83 research outputs found

    High Performance Power Spectrum Analysis Using a FPGA Based Reconfigurable Computing Platform

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    Power-spectrum analysis is an important tool providing critical information about a signal. The range of applications includes communication-systems to DNA-sequencing. If there is interference present on a transmitted signal, it could be due to a natural cause or superimposed forcefully. In the latter case, its early detection and analysis becomes important. In such situations having a small observation window, a quick look at power-spectrum can reveal a great deal of information, including frequency and source of interference. In this paper, we present our design of a FPGA based reconfigurable platform for high performance power-spectrum analysis. This allows for the real-time data-acquisition and processing of samples of the incoming signal in a small time frame. The processing consists of computation of power, its average and peak, over a set of input values. This platform sustains simultaneous data streams on each of the four input channels.Comment: 5 pages, 3 figures. Published in the Proceedings of the IEEE International conference on Reconfigurable Computing and FPGAs (ReConFig 2006). Article also available at http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4100006&isnumber=409995

    A charge reversal differentiates (p)ppGpp synthesis by monofunctional and bifunctional Rel proteins

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    A major regulatory mechanism evolved by microorganisms to combat stress is the regulation mediated by (p)ppGpp (the stringent response molecule), synthesized and hydrolyzed by Rel proteins. These are divided into bifunctional and monofunctional proteins based on the presence or absence of the hydrolysis activity. Although these proteins require Mg2+ for (p)ppGpp synthesis, high Mg2+ was shown to inhibit this reaction in bifunctional Rel proteins from Mycobacterium tuberculosis and Streptococcus equisimilis. This is not a characteristic feature in enzymes that use a dual metal ion mechanism, such as DNA polymerases that are known to carry out a similar pyrophosphate transfer reaction. Comparison of polymerase Polβ and RelSeq structures that share a common fold led to the proposal that the latter would follow a single metal ion mechanism. Surprisingly, in contrast to bifunctional Rel, we did not find inhibition of guanosine 5′-triphosphate, 3′-diphosphate (pppGpp) synthesis at higher Mg2+ in the monofunctional RelA from Escherichia coli. We show that a charge reversal in a conserved motif in the synthesis domains explains this contrast; an RXKD motif in the bifunctional proteins is reversed to an EXDD motif. The differential response of these proteins to Mg2+ could also be noticed in fluorescent nucleotide binding and circular dichroism experiments. In mutants where the motifs were reversed, the differential effect could also be reversed. We infer that although a catalytic Mg2+ is common to both bifunctional and monofunctional proteins, the latter would utilize an additional metal binding site formed by EXDD. This work, for the first time, brings out differences in (p)ppGpp synthesis by the two classes of Rel proteins

    Stress Indices for Non-Radial Branch Connections for Piping

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    AbstractProcedure for determining the stress indices for non radial branch connections is discussed. A typical non radial branch connection, commonly used in the piping system of FRFCF is modeled and analyzed using CAST-3M for calculation various stress indices for the connection. B2 Stress indices for the branch connection for in plane bending and out of plane bending is arrived at based on nonlinear finite element analysis and limit load approach. K2 factor is determined using Peterson's curve, based on the curvature at the junction of run pipe and branch connection. Stress index C2 and the stress intensification factor i are determined by employing the relations of these factors with other stress indices

    Heralding Extramedullary Blast Crisis: Horner’s Syndrome with Brachial Plexopathy in a Patient with Chronic Myelogenous Leukemia

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    Chronic myelogenous leukemia (CML) blast crisis is an ominous clinical event that is challenging to treat. This can develop at extramedullary sites rarely and is defined as the infiltration of blasts outside the bone marrow irrespective of proliferation of blasts within the bone marrow. We aim to report an unusual clinical presentation characterized by Horner’s syndrome, ipsilateral arm weakness, and cervical lymphadenopathy as the first signs of extramedullary blast crisis in a CML patient. To the best of our knowledge, the extramedullary locations involving the brachial plexus along with cervicothoracic paraspinal chloroma have not been previously reported in the literature

    Central Pontine and Extrapontine Myelinolysis: The Great Masquerader—An Autopsy Case Report

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    Central pontine myelinolysis is a demyelinating disorder characterized by the loss of myelin in the center of the basis pontis usually caused by rapid correction of chronic hyponatremia. The clinical features vary depending on the extent of involvement. Demyelination can occur outside the pons as well and diagnosis can be challenging if both pontine and extrapontine areas are involved. We herein report a case of myelinolysis involving pons, lateral geniculate bodies, subependymal region, and spinal cord. To the best of our knowledge, this case represents the second case of spinal cord involvement in osmotic demyelination syndrome and the first case of involvement of thoracic region of spinal cord

    Heart rate and blood pressure variability in patients with myasthenia gravis

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    This cross-sectional case control study included subjects aged between 18 and 65 years with diagnosis of myasthenia gravis (MG) in Osserman′s Stage I and Stage IIa and those in remission with positive and negative acetylcholine receptor antibody (AChRAb). They were evaluated for heart rate variability (HRV) and other conventional autonomic functions. Patients with co-morbidities that can affect autonomic nervous system were excluded. Repetitive nerve stimulation test (RNST), nerve conduction test, AChRAb assay, and computerized tomography (CT) of chest were done in all the patients. All patients of MG who fulfilled the inclusion criteria had a minimum drug-free period of 6 h which was followed by HRV and other conventional tests. Thirty subjects fulfilling study criteria and an equal number of age and gender-matched healthy subjects were enrolled as controls. Autonomic function tests revealed significant changes in HRV (both time and frequency domain) parameters suggestive of parasympathetic deficiency as well as shifting of sympathovagal balance towards raised sympathetic tone. With regards to conventional autonomic function tests, there was statistically significant decrease in values of heart rate-based tests as well as blood pressure-based test (isometric handgrip test) in study group compared with controls, again indicative of significant parasympathetic deficiency and minimal sympathetic deficiency. We conclude that in MG, cholinergic transmission is affected more diffusely than previously thought

