215 research outputs found

    The Maximal Invariance Group of Newtons's Equations for a Free Point Particle

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    The maximal invariance group of Newton's equations for a free nonrelativistic point particle is shown to be larger than the Galilei group. It is a semi-direct product of the static (nine-parameter) Galilei group and an SL(2,R)SL(2,R) group containing time-translations, dilations and a one-parameter group of time-dependent scalings called {\it expansions}. This group was first discovered by Niederer in the context of the free Schr\"odinger equation. We also provide a road map from the free nonrelativistic point particle to the equations of fluid mechanics to which the symmetry carries over. The hitherto unnoticed SL(2,R)SL(2, R) part of the symmetry group for fluid mechanics gives a theoretical explanation for an observed similarity between numerical simulations of supernova explosions and numerical simulations of experiments involving laser-induced implosions in inertial confinement plasmas. We also give examples of interacting many body systems of point particles which have this symmetry group.Comment: Plain TeX File: 15 Page

    Length-weight relationship of selected commercially important marine fishes from east coast of India

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    The paper deals with length-weight relationship (LWR) of selected commercially important marine fishes from the east-coast of India. Samples were collected fortnightly from experimental fishing using trawl operated at depth up to 70 M off Vishakhapatnam coast on the east-coast of India during 2015-17. Measurements of total length (TL) (nearest to 0.1 cm) and body weight (nearest to 0.1 g) of individual fish were taken. The LWR showed good fit with r2 values ranging from 0.975 for Lepturacanthus savala Cuvier, 1829 to 0.999 for Upeneus vittatus Forsskål, 1775. The ‘b’ values ranged from 2.618 for Photopectoralis bindus Valenciennes, 1835 to 3.186 for L. savala Cuvier, 1829

    Expert system for insect pests of agricultural crops

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    Insect pests are one of the major constraints in agricultural production, processing and storage. The damage caused by insect pests in agriculture is substantial and farmers have to incur huge monetary losses. Management of insect pests is therefore the only solution to save the crops and other valuable inputs that goes into agricultural production. Vast information on insect pests of different crops and their management is available at different sources. Based on this knowledge, a rule based expert system for insect pests of different agricultural crops was developed. The system is supported by a database containing information about 15 crops with a total of 95 insect pests affecting those crops. The expert system was evaluated following the conventional expert system evaluation methodology. This system provides information and solutions to farmers, scientists, extension workers involved in agriculture development and education. Using this system one can identify the pest and diagnose the problem for speedy and effective decision making in pest management to avoid losses

    के मा प्रौ सं के विशाखपट्टणम अनुसंधान केंद्र का मात्स्यिकी क्षेत्र में योगदान

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    के मा प्रौ सं के विशाखपट्टणम अनुसंधान केंद्र का मात्स्यिकी क्षेत्र में योगदा

    Rhizobium Radiobacter-Induced Peritonitis: A Case Report and Literature Analysis

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    Rhizobium radiobacter (R. radiobacter) is a gram-negative bacterium, primarily a soil contaminant and rarely pathogenic to humans. Only a few cases of peritonitis secondary to R. radiobacter have been reported worldwide. A 66-year-old male with end-stage renal disease who was on peritoneal dialysis (PD) developed R. radiobacter-induced peritonitis. We have treated the infection successfully with intraperitoneal antibiotics and managed to keep his PD catheter intact without interruption in PD treatment. More prolonged antibiotic therapy and frequent clinical follow-up is required to treat this infection. Better clinician awareness is needed to prevent this rare infection

    In-orbit Performance of UVIT on ASTROSAT

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    We present the in-orbit performance and the first results from the ultra-violet Imaging telescope (UVIT) on ASTROSAT. UVIT consists of two identical 38cm coaligned telescopes, one for the FUV channel (130-180nm) and the other for the NUV (200-300nm) and VIS (320-550nm) channels, with a field of view of 28 arcminarcmin. The FUV and the NUV detectors are operated in the high gain photon counting mode whereas the VIS detector is operated in the low gain integration mode. The FUV and NUV channels have filters and gratings, whereas the VIS channel has filters. The ASTROSAT was launched on 28th September 2015. The performance verification of UVIT was carried out after the opening of the UVIT doors on 30th November 2015, till the end of March 2016 within the allotted time of 50 days for calibration. All the on-board systems were found to be working satisfactorily. During the PV phase, the UVIT observed several calibration sources to characterise the instrument and a few objects to demonstrate the capability of the UVIT. The resolution of the UVIT was found to be about 1.4 - 1.7 arcsecarcsec in the FUV and NUV. The sensitivity in various filters were calibrated using standard stars (white dwarfs), to estimate the zero-point magnitudes as well as the flux conversion factor. The gratings were also calibrated to estimate their resolution as well as effective area. The sensitivity of the filters were found to be reduced up to 15\% with respect to the ground calibrations. The sensitivity variation is monitored on a monthly basis. UVIT is all set to roll out science results with its imaging capability with good resolution and large field of view, capability to sample the UV spectral region using different filters and capability to perform variability studies in the UV.Comment: 10 pages, To appear in SPIE conference proceedings, SPIE conference paper, 201

    Kinetics of the long-range spherical model

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    The kinetic spherical model with long-range interactions is studied after a quench to T<TcT < T_c or to T=TcT = T_c. For the two-time response and correlation functions of the order-parameter as well as for composite fields such as the energy density, the ageing exponents and the corresponding scaling functions are derived. The results are compared to the predictions which follow from local scale-invariance.Comment: added "fluctuation-dissipation ratios"; fixed typo

