bluuebunny/crossref_metadata_2025 huggingface dataset:
La légitimité précaire de l'expertise. Un « Centre de ressources » entre science et politique : le Centre Alain Savary (1993-2004)
Authors: Bongrand Philippe
Published: July 2014

À partir des années 1990, la politique française d’éducation prioritaire confie à des « centres de ressources » la mission de faciliter l’élaboration et la diffusion d’outils de travail utiles aux acteurs de terrain. Alors que de telles activités imposent d’opérer des choix politiques, le premier de ces centres, le Centre Alain Savary, est dirigé entre 1993 et 2004 par des chercheurs. L’article retrace les positionnements successifs de ce Centre entre science et politique. Il montre que, dans le champ d’action publique déconcentrée et instrumentée que constitue l’éducation prioritaire, mobiliser la science pour et par la circulation de ressources ne suscite qu’un accord de principe : en pratique, à l’échelle d’une décennie, chercheurs comme politiques ne trouvent pas d’arrangement durable pour définir les modalités souhaitables de leur collaboration. Derrière la continuité institutionnelle apparente du centre, « l’expertise », entendue comme manière d’associer des chercheurs à une action publique, revêt ainsi des formes diverses et précaires, sensibles aux contextes politico-institutionnels.
L'apprentissage des comptines en anglais à l'école élémentaire : modélisation et enjeux épistémiques
Authors: Le Hénaff Carole
Published: July 2014

Cet article a pour objectif de comprendre, grâce à la modélisation de la pratique de la comptine, comment les professeurs des écoles travaillent avec leurs élèves cet objet très répandu dans l’enseignement-apprentissage des langues du premier degré. Nous nous appuyons pour cela sur deux types de données : un questionnaire écrit, administré en ligne à 108 professeurs des écoles, ainsi que l’analyse d’un épisode de classe en CM1-CM2, au cours duquel des élèves apprennent une comptine en anglais. Nous exploitons des outils théoriques développés dans le cadre de la Théorie de l’Action Conjointe en Didactique, en particulier les notions de jeu d’apprentissage et de jeu épistémique source. Nous modélisons la pratique sociale de la comptine, et nous la comparons avec les pratiques didactiques analysées, en cherchant à comprendre ce qui « nourrit » et ce qui fait fonctionner ces pratiques. Nous discutons à la fin de notre article des enjeux épistémiques pour l’enseignement-apprentissage des comptines en anglais que cette comparaison nous a permis de faire ressortir.
Représentation sociale d'un ENT dans l'enseignement secondaire : une étude pour comprendre et analyser les usages
Authors: Schneewele Manuel
Published: July 2014

Dans le cadre d’un travail de recherche qui portait sur l’analyse et la modélisation des usages d’un espace numérique de travail (ENT) dans l’enseignement secondaire, l’étude de sa représentation sociale constitue une étape majeure. Cette variable apporte un ensemble d’indicateurs capables d’expliquer et d’influencer les comportements d’utilisation de l’outil par les membres de la communauté éducative. Les résultats s’appuient sur la déclaration de 1 483 nouveaux utilisateurs et procèdent à une distinction entre enseignants, élèves et parents. La représentation de l’ENT est exposée par la mise en évidence d’une structure hiérarchique parmi les différents éléments qui la composent. Un ensemble d’hypothèses explicitant les motivations et les résistances à l’usage de ces outils est dégagé. Il apparaît ainsi que les élèves et les parents sont particulièrement favorables au déploiement des ENT, néanmoins, les enseignants sont plus réservés. Ces derniers perçoivent ces outils comme particulièrement « lents » et leur utilisation comme susceptible de présenter du « travail » supplémentaire.
L'onirisme et la pensée animiste dans le psychodrame
Authors: Touati Bernard
Published: July 2014

À partir du récit, en 1930, de la mise en acte et en représentation, sous forme de cérémonie et dans un but de guérison, de la vision onirique d’un jeune indien sioux présentant des symptômes psychotiques, sont développées plusieurs réflexions relatives au psychodrame. L’animisme, l’onirisme, la pensée magique ainsi que le jeu des représentations en sont les principales sources. Les notions de « mise en commun », de « réélaborations successives » et d’« interprétation » à travers le travail de psychodrame, permettent de mieux approcher ce qui a été opérant dans le cas étudié : effet anti-traumatique dans un contexte historique de nature génocidaire, redécouverte de la capacité d’être, face à la violence instinctuelle et la confrontation à l’altérité.
De la « dissociation contrainte » à la figuration psychodramatique
Authors: Dupeu Jean-Marc
Published: July 2014

La règle fondamentale, dite d’association libre, est instaurée par Freud comme une prescription visant à la dissociation contrainte du discours au regard des lois du processus secondaire. Or, la clinique montre que la condition pour que le sujet puisse s’y soumettre sans danger suppose l’accès à la figuration par le jeu, précurseur de l’activité fantasmatique. L’offre de la figuration psychodramatique vise à permettre l’accession progressive à ce registre régi par les lois du processus primaire.
Claudine au psychodrame : « C'est moi qui suis confuse »
Authors: Kaswin-Bonnefond Danielle
Published: July 2014

