760 research outputs found

    Adaptive And Reliable GPS Uncertain Position Estimation an Insightful Oceanography and Geography Applications

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    Location evaluation applications are one of the most imperative services in GPS position applications. The Global Positioning Systems (GPS) is a versatile and legacy technology has been providing a reliable and accurate position of objects on Earth. The uncertain GPS position is considered an initialization parameter for many inherent systems in today’s world. This initialization position estimate has a wide variety of applications such as Coast line maps, understanding the geo-dynamical phenomena such as volcanic eruptions, earthquakes and subsequent originating source mechanisms, Mean Sea level estimation for contours of land surfaces, Oceanic en-route as well as in mobile and Vehicular technologies etc. The validation and reliability of the results of all those applications is dependent on the accuracy of the position estimate given by GPS. In this work an attempt is made to retrieve accurate and reliable position parameters from GPS by correcting the measurement errors for all the visible satellites at every epoch. The maximum and minimum pseudo ranges in L2 signal observed are 2437404.2 meters and -76295.22 meters

    Purification, physicochemical and regulatory properties of serine hydroxymethyltransferase from sheep liver

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    Serine hydroxymethyltransferase (EC 2.1.2.1) was purified from the cytosolic fraction of sheep liver by ammonium sulphate fractionation, CM-Sephadex chromatography, gel filtration using Ultrogel ACA 34 and Blue Sepharose affinity chromatography. The homogeneity of the enzyme was rigorously established by Polyacrylamide gel and sodium dodecyl sulphate-polyacrylamide gel electrophoresis, isoelectrofocusing, ultracentrifugation, immunodiffusion and Immunoelectrophoresis. The enzyme was a homotetramer with a molecular weight of 210,000 ± 5000. The enzyme showed homotropic cooperative interactions with tetrahydrofolate (nH = 2.8) and a hyperbolic saturation pattern with L-serine. At the lowest concentration of tetrahydrofolate used (0.2 mM), only 5% of the added folate was oxidized during preincubation and assay. ThenH value was independent of the time of preincubation. Preincubation of the enzyme with serine resulted in a partial loss of the cooperative interactions (nH =1.6) with tetrahydrofolate. The enzyme was regulated allosterically by interaction with nicotinamide nucleotides; NADH was a positive effector while NAD+ was a negative allosteric effector. The subunit interactions were retained even at the temperature optimum of 60‡C unlike in the case of the monkey liver enzyme, where these interactions were absent at higher temperatures. D-Cycloserine, a structural analogue of serine caused a sigmoid pattern of inhibition, in contrast with the observations on the monkey liver enzyme. Cibacron blue F3GA completely inhibited the enzyme and this inhibition could be reversed by tetrahydrofolate. Unlike in the monkey liver enzyme, NAD+ and NADH gave considerable protection against this inhibition. The sheep liver enzyme differs significantly in its kinetic and regulatory properties from the serine hydroxymethyltransferases isolated from other sources

    Water-saving Rice Production Technologies in Krishna Western Delta Command of Andhra Pradesh – An Economic Analysis

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    The economic analysis of water-saving rice production technologies, viz. system of rice intensification (SRI), semi-dry and rotational irrigation vis-à-vis farmers’ practice has been carried out based on the study executed in Modukuru pilot area of Guntur district of Andhra Pradesh. Among the three water-saving rice production technologies analyzed, the total cost of cultivation has been recorded highest in SRI (Rs 58645/ha), followed by rotational (Rs 47140/ha) and semi-dry (Rs 39321/ha). But, the per hectare yield has been found highest in SRI (6.85 t), followed by semi-dry (6.66 t) and rotational (6.2 t), inferring that all the three technologies have recorded higher yields over farmers’ practice of 5.5 t/ha. However, the net returns and B-C ratio are maximum in semi-dry (Rs 43,484/ha; 1.11), followed by rotational (Rs 30,085; 0.64) and SRI (Rs 26,466/ha; 0.45) methods. Similarly, the water-use efficiency has been found highest in SRI (8.53 kg/ ha-mm), followed by semi-dry (8.02 kg/ha-mm) and rotational (7.33 kg/ ha-mm) methods, while the water-use efficiency benefit (Rs/ha-mm) has been recorded maximum in semi-dry (52.39), followed by SRI (42.08) and rotational (35.56) methods. With the initiation of Andhra Pradesh Water Management Project, Bapatla, the area under semi-dry rice cultivation has been found increasing over a period of four years, from 0.6 ha in 2004-2005 to 22 ha in 2007 -2008.Agricultural and Food Policy,

    Relationship between morphological and amplified fragment length polymorphism (AFLP) marker based genetic distance with heterosis in hot pepper (Capsicum annuum L.)

