Le caféier Coffea arabica var. Laurina, aussi appelé Bourbon Pointu, est apparu à la Réunion suite à une mutation spontanée de la variété Bourbon. Cette mutation Laurina, monolocus et récessive, a des effets pléiotropiques qui différencie le Bourbon pointu du Bourbon. Au niveau morphologique, elle se caractérise par un nanisme, un port pyramidal et une forme pointue de ses graines. A un niveau moléculaire, la teneur des grains en caféine est fortement réduite. Malgré des caractéristiques agronomiques d'intérêt et d'excellentes qualités organoleptiques, peu d'études sont disponibles sur ce mutant naturel. Ce travail a ainsi pour objectif d'étudier la mutation Laurina et d'en caractériser les effets afin de mieux décrire les cascades de réaction mises en place. Il se base sur la comparaison du Bourbon pointu avec sa variété parente Bourbon. Au niveau morphologique, des mesures de croissance végétative ont permis l'analyse et l'explication de la forme pyramidale du mutant. Au niveau histologique, l'étude de l'apex, centre initiateur des organes de surface, et de différents entre-noeuds de l'axe orthotrope a permis d'expliquer l'origine du nanisme en terme de division et d'élongation cellulaire. Des hypothèses quant à l'action de la mutation Laurina sur certaines hormones ont été émises à partir des résultats d'application de gibbérelline exogène. Ces études macro et microscopiques ont été couplées au niveau moléculaire à la recherche de gènes différentiellement exprimés entre les deux variétés. La comparaison des transcriptomes des deux variétés à un stade précoce post-cotylédonaire avait pour but la recherche de gènes candidats impliqués dans les premières cascades de réactions menant aux effets pléiotropiques observés. Le clonage différentiel basé sur la méthode SSH (Hybridation Suppressive Soustractive) couplé à une étape de tri à haut débit (macro-array) a été appliqué à ces fins. L'ensemble des résultats décrit plus précisément les effets pléiotropiques induits par la mutation Laurina. La description précise des effets pléiotropiques de la mutation ouvre des pistes quant à la caractérisation moléculaire de la mutation à travers une approche gène candidat.

<p>In this thesis we explore in particular the dynamics of a special type of quasi-particle in pi-conjugated materials termed polaron, the origin of which is intimately related to the strong interactions between the electronic and the vibrational degrees of freedom within these systems. In order to conduct such studies with the particular focus of each appended paper, we simultaneously solve the time-dependent Schrödinger equation and the lattice equation of motion with a three-dimensional extension of the famous Su-Schrieffer-Heeger (SSH) model Hamiltonian. In particular, we demonstrate in Paper I the applicability of the method to model transport dynamics in molecular crystals in a region were neither band theory nor perturbative treatments such as the Holstein model and extended Marcus theory apply. In Paper II we expand the model Hamiltonian to treat the revolution of phenylene rings around the sigma-bonds and demonstrate the great impact of stochastic ring torsion on the intra-chain mobility in conjugated polymers using poly[phenylene vinylene] (PPV) as a model system. Finally, in Paper III we go beyond the original purpose of the methodology and utilize its great flexibility to study radiationless relaxations of hot excitons.</p> / Report code: LiU-TEK-LIC-2007:4.

