34 research outputs found
The Use of Unmanned Aerial Vehicles (UAVs) for Estimating Soil Volumes Retained by Check Dams after Wildfires in Mediterranean Forests
Check dams act as soil collectors during floods, thus retaining a large amount of sediments. The estimation of the soil volumes stored behind a check dam is a key activity for a proper design of these control works and for evaluation of soil delivery after restoration measures at watershed level. Several topographic techniques have been proposed for this activity, but the sediment wedge mapping tools are complex and time consuming. Conversely, the use of unmanned aerial vehicles (UAVs) has been proposed to support aerophotogrammetric techniques for several survey activities with promising results. However, surveys by UAVs have never applied to calculate the size of the sediment wedge behind check dams that are built in fire-affected watersheds, where soil loss and sediment transport may be high after a wildfire. To fill this gap, this study evaluates the efficiency and efficacy of aerophotogrammetric surveys using UAVs to estimate the volume of the sediments stored behind ten check dams, built as post-fire channel treatment in a forest watershed of Castilla La Mancha (Central Eastern Spain). The results of the aerophotogrammetric technique were compared to traditional topographic surveys using a total station and GNSS/RTK, assumed as reference. The estimation of sediment wedge volume provided by UAVs was more accurate (mean RMSE of 0.432), extensive (density of mapped points of 328 m−2) and quick (two days of fieldwork) compared to surveys using the topographic method (RMSE < 0.04 m, six days of field work and density of mapped points of 0.194 m−2) by the topographic method. The differences in the sediment volume estimated by the two methods were not significant, but the UAV method was more accurate for the larger check dams. Moreover, a significant correlation was observed between the volume estimates provided by the two methods, shown by a coefficient of determination close to 0.98. Overall, these results propose a larger use of the aerial surveys for mapping activities in channels regulated by check dams, such as those built for restoration of fire-affected forest watersheds
Post-fire Management Effects on Sediment (Dis)Connectivity in Mediterranean Forest Ecosystems: Channel and Catchment Response
[Abstract] Forest fires and post-fire practices influence sediment connectivity (SC). In this study, we use the ‘aggregated index of connectivity’ (AIC) to assess SC in five Mediterranean catchments (198–1090 ha) affected by a wildfire in 2012 in south-eastern Spain. Two temporal scenarios were considered, immediately after the fire and before post-fire management, and 2 years after the fire including all practices (hillslope barriers, check-dams, afforestation, salvage logging and skid trails). One LiDAR (light detection and ranging)-derived digital elevation model (DEM, 2 m × 2 m resolution) was generated, per scenario. The five catchment outlets were established as the computation target (AICоᴜᴛ), and structural and functional SC were calculated. Index outputs were normalized to make the results of the non-nested catchments comparable (AICɴ₋оᴜᴛ). The output analysis includes the SC distribution along the catchments and at local scale (929 sub-catchments, 677 in the burned area), the hillslope and channel measures' effect on SC, and a sedimentological analysis using observed area-specific sediment yield (SSY) at 10 new (built after post-fire practices) concrete check-dams located in the catchments (SSY = 1.94 Mg ha⁻¹ yr⁻¹; σ = 1.22). The catchments with more circular shapes and steeper slopes were those with higher AICɴ₋оᴜᴛ. The structural SC maps – removing the rainfall erosivity influence – allowed evaluating the actual role played by the post-fire practices that reduced SC (x̅ = − 1.19%; σ = 0.41); while functional SC was linked to the actual change of SC (x̅ = + 5.32%; σ = 0.62). Hillslope treatments resulted in significant changes on AICɴ₋оᴜᴛ at sub-catchment scale with certain disconnectivity. A good and positive correlation was found between the SSY and the changes of AICɴ₋оᴜᴛ. However, the coarse DEM resolution explained the lack of effect of the rock check-dams – located on the secondary channels – on AICɴ₋оᴜᴛ. AICɴ₋оᴜᴛ proved to be a useful tool for decision making in post-fire restoration, but an optimal input data is still necessary to refine calculations.European Cooperation in Science and Technology; CA18135Gobierno de Castilla-la Mancha; Sbply/16/180501/ 000109This study was supported by funds provided to the VIS4FIRE Spanish R&D project (RTA2017-00042-C05-00) co-funded by the “Instituto Nacional de Investigación y Tecnología Agraria” (INIA) and FEDER programme. This study was done in the frame of the European Cooperation in Science and Technology (COST) action CA18135 ‘FIRElinks’ (Fire in the Earth System:Science & Society). J. González-Romero holds a scholarship (Sbply/16/180501/000109) from the Regional Government of Castilla-La Mancha/European Social Fund (ESF, EU)
Post-fire Management Effects on Hillslope-Stream Sediment Connectivity in a Mediterranean Forest Ecosystem