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    Identification of potential parents that produce the hybrids with superior yield is the most important step in developing hybrids to save the substantial resources. The present study was carried out to assess the morphological and amplified fragment length polymorphism (AFLP) marker based genetic diversity, to estimate mid parent heterosis and to correlate the estimated parental genetic diversity with heterosis chilli. Five CMS B - lines and 30 testers were used for morphological and AFLP marker genetic divergence analysis. 150 hybrids were synthesized through Line × Tester (5 × 30) mating design and were used to estimate the mid-parent heterosis for nine characters at two locations. 35 parents were examined for nine morphological traits and were grouped in to six clusters. These parents were also examined for eight AFLP primers combinations and were grouped into seven clusters. More than 50% of hybrids showed significant mid-parent heterosis for both green and red fruit yield plant-1. Hence, there is a much potential for development of good yielding hybrids. The positive significant correlation was found between morphological and AFLP marker distance of the parents with heterosis for plant height (r = 0.17 and 0.38), green fruit yield plant-1 (r = 0.19 and 0.25) and red fruit yield plant-1 (r = 0.20 and 0.34); however, the correlation coefficients were not strong in these traits. Genetic distance between parents was not strong enough to predict the performance of the hybrids and proved to be of no predictive value.Keywords: Correlation, molecular markers, genetic diversity, chill

    Nitrogen and potassium nutrition of French basil (Ocimum basilicum Linn.)

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    Studies were undertaken on red sandy loam soil (Kandiustalf) in a semi-arid tropical climateat Bangalore (Karnataka) to find out the effect of fertilizer application in influencing oilproduction, quality and soil fertility in French basil (Ocimum basilicum). The study showedthat application of nitrogen (up to 100 kg ha-1) increased herb and essential oil yields in themain crop, first ratoon and second crop while potassium application (up to 80 kg ha-1)increased the yields in the second ratoon and second crop suggesting that soil potassiumdepletion occurred with time.  Nitrogen application increased methyl chavicol (by 4.1%) anddecreased linalool (by 14.2%) contents in basil oil. Yield increases were accompanied by higherremoval of nitrogen, phosphorus and potassium from soil (by 247%, 23% and 94%,respectively) by the crop and lower amounts of exchangeable potassium (by 37.8 %) in soil.Due to the depletion of soil potassium, interactions between nitrogen and potassium weresignificant in the second crop of basil. Application of 100 kg nitrogen ha-1 and 80 kg potassiumha-1 gave optimum yield and quality of oil. &nbsp

    Role of crop competition in managing weeds in rice, wheat, and maize in India: A review

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    In India, the three staple food crops viz., rice, wheat, and maize, contribute more than four-fifths of the total food grain production. Among the several factors limiting their productivity, weeds account for about 40%. In order to meet the requirements of growing population, it is essential to improve productivity by reducing such unwarranted losses. Managing weeds with crop competition is an eco-friendly approach. Once the mechanisms of competition are understood, further improvements in weed control could be gained by manipulating other agronomic practices. The choice of cultivars, crop density, seeding rate, direction of planting, and intercropping could be exploited to enhance crop competitiveness against weeds. The variation in competitiveness and weed suppression among cultivars has been documented in rice, and to a lesser extent in wheat and maize. Research has demonstrated that the integration of crop competitiveness with other methods, such as the use of herbicides and manual weeding, is successful in managing weeds. However, in India, greater efforts are needed to exploit crop competitiveness for managing weeds in rice, wheat and maize. The success of these approaches relies on proper understanding of the biology and ecology of weeds, to identify weak points in their life cycle

    Comparative evaluation of H1 receptor blocking activity and safety of newer H1antagonist mizolastine with loratadine and placebo: a randomized double blind three way crossover study

