Sustitución de comunidades y concentración de nutrientes en plantas tras incendios forestales en una cuenca subárida del S.E. de España

Specific plant communities replacement in a subarid basin (Sierra de Almijara, S.E. Spain) is described related with internal concentration of C, N and compartimental P in several post-fire representative and dominant species. Plots were burnt 1, 6, 12 and 30 years before respectively, because fire is a recurrent phenomenon in that mediterranean shrublands. Juniperus oxycedrus is typical of the advanced stages of succession and presents low concentration of P and N, specially in old plants. Genista spartioides minimizes C:N ratio due to its symbiotic activity; and Cistus clusii shows an active cumulative metabolism specially in that concerning the phosphorus retention. In the frame of the general theory of sucession, C . clusii takes advantages of its ability to internalize high concentration of phosphate and Fabaceae of N accumulation. A dilution effect is detected in plants which are characteristic of the vegetation at the end of recolonization.Se describe la sustitución de comunidades tras incendios en una cuenca subárida (Sierra de Almijara, S.E. España), en relación con las concentraciones de carbono, nitrógeno y varios compartimentos de fósforo en tejidos de 5 especies de plantas representativas, en parcelas incendiadas hace 1, 6, 12 y 30 años respectivamente. El fuego se presenta de modo recurrente en estos matorrales mediterráneos. Juniperus oxycedrus, propia de formaciones de monte alto y de etapas avanzadas de la sucesión, presenta bajas concentraciones de P y N, especialmente en plantas viejas. Genista spartioides minimiza el indice C:N debido a su actividad simbiótica; y Cistus clusii muestra un activo metabolismo acumulador especialmente en lo que se refiere a la retención de fósforo. En el marco de la teoria general de la sucesión, C.clusii obtendria ventajas de su habilidad para internalizar altas concentraciones de fosfato y especies de la familia Fabaceae de su capacidad de acumulación de nitrógeno. En plantas caractensticas de las fases finales de la recolonización, se ha detectado un efecto de dilución de 10s nutrientes internos a medida que transcurre el tiempo tras el incendio

Catálogo florístico de la provincia de Málaga. l. Selaginellaceae-Ephedraceae

Este trabajo es el primero de una serie cuyo fin es la publicación del catálogo florístico completo de la provincia de Málaga. En esta primera nota se incluyen los datos recogidos sobre la provincia de Málaga en las especies comprendidas desde Selaginellaceae a Ephedraceae, así como una reseña histórica de las herborizaciones en la provincia. Las citas de especie van acompañadas de su localización en el retículo internacional U.T.M., las citas bibliográficas llevan su correspondiente reseña

New records and observations of macroalgae and associated pathogens from the Falkland Islands, Patagonia and Tierra del Fuego

Subantarctic and Antarctic regions remain little explored with regards to their seaweed diversity. This study is based upon collections in the early 1970s and 2007–2013. It is supported by sequencing COI (mitochondrial cytochrome oxidase I) and reports new records for four species of brown algae Hincksia granulosa, Hincksia sandriana, Myriotrichia clavaeformis, Syringoderma australe), four red algae (Erythrotrichia carnea, Paraglossum salicifolium, Phycodrys antarctica, Plumariopsis eatonii), one green alga (Chaetomorpha aerea) and of the oomycete Anisolpidium ectocarpii. A further four brown algae are reported at genus level and discussed (Cladostephus sp., Colpomenia sp., Dictyota sp., Punctaria sp.). Observations of the biology of three brown algal taxa (Cladothele decaisnei, Geminocarpus geminatus, Halopteris obovata) from the region are also reported here

Contribución al estudio del Omphalodion brassicaefoliae Rivas Martínez, S., Izco, J. & Costa, M., 1973 en el Sur de la Península Ibérica

En el presente trabajo, se comentan y confirman las comunidades ya descritas del Omphalodion brassicaefoliae siguientes, Jasiono -Linarietum saturejoidis y Arenario (capillipes)—lberidetum fontqueri. Asimismo se describen para esta alianza y para los mismos sectores corológicos las siguientes asociaciones nuevas, Violo lonopsidientum prolongoi typicum y linarietosum platyealicis. y Arenario (retusae)—Linarietum salzmannii.Dans le present travail, on fait un comentaire et on ratifie les suivantes communautés déjà decrites de l'Omphalodion brassicaefoliae-Linarietum saturejoidis et Arenario (capillipes)—lberidetum fontqueri.. On décrit tout de méme pour cette alliance et pour les mémes secteurs corologiques les nouvelles associations qui suivent, Violo lonopsidientum prolongoi typicum et linarietosum platyealicis. et Arenario (retusae)—Linarietum salzmannii

An alternative for reducing the layers in the construction of three-phase planar transformers

A modified winding layout for three-phase transformers with PCB windings is proposed in this paper. This modified layout can be used in high current transformers with many PCB layers to simplify the fabrication process. One of the key factors that might increase the cost and complexity in the construction of planar transformers is the number of layers of each PCB winding. This issue becomes even more important in medium-high power three-phase transformers, where the number of PCB layers is higher. In addition to that, the proposed method allows the use of commercial core shapes that are commonly used to design single-phase transformers. This fact makes possible the reduction of cost and flexibility of the design solutions. The proposed solution has been validated and compared using the conventional and the proposed methodologies to design a high power (20 kW) transformer

