163 research outputs found

    An access control and authorization model with Open stack cloud for Smart Grid

    Get PDF
    In compare to Authentication for identification and relationship of an identity of a user with its task and process within the system, authorization in access control is much anxious about confirming that user and its task in the form of system process, access to the assets of any particular domain is only approved when proven obedient to the identified policies. Access control and authorization is always an area of interest for researchers for enhancing security of critical assets from many decades. Our prime focus and interest is in the field of access control model based on Attribute base access control (ABAC) and with this paper we tried to integrate ABAC with openstack cloud for achieving finer level of granularity in access policies for domain like smart grid. Technical advancement of current era demands that critical infrastructure like traditional electrical grid open ups to the modern information and communication technology to get the benefit in terms of efficiency, scalability, accessibility and transparency for better adaptability in real world. Incorporation of ICT with electric grid makes it possible to do greater level of bi-directional interaction among stake holders like customer, generation units, distribution units and administrations and these leads international organization to contribute for standardization of smart grid concepts and technology so that the realization of smart grid becomes reality. Smart grid is a distributed system of very large scale by its nature and needs to integrate available legacy systems with its own security requirements. Cloud computing proven to be most efficient approach for said requirements and we have identified openstack as our cloud platform. We have integrated ABAC approach with default RBAC approach of openstack and provide a frame work that supports and integrate multiple access control polices in making authorization decisions. Smart grid domain in considered as case study which requires support of multiple access policies (RBAC, ABAC or DAC etc) with our model for access control and authorization

    Antibacterial apple cider vinegar eradicates methicillin resistant Staphylococcus aureus and resistant Escherichia coli

    Get PDF
    Methicillin-resistant Staphylococcus aureus (MRSA) and resistant Escherichia coli (rE.coli) infections can spread rapidly. Further they are associated with high morbidity and mortality from treatment failure. Therapy involves multiple rounds of ineffective antibiotics alongside unwanted side effects, alternative treatments are crucial. Apple cider vinegar (ACV) is a natural, vegan product that has been shown to have powerful antimicrobial activity hence we investigated whether ACV could ameliorate these resistant bacteria. The minimum dilution of ACV required for growth inhibition was comparable for both bacteria (1/25 dilution of ACV liquid and ACV tablets at 200 µg/ml were effective against rE. coli and MRSA). Monocyte co-culture with microbes alongside ACV resulted in an increase in monocyte phagocytosis by 21.2% and 33.5% compared to non-ACV treated but MRSA or rE. coli stimulated monocytes, respectively. Label free quantitative proteomic studies of microbial protein extracts demonstrated that ACV penetrated microbial cell membranes and organelles, altering the expression of key proteins. This resulted in significant reductions in total protein expression, moreover we could only detect ribosomal proteins; 50 s 30 s, enolase, phosphenol pyruvate and the ATP synthase subunit in rE. coli. Elongation factor iNOS and phosphoglycerate kinase OS were the only proteins present in MRSA samples following ACV treatment

    Antimicrobial activity of apple cider vinegar against Escherichia coli, Staphylococcus aureus and Candida albicans; downregulating cytokine and microbial protein expression

    Get PDF
    The global escalation in antibiotic resistance cases means alternative antimicrobials are essential. The aim of this study was to investigate the antimicrobial capacity of apple cider vinegar (ACV) against E. coli, S. aureus and C. albicans. The minimum dilution of ACV required for growth inhibition varied for each microbial species. For C. albicans, a 1/2 ACV had the strongest effect, S. aureus, a 1/25 dilution ACV was required, whereas for E-coli cultures, a 1/50 ACV dilution was required (p < 0.05). Monocyte co-culture with microbes alongside ACV resulted in dose dependent downregulation of inflammatory cytokines (TNFα, IL-6). Results are expressed as percentage decreases in cytokine secretion comparing ACV treated with non-ACV treated monocytes cultured with E-coli (TNFα, 99.2%; IL-6, 98%), S. aureus (TNFα, 90%; IL-6, 83%) and C. albicans (TNFα, 83.3%; IL-6, 90.1%) respectively. Proteomic analyses of microbes demonstrated that ACV impaired cell integrity, organelles and protein expression. ACV treatment resulted in an absence in expression of DNA starvation protein, citrate synthase, isocitrate and malate dehydrogenases in E-coli; chaperone protein DNak and ftsz in S. aureus and pyruvate kinase, 6-phosphogluconate dehydrogenase, fructose bisphosphate were among the enzymes absent in C.albican cultures. The results demonstrate ACV has multiple antimicrobial potential with clinical therapeutic implications

    Heparan sulfate disaccharide measurement from biological samples using pre-column derivatization, UPLC-MS and single ion monitoring

