A prospective randomised double-blind controlled trial evaluating the effect of trans-sacral magnetic stimulation in women with overactive bladder.

Overactive bladder (OAB) is a prevalent condition with 16% of adults having one or more symptoms that significantly affect quality of life. Transcutaneous electrical nerve stimulation and neuromodulators have had success in treating OAB but are expensive, invasive, and sometimes cumbersome. We developed an alternative neuromodulatory technique that involves electromagnetic stimulation of the sacral nerve roots with a portable electromagnetic device to produce trans-sacral stimulation of the S3 and S4 sacral nerve roots. The aim of this study was to evaluate the impact of this device on OAB symptoms in women with a prospectively randomised double-blind controlled study. Following a power analysis, women with symptoms of OAB were prospectively recruited with ethical approval for randomisation to an active treatment (n = 33) or placebo group (n = 30) in a double-blind trial. The patient, at home, used the belt device daily for 20 min over 12 weeks. Outcome measures included a 3-day voiding diary, 1 h pad test, visual analogue score (VAS) for symptom impact (0-100%), Kings Health Questionnaire (KHQ) and Australian Quality of Life questionnaire (AQOL) at baseline, 6 and 12 weeks. Overall, no difference was found between groups for any of the research questions. Specifically, we were unable to demonstrate any difference between the active and sham device groups in frequency, nocturia, urinary leakage, or quality of life, nor was there any evidence of a placebo effect. The quality of the data was high with the number of missing observations (especially for disease specific KHQ and general AQOL) being few. This attempt to promote trans-sacral electromagnetic neuromodulation with a specially created device was ineffective on the symptoms of OAB.

Tectonics of the Simplon massif and Lepontine gneiss dome: deformation structures due to collision between the underthrusting European plate and the Adriatic indenter

this study presents a review of published geological data, combined with original observations on the tectonics of the simplon massif and the Lepontine gneiss dome in the Western Alps. New observations concern the geometry of the Oligocene Vanzone back fold, formed under amphibolite facies conditions, and of its root between Domodossola and Locarno, which is cut at an acute angle by the Miocene, epi- to anchizonal, dextral centovalli strike-slip fault. the structures of the simplon massif result from collision over 50 Ma between two plate boundaries with a different geometry: the underthrusted European plate and the Adriatic indenter. Detailed mapping and analysis of a complex structural interference pattern, combined with observations on the metamorphic grade of the superimposed structures and radiometric data, allow a kinematic model to be developed for this zone of oblique continental collision. the following main Alpine tectonic phases and structures may be distinguished: 1. NW-directed nappe emplacement, starting in the Early Eocene (similar to 50 Ma); 2. W, SW and S- verging transverse folds; 3. transpressional movements on the dextral simplon ductile shear zone since similar to 32 Ma; 4. formation of the Bergell - Vanzone backfolds and of the southern steep belt during the Oligocene, emplacement of the mantle derived 31 - 29 Ma Bergell and Biella granodiorites and porphyritic andesites as well as intrusions of 29-25 Ma crustal aplites and pegmatites; 5. formation of the dextral discrete Rhone-Simplon line and the centovalli line during the Miocene, accompanied by the pull-apart development of the Lepontine gneiss dome - Dent blanche (Valpelline) depression. It is suggested that movements of shortening in fan shaped NW, W and sW directions accompanied the more regular NW- to WNW-directed displacement of the Adriatic indenter during continental collision.

Carbon and oxygen isotope study of hydrothermal carbonates in the zinc-lead deposits of the San Vicente district, central Peru: A quantitative modeling on mixing processes and CO2 degassing

Carbon and oxygen isotope studies of the host and gangue carbonates of Mississippi Valley-type zinc-lead deposits in the San Vicente District hosted in the Upper Triassic to Lower Jurassic dolostones of the Pucara basin (central Peru) were used to constrain models of the ore formation. A mixing model between an incoming hot saline slightly acidic radiogenic (Pb, Sr) fluid and the native formation water explains the overall isotopic variation (delta(13)C = - 11.5 to + 2.5 parts per thousand relative to PDB and delta(18)O = + 18.0 to + 24.3 parts per thousand relative to SMOW) of the carbonate generations. The dolomites formed during the main ore stage show a narrower range (delta(13)C = - 0.1 to + 1.7 parts per thousand and delta(18)O = + 18.7 to + 23.4 parts per thousand) which is explained by exchange between the mineralizing fluids and the host carbonates combined with changes in temperature and pressure. This model of fluid-rock interaction explains the pervasive alteration of the host dolomite I and precipitation of sphalerite I. The open-space filling hydrothermal white sparry dolomite and the coexisting sphalerite II formed by prolonged fluid-host dolomite interaction and limited CO2 degassing. Late void-filling dolomite III (or calcite) and the associated sphalerite III formed as the consequence of CO2 degassing and concomitant pH increase of a slightly acidic ore fluid. Widespread brecciation is associated to CO2 outgassing. Consequently, pressure variability plays a major role in the ore precipitation during the late hydrothermal events in San Vicente. The presence of native sulfur associated with extremely carbon-light calcites replacing evaporitic sulfates (e.g., delta(13)C = - 11.5 parts per thousand), altered native organic matter and heavier hydrothermal bitumen (from - 27.0 to - 23.0 parts per thousand delta(13)C) points to thermochemical reduction of sulfate and/or thiosulfate. The delta(13)C- and delta(18)O-values of the altered host dolostone and hydrothermal carbonates, and the carbon isotope composition of the associated organic matter show a strong regional homogeneity. These results coupled with the strong mineralogical and petrographic similarities of the different MVT occurrences perhaps reflects the fact that the mineralizing processes were similar in the whole San Vicente belt, suggesting the existence of a common regional mineralizing hydrothermal system with interconnected plumbing.

