Contrasting taphofacies in ocean island settings: the fossil record of Mascarene vertebrates

Les Illes Mascarenyes, que comprenen Mauritius, La Réunion i Rodrigues, estan situades a l'Oceà Índic sud-occidental i són d'origen volcànic. Històricament, les illes estaven habitades per un nombre d'espècies endèmiques, el millor exemple de les quals és el dodó de Mauritius, Raphuts cucullatus. Encara que hi ha referències sobre l'ecologia de Mauritius als diaris i quaderns de bitàcola dels vaixells, no fou fins el descobriment dels primers materials fòssils que es va poder percebre la composició faunística original. A Mauritius, als aiguamolls de Mare aux Songes, el1865 varen ser descoberts nombrosos materials fòssils, mentre que es varen fer altres col·leccions a coves de valls poc fondes, particularment a la cadena muntanyenca de Le Pouce. A Rodrigues, les coves calcàries situades a la Plaine Corail han subministrat centenars de fòssils, principalment recol·lectats a les darreries del segle XIX. A La Réunion, les primeres restes fòssils varen ser descobertes el 1974, a talls dels penya-segats; s'ha trobat material subfòssil a aiguamolls i a localitats cavernícoles. Totes les restes fòssils són de l'Holocè. Alguns dels dipòsits fossilífers de les Mascarenyes presenten biaixos tafonòmics; en concret, els dipòsits dels aiguamolls són pobres en restes de petits vertebrats, com, per exemple, passerins. A Mauritius quasi no s'han trobat materials esquelètics a cap cova o tub volcànic, i els dipòsits de Mare aux Songes presenten biaixos elementals. A Rodrigues s'han conservat ocells marins, el solitari, Pezophaps solitaria, i la tortuga gegant, Cylindraspis sp., i relativament pocs ocells terrestres. Els sistemes cavernícoles i els tubs de lava són rars a Mauritius i La Réunion, i, a partir de les restes d'animals introduïts descobertes als tubs de lava de La Réunion, és clar que els elements esquelètics es degraden molt aviat. A més, als dipòsits d'aiguamolls s'han trobat centenars de restes de tortugues, mentre que, pel contrari, els ocells petits i de mida mitjana virtualment no s'hi troben. Aquest treball descriu la situació tafonòmica de diferents localitats fossilíferes i fa comparacions, emprant el microscopi electrònic d'escandallatge, entre espècimens fòssils de cada dipòsit. Es presenta evidència de la geologia, topografia, estratigrafia i sedimentologia, i es discuteixen els paleoambients, vida mitjana, carronyeig, activitat antropogènica, biaixos de recol·lecció i probabilitat d'entrampament, en relació amb la preservació dels elements. Malgrat els materials de les Mascarenyes són holocènics, els problemes que comporten són complexes, i la interpretació de qualsevol registre fòssil aparentment recent s'ha d'emprendre amb molta cura.The Mascarene Islands are situated in the southwest Indian Ocean and are volcanic in origin. Historically, the islands were inhabited by a number of endemic species, and although references were made about Mascarene ecology in ships' logs and journals, it was not until the discovery of the first fossil material that the diversity of the original fauna could be established. All of the fossil remains are Holocene. Some of the Mascarene fossil deposits exhibit marked taphonomic bias; in particular; the marsh and Réunion cave deposits are depauperate in small vertebrate remains, e.g. passerines, despite their presence being known from other evidence. On Rodrigues, comparatively few land birds other than solitaire Pezophaps solitaria and giant tortoise Cylindraspis sp. have been preserved. Cave systems and lava tunnels are rare on Mauritius and Réunion, and it is clear from the remains of introduced species found in such lava tunnels on Réunion that skeletal elements decay rapidly. This paper describes the taphonomic setting of the various fossil sites and makes comparisons using SEM and light microscopy between fossi! specimens from a range of deposits. Evidence from geology, topography, stratigraphy and sedimentology is presented and bioerosion, geochemistry, scavenging, collecting bias, entrapment and time-averaging are discussed in relation to element preservation. Although the Mascarene material is relatively young <5,000 years, the problems that can be encountered are complex; thus interpretation of any fossil record including recent ones must be approached with caution

A terrestrial vertebrate palaeontological review of Aldabra Atoll, Aldabra Group, Seychelles

