1,275 research outputs found
The Early Permian of Valdeviar in Sevilla province, SW Spain: basin history and climatic/palaeogeographic implications
Se describe el relleno de una cuenca continental del Pérmico Inferior, que muestra una expansión gradual hacia el SE y que comienza en su extremo NW con depósitos correspondientes a una paleotopografía fuerte. En esta cuenca se acumularon, además, capas rojas, depósitos volcanoclásticos ácidos, y coladas de basalto con una representación menor de lavas más ácidas. Un centro volcánico fue detectado a unos 3 a 5 km al NE de la cuenca de Valdeviar. Conglomerados fluviales con un fuerte elemento brechoide sugieren el cauce de un río caudaloso con aportes laterales de coluvión de un paleorelieve importante. Siguen areniscas conglomeráticas de tipo braided. Estos depósitos caracterizan al relleno inicial de la cuenca, pero las condiciones sedimentarias se cambiaron predominantemente a lacustres más adelante, con lutitas y limonitas que muestran icnofósiles, restos vegetales flotados, y agrupaciones locales de árboles pequeños. Se secaron las áreas lacustres periódicamente, dando lugar a un régimen oxidante con formación de suelos. Las capas rojas superiores, lutíticas, contienen areniscas y conglomerados lenticulares que representan canales someros, efímeros, además de coladas de arenisca fina. Depósitos de tipo “flash flood” se presentan en la parte alta de las capas rojas superiores, donde éstas muestran un solapado hacia el SSE, llegando a descansar directamente sobre la superficie meteorizada de un granito. Restos de tronco de coníferas y/o Cordaitales se encuentran en buena parte de las capas rojas superiores. Corresponden a árboles que vivían sobre un paleorelieve en el borde de la cuenca, y que fueron desarraigados por la movilización de los suelos convertidos en corrientes densas que los llevaron a la cuenca. Procesos volcánicos residuales habrán favorecido una silicificación de los troncos por el relleno de las células de madera. Hay niveles de caliche en la parte alta de las capas rojas superiores. Los elementos de flora hallados en los sedimentos lacustres pertenecen a esfenópsidas, helechos, pteridospermas, y cordaites, además de raros troncos de licópsida; es una asociación de facies húmeda. Los restos de flora, de buena preservación, representan unos 40 taxones, de los que se figuran varios. Caracterizan al “Rotliegend” inferior (Autuniense medio). Follaje de coníferas solamente se encontró en una localidad, y no hay más de un solo registro de peltaspermácea. Se compara con el Autuniense de Guadalcanal, a unos 30 km de Valdeviar. Allí se han registrado también floras de régimen lacustre. Se describen cortes estratigráficos parciales, así como los procesos sedimentarios más característicos, con los dibujos y fotos correspondientes. Se facilitan también ilustraciones de algunos icnofósiles. Una sucesión de capas rojas color ladrillo y que muestra un desarrollo fuerte de caliches, es atribuída al Triásico. Se encuentra en paraconformidad en la parte Sur de la depresión de Valdeviar. Se comentan las condiciones tectónicas y paleogeográficas de la cuenca del Pérmico inferior
Luminescence in Slipped and Dislocation-Free Laser-Annealed Silicon
Photoluminescence of cw laser-annealed silicon shows a dramatic difference in electronic behavior of the reconstructed material depending upon either creation or suppression of dislocations. Beyond a critical exposure time slip appears, and the luminescence of these samples is dominated by dislocation-related defect levels
Investigation of the performance of an optimised MicroCAT, a GEM and their combination by simulations and current measurements
A MicroCAT (Micro Compteur A Trous) structure which is used for avalanche
charge multiplication in gas filled radiation detectors has been optimised with
respect to maximum electron transparency and minimum ion feedback. We report on
the charge transfer behaviour and the achievable gas gain of this device. A
three-dimensional electron and ion transfer simulation is compared to results
derived from electric current measurements. Similarly, we present studies of
the charge transfer behaviour of a GEM (Gas Electron Multiplier) by current
measurements and simulations. Finally, we investigate the combination of the
MicroCAT and the GEM by measurements with respect to the performance at
different voltage settings, gas mixtures and gas pressures.Comment: 26 pages, 32 figure
The anatomy of the tendon of the Infundibulum revisited
The heart is a muscular organ supported by collagenous tissue. The collagenous
tissue is condensed in certain areas to form a supporting framework, often called the fibrous skeleton. The so-called tendon of the infundibulum
has previously been described as part of this skeleton, but its structure and
incidence remain ill defined. The tendon was initially described as a strip of
fibrous tissue running between the aortic root and the pulmonary trunk. Since information on its structure is vague, we sought to evaluate its existence in 100 formalin-fixed adult human hearts obtained from subjects ranging in age from 22 to 86 years, in 20 hearts from infants and children aged from 2 months to 6 years at the time of their death and in 10 cattle hearts. We used classical macroscopic anatomical techniques to demonstrate all the possible connections between the sinuses of the aorta and the pulmonary trunk. We then supplemented the macroscopic techniques with serial transverse histological sections taken through the vascular roots, staining the sections with the haematoxylin-eosin, van Gieson, Masson trichrome and orcein staining methods. Fascial bands surrounded by connective tissue were observed in all hearts. In 80 adult hearts and in 16 neonatal hearts we found fascial bands or strips, which connected the aortic and pulmonary roots. Only in two hearts, however, were we able to identify tendon-like structures, and histology revealed that these were formed by tightly packed collagen fibres intermingled with fat, most likely due to advanced age. Thus in those cases where a "tendon" was present it was no more than condensed fascial bands joining together the apposing sinuses of the arterial trunks. In our opinion, therefore, accounts in the literature describing the "tendon of the infundibulum" as a tendinous structure connecting the aortic and pulmonary roots do not accurately represent
