bluuebunny/crossref_metadata_2025 huggingface dataset:
L'évolution de la géographie des océans et des littoraux face aux perspectives du développement durable au XXIe siècle. Quelles hypothèses envisager?//The geography of coasts and seas facing sustainable development: what could be the future?
Authors: Miossec Alain
Published: October 2008

Que sera l'avenir des océans et des zones côtières ? C'est à la lumière du passé qu'il faut comprendre les évolutions futures. L'actuelle phase de mondialisation des échanges, qui exprime le triomphe du libéralisme sous toutes ses formes a d'évidentes conséquences sur les littoraux où la pression s'accentue. Elle apporte avec elle une compétition plus forte pour l'espace et menace la qualité globale de l'environnement marin et côtier. On peut prévoir que ces phénomènes vont se poursuivre mais on sait également que la communauté internationale s'est inquiétée, depuis le sommet de la terre de Rio de Janeiro en 1992, des conséquences d'un essor mal maîtrisé. Le Chapitre 17 de l'Agenda 21 met en avant divers principes, à partir d'ailleurs de politiques plus ou moins efficaces élaborées par exemple en France et aux États-Unis : on n'entre pas dans le millénaire à l'aveugle et bien des incertitudes subsistent, qui mobiliseront les géographes du monde entier. Parmi elles, l'élévation contemporaine du niveau des mers menace les biens et les personnes trop exposés mais elle invite chacun à la sagesse et à une gestion précautionneuse de l'environnement maritime et côtier.
Une géographie des canalisations d'eau potable dans la Manche//A drinking water pipes geography in department of Manche (France)
Authors: Cador Jean-michel
Published: October 2008

Drinking water pipes are an important patrimony, accumulated from the beginning of the century, but largely unknown. An inventory in the Manche departement (Western Normandy) has been made and enables to reconstitute the pipe laying history and its geography. 12000 kilometers of pipes have been invento-ried, half of which are more than 25 years old, for a total value of 2 600 millions of francs : most of the kilometers were built during the mid 70% at a rate of 1 000 kilometers each year. After this period, the rate fell to only 100 kilometers per year. The analysis of the spatial layout of drinking water pipes enables to identify regions with an old water supply or with problematic materials, where part of the facilities will have to be replaced in the next ten years.
Pour une géographie humaine structurale//Eléments of structural geography
Authors: Desmarais Gaëtan
Published: October 2008

La géographie structurale ramène la diversité des phénomènes empiriques à l'unité d'un objet de connaissance morphologique et dynamique, enrichissant ainsi l'étude de quatre problèmes géographiques majeurs. Au fondement du rapport homme-nature, cette approche reconstitue la genèse d'un interdit spatial de propriété qui médiatise les transformations des environnements naturels en espaces culturellement investis. À propos de la différenciation régionale, la géographie structurale dégage la double dimension anthropologique et politique qui devance les valorisations économiques et les occupations concrètes. Ces éléments théoriques permettent alors de concevoir les localisations comme des positions structurales engendrées par les trajectoires qui y mènent. Un modèle d'espace anisotrope est enfin proposé pour rendre compte de l'organisation spatiale des établissements.
Grandes entreprises et crise, reconversion et fonds européens: le cas de la Principauté des Asturies (Espagne)//Big firms and crisis, industrial redeployement and European funds: case study of the Principality of Asturias (Spain)
Authors: Taulelle François
Published: October 2008

De nombreuses reconversions industrielles se sont produites en Europe, dans les secteurs d'industrie lourde, à la fin des années 1970 et au cours des années 1980. En France par exemple, la création des pôles de conversion date de 1984 et la politique en faveur des friches industrielles de 1986. Dans les Asturies, les secteurs de la sidérurgie et du charbon, qui assuraient le dynamisme de l'économie, connaissent une crise rapide et brutale au début des années 1990. Les emplois diminuent fortement mais la «mort est douce» puisque des mesures sociales exceptionnelles atténuent les effets de la crise. Néanmoins, la Principauté sort exsangue de cette mutation industrielle tardive. L'éligibilité du territoire aux fonds structurels européens, à partir de 1989, a pour principal effet de construire un système régional d'action publique jusque-là quasi inexistant : les grands groupes d'État géraient la Principauté. En dépit de moyens financiers importants et des multiples efforts faits pour encourager l'esprit d'entreprise, la Principauté se heurte à des blocages essentiels : la baisse du nombre d'habitants, le départ des jeunes et le manque crucial de projets. L'enclavement de la région freine aussi les échanges et l'attractivité. Après avoir tracé un tableau historique de la crise, l'article a pour ambition l'analyse du jeu des acteurs face à la reconversion de l'industrie lourde. À travers cette étude de cas, apparaissent aussi les implications sociales des liens entre firmes et territoires dans une phase critique de reconversion.
Réflexions sur une géographie nationale du tourisme: le cas de la Nouvelle-Zélande//Towards a national geography of tourism: the example of New Zealand
Authors: Pearce Douglas G.
Published: October 2008

