GIS and geodatabases application to global scale plate tectonics modelling

Les reconstructions palinspastiques fournissent le cadre idéal à de nombreuses études géologiques, géographiques, océanographique ou climatiques. En tant qu?historiens de la terre, les "reconstructeurs" essayent d?en déchiffrer le passé. Depuis qu?ils savent que les continents bougent, les géologues essayent de retracer leur évolution à travers les âges. Si l?idée originale de Wegener était révolutionnaire au début du siècle passé, nous savons depuis le début des années « soixante » que les continents ne "dérivent" pas sans but au milieu des océans mais sont inclus dans un sur-ensemble associant croûte « continentale » et « océanique »: les plaques tectoniques. Malheureusement, pour des raisons historiques aussi bien que techniques, cette idée ne reçoit toujours pas l'écho suffisant parmi la communauté des reconstructeurs. Néanmoins, nous sommes intimement convaincus qu?en appliquant certaines méthodes et certains principes il est possible d?échapper à l?approche "Wégenerienne" traditionnelle pour enfin tendre vers la tectonique des plaques. Le but principal du présent travail est d?exposer, avec tous les détails nécessaires, nos outils et méthodes. Partant des données paléomagnétiques et paléogéographiques classiquement utilisées pour les reconstructions, nous avons développé une nouvelle méthodologie replaçant les plaques tectoniques et leur cinématique au coeur du problème. En utilisant des assemblages continentaux (aussi appelés "assemblées clés") comme des points d?ancrage répartis sur toute la durée de notre étude (allant de l?Eocène jusqu?au Cambrien), nous développons des scénarios géodynamiques permettant de passer de l?une à l?autre en allant du passé vers le présent. Entre deux étapes, les plaques lithosphériques sont peu à peu reconstruites en additionnant/ supprimant les matériels océaniques (symbolisés par des isochrones synthétiques) aux continents. Excepté lors des collisions, les plaques sont bougées comme des entités propres et rigides. A travers les âges, les seuls éléments évoluant sont les limites de plaques. Elles sont préservées aux cours du temps et suivent une évolution géodynamique consistante tout en formant toujours un réseau interconnecté à travers l?espace. Cette approche appelée "limites de plaques dynamiques" intègre de multiples facteurs parmi lesquels la flottabilité des plaques, les taux d'accrétions aux rides, les courbes de subsidence, les données stratigraphiques et paléobiogéographiques aussi bien que les évènements tectoniques et magmatiques majeurs. Cette méthode offre ainsi un bon contrôle sur la cinématique des plaques et fournit de sévères contraintes au modèle. Cette approche "multi-source" nécessite une organisation et une gestion des données efficaces. Avant le début de cette étude, les masses de données nécessaires était devenues un obstacle difficilement surmontable. Les SIG (Systèmes d?Information Géographiques) et les géo-databases sont des outils informatiques spécialement dédiés à la gestion, au stockage et à l?analyse des données spatialement référencées et de leurs attributs. Grâce au développement dans ArcGIS de la base de données PaleoDyn nous avons pu convertir cette masse de données discontinues en informations géodynamiques précieuses et facilement accessibles pour la création des reconstructions. Dans le même temps, grâce à des outils spécialement développés, nous avons, tout à la fois, facilité le travail de reconstruction (tâches automatisées) et amélioré le modèle en développant fortement le contrôle cinématique par la création de modèles de vitesses des plaques. Sur la base des 340 terranes nouvellement définis, nous avons ainsi développé un set de 35 reconstructions auxquelles est toujours associé un modèle de vitesse. Grâce à cet ensemble de données unique, nous pouvons maintenant aborder des problématiques majeurs de la géologie moderne telles que l?étude des variations du niveau marin et des changements climatiques. Nous avons commencé par aborder un autre problème majeur (et non définitivement élucidé!) de la tectonique moderne: les mécanismes contrôlant les mouvements des plaques. Nous avons pu observer que, tout au long de l?histoire de la terre, les pôles de rotation des plaques (décrivant les mouvements des plaques à la surface de la terre) tendent à se répartir le long d'une bande allant du Pacifique Nord au Nord de l'Amérique du Sud, l'Atlantique Central, l'Afrique du Nord, l'Asie Centrale jusqu'au Japon. Fondamentalement, cette répartition signifie que les plaques ont tendance à fuir ce plan médian. En l'absence d'un biais méthodologique que nous n'aurions pas identifié, nous avons interprété ce phénomène comme reflétant l'influence séculaire de la Lune sur le mouvement des plaques. La Lune sur le mouvement des plaques. Le domaine océanique est la clé de voute de notre modèle. Nous avons attaché un intérêt tout particulier à le reconstruire avec beaucoup de détails. Dans ce modèle, la croûte océanique est préservée d?une reconstruction à l?autre. Le matériel crustal y est symbolisé sous la forme d?isochrones synthétiques dont nous connaissons les âges. Nous avons également reconstruit les marges (actives ou passives), les rides médio-océaniques et les subductions intra-océaniques. En utilisant ce set de données très détaillé, nous avons pu développer des modèles bathymétriques 3-D unique offrant une précision bien supérieure aux précédents.