819 resultados para Pere Dorchal


Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper deals with the relationship between the periodic orbits of continuous maps on graphs and the topological entropy of the map. We show that the topological entropy of a graph map can be approximated by the entropy of its periodic orbits.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background Efforts to identify novel therapeutic options for human pancreatic ductal adenocarcinoma (PDAC) have failed to result in a clear improvement in patient survival to date. Pancreatic cancer requires efficient therapies that must be designed and assayed in preclinical models with improved predictor ability. Among the available preclinical models, the orthotopic approach fits with this expectation, but its use is still occasional. Methods An in vivo platform of 11 orthotopic tumor xenografts has been generated by direct implantation of fresh surgical material. In addition, a frozen tumorgraft bank has been created, ensuring future model recovery and tumor tissue availability. Results Tissue microarray studies allow showing a high degree of original histology preservation and maintenance of protein expression patterns through passages. The models display stable growth kinetics and characteristic metastatic behavior. Moreover, the molecular diversity may facilitate the identification of tumor subtypes and comparison of drug responses that complement or confirm information obtained with other preclinical models. Conclusions This panel represents a useful preclinical tool for testing new agents and treatment protocols and for further exploration of the biological basis of drug responses.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Outcrops of old strata at the shelf edge resulting from erosive gravity-driven flows have been globally described on continental margins. The reexposure of old strata allows for the reintroduction of aged organic carbon (OC), sequestered in marine sediments for thousands of years, into the modern carbon cycle. This pool of reworked material represents an additional source of C-14-depleted organic carbon supplied to the ocean, in parallel with the weathering of fossil organic carbon delivered by rivers from land. To understand the dynamics and implications of this reexposure at the shelf edge, a biogeochemical study was carried out in the Gulf of Lions (Mediterranean Sea) where erosive processes, driven by shelf dense water cascading, are currently shaping the seafloor at the canyon heads. Mooring lines equipped with sediment traps and current meters were deployed during the cascading season in the southwestern canyon heads, whereas sediment cores were collected along the sediment dispersal system from the prodelta regions down to the canyon heads. Evidence from grain-size, X-radiographs and Pb-210 activity indicate the presence in the upper slope of a shelly-coarse surface stratum overlying a consolidated deposit. This erosive discontinuity was interpreted as being a result of dense water cascading that is able to generate sufficient shear stress at the canyon heads to mobilize the coarse surface layer, eroding the basal strata. As a result, a pool of aged organic carbon (Delta C-14 = -944.5 +/- 24.7%; mean age 23,650 +/- 3,321 ybp) outcrops at the modern seafloor and is reexposed to the contemporary carbon cycle. This basal deposit was found to have relatively high terrigenous organic carbon (lignin = 1.48 +/- 0.14 mg/100 mg OC), suggesting that this material was deposited during the last low sea-level stand. A few sediment trap samples showed anomalously depleted radiocarbon concentrations (Delta C-14 = -704.4 +/- 62.5%) relative to inner shelf (Delta C-14 = -293.4 +/- 134.0%), mid-shelf (Delta C-14 = -366.6 +/- 51.1%), and outer shelf (Delta C-14 = -384 +/- 47.8%) surface sediments. Therefore, although the major source of particulate material during the cascading season is resuspended shelf deposits, there is evidence that this aged pool of organic carbon can be eroded and laterally advected downslope.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

El reto de la plena ciudadanía es uno de los objetivos actuales en los discursos sociales y, entre ellos, los discursos relativos a las políticas de juventud. El objetivo es justamente superar el debate teórico y discursivo y entrar en el análisis de la práctica experimentada de la ciudadanía, aquella que capacita justamente para el ejercicio práctico de los derechos reconocidos y que no tiene otra forma de lograrlo que a través del ejercicio práctico y aplicado de este derecho. Desde esta posición la finalidad de las políticas de juventud es garantizar la posibilidad y la calidad de todos los procesos que permiten hablar del ejercicio de una plena ciudadanía. Por eso hay que favorecer la emancipación juvenil entendida como el acceso a una vivienda y a un trabajo digno, pero también haber recibido una educación de calidad, tener acceso a la cultura o no estar sometido a ningún tipo de exclusión social. Por tanto, la evaluación de toda política de juventud deberá incorporar elementos para considerar la efectividad de las acciones emprendidas desde una perspectiva de integridad para favorecer la plena ciudadanía. En esta aportación presentamos una propuesta de evaluación desde esta perspectiva. El SIAPJove se concibe como una herramienta para la autoevaluación y para el análisis de la propia acción municipal en políticas de juventud. Útil para ayudar a describir la situación en que se encuentran las políticas municipales de juventud, detectar tendencias, contribuir a establecer objetivos y medir la eficacia de las políticas y los programas de juventud en el ámbito municipal. Presentamos los principales objetivos de evaluación de este sistema, el proceso de validación realizado para la construcción de este instrumento y su estructura básica como herramienta útil para la evaluación de políticas municipales de juventud