L’excitation est au cœur de la vie somatique et de la vie psychique, essentiellement à travers son traitement par la pulsion via le sexuel infantile. Le travail psychodramatique psychanalytique permet à travers le jeu une figuration dans la présentation des problématiques du patient. La ressaisie qui va pouvoir s’effectuer permet la mobilisation des capacités de symbolisation et de créativité. Une illustration clinique montre l’émergence des capacités d’une jeune patiente enfermée dans un interdit de penser.
Misanthropies
Authors: Angueli Daniella
Published: July 2014

La misanthropie, agencement intérieur ou type d’organisation psychique face à certains aspects de l’environnement, apparaît de visages différents partageant des ressources communes, propres au sujet haïssant : capacité de discerner les dispositions de l’autre envers son semblable et d’en révéler la négativité. De l’Antiquité à nos jours, le misanthrope a mis en lumière les vérités cachées de la communauté humaine et ses aspects non négociables, du fait qu’il se trouve sous l’emprise d’une obligation intérieure de jouer le jeu de son hostilité au point d’aboutir tantôt à des actes de haine, tantôt à un isolement personnel.
Du porno et des hommes
Authors: Maritan Claude
Published: July 2014

Dans ce texte, l’auteur relève que face à l’addiction pornographique, la première réaction est une réaction morale de répréhension. Le psychanalyste lui-même peut avoir une telle attitude qui est une façon d’échapper à tout travail de symbolisation. Il remarque, non sans humour, que la prétention du psychanalyste, dans un tel cas de figure, consisterait en quelque sorte à définir « une nouvelle position du missionnaire ». Il va s’intéresser ensuite aux contenus des films pornos et les spécifier en termes de manque et d’excès ouvrant à la mise en scène d’un fantasme typiquement masculin. À travers l’addiction aux images pornographiques, il s’agirait alors pour un fils de tenter de façon quasi désespérée de restaurer un corps libidinal à une mère qui semblait fonctionner psychiquement selon le savoir tenir à distance de la femme pulsionnelle et libidinale. En terminant, l’auteur esquisse l’hypothèse que pour les filles , l’attraction pour le porno serait d’un registre différent : il serait question de découvrir son propre corps au travers de celui d’une autre femme.
Les livres et les manières de lire à l'école et dans les familles :
Authors: Bonnéry Stéphane
Published: July 2014

L’article est fondé sur plusieurs enquêtes portant sur les usages de la littérature de jeunesse dans les familles et dans l’école. Il montre des choix de livres sensiblement distincts et des manières de lire différentes selon le contexte social des écoles maternelles. Ces variations curriculaires font écho à ce que les élèves sont susceptibles de connaitre le mieux dans leurs contextes socio-familiaux, plutôt que d’enseigner à tous des manières de lire et des contenus communs. Cela permet d’interroger le contexte dans lequel est créée la nouvelle liste de référence d’ouvrages pour la maternelle.
De l'inévitable et heureux inachèvement géographique
Authors: Lefort Isabelle
Published: July 2014

L’inachèvement est l’heureuse caractéristique du processus scientifique lui-même. Parmi les défis les plus contemporains de la géographie, cet article interroge les enjeux renouvelés de son rapport au temps et à l’espace par l’historicisation et la spatialisation de ses savoirs. Ces pratiques de décentrement mettent aujourd’hui en mouvement les catégories de l’analyse et du raisonnement géographiques. Cet inachèvement ouvre dès lors de nouveaux horizons à la saisie géographique du monde.
Le rôle de Monseigneur dans l’accession de Philippe d’Anjou au trône d’Espagne
Authors: Maget Jean-Pierre
Published: July 2014

Le 1er novembre 1700, Charles II d'Espagne mourait sans descendance directe, en précisant par testament : « […] je déclare le Duc d’Anjou pour mon Successeur, & comme tel je l’appelle à la succession de tous mes Royaumes, sans nulle exception […] ». Anjou était le deuxième fils de Monseigneur, successeur légitime du feu roi d’Espagne : en effet, sa mère était la demi-sœur aînée de Charles II, l'infante Marie-Thérèse, épouse de Louis XIV. En excluant le Dauphin et son fils aîné le duc de Bourgogne destinés l'un et l'autre à régner en France, Charles II proclamait son refus que France et Espagne puissent jamais être réunies sous un même roi. Or, bien que le choix du duc d'Anjou l’ait spolié de ses droits incontestables sur l'Espagne, Monseigneur fut d'avis, dès que le testament fut connu, de l'accepter car il espérait ainsi que serait évitée une guerre internationale.
Les valeurs de la création chorégraphique ouest africaine
Authors: Andrieu Sarah
Published: July 2014

La création chorégraphique ouest-africaine met en jeu des appropriations d’esthétiques et d’imaginaires croisées, des rencontres et frictions entre des artistes européens et africains. Elle constitue ainsi un laboratoire particuliè !rement stimulant pour analyser des logiques créatives souvent designées par l’expression floue de « metissage artistique ». Pour saisir ces pratiques de creation dans leur complexité, cet article propose d’appréhender les valeurs qui guident les chorégraphes ouest-afri- cains d’hier et d’aujourd’hui, dans la sélection des matières gestuelles et leur réélaboration créative. Cette perspective permettra de comprendre la diversité des manières d’innover en même temps que leur inscription dans un héritage.
Le rap prédicateur islamique au Sénégal : une musique « missionnaire »
Authors: Niang Abdoulaye
Published: July 2014

