Developing a herbicide bioassay for the detection of flucarbazonesodium in three Saskatchewan soils

Non-Peer ReviewedIn this study, a bioassay for determination of flucarbazone residues in soils has been investigated. The response of five crops grown on soils (0-10cm) from three landscape positions was examined in the Brown soil zone. Lentil, field pea, tame oats, chickpea and oriental mustard were grown for five days in soils spiked with 1,3,5,10 and 20 ppb of flucarbazone. Root and shoot length and shoot dry weight were measured and percent growth inhibition was calculated. Root length inhibition provided the most sensitive and consistent indication of herbicide presence in the soil. Of the investigated crops, oriental mustard was the most sensitive in revealing root inhibition from of flucarbazone in the soil with detectable inhibition down to 1 ppb. The mustard also showed the highest degree of inhibition, up to approximately 70% as compared to approximately 50% for the other crops. Percent root growth inhibition was soil dependent; the highest degree of inhibition was observed in the upper slope soil and the lowest in the lower slope soil, indicating that soil properties affect the phytotoxicity of the herbicide in the soil

Factors affecting the phytotoxicity and persistence of Group 2 herbicides in prairie soils

Non-Peer ReviewedAdvantages of Group 2 herbicides include low use rates, broad spectrum weed control and low mammalian toxicity. However,Group 2 herbicides often persist in soil and cause damage to subsequent crops in rotation. Phytotoxicity and persistence are the two parameters that determine the potential damage that could occur from these herbicides. These parameters are affected by soil properties, both chemical and physical, and by environmental factors. Phytotoxicity is often increased and persistence extended by low soil organic matter contents. If the compound is susceptible to hydrolysis, low pH can cause increased rates of dissipation due to this chemical process. Microbial activity and the environmental factors that influence decomposition also play a large role. Increased moisture and temperature typically result in increased microbial activity and decreased persistence. Identifying the factors which are most influential in the phytotoxicity and persistence of Group 2 herbicides is important in managing crop rotations and reducing potential for crop damage

A biochemical and ultrastructural evaluation of the type 2 Gaucher mouse

Gaucher mice, created by targeted disruption of the glucocerebrosidase gene, are totally deficient in glucocerebrosidase and have a rapidly deteriorating clinical course analogous to the most severely affected type 2 human patients. An ultrastructural study of tissues from these mice revealed glucocerebroside accumulation in bone marrow, liver, spleen, and brain. This glycolipid had a characteristic elongated tubular structure and was contained in lysosomes, as demonstrated by colocalization with both ingested carbon particles and cathepsin D. In the central nervous system (CNS), glucocerebroside was diffusely stored in microglia cells and in brainstem and spinal cord neurons, but not in neurons of the cerebellum or cerebral cortex. This rostralcaudal pattern of neuronal lipid storage in these Gaucher mice replicates the pattern seen in type 2 human Gaucher patients and clearly demonstrates that glycosphingolipid catabolism and/or accumulation varies within different brain regions. Surprisingly, the cellular pathology of tissue from these Gaucher mice was relatively mild, and suggests that the early and rapid demise of both Gaucher mice and severely affected type 2 human neonates may be the result of both a neurotoxic metabolite, such as glucosylsphingosine, and other factors, such as skin water barrier dysfunction secondary to the absence of glucocerebrosidase activity

Growth performance and body composition of giant trahira fingerlings fed diets with different protein and energy levels Crescimento e composição corporal de alevinos de trairão alimentados com diferentes níveis de proteína e energia nas dietas

The objective of this work was to determine the proper levels of protein and energy in diets of Hoplias lacerdae fingerlings. The dietary crude protein (CP) and gross energy (GE) levels for fingerlings of giant trahira were evaluated in a completely randomized 4x3 factorial design with 35, 39, 43 and 47% CP and 4,100, 4,300 and 4,500 kcal kg-1 of GE, and four replicates. The survival rate was 99.22%, and a linear improvement on the performance parameters was detected after increasing diet crude protein levels. Feed conversion ratio decreased with increasing levels of dietary protein and energy in the diets. A significant interaction between crude protein and gross energy was observed over body protein and mineral matter. Body lipid has increased linearly as gross energy in the diet increased. The retention of crude protein and energy showed a linear increasing with rising of crude protein levels in the diet. Crude protein level at 47% provides the best performance and energy retention, independently of the gross energy levels in the diet.<br>O objetivo deste trabalho foi determinar os níveis apropriados de proteína e energia em dietas para alevinos de trairão (Hoplias lacerdae). Os níveis de proteína bruta (PB) e energia bruta (EB) foram avaliados em delineamento inteiramente casualizado em esquema fatorial 4x3, com 35, 39, 43 e 47% PB e 4.100, 4.300 e 4.500 kcal kg-1 de EB, e quatro repetições. A taxa de sobrevivência foi de 99,22%, e um aumento linear nos índices de desempenho foi detectado após aumento dos níveis de proteína bruta na dieta. A conversão alimentar decresceu com o aumento dos níveis de proteína e energia na dieta. Foi observada interação significativa entre a proteína e energia bruta sobre a proteína corporal e matéria mineral. O lipídeo corporal aumentou linearmente com o aumento da energia bruta das dietas. A retenção de proteína e energia bruta mostrou aumento linear com os níveis crescentes de proteína bruta nas dietas. Dietas com 47% proteína bruta proporcionam o melhor desempenho e a melhor retenção de energia, independentemente de seus níveis de energia bruta