Recent advances in collaborative information and empathic communication do not necessar-ily obviate the need for active networks. After years of confirmed research into telephony, we prove the ...synthesis of local-area networks. Our focus in this paper is not on whether the seminal lossless algorithm for the deployment of IPv4 by Suzuki is maximally efficient, but rather on presenting new compact symmetries (Subway).
The Domain Name System (DNS), which converts domain names to IP addresses, is a critical component of the internet infrastructure. Attackers exploit the existing potential vulnerabilities in this ...network protocol to launch their attacks. Distributed Reflection Denial of Service (DRDoS) DN S attacks are a type of Distributed Denial of Service (DDoS) attack that uses DNS vulnerabilities to carry out their attacks. These types can rapidly deplete the resources of the targeted victim system (computational and bandwidth). With the advancement of attack methods, both quantitatively and qualitatively, traditional methods used to detect DNS threats, particularly DRDoS attacks, became ineffective. Therefore, in this paper, a new model called proactive feature selection model PFS for early detection of DRDoS attacks based on DNS responses. The PFS model is divided into two stages: features selection stage and detection DRDoS attacks stage. The PFS model was validated using the standard CICDDoS2019 dataset. The results show that the PFS model achieves a high accuracy of 91.4368% and a very low FPR while reducing the number of features from 88 to 19 in the standard CICDDoS2019 dataset.
The evaporation of an oscillating droplet has been investigated numerically by using the in-house code FS3D (Free Surface 3D), which is used for direct numerical simulations (DNS) of incompressible ...multi-phase flows. Validations of the numerical simulations have been shown for two cases. The numerical results have been discussed e.g. for the surface evaporation flux, which depends on location and time. This has been the first time that such DNS calculations have been done for the evaporation of a free-oscillating droplet. It could be shown that the evaporation flux for the unsteady conditions differs strongly from the one predicted with a simplified model assuming quasi-steady conditions, up to 30%. This difference may be caused by the moving interface under unsteady conditions. Thus, it is not possible to describe the problem under investigation with available simple models which use the assumption of quasi-steadiness of the process.
•The evaporation of an oscillating droplet is investigated by 3D DNS.•The quasi-steady assumption is released.•The simple model using the quasi-steady assumption is unavailable for our work.•The distribution of evaporation flux is independent of the droplet shape.•The evaporation flux is elevated at the poles and the equator.
•Peptide Nucleic Acids − DNA/RNA analogues.•Different Modifications on PNA backbone and their effects.•Neutral backbone − remarkable hybridization properties.•PNA based biosensors and their diverse ...biomedical applications.•Potential antigene and antisense agents.
Peptide Nucleic Acids (PNAs) are the DNA/RNA analogues in which sugar-phosphate backbone is replaced by N-2-aminoethylglycine repeating units. PNA contains neutral backbone hence due to the absence of electrostatic repulsion, its hybridization shows remarkable stability towards complementary oligonucleotides. PNAs are highly resistant to cleavage by chemicals and enzymes due to the substrate specific nature of enzymes and therefore not degraded inside the cells. PNAs are emerging as new tools in the market due to their applications in antisense and antigene therapies by inhibiting translation and transcription respectively. Hence, several methods based on PNAs have been developed for designing various anticancer and antigene drugs, detection of mutations or modulation of PCR reactions. The duplex homopurine sequence of DNA may also be recognized by PNA, forming firm PNA/DNA/PNA triplex through strand invasion with a looped-out DNA strand. PNAs have also been found to replace DNA probes in varied investigative purposes. There are several disadvantages regarding cellular uptake of PNA, so modifications in PNA backbone or covalent coupling with cell penetrating peptides is necessary to improve its delivery inside the cells. In this review, hybridization properties along with potential applications of PNA in the field of diagnostics and pharmaceuticals are elaborated.
Abstract
The exponential growth of IoT devices and their need to use IPv6 addresses has the potential to create load stress on the existing DNS infrastructure and it is imperative that DNS servers to ...be deployed on IPv6 networks. The DNS query latency from a particular Internet vantage point for IPv4 and IPv6 network cannot be compared directly due to variations in the number of hops of query on IPv4 and IPv6 communication networks. Moreover, there is no assurance that DNS server in the hierarchy is hosted on a dual-stack. This work brings out the DNS query resolution latency over the IPv4 and IPv6 protocol stacks with better accuracy. The experiments are carried out by setting up a complete DNS hierarchy (ROOT, TLD, STLD, TTLD and recursive resolver) on dual IP stack (IPv4 and IPv6), enabling both forward and reverse lookup tree on a live testbed, ensuring a constant number of hops between the recursive resolver and each of the DNS servers in the hierarchy. This live testbed is a first of its kind and is made available for Internet researchers. The operational issues encountered during this deployment and service provisioning are discussed and documented in this paper. This paper also gives a clear illustration and provides reference guidelines for the DNS hierarchy setup, and also aims to bridge the knowledge gap required for deploying DNS over IPv6.
Three sets of 7‐deazaadenine and cytosine nucleosides and nucleoside triphosphates bearing either unsubstituted ferrocene, octamethylferrocene and ferrocenecarboxamide linked through an alkyne tether ...to position 7 or 5, respectively, were designed and synthesized. The modified dNFcXTPs were good substrates for KOD XL DNA polymerase in primer extension and were used for enzymatic synthesis of redox‐labelled DNA probes. Square‐wave voltammetry showed that the octamethylferrocene oxidation potential was shifted to lower values, whilst the ferrocenecarboxamide was shifted to higher potentials, as compared to ferrocene. Tailed PEX products containing different ratios of Fc‐labelled A (dAFc) and FcPa‐labelled C (dCFcPa) were synthesized and hybridized with capture oligonucleotides immobilized on gold electrodes to study the electrochemistry of the redox‐labelled DNA. Clearly distinguishable, fully orthogonal and ratiometric peaks were observed for the dAFc and dCFcPa bases in DNA, demonstrating their potential for use in redox coding of nucleobases and for the direct electrochemical measurement of the relative ratio of nucleobases in an unknown sequence of DNA.
Orthogonal redox labelling of nucleobases with substituted ferrocenes with tuned redox potential was developed for redox coding of DNA bases.
Graphene oxide (GO) adsorbing a fluorophore-labeled single-stranded (ss) DNA serves as a sensor system because subsequent desorption of the adsorbed probe DNA from GO in the presence of complementary ...target DNA enhances the fluorescence. In this study, we investigated the interaction of single- and double-stranded (ds) DNAs with GO by using a fluorescently labeled DNA probe. Although GO is known to preferentially interact with ssDNA, we found that dsDNA can also be adsorbed on GO, albeit with lower affinity. Furthermore, the status of ssDNA or dsDNA previously adsorbed on the GO surface was investigated by adding complementary or noncomplementary DNA (cDNA or non-cDNA) to the adsorption complex. We observed that hybridization occurred between the cDNA and the probe DNA on the GO surface. On the basis of the kinetics driven by the incoming additional DNA, we propose a mechanism for the desorption of the preadsorbed probe DNA from the GO surface: the desorption of the GO-adsorbed DNA was facilitated following its hybridization with cDNA on the GO surface; when the GO surface was almost saturated with the adsorbed DNA, nonspecific desorption dominated the process through a simple displacement of the GO-adsorbed DNA molecules by the incoming DNA molecules because of the law of mass action. Our results can be applied to design appropriate DNA probes and to choose proper GO concentrations for experimental setups to improve specific signaling in many biosensor systems based on the GO platform.
PDF
