949 resultados para Cosine function of operators


Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper reports the findings from a study of the learning of English intonation by Spanish speakers within the discourse mode of L2 oral presentation. The purpose of this experiment is, firstly, to compare four prosodic parameters before and after an L2 discourse intonation training programme and, secondly, to confirm whether subjects, after the aforementioned L2 discourse intonation training, are able to match the form of these four prosodic parameters to the discourse-pragmatic function of dominance and control. The study designed the instructions and tasks to create the oral and written corpora and Brazil’s Pronunciation for Advanced Learners of English was adapted for the pedagogical aims of the present study. The learners’ pre- and post-tasks were acoustically analysed and a pre / post- questionnaire design was applied to interpret the acoustic analysis. Results indicate most of the subjects acquired a wider choice of the four prosodic parameters partly due to the prosodically-annotated transcripts that were developed throughout the L2 discourse intonation course. Conversely, qualitative and quantitative data reveal most subjects failed to match the forms to their appropriate pragmatic functions to express dominance and control in an L2 oral presentation.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The correct development of multicellular organisms depends upon the perception of signals secreted by cells in order to co-ordinate cell differentiation. The Physcomitrella patens genome encodes many components of potential signaling systems, including putative receptor proteins and putative secreted protein ligands, yet at present little characterization of these proteins has been carried out. We are currently attempting to characterize the expression pattern and function of a family of 6 secreted proteins exhibiting homology to PrsS, the ligand that controls self-incompatibility (SI) in Papaver rhoeas (field poppy). In poppy, PrsS interacts a receptor on the surface of pollen tubes, PrpS causing SI by programmed cell death. Homologues of this protein (SPH – S-Protein Homologues) exist in dicotyledonous plants and bryophytes but not in other plant taxa. We aim to determine spatiotemporal expression differences between these proteins via reporter gene analysis and qPCR of cDNA. In addition we are in the process of creating targeted gene knockouts for all 6 of the genes in P. patens. We are also searching for receptors of PrpS in Physcomitrella using a bioinformatic strategy alongside phage display. In accomplishing this we hope to determine the function of a small novel secreted protein family in Physcomitrella but in addition we also hope to elucidate the function of SPH proteins in Arabidopsis.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This thesis argues that the study of narrative television has been limited by an adherence to accepted and commonplace conceptions of endings as derived from literary theory, particularly a preoccupation with the terminus of the text as the ultimate site of cohesion, structure, and meaning. Such common conceptions of endings, this thesis argues, are largely incompatible with the realities of television’s production and reception, and as a result the study of endings in television needs to be re-thought to pay attention to the specificities of the medium. In this regard, this thesis proposes a model of intra-narrative endings, islands of cohesion, structure, and meaning located within television texts, as a possible solution to the problem of endings in television. These intra-narrative endings maintain the functionality of traditional endings, whilst also allowing for the specificities of television as a narrative medium. The first two chapters set out the theoretical groundwork, first by exploring the essential characteristics of narrative television (serialisation, fragmentation, duration, repetition, and accumulation), then by exploring the unique relationship between narrative television and the forces of contingency. These chapters also introduce the concept of intra-narrative endings as a possible solution to the problems of television’s narrative structure, and the medium’s relationship to contingency. Following on from this my three case studies examine forms of television which have either been traditionally defined as particularly resistant to closure (soap opera and the US sitcom) or which have received little analysis in terms of their narrative structure (sports coverage). Each of these case studies provides contextual material on these televisual forms, situating them in terms of their narrative structure, before moving on to analyse them in terms of my concept of intra-narrative endings. In the case of soap opera, the chapter focusses on the death of the long running character Pat Butcher in the British soap EastEnders (BBC, 1985-), while my chapter on the US sitcom focusses on the varying levels of closure that can be located within the US sitcom, using Friends (NBC, 1993-2004) as a particular example. Finally, my chapter on sports coverage analyses the BBC’s coverage of the 2012 London Olympics, and focusses on the narratives surrounding cyclists Chris Hoy and Victoria Pendleton. Each of these case studies identifies their chosen events as intra-narrative endings within larger, ongoing texts, and analyses the various ways in which they operate within those wider texts. This thesis is intended to make a contribution to the emerging field of endings studies within television by shifting the understanding of endings away from a dominant literary model which overwhelmingly focusses on the terminus of the text, to a more televisually specific model which pays attention to the particular contexts of the medium’s production and reception.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In a high mobility two-dimensional electron gas (2DEG) realized in a GaAs/Al0.3Ga0.7As quantum well we observe changes in the Shubnikov-de Haas oscillations (SdHO) and in the Hall resistance for different sample geometries. We observe for each sample geometry a strong negative magnetoresistance around zero magnetic field which consists of a peak around zero magnetic field and of a huge magnetoresistance at larger fields. The peak around zero magnetic field is left unchanged for different geometries.