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A closer look at multiple-clone Plasmodium vivax infections: detection methods, prevalence and consequences

HAVRYLIUK, Tatiana; FERREIRA, Marcelo U
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.38%
The naturally occurring clonal diversity among field isolates of the major human malaria parasite Plasmodium vivax remained unexplored until the early 1990s, when improved molecular methods allowed the use of blood samples obtained directly from patients, without prior in vitro culture, for genotyping purposes. Here we briefly review the molecular strategies currently used to detect genetically distinct clones in patient-derived P. vivax samples, present evidence that multiple-clone P. vivax infections are commonly detected in areas with different levels of malaria transmission and discuss possible evolutionary and epidemiological consequences of the competition between genetically distinct clones in natural human infections. We suggest that, when two or more genetically distinct clones are present in the same host, intra-host competition for limited resources may select for P. vivax traits that represent major public health challenges, such as increased virulence, increased transmissibility and antimalarial drug resistance.; CNPq; Mount Sinai School of Medicine

Plasmodium vivax: Microsatellite analysis of multiple-clone infections

HAVRYLIUK, Tatiana; ORJUELA-SANCHEZ, Pamela; FERREIRA, Marcelo U.
Fonte: ACADEMIC PRESS INC ELSEVIER SCIENCE Publicador: ACADEMIC PRESS INC ELSEVIER SCIENCE
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.61%
We used mixtures of genomic DNA from two genetically distinct isolates from Brazil, 42M and 312M, to investigate how accurately 12-locus microsatellite typing describes the overall genetic diversity and characterizes multilocus haplotypes in multiple-clone Plasmodium vivax infections. We found varying PCR amplification efficiencies of microsatellite alleles; for example, from the same 1:1 mixture of 42M and 312M DNA we amplified predominantly 312M-type alleles at 10 loci and 42M-type alleles at 2 loci. All microsatellite alleles were accurately scored in 1:0.5 and 1:0.25 312M:42M DNA mixtures, even when minor peak heights did not meet previously suggested criteria for minor allele detection in multiple-clone infections. Relative proportions of major and minor alleles were unaffected by multiple displacement amplification of template DNA prior to PCR-based microsatellite typing. Although microsatellite typing may detect minor alleles in clone mixtures, amplification biases may lead to inaccurate assignment of predominant haplotypes in multiple-clone P. vivax infections. (C) 2008 Elsevier Inc. All rights reserved.; Fundacao de Apoio a Pesquisa do Estado de Sao Paulo (FAPESP)[07/51199-0]; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)[470570/2006-7]

A infecção murina pelo clone Sylvio X10/4 de Trypanosoma cruzi: um modelo para estudo da patogenia da doença de Chagas crônica.; The murine infection with the Sylvio X10/4 clone of Trypanosoma cruzi: a model to study the phatogenesis of chronic Chagas' disease.

Marinho, Claudio Romero Farias
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 12/12/2003 PT
Relevância na Pesquisa
36.61%
Este trabalho descreve um novo modelo murino para o estudo da infecção crônica pelo T. cruzi usando o clone Sylvio X10/4. A infecção crônica de camundongos C3H/HePAS é caracterizada por intensas lesões inflamatórias no coração que podem ser comparáveis às observadas na doença de Chagas humana. Lesões moderadas também estavam presente na musculatura estriada esquelética desses animais. No coração dos animais crônicos foram detectados parasitas viáveis, confirmando a hipótese de que o desenvolvimento da patologia cardíaca na doença de Chagas está diretamente relacionada com a persistência do T. cruzi no tecido inflamado. Em contraste, camundongos A/J cronicamente infectados desenvolvem lesões no fígado e no músculo estriado, enquanto que no coração, não foram observados lesões nem parasitas. A análise fenotípica das gerações F1 e F2 (A/J X C3H/HePAS) sugere que a predisposição genética para desenvolver lesões teciduais na infecção pelo T. cruzi é heterogênea uma vez que a patologia no coração e no fígado é segregada na geração F2. Nossos resultados corroboram a hipótese que a heterogeneidade na patologia observada em pacientes com a doença de Chagas (ausência ou presença de lesões cardíacas ou digestivas) pode ser atribuída a fatores genéticos.; This work describes a novel murine model of the chronic infection by T. cruzi using the clone Sylvio X10/4. The infection in the C3H/HePAS mouse strain is characterized by intense inflammatory lesions in the heart...