<br/><br/>Palinspastic reconstructions offer an ideal framework for geological, geographical, oceanographic and climatology studies. As historians of the Earth, "reconstructers" try to decipher the past. Since they know that continents are moving, geologists a trying to retrieve the continents distributions through ages. If Wegener?s view of continent motions was revolutionary at the beginning of the 20th century, we know, since the Early 1960?s that continents are not drifting without goal in the oceanic realm but are included in a larger set including, all at once, the oceanic and the continental crust: the tectonic plates. Unfortunately, mainly due to technical and historical issues, this idea seems not to receive a sufficient echo among our particularly concerned community. However, we are intimately convinced that, by applying specific methods and principles we can escape the traditional "Wegenerian" point of view to, at last, reach real plate tectonics. This is the main aim of this study to defend this point of view by exposing, with all necessary details, our methods and tools. Starting with the paleomagnetic and paleogeographic data classically used in reconstruction studies, we developed a modern methodology placing the plates and their kinematics at the centre of the issue. Using assemblies of continents (referred as "key assemblies") as anchors distributed all along the scope of our study (ranging from Eocene time to Cambrian time) we develop geodynamic scenarios leading from one to the next, from the past to the present. In between, lithospheric plates are progressively reconstructed by adding/removing oceanic material (symbolized by synthetic isochrones) to major continents. Except during collisions, plates are moved as single rigid entities. The only evolving elements are the plate boundaries which are preserved and follow a consistent geodynamical evolution through time and form an interconnected network through space. This "dynamic plate boundaries" approach integrates plate buoyancy factors, oceans spreading rates, subsidence patterns, stratigraphic and paleobiogeographic data, as well as major tectonic and magmatic events. It offers a good control on plate kinematics and provides severe constraints for the model. This multi-sources approach requires an efficient data management. Prior to this study, the critical mass of necessary data became a sorely surmountable obstacle. GIS and geodatabases are modern informatics tools of specifically devoted to store, analyze and manage data and associated attributes spatially referenced on the Earth. By developing the PaleoDyn database in ArcGIS software we converted the mass of scattered data offered by the geological records into valuable geodynamical information easily accessible for reconstructions creation. In the same time, by programming specific tools we, all at once, facilitated the reconstruction work (tasks automation) and enhanced the model (by highly increasing the kinematic control of plate motions thanks to plate velocity models). Based on the 340 terranes properly defined, we developed a revised set of 35 reconstructions associated to their own velocity models. Using this unique dataset we are now able to tackle major issues of the geology (such as the global sea-level variations and climate changes). We started by studying one of the major unsolved issues of the modern plate tectonics: the driving mechanism of plate motions. We observed that, all along the Earth?s history, plates rotation poles (describing plate motions across the Earth?s surface) tend to follow a slight linear distribution along a band going from the Northern Pacific through Northern South-America, Central Atlantic, Northern Africa, Central Asia up to Japan. Basically, it sighifies that plates tend to escape this median plan. In the absence of a non-identified methodological bias, we interpreted it as the potential secular influence ot the Moon on plate motions. The oceanic realms are the cornerstone of our model and we attached a particular interest to reconstruct them with many details. In this model, the oceanic crust is preserved from one reconstruction to the next. The crustal material is symbolised by the synthetic isochrons from which we know the ages. We also reconstruct the margins (active or passive), ridges and intra-oceanic subductions. Using this detailed oceanic dataset, we developed unique 3-D bathymetric models offering a better precision than all the previously existing ones.

