Phosphorylation-dependent dimerization and subcellular localization of islet-brain 1/c-Jun N-terminal kinase-interacting protein 1.

Islet-brain 1 [IB1; also termed c-Jun N-terminal kinase (JNK)-interacting protein 1 (JIP-1] is involved in the apoptotic signaling cascade of JNK and functions as a scaffold protein. It organizes several MAP kinases and the microtubule-transport motor protein kinesin and relates to other signal-transducing molecules such as the amyloid precursor protein. Here we have identified IB1/JIP-1 using different antibodies that reacted with either a monomeric or a dimeric form of IB1/JIP-1. By immunoelectron microscopy, differences in the subcellular localization were observed. The monomeric form was found in the cytoplasmic compartment and is associated with the cytoskeleton and with membranes, whereas the dimeric form was found in addition in nuclei. After treatment of mouse brain homogenates with alkaline phosphatase, the dimeric form disappeared and the monomeric form decreased its molecular weight, suggesting that an IB1/JIP-1 dimerization is phosphorylation dependent and that IB1 exists in several phospho- forms. N-methyl-D-aspartate receptor activation induced a dephosphorylation of IB1/JIP-1 in primary cultures of cortical neurons and reduced homodimerization. In conclusion, these data suggest that IB1/JIP-1 monomers and dimers may differ in compartmental localization and thus function as a scaffold protein of the JNK signaling cascade in the cytoplasm or as a transcription factor in nuclei.

Organisation of genetic variation in multinucleate arbuscular mycorrhizal fungi

Les Champignons Endomycorhiziens Arbusculaires (CEA) forment une symbiose racinaire avec environ 80% des espèces connues de plantes vasculaires. Ils occupent une position écologique très importante liée aux bénéfices qu'ils confèrent aux plantes. Des études moléculaires effectuées sur des gènes ribosomaux ont révélé un très grand polymorphisme, tant à l'intérieur des espèces qu'entre celles-ci. Ces champignons étant coenocytiques et multinucléés, l'organisation de cette variabilité génétique intraspécifique pourrait avoir différentes origines. Ce travail se propose d'examiner l'organisation et l'évolution de cette variabilité. Sur la base de fossiles, l'existence des CEA remonte à au moins 450 millions d'années. Cette symbiose peut donc être considérée comme ancienne. Les premières données moléculaires n'indiquant pas de reproduction sexuée, une hypothèse fut élaborée stipulant que les CEA seraient des asexués ancestraux. La première partie de cette thèse (chapitre 2) met en évidence l'existence de recombinaison dans différents CEA mais montre également que celle-ci est insuffisante pour purger les mutations accumulées. La reproduction étant essentiellement asexuée, on peut prédire que les nombreux noyaux ont probablement divergé génétiquement. En collaboration avec M. Hijri nous avons pu vérifier cette hypothèse (chapitre 2). Dans le chapitre 3 j'ai cherché à comprendre si le polymorphisme était également présent dans une population naturelle du CEA Glomus intraradices au niveau intraspécifique, ce qui n'avait encore jamais été examiné. En comparant les empreintes génétiques d'individus obtenus chacun à partir d'une spore mise en culture, j'ai clairement démontré que d'importantes différences génétiques existent entre ceux-ci. Un résultat similaire, portant sur des traits quantitatifs d'individus de la même population, a été trouvé par A. Koch. Les deux études en ensemble montre que le polymorphisme génétique dans cette population est suffisamment grand pour être important au niveau écologique. Dans le chapitre 4, j'ai cherché a examiner le polymorphisme des séquences du gène BiP au sein d'un individu. C'est la première étude qui examine la diversité génétique du génome de CEA avec un autre marqueur que l'ADN ribosomique. J'ai trouvé 31 types de séquences différentes du gène BiP issu d'un isolat de G. intraradices mis en culture à partir d'une seule spore. Cette variation n'était pas restreinte à des zones sélectivement neutres du BiP. Mes résultats montrent qu'il y a un grand nombre de variants non-fonctionnels, proportionnellement au faible nombre de copies attendues par noyau. Ceci va dans le sens d'une partition de l'information génétique entre les noyaux.<br/><br/>Arbuscular mycorrhizal fungi (AMF) are root symbionts with about 80% of all known species of vascular land plants. AMF are ecologically important because of the benefits that they confer to plants. Molecular studies on AMF showed that rDNA sequences were highly variable between species and within species. Because AMF are coenocytic and multinucleate there are several possibilities how this intraspecific genetic variation could be organized. Therefore, the organization and evolution of this variation in AMF were investigated in the present work. Based on fossil records the AMF symbiosis has existed for 450 Million years and is therefore considered ancient. First molecular data indicated no evident sexual reproduction and gave rise to the hypothesis that AMF might be ancient asexuals. The first part of this thesis (Chapter 2) shows evidence for recombination in different AMF but also indicates that it has not been frequent enough to purge accumulated mutations. Given asexual reproduction, it has been predicted that the many nuclei in AMF should diverge leading to genetically different nuclei. This hypothesis has been confirmed by an experiment of M. Hijri and is also included in chapter 2 as the results were published together. In chapter 3 I then investigated whether intraspecific genetic variation also exists in a field population of the AMF Glomus intraradices. Comparing genetic fingerprints of individuals derived from single spores I could clearly show that large genetic differences exist. A similar result, based on quantitative genetic traits, was found for the same population by A. Koch. The two studies taken together show that the genetic variation observed in the population is high enough to be of ecological relevance. Lastly, in chapter 4, I investigated within individual genetic variation among BiP gene sequences. It is the first study that has analyzed genetic diversity in the AMF genome in a region of DNA other than rDNA. I found 31 sequence variants of the BiP gene in one G. intraradices isolate that originated from one spore. Genetic variation was not only restricted to selectively neutral parts of BiP. A high number of predicted non-functional variants compared to a likely low number of copies per nucleus indicated that functional genetic information might even be partitioned among nuclei. The results of this work contribute to our understanding of potential evolutionary strategies of ancient asexuals, they also suggest that genetic differences in a population might be ecologically relevant and they show that this variation even occurs in functional regions of the AMF genome.

