bluuebunny/crossref_metadata_2025 huggingface dataset:
Les sans-dot de l'agriculture : faut-il aider les installations sans aide ?
Authors: Rémy Jacques
Published: October 2009

"Dowryless" young farmers : should unaided farm installations be given help?

Unaided farm installations (without a subsidy for young farmers which is called "Dotation Jeune Agriculteur") make up about a third of today's young farmer's installations in France. For several years now, these unaided installations have caught the attention of the media and of agricultural unions. More and more demanding requirements to be eligible for the "Young Farmers Subsidy" also exclude unaided farmers from different forms of aid such as quotas. Nevertheless, they produce, occupy territory, maintain the landscape, and above all, are off welfare. In the present social, political and economic context, the ways of distributing different aids between regions, different forms of production and types of farmers, often create feelings of discrimination and exclusion. In the end, it might be wiser to give out aid more equitably for all active farmers.
L'agriculture "hors" du rural ?
Authors: Wolfer Bernard
Published: October 2009

Le monde agricole s'est longtemps confondu avec le monde rural. Les agriculteurs s'estiment encore détenteurs de l'essentiel de la légitimité rurale. Cette légitimité ne va pourtant plus de soi. Il y a cent ans, l'agriculture occupait et nourrissait un monde essentiellement rural. Espace et activités agricoles et rurales s'entremêlaient : ouvriers, artisans, propriétaires fonciers et paysans éaient les acteurs solidaires et conflictuels d'une société aux multiples paysages, réels et symboliques. L'agriculture moderne a fait éclater cette société. L'agriculteur est devenu un entrepreneur produisant pour des marchés de plus en plus éloignés. Occupé à sa fonction productrice, il a abandonné nombre d'activités d'aménagement et d'entretien des territoires ruraux. Les agriculteurs sont minoritaires dans la population rurale. Les ruraux d'aujourd'hui (ouvriers de l'industrie, employés, cadres, retraités, résidents secondaires) ne partagent plus la culture, encore moins les intérêts des agriculteurs. Ces derniers, affranchis de la nécessité des solidarités locales, sont attentifs aux horizons du marché, moins à ceux du territoire. La rupture est difficile à reconnaître. Remembrements, érosions, pollutions, évolutions des paysages : ces sources de conflits ôtent aux agriculteurs une certaine légitimité à représenter le monde rural. Enfin le territoire rural est marqué par les pouvoirs, publics et privés. Bien que possesseurs majoritaires, les agriculteurs en maîtrisent de moins en moins l'avenir.
Viabilité à moyen et long termes d'un système agraire villageois d'Afrique soudano-sahélienne. Le cas de Bala au Burkina Faso
Authors: Barbier Bruno , Benoit-Cattin Michel
Published: October 2009

Medium and long term viability of the agrarian system of a village in soudano-saheuan Africa. the case of Bala in Burkina Faso

Can african agrarian systems carry on rapidly increasing populations ? To contribute to this debate, a model has been built at the village level in the cotton zone and is used in a recursive way. The maximum of the available information on the zone has been incorporated. Simulations show a crucial threshold when fallow desappear and when it is necessary to combine different techniques for a better management of the soils and of the organic matter ; doing so, a permanent regime could be reach with four times more people but with half the revenue.
Cultures d'exportation et cultures vivrières au Cameroun
Authors: Fadani Andréa , Temple Ludovic
Published: October 2009

La pression démographique des pays africains implique d'augmenter en même temps les cultures d'exportation et vivrières toutes deux nécessaires à la sécurité alimentaire. Ce travail, par une utilisation d'enquêtes et une modélisation des systèmes de production cacaoyer et caféier au Cameroun teste les conditions de réalisation de ce défi. Il révèle que les complémentarités entre cultures sont basées sur l'exploitation du capital agro-écologique. Il montre en quoi les contraintes de liquidité bloquent une intensification en intrants. Il explique comment les conditions de production des vivriers déterminent le prix implicite du travail, et en quoi ce prix est un facteur de la compétitivité des cultures d'exportation.
Détermination des objectifs économiques des petits producteurs de café au Guatemala
Authors: Carlos Méndez Juan , Benoit-Cattin Michel
Published: October 2009

Sur la base d'une typologie articulant le niveau d'intensification de la production et la structure des exploitations familiales, cette étude a pour objectif d'identifier les critères de décision technico-économiques propres à chaque type d'exploitation ciblé par la vulgarisation agricole. La méthode utilisée est la modélisation par programmation mathématique des systèmes de production complétée par la technique du Multiple Criteria Decision Making (mcdm) appliquée à des exploitations préalablement typées. L'objectif principal des exploitations ne serait la maximisation de la marge brute que dans le cas des exploitations des "Jeunes". Les "Capitalisés" maximisent la rentabilité, les "Diversifiés" minimisent les charges variables et les "Traditionnels" minimisent la difficulté de gestion. Ces résultats peuvent permettre une meilleure sélection des propositions techniques faites aux exploitants.
Scénario pour un élargissement à l'Est de l'Union européenne
Authors: Cazes Sandrine , Coquet Bruno , Lerais Frédéric
Published: October 2009