Late Pan-African magmatism in the Himalaya: new geochronological and geochemical data from the Ordovician Tso Morari metagranites (Ladakh, NW India)

Two granitic plutons, the Tso Morari gneiss and the Rupshu metagranite, crop out in the Tso Morari area. The Polokongka La granite, classically interpreted as a young intrusion in the Tso Morari gneiss, has been recognized as the undeformed facies of the latter. Conventional isotope dilution U-Pb zircon dating on single-grain and small multi-grain fractions yielded magmatic ages of 479 +/- 2 Ma for the Tso Morari gneiss and the Polokongka La granite, and 482.5 +/- 1 Ma for the Rupshu granite. There is a great difference in zircon morphology between the Tso Morari gneiss (peraluminous type) and the Rupshu granite (alkaline type). This difference is confirmed by whole-rock chemistry. The Tso Morari gneiss is a typical deformed S-type granite, resulting from crustal anatexis. On the other hand, the Rupshu granite is an essentially metaluminous alkali-calcic intrusion derived from a different source material. Data compilation from other Himalayan Cambro-Ordovician granites reveals huge and widespread magmatic activity all along and beyond the northern Indian plate between 570 and 450 Ma, with a peak at 500-480 Ma. A major, continental-scale tectonic event is required to generate such a large magmatic belt; it has been tentatively compared to the Variscan post-orogenic extensional regime of Western Europe, as a late evolution stage of a Pan-African orogenic event.

Discovery of an albite gneiss from the Ile de Groix (Armorican Massif, France): Geochemistry and LA-ICP-MS U-Pb geochronology of its Ordovician protolith

For the first time, an albite orthogneiss has been recognised and dated within the HP-LT blueschist facies metabasites and metapelites of the Ile de Groix. It is characterised by a peraluminous composition, high LILE, Th and U contents, MORB-like HREE abundances and moderate Nb and Y values. A U-Pb age of 480.8 +/- A 4.8 Ma was obtained by LA-ICP-MS dating of zircon and titanite. It is interpreted as the age of the magmatic emplacement during the Early Ordovician. Morphologically different zircon grains yield late Neoproterozoic ages of 546.6-647.4 Ma. Zircon and titanite U-Pb ages indicate that the felsic magmatism from the Ile de Groix is contemporaneous with the acid, pre-orogenic magmatism widely recognised in the internal zones of the Variscan belt, related to the Cambro-Ordovician continental rifting. The magmatic protolith probably inherited a specific chemical composition from a combination of orogenic, back-arc and anorogenic signatures because of partial melting of the Cadomian basement during magma emplacement. Besides, the late Devonian U-Pb age of 366 +/- A 33 Ma obtained for titanite from a blueschist facies metapelite corresponds to the age of the HP-LT peak metamorphism.

Subalpine-nival gradient of species richness for vascular plants, lichens and bryophytes in the Swiss Inner Alps

In the European GLORIA project, 12 summits (treeline to nival belt) were inventoried in three regions of Switzerland: two in the Swiss National Park Graubünden and one in Valais. Vascular plants were recorded in all three regions and bryophytes and lichens were recorded only in Valais. On each summit, vegetation and temperature data were sampled using sampling protocols for the GLORIA project (Global Observation Research Initiative in Alpine environment) on large summit sections and in clusters of four 1x1-m quadrats. We observed a general decrease of species richness for all three systematic groups with increasing elevation in the summit sections, but only for vascular plants in the quadrats. In Valais, there was higher species richness for vascular plants than for bryophytes and lichens on the lower summits, but as the decrease in species richness was less pronounced for cryptogams, the latter were more numerous than vascular plants on the highest summit. Vascular species showed a clear shift of the dominant life form with elevation, with chamaephytes replacing hemicryptophytes. Bryophytes and lichens showed a weak trend among the life forms at the summit section scale, but a stronger shift of the dominant forms was seen in the quadrats, with cushion replacing turf bryophytes and crustaceous replacing fruticose lichens. Altogether, these results sustain the temperature-physiographic hypothesis to explain the species richness decrease along the altitudinal gradient: the harsh climatic conditions of the alpine-nival belts act as a filter for species, but the diminishing diversity of microhabitats is also an important factor. Because cryptogams depend more on humidity than temperature and more on smaller microhabitats than vascular plants, the decrease of species richness is more gradual with elevation for bryophytes and lichens.

