La Zone euro, noyau fédérateur de l'Europe

L’Union Européenne manque clairement d’Union politique. Seule une Union politique pourrait promouvoir une vision globale à l’intérieur de l’UE, qui contrasterait avec l’approche actuelle, trop étroite et trop centrée sur l’économie et la finance. Le fonctionnement de la Zone euro, qui devrait représenter le noyau dur de l’Union, reste paradoxalement intergouvernemental. Il est donc important d’aligner la Zone euro sur ce qui constitue le régime général du traité de Lisbonne : la méthode communautaire. Les institutions de la Zone euro devraient plus s’inspirer des institutions ordinaires de l’Union, avec une Commission et un Parlement jouant leur rôle. Cette évolution peut être conduite par la voie des « coopérations renforcées » dans la perspective d’une Union fédérale. L’article contient une série de propositions visant à jeter les bases d’un noyau fédéral européen au sein de la Zone euro

La crise existentielle de l'Union Européenne

L’Union européenne vit une crise existentielle. Deux remarques s’imposent face à la désintégration des communautés politiques multinationales : l’imprévisibilité et la rapidité du processus de désintégration par comparaison avec la lenteur de leur formation. Malgré les différences marquées il s’agit d’une leçon d’histoire immédiate à retenir pour l’Union européenne. Nous sommes devant le premier cas où les effets de la « crise macro » touchent directement les populations, la majorité des citoyennes et des citoyens, qui en souffrent dans leurs corps et leurs esprits. De surcroît, l’Union et ses peuples ont été exposés à un faisceau de menaces et de défis, tant intérieurs qu’extérieurs. Qu’il s’agisse de la Zone euro, des flux migratoires, de la paupérisation au lieu de la prospérité, du terrorisme, de la sécurité ou de la défense, ces domaines en interaction exigent tous, à des niveaux différents, le recours à des pouvoirs souverains

Redes transeuropeas como factor de federalización de la UE

PANEL I. LAS RTE. Y EL MODELO FEDERAL DE LA UNIÓ

Revolutionaries or Bargainers?: Negotiators for a New International Economic Order

This interview-based study analyzes the attitudes and negotiating behavior of 80 individuals, principally from less developed countries (LDCs), who were participants in international economic negotiations in 1976. Some of the more important findings are: (1) negotiators' views are more diverse than analyses of roll-call votes would indicate; (2) the positions that countries take appear to be firmly grounded in national political processes and in pragmatic conceptions of their national interests; (3) negotiators from LDCs with higher per capita GNP are more likely than those from LDCs with lower per capita GNP to perceive the negotiations as being polarized, to regard social issues as important elements of development strategies, and to take advantage of regional cooperation in negotiating; they are less likely to have negative views toward transnational corporation

Plasmodium sporozoites trickle out of the injection site

Plasmodium sporozoites make a remarkable journey from the skin, where they are deposited by an infected Anopheline mosquito, to the liver, where they invade hepatocytes and develop into exoerythrocytic stages. Although much work has been done to elucidate the molecular mechanisms by which sporozoites invade hepatocytes, little is known about the interactions between host and parasite before the sporozoite enters the blood circulation. It has always been assumed that sporozoites rapidly exit the injection site, making their interactions with the host at this site, brief and difficult to study. Using quantitative PCR, we determined the kinetics with which sporozoites leave the injection site and arrive in the liver and found that the majority of infective sporozoites remain in the skin for hours. We then performed sub-inoculation experiments which confirmed these findings and showed that the pattern of sporozoite exit from the injection site resembles a slow trickle. Last, we found that drainage of approximately 20% of the sporozoite inoculum to the lymphatics is associated with a significant enlargement of the draining lymph node, a response not observed after intravenous inoculation. These findings indicate that there is ample time for host and parasite to interact at the inoculation site and are of relevance to the pre-erythrocytic stage malaria vaccine effort

Migration of Apicomplexa Across Biological Barriers: The Toxoplasma and Plasmodium Rides

The invasive stages of Apicomplexa parasites, called zoites, have been largely studied in in vitro systems, with a special emphasis on their unique gliding and host cell invasive capacities. In contrast, the means by which these parasites reach their destination in their hosts are still poorly understood. We summarize here our current understanding of the cellular basis of in vivo parasitism by two well-studied Apicomplexa zoites, the Toxoplasma tachyzoite and the Plasmodium sporozoite. Despite being close relatives, these two zoites use different strategies to reach their goal and establish infection

