Chromospheric polarimetry through multi-line observations of the 850 nm spectral region

Future solar missions and ground-based telescopes aim to understand the magnetism of the solar chromosphere. We performed a supporting study in Quintero Noda et al. (2016) focused on the infrared Ca II 8542 A line and we concluded that is one of the best candidates because it is sensitive to a large range of atmospheric heights, from the photosphere to the middle chromosphere. However, we believe that it is worth to try improving the results produced by this line observing additional spectral lines. In that regard, we examined the neighbour solar spectrum looking for spectral lines that could increase the sensitivity to the atmospheric parameters. Interestingly, we discovered several photospheric lines that greatly improve the photospheric sensitivity to the magnetic field vector. Moreover, they are located close to a second chromospheric line that also belongs to the Ca II infrared triplet, i.e. the Ca II 8498 A line, and enhances the sensitivity to the atmospheric parameters at chromospheric layers. We conclude that the lines in the vicinity of the Ca II 8542 A line not only increase its sensitivity to the atmospheric parameters at all layers, but also they constitute an excellent spectral window for chromospheric polarimetry.Comment: 11 pages, 8 figures, 1 tabl

Red Carbon Thin Film: A Carbon-Oxygen Semiconductor with Tunable Properties by Amine Vapors and Its Carbonization toward Carbon Thin Films

The requirements for organic semiconductor materials and new methods for their synthesis at low temperature have risen over the last decades, especially due to concerns of sustainability. Herein, the synthesis of a carbon/oxygen molecular semiconductor thin film, which is promptly reactive toward amines, is presented. This allows for tuning the semiconductor properties and application as amine vapor sensors for a scope of analogous amines. The gas-to-solid phase reaction causes a significant change of the films’ optical properties, blue-shifting the absorption and the photoluminescence spectra from the red to the near UV spectral range. The irreversible chemical reaction between the thin film and the amine vapor is also exploited for the preparation of nitrogen-containing thin carbon films. The herein presented materials and methods will be of interest for gas sensing applications as well as for the development of tunable semiconductors and heteroatom-doped thin films

The effects of crosslinking on the rheology and cellular behavior of polymer-based 3D-multilayered scaffolds for restoring articular cartilage

Polymer-based tri-layered (bone, intermediate and top layers) scaffolds used for the restoration of articular cartilage were prepared and characterized in this study to emulate the concentration gradient of cartilage. The scaffolds were physically or chemically crosslinked. In order to obtain adequate scaffolds for the intended application, the impact of the type of calcium phosphate used in the bone layer, the polymer used in the intermediate layer and the interlayer crosslinking process were analyzed. The correlation among SEM micrographs, physical-chemical characterization, swelling behavior, rheological measurements and cell studies were examined. Storage moduli at 1 Hz were 0.3-1.7 kPa for physically crosslinked scaffolds, and 4-5 kPa (EDC/NHS system) and 15-20 kPa (glutaraldehyde) for chemically crosslinked scaffolds. Intrinsic viscoelasticity and poroelasticity were considered in discussing the physical mechanism dominating in different time/frequency scales. Cell evaluation showed that all samples are available as alternatives to repair and/or substitute cartilage in articular osteoarthritis

An introduction to Graph Data Management

A graph database is a database where the data structures for the schema and/or instances are modeled as a (labeled)(directed) graph or generalizations of it, and where querying is expressed by graph-oriented operations and type constructors. In this article we present the basic notions of graph databases, give an historical overview of its main development, and study the main current systems that implement them

NOTAS SOBRE ANIDACIÓN Y CUIDADO MATERNAL DEL COLIBRÍ ESMERALDA HONDUREÑO (AMAZILIA LUCIAE) EN EL VALLE DE AGALTA, HONDURAS

Resumen ∙ El Colibrí Esmeralda Hondureño (Amazilia luciae) es la única ave endémica de Honduras. Esta especie en peligro habita valles intermontanos con bosques áridos espinosos, bosque semi‐deciduo o áreas abiertas con arbustos dispersos. Durante un año (agosto de 2014–julio de 2015) se llevaron a cabo búsquedas de nidos de Amazilia luciae. Se registraron 17 nidos los cuales fueron monitoreados. La mayoría de los nidos (N = 15) se encontraron entre enero y marzo. Los nidos tuvieron forma de copa y se registró el uso de nueve especies de plantas nativas como sustrato. El ciclo reproductivo, desde construcción hasta que los polluelos dejan el nido, fue de 42 días. Los nidos encontrados contenían 1–2 huevos o polluelos. Finalmente se documentaron 14 ocasiones de cuidado maternal hacia juveniles fuera del nido. Estos resultados ayudarán a guiar estudios futuros, así como informar a participantes de esfuerzos locales de conservación dirigidos a beneficiar esta especie.Abstract ∙ Notes on the nesting and maternal care of the Honduran Emerald (Amazilia luciae) in the Agalta Valley, Honduras The Honduran Emerald (Amazilia luciae) is the only endemic bird in Honduras. This endangered hummingbird inhabits intermontane valleys with arid thorn forests, semi‐deciduous forest or open habitat with dispersed shrubs. During one year (August 2014–July 2015) we conducted searches for Honduran Emerald nests. We found and monitored 17 nests. Most nests (N = 15) were found between January and March. Nests were cup‐shaped and nine native plant species were recorded as substrate. The nesting cycle, from nest construction to fledging, takes approximately 42 days. Nests contained 1–2 eggs or nestlings. We documented 14 occasions of maternal care towards juveniles outside of the nest. This study will help guide future studies as well as promote local conservation efforts