Use of the Cognitive Performance Scale (CPS) to detect cognitive impairment in the acute care setting: concurrent and predictive validity.

The Cognitive Performance Scale (CPS) was initially designed to assess cognition in long term care residents. Subsequently, the CPS has also been used among in-home, post-acute, and acute care populations even though CPS' clinimetric performance has not been studied in these settings. This study aimed to determine CPS agreement with the Mini Mental Status Exam (MMSE) and its predictive validity for institutionalization and death in a cohort (N=401) of elderly medical inpatients aged 75 years and over. Medical, physical and mental status were assessed upon admission. The same day, the patient's nurse completed the CPS by interview. Follow-up data were gathered from the central billing system (nursing home stay) and proxies (death). Cognitive impairment was present in 92 (23%) patients according to CPS (score >or= 2). Agreement with MMSE was moderate (kappa 0.52, P<.001). Analysis of discordant results suggested that cognitive impairment was overestimated by the CPS in dependent patients with comorbidities and depressive symptoms, and underestimated in older ones. During follow-up, subjects with abnormal CPS had increased risks of death (adjusted hazard ratio (adjHR) 1.7, 95% CI 1.0-2.8, P=.035) and institutionalization (adjHR 2.7, 95% CI 1.3-5.3, P=.006), independent of demographic, health and functional status. Interestingly, subjects with abnormal CPS were at increased risk of death only if they also had abnormal MMSE. The CPS predicted death and institutionalization during follow-up, but correlated moderately well with the MMSE. Combining CPS and MMSE provided additional predictive information, suggesting that domains other than cognition are assessed by professionals when using the CPS in elderly medical inpatients.

Fate of the herbicide glyphosate and its metabolite AMPA in soils and their transfer to surface waters: A multi-scale approach in the Lavaux vineyards, western Switzerland

The use of herbicides in agriculture may lead to environmental problems, such as surface water pollution, with a potential risk for aquatic organisms. The herbicide glyphosate is the most used active ingredient in the world and in Switzerland. In the Lavaux vineyards it is nearly the only molecule applied. This work aimed at studying its fate in soils and its transfer to surface waters, using a multi-scale approach: from molecular (10-9 m) and microscopic scales (10-6 m), to macroscopic (m) and landscape ones (103 m). First of all, an analytical method was developed for the trace level quantification of this widely used herbicide and its main by-product, aminomethylphosphonic acid (AMPA). Due to their polar nature, their derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) was done prior to their concentration and purification by solid phase extraction. They were then analyzed by ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The method was tested in different aqueous matrices with spiking tests and validated for the matrix effect correction in relevant environmental samples. Calibration curves established between 10 and 1000ng/l showed r2 values above 0.989, mean recoveries varied between 86 and 133% and limits of detection and quantification of the method were as low as 5 and 10ng/l respectively. At the parcel scale, two parcels of the Lavaux vineyard area, located near the Lutrive River at 6km to the east of Lausanne, were monitored to assess to which extent glyphosate and AMPA were retained in the soil or exported to surface waters. They were equipped at their bottom with porous ceramic cups and runoff collectors, which allowed retrieving water samples for the growing seasons 2010 and 2011. Results revealed that the mobility of glyphosate and AMPA in the unsaturated zone was likely driven by the precipitation regime and the soil characteristics, such as slope, porosity structure and layer permeability discrepancy. Elevated glyphosate and AMPA concentrations were measured at 60 and 80 cm depth at parcel bottoms, suggesting their infiltration in the upper parts of the parcels and the presence of preferential flow in the studied parcels. Indeed, the succession of rainy days induced the gradual saturation of the soil porosity, leading to rapid infiltration through macropores, as well as surface runoff formation. Furthermore, the presence of more impervious weathered marls at 100 cm depth induced throughflows, the importance of which for the lateral transport of the herbicide molecules was determined by the slope steepness. Important rainfall events (>10 mm/day) were clearly exporting molecules from the soil top layer, as indicated by important concentrations in runoff samples. A mass balance showed that total loss (10-20%) mainly occurred through surface runoff (96%) and, to a minor extent, by throughflows in soils (4%), with subsequent exfiltration to surface waters. Observations made in the Lutrive River revealed interesting details of glyphosate and AMPA dynamics in urbanized landscapes, such as the Lavaux vineyards. Indeed, besides their physical and chemical properties, herbicide dynamics at the catchment level strongly depend on application rates, precipitation regime, land use and also on the presence of drains or constructed channels. Elevated concentrations, up to 4970 ng/l, observed just after the application, confirmed the diffuse export of these compounds from the vineyard area by surface runoff during main rain events. From April to September 2011, a total load of 7.1 kg was calculated, with 85% coming from vineyards and minor urban sources and 15% from arable crops. Small vineyard surfaces could generate high concentrations of herbicides and contribute considerably to the total load calculated at the outlet, due to their steep slopes (~10%). The extrapolated total amount transferred yearly from the Lavaux vineyards to the Lake of Geneva was of 190kg. At the molecular scale, the possible involvement of dissolved organic matter (DOM) in glyphosate and copper transport was studied using UV/Vis fluorescence spectroscopy. Combined with parallel factor (PARAFAC) analysis, this technique allowed characterizing DOM of soil and surface water samples from the studied vineyard area. Glyphosate concentrations were linked to the fulvic-like spectroscopic signature of DOM in soil water samples, as well as to copper, suggesting the formation of ternary complexes. In surface water samples, its concentrations were also correlated to copper ones, but not in a significant way to the fulvic-like signature. Quenching experiments with standards confirmed field tendencies in the laboratory, with a stronger decrease in fluorescence intensity for fulvic-like fluorophore than for more aromatic ones. Lastly, based on maximum concentrations measured in the river, an environmental risk for these compounds was assessed, using laboratory tests and ecotoxicity data from the literature. In our case and with the methodology applied, the risk towards aquatic species was found negligible (RF<1).

