Ichthyosaurs from the Early Cretaceous (Hauterivian - Barremian) from the western border of the Tyndall Glacier in the Torres del Paine National Park, Southernmost Chile

Three field campaigns to the eastern lobe of the Tyndall Glacier in the Torres del Paine National Park, southern Chile, allowed us to record 46 specimens of ichthyosaurs, which are almost completely exposed and articulated, as well as several associated faunal elements such as teleost and ganoid fishes, land plants, belemnites and ammonites. The fossil-bearing unit is part of the Uppermost Jurassic to Lower Cretaceous Zapata Formation (Tithonian to Albian, 151-112 Myr.) and is Valanginian to Hauterivian in age (140-130 Myr.), as indicated by the fossil assemblage. The concentration of numerous ichthyosaurs in this area is explained by turbidity flow events, which must repeatedly have caught the ichthyosaurs hunting fishes inside a submarine canyon. The flows transported the ichthyosaurs downslope into the deep ocean, from about 200 to possibly > 2000 m. Ichthyosaurs lost their orientation and were unable to return to the surface for oxygen. Some died during the transport and were immediately covered by turbidity sediment, while others were buried still alive; agony of these latter ichthyosaurs is expressed in the vertebral column of their skeleton. Isolated ichthyosaur elements such as fins, portions of vertebral column, or ribs, are explained by a previous partial decomposition of carcasses and posterior transport by the turbidity flows, with random distribution of bones along the canyon. Presence of pyrite and calcite in ichthyosaur skeletons suggest an early diagenesis. This process, together with a rapid and almost instantaneous burial, the absence of scavengers and low oxygen environment, contributed to the excellent preservation of the specimens, which even favored the preservation of soft tissue. Abrasion of retreating glaciers polished the ichthyosaur bones and exposed the skeleton. The topography of the area shows some portions of the skeleton exposed, while other continue embedded. The excavated specimens have demonstrated that the portions not exposed 'in situ' are contained in the sediment. The ichthyosaurs have been assigned to five different taxa: Myobradypterygius hauthali von Huene, 1927, ?Myobradypterygius hauthali, Ophthalmosauridae indet., Platypterygiinae indet. Arkhangelsky, 2001 (sensu Fischer et al., 2012)and Thunnosauria indet. The new cranial and postcranial material obtained from the Tyndall fossil locality allowed to emend the original diagnosis of Myobradypterygius hauthali and to disassociate it from the genus Platypterygius von Huene, to which Myobradypterygius was synonymized in 1972. The amount of specimens assigned to M. hauthali has allowed to reconstruct the anatomy of the complete animal and to differentiate five ontogenetical stages: adult, subadult, juvenile, neonate and embryo. M. hauthali was an edentulous Platypterygiinae ichthyosaur that shared the same ecological niche with dentate platypterygiines. According to internal content and pellets, both edentulous and dentate ichthyosaurs fed on fishes, using similar hunting strategies but differing in their mode of ingestion:dentate platypterygiines used their teeth to pierce the food whereas edentulous one smashed prey with their strong jaws. The cranium is exposed in five specimens and articulated postcranial elements are exposed in four. An isolated and articulated forefin is also present. These specimens were assigned to three yet undetermined taxa of Ophthalmosauridae based on a remarkable differentiation in shape and organization of elements of the hind fin. Likely the three taxa represent new species of ophthalmosaurid ichthyosaurs. Ophthalmosauridae indet. documented here show similarities in the configuration of fore-and hind fin with Undorosaurus spp. and Cryopterygius kristiansenae from the Volgian (Tithonian) of Russia and Norway, but differ from these in the shape of the zeugopodium and the anterior and posterior extensions of the fins. The similarities with these northern hemisphere species suggest a convergence forming a yet undocumented Undorosaurus-like clade. Specimens asigned as Thunnosauria indet. are distinguised by possessing a particular morphology of neural spines, which favored the attachment surface of epaxial musculature and therefore contributed to the increase in thrust force during swimming and thus an enhances capacity to dive. The differentiation between specimens having this thoracic anatomy from others where it is absent, such as M. hauthali, may have dictated a different behavior, reducing competition. Specimens with an evolved thorax have been shown to possess a forefin architecture similar to those of Middle-Lower Triassic to Upper Jurassic ichthyosaurs, suggesting that the fins of ichthyosaurs evolved independently from the axis of the body. Morphological similarities between the Tyndall ophthalmosaurid ichthyosaurs and species from the northern hemisphere help us to understand the Jurassic to Cretaceous ichthyosaur distribution around the globe and pathways that these marine reptilians may have taken for dispersal. In this context the Tyndall fossil locality has a privileged geographical location that contributes to the comprehension of the geotectonic fragmentation of Gondwana

