Distribución biogeográfica de las especies de hidrozoos tecados bentónicos recogidas durante la campaña “Antártida 8611”

The biogeographical distribution of the benthic hydroid species collected during the Spanish Antarctic expedition Antártida 8611 has been studied. An inventory of the Antarctic and Magellan benthic thecate hydroid faunas, along with a comparison between the two, have been also carried out. 104 and 126 species of thecate hydroids have been considered in the Antarctic and Magellan areas, respectively. 72 species (69%) of the Antarctic species and 49 (39%) of the Magellan species are endemic. 23 species are present both in the Antarctic Region and in the Magellan area, representing 22% and 18% respectively, and indicating an important relationship between both faunas.Se ha estudiado la distribución biogeográfica de las especies de hidrozoos bentónicos recogidos durante la campaña de prospección científico-pesquera “Antártida 8611”. Asimismo, se ha realizado un inventario de la fauna de hidrozoos tecados bentónicos antárticos y magallánicos, habiéndose llevado a cabo una comparación entre ambas faunas. 104 y 126 especies de hidrozoos tecados se han considerado en las áreas antártica y magallánica respectivamente. 72 especies (69%) de las especies antárticas y 49 (39%) de las magallánicas son endémicas. 23 especies están presentes en ambas regiones, representando un 22% y un 18% respectivamente e indicando una importante relación entre ambas faunas

Biological applications of ferroelectric materials

The study and applications of ferroelectric materials in the biomedical and biotechnological fields is a novel and very promising scientific area that spans roughly one decade. However, some groups have already provided experimental proof of very interesting biological modulation when living systems are exposed to different ferroelectrics and excitation mechanisms. These materials should offer several advantages in the field of bioelectricity, such as no need of an external electric power source or circuits, scalable size of the electroactive regions, flexible and reconfigurable “virtual electrodes,” or fully proved biocompatibility. In this focused review, we provide the underlying physics of ferroelectric activity and a recount of the research reports already published, along with some tentative biophysical mechanisms that can explain the observed results. More specifically, we focus on the biological actions of domain ferroelectrics and ferroelectrics excited by the bulk photovoltaic effect or the pyroelectric effect. It is our goal to provide a comprehensive account of the published material so far and to set the stage for a vigorous expansion of the field, with envisioned applications that span from cell biology and signaling to cell and tissue regeneration, antitumoral action, or cell bioengineering to name a fe

Listado taxonómico comentado de los Capitélidos (Annelida, Polychaeta) de la península Iberica, islas Chafarinas, Baleares y Canarias

The present annotated checklist has been elaborated after revision of preserved materials (from the Museo Nacional de Ciencias Naturales, Madrid and the reference collection of the Marine Biology Laboratory of the University of Valencia) and published literature related to capitellids from the Iberian Peninsula, Chafarinas, Balearic and Canary Islands. Twenty-four species and subspecies belonging to thirteen genera are recognized as valid taxa. With this checklist we include some taxonomic details and information on distribution at both global and regional levels. This work includes the setal formula and diagrammatic representation of capitellid taxa treated in this study.Se ha elaborado un listado taxonómico comentado de los capitélidos de la Península Ibérica, Islas Chafarinas, Baleares y Canarias a partir de la revisión de materiales (Museo Nacional de Ciencias Naturales, Madrid y colección de referencia del Laboratorio de Biología Marina de la Universidad de Valencia) y de la bibliografía publicada referente a este grupo. Se reconocen como taxones válidos 24 especies y subespecies pertenecientes a 13 géneros. En esta lista se incluyen para cada especie algunos detalles taxonómicos e información sobre su distribución geográfica tanto a nivel mundial como regional. Asimismo, se aporta la fórmula setal y el diagrama gráfico para los taxones contemplados en este estudio

Trapping and patterning of biological objects using photovoltaic tweezers

Photovoltaic tweezers are a recently proposed technique for manipulation and patterning of micro- and nano-objects. It is based in the dielectrophoretic forces associated to the electric fields induced by illumination of certain ferroelectrics due to the bulk photovoltaic effect. The technique has been applied to the patterning of dielectric and metal micro- and nano-particles. In this work, we report the use of photovoltaic tweezers to pattern biological objects on LiNbO3:Fe. Specifically, spores and pollen grains and their nanometric fragments have been trapped and patterned. 1D and 2D arrangements have been achieved by deposition in air or from a hexane suspension. The quality of patterns obtained with nanometric fragments is even better than previous results using photovoltaic tweezers with inorganic micro- and nano-particles. In fact, 1D patterns with a period of 2 μm, almost half of the minimum reported period achieved with photovoltaic tweezers, have been obtained with pollen fragmentsThis work was supported by Spanish projects MAT2011-28379-C03 and MAT2014-57704-C0

