Borneol Dehydrogenase from Pseudomonas sp. Strain TCU-HL1 Catalyzes the Oxidation of (+)-Borneol and Its Isomers to Camphor

PubMed Central

Tsang, Hoi-Lung; Huang, Jui-Lin; Lin, Yu-Hsuan; Huang, Kai-Fa; Lu, Pei-Luen; Lin, Guang-Huey; Khine, Aye Aye; Hu, Anren

2016-01-01

ABSTRACT Most plant-produced monoterpenes can be degraded by soil microorganisms. Borneol is a plant terpene that is widely used in traditional Chinese medicine. Neither microbial borneol dehydrogenase (BDH) nor a microbial borneol degradation pathway has been reported previously. One borneol-degrading strain, Pseudomonas sp. strain TCU-HL1, was isolated by our group. Its genome was sequenced and annotated. The genome of TCU-HL1 consists of a 6.2-Mbp circular chromosome and one circular plasmid, pTHL1 (12.6 kbp). Our results suggest that borneol is first converted into camphor by BDH in TCU-HL1 and is further decomposed through a camphor degradation pathway. The recombinant BDH was produced in the form of inclusion bodies. The apparent Km values of refolded recombinant BDH for (+)-borneol and (−)-borneol were 0.20 ± 0.01 and 0.16 ± 0.01 mM, respectively, and the kcat values for (+)-borneol and (−)-borneol were 0.75 ± 0.01 and 0.53 ± 0.01 s−1, respectively. Two plant BDH genes have been reported previously. The kcat and kcat/Km values of lavender BDH are about 1,800-fold and 500-fold lower, respectively, than those of TCU-HL1 BDH. IMPORTANCE The degradation of borneol in a soil microorganism through a camphor degradation pathway is reported in this study. We also report a microbial borneol dehydrogenase. The kcat and kcat/Km values of lavender BDH are about 1,800-fold and 500-fold lower, respectively, than those of TCU-HL1 BDH. The indigenous borneol- and camphor-degrading strain isolated, Pseudomonas sp. strain TCU-HL1, reminds us of the time 100 years ago when Taiwan was the major producer of natural camphor in the world. PMID:27542933

Magnitude of crustal shortening and structural framework of the easternmost Himalayan orogen, northern Indo-Burma Ranges of northeastern India

NASA Astrophysics Data System (ADS)

Haproff, P. J.; Yin, A.

2016-12-01

Along-strike variation in crustal shortening throughout the Himalayan orogen has been attributed to (1) diachronous, eastward-increasing convergence, or (2) localized controls including pre-collisional stratigraphic configuration and climate. In this study, we present new geologic maps and balanced cross-sections across the easternmost segment of the Himalayan orogen, the N-S-trending N. Indo-Burma Ranges of northeastern India. First order structures are NE-dipping, km-wide ductile thrust shear zones with mylonitic fabrics indicating top-to-the SW motion. Major structures include the Mayodia klippe and Hunli window, generated during folding of the SW-directed Tidding thrust and duplexing of Lesser Himalayan rocks (LHS) at depth. Reconstruction of two balanced cross-sections yields minimum shortening estimates of 70% (48 km) and 71% (133 km), respectively. The widths of the orogen for each transect are 21 km and 54 km, respectively. Our percent strain values are comparable to that of western Arunachal Himalaya, reflecting eastward-increasing strain due to counterclockwise rotation of India during convergence or along-strike variation in India's subduction angle. However, shortening magnitudes much less than that of the Sikkim (641 km), Bhutan (414-615 km), and western Arunachal Himalaya (515-775 km) could signal eastward increasing shortening of a unique Himalayan stratigraphic framework, evidenced by few GHC rocks, absence of Tethyan strata, and an extensive subduction mélange and forearc complex.

The vertical distribution of HCl in the stratosphere

NASA Technical Reports Server (NTRS)

Raper, O. F.; Farmer, C. B.; Toth, R. A.; Robbins, B. D.

1977-01-01

The vertical distribution of HCl in the stratosphere has been measured from infrared solar absorption spectra recorded with a balloon-borne interferometer. The flights were made in September, 1975, and May, 1976 at float altitudes of 40 km and 37 km, respectively, near Palestine, Texas. Concentration profiles derived from the data show an increase from 0.6 ppbv at 20 km to 1.7 plus or minus .5 ppbv in the region of 37 km. Above 37 km, the data permit only the total abundance to be determined; this value is found to be equivalent to 1.6 plus or minus .6 ppbv if the gas were uniformly mixed. The results from the two flights are closely similar, and no significant seasonal variation in the HCl concentrations can be discerned. The balloon data are consistent with the profile in the 14-21 km altitude region of the stratosphere reported earlier from U-2 observations.

Balloon borne Antarctic frost point measurements and their impact on polar stratospheric cloud theories

NASA Technical Reports Server (NTRS)

Rosen, James M.; Hofmann, D. J.; Carpenter, J. R.; Harder, J. W.; Oltmans, S. J.

1988-01-01

The first balloon-borne frost point measurements over Antarctica were made during September and October, 1987 as part of the NOZE 2 effort at McMurdo. The results indicate water vapor mixing ratios on the order of 2 ppmv in the 15 to 20 km region which is somewhat smaller than the typical values currently being used significantly smaller than the typical values currently being used in polar stratospheric cloud (PSC) theories. The observed water vapor mixing ratio would correspond to saturated conditions for what is thought to be the lowest stratospheric temperatures encountered over the Antarctic. Through the use of available lidar observations there appears to be significant evidence that some PSCs form at temperatures higher than the local frost point (with respect to water) in the 10 to 20 km region thus supporting the nitric acid theory of PSC composition. Clouds near 15 km and below appear to form in regions saturated with respect to water and thus are probably mostly ice water clouds although they could contain relatively small amounts of other constituents. Photographic evidence suggests that the clouds forming above the frost point probably have an appearance quite different from the lower altitude iridescent, colored nacreous clouds.

Kicks of magnetized strange quark stars induced by anisotropic emission of neutrinos

NASA Astrophysics Data System (ADS)

Ayala, Alejandro; Manreza Paret, D.; Pérez Martínez, A.; Piccinelli, Gabriella; Sánchez, Angel; Ruíz Montaño, Jorge S.

2018-05-01

We study the anisotropic neutrino emission from the core of neutron stars induced by the star's magnetic field. We model the core as made out of a magnetized ideal gas of strange quark matter and implement the conditions for stellar equilibrium in this environment. The calculation is performed without resorting to analytical simplifications and for temperature, density, and magnetic field values corresponding to typical conditions for a neutron star's evolution. The anisotropic neutrino emission produces a rocket effect that contributes to the star's kick velocity. We find that the computed values for the kick velocity lie within the range of the observed values, reaching velocities of the order of ˜1000 km s-1 for magnetic fields between 1015-1018 G and radii of 20 to 5 km, respectively.

Phenytoin intoxication during concurrent diazepam therapy

PubMed Central

Rogers, Howard J.; Haslam, Robert A.; Longstreth, James; Lietman, Paul S.

1977-01-01

Phenytoin elimination is a saturable process obeying Michaelis-Menten kinetics. Plasma phenytoin levels are not related linearly to dose, and small changes in enzyme activity produced by concurrent drug therapy could alter plasma levels. Two cases of phenytoin intoxication associated with simultaneous administration of diazepam are reported. Intravenous phenytoin infusions were given and the apparent Km and Vmax computed from the resulting plasma phenytoin levels. In one case `Km' and `Vmax' were 0.8 μmol/1 and 1.3 μmol/1/hour respectively during concurrent diazepam administration, and 50.3 μmol/1 and 4.4 μmol/1/hour after discontinuation of diazepam. In the second case phenytoin infusion with diazepam gave `Km' and `Vmax' values of 0.012 μmol/1 and 0.95 μmol/1/hour. Without diazepam these were 28.8 μmol/1 and 0.92 μmol/1/hour respectively. PMID:599366

A spectral analysis of Deneb (A2 Iae)

NASA Astrophysics Data System (ADS)

Albayrak, B.

2000-12-01

This study presents a detailed model atmosphere abundance analysis of Deneb which was performed using Kurucz LTE ATLAS9 model atmospheres. The atmospheric parameters were determined from Mg I/II and Fe I/II equilibrium, and by fitting the Hgamma profile and optical region spectrophotometry. The compromise values which best satisfy these criteria are T_eff = 9000 K and log g = 1.45. The Mg I, Mg II, Si II, Ti II, Cr II, Fe I, and Fe II lines yield microturbulences of 3.60, 6.50, 8.50, 8.00, 11.90, 3.60, and 10.40 km s-1, respectively. An average microturbulence of 7 km s-1 was used for the other atomic species. From a comparision of the synthetic spectrum with the observations, the best value for the rotational velocity is v sin i = 25 km s-1, and for the macroturbulent velocity is zeta = 14 km s-1, which are similar to those of some earlier derived values. Also, the individual spectrograms have a range of radial velocity variation of ~ 15 km s-1 which is approximately equal to macroturbulent velocity. These values of the macroturbulence and the range of radial velocity variation are close to the sum of the amplitudes (10.44 km s-1) of all the pulsation periods found by Lucy (\\cite{lucy}), who also suggested that the surface motions of the atmosphere of Deneb can be identified with macroturbulence. Deneb showed a definite helium underabundance with a well determined He/H value = 0.071. The CNO values (C being mildly deficient, N being in moderate excess, and an O being slightly deficient) are consistent with the mixing of the CNO-cycled products into the surface layers from the processed materials presumably dredged-up from the interior. Aluminium is mildly deficient by ~ 0.24 dex with respect to solar value, while sulfur is moderately underabundant by ~ 0.43 dex in Deneb. Mg and Si have the solar abundances. The metal abundances (Ca to Ni) tend to be greater than solar except for Sc which is slightly deficient. The heavy elements abundances (Sr, Y, and Zr) are all greater than solar. These abundance patterns conform to the common tendency seen with other normal Population I A supergiants found by Venn (\\cite{venna}). The rare-earth elements (Ba, La, and Eu) which have been unexplored in other Galactic early A-type supergiants are significantly overabundant relative the Sun. Based on data obtained at the Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, National Research Council of Canada. Table A.1 is only available electronically with the On-Line publication at http://link.springer.de/link/service/00230/

The Hack's law applied to young volcanic basin: the Tahiti case

NASA Astrophysics Data System (ADS)

Ye, F.; Sichoix, L.; Barriot, J.; Serafini, J.

2010-12-01

We study the channel morphology over the Tahiti island from the Hack’s law perspective. The Hack’s law is an empirical power relationship between basin drainage area and the length of its main channel. It had also been shown that drainage area becomes more elongate with increasing basin size. For typical continental basins, the exponent value lies between 0.47 for basins larger than 260,000 km2 and 0.7 for those spanning less than 20,720 km2 (Muller, 1973). In Tahiti, we extracted 27 principal basins ranging from 7 km2 to 90 km2 from a Digital Terrain Model of the island with a 5 m-resolution. We demonstrate that the Hack’s law still apply for such small basins (correlation coefficient R2=0.7) with an exponent value being approximately 0.5. It appears that the exponent value is influenced by the local geomorphic condition, and does not follow the previous study results (the exponent value decreases with increasing drainage area.) Our exponent value matches the result found w.r.t. debris-flow basins of China for drainage areas less than 100 km2 (Li et al., 2008). Otherwise, the young volcanic basins of Tahiti do not become longer and narrower with increasing basin size (R2=0.1). Besides, there is no correlation between the basin area and the basin convexity (R2=0). This means that there is no statistical change in basin shape with basin size. We present also the drainage area-slope relationship with respect to sediment or transport-limited processes. Key words: Hack’s law, channel morphology, DTM

Correlation between microturbulence and nonradial pulsations in iota Herculis

NASA Astrophysics Data System (ADS)

Said, N. M. M.; Razelan, M. M.; Chong, H. Y.; Aziz, A. H. A.; Zainuddin, M. Z.

2015-04-01

In this work, we study the correlation between microturbulence and nonradial pulsations of iota Herculis a B3 IV-typed star. This research is conducted using 144 spectra of iota Herculis taken from the ELODIE archive data (May 17 to 21, 1995) and 47 spectra from the archive data of Ritter Observatory (February 6, 1994 to October 30, 1995). The spectra of the ELODIE and the Ritter Observatory are analysed using the rvidlines subroutine of IRAF software to obtain the value of nonradial pulsations velocities (which represented by the heliocentric radial velocities). The heliocentric radial velocities (HRV) of iota Herculis obtained from ELODIE and Ritter Observatory are from -13.66 km s-1 to -17.09 km s-1 and -13.60 km s-1 to -29.70 km s-1, respectively. The microturbulent velocities are determined by using the important equation of the full width at half-maximum (FWHM) of the line profile for Doppler broadening. The value varies from 3.44 km s-1 to 5.32 km s-1 for the ELODIE data whereas the Ritter Observatory data are from 1.50 km s-1 to 5.83 km s-1. Both curves of HRV and microturbulent velocities show an identical pattern which the HRV curves will increase when the microturbulent velocities curves increase and vice versa. We propose the correlation between microturbulence and nonradial pulsations in this star is due to the gravity waves which drive the nonradial pulsations and subsequently induce the microturbulence.

Isostatic response of the Alula-Fartak and Owen transforms in the Eastern Gulf of Aden and the adjoining Arabian Sea

NASA Astrophysics Data System (ADS)

Radhakrishna, M.; Searle, R. C.

2006-04-01

The Alula-Fartak and Owen transforms are the active parts of major fracture zones with a distinct topographic expression in the Eastern Gulf of Aden and the Arabian Sea, respectively. While the Alula-Fartak transform offsets the Sheba Ridge by about 180 km and is associated with a broad steep-sided valley with a relief of nearly 3.5 km, the Owen transform offsets the Carlsberg Ridge by nearly 300 km and is associated with a broad step-like valley surrounded by deeper water depths. The gravity and topography data along several profiles selected across these two transforms have been analysed using cross-spectral analysis in order to investigate their isostatic compensation. The observed admittance estimates have been compared with three theoretical isostatic compensation models, two local compensation models (Airy I and II) and one regional compensation (plate) model. Comparing the longer wavelength admittance estimates suggests that the regional compensation model gives the best fit for both the Alula-Fartak transform and the Owen transform, with effective elastic thickness (Te) of 5 km and slightly less than 10 km, respectively. For the Alula-Fartak transform, the Airy II model might also be acceptable, though with large scatter in the observed values: it suggests a mean value of 9 km for the mantle layer with a 6 km thick crust. For the Owen transform, on the other hand, the two local compensation models failed. The difference in Te estimate between the two transforms could be ascribed to differences in thermal structure arising from their varied tectonic history. A comparison with the isostatic response estimates of transform/fracture zones along the slow-spreading Mid-Atlantic Ridge suggests that the regional compensation model is generally applicable for transform/fracture zone topography along such mid-ocean ridges.