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    Background: Histamine is a naturally occurring body constituent synthesized from L-histidine by histidine decarboxylase enzyme that is expressed throughout the body including central nervous system neurons, gastric mucosa, mast cells and basophils. The objective of this study was to compare the pharmacological activity and safety of 10 mg mizolastine, 10 mg loratadine and placebo in healthy human volunteers.Methods: After randomly allocating the 3 drugs, a battery of psychometric tests was done. Histamine prick test for wheal and flare reaction, VAS for sedation and itch followed by salivary flow test were done. Vitals were recorded. The subjects were randomized to receive either of the treatment in a cross-over manner with washout period of 7 days. The wheal and flare areas were recorded before and after 1,2,4,8, and 24 hours.Results: Mean inhibition on histamine induced wheal and flare response with mizolastine was highly significant as compared to placebo from 1 hour onwards (p<0.001) with maximum inhibition of 98.1±1.8% at 4 hours and of 85.1±24.8percent at 8 hours, for wheal and flare, respectively. The mean inhibition on histamine induced response with loratadine was significant from 2 hours (p<0.05) for wheal area and 1 hour onwards up to 24 hours (P<0.01) for flare area with the maximum inhibition of 56.2±31.6 percent and 60.1±14.2percent at 8hours, respectively. Mean inhibition on histamine induced itch with mizolastine was also significant from 4 hours onwards and persisted up to 24 hours (p<0.05) with maximum inhibition of 58.6±54.2% at 8 hours for the itch response, unlike loratidine. There was no significant change in mean effect on sedation assessed on a VAS of 0-100 mm. There was no significant change in psychomotor functions, salivary flow or vital parameters. All were well tolerated.Conclusions: Mizolastine has good antihistaminic activity than loratadine. Neither drug causes any psychomotor impairment or has anti-cholinergic action

    Calcretes in the Thar desert: genesis, chronology and palaeoenvironment

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    The calcretes in the Thar desert occur in a variety of settings, including the piedmonts, sheetwash aggraded plains; and this study adds calcretes in regolith and colluvio-alluvial plains to the group of settings in which calcretes occur in the region. Field logs, morphological details and analytical data such as petrographic, cathodoluminescence and geochemical characteristics are described along with a discussion on their implications. Sand dunes and sandy plains dating to &lt;20 ka have weakly developed calcretes. The better-developed calcrete horizons occur in piedmonts, interdunes or in areas that have sufficient groundwater. Deep sections in the region show phases of calcrete development in aeolian sand aggradation at ~150, ~100, ~60 and 27-14 ka. The extensive sheetwash plains have mature calcretes and date to mid-Pleistocene. Our studies indicate that these calcretes represent a hybrid process, where carbonate enrichment of the originally calcareous host occurred due to periodically raised groundwaters, and its differentiation into nodules occurred under subaerial environment i.e., after recession of groundwater. Deep sections also show a stack of discrete calcretes that developed in individual aggradation episodes with hiatuses as indicated by ESR dating results. Nodules display a multiplicity of carbonate precipi tation events and internal reorganization of calcitic groundmass. The process is accompanied by degradation and transformation of unstable minerals, particularly clays and with a neosynthesis of palygorskite. The ancient calcretes are dated from the beginning of the Quaternary to ~600 ka and show more evolved morphologies marked by brecciation, dissolution, laminar growth on brecciated surfaces, pisolites and several generations of re-cementation. Mica/chlorite schists and such other rocks are particularly vulnerable to replacement by carbonate. In an extreme case, replacement of quartzose sandstone was observed also. The presence of stretches of alluvio-colluvial plains in an area presently devoid of drainage bespeaks of occasional high-energy fluvial regime, under a semi-arid climate. The mid-Pleistocene period saw a shift towards more arid climate and this facilitated sheetwash aggradation. Finally, during the late Pleistocene, aggradation of aeolian sands indicated a progressively drier climate. However, this does not find its reflection in stable isotope data. The amount of carbonate in the form of calcretes is substantial. The present studies indicate that aeolian dust or rainwater are minor contributors to the carbonate budget. A more important source was provided by the pre-existing calcretes in the sheetwash aggraded plains and detrital carbonate in the aeolian sediments. The original source of carbonate in the region, however, remains unresolved and will need further investigations. Electron spin resonance protocols for the dating of calcretes were developed as a part of this study and the results accorded well with geological reasoning
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