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1.
New Phytol ; 242(1): 93-106, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38375897

RESUMEN

Serotiny is an adaptive trait that allows certain woody plants to persist in stand-replacing fire regimes. However, the mechanisms by which serotinous cones avoid seed necrosis and nonserotinous species persist in landscapes with short fire cycles and serotinous competitors remain poorly understood. To investigate whether ovulate cone traits that enhance seed survival differ between serotinous and nonserotinous species, we examined cone traits in 24 species within Pinaceae and Cupressaceae based on physical measurements and cone heating simulations using a computational fluid dynamics model. Fire-relevant cone traits were largely similar between cone types; those that differed (e.g. density and moisture) conferred little seed survival advantage under simulated fire. The most important traits influencing seed survival were cone size and seed depth within the cone, which was found to be an allometric function of cone mass for both cone types. Thus, nonserotinous cones should not suffer significantly greater seed necrosis than serotinous cones of equal size. Closed nonserotinous cones containing mature seeds may achieve substantial regeneration after fire if they are sufficiently large relative to fire duration and temperature. To our knowledge, this is the most comprehensive study of the effects of fire-relevant cone traits on conifer regeneration supported by physics-based fire simulation.


Asunto(s)
Incendios , Tracheophyta , Semillas , Fenotipo , Necrosis
2.
Proc Natl Acad Sci U S A ; 118(45)2021 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-34697246

RESUMEN

Intensifying wildfire activity and climate change can drive rapid forest compositional shifts. In boreal North America, black spruce shapes forest flammability and depends on fire for regeneration. This relationship has helped black spruce maintain its dominance through much of the Holocene. However, with climate change and more frequent and severe fires, shifts away from black spruce dominance to broadleaf or pine species are emerging, with implications for ecosystem functions including carbon sequestration, water and energy fluxes, and wildlife habitat. Here, we predict that such reductions in black spruce after fire may already be widespread given current trends in climate and fire. To test this, we synthesize data from 1,538 field sites across boreal North America to evaluate compositional changes in tree species following 58 recent fires (1989 to 2014). While black spruce was resilient following most fires (62%), loss of resilience was common, and spruce regeneration failed completely in 18% of 1,140 black spruce sites. In contrast, postfire regeneration never failed in forests dominated by jack pine, which also possesses an aerial seed bank, or broad-leaved trees. More complete combustion of the soil organic layer, which often occurs in better-drained landscape positions and in dryer duff, promoted compositional changes throughout boreal North America. Forests in western North America, however, were more vulnerable to change due to greater long-term climate moisture deficits. While we find considerable remaining resilience in black spruce forests, predicted increases in climate moisture deficits and fire activity will erode this resilience, pushing the system toward a tipping point that has not been crossed in several thousand years.


Asunto(s)
Cambio Climático , Picea , Taiga , Incendios Forestales , América del Norte
3.
Lupus ; 32(4): 508-520, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36803286

RESUMEN

OBJECTIVES: To explore the feasibility and effectiveness of telehealth-supervised exercise for adults with Systemic lupus erythematosus (SLE). METHODS: This was a non-randomised controlled pilot trial comparing telehealth-supervised exercise (8 weeks, 2 days/week, 45 min, moderate intensity) plus usual care with usual care alone. Mixed methods were used to assess change in fatigue (FACIT-fatigue), quality of life (SF36), resting fatigue and pain (11-point scale), lower body strength (five-time sit-to-stand) and endurance (30 s sit-to-stand), upper body endurance (30 s arm curl), aerobic capacity (2 min step test), and experience (survey and interviews). Group comparison was performed statistically using a two-sample T-test or Mann-Whitney U-test. Where known, we used MCID or MCII, or assumed a change of 10%, to determine clinically meaningful change within groups over time. Interviews were analysed using reflexive thematic analysis. RESULTS: Fifteen female adults with SLE were included (control group n = 7, exercise group n = 8). Statistically significant differences between groups, in favour of the exercise intervention, were noted for SF36 domain emotional well-being (p = 0.048) and resting fatigue (p = 0.012). There were clinically meaningful improvements over time for FACIT-fatigue (+6.3 ± 8.3, MCID >5.9), SF36 domains physical role functioning (+30%), emotional role functioning (+55%), energy/fatigue (+26%), emotional well-being (+19%), social functioning (+30%), resting pain (-32%), and upper body endurance (+23%) within the exercise group. Exercise attendance was high (98%, 110/112 sessions); participants strongly agreed (n = 5/7, 71%) or agreed (n = 2/7, 29%) they would do telehealth-supervised exercise again and were satisfied with the experience. Four themes emerged: (1) ease and efficiency of exercising from home, (2) value of live exercise instruction, (3) challenges of exercising at home, and (4) continuation of telehealth-supervised exercise sessions. CONCLUSION: Key findings from this mixed-method investigation suggest that telehealth-supervised exercise was feasible for, and well-accepted by, adults with SLE and resulted in some modest health improvements. We recommend a follow-up RCT with more SLE participants.


