7 research outputs found
Market Driven Multi-domain Network Service Orchestration in 5G Networks
The advent of a new breed of enhanced multimedia services has put network
operators into a position where they must support innovative services while
ensuring both end-to-end Quality of Service requirements and profitability.
Recently, Network Function Virtualization (NFV) has been touted as a
cost-effective underlying technology in 5G networks to efficiently provision
novel services. These NFV-based services have been increasingly associated with
multi-domain networks. However, several orchestration issues, linked to
cross-domain interactions and emphasized by the heterogeneity of underlying
technologies and administrative authorities, present an important challenge. In
this paper, we tackle the cross-domain interaction issue by proposing an
intelligent and profitable auction-based approach to allow inter-domains
resource allocation
High resolution melting: a useful field-deployable method to measure dhfr and dhps drug resistance in both highly and lowly endemic Plasmodium populations
Background: Emergence and spread of drug resistance to every anti-malarial used to date, creates an urgent need for development of sensitive, specifc and feld-deployable molecular tools for detection and surveillance of validated drug resistance markers. Such tools would allow early detection of mutations in resistance loci. The aim of this study was to compare common population signatures and drug resistance marker frequencies between two populations with diferent levels of malaria endemicity and history of anti-malarial drug use: Tanzania and SĂ©nĂ©gal. This was accomplished by implementing a high resolution melting assay to study molecular markers of drug resistance as compared to polymerase chain reactionârestriction fragment length polymorphism (PCR/RFLP) methodology.
Methods: Fifty blood samples were collected each from a lowly malaria endemic site (SĂ©nĂ©gal), and a highly malaria endemic site (Tanzania) from patients presenting with uncomplicated Plasmodium falciparum malaria at clinic. Data representing the DHFR were derived using both PCRâRFLP and HRM assay; while genotyping data representing the DHPS were evaluated in Senegal and Tanzania using HRM. Msp genotyping analysis was used to characterize the multiplicity of infection in both countries.
Results: A high prevalence of samples harbouring mutant DHFR alleles was observed in both population using both genotyping techniques. HRM was better able to detect mixed alleles compared to PCR/RFLP for DHFR codon 51 in Tanzania; and only HRM was able to detect mixed infections from Senegal. A high prevalence of mutant alleles in DHFR (codons 51, 59, 108) and DHPS (codon 437) were found among samples from Sénégal while no mutations were observed at DHPS codons 540 and 581, from both countries. Overall, the frequency of samples harbouring either a single DHFR mutation (S108N) or double mutation in DHFR (C59R/S108N) was greater in Sénégal compared to Tanzania
Conclusion: Here the results demonstrate that HRM is a rapid, sensitive, and feld-deployable alternative technique to PCRâRFLP genotyping that is useful in populations harbouring more than one parasite genome (polygenomic infections). In this study, a high levels of resistance polymorphisms was observed in both dhfr and dhps, among samples from Tanzania and SĂ©nĂ©gal. A routine monitoring by molecular markers can be a way to detect emergence of resistance involving a change in the treatment policy
PCPV: Pattern-based Cost-efficient Proactive VNF placement and chaining for value-added services in content delivery networks
International audienceValue-added services (VASs) are an integral part of todays Content Delivery Networks (CDNs). They can be implemented as a chain of Virtual Network Functions (VNFs). These chains need to be placed in an efficient way in CDNs in order to optimize quality of service (QoS) for end-users(EUs) while minimizing cost for providers. We formulate the problem as an Integer Linear Program (ILP) and propose a Pattern-based Cost-efficient Proactive VNF placement and chaining (PCPV) algorithm. The objective is to find the optimal number, location and chaining of VNFs in such a manner that the cost is minimized while QoS is met. Apart from cost minimization, the support for large-scale CDNs with a large number of physical machines (servers) and EUs is an important feature of the proposed algorithm. Through simulations, the algorithm behavior for small-scale to large scale CDN networks is analyzed
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Selection of N86F184D1246 haplotype of Pfmrd1 gene by artemetherâlumefantrine drug pressure on Plasmodium falciparum populations in Senegal
Background: The use of artemisinin as a monotherapy resulted in the emergence of artemisinin resistance in 2005 in Southeast Asia. Monitoring of artemisinin combination therapy (ACT) is critical in order to detect and prevent the spread of resistance in endemic areas. Ex vivo studies and genotyping of molecular markers of resistance can be used as part of this routine monitoring strategy. One gene that has been associated in some ACT partner drug resistance is the Plasmodium falciparum multidrug resistance protein 1 (pfmdr1) gene. The purpose of this study was to assess the drug susceptibility of P. falciparum populations from ThiĂšs, Senegal by ex vivo assay and typing molecular markers of resistance to drug components of ACT currently used for treatment. Methods: The ex vivo susceptibility of 170 P. falciparum isolates to chloroquine, amodiaquine, lumefantrine, artesunate, and artemether was determined using the DAPI ex vivo assay. The high resolution melting technique was used to genotype the pfmdr1 gene at codons 86, 184 and 1246. Results: A significant decrease in IC50 values was observed between 2012 and 2013: from 13.84 to 6.484 for amodiaquine, 173.4 to 113.2 for lumefantrine, and 39.72 to 18.29 for chloroquine, respectively. Increase of the wild haplotype NYD and the decrease of the mutant haplotype NFD (79 and 62.26 %) was also observed. A correlation was observed between the wild type allele Y184 in pfmdr1 and higher IC50 for all drugs, except amodiaquine. Conclusion: This study has shown an increase in sensitivity over the span of two transmission seasons, marked by an increase in the WT alleles at pfmdr1. Continuous the monitoring of the ACT used for treatment of uncomplicated malaria will be helpful