Squamata phylogenomics and molecular evolution of venom proteins in Toxicofera

How frequent is convergent evolution? This fundamental question of evolutionary biology is challenging to address as it requires mapping innovations on a phylogeny. Phylogeny reconstruction methods, however, aim at reconstructing the tree with the minimum number of such events. Squamata the order of scaled reptiles composed of lizards, snakes, and amphisbaenians offers a striking example of such a conundrum. The Toxicofera hypothesis states that all venomous squamates such as iguanas, anguimorphs, and snakes are a monophyletic group, and that venom evolved only once in their last common ancestor, therefore constituting the only synapomorphy legitimating this group. Morphological and molecular phylogenetics of squamates in particular those of mitochondrial genes, however, result in distinct phylogenies supporting multiple convergent evolution of venomousness also because not all Toxicofera are venomous. Venom is composed of different proteins that are recruited into the venom from their original function after gene duplication. Thus, homologs of venom proteins are also found in non-venomous taxa. Thereby, the composition of Toxicofera venom resembles those of various other taxa which evolved venomousness multiple times convergently. Here, I aim for studying the molecular evolution of two venom proteins by first establishing a phylogenetic framework for the squamates group with a phylogenomic approach that makes use of all protein families in the RefSeq database of the NCBI that are available for at least 15 squamates resulting in a dataset containing 768 protein families for 272 species. I then use the resulting phylogeny to study the molecular evolution of two venom proteins independent of their single-gene phylogenies. I perform selection models of codon sequence evolution to detect variations in selection pressure between venomous and non-venomous clades. Additionally, I expect to find positively selected sites to be fast-evolving surface proteins that are co-adapting. Even though mitochondrial and nuclear phylogenies diverge a lot the results reveal evidence for multiple convergent evolutions of venom in Colubroidea, Anguimorpha, and Iguania. Venom proteins experience positive selection in snakes and anguimorphs but not in iguanas. Among positively selected sites are fast-evolving surface residues that are co-adapting with other residues. I conclude selection pressure acting on venom proteins is stronger in all Toxicofera except for Iguania compared to other squamates. This difference is not necessarily a consequence of heritability but to some extent affected by ecological factors like differences in diet

Earthen Architecture helping the victims of the 2007 flood in Bandiagara (Mali)

International audienceOn 4 July 2007, the river crossing the city of Bandiagara overflowed due to unusually heavy rains. Within few minutes, 194 families (nearly 1,500 people), witnessed the devastation of all or part of their homes and means of subsistence. At that time, the Cultural Mission of Bandiagara and CRAterre were collaborating in the framework of the project " Renforcement des capacités locales pour une meilleure contribution du secteur de la construction au développement durable du pays dogon " (Reinforcement of local capacities for a better contribution of the construction sector to the sustainable development of Dogon country) financed by the European Union; they called upon institutions to enable them to include, as part of their activities, a contribution to the reconstruction of basic housing structures. The German organization "Misereor" and the Abbé Pierre Foundation based in France responded positively by funding the reconstruction of 20 houses for sheltering the most affected families. The project was carried out in collaboration with the local Catholic Parish (Caritas), the municipality, the Flood Victims' Association, district chiefs, and the prefecture. A Committee was established to carefully select the 20 recipient families, which would commit to collecting materials from their affected properties and participate in the construction-training activities implemented. This reconstruction project benefited from the results of an inventory of the building cultures in Dogon country that included the study of land plots, building typologies and construction techniques. On the basis of these principles, twenty basic houses were designed and built, each with a different plan, defined by the types of materials recovered, the priorities identified by the families and the possibilities for future extensions. The reconstruction process was an opportunity to demonstrate and train workers to master innovative flood-proof building techniques and combine them with traditional practices

Earthen Architecture helping the victims of the 2007 flood in Bandiagara (Mali)

