2,107 research outputs found

    A review and comparison of efficient flooding schemes for on-demand routing protocols on mobile ad hoc networks (MANETs)

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    Since the basic components of ad hoc wireless networks are mostly battery-operated portable devices, power conservation is one of the central issues of such networks. Power-conservative designs for ad hoc networks pose many challenges due to the lack of central coordination facilities. Existing on-demand routing protocols perform route discovery by flooding the network with a query message requesting a route to the destination. Flooding is used because of its simplicity and greater success in finding the best route between the source and destination available at that time of route discovery. However, as flooding involves querying all reachable network nodes, frequent flooding can rapidly deplete the energy reserved at each node. In addition to consuming significant portions of the available network bandwidth. Further, as the number of communicating nodes increases, more congestion, contention, and collisions can be expected. This paper reviews and compares approaches for optimizing bandwidth efficiency of route discovery, where several efficient flooding schemes have been presented based on different techniques to solve the problems related with the traditional blind flooding

    IN SILICO INVESTIGATION OF PHYTOCONSTITUENTS FROM VARIOUS PLANTS AGAINST NEUROINFLAMMATORY MARKERS AS POTENT THERAPEUTIC TARGETS

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    Abstract Objective: Neuroinflammation is inflammation of the brain and brain tissue. Activation of glial cells (Microgila and astrocytes) takes place during neuroinflammation, due to which a number of inflammatory mediator release in the brain. The objective of the current study is to investigate the anti-neuroinflammatory activity of the phytoconstituents against various inflammatory mediators.Methods: The preliminary screening of plants was done by Lipinski's rule of five. Inflammatory mediators (COX-1, COX-2, TNF-a, IL-1b, iNOS and   nNOS) protein sequence was retrieved from STRING database and modeling of it through SWISS MODEL. And ligands ID was retrieved from ZINC database and its MOL2 format was downloaded for further processing. Docking study of phytoconstituents with ligands were performed by iGEMDOCK. By using ADMET, Absorption, distribution, metabolism, excretion and toxicity properties were predicted.Results: Sissotrin out of the various phytocomponents is the most active component having high binding affinity with all the genes.Conclusion: Sissotrin may be a good inhibitor for neuroinflammatory disorders

    Kinetics of the electropolymerization of aminoanthraquinone from aqueous solutions and analytical applications of the polymer film

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    AbstractPoly 1-amino-9, 10-anthraquinone (PAAQ) films were prepared by the electropolymerization of 1-amino-9,10-anthraquinone (AAQ) on platinum substrate from aqueous media, where 5.0×10−3molL−1 AAQ and 6.0molL−1 H2SO4 were used. The kinetics of the electropolymerization process was investigated by determining the change of the charge consumed during the polymerization process with time at different concentrations of both monomer and electrolyte. The results have shown that the process follows first order kinetics with respect to the monomer concentration. The order of the reaction with respect to the aqueous solvent i.e. H2SO4 was found to be negative. The polymer films were successfully used as sensors for the electroanalytical determination of many hazardous compounds, e.g. phenols, and biologically important materials like dopamine. The electroanalytical determination was based on the measurements of the oxidation current peak of the material in the cyclic voltammetric measurements. The cyclic voltammograms were recorded at a scan rate of 100mVs−1 and different analyte concentrations. A calibration curve was constructed for each analyte, from which the determination of low concentrations of catechol and hydroquinone (HQ) as examples of hazardous compounds present in waste water and also for ascorbic acid and dopamine as examples of valuable biological materials can be achieved

    The Effect of Power factor Improvement on Switching Transients: A Case of FUMMAN Agricultural Products Industry Plc.

