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1.
During the last decade it has been argued by some investigators that the distribution of galaxies in the Universe is a fractal. This is contrary to the standard view that the Universe is homogeneous and isotropic on large scales. In this article, the basic concepts of fractals and their characterization are introduced with the help of simple examples. The applications of these concepts in the context of cosmology will be discussed in the second part. A K Mittal is currently a visiting scientist at Harish-Chandra Research Institute, Allahabad, on leave from the University of Allahabad. His research interests include chaos, fractals and their applications, partleularly in cosmology and in weather prodiction. T H Seshadri is at the Department of Physics and Astrophysics, University of Delhi. He is presently on lien from Harish-Chandra Research Institute, Allahabad. Areas of his interest include cosmic microwave background radiation, large scale structures in the Universe and application of fractals in these.  相似文献   
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Association of cholesteryl ester transfer protein (CETP) Gene -629C/A Polymorphism with angiographically proven atherosclerosis CETP gene has been linked to CAD risk via its role in HDL and LDL metabolism. There is no agreement of whether CETP is atherogenic or not. Furthermore, various genotypes of CETP gene have been associated with CETP levels and thus with atherosclerosis risk. Our aim was to study the association of CETP -629C/A gene polymorphism with CETP and HDL levels and their association if any with atherosclerosis. Study population consisted of angiographically documented 50 cases with coronary artery atherosclerosis and 50 controls negative for atherosclerosis of coronary artery. Serum lipid profile was measured on SYNCHRON CX-9 using standard kits. Serum CETP levels were measured by ELISA method. CETP -629C/A gene polymorphism was studied using PCR–RFLP method. There was no significant difference in lipid profile of the two groups. However, serum CETP level was significantly higher (46.44 ± 21.75 ng/ml) in cases than controls (37.10 ± 21.92 ng/ml) with p value =0.035. The frequency of -629A allele was higher (0.85) in cases than that of controls (0.81). Homozygosity of A allele was more in subjects with atherosclerosis of coronary artery. We conclude that CETP is atherogenic and could be used as atherogenic risk predictor in angiographically proven atherosclerosis. Also A allele of -629C/A polymorphism is more prevalent in cases; indicating its effect on expression of CETP gene.  相似文献   
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To study the protective role of Arogh on isoproterenol induced myocardial damage in rats. The effect of Arogh pretreatment on isoproterenol induced myocardial damage was assessed by studying the levels of lipid peroxides and changes in the activity of marker enzymes such as creatine kinase, lactate dehydrogenase and transaminases in serum and heart tissue. In isoproterenol administered rats, a significant decrease was observed in the activity of marker enzymes in the heart with a corresponding increase in their levels in serum. Lipid peroxide levels increased significantly in the serum and heart. In rats pretreated with arogh, the level of lipid peroxides and the activity of marker enzymes were maintained at near normal values. Pretreatment with Arogh offered a protective effect against isoproterenol induced myocardial damage in rats as evidenced by LDH isoenzyme patterm and histopathological studies of heart tissue.  相似文献   
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Purpose: The key informants in a village setup were studied to understand the existing social and knowledge systems of farmers, their structure, and relationships between different actors. The purpose is to identify different channels of information and use them as a means to disseminate agricultural technologies and related information to farmers.

Design: We use the network map analysis in a case study approach as a tool to demonstrate the linkages between the key actors and stakeholders in the information network of farmers.

Findings: The government institutions are well networked among themselves but have limited interactions with non-government sources. Farmers in Bihar have strong linkages with few network actors, who are important nodes in the social knowledge network. The study showed heterogeneity and complexity in the network shape and structure across different districts.

Practical Implications: Knowledge networks and social networks are the drivers of information sharing and play a significant role in the diffusion of agricultural technology and related knowledge. Understanding these networks provides a platform for introducing the agricultural technologies and getting connected to a wider group of farming communities.

Theoretical Implications: The study shows that the network is formed by different actors and their role determine the nature and shape of the network. Knowledge of this heterogeneity is important in designing or revamping agricultural information systems.