this anatomical structure
Submergence of the Sidebands in the Photon-assisted Tunneling through a Quantum Dot Weakly Coupled to Luttinger Liquid Leads
We study theoretically the photon-assisted tunneling through a quantum dot
weakly coupled to Luttinger liquids (LL) leads, and find that the zero bias dc
conductance is strongly affected by the interactions in the LL leads. In
comparison with the system with Fermi liquid (FL) leads, the sideband peaks of
the dc conductance become blurring for 1/2<g<1, and finally merge into the
central peak for g<1/2, (g is the interaction parameter in the LL leads). The
sidebands are suppressed for LL leads with Coulomb interactions strong enough,
and the conductance always appears as a single peak for any strength and
frequency of the external time-dependent field. Furthermore, the quenching
effect of the central peak for the FL case does not exist for g<1/2.Comment: 9 pages, 4 figure
Agent-Based Simulations with Beliefs and SPARQL-Based Ask-Reply Communication
Abstract. We present the result of extending an agent-based simulation framework by adding a full-fledged model of beliefs and by supporting ask-reply communication with the help of the W3C RDF query language SPARQL. Beliefs are the core component of any cognitive agent archi-tecture. They are also the basis of ask-reply communication between agents, which allows social learning. Our approach supports the concep-tual distinctions between facts and beliefs, and between sincere answers and lies
Combinations of Synovex and Finaplex for Yearling Steers
One hundred twenty-three yearling black baldy steers were fed in one pen for 123 days at a commercial feedlot near Kimball, South Dakota. On day 1 in the feedlot, 53 steers were implanted with Synovex-S, 53 steers were implanted with the combination of Synovex-S and Finaplix-S and 17 steers received no implant. On day 60 in the feedlot, 18 of the Synovex-S steers and 18 of the combination steers were reimplanted using Synovex-S. Also on day 60, 18 of the Synovex-S steers and 18 of the combination steers were reimplanted using the combination of Synovex-S and Finaplix-S. The remaining steers were not reimplanted. Average daily gain, carcass weight, rib fat thickness, rib eye area and numerical yield grade were increased (P\u3c.05) while marbling score and the percentage of cattle grading Choice were reduced (P\u3c.10) for implanted steers as compared with nonimplanted steers. Steers implanted on day 1 with the combination gained faster (P\u3c.0246) and exhibited larger (P\u3c.0168) rib eyes than steers implanted on day 1 with only Synovex-S. Reimplanting on day 60 did not significantly improve average daily gain above day 1 implanting only. Percentage of implants found in acceptable position with no infection or encapsulation 2 wk postimplanting was 85.31 for Synovex-S and 60.23 for Finaplix-S
P33. Expression of alpha v beta 3 integrin in patients with high and low grade glioma
Fuente Fuente, Carlos;Puig-Pey, J.;Buenaño Pastor, Manue
Near-Limb Zeeman and Hanle Diagnostics
"Weak" magnetic-field diagnostics in faint objects near the bright solar disk
are discussed in terms of the level of non-object signatures, in particular, of
the stray light in telescopes. Calculated dependencies of the stray light
caused by diffraction at the 0.5-, 1.6-, and 4-meter entrance aperture are
presented. The requirements for micro-roughness of refractive and reflective
primary optics are compared. Several methods for reducing the stray light (the
Lyot coronagraphic technique, multiple stages of apodizing in the focal and
exit pupil planes, apodizing in the entrance aperture plane with a special
mask), and reducing the random and systematic errors are noted. An acceptable
level of stray light in telescopes is estimated for the V-profile recording
with a signal-to-noise ratio greater than three. Prospects for the limb
chromosphere magnetic measurements are indicated.Comment: 11 pages, 3 figure
Follow-up study of sensory-motor polyneuropathy in Type 1 (insulin-dependent) diabetic subjects after simultaneous pancreas and kidney transplantation and after graft rejection
The influence of successful simultaneous pancreas and kidney transplantation on peripheral polyneuropathy was investigated in 53 patients for a mean observation period of 40.3 months. Seventeen patients were followed-up for more than 3 years. Symptoms and signs were assessed every 6 months using a standard questionnaire, neurological examination and measurement of sensory and motor nerve conduction velocities. While symptoms of polyneuropathy improved (pain, paraesthesia, cramps, restless-legs) and nerve conduction velocity increased, there was no change of clinical signs (sensation, muscle-force, tendon-reflexes). Following kidney-graft-rejection there was a slight decrease of nerve conduction verlocity during the first year, which was not statistically significant. Following pancreas-graft rejection there was no change of nerve conduction velocity during the first year. Comparing the maximum nerve conduction velocity of the patients with pancreas-graft-rejection to the nerve conduction velocities of these patients at the end of the study, there was a statistically significant decrease of 6.5 m/s.
In conclusion, we believe that strict normalization of glucose metabolism alters the progressive course of diabetic polyneuropathy. It may be stabilized or partly reversed after successful grafting even in long-term diabetic patients
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