3,029 research outputs found

    Architecture for public safety network using D2D communication

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    Device to Device (D2D) communication has been proposed as an underlay to Long-Term evolution (LTE) network as a means of harvesting the proximity, reuse and hop gains. However, D2D communication can also serve as a technology for providing public safety and disaster relief services. In this article, the basic concepts of D2D communications are first introduced and then existing fundamental works on disaster communication are discussed. We focus on the performance of the network architecture by utilizing the relay assisted transmission which can effectively enhance the capacity and power saving of the network. We also propose the distance based strategy to reduce the computational complexity and power transmission. Finally, simulation results are provided to verify the proposed architecture

    Security aspects of communications in VANETs

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    The Fourth Industrial Revolution has begun and it promises breakthroughs in Artificial Intelligence, robotics, Machine Learning, Internet of Things, Digital Twin, and many other technologies that tackle advancements in the industries. The trend is headed towards automation and connectivity. In the automotive industry, advancements have been made towards integrating autonomous driving vehicles into Intelligent Transport Systems (ITS) with the use of Vehicular Ad-Hoc Networks (VANETs). The purpose of this type of network is to enable efficient communication between vehicles (V2V communication) or vehicles and infrastructure (V2I communication), to improve driving safety, to avoid traffic congestion, and to better coordinate transport networks. This direction towards limited (or lack of) human intervention implies vulnerability to cyber attacks. In this context, this paper provides a comprehensive classification of related state-of-the-art approaches following three key directions: 1) privacy, 2) authentication and 3) message integrity within VANETs. Discussions, challenges and open issues faced by the current and next generation of vehicular networks are also provided

    Sizing HESS as inertial and primary frequency reserve in low inertia power system

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    Energy storage systems are recognised as the potential solution to alleviate the impacts of reduced inertia and intermittency in power systems due to the integration of renewable energy sources. Several energy storage technologies are available in the market with diverse power and energy characteristics, operational limitations, and costs. Besides, frequency regulations in power systems have different requirements, for example, inertial response requires high power for a short period while primary frequency regulation requires steady power for a longer time. Thus, it is crucial to find out the optimum sizes and types of storage technologies for these services. In this paper, a methodology for sizing fast responsive energy storage technologies for inertial response, primary frequency regulation, and both inertial response and primary frequency regulation is developed. The sizing of storage systems for inertial response, primary frequency regulation, and both inertial response and primary frequency regulation is done separately. The sizing of storage for inertial response is done in two steps. A region reduction iterative algorithm is proposed to estimate the storage size for inertial response. The sizing of the storage system for primary frequency regulation is done analytically. The sizing methodology incorporates the frequency dynamics of storage, converters, and other associated controls that affect the frequency response. Moreover, an economic analysis is carried out to find the optimum combination of storage technologies for inertial response, primary frequency regulation, and both inertial response and primary frequency regulation services. The accuracy of the proposed sizing method has been compared with the metaheuristic algorithm based technique. The effectiveness of the proposed method is also compared with those in the literature. Simulation results show that the proposed method outperforms the existing methods in the literature. Finally, the non‐linear simulations revealed the validity of the optimal solutions

    MULTI-HAZARD RISK ASSESSMENT OF QURUMBAR VALLEY, GHIZER, GILGIT BALTISTAN, PAKISTAN

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    Being located in a seismically active zone, these mountain valleys are exposed to different hydro-meteorological hazards like rockfall, debris flow, landslide, ice avalanches, and glacial lake outburst flood (GLOFs).  The present study is to investigate different multi-hazards and their prevailing risk in the particular area of Qurumbar valley Ishkoman. In the mid-nineteen and twenty centuries at least six devastating glacial lake outburst floods (GLOFs) has been recorded, initially, only the Qurumbar glacier was considered as the main cause of this outburst flood, later field investigation and interview from local inhabitant revealed that nine more tributary glacier are existing in the area. The recent outburst of flood in the Badswat area of Qurumbar Ishkoman is also considerable, submerging 12 houses and a stretch of roads. Apart from it, the physical vulnerability of the area is increasing, as new areas are being used for housing with the increase in population. The study area is exposed to several other natural hazards like rock fall, debris flows, ice avalanches, and bank erosion. The present study is based on quantitative and qualitative approaches in assistance with GIS/RS an emergent application. The following methodologies were adapted to gather the primary and secondary data for GIS/RS processing. The primary data comprises GIS data and procurement and development and field data. The field data contain ground-truthing /validation. The community-based Hazard Vulnerability Risk Assessment (HVRA) was also carried out to know about human perception. Secondary data has been collected from different literature. Both the data were put into GIS for the processing which gives us our final developmental tools in the form of maps. The hazard and risk map of the Qurumbar Ishkoman depict that flash floods, debris flow, bank erosion, and GLOFs account for major hazards in Qurumbar valley. It is concluded based on our outcomes i.e., hazard and risk maps that earthquake is the main hazard of the area while flash floods, GLOFs, debris flow, bank erosion and the bank collapsed are the main hazards of the area. It is very important to systematically integrate map information into the planning and management process which contributes to a safer environment