Development of a 3D very high-resolution seismic reflection system for lacustrine settings - a case study over a thrust fault zone in Lake Geneva

Un système efficace de sismique tridimensionnelle (3-D) haute-résolution adapté à des cibles lacustres de petite échelle a été développé. Dans le Lac Léman, près de la ville de Lausanne, en Suisse, des investigations récentes en deux dimension (2-D) ont mis en évidence une zone de faille complexe qui a été choisie pour tester notre système. Les structures observées incluent une couche mince (<40 m) de sédiments quaternaires sub-horizontaux, discordants sur des couches tertiaires de molasse pentées vers le sud-est. On observe aussi la zone de faille de « La Paudèze » qui sépare les unités de la Molasse du Plateau de la Molasse Subalpine. Deux campagnes 3-D complètes, d?environ d?un kilomètre carré, ont été réalisées sur ce site de test. La campagne pilote (campagne I), effectuée en 1999 pendant 8 jours, a couvert 80 profils en utilisant une seule flûte. Pendant la campagne II (9 jours en 2001), le nouveau système trois-flûtes, bien paramétrés pour notre objectif, a permis l?acquisition de données de très haute qualité sur 180 lignes CMP. Les améliorations principales incluent un système de navigation et de déclenchement de tirs grâce à un nouveau logiciel. Celui-ci comprend un contrôle qualité de la navigation du bateau en temps réel utilisant un GPS différentiel (dGPS) à bord et une station de référence près du bord du lac. De cette façon, les tirs peuvent être déclenchés tous les 5 mètres avec une erreur maximale non-cumulative de 25 centimètres. Tandis que pour la campagne I la position des récepteurs de la flûte 48-traces a dû être déduite à partir des positions du bateau, pour la campagne II elle ont pu être calculées précisément (erreur <20 cm) grâce aux trois antennes dGPS supplémentaires placées sur des flotteurs attachés à l?extrémité de chaque flûte 24-traces. Il est maintenant possible de déterminer la dérive éventuelle de l?extrémité des flûtes (75 m) causée par des courants latéraux ou de petites variations de trajet du bateau. De plus, la construction de deux bras télescopiques maintenant les trois flûtes à une distance de 7.5 m les uns des autres, qui est la même distance que celle entre les lignes naviguées de la campagne II. En combinaison avec un espacement de récepteurs de 2.5 m, la dimension de chaque «bin» de données 3-D de la campagne II est de 1.25 m en ligne et 3.75 m latéralement. L?espacement plus grand en direction « in-line » par rapport à la direction «cross-line» est justifié par l?orientation structurale de la zone de faille perpendiculaire à la direction «in-line». L?incertitude sur la navigation et le positionnement pendant la campagne I et le «binning» imprécis qui en résulte, se retrouve dans les données sous forme d?une certaine discontinuité des réflecteurs. L?utilisation d?un canon à air à doublechambre (qui permet d?atténuer l?effet bulle) a pu réduire l?aliasing observé dans les sections migrées en 3-D. Celui-ci était dû à la combinaison du contenu relativement haute fréquence (<2000 Hz) du canon à eau (utilisé à 140 bars et à 0.3 m de profondeur) et d?un pas d?échantillonnage latéral insuffisant. Le Mini G.I 15/15 a été utilisé à 80 bars et à 1 m de profondeur, est mieux adapté à la complexité de la cible, une zone faillée ayant des réflecteurs pentés jusqu?à 30°. Bien que ses fréquences ne dépassent pas les 650 Hz, cette source combine une pénétration du signal non-aliasé jusqu?à 300 m dans le sol (par rapport au 145 m pour le canon à eau) pour une résolution verticale maximale de 1.1 m. Tandis que la campagne I a été acquise par groupes de plusieurs lignes de directions alternées, l?optimisation du temps d?acquisition du nouveau système à trois flûtes permet l?acquisition en géométrie parallèle, ce qui est préférable lorsqu?on utilise une configuration asymétrique (une source et un dispositif de récepteurs). Si on ne procède pas ainsi, les stacks sont différents selon la direction. Toutefois, la configuration de flûtes, plus courtes que pour la compagne I, a réduit la couverture nominale, la ramenant de 12 à 6. Une séquence classique de traitement 3-D a été adaptée à l?échantillonnage à haute fréquence et elle a été complétée par deux programmes qui transforment le format non-conventionnel de nos données de navigation en un format standard de l?industrie. Dans l?ordre, le traitement comprend l?incorporation de la géométrie, suivi de l?