Potencial Citogenotóxico da Rodamina B em Tradescantia (clone BNL 4430)

OLIVEIRA, Letícia Baltar Pinto de
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: Trabalho de Conclusão de Curso Formato: 17 f.
PT_BR
Relevância na Pesquisa
36.56%
Projeto acadêmico (graduação) - Universidade Federal de Santa Catarina. Campus Curitibanos. Ciências Rurais.; O Estado de Santa Catarina apresenta um polo industrial diversificado com a presença de atividades têxteis, papel e celulose, agroindustrial e madeireira. Estas indústrias geram efluentes que podem prejudicar ambientalmente as áreas em seu entorno, a exemplo dos resíduos de uso de compostos xantenos para tingimento, como a Rodamina B. Desta forma, poderia este corante causar efeitos mutagênicos e/ou citogenotóxicos para plantas? Para a avaliação de potencialidade tóxica de poluentes são utilizados bioensaios com plantas superiores, uma vez que são eficazes na detecção de substâncias tóxicas por serem extremamente sensíveis e de baixo custo. O efeito tóxico da Rodamina B em células vegetais, pode ser investigado através de testes de citogenotoxicidade em Tradescantia (clone BNL 4430), uma espécie modelo comumente empregada em estudos de biomonitoramento. O objetivo deste trabalho será a avaliação do efeito citogenotóxico do corante Rodamina B em células de planta modelo Tradescantia clone BNL 4430, através da aplicação de testes citogenéticos, como o bioensaio do pêlo estaminal (TRAD-TSH) e o teste de micronúcleo (TRAD-MCN). Para isto...

A two-plasmid strategy for engineering a dengue virus type 3 infectious clone from primary Brazilian isolate

SANTOS,JEFFERSON J.S.; CORDEIRO,MARLI T.; BERTANI,GIOVANI R.; MARQUES,ERNESTO T.A.; GIL,LAURA H.V.G.
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 EN
Relevância na Pesquisa
36.49%
Dengue infections represent one of the most prevalent arthropod-borne diseases worldwide, causing a wide spectrum of clinical outcomes. Engineered infectious clone is an important tool to study Dengue virus (DENV) biology. Functional full-length cDNA clones have been constructed for many positive-strand RNA viruses and have provided valuable tools for studying the molecular mechanisms involved in viral genome replication, virion assembly, virus pathogenesis and vaccine development. We report herein the successful development of an infectious clone from a primary Brazilian isolate of dengue virus 3 (DENV3) of the genotype III. Using a two-plasmid strategy, DENV3 genome was divided in two parts and cloned separately into a yeast-bacteria shuttle vector. All plasmids were assembled in yeast by homologous recombination technique and a full-length template for transcription was obtained by in vitro ligation of the two parts of the genome. Transcript-derived DENV3 is infectious upon transfection into BHK-21 cells and in vitro characterization confirmed its identity. Growth kinetics of transcript-derived DENV3 was indistinguishable from wild type DENV3. This system is a powerful tool that will help shed light on molecular features of DENV biology...

Cryptic infections in mice with the Trypanosoma cruzi CL-14 clone

SOUSA,M.A.; PEREIRA,S.M.S.
Fonte: Instituto de Medicina Tropical Publicador: Instituto de Medicina Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/1999 EN
Relevância na Pesquisa
36.49%
A infectividade do clone CL-14 do Trypanosoma cruzi para camundongos foi revista utilizando-se como inóculo metacíclicos de cultura em NNN+LIT, pré-incubados ou não com complemento de cobaio. Nos animais inoculados não observamos parasitemia patente, mas a presença do parasito foi confirmada em 30% deles (9/30) através de hemocultivo ou xenodiagnóstico, este examinado aos 100 dias. A positividade das hemoculturas pôde ser evidenciada a partir dos 60 dias quando procederam de camundongos inoculados com metacíclicos tratados com complemento. Nos demais hemocultivos a positividade foi constatada aos 100 dias ou posteriormente. Um reisolado do CL-14 também não determinou parasitemia patente em camundongos até 30 dias após a inoculação. Estes achados são discutidos em relação à proteção imunológica observada em camundongos inoculados com este clone.