    Preliminary Phytochemical Screening and Antispasmodic Activity of Artemisia macrocephala Jacquem

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    The current work describes the antispasmodic action of Artemisia macrocephala, which is achieved via blocking of the calcium channels. This explains its traditional use as an antispasmodic.The crude methanolic extract of A. macrocephala was studied for possible relaxant effect(s) on spontaneous rabbits’ jejunum preparations. Analytical-grade chemicals were used in the experimental protocols. A. macrocephala gave positive tests for flavonoids, saponins, glycosides, alkaloids, and terpenes. A. macrocephala caused relaxation of spontaneous rabbits’ jejunum preparations (n=6) at a dose of 10.0 mg/mL (EC50 = 6.95 ± 0.20 mg/mL; 95% CI: 6.2 to 7.5). Contractions induced by 80 mM potassium chloride (KCl) were also relaxed by the A. macrocephala at dose of 10.0 mg/mL. Attempting to find an explanation for the possible mode of action, we found that, A. macrocephala at concentration of 1.0 mg/mL produced rightward shift in the calcium chloride curves, with EC50 value of –1.65 ± 0.02 log [Ca++] M vs control with EC50 value of –2.44 ± 0.043 for calcium chloride curves. At a concentration of 1.0 mg/mL it could produce 52.4% of the control response at log [Ca++] M = –1.6. Similarly, verapamil at a concentration of 0.1 μM produced a rightward shift, with EC50 value of –1.74 ± 0.026 log [Ca++] M (95% CI: –1.66 to –1.82; n=6) vs control with EC50 value of –2.45 ± 0.05 log [Ca++] M (95% CI: – 2.23 to –2.91; n=6). The right shift of the EC50 values is justification for the folkloric use of A. macrocephala as an antispasmodic, suggesting that the possible mode of action is through calcium channel blockade

    Localizing introgression on the chromosome of rice by genomic in situ hybridization (GISH)

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    Genomic in situ hybridization was used to detect introgressed segment from Oryza australinesis onto the chromosomes of introgression line derived from the hybrid O. sativa x O. australinesis. Genomic DNA from Oryza australinesis was labeled with biotin and hybridized to the homologous sequences on the O. sativa chromosomes. The probe hybridization fluoresced green and non labeled O. sativa chromosomes appeared red or blue due to counterstaining with propidium iodide (PI) or 4,6-diamidino-2-phenylindole (DAPI). This differential painting of chromosomes unequivocally detected the introgressedsegment. Among the 200 cells analyzed, 6.5% of the cells showed  hybridization signal. Signal appeared on one chromosome in 5%, on two homologous chromosomes in 1% and on sister chromatids in 0.5%of the cells. Hybridization was seen on the short arm of the chromosome 12 of the introgression line

    Preliminary Phytochemical Screening and Antispasmodic Activity of Artemisia macrocephala Jacquem

    Get PDF
    The current work describes the antispasmodic action of Artemisia macrocephala, which is achieved via blocking of the calcium channels. This explains its traditional use as an antispasmodic.The crude methanolic extract of A. macrocephala was studied for possible relaxant effect(s) on spontaneous rabbits’ jejunum preparations. Analytical-grade chemicals were used in the experimental protocols. A. macrocephala gave positive tests for flavonoids, saponins, glycosides, alkaloids, and terpenes. A. macrocephala caused relaxation of spontaneous rabbits’ jejunum preparations (n=6) at a dose of 10.0 mg/mL (EC50 = 6.95 ± 0.20 mg/mL; 95% CI: 6.2 to 7.5). Contractions induced by 80 mM potassium chloride (KCl) were also relaxed by the A. macrocephala at dose of 10.0 mg/mL. Attempting to find an explanation for the possible mode of action, we found that, A. macrocephala at concentration of 1.0 mg/mL produced rightward shift in the calcium chloride curves, with EC50 value of –1.65 ± 0.02 log [Ca++] M vs control with EC50 value of –2.44 ± 0.043 for calcium chloride curves. At a concentration of 1.0 mg/mL it could produce 52.4% of the control response at log [Ca++] M = –1.6. Similarly, verapamil at a concentration of 0.1 μM produced a rightward shift, with EC50 value of –1.74 ± 0.026 log [Ca++] M (95% CI: –1.66 to –1.82; n=6) vs control with EC50 value of –2.45 ± 0.05 log [Ca++] M (95% CI: – 2.23 to –2.91; n=6). The right shift of the EC50 values is justification for the folkloric use of A. macrocephala as an antispasmodic, suggesting that the possible mode of action is through calcium channel blockade

