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1.
Jean François Emard Pierre Andre Jean -Pierre Thouez Jean Mathieu Camil Boily Michel Beaudry Andree Cholette Yves Robitaille Remi Bouchard Nicolas Daoud Francine Veilleux Denis Gauvreau 《Water, air, and soil pollution》1994,72(1-4):251-264
Accepting as founded the hypothesis of a multifactorial origin for the Alzheimer's disease (AD), we explore the possible links between the geographical distribution of AD cases according to their birth place and the geochemical profile of the Saguenay-Lac-Saint-Jean (SLSJ) territory in the province of Québec. The method used for factor analysis of correspondances (FAC) and another one based on the differences between the residential and municipal geochemical concentrations (DRMC) have been used for this purpose. The geochemical matrix of SLSJ relates the highest concentrations of nickel, copper and zinc to the sector surrounding the Jonquière municipality. Moreover, high concentrations of iron, lead and manganese were found in the northern sector of the Lac Saint-Jean. The DRMC method corroborates this strong correlation between iron, lead and manganese. Furthermore, these concentrations do not differ from the north-american geochemical standards. No single geochemical element seems to be associate with the spatial distribution of cases. It is, however, still possible that a certain synergistic effect between two or several elements could be implied in the development of the disease. According to the results of the soil analysis, there does not seem to be any association between the spatial distribution of cases and the concentration of aluminum, a chemical element that has been thought to be implied in the etiology of AD. These results are compared with those obtained by other workers in the micronesian islands, where abnormally high frequencies of amyotrophic lateral sclerosis and parkinsonism dementia have already been observed. 相似文献
2.
Effects of garlic powders with varying alliin contents on hepatic drug metabolizing enzymes in rats 总被引：3，自引：0，他引：3
Le Bon AM Vernevaut MF Guenot L Kahane R Auger J Arnault I Haffner T Siess MH 《Journal of agricultural and food chemistry》2003,51(26):7617-7623
The anticarcinogenic effect of garlic has been demonstrated in both epidemiologic and experimental studies. In this study, possible mechanisms involved in the anticarcinogenic effect of garlic consumption were assessed by determining its capacity to alter drug metabolizing enzymes, in relation with its alliin content. Rats were fed a diet for 2 weeks containing 5% garlic powders produced from bulbs grown on soils with different levels of sulfate fertilization and therefore containing differing amounts of alliin. Activities of several hepatic enzymes, which are important in carcinogen metabolism such cytochromes P450 (CYP) and phase II enzymes, were determined. Garlic consumption slightly increased ethoxyresorufin O-deethylase and CYP 1A2 levels. In contrast, garlic consumption decreased CYP 2E1 activity and the level of the corresponding isoform. UDP glucuronosyl transferase and glutathion S-transferase activities were increased by garlic powders. The alliin content of the garlic powders was positively correlated with UGT activity although not with other activities. Effects produced by garlic consumption were qualitatively similar to that of diallyl disulfide, a sulfur compound that has been extensively studied. These data could partially explain the chemoprotective effect of garlic. 相似文献
3.
Damilare Stephen Akinyemi Oseni S. Remi Abdul Shakoor Oke S. Olajide 《Journal of Sustainable Forestry》2019,38(3):292-304
Species co-occurrence and nestedness pattern in Shasha forest reserve were investigated with a view to determining the effect of interactions to species contribution. Three distinct sites (Gmelina arborea plantation, undisturbed forest, and Pinus carribaea (plantation) were selected in the forest reserve. Four 25 m × 25 m plots were established in each of the site within the forest reserve. Species enumeration, identification,, and distribution into families of the standing vegetation were carried out. Woody species represented the most diverse life form. Plant species diversity was highest in UF and lowest in Gmelina plantation. Differences in woody species composition among the three forest types were determined by non-metric multidimensional scaling (NMDS) analysis, analysis of similarity (ANOSIM), and similarity of percentages. Using z-score and NODF (a nestedness metric based on overlap and decreasing fill). Three modules were detected and modularity score Q = 0.2. The composition analyses (NMDS and ANOSIM) revealed a significant difference in the woody species composition among the forest types. Our research may contribute to understand species assemblage in one of the diverse forests of Africa. Current work highlighted species occurrence in Shasha forest and highlighted the importance of non-random pattern which could serve as framework for conservation perspective. 相似文献
4.