Originality: Information and knowledge networks are least explored in the agricultural information dissemination process. Some studies have shown the role of actors and social networks, but this study uniquely explores and presents the heterogeneity of these networks.  相似文献   

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The present, study was conducted to determine the level of malondialdehyde (MDA) as an index of free radial induced lipid peroxidation and antioxidant vitamins-vitamins A, vitamin C and vitamin E in 75 confirmed cases of urolithiasis. Significantly high level of MDA (p<0.001) with significantly low levels of vitamin E (p<0.001) and vitamin A (p<0.001) with no significant decrease in vitamin C (p>0.05) were observed in the plasma of urolithiasis cases as compared to normal controls. In conclusion, it appears that a role of lipid peroxidation and oxidative function exists in the pathogenesis of urolithiasis. But, the exact mechanism how this occurs remains to be elucidated.  相似文献   
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In Part 1 of this article, we had introduced the reader to some basic concepts of fractals and some operational algorithms to characterize them. We had also pointed out and clarified some common misconceptions about fractals. In this part we apply the fractal concepts to large-scale structures in the Universe. In particular we discuss the claim by some investigators that the distribution of galaxies in the Universe is a fractal. This is contrary to the standard view that the Universe is homogeneous and isotropic on large scales. Also discussed is the controversy as to whether the matter distribution in the Universe is a fractal on large-scales.  相似文献   
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A comparative study was made on the tissue specific expression of glutathione transferases (GST) in brain and testis after exposure of rat to phenobarbitol (PB) and β-methylcholanthrene (MC). Glutathione transferases, a family of multifunctional proteins are involved in intracellular transport processes and in detoxication of electrophilic xenobiotics by catalyzing reactions such as conjugation, isomerization, reduction and thiolysis. On purification, the yield of GST proteins by affinity chromatography was 39% in testis and 32% in brain. The affinity purified testis GSTs were resolved by chromatofocusing into six anionic and four cationic isozymes, and in brain glutathione transferases were resolved into four anionic and three cationic isozymes, suggesting the presence of multiple isozymes with Yc, Yb, Yβ and Yδ in both of them. In testis and brain, these isozymes at identical pI values showed variable functions with a battery of substrates and the cationic isozymes of brain and testis showed identical properties in CHP (cumene hydroperoxide) at pH values of above 7.0. Substrate specificity studies and immunoblot analysis of testis and brain proteins revealed that they play a predominant role in the detoxication of phenobarbitol or β-methylcholanthrene. Expression of the isozymes in testis and brain on exposure to PB and MC indicated elevated subunit variation. In both testis and brain, Yδ of π class was expressed on PB treatment and Yc of α class and Yβ of μ class was expressed in MC treated testis and only Yc was predominantly expressed in MC treated brain. Thus these subunits expression is considered as markers for carcinogenesis and specific to chemical toxicity under phenobarbitol and β-methylcholanthrene stress. Project supported by Department of Science and Technology and Council for Scientific and Industrial Research, New Delhi  相似文献   
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Metabolic abnormalities were investigated in 44 stone patients with first time (group 1) and 56 with 2 times stone formation (group 2), and in 25 normal individuals. 24hr urine was analysed spectrophotometrically for oxalate, calcium, magnesium, citrate, uric acid, phosphate and creatinine. Hypocitraturia and hyperoxaluria were the common abnormalities in the stone formers. Stone patients had significantly higher urinary oxalate, calcium and uric acid and lower phosphate than normal individuals. Citrate/calcium and magnesium/calcium ratio were significantly high in normal individuals than stone formers. Patients in group 2 excreted significantly higher urinary calcium and lower citrate that patients in group 1. Citrate/calcium ratio was higher in group 1 than group 2. Hypocitraturia, hyperoxaluria, hypercalciuria and increased citrate/calcium and magnesium/calcium ratio seem to be an essential risk factor for stone formation. Patients with recurrent stone formation could be distinguished from patients with first time stone formation on the basis of urinary calcium and citrate.  相似文献   
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