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Piece selection policy in dynamic P2P networks play crucial role and avoid the last piece problem. BitTorrent uses rarest-first piece selection mechanism to deal with this problem, but its efficacy is limited because each peer only has a local view of piece rareness. The problem of piece section is multiple objectives. A novel fuzzy programming approach is introduced in this article to solve the multiple objectives piece selection problem in P2P network, in which some of the factors are fuzzy in nature. Piece selection problem has been prepared as a fuzzy mixed integer goal programming piece selection problem that includes three primary goals such as minimizing the download cost, time, maximizing speed and useful information transmission subject to realistic constraints regarding peer's demand, capacity and dynamicity. The proposed approach has the ability to handle practical situations in a fuzzy environment and offers a better decision tool to each peer to select optimal pieces to download from other peers in dynamic P2P network. Extensive simulations are carried out to demonstrate the effectiveness of the proposed model. It is proved that proposed system outperforms existing with respect to download cost, time and meaningful exchange of useful information. [ABSTRACT FROM AUTHOR]

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 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 an 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 which considers both minimize the resources needed to perform coding operation and dynamic change in network topology due to disconnection is proposed. 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. [ABSTRACT FROM AUTHOR]

Most of the existing peer-to-peer (P2P) content distribution schemes carry out a random or rarest piece first content dissemination procedure to avoid duplicate transmission of the same pieces of data and rare pieces of data occurring in the network. This problem is solved using P2P content distribution based on network coding scheme. Network coding scheme uses random linear combination of coded pieces. Hence, the above-stated problem is solved easily and simply. Our proposed mechanism uses network coding mechanism in which several contents having the same message are grouped into different groups and coding operation is performed only within the same group. The interested peers are also divided into several groups with each group having the responsibility to spread one set of contents of messages. 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 (DSNC) 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 is 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 20–25% higher throughput than existing systems, good reliability, link failure and robustness to peer churn. [ABSTRACT FROM AUTHOR]

One of the spark plug leak detectors employed in high temperature liquid sodium systems had failed to detect a sodium leak and systematic failure analysis was carried out to identify the root cause of the failure. Radiography image of the leak port nozzle revealed that the extension wire which was welded with spark plug electrode had snapped. Since the failure originated from the cracks present in the weld, it was decided to standardize the welding procedure of spark plug electrode to extension wire to prevent the possibility of similar failures in future. Three different materials viz, stainless steel, nickel, inconel were chosen as extension wires as well as filler wires to optimize the welding parameters. Microstructural studies in terms of presence of defects, interface integrity between the weld and extension wire as well as that of spark plug electrode were carried out. Based on this, the final choice of welding parameters, material for extension wire and for filler wire to achieve a sound weld was proposed. [ABSTRACT FROM AUTHOR]

The present study envisaged to document the endophytic fungal association with black pepper through a series of in vitro and in planta investigations. Black pepper was found to harbour endophytic fungal flora belonging to the genera Alternaria, Acremonium, Aspergillus, Cladosporium, Chaetomium, Curvularia, Colletotrichum, Fusarium, Humicola, Paecilomyces, Rhizoctonia, Phoma and non-sporulating forms. Further, it was found that the endocarp of black pepper seed is free from culturable endophytic fungi. This was evident from the absence of culturable fungi in in vitro grown black pepper seedlings. The growth of fungi from the seedlings grown under green house conditions reveal that the fungal endophytes establish from fungal propagules falling on the (test) plants that may enter the plant tissues as back ground inoculum and grow as endophyte. This was also supported by the study that the type of endophytic fungi that harbour black pepper plants varied with geographical locations from where the samples were collected. [ABSTRACT FROM AUTHOR]