The abrupt climate change at the Eocene-Oligocene boundary and the emergence of South-East Asia triggered the spread of sapindaceous lineages.

Background and Aims Paleoclimatic data indicate that an abrupt climate change occurred at the Eocene-Oligocene (E-O) boundary affecting the distribution of tropical forests on Earth. The same period has seen the emergence of South-East (SE) Asia, caused by the collision of the Eurasian and Australian plates. How the combination of these climatic and geomorphological factors affected the spatio-temporal history of angiosperms is little known. This topic is investigated by using the worldwide sapindaceous clade as a case study. Methods Analyses of divergence time inference, diversification and biogeography (constrained by paleogeography) are applied to a combined plastid and nuclear DNA sequence data set. Biogeographical and diversification analyses are performed over a set of trees to take phylogenetic and dating uncertainty into account. Results are analysed in the context of past climatic fluctuations. Key Results An increase in the number of dispersal events at the E-O boundary is recorded, which intensified during the Miocene. This pattern is associated with a higher rate in the emergence of new genera. These results are discussed in light of the geomorphological importance of SE Asia, which acted as a tropical bridge allowing multiple contacts between areas and additional speciation across landmasses derived from Laurasia and Gondwana. Conclusions This study demonstrates the importance of the combined effect of geomorphological (the emergence of most islands in SE Asia approx. 30 million years ago) and climatic (the dramatic E-O climate change that shifted the tropical belt and reduced sea levels) factors in shaping species distribution within the sapindaceous clade.

Detrital zircon and micropalaeontological ages as new constraints for the lowermost tectonic unit (Talea Ori unit) of Crete, Greece

The Talea Ori unit is the lowermost known tectonic unit of Crete and the most external part of the Hellenides. Its stratigraphy ranges from Late Carboniferous to Oligocene and outcrops of the lower part are only known in the Talea Ori mountains (central Crete). In this area, a black sandstone at the base of the Galinos Beds, thought to be the oldest formation, contains zircons which were dated using the single grain evaporation method. The majority of these grains yielded Late Carboniferous ages (Variscan), while a small group yielded Early Proterozoic ages. The age distribution of these zircons suggests that, at the Carboniferous-Permian boundary, not much of the older North Gondwanan basement was exposed and that a river system carried detrital material from the Variscan belt towards the forming Neotethyan rift. Additionally, higher up in the stratigraphy benthic foraminifers (miliolids) were found in clasts from a conglomerate which was so far thought to be of Early Triassic age [Epting, M., Kudrass, H.-R., Leppig, U., Schaffer, A., 1972. Geologie der Talea Ori/Kreta. N. Jb. Geol. Palaont. Abh. 141, 259-285.]. These miliolids belong to the species Hoyenella inconstans [Michalik, J., Jendrejakova, O., Borza, K., 1979. Some new foraminifera species of the Fatra-Formation (Uppermost Triassic) in the West Carpathians. Geol. Carpath. 30 (1), 61-91.], thus attributing a Late Triassic (Carnian-Norian?) maximal age to this conglomerate. The carbonate platform from which the miliolids-bearing clasts come is not known. The presence to the north of a continuous hemipelagic record from the Carboniferous to the Triassic (Phyllite-Quartzite and Tripali units), attributed to the Palaeotethys realm, allows the Talea Ori unit and its lateral equivalents (the Ionian zone) to be assigned to the westward continuation of the Cimmerian block and therefore to the northern margin of the East Mediterranean Neotethys ocean. (c) 2006 Elsevier B.V. All rights reserved.

