Taphonomy

Trabajo presentado en el II International Symposium on Lithographic Limestones celebrado en Cuenca.-- Field trip guide book.The taphonomic anal ysis of the Las Hoyas site is still at an early stage. This analysis is necessary since it is considered a prerequisite for paleoecological reconstructions (Shipman, 1981). Besides, taphonomic analysis has its own aims; in this case they could be summarized as the establishment of the temporal succession of processes which led to the formation of the site.Peer reviewe

Epidemiological trends of HIV/HCV coinfection in Spain, 2015-2019

Altres ajuts: Spanish AIDS Research Network; European Funding for Regional Development (FEDER).Objectives: We assessed the prevalence of anti-hepatitis C virus (HCV) antibodies and active HCV infection (HCV-RNA-positive) in people living with HIV (PLWH) in Spain in 2019 and compared the results with those of four similar studies performed during 2015-2018. Methods: The study was performed in 41 centres. Sample size was estimated for an accuracy of 1%. Patients were selected by random sampling with proportional allocation. Results: The reference population comprised 41 973 PLWH, and the sample size was 1325. HCV serostatus was known in 1316 PLWH (99.3%), of whom 376 (28.6%) were HCV antibody (Ab)-positive (78.7% were prior injection drug users); 29 were HCV-RNA-positive (2.2%). Of the 29 HCV-RNA-positive PLWH, infection was chronic in 24, it was acute/recent in one, and it was of unknown duration in four. Cirrhosis was present in 71 (5.4%) PLWH overall, three (10.3%) HCV-RNA-positive patients and 68 (23.4%) of those who cleared HCV after anti-HCV therapy (p = 0.04). The prevalence of anti-HCV antibodies decreased steadily from 37.7% in 2015 to 28.6% in 2019 (p < 0.001); the prevalence of active HCV infection decreased from 22.1% in 2015 to 2.2% in 2019 (p < 0.001). Uptake of anti-HCV treatment increased from 53.9% in 2015 to 95.0% in 2019 (p < 0.001). Conclusions: In Spain, the prevalence of active HCV infection among PLWH at the end of 2019 was 2.2%, i.e. 90.0% lower than in 2015. Increased exposure to DAAs was probably the main reason for this sharp reduction. Despite the high coverage of treatment with direct-acting antiviral agents, HCV-related cirrhosis remains significant in this population

Historia del vuelo aviano

Not available.El análisis del registro fósil proporciona información sobre la historia evolutiva del aparato volador aviano y el origen y desarrollo del vuelo moderno. Existen dos hipótesis alternativas para explicar las complejas presiones de selección que configuraron la aparición del vuelo. La propuesta del corredor («desde el suelo hacia arriba») es la que mejor se ajusta a la evidencia disponible. El ave primitiva Archaeopteryx produciría, probablemente, algún tipo de vuelo batido, aunque su capacidad de maniobra, despegue y aterrizaje sería limitada. El vuelo activo moderno comenzó, durante el Cretácico inferior, con las aves ornitotoraces basales, como Iberomesornis. No obstante, esta ave primitiva, cuya capacidad de vuelo estaba claramente incrementada con respecto a la condición ancestral presente en Archaeopteryx, tampoco parece tener las perfectas habilidades voladoras de las aves modernas

Pattern of biotic replacement in modern crocodiles during the Late Cretaceous

Se revisa en detalle el registro fósil de crocoylomorfos del Cretácico Superior con el fin de examinar el reemplazamiento biótico que supuso la aparición de los miembros del clado Crocodylia. Para ello se ha estimado cronoestratigráficamente y por continentes el porcentaje de crocodylianos (cocodrilos modernos miembros del "crown-group" Crocodylia) y de crocodylomorfos no-crocodylianos. En el Cretácico Superior hay una proporción elevada de géneros no-crocodylianos (71%). Sin embargo, el porcentaje de crocodylianos se incrementa de un 6% en el Cenomaniense-Santoniense a un 22% en el intervalo Campaniense-Maastrichtiense. Crocodylia se caracteriza... (Ver más) por presentar una pauta propia de una radiación expansiva, que no implica el desplazamiento geográfico de los crocodylomorfos no-crocodylianos. La distribución cronoestratigráfica de los géneros de Crocodylia se restringe principalmente a localidades datadas como Campaniense y Maastrichtiense. Los crocodylomorfos no muestran una distribución espacial uniforme entre continentes. Se distinguen dos tipos de patrones: 1) Europa y Norte América, caracterizados por una alta proporción de géneros del clado Crocodylia, sobrepasando el 50% del número total de géneros, y 2) Asia, Sudamérica y Africa, todos con proporciones semejantes, donde Crocodylia representa menos del 15% del número total de géneros. Se propone para Crocodylia una radiación expansiva a gran escala localizada en Europa y Norte América hacia el final del Cretácico terminal. Este reemplazamiento biótico sucede en ambiente continental. La ausencia de miembros del clado Crocodylia en Asia, Africa y Sudamérica es significativa, ya que los no-crocodylianos están, por el contra, bien documentados a lo largo de todo el Cretácico Superior. Las disimilitudes taxonómicas entre continentes son tales que no se comparte ningún género.The Late Cretaceous crocodylomorph record is revised in detail in order to examine the biotic replacement that characterises the appearance of the members of the Crocodylia clade. The percentages of crocodylian and non-crocodylian genera have been estimated by chronostratigraphic stage and by continent. The results show that there are a higher proportion of non-crocodylians genera (71%) in the Late Cretaceous. However, the percentage of Crocodylia increases from 6% in the Cenomanian - Santonian to 22% in the Campanian - Maastrichtian interval. Crocodylia have a pattern of expansive radiation, without involving a geographic shift of non-crocodylians... (Ver más) crocodylomorph. The chronostratigraphic distribution of the crocodylian genera is mostly restricted to Campanian-Maastrichtian localities. Crocodylians have a non-uniform spatial distribution among continents. Two different patterns are distinguished: 1) Europe plus North America, characterised by a high proportion of Crocodylia, exceeding 50% of the total number of genera, and 2) Asia, South America and Africa, all of which have similar proportions, in which the crocodylians form less than 15% of the crocodylomorph assemblage. A large-scale expansive radiation and diversification of crocodylians is postulated for Europe and North America at the uppermost Cretaceous. The bulk of the biotic replacement occurs in the continental realm. The absence of continental members of Crocodylia in Asia, Africa and South America is significant because non-crocodylians are otherwise well-documented throughout the Upper Cretaceous. Taxonomic dissimilarity between continents is so high that no continental genera are shared between continents

Dinosaurios

7 páginas con información sobre las conferencias realizadas.Seminario con salida al campo organizado por la Sociedad de Amigos del Museo Nacional de Ciencias Naturales en marzo de 2001.N

An early Cretaceous pellet

Peer Reviewe

Brief Communications

We have discovered a mass of fossil bones from four juvenile birds at Las Hoyas in Cuenca, Spain, which show signs of having been digested. To our knowledge, this rare finding of an Early Cretaceous fossil of an apparently regurgitated pellet provides the first evidence that Mesozoic birds were prey animals.Peer reviewe

An Early Cretaceous pellet

We have discovered a mass of fossil bones from four juvenile birds at Las Hoyas in Cuenca, Spain, which show signs of having been digested. To our knowledge, this rare finding of an Early Cretaceous fossil of an apparently regurgitated pellet provides the first evidence that Mesozoic birds were prey animals.Peer reviewe