1,492 research outputs found

    Lunar, diurnal and tidal periodicity in relation to the prawn abundance and migration in the Godavari estuarine systems

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    Preliminary investigations to study the lunar, diurnal and tidal periodicity in abundance and migrations of prawns were made in the Bairavapalam distributary of the Goutami branch of the Godavari estuary during the period of November 1961 to July 1962. The study was based on observation of the catches of a stake net (bag net) operated near the mouth of the estuary. Records of the catches were maintained tidewise daily. Comparative estimates of abundance were made on the basis of catch per hour's operation. It was generally observed that the catches were higher during the darker half of the month than in the brighter fortnight. The landings during low tides were generally higher than those during high tides and usually heavier catches were made during nocturnal low tides than during the day low tides. A continuous inward and outward (immigration and emigration) movement of prawns of all size groups was observed in the estuary from November to July. In general, more penaeid prawns were found to be immigrating at dawn than at dusk. Similarly, the number of emigrants was also found to be generally higher during the new moon period than during the full moon. Metapenaeus monoceros showed an almost distinct nocturnal periodicity in migration, while no such periodicity was observed, distinctly, in other species. In the case of Penaeus indicus the movement of migrants was prolonged. In M. brevicornis the migrants were scarce till March and thereafter increased numerically. The migrant forms of Metapenaeus dobsoni continued to be abundant till May with peak periods in January and February. The migratory pattern of Metapenaeus affinis was similar to that of Metapenaeus brevicornis, though the migrants of the former species appeared a month earlier than the latter. Intensive studies over extended areas for longer periods are required to understand clearly the migratory pattern of the various species. The phenomenon of immigration of prawns can be clearly understood only by vital staining or tagging studies. Perhaps the emigrants might be returning with the succeeding changing life. To verify this, laboratory experiments, by vital stains, were conducted. The marked specimens, if released during the low tides on a large scale, may be recaptured during the subsequent high tides and the duration also may be calculated. At least some percentage of the emigrants remains in the sea for maturity and breeding

    Enhancement of magnetoresistance in manganite multilayers

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    Magnanite multilayers have been fabricated using La0.67Ca0.33MnO3 as the ferromagnetic layer and Pr0.7Ca0.3MnO3 and Nd0.5Ca0.5MnO3 as the spacer layers. All the multilayers were grown on LaAlO3 (100) by pulse laser deposition. An enhanced magnetoresistnace (defined (RH- R0)/R0) of more than 98% is observed in these multilayers. Also a low field magnetoresistance of 41% at 5000 Oe is observed in these multilayer films. The enhanced MR is attributed to the induced double exchange in the spacer layer, which is giving rise to more number of conducting carriers. This is compared by replacing the spacer layer with LaMnO3 where Mn exists only in 3+ state and no enhancement is observed in the La0.67Ca0.33MnO3 / LaMnO3 multilayers as double exchange mechanism can not be induced by external magnetic fields.Comment: 13 pages, 5 Figure

    Influence of sericin in alleviating the hydrogen peroxide induced oxidative stress in silkworm Bombyx mori: role of the amino acids

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    Sericin is an important peptide derived from silk fibre spun by the silkworm Bombyx mori and has various biological activities. The aim of the present study was to characterize the major constituents of sericin that are providing cytoprotective effect against hydrogen peroxide-induced cell damage in midgut epithelial cells and hemocytes of silkworm. Extracted sericin was subjected to LCMS analysis for amino acid composition. Isolated cells of midgut and hemocytes were incubated with sericin or with mixture of serine and aspartic acid prior to suboptimal concentration of hydrogen peroxide treatment. Sericin as well as amino acid mixture reduced the activity of antioxidant enzymes triggered by hydrogen peroxide, inhibited oxidative derivatives such as protein carbonyl and malondialdehyde and increased antioxidant capacity in both the cells studied. Furthermore, sericin and amino acid mixture significantly decreased intracellular reactive oxygen species as assessed by fluorescent detection. These results suggest that major constituent amino acids of sericin defend midgut epithelial cells and hemocytes against oxidative damage by scavenging reactive oxygen species rather than activating antioxidant enzyme system thereby inhibiting cell damage

    5-(4-Chloro­phen­yl)-1-methyl-3-oxocyclo­hexa­necarbonitrile

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    In the title mol­ecule, C14H14ClNO, the cyclo­hexane ring adopts a chair conformation. The cyano group and the methyl group have axial and equatorial orientations, respectively. The benzene ring has an equatorial orientation. A C—H⋯π inter­action involving the benzene ring is found in the crystal structure

    Developmental features of biomedical bibliographic databases

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    The genesis of bibliographic databases can be traced to the abstracting and indexing (A&I) periodicals. The Journal Des Scavans published in 1665 did contain abstracts of articles, but the formal abstracting journal began in 1820 (English) and in 1830 (German). The growth of primary periodicals required libraries to subscribe to A&I services to search for papers scattered in different journals as it was not possible to acquire all the primary periodical titles. The electronic versions of A&I periodicals started appearing in 1960s with emergence of database concept. The Chemical Titles and the MEDLARS are considered to be the earliest bibliographic databases. The Silver Platter is believed publish first biomedical CD-ROM database the MEDLINE with search facility � SPIRS. The growth and development of bibliographic databases has continued since then and enters the digital era to serve the users. The present paper theoretically examines EMBASE, PubMed and IndMed databases. © 2017, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved

    Structural heat treatments against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae): effect of flour depth, life stage and floor.

