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Arg72Pro TP53 polymorphism and cancer susceptibility: a comprehensive meta-analysis of 302 case-control studies

FRANCISCO, Guilherme; MENEZES, Paulo Rossi; ELUF-NETO, Jose; CHAMMAS, Roger
Fonte: WILEY-BLACKWELL Publicador: WILEY-BLACKWELL
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
55.48%
Arg72Pro is a common polymorphism in TP53, showing differences in its biological functions. Case-control studies have been performed to elucidate the role of Arg72Pro in cancer, although the results are conflicting and heterogeneous. Here, we analyzed pooled data from case-control studies to determine the role of Arg72Pro in different cancer sites. We performed a systematic review and meta-analysis of 302 case-control studies that analyzed Arg72Pro in cancer susceptibility. Odds ratios were estimated for different tumor sites using distinct genetic models, and the heterogeneity between studies was explored using I(2) values and meta-regression. We adopted quality criteria to classify the studies. Subgroup analyses were done for tumor sites according to ethnicity, histological, and anatomical sites. Results indicated that Arg72Pro is associated with higher susceptibility to cancer in some tumor sites, mainly hepatocarcinoma. For some tumor sites, quality of studies was associated with the size of genetic association, mainly in cervical, head and neck, gastric, and lung cancer. However, study quality did not explain the observed heterogeneity substantially. Meta-regression showed that ethnicity, allelic frequency and genotyping method were responsible for a substantial part of the heterogeneity observed. Our results suggest ethnicity and histological and anatomical sites may modulate the penetrance of Arg72Pro in cancer susceptibility. This meta-analysis denotes the importance for more studies with good quality and that the covariates responsible for heterogeneity should be controlled to obtain a more conclusive response about the function of Arg72Pro in cancer.; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq Brasilia...

Metodologia para a coleta e análise de informações sobre consumos e perdas de materiais e componentes nos canteiros de obras de edifícios.; Methodology for collection and analysis of information on materials/components consumption and waste in the building construction sites.

Paliari, José Carlos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 29/09/1999 PT
Relevância na Pesquisa
55.46%
O trabalho desenvolvido propõe uma metodologia para coleta e análise de informações sobre o uso de materiais/componentes nos canteiros de obras. Tal metodologia envolve o levantamento de indicadores globais (envolvem todas as etapas do processo de produção: recebimento, estocagem, processamento intermediário, transporte e aplicação final) e parciais (dizem respeito a uma das etapas do processo) sobre consumos e/ou perdas de materiais/componentes. O correlacionamento de tais avaliações numéricas com as situações vigentes no canteiro, serve de subsídio quanto à geração futura de alternativas para a redução destes índices. A metodologia contempla 19 materiais; sua operacionalização é baseada num conjunto de 7 séries de planilhas contendo procedimentos específicos para a coleta de informações e cálculo dos índices. São definidas também diretrizes para a análise dos resultados. Tais instrumentos garantem a padronização da coleta, do processamento e da análise das informações e, conseqüentemente, permite a comparação entre índices levantados em obras diferentes de quaisquer partes do país.; This work proposes a meticulous methodology for data collection and analysis on materials/components consumption and waste in building construction sites. Such a methodology involves the calculation of global and partial indexes on materials/components consumption and/or waste. While the global ones represent the stages roamed by materials until their final destiny (receiving...

Análise espectral de sinais atriais e sua correlação topográfica com a inervação parassimpática cardíaca; Spectral analysis of atrial signals and its topographic correlation with cardiac parassimpathetic innervation