An ichthyosaurian forefin from the Lower Cretaceous Zapata Formation of southern Chile: implications for morphological variability within Platypterygius

Fil: Pardo-Pérez, Judith. Institut für Geowissenschaften. Ruprecht Karls Universität Heidelberg. Heidelberg; GermanyFil: Frey, Eberhard. Staatliches Museum für Naturkunde Karlsruhe; GermanyFil: Stinnesbeck, Wolfgang. Institut für Geowissenschaften. Ruprecht Karls Universität Heidelberg. Heidelberg; GermanyFil: Fernández, Marta Susana. División Paleontología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Rivas, Luis. Departamento Ciencias de la Tierra. Universidad de Concepción; ChileFil: Salazar, Christian. Institut für Geowissenschaften. Ruprecht Karls Universität Heidelberg. Heidelberg; GermanyFil: Leppe, Marcelo. Instituto Antártico Chileno. Punta Arenas; Chil

New ophthalmosaurid ichthyosaurs from the European lower cretaceous demonstrate extensive ichthyosaur survival across the Jurassic–Cretaceous boundary

Background Ichthyosauria is a diverse clade of marine amniotes that spanned most of the Mesozoic. Until recently, most authors interpreted the fossil record as showing that three major extinction events affected this group during its history: one during the latest Triassic, one at the Jurassic–Cretaceous boundary (JCB), and one (resulting in total extinction) at the Cenomanian-Turonian boundary. The JCB was believed to eradicate most of the peculiar morphotypes found in the Late Jurassic, in favor of apparently less specialized forms in the Cretaceous. However, the record of ichthyosaurs from the Berriasian–Barremian interval is extremely limited, and the effects of the end-Jurassic extinction event on ichthyosaurs remains poorly understood. Methodology/Principal Findings Based on new material from the Hauterivian of England and Germany and on abundant material from the Cambridge Greensand Formation, we name a new ophthalmosaurid, Acamptonectes densus gen. et sp. nov. This taxon shares numerous features with Ophthalmosaurus, a genus now restricted to the Callovian–Berriasian interval. Our phylogenetic analysis indicates that Ophthalmosauridae diverged early in its history into two markedly distinct clades, Ophthalmosaurinae and Platypterygiinae, both of which cross the JCB and persist to the late Albian at least. To evaluate the effect of the JCB extinction event on ichthyosaurs, we calculated cladogenesis, extinction, and survival rates for each stage of the Oxfordian–Barremian interval, under different scenarios. The extinction rate during the JCB never surpasses the background extinction rate for the Oxfordian–Barremian interval and the JCB records one of the highest survival rates of the interval. Conclusions/Significance There is currently no evidence that ichthyosaurs were affected by the JCB extinction event, in contrast to many other marine groups. Ophthalmosaurid ichthyosaurs remained diverse from their rapid radiation in the Middle Jurassic to their total extinction at the beginning of the Late Cretaceous

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

¿Qué queda de mí?

Este libro es una reclamación a quienes hemos sido, somos o seremos docentes. A quienes no hemos respetado a las personas que se han puesto junto a nosotros y nosotras, confiando su bien más preciado: la libertad. Estas páginas denuncian cada vez que convertimos una visión en la visión, una emoción en la emoción, un saber en el saber, un comportamiento en el comportamiento. Es un grito contra la imposición, la normalización, la neutralización y la universalización de una perspectiva particular. Una pugna contra cada proceso que no se ha conectado con las vidas de los aprendices. Un texto colaborativo realizado por alumnado de Educación y Cambio Social en el Grado en Educación Infantil de la Universidad de Málaga y coordinado por Ignacio Calderón Almendros

Impact of infection on proteome-wide glycosylation revealed by distinct signatures for bacterial and viral pathogens

Mechanisms of infection and pathogenesis have predominantly been studied based on differential gene or protein expression. Less is known about posttranslational modifications, which are essential for protein functional diversity. We applied an innovative glycoproteomics method to study the systemic proteome-wide glycosylation in response to infection. The protein site-specific glycosylation was characterized in plasma derived from well-defined controls and patients. We found 3862 unique features, of which we identified 463 distinct intact glycopeptides, that could be mapped to more than 30 different proteins. Statistical analyses were used to derive a glycopeptide signature that enabled significant differentiation between patients with a bacterial or viral infection. Furthermore, supported by a machine learning algorithm, we demonstrated the ability to identify the causative pathogens based on the distinctive host blood plasma glycopeptide signatures. These results illustrate that glycoproteomics holds enormous potential as an innovative approach to improve the interpretation of relevant biological changes in response to infection