Patterns and factors associated with low adherence to psychotropic medications during pregnancy-a cross-sectional, multinational web-based study.

BACKGROUND: No previous studies have explored how closely women follow their psychotropic drug regimens during pregnancy. This study aimed to explore patterns of and factors associated with low adherence to psychotropic medication during pregnancy. METHODS: Multinational web-based study was performed in 18 countries in Europe, North America, and Australia. Uniform data collection was ensured via an electronic questionnaire. Pregnant women were eligible to participate. Adherence was measured via the 8-item Morisky Medication Adherence Scale (MMAS-8). The Beliefs about Prescribed Medicines Questionnaire (BMQ-specific), the Edinburgh Postnatal Depression Scale (EPDS), and a numeric rating scale were utilized to measure women's beliefs, depressive symptoms, and antidepressant risk perception, respectively. Participants reporting use of psychotropic medication during pregnancy (n = 160) were included in the analysis. RESULTS: On the basis of the MMAS-8, 78 of 160 women (48.8%, 95% CI: 41.1-56.4%) demonstrated low adherence during pregnancy. The rates of low adherence were 51.3% for medication for anxiety, 47.2% for depression, and 42.9% for other psychiatric disorders. Smoking during pregnancy, elevated antidepressant risk perception (risk≥6), and depressive symptoms were associated with a significant 3.9-, 2.3-, and 2.5-fold increased likelihood of low medication adherence, respectively. Women on psychotropic polytherapy were less likely to demonstrate low adherence. The belief that the benefit of pharmacotherapy outweighed the risks positively correlated (r = .282) with higher medication adherence. CONCLUSIONS: Approximately one of two pregnant women using psychotropic medication demonstrated low adherence in pregnancy. Life-style factors, risk perception, depressive symptoms, and individual beliefs are important factors related to adherence to psychotropic medication in pregnancy.

The Influence of Age and Sex on Genetic Associations with Adult Body Size and Shape: A Large-Scale Genome-Wide Interaction Study.

Genome-wide association studies (GWAS) have identified more than 100 genetic variants contributing to BMI, a measure of body size, or waist-to-hip ratio (adjusted for BMI, WHRadjBMI), a measure of body shape. Body size and shape change as people grow older and these changes differ substantially between men and women. To systematically screen for age- and/or sex-specific effects of genetic variants on BMI and WHRadjBMI, we performed meta-analyses of 114 studies (up to 320,485 individuals of European descent) with genome-wide chip and/or Metabochip data by the Genetic Investigation of Anthropometric Traits (GIANT) Consortium. Each study tested the association of up to ~2.8M SNPs with BMI and WHRadjBMI in four strata (men ≤50y, men >50y, women ≤50y, women >50y) and summary statistics were combined in stratum-specific meta-analyses. We then screened for variants that showed age-specific effects (G x AGE), sex-specific effects (G x SEX) or age-specific effects that differed between men and women (G x AGE x SEX). For BMI, we identified 15 loci (11 previously established for main effects, four novel) that showed significant (FDR<5%) age-specific effects, of which 11 had larger effects in younger (<50y) than in older adults (≥50y). No sex-dependent effects were identified for BMI. For WHRadjBMI, we identified 44 loci (27 previously established for main effects, 17 novel) with sex-specific effects, of which 28 showed larger effects in women than in men, five showed larger effects in men than in women, and 11 showed opposite effects between sexes. No age-dependent effects were identified for WHRadjBMI. This is the first genome-wide interaction meta-analysis to report convincing evidence of age-dependent genetic effects on BMI. In addition, we confirm the sex-specificity of genetic effects on WHRadjBMI. These results may provide further insights into the biology that underlies weight change with age or the sexually dimorphism of body shape.

Risk factors, aetiology and outcome of ischaemic stroke in young adults: the Swiss Young Stroke Study (SYSS).

Ischaemic stroke (IS) in young adults has been increasingly recognized as a serious health condition. Stroke aetiology is different in young adults than in the older population. This study aimed to investigate aetiology and risk factors, and to search for predictors of outcome and recurrence in young IS patients. We conducted a prospective multicentre study of consecutive IS patients aged 16-55 years. Baseline demographic data, risk factors, stroke aetiology including systematic genetic screening for Fabry disease and severity were assessed and related to functional neurological outcome (modified Rankin Scale, mRS), case fatality, employment status, place of residence, and recurrent cerebrovascular events at 3 months. In 624 IS patients (60 % men), median age was 46 (IQR 39-51) years and median NIHSS on admission 3 (IQR 1-8). Modifiable vascular risk factors were found in 73 %. Stroke aetiology was mostly cardioembolism (32 %) and of other defined origin (24 %), including cervicocerebral artery dissection (17 %). Fabry disease was diagnosed in 2 patients (0.3 %). Aetiology remained unknown in 20 %. Outcome at 3 months was favourable (mRS 0-1) in 61 % and fatal in 2.9 %. Stroke severity (p < 0.001) and diabetes mellitus (p = 0.023) predicted unfavourable outcome. Stroke recurrence rate at 3 months was 2.7 %. Previous stroke or TIA predicted recurrent cerebrovascular events (p = 0.012). In conclusion, most young adults with IS had modifiable vascular risk factors, emphasizing the importance of prevention strategies. Outcome was unfavourable in more than a third of patients and was associated with initial stroke severity and diabetes mellitus. Previous cerebrovascular events predicted recurrent ones.

