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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Etude des relations entre arthropodes et bactéries : épidémiologie moléculaire et modèles expérimentaux / Study of the relationship between arthropods and bacteria : molecular epidemiology and experimental models

Leulmi, Hamza 28 September 2015 (has links)
Ce travail s’articule sur trois axes ; le premier est une contribution à l'étude du répertoire des bactéries associées aux arthropodes vecteurs (tique et puces) en Afrique du nord (Algérie) et en Afrique Sub-saharienne (Bénin, Tanzanie et République Démocratique du Congo). Nous avons pu ainsi détecter par biologie moléculaire (qPCRs, PCR standard et séquençage) et pour la première fois au Bénin, Rickettsia typhi (l'agent du typhus murin), et Bartonella sp dans des puces collectées sur des rongeurs à Cotonou. Dans ce travail, nous avons également détecté Yersinia pestis, l'agent de la peste et R. felis (responsable de la fièvre boutonneuse) dans des puces de la RD du Congo. En Tanzanie, nous avons mis en évidence la présence de R. felis et R. typhi dans des puces de rongeurs. En Algérie, nous avons décrit pour la première fois la présence d'agent de borréliose de Lyme (Borrelia garinii) dans les tiques. Nous avons confirmé la présence de R. massiliae, R. monacensis R. aeschlimannii, R. slovaca et R. felis et nous avons également détecté pour la première fois en Algérie, Bartonella tamiae, une bactérie dont la pathogénicité est peu connue et Coxiella burnetii, l'agent de la fièvre Q.Dans la deuxième partie de notre travail, nous nous sommes intéressés à l’évaluation des compétences vectorielles des puces de chat (Ctenocephalides felis) et punaises de lit (Cimex lectularius) dans la transmission de l’agent de la fièvre des tranchées (Bartonella quintana) dont le vecteur connu est le pou de corps. Trois approches ont été utilisées : la qPCR, la culture et l’immunohistochimie. / This work focuses on three areas; the first is a contribution to the study of the repertoire of bacteria associated with arthropod vectors (tick and flea) in North Africa (Algeria) and in Sub-Saharan Africa (Benin, Tanzania and the Democratic Republic of Congo). We could thus detected by molecular tools (qPCRs, standard PCR and sequencing) and for the first time in Benin, Rickettsia typhi (the agent of murine typhus) and Bartonella sp in fleas collected from rodents in Cotonou. In this work, we have also associated the agent of plague (Yersinia pestis), and for the first time in fleas of DR of Congo, and we detected also R. felis (the causative agent of spotted fever). In Tanzania, we have highlighted the presence of R. typhi and R. felis fleas on rodents. In Algeria, we described for the first time the presence of Lyme disease agent (Borrelia garinii) in hard ticks. We confirmed the presence of R. massiliae, R. monacensis, R. aeschlimannii, R. slovaca and R. felis, we also detected for the first time Bartonella tamiae and Coxiella burnetii associated with bat ticks in Algeria.Regarding the second part we was interested in the evaluation of vector competence of cat fleas (Ctenocephalides felis) and bed bugs (Cimex lectularius) in the transmission of trench fever agent (Bartonella quintana) that is known to be transmitted by lice. Three approaches have been tested; qPCR, culture and immunohistochemistry.
62

Ecologia química de percevejos da família Phloeidae e oxirredutases de Bacillus safensis isolado do petróleo / Phloeidae stink bugs chemical ecology and Bacillus safensis oxidoreductases from petroleum