Biological characterization of a beta-galactosidase expressing clone of Trypanosoma cruzi CL strain

Le-Senne,Ana; Muelas-Serrano,Susana; Fernández-Portillo,Carlos; Escario,José Antonio; Gómez-Barrio,Alicia
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2002 EN
Relevância na Pesquisa
36.49%
Clone CL B5 of Trypanosoma cruzi is a beta-galactosidase expressing organism that was genetically transfected to be used for in vitro pharmacological screening. Biological parameters were determined, evaluating growth kinetics of epimastigotes, metacyclogenesis, infectivity to mammalian cell lines, parasitemia kinetics in mice and sensibility to nifurtimox and benznidazole. Differences in relation to other strains and CL parental strain were found, the most important being the incapability to produce death to mice in spite of the high inoculum used. However, it possesses the required features to be used for in vitro drug screening. Data obtained demonstrate that heterogeneity of T. cruzi appears even among clones of the same strain, and that these differences found do not prevent the use of clone CL B5 for the purpose that was engineered.

Estudo anatômico foliar do clone híbrido 4430 de Tradescantia: alterações decorrentes da poluição aérea urbana

ALVES,EDENISE SEGALA; GIUSTI,PAULA MATTOS; DOMINGOS,MARISA; SALDIVA,PAULO H.N.; GUIMARÃES,ELIANE T.; LOBO,DÉBORA J.A.
Fonte: Sociedade Botânica de São Paulo Publicador: Sociedade Botânica de São Paulo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2001 PT
Relevância na Pesquisa
36.61%
Estudos epidemiológicos mostram uma relação entre a poluição aérea em centros urbanos e a taxa de doenças respiratórias na sua população. Em São Paulo, a concentração dos principais poluentes aéreos é monitorada pela CETESB porém, tais dados não dão idéia do risco ao qual a população está sujeita; plantas bioindicadoras podem dar idéia deste risco. O clone híbrido 4430 de Tradescantia vem sendo utilizado em bioensaios (Trad-MCN, Trad-SH) que avaliam o efeito genotóxico de várias substâncias. Não há registros das potencialidades de bioindicação relativas à estrutura das folhas do clone. Este estudo objetivou estabelecer o padrão estrutural da folha do clone e verificar se existem características anatômicas afetadas pela poluição, que podem ser utilizadas como bioindicadoras. Para tanto, plantas do clone 4430 procedentes da EMBRAPA-Jaguariúna-SP (fora da influência da poluição da cidade de São Paulo -- material controle) foram cultivadas em condições padronizadas e expostas em três pontos distintos da cidade: Instituto de Botânica, Cerqueira César e Congonhas onde permaneceram por três meses. A análise da estrutura da folha mostrou que a mesma apresenta: epiderme uniestratificada com tricomas tectores e glândulares nas duas superfícies...

Characterization of the Brazilian endemic clone of methicillin-resistant Staphylococcus aureus (MRSA) from hospitals throughout Brazil

Oliveira,Geraldo A.; Faria,Juarez B.; Levyand,Carlos E.; Mamizuka,Elsa M.
Fonte: Brazilian Society of Infectious Diseases Publicador: Brazilian Society of Infectious Diseases
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2001 EN
Relevância na Pesquisa
36.56%
The objective of this study was to characterize patterns of the Brazilian endemic clone of methicillin-resistant Staphylococcus aureus (MRSA) from hospitals throughout Brazil. We studied 83 MRSA strains isolated from patients hospitalized in 27 public and private hospitals in 19 cities located in 14 Brazilian states from September, 1995, to June, 1997. The MRSA strains were typed using antibiograms, bacteriophage typing and pulsed field gel electrophoresis (PFGE). The analysis of genomic DNA by PFGE showed that 65 isolates presented the same PFGE pattern. This pattern was present in all of the hospitals studied indicating the presence of an endemic MRSA clone widely disseminated throughout Brazilian hospitals (BEC). All isolates belonging to the BEC proved to be resistant to ciprofloxacin, erythromycin, lincomycin, trimethoprim-sulphamethoxazole, and tetracycline. Variable susceptibility to these drugs was found only in isolates belonging to clones other than the BEC. The results show that, among MRSA, the BEC is common in Brazil. The best method for mapping changes in the frequency of this clone among MRSA is pulsed field gel electrophoresis. Use of molecular mapping is an important tool for monitoring the spread of potentially dangerous microbes.