Very high-resolution digital elevation models: are multi-scale-derived variables ecologically relevant?

1. Digital elevation models (DEMs) are often used in landscape ecology to retrieve elevation or first derivative terrain attributes such as slope or aspect in the context of species distribution modelling. However, DEM-derived variables are scale-dependent and, given the increasing availability of very high-resolution (VHR) DEMs, their ecological relevancemust be assessed for different spatial resolutions. 2. In a study area located in the Swiss Western Alps, we computed VHR DEMs-derived variables related to morphometry, hydrology and solar radiation. Based on an original spatial resolution of 0.5 m, we generated DEM-derived variables at 1, 2 and 4 mspatial resolutions, applying a Gaussian Pyramid. Their associations with local climatic factors, measured by sensors (direct and ambient air temperature, air humidity and soil moisture) as well as ecological indicators derived fromspecies composition, were assessed with multivariate generalized linearmodels (GLM) andmixed models (GLMM). 3. Specific VHR DEM-derived variables showed significant associations with climatic factors. In addition to slope, aspect and curvature, the underused wetness and ruggedness indices modelledmeasured ambient humidity and soilmoisture, respectively. Remarkably, spatial resolution of VHR DEM-derived variables had a significant influence on models' strength, with coefficients of determination decreasing with coarser resolutions or showing a local optimumwith a 2 mresolution, depending on the variable considered. 4. These results support the relevance of using multi-scale DEM variables to provide surrogates for important climatic variables such as humidity, moisture and temperature, offering suitable alternatives to direct measurements for evolutionary ecology studies at a local scale.

Factors Affecting Filterability

In this thesis the factors affecting lime mud filterability were studied. In the literature part there is information about recausticizing process, lime mud properties and filterability, and general filtration theory. In the experimental part the properties of lime mud particles and the properties of lime mud filter cake were investigated and the behavior of lime mud precoat was studied. The experiments were also carried out with R-PCC (rhombohedral precipitated calcium carbonate). The filtration and precoat studies were performed with a laboratory scale pressure filter. The pressure differences used were between 0.25-1.50 bars. Six different lime mud samples with varying amount of impurities and two R-PCC samples were used in the experiments. The average specific cake resistance of different lime mud samples varied quite extensively. The most influential factor affecting the lime mud filterability and dry solids content was found to be silica content. As the lime mud contained silica, the average specific cake resistance was high and the lime mud dryness was low. If the lime mud samples containing silica were not taken into account, the smaller the mean particle size, the higher the average specific cake resistance of the lime mud. The R-PCC had also a high average specific cake resistance, which was because of small particle size. In addition, the pressure difference affected the average specific cake resistance of some lime mud samples. In those cases lime mud was compressible material. During the precoat experiments the lime mud samples having the largest mean particle sizes, compressed. However, the average specific cake resistances of the filtration and precoat part were approximately the same magnitude. A brief displacement by air did not affect the behavior of the precoat. Instead, vibration and a brief but relatively great change in pressure difference had a slight influence.

Large-scale genomic analyses link reproductive aging to hypothalamic signaling, breast cancer susceptibility and BRCA1-mediated DNA repair.

Menopause timing has a substantial impact on infertility and risk of disease, including breast cancer, but the underlying mechanisms are poorly understood. We report a dual strategy in ∼70,000 women to identify common and low-frequency protein-coding variation associated with age at natural menopause (ANM). We identified 44 regions with common variants, including two regions harboring additional rare missense alleles of large effect. We found enrichment of signals in or near genes involved in delayed puberty, highlighting the first molecular links between the onset and end of reproductive lifespan. Pathway analyses identified major association with DNA damage response (DDR) genes, including the first common coding variant in BRCA1 associated with any complex trait. Mendelian randomization analyses supported a causal effect of later ANM on breast cancer risk (∼6% increase in risk per year; P = 3 × 10(-14)), likely mediated by prolonged sex hormone exposure rather than DDR mechanisms.

Divergence with gene flow and fine-scale phylogeographical structure in the wedge-billed woodcreeper, Glyphorynchus spirurus, a Neotropical rainforest bird.

