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Correlative light, electron, and ion microscopy (CLEIM) offers huge potential to track the intracellular fate of antibiotics, with organelle-level resolution. However, a correlative approach that enables subcellular antibiotic visualisation in pathogen-infected tissue is lacking. Here, we developed correlative light, electron, and ion microscopy in tissue (CLEIMiT) and used it to identify the cell type-specific accumulation of an antibiotic in lung lesions of mice infected with Mycobacterium tuberculosis. Using CLEIMiT, we found that the anti-tuberculosis (TB) drug bedaquiline (BDQ) is localised not only in foamy macrophages in the lungs during infection but also accumulate in polymorphonuclear (PMN) cells.
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Pulmón/diagnóstico por imagen , Microscopía/métodos , Tuberculosis/diagnóstico por imagen , Animales , Antituberculosos , Diarilquinolinas/metabolismo , Diarilquinolinas/farmacología , Femenino , Pulmón/citología , Pulmón/microbiología , Masculino , Ratones , Ratones Endogámicos C3H , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica/métodos , Mycobacterium tuberculosis/patogenicidadRESUMEN
Background: Iron is a trace mineral that plays a significant role in oxygen transport and energy production during exercise. In deficiency, iron can have a significant negative impact on sports performance. Due to its relative simplicity, supplementation is a common treatment to combat deficiency. However, there is a paucity of analyses combining supplementation with dietary education as a method of treatment. Objective: To assess the effectiveness of a systematic iron intervention combining nutrition education and supplementation stages to combat low ferritin levels in collegiate runners. Methods: Twenty four distance runners (13 women; 11 men; 19.5 ± 0.8 years of age) were measured for serum ferritin, daily iron, calcium and vitamin C intake at the start of the fall semester and again after 100 days of supplementation. A dependent groups t-test was applied to delineate changes in Ferritin levels and iron, vitamin C and calcium intake. Alpha levels were maintained a priori at p < 0.05. Results: Ferritin levels averaged 40.0 ± 22.6â ng/mL in Fall and 33.7 ± 14.7â ng/mL in Spring. There were no statistical differences in ferritin levels from Fall to Spring (p = 0.074). Weekly Iron intake (# of foods) significantly increased from Fall (110.8 ± 43.1) to Spring (123.3 ± 43.9), (p = 0.028). There were no significant changes in Vitamin C or Calcium intake between time points (p = 0.441), (p = 0.901). Conclusion: We found no significant differences in serum ferritin measures but dietary intake of iron increased as a result of the intervention.
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ABSTRACT: Taylor, JB, Barnes, HC, Gombatto, SP, Greenwood, D, and Ford, KR. Quantifying external load and injury occurrence in women's collegiate volleyball players across a competitive season. J Strength Cond Res 36(3): 805-812, 2022-Volleyball demands repetitive jumping, with high loads linked to risk of injury. The purpose of this study was to examine jumping demands and injury patterns throughout a women's volleyball season. Sixteen Division-I female volleyball players wore an accelerometer to record jump count (JC) and jump height during every practice and match throughout the season. Physical health was documented using a weekly modified Oslo Sports Trauma Research Center Overuse Injury Questionnaire (OSLO) and time-loss injuries were recorded. Multivariate analyses of variance were used to compare measures across phases of the season, between types of session (practice vs. match), and between injured and noninjured players (α = 0.05). Results showed the greatest training demands in the preseason with larger jump counts than during the nonconference, conference schedule, and postseason schedules (p < 0.001). Performance increased throughout the season with greater jump heights in the nonconference and conference schedule than in the preseason (p = 0.01). There were no significant differences in JC between practices (65.5 ± 30.5) and matches (67.5 ± 46.4). An injury incidence of 5.49 injures per 1,000 athletic exposures was identified, with injuries accounting for 31 days lost, or 2.1% of total exposures. Injuries affected performance throughout the season, as noted by an average weekly OSLO score of 15.1 ± 13.9%. Injured players had significantly lower jump counts per exposure (p = 0.03) and a larger variation in training load than uninjured players (coefficient of variation: injured = 54%, uninjured = 41%; p = 0.006). These data help provide coaches and clinicians for training and rehabilitation program designs.
