A multi-temporal approach to model endangered species distribution in Europe: the case of the Eurasian otter in Italy

We analysed the relationship between changes in land cover patterns and the Eurasian otter occurrence over the course of about 20 years (1985-2006) using multi-temporal Species Distribution Models (SDMs). The study area includes five river catchments covering most of the otter's Italian range. Land cover and topographic data were used as proxies of the ecological requirements of the otter within a 300-m buffer around river courses. We used species presence, pseudo-absence data, and environmental predictors to build past (1985) and current (2006) SDMs by applying an ensemble procedure through the BIOMOD modelling package. The performance of each model was evaluated by measuring the area under the curve (AUC) of the receiver-operating characteristic (ROC). Multi-temporal analyses of species distribution and land cover maps were performed by comparing the maps produced for 1985 and 2006. The ensemble procedure provided a good overall modelling accuracy, revealing that elevation and slope affected the otter's distribution in the past; in contrast, land cover predictors, such as cultivations and forests, were more important in the present period. During the transition period, 20.5% of the area became suitable, with 76% of the new otter presence data being located in these newly available areas. The multi-temporal analysis suggested that the quality of otter habitat improved in the last 20 years owing to the expansion of forests and to the reduction of cultivated fields in riparian belts. The evidence presented here stresses the great potential of riverine habitat restoration and environmental management for the future expansion of the otter in Italy

A fluorescent hormone biosensor reveals the dynamics of jasmonate signalling in plants.

Activated forms of jasmonic acid (JA) are central signals coordinating plant responses to stresses, yet tools to analyse their spatial and temporal distribution are lacking. Here we describe a JA perception biosensor termed Jas9-VENUS that allows the quantification of dynamic changes in JA distribution in response to stress with high spatiotemporal sensitivity. We show that Jas9-VENUS abundance is dependent on bioactive JA isoforms, the COI1 co-receptor, a functional Jas motif and proteasome activity. We demonstrate the utility of Jas9-VENUS to analyse responses to JA in planta at a cellular scale, both quantitatively and dynamically. This included using Jas9-VENUS to determine the cotyledon-to-root JA signal velocities on wounding, revealing two distinct phases of JA activity in the root. Our results demonstrate the value of developing quantitative sensors such as Jas9-VENUS to provide high-resolution spatiotemporal data about hormone distribution in response to plant abiotic and biotic stresses.

Auxin-mediated plant architectural changes in response to shade and high temperature.

The remarkable plasticity of their architecture allows plants to adjust growth to the environment and to overcome adverse conditions. Two examples of environmental stresses that drastically affect shoot development are imminent shade and high temperature. Plants in crowded environments and plants in elevated ambient temperature display very similar phenotypic adaptations of elongated hypocotyls in seedlings and elevated and elongated leaves at later developmental stages. The comparable growth responses to shade and high temperature are partly regulated through shared signaling pathways, of which the phytohormone auxin and the phytochrome interacting factors (PIFs) are important components. During both shade- and temperature-induced elongation growth auxin biosynthesis and signaling are upregulated in a PIF-dependent manner. In this review we will discuss recent progress in our understanding of how auxin mediates architectural adaptations to shade and high temperature.

Incidence and management of pulmonary embolism following spinal surgery occurring while under chemical thromboprophylaxis.

Patients undergoing spinal surgery are at risk of developing thromboembolic complications even though lower incidences have been reported as compared to joint arthroplasty surgery. Deep vein thrombosis (DVT) has been studied extensively in the context of spinal surgery but symptomatic pulmonary embolism (PE) has engaged less attention. We prospectively followed a consecutive cohort of 270 patients undergoing spinal surgery at a single institution. From these patients, only 26 were simple discectomies, while the largest proportion (226) was fusions. All patients received both low molecular weight heparin (LMWH) initiated after surgery and compressive stockings. PE was diagnosed with spiral chest CT. Six patients developed symptomatic PE, five during their hospital stay. In three of the six patients the embolic event occurred during the first 3 postoperative days. They were managed by the temporary insertion of an inferior vena cava (IVC) filter thus allowing for a delay in full-dose anticoagulation until removal of the filter. None of the PE patients suffered any bleeding complication as a result of the introduction of full anticoagulation. Two patients suffered postoperative haematomas, without development of neurological symptoms or signs, requiring emergency evacuation. The overall incidence of PE was 2.2% rising to 2.5% after exclusion of microdiscectomy cases. The incidence of PE was highest in anterior or combined thoracolumbar/lumbar procedures (4.2%). There is a large variation in the reported incidence of PE in the spinal literature. Results from the only study found in the literature specifically monitoring PE suggest an incidence of PE as high as 2.5%. Our study shows a similar incidence despite the use of LMWH. In the absence of randomized controlled trials (RCT) it is uncertain if this type of prophylaxis lowers the incidence of PE. However, other studies show that the morbidity of LMWH is very low. Since PE can be a life-threatening complication, LMWH may be a worthwhile option to consider for prophylaxis. RCTs are necessary in assessing the efficacy of DVT and PE prophylaxis in spinal patients.