Asunto(s)
Lupus Eritematoso Sistémico , Telemedicina , Adulto , Humanos , Femenino , Proyectos Piloto , Calidad de Vida , Lupus Eritematoso Sistémico/terapia , Lupus Eritematoso Sistémico/psicología , Terapia por Ejercicio/métodos , Fatiga/etiología , Fatiga/psicología , Dolor
4.
Cochrane Database Syst Rev ; 4: CD014816, 2023 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-37073886

RESUMEN

BACKGROUND: Systemic lupus erythematosus (SLE) is a rare, chronic autoimmune inflammatory disease with a prevalence varying from 4.3 to 150 people in 100,000, or approximately five million people worldwide. Systemic manifestations frequently include internal organ involvement, a characteristic malar rash on the face, pain in joints and muscles, and profound fatigue. Exercise is purported to be beneficial for people with SLE. For this review, we focused on studies that examined all types of structured exercise as an adjunctive therapy in the management of SLE. OBJECTIVES: To evaluate the benefits and harms of structured exercise as adjunctive therapy for adults with SLE compared with usual pharmacological care, usual pharmacological care plus placebo and usual pharmacological care plus non-pharmacological care. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 30 March 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of exercise as an adjunct to usual pharmacological treatment in SLE compared with placebo, usual pharmacological care alone and another non-pharmacological treatment. Major outcomes were fatigue, functional capacity, disease activity, quality of life, pain, serious adverse events, and withdrawals due to any reason, including any adverse events. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our major outcomes were 1. fatigue, 2. functional capacity, 3. disease activity, 4. quality of life, 5. pain, 6. serious adverse events, and 7. withdrawals due to any reason. Our minor outcomes were 8. responder rate, 9. aerobic fitness, 10. depression, and 11. anxiety. We used GRADE to assess certainty of evidence. The primary comparison was exercise compared with placebo. MAIN RESULTS: We included 13 studies (540 participants) in this review. Studies compared exercise as an adjunct to usual pharmacological care (antimalarials, immunosuppressants, and oral glucocorticoids) with usual pharmacological care plus placebo (one study); usual pharmacological care (six studies); and another non-pharmacological treatment such as relaxation therapy (seven studies). Most studies had selection bias, and all studies had performance and detection bias. We downgraded the evidence for all comparisons because of a high risk of bias and imprecision. Exercise plus usual pharmacological care versus placebo plus usual pharmacological care Evidence from a single small study (17 participants) that compared whole body vibration exercise to whole body placebo vibration exercise (vibrations switched off) indicated that exercise may have little to no effect on fatigue, functional capacity, and pain (low-certainty evidence). We are uncertain whether exercise results in fewer or more withdrawals (very low-certainty evidence). The study did not report disease activity, quality of life, and serious adverse events. The study measured fatigue using the self-reported Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-Fatigue), scale 0 to 52; lower score means less fatigue. People who did not exercise rated their fatigue at 38 points and those who did exercise rated their fatigue at 33 points (mean difference (MD) 5 points lower, 95% confidence interval (CI) 13.29 lower to 3.29 higher). The study measured functional capacity using the self-reported 36-item Short Form health questionnaire (SF-36) Physical Function domain, scale 0 to 100; higher score means better function. People who did not exercise rated their functional capacity at 70 points and those who did exercise rated their functional capacity at 67.5 points (MD 2.5 points lower, 95% CI 23.78 lower to 18.78 higher). The study measured pain using the SF-36 Pain domain, scale 0 to 100; lower scores mean less pain. People who did not exercise rated their pain at 43 points and those who did exercise rated their pain at 34 points (MD 9 points lower, 95% CI 28.88 lower to 10.88 higher). More participants from the exercise group (3/11, 27%) withdrew from the study than the placebo group (1/10, 10%) (risk ratio (RR) 2.73, 95% CI 0.34 to 22.16). Exercise plus usual pharmacological care versus usual pharmacological care alone The addition of exercise to usual pharmacological care may have little to no effect on fatigue, functional capacity, and disease activity (low-certainty evidence). We are uncertain whether the addition of exercise improves pain (very low-certainty evidence), or results in fewer or more withdrawals (very low-certainty evidence). Serious adverse events and quality of life were not reported. Exercise plus usual care versus another non-pharmacological intervention such as receiving information about the disease or relaxation therapy Compared with education or relaxation therapy, exercise may reduce fatigue slightly (low-certainty evidence), may improve functional capacity (low-certainty evidence), probably results in little to no difference in disease activity (moderate-certainty evidence), and may result in little to no difference in pain (low-certainty evidence). We are uncertain whether exercise results in fewer or more withdrawals (very low-certainty evidence). Quality of life and serious adverse events were not reported. AUTHORS' CONCLUSIONS: Due to low- to very low-certainty evidence, we are not confident on the benefits of exercise on fatigue, functional capacity, disease activity, and pain, compared with placebo, usual care, or advice and relaxation therapy. Harms data were not well reported.


