1,259 research outputs found

    Different mechanisms of energy coupling for transport of various amino acids in cells of Mycobacterium phlei

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    Whole cells of Mycobacterium phlei were shown to actively accumulate proline, leucine, lysine, tryptophan, histidine, glutamine, and glutamic acid to different steady state levels. The transport of proline, in contrast to that of other amino acids, was found to be insensitive to various respiratory inhibitors, e.g. cyanide, arsenate, azide, and sulfhydryl reagents. However, oxygen was an obligatory requirement for the uptake of proline, as well as for the other amino acids. The results indicate that the energy requirements for proline uptake are different from those of other amino acids. In contrast to the system from Escherichia coli, the mode of energy transduction for the uptake of proline, glutamine, and glutamic acid is different even though these amino acids are shock resistant in the M. phlei system

    Effect of phospholipase A on the structure and functions of membrane vesicles from Mycobacterium phlei

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    The phospholipid composition of the electron transport particles and coupling factor-depleted electron transport particles of Mycobacterium phlei are the same, but they differ in contents. The accessibility of partially purified phospholipase A to these membrane phospholipids was found to be different. Treatment of membranes of Mycobacterium phlei with phospholipase A impairs the rate of oxidation as well as phosphorylation. The inhibition of phosphorylation can be reversed by washing the membranes with defatted bovine serum albumin. The reconstitution of membrane-bound coupling factor-latent ATPase activity to phospholipase A-treated depleted electron transport particles and their capacity to couple phosphorylation to oxidation of substrates remained unaffected after phospholipase A treatment. However, the pH gradient as measured by bromthymol blue was not restored after reconstitution of phospholipase A-treated depleted electron transport particles with membrane-bound coupling factor-latent ATPase. These findings show that the phosphorylation coupled to the oxidation of substrates can take place without a pronounced pH gradient in these membrane vesicles. The dye 1-anilino-8-naphthalene sulfonic acid (ANS) exhibited low levels of energized and nonenergized fluorescence in phospholipase A-treated membranes. This decrease in the level of ANS fluorescence in phospholipase A-treated membranes was found to be directly related to the amount of phospholipids cleaved. The decrease in the energy-dependent ANS response in phospholipase A-treated electron transport particles, as compared with untreated electron transport particles, was shown to be a result of a change in the apparent Kd of the dye-membrane complex, and of a decrease in the number of irreversible or slowly reversible binding sites, with no change in the relative quantum efficiency of the dye. The decrease in ANS fluorescence in phospholipase A-treated particles appears to be due to a decrease in the hydrophobicity of the membranes

    Improvement in short-circuited coaxial flange for evaluating microwave superconducting properties at low temperature

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    5-10In the present study, we have proposed an improvement in terms of the determination of S-parameters of an open flange from its characteristic impedance and propagation constant. With the help of these S-parameters, the actual reflection coefficient of YBCO films deposited on LAO substrate is obtained from the measured reflection coefficient. The surface impedance of three YBCO films is obtained in the range of few ohms in the frequency range from 1 GHz to 40 GHz. The surface resistance of the films reduces at liquid nitrogen temperature, i.e., 77 K, whereas, the surface reactance slightly increases due to kinetic inductance. The conductivity and skin depth are also determined to validate the improvement in the method

    A simple method to estimate the loading effects of Al/Si on the characteristic impedance of multilayer microstrip line

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    The present study aims to experimentally determine the microwave transmission and reflection properties of aluminum thin film grown on silicon using sputtering. A simple microstrip line based structure has been used for the microwave characterization in the frequency range 10 MHz to 26.5 GHz. Complex S-parameter measurements reveal only small differences on silicon loading and aluminum/silicon loading in comparison to the microstrip line. The characteristic impedance (Z) of the microstrip line loaded with silicon and with aluminum/silicon have been obtained corresponding to the length of the loadings using two port microwave analysis. Comparison of loaded microstrip line with no loading shows large changes in the real part well as imaginary part of the characteristic impedance in the frequency range less than 10 GHz. Percentage changes in the real (Z) and imaginary (Z) have been found as ± 40% and ± 10% in average, respectively, for silicon loading in comparison to the no loading case, whereas these changes have been found to be below ±5% for aluminium/silicon loading, thus these smaller changes suggest the similar responses for aluminium/silicon loading and no loading. The results reveal that the propagation can be restored with the application of aluminum with any semiconductor or dielectric as loading on the microstrip line, which shows its potential to be explored for making an individual microwave component

    Improvement in short-circuited coaxial flange for evaluating microwave superconducting properties at low temperature