édition des traces, de l?harmonisation des «bins» (pour compenser l?inhomogénéité de la couverture due à la dérive du bateau et de la flûte), de la correction de la divergence sphérique, du filtrage passe-bande, de l?analyse de vitesse, de la correction DMO en 3-D, du stack et enfin de la migration 3-D en temps. D?analyses de vitesse détaillées ont été effectuées sur les données de couverture 12, une ligne sur deux et tous les 50 CMP, soit un nombre total de 600 spectres de semblance. Selon cette analyse, les vitesses d?intervalles varient de 1450-1650 m/s dans les sédiments non-consolidés et de 1650-3000 m/s dans les sédiments consolidés. Le fait que l?on puisse interpréter plusieurs horizons et surfaces de faille dans le cube, montre le potentiel de cette technique pour une interprétation tectonique et géologique à petite échelle en trois dimensions. On distingue cinq faciès sismiques principaux et leurs géométries 3-D détaillées sur des sections verticales et horizontales: les sédiments lacustres (Holocène), les sédiments glacio-lacustres (Pléistocène), la Molasse du Plateau, la Molasse Subalpine de la zone de faille (chevauchement) et la Molasse Subalpine au sud de cette zone. Les couches de la Molasse du Plateau et de la Molasse Subalpine ont respectivement un pendage de ~8° et ~20°. La zone de faille comprend de nombreuses structures très déformées de pendage d?environ 30°. Des tests préliminaires avec un algorithme de migration 3-D en profondeur avant sommation et à amplitudes préservées démontrent que la qualité excellente des données de la campagne II permet l?application de telles techniques à des campagnes haute-résolution. La méthode de sismique marine 3-D était utilisée jusqu?à présent quasi-exclusivement par l?industrie pétrolière. Son adaptation à une échelle plus petite géographiquement mais aussi financièrement a ouvert la voie d?appliquer cette technique à des objectifs d?environnement et du génie civil.<br/><br/>An efficient high-resolution three-dimensional (3-D) seismic reflection system for small-scale targets in lacustrine settings was developed. In Lake Geneva, near the city of Lausanne, Switzerland, past high-resolution two-dimensional (2-D) investigations revealed a complex fault zone (the Paudèze thrust zone), which was subsequently chosen for testing our system. Observed structures include a thin (<40 m) layer of subhorizontal Quaternary sediments that unconformably overlie southeast-dipping Tertiary Molasse beds and the Paudèze thrust zone, which separates Plateau and Subalpine Molasse units. Two complete 3-D surveys have been conducted over this same test site, covering an area of about 1 km2. In 1999, a pilot survey (Survey I), comprising 80 profiles, was carried out in 8 days with a single-streamer configuration. In 2001, a second survey (Survey II) used a newly developed three-streamer system with optimized design parameters, which provided an exceptionally high-quality data set of 180 common midpoint (CMP) lines in 9 days. The main improvements include a navigation and shot-triggering system with in-house navigation software that automatically fires the gun in combination with real-time control on navigation quality using differential GPS (dGPS) onboard and a reference base near the lake shore. Shots were triggered at 5-m intervals with a maximum non-cumulative error of 25 cm. Whereas the single 48-channel streamer system of Survey I requires extrapolation of receiver positions from the boat position, for Survey II they could be accurately calculated (error <20 cm) with the aid of three additional dGPS antennas mounted on rafts attached to the end of each of the 24- channel streamers. Towed at a distance of 75 m behind the vessel, they allow the determination of feathering due to cross-line currents or small course variations. Furthermore, two retractable booms hold the three streamers at a distance of 7.5 m from each other, which is the same distance as the sail line interval for Survey I. With a receiver spacing of 2.5 m, the bin dimension of the 3-D data of Survey II is 1.25 m in in-line direction and 3.75 m in cross-line direction. The greater cross-line versus in-line spacing is justified by the known structural trend of the fault zone perpendicular to the in-line direction. The data from Survey I showed some reflection discontinuity as a result of insufficiently accurate navigation and positioning and subsequent binning errors. Observed aliasing in the 3-D migration was due to insufficient lateral sampling combined with the relatively high frequency (<2000 Hz) content of the water gun source (operated at 140 bars and 0.3 m depth). These results motivated the use of a double-chamber bubble-canceling air gun for Survey II. A 15 / 15 Mini G.I air gun operated at 80 bars and 1 m depth, proved to be better adapted for imaging the complexly faulted target area, which has reflectors dipping up to 30°. Although its frequencies do not exceed 650 Hz, this air gun combines a penetration of non-aliased signal to depths of 300 m below the water bottom (versus 145 m for the water gun) with a maximum vertical resolution of 1.1 m. While Survey I was shot in patches of alternating directions, the optimized surveying time of the new threestreamer system allowed acquisition in parallel geometry, which is preferable when using an asymmetric configuration (single source and receiver array). Otherwise, resulting stacks are different for the opposite directions. However, the shorter streamer configuration of Survey II reduced the nominal fold from 12 to 6. A 3-D conventional processing flow was adapted to the high sampling rates and was complemented by two computer programs that format the unconventional navigation data to industry standards. Processing included trace editing, geometry assignment, bin harmonization (to compensate for uneven fold due to boat/streamer drift), spherical divergence correction, bandpass filtering, velocity analysis, 3-D DMO correction, stack and 3-D time migration. A detailed semblance