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Traumatismos en Atletas , Rendimiento Atlético , Voleibol , Traumatismos en Atletas/epidemiología , Traumatismos en Atletas/etiología , Femenino , Humanos , Estaciones del Año , UniversidadesRESUMEN
Coaches are an integral part of talent identification in sport and are often used as the "gold standard" against which scientific methods of talent identification are compared. However, their decision-making during this process is not well understood. In this article, we use an ecological approach to explore talent identification in combat sports. We interviewed twenty-four expert, international-level coaches from the Olympic disciplines of boxing, judo, and taekwondo (age: 48.7 + 7.5 years; experience: 20.8 + 8.3 years). Findings indicated that when coaches identify talent they rely on "gut instinct": intuitive judgements made without conscious thought, used to direct attention to particular athletes or characteristics. Our analysis revealed four major contributors to coaches' intuition: experiential knowledge, temporal factors, seeing athletes in context, and what can be worked with. Our findings demonstrate that i) athlete selections may be influenced by the coaches' perceived ability to improve certain athletes (rather than solely on athlete ability); and ii) "instinctual" decisions are the result of years of experience, time spent with the athlete, and the context surrounding the decision. Based on these findings, we recommend that future research focuses on the duration and conditions that are required for coaches to confidently and reliably identify talented athletes.
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Aptitud , Atletas , Rendimiento Atlético , Toma de Decisiones/fisiología , Instinto , Intuición/fisiología , Boxeo , Femenino , Humanos , Juicio/fisiología , Masculino , Artes Marciales , Persona de Mediana Edad , Investigación Cualitativa , Factores de TiempoRESUMEN
Bacterial nutrition is an essential aspect of host-pathogen interaction. For the intracellular pathogen Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis in humans, fatty acids derived from lipid droplets are considered the major carbon source. However, many other soluble nutrients are available inside host cells and may be used as alternative carbon sources. Lactate and pyruvate are abundant in human cells and fluids, particularly during inflammation. In this work, we study Mtb metabolism of lactate and pyruvate combining classic microbial physiology with a 'multi-omics' approach consisting of transposon-directed insertion site sequencing (TraDIS), RNA-seq transcriptomics, proteomics and stable isotopic labelling coupled with mass spectrometry-based metabolomics. We discovered that Mtb is well adapted to use both lactate and pyruvate and that their metabolism requires gluconeogenesis, valine metabolism, the Krebs cycle, the GABA shunt, the glyoxylate shunt and the methylcitrate cycle. The last two pathways are traditionally associated with fatty acid metabolism and, unexpectedly, we found that in Mtb the methylcitrate cycle operates in reverse, to allow optimal metabolism of lactate and pyruvate. Our findings reveal a novel function for the methylcitrate cycle as a direct route for the biosynthesis of propionyl-CoA, the essential precursor for the biosynthesis of the odd-chain fatty acids.
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Ácido Láctico/metabolismo , Mycobacterium tuberculosis/metabolismo , Ácido Pirúvico/metabolismo , Acilcoenzima A/metabolismo , Proteínas Bacterianas/metabolismo , Citrato (si)-Sintasa/metabolismo , Citratos/metabolismo , Ácidos Grasos/metabolismo , Regulación Bacteriana de la Expresión Génica/genética , Glioxilatos , Tuberculosis/microbiologíaRESUMEN
We investigated whether previously documented variation among populations in availability of dietary phosphorus (P) is linked to heterogeneity in growth rate of the New Zealand freshwater snail Potamopyrgus antipodarum on a P-limited diet. We chose this system because P. antipodarum inhabits water bodies that vary in P availability and because P. antipodarum growth rate varies considerably in response to low P. We quantified specific growth rate and alkaline phosphatase (AP) expression in a diverse array of juvenile P. antipodarum fed high vs. low-P diets. We found strong associations between P content of epilithon in the source lake and P. antipodarum growth rate on high vs. low-P diets, with snails collected from lakes with relatively low-P epilithon showing the greatest increase in growth rate on the high-P relative to low-P diet. We also found substantial intraspecific variation in growth response to P limitation. Expression of AP also varied among lineages and was negatively associated with C: P of lake epilithon but did not explain the relationship between C: P in the lake of origin and sensitivity to P limitation. Together, our results demonstrate a strong signature of the P environment in the lake of origin on how this snail responds to P limitation as well as preliminary evidence for intraspecific variation of AP expression in animals.