Lithospheric flexural strength and effective elastic thicknesses of the Eastern Anatolia (Turkey) and surrounding region

NASA Astrophysics Data System (ADS)

Oruç, Bülent; Gomez-Ortiz, David; Petit, Carole

2017-12-01

The Lithospheric structure of Eastern Anatolia and the surrounding region, including the northern part of the Arabian platform is investigated via the analysis and modeling of Bouguer anomalies from the Earth Gravitational Model EGM08. The effective elastic thickness of the lithosphere (EET) that corresponds to the mechanical cores of the crust and lithospheric mantle is determined from the spectral coherence between Bouguer anomalies and surface elevation data. Its average value is 18.7 km. From the logarithmic amplitude spectra of Bouguer anomalies, average depths of the lithosphere-asthenosphere boundary (LAB), Moho, Conrad and basement in the study area are constrained at 84 km, 39 km, 16 km and 7 km, respectively. The geometries of the LAB and Moho are then estimated using the Parker-Oldenburg inversion algorithm. We also present a lithospheric strength map obtained from the spatial variations of EET determined by Yield Stress Envelopes (YSE). The EET varies in the range of 12-23 km, which is in good agreement with the average value obtained from spectral analysis. Low EET values are interpreted as resulting from thermal and flexural lithospheric weakening. According to the lithospheric strength of the Eastern Anatolian region, the rheology model consists of a strong but brittle upper crust, a weak and ductile lower crust, and a weak lower part of the lithosphere. On the other hand, lithosphere strength corresponds to weak and ductile lower crust, a strong upper crust and a strong uppermost lithospheric mantle for the northern part of the Arabian platform.

Analysis of the velocity law in the wind of the Be star Lambda Pavonis

NASA Technical Reports Server (NTRS)

Chen, Haiqi; Ringuelet, Adela; Sahade, Jorge; Kondo, Yoji

1989-01-01

This paper reanalyzes the IUE spectra of Lambda Pavonis secured in 1982 (Sahade et al.). It is found that the profiles of the broad UV lines are either rotationally broadened or nonrotationally broadened and that the rotationally broadened profiles can be sorted out in two groups characterized by rotational velocity values of 170 km/s and of 210 km/s, respectively. From the analysis of the rotational and of the radial velocities it is possible to distinguish two regions in the extended atmosphere of the star, namely, a region which is rotating and a region which is expanding. In the rotating region, the radial velocities are about zero, and the rotational velocity increases from 170 km/s to 250 km/s. In the expanding region, the rotational energy dissipates, the wind is accelerated to a maximum of -155 km/s, and farther out it decelerates.

Drug oxygenation activities mediated by liver microsomal flavin-containing monooxygenases 1 and 3 in humans, monkeys, rats, and minipigs.

PubMed

Yamazaki, Miho; Shimizu, Makiko; Uno, Yasuhiro; Yamazaki, Hiroshi

2014-07-15

Liver microsomal flavin-containing monooxygenases (FMO, EC 1.14.13.8) 1 and 3 were functionally characterized in terms of expression levels and molecular catalytic capacities in human, cynomolgus monkey, rat, and minipig livers. Liver microsomal FMO3 in humans and monkeys and FMO1 and FMO3 in rats and minipigs could be determined immunochemically with commercially available anti-human FMO3 peptide antibodies or rat FMO1 peptide antibodies. With respect to FMO-dependent N-oxygenation of benzydamine and tozasertib and S-oxygenation of methimazole and sulindac sulfide activities, rat and minipig liver microsomes had high maximum velocity values (Vmax) and high catalytic efficiency (Vmax/Km, Michaelis constant) compared with those for human or monkey liver microsomes. Apparent Km values for recombinantly expressed rat FMO3-mediated N- and S-oxygenations were approximately 10-100-fold those of rat FMO1, although these enzymes had similar Vmax values. The mean catalytic efficiencies (Vmax/Km, 1.4 and 0.4 min(-1)μM(-1), respectively) of recombinant human and monkey FMO3 were higher than those of FMO1, whereas Vmax/Km values for rat and minipig FMO3 were low compared with those of FMO1. Minipig liver microsomal FMO1 efficiently catalyzed N- and S-oxygenation reactions; in addition, the minipig liver microsomal FMO1 concentration was higher than the levels in rats, humans, and monkeys. These results suggest that liver microsomal FMO1 could contribute to the relatively high FMO-mediated drug N- and S-oxygenation activities in rat and minipig liver microsomes and that lower expression of FMO1 in human and monkey livers could be a determinant factor for species differences in liver drug N- and S-oxygenation activities between experimental animals and humans. Copyright © 2014 Elsevier Inc. All rights reserved.

Experiments on a repetitively pulsed electrothermal thruster

NASA Technical Reports Server (NTRS)

Burton, R. L.; Fleischer, D.; Goldstein, S. A.; Tidman, D. A.

1987-01-01

This paper presents experimental results from an investigation of a pulsed electrothermal (PET) thruster using water propellant. The PET thruster is operated on a calibrated thrust stand, and produces a thrust to power ratio of T/P = 0.07 + or - 0.01 N/kW. The discharge conditions are inferred from a numerical model which predicts pressure and temperature levels of 300-500 atm and 20,000 K, respectively. These values in turn correctly predict the measured values of impulse bit and discharge resistance. The inferred ideal exhaust velocity from these conditions is 17 km/sec, but the injection of water propellant produces a test tank background pressure of 10-20 Torr, which reduces the exhaust velocity to 14 km/sec. This value corresponds to a thrust efficiency of 54 + or - 7 percent when all experimental errors are taken into account.

Photochemistry of Triton's atmosphere and ionosphere.

PubMed

Krasnopolsky, V A; Cruikshank, D P

1995-10-25

The photochemistry of 32 neutral and 21 ion species in Triton's atmosphere is considered. Parent species N2, CH4, and CO (with a mixing ratio of 3 x 10(-4) in our basic model) sublime from the ice with rates of 40, 208, and 0.3 g/cm2/b.y., respectively. Chemistry below 50 km is driven mostly by photolysis of methane by the solar and interstellar medium Lyman-alpha photons, producing hydrocarbons C2H4, C2H6, and C2H2 which form haze particles with precipitation rates of 135, 28, and 1.3 g/cm2/b.y., respectively. Some processes are discussed which increase the production of HCN (by an order of magnitude to a value of 29 g/cm2/b.y.) and involve indirect photolysis of N2 by neutrals. Reanalysis of the measured methane profiles gives an eddy diffusion coefficient K = 4 x 10(3) cm2/s above the tropopause and a more accurate methane number density near the surface, (3.1 +/- 0.8) x 10(11) cm-3. Chemistry above 200 km is driven by the solar EUV radiation (lambda < 1000 angstroms) and by precipitation of magnetospheric electrons with a total energy input of 10(8) W (based on thermal balance calculations). The most abundant photochemical species are N, H2, H, O, and C. They escape with the total rates of 7.7 x 10(24) s-1, 4.5 x 10(25) s-1, 2.4 x 10(25) s-1, 4.4 x 10(22) s-1, and 1.1 x 10(24) s-1, respectively. Atomic species are transported to a region of 50-200 km and drive the chemistry there. Ionospheric chemistry explains the formation of an E region at 150-240 km with HCO+ as a major ion, and of an F region above 240 km with a peak at 320 km and C+ as a major ion. The ionosphere above 500 km consists of almost equal densities of C+ and N+ ions. The model profiles agree with the measured atomic nitrogen and electron density profiles. A number of other models with varying rate coefficients of some reactions, differing properties of the haze particles (chemically passive or active), etc., were developed. These models show that there are four basic unknown values which have strong impacts on the composition and structure of the atmosphere and ionosphere. These values and their plausible ranges are the CO mixing ratio fco = 10(-4)-10(-3), the magnetospheric electron energy input (1 +/- 0.5) x 10(8) W, the rate coefficient of charge-exchange reaction N2(+) + C k = 10(-11)-10(-10) cm3/s, and the ion escape velocity Vi approximately equal to 150 cm/s.

Purification and Partial Characterization of a Fructanase which Hydrolyzes Natural Polysaccharides from Sugarcane Juice 1

PubMed Central

Legaz, M. Estrella; Martin, Luisa; Pedrosa, Mercedes M.; Vicente, Carlos; de Armas, Roberto; Martínez, Maritza; Medina, Isabel; Rodriguez, Carlos W.

1990-01-01

A new sugarcane (Saccharum officinarum L.) fructanase which hydrolyzes both high molecular weight polysaccharides ∣Fructose4:Galactitol5∣n (SP) and moderate-sized carbohydrates ∣Fructose2:Galactitol33∣n (MMWC) has been purified from sugarcane juice. The Km value has been estimated to be 33.7 micrograms per milliliter and 20 micrograms per milliliter for SP and MMWC, respectively. The optimal pH and temperature values are 6.0 and 30°C, respectively. Purified protein has a pl value of 6.35 and a molecular weight of 13.2 kilodaltons. Fructanase activity appears to be Mn2+-dependent. PMID:16667334

Comparison of the metabolism of parathion by a rat liver reconstituted mixed-function oxidase enzyme system and by a system containing cumene hydroperoxide and purified rat liver cytochrome P-450.

PubMed

Yoshihara, S; Neal, R A

1977-01-01

The metabolism of parathion by a reconstituted mixed-function oxidase enzyme system (rat liver cytochrome P-450, NADPH-cytochrome c reductase, dilauroyl phosphatidylcholine, deoxycholate, and NADPH) or a cumene hydroperoxide system (cytochrome P-450, dilauroyl phosphatidylcholine, and cumene hydroperoxide) have been compared. The products formed on incubation of parathion with both systems were paraoxon, diethyl phosphorothioic acid, diethyl phosphoric acid, p-nitrophenol, and atomic sulfur. The apparent KM values for parathion for formation of paraoxon and diethyl phosphorothioic acid with the cumene hydroperoxide system were 55 and 39 X 10(-6) M, respectively. These KM values are not significantly different. When the reconstituted system was used, apparent KM values of 2.8 x 10(-6) M for formation of paraoxon and 3.9 x 10(-6) M for The formation of diethyl phosphorothioic acid and diethyl phosphoric acid were determined. These KM values are also not significantly different. covalent binding of the sulfur atom, released in the metabolism of parathion to paraoxon, to the proteins of the reconstituted system and to cytochrome P-450 of the cumene hydroperoxide system was also examined. With both the reconstituted system and the cumene hydroperoxide system approximately 65% of the sulfur released became bound to the proteins of these enzyme systems. The binding of the sulfur atome resulted in a progressive inhibition of the metabolism of parathion by these two systems.

Effects of multi-frequency power ultrasound on the enzymolysis of corn gluten meal: Kinetics and thermodynamics study.

PubMed

Jin, Jian; Ma, Haile; Qu, Wenjuan; Wang, Kai; Zhou, Cunshan; He, Ronghai; Luo, Lin; Owusu, John

2015-11-01

The effects of multi-frequency power ultrasound (MPU) pretreatment on the kinetics and thermodynamics of corn gluten meal (CGM) were investigated in this research. The apparent constant (KM), apparent break-down rate constant (kA), reaction rate constants (k), energy of activation (Ea), enthalpy of activation (ΔH), entropy of activation (ΔS) and Gibbs free energy of activation (ΔG) were determined by means of the Michaelis-Menten equation, first-order kinetics model, Arrhenius equation and transition state theory, respectively. The results showed that MPU pretreatment can accelerate the enzymolysis of CGM under different enzymolysis conditions, viz. substrate concentration, enzyme concentration, pH, and temperature. Kinetics analysis revealed that MPU pretreatment decreased the KM value by 26.1% and increased the kA value by 7.3%, indicating ultrasound pretreatment increased the affinity between enzyme and substrate. In addition, the values of k for ultrasound pretreatment were increased by 84.8%, 41.9%, 28.9%, and 18.8% at the temperature of 293, 303, 313 and 323 K, respectively. For the thermodynamic parameters, ultrasound decreased Ea, ΔH and ΔS by 23.0%, 24.3% and 25.3%, respectively, but ultrasound had little change in ΔG value in the temperature range of 293-323 K. In conclusion, MPU pretreatment could remarkably enhance the enzymolysis of CGM, and this method can be applied to protein proteolysis industry to produce peptides. Copyright © 2015 Elsevier B.V. All rights reserved.

Functional characterisation of a tropine-forming reductase gene from Brugmansia arborea, a woody plant species producing tropane alkaloids.

PubMed

Qiang, Wei; Xia, Ke; Zhang, Qiaozhuo; Zeng, Junlan; Huang, Yuanshe; Yang, Chunxian; Chen, Min; Liu, Xiaoqiang; Lan, Xiaozhong; Liao, Zhihua

2016-07-01

Brugmansia arborea is a woody plant species that produces tropane alkaloids (TAs). The gene encoding tropine-forming reductase or tropinone reductase I (BaTRI) in this plant species was functionally characterised. The full-length cDNA of BaTRI encoded a 272-amino-acid polypeptide that was highly similar to tropinone reductase I from TAs-producing herbal plant species. The purified 29kDa recombinant BaTRI exhibited maximum reduction activity at pH 6.8-8.0 when tropinone was used as substrate; it also exhibited maximum oxidation activity at pH 9.6 when tropine was used as substrate. The Km, Vmax and Kcat values of BaTRI for tropinone were 2.65mM, 88.3nkatmg(-1) and 2.93S(-1), respectively, at pH 6.4; the Km, Vmax and Kcat values of TRI from Datura stramonium (DsTRI) for tropinone were respectively 4.18mM, 81.20nkatmg(-1) and 2.40S(-1) at pH 6.4. At pH 6.4, 6.8 and 7.0, BaTRI had a significantly higher activity than DsTRI. Analogues of tropinone, 4-methylcyclohexanone and 3-quinuclidinone hydrochloride, were also used to investigate the enzymatic kinetics of BaTRI. The Km, Vmax and Kcat values of BaTRI for tropine were 0.56mM, 171.62nkat.mg(-1) and 5.69S(-1), respectively, at pH 9.6; the Km, Vmax and Kcat values of DsTRI for tropine were 0.34mM, 111.90nkatmg(-1) and 3.30S(-1), respectively, at pH 9.6. The tissue profiles of BaTRI differed from those in TAs-producing herbal plant species. BaTRI was expressed in all examined organs but was most abundant in secondary roots. Finally, tropane alkaloids, including hyoscyamine, anisodamine and scopolamine, were detected in various organs of B. arborea by HPLC. Interestingly, scopolamine constituted most of the tropane alkaloids content in B. arborea, which suggests that B. arborea is a scopolamine-rich plant species. The scopolamine content was much higher in the leaves and stems than in other organs. The gene expression and TAs accumulation suggest that the biosynthesis of hyoscyamine, especially scopolamine, occurred not only in the roots but also in the aerial parts of B. arborea. Copyright © 2016 Elsevier Ltd. All rights reserved.

