The gaseous extent of galaxies and the origin of Lyman alpha absorption systems. IV: Lyman alpha absorbers arising in a galaxy group

We present new GHRS observations of Lyman alpha absorption lines associated with a group of galaxies towards the QSO 1545+2101. We have identified eight distinct Lyman alpha absorption features in the spectrum of QSO 1545+2101 at a mean redshift of z=0.2648 with a velocity dispersion of 163 km/s. A group of galaxies is detected in the vicinity of this QSO at a mean redshift of z=0.2645 and velocity dispersion 239 km/s. The identification of discrete absorption systems indicates that they arise in clouds of neutral hydrogen rather than in a diffuse intragroup medium. Our analysis suggests that the Lyman alpha absorption lines are associated with individual galaxies in the group, although a one-to-one relationship between absorbers and galaxies is difficult to establish in such a dense environment.Comment: 16 pages, 3 figures. Accepted for publication in Ap

Clasificación climática de los bosques de Abies pinsapo en el sur de España

Understanding the current distribution of vegetation and its interaction with climate regularity is important for predicting its future change. 35 weather stations with monthly resolutions have been reconstructed using GENPT software to study the pinsapo fir forest climate types. Ten climate variables have been used to describe the particular climate of A. pinsapo forests following the Climatic System of Allué (1990). A climate examination suggests that pinsapo fir forests might be established in a particular climate, which seems to be unique in the Iberian Peninsula, though the species also grows under other climates. A multivariable analysis has been done, providing five classes of pinsapo fir forests sharing some climate features: Atlantic, Mediterranean, warm, continental and cold. Results are biogeographically consistent and may help to explain plant biogeography in this region. Preservation efforts in pinsapo fir forests should be concentrated on the distribution areas with the highest risk of the climate change impact.Los estudios de distribución actual de la vegetación, en un contexto de cambio global, son un elemento importante para predecir los posibles cambios futuros. En este trabajo, a partir de 35 estaciones meteorológicas, se realizó la reconstrucción de los tipos climáticos para el pinsapo, utilizando 10 variables del Sistema Fitoclimatico de Allué (1990). Los resultados sugieren la existencia de un clima específico para la distribución del pinsapo, que parece ser único en la península ibérica, aunque la especie también esta presente en otros fitoclimas. A partir de un análisis multivariable se han identificado cinco clases fitoclimáticas con presencia de pinsapo: atlántico, mediterráneo, templado, continental y frío. Los resultados son biogeográficamente consistentes y pueden ayudar a explicar la biogeografía de su área de distribución. Los programas de conservación del pinsapo deberían utilizar información fitoclimática para definir las zonas prioritarias de protección frente a los posibles efectos del cambio climático

Damped Lyman-alpha Absorption Associated with an Early-Type Galaxy at Redshift z = 0.16377

We report new HST and ground-based observations of a damped Lyman-alpha absorption system toward the QSO 0850+4400. The redshift of the absorption system is z = 0.163770 and the neutral hydrogen column density of the absorption system is log N = 19.81 cm**-2. The absorption system is by far the lowest redshift confirmed damped Lyman-alpha absorption system yet identified, which provides an unprecedented opportunity to examine the nature, impact geometry, and kinematics of the absorbing galaxy in great detail. The observations indicate that the absorption system is remarkable in three respects: First, the absorption system is characterized by weak metal absorption lines and a low metal abundance, possibly less than 4% of the solar metal abundance. This cannot be explained as a consequence of dust, because the neutral hydrogen column density of the absorption system is far too low for obscuration by dust to introduce any significant selection effects. Second, the absorption system is associated with a moderate-luminosity early-type S0 galaxy, although the absorption may actually arise in one of several very faint galaxies detected very close to the QSO line of sight. Third, the absorbing material moves counter to the rotating galaxy disk, which rules out the possibility that the absorption arises in a thin or thick co-rotating gaseous disk. These results run contrary to the expectation that low-redshift damped Lyman-alpha absorption systems generally arise in the gas- and metal-rich inner parts of late-type spiral galaxies. We suggest instead that mounting evidence indicates that low-redshift galaxies of a variety of morphological types may contain significant quantities of low metal abundance gas at large galactocentric distances.Comment: 15 pages, LaTex, 4 figures, to be published in The Astronomical Journa

RIP2 plays a role in cardiac Ca2+ mishandling prompted by chronic kidney disease

post-print81,7 K

A theoretical model for tellurite-sulfates Na2_2Cu5_5(TeO3_3)(SO4_4)3_3(OH)4_4 and K2_2Cu5_5(TeO3_3)(SO4_4)3_3(OH)4_4

A theoretical model for two new tellurite-sulfates, namely Na$_2$Cu$_5$(TeO$_3$)(SO$_4$)$_3$(OH)$_4$ and K$_2$Cu$_5$(TeO$_3$)(SO$_4$)$_3$ (OH)$_4$ is determined to be compatible with ab-initio calculations. The results obtained in this work show that some previous speculations in the literature about the couplings are correct, obtaining a model with a mixture of ferromagnetic and antiferromagnetic couplings. We use a combination of numerical techniques to study the magnetic properties of the model. Our numerical calculations based on the density-matrix renormalization group method reveal that the system presents Ising-like magnetization plateaux at rational values of the saturation magnetization.Comment: 7 pages, 8 figure

Neuronal Metabolism and Neuroprotection: Neuroprotective Effect of Fingolimod on Menadione-Induced Mitochondrial Damage

Imbalance in the oxidative status in neurons, along with mitochondrial damage, are common characteristics in some neurodegenerative diseases. The maintenance in energy production is crucial to face and recover from oxidative damage, and the preservation of different sources of energy production is essential to preserve neuronal function. Fingolimod phosphate is a drug with neuroprotective and antioxidant actions, used in the treatment of multiple sclerosis. This work was performed in a model of oxidative damage on neuronal cell cultures exposed to menadione in the presence or absence of fingolimod phosphate. We studied the mitochondrial function, antioxidant enzymes, protein nitrosylation, and several pathways related with glucose metabolism and glycolytic and pentose phosphate in neuronal cells cultures. Our results showed that menadione produces a decrease in mitochondrial function, an imbalance in antioxidant enzymes, and an increase in nitrosylated proteins with a decrease in glycolysis and glucose-6-phosphate dehydrogenase. All these effects were counteracted when fingolimod phosphate was present in the incubation media. These effects were mediated, at least in part, by the interaction of this drug with its specific S1P receptors. These actions would make this drug a potential tool in the treatment of neurodegenerative processes, either to slow progression or alleviate symptoms

ONGOING RESEARCH ON SPECIES OF DINOPHYSIS: ALTERNATIVES WITH UNCULTURABLE DINOFLAGELLATES

Dinophysis 200