Fonseca, Francine Souza Alves da, 1979- 03 December 2013 (has links)
Orientador: Anita Jocelyne Marsaioli / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T10:44:31Z (GMT). No. of bitstreams: 1 Fonseca_FrancineSouzaAlvesda_D.pdf: 8642062 bytes, checksum: fa3ebef40c6304d2e6d2b02ba701f86e (MD5) Previous issue date: 2013 / Resumo: Capítulo I. Este trabalho revelou aspectos inéditos da ecologia química de Phloeophana longirostris e Phloea subquadrata, duas espécies de percevejo da família Phloeidae. Esta família, representada por apenas três gêneros e quatro espécies, é caracterizada por apresentar cuidado maternal com ovos e ninfas e camuflagem sobre o tronco das árvores hospedeiras. O objetivo deste trabalho foi localizar, identificar e caracterizar os principais compostos voláteis emitidos por percevejos e verificar a relação destes com as árvores hospedeiras. Os resultados revelaram que os insetos, após estímulo físico, liberam aldeídos e hidrocarbonetos insaturados, oxoaldeídos e ésteres como compostos majoritários. Além disso, foi possível discriminar compostos característicos de cada grupo estudado. Capítulo II. Na segunda parte deste trabalho, foi explorada a atividade enzimática do micro-organismo Bacillus safensis isolado do petróleo brasileiro. Esse micro-organismo apresenta um arsenal enzimático capaz de degradar compostos orgânicos aromáticos. O objetivo deste trabalho foi purificar, isolar e identificar oxirredutases presentes na cepa (CFA06) de Bacillus safensis. Através dessa bactéria Gram-positiva, altamente resistente à radiação ultravioleta, foi possível identificar duas oxirredutases, sendo uma delas inédita. A oxirredutase inédita, aqui denominada de BsP315, apresenta 21 kDa e ferro e molibdênio ligados a essa proteína. Além dessa oxirredutase, uma catalase, aqui denominada de BsCat, também foi identificada / Abstract: Chapter I. This study revealed novel aspects of the chemical ecology of Phloeophana longirostris and Phloea subquadrata from Phloeidae family. This family, has only three genders and four species with characteristic maternal care of eggs and nymphs and camouflage on the trunk of the host tree. The aim of this study was to the identification of major volatile compounds produced by the stink bugs and their relationship with the host trees. The results revealed that after physical stimulation, the insects release aldehydes and unsaturated hydrocarbons, esters and oxoaldehyde as major compounds. These volatile compounds were important in the discrimination of male, female and nymphs of each species. Chapter II. In the second part of this research, we investigated the enzymatic activity of the micro-organism Bacillus safensis isolated from Brazilian oil. This micro-organism has an enzymatic arsenal capable of degrading aromatic organic compounds. The aim of this study was to purify, isolate and identify oxidoreductases present in strain (CFA06) Bacillus safensis. Through this Gram-positive bacterium, highly resistant to ultraviolet radiation, it was possible to identify two oxidoreductases. The novel oxidoreductase, here named BsP315 has 21 kDa and iron and molybdenum bound to its catalytic site, additionally we have isolated a catalase here named BsCat / Doutorado / Quimica Organica / Doutora em Ciências
63

Morfologia comparada, ontogenia e alometria de estruturas das tíbias anteriores e descrição de imaturos de percevejos predadores (Hemiptera: Pentatomidae: Asopinae)

