972 resultados para 3-17-1


Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Changes in the strength of Atlantic meridional overturning circulation (AMOC) are known to have profound impacts on global climate. Coupled modelling studies have suggested that, on annual to multi-decadal time scales, a slowdown of AMOC causes a deepening of the thermocline in the tropical Atlantic. However, this process has been poorly constrained by sedimentary geochemical records. Here, we reconstruct surface (UK'37 Index) and thermocline (TEX86H) water temperatures from the Guinea Plateau Margin (Eastern tropical Atlantic) over the last two glacial-interglacial cycles (~ 192 kyr). These paleotemperature records show that periods of reduced AMOC, as indicated by the d13 C benthic foraminiferal record from the same core, coincide with a reduction in the near-surface vertical temperature gradient, demonstrating for the first time that AMOC-induced tropical Atlantic thermocline adjustment exists on longer, millennial time scales. Modelling results support the interpretation of the geochemical records and show that thermocline adjustment is particularly pronounced in the eastern tropical Atlantic. Thus, variations in AMOC strength appear to be an important driver of the thermocline structure in the tropical Atlantic from annual to multi-millennial time scales.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

RESUMEN Su objetivo esencial: Regular el proceso de la edificación, está basado en 3 grandes pilares: 1.- Completar la configuración legal de los agentes que intervienen en el mismo, fijando sus obligaciones para así establecer las responsabilidades. 2.- Fomentar la calidad de los edificios. 3.- Fijar las garantías a los usuarios frente a los posibles daños. Estos tres fundamentos están intensamente relacionados, ya que, las obligaciones y responsabilidades de los agentes son la base de la constitución de las garantías a los usuarios, definidas mediante los requisitos básicos que deben satisfacer los edificios. Partiendo del análisis cualitativo y cuantitativo del grado de cumplimiento del objetivo de la nueva Ley, elaborado a través del estudio de sus tres pilares fundamentales, proponemos medidas tendentes a la plena entrada en vigor de la misma. Para ello se deberá desarrollar el Real Decreto previsto en la Disposición Adicional 2ª, una vez conseguido el grado de madurez de los sectores de la edificación y del seguro. En todo este proceso de estudio hemos podido apreciar que la objetiva identificación de los daños y en especial los que afectan la estabilidad del edificio, constituye una herramienta fundamental para la correcta atribución de responsabilidades a los agentes, basada en la aplicación de los tres grados de responsabilidad “ex lege” por daños materiales y sus plazos de prescripción surgidos del nuevo régimen impuesto por el art. 17 LOE Para avalar esta propuesta hemos analizado: 1.- El entorno económico, general y pormenorizado al sector de la edificación, en Europa y España durante el período comprendido entre los años 1990 y 2013, años previos y posteriores a la entrada en vigor de la Ley, dada la influencia de los ciclos de actividad producidos en la regulación del sector, las responsabilidades atribuidas a los agentes, el fomento de la calidad y las garantías ofrecidas a los adquirentes. 2.- Las diversas legislaciones sobre responsabilidades y garantías de los agentes de la edificación en los países de nuestro entorno económico. 3.- La gestación de la LOE, incidiendo en la evolución de los últimos borradores y su tramitación parlamentaria. 4.- El desarrollo doctrinal de la Transición desde el régimen de responsabilidades, fijado por el art. 1591 de Código Civil, y su Jurisprudencia, hacia el nuevo régimen de responsabilidades establecido por el art. 17 LOE. En esta tarea además de apreciar la asimilación, por parte de los Jueces y Magistrados, de los principios doctrinales de la LOE, hemos observado la labor de los peritos, de cuya experta identificación de las causas de los daños depende la justa y eficaz atribución de responsabilidades. 5 -. El grado de eficacia de la LOE a la vista de la estadística siniestral, de la que ya hay datos consolidados, tras la cancelación de casi 15.000 expedientes de reclamación a Arquitectos. 6 -. También hemos estudiado el grado de cumplimiento con el usuario y propietario de las garantías previstas en el art. 19 de la Ley y en la D.A. 1ª, los efectos reales alcanzados y las tareas pendientes por delante. Analizando la atribución de responsabilidades a los agentes de la edificación, dentro del primer pilar fundamental de la LOE, hemos estudiado las actuaciones de los peritos expertos y su incidencia en este objetivo, previa selección de casos de gran interés y dificultad. Fruto de ello se han formulado propuestas tendentes a la especialización de este colectivo, evitando conductas “irregulares” que tanto daño provocan a los agentes reclamados como a los propietarios afectados. Este daño es evidente pudiendo ocasionar condenas injustas, enriquecimientos ilícitos o bien falsas expectativas de satisfacción de daños mal dictaminados y costosas e ineficaces reparaciones. De cara a la consecución del pilar de la calidad de la edificación, mediante los requisitos básicos planteados por la LOE y desarrollados por el Código Técnico de la Edificación (Real Decreto 