Alpine and pre-Alpine magmatism in the root-zone of the western Central Alps

The highest grade of metamorphism and associated structural elements in orogenic belts may be inherited from earlier orogenic events. We illustrate this point using magmatic and metamorphic rocks from the southern steep belt of the Lepontine Gneiss Dome (Central Alps). The U-Pb zircon ages from an anatectic granite at Verampio and migmatites at Corcapolo and Lavertezzo yield 280-290 Ma, i.e., Hercynian ages. These ages indicate that the highest grade of metamorphism in several crystalline nappes of the Lepontine Gneiss Dome is pre-Alpine. Alpine metamorphism reached sufficiently high grade to reset the Rb-Sr and K-Ar systematics of mica and amphibole, but generally did not result in crustal melting, except in the steep belt to the north of the Insubric Line, where numerous 29 to 26 Ma old pegmatites and aplites had intruded syn- and post-kinematically into gneisses of the ductile Simplon Shear Zone. The emplacement age of these pegmatites gives a minimum estimate for the age of the Alpine metamorphic peak in the Monte Rosa nappe. The U-Pb titanite ages of 33 to 31 Ma from felsic porphyritic veins represent a minimum-age estimate for Alpine metamorphism in the Sesia Zone. A porphyric vein emplaced at 448 +/- 5 Ma (U-Pb monazite) demonstrates that there existed a consolidated Caledonian basement in the Sesia Zone.

Multisensory anatomical pathways.

In order to interact with the multisensory world that surrounds us, we must integrate various sources of sensory information (vision, hearing, touch...). A fundamental question is thus how the brain integrates the separate elements of an object defined by several sensory components to form a unified percept. The superior colliculus was the main model for studying multisensory integration. At the cortical level, until recently, multisensory integration appeared to be a characteristic attributed to high-level association regions. First, we describe recently observed direct cortico-cortical connections between different sensory cortical areas in the non-human primate and discuss the potential role of these connections. Then, we show that the projections between different sensory and motor cortical areas and the thalamus enabled us to highlight the existence of thalamic nuclei that, by their connections, may represent an alternative pathway for information transfer between different sensory and/or motor cortical areas. The thalamus is in position to allow a faster transfer and even an integration of information across modalities. Finally, we discuss the role of these non-specific connections regarding behavioral evidence in the monkey and recent electrophysiological evidence in the primary cortical sensory areas.

