Role of leaf hydraulic conductance in the regulation of stomatal conductance in almond and olive in response to water stress

11 páginas..-- 5 figuras.-- 1 tablas.-- 55 referencias.-- We thank A. Montero for field work assistance, J. Perez Hormaeche for helping us with the VD images analysis and T. Brodribb and J.M. Torres-Ruiz for discussion.The decrease of stomatal conductance (gs) is one of the prime responses to water shortage and the main determinant of yield limitation in fruit trees. Understanding the mechanisms related to stomatal closure in response to imposed water stress is crucial for correct irrigation management. The loss of leaf hydraulic functioning is considered as one of the major factors triggering stomatal closure. Thus, we conducted an experiment to quantify the dehydration response of leaf hydraulic conductance (Kleaf) and its impact on gs in two Mediterranean fruit tree species, one deciduous (almond) and one evergreen (olive). Our hypothesis was that a higher Kleaf would be associated with a higher gs and that the reduction in Kleaf would predict the reduction in gs in both species. We measured Kleaf in olive and almond during a cycle of irrigation withholding. We also compared the results of two methods to measure Kleaf: dynamic rehydration kinetics and evaporative flux methods. In addition, determined gs, leaf water potential (Ψleaf), vein density, photosynthetic capacity and turgor loss point. Results showed that gs was higher in almond than in olive and so was Kleaf (Kmax = 4.70 and 3.42 mmol s-1 MPa-1 m-2, in almond and olive, respectively) for Ψleaf > -1.2 MPa. At greater water stress levels than -1.2 MPa, however, Kleaf decreased exponentially, being similar for both species, while gs was still higher in almond than in olive. We conclude that although the Kleaf decrease with increasing water stress does not drive unequivocally the gs response to water stress, Kleaf is the variable most strongly related to the gs response to water stress, especially in olive. Other variables such as the increase in abscisic acid (ABA) may be playing an important role in gs regulation, although in our study the gs-ABA relationship did not show a clear pattern..This work was funded by the Spanish Ministry of Science and Innovation (research project AGL2009-11310/AGR). V.H.-S. benefited from a Juan de la Cierva research fellowship from the Spanish Ministry of Science and Innovation and C.M.R.-D. benefited from a FPDI research fellowship from the Junta de Andalucí

Scaling Relations and Exponents in the Growth of Rough Interfaces Through Random Media

The growth of a rough interface through a random media is modelled by a continuous stochastic equation with a quenched noise. By use of the Novikov theorem we can transform the dependence of the noise on the interface height into an effective temporal correlation for different regimes of the evolution of the interface. The exponents characterizing the roughness of the interface can thus be computed by simple scaling arguments showing a good agreement with recent experiments and numerical simulations.Comment: 4 pages, RevTex, twocolumns, two figures (upon request). To appear in Europhysics Letter

Tratamiento del choque femoroacetabular mediante miniabordaje anterior. Resultados a corto plazo

El tratamiento quirúrgico del choque femoroacetabular (CFA) es un práctica clínica cada vez más frecuente en nuestra especialidad. Objetivo. Analizar los resultados clínicos y radiológicos de una primera serie de pacientes diagnosticados de CFA intervenidos mediante miniabordaje anterior. Material y métodos. Estudio prospectivo de 30 pacientes con una edad media de 36,2 años y un seguimiento mínimo de 12 meses. La valoración clínica se ha realizado mediante las escalas SF-36, WOMAC y NAHS. Evaluamos la corrección radiológica de la deformidad y la progresión o no del grado de coxartrosis. Resultados. Se obtuvo una corrección adecuada de la deformidad en el 93% de los casos, 27 de los 30 pacientes presentaron una mejoría clínica significativa en los test realizados. La complicación más frecuente fue la meralgia parestésica del femorocutáneo (5 casos), 1 paciente precisó de sustitución protésica por evolución del grado de coxartrosis. Conclusiones. El tratamiento del CFA mediante mini abordaje anterior es un procedimiento seguro y reproducible. Permite la corrección de las anormalidades anatómicas y la obtención de resultados clínicos satisfactorios en una cohorte de pacientes jóvenes.Surgical treatment of femoroacetabular impingement (FAI) is an increasingly common clinical practice in our speciality. Aim. To analyze the clinical and radiological results of a first series of patients diagnosed with a FAI treated with anterior mini-open approach. Material and methods. Prospective study of 30 patients with a mean age of 36.2 years with a minimum follow-up of 12 months was made. Clinical assessment was performed using the SF-36, WOMAC and NAHS scales. We evaluate the correction of the radiologic deformity and progression of the osteoarthritis grade. Results. An adequate correction of the deformity in 93% of cases was obtained, 27 of the 30 patients showed significant clinical improvement in all tests performed. The most common complication was meralgia paresthesia of the femoro-cutaneous nerve (5 cases), 1 patient required prosthetic replacement for progression of the osteoarthritis grade. Conclusions. FAI treatment by mini-open approach is a safe and reproducible procedure. This technique allows correction of anatomical abnormalities and obtains satisfactory clinical outcomes in a cohort of young patients