Brugnera, Ricardo January 2018 (has links)
Estudos morfológicos representam ferramentas básicas para ampliação do conhecimento sobre determinado táxon e abrem caminhos para o desenvolvimento de outros estudos em diversas áreas como taxonomia, filogenia, etologia e ecologia. Neste trabalho, buscamos aprimorar o conhecimento morfológico na família Pentatomidae, investigando as variações presentes nas pernas de percevejos e como elas se desenvolvem ao longo do ciclo de vida. Estudando comparativamente as expansões tibiais e o aparato tibial na subfamília Asopinae, e verificamos que ambas as estruturas possuem uma ampla variação morfológica. As expansões podem estar presentes nas superfícies dorsal e ventral da tíbia, ou apenas na dorsal. A estrutura pode apresentar diferentes tamanhos entre as espécies, podendo ser até duas vezes a largura do eixo central da tíbia como nos gêneros Cazira e Heteroscelis, ou em outros casos como Alceorrhynchus, que se apresenta de forma diminuta. Além disso, as expansões podem ocorrer ao longo de toda a tíbia, ou apenas apicalmente. Em relação ao aparato tibial, verificamos que o número de cerdas é bastante variável entre as espécies analisadas, e que possui relação com o tamanho geral do inseto. Ainda, verificamos que a região circundante à estrutura apresenta morfologia variável. Com base nas variações encontradas, dez caracteres morfológicos foram propostos. Além dos adultos, estudamos a morfologia e alometria da tíbia ao longo da ontogenia em nove espécies de Pentatomidae das subfamílias Asopinae, Pentatominae e Edessinae. Foi constatado que o número de cerdas aumenta em cada estágio de desenvolvimento nas espécies de Asopinae, enquanto nas demais o número se mantém praticamente o mesmo. A alometria do aparato tibial se demonstrou positiva para todas as espécies de Asopinae nos testes realizados, enquanto nas subfamílias Pentatominae e Edessinae a alometria da estrutura foi maioritariamente negativa ou isométrica. Foi demonstrado que assim como em outros insetos, as pernas apresentam um crescimento acelerado em comparação com outras estruturas do corpo, neste caso, da cabeça. Além disso, constatamos que a largura de tíbia apresenta uma queda de tamanho do quinto ínstar para o estágio Adulto, e hipotetizamos que este fenômeno possa ter relação com a perda de estruturas presentes nas pernas das ninfas responsáveis por dar maior suporte ao peso do inseto. Os estágios imaturos de Tynacantha marginata Dallas são descritos, estruturas corporais são exploradas e comparadas morfologicamente, e características diagnósticas que permitem a identificação dos ovos e ninfas da espécie são fornecidas. / Morphological studies are basic tools to increase knowledge about a given taxon, opening paths for the development of other studies in several areas such as taxonomy, phylogeny, ethology and ecology. In this work, we aimed to improve the morphological knowledge in the Pentatomidae family, examining the variations present in the legs of stink bugs and how they develop throughout the life-cycle. Comparatively studying the tibial expansions and the foretibial apparatus in the Asopinae subfamily, we found that both structures have a wide morphological variation. The expansions may be present on the dorsal and ventral surfaces of the foretibia, or only on the dorsal surface. The structure can present different sizes between the species, being able to be up to twice the width of the tibial axis as in the genus Cazira and Heteroscelis, or in other cases like Alceorrhynchus, appears in a diminutive form. Besides, the expansions may occur along the entire tibia, or only apically. In relation to the foretibial apparatus, we verified that the number of setae is quite variable among the analyzed species, and that it is related with the general size of the insect. Also, we verified that the region surrounding the structure presents variable morphology. Based on the variations found, ten morphological characters are proposed. In addition to the adults, we studied the morphology and allometry of the foretibia along the ontogeny in nine species of Pentatomidae of the subfamilies Asopinae, Pentatominae and Edessinae. It was observed that the number of setae increases at each stage of development in the Asopinae species, while in the others the number remains practically the same. Allometry of the tibial apparatus was shown to be positive for all Asopinae species in the performed tests, while in the Pentatominae and Edessinae subfamilies the allometry of the structure was mostly negative or isometric. It has demonstrated that, as in other insects, the legs exhibit accelerated growth compared to other structures of the body, in our case, the head. In addition, we verified that tibia width shows a decrease in size of the fifth instar for the adult stage, and hypothesized that this phenomenon is related to the loss of structures present in the legs of the nymphs responsible for giving support to the weight of the insect. The immature stages of Tynacantha marginata Dallas are described, body structures are explored and morphologically compared and diagnostic features that allow identification of the eggs and nymphs of the species are provided.
64

Determining the response of the bed bug (<i>Cimex lectularius</i> L.) to heat exposure at the population, behavioral, and physiological levels

Aaron R Ashbrook (8771363) 29 April 2020 (has links)
The focus of this dissertation is on bed bug thermal biology. How bed bugs react to heat exposure at the population, behavioral, and physiological levels was explored. The thermal tolerance of different bed bug populations and sublethal effects heat exposure were investigated. The temperatures that cause bed bugs to flee from their harborages was determined using a custom made arena. How bed bug physiology changes after heat exposure was determined using RT-qPCR. Finally, how conspecifics react to bed bugs that have been lethally exposed to heat was determined using still air bioassays.<br>
65

