35 research outputs found

    A Novel Approach for Detection of DoS / DDoS Attack in Network Environment using Ensemble Machine Learning Model

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    One of the most  serious threat to network security is Denial of service (DOS) attacks. Internet and computer networks are now important parts of our businesses and daily lives. Malicious actions have become more common as our reliance on computers and communication networks has grown. Network threats are a big problem in the way people communicate today. To make sure that the networks work well and that users' information is safe, the network data must be watched and analysed to find malicious activities and attacks. Flooding may be the simplest DDoS assault. Computer networks and services are vulnerable to DoS and DDoS attacks. These assaults flood target systems with malicious traffic, making them unreachable to genuine users. The work aims to enhance the resilience of network infrastructures against these attacks and ensure uninterrupted service delivery. This research develops and evaluates enhanced DoS/DDoS detection methods. DoS attacks usually stop or slow down legal computer or network use. Denial-of-service (DoS) attacks prevent genuine users from accessing and using information systems and resources. The OSI model's layers make up the computer network. Different types of DDoS strikes target different layers. The Network Layer can be broken by using ICMP Floods or Smurf Attacks. The Transport layer can be attacked using UDP Floods, TCP Connection Exhaustion, and SYN Floods. HTTP-encrypted attacks can be used to get through to the application layer. DoS/DDoS attacks are malicious attacks. Protect network data from harm. Computer network services are increasingly threatened by DoS/DDoS attacks. Machine learning may detect prior DoS/DDoS attacks. DoS/DDoS attacks proliferate online and via social media. Network security is IT's top priority. DoS and DDoS assaults include ICMP, UDP, and the more prevalent TCP flood attacks. These strikes must be identified and stopped immediately. In this work, a stacking ensemble method is suggested for detecting DoS/DDoS attacks so that our networked data doesn't get any worse. This paper used a method called "Ensemble of classifiers," in which each class uses a different way to learn. In proposed  methodology Experiment#1 , I used the Home Wifi Network Traffic Collected and generated own Dataset named it as MywifiNetwork.csv, whereas in proposed methodology Experiment#2, I used the kaggle repository “NSL-KDD benchmark dataset” to perform experiments in order to find detection accuracy of dos attack detection using python language in jupyter notebook. The system detects attack-type or legitimate-type of network traffic during detection ML classification methods are used to compare how well the suggested system works. The results show that when the ensembled stacking learning model is used, 99% of the time it is able to find the problem. In proposed methodology two Experiments are implemented for comparing detection accuracy with the existing techniques. Compared to other measuring methods, we get a big step forward in finding attacks. So, our model gives a lot of faith in securing these networks. This paper will analyse the behaviour of network traffics

    Pseudomonas syringae addresses distinct environmental challenges during plant infection through the coordinated deployment of polysaccharides

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    Prior to infection, phytopathogenic bacteria face a challenging environment on the plant surface, where they are exposed to nutrient starvation and abiotic stresses. Pathways enabling surface adhesion, stress tolerance, and epi phytic survival are important for successful plant pathogenesis. Understanding the roles and regulation of these path ways is therefore crucial to fully understand bacterial plant infections. The phytopathogen Pseudomonas syringae pv. tomato (Pst) encodes multiple polysaccharides that are implicated in biofilm formation, stress survival, and virulence in other microbes. To examine how these polysaccharides impact Pst epiphytic survival and pathogenesis, we ana lysed mutants in multiple polysaccharide loci to determine their intersecting contributions to epiphytic survival and infection. In parallel, we used qRT–PCR to analyse the regulation of each pathway. Pst polysaccharides are tightly coordinated by multiple environmental signals. Nutrient availability, temperature, and surface association strongly af fect the expression of different polysaccharides under the control of the signalling protein genes ladS and cbrB and the second messenger cyclic-di-GMP. Furthermore, functionally redundant, combinatorial phenotypes were observed for several polysaccharides. Exopolysaccharides play a role in mediating leaf adhesion, while α-glucan and alginate together confer desiccation tolerance. Our results suggest that polysaccharides play important roles in overcoming environmental challenges to Pst during plant infection

    Characterization of the transient fluorescence wave phenomenon that occurs during H-2 production in Chlamydomonas reinhardtii

