Human endogenous retroviruses (HERVs) represent approximately 7% of the human genome. This investigation was focused on one particular HERV, ERV3, with the main purpose of characterising its gene expression patterns and genomic distribution of ERV3-like sequences. Furthermore, this careful expression study should provide insights into the biological role of HERVs. The impact of HERVs in health and disease is not yet clarified. ERV3 is expressed as three envelope (env) transcripts, of which two also contain a cellular gene, H-plk (human proviral linked Krüppel). ERV3 env expression was mainly investigated at the RNA level. The gene expression of two other HERVs, HERV-K and HERV-E was analysed and compared with ERV3 activity. Real-time PCRs were developed and in combination with in situ hybridisation, it was found that ERV3 is expressed in a tissue- and cell-specific way. High levels of ERV3 mRNA (up to six times over Histone3.3) were demonstrated in placenta, sebaceous glands, foetal and adult adrenal glands, brown adipose tissue, corpus luteum, pituitary gland, thymus and testis. In monocytic cells including both normal monocytes and malignant U-937 cells, elevated mRNA levels were observed after retinoic acid (RA)-induced differentiation. ERV3-encoded Env protein was detected in selected cases, one following RA-treatment. In addition, several new ERV3-like sequences were discovered in the human genome. ERV3 was found to have conserved open reading frames in contrast to other ERV3-like sequences in the human genome. This suggests that ERV3 may be involved in important cellular processes such as differentiation, cell fusion, immunomodulation and protection against infectious retroviruses. The developed techniques and obtained results will allow further studies of HERV expression to better correlate HERV activity to both normal development and disease.

No description available.

Notre mémoire prend pour objet d’étude les dix-sept textes brefs rassemblés dans le recueil Contes et nouvelles suivis du Théâtre, écrits durant la période symboliste et dans lesquels on constate un phénomène d’hybridation entre les genres narratif et dramatique ainsi qu’entre thèmes symbolistes et décadents. Le premier chapitre s’attache à l’étude de Contes et nouvelles suivis du Théâtre dans la perspective des poétiques du recueil afin de constituer les éléments qui en font une « anthologie de l’entre-deux » du corpus rachildien de textes brefs. En adoptant la perspective de la poétique des genres, il sera question dans le deuxième chapitre d’étudier l’hybridation des genres littéraires, plus précisément entre la prose narrative et le texte dramatique, donnant lieu à des textes en « prose dramatique » qui se situent entre texte à lire et à mettre en scène. Enfin, dans le troisième chapitre nous examinerons les thèmes et les motifs récurrents de l’imaginaire rachildien où s’entremêlent symbolisme et décadentisme, après nous être intéressée à « l’écriture artiste » sous la plume de Rachilde, qui permet de rendre « visibles » les différentes formes de spectres, d’illusions et d’ombres qui parsèment les textes de Contes et nouvelles suivis du Théâtre. / Since Rachilde is generally associated with the french Decadent mouvement, few people are informed that the author also contributed to the symbolist movement of the 1890’s by helping in the set-up of the Théâtre de l’Art and Théâtre de l’Œuvre and especially by composing plays, tales and short-stories which take part in the symbolist spirit of the late nineteenth century. Gathered in the collection Contes et nouvelles suivis du Théâtre published in 1900 by the Mercure de France, these seventeen texts written between 1890 and 1900 establish an anthology of what we call Rachilde’s "symbolist period" of short-story, tale and play writing. Our dissertation is interested in the phenomenon of hybridisation between narrative and dramatic genres as well as between decadent and symbolist themes in this collection little known amongst scholars and the general public. The first chapter of our dissertation becomes attached to the study of Contes et nouvelles suivis du Théâtre in the perspective of the poetics of the collection and examines how the combination of Rachilde’s texts leads to an "anthologie de l’entre-deux". In our second chapter, we adopt the viewpoint of the poetics of genre to discuss the hybridisation of literary genres in Contes et nouvelles suivis du Théâtre, more precisely the narrative and the dramatic genres, that result in "dramatic prose". Finally, in the third chapter, we shall examine the recurring themes of Rachilde’s writing, that entangles decadent and symbolist themes, after being interested in "le style artiste", which allows her to sketch "in a visible way" the various forms of spectres, illusions and shadows that strew the texts of Contes et nouvelles suivis du Théâtre.

