962 resultados para Co-existing


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Travelling wave ion mobility mass spectrometry (TWIM-MS) with post-TWIM and pre-TWIM collision-induced dissociation (CID) experiments were used to form, separate and characterize protomers sampled directly from solutions or generated in the gas phase via CID. When in solution equilibria, these species were transferred to the gas phase via electrospray ionization, and then separated by TWIM-MS. CID performed after TWIM separation (post-TWIM) allowed the characterization of both protomers via structurally diagnostic fragments. Protonated aniline (1) sampled from solution was found to be constituted of a ca. 5:1 mixture of two gaseous protomers, that is, the N-protonated (1a) and ring protonated (1b) molecules, respectively. When dissociated, 1a nearly exclusively loses NH3, whereas 1b displays a much diverse set of fragments. When formed via CID, varying populations of 1a and 1b were detected. Two co-existing protomers of two isomeric porphyrins were also separated and characterized via post-TWIM CID. A deprotonated porphyrin sampled from a basic methanolic solution was found to be constituted predominantly of the protomer arising from deprotonation at the carboxyl group, which dissociates promptly by CO2 loss, but a CID-resistant protomer arising from deprotonation at a porphyrinic ring NH was also detected and characterized. The doubly deprotonated porphyrin was found to be constituted predominantly of a single protomer arising from deprotonation of two carboxyl groups. Copyright (C) 2012 John Wiley & Sons, Ltd.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Staphylococcus aureus and Staphylococcus epidermidis are leading pathogens of implant-related infections. This study aimed at investigating the diverse distribution of different bacterial pathogen factors in most prevalent S. aureus and S. epidermidis strain types causing orthopaedic implant infections. In this study the presence both of the ica genes, encoding for biofilm exopolysaccharide production, and the insertion sequence IS256, a mobile element frequently associated to transposons, was investigated in relationship with the prevalence of antibiotic resistance among Staphylococcus epidermidis strains. The investigation was conducted on 70 clinical isolates derived from orthopaedic implant infections. Among the clinical isolates investigated a dramatic high level of association was found between the presence of ica genes as well as of IS256 and multiple resistance to all the antibiotics tested. Noteworthy, a striking full association between the presence of IS256 and resistance to gentamicin was found, being none of the IS256-negative strain resistant to this antibiotic. This association is probably because of the link of the corresponding aminoglycoside-resistance genes, and IS256, often co-existing within the same staphylococcal transposon. Moreover we investigated the prevalence of aac(6’)-Ie-aph(2’’), aph (3’) IIIa, and ant(4’) genes, encoding for the three forms of aminoglycoside-modifying enzymes (AME), responsible for resistance to aminoglycoside antibiotics. All isolates were characterized by automated ribotyping, so that the presence of antibiotic resistance determinants was investigated in strains exhibiting different ribopatterns. Interestingly, combinations of coexisting AME genes appeared to be typical of specific ribopatterns. 200 S. aureus isolates, categorized into ribogroups by automated ribotyping, i.e. rDNA restriction fragment length polymorphism analysis, were screened for the presence of a panel of adhesins genes, accessory gene regulatory (agr) polymorphisms and toxins. For many ribogroups, characteristic tandem genes arrangements could be identified. Surprisingly, the isolates of the most prevalent cluster, enlisting 27 isolates, were susceptible to almost all antibiotics and never possessed the lukD/lukE gene, thus suggesting the role of factors other than antibiotic resistance and the here investigated toxins in driving the major epidemic clone to the larger success. Afterwards, .in the predominant S. aureus cluster, the bbp gene encoding bone sialoprotein-binding protein appeared a typical virulence trait, found in 93% of the isolates. Conversely, the bbp gene was identified in just 10% of the remaining isolates of the collection. In this cluster, co-presence of bbp with the cna gene encoding collagen adhesin was a pattern consistently observed. These findings indicate a crucial role of both these adhesins, able to bind the most abundant bone proteins, in the pathogenesis of orthopaedic implant infections, there where biomaterials interface bone tissues. Moreover a PCR screening for the ebpS gene, conducted on over two hundred S. aureus clinical isolates from implant related infections revealed the detection of six strains exhibiting an altered amplicon size, shorter than expected. In order to elucidate the sequence changes present in these gene variants, the trait comprised between the primers was analyzed in all six isolates bearing the modification and in four isolates exhibiting the regular amplicon size. From nucleotide translation, the corresponding encoded protein was found to lack an entire peptide segment of 60 amino acids. These variants, missing an entire hydrophobic region, could actually facilitate current structural studies, helping to assess whether the absent domain is strictly necessary for a functional adhesin conformation and its contribution to the topology of the protein. This study suggests that epidemic clones appear to pursue different survival strategies, where adhesins, when present, exhibit diverse importance as virulence factors. A practical message arising from the present study is that strategies for the prevention and treatment of implant orthopaedic infections should target adhesins conjointly present in epidemic clones. Furthermore, the choice of reference strains for testing the anti-infective properties of biomaterials should focus on a selection of the most prevalent clones as they exhibit distinct profiles of adhesins.