    Dvopulsni sustav za isporuku amoksicilina: Pokušaj sprečavanja bakterijske rezistencije na antibiotike

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    Bearing in mind the present scenario of the increasing biological tolerance of bacteria against antibiotics, a time controlled two pulse dosage form of amoxicillin was developed. The compression coating inlay tablet approach was used to deliver the drug in two pulses to different parts of the GIT after a well defined lag time between the two releases. This was made possible by formulating a core containing one of the two drug fractions (intended to be delivered as the second pulse), which was spray coated with a suspension of ethyl cellulose and a hydrophilic but water insoluble agent as a pore former (microcrystalline cellulose). Coating of 1 up to 5 % (m/m) was applied over the core tablet, giving a corresponding lag of 3, 5, 7 and 12 h. Increasing the level of coating led to retardation of the water uptake capacity of the core, leading to prolongation of the lag time. Microcrystalline cellulose was used as a hydrophilic but water insoluble porosity modifier in the barrier layer, varying the concentration of which had a significant effect on shortening or prolongation of the lag time. This coated system was further partially compression coated with the remaining drug fraction (to be released as the first immediate release pulse) with a disintegrant, giving a final tablet. The core tablet and the final two pulse inlay tablet were further investigated for the in vitro performance.Zbog sve učestalije pojave rezistencije bakterija na antibiotike, razvijen je dvopulsni sustav s vremenskom kontrolom za isporuku amoksicilina. Sustav čine slojevite tablete s obloženim slojem dobivenim metodom kompresije, koji omogućavaju isporuku lijeka u dva pulsa u različite dijelove gastrointestinalnog trakta, s utvrđenom odgodom između dva oslobađanja. Ovakav način oslobađanja postignut je s pripravkom koji u jezgri tablete sadrži jednu frakciju lijeka (koja se oslobađa kao drugi puls), a u oblozi drugu. Obloženi dio dobiven je sprejanjem sa suspenzijom etilceluloze i hidrofilnog, ali vodonetopljivog sredstva koji tvori pore (mikrokristalinična celuloza). Oblaganje sa slojem koji čini 1 do 5 % (m/m) mase jezgre postignut je vremenski odmak drugog pulsa od 3, 5, 7 i 12 h. Povećanjem mase obložnog sloja smanjuje se kapacitet prodiranja vode u jezgru tablete, što produljuje vrijeme drugog pulsa. Mikrokristalinična celuloza uporijebljena je kao hidrofilno, vodonetopljivo sredstvo za kotrolu poroznosti u barijernom sloju. Promjena koncentracije celuloze značajno je utjecala na skraćenje ili produljenje vremenskog odmaka. Obloženi sustav je potom djelomično obložen s preostalom frakcijom lijeka (koja se oslobađa odmah u prvom pulsu) pomiješanom s dezintegratorom. Tableta s jezgrom i dvopulsna slojevita tableta ispitivane su in vitro

    Toxin inhibition in <i>C. crescentus</i> VapBC1 is mediated by a flexible pseudo-palindromic protein motif and modulated by DNA binding

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    Expression of bacterial type II toxin-antitoxin (TA) systems is regulated at the transcriptional level through direct binding of the antitoxin to pseudo-palindromic sequences on operator DNA. In this context, the toxin functions as a co-repressor by stimulating DNA binding through direct interaction with the antitoxin. Here, we determine crystal structures of the complete 90 kDa heterooctameric VapBC1 complex from Caulobacter crescentus CB15 both in isolation and bound to its cognate DNA operator sequence at 1.6 and 2.7 Å resolution, respectively. DNA binding is associated with a dramatic architectural rearrangement of conserved TA interactions in which C-terminal extended structures of the antitoxin VapB1 swap positions to interlock the complex in the DNA-bound state. We further show that a pseudo-palindromic protein sequence in the antitoxin is responsible for this interaction and required for binding and inactivation of the VapC1 toxin dimer. Sequence analysis of 4127 orthologous VapB sequences reveals that such palindromic protein sequences are widespread and unique to bacterial and archaeal VapB antitoxins suggesting a general principle governing regulation of VapBC TA systems. Finally, a structure of C-terminally truncated VapB1 bound to VapC1 reveals discrete states of the TA interaction that suggest a structural basis for toxin activation in vivo
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