La dynamique du rap sénégalais qui clame son aptitude à « parler de tout » semble tout naturellement la préparer à une rencontre inévitable avec l’islam – religion localement majoritaire – doté d’une logique fortement totalisante, et qui « s’occupe de tous les aspects » de la vie de l’individu ainsi que de la communauté. Contre-nature et inopportune ou salvatrice selon différentes conceptions, cette cohabitation a pourtant toujours été présente, mais la nouveauté réside surtout dans la proportion remarquable qu’elle prend. Au-delà du rapport dialogique entre hip hop « Galsen » et « international », de cette hybridité entre sacré et profane, la présence montante du « rap prédicateur islamique » – lui-même traversé par diverses tendances – illustre non seulement l’ancrage du hip hop dans la trame locale des rapports sociaux, mais permet également de procéder à une relecture du rôle du MC et même de la musique plus généralement dans le façonnement des opinions.
Créativité, globalisation et musique
Authors: Stokes Martin
Published: July 2014

Globalization theory has been – however implicitly – highly concerned with the extent to which globalization either enhances or inhibits cultural creativity. Debates about “World Music” exhibit the same concern. These debates – grouped here under the three broad headings of “cultural imperialism”, “hybridity” and “authenticity”, and dealing briefly with case-studies from West and North Africa – imply a persistent anxiety about what might count as “true creativity” as opposed to “imitation”, “translation”, “cultural greyout”, or “bureaucratization”. These categories for describing various kinds of cultural transmission are ideologically-laden, obviously enough, and enshrine western aesthetic values. But they are under pressure from many of the new cultural practices associated with globalization. The task of much “World Music” discourse, I argue, is one of exerting a counter-pressure, of maintaining some of the essential lineaments of western aesthetic ideology. My final case study – a brief discussion of Perrault's Parallèle des Anciens et des Modernes – reminds us that what I am describing here as “World Music discourse” has a long history.
La scène musicale de la champeta face à Internet
Authors: Paulhiac Juan
Published: July 2014

Cet article explore l'impact des médias numériques dans le marché musical de Cartagena (Colombie), en prenant comme étude de cas un phénomène de musique « populaire » locale connue sous le nom de champeta. J’y explique comment un usage local des médias numériques dans ce contexte a permis de créer un modèle économique réactif qui profite du piratage à l’échelle locale. On verra ainsi que l'étude des usages et appropriations des médias numériques dans les marchés culturels informels de pays en développement peut contribuer à diversifier la notion de globalisation culturelle. Ce type d’étude peut aussi aider à mieux comprendre comment la réglementation de l'Internet visant à préserver le modèle économique du droit d’auteur à l’échelle internationale affecte les pratiques culturelles locales dans les économies moins industrialisées.
Altered Expression of Autoimmune Regulator in Infant Down Syndrome Thymus, a Possible Contributor to an Autoimmune Phenotype
Authors: Skogberg Gabriel , Lundberg Vanja , Lindgren Susanne , Gudmundsdottir Judith , Sandström Kerstin , Kämpe Olle , Annerén Göran , Gustafsson Jan , Sunnegårdh Jan , van der Post Sjoerd , Telemo Esbjörn , Berglund Martin , Ekwall Olov
Published: July 2014

Down syndrome (DS), caused by trisomy of chromosome 21, is associated with immunological dysfunctions such as increased frequency of infections and autoimmune diseases. Patients with DS share clinical features, such as autoimmune manifestations and specific autoantibodies, with patients affected by autoimmune polyendocrine syndrome type 1. Autoimmune polyendocrine syndrome type 1 is caused by mutations in the autoimmune regulator (AIRE) gene, located on chromosome 21, which regulates the expression of tissue-restricted Ags (TRAs) in thymic epithelial cells. We investigated the expression of AIRE and TRAs in DS and control thymic tissue using quantitative PCR. AIRE mRNA levels were elevated in thymic tissue from DS patients, and trends toward increased expression of the AIRE-controlled genes INSULIN and CHRNA1 were found. Immunohistochemical stainings showed altered cell composition and architecture of the thymic medulla in DS individuals with increased frequencies of AIRE-positive medullary epithelial cells and CD11c-positive dendritic cells as well as enlarged Hassall’s corpuscles. In addition, we evaluated the proteomic profile of thymic exosomes in DS individuals and controls. DS exosomes carried a broader protein pool and also a larger pool of unique TRAs compared with control exosomes. In conclusion, the increased AIRE gene dose in DS could contribute to an autoimmune phenotype through multiple AIRE-mediated effects on homeostasis and function of thymic epithelial cells that affect thymic selection processes.
Proceedings: International Regulatory Considerations on Development Pathways for Cell Therapies
Authors: Feigal Ellen G. , Tsokas Katherine , Viswanathan Sowmya , Zhang Jiwen , Priest Catherine , Pearce Jonathan , Mount Natalie
Published: July 2014

Regenerative medicine is a rapidly evolving field that faces novel scientific and regulatory challenges. In September 2013, the International Workshop on Regulatory Pathways for Cell Therapies was convened to discuss the nature of these challenges and potential solutions and to highlight opportunities for potential convergence between different regulatory bodies that might assist the field's development. The workshop discussions generated potentially actionable steps in five main areas that could mitigate cell therapy development pathway risk and accelerate moving promising therapies to patients. These included the need for convergence of regulatory guidelines on donor eligibility and suitability of lines for use in clinical trials and subsequent commercialization for cell therapies to move forward on a global basis; the need to challenge and encourage investigators in the regenerative medicine field to share information and provide examples of comparability studies related to master cell banks; the need for convergence of guidelines across regulatory jurisdictions on requirements for tumorigenicity studies, based on particular cell types and on biodistribution studies; the need to increase transparency in sharing clinical trial information more broadly and disseminating results more rapidly; and the need to establish a forum for sharing the experiences of various approaches being developed to expedite regulatory approvals and access for patients to innovative cell and regenerative therapies in the different regulatory jurisdictions and to assess their potential strengths and weaknesses.
The effects of simulated transport on the behaviour of eastern blue tongued lizards (Tiliqua scincoides)
Authors: Mancera K , Murray PJ , Gao YN , Lisle A , Phillips CJC
Published: July 2014

