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Leaf curl, a whitefly-borne begomovirus disease, is the cause of frequent epidemic in chili. In the present study, transmission parameters involved in tripartite interaction are estimated to simulate disease dynamics in a population dynamics model framework. Epidemic is characterized by a rapid conversion rate of healthy host population into infectious type. Infection rate as basic reproduction number, R0 = 13.54, has indicated a high rate of virus transmission. Equilibrium population of infectious host and viruliferous vector are observed to be sensitive to the immigration parameter. A small increase in immigration rate of viruliferous vector increased the population of both infectious host and viruliferous vector. Migrant viruliferous vectors, acquisition, and transmission rates as major parameters in the model indicate leaf curl epidemic is predominantly a vector -mediated process. Based on underlying principles of temperature influence on vector population abundance and transmission parameters, spatio-temporal pattern of disease risk predicted is noted to correspond with leaf curl distribution pattern in India. Temperature in the range of 15–35 °C plays an important role in epidemic as both vector population and virus transmission are influenced by temperature. Assessment of leaf curl dynamics would be a useful guide to crop planning and evolution of efficient management strategies.

Temperature is one of the key factors influencing the viral disease development in plants. In this study effect of temperature on SYMMV accumulation and systemic movement was studied in French bean, mungbean and soybean cultivars by keeping them at temperatures range 22-25 °C, 26-29 °C and 30-33 °C. The proliferation of the virus under these conditions was confirmed through symptomatology, DAC-ELISA, RT-PCR with coat protein specific primers and RT-qPCR. French bean plants displayed symptoms by 12dpi at low temperature (22-25 °C) and by 3dpi at medium temperatures (26-29 °C) with continuous increase in viral accumulation from 0 to 24dpi. At high temperatures (30-33 °C), French bean did not show symptoms up to 12dpi but the virus accumulated and moved systemically. However, there was a decline in viral copy number after 12dpi. Mungbean plants showed mottling, mosaic and puckering symptoms at 22-25 °C and 26-29 °C and necrotic symptoms at 30-33 °C. Irrespective of temperature there was an increase in viral accumulation in mungbean from 0 days to 24dpi. Soybean plants showed veinal mild mottling at low and medium temperatures where as no peculiar symptom expression observed at high temperatures. Soybean also showed the reduction of viral copy number from 12 days to 24dpi at low and medium temperatures and from 6 days to 24dpi at high temperatures. These results indicate that temperature played an important role in SYMMV accumulation, movement and symptom expression in these three leguminous plant species. This study also demonstrates that SYMMV can replicate and spread in mungbean plants irrespective of the temperature.

Thrips palmi is an important insect pest of vegetables and ornamental crops worldwide. Besides direct damage caused by feeding, it transmits several tospoviruses in a persistent-propagative manner. Eggs of T. palmi are microscopic and embedded within plant tissue by the sharp ovipositor of adult female. In the present study, an artificial oviposition setup has been standardized for T. palmi. Eggs of T. palmi were harvested in sterile water between two thin membranes. The developmental stages of T. palmi embryo were studied starting from oviposition up to hatching by inverted and confocal reflection microscopy. Energids were homogeneously distributed at an early stage of development. The anterior end of the egg curved with a constriction post 38 h. Initiation of tissue organization, mouthparts, appendages, compound eyes were observed at different time points. Appendages were well developed and segmentation was prominent post 70 h. The embryo was completely developed at around 80 h and hatched by 86 h post oviposition at 28 °C temperature. The study first time reports the embryonic development of T. palmi that would be helpful in detailed investigations of thrips developmental biology and evolution.

This article reports the influence of the state of artificial ageing on the hardness, tensile properties and corrosion behavior of an Al-Mg-Si alloy. Pitting corrosion in 0.1 M NaOH solution and susceptibility to intergranular corrosion (IGC) have been systematically investigated, covering highly under-aged to highly over-aged states. In alkaline solution, corrosion rate increases with the progress of ageing; while for a given state of ageing, it initially increases with immersion time followed by rapid reduction since corrosion is controlled by the competition of formation and dissolution of Al(OH)3 plus Al2O3 film as determined by FESEM, EDS, and XRD characterizations. The IGC susceptibility of the selected alloy is found to be governed by the microstructure as determined by the state of ageing since it is controlled by the anodic dissolution of the precipitate free zones while closely neighboured grain boundary precipitates act as cathode. It is identified as slight to moderate pitting in highly under-aged, moderate to heavy pitting in under-aged, pitting with localized ICG in peak-aged, localized to uniform IGC in over-aged, and uniform IGC to etching in highly over-aged state. It is adjudged that apart from the inclusions like AlCrMnFeSi, the changes in the precipitation such as β” (Mg5Si6), β' (Mg9Si6) and β (Mg2Si) within the grains and at the grain boundaries with progress of artificial ageing play a pivotal role on mechanical properties and corrosion characteristics of the Al-Mg-Si alloy. Keywords: Al-Mg-Si, Ageing, Mechanical properties, Pitting, Intergranular corrosion

On the basis of first-principle calculations, we have studied the electronic and magnetic properties of a series of one-dimensional metal–organic frameworks (MOFs), labeled as MIT. These are coordi...