Scenario for an eastern enlargement of the EU

An enlargement of the eu to Central and Eastern European Countries (CEECS), would constitute an unprecedented change : ceecs transitions are underway, and eu is currently facing major transformations, reforms, uncertainties and challenges. This paper intend to evaluate macroeconomic consequences of an enlargement, with the International Macroeconomic Model Mimosa. Our study shows that an eastern enlargement would have beneficial macroeconomic consequences relatively modest for the EU current members, but quite substantial for the newcomers. It appears that trade openness and financing are essential for the success of an enlargement process. An increase in Structural Funds currently allowed to the CEECS -relatively modest for the current eu members- would greatly foster more rapid and sustained growth in these countries, and in the rest of Europe, so that the additional transfers would soon be self-financing. This study shows that obstacles to enlargement process do not come from economic difficulties, but mainly stems from political and strategical issues.
L'intégration des pays d'Europe centrale et orientale à l'Union européenne
Authors: Maurel Mathilde , cheikbossian Guillaume , Schumacher Dieter
Published: October 2009

The integration of PECO's in UE

The Central Eastern European trade represents a little amount of total European trade : it is less than 1 % of French and German gnp. But in some sectors, the export of Eastern Europe can reach 10 %-20 % of total European import. Thanks to the trade liberalisation process, a significant trade reorientation has taken place, but barriers remain in the sensitive sectors, where the Central Eastern European countries (CEEC's) may have comparative advantages. Although positive (new markets do not compensate for the CMEA trade collapse), the disintegration cost of cmea is decreasing. The analysis of trade at a disaggregated level reveals the sectors where CEEC's have comparative advantages. By estimating the factor content of Eastern European exports, it can been shown that they embody more labour than imports from Western Europe.
Production porcine en Pologne, République tchèque et Hongrie. Les perspectives après le choc de la transition
Authors: Rieu Michel
Published: October 2009

Pig production in Poland, Czech Republic and Hungary. Which future after economic transition ?

The pig production, as the whole agriculture, suffered during the political and economical changes in central and eastern Europe. In the three countries observed, the lack of money is the main obstacle for maintaining or adapting the pig production. First country in pig production, Poland had always private and very small farms, even under the communist system. The pig herd is now the same as in 1989, but its technological level is still very bad. The communist structure of the Czech pig industry suffered very hardly of financial problems in the last years. In Hungary, first exporter, the pig livestock has fallen by 50 % because the loss of the soviet market and the structural changes. The fall is now stopped, but the recovery will be very difficult.
L'intégration des PECO à la nouvelle PAC. Une double révolution inachevée
Authors: Blanchet Jacques , Revel Alain , Linglin alexandra , Kosciusko-Morizet Nathalie , Wormser Véronique
Published: October 2009

The EU enlargement to the ceecs : an unacomplished double revolution

The CEECs own two third of the EU 12 grain land. The production of grains, oilseeds, potatoes, fruits, vegetables, dairy and pork products is significant. Not following the China's example of 1978, the 1990 agricultural revolution has not braught any farm production increase, but on the contrary, a one third decrease. The kolkhozian structures have been maintained under an other name. This unacomplished revolution of the ceecs' side force the reformed cap of 1992 to a new evolution, perhaps unavoidable for other reasons. So, the new extension of European Union will not be like the preceeding ones. Two great options are open : does cap be reformed again before its widening towards East countries ? What position to adopt towards production subsidies which became the base of the new policy ?
Exploitations agricoles et protection de la qualité de l'eau. Analyse d'un processus d'adaptation
Authors: Brossier Jacques , Gafsi Mohamed
Published: October 2009

Les exploitations agricoles doivent s'adapter pour tenir compte de la nécessaire protection de l'environnement. A partir d'une situation de protection d'un périmètre d'eau minérale associant une entreprise privée et des agriculteurs, nous proposons une analyse économique d'un processus d'adaptation dans plusieurs exploitations. L'analyse indique une tendance à la spécialisation des systèmes de production et une amélioration des résultats économiques grâce aux moyens de production mis à la disposition des agriculteurs et à l'existence d'une structure d'accompagnement.
Politiques « horizontales » et politiques territoriales des structures agricoles. L'exemple de la Bourgogne
Authors: Daucé Pierre
Published: October 2009

Cet article compare les deux modalités de l'intervention publique sur les structures agricoles mises en place par l'Union européenne : celle qui relève de l'objectif 5a et celle qui s'insère dans l'objectif 5b de la réforme des fonds structurels européens. Selon des observations réalisées en Bourgogne entre 1991 et 1993, il apparaît que la politique structurelle classique reste la plus importante quantitativement ; c'est celle dont l'impact est le plus reconnu et le plus significatif. La politique agricole territorialisée, dans sa première phase de mise en œuvre, éprouve quelques difficultés à se différencier et n'apparaît souvent que comme un complément aux mesures habituelles. Elle touche cependant dans certaines zones un public élargi d'agriculteurs et elle amorce des initiatives et des comportements qui peuvent s'avérer porteurs d'avenir pour une meilleure intégration de l'agriculture dans le développement des activités rurales.
Nouvelle PAC L'exploitation agricole de grande culture en Ile-de-France de 1991 à 1995
Authors: Carles Roland , Millet Guy
Published: October 2009