There is widespread transport of reptiles for the pet trade throughout the world and the ‘dead on arrival’ rates are high. The eastern blue tongued (EBT) lizard (Tiliqua scincoides; Order: Squamata; suborder: Lacertilia) is particularly popular due to its unusual blue tongue. Noise, vibration and thermal discomfort are known contributors to transport stress. We analysed the behaviour of EBT lizards (n = 9) when exposed to four of these stimuli in a changeover design. Lizards were exposed to Heat (35°C), Cold (15°C), high or low frequency noise or a Control treatment with no stimulus in a test chamber for a 5-s period. Heating blankets and ice packs were used to create the hot and cold temperature stimuli in the test chamber, and a speaker broadcast noise/vibration from a truck recording. The test chamber was connected to an escape chamber, accessible after exposure to the stimulus, and a small hiding chamber opposite the test chamber. Lizard behaviour was monitored during stimulus exposure and then for a further 15 min, after which each lizard was removed. Lizards exposed to Cold spent less time in the test chamber (330 vs 434 s) and more time inactive in the escape chamber (148 vs 40 s). They also spent longer walking towards the hiding chamber (18.0 vs 10.5 s) and walking in the hiding chamber away from the stimulus (3.6 vs 2.3 s). We conclude that cold temperatures are potentially noxious for lizards in a simulated transport environment as they reduce activity and increase escape attempts.
Shedding ultraviolet light on welfare in laboratory rodents: suggestions for further research and refinement
Authors: SØrensen DB
Published: July 2014

The welfare of laboratory rats and mice is sought to be optimised through adjustment of a variety of environmental factors, including light intensity and photoperiodicity. However, the fact that rodents are able to perceive ultraviolet (UV) light tends to be ignored. The importance of being able — as a rodent — to utilise this part of the visual spectrum has not been studied in great detail, but suggestions, based on the evolutionary success of this trait, indicate that the deprivation of ultraviolet light in mice and rats could perhaps impact negatively on the welfare of these animals. Further research into the importance of having a UV light source available to rats and mice should be encouraged.
Docking the value of pigmeat? Prevalence and financial implications of welfare lesions in Irish slaughter pigs
Authors: Harley S , Boyle LA , O’Connell NE , More SJ , Teixeira DL , Hanlon A
Published: July 2014

Expansion of the meat inspection process to incorporate animal-based welfare measurements could contribute towards significant improvements in pig(Sus scrofa domesticus)welfare and farm profitability. This study aimed to determine the prevalence of different welfare-related lesions on the carcase and their relationship with carcase condemnations (CC) and carcase weight (CW). The financial implications of losses associated with CC and CW reductions related to the welfare lesions were also estimated. Data on tail lesions, loin bruising and bursitis, CW and condemnation/trimming outcome (and associated weights) were collected for 3,537 slaughter pigs (mean [± SEM] carcase weight: 79.2 [± 8.82] kg). Overall, 72.5% of pigs had detectable tail lesions, whilst 16.0 and 44.0% were affected by severe loin bruising and hind limb bursitis, respectively. There were 2.5% of study carcases condemned and a further 3.3% were trimmed. The primary cause of CC was abscessation. While tail lesion severity did not increase the risk of abscessation, it was significantly associated with CC. Male pigs had a higher risk of tail lesions and of CC. The financial loss to producers associated with CC and trimmings was estimated at €1.10 per study pig. CW was reduced by up to 12 kg in cases of severe tail lesions. However, even mild lesions were associated with a significant reduction in CW of 1.2 kg. The value of the loss in potential CW associated with tail lesions was €0.59 per study pig. Combined with losses attributable to CC and trimmings this represented a loss of 43% of the profit margin per pig, at the time of the study, attributable to tail biting. These findings illustrate the magnitude of the impact of tail biting on pig welfare and on profitability of the pig industry. They also emphasise the potential contribution that the inclusion of welfare parameters at meat inspection could make to pig producers in informing herd health and welfare management plans.
Effects of stocking rate on measures of efficacy and welfare during carbon dioxide gas euthanasia of young pigs
Authors: Fiedler KJ , Parsons RL , Sadler LJ , Millman ST
Published: July 2014