Prótesis de pirocarbono en fracturas complejas de cabeza de radio.

Presentamos los resultados de un estudio observacional retrospectivo sobre 23 casos de fracturas complejas de cabeza de radio tratadas mediante la implantación de una prótesis cabeza radio de pircocarbono (Mo - Pyc). La distribución por sexos fue 10 hombres y 13 mujeres, y la edad media de 54 años. El seguimiento medio fue de 70 meses (48-93 meses). La principal causa fue una fractura de cabeza de radio no reconstruible con inestabilidad asociada de codo. La evaluación clínica se realizó con la Mayo Elbow Performance Score (MEPS). Radiográficamen - te se valoró la congruencia articular, el tamaño de la prótesis, la radiolucencia periprotésica, la osificación heterotópica y la osteoartritis. Al final del seguimiento la media de la escale MEPS fue 82/100, con 84 % resultados de excelentes y buenos. La flexión media fue de 130º, extensión -30º, pronación 76º y supinación 77º. La estabilidad del codo fue buena en todos los casos y no observamos migración proximal del radio. Observamos radiolucencia alrededor del vástago en 5 pacientes, pero sin aparente repercusión clínica. Las complicaciones fueron una paresia del nervio interóseo posterior con recuperación funcional al cabo de 11 semanas, 2 pacientes presentaron "overstuffing" con subluxación posterior asociada que necesitó realizar exéresis de la cabeza y una osificación heterotópica con repercu - sión sobre el balance articular que necesitó 2 cirugías, todos ellos con resultados clínicos aceptables. Los resultados son alentadores.The authors present the results of a retrospective observational study of 23 cases of a complex radial head fractures treated by pyrocarbon radial head prosthesis (MoPyc). This modular radial head prosthesis is compo - sed of a cementless titanium stem and a 15º angulated neck. The gender distribution was 10 men and 13 women, ave - rage age 54 years. The mean follow-up was 70 months (48-93 months). The main etiology was a radial head fracture with elbow instability. Clinical evaluation was performed using the Mayo Elbow Performance Score (MEPS). Was assessed radiographically joint congruity, the size of the prosthesis, periprosthetic radiolucency, heterotopic ossifica - tion and osteoarthritis. At follow-up, the MEPS average was 82/100, with 84% of good and excellent results. Elbow flexion averaged 130º, extension -30º, pronation 76º and supination 77º. Elbow stability was good in all the cases, and no proximal migration of the radius occurred. Asymptomatic bone lucencies were found in five cases around the stem. Complications included paresis of the posterior interosseous nerve with functional recovery after 11 weeks, 2 patients had "overstuffing" associated with posterior subluxation and they need to perform excision of the head and one heterotopic ossification with articular impact on balance that needs two surgeries, all of them with acceptable clinical results. The preliminary results are encouragin

Linking changes in radial profiles of sap flux density with the response of water vapour exchange to water deficit

8 páginas, 5 figuras, 1 tabla, 19 referencias.-- IX International Workshop on Sap Flow, celebrado del 4-7 de junio 2013, en Gante, Bélgica.Knowledge of temporal variations in radial profiles of sap flux density (Js) and its relation to canopy water vapour exchange would help to improve our understanding of plant water relations. In this study we aimed to test if there is a consistent radial profile of Js in olive trees under optimal soil water availability and severe water stress conditions. Furthermore, if the radial profile of Js is not consistent through time we aimed to assess whether this radial variability can be explained through differential water exchange response to evaporative demand (D) of sun-exposed, new foliage and shade, old foliage. We measured sap flux density in the trunk of 6-year-old olive trees under two different irrigation treatments: a full irrigation treatment and a treatment replacing 30% of the of irrigation needs. We related the hourly radial profiles characterized with the Beta probability distribution function with independent water vapour exchange measurements at different exposures in the tree canopy (sun-exposed, young foliage and shade, old foliage). Results showed that under well irrigated conditions the shape of the radial profile of Js hardly varied, but under water deficit situations most of the sap appears to be conducted deeper into the sapwood and Js is also more variable throughout the sapwood. Accordingly, results demonstrated that in shade, old foliage water vapour exchange varied less than in sun-exposed new foliage. As a result, in days under severe water deficit, the contribution of shade old foliage to the whole tree transpiration was greater. Radial profile changes and canopy measurements were found to respond in a similar way to D. During conditions of low D and soil water deficit it was observed a greater contribution of the inner xylem to total stem flow and shade, old leaves to canopy gas exchange.Peer reviewe

