915 resultados para Comparative Cytoarchitectonic Analysis


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Nearly all metazoan homeodomains (HDs) possess DNA binding targets that are related by the presence of a TAAT sequence. We use an in vitro genetic DNA binding site selection assay to refine our understanding of the amino acid determinants for the recognition of the TAAT site. Superimposed upon the conserved ability of metazoan HDs to recognize a TAAT core is a difference in their preference for the bases that lie immediately 3' to it. Amino acid position 50 of the HD has been shown to discriminate among these base pairs, and structural studies have suggested that water-mediated hydrogen bonds and van der Waals contacts underlie for this ability. Here, we show that each of six amino acids tested at position 50 can confer a distinct DNA binding specificity.

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We have employed an inverse engineering strategy based on quantitative proteome analysis to identify changes in intracellular protein abundance that correlate with increased specific recombinant monoclonal antibody production (qMab) by engineered murine myeloma (NSO) cells. Four homogeneous NSO cell lines differing in qMab were isolated from a pool of primary transfectants. The proteome of each stably transfected cell line was analyzed at mid-exponential growth phase by two-dimensional gel electrophoresis (2D-PAGE) and individual protein spot volume data derived from digitized gel images were compared statistically. To identify changes in protein abundance associated with qMab clatasets were screened for proteins that exhibited either a linear correlation with cell line qMab or a conserved change in abundance specific only to the cell line with highest qMab. Several proteins with altered abundance were identified by mass spectrometry. Proteins exhibiting a significant increase in abundance with increasing qMab included molecular chaperones known to interact directly with nascent immunoglobulins during their folding and assembly (e.g., BiP, endoplasmin, protein disulfide isomerase). 2D-PAGE analysis showed that in all cell lines Mab light chain was more abundant than heavy chain, indicating that this is a likely prerequisite for efficient Mab production. In summary, these data reveal both the adaptive responses and molecular mechanisms enabling mammalian cells in culture to achieve high-level recombinant monoclonal antibody production. (C) 2004 Wiley Periodicals, Inc.

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In this paper, we review evidence from comparative studies of primate cortical organization, highlighting recent findings and hypotheses that may help us to understand the rules governing evolutionary changes of the cortical map and the process of formation of areas during development. We argue that clear unequivocal views of cortical areas and their homologies are more likely to emerge for 'core' fields, including the primary sensory areas, which are specified early in development by precise molecular identification steps. In primates, the middle temporal area is probably one of these primordial cortical fields. Areas that form at progressively later stages of development correspond to progressively more recent evolutionary events, their development being less firmly anchored in molecular specification. The certainty with which areal boundaries can be delimited, and likely homologies can be assigned, becomes increasingly blurred in parallel with this evolutionary/developmental sequence. For example, while current concepts for the definition of cortical areas have been vindicated in allowing a clarification of the organization of the New World monkey 'third tier' visual cortex (the third and dorsomedial areas, V3 and DM), our analyses suggest that more flexible mapping criteria may be needed to unravel the organization of higher-order visual association and polysensory areas.

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Sex determination represents a critical bifurcation in the road of embryonic development. It is based on a finely regulated network of gene activity, as well as protein-protein interactions and activation or silencing of signaling pathways. Despite the identification of a number of critical genes, many aspects of the molecular cascade that drives the differentiation of the embryonic gonad into either a testis or an ovary remain poorly understood. To identify new proteins involved in this cascade, we employed two-dimensional gel electrophoresis and mass spectrometry to compare the protein expression profiles of fetal mouse testes and ovaries. Three proteins, hnRPA1, TRA1, and HSC71, were found to be expressed in a male-specific manner and this expression was confirmed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) and in situ hybridization. Moreover, HSC71 was found to be hyperphosphorylated in male compared to female gonads, emphasizing the advantage of the proteomic approach in allowing the detection of posttranslational modifications.

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Current initiatives in the field of Business Process Management (BPM) strive for the development of a BPM standard notation by pushing the Business Process Modeling Notation (BPMN). However, such a proposed standard notation needs to be carefully examined. Ontological analysis is an established theoretical approach to evaluating modelling techniques. This paper reports on the outcomes of an ontological analysis of BPMN and explores identified issues by reporting on interviews conducted with BPMN users in Australia. Complementing this analysis we consolidate our findings with previous ontological analyses of process modelling notations to deliver a comprehensive assessment of BPMN.

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The advent of Internet banking and phone banking is changing the role of bank branches from a predominantly transaction-based one to a sales-oriented role. This paper reports on an assessment of the branches of a Portuguese bank in terms of their performance in their new roles in three different areas: Their efficiency in fostering the use of new transaction channels, their efficiency in increasing sales and their customer base, and their efficiency in generating profits. Service quality is also a major issue in service organisations like bank branches, and therefore we analyse the way this dimension of performance has been accounted for in the literature and take it into account in our empirical application. We have used data envelopment analysis (DEA) for the different performance assessments, but we depart from traditional DEA models in some cases. Performance comparisons on each dimension allowed us to identify benchmark bank branches and also problematic bank branches. In addition, we found positive links between operational and profit efficiency and also between transactional and operational efficiency. Service quality is positively related with operational and profit efficiency. © 2006 Elsevier B.V. All rights reserved.