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study concerns the manuscript music book of Robert Edward (c. 1614–c. 1697), minister, author and musician. The manuscript, formerly part of the library at Panmure House, is now held in the National Library of Scotland and is commonly referred to as ‘Robert Edward’s Commonplace Book’ (GB-En MS.9450). The present study is in two parts and begins with an exploration of the physical book, including the structure, compilation, hands and ownership before a second chapter explores the biography of the eponymous owner, contextualising GB-En MS.9450 locally and nationally. The third chapter concerns the function of the manuscript which, it is argued, is closely related to pedagogy. The final three chapters discuss the content of the manuscript, taking in turn the vocal music, instrumental music and the selection of Italian three-part villanelle. The implications for dating and use arising from the first part of this

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Denitrification is a microbially-mediated process that converts nitrate (NO3-) to dinitrogen (N2) gas and has implications for soil fertility, climate change, and water quality. Using PCR, qPCR, and T-RFLP, the effects of environmental drivers and land management on the abundance and composition of functional genes were investigated. Environmental variables affecting gene abundance were soil type, soil depth, nitrogen concentrations, soil moisture, and pH, although each gene was unique in its spatial distribution and controlling factors. The inclusion of microbial variables, specifically genotype and gene abundance, improved denitrification models and highlights the benefit of including microbial data in modeling denitrification. Along with some evidence of niche selection, I show that nirS is a good predictor of denitrification enzyme activity (DEA) and N2O:N2 ratio, especially in alkaline and wetland soils. nirK was correlated to N2O production and became a stronger predictor of DEA in acidic soils, indicating that nirK and nirS are not ecologically redundant.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper reports the results of a postal survey of intermediate care co-ordinators (ICCs) on the organization and delivery of intermediate care services for older people in England, conducted between November 2003 and May 2004. Questionnaires, which covered a range of issues with a variety of quantitative, ‘tick-box’ and open-ended questions, were returned by 106 respondents, representing just over 35% of primary care trusts (PCTs). We discuss the role of ICCs, the integration of local systems of intermediate care provision, and the form, function and model of delivery of services described by respondents. Using descriptive and statistical analysis of the responses, we highlight in particular the relationship between provision of admission avoidance and supported discharge, the availability of 24-hour care, and the locations in which care is provided, and relate our findings to the emerging evidence base for intermediate care, guidance on implementation from central government, and debate in the literature. Whilst the expansion and integration of intermediate care appear to be continuing apace, much provision seems concentrated in supported discharge services rather than acute admission avoidance, and particularly in residential forms of post-acute intermediate care. Supported discharge services tend to be found in residential settings, while admission avoidance provision tends to be non-residential in nature. Twenty-four hour care in non-residential settings is not available in several responding PCTs. These findings raise questions about the relationship between the implementation of intermediate care and the evidence for and aims of the policy as part of NHS modernization, and the extent to which intermediate care represents a genuinely novel approach to the care and rehabilitation of older people.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The trees, hedgerows and woods are current configuration of the tree network in several ecological regions of the world. In Trás–os–Montes region, Northeast of Portugal, they are a traditional component of Terra fria landscape and they could be seen in several forms: scatter trees, fencerows, small woodlots, riparian buffer strips, among others. The extensive livestock systems in this region are based on a set of circuits across the landscape. In this practice, flocks interacts with these structures using them for different functions inducing an influence on the itineraries. Our purpose will be focused on the woody features of landscape regarding their configurations, abundance and spacial distribution; in order to examine how the grazing systems depends on the currency of these formations; particularly how species flocks behaviors are related on. Depending on spatial data, The investigation attain to compare the tree network within the agriculture matrix, to the grazed territory crossed by flocks. From the other side, the importance of spatial data on interpreting the issue by suggesting different parameter that may influence the circuits. The recognition of the pressure exerciced by the occurence of the woody structures on the grazed circuits is possible. We believe that the role of these woody structures features in supporting the tradicional silvopastoral systems has been sufficiently strong for change their distribution pattern.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The accumulation of mannosyl-glycerate (MG), the salinity stress response osmolyte of Thermococcales, was investigated as a function of hydrostatic pressure in Thermococcus barophilus strain MP, a hyperthermophilic, piezophilic archaeon isolated from the Snake Pit site (MAR), which grows optimally at 40 MPa. Strain MP accumulated MG primarily in response to salinity stress, but in contrast to other Thermococcales, MG was also accumulated in response to thermal stress. MG accumulation peaked for combined stresses. The accumulation of MG was drastically increased under sub-optimal hydrostatic pressure conditions, demonstrating that low pressure is perceived as a stress in this piezophile, and that the proteome of T. barophilus is low-pressure sensitive. MG accumulation was strongly reduced under supra-optimal pressure conditions clearly demonstrating the structural adaptation of this proteome to high hydrostatic pressure. The lack of MG synthesis only slightly altered the growth characteristics of two different MG synthesis deletion mutants. No shift to other osmolytes was observed. Altogether our observations suggest that the salinity stress response in T. barophilus is not essential and may be under negative selective pressure, similarly to what has been observed for its thermal stress response. Introduction