Les exploitations spécialisées de grande culture ont été directement concernées par la réforme de la PAC suite aux décisions de 1992. Il est intéressant de comparer leur situation avant la réforme et après la réforme : 1991 est la dernière année d'application de l'ancienne PAC et 1995 l'année la plus récente pour laquelle on dispose d'un certain nombre d'informations. Il est également intéressant d'analyser les écarts existant entre ce qui avait été prévu et ce qui s'est réalisé. En s'appuyant sur la modélisation d'une exploitation-type de l'Ile-de-France, on examine ce qui s'est passé : un niveau des prix plus élevé que prévu, l'importance de l'agrandissement des exploitations, les économies de charges réalisées, les variations du taux de jachère et l'effet de quelques autres facteurs de moindre importance.
Groupes domestiques et recomposition sociale de l'agriculture. Le cas des micro-exploitations agricoles du piémont pyrénéen
Authors: Coutureau Gérard
Published: October 2009

Le maintien relatif de micro-exploitations, étudiées dans une zone précise du piémont pyrénéen, peut s'expliquer par la diversité des stratégies agricoles adoptées par les groupes domestiques qui vivent sur ces micro-exploitations ; si certaines d'entre elles restent dans des systèmes d'élevage traditionnels, d'autres diversifient leurs activités d'exploitation vers des activités de transformation, de commercialisation et de services. Ces stratégies diversifiées reflètent les changements sociaux et économiques observés dans les groupes domestiques.
Le péri-urbain en Afrique : une agriculture en marge ?
Authors: Moustier Paule , Pages Jacques
Published: October 2009

En Afrique, l'agriculture périurbaine constitue une source très importante de revenus et d'alimentation pour les citadins défavorisés. Or cette activité est soumise à de nombreuses contraintes, au premier rang desquelles la pression foncière. Les zones agricoles plus éloignées de la ville peuvent constituer une alternative à l'approvisionnement en vivres par le périurbain. Comme le montre le cas de l'approvisionnement de Brazzaville en légumes, les zones rurales et périurbaines sont en fait complémentaires : les légumes-feuilles et les légumes de type tempéré proviennent du périurbain, tandis que les légumes-fruits de type local proviennent des champs villageois. Les contraintes de terrain, mais également de transport, d'accès aux intrants et à l'appui technique sont déterminantes dans la localisation des productions. Enfin, l'analyse historique permet d'infirmer des hypothèses d'évolution linéaire de la production périurbaine vers le déclin ou l'expansion via l'intensification.
La ruralité : diversité des approches
Authors: Blanc Michel
Published: October 2009

Cet article cherche à éclairer comment le rural peut être conceptualisé. La thèse défendue est qu'il n'y a pas un concept de rural, mais une diversité de façon de le construire qui renvoie a autant de manières de questionner l'hétérogénéité de l'espace. À titre d'illustration, trois types de problématiques de l'espace sont examinés.
Gestion de l'emploi dans les entreprises rurales et fonctionnement du marché du travail
Authors: Aubert Francis
Published: October 2009

L'analyse de l'emploi en milieu rural est ici centrée sur les pratiques de gestion du travail dans les entreprises industrielles. Pour en conduire l'étude en relation avec le fonctionnement du marché du travail, nous supposons que les forces qui organisent les échanges varient dans l'espace ou, tout au moins, s'expriment diversement selon le contexte territorial d'implantation des agents. En utilisant une démarche de type institutionnaliste, il s'agit de rechercher les mécanismes ayant une dimension territoriale qui produisent une segmentation du marché du travail. Après la présentation des deux modèles retenus, qui relèvent d'une logique « industrielle » et « paternaliste », et leur déclinaison en termes de gestion de la main-d'œuvre, les résultats d'une enquête conduite auprès d'établissements industriels implantés en Bresse bourguignonne, sont exploités pour apprécier les pratiques qui touchent à la relation d'emploi. Des éléments de gestion paternaliste apparaissent, qui permettent d'en actualiser les termes dans les petites entreprises des industries traditionnelles et ouvrent des voies d'analyse de la segmentation du marché.
Les enjeux de l'approche géographique de l'exclusion sociale
Authors: Mathieu Nicole
Published: October 2009

Face à l'intensité du discours sur l'exclusion et la « fracture sociale », il est important pour le géographe de réfléchir sur les apports de sa démarche, l'analyse des rapports sociétés/espaces, pour la compréhension comme pour le traitement de cette question sociale. La réflexion que propose cet article repose à la fois sur un état des lieux bibliographique et sur une recherche sur l'exclusion en milieu rural effectuée en coordination avec les Missions Locales Rurales dans trois territoires ruraux de leur action (Centre Manche, Lubéron, Morvan).
Rapport à l'emploi et processus d'exclusion dans les espaces ruraux : un cadre d'analyse
Authors: Perrier-Cornet Philippe , Sencébé Yannick , Sylvestre Jean-Pierre
Published: October 2009

Le processus d'exclusion ne peut être analysé indépendamment des mécanismes de socialisation professionnelle, parce que le rapport au travail est un élément central de la construction identitaire dans nos sociétés. Dans le cas des espaces ruraux, le problème de l'exclusion est abordé à partir de l'hypothèse que ses manifestations n'y sont pas uniformes et qu'elles ne sont pas réductibles à une simple extension, plus ou moins importante, de phénomènes urbains. Il ne s'agit pas non plus de phénomènes spécifiques qui correspondraient seulement à l'aggravation de situations de pauvreté et de précarité dans les sociétés rurales.
L'agriculture dans l'espace rural. Quelles demandes pour quelles fonctions ?
Authors: Beuret Jean-Eudes
Published: October 2009