The Role of Transnational Elites in shaping the evolving Field of Internet Governance

La gouvernance de l'Internet est une thématique récente dans la politique mondiale. Néanmoins, elle est devenue au fil des années un enjeu économique et politique important. La question a même pris une importance particulière au cours des derniers mois en devenant un sujet d'actualité récurrent. Forte de ce constat, c ette recherche retrace l'histoire de la gouvernance de l'Internet depuis son émergence comme enjeu politique dans les années 1980 jusqu'à la fin du Sommet Mondial sur la Société de l'Information (SMSI) en 2005. Plutôt que de se focaliser sur l'une ou l'autre des institutions impliquées dans la régulation du réseau informatique mondial, cette recherche analyse l'émergence et l'évolution historique d'un espace de luttes rassemblant un nombre croissant d'acteurs différents. Cette évolution est décrite à travers le prisme de la relation dialectique entre élites et non-élites et de la lutte autour de la définition de la gouvernance de l'Internet. Cette thèse explore donc la question de comment les relations au sein des élites de la gouvernance de l'Internet et entre ces élites et les non-élites expliquent l'emergence, l'évolution et la structuration d'un champ relativement autonome de la politique mondiale centré sur la gouvernance de l'Internet. Contre les perspectives dominantes réaliste et libérales, cette recherche s'ancre dans une approche issue de la combinaison des traditions hétérodoxes en économie politique internationale et des apports de la sociologie politique internationale. Celle-ci s'articule autour des concepts de champ, d'élites et d'hégémonie. Le concept de champ, développé par Bourdieu inspire un nombre croissant d'études de la politique mondiale. Il permet à la fois une étude différenciée de la mondialisation et l'émergence d'espaces de lutte et de domination au niveau transnational. La sociologie des élites, elle, permet une approche pragmatique et centrée sur les acteurs des questions de pouvoir dans la mondialisation. Cette recherche utilise plus particulièrement le concept d'élite du pouvoir de Wright Mills pour étudier l'unification d'élites a priori différentes autour de projets communs. Enfin, cette étude reprend le concept néo-gramscien d'hégémonie afin d'étudier à la fois la stabilité relative du pouvoir d'une élite garantie par la dimension consensuelle de la domination, et les germes de changement contenus dans tout ordre international. A travers l'étude des documents produits au cours de la période étudiée et en s'appuyant sur la création de bases de données sur les réseaux d'acteurs, cette étude s'intéresse aux débats qui ont suivi la commercialisation du réseau au début des années 1990 et aux négociations lors du SMSI. La première période a abouti à la création de l'Internet Corporation for Assigned Names and Numbers (ICANN) en 1998. Cette création est le résultat de la recherche d'un consensus entre les discours dominants des années 1990. C'est également le fruit d'une coalition entre intérêts au sein d'une élite du pouvoir de la gouvernance de l'Internet. Cependant, cette institutionnalisation de l'Internet autour de l'ICANN excluait un certain nombre d'acteurs et de discours qui ont depuis tenté de renverser cet ordre. Le SMSI a été le cadre de la remise en cause du mode de gouvernance de l'Internet par les États exclus du système, des universitaires et certaines ONG et organisations internationales. C'est pourquoi le SMSI constitue la seconde période historique étudiée dans cette thèse. La confrontation lors du SMSI a donné lieu à une reconfiguration de l'élite du pouvoir de la gouvernance de l'Internet ainsi qu'à une redéfinition des frontières du champ. Un nouveau projet hégémonique a vu le jour autour d'éléments discursifs tels que le multipartenariat et autour d'insitutions telles que le Forum sur la Gouvernance de l'Internet. Le succès relatif de ce projet a permis une stabilité insitutionnelle inédite depuis la fin du SMSI et une acceptation du discours des élites par un grand nombre d'acteurs du champ. Ce n'est que récemment que cet ordre a été remis en cause par les pouvoirs émergents dans la gouvernance de l'Internet. Cette thèse cherche à contribuer au débat scientifique sur trois plans. Sur le plan théorique, elle contribue à l'essor d'un dialogue entre approches d'économie politique mondiale et de sociologie politique internationale afin d'étudier à la fois les dynamiques structurelles liées au processus de mondialisation et les pratiques localisées des acteurs dans un domaine précis. Elle insiste notamment sur l'apport de les notions de champ et d'élite du pouvoir et sur leur compatibilité avec les anlayses néo-gramsciennes de l'hégémonie. Sur le plan méthodologique, ce dialogue se traduit par une utilisation de méthodes sociologiques telles que l'anlyse de réseaux d'acteurs et de déclarations pour compléter l'analyse qualitative de documents. Enfin, sur le plan empirique, cette recherche offre une perspective originale sur la gouvernance de l'Internet en insistant sur sa dimension historique, en démontrant la fragilité du concept de gouvernance