In this paper, a fuzzy logic--based jamming detection algorithm (FLJDA) is proposed to detect the presence of jamming in downstream data communication for cluster-based wireless sensor networks. The proposed FLJDA keeps an eye on the existing nodes and new node to determine their behavior by applying fuzzy logic on measured jamming detection metrics. To monitor the behavior of the nodes, the FLJDA computes the jamming detection metrics, namely, packet delivery ratio and received signal strength indicator. The major features of this paper are the following: (1) The jamming detection algorithm is specifically implemented for downstream data communication, (2) cluster head estimates jamming detection metrics for detecting the jamming unlike the existing algorithms where individual nodes explicitly collect the jamming detection metrics, and (3) the proposed algorithm optimizes the jamming detection metrics on the basis of fuzzy logic unlike the existing approaches, which uses merely jamming detection threshold alone for jamming detection. The simulation results of the proposed system provide the true detection ratio as high as 99.89%. [ABSTRACT FROM AUTHOR]

Floral diversity in monoecious type nutmeg reveals three types of flowers namely; pistillate, staminate and hermaphrodite flowers. The structure of hermaphrodite flowers in nutmeg is reported for the first time. The flowers are borne on the leaf axil, flowering habit of the three types of flowers are seen in cymes as well as solitary in the same tree. The gynoecium consists of single ovary with bifid stigma in the pistillate flowers and the androecium of staminate flowers has adnate 7-13 anthers. Intra flower variability is evident in case of hermaphrodite flowers. In hermaphrodite flower the androecium ranges with 1-4 anthers, in the form of fused filament or free filament or both; some anthers are fused with the gynoecium. Besides remnants of the stamen in the developed fruits of hermaphrodite flowers, staminodes are also observed in the flowers. Colour of all the three types of flowers are light creamy yellow, with thick gamosepalous perianth which bursts as bilobed, trilobed, tetralobed and pentalobed lobes during anthesis. Analysis of variance of trees for flower types and floral attributes like flower type, number of anthers, length of anthers, length of filaments and length of ovary are found to be highly significant. High coefficient of variation is recorded for hermaphrodite (183.84%) and pistillate (171.71%) flowers. The pollen viability of the hermaphrodite flowers are found less as compared to the staminate flowers. The percentage of pollen viability is 79.74 and 90.77 in hermaphrodite and male flower respectively. In the population studied, the occurrence of hermaphrodite flower in monoecious tree ranged from 0 - 10%. [ABSTRACT FROM AUTHOR]

Plant antimicrobial peptides are the interesting source of studies in defense response as they are essential components of innate immunity which exert rapid defense response. In spite of abundant reports on the isolation of antimicrobial peptides (AMPs) from many sources, the profile of AMPs expressed/identified from single crop species under certain stress/physiological condition is still unknown. This work describes the AMP signature profile of black pepper and their expression upon Phytophthora infection using label-free quantitative proteomics strategy. The differential expression of 24 AMPs suggests that a combinatorial strategy is working in the defense network. The 24 AMP signatures belonged to the cationic, anionic, cysteine-rich and cysteine-free group. As the first report on the possible involvement of AMP signature in Phytophthora infection, our results offer a platform for further study on regulation, evolutionary importance and exploitation of theses AMPs as next generation molecules against pathogens. [ABSTRACT FROM AUTHOR]

Phytophthora foot rot is a devastating disease in black pepper which is caused by P. capsici . Using host resistance is a major component in the integrated pest management of this disease. To explore the host resistance pattern, we studied the genotype specific differential expression of important pathogenesis related gene β 1, 3 glucanase and 5 R gene loci from resistant and susceptible varieties of black pepper. The relative expression of β 1, 3 glucanase was up regulated in resistant variety and down regulated in susceptible variety. R gene loci Pn CNBS 5, CNBS 3 and Pn CNBS 2 showed up regulation in susceptible variety in the early hours of infection while resistant genotype recorded its down regulation till 72 h suggesting that the selective down expression of these loci may be attributed to the resistance in the resistant variety. These R genes may be the susceptibility genes (S-genes) in black pepper for Phytophthora . The high relative expression of the R gene locus Pn CNBS 4 and Pn CNBS 1 in resistant genotype at early hours shows their involvement in resistance towards P. capsici. The differential expression of the R gene loci shows the genotype specific functional significance for Phytophthora resistance. [ABSTRACT FROM AUTHOR]

