Estimación de la velocidad de flujo del agua en cauces efímeros no aforados a partir de datos Lidar y GPS-RTK

The Manning formula is one of the most used to calculate the average velocity of water flow in ungauged channels. In order to be applied, it is necessary to measure in field the hydraulic radius (RH), the slope of the water surface (S), and to obtain the roughness coefficient (n), usually through tables created for this purpose. This involves a difficult, inefficient and subjective data collection in the field. This study evaluates the possibility to obtain these parameters in a more efficient manner, reducing the time of the process and allowing to work in larger areas. To achieve these objectives, the data used in this work were: 1) digital terrain models generated from airborne LiDAR data with a density of 2 points/ m2 , acquired when the channel was dry; 2) the height of the waterline and channel geometry measurements in the field using GPS; 3) Flow measurements. With this information, the velocity (Ve) was estimated and related to the average velocity of water flow (Vc) calculated from data measured in the field. The coefficient of determination between both velocity values was 73.52%, suggesting that the proposed methodology is useful to obtain the average velocity of flow, especially in remote areas or dry riverbeds

Assessment of satellite-derived shorelines automatically extracted from Sentinel-2 imagery using SAET

The definition of the shoreline position from satellite imagery is of great interest among coastal monitoring techniques. Understanding the reality mapped by the resulting shorelines and defining their accuracy is of paramount importance. The assessment described in this paper constitutes a validation of the shorelines obtained by using the novel tool SAET (Shoreline Analysis and Extraction Tool) for automatic shoreline extraction. The resulting shorelines applying the different parameters available in SAET are assessed in 9 test sites with diverse morphology and oceanographic conditions along the Atlantic European and Western Mediterranean coasts. The reference data is obtained along large coastal segments (covering up to about 240 km) from nearly coincident very high-resolution satellite images. Different image processing levels and extraction methods have been tested, showing their key role in the accuracy of shoreline position. When defining the approximate shoreline position the Automated Water Extraction Index for images without shadows (AWEInsh) with a 0 threshold generally constitutes the best segmentation method. In turn, the employment of the mathematical morphological operations of dilation or erosion considerably improves the results in certain coastal typologies. On the contrary, the employment of atmospherically-corrected images has a smaller influence on the accuracy of the SDSs. Results support the idea that the magnitude of the errors is strongly related to the specific coastal conditions- In general, the lowest errors appear in low-energetic microtidal sites, contrary to the energetic and mesotidal coasts with gentle slopes. The shoreline errors range between 3.7 m and 13.5 m RMSE (root-mean-square error) among the different coastal types when selecting the most appropriate extraction parameters. The shoreline position identified with SAET shows a similar or better accuracy to that obtained by other tools

Las costas rocosas del Migjorn de Menorca: acantilados y calas

[spa]La zona meridional de Menorca (Migjorn) se caracteriza por ser una plataforma carbonatada desarrollada en un ambiente arrecifal durante el Mioceno superior. Está surcada por una serie de cursos torrenciales fuertemente encajados que en su desembocadura al mar dan lugar a una forma de bahía denominada “cala” que está delimitada por paredes de elevada pendiente. La fracturación y la diaclasación penetrativa que afecta a la alternancia de materiales calcareníticos y calcisiltiticos miocenos, junto con la distribución de éstos, es el principal factor que condiciona el trazado de los cursos fluviales, así como el desarrollo de los procesos de tipo kárstico asociados a la circulación preferencial y la formación de conductos. La interacción en la zona litoral de los procesos endokársticos, en los cuales la mezcla de aguas favorece los procesos de disolución, la actividad torrencial, así como la dinámica marina –teniendo presente la variabilidad glacio-eustàtica acontecida durante el Cuaternario– favorece el desarrollo y dinamismo del propio karst (i.e. colapso de cavidades, formación de dolinas, etc.) lo que se traduce, finalmente, en la configuración de la geoforma tan característica y compleja que es la cala.[eng]The southern region of Menorca –Migjorn– is built up by a carbonate platform developed in a reef environment during the Upper Miocene. This structural platform is dissected by a set of canyon-like creeks that when reach the coast result in narrow and cliffy bays known as “cala”. Joints and penetrative fractures that affect the Upper Miocene calcarenites and calcilutites rock outcroups exert the main control of the streams pathway and direction. Karst processes also play a critical contribution related to the preferential circulation and void formation. The interaction at the coast between marine and endokarstic processes –where mixing zone waters enhance rock solution–, between the fluvial processes and sea level (including sea level fluctuations during Quaternary times– enhance the dynamics and the development of karst (i.e. cave collapse, dolines formation, etc.) and this, finally, results in the configuration of a very representative rock coast macroform such as the “cala”