The objective of this study was to evaluate the effects of chamber stocking rate on facets of animal welfare and efficacy during gas euthanasia of young pigs(Sus scrofa domesticus). Crossbred pigs (390 neonatal and 270 weaned) designated for euthanasia at production farms were randomly assigned to group sizes of one, two, four, or six pigs. Gas euthanasia of each piglet group was performed in a Euthanex® AgPro chamber. The chamber air was gradually displaced with CO2gas over 5 min to establish an in-chamber concentration of approximately 80% CO2. Pigs remained in that atmosphere for an additional dwell period of at least 5 min. Higher stocking rates were associated with higher CO2concentrations after gradual fill for both age groups. While there was no evidence of an effect of stocking rate on latencies to loss of posture or last movement in neonatal pigs, there was evidence of an effect on all measured efficacy variables in weaned pigs, with grouped pigs faster to succumb than solitary pigs. This finding is consistent with expected consequences of higher CO2concentration at increased stocking densities. Aversive states and behaviours of focal pigs in the chamber were scored from video. Weaned solitary pigs displayed a high incidence of pacing and may have experienced isolation distress. Escape attempts were absent in neonates and not linearly affected by stocking rate in weaned pigs. Although the risk of hazardous interactions was correlated with group size, this study provided no evidence that isolation during gas euthanasia would benefit animal welfare.
Effect of gestation management system on gilt and piglet performance
Authors: Muns R , Manzanilla EG , Manteca X , Gasa J
Published: July 2014

Individual gestation housing of pregnant sows in stalls from four weeks after mating is banned in the EU. Two experiments were conducted to study the effect of two gestation management and housing systems (STALL: gilts housed in stalls and PEN: gilts loose-housed in pens with increased feed ratio) on gilt and piglet performance during lactation. Thirty-seven PEN and 33 STALL gilts were used. Backfat, litter pre-weaning mortality and total feed intake (TFI) during lactation were recorded in gilts. Weight and rectal temperature was recorded in piglets. In Exp 1 the behaviour of a subsample of gilts was videotaped during lactation. In Exp 2 saliva cortisol in gilts, thyroid stimulating hormone (TSH) and T4 hormones in piglet blood were measured. PEN gilts had more backfat when moved to the farrowing stalls. PEN gilts tended to have higher cortisol concentration 24 h after entering the farrowing stall and to spend more time sitting or standing up one day before parturition than STALL gilts. PEN piglets had higher bodyweight (BW) on day 0 (Exp 2) and lower T4 concentration than STALL piglets. However, STALL piglets showed higher rectal temperature 60 min after birth and lower mortality at day 2. In Exp 2, STALL piglets also had higher BW and average daily gain at weaning. During lactation, PEN gilts lost more backfat and weaned less piglets. Gilts loose-housed with increased feed ratio during gestation might be more stressed when housed in farrowing stalls than those kept in stalls during gestation, thus compromising their offsprings’ thermoregulatory capacity and growth however, from our results, it is difficult to differentiate the effect of feed level from the effect of allocation during gestation.
The role of midlatitude mixing barriers in creating the annual variation of total ozone in high northern latitudes
Authors: Gille John , Karol Svetlana , Kinnison Douglas , Lamarque Jean‐Francois , Yudin Valery
Published: July 2014

Data from the HIgh Resolution Dynamics Limb Sounder (HIRDLS), the Microwave Limb Sounder (MLS), and the Whole Atmosphere Community Climate Model (WACCM) are used to investigate the annual variation of total column ozone in high northern latitudes. Downward transport of ozone‐rich air by the residual mean circulation during autumn and winter bends ozone isopleths down and increases the high‐latitude ozone amounts, leading to an ozone maximum at the end of the winter. During the summer months eddy mixing acts to restore pre‐fall distributions of ozone. In this study the large‐scale mixing in the lower stratosphere is analyzed using Nakamura's (1996) equivalent length formulation with observed and simulated ozone. The analysis of ozone mixing is performed in the tracer equivalent latitude‐potential temperature coordinate system. Steep latitudinal gradients of ozone isopleths below about 500 K occur during the winter, where there are minima in the equivalent length, indicating barriers to mixing at 30°N–40°N. This transport barrier allows large ozone maxima to develop poleward of it. The barrier disappears over the summer, permitting latitudinal mixing of the high ozone air. Above 500 K mixing is more effective during the winter, so a large winter maximum does not occur. In both midlatitude and high latitude the lower stratospheric layer from 330 to 500 K doubles its ozone content from autumn to spring, compared with much smaller changes in the layer from 500 to 650 K. Our results confirm that the presence of the winter transport barrier in the lower stratosphere controls the seasonal variation of total ozone.
Particle sorting during sediment redistribution processes and the effect on 230Th‐normalized mass accumulation rates
Authors: Marcantonio Franco , Lyle Mitchell , Ibrahim Rami
Published: July 2014

The 230Th method of determining mass accumulation rates (MARs) assumes that little to no fractionation occurs during sediment redistribution processes at the seafloor. We examine 230Th inventories in radiocarbon‐dated multicore sediments from paired winnowed and focused sites at Cocos and Carnegie Ridges, Panama Basin. Radiocarbon‐derived sand MARs, which likely represent the vertical rain of particles poorly transported by bottom currents, are similar at each of the paired sites but are different using 230Th normalization. 230Th‐normalized MARs are about 60% lower at focused sites and likely underestimate vertical MARs, while the reverse is true for winnowed sites. We hypothesize that size fractionation occurs most frequently at lower current velocities, resulting in the coarse fraction being left behind and primarily the fine 230Th‐rich grains being transported downslope. 230Th‐normalization works well for recording fine‐grained (detrital and opal), but not coarse‐grained (carbonate), fluxes in regions that have undergone sediment redistribution.
Enhanced acidification of global coral reefs driven by regional biogeochemical feedbacks
Authors: Cyronak Tyler , Schulz Kai G. , Santos Isaac R. , Eyre Bradley D.
Published: July 2014

