Mediterranean pine forest decline: A matter of root-associated microbiota and climate change.

Forest ecosystems worldwide currently face worrying episodes of forest decline, which have boosted weakening and mortality of the trees. In the Mediterranean region, especially in the southeast Iberian Peninsula, Pinus sylvestris forests are severely affected by this phenomenon, and it has been commonly attributed to drought events. Remarkably, the role of root microbiota on pine decline has been overlooked and remains unclear. We therefore used metabarcoding to identify the belowground microbial communities of decline-affected and unaffected pine trees. Taxonomic composition of bacterial and fungal rhizosphere communities, and fungal populations dwelling in root endosphere showed different profiles depending on the health status of the trees. The root endosphere of asymptomatic trees was as strongly dominated by 'Candidatus Phytoplasma pini' as the root of decline-affected pines, accounting for >99 % of the total bacterial sequences in some samples. Notwithstanding, the titer of this phytopathogen was four-fold higher in symptomatic trees than in symptomless ones. Furthermore, the microbiota inhabiting the root endosphere of decline-affected trees assembled into a less complex and more modularized network. Thus, the observed changes in the microbial communities could be a cause or a consequence of forest decline phenomenon. Moreover, 'Ca. Phytoplasma pini' is positively correlated to Pinus sylvestris decline events, either as the primary cause of pine decline or as an opportunistic pathogen exacerbating the process once the tree has been weaken by other factors.

Effects of hour of training and exercise intensity on nocturnal autonomic modulation and sleep quality of amateur ultra-endurance runners.

Sleeping problems can affect physiological adaptations and the recovery process. The aim of this study was to analyse the effect of the intensity and the hour of the training session on sleep quality and cardiac autonomic activity in amateur ultra-endurance athletes. We used a comparative, randomized crossover design to test the effect of moderate (M) or vigorous (V) intensity and morning (m) or evening (e) training journey, separated by 72 h of recovery, on actigraphic and subjective sleep quality and nocturnal cardiac autonomic activity in fourteen ultra-endurance male runners. No significant differences among training sessions were found in nocturnal heart rate variability or in subjective sleep quality, but participants experienced significantly higher calm sleep after Mm than Me (p = 0.028; ES = 0.7) and more refreshed after awakening when they performed a Me than Vm (p = 0.04; ES = 0.6). Higher sleep efficiency was found when the training is performed in the morning compared to the evening sessions in both intensities, and it was also observed in Me vs Ve (p = 0.012; ES = 0.8). Significantly lower numbers of awakenings were observed when the training was performed in the morning, and actual sleep time was significantly lower when participants performed a vigorous training session compared to a moderate one (Vm vs Mm: p = 0.035; ES = 0.6; Ve vs Mm: p = 0.036; ES = 0.6). Moderate exercise performed in the morning had a higher sleep efficiency compared to other types of training and intensity training is more important than the time of the day of training on sleep quality.

The weight of the past: land-use legacies and recolonization of pine plantations by oak trees.

Most of the world's plantations were established on previously disturbed sites with an intensive land-use history. Our general hypothesis was that native forest regeneration within forest plantations depends largely on in situ biological legacies as a source of propagules. To test this hypothesis, we analyzed native oak regeneration in 168 pine plantation plots in southern Spain in relation to land use in 1956, oak patch proximity, and pine tree density. Historical land-use patterns were determined from aerial photography from 1956, and these were compared with inventory data from 2004-2005 and additional orthophoto images. Our results indicate that oak forest regeneration in pine plantations depends largely on land-use legacies, although nearby, well-conserved areas can provide propagules for colonization from outside the plantation, and pine tree density also affected oak recruit density. More intense land uses in the past meant fewer biological legacies and, therefore, lower likelihood of regenerating native forest. That is, oak recruit density was lower when land use in 1956 was croplands (0.004 +/- 0.002 recruits/m2 [mean +/- SE]) or pasture (0.081 +/- 0.054 recruits/m2) instead of shrubland (0.098 +/- 0.031 recruits/m2) or oak formations (0.314 +/- 0.080 recruits/m2). Our study shows that land use in the past was more important than propagule source distance or pine tree density in explaining levels of native forest regeneration in plantations. Thus, strategies for restoring native oak forests in pine plantations may benefit from considering land-use legacies as well as distance to propagule sources and pine density.