    Distribution, diversity, length-weight relationship and recruitment pattern of deep-sea finfishes and shellfishes in the shelf-break area off southwest Indian EEZ

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    The results of an exclusive fishing cruise, No. 241, undertaken by FORV Sayar Sampada (Ministry of Earth Sciences) during January-February 2006, in the shelf-break area (500-1000m depth) in the southwest region of Indian EEZ (Lat.Q-16" and Long. 72"-75"46) are presented. Bottom trawling was conducted at 33 stations. A total catch of 1795 kg was realised, out of which the discards formed 31 1 kg. A variety of non-conventional finfishes (77 species) and shellfishes (shrimps 8 species, crabs 3 species, one species of lobsterette) have been recorded. Depth-wise 235m zone indicated the maximum catch. The total catch during the entire cruise was dominated by Psenopsis ryanra. The various population parameters such as La, K, total mortality (Z), natural mortality (M), fishing mortality (F), exploitation ratio (E), recruitment pattern and length-weight relationship of some of the important species have been worked out. In most of the deep-sea fishes, the recruitment appeared to take place almost throughout the year and showed great similarity among the various species except Luciobrotula bartschi. Presently, all these resources remain unexploited, except the shrimps. The trawlers based at Cochin, Quilon and Munambam have been exploiting the deep-sea shrimp resources like the red-ring Arbreus alcocki from the Quilon Bank and other similar areas of< west coast for the last five years. Interestingly Psenopsis cyanea has been found to occur as bye-catch in these fishing operations. Therefore, these two species showed higher fishing mortality compared to practically nil value in other finfishes and shellfishes. The occurrence of the deep-sea glass sponge, Hyalonema sp. off Mangalore is also reported. Bio-silica, extracted from this sponge, has a vide range of applications in the medical field from novel biomaterials for bone replacements to the stabilization of tissue. Most of the resources being nonconventional there is need to evolve new processing methods, product diversification and develop export avenues to make deep-sea fishing venture a success. Inventorisation of the deep-sea biodiversity and preparation of fishery atlas also merit serious consideration

    Heat shock proteins in stabilization of spontaneously restored sinus rhythm in permanent atrial fibrillation patients after mitral valve surgery

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    A spontaneously restored sinus rhythm in permanent atrial fibrillation patients has been often observed after mitral valve (MV) surgery, but persisting duration in sinus rhythm varies from patient to patient. Heat shock proteins (Hsps) may be involved in pathogenesis of atrial fibrillation. We hypothesized that stabilization of restored sinus rhythm is associated with expression of Hsps in the atria. To test this hypothesis, clinical data, biopsies of right atrial appendage, and blood samples were collected from 135 atrial fibrillation patients who spontaneously restored sinus rhythm after conventional isolated MV replacement. Comparison was made between patients who had recurrence of atrial fibrillation within 7 days (AF) vs. patients with persisted sinus rhythm for more than 7 days (SR). Results showed that SR patients had higher activity of heat shock transcription factor 1 (HSF1) as well as upregulated expressions of heat shock cognate 70, Hsp70, and Hsp27 in the tissues. The activation of HSF1–Hsps pathway was associated with less-aggressive pathogenesis as reflected by lower rates of myolysis, apoptosis, interstitial fibrosis, and inflammation in SR patients. However, Hsp60 was lower in both tissue and plasma in SR patients, and was positively correlated with apoptosis, interstitial fibrosis, and inflammation. These findings suggest that the Hsps play important roles in stabilization of restored sinus rhythm after MV surgery by inhibiting AF-related atrial remodeling and arrhythmogenic substrates in atrial fibrillation patients. Low circulating Hsp60 levels preoperatively might predict a stable spontaneously restored sinus rhythm postoperatively

    LPS-induced delayed preconditioning is mediated by hsp90 and involves the heat shock response in mouse kidney.

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    INTRODUCTION: We and others demonstrated previously that preconditioning with endotoxin (LPS) protected from a subsequent lethal LPS challenge or from renal ischemia-reperfusion injury (IRI). LPS is effective in evoking the heat shock response, an ancient and essential cellular defense mechanism, which plays a role in resistance to, and recovery from diseases. Here, by using the pharmacological Hsp90 inhibitor novobiocin (NB), we investigated the role of Hsp90 and the heat shock response in LPS-induced delayed renal preconditioning. METHODS: Male C57BL/6 mice were treated with preconditioning (P: 2 mg/kg, ip.) and subsequent lethal (L: 10 mg/kg, ip.) doses of LPS alone or in combination with NB (100 mg/kg, ip.). Controls received saline (C) or NB. RESULTS: Preconditioning LPS conferred protection from a subsequent lethal LPS treatment. Importantly, the protective effect of LPS preconditioning was completely abolished by a concomitant treatment with NB. LPS induced a marked heat shock protein increase as demonstrated by Western blots of Hsp70 and Hsp90. NB alone also stimulated Hsp70 and Hsp90 mRNA but not protein expression. However, Hsp70 and Hsp90 protein induction in LPS-treated mice was abolished by a concomitant NB treatment, demonstrating a NB-induced impairment of the heat shock response to LPS preconditioning. CONCLUSION: LPS-induced heat shock protein induction and tolerance to a subsequent lethal LPS treatment was prevented by the Hsp90 inhibitor, novobiocin. Our findings demonstrate a critical role of Hsp90 in LPS signaling, and a potential involvement of the heat shock response in LPS-induced preconditioning
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