Physical uptake of anthropogenic CO2 is the dominant driver of ocean acidification (OA) in the open ocean. Due to expected decreases in calcification and increased dissolution of CaCO3 framework, coral reefs are thought to be highly susceptible to OA. However, biogeochemical processes can influence the pCO2 and pH of coastal ecosystems on diel and seasonal time scales, potentially modifying the long‐term effects of increasing atmospheric CO2. By compiling data from the literature and removing the effects of short‐term variability, we show that the average pCO2 of coral reefs throughout the globe has increased ~3.5‐fold faster than in the open ocean over the past 20 years. This rapid increase in pCO2 has the potential to enhance the acidification and predicted effects of OA on coral reef ecosystems. A simple model demonstrates that potential drivers of elevated pCO2 include additional anthropogenic disturbances beyond increasing global atmospheric CO2 such as enhanced nutrient and organic matter inputs.
Wind and wave extremes over the world oceans from very large ensembles
Authors: Breivik Øyvind , Aarnes Ole Johan , Abdalla Saleh , Bidlot Jean‐Raymond , Janssen Peter A.E.M.
Published: July 2014

Global return values of marine wind speed and significant wave height are estimated from very large aggregates of archived ensemble forecasts at +240 h lead time. Long lead time ensures that the forecasts represent independent draws from the model climate. Compared with ERA‐Interim, a reanalysis, the ensemble yields higher return estimates for both wind speed and significant wave height. Confidence intervals are much tighter due to the large size of the data set. The period (9 years) is short enough to be considered stationary even with climate change. Furthermore, the ensemble is large enough for nonparametric 100 year return estimates to be made from order statistics. These direct return estimates compare well with extreme value estimates outside areas with tropical cyclones. Like any method employing modeled fields, it is sensitive to tail biases in the numerical model, but we find that the biases are moderate outside areas with tropical cyclones.
Radiative forcing and temperature change at Potsdam between 1893 and 2012
Authors: Stanhill Gerald , Ahiman Ori
Published: July 2014

Radiative forcing in both the short and long‐wave lengths reaching the Earth's surface accounted for more than 80% of the inter‐annual variations in the mean yearly temperatures measured at Potsdam, Germany, during the last 120 years. Three quarters of the increase in the long‐wave flux was due to changes in the water content of the lower atmosphere; the remainder was attributed to increases in CO2 and other anthropogenic, radiatively active gases. Over the period radiative forcing in the short‐wave flux slightly exceeded that in the long wave, but its effect on air temperature was much less as the climate sensitivity to atmospheric radiation, 0.187°C per W m−2, was three times greater than to short‐wave global radiation. This anomalous finding, similar to that previously reported at two coastal sites, awaits explanation as does the complex interaction existing between radiative forcing and advection in determining temperature change.
Development of topographic asymmetry: Insights from dated cinder cones in the western United States
Authors: McGuire Luke A. , Pelletier Jon D. , Roering Joshua J.
Published: July 2014

Topographic asymmetry, that is, differences in the morphology of landscapes as a function of slope aspect, can be used to infer ecohydrogeomorphic feedback relationships. In this study, we document the dependence of topographic gradients and drainage densities on slope aspect and time/age in four Quaternary cinder cone fields in Arizona, Oregon, and California. Cinder cones are particularly useful as natural experiments in geomorphic evolution because they begin their evolution at a known time in the past (many have been radiometrically dated) and because they often have simple, well‐constrained initial morphologies. North‐facing portions of cinder cones have steeper topographic gradients and higher mean vegetation cover (i.e., Normalized Difference Vegetation Index, or NDVI, values) under current climatic conditions compared with corresponding south‐facing portions of cones within each volcanic field. Drainage density is also higher on north‐facing portions of cones in three of the four volcanic fields. These differences in topography were not present initially but developed progressively over time, indicating that the asymmetry is a result of post‐eruption geomorphic processes. To test alternative hypotheses for the slope‐aspect control of topography, we developed a numerical model for cinder cone evolution and a methodology for estimating local paleovegetation cover as a function of elevation, slope aspect, and time within the Quaternary. The numerical model results demonstrate that rates of colluvial transport were higher on south‐facing hillslopes in at least three of the four cinder cones fields. Our paleovegetation analysis suggests that in the two Arizona volcanic fields we studied, higher rates of colluvial transport on south‐facing hillslopes were the result of greater time‐averaged vegetation cover and hence higher rates of sediment transport by floral bioturbation. Our results illustrate the profound impact that relatively small variations in solar insolation can have on landscapes via feedbacks among hydrology, vegetation cover, and sediment transport.
Diagnostic accuracy of CSF Ab42 and florbetapir PET for Alzheimer's disease
Authors: Mattsson Niklas , Insel Philip S. , Landau Susan , Jagust William , Donohue Michael , Shaw Leslie M. , Trojanowski John Q. , Zetterberg Henrik , Blennow Kaj , Weiner Michael ,   the Alzheimer's Disease Neuroimaging Initiative
Published: July 2014

Background

Reduced cerebrospinal fluid (CSF) β‐amyloid42 (Aβ42) and increased florbetapir positron emission tomography (PET) uptake reflects brain Aβ accumulation. These biomarkers are correlated with each other and altered in Alzheimer's disease (AD), but no study has directly compared their diagnostic performance.

