Near-infrared spectroscopy-derived total haemoglobin as an indicator of changes in muscle blood flow during exercise-induced hyperaemia

ABSTRACT

Blood flow changes in response to exercise have been attributed, among other factors, to the effect of vasodilators factors on the microvasculature, suggesting a close relationship between small blood vessels and conducting arteries. The main purpose of this study was to determine the relationship between the changes in near infrared spectroscopy (NIRS)-derived total haemoglobin ([tHb]) and muscle oxygen saturation (SmO₂) signals and femoral artery blood flow in response to resistance exercise at fast- and slow-velocity muscle contraction. The study randomised crossover design included twelve participants. NIRS and blood flow measurements were continuously monitored before, during, and 5 min after the exercise protocol. There was a significant correlation between [tHb] reperfusion slope ([tHb]_slope) and peak blood flow (BF_peak) after slow- and fast-velocity muscle contraction (r = 0.83, p = 0.0008 and r = 0.72, p = 0.0080, respectively). No significant correlation existed between the SmO₂ reperfusion slope (SmO_{2_slope}) and BF_peak after both slow- and fast-velocity muscle contraction exercise (r = ?0.46, p = 0.1253 and r = 0.33, p = 0.2841, respectively). This study demonstrated a strong relationship between the NIRS-derived [tHb] and Doppler ultrasound BF during the recovery period of dynamic resistance exercise at both slow- and fast-velocity contraction.     

Dynamics of need-supportive and need-thwarting teaching behavior: the bidirectional relationship with student engagement and disengagement in the beginning of a lesson

Background: According to the classroom ecology paradigm, teachers and students interpret, predict, and respond to each other repeatedly in a reciprocal way. Such a reciprocal relationship is reflected in bidirectional interactions between a teacher's behavior and student (dis)engagement, an issue that has been confirmed in longitudinal studies including measures at different moments in a school year.

Aims: Starting from the perspective of self-determination theory, the aim of the present study was to investigate bidirectional relationships between student (dis)engagement and need-supportive and need-thwarting teaching behavior during the first 15?min of a lesson.

Sample &; method: The first three 5-minute intervals of 100 videotaped physical education lessons taught by 100 different teachers (51.9% male, M age?=?37.5?±?10.9 years) were observed and coded for need-supportive and need-thwarting teaching behavior, student engagement, and student disengagement. Correlations were calculated to explore relationships between student (dis)engagement and teaching behavior over the first 15?minutes of a PE lesson. Next, path analyses were conducted to analyze 5-to-5?minute interactions between teaching behavior and student (dis)engagement.

Results: Student engagement correlated positively and disengagement correlated negatively with need support, while engagement correlated negatively and disengagement correlated positively with need-thwarting over the first 15?minutes of the lesson. There were few significant relationships between student engagement and teachers’ behavior across and between each of the three 5-minute intervals. Only when teachers provided more need support during the first 5?minutes of the lesson, students were more engaged in the third 5?minutes of the lesson. When students were more disengaged during the first 5?minutes of the lesson, teachers displayed less need support in the following 10?minutes of the lesson. In contrast, student disengagement in the second 5?minutes of the lesson related to more need support in the next 5?minutes. Most of the within-interval relationships between student engagement and teachers’ behaviors were inconsistent, but we did find positive relationships between student disengagement and need-thwarting teaching behaviors in the first and third interval, suggesting a rather direct and momentary within 5-minute intervals interaction between teachers and students.

Conclusions: Findings of the present observational study suggest that, although overall relationships between student (dis)engagement and teachers’ behavior were in the expected directions, the picture might become more complicated when relationships are investigated according to the timing of the lesson, an issue that has remained uncovered in self-reported studies. While student disengagement was related to less need support and more need-thwarting teaching behaviors, more detailed analyses showed that it was particularly student disengagement in the beginning of a lesson that elicited less positive teaching behaviors. When students display disengagement further along in the first 15?minutes of the lesson, teachers seemed to respond in a more need-supportive way to student disengagement. Such findings provide interesting insights to build interventions for teachers around certain critical moments during the lesson, for example when dealing with student disengagement at a specific moment in the lesson.     

The Use of Visual-Tactile Communication Strategies by Deaf and Hearing Fathers and Mothers of Deaf Infants

This article presents the results of a study comparing deaf and hearing parents in the use of visual-tactile communication strategies during interaction with their hearing-impaired children between 18 and 24 months of age. The study includes 17 deaf and hard-of-hearing children and 33 parents, covering hearing mothers (n = 12), hearing fathers (n = 11), deaf mothers (n = 5), and deaf fathers (n = 5). The four groups of parents are compared in the use of visual-tactile communication strategies during free play with their children. Overall results show that deaf mothers and deaf fathers differ significantly from hearing parents in the use of a visual communication style adapted to the developmental communication needs and abilities related to the 18- to 24-month age period. The study pays special attention to differences in visual-tactile communication strategies according to hearing status, gender, use of languages, and communication modes.     

