629 research outputs found

    Morphological and molecular characterization of a new microsporidian (Protozoa: Microsporidia) isolated from Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae)

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    A microsporidium was isolated from larvae of Spodoptera litura (Fabricius) collected from Tamil Nadu, India. This microsporidian species is monomorphic, disporous and develops in direct contact with the cytoplasm of the host cell. The nuclear configuration of merogonic and sporogonic stages was diplokaryotic. The merogonic proliferative stage was unusual that normal development with 1, 2 and 4 binucleated forms were common, while large multinucleate meronts containing 8 and 12 small compact horseshoe-like diplokaryotic nuclei were also observed. The fresh spores were typically ovocylindrical in shape, with a mean size of 3.91× 1.91 μm and the polar filament length was ~90 μm. Infection was systemic with mature spores produced in the midgut, nervous tissue, muscles, labial glands, gonads, tracheae, epidermis, Malpighian tubules and, most extensively, fat body tissues. The new isolate was highly pathogenic to S. litura larvae. Host specificity tests performed on 37 non-target hosts of 5 different insect orders revealed that the new isolate is pathogenic only to lepidopteran insects. We sequenced the 16S small subunit rRNA (SSU rRNA) gene of the isolate and compared it with 72 non-redundant microsporidian sequences from the GenBank. Based on the light microscopic studies and phylogenetic analyses, the new isolate is assigned to the genus Nosema. Significant differences in the SSU rRNA sequence were identified when compared with the type species Nosema bombycis and other closely related species viz., Nosema spodopterae. Structural differences were also observed in the 16S SSU rRNA between the new isolate and the two above-mentioned microsporidian pathogens. We conclude that the microsporidian isolate reported here is distinctly different from the other known species and is likely to be a new species

    The hemostatic activity of Manilkara zapota (L.) P. Royen latex associated with fibrinogenolytic activity

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    Manilkara zapota (L.) P. Royen (Sapotaceae), is widely used in traditional medicine for various ailments like, diarrhea, pulmonary diseases, piles, ulcers and to treat wounds. The present study evaluates the role of M. zapota latex in hemostasis. The processed latex named as M. zapota natant latex (MzNL), has proteins at the concentration of 8 mg/ml and showed protein bands in Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The proteolytic activity of MzNL was evaluated using casein in comparison with trypsin. The phenylmethylsulfonyl fluoride (PMSF) inhibited the protease activity indicating the possible presence of serine protease. The effect of temperature, pH and metal ions on proteolytic activity was evaluated. MzNL exhibited fibrinogenolytic activity by hydrolysing A? and B? subunits of fibrinogen. However, ? subunit remained resistant for hydrolysis. MzNL hydrolyzed all the subunits of collagen type I and IV at the concentration of 8 µg and 25 µg in 20 µl each respectively. MzNL showed procoagulant activity and is devoid of hemolytic activity. Fibrinogenolytic activity and procoagulant nature of MzNL suggests its possible role in blood coagulation that in turn restores hemostasis

    An Empirical Critique of On-Demand Routing Protocols against Rushing Attack in MANET

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    Over the last decade, researchers had  proposed numerous  mobile ad hoc routing protocols for which are operate in an on-demand way, as standard on-demand routing protocols such as AODV, DSR and TORA, etc., have been shown to often have faster reaction time and  lower overhead than proactive protocols. However, the openness of the routing environment and the absence of centralized system and infrastructure make them exposed to security attacks in large extent.  In particular, one such kind of attacks is rushing attack, which is mostly hard to detect due to their inherited properties, that alters the network statistics radically. In this paper, we modeled a rushing attack which is a powerful attack that exploits the weaknesses of the secure routing protocols. Moreover, to know the weakness and strength of these protocols, it is necessary to test their performance in hostile environments. Subsequently, the performance is measured with the various metrics, some ot them are average throughput, packet delivery ratio, average end-to-end delay and etc., to compare and evaluate their performance

    A prospective comparative study of functional outcome of distal extra articular tibia fracture fixed with intramedullary nail versus locking compression plate

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    Background: Distal tibia fractures are one of the most common long bone fractures and their management presents with a series of problems due to the soft tissue surroundings and even more at risk due to their proximity to ankle joint. In our paper we showed functional outcome of distal extra articular tibia fracture while comparing its management between intramedullary nailing and locking compression plate.Methods: There were 40 patients from November 2019 to November 2020 with distal extra articular tibia fracture. Patients were divided into 2 groups, first group included 20 patients managed with intramedullary nail and the second group included 20 patients managed with locking compression plate. Patients were followed preoperatively, intraoperatively and postoperatively for functional outcome and assessed clinically using AOFAS score and radiologically using X-ray.Results: Out of the 40 cases treated in this manner, all cases were available for the follow up for a period of 1 year. Overall results by 1 year follow up showed excellent in 7 cases (35%) good in 13 cases (65%) in nailing group and in plating group showed excellent in 4 cases (20%), good in 12 cases (60%), fair in 3 cases (15%) and poor in 1 case (5%).Conclusions: All fractures united well. Complications were encountered in 4 patients, 2 patients had superficial wound infections,1 patient had deep infection and another had persistent ankle pain in plating group and 2 patients had superficial wound infection in nailing group. No cases showed malunion or nonunion in both plating as well as nailing group

    Boondh: The journey of a raindrop in the drylands

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    This book gives you glimpses of our work in 13 project sites and also features path breaking initiatives that were successfully implemented at other sites in India

