Classroom teachers’ perception about physical education and physical activity: A typology

Introduction: According to the socioecological model teachers may act as facilitators or barriers in a school physical activity (PA) program. Objectives: The purpose of this study was to characterize classroom teachers’ perceptions about Physical Education (PE). Methods: 297 teachers answered a questionnaire about PE past experience, status, aims, and academic benefits of PA. The Multiple Correspondence Analysis was used aiming to identify teachers’ profiles. Results: Dimension 1 combines the view that the PA affects academic achievement (AA) with the idea that PE must be optional or compulsory, but non-examinable. In dimension 2 the biggest difference is between a standard that refers to a relatively neutral position in relation to PA (PE as important for promotion of healthy lifestyles associated with the idea that PA does not affect AA, and PE should be compulsory but non-examinable), as opposed to positions, either in favour (PA benefits AA and PE should be compulsory and examinable) or against PA (PE should be optional). The joint analysis of the two dimensions allowed to identify three distinct patterns of teacher’s perceptions which made possible to build a typology, regardless the cluster they belong to. Considering their personal experience teachers make a misjudgment of PE in schools they attended specially in cluster 3. As for the relation between PA and AA, most teachers say that the PA benefits AA (65% in cluster 1; 96% in cluster 2). In cluster 3, 70% of the teachers say that PA impairs AA. Conclusions: These results support the importance of the earliest good experiences in PE, in generating positive attitudes towards PE. PE teachers should explain to other teachers that PA does not affect academic performance, and that PA prevents deviant behaviours.info:eu-repo/semantics/publishedVersio

Níveis de atividade física de adolescentes portugueses no primeiro período de confinamento devido à pandemia de COVID-19 e as primeiras atividades de professores e treinadores: Um estudo transversal

Due to the COVID-19 pandemic, social confinement was declared in Portugal on 19th March 2020. Schools and sports clubs were closed, access to all sports and leisure facilities was limited, and young people have experienced restrictions regarding the practice of physical activities and sports. The purpose of this study was to identify the physical activity (PA) levels and sports participation of adolescents before and during confinement, with whom they practice during restrictions and to identify the activities adopted by their physical education (PE) teachers and sports coaches to keep them physically active. An online survey was conducted between March 27th and April 14th 2020. A total of 3,012 Portuguese adolescents (57% females) aged between 10 and 19 years old (14.3±2.4 years old) took part in this study. Wilcoxon test and paired-sample t-test and chi-square test of independence were used in the data analysis. The results show that the number of students engaged in PA increased during the lockdown (72.7% to 88.2%). For those who practiced PA before lockdown, the frequency of PA decreased from 4.7 sessions/week to 4.4 sessions/week (during confinement). For those who did not practice PA before confinement, they started by doing 4.1 sessions/week. The vast majority of PE teachers (77.3%) proposed some pedagogical activities such as video conference classes (53.6%). Regarding the coaches, 53.4% proposed some activity, mainly time circuit training, walking and cycling (around 18% each), or specific training exercises and video conference classes (about 12% each). The number of students who increased their regular PA practice can be justified by the immediate intervention of PE teachers, who implemented several online activities, or because students were able to choose different options to stay active.info:eu-repo/semantics/publishedVersio

The impact of non-physical education teachers’ perceptions on the promotion of active and healthy lifestyles: A cross-sectional qualitative study

(1) Background: In accordance with the socio-ecological model of physical education (PE), school-based interventions to promote physical activity (PA) will only be successful if a change occurs in the perceptions and attitudes of all. This study sought to analyze non-PE teachers experiences in PE and how these experiences relate to the value they attribute to PE, sports and PA, and the impact of teachers’ perceptions on promoting active lifestyles in the school’s context. A mixed-method study was adopted. (2) Methods: A survey about the perceptions in PE was applied to 297 teachers (58 male). From this sample, 24 teachers were selected for three focus groups considering their experiences in PE (e.g., good experiences, bad experiences). MaxQda was used for the inductive qualitative data analysis. (3) Results: Teachers who have had good experiences in PE value the role of PE and sports. Teachers who have had bad experiences do not value the importance of PE or sports. (4) Conclusions: The results support the importance of having good experiences in PE to generate positive attitudes. Thus, teachers who have had bad experiences in PE may constitute barriers that will hinder the promotion of an educational climate that promotes PA and active lifestyles in schools.info:eu-repo/semantics/publishedVersio