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Fósforo Dietético/administración & dosificación , Fósforo/química , Caracoles/fisiología , Animales , Dieta , Lagos/química , Nueva Zelanda , Fósforo Dietético/metabolismoRESUMEN
Coordination of dynamic interceptive movements is predicated on cyclical relations between an individual's actions and information sources from the performance environment. To identify dynamic informational constraints, which are interwoven with individual and task constraints, coaches' experiential knowledge provides a complementary source to support empirical understanding of performance in sport. In this study, 15 expert coaches from 3 sports (track and field, gymnastics and cricket) participated in a semi-structured interview process to identify potential informational constraints which they perceived to regulate action during run-up performance. Expert coaches' experiential knowledge revealed multiple information sources which may constrain performance adaptations in such locomotor pointing tasks. In addition to the locomotor pointing target, coaches' knowledge highlighted two other key informational constraints: vertical reference points located near the locomotor pointing target and a check mark located prior to the locomotor pointing target. This study highlights opportunities for broadening the understanding of perception and action coupling processes, and the identified information sources warrant further empirical investigation as potential constraints on athletic performance. Integration of experiential knowledge of expert coaches with theoretically driven empirical knowledge represents a promising avenue to drive future applied science research and pedagogical practice.
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Rendimiento Atlético/fisiología , Cognición , Movimiento/fisiología , Competencia Profesional , Desempeño Psicomotor/fisiología , Deportes/fisiología , Percepción Visual , Rendimiento Atlético/psicología , Femenino , Gimnasia , Humanos , Entrevistas como Asunto , Conocimiento , Masculino , Carrera , Deportes/estadística & datos numéricos , AtletismoRESUMEN
BACKGROUND: Pharmacists with additional clinical skills now work in UK emergency departments. Known as Emergency Department Pharmacist Practitioners, the role was developed in response to a shortage of physicians and nurses. They carry out activities typical of traditional hospital pharmacists, but also novel 'practitioner' activities such as examining patients, and acting as designated care provider. The role includes a responsibility to safeguard patients from harm. Professional competence, i.e. to safeguard patients, is underpinned by knowledge of the subject, but also knowledge application. AIM: To investigate what Emergency Department Pharmacist Practitioners know and understand about safeguarding vulnerable children and adults. METHOD: Thirteen Emergency Department Pharmacist Practitioners were interviewed to explore their knowledge and understanding of safeguarding. Interview questions were developed from review of relevant literature, as were vignettes with variables identified and altered to produce different scenarios. Template analysis was used to code data to a priori themes for each of the stages of the initial safeguarding process, and new themes that emerged throughout the process. RESULTS: Six themes were identified in addition to the four a priori themes. Overall, participants frequently described how safeguarding concerns are both recognised and responded to, but seemed more comfortable when responding to medicines related concerns. Factors thought to influence the safeguarding process included: resources and setting; and education, training and experiential learning; and culture. CONCLUSION: While Emergency Department Pharmacist Practitioners interviewed were aware of the safeguarding process, there were some misconceptions as to the roles of different healthcare workers in this process.
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Farmacéuticos , Médicos , Adulto , Niño , Humanos , Investigación Cualitativa , Servicio de Urgencia en Hospital , Competencia Clínica , Rol ProfesionalRESUMEN
Background: Readily accessible to the public, community pharmacies (CPs) were placed under increased pressure during the COVID-19 pandemic. In England, dispensing volume increased by 25% between February and March 2020. This followed a decade of stagnant government funding, which has been attributed to CP closures. If another pandemic emerged, the reduced number of CPs may face increased pressures. Objective: To explore CP service provision in England throughout the COVID-19 pandemic from the perspectives of providers and policy makers, including what can be learned in preparation for any future pandemic. Methods: CP providers (n = 10) and policy makers (n = 6) were interviewed via telephone between June and September 2021. Interviews were transcribed and then analysed thematically using NVivo. Results: Pandemic specific pressures were identified, as well as long-term issues which preceded the pandemic. Increased workload was recognised by both providers and policy makers due to changes in prescribing habits and was exacerbated by staff shortages. CP staff safety was a major concern, with limited personal protective equipment provided despite being open to the public. General Practitioner (GP) surgeries received more protective equipment than CP and still referred patients to pharmacy e.g., for a blood pressure check. Conclusions: The pandemic re-confirmed CPs role of providing accessible healthcare, particularly medicines provision, but also highlighted the demand for in-person clinical services. Improved communication channels between CP and GP surgeries are required, as is pandemic prescribing guidance to ensure appropriate prescribing to safeguard the medicines supply chain. To ensure the health of all providers is fairly protected, activities which require in-person contact or can be undertaken remotely by CP, GP surgeries and other providers should be reviewed. For pandemic preparation, legislative changes are required which empower pharmacy to fully contribute to patient care. A review of pharmacy funding and staffing is also needed to ensure services are sustainable.