International audienceOn 4 July 2007, the river crossing the city of Bandiagara overflowed due to unusually heavy rains. Within few minutes, 194 families (nearly 1,500 people), witnessed the devastation of all or part of their homes and means of subsistence. At that time, the Cultural Mission of Bandiagara and CRAterre were collaborating in the framework of the project " Renforcement des capacités locales pour une meilleure contribution du secteur de la construction au développement durable du pays dogon " (Reinforcement of local capacities for a better contribution of the construction sector to the sustainable development of Dogon country) financed by the European Union; they called upon institutions to enable them to include, as part of their activities, a contribution to the reconstruction of basic housing structures. The German organization "Misereor" and the Abbé Pierre Foundation based in France responded positively by funding the reconstruction of 20 houses for sheltering the most affected families. The project was carried out in collaboration with the local Catholic Parish (Caritas), the municipality, the Flood Victims' Association, district chiefs, and the prefecture. A Committee was established to carefully select the 20 recipient families, which would commit to collecting materials from their affected properties and participate in the construction-training activities implemented. This reconstruction project benefited from the results of an inventory of the building cultures in Dogon country that included the study of land plots, building typologies and construction techniques. On the basis of these principles, twenty basic houses were designed and built, each with a different plan, defined by the types of materials recovered, the priorities identified by the families and the possibilities for future extensions. The reconstruction process was an opportunity to demonstrate and train workers to master innovative flood-proof building techniques and combine them with traditional practices

La conservation des grandes mosquées de Tombouctou

inclus dans l'ouvrage : Les pratiques de conservation traditionnelles en AfriqueInternational audienceThis article is describing the specific relationship between the monuents of Timbuktu with the population , the dignitaries, and also the masons of this historic city, inscribed on the world heritage list. It shows that these monuments are "living monuments" and raises a number of questions that need to be answered before deciding on how they should be conserved.Cet article décrit la relation spécifique qui existe entre les monuments de Tombouctou et la population, les dignitaires et surtout les maçons de cette ville historique inscrite au patrimoine de l'UNESCO. Il montre que ces monuments sont en fait des monuments vivant et expose la problématique de la mise en œuvre de leur bonne conservation

: A guide for African Local Governments

International audienceThe present guide is a very important contribution in this necessary effort to upgrade the capacities of the African local authorities in the field of management of both tangible and intangible heritages. It is one of the results of the partnership established between UNESCO, the French Senate and the PDM, echoing the "African Towns and Heritage" initiative launched at the occasion of the 2003 Africities Summit organised in Yaoundé. It provides tools to the municipalities and African local authorities which will allow them to start investing in a promising development field. Our wish is that it will be appreciated by the national and local authorities in Africa and that it will serve to launch everywhere a large movement favouring heritage and its valorisation, leading to a better representation of Africa on the World Heritage List

Equal Footing and the States Now Existing Slavery and State Equality Over Time

This Essay reexamines the question whether the Constitution empowered Congress to ban slavery in the territories. We explore that question by tracking two proposed additions to the Constitution, one that would empower Congress to ban the migration and importation of enslaved persons to all new states and territories and one that would oblige Congress to admit new states on an equal footing with the old. We show that the Federalists supported and the Convention adopted the migration provision, enabling Congress to restrict slavery to the states “now existing.” But the Federalists opposed and the Convention rejected the equal footing doctrine. Over time, things changed. In debates over the admission of Missouri to the Union as a slave state, Southerners offered a popular, if implausible, reinterpretation of the “Now Existing Caveat” to the Migration and Importation Provision that rendered it practically irrelevant to the expansion of slavery. What is more, Southerners pressed to extend a judge-made equal footing doctrine, urging that new states were entitled to legalize the ownership of people just as the old states were. Chief Justice Roger Taney wrote the Southern interpretation into the Constitution in the Dred Scott v. Sandford opinion, ignoring the Now Existing Caveat and embracing the equal footing doctrine as a matter of constitutional compulsion. While Dred Scott has not survived, the equal footing doctrine now undergirds the idea of equal state sovereignty in such U.S. Supreme Court decisions as Shelby County v. Holder. Meanwhile, the Federalist constitutional settlement has all but disappeared from view

