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| Registros recuperados: 11.818 | |
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| Trejo,Ana; Seijas,Susana. |
| Un sector de 27 km de la Ruta Nacional 258 que une San Carlos de Bariloche con El Bolsón, en la provincia de Río Negro, noroeste de la Patagonia argentina, se recorrió cuatro veces por día durante tres años. El sector considerado se encuentra dentro del Parque Nacional Nahuel Huapi. Todas las aves halladas muertas a lo largo de dicho trayecto se recogieron. Cuando fue posible, se identificó cada individuo como juvenil o adulto. En base a estos datos, se estimó la tasa de atropello para todas las especies en general y para la especie más frecuentemente hallada. Tomando en cuenta el kilometraje de rutas en el parque, se hizo una estimación preliminar del número de aves muertas por atropello en el mismo. Se encontraron 29 aves pertenecientes a 13 familias,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aves; Mortalidad en ruta; Parque Nacional Nahuel Huapi. |
| Ano: 2003 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0073-34072003000200003 |
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| Punta,Gabriel; Yorio,Pablo; Herrera,Gonzalo; Saravia,José. |
| Estudiamos la biología reproductiva de los cormoranes Imperial (Phalacrocorax atriceps) y Cuello Negro (Phalacrocorax magellanicus) en el Golfo San Jorge, Argentina, durante las temporadas reproductivas de 1991-1993. Los fechas en que fueron observados los primeros huevos variaron entre años, siendo entre mediados de octubre y mediados de noviembre para el Cormorán Imperial, y entre fines de octubre y principio de diciembre para el Cormorán Cuello Negro. Durante 1993, el 87% y el 86% de las parejas de Cormorán Imperial y Cormorán Cuello Negro, respectivamente, completaron su nidada en las cuatro semanas siguientes al inicio de la puesta. Para ambas especies, el número de huevos por nido al mes de iniciada la puesta presentó diferencias significativas entre... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Argentina; Biología reproductiva; Cormorán Cuello Negro; Cormorán Imperial; Phalacrocorax atriceps; Phalacrocorax magellanicus. |
| Ano: 2003 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0073-34072003000200004 |
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| Alves Macedo,Gabriela; Soberón Lozano,Maria Mercedez; Pastore,Gláucia Maria. |
| Short chain citronellyl esters were synthesized by a new microbial lipase from Rhizopus sp strain isolated and lipase produced at UNICAMP, Brazil. Direct esterification and transesterification reactions have been performed to produce citronellyl acetate and butyrate in a free-solvent system and with n-hexane in reaction medium. Reaction mixture for direct esterification and transesterification was carried out at 45ºC in equimolar concentration of substrates: acid or ester and alcohol. Only citronellyl butyrate was synthesized by direct esterification with yields from 95 to 100% after 24 hrs. of reaction time, with or without n-hexane. Citronellyl acetate was synthesized by transesterification with ethyl acetate and cytronellol, with yield of 58% after 48... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000100009 |
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| Assis,Odilio B. G.; Claro,Luis C. |
| The protein lysozyme was deposited onto a permeable support comprising chemically functionalized glass fiber. The main objective of this study was to set a stable organic net with no effect on the medium bed permeability and a preliminary test the activity of this enzyme under immobilized conditions. The film formation is followed by atomic force microscopy (AFM) surface imaging. The effect on the bacteria Escherichia coli was tested using a simple microfiltration column. The filtration results pointed around 75% removal of bacteria in the effluent when compared to the influent concentration. The removal mechanism is assumed as being essentially due biointeraction. The surface polarity characteristics of the formed film were also considered as playing an... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000200010 |
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| Raih,Mohd Firdaus; Harmin,Sharr Azni; Ahmad,Hafiza Aida; Mat Isa,Mohd Noor; Mahadi,Nor Muhammad; Ibrahim,Abdul Latif; Mohamed,Rahmah. |
| Bioinformatics is a necessary technology and tool, which current molecular biologists cannot do without in light of the genome data explosion and advent of fields such as genomics and proteomics. Yet, even with this in mind, there is still a limited pool of human resource to support and develop bioinformatics particularly in poorer developing nations. The highly multidisciplinary nature of this field can be an obstacle in converting just any molecular biologist into a proficient and capable bioinformaticist. Coupled with the high costs of software, hardware, technical maintenance and systems support; many developing and poor countries may not be able to fully realize their biotech potential either academically or economically due to the inability to fully... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000100003 |