Plant virus diseases are significant constraints in agricultural production in Bangladesh. The hot and humid environmental conditions are highly favourable for the perpetuation of the viruses as well as vectors round the year. Although, the virus diseases are recorded in many crops, vegetables and pulses are most seriously affected. Several viruses belonging to the genera Begomovirus, Cucumovirus, Potyvirus and Tospovirus have been recorded during the last decade. Whitefly and thrips-transmitted viruses have emerged as major constraints in the horticultural crops. Management of viral diseases largely depends on the control of insect vectors by widespread application of insecticides. The epidemics of leaf curl, yellow vein, yellow mosaic and bud necrosis diseases were witnessed in the recent past. However, the knowledge of identity and diversity of viruses occurring in Bangladesh are largely lacking. This review provides the first comprehensive account of viral disease problems in the cultivation of several important crops and their management in Bangladesh.

Watermelon bud necrosis orthotospovirus (WBNV), is a distinct virus species in the genus Orthotospovirus, family Tospoviridae and order Bunyavirales. Orthotospovirus is the only genus in the family whose members infect plants, while viruses in other genera infect invertebrates. WBNV is prevalent in most of the watermelon growing Indian states and therefore, its prevalence in the Indian subcontinent cannot be ignored. Quasi-spherical enveloped virions are 80–110 nm in size. Virion composed of genomic RNAs with nucleoprotein, viral polymerase, and a lipid envelope with glycoprotein (GN/Gc) spikes. WBNV shares common genomic features with other orthotospoviruses. The tri-segmented genome is referred to as the small (S) (3.4 kb), the medium (M) (4.7 kb), and the large (L) (8.9 kb) RNAs. S RNA uses ambisense coding strategy and codes for non-structural (NSs) protein in the viral (v) sense and nucleocapsid (N) protein in the viral complementary (vc) sense. Similarly, M RNA uses ambisense coding strategy and codes for a precursor for the GN/GC in vc sense and movement (NSm) protein in v sense. L RNA is of negative polarity and codes for the RNA-dependent RNA polymerase (RdRp). WBNV is known to be transmitted by Thrips palmi (Order: Thysanoptera; Family: Thripidae; melon thrips) in a persistent propagative manner. WBNV is sap transmitted to various experimental hosts belonging to several families viz., Amaranthaceae, Asteraceae, Chenopodiaceae, Cucurbitaceae, Fabaceae, Pedaliaceae, and Solanaceae. WBNV has limited natural host range, predominantly confined to bitter gourd (Memordica charantia), chrysanthemum (Chrysanthemum indicum), chilli (Capsicum annum), cucumber (Cucumis sativus), muskmelon (Cucumis melo), pumpkin (Cucumis sativus), ridge gourd (Luffa acutangula), tomato (Solanum lycopersicum), and watermelon (Citrullus lanatus). Besides these main hosts, Abutilon indicum, Amaranthus spp., Euphorbia heterophylla, Malvastrum coromandelium, and Parthenium hysterophorus serve as green-bridge for virus perpetuation. WBNV symptoms include mottling, yellowing, necrotic streaks on vines, shortened internodes, stunted plant growth, severe stem and bud necrosis and dieback of the buds. Late season infection results in deformed fruits with necrotic local lesions. In India, WBNV resistant watermelon varieties are not available. A wild relative of watermelon, Citrullus colosynthis, has recently been identified as a resistant source, which is used in the breeding program as part of integrated disease management (IDM) strategies. IDM strategies include clean crop cultivation, border cropping, intercropping, use of plastic mulches, crop rotation, and control of thrips can alleviate the effect of WBNV in the Indian subcontinent. Recently, non-conventional management option of development of putative transgenic resistance has been worked out and found WBNV N gene is effective in conferring resistance in watermelon.

This paper proposes an efficient reconfigurable hardware design of dual microphone speech enhancement technique using sound source localization and multi band spectral subtraction methods with elimination of background noise. Firstly, we have used a time delay of arrival algorithm using phase transform (PHAT) to achieve the time difference between the microphone signals. PHAT based filter can reach high SNR gains, which makes it very suitable for localizing the sound source in a microphone array system. After adjustment of the delay between the signals, multi band spectral subtraction technique enhances the signal from the background noise environment in each of the frequency bands. Our design has been implemented in Spartan6 Lx45 FPGA and we have presented the implementation results in terms of subjective and objective evaluations. We have also compared the angular separation between the microphones to the resultant angle between the microphones and observed that proposed design provides very sharp accuracy in every corresponding angle. The objective and subjective evaluation established that our design provides better throughput compared to the existing state of the art research works. The evaluation infers that our proposed hardware induce feasibility for hand-held devices in background noisy environment.

Thrips are important pests of agricultural, horticultural, and forest crops worldwide. In addition to direct damages caused by feeding, several thrips species can transmit diverse tospoviruses. The present understanding of thrips–tospovirus relationships is largely based on studies of tomato spotted wilt virus (TSWV) and Western flower thrips (Frankliniella occidentalis). Little is known about other predominant tospoviruses and their thrips vectors. In this study, we report the progression of watermelon bud necrosis virus (WBNV) infection in its vector, melon thrips (Thrips palmi). Virus infection was visualized in different life stages of thrips using WBNV-nucleocapsid protein antibodies detected with FITC-conjugated secondary antibodies. The anterior midgut was the first to be infected with WBNV in the first instar larvae. The midgut of T. palmi was connected to the principal salivary glands (PSG) via ligaments and the tubular salivary glands (TSG). The infection progressed to the PSG primarily through the connecting ligaments during early larval instars. The TSG may also have an ancillary role in disseminating WBNV from the midgut to PSG in older instars of T. palmi. Infection of WBNV was also spread to the Malpighian tubules, hindgut, and posterior portion of the foregut during the adult stage. Maximum virus-specific fluorescence in the anterior midgut and PSG indicated the primary sites for WBNV replication. These findings will help to better understand the thrips–tospovirus molecular relationships and identify novel potential targets for their management. To our knowledge, this is the first report of the WBNV dissemination path in its vector, T. palmi.