The Pleistocene vertebrate assemblage of Aldabra Atoll has been comparatively well studied. Three Upper Pleistocene fossil localities have been described yielding birds, reptiles and terrestrial molluscs. Those of Bassin Cabri and Bassin Lebine on Ile Picard are undated but must be in excess of 136,000 YBP, whereas Point Hodoul on Malabar Island is circa 100,000 YBP. Aldabra was seemingly completely submerged between deposition of the Ile Picard and Point Hodoul deposits, resulting in local faunal extinctions. Here we present the results of an ongoing study of fossil material collected on Ile Picard in 1987, which reveals a more diverse assemblage than previously realised. Notable discoveries are an Ardeola heron, three Procellariformes, tropic-bird Phaethon, gull Larus, rail Dryolimnas, harrier Circus and owl Tyto, plus evidence of recolonisation of the atoll by some seabirds, rail, harrier, owl, giant tortoises and lizards after the Ile Picard/Point Hodoul submergence event

Silver segregation to \theta' (Al2Cu)-Al interfaces in Al-Cu-Ag alloys

\theta' (Al2Cu) precipitates in Al-Cu-Ag alloys were examined using high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). The precipitates nucleated on dislocation loops on which assemblies of {\gamma}' (AlAg2) precipitates were present. These dislocation loops were enriched in silver prior to \theta' precipitation. Coherent, planar interfaces between the aluminium matrix and \theta' precipitates were decorated by a layer of silver of two atomic layers in thickness. It is proposed that this layer lowers the chemical component of the Al-\theta' interfacial energy. The lateral growth of the \theta' precipitates was accompanied by the extension of this silver bi-layer, resulting in the loss of silver from neighbouring \gamma' precipitates and contributing to the deterioration of the \gamma' precipitate assemblies.Comment: Pre-print. 12 pages, 7 figure

Graft and Patient Survival in Kidney Transplant Recipients Selected for de novo Steroid-Free Maintenance Immunosuppression

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73689/1/j.1600-6143.2008.02442.x.pd

A review of the dodo and its ecosystem: insights from a vertebrate concentration Lagerstätte in Mauritius

The dodo Raphus cucullatus&nbsp;Linnaeus,1758, an extinct and flightless, giant pigeon endemic to Mauritius, has fascinated people since its discovery, yet has remained surprisingly poorly known. Until the mid-19th century, almost all that was known about the dodo was based on illustrations and written accounts by 17th century mariners, often of questionable accuracy. Furthermore, only a few fragmentary remains of dodos collected prior to the bird's extinction exist. Our understanding of the dodo's anatomy was substantially enhanced by the discovery in 1865 of subfossil bones in a marsh called the Mare aux Songes, situated in southeastern Mauritius. However, no contextual information was recorded during early excavation efforts, and the majority of excavated material comprised larger dodo bones, almost all of which were unassociated. Here we present a modern interdisciplinary analysis of the Mare aux Songes, a 4200-year-old multitaxic vertebrate concentration Lagerst&auml;tte. Our analysis of the deposits at this site provides the first detailed overview of the ecosystem inhabited by the dodo. The interplay of climatic and geological conditions led to the exceptional preservation of the animal and associated plant remains at the Mare aux Songes and provides a window into the past ecosystem of Mauritius. This interdisciplinary research approach provides an ecological framework for the dodo, complementing insights on its anatomy derived from the only associated dodo skeletons known, both of which were collected by Etienne Thirioux and are the primary subject of this memoir.Additional co-authors: Anneke H. Van Heteren, Vikash Rupear, Gorah Beebeejaun, Alan Grihault, J. (Hans) Van Der Plicht, Marijke Besselink, Juliën K. Lubeek, Max Jansen, Hege Hollund, Beth Shapiro, Matthew Collins, Mike Buckley, Ranjith M. Jayasena, Nicolas Porch, Rene Floore, Frans Bunnik, Andrew Biedlingmaier, Jennifer Leavitt, Gregory Monfette, Anna Kimelblatt, Adrienne Randall, Pieter Floore & Leon P. A. M. Claessen