Thermoregulatory and Feeding Behavior under Different Management and Heat Stress Conditions in Heifer Water Buffalo (Bubalus bubalis) in the Tropics

In the wake of climate change and global warming, the production systems of water buffaloes (Bubalus bubalis) are receiving increasing attention in the tropics, where the silvopastoral systems can improve animal welfare and production conditions. The objective of this study was to characterize the behavior of heifer buffaloes in a silvopastoral system (SPS) with Leucaena leucocephala (600 trees/ha) and in a conventional system (CVS), under intense heat stress and moderate heat stress in Cuba. We observed nine animals, with an average weight of 167.9 kg at the beginning of the study, during the daylight period, from 6:00 to 18:00 h, at 10 min intervals, for 12 days. Activities recorded were grazing, ingestion of tree leaves, rumination, water intake, walking, lying, standing, sheltering in the shade of trees, and wallowing. Sheltering in the shade of trees and wallowing were collectively considered as thermoregulatory behavior (TB). TB was different in both systems and conditions of heat stress (p < 0.05), with 4.06 in CVS and 3.81 h in SPS in the intense heat stress period, while it was 2.91 and 1.08 h for SPS and CVS, respectively, during the moderate heat stress period. The wallowing activity showed statistically significant differences (p < 0.05) in the intense heat stress season with 1.18 and 2.35 h for SPS and CVS, respectively. Time spent on feeding behavior was highest in the SPS system (p < 0.05). Longer times of thermoregulatory and feeding behavior indicate the importance of trees in animal welfare for this species in tropical conditions, thus supporting avoided deforestation and the replanting of trees in existing production systems and landscapes

The dynamics of radial sap flux density reflects changes in stomatal conductance in response to soil and air water deficit

10 páginas.-- 7 figuras.-- 1 tabla.-- 53 referenciasWater scarcity in semiarid regions of Europe threatens the sustainability of fruit tree orchards unless irrigation water is optimized and scheduled in deficit irrigation strategies. Stomatal conductance (gs) is one of the best indicators of plant water stress, since it is placed in the crossroad between water and CO2 fluxes at the leaf level. Unfortunately, it is not possible to measure gs automatically and continuously, which reduces its potential for irrigation scheduling. In this work we examined the use of sap flux density (Js) in the outer rings of the sapwood of olive trees as a surrogate of gs. The working hypothesis was that as olive trees are well-coupled to atmosphere because of their small leaves, the ratio of Js to air vapor pressure deficit (D) should correlate well with the dynamics of gs in the canopy. It was also expected that current year, sun exposed leaves were mainly connected to the outer rings of the sapwood, and the oldest, shaded leaves to the inner rings. This was tested by measuring gs in new, sun-exposed leaves vs gs in old, shaded leaves. Both hypotheses were contrasted and our results confirmed that gs can be estimated from Js/D (R2 of the relationships were always higher than 0.8). A wide range of estimated gs values (0.350-0.025molm-2s-1) were derived from Js measurements in an olive orchard under three different irrigation regimes. Results were satisfactory and open the possibility of applying this method to estimate gs and use it either as a reliable water stress indicator or in transpiration and photosynthesis models applied to fruit tree orchards under a wide range of water stress conditions.This experiment was funded by the Spanish Ministry of Science and Innovation, research project AGL2009-11310/AGR and by the Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía (research project AGR-6456). Dr. Hernandez-Santana benefited from a Juan de la Cierva postdoctoral research fellowship from the Spanish Ministry of Science and Innovation. Thanks are due to the owners of Internacional Olivarera, S.A.U. (Interoliva), for allowing us to make the experiments in the Sanabria orchard.Peer reviewe

