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| Registros recuperados: 992 | |
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| VERA,MARÍA INÉS; MOLINA,ALFREDO; PINTO,RODRIGO; REYES,MAURICIO; ÁLVAREZ,MARCO; KRAUSKOPF,ERWIN; QUEZADA,CLAUDIA; TORRES,JORGE; KRAUSKOPF,MANUEL. |
| The seasonal adaptation of the teleost Cyprinus carpio to the cyclical changes of its habitat demands physiological compensatory responses. The process involves profound nucleolar adjustments and remarkable changes in rRNA synthesis, which affects ribosomal biosynthesis. In this context, we have demonstrated that the synthesis of several proteins involved in ribosomal biogenesis as protein kinase CK2, ribosomal protein L41 and nucleolin, as well as U3 snoRNP, are differentially regulated in summer-acclimatized carp compared to the cold-season adapted fish. To understand the mechanisms involved in the seasonal regulation of rRNA gene transcription, we have been studying the carp rDNA cistron structure. Because the cis-elements that regulate the expression... |
| Tipo: Journal article |
Palavras-chave: Ribosomal gene; RRNA; RDNA; Fish; Carp. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000200014 |
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| CIFUENTES,ANA S; GONZÁLEZ,MARIELA A; VARGAS,SILVIA; HOENEISEN,MARITZA; GONZÁLEZ,NELSON. |
| The microalga Haematococcus pluvialis Flotow is one of the natural sources of astaxanthin, a pigment widely used in salmon feed. This study was made to discover optimal conditions for biomass and astaxanthin production in H. pluvialis from Steptoe, Nevada (USA), cultured in batch mode. Growth was carried out under autotrophic (with NaNO3, NH4Cl and urea) and mixotrophic conditions (with 4, 8, 12 mM sodium acetate) under two photon flux densities (PFD) (35 and 85 µmol m-2 s-1). The carotenogenesis was induced by 1) addition of NaCl (0.2 and 0.8 %), 2) N-deprivation and 3) high PFD (150 µmol m-2 s-1). Total carotenoids were estimated by spectrophotometry and total astaxanthin by HPLC. Ammonium chloride was the best N-source for growth (k=0.7 div day-1,... |
| Tipo: Journal article |
Palavras-chave: Astaxanthin; Carotenogenesis; Growth; Haematococcus pluvialis. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000300006 |
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| FERNÁNDEZ,VIRGINIA; MASSA,LAURA; QUIÑONES,LUIS; SIMON-GIAVAROTTI,KARIN A; GIAVAROTTI,LEANDRO; D'ALMEIDA,VÂNIA; AZZALIS,LIGIA A; JUNQUEIRA,VIRGINIA BC; VIDELA,LUIS A. |
| Liver microsomal cytochrome P4502E1-dependent p-nitrophenol (PNP) hydroxylation and expression of cytochrome P4502E1 were studied in rats subjected to g-hexachlorocyclohexane (HCCH) or L-3,3,,5-triiodothyronine (T3) administration as a possible mechanism contributing to superoxide radical (O2.-) generation. HCCH treatment (a single dose of 40 mg/kg body wt) produced a 43% increase in the content of total cytochrome P450, whereas T3 (daily doses of 0.1 mg/kg body wt for two consecutive days) led to a 37% decrease. NADPH-dependent O2.- generation was elevated by HCCH and T3, expressed as either per mg of protein or per nmol of cytochrome P450, with a 135% enhancement in the O2.- production/superoxide dismutase (SOD) activity ratios being observed in both... |
| Tipo: Journal article |
Palavras-chave: G-Hexachlorocyclohexane L-3; 3'; 5-Triiodothyronine Superoxide radical Cytochrome P4502E1 Rat liver. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000300007 |
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| MAASS,ALEJANDRO; MARTÍNEZ,SERVET. |
| In this paper we review some recent results on the evolution of probability measures under cellular automata acting on a fullshift. In particular we discuss the crucial role of the attractiveness of maximal measures. We enlarge the context of the results of a previous study of topological Markov chains that are Abelian groups; the shift map is an automorphism of this group. This is carried out by studying the dynamics of Markov measures by a particular additive cellular automata. Many of these topics were within the focus of Francisco Varela's mathematical interests. |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000100010 |
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| PELAYO,HELVIA R; PINCHEIRA,JUANA; GIMÉNEZ-ABIÁN,JUAN F; CLARKE,DUNCAN J; DE LA TORRE,CONSUELO. |
| Allium cepa L. meristems were used as a plant model to study the p53-independent control of S and G2 phases by checkpoint pathways, in eukaryotic cells. Checkpoint blocks were induced at early and mid S by hydroxyurea. After their spontaneous override, cells became accumulated in G2-prophase, giving rise later on to a delayed mitotic wave. Cell growth was maintained during the checkpoint blocks, as the delayed mitoses were larger in size than the control ones. Under continuous hydroxyurea treatment, the delayed mitotic was formed by two subpopulations: normal mitoses corresponding to cells having properly recovered from the checkpoint block, and abnormal ones resulting from checkpoint adaptation. These latter cells displayed broken chromatids as they had... |
| Tipo: Journal article |
Palavras-chave: Checkpoint adaptation; Hydroxyurea; S and G2 checkpoints; P53-independent checkpoints; Allium cepa L. meristems. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000300009 |
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| MIQUEL,ALVARO; MÜLLER,ILSE; FERRER,PABLO; VALENZUELA,PABLO D. T.; BURZIO,LUIS O. |
| We have used the expression library immunization technology to study the protection of Coho salmon Oncorhynchus kisutch to the infection with Piscirickettsia salmonis. Purified DNA from this bacterium was sonicated and the fragments were cloned in the expression vector pCMV-Bios. Two libraries were obtained containing 22,000 and 28,000 colonies and corresponding to approximately 8 and 10 times the genome of the pathogen, respectively. On average, the size of the inserts ranged between 300 and 1,000 bp. The plasmid DNA isolated from one of these libraries was purified and 20 µg were injected intramuscularly into 60 fish followed by a second dose of 10 µg applied 40 days later. As control, fish were injected with the same amount of DNA of the vector... |
| Tipo: Journal article |
Palavras-chave: Piscirickettsia salmonis; Genetic vaccine; Expression library immunization. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000300004 |
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| WILHELM,VIVIAN; VILLEGAS,JAIME; MIQUEL,ÁLVARO; ENGEL,ESTEBAN; BERNALES,SEBASTIÁN; VALENZUELA,PABLO D.T.; BURZIO,LUIS O.. |
| The complete sequence of the mitochondrial genome of Chinook salmon, Oncorhynchus tshawytscha, has been determined. The circular genome consisting of 16,644 base pairs encodes thirteen proteins, the 12S and 16S ribosomal RNAs, and 22 transfer RNAs. These genes are ordered in the same way as most other vertebrates. The nucleotide and amino acid sequences of the ribosomal RNAs and the thirteen protein-coding genes were compared with those of other salmonids such as Oncorhynchus mykiss, Salmo salar, Salvelinus fontinalis, Salvelinus alpinus and Coregonus lavaretus. The sequence features of the control region (D-loop), the origin of L-strand replication and a putative peptide codified by the 16S mitochondrial RNA are described and discussed. |
| Tipo: Journal article |
Palavras-chave: Salmonids; Mitochondria; Genome; Peptides; 16S rRNA. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000200012 |
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| Registros recuperados: 992 | |
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