Face à l'éclosion d'études géographiques du tourisme partout dans le monde, nous cherchons à développer une approche plus systématique pour l'étude des écoles nationales de géographie du tourisme et à l'illustrer à partir du cas de la Nouvelle-Zélande. Quatre facteurs fondamentaux sont identifiés — la géographie nationale, le tourisme national, des facteurs externes et les préférences personnelles des chercheurs. Leurs impacts sur la géographie du tourisme en Nouvelle Zélande sont examinés. Parmi les recherches néo-zélandaises on peut distinguer quelques thèmes particuliers : l'analyse des flux touristiques, le tourisme dans les parcs nationaux, la restructuration et l'étude de nouveaux types de tourisme.
Le poids des étrangers en Côte d'Ivoire / The importance of foreigners in Ivory Coast
Authors: Bouquet Christian
Published: October 2008

According to the Ivory Coast 1998 census — whose results are considered reliable —, an inhabitant out of four is a foreigner, that is more than 4 million people, among them 2,2 million Burkinabes and 800 000 Malians. Living mostly in rural areas, this foreign population were attracted by a high demand for labour going back to colonization. They are 70 % Muslims, bave poor schooling and form a young population, 99 % are active either in agriculture or in the informal sector; they are to be found particularly in the plantation economy where they control most of the branches. However, their status could become precarious if the 1998 landowner law is fully implemented, the land they have been farming risks being taken away from them. Today's increasing xenophobia in Ivory Coast might even chase them out of a country which intends to build its identity at their expense. This study analyses the political difficulties involve in such an intricate situation, within an unfavourable economic context.
Les Pyrénées centrales: de la redéfinition du rapport à l'espace aux enjeux actuels / Central Pyrénées : on the current issues regarding the redefinition of the vision of space
Authors: Despin Laurent
Published: October 2008

La recomposition territoriale observée aujourd'hui dans les Pyrénées centrales s'inscrit dans un temps long et elle plonge ses racines dans la mutation de société de la civilisation pastorale préexistante sur l'espace pyrénéen. La prise en compte des dynamiques socio-spatiales de cette région à partir du XIXe siècle permet d'en montrer les principales étapes — où se succèdent crises et mutations — et de souligner comment elle se transforme sur le terreau fertile de la redéfinition du rapport nature-société. À travers la description critique de ce processus, on peut mettre en avant des implications concernant les enjeux actuels qui soulèvent une problématique liée à la spécialisation d'un territoire, et qui posent la question de la relation au monde urbain.
La frontière Italie-Slovénie dans le contexte de l'élargissement de l'Union Européenne / The Italian-Slovenian Border in the Framework of the European Union's Enlargement
Authors: Sanguin André-Louis , Mrak Berta
Published: October 2008

L'actuelle limite internationale entre l'Italie et la Slovénie fut l'une des zones frontalières les plus ballotées et tiraillées de toute l'Europe. La question de Trieste constitua un dilemme frontalier difficile après la Seconde Guerre Mondiale. En 1947, l'établissement de la nouvelle frontière Italie-Yougoslavie eut pour effet de sectionner la ville de Gorizia. La zone frontalière est le lieu d'un original entrecroisement territorial de minorités nationales. L'actuelle frontière Italie-Slovénie est l'objet d'intenses flux et échanges. De nombreux travailleurs frontaliers résident côté slovène. L'entrée prochaine de la Slovénie dans l'Union Européenne favorise la coopération transfrontalière et l'émergence des Eurorégions. La « croix autoroutière slovène » ancre la Slovénie dans la logique territoriale de l'Union Européenne. L'article s'inscrit dans la portée d'une théorie générale de la coopération transfrontalière et des Eurorégions.
Les tempêtes, un concept et une genèse revisités : I'exemple de la façade occidentale de l'Europe / Storms, a notion revisitated : the case of Western Europe facade
Authors: Tonnerre Marie-Ange
Published: October 2008

Storms have been traditionally based on anemometric excesses. We argue you here a different point of view, one where isobaric developments are also taken into balance. As a result, a storm hecomes a single individual entity, that is an aggravated low pressure. That explains why the physionomical features are privileging the trajectories and their related barometric developments. In order to explain sudden aggravations, we show that the aggravation process depends on the warm air-mass entering into the talwegs. This phenomenon can take place during the Fall when strong warm advections swarmed into the the higher talwegs, which are being deformed on the midst of huge low geopotential zones. During the Winter, with the renewed situation of quick zonal circulations, sudden deformations in the upper-jet are putting into palce in Europe's Western coast clear spatialized geopotential drops. These moving talwegs still cause violent risings of warm air-mass. Least expected during Winter, this mechanism remains hazardous.
Les savanes d'Afrique centrale entre enclavement et intégration aux marchés / Central African savannas : between isolation and market integration
Authors: Géraud Magrin Y. , Jamin Jean-Yves , Faure G. , Duteurtre Guillaume
Published: October 2008