Asunto(s)
Ejercicio Físico , Lupus Eritematoso Sistémico , Adulto , Humanos , Fatiga/etiología , Fatiga/terapia , Terapia por Ejercicio/métodos , Dolor , Lupus Eritematoso Sistémico/terapia , Lupus Eritematoso Sistémico/complicaciones , Calidad de Vida
5.
Glob Chang Biol ; 28(9): 3066-3082, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35170154

RESUMEN

Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long-lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time-series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population-level time-series from 974 species in 66 countries. The mean and median time-series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well-studied species, MASTREE+ includes extensive replication of time-series across geographical and climatic gradients. Here we describe the open-access data set, available as a.csv file, and we introduce an associated web-based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long-lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics.


Aún existen importantes vacíos en la comprensión de la respuesta reproductiva de las plantas al cambio medioambiental, en parte, porque su monitoreo en especies de plantas longevas requiere una observación directa durante muchos años, y estos conjuntos de datos rara vez han estado disponibles. Aquí presentamos a MASTREE +, una base de datos que recopila series de tiempo de la reproducción de las plantas de todo el planeta, poniendo a disposición estos datos de libre acceso para la comunidad científica. MASTREE + incluye 73.828 puntos de observación de la reproducción anual georreferenciados (ej. conteos de semillas y frutos) en poblaciones de plantas perennes en todo el mundo. Estas observaciones consisten en 5971 series temporales a nivel de población provenientes de 974 especies en 66 países. La mediana de la duración de las series de tiempo es de 10 años (media = 12.4 años) y el conjunto de datos incluye 1.122 series de al menos dos décadas (≥20 años de observaciones). Para un subconjunto de especies bien estudiadas, MASTREE +incluye un amplio conjunto de series temporales replicadas en gradientes geográficos y climáticos. Describimos el conjunto de datos de acceso abierto disponible como un archivo.csv y presentamos una aplicación web asociada para la exploración de datos. MASTREE+ proporcionará la base para mejorar la comprensión sobre la respuesta reproductiva de plantas longevas al cambio medioambiental. Además, MASTREE+ facilitará los avances en la investigación de la ecología y la evolución de las estrategias reproductivas en plantas perennes y el papel de la reproducción vegetal como determinante de la dinámica de ecosistemas.


Asunto(s)
Ecosistema , Reproducción , Ecología , Plantas , Semillas/fisiología
6.
J Clin Densitom ; 23(2): 254-263, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-30076009

RESUMEN

The effectiveness of structured multidisciplinary weight loss (WL) programs combining nutrition and physical activity on bone geometry and strength remains uncertain in adolescents with obesity. The study investigated the impact of a structured WL intervention on bone geometry and strength in adolescents with obesity. Thirty-one adolescents with obesity (mean [standard deviation] 13.61 [1.27] yr, body mass index Z-score 2.26 [0.30]) experienced an 8-mo WL program. A group of 23 maturation-matched controls (mean [standard deviation] 15.90 [0.43] yr, body mass index Z-score -0.12 [0.48]) were recruited for calculating Z-scores. Body composition, bone density, geometry, and mechanical properties were assessed using dual-energy X-ray absorptiometry and dual-energy X-ray absorptiometry-derived hip structural analysis. Plasma concentration of leptin, estradiol, collagen type 1 cross-linked C-telopeptide (CTx), and procollagen type 1 N-terminal propeptide were measured. Longitudinal analysis showed that adolescents with obesity reduced body weight and fat mass (total [g, %; p < 0.007]). After 8 mo, body mineral density at total body less head (Δ 3.22 [3.58] % p < 0.001) and lumbar spine (Δ 3.67 [4.04] % p < 0.001) increased. At the narrow neck (NN) of the femur, lower body mineral density (Δ -7.19 [8.79] % p < 0.001) and higher endocortical diameter and width were observed (NN endocortical diameter Δ 2.85 [0.26] %, NN width Δ 5.48 [10.84] %, respectively). An increased buckling ratio (Δ 8.24 [2.00] % p = 0.005) was also evident. Similar concentration of procollagen type 1 N-terminal propeptide and CTx was seen from baseline to 8 mo. However, at 4 mo, lower CTx levels were observed. The 8-mo WL program was associated with some positive adaptations among bone density parameters for the whole body and spine. However, bone geometry and strength estimates appeared to weaken at the NN. Clinically, the buckling ratio score at the NN was close to the fracture threshold. An "androgynous-like" adaptation was observed with bone geometry changes demonstrating periosteal expansion and endocortical resorption.