velocity analysis was performed on the 12-fold data set for every second in-line and every 50th CMP, i.e. on a total of 600 spectra. According to this velocity analysis, interval velocities range from 1450-1650 m/s for the unconsolidated sediments and from 1650-3000 m/s for the consolidated sediments. Delineation of several horizons and fault surfaces reveal the potential for small-scale geologic and tectonic interpretation in three dimensions. Five major seismic facies and their detailed 3-D geometries can be distinguished in vertical and horizontal sections: lacustrine sediments (Holocene) , glaciolacustrine sediments (Pleistocene), Plateau Molasse, Subalpine Molasse and its thrust fault zone. Dips of beds within Plateau and Subalpine Molasse are ~8° and ~20°, respectively. Within the fault zone, many highly deformed structures with dips around 30° are visible. Preliminary tests with 3-D preserved-amplitude prestack depth migration demonstrate that the excellent data quality of Survey II allows application of such sophisticated techniques even to high-resolution seismic surveys. In general, the adaptation of the 3-D marine seismic reflection method, which to date has almost exclusively been used by the oil exploration industry, to a smaller geographical as well as financial scale has helped pave the way for applying this technique to environmental and engineering purposes.<br/><br/>La sismique réflexion est une méthode d?investigation du sous-sol avec un très grand pouvoir de résolution. Elle consiste à envoyer des vibrations dans le sol et à recueillir les ondes qui se réfléchissent sur les discontinuités géologiques à différentes profondeurs et remontent ensuite à la surface où elles sont enregistrées. Les signaux ainsi recueillis donnent non seulement des informations sur la nature des couches en présence et leur géométrie, mais ils permettent aussi de faire une interprétation géologique du sous-sol. Par exemple, dans le cas de roches sédimentaires, les profils de sismique réflexion permettent de déterminer leur mode de dépôt, leurs éventuelles déformations ou cassures et donc leur histoire tectonique. La sismique réflexion est la méthode principale de l?exploration pétrolière. Pendant longtemps on a réalisé des profils de sismique réflexion le long de profils qui fournissent une image du sous-sol en deux dimensions. Les images ainsi obtenues ne sont que partiellement exactes, puisqu?elles ne tiennent pas compte de l?aspect tridimensionnel des structures géologiques. Depuis quelques dizaines d?années, la sismique en trois dimensions (3-D) a apporté un souffle nouveau à l?étude du sous-sol. Si elle est aujourd?hui parfaitement maîtrisée pour l?imagerie des grandes structures géologiques tant dans le domaine terrestre que le domaine océanique, son adaptation à l?échelle lacustre ou fluviale n?a encore fait l?objet que de rares études. Ce travail de thèse a consisté à développer un système d?acquisition sismique similaire à celui utilisé pour la prospection pétrolière en mer, mais adapté aux lacs. Il est donc de dimension moindre, de mise en oeuvre plus légère et surtout d?une résolution des images finales beaucoup plus élevée. Alors que l?industrie pétrolière se limite souvent à une résolution de l?ordre de la dizaine de mètres, l?instrument qui a été mis au point dans le cadre de ce travail permet de voir des détails de l?ordre du mètre. Le nouveau système repose sur la possibilité d?enregistrer simultanément les réflexions sismiques sur trois câbles sismiques (ou flûtes) de 24 traces chacun. Pour obtenir des données 3-D, il est essentiel de positionner les instruments sur l?eau (source et récepteurs des ondes sismiques) avec une grande précision. Un logiciel a été spécialement développé pour le contrôle de la navigation et le déclenchement des tirs de la source sismique en utilisant des récepteurs GPS différentiel (dGPS) sur le bateau et à l?extrémité de chaque flûte. Ceci permet de positionner les instruments avec une précision de l?ordre de 20 cm. Pour tester notre système, nous avons choisi une zone sur le Lac Léman, près de la ville de Lausanne, où passe la faille de « La Paudèze » qui sépare les unités de la Molasse du Plateau et de la Molasse Subalpine. Deux campagnes de mesures de sismique 3-D y ont été réalisées sur une zone d?environ 1 km2. Les enregistrements sismiques ont ensuite été traités pour les transformer en images interprétables. Nous avons appliqué une séquence de traitement 3-D spécialement adaptée à nos données, notamment en ce qui concerne le positionnement. Après traitement, les données font apparaître différents faciès sismiques principaux correspondant notamment aux sédiments lacustres (Holocène), aux sédiments glacio-lacustres (Pléistocène), à la Molasse du Plateau, à la Molasse Subalpine de la zone de faille et la Molasse Subalpine au sud de cette zone. La géométrie 3-D détaillée des failles est visible sur les sections sismiques verticales et horizontales. L?excellente qualité des données et l?interprétation de plusieurs horizons et surfaces de faille montrent le potentiel de cette technique pour les investigations à petite échelle en trois dimensions ce qui ouvre des voies à son application dans les domaines de l?environnement et du génie civil.