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Critical limb ischaemia (CLI) is a particularly severe manifestation of lower limb atherosclerosis posing a major threat to both limb and life of affected patients. Besides arterial revascularisation, risk-factor modification and administration of antiplatelet therapy is a major goal in the treatment of CLI patients. Key elements of cardiovascular risk management are smoking cessation and treatment of hyperlipidaemia with dietary modification or statins. Moreover, arterial hypertension and diabetes mellitus should be adequately treated. In CLI patients not suitable for arterial revascularisation or subsequent to unsuccessful revascularisation, parenteral prostanoids may be considered. CLI patients undergoing surgical revascularisation should be treated with beta blockers. At present, neither gene nor stem-cell therapy can be recommended outside clinical trials. Of note, walking exercise is contraindicated in CLI patients due to the risk of worsening pre-existing or causing new ischaemic wounds. CLI patients are oftentimes medically frail and exhibit significant comorbidities. Co-existing coronary heart and carotid as well as renal artery disease should be managed according to current guidelines. Considering the above-mentioned treatment goals, interdisciplinary treatment approaches for CLI patients are warranted. Aim of the present manuscript is to discuss currently existing evidence for both the management of cardiovascular risk factors and treatment of co-existing disease and to deduct specific treatment recommendations.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Our society uses a large diversity of co-existing wired and wireless networks in order to satisfy its communication needs. A cooper- ation between these networks can benefit performance, service availabil- ity and deployment ease, and leads to the emergence of hybrid networks. This position paper focuses on a hybrid mobile-sensor network identify- ing potential advantages and challenges of its use and defining feasible applications. The main value of the paper, however, is in the proposed analysis approach to evaluate the performance at the mobile network side given the mixed mobile-sensor traffic. The approach combines packet- level analysis with modelling of flow-level behaviour and can be applied for the study of various application scenarios. In this paper we consider two applications with distinct traffic models namely multimedia traffic and best-effort traffic.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

OBJECTIVE : To describe the methodology and to present the baseline findings of the Attention-deficit/hyperactivity Disorder Observational Research in Europe (ADORE) study, the primary objective of which is to describe the relationship between treatment regimen prescribed and quality of life of children with ADHD in actual practice. METHODS : In this 2-year prospective observational study, data on diagnosis, prescribed treatment and outcomes of ADHD were collected at seven time points by paediatricians and child psychiatrists on 1,573 children recruited in 10 European countries. The data presented here from the 1,478 patients included in the analyses describe the baseline condition, initial treatment regimen prescribed and quality of life of families with children with ADHD. RESULTS : Patients had a mean age of 9.0 years (SD 2.5) and 84% were male. Physicians diagnoses were made using DSM-IV (43 %), ICD-10 (32%) and both DSM-IV and ICD-10 (12 %). Mean age of awareness of a problem was 5.1 years, suggesting an average delay of approximately 4 years between awareness and diagnosis of ADHD. Baseline ADHD rating scale scores (physicianrated) indicated moderate to severe ADHD. Parent-rated SDQ scores were in agreement and suggested significant levels of co-existing problems. CGI-S, CGAS and CHIPCE scores also indicated significant impairment. Patients were offered the following treatments after the initial assessment: pharmacotherapy (25 %), psychotherapy (19 %), combination of pharmacotherapy and psychotherapy (25 %), other therapy (10 %) and no treatment (21 %). CONCLUSION : The ADORE study shows that ADHD is similarly recognised across 10 European countries and that the children are significantly impaired across a wide range of domains. In this respect, they resemble children described in previous ADHD samples.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

