Salvador A Arias

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In the present study plasma samples from 15 systemic lupus erythematosus (SLE) patients and 16 healthy controls of initially unknown haptoglobin (Hp) phenotype were separated by 2-DE, and tryptic digests of the excised Hpalpha polypeptide chain spots were analyzed by MALDI-TOF-MS. Selected tryptic peptides were sequenced by nano-(n)ESI-IT MS/MS. The six(More)
The morphology and anatomy of the Cephalocereus columna-trajani flowering region was described and compared with data on other species. The vegetative and reproductive regions were described in detail. The results showed that after the flowering region is differentiated, morphological changes take place which are correlated with anatomical changes. The(More)
Basic anatomical features of Cactaceae have been studied since the sixteenth century. This anatomical research has focused on selected features related to different external forms or on stem photosynthetic metabolism. Anatomical stem features, however, have rarely been taken into consideration in systematic studies. Recent work has focused on the subfamily(More)
A high proportion of plant species is predicted to be threatened with extinction in the near future. However, the threat status of only a small number has been evaluated compared with key animal groups, rendering the magnitude and nature of the risks plants face unclear. Here we report the results of a global species assessment for the largest plant taxon(More)
The phylogenetic relationships of Peniocereus (Cactaceae) species were studied using parsimony analyses of DNA sequence data. The plastid rpl16 and trnL-F regions were sequenced for 98 taxa including 17 species of Peniocereus, representatives from all genera of tribe Pachycereeae, four genera of tribe Hylocereeae, as well as from three additional outgroup(More)
Echinocereus sección Triglochidiati ha sido aceptada en los más recientes tratamientos taxonómicos del género, sin embargo el número de especies que incluye ha variado entre una y 14. El presente trabajo tiene como objetivo delimitar el número de especies de la sección Triglochidiati para México a través de análisis multivariados, así como identificar los(More)
El géneroPachycereus incluye 13 especies de acuerdo con las clasificaciones más recientes, y se distribuye en Guatemala, México y SW de los Estados Unidos, Se presenta un análisis filogenético con el propósito de fundamentar la monofilia del género, respecto a los otros géneros de la subtribu Pachycereinae. Se creó una matriz utilizando 44 caracteres(More)
The in situ dry matter (DM) disappearance of corn silages in two maturity stages (milk grain and half milk line) of known in vivo and in vitro digestibility was determined, with the main purpose of comparing digestibility values with the ruminal disappearance at 24 and 48h of incubation. A secondary goal was the description of their ruminal digestion(More)
BACKGROUND AND AIMS In Cactaceae, the areole is the organ that forms the leaves, spines and buds. Apparently, the genus Echinocereus develops enclosed buds that break through the epidermis of the stem adjacent to the areole; this trait most likely represents a synapomorphy of Echinocereus. The development of the areole is investigated here in order to(More)
(2006) A sensitivity analysis for choosing reliability functions to select cladograms. Zoologica scripta, 00, 000-000. Different methods to select among reliability functions used in cladistics (linear parsimony and implied weights) are proposed and explored under a sensitivity analysis framework. The proposed methods are character, taxon and mixed(More)