Determining the relative roles of vicariance and selection in restricting gene flow between populations is of central importance to the evolutionary process of population divergence and speciation. Here we use molecular and morphological data to contrast the effect of isolation (by mountains and geographical distance) with that of ecological factors (altitudinal gradients) in promoting differentiation in the wedge-billed woodcreeper, Glyphorynchus spirurus, a tropical forest bird, in Ecuador. Tarsus length and beak size increased relative to body size with altitude on both sides of the Andes, and were correlated with the amount of moss on tree trunks, suggesting the role of selection in driving adaptive divergence. In contrast, molecular data revealed a considerable degree of admixture along these altitudinal gradients, suggesting that adaptive divergence in morphological traits has occurred in the presence of gene flow. As suggested by mitochondrial DNA sequence data, the Andes act as a barrier to gene flow between ancient subspecific lineages. Genome-wide amplified fragment length polymorphism markers reflected more recent patterns of gene flow and revealed fine-scale patterns of population differentiation that were not detectable with mitochondrial DNA, including the differentiation of isolated coastal populations west of the Andes. Our results support the predominant role of geographical isolation in driving genetic differentiation in G. spirurus, yet suggest the role of selection in driving parallel morphological divergence along ecological gradients.

The composition of airborne and grain-dust fungal communities is shaped at regional scale by plant genotypes and farming practices

Chronic exposure to airborne fungi has been associated with different respiratory symptoms and pathologies in occupational populations, such as grain workers. However, the homogeneity in the fungal species composition of these bioaerosols on a large geographical scale and the different drivers that shape these fungal communities remain unclear. In this study, the diversity of fungi in grain dust and in the aerosols released during harvesting was determined across 96 sites at a geographical scale of 560 km(2) along an elevation gradient of 500 m by tag-encoded 454-pyrosequencing of the internal transcribed spacer (ITS) sequences. Associations between the structure of fungal communities in the grain dust and different abiotic (farming system, soil characteristics, geographic and climatic parameters) and biotic (wheat cultivar, previous crop culture) factors were explored. These analyses revealed a strong relationship between the airborne and grain dust fungal communities and showed the presence of allergenic and mycotoxigenic species in most samples, which highlights the potential contribution of these fungal species to work-related respiratory symptoms of grain workers. The farming system was the major driver of the alpha and beta phylogenetic diversity of fungal communities. In addition, elevation and soil CaCO3 concentrations shaped the alpha diversity whereas wheat cultivar, cropping history and the number of freezing days per year shaped the taxonomic beta diversity of these communities.