Foucault's method for measuring the speed of light with modern apparatus

NASA Astrophysics Data System (ADS)

Vörös, Zoltán; Weihs, Gregor

2015-05-01

In this paper, we introduce two simple and inexpensive, yet quite accurate versions of the well-known Foucault method for measuring the speed of light. In a compact footprint of just 20 cm by 270 cm with readily available laboratory items, a rotating mirror taken from a laser printer, and a webcam, we obtained c=296\\720+/- 3000 km s-1, and c=302\\295+/- 3000 km s-1, respectively, both within less than a per cent of the defined value. The experiment also prepares students for extracting data through image processing.

Bank Erosion Vulnerability Zonation (BEVZ) -A Proposed Method of Preparing Bank Erosion Zonation and Its Application on the River Haora, Tripura, India

NASA Astrophysics Data System (ADS)

Bandyopadhyay, Shreya; de, Sunil Kumar

2014-05-01

In the present paper an attempt has been made to propose RS-GIS based method for erosion vulnerability zonation for the entire river based on simple techniques that requires very less field investigation. This method consist of 8 parameters, such as, rainfall erosivity, lithological factor, bank slope, meander index, river gradient, soil erosivity, vegetation cover and anthropogenic impact. Meteorological data, GSI maps, LISS III (30m resolution), SRTM DEM (56m resolution) and Google Images have been used to determine rainfall erosivity, lithological factor, bank slope, meander index, river gradient, vegetation cover and anthropogenic impact; Soil map of the NBSSLP, India has been used for assessing Soil Erosivity index. By integrating the individual values of those six parameters (the 1st two parameters are remained constant for this particular study area) a bank erosion vulnerability zonation map of the River Haora, Tripura, India (23°37' - 23°53'N and 91°15'-91°37'E) has been prepared. The values have been compared with the existing BEHI-NBS method of 60 spots and also with field data of 30 cross sections (covering the 60 spots) taken along 51 km stretch of the river in Indian Territory and found that the estimated values are matching with the existing method as well as with field data. The whole stretch has been divided into 5 hazard zones, i.e. Very High, High, Moderate, Low and Very Low Hazard Zones and they are covering 5.66 km, 16.81 km, 40.82km, 29.67 km and 9.04 km respectively. KEY WORDS: Bank erosion, Bank Erosion Hazard Index (BEHI), Near Bank Stress (NBS), Erosivity, Bank Erosion Vulnerability Zonation.

Quadrature errors in the partical derivatives required for the direct recovery of gravity anomalies from satellite observations

NASA Technical Reports Server (NTRS)

Hajela, D. P.

1972-01-01

The equations of motion of a geodetic satellite in the earth's gravitational field expressed by gravity anomalies require the evaluation, amongst others, of the partial derivatives of the disturbing force with respect to individual gravity anomalies. Data are discussed on how anomaly blocks should be subdivided so that the partial derivatives may be numerically evaluated for each subdivision, and then finally meaned to give the value representative of the whole blocks, with accuracies better than 2 to 3 percent for all blocks. The number of subdivisions is large for the blocks nearest to the satellite subpoint and decreases away from it. The actual values of this spherical distance and the actual subdivision of the mean gravity anomaly blocks was determined numerically for 184 15 deg x 15 deg equal area blocks. Satellite heights above the earth of 400 km, 800 km and 1600 km were considered. The computer times for the suggested scheme were compared with alternative solutions.

The O(3P) and N(4S) density measurement at 225 km by ultraviolet absorption and fluorescence in the Apollo-Soyuz test project

NASA Technical Reports Server (NTRS)

Kaufman, F.; Rawling, W. T.; Donahue, T. M.; Anderson, J. G.; Hudson, R. D.

1976-01-01

The densities of O(3P) and N(4S) at 225 km were determined during the Apollo Soyuz Test Project by a resonance absorption/fluorescence technique in which OI and NI line radiation produced and collimated on board the Apollo was reflected from the Soyuz back to the Apollo for spectral analysis. The two spacecraft maneuvered so that a range of observation angles of plus or minus 15 deg with respect to the normal to the orbital velocity vector was scanned. The measurements were made at night on two consecutive orbits at spacecraft separations of 150 and 500 m. The resulting relative counting rates as function of observation angle were compared to calculated values to determine the oxygen value. This value agrees with mass spectrometric measurements made under similar conditions. The nitrogen value is in good agreement with other measurements and suggests a smaller diurnal variation than is predicted by present models.

A simple parameterization for the height of maximum ozone heating rate

NASA Astrophysics Data System (ADS)

Zhang, Feng; Hou, Can; Li, Jiangnan; Liu, Renqiang; Liu, Cuiping

2017-12-01

It is well-known that the height of the maximum ozone heating rate is much higher than the height of the maximum ozone concentration in the stratosphere. However, it lacks an analytical expression to explain it. A simple theoretical model has been proposed to calculate the height of maximum ozone heating rate and further understand this phenomenon. Strong absorption of ozone causes the incoming solar flux to be largely attenuated before reaching the location of the maximum ozone concentration. By comparing with the exact radiative transfer calculations, the heights of the maximum ozone heating rate produced by the theoretical model are generally very close to the true values. When the cosine of solar zenith angle μ0 = 1.0 , in US Standard atmosphere, the heights of the maximum ozone heating rate by the theoretical model are 41.4 km in the band 0.204-0.233 μm, 47.9 km in the band 0.233-0.270 μm, 44.5 km in the band 0.270-0.286 μm, 37.1 km in the band 0.286-0.303 μm, and 30.2 km in the band 0.303-0.323 μm, respectively. The location of the maximum ozone heating rate is sensitive to the solar spectral range. In band 1, the heights of the maximum ozone heating rate by the theoretical model are 52.3 km for μ0 = 0.1 , 47.1 km for μ0 = 0.3 , 44.6 km for μ0 = 0.5 , 43.1 km for μ0 = 0.7 , 41.9 km for μ0 = 0.9 , 41.4 km for μ0 = 1.0 in US Standard atmosphere, respectively. This model also illustrates that the location of the maximum ozone heating rate is sensitive to the solar zenith angle.

The upper atmosphere layer height changes as a precursor of the Padang earthquake on 30 September 2009

NASA Astrophysics Data System (ADS)

Ednofri, Ednofri; Wu, Falin; Ahmed, Wasiu Akande; Zhao, Yan

2017-09-01

This research investigated the potential of the upper atmosphere layer height changes as precursor of the Padang Earthquake on 30 September 2009. We analyzed the occurrence of atmospheric gravity wave (AGW) in all-sky imager (ASI) images and h'F in ionosonde mounted on Kototabang (0.2°S, 100.3°E, -10.4° magnetic latitude) Indonesia from seven days before and after the earthquake and found that there was an unusual evening in h'F variation on 24 and 29 September 2009. A positive h'F deviation on 24 and 29 September 2009 are with a maximum value of 42 and 31.5. For both these dates, the maximum h'F value reached 234 km and 261 km at 00:30 LT and 20:30 LT with the median value of 192 km and 229.5 km, respectively. The increase in h'F on 24 September 2009 before the midnight was caused by encouragement from AGW observed at a wavelength of OH bands ( 86 km) that happened a few minutes earlier. While the increase in h'F on 29 September 2009, suspected to be caused by the emergence of the AGW, though it cannot be proven because ASI does not operate due to rainy weather over Kototabang. For Dst index during the month of September 2009, there is nothing worth under -50 nT, this means a change of altitude h'F six and one days before the earthquake is not caused by the influence of magnetic storm but caused by AGW resulting from the epicenter.

Characteristics of Atmospheric Pollution in Handan, China

NASA Astrophysics Data System (ADS)

Zhang, P.; Wang, L.; Zhao, X.; Yang, J.; Wei, Z.; Su, J.; Zhang, F.; Meng, C.

2013-12-01

Handan, located in the southern edge of Hebei province, is one of the cities with worst air pollution in China. Based on the data from our comprehensive air quality monitoring station in Handan from August 2012 to January 2013, a series studies on the characteristics of air pollution in Handan were conducted. The daily mean concentration of PM10 and PM2.5 was 231.5 μg/m3 and 125.8 μg/m3 which exceeded daily National Ambient Air Quality Standard II (NAAQS) of China by 54.3% and 67.7% respectively. The highest daily concentration of them was 863.9 μg/m3 and 643.0 μg/m3, appeared on January 11, 2013, exceeding NAAQS by 475.9% and 757.3% respectively. Mean ratio of PM2.5/PM10 was 0.53. High PM2.5/PM10 ratio frequently occurred in winter, especially January (0.63) and February (0.65). Average daily concentration of SO2, NOx, NO2 and CO was 118 μg/m3, 133 μg/m3, 60.4 μg/m3 and 3210 μg/m3 respectively. The maximum daily average concentration of them was 393 μg/m3, 352 μg/m3, 135 μg/m3, 9660 μg/m3 which was 2.62, 3.52, 2.69, 2.42 times of daily NAAQS. The average concentration of total water soluble ions (TWSI) in PM2.5 from October 13 to December 21, 2012 was 69.57 μg/m3 which accounted for 61.67% of PM2.5. NO3-, SO42-, Cl- and NH4+ were the most important components of water soluble ionic composition in PM2.5.their concentration was 21.20 μg/m3, 16.96 μg/m3,8.43 μg/m3 and 14.81 μg/m3, accounted for 18.8%, 15.03% ,7.47% and 13.13% in PM2.5, respectively. Concentration of NO3- and SO42- had a good correlation (R2 = 0.807). The daily average concentration of OC and EC was 22.17 μg/m3, 6.29 μg/m3, accounted for 19.65%, 5.58% in PM2.5 respectively. The average ratio of OC/EC was 3.44, which shows that there is secondary organic carbon (SOC) in carbonaceous aerosol. Chemical characteristics of PM2.5 in Beijing, Tianjin and Handan were very similar. Most of Daily visibility values (67.4%) were lower than 5 km from August 2012 to January 2013. Daily visibility above 16 km was very scarce in Handan. Mean value of daily visibility was only 4.4×3.5 km in the range of 0.3 to 15.6 km. Average daily value of BC, NO, O3, RH, temperature, pressure was 9.3 μg/m3, 35.7 ppb, 20.6 ppb, 64.4%, 12.1 degree and 1011.2 hPa respectively. During the most polluted period from January 6 to January 31, 2013, mean daily visibility was 0.9 km. Average value of BC, NO, RH, temperature and pressure was 20.4 μg/m3, 98.4 ppb, 89.2%, -1.9 degree and 1015.9 hPa respectively. Visibility showed negative correlation with BC, RH, NO2, PM2.5, NOx, PM10, NO, CO, SO2, pressure and showed positive correlation with O3 and temperature. The most related four parameters with visibility were BC, RH, NO2 and PM2.5. The least related four parameters with visibility were O3, temperature, SO2 and pressure. Empirical model was developed to investigate the complex relationships between visibility, meteorological and pollutant parameters. The modeling result was as following: The model computed visibility had good consistence with the observed values.

Cone structure and focusing of VLF and LF electromagnetic waves at high altitudes in the ionosphere

NASA Technical Reports Server (NTRS)

Alpert, Ya. L.; Green, J. L.

1994-01-01

The frequency and angle dependencies of the electric field radiated by an electric dipole E = E(sub 0) cos omega(t) are studied through numerical calculations of absolute value of E in the VLF and LF frequency bands where F is less than or equal 0.02 to 0.05 f(sub b) in a model ionosphere over an altitude region of 800-6000 km where the wave frequency and electron gyrofrequency varies between F approximately 4-500 kHz and f(sub b) is approximately equal (1.1 to 0.2) MHz respectively. It is found that the amplitudes of the electric field have large maxima in four regions: close to the direction of the Earth magnetic field line B(sub 0) (it is called the axis field E(sub 0), in the Storey E(sub St), reversed Storey E(sub RevSt), and resonance E(sub Res) cones. The maximal values of E(sub 0), E(sub Res), and E(sub RevSt) are the most pronounced close to the lower hybrid frequency, F approximately F(sub L). The flux of the electric field is concentrated in very narrow regions, with the apex angles of the cones Delta-B is approximately (0.1-1) deg. The enhancement and focusing of the electric field increases with altitude starting at Z greater than 800 km. At Z greater than or equal to 1000 up to 6000 km, the relative value of absolute value of E, in comparison with its value at Z = 800 km is about (10(exp 2) to 10(exp 4)) times larger. Thus the flux of VLF and LF electromagnetic waves generated at high altitudes in the Earth's ionosphere are trapped into very narrow conical beams similar to laser beams.

Stable Isotopes of Tilted Ignimbrite Calderas in Nevada

NASA Astrophysics Data System (ADS)

John, D. A.; Watts, K. E.; Hofstra, A. H.; Colgan, J. P.; Henry, C.; Bindeman, I. N.