Transcript Annotation in FANTOM3: Mouse Gene Catalog Based on Physical cDNAs

The international FANTOM consortium aims to produce a comprehensive picture of the mammalian transcriptome, based upon an extensive cDNA collection and functional annotation of full-length enriched cDNAs. The previous dataset, FANTOM2, comprised 60,770 full-length enriched cDNAs. Functional annotation revealed that this cDNA dataset contained only about half of the estimated number of mouse protein-coding genes, indicating that a number of cDNAs still remained to be collected and identified. To pursue the complete gene catalog that covers all predicted mouse genes, cloning and sequencing of full-length enriched cDNAs has been continued since FANTOM2. In FANTOM3, 42,031 newly isolated cDNAs were subjected to functional annotation, and the annotation of 4,347 FANTOM2 cDNAs was updated. To accomplish accurate functional annotation, we improved our automated annotation pipeline by introducing new coding sequence prediction programs and developed a Web-based annotation interface for simplifying the annotation procedures to reduce manual annotation errors. Automated coding sequence and function prediction was followed with manual curation and review by expert curators. A total of 102,801 full-length enriched mouse cDNAs were annotated. Out of 102,801 transcripts, 56,722 were functionally annotated as protein coding (including partial or truncated transcripts), providing to our knowledge the greatest current coverage of the mouse proteome by full-length cDNAs. The total number of distinct non-protein-coding transcripts increased to 34,030. The FANTOM3 annotation system, consisting of automated computational prediction, manual curation, and final expert curation, facilitated the comprehensive characterization of the mouse transcriptome, and could be applied to the transcriptomes of other species

A review of the dodo and its ecosystem: insights from a vertebrate concentration Lagerstätte in Mauritius

The dodo Raphus cucullatus Linnaeus, an extinct and flightless, giant pigeon endemic to Mauritius, has fascinated people since its discovery, yet has remained surprisingly poorly known. Until the mid-19th century, almost all that was known about the dodo was based on illustrations and written accounts by 17th century mariners, often of questionable accuracy. Furthermore, only a few fragmentary remains of dodos collected prior to the bird's extinction exist. Our understanding of the dodo's anatomy was substantially enhanced by the discovery in 1865 of subfossil bones in a marsh called the Mare aux Songes, situated in southeastern Mauritius. However, no contextual information was recorded during early excavation efforts, and the majority of excavated material comprised larger dodo bones, almost all of which were unassociated. Here we present a modern interdisciplinary analysis of the Mare aux Songes, a 4200-year-old multitaxic vertebrate concentration Lagerstätte. Our analysis of the deposits at this site provides the first detailed overview of the ecosystem inhabited by the dodo. The interplay of climatic and geological conditions led to the exceptional preservation of the animal and associated plant remains at the Mare aux Songes and provides a window into the past ecosystem of Mauritius. This interdisciplinary research approach provides an ecological framework for the dodo, complementing insights on its anatomy derived from the only associated dodo skeletons known, both of which were collected by Etienne Thirioux and are the primary subject of this memoir.publishedVersio

Trade and conservation implications of new beak and feather disease virus detection in native and introduced parrots

Psittacine beak and feather disease (PBFD), caused by Beak and feather disease virus (BFDV), has spread rapidly around the world, raising concerns for threatened species conservation and biosecurity risks associated with the global pet bird trade. BFDV has been reported in several wild parrot populations, but data is lacking for many taxa and geographical areas with high parrot endemism. This data deficit impedes the development of strategies to mitigate the threats posed by BFDV. We aimed to advance understanding of BFDV distribution in many data deficient areas and determine phylogenetic and biogeographic associations of the virus from five parrot species in Africa, the Indian Ocean islands, Asia and Europe. BFDV was detected in eight countries where it was not known to occur previously, indicating the virus is more widely distributed than currently recognised. We document for the first time the presence of BFDV in wild populations of the highly traded and invasive Psittacula krameri within its native range in Asia and Africa. BFDV was detected among introduced 15 P. krameri on the Indian Ocean islands of Mauritius and the Seychelles, raising concerns for island endemic species in the region. Examination of the phylogenetic relationships between viral sequences, including those detected among wild-sourced parrots seized from illegal trade in Western Africa, revealed likely pathways of transmission between populations. A close degree of phylogenetic relatedness between viral variants from geographically distant populations suggests recent introductions, likely driven by global trade. These findings highlight the need for effective regulation of international trade in live parrots, particularly in regions with high parrot endemism or vulnerable taxa where P. krameri could act as a reservoir host