bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study on the Pedagogical Components of Massive Online Courses
Authors: Raposo-Rivas Manuela , Martínez-Figueira Esther , Sarmiento-Campos José Antonio
Published: October 2014

At the end of the first decade of the 21st century, the rapid growth in the MOOC offering brought about a new educational landscape, posing new challenges to teaching and learning, mainly due to massive participation, ubiquity and free enrollment. These courses embody a confluence of technological and pedagogical mediations yet to be fully explored. This study, applying an instrument of educational and interactive indicators on a MOOC (INdiMOOC-EdI) designed by the authors, seeks to ascertain the pedagogical components of MOOCs delivered in the Spanish language in order to establish which course features are platform dependent. An exploratory sequential mixed methods study was carried out on a total of 117 courses within 10 different platforms via an instrument developed and validated ad hoc. The data obtained is subjected to a content analysis for a qualitative perspective; while a quantitative perspective is obtained through a statistical analysis complemented with classification algorithms typical in data mining. The results suggest that the different platform providers condition the pedagogical design of the MOOC in five key areas: learning, activities and tasks, means and resources, interactivity and assessment. It concludes with a series of descriptive, educational and interactive indicators that can be a pedagogical benchmark for future MOOCs.

A finales de la primera década del siglo XXI, el rápido aumento de cursos MOOC dibuja un nuevo panorama educativo planteando nuevos retos a la enseñanza y al aprendizaje debido, fundamentalmente, a sus características de masividad, ubicuidad y gratuidad. En estos cursos se da una confluencia de mediaciones tecnológicas y pedagógicas aún por explorar en todas sus dimensiones. Este trabajo, utilizando un instrumento de indicadores educativos e interactivos en un MOOC (INdiMOOC-EdI) de elaboración propia, se centra en averiguar qué componentes pedagógicos posee la actual oferta de MOOC en lengua hispana, para poder dirimir aquellos elementos dependientes de las plataformas que los soportan. Para ello se realiza una investigación mixta de tipo exploratoria y secuencial que analiza un total de 117 cursos ubicados en 10 plataformas diferentes, utilizando el instrumento creado y validado a tal efecto. Con la información obtenida se lleva a cabo un análisis de contenido en su vertiente cualitativa, mientras que con la cuantitativa se efectúan análisis estadísticos complementados con algoritmos propios de la minería de datos. Los resultados muestran que las diferentes plataformas condicionan los diseños pedagógicos del MOOC en cinco aspectos fundamentales: el aprendizaje, las actividades y tareas, los medios y recursos, la interactividad y la evaluación. Se concluye con una serie de indicadores de tipo descriptivo, formativo e interactivo que pueden orientar la pedagogía de futuros Cursos Online Masivos Abiertos.
A Digital Repository of Filmic Content as a Teaching Resource
Authors: Tobías-Martínez Miguel Ángel , Duarte-Freitas María do Carmo , Kemczinski Avanilde
Published: October 2014

The use of video as a teaching resource stimulates the construction of new knowledge. Although this resource exists in several genres and media, the experience of professionals that use this resource in class is not appreciated. Furthermore, online spaces guiding and supporting the appropriate use of this practice are unavailable. In the online learning field, a proposal has emerged for a repository of short videos aimed at instructing how to use them as a teaching resource in order to stimulate the exchange of ideas and experience (fostering and creating knowledge) in the teaching-learning process, which serves as a resource for professionals in the construction of MOOCs (Massive Open Online Courses). A three-stage architecture is methodologically proposed: identification/recognition, dissemination and collaboration in the use of videos as a teaching resource supported by an extensive exploratory research, based on existing educational technologies and technological trends for higher education. And this leads to the creation of a repository of Informational Content Recovery in Videos (RECIF), a virtual space for the exchange of experience through videos. We conclude that through methodologies that facilitate the development of innovative processes and products, it is possible to create spaces for virtual or face-to-face motivational classes (MOOCs) thereby completing an interactive and collaborative learning toward stimulation of creativity and dynamism.

El uso de vídeos como recurso didáctico estimula la construcción de nuevo conocimiento. A pesar de la existencia de este recurso en diversos géneros y medios, no se valora la experiencia de los profesionales que lo aprovechan en clase y además no se cuenta con espacios online que orienten y apoyen el uso apropiado de esta práctica. En el ámbito del aprendizaje online, surge la propuesta de un repositorio de vídeos de corta duración, con el objetivo de orientar acerca de su uso como recurso didáctico, a fin de incentivar un intercambio de ideas y experiencias (fomentar y crear conocimiento), en el proceso enseñanza-aprendizaje, sirviendo esto como recurso para profesionales en la construcción de los MOOC (Massive Open Online Courses). Metodológicamente se propone una arquitectura en tres etapas: identificación/reconocimiento, diseminación y colaboración, para el uso de vídeos como recurso didáctico, sustentándose en una extensa investigación exploratoria, basándose en las tecnologías educativas existentes y tendencias tecnológicas para la educación superior. El resultado es la creación de un repositorio de Recuperación de Contenido de Información en Vídeos (RECIF), un espacio virtual de intercambio de experiencias por medio de vídeos. Se concluye que por medio de metodologías que faciliten el desarrollo de procesos y productos innovadores, se pueden crear espacios de clases motivadoras, virtuales o presenciales, que completen un aprendizaje interactivo y colaborativo, estimulando la creatividad y el dinamismo.
Internet Use Habits and Risk Behaviours in Preadolescence
Authors: Fernández-Montalvo Javier , Peñalva-Vélez María Alicia , Irazabal Itziar
Published: October 2014