Plate tectonics of the Altaids

Abstract: The Altaids consist in a huge accretionary-type belt extending from Siberia through Mon-golia, northern China, Kyrgyzstan and Kazakhstan. They were formed from the Vendian through the Jurassic by the accretion of numerous displaced and exotic terranes (e.g. island arc, ribbon microcontinent, seamount, basaltic plateau, back-arc basin). The number, nature and origin of the terranes differ according to the palaeotectonic models of the different authors. Thanks to a geo- dynamic study (i.e. definition of tectonic settings and elaboration of geodynamic scenarios) and plate tectonics modelling, this work aims to present an alternative model explaining the Palaeozoic palaeotectonic evolution of the Altaids. Based on a large set of compiled geological data related to palaeogeography and geodyna¬mic (e.g. sedimentology, stratigraphy, palaeobiogeography, palaeomagnetism, magmatism, me- tamorphism, tectonic...), a partly new classification of the terranes and sutures implicated in the formation of the Altaids is proposed. In the aim to elaborate plate tectonics reconstructions, it is necessary to fragment the present arrangement of continents into consistent geological units. To avoid confusion with existing terminology (e.g. tectonic units, tectono-stratigraphic units, micro- continents, terranes, blocks...), the new concept of "Geodynamic Units (GDU)" was introduced. A terrane may be formed by a set of GDUs. It consists of a continental and/or oceanic fragment which has its own kinematic and geodynamic evolution for a given period. With the same ap-proach, the life span and type of the disappeared oceans is inferred thanks to the study of the mate-rial contained in suture zones. The interpretation of the tectonic settings within the GDUs comple-ted by the restoration of oceans leads to the elaboration of geodynamic scenarios. Since the Wilson cycle was presented in 1967, numerous works demonstrated that the continental growth is more complex and results from diverse geodynamic scenarios. The identification of these scenarios and their exploitation enable to elaborate plate tectonics models. The models are self-constraining (i.e. space and time constraints) and contest or confirm in turn the geodynamic scenarios which were initially proposed. The Altaids can be divided into three domains: (1) the Peri-Siberian, (2) the Kazakhstan, and (3) the Tarim-North China domains. The Peri-Siberian Domain consists of displaced (i.e. Sayan Terrane Tuva-Mongolian, Lake-Khamsara Terrane) and exotic terranes (i.e. Altai-Mongolian and Khangai-Argunsky Terrane) accreted to Siberia from the Vendian through the Ordovician. Fol-lowing the accretion of these terranes, the newly formed Siberia active margin remained active un-til its part collision with the Kazakhstan Superterrane in the Carboniferous. The eastern part of the active margin (i.e. East Mongolia) continued to act until the Permian when the North-China Tarim Superterrane collided with it. The geodynamic evolution of the eastern part of the Peri-Siberian Domain (i.e. Eastern Mongolia and Siberia) is complicated by the opening of the Mongol-Okhotsk Ocean in the Silurian. The Kazakhstan Domain is composed of several continental terranes of East Gondwana origin amalgamated together during the Ordovician-Silurian time. After these different orogenic events, the Kazakhstan Superterrane evolved as a single superterrane until its collision with a Tarim-North China related-terrane (i.e. Tianshan-Hanshan Terrane) and Siberian Continent during the Devonian. This new organisation of the continents imply a continued active margin from Siberia, to North China through the Kazakhstan Superterrane and the closure of the Junggar- Balkash Ocean which implied the oroclinal bending of the Kazakhstan Superterrane during the entire Carboniferous. The formation history of the Tarim-North China Domain is less complex. The Cambrian northern passive margin became active in the Ordovician. In the Silurian, the South Tianshan back-arc Ocean was open and led to the formation of the Tianshan-Hanshan Terrane which collided with the Kazakhstan Superterrane during the Devonian. The collision between Siberia and the eastern part of the Tarim-North China continents (i.e. Inner Mongolia), implied by the closure of the Solonker Ocean, took place in the Permian. Since this time, the major part of the Altaids was formed, the Mongol-Okhotsk Ocean only was still open and closed during the Jurassic. Résumé: La chaîne des Altaïdes est une importante chaîne d'accrétion qui s'étend en Sibérie, Mon-golie, Chine du Nord, Kirghizstan