1,082 research outputs found

    Traditional Uses of Some Medicinal Plants by tribals of Gangaraju Madugula Mandal of Visakhapatnam District, Andhra Pradesh

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    During the years 2007-2008 several field trips were conducted to document the ethnomedicinal remedies for 47 diseases with 90 plant species of Angiosperms from three major tribes viz: Bagatas, Konda Doras and Valmikis who have been residing in Gangaraju Madugula Mandal of Visakhapatnam district. The plants were deposited as herbarium specimens in Andhra University, Visakhapatnam, India

    ‘Foresting’ the grassland: Historical management legacies in forest-grassland mosaics in southern India, and lessons for the conservation of tropical grassy biomes

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    Colonial encounters with tropical ecosystems were primarily driven by profit-oriented management practices; witness the extensive network of timber and forestry practices that were set up across colonial India. In contrast, the colonial engagement with the montane forest-grassland mosaics of the higher reaches of the Western Ghats in southern India was marked by intensive investment in vegetation management by colonial foresters that yielded no profits. In this archival study, we trace the history of extensive vegetation transformation in this landscape from the early nineteenth to the early twentieth century. We show how the misperception that the grasslands within this mosaic must have resulted from tree felling, fire-setting and buffalo grazing by indigenous communities led colonial foresters into a century-long effort at ‘foresting’ the grasslands, primarily through large-scale planting of exotic tree species. These efforts persisted despite economic losses and ecological evidence that native tree seedlings planted in the grasslands repeatedly failed to establish. These policies continued unabated into the late twentieth century in newly independent India. Today, the once picturesque landscapes of these ancient forest-grassland mosaics are diminished by large-scale plantations of exotic species. Some of these species have become invasive and pose significant threats to the remnant natural grasslands. While this historical narrative is set in the forest-grassland mosaics of southern India, it finds striking parallels in the current day, with grasslands and savannas globally threatened by the misperception that they are ‘degraded ecosystems’ that can be ‘forested’ or converted to other ‘productive’ land uses. We suggest that this case history portends the potential fates of many of earth's threatened tropical grasslands and savannas

    Novel cruzain inhibitors for the treatment of Chagas' disease.

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    The protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas' disease, affects millions of individuals and continues to be an important global health concern. The poor efficacy and unfavorable side effects of current treatments necessitate novel therapeutics. Cruzain, the major cysteine protease of T. cruzi, is one potential novel target. Recent advances in a class of vinyl sulfone inhibitors are encouraging; however, as most potential therapeutics fail in clinical trials and both disease progression and resistance call for combination therapy with several drugs, the identification of additional classes of inhibitory molecules is essential. Using an exhaustive virtual-screening and experimental validation approach, we identify several additional small-molecule cruzain inhibitors. Further optimization of these chemical scaffolds could lead to the development of novel drugs useful in the treatment of Chagas' disease

    Prospective, randomized, and comparative study of efficacy of ivermectin, benzyl benzoate 25%, permethrin 5% and gamma benzene hexachloride 1% in the treatment of uncomplicated scabies

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    Background: Scabies is an infectious and contagious human skin disease. The aim of the study was to study the efficacy and safety of four different treatment modalities in clinically diagnosed cases of scabies of single dose of oral ivermectin and commonly used topical scabicidal agent’s benzyl benzoate 25% (BB), permethrin 5% and gamma benzene hexachloride 1% (GBHC).Methods: This study was carried out in the Department of Dermatology, Andhra Medical College, Visakhapatnam. 200 patients diagnosed of scabies were included in the study during the period from August 2013 to July 2014. The percentage of improvement was compared between four groups. Intergroup comparison between two groups was done Chi square test.Results: In the present study a greater number of patients were students (54.5%). Subsidence of lesion and itching with oral ivermectin given as a single dose (200 μg/kg body weight) was 45 (90%) and 44 (88%), with topical permethrin 5% lotion single application 48 (96%), 47 (94%), with topical GBHC 1% lotion 40 (80%) patients, 38 (76%). Topical application of BB lotion 25% was 38 (76%), and 36 (72%) at fourth week.Conclusions: In the present study permethrin 5% cream was found to be more effective among topical agents. Both BB and GBHC 1% lotion are being inexpensive and they can be used as an alternative treatment in developing country like India

