Transpiration of montane <I>Pinus sylvestris</I> L. and <I>Quercus pubescens</I> Willd. forest stands measured with sap flow sensors in NE Spain

International audienceStand transpiration was measured during the 2003 and 2004 growing seasons using heat dissipation sap flow sensors in a Scots pine (Pinus sylvestris L.) and a pubescent oak (Quercus pubescens Willd.) forest located in a montane area of the Eastern Pyrenees (NE Spain). The first aim of the study was to assess the differences in quantitative estimates of transpiration (Ec) and the response to evaporative demand of the two stands. Over the studied period of 2003, characterised by a severe drought episode during the summer, the oak stand Ec was only 110mm compared to the 239 mm transpired by the Scots pine stand, although the ratio of transpiration to reference evapotranspiration (Ec/ET0) in the oak stand compares well with the expected values predicted for low leaf area index (LAI) oak forests in southern Europe. Scots pine showed a strong reduction in Ec/ET0 as the drought developed, whereas pubescent oak was less affected by soil moisture deficits in the upper soil. As a second objective, and given the contrasting meteorological conditions between 2003 and 2004 summer periods, the interanual variability of transpiration was studied in the Scots pine plot. Rainfall during the summer months (June-September) in 2003 was almost 40% less than in the same interval in 2004. Accordingly, transpiration was also reduced about 25% in 2003. Finally, Scots pine data from 2003 and 2004 was used to calibrate a simple transpiration model using ET0 and soil moisture deficit (SMD) as input variables, and implicitly including stomatal responses to high vapour pressure deficits (D?) and soil water status

Transpiration of montane Pinus sylvestris L. and Quercus pubescens Willd. forest stands measured with sap flow sensors in NE Spain

Stand transpiration was measured during the 2003 and 2004 growing seasons using heat dissipation sap flow sensors in a Scots pine (Pinus sylvestris L.) and a pubescent oak (Quercus pubescens Willd.) forests located in a montane area of the Eastern Pyrenees (NE Spain). The first aim of the study was to assess the differences in quantitative estimates of transpiration (Ec) and the response to evaporative demand of the two stands. Over the studied period of 2003, characterised by a severe drought episode during the summer, the oak stand E2 was only 110 turn compared to the 239 mm transpired by the Scots pine stand, although the ratio of transpiration to reference evapotranspiration (Ec/ET0) in the oak stand compares well with the expected values predicted for low leaf area index (LAI) oak forests in southern Europe. Scots pine showed a strong reduction in Ec/ET0) as the drought developed, whereas pubescent oak was less affected by soil moisture deficits in the upper soil. As a second objective, and given the contrasting meteorological conditions between 2003 and 2004 summer periods, the interannual variability of transpiration was studied in the Scots pine plot. Rainfall during the summer months (June-September) in 2003 was almost 40% less than in the same interval in 2004. Accordingly, transpiration was also reduced about 25% in 2003. Finally, Scots pine data from 2003 and 2004 was used to calibrate a simple transpiration model using ET0 and soil moisture deficit (SMD) as input variables, and implicitly including stomatal responses to high vapour pressure deficits (Dd) and soil water status. © 2005 Author(s). This work is licensed under a Creative Commons License.This research was supported by the projects PROHISEM (REN2001-2268-C02-01/HID), PIRIHEROS (REN2003-08768/HID) and CANOA (CGL2004-04919-C02- 01), funded by the Spanish Ministerio de Ciencia y Tecnología (MCYT)/Ministerio de Educación y Ciencia (MEC). The Vallcebre research area also operates with support from the RESEL network through an agreement between the CSIC and DGCONA.Peer Reviewe

Online Resources Platform for Mathematics Education

The aim of this project was to develop and explore the use of a Sharable Content Object Reference Model (SCORM) integrating a web-based platform for the study of mathematics as part of an active learning environment. The platform was designed to provide active support to engineering students especially those in their first year of study. Early use of the platform can identify possible areas of weakness and provide the self-learning environment required for students to become more proficient in areas where they are lacking key skills or are finding the concepts difficult to understand. The platform consists of a set of tests and applications for the study of engineering mathematics. The tests can adapt and change depending on the answers provided by the student, including video feedback for incorrect answers before the student progresses to the next question. Based on the idea that teaching a concept is the best way to learn that concept, the students become actively involved in the platform as they create the videos that provide feedback to the other users of the platform. This active learning, constructivist approach provides an environment of achievement and ownership that allows students of all levels to enjoy the learning experience

Standardized experimental estimation of the maximum unnoticeable environmental displacement during eye blinks for redirect walking in virtual reality

Redirect walking is a technique that aims to manipulate the walking trajectories in immersive virtual reality settings by inducing unnoticeable displacements of the virtual environment. Taking into advantage the change blindness phenomenon, visual occlusion during eye blinks has been recently proposed to perform those displacements. This study determined the maximum unnoticeable displacement that can be performed in practical scenario, which proved to be near 0.8° of occlusion and disocclusion in both horizontal and vertical axes