et Kazakhstan. Elle s'est formée durant la période du Vendian au Jurassique par l'accrétion de nombreux terranes déplacés ou exotiques (par exemple arc océa-nique, microcontinent, guyot, plateau basaltique, basin d'arrière-arc...). Le nombre, la nature ou encore l'origine diffèrent selon les modèles paléo-tectoniques proposés par les différents auteurs. Grâce à une étude géodynamique (c'est-à-dire définition des environnements tectoniques et éla-boration de scénarios géodynamiques) et à la modélisation de la tectonique des plaques, ce travail propose un modèle alternatif expliquant l'évolution paléo-tectonique des Altaïdes. Basé sur une large compilation de données géologiques pertinentes en termes de paléo-géographie et de géodynamique (par exemple sédimentologie, stratigraphie, paléo-biogéographie, paléomagnétisme, magmatisme, métamorphisme, tectonique...), une nouvelle classification des terranes et des sutures impliqués dans la formation des Altaïdes est proposée. Dans le but d'élabo¬rer des reconstructions de plaques tectoniques, il est nécessaire de fragmenter l'arrangement actuel des continents en unités tectoniques cohérentes. Afin d'éviter les confusions avec la terminolo¬gie existante (par exemple unité tectonique, unité tectono-stratigraphique, microcontinent, block, terrane...), le nouveau concept d' "Unité Géodynamique (UGD)" a été introduit. Un terrane est formé d'une ou plusieurs UGD et représente un fragment océanique ou continental défini pas sa propre cinétique et évolution géodynamique pour une période donnée. Parallèlement, la durée de vie et le type des océans disparus (c'est-à-dire principal ou secondaire) est déduite grâce à l'étude du matériel contenu dans les zones de sutures. L'interprétation des environnements tectoniques des UGD associés à la restauration des océans mène à l'élaboration de scénarios géodynamiques. Depuis que le Cycle de Wilson a été présenté en 1967, de nombreux travaux ont démontré que la croissance continentale peut résulter de divers scénarios géodynamiques. L'identification et l'ex-ploitation de ces scénarios permet finalement l'élaboration de modèles de tectonique des plaques. Les modèles sont auto-contraignants (c'est-à-dire contraintes spatiales et temporelles) et peuvent soit contester ou confirmer les scénarios géodynamiques initialement proposés. Les Altaïdes peuvent être divisées en trois domaines : (1) le Domaine Péri-Sibérien, (2) le Domaine Kazakh, et (3) le Domaine Tarim-Nord Chinois. Le Domaine Péri-Sibérien est composé de terranes déplacés (c'est-à-dire Terrane du Sayan, Tuva-Mongol et Lake-Khamsara) et exotiques (c'est-à-dire Terrane Altai-Mongol et Khangai-Argunsky) qui ont été accrétés au craton Sibérien durant la période du Vendien à l'Ordovicien. Suite à l'accrétion de ces terranes, la marge sud-est de la Sibérie nouvellement formée reste active jusqu'à sa collision partielle avec le Superterrane Ka-zakh au Carbonifère. La partie est de la marge active (c'est-à-dire Mongolie de l'est) continue son activité jusqu'au Permien lors de sa collision avec le Superterrane Tarim-Nord Chinois. L'évolu¬tion géodynamique de la partie est du Domaine Sibérien est compliquée par l'ouverture Silurienne de l'Océan Mongol-Okhotsk qui disparaîtra seulement au Jurassique. Le Domaine Kazakh est composé de plusieurs terranes d'origine est-Gondwanienne accrétés les uns avec les autres avant ou pendant le Silurien inférieur et leurs evolution successive sous la forme d'un seul superterrane. Le Superterrane Kazakh collisione avec un terrane Tarim-Nord Chinois (c'est-à-dire Terrane du Tianshan-Hanshan) durant le Dévonien et le continent Sibérien au Dévonien supérieur. Ce nouvel agencement des plaques induit une marge active continue le long des continents Sibérien, Kazakh et Nord Chinois et la fermeture de l'Océan Junggar-Balkash qui provoque le plissement oroclinal du Superterrane Kazakh durant le Carbonifère. L'histoire de la formation du Domaine Tarim-Nord Chinois est moins complexe. La marge passive nord Cambrienne devient active à l'Ordovicien et l'ouverture Silurienne du bassin d'arrière-arc du Tianshan sud mène à la formation du terrane du Tianshan-Hanshan. La collision Dévonienne entre ce dernier et le Superterrane Kazakh provoque la fermerture de l'Océan Tianshan sud. Finalement, la collision entre la Sibérie et la partie est du continent Tarim-Nord Chinois (c'est-à-dire Mongolie Intérieure) prend place durant le Permien suite à la fermeture de l'Océan Solonker. La majeure partie des Altaïdes est alors formée, seul l'Océan Mongol-Okhotsk est encore ouvert. Ce dernier se fermera seulement au Jurassique.