A Mutation Analysis Based Model Clone Detector Evaluation Framework

Stephan, MATTHEW
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
36.77%
Model-Driven Engineering is becoming increasingly prevalent and mature. As software projects developed through this methodology age, the need for analysis of Model-Driven projects becomes imperative. One form of analysis is Model Clone Detection, which involves finding similar or identical model fragments in a given context. There are a number of techniques intended for Model Clone Detection and for different types of models. One hindrance to the growth of this field is the ability to objectively and quantitatively compare different model clone detectors and settings of the same detector. In this thesis, our original contribution to knowledge includes a framework utilizing Mutation Analysis to evaluate and compare model clone detectors. It is our proposition that, through distinguishing edit operations on models as mutations, we can create such a framework. In order to demonstrate the plausibility of our framework, we develop a Simulink implementation of the framework. We begin by outlining our initial, qualitative, attempts evaluating our Simulink model clone detector. This includes challenges encountered that are addressed by our framework. We outline the framework and describe each step in its process in an example-driven manner through creation of a framework prototype that works on Simulink model clone detectors. We choose Simulink because it is the most mature form of Model Clone Detection...

AN EMPIRICAL STUDY FOR THE IMPACT OF MAINTENANCE ACTIVITIES IN CLONE EVOLUTION

MARKS, LIONEL
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado Formato: 1055138 bytes; application/pdf
EN; EN
Relevância na Pesquisa
36.65%
Code clones are duplicated code fragments that are copied to re-use functionality and speed up development. However, due to the duplicate nature of code clones, inconsistent updates can lead to bugs in the software system. Existing research investigates the inconsistent updates through analysis of the updates to code clones and the bug fixes used to fix the inconsistent updates. We extend the work by investigating other factors that affect clone evolution, such as the number of developers. On two levels of analysis, the method and clone class level, we conduct an empirical study on clone evolution. We analyze the factors affecting bug fixes and co-change (i.e. update cloned methods at the same time) using our new metrics. Our metrics are related to the developers, code complexity, and stages of development. We use these metrics to find ways to improve the maintenance of cloned code. We discover that one way to improve maintenance of code clones is the decrease of code complexity. We find that increased code complexity leads to a decrease in co-change, which can lead to bugs in the software. We perform our study on 6 applications. To maximize the number of clones detected, we use two existing code clone detection tools: SimScan and Simian. SimScan was used to find clones in 5 of the applications due to its versatility in finding code clones. Simian was used to detect clones due to its reliability to find code clones regardless of language or compilation problems. To analyze and determine the significance of the metrics...

Empirical Studies of Code Clone Genealogies

BARBOUR, LILIANE JEANNE
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
36.84%
Two identical or similar code fragments form a clone pair. Previous studies have identified cloning as a risky practice. Therefore, a developer needs to be aware of any clone pairs so as to properly propagate any changes between clones. A clone pair experiences many changes during the creation and maintenance of software systems. A change can either maintain or remove the similarity between clones in a clone pair. If a change maintains the similarity between clones, the clone pair is left in a consistent state. However, if a change makes the clones no longer similar, the clone pair is left in an inconsistent state. The set of states and changes experienced by clone pairs over time form an evolution history known as a clone genealogy. In this thesis, we provide a formal definition of clone genealogies, and perform two case studies to examine clone genealogies. In the first study, we examine clone genealogies to identify fault-prone “patterns” of states and changes. We also build prediction models using clone metrics from one snapshot and compare them to models that include historical evolutionary information about code clones. We examine three long-lived software systems and identify clones using Simian and CCFinder clone detection tools. The results show that there is a relationship between the size of the clone and the time interval between changes and fault-proneness of a clone pair. Additionally...