    Data Reduction Techniques for High Contrast Imaging Polarimetry. Applications to ExPo

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    Imaging polarimetry is a powerful tool for detecting and characterizing exoplanets and circumstellar environments. Polarimetry allows a separation of the light coming from an unpolarized source such as a star and the polarized source such as a planet or a protoplanetary disk. Future facilities like SPHERE at the VLT or EPICS at the E-ELT will incorporate imaging polarimetry to detect exoplanets. The Extreme Polarimeter (ExPo) is a dual-beam imaging polarimeter that currently can reach contrast ratios of 10^5, enough to characterize circumstellar environments. We present the data reduction steps for a dual-beam imaging polarimeter that can reach contrast ratios of 10^5. The data obtained with ExPo at the William Herschel Telescope (WHT) are analyzed. Instrumental artifacts and noise sources are discussed for an unpolarized star and for a protoplanetary disk (AB Aurigae). The combination of fast modulation and dual-beam techniques allow us to minimize instrumental artifacts. A proper data processing and alignment of the images is fundamental when dealing with large contrasts. Imaging polarimetry proves to be a powerful method to resolve circumstellar environments even without a coronagraph mask or an Adaptive Optics system.Comment: 9 pages, 12 Figures, Accepted for publication in A&

    Targeting ie-1 gene by RNAi induces baculoviral resistance in lepidopteran cell lines and in transgenic silkworms

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    RNA interference (RNAi)-mediated viral inhibition has been used in a few organisms for eliciting viral resistance. In the present study, we report the use of RNAi in preventing baculovirus infection in a lepidopteran. We targeted the baculoviral immediate early-1 (ie-1) gene in both a transformed lepidopteran cell line and in the transgenic silkworm Bombyx mori L. Constitutive expression of double-stranded RNA was achieved by piggyBac-mediated transformation of Sf9 cell line with a transgene encoding double-stranded ie-1 RNA (dsie-1). Strong viral repression was seen at early stages of infection but subsequent recovery of viral proliferation was observed. In contrast, the same transgene inserted into the chromosomes of transgenic silkworms induced long-term inhibition of B. mori nucleopolyhedrovirus infection, with nearly 40% protection compared with nontransgenic animals. Protection was efficient at larval stages after oral infection with occlusion bodies or hemocoel injection of budded viruses. Virus injected pupae also displayed resistance. These results show that heritable RNAi can be used to protect silkworm strains from baculovirus infection

    Online) An Open Access

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    ABSTRACT Ground water is being extracted mostly through bore wells in the area. Due to increase in number of bore wells over a period of time mostly for irrigation purpose, the depth to ground water levels have become deeper and deeper and touched more than 70 m bgl at certain locations. Ground water occurs mostly in fractured system which is in semi-confined to confined condition. The ground water is mostly suitable for domestic and irrigation purposes. The present study is an attempt to evaluate the groundwater system of Settikere area, Tumkur district. Hydrogeological investigations require an integrated approach. Though groundwater is replenish able natural resources, when withdrawals exceed the limits of dynamic recharge, it will cause irreversible damages. As in nature, South India is a hard rock terrain. In recent years, bore wells for agricultural purposes have been drilled on a massive scale by the farmers without carving for minimum interference distance to be maintained between the extraction structures. Thereby, groundwater levels are drastically affected. The present study suitable areas for groundwater potential zones in the region have been identified by using RS and GIS techniques

    Genetic improvements to the sterile insect technique for agricultural pests

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    The sterile insect technique (SIT) relies on area-wide mass-releases of sterile male pest insects, which mate with their wild counterparts and thereby cause a drop in the wild population. In order to improve SIT efficacy or to avoid potential negative effects of such releases, strains of insects have been developed by genetic means. Methods of strain improvement fall into two categories: those generated by classical genetics and those through transgenesis. Here, we describe development and successes of agriculturally important pest insect strains developed through the former, and how transgenic technology is offering a broad spectrum of potential improvements to SIT in a wider range of insects. Also discussed are future prospects and non-technical challenges faced by transgenic technology. The need for environment-friendly pest control methods in agriculture has never been more pressing. SIT and related technologies offer a solution with proven effectiveness

    A Review of the Implications of Heterozygosity and Inbreeding on Germplasm Biodiversity and Its Conservation in the Silkworm, Bombyx mori

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    Silkworm genebanks assume paramount importance as the reservoirs of biodiversity and source of alleles that can be easily retrieved for genetic enhancement of popular breeds. More than 4000 Bombyx mori L (Lepidoptera: Bombycidae) strains are currently available and these strains are maintained through continuous sibling mating. This repeated sibling mating makes the populations of each strain more homozygous, but leads to loss of unique and valuable genes through the process of inbreeding depression. Hence, it is essential to maintain a minimal degree of heterozygosity within the population of each silkworm strain, especially in the traditional geographic strains, to avoid such loss. As a result, accurate estimation of genetic diversity is becoming more important in silkworm genetic resources conservation. Application of molecular markers help estimate genetic diversity much more accurately than that of morphological traits. Since a minimal amount of heterozygosity in each silkworm strain is essential for better conservation by avoiding inbreeding depression, this article overviews both theoretical and practical importance of heterozygosity together with impacts of inbreeding depression and the merits and demerits of neutral molecular markers for measurements of both heterozygosity and inbreeding depression in the silkworm Bombyx mori
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