PURPOSE: To elucidate the association of impaired pulmonary status (IPS) and diabetes mellitus (DM) with clinical outcome and the incidences of aortic neck dilatation and type I endoleak after elective endovascular infrarenal aortic aneurysm repair (EVAR). METHODS: In 164 European institutions participating in the EUROSTAR registry, 6383 patients (5985 men; mean age 72.4+/-7.6 years) underwent EVAR. Patients were divided into patients without versus with IPS or with/without DM. Clinical assessment and contrast-enhanced computed tomography (CT) were performed at 1, 3, 6, 12, 18, and 24 months and annually thereafter. Cumulative endpoint analysis comprised death, aortic rupture, type I endoleak, endovascular reintervention, and surgical conversion. RESULTS: Prevalence of IPS was 2733/6383 (43%) and prevalence of DM was 810/6383 (13%). Mean follow-up was 21.1+/-18.4 months. Thirty-day mortality, AAA rupture, and conversion rates did not differ between patients with versus without IPS and between patients with versus without DM. All-cause and AAA-related mortality, respectively, were significantly higher in patients with IPS compared to patients with normal pulmonary status (31.0% versus 19.0%, p<0.0001 and 6.8% versus 3.3%, p = 0.0057) throughout follow-up. In multivariate analysis adjusted for smoking, age, gender, comorbidities, fitness for open repair, co-existing common iliac aneurysm, neck and aneurysm size, arterial angulations, aneurysm classification, endograft oversizing >or=15%, and type of stent-graft, the presence of IPS was not associated with significantly higher rates of aortic neck dilatation (30.6% versus 38.0%, p>0.05) and did not influence cumulative rates of type I endoleak, endovascular reintervention, or conversion to open surgery (p>0.05). Similarly, the presence of DM did not influence the above-mentioned study endpoints. CONCLUSION: In contrast to observations regarding the natural course of AAAs, impaired pulmonary status does not negatively influence aortic neck dilatation, while the presence of diabetes does not protect from these dismal events after EVAR.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

This paper aims to further our understanding of pre-Columbian agricultural systems in the Llanos de Moxos, Bolivia. Three different types of raised fields co-existing in the same site near the community of Exaltación, in north-western Beni, were studied. The morphology, texture and geochemistry of the soils of these fields and the surrounding area were analysed. Differences in field design have often been associated with the diversity of cultural practices. Our results suggest that in the study area differences in field shape, height and layout are primarily the result of an adaptation to the local edaphology. By using the technology of raised fields, pre-Columbian people were able to drain and cultivate soils with very different characteristics, making the land suitable for agriculture and possibly different crops. This study also shows that some fields in the Llanos de Moxos were built to prolong the presence of water, allowing an additional cultivation period in the dry season and/or in times of drought. Nevertheless, the nature of the highly weathered soils suggests that raised fields were not able to support large populations and their management required long fallow periods.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The oceanographic and tectonic conditions of accretionary margins are well-suited for several potential processes governing methane generation, storage and release. To identify the relevant methane evolution pathways in the northern Cascadia accretionary margin, a four-site transect was drilled during Integrated Ocean Drilling Program Expedition 311. The d13C values of methane range from a minimum value of -82.2 per mil on an uplifted ridge of accreted sediment near the deformation front (Site U1326, 1829 mbsl, meters below sea level) to a maximum value of -39.5 per mil at the most landward location within an area of steep canyons near the shelf edge (Site U1329, 946 mbsl). An interpretation based solely on methane isotope values might conclude the 13C-enrichment of methane indicates a transition from microbially- to thermogenically-sourced methane. However, the co-existing CO2 exhibits a similar trend of 13C-enrichment along the transect with values ranging from -22.5 per mil to +25.7 per mil. The magnitude of the carbon isotope separation between methane and CO2 (Ec = 63.8 ± 5.8) is consistent with isotope fractionation during microbially mediated carbonate reduction. These results, in conjunction with a transect-wide gaseous hydrocarbon content composed of > 99.8% (by volume) methane and uniform dDCH4 values (-172 per mil ± 8) that are distinct from thermogenic methane at a seep located 60 km from the Expedition 311 transect, suggest microbial CO2 reduction is the predominant methane source at all investigated sites. The magnitude of the intra-site downhole 13C-enrichment of CO2 within the accreted ridge (Site U1326) and a slope basin nearest the deformation front (Site U1325, 2195 mbsl) is ~ 5 per mil. At the mid-slope site (Site U1327, 1304 mbsl) the downhole 13C-enrichment of the CO2 is ~ 25 per mil and increases to ~ 40 per mil at the near-shelf edge Site U1329. This isotope fractionation pattern is indicative of more extensive diagenetic alteration at sites with greater 13C-enrichment. The magnitude of the 13C-enrichment of CO2 correlates with decreasing sedimentation rates and a diminishing occurrence of stratigraphic gas hydrate. We suggest the decreasing sedimentation rates increase the exposure time of sedimentary organic matter to aerobic and anaerobic degradation, during burial, thereby reducing the availability of metabolizable organic matter available for methane production. This process is reflected in the occurrence and distribution of gas hydrate within the northern Cascadia margin accretionary prism. Our observations are relevant for evaluating methane production and the occurrence of stratigraphic gas hydrate within other convergent margins.