Asunto(s)
Huesos/anatomía & histología , Huesos/fisiología , Dieta Reductora , Terapia por Ejercicio , Obesidad Infantil/fisiopatología , Obesidad Infantil/terapia , Adolescente , Biomarcadores/sangre , Composición Corporal , Densidad Ósea , Femenino , Humanos , Masculino , Obesidad Infantil/sangre , Pérdida de Peso
7.
Diabetes Spectr ; 33(2): 175-181, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32425455

RESUMEN

Diabetes can take a tremendous toll on physical and psychological health. Given the growing evidence of the benefits of humor, this study examined the association between diabetes and humor. The sample consisted of 249 participants: 72.3% with type 1 diabetes, 70.3% female, 89.5% Caucasian, and 70.9% college educated. Participants completed the Humor Styles Questionnaire (HSQ) and were compared with HSQ norms. On the affiliative humor scale, the diabetes group did not differ from the norm (P >0.05), nor did those with type 1 diabetes (P >0.05). Scores of those with type 2 diabetes were lower than the norm (P <0.05). On the self-enhancing humor scale, the diabetes group did not differ from the norm (P >0.05), nor did the subgroups with type 1 diabetes (P >0.05) or type 2 diabetes (P >0.05). The diabetes group was lower than the norm on aggressive humor (P <0.01), as were the subgroups with type 1 diabetes (P <0.01) and type 2 diabetes (P <0.05). The diabetes group was higher than the norm on self-defeating humor (P <0.01), as were the subgroups with type 1 diabetes (P <0.01) and type 2 diabetes (P <0.01). Results suggest that people with either type of diabetes are more inclined toward self-enhancing humor, are less inclined toward aggressive humor, and score higher on self-defeating humor, and those with type 1 diabetes are also inclined toward affiliative humor. Results are discussed relative to the sample being comprised of individuals with good glycemic control (mean A1C 7.06 ± 1.39%). This study offers a preliminary comparison of humor among people with diabetes versus those in a healthy norm group without diabetes.

8.
Am J Bot ; 106(12): 1566-1574, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31769003

RESUMEN

PREMISE: Dispersal capacity primarily determines the spatial establishment patterns that drive range expansions and contractions in tree species. Seedling establishment in Baker cypress (Hesperocyparis bakeri [(Jeps.) Bartel]) relies predominantly on fire events, due to its cone serotiny, shade intolerance, and small seeds that require the optimal conditions of fire-exposed, mineral soil seedbeds. METHODS: We quantified the density and spatial distribution of post-disturbance seedlings following the 2014 Eiler Fire in northern California and compared the observed recruitment to predictions from a mechanistic seed dispersal model. RESULTS: Postfire recruitment was dense, averaging 11 seedlings/m2 , and occurred primarily in the first year after fire. We estimated the mean descent velocity of the wingless seeds as ~4 m/s, the highest value reported for any putatively wind-dispersed tree species. The rapid seed descent contributed to markedly spatially constrained recruitment. Most seedlings (~81%) established within 5 m of the parent tree, and 94% established within 10 m. The maximum observed dispersal distance was 48.5 m; dispersal distance scaled linearly with canopy height. Distributions of modeled seed dispersal distance and observed seedling establishment in Baker cypress did not differ, demonstrating that wind disperses seeds a short distance because of the lack of a wing, and secondary dispersal appeared to be minimal at this recently burned site. CONCLUSIONS: If seed dispersal is solely reliant on wind, migration in response to rapid climate change will be impeded and potentially present difficulties in sustaining populations of this and other obligate seeder species with equally constrained dispersal.


Asunto(s)
Cupressus , Dispersión de Semillas , Tracheophyta , Animales , California , Plantones , Semillas , Árboles
9.
J Bone Miner Metab ; 36(1): 12-30, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28779404

RESUMEN

Given the rise in pediatric obesity, clarifications on the relationship between obesity and bone health and on the impact of structured intervention on this relationship are needed. This systematic review and meta-analysis investigated the effect of obesity on bone health and assessed the effect of structured intervention in children and adolescents with obesity. Medline complete, OVID, CINAHL, EMBASE and PubMed databases were searched for studies on obesity and bone health variables up to September 2016, then an update occurred in March 2016. Search items included obesity, childhood, dual energy X-ray absorptiometry and peripheral quantitative computed tomography. Twenty-three studies (14 cross-sectional and nine longitudinal) matched the inclusion criteria. Results from the meta-analysis (cross-sectional studies) confirmed that children and adolescents with obesity have higher bone content and density than their normal weight peers. Results from longitudinal studies remain inconclusive as only 50% of the included studies reported a positive effect of a structured intervention program on bone health. As such, the meta-analysis reported that structured intervention did not influence bone markers despite having beneficial effects on general health in youth with obesity.