CONFPROFITT: A CONFIGURATION-AWARE PERFORMANCE PROFILING, TESTING, AND TUNING FRAMEWORK

Han, Xue 01 January 2019 (has links)
Modern computer software systems are complicated. Developers can change the behavior of the software system through software configurations. The large number of configuration option and their interactions make the task of software tuning, testing, and debugging very challenging. Performance is one of the key aspects of non-functional qualities, where performance bugs can cause significant performance degradation and lead to poor user experience. However, performance bugs are difficult to expose, primarily because detecting them requires specific inputs, as well as specific configurations. While researchers have developed techniques to analyze, quantify, detect, and fix performance bugs, many of these techniques are not effective in highly-configurable systems. To improve the non-functional qualities of configurable software systems, testing engineers need to be able to understand the performance influence of configuration options, adjust the performance of a system under different configurations, and detect configuration-related performance bugs. This research will provide an automated framework that allows engineers to effectively analyze performance-influence configuration options, detect performance bugs in highly-configurable software systems, and adjust configuration options to achieve higher long-term performance gains. To understand real-world performance bugs in highly-configurable software systems, we first perform a performance bug characteristics study from three large-scale opensource projects. Many researchers have studied the characteristics of performance bugs from the bug report but few have reported what the experience is when trying to replicate confirmed performance bugs from the perspective of non-domain experts such as researchers. This study is meant to report the challenges and potential workaround to replicate confirmed performance bugs. We also want to share a performance benchmark to provide real-world performance bugs to evaluate future performance testing techniques. Inspired by our performance bug study, we propose a performance profiling approach that can help developers to understand how configuration options and their interactions can influence the performance of a system. The approach uses a combination of dynamic analysis and machine learning techniques, together with configuration sampling techniques, to profile the program execution, analyze configuration options relevant to performance. Next, the framework leverages natural language processing and information retrieval techniques to automatically generate test inputs and configurations to expose performance bugs. Finally, the framework combines reinforcement learning and dynamic state reduction techniques to guide subject application towards achieving higher long-term performance gains.
66

Cytogenetická charakteristika štěnic rodu Cimex (Heteroptera: Cimicidae) / Cytogenetic characteristics of the genus Cimex (Heteroptera: Cimicidae)

Sadílek, David January 2021 (has links)
The present thesis deals with the phenomenon of additional sex chromosomes in Cimex lectularius (Hemiptera: Heteroptera: Cimicidae) using genome size analysis combined with the classical cytogenetic approach. Also, five other cimicid species and 12 species from the family Nabidae were analysed identically for comparative purposes. The thesis also pursues a description of methodical approaches of cytogenetics and flow cytometry in the study of C. lectularius. Recently analysed European specimens of C. lectularius from human host exhibited 12 distinct cytotypes, with a variable number of chromosomes X from two to 20 (2n♂ = 26+X1X2Y to 26+X1-20+Y). The fragmentation hypothesis of C. lectularius additional chromosomes X origin was established in the second half of the 20th century. However, the present genome size measurements suggest that various chromosomal rearrangements as duplication or deletion besides the fragmentation could occur. Males with basic cytotype 2n = 26+X1X2Y had average genome size of 2C = 1.94 pg, in contrast male with 2n = 26+X1-7+Y yielded 2C = 2.26 pg and also specimens with genome size decrease 2C = 1.69 pg appeared. The most informative turned up to be the relative genome size of sperm cells n = 13+X1X2 and n = 13+Y, where specimens with higher chromosome number showed...
67

USING TEMPORAL NETWORKS TO FIND THE INFLUENCER NODE OF THE BUGGY SITES IN THE CODE COMMUNITIES

Kanwardeep Singh Walia (12091133) 14 April 2022 (has links)
<p>The cyber-attacks have increased, and with everything going digital, data theft has become a significant issue. This raises an alarm on the security of the source code. Sometimes, to release products early, the security of the code is compromised. Static analysis tools can help in finding possible security issues. Identifying and fixing the security issues may overwhelm the software developers. This process of "fixing" the errors or securing the code may take a lot of time, and the product may be released before all the errors are fixed. But these vulnerabilities in the source code may cost millions of dollars in case of a data breach. It is important to fix the security issues in the source code before releasing the product. This leads to the question of how to fix errors quickly so products can be rolled out with fewer security issues? A possible solution is to use temporal networks to find the influencer nodes in the source code. If these influencer variables are fixed, the connected security issues depending on the influencer in the community (functions) will also get fixed. The research question of the study: Can we identify the influencer node of the buggy site in the source code using temporal networks (K-tool) if the buggy sites present in the source code are identified using static analysis? The study also aims to know if it is faster to find the influencer node using the K-tool than the betweenness centrality algorithm. This research is an "Applied research" and will target the code written in C programming language. Possible vulnerabilities that can be fixed include "Integer Overflow", "Out of bounds", and "Buffer overflow." In the future, we plan to extend to other errors such as "Improper input validation." In this research, we will discuss how we can find the influencer node of the vulnerability (buggy site) in the source code after running the static analysis. Fixing this influencer node will fix the remaining errors pointed out by the static analysis. This will help in reducing the number of fixes to be done in the source code so that the product can be rolled out faster with less security issues.</p> <p><br></p>
68