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Este trabajo se propuso en lo básico elucidar dos preguntas importantes: 1 - ¿cuál es la conceptualización de la cultura que trabaja en las actuales discusiones sobre la legitimidad de lo popular?; 2 -¿es justa la apropiación de la cultura popular por parte de las instituciones, aunque con ese gesto se esté reconociendo la legitimidad de aquélla? Se ha querido revisar variadas posiciones en esta problemática que van desde lo más actual a lo más tradicional, ambos coexistentes en muchos casos.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Cores from Deep Sea Drilling Project Holes 501, 504B and 505B have an unusual near-vein zonation in basalts. Megascopically, zonation occurs as differently colored strips and zones whose typical thickness does not exceed 6 to 7 cm. Microscopically, the color of zones depends on variably colored clay minerals which are the products of low-temperature hydrothermal alteration in basalt. These differently colored zones form the so called "oxidative" type of alteration of basalts. Another "background," or, less precisely termed, "non-oxidative," type of alteration in basalts is characterized by large-scale, homogeneous replacement of olivine, and filling of vesicles and cracks by an olive-brown or olive-green clay mineral. The compositions of clay minerals of the "background" type of alteration, as well as the composition of co-existing titanomagnetites, were determined with an electron microprobe. There are sharp maxima in potassium and iron content, and minima in alumina, silica, and magnesia in clay minerals in the colored zones near veins. Coloring of clay and rock-forming minerals by iron hydroxides and a decrease of the amount of titanomagnetite, which apparently was the source of redeposited iron, occur frequently in colored zones. We assume that the large-scale "background" alteration in the basalts occurred under the effect of pore waters slowly penetrating through bottom sediments. Faulting can facilitate access of fresh sea water to basalts; thus above the general homogeneous background arise zones of "oxidative" alteration along fractures in basalts. The main factors controlling these processes are time (age of basalt), grain size, temperature, thickness of sedimentary cover, and heat flow.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Ocean Drilling Program Leg 129 recovered chert, porcellanite, and radiolarite from Middle Jurassic to lower Miocene strata from the western Pacific that formed by different processes and within distinct host rocks. These cherts and porcellanites formed by (1) replacement of chalk or limestone, (2) silicification and in-situ silica phase-transformation of bedded clay-bearing biosiliceous deposits, (3) high-temperature silicification adjacent to volcanic flows or sills, and (4) silica phase-transformation of mixed biosiliceous-volcaniclastic sediments. Petrologic and O-isotopic studies highlight the key importance of permeability and time in controlling the formation of dense cherts and porcellanites. The formation of dense, vitreous cherts apparently requires the local addition and concentration of silica. The influence of permeability is shown by two examples, in which: (1) fragments of originally identical radiolarite that were differentially isolated from pore-water circulation by cement-filled fractures were silicified to different degrees, and (2) by the development of secondary porosity during the opal-CT to quartz inversion within conditions of negligible permeability. The importance of time is shown by the presence of quartz chert below, but not above, a Paleogene hiatus at Site 802, indicating that between 30 and 52 m.y. was required for the formation of quartz chert within calcareous-siliceous sediments. The oxygen-isotopic composition for all Leg 129 carbonate- and Fe/Mn-oxide-free whole-rock samples of chert and porcellanite range widely from d18O = 27.8 per mil to 39.8 per mil vs. V-SMOW. Opal-CT samples are consistently richer in 18O (34.1 per mil to 39.3 per mil) than quartz subsamples (27.8 per mil to 35.7 per mil). Using the O-isotopic fractionation expression for quartz-water of Knauth and Epstein (1976) and assuming d18Opore water = -1.0 per mil, model temperatures of formation are 7°-26°C for carbonate-replacement quartz cherts, 22°-25°C for bedded quartz cherts, and 32°-34°C for thermal quartz cherts. Large variations in O-isotopic composition exist at the same burial depth between co-existing silica phases in the same sample and within the same phase in adjacent lithologies. For example, quartz has a wide range of isotopic compositions within a single breccia sample; d18O = 33.4 per mil and 28.0 per mil for early and late stages of fracture-filling cementation, and 31.6 per mil and 30.2 per mil for microcrystalline quartz precipitation within enclosed chert and radiolarite fragments. Similarly, opal-CT d101 spacing varies across lithologic or diagenetic boundaries within single samples. Co-occurring opal-CT and chalcedonic quartz in shallowly buried chert and porcellanite from Sites 800 and 801 have an 8.7 per mil difference in d18O, suggesting that pore waters in the Pigafetta Basin underwent a Tertiary shift to strongly 18O-depleted values due to alteration of underlying Aptian to Albian-Cenomanian volcaniclastic deposits after opal-CT precipitation, but prior to precipitation of microfossil-filling chalcedony.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