The Indian mango ginger (Curcuma amada Roxb.) is a perennial rhizomatous herb with a raw mango flavour. It is resistant to bacterial wilt disease. In order to understand the disease resistance mechanism of mango ginger the hexane, chloroform and methanol extracts (5, 10, 25, 50 and 100 mg mL-1) and essential oils (1%, 5% and 10%) were tested against the bacterial wilt pathogen Ralstonia solanacearum by agar well diffusion method. The hexane, chloroform and methanol extracts showed more or less the same level of antimicrobial activity with a zone of inhibition ranging from 3-9 mm. The essential oils exhibited a zone of inhibition ranging from 3-7 mm. The major constituents of the essential oils were ß-myrcene and ß-pinene. The results indicated that the rhizome of mango ginger may contain compounds that are toxic to the pathogen. The extracts of mango ginger could be explored further for developing a natural bactericide against R. solanacearum. [ABSTRACT FROM AUTHOR]

Background:Immunological characterization of mycobacterial peptides may help not only in the preparation of a vaccine for leprosy but also in developing in vitro T-cell assays that could perhaps be used as an in vitro correlate for treatment outcome. The main goal of this study was to evaluate the use of Mycobacterium bovis recombinant 32-kDa protein (r32-kDa) antigen-stimulated T-cell assay as a surrogate marker for treatment outcome and monitor vitamin D receptor (VDR)-mediated anti-microbial responses during multidrug therapy (MDT) in leprosy. Methods:Newly diagnosed tuberculoid and lepromatous leprosy patients were enrolled and followed up during their course of MDT at 6 and 12 months. IFN-Υ, IL-10, IL-17 and IL-23 levels in culture supernatants and expression of VDR, TLR2, LL37 and DEFB in r32-kDa-stimulated PBMCs were measured. Controls comprised household contacts (HHCs) and healthy endemic subjects (HCs). Results:Significant differences were observed in the levels of IFN-Υ, IL-17, IL-23, VDR and anti-microbial peptides LL37 and DEFB after treatment and when compared with that of HHCs and HCs, respectively. Conclusions:These findings suggest that responses to r32-kDa antigen reflect an improved immunological and antimicrobial response in leprosy patients during therapy, thereby indicating its potential use as an immune correlate in the treatment of leprosy patients. [ABSTRACT FROM AUTHOR]

Experiment on in vitro screening of 125 endophytic fungi of black pepper against Phytophthora capsici indicated that 23 isolates showed more than 50% inhibition. The nematicidal activity of metabolites from endophytic fungi was also tested on Radopholus similis and the isolate BPEF73 (Daldinia eschscholtzii) showed highest mortality up to 60%. The isolates showing biocontrol potential were characterized based on internal transcribed spacer (ITS1 and ITS2) regions of rDNA. The sequence analysis of the isolates showed maximum identity with Annulohypoxylon nitens (BPEF25 and BPEF38), Daldinia eschscholtzii (BPEF41 and BPEF73), Fusarium spp. (BPEF72 and BPEF75), Ceriporia lacerata (BPEF81), Diaporthe sp. (BPEF11) and Phomopsis sp. (BPEF83). This is first report of endophytic association of above fungi in black pepper and the exploitation of their biocontrol potential against the major black pepper pathogens P. capsici and R. similis. [ABSTRACT FROM AUTHOR]