Effects of high-resistance circuit training in an elderly population.

The aim of this study was to determine the efficacy of a program of high-resistance circuit (HRC) training, and to compare the effects of HRC to traditional heavy strength (TS) training on strength, muscle size, body composition and measures of cardiovascular fitness in a healthy elderly population. Thirty-seven healthy men and women (61.6±5.3years) were randomly assigned to HRC (n=16), TS (n=14), or a control group (CG, n=7). Training consisted of weight lifting twice a week for 12weeks. Before and after the training, isokinetic peak torque in the upper and lower body, and body composition (dual X-ray absorptiometry) were determined. In addition, cardiovascular parameters were evaluated during an incremental treadmill test. Both HRC and TS groups showed significant increases in isokinetic strength (p<0.001), and the increase was significantly greater in the experimental groups than in CG (p<0.03). There were significant increases in lean mass (HRC, p<0.001; TS, p=0.025) and bone mineral density (HRC, p=0.025; TS, p=0.018) in the experimental groups. Only HRC showed a significant decrease in fat mass (p=0.011); this decrease was significantly greater in HRC than in CG (p=0.039). There were significant improvements in walking economy in the HRC group (p<0.049), although there were no statistical differences between groups. There were no changes in any variables in CG. Hence, HRC training was as effective as TS for improving isokinetic strength, bone mineral density and lean mass. Only HRC training elicited adaptations in the cardiovascular system and a decrease in fat mass.

Estudio comparativo postesfuerzo de lactacidemia, PH y electrolitos según el lugar de muestreo / Comparative study I postexercise lactacidemia, PH and electrolytes depending of the site of sampling

Existen múltiples estudios en los que se demuestra la existencia de cifras de lactacidemia distintas dependiendo del componente sanguíneo analizado (sangre completa o plasma), del vaso sanguíneo utilizado para realizar la extracción (arteria, capilar o vena), del lugar de toma de la muestra (miembro ejercitado en reposo), del tiempo que transcurre hasta el análisis de la muestra, de la metodología empleada para la extracción y del analizador utilizado. Dada la importancia del lactato como parámetro biológico clave implicado en los mecanismos de la fatiga muscular, así como en la determinación de las zonas de transición metabólica aeróbica-anaeróbica durante la actividad física y la trascendencia de éstas en la programación del entrenamiento, nos parece necesario investigar la posible influencia de los distintos factores mencionados sobre los valores de lactacidemia. El mayor conocimiento de todas estas variables aportará nuevos datos para mejorar la metodología en lo referente, entre otros aspectos, al lugar óptimo de extracción, la técnica utilizada y el análisis de las muestras sanguíneas, lo que nos permitirá obtener conclusiones fisiológicas más fiables. En nuestro estudio hemos apreciado diferencias significativas entre los valores de lactato aportados por las micromuestras sanguíneas de oreja y pulpejo del dedo y los procedentes del sudor, siendo estos últimos mucho mayores; no resultando significativas, por el contrario, las observadas entre las micromuestras del dedo y la oreja. También nos parece interesante estudiar otros parámetros en estas muestras biológicas y observar sus posibles relaciones. Concretamente, pretendemos analizar la relación que algunos autores han observado entre las cifras de lactato, los gases sanguíneos y algunos iones implicados en el anión gap1-3. En este sentido, la variable Presión Parcial de Oxígeno (PpO2) parece tener una escasa influencia en las cifras de lactato obtenidas delas micromuestras del dedo y oreja, y tampoco se ha observado una buena correlación lineal entre las lactacidemias sudor de doy sudor-oreja. En cuanto a los electrolitos, hemos obtenido diferencias significativas en cuanto al sodio, calcio, cloruro y bicarbonato, siendo en todos ellos mayores las cifras halladas en la muestra del dedo (AU)