L'explicitation des attentes de la collectivité en terme de qualité de l'espace rural intéresse une agriculture en quête de nouvelles fonctions. Des enquêtes nous ont permis de suivre la construction de la demande sociale à partir de demandes privées latentes, exprimées puis socialisées dans diverses organisations. Elles révèlent le fait que les acteurs de la demande se réfèrent à des représentations communes, qui précisent quelles fonctions sont attribuées aux agriculteurs en terme de gestion de l'espace et qui est reconnu apte à évaluer les actes de l'agriculteur dans ce domaine : elles déterminent le contenu des demandes mais expliquent aussi leur fréquente non-expression. Ces représentations apparaissent comme des conventions implicites qui sont le support et le produit d'un mode de coordination en situation d'échange non-marchand, entre une offre résultant d'effets de l'agriculture sur l'espace agricole et les demandes issues des usagers. L'observation des lacunes de ce mode de coordination apporte des enseignements pour l'action publique.
Person-Environment Interactions Contributing to Nursing Home Resident Falls
Authors: Hill Elizabeth E. , Nguyen Tam H. , Shaha Maya , Wenzel Jennifer A. , DeForge Bruce R. , Spellbring Ann Marie
Published: October 2009

Although approximately 50% of nursing home residents fall annually, the surrounding circumstances remain inadequately understood. This study explored nursing staff perspectives of person, environment, and interactive circumstances surrounding nursing home falls. Focus groups were conducted at two nursing homes in the mid-Atlantic region with the highest and lowest fall rates among corporate facilities. Two focus groups were conducted per facility: one with licensed nurses and one with geriatric nursing assistants. Thematic and content analysis revealed three themes and 11 categories. Three categories under the Person theme were Change in Residents' Health Status, Decline in Residents' Abilities, and Residents' Behaviors and Personality Characteristics. There were five Nursing Home Environment categories: Design Safety, Limited Space, Obstacles, Equipment Misuse and Malfunction, and Staff and Organization of Care. Three Interactions Leading to Falls categories were identified: Reasons for Falls, Time of Falls, and High-Risk Activities. Findings highlight interactions between person and environment factors as significant contributors to resident falls.
Pathogen‐Mimicking MnO Nanoparticles for Selective Activation of the TLR9 Pathway and Imaging of Cancer Cells
Authors: Shukoor Mohammed Ibrahim , Natalio Filipe , Tahir Muhammad Nawaz , Wiens Matthias , Tarantola Marco , Therese Helen Annal , Barz Matthias , Weber Stefan , Terekhov Maxim , Schröder Heinz C. , Müller Werner E. G. , Janshoff Andreas , Theato Patrick , Zentel Rudolf , Schreiber Laura Maria , Tremel Wolfgang
Published: October 2009

Here, design of the first pathogen‐mimicking metal oxide nanoparticles with the ability to enter cancer cells and to selectively target and activate the TLR9 pathway, and with optical and MR imaging capabilities, is reported. The immobilization of ssDNA (CpG ODN 2006) on MnO nanoparticles is performed via the phosphoramidite route using a multifunctional polymer. The multifunctional polymer used for the nanoparticle surface modification not only affords a protective organic biocompatible shell but also provides an efficient and convenient means for loading immunostimulatory oligonucleotides. Since fluorescent molecules are amenable to photodetection, a chromophore (Rhodamine) is introduced into the polymer chain to trace the nanoparticles in Caki‐1 (human kidney cancer) cells. The ssDNA coupled nanoparticles are used to target Toll‐like receptors 9 (TLR9) receptors inside the cells and to activate the classical TLR cascade. The presence of TLR9 is demonstrated independently in the Caki‐1 cell line by western blotting and immunostaining techniques. The magnetic properties of the MnO core make functionalized MnO nanoparticles potential diagnostic agents for magnetic resonance imaging (MRI) thereby enabling multimodal detection by a combination of MR and optical imaging methods. The trimodal nanoparticles allow the imaging of cellular trafficking by different means and simultaneously are an effective drug carrier system.
Electronic Structure and Geminate Pair Energetics at Organic–Organic Interfaces: The Case of Pentacene/C60 Heterojunctions
Authors: Verlaak Stijn , Beljonne David , Cheyns David , Rolin Cedric , Linares Mathieu , Castet Frédéric , Cornil Jérôme , Heremans Paul
Published: October 2009

Organic semiconductors are characterized by localized states whose energies are predominantly determined by electrostatic interactions with their immediate molecular environment. As a result, the details of the energy landscape at heterojunctions between different organic semiconductors cannot simply be deduced from those of the individual semiconductors, and they have so far remained largely unexplored. Here, microelectrostatic computations are performed to clarify the nature of the electronic structure and geminate pair energetics at the pentacene/C60 interface, as archetype for an interface between a donor molecule and a fullerene electron acceptor. The size and orientation of the molecular quadrupole moments, determined by material choice, crystal orientation, and thermodynamic growth parameters of the semiconductors, dominate the interface energetics. Not only do quadrupoles produce direct electrostatic interactions with charge carriers, but, in addition, the discontinuity of the quadrupole field at the interface induces permanent interface dipoles. That discontinuity is particularly striking for an interface with C60 molecules, which by virtue of their symmetry possess no quadrupole. Consequently, at a pentacene/C60 interface, both the vacuum‐level shift and geminate pair dissociation critically depend on the orientation of the pentacene π‐system relative to the adjacent C60.
Light‐Triggered Self‐Assembly of a Spiropyran‐Functionalized Dendron into Nano‐/Micrometer‐Sized Particles and Photoresponsive Organogel with Switchable Fluorescence
Authors: Chen Qun , Feng Yu , Zhang Deqing , Zhang Guanxin , Fan Qinghua , Sun Shuna , Zhu Daoben
Published: October 2009