Stratigraphie, morphodynamique, paléoenvironnements des terrains sédimentaires meubles à forte déclivité du domaine périglaciaire alpin

Dans le contexte d'un climat de plus en plus chaud, une étude « géosystémique » de la répartition du pergélisol dans l'ensemble d'un versant périglaciaire alpin, de la paroi rocheuse jusqu'au glacier rocheux, s'avère primordiale. S'insérant dans cette problématique, ce travail de thèse vise comme objectif général l'étude des versants d'éboulis situés à l'intérieur de la ceinture du pergélisol discontinu selon deux volets de recherche différents : une étude de la stratigraphie et de la répartition du pergélisol dans les éboulis de haute altitude et des processus qui lui sont associés ; une reconstitution de l'histoire paléoenvironnementale du domaine périglaciaire alpin pendant le Tardiglaciaire et l'Holocène. La stratigraphie et la répartition spatiale du pergélisol a été étudiée dans cinq éboulis des Alpes Valaisannes (Suisse), dont trois ont fait l'objet de forages profonds, grâce à la prospection géophysique de détail effectuée à l'aide de méthodes thermiques, de résistivité, sismiques et nucléaires. Les mesures effectuées ont permis de mettre en évidence que, dans les cinq éboulis étudiés, la répartition du pergélisol est discontinue et aucun des versants n'est intégralement occupé par du pergélisol. En particulier, il a été possible de prouver de manière directe que, dans un éboulis, le pergélisol est présent dans les parties inférieures du versant et absent dans les parties supérieures. Trois facteurs de contrôle principaux de la répartition du pergélisol déterminée au sein des éboulis étudiés ont été individualisés, pouvant agir seuls ou de manière combinée : la ventilation ascendante, l'augmentation de la granulométrie en direction de l'aval et la redistribution de la neige par le vent et les avalanches. Parmi ceux-ci, la relation ventilation-granulométrie semble être le facteur de contrôle principal permettant d'expliquer la présence de pergélisol dans les parties inférieures d'un éboulis et son absence dans les parties supérieures. Enfin, l'analyse de la structure des éboulis périglaciaires de haute altitude a permis de montrer que la stratigraphie du pergélisol peut être un élément important pour l'interprétation de la signification paléoclimatique de ce type de formes. Pour le deuxième volet de la recherche, grâce aux datations relatives effectuées à l'aide de l'utilisation conjointe de la méthode paléogéographique et du marteau de Schmidt, il a été possible de définir la chrono-stratigraphie du retrait glaciaire et du développement des glaciers rocheux et des versants d'éboulis des quatre régions des Alpes suisses étudiées (régions du Mont Gelé - Mont Fort, des Fontanesses et de Chamosentse, dans les Alpes Valaisannes, et Massif de la Cima di Gana Bianca, dans les Alpes Tessinoises). La compilation de toutes les datations effectuées a permis de montrer que la plupart des glaciers rocheux actifs étudiés se seraient développés soit juste avant et/ou pendant l'Optimum Climatique Holocène de 9.5-6.3 ka cal BP, soit au plus tard juste après cet évènement climatique majeur du dernier interglaciaire. Parmi les glaciers rocheux fossiles datés, la plupart aurait commencé à se former dans la deuxième moitié du Tardiglaciaire et se serait inactivé dans la première partie de l'Optimum Climatique Holocène. Pour les éboulis étudiés, les datations effectuées ont permis d'observer que leur surface date de la période entre le Boréal et l'Atlantique récent, indiquant que les taux d'éboulisation après la fin de l'Optimum Climatique Holocène ont dû être faibles, et que l'intervalle entre l'âge maximal et l'âge minimal est dans la plupart des cas relativement court (4-6 millénaires), indiquant que les taux d'éboulisation durant la période de formation des éboulis ont dû être importants. Grâce au calcul des taux d'érosion des parois rocheuses sur la base du volume de matériaux rocheux pour quatre des éboulis étudiés, il a été possible mettre en évidence l'existence d'une « éboulisation parapériglaciaire » liée à la dégradation du pergélisol dans les parois rocheuses, fonctionnant principalement durant les périodes de réchauffement climatique rapide comme cela a été le cas au début du Bølling, du Préboréal à la fin de l'Atlantique récent et, peut-être, à partir des années 1980. - In the context of a warmer climate, a « geosystemical » study of the permafrost distribution in a whole alpine periglacial hillslope, from the rockwall to the rockglacier, is of great importance. With respect to this problem, the general objective of this PhD thesis is the global study of talus slopes located within the alpine periglacial belt following two different research axes: the analysis of the internal structure and of the permafrost distribution of high altitude talus slopes and of the related processes; the reconstruction of the palaeoenvironmental history of the alpine periglacial belt during the Lateglacial and the Holocene. The stratigraphy and the permafrost distribution were studied in five talus slopes of the Valais Alps (Switzerland) with the analysis of borehole data (on three of the five talus slopes) and other methods of permafrost prospecting: Electrical Resistivity Tomography (ERT), Refraction Seismic Tomography (RST) and nuclear well logging. The collected data shows that, in all of the studied talus slopes, permafrost distribution is discontinuous and that neither of the hillslopes is integrally characterised by permafrost. In particular, this data proves by direct investigations that, in talus slopes, permafrost is present in the lower parts of the hillslope, whereas it is absent in the upper parts. Permafrost distribution in alpine talus slopes is depending of the combination of almost three controlling factors, whose respective importance is variable: the chimney effect, the increase of grain size downslope and the redistribution of snow by avalanches. Depending on the size of the talus and on topographical and geomorphological heterogeneities, various cases are possible: one dominant controlling factor or the combination of various factors. Nevertheless, it would be an error to consider each controlling factor independently, without considering their relationships. Between these controlling factors, the relationship chimney effect/grain size seems to be the most important factor controlling the presence of permafrost in the lowest part of periglacial talus slopes, and its absence in the upper parts. Finally, the analysis of the talus structure shows that the permafrost stratigraphy may be an important element of interpretation of the palaeoclimatic significance of an alpine talus slope. The second research axe focused on the establishment of a chronology of the Lateglacial glacier retreat and the dating of rockglaciers and talus slopes development in four studied regions of the Swiss Alps (Mont Gelé - Mont Fort, Fontanesses and Chamosentse regions, in the Valais Alps, and the Cima di Gana Bianca Massif, in the Ticino Alps). The compilation of the dates acquired through the combination of the palaeogeographical method and of the Schmidt hammer indicates that most of the investigated active rockglaciers started to evolve during the early phases of the Holocene or, at the latest, after the early-to-mid Holocene Climatic Optimum (ending around 6.3 ka cal BP). For the dated relict rockglaciers, most of them started to evolve in the second half of the Lateglacial, and probably became inactive at the beginning of the Holocene Climatic Optimum. For the investigated talus slopes, the relative dating carried out allowed to show that their surface date from the period included between the Boreal and the end of the Atlantic, pointing out that the rockwall retreat after the end of the Holocene Climatic Optimum was weak, and that the interval between maximal and minimal ages is in most cases relatively short (4-6 millennia). Therefore, the rockwall retreat during the development period of the talus slopes must has been considerable. Thanks to the calculation of rockwall erosion rates based on the volume of talus accumulations for four of the investigated hillslopes, it was possible to find evidences of the existence of "paraperiglacial rockfall phases" related to the permafrost degradation in rockwalls. These phases coincide with rapid climate warming periods, as at the beginning of the Bølling, during the Preboreal or, maybe, since 1980.