GENETIC ARCHITECTURE, EVOLUTION AND MAINTENANCE OF A COLOR CLINE AT A CONTINENTAL SCALE

On a geological time scale the conditions on earth are very variable and biological patterns (for example the distributions of species) are very dynamic. Understanding large scale patterns of variation observed today thus requires a deep understanding of the historical factors that drove their evolution. In this thesis, we reevaluated the evolution and maintenance of a continental color cline observed in the European barn owl (Tyto alba) using population genetic tools. The colour cline spans from south-est Europe where most individual have pure white underparts to north and east Europe where most individuals have rufous-brown underparts. Our results globally showed that the old scenario, stipulating that the color cline evolved by secondary contact of two color morphs (white and rufous) that evolved in allopatry during the last ice age has to be revised. We collected samples of about 700 barn owls from the Western Palearctic to establish the first population genetic data set for this species. Individuals were genotyped at 22 microsatellites markers, at one mitochondrial gene, and at a candidate color gene. The color of each individuals was assessed and their sex determined by molecular methods. We first showed that the genetic variation in Western Europe is very limited compared to the heritable color variation. We found no evidences of different glacial lineages, and showed that selection must be involved in the maintenance of the color cline (chapter 1). Using computer simulations, we demonstrated that the post-glacial colonization of Europe occurred from the Iberian Peninsula and that the color cline could not have evolved by neutral demographic processes during this colonization (chapter 2). Finally we reevaluated the whole history of the establishment of the Western Palearctic variation of the barn owl (chapter 3): This study showed that all Western European barn owls descend from white barn owls phenotypes from the Middle East that colonized the Iberian Peninsula via North-Africa. Following the end of the last ice age (20'000 years ago), these white barn owls colonized Western Europe and under selection a novel rufous phenotype evolved (during or after the colonization). An important part of the color variation could be explained by a single mutation in the melanocortin-1-receptor (MC1R) gene that appeared during or after the colonization. The colonization of Europe reached until Greece, where the rufous birds encountered white ones (which reached Greece from the Middle East over the Bosporus) in a secondary contact zone. Our analyses show that white and rufous barn owls in Greece interbreed only to a limited extent. This suggests that barn owls are at the verge of becoming two species in Greece and demonstrates that European barn owls represent an incipient ring species around the Mediterranean. The revisited history of the establishment of the European barn owl color cline makes this model system remarkable for several aspects. It is a very clear example of strong local adaptation that can be achieved despite high gene flow (strong color and MC1R differentiation despite almost no neutral genetic differentiation). It also offers a wonderful model system to study the interactions between colonization processes and selection processes which have, for now, been remarkably understudied despite their potentially ubiquitous importance. Finally it represents a very interesting case in the speciation continuum and appeals for further studying the amount of gene flow that occurs between the color morphs in Greece. -- Sur l'échelle des temps géologiques, les conditions sur terre sont très variables et les patrons biologiques (telle que la distribution des espèces) sont très dynamiques. Si l'on veut comprendre des patrons que l'on peut observer à large échelle aujourd'hui, il est nécessaire de d'abord comprendre les facteurs historiques qui ont gouverné leur établissement. Dans cette thèse, nous allons réévaluer, grâce à des outils modernes de génétique des populations, l'évolution et la maintenance d'un cline de couleur continental observé chez l'effraie des clochers européenne (Tyto alba). Globalement, nos résultats montrent que le scenario accepté jusqu'à maintenant, qui stipule que le cline de couleur a évolué à partir du contact secondaire de deux morphes de couleur (blanches et rousses) ayant évolué en allopatrie durant les dernières glaciations, est à revoir. Afin de constituer le premier jeu de données de génétique des populations pour cette espèce, nous avons récolté des échantillons d'environ 700 effraies de l'ouest Paléarctique. Nous avons génotypé tous les individus à 22 loci microsatellites, sur un gène mitochondrial et sur un autre gène participant au déterminisme de la couleur. Nous avons aussi mesuré la couleur de tous les individus et déterminé leur sexe génétiquement. Nous avons tout d'abord pu montrer que la variation génétique neutre est négligeable en comparaison avec la variation héritable de couleur, qu'il n'existe qu'une seule lignée européenne et que de la sélection doit être impliquée dans le maintien du cline de couleur (chapitre 1). Grâce à des simulations informatiques, nous avons démontré que l'ensemble de l'Europe de l'ouest a été recolonisé depuis la Péninsule Ibérique après les dernières glaciations et que le cline de couleur ne peut pas avoir évolué par des processus neutre durant cette colonisation (chapitre 2). Finalement, nous avons réévalué l'ensemble de l'histoire postglaciaire de l'espèce dans l'ouest Paléarctique (chapitre 3): l'ensemble des effraies du Paléarctique descendent d'effraie claire du Moyen-Orient qui ont colonisé la péninsule ibérique en passant par l'Afrique du nord. Après la fin de la dernière glaciation (il y a 20'000 ans), ces effraies claires ont colonisé l'Europe de l'ouest et ont évolués par sélection le phénotype roux (durant ou après la colonisation). Une part importante de la variation de couleur peut être expliquée par une mutation sur le gène MC1R qui est apparue durant ou juste après la colonisation. Cette vague de colonisation s'est poursuivie jusqu'en Grèce où ces effraies rousses ont rencontré dans une zone de contact secondaire des effraies claires (qui sont remontées en Grèce depuis le Moyen-Orient via le Bosphore). Nos analyses montrent que le flux de gènes entre effraies blanches et rousses est limité en Grèce, ce qui suggère qu'elles sont en passe de former deux espèces et ce qui montre que les effraies constituent un exemple naissant de spéciation en anneaux autour de la Méditerranée. L'histoire revisitée des effraies des clochers de l'ouest Paléarctique en fait un système modèle remarquable pour plusieurs aspects. C'est un exemple très claire de forte adaptation locale maintenue malgré un fort flux de gènes (différenciation forte de couleur et sur le gène MC1R malgré presque aucune structure neutre). Il offre également un très bon système pour étudier l'interaction entre colonisation et sélection, un thème ayant été remarquablement peu étudié malgré son importance. Et il offre finalement un cas très intéressant dans le « continuum de spéciation » et il serait très intéressant d'étudier plus en détail l'importance du flux de gènes entre les morphes de couleur en Grèce.

Evolutionary Ecology of Mountain Birch in Subarctic Stress Gradients: Interplay of Biotic and Abiotic Factors in Plant-Plant Interactions and Evolutionary Processes

