El papel facilitador o inhibidor de Pinus Pinea L. Sobre especies autóctonas de matorral mediterráneo

Tesis descargada desde TESEONegative and positive interactions operate simultaneously in plant communities and the balance between these two forces drives community structure and function. Mediterranean sand dune ecosystems are nutrient-poor systems in which vegetation is composed mainly by Pinus pinea L., Juniperus phoenicea L., Osyris lanceolata Hochst. & Steud. and several shrubs belonging to the Cistaceae. P. pinea, due to its abundance and size, is known to interact with the rest of the species. With these assumptions we investigated the possible impacts of P. pinea on several aspects: (1) seed germination and seedling performance of three Mediterranean shrubs (Cistaceae family), (2) study of the decomposition processes of various life forms at the study site, (3) intensity of competition between seedlings of P. pinea, C. salvifolius and P. lentiscus under different combinations and nutrient treatments in order to evaluate the different behavior under nutrient-rich or poor conditions and (4) evaluate the special relationship between O. lanceolata, a hemiparasitic dioecious shrub and P. pinea. A thin needle layer could improve seed germination and seedling performance of shrub species due to the maintenance of a safe site and supplying some nutrients. These same needles may retard decomposition processes, but the presence of O. lanceolata litter in the soil enhances litter decomposition by releasing nutrients and enhancing litter decay rates of other species. A well-developed root system allows P. pinea to cope with the rest of the species and morphological traits are more important in predicting changes in competition than ecophysiological traits. This doctoral thesis highlights the important role played by O. lanceolata, not only in the nutrient cycling, but also spreading at the study site due to the presence of a good host, P. pinea

Reliance on deep soil water in the tree species Argania spinosa

In South-western Morocco, water scarcity and high temperature are the main factors determining species survival. Argania spinosa (L.) Skeels is a tree species, endemic to Morocco, which is suffering from ongoing habitat shrinkage. Argan trees play essential local ecological and economic roles: protecting soils from erosion, shading different types of crops, helping maintain soil fertility and, even more importantly, its seeds are used by the local population for oil production, with valuable nutritional, medicinal and cosmetic purposes. The main objective of this study was to identify the sources of water used by this species and to assess the effect of water availability on the photosynthetic rate and stem water potential in two populations: one growing on the coast and a second one 10 km inland. Stem water potential, photosynthetic rate and xylem water isotopic composition (δ18O) were seasonally monitored during 2 years. Trees from both populations showed a similar strategy in the use of the available water sources, which was strongly dependent on deep soil water throughout the year. Nevertheless, during the wet season or under low precipitation a more complex water uptake pattern was found with a mixture of water sources, including precipitation and soil at different depths. No evidence was found of the use of either groundwater or atmospheric water in this species. Despite the similar water-use strategy, the results indicate that Argania trees from the inland population explored deeper layers than coastal ones as suggested by more depleted δ18O values recorded in the inland trees and better photosynthetic performance, hence suggesting that the coastal population of A. spinosa could be subjected to higher stress

Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

Some secrets of Argania spinosa water economy in a semiarid climate

Argania spinosa is an example of an avoider tree growing under semi-arid conditions in Morocco. To assess what are the physiological strategies of this species, different variables were measured through an annual cycle in two populations located in the species’ main distribution area. Results show the expected decrease of leaf water potential (Ψ) with an increase of water-use efficiency (A/gs) with the onset of the dry season. In summer, leaf conductance (gs) was sensitive to vapour pressure deficit (VPD), and stomatal closure occurred over 30 mbar of VPD. Surprisingly, carbon isotope discrimination (δ13C) maintained very low values over the year, with almost no relationship with any physiological or morphological variable. Hence Argania spinosa presents a complex set of mechanisms to avoid water deficit, but δ13C cannot be used as an ecological tracer of long term WUE

Efectos potenciales del cambio global en la fisiología de los pingüinos antárticos