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    The effect of high temperatures (50-60°C) and two levels of sanitation (~0.5 and 43 g of flour), on mortality of eggs, young larvae, old larvae, pupae, and adults of the red flour beetle, Tribolium castaneum, were evaluated during heat treatment of a pilot flour mill at Kansas State University. The mill was heated once during 13-14 May 2009 and once during 25-26 August 2009. Each of the heat treatments lasted 24 h. Bioassay boxes, with life stages of T. castaneum and temperature sensors confined in small compartments, were placed in 25 locations across all five mill floors. Temperature data showed that the mean time to 50°C based on the two treatments ranged from 10.39 to 17.18 h, and the mean time above 50°C ranged from 6.01 to 13.63 h. The mean maximum temperatures attained ranged from 50.7 to 61.4°C. In general, temperatures were lower in compartments with 43 g of flour when compared with compartments with 0.5 g of flour. Temperatures were also lower on the first floor than on the remaining floors. In box bioassays, essentially none of the life stages survived the 24 h heat treatment (99-100% mortality), except on the first floor. The survival of insects, especially on the first floor, is related to how quickly temperatures reached 50°C and how long temperatures were held between 50 and 60°C, and the maximum temperatures attained at a given location. There were only small differences in mortality between the two levels of sanitation. These results show that heat treatment of flour mills can control all life stages of T. castaneum in 24 h. Keywords: Tribolium castaneum, Heat treatment, Sanitation, Life stages, Methyl bromide alternative

    A New Approach for SAR Image Denoising

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    In synthetic aperture radar (SAR)  imaging, the transmitted pulses from space born antenna interacts with ground objects and returned energy or back scattered energy will be collected  to get backscattered image. In this process, a speckle noise will be added because of the coherent imaging system and  makes the study of SAR images very difficult. For better SAR image processing, the speckle has to be removed in the initial stages of processing  and maintain all texture features efficiently. The BM3D method is generally considered as state of art method in denoising of SAR images. In this paper, it is proposed a technique to despeckle the speckle noise to the maximum extent while maintaining the edge characteristics

    Enhancement of magnetoresistance in manganite multilayers

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    Magnanite multilayers have been fabricated using La0.67Ca0.33MnO3 as the ferromagnetic layer and Pr0.7Ca0.3MnO3 and Nd0.5Ca0.5MnO3 as the spacer layers. All the multilayers were grown on LaAlO3 (100) by pulse laser deposition. An enhanced magnetoresistnace (defined (RH- R0)/R0) of more than 98% is observed in these multilayers. Also a low field magnetoresistance of 41% at 5000 Oe is observed in these multilayer films. The enhanced MR is attributed to the induced double exchange in the spacer layer, which is giving rise to more number of conducting carriers. This is compared by replacing the spacer layer with LaMnO3 where Mn exists only in 3+ state and no enhancement is observed in the La0.67Ca0.33MnO3 / LaMnO3 multilayers as double exchange mechanism can not be induced by external magnetic fields.Comment: 13 pages, 5 Figure

    Drug utilization study in ischaemic heart disease in a tertiary care hospital, Mangalore, India

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    Background: The study of drug utilization is a component of a medical audit and periodic evaluation need to be done to enable suitable modifications in prescription of drugs to increase the therapeutic benefit and decrease the adverse effects. When new drugs are used additional information on safety and efficacy may be generated. Ischaemic heart disease (IHD) is a condition in which there is an inadequate supply of blood and oxygen to a portion of the myocardium. Medications for IHD include anti-platelet therapy, nitrates, statins, ACE inhibitors, beta blockers, CCB’s, diuretics.Methods: The study was carried out at cardiology department of K. S. Hegde Charitable Hospital for a period of one year from January 2015, and relevant retrospective data were also collected from hospital records for period pertaining to one year from 1/1/2013.Results: We assessed discharge summaries of 950 patients and found that majority of patients were males than females. The highest number of patients were in the age group of 51-60 years. Polypharmacy has been observed in our study. The average number of days spent by the patients in the hospital was 3.5 days. None of the drugs were prescribed using generic names, all the drugs (100%) were prescribed in brand names only. Common co-morbidities associated with IHD were hypertension and diabetes. Most commonly prescribed drugs for IHD were Aspirin, followed by Atorvastatin, Clopidogrel, and Nitrates.Conclusions: In our study, on analysing the drug prescription data it was observed that there was no statistically significant change in drug utilization between the two years
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