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    The redox state of the plastoquinone (PQ) pool in sulfur-deprived, H-2-producing Chlamydomonas reinhardtii cells was studied using single flash-induced variable fluorescence decay kinetics. During H-2 production, the fluorescence decay kinetics exhibited an unusual post-illumination rise of variable fluorescence, giving a wave-like appearance. The wave showed the transient fluorescence minimum at 60 ms after the flash, followed by a rise, reaching the transient fluorescence maximum at 1 s after the flash, before decaying back to the initial fluorescence level. Similar wave-like fluorescence decay kinetics have been reported previously in anaerobically incubated cyanobacteria but not in green algae. From several different electron and proton transfer inhibitors used, polymyxin B, an inhibitor of type II NAD(P)H dehydrogenase (NDA2), had the effect of eliminating the fluorescence wave feature, indicating involvement of NDA2 in this phenomenon. This was further confirmed by the absence of the fluorescence wave in the Delta nda2 mutant lacking NDA2. Additionally, Delta nda2 mutants have also shown delayed and diminished H-2 production (only 23% if compared with the wild type). Our results show that the fluorescence wave phenomenon in C. reinhardtii is observed under highly reducing conditions and is induced by the NDA2-mediated electron flow from the reduced stromal components to the PQ pool. Therefore, the fluorescence wave phenomenon is a sensitive probe for the complex network of redox reactions at the PQ pool level in the thylakoid membrane. It could be used in further characterization and improvement of the electron transfer pathways leading to H-2 production in C. reinhardtii

    Photosystem ratio imbalance promotes direct sustainable H-2 production in Chlamydomonas reinhardtii

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    The green alga Chlamydomonas reinhardtii can photoproduce H-2 gas for only a few minutes under anaerobic conditions due to the inhibition of hydrogenase by O-2 produced by Photosystem II (PSII). A few days of sustained H-2 production can only be achieved when O-2 and H-2 production are temporally separated under two-stage processes such as sulfur deprivation. Under sulfur deprivation, H-2 production is initiated after the over-reduction of the plastoquinone pool and decreased PSII activity in the thylakoid membrane. As a result, activated hydrogenase consumes the excess of electrons produced by PSII [Volgusheva et al., Proc. Natl. Acad. Sci. U. S. A., 2013, 110, 7223]. Here, we report that similar conditions can be achieved by simply altering the ratio between photosystem I (PSI) and PSII. In the C3 mutant of C. reinhardtii, we found a lower PSI/PSII ratio than in the wild type, 0.33 vs. 0.85, respectively. This imbalance of photosystems resulted in the over-reduced state of the plastoquinone pool and activation of hydrogenase in the C3 mutant that allowed the photoproduction of H-2 continuously for 42 days. This is an unprecedented duration of H-2 production in green algae under standard growth conditions without any nutrient limitation. Photosynthetic electron flow from PSII to hydrogenase was closely regulated during this long-term H-2 production. The amount of PSII was decreased and the amount of PSI was increased reaching a PSI/PSII ratio of more than 5 as shown by EPR and fluorescence spectroscopy. This fine-tuning of photosystems allows to sustain the long-term production of H-2 in C. reinhardtii by a direct photosynthetic pathway

    Microstructural Features and Wear Characteristics of Semi-Solid Processed A356 Aluminum Alloy

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    In the present study the microstructural features and tribological characteristics of hot forged A356 Al alloy subjected to SIMA (Strain induced melt activation) and T6 heat treatment (semi-solid) processes have been investigated. The SIMA process consists of hot forging of alloy at 325˚C followed by cold forging at room temperature, isothermal holding at 580˚C for 10 min and quenching. In case of T6 heat treatment, the hot forged alloy was solution treated at 540˚C for 4 hours followed by quenching in cold water and artificial aging at 155˚C for 3 hours. The microstructure of the alloy exhibited a spherical or globular morphology of the primary α-phase with uniform distribution of solutes in the interdendritic region. A detailed analysis of the solidification behaviour of the melt from semi-solid region of the alloy is reported. The reasons for the consequential changes in tribological properties of A356 Al alloy processed by SIMA andT6 heat treatment have been clearly brought out

    Draft genome sequence of Bacillus okhensis Kh10-101T, a halo-alkali tolerant bacterium from Indian saltpan

