3,129 research outputs found

    Molecular analysis reveals that lack of chasmothecia formation in Erysiphe necator in Maharashtra, India is due to presence of only MAT1-2 mating type idiomorph

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    The heterothallic, ubiquitous fungus Erysiphe necator causes powdery mildew disease of grapevines and in many countries it is reported to reproduce both asexually and sexually. Sexual reproduction results in the formation of chasmothecia (cleistothecia) on infected surfaces when the colonies of two opposite mating types meet on the infected plant parts and the temperatures are favorable for their development. Chasmothecia are reported from north India, but not from peninsular India, even though powdery mildew is reportedly present in these regions at least since the beginning of the last century. Through systematic survey of ten vineyards in Maharashtra and adjoining Karnataka in peninsular India, we confirmed the absence of chasmothecia under natural conditions. Analysis of temperature data from two locations in Maharashtra showed that the Tmax and Tmin were favourable for chasmothecia initiation (10 °C to 30 °C) and maturation (15 °C to 30 °C) for a sufficient period of time.Multiplex PCR of 120 E. necator field isolates collected from peninsular India showed presence of a single band of 232 bp corresponding to MAT1-2 mating type idiomorph or MAT- phenotype. None of the samples gave band of 408 bp corresponding to MAT1-1 mating type idiomorph. Further, two bands of 408 bp and 232 bp were detected in only one powdery mildew sample collected from Kashmir, in north India while the other nineteen samples gave a single band of 232 bp.  Thus, molecular analysis established that E. necator is not sexually reproducing in Maharashtra due to presence of only one mating type idiomorph. The study also brings out that MAT1-1 mating type idiomorph is not as common in nature as MAT1-2 and explains why in many other countries, too, chasmothecia were first observed as late as half to one century after start of grape cultivation.  &nbsp

    Biochemical changes in banana fruits due to postharvest fungal pathogens

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    The nutritional value of fruits chiefly depends on the quality and quantity of nutritive substances. In the present investigation, four fungi were studied from banana fruits which cause considerable biochemical changes to alter the quality of banana fruit. The infected bananas showed a decrease in the quantity of total soluble sugar, protein, ash, ascorbic acid and mineral elements when compared with the control of fruit. B.theobromae, R.oryzae, G.musarum, A.niger, A.flavus and F.roseum were found to be associated with the ripening of bananas and also causes rot during storage

    Effect of fungal infections on nutritional value of papaya fruits

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    The nutritional value of fruits chiefly depends on the quality & quantity of nutritive substances. Various fungi causes rots in fruits of papaya. The fungi are very selective in their nutritional requirements. They influence the stored substances by observing them or by converting some of the complex forms into simple ones. In the present investigation total five fungi were isolated from papaya fruits. The effect of these fungi on considerable losses in proteins, ash and nitrogen content were observed in the papaya fruits. In general the amount of the amino acids in free as well as bound forms increased in infected fruits. Considerable decrease in total sugar and increase in reducing sugar was observed in most of the fungi

    How to Influence People with Partial Incentives

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    We study the power of fractional allocations of resources to maximize influence in a network. This work extends in a natural way the well-studied model by Kempe, Kleinberg, and Tardos (2003), where a designer selects a (small) seed set of nodes in a social network to influence directly, this influence cascades when other nodes reach certain thresholds of neighbor influence, and the goal is to maximize the final number of influenced nodes. Despite extensive study from both practical and theoretical viewpoints, this model limits the designer to a binary choice for each node, with no way to apply intermediate levels of influence. This model captures some settings precisely, e.g. exposure to an idea or pathogen, but it fails to capture very relevant concerns in others, for example, a manufacturer promoting a new product by distributing five "20% off" coupons instead of giving away one free product. While fractional versions of problems tend to be easier to solve than integral versions, for influence maximization, we show that the two versions have essentially the same computational complexity. On the other hand, the two versions can have vastly different solutions: the added flexibility of fractional allocation can lead to significantly improved influence. Our main theoretical contribution is to show how to adapt the major positive results from the integral case to the fractional case. Specifically, Mossel and Roch (2006) used the submodularity of influence to obtain their integral results; we introduce a new notion of continuous submodularity, and use this to obtain matching fractional results. We conclude that we can achieve the same greedy (11/eϵ)(1-1/e-\epsilon)-approximation for the fractional case as the integral case. In practice, we find that the fractional model performs substantially better than the integral model, according to simulations on real-world social network data