314/2006, de 17 de marzo), hemos procesado datos de expedientes de reclamaciones por daños que afectan a edificios ejecutados bajo el nuevo régimen LOE. Con esta base se han analizado las causas generadoras de las diversas lesiones y su frecuencia para que de este análisis puedan establecerse pautas de actuación para su prevención. Finalmente, tras demostrar que las garantías obligatorias impuestas por la LOE sólo abarcan un pequeño porcentaje de los posibles daños a la edificación, insistimos en la necesidad de la plena eficacia de la Ley mediante la aprobación de todas las garantías previstas y para todo tipo de edificaciones. En suma, se ha diseñado la tesis como una matriz abierta en la que podremos continuar incorporando datos de la evolución de la doctrina, la jurisprudencia y la estadística de los daños en la edificación. ABSTRACT The approval of Law 38/1999 on November 5, 1999, (Official Gazette BOE 266/1999 of 11.6.1999, p. 38925), was the culmination of a long period of over 20 years of gestation for which deep agreements were needed between all stakeholders affected. Although several parliamentary groups denounced its incomplete approval, regarding mandatory guarantees to the purchaser, its enactment caused general satisfaction among most of the the building agents. This assessment remains after fourteen years since its partial enactment. Its essential purpose, “to regulate the building process”, is based on 3 pillars: 1.- To complete the legal configuration of the agents involved in it, setting their obligations in order to establish their responsibilities. 2.- To promote the buildings quality. 3.- To specify users´guarantees against possible buildings damage. These three issues are strongly related, since the obligations and responsibilities of the actors are the basis of the users’guarantees constitution, defined by the basic performance required by buildings. Based on the qualitative and quantitative analysis of the fulfillment of the new law’s objectives, made by monitoring the three pillars, we propose measures to the full enactment of this Directive, by the development of the Royal Decree, provided in its Second Additional Provision, once maturity in the sectors of the building and insurance is achieved. Throughout this process of study we have seen that the skill identification of damage, particularly those affecting the stability of the building, is an essential tool for the proper allocation of responsibilities of the new regime installed by the art. 17 LOE, based on the application of the three degrees of responsibility "ex lege" for property damage and limitation periods. To support this proposal, we have analyzed: 1.- The evolution of the building sector in Europe and Spain during the years before and after the enactment of the Law, due to the influence of cycles of activity produced in industry regulation, the responsibilities attributed to agents, promotion of the quality and the assurances given to acquirers. 2.- The scope of various laws on liability and building agents warranties in the countries of our economic environment. 3.- The long period of LOE generation, focusing on the developments in recent drafts and parliamentary procedure. 4.- The doctrinal development in the Transition from the regime of responsibilities, set by art. 1591 of the Civil Code, and its Jurisprudence, to the new liability regime established by art. 17 LOE. In this task, while we have noted assimilation by the Judges and Magistrates of the doctrinal principles of the LOE, we have also analyzed the work of experts, whose skilled identification of the damage causes helps the fair and efficient allocation of responsibilities. 5 - The effectiveness of the LOE based on knowledge of the siniestral statistics, which are already consolidated data, after the cancellation of nearly 15,000 claims to Architects. 6.- We have also studied the degree of compliance with the user and owner guarantees, established in art. 19 and the D.A. 1th of the LOE, exposing the real effects achieved and the pending tasks ahead. Analyzing the allocation of the building agents´ responsibilities, within the first cornerstone of the LOE, we have studied the expert witnesses actions and their impact on this duty, selecting cases of great interest and difficulty in this aim. The result of this enterprise has been to propose the specialization of this group, avoiding "irregular" behaviors that create as much damage as the agents claimed to affected owners. This damage is evident and can cause wrong convictions, illicit enrichment, false expectations and inefficient and costly damage repairs. In order to achieve the pillar of building quality through the basic requirements set by the LOE and developed by the Technical Building Code (Royal Decree 314/ 2006 of 17 March), we have analyzed records of damage claims involving buildings executed under the new regime LOE. On this basis we have analyzed the root causes of various damages and their frequency, from these data it will be easy to propose lines of action for prevention. Finally, after demonstrating that mandatory warranties imposed by LOE cover only a small percentage of the potential building damage, we emphasize the need for the full effectiveness of the Law by the obligation all the guarantees provided in the art. 19 LOE, and for all types of buildings. In conclusion, this thesis is designed as an open matrix in which we will continue including data on the evolution of the doctrine, jurisprudence and the statistics of the damage to the building.