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| Registros recuperados: 10.260 | |
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| Grigera,Dora; Úbeda,Carmen. |
| Se efectuó una revisión de los trabajos realizados entre 1960 y 2001 sobre categorizaciones y establecimiento de prioridades de conservación de vertebrados de Argentina. En cinco de los trabajos inventariados no se explicita cómo se arribó a los resultados, siete son compilaciones, dos se basan en la opinión de especialistas y en 46 se utilizan diversos métodos. Suman 11 los métodos creados por autores argentinos y basados en criterios explícitos. Los criterios más utilizados son el tamaño de las poblaciones y los relativos a características biológicas. Entre los métodos analizados hay disparidad en el tipo y calidad de información que requieren para su aplicación. Con una excepción, la evaluación o ponderación de los criterios se lleva a cabo en una sola... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Conservación; Vertebrados; Prioridades; Métodos de evaluación. |
| Ano: 2002 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2002000200010 |
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| Quirós,Rolando; Rennella,Armando M; Boveri,María A; Rosso,Juan J; Sosnovsky,Alejandro. |
| La estructura y el funcionamiento de las lagunas pampeanas pueden explicarse por su geomorfología, régimen climático, drenajes ubicados en suelos naturalmente ricos en nutrientes y por las modificaciones humanas en el uso de la tierra y el agua. Es posible caracterizarlas sintéticamente como lagos de llanura, someros, polimícticos, eutróficos o hipertróficos, y con tiempo de permanencia del agua y salinidad altamente variables. Estas características explicarían la elevada biomasa de sus comunidades bióticas. Un análisis sincrónico, durante el pico de la estación de crecimiento, nos permitió discriminar tres tipos dentro de las grandes lagunas de carácter permanente: lagunas con biomasa del fitoplancton relativamente baja y abundante desarrollo de las... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lagos someros; Región pampeana; Ecosistemas acuáticos; Estructura y funcionamiento. |
| Ano: 2002 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2002000200011 |
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| Sagadin,Ileana M; Gorla,David E. |
| En el centro de la provincia de Córdoba las larvas de Lepidoptera constituyen plagas de gran importancia debido a las pérdidas de rendimiento que ocasionan en los cultivos de maíz y soja. En este trabajo se compara la eficiencia de captura de adultos de Lepidoptera en dos trampas de luz, una con lámpara de vapor de mercurio tipo HPL de 125 W y otra con un tubo de luz negra de 15 W. La recolección de adultos se realizó con una frecuencia de 1-3 veces por semana, desde diciembre 1997 hasta diciembre 2000. La comparación de la eficiencia de las trampas para cada especie se realizó estimando la pendiente de la relación entre las capturas semanales obtenidas por cada tipo de trampa. En general, se observó mayor eficiencia de captura en las trampas de luz de... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Noctuidae; Trampas de luz; Plagas de maíz; Plagas de soja. |
| Ano: 2002 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2002000200003 |
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| Mendoza,Rodolfo E; Goldmann,Valeria; Rivas,Juan; Escudero,Viviana; Pagani,Eduardo; Collantes,Marta; Marbán,Liliana. |
| El sobrepastoreo ovino en pastizales de suelos ácidos de Tierra del Fuego ha determinado una disminución de la cobertura de gramíneas de interés forrajero y un aumento de la cobertura de un arbusto postrado poco apetecible (murtilla, Empetrum rubrum). Se seleccionaron suelos sometidos a distinta modalidad de pastoreo que tenían características y vegetación particulares. Se midió la cantidad total y la diversidad de esporas de hongos micorrízicos arbusculares en los cuatro suelos y en la rizósfera de tres de las gramíneas más frecuentes (Festuca gracillima, Deschampsia flexuosa y Poa rigidifolia) en los pastizales de la estepa fueguina. En el suelo rizosférico se determinó la cantidad y la diversidad de esporas de hongos micorrízicos arbusculares, y en las... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pastizales; Micorrizas arbusculares; Esporas; Colonización de raíz; Planta hospedante; Propiedades del suelo; Pastoreo. |
| Ano: 2002 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2002000200004 |
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| Bobadilla,Roberto; Varela,Cristián; Céspedes,Ricardo; González,Bernardo. |
| Chloroaromatic pollutants from bleached Kraft pulp mill effluents (BKME) are difficult to degrade, because bacterial strains present in BKME aerobic treatments, only partially degrade these compounds, accumulating the corresponding chlorocatechol intermediates. To improve the catabolic performance of chlorocatechol-accumulating strains, we introduced, by chromosomal insertion, the tfdI CDEF gene cluster from Ralstonia eutropha JMP134 (pJP4). This gene cluster allows dechlorination and channelling of chlorocatechols into the intermediate metabolism. Two bacterial strains, R. eutropha JMP222 and Pseudomonas putida KT2442, able to produce chlorocatechols from 3-chlorobenzoate (3-CB) were used. Acinetobacter lwoffii RB2 isolated from BKME by its ability to... |
| Tipo: Journal article |
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| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582002000200011 |
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| Vignani,Rita; Scali,Monica; Masi,Elisa; Cresti,Mauro. |
| Microsatellite polymorphism analysis on 25 different "Sangiovese" accessions was carried out at eight microsatellite loci (VVS2, VVS4, VVS29, VVMD3, VVMD6, VVMD7, VVMD17 and VVMD21). In order to evaluate variability within the "Sangiovese" variety and to confirm variety identification, genotype analysis, allele distribution and pedigree information were processed with a DNA-automated sequencer running AlleleLinks software. DNA typing revealed three cases of genetic dissimilarity compared to registered "Sangiovese" clones and the divergent accessions thought to be different clones of the same variety. The divergent accessions were different from "Sangiovese" at four microsatellite loci (VVS2, VVS4, VVMD7 and VVMD21). An innovative non-radioactive... |
| Tipo: Journal article |
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| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582002000100007 |
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| Mahalakshmi,Viswanathan; Aparna,P.; Ramadevi,S.; Ortiz,Rodomiro. |
| Simple sequence repeats (SSR) or micro-satellites are becoming standard DNA markers for plant genome analysis and are being used as markers in marker assisted breeding. De novo generation of micro-satellite markers through laboratory-based screening of SSR-enriched genomic libraries is highly time consuming and expensive. An alternative is to screen the public databases of related model species where abundant sequence data is already available. All the genomic sequences of Medicago from the public domain database were searched and analysed of di, tri, and tetra nucleotide repeats. Of the total of about 156,000 sequences which were searched, 7325 sequences were found to contain repeat motif and may yield SSR which will yield product sizes of around 200 bp.... |
