The effect of caffeine ingestion on human neutrophil oxidative burst responses following time-trial cycling

Abstract

Following fixed-duration exercise of submaximal intensity, caffeine ingestion is associated with an attenuation of the exercise-induced decline in N-formyl-methionyl-phenyl-alanine (f-MLP) stimulated neutrophil oxidative burst. However, the response following high-intensity exhaustive exercise is unknown. Nine endurance-trained male cyclists ingested 6 mg caffeine or placebo per kilogram of body mass 60 min before cycling for 90 min at 70% of maximal oxygen consumption ([Vdot]O_2max) and then performing a time-trial requiring an energy expenditure equivalent to 30 min cycling at 70% maximum power output. Time-trial performance was 4% faster in the caffeine than in the placebo trial (P = 0.043). Caffeine was associated with an increased plasma adrenaline concentration after 90 min of exercise (P = 0.046) and immediately after the time-trial (P = 0.02). Caffeine was also associated with an increased serum caffeine concentration (P < 0.01) after 90 min of exercise and immediately after the time-trial, as well as 1 h after the time-trial. However, the f-MLP-stimulated neutrophil oxidative burst response fell after exercise in both trials (P = 0.002). There was no effect of caffeine on circulating leukocyte or neutrophil counts, but the lymphocyte count was significantly lower on caffeine (20%) after the time-trial (P = 0.003). Our results suggest that high-intensity exhaustive exercise negates the attenuation of the exercise-induced decrease in neutrophil oxidative burst responses previously observed when caffeine is ingested before exercise of fixed duration and intensity. This may be associated with the greater increase in adrenaline concentration observed in the present study.     

Effect of postural changes on 3D joint angular velocity during starting block phase

Abstract

Few studies have focused on the effect of posture during sprint start. The aim of this study was to measure the effect of the modification of horizontal distance between the blocks during sprint start on three dimensional (3D) joint angular velocity. Nine trained sprinters started using three different starting positions (bunched, medium and elongated). They were equipped with 63 passive reflective markers, and an opto-electronic Motion Analysis® system was used to collect the 3D marker trajectories. During the pushing phase on the blocks, norm of the joint angular velocity (NJAV), 3D Euler angular velocity (EAV) and pushing time on the blocks were calculated. The results demonstrated that the decrease of the block spacing induces an opposite effect on the angular velocity of joints of the lower and the upper limbs. The NJAV of the upper limbs is greater in the bunched start, whereas the NJAV of the lower limbs is smaller. The modifications of NJAV were due to a combination of the movement of the joints in the different degrees of freedom. The medium start seems to be the best compromise because it leads, in a short pushing time, to a combination of optimal joint velocities for upper and lower segments.     

The Shifting Relationship between Vocational and Higher Education in France and Germany: towards convergence?

In Europe, the Bologna and Copenhagen Processes in higher education (HE) and vocational education and training (VET) are on the agenda, aiming to create a European educational area. Acknowledging important differences between countries, we compare the evolving relationship between HE and VET. We ask whether and how these two distinct organisational fields in France and Germany have changed in recent decades. Comparing institutional shifts, the article analyses whether long-standing differences in postsecondary education and training systems and the education/economy nexus in these two countries have remained stable. We argue that these countries’ skill formation systems have begun to converge, departing from their original institutionalisation paths. Thus, while the traditional typologies that contrast France and Germany have served as useful heuristic devices, they require revision to adequately represent incremental institutional change in these skill formation systems resulting from endogenous reforms and exogenous pressures due to Europeanisation.     

Longitudinal Trajectories of Four Domains of Parenting in Relation to Adolescent Age and Puberty in Nine Countries

Children, mothers, and fathers in 12 ethnic and regional groups in nine countries (N = 1,338 families) were interviewed annually for 8 years (M_age child = 8–16 years) to model four domains of parenting as a function of child age, puberty, or both. Latent growth curve models revealed that for boys and girls, parents decrease their warmth, behavioral control, rules/limit-setting, and knowledge solicitation in conjunction with children’s age and pubertal status as children develop from ages 8 to 16 across a range of diverse contexts, with steeper declines after age 11 or 12 in three of the four parenting domains. National, ethnic, and regional differences and similarities in the trajectories as a function of age and puberty are discussed.     

Cross-Cultural Associations of Four Parenting Behaviors With Child Flourishing: Examining Cultural Specificity and Commonality in Cultural Normativeness and Intergenerational Transmission Processes

Families from nine countries (N = 1,338) were interviewed annually seven times (M_age child = 7–15) to test specificity and commonality in parenting behaviors associated with child flourishing and moderation of associations by normativeness of parenting. Participants included 1,338 children (M = 8.59 years, SD = 0.68, range = 7–11 years; 50% girls), their mothers (N = 1,283, M = 37.04 years, SD = 6.51, range = 19–70 years), and their fathers (N = 1,170, M = 40.19 years, SD = 6.75, range = 22–76 years) at Wave 1 of 7 annual waves collected between 2008 and 2017. Families were recruited from 12 ethnocultural groups in nine countries including: Shanghai, China (n = 123); Medellín, Colombia (n = 108); Naples (n = 102) and Rome (n = 111), Italy; Zarqa, Jordan (n = 114); Kisumu, Kenya (n = 100); Manila, Philippines (n = 120); Trollhättan & Vänersborg, Sweden (n = 129); Chiang Mai, Thailand (n = 120); and Durham, NC, United States (n = 110 White, n = 102 Black, n = 99 Latinx). Intergenerational parenting (parenting passed from Generation 1 to Generation 2) demonstrated specificity. Children from cultures with above-average G2 parent warmth experienced the most benefit from the intergenerational transmission of warmth, whereas children from cultures with below-average G2 hostility, neglect, and rejection were best protected from deleterious intergenerational effects of parenting behaviors on flourishing. Single-generation parenting (Generation 2 parenting directly associated with Generation 3 flourishing) demonstrated commonality. Parent warmth promoted, and parent hostility, neglect, and rejection impeded the development of child flourishing largely regardless of parenting norms.     

Levelling the playing field between rural schools and urban schools in a HE context: A Scottish case study

At a time when interventions in widening access to, and participation in, higher education aim to maximise impact by engaging with schools located in the most deprived communities, school pupils in rural communities, and who experience deprivation, are, in practice, less likely to benefit. Using statistics available from the Scottish government, we show that state secondary schools located in Scottish remote or rural areas are not well served by the indicators capturing socio-economic, educational, or geographical deprivation widely used in the selection of schools for these outreach interventions. We construct a marker that identifies schools facing higher levels of deprivation than the Scottish average. We argue that (1) this marker is a step in the direction towards levelling the playing field between remote or rural schools and urban schools; and (2) it selects a wider range of schools for outreach interventions.     

Conduct Disorder: the achievement of a diagnosis1

This paper explores the historical shapings behind the diagnosis of conduct disorders. We take as our point of purchase oppositional ways of knowing the subject of conduct disorder—as either pathologically motivated or as the victim of a repressive mandate to control disorderly conduct. We take our cue from Foucault's suggestion that the pursuit of singular motivations behind a phenomenon is not the most fruitful means of understanding its historical appearance. We explore the emergence of the individual with conduct disorder as an appearance contingent upon dispersed agencies of government—an artefact of dispersed technologies for channelling and directing a population.