    Multiple carcasses of Olive Ridleys along Malvan Beach

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    The Olive Ridley turtle (Lepidochelys olivacea) is protected under the Indian Wildlife (Protection) Act, 1972. Maharashtra government along with NGOs are undertaking several efforts in conservation of sea turtles along the coast. There is a state sponsored incentive program of `500 for locating and sharing information with forest officials. Malvan coast in Sindhudurg district of Maharashtra is known for turtle and fisheries interactions. Occasional turtle nestings can be seen between November to April

    Facile Rapid Synthesis of Polyaniline (PANI) Nanofibers

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    A Polyaniline (PANI) nanofibers have been successfully synthesized by a facile rapid oxidative polymerization of aniline hydrochloride and ammonium persulfate at high temperature (60 C). The structural and optical properties of PANI nanofibers are investigated by using X-ray diffraction (XRD), UV-VIS Spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The XRD analysis ascertains formation of PANI with nanocrystalline nature with average crystallite size 30 nm. Further, FTIR pattern confirmed the formation of PANI. SEM analysis has revealed homogeneous fibrous morphology of PANI nanofibers, a well formed mesh of interconnected and entangled PANI nano-fibers over the scanned area. The UV-VIS spectroscopic analysis shows three major absorption peaks at 256.73, 361.17 and 480.95 nm confirmed the PANI formation with conducting state

    Bio-Efficacy of Aureofungin-sol in Control of Downy and Powdery Mildews in Grape

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    Bio-efficacy of Aureofungin-sol, an antifungal antibiotic, for control of downy mildew and powdery mildew of grape was evaluated during October 2008 - April 2009 fruiting season in vineyards at three locations in Maharashtra. Four to nine sprays of Aureofungin-sol, @ 0.108, 0.163 and 0.217 g/l, starting from 12-16 days to 46-75 days after fruit pruning gave good control of downy mildew on leaves and bunches, and increased harvestable yield over the Control. Similarly, four sprays of Aureofungin-sol @ 0.108 g/l at 11 to 20 days' interval at 65 days after pruning provided complete control of powdery mildew on leaves and bunches. No residue of Aureofungin-sol was found in harvest samples above the limit of detection (0.1 mg/kg)

    Marine turtle conservation programs in villages of Ratnagiri, Maharashtra

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    Maharashtra is active in sea turtle conservation and its citizen actions with support of forest department are highly commendable particularly in some regions of southern Maharashtra. During the surveys conducted at Harne and Kolthare villages of Ratnagiri in March 2019 it was observed that local volunteers known as “Kasav Mitra” identified by Forest Department, in Ratnagiri District of Maharashtra are undertaking beach patrolling and relocating the eggs to secured enclosures for multiple reasons such as the egg sites being too close to tide water level, beaches open to public that can result in eggs being unknowingly crushed by beachgoers, or dug up by dogs or targeted poaching

    Synthesis of Cuprous Oxide (Cu2O) Nanoparticles – a Review

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    Cuprous Oxide (Cu2O) a semiconductor material oxide; with unique optoelectronic properties; gains significant importance for its synthesis in view of its various technological and industrial applications. A few liquid phase methods for the synthesis of Cu2O nanoparticles are reviewed on the basis of materials, methodology, synthesis conditions and key findings. A comparative study of these methods is also performed following criteria of repeatability, safety, cost, time span and simplicity. Contextual to the above mentioned criteria, three liquid phase synthesis techniques were shortlisted and actually experimented (as reported) to synthesize the Cu2O nanoparticles. This was done to investigate the effectiveness, repeatability and stability of the synthesized Cu2O product as a function of ageing time. The synthesized Cu2O using all these techniques are prone to be unstable and undergo the rapid phase change to CuO phase which was ascertained from the shift of absorbance peak in UV-VIS spectra. The results have highlighted the urgent need to develop a facile, economical, scalable and safe method to synthesize stable Cu2O nanoparticles at room temperature
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