    Analiza i statystyczne opracowanie fizyczno-chemicznych właściwości wody z estuarium Narmada, Gujarat, Indie

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    Investigations on physicochemical parameters (temperature, pH, salinity, dissolved oxygen), including dissolved nutrients (PO4-P, NO3-N, SiO4-Si) and chlorophyll-a were carried out in the water off the mouth of the Narmada estuary from July 2008 to June 2009. The multivariate statistics and principal component analysis applied to the datasets, indicated two factors during the whole study period influencing variability in the water to the extent of 72%. Principal axis factoring and alpha factoring have been used to observe the mode of association of parameters and their interrelationships, for evaluating water quality. The results indicated the addition of phosphates and silicates to the coastal water by the Narmada estuary from natural sources during study period. The study indicated that the Narmada estuary adds sufficiently well-oxygenated, nutrient-rich water to the coastal region.Analizę parametrów fizyczno-chemicznych (temperatura, pH, zasolenie, tlen rozpuszczony), stężenia pierwiastków biogennych (PO4-P, NO3-N, SiO4-Si) i chlorofilu prowadzono w wodach estuarium Narmada od lipca 2008 do czerwca 2009. Statystyka wielowymiarowa i analiza głównych składowych, zastosowana do zbioru wyników, wskazała dwa czynniki, które w 72% odpowiadały za zmienność składu chemicznego wody w całym okresie badań. Do oceny jakości wody zastosowano analizę czynnikową celem określenia powiązań między parametrami i ich wzajemnych zależności. Wyniki pokazały, że w okresie badawczym estuarium Narmada dostarczało do wód przybrzeżnych fosforany i krzemiany pochodzące z naturalnych źródeł. Przeprowadzone badania dowodzą, że estuarium Narmada zasila strefę brzegową w dobrze natlenione i bogate w pierwiastki biogenne wody

    An Assessment of the Accumulation Potential of Pb, Zn and Cd by Avicennia marina (Forssk.) Vierh. in Vamleshwar Mangroves, Gujarat, India

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    The study deals with the accumulation of Pb, Zn and Cd in an important mangrove species, Avicennia marina (Forssk.) Vierh., in the Vamleshwar mangrove ecosystem, near Narmada estuary, West coast of Gujarat, India with height differences of 0.5, 1.5, 2.5 meters and carried out under field conditions during October, 2009. The site was located on 21�30�11.55�� N latitude and 72�43�53.68�� E longitude. Mangrove receives heavy metal pollution from upstream areas of Narmada estuary and highly populated settlements. However, little is known about the capacity of mangrove plants to take up and store heavy metals in them. Water, sediment and plant parts such as roots, stems and leaves were analyzed for finding the trace metal accumulation of different height groups by Inductive Coupled Plasma Analyser (ICPA). Amount of the content of metals found in the water, sediment and plant parts were in the order of Pb>Zn>Cd. The average contents of heavy metals in the waters were 57.83 mg l-1 for Pb, 3.89 83 mg l-1 for Zn and 0.42 mg l-1 for Cd. It was observed that the average contents of Pb (73.6 mg l-1), Zn (8.1 mg l-1) and Cd (0.73 mg l-1) in the sediments were below the critical soil concentrations. The concentrations of heavy metals in different parts of Avicennia marina were in the order Roots>stem>leaf except for Cd, but Cd found higher in leaf. The ranges of the content of heavy metals in plants were 18.5-102.2 mg l-1 for Pb, 3.5-19.5 mg l-1 for Zn and 0.2-4.1 mg l-1 for Cd. The concentrations of all heavy metals in Avicennia marina except Pb were falling within the normal range and were much more in the plants have the highest height. The present study has shown the potential of Avicennia marina as a phytoremediation species for selected heavy metals in many mangrove ecosystems

    Nutrient Dynamics in an Avicennia marina (Forsk.) Vierh., Mangrove Forest in Vamleshwar, Gujarat, India

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    The study was carried out to determine the nutrient budget of plants, sediments and nutrient dynamics in an Avicennia marina (Forsk.) Vierh., dominated forest in Vamleshwar near Narmada estuary, West Coast of Gujarat for a period of one year from November 2008 to October 2009. The average tree height of the mangrove is 1.5 to 2 m without much vertical stratification. Allometric methodology was used to measure the biomass, and yield a figure of 86.47 t ha-1 and the litter fall rate amounted to 2.9 t ha-1. Nutrient stocks of N, P and K in this mangrove were 137.05, 14.38 and 241.29 kg ha-1, with an annual accumulation of 55.74, 12.38 and 83.94 kg ha-1, and an annual return of 51.30, 10.83 and 13.52 kg ha-1, respectively, in the form of litter. The annual uptake for N, P and K were 61.04, 14.28 and 97.46 kg ha-1, and turnover rates of N, P and K were estimated at 3, 6 and 14 years, respectively, for the study period. Flow coefficients, which reveal the dynamic processes of nutrients between mangrove plants and sediments, are also explained. The present study concluded that the A. marina dominated mangrove plantation is more efficient in nutrient use and conservation
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