NeCO: Ontology Alignment using Near-miss Clone Detection

Geesaman, Paul Louis
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
36.49%
The Semantic Web is an endeavour to enhance the web with the ability to represent knowledge. The knowledge is expressed through what are called ontologies. In order to make ontologies useful, it is important to be able to match the knowledge represented in different ontologies. This task is commonly known as ontology alignment. Ontology alignment has been studied, but it remains an open problem with an annual competition dedicated to measure alignment tools' performance. Many alignment tools are computationally heavy, require training, or are useful in a specific field of study. We propose an ontology alignment method, NeCO, that builds on clone detection techniques to align ontologies. NeCO inherits the clone detection features, and it is light-weight, does not require training, and is useful for any ontology.; Thesis (Master, Computing) -- Queen's University, 2014-01-29 14:38:52.873

An Approach to Clone Detection in Behavioral Models

ANTONY, ELIZABETH
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
36.56%
In this thesis, we present an approach for identifying near-miss interaction clones in reverse-engineered UML behavioural models. Our goal is to identify patterns of interaction ("conversations") that can be used to characterize and abstract the run-time behaviour of web applications and other interactive systems. In order to leverage robust near-miss code clone technology, our approach is text-based, working on the level of XMI, the standard interchange serialization for UML. Behavioural model clone detection presents several challenges - first, it is not clear how to break a continuous stream of interaction between lifelines (lifelines represent the objects or actors in the system) into meaningful conversational units. Second, unlike programming languages, the XMI text representation for UML is highly non-local, using attributes to reference information in the model file remotely. In this work we use a set of contextualizing source transformations on the XMI text representation to reveal the hidden hierarchical structure of the model and granularize behavioural interactions into conversational units. Then we adapt NiCad, a near-miss code clone detection tool, to help us identify conversational clones in reverse-engineered behavioural models. These conversational clones are then analysed to find worrisome patterns of security access violations.; Thesis (Master...

LEVERAGING HISTORICAL CODE CHANGES TO SUPPORT CLONE MANAGEMENT ACTIVITIES

Sourav, SUMIT
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
36.84%
Code clones are code snippets that come into existence when developers copy paste (and possibly modify) an existing piece of code. Studies show that cloning is an inevitable phenomenon leading to a significant presence of code clones (as much as 10%-30% of the source code consists of cloned code) in large software systems. To effectively manage these clones, researchers have proposed multiple activities along two dimensions: 1) proactive clone management, and 2) post-mortem clone management. Proactive clone management emphasis is on activities that prevent the introduction of new clones into the source code (e.g., identifying the factors that influence developers to clone code). On the other hand, post-mortem clone management focuses on managing the existing clones (e.g., detection or refactoring of a clone). In this thesis, we examine several open issues along both dimensions of clone management activities. For example, over 80% of research focuses on the detection of clones and studying their impact on code quality. However, limited research has examined the factors that make code more likely to be cloned. We find that an increase in the complexity of a method increases the likelihood of code being cloned from that method. Moreover...

EMPIRICAL STUDIES OF CLONE MUTATION AND CLONE MIGRATION IN CLONE GENEALOGIES

Xie, Shuai Jr
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
36.87%
Duplications and changes made on code segments by developers form code clones. Cloned code segments are exactly the same or have a particular similarity. A set of cloned code segments that have the same similarity with each other become a clone group. A clone genealogy contains several clone groups in different revisions and time periods. Based on different textual similarities, there are three clone types, i.e., Type-1, Type-2, and Type-3. Clone mutation contains the changes of clone types in the clone evolutions. Clone migration is known as moving cloned code segment to another location in the software system. In this thesis, we build clone genealogies by clone groups in two empirical studies. We conduct two studies on clone migration and clone mutation in clone genealogies. We use three large open source software systems in both studies. In the first study, we investigate if the fault-proneness of clone genealogies is affected by different patterns of clone mutation and different evolution patterns of distances among clones in clone groups. We conclude that clone groups mutated between Type-1 and Type-2 and between Type-1 and Type-3 clones have higher risk for faults. We find that modifying the location of a clone increases its risk for faults. In the second study...

DETECTING PDF JAVASCRIPT MALWARE USING CLONE DETECTION

Karademir, SARUHAN
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
36.56%
One common vector of malware is JavaScript in Adobe Acrobat (PDF) files. In this thesis, we investigate using near-miss clone detectors to find this malware. We start by collecting a set of PDF files containing JavaScript malware and a set with clean JavaScript from the VirusTotal repository. We use the NiCad clone detector to find the classes of clones in a small subset of the malicious PDF files. We evaluate how clone classes can be used to find similar malicious files in the rest of the malicious collection while avoiding files in the benign collection. Our results show that a 10% subset training set produced 75% detection of previously known malware with 0% false positives. We also used the NiCad as a pattern matcher for reflexive calls common in JavaScript malware. Our results show a 57% detection of malicious collection with no false positives. When the two experiments’ results are combined, the total coverage of malware rises to 85% and maintains 100% precision. The results are heavily affected by the third-party PDF to JavaScript extractor used. When only successfully extracted PDFs are considered, recall increases to 99% and precision remains at 100%.; Thesis (Master, Electrical & Computer Engineering) -- Queen's University...

