35 research outputs found

    Cubic pencils of lines and bivariate interpolation

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    AbstractCubic pencils of lines are classified up to projectivities. Explicit formulae for the addition of lines on the set of nonsingular lines of the pencils are given. These formulae can be used for constructing planar generalized principal lattices, which are sets of points giving rise to simple Lagrange formulae in bivariate interpolation. Special attention is paid to the irreducible nonsingular case, where elliptic functions are used in order to express the addition in a natural form

    Unusual theropod eggshells from the early cretaceous blesa formation of the Iberian Range, Spain

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    Trigonoolithus amoae oogen. et oosp. nov. is described on the basis of abundant eggshell fragments from the La Cantalera 1 site in the Early Cretaceous (early Barremian) Blesa Formation, Teruel Province, northern Spain. The surface ornamentation, the most diagnostic feature of the new oogenus, consists of closely spaced sub-triangular or rounded protuberances that have not previously been reported in any other ootaxon. The eggshells present three distinct layers, with a gradual transition between prismatic and mammillary layers, and a poorly developed external layer with progressive prismatic to external layer transition, a combination of characters that allows them to be assigned to Prismatoolithidae. Phylogenetic analyses based on oological characters place Trigonoolithus at the base of Prismatoolithidae

    New material and phylogenetic position of the basal iguanodont dinosaur Delapparentia turolensis from the Barremian (Early Cretaceous) of Spain

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    a partial postcranial skeleton discovered in the 1950s near the village of Galve (Teruel Province), within the Camarillas Formation. Recently, new remains from the same individual have been recovered, and these are described here. Furthermore, after first-hand examinations of the holotype, the phylogenetic position of this taxon has been analysed for the first time, and its diagnosis is emended. Delapparentia turolensis is a large-sized, basal iguanodont which presents an autapomorphic, unusually high axial neural spine and a unique combination of postcranial characters. The ilium morphology differs from that of other basal iguanodonts and relates Delapparentia to the Valanginian Barilium dawsoni from England, with whom it shares two synapomorphies. In our phylogenetic analysis Delapparentia is recovered in a polytomy with Kukufeldia, Lanzhousaurus, Barilium and the clade equivalent to Iguanodontoidea. Delapparentia turolensis Ruiz-Omeñaca, 2011 es el único taxón iguanodonte definido en el Barremiense de España. Está descrito a partir de un esqueleto postcraneal parcial descubierto en la década de 1950 próximo al pueblo de Galve (provincia de Teruel), dentro de la Formación Camarillas. Recientemente, se han recuperado nuevos restos del mismo individuo que se describen aquí. Además, tras examinar de primera mano el holotipo, se ha analizado la posición filogenética de este taxón por primera vez además de enmendar su diagnosis. Delapparentia turolensis es un iguanodonte basal de gran tamaño, que presenta una espina neural axial autapomórfica, al ser inusualmente alta, y una combinación única de caracteres postcraneales. La forma del ilion es diferente de la de otros iguanodontes basales y relaciona a Delapparentia con Barilium dawsoni del Valanginiense de Inglaterra, al compartir de forma exclusiva dos sinapomorfías. En nuestro análisis filogenético Delapparentia se sitúa en una politomía con Kukufeldia, Lanzhousaurus, Barilium y el clado equivalente a Iguanodontoide

    A new ornithopod dinosaur from the Santonian of Northern Patagonia (Rincón de los Sauces, Argentina)

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    In recent decades, the Argentinian ornithopod record – which includes eight species that have been described – has increased as a result of the discovery of diverse new bone remains from the Upper Cretaceous. The area near the town of Rincón de los Sauces (Neuquén Province) presents rich fossiliferous outcrops that have provided new ornithopod remains. These bones are from two units: the Plottier and Bajo de la Carpa formations. In the latter, several isolated postcranial bones and a partial articulated skeleton (MAU-Pv-CO-596) have been found. The holotype of Mahuidacursor lipanglef gen. et sp. nov. (MAU-Pv-CO-596) comes from the Cerro Overo site (Santonian, Upper Cretaceous). The skeleton preserves elements from the cervical and dorsal series, the pectoral girdle and the right forelimb. It corresponds to a medium-bodied ornithopod with a gracile general appearance. Histological analysis suggests that the specimen was a sexually mature but not fully grown individual. Some distinctive characters present in Mahuidacursor, such as the strongly bowed humeral shaft and the weakly developed deltopectoral crest, are shared with other South American basal ornithopods. A phylogenetic analysis including Mahuidacursor within a large ornithischian dataset was performed. The results show Mahuidacursor to be a basal ornithopod recovered within a polytomy along with Notohypsilophodon and the clade Elasmaria (Talenkauen + Macrogryphosaurus)

    A new primitive Neornithischian dinosaur from the Jurassic of Patagonia with gut contents

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    We describe a new species of an ornithischian dinosaur, Isaberrysaura mollensis gen. et sp. nov. The specimen, consisting in an almost complete skull and incomplete postcranium was collected from the marine-deltaic deposits of the Los Molles Formation (Toarcian-Bajocian), being the first reported dinosaur for this unit, one of the oldest from Neuquén Basin, and the first neornithischian dinosaur known from the Jurassic of South America. Despite showing a general stegosaurian appearance, the extensive phylogenetic analysis carried out depicts Isaberrysaura mollensis gen. et sp. nov. as a basal ornithopod, suggesting that both Thyreophora and neornithischians could have achieved significant convergent features. The specimen was preserved articulated and with some of its gut content place in the middle-posterior part of the thoracic cavity. Such stomach content was identified as seeds, most of them belonging to the Cycadales group. This finding reveals a possible and unexpected role of this ornithischian species as seed-dispersal agent

    HPM Approximations for Trajectories: From a Golf Ball Path to Mercury’s Orbit

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    In this work, we propose the approximated analytical solutions for two highly nonlinear problems using the homotopy perturbation method (HPM). We obtained approximations for a golf ball trajectory model and a Mercury orbit’s model. In addition, to enlarge the domain of convergence of the first case study, we apply the Laplace-Padé resummation method to the HPM series solution. For both case studies, we were able to obtain approximations in good agreement with numerical methods, depicting the basic nature of the trajectories of the phenomena

    Dendritic cell deficiencies persist seven months after SARS-CoV-2 infection

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    Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 infection induces an exacerbated inflammation driven by innate immunity components. Dendritic cells (DCs) play a key role in the defense against viral infections, for instance plasmacytoid DCs (pDCs), have the capacity to produce vast amounts of interferon-alpha (IFN-α). In COVID-19 there is a deficit in DC numbers and IFN-α production, which has been associated with disease severity. In this work, we described that in addition to the DC deficiency, several DC activation and homing markers were altered in acute COVID-19 patients, which were associated with multiple inflammatory markers. Remarkably, previously hospitalized and nonhospitalized patients remained with decreased numbers of CD1c+ myeloid DCs and pDCs seven months after SARS-CoV-2 infection. Moreover, the expression of DC markers such as CD86 and CD4 were only restored in previously nonhospitalized patients, while no restoration of integrin β7 and indoleamine 2,3-dyoxigenase (IDO) levels were observed. These findings contribute to a better understanding of the immunological sequelae of COVID-19
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