This study illustrates how an eco-regional approach that takes into account the local diversity contributes to a better understanding of the contemporary spatial dynamics in Africa. It was applied to the study of the Central Africa savannas, which spread across Northern Cameroon, Southern Chad and the Central African Republic, are fairly homogenous geographically. Located between the Sahel and the African forest regions, savannas are transitional environments, enclosed spaces, which are still very rural and have a relatively dense but diverse population. The development of the cotton production since the colonial times has heavily marked the agricultural Systems. These areas are now being affected by rapid changes. Demographic growth is encouraging the intensification of crop production, and the combination of crop and livestock production. At the same time, people are moving from densely populated areas to set up agricultural pioneer fronts in sparsely populated areas. The "cotton crises" and regional urbanization are stimulating agricultural diversification, which is best seen by the growth in commercial food crops and the introduction of livestock production into the markets. However, the future outlook for evolution is unsettled. The cotton sector has an uncertain future given the world market crash, and the pressure to privatize from Bretton Woods. The management reorganisation, which has seen non-State structures (NCOs, farmer organizations) taking the initiative to the detriment of the State, and the increasing decentraiization policies are as much a source of hope as a cause for concern. The next extraction of Chadian oil from Doba is likely to amplify the spatial changes that have begun. The same applies to the road construction underway. By stimulating urbanization, these projects will increase demand for crop and animal products and encourage agri-cultural and pastoral Systems to diversify and become better integrated into the market. Thus, they are likely to lead to a situation where land is increasingly graded, something that will benefit those whose geographic potential (natural conditions, accessibility) and social dynamics will adapt most to the changes in progress.
Les mutations de la morphologie socio-spatiale algéroise / The transformation of Algiers urban morphology
Authors: Semmoud Nora
Published: October 2008

Quelques années après l'indépendance, les déséquilibres sociaux de la période coloniale et leur manifestation spatiale imprègnent la réappropriation de la capitale par les Algériens. La réappropriation de la ville s'est faite selon un système de reconnaissance sociale qui prévaut jusqu'à ce jour et dont le type d'habitat localisé dans la structure urbaine a été le médiateur. La pertinence de la structure socio-spatiale de la ville à l'indépendance se trouve dans ce processus de substitution d'une ségrégation sociale à la ségrégation ethnique de l'époque coloniale. Processus pour lequel l'urbanistique de la technostructure algérienne et de ses prédécesseurs a joué un rôle moteur. Le contexte politique socialisant des années 70 et les nouvelles exigences socio-économiques ont permis l'émergence de politiques urbaines, notamment foncières qui ont induit des stratégies de résistance de la part des propriétaires fonciers. Le développement des transactions foncières illicites libérait du même coup les pratiques d'autres groupes sociaux dans leur appropriation de l'espace. Ce marché immobilier parallèle a permis aux uns d'inscrire dans l'espace le mode d'habiter qui signifiait leur ascension sociale et aux autres, touchés dramatiquement par la crise du logement, de réaliser eux-mêmes leur habitat. Le changement de régime des années 80 s'est accompagné d'une nouvelle politique urbaine qui va remettre en cause les options antérieures en libéralisant le marché foncier existant, en encourageant l'habitat pavillonnaire, en libéralisant la promotion immobilière privée et en légalisant les constructions illicites. La façon dont ces mesures ont été menées leur confère un caractère ségrégatif davantage souligné par le désengagement de l'État de la construction de logements sociaux, par la braderie du patrimoine foncier et immobilier et par la déportation de la population des bidonvilles d'Alger vers son lieu d'origine. Cette politique a contribué à creuser les écarts entre les différentes couches sociales allant jusqu'à remettre en cause le droit à la ville des plus défavorisés. Ces politiques urbaines successives ont progressivement configuré l'espace algérois qui se présente aujourd'hui comme un territoire fragmenté socialement et spatialement.
Les lacs de Tunis en projets, reflets d'un nouveau gouvernement urbain / Developing the lakes of Tunis : a new approach in urban governance
Authors: Barthel Pierre-Arnaud
Published: October 2008

Longtemps considérés comme des repoussoirs et des exutoires, les lacs de Tunis, composantes majeures du site de la capitale, sont aujourd'hui devenus des priorités de l'aménagement. Objets d'une nouvelle attractivité, ils sont les sites de projets de très grande ampleur qui en sont à des stades d'élaboration et de concrétisation très divers. Cet article montre que ces quatre projets sont les révélateurs de nouvelles relations de pouvoir basées sur le partenariat entre acteurs publics et investisseurs étrangers. L'émergence de nouvelles formes de maîtrise d'ouvrage urbaine qui intègrent les logiques du marché, le désengagement de l'État et les transferts de pouvoir qui en découlent sont les principales réformes en cours. Au regard des réalisations, l'évolution des modes d'action sur la ville s'avère féconde. Toutefois, la gestion de Tunis est encore guidée par des pratiques qui relèvent d'une tradition étatique technocratique et autoritaire. Bien que l'État oriente la fabrication urbaine vers un partage contrôlé du pouvoir, la gouvernance démocratique n'est pas à l'ordre du jour. Il reste à savoir si les récentes réformes conduiront à développer le processus démocratique en impliquant réellement les pouvoirs locaux et la société civile.
Les conflits environnementaux à St Lucia (Afrique du Sud), entre protection et exclusion / Environmental conflicts in St Lucia (South Africa) between conservation and exclusion
Authors: Guyot Sylvain
Published: October 2008

The St Lucia case study is a contribution to the re-reading of the territorial strategies of the colonial, apartheid and post-apartheid South Africa, at local and national levels. It shows ambivalence between the will of Afrikaners to segregate themselves, the proclamation of national parks, and the reality of a majority of poor black people trying to exist politically. In light of the new constraining environmental laws, we see the development of environmental conflicts where Afrikaners are battling to preserve their free access to the sea while poor Blacks are illegally occupying a State forest.
La mondialisation comme instrument politique local dans les métropoles sud-africaines (Johannesburg et Ekhuruleni): les « pauvres » face aux « vitrines » / Globalisation and local urban policies in South African metropolitan areas (Johannesburg and Ekhuruleni): shop-window and back-shop
Authors: Benit Claire , Gervais-Lambony Philippe
Published: October 2008