Beaming into the rat world: enabling real-time intereaction between rat and human each at their own scale

Immersive virtual reality (IVR) typically generates the illusion in participants that they are in the displayed virtual scene where they can experience and interact in events as if they were really happening. Teleoperator (TO) systems place people at a remote physical destination embodied as a robotic device, and where typically participants have the sensation of being at the destination, with the ability to interact with entities there. In this paper, we show how to combine IVR and TO to allow a new class of application. The participant in the IVR is represented in the destination by a physical robot (TO) and simultaneously the remote place and entities within it are represented to the participant in the IVR. Hence, the IVR participant has a normal virtual reality experience, but where his or her actions and behaviour control the remote robot and can therefore have physical consequences. Here, we show how such a system can be deployed to allow a human and a rat to operate together, but the human interacting with the rat on a human scale, and the rat interacting with the human on the rat scale. The human is represented in a rat arena by a small robot that is slaved to the human"s movements, whereas the tracked rat is represented to the human in the virtual reality by a humanoid avatar. We describe the system and also a study that was designed to test whether humans can successfully play a game with the rat. The results show that the system functioned well and that the humans were able to interact with the rat to fulfil the tasks of the game. This system opens up the possibility of new applications in the life sciences involving participant observation of and interaction with animals but at human scale.

Persistence of cognitive impairment and its negative impact on psychosocial functioning in lithium-treated, euthymic bipolar patients: a 6-year follow-up study.

BACKGROUND: Previous cross-sectional studies report that cognitive impairment is associated with poor psychosocial functioning in euthymic bipolar patients. There is a lack of long-term studies to determine the course of cognitive impairment and its impact on functional outcome. Method A total of 54 subjects were assessed at baseline and 6 years later; 28 had DSM-IV TR bipolar I or II disorder (recruited, at baseline, from a Lithium Clinic Program) and 26 were healthy matched controls. They were all assessed with a cognitive battery tapping into the main cognitive domains (executive function, attention, processing speed, verbal memory and visual memory) twice over a 6-year follow-up period. All patients were euthymic (Hamilton Rating Scale for Depression score lower than 8 and Young mania rating scale score lower than 6) for at least 3 months before both evaluations. At the end of follow-up, psychosocial functioning was also evaluated by means of the Functioning Assessment Short Test. RESULTS: Repeated-measures multivariate analysis of covariance showed that there were main effects of group in the executive domain, in the inhibition domain, in the processing speed domain, and in the verbal memory domain (p<0.04). Among the clinical factors, only longer illness duration was significantly related to slow processing (p=0.01), whereas strong relationships were observed between impoverished cognition along time and poorer psychosocial functioning (p<0.05). CONCLUSIONS: Executive functioning, inhibition, processing speed and verbal memory were impaired in euthymic bipolar out-patients. Although cognitive deficits remained stable on average throughout the follow-up, they had enduring negative effects on psychosocial adaptation of patients.