multipartenaire (multistakeholder) et en se focalisant sur les rapports de pouvoir et les liens entre gouvernance de l'Internet et mondialisation. - Internet governance is a recent issue in global politics. However, it gradually became a major political and economic issue. It recently became even more important and now appears regularly in the news. Against this background, this research outlines the history of Internet governance from its emergence as a political issue in the 1980s to the end of the World Summit on the Information Society (WSIS) in 2005. Rather than focusing on one or the other institution involved in Internet governance, this research analyses the emergence and historical evolution of a space of struggle affecting a growing number of different actors. This evolution is described through the analysis of the dialectical relation between elites and non-elites and through the struggle around the definition of Internet governance. The thesis explores the question of how the relations among the elites of Internet governance and between these elites and non-elites explain the emergence, the evolution, and the structuration of a relatively autonomous field of world politics centred around Internet governance. Against dominant realist and liberal perspectives, this research draws upon a cross-fertilisation of heterodox international political economy and international political sociology. This approach focuses on concepts such as field, elites and hegemony. The concept of field, as developed by Bourdieu, is increasingly used in International Relations to build a differentiated analysis of globalisation and to describe the emergence of transnational spaces of struggle and domination. Elite sociology allows for a pragmatic actor-centred analysis of the issue of power in the globalisation process. This research particularly draws on Wright Mill's concept of power elite in order to explore the unification of different elites around shared projects. Finally, this thesis uses the Neo-Gramscian concept of hegemony in order to study both the consensual dimension of domination and the prospect of change contained in any international order. Through the analysis of the documents produced within the analysed period, and through the creation of databases of networks of actors, this research focuses on the debates that followed the commercialisation of the Internet throughout the 1990s and during the WSIS. The first time period led to the creation of the Internet Corporation for Assigned Names and Numbers (ICANN) in 1998. This creation resulted from the consensus-building between the dominant discourses of the time. It also resulted from the coalition of interests among an emerging power elite. However, this institutionalisation of Internet governance around the ICANN excluded a number of actors and discourses that resisted this mode of governance. The WSIS became the institutional framework within which the governance system was questioned by some excluded states, scholars, NGOs and intergovernmental organisations. The confrontation between the power elite and counter-elites during the WSIS triggered a reconfiguration of the power elite as well as a re-definition of the boundaries of the field. A new hegemonic project emerged around discursive elements such as the idea of multistakeholderism and institutional elements such as the Internet Governance Forum. The relative success of the hegemonic project allowed for a certain stability within the field and an acceptance by most non-elites of the new order. It is only recently that this order began to be questioned by the emerging powers of Internet governance. This research provides three main contributions to the scientific debate. On the theoretical level, it contributes to the emergence of a dialogue between International Political Economy and International Political Sociology perspectives in order to analyse both the structural trends of the globalisation process and the located practices of actors in a given issue-area. It notably stresses the contribution of concepts such as field and power elite and their compatibility with a Neo-Gramscian framework to analyse hegemony. On the methodological level, this perspective relies on the use of mixed methods, combining qualitative content analysis with social network analysis of actors and statements. Finally, on the empirical level, this research provides an original perspective on Internet governance. It stresses the historical dimension of current Internet governance arrangements. It also criticise the notion of multistakeholde ism and focuses instead on the power dynamics and the relation between Internet governance and globalisation.

Transhiatal laparoscopic resection of intrathoracic esophageal duplication in a 6-month-old boy.

We report the case of a 6-month-old boy known antenatally to have a mediastinal cyst. Postnatal workup showed a noncommunicating compressive cyst bound to the lower third of the native esophagus. He underwent its removal by transhiatal laparoscopy. This appears to be the first case of laparoscopic removal of a thoracic esophageal duplication cyst in a child.