The present investigation was undertaken to study the expression of eight defense related genes in leaf curl resistant line DLS-Sel-10 and susceptible line Phule Mukta after different days post inoculation (dpi) with viruliferous white flies to understand their role in resistance to chilli leaf curl virus (ChiLCV). The expression level of Ca PPO, Ca AsPer, Ca ATP/ADP and CaTopoII was observed to be higher in resistant genotype DLS-Sel-10 than the susceptible Phule Mukta at all the time points studied. Expression of CaNBS-LRR increased up to 12 dpi while that of Ca Thionin, and Ca SKP1 increased up to 24 dpi in the resistant line, thereafter it started declining. The CaSPI expression did not show any specific pattern in both the test plants. The heat map clustered all the genes under study into two major clusters based on their expression profiles, one comprising CaAsPer, Ca-Thionin, CaATP/ADP transporter, CaPPO and CaTopoII while other group comprised CaSKPI, Ca NBS and CaSPI. The challenge inoculation of the test genotypes also revealed that viral titre increased at a much slower rate in DLS-Sel-10 than Phule Mukta, suggesting thereby that DLS-Sel-10 is resisting the accumulation of ChiLCV and has a more active defense machinery than Phule Mukta.

Image processing on quantum platform is a hot topic for researchers now a day. Inspired from the idea of quantum physics, researchers are trying to shift their focus from classical image processing towards quantum image processing. This paper starts with a brief review of the principles which underlie quantum computing, and also deals with some of the basics of qubits and quantum computing. Then this paper starts to deal with some different methods of image storage, representation and retrieval in a quantum system. This paper also describes the advantages of using those methods in quantum systems compare to classical systems. In the next section, a short discussion on some of the important aspects, comparison among them and applications of quantum image processing is presented. A few other hot topics and open problems in quantum image processing are mentioned in this paper. This review article will provide the readership an overview of progress witnessed in the area of Quantum Image processing while also simulating further interest to pursue more advanced research in it.

By using a state-of-the-art theoretical method, we have investigated the electronic structure of a new class of nanocomposites, namely, porous graphene (PG)–fullerene (PG–fullerene) composite. We have utilized the porosity of PG to encapsulate the fullerene molecule into it and have investigated the efficacy of the PG–fullerene composite in solar cell and optoelectronic applications. Our study reveals that smaller sized composites show type-II band alignment, suggesting efficient charge separation upon photoexcitation. Hence, these composites may be utilized for designing solar cells. However, larger composites show type-I band alignment, thereby limiting their applications in solar cell. We further propose graphene antidot–fullerene composites with same pore structure as that of PG, which show type-II band alignment even for larger antidots. Qualitative analysis reveals that the electron injection rate as well as charge separation capability of antidot composites is larger than that of the PG composites....

Watermelon bud necrosis orthotospovirus (WBNV) is one of the emerging and most serious pathogens affecting watermelon cultivation in India. In the present study, the effect of different inoculation methods and buffer formulation on virus transmission was studied and validated in 17 watermelon genotypes. Among various inoculation methods used, maximum transmission efficiency 60–100% was obtained in 4–10 days post-inoculation (DPI) with pin-pricking and rubbing together, followed by rubbing (85–100%; 20–25 DPI) and pin-pricking (10–32%; 10–25 DPI) alone with the sodium buffer (PBS) having pH 7.0 supplemented with sodium sulfite (SS) and 2-mercaptoethanol (2-ME). Similarly, among the various abrasives used, maximum transmission efficiency 82–100% was obtained at 10–35 DPI with Celite and Carborundum together, followed by Celite (64–100%; 10–20 DPI) and Carborundum (72–100%; 20–40 DPI) alone. Among various additives used, maximum transmission efficiency 82–100% was obtained in 10 DPI with PBS supplemented with SS and 2-ME followed by PBS supplemented with SS alone (85–100%; 20–40 DPI) and PBS with no additive (76–85%; 20–35 DPI). The 15–20 days old watermelon plants were found suitable for the efficient mechanical transmission (100%) and to obtain maximum virus titre (Absorbance at 405 nm) i.e. 1.52–2.50 at 8–25 DPI. The 21–60% and 100% transmission was obtained at 4 and 10 DPI, respectively using the same buffer composition as mentioned above. For validation of optimized sap inoculation protocol for WBNV, 17 watermelon genotypes were inoculated under glasshouse conditions and the percent transmission ranged from 80 to 100%. Besides symptomatology, virus transmission was further confirmed by DAC-ELISA, RT-PCR and sequencing of the partial N gene. The O. D. at 405 nm ranged from 0.38 to 0.9 in naturally infected watermelon plants whereas in the glasshouse inoculated watermelon plants it was ranged from 0.30 to 0.73 at 15 DPI. This is the first effort on optimization of more efficient sap inoculation protocol for WBNV and it validated to 17 watermelon genotypes.

