Igneous differentiation in porphyry dikes

[Resumen] Se aborda de manera teórica los principales procesos operativos de diferenciación ígnea en secciones transversales de los conductos filonianos, aplicándolo a los diques de pórfido granítico s. 1. del Sistema Central Español. Para estos magmas se deduce un régimen de flujo marcadamente laminar en el conducto (:~ 30 mts. potencia). Estos caracteres impiden tanto la efectividad de franccionamiento cristalino «in situ:\), como grados importantes de asimilación o contaminación en ruta hacia la superficie. Los diques simples, de flujos isoviscosos, van a diferenciarse por fenómenos, principalmente, de flujo ígneo, en ocasiones combinado con la presencia de varios magmas fluyendo a la vez en el mismo pulso (conductos gruesos o flujos veloces). Con estos mecanismos se tenderá a generar evoluciones del tipo félsico a máfico, de borde a centro del dique de pórfido. Los diques compuestos se formarán cuando los magmas son suficientemente contrastados en sus caracteres físicos (viscosidad, p. ej.) y químicos, o cuando son varíos pulsos magmáticos a través del mismo conducto. En estos casos podría haber fen6menos de mezcla magmática si la diferencia de viscosidad es alta y uno de esos magmas es poco viscoso (magmas básicos). En estos casos podrían generarse zonas básicas en el borde, o no, de los diques. de pórfido. En resumen la diferenciación de flujo, la mezcla magmática y la asociación de varios líquidos fluyendo en el mismo conducto (de manera simultánea o por pulsos magmáticos algo separados en el tiempo), parecen ser los mecanismos de diferenciación ígnea más efectivos de estos magmas graníticos que fluyen en angostos conductos filonianos[Abstract] We deal in theoretical way wíth the main differentiation proccesses taking place in dike conducts, applied to the porphyry dikes of the Spanish Central System. For these magmas we infer a strong laminar flow regime (~30 m dike witdh). This, prevent an efficient «in situ:\) cristal fractionation as well as large extent of assimilation-contamination processes during the ascent of the magmas «en route» to more surface levels. Simple dikes, with isoviscous flow, could differentiate mainley by igneous flow. Sometimes this mechanism is combinated with the possibility of severa! Magmas flowing togheter on the same pulse (thick dikes or fast flows). With these mechanisms felsic to mafic evolutions are favoured inward the porphyry dike. Composite dikes are formed when magmas are contrasted enough in their chemical or physical features (p. ej. viscosity), or when different magmatic pulses occur in the same channel. In these conditions commingling of magmas could exist if the viscosity ratio is high apd one of the magmas is very fluid (basic one). These processes could generate basic margins in the porphyry dikes. In short, flow differentiation, magmatic mixing and flowing of associated magmas (simultaneously or by successive pulses), seem to be the more efficient differentiation mechanisms for granitic magmas flowing in narrow dikes

Relaciones entre ortogneises y series volcano-sedimentarias en el macizo de El Caloco (Guadarrama Central)

El macizo de El Caloco está constituido por dos formaciones metamórficas de caracteres distintos. Una es fundamentalmente paradcrivada (metapelitas con niveles carbonatados asociados>, con tramos de origen voleano-sedimentarios o subvolcánico (gneises glandulares fémicos) y que se ha denominado «serie fémica heterogénea». Aparecen también metabasitas con clinopiroxeno, granate y plagioclasa, en parte anfibolitizadas. La otra formación es de naturaleza cuarzo-feldespática y está compuesta por ortogneises glandulares y leucogneises de origen mctagranítico. En función de los caracteres petrológicos y geoquimicos interpretamos los ortogneises cuarzo-feldespáticos como representantes de antiguos granitos de dos micas con silicatos de aluminio (granitos tipo 8). El estudio geoquimico pone de manifiesto en las facies más diferenciadas (leucogneises con nidos de turmalina y/o granate> un trend evolutivo de carácter sílico-potásico. Existe un contacto neto y discordante entre ambos conjuntos, encontrándose localmente facies mosqueadas en los esquistos metapelíticos próximos al mismo.Peer reviewe

Geochemistry and geochronology of mafic rocks from the Spanish Central System: Constraints on the mantle evolution beneath central Spain

The Spanish Central System (SCS) contains several suites of Palaeozoic mafic igneous intrusions with contrasting geochemical affinity: Ordovician tholeiitic metabasites, Variscan calc-alkaline gabbros (Gb1) and microdiorites (Gb2), shoshonitic monzogabbros (Gb3) and alkaline diabases and lamprophyres (Gb4). Not all of these rocks are accurately dated, and several aspects of their genesis are still poorly understood. We present new whole-rock geochemical data (major and trace elements, and Sr–Nd isotopes), U–Pb and Lu–Hf isotopic ratios on magmatic zircons and 40Ar/39Ar amphibole geochronology results in order to establish a precise chronology for the successive events of magmatism in the SCS, and discuss the nature of their mantle sources. Accurate ages have been determined for the Variscan gabbros (305–294 ​Ma), the microdiorites (299 ​Ma) and the accompanying felsic porphyries (292 ​Ma), the shoshonitic monzogabbros (285 ​Ma), and the alkaline diabases (274 ​Ma) and monzosyenites (271–264 ​Ma). According to this information, the Variscan mafic magmatism would be mainly concentrated in the range of 305–294 ​Ma, with a final manifestation represented by the minor shoshonitic dykes. The alkaline magmatism proved to be slightly older than previously thought and yielded at least two distinct pulses: diabases and lamprophyres–monzosyenites. Zircon Hf isotopes evidence the involvement of depleted and slightly enriched mantle sources. The bulk of the εHf values are in the broad range of −8 to +11, indicative of melting both depleted and enriched mantle regions. The high within-sample Hf isotope variation (up to ~11 epsilon units) shown by samples from the Variscan series (gabbros, microdiorites and monzogabbros) could be explained mainly by hybridisation of magmas derived from heterogeneous lithospheric mantle sources. Pressure estimates indicate that the Variscan mafic magmas were extracted from the lithosphere. The Nd–Hf isotopic composition of these suites of rocks suggests the recycling of pelitic sediments during the Cadomian orogeny. Deeper (asthenospheric) mantle levels were involved in the generation of the alkaline suite, whose anomalous negative εHf values (moderately decoupled with respect to radiogenic Nd) could be associated with subducted oceanic components raised by mantle upwelling associated with lithosphere thinning and extension during the Permian