Based on the case studies of two South African metropolitan areas (Johannesburg and Ekhuruleni in the Gauteng Province), this paper reflects on the relation between globalisation and local urban policies. We argue that in South Africa's metropolisation process (finalised in 2000) globalisation has been used in the political and urban planners discourse to justify a neo-liberal urban policy, for one, and to reinforce the role of the central state, for the other. This strategy is partly hidden by a general insistence on local democracy, " good governance " and participation. It thus allows the state to concentrate on public and private investments in some part of the cities (the shop window), and to manage poverty in some others (the back shop). The demonstration is based on an analysis of the general urban policy, as well as of local examples of problematic public participation in deprived areas. This does not imply that there is no hope and progress in South African large urban settlements, but that the risk of developing new socio-spatial gaps is high.
Les stratégies parentales dans I'espace de I'école: secteurs, zones et paysages scolaires a Créteil//Parental strategies in the school environment: district wards and school landscapes in Créteil (France)
Authors: Durand Bénédicte
Published: October 2008

Le district de Créteil (commune du Val-de-Marne, France) offre un exemple de fonctionnement de I'espace scolaire dans les péripheries des grandes agglomérations. L'espace scolaire y est caractérisé par deux situations paradoxales. La première oppose un réseau puissant d'établissements plus ou moins attractifs ou répulsifs à la politique educative nationale qui fait prevaloir la régie de la proximité entre le lieu d'habitation et le lieu de scolarisation. Ce réseau est animé par d'actives stratégies parentales particulièrement sensibles à Créteil (dérogations, déménagement, recours à l'école privée) qui remettent en cause la régie de la carte scolaire. La seconde met en jeu une école dont le destin est, par le fait même des lois de la sectorisation, profondement lié à celui de son environnement, face à la volonte accrue de ses administrateurs de l'isoler par une intervention sur le paysage scolaire (clöture, prise en compte de l'esthétique des bâtiments) dans les quartiers les plus défavorisés de la ville.
À quoi servira la politique régionale européenne en Pologne?//What is the use of the EU regional policy in Poland?
Authors: Lepesant Gilles
Published: October 2008

Principale politique commune européenne après la PAC, la politique régionale est désormais confrontée à l'élargissement à dix pays auxquels elle versera environ 22 milliards € sur la période 2004-2006. Parallèlement, un débat sur son coût, son efficacité, ses priorités est soulevé par la préparation de la période de programmation 2007-2013. Au moment où la Pologne, principale économie en transition d'Europe centrale, achève les préparatifs nécessaires à la mise en œuvre de cette politique sur son territoire, cet article expose les principales transformations territoriales survenues au cours de la dernière décennie et présente les enjeux et les choix qui ont dominé ces préparatifs. Selon sa thèse principale, l'impact des fonds structurels sera dans un premier temps moins sensible sur la géographie économique du pays que sur la modernisation des réseaux et des pratiques institutionnels. Loin d'être négligeable, cette contribution devrait créer les conditions d'un développement endogène plus dynamique des territoires polonais et, incidemment, enrichir le débat sur l'utilité de la politique régionale européenne.
De la difficulté à cerner les territoires du religieux: le cas de I'islam en France//A territorial approach to religions in French cities: the example of Islam
Authors: Vieillard-Baron Hervé
Published: October 2008

Studying the implantation of religions in France poses a problem of methodology, since censuses on cult membership ceased in France in 1872. Furthermore, the location of the places of worship does not always correspond to the place where the community is settled. With regard to French Muslims, close scrutiny clearly shows that they do not settle within the urban areas in a purely haphazard way. The political, economic and social conditions of immigration explain to a large extent how the immigrants spread out, not only on the social housing estates around the big cities, but also in the old districts in the town centres, where they have very often been welcomes in the first place. In there, religion appears to provide the youngsters, who would otherwise be without a structured code of behaviour, with a sense of purpose or justification that mainstream political and social institutions no longer offer. Should this be interpreted as a failure by the Republic to integrate the second or third generation of Muslim immigrants, or simply as a stage in the development of these youngsters' personal identity? These questions, along with the problem posed by the utilization of private and public spaces and with the issues raised by the elected Council of Muslims of France, are here discussed in reference to few select examples taken mainly from the outskirts of Paris and Lyons.
Patrimonialisation et réaffirmation symbolique du centre-ville du Havre. Rapports entre le jeu des acteurs et la production de I'espace//Heritage-making and symbolic re-affirmation of Le Havre's downtown. A study of the relations between local authorities' actions and the production of an urban space
Authors: Gravari-Barbas Maria
Published: October 2008

Le réinvestissement politique, fonctionnel et symbolique du centre-ville du Havre, effectue au cours des dernières années par l'intermédiaire de la patrimonialisation de l'architecture de la reconstruction apparaît comme le produit d'actions volontaristes, délibérement menées par les autorités locales ou nationales. A travers l'analyse du jeu des acteurs locaux - des consensus, des conflits, des luttes de pouvoir qui s'observent sur la scène politique- nous opererons une lecture de la réemergence du centre reconstruit en tant qu'espace-action (en tant donc qu'espace concentrant de nouveau des initiatives architecturales, urbaines, evenementielles ou festives). La patrimonialisation (approchée ici comme une construction volontariste de patrimoines spatialisés) du centre-ville reconstruit s'avère in fine intrinsèquement liée à des processus d'appropriation de l'espace.
Politique agricole et agriculture aux Etats-Unis: evolution et enjeux actuels//Agriculture and Agricultural Policy in the United States: evolution and issues
Authors: Devienne Sophie , Bazin Gilles , Charvet Jean-Paul
Published: October 2008