This study presents four strategies of a novel evolutionary algorithm, multi-objective differential evolution algorithm (MDEA). The four strategies namely, MDEA1, MDEA2, MDEA3 and MDEA4 are adapted to solve the multi-objective crop planning model with multiple constraints in a farmland in the Vaalharts irrigation scheme (VIS) in South Africa. The three objectives of the model are to minimize the total irrigation water (m2) and to maximize both the total net income in South African Rand (ZAR) from farming and the total agricultural output in tons. The total area of the farm is 771,000 m2 and supplied with 704,694 m2 of irrigation water annually. Numerical results produce non-dominated solutions which converge to Pareto optimal fronts. MDEA1 and MDEA2 strategies with binomial crossover method are better for solving the crop planning problem presented than MDEA3 and MDEA4 strategies with exponential crossover method. MDEA1 found a solution with the highest total net income of ZAR 1,304,600 with the corresponding total agricultural output, total irrigation water and total planting areas of 316.26 tons, 702,000 m3 and 725,000 m2, respectively. The planting areas for the crops in the solution are 73,463 m2 for maize, 551,660 m2 for groundnut, 50,000 m2 for Lucerne and 50,000 m2 for Peacan nut. It can be concluded that MDEA is a good algorithm for solving crop planning problem especially in water deficient areas like South Africa. 相似文献
5.
More accurate spatio-temporal predictions of urban environment are needed as a basis for assessing exposures as a part of environmental studies and to inform urban protection policy and management. In this study, an information system was developed to manage the physico-chemical pollution information of Ibadan river system, Oyo State, Southwest Nigeria. The study took into account the seasonal influences of point and non-point discharges on the levels of physico-chemical parameters. The overall sensitivity of the watershed to physicochemical environmental pollution revealed that during dry season, of the 22 (100%) sample points, only 3 (13.6%) were unpolluted; 6 (27.3%) were slightly polluted; 10(45.4%) were moderately polluted; 2 (9.1%) were seriously polluted and 1 (4.5%) was exceptionally polluted. During rainy season, 3 (13.6%) were unpolluted; 7 (31.8%) were slightly polluted; 9 (40.9%) were moderately polluted; 2 (9.1%) were seriously polluted and 1 (4.5%) was exceptionally polluted. There is a considerable environmental risk associated with the present level of pollution of the Ibadan river water body on fish health and biodiversity. This research provides a basis for aquatic management and assist in policy making at national and international levels. Appropriate strategies for the control of point and non-point pollution sources, amendments and enforcement of legislation should be developed. 相似文献
6.
Mariko Shoji Hidenori Sato Remi Nakagawa Ryo Funada Takafumi Kubo Shinjiro Ogita 《Journal of Forest Research》2006,11(6):449-453
The effect of an osmoticum, polyethylene glycol (PEG), on somatic embryo production was examined using embryogenic cells of
Pinus densiflora. In the basal medium containing 30 μM abscisic acid and 6% maltose, the quality of the embryos formed was poor even though
somatic embryos were produced. The addition of PEG with molecular weight of 4000 or 8000 significantly enhanced the development
of both the quality and quantity of somatic embryos. Furthermore, higher levels of a constant osmotic pressure with PEG 8000
in a range from about 300 to 450 mmol/kg could remarkably enhance the morphogenesis of somatic embryos and their number of
embryos produced. A higher stable osmotic pressure with an appropriate molecular weight of PEG is a key factor for the production
of good quality somatic embryos in P. densiflora. 相似文献
7.
