The malaria parasite cyclic GMP-dependent protein kinase plays a central role in blood-stage schizogony.

A role for the Plasmodium falciparum cyclic GMP (cGMP)-dependent protein kinase (PfPKG) in gametogenesis in the malaria parasite was elucidated previously. In the present study we examined the role of PfPKG in the asexual blood-stage of the parasite life cycle, the stage that causes malaria pathology. A specific PKG inhibitor (compound 1, a trisubstituted pyrrole) prevented the progression of P. falciparum schizonts through to ring stages in erythrocyte invasion assays. Addition of compound 1 to ring-stage parasites allowed normal development up to 30 h postinvasion, and segmented schizonts were able to form. However, synchronized schizonts treated with compound 1 for > or =6 h became large and dysmorphic and were unable to rupture or liberate merozoites. To conclusively demonstrate that the effect of compound 1 on schizogony was due to its selective action on PfPKG, we utilized genetically manipulated P. falciparum parasites expressing a compound 1-insensitive PfPKG. The mutant parasites were able to complete schizogony in the presence of compound 1 but not in the presence of the broad-spectrum protein kinase inhibitor staurosporine. This shows that PfPKG is the primary target of compound 1 during schizogony and provides direct evidence of a role for PfPKG in this process. Discovery of essential roles for the P. falciparum PKG in both asexual and sexual development demonstrates that cGMP signaling is a key regulator of both of these crucial life cycle phases and defines this molecule as an exciting potential drug target for both therapeutic and transmission blocking action against malaria

A coding system to quantify powerful actions in soccer match play: a pilot study

Purpose: The powerful activity profile of elite soccer match play has not been documented appropriately to inform specific maximal power assessment and development criteria. The aims of the current study were to develop a novel soccer specific powerful action (SSPA) notational analysis coding system that could be used to compare frequency and durations of powerful actions during elite youth soccer match play. Methods: Sixteen elite male English Premier League (EPL) Academy players (19 ± 1 yrs) were recorded by an individual camera during sixteen competitive EPL U18 and U21 games. Video footage was analyzed using performance analysis software and SSPAs were coded according to the following categories: initial acceleration, leading acceleration, sprint, unilateral jump and bilateral jump. Results: The novel SSPA coding system demonstrated very good inter- and intra-rater reliability (kappa coefficients ≥ 0.827). Moreover, elite youth EPL soccer players undertook significantly more initial (31 ± 9) and leading (37±12) accelerations than sprints (8±3; p=0.014 and p<0.001, respectively) and jumps (6±5; p=0.002 and p<0.001, respectively). Players performed a significantly greater number of initial and leading accelerations with action durations below 1.5 s compared to above 1.5 s (p=0.001 and p=0.002), respectively. Conclusions: Our novel SSPA coding system provides a highly reliable observational instrument for quantifying the frequency and duration of powerful actions performed during elite soccer match play. In our sample of elite youth soccer players, horizontal accelerations of short duration (<1.5 s) from different starting speeds appear the most dominant powerful action in elite youth soccer match play

Why do bad balls get wickets? The role of congruent and incongruent information in anticipation.

Skilled anticipation is underpinned by the use of kinematic and contextual information. However, few researchers have examined what happens when contextual information suggests an outcome that is different from the event that follows. We aimed to bridge this gap by manipulating the relationship between contextual information and final ball location in a cricket-batting task. We predicted that when contextual information is congruent with the eventual outcome then anticipation would be facilitated. In contrast, when contextual information is incongruent, this would lead to a confirmation bias on kinematic information and result in decreased anticipation accuracy. We expected this effect to be larger in skilled performers who are more able to utilise context. Skilled and less-skilled cricket batters anticipated deliveries presented using a temporally occluded video-based task. We created conditions whereby contextual information and event outcome were either congruent or incongruent. There was a significant skill by condition interaction (p < 0.05). The skilled group anticipated significantly more accurately than the less-skilled group on the congruent trials. Both groups anticipated less accurately on incongruent trials, with the skilled participants being more negatively affected. Skilled performers prioritise contextual information and confirmation bias affects the use of kinematic information available later in the action

The developmental activities of skilled youth CONCACAF soccer players and the contribution of their development system