Short-term storage in vitro and large-scale propagation of grapevine genotypes

The objective of this work was to evaluate the large-scale propagation of grapevine genotypes after short-term storage in vitro. Microshoots from ten grapevine genotypes were used. The following storage temperatures were evaluated: 10, 20, and 25°C. After short-term storage, the shoots were propagated in up to five successive subcultures, to assess the large-scale propagation of the germplasm maintained under conditions of minimal growth. The propagated shoots were rooted in different concentrations of indolbutiric acid (IBA) and acclimatized in greenhouse. The best temperature for short-term storage in vitro and survival of the genotypes was 20°C. In the propagation phase, the highest number of shoots per explant was found in the subcultures 4 and 5, with averages of 4.9 and 4.8 shoots per explant, respectively. In the rooting phase, the best results for number of roots were obtained using a culture medium supplemented with 0.4 µmol L-1 of IBA, with an average of three roots per shoot. During the acclimation phase, a survival rate higher than 95% was achieved after 30 days in the greenhouse. Grapevine genotypes maintained for six months in vitro, at 20ºC, can be micropropagated in large scale.

Beaming into the rat world: enabling real-time intereaction between rat and human each at their own scale

Immersive virtual reality (IVR) typically generates the illusion in participants that they are in the displayed virtual scene where they can experience and interact in events as if they were really happening. Teleoperator (TO) systems place people at a remote physical destination embodied as a robotic device, and where typically participants have the sensation of being at the destination, with the ability to interact with entities there. In this paper, we show how to combine IVR and TO to allow a new class of application. The participant in the IVR is represented in the destination by a physical robot (TO) and simultaneously the remote place and entities within it are represented to the participant in the IVR. Hence, the IVR participant has a normal virtual reality experience, but where his or her actions and behaviour control the remote robot and can therefore have physical consequences. Here, we show how such a system can be deployed to allow a human and a rat to operate together, but the human interacting with the rat on a human scale, and the rat interacting with the human on the rat scale. The human is represented in a rat arena by a small robot that is slaved to the human"s movements, whereas the tracked rat is represented to the human in the virtual reality by a humanoid avatar. We describe the system and also a study that was designed to test whether humans can successfully play a game with the rat. The results show that the system functioned well and that the humans were able to interact with the rat to fulfil the tasks of the game. This system opens up the possibility of new applications in the life sciences involving participant observation of and interaction with animals but at human scale.

Beaming into the rat world: enabling real-time intereaction between rat and human each at their own scale

Immersive virtual reality (IVR) typically generates the illusion in participants that they are in the displayed virtual scene where they can experience and interact in events as if they were really happening. Teleoperator (TO) systems place people at a remote physical destination embodied as a robotic device, and where typically participants have the sensation of being at the destination, with the ability to interact with entities there. In this paper, we show how to combine IVR and TO to allow a new class of application. The participant in the IVR is represented in the destination by a physical robot (TO) and simultaneously the remote place and entities within it are represented to the participant in the IVR. Hence, the IVR participant has a normal virtual reality experience, but where his or her actions and behaviour control the remote robot and can therefore have physical consequences. Here, we show how such a system can be deployed to allow a human and a rat to operate together, but the human interacting with the rat on a human scale, and the rat interacting with the human on the rat scale. The human is represented in a rat arena by a small robot that is slaved to the human"s movements, whereas the tracked rat is represented to the human in the virtual reality by a humanoid avatar. We describe the system and also a study that was designed to test whether humans can successfully play a game with the rat. The results show that the system functioned well and that the humans were able to interact with the rat to fulfil the tasks of the game. This system opens up the possibility of new applications in the life sciences involving participant observation of and interaction with animals but at human scale.

Low-fat dairy products and blood pressure: follow-up of 2290 older persons at high cardiovascular risk participating in the PREDIMED study

High blood pressure (BP) has been ranked as the most important risk factor worldwide regarding attributable deaths. Dietary habits are major determinants of BP. Among them, frequent intake of low-fat dairy products may protect against hypertension. Our aim was to assess the relationship between low-fat dairy product intake and BP levels and their changes after 12 month follow-up in a cohort of asymptomatic older persons at high cardiovascular risk recruited into a large-scale trial assessing the effects of Mediterranean diets on cardiovascular outcomes. Data from 2290 participants, including 1845 with hypertension, were available for analyses. Dairy products were not a specific part of the intervention; thus, data were analysed as an observational cohort. Dietary information was collected with validated semi-quantitative FFQ and trained personnel measured BP. To assess BP changes, we undertook cross-sectional analyses at baseline and at the end of follow-up and longitudinal analyses. A statistically significant inverse association between low-fat dairy product intake and systolic BP was observed for the 12-month longitudinal analysis. In the longitudinal analysis, the adjusted systolic and diastolic BP were significantly lower in the highest quintile of low-fat dairy product intake ( 2 4·2 (95% CI 2 6·9, 2 1·4) and 2 1·8 (95% CI 2 3·2, 2 0·4) mmHg respectively), whereas the point estimates for the difference in diastolic BP indicated a modest non-significant inverse association. Intake of low-fat dairy products was inversely associated with BP in an older population at high cardiovascular risk, suggesting a possible protective effect against hypertension.