Linking the population genetics and ecology of arbuscular mycorrhizal fungi

Résumé Les champignons endomycorhiziens arbusculaires (CEA) ont co-évolué avec les plantes terrestres depuis plus de 400 millions d'années. De nos jours, les CEA forment une symbiose avec les racines de la majorité des plantes terrestres. Les CEA sont écologiquement importants parce qu'ils influencent non seulement la croissance des plantes, mais aussi leur diversité. Les CEA sont des biotrophes obligatoires qui reçoivent leur énergie sous forme de glucides issus de la photosynthèse des plantes. En contrepartie, les CEA apportent à leurs hôtes du phospore. Les CEA croissent et se reproduisent clonalement en formant des hyphes et des spores. De plus, les CEA sont coenocytiques et multigénomiques; le cytoplasme d'un CEA contient des noyeaux génétiquement différents. De nombreuses études ont démontré que différentes espèces de CEA agissent différentiellement sur la croissance des plantes. Malgré une conscience de plus en plus forte de l'existence d'une variabilité intraspécifique, la question de savoir si les populations de CEA sont génétiquement variables a été largement négligée. Dans le Chapitre 2, j'ai cherché à savoir si une population de CEA provenant d'un seul champ possède une diversité génétique. Cette étude a mis en évidence une importante variation génétique et phénotypique au sein d'individus de la même population. Des différences au niveau de traits de croissance, héritables et liés à la valeur sélective, indiquent que la variation génétique observée entre isolats n'est pas entièrement neutre. Dans le Chapitre 3, je montre que les différences génétiques entre isolats de CEA d'une population provoquent de la variation dans la croissance des plantes. L'effet des isolats dépend des conditions environnementales et varie de bénéfique à parasitique. Dans le Chapitre 4, je montre que des traits de croissance de CEA varient significativement dans des environnements contrastés. J'ai détecté de fortes interactions entre différents génotypes de CEA et différentes espèces de plantes. Ceci suggère que dans un environnement hétérogène, la sélection pourrait localement favoriser différents génotypes de CEA, maintenant ainsi la diversité génétique dans la population. Les résultats de ce travail aident à mieux comprendre l'importance écologique de la variation intraspécifique des CEA. La possibilité de pouvoir cultiver des individus d'une population de CEA au laboratoire nous a permis une meilleure compréhension de la génétique de ces champignons. De plus, ce travail est une base pour de futures expériences visant à comprendre l'importance évolutive de la diversité intraspécifique des CEA. Abstract Arbuscular mycorrhizal fungi (A1VIF) have co-evolved with land plants -for over 400 million years. Today, AMF form symbioses with roots of most land plants and are ecologically important because they alter plant growth and affect plant diversity. AMF are obligate biotrophs, obtaining their energy in form of plant-derived photosynthates. In return,- they supply their host plants with phosphorous. These fungi grow and reproduce clonally by hyphae and spores. They are coenocytic and multigenomic, harbouring genetically different nuclei in a common cytoplasm. Many studies have shown different AMF species differentially alter plant growth. Despite the increasing awareness of intraspecific variability the question whether there is any genetic variation among different individuals of the same population has been largely neglected. In Chapter 2, we investigated whether there is genetic diversity in a field population of the AMF G. intraradices. This work revealed that large genetic and heritable phenotypic variation exists in this AMF population. Differences in fitness-related growth traits among isolates suggest that some of the observed genetic variation is not selectively neutral. In Chapter 3, we show that genetic differences among isolates from the same population also cause variation in plant growth. The isolate effects on plant growth depended on the environmental conditions and varied from beneficial to detrimental. In Chapter 4, fitnessrelated growth traits of genetically different isolates were significantly altered in contrasting environments. we detected strong AMF isolate by host species interacfions which suggests that in a heterogeneous environment selection could locally favour different AMF genotypes, thereby maintaining high genetic diversity in the population. The results of this work contribute to the understanding of the ecological importance of intraspecific diversity in AMF. The possibility of culturing individuals of an AMF field population under laboratory condition gave new insights into AMF genetics and lays a foundation for future studies to analyse the evolutionary significance of intraspecific genetic diversity in AMF.

