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| Hernández Vargas, Juan. |
| La aplicación de plaguicidas en las áreas agrícolas puede causar contaminación ambiental. Por lo general los estudios sobre migración de plaguicidas en los terrenos agrícolas se realizan a través del muestreo periódico del suelo, agua y plantas. Tal enfoque es caro (150.00 USD solamente por análisis de un grupo químico de plaguicidas) y frecuentemente no permite pronosticar el nivel de contaminación potencial a futuro. Existen métodos para minimizar el costo de las investigaciones en campo a través de simulación matemática de los procesos de migración de plaguicidas ante todo en el suelo. Para aplicar estos métodos es necesario conocer algunos parámetros de transporte de plaguicidas en perfil del suelo. En el presente trabajo se realizaron experimentos... |
| Tipo: Tesis |
Palavras-chave: Herbicida; Dispersividad; Velocidad; Degradación; Contaminación; Maestría; Hidrociencias; Herbicide; Dispersivity; Velocity; Degradation; Contamination. |
| Ano: 2008 |
URL: http://hdl.handle.net/10521/1633 |
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| Viveiros,Ana T. M.; Taffarel,Tais R.; Leal,Marcelo C.. |
| This study evaluates the effects of extender osmolality and composition on the cooling of Prochilodus lineatussperm. Sperm was diluted in six extenders: two compositions (powdered coconut water(tm) = ACP; Beltsville Thawing Solution(tm) = BTS) x three osmolalities (285, 325, and 365 mOsm/kg) plus an undiluted control, and stored at 6-8°C. Motility rate and velocities (curvilinear, straight line, and average path) were determined every other day. Osmolality did not affect the quality of cooled sperm, thus data were pooled. Motility was higher on d 0 compared to the other days and diluted samples (85-90%) yielded higher motility than control (75%). On d 2, motility was higher in BTS-diluted samples and control, but on d 4 and 6, control yielded the highest... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: CASA; Cooling; Motility; Semen; Velocity. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252014000300643 |
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| Teresa,Fabrício Barreto; Casatti,Lilian. |
| We assessed the preference of 10 fish species for depth and velocity conditions in forested streams from southeastern Brazil using habitat suitability criteria (HSC curves). We also tested whether preference patterns observed in forested streams can be transferred to deforested streams. We used data from fish sampled in 62 five-meter sites in three forested streams to construct preference curves. Astyanax altiparanae, A. fasciatus, Knodus moenkhausii, and Piabina argentea showed a preference for deep slow habitats, whereas Aspidoras fuscoguttatus, Characidium zebra, Cetopsorhamdia iheringi, Pseudopimelodus pulcher, and Hypostomus nigromaculatus showed an opposite pattern: preference for shallow fast habitats. Hypostomus ancistroides showed a multimodal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Depth; Fish assemblages; Habitat preference; Riparian forest; Velocity. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000200395 |
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