Software debugging using the debugger SAM4E Xplained Pro

Manoh, Nadia, Abdullah, Hamoud January 2018 (has links)
Inbyggda system finns i nästan alla enheter som används i vårt dagliga liv, som exempelvis mobiltelefoner, kylskåp och bilar. En del enheter kan vara betydligt känsligare än andra, vilket innebär att en bugg som existerar i ett system kan orsaka skada, till och med förlust av människoliv, eller orsakar ingen skada alls. Mjukvarutestning och mjukvarufelsökning genomförs för att reducera buggar i ett system.Utbildningsprogrammet Datateknik och Mobil IT på Malmö universitet fokuserar inte på att undervisa mjukvarufelsökning med hjälp av felsökningsverktyg. Således presenterar denna forskning en felsökningslaboration skapat för studenter som går Datateknik och Mobil IT, som anses hjälpa studenterna att få kunskap i hur man använder felsökningsverktyget SAM4E Xplained Pro för att lokalisera buggar. Som ett resultat, utfördes felsökningslaborationen av fyra studenter varav 75 procent av buggarna hittades och åtgärdades. / Embedded systems are found in almost every device used in our daily lives, including cell phones, refrigerators, and cars. Some devices may be significantly more sensitive than others, meaning a bug appearing in a system could cause harm, even loss of human lives or cause no harm at all. To reduce bugs in a system, software testing and software debugging are performed.The Computer Science program at Malmö University does not focus on teaching software debugging using a debugger. Thus, this thesis presents a debugging lab created for Computer Science students, considered to help them gain knowledge in how to use the debugger SAM4E Xplained Pro to locate bugs. As a result, four students performed the debugging lab of which 75 percent of the bugs were found and remedied.
69

Safe Concurrent Programming and Execution

Pyla, Hari Krishna 05 March 2013 (has links)
The increasing prevalence of multi and many core processors has brought the issues of concurrency and parallelism to the forefront of everyday computing. Even for applications amenable to traditional parallelization techniques, the subtleties of concurrent programming are known to introduce concurrency bugs. Due to the potential of concurrency bugs, programmers find it hard to write correct concurrent code. To take full advantage of parallel shared memory platforms, application programmers need safe and efficient mechanisms that can support a wide range of parallel applications. In addition, a large body of applications are inherently hard-to-parallelize; their data and control dependencies impose execution order constraints that preclude the use of traditional parallelization techniques. Sensitive to their input data, a substantial number of applications fail to scale well, leaving cores idle. To improve the performance of such applications, application programmers need effective mechanisms that can fully leverage multi and many core architectures. These challenges stand in the way of realizing the true potential of emerging many core platforms. The techniques described in this dissertation address these challenges. Specifically, this dissertation contributes techniques to transparently detect and eliminate several concurrency bugs, including deadlocks, asymmetric write-write data races, priority inversion, live-locks, order violations, and bugs that stem from the presence of asynchronous signaling and locks. A second major contribution of this dissertation is a programming framework that exploits coarse-grain speculative parallelism to improve the performance of otherwise hard-to-parallelize applications. / Ph. D.
70

Visualizing bug-prone code via version control metadata

Gradin, Simon January 2023 (has links)
Software being developed today can have years worth of history and hundreds if notthousands of files involved in a single project. When trying to determine what parts ofthe code need maintenance or updating it can be difficult to determine what will beproblematic in the future. Hours spent on code that will not cause problems in thefuture could be better used in other areas. Before changes are made to a codebase, themost error-prone parts of the code should be identified. In this thesis a method forcomparing what factors contribute to future bugs is developed, as well as testing severalfactors extracted from version control metadata using this method. In addition, avisualization was made using tree maps to show the most problematic files in a readablemanner, effectively using the produced data in an application to predict future bugs. Itwas determined that Age of newest change, Changes with age reducing importance andPrevious bugfixes with age reducing importance were all the most impactful factors forpredicting future bugs but that different repositories worked best with differentcombinations of the mentioned factors.

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