Macrobrachium australiense is a common freshwater prawn found throughout most of eastern and inland Australia. Debate has been ongoing on the systematics of this species due to high morphological variation: past studies have relied on external morphology assessments to describe genetic relationships between populations. An individual's morphological phenotype results however, from an interplay of genetic factors, environmental, and interactions between genes and the environment. The current study examined the strength of genetic constraint on morphological traits in this species. Examination of over 1000 M. australiense museum specimens collected from across the species' extensive natural range, documented high phenotypic variation with no regional pattern of variation. Within regions, 88% of variation in morphological traits in mature males and juveniles was present between local rivers. Therefore, morphological variation is not structured at the regional level. If there is a strong genetic base to morphological variation then populations in a single river system must be evolving essentially in isolation. More intensive sampling within a single river system demonstrated high morphological variation in 600 M. australiense individuals from 18 populations within a geographically connected system. Populations separated by as little as 1km showed significant morphological differences in 50% of mature male traits. If morphological variation is primarily genetically based, then populations within a river system were evolving independently at a very fine spatial scale. This hypothesis was tested by breeding morphologically divergent populations of M. australiense in a controlled environment to isolate genetic influences on morphological variation. Low heritability for morphological traits in five divergent populations raised under identical environments established that there is no strict genetic control on morphological variation in these M. australiense populations. Morphologically homogenous offspring resulted from wild parents that had exhibited significant differences at 73% of traits examined. Therefore, the fundamental assumption that morphological variation in M. australiense is dictated by strict genetic control is not supported in these representative populations. Moreover, significant variation in 41% of morphological traits was produced by raising a single population at different environmental temperatures (28oC and 22 oC). A single homogenous stock of M. australiense should not produce morphologically divergent offspring if genetic factors are the major influence of phenotypic expression. Crossing of pure line divergent stocks resulted in hybrid offspring with significant differences in 50% of female morphological traits, whereas male offspring varied for only 31% of morphological traits. This result suggests that female morphological expression is affected more strongly by genetic factors than male offspring in this trial. The growth and maturation of external morphological traits during development in M. australiense is under limited genetic constraint, especially in the later phases of growth. Only 17% of traits varied between juvenile stocks in the last three months of development when individuals were exposed to identical environmental conditions. Maturation size was homogenous, except for females in the absence of maturing males in divergent stocks exposed to identical environmental conditions. Females were much larger in size and shape of morphological traits in the absence of mature males in the population. Thus environmental factors strongly influence phenotypic expression of external morphology in M. australiense. Past problems with the taxonomy of this species are therefore understandable as many important traits used in systematics appear to be under limited genetic control. Past evolutionary studies based on morphological diversity in this species therefore may be unreliable as the traits used to identify divergent forms may not provide a true reflection of genetic divergence.

The availability of DNA samples that are of adequate quality and quantity is essential for any genetic analysis. The fields of forensic biology and clinical diagnostic pathology testing often suffer from limited samples that yield insufficient DNA material to allow extensive analysis. This study examined the utility of a recently introduced whole genome amplification method termed Multiple Displacement Amplification (MDA) for amplifying a variety of limited sample types that are commonly encountered in the fields of forensic biology and clinical diagnostics. The MDA reaction, which employs the highly processive bacteriophage φ29 DNA polymerase, was found to generate high molecular weight template DNA suitable for a variety of downstream applications from low copy number DNA samples down to the single genome level. MDA of single cells yielded sufficient DNA for up to 20,000,000 PCR assays, allowing further confirmatory testing on samples of limited quantities or the archiving of precious DNA material for future work. The amplification of degraded DNA material using MDA identified a requirement for samples of sufficient quality to allow successful synthesis of product DNA templates. Furthermore, the utility of MDA products in comparative genomic hybridisation (CGH) assays identified the presence of amplification bias. However, this bias was overcome by introducing a novel modification to the MDA protocol. Future directions for this work include investigations into the utility of MDA products in short tandem repeat (STR) assays for human identifications and application of the modified MDA protocol for testing of single cell samples for genetic abnormalities.