Low-fat dairy products and blood pressure: follow-up of 2290 older persons at high cardiovascular risk participating in the PREDIMED study

High blood pressure (BP) has been ranked as the most important risk factor worldwide regarding attributable deaths. Dietary habits are major determinants of BP. Among them, frequent intake of low-fat dairy products may protect against hypertension. Our aim was to assess the relationship between low-fat dairy product intake and BP levels and their changes after 12 month follow-up in a cohort of asymptomatic older persons at high cardiovascular risk recruited into a large-scale trial assessing the effects of Mediterranean diets on cardiovascular outcomes. Data from 2290 participants, including 1845 with hypertension, were available for analyses. Dairy products were not a specific part of the intervention; thus, data were analysed as an observational cohort. Dietary information was collected with validated semi-quantitative FFQ and trained personnel measured BP. To assess BP changes, we undertook cross-sectional analyses at baseline and at the end of follow-up and longitudinal analyses. A statistically significant inverse association between low-fat dairy product intake and systolic BP was observed for the 12-month longitudinal analysis. In the longitudinal analysis, the adjusted systolic and diastolic BP were significantly lower in the highest quintile of low-fat dairy product intake ( 2 4·2 (95% CI 2 6·9, 2 1·4) and 2 1·8 (95% CI 2 3·2, 2 0·4) mmHg respectively), whereas the point estimates for the difference in diastolic BP indicated a modest non-significant inverse association. Intake of low-fat dairy products was inversely associated with BP in an older population at high cardiovascular risk, suggesting a possible protective effect against hypertension.

Low-fat dairy products and blood pressure: follow-up of 2290 older persons at high cardiovascular risk participating in the PREDIMED study

High blood pressure (BP) has been ranked as the most important risk factor worldwide regarding attributable deaths. Dietary habits are major determinants of BP. Among them, frequent intake of low-fat dairy products may protect against hypertension. Our aim was to assess the relationship between low-fat dairy product intake and BP levels and their changes after 12 month follow-up in a cohort of asymptomatic older persons at high cardiovascular risk recruited into a large-scale trial assessing the effects of Mediterranean diets on cardiovascular outcomes. Data from 2290 participants, including 1845 with hypertension, were available for analyses. Dairy products were not a specific part of the intervention; thus, data were analysed as an observational cohort. Dietary information was collected with validated semi-quantitative FFQ and trained personnel measured BP. To assess BP changes, we undertook cross-sectional analyses at baseline and at the end of follow-up and longitudinal analyses. A statistically significant inverse association between low-fat dairy product intake and systolic BP was observed for the 12-month longitudinal analysis. In the longitudinal analysis, the adjusted systolic and diastolic BP were significantly lower in the highest quintile of low-fat dairy product intake ( 2 4·2 (95% CI 2 6·9, 2 1·4) and 2 1·8 (95% CI 2 3·2, 2 0·4) mmHg respectively), whereas the point estimates for the difference in diastolic BP indicated a modest non-significant inverse association. Intake of low-fat dairy products was inversely associated with BP in an older population at high cardiovascular risk, suggesting a possible protective effect against hypertension.

Low-fat dairy products and blood pressure: follow-up of 2290 older persons at high cardiovascular risk participating in the PREDIMED study

High blood pressure (BP) has been ranked as the most important risk factor worldwide regarding attributable deaths. Dietary habits are major determinants of BP. Among them, frequent intake of low-fat dairy products may protect against hypertension. Our aim was to assess the relationship between low-fat dairy product intake and BP levels and their changes after 12 month follow-up in a cohort of asymptomatic older persons at high cardiovascular risk recruited into a large-scale trial assessing the effects of Mediterranean diets on cardiovascular outcomes. Data from 2290 participants, including 1845 with hypertension, were available for analyses. Dairy products were not a specific part of the intervention; thus, data were analysed as an observational cohort. Dietary information was collected with validated semi-quantitative FFQ and trained personnel measured BP. To assess BP changes, we undertook cross-sectional analyses at baseline and at the end of follow-up and longitudinal analyses. A statistically significant inverse association between low-fat dairy product intake and systolic BP was observed for the 12-month longitudinal analysis. In the longitudinal analysis, the adjusted systolic and diastolic BP were significantly lower in the highest quintile of low-fat dairy product intake ( 2 4·2 (95% CI 2 6·9, 2 1·4) and 2 1·8 (95% CI 2 3·2, 2 0·4) mmHg respectively), whereas the point estimates for the difference in diastolic BP indicated a modest non-significant inverse association. Intake of low-fat dairy products was inversely associated with BP in an older population at high cardiovascular risk, suggesting a possible protective effect against hypertension.