We investigated the structural, magnetic, and electronic properties of 5,10,15,20-tetrakis(4-pyridyl)porphyrin (TPyP) metal organic frameworks (MOFs). A spin-liquid state was found in FeTPyP–Fe and CoTPyP–Co MOFs. Long-range ferromagnetism was observed in FeTPyP–Co and CoTPyP–Fe MOFs. Ferromagnetic coupling in the CoTPyP–Fe (FeTPyP–Co) MOF was attributed to through-bond spin polarization (both spin delocalization and through-bond spin polarization). Our calculations revealed CoTPyP–Fe to be a half-metal. Dirac bands in the CoTPyP–Co and FeTPyP–Co MOFs might be responsible for the high reactivity of these MOFs in oxygen evolution reactions (OERs). The highest reactivity of FeTPyP–Co among the other TPyP MOFs might be related to the many frontier Dirac bands in the conduction band of FeTPyP–Co. In addition, the hazardous gas capturing ability of the most reactive MOF, FeTPyP–Co MOF, was examined. The adsorption of all gas molecules studied was energetically favorable, and the observed adsorption energies in...

Bud necrosis disease (BND) caused by watermelon bud necrosis orthotospovirus (WBNV), has emerged a major deterrent in watermelon cultivation in Indian subcontinent. In the present study, identification of resistance source against WBNV under field and glasshouse conditions was carried out, wherein a total of the 45 watermelon genotypes were evaluated during 2010–11 and 2011–12 crop seasons in a randomized block design with three replications each. Field evaluation was carried out using 0–4 disease rating scale. Of the 45 watermelon genotypes, a wild relative, Citrullus colosynthis showed highly resistant (HR) reaction against BND during both the crop seasons (absorbance @ 405 nm: 0.07-0.28). While, five genotypes viz., PWMH-1, PWMH-2, PWMH-3, PWMH-12 and PWMH-20 during 2010–11 showed moderately resistant (MR) reaction against BND under field condition however, the varied absorbance was recorded as 0.97, 1.74, 1.01, 0.14 and 0.14, respectively in these genotypes. Whereas, during 2011–12, PWMH-34, PWMH-36 and PWMH-37 showed highly susceptible (HS) reaction under field condition. Absorbance of all the field evaluated genotypes during 2011–12 was ranged from 0.19–1.47. In glasshouse evaluation of selected 25 genotypes, C. colosynthis showed 40% transmission therefore it was found MR reaction while, the rest of genotypes showed HS reaction against WBNV. Moreover, five genotypes viz., PWMH-1, PWMH-2, PWMH-3, PWMH-12, and PWMH-20 showed MR reaction under field condition during 2010–11, but under glasshouse condition these genotypes showed HS reaction except the C. colosynthis. Value of absorbance at 15 DPI in glasshouse inoculated plants ranged from 0.12–0.90 with the percent transmission of 40–100% at 35 DPI. Therefore, C. colosynthis is the source of resistance against WBNV and it is being utilized in development of WBNV resistant varieties in the Indian conditions.

Graphene-oxide-decorated with iron-cerium carbonate was synthesized in a hydrothermal reaction with varied carbonate content. After successful synthesis and characterization, visible-light-driven photocatalytic activity was tested using a 20-W lamp to initiate the rapid degradation of organic dyes via a photo Fenton process. The band gap and surface area were heavily dependent on the carbonate content, as reflected in the photocatalytic activity. The most probable structure of the cluster and its composite with graphene oxide was studied using first-principle theoretical calculations, and the band gaps were calculated. We established that cerium plays a key role in lowering the band gap of the cluster and determined that the catalyst produces a reactive oxygen species (ROS). ROS is an active component in the rapid degradation of dyes such as methylene blue, which has a quantitative and repetitive degradation.

A simple and rapid lateral flow immunoassay (LFIA) was developed by utilizing gold nanoparticles conjugated to a polyclonal antibody against coat protein of large cardamom chirke virus (LCCV). The LFIA based on the principle of sandwich immunoassay detected LCCV within ∼10 min and the result could be evaluated visually. The colloidal gold (CG) was made using 1% gold chloride solution. The LCCV IgG (1 μg/μl) and Mouse IgG (0.5 μg/μl) were conjugated with CG individually and coated onto a conjugate pad at 1:1 ratio. A sample extraction procedure was optimized in order to get adequate clear leaf sap of large cardamom leaf within few minutes. The sensitivity limit of the detection was 1:40 dilution of LCCV infected leaf sap. The diagnostic performance of LFIA was compared with ELISA using field samples. The LFIA was free from false positive as no visible test line was developed with healthy and potyviruses such as papaya ringspot virus and potato virus Y. The diagnostic specificity and sensitivity of LFIA was 100% and 90%, respectively. The Cohen's kappa coefficient (0.701) suggested a very good agreement between the ELISA and LFIA. Receiver operating characteristic analysis indicated that LFIA was a robust method as the area under the curve (0.950) is significantly (P0.0001) broader.

By using the state-of-the-art theoretical method, we have investigated the electronic structures of recently synthesized two-dimensional azine-linked covalent organic framework (ACOF-1). Our result indicates that ACOF-1 is a direct band gap semiconductor, suggesting useful application in nanoelectronics. Its one-dimensional (1D) structure also exhibits semiconducting properties. Furthermore, this azine-linked COF is found to be practically useful for selective sensing of nitroaromatics over nitroaliphatics. Lastly, our calculations reveal a more realizable way for using two tautomers of ATFG-COF, a derivative of ACOF-1, in conductance switching device by means of transport property calculation. Therefore, our present study may provide a guideline for multifunctionalities of azine-linked COF (ACOF-1).