Notre travail qui sinscrit dans le cadre général de létude du développement embryonnaire de Phaseolus a pour objectif principal disoler et de caractériser des gènes différemment exprimés chez les embryons en voie davortement, et donc nécessaires au développment normal des embryons. Des embryons en cours de dégénérescence issus des hybridations interspécifiques et de la mutagenèse induite ont été analysés. Des ADNc différemment exprimés chez ces embryons ont été identifiés par les techniques de lHybridation Soustractive Suppressive (HSS) et de la dot blot. Les hybridations interspécifiques ont été réalisées entre lespèce P. vulgaris L. utilisée comme parent mâle et les espèces P. coccineus L. et P. polyanthus Greenm. utilisées comme parents femelles (formes sauvages et cultivées). La mutagenèse induite à lEthyl Méthyl Sulfonate (EMS) a été appliquée sur le génotype BAT93 de P. vulgaris, une variété améliorée du CIAT. Dans les croisements P. coccineus x P. vulgaris, 938 hybridations ont été effectuées et le taux de gousses avortées au-delà de 8 JAP est denviron 12%. Quatre gousses supposées hybrides ont été obtenues. Pour les croisements P. polyanthus x P. vulgaris, 733 hybridations ont été réalisées. Le taux de gousses avortées au-delà de 8 JAP est denviron 18% et une seule gousse supposée hybride a été produite. Les caractères hybrides dune plante de chacune des deux combinaisons interspécifiques ont été mis en évidence au moyen de caractères morphologiques des fleurs et des graines, mais aussi grâce à lutilisation dun marqueur moléculaire, le microsatellite BM160. La mise en évidence et la caractérisation des embryons en voie davortement ont été effectuées à partir de matériels issus des hybridations interspécifiques et de la mutagenèse à lEthyl Méthyl Sulfonate (EMS). Les observations, faites sur des embryons extraits et sur des coupes histologiques dovules, révèlent des malformations au niveau du suspenseur et des cotylédons et des retards de croissance. Les plantes issues de la mutagenèse et produisant des graines avortant avant la maturité ont été croisées avec des plantes normales. Lanalyse de la F2 effectuée sur 96 plantes révèle une proportion mendélienne 3:1 de plantes avec des graines normales et de plantes avec graines qui avortent. Ce résultat suggère un contrôle du caractère « avortement des graines » par une paire dallèles récessifs. La technique de lHSS a permis disoler des fragments dADNs complémentaires différemment exprimés dans les graines en voie davortement. Lanalyse des séquences de ces ADNs complémentaires montre quils codent pour plusieurs protéines intervenant dans les développements cellulaire et embryonnaire. Les principales protéines sont le cytochrome P450, la myo-inositol 1-phosphate synthase, la peroxydase cationique, le voltage-dependent anion channel et la sucrose synthase. A lexception du cytochrome P450, les niveaux dexpression des autres gènes sont plus faibles dans les graines en voie davortement issues de la mutagenèse par rapport aux graines normales. The main objective of this study was to isolate and to characterize cDNAs differentially expressed in Phaseolus degenerating embryos. Aborting embryos from interspecific hybridizations and induced mutation were analysed. cDNAs differentially expressed in these embryos were isolated using the Suppressive Subtractive Hybridization (SSH) and the dot blot techniques. The interspecific hybridizations were performed between P. vulgaris L. used as male parent and P. coccineus L. and P. polyanthus Greenm. used as female parents (wild and cultivated forms). The induced mutation was performed whith Ethyl Methyl Sulfonate (EMS) applied on the genotype BAT93 of P. vulgaris, a breeding line from CIAT. A total number of 938 crosses P. coccineus x P. vulgaris and 733 crosses P. polyanthus x P. vulgaris were carried out. In the crosses P. coccineus x P. vulgaris, the rate of pod abortion after 8 days after pollination (DAP) is 12%. Four putative hybrid pods were obtained. The rate of pod abortion after 8 DAP in the crosses P. polyanthus x P. vulgaris is 18% and one putative hybrid pod was produced. The hybrid nature of one plant from each interspecific combination was confirmed using morphological characters of flowers and seeds and molecular marker (microsatellite BM160). The isolation and the characterization of degenerating embryos were realised with materials from interspecific hybridizations and from chemical mutagenesis with EMS. The observations of these two materials revealed abnormalities mainly in suspensor and cotyledons; and the embryos failed to grow normally. Plants from mutagenesis which produce degenerating seeds were crossed with normal plants. Genetic analysis on 96 F2 plants revealed a 3:1 Mendel ratio of plants with normal seeds and plants with degenerating seeds. This result suggests the control of the seed abortion trait by a single recessive gene. The SSH technique was used to isolate cDNAs fragments differentially expressed in aborting seeds. Analysis of the cDNAs sequences revealed that these cDNAs encode for proteins involved in cellular and embryonic development. The main proteins are cytochrome P450, myo-inositol 1-phosphate synthase, cationic peroxidase, voltage-dependent anion channel and sucrose synthase. All the genes showed a reduction of their expression in developing seeds of the mutagenized plants, compared to those observed in wild-type plants.

The company Västra Mälardalens Kommunalförbund, VMKF, wishes to revise and optimize their present data and IP-telephony network as of today consists of the three municipalities Köping, Arboga and Kungsör. As a municipal corporation, they seek consultation regarding internal as well as external review and investigation of the main structure of the network, its functionality and safety. By today’s increasing demands of Internet accessibility, availability of services and security far more extends the requirement of a complete network design. The foundation of networking rests on the balance between each of these necessities. Therefore, it is of grave importance to optimize a network design, use of hardware and to minimize the administrative overhead. In particular, when the municipality is short of resources and time means money. By letting an impartial investigation of the network act as a starting point it was established that several improvement could be applied. Among these a reconstructed and improved network topology that includes subjects as routing, switching, safety and security, quality of service and technical administrative overhead and the implementation of a real time monitoring of network bandwidth consumption. / Företaget Västra Mälardalens Kommunalförbund, VMKF, har önskemål om att granska och optimera deras befintliga data- och IP-telefoninätverk som i dagsläget spänner över de tre kommunerna Köping, Arboga och Kungsör. Som ett kommunalägt företag önskar de konsultation rörande intern såväl som extern granskning och optimering av huvuddelen av nätverkets funktionalitet samt säkerhet. I och med dagens ökade Internetanvändning och funktionalitetsbehov ställs allt högre krav på tillgänglighet, säkerhet och användarvänlighet. Nätverksteknik bygger mycket på balansen mellan dessa tre punkter. Därför gäller det att optimera nätverkets design, hårdvaruanvändning och att minimera administrativa laster. Detta i synnerhet då kommunens resurser är knappa och då tid i dagens samhälle innebär pengar. Genom att låta en granskning över nätverket som det ser ut i dag ligga till grund konstaterades att flertalet förbättringsmöjligheter kunde genomföras. Bland dessa återfinns en omstrukturerad nätverksdesign som innefattar routing, switching, säkerhet, QoS och teknisk administration samt implementeringen av en realtidsövervakning av bandbreddsanvändning.

