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31.
Error and attack tolerance of small-worldness in complex networks   总被引:1,自引:0,他引:1  
Complex networks may undergo random and/or systematic failures in some of their components, i.e. nodes and edges. These failures may influence various network properties. In this article, for a number of real-world as well as Watts–Strogatz model networks, we investigated the profile of the network small-worldness as random failures, i.e. errors, or systematic failures, i.e. attacks, occurred in the nodes. In errors nodes are randomly removed along with all their tipping edges, while in attacks the nodes with highest degrees are removed from the network. Interestingly, in many cases, the small-worldness of violated networks increased as more nodes underwent an attack. This indicates an important role of the hub nodes in controlling the small-worldness of Watts–Strogatz networks. The profile of changes in the small-worldness as a result of errors/attacks was independent of network size, while it was influenced by average degree and rewiring probability of Watts–Strogatz model. We also found that the pattern of the changes of the small-worldness in real-world networks is completely different than that of the Watts–Strogatz networks. Therefore, although Watts–Strogatz model is often used for constructing networks with small-world property, the resulting networks have different properties compared to real-world ones in terms of robustness in the small-worldness index against errors/attacks.  相似文献   
32.
The pathogenesis of idiopathic nephrotic syndrome is not completely understood. We postulate that cytokine gene polymorphisms may influence susceptibility or clinical course in Idiopathic Nephrotic Syndrome. Polymorphisms of IL-4, IL-6, and TNF-α cytokines were investigated in 150 children with Idiopathic Nephrotic Syndrome and 569 healthy controls by using polymerase chain reaction and restriction fragment length polymorphism. On comparing patient with controls strong association were found for IL-6, TNF-α and IL-4 at allelic level (IL-6-G174C (G vs. C): P = <0.001; OR = 6.33, TNF-α-G308A (G vs. A): P = <0.001; OR = 1.99, IL-4-C590T (C vs. T): P = 0.048; OR = 1.38). Further when SR group was compared with SS group significant association was found at genotypic level in all the studied genetic polymorphisms. Studied cytokine gene polymorphisms may influence susceptibility to idiopathic nephrotic syndrome and might affect steroid response in INS patients.  相似文献   
33.
To correlate blood lead levels (BLLs) and oxidative stress parameters in pregnant anemic women. A total of 175 pregnant women were found suitable and included for this study. Following WHO criteria, 50 each were identified as non-anemic, mild anemic and moderate anemic and 25 were severe anemic. The age of all study subjects ranged from 24–41 years. At admission, BLLs and oxidative stress parameters were estimated as per standard protocols and subjected with ANOVA, Pearson correlation analysis and cluster analysis. Results showed significantly (p < 0.01) high BLLs, zinc protoporphyrin (ZPP), oxidized glutathione (GSSG), lipid peroxide (LPO) levels while low delta aminolevulinic acid dehydratase (δ-ALAD), iron (Fe), selenium (Se), zinc (Zn), haemoglobin (Hb), haematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), red blood cell (RBC) count, reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and total antioxidant capacity (TAC) in all groups of anemic pregnant women as compared with non anemic pregnant women. In all groups of pregnant women, BLLs showed significant (p < 0.01) and direct association with ZPP, GSSG and LPO while inverse relation with δ-ALAD, Fe, Se, Zn, Hb, Hct, MCV, MCH, MCHC, RBC, GSH, SOD, CAT and TAC. Study concluded that low BLLs perturb oxidant-antioxidant balance and negatively affected hematological parameters which may eventually Pb to Fe deficiency anemia during pregnancy.  相似文献   
34.
Lead ranks as one of the most serious environmental poisons all over the world amongst toxic heavy metals with no known biological function useful for the human body. A case of lead toxicity due to consumption of herbal medicine is being discussed. The case presented with gastrointestinal complaints and history of intake of herbal medicines for diabetes control for past 8 months. The analysis of the powdered herbal medicine procured from ayurveda practitioner was found to have high content of lead responsible for the lead toxicity. The patient is under regular followup. He has improved symptomatically on chelating therapy and blood lead levels have gradually improved. Regular awareness programs should be conducted in the population regarding possible exposure through home made herbal remedies so that general public can be made aware of the dangerous side effects of lead and other heavy metals on health.  相似文献   
35.