A striking increase in the use of new information and communication technology has come about in recent years. This study analysed the characteristics and habits of Internet use in a sample of pre-adolescents between 10 and 13 years of age, enrolled in the 6th grade of primary school in Navarra (Spain). Likewise, the existence of differential patterns in Internet use by sex was analysed, and risk behaviours were detected. The sample was composed of 364 students (206 boys and 158 girls) who were evaluated at their schools. Information about socio-demographic characteristics, Internet use habits, and online behaviours was collected using a data-gathering tool specifically designed for the study. The results demonstrated high Internet use by the adolescents studied. Girls used the Internet more for social relationships, whereas boys tended to use it differently, including accessing online games. Moreover, some risky behaviours were found, including interactions with strangers, giving out personal information, and sending photos and videos. Likewise, behaviours associated with «cyber-bullying» were detected. These results indicate the necessity of establishing prevention programs for safe and responsible Internet use.

En los últimos años se ha producido un aumento espectacular del uso de las nuevas tecnologías de la información y de la comunicación. En este estudio se analizaron las características y el patrón del uso de Internet en una muestra de preadolescentes de entre 10 y 13 años, que cursan 6º curso de Educación Primaria en Navarra (España). Asimismo, se analizó la existencia de un perfil diferencial en el uso de Internet en función del sexo y se detectó la existencia de conductas de riesgo. La muestra estaba compuesta por 364 estudiantes (206 chicos y 158 chicas), que fueron evaluados en sus centros educativos. Se recogió información sobre las características sociodemográficas, los hábitos de uso de Internet y los comportamientos desarrollados en la Red a través de un instrumento de recogida de datos diseñado específicamente para la investigación. Los resultados mostraron un uso elevado de Internet por parte de los adolescentes estudiados. Las chicas usaban más Internet para las relaciones sociales, mientras que los chicos tendían a darle otro tipo de usos, como el acceso a juegos online. Además, se encontraron algunas conductas de riesgo, como quedar con desconocidos, dar datos personales o enviar fotos y vídeos. Asimismo, se encontraron comportamientos relacionados con el «ciberbullying». Estos resultados indican la necesidad de establecer programas de prevención para el uso seguro y responsable de Internet.
Forms of Media Convergence and Multimedia Content – A Romanian Perspective
Authors: Drula Georgeta
Published: October 2014

This paper addresses two types of technological media convergence: media convergence based on mobile technology, and also convergence based on the unification between IT and media industry. These forms are influenced by the multimedia aspects of the content. The research interest in this study is related to media landscape in Romania and its state. Even if many academics and practitioners consider media convergence only at the content level from journalistic perspective, this topic has many more detail aspects and trends. Thus, media convergence in terms of content can be now interpreted together with the user’s content and takes into consideration the unification between paid, owned, shared and earned content. This paper proposes a theoretical and practical perspective for the relationship between convergence and multimedia for online media products. This perspective belongs both to media producers and to online consumers of information. The paper is interesting in that it reveals the challenges facing the media industries, and shows approaches of convergence that are related to multimedia for media products. The methodological framework uses the content analysis and the hierarchical cluster analysis to discover different forms of convergence in online media. The main conclusion of this study shows that due to various technologies and their partnerships, convergence can be directed both from the users to the media industry, and conversely.

Este artículo se centra en dos tipos de convergencia tecnológica de medios: la basada en tecnología móvil, y la convergencia basada en la unificación de las tecnologías de la información y la industria mediática. Estas formas están influidas por los aspectos multimedia del contenido. El interés de la investigación de este estudio se centra en el panorama mediático en Rumanía y en su estado actual. Aunque muchos académicos y profesionales evalúan la convergencia de medios por el contenido desde una perspectiva periodística, existen otros muchos aspectos y tendencias a tener en cuenta. Así, la convergencia de medios en términos de contenido puede ser interpretada junto al contenido del usuario y considera la unificación del contenido pagado, poseído, compartido y adquirido. Este artículo propone una perspectiva teórica y práctica para la relación entre convergencia y multimedia en cuanto a los productos mediáticos on-line. Esta perspectiva se refiere a los productores y a los consumidores de la información. El interés del artículo reside en tanto que identifica los retos de la industria mediática y establece enfoques acerca de la convergencia multimedia para los productos mediáticos. La metodología consiste en el análisis de contenido y en el agrupamiento jerárquico con el objetivo de descubrir diferentes formas de convergencia de medios on-line. La conclusión establece que, gracias a varias tecnologías y sus asociaciones, la convergencia puede dirigirse desde el usuario a la industria y viceversa.
Teaching Media Literacy in Colleges of Education and Communication
Authors: López-Romero Laura , Aguaded-Gómez María de la Cinta
Published: October 2014

