Search results for "activity"

"A1 receptors mediate the inhibitory effects of adenosine on the contractility in mouse ileum.”

2008

2004

We investigated how the synthesis of cAMP, stimulated by isoproterenol acting through β-adrenoreceptors and Gs, is strongly amplified by simultaneous incubation with baclofen. Baclofen is an agonist of δ-aminobutyric acid type B receptors [GABAB], known to inhibit adenylyl cyclase via Gi. Because these agents have opposite effects on cAMP levels, the unexpected increase in cAMP synthesis when they are applied simultaneously has been intensively investigated. From previous reports, it appears that cyclase type II contributes most significantly to this phenomenon. We found that simultaneous application of isoproterenol and baclofen specifically influences the association/dissociation of molec…

Physical activity and fat-free mass during growth and in later life.

2021

ABSTRACT Background Physical activity may be a way to increase and maintain fat-free mass (FFM) in later life, similar to the prevention of fractures by increasing peak bone mass. Objectives A study is presented of the association between FFM and physical activity in relation to age. Methods In a cross-sectional study, FFM was analyzed in relation to physical activity in a large participant group as compiled in the International Atomic Energy Agency Doubly Labeled Water database. The database included 2000 participants, age 3–96 y, with measurements of total energy expenditure (TEE) and resting energy expenditure (REE) to allow calculation of physical activity level (PAL = TEE/REE), and cal…

Influence of Guideline Operationalization on Youth Activity Prevalence in the International Children's Accelerometry Database

2022

Introduction: The United Kingdom and World Health Organization recently changed their youth physical activity (PA) guidelines from 60 minutes of moderate-vigorous PA (MVPA) every day, to an average of 60 minutes of MVPA per day, over a week. The changes are based on expert opinion due to insufficient evidence comparing health outcomes associated with different guideline definitions. Further, inconsistent guideline operationalization impairs understanding of physical inactivity prevalence. This study used the International Children’s Accelerometry Database to compare approaches to calculating PA compliance among youth and associations with health indicators. Methods: Cross-sectional accelero…

Participation in organized sports is associated with decreased likelihood of unhealthy lifestyle habits in adolescents

2018

Adolescence is a pivotal time for investing in both present and future health. Thus, it is important to identify arenas for promoting positive adolescent health behaviors and preventing negative ones. The aim of this study was to investigate the associations between organized sports participation (OSP) and a broad range of lifestyle habits in Norwegian adolescents. A comprehensive survey was completed by 13 269 junior high and high school students in southern Norway. Multivariable binary logistic regression models, adjusted for gender, age, and parental education, were used to investigate the associations between OSP and adolescent substance use, dietary habits, physical activity level, pas…

Young People in the Social World of Physical Activities : Meanings and Barriers

2022

Physical inactivity has become one of the leading risk factors for non-communicable diseases (NCDs) and death worldwide. From the future perspective it is alarming that in the group of young people few meet the recommendations. In this respect, physical activity promotion in general and physical education have challenges and new approaches are needed. In this study, the theoretical framework is based on the physical activity relationship (PAR) approach and the barriers were grouped according to the ecological model. The aim of the study was firstly to present both the meanings and barriers of physical activity in a comprehensive Finnish population of 11–15 year old (n = 2728) and secondly t…

SINGLE-TRIAL BASED INDEPENDENT COMPONENT ANALYSIS ON MISMATCH NEGATIVITY IN CHILDREN

2010

Independent component analysis (ICA) does not follow the superposition rule. This motivates us to study a negative event-related potential — mismatch negativity (MMN) estimated by the single-trial based ICA (sICA) and averaged trace based ICA (aICA), respectively. To sICA, an optimal digital filter (ODF) was used to remove low-frequency noise. As a result, this study demonstrates that the performance of the sICA+ODF and aICA could be different. Moreover, MMN under sICA+ODF fits better with the theoretical expectation, i.e., larger deviant elicits larger MMN peak amplitude.

Physical activity and aerobic fitness in relation to local and interhemispheric functional connectivity in adolescents' brains

2021

Abstract Introduction Adolescents have experienced decreased aerobic fitness levels and insufficient physical activity levels over the past decades. While both physical activity and aerobic fitness are related to physical and mental health, little is known concerning how they manifest in the brain during this stage of development, characterized by significant physical and psychosocial changes. The aim of the study is to examine the associations between both physical activity and aerobic fitness with brains’ functional connectivity. Methods Here, we examined how physical activity and aerobic fitness are associated with local and interhemispheric functional connectivity of the adolescent brai…

Adolescent Self-Reported Physical Activity and Autonomy : A Case for Constrained and Structured Environments?

2015

The provision of autonomy supportive environments that promote physical activity engagement have become popular in contemporary youth settings. However, questions remain about whether adolescent perceptions of their autonomy have implications for physical activity. The purpose of this investigation was to examine the association between adolescents’ self-reported physical activity and their perceived autonomy. Participants (n = 384 adolescents) aged between 12 and 15 years were recruited from six secondary schools in metropolitan Brisbane, Australia. Self-reported measures of physical activity and autonomy were obtained. Logistic regression with inverse probability weights were used to exam…

Lung CD11c+ cells from mice deficient in Epstein-Barr virus-induced gene 3 (EBI-3) prevent airway hyper-responsiveness in experimental asthma

2007

Epstein-Barr virus-induced gene (EBI)-3 codes for a soluble type 1 cytokine receptor homologous to the p40 subunit of IL-12 that is expressed by antigen-presenting cells following activation. Here, we analyzed the functional role of EBI-3 in a murine model of asthma associated with airway hyper-responsiveness (AHR) in ovalbumin-sensitized mice. Upon allergen challenge, EBI-3-/- mice showed less severe AHR, decreased numbers and degranulation of eosinophils and a significantly reduced number of VCAM-1+ cells in the lungs as compared to wild-type littermates. We thus analyzed lung CD11c+ cells before and after allergen challenge in these mice and found that before allergen challenge, lung CD1…