Low-fat dairy products and blood pressure: follow-up of 2290 older persons at high cardiovascular risk participating in the PREDIMED study

High blood pressure (BP) has been ranked as the most important risk factor worldwide regarding attributable deaths. Dietary habits are major determinants of BP. Among them, frequent intake of low-fat dairy products may protect against hypertension. Our aim was to assess the relationship between low-fat dairy product intake and BP levels and their changes after 12 month follow-up in a cohort of asymptomatic older persons at high cardiovascular risk recruited into a large-scale trial assessing the effects of Mediterranean diets on cardiovascular outcomes. Data from 2290 participants, including 1845 with hypertension, were available for analyses. Dairy products were not a specific part of the intervention; thus, data were analysed as an observational cohort. Dietary information was collected with validated semi-quantitative FFQ and trained personnel measured BP. To assess BP changes, we undertook cross-sectional analyses at baseline and at the end of follow-up and longitudinal analyses. A statistically significant inverse association between low-fat dairy product intake and systolic BP was observed for the 12-month longitudinal analysis. In the longitudinal analysis, the adjusted systolic and diastolic BP were significantly lower in the highest quintile of low-fat dairy product intake ( 2 4·2 (95% CI 2 6·9, 2 1·4) and 2 1·8 (95% CI 2 3·2, 2 0·4) mmHg respectively), whereas the point estimates for the difference in diastolic BP indicated a modest non-significant inverse association. Intake of low-fat dairy products was inversely associated with BP in an older population at high cardiovascular risk, suggesting a possible protective effect against hypertension.

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.

Breaking up the writing process: how wikis can support understanding the composition and revision strategies of young writers

Understanding how best to support immature writers in the development of their understanding of the writing process is an important concern for researchers and teachers. Social technologies have become key features of leisure and work place writing, yet knowledge about how to design educational settings that take full advantage of the affordances of web 2.0 technologies to support early writing is scarce. This paper presents a small scale study that investigated how writing in a wiki environment might facilitate and support students’ use of composition and revision strategies. Our findings show that wiki can enlarge young writers’ experience of the process of composition and revision both through their own efforts and by observing the process in others. In this study students employed a wide range of types of revisions both surface and text based changes. These revisions took place during the process of composition as well as at the end. It is argued here that writing in a wiki not only provides young writers with experience of a mode of composition prevalent in the contemporary work environment, but breaks up the process of writing in a way that may support students’ understanding of the processes of composition and revision.

Effects of inorganic nitrogen (NH4Cl) and biodegradable organic carbon (CH3COONa) additions on a pilot-scale seawater biofilter

Biofilters degrade only a small fraction of the natural organic matter (NOM) contained in seawater which is the leading cause of biofouling in downstream processes. This work studies the effects of chemical additions on NOM biodegradation by biofilters. In this work, biofiltration of seawater with an empty bed contact time (EBCT) of 6 min and a hydraulic loading rate of 10 m h-1 reduces the biological oxygen demand (BOD7) by 8%, the dissolved organic carbon (DOC) by 6% and the UV absorbance at 254 nm (A254) by 7%. Different amounts of ammonium chloride are added to the seawater (up to twice the total dissolved nitrogen in untreated seawater) to study its possible effect on the removal of NOM by a pilot-scale biofilter. Seawater is amended with different amounts of easily biodegradable dissolved organic carbon (BDOC) supplied as sodium acetate (up to twice the DOC) for the same purpose. The results of this work reveal that the ammonium chloride additions do not significantly affect NOM removal and the sodium acetate is completely consumed by the biofiltration process. For both types of chemical additions, the BOD7, DOC and A254 in the outlet stream of the biofilter are similar to the values for the untreated control. These results indicate that this biofilter easily removes the BDOC from the seawater when the EBCT is not above 6 min. Furthermore, nitrogen does not limit the NOM biodegradation in seawater under these experimental conditions.