Methods

We examined healthy controls (CN, N = 169) versus AD dementia patients (N = 118), and stable (sMCI; no dementia, followed up for at least 2 years, N = 165) versus progressive MCI (pMCI; conversion to AD dementia, N = 59). All subjects had florbetapir PET (global and regional; temporal, frontal, parietal, and cingulate) and CSF Aβ42 measurements at baseline. We compared area under the curve (AUC), sensitivity, and specificity (testing a priori and optimized cutoffs). Clinical diagnosis was the reference standard.

Results

CSF Aβ42 and (global or regional) PET florbetapir did not differ in AUC (CN vs. AD, CSF 84.4%; global PET 86.9%; difference [95% confidence interval] −6.7 to 1.5). CSF Aβ42 and global PET florbetapir did not differ in sensitivity, but PET had greater specificity than CSF in most comparisons. Sixteen CN progressed to MCI and AD (six Aβ negative, seven Aβ positive, and three PET positive but CSF negative).

Interpretation

The overall diagnostic accuracies of CSF Aβ42 and PET florbetapir were similar, but PET had greater specificity. This was because some CN and sMCI subjects appear pathological using CSF but not using PET, suggesting that low CSF Aβ42 not always translates to cognitive decline or brain Aβ accumulation. Other factors, including costs and side effects, may also be considered when determining the optimal modality for different applications.
Interpenetrated Gel Polymer Binder for High‐Performance Silicon Anodes in Lithium‐ion Batteries
Authors: Song Jiangxuan , Zhou Mingjiong , Yi Ran , Xu Terrence , Gordin Mikhail L. , Tang Duihai , Yu Zhaoxin , Regula Michael , Wang Donghai
Published: July 2014

Silicon has attracted ever‐increasing attention as a high‐capacity anode material in Li‐ion batteries owing to its extremely high theoretical capacity. However, practical application of silicon anodes is seriously hindered by its fast capacity fading as a result of huge volume changes during the charge/discharge process. Here, an interpenetrated gel polymer binder for high‐performance silicon anodes is created through in‐situ crosslinking of water‐soluble poly(acrylic acid) (PAA) and polyvinyl alcohol (PVA) precursors. This gel polymer binder with deformable polymer network and strong adhesion on silicon particles can effectively accommodate the large volume change of silicon anodes upon lithiation/delithiation, leading to an excellent cycling stability and high Coulombic efficiency even at high current densities. Moreover, high areal capacity of ∼4.3 mAh/cm2 is achieved based on the silicon anode using the gel PAA–PVA polymer binder with a high mass loading. In view of simplicity in using the water soluble gel polymer binder, it is believed that this novel binder has a great potential to be used for high capacity silicon anodes in next generation Li‐ion batteries, as well as for other electrode materials with large volume change during cycling.
Hybrid Organic‐Inorganic Biosensor for Ammonia Operating under Harsh Physiological Conditions
Authors: Kumar Tatikonda Anand , Capua Eyal , Tkachev Maria , Adler Samuel N. , Naaman Ron
Published: July 2014

A biosensor for ammonia is developed aimed at detecting the presence of H. pylori bacteria in gastric fluids. The sensor is based on a GaAs device coated with a unique functional polymer that enables high device sensitivity to low concentrations of ammonia and long‐term protection in harsh environments. The detection of ammonia in gastric fluids taken from patients is possible by covering the device with a dialysis membrane, thus enabling the diffusion of only small molecules to the sensing area, while preventing agglomeration of macromolecules on the surface of the device. The mechanism by which ammonia is detected is investigated and an analytical expression is provided relating the response of the detector to the ammonia concentration and the pH of the solution.
The adjustable synergistic effects between acid–base coupling bifunctional ionic liquid extractants for rare earth separation
Authors: Sun Xiaoqi , Waters Kristian E.
Published: July 2014

Two of the most widely used industrial extractants for rare earth elements (REEs), that is, di(2‐ethylhexyl)phosphoric acid (HDEHP) and 2‐ethyl(hexyl) phosphonic acid mono‐2‐ethylhexyl ester (HEH[EHP]) were developed into [DEHP]− type acid–base coupling bifunctionalized ionic liquids (ABC‐BILs) and [EHEHP]− type ABC‐BILs, respectively. The combinations of ABC‐BIL extractants revealed synergistic effects for REEs. Seven different combinations of ABC‐BILs and five kinds of REEs confirmed the novel synergistic extraction. Some synergy coefficients of the combined ABC‐BILs were bigger than those of mixed HDEHP and HEH[EHP] by two orders of magnitude. The first synergistic extraction produced by ionic liquid extractants in the field of solvent extraction was reported in this article. The novel synergistic extraction from combined ABC‐BILs extractants revealed highly efficient and environmentally friendly potential in both of academic research and industrial application for REEs separation. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3859–3868, 2014
A lattice Boltzmann simulation of mass transport through composite membranes
Authors: Zhang Li‐Zhi
Published: July 2014