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Purpose: This study assessed the effects of footwear longitudinal bending stiffness on running economy and biomechanics of rearfoot striking older runners. Methods: Nine runners over 60 years of age completed two running bouts at their preferred running pace in each of three footwear conditions: low (4.4 ± 1.8 N·m-1), moderate (5.7 ± 1.7 N·m-1), and high (6.4 ± 1.6 N·m-1) bending stiffness. Testing order was randomized and a mirror protocol was used (i.e., A,B,C,C,B,A). Expired gases, lower limb kinematics, and ground reaction forces were collected simultaneously and lower limb joint kinetics, running economy (i.e., VO2), leg stiffness, and spatio-temporal variables were calculated. Results: Running economy was not different among stiffness conditions (p = 0.60, p = 0.53 [mass adjusted]). Greater footwear stiffness reduced step length (p = 0.046) and increased peak vertical ground reaction force (p = 0.019) but did not change peak ankle plantarflexor torque (p = 0.65), peak positive ankle power (p = 0.48), ankle positive work (p = 0.86), propulsive force (p = 0.081), and leg stiffness (p = 0.46). Moderate footwear stiffness yielded greater peak negative knee power compared to low (p = 0.04) and high (p = 0.03) stiffness. Conclusions: These novel findings demonstrate that increasing footwear longitudinal bending stiffness using flat carbon fiber inserts does not improve running economy and generally does not alter lower limb joint mechanics of rearfoot strike runners over 60 years. Future studies should investigate how other footwear characteristics (e.g., midsole material, plate location, and sole curvature) influence economy and biomechanics in this population.
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Carrera , Zapatos , Humanos , Persona de Mediana Edad , Anciano , Fenómenos Biomecánicos , Pie , Extremidad InferiorRESUMEN
Objective: The female breast is a passive tissue with little intrinsic support. Therefore, women rely on external breast support (sports bras) to control breast motion during athletic tasks. Research has demonstrated that lower levels of breast support are associated with altered trunk and pelvis movement patterns during running, a common athletic task. However, no previous study has identified the effect of sports bra support on movement patterns during other athletic tasks including landing. Therefore, the purpose of this study was to examine the effects of breast support on trunk and knee joint biomechanics in female collegiate athletes during a double-leg landing task. Methods: Fourteen female collegiate athletes completed five double-leg landing trials in each of three different sports bra conditions: no support, low support, and high support. A 10-camera motion capture system (250 Hz, Qualisys, Goteburg, Sweden) and two force platforms (1,250 Hz, AMTI, Watertown, MA, USA) were used to collect three-dimensional kinematics and ground reaction forces simultaneously. Visual 3D was used to calculate trunk segment and knee joint angles and moments. Custom software (MATLAB 2021a) was used to determine discrete values of dependent variables including vertical breast displacement, knee joint and trunk segment angles at initial contact and 100 ms post-initial contact, and peak knee joint moments. A repeated measures analysis of covariance with post-hoc paired samples t-tests were used to evaluate the effect of breast support on landing biomechanics. Results: Increasing levels of breast support were associated with reductions in peak knee flexion (Right: p = 0.008; Left: p = 0.029) and peak knee valgus angles (Right: p = 0.011; Left: p = 0.003) as well as reductions in peak knee valgus moments (Right: p = 0.033; Left: p = 0.013). There were no changes in peak knee extension moments (Right: p = 0.216; Left: p = 0.261). Increasing levels of breast support were associated with greater trunk flexion angles at initial contact (p = 0.024) and greater peak trunk flexion angles (p = 0.002). Conclusions: Lower levels of breast support are associated with knee joint and trunk biomechanical profiles suggested to increase ACL injury risk.