Epifisiolisis obstétrica de la extremidad proximal de la tibia: a propósito de un caso

Presentamos un caso de Epifisiolisis Obstétrica de la extremidad superior de la tibia tipo I de Salter y Harris. El diagnóstico es difícil y muchas vece s tardío por ser una lesión obstétrica rara y ser casi ausentes los signos radiológicos en los primeros días. El mecanismo parece estar relacionado a la posición fetal intraútero y manipulación de los miembros durante el parto. Aunque son frecuentes las ligeras deformidade s como secuela, no provocan transtornos funcionale s y mejoran notablement e con el crecimiento.We repor t a cas e of Obstetri c Epiphysiolysis of th e Proxima l Tibi a Epiphysis. The diagnosis is difficult and usually delayed becaus e it is a rare obstetric injury and the radiological signs are scanty. The traumatic mechanism involved appears to be related to a certain "in utero" position and the manipulation of the legs during delivery. Although slight deformations are frecuent, thes e do not induc e functional consequence s and improve by its self with growth

Spatial variability in the soil water content of a Mediterranean agroforestry system with high soil heterogeneity

Variability of soil water content is known to increase with the size of spatial domain in which measurements are taken. At field scale, heterogeneity in soil, vegetation, topography, water input volume and management affects, among other factors, hydrologic plot behaviour under different mean soil water contents. The present work studies how the spatial variability of soil water content (SWC) is affected by soil type (texture, percentage of stones and the combination of them) in a timber-orientated plantation of cherry tree (Prunus avium) under Mediterranean climatic conditions. The experimental design is a randomized block one with 3 blocks * 4 treatments, based on two factors: irrigation (6 plots irrigated versus 6 plots not irrigated) and soil management (6 plots tillaged versus 6 plots not tillaged). SWC is continuously measured at 25, 50 and 100 cm depth with FDR sensors, located at two positions in each treatment: under tree influence and 2.5 m apart. This study presents the results of the monitoring during 2012 of the 24 sensors located at the 25 cm depth. In each of the measurement point, texture and percentage of stones were measured. Sandy-loam, sandy-clay-loam and loam textures were found together with a percentage of stones ranging from 20 to 70 %. The results indicated that the relationship between the daily mean SWC and its standard deviation, a common procedure used to study spatial variability, changed with texture, percentage of stones and the estimation of field capacity from the combination of both. Temporal stability analysis of SWC showed a clear pattern related to field capacity, with the measurement points of the sandy-loam texture and the high percentage of stones showing the maximun negative diference with the global mean. The high range in the mean relative difference observed ( 75 %), could indicate that the studied plot may be considered as a good field-laboratory to extrapolate results at higher spatial scales. Furthermore, the pattern in the temporal stability of tree growth was clearly related to that one in SWC. Nevertheless, the treatments that represent the mean conditions in growth were not exactly the same than those in SWC, which could be attributable to other characteristics than soil

Cerclajes y enclavado intramedular en fracturas subtrocantéreas: ¿vascularización femoral o reducción anatómica?

Nuestro objetivo es valorar el beneficio y los resultados clínico-radiológicos del uso de los cerclajes y el enclavado intramedular en las fracturas subtrocantéreas tipo IIIA de Seinsheimer y compararlo con un grupo control. Se utilizaron dos grupos de 19 pacientes (grupo con cerclaje y grupo sin cerclaje) y se obtuvieron los siguientes resultados; tasas de reducción anatómica 89.5% y 84.2%; tasas de consolidación 100% y 94,7%; tiempo medio de consolidación 20 y 23.9 semanas. Los resultados utilizando la escala de Harris fueron de 62,7 y 68,3; y una tasa de complicaciones del 5.2% y del 21%. Estos resultados sugieren que el uso de cerclajes en las fracturas subtrocantéreas, no influencia de forma negativa nuestra tasa de consolidación, infección o complicaciones; sin embargo promovemos el uso de cerclajes después de intentar la reducción de manera cerrada, y siempre con un buen manejo de partes blandas.Our goal is to assess the benefit and the clinical and radiological outcomes of using cerclage and intramedullary nail in subtrochanteric fractures type IIIA of Seinsheimer and comparing with a control group. Two groups of 19 patients (cerclage group and non-cerclage group) were used and the following results were obtained; anatomic reduction rates 89.5% and 84.2; consolidation rates 100% and 94.7%; mean healing time 20 and 23.9 weeks. Our mean Harris Hip Score were 62.7 and 68.3; and a complication rate of 5.2% and 21%. The results suggest that the use of cerclage in subtrochanteric fractures does not negatively influence in the rate of consolidation, infection or complications as opposed to a subotpimal reduction. Nevertheless we emphasize open reduction and cerclage wiring after the attempt of closed reduction, and always taking care of soft tissues