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International audience; Miocene vertebrate localities are uncommon in central South America. In Bolivia, the best known mammalian faunas ofthis period come from Quebrada Honda (late middle Miocene, Tarija Department) and Cerdas (early middle Miocene, PotosíDepartment). The Achiri locality (La Paz Department) was reported first by Hoffstetter in 1972. Subsequently, campaignswere conducted in this locality by several paleontologists, including Villarroel, Anaya, Saint-André, and by our team over thelast decade. Recently, we have obtained two precise absolute dates (40Ar/39Ar) on feldspar contained in ashes intercalatedbetween fossiliferous levels and confirmed a late Miocene age (10.35±0.07 Ma and 10.42±0.09 Ma, late Mayoan–earlyChasicoan South American Land Mammal Ages) as suggested by Marshall and colleagues in 1983. Almost all the specimenscome from the Cerros Virgen Pata and Jiska/Jacha Pisakeri localities, the latter located 3–4 km southeast of Achiri village.In the past, discoveries of numerous spectacular specimens have allowed the identification of new mammalian speciessuch as the notoungulates Plesiotypotherium achirense and Hoffstetterius imperator, the sparassodontan Borhyaenidiumaltiplanicum, and the xenarthrans Trachycalyptoides achirense and Xyophorus villarroeli. Xyophorus was erected by Ameghinoin 1887 on the basis of a dentary fragment from the lower Miocene Santa Cruz Formation (Argentina). This taxon is generallyconsidered to be a nothrotheriid sloth (although has never been formally included in a phylogenetic analysis based onosteological characters). Six species are recognized in Argentina. This genus is also recorded in Achiri through the endemicspecies X. villarroeli, and also in Cerdas and Quebrada Honda through X. cf. bondesioi. Unfortunately, all the specimensreferred to Xyophorus are extremely fragmentary. Here we present a partial skull (MNHN-Bol-V 12690, National Museumof Natural History, La Paz, Bolivia) discovered in Achiri, belonging to an adult, and referred as “Xyophorus” villarroeli. Itconsists of a right posterolateral portion of the skull, including parts of squamosal, parietal, basioccipital, exoccipital, andits complete ear region with ectotympanic, entotympanic, and petrosal. Preliminary observations of this new specimenreveal the presence of at least seven autapomorphies, including a very rugose external surface of ectotympanic, a clearcontact between styliform process of ectotympanic and pterygoid, and a reduced or absent subarcuate fossa. Thismegatherioid sloth shares several synapomorphies with nothrotheriids, including a dorsoventrally elongated ectotympanicand an ovate stylohyal fossa. It exhibits also transitional features between basal megatherioids and nothrotheriids, like aventral portion of the ectotympanic that is expanded transversely in ventral view (more than Hapalops and less thanNothrotheriidae) and deeper in lateral view than that of Hapalops, although similar in proportions to Pronothrotherium andMionothropus. This specimen thus suggests that “Xyophorus” villarroeli could be an early-diverging nothrothere, withaffinities to Hapalops and also early Nothrotheriidae, and probably distinct from Xyophorus of more austral localities. Acomprehensive phylogenetic analysis of the Megatherioidea including this form from Achiri, Aymaratherium from the earlyPliocene of Pomata-Ayte, and Lakukullus and Hiskatherium from Quebrada Honda, should allow for a better understandingof the relationships among Patagonian and Andean Megatherioidea.