Asunto(s)
Huesos/fisiopatología , Ejercicio Físico , Obesidad Infantil/fisiopatología , Absorciometría de Fotón , Adolescente , Huesos/diagnóstico por imagen , Niño , Estudios Transversales , Femenino , Humanos , Estudios Longitudinales , Masculino , Análisis de Regresión
10.
J Strength Cond Res ; 32(12): 3373-3382, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30335720

RESUMEN

Greene, DA, Varley, BJ, Hartwig, TB, Chapman, P, and Rigney, M. A low-carbohydrate ketogenic diet reduces body mass without compromising performance in powerlifting and Olympic weightlifting athletes. J Strength Cond Res 32(12): 3382-3391, 2018-Weight class athletes use weight-making strategies to compete in specific weight categories with an optimum power-to-weight ratio. There is evidence that low carbohydrate diets might offer specific advantages for weight reduction without the negative impact on strength and power previously hypothesized to accompany carbohydrate restriction. Therefore, the purpose of this study was to determine whether a low-carbohydrate ketogenic diet (LCKD) could be used as a weight reduction strategy for athletes competing in the weight class sports of powerlifting and Olympic weightlifting. Fourteen intermediate to elite competitive lifting athletes (age 34 ± 10.5, n = 5 female) consumed an ad libitum usual diet (UD) (>250 g daily intake of carbohydrates) and an ad libitum LCKD (≤50 g or ≤10% daily intake of carbohydrates) in random order, each for 3 months in a crossover design. Lifting performance, body composition, resting metabolic rate, blood glucose, and blood electrolytes were measured at baseline, 3 months, and 6 months. The LCKD phase resulted in significantly lower body mass (-3.26 kg, p = 0.038) and lean mass (-2.26 kg, p = 0.016) compared with the UD phase. Lean mass losses were not reflected in lifting performances that were not different between dietary phases. No other differences in primary or secondary outcome measures were found between dietary phases. Weight class athletes consuming an ad libitum LCKD decreased body mass and achieved lifting performances that were comparable with their UD. Coaches and athletes should consider using an LCKD to achieve targeted weight reduction goals for weight class sports.


Asunto(s)
Rendimiento Atlético , Dieta Baja en Carbohidratos , Dieta Cetogénica , Fenómenos Fisiológicos en la Nutrición Deportiva , Levantamiento de Peso , Adulto , Atletas , Metabolismo Basal , Glucemia/metabolismo , Composición Corporal , Estudios Cruzados , Ingestión de Energía , Ejercicio Físico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pérdida de Peso , Adulto Joven
11.
Transp Res Part A Policy Pract ; 118: 258-279, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30505075

RESUMEN

As standards for vehicle greenhouse gas emissions and fuel economy have become more stringent, concerns have arisen that the incorporation of fuel-saving technologies may entail tradeoffs with other vehicle attributes important to consumers such as acceleration performance. Assessing the effects of these tradeoffs on consumer welfare requires estimates of both the degree of the tradeoffs, and consumer willingness to pay (WTP) for the foregone benefits. This paper has two objectives. The first is to review recent literature that presents, or can be used to calculate, marginal WTP (MWTP) for vehicle attributes to describe the attributes that have been studied and the estimated MWTP values. We found 52 U.S.-focused papers with sufficient data to calculate WTP values for 142 different vehicle attributes, which we organized into 15 general groups of comfort, fuel availability, fuel costs, fuel type, incentives, model availability, non-fuel operating costs, performance, pollution, prestige, range, reliability, safety, size, and vehicle type. Measures of dispersion around central MWTP values typically show large variation in MWTP values for attributes. We explore factors that may contribute to this large variation via analysis of variance (ANOVA) and find that, although most have statistically significant effects, they account for only about one third of the observed variation. Case studies of papers that provide estimates from a variety of model formulations and estimation methods suggest that decisions made by researchers can strongly influence MWTP estimates. The paper's second objective is to seek consensus estimates for WTP for fuel cost reduction and increased acceleration performance. Meta-analysis of MWTP for reduced fuel cost indicates that estimates based on revealed vs. stated preference data differ, as do estimates from models that account for endogeneity and those that do not. We find greater consistency in estimates of MWTP for acceleration despite substantial uncertainty about the overall mean. We conclude with recommendations for improving the understanding of consumers' MWTP for vehicle attributes.

12.
Pediatr Exerc Sci ; 29(4): 456-464, 2017 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-28787264

RESUMEN

PURPOSE: To synthesize existing literatures on the impact of gymnastics participation on the skeletal health of young male gymnasts. METHODS: Following a systematic search, 12 studies were included in this review. Quality of included studies was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE modified) criteria. RESULTS: Assessment of skeletal health varied between and within imaging modality protocols. Gymnasts had higher total bone content, greater total and trabecular bone density, larger bone size, a thicker cortex, and higher estimates of bone strength than controls. Recreational studies reported no difference in height or weight between gymnasts and controls; however, elite gymnasts were shorter and lighter than nongymnasts. STROBE scores ranged from 65% to 95%. CONCLUSION: Gymnastics participation may be beneficial to the bone health of young males as gymnasts had higher bone density and bone mineral content, larger bones, and greater estimates of bone strength than controls.


