138 research outputs found
Lista comentada de la ictiofauna del Canal Beagle.
Inventario de la ictiofauna de la región, evaluación de aspectos de distribución y biología de las especies presentes. Además se incluyó la información completa de todas las entidades tratadas.
Como resultado de este análisis se obtuvo un panorama actualizado del estado del conocimiento de los peces presentes en este sector. (PDF tiene 85 paginas.
Tourism persistence in Spain: National versus international visitors.
In this article, we examine the statistical properties of the time series corresponding to the number
of national and international visitors in Spain using fractional integration. This methodology allows
us to examine the degree of persistence of the series, and thus, infer some conclusions about the
nature of the shocks. According to the results reported in this work, seasonality matters in both
cases, being more important in international tourism. Moreover, we observe significant differences
in the degree of persistence between national and international tourism. Although both series
seem to be mean reverting, with shocks having a transitory nature, higher orders of integration are
observed in the case of the international arrivals.pre-print230 K
Estudio de la biocompatibilidad in vitro de polimeros metacrílicos derivados de pirrolidona-ina
Este estudio analiza la biocompatibilidad de nuevos biomateriales a base de hidrogeles metacrílicos como el poli-[metacrilato de 2-etil-(2-pirrolidona)] (PEPM) y la poli-[metacrilato de 2-etil-(2-pirrolidina)], en comparación con referentes comerciales tales como la poli-(vinil pirrolidona) (PVP) y la poli-(N-N´-dimetilacrilamida) (PDMA). Se utilizaron propiedades bioquímicas, mediante los ensayos de MTT y Alamar Blue, para conocer el efecto de citotoxicidad y proliferación en cultivo de fibroblastos (células VERO), sobre los biomateriales metacrílicos. Adicionalmente, por microscopía óptica y electrónica fueron analizados el grado de adhesión, morfología, muerte celular, proliferación, contracción celular, etc. Además se estudiaron las relaciones entre citotoxicidad y estructura química. En el MTT y en el análisis óptico se obtuvo baja citotoxicidad para PEPM y PVP, media en PEPyM y alta en PDMA. En el Alamar Blue y SEM se produjo una media proliferación-adhesión en PEPM y PEPyM, alta en PVP y muerte celular en PDMA. Sus apropiadas características físico-químicas y su aceptable grado de biocompatibilidad les hacen buenos candidatos en aplicaciones tales como lentes de contacto, sistemas de liberación de fármacos e ingeniería de tejidos.This study analyzed biocompatibility of new biomaterials based on the methacrylic hydrogels derived poly-[2-ethyl-(2-pyrrolidone) methacrylate] (PEPM) and poly-[2-ethyl-(2-pyrrolidine) methacrylate] (PEPyM), in comparison with references such as commercial poly-(vinyl pyrrolidone) (PVP) and poly-(N, N-dimethylacrylamide) (PDMA). The biochemical properties were used to know citotoxicity and proliferation effect over fibroblast culture (VERO cells) in contact with the methacrylic biomaterials, using MTT and Alamar Blue assays. Additionally, were analyzed adhesion grade, morphology, death cell presence, proliferation, cell contraction, etc, by optical and scanning electronic microscopy (SEM). The relationships between their chemical structures and cytotoxicity were studied. In MTT and optical analysis, low cytotoxicity was found for PEPM and PVP, medium in the case of PEPyM, and high for PDMA. In Alamar Blue and SEM, were produced a medium proliferation and adhesion rate for PEPM and PEPyM, high in PVP, and cellular death for PDMA. Their appropriates physico-chemical characteristics and approval biocompatibility grade make them good candidates in applications such as contact lenses, drug release systems and tissue engineering
Estudio de la biocompatibilidad in vitro de formulaciones acrílicas autocurables portadoras de bisfosfonatos de nueva síntesis
En este trabajo se presenta el estudio de la biocompatibilidad in vitro, empleando cultivos celulares de fibroblastos embrionarios humanos, de tres sistemas acrílicos de liberación controlada de bisfosfonatos (BFs). Estos sistemas, basados en metacrilato de metilo (MMA), metacrilato de vitamina E (MVE) y trietilenglicol dimetacrilato (TEGDMA), han sido diseñados para su aplicación en el tratamiento de enfermedades caracterizadas por una elevada resorción osteoclástica. En su preparación se ha empleado un BP comercializado (alendronato; ALN) y dos de nueva síntesis, pertenecientes a la segunda y tercera generaciones, el ácido 1-hidroxi-2-[4-aminofenil]etano-1,1-difosfónico (APBP) y el ácido 1-hidroxi-2-[3-indolil]etano-1,1-difosfónico (IBP), respectivamente. La citotoxicidad de MVE ha sido notablemente inferior a la medida para TEGDMA. La citotoxicidad de APBP e IBP se ha comparado con la de ALN, obteniéndose unos valores para la concentración IC50, de15,56, 9,86 y 6,25 mmol/l para APBP, ALN e IBP, respectivamente. Los niveles de citotoxicidad liberada han sido superiores para la formulación portadora de ALN, situándose a continuación los cementos cargados con IBP y APBP. Cuando los cultivos se han establecido sobre la superficie de las formulaciones, se han detectado unos niveles de proliferación celular y adhesión superiores para los sistemas de liberación de IBP y APBP, siendo además inferior en estos casos la mortalidad celular.This paper reports the in vitro biocompatibility study, using human embryonic fibroblast cultures, of three acrylic systems for controlled release of bisphosphonates (BFs). These systems, that are based on methyl methacrylate (MMA), vitamin E methacrylate (MVE) and triethyleneglycol dimethacrylate (TEGDMA), have been designed for its application in the treatment of pathologies characterized by a high osteoclastic resorption. A commercial BP (alendronate; ALN) and two novel BPs, belonging to the second and third generations, 1-hydroxy-2-[4-aminophenyl]ethane-1,1-diphosphonic acid (APBP) and 1-hydroxy-2-[3-indolyl]ethane-1,1-diphosphonic acid (IBP), respectively, have been used in their preparation. The cytotoxicity of MVE has been notably lower than that measured for TEGDMA. Cytotoxicity of APBP and IBP was evaluated along with that of ALN, and the following values of the IC50, concentration were obtained for APBP, ALN and IBP respectively: 15.56, 9.86 and 6.25 mmol/l. The cytotoxicity levels obtained from the extracts of the cured systems were higher for the formulation containing ALN, followed by the cements loaded with IBP and APBP. When the cultures were seeded directly on the formulations surface, higher levels of cellular proliferation and adhesion were obtained for the systems containing IBP and APBP, the cellular mortality being also inferior in these cases
Lista comentada de la ictiofauna del Canal Beagle, Tierra del Fuego, Argentina. Iconografía.
