Nitrogen determination in micas of metamorphic rocks

6 pages, 1 table, 1 figure.-- Proceedings of the Seventeenth International Conference on Ion Beam Analysis.-- El pdf del artículo es la versión post-print.-- et al.Micas are minerals that provide large amounts of information regarding geological processes, because of the sensitivity of their chemical composition to temperature, pressure and deformation of rocks in which they form. Rocks under analysis are formed of different minerals with variable grain size. Mica grain size may vary between 5 and 10 μm and approximately correspond to the chemical formula (Si3.2Al0.8)O10(Al1.9Fe0.05Mg0.1)(OH)2(K0.75Na0.05), being distinguishable from other minerals because of their composition and their morphology in secondary electron images and specially backscattered electron (BSE) images. NH4, when present, would partially substitute K in the previous formula. In some cases NH4-rich micas (tobelites) have been described coexisting with the corresponding K-rich micas, but the actual NH4 content of normal K-rich micas is still unknown. Low N content makes necessary to use nuclear reactions such as 14N(d, pγ)15N at 1.4 MeV and its cascade of intense γ-rays. For the quantification and localization of nitrogen on the surface of the samples, PIGE analysis was carried out in the vacuum microprobe line of the CNA, together with simultaneous micro-RBS and micro-PIXE analyses, giving a more comprehensive picture of sample structure and composition.Peer reviewe

Search for a Solution of the Pioneer Anomaly

In 1972 and 1973 the Pioneer 10 and 11 missions were launched. They were the first to explore the outer solar system and achieved stunning breakthroughs in deep-space exploration. But beginning in about 1980 an unmodeled force of \sim 8 \times 10^{-8} cm/s^2, directed approximately towards the Sun, appeared in the tracking data. It later was unambiguously verified as being in the data and not an artifact. The cause remains unknown (although radiant heat remains a likely origin). With time more and more effort has gone into understanding this anomaly (and also possibly related effects). We review the situation and describe ongoing programs to resolve the issue.Comment: 24 pages 8 figure

Modelo experimental de colocación de catéter intratecal lumbar para anestesia espinal en perros

Aunque existe controversia entre Corning y Bier, el primer caso de anestesia espinal se publica en el año 1885, cuando Cornig, accidentalmente, realiza un bloqueo espinal en un perro con cocaína. Desde entonces, la anestesia espinal probablemente ha sido la técnica regional más comúnmente utilizada en la moderna anestesia. Aunque se ha escrito mucho en lo relativo a dicha técnica: aplicaciones, complicaciones..., son pocos los estudios controlados, particularmente en animales donde ha sido posible mantener unas condiciones experimentales estandarizadas. Aún así, han sido descritos métodos experimentales de anestesia espinal 6-11 y epidural12-19 usando la implantación de catéteres en el perro, gato, oveja, rata y humanos. En la gran mayoría de los casos el acceso al espacio subaracnoideo se realiza quirúrgicamente vía occipital (se ha hecho en otras especies como en rata), llegando hasta la cisterna magna, donde puede quedar colocado el catéter, o bien prolongarlo hasta nivel torácico, lumbar. El presente estudio describe un modelo de implantación de catéter intradural en perros, con abordaje lumbar, con técnica quirúrgica previa y con control radioscópico

A common mechanism of defective channel trafficking underlying DFNA2 hearing loss result in different cell surface expression levels of KCNQ4 mutants

KCNQ4 mutations underlie DFNA2, a subtype of autosomal dominant hearing loss. We had previously identified the pore-region p.G296S mutation that impaired channel activity in two manners: it greatly reduced surface expression and abolished channel function. Moreover, G296S mutant exerted a strong dominant-negative effect on potassium currents by reducing the channel expression at the cell surface representing the first study to identify a trafficking-dependent dominant mechanism for the loss of KCNQ4 channel function in DFNA2. Here, we have investigated the pathogenic mechanism associated with all the described KCNQ4 mutations (F182L, W242X, E260K, D262V, L274H, W276S, L281S, G285C, G285S and G321S) that are located in different domains of the channel protein. F182L mutant showed a wild type-like cell-surface distribution in transiently transfected NIH3T3 fibroblasts and the recorded currents in Xenopus oocytes resembled those of the wild-type. The remaining KCNQ4 mutants abolished potassium currents, but displayed distinct levels of defective cell-surface expression in NIH3T3 as quantified by flow citometry. Co-localization studies revealed these mutants were retained in the ER, unless W242X, which showed a clear co-localization with Golgi apparatus. Interestingly, this mutation results in a truncated KCNQ4 protein at the S5 transmembrane domain, before the pore region, that escapes the protein quality control in the ER but does not reach the cell surface at normal levels. Currently we are investigating the trafficking behaviour and electrophysiological properties of several KCNQ4 truncated proteins artificially generated in order to identify specific motifs involved in channel retention/exportation. Altogether, our results indicate that a defect in KCNQ4 trafficking is the common mechanism underlying DFNA