Within the global context of liberalization of agricultural trade, the United States and the European Union provides the highest support to their agricultural sectors. The two entities are the world's largest exporters, accounting respectively for 19 % and 18 % of the World agricultural trade. It is the result of long-lasting traditions of strong agricultural policies. This paper examines the goals, the approaches and the results of the United States farm policy, while providing some elements of compa- rison with the European Union. First introduced in 1933, agricultural policies in the United States have been based on a combination of supply controls and farm price support; in 1996, the legislation changed and the new system now gives direct income support payments without any supply control. These supports spurred on the increase of production and labor productivity in the agricultural sector, which allows the US farms to be amongst the most productive in the World. Despite this, US export market share have tended to decline since the 1980% largely due to the steady increasing competition from the European Union and the CAIRN countries (mainly Brazil, Argentina and Australia). A change that has raised new issues and concerns. Among them are the need to increase the share of high value products in the US agricultural exports — the European Union appears to be ahead in this area —; the capitalization of subsidies into land value accruing mainly to landowners; the negative impact of wealthier countries' high agricultural support and subsidies on the agriculture of developing countries, which has lead to the failure of the last WTO's meeting.
La geographie des centres d'appels en France//The French geography of the call-center industry
Authors: Moriset Bruno , Bonnet Nicolas
Published: October 2008

Les centres d'appels constituent une des activités émergentes de la nouvelle économie. Ils proposent au geographe une problématique intéressante: quels sont les facteurs de localisation d'établissements qui délivrent au client un service à distance. La carte des implantations dans les aires urbaines franchises, comptabilisées par postes de travail, montre une répartition spatiale irrégulière, mais qui reste fortement metropolisés. Une analyse plus fine met en evidence un processus de diffusion hiérarchique, à partir de la Capitale, puis vers les métropoles régionales, et enfin vers I'espace à dominante rurale. Ce processus crée des opportunités de créations d'emploi. Les centres d'appels sont devenus la cible des politiques locales de développement économique, et un outil de reconversion des bassins d'emploi en difficulté. Mais la croissance des délocalisations outre-mer fait peser une menace sur ces activités nouvelles. La croissance des centres d'appels est un des phénomènes par lesquels les territoires entrent dans l'ère du «capitalisme cognitif», dans un contexte de globalisation et de métropolisation. Mais les effets dynamisants de cette activité fortement taylorienne sont incertains, et elle ne saurait en aucun cas devenir une mono-activité.
Sangatte: vie et mort d'un centre de «réfugiés»//Sangatte: life and death of a "refugees" centre
Authors: Liagre Romain , Dumont Frédéric
Published: October 2008

Durant plus de trois années d'existence, quelque 65 000 etrangers en situation irreguliere, originaires d'une centaine de pays, ont transite par le Centre d'Hebergement et d'Accueil d'Urgence Humanitaire de Sangatte (Pas-de-Calais), dans I'espoir de traverser la Manche pour rejoindre la Grande-Bretagne. Au fil des mois, les flux continuant a s'amplifier, le Centre devint un sujet mediatique et politique, un point de disaccord entre la France et la Grande-Bretagne, et surtout un symbole des dysfonctionnements des politiques europeennes en matiere d'asile. Au-dela de toute polémique, et plusieurs mois apres la fermeture et la destruction du Centre, cet article tente de dresser un bilan de ces trois annees d'existence. D'une part en analysant demographiquement les populations passées par le Centre (na-tionalites, sexe...) et en etudiant les principaux itineraires empruntes. Et d'autre part, en essayant de mettre en lumière les changements induits par la disparition du Centre.
Exendin-4 Treatment Expands Graft β-Cell Mass in Diabetic Mice Transplanted with a Marginal Number of Fresh Islets
Authors: Juang Jyuhn-Huarng , Kuo Chien-Hung , Wu Chun-Hsing , Juang Charity
Published: October 2008