Rivarola, Esteban Wisnivesky Rocca
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 22/08/2011 PT
Relevância na Pesquisa
55.5%
Objetivo. Verificar se as características espectrais dos eletrogramas atriais (EgA) em ritmo sinusal (RS) se correlacionam com a presença de gânglios parassimpáticos cardíacos. Materiais e Resultados. Treze pacientes encaminhados para submeter-se a ablação de fibrilação atrial (FA) foram incluídos de forma prospectiva. Previamente ao início da ablação, realizou-se o registro de EgA em RS em uma série de regiões anatômicas pré-determinadas, seguindo-se uma ordem sequencial. Em seguida, aplicou-se estímulos elétricos de alta frequência (20 Hz de frequência, amplitude de 100 V e duração de pulso de 4 ms), nos mesmos locais. Uma resposta vagal evocada foi definida como um súbito aumento no intervalo RR ou a indução de bloqueio na condução átrio-ventricular imediatamente após a aplicação do estímulo de alta-frequência (EAF). Procedeu-se à análise espectral dos sinais atriais em RS registrados, com amostragem de 1000 Hz, janela Hanning. No total, 1488 EgA oriundos de 186 locais anatômicos foram registrados, sendo 129 de regiões com resposta vagal negativa e 57 correspondentes a regiões de resposta vagal positiva. A duração do eletrograma e o número de deflecções foram similares nos pontos com resposta vagal positiva e negativa. A densidade de potência espectral em locais de resposta vagal positiva...

Analysis of rain quality data from the South African interior

Galpin, Jacky; Held, Gerhard
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 333-346
ENG
Relevância na Pesquisa
55.51%
Rain acidity may be ascribed to emissions from power station stacks, as well as emissions from other industry, biomass burning, maritime influences, agricultural influences, etc. Rain quality data are available for 30 sites in the South African interior, some from as early as 1985 for up to 14 rainfall seasons, while others only have relatively short records. The article examines trends over time in the raw and volume weighted concentrations of the parameters measured, separately for each of the sites for which sufficient data are available. The main thrust, however, is to examine the inter-relationship structure between the concentrations within each rain event (unweighted data), separately for each site, and to examine whether these inter-relationships have changed over time. The rain events at individual sites can be characterized by approximately eight combinations of rainfall parameters (or rain composition signatures), and these are common to all sites. Some sites will have more events from one signature than another, but there appear to be no signatures unique to a single site. Analysis via factor and cluster analysis, with a correspondence analysis of the results, also aid interpretation of the patterns. This spatio-temporal analysis...

Analysis of Site Frequency Spectra from Arabidopsis with Context-Dependent Corrections for Ancestral Misinference

Morton, Brian R.; Dar, Vaqaar-un-Nisa; Wright, Stephen I.
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /02/2009 EN
Relevância na Pesquisa
65.47%
Previous studies have shown that the pattern of single nucleotide polymorphism (SNP) in Arabidopsis (Arabidopsis thaliana) deviates from the distribution expected under a neutral model. Here, we test whether or not ancestral misinference could explain this deviation. We start by showing that there are significant and complex influences of context on mutation dynamics as inferred from SNP frequency, in Arabidopsis, and compare the results to observations about context dependency that have been made on a previous analysis of a maize (Zea mays) SNP dataset. The data concerning heterogeneity across sites are then used to make corrections for ancestral misinference in a context-dependent manner. Using Arabidopsis lyrata to infer the ancestral state for SNPs, we show that the resulting unfolded site frequency spectrum (SFS) in Arabidopsis is skewed toward sites with high frequency derived nucleotides. Sites are also partitioned into two general functional classes, second codon position and 4-fold degenerate sites. These two classes show different SFS; although both show an overrepresentation of high frequency derived sites, low frequency derived sites are vastly overrepresented at the second codon position, but significantly underrepresented at 4-fold degenerate sites. We find that these results are robust to corrections for ancestral misinference...