Asunto(s)
Huesos/fisiología , Gimnasia , Antropometría , Atletas , Composición Corporal , Densidad Ósea , Humanos , Masculino
13.
J Strength Cond Res ; 31(5): 1443-1460, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27398915

RESUMEN

Higgins, TR, Greene, DA, Baker, MK. Effects of cold water immersion and contrast water therapy for recovery from team sport: a systematic review and meta-analysis. J Strength Cond Res 31(5): 1443-1460, 2017-To enhance recovery from sport, cold water immersion (CWI) and contrast water therapy (CWT) have become common practice within high level team sport. Initially, athletes relied solely on anecdotal support. As there has been an increase in the volume of research into recovery including a number of general reviews, an opportunity existed to narrow the focus specifically examining the use of hydrotherapy for recovery in team sport. A Boolean logic [AND] keyword search of databases was conducted: SPORTDiscus; AMED; CINAHL; MEDLINE. Data were extracted and the standardized mean differences were calculated with 95% confidence interval (CI). The analysis of pooled data was conducted using a random-effect model, with heterogeneity assessed using I. Twenty-three peer reviewed articles (n = 606) met the criteria. Meta-analyses results indicated CWI was beneficial for recovery at 24 hours (countermovement jump: p = 0.05, CI: -0.004 to 0.578; All-out sprint: p = 0.02, -0.056 to 0.801) following team sport. The CWI was beneficial for recovery at 72 hours (fatigue: p = 0.03, CI: 0.061-1.418) and CWT was beneficial for recovery at 48 hours (fatigue: p = 0.04, CI: 0.013-0.942) following team sport. The CWI was beneficial for neuromuscular recovery 24 hours following team sport, whereas CWT was not beneficial for recovery following team sport. In addition, when evaluating accumulated sprinting, CWI was not beneficial for recovery following team sports. In evaluating subjective measures, both CWI (72 hours) and CWT (24 hours) were beneficial for recovery of perceptions of fatigue, following team sport. However neither CWI nor CWT was beneficial for recovery, of perceptions of muscle soreness, following team sport.


Asunto(s)
Frío , Hidroterapia/métodos , Mialgia/terapia , Deportes/fisiología , Ejercicio Físico/fisiología , Fatiga/terapia , Humanos
14.
J Strength Cond Res ; 31(12): 3311-3318, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27379964

RESUMEN

Speranza, MJA, Gabbett, TJ, Greene, DA, Johnston, RD, and Sheppard, JM. Changes in rugby league tackling ability during a competitive season: the relationship with strength and power qualities. J Strength Cond Res 31(12): 3311-3318, 2017-This study examined the relationship between changes in tackling ability, and muscular strength and power during a semiprofessional rugby league competitive season. Twelve semiprofessional rugby league players (mean ± SD age, 23.3 ± 2.0 years) underwent tests of upper- and lower-body strength and power during the preseason period. Tackling ability was tested using video analysis of a standardized one-on-one tackling drill. Players repeated these tests after round 15 of a 25-match competitive season. Changes in 1 repetition maximum (1RM) squat (rs = 0.70; p < 0.02) and squat relative to body mass (rs = 0.73; p < 0.01) were significantly related to changes in tackling ability. Players with the greatest improvements in tackling ability (i.e., "responders") retained 1RM squat (effect size, ES = 0.85, p = 0.09) and squat relative to body mass (ES = 0.82, p = 0.15) to a greater extent than the "nonresponders." The results of this study suggest that players who retained lower-body strength were able to improve tackling ability during the competitive season, whereas reductions in lower-body strength were associated with decrements in tackling ability. This study highlights the importance of the development and maintenance of lower-body muscular strength for effective tackling performance throughout the rugby league season.


Asunto(s)
Rendimiento Atlético/fisiología , Fútbol Americano/fisiología , Fuerza Muscular/fisiología , Adulto , Humanos , Masculino , Adulto Joven
15.
Am J Occup Ther ; 71(2): 7102230010p1-7102230010p7, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28218590

RESUMEN

The purpose of this national survey was to explore perceptions of professional reward among occupational therapist (OT) and occupational therapy assistant (OTA) academic fieldwork coordinators (AFWCs). Agreement was found in ranking the value of six role factors: (1) fieldwork data management, (2) fieldwork site management, (3) fieldwork teaching and consultation, (4) departmental and institutional compliance, (5) scholarship and accreditation, and (6) laying groundwork for students in fieldwork. Both levels of AFWC indicated teaching and consultation had the highest value and data management the least. OT AFWCs placed significantly higher value on publishing articles and lower value on educating fieldwork educators about role delineation than OTA AFWCs. Five themes emerged regarding professional reward: (1) intrinsic reward, (2) collaboration, (3) development of the profession, (4) feeling appreciated, and (5) student success. AFWCs value activities involving personal interaction, promoting professional development, and facilitating student success. Results have implications for AFWC collaboration, workload distribution, and scholarship.