Composite membranes with a porous support layer and a dense skin layer have been extensively used in gas separation processes. A new approach, a mesoscale Lattice Boltzmann Simulation approach, is proposed and used to model the pore‐scale gas flow and mass transfer in the inhomogeneous membrane matrixes studied. Only physical forces are considered. Chemical forces are equivalently converted to physical forces through the relaxation time. Selective permeation of moisture through a composite membrane is modeled. The overall permeability is evaluated. It is found that mass transfer inhomogeneity exists not only in the porous media but also in the seemingly uniform dense skin layer. Increasing the diffusivity in the skin layer is more effective than decreasing the skin layer thickness in optimizing the overall membrane performance. The new approach gives more detailed insights into the directions for future design of composite membranes for gas separations like air dehumidification. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3925–3938, 2014
Adult c‐Kit(+) progenitor cells are necessary for maintenance and regeneration of olfactory neurons
Authors: Goldstein Bradley J. , Goss Garrett M. , Hatzistergos Konstantinos E. , Rangel Erika B. , Seidler Barbara , Saur Dieter , Hare Joshua M.
Published: July 2014

The olfactory epithelium houses chemosensory neurons, which transmit odor information from the nose to the brain. In adult mammals, the olfactory epithelium is a uniquely robust neuroproliferative zone, with the ability to replenish its neuronal and non‐neuronal populations due to the presence of germinal basal cells. The stem and progenitor cells of these germinal layers, and their regulatory mechanisms, remain incompletely defined. Here we show that progenitor cells expressing c‐Kit, a receptor tyrosine kinase marking stem cells in a variety of embryonic tissues, are required for maintenance of the adult neuroepithelium. Mouse genetic fate‐mapping analyses show that embryonically, a c‐Kit(+) population contributes to olfactory neurogenesis. In adults under conditions of normal turnover, there is relatively sparse c‐Kit(+) progenitor cell (ckPC) activity. However, after experimentally induced neuroepithelial injury, ckPCs are activated such that they reconstitute the neuronal population. There are also occasional non‐neuronal cells found to arise from ckPCs. Moreover, the selective depletion of the ckPC population, utilizing temporally controlled targeted diphtheria toxin A expression, results in failure of neurogenesis after experimental injury. Analysis of this model indicates that most ckPCs reside among the globose basal cell populations and act downstream of horizontal basal cells, which can serve as stem cells. Identification of the requirement for olfactory c‐Kit–expressing progenitors in olfactory maintenance provides new insight into the mechanisms involved in adult olfactory neurogenesis. Additionally, we define an important and previously unrecognized site of adult c‐Kit activity. J. Comp. Neurol. 523:15–31, 2015. © 2014 Wiley Periodicals, Inc.
Target‐ and input‐dependent organization of AMPA and NMDA receptors in synaptic connections of the cochlear nucleus
Authors: Rubio María E , Fukazawa Yugo , Kamasawa Naomi , Clarkson Cheryl , Molnár Elek , Shigemoto Ryuichi
Published: July 2014

We examined the synaptic structure, quantity, and distribution of α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid (AMPA)‐ and N‐methyl‐D‐aspartate (NMDA)‐type glutamate receptors (AMPARs and NMDARs, respectively) in rat cochlear nuclei by a highly sensitive freeze‐fracture replica labeling technique. Four excitatory synapses formed by two distinct inputs, auditory nerve (AN) and parallel fibers (PF), on different cell types were analyzed. These excitatory synapse types included AN synapses on bushy cells (AN‐BC synapses) and fusiform cells (AN‐FC synapses) and PF synapses on FC (PF‐FC synapses) and cartwheel cell spines (PF‐CwC synapses). Immunogold labeling revealed differences in synaptic structure as well as AMPAR and NMDAR number and/or density in both AN and PF synapses, indicating a target‐dependent organization. The immunogold receptor labeling also identified differences in the synaptic organization of FCs based on AN or PF connections, indicating an input‐dependent organization in FCs. Among the four excitatory synapse types, the AN‐BC synapses were the smallest and had the most densely packed intramembrane particles (IMPs), whereas the PF‐CwC synapses were the largest and had sparsely packed IMPs. All four synapse types showed positive correlations between the IMP‐cluster area and the AMPAR number, indicating a common intrasynapse‐type relationship for glutamatergic synapses. Immunogold particles for AMPARs were distributed over the entire area of individual AN synapses; PF synapses often showed synaptic areas devoid of labeling. The gold‐labeling for NMDARs occurred in a mosaic fashion, with less positive correlations between the IMP‐cluster area and the NMDAR number. Our observations reveal target‐ and input‐dependent features in the structure, number, and organization of AMPARs and NMDARs in AN and PF synapses. J. Comp. Neurol. 522:4023–4042, 2014. © 2014 Wiley Periodicals, Inc.
Fitness consequences of maternal and grandmaternal effects
Authors: Prizak Roshan , Ezard Thomas H. G. , Hoyle Rebecca B.
Published: July 2014

Transgenerational effects are broader than only parental relationships. Despite mounting evidence that multigenerational effects alter phenotypic and life‐history traits, our understanding of how they combine to determine fitness is not well developed because of the added complexity necessary to study them. Here, we derive a quantitative genetic model of adaptation to an extraordinary new environment by an additive genetic component, phenotypic plasticity, maternal and grandmaternal effects. We show how, at equilibrium, negative maternal and negative grandmaternal effects maximize expected population mean fitness. We define negative transgenerational effects as those that have a negative effect on trait expression in the subsequent generation, that is, they slow, or potentially reverse, the expected evolutionary dynamic. When maternal effects are positive, negative grandmaternal effects are preferred. As expected under Mendelian inheritance, the grandmaternal effects have a lower impact on fitness than the maternal effects, but this dual inheritance model predicts a more complex relationship between maternal and grandmaternal effects to constrain phenotypic variance and so maximize expected population mean fitness in the offspring.