Chiasmatic infiltration secondary to late malignant transformation of retinoma.

PURPOSE: To report the lethal course of malignant transformation of retinoma in an adult. METHODS: Case report. A 40-year-old patient presented with retinoma in his right eye and retinoblastoma in his left eye. Enucleation was recommended but refused and the patient received whole eye radiotherapy elsewhere. Five years later he presented again, with temporal hemianopsia of the left eye secondary to chiasmatic invasion. RESULTS: Diagnosis of retinoblastoma infiltration was confirmed by stereotactic biopsy of the chiasmatic lesion. Treatment with intravenous and intrathecal chemotherapy led to partial remission, and was followed by stereotactic irradiation of the chiasmatic mass and right optic nerve. The left eye was enucleated. Death occurred one year later due to cerebrospinal fluid metastases. CONCLUSION: Extraocular extension of retinoblastoma diagnosed in adulthood has never, to our knowledge, been reported. This case stresses the importance of lifelong retinoma monitoring and the necessity for radical treatment in the event of malignant transformation.

Quadrant/octant sequencing and the role of coherent structures in bed load sediment entrainment

To permit the tracking of turbulent flow structures in an Eulerian frame from single-point measurements, we make use of a generalization of conventional two-dimensional quadrant analysis to three-dimensional octants. We characterize flow structures using the sequences of these octants and show how significance may be attached to particular sequences using statistical mull models. We analyze an example experiment and show how a particular dominant flow structure can be identified from the conditional probability of octant sequences. The frequency of this structure corresponds to the dominant peak in the velocity spectra and exerts a high proportion of the total shear stress. We link this structure explicitly to the propensity for sediment entrainment and show that greater insight into sediment entrainment can be obtained by disaggregating those octants that occur within the identified macroturbulence structure from those that do not. Hence, this work goes beyond critiques of Reynolds stress approaches to bed load entrainment that highlight the importance of outward interactions, to identifying and prioritizing the quadrants/octants that define particular flow structures. Key Points <list list-type=''bulleted'' id=''jgrf20196-list-0001''> <list-item id=''jgrf20196-li-0001''>A new method for analysing single point velocity data is presented <list-item id=''jgrf20196-li-0002''>Flow structures are identified by a sequence of flow states (termed octants) <list-item id=''jgrf20196-li-0003''>The identified structure exerts high stresses and causes bed-load entrainment

Microcystic Macular Edema in Optic Nerve Atrophy: A Case Series.

Background:Microcystic macular edema can occur after optic neuropathies of various etiologies, and is easily demonstrated by OCT. We report a cohort of patients with microcystic macular edema. Patients and Methods: All patients with optic neuropathy and microcystic macular edema were enrolled. Demographics, visual function, retinal angiographies and OCT parameters were studied. Results: Nineteen patients (23 eyes) exhibited microcystic macular edema: 10 men/9 women, aged 17-91 years. Etiologies of optic nerve atrophy were compressive (5), inflammatory (4), glaucoma (3), ischemic (3), trauma (2), degenerative (1), and hereditary (1). Median visual acuity was 4/10 (NLP-12/10). Fluorescein angiography showed no leakage. Topography of the microcystic macular edema correlated with near infrared images but with visual field defects in only 26 %. OCT parameters were all abnormal. Conclusions: Microcystic macular edema is a non-specific manifestation from an optic neuropathy of any etiology. The precise mechanism leading to microcystic macular edema remains unknown but trans-synaptic retrograde degeneration with Müller cells dysfunction is likely.

Subcellular Redistribution of Root Aquaporins Induced by Hydrogen Peroxide.

Aquaporins are water channel proteins that mediate the fine-tuning of cell membrane water permeability during development or in response to environmental stresses. The present work focuses on the oxidative stress-induced redistribution of plasma membrane intrinsic protein (PIP) aquaporins from the plasma membrane (PM) to intracellular membranes. This process was investigated in the Arabidopsis root. Sucrose density gradient centrifugation showed that exposure of roots to 0.5 mM H2O2 induces significant depletion in PM fractions of several abundant PIP homologs after 15 min. Analyses by single-particle tracking and fluorescence correlative spectroscopy showed that, in the PM of epidermal cells, H2O2 treatment induces an increase in lateral motion and a reduction in the density of a fluorescently tagged form of the prototypal AtPIP2;1 isoform, respectively. Co-expression analyses of AtPIP2;1 with endomembrane markers revealed that H2O2 triggers AtPIP2;1 accumulation in the late endosomal compartments. Life-time analyses established that the high stability of PIPs was maintained under oxidative stress conditions, suggesting that H2O2 triggers a mechanism for intracellular sequestration of PM aquaporins without further degradation. In addition to information on cellular regulation of aquaporins, this study provides novel and complementary insights into the dynamic remodeling of plant internal membranes during oxidative stress responses.