International audience; Among armored xenarthrans, Glyptodontidae appears as one of the most peculiar and also characteristic groups of SouthAmerican mammals that inhabited this continent since at least the early Eocene until the end of the Pleistocene. Theirevolutionary history is particularly well documented in Patagonia, Central and North America, but less so in the tropics andcentral South America. In Bolivia during the Miocene epoch, this family is only recorded at the Laventan locality of QuebradaHonda, represented by cf. “Asterostemma”, “Propalaehoplophorus” andinus, and two sclerocalyptine species, the ?Colloncuranlocality of Nazareno represented by “Propalaehoplophorus” and ?Neothoracophorus, occurring in Choquecota, and the lateMayoan–early Chasicoan localities of Chokorasi and Achiri by a single species, Trachycalyptoides achirense. The late Miocenevertebrate locality of Achiri discovered in the early 70’s by the French paleontologist Hoffstetter, was explored by severalteams during the subsequent decades. Its mammalian fauna is particularly diverse with more than 20 taxa, includingmetatherians (i.e., Borhyaenidium), notoungulates (e.g., Hoffstetterius), litopterns, rodents (e.g., Prolagostomus), as well asxenarthrans sloths (e.g., “Xyophorus”) and cingulates (e.g., Trachycalyptoides). Trachycalyptoides was erected by Saint-Andréin 1996 on the basis on two dermal armors and caudal tubes, an incomplete skull, and a hemimandible. The abundantmaterial collected by our team during recent fieldwork, and the preliminary revision of the material housed in the museumsof La Paz and Paris, has allowed us to gather new information, specifically on the dentition, dorsal carapace, and caudal tubeon this peculiar glyptodontid. In Trachycalyptoides the presence of three lobes is well marked on certain upper and lowermolariforms, especially on the most posterior teeth (fourth to eighth molariforms), whereas their presence is doubtful onthe third teeth, and absent on the first and second teeth. The general structure of the osteoderms corresponds to apentagonal or hexagonal polygon with a “rosette” pattern (a central figure surrounded by peripheral figures) on the exposedsurface. The central and peripheral figures are elevated and separated by a sulcus. The subcircular central figure is slightlyconcave in the center. The peripheral figures are small and in a variable number according to region (ranging from 3–4 to12–15), with foramina at the intersection with the sulcus of the central figure. The caudal tube is conical and elongated andits apex is relatively acute. The ventral face is slightly convex and the dorsal face is flat. The distal portion of the tube isformed by two large right and left osteoderms. The latter are roughly quadrangular, rectangular proximally and quadratedistally. The osteoderms of the caudal tube lack peripheral figures. The molariforms, dorsal carapace, and caudal tube ofTrachycalyptoides show affinities with glyptodonts that have a simplified trilobate pattern in the anteriormost molariforms,a dorsal carapace formed by osteoderms with a “rosette” pattern, and a caudal tube formed by osteoderms withoutperipheral figures like Cochlops, Palaehoplophorus, Trachycalyptus, and Lomaphorus.

International audience; El conocimiento de los mamíferos neógenos de Bolivia se ha centrado principalmente en unos pocos yacimientos del Mioceno temprano (Cerdas, Nazareno) y el Mioceno medio (Quebrada Honda). En la última década, se han incrementado los esfuerzos de exploración, dando como resultado un mejor conocimiento de la fauna de la localidad de Achiri (Prov. de Pacajes) del Mioceno tardío (~10,42–9,42 Ma; Formación Mauri). Dentro de esta fauna, los especímenes de caviomorfos, depositados en la Unidad de Paleontología del Museo Nacional de Historia Natural de La Paz, son abundantes y consisten en restos cráneo-mandibulares y post-craneanos, y dientes aislados. El estudio preliminar indica la presencia de Prodolichotis prisca, Cardiomys sp. (Cavioidea), Tetrastylus sp., Lagostomus sp. (Chinchilloidea) y un octodontoideo indet. Prodolichotis abarca el 80% de la diversidad, con cráneos excepcionalmente preservados (varios asociados a mandíbulas). Los otros taxones están representados por especímenes que, aunque escasos y fragmentarios, permiten una asignación genérica clara (excepto el octodontoideo por su mala preservación). Prodolichotis prisca es el dolicotino más antiguo, registrado en el Mioceno tardío–Plioceno temprano del noroeste de Argentina. Cardiomys, Tetrastylus y Lagostomus se encuentran ampliamente distribuidos en niveles del Neógeno tardío de Argentina. Además, Tetrastylus se registra en el Mioceno tardío de Brasil, Uruguay y Venezuela. Aunque es necesario un análisis profundo de la taxonomía de los roedores de Achiri, los mismos indican mayor afinidad con las faunas de edad Chasiquense-Huayqueriense de Argentina. El estudio de esta asociación permitirá aumentar el conocimiento biogeográfico del Neógeno tardío de América del Sur.