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Understanding how individuals navigate challenging accuracy demands required to register a legal jump is important in furthering knowledge of competitive long jumping. Identification of co-ordination tendencies unique to each individual emphasises the need to examine the presence of unique movement solutions and presents important information for individualisation of training environments. In this study, key measures of gait were recorded during the long jump run-ups of 8 athletes at 8 national level competitions in the 2015 and 2016 Australian track and field seasons. These gait measures were examined to identify whether different visual regulation strategies emerged for legal and foul jumps for each competitor. Emergence of different footfall variability data curves, illustrating how step adjustments were distributed across the run-up for each athlete, suggests that athletes interacted differently with features of the competition environment. This observation highlights the importance of movement adaptability as constraints change and emerge across each performance trial. Results provided further support in conceptualising the run-up as a continuous interceptive action task consisting of a series of interconnected events (i.e., individual step lengths) influencing the regulation of gait towards the take-off board. This information can be used by coaches and practitioners in designing training environments that promote athlete adaptation of more functional movement solutions closely matched to the dynamics of competition environments. Results suggest that training designs that help athletes to search, explore and exploit key sources of information from the competition environment will enhance the fit between the individual and the environment and the development of rich, adaptable movement solutions for competitive performance.
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Atletas , Marcha/fisiología , Movimiento , Carrera/fisiología , Atletismo , Adaptación Fisiológica , Adulto , Australia , Femenino , Humanos , Conocimiento , Masculino , Práctica Psicológica , Adulto JovenRESUMEN
To be effective, chemotherapy against tuberculosis (TB) must kill the intracellular population of the pathogen, Mycobacterium tuberculosis. However, how host cell microenvironments affect antibiotic accumulation and efficacy remains unclear. Here, we use correlative light, electron, and ion microscopy to investigate how various microenvironments within human macrophages affect the activity of pyrazinamide (PZA), a key antibiotic against TB. We show that PZA accumulates heterogeneously among individual bacteria in multiple host cell environments. Crucially, PZA accumulation and efficacy is maximal within acidified phagosomes. Bedaquiline, another antibiotic commonly used in combined TB therapy, enhances PZA accumulation via a host cell-mediated mechanism. Thus, intracellular localisation and specific microenvironments affect PZA accumulation and efficacy. Our results may explain the potent in vivo efficacy of PZA, compared to its modest in vitro activity, and its critical contribution to TB combination chemotherapy.
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Antituberculosos/farmacología , Citosol/microbiología , Mycobacterium tuberculosis/efectos de los fármacos , Pirazinamida/farmacología , Antituberculosos/farmacocinética , Diarilquinolinas/farmacocinética , Diarilquinolinas/farmacología , Sinergismo Farmacológico , Humanos , Concentración de Iones de Hidrógeno , Macrófagos/microbiología , Microscopía Electrónica , Mutación , Mycobacterium tuberculosis/crecimiento & desarrollo , Mycobacterium tuberculosis/metabolismo , Pirazinamida/farmacocinética , Sistemas de Secreción Tipo VII/genéticaRESUMEN
BACKGROUND: Emergency Department Pharmacist Practitioners (EDPPs) undertake both 'traditional' clinical pharmacy work, e.g. check prescriptions, and 'practitioner' work, e.g. perform clinical examinations. A recent study found a large variation in the extent and type of care provided. Whilst variation allows services to be tailored to local needs, it is important that care meets the minimum standards that are safe, effective, patient-centred, timely, efficient, and equitable. OBJECTIVE(S): To develop an EDPP service specification based on views of professional and patient stakeholders, primarily to support providers with delivery of high quality services. METHODS: Patients, ED pharmacists and other ED healthcare professionals developed standards guided by the Institute of Medicine's quality domains. A panel of six ED pharmacists suggested and agreed on themes that should be included in the service specification. Additional themes were identified through interviews with eight patients who had been cared for by EDPPs as to their expectations of the service. Finally, a multidisciplinary expert panel of healthcare professionals and researchers reviewed and refined the service specification. RESULTS: ED pharmacists developed 36 themes with consensus achieved for 25. Additional themes from the patient interviews concerned the communication and behaviour of EDPPs rather than specific clinical activities undertaken. Whilst patients were happy to be cared for by an EDPP working within their competence, for certain conditions (e.g. major trauma) they wanted a doctor as their main care provider. An evidence-based EDPP service specification of 52 criteria grouped into 4 categories was produced: direct patient care (29); other activities (10); general approach (10); and service structures (3). CONCLUSIONS: As the product of both patient and expert input, EDs could align existing or newly developed services to the specification. Whether or not the specification actually improves the quality of EDPP services requires investigation, as does the absolute quality impact of services.