| Tipo: Journal article |
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| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582002000300007 |
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| Lawrence,Paulraj K.; Koundal,Kripa Ram. |
| Plant proteinase inhibitors (PIs) have been well established to play a potent defensive role against predators and pathogens. Although diverse endogenous functions for these proteins has been proposed, ranging from regulators of endogenous proteinases to act as storage proteins, evidence for many of these roles is partial, or confined to isolated examples. On the other hand, many PIs have been shown to act as defensive compounds against pests by direct assay or by expression in transgenic crop plants, and a body of evidence for their role in plant defense has been accumulated consistently. The role and mechanism of action for most of these inhibitors are being studied in detail and their respective genes isolated. These genes have been used for the... |
| Tipo: Journal article |
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| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582002000100014 |
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| Sun,Chuan-Bao; Kong,Qiu-Lian; Xu,Wen-Si. |
| The vgb and bleomycin resistance genes could be efficiently transferred into the filamentous fungus Penicillium chrysogenum under help of T-DNA of Agrobacterium tumefaciens LBA4404 and the transferred genes were integrated at a chromosomal locus of P. chrysogenum. Transformation using A. tumefaciens LBA4404 could be enhanced in the presence of acetosyringone (AS) when being carried out in the conidiaand mycelium. The efficiencies of transformation could be improved up to 10 folds compared with conventional techniques for transformation of P. chrysogenum protoplasts. |
| Tipo: Journal article |
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| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582002000100009 |
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| Johnson,Elizabeth; Herd,Susanna; Tisdall,Judith. |
| Generic skills are skills that are common to all graduates rather than specific for a particular field of study. They include communication and problem-solving skills and the ability to work successfully in teams. To produce graduates with these skills, university courses must include exercises that encourage development of these skills and assessment procedures which reward achievement in these areas. This paper describes three simple exercises designed to develop generic skills that can easily be incorporated into existing courses. |
| Tipo: Journal article |
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| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582002000200004 |
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| Bustamante,Pedro I.; Bowra,Steve. |
| In the global market, the emergence of new technologies are representing opportunities and challenges to both industry and the public sector of the Latin American Countries (LAC). Some of these technologies have far reaching implications for a large number of industrial sectors, creating wealth and employment, resulting in an increased competitiveness of the developed economies around the world. Modern biotechnology is one of these key emerging technologies which LAC must harness successfully to sustain economic growth and competitiveness. The ability to commercially exploit research in this area is also of prime importance. Developed countries have made important progress in recent years, with a strong leadership of USA in this sector. Unless substantial... |
| Tipo: Journal article |
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| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582002000300001 |
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| Telles Benatti,Cláudia; Granhen Tavares,Célia Regina; Dias Filho,Benedito Prado; Ribeiro Moitinho,Maria da Luz. |
| This study was designed to evaluate the performance of a slow rate anaerobic digester in treating secondary sewage sludge received from one local municipal wastewater treatment plant. The digester was fed by secondary sewage sludge without any previous thickening. A series of three independent batch experiments was investigated at an operation time of 60 days. The total solids (TS) in the influent sludge contained a percentage of organic matter of 59, 63 and 54%, a concentration of volatile suspended solids (VSS) of 23.7, 29.2 and 27.8 g L-1 and a chemical oxygen demand (COD) of 51.8, 32.9 and 65.7 g L-1 for the three experiments, respectively. The operation of anaerobic digestion was stable, with no noticeable scum or foaming problems. The COD reduction... |
| Tipo: Journal article |
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| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582002000300005 |
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| Bernal,Giuliano; Illanes,Andrés; Ciampi,Luigi. |
| The use of microorganisms for biological purposes has become an effective alternative to control plant pathogens. There are many examples of formulations using bacterial or fungal strains with biocontrol applications. Among them, members of the genus Bacillus are well known antibiotic producers. However, the increased capacity of antibiotic production obtained by direct mutagenesis of wild strains, has seldom been reported in the open literature. This research refers to the mutation of the A47 Bacillus strain, a plant pathogen antagonist, in order to obtain an improved strain with enhanced capacity to synthesize metabolites with antibiotic activity. The mutant strain M40 was obtained using the mutagenic agent acridine orange. The mutant strain showed a... |
| Tipo: Journal article |
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| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582002000100008 |
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| Xia,Yulu; Stinner,Roland E.; Chu,Ping-Chu. |
| The Internet has fundamentally changed the way we conduct our business. Even 10 years ago or so, it was not possible to order a book or access a sequence database in another continent using the computer in our office. All these become possible due to the progress in information technology. It is especially important for biologists to realise that information technology has brought us enormous opportunities in sharing our data. In this paper, authors review and introduce the technologies relating to biological data, database, dynamic integration of databases with the World Wide Web (Web hereafter), and data standardisation. |
| Tipo: Journal article |
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| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582002000200010 |
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| Registros recuperados: 10.260 | |
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