    Ants, fire, and bark traits affect how African savanna trees recover following damage

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    Bark damage resulting from elephant feeding is common in African savanna trees with subsequent interactions with fire, insects, and other pathogens often resulting in tree mortality. Yet, surprisingly little is known about how savanna trees respond to bark damage. We addressed this by investigating how the inner bark of marula (Sclerocarya birrea), a widespread tree species favoured by elephants, recovers after bark damage. We used a long‐term fire experiment in the Kruger National Park to measure bark recovery with and without fire. At 24 months post‐damage, mean wound closure was 98, 92, and 72%, respectively, in annual and biennial burns and fire‐exclusion treatments. Fire exclusion resulted in higher rates of ant colonization of bark wounds, and such ant colonization resulted in significantly lower bark recovery. We also investigated how ten common savanna tree species respond to bark damage and tested for relationships between bark damage, bark recovery, and bark traits while accounting for phylogeny. We found phylogenetic signal in bark dry matter content, bark N and bark P, but not in bark thickness. Bark recovery and damage was highest in species which had thick moist inner bark and low wood densities (Anacardiaceae), intermediate in species which had moderate inner bark thickness and wood densities (Fabaceae) and lowest in species which had thin inner bark and high wood densities (Combretaceae). Elephants prefer species with thick, moist inner bark, traits that also appear to result in faster recovery rates

    Adaptation Reduces Variability of the Neuronal Population Code

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    Sequences of events in noise-driven excitable systems with slow variables often show serial correlations among their intervals of events. Here, we employ a master equation for general non-renewal processes to calculate the interval and count statistics of superimposed processes governed by a slow adaptation variable. For an ensemble of spike-frequency adapting neurons this results in the regularization of the population activity and an enhanced post-synaptic signal decoding. We confirm our theoretical results in a population of cortical neurons.Comment: 4 pages, 2 figure

    Mobile agent based knowledge management in education system

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    This paper looks into delivering a Mobile Agent Based Knowledge Management System in Education System. Firstly the paper looks at reviewing the issues that are occurring in Knowledge Management System. A proposed system structure is made to show how a mobile agent works and is used in education system. XML Metadata with Aglet is used here for faster retrieval of data. A security framework is also presented to look at protecting a distributed network from malicious mobile agents.We also recommended an intelligent search module for the agent to search the required data

    A thorny issue: Woody plant defence and growth in an East African savanna

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    Recent work suggests that savanna woody plant species utilise two different strategies based on their defences against herbivory; a low nutrient/high chemical defence strategy and a nutrition paired with mostly architectural defences strategy. The concept that chemical and structural defences can augment each other and do not necessarily trade-off has emanated from this work. In this study, we examine woody plant defence strategies, how these respond to herbivore removal and how they affect plant growth in an East African savanna. At three paired long-term exclosure sites with high browser and mixed-feeder densities at Mpala Ranch, Kenya, we investigated: (a) whether defences employed by the dominant fine- and broad-leaved woody savanna species form defence strategies and if these align with previously proposed strategies, (b) how nine key plant defence traits respond to herbivore removal and (c) how effective the different defence strategies are at protecting against intense herbivory (by measuring plant growth with and without herbivores present). We identified three defence strategies. We found a group (a) with high N, short spines and high N-free secondary metabolites, a group (b) with high N, long spines and low N-free secondary metabolites and a group (c) with moderate N, no spines and low N-free secondary metabolites (most likely defended by unmeasured chemical defences). Structural defences (spine length, branching) were generally found to be induced by herbivory, leaf available N increased or did not respond, and N-free secondary metabolites decreased or did not respond to herbivory. Species with long spines combined with increased “caginess” (dense canopy architecture arising from complex arrangement of numerous woody and spiny axis categories) of branches, maintained the highest growth under intense browsing, compared to species with short spines and high N-free secondary metabolites and species with no spines and low N-free secondary metabolites. Synthesis. At our study site, structural traits (i.e. spines, increased caginess) were the most inducible and effective defences against intense mammalian herbivory. We propose that high levels of variability in the way that nutrient and defence traits combine may contribute to the coexistence of closely related species comprising savanna woody communities
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