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Hyperacute rejection of pig organs by humans involves the interaction of Galα(1,3)Gal with antibodies and complement. Strategies to reduce the amount of xenoantigen Galα(1,3)Gal were investigated by overexpression of human lysosomal α-galactosidase in cultured porcine cells and transgenic mice. The overexpression of human α-galactosidase in cultured porcine endothelial cells and COS cells resulted in a 30-fold reduction of cell surface Galα(1,3)Gal and a 10-fold reduction in cell reactivity with natural human antibodies. Splenocytes from transgenic mice overexpressing human α-galactosidase showed only a 15–25% reduction in binding to natural human anti-Galα(1,3)Gal antibodies; however, this decrease was functionally significant as demonstrated by reduced susceptibility to human antibody-mediated lysis. However, because there is residual Galα(1,3)Gal and degalactosylation results in the exposure of N-acetyllactosamine residues and potential new xenoepitopes, using α-galactosidase alone is unlikely to overcome hyperacute rejection. We previously reported that mice overexpressing human α1,2-fucosyltransferase as a transgene had ≈90% reduced Galα(1,3)Gal levels due to masking of the xenoantigen by fucosylation; we evaluated the effect of overexpressing α-galactosidase and α1,2-fucosyltransferase on Galα(1,3)Gal levels. Galα(1,3)Gal-positive COS cells expressing α1,3-galactosyltransferase, α1,2-fucosyltransferase, and α-galactosidase showed negligible cell surface staining and were not susceptible to lysis by human serum containing antibody and complement. Thus, α1,2-fucosyltransferase and α-galactosidase effectively reduced the expression of Galα(1,3)Gal on the cell surface and could be used to produce transgenic pigs with negligible levels of cell surface Galα(1,3)Gal, thereby having no reactivity with human serum and improving graft survival.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Murine Hoxd-3 (Hox 4.1) genomic DNA and cDNA and Hoxa-3 (Hox 1.5) cDNA were cloned and sequenced. The homeodomains of Hoxd-3 and Hoxa-3 and regions before and after the homeodomain are highly conserved. Both Hoxa-3 and Hoxa-3 proteins have a proline-rich region that contains consensus amino acid sequences for binding to Src homology 3 domains of some signal transduction proteins. Northern blot analysis of RNA from 8- to 11-day-old mouse embryos revealed a 4.3-kb species of Hoxd-3 RNA, whereas a less abundant 3.0-kb species of Hoxd-3 RNA was found in RNA from 9- to 11-day-old embryos. Two species of Hoxd-3 poly(A)+ RNA, 4.3 and 6.0 kb in length, were found in poly(A)+ RNA from adult mouse kidney, but not in RNA from other adult tissues tested. Hoxd-3 mRNA was detected by in situ hybridization in 12-, 14-, and 17-day-old mouse embryos in the posterior half of the myelencephalon, spinal cord, dorsal root ganglia, first cervical vertebra, thyroid gland, kidney tubules, esophagus, stomach, and intestines.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The development of multi-target drugs for treating complex multifactorial diseases constitutes an active research ield. This kind of drugs has gained much importance as alternative strategy to combination therapy (“cocktail drugs”).1 A common way to design them brings together two different pharmacophores in one single molecule (so-called dyads). Following this idea and being aware that xanthones2 and 1,2,3-triazoles3 possess important pharmacological properties, we combined these two heterocycles in one molecule to create new dyads with improved therapeutic potential. In this work, new xanthone-1,2,3-triazole dyads were prepared from novel (E)-2-(4-arylbut-1-en-3-yn-1-yl)chromones by two different approaches to evaluate their eficiency and sustainability. Both methodologies involved Diels-Alder reactions to build the xanthone core, which were optimized using microwave irradiation as alternative heating method, and 1,3-dipolar cycloadditions to insert the 1,2,3-triazole moiety (Figure 1).4 All final and intermediate compounds were fully characterized by 1D and 2D NMR techniques.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Modern carbonate sedimentation takes place on the northern Mauritanian shelf (20°N), where typical tropical components (e.g. hermatypic reefs, calcareous green algae) are absent. Such deposits are reminiscent of extratropical sediment in the geological record. The tropical open shelf of Mauritania is influenced by large siliciclastic dust input and upwelling, highly fertilizing the ocean, as well as strongly limiting the light penetration. In this context, temperature does not appear to be the steering factor of carbonate production. This thesis describes the depositional system of the Golfe d'Arguin off Mauritania and focuses on environmental conditions that control the depositional pattern, in particular carbonate production. The description of this modern analogue provides a tool for paleoenvironmental interpretation of ancient counterparts. The Golfe d'Arguin is a broad shallow shelf comprising extensive shoals (<10 m water depth; i.e. the Banc d'Arguin) on the inner shelf where waters warm up. The sediments collected in