5,992 research outputs found

    Whistlers detected and analyzed by Automatic Whistler Detector (AWD) at low latitude Indian stations

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    Abstract Recently, at three Indian low latitude stations: Varanasi (geomag. lat. 14°55′N, geomag. long. 153°54′E, L: 1.078), Allahabad (geomag. lat. 16.05°N; geomag. long. 155.34°E, L: 1.081) and Lucknow (geomag. lat. 17.6°N, geomag. long. 154.5°E, L: 1.104) an Automatic Whistler Detector (AWD) has been installed in December, 2010 for detection and analysis of whistlers. This instrument automatically detects and collects statistical whistlers data for the investigation of whistlers generation and propagation. Large numbers of whistlers have been recorded at Varanasi and Allahabad during the year 2011 which is analyzed in the present study. Different types of whistlers have been recorded at Varanasi and Allahabad. The correlation between recorded whistlers and causative lightning strikes were analyzed using data provided by World-Wide Lightning Location Network (WWLLN). We observed that for both the stations more than 50% of causative sferics of whistlers were observed to match closely with the times of WWLLN detected lightning strikes within the propagation times of causative tweeks. All of these lightning strikes originated from the region within 500–600 km radius circle from the conjugate point of Varanasi and Allahabad supports the ducted propagation at low latitude stations. The dispersion of the observed whistlers varies between 8 and 18 s1/2, which shows that the observed whistlers have propagated in ducted mode and whole propagation path of whistlers lies in the ionosphere. The ionospheric columnar electron contents of these observed whistlers vary between 13.21 TECU and 56.57 TECU. The ionospheric parameters derived from whistler data at Varanasi compare well with the other measurements made by other techniques

    Numerical and Experimental Modeling of the Static Response of Simply Supported Thin-Walled Box Girder Bridges

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    This paper presents numerical and experimental modeling of the static response of simply supported thin-walled reinforced concrete box girder bridges. The work is executed to verify the validity of software developed by the authors for the finite strip analysis of continuous thin-walled box girder bridges and also to observe the effect of flange width on the static response of these type of structural elements under service load from experimental and numerical studies. The laboratory load/deformation relationship is presented in the form of deflection ratios that is displayed alongside the finite strip analysis results of the same loading condition. The results obtained from the laboratory experiment and the software showed very good agreement and are, averagely, 21.5% and 19.5% higher than that of the beam theory solution respectively. Verification of the software with published solutions is also conducted. The results from the developed software showed very good agreement with literature in terms of deflection and stress distributions. These results suggest that the effect of shear deformation, which is more significant on deflection than on stresses, increases with increase in flange width and that the developed software is capable of capturing the general behavior of thin-walled box girder bridges.http://dx.doi.org/10.4314/njt.v34i4.

    Severe malaria - a case of fatal Plasmodium knowlesi infection with post-mortem findings: a case report.

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    BACKGROUND: Zoonotic malaria caused by Plasmodium knowlesi is an important, but newly recognized, human pathogen. For the first time, post-mortem findings from a fatal case of knowlesi malaria are reported here. CASE PRESENTATION: A formerly healthy 40 year-old male became symptomatic 10 days after spending time in the jungle of North Borneo. Four days later, he presented to hospital in a state of collapse and died within two hours. He was hyponatraemic and had elevated blood urea, potassium, lactate dehydrogenase and amino transferase values; he was also thrombocytopenic and eosinophilic. Dengue haemorrhagic shock was suspected and a post-mortem examination performed. Investigations for dengue virus were negative. Blood for malaria parasites indicated hyperparasitaemia and single species P. knowlesi infection was confirmed by nested-PCR. Macroscopic pathology of the brain and endocardium showed multiple petechial haemorrhages, the liver and spleen were enlarged and lungs had features consistent with ARDS. Microscopic pathology showed sequestration of pigmented parasitized red blood cells in the vessels of the cerebrum, cerebellum, heart and kidney without evidence of chronic inflammatory reaction in the brain or any other organ examined. Brain sections were negative for intracellular adhesion molecule-1. The spleen and liver had abundant pigment containing macrophages and parasitized red blood cells. The kidney had evidence of acute tubular necrosis and endothelial cells in heart sections were prominent. CONCLUSIONS: The overall picture in this case was one of systemic malaria infection that fit the WHO classification for severe malaria. Post-mortem findings in this case were unexpectedly similar to those that define fatal falciparum malaria, including cerebral pathology. There were important differences including the absence of coma despite petechial haemorrhages and parasite sequestration in the brain. These results suggest that further study of knowlesi malaria will aid the interpretation of, often conflicting, information on malaria pathophysiology in humans

    Isolating silkworm genomic DNA without liquid nitrogen suitable for marker studies

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    Genomic DNA was isolated from posterior silk gland of silkworms, Antheraea assama. Absolute alcohol was used as tissue fixing solution instead of grinding in liquid nitrogen, which yielded high molecular weight DNA (>40 kb). Samples yielded similar amount of DNA when fixed in absolute alcohol (400 μmg/g of silk gland tissue) and ground in liquid nitrogen (456 μmg/g of silk gland tissue). RAPD profile of the isolated DNA revealed high degree of polymorphism. The silkworms were analysed using 50 random primers among which 36 polymorphic primers gave 309 amplicons. The average amplicons per primer found to be 8.58 and 94.82% amplicons were polymorphic. Cluster analysis based on Jaccard’s similarity coefficients resulted in the formation of two main clusters with S9 on one cluster and the remaining strains on the other cluster. Jaccard’s similarity coefficients ranged from 0.122 to 0.863 indicating a high level of genetic diversity within muga silkworm collection. Isolated DNA was also suitable for cloning and restriction enzyme digestion. This method does not require liquid nitrogen for fixation, grinding or storage at -80°C, making it advantageous over other common protocols.Key words: Genomic, silkworms, muga, molecular breeding

    Evaluating the Environmental and Public Health Inference of COVID-19 Lockdowns: A Longitudinal Study of Air Quality in Delhi and National Capital Region (NCR)

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    The COVID-19 virus has had a huge impact on communities around the world, leading to lockdowns to reduce the spread of the virus. This research paper aims to provide a detailed comparison of the impact of the lockdown on air quality in Delhi's National Capital Region (NCR). It also aims to assess the short- and long-term effects of the lockdown on residents of the Delhi National Capital Territory by analyzing various air pollutants. The research will compare pre- and post-closure conditions and explore differences in the impact of different demographics and health groups. Findings from this study can inform policymakers, urban planners, and community health officials in developing effective strategies to prevent and improve health in similar situations in the future. This research paper explores changes in air pollution, specifically PM2.5, PM10, NO2, and ozone over the four years from 2019 to 2023. These pollutants show differences and changes in air quality over tim
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