This work is part of an R&D project involving thirteen Spanish universities in which needs and wants in the field of media education in higher education are studied in the areas of Communication (Communication Studies, Journalism and Advertising) and Education (Teaching, Pedagogy, Psychology and Social Education). The objective of this study focuses on analysing the college textbooks directly related to Media Education most used in Education and Communication,. The report has been developed based on six educational competence dimensions: language, technology, interaction processes, production and distribution processes, ideology and values and aesthetics. Using each of these parameters the scope of the analysis and the scope of the expression were taken into account, based on guidelines set by Ferrés and Piscitelli in their well-known proposal of indicators for defining new media competence and which is structured around two areas of work: the production of own messages and interaction with others. The results were obtained by applying a quantitative methodology through a content analysis of semantic fields. The main conclusions point to a greater presence of the «Ideology and Values» dimension, and almost non-existent representation of the «Aesthetics» indicator.

El presente trabajo forma parte de un proyecto I+D integrado por trece universidades españolas en el que se estudian las necesidades y carencias en materia de educación mediática en el ámbito de la enseñanza superior, tanto en las áreas de Comunicación (Comunicación Audiovisual, Periodismo y Publicidad) como de Educación (Magisterio, Pedagogía, Psicopedagogía y Educación Social). Esta investigación centra su objeto de estudio en el análisis de los manuales universitarios más utilizados en Educación y Comunicación, en asignaturas directamente relacionadas con la educación mediática. Este informe se ha desarrollado en base a seis dimensiones competenciales mediáticas: lenguajes, tecnología, procesos de interacción, procesos de producción y difusión, ideología y valores y estética. De cada uno de estos parámetros se ha tenido en cuenta el ámbito del análisis y de la expresión, partiendo de las pautas señaladas por Ferrés y Piscitelli en su conocida propuesta articulada de indicadores para definir la nueva competencia mediática, que se ha estructurado en torno a dos ámbitos de trabajo: el de la producción de mensajes propios y el de la interacción con otros ajenos. Los resultados han sido obtenidos mediante la aplicación de una metodología cuantitativa, a través de un análisis de contenido por campos semánticos. Las principales conclusiones extraídas apuntan hacia una mayor presencia de la dimensión Ideología y Valores, y una casi inexistente representación de la dimensión Estética.
Wavelet Entropy Algorithm to Allocate the Extreme Power Peaks in WiMax Systems
Authors: Daoud Omar , Hamarsheh Qadri , Saraireh Saleh
Published: October 2014

This work proposes a solution to overcome the effect for one of the main drawbacks of these days’ wireless systems, where Multiple-Input Multiple-Output (MIMO)-Orthogonal Frequency Division Multiplexing (OFDM) combinations has been used. High peak-to-average power ratio (PAPR) arises after the OFDM stage and reduces the performance of the used nonlinear devices. Therefore, a new stage has been imposed between the MIMO and OFDM block. It is based on the entropy meaning of the wavelet transformation to trigger a proposed thresholding criterion and reconstruct the OFDM signal. As a result, the probability of high PAPR appearance will be limited and reduced; a promising result over our recently published work has been conducted; 15-25% extra reduction. This work could be denoted by MIMO-OFDM based on Entropy Wavelet Transform (MO-EWT) systems.

The MO-EWT validity has been checked based on either numerical analysis or conducted simulation based on MATLAB; where 80% improvement of reducing the high PAPR has been achieved over the literature. These results have been reached using the same environment conditions and at additional cost and complexity of the transceivers structure.
Affordances in Mobile Augmented Reality Applications
Authors: Gjøsæter Tor
Published: October 2014

This paper explores the affordances of augmented reality content in a mobile augmented reality application. A user study was conducted by performing a multi-camera video recording of seven think aloud sessions. The think aloud sessions consisted of individual users performing tasks, exploring and experiencing a mobile augmented reality (MAR) application we developed for the iOS platform named ARad. We discuss the instrumental affordances we observed when users interacted with augmented reality content, as well as more complex affordances rising from conventions from media content, AR and the traditional WIMP paradigm. We find that remediation of traditional newspaper content through the MAR medium can provide engaging, pleasing and exciting user experiences. However, the some of the content still suffers from being shoveled onto the MAR platform without adapting it properly. Finally, we discuss what content was most successfully mediated to the user and how the content impacts the user experience.
Social Media and e-Participation
Authors: Vogt Sebastian , Förster Bernadette , Kabst Rüdiger
Published: October 2014

e-Participation has advantages over traditional modes of public participation: independent of time and place, information can be provided and updated at reasonable costs. A broad range of citizens can be involved regardless of demographics, family or work situation, thereby broadening the basis for public participation. Thus, public authorities seek to employ social media for the purposes of project management in terms of e-Participation. Nevertheless, social media presents challenges that need to be resolved to be suitable for e-Participation, such as user-friendliness, technical requirements for information preparation, and data protection requirements. Reviewing the literature, it is concluded that although common social media solutions are successful in generating attention for participation projects, they are not necessarily appropriate for conducting the project itself. Therefore, the case of a reference company offering a specialized platform and social network is introduced. It was identified as good practice in recent reports published by the European Commission.
Cytomegalovirus Enhances Macrophage TLR Expression and MyD88-Mediated Signal Transduction To Potentiate Inducible Inflammatory Responses
Authors: Smith Phillip D. , Shimamura Masako , Musgrove Lois C. , Dennis Evida A. , Bimczok Diane , Novak Lea , Ballestas Mary , Fenton Anne , Dandekar Satya , Britt William J. , Smythies Lesley E.
Published: October 2014