Small/er soccer nations rely strongly on developing youth athletes into experts in adulthood due to financial, logistical, and coach education constraints. One factor that contributes to this expertise is activities engaged in during childhood. Researchers have described these activities by focusing on larger, well-developed countries that often have larger participation rates and higher competition levels than their smaller counterparts. Therefore, to provide more specific information to support talent development in smaller soccer nations, a survey of the youth development system of a small soccer nation was conducted, alongside recording the developmental activities of skilled and less-skilled soccer players within this system. Key stakeholders (e.g., technical director) completed a youth development system survey. Skilled soccer players (n = 12) who were representing their country at U17 level and less-skilled players (n = 13) that had never played for their country completed a Participation History Questionnaire. Skilled players engaged in significantly higher amounts of individual practice in both childhood and early adolescence compared to less-skilled players. Survey data indicated that the greater amounts of individual practice for the skilled players stemmed from a lack of finances, playing facilities, and a formal coach education program. Results from this study may inform future practices and processes in the youth development systems of small/er soccer nations and their national associations

30 days wild: development and evaluation of a large-scale nature engagement campaign to improve well-being

There is a need to increase people’s engagement with and connection to nature, both for human well-being and the conservation of nature itself. In order to suggest ways for people to engage with nature and create a wider social context to normalise nature engagement, The Wildlife Trusts developed a mass engagement campaign, 30 Days Wild. The campaign asked people to engage with nature every day for a month. 12,400 people signed up for 30 Days Wild via an online sign-up with an estimated 18,500 taking part overall, resulting in an estimated 300,000 engagements with nature by participants. Samples of those taking part were found to have sustained increases in happiness, health, connection to nature and pro-nature behaviours. With the improvement in health being predicted by the improvement in happiness, this relationship was mediated by the change in connection to nature

The validity of an updated metabolic power algorithm based upon Di Prampero’s theoretical model in Elite soccer players

The aim of this study was to update the metabolic power (MP) algorithm (P.VO2, W·kg−1) related to the kinematics data (PGPS, W·kg−1) in a soccer-specific performance model. For this aim, seventeen professional (Serie A) male soccer players (.VO2max 55.7 ± 3.4 mL·min−1·kg−1) performed a 6 min run at 10.29 km·h−1 to determine linear-running energy cost (Cr). On a separate day, thirteen also performed an 8 min soccer-specific intermittent exercise protocol. For both procedures, a portable Cosmed K4b2 gas-analyzer and GPS (10 Hz) was used to assess the energy cost above resting (C). From this aim, the MP was estimated through a newly derived C equation (PGPSn) and compared with both the commonly used (PGPSo) equation and direct measurement (P.VO2). Both PGPSn and PGPSo correlated with P.VO2 (r = 0.66, p < 0.05). Estimates of fixed bias were negligible (PGPSn = −0.80 W·kg−1 and PGPSo = −1.59 W·kg−1), and the bounds of the 95% CIs show that they were not statistically significant from 0. Proportional bias estimates were negligible (absolute differences from one being 0.03 W·kg−1 for PGPSn and 0.01 W·kg−1 for PGPSo) and not statistically significant as both 95% CIs span 1. All variables were distributed around the line of unity and resulted in an under-or overestimation of PGPSn, while PGPSo routinely underestimated MP across ranges. Repeated-measures ANOVA showed differences over MP conditions (F1,38 = 16.929 and p < 0.001). Following Bonferroni post hoc test significant differences regarding the MP between PGPSo and P.VO2 /PGPSn (p < 0.001) were established, while no differences were found between P.VO2 and PGPSn (p = 0.853). The new approach showed it can help the coaches and the soccer trainers to better monitor external training load during the training seasons.© 2020 by the authors. Licensee MDPI, Basel, Switzerland

Using a coproduced educational workshop to change the focus of verbal instructions delivered by professional youth soccer coaches: a case study