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The survival and descent of cells is universally dependent on maintaining their proteins in a properly folded condition. It is widely accepted that the information for the folding of the nascent polypeptide chain into a native protein is encrypted in the amino acid sequence, and the Nobel Laureate Christian Anfinsen was the first to demonstrate that a protein could spontaneously refold after complete unfolding. However, it became clear that the observed folding rates for many proteins were much slower than rates estimated in vivo. This led to the recognition of required protein-protein interactions that promote proper folding. A unique group of proteins, the molecular chaperones, are responsible for maintaining protein homeostasis during normal growth as well as stress conditions. Chaperonins (CPNs) are ubiquitous and essential chaperones. They form ATP-dependent, hollow complexes that encapsulate polypeptides in two back-to-back stacked multisubunit rings, facilitating protein folding through highly cooperative allosteric articulation. CPNs are usually classified into Group I and Group II. Here, I report the characterization of a novel CPN belonging to a third Group, recently discovered in bacteria. Group III CPNs have close phylogenetic association to the Group II CPNs found in Archaea and Eukarya, and may be a relic of the Last Common Ancestor of the CPN family. The gene encoding the Group III CPN from Carboxydothermus hydrogenoformans and Candidatus Desulforudis audaxviator was cloned in E. coli and overexpressed in order to both characterize the protein and to demonstrate its ability to function as an ATPase chaperone. The opening and closing cycle of the Chy chaperonin was examined via site-directed mutations affecting the ATP binding site at R155. To relate the mutational analysis to the structure of the CPN, the crystal structure of both the AMP-PNP (an ATP analogue) and ADP bound forms were obtained in collaboration with Sun-Shin Cha in Seoul, South Korea. The ADP and ATP binding site substitutions resulted in frozen forms of the structures in open and closed conformations. From this, mutants were designed to validate hypotheses regarding key ATP interacting sites as well as important stabilizing interactions, and to observe the physical properties of the resulting complexes by calorimetry.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação de Mestrado, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2014

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Stem cell transplantation holds great promise for the treatment of myocardial infarction injury. We recently described the embryonic stem cell-derived cardiac progenitor cells (CPCs) capable of differentiating into cardiomyocytes, vascular endothelium, and smooth muscle. In this study, we hypothesized that transplanted CPCs will preserve function of the infarcted heart by participating in both muscle replacement and neovascularization. Differentiated CPCs formed functional electromechanical junctions with cardiomyocytes in vitro and conducted action potentials over cm-scale distances. When transplanted into infarcted mouse hearts, CPCs engrafted long-term in the infarct zone and surrounding myocardium without causing teratomas or arrhythmias. The grafted cells differentiated into cross-striated cardiomyocytes forming gap junctions with the host cells, while also contributing to neovascularization. Serial echocardiography and pressure-volume catheterization demonstrated attenuated ventricular dilatation and preserved left ventricular fractional shortening, systolic and diastolic function. Our results demonstrate that CPCs can engraft, differentiate, and preserve the functional output of the infarcted heart.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Estudou-se atraves de um experimento em blocos ao acaso, os efeitos de quatro niveis de nitrogenio, em diferentes condicoes de umidade, sobre os estagios de crescimento, embonecamento, formacao de graos e prdutividade do milho (Zea mays L.) e as relacoes entre a produtividade e os tres primeiros estagios. Os fatores da resposta de producaobaseados na equacao de Doorenbos e Kassam variaram acentuadamente, nao so com os diferentes estatios de crescimento, mas tambem com diferentes niveis de nitrogenio e os diferentes niveis de agua. Assim, esta equacao nao pareceu ser valida para explicar a resposta de produtividade a niveis de agua. Sugeriu-se um equacao linear modificada. Nesta equacao, a intercessao K1 e inclinacao K2 sao os fatores da resposta de producao. Estes fatores para a cultura do milho foram desenvolvidos para todos os quatro estagios de crescimento e nveis de nitrogenio. Pode-se obter uma eficiencia media do uso de agua, em termos de produtividade, de, aproximadamente, 57,5 kg/ha-cm de agua, sendo, contudo, pequeno o incremento, em face dos niveis crescentes de nitrogenio aplicado ate 120 kg/ha. Os coeficientes de cutura (Kc) calculados estao muito abaixo da estimativa da FAO, para todos os niveis de nitrogenio. Por essa razao, deve haver consideravel economica de agua se estes coeficientes forem usados em lugar da estimativa da FAO. A informacao mostradapode imediatamente ser utilizada para turno de irrigacao e para projetos de irrigacao suplementar planejado para as condicoes doe Nordeste do Brasil.