The effect of Groundnut bud necrosis virus (GBNV) infection on the life history traits of its vector, Thrips palmi, and its feeding preference on GBNV-infected plants were studied. A significant difference was observed in the developmental period (first instar to adult) between the GBNV-infected and healthy thrips, wherein the developmental period of GBNV-infected thrips was decreased. However, there was no effect on the other parameters such as preadult mortality, adult longevity, and fecundity. Further investigation on a settling and feeding choice assay of T. palmi to GBNV-infected and healthy plants showed that T. palmi preferred GBNV-infected cowpea plants more than the healthy cowpea plants. This preference was also noticed for leaf disks from GBNV-infected cowpea, groundnut, and tomato plants.

By using first principle calculations we have studied the magnetic, electronic and transport properties of zigzag-graphene nanoribbon (zGNR) with a topological line defect (LD) composed of pentagons and heptagons (5-7). We show that one can engineer the magnetic and electronic properties of the edge passivated zGNR with 5-7 LD through the variation of either the width of the zGNR or the position of the LD. Thus, one can have ferromagnetic behaviour in zGNR by introducing 5-7 LD close to one edge of the ribbon. One can tune the zGNR with 5-7 LD from semi-metallic to semi-metallic semiconductor either by increasing the width of the ribbon or by changing the position of the LD. We have also studied the effect of the doping on the degeneracy of the spin states of 4-4-LD-zGNR. The calculation of transport properties of N-doped 4-4-LD-zGNR reveals that it has high spin filtering efficiencies. The tuning of the spin polarization through the formation of 5-7 LD in zGNR holds a promise for its application in spintronic devices.

Inspired by recent experimental synthesis of two-dimensional cobalt bis(dithioline) (CoBHT) metal–organic surface (J. Am. Chem. Soc., 2015, 137, 118–121), herein, using first principle calculations, we have investigated the electronic and magnetic properties of two-dimensional BHT-based metal (M = Co, Fe, Mn, Cr)-organic frameworks (MBHT). Our detailed theoretical calculations predict that CoBHT, FeBHT, and MnBHT are planar ferromagnetic (FM) half-metals, whereas CrBHT is planar spin-frustrated kagome lattice antiferromagnetic (AFM) semimetal, a new state of matter referred as spin-liquid. These planar ferromagnetic half-metal materials are promising candidates for spintronic devices. Further, polluting gas such as CO can be detected by these MOFs as there is remarkable variation of electronic and magnetic properties after gas adsorption. Interestingly, these properties have been found to be a function of coordination environment of central metal atom, which is actually a coordinatively unsaturated (CUS) ...

Whitefly-transmitted begomoviruses cause serious damage to many economically important food, feed, and fiber crops. Numerous vegetable crops are severely affected and chilli leaf curl virus (ChiLCV) is the most dominant and widely distributed begomovirus in chilli (Capsicum annuum) throughout the Indian subcontinent. Recently, CRISPR-Cas9 technology was used as a means to reduce geminivirus replication in infected plants. However, this approach was shown to have certain limitations such as the evolution of escape mutants. In this study, we used a novel, multiplexed guide RNA (gRNA) based CRISPR-Cas9 approach that targets the viral genome at two or more sites simultaneously. This tactic was effective in eliminating the ChiLCV genome without recurrence of functional escape mutants. Six individual gRNA spacer sequences were designed from the ChiLCV genome and in vitro assays confirmed the cleavage behaviour of these spacer sequences. Multiplexed gRNA expression clones, based on combinations of the above-mentioned spacer sequences, were developed. A total of nine-duplex and two-triplex CRISPR-Cas9 constructs were made. The efficacy of these constructs was tested for inhibition of ChiLCV infection in Nicotiana benthamiana. Results indicated that all the constructs caused a significant reduction in viral DNA accumulation. In particular, three constructs (gRNA5+4, gRNA5+2 and gRNA1+2) were most effective in reducing the viral titer and symptoms. T7E1 assay and sequencing of the targeted viral genome did not detect any escape mutants. The multiplexed genome-editing technique could be an effective way to trigger a high level of resistance against begemoviruses. To our knowledge, this is the first report of demonstrating the effectiveness of a multiplexed gRNA-based plant virus genome editing to minimize and eliminate escape mutant formation.

Plant virus-based vectors provide attractive and valuable tools for rapid production of recombinant protein in large quantities as they produce systemic infections in differentiated plant tissues. In the present study, we engineered the Soybean yellow mottle mosaic virus (SYMMV) as a gene expression vector which is a promising candidate for systemic expression of foreign proteins in French bean plants. Full virus vector strategy was exploited for insertion of foreign gene by inserting MCS through PCR in the circular pJET-SYMMV clone. To examine the ability of the SYMMV vector system, GFP gene was cloned after the start codon of coat protein (CP) so that its expression was driven by the SYMMV-CP subgenomic promoter. When in vitro run off SYMMV-GFP transcript was mechanically inoculated to French bean leaves, good level of GFP expression was observed through confocal microscopy up to 40 dpi. Expression of heterologous protein was also confirmed through ISEM, DAC-ELISA and RT-PCR with specific primers at 20 dpi. The recombinant SYMMV construct was stable in in vitro runoff transcript inoculated plants but the inserted GFP was lost in progeny virion inoculated plants. The system developed here will be useful for further studies of SYMMV gene functions and exploitation of SYMMV as a gene expression vector.

