García Osuna HT, A Benavides Mendoza, L Escobedo Bocardo, JA Villarreal Quintanilla, E Cornejo Oviedo

Phyton-International Journal of Experimental Botany, Vol.80, pp. 175-179, 2011, DOI:10.32604/phyton.2011.80.175

Abstract Turbinicarpus valdezianus is a species under special protection, according to the current law NOM-059-ECOL-2010. It spreads preferably through shoot proliferation in vitro. A common problem associated with the propagation of this species by tissue culture is the hyperhydricity or excess of water accumulation in the tissues of shoots explants. The literature on this topic indicates that such response is related with oxidative stress. Because of this, the effects of inhibitors of the gibberellins [paclobutrazol (PBZ) and calcium prohexadione (PCa)] and salicylic (SA) and benzoic acids (BA) were tested to diminish the hiperhydrycity of the sprouts, which was… More >

Pérez Castañeda LM, MA Cruz Hernández, A Mendoza Herrera

Phyton-International Journal of Experimental Botany, Vol.80, pp. 27-34, 2011, DOI:10.32604/phyton.2011.80.027

Abstract Various studies have shown the symbiotic association of Azospirillum brasilense with different grasses of nutritional importance. A high variability among the isolated strains has been observed. This is consistent with the genetic diversity that Azospirillum has shown in sugarcane isolates. However, if this is also the case in maize and sorghum isolates is unknown. In addition, it has also been reported that most of the isolates come from tropical regions where water is not limiting for maize and sorghum production. We analyzed the genetic variability of Azospirillum brasilense isolates obtained from arid zones of Northeast Mexico in maize… More >

GISELE ORLANDI INTROÍNI¹, FERNANDA MARTINS MAESTER¹, FOSCA Pedini PEREIRA LEITE² AND SHIRLEI MARIA RECCO-PIMENTEL¹

BIOCELL, Vol.34, No.3, pp. 103-112, 2010, DOI:10.32604/biocell.2010.34.103

Abstract Ultrastructural analyses of bivalve spermatozoa are relevant in studies that aim to identify taxonomic traits for the purposes of discriminating species and conducting phylogenetic studies. In the present work, spermatozoa of mussel specimens of the genus Mytella, collected from two populations living in distinct habitats, were examined by electron microscopy. The objective was to identify sperm ultrastructural taxonomic traits that could be used to differentiate Mytella species. The specimens were from populations that live in intertidal zones on the southeast coast of Brazil, either buried in muddy-sand sediment or anchored to rocky substrates. The acrosomal vesicle… More >

SILVIA VILA, ANA GONZALEZ, HEBE REY AND LUIS MROGINSKI*

BIOCELL, Vol.34, No.1, pp. 7-14, 2010, DOI:10.32604/biocell.2010.34.007

Abstract Embryogenic cultures were initiated from immature Melia azedarach (Meliaceae) zigotic embryos. Explants were induced on Murashige and Skoog (1962) medium with 4.54 μM thidiazuron or 0.45 μM dichlorophenoxyacetic acid. After 6 weeks of culture on induction medium, somatic embryos were categorized in four morphological classes based on the presence of single or fused embryos and if they remained united or not to the original explant; that were evaluated histologically. The somatic embryos of every category were transferred, in groups or individually, on a 1/4 MS medium. Bipolar embryos, the more typically normal ones, had well defined More >

MARÍA LAURA FONTANA, LUIS AMADO MROGINSKI, HEBE YOLANDA REY*

BIOCELL, Vol.33, No.3, pp. 179-186, 2009, DOI:10.32604/biocell.2009.33.179

Abstract With the aim of developing an efficient plant regeneration protocol, leaflet explants of three accessions of Arachis villosa Benth. (S2866, S2867 and L97) were cultured on basic Murashige and Skoog medium supplemented with different combinations of plant growth regulators: α-naphthalenacetic acid, indole-3-butyric acid, 6-benzylaminopurine, kinetin and thidiazuron. The accession L97 was the only one able to differentiate buds through indirect organogenesis. The most suitable combination for bud regeneration was the basic medium added with 13.62 μM thidiazuron and 4.44 μM 6-benzylaminopurine. These results show the important role of the genotype in morphogenetic responses and the organogenetic effect of More >

TARSILA MARIA DA SILVA MORAES¹, CLAUDIA FRANCA BARROS², SEBASTIÃO JOSÉ DA SILVA NETO³, VALDIRENE MOREIRA GOMES⁴, MAURA DA CUNHA^1*