Karst, acantilados y calas en el Migjorn de Menorca

[spa]La costa sur de la isla de Menorca se caracteriza por la presencia, de forma más o menos continua, de acantilados verticales cortados en los depósitos carbonatados que constituyen una plataforma atribuida al Mioceno superior. Los acantilados se encuentran interrumpidos en la zona litoral por una marcada incisión producida por los barrancos que drenan toda la plataforma miocena del sur de la isla y que, en su desembocadura al mar, dan lugar a las denominadas calas. La forma de éstas viene controlada no tan sólo por la fracturación, que a su vez controla la red de drenaje, sino que también por la contribución de los procesos kársticos que están directamente relacionados con la zona de mezcla de aguas en los acuíferos litorales. La acción de la dinámica marina y en especial la oscilación del nivel marino durante el Cuaternario también participan en la configuración de la morfología de la calas. Las paredes verticales y un fondo plano debido al relleno sedimentario de las zonas inundadas por el nivel del mar durante el Holoceno son otras de sus características básicas.[eng]A continuous cliffy coast built up by a carbonate platform developed in a reef environment during the Upper Miocene characterizes the southern region –Migjorn– of Menorca. This structural platform is dissected by a set of canyon-like creeks that when reach the coast result in narrow and cliffy bays known as “cala”. The cala morphology, as well as the fluvial network with a preferential N-S orientation–, is controlled mainly by fractures but also by the karstic processes that are dominant in the area. These processes are related with the mixing zone water interference in coastal aquifers. The marine action is also quite important, since sea-level oscillation during Quaternary, the shape and attributes of calas were modified, and the sedimentary infilling related with the Holocene inundation, resulted in a flat floor that contrasts with the cliffy sides of the calas

The relationship between transgenerational acquired resistance and global DNA methylation in Arabidopsis

Progeny of heavily diseased plants develop transgenerational acquired resistance (TAR). In Arabidopsis, TAR can be transmitted over one stress-free generation. Although DNA methylation has been implicated in the regulation of TAR, the relationship between TAR and global DNA methylation remains unknown. Here, we characterised the methylome of TAR-expressing Arabidopsis at different generations after disease exposure. Global clustering of cytosine methylation revealed TAR-related patterns in the F3 generation, but not in the F1 generation. The majority of differentially methylated positions (DMPs) occurred at CG context in gene bodies. TAR in F3 progeny after one initial generation of disease, followed by two stress-free generations, was lower than TAR in F3 progeny after three successive generations of disease. This difference in TAR effectiveness was proportional to the intensity of differential methylation at a sub-set of cytosine positions. Comparison of TAR-related DMPs with previously characterised cytosine methylation in mutation accumulation lines revealed that ancestral disease stress preferentially acts on methylation-labile cytosine positions, but also extends to methylation-stable positions. Thus, the TAR-related impact of ancestral disease extends beyond stochastic variation in DNA methylation. Our study has shown that the Arabidopsis epigenome responds globally to disease in previous generations and we discuss its contribution to TAR

A Technical Solution to Allow Off-line Mobile Map Querying of Discrete and Continuous Geographic Attribute Data

In this article, a technique towards the generation of hybrid raster-attributes map for use in mobile devices is described. Our solution is based on coding the map attributes within an image using RGB values. The designed coding method enables the simultaneous storage of discrete thematic attributes and continuous quantitative attributes. This approach offers a wide range of possible uses. Small memory storage requirements and the simplicity of the software enable this coding method to be used efficiently in mobile devices without Internet connection. This article describes the basic fundamentals of the coding technique, as well as the operation and limitations regarding the volume of information. Two specific applications are presented: a topographic map used for recreational activities, and a visitor map of a university campus.Palomar-Vázquez, J.; Pardo Pascual, JE.; Sebastiá Tarín, L.; Recio Recio, JA. (2012). A Technical Solution to Allow Off-line Mobile Map Querying of Discrete and Continuous Geographic Attribute Data. Cartographic Journal. 49(2):143-152. doi:10.1179/1743277411Y.0000000029S14315249

Spatial Guilds in the Serengeti Food Web Revealed by a Bayesian Group Model

Food webs, networks of feeding relationships among organisms, provide fundamental insights into mechanisms that determine ecosystem stability and persistence. Despite long-standing interest in the compartmental structure of food webs, past network analyses of food webs have been constrained by a standard definition of compartments, or modules, that requires many links within compartments and few links between them. Empirical analyses have been further limited by low-resolution data for primary producers. In this paper, we present a Bayesian computational method for identifying group structure in food webs using a flexible definition of a group that can describe both functional roles and standard compartments. The Serengeti ecosystem provides an opportunity to examine structure in a newly compiled food web that includes species-level resolution among plants, allowing us to address whether groups in the food web correspond to tightly-connected compartments or functional groups, and whether network structure reflects spatial or trophic organization, or a combination of the two. We have compiled the major mammalian and plant components of the Serengeti food web from published literature, and we infer its group structure using our method. We find that network structure corresponds to spatially distinct plant groups coupled at higher trophic levels by groups of herbivores, which are in turn coupled by carnivore groups. Thus the group structure of the Serengeti web represents a mixture of trophic guild structure and spatial patterns, in contrast to the standard compartments typically identified in ecological networks. From data consisting only of nodes and links, the group structure that emerges supports recent ideas on spatial coupling and energy channels in ecosystems that have been proposed as important for persistence.Comment: 28 pages, 6 figures (+ 3 supporting), 2 tables (+ 4 supporting