Dynamic Companion Harmonic Circuit Models for Analysis of Power Systems with Embedded Power Electronics Devices

In this paper a methodology that extends the dynamic harmonic domain (DHD) analysis of large networks is presented. The method combines DHD analysis and discrete companion circuit modeling resulting in a powerful analytic technique called dynamic companion harmonic circuit modeling. It provides for a complete dynamic harmonic analysis of the system while preserving the advantages of discrete companion circuit models. The methodology is illustrated by its application to a three-node power system, where reactive power compensation is achieved using a fixed-capacitor, thyristor-controlled reactor (FC-TCR) and its control system

Nuts and bolts of ITRAQ-based quantitative analysis

Comunicaciones a congreso

Measurements of Extended Magnetic Fields in Laser-Solid Interaction

Magnetic fields generated from a laser-foil interaction are measured with high fidelity using a proton radiography scheme with in situ x-ray fiducials. In contrast to prior findings under similar experimental conditions, this technique reveals the self-generated, Biermann-battery fields extend beyond the edge of the expanding plasma plume to a radius of over 3.5 mm by t=+1.4 ns, a result not captured in state-of-the-art magneto-hydrodynamics simulations. An analysis of two mono-energetic proton populations confirms that proton deflection is dominated by magnetic fields far from the interaction (>2 mm) and electric fields are insignificant. Comparisons to prior work suggest a new physics mechanism for the magnetic field generation and transport in laser-solid interactions.Comment: 9 pages, 8 figure

A strategic reflection for the management and implementation of CAR-T therapy in Spain: an expert consensus paper

CAR-T cell therapy represents a therapeutic revolution in the prognosis and treatment of patients with certain types of hematological cancer. However, they also pose new challenges in the healthcare, regulatory and financial fields. The aim of the RET-A project was to undertake a strategic reflection on the management of CAR-T therapies within the Spanish National Health System, to agree on recommendations that will help to better deal with the new context introduced by these cell therapies in the present and in the future. This think tank involved 40 key agents and opinion leaders. The experts identified three great challenges for implementing advanced therapies in Spain: therapeutic individualisation, with a multidisciplinary approach; acceleration of access times, by minimizing bureaucracy; and increase in the number of centers qualified to manage the CAR-T therapies in the NHS. The experts agreed on the ideal criteria for designating those qualified centers. They also agreed on a comprehensive CAR-T care pathway with the timings and roles which would ideally be involved in each part of the process.This study was funded by Gilead Sciences, Inc.Peer reviewe

Neuroprotective Natural Molecules, From Food to Brain

The prevalence of neurodegenerative disorders is increasing; however, an effective neuroprotective treatment is still remaining. Nutrition plays an important role in neuroprotection as recently shown by epidemiological and biochemical studies which identified food components as promising therapeutic agents. Neuroprotection includes mechanisms such as activation of specific receptors, changes in enzymatic neuronal activity, and synthesis and secretion of different bioactive molecules. All these mechanisms are focused on preventing neuronal damage and alleviating the consequences of massive cell loss. Some neuropathological disorders selectively affect to particular neuronal populations, thus is important to know their neurochemical and anatomical properties in order to design effective therapies. Although the design of such treatments would be specific to neuronal groups sensible to damage, the effect would have an impact in the whole nervous system. The difficult overcoming of the blood brain barrier has hampered the development of efficient therapies for prevention or protection. This structure is a physical, enzymatic, and influx barrier that efficiently protects the brain from exogenous molecules. Therefore, the development of new strategies, like nanocarriers, that help to promote the access of neuroprotective molecules to the brain, is needed for providing more effective therapies for the disorders of the central nervous system (CNS). In order both to trace the success of these nanoplatforms on the release of the bioactive cargo in the CNS and determinate the concentration at trace levels of targets biomolecules by analytical chemistry and concretely separation instrumental techniques, constitute an essential tool. Currently, these techniques are used for the determination and identification of natural neuroprotective molecules in complex matrixes at different concentration levels. Separation techniques such as chromatography and capillary electrophoresis (CE), using optical and/or mass spectrometry (MS) detectors, provide multiples combinations for the quantitative and qualitative analysis at basal levels or higher concentrations of bioactive analytes in biological samples. Bearing this in mind, the development of food neuroprotective molecules as brain therapeutic agents is a complex task that requires the intimate collaboration and engagement of different disciplines for a successful outcome. In this sense, this work reviews the new advances achieved in the area toward a better understanding of the current state of the art and highlights promising approaches for brain neuroprotection