The synthesis, self‐assembly, and spectroscopic investigations of spiropyran (SP)‐functionalized dendron 1 are reported. Under UV light irradiation, assembly of 1 into nano‐/microparticles occurs due to the transformation of the closed form of SP into the open merocyanine (MC) form. The formation of these nano‐/microparticles is confirmed by transmission electron microscopy (TEM) and dynamic light scattering (DLS) experiments in addition to the confocal laser scanning microscopy (CLSM) measurements. These nano‐/microparticles exhibit relatively strong red emission. It is interesting to note that the direct cooling of the toluene/benzene solution of 1 to 0 °C leads to gel formation. Multivalent π–π interactions due to the dendron in 1 may be the driving‐force for the gelation. The UV light irradiation cannot destroy the gel phase, and in fact, the gel–gel transition is successfully realized. The purple‐blue gel exhibits relatively strong red fluorescence; moreover, the fluorescence can be reversibly switched by alternating UV and visible light irradiation. The results clearly indicate that the MC form after aggregation becomes more stable and fluorescent.
Study on the structure and properties of conductive silicone rubber filled with nickel‐coated graphite
Authors: Zou Hua , Zhang Liqun , Tian Ming , Wu Sizhu , Zhao Suhe
Published: October 2009

In this study, the conductive silicone rubber composites filled with nickel‐coated graphite (NCG) have been prepared, and their morphology structure, electrical conductivity, electromagnetic interference shielding efficiency (EMI SE), and mechanical properties have been investigated with reference to the NCG filler loading. The mechanical strength of NCG particle was poor that it can be easily ground into smaller particle during the mixing process if the shear force during mixing is large enough. The electrical conductivity of the composites existed an obvious threshold value with the variation of the loading amount of the conductive filler. EMI SE of the composites increases with the decrease of the volume electrical resistivity. The Payne effect can be used to characterize the intensity of the three‐dimensional conductive network structure in silicone rubber matrix, and the difference of storage modulus in the low and high shear strain has good linear correlation with the electrical conductivity. So, the electrical conductivity and EMI SE can be estimated by means of the difference of storage modulus obtained from rubber process analysis test. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Oxygen barrier coating deposited by novel plasma‐enhanced chemical vapor deposition
Authors: Jiang Juan , Benter Maike , Taboryski Rafael , Bechgaard Klaus
Published: October 2009

We report the use of a novel plasma‐enhanced chemical vapor deposition chamber with coaxial electrode geometry for the SiOx deposition. This novel plasma setup exploits the diffusion of electrons through the inner most electrode to the interior samples space as the major energy source. This configuration enables a gentle treatment of sensitive materials like low‐density polyethylene foils and biodegradable materials. SiOx coatings deposited in the novel setup were compared with other state of the art plasma coatings and were found to possess equally good or better barrier properties. The barrier effect of single‐layer coatings deposited under different reaction conditions was studied. The coating thickness and the carbon content in the coatings were found to be the critical parameters for the barrier property. The novel barrier coating was applied on different polymeric materials, and it increased the barrier property of the modified low‐density polyethylene, polyethylene terephthalate, and polylactide by 96.48%, 99.69%, and 99.25%, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Characterization of polymeric fibers as reinforcements of cement‐based composites
Authors: Jamshidi M. , Karimi M.
Published: October 2009

In this study, three polymeric fibers (nylon 66, polypropylene, and acrylic) were used to improve the flexural and tension strength of cementitious materials. To characterize the performance of these fibers in a cement matrix, scanning electron microscopy, optical microscopy, dynamic mechanical analysis, tensile strength testing, and alkali resistance test were employed. The performance of cement‐based composites containing the fibers was evaluated with a flexural strength test. The results indicated that the flexural strength increased with an increasing number of interfacial interactions between the fibers and cement. This finding was supported by dynamic mechanical analysis data. This has great application potential for fibers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
The influence of fiber fineness on physical characteristics of staple polypropylene fibers spun at different pumping speeds
Authors: Zarrebini M. , Mahmoudi M. R. , El‐Bakary M. A. , El‐Dessouky H. M. , Lawrence C. A.
Published: October 2009

Melt spinning and pump speed conditions are described for five samples of staple polypropylene PP fibers of different fineness. The influence of fiber fineness or denier on the physical characteristics of staple PP fibers spun at different pump speeds was studied. Optical anisotropy was measured using two‐beam interference microscopy. Enthalpy and degree of crystallinity were measured using differential scanning calorimetry technique for studied fibers. The relation between the fiber diameter, crimp ratio, tenacity, and degree of orientation with the fiber denier are given. A selection of microinterferograms of fibers is given for illustration. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Postconsumer high‐density polyethylene/agave fiber foamed composites coated with chitosan for the removal of heavy metals
Authors: Vázquez M. O. , Herrera V. S. , Gómez C. , Gómez‐Salazar S. , Rodrigue D. , González‐Núñez R. , Luna‐Barcenas J. G. , Mani‐González P. G. , Herrera‐Gomez A.
Published: October 2009