Diffractive optical devices produced by light-assisted trapping of nanoparticles

© 2015 Optical Society of America.]. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibitedOne and two-dimensional diffractive optical devices have been fabricated by light assisted trapping and patterning of nanoparticles. The method is based on the dielectrophoretic forces appearing in the vicinity of a photovoltaic crystal, such as Fe:LiNbO3, during or after illumination. By illumination with the appropriate light distribution, the nanoparticles are organized along patterns designed at will. One- and two-dimensional diffractive components have been achieved on X- and Z-cut Fe:LiNbO3 crystals, with their polar axes parallel and perpendicular to the crystal surface, respectively. Diffraction gratings with periods down to around a few micrometers have been produced using metal (Al, Ag) nanoparticles with radii in the range of 70-100 nm. Moreover, several 2D devices, such as Fresnel zone plates, have been also produced showing the potential of the method. The diffractive particle patterns remain stable when light is removed. A method to transfer the diffractive patterns to other non-photovoltaic substrates, such as silica glass, has been also reportedThis work was supported by Spanish projects MAT2011- 28379-C03 and MAT2014-57704-C0

Satélite de altar resolución espacial en la determinación de la fracción de cabida cubierta en sistemas adehesados

La dehesa es un ecosistema de creación humana a partir del bosque de encinas primitivas en el que se han aclarando los árboles y controlado el estrato arbustivo para que se estabilice el pastizal. Su densidad arbórea es muy variable y depende del tratamiento recibido a lo largo de los años. La obtención de la densidad de cobertura arbórea de dicho sistema se calcula mediante la Fracción de Cabida Cubierta (FCC), medida que relaciona la superficie cubierta por la copa del árbol respecto del resto de superficie. En comparación a las imágenes utilizadas actualmente para la obtención de la FCC como ortofotografías o vuelos fotogramétricos, las imágenes satélite de alta resolución espacial ofrecen suficiente detalle espacial para poder aislar la copa de los árboles del entorno, unido a la multiespectralidad de los datos que permite su correcta caracterización espectral. El objetivo de este trabajo fue desarrollar una metodología con imágenes pan-sharpened QuickBird que, a partir del análisis espectral de los árboles, generó imágenes en formato binario árbol-no árbol mediante técnicas de combinación de bandas para la obtención de la FCC. Los resultados obtenidos fueron satisfactorios al obtener fiabilidades mayores del 90% en la determinación de las copas de los árboles en la mayoría de los análisis realizados.The dehesa is an ecosystem developed from primitive oak forest where trees have been clarified and the shrub layer controlled to stabilize the pasture. The tree density is very variable and depends on the treatment received over the years. This density can be calculated by the Canopy Cover Fraction (CCF), a measure that relates the area covered by the trees over the other surface. Satellite imagery of high spatial resolution provide enough spatial detail to isolate the treetops from the environment, and enough multispectral data to allow the correct spectral characterization. The aim of this study was to develop a methodology with QuickBird pan-sharpened imagery for obtaining the CCF based on a spectral analysis of trees and a binary reclassification (tree- no tree) of each band. The results were satisfactory with accuracies greater than 90% in the discrimination of trees in most of the analysis

Particle Patterning on Lithium Niobate waveguides via photovoltaic tweezers

Successful micro and nano-particle patterning on iron doped lithium niobate waveguides using photovoltaic fields is reported. This technique previously used in bulk crystals is here applied to waveguide configuration. Well defined particle patterns are obtained using two types of planar waveguides (by proton exchanged and swift heavy ion irradiation) and metallic and dielectric neutral particles. The use of waveguide configuration has allowed a reduction of the light exposure time until 3 s, two orders of magnitude smaller than typical values used in bulk

Synergy between pyroelectric and photovoltaic effects for optoelectronic nanoparticle manipulation

© 2019 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved.The combined action of the pyroelectric (PY) and photovoltaic (PV) effects, exhibited by z-cut LiNbO3:Fe substrates, has been investigated for particle trapping and patterning applications. The novel hybrid procedure provides new possibilities and versatility to optoelectronic manipulation on LiNbO3 substrates. It has allowed obtaining periodic and arbitrary 2D patterns whose particle density distribution is correlated with the light intensity profile but can be tuned through ΔT according to the relative strength of the PV and PY effects. A relevant result is that the PY and PV contributions compete for a ΔT range of 1-20 °C, very accessible for experiments. Moreover, the synergy of the PY and PV has provided two additional remarkable applications: i) A method to measure the PV field, key magnitude for photovoltaic optoelectronic tweezers. Using this method, the minimum field needed to obtain a particle pattern has been determined, resulting relatively high, E~60 kV/cm, and so, requiring highly doped crystals when only using the PV effect. ii) An strategy combining the PY and PV to get particle patterning in samples inactive for PV trapping when the PV field value is under that thresholdMinisterio de Ciencia, Innovación y Universidades of Spain (MAT2014-57704-C3, MAT2017-83951-R); Universidad Politécnica de Madrid (RR01/2016