Genome-Wide Analysis of Ethylene-Responsive Element Binding Factor-Associated Amphiphilic Repression Motif-Containing Transcriptional Regulators in Arabidopsis1[W][OA]

Kagale, Sateesh; Links, Matthew G.; Rozwadowski, Kevin
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
65.43%
The ethylene-responsive element binding factor-associated amphiphilic repression (EAR) motif is a transcriptional regulatory motif identified in members of the ethylene-responsive element binding factor, C2H2, and auxin/indole-3-acetic acid families of transcriptional regulators. Sequence comparison of the core EAR motif sites from these proteins revealed two distinct conservation patterns: LxLxL and DLNxxP. Proteins containing these motifs play key roles in diverse biological functions by negatively regulating genes involved in developmental, hormonal, and stress signaling pathways. Through a genome-wide bioinformatics analysis, we have identified the complete repertoire of the EAR repressome in Arabidopsis (Arabidopsis thaliana) comprising 219 proteins belonging to 21 different transcriptional regulator families. Approximately 72% of these proteins contain a LxLxL type of EAR motif, 22% contain a DLNxxP type of EAR motif, and the remaining 6% have a motif where LxLxL and DLNxxP are overlapping. Published in vitro and in planta investigations support approximately 40% of these proteins functioning as negative regulators of gene expression. Comparative sequence analysis of EAR motif sites and adjoining regions has identified additional preferred residues and potential posttranslational modification sites that may influence the functionality of the EAR motif. Homology searches against protein databases of poplar (Populus trichocarpa)...

NbIT - A New Information Theory-Based Analysis of Allosteric Mechanisms Reveals Residues that Underlie Function in the Leucine Transporter LeuT

LeVine, Michael V.; Weinstein, Harel
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 01/05/2014 EN
Relevância na Pesquisa
55.48%
Complex networks of interacting residues and microdomains in the structures of biomolecular systems underlie the reliable propagation of information from an input signal, such as the concentration of a ligand, to sites that generate the appropriate output signal, such as enzymatic activity. This information transduction often carries the signal across relatively large distances at the molecular scale in a form of allostery that is essential for the physiological functions performed by biomolecules. While allosteric behaviors have been documented from experiments and computation, the mechanism of this form of allostery proved difficult to identify at the molecular level. Here, we introduce a novel analysis framework, called N-body Information Theory (NbIT) analysis, which is based on information theory and uses measures of configurational entropy in a biomolecular system to identify microdomains and individual residues that act as (i)-channels for long-distance information sharing between functional sites, and (ii)-coordinators that organize dynamics within functional sites. Application of the new method to molecular dynamics (MD) trajectories of the occluded state of the bacterial leucine transporter LeuT identifies a channel of allosteric coupling between the functionally important intracellular gate and the substrate binding sites known to modulate it. NbIT analysis is shown also to differentiate residues involved primarily in stabilizing the functional sites...

Comprehensive Sieve Analysis of Breakthrough HIV-1 Sequences in the RV144 Vaccine Efficacy Trial

Edlefsen, Paul T.; Rolland, Morgane; Hertz, Tomer; Tovanabutra, Sodsai; Gartland, Andrew J.; deCamp, Allan C.; Magaret, Craig A.; Ahmed, Hasan; Gottardo, Raphael; Juraska, Michal; McCoy, Connor; Larsen, Brendan B.; Sanders-Buell, Eric; Carrico, Chris; Men
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 03/02/2015 EN
Relevância na Pesquisa
55.51%
The RV144 clinical trial showed the partial efficacy of a vaccine regimen with an estimated vaccine efficacy (VE) of 31% for protecting low-risk Thai volunteers against acquisition of HIV-1. The impact of vaccine-induced immune responses can be investigated through sieve analysis of HIV-1 breakthrough infections (infected vaccine and placebo recipients). A V1/V2-targeted comparison of the genomes of HIV-1 breakthrough viruses identified two V2 amino acid sites that differed between the vaccine and placebo groups. Here we extended the V1/V2 analysis to the entire HIV-1 genome using an array of methods based on individual sites, k-mers and genes/proteins. We identified 56 amino acid sites or “signatures” and 119 k-mers that differed between the vaccine and placebo groups. Of those, 19 sites and 38 k-mers were located in the regions comprising the RV144 vaccine (Env-gp120, Gag, and Pro). The nine signature sites in Env-gp120 were significantly enriched for known antibody-associated sites (p = 0.0021). In particular, site 317 in the third variable loop (V3) overlapped with a hotspot of antibody recognition, and sites 369 and 424 were linked to CD4 binding site neutralization. The identified signature sites significantly covaried with other sites across the genome (mean = 32.1) more than did non-signature sites (mean = 0.9) (p < 0.0001)...