Watermelon bud necrosis virus (WBNV) and Groundnut bud necrosis virus (GBNV) are two closely related tospovirus species infecting several crops in India. In the present study, specific diagnostic assays for these two most predominant tospoviruses were developed by comparing host reactions and genome sequence information. Bioassay was developed by sap transmission of both the viruses to a set of host plants, cowpea, groundnut and watermelon. WBNV induced only local symptoms including chlorotic spots on cowpea cv. Pusa Komal, typical chlorotic ring spots on cv. C-152, bud necrosis on watermelon and no symptoms on groundnut. Whereas, GBNV induced both local and systemic symptoms including chlorotic/necrotic spots and veinal necrosis on both the cowpea cultivars, systemic yellowing and bud necrosis on groundnut and no symptoms on watermelon. Single and duplex RT-PCR was developed for diagnosis of WBNV and GBNV by designing primers based on differential sequence from Gn/Gc genes located on M RNA and from nucleocapsid protein (NP) gene located on S RNA genome. The duplex RT-PCR using NP gene specific primers was successfully utilised for the diagnosis of natural infection of GBNV in dahlia and muskmelon and mixed infection of GBNV and WBNV in chrysanthemum. The amplified products of duplex RT-PCR were sequenced and phylogenetic analysis confirmed the authenticity of the RT-PCR assay as well as confirmed infection of WBNV and GBNV in the new natural hosts. The bioassay and RT-PCR developed in this study will be useful in detecting single and mixed infection of GBNV and WBNV strains in different crops.

Inspired by a very recent theoretical work on penta-graphene, a two dimensional (2D) carbon sheet [Proc. Nat. Acad. Sci. 2015, 112 , 2372] composed of only carbon pentagons, we have made an attempt to see the stability and electronic properties of its one dimensional (1D) ribbons, naming penta-graphene nanoribbon (pentaGNR). Our first principle calculations predict that, pentaGNR is dynamically stable; it is mechanically flexible tolerating upto 11.5% of axial strain. We have also explored the electronic properties of the nanoribbons with different widths which show interesting charge separation for wider ribbons. The band gap of wider ribbons changes only marginally with further increasing the ribbon width which opens up the possibility of a stable nanoribbon with large band gap which is very useful for designing optoelectronic devices.

By using density-functional tight-binding method we have calculated the electronic structure of graphene quantum dot (GQD)-fullerene hybrid systems and explored the efficacy of their use in designing solar cells. We have shown that the electronic energy levels of the nanohybrids can be tuned either by varying the size of the quantum dots or by proper functionalization of the quantum dot (QD). The GQD-fullerene nanohybrids form type-I or type-II band energy alignment depending upon the size of the GQD. Thus, hybrid systems with smaller sized QDs form type-II band energy alignment while those of larger GQDs form type-I alignment. The type-II band alignment confirms the spatial charge separation for the systems and thus the rate of recombination of charge carriers will be low. The value of ΔG i.e. the difference in energy between the LUMO of the donor (GQD) and LUMO of the acceptor (fullerene) which measures the rate of electron injection from the donor to the acceptor is also large for the nanohybrids with smaller GQDs. So, we suggest that GQD-fullerene nanocomposites with smaller GQD will be a suitable system for photovoltaic devices. We also show that the type-II band energy alignment for the nanohybrids with larger QDs can be achieved through the functionalization of the GQD with electron donating group such as -NH2.

With the help of first-principle calculations we have proposed a new 2D metal-organic framework (MOF) consisting of a -NH substituted coronene molecule and transition metals. Our study reveals that formation of such crystals is exothermic in nature, i.e. it is an energetically favourable process. The mode of magnetic coupling between the local magnetic moments and hence the overall magnetic moment of the MOF can be tuned by changing the transition metal. Not only the magnetic properties, but also the electronic structure of the MOF can be regulated from half-metal to spin-semiconductor to semimetallic-semiconductor by altering the metal center from Cr to Mn to Fe/Co. Our study also indicates that the change in the ligand structure and its anchoring group is also very effective in tuning the electronic properties of MOFs. The study of transport properties reveals that the half-metallic crystal possesses the maximum value of the spin-filtering efficiency, i.e. 100%.

Quantum computing promises to outperform classical computing in terms of algorithmic speedup for certain classes of computational problems. A quantum algorithm exploits quantum mechanical processes like superposition, interference, and entanglement that works on quantum states of matter providing exponential or super polynomial speedup. In recent times, multi-valued quantum computing is gaining popularity due to its higher state space dimension, and ternary quantum computing is one of the most popular multi-valued quantum computing. In this paper, we propose an algorithmic approach for the generation of quantum ternary superposition operators and evaluating them in terms of trace distance, fidelity, and the entanglement measure. We also propose five new quantum ternary superposition operators, which have larger trace distance and smaller fidelity than the existing ternary superposition operators “Chrestenson gates” and “S-gate” (Sudhindu Bikash, IEEE Comput Soc 2014, [1]). To characterize the amount of entanglement in two given qutrit composite ternary states, we also measure the concurrence of the newly proposed and the existing quantum superposition operators. We have shown that the newly proposed superposition operators generate maximally entangled states with concurrence equal to 1.