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    Industrial loads are mostly inductive and hence operate at low power factor. Several methods including the installation of capacitor banks are available for improving power factor in order to reduce the kilovolt ampere (kVA) demand of the load and power loss from the power supply system. However, literatures have shown that improvement of power factor has effect on switching transients which is dangerous for industrial loads and operating personnel. In this work, we investigated the effect of improving the power factor of a power system beyond 0.8 (lagging) on switching transient levels using FUMMAN industry power network as a case study. A power factor measuring tool was modelled using the mathematical relation between power factor, reactive power and active power. The modelled equations were simulated Matlab/Simulink software (Version 7.9.0.529 ‘R2009b’). The characteristics of the system under study namely root mean square (r.m.s) voltage, peak steady state voltage, peak transient voltage and kVA demand were measured during the simulation with and without parallel connection of capacitor bank across the system. The result from the analysis showed that FUMMAN industry power network was operating at a lagging power factor of 0.8 with r.m.s voltage of 412.1 V, peak steady state voltage of 582.8 V, peak transient voltage of 701.9 V and kVA demand of 1878 kVA without the capacitor bank. However, when a capacitor bank was connected across the system and the power factor increased from 0.8 (lagging) to 0.9098 (lagging), optimised performance of the system was obtained with a capacitor bank size of 440 kVar. At lagging power factor of 0.9098, the kVA demand of the system was 1650 kVA, r.m.s voltage was 415.5 V and peak transient voltage was 749.5 V. The analysis therefore showed that increasing power factor beyond 0.8 (lagging) using capacitor banks though improves the r.m.s voltage and reduces the power loss but invariably leads to increase in switching transients which is undesired for optimised system performance

    Evaluation of anticancer activity of Debregeasia Salicifolia extract against estrogen receptor positive cell line

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    Crude methanol extract and fractions of Debregeasia salicifolia stem were examined for their anticancer activity. To determine anticancer activity, different concentrations of crude extract were tested on MCF- 7 cancer cell line by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. D. salicifolia extract showed a significant antiproliferative activity and a dose dependent effect was observed. Minimum inhibition of 25.31% was shown by extract at concentration 10 ìg/ml and maximuminhibition (99%) was observed at 500 ìg/ml. Hexane, chloroform, ethyl acetate, methanol and aqueous fractions were also tested at a  concentration of 200 ìg/ml. Hexane, chloroform and ethyl acetatefractions appeared to be most active with 90 to 99% activity. These results indicate the possible potential use of D. salicifolia as antineoplastic agent. Preliminary phytochemical screening revealed the chemical composition of D. salicifolia extract containing flavonoids, anthraquinones and tannins.Anticancer properties of D. salicifolia can be linked with the presence of these chemicals.Key words: Anticancer, cytotoxic, Debregeasia salicifolia, MCF-7 cell line, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, phytochemical

    Prevalence and Classification of Amphistomes in Cattle and Buffaloes

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    Amphistomes are snail-borne trematodes infect rumens and reticulums capable of causing acute and chronic disease in cattle and buffaloes. A total of 897 of cattle and buffaloes were examined by faecal examinations and by postmortem examinations in Giza and Garbia governourates. The collected Amphistomes were morphologically and histologically classified. We found that the incidence of Amphistomes in totally examined animals was 4.9%. The incidence was higher in the oldest animals(than young), in the spring (than other seasons) and in Garbia (than Giza). But the incidence was the same in males and females. The collected Amphistomes were classified as Paramphistomum microbothrium, Paramphistomum cervi and Carmyerius gergaerius. We concluded that Amphistomes are prevalent among the examined cattle and buffaloes in Giza and Garbia governorates.