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| Antunes,Wallace M.; Luna,Aderval S; Henriques,Cristiane A; da Costa,Antonio Carlos A. |
| A basic investigation into the removal of copper ions from aqueous solutions by Sargassum sp. was conducted in batch conditions. The influence of different experimental parameters such as initial pH, shaking rate, sorption time, temperature, equilibrium conditions and initial concentrations of copper ions on copper uptake was evaluated. Results indicated that for shaking rates higher than 100 rpm no significant changes in copper accumulation were observed, as well as for pH values between 3.0 and 5.0. No marked effect on the biosorption of copper was detected for temperatures between 298 and 328K. The Langmuir model better represented the sorption process, in comparison to the model of Freundlich. The process followed a second-order kinetics and its... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000300003 |
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| Hernández García,Armando; Pimentel Vázquez,Eulogio; Mena Campos,Jesús. |
| A simple and economical minibioreactor-gas collector system for determination of hydrogen sulfide produced by a microorganism was designed. The detection of hydrogen sulfide was based on the reaction between the hydrogen sulfide in the gas stream from the culture, and a lead acetate solution 0.090 mol/L, contained in a tube gas collector; the conductimetric back titration of lead excess was made, and hydrogen sulfide was quantified indirectly, being the detection limit 0.5 µmol. The developed system was applied using Tsukamurella paurometabola DSM 20162 as a model, being the amount of hydrogen sulfide produced, 1.2 µmol in 24 hrs. |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000300007 |
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| Martínez,Liliana; Cavagnaro,Pablo; Masuelli,Ricardo; Rodríguez,José. |
| Half of the Argentine grapevine growing area is cultivated with local varieties generically called "Criollas". These materials differ in morphology, physiology and enological aptitudes from traditional European varieties. To discriminate among them, we used morphological markers to evaluate the genetic diversity and phenetic relatedness of 9 Criollas, 6 European and 1 American varieties and compared with AFLP markers. Three AFLP primer combinations generated a total of 111 scorable fragments. Dendrograms obtained with morphologic and AFLP markers agreed in clustering the "Criollas" separately from the European and American varieties assayed, except for Muscat d Alexandrie and Tempranillo which clustered with Criollas in the case of AFLP. Comparison of... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000300009 |
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| Thakur,Archana. |
| RNA interference (RNAi) is a potent method using only a few double stranded RNA (dsRNA) molecule per cell to silence the expression which has made it one of the hottest topics in molecular biology in last two years. Not long ago scientists conducted gene knock out using antisense, dominant negative or knockout techniques which were ineffective, but the discovery of RNAi has enabled to knock out gene in any organism efficiently. RNA silencing was first discovered in transgenic plants, where it was termed co-suppression or post transcriptional gene silencing (PTGS). Five years ago the evidence for RNA silencing emerged from experimental observation on Caenorhabditis elegans, this new approach for achieving efficient, targeted gene silencing is now making its... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000100007 |
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| Sedarati,Mohammad R; Keshavarz,Tajalli; Leontievsky,Alexey A; Evans,Christine S.. |
| Free-cell cultures of Trametes versicolor were compared with cultures immobilized on nylon mesh in a 2-litre bioreactor for transformation of pentachlorophenol (PCP) and 2,4-dichlorophenol (2,4-DCP), added at intervals to the liquid culture medium over a period of 816 hrs. Increasing amounts of PCP from 200 ppm to 2000 ppm added batchwise to cultures permitted acclimatization of the fungus to these toxic pollutants. A total addition of 2000 ppm of 2,4-DCP and 3400 ppm PCP were removed from the immobilized cultures with 85% of 2,4-DCP and 70% of PCP transformed by enzymes (laccase and Mn-peroxidase), 5% 2,4-DCP and 28% PCP adsorbed by the biomass and 10% 2,4-DCP and 2% PCP retained in the medium at the termination of the fermentation after 1020 hrs. In... |
| Tipo: Journal article |
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| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582003000200005 |
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| Registros recuperados: 11.818 | |
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