Electromagnetic Design of a Solid Steel Rotor Motor for Demanding Operation Environments

The solid-rotor induction motor provides a mechanically and thermally reliable solution for demanding environments where other rotor solutions are prohibited or questionable. Solid rotors, which are manufactured of single pieces of ferromagnetic material, are commonly used in motors in which the rotationspeeds exceed substantially the conventional speeds of laminated rotors with squirrel-cage. During the operation of a solid-rotor electrical machine, the rotor core forms a conductor for both the magnetic flux and the electrical current. This causes an increase in the rotor resistance and rotor leakage inductance, which essentially decreases the power factor and the efficiency of the machine. The electromagnetic problems related to the solid-rotor induction motor are mostly associated with the low performance of the rotor. Therefore, the main emphasis in this thesis is put on the solid steel rotor designs. The rotor designs studied in thisthesis are based on the fact that the rotor construction should be extremely robust and reliable to withstand the high mechanical stresses caused by the rotational velocity of the rotor. In addition, the demanding operation environment sets requirements for the applied materials because of the high temperatures and oxidizing acids, which may be present in the cooling fluid. Therefore, the solid rotors analyzed in this thesis are made of a single piece of ferromagnetic material without any additional parts, such as copper end-rings or a squirrel-cage. A pure solid rotor construction is rigid and able to keep its balance over a large speed range. It also may tolerate other environmental stresses such as corroding substances or abrasive particles. In this thesis, the main target is to improve the performance of an induction motor equipped with a solid steel rotor by traditional methods: by axial slitting of the rotor, by selecting a proper rotor core material and by coating the rotor with a high-resistive stainless ferromagnetic material. In the solid steel rotor calculation, the rotor end-effects have a significant effect on the rotor characteristics. Thus, the emphasis is also put on the comparison of different rotor endfactors. In addition, a corrective slip-dependent end-factor is proposed. The rotor designs covered in this thesis are the smooth solid rotor, the axially slitted solid rotor and the slitted rotor having a uniform ferromagnetic coating cylinder. The thesis aims at design rules for multi-megawatt machines. Typically, mega-watt-size solidrotor machines find their applications mainly in the field of electric-motor-gas-compression systems, in steam-turbine applications, and in various types of largepower pump applications, where high operational speeds are required. In this thesis, a 120 kW, 10 000 rpm solid-rotor induction motor is usedas a small-scale model for such megawatt-range solid-rotor machines. The performance of the 120 kW solid-rotor induction motors is determined by experimental measurements and finite element calculations.

Dyrk1A is dynamically expressed on subsets of motor neurons and in the neuromuscular junction: possible role in Down syndrome

Individuals with Down syndrome (DS) present important motor deficits that derive from altered motor development of infants and young children. DYRK1A, a candidate gene for DS abnormalities has been implicated in motor function due to its expression in motor nuclei in the adult brain, and its overexpression in DS mouse models leads to hyperactivity and altered motor learning. However, its precise role in the adult motor system, or its possible involvement in postnatal locomotor development has not yet been clarified. During the postnatal period we observed time-specific expression of Dyrk1A in discrete subsets of brainstem nuclei and spinal cord motor neurons. Interestingly, we describe for the first time the presence of Dyrk1A in the presynaptic terminal of the neuromuscular junctions and its axonal transport from the facial nucleus, suggesting a function for Dyrk1A in these structures. Relevant to DS, Dyrk1A overexpression in transgenic mice (TgDyrk1A) produces motor developmental alterations possibly contributing to DS motor phenotypes and modifies the numbers of motor cholinergic neurons, suggesting that the kinase may have a role in the development of the brainstem and spinal cord motor system.

N=1 SQCD-like theories with N_f massive flavors from AdS/CFT and beta functions

We study new supergravity solutions related to large-N c N=1 supersymmetric gauge field theories with a large number N f of massive flavors. We use a recently proposed framework based on configurations with N c color D5 branes and a distribution of N f flavor D5 branes, governed by a function N f S(r). Although the system admits many solutions, under plausible physical assumptions the relevant solution is uniquely determined for each value of x ≡ N f /N c . In the IR region, the solution smoothly approaches the deformed Maldacena-Núñez solution. In the UV region it approaches a linear dilaton solution. For x < 2 the gauge coupling β g function computed holographically is negative definite, in the UV approaching the NSVZ β function with anomalous dimension γ 0 = −1/2 (approaching − 3/(32π 2)(2N c  − N f )g 3)), and with β g  → −∞ in the IR. For x = 2, β g has a UV fixed point at strong coupling, suggesting the existence of an IR fixed point at a lower value of the coupling. We argue that the solutions with x > 2 describe a"Seiberg dual" picture where N f  − 2N c flips sign.