Hypertension in Women of Reproductive Age in the United States: NHANES 1999-2008

Objective: To examine the epidemiology of hypertension in women of reproductive age. Methods: Using NHANES from 1999–2008, we identified 5,521 women age 20–44 years old. Hypertension status was determined using blood pressure measurements and/or self-reported medication use. Results: The estimated prevalence of hypertension in women of reproductive age was 7.7% (95% confidence interval (CI): 6.9%–8.5%). The prevalence of anti-hypertensive pharmacologic therapy was 4.2% (95% CI 3.5%–4.9%). The prevalence of hypertension was relatively stable across the study period; the age and race adjusted odds of hypertension in 2007–2008 did not differ significantly from 1999–2000 (odds ratio 1.2, CI 0.8 to 1.7, p = 0.45). Significant independent risk factors associated with hypertension included older age, non-Hispanic black race (compared to non-Hispanic whites), diabetes mellitus, chronic kidney disease, and higher body mass index. The most commonly used antihypertensive medications included diuretics, angiotensin-converting enzyme inhibitors (ACE), and beta blockers. Conclusion: Hypertension occurs in about 8% of women of reproductive age. There are remarkable differences in the prevalence of hypertension between racial/ethnic groups. Obesity is a risk factor of particular importance in this population because it affects over 30% of young women in the U.S., is associated with more than 4 fold increased risk of hypertension, and is potentially modifiable

Palaeoenvironments, relative sea-level changes and tectonic influence on the Quaternary seismic units of the Huelva continental shelf (Gulf of Cadiz, southwestern Iberian Peninsula)

A seismic stratigraphical study was conducted on the Huelva continental shelf (southwestern Iberian Peninsula) between the mouths of the Guadalquivir and Guadiana Rivers. Applying the basic concepts of seismic stratigraphy, 13 seismic units bound by erosive discontinuities have been identified. Two main kinds of seismic units can be distinguished: a) Units that internally show a wide variability of seismic configurations and sheet to lensoidal external shape, located in inner-to-middle shelf settings. These units are considered high-energy units (HEU), deposited during intervals of rising and highstand sea levels. They represent coastal deposits comprising two main depositional systems: coastal barriers in the form of shoreface deposits and landward lagoonal and tidal deposits. b) Units displaying low-angle oblique seismic configurations, with reflectors exhibiting good lateral continuity and amplitude. Their thickness increases seaward, with the largest depocentres located near the shelf-break, displaying therefore a typical wedge external shape. These units are located very frequently from middle shelf emplacements to outer shelf and upper slope settings, and are considered low-energy units (LEU). They are believed to have been formed during periods of falling sea level, representing the distal portions of coastal and deltaic bodies that have been preserved from erosion. The stacking pattern of the units shows three different tectonic settings: a central subsiding sector, bounded laterally by two tectonic highs, one of them structurally controlled (the western one) and the other conditioned by diapiric uplifting (the eastern one).Un análisis de estratigrafía sísmica se ha realizado en la plataforma continental de Huelva (suroeste de la península Ibérica) entre las desembocaduras de los ríos Guadiana y Guadalquivir. Aplicando los concep tos básicos de la estratigrafía sísmica, han sido identificadas 13 unidades sísmicas limitadas por discontinuidades erosivas. Dos tipos principales de unidades sísmicas han sido identificadas: a) Unidades que internamente muestran una gran variabilidad de facies sísmicas y forma externa de lámina o lenticular, localizadas en la plataforma interna-media. Estas unidades son consideradas de alta energía (high- energy units, HEU), depositadas durante intervalos de ascenso y alto nivel del mar. Se relacionan con depósitos costeros compuestos de dos sistemas deposicionales principales: barreras costeras formadas por depósitos de frente de playa y, hacia tierra, depósitos mareales y de laguna. b) Unidades caracterizadas por clinoformas progradacionales de bajo ángulo, con reflectores de alta amplitud y continuidad. Su espesor aumenta hacia el borde de plataforma, adquiriendo una forma típica de cuña. Estas unidades están localizadas frecuentemente desde la plataforma media hasta el talud superior y son consideradas como unidades de baja energía (low-energy units, LEU). Se interpreta que representan las porciones distales de cuerpos costeros y deltaicos que se han formado durante periodos de descenso relativo del nivel del mar, y que han sido preservadas de la erosión que sufrieron las capas más someras. El patrón de apilamiento de las unidades muestra tres emplazamientos tectónicos diferentes: un sector central subsidente limitado lateralmente por dos altos tectónicos, uno controlado estructuralmente (sector oeste) y otro condicionado por un levantamiento de origen diapírico (sector este).Instituto Español de Oceanografí