Circulating monocytes carrying human CMV (HCMV) migrate into tissues, where they differentiate into HCMV-infected resident macrophages that upon interaction with bacterial products may potentiate tissue inflammation. In this study, we investigated the mechanism by which HCMV promotes macrophage-orchestrated inflammation using a clinical isolate of HCMV (TR) and macrophages derived from primary human monocytes. HCMV infection of the macrophages, which was associated with viral DNA replication, significantly enhanced TNF-α, IL-6, and IL-8 gene expression and protein production in response to TLR4 ligand (LPS) stimulation compared with mock-infected LPS-stimulated macrophages during a 6-d in vitro infection. HCMV infection also potentiated TLR5 ligand–stimulated cytokine production. To elucidate the mechanism by which HCMV infection potentiated inducible macrophage responses, we show that infection by HCMV promoted the maintenance of surface CD14 and TLR4 and TLR5, which declined over time in mock-infected macrophages, and enhanced both the intracellular expression of adaptor protein MyD88 and the inducible phosphorylation of IκBα and NF-κB. These findings provide additional information toward elucidating the mechanism by which HCMV potentiates bacteria-induced NF-κB–mediated macrophage inflammatory responses, thereby enhancing organ inflammation in HCMV-infected tissues.
Tumor-Derived α-Fetoprotein Impairs the Differentiation and T Cell Stimulatory Activity of Human Dendritic Cells
Authors: Pardee Angela D. , Shi Jian , Butterfield Lisa H.
Published: October 2014

Several tumor-derived factors have been implicated in dendritic cell (DC) dysfunction in cancer patients. α-fetoprotein (AFP) is an oncofetal Ag that is highly expressed in abnormalities of prenatal development and several epithelial cancers, including hepatocellular carcinoma (HCC). In HCC patients exhibiting high levels of serum AFP, we observed a lower ratio of myeloid/plasmacytoid circulating DCs compared with patients with low serum AFP levels and healthy donors. To test the effect of AFP on DC differentiation in vitro, peripheral blood monocytes from healthy donors were cultured in the presence of cord blood–derived normal AFP (nAFP) or HCC tumor-derived AFP (tAFP), and DC phenotype and function were assessed. Although the nAFP and tAFP isoforms only differ at one carbohydrate group, low (physiological) levels of tAFP, but not nAFP, significantly inhibited DC differentiation. tAFP-conditioned DCs expressed diminished levels of DC maturation markers, retained a monocyte-like morphology, exhibited limited production of inflammatory mediators, and failed to induce robust T cell proliferative responses. Mechanistic studies revealed that the suppressive activity of tAFP is dependent on the presence of low molecular mass (LMM) species that copurify with tAFP and function equivalently to the LMM fractions of both tumor and nontumor cell lysates. These data reveal the unique ability of tAFP to serve as a chaperone protein for LMM molecules, both endogenous and ubiquitous in nature, which function cooperatively to impair DC differentiation and function. Therefore, novel therapeutic approaches that antagonize the regulatory properties of tAFP will be critical to enhance immunity and improve clinical outcomes.
Overcoming the Dichotomy of Quantity and Quality in Antibody Responses
Authors: Meyer-Hermann Michael
Published: October 2014

Germinal centers (GCs) are specialized environments in which B cells mutate their BCR to identify new Abs with high affinity to a challenging Ag. B cells are selected in an evolutionary process of multiple rounds of mutation and selection. In the past decade, mechanisms of B cell migration, division, mutation, selection, and final differentiation have been extensively studied. Thereby, modulations of these mechanisms either optimize the quality, in terms of affinity, or the quantity of generated Abs, but never both, leading to an unclear effect on the overall efficiency of the Ab response. In this article, we predict with mathematical models that an affinity-dependent number of GC B cell divisions overcomes the dichotomy of quality and quantity, and has to be considered as a good target for immune interventions, in particular, in the elderly population with poor GC responses.
Cremona Maps of de Jonquières Type
Authors: Pan Ivan , Simis Aron
Published: October 2014

This paper is concerned with suitable generalizations of a plane de Jonquières map to higher dimensional space ℙn with n ≥ 3. For each given point of ℙn there is a subgroup of the entire Cremona group of dimension n consisting of such maps. We study both geometric and group-theoretical properties of this notion. In the case where n = 3 we describe an explicit set of generators of the group and give a homological characterization of a basic subgroup thereof.
Réémergence de la paramphistomose bovine en France : Synthèse des connaissances actuelles épidémiologiques, physiopathologiques et diagnostiques
Authors: Alzieu Jean-Pierre , Dorchies Philippe
Published: October 2014

The prevalence of cattle paramphistomiasis is growing in France. This recent reemergence may be related to several factors : limited number of specific anthelmintics available, longevity and high prolificity of adult worms, decreasing prevalence liver fluke which increases the availability of the snails which act as intermediate hosts for paramphistomids, and extensification of cattle farming. Although clinical signs are not very typical, the pathogenicity of paramphistomiasis cannot be ignored, due to the risk of acute form due to immature worms (difficult to identify) and of recurrent bloating due to the mechanical effect of adult worms. However, the pathogenicity of paramphistomids is much milder than that of Fasciola hepatica.