[Abstract] Forest fires intensify sediment transport and aggravate local and off-site consequences of soil erosion. This study evaluates the influence of post-fire measures on structural and functional sediment connectivity (SC) in five fire-affected Mediterranean catchments, which include 929 sub-catchments, by using the “aggregated index of connectivity” (AIC) at two temporal scenarios: I) immediately after the fire and before implementing post-fire practices (‘Pre-man’), and II) two years after the fire (‘Post-man’). The latter includes all the emergency stabilization practices, that are hillslope barriers, check-dams and afforestation. The stream system was set as the target of the computation (STR), to be representative of intense rainfall-runoff events with effective sediment delivery outside the catchments. Output normalization (AICN) allows comparing the results of the five basins between them. The sedimentological analysis is based on specific sediment yield (SSY) –measured at the check-dams installed after the fire –, and this data is used for output evaluation. Stream density and slope variables were the most influential factors on AICN-STR results at the sub-catchment scale. Post-fire hillslope treatments (barriers when built in high densities and afforestation) significantly reduced AICN-STR in comparison with untreated areas in both structural and functional approaches. Despite the presence of hillslope treatments, the higher erosive rainfall conditions resulted in higher AICN-STR values in the Post-man scenario (functional approach). A positive and good correlation was found between the measured SSY and the AICN-STR changes due to the post-fire practices and vegetation recovery, showing the good correspondence of the computation results and the real sediment dynamics of the studied catchments. Overall, AICN demonstrated to be a useful and versatile tool for post-fire management, which needs further research to optimize its applicability.The authors thank the Regional Government of Castilla-La Mancha (Junta de Comunidades de Castilla-La Mancha) for supporting the study and providing information about the undertaken measures in the burned area. This study was supported by funds provided to the VIS4FIRE Spanish R&D project (RTA 2017-00042-C05-00) co-funded by the “Instituto Nacional de Investigación y Tecnología Agraria” (INIA) and FEDER programme. This study was done in the frame of the European Cooperation in Science and Technology (COST) action CA18135 ‘FIRElinks’ (Fire in the Earth System: Science & Society). J. González-Romero holds a postdoctoral contract supported by the European Social Fund (ESF, EU). The authors declare no conflict of interest. E. Peña holds a scholarship (2020-PREUCLM-16032) from the UCLM and the European Social Fund (FSE). Pedro Antonio Plaza Álvarez holds a predoctoral fellowship from the Spanish Ministry of Education, Culture and Sport (FPU16/03296)Universidad de Castilla-La Mancha; 2020-PREUCLM-1603
New aromatic polyamides and polyimides having an adamantine bulky group
Producción CientíficaThis paper reports the synthesis and characterization of a new rigid diamine monomer, having a spiro carbon moiety and an adamantane bulky group in its structure; namely spiro-(adamantane-2,9′(2',7'-diamino)-fluorene) (SADAF). After its synthesis, using a straightforward methodology, a novel family of aromatic polyimides (PIs) and polyamides (PAs) has been attained by reaction of SADAF with three aromatic dianhydrides and two diacid chlorides, respectively. Two of the polyimides were obtained through the formation of the corresponding polyamic acid and subsequent thermal cycloimidization, whereas the other one, the polyimide from SADAF and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), could be synthesized by chemical imidization from the polyamic precursor. Regarding polyamides, two new ones, made from SADAF and isophthaloyl chloride (IPC) and the diacid chloride of 2,2-bis(4-carboxyphenyl)hexafluoropropane (6FC) could be obtained. All the polymers showed high Tg, above 350 ºC, and excellent thermal resistance, with onset degradation temperatures higher than 450 ºC. Polymers formed by the combination of SADAF with 6FDA and 6FC were prepared as dense films with good mechanical properties and their permselectivity properties were measured.Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA302U13
International Consensus Document on Obstructive Sleep Apnea
El objetivo principal de este documento internacional de consenso sobre apnea obstructiva del sueno es proporcionar unas directrices que permitan a los profesionales sanitarios tomar las mejores decisiones en la asistencia de los pacientes adultos con esta enfermedad según un resumen crítico de la literatura más actualizada. El grupo de trabajo de expertos se ha constituido principalmente por 17 sociedades científicas y 56 especialistas con amplia representación geográfica (con la participación de 4 sociedades internacionales), además de un metodólogo experto y un documentalista del Centro Cochrane Iberoamer icano. El documento consta de un manuscrito principal, con las novedades más relevantes del DIC, y una serie de manuscritos online que recogen las búsquedas bibliográficas sistemáticas de cada uno de los apartados del DIC. Este documento no cubre la edad pediátrica ni el manejo del paciente en ventilación mecánica crónica no invasiva (que se publicarán en sendos documentos de consenso aparte)
Revisar y reescribir textos académicos con herramientas digitales para transformar el conocimiento en la formación del profesorado en la Universidad
La necesidad de proporcionar herramientas digitales para la docencia online eficaz nos lleva a continuar la investigación de la fase de revisión y reescritura de textos, con la finalidad de ofrecer recursos tecnológicos en la plataforma UCM-Redactext
Mosaic maternal ancestry in the Great Lakes region of East Africa