Relationship between molecular pathogen detection and clinical disease in febrile children across Europe: a multicentre, prospective observational study

BackgroundThe PERFORM study aimed to understand causes of febrile childhood illness by comparing molecular pathogen detection with current clinical practice.MethodsFebrile children and controls were recruited on presentation to hospital in 9 European countries 2016-2020. Each child was assigned a standardized diagnostic category based on retrospective review of local clinical and microbiological data. Subsequently, centralised molecular tests (CMTs) for 19 respiratory and 27 blood pathogens were performed.FindingsOf 4611 febrile children, 643 (14%) were classified as definite bacterial infection (DB), 491 (11%) as definite viral infection (DV), and 3477 (75%) had uncertain aetiology. 1061 controls without infection were recruited. CMTs detected blood bacteria more frequently in DB than DV cases for N. meningitidis (OR: 3.37, 95% CI: 1.92-5.99), S. pneumoniae (OR: 3.89, 95% CI: 2.07-7.59), Group A streptococcus (OR 2.73, 95% CI 1.13-6.09) and E. coli (OR 2.7, 95% CI 1.02-6.71). Respiratory viruses were more common in febrile children than controls, but only influenza A (OR 0.24, 95% CI 0.11-0.46), influenza B (OR 0.12, 95% CI 0.02-0.37) and RSV (OR 0.16, 95% CI: 0.06-0.36) were less common in DB than DV cases. Of 16 blood viruses, enterovirus (OR 0.43, 95% CI 0.23-0.72) and EBV (OR 0.71, 95% CI 0.56-0.90) were detected less often in DB than DV cases. Combined local diagnostics and CMTs respectively detected blood viruses and respiratory viruses in 360 (56%) and 161 (25%) of DB cases, and virus detection ruled-out bacterial infection poorly, with predictive values of 0.64 and 0.68 respectively.InterpretationMost febrile children cannot be conclusively defined as having bacterial or viral infection when molecular tests supplement conventional approaches. Viruses are detected in most patients with bacterial infections, and the clinical value of individual pathogen detection in determining treatment is low. New approaches are needed to help determine which febrile children require antibiotics.FundingEU Horizon 2020 grant 668303

Genomic investigations of unexplained acute hepatitis in children

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

Análisis de las principales implicaciones ambientales por la explotación minera en los sectores del suroriente de Bogotá por mal manejo de los cierres y abandonos al término de la explotación ejecutada

Desde finales de la década de 1990 e inicios de los 2000, Bogotá ha crecido de manera poco planificada en cuanto a infraestructura y construcción. La sabana donde se encuentra ubicada la ciudad es de litología sedimentaria, en pocas palabras, es de gran riqueza en materiales necesarios para el desarrollo de obras civiles y el sector de la construcción. El factor litológico auspicio el inicio de explotaciones mineras en el sur de la ciudad, ubicándose en la cuenca del río Tunjuelo, siendo las de esta zona las de mayor importancia. El desorden y lento desarrollo de la legislación minera y ambiental, la falta de seguimiento a la actividad minera en la ciudad y su territorio, no definir una buena planeación que incluya los usos de los suelos de la ciudad, el auge minero y la ilegalidad, generaron una situación de desarrollo minero en donde alrededor del 90 % de las canteras en explotación en el territorio urbano y rural de la ciudad están en términos de la ilegalidad (El Tiempo, 2016), que afecta visiblemente y de manera directa a la población aledaña, los recursos hídricos y ambientales aledaños a las explotaciones mineras. Debido a esta problemática, en la administración distrital de Gustavo Petro, se decidió prohibir la actividad minera en la ciudad (Secretaría de Ambiente, 2012), que si bien fue un hecho determinante, en sí no fue totalmente la solución, dado que por un mandato del Consejo de Estado, y petición de la Alcaldía Mayor de Bogotá, el Ministerio de Ambiente debe definir la ubicación y gran parte de la situación de esas zonas para hacer frente a las canteras ilegales y las problemáticas socio-ambientales que ha generado la actividad minera. El impacto ambiental causado por la explotación en las canteras ha llevado a la necesidad de analizar esta problemática causada en Bogotá, he aquí porque los estudiantes de Ingeniería de Minas quieren estudiar una alternativa para poder remediar el impacto ambiental producido por el abandono mal realizado al fin de la explotación