Background The predominant instructional method utilised by soccer coaches are verbal instructions that occur whilst (during) players are executing soccer-skill. However, little is known on the specificity of the information contained within. These verbal instructions can guide the learner to either the performance characteristics of a movement (internal focus) or the intended movement effects (external), with the latter known to facilitate superior motor performance, retention, and transfer. Purpose The aims in the present study were to quantify the focus of concurrent verbal instructions utilised by professional youth soccer coaches during drill-based (i.e. isolated) practice activities, and to modulate how these instructions are delivered in coaching sessions following the engagement in a coproduced evidence-based educational workshop. Method Systematic observation was used pre and post the workshop to quantify the nature of verbal instructions delivered by 5 male coaches (31–47 years of age with 4–24 years of coaching experience) across 34 sessions with players from 8 to 13 years of age. For instructions provided during (concurrent) action-execution, we further quantified whether these instructions were focused on motor performance characteristics (internal) or the intended movement outcome effects (external) using criteria outlined in the revised Arizona State University Observation Instrument. To facilitate behaviour change, all coaches engaged in an educational workshop led by skill acquisition specialists (SAS). The workshop was designed so that educational material related to the principles of skill acquisition, and motor control and learning, were presented using a pedagogical delivery method containing verbal information, data presented in illustrations, and videos. In addition, the results that quantified coaching behaviour during the pre-workshop systematic observation period were presented to coaches as quantitative feedback. To guide the coaches to appraise the quantitative feedback in relation to the delivered educational material, the SAS built an educational environment that encouraged discussion opportunities for coaches to compare and appraise feedback with other coaches and process the feedback in relation to data and concepts regarding skill acquisition. Results and findings The pre-workshop systematic observation data indicated that coaches delivered significantly more (64%) verbal instructions whilst (concurrently) players were executing motor skills, compared to before (15%) or after (21%). Within concurrent feedback, coaches used instructions that had a more internal, compared to external focus of attention. Post-workshop data indicated the coaches significantly changed the utilisation of instructions using a greater proportion of external focus. The data confirms coaches deliver a greater proportion of concurrent verbal instructions during coaching sessions focused training drill-based activities, but engaging in an educational workshop coaches modulated the focus of these instructions from internal to external, indicating behaviour change and an opportunity to facilitate skill acquisition in soccer academy players

Balancing the dilution and oddity effects: Decisions depend on body size

Background Grouping behaviour, common across the animal kingdom, is known to reduce an individual's risk of predation; particularly through dilution of individual risk and predator confusion (predator inability to single out an individual for attack). Theory predicts greater risk of predation to individuals more conspicuous to predators by difference in appearance from the group (the ‘oddity’ effect). Thus, animals should choose group mates close in appearance to themselves (eg. similar size), whilst also choosing a large group. Methodology and Principal Findings We used the Trinidadian guppy (Poecilia reticulata), a well known model species of group-living freshwater fish, in a series of binary choice trials investigating the outcome of conflict between preferences for large and phenotypically matched groups along a predation risk gradient. We found body-size dependent differences in the resultant social decisions. Large fish preferred shoaling with size-matched individuals, while small fish demonstrated no preference. There was a trend towards reduced preferences for the matched shoal under increased predation risk. Small fish were more active than large fish, moving between shoals more frequently. Activity levels increased as predation risk decreased. We found no effect of unmatched shoal size on preferences or activity. Conclusions and Significance Our results suggest that predation risk and individual body size act together to influence shoaling decisions. Oddity was more important for large than small fish, reducing in importance at higher predation risks. Dilution was potentially of limited importance at these shoal sizes. Activity levels may relate to how much sampling of each shoal was needed by the test fish during decision making. Predation pressure may select for better decision makers to survive to larger size, or that older, larger fish have learned to make shoaling decisions more efficiently, and this, combined with their size relative to shoal-mates, and attractiveness as prey items influences shoaling decisions

Bridging the gap between science and application: the use of cocreation educational workshops in professional youth soccer

We examined whether practice activities adopted by professional youth soccer coaches are modulated through the implementation of and engagement with cocreative evidence-based programs. Across two experiments, we used systematic observation to identify the practice activities of seven coaches across 134 sessions. In Experiment A, drill-based and games-based activities were recorded and quantified. To encourage behaviour change across the study, the systematic observation data were compared with skill acquisition literature to provide coaches with quantitative feedback and recommendations during workshops. Postworkshop systematic observation data indicated that practice activities used by coaches changed in accordance with the evidenced-based information (increase in games-based activities) delivered within the workshop. Interview data indicated that coaches typically stated that the workshop was a key reason for behaviour change. In a follow-up Experiment B, feedback and recommendations were delivered using an interactive video-based workshop. The systematic observation data indicated that coaches increased the use of soccer activities that contained active decision making with coaches citing the workshop as a key reason for behaviour change. These findings indicate that coaching practice activities can be supported and shaped through the implementation of cocreated workshops wherein coaches collaborate with sport scientists and researchers to bridge the gap between science and application