2013-12-01

Mid-Tertiary calderas are exceptionally well exposed in tilted fault blocks of the northern Great Basin, facilitating detailed evolutionary models of their magmatic-hydrothermal systems. The 29.4 Ma Job Canyon caldera, the oldest of 3 overlapping calderas in the Stillwater Range, west-central Nevada, is tilted ~90° exposing a 10-km-thick section of the crust. Large parts of the >7 km-diameter caldera system, including >2 km thickness of intracaldera rhyolitic tuff, lower parts of an ~2 km thick sequence of post-caldera intermediate lavas, and the upper 500 m of the resurgent granodioritic IXL pluton, were pervasively altered to propylitic, argillic, and sericitic assemblages. Sparse quartz×calcite veins cut the tuff. δ18O values of altered whole rock samples range from +4.8 to -9.1‰ but are mostly -6 to -9‰ at paleodepths >2 km. Calculated magmatic δ18O and δD values range from +6.4 to 8.2‰ and ~-70‰, respectively. Calculated fluid compositions using temperatures from fluid inclusions and mineral assemblages are δ18OH2O=-9.5 to -15‰ and δDH2O=-125 to -135‰ (chlorite) and -70 to -80‰ (epidote). Chlorite-whole rock data suggest fluids that were derived from moderately 18O-exchanged meteoric water. Fault blocks in north-central Nevada expose a >5 km upper crustal cross section through the 12-17 x 20 km, 34 Ma Caetano caldera, including >3 km thickness intracaldera rhyolitic Caetano Tuff. Asymmetric caldera subsidence left a depression >1 km deep partly filled with a lake. Magma resurgence and emplacement of shallow granite porphyry plutons drove a hydrothermal system that altered >120 km2 of the caldera to depths >1.5 km. Alteration was focused in an early granite porphyry intrusion and surrounding upper Caetano Tuff and lacustrine sediments. Early pervasive quartz-kaolinite-pyrite alteration grades outward and downward into more restricted quartz-illite/smectite-pyrite alteration. Hematite, quartz, and barite veins and hydrothermal breccias cut early alteration. Whole rock δ18O values of kaolinite-altered tuff and intrusions are +1.7 to +4.7‰. Magmatic δ18O values of Caetano rocks calculated from zircon and major phenocrysts range narrowly from +10.0 to +10.5‰. Calculated fluid compositions from kaolinite are δ18OH2O=-3 to -7‰ and δDH2O=-148 to -160‰, and from quartz and barite veins are δ18OH2O=-4 to -11‰, indicating that hydrothermal fluids also were dominantly 18O-exchanged meteoric water. Compared to the Job Canyon caldera, δDH2O values for Caetano hydrothermal fluids are ~25‰ lower, suggesting that Caetano formed at an elevation about 1 km higher than Job Canyon along the crest of the Nevadaplano. Both calderas hosted vigorous hydrothermal systems driven by heat from magma resurgence that pervasively altered and exchanged 18O and D with 10s to 100s km3 of rock. However, significant assimilation of low-18O hydrothermally altered rocks is not apparent by the exclusively normal-δ18O values of Job Canyon, Caetano, and adjacent younger magmas. Neither caldera is strongly mineralized, probably in part due to low sulfur contents of the hydrothermal fluids. More acidic fluids at Caetano suggest a larger magmatic gas (HCl) input likely resulting from degassing of shallow resurgent magma into the caldera lake.

Diesel bus emissions measured in a tunnel study.

PubMed

Jamriska, Milan; Morawska, Lidia; Thomas, Steven; He, Congrong

2004-12-15

The emission factors of a bus fleet consisting of approximately 300 diesel-powered buses were measured in a tunnel study under well-controlled conditions during a 2-d monitoring campaign in Brisbane. Particle number and mass concentration levels of submicrometer particles and PM2.5 were monitored by SMPS and DustTrak instruments at the tunnel's entrance and exit, respectively. Correlation between DustTrak and TEOM response to diesel emissions was assessed, and the DustTrak results were recalculated into TEOM equivalent data. The mean value of the number and mass emission factors was (3.11+/-2.41) x 10(14) particles km(-1) for submicrometer particles and 583+/-451 mg km(-1) for PM2.5 (DustTrak), respectively. TEOM PM2.5 equivalent emission factor was 267+/-207 mg km(-1). The results are in good agreement with the emission factors determined from steady-state dynamometer testing of 12 buses from the same Brisbane City bus fleet. The results indicate that when carefully designed, both approaches, the dynamometer and on-road studies, can provide comparable results, applicable for the assessment of the effect of traffic emissions on airborne particle pollution. A brief overview of emission factors determined from other on-road and dynamometer studies reported in the literature as well as with the regulatory values used for the vehicle emission inventory assessment is presented and compared with the results obtained in this study.

A quantitative analysis of global intermediate and deep seismicity

NASA Astrophysics Data System (ADS)

Ruscic, Marija; Becker, Dirk; Le Pourhiet, Laetitita; Agard, Philippe; Meier, Thomas

2017-04-01

The seismic activity in subduction zones around the world shows a large spatial variabilty with some regions exhibiting strong seismic activity down to depths of almost 700km while in other places seismicity terminates at depths of about 200 or 300 km. Also the decay of the number of seismic events or of the seismic moment with depth is more pronounced in some regions than in others. The same is true for the variability of the ratio of large to small events (the b-value of the Gutenberg-Richter relation) that is varying with depth. These observations are often linked to parameters of the downgoing plate like age or subduction velocity. In this study we investigate a subset of subduction zones utilizing the revised ISC catalogue of intermediate and deep seismicity to determine statistical parameters well suited to describe properties of intermediate deep and deep events. The seismicity is separated into three depth intervals from 50-175km, 175-400km and >400km based on the depth at which the plate contact decouples, the observed nearly exponential decay of the event rate with depth and the supposed depth of phase transition at 410 km depth where also an increase of the event number with depth is observed. For estimation of the b-value and the exponential decay with depth, a restriction of the investigated time interval to the period after 1997 produced significantly better results indicating a globally homogeneous magnitude scale with the magnitude of completeness of about Mw 5. On a global scale the b-value decreases with depth from values of about 1 at 50-175km to values of slightly below 0.8 for events below 400km. Also, there is a slight increase of the b-value with the age of the subducting plate. These changes in the b-value with depth and with age may indicate a varying fragmentation of the slab. With respect to the ratio of the seismic moment between deeper and shallower parts of the subduction zones a dependence on the age is apparent with older slabs exhibiting higher ratios indicating stronger hydration of older slabs and consequently stronger seismic activity at depth in older and thicker slabs. Furthermore, older slabs show the tendency to larger b-values. This indicates stronger fragmentation of older slabs favoring smaller events. Between 50 km and 300 km depth, seismicity in subduction zones decays nearly exponentially with depth. However, the majority of subduction zones show between about 60 km and 100 km lower seismic activity than expected by an exponential decay. This observation correlates well with findings from petrological studies that rocks are rarely scraped off from the downgoing plate at these depths indicating low seismic coupling and low stresses at the plate interface in a depth range below the seismogenic zone and above 100 km depth were dehydration reactions become virulent. Interestingly, the percentage of this deficit becomes larger with plate age for event frequency (reduced number of events), but decreases for moment release (events have larger magnitudes). It is observed that the forearc high is located above the plate interface with reduced seismic coupling. The forearc high is thus an indication of upward directed return flow along the seismically decoupled plate interface. In addition, it is found that the topography of the forearc high is larger above shallow dipping slabs. A correlation of the depth dependent seismic behavior with the subduction or trench velocity is not observed for the investigated subduction zones. Plate age seems to be the dominating factor for properties of intermediate deep and deep seismicity.

Photochemistry of Triton's Atmosphere and Ionosphere

NASA Technical Reports Server (NTRS)

Krasnopolsky, Vladimir A.; Cruikshank, Dale P.

1995-01-01

The photochemistry of 32 neutral and 21 ion species in Triton's atmosphere is considered. Parent species N2, CH4, and CO (with a mixing ratio of 3 x 10(exp -4) in our basic model) sublime from the ice with rates of 40, 208, and 0.3 g/sq cm/b.y., respectively. Chemistry below 50 km is driven mostly by photolysis of methane by the solar and interstellar medium Lyman-alpha photons, producing hydrocarbons C2H4, C2H6, and C2H2 which form haze particles with precipitation rates of 135, 28, and 1.3 g/sq cm/b.y., respectively. Some processes are discussed which increase the production of HCN (by an order of magnitude to a value of 29 g/sq cm/b.y.) and involve indirect photolysis of N2 by neutrals. Reanalysis of the measured methane profiles gives an eddy diffusion coefficient K = 4 x 10(exp 3)sq cm/s above the tropopause and a more accurate methane number density near the surface, (3.1 +/- 0.8)x IO(exp 11)/cu cm. Chemistry above 200 km is driven by the solar EUV radiation (lambda less than 1000 A) and by precipitation of magnetospheric electrons with a total energy input of 10(exp 8) W (based on thermal balance calculations). The most abundant photochemical species are N, H2, H, 0, and C. They escape with the total rates of 7.7 x 10(exp 24)/ s, 4.5 x 10(exp 25)/s, 2.4 x 10(exp 25)/s, 4.4 x 10(exp 22)/s, and 1.1 x 10(exp 24), respectively. Atomic species are transported to a region of 50-200 km and drive the chemistry there. Ionospheric chemistry explains the formation of an E region at 150-240 km with HCO(+) as a major ion, and of an F region above 240 km with a peak at 320 km and C(+) as a major ion. The ionosphere above 500 km consists of almost equal densities of C(+) and N(+) ions. The model profiles agree with the measured atomic nitrogen and electron density profiles. A number of other models with varying rate coefficients of some reactions, differing properties of the haze particles (chemically passive or active), etc., were developed. These models show that there are four basic unknown values which have strong impacts on the composition and structure of the atmosphere and ionosphere. These values and their plausible ranges are the CO mixing ratio f(sub co) = 10(exp -4) - 10(exp -3), the magnetospheric electron energy input (1 +/- 0.5) x 10(exp 8) W, the rate coefficient of charge-exchange reaction N2(+) + C(kappa) = 10(exp -11) - 10(exp -10)cu cm/s, and the ion escape velocity upsilon(sub i) approx. equals 150 cm/s.

Quantum theory of atoms in molecules/charge-charge flux-dipole flux models for fundamental vibrational intensity changes on H-bond formation of water and hydrogen fluoride

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silva, Arnaldo F.; Richter, Wagner E.; Bruns, Roy E., E-mail: bruns@iqm.unicamp.br

The Quantum Theory of Atoms In Molecules/Charge-Charge Flux-Dipole Flux (QTAIM/CCFDF) model has been used to investigate the electronic structure variations associated with intensity changes on dimerization for the vibrations of the water and hydrogen fluoride dimers as well as in the water-hydrogen fluoride complex. QCISD/cc-pVTZ wave functions applied in the QTAIM/CCFDF model accurately provide the fundamental band intensities of water and its dimer predicting symmetric and antisymmetric stretching intensity increases for the donor unit of 159 and 47 km mol{sup −1} on H-bond formation compared with the experimental values of 141 and 53 km mol{sup −1}. The symmetric stretching ofmore » the proton donor water in the dimer has intensity contributions parallel and perpendicular to its C{sub 2v} axis. The largest calculated increase of 107 km mol{sup −1} is perpendicular to this axis and owes to equilibrium atomic charge displacements on vibration. Charge flux decreases occurring parallel and perpendicular to this axis result in 42 and 40 km mol{sup −1} total intensity increases for the symmetric and antisymmetric stretches, respectively. These decreases in charge flux result in intensity enhancements because of the interaction contributions to the intensities between charge flux and the other quantities. Even though dipole flux contributions are much smaller than the charge and charge flux ones in both monomer and dimer water they are important for calculating the total intensity values for their stretching vibrations since the charge-charge flux interaction term cancels the charge and charge flux contributions. The QTAIM/CCFDF hydrogen-bonded stretching intensity strengthening of 321 km mol{sup −1} on HF dimerization and 592 km mol{sup −1} on HF:H{sub 2}O complexation can essentially be explained by charge, charge flux and their interaction cross term. Atomic contributions to the intensities are also calculated. The bridge hydrogen atomic contributions alone explain 145, 237, and 574 km mol{sup −1} of the H-bond stretching intensity enhancements for the water and HF dimers and their heterodimer compared with total increments of 149, 321, and 592 km mol{sup −1}, respectively.« less

Low-loss Kagome hollow-core fibers operating from the near- to the mid-IR.

PubMed

Wheeler, N V; Bradley, T D; Hayes, J R; Gouveia, M A; Liang, S; Chen, Y; Sandoghchi, S R; Abokhamis Mousavi, S M; Poletti, F; Petrovich, M N; Richardson, D J

2017-07-01

We report the fabrication and characterization of Kagome hollow-core antiresonant fibers, which combine low attenuation (as measured at ∼30  cm bend diameter) with a wide operating bandwidth and high modal purity. Record low attenuation values are reported: 12.3 dB/km, 13.9 dB/km, and 9.6 dB/km in three different fibers optimized for operation at 1 μm, 1.55 μm, and 2.5 μm, respectively. These fibers are excellent candidates for ultra-high power delivery at key laser wavelengths including 1.064 μm and 2.94 μm, as well as for applications in gas-based sensing and nonlinear optics.

Ozone isotope measurements in the stratosphere

NASA Technical Reports Server (NTRS)

Mauersberger, K.

1987-01-01

Mass spectrometer measurements of ozone made during two balloon flights included its heavy isotopes at mass 49 and 50. Both flights were flown during the day and during summer from Palestine, TX. At float altitudes above 42 km the enrichments in heavy ozone were 41 percent and 23 percent, respectively. The enrichment appears to be mass independent since, at high altitudes, both 49 and 50 show the same enhancement. During the descent the enrichment in heavy ozone decreased, faster during the first flight than during the second, reaching values between 15 and 20 percent above 30 km. Near and below this altitude another increase is observed. During a night flight, previously reported, an enhancement in heavy ozone of over 40 percent at 32 km was found, decreasing both toward higher and lower altitudes.

The Eighty Six Hα Spectra from the Orion Nebula (M42, Sh2-281) with DEFPOS

NASA Astrophysics Data System (ADS)

Sahan, M.; Yegingil, I.

2017-12-01

In this study, eighty six Hα (6563 Å) emission line spectra from the central region (˜ 40^' }× 40^' }) of the Orion Nebula (NGC1976, M42, Sh2-281) have been obtained using DEFPOS spectrometer with a circular field of view of 4^' } at TUBITAK National Observatory (TUG, Antalya, Turkey). Measurements provide information about the intensities, line widths, and radial velocities of the gas surrounding the Sh2-281 HII-region. The intensities, the radial velocities and the line widths of the Hα emission line were found in the range of from 319.85 R to 6009.08 R (mean 2006 ± 400 R), from -14.91 km s^{-1} to + 5.40 km s^{-1} (mean -4.51± 3.80 km s^{-1}), and from 27.83 km s^{-1} to 49.60 km s^{-1} (mean 41.09± 7.74 km s^{-1}), respectively. Moreover, the mean emission measure (EM) calculated from {I_{H{α }}} values was obtained as 4513.02 cm^{-6} pc. The mean LSR velocity of the nebula was found to be -4.51 km s^{-1} and was compared with some previous works. The intensity values of DEFPOS data were also compared with the data obtained from VTSS, SkyView, and SHASSA maps using APER and SKY codes. We found that our results were approximately the similar variation with VTSS (mean 2002.04 R), SkyView (mean 2680.05 R), and SHASSA (mean 2400.06 R) maps. We believe that DEFPOS spectrometer with a 4' diameter field of view is able to provide a powerful tool for the study of diffuse ionized gas and this new results may have significant contribution to the literature.