Inventaire de l'architecture de terre du patrimoine mondial

International audienceL'architecture de terre est l'une des expressions les plus originales et les plus puissantes de notre capacité à créer un environnement construit avec des ressources locales facilement disponibles. Elle inclut une grande variété de structures, allant des mosquées, palais et greniers aux centres villes historiques, paysages culturels et sites archéologiques. Son importance culturelle dans le monde entier est évidente et a mené à sa considération en tant que patrimoine commun de l'humanité, méritant par suite la protection et la considération de la communauté internationale. En 2011, plus de 10% des biens culturels inscrits sur la Liste du patrimoine mondial incluaient des structures en terre. La disponibilité et la qualité économique du matériel contribue à la lutte contre la pauvreté et au développement durable. Toutefois, ces architectures de terre sont de plus en plus menacés par des impacts naturels et humains (e.g. inondations et séismes, industrialisation, urbanisation, technologies modernes de construction, disparition des pratiques traditionnelles de conservation, ....), et méritent par conséquent une attention particulière en termes de conservation et d'entretien ; environ ¼ des sites inscrits sur la Liste du patrimoine mondial en danger sont des sites en terre. Le Programme du patrimoine mondial pour l'architecture de terre (WHEAP) vise à l'amélioration de l'état de conservation et de gestion des sites architecturaux en terre à travers le monde. Des projets-pilotes menés sur des sites en terre inscrits sur la Liste du patrimoine mondial ou inclus dans les Listes indicatives d'Etats parties à la Convention aideront à identifier les meilleures pratiques. Ils fourniront des exemples pour le développement et la diffusion de méthodes et techniques appropriées dans la conservation et la gestion, et à renforcer les capacités locales. La recherche scientifique permettra en outre de promouvoir et d'améliorer le savoir-faire dans ce domaine. Les résultats attendus visent à une meilleure compréhension des problèmes auxquels est confrontée l'architecture de terre, au développement de politiques de conservation, à la définition de lignes directrices pratiques et à l'organisation d'activités de formation et de sensibilisation, en particulier auprès des communautés locales, à travers des ateliers, des expositions, des conférences et des publications techniques. Le programme cherche à accroitre la reconnaissance de l'architecture de terre et à créer un réseau mondial actif pour l'échange d'informations et d'expérience

Beeping a Deterministic Time-Optimal Leader Election

The beeping model is an extremely restrictive broadcast communication model that relies only on carrier sensing. In this model, we solve the leader election problem with an asymptotically optimal round complexity of O(D + log n), for a network of unknown size n and unknown diameter D (but with unique identifiers). Contrary to the best previously known algorithms in the same setting, the proposed one is deterministic. The techniques we introduce give a new insight as to how local constraints on the exchangeable messages can result in efficient algorithms, when dealing with the beeping model. Using this deterministic leader election algorithm, we obtain a randomized leader election algorithm for anonymous networks with an asymptotically optimal round complexity of O(D + log n) w.h.p. In previous works this complexity was obtained in expectation only. Moreover, using deterministic leader election, we obtain efficient algorithms for symmetry-breaking and communication procedures: O(log n) time MIS and 5-coloring for tree networks (which is time-optimal), as well as k-source multi-broadcast for general graphs in O(min(k,log n) * D + k log{(n M)/k}) rounds (for messages in {1,..., M}). This latter result improves on previous solutions when the number of sources k is sublogarithmic (k = o(log n))

Reconstruire Haïti après le séisme de janvier 2010: réduction des risques, cultures constructives et développement local

International audienceCet ouvrage présente une synthèse des résultats d'un travail mené par de nombreuses organisations haitiennes et internationales qui ont décidé de rassembler leurs forces en vue de répondre au mieux aux problèmes posés par la reconstruction de l'habitat suite au séisme de janvier 2010 en Haïti. L'approche qui y est proposée est issue de réflexions menées de concert lors de plusieurs rencontres internationales sur le sujet et que l'on peut résumer par la valorisation des cultures constructives locales afin d'apporter une meilleure réponse des programmes d'habita