Mikrozystisches Makulaödem bei Optikusatrophie: eine Fallserie Microcystic Macular Edema in Optic Nerve Atrophy: A Case Series.

Background:Microcystic macular edema can occur after optic neuropathies of various etiologies, and is easily demonstrated by OCT. We report a cohort of patients with microcystic macular edema. Patients and Methods: All patients with optic neuropathy and microcystic macular edema were enrolled. Demographics, visual function, retinal angiographies and OCT parameters were studied. Results: Nineteen patients (23 eyes) exhibited microcystic macular edema: 10 men/9 women, aged 17-91 years. Etiologies of optic nerve atrophy were compressive (5), inflammatory (4), glaucoma (3), ischemic (3), trauma (2), degenerative (1), and hereditary (1). Median visual acuity was 4/10 (NLP-12/10). Fluorescein angiography showed no leakage. Topography of the microcystic macular edema correlated with near infrared images but with visual field defects in only 26 %. OCT parameters were all abnormal. Conclusions: Microcystic macular edema is a non-specific manifestation from an optic neuropathy of any etiology. The precise mechanism leading to microcystic macular edema remains unknown but trans-synaptic retrograde degeneration with Müller cells dysfunction is likely. Zusammenfassung Hintergrund: Das mikrozystische Makulaödem kann im Rahmen einer Optikusatrophie jeglicher Ätiologie auftreten und ist leicht mit dem OCT zu erkennen. Wir berichten über eine Patientenkohorte mit mikrozystischem Makulaödem. Patienten und Methoden: Alle Patienten mit einer Optikusneuropathie und einem mikrozystischen Makulaödem wurden in diese Studie eingeschlossen. Die Demografie, die Sehfunktion, die Netzhautangiografie und die OCT-Parameter wurden untersucht. Ergebnisse: Neunzehn Patienten (23 Augen) hatten ein mikrozystisches Makulaödem: 10 Männer/9 Frauen im Alter von 17 bis 91 Jahren. Die Ursachen der Optikusatrophie waren Kompressionen (5), Entzündungen (4), Glaukom (3), Ischämien (3), Traumata (2), Degenerationen (1) und genetisch (1). Der mittlere Visus war 0,4 (keine Lichtwahrnehmung 1,2). In der Fluoreszenzangiografie fand sich keine Leckage. Das OCT des mikrozystischen Makulaödems korrelierte immer mit den Infrarot-Bildern (Nahaufnahme), jedoch nur in 26 % mit den Gesichtsfelddefekten. Alle OCT-Parameter waren abnormal. Schlussfolgerungen: Das mikrozystische Makulaödem ist eine unspezifische Manifestation einer Optikusneuropathie jeglicher Ätiologie. Der genaue Mechanismus, der zu einem mikrozystischen Makulaödem führt, ist unbekannt, eine trans-synaptische retrograde Degeneration mit Dysfunktion der Müller-Zellen ist jedoch wahrscheinlich.

Dynamic single cell measurements of kinase activity by synthetic kinase activity relocation sensors.

BACKGROUND: Mitogen activated protein kinases (MAPK) play an essential role in integrating extra-cellular signals and intra-cellular cues to allow cells to grow, adapt to stresses, or undergo apoptosis. Budding yeast serves as a powerful system to understand the fundamental regulatory mechanisms that allow these pathways to combine multiple signals and deliver an appropriate response. To fully comprehend the variability and dynamics of these signaling cascades, dynamic and quantitative single cell measurements are required. Microscopy is an ideal technique to obtain these data; however, novel assays have to be developed to measure the activity of these cascades. RESULTS: We have generated fluorescent biosensors that allow the real-time measurement of kinase activity at the single cell level. Here, synthetic MAPK substrates were engineered to undergo nuclear-to-cytoplasmic relocation upon phosphorylation of a nuclear localization sequence. Combination of fluorescence microscopy and automated image analysis allows the quantification of the dynamics of kinase activity in hundreds of single cells. A large heterogeneity in the dynamics of MAPK activity between individual cells was measured. The variability in the mating pathway can be accounted for by differences in cell cycle stage, while, in the cell wall integrity pathway, the response to cell wall stress is independent of cell cycle stage. CONCLUSIONS: These synthetic kinase activity relocation sensors allow the quantification of kinase activity in live single cells. The modularity of the architecture of these reporters will allow their application in many other signaling cascades. These measurements will allow to uncover new dynamic behaviour that previously could not be observed in population level measurements.