Análisis aerobiológico del polen de Cupressaceae en Granada (sureste P. Ibérica): su repercusión en la población atópica

XV lnternational A.P.L.E. Symposium of Palynolog

A geometric approach to time evolution operators of Lie quantum systems

Lie systems in Quantum Mechanics are studied from a geometric point of view. In particular, we develop methods to obtain time evolution operators of time-dependent Schrodinger equations of Lie type and we show how these methods explain certain ad hoc methods used in previous papers in order to obtain exact solutions. Finally, several instances of time-dependent quadratic Hamiltonian are solved.Comment: Accepted for publication in the International Journal of Theoretical Physic

Mujeres en Bioquímica

We are pleased to present in the magazine "Encounters in Biology" the series of profiles published online in the «Portrait Gallery of Women in Biochemistry» on the SEBBM website, which began in 2011, with the centenary of the Nobel Prize awarded to Marie Curie, International Year of Chemistry. During the celebration of the 22nd IUBMB - 37th FEBS Congress and XXXV Congress of the SEBBM that took place in Seville from September 4 to 9, 2012, a traveling exhibition was inaugurated with this information in panel format.Tenemos el placer de presentar en la revista "Encuentros en la Biología" la serie de perfiles publicados on-li- ne en la «Galería de retratos de Mujeres en Bioquímica» de la web de la SEBBM, que comenzó en 2011, con el centenario del premio Nobel otorgado a Marie Curie, Año Internacional de la Química. Durante la celebra- ción del 22nd IUBMB - 37th FEBS Congress y XXXV Congreso de la SEBBM que tuvo lugar en Sevilla del 4 al 9 de septiembre de 2012 se inauguró una exposición itinerante con esta información en formato de paneles

Estrategias de conservación para Cotoneaster granatensis (Rosaceae), especie catalogada En Peligro de Extinción en la Comunitat Valenciana (España)

Cotoneaster granatensis (Rosaceae) is an endangered species in the Valencian Community with two natural populations known and 37 wild plants located in Alicante province. The strategy applied for conservation of this species comprises three steps in a cyclical method: in situ (first step) - ex situ - in situ (second step). Current conservation status for this species has been evaluated as a part of the first step in situ actions. Ex situ conservation activities consisted of germplasm conservation on seed banks, creation and maintenance of collections of livings plants and production of new plants in order to develop reintroductions (in situ actions: second step) in natural populations. The seed germination is a complex issue, but an effective protocol has been established reaching values over 60% of germination. The plant propagation by cuttings has not been successful. In situ actions such as reducing the threat of herbivory has been also essential to enhance natural populations. The initial results on plantations in the natural habitat show high survival rates of specimens

A contribution to the deterministic modelling of circadian rhythms in cell proliferation activity

This paper presents a deterministic continuous model of proliferative cell activity. The classical series of connected compartments is revisited along with a simple mathematical treatment of two hypotheses: constant transit times and harmonic Ts. Several examples are presented to support these ideas, both taken from previous literature and recent experiences with the fish Carassius auratus, developed at the Junta de Energía Nuclear, Madrid, Spain

Geometrical origin of the *-product in the Fedosov formalism

The construction of the *-product proposed by Fedosov is implemented in terms of the theory of fibre bundles. The geometrical origin of the Weyl algebra and the Weyl bundle is shown. Several properties of the product in the Weyl algebra are proved. Symplectic and abelian connections in the Weyl algebra bundle are introduced. Relations between them and the symplectic connection on a phase space M are established. Elements of differential symplectic geometry are included. Examples of the Fedosov formalism in quantum mechanics are given.Comment: LaTeX, 39 page