Single-carrier frequency division multiple access (SC-FDMA) systems with space frequency block coding (SFBC) transmissions achieve both spatial and frequency diversity gains in wireless communications. However, SFBC SC-FDMA schemes using linear detectors suffer from severe performance deterioration because of noise enhancement propagation and additive noise presence in the detected output. Both issues are similar to inter-symbol-interference (ISI). Traditionally, SC-FDMA system decision feedback equalizer (DFE) is often used to eliminate ISI caused by multipath propagation. This article proposes frequency domain turbo equalization based on nonlinear multiuser detection for uplink SFBC SC-FDMA transmission systems. The presented iterative receiver performs equalization with soft decisions feedback for ISI mitigation. Its coefficients are derived using minimum mean squared error criteria. The receiver configuration study is Alamouti's SFBC with two transmit and two receive antennas. New receiver approach is compared with the recently proposed suboptimal linear detector for SFBC SC-FDMA systems. Simulation results confirm that the performance of the proposed iterative detection outperforms conventional detection techniques. After a few iterations, bit-error-rate performance of the proposed receiver design is closely to the matched filter bound. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Phytophthora capsici is one of the most destructive pathogens of black pepper in India and the world over. Diversity of 114 Phytophthora isolates obtained from leaf, stem, root and soil of different agro climatic areas was studied using 25 SSR primers that were previously described. twenty primers were successfully amplified. Of these, 15 were polymorphic among the Phytophthora isolates and altogether 37 loci were detected. Of the 37 bands generated from 20 primers, 75.67% were polymorphic. Cluster analysis using the unweighted pair-group method with arithmetic averages divided the isolates into seven major groups. The dendrogram generated showed that all the isolates were separated at similarity coefficient between 57-95%. Group 7 with a single isolate stood as an out group. Clustering did not follow the pattern of geographical origin or plant part from where the isolates were obtained. [ABSTRACT FROM AUTHOR]

Single-carrier frequency division multiple access is greatly sensitive to carrier frequency offset (CFO) between transceivers. This leads to the destruction of orthogonality among subcarriers, which in turn leads to inter-carrier interference and multiple access interference between different users. Minimum mean square error (MMSE) equalizer that uses an inverse operation on an interference matrix with a dimension equal to the number of subcarriers is normally used to invalidate CFO effects. Hence, the terminal processing complexity is very high. The proposed conjugate gradient method attempts to mitigate the higher computational complexity by iteratively evaluating the MMSE solution without direct matrix inverse operation. To further mitigate the multiple access interference, MMSE combined with parallel interference cancellation is also implemented. The analysis of the proposed method shows better performance and fast convergence in single-carrier frequency division multiple access systems. The maximum iteration number to formulate an accurate solution is almost equal to the number of active users in the uplink access. Simulation results bring out the effectiveness of the present method compared with the existing CFO compensation schemes in terms of computational complication and system performance with large frequency offsets. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Network coding (NC) makes content distribution more effective and easier in P2P content distribution network and reduces the burden of the original seeder. It generalizes traditional network routing by allowing the intermediate nodes to generate new coded packet by combining the received packets. The randomization introduced by network coding makes all packets equally important and resolves the problem of locating the rarest block. Further, it reduces traffic in the network. In this paper, we analyze the performance of traditional network coding in P2P content distribution network by using a mathematical model and it is proved that traffic reduction has not been fully achieved in P2P network using traditional network coding. It happens due to the redundant transmission of noninnovative information block among the peers in the network. Hence, we propose a new framework, called I2NC (intelligent-peer selection and incremental-network coding), to eliminate the unnecessary flooding of noninnovative coded packets and thereby to improve the performance of network coding in P2P content distribution further. A comparative study and analysis of the proposed system is made through various related implementations and the results show that 10–15% of traffic reduced and improved the average and maximum download time by reducing original seeder’s workload. [ABSTRACT FROM AUTHOR]

A novel jamming detection technique to detect the presence of jamming in the downstream direction for cluster based wireless sensor networks is proposed in this paper. The proposed technique is deployed in base station and in cluster heads. The proposed technique is novel in two aspects: Firstly, whenever a cluster head receives a packet it verifies whether the source node is legitimate node or new node. Secondly if a source node is declared as new node in the first step, then this technique observes the behavior of the new node to find whether the new node is legitimate node or jammed node. In order to monitor the behavior of the existing node and new node, the second step uses two metrics namely packet delivery ratio (PDR) and received signal strength indicator (RSSI). The rationality of using PDR and RSSI is presented by performing statistical test. PDR and RSSI of every member in the cluster is measured and assessed by the cluster head. And finally the cluster head determines whether the members of the cluster are jammed or not. The CH can detect the presence of jamming in the cluster at member level. The base station can detect the presence of jamming in the wireless sensor network at CH level. The simulation result shows that the proposed technique performs extremely well and achieves jamming detection rate as high as 99.85%. [ABSTRACT FROM AUTHOR]