“Strategy redundancy” and its impact on the effectiveness of technology-enhanced instruction: A case study

In this study, eight teachers and three college students involved in a graduate-level Internet course developed skill in using Internet tools and authoring webware materials. The course followed a traditional classroom-based format, but was supported by a webware package developed by the instructor (http://www.sover.net/~milcasa/503). A case study research methodology was utilized to investigate how the implementation of a “strategy redundancy” device, which consisted of the instructor's use of five teaching strategies and their mirroring in five of the features of the webware package, affected the participants′ learning outcomes. Qualitative and quantitative data were collected from seven sources. A causal relationship was found between the “strategy redundancy” device and the effectiveness of the course. The need to emphasize the “quality” of the teaching/ learning experience, vis-à-vis the “cost savings” value of technology tools, and the need to conciliate constructivist and instructivist learning were highlighted.     

An international collaborative investigation of beginning seventh grade students' understandings of scientific inquiry: Establishing a baseline

Although understandings of scientific inquiry (as opposed to conducting inquiry) are included in science education reform documents around the world, little is known about what students have learned about inquiry during their elementary school years. This is partially due to the lack of any assessment instrument to measure understandings about scientific inquiry. However, a valid and reliable assessment has recently been developed and published, Views About Scientific Inquiry (VASI; Lederman et al. [2014], Journal of Research in Science Teaching, 51, 65–83). The purpose of this large-scale international project was to collect the first baseline data on what beginning middle school students have learned about scientific inquiry during their elementary school years. Eighteen countries/regions spanning six continents including 2,634 students participated in the study. The participating countries/regions were: Australia, Brazil, Chile, Egypt, England, Finland, France, Germany, Israel, Mainland China, New Zealand, Nigeria, South Africa, Spain, Sweden, Taiwan, Turkey, and the United States. In many countries, science is not formally taught until middle school, which is the rationale for choosing seventh grade students for this investigation. This baseline data will simultaneously provide information on what, if anything, students learn about inquiry in elementary school, as well as their beginning knowledge as they enter secondary school. It is important to note that collecting data from all of the approximately 200 countries globally was not humanly possible, and it was also not possible to collect data from every region of each country. The results overwhelmingly show that students around the world at the beginning of grade seven have very little understandings about scientific inquiry. Some countries do show reasonable understandings in certain aspects but the overall picture of understandings of scientific inquiry is not what is hoped for after completing 6 years of elementary education in any country.     

Cognitive processes and math performance: a study with children at third grade of basic education

The present study aims to examine the relationship between cognitive factors and mathematical achievement in primary education. Participants were 103 Portuguese third grade students, aged 8 and 9. All participants completed a battery for working memory (WMTB-C), a test of general intelligence (Raven's Progressive Color Matrices), a selective attention test (d2), and mathematical exercises (arithmetic story problems and measurement skills). Data suggested significant correlations between math performance, executive, visuospatial sketchpad and g factor. Our findings suggest the importance of the cognitive factors in two mathematical domains considered. In consonance with the research in this area, we conclude that working memory (WM) assumes an important role in different math curricular achievements.     

Measuring the impact of inquiry-based learning on outcomes and student satisfaction

The aim of this study is to determine the impact of inquiry-based learning (IBL) on students’ academic performance and to assess their satisfaction with the process. Linear and logistic regression analyses show that examination grades are positively related to attendance at classes and tutorials; moreover, there is a positive significant relationship between academic performance and IBL, which is considered useful for better understanding of the subject. While students’ satisfaction is directly associated with class attendance and motivation and with the perceived usefulness of IBL, it is unaffected by attendance at tutorials. We conclude, therefore, that students become more involved in learning and acquire increased knowledge of the subject when an IBL-based method is followed.     

The influence of using ICT in high-skills competences and ICT competences. A structural model

Education and Information Technologies - University students have to master new competences to be able to completely form part of Knowledge Society, which are known as 21st-century competences....     

Promoting Science Outdoor Activities for Elementary School Children: Contributions from a research laboratory

The purposes of the study were to analyse the promotion of scientific literacy through practical research activities and to identify children's conceptions about scientists and how they do science. Elementary school children were engaged in two scientific experiments in a marine biology research laboratory. A total of 136 students answered a questionnaire about their previous habits towards science and carried out the following actions: (1) a guided visit to the laboratory, (2) a brief presentation of the research theme, (3) the development of two experiments, and (4) a questionnaire about the experiments and science conceptions. The research methods included observation, document analysis, and content analysis of the answers to the questionnaires. Additionally, each visit was video recorded in order to design learning materials. The results revealed that most of the pupils were able to follow every stage of experimentation. However, some of them misinterpreted results and conclusions. One implication of the study is that this type of outdoor activity is extremely important to promote meaningful science learning in children, but more care should be taken in practical science activities so that children can overcome some common difficulties when performing scientific inquiry.