Freshwater requirements of Knysna Estuary

The hydrology of the 335 km 2 catchment of the Knysna River is described using several standard techniques, including those described in Hydrological Research Unit Reports Nos 2/76, 1/72 and 2/78. The mean annual . 6 -1 run-off at the farm Charles ford is about 61 x 10 m3 an. . Salinity measurements were made at various stations between January and June 1984. These data were used to calibrate and verify a 1-dimensiona~ mathematical model of the Knysna Estuary. The model showed that the salinity would rise to 36 parts per thousand at the Old Drift if the · river flow was stopped altogether. The model also shows that salinities drop to 1 or 2 parts per thousand at the National Road Bridge for three successive tides following a one-in-two-year flood -1 ( 40 m 3 s ) • The response of the biota to changing salinities is described using available literature. It appears that there will be a gradual decline in primary and secondary productivity if the river flow is reduced. Other management approaches to this problem as well as the ethical problem of reducing the freshwater inflow into an estuary are explored

Smoking, Green Tea Consumption, Genetic Polymorphisms in the Insulin-Like Growth Factors and Lung Cancer Risk

Insulin-like growth factors (IGFs) are mediators of growth hormones; they have an influence on cell proliferation and differentiation. In addition, IGF-binding protein (IGFBP)-3 could suppress the mitogenic action of IGFs. Interestingly, tea polyphenols could substantially reduce IGF1 and increase IGFBP3. In this study, we evaluated the effects of smoking, green tea consumption, as well as IGF1, IGF2, and IGFBP3 polymorphisms, on lung cancer risk. Questionnaires were administered to obtain the subjects' characteristics, including smoking habits and green tea consumption from 170 primary lung cancer cases and 340 healthy controls. Genotypes for IGF1, IGF2, and IGFBP3 were identified by polymerase chain reaction. Lung cancer cases had a higher proportion of smoking, green tea consumption of less than one cup per day, exposure to cooking fumes, and family history of lung cancer than controls. After adjusting the confounding effect, an elevated risk was observed in smokers who never drank green tea, as compared to smokers who drank green tea more than one cup per day (odds ratio (OR) = 13.16, 95% confidence interval (CI) = 2.96–58.51). Interaction between smoking and green tea consumption on lung cancer risk was also observed. Among green tea drinkers who drank more than one cup per day, IGF1 (CA)19/(CA)19 and (CA)19/X genotypes carriers had a significantly reduced risk of lung cancer (OR = 0.06, 95% CI = 0.01–0.44) compared with IGF1 X/X carriers. Smoking-induced pulmonary carcinogenesis could be modulated by green tea consumption and their growth factor environment

Rotary cylinders : transverse bed motion prediction by rheological analysis

A method for predicting the transverse motion of a granular bed in a rotary cylinder is proposed, based on a non-Newtonian rheological model of the pseudo-plastic type, i.e. with a flow behaviour index (n) between 0 and 1. For a good simulation of bed motion, the model must be able to adequately reproduce the bed velocity profile in both the upper (downward flowing) and the lower (upward moving) zones. It is shown that to do so there is the need to adjust not only the consistency index K but even more importantly the flow behaviour index, n. The mass and momentum conservation equations are solved by the CFD code FLUENT. The model is applied to the simulation of the motion of an alumina bed and the computed results compared with experimental data. On propose une méthode de prédiction du mouvement transversal d'un lit de particules dans un cylindre rotatif, basée sur un modèle rhéologique non-Newtonien du type pseudo-plastique, i.e. avec indice de comportement n entre 0 et 1. Pour bien représenter ce mouvement, le modéle doit pouvoir reproduire les profils de vitesse dans les deux zones du lit, soit la zone supérieure (où les particules descendent) et la zone inférieure (où elles remontent). On montre que pour ce faire, il faut ajuster non seulement l'indice de consistance K mais aussi et surtout l'indice de comportement n, donc un modèle pseudo-plastique est requis. Les équations de conservation de la masse et du mouvement son résolues à l'aide du logiciel FLUENT. Le modèle est utilisé pour simuler le mouvement d'un lit d'alumine et les résultats calculés sont comparés avec l'expérience