QR-Factorization Algorithm for Computed Tomography (CT): Comparison With FDK and Conjugate Gradient (CG) Algorithms

[EN] Even though QR-factorization of the system matrix for tomographic devices has been already used for medical imaging, to date, no satisfactory solution has been found for solving large linear systems, such as those used in computed tomography (CT) (in the order of 106 equations). In CT, the Feldkamp, Davis, and Kress back projection algorithm (FDK) and iterative methods like conjugate gradient (CG) are the standard methods used for image reconstruction. As the image reconstruction problem can be modeled by a large linear system of equations, QR-factorization of the system matrix could be used to solve this system. Current advances in computer science enable the use of direct methods for solving such a large linear system. The QR-factorization is a numerically stable direct method for solving linear systems of equations, which is beginning to emerge as an alternative to traditional methods, bringing together the best from traditional methods. QR-factorization was chosen because the core of the algorithm, from the computational cost point of view, is precalculated and stored only once for a given CT system, and from then on, each image reconstruction only involves a backward substitution process and the product of a vector by a matrix. Image quality assessment was performed comparing contrast to noise ratio and noise power spectrum; performances regarding sharpness were evaluated by the reconstruction of small structures using data measured from a small animal 3-D CT. Comparisons of QR-factorization with FDK and CG methods show that QR-factorization is able to reconstruct more detailed images for a fixed voxel size.This work was supported by the Spanish Government under Grant TEC2016-79884-C2 and Grant RTC-2016-5186-1.Rodríguez-Álvarez, M.; Sánchez, F.; Soriano Asensi, A.; Moliner Martínez, L.; Sánchez Góez, S.; Benlloch Baviera, JM. (2018). QR-Factorization Algorithm for Computed Tomography (CT): Comparison With FDK and Conjugate Gradient (CG) Algorithms. IEEE Transactions on Radiation and Plasma Medical Sciences. 2(5):459-469. https://doi.org/10.1109/TRPMS.2018.2843803S4594692

Optical analysis of textured plastic substrates to be used in thin silicon solar cells

Light confinement strategies in thin-film silicon solar cells play a crucial role in the performance of the devices. In this work, the possible use of Ag-coated stamped polymers as reflectors to be used in n-i-p solar cells is studied. Different random roughnesses (nanometer and micrometer size) have been transferred on poly(methylmethacrylate) (PMMA) by hot embossing. Morphological and optical analyses of masters, stamped polymers and reflectors have been carried out evidencing a positive surface transference on the polymer and the viability of a further application in solar cells

Seaweed biodiversity in the south-western Antarctic Peninsula: Surveying macroalgal community composition in the Adelaide Island / Marguerite Bay region over a 35-year time span

The diversity of seaweed species of the south-western Antarctic Peninsula region is poorly studied, contrasting with the substantial knowledge available for the northern parts of the Peninsula. However, this is a key region affected by contemporary climate change. Significant consequences of this change include sea ice recession, increased iceberg scouring and increased inputs of glacial melt water, all of which can have major impacts on benthic communities. We present a baseline seaweed species checklist for the southern Adelaide Island and northern Marguerite Bay region, combining data obtained during a small number of surveys completed in 1973–1975 and a 6-week intensive diving-based field campaign in 2010–2011. Overall, with a total of 41 macroalgal species recorded (7 brown, 27 red, 6 green, 1 chrysophyte), the region is species-poor compared to the north of the Antarctic Peninsula, and even more so in comparison with the sub-Antarctic. The key canopy-forming species is Desmarestia menziesii, which is abundant in Antarctic Peninsula waters, but lacking in the sub-Antarctic. Himantothallus grandifolius, which is a common species further north in the Antarctic phytobenthos, was absent in our recent collections. This paper also reports the first record of Aplanochytrium sp. (Labyrinthulomycetes) from this part of Antarctica and in association with Elachista sp

Progress in single junction microcrystalline silicon solar cells deposited by Hot-Wire CVD

Hot-Wire Chemical Vapor Deposition has led to microcrystalline silicon solar cell efficiencies similar to those obtained with Plasma Enhanced CVD. The light-induced degradation behavior of microcrystalline silicon solar cells critically depends on the properties of their active layer. In the regime close to the transition to amorphous growth (around 60% of amorphous volume fraction), cells incorporating an intrinsic layer with slightly higher crystalline fraction and [220] preferential orientation are stable after more than 7000 h of AM1.5 light soaking. On the contrary, solar cells whose intrinsic layer has a slightly lower crystalline fraction and random or [111] preferential orientation exhibit clear light-induced degradation effects. A revision of the efficiencies of Hot-Wire deposited microcrystalline silicon solar cells is presented and the potential efficiency of this technology is also evaluated

Arctic marine phytobenthos of northern Baffin Island

This project was supported by SAMS and NFSD core funding (Oceans 2025 WP 4.5 from the UK Natural Environment Research Council), the European Commission (ASSEMBLE, grant agreement no. 227799), and the TOTAL Foundation (Paris; Project “Macroalgal and oomycete benthic diversity in the Canadian Marine Arctic”). This work also received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland) and their support is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. We also would like to thank Laura Grenville-Briggs (KTH, Stockholm) for help with bioinformatics analyses as well as Cindy Grant and Philippe Archambault (University of Quebec, Rimouski) for help with preparing the map of the study area (Fig. 1).Peer reviewedPublisher PD