The malaria circumsporozoite protein has two functional domains, each with distinct roles as sporozoites journey from mosquito to mammalian host

Conformational changes influence functional properties of circumsporozoite protein expressed on the surface of Plasmodium sporozoites

An acid-stable laccase from sclerotium rolfsii with potential for wool dye decolourization

The plant pathogen basidiomycete S. rolfsii secretes two laccases (SRL1 and SRL2) with molecular weights of 55 and 86 kDa, respectively. Laccase production was shown to be inducible by the addition of 2,5-xylidine to the cultural media. After treatment with a combination of chitinase and -1,3-glucanase, two different laccases were isolated from the sclerotia depending on the stage of sclerotia development. The more prominent laccase, SRL1, was purified and found to decolourize the industrially important wool azo dye Diamond Black PV 200 without the addition of redox mediators. The enzyme (pI 5.2) was active in the acidic pH range, showing an optimal activity at pH 2.4, with ABTS as substrate. The optimum temperature for activity was determined to be 62 ◦C. Enzyme stability studies revealed that SRL1 was notably stable at 18 ◦C and pH 4.5, retaining almost full activity after a week. Oxidation of tyrosine was not detectable under the reaction conditions but the enzyme did oxidize a variety of the usual laccase substrates. SRL1 was strongly inhibited by sodium azide and fluoride. Dye solutions decolourized with the immobilized laccase were successfully used for redyeing.(undefined

The Transmembrane Isoform of Plasmodium falciparum MAEBL Is Essential for the Invasion of Anopheles Salivary Glands

Malaria transmission depends on infective stages in the mosquito salivary glands. Plasmodium sporozoites that mature in midgut oocysts must traverse the hemocoel and invade the mosquito salivary glands in a process thought to be mediated by parasite ligands. MAEBL, a homologue of the transmembrane EBP ligands essential in merozoite invasion, is expressed abundantly in midgut sporozoites. Alternative splicing generates different MAEBL isoforms and so it is unclear what form is functionally essential. To identify the MAEBL isoform required for P. falciparum (NF54) sporozoite invasion of salivary glands, we created knockout and allelic replacements each carrying CDS of a single MAEBL isoform. Only the transmembrane form of MAEBL is essential and is the first P. falciparum ligand validated as essential for invasion of Anopheles salivary glands. MAEBL is the first P. falciparum ligand experimentally determined to be essential for this important step in the life cycle where the vector becomes infectious for transmitting sporozoites to people. With an increasing emphasis on advancing vector-based transgenic methods for suppression of malaria, it is important that this type of study, using modern molecular genetic tools, is done with the agent of the human disease. Understanding what P. falciparum sporozoite ligands are critical for mosquito transmission will help validate targets for vector-based transmission-blocking strategies

Intravital Observation of Plasmodium berghei Sporozoite Infection of the Liver

Plasmodium sporozoite invasion of liver cells has been an extremely elusive event to study. In the prevailing model, sporozoites enter the liver by passing through Kupffer cells, but this model was based solely on incidental observations in fixed specimens and on biochemical and physiological data. To obtain direct information on the dynamics of sporozoite infection of the liver, we infected live mice with red or green fluorescent Plasmodium berghei sporozoites and monitored their behavior using intravital microscopy. Digital recordings show that sporozoites entering a liver lobule abruptly adhere to the sinusoidal cell layer, suggesting a high-affinity interaction. They glide along the sinusoid, with or against the bloodstream, to a Kupffer cell, and, by slowly pushing through a constriction, traverse across the space of Disse. Once inside the liver parenchyma, sporozoites move rapidly for many minutes, traversing several hepatocytes, until ultimately settling within a final one. Migration damage to hepatocytes was confirmed in liver sections, revealing clusters of necrotic hepatocytes adjacent to structurally intact, sporozoite-infected hepatocytes, and by elevated serum alanine aminotransferase activity. In summary, malaria sporozoites bind tightly to the sinusoidal cell layer, cross Kupffer cells, and leave behind a trail of dead hepatocytes when migrating to their final destination in the liver