Daniel L Merrifield Dean Burnard Graham Bradley Simon J Davies & Remi T M Baker 《Aquaculture Research》2009,40(9):1064-1072
Bacterial communities from the intestinal tract of rainbow trout were investigated to assess transient and resident microbial communities using both culture-based and culture-independent techniques. Viable counts attached to the intestinal mucosa were in the range of log 4.77–5.38 and log 6.67–6.79 CFU g−1 in the intestinal contents. Pseudomonas spp. and Enterobacteriaceae constituted nearly 80% of the allochthonous population but <60% of the autochthonous populations. This coincided with an elevated mucosal level of a group of Gram-positive rods from ∼2% in the digesta to 25–35% on the mucosa. This group was identified by 16S rRNA as Arthrobacter aurescens and Janibacter spp. HTCC2649. Analysis of denaturing gradient gel electrophoresis banding patterns showed complex communities in all intestinal regions. Similarity coefficients showed that mucosal communities were ∼70% similar to digesta communities and yet due to the presence of bands found uniquely either in the digesta or on the mucosa, the communities are distinctly different. Scanning electron microscopy confirmed mucosal bacterial populations and highlighted a possible localized colonization between mucosal folds. The study highlights the complexity of resident microbial communities that have not been fully explored in previous rainbow trout studies; this is especially true with probiotic/prebiotic investigations. 相似文献
8.
Summary Ten West African Dwarf ewes were inoculated withTrypanosoma vivax and, at varying intervals, treated subcuratively with diminazene aceturate to maintain the infection. Soon after infection all ewes and anoestrus for 40 to 96 days and 5 died by day 110 post infection. Compared to control animals, infected ewes had prolonged low levels of plasma progesterone until recovery or death. However, no gross or histological lesions were detected in the endocrine or reproductive organs. Of the survivors, the 5 that were aparasitaemic subsequently became pregnant and had normal gestations.
Tripanosomiasis Y Reproduccion: I. Effecto E Infecciones ConTrypanosoma vivax Sobre El Ciclo Estrual Y Reproduccion En La Oveja
Resumen Se inocularon 10ovejas West African Dwarf conTrypanosoma vivax y fueron tratadas periódicamente con dosis subcurativas de aceturato de diminazene, para mantener la infección. Pronto despues de la infección, todas las ovejas presentaron anestro por 40 a 96 dias y 5 murieron 110 dias después de la infección. Comparadas con controles, las ovejas infectadas presentaron niveles bajos de progesterona plasmática, hasta recuperación o muerte. Sin embargo, no se encontraron lesiones macroscópicas ni histológicas en los órganos reproductivos o endocrinos. De las sobrevivientes, las 5 que fueron aparasitémicas quedaron posteriormente preñadas y tuvieron gestaciones normales.
Trypanosome Et Reproduction. I. Effet De La Trypanosomose AT. Vivax Sur Le Cycle Oestral Et La Fecondite Chez La Brebis
Résumé Dix brebis naines de l'Afrique de l'ouest ont été inoculées avecTrypanosoma vivax et, à intervalles variés, traitées avec e l'acéturate de diminazène à dose non curative pour maintenir l'infection. Peu après celle-ci, toutes les brebis ont présenté un anoestrus de 40 à 96 jours et 5 sont mortes le 110e jour après l'infection. Comparées aux animaux témoins, les brebis infectées ont montré des taux peu élevés et polonges de progestérone du plasma jusqu'à leur guérison ou leur mot. Cependant, aucune lésion importante ou histologique n'a été décelée dans les organes de reproduction ou endocriniens. Parmi les survivantes, les 5 qui n'étaient pas parasitées sont entrées en gestation et l'ont menée normalement à terme.相似文献
9.
Xylem vulnerability to cavitation is a key parameter in understanding drought resistance of trees. We determined the xylem water pressure causing 50% loss of hydraulic conductivity (P(50)), a proxy of vulnerability to cavitation, and we evaluated the variability of this trait at tree and population levels for Fagus sylvatica. We checked for the effects of light on vulnerability to cavitation of stem segments together with a time series variation of P(50). Full sunlight-exposed stem segments were less vulnerable to cavitation than shade-exposed ones. We found no clear seasonal change of P(50), suggesting that this trait was designed for a restricted period. P(50) varied for populations settled along a latitudinal gradient, but not for those sampled along an altitudinal gradient. Moreover, mountainside exposure seemed to play a major role in the vulnerability to cavitation of beech populations, as we observed the differences along north-facing sides but not on south-facing sides. Unexpectedly, both north-facing mountainside and northern populations appeared less vulnerable than those grown on the southern mountainside or in the South of France. These results on beech populations were discussed with respect to the results at within-tree level. 相似文献
10.