International audience; Las faunas de mamíferos continentales provenientes del Paleógeno de América del Sur son relativamente escasas,especialmente en las zonas tropicales e intertropicales. En Bolivia la localidad fosilífera de Lacayani, cercana a la ciudad deLa Paz y a 50 km al NE del yacimiento de Salla, fue descubierta en 1969 por geólogos de Francia y Bolivia. A partir de unostreinta especímenes, Hoffstetter y colegas presentaron en 1971 una lista faunística preliminar para Lacayani, identificandonueve mamíferos: Borhyaenidae (esparasodonte), cf. Prozaedyus (armadillo), Glyptatelus (gliptodonte), “orofodóntido”(perezoso), cf. Scatomys y Eocardiidae (roedores), cf. Coniopternum (litopterno), Trachytherus cf. spegazzinianus yProhegetotherium (notoungulados). Sobre la base de esta asociación, los autores dedujeron que la fauna de Lacayani eracontemporánea a la de Salla (Deseadense). En 1989, Vucetich revisó los roedores publicados y los reasignó como Eoviscacciaboliviana y Cephalomyidae indet. En 2008, Billet y colaboradores indicaron que el mesotérido Trachytherus spegazzinianus,presente en Lacayani, era distinto de la especie registrada en Salla (T. alloxus). Recientemente se realizaron tres campañasdurante las cuales se recolectaron nuevos materiales, en su mayoría escasos y fragmentarios. El yacimiento, que seencuentra en las afueras del pueblo de Lacayani, tiene una extensión de algunos cientos de metros cuadrados. El úniconivel fosilífero está constituido por limos finos, arcillosos y rojos con una toba intercalada en su centro. Los especímenesse hallaron in situ y en superficie. La revisión de los nuevos materiales y aquellos depositados en París permitieron identificarmás de 400 especímenes. Los roedores constituyen más de la mitad de los ejemplares y están representados por cuatrochinchilloideos: Eoviscaccia boliviana (la más abundante), E. cf. autralis, posiblemente Eoviscaccia sp. nov. y Cephalomyopsissp.; y un octodontoideo representado por un premolar superior generalizado. Los ungulados son menos abundantes (15%de los especímenes) con tres notoungulados: el mesotérido Trachytherus spegazzinianus (el más común), Pachyrukhinaeindet. (Hegetotheriidae) y cf. Adinotherium (Toxodontidae); y el macrauquénido Coniopternum (Litopterna). Los dos únicosrestos de metaterios pertenecen a distintos géneros de Hathliacynidae. Los xenartros (20% de los especímenes) estánprincipalmente representados por cingulados y un perezoso milodóntido estrechamente relacionado con Octodontotherium.Los xenartros acorazados están representados por numerosos restos de los Dasypodidae eufractinos Isutatetus sp. nov. yAmblytatus sp. nov., placas aisladas del gliptodóntido Glyptatelus y un único resto asignable probablemente a un paleopéltido.Un ave catártido completa la fauna de vertebrados. La localidad de Lacayani tiene una importancia fundamental para elconocimiento de la evolución de los mamíferos en América del Sur por su posición geográfica en el centro del continente,por su proximidad con la localidad de Salla y por probablemente llenar un hiato entre las faunas deseadenses ycolhuehuapenses. Por el momento la fauna de Lacayani indica los siguientes resultados preliminares: i) se reconocen 16especies de mamíferos, ii) únicamente cuatro taxones están presentes también en Salla, iii) ocho taxones sonexclusivamente paleógenos, dos neógenos y cuatro serían autóctonos. Finalmente, dataciones basadas en feldespatosprovenientes de la toba intercalada dentro del nivel fosilífero sugieren una edad más joven que en Salla.