Exendin-4 stimulates insulin secretion, suppresses glucagons secretion, increases β-cell replication and neogenesis, and reduces β-cell apoptosis. However, it has been shown that posttransplant exendin-4 treatment did not improve glucose homeostasis in diabetic mice transplanted with a large number of freshly isolated islets. The aim of this study was to test if exendin-4 is beneficial for hyperglycemic recipients with a marginal number of fresh islets. We transplanted 150 C57BL/6 mouse islets under the kidney capsule of inbred streptozotocin-diabetic mice, and then treated the recipients with and without exendin-4 for 6 weeks. Before and after transplantation, recipients' blood glucose, body weight, and intraperitoneal glucose tolerance test were measured. At 6 weeks, the grafts were removed to determine β-cell mass. Blood glucose levels in both groups decreased progressively after transplantation, and the exendin-4-treated group had had lower blood glucose than controls since day 3. By 6 weeks, euglycemia was achieved more in mice treated with exendin-4 than in controls (100% vs. 62.5%, p = 0.018). The time to obtain normoglycemia was shorter in the exendin-4-treated group than in controls (12± 8 vs. 29 ± 13 days, p < 0.001). Blood glucose at 6 weeks was 123 ± 18 and 170 ± 62 mg/dl in the exendin-4-treated group and controls, respectively (p = 0.008). Additionally, the exendin-4-treated group had better glucose tolerance than controls at 2 and 4 weeks (p < 0.02). However, both groups exhibited increased body weight over time, and weight changes did not significantly differ between the two groups throughout the study period. At 6 weeks after transplantation, grafts in the exendin-4-treated group were more prominent and contained more insulin-stained cells than those of controls. They had 2.3-fold β-cell mass of the graft compared with controls (0.30 ± 0.11 vs. 0.13 ± 0.03 mg, p = 0.012). These results indicate posttransplant exendin-4 treatment in the diabetic recipient with a marginal number of fresh islets expands graft β-cell mass and improves transplantation outcome.
In Vivo Survival and Osteogenic Differentiation of Allogeneic Rat Bone Marrow Mesenchymal Stem Cells (MSCs)
Authors: Kotobuki Noriko , Katsube Yoshihiro , Katou Youichi , Tadokoro Mika , Hirose Motohiro , Ohgushi Hajime
Published: October 2008

Marrow mesenchymal stem cells (MSCs) are multipotent progenitor cells and reported to be immunoprivileged as well as immunosuppressive. Hence, MSCs might be ideal candidates for allogeneic transplantation to induce regeneration of damaged tissues/organs. To confirm the differentiation capability of allogeneic MSCs in vivo is important for the acceleration of regenerative medicine. Consequently, we have established an in vivo rat model using subcutaneous implantation of a hydroxyapatite (HA) ceramic/MSCs composite. Osteogenic differentiation was used as an indicator of differentiation. When syngeneic MSCs were implanted, MSCs showed osteogenic differentiation as evidenced by new bone formation as well as high alkaline phosphatase (ALP) activity. When allogeneic MSCs were implanted, none of the allografts survived or showed osteogenic differentiation. However, when the recipient rats were treated with FK506 immunosuppressant, allogeneic MSCs showed osteogenic differentiation. Although this finding might not be adequate for the acceleration of regenerative medicine, these results did confirm that MSCs are not intrinsically immunoprivileged but that under appropriate immunosuppressant treatment, allogeneic MSCs can survive and show differentiation capability in vivo.
A Critical Review of Ecotourism Studies in Thailand
Authors: Sangpikul Aswin
Published: October 2008

Ecotourism has emerged as a key foundation of sustainable tourism development. During the past decade, the study of ecotourism in Thailand has increased considerably. Yet, proper guidelines and research directions for ecotourism research in Thailand are still limited. The purpose of
this study is to survey and overview ecotourism studies in Thailand during the past decade (1995–2005). The study examines 334 ecotourism-related studies and provides suggestions for ecotourism research direction in Thailand, particularly in the area of limited knowledge or unexplored
research areas.
Formación de corrensita en turbiditas calcáreas con silex del Campo de Gibraltar (SW de España)
Authors: Rodríguez Jiménez P. , Ruiz Cruz M. D. , Carrasco F.
Published: October 2008

Este trabajo tiene como objetivo fundamental el poner de manifiesto las relaciones que existen entre el proceso de silicificación de las calizas turbidíticas y el desarrollo de corrensita. La mineralogía determinada viene condicionada por dos factores: tipo de aportes y ambiente diagenético. El tipo de aportes es similar, en gran medida al de las turbiditas calcáreas que constituyen la base de estas Unidades, donde la ilita y los interestratificados I-E (o esmectitas) son los constituyentes fundamentales. El ambiente diagnético es el responsable del desarrollo de corrensita y posibles zeolitas, así como de la silicificaci6n de las calcarenitas. La paragénesis y las características químicas determinadas permiten señalar para el ambiente de formación de estos minerales una elevada actividad de sílice, y un contenido importante en hierro y magnesio, si bien no ha de estar en relación necesariamente con medios evaporíticos. La liberación de Fe y Mg de las calizas silicificadas ha podido influir decisivamente en el desarrollo de los minerales citados así como en el crecimiento de gran número de óxidos de hierro. La silicificación ha tenido lugar durante una diagénesis temprana, mediante un proceso inorgánico, dada la ausencia de organismos silíceos y de manifestaciones volcánicas en relación con estos materiales.
Análisis estructural y metamórfico de la deformación hercinica del borde meridional de la Sierra de la Demanda
Authors: Yenes M. , Alvarez F. , Nieto F.
Published: October 2008

La sucesión estratigráfica paleozoica que aflora en el borde meridional de la Sierra de la Demanda, cuya edad abarca desde el Cámbrico al Ordovícico, ha sido dividida en seis formaciones diferentes que son equivalentes por facies, a las que afloran en el sector más occidental de la Zona Asturoccidental-Leonesa. Estos materiales han sido afectados por dos fases de deformación hercínicas y una fracturación tardihercínica. La primera fase hercínica origina pliegues de todos los órdenes que llevan asociada una esquistosidad primaria; la segunda fase da lugar a cabalgamientos y, ocasionalmente, a una esquistosidad de crenulación. La deformación va acompañada de un metamorfismo regional de grado bajo y muy bajo cuya intensidad, en términos generales, decrece hacia el SE. Los datos cristaloquímicos obtenidos del estudio de las muestras pizarrosas mediante difractogrametría de Rayos X, han permitido localizar el límite epizona-anquizona y, en algún caso, poner de manifiesto el salto metamórfico producido por las fallas.
A comparative study of the feeding ecology of Nephrops norvegicus L. (Decapoda: Nephropidae) in the bathyal Mediterranean and the adjacent Atlantic
Authors: Cristo Margarida , Cartes Joan E.
Published: October 2008