国立情報学研究所で電子化したコンテンツを使用している。

The subject of web server security is vast, and it is becoming bigger as time passes by. Every year, researches, both private and public, are adding to the number of possible threats to the security of web servers, and coming up with possible solutions to them. A number of these solutions are considered to be expensive, complex, and incredibly time-consuming, while not able to create the perfect web to challenge any breach to the server security. In the study that follows, an attempt will be made to check whether a particular firewall can ensure a strong security measure and deal with some security breaches or severe threat to an existing web server. The research conducted has been done with the CSF Firewall, which provides a suit of scripts that ensure a portal’s security through a number of channels. The experiments conducted under the research provided extremely valuable insights about the application in hand, and the number of ways the CSF Firewall can help in safety of a portal against Secured Shell (SSH) attacks, dedicated to break the security of it, in its initial stages. It further goes to show how simple it is to actually detect the prospective attacks, and subsequently stop the Denial of Service (DoS) attacks, as well as the port scans made to the server, with the intent of breaching the security, by finding out an open port. By blocking the IP Addresses of the attackers dedicated to such an act, preventing them from creating nuisance, the CSF Firewall has been able to keep alien intrusions away from the server. It also aids in creating a secure zone for the server, to continue smoothly, while alerting the server administrators of the same, and gives them an opportunity to check those threatening IPs, and the time of attack, makes sure that the server administrators stay alert in the future, and is able to keep an eye on such attacks. In doing this, the experiment adds valuable data in the effective nature of the CSF Firewall.

This thesis is focused on developing a tool that is capable of generating cyber attacks. In the opening there are introduced some attacks using the ISO/OSI application layer protocols. Specifically, these are attacks known as Slowloris, RUDY, Slow Read, HTTP flood, and dictionary attack on the SSH. These attacks are implemented into an existing DoSgen Linux tool that already contains several famous network attacks. The main part of the thesis is devoted to the description of the tool and to the implementation of its own extension. The created tool is practically tested in an experimental enviroment against the Apache web server. Part of the thesis is the documentation for the improved DoSgen tool.

The thesis Establishment of the Linux internet gateway using advanced filtering focuses on~the installation of~the Linux operating system on~the older computers, that functions as a gateway to connect clients in the internal network to the Internet. The thesis describes creation an advanced filter with using iptables. Shows some types of security against attacks from the Internet. The other chapters are discussed, advanced traffic control mechanism (such as a TC and a qdisc). The system queue, it is highly beneficial where it is necessary to hierarchically divide traffic between users. It describes types of queue and assembled configurations for clients in the internal network. Next chapter describes the DNS server caching-only type and application denyhosts, which increases the overall security system. Have your own DNS server is certified, especially if we want to reduce the data traffic. Last chapter describes the RADIUS server and its implementation using Apache and MySQL database. Furthermore, the configuration options are described and the examples of the particular configurations are provided. Finally, it presented a system for authentication through the RADIUS server. The thesis seeks to provide a~complex view of security and filtering.

This project deals with analysis of brute force attacks focused on breaking authentication of common services (especially ssh) of Linux and xBSD operating systems. It also examines real attacks, actual tools and ways of detection of theese attacks. Finaly there are designed new mechanisms of coordination and evaluation of distributed brute force attacks in distributed environment. These mechanisms are then implemented in distributed system called DBFAP.

Master's thesis analyzes available network device configuration options and describes NETCONF configuration protocol and NETCONF event notifications extension in details. It describes Netopeer, open configuration platform developed on Liberouter project, and its pitote deployment as FlowMon probe remote configuration system. Newly designed Netopeer architecture, which adds support for NETCONF event notifications, was verified by reference implementation. Security of the new design and implementation was analyzed, and recommended system settings were provided. This Master's thesis is based on results of previous bachelor's thesis of author and on existing software tools developed by the Liberouter project.