    Get PDF
    Glycosaminoglycans are a heterogeneous family of linear polysaccharides comprised of repeating disaccharide subunits that mediate many effects at the cellular level. There is increasing evidence that the nature of these effects is determined by differences in disaccharide composition. However, the determination of GAG disaccharide composition in biological samples remains challenging and time-consuming. We have developed a method that uses derivatization and selected ion recording and RP-UPLCMS resulting in rapid separation and quantification of twelve heparin/heparin sulfate disaccharides from 5 μg GAG. Limits of detection and quantitation were 0.02–0.15 and 0.07–0.31 μg/ml respectively. We have applied this method to the novel analysis of disaccharide levels extracted from heparan sulfate and human cancer cell lines. Heparan sulfate disaccharides extracted from biological samples following actinase and heparinase incubation and derivatized using reductive amination with 2-aminoacridone. Derivatized disaccharides were analyzed used UPLC-MS with single ion monitoring. Eight HS disaccharide subunits were separated and quantified from HS and cell lines in eleven minutes per sample. In all samples the most abundant subunits present were the unsulfated ΔUA-GlcNAc, ΔUA-GlcNAc,6S and ΔUA,2S-GlcNS,6S. There was considerable variation in the proportions and concentrations of disaccharides between different cell lines. Further studies are needed to examine the significance of these differences

    Analysis of procainamide-derivatised heparan sulphate disaccharides in biological samples using hydrophilic interaction liquid chromatography mass spectrometry

    Get PDF
    Glycosaminoglycans (GAGs) are a family of linear heteropolysaccharides made up of repeating disaccharide units that are found on the surface and extracellular matrix of animal cells. They are known to play a critical role in a wide range of cellular processes including proliferation, differentiation and invasion. To elucidate the mechanism of action of these molecules, it is essential to quantify their disaccharide composition. Analytical methods that have been reported involve either chemical or enzymatic depolymerisation of GAGs followed by separation of non-derivatised (native) or derivatised disaccharide subunits and detection by either UV/fluorescence or MS. However, the measurement of these disaccharides is challenging due to their hydrophilic and labile nature. Here we report a pre-column LC-MS method for the quantification of GAG disaccharide subunits. Heparan sulphate (HS) was extracted from cell lines using a combination of molecular weight cutoff and anion exchange spin filters and digested using a mixture of heparinases I, II and III. The resulting subunits were derivatised with procainamide, separated using hydrophilic interaction liquid chromatography and detected using electrospray ionisation operated in positive ion mode. Eight HS disaccharides were separated and detected together with an internal standard. The limit of detection was found to be in the range 0.6–4.9 ng/mL. Analysis of HS extracted from all cell lines tested in this study revealed a significant variation in their composition with the most abundant disaccharide being the non-sulphated ∆UA–GlcNAc. Some structural functional relationships are discussed demonstrating the viability of the pre-column method for studying GAG biolog

    Can quantification of Serum Glycans predict Pre-Eclampsia?

    Get PDF
    Objectives: To determine if concentrations of placental glycans and glycan components are altered in pre-eclamspia and to determine if serum levels can predict pre-eclampsia. Methods: Serum samples were collected from women in the third trimester of singleton pregnancy but before the onset of pre-eclampsia and also from women during unaffected pregnancies at the samegestational age. Tissues were collected from the basal plate of placentas collected at delivery following uncomplicated singleton pregnancy (term and preterm) and from pregnancies complicated by preeclampsia. Pre-eclampsia was diagnosed according to International Society for the Study of Hypertension in Pregnancy criteria. Glycan components were isolated using a combination of enzyme digestion, molecular weight filtration and ion exchange chromatography, and then derivatised prior to separation using hydrophilic interaction liquid chromatography. Components were detected using electrospray ionisation operated in positive ion mode with single ion monitoring. Results: Specific glycan components (designated glycan 1, 2 and 3) were significantly altered in the serum from women who went on to have preeclampsia compared to those who had an unaffected pregnancy. Interestingly, levels of the same biomarkers were also elevated in nulliparous versus multiparous pregnancy. Biomarkers were also significantly altered in placental tissues from pregnancies complicated by preeclampsia Conclusion: This study suggests that altered glycan levels may contribute to impaired placental development and that the glycome is a potential diagnostic target for pre-eclampsia, and possibly other disorders of pregnancy

    Case Histories of Soil Behaviour and Investigations for Seismically Distressed Earthen Dams of Kachchh Region in Gujarat, India

    Get PDF
    In the morning of January 26, 2001, a devastating earthquake of magnitude Mw 7.7 rocked the Gujarat State of India. The disastrous earthquake claimed thousands of human lives besides widespread destruction of the properties including damages to water resources projects of Kachchh region. This worst ever natural calamity of recent time posed challenging and daunting task of restoration and reconstruction works. A committee of experts was constituted by Government of Gujarat with a view to assess the damages occurred to the dams & other appurtenant structures and to recommend restoration and reconstruction works. Consequent to the event, dams of Kachchh region situated within radius of 200 km from the epicenter were inspected as per the guidelines of International Commission On Large Dams (ICOLD). Integrated geotechnical investigation program comprising soil exploration and laboratory testing was chalked out to determine the properties of foundation & embankment soils. The paper describes the seismic data on Bhuj Earthquake, geology of Kachchh region, geotechnical investigation including assessment of liquefaction potential and their considerations in the restoration measures of two earth dams
    • …
    corecore