In the late 1990s, a series of landmark publications described RNA interference (RNAi) and related RNA silencing phenomena in nematodes, plants and fungi. By manipulating RNA silencing, biologists have been able to create tools for specifically inactivating genes. In organisms from trypanosomes to insects, RNA silencing is now indispensible for studying gene function. RNA silencing has been used in a project aimed at systematically knocking out all genes in the model plant Arabidopsis thaliana. RNA silencing has a natural role in defending eukaryotic cells against virus replication. By assembling virus DNA sequences in a form that triggers RNA silencing, biologists have created plants resistant to specific viruses. In this study, we set out to test if a similar approach would protect plants against infection by the agriculturally important Brassica pathogen, Plasmodiophora brassicae. P. brassicae is an obligate intracellular biotroph, from the little studied eukaryotic supergroup, the Rhizaria. To identify the gene sequences that would be starting material for P. brassicae RNA silencing, new P. brassicae genes were gathered by cDNA cloning or genomic PCR-walking. Using suppression subtractive hybridisation (SSH) and oligo-capping cloning of full-length cDNAs, 76 new gene sequences were identified. A large proportion of the cDNAs were predicted to contain signal peptides for ER translocation. In addition to the new cDNA identified here, partial sequences for the P. brassicae actin and TPS genes were published by other researchers close to the beginning of this study. Using PCR-walking, full-length genomic DNA sequences from both genes were obtained. Later, genomic DNA sequences spanning or flanking a total of 24 P. brassicae genes were obtained. The P. brassicae genes were rich in typical eukaryotic spliceosomal introns. Transcription of P. brassicae genes also appears likely to begin from initiator elements rather than TATA-box-containing promoters. A segment of the P. brassicae actin gene was assembled in hairpin format and transformed into Arabidopsis thaliana. Observation of simultaneous knockdown of the GUS marker gene as well as detection of siRNAs indicated that the hpRNA sequences induced RNA silencing. However, inoculation of these plants with P. brassicae resulted in heavy club root infection. We were unable to detect decreases in actin gene expression in the infecting P. brassicae, at either early or late stages of infection. We conclude that, within the limits of the techniques used here, there is no evidence for induction of RNA silencing in P. brassicae by in planta produced siRNAs.

In the late 1990s, a series of landmark publications described RNA interference (RNAi) and related RNA silencing phenomena in nematodes, plants and fungi. By manipulating RNA silencing, biologists have been able to create tools for specifically inactivating genes. In organisms from trypanosomes to insects, RNA silencing is now indispensible for studying gene function. RNA silencing has been used in a project aimed at systematically knocking out all genes in the model plant Arabidopsis thaliana. RNA silencing has a natural role in defending eukaryotic cells against virus replication. By assembling virus DNA sequences in a form that triggers RNA silencing, biologists have created plants resistant to specific viruses. In this study, we set out to test if a similar approach would protect plants against infection by the agriculturally important Brassica pathogen, Plasmodiophora brassicae. P. brassicae is an obligate intracellular biotroph, from the little studied eukaryotic supergroup, the Rhizaria. To identify the gene sequences that would be starting material for P. brassicae RNA silencing, new P. brassicae genes were gathered by cDNA cloning or genomic PCR-walking. Using suppression subtractive hybridisation (SSH) and oligo-capping cloning of full-length cDNAs, 76 new gene sequences were identified. A large proportion of the cDNAs were predicted to contain signal peptides for ER translocation. In addition to the new cDNA identified here, partial sequences for the P. brassicae actin and TPS genes were published by other researchers close to the beginning of this study. Using PCR-walking, full-length genomic DNA sequences from both genes were obtained. Later, genomic DNA sequences spanning or flanking a total of 24 P. brassicae genes were obtained. The P. brassicae genes were rich in typical eukaryotic spliceosomal introns. Transcription of P. brassicae genes also appears likely to begin from initiator elements rather than TATA-box-containing promoters. A segment of the P. brassicae actin gene was assembled in hairpin format and transformed into Arabidopsis thaliana. Observation of simultaneous knockdown of the GUS marker gene as well as detection of siRNAs indicated that the hpRNA sequences induced RNA silencing. However, inoculation of these plants with P. brassicae resulted in heavy club root infection. We were unable to detect decreases in actin gene expression in the infecting P. brassicae, at either early or late stages of infection. We conclude that, within the limits of the techniques used here, there is no evidence for induction of RNA silencing in P. brassicae by in planta produced siRNAs.