Cardamom bushy dwarf virus (CBDV) causes foorkey disease of large cardamom (Ammomum subulatum Roxburgh) in the eastern sub-Himalayan mountains. Although the aphid Micromyzus kalimpongensis Basu (Hemiptera: Aphididae) is known as a vector of CBDV, its behavior in dissemination of CBDV has not been investigated. In the present study, M. kalimpongensis was observed to colonize in higher number on CBDV-infected large cardamom plants compared with the healthy plants in the several plantations in Sikkim and Darjeeling hills. The affinity of M. kalimpongensis to the diseased large cardamom plants was further confirmed in a contained field experiment with intact plant as well as in a laboratory bioassay with the plant extract, where significantly higher number of aphids settled on the diseased plants or extracts compared with the healthy counterparts. Aphids grown on CBDV-infected large cardamom plants had shortened nymphal period and increased longevity and fecundity compared with those grown on the healthy plants. In the contained field experiment, M. kalimpongensis migrated to the CBDV-infected plants, colonized there, acquired CBDV, and once the diseased plants withered, migrated to healthy plants, which eventually became diseased. Our results suggest a general pattern of spread of CBDV by M. kalimpongensis where CBDV-infected plants attract or arrest and stimulate emergence and migration of viruliferous aphids that otherwise are sedentary in the underground plant parts of large cardamom. To our knowledge, this is the first study that shows the influence of a plant virus from the family Nanoviridae in altering behavior of its insect vector that favors its dissemination.

The genus, Babuvirus of the family Nanoviridae contains three virus species, Abaca bunchy top virus (ABTV), Banana bunchy top virus (BBTV) and Cardamom bushy dwarf virus (CBDV). In India, only two babuviruses, BBTV and CBDV are known to affect banana and large cardamom, respectively. BBTV, which causes bunchy top disease in banana, is a nationally important virus as it is widely prevalent in all the banana growing states including North-East region. Whereas, CBDV, which causes foorkey disease of large cardamom, is of regional importance as it is restricted only in the North-Eastern sub-Himalayan mountains. Early infection of these babuviruses cause 100% yield loss. Bunchy top of banana and foorkey disease of large cardamom are known in India for a long time and considerable information has been generated. This chapter summarises the biological and molecular properties of both the babuviruses occurring in India.

Aphids are important group of vectors of plant viruses, where all three modes of transmission viz. non-persistent, semi-persistent and persistent are observed. In India, exploration of aphid species in vector-virus study was started during 1945 and subsequently, several aphid species have been identified as vectors of many important plant viruses. The studies in India was focused in identifying vectors, recording transmission efficiency, determining transmission parameters, recording distribution, and seasonal incidence and developing management options. A summary of these studies conducted in India so far is presented in this chapter.

The begomoviruses (genus Begomovirus, family Geminiviridae) constitute the largest group of plant viruses causing devastating crop diseases in India. About 16% geminiviruses recorded worldwide occur in India. Begomovirus associated disease was recorded in India as early as 1924. During 1980s, begomovirus disease and the vector whitefly, Bemisia tabaci emerged as serious problems in many vegetable and pulse crops. The molecular characterisation studies on begomoviruses in India began during late 1980s and during last decade, a large number of begomoviruses were discovered causing diseases such as mosaic, yellow mosaic, yellow vein mosaic and leaf curl in numerous crops and wild plants. Currently, 322 begomovirus species have been officially recognised all over the world, of which about 82 begomovirus species are known to occur in India. The Indian subcontinent represents one of the important centres for begomoviruses origin and diversity. In this chapter, research work on identification and characterization of begomoviruses in diverse crops in India is presented. Geographic distribution, phylogenetic relationship, infectivities of cloned genome components, recombination, replication events, suppression of RNAi silencing, viral gene funtions as pathogenicity determinants and association of satellites and their role in disease development with reference to the Indian begomoviruses are discussed.

Image representation in a multilevel quantum system is always an important issue now a day. This paper initially proposes two approaches which help to represent color images in a ternary quantum system based on the modified concept of famous FRQI model and normalized amplitude based quantum representation model. But these approaches are complicated and have several drawbacks. Finally, a simple and a new model of color image representation and storage in a ternary (3-levels) quantum system is presented in this paper. This model deals with a set of quantum states for M different color levels and another set of quantum states for P different position coordinates. In this paper, various gray levels of a color image and their corresponding positions are stored in a \(3^n\) color quantum register. For sake of simplicity this proposed method is carried out on 3 \(\times \) 3 pixels of color image example and the model is built by using basic ternary gates. A basic measurement of a pixel in a quantum image is also presented in this paper. Comparisons among these three quantum image representation approaches are also discussed at the last section of this paper.

Tospoviruses of the family Bunyaviridae are very significant viral pathogens in several crops in India. A total of 11 tospovirus species has been recognised worldwide, of which five tospovirus species, Groundnut bud necrosis virus (GBNV), Groundnut yellow spot virus (GYSV), Iris yellow spot virus(IYSV), Watermelon bud necrosis virus (WBNV) and Tomato spotted wilt virus (TSWV) are known to occur in India. In addition to these tospoviruses, a tentative member, Capsicum chlorosis virus (CaCV) has also been documented in India. Tospoviruses are major constraints in vegetable and pulse crops in India. GBNV is the most prevalent and destructive tospovirus in India, which has been detected in 30 different crops and weed species belonging to eight families and other tospoviruses are restricted in nature with reference to host and geographical region. The present chapter summarises the research work on tospoviruses carried out in India during the past more than half a century.