There is currently no immunological method available for this diagnosis ; a clinical suspicion is confirmed by faecal egg counts (epg), but there is no formal correlation between their numbers and the parasite load.
La peste des petits ruminants : une maladie longtemps ignorée
Authors: Diallo Adama
Published: October 2014

Après sa première description en 1942 en Côte-d’Ivoire, la peste des petits ruminants (PPR) a longtemps été considérée comme localisée aux pays d’Afrique de l’Ouest. À la suite du développement de tests de diagnostic spécifique à la fin des années 1980, notre connaissance de l’aire de répartition de la maladie a très vite progressé. Il est probable que la PPR ait existé bien avant 1942, mais elle a dû être confondue avec deux autres maladies présentant, dans les mêmes zones enzootiques, des symptômes similaires : la pasteurellose pour les signes respiratoires de bronchopneumonie ou la peste bovine pour la diarrhée et les lésions érosives des muqueuses. Cette dernière est due à un virus apparenté à celui de la peste des petits ruminants. Aujourd’hui, plus d’un milliard de petits ruminants sont menacés par la PPR.
La fièvre du Nil occidental et la fièvre catarrhale ovine, deux viroses en progression inattendue
Authors: Zientara Stéphan , Lecollinet Sylvie , Bréard Emmanuel , Sailleau Corinne , Boireau Pascal
Published: October 2014

This paper describes the spread of two arboviral diseases in Europe, and the control measures implemented by health authorities. Bluetongue, which affects only animals, occurred for the first time in Europe in 1998, and West Nile Fever, which affects horses and humans, re-emerged in 1996. Up until 1998, bluetongue was considered as an exotic disease. In 2006 and 2007, its unexpected explosion in Northern Europe highlighted the emergence and expansion capacities of vector-borne diseases. Surprisingly, the disease became perennial in Europe, rapidly spreading to eight European countries and crossing the English Channel and contaminating several herds in England. Its expansion resulted from vector movements carried over long distances by the wind (100 km), and followed a centrifugal pattern in 2006/2007. By 2008, the bluetongue virus (BTV) was occupying a wider European territory. The only control measure available is vaccination, which has been largely implemented in 2008.

West Nile fever is a viral disease transmitted by mosquitoes, whose amplifying hosts are birds, whereas horses and humans are incidental but particularly sensitive hosts. West Nile fever appeared in Europe in the 60’s and 70’s, especially in the Camargue region of France, with sporadic foci. At the end of the 90’s, besides the introduction and expansion of the virus on the American continent, major epidemics affected several hundreds of people in Europe (Romania in 1996 and Russia in 1999). Since then, four distinct episodes of West Nile virus (WNV) circulation, associated with clinical cases in horses, were reported in France : in the Camargue region in 2000 and 2004, in the Var department in 2003 and in the Eastern Pyrenees in 2006. An increase in WNV activity was observed in Europe in 2008, with cases of infection reported in Italy, Romania, Hungary and Austria. An inactivated vaccine (Fort Dodge) has recently received a marketing agreement from the European commission. However, until now, control measures rely exclusively on a reinforced surveillance of neurological conditions in humans and animals (horses and birds generally), and on information of exposed people.
L'arrêt Riaucourt et ses effets
Authors: Guillemot Pierre , Vandaële Eric
Published: October 2014

L’arrêt Riaucourt du Conseil d’État, daté du 24 janvier 2007, interdit l’exercice de la pharmacie vétérinaire à tout vétérinaire salarié d’un groupement de producteurs, si les médicaments sont achetés et/ou vendus par la structure et non par le vétérinaire qui les a prescrits.

La Direction générale de l’alimentation (DGAL) a publié, le 14 août 2007, une note de service sur les conséquences de l’arrêt Riaucourt. Celle-ci indique aux Directions départementales des services vétérinaires que l’interdiction d’achat et/ou de revente des médicaments vétérinaires par les organismes qui salarient des vétérinaires devait être effective à compter du 1er octobre 2007, pour non seulement :

- les médicaments sur prescription «hors plan sanitaire d’élevage» des groupements agréés,

- mais aussi tous les médicaments pour les haras, les dispensaires des associations de protection animale, les parcs zoologiques et toutes les autres structures non libérales.