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A typical assumption found in talent identification literature is that different coaches, given the same athletes and circumstances, will identify the same subset of athletes as "talented". However, while coaches play a major role during talent identification in practical sport settings, there is limited empirical research exploring the processes which underpin this. The purpose of this study was to explore the reliability of "the coach's eye" during the assessment of talent in a group of athletes. Specifically, this project compared inter-coach agreement between nine judo coaches (ages 35.8 ± 10.6 years) with varying levels of experience (12.9 ± 8.9 years) in the evaluation of 24 talented cadet judo athletes (13-15 years) at seven timepoints throughout a 4-day development training camp. Without discussion of their scores with other coaches, coaches provided a single score representing each athlete's "potential for future performance" on an 11-point Likert scale at each timepoint. Scores from each coach were converted into rankings from 1 to 24 to create a normalized scale to facilitate comparison of athletes. Based on their rankings at each timepoint, athletes were placed into one of three evenly distributed groups (high, medium, and low rank). Inter-coach agreement at each timepoint was determined by the number of coaches who ranked each athlete in the same group, categorized at three levels: 50, 75 or 100% agreement. Overall results showed that at completion of the camp, coaches reached 100% agreement on only two athletes, both of whom were in the high rank group. When inter-coach agreement was set at 50%, 15 athletes (62.5%) were placed into like groups. The first timepoint at which coaches were able to differentiate between the majority of athletes was Timepoint 3 (end of day 2). The findings suggest that, in isolation, coaches do not agree on the talent or potential of athletes. This indicates that the "coach's eye" is subjective and variable, and, given the same context, there is poor inter-coach agreement in the identification of talented athletes. In turn, these findings may have significant implications for both future talent identification research and athlete selection processes by sport organizations.
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The current study used a complex, sport-specific movement skill to explore the effects of a win-shift/lose-stay practice schedule on learning and compared its effectiveness with that of blocked and random practice schedules. Thirty-six adults (24.9 ± 3.3 years) were assigned to blocked, random and learner-adapted training groups. Each participant performed 360 trials of the basketball set shot from multiple locations across six practice sessions. For the learner-adapted group, switching between task variations was performance-contingent; switching between shooting locations occurred only following a successful shot. Shooting success was calculated as the percentage of successful shots performed, and measured during pre-acquisition (i.e. baseline), acquisition (i.e. practice) and post-acquisition (i.e. retention and transfer). Despite scoring less shots throughout practice compared to baseline testing, the learner-adapted group showed a significant improvement for shooting success in transfer (d = 1.02). Blocked practice demonstrated significant improvements for shooting success in immediate retention (d = 1.83), delayed retention (d = 1.69) and transfer (d = 1.39). Random practice significantly improved shooting success in both immediate (d = 1.03) and delayed retention (d = 0.81). The current findings highlight that performance during practice does not necessarily represent the permanency and adaptability of skill learning. The implications of the findings and their practical applications are discussed in the context of practice scheduling during learning of a sports skill.
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Baloncesto , Aprendizaje , Destreza Motora , Práctica Psicológica , Desempeño Psicomotor , Retención en Psicología , Adulto , Femenino , Humanos , MasculinoRESUMEN
The dilution effect can occur by a range of mechanisms and results in reduced parasite prevalence in host taxa. In invaded ecosystems, the dilution effect can benefit native species if non-native species, acting as resistant or less competent hosts, reduce rates of parasitic infections in native species. In field experiments, we assessed whether manipulating biomass of the non-native snail, Potamopyrgus antipodarum, caused a dilution effect by reducing trematode infections in three taxa of native snails. In contrast to many studies showing resistant or less competent non-native hosts can "dilute" or reduce infection rates, we found no evidence for a dilution effect reducing infection rates of any of the native snails. We suggest that a dilution effect may not have occurred because most trematode taxa are highly host specific, and thus the trematode transmission stages did not recognize the invasive snail as a possible host. In this case, community composition appears to be important in influencing the dilution effect.