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    We report the 4.86-Mb draft genome sequence of Bacillus okhensis strain Kh10-101T, a halo-alkali tolerant rod shaped bacterium isolated from a salt pan near port of Okha, India. This bacterium is a potential model to study the molecular response of bacteria to salt as well as alkaline stress, as it thrives under both high salt and high pH conditions. The draft genome consist of 4,865,284 bp with 38.2% G + C, 4952 predicted CDS, 157 tRNAs and 8 rRNAs. Sequence was deposited at DDBJ/EMBL/GenBank under the project accession JRJU00000000

    Localized corrosion of an ultrafine grained Al-4Zn-2Mg alloy produced by cryorolling

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    The effect of microstructure on corrosion behaviour of an ultrafine grained (UFG) Al-4Zn-2Mg alloy produced by cryorolling was investigated. Both UFG and coarse grained (CG) alloys in peak-aged condition were subjected to potentiodynamic polarization and intergranular corrosion (IGC) tests in chloride solutions. UFG alloy exhibited increased corrosion potential (E-corr), decreased corrosion current density (i(corr)) (-864 mV(SCE), 0.60 mu A/cm(2)) during polarization and lower weight loss during IGC when compared with CG alloy (-902 mV(SCE), 4.9 mu A/cm(2)). Improved corrosion resistance of UFG alloy is mainly attributed to sub-micrometer grains, absence of coarse MgZn2 anodic precipitates and precipitate-free zones along the grain boundaries. (c) 2012 Elsevier Ltd. All rights reserved

    Pseudomonas syringae addresses distinct environmental challenges during plant infection through the coordinated deployment of polysaccharides

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    Prior to infection, phytopathogenic bacteria face a challenging environment on the plant surface, where they are exposed to nutrient starvation and abiotic stresses. Pathways enabling surface adhesion, stress tolerance, and epiphytic survival are important for successful plant pathogenesis. Understanding the roles and regulation of these pathways is therefore crucial to fully understand bacterial plant infections. The phytopathogen Pseudomonas syringae pv. tomato (Pst) encodes multiple polysaccharides that are implicated in biofilm formation, stress survival, and virulence in other microbes. To examine how these polysaccharides impact Pst epiphytic survival and pathogenesis, we analysed mutants in multiple polysaccharide loci to determine their intersecting contributions to epiphytic survival and infection. In parallel, we used qRT–PCR to analyse the regulation of each pathway. Pst polysaccharides are tightly coordinated by multiple environmental signals. Nutrient availability, temperature, and surface association strongly affect the expression of different polysaccharides under the control of the signalling protein genes ladS and cbrB and the second messenger cyclic-di-GMP. Furthermore, functionally redundant, combinatorial phenotypes were observed for several polysaccharides. Exopolysaccharides play a role in mediating leaf adhesion, while α-glucan and alginate together confer desiccation tolerance. Our results suggest that polysaccharides play important roles in overcoming environmental challenges to Pst during plant infection

    Measurements of surface ozone at semi-arid site Anantapur (14.62 degrees N, 77.65 degrees E, 331 m asl) in India

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    Abstract In the present study, an attempt has been made to examine the governing photochemical processes of surface ozone (O3) formation in rural site. For this purpose, measurements of surface ozone and selected meteorological parameters have been made at Anantapur (14.62°N, 77.65°E, 331 m asl), a semi-arid zone in India from January 2002 to December 2003. The annual average diurnal variation of O3 shows maximum concentration 46 ppbv at noon and minimum 25 ppbv in the morning with 1σ standard deviation. The average seasonal variation of ozone mixing ratios are observed to be maximum (about 60 ppbv) during summer and minimum (about 22 ppbv) in the monsoon period. The monthly daytime and nighttime average surface ozone concentration shows a maximum (55±7 ppbv; 37±7.3 ppbv) in March and minimum (28±3.4 ppbv; 22±2.3 ppbv) in August during the study period. The monthly average high (low) O3 48.9±7.7 ppbv (26.2± 3.5 ppbv) observed at noon in March (August) is due to the possible increase in precursor gas concentration by anthropogenic activity and the influence of meteorological parameters. The rate of increase of surface ozone is high (1.52 ppbv/h) in March and lower (0.40 ppbv/h) in July. The average rate of increase of O3 from midnight to midday is 1 ppbv/h. Surface temperature is highest (43–44°C) during March and April months leading to higher photochemical production. On the other hand, relative humidity, which is higher during the rainy season, shows negative correlation with temperature and ozone mixing ratio. It can be seen that among the two parameters are measured, correlation of surface ozone with wind speed is better (R2=0.84) in compare with relative humidity (R2=0.66)
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