In situ spectroellipsometric study of the nucleation and growth of amorphous silicon

A detailed in situ spectroellipsometric analysis of the nucleation and growth of hydrogenated amorphous silicon (a:Si:H) is presented. Photoelectronic quality a‐Si:H films are deposited by plasma‐enhanced chemical vapor deposition on smooth metal (NiCr alloy) and crystalline silicon (c‐Si) substrates. The deposition of a‐Si:H is analyzed from the first monolayer up to a final thickness of 1.2 μm. In order to perform an improved analysis, real time ellipsometric trajectories are recorded, using fixed preparation conditions, at various photon energies ranging from 2.2 to 3.6 eV. The advantage of using such a spectroscopic experimental procedure is underlined. New insights into the nucleation and growth mechanisms of a‐Si:H are obtained. The nucleation mechanism on metal and c‐Si substrates is very accurately described assuming a columnar microstructural development during the early stage of the growth. Then, as a consequence of the incomplete coalescence of the initial nuclei, a surface roughness at the 10-15 Å scale is identified during the further growth of a‐Si:H on both substrates. The bulk a‐Si:H grows homogeneously beneath the surface roughness. Finally, an increase of the surface roughness is evidenced during the long term growth of a‐Si:H. However, the nature of the substrate influenced the film growth. In particular, the film thickness involved in the nucleation‐coalescence phase is found lower in the case of c‐Si (67±8 Å) as compared to NiCr (118±22 Å). Likewise films deposited on c‐Si present a smaller surface roughness even if thick samples are considered (>1 μm). More generally, the present study illustrates the capability of in situ spectroellipsometry to precisely analyze fundamental processes in thin‐film growth, but also to monitor the preparation of complex structures on a few monolayers scale.

Homonymous Ganglion Cell Layer Thinning After Isolated Occipital Lesion: Macular OCT Demonstrates Transsynaptic Retrograde Retinal Degeneration.

A 48-year-old man was examined 24 months after medial and surgical treatment of an isolated well-circumscribed right occipital lobe abscess. An asymptomatic residual left homonymous inferior scotoma was present. Fundus examination revealed temporal pallor of both optic discs, and optical coherence tomography (OCT) revealed mild temporal loss of retinal nerve fiber layer in both eyes. No relative afferent pupillary defect was present. Assessment of the retinal ganglion cell layer demonstrated homonymous thinning in a pattern corresponding to the homonymous visual field loss. There were no abnormalities of the lateral geniculate nuclei or optic tracts on review of the initial brain computed tomography and follow-up magnetic resonance imaging. We believe our patient showed evidence of transsynaptic retrograde degeneration after an isolated right occipital lobe lesion, and the homonymous neuronal loss was detected on OCT by assessing the retinal ganglion cell layer.

Reproductive morphology in Mediterranean Seirospora giraudyi (Ceramiales, Rhodophyta)

This paper presents a detailed description of the reproductive characters of Mediterranean Seirospora giraudyi based on fresh material collected in the northwestern coast of Spain. Vegetative cells are uninucleate. The plant is monoecious. Spermantangial parent’s cells are clustered on modified dwarf determinate filaments, usually situated on adaxial surfaces of branches. One to four spermatia are formed by elongation and proximal divisions of the spermatangial parent cells. Spermatium with a nucleus situated ina mec. The thallus is procarpic. The four-celled carpogonial branch is initially L-shaped, and it is situated on a periaxial supporting fertile axial cell. The mature carpogonial branch is U-shaped and the supporting cell and second periaxial cell enlarge and divide transversely to reproduce a pair uninicleate auxiliary cell. The nucleus in the ferlilized carpogonium divides twice and the carpogonium cleaves vertically into two cells that, turn, cut off a pair of uninucleate connecting cells that fuse with the auxiliary cells on opposite sides; the diploid nuclei in the connecting cells divide at the site of fusion and one of the nuclei enters the auxiliary cell white the other is extruded. Each auxiliary cell gives to a terminal primary gonimolobe initials. Gonimolobes form lax chains of carposporangia. As the gonimoblasts mature, both lobes of the foot cell which is situated on the supporting cell elongate the upper one secondary connecting with the supporting cell, and the lower one with the fertile axial cell. The gonimoblasts are subtended at maturity by one to several clusters of involucral flaments. Seirospora is currently placed in the tribe Euptiloteae; however the reproductive character of S.giraudyi is dentical to those described for the Cañllithamnieae. Molecular studies are needed to confirm the taxonomic position of S.giraudyi as well as that of the other species placed Seirospora

Aspects opératoires et péri-opératoires de la stimulation cérébrale profonde [Operative and perioperative aspects of deep brain stimulation].

La stimulation cérébrale profonde (SCP) nécessite l'implantation chirurgicale d'un système comprenant électrodes cérébrales et boîtier(s) de stimulation. Les noyaux cérébraux visés par la méthodologie stéréotaxique d'implantation doivent être visualisés au mieux par une imagerie à haute résolution. La procédure chirurgicale d'implantation des électrodes se fait si possible en anesthésie locale pour faire des mesures électro-physiologiques et tester en peropératoire l'effet de la stimulation, afin d'optimiser la position de l'électrode définitive. Dans un deuxième temps, le ou les générateur(s) d'impulsions sont implantés en anesthésie générale. La SCP pour les mouvements anormaux a une très bonne efficacité et un risque de complications graves faible quoique non nul. Les complications liées au matériel sont les plus fréquentes. Deep brain stimulation (DBS) requires the surgical implantation of a system including brain electrodes and impulsion generator(s). The nuclei targeted by the stereotaxic implantation methodology have to be visualized at best by high resolution imaging. The surgical procedure for implanting the electrodes is performed if possible under local anaesthesia to make electro-physiological measurements and to test intra-operatively the effect of the stimulation, in order to optimize the position of the definitive electrode. In a second step, the impulsion generator(s) are implanted under general anaesthesia. DBS for movement disorders has a very good efficacy and a low albeit non-zero risk of serious complications. Complications related to the material are the most common.