There exist multiple studies in which is demonstrated the existence of different numbers of lactacidemia depending of the blood component analyzed (complete blood or plasma), of the blood glass used to realize the extraction (artery, capillary or vein), of the place of capture of the sample (exercised member or in rest), of the time that passes up to the analysis of the sample, of the methodology used for the extraction and of the used analyzer. Given the importance of the lactate as biological key parameter involved in the mechanisms of the muscular fatigue, as well as in the determination of the zones of metabolic transition aerobic-anaerobic during the physical activity and the trascendency of these in the programming of the training, us seems to be necessary to investigate the possible influence of the different factors mentioned on the values of lactacidemia. The greater knowledge of all these variables will contribute new information to improve the methodology in the relating thing, among other aspects, to the ideal place of extraction, the used technology and the analysis of the blood samples, which will allow us to extract trust worthier physiological conclusions. In our study we have estimated significant differences between the values of lactate contributed by the fingertip and ear lobe blood microsamples and the proceeding ones from the sweat, being very much bigger the above mentioned; not being significant, on the contrary, the observed ones between the micro samples of the finger and the ear. Also it seems us interesting to analyze other parameters in these biologycal samples and to study its possible relations Concretely, we try to analyze the relationship that some authors have observed between the numbers of lactate, blood gases and some ions implied in the an ión gap1-3. In these sense, the parameter Partial Pressure of Oxygen (PpO2) seems to have a scanty influence in the numbers of lactate obtained of the finger and ear, and a good linear correlation has not been observed between the lactacidemias sweat-finger and sweat-ear either. As for the electrolytes, we have obtained significant differences as for the sodium, calcium, chloride, and bicarbonate, being higher in all of them the numbers found in the sample of the finger (AU)

Factores que influyen sobre el vaciado gástrico de bebidas deportivas durante el ejercicio / Factors affectin gastric emptying of sport beverage during exercise

Los factores que contribuyen más decisivamente a la fatiga durante el ejercicio físico son el agotamiento de carbohidratos (CHO) y la deshidratación. El proceso final de rehidratación depende tanto del ritmo al cual la bebida abandona el estómago (vaciado gástrico) como de la absorción intestinal; también es conocido que la ingesta de una bebida de reposición adecuada durante el mismo retrasa la fatiga y mejora el rendimiento deportivo. Entre los múltiples factores que influyen en el vaciado gástrico encontramos características propias de la bebida ingerida (volumen, frecuencia de ingesta, densidad energética, osmolalidad, temperatura y pH de la solución), variables dependientes del ejercicio (intensidad y tipo de ejercicio), y otros factores (nivel de hidratación, estrés, cafeína, ritmo circadiano, condiciones ambientales, sexo femenino y fase del ciclo menstrual). Actualmente todos los estudios revisados defienden que las variables más determinantes del ritmo de vaciado gástrico son el volumen de bebida ingerido y la densidad energética de la misma. Existen grandes variaciones individuales en el ritmo de vaciado gástrico y en la tolerancia a la ingesta de importantes volúmenes de bebida, pero se recomienda ingerir bebidas de reposición adecuadas a la práctica deportiva antes, durante y/o después de las sesiones de entrenamiento o el ejercicio, pudiendo así mejorar la tolerancia

Carbohydrate deplection and dehydration are the most important factors affecting gastric emptying. The last process of rehydration depend as soon as gastric emptying rate as intestinal absorption; it is known that an adecuate sport beverage ingestion during exercise delay the onset of fatigue and improve performance. Between many factors affecting gastric emptying are characteristics of a sport drink (volume, frecuency ingestion, caloric content, osmolality, temperature and pH), factors depending of exercise (intensity and type), and others factors (hydration level, stress, caffeine, circadian rhythm, environment conditions, female and menstrual cycle). Actually, all literature revised state the more important factors affecting gastric emptying are the volume and the caloric content of ingested sport beverage. There is large individual variation in gastric emptying rate and tolerance to larger volumes. Training to drink an adecuate sport beverage before, during and/or after training sessions or exercise is recommended and could improve enhance tolerance