Barbosa, Andrés ... et. al.-- IX Simposio de Estudios Polares del Comité Español del Scientific Committee on Antarctic Research (SCAR), 5-7 September 2018, Madrid, España.-- 1 pageEl cambio global es uno de los factores ambientales más notables en la Península Antártica. Entre los distintos componentes que lo determinan se encuentra el cambio climático, la contaminación y la introducción de especies invasoras. En las últimas décadas la variación de las temperaturas ha producido profundos cambios ambientales tanto en el medio físico como en la biota de esta región. Los pingüinos antárticos constituyen el 80% de la biomasa de vertebrados del ecosistema antártico y junto con su posición en la parte alta de la cadena trófica les confiere el papel de centinelas del ecosistema al reflejar en su biología muchos de los cambios que se producen en el ambiente. Durante los últimos 15 años se están desarrollando un conjunto de proyectos dentro del macroproyecto PINGUCLIM cuyos objetivos están dirigidos a identificar los posibles efectos que el cambio global puede producir en la fisiología de los pingüinos antárticos. Paraello se ha llevado a cabo una aproximación a tres escalas, una a largo plazo para determinar dichos potenciales efectos, otra a corto plazo para la descripción de información básica y la identificación de los mecanismos que puedan explicar dichos efectos,y una geográfica que aprovechando las diferencias ambientales existentes a lo largo de la península antártica permita entender los cambios esperables. Con toda la información obtenida se ha construido un marco de efectos potenciales en cascada que relaciona los cambios ambientales ya producidos o esperables con distintos aspectos de la biología de los pingüinos. En esta comunicación se presentarán los resultados obtenidos a lo largo de estos años en aspectos tales como la dieta, ingestión de componentes esenciales como antioxidantes, presencia y efectos de parásitos/patógenos, respuesta inmunitaria, estrés oxidativo, presencia y efectos de contaminantesPeer Reviewe

Mode of attachment and pathology caused by Parorchites zederi in three species of penguins: Pygoscelis papua, Pygoscelis adeliae, and Pygoscelis antarctica in Antarctica

We identified and compared gross and microscopic lesions associated with the cestode, Parorchites zederi, in the digestive tracts of three species of penguins (Spheniscidae): the Chinstrap (Pygoscelis antarctica), Gentoo (Pygoscelis papua), and Adélie penguins (Pygoscelis adeliae). The gastrointestinal tracts of 79 recently dead individuals (71 chicks and eight adults) were collected in locations throughout the Antarctic Peninsula during summer field trips in 2006–09. Parorchites zederi was found in the small intestine of 37 animals (47%), and 23 (62%) of these had parasite-associated lesions. The cestodes were either free in the intestinal lumen, clustered within mucosal ulcers, or deeply embedded in the intestinal wall. Histopathologic changes were most severe in adult Gentoo Penguins and included transmural fibrogranulomatous enteritis, hemorrhage, and edema. This report of pathology associated with P. zederi in the digestive tracts of penguins can serve as reference to monitor health in Antarctic birds associated with environmental changes.Peer Reviewe

Caracterización de la investigación, el desarrollo tecnológico y la innovación en el sector productivo de la región fronteriza colombo venezolana. Volumen 2

En este libro en su segundo volumen, se presenta la recopilación de proyectos de Investigación e Innovación Tecnológica como resultado del desarrollo de actividades investigativas, en las cuales se involucran grupos de investigación y semilleros, instructores investigadores, docentes universitarios, administrativos, aprendices, estudiantes universitarios y empresarios del ámbito regional, nacional e internacional, quienes motivados por su espíritu emprendedor e innovador le apostaron a involucrarse en proyectos desde las áreas de automatización, electrónica y telecomunicaciones, gestión del hábitat, Diseño e implementación de soluciones en TIC, Gestión del negocio emprendimiento y empresarismo, Innovación educativa y Diseño de vestuario.In this book in its second volume, the compilation of Research and Technological Innovation projects is presented as a result of the development of research activities, in which research groups and seedbeds, research instructors, university teachers, administrators, apprentices, university students are involved. and regional, national and international entrepreneurs, who, motivated by his entrepreneurial and innovative spirit, bet him to get involved in projects from the areas of automation, electronics and telecommunications, habitat management, Design and implementation of ICT solutions, Entrepreneurship business management and entrepreneurship, educational innovation and costume design.Desarrollo de un sistema de información para los laboratorios de servicios tecnológicos basado en normatividad ISO/IEC 7025:2017 -- Implementación de tecnologías de realidad aumentada para mejorar el proceso de enseñanza aprendizaje de las operaciones logísticas de almacenamiento -- Automatización de un sistema hidropónico para la optimización de la producción de hortalizas de hoja -- Desarrollo y control de posicionamiento de un seguidor solar por seguimiento de carta solar y por maximo punto de radiación solar por lógica difusa -- Diseño de un sistema de control cinemático con open-hardware del manipulador didáctico pegasus amatrol -- Diseño de un sistema fotovoltaico híbrido grid-tied con respaldo de baterías para iluminación -- Implementación de un banco para la detección de fallas en motores trifásicos con inteligencia artificial -- Oilmaster dispositivo de detección de fallo en el sistema de lubricación en motocicletas -- Regulador de carga para picocentral hidroeléctrica -- Diseño de un sistema de percepción del impacto de choques mecánicos y golpes en el cerebro -- Crema humectante antiedad con principios activos naturales y subproductos del coee “silverskin” en sena, antioquia -- Formulación de barra de cereal partir de los subproductos del café, cacao, y sacha inchi -- Videojuego en realidad virtual como estrategia de formación para organización de eventos -- Fortalecimiento de las industrias culturales de dulces típicos en montería - departamento de córdobana199 página