Spline functions and total positivity

Sin resume

Cubic pencils of lines and bivariate interpolation

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

Quasi-LDU factorization of nonsingular totally nonpositive matrices

Let A = (a(ij)) is an element of R-nxn be a nonsingular totally nonpositive matrix. In this paper we describe some properties of these matrices when a(11) = 0 and obtain a characterization in terms of the quasi-LDU factorization of A, where L is a block lower triangular matrix, D is a diagonal matrix and U is a unit upper triangular matrix. (c) 2012 Elsevier Inc. All rights reserved.The authors are very grateful to the referees for their helpful suggestions. This research was supported by the Spanish DGI Grant MTM2010-18228 and the Programa de Apoyo a la Investigacion y Desarrollo (PAID-06-10) of the Universitat Politecnica de Valencia.Cantó Colomina, R.; Ricarte Benedito, B.; Urbano Salvador, AM. (2013). Quasi-LDU factorization of nonsingular totally nonpositive matrices. Linear Algebra and its Applications. 439(4):836-851. https://doi.org/10.1016/j.laa.2012.06.010S836851439

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

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

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

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

Delapparentia turolensis Ruiz-Omeñaca, 2011 is the only iguanodont taxon erected in the Barremian of Spain. It is described on the basis of 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 Iguanodontoidea

Estimating evaporation from a wet grassland

International audienceWet grasslands are being restored across the UK and Europe to reinstate their high biodiversity following over 50 years of drainage and conversion to arable agriculture. The water balance of many wet grasslands is dominated by precipitation and evaporation and it is essential to quantify evaporation rates to understand the hydrological functioning of wetlands and the implications for water resources in catchments where wetlands are being restored. This paper considers data from direct measurements of evaporation from the Pevensey Levels wet grassland using the eddy correlation method. Equations are derived to predict actual evaporation using meteorological data on the site or from standard meteorological station observations. It was found that evaporation could be estimated reliably from meteorological variables, such as wind speed, temperature and humidity and by water availability. It was also found that when water availability is high, evaporation is high and may exceed reference evaporation values, raising questions over the deployment of the two-step Penman-Monteith model unless reliable crop coefficients and relative evaporation figures can be determined

Obatoclax and Paclitaxel Synergistically Induce Apoptosis and Overcome Paclitaxel Resistance in Urothelial Cancer Cells

Paclitaxel is a treatment option for advanced or metastatic bladder cancer after the failure of first-line cisplatin and gemcitabine, although resistance limits its clinical benefits. Mcl-1 is an anti-apoptotic protein that promotes resistance to paclitaxel in different tumors. Obatoclax, a BH3 mimetic of the Bcl-2 family of proteins, antagonizes Mcl-1 and hence may reverse paclitaxel resistance in Mcl-1-overexpressing tumors. In this study, paclitaxel-sensitive 5637 and -resistant HT1197 bladder cancer cells were treated with paclitaxel, obatoclax, or combinations of both. Apoptosis, cell cycle, and autophagy were measured by Western blot, flow cytometry, and fluorescence microscopy. Moreover, Mcl-1 expression was analyzed by immunohistochemistry in bladder carcinoma tissues. Our results confirmed that paclitaxel alone induced Mcl-1 downregulation and apoptosis in 5637, but not in HT1197 cells; however, combinations of obatoclax and paclitaxel sensitized HT1197 cells to the treatment. In obatoclax-treated 5637 and obatoclax + paclitaxel-treated HT1197 cells, the blockade of the autophagic flux correlated with apoptosis and was associated with caspase-dependent cleavage of beclin-1. Obatoclax alone delayed the cell cycle in 5637, but not in HT1197 cells, whereas combinations of both retarded the cell cycle and reduced mitotic slippage. In conclusion, obatoclax sensitizes HT1197 cells to paclitaxel-induced apoptosis through the blockade of the autophagic flux and effects on the cell cycle. Furthermore, Mcl-1 is overexpressed in many invasive bladder carcinomas, and it is related to tumor progression, so Mcl-1 expression may be of predictive value in bladder cancer.España, Sistema Público Andaluz Biobanco y ISCIII-Red de Biobancos PT17/0015/004