A ciento veintidós años de las primeras menciones realizadas por Perugia en 1891 sobre peces del Canal Beagle, editamos la presente iconografía que incluye alrededor de treinta especies de las mencionadas por López et al., en 1996. Este trabajo, desarrollado en el CADIC dentro del proyecto
Biología de los recursos ictícos del Canal de Beagle financiado por el CONICET, junto al publicado por Lloris y Rucabado (1991), proveyeron elementos de base para tener una visión más profunda del componente ictiofaunistíco de la región.
En la presente publicación se destaca la magnífica obra del maestro Miguel Barbagallo, quién vuelca su capacidad y espíritu en estas láminas, las que además de su valor artístico son un aporte más a la consolidación del conocimiento de los recursos naturales de nuestro país
Born too early and too small: higher order cognitive function and brain at risk at ages 8–16
Prematurity presents a risk for higher order cognitive functions. Some of these deficits
manifest later in development, when these functions are expected to mature. However,
the causes and consequences of prematurity are still unclear. We conducted a
longitudinal study to first identify clinical predictors of ultrasound brain abnormalities in
196 children born very preterm (VP; gestational age 32 weeks) and with very low birth
weight (VLBW; birth weight 1500 g). At ages 8–16, the subset of VP-VLBW children
without neurological findings (124) were invited for a neuropsychological assessment
and an MRI scan (41 accepted). Of these, 29 met a rigorous criterion for MRI quality
and an age, and gender-matched control group (n = 14) was included in this study.
The key findings in the VP-VLBW neonates were: (a) 37% of the VP-VLBW neonates
had ultrasound brain abnormalities; (b) gestational age and birth weight collectively with
hospital course (i.e., days in hospital, neonatal intensive care, mechanical ventilation and
with oxygen therapy, surgeries, and retinopathy of prematurity) predicted ultrasound
brain abnormalities. At ages 8–16, VP-VLBW children showed: a) lower intelligent
quotient (IQ) and executive function; b) decreased gray and white matter (WM) integrity;
(c) IQ correlated negatively with cortical thickness in higher order processing cortical
areas. In conclusion, our data indicate that facets of executive function and IQ are the
most affected in VP-VLBW children likely due to altered higher order cortical areas and
underlying WMThis study was supported by the Spanish Government Institute Carlos III (FIS Pl11/02860), Spanish Ministry of Health to MM-L, and the University of Castilla-La Mancha mobility Grant VA1381500149
Spatiotemporal-dressed optical solitons in hollow-core capillaries
[EN]The nonlinear propagation of a laser beam in a hollow-core capillary is studied by solving the spatiotemporal nonlinear propagation equation. Although we assume to initially couple the light into only one high spatial mode of the capillary, we have identified that the beam can propagate as a new type of multi-mode solitonic structure, the spatiotemporal-dressed soliton, which consists of a mixture of spatial modes in which one has most of the energy while the rest of them, with small contributions, module (dress) the propagation of the main spatial mode. As a consequence of such behavior, we observe a clean self-compression process, obtaining a pulse in the single-cycle limit, accompanied by a giant blue dispersive wave and a new type of multi-mode dispersive wave that appears in the mid-IR region
Theoretical analysis of single-cycle self-compression of near infrared pulses using high-spatial modes in capillary fibers
[EN]Soliton self-compression is demonstrated during the propagation of high spatial modes in hollow core fibers in the near-infrared spectral region, taking advantage of their negative dispersion response. We have found that there is always an optimum spatial mode to observe this phenomenon, compressing the pulses down to the single-cycle regime without needing any external compression device and with a consequent increase in the output peak power. Our result is relevant for any ultrashort laser application in which few- or single-cycle pulses are crucial
Morpho-sedimentary dynamics of a micro-tidal mixed sand and gravel beach, Playa Granada, southern Spain
publisher: Elsevier articletitle: Morpho-sedimentary dynamics of a micro-tidal mixed sand and gravel beach, Playa Granada, southern Spain journaltitle: Marine Geology articlelink: http://dx.doi.org/10.1016/j.margeo.2016.05.003 content_type: article copyright: © 2016 Elsevier B.V. All rights reserved
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