Selon la DGAL, trois solutions peuvent être envisagées pour l’activité «hors PSE» des vétérinaires salariés de groupement :

- soit la constitution de sociétés d’exercice libéral de vétérinaires, par ailleurs salariés du groupement et exerçant dans le cadre du plan sanitaire d’élevage, sociétés séparées physiquement, administrativement et juridiquement du groupement ;

- soit la signature d’une convention avec des vétérinaires libéraux existants ;

- soit la délivrance par une pharmacie d’officine d’une prescription par le vétérinaire salarié.
Les virus infectant les mollusques marins: un exemple d'actualité, les herpèsvirus
Authors: Renault Tristan
Published: October 2014

Bien que des épisodes de mortalité associés à la détection de virus aient été rapportés chez différentes espèces de mollusques, peu d’informations sont aujourd’hui disponibles concernant l’affiliation exacte de ces virus et leur position taxinomique. Parmi les virus infectant les coquillages, les herpèsvirus ont fait l’objet d’une attention particulière du fait de leurs impacts économiques et écologiques sur les animaux en élevage et sauvages. Des recherches par des approches de biologie moléculaire ont été menées en France sur le virus infectant les huîtres creuses, Crassostrea gigas. Sur la base des données moléculaires et ultra-structurales, ce virus a été classé, sous le nom d’ostreid

herpesvirus 1 (OsHV-1), comme première espèce virale de la famille Malacoherpesviridae. Depuis 2008, des épisodes de surmortalité ont été rapportés dans différentes régions de production des huîtres creuses C. gigas, en France, en Irlande et au Royaume Uni. Ils ont été attribués à des conditions environnementales défavorables associées à la découverte d’un variant génotypique viral particulier, appelé OsHV-1 μVar.
Physicochemical and biological controls on primary and net community production across northeast Pacific seascapes
Authors: Kavanaugh Maria T. , Emerson Steven R. , Hales Burke , Lockwood Deirdre M. , Quay Paul D. , Letelier Ricardo M.
Published: October 2014

The subarctic–subtropical transition zone in the North Pacific represents the second largest sink of atmospheric carbon dioxide in the world ocean, yet the relative importance of physical and biological processes in this uptake is debated. In a step toward understanding the spatiotemporal variability of environmental, physiological, and ecological factors that contribute to the efficacy of the biological pump, near‐continuous measurements of net primary production (NPP), net community production (NCP), export efficiency (NCP : NPP), and several physiological and ecological variables were collected across subarctic, transition, and subtropical seascapes of the Northeast Pacific during August and September of 2008. Whereas hydrographic variability (e.g., temperature, salinity, and mixed layer) dominated at basin scales, the effects were balanced or subsumed by biomass or taxa effects within individual seascapes. Fluorescence diagnostics suggested that the transition seascape was neither iron nor macronutrient limited. NPP and NCP were strongly spatially coupled in both the transition (r = 0.70; p < 0.0001) and subtropics (r = 0.68, p < 0.0001); however, the strength of individual drivers as determined through multiple linear regression (MLR) varied across seascapes. NPP in the transition seascape was driven primarily by nano‐ and microphytoplankton biomass, whereas NCP appeared to be driven by changes in salinity, temperature, and to a lesser degree, diatom‐specific biomass. Although NPP was low in the subtropics, mesoscale changes in hydrographical factors and shifts in community structure from pico‐ to microphytoplankton contributed to moderate NCP and high export efficiency. Spatial variability in the relative importance of hydrography, phytoplankton community structure, and NPP in driving NCP illuminates regional sensitivity of the biological pump to future climate conditions.
Effects of blade flexural rigidity on drag force and mass transfer rates in model blades
Authors: Rominger Jeffrey T. , Nepf Heidi M.
Published: October 2014

We created a model physical system to investigate the role of blade rigidity in setting forces and rates of mass exchange for a blade exposed to unsteady flow in a vortex street. Using a combination of experimental and theoretical investigations, we find that, broadly, both the forces and the mass exchange are higher for more flexible blades. Below a critical value of the dimensionless blade rigidity, inertial forces from the rapidly deforming blades become significant, increasing both the time‐averaged and instantaneous forces on the blade. Mass transfer is also affected by blade rigidity. As blades deform, they alter the relative fluid motion at the blade surface, affecting mass fluxes. We developed a novel experimental method that simulates nutrient uptake to a blade using the transport of a tracer compound into polyethylene models. Through these experiments and modeling, we demonstrate that increased blade flexibility is associated with increased mass transfer to blades.
Interannual variability of circulation under spring ice in a boreal lake
Authors: Salonen Kalevi , Pulkkanen Merja , Salmi Pauliina , Griffiths Ross W.
Published: October 2014