Composites of postconsumer high‐density polyethylene with agave fiber were prepared by single‐screw extrusion with azodicarbonamide as a foaming agent to increase the surface area; the composite pellets were coated with chitosan afterward. A chemical pretreatment was applied to the pellets to enhance the chitosan gel compatibility. The adsorption capacities of the composites coated with chitosan were evaluated for Cd(II) and Cu(II) removal from aqueous solutions. The coated composites were characterized by scanning electron microscopy, attenuated total reflectance infrared spectroscopy, and X‐ray photoelectron spectroscopy. Atomic absorption spectroscopy was used to measure metal uptake in batch adsorption studies. The results of this study demonstrated the composites' ability to immobilize chitosan on their surfaces and their capacity to adsorb metal ions. The equilibrium isotherms for Cd(II) and Cu(II) adsorption on the chitosan‐coated composites were described by the Langmuir model. This material represents an attractive low‐cost recycled material for adsorbing metal ions from polluted waters. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis of copper chloride and cobalt chloride doped polyanilines and their magnetic and alternating‐current transport properties
Authors: Gupta K. , Chakraborty G. , Ghatak S. , Jana P. C. , Meikap A. K.
Published: October 2009

Polyaniline (PANI) was synthesized by the well‐known oxidative polymerization of aniline with ammonium peroxodisulfate as the oxidant. The morphological, structural, thermal, optical, magnetic, and electrical properties were characterized with scanning electron microscopy, X‐ray diffraction, Fourier transform infrared, thermogravimetric analysis, differential scanning calorimetry, ultraviolet–visible spectroscopy, room‐temperature magnetic measurements, and low‐temperature electrical transport measurements by the standard four‐probe method. Greater thermal stability and crystallinity were observed in doped PANI versus pure PANI. Magnetic measurements showed that the magnetic susceptibility was field‐dependent. Positive and negative susceptibility values were observed. This may have been due to the interactions of magnetic ions among interchains or intrachains of the polymer matrix. The alternating‐current (ac) conductivity was measured in the temperature range of 77–300 K in the frequency range of 20 Hz to 1 MHz. The frequency‐dependent real part of the complex ac conductivity was found to follow the universal dielectric response: σ′(f) ∝ fs [where σ′(f) is the frequency‐dependent total conductivity, f is the frequency, and s is the frequency exponent] The trend in the variation of the frequency exponent with temperature corroborated the fact that correlated barrier hopping was the dominant charge‐transport mechanism for PANI–CoCl2. An anomalous dependence on temperature of the frequency exponent was observed for PANI–CuCl2. This anomalous behavior could not be explained in terms of existing theories. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Microstructure and mechanism study of polylactide obtained by the copolymerization of L‐lactide and D,L‐lactide
Authors: Zhao Peng , Wang Qin‐Feng , Zhong Qian , Zhang Nai‐Wen , Ren Jie
Published: October 2009

The stereosequence of polylactide has been analyzed with 13C‐NMR spectroscopy, according to which syndiotactic addition is preferred. According to Markovian statistics, the reactivity ratio, which determines the extent of the syndiotactic stereosequence in the polymer chain, can be calculated by an analysis of the carbonyl and methine regions in the spectra. Moreover, the average lengths of segments SS and RR can be proposed and calculated with the distributing function of the sequence. On this basis, we have investigated the formation mechanism with respect to the preference for the syndiotactic addition of polylactide chains. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation, structural development, and mechanical properties of microfibrillar composite materials based on polyethylene/polyamide 6 oriented blends
Authors: Dencheva Nadya , Oliveira M. Jovita , Carneiro Olga S. , Pouzada António S. , Denchev Zlatan
Published: October 2009

The preparation of microfibrillar composites (MFCs) based on oriented blends of polyamide 6 (PA6) and high‐density polyethylene (HDPE) is described. By means of conventional processing techniques, the PA6 phase was transformed in situ into fibrils with diameters in the upper nanometer range embedded in an isotropic HDPE matrix. Three different composite materials were prepared through the variation of the HDPE/PA6 ratio with and without a compatibilizer: MFCs reinforced by long PA6 fibrils arranged as a unidirectional ply; MFCs containing middle‐length, randomly distributed reinforcing PA6 bristles; and a nonoriented PA6‐reinforced material in which the PA6 phase was globular. The evolution of the morphology in the reinforcing phase (e.g., its visible diameter, length, and aspect ratio) was followed during the various processing stages as a function of the blend composition by means of scanning electron microscopy. Synchrotron X‐ray scattering was used to characterize selected unidirectional ply composites. The presence of transcrystalline HDPE was demonstrated in the shell of the reinforcing PA6 fibrils of the final MFCs. The impact of the compatibilizer content on the average diameter and length of the fibrils was assessed. The influence of the reinforcing phase on the tensile strength and Young's modulus of the various composites was also evaluated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Impact of recreational power boating on two populations of northern map turtles (Graptemys geographica)
Authors: Bulté G. , Carrière M.‐A. , Blouin‐Demers G.
Published: October 2009

Recreational power boating is growing in popularity in North America. This activity is known to have lethal and sub‐lethal effects on aquatic wildlife and freshwater turtles may be particularly sensitive to this activity.

This study reports on patterns of traumatic injuries inflicted by powerboat propellers to northern map turtles (Graptemys geographica) from two sites differing in boat traffic intensity in Ontario, Canada.

The relative vulnerability of turtles was assessed, in light of seasonal patterns in boat traffic, as a function of sex‐ and age‐specific movement patterns, habitat use, and basking behaviour obtained by radio‐telemetry. Population viability analyses (PVA) were also conducted to evaluate the potential demographic consequences of mortality induced by powerboats.