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this work, we investigate heterojunction emitters deposited by Hot-Wire CVD on p-type crystalline silicon. The emitter structure consists of an n-doped film (20 nm) combined with a thin intrinsic hydrogenated amorphous silicon buffer layer (5 nm). The microstructure of these films has been studied by spectroscopic ellipsometry in the UV-visible range. These measurements reveal that the microstructure of the n-doped film is strongly influenced by the amorphous silicon buffer. The Quasy-Steady-State Photoconductance (QSS-PC) technique allows us to estimate implicit open-circuit voltages near 700 mV for heterojunction emitters on p-type (0.8 Ω·cm) FZ silicon wafers. Finally, 1 cm 2 heterojunction solar cells with 15.4% conversion efficiencies (total area) have been fabricated on flat p-type (14 Ω·cm) CZ silicon wafers with aluminum back-surface-field contact.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

How can municipal sociocultural policies stimulate and promote community empowerment, civic creativity or social cohesion? What objectives should be proposed at the municipal level to promote processes of sociocultural community development? How can we identify local needs in order to stimulate community development processes? In response to these questions, our paper proposes a creative solution: indicators to evaluate sociocultural policies. The proposal will enable us to obtain information about our own reality and, at the same time, contribute to producing changes and to outlining possible de intervention strategies for local administrations. The proposal describes a system of creative, flexible and rigourous indicators intended for municipal technicians and politicians interested in evaluating their sociocultural actions and strategies. We present the result of a research process whose methods included validation of the indicators by experts and technicians in or related to sociocultural community development, and the application of this system based on a case study of a Spanish municipality. Among the proposed indicators specific consideration is given to the support of local creators and the promotion of civic creativity, as well as the use, the creation and the articulation of sociocultural activities as strategies to contribute to cultural and civic diversity

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In times of crisis, the youth policies are experiencing enormous cutbacks and transformations to the point that we are wondering whether they really exist as public policies with their own entity. The situation in which many young people find themselves in Spain leads them to wonder where the traditional protection networks are: The family, the NGO’s or the Welfare State, when they are really needed. Our objective in this article is to show and discuss the situation of the youth policies in Spain in the present context of social austerity and drastic cutbacks. We carry out this analysis from the parameters of the magical triangle that unite policies, research and social work with young people

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The structural relaxation of pure amorphous silicon a-Si and hydrogenated amorphous silicon a-Si:H materials, that occurs during thermal annealing experiments, has been analyzed by Raman spectroscopy and differential scanning calorimetry. Unlike a-Si, the heat evolved from a-Si:H cannot be explained by relaxation of the Si-Si network strain but it reveals a derelaxation of the bond angle strain. Since the state of relaxation after annealing is very similar for pure and hydrogenated materials, our results give strong experimental support to the predicted configurational gap between a-Si and crystalline silicon.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A study on the taxonomy, morphology and anatomy of the lichenicolous species of the genus Cercidospora (Dothideales, incertae sedis) growing on lichens of the genera Lecanora (Lecanoraceae), specifically of the L. polytropa group and the L. saxicola group (i.e. L. muralis sensu auct. group, Protoparmeliopsis spp.), Rhizoplaca (Lecanoraceae) and Squamarina (Stereocaulaceae) is presented. The following species are proposed as new: Cercidospora barrenoana on Rhizoplaca peltata, and C. melanophthalmae on Rhizoplaca melanophthalma. C. stenotropae is proposed provisionally; this fungus grows on Lecanora stenotropa and other taxa of the L. polytropa group. A key for the species of the genus Cercidospora treated is provided.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

El artículo realiza un recorrido por algunas prácticas (los informes) de las y los educadores sociales, revisando la confidencialidad y el respeto a la información sobre las personas a la que acceden estos profesionales, analizando el código deontológico, etc. Se reflexiona sobre si no sería necesario crear un nuevo instrumento propio: el informe socioeducativo. Y se revisan algunas de las características que debería tener. Se aportan algunas propuestas de autorregulación para un manejo"respetuoso" de la información y la confidencialidad y se ofrecen ejemplos de buenas prácticas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