El convento de la Tourette se concibe en un marco temporal concreto. Sin embargo sería erróneo limitarse a él a la hora de intentar desentrañar las claves del proyecto y llegar a un entendimiento completo del mismo. Es necesario analizarlo atendiendo al conjunto global de la producción del arquitecto, la cual ha ido forjando una forma propia de hacer que condicionará en gran medida las decisiones tomadas en cada momento. Esta tesis realiza una investigación de doble sentido (recogida en los dos volúmenes que la componen). Por un lado analiza el proceso evolutivo en el que se enhebra la obra intentando desentrañar la influencia de aquel en ésta, pero por otro, invirtiendo el sentido, también desvela ciertas claves de la arquitectura de Le Corbusier a través del preciso análisis de proyecto de la Tourette. Pero aún más, la pertenencia del convento de la Tourette al “tipo monacal” introduce la presencia de un tiempo histórico “ab origine, in hillo tempore” del que la investigación se hace eco. Un tiempo al que Le Corbusier siempre volverá la mirada, y que en este caso se encuentra muy presente, determinando el devenir del proyecto de una forma particular y definitiva. Por tanto este trabajo pretende convocar los dos tiempos que conviven en el proyecto del convento de la Tourette, el corto, concreto y cerrado de su génesis y desarrollo, que se circunscribe al periodo de proyecto comprendido entre los años 1953 y 1956, y el más dilatado, abstracto y abierto, que enlaza el proyecto con la producción de Le Corbusier, y aún más atrás, con el tiempo histórico. En la primera parte del trabajo (A. “PROYECTO”) se realiza un análisis cronológico de la documentación gráfica ‐incluyendo su re‐dibujo‐ y escrita del proyecto, desde los croquis que el arquitecto esboza en su primera visita al valle del Turdine hasta el documento final del project d’exécution, a partir del cual se materializará la obra. El objetivo de la investigación no es describir la realidad construida, sino participar del secreto de su génesis analizando y intentando comprender los dibujos o el pensamiento de sus creadores. Frente a la multitud de escritos sobre la obra del convento de la Tourette el foco de atención de la tesis se centra en el proyecto. Es en esta fase de elaboración y desarrollo de las ideas, previa a la acción de construir, donde pensamos que La deriva de la propia actividad del arquitecto avala esta decisión. A lo largo de su carrera Le Corbusier va reduciendo progresivamente su presencia en la obra centrándose cada vez más en las fases de la concepción y proyecto arquitectónico. Considera que en ellas se produce lo “esencial” mientras que deja las decisiones de obra en manos de sus colaboradores y de los diversos “operadores”, participando tan solo en el visto bueno final de las mismas (esta posición contrasta con la entrega de los constructores para quienes el arquitecto encarna la innovación tecnológica). En la Tourette realiza exclusivamente tres visitas de obra en las que actúa como un mero escenógrafo, ajustando aquí y allá pequeñas decisiones de la construcción. Esta distancia refuerza su posición en el proceso y subraya su búsqueda de un ideal teórico desarrollado sobre todo en la fase de proyecto frente a lo subsidiario de la realidad práctica. En la segunda parte de la tesis, denominada “RE‐VISIONES”, se abre el campo de acción a otras facetas de la ingente actividad de Le Corbusier como la pintura, la escritura o incluso la escultura; una nueva MIRADA bajo el prisma de una serie de conceptos‐llave recurrentes en su Petit vocabulaire (l’homme, la céllule, la bôite, l’organisme). Se amplía, por tanto, el marco temporal, repasando de modo genérico y transversal la evolución de los mismos en la trayectoria del arquitecto, comprobándose como el convento de la Tourette es un eslabón característico y clave en todos ellos. ABSTRACT The Convent of La Tourette is conceived in a specific time frame. However, it would be erroneous to limit oneself simply to this when trying to unravel the keys to the project and to fully understand it. It is necessary to analyse the project attending to the entire production of the architect, who progressively shaped his own way of doing things which would condition to a large extent the decisions taken at each point in time. This thesis carries out its research in a dual sense (brought together in both its volumes). On the one hand, it analyses the development process threading the work attempting to fathom the influence of the former on the latter but, on the other hand, inverting the sense which also reveals certain keys to the architecture of Le Corbusier by means of a detailed analysis of the project