The prevalence of propeller injuries was two to nine times higher in adult females than in adult males and juvenile females. Patterns of movement, habitat use, and aquatic basking indicated that adult females are more exposed to collisions with boats. PVA showed that boat‐induced mortality in adult females could lead to rapid population extinction if the risk of mortality when hit by a boat is greater than 10%.

The results of this study showed that recreational power boating is a serious threat to northern map turtles, even under moderate boat traffic. The need to adopt measures restricting boat traffic in areas important to turtles is discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Safety and efficacy of transradial aortoiliac interventions
Authors: Staniloae Cezar S. , Korabathina Ravikiran , Yu Jennie , Kurian Damian , Coppola John
Published: October 2009

Background: This study compares transradial approach (TRA) aortoiliac angioplasty/stenting to the transfemoral approach (TFA). Methods: We reviewed our peripheral database for aortoiliac interventions performed between 2007 and 2009. Demographics, clinical characteristics, procedural, and lesion details were collected. The efficacy endpoints included procedural success, ankle‐brachial index (ABI) improvement, and time to discharge. The safety endpoints were as follows: occurrence of intra‐/periprocedural complications, 30‐day MACE, and access‐site complications (minor/major). The subjects were divided into two groups, TRA and TFA, and compared using appropriate statistics. Results: Twenty‐seven patients had 33 lesions treated via TRA, and 41 patients had 47 lesions treated via TFA access. Baseline demographic differences between the TRA and TFA groups were similar, including mean Rutherford category (2.9 vs. 2.6, P = 0.31) and preintervention ABI (0.64 vs. 0.67, P = 0.80). There was a significantly higher percentage of total occlusions in the TRA group (27.3 vs. 8.5%, P = 0.03). Dye use (238 vs. 213 mL, P = 0.35) and fluoroscopy time (30 vs. 27 min, P = 0.60) were similar. Procedural success rate was similar (87.9 vs. 97.8%, P = 0.15), as well as the improvement in mean ABI (TRA: 0.64–0.77 and TFA: 0.67–0.85, P = 0.77). The time to discharge was significantly shorter for the TRA group (14.4 vs. 20.9 hr, P = 0.003). There were no 30‐day MACE or major access‐site complications, but minor access‐site complications were lower in the TRA group (0.0 vs. 7.3%, P = 0.28), although nonsignificant. Conclusions: The TRA to aortoiliac interventions is as safe and effective as the TFA with the advantage of a lower rate of access‐site complications and shorter hospitalization time. © 2009 Wiley‐Liss, Inc.
Achieving High Affinity towards a Bacterial Lectin through Multivalent Topological Isomers of Calix[4]arene Glycoconjugates
Authors: Cecioni Samy , Lalor Ruth , Blanchard Bertrand , Praly Jean‐Pierre , Imberty Anne , Matthews Susan E. , Vidal Sébastien
Published: October 2009

A family of seven topologically isomeric calix[4]arene glycoconjugates was prepared through the synthesis of a series of alkyne‐derivatised calix[4]arene precursors that are suitable for the attachment of sugar moieties by microwave‐assisted copper(I)‐catalysed azide–alkyne cycloaddition (CuAAC). The glycoconjugates thus synthesised comprised one mono‐functionalised derivative, two 1,2‐ or 1,3‐divalent regioisomers, one trivalent and three tetravalent topoisomers in the cone, partial cone or 1,3‐alternate conformations. The designed glycoconjugates were evaluated as ligands for the galactose‐binding lectin PA‐IL from the opportunistic bacterium Pseudomonas aeruginosa, a major causative agent of lung infections in cystic fibrosis patients. Binding affinities were determined by isothermal titration calorimetry (ITC), and the interaction with the lectin was shown to be strongly dependant on both the valence and the topology. Whereas the trivalent conjugate displayed enhanced affinity when compared to a monosaccharide model, the tetravalent conjugates are to‐date the highest‐affinity ligands measured by ITC. The topologies presenting carbohydrates on both faces of calixarene are the most potent ones with dissociation constants of approximately 200 nM. Molecular modelling suggests that such a multivalent molecule can efficiently chelate two of the binding sites of the tetrameric lectin; this explains the 800‐fold increase of affinity achieved by the tetravalent molecule. Surface plasmon resonance (SPR) experiments confirmed that this glycoconjugate is the strongest inhibitor for binding of PA‐IL to galactosylated surfaces for potential applications as an anti‐adhesive agent.
Linkage Isomerism and Spin Frustration in Heterometallic Rings: Synthesis, Structural Characterization, and Magnetic and EPR Spectroscopic Studies of Cr7Ni, Cr6Ni2, and Cr7Ni2 Rings Templated About Imidazolium Cations
Authors: Boeer Angelika B. , Collison David , Muryn Christopher A. , Timco Grigore A. , Tuna Floriana , Winpenny Richard E. P.
Published: October 2009