Qualidade da madeira em clone de Eucalyptus grandis W. Hill ex Maiden submetido a desrama artificial

Polli,Henrique Quero; Reis,Geraldo Gonçalves dos; Reis,Maria das Graças Ferreira; Vital,Benedito Rocha; Pezzopane,José Eduardo Macedo; Fontan,Ivan da Costa Ilhéu
Fonte: Sociedade de Investigações Florestais Publicador: Sociedade de Investigações Florestais
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2006 PT
Relevância na Pesquisa
36.49%
A qualidade da madeira para serraria foi avaliada em plantas de clone de Eucalyptus grandis, submetidas à desrama artificial, utilizando-se a combinação de diferentes alturas de remoção dos galhos, a partir do solo, e de intervenções necessárias para atingir 6 m de altura livre de galhos, em Abaeté, MG (19º15'94" S e 45º44'56" W). A primeira intervenção de desrama ocorreu quando as plantas apresentavam 16 meses de idade. A conicidade, o achatamento e o encurvamento da primeira tora não diferiram significativamente entre os tratamentos. A desrama artificial, no entanto, promoveu redução no núcleo nodoso, com um ganho médio de 94% na extensão de madeira limpa em relação à testemunha. Para ferimentos de desrama de diâmetro inferior a 1,5 cm, a extensão de oclusão do galho foi de 0,48 cm, com 42% dos ferimentos apresentando fenda aberta. Para ferimentos com diâmetro superior a 1,5 cm, a extensão da oclusão foi de 0,74 cm, com 92% dos ferimentos com fenda aberta, indicando cicatrização mais rápida em ferimentos de remoção de galhos de menor diâmetro. O ângulo de inclinação do galho foi mais próximo à horizontal, principalmente entre 0 e 1,5 m de altura do tronco. A densidade da madeira ao longo do tronco não foi afetada pela desrama artificial...

Evidence for a human-specific Escherichia coli clone

Clermont, Olivier; Lescat, Mathilde; O'Brien, Claire; Gordon, David; Tenaillon, Olivier; Denamur, Erick
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.56%
Escherichia coli is a widespread commensal of the vertebrate intestinal tract. Until recently, no strong association between a particular clone and a given host species has been found. However, members of the B2 subgroup VIII clone with an O81 serotype ap

Comprehensive clone screening and evaluation of fed-batch strategies in a microbioreactor and lab scale stirred tank bioreactor system : application on Pichia pastoris producing Rhizopus oryzae lipase

Hemmerich, Johannes; Adelantado Vallve, Nuria; Barrigón de San Marcos, José; Ponte, Xavier; Hörmann, Astrid; Ferrer Alegre, Pau; Kensy, Frank; Valero Barranco, Francisco
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2014 ENG
Relevância na Pesquisa
36.71%
Background: In Pichia pastoris bioprocess engineering, classic approaches for clone selection and bioprocess optimization at small/micro scale using the promoter of the alcohol oxidase 1 gene (PAOX1), induced by methanol, present low reproducibility leading to high time and resource consumption. - Results: An automated microfermentation platform (RoboLector) was successfully tested to overcome the chronic problems of clone selection and optimization of fed-batch strategies. Different clones from Mut+P. pastoris phenotype strains expressing heterologous Rhizopus oryzae lipase (ROL), including a subset also overexpressing the transcription factor HAC1, were tested to select the most promising clones. The RoboLector showed high performance for the selection and optimization of cultivation media with minimal cost and time. Syn6 medium was better than conventional YNB medium in terms of production of heterologous protein. The RoboLector microbioreactor was also tested for different fed-batch strategies with three clones producing different lipase levels. Two mixed substrates fed-batch strategies were evaluated. The first strategy was the enzymatic release of glucose from a soluble glucose polymer by a glucosidase, and methanol addition every 24 hours. The second strategy used glycerol as co-substrate jointly with methanol at two different feeding rates. The implementation of these simple fed-batch strategies increased the levels of lipolytic activity 80-fold compared to classical batch strategies used in clone selection. Thus...