The present study was undertaken to evaluate antidiabetic and antioxidant activities of Cassia tora (C. tora) seeds extract against streptozotocin induced diabetes in experimental rats to scientifically validate its use against diabetes. Ethanolic extract of C. tora seeds extract and standard drug (glibenclamide) prepared in aqueous gum acacia (2 %, w/v) suspension and fed orally to streptozotocin induced male adult diabetic rats of Charles Foster strain for 15 days. Biochemical parameters in normal, diabetic control, standard (600 μg/kg bw p.o.) and treated (500 mg/kg bw p.o.) animal groups were quantified and compared. Treatment of streptozotocin induced diabetic rats with ethanolic seeds extract caused significant (p < 0.001) reduction in blood glucose (270–220 mg/dl), total cholesterol (140–104 mg/dl), triglyceride (149–99 mg/dl), phospholipids (100–74 mg/dl), free fatty acid (2.39–2.00 μmol/l), lipid peroxide (9–5.63 nmol MDA/dl) and significantly increased post heparin lipolytic activity (11–14 nmol FFA released/h/l plasma) (p < 0.001). Furthermore, the seeds extract (100–400 μg) when tested for its antioxidant activity in vitro, showed significant (p < 0.001) inhibition in the generation of super oxide anions in enzymic system a (46–37, 33, 23, 21 nmol uric acid formed/min), in enzymic system b (113–91, 77, 60, 51 nmol formazon formed/min), non-enzymic system (324–230, 211, 161, 141 nmol uric acid formed/min) and hydroxyl radicals in enzymic system (544–501, 411, 319, 291 nmol 2,3-dihydroxybenzoate formed/h) and non-enzymic system (28–21, 17, 14, 12). The results of the present study demonstrated antidiabetic, antidyslipidemic and antioxidant activities of C. tora seeds which could help in prevention of diabeticdyslipidemia and related complications.  相似文献   
36.
Osteoporosis is a systemic disease with a strong genetic component. Vitamin D receptor (VDR) has been suggested as a candidate gene for osteoporosis. Therefore the present study was aimed to investigate the pattern of allelic variants of VDR gene polymorphism (FokI and BsmI), its influence on vitamin D levels and bone mineral density (BMD) in North Indian postmenopausal women with osteoporosis for possible genetic association. 254 postmenopausal osteoporotic women and 254 postmenopausal non osteoporotic women were included in the study. VDR FokI and BsmI gene polymorphism gene were assessed by the PCR-RFLP method. Serum 25-hydroxyvitamin D was measured by the ELISA. BMD at the L1–L4 lumbar spine, hip, forearm and femoral neck was assessed by dual energy X-ray absorptiometry. The average BMD at spine and hip in postmenopausal women with bb and spine, hip, femoral neck and forearm with ff genotype had significantly low BMD. The frequency of ff genotype and f allele was significantly higher in postmenopausal osteoporotic women when compared with postmenopausal non osteoporotic women. However, no significant association was found between the genotypes and vitamin D levels. Our study reveals that VDR gene FokI and BsmI polymorphism is significantly associated with low bone mineral density. Therefore the ff genotype and f allele of VDR FokI gene may be used as an important risk factor for osteoporosis.  相似文献   
37.
In the present study the antioxidative potential ofMomordica charantia, Azadirachta indica, Allium sativum andOcimum sanctum was assessed in streptozotocin induced diabetic rats. Lipid peroxide levels were also measured in normal, diabetic and treated animals. Malondialdehyde (MDA) levels were significantly higher and antioxidant activity was found low in diabetic groups as compared to the control groups, and significant alteration in both the MDA levels and antioxidant activity was also observed when the above herbal hypoglycemic agents were given to diabetic rats. On the basis of our results we conclude thatM. charantia, A. indica, A. sativum andO. sanctum are not only useful in controlling the lipid peroxide levels but are also helpful in further strengthening the antioxidant potential.  相似文献   
38.
The hypolipidemic activity of Cassia tora (Chakvat, Chakunda) (Family: Caesalpiniaceae) seeds extract have been studied in two models of hyperlipidemia in rats. In an acute model, hyperlipidemia was induced by injecting a single dose of Triton WR-1339 (400 mg/kg, b.w.) intraperitonially in rats. Feeding with C. tora seed extract at the dose of 500 mg/kg, b.w. exerted significant lipid lowering effect as assessed by the reversal of plasma levels of total cholesterol, phospholipids, triglyceride and reactivation of post heparin lipolytic activity. In the chronic model, hyperlipidemia was induced by feeding with cholesterol rich-HFD in rats. The treatment with seeds extract of C. tora (500 mg/kg, b.w.) simultaneously for 15 days also caused lowering of lipid levels in plasma and liver following reactivation of plasma post heparin lipolytic activity and hepatic lipoprotein lipase activity in animals. The hypolipidemic activity of C. tora seeds was compared with a standard drug guggulipid (200 mg/kg, b.w.) in both models.  相似文献   
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40.
Research has documented overlapping and coexisting characteristics of learning disabilities (LD) and emotional and behavioural difficulties (EBD). Such concomitance may impact teacher referrals of children at risk for LD which in turn may influence service delivery. Using the Learning Disabilities Diagnostic Inventory (LDDI) and the Strengths and Difficulties Questionnaire (SDQ), we examined teachers’ ratings of EBD and LD symptoms in 439 students referred for LD in elementary schools in Oman. A multivariate analysis of variance (MANOVA) showed that there were no gender differences in LD symptoms, whereas there were significant gender differences in teachers’ ratings of hyperactivity and conduct problems in referred children. There was an association between teachers’ ratings on the LDDI and SDQ dimensions, reflecting children’s concurrent display of LD and EBD symptoms. Implications are discussed within an Omani context in which there is a need to increase teachers’ awareness of the behavioural and emotional profile of children at risk for LD.  相似文献   
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