    Dual-acting stapled peptides target both HIV-1 entry and assembly

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    Background: Previously, we reported the conversion of the 12-mer linear and cell-impermeable peptide CAI to a cell-penetrating peptide NYAD-1 by using an i,i + 4 hydrocarbon stapling technique and confirmed its binding to the C-terminal domain (CTD) of the HIV-1 capsid (CA) protein with an improved affinity (Kd ~ 1 μM) compared to CAI (Kd ~ 15 μM). NYAD-1 disrupts the formation of both immature- and mature-like virus particles in in vitro and cell-based assembly assays. In addition, it displays potent anti-HIV-1 activity in cell culture against a range of laboratory-adapted and primary HIV-1 isolates.<p></p> Results: In this report, we expanded the study to i,i + 7 hydrocarbon-stapled peptides to delineate their mechanism of action and antiviral activity. We identified three potent inhibitors, NYAD-36, -66 and -67, which showed strong binding to CA in NMR and isothermal titration calorimetry (ITC) studies and disrupted the formation of mature-like particles. They showed typical α-helical structures and penetrated cells; however, the cell penetration was not as efficient as observed with the i,i + 4 peptides. Unlike NYAD-1, the i,i + 7 peptides did not have any effect on virus release; however, they impaired Gag precursor processing. HIV-1 particles produced in the presence of these peptides displayed impaired infectivity. Consistent with an effect on virus entry, selection for viral resistance led to the emergence of two mutations in the gp120 subunit of the viral envelope (Env) glycoprotein, V120Q and A327P, located in the conserved region 1 (C1) and the base of the V3 loop, respectively.<p></p> Conclusion: The i,i + 7 stapled peptides derived from CAI unexpectedly target both CA and the V3 loop of gp120. This dual-targeted activity is dependent on their ability to penetrate cells as well as their net charge. This mechanistic revelation will be useful in further modifying these peptides as potent anti-HIV-1 agents.<p></p&gt

    Continuous quality assessment; development of a simple computer based model for audit

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    Objective: Accurate assessment of quality of care is a fundamental first step in the process of quality improvement. The vast amount of data generated in a hospital mandates some form of computerization for management of information. We describe a locally developed simple computer based program to access relevant information from a hospital patient management network. The objective was to reduce the amount of manual work involved for busy clinicians attempting to audit quality of care.Methods: A single surgical procedure, Laparoscopic Cholecystectomy was chosen. Quality indicators were identified by literature review as conversion rate from laparoscopic to open cholecystectomy and length of hospital stay (LOS). A simple query was developed to extract the required information from hospital database. Commercially available spreadsheet software (Microsoft Excel) was used to calculate the rates. Outliers were defined as LOS more than 1 standard deviation from the mean. The second part of the study involved a manual review of case notes to validate the program and determine the causes for deviation from the mean.Results: The program was able to access and process data as planned. In a one-year period from March 1997 to February 1998, two hundred and thirty one laparoscopic cholecystectomies were attempted. Twenty-three were converted to open procedures given a conversion rate of 9.96%. On manual review of case notes no false positives or false negatives were found. The reasons for conversion were similar to those described in the literature. The mean length of stay for laparoscopic cholecystectomy was 3.39 days and 7.17 days for converted cases. The commonest reason for delay in discharge was noted to be non-availability of elective operating time.CONCLUSION: We have successfully developed and used a simple computer based program to access information stored in hospital patient management systems. Quality of care indicators identified from literature were used as standards. Outliers with respect to these were reviewed in detail to identify causes for deviation. The program was validated by manual review

    Wettability of Al2O3 by Aluminum and Al-Mg Alloys

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    The wettablity at a liquid of pure-Al or Al-Mg alloys/ Al2O3 interface wasevaluated by the sessile drop method at 700oC and with a vacuum pressure of10-4Pa. The value of contact angle varies (decreases) with time of contact withAl2O3 substrate. The reduction in θ of the Al-Mg alloy was proportional to thereduction in surface tension γlv of Al, and to reactions that took place at the Alalloy/Al2O3 interface

    Videoconference-based creativity workshops for mental health staff during the COVID-19 pandemic

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    Background COVID-19 presented significant challenges to psychiatric staff, while social distancing and remote working necessitated digital communications. NHS England prioritised staff wellbeing. Arts-based creativity interventions appear to improve psychological wellbeing, so this study evaluated online Creativity Workshops as a staff support response for COVID-19-related stress. Methods Participants were staff from a South London NHS psychiatric hospital. Group Creativity Workshops were facilitated via Microsoft Teams. Acceptability data on pre- and post-workshop mood and attitudes were self-reported by participants. Feasibility data were gathered from adherence to number of workshop components delivered. Results Eight workshops were delivered in May-September 2020 (N = 55) with high adherence to components. Participants reported significantly increased positive mood and attitudes towards themselves and others; and decreased stress and anxiety. Conclusions Online Creativity Workshops appear feasible and acceptable in reducing stress in psychiatric staff. Integrating a programme of Creativity Workshops within healthcare staff support may benefit staff wellbeing
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