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Especies Introducidas , Caracoles , Animales , Biodiversidad , Dinámica Poblacional , Caracoles/parasitología , Trematodos , Infecciones por Trematodos/veterinaria , WyomingRESUMEN
The ability of Mycobacterium tuberculosis to form serpentine cords is intrinsically related to its virulence, but specifically how M. tuberculosis cording contributes to pathogenesis remains obscure. Here, we show that several M. tuberculosis clinical isolates form intracellular cords in primary human lymphatic endothelial cells (hLECs) in vitro and in the lymph nodes of patients with tuberculosis. We identified via RNA-Seq a transcriptional program that activated, in infected-hLECs, cell survival and cytosolic surveillance of pathogens pathways. Consistent with this, cytosolic access was required for intracellular M. tuberculosis cording. Mycobacteria lacking ESX-1 type VII secretion system or phthiocerol dimycocerosates expression, which failed to access the cytosol, were indeed unable to form cords within hLECs. Finally, we show that M. tuberculosis cording is a size-dependent mechanism used by the pathogen to avoid its recognition by cytosolic sensors and evade either resting or IFN-γ-induced hLEC immunity. These results explain the long-standing association between M. tuberculosis cording and virulence and how virulent mycobacteria use intracellular cording as strategy to successfully adapt and persist in the lymphatic tracts.
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Antígenos Bacterianos , Proteínas Bacterianas , Células Endoteliales , Evasión Inmune , Mycobacterium tuberculosis , Tuberculosis , Factores de Virulencia , Antígenos Bacterianos/genética , Antígenos Bacterianos/inmunología , Proteínas Bacterianas/genética , Proteínas Bacterianas/inmunología , Células Cultivadas , Células Endoteliales/inmunología , Células Endoteliales/microbiología , Células Endoteliales/patología , Humanos , Interferón gamma/genética , Interferón gamma/inmunología , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/inmunología , Mycobacterium tuberculosis/patogenicidad , RNA-Seq , Tuberculosis/genética , Tuberculosis/inmunología , Tuberculosis/patología , Factores de Virulencia/genética , Factores de Virulencia/inmunologíaRESUMEN
Analysing performance in competitive environments enables identification of key constraints which shape behaviours, supporting designs of more representative training and learning environments. In this study, competitive performance of 244 elite level jumpers (male and female) was analysed to identify the impact of candidate individual, environmental and task constraints on performance outcomes. Findings suggested that key constraints shaping behaviours in long jumping were related to: individuals (e.g. particularly intended performance goals of athletes and their impact on future jump performance); performance environments (e.g. strength and direction of wind) and tasks (e.g. requirement for front foot to be behind foul line at take-off board to avoid a foul jump). Results revealed the interconnectedness of competitive performance, highlighting that each jump should not be viewed as a behaviour in isolation, but rather as part of a complex system of connected performance events which contribute to achievement of competitive outcomes. These findings highlight the potential nature of the contribution of performance analysis in competitive performance contexts. They suggest how practitioners could design better training tasks, based on key ecological constraints of competition, to provide athletes with opportunities to explore and exploit functional intentions and movement solutions high in contextual specificity.
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Rendimiento Atlético/fisiología , Conducta Competitiva/fisiología , Análisis y Desempeño de Tareas , Atletismo/fisiología , Adulto , Femenino , Humanos , MasculinoRESUMEN
OBJECTIVES: Talent identification traditionally relies on the knowledge and perceptions of expert coaches to identify and predict potential future elite athletes. Experiential coach knowledge is a valuable source of information to guide research in this ill-defined and under-researched area. This review aims to synthesize current empirical understanding of coach knowledge as it relates to decision making in talent identification. DESIGN: This systematic review and meta-synthesis used the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify relevant literature. METHODS: Eligible studies were critically appraised for quality, and key findings from the 14 studies were integrated to allow for thematic analysis. RESULTS: The meta-synthesis revealed the key theme of 'instinct' as the primary contributor to coach decisions during talent identification. Subordinate themes informing coach instinct were 'drive and ambition', 'game intelligence' and 'physical and technical skills'. CONCLUSIONS: Coaches appear to make decisions about talent based on their tacit knowledge or instinct. Understanding how coaches develop these instinctual 'feelings' may guide future research into talent identification and enhance our understanding of how experiential coach knowledge is developed and utilised in the daily training environment.