water depths between 4 and 600 m are characterized by mixed carbonate and siliciclastic (dust) deposits. They vary from clean coarse-grained, almost pure carbonate loose sediments to siliciclastic-dominated fine-grained sediments. The carbonate content and sediment grain size show a north-south decreasing pattern through the Golfe d'Arguin and are controlled by the hydraulic regime influenced by wind-driven surface currents, swell, and tidal currents. The carbonate grain association is heterozoan. Components include abundant molluscs, foraminifers, and worm tubes, as well as barnacles and echinoderms, elements that are also abundant in extratropical sediments. The spatial distribution of the sedimentary facies of the Golfe d'Arguin does not display a depth zonation but rather a mosaic (i.e. patchy distribution). The depth and climatic signatures of the different sedimentary facies are determined by taxonomic and ecological investigations of the carbonate-secreting biota (molluscs and foraminifers). While certain planktonic foraminifers and molluscs represent upwelling elements, other components (e.g. mollusc and benthic foraminifer taxa) demonstrate the tropical origin of the sediment. The nutrient-rich (and thus also low light-penetration) conditions are reflected in the fact that symbiotic and photosynthetic carbonate-producing organisms (e.g. hermatypic corals) are absent. The Mauritanian deposits represent an environment that is rare in the modern world but might have been more common in the geological past when global temperatures were higher. Taxonomic and ecological studies allow for distinguishing carbonate sediments formed under either tropical high-nutrient or extratropical conditions, thus improving paleoclimate reconstruction.

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Samples from sutface sediments of the shell, continental slope, and adjacent deep sea regions off West Africa between 27° N and 15° N were investigated with respect to grain size distribution of the total samples, sand contents of the acid insoluble residues, carbonate content of the total samples, and the separate grain size fractions, specific surfaces, colours and mineralogical composition of the clay fractions. The grain size distributions of the total samples of the sediments of the shelf and the continental slope off Spanish-Sahara are controlled mainly by biogenic components. The supply of terrigeneous material in this area is very low. At deeper parts of the continental slope and in the deep sea areas, the relative amounts of carbonate minerals in the sediments are considerably reduced. The prevailing sand contents of the upper slope changes into clay dominance. On the shelf of Mauritania - represented by profiles extending down to 200 m water depth - the grain size is also controlled mainly by biogenic carbonates. Nevertheless, the admixture of fossil silicate components is important, too. The southern parts of the area is investigated are located in a region influenced by sediments of the Senegal River, which especially control the contents of silt and clay. The silicate sands, predominately of quartz, are fossil and form a mixed sediment with younger deposits. The carbonate contents of the different grain size fractions are formed either by sedimentation of carbonate and silicate particles of the respective grain size or by autochtonous disintegration of coarser sediment particles, as shown by the occurence of Mg-rich calcite and especially aragonite in the clay sized fraction. In the northern parts of the area investigated, which have very minute terrigeneous supply, the latter mechanism is the dominant factor, controlling the carbonate contents of the fine grain sized fractions. In the vicinity of the mouth of the Senegal the carbonate contents are influenced by extremely high dilution with terrigencous silicates. Mg-rich calcite and aragonite are produced preferentially in shallow slope and shelf areas up to 500 m of water depth. The specific surfaces of the carbonate-free clay fractions indicate that the clay fractions of the shelfareas with little terrigenous supply consits of relatively coarser particles. Very fine particles are removed and transported towards the deep sea. Lateral differentiation of this kind was not observed in the area off Senegal. The high surface areas, characterizing the clay fractions of this region, are thought to be due to high montmorillonite contents as was found for deep seas sediments. The mineralogical composition of the clay fraction from the southern parts of the area is characterized by high kaolinite and montmorillonite contents, while in the northern illite is predominating. At least two types of montmorillionites are present: in areas influenced by the Senegal mostly one type was found, which could swell to 17; on the shelves and slopes of the other regions the montmorillonite-group is represented by a montmorillonite-mica-type mixed-layer mineral. A "glauconite", found in the sand fraction, which had very similar properties to those of the montmorillonite-mica mixed-layer, is believed to be the source of this mixed-layer-type mineral. Palygorskite is present in all samples out of range of the Senegal supply. It may be an indicator of eolian transported material. The occurence of rich palygorskit deposits in the arid hinterlands emphasizes the terrestrial origin.