past decade. Because this theory can provide more precise information about test items than other theories usually used in measuring motor behavior, the application of IRT in physical education and exercise science merits investigation. In IRT, the difficulty level of each item (e.g., trial or task) can be estimated and placed on the same scale as the ability of the examinee. Using this information, the test developer can determine the ability levels at which the test functions best. Equating the scores of individuals on two or more items or tests can be handled efficiently by applying IRT. The precision of the identification of performance standards in a mastery test context can be enhanced, as can adaptive testing procedures. In this tutorial, several potential benefits of applying IRT to the measurement of motor behavior were described. An example is provided using bowling data and applying the graded-response form of the Rasch IRT model. The data were calibrated and the goodness of fit was examined. This analysis is described in a step-by-step approach. Limitations to using an IRT model with a test consisting of repeated measures were noted.     

Functional hamstrings: quadriceps ratios in elite women's soccer players

Abstract

We compared starters and non-starters for various isokinetic strength variables in elite women’s soccer players. A convenience sample of 10 starters (mean ± s; age = 20 ± 2 years; height = 170 ± 4 cm; body mass = 65 ± 5 kg) and 7 non-starters (age = 20 ± 1 years; height = 164 ± 3 cm; body mass = 63 ± 4 kg) performed maximal voluntary muscle actions of the leg extensors (concentric) and flexors (eccentric) on an isokinetic dynamometer in order to measure concentric peak torque for the leg extensors, eccentric peak torque for the leg flexors, and the functional hamstrings:quadriceps (H:Q) ratio at 1.047 rad · s^-1 and 4.189 rad · s^-1 concentric peak torque for the leg extensors was not different between starters and non-starters. However, it was greater at 1.047 rad · s^-1 than at 4.189 rad · s^-1 in both groups. Eccentric peak torque for the leg flexors was greater for the starters versus non-starters at 4.189 rad · s^-1. Eccentric strength of the leg flexors at fast movement velocities may be used as an effective physiological profile and may discriminate between playing status in elite women’s soccer players.