In nature, variation for example in herbivory, wind exposure, moisture and pollution impact often creates variation in physiological stress and plant productivity. This variation is seldom clear-cut, but rather results in clines of decreasing growth and productivity towards the high-stress end. These clines of unidirectionally changing stress are generally known as ‘stress gradients’. Through its effect on plant performance, stress has the capacity to fundamentally alter the ecological relationships between individuals, and through variation in survival and reproduction it also causes evolutionary change, i.e. local adaptations to stress and eventually speciation. In certain conditions local adaptations to environmental stress have been documented in a matter of just a few generations. In plant-plant interactions, intensities of both negative interactions (competition) and positive ones (facilitation) are expected to vary along stress gradients. The stress-gradient hypothesis (SGH) suggests that net facilitation will be strongest in conditions of high biotic and abiotic stress, while a more recent ‘humpback’ model predicts strongest net facilitation at intermediate levels of stress. Plant interactions on stress gradients, however, are affected by a multitude of confounding factors, making studies of facilitation-related theories challenging. Among these factors are plant ontogeny, spatial scale, and local adaptation to stress. The last of these has very rarely been included in facilitation studies, despite the potential co-occurrence of local adaptations and changes in net facilitation in stress gradients. Current theory would predict both competitive effects and facilitative responses to be weakest in populations locally adapted to withstand high abiotic stress. This thesis is based on six experiments, conducted both in greenhouses and in the field in Russia, Norway and Finland, with mountain birch (Betula pubescens subsp. czerepanovii) as the model species. The aims were to study potential local adaptations in multiple stress gradients (both natural and anthropogenic), changes in plant-plant interactions under conditions of varying stress (as predicted by SGH), potential mechanisms behind intraspecific facilitation, and factors confounding plant-plant facilitation, such as spatiotemporal, ontogenetic, and genetic differences. I found rapid evolutionary adaptations (occurring within a time-span of 60 to 70 years) towards heavy-metal resistance around two copper-nickel smelters, a phenomenon that has resulted in a trade-off of decreased performance in pristine conditions. Heavy-metal-adapted individuals had lowered nickel uptake, indicating a possible mechanism behind the detected resistance. Seedlings adapted to heavy-metal toxicity were not co-resistant to others forms of abiotic stress, but showed co-resistance to biotic stress by being consumed to a lesser extent by insect herbivores. Conversely, populations from conditions of high natural stress (wind, drought etc.) showed no local adaptations, despite much longer evolutionary time scales. Due to decreasing emissions, I was unable to test SGH in the pollution gradients. In natural stress gradients, however, plant performance was in accordance with SGH, with the strongest host-seedling facilitation found at the high-stress sites in two different stress gradients. Factors confounding this pattern included (1) plant size / ontogenetic status, with seedling-seedling interactions being competition dominated and host-seedling interactions potentially switching towards competition with seedling growth, and (2) spatial distance, with competition dominating at very short planting distances, and facilitation being strongest at a distance of circa ¼ benefactor height. I found no evidence for changes in facilitation with respect to the evolutionary histories of plant populations. Despite the support for SGH, it may be that the ‘humpback’ model is more relevant when the main stressor is resource-related, while what I studied were the effects of ‘non-resource’ stressors (i.e. heavy-metal pollution and wind). The results have potential practical applications: the utilisation of locally adapted seedlings and plant facilitation may increase the success of future restoration efforts in industrial barrens as well as in other wind-exposed sites. The findings also have implications with regard to the effects of global change in subarctic environments: the documented potential by mountain birch for rapid evolutionary change, together with the general lack of evolutionary ‘dead ends’, due to not (over)specialising to current natural conditions, increase the chances of this crucial forest-forming tree persisting even under the anticipated climate change.

Psychological and Family Factors Associated with Suicidal Ideation in Pre-Adolescents

To assess the psychological and family factors associated with suicidal ideation in preadolescent children, we studied a sample of 361 students, average age 9 years old. Twogroups were formed, on the basis of the presence (n = 34) or absence (n = 44) of suicidal ideation. Suicidal ideation was assessed with the Children’s Depression Inventory and the Children’s Depression Rating Scale-Revised. Depression, hopelessness, self-esteem, and perceived family environment were compared in both the suicidal ideation and the control groups. Students with suicidal ideation generally presented greater depressive symptoms and hopelessness, and lower self-esteem and family expressiveness, although there weredifferences both between sexes, and when the variable depression was controlled. Identifying these risk factors in pre-adolescents may have an impact on prevention of suicidal behavior at higher risk ages

Evaluation of prognostic factors of decompressive craniectomy in the treatment of severe traumatic brain injury

OBJECTIVE: to determine predictive factors for prognosis of decompressive craniectomy in patients with severe traumatic brain injury (TBI), describing epidemiological findings and the major complications of this procedure.METHODS: we conducted a retrospective study based on analysis of clinical and neurological outcome, using the extended Glasgow outcome in 56 consecutive patients diagnosed with severe TBI scale treated in the emergency department from February 2004 to July 2012. The variables assessed were age, mechanism of injury, presence of pupillary changes, Glasgow coma scale (GCS) score on admission, CT scan findings (volume, type and association of intracranial lesions, deviation from the midline structures and classification in the scale of Marshall and Rotterdam).RESULTS: we observed that 96.4% of patients underwent unilateral decompressive craniectomy (DC) with expansion duraplasty, and the remainder to bilateral DC, 53.6% of cases being on the right 42.9% on the left, and 3.6% bilaterally, with predominance of the fourth decade of life and males (83.9%). Complications were described as transcalvarial herniation (17.9%), increased volume of brain contusions (16.1%) higroma (16.1%), hydrocephalus (10.7%), swelling of the contralateral lesions (5.3%) and CSF leak (3.6%).CONCLUSION: among the factors studied, only the presence of mydriasis with absence of pupillary reflex, scoring 4 and 5 in the Glasgow Coma Scale, association of intracranial lesions and diversion of midline structures (DML) exceeding 15mm correlated statistically as predictors of poor prognosis.