Neutron skin thickness in the droplet model with surface width dependence: Indications of softness of the nuclear symmetry energy

We analyze the neutron skin thickness in finite nuclei with the droplet model and effective nuclear interactions. The ratio of the bulk symmetry energy J to the so-called surface stiffness coefficient Q has in the droplet model a prominent role in driving the size of neutron skins. We present a correlation between the density derivative of the nuclear symmetry energy at saturation and the J/Q ratio. We emphasize the role of the surface widths of the neutron and proton density profiles in the calculation of the neutron skin thickness when one uses realistic mean-field effective interactions. Next, taking as experimental baseline the neutron skin sizes measured in 26 antiprotonic atoms along the mass table, we explore constraints arising from neutron skins on the value of the J/Q ratio. The results favor a relatively soft symmetry energy at subsaturation densities. Our predictions are compared with the recent constraints derived from other experimental observables. Though the various extractions predict different ranges of values, one finds a narrow window L∼45-75 MeV for the coefficient L that characterizes the density derivative of the symmetry energy that is compatible with all the different empirical indications.

From Full stopping to transparency in a holographic model of heavy ion collisions

We numerically simulate planar shock wave collisions in anti-de Sitter space as a model for heavy ion collisions of large nuclei. We uncover a crossover between two different dynamical regimes as a function of the collision energy. At low energies the shocks first stop and then explode in a manner approximately described by hydrodynamics, in close similarity with the Landau model. At high energies the receding fragments move outwards at the speed of light, with a region of negative energy density and negative longitudinal pressure trailing behind them. The rapidity distribution of the energy density at late times around midrapidity is not approximately boost invariant but Gaussian, albeit with a width that increases with the collision energy.

The existence of FGFR1-5-HT1A receptor heterocomplexes in midbrain 5-HT neurons of the rat: relevance for neuroplasticity

The ascending midbrain 5-HT neurons to the forebrain may be dysregulated in depression and have a reduced trophic support. With in situ proximity ligation assay (PLA) and supported by coimmunoprecipitation and colocation of the FGFR1 and 5-HT1A immunoreactivities in the midbrain raphe cells, evidence for the existence of FGFR1-5-HT1A receptor heterocomplexes in the dorsal and median raphe nuclei of the Sprague Dawley rat as well as in the rat medullary raphe RN33B cells has been obtained. Especially after combined FGF-2 and 8-OH-DPAT treatment, a marked and significant increase in PLA clusters was found in the RN33B cells. Similar results were reached with the FRET technique in HEK293T cells, where TM-V of the 5HT1A receptor was found to be part of the receptor interface. The combined treatment with FGF-2 and the 5-HT1A agonist also synergistically increased FGFR1 and ERK1/2 phosphorylation in the raphe midline area of the midbrain and the RN33B cells as well as their differentiation, as seen from development of the increased number and length of extensions per cell and their increased 5-HT immunoreactivity. These signaling and differentiation events were dependent on the receptor interface since they were blocked by incubation with TM-V but not by TM-II. Together, the results indicate that the 5-HT1A autoreceptors by being part of a FGFR1-5-HT1A receptor heterocomplex in the midbrain raphe 5-HT nerve cells appear to have a trophic role in the central 5-HT neuron systems in addition to playing a key role in reducing the firing of these neurons

Nuclear DNA content variation in life history phases of the Bonnemaisoniaceae (Rhodophyta)

Nuclear DNA content in gametophytes and sporophytes or the prostrate phases of the following species of Bonnemaisoniaceae (Asparagopsis armata, Asparagopsis taxiformis, Bonnemaisonia asparagoides, Bonnemaisonia clavata and Bonnemaisonia hamifera) were estimated by image analysis and static microspectrophotometry using the DNA-localizing fluorochrome DAPI (4′, 6-diamidino-2-phenylindole, dilactate) and the chicken erythrocytes standard. These estimates expand on the Kew database of DNA nuclear content. DNA content values for 1C nuclei in the gametophytes (spermatia and vegetative cells) range from 0.5 pg to 0.8 pg, and for 2C nuclei in the sporophytes or the prostrate phases range from 1.15-1.7 pg. Although only the 2C and 4C values were observed in the sporophyte or the prostrate phase, in the vegetative cells of the gametophyte the values oscillated from 1C to 4C, showing the possible start of endopolyploidy. The results confirm the alternation of nuclear phases in these Bonnemaisoniaceae species, in those that have tetrasporogenesis, as well as those that have somatic meiosis. The availability of a consensus phylogenetic tree for Bonnemaisoniaceae has opened the way to determine evolutionary trends in DNA contents. Both the estimated genome sizes and the published chromosome numbers for Bonnemaisoniaceae suggest a narrow range of values consistent with the conservation of an ancestral genome.