Genome-wide analysis of transcription factors and chromatin in S. cerevisiae; Genome-wide analysis of transcription factors and chromatin in Saccharomyces cerevisiae

Wyrick, John J. (John Jason), 1974-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 248 leaves; 16552834 bytes; 16552587 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
65.31%
The regulation of transcription initiation is a complex phenomenon, involving DNA-binding activator and repressor proteins, histones and chromatin factors, histone-modifying enzymes, and the general transcription apparatus. Though many of the genes encoding these factors have been identified in yeast, the role they play in regulating the expression of the yeast genome was not known. Genome-wide expression analysis of mutations in the Rpbl subunit of RNA polymerase II, the Srb4 subunit of Srb/Mediator complex, and the Kin28 subunit of TFIIH demonstrated that these factors are required for the transcription of essentially all protein-coding genes in yeast. However, other components of the Srb/Mediator complex (Srb5, Med6, SrblO, Swi2), the general transcription factor TFIID (Taf145, Taf17), and the SAGA histone-modifying complex (Gcn5, Taf17) were found not to be required for the transcription of all yeast genes but for distinct subsets of genes, revealing a surprising level of gene-specific regulation by the general transcription apparatus. The packaging of histones and DNA into nucleosomes was thought to generally repress gene expression, particularly at yeast telomeres, where the Sir protein complex silences genes located in the telomeric heterochromatin. To test this model...

Romantic regressions : an analysis of behavior in online dating systems

Fiore, Andrew Rocco Tresolini, 1979-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 90 p.; 3084841 bytes; 3094833 bytes; application/pdf; application/pdf
EN_US
Relevância na Pesquisa
65.35%
Online personal advertisements have shed their stigma as matchmakers for the awkward to claim a prominent role in the social lives of millions of people. Web sites for online dating allow users to post lengthy personal ads, including text and photos; search the database of users for potential romantic partners; and contact other users through a private messaging system. This work begins with psychological and sociological perspectives on online dating and discusses the various types of online dating Web sites. Next, it presents an analysis of user behavior on one site in particular, which has more than 57,000 active users from the United States and Canada. A demographic description of the population is given, and then 250,000 messages exchanged by the active users over an eight-month period are analyzed. An examination of which characteristics are "bounding" finds that life course attributes such as marital status and whether one wants children are most likely to be the same across the two users in a dyadic interaction. To understand which characteristics are important to users in deciding whom to contact, regression models show the relative strength of a variety of attributes in predicting how many messages a user with those attributes will receive. By far the strongest predictor of messages received is the number of messages sent. For men...

Investigation of the p53-dependent apoptosis versus arrest decision through analysis of Prep gene regulation; Analysis of Prep gene regulation : implications for p53-dependent apoptosis versus arrest decision

Reczek, Elizabeth E. (Elizabeth Emily), 1975-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 230 leaves; 10095503 bytes; 10095309 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
65.29%
The p53 tumor suppressor gene is thought to play a critical role in the maintenance of genetic integrity by virtue of its ability to check the growth of abnormal or damaged cells through initiation of the cell cycle arrest and apoptosis pathways. p53 itself is mutated in roughly half of all human tumors and is likely to be inactivated through mutations in other components of the stress response pathway in the remaining cases, highlighting the centrality of p53 function to effective tumor suppression. The vast majority of p53 mutations disrupt its sequence-specific DNA binding function, compromising its ability to activate a large array of target genes involved in apoptosis, arrest, DNA repair, senescence, differentiation and other cellular functions. While the catalog of target genes is rapidly expanding, our understanding of the effector pathways downstream of p53 and the regulatory networks that govern their expression remains incomplete. Subtle changes in cellular environment and cell type specific factors can drastically affect the decision to pause and repair accumulated damage, or to commit cellular suicide to prevent the propagation of damaged genetic material. Our understanding of this life or death decision is still rudimentary. The work presented here represents an attempt to uncover mechanisms underlying the decision to initiate apoptosis or cell cycle arrest in a simple model system. Mouse embryo fibroblasts normally respond to DNA damage by undergoing cell cycle arrest...