BACKGROUND: Perioperative corticosteroid use may reduce acute kidney injury. We sought to test whether methylprednisolone reduces the risk of acute kidney injury after cardiac surgery. METHODS: We conducted a prespecified substudy of a randomized controlled trial involving patients undergoing cardiac surgery with cardiopulmonary bypass (2007-2014); patients were recruited from 79 centres in 18 countries. Eligibility criteria included a moderate-to-high risk of perioperative death based on a preoperative score of 6 or greater on the European System for Cardiac Operative Risk Evaluation I. Patients (n = 7286) were randomly assigned (1:1) to receive intravenous methylprednisolone (250 mg at anesthetic induction and 250 mg at initiation of cardiopulmonary bypass) or placebo. Patients, caregivers, data collectors and outcome adjudicators were unaware of the assigned intervention. The primary outcome was postoperative acute kidney injury, defined as an increase in the serum creatinine concentration (from the preoperative value) of 0.3 mg/dL or greater (≥ 26.5 μmol/L) or 50% or greater in the 14-day period after surgery, or use of dialysis within 30 days after surgery. RESULTS: Acute kidney injury occurred in 1479/3647 patients (40.6%) in the methylprednisolone group and in 1426/3639 patients (39.2%) in the placebo group (adjusted relative risk 1.04, 95% confidence interval 0.96 to 1.11). Results were consistent across several definitions of acute kidney injury and in patients with preoperative chronic kidney disease. INTERPRETATION: Intraoperative corticosteroid use did not reduce the risk of acute kidney injury in patients with a moderate-to-high risk of perioperative death who had cardiac surgery with cardiopulmonary bypass. Our results do not support the prophylactic use of steroids during cardiopulmonary bypass surgery. Trial registration: ClinicalTrials.gov, no. NCT00427388. ispartof: CANADIAN MEDICAL ASSOCIATION JOURNAL vol:191 issue:9 pages:E247-E256 ispartof: location:Canada status: published

Background Safely reducing red blood cell transfusions can prevent transfusion-related adverse effects, conserve the blood supply, and reduce health care costs. Both anemia and red blood cell transfusion are independently associated with AKI, but observational data are insufficient to determine whether a restrictive approach to transfusion can be used without increasing AKI risk. Methods In a prespecified kidney substudy of a randomized noninferiority trial, we compared a restrictive threshold for red blood cell transfusion (transfuse if hemoglobin= 0.3 mg/dl within 48 hours of surgery, or >= 50% within 7 days of surgery. Results Patients in the restrictive-threshold group received significantly fewer transfusions than patients in the liberal-threshold group (1.8 versus 2.9 on average, or 38% fewer transfusions in the restricted threshold group compared with the liberal-threshold group; P

Dado en bogotá, a 4 de octubre de 1872: Dirección i organización de las clases - Enseñanzas - Exámenes - Sueldos - Disposiciones varias

Se establecen los horarios del medio batallón de Artillería.

[EN] Mo-V-X (X = Nb, Sb and/or Te) mixed oxides have been prepared by hydrothermal synthesis and heat-treated in N(2) at 450 degrees C or 600 degrees C for 2 h. The calcination temperature and the presence or absence of Nb determines the nature of crystalline phases in the catalyst. Nb-containing catalysts heat-treated at 450 degrees C are mostly amorphous solids, while Nb-free catalysts heat-treated at 450 degrees C and samples treated at 600 degrees C clearly contain crystalline phases. TPR-H(2) experiments show higher H(2)-consumption on catalysts with amorphous phases. Catalytic results in the oxidative dehydrogenation of ethane indicate that the selective production of the olefin is strongly related to the development of the orthorhombic Te(2)M(20)O(57) or (SbO)(2)M(20)O(56) (M = Mo, V, Nb) phase (the so-called M1 phase), which is mainly formed at 600 degrees C. This active and selective crystalline phase is characterized to show moderate reducibility and active centers enough for the selective oxidative activation of ethane with the minimum quantity possible of active centers for ethylene activation. In this sense, the best yield to ethylene has been achieved on a Mo-V-Te-Nb mixed oxide. (C) 2008 Elsevier B.V. All rights reserved., Financial support from DGICYT in Spain through Project CTQ2006-09358/BQU is gratefully acknowledged. P. B. also thanks the program Ramo´n y Cajal from Spain.