Dental Health in Preschool and Schoolchildren in Relation to Dental Fear and Some Fear-Related Factors, and the Outcome of a Caries Prevention Program in Offspring of Fearful Mothers

Dental caries and dental fear and anxiety (DFA) are common interrelated problems but so far little is known about these problems in Estonia. The aim was to study dental health in relation to DFA, some fear-related factors, and to study the effect of a caries prevention program in children of fearful mothers. Dental health and DFA were assessed in two Estonian [2-4-year-olds (n=472) and 8-10-year-olds (n=344)], and the effect of some medical conditions on DFA in one Finnish child group [3-year-olds (n=148)]. 120 mother-child-pairs participated in the xylitol-based prevention program. Dental health was examined using the WHO or the ICDAS criteria and expressed as dmft/DMFT-indices. The modified children’s fear survey schedule dental subscale (MCFSS-DS) was used to assess DFA of schoolchildren, one single question to assess parental DFA, and the Corah’s dental anxiety scale (DAS) to assess DFA of mothers in the prevention study. Dentine caries was diagnosed in 42% of the 2-4-year-old and in 93% of the 8-10-year-old Estonian children. DFA of 8-10-year-olds (17%) was associated with experience of dental treatment, and maternal and paternal DFA. Dental apprehension at 9 years of age was associated with frequent exposure to invasive medical care. The xylitol-based prevention was successful irrespective of poor dental hygiene habits and maternal severe DFA. In conclusion, experience of operative dental treatment and DFA of Estonian children were closely associated. Invasive medical care and parental DFA were also linked to children’s DFA. Habitual use of xylitol by mothers was effective in preventing caries even in children of severely fearful mothers.

Periprocedural prognostic factors in coronary interventions – retrospective studies

Background: Approximately 11,000 revascularization procedures, either percutaneous coronary interventions (PCI) or coronary artery bypass grafting surgery (CABG), are performed yearly in Finland for coronary artery disease. Periprocedural risk factors for mortality and morbidity as well as long-term outcome have been extensively studied in general populations undergoing revascularization. Treatment choice between PCI and CABG in many high risk groups and risk-stratification, however, needs clarification and there is still room for improvement in periprocedural outcomes. Materials and methods: Cohorts of patients from Finnish hospitals revascularized between 2001 and 2011 were retrospectively analyzed. Patient records were reviewed for baseline variables and postprocedural outcomes (stroke, myocardial infarction, quality of life measured by the EQ-5D –questionnaire, repeat revascularization, bleeding episodes). Data on date and mode of death was acquired from Statistics Finland. Statistical analysis was performed to identify predictors of adverse events and compare procedures. Results: Postoperative administration of blood products (red blood cells, fresh frozen plasma, platelets) after isolated CABG independently and dose-dependently increases the risk of stroke. Patients 80 years or older who underwent CABG had better survival at 5 years compared to those who underwent PCI. After adjusting for baseline differences survival was similar. Patients on oral anticoagulation (OAC) for atrial fibrillation (AF) treated with CABG had better survival and overall outcome at 3 years compared to PCI patients. There was no difference in incidence of stroke or bleeding episodes. Differences in outcome remained significant after adjusting for propensity score. Lower health-related quality of life (HRQOL) scores as measured by the visual analogue scale (VAS) of the EQ-5D questionnaire at 6 months after CABG predicted later major adverse cardiac and cerebrovascular events (MACCE). Deteriorating function and VAS scores between 0 and 6 months on the EQ-5D also independently predicted later MACCE. Conclusions: Administration of blood products can increase the risk of stroke after CABG and liberal use of transfusions should be avoided. In the frail subpopulations of patients on OAC and octogenarians CABG appears to offer superior long-term outcome as compared to PCI. Deteriorating HRQOL scores predict later adverse events after CABG. Keywords: percutaneous coronary intervention, coronary artery bypass grafting, age over 80, transfusion, anticoagulants, coronary artery disease, health-related quality of life, outcome.