Spatial variations in effective elastic thickness in the Western Pacific Ocean and their implications for Mesozoic volcanism

NASA Astrophysics Data System (ADS)

Kalnins, L. M.; Watts, A. B.

2009-08-01

We have used free-air gravity anomaly and bathymetric data, together with a moving window admittance technique, to determine the spatial variation in oceanic elastic thickness, Te, in the Western Pacific ocean. Synthetic tests using representative seamounts show that Te can be recovered to an accuracy of ± 5 km for plates up to 30 km thick, with increased accuracy of ± 3 km for Te ≤ 20 km. The Western Pacific has a T e range of 0-50 km, with a mean of 9.4 km and a standard deviation of 6.8 km. The T e structure of the region is dominated by relatively high Te over the Hawaiian-Emperor Seamount Chain, intermediate values over the Marshall Islands, Gilbert Ridge, and Marcus-Wake Guyots, and low values over the Line Islands, Mid-Pacific Mountains, Caroline Islands, Shatsky Rise, Hess Rise, and Musician Seamounts. Plots of Te at sites with radiometric ages suggest that Te is to first order controlled by the age of the lithosphere at the time of loading. In areas that backtrack into the South Pacific Isotopic and Thermal Anomaly (SOPITA), Te may be as low as the depth to the 180 ± 120 °C isotherm at least locally. In the northern part of the study area including the Hawaiian-Emperor Seamount Chain, Te correlates with the depth to 310 ± 120 °C. These best-fitting isotherms imply peak rates of volcanism during 100-120 Ma (Early Cretaceous) and 140-150 Ma (Late Jurassic). The corresponding addition of 8 × 10 6 km 3 and 4 × 10 6 km 3 of volcanic material to the surface of the oceanic crust would result in long-term sea-level rises of 20 m and 10 m respectively. The Late Jurassic volcanic event, like the later Early Cretaceous event, appears to have influenced the tectonic evolution of the Pacific plate convergent boundaries, resulting in increased volcanism and orogenesis.

Coordinated Hubble Space Telescope and Venus Express Observations of Venus' upper cloud deck

NASA Astrophysics Data System (ADS)

Jessup, Kandis Lea; Marcq, Emmanuel; Mills, Franklin; Mahieux, Arnaud; Limaye, Sanjay; Wilson, Colin; Allen, Mark; Bertaux, Jean-Loup; Markiewicz, Wojciech; Roman, Tony; Vandaele, Ann-Carine; Wilquet, Valerie; Yung, Yuk

2015-09-01

Hubble Space Telescope Imaging Spectrograph (HST/STIS) UV observations of Venus' upper cloud tops were obtained between 20N and 40S latitude on December 28, 2010; January 22, 2011 and January 27, 2011 in coordination with the Venus Express (VEx) mission. The high spectral (0.27 nm) and spatial (40-60 km/pixel) resolution HST/STIS data provide the first direct and simultaneous record of the latitude and local time distribution of Venus' 70-80 km SO and SO2 (SOx) gas density on Venus' morning quadrant. These data were obtained simultaneously with (a) VEx/SOIR occultation and/or ground-based James Clerk Maxwell Telescope sub-mm observations that record respectively, Venus' near-terminator SO2 and dayside SOx vertical profiles between ∼75 and 100 km; and (b) 0.36 μm VEx/VMC images of Venus' cloud-tops. Updating the (Marcq, E. et al. [2011]. Icarus 211, 58-69) radiative transfer model SO2 gas column densities of ∼2-10 μm-atm and ∼0.4-1.8 μm-atm are retrieved from the December 2010 and January 2011 HST observations, respectively on Venus' dayside (i.e., at solar zenith angles (SZA) < 60°); SO gas column densities of 0.1-0.11 μm-atm, 0.03-0.31 μm-atm and 0.01-0.13 μm-atm are also retrieved from the respective December 28, 2010, January 22, 2011 and January 27, 2011 HST observations. A decline in the observed low-latitude 0.24 and 0.36 μm cloud top brightness paralleled the declining SOx gas densities. On December 28, 2010 SO2 VMR values ∼280-290 ppb are retrieved between 74 and 81 km from the HST and SOIR data obtained near Venus' morning terminator (at SZAs equal to 70° and 90°, respectively); these values are 10× higher than the HST-retrieved January 2011 near terminator values. Thus, the cloud top SO2 gas abundance declined at all local times between the three HST observing dates. On all dates the average dayside SO2/SO ratio inferred from HST between 70 and 80 km is higher than that inferred from the sub-mm the JCMT data above 84 km confirming that SOx photolysis is more efficient at higher altitudes. The direct correlation of the SOx gases provides the first clear evidence that SOx photolysis is not the only source for Venus' 70-80 km sulfur reservoir. The cloud top SO2 gas density is dependent in part on the vertical transport of the gas from the lower atmosphere; and the 0.24 μm cloud top brightness levels are linked to the density of the sub-micron haze. Thus, the new results may suggest a correlation between Venus' cloud-top sub-micron haze density and the vertical transport rate. These new results must be considered in models designed to simulate and explore the relationship between Venus' sulfur chemistry cycle, H2SO4 cloud formation rate and climate evolution. Additionally, we present the first photochemical model that uniquely tracks the transition of the SO2 atmosphere from steady to non-steady state with increasing SZA, as function of altitude within Venus' mesosphere, showing the photochemical and dynamical basis for the factor of ∼2 enhancements in the SOx gas densities observed by HST near the terminator above that observed at smaller SZA. These results must also be considered when modeling the long-term evolution of Venus' atmospheric chemistry and dynamics.

Geomagnetism during solar cycle 23: Characteristics.

PubMed

Zerbo, Jean-Louis; Amory-Mazaudier, Christine; Ouattara, Frédéric

2013-05-01

On the basis of more than 48 years of morphological analysis of yearly and monthly values of the sunspot number, the aa index, the solar wind speed and interplanetary magnetic field, we point out the particularities of geomagnetic activity during the period 1996-2009. We especially investigate the last cycle 23 and the long minimum which followed it. During this period, the lowest values of the yearly averaged IMF (3 nT) and yearly averaged solar wind speed (364 km/s) are recorded in 1996, and 2009 respectively. The year 2003 shows itself particular by recording the highest value of the averaged solar wind (568 km/s), associated to the highest value of the yearly averaged aa index (37 nT). We also find that observations during the year 2003 seem to be related to several coronal holes which are known to generate high-speed wind stream. From the long time (more than one century) study of solar variability, the present period is similar to the beginning of twentieth century. We especially present the morphological features of solar cycle 23 which is followed by a deep solar minimum.

Metabolism of ethylbenzene by human liver microsomes and recombinant human cytochrome P450s (CYP).

PubMed

Sams, Craig; Loizou, George D; Cocker, John; Lennard, Martin S

2004-03-07

The enzyme kinetics of the initial hydroxylation of ethylbenzene to form 1-phenylethanol were determined in human liver microsomes. The individual cytochrome P450 (CYP) forms catalysing this reaction were identified using selective inhibitors and recombinant preparations of hepatic CYPs. Production of 1-phenylethanol in hepatic microsomes exhibited biphasic kinetics with a high affinity, low Km, component (mean Km = 8 microM; V(max) = 689 pmol/min/mg protein; n = 6 livers) and a low affinity, high Km, component (Km = 391 microM; V(max) = 3039 pmol/min/mg protein; n = 6). The high-affinity component was inhibited 79%-95% (mean 86%) by diethyldithiocarbamate, and recombinant CYP2E1 was shown to metabolise ethylbenzene with low Km (35 microM), but also low (max) (7 pmol/min/pmol P450), indicating that this isoform catalysed the high-affinity component. Recombinant CYP1A2 and CYP2B6 exhibited high V(max) (88 and 71 pmol/min/pmol P450, respectively) and high Km (502 and 219 microM, respectively), suggesting their involvement in catalysing the low-affinity component. This study has demonstrated that CYP2E1 is the major enzyme responsible for high-affinity side chain hydroxylation of ethylbenzene in human liver microsomes. Activity of this enzyme in the population is highly variable due to induction or inhibition by physiological factors, chemicals in the diet or some pharmaceuticals. This variability can be incorporated into the risk assessment process to improve the setting of occupational exposure limits and guidance values for biological monitoring.

Regional difference in small-scale heterogeneities in the crust and upper mantle in Japan derived by the analysis of high-frequency P-wave

NASA Astrophysics Data System (ADS)

Takemura, S.; Furumura, T.

2010-12-01

In order to understand distribution properties of small-scale heterogeneities in the crust and upper mantle structure, we analyze three-component seismograms recorded by Hi-net in Japan. We examined relative strength of the P-wave in the transverse (T) component and its change as a function of frequency and propagation distances, which is strongly relating to the strength of seismic wave scattering in the lithosphere. We analyzed 53,220 Hi-net record from 310 shallow (h<30km) crustal earthquakes with MJMA =2.0-5.3. The three-component seismograms are firstly applied by band-pass filter with pass band frequency of f=1-2, 2-4, 4-8, 8-16, 16-32 Hz and then the Hilbert transform is used to synthesize envelope of each component. Then, the energy partition (EP) of P wave in the T component relative to total P-wave energy is evaluated around the P wave in 3-sec time window. The estimated EP value is almost constant 0.2 in high-frequencies (8-16 Hz) at shorter distance, while it is 0.07 in low-frequencies (1-2 Hz). We found clearly frequency-change property of EP value. But at larger distance over 150 km, EP values gradually increase with increasing distance. In high-frequencies (8-16, 16-32 Hz), especially EP values asymptotically reach from 0.2 to 0.33, equi-partitioning of P-wave energy into three components. This may because Pn-phase dominates in larger hypocentral distances. In order to examine difference in the EP in each area of Japan which would be relating to the strength of crustal heterogeneities in each area we divided the area of Japan into three regions, fore-arc side of Tohoku, back-arc side of Tohoku and Chugoku-Shikoku area. The difference in EP value in each area is clearly found in the high-frequency (4-8 Hz) band, where larger EP (0.2) was obtained at back-arc side of Tohoku relative to smaller EP (0.1) at fore-arc side of Tohoku and Chugoku-Shikoku. This is consistent with the results of Carcole and Sato (2009) who estimated the strength of crustal heterogeneities based on the multi lapse time-window analysis. In order to clarify the cause of such regional difference of EP, we conduct 3-D FDM simulations using stochastic random media. The model covers a zone 204.8 km by 204.8 km by 64.0 km descretized with 0.1 km in horizontal direction and 0.05 km in vertical direction. The small-scale heterogeneity in the lithosphere is constructed by velocity fluctuation from average velocity. The fluctuation is characterized by von Karman-type ACF with the correlation length a, the rms value e and decay order k. We assume average background velocities of P-wave and S-wave are VP = 5.8 km and VS = 3.36 km, respectively. We employ an explosive point source into the model. The FDM simulations were conducted on the Earth Simulator at JAMSTEC. We conducted a number of FDM simulation using different model parameters of stochastic random media for different e (= 0.03, 0.05, 0.07, 0.09) and fixed a and k (a = 5km, k = 0.5). The simulation results confirm EP value increases linearly with increasing e. We also found that larger EP obtained in the back-arc side of Tohoku can be explained by 4% larger e relative to those of other regions.

2H Kinetic Isotope Effects and pH Dependence of Catalysis as Mechanistic Probes of Rat Monoamine Oxidase A: Comparisons with the Human Enzyme‡

PubMed Central

Wang, Jin; Edmondson, Dale E.

2011-01-01

Monoamine oxidase A (MAO A) is a mitochondrial outer membrane-bound flavoenzyme important in the regulation of serotonin and dopamine levels. Since the rat is extensively used as an animal model in drug studies, it is important to understand how rat MAO A behaves in comparison with the more extensively studied human enzyme. For many reversible inhibitors, rat MAO A exhibits Ki values similar to those of human MAO A. The pH profile of kcat for rat MAO A shows a pKa of 8.2±0.1 for the benzylamine ES complex and pKa values of 7.5±0.1 and 7.6±0.1 for the respective ES complexes with p-CF3-1H and p-CF3-2H-benzylamine. In contrast to the human enzyme, the rat enzyme exhibits a single pKa value (8.3±0.1) with kcat/Km benzylamine vs. pH and pKa values of 7.8±0.1 and 8.1±0.2 are found for the ascending limbs, respectively, of kcat/Km vs. pH profiles for p-CF3-1H and p-CF3-2H-benzylamine and 9.3±0.1 and 9.1±0.2 for their respective descending limbs. The oxidation of para-substituted benzylamine substrate analogues by rat MAO A exhibit large deuterium kinetic isotope effects on kcat and on kcat/Km. These effects are pH-independent, and range from 7 to 14, demonstrating a rate-limiting α-C-H bond cleavage step in catalysis. Quantitative structure-activity correlations of log kcat with the electronic substituent parameter (σ) at pH 7.5 and at 9.0 show a dominant contribution with positive ρ values (+1.2 – 1.3) and a pH-independent negative contribution from the steric term. Quantitative structure-activity relationship analysis of the binding affinities of the para-substituted benzylamine analogues to rat MAO A show an increased van der Waals volumes (Vw) increases the affinity of the deprotonated amine for the enzyme. These results demonstrate that rat MAO A exhibits similar but not identical functional properties with the human enzyme and provide additional support for C-H bond cleavage via a polar nucleophilic mechanism. PMID:21819071

Cloud-to-ground lightning activity in Colombia: A 14-year study using lightning location system data

NASA Astrophysics Data System (ADS)

Herrera, J.; Younes, C.; Porras, L.

2018-05-01

This paper presents the analysis of 14 years of cloud-to-ground lightning activity observation in Colombia using lightning location systems (LLS) data. The first Colombian LLS operated from 1997 to 2001. After a few years, this system was upgraded and a new LLS has been operating since 2007. Data obtained from these two systems was analyzed in order to obtain lightning parameters used in designing lightning protection systems. The flash detection efficiency was estimated using average peak current maps and some theoretical results previously published. Lightning flash multiplicity was evaluated using a stroke grouping algorithm resulting in average values of about 1.0 and 1.6 for positive and negative flashes respectively and for both LLS. The time variation of this parameter changes slightly for the years considered in this study. The first stroke peak current for negative and positive flashes shows median values close to 29 kA and 17 kA respectively for both networks showing a great dependence on the flash detection efficiency. The average percentage of negative and positive flashes shows a 74.04% and 25.95% of occurrence respectively. The daily variation shows a peak between 23 and 02 h. The monthly variation of this parameter exhibits a bimodal behavior typical of the regions located near The Equator. The lightning flash density was obtained dividing the study area in 3 × 3 km cells and resulting in maximum average values of 25 and 35 flashes km- 2 year- 1 for each network respectively. A comparison of these results with global lightning activity hotspots was performed showing good correlation. Besides, the lightning flash density variation with altitude shows an inverse relation between these two variables.