Asunto(s)
Actitud del Personal de Salud , Docentes , Terapeutas Ocupacionales , Terapia Ocupacional/educación , Recompensa , Acreditación , Conducta Cooperativa , Humanos , Estudiantes del Área de la Salud , Encuestas y Cuestionarios
16.
Ann Bot ; 117(7): 1163-73, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27107412

RESUMEN

BACKGROUND AND AIMS: Despite a longstanding interest in variation in tree species vulnerability to ice storm damage, quantitative analyses of the influence of crown structure on within-crown variation in ice accretion are rare. In particular, the effect of prior interception by higher branches on lower branch accumulation remains unstudied. The aim of this study was to test the hypothesis that intra-crown ice accretion can be predicted by a measure of the degree of sheltering by neighbouring branches. METHODS: Freezing rain was artificially applied to Acer platanoides L., and in situ branch-ice thickness was measured directly and from LiDAR point clouds. Two models of freezing rain interception were developed: 'IceCube', which uses point clouds to relate ice accretion to a voxel-based index (sheltering factor; SF) of the sheltering effect of branch elements above a measurement point; and 'IceTree', a simulation model for in silico evaluation of the interception pattern of freezing rain in virtual tree crowns. KEY RESULTS: Intra-crown radial ice accretion varied strongly, declining from the tips to the bases of branches and from the top to the base of the crown. SF for branches varied strongly within the crown, and differences among branches were consistent for a range of model parameters. Intra-crown variation in ice accretion on branches was related to SF (R(2) = 0·46), with in silico results from IceTree supporting empirical relationships from IceCube. CONCLUSIONS: Empirical results and simulations confirmed a key role for crown architecture in determining intra-crown patterns of ice accretion. As suspected, the concentration of freezing rain droplets is attenuated by passage through the upper crown, and thus higher branches accumulate more ice than lower branches. This is the first step in developing a model that can provide a quantitative basis for investigating intra-crown and inter-specific variation in freezing rain damage.


Asunto(s)
Acer/anatomía & histología , Hielo , Modelos Biológicos , Árboles/anatomía & histología , Acer/fisiología , Simulación por Computador , Congelación , Componentes Aéreos de las Plantas/anatomía & histología , Componentes Aéreos de las Plantas/fisiología , Quebec , Lluvia , Árboles/fisiología
17.
BMC Public Health ; 16(1): 873, 2016 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-27557641

RESUMEN

BACKGROUND: Despite the health benefits of regular physical activity, most children are insufficiently active. Schools are ideally placed to promote physical activity; however, many do not provide children with sufficient in-school activity or ensure they have the skills and motivation to be active beyond the school setting. The aim of this project is to modify, scale up and evaluate the effectiveness of an intervention previously shown to be efficacious in improving children's physical activity, fundamental movement skills and cardiorespiratory fitness. The 'Internet-based Professional Learning to help teachers support Activity in Youth' (iPLAY) study will focus largely on online delivery to enhance translational capacity. METHODS/DESIGN: The intervention will be implemented at school and teacher levels, and will include six components: (i) quality physical education and school sport, (ii) classroom movement breaks, (iii) physically active homework, (iv) active playgrounds, (v) community physical activity links and (vi) parent/caregiver engagement. Experienced physical education teachers will deliver professional learning workshops and follow-up, individualized mentoring to primary teachers (i.e., Kindergarten - Year 6). These activities will be supported by online learning and resources. Teachers will then deliver the iPLAY intervention components in their schools. We will evaluate iPLAY in two complementary studies in primary schools across New South Wales (NSW), Australia. A cluster randomized controlled trial (RCT), involving a representative sample of 20 schools within NSW (1:1 allocation at the school level to intervention and attention control conditions), will assess effectiveness and cost-effectiveness at 12 and 24 months. Students' cardiorespiratory fitness will be the primary outcome in this trial. Key secondary outcomes will include students' moderate-to-vigorous physical activity (via accelerometers), fundamental movement skill proficiency, enjoyment of physical education and sport, cognitive control, performance on standardized tests of numeracy and literacy, and cost-effectiveness. A scale-up implementation study guided by the RE-AIM framework will evaluate the reach, effectiveness, adoption, implementation, and maintenance of the intervention when delivered in 160 primary schools in urban and regional areas of NSW. DISCUSSION: This project will provide the evidence and a framework for government to guide physical activity promotion throughout NSW primary schools and a potential model for adoption in other states and countries. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Registry ( ACTRN12616000731493 ). Date of registration: June 3, 2016.