Étant donné l'urgence environnementale, le développement des énergies renouvelables s'est fortement accru ces dernières années. L'implantation de champs d'éoliennes est notamment en pleine expansion dans toute l'Europe. Ces éoliennes, de structure diélectrique et métallique et de grande taille, peuvent avoir un impact significatif sur les systèmes radiofréquences. En particulier, les systèmes de radionavigation et de surveillance opérés par la DGAC (VOR, radar) doivent cohabiter avec de nouveaux champs d'éoliennes. En effet, ces dernières influent sur le champ électromagnétique des systèmes et peuvent dégrader leurs performances (multitrajets, masquages... ). Il est alors important de pouvoir quantifier ces dégradations, en particulier dans le cas du VOR où les multitrajets engendrent une erreur de relèvement. Dans ce travail de thèse, un simulateur électromagnétique appelé VERSO (VOR ERror SimulatOr) est développé. Il permet d'estimer l'impact d'objets diffractants, en particulier d'éoliennes, sur le signal VOR. Dans la littérature, différentes techniques de modélisation sont proposées pour prédire ces phénomènes. Certaines sont trop approximatives, d'autres trop coûteuses en temps. Ainsi, le choix des techniques utilisées dans ce simulateur a été guidé par le compromis entre précision et temps de calcul. L'équation parabolique est utilisée pour modéliser la propagation de la source jusqu'aux éoliennes afin de prendre en compte le relief. Ensuite, une méthode d'optique physique sur matériaux diélectriques est mise en œuvre pour calculer le champ diffracté par ces objets. Le modèle électromagnétique de l'éolienne et les hypothèses inhérentes aux méthodes utilisées par VERSO ont été validés aux fréquences VHF (VOR) par comparaison avec la méthode des moments qui fait office de référence. Une extension de VERSO pour les systèmes radars a été abordée. Par conséquent des validations similaires à ces fréquences ont été réalisées. Plus spécifiquement, un modèle de pale d'éolienne prenant en compte la présence du parafoudre est proposé aux fréquences VOR et radar. Les effets de masquage sont eux aussi quantifiés pour ces 2 domaines de fréquences. Il est notamment démontré que l'effet de masquage pour des éoliennes alignées radialement à un VOR est négligeable. Cette approximation ainsi que le modèle de pale sont ensuite utilisés dans le programme VERSO. Ce dernier est validé à l'aide de contrôles en vol sur un scénario de 9 éoliennes implantées à 5 km du VOR de Boulogne-sur-Mer. Une étude quantitative de l'impact de chaque partie des éoliennes est menée afin de discriminer la source majoritaire d'erreur VOR. On constate notamment qu'à grande distance du VOR dans le scénario d'observation considéré, le mât constitue le principal contributeur en terme de champ diffracté et d'erreur VOR. Enfin, une étude statistique sur l'erreur VOR a permis d'obtenir un simulateur de scénarios qui donne l'erreur maximale avec une confiance fixée, en minimisant le nombre de simulations à effectuer. Pour accélérer cette méthode, une expression analytique approchée de l'erreur VOR maximum a été développée en fonction de la distance d'implantation et de la hauteur du mât de l'éolienne. Cette dernière étude fournit une méthode rapide pour évaluer l'impact de la construction d'un champ d'éoliennes quelconque à proximité de systèmes de l'aviation civile. / Considering the ecological emergency, the renewable energy development has greatly increased for a decade. In particular, the windfarms implantation rapidly expands in Europe. These windturbines are large obstacles composed by dielectric and metallic materials. So their impact on electromagnetic devices is significant. The radionavigation systems for the civil aviation services are particularly concerned. However, they have to work side with new windfarms. Actually, these latter cause scattering effects on the electromagnetic signals and can degrade the performances of these equipments (multipaths, shadowing effects etc.). Thus, quantifying these degradations is crucial, particularly on the VOR devices where multipath effects cause an error on the azimuth. In this thesis work, an electromagnetic simulator called VERSO (VOR ERror SimulatOr) is developed. It can estimate the impact of scattering objects, especially windturbines, on the VOR signal. In literature, several techniques are proposed to model these phenomena: some make coarse approximations and some others are memory intensive. Thus, the choice over the methods used in VERSO is a compromise between precision and memory requirement. The parabolic equation is used to model the propagation from the source to the windturbines so as to take the relief into account. A physical optic based method is used to compute the field scattered by these objects. The electromagnetic model of the windturbine and the hypothesis due to the methods used by VERSO have been validated in the VHF (VOR) frequency by comparison with the method of moments, which is the reference. An extension of VERSO for the radar systems is introduced. Consequently similar validations have been performed at radar frequencies. In particular, a windturbine blade model taking into account the lightning protection is proposed for the VOR and the radar frequencies. The shadowing effects are also quantified in both frequency domains. Especially, a demonstration that the shadowing effects due to radially implemented windturbines can be neglected around a VOR beacon is proposed. This approximation and the blade model are used for the implementation of VERSO. This simulator is validated by comparison with measurements on 9 windturbines built 5~km far from a VORC in Boulogne-sur-Mer (France). A study is performed to quantify the influence of each part of the windturbine. The mast is shown to be the main contributor regarding to the electromagnetic field and the VOR error. Finally, parametric simulations are performed and analytic expressions are proposed to describe the evolution of the maximum VOR error with respect to the mast size and the distance VOR-windturbine. The latter study gives some key parameters that need to be considered for the elaboration of a windfarm building plan close to civil aviation systems for the project to be viable.