Role of an LRR receptor-like kinase in the establishment of a functional root endodermal barrier

The endodermis is a highly conserved cell layer present in the root of all vascular plants, except Lycophytes. This tissue layer establishes a protective diffusion barrier surrounding the vasculature and is expected to prevent passive, uncontrolled flow of nutrients through the root. This barrier property is achieved by the production of Casparian strips (CS), a localized cell wall impregnation of lignin in the anticlinal walls of each endodermal cell, forming a belt-like structure sealing the extracellular space. The CS act as a selective barrier between the external cell layers and the vascular cylinder and are thought to be important in many aspects of root function. For instance, selective nutrient uptake and sequestration from the soil, resistance to different abiotic and biotic stresses are expected to involve functional CS. Although discovered 150 years ago, nothing was known about the genes involved in CS establishment until recently. The use of the model plant Arabidopsis thaliana together with both reverse and forward genetic approaches led to the discovery of an increasing number of genes involved in different steps of CS formation during the last few years. One of these genes encodes SCHENGEN3 (SGN3), a leucine-rich repeat receptor-like kinase (LRR-RLK). SGN3 was discovered first by reverse genetic due to its endodermis-enriched expression, and the corresponding mutant displays strong endodermal permeability of the apoplastic tracer Propidium Iodide (PI) indicative of defective CS. One aim of this thesis is to study the role of SGN3 at the molecular level in order to understand its involvement in establishing an impermeable CS. The endodermal permeability of sgn3 is shown to be the result of incorrect localization of key proteins involved in CS establishment (the "Casparian strip domain proteins", CASPs), leading to non-functional CS interrupted by discontinuities. CASPs localize in the plasma membrane domain subjacent to the CS, named the Casparian Strip membrane Domain (CSD). The CSD discontinuities in sgn3 together with SGN3 localization in close proximity to the CASPs lead to the assumption that SGN3 is involved in the formation of a continuous CSD. In addition, SGN3 might have a second role, acting as a kinase reporting CSD integrity leading to lignin and suberin production in CSD/CS defective plants. Up to now, sgn3 is the strongest and most specific CS mutant available, displaying tracer penetration along the whole length of the seedling root. For this reason, this mutant is well suited in order to characterize the physiological behaviour of CS affected plants. Due to the lack of such mutants in the past, it was not possible to test the presumed functions of CS by using plants lacking this structure. We decided to use sgn3 for this purpose. Surprisingly, sgn3 overall growth is only slightly affected. Nevertheless, processes expected to rely on functional CS, such as water transport through the root, nutrient homeostasis, salt tolerance and resistance to an excess of some nutrients are altered in this mutant. On the other hand, homeostasis for most elements and drought tolerance are not affected in sgn3. It is surprising to observe that homeostatic defects are specific, with a decrease in potassium and an increase in magnesium levels. It indicates a backup system, set up by the plant in order to counteract free diffusion of nutrients into the stele. For instance, potassium shortage in sgn3 upregulates the transcription of potassium influx transport proteins and genes known to be induced by potassium starvation. Moreover, sgn3 mutant is hypersensitive to low potassium conditions. Hopefully, these results about SGN3 will help our understanding of CS establishment at the molecular level. In addition, physiological experiments using sgn3 should give us a framework for future experiments and help us to understand the different roles of CS and their involvement during nutrient radial transport through the root. -- L'endoderme est un tissu présent dans les racines de toutes les plantes vasculaires à l'exception des Lycophytes. Ce tissu établit une barrière protectrice entourant les tissus vasculaires dans le but d'éviter la diffusion passive et incontrôlée des nutriments au travers de la racine. Cette propriété de barrière provient de la production des cadres de Caspary, une imprégnation localisée de lignine des parties anticlinales de la paroi de chaque cellule d'endoderme. Cela donne naissance à un anneau/cadre qui rend étanche l'espace extracellulaire. Les cadres de Caspary agissent comme une barrière sélective entre les couches externes de la racine et le cylindre central et sont supposés être importants dans beaucoup d'aspects du fonctionnement de la racine. Par exemple, l'absorption sélective de nutriments et leur séquestration à partir du sol ainsi que la résistance contre différents stress abiotiques et biotiques sont supposés impliquer des cadres de Caspary fonctionnels. Bien que découverts il y a 150 ans, rien n'était connu concernant les gènes impliqués dans Ja formation des cadres de Caspary jusqu'à récemment. Durant ces dernière années, l'utilisation de la plante modèle Arabidopsis thaliana ainsi que des approches de génétique inverse et classique ont permis la découverte d'un nombre