A small range (∼ 1°C) of under‐ice water temperature is shown to result in remarkably different circulation regimes under spring ice in a deep, oligotrophic boreal lake. With the water column at < 4°C, melting of snow led to deepening vertical convection before ice break and a final depth of convection inversely correlated with earlier deep‐water temperature. We attribute that to the nonlinear dependence of water density on temperature, albeit further affected by stochastic weather factors. In four of nine study years, convection led to complete under‐ice overturn of the lake, indicating that this may not be uncommon in similar lakes with steep topography. River inflow and more intensive warming of water in the littoral zone also created a horizontal density differential, convection that involved flow down the sloping bottom and a lateral intrusion of this sinking water at a depth between the vertical convection and the quiescent deep‐water layers. The vertical and horizontal convection together produced a profile of temperature slightly increasing from the surface to the bottom of the convection layer. The contribution of horizontal convection to under‐ice mixing was interannually variable, and in one of the study years it eventually dominated under‐ice mixing. A thermal bar circulation regime developed occasionally and only in the open water between ice and shoreline. We identified five different under‐ice mixing regimes that form an interannually variable continuum of behavior during the ice melting period. The dependence on a narrow temperature range likely makes the circulation regime sensitive to a warming climate.
The unique trace metal and mixed layer conditions of the Costa Rica upwelling dome support a distinct and dense community of Synechococcus
Authors: Ahlgren Nathan A. , Noble Abigail , Patton Allison P. , Roache‐Johnson Kathryn , Jackson Laurel , Robinson Daniela , McKay Cedar , Moore Lisa R. , Saito Mak A. , Rocap Gabrielle
Published: October 2014

The Costa Rica Dome (CRD) is a wind‐driven upwelling feature in the eastern tropical Pacific that supports unusually high concentrations (> 106 cells mL−1) of the picocyanobacteria Prochlorococcus and Synechococcus. To understand what causes this unusual phytoplankton bloom, we conducted a comprehensive survey of the hydrography, picophytoplankton population structure, and trace metal chemistry of the CRD and surrounding oligotrophic and equatorial upwelling waters. Based on size‐fractionated chlorophyll, picoplankton dominated phytoplankton biomass in the region, and the three water regimes sampled supported different assemblages of Prochlorococcus, Synechococcus, and eukaryotic picophytoplankton. Cobalt (Co), a required nutrient for cyanobacteria, was strongly complexed in surface waters and was at least twice as high in the photic zone of the CRD than in surrounding waters. In contrast, iron (Fe) and manganese (Mn) levels were comparable in and outside the CRD. Synechococcus clades II and CRD1 and Prochlorococcus ecotype eMIT9312 (high light II) were the dominant genotypes throughout the region, as assessed by quantitative polymerase chain reaction assays. The composition of less abundant Synechococcus clade subpopulations differed in and outside the CRD and within the CRD. Co, mixed layer depth, and temperature were the important drivers of both total Synechococcus abundance and cyanobacterial community composition. This supports a model whereby the combination of upwelled macronutrients, high concentrations of complexed Co, and Fe and Mn scarcity in the warm, shallow mixed layer of the CRD limit larger phytoplankton and induce dense concentrations of picocyanobacteria. Globally, we suggest that trace metals influence phytoplankton distributions at both the broad (cyanobacterial vs. eukaryotic) and the fine (ecotype‐level) taxonomic levels.
Stoichiometric imbalance in rates of nitrogen and phosphorus retention, storage, and recycling can perpetuate nitrogen deficiency in highly‐productive reservoirs
Authors: Grantz Erin M. , Haggard Brian E. , Scott J. Thad
Published: October 2014

We measured the nutrient stoichiometry of inputs, outputs, retention, storage, and recycling in three seasonally nitrogen (N)‐deficient reservoirs by incorporating watershed mass balances with measurements of internal N and phosphorus (P) transformations. Our objective was to determine if the reservoirs were accumulating N and thereby likely to develop strict P deficiency over time. For the eutrophic reservoirs, the N : P (by atoms) of annual outputs was two to five times greater than that of inputs, reflecting higher retention efficiency for P than N (∼ 90% vs. ∼ 50%, respectively) and resulting in retention stoichiometry indicative of N deficiency (N : P < 20). The N : P of these fluxes differed less for the mesotrophic reservoir because of similar N and P retention efficiencies, and the N : P of retained nutrients indicated strict P deficiency (N : P > 50). Denitrification (12–23 g N m−2 yr−1) removed ∼ 50–100% of N retained by the reservoirs annually, increasing N deficiency in storage relative to retention for all the reservoirs (N : P < 1–30). The combined effects of more efficient P than N retention and efficient denitrification were also evident in the low N : P (< 10) of internal recycling. N2 fixation (7–11 g N m−2 yr−1) was inefficient in balancing system N deficits and did not increase the low N : P of annual watershed inputs or seasonal epilimnion nutrient concentrations into the range of strict P deficiency. Low N : P storage and internal recycling strongly suggested that these reservoirs are not accumulating N relative to P and are thereby unlikely to become strictly P deficient over time.
Isotopes and elemental ratios in multi‐parameter mixing models
Authors: Loftis Kathy M. , Meile Christof
Published: October 2014