The synthesis and structural characterization of three heterometallic rings templated about imidazolium cations is reported. The compounds are [2,4‐DiMe‐ImidH][Cr7NiIIF8(O2CtBu)16] 1 (2,4‐DiMe‐ImidH=the cation of 2,4‐dimethylimidazole), [ImidH]2[Cr6NiII2F8(O2CCtBu)16] 2 (ImidH=the cation of imidazole), and [1‐Bz‐ImidH]2 [Cr7NiII2F9(O2CtBu)18] 3 (1‐Bz‐ImidH=the cation of 1‐benzylimidazole). The structures show the formation of octagonal arrays of metals for 1 and 2 and a nonagon of metal centers for 3. In all cases the edges of the polygon are bridged by a single fluoride and two pivalate ligands, and the position of the divalent metal centers cannot be distinguished by X‐ray diffraction. Magnetic studies combined with EPR spectroscopy allow the characterization of the magnetic states of the compounds. In each case the exchange is antiferromagnetic with a magnetic exchange parameter J≈−5.8 cm−1, and it is not possible to differentiate the exchange between two CrIII centers (JCrCr) from the exchange between a CrIII and a NiII center (JCrNi). For 2 there is evidence for the presence of at least two, possibly four, linkage isomers of the heterometallic ring, caused by the presence of two divalent metal centers in the ring. The EPR spectroscopy of 3 suggests an S=1/2 ground state of the ring and that it is likely that only one linkage isomer is present.
Service‐oriented middleware for financial Monte Carlo simulations on the cell broadband engine
Authors: Rotaru T. , Dalheimer M. , Pfreundt F.‐J.
Published: October 2009

Financial Monte Carlo simulations are computationally intensive applications that must meet tight deadlines in terms of job completion times. The completion time might have a huge impact on the financial profits made from decisions derived from the simulation results. Naturally, there is a huge interest in being able to simulate as fast as possible. While single simulations can be done on one machine, decisions often depend on portfolios of simulations. Distributing the workload among resources is crucial to achieve low latency. In this article we present a combination of a middleware with a high‐performance implementation of an Asian options evaluation code on the Cell Broadband Engine (CBE). We handle workload distribution with our PHASTGrid middleware and provide users with a web service interface to the whole infrastructure. The CBE is particularly suitable for Monte Carlo simulations. We implemented a well‐known algorithm on both the CBE and the Intel x86 multicore architectures. Both codes are integrated in our middleware, allowing a direct comparison of the performance and scalability. In addition to the Monte Carlo simulation, we also use different applications and compare our middleware with Globus. Copyright © 2009 John Wiley & Sons, Ltd.
Graph grammar‐driven parallel partial differential equation solver
Authors: Paszyński Maciej , Schaefer Robert
Published: October 2009

The paper presents an extension of the composite programmable graph grammar (CP‐graph grammar) suitable for modeling the parallel direct solver algorithm utilized by the hp finite element method (hp‐FEM). In the proposed graph grammar model, the computational mesh is represented by a CP‐graph. The presented graph grammar models the solver algorithm by a set of graph grammar productions. The graph grammar model makes it possible to examine the concurrency of the algorithm by analyzing the interdependence between the atomic tasks, tasks and super‐tasks. The atomic tasks correspond to the graph grammar productions, representing basic undividable parts of the algorithms. The level of atomic tasks models the concurrency for the shared memory architectures. On the other hand, the tasks correspond to the groups of atomic tasks with predefined inter‐task communication channels. They constitute the grain for the decomposition of the parallel algorithm for the distributed memory architecture. Finally, the super‐tasks correspond to a group of tasks resulting from the execution of load balancing algorithm. The solver algorithm is tested on distributed memory linux cluster for up to 192 processors. Copyright © 2009 John Wiley & Sons, Ltd.
Is human growth hormone an ergogenic aid?
Authors: Holt Richard I. G.
Published: October 2009

Growth hormone (GH) was first isolated from the pituitary gland in the 1940s. It is believed that athletes have been abusing GH for its anabolic and lipolytic effects since the early 1980s, at least a decade before endocrinologists began to treat adults with GH deficiency. Most of our knowledge about GH abuse is anecdotal but a number of high‐profile athletes have admitted using GH. Despite its widespread abuse, there is debate about whether GH is ergogenic. Indeed most scientific studies have not shown a performance enhancing effect. This review will address why this discrepancy of opinion between athletes and scientists exists and why the author believes that the scientists are wrong. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and Characterization of Gold(I) Complexes with 9‐(4‐Isocyanophenyl)carbazole or 9‐Ethyl‐3‐isocyanocarbazole Ligands
Authors: Benavente Rut , Espinet Pablo , Lentijo Sergio , Martín‐Álvarez Jose M. , Miguel Jesús A. , Paz Rodríguez‐Medina M.
Published: October 2009

The carbazole derivatives 9‐(4‐isocyanophenyl)carbazole, 3,6‐dibromo‐9‐(4‐isocyanophenyl)carbazole, and 9‐ethyl‐3‐isocyanocarbazole were prepared and used to synthesize [AuX(CN‐carbazole)] (X = Cl, C6F5, C6F4‐OEt‐p) gold complexes. The X‐ray structures of [Au(C6F4‐OEt‐p){9‐(4‐isocyanophenyl)carbazole}] and [Au(C6F5)(9‐ethyl‐3‐isocyanocarbazole)], and the luminescent properties of the ligands and the complexes in the solid state, in solution at room temperature, and in frozen solution of chloroform at 77 K were determined. All the gold complexes show a redshift in the emissions relative to that of the free ligand. The presence of electron‐withdrawing substituents in 3,6‐dibromo‐9‐(4‐isocyanophenyl)carbazole quenches the luminescence, but with the introduction of a gold atom some luminescence is recovered.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)