A comparative study of the feeding ecology of Nephrops norvegicus was carried out on a seasonal basis simultaneously in seven locations in the Eastern and Western Mediterranean and the adjacent Atlantic: the south coast of Portugal, Faro; the Alboran Sea, Malaga; the Catalan Sea, Barcelona; the Ligurian Sea, Genoa; theTyrrhenian Sea, Pisa; the Adriatic Sea, Ancona and the Aegean Sea, Gulf of Euboikos. The major groups observed (frequency of occurrence method) in the stomachs of Nephrops norvegicus were decapod crustaceans, other crustaceans (euphausids and peracarids) and fish. The results obtained showed no significant differences between sites or seasons, and can be considered very consistent. All major taxa were present in the diet at all sites and for all seasons, a fact that can be explained by the great similarity of the bathyal fauna in all sites, which provide a major trophic resource for N. norvegicus. The percentage of fullness was also estimated per site and season, and we registered a clear decrease of this value during the summer period for all sites, except the Tyrrheanian Sea, where the lowest value was found in autumn. PCA - analysis did not clearly separate the regions (sites). The Shannon-Weaver (H´), index of diversity, was also determined per site and season, and we found a significant difference between the values of the Atlantic coast and the Western Mediterranean when compared with those of the Eastern Mediterranean.
Reproductive biology of Perkinsiana antarctica (Kinberg) (Polychaeta, Sabellidae) in the Straits of Magellan (South America): Systematic and ecological implications
Authors: Gambi María Cristina , Patti Francesco Paolo
Published: October 2008

Reproductive biology and larval development of the polychaete Perkinsiana Antarctica (Kinberg, 1867) (Sabellidae) are described of a population sampled in October 1994 and March 1997 in the type locality of this species, the Straits of Magellan (Southern Chile). Perkinsiana antarctica is a simultaneous hermaphrodite. Eggs are present in the thorax and in the anterior part of the abdomen, while sperm cells occur in the posterior abdomen. Spermatids are grouped in tetrads; mature sperm cells present an oval nucleus (length of major axis about 3 µm) and the acrosome is about 2.5 µm long with a conoid shape. Mature eggs have a mean diameter of 235 µm; embryos and larvae are incubated within the branchial crown of specimens exceeding 10 mm in length. Hatching larvae have a mean length of 420 µm, with 4 segments, each bearing two notochaeta; two ocular spots and a well-developed prototroch are present at the anterior end. Both number of embryos and larvae per individual showed a relatively high range of variation (embryos from 54 to 374, mean=173; larvae from 18 to 222, mean=101). The features of reproductive biology in P. antarctica do not seem to be related to the size of the species itself, as P. antarctica represents one of the largest-sized sabellids that are brooding eggs, and producing a relatively high number of offspring. These reproductive and developmental traits seem more related to the colonization of harsh and selective habitats, such as the intertidal and shallow subtidal of the Subantarctic areas. Comparisons with the reproductive biology of other species of Perkinsiana demonstrate a high degree of variability within the genus regarding reproduction and the apparent lack of synapomorphies.
Taxonomic study of the isopod crustaceans from the Spanish expedition Antártida 1986-11 in the Scotia Sea, South Atlantic
Authors: Castelló J.
Published: October 2008

This paper summarizes the results of a taxonomic study of the isopods collected during the Antártida 1986-11 expedition. A total of 123 specimens were studied, of which 99 were in the adult or juvenile phases and 24 were in the postmanca phase. The specimens were attributed to 11 species, 9 genera, 5 families and 4 suborders. The most abundant species were Glyptonotus antarcticus and Ceratoserolis trilobitoides. Several records are reported for the first time from the archipelagos of the Scotia Arc.
Chlorophyll and zooplankton in microbasins along the Strait of Magellan - Beagle Channel passage
Authors: Hamamé Madeleine , Antezana Tarcisio
Published: October 2008

Distributions of chlorophyll and zooplankton were compared to temperature and salinity distributions along previously defined microbasins. Results were consistent for chlorophyll: 1.- Paso Ancho-Seno Magdalena showed a shallow chlorophyll maximum (ca. 5 mg m-3 at 0 - 20 m) in a vertically homogeneous cold and brackish water column, 2.- Canal Magdalena-Canal Cockburn-Canal Brecknock had relatively lower chlorophyll concentrations (2-3 mg m-3 at 0-50 m), minor stratification of salinity and a surface lens of warmer water, 3.- Canal Ballenero-Brazo Noroeste had a subsurface layer of high chlorophyll concentration (> 4 mg m-3) in a vertically stratified water column of 2 salinity layers and 3 temperature layers, 4.- Canal Beagle presented a subsurface chlorophyll maximum (> 4 mg m-3) extending to the bottom, and vertically homogeneous salinity and temperature distribution. Chaetoceros spp.-dominated phytoplankton was a common feature in the entire area. Zooplankton distributions did not match the above mentioned subdivision of microbasins despite some trends along the passage. High relative abundance of invertebrate larvae in the zooplankton was associated with a matching response to the spring bloom and implies a strong bentho-pelagic coupling.
Preliminary data on chronic effects of ultraviolet radiation on the growth of some phytoplankton species of the Beagle Channel, Argentina
Authors: Hernando Marcelo P. , San Román Nemesio A.
Published: October 2008