This paper proposes an efficient reconfigurable hardware design of sound source localization system using one microphone pair. We have used time delay of arrival (TDOA) algorithm using phase transform (PHAT) to achieve time difference between the microphone signals. Phased transform (PHAT) based filter can reach high SNR gains, which makes it very suitable for localizing the sound source in a microphone array system. Our design has implemented on Spartan6 Lx45 FPGA and presented the implementation results in terms of accuracy and speech quality. We compare the original angle between the microphones to the resultant angle between the microphones and observed that proposed design provides very sharp accuracy in every corresponding angle. We also compare the speech quality of proposed design signal with normal delayed signal. The evaluation infers that our proposed hardware induce feasible for hand-held devices.

Thrips being important sucking pests transmit the deadly tospoviruses in comercial crops in a persistent and propagative manner. Sixteen thrips species are known to transmit 29 tospoviruses worldwide. In India, only six thrips species are so far known to transmit six tospoviruses. The first study in India on thrips is dated in 1856. The research on tospoviruses was initiated in India during 1960s, however, the first study on thrips-tospovirus was published in 1981. Not many studies have been undertaken on the thrips-tospovirus in India. Several reviews have been published on the thrips-tospovirus research, where the Indian works have hardly been reflected. In this chapter, we summarise the studies on thrips-tospovirus undertaken in India.

Traditional machine learning shares several benefits with quantum information processing field. The study of machine learning with quantum mechanics is called quantum machine learning. Data clustering is an important tool for machine learning where quantum computing plays a vital role in its inherent speed up capability. In this paper, a hybrid quantum algorithm for data clustering (quantum walk-based hybrid clustering (QWBHC)) is introduced where one-dimensional discrete time quantum walks (DTQW) play the central role to update the positions of data points according to their probability distributions. A quantum oracle is also designed and it is mainly implemented on a finite [Formula: see text]-regular bipartite graph where data points are initially distributed as a predefined set of clusters. An overview of a quantum walk (QW) based clustering algorithm on 1D lattice structure is also introduced and described in this paper. In order to search the nearest neighbors, a unitary and reversible DTQW gives a quadratic speed up over the traditional classical random walk. This paper also demonstrates the comparisons of our proposed hybrid quantum clustering algorithm with some state-of-the-art clustering algorithms in terms of clustering accuracy and time complexity analysis. The proposed quantum oracle needs [Formula: see text] queries to mark the nearest data points among clusters and modify the existing clusters. Finally, the proposed QWBHC algorithm achieves [Formula: see text] performance.

Croton yellow vein mosaic virus (CYVMV, genus Begomovirus family Geminiviridae) is a proliferating begomovirus in the Indian sub-continent. The infectious constructs in binary vector was developed against the CYVMV genome and its associated betasatellite. Agroinoculation of the genomic construct of CYVMV produced leaf curl symptoms alone in three species of tobacco, Nicotiana tabacum, N. benthamiana and N. glutinosa. Co-inoculation of betasatellite enhanced the severity of the disease and reduced the incubation time. Based on the infectious clone, a replicon vector pCro, with only the ability to replicate inside the plant was developed. In pCro vector, CP and V2 ORFs from genome of CYVMV was deleted, which resulted localised replication of the molecule with no visible symptoms. Besides the partial CYVMV genome, pCro also has a cassette containing a double 35S promoter, multiple cloning sites and a NOS terminator to overexpress any foreign protein in plant. Episomal release of the replicon from the binary vector backbone after agroinoculation was detected by PCR. A GFP gene was cloned in pCro vector (pCro-GFP) and agroinoculated to N. tabacum resulted in localized expression of GFP at 5 dpi. The CYVMV replicon vector will be a useful tool for studying functional genomics, vaccine expression and gene silencing in plant.

Marker-free (MF) constructs were developed using 825 bp and 426 bp N genes of watermelon bud necrosis orthotospovirus (WBNV). N genes were amplified and cloned in pDrive (825 bp) and/or pGEMT (426 bp) vectors and recombinants were confirmed. pCAMBIA 2300 was restricted with Xho I to release npt II gene and re-circularized; it is called MF-pCAMBIA 2300. GUS cassette with promoter and terminator from pBI 121 was cloned into the MCS region of MF-pCAMBIA 2300 with EcoRI and Hind III. Eluted PCR products of 825 and 426 bp were cloned in already developed MF-pCAMBIA 2300. These N gene constructs were then mobilized in Agrobacterium tumefaciens strain EHA 105. Agroinfiltration of A. tumefaciens harbouring MF-pCAMBIA 2300 N gene constructs was practised by syringe method in 20-day-old watermelon seedlings. PCR amplification showed 825 and 426 bp amplicons which confirmed their presence in agroinfiltrated seedlings. Further, three days of post agroinfiltration seedlings were challenge-inoculated with WBNV and kept under artificial light for 3–6 days. Agroinfiltrated and inoculated seedlings were tested by ELISA and resulted positive with OD ranging from 0.31 to 0.46 and 0.35 to 0.43 in full and partial N genes respectively. Six days post-inoculation, necrosis and complete drying of the leaves were observed. The systemic upper young leaves were subjected to DAC-ELISA and results revealed negative reaction with OD ranging from 0.11 to 0.19. The N gene constructs conferred resistance against WBNV in watermelon.