Air pollutants and toxic emissions of various mileage motorcycles for ECE driving cycles

NASA Astrophysics Data System (ADS)

Tsai, Jiun-Horng; Huang, Pei-Hsiu; Chiang, Hung-Lung

2017-03-01

Motorcycles were selected to determine their fuel consumption and exhaust emissions following ECE driving cycles. Exhaust constituents including CO2, CO, NOx, total hydrocarbons (THC) and hydrocarbon species (27 paraffins, 9 olefins, 16 aromatics and 15 carbonyls) were investigated for this work. The age of 10- 90% of the selected motorcycles ranged from 2.5 to 12.4 years, and their mileage ranged from 5400 to 39,300 km. CO emission ranged from 1.4 to 6.4 g/km (median value: 2.98 g/km), THC from 0.41 to 1.54 g/km (median value: 0.98 g/km), NOx from 0.16 to 0.28 g/km (median value: 0.21 g/km), CO2 from 58.9 to 62.2 g/km (median value: 60.5 g/km) and fuel consumption from 30.7 to 36.4 km/L (median value: 33.4 km/L), corresponding to the percentage cumulative data from 10 to 90% of the selected motorcycles. Results indicated that the motorcycle exhaust emission and fuel consumption depended on their mileage and ages. An increase in mileage of 1000 km resulted in an increase of 103 mg for CO emission and 14.7 mg for hydrocarbon emission and a reduction of 1.52 mg NOx emission and 0.11 km per liter fuel consumption. For various VOC groups, a mileage increase of 1000 km corresponding to the increased exhaust emission of paraffins was 6.71 mg, olefins 1.90 mg, aromatics 7.04 mg, carbonyls 0.283 mg and 67 VOC species 15.9 mg. Fuel consumption and emissions of CO and hydrocarbon increased in motorcycles over the guaranteed mileage of 15,000 km.

First detection of HDO in the atmosphere of Venus at radio wavelengths - An estimate of the H2O vertical distribution

NASA Technical Reports Server (NTRS)

Encrenaz, T.; Lellouch, E.; Paubert, G.; Gulkis, S.

1991-01-01

The 225.9 GHz line of HDO has been detected in absorption in the atmosphere of Venus, with the 30-m IRAM antenna. This measurement gives information regarding the vertical distributions of HDO, and thus H2O, in this planet. The observations are consistent with an H2O vertical distribution strongly depleted by saturation at an altitude of 95 km, and, assuming a D/H enrichment of 120 with respect to the terrestrial value, with a mixing ratio of 3.5 (+ or - 2.0) ppm in the range 65-95 km.

Biochemical characterization of recombinant mevalonate kinase from Bacopa monniera.

PubMed

Kumari, Uma; Vishwakarma, Rishi K; Sonawane, Prashant; Abbassi, Shakeel; Khan, Bashir M

2015-01-01

Mevalonate kinase (MK; ATP: mevalonate 5-phosphotransferase; EC 2.7.1.36) plays a key role in isoprenoid biosynthetic pathway in plants. MK catalyzes the phosphorylation of mevalonate to form mevalonate-5-phosphate. The recombinant BmMK was cloned and over-expressed in E. coli BL21 (DE3), and purified to homogeneity by affinity chromatography followed by gel filtration. Optimum pH and temperature for forward reaction was found to be 7.0 and 30 °C, respectively. The enzyme was most stable at pH 8 at 25 °C with deactivation rate constant (Kd*) 1.398 × 10(-4) and half life (t1/2) 49 h. pH activity profile of BmMK indicates the involvement of carboxylate ion, histidine, lysine, arginine or aspartic acid at the active site of enzyme. Activity of recombinant BmMK was confirmed by phosphorylation of RS-mevalonate in the presence of Mg(2+), having Km and Vmax 331.9 μM and 719.1 pKat μg(-1), respectively. The values of kcat and kcat/Km for RS-mevalonate were determined to be 143.82 s(-1) and 0.43332 M(-1) s(-1) and kcat and kcat/Km values for ATP were found 150.9 s(-1) and 1.023 M(-1) s(-1). The metal ion studies suggested that BmMK is a metal dependent enzyme and highly active in the presence of MgCl2. Copyright © 2014 Elsevier B.V. All rights reserved.

Bacopa monniera recombinant mevalonate diphosphate decarboxylase: Biochemical characterization.

PubMed

Abbassi, Shakeel J; Vishwakarma, Rishi K; Patel, Parth; Kumari, Uma; Khan, Bashir M

2015-08-01

Mevalonate diphosphate decarboxylase (MDD; EC 4.1.1.33) is an important enzyme in the mevalonic acid pathway catalyzing the Mg(2+)-ATP dependant decarboxylation of mevalonate 5-diphosphate (MVAPP) to isopentenyl diphosphate (IPP). Bacopa monniera recombinant MDD (BmMDD) protein was overexpressed in Escherichia coli BL21 (DE3) strain and purified to apparent homogeneity. Km and Vmax for MVAPP were 144 μM and 52 U mg(-1) respectively. The values of turnover (kcat) and kcat/Km for mevalonate 5-diphosphate were determined to be 40s(-1) and 2.77×10(5) M(-1) s(-1) and kcat and kcat/Km values for ATP were found to be 30 s(-1) and 2.20×10(4) M(-1) s(-1), respectively. pH activity profile indicated the involvement of carboxylate ion, lysine and arginine for the activity of enzyme. The apparent activation energy for the BmMDD catalyzed reaction was 12.7 kJ mol(-1). Optimum pH and temperature for the forward reaction was found to be 8.0 and 45 °C. The enzyme was most stable at pH 7 at 20 °C with the deactivation rate constant (Kd(*)) of 1.69×10(-4) and half life (t1/2) of 68 h. The cation studies suggested that BmMDD is a cation dependant enzyme and optimum activity was achieved in the presence of Mg(2+). Copyright © 2015 Elsevier B.V. All rights reserved.

Cl/B ratio of geothermal fluid around Slamet Volcano, Jawa Tengah, Indonesia

NASA Astrophysics Data System (ADS)

Harijoko, Agung; Juhri, Saefudin

2017-12-01

Geothermal manifestations occurred in four areas surrounding Slamet Volcano, such as Guci, Baturraden, Paguyangan, and Bantarkawung. These areas are located of about 7.5 km, 8 km, 25 km and 33 km from the summit of Slamet volcano, respectively. We analyzed the chemical composition of cold and hot hater in order to understand the genesis and hydrological the relationship of the hot springs. The plot on HCO3-Cl-SO4 ternary diagram classified the hot water into four water types i.e. chloride-bicarbonate water (Bantarkawung), chloride water (Paguyangan), sulfate-chloride water (Baturraden), and bicarbonate water (Guci). The Cl/B ratio values indicate that the southern part of the Slamet volcano (Baturaden) hot springs have high Cl/B ratio compared to that of the northern hot springs (Guci area). While the hot springs in the western part (Paguyangan and Bantarkawung) are classified into high and low Cl/B ratio. This indicates that the hot springs in Paguyangan and Bantarkawung are the outflow of Baturraden and Guci.

Plastic pollution in the South Pacific subtropical gyre.

PubMed

Eriksen, Marcus; Maximenko, Nikolai; Thiel, Martin; Cummins, Anna; Lattin, Gwen; Wilson, Stiv; Hafner, Jan; Zellers, Ann; Rifman, Samuel

2013-03-15

Plastic marine pollution in the open ocean of the southern hemisphere is largely undocumented. Here, we report the result of a (4489 km) 2424 nautical mile transect through the South Pacific subtropical gyre, carried out in March-April 2011. Neuston samples were collected at 48 sites, averaging 50 nautical miles apart, using a manta trawl lined with a 333 μm mesh. The transect bisected a predicted accumulation zone associated with the convergence of surface currents, driven by local winds. The results show an increase in surface abundance of plastic pollution as we neared the center and decrease as we moved away, verifying the presence of a garbage patch. The average abundance and mass was 26,898 particles km(-2) and 70.96 g km(-2), respectively. 88.8% of the plastic pollution was found in the middle third of the samples with the highest value of 396,342 particles km(-2) occurring near the center of the predicted accumulation zone. Copyright © 2013 Elsevier Ltd. All rights reserved.

Vertical Distribution of NO, NO(2), and HNO(3) as Derived from Stratospheric Absorption Infrared Spectra.

PubMed

Fontanella, J C; Girard, A; Gramont, L; Louisnard, N

1975-04-01

This paper is devoted to the results concerning NO, NO(2), and HNO(3) obtained during airborne experiments performed in June-July 1973 on Concorde 001. The altitude of flight was about 16 km. Results concerning NO are, within the accuracy of measurement, in agreement with results of a previousspectrometric balloonborne experiment conducted jointly by IASB and ONERA (14 May 1973). Nitric oxide is concentrated in stratospheric layers clearly above the flight altitude. Integrated amount of NO along the optical path is (4 +/- 1.5) x 10(16) mol cm(-2) for a solar elevation varying from +2 degrees above the horizontal plane to -1 degrees . A value of 6 x 10(8) mol cm(-3) may be given as an upper limit for the local concentration at the flight altitude. Thereis no significant difference in the integrated amount observed at sunset and sunrise. Measured value of NO(2) local concentration at 15.5 km is (1.1 +/- 0.2) x 10(9) mol cm(-3), in sunset conditions. This value is not greatly modified between 15 km and 30 km. Measured value of HNO(3). This value increases with altitude between 15 km and 20 km. The local concentration is maximum at 20 km. The measured value is (2 +/- 1) x 10(10) mol cm(-3) at 20 km. It seems that local concentration decreases rapidly above 20 km.

The two-step electrochemical oxidation of alcohols using a novel recombinant PQQ alcohol dehydrogenase as a catalyst for a bioanode.

PubMed

Takeda, Kouta; Matsumura, Hirotoshi; Ishida, Takuya; Samejima, Masahiro; Igarashi, Kiyohiko; Nakamura, Nobuhumi; Ohno, Hiroyuki

2013-12-01

A bioanode has been developed based on the oxidation of ethanol by the recombinant pyrroloquinoline quinone (PQQ) dependent alcohol dehydrogenase from Pseudomonas putidaKT2440 heterologously expressed in Pichia pastoris. The apo form of the recombinant protein (PpADH) was purified and displayed catalytic activity for binding PQQ in the presence of Ca(2+). PpADH exhibited broad substrate specificity towards various alcohols and aldehydes. The Km values for the aldehydes of PpADH were increased compared to those for the alcohols, whereas the kcat values were unaltered. For instance, the Km values at T=298.15K (25 °C) for ethanol and acetaldehyde were 0.21 (± 0.02)mM and 5.8 (± 0.60)mM, respectively. The kcat values for ethanol and acetaldehyde were 24.8 (± 1.2) s(-1) and 31.1 (± 1.2) s(-1), respectively. The aminoferrocene was used as an electron transfer mediator between PpADH and the electrode during electrochemical experiments. The catalytic currents for the oxidation of alcohol and acetaldehyde by PpADH were also observed in this system. The electric charge for the oxidation of ethanol (Q = 2.09 × 10(-3) · C) was increased two-fold compared to that for the oxidation of acetaldehyde (Q = 0.95 × 10(-3) · C), as determined by chronoamperometric measurements. Thus, we have electrochemically demonstrated the two-step oxidation of ethanol to acetate using only PpADH. © 2013.

Magmatic Flow Record From AMS Data La Gloria Pluton, Central Chile

NASA Astrophysics Data System (ADS)

Gutierrez, F.; Payacan, I. J.; Calderon, S.

2011-12-01

La Gloria Pluton (LGP) is a 10 Ma epizonal intrusion in the Southern Andes, located 40 km east of Santiago, in central Chile. 20 km long and 5 km wide LPG has a thickness of 2.5 km, in the form of a NW elongating inverted canoe. LGP intrudes Miocene volcanics as NS extending cluster of Miocene granitoids. LGP was emplaced at the west of an inverse fault system without exhibiting significant post-intrusion deformation. The fault system includes the Laguna Negra Fault and the El Coironal Fault, at its southern and northern ends respectively. LGP has been interpreted to have had a short cooling time, where subsolidus reequilibration was not pervasive, allowing identification of early and late magmatic conditions and suggesting it to be a single closed chamber. LGP is zoned vertically from granodiorite/quartz monzodiorite to quartz monzonite towards the roof, where hornblende and biotite and minor magnetite-ilmenite are omnipresent. AMS samples were collected at 39 sites to determine of the magnetic anisotropy susceptibility tensor. Magnetic fabric is generally oblate and anisotropy values range from 1.3 to 13.9%, consistent with the prescience magnetite and ilmenite. Magnetic lineation (ML) has a NNW trend, a subhorizontal dip and values between 0.4 and 5.3%. Magnetic foliation (MF) has a NW trend and dip varying from vertical at the walls of the intrusive to subhorizontal inside and under the roof. MF values ranges between 0.8 and 13.3%. Since linear trend of MF is restricted to the LGP interior only and can not be caused by a simple inverse fault system, we interpret the AMS results as a consequence of magmatic flow. ML represents the main flow direction, where several shallow plutons intrude at 10Ma in NW direction. MF is consequence of convection, related to cooling and differentiation, and is comparable to numerical simulations of magma fluid-dynamics during differentiation (R4). Two profiles (EW and NS) indicate that MF linear trend is from 29°/km to 50°/km, where the width of the pluton is 6 and 3.5 km respectively. Vertical MF represents vertical magma flows at the walls, whereas horizontal MF represents horizontal magma flow at the interior and under the roof the chamber. This suggests that a generalization of the MF trend allows determining the subsurface width of a pluton. Acknowledgments This research has been developed by the PBCT-PDA07 project and the FONDECYT (National Fund for Scientific & Technological Development) 11100241 project, both granted by CONICYT (Chilean National Commission for Science and Technology). We thank 4ea for logistic support in field activities in an area difficult to access.

Influence of cimetidine and diethyldithiocarbamate on the metabolism of halothane and methoxyflurane in vitro.