croissant de gènes impliqués à différentes étapes de la formation de cette structure. Un des ces gènes code pour SCHENGEN3 (SGN3), un récepteur kinase "leucine-rich repeat receptor-like kinase" (LRR-RLK). SGN3 a été découvert en premier par génétique inverse grâce à son expression enrichie dans l'endoderme. Les cadres de Caspary ne sont pas fonctionnels dans le mutant correspondant, ce qui est visible à cause de la perméabilité de l'endoderme au traceur apoplastique Propidium Iodide (PI). Un des objectifs de cette thèse est d'étudier la fonction de SGN3 au niveau moléculaire dans le but de comprendre son rôle dans la formation des cadres de Caspary. J'ai pu démontrer que la perméabilité de l'endoderme du mutant sgn3 est le résultat de la localisation incorrecte de protéines impliquées dans la formation des cadres de Caspary, les "Casparian strip domain proteins" (CASPs). Cela induit des cadres de Caspary non fonctionnels, contenant de nombreuses interruptions. Les CASPs sont localisés à la membrane plasmique dans un domaine sous-jacent les cadres de Caspary appelé Casparian Strip membrane Domain (CSD). Les interruptions du CSD dans le mutant sgn3, ainsi que la localisation de SGN3 à proximité des CASPs nous font penser à un rôle de SGN3 dans l'élaboration d'un CSD ininterrompu. De plus, SGN3 pourrait avoir un second rôle, agissant en tant que kinase reportant l'intégrité du CSD et induisant la production de lignine et de subérine dans des plantes contenant des cadres de Caspary non fonctionnels. Jusqu'à ce jour, sgn3 est le mutant en notre possession le plus fort et le plus spécifique, ayant un endoderme perméable tout le long de la racine. Pour cette raison, ce mutant est adéquat dans le but de caractériser la physiologie de plantes ayant des cadres de Caspary affectés. De manière surprenante, la croissance de sgn3 est seulement peu affectée. Néanmoins, des processus censés nécessiter des cadres de Caspary fonctionnels, comme le transport de l'eau au travers de la racine, l'homéostasie des nutriments, la tolérance au sel et la résistance à l'excès de certains nutriments sont altérés dans ce mutant. Malgré tout, l'homéostasie de la plupart des nutriments ainsi que la résistance au stress hydrique ne sont pas affectés dans sgn3. De manière surprenante, les altérations de l'ionome de sgn3 sont spécifiques, avec une diminution de potassium et un excès de magnésium. Cela implique un système de compensation établi par la plante dans le but d'éviter la diffusion passive des nutriments en direction du cylindre central. Par exemple, le manque de potassium dans sgn3 augmente la transcription de transporteurs permettant l'absorption de cet élément. De plus, des gènes connus pour être induits en cas de carence en potassium sont surexprimés dans sgn3 et la croissance de ce mutant est sévèrement affectée dans un substrat pauvre en potassium. Ces résultats concernant SGN3 vont, espérons-le, aider à la compréhension du processus de formation des cadres de Caspary au niveau moléculaire. De plus, les expériences de physiologie utilisant sgn3 présentées dans cette thèse devraient nous donner une base pour des expériences futures et nous permettre de comprendre mieux le rôle des cadres de Caspary, et plus particulièrement leur implication dans le transport radial des nutriments au travers de la racine. -- Les plantes terrestres sont des organismes puisant l'eau et les nutriments dont elles ont besoin pour leur croissance dans le sol grâce à leurs racines. De par leur immobilité, elles doivent s'adapter à des sols contenant des quantités variables de nutriments et il leur est crucial de sélectionner ce dont elles ont besoin afin de ne pas s'intoxiquer. Cette sélection est faite grâce à un filtre formé d'un tissu racinaire interne appelé endoderme. L'endoderme fabrique une barrière imperméable entourant chaque cellule appelée "cadre de Caspary". Ces cadres de Caspary empêchent le libre passage des nutriments, permettant un contrôle précis de leur passage. De plus, ils sont censés permettre de résister contre différents stress environnementaux comme la sécheresse, la salinité du sol ou l'excès de nutriments. Bien que découverts il y a 150 ans, rien n'était connu concernant les gènes impliqués dans la formation des cadres de Caspary jusqu'à récemment. Durant ces dernière années, l'utilisation de la plante modèle Arabidopsis thaliana a permis la découverte d'un nombre croissant de gènes impliqués à différentes étapes de la formation de cette structure. Un de ces gènes code pour SCHENGEN3 (SGN3), un récepteur kinase "leucine-rich repeat receptor-like kinase" (LRR- RLK). Nous montrons dans cette étude que le gène SGN3 est impliqué dans la formation des cadres de Caspary, et que le mutant correspondant sgn3 a des cadres de Caspary interrompus. Ces interruptions rendent l'endoderme perméable, l'empêchant de bloquer le passage des molécules depuis le sol vers le centre de la racine. En utilisant ce mutant, nous avons pu caractériser la physiologie de plantes ayant des cadres de Caspary affectés. Cela a permis de découvrir que le transport de l'eau au travers de la racine était affecté dans le mutant sgn3. De plus, l'accumulation de certains éléments dans les feuilles de ce mutant est altérée. Nous avons également pu montrer une sensibilité de ce mutant à un excès de sel ou de certains nutriments comme le fer et le manganèse.

Are patients with non-invasive papillary thyroid carcinoma, follicular variant (niFV-PTC) and minimally invasive follicular thyroid carcinoma with capsular invasion only (miFTC-CIO) overtreated?An institutional experience

Background. Recently several meetings and position papers advocate a change in terminology regarding thyroid neoplasms with indolent behavior, proposing the term "tumor" instead of "carcinoma". This change concerns non-invasive papillary thyroid carcinoma, follicular variant (niFV-PTC) and minimally invasive follicular thyroid carcinoma with capsular invasion only (miFTC-CIO). The aim of our study was to evaluate the impact of considering niFV-PTC and miFTC-CIO as lesions of low malignant potential, and to see how this change would influence patient management at our institution. Methods. A 32 months retrospective review of all well differentiated thyroid carcinomas (WDTC) (papillary and follicular carcinomas) diagnosed at our institution was performed, excluding tumors of uncertain malignant potential as well as poorly differentiated and anaplastic carcinomas. We retrieved cases of niFV-PTC and miFTC-CIO, reviewed histological slides to confirm diagnosis and recorded patient treatment. Results. A total of 9 (7.3%) niFV-PTC (4 males and 5 females, aged between 30 and 68 years, mean: 50.8 years old) and 2 (1.6%) cases of miFTC-CIO (2 females, 31 and 51 years old) were identified out of 122 WDTC diagnosed in the study period. The initial treatment consisted in 5 lobectomies and 6 total thyroidectomies (3 because of a compressive goiter, 2 because of a fine-needle aspiration diagnosis of suspicious for papillary thyroid carcinoma and 1 because of a fine-needle aspiration diagnosis of papillary carcinoma). The treatment following the histological diagnosis consisted in 4 thyroidectomy completions among patients who underwent simple lobectomy (4/5, 80%) and 9/11 (82%) radioablations with I131. Conclusions. The incidence of niFV-PTC is low at our institution, probably because we apply strict diagnostic criteria for this lesion. Simple lobectomy with negative margins is the treatment of choice in cases diagnosed as niFV-PTC and miFTC-CIO, due to the indolent course of these neoplasms. All cases with thyroidectomy completions and radioablations could have been avoided. As a consequence, the change of such terminology heavily impacts the malignancy risk evaluated cytologically as well as patients' management.

The health of adolescents around a world in transition.

Since several years, the health of adolescents is on the agenda of ministers, decision makers and health professionals. Around the world, while there has been a steady decrease of the death rates among young children, this is not the case for young people. This is mainly linked with the fact that mortality and morbidity during this period of life is largely linked with non communicable diseases and conditions, including deaths from injuries, suicide, homicides and drug abuse. Unplanned pregnancies, illegal abortions, newly acquired HIV infections are also situations that have short and long term consequences. This paper reviews the epidemiological data pertaining to adolescent health and disease. It proposes evidence-informed avenues as how to address these issues in the field of health care (e.g. adolescent friendly services) and of prevention and health promotion. It also stresses the importance of creating safe environments for the development and well-being of young people and thus, of an interdisciplinary and inter sectorial approach to their complex health problems and challenges.