Since the time RNA has been discovered by the nature scientist Miescher the structure and function of it has been forgotten for a long time. The prime role in science had always DNA. An increase of interest in RNA came with the discovery of the tRNA structure and its catalytic and enzymatic properties. These discoveries led to a great development wave of bioinformatics and structure and function analysis of RNA.

Fallopiajaponica (Houtt.) Ronse Decraene (Japanese knotweed), an introduced, invasive, rhizomatous perennial plant, has become an increasing problem for nature conservation and land management in both rural and urban areas in the British Isles. In the native range of the plant, Japan, Taiwan and northern China, a number of varieties are recorded. Three congeners of F. japonica are present in the British Isles, F. sachalinensis, F. japonica var. conipacta and F. baldschuanica in addition to a hybrid F. x bohemica. An investigation by postal survey of the distribution of the hybrid F. x bohemica has identified 131 records for the British Isles. Both male and female plants of F. x bohemica have been recorded. Current understanding suggests that only female plants of F. japonica are present in the British Isles, inferring that the only means of reproduction is through vegetative regeneration. High rates of regeneration were recorded in this study for stem and rhizome material for both F. japonica and F. x bohemica in an aquatic and terrestrial environment. Implications of vegetative regeneration are discussed in terms of current management practices and future methods of control. A combination of digging with a mechanical excavator followed by spraying with the herbicide glyphosate decreased the time required to achieve an effective level of control of F. japonica compared to spraying alone. Fragmentation of the rhizome system through digging resulted in an increase in stem density allowing a more effective delivery of herbicide. Implications in terms of costs for F. japonica treatment on sites awaiting re-development are discussed. Analysis of data collated from surveys of F. japonica in Swansea using a Geographical Information System suggest that the primary habitats infested are waste ground and stream and river banks. Results suggest that disturbance, both by natural means and by human intervention has been the primary cause of spread of F. japonica in the British Isles. Management strategies are proposed which take account of these results and measures are put forward to help prevent future infestations.