Guía clínica de la enfermedad de Pompe de inicio tardío

Hasta 2006, la enfermedad de Pompe o glucogenosis tipo II era una enfermedad incurable y con tratamiento meramente paliativo. El desarrollo de la terapia de sustitución con la enzima α-glucosidasa recombinante humana ha constituido el primer tratamiento específico para esta enfermedad. El objetivo de esta guía es servir de referencia en el manejo de la variedad de inicio tardío de la enfermedad de Pompe, es decir, la que aparece después del primer año de vida. En la guía, un grupo de expertos españoles hace recomendaciones específicas en cuanto a diagnóstico, seguimiento y tratamiento de esta enfermedad. En cuanto al diagnóstico, el método de la muestra en sangre seca es imprescindible como primer paso para el diagnóstico de la enfermedad de Pompe, y el diagnóstico de confirmación de la enfermedad de Pompe debe realizarse mediante un estudio de la actividad enzimática en muestra líquida en linfocitos aislados o mediante el análisis mutacional del gen de la alfa-glucosidasa. En cuanto al tratamiento de la enfermedad con terapia de sustitución enzimática, los expertos afirman que es eficaz en la mejoría o estabilización de la función motora y pulmonar, y debe iniciarse cuando aparezcan los síntomas atribuibles a la enfermedad de Pompe.

Autoantibody screening in Guillain-Barré syndrome

Background: Guillain?Barré syndrome (GBS) is an acute inflammatory neuropathy with a heterogeneous presentation. Although some evidences support the role of autoantibodies in its pathogenesis, the target antigens remain unknown in a substantial proportion of GBS patients. The objective of this study is to screen for autoantibodies targeting peripheral nerve components in Guillain-Barré syndrome. Methods: Autoantibody screening was performed in serum samples from all GBS patients included in the International GBS Outcome study by 11 different Spanish centres. The screening included testing for anti-ganglioside antibodies, anti-nodo/paranodal antibodies, immunocytochemistry on neuroblastoma-derived human motor neurons and murine dorsal root ganglia (DRG) neurons, and immunohistochemistry on monkey peripheral nerve sections. We analysed the staining patterns of patients and controls. The prognostic value of anti-ganglioside antibodies was also analysed. Results: None of the GBS patients (n = 100) reacted against the nodo/paranodal proteins tested, and 61 (61%) were positive for, at least, one anti-ganglioside antibody. GBS sera reacted strongly against DRG neurons more frequently than controls both with IgG (6% vs 0%; p = 0.03) and IgM (11% vs 2.2%; p = 0.02) immunodetection. No differences were observed in the proportion of patients reacting against neuroblastoma-derived human motor neurons. Reactivity against monkey nerve tissue was frequently detected both in patients and controls, but specific patterns were only detected in GBS patients: IgG from 13 (13%) patients reacted strongly against Schwann cells. Finally, we confirmed that IgG anti-GM1 antibodies are associated with poorer outcomes independently of other known prognostic factor

Autoantibody screening in Guillain-Barré syndrome

Background: Guillain-Barré syndrome (GBS) is an acute inflammatory neuropathy with a heterogeneous presentation. Although some evidences support the role of autoantibodies in its pathogenesis, the target antigens remain unknown in a substantial proportion of GBS patients. The objective of this study is to screen for autoantibodies targeting peripheral nerve components in Guillain-Barré syndrome. Methods: Autoantibody screening was performed in serum samples from all GBS patients included in the International GBS Outcome study by 11 different Spanish centres. The screening included testing for anti-ganglioside antibodies, anti-nodo/paranodal antibodies, immunocytochemistry on neuroblastoma-derived human motor neurons and murine dorsal root ganglia (DRG) neurons, and immunohistochemistry on monkey peripheral nerve sections. We analysed the staining patterns of patients and controls. The prognostic value of anti-ganglioside antibodies was also analysed. Results: None of the GBS patients (n = 100) reacted against the nodo/paranodal proteins tested, and 61 (61%) were positive for, at least, one anti-ganglioside antibody. GBS sera reacted strongly against DRG neurons more frequently than controls both with IgG (6% vs 0%; p = 0.03) and IgM (11% vs 2.2%; p = 0.02) immunodetection. No differences were observed in the proportion of patients reacting against neuroblastoma-derived human motor neurons. Reactivity against monkey nerve tissue was frequently detected both in patients and controls, but specific patterns were only detected in GBS patients: IgG from 13 (13%) patients reacted strongly against Schwann cells. Finally, we confirmed that IgG anti-GM1 antibodies are associated with poorer outcomes independently of other known prognostic factors. Conclusion: Our study confirms that (1) GBS patients display a heterogeneous repertoire of autoantibodies targeting nerve cells and structures; (2) gangliosides are the most frequent antigens in GBS patients and have a prognostic value; (3) further antigen-discovery experiments may elucidate other potential antigens in GBS