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  • Open Access

    ARTICLE

    Segregation of patches by patterns of soil attributes in a native grassland in central Argentina

    Villamil MB1, NM Amiotti2, N Peinemann3

    Phyton-International Journal of Experimental Botany, Vol.80, pp. 193-201, 2011, DOI:10.32604/phyton.2011.80.193

    Abstract Demand for greater cattle production at the El Caldenal area in central Argentina has resulted in overgrazing in a patchy grassland structure. Patches are clearly identified on the basis of dominant plant species resulting from their grazing history. Our primary objective was to examine the influence of individual plants at each patch on the local multivariate pattern of soil nutrients, assessing the magnitude of the association between the concentration of nutrients in the plant and its underlying soil. Canonical discriminant analysis highlighted the important role of soil organic matter, available P, and Zn content of More >

  • Open Access

    ARTICLE

    Hyperhydricity control of in vitro shoots of Turbinicarpus valdezianus (Möller) GL & F

    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 >

  • Open Access

    ARTICLE

    Genetic variability of non-typical Azospirillum brasilense isolates by PCR-RFLP analysis of 16S ribosomal DNA

    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 >

  • Open Access

    ARTICLE

    Tissue-specific expression of IL-15RA alternative splicing transcripts and its regulation by DNA methylation

    Susana N. Diniz1,2, Karen P. T. Pendeloski1, Andrey Morgun1,3, Iouri Chepelev4, Maria Gerbase-DeLima1,*, Natalia Shulzhenko1,3,*

    European Cytokine Network, Vol.21, No.4, pp. 308-318, 2010, DOI:10.1684/ecn.2010.0218

    Abstract The human IL-15RA gene encoding the alpha chain of the IL-15 receptor is expressed in a varietyof immune and non-immune cell types from different tissues, and generates multiple splicing events of func-tional importance. We aimed to evaluate expression of IL-15RA transcripts generated by alternative usage oftranscription start site (Var1 and Var2) and by deletion of exon 3 (Del3), exon 2 (Del2), or both (Del2,3) in dif-ferent human tissues. Since a CpG island was found near to the IL-15RA gene transcription start site, we alsoinvestigated the role of DNA methylation on the expression of IL-15RA full-length… More >

  • Open Access

    ARTICLE

    Effect of omeprazole on the concentration of interleukin-6 and transforming growth factor-β1 in patients receiving dual antiplatelet therapy after percutaneous coronary intervention

    Bartosz Hudzik1, Janusz Szkodzinski1, Aleksander Danikiewicz2, Krzysztof Wilczek1, Wojciech Romanowski2, Andrzej Lekston1, Lech Polonski1, Barbara Zubelewicz-Szkodzinska2

    European Cytokine Network, Vol.21, No.4, pp. 257-263, 2010, DOI:10.1684/ecn.2010.0213

    Abstract Background. Dual antiplatelet therapy (aspirin plus clopidogrel) is recommended in patients undergoing percutaneous coronary intervention (PCI). Treatment with proton pump inhibitors (PPIs) decreases bleeding rate. Alarming reports have been made that PPIs may decrease the antiplatelet activity of clopidogrel. We sought to determine whether levels of interleukin-6 (IL-6) and transforming growth factor-β1 (TGF-β1) might help distinguish individuals at risk for adverse events. Methods. Thirty-eight patients on aspirin and clopidogrel were enrolled and divided into two groups: group 1 [patients receiving omeprazole (n = 18)] and group 2 [patients not receiving omeprazole (n = 20)]. Patients… More >

  • Open Access

    ARTICLE

    Sperm ultrastructure of Mytella (Bivalvia) populations from distinct habitats along the northern coast of São Paulo State, Brazil

    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 >

  • Open Access

    ARTICLE

    Effect of morphological heterogeneity of somatic embryos of Melia azedarach on conversion into plants

    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 >

  • Open Access

    ARTICLE

    Organogenesis and plant regeneration of Arachis villosa Benth. (Leguminosae) through leaf culture

    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 >

  • Open Access

    ARTICLE

    Leaf blade anatomy and ultrastructure of six Simira species (Rubiaceae) from the Atlantic Rain Forest, Brazil

    TARSILA MARIA DA SILVA MORAES1, CLAUDIA FRANCA BARROS2, SEBASTIÃO JOSÉ DA SILVA NETO3, VALDIRENE MOREIRA GOMES4, MAURA DA CUNHA1*

    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 >

  • Open Access

    ABSTRACT

    The structure of BaZrO$_3$: a comparative first-principles study

    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 >

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