The Great Lakes lie within a region of East Africa with very high human genetic diversity, home of many ethno-linguistic groups usually assumed to be the product of a small number of major dispersals. However, our knowledge of these dispersals relies primarily on the inferences of historical, linguistics and oral traditions, with attempts to match up the archaeological evidence where possible. This is an obvious area to which archaeogenetics can contribute, yet Uganda, at the heart of these developments, has not been studied for mitochondrial DNA (mtDNA) variation. Here, we compare mtDNA lineages at this putative genetic crossroads across 409 representatives of the major language groups: Bantu speakers and Eastern and Western Nilotic speakers. We show that Uganda harbours one of the highest mtDNA diversities within and between linguistic groups, with the various groups significantly differentiated from each other. Despite an inferred linguistic origin in South Sudan, the data from the two Nilotic-speaking groups point to a much more complex history, involving not only possible dispersals from Sudan and the Horn but also large-scale assimilation of autochthonous lineages within East Africa and even Uganda itself. The Eastern Nilotic group also carries signals characteristic of West-Central Africa, primarily due to Bantu influence, whereas a much stronger signal in the Western Nilotic group suggests direct West-Central African ancestry. Bantu speakers share lineages with both Nilotic groups, and also harbour East African lineages not found in Western Nilotic speakers, likely due to assimilating indigenous populations since arriving in the region ~3000 years ago
Clinical guide of the Spanish Society of Nephrology on the prevention and treatment of peritoneal infection in peritoneal dialysis
[Resumen] Las infecciones peritoneales siguen constituyendo una complicación muy relevante de la diálisis peritoneal, por su incidencia todavía elevada y por sus importantes consecuencias clínicas, en términos de mortalidad, fracaso de la técnica y costes para el sistema sanitario. Las prácticas de prevención y tratamiento de esta complicación muestran una notable heterogeneidad derivada, entre otros factores, de la complejidad del problema y de la escasez de evidencia clínica que permitan responder de manera clara a muchas de las dudas planteadas. El propósito de este documento es proporcionar una revisión completa y actualizada de los métodos de diagnóstico, prevención y tratamiento de estas infecciones. El documento se ha elaborado tomando como referencia de partida la guía más reciente de la Sociedad Internacional de Diálisis Peritoneal (2016). Mientras que para el capítulo diagnóstico se ha adoptado una estructura más narrativa, el análisis de las medidas de prevención y tratamiento ha seguido una metodología sistemática (Grading of Recommendations, Assessment, Development and Evaluation [GRADE]), que especifica el nivel de evidencia y la fuerza de las sugerencias y recomendaciones propuestas, y facilita actualizaciones futuras de la guía. La gran extensión y numerosas recomendaciones o sugerencias emanadas de la revisión ponen de manifiesto la complejidad y gran número de facetas a tener en cuenta para un adecuado abordaje de esta importante complicación de la diálisis peritoneal.[Abstract] Peritoneal infections still represent a most feared complication of chronic peritoneal dialysis, due to their high incidence and relevant clinical consequences, including direct mortality, technique failure and a significant burden for the health system. The practices for prevention and treatment of this complication show a remarkable heterogeneity emerging, among other factors, from the complexity of the problem and from a paucity of quality evidence which could permit to respond clearly to many of the raised questions. The purpose of this document is to provide a complete and updated review of the main methods of diagnosis, prevention and treatment of these infections. The document has been elaborated taking as a reference the most recent guidelines of the International Society of Peritoneal Dialysis (2016). The diagnostic considerations are presented in a narrative style while, for prevention and therapy, we have used a systematic methodology (Grading of Recommendations, Assessment, Development and Evaluation [GRADE]), which specifies the level of evidence and the strength of the proposed suggestions and recommendations and facilitates future updates of the document. The length of the document and the many suggestions and recommendations coming out of the review underline the large number and the complexity of the factors to be taken into consideration for an adequate approach to this complication of peritoneal dialysis
Innovación en las enseñanzas universitarias: experiencias presentadas en las III Jornadas de Innovación Educativa de la ULL
En este libro se recoge un conjunto de experiencias de innovación educativa desarrolladas en la ULL en el curso 2011-12. Se abordan distintos ámbitos y ramas del conocimiento, y ocupan temáticas variadas que han sido desarrolladas con rigor, y con un claro potencial para su extrapolación a efectos de la mejora educativa en el ámbito universitario. Esta publicación constituye una primera
edición de una serie que irá recogiendo las experiencias de innovación educativa de la ULL. Este es un paso relevante para su impulso en nuestra institución, como lo es el de su vinculación con la investigación educativa, para potenciar
su publicación en las revistas científicas en este ámbito cada vez más pujante y relevante para las universidades. Sobre todo representan el deseo y el compromiso del profesorado de la ULL para la mejora del proceso educativo mediante
la investigación, la evaluación y la reflexión compartida de nuestras prácticas y planteamientos docentes