BIOCELL, Vol.33, No.3, pp. 155-165, 2009, DOI:10.32604/biocell.2009.33.155

Abstract Simira is a predominantly woody Neotropical genus comprising 41 taxa, 16 of which occur in Brazil and eight of them in the southeastern region of Brazil. Leaf blades of Simira eliezeriana Peixoto, S. glaziovii (K. Schum.) Steyerm., S. grazielae Peixoto, S. pikia (K. Schum.) Steyerm., S. rubra (Mart.) Steyerm., S. sampaioana (Standl.) Steyerm. were collected in the southeastern region of Brazil and fixed according to usual methods for light and electron microscopy. The leaf blades show typical characteristics of the Rubiaceae family as dorsiventral mesophyll and paracytic stomata. The presence of two bundle sheaths that extend to the upper epidermal layer, More >

AnteBilić¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.1, pp. 13-14, 2009, DOI:10.3970/icces.2009.013.013

Abstract Using several popular first-principles packages for materials modeling the nature of the cubic lattice of barium zirconate has been investigated. The evaluated vibrational spectra typically exhibit an extended and prominent dynamical instability. The instability manifests through imaginary frequency optical modes along the whole R-M edge of the Brillouin zone. The experimentally observed simple cubic structure is found to be dynamically unstable against an antiferro-distortive transformation. The computations predict an orthorhombic crystal structure of the material, only slightly distorted from the cubic lattice, with an eight times larger unit cell and alternate ZrO₆ octahedra slightly rotated in More >

ELEONIDAS MOURA LIMA^1,2, MARIANA FERREIRA LEAL³, MARÍLIA DE ARRUDA CARDOSO SMITH³, ROMMEL RODRÍGUEZ BURBANO⁴, PAULO PIMENTEL DE ASSUMPÇÃO⁵, MARIA JOSE BELLO⁶, JUAN ANTONIO REY⁶, FRANCINALDO FERREIRA DE LIMA⁷, CACILDA CASARTELLI²

BIOCELL, Vol.32, No.3, pp. 237-243, 2008, DOI:10.32604/biocell.2008.32.237

Abstract Gastric cancer is one of the most common malignancies. DNA methylation is implicated in DNA mismatch repair genes deficiency. In the present study, we evaluated the methylation status of MLH1, MSH2, MSH6 and PMS2 in 20 diffuse- and 26 intestinal-type gastric cancer samples and 20 normal gastric mucosal of gastric cancer patients from Northern Brazil. We found that none of the nonneoplastic samples showed methylation of any gene promoter and 50% of gastric cancer samples showed at least one methylated gene promoter. Methylation frequencies of MLH1, MSH2, MSH6 and PMS2 promoter were 21.74%, 17.39%, 0% and 28.26% respectively… More >

ADELINA FERREIRA¹, MAHMOUD MEHANNA^1,2, CYNTHIA P. A. PRADO³

BIOCELL, Vol.32, No.2, pp. 185-194, 2008, DOI:10.32604/biocell.2008.32.185

Abstract The spermatogenesis of Pseudis limellum, from the Southern Pantanal, Brazil, was studied from July 1995 to May 1996, through histological sections of the testis. The cells could be differentiated as: primary spermatogonia, large cells, generally with bilobed nucleus; secondary spermatogonia, smaller cells, with darker cytoplasm, chromatin of radial form; primary and secondary spermatocytes, differentiated according to the different stages of the nucleus during the successive cells divisions. Furthermore, we observed cells in process of morphologic differentiation: rounded spermatids much smaller, with nucleus containing chromatin in compacting process and cytoplasm reduction; elongated spermatids, generally parallel organized in… More >

Tienfuan Kerh^1,2, J.S. Lai¹, D. Gunaratnam², R. Saunders²

CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.1, pp. 1-12, 2008, DOI:10.3970/cmes.2008.026.001

Abstract Taiwan frequently suffers from strong ground motion, and the current building code is essentially based on two seismic zones, A and B. The design value of horizontal acceleration for zone A is 0.33g, and the value for zone B is 0.23g. To check the suitability of these values, a series of actual earthquake records are considered for evaluating peak ground acceleration (PGA) for each of the zones by using neural network models. The input parameters are magnitude, epicenter distance, and focal depth for each of the checking stations, and the peak ground acceleration is calculated… More >