Serious concerns exist that the thinning of stratospheric ozone and the resulting enhancement in the solar UVB radiation, may impair marine primary productivity. Also, UVB may alter food web dynamics and food availability for higher trophic levels in marine ecosystems inducing changes in phytoplankton species composition. The main goal of this study was to examine the responses of different species of marine phytoplankton to solar UVR. Specifically, we compared the UV sensitivity of a phytoplankton natural community isolated from the Beagle Channel (54°52´S, 68°18´W, Ushuaia, Argentina), as well as the response of two taxa which were isolated from that community (i.e., a pennate diatom, Navicula sp., and a phytoflagellate pertaining to the Class Cryptophyceae) to UV radiation. Exposure to UVB or UVA radiation treatments had no significant effects (p > 0.05) on exponential growth rate in Navicula sp. However, when the phytoflagellate [Class Cryptophyceae] was exposed to UVB, the growth rate in the exponential phase was inhibited significantly (p < 0.01) compared with the PAR control. Marked changes in the relative abundance of the main taxonomic groups were observed in the community cultures: the relative abundance of phytoflagellates was significantly lower after exposure to the UVB treatment than after exposure to the PAR treatment (p < 0.05). However, the percentage of centric diatoms increased significantly (p < 0.05) when they were exposed to UVB. The growth rate at the end of the exponential phase of growth of the community was inhibited significantly (p < 0.01) when the algae were exposed to UVB and UVA.
Trends in hydroidomedusan research from 1911 to 1997
Authors: Gravili C. , Pagliara R. , Vervoort W. , Bouillon J. , Boero F.
Published: October 2008

The papers on hydroidomedusae published from 1911 to 1997 total 10,934. They have been assigned to the following categories: faunistics and systematics; sub-organismal biology; ecology; evolution; life cycles; paleontology. The general trend, comprising all papers, can be divided into four time intervals: the first (1911-1939) with an average of sixty papers/year and with a slight decrease due to First World War; the second one (1940-1947), with an average of 38 papers/year, marked by a dramatic decrease coinciding with Second World War; the period 1948-1991 shows a steady increase until the mid-Seventies, when a small decrease occurred, followed by an increasing trend reaching its apex in the late Eighties-early Ninenties with a record of 296 papers in 1991 and with an average of 175 papers/year; the period 1992-1997, with an average of 178 papers/year, is marked by a sharp decrease, reaching the values of the mid Sixties. The most important category in terms of number of papers is sub-organismal biology, followed by faunistics and systematics. Systematic studies dictated the trend in the first decades of the century, whereas sub-organismal ones are prevalent from the Sixties onwards. Faunistic and systematic-taxonomic papers have a steady trend of production, with just a slight decrease over these last years. The formerly leading countries in systematics (UK, USA, France) are now almost inactive in this discipline, whereas countries with little or no tradition in this field (such as Spain) are taking the leadership.
Determination of metallic complexing capacities of the dissolved organic material in seawater
Authors: Laglera-Baquer Luis M. , González-Dávila Melchor , Santana-Casiano J. Magdalena
Published: October 2008

The use of the Langmuir isotherm for the study of the complexing properties of functional groups present both in dissolved organic material and on biological surfaces in aquatic systems needs a heterogeneous model and an iterative linear regression solution. The method proposed previously by van den Berg is improved by replacing the expression used to obtain the complexing capacity and the conditional stability constant of the functional groups with stronger trace metal affinity, for the linear expression of the Langmuir isotherm proposed by Scatchard. The result is also an iterative linear regression process, which gives a convergent solution, together with better statistical weight distribution of the initial metallic titration data. It also fits better with the titration data obtained at very low dissolved metallic ion concentrations.
Advection of continental water as an export mechanism for anchovy, Engraulis encrasicolus, larvae
Authors: Sabatés Ana , Salat Jordi , Olivar M. Pilar
Published: October 2008

The presence of a surface layer of a less saline water of continental influence (CIW) along the continental slope off the Catalan coast (NW Mediterranean) was observed in June 1995. This CIW was formed in the Gulf of Lions from Rhône runoff and carried by the current associated with the shelf-slope front. This study analyses the spatio-temporal behaviour of that water of continental influence in relation to the shelf-slope front, and its effect on the distribution of fish larvae, in particular the larvae of the anchovy, Engraulis encrasicolus. Displacements of the front are observed to follow an oscillation with a period of eight days and an amplitude of 10 km. Anchovy larvae were associated with the presence of CIW, whereas the oceanic species Hygophum benoiti appeared in the region of the slope when the front, and the associated CIW layer, moved close inshore during its oscillation. The size frequency distribution for the anchovy larvae trapped within the CIW suggests that the larvae had been spawned further north, near the Gulf of Lions. It is concluded not only that larvae were transported by the current but also that their development had taken place entirely inside the CIW. The possible benefit to the survival of anchovy larvae of being kept inside that water, though they have been carried far from their spawning areas, is discussed in the basis of fluorescence and microzooplankton data.