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Acknowledgements This work was supported by University of Delhi, Department of Science and Technology- Promotion of University Research and Scientific Excellence (DST-PURSE). V.G., S.H. and U.S. gratefully acknowledge the Council for Scientific and Industrial Research (CSIR), University Grant Commission (UGC) and Department of Biotechnology (DBT) for providing research fellowship.

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This thesis describes two newly sequenced B. longum subsp. longum genomes and subsequent comparative analysis with publicly available B. longum subsp. longum, B. longum subsp. infantis and B. longum subsp. suis genomes (Chapter 2). The acquired data revealed a closed pan-genome for this bifidobacterial species and furthermore facilitated the definition of the B. longum core genome. The comparative analysis also highlights differences in the potential metabolic abilities of all three sub-species. Interestingly, phylogenetic analysis of the B. longum core genome indicated the existence of a novel B. longum subspecies. Characterisation of restriction-modification systems from two B. longum subsp. longum strains is described in Chapter 3. These defence mechanisms limit the uptake of genetic material, which was successfully demonstrated for some of the identified systems. When these systems were by-passed by methylation of DNA prior to the transformation procedure, the resulting transformation efficiency of both B. longum subsp. longum strains was increased to a level that allowed for the generation of mutants via homologous recombination. Arabinoxylan metabolism by B. longum subsp. longum NCIMB 8809 was investigated in Chapter 4 of this thesis. Transcriptome analysis allowed the identification of a number of genes involved in the degradation, uptake and utilisation of arabinoxylan. Biochemical analysis revealed that three of the identified genes encode arabinofuranosidase activity. Phenotypic assessment of a number of insertion mutants in genes identified by the transcriptome analysis revealed the essential role of two of these enzymes in arabinoxylan metabolism, and a third enzyme in the metabolism of debranched arabinan. Furthermore, this investigation revealed that B. longum subsp. longum NCIMB 8809 does not completely degrade arabinoxylan, but utilises the arabinose substitutions only, while leaving the xylan backbone untouched.Finally, Chapter 5 outlines that B. longum subsp. longum NCIMB 8809 is capable of removing ferulic and p-coumaric acid substitutions that originate from arabinoxylan. Analysis of the genome sequence led to the identification of a candidate gene for this activity, which was subsequently cloned and expressed in E. coli. Biochemical analysis revealed that the enzyme, designated here as FaeA, is indeed capable of releasing both ferulic and p-coumaric acid from arabinoxylan. Furthermore, it is shown that a derivative of B. longum subsp. longum NCIMB 8809 carrying an insertion mutation in faeA had lost the ability to release ferulic and p-coumaric acid from arabinoxylan, and that growth of this mutant strain is negatively affected when cultivated on growth-limiting levels of arabinoxylan.

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A universal lack of attention to the professional learning needs of teacher educators is the driver for this study, which considers the most effective ways to support the professional learning of higher education-based teacher educators. At a time when many industrialised countries are engaged in systemic educational reform, this study provides an international and comparative needs analysis through a survey of 1,158 higher education-based teacher educators in the countries participating in the International Forum for Teacher Educator Development (InFo-TED): Belgium, Ireland, Israel, the Netherlands, Norway and the UK. Our results suggest that while teacher educators are only moderately satisfied with their professional development experiences, a strong desire exists for further professional learning. This desire, influenced by their professional context, relates to their current beliefs concerning ‘best practice’ in teacher education, the academic skills required to further their professional careers and knowledge of the curriculum associated with their fields of expertise.

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The asynchronous polyphase induction motor has been the motor of choice in industrial settings for about the past half century because power electronics can be used to control its output behavior. Before that, the dc motor was widely used because of its easy speed and torque controllability. The two main reasons why this might be are its ruggedness and low cost. The induction motor is a rugged machine because it is brushless and has fewer internal parts that need maintenance or replacement. This makes it low cost in comparison to other motors, such as the dc motor. Because of these facts, the induction motor and drive system have been gaining market share in industry and even in alternative applications such as hybrid electric vehicles and electric vehicles. The subject of this thesis is to ascertain various control algorithms’ advantages and disadvantages and give recommendations for their use under certain conditions and in distinct applications. Four drives will be compared as fairly as possible by comparing their parameter sensitivities, dynamic responses, and steady-state errors. Different switching techniques are used to show that the motor drive is separate from the switching scheme; changing the switching scheme produces entirely different responses for each motor drive.

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This paper outlines three information organization frameworks: library classification, social tagging, and boundary infrastructures. It then outlines functionality of these frameworks. The paper takes a neo-pragmatic approach. The paper finds that these frameworks are complementary, and by understanding the differences and similarities that obtain between them, researchers and developers can begin to craft a vocabulary of evaluation.

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The authors present 10 grids which are widely used in Health Sciences for the assessment of quality in research. They proceed through a comparative thematic analysis of these grids and show which points of view are preferred. They insist on the issues that differentiate these grids from each other and suggest the analysis of their differences by distinguishing the theoretical perspectives that underpin each one of these grids. Whilst the authors of the assessment grids rarely refer to the implicit theoretical backgrounds that guide their work, findings show that these grids convey varied epistemologies and research models. This gap renders the comparison of quality assessment in qualitative research a very difficult task, unless we shift our focus on the relationship between the grids, their theoretical backgrounds and their specific research subjects.