PubMed

Loesch, J; Siegers, C P; Younes, M

1987-06-01

The metabolism of halothane and methoxyflurane was measured in vitro by the vial equilibration method using the S-9-fraction from rat liver as source of enzymes. Kinetic values were measured for halothane: Vmax = 11.6 nmol/g.min, KM = 19.6 mumol/l and methoxyflurane: Vmax = 12.0 nmol/g.min, KM = 17.5 mumol/l. Dithiocarb showed strong inhibitory activity on halothane and methoxyflurane metabolism; inhibition constants were calculated as Ki = 0.051 mmol/l and Ki = 0.004 mmol/l, respectively. Cimetidine inhibited the metabolism of both anesthetics to a lesser extent. Inhibition constants were calculated as Ki = 16.2 mmol/l and Ki = 8.2 mmol/l for halothane and methoxyflurane, respectively. The observed inhibitory properties of dithiocarb and cimetidine on the metabolism of halothane and methoxyflurane may be of interest in connection with the problem of toxic liver and kidney injury after anesthesia with these agents.

Traveltimes and amplitudes from nuclear explosions; Nevada Test Site to Ordway, Colorado

USGS Publications Warehouse

Ryall, Alan; Stuart, David J.

1963-01-01

This paper treats the results of a study of seismic waves generated by eight nuclear explosions and recorded at 31 locations between the Nevada Test Site (NTS) and Ordway, Colorado. The line of recording stations crosses the eastern part of the Basin and Range Province, the Colorado Plateau, the southern Rocky Mountains, and extends into the Great Plains. In the eastern Basin and Range Province and the western margin of the Colorado Plateau (0 ≤ Δ ≤ 385 km ), the time-distance curves for Pg and Pn can be expressed, respectively, as T1 = 0.8 + Δ/6.0. T3 = 5.8 + Δ/7.6. A third phase, tentatively identified as P*, is represented by the equation T2 = 3.8 + Δ/6.5. Using the crustal structure and Pn velocity (7.9 km/ sec) found for the NTS region by other authors, these relations indicate that the thickness of the crust increases from about 25 km at NTS to about 42 km in the western part of the Colorado Plateau Province. East of this boundary the velocity of P in the upper mantle increases to 8.0 km/sec; depth to the Mohorovicic discontinuity is approximately constant over the range 435 ≤ Δ ≤ 645 km. Beyond 850 km, first arrivals indicate an apparent velocity of about 8.4 km/sec. Amplitudes of Pn attenuate according to the equation A = Ao Δ-1/2(Δ -d)-3/2 e-0.0022Δ over the distance range 150 ≤ Δ ≤ 850 km. This relation yields a value of Q, for Pn of about 520. The amplitudes of Pg attenuates extremely rapidly, and beyond about 130 km this phase cannot be identified with certainty. An extension of the Pg traveltime branch at large distances could be associated with waves reflected beyond the critical angle, from the base of the crust. This phase, called ?P after Mohorovicic, appears to attenuate as A = Ao e-0.076Δ Δ-1/2. The value of Q indicated by this equation is about 200.

The 0.57 Ma plinian eruption of the Granadilla Member, Tenerife (Canary Islands): an example of complexity in eruption dynamics and evolution

NASA Astrophysics Data System (ADS)

Bryan, S. E.; Cas, R. A. F.; Martí, J.

2000-12-01

The Granadilla Member is one of the most widely dispersed and largest volume pyroclastic units at Tenerife (Canary Islands) and represents the culminating eruption to a second cycle of explosive volcanism of the Las Cañadas edifice. The member, dated at 0.57 Ma, comprises a plinian fall deposit, the Granadilla pumice, which is overlain by ignimbrite up to 30 m thick. The Granadilla pumice is up to 9 m thick approximately 10 km from source (Pyle bt value is 5.35 km), and is subdivided into four fall units. Unit 1 is up to 1.2 m thick and is further divisible into another four pumice fall subunits, based on bedding and grainsize differences. Unit 2 is a thin but distinctive ash layer (˜2 cm thick), and its wide dispersal (>550 km2), constant thickness, planar laminations and ash aggregate textures collectively indicate a phreatoplinian fall origin. The lithic-rich nature and abundance of unaltered lithic fragments reflect magma interaction with aquifer-derived water at depth. Unit 3 (≤1.8 m thick), records a reversal to dry plinian eruptive activity. Unit 4, the thickest of the fall units (up to 6.3 m thick), records the maximum dispersal and intensity of the eruption (Pyle bt and bc values are 5.7 and 6.3 km, respectively), best illustrated by the presence of large pumice bombs up to 30 cm diameter (at distances up to 20 km from vent), and reverse grading of lithic and pumice clasts. The widespread (>500 km2), nonwelded and pumice-rich Granadilla ignimbrite (unit 5) records the collapse of the plinian eruption column. The ignimbrite has a simple sheet-like geometry, but exhibits a complex internal stratigraphy. The base of the ignimbrite locally cuts down through the underlying Granadilla pumice removing it entirely, indicating up to 9 m of erosion by the pyroclastic flows. A coarse, vent-derived lithic breccia horizon towards the top of the ignimbrite is interpreted to record the onset of caldera collapse late in the eruption. Minimum volume estimates for the Granadilla pumice and ignimbrite are 5.2 and 5 km3, respectively. The dispersal area, deposit characteristics, and exponential thickness and clast size decay relationships with (isopach area)1/2 are consistent with dispersal and fallout from the umbrella region of a moderately high (˜17 to ≥25 km) plinian column. We propose that the eruption involved two vents, probably aligned along a NE-SW fissure within the Las Cañadas caldera.

Density-lag anomaly patterns in backshore sands along a paraglacial barrier spit

NASA Astrophysics Data System (ADS)

Pupienis, Donatas; Buynevich, Ilya; Jarmalavičius, Darius; Fedorovič, Julija; Žilinskas, Gintautas; Ryabchuk, Daria; Kovaleva, Olga; Sergeev, Alexander; Cichon-Pupienis, Anna

2016-04-01

The Curonian Spit, located along the southeast Baltic Sea coast, is one of the longest paraglacial mega-barriers in the world (~100 km) and is characteried by microtidal sandy beaches and unbroken foredune ridge emplaced by human activities in historical times. Both are dominated by quartzo-feldpathic sand, with various fractions of heavy minerals that may be concentrated as density lag. Such heavy-mineral concentrations (HMCs) may be distributed weither randomly or regularly along the coast, depending on the geological framework, hydro-aeolian processes, and human activities (e.g., steel elements of coastal engineering structures, military installations, etc.). In this study, we focus on the longshore patterns in HMC distribution and relative magnitude (mainly the concentration of ferrimagnetic components). Along the entire Curonian Spit coast (Russia-Lithuania), a total of 184 surface sand samples were collected at 1 km interval from the berm and foredune toe (seaward base). HMCs were characterized in the laboratory using bulk low-field magnetic susceptibility (MS). The Wavelength and Lomb spectral analysis were used to assess the spatial rhythmicity of their longshore distribution. Generally, quartz sand is characterised by low MS values of ĸ<50 μSI, whereas higher values ĸ>150 μSI are typical for heavy mineral-rich sand. MS values on the berm and foredune toe range from 11.2-4977.9 μSI and from 9.2-3153.0 μSI, respectively. Density lag anomalies had MS values exceeding an average value by ≥3 times. Wavelength and Lomb spectral analysis allowed to identify several clusters of periodicities with wavelength varying from 2-12 km, with power spectra having statistically significant values (>95 % CI). Along the modern Curonian Spit coast, two scales of rhythmic pattern variation are evident: macroscale (≤12 km) and mesoscale (2-3 km). The former can be attributed to localized expressions of geological framework (iron-rich components) and engineering structures (especially within the southern part of the spit), whereas the mesoscale patterns reflect spatial distribution of short-term hydro-aeolian forcing (erosional-accretionary cells) that may shift temporally. This research was supported by Lithuanian Science Council (Grant No. MIP-039/2014), the Internationalization Program Award, Temple University and Russian Scientific Fund (Grant No. 14-37-00047).

Perceived environmental and health risks of nuclear energy in Taiwan after Fukushima nuclear disaster.

PubMed

Ho, Jung-Chun; Lee, Chiao-Tzu Patricia; Kao, Shu-Fen; Chen, Ruey-Yu; Ieong, Marco C F; Chang, Hung-Lun; Hsieh, Wan-Hua; Tzeng, Chun-Chiao; Lu, Cheng-Fung; Lin, Suei-Loong; Chang, Peter Wushou

2014-12-01

After the nuclear disaster in Fukushima in Japan in 2011, a nation-wide survey using a standardized self-administered questionnaire was conducted in Taiwan, with a sample size of 2,742 individuals including the residents who live within and beyond 30 km from a nuclear power plant (NPP), to evaluate the participants' perceived nuclear risk in comparison with their perceived risks from selected environmental hazards and human behaviors. The three leading concerns of nuclear energy were "nuclear accidents (82.2%)," "radioactive nuclear waste disposal (76.9%)" and "potential health effects (73.3%)." Respondents (77.6%) perceived a higher relative risk of cancer incidence for those who live within 30 km from an NPP than those who live outside 30 km from an NPP. All the participants had a higher risk perception of death related to "nuclear power operation and nuclear waste" than cigarette smoking, motorcycling, food poisoning, plasticizer poisoning and traveling by air. Moreover, the residents in Gongliao where the planned fourth NPP is located had a significantly higher perceived risk ratio (PRR) of cancer incidence (adjusted odd ratio (aOR)=1.84, p value=0.017) and perceived risk of death (aOR=4.03, p value<0.001) related to nuclear energy. The other factors such as female gender (aOR/p value, 1.25/0.026 and 1.34/0.001 respectively), lower education levels (aOR/p value: 1.31/0.032; 2.03/<0.001) and the participants' concerns about nuclear accidents (aOR/p value: 1.33/0.022; 1.51/<0.001) and potential health effects (aOR/ p value: 2.95/ <0.001; 2.56/<0.001) were found to be commonly associated with the PRRs of "cancer incidence" and "perceived risk of death" related to nuclear energy, respectively. In addition, the respondents' concerns about nuclear waste disposal and possible eco-environmental damage made significant contributions (aOR/ p value: 1.39/ 0.001; 1.40/<0.001) to predict their perceived risk of death related to nuclear power. These factors are considered as important indicators and they can be used for suggesting future policy amendments and public referendum on the decision of the operation of the planned NPP. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ecological validity of the Yo-Yo SFIE2 test.

PubMed

Krustrup, P; Randers, M; Horton, J; Brito, J; Rebelo, A

2012-06-01

The present study investigated the movement pattern of Portuguese top-level futsal referees (n=16) during competitive games and the ecological validity of the new Yo-Yo Sideways-Forwards Intermittent Endurance level 2 test (Yo-Yo SFIE2). Total distance covered (TD), high-intensity running (HIR), sprinting (SPR), and sideways running (Sw) during matches were 5.78±0.24 (±SEM), 0.77±0.08, 0.17±0.02 and 1.61±0.28 km, respectively, with peak 5-min values of 0.50±0.02, 0.12±0.01, 0.05±0.01 and 0.20±0.02 km, respectively. TD, HIR and Sw decreased by 30% (p<0.001), 43% and 60% (p<0.01), respectively from the first to the last 10-min period. Yo-Yo SFIE2 performance was 1205±107 (625-2015) m and showed large correlations with match-values and peak 5-min values for HIR (r=0.58 and 0.68, p<0.01) and SPR (r=0.56 and 0.57, p<0.05). Yo-Yo SFIE2 HR after 4 min [95±1 (87-99) % HRpeak] showed a nearly perfect inverse correlation with Yo-Yo SFIE2 performance (r= -0.90, p<0.001) and large inverse correlations (p<0.05) with match-values and peak 5-min values for HIR (r= -0.55 and -0.71) and SPR (r= -0.57 and -0.55). In conclusion, the Yo-Yo SFIE2 test is movement-specific for top-level futsal referees as high-intensity running and sideways running are important parts of their match activity profile, and maximal and sub-maximal versions of the Yo-Yo SFIE2 test correlates with certain aspects of the physical match performance of top-level futsal referees. © Georg Thieme Verlag KG Stuttgart · New York.

VizieR Online Data Catalog: Outer satellites occultation predictions (Gomes-Junior+, 2016)

NASA Astrophysics Data System (ADS)

Gomes-Junior, A. R.; Assafin, M.; Beauvalet, L.; Desmars, J.; Vieira-Martins, R.; Camargo, J. I. B.; Morgado, B. E.; Braga-Ribas, F.

2016-07-01

Tables contain the day of the year and UTC central instant of the prediction; right ascension and declination of the occulted star - at the central instant of the occultation (corrected by proper motions); C/A: apparent geocentric distance between the satellite and the star (a.k.a. the distance between the shadow and the center of the Earth) at the moment of the geocentric closest approach, in arcseconds; P/A: the satellite position angle with respect to the occulted star at C/A, in degrees (zero at north of the star, increasing clockwise); v: relative velocity of event in km/s: positive = prograde, negative = retrograde; D: Geocentric distance to the occulting object in AU; R*: normalized UCAC4 magnitude in the R-band to a common shadow of 20km/s by the relationship R*=RUCAC4+2.5xlog(velocity/(20km/s)), the value 20km/s is typical of events around the opposition; long: east longitude of subplanet point in degrees, positive towards east, at the instant of the geocentric closest approach; LST: UT + long: local solar time at subplanet point, hh:mm; pmra and pmdec: proper motions in right ascension and declination, respectively (mas/year). For more detailed information about the definition and use of these stellar occultation geometric elements see Assafin et al. (2010, Cat. J/A+A/515/A32). (2 data files).

A novel NADP(+)-dependent dehydrogenase activity for 7alpha/beta- and 11beta-hydroxysteroids in human liver nuclei: A third 11beta-hydroxysteroid dehydrogenase.

PubMed

Robinzon, B; Prough, R A

2009-06-15

Human tissue from uninvolved liver of cancer patients was fractionated using differential centrifugation and characterized for 11betaHSD enzyme activity against corticosterone, dehydrocorticosterone, 7alpha- and 7beta-hydroxy-dehydroepiandrosterone, and 7-oxo-dehydroepiandrosterone. An enzyme activity was observed in nuclear protein fractions that utilized either NADP(+) or NAD(+), but not NADPH and NADH, as pyridine nucleotide cofactor with K(m) values of 12+/-2 and 390+/-2microM, compared to the K(m) for microsomal 11betaHSD1 of 43+/-8 and 264+/-24microM, respectively. The K(m) for corticosterone in the NADP(+)-dependent nuclear oxidation reaction was 102+/-16nM, compared to 4.3+/-0.8microM for 11betaHSD1. The K(cat) values for nuclear activity with NADP(+) was 1687nmol/min/mg/micromol, compared to 755nmol/min/mg/micromol for microsomal 11betaHSD1 activity. Inhibitors of 11betaHSD1 decreased both nuclear and microsomal enzyme activities, suggesting that the nuclear activity may be due to an enzyme similar to 11betaHSD Type 1 and 2.