Feasibility analysis of coordinated offshore wind project development in the U.S.

Zhang, Mimi Q
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 67 p.
ENG
Relevância na Pesquisa
65.39%
Wind energy is one of the cleanest and most available resources in the world, and advancements in wind technology are making it more cost effective. Though wind power is rapidly developing in many regions, its variable nature creates obstacles in integrating significant amounts of wind power to the electric grid. One potential solution for reducing the fluctuating nature of wind power is to site wind projects in regions of complementing wind regimes to reduce variability. This thesis explores the feasibility of creating a coordinated network of offshore wind projects through examining its technological requirements, economic viability, and the policy and planning issues of building such a network in the U.S. Wind speed data for sites along the east coast of the U.S. are used to analyze the nature of offshore wind patterns and the benefits of interconnecting multiple wind projects. The main questions are: 1) Is an offshore wind network technologically feasible? 2) What are the costs and benefits of creating an offshore network with transmission lines? 3) What are potential ways to plan, permit, and develop such a network? An overview of research on existing turbine technology, turbine foundation technology, and transmission technology show that it is technically possible to build a network of offshore wind projects. An analysis of the costs and benefits of physical interconnection show that the cost savings from reduced variability pale in comparison to interconnection costs. It is more cost effective to coordinate the siting of all projects within the network...

Qualidade do serviço de informação digital :um estudo exploratório em web sites de Programas de Pós-Graduação; Digital information service quality: an exploratory study in graduate web sites

Oliveira, Adriana Carla Silva de
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia de Produção; Estratégia; Qualidade; Gestão Ambiental; Gestão da Produção e Operações Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Engenharia de Produção; Estratégia; Qualidade; Gestão Ambiental; Gestão da Produção e Operações
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
65.53%
This dissertation of Mestrado investigated the performance and quality of web sites. The target of the research is the proposal of an integrated model of evaluation of services of digital information in web educational sites. The universe of the research was constituted by eighteen Brazilian Universities that offer after-graduation courses, in the levels of mestrado and doutorado in the area of Engineering of Production. The adopted methodology was a descriptive and exploratory research, using the technique of systematic comment and focus group, for the collection of the data, using itself changeable independent dependents and, through the application of two instruments of research. The analysis protocol was the instrument adopted for evaluation and attainment of qualitative results. E the analysis grating was applied for evaluation and attainment of the quantitative results. The qualitative results had identified to the lack of standardization of web sites, under the attributes of content, hierarchy of information, design of the colors and letters. It of accessibility for carriers of auditory and visual special necessities was observed inexistence, as well as the lack of convergence of medias and assistivas technologies. The language of the sites also was evaluated and all present Portuguese only language. The general result demonstrated in grafico and tables with classification of the Universities...

Analysis of techniques for mapping environments for fauna survey

Thackway, Richard Malcom
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Thesis (Masters)
EN
Relevância na Pesquisa
55.48%
A discussion of environmental land classification is presented for the purpose of surveying avifaunal communities. Surveying and mapping land uses the term environment in a special sense. Environment can be mapped into regions whose components are interacting climate terrain, geology, soils and biota. The problem of how to describe the environment for sampling fauna requires an approach which samples the inherent and known variability of all environmental regions present. Discovery of patterns between fauna and environment provide the basis for understanding species/habitat relationships and provides a valuable basis for management or more detailed studies. Two environmental mapping methods commonly employed in faunal survey and management are systematic grids and natural landscape patterns; these were compared to determine their effectiveness for classifying the environment for sampling avifaunal communities. A detailed study was undertaken between 1982-84 in a plot of 8km2 in the Tianjara area. The plot was chosen to encompass a representative sample of the wide range of environments described by Gunn (1985). Analysis of the systematic grids involved sampling a diverse set of environmental attributes into six different grid sizes...

Fractal analysis of cancellous bone in disease

Parkinson, Ian Henry
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado Formato: 904393 bytes; 832922 bytes; 1290063 bytes; 3555072 bytes; 212300 bytes; application/pdf; application/pdf; application/pdf; application/pdf; application/pdf
Publicado em //2002 EN
Relevância na Pesquisa
55.52%
The principal aim of this thesis was to develop and implement a standardised protocol for the fractal analysis of cancellous bone architecture. Cancellous bone structure from different skeletal sites in groups of osteoporotic, osteoarthritic and normal individuals was analysed. The results of fractal analysis were explained in the context of conventional bone histomorphometry and a priori knowledge to advance the understanding of cancellous bone architecture. There has been much effort devoted to the pursuit of descriptors of cancellous bone complexity. The aim of these endeavours has been to develop morphological descriptors of bone quality that explain the functional properties of the cancellous bone structure for age-related changes, the effect of disease processes or the effect of therapeutic agents on the diseased skeleton. The fractal analysis of the complexity of cancellous bone architecture promises to be an exciting addition to existing analytical techniques. The establishment of a standardised methodology for the fractal analysis of cancellous bone encompassed many components. Knowledge of the stereological and histomorphometric principles that are employed in currently available techniques enabled a comprehensive examination of the factors that effect the measurement of the fractal dimensions. The methodology presented in this thesis has been optimised specifically for measuring sectional fractal dimensions in histological sections of cancellous bone. The sectional fractal dimensions show that...

Functional analysis of middle temporal visual area and its associated behavior

Zhao, Ruilin, 1972-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 120 leaves; 9124776 bytes; 9124529 bytes; application/pdf; application/pdf
ENG
Relevância na Pesquisa
75.41%
Our lab's long-term goal is to elucidate the circuitry of the visual cortex, to develop quantitative computational models of neuronal function in the visual cortex, and to establish how these models may relate to visual perception and visually guided behavior. Central to this goal is the analysis of functional architecture, which is crucial to an understanding of how the brain works. In my thesis research, I applied behavioral and microstimulation techniques to demonstrate the causal connections between neural activity and behavior. Understanding these relationships is one of the fundamental issues needed to be addressed in Neurobiology. Specifically, I focused on the functional analysis of the middle temporal visual area (MT) and the behavior associated with it. MT is an extrastriate area that is primarily involved in visual motion processing. A very important function within MT is a segregation of center-surround interactions which plays a critical role in processing visual motion cues. There are two types of motion center-surround interactions in MT neurons: surrounds may reinforce (at wide-field sites) or suppress (at local-motion sites) the centers' directional responses. They are important in representing the initial stages of a functional segregation between wide-field and local-contrast motion processing. To further study the computational model used by the brain to readout sensory information...

Mechanistic studies of bleomycin-mediated double-stranded DNA cleavage and structural studies of DNA containing normal and 4'-oxidized abasic sites; Structural studies of DNA containing normal and 4'-oxidized abasic sites

Chen, Jingyang, Ph. D. Massachusetts Institute of Technology
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 288 leaves
ENG
Relevância na Pesquisa
65.35%
In order to examine the role of partial intercalation in double-stranded (ds) DNA cleavage mediated by a single bleomycin (BLM), a bulky group ([-cyclodextrin) was chemically attached to the polyamine tail of BLM A5 to prevent the intercalation of the bithiazole tail. The ability of this analog (CD-BLM) to effect ds-DNA cleavage was quantitatively analyzed using the internally [132P-labeled hairpin DNA technology and the supercoilded DNA relaxation assay. CD-BLM can mediate both ss and ds-DNA cleavage, although 5-fold less efficient than BLM A5. Analysis of DNA cleavage by CD-BLM with competitive BLM-Co(III)-OOH indicates that the ds-DNA cleavage is mediated by two CD-BLM molecules, suggesting that the partial intercalation is essential for one BLM molecule to mediate ds-DNA cleavage. A "hot spot" for blunt-ended ds-cleavage by BLM (5'-GTCA-3'/3'-CAGT-5') has been identified in an effort to obtain structural insights into the mechanism of the blunt-ended ds-DNA cleavage. A 3'-phosphoglycolate/5'-phosphate (3'PG/5'P) gapped lesion in this "hot spot" has been synthesized to probe the structural basis for re-organization of BLM to the second cleavage site. This lesion was titrated with BLM-Co(III)-OOH. The resulting mixture of complexes was in fast exchange on the NMR time scale...

An analysis of enhanced traffic management system data using three dimensional MATLAB visualizations

Tindell, Evan
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 28 leaves
ENG
Relevância na Pesquisa
65.24%
In this thesis I use MATLAB visualizations to analyze right patterns over major airports. I will analyze capacity constraints on some of the nation's most congested airports, and define flight paths that converge on them using these MATLAB visualizations. I will also analyze the air traffic patterns over a specific number of sites around the United States where a change in plane surveillance technology is scheduled to occur.; by Evan Tindell.; Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.; Includes bibliographical references (leaf 28).

An Analysis of Public Garden Websites

Tejral, Cindy
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado Formato: Note: Except for the faculty signature page, which was not digitized, the entire thesis was scanned as formatted by the author.
EN_US
Relevância na Pesquisa
55.47%
Over 38 Million Web sites are now available for on-line viewing. Public gardens are a small portion of this astonishing number and are increasingly using the Internet as a means to inform the public of their presence, including their mission, collections, and programs. Likewise, the information provided on a public garden’s Web site may educate, entertain, and encourage the user to become involved with the garden through visiting or donating their time or money. The purpose of this research was to analyze and describe the current use of Web sites by public gardens in the United States. Surveys to admissions-charging public gardens with Web sites offered insights into the garden’s Web site creation and maintenance processes and content decisions. The development, maintenance, content, and methods of analysis of individual public garden Web sites show trends in the following areas: development costs and time, maintenance frequency and associated costs, types of staff used for site content development, design, and maintenance, methods of enriching a site’s content through links, plug-ins, and interactive features, and the methods used to determine a Web site’s usability. Results indicate that the majority of institutions have had Web sites for over 2 years...

Análise dos sites das bibliotecas universitárias do estado de Santa Catarina: funções e usabilidade Analysis of the sites Santa Catarina's academical libraries state: functions and use p. 76-106

Prado, Noêmia Schoffen; Peruzzo, Tarcila; Ohira, Maria Lourdes Blatt
Fonte: Associação Catarinense de Bibliotecários Publicador: Associação Catarinense de Bibliotecários
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Investigação avaliativa; Descritiva; Quantitativa; Observação Formato: application/pdf
Publicado em 27/10/2005 POR
Relevância na Pesquisa
85.5%
Analisa sites das bibliotecas Universitárias do Estado de Santa Catarina. Verifica aspectos da estrutura da informação disponibilizada, das suas funções e da sua usabilidade, a partir de critérios presentes na literatura nacional e estrangeira. São avaliados 20 sites, observando-se que prevalece a função referencial com 60% de itens positivos, seguida da função pesquisa com 59,17%. Na usabilidade observa-se que o módulo links e o módulo informações de identificação são os mais apresentados pelos sites, com 75,02% e 62,50%, respectivamente, suprindo assim as necessidades dos juízes. Abstract: Analysis of sites the Academical Libraries from the State of Santa Catarina verifying aspects of the structure of the made available information, of their functions and of his use, starting from present criteria in the national and foreign literature. A total of 20 web sites, being observed that the function referencial prevails with 60% of positive items, following by the function with 59,17%. The use , It was observed that the links module and the identification information module are the more presented by the sites, with 75,02% and 62,50%, respectively, supplying in this manner the judges' needs.