Hierarchical Spatial Organization of Geographical Networks

In this work we propose the use of a hirarchical extension of the polygonality index as a means to characterize and model geographical networks: each node is associated with the spatial position of the nodes, while the edges of the network are defined by progressive connectivity adjacencies. Through the analysis of such networks, while relating its topological and geometrical properties, it is possible to obtain important indications about the development dynamics of the networks under analysis. The potential of the methodology is illustrated with respect to synthetic geographical networks.Comment: 3 page, 3 figures. A wokring manuscript: suggestions welcome

Resposta a adubação fosfatada e a suplementação mineral de bovinos de corte sob pastejo em Brachiaria decumbens.

Comparou-se biológica e economicamente, os efeitos da fertilização fosfatada e da suplementação mineral. sobre o desempenho de bovinos machos da raça Nelore. A forrageira utilizada foi Brachiaria decumbens cv. Basilisk, implantada em um solo Areia Quartzosa distrófica, de baixa fertilidade natural, no município de Sidrolândia, MS. Testou-se o fósforo em dois níveis de adubação (0 e 100 kg de P2O5/ha) sendo 1/3 de superfosfato simples e 2/3 de fosfato de Araxá e dois níveis de suplementação mineral (0 e 500 ppm de P no cocho) na forma de fosfato bicálcico.bitstream/item/131379/1/resposta-adubacao-fosfatada.pd

Recycling of cellulases in lignocellulosic hydrolysates using alkaline elution

The recovery of cellulases from lignin, lignocellulosic hydrolysates and cellulose by alkaline washes at pH 9 and 10 was examined. The effect of the pH on the structural stability of purified Cel7A was analyzed by circular dichroism. Purified Cel7A showed conformational changes at pH 9 and 10 that were reversible at pH 4.8. Temperature influenced the enzymatic hydrolysis of wheat straw and may be critical for the efficiency of cellulase recycling from wheat straw hydrolysates. Operation at moderate temperatures (37 °C) resulted in a rate of saccharification 19% higher than that obtained at 50° C, improving cellulase recycling by 49%. Over 60% of the enzyme activity on the synthetic substrate 4-methylumbelliferyl-β-d-cellobioside (MUC) may be recovered by using a simple alkaline wash. This is thus a promising strategy for enzyme recycling that is simple to implement at industrial scale, economical and effective.The authors acknowledge funding through FP7 KACELLE (Kalundborg Cellulosic Ethanol) project for supporting his work. We also thank Dr. Mai Ostergaard Haven for critical reviewing of the manuscript and Dr. Jane Lindedam for supplying the lignin

A novel bioreactor design for enhanced stem cells proliferation and differentiation in tissue engineered constructs

[Excerpt] Recent studies have shown that culturing undifferentiated stem cells in appropriate biochemical environments and under mechanical stimulation could provide the correct signals for cellular proliferation, differentiation and subsequent extracellular matrix production. This triggered a growing interest about in vitro biomechanically-stimulating culture environments. [...]info:eu-repo/semantics/publishedVersio

Effect of poling on the mechanical properties of β-poly(vinylidene fluoride)

In this work, mechanical and thermal experimental techniques have been applied in order to relate the mechanical response with the microscopic variations of the material. Stress-strain results along the main directions of β-poly(vinylidene fluoride), β-PVDF, in poled and non-poled samples enables to investigate the influence of the poling process on the mechanical response of the material. Further, differential scanning calorimetry experiments allow the investigation of the effect of poling in the degree of crystallinity of the material as well as on the stability of the crystalline phase. Thermogravimetric analysis was used to investigate the kinetics of the thermal degradation of poled and non-poled β-PVDF samples. The differences observed between the two materials suggest that the poling affects the mechanical properties of the material especially in the direction parallel to the polymeric chains and originates changes at a molecular level that remain beyond the melting of the material.(undefined