for La Tourette. Even more so, the Convent of La Tourette belonging to the “monastic type” introduces the presence of a historical period “ab origine, in hillo tempore" reflected in the research. A period to which Le Corbusier would always look back on and which is extremely present in this case, determining the evolution of the project in a particular and definitive manner. Therefore, this piece of work attempts to bring together both time periods co‐existing in the project for the Convent of La Tourette, the short, specific and closed one regarding its genesis development, encompassing the project period going from 1953 to 1956, and the broader, more abstract and open one linking the project with the production by Le Corbusier, and even further back, with the historical period. The first part of this work (A. “PROJECT") performs a chronological analysis of the graphic – including its re‐drawing –and written documentation of the project, from the outlines the architect sketched in his first visit to the Turdine valley up to the final document of the project d’exécution from which the works would materialise. The main object of the investigation is not intend to describe the reality constructed, but to participate in the secret of its genesis, analysing and trying to understand the drawings or the thoughts of its creators. As opposed to the many writings on the work of the Convent of La Tourette, the attention of this thesis focusses on the project. It is in this preparation and development stage, previous to the construction action, where it is believed the real keys to understand and explain it lie. The enormous work collecting, ordering and analysing the abundant graphic and written information reveals “a multidirectional process, full of regrets and securities, errors and certainties, leaps backwards and tremendous foresight in the process” directed not only by the conditions of the assignment, but also by the way of doing things of Le Corbusier and his collaborator I. Xenakis. A web of hidden relationships is weaved in this open space of the process, often distant in time, allowing us to draw a new route, not only towards the constructed works of the Convent of La Tourette, but towards understanding his entire production. It is in the creation of this new path of knowledge, and not only in its conclusion, where the “thesis” acquires its true meaning. In second place, the drift in the actual activity of the architect backs this decision. Throughout his career, Le Corbusier progressively reduced his presence on site, focussing more and more on the conception and architectural project stages. He considered that which was “essential” took place in these, while leaving the on‐site decisions to his collaborators and the different “operators”, only participating in their final approval (this position is in contrast with the delivery by the constructors for whom the architect embodies the technological innovation). In La Tourette he exclusively made three on‐site visits, in which acted as a pure stage designer, adjusting small construction decisions here and there. This distance reinforces his position in the process and underlines his search for a theoretical ideal developed primarily in the project stage as opposed to that which is secondary of the practical reality. The second part of the thesis, called “RE‐VISIONS”, widens the scope of action to other aspects of the huge activity by Le Corbusier, encompassing painting, writing or even sculpture; a new VIEW under the prism of a series of recurrent key concepts in his Petit vocabulaire (l’homme, la céllule, la bôite, l’organisme). The time frame is therefore extended, revising in a generic and transversal manner the development of these concepts throughout the career of Le Corbusier, confirming how the Convent of La Tourette is a characteristic and key link to each of them.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The mechanisms that underlie the maintenance of and increase in mutant mitochondrial DNA (mtDNA) are central to our understanding of mitochondrial disease. We have therefore developed a technique based on saponin permeabilisation that allows the study of mtDNA synthesis in intact cells. Permeabilisation of cells has been extensively used in an established method both for studying transcription and DNA replication in the nucleus and for measuring respiratory chain activities in mitochondria. We have quantitatively studied incorporation of radiolabelled DNA precursors into mtDNA in human cell lines derived from controls and from patients with mitochondrial DNA disease. Total cell DNA is extracted, restriction digested and Southern blotted, newly synthesised mtDNA being proportional to the label incorporated in each restriction band. A rate of synthesis can then be derived by estimating the relative steady-state mtDNA after probing with full-length mtDNA. Where co-existing mutant and wild-type mtDNA (heteroplasmy) can be distinguished using restriction digestion, their rates of synthesis can be compared within a single cell line. This will be particularly useful in elucidating the pathophysiology of mtDNA diseases in which the distribution of mutant and wild-type mtDNA in cell lines in patient tissues may evolve with time.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Thesis (Master's)--University of Washington, 2016-06