En este trabajo analizamos la actividad tectónica reciente mediante 1)un estudio geomorfológico de los abanicos aluviales y de la red de drenaje, y 2)un estudio de la deslocación vertical de los abanicos aluviales. Como resultado, se han obtenido valores bajos (hasta 0,04) en los índices de elongación de las cuencas, altos (hasta 7,5) en el índice de gradiente, saltos verticales en los abanicos aluviales del Pleistoceno reciente de hasta 20 metros (140 m. acumulados durante el Cuaternario), y estrías de falla con cabeceos muy altos. Todo indica que hay un levantamiento activo en la zona, y que la componente vertical del deslizamiento es más importante aquí que en el resto de la falla de Alhama de Murcia.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Galanin receptor (GalR) subtypes 1-3 linked to central galanin neurons may form heteromers with each other and other types of G protein-coupled receptors in the central nervous system (CNS). These heteromers may be one molecular mechanism for galanin peptides and their N-terminal fragments (gal 1-15) to modulate the function of different types of glia-neuronal networks in the CNS, especially the emotional and the cardiovascular networks. GalR-5-HT1A heteromers likely exist with antagonistic GalR-5-HT1A receptor-receptor interactions in the ascending midbrain raphe 5-HT neuron systems and their target regions. They represent a novel target for antidepressant drugs. Evidence is given for the existence of GalR1-5-HT1A heteromers in cellular models with trans-inhibition of the protomer signaling. A GalR1-GalR2 heteromer is proposed to be a galanin N-terminal fragment preferring receptor (1-15) in the CNS. Furthermore, a GalR1-GalR2-5-HT1A heterotrimer is postulated to explain why only galanin (1-15) but not galanin (1-29) can antagonistically modulate the 5-HT1A receptors in the dorsal hippocampus rich in gal fragment binding sites. The results underline a putative role of different types of GalR-5-HT1A heteroreceptor complexes in depression. GalR antagonists may also have therapeutic actions in depression by blocking the antagonistic GalR-NPYY1 receptor interactions in putative GalR-NPYY1 receptor heteromers in the CNS resulting in increases in NPYY1 transmission and antidepressant effects. In contrast the galanin fragment receptor (a postulated GalR1-GalR2 heteromer) appears to be linked to the NPYY2 receptor enhancing the affinity of the NPYY2 binding sites in a putative GalR1-GalR2-NPYY2 heterotrimer. Finally, putative GalR-α2-adrenoreceptor heteromers with antagonistic receptor-receptor interactions may be a widespread mechanism in the CNS for integration of galanin and noradrenaline signals also of likely relevance for depression

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Los materiales silricos, devnicos que constituyen el sinclinal de Llavors (Pirineo central) estn atravesados por dos grupos principales de rocas gneas hipoabisales. El primer grupo esta formado por rocas de composicin bsica e intermedis afectadas por un metamorfismo herciniano de grado muy bajo y forman parte, por tanto, de un episodio magmtico bsico anterior a las deformaciones principales hercinianas. Las transformaciones secundarias sufridas por estas rocas impiden deducir, apartir del estudio de 10s elementos mayores, su pertenencia a una serie ignea determinada si bien pueden distinguirse claramente dos asociaciones con distintas relaciones Mg/Fe. El segundo grupo, claramente postectnico, est constituido nicamente por rocas cidas (felsitas y prfidos granticos y granodioriticos), relacionadas aparentemente con el plutonismo calcoalcalino tardi-herciniano.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

En esta nota se estudian las reacciones tectónicas entre diversas unidades del Prepirineo español (prov. de Lrida), junto a la zona axial pirenaica. El estudio tectnico permite evidenciar el carácter alóctono de la Unidad Montsec de Tost (terminación oriental de la denominada Zona de los Nogueras) y la existencia de dos fases tectónicas perfectamente diferenciadas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The hercynian outcrops of the Catalonian Coastal Ranges (NE Spain) consist mainly of Lower Permian-Upper Carboniferous, post-tectonic, epizona1 granitoid intrusions which form a typical applutonic calc-alkaline suite ranging from mafic hornblende gabbros and ultramafic olivine homblendites throught on alites and granodioritcs to leucogranites. This suite displays major andtrace-element characteristics and Sr isotope ratios similar to volcanic arc and post-collision magmatism oceanic lithosphere and to have been modified by contamination and is therefore believed to have formed above subducted with melts from the crust