Climate and vegetation history of western Portugal inferred from Albian near-shore deposits (Gale Formation, Lusitanian Basin)

The late Early Cretaceous greenhouse climate has been studied intensively based on proxy data derived essentially from open marine archives. In contrast, information on continental climatic conditions and on the accompanying response of vegetation is relatively scarce, most notably owing to the stratigraphic uncertainties associated with many Lower Cretaceous terrestrial deposits. Here, we present a palynological record from Albian near-shore deposits of the Lusitanian Basin of W Portugal, which have been independently dated using Sr-isotope signals derived from low-Mg oyster shell calcite. Sr-87/Sr-86 values fluctuate between 0.707373 +/- 0.00002 and 0.707456 +/- 0.00003; absolute values and the overall stratigraphic trend match well with the global open marine seawater signature during Albian times. Based on the new Sr-isotope data, existing biostratigraphic assignments of the succession are corroborated and partly revised. Spore-pollen data provide information on the vegetation community structure and are flanked by sedimentological and clay mineralogical data used to infer the overall climatic conditions prevailing on the adjacent continent. Variations in the distribution of climate-sensitive pollen and spores indicate distinct changes in moisture availability across the studied succession with a pronounced increase in hygrophilous spores in late Early Albian times. Comparison with time-equivalent palynofloras from the Algarve Basin of southern Portugal shows pronounced differences in the xerophyte/hygrophyte ratio, interpreted to reflect the effect of a broad arid climate belt covering southern and southeastern Iberia during Early Albian times.

The use of uniaxial accelerometry for the assessment of physical-activity-related energy expenditure: a validation study against whole-body indirect calorimetry.

Assessing the total energy expenditure (TEE) and the levels of physical activity in free-living conditions with non-invasive techniques remains a challenge. The purpose of the present study was to investigate the accuracy of a new uniaxial accelerometer for assessing TEE and physical-activity-related energy expenditure (PAEE) over a 24 h period in a respiratory chamber, and to establish activity levels based on the accelerometry ranges corresponding to the operationally defined metabolic equivalent (MET) categories. In study 1, measurement of the 24 h energy expenditure of seventy-nine Japanese subjects (40 (SD 12) years old) was performed in a large respiratory chamber. During the measurements, the subjects wore a uniaxial accelerometer (Lifecorder; Suzuken Co. Ltd, Nagoya, Japan) on their belt. Two moderate walking exercises of 30 min each were performed on a horizontal treadmill. In study 2, ten male subjects walked at six different speeds and ran at three different speeds on a treadmill for 4 min, with the same accelerometer. O2 consumption was measured during the last minute of each stage and was expressed in MET. The measured TEE was 8447 (SD 1337) kJ/d. The accelerometer significantly underestimated TEE and PAEE (91.9 (SD 5.4) and 92.7 (SD 17.8) % chamber value respectively); however, there was a significant correlation between the two values (r 0.928 and 0.564 respectively; P<0.001). There was a strong correlation between the activity levels and the measured MET while walking (r(2) 0.93; P<0.001). Although TEE and PAEE were systematically underestimated during the 24 h period, the accelerometer assessed energy expenditure well during both the exercise period and the non-structured activities. Individual calibration factors may help to improve the accuracy of TEE estimation, but the average calibration factor for the group is probably sufficient for epidemiological research. This method is also important for assessing the diurnal profile of physical activity.

Gabbro, plagiogranite and associated dykes in the supra-subduction zone Evros Ophiolites, NE Greece

The incomplete Evros ophiolites in NE Greece form a NE-SW-oriented discontinuous belt in the Alpine orogen of the north Aegean. Field data, petrology and geochemistry are presented here for the intrusive section and associated mafic dykes of these ophiolites. Bodies of high-level isotropic gabbro and plagiogranite in the ophiolite suite are cross-cut by NE-SW-trending boninitic and tholeiitic-boninitic affinity dykes, respectively. The dykes fill tensile fractures or faults, which implies dyke emplacement in an extensional tectonic regime. The tholeiitic-transitional boninitic gabbro is REE- and HFS-depleted relative to N-MORB, indicating derivation from melting of a refractory mantle peridotite source. Associated boninitic dykes are slightly LREE-enriched, showing mineral and whole-rock geochemistry similar to the gabbro. The plagiogranite is a strongly REE-enriched high-silica trondhjemite, with textures and composition typical for an oceanic crust differentiate. Plagiogranite-hosted tholeiitic and transitional boninitic dykes are variably REE-enriched. Geochemical modelling indicates origin of the plagiogranite by up to 75% fractional crystallization of basaltic magma similar to that producing the associated tholeiitic dykes. All mafic rocks have high LILE/HFSE ratios and negative Ta-Nb-Ti and Ce anomalies, typical for subduction zone-related settings. The mafic rocks show a similar trace-element character to the mafic lavas of an extrusive section in Bulgaria, suggesting they both form genetically related intrusive and extrusive suites of the Evros ophiolites. The field occurrence, the structural context, the petrology and geochemical signature of the studied magmatic assemblage provide evidence for its origin in a proto-arc (fore-arc) tectonic setting, thus tracing the early stages of the tectono-magmatic evolution of Jurassic arc-marginal basin system that has generated the supra-subduction type Evros ophiolites.