Asunto(s)
Ejercicio Físico , Capacitación en Servicio , Educación y Entrenamiento Físico , Aptitud Física , Servicios de Salud Escolar , Maestros , Instituciones Académicas , Adolescente , Enfermedades Cardiovasculares/prevención & control , Niño , Análisis Costo-Beneficio , Femenino , Promoción de la Salud , Humanos , Internet , Aprendizaje , Motivación , Nueva Gales del Sur , Padres , Evaluación de Programas y Proyectos de Salud , Desempeño Psicomotor , Proyectos de Investigación , Deportes
18.
J Strength Cond Res ; 30(2): 360-7, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26200191

RESUMEN

This study investigated the relationship between GPS variables measured in training and gameplay and injury occurrences in professional soccer. Nineteen professional soccer players competing in the Australian Hyundai A-League were monitored for 1 entire season using 5 Hz Global Positioning System (GPS) units (SPI-Pro GPSports) in training sessions and preseason games. The measurements obtained were total distance, high-intensity running distance, very-high-intensity running distance, new body load, and meters per minute. Noncontact soft tissue injuries were documented throughout the season. Players' seasons were averaged over 1- and 4-week blocks according to when injuries occurred. These blocks were compared with each other and with players' seasonal averages. Players performed significantly higher meters per minute in the weeks preceding an injury compared with their seasonal averages (+9.6 and +7.4% for 1- and 4-week blocks, respectively) (p < 0.01), indicating an increase in training and gameplay intensity leading up to injuries. Furthermore, injury blocks showed significantly lower average new body load compared with seasonal averages (-15.4 and -9.0% for 1- and 4-week blocks, respectively) (p < 0.01 and p = 0.01). Periods of relative underpreparedness could potentially leave players unable to cope with intense bouts of high-intensity efforts during competitive matches. Although limited by Fédération Internationale de Football Association regulations, the results of this study isolated 2 variables predicting soft tissue injuries for coaches and sports scientists to consider when planning and monitoring training.


Asunto(s)
Traumatismos en Atletas/prevención & control , Sistemas de Información Geográfica , Fútbol/lesiones , Adulto , Humanos , Masculino , Esfuerzo Físico/fisiología , Traumatismos de los Tejidos Blandos/etiología , Traumatismos de los Tejidos Blandos/prevención & control
19.
J Strength Cond Res ; 30(10): 2845-56, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26849783

RESUMEN

Millett, EL, Moresi, MP, Watsford, ML, Taylor, PG, and Greene, DA. Lower body stiffness modulation strategies in well trained female athletes. J Strength Cond Res 30(10): 2845-2856, 2016-Lower extremity stiffness quantifies the relationship between the amount of leg compression and the external load to which the limb are subjected. This study aimed to assess differences in leg and joint stiffness and the subsequent kinematic and kinetic control mechanisms between athletes from various training backgrounds. Forty-seven female participants (20 nationally identified netballers, 13 high level endurance athletes and 14 age and gender matched controls) completed a maximal unilateral countermovement jump, drop jump and horizontal jump to assess stiffness. Leg stiffness, joint stiffness and associated mechanical parameters were assessed with a 10 camera motion analysis system and force plate. No significant differences were evident for leg stiffness measures between athletic groups for any of the tasks (p = 0.321-0.849). However, differences in joint stiffness and its contribution to leg stiffness, jump performance outcome measures and stiffness control mechanisms were evident between all groups. Practitioners should consider the appropriateness of the task utilised in leg stiffness screening. Inclusion of mechanistic and/or more sports specific tasks may be more appropriate for athletic groups.


Asunto(s)
Rendimiento Atlético/fisiología , Ejercicio Físico/fisiología , Extremidad Inferior/fisiología , Músculo Esquelético/fisiología , Adolescente , Adulto , Fenómenos Biomecánicos , Estudios Transversales , Femenino , Humanos , Tamizaje Masivo/métodos , Deportes , Adulto Joven
20.
Occup Ther Health Care ; 30(4): 388-401, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27689863

RESUMEN

The Canadian Occupational Performance Measure (COPM) has been used to assess the effectiveness of assistive technology (AT). We explored whether a modified COPM was sensitive to change in perceived performance and satisfaction, and whether frequency of AT use resulted in greater change in the domains measured (reading, writing, note-taking, test-taking, and study skills). Significant interactions were found between time and use frequency with greater change in perceived performance in the daily-use group in several domains. In addition, the intra-class correlation showed moderate to strong equivalent forms reliability between two assessment formats. Based on these preliminary results, the ATRC-mCOPM was found to be a sensitive measure of perceived performance and satisfaction utilizing AT services in a postsecondary education setting.


Asunto(s)
Actividades Cotidianas , Terapia Ocupacional , Dispositivos de Autoayuda , Canadá , Humanos , Reproducibilidad de los Resultados
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