    Get PDF
    In the present study, we have proposed an improvement in terms of the determination of S-parameters of an open flange from its characteristic impedance and propagation constant. With the help of these S-parameters, the actual reflection coefficient of YBCO films deposited on LAO substrate is obtained from the measured reflection coefficient. The surface impedance of three YBCO films is obtained in the range of few ohms in the frequency range from 1 GHz to 40 GHz. The surface resistance of the films reduces at liquid nitrogen temperature, i.e., 77 K, whereas, the surface reactance slightly increases due to kinetic inductance. The conductivity and skin depth are also determined to validate the improvement in the method

    Higher yields and profits from new crop rotations permitting integration of mediculture with agriculture in the Indo-Gangetic plains

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    The results of a survey conducted in 100 villages of 7 districts located in Uttar Pradesh in the central Indo-Gangetic plains on the land cropping pattern and profits to the farmers per unit land and area are presented. It is shown that sugarcane is cultivated in about 19.5% of the land. Rice remains the principal kharif crop in the area, occupying about 76% of land. Conventional rice-wheat/Brassica/legume, rice-potato and rice-mint rotations benefitted farmers to the extent of roughly Rs 30,000 ha−1 year−1. Introduction of new rotations based upon newly available short duration Kosi variety of mint is permitting practice of rice-wheat/Brassica/legume-mint and rice-potato-mint rotations, bringing a profit of approximately Rs 61,000 ha−1 year−1 to the farmers of the area. Future prospects of integration of short duration medicinal and aromatic crops (mediculture) between food grain crops (agriculture) like the above, for the development of agriculture, industry and employment are discussed

    Cost-effectiveness of magnetic resonance imaging in cervical clearance of obtunded blunt trauma after a normal computed tomographic finding

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    © 2018 American Medical Association. All rights reserved. IMPORTANCE Magnetic resonance imaging (MRI) continues to be performed for cervical clearance of obtunded blunt trauma, despite poor evidence regarding its utility after a normal computed tomographic (CT) finding. OBJECTIVE To evaluate the utility and cost-effectiveness of MRI vs no follow-up after a normal cervical CT finding in patients with obtunded blunt trauma. DESIGN, SETTING AND PARTICIPANTS This cost-effectiveness analysis evaluated an average patient aged 40 years with blunt trauma from an institutional practice. The analysis used a Markov decision model over a lifetime horizon from a societal perspective with variables from systematic reviews and meta-analyses and reimbursement rates from the Centers for Medicare & Medicaid Services, National Spinal Cord Injury Database, and other large published studies. Data were collected from the most recent literature available. INTERVENTIONS No follow-up vs MRI follow-up after a normal cervical CT finding. RESULTS In the base case of a 40-year-old patient, the cost of MRI follow-up was 14185withahealthbenefitof24.02qualityadjustedlifeyears(QALY);thecostofnofollowupwas14 185 with a health benefit of 24.02 quality-adjusted life-years (QALY); the cost of no follow-up was 1059 with a health benefit of 24.11 QALY, and thus no follow-up was the dominant strategy. Probabilistic sensitivity analysis showed no follow-up to be the better strategy in all 10 000 iterations. No follow-up was the better strategy when the negative predictive value of the initial CT was relatively high (\u3e98%) or the risk of an injury treated with a cervical collar turning into a permanent neurologic deficit was higher than 25% or when the risk of a missed injury turning into a neurologic deficit was less than 58%. The sensitivity and specificity of MRI were varied simultaneously in a 2-way sensitivity analysis, and no follow-up remained the optimal strategy. CONCLUSIONS AND RELEVANCE Magnetic resonance imaging had a lower health benefit and a higher cost compared with no follow-up after a normal CT finding in patients with obtunded blunt trauma to the cervical spine, a finding that does not support the use of MRI in this group of patients. The conclusion is robust in sensitivity analyses varying key variables in the model. More literature on these key variables is needed before MRI can be considered to be beneficial in the evaluation of obtunded blunt trauma

    The Nexus of Political Violence and Economic Deprivation: Pakistani Migrants Disrupt the Refugee / Migrant Dichotomy

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    There have been discussions about how the labels “forced migrants,” related to political violence, and “voluntary migrants,” associated with economic factors, cannot be understood in categorical ways. However, there has been less focus on the specificities of the asylum-migrant nexus from the perspective of migrants. This essay discusses how such factors intersect as understood by Pakistani migrants residing in Germany. Through enacting a critical view of Pakistan, the migrants demonstrate how aspects of corruption, economic deprivation, and political violence come to intersect so that is becomes impossible to classify asylum seekers in binary/dichotomous ways
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