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Peer-to-peer network is one in which each node in the network can act as a client or server for the other nodes in the network. It allows shared access to various resources such as files, peripherals, and sensors without the need for a central server. Content distribution in the P2P network from server is done by multicasting. Multicasting is the process of sending the data to the multiple designations. This technology is highly efficient for the large scale multimedia content delivery in P2P network where the end peer have identical set of system components. But in reality, the peers have heterogeneous set of requirements for different service levels as well as different service components. The ability to provide differentiated services to each peer with widely varying requirements is becoming important. We need to provide differentiated Services above the existing shared network infrastructure. The solution proposed to solve the above said problem is to provide individualized service to each peer. It focuses on constructing and maintaining an efficient multiple overlay multicast tree structure in the P2P network. The tree maintenance process is governed by two mechanisms called as dynamic reconfiguration driven by peer and less frequent tree maintenance by network status change observation. In this paper new scalable architecture is constructed and analysed based on the above strategies., Comment: 6 pages,5 figures

Block scheduling is difficult to implement in P2P network since there is no central coordinator. This problem can be solved by employing network coding technique which allows intermediate nodes to perform the coding operation instead of conventional store and forward the received data. There is a general assumption in this area of research so far that a target download rate is always attainable at every peer as long as coding operation is performed at all the nodes in the network. An interesting study is made that a maximum download rate can be attained by performing the coding operation at relatively small portion of the network. The problem of finding the minimal set of node to perform the coding operation and links to carry the coded data is called as a network code minimization problem (NCMP). It is proved to be NP hard problem. It can be solved using genetic algorithm (GA) because GA can be used to solve the diverse NP hard problem. A new NCMP model is proposed which considers both minimize the resources needed to perform coding operation and dynamic change in network topology due to disconnection. Based on this new NCMP model, an effective and novel GA is proposed by implementing problem specific GA operators into the evolutionary process. There is an attempt to implement the different compositions and several options of GA elements which worked well in many other problems and pick the one that works best for this resource minimization problem. Our simulation results prove that the proposed system outperforms the random selection and coding at all possible node mechanisms in terms of both download time and system throughput., Comment: 20 pages

Most of the existing P2P content distribution schemes implement a random or rarest piece first dissemination procedure to avoid duplicate transmission of the same pieces of data and rare pieces of data occurring in the network. This problem can be solved using peer-to-peer content distribution based on network coding scheme. Network coding scheme uses random linear combination of coded pieces. Hence the above stated problem can be solved ease and simple. Our proposed mechanism uses network coding mechanism in which several contents of same message is grouped into different group and coding operation is performed only within the same group. The interested peers are also divided into several groups with each group have the responsibility to spread one set of contents of some message. The coding system is designed to assure the property that any subset of the messages can be utilized to decode the original content as long as the size of the subset is suitably large. To meet this condition, dynamic smart network coding scheme is defined which assures the preferred property, then peers are connected in the same group to send the corresponding message, and connect peers in different groups to disseminate messages for carrying out decoding operation. Moreover, the proposed system can be readily expanded to support topology change to get better system performance further in terms of reliability, link stress and throughput. The simulation results prove that the proposed system can attain 20 to 25% higher throughput than existing systems, it also further attains good reliability, link failure and robustness to peer churn., Comment: this article consists of 14 pages

Trichoderma harzianum is used as a biocontrol agent to manage Phytophthora foot rot of black pepper (Piper nigrum L.) in India. Several organic materials such as sorghum, neem cake, decomposed coir pith and farmyard manure are used both as multiplication and carrier media for T. harzianum. The effect of these carrier media on the population build up of T. harzianum in black pepper rhizosphere and their effect on microflora and fauna was studied. The organic materials increased the population of introduced T. harzianum and also increased populations of fungi, bacteria, microarthropods and nematodes. In case of sorghum, there was a sudden spurt in the population of saprophytic nematodes and mycophagous mites within 15 days followed by a succession of predatory mites and nematodes. The unspent carbohydrate and mycelial form of T.harzianum in sorghum perhaps helped in the population build up of soil microarthropods and nematodes, which in turn affect the biocontrol efficiency of the introduced organism.

Trichoderma harzianum is used as a biocontrol agent to manage Phytophthora foot rot of black pepper (Piper nigrum L.) in India. Several organic materials such as sorghum, neem cake, decomposed coir pith and farmyard manure are used both as multiplication and carrier media for T. harzianum. The effect of these carrier media on the population build up of T. harzianum in black pepper rhizosphere and their effect on microflora and fauna was studied. The organic materials increased the population of introduced T. harzianum and also increased populations of fungi, bacteria, microarthropods and nematodes. In case of sorghum, there was a sudden spurt in the population of saprophytic nematodes and mycophagous mites within 15 days followed by a succession of predatory mites and nematodes. The unspent carbohydrate and mycelial form of T.harzianum in sorghum perhaps helped in the population build up of soil microarthropods and nematodes, which in turn affect the biocontrol efficiency of the introduced organism.

Six strains of Pseudomonas fluorescens, which had been found efficient in root-rot suppression in black pepper (Piper nigrum L.) caused by Phytophthora capsici were tested for their ability in rejuvenating Phytophthora infected black pepper cuttings. Among the treatments, which had only bacterial application, IISR-6 ensured survival of 67% of the infected cuttings where as only 22% of the untreated plants survived 3 months after treatment, The combined application of IISR-51, IISR-6+IISR-13 and I1SR-51+IISR-11 with Metalaxyl-Mancozeb resulted in 100% survival of the infected plants, showing an additive effect. Experiments conducted for root-proliferation activity of the P. fluorescens showed that the bacterial strains helped increase the root biomass of the plants (30-135%). All the strains increased the root length and root area in the treated plants (12-127%, 43-200%, respectively). Strains were also found to produce plant growth hormones, viz. IAA&GA.

Six strains of Pseudomonas fluorescens, which had been found efficient in root-rot suppression in black pepper (Piper nigrum L.) caused by Phytophthora capsici were tested for their ability in rejuvenating Phytophthora infected black pepper cuttings. Among the treatments, which had only bacterial application, IISR-6 ensured survival of 67% of the infected cuttings where as only 22% of the untreated plants survived 3 months after treatment, The combined application of IISR-51, IISR-6+IISR-13 and I1SR-51+IISR-11 with Metalaxyl-Mancozeb resulted in 100% survival of the infected plants, showing an additive effect. Experiments conducted for root-proliferation activity of the P. fluorescens showed that the bacterial strains helped increase the root biomass of the plants (30-135%). All the strains increased the root length and root area in the treated plants (12-127%, 43-200%, respectively). Strains were also found to produce plant growth hormones, viz. IAA&GA.