Concentration measurements, stable isotope signatures, and elemental ratios are extensively used as parameters in mixing models to identify the source material contributing to mixtures. Determining these contributions in complex mixtures necessitates the use of multiple tracers. Here, we show that this requires careful selection of the parameters used, and that the common direct use of isotopic signatures or elemental ratios in mixing models when combined with other tracers can lead to erroneous results. We further demonstrate that when the number of available tracers exceeds the number of source materials, finding the fractional contributions that best fit the data may benefit from normalization, and we present a simple measure indicating when the outcome of mixing model calculations is poorly constrained. Finally, as a practical example, we investigated the impact of parameter choices through a reanalysis of literature data on organic matter cycling along the Altamaha River estuary.
Rapid solid phase extraction of dissolved organic matter
Authors: Swenson Michael M. , Oyler Alan R. , Minor Elizabeth C.
Published: October 2014

Dissolved organic matter (DOM) is a complex mixture of molecules found ubiquitously in freshwater and saltwater environments. Its structures contain valuable information content on the sources of molecules as well as the mechanisms at work within an aquatic ecosystem. Recent advancements in high resolution mass spectrometry and liquid chromatography have made inroads into determinations of the molecular structures within DOM. Such analyses, however, generally require a prior step to concentrate/isolate DOM, and this step often limits the number of samples that can be analyzed. This study has developed a fast method to concentrate DOM on commercially available online solid phase extraction (SPE) cartridges, which can be directly eluted onto an HPLC‐MS system. This rapid solid phase extraction (RSPE) method requires less sample (10‐100 mL) than previous SPE methods for DOM isolation. Additionally, this study tested a suite of SPE phases to find a combination that improves DOM recovery as compared with commonly used approaches. When a polystyrene divinylbenzene phase (RP‐1) was coupled with an activated carbon (CAR) phase, recoveries were found to be significantly higher than in previous SPE studies relying upon single phases. RSPE was tested for a diverse set of salty and freshwater samples with recoveries ranging from 46% to 78% of the total DOC. It was also tested on a suite of model compounds (including caffeine) and should be applicable to anthropogenic compounds in aquatic environments, although, in such cases, optimization may be needed to minimize the natural organic matter signal that was maximized in this study.
Delayed responses of an Arctic ecosystem to an extreme summer: impacts on net ecosystem exchange and vegetation functioning
Authors: Zona D. , Lipson D. A. , Richards J. H. , Phoenix G. K. , Liljedahl A. K. , Ueyama M. , Sturtevant C. S. , Oechel W. C.
Published: October 2014

Abstract. The importance and consequences of extreme events on the global carbon budget are inadequately understood. This includes the differential impact of extreme events on various ecosystem components, lag effects, recovery times, and compensatory processes. In the summer of 2007 in Barrow, Arctic Alaska, there were unusually high air temperatures (the fifth warmest summer over a 65-year period) and record low precipitation (the lowest over a 65-year period). These abnormal conditions were associated with substantial desiccation of the Sphagnum layer and a reduced net Sphagnum CO2 sink but did not affect net ecosystem exchange (NEE) from this wet-sedge arctic tundra ecosystem. Microbial biomass, NH4+ availability, gross primary production (GPP), and ecosystem respiration (Reco) were generally greater during this extreme summer. The cumulative ecosystem CO2 sink in 2007 was similar to the previous summers, suggesting that vascular plants were able to compensate for Sphagnum CO2 uptake, despite the impact on other functions and structure such as desiccation of the Sphagnum layer. Surprisingly, the lowest ecosystem CO2 sink over a five summer record (2005–2009) was observed during the 2008 summer (~70% lower), directly following the unusually warm and dry summer, rather than during the extreme summer. This sink reduction cannot solely be attributed to the potential damage to mosses, which typically contribute ~40% of the entire ecosystem CO2 sink. Importantly, the return to a substantial cumulative CO2 sink occurred two summers after the extreme event, which suggests a substantial resilience of this tundra ecosystem to at least an isolated extreme event. Overall, these results show a complex response of the CO2 sink and its sub-components to atypically warm and dry conditions. The impact of multiple extreme events requires further investigation.
Roads at risk – traffic detours from debris flows in southern Norway
Authors: Meyer N. K. , Schwanghart W. , Korup O. , Nadim F.
Published: October 2014

Abstract. Globalization and interregional exchange of people, goods, and services has boosted the importance of and reliance on all kinds of transport networks. The linear structure of road networks is especially sensitive to natural hazards. In southern Norway, steep topography and extreme weather events promote frequent traffic disruption caused by debris flows. Topographic susceptibility and trigger frequency maps serve as input into a hazard appraisal at the scale of first-order catchments to quantify the impact of debris flows on the road network in terms of a failure likelihood of each link connecting two network vertices, e.g., road junctions. We compute total additional traffic loads as a function of traffic volume and excess distance, i.e. the extra length of an alternative path connecting two previously disrupted network vertices using a shortest-path algorithm. Our risk metric of link failure is the total additional annual traffic load expressed as vehicle kilometers because of debris-flow related road closures. We present two scenarios demonstrating the impact of debris flows on the road network, and quantify the associated path failure likelihood between major cities in southern Norway. The scenarios indicate that major routes crossing the central and northwestern part of the study area are associated with high link failure risk. Yet options for detours on major routes are manifold, and incur only little additional costs provided that drivers are sufficiently well informed about road closures. Our risk estimates may be of importance to road network managers and transport companies relying of speedy delivery of services and goods.