A Novel NADP+- Dependent Dehydrogenase Activity for 7 α/β and 11 β-hydroxysteroids in human liver nuclei: A Third 11 β-Hydroxysteroid Dehydrogenase

PubMed Central

Robinzon, B.; Prough, R.A.

2009-01-01

Human tissue from uninvolved liver of cancer patients was fractionated using differential centrifugation and characterized for 11βHSD enzyme activity against corticosterone, dehydrocorticosterone, 7α and 7β-hydroxy-dehydroepiandrosterone, and 7-oxodehydroepiandrosterone. An enzyme activity was observed in nuclear protein fractions that utilized either NADP+ or NAD+, but not NADPH and NADH, as pyridine nucleotide cofactor with Km values of 12 ± 2 and 390 ± 2 μM, compared to the Km for microsomal 11βHSD1 of 43 ± 8 and 264 ± 24 μM, respectively. The Km for corticosterone in the NADP+-dependent nuclear oxidation reaction was 102 ± 16 nM, compared to 4.3 ± 0.8 μM for 11βHSD1. The Kcat values for nuclear activity with NADP+ was 1,687 nmol/min/mg/μmol, compared to 755 nmol/min/mg/μmol for microsomal 11βHSD1 activity. Inhibitors of 11βHSD1 decreased both nuclear and microsomal enzyme activities, suggesting that the nuclear activity may be due to an enzyme similar to 11βHSD Type 1 and 2. PMID:19416720

The color temperature of (2060) Chiron: A warm and small nucleus

NASA Technical Reports Server (NTRS)

Campins, H.; Telesco, C. M.; Osip, D. J.; Rieke, G. H.; Rieke, M. J.; Schulz, B.

1994-01-01

We present three sets of thermal-infrared observations of (2060) Chiron, obtained in 1991, 1993, and 1994. These observations allow the first estimates of the color temperature of Chiron as well as refined estimates of the radius and albedo of its nucleus. 10/20 micrometer color temperatures of 126(sub -6 sup +11) and 137(sub -9 sup +14) K are obtained from the 1993 and 1994 observations, respectively. These temperatures are consistent with the Standard Thermal Model (STM; Lebofsky & Spencer, 1989), but significantly higher than those predicted by the Isothermal Latitude Model. Our estimates of Chiron's radius based on the STM are in agreement with each other, with the observations of Lebofsky et al. (1984), and with recent occultation results (Buie et al., (1993). We obtained values for the radius of 74 +/- 11 km in 1991, 88 +/- 10 and 104 +/- 10 km in 1993, and, 94 +/- 6 and 91 +/- 13 km in 1994.

Regional-Scale High-Latitude Extreme Geoelectric Fields Pertaining to Geomagnetically Induced Currents

NASA Technical Reports Server (NTRS)

Pulkkinen, Antti; Bernabeu, Emanuel; Eichner, Jan; Viljanen, Ari; Ngwira, Chigomezyo

2015-01-01

Motivated by the needs of the high-voltage power transmission industry, we use data from the high-latitude IMAGE magnetometer array to study characteristics of extreme geoelectric fields at regional scales. We use 10-s resolution data for years 1993-2013, and the fields are characterized using average horizontal geoelectric field amplitudes taken over station groups that span about 500-km distance. We show that geoelectric field structures associated with localized extremes at single stations can be greatly different from structures associated with regionally uniform geoelectric fields, which are well represented by spatial averages over single stations. Visual extrapolation and rigorous extreme value analysis of spatially averaged fields indicate that the expected range for 1-in-100-year extreme events are 3-8 V/km and 3.4-7.1 V/km, respectively. The Quebec reference ground model is used in the calculations.

Geomagnetism during solar cycle 23: Characteristics

PubMed Central

Zerbo, Jean-Louis; Amory-Mazaudier, Christine; Ouattara, Frédéric

2012-01-01

On the basis of more than 48 years of morphological analysis of yearly and monthly values of the sunspot number, the aa index, the solar wind speed and interplanetary magnetic field, we point out the particularities of geomagnetic activity during the period 1996–2009. We especially investigate the last cycle 23 and the long minimum which followed it. During this period, the lowest values of the yearly averaged IMF (3 nT) and yearly averaged solar wind speed (364 km/s) are recorded in 1996, and 2009 respectively. The year 2003 shows itself particular by recording the highest value of the averaged solar wind (568 km/s), associated to the highest value of the yearly averaged aa index (37 nT). We also find that observations during the year 2003 seem to be related to several coronal holes which are known to generate high-speed wind stream. From the long time (more than one century) study of solar variability, the present period is similar to the beginning of twentieth century. We especially present the morphological features of solar cycle 23 which is followed by a deep solar minimum. PMID:25685427

Fault parameters and macroseismic observations of the May 10, 1997 Ardekul-Ghaen earthquake

NASA Astrophysics Data System (ADS)

Amini, H.; Zare, M.; Ansari, A.

2018-01-01

The Ardekul (Zirkuh) earthquake (May 10, 1997) is the largest recent earthquake that occurred in the Ardekul-Ghaen region of Eastern Iran. The greatest destruction was concentrated around Ardekul, Haji-Abad, Esfargh, Pishbar, Bashiran, Abiz-Qadim, and Fakhr-Abad (completely destroyed). The total surface fault rupture was about 125 km with the longest un-interrupted segment in the south of the region. The maximum horizontal and vertical displacements were reported in Korizan and Bohn-Abad with about 210 and 70 cm, respectively; moreover, other building damages and environmental effects were also reported for this earthquake. In this study, the intensity value XI on the European Macroseismic Scale (EMS) and Environmental Seismic Intensity (ESI) scale was selected for this earthquake according to the maximum effects on macroseismic data points affected by this earthquake. Then, according to its macroseismic data points of this earthquake and Boxer code, some macroseismic parameters including magnitude, location, source dimension, and orientation of this earthquake were also estimated at 7.3, 33.52° N-59.99° E, 75 km long and 21 km wide, and 152°, respectively. As the estimated macroseismic parameters are consistent with the instrumental ones (Global Centroid Moment Tensor (GCMT) location and magnitude equal 33.58° N-60.02° E, and 7.2, respectively), this method and dataset are suggested not only for other instrumental earthquakes, but also for historical events.

Optimal design for crosstalk analysis in 12-core 5-LP mode homogeneous multicore fiber for different lattice structure

NASA Astrophysics Data System (ADS)

Kumar, Dablu; Ranjan, Rakesh

2018-03-01

12-Core 5-LP mode homogeneous multicore fibers have been proposed for analysis of inter-core crosstalk and dispersion, with four different lattice structures (circular, 2-ring, square lattice, and triangular lattice) having cladding diameter of 200 μm and a fixed cladding thickness of 35 μm. The core-to-core crosstalk impact has been studied numerically with respect to bending radius, core pitch, transmission distance, wavelength, and core diameter for all 5-LP modes. In anticipation of further reduction in crosstalk levels, the trench-assisted cores have been incorporated for all respective designs. Ultra-low crosstalk (-138 dB/100 km) has been achieved through the triangular lattice arrangement, with trench depth Δ2 = -1.40% for fundamental (LP01) mode. It has been noted that the impact of mode polarization on crosstalk behavior is minor, with difference in crosstalk levels between two polarized spatial modes as ≤0.2 dB. Moreover, the optimized cladding diameter has been obtained for all 5-LP modes for a target value of crosstalk of -50 dB/100 km, with all the core arrangements. The dispersion characteristic has also been analyzed with respect to wavelength, which is nearly 2.5 ps/nm km at operating wavelength 1550 nm. The relative core multiplicity factor (RCMF) for the proposed design is obtained as 64.

Human plasma kallikrein and tissue kallikrein binding to a substrate based on the reactive site of a factor Xa inhibitor isolated from Bauhinia ungulata seeds.

PubMed

Oliva, M L; Andrade, S A; Batista, I F; Sampaio, M U; Juliano, M; Fritz, H; Auerswald, E A; Sampaio, C A

1999-12-01

Kunitz type Bauhinia ungulata factor Xa inhibitor (BuXI) was purified from B. ungulata seeds. BuXI inactivates factor Xa and human plasma kallikrein (HuPK) with Ki values of 18.4 and 6.9 nM, respectively. However, Bauhinia variegata trypsin inhibitor (BvTI) which is 70% homologous to BuXI does not inhibit factor Xa and is less efficient on HuPK (Ki = 80 nM). The comparison between BuXI and BvTI reactive site structure indicates differences at Met59, Thr66 and Met67 residues. The hydrolysis rate of quenched fluorescence peptide substrates based on BuXI reactive site sequence, Abz-VMIAALPRTMFIQ-EDDnp (leading peptide), by HuPK and porcine pancreatic kallikrein (PoPK) is low, but hydrolysis is enhanced with Abz-VMIAALPRTMQ-EDDnp, derived from the leading peptide shortened by removing the dipeptide Phe-Ileu from the C-terminal portion, for HuPK (Km = 0.68 microM, k(cat)/Km = 1.3 x 10(6) M(-1) s(-1)), and the shorter substrate Abz-LPRTMQ-EDDnp is better for PoPK (Km = 0.66 microM, k(cat)/Km = 2.2 x 10(3) M(-1) s(-1)). The contribution of substrate methionine residues to HuPK and PoPK hydrolysis differs from that observed with factor Xa. The determined Km and k(cat) values suggest that the substrates interact with kallikreins the same as an enzyme and inhibitor interacts to form complexes.

Bounds on strain in large Tertiary shear zones of SE Asia from boudinage restoration

NASA Astrophysics Data System (ADS)

Lacassin, R.; Leloup, P. H.; Tapponnier, P.

1993-06-01

We have used surface-balanced restoration of stretched, boudinaged layers to estimate minimum amounts of finite strain in the mylonitic gneisses of the Oligo-Miocene Red River-Ailao Shan shear zone (Yunnan, China) and of the Wang Chao shear zone (Thailand). The layer-parallel extension values thus obtained range between 250 and 870%. We discuss how to use such extension values to place bounds on amounts of finite shear strain in these large crustal shear zones. Assuming simple shear, these values imply minimum total and late shear strains of, respectively, 33 ± 6 and 7 ± 3 at several sites along the Red River-Ailao Shan shear zone. For the Wang Chao shear zone a minimum shear strain of 7 ± 4 is deduced. Assuming homogeneous shear would imply that minimum strike-slip displacements along these two left-lateral shear zones, which have been interpreted to result from the India-Asia collision, have been of the order of 330 ± 60 km (Red River-Ailao Shan) and 35 ± 20 km (Wang Chao).

Inhibition, by 2-oxo acids that accumulate in maple-syrup-urine disease, of lactate, pyruvate, and 3-hydroxybutyrate transport across the blood-brain barrier.

PubMed

Cremer, J E; Teal, H M; Cunningham, V J

1982-09-01

Data are presented in support of the transport of (-)-D-3-hydroxybutyrate across the blood-brain barrier (BBB) being a carrier-mediated process. The kinetic parameters in 21-day-old pentobarbital-anaesthetized rats were Vmax 2.0 mumol.g-1.min-1, Km 29 mM, and KD 0.024 ml.g-1.min-1. The value for Vmax was the same as that for L-lactate and pyruvate transport in animals of the same age. The transport of all three substrates was sensitive to inhibition by low concentrations of either 2-oxo-3-methylbutanoate or 2-oxo-4-methylpentanoate, the 2-oxo acids that can accumulate in patients with maple-syrup-urine disease. The Ki values for the 2-oxo acids were severalfold lower than the respective Km values. 2-Oxo-3-phenylpropionate was a poor inhibitor. The relative affinities of the various monocarboxylic acids for the transport system of the BBB distinguished it from similar systems described in brain, heart, and liver mitochondria; human erythrocytes; and Ehrlich ascites-tumour cells.

Vertical profiles of H2O, H2SO4, and sulfuric acid concentration at 45-75 km on Venus

NASA Astrophysics Data System (ADS)

Krasnopolsky, Vladimir A.

2015-05-01

A method developed by Krasnopolsky and Pollack (Krasnopolsky, V.A., Pollack, J.B. [1994]. Icarus 109, 58-78) to model vertical profiles of H2O and H2SO4 vapors and sulfuric acid concentration in the Venus cloud layer has been updated with improved thermodynamic parameters for H2O and H2SO4 and reduced photochemical production of sulfuric acid. The model is applied to the global-mean conditions and those at the low latitudes and at 60°. Variations in eddy diffusion near the lower cloud boundary are used to simulate variability in the cloud properties and abundances of H2O and H2SO4. The best version of the model for the global-mean condition results in a lower cloud boundary (LCB) at 47.5 km, H2SO4 peak abundance of 7.5 ppm at the LCB, and H2O mixing ratios of 7 ppm at 62 km and 3.5 ppm above 67 km. The model for low latitudes gives LCB at 48.5 km, the H2SO4 peak of 5 ppm, H2O of 8.5 ppm at 62 km and 3 ppm above 67 km. The model for 60° shows LCB at 46 km, the H2SO4 peak of 8.5 ppm, H2O of 9 ppm at 62 km and 4.5 ppm above 67 km. The calculated variability is induced by the proper changes in the production of sulfuric acid (by factors of 1.2 and 0.7 for the low latitudes and 60°, respectively) and reduction of eddy diffusion near 45 km relative to the value at 54 km by factors of 1.1, 3, and 4.5 for the low and middle (global-mean) latitudes and 60°, respectively. Concentration of sulfuric acid at the low and middle latitudes varies from ∼98% near 50 km to ∼80% at 60 km and then is almost constant at 79% at 70 km. Concentration at 60° is 98% at 50 km, 73% at 63 km, and 81% at 70 km. There is a reasonable agreement between the model results and observations except for the sulfuric acid concentration in the lower clouds. Variations of eddy diffusion in the lower cloud layer simulate variations in atmospheric dynamics and may induce strong variations in water vapor near the cloud tops. Variations in temperature may affect abundances of the H2O and H2SO4 vapors as well.

Some Lactobacillus l-Lactate Dehydrogenases Exhibit Comparable Catalytic Activities for Pyruvate and Oxaloacetate

PubMed Central

Arai, Kazuhito; Kamata, Takeo; Uchikoba, Hiroyuki; Fushinobu, Shinya; Matsuzawa, Hiroshi; Taguchi, Hayao

2001-01-01

The nonallosteric and allosteric l-lactate dehydrogenases of Lactobacillus pentosus and L. casei, respectively, exhibited broad substrate specificities, giving virtually the same maