Conocer e identificar para respetar y conservar: gymkana foliar

Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasFALSEsubmitte

The effect of titanium dioxide nanoparticles obtained by microwave-assisted hydrothermal method on the color and decay resistance of pinewood

This study aimed to synthesize titanium dioxide nanoparticles by microwave-assisted hydrothermal method to incorporate them to the structure of Pinus elliottii wood. The color changes and the decay resistance of impregnated wood was investigated. The titanium dioxide nanoparticles were impregnatedinto Pinus elliottii wood by vacuum-pressure and simple immersion methods. Furthermore, Pinus elliottii wood was treated with chromated copper borate solution tocompare their effectiveness to the titanium dioxide treated wood. The titanium dioxide nanoparticles impregnated by vacuum-pressurewere presented especially on the wood surface, forming a homogeneous coating. The titanium dioxide nanoparticles did not change the natural color of wood and, at the same time, decreased the degree of the white rot fungus (Ganoderma applanatum) colonization in the wood structure and the wood decay,compared to the untreated one. The titanium dioxide treated wood samples provided similar protection against decay in comparison to wood treated with chromated copper borate. The impegnation with titanium dioxide nanoparticles can be a good alternative to decrease/avoid the fungi proliferation,providing to Pinus elliottii wood a self-cleaning mechanism

Árboles al desnudo: Reconocimiento e identificación de especies caducifolias del Real Jardín Botánico Alfonso XIII en invierno

Depto. de Biodiversidad, Ecología y EvoluciónFac. de Ciencias BiológicasFALSEsubmitte

Extreme magnification of an individual star at redshift 1.5 by a galaxy-cluster lens

International audienceGalaxy-cluster gravitational lenses can magnify background galaxies by a total factor of up to ~50. Here we report an image of an individual star at redshift z = 1.49 (dubbed MACS J1149 Lensed Star 1) magnified by more than ×2,000. A separate image, detected briefly 0.26″ from Lensed Star 1, is probably a counterimage of the first star demagnified for multiple years by an object of ≳3 solar masses in the cluster. For reasonable assumptions about the lensing system, microlensing fluctuations in the stars’ light curves can yield evidence about the mass function of intracluster stars and compact objects, including binary fractions and specific stellar evolution and supernova models. Dark-matter subhaloes or massive compact objects may help to account for the two images’ long-term brightness ratio

HerMES: SPIRE detection of high-redshift massive compact galaxies in GOODS-N field

We have analysed the rest-frame far-infrared properties of a sample of massive (M_star > 10^11 M_sun) galaxies at 2 ≲z≲ 3 in the Great Observatories Origins Deep Survey-North (GOODS-N) field using the Spectral and Photometric Imaging Receiver (SPIRE) instrument aboard the Herschel Space Observatory. To conduct this analysis we take advantage of the data from the Herschel Multi-tiered Extragalactic Survey (HerMES) key programme. The sample comprises 45 massive galaxies with structural parameters characterized with HST NICMOS-3. We study detections at submm Herschel bands, together with Spitzer 24-μm data, as a function of the morphological type, mass and size. We find that 26/45 sources are detected at MIPS 24 μm and 15/45 (all MIPS 24-μm detections) are detected at SPIRE 250 μm, with disc-like galaxies more easily detected. We derive star formation rates (SFRs) and specific star formation rates (sSFRs) by fitting the spectral energy distribution of our sources, taking into account non-detections for SPIRE and systematic effects for MIPS derived quantities. We find that the mean SFR for the spheroidal galaxies (∼50–100 M_sun yr^[−1]) is substantially (a factor ∼3) lower than the mean value presented by disc-like galaxies (∼250–300 M_sun yr^[−1])

Genetic associations of leptin-related polymorphisms with systemic lupus erythematosus

Leptin is abnormally elevated in the plasma of patients with systemic lupus erythematosus (SLE), where it is thought to promote and/or sustain pro-inflammatory responses. Whether this association could reflect an increased genetic susceptibility to develop SLE is not known, and studies of genetic associations with leptin-related polymorphisms in SLE patients have been so far inconclusive. Here we genotyped DNA samples from 15,706 SLE patients and healthy matched controls from four different ancestral groups, to correlate polymorphisms of genes of the leptin pathway to risk for SLE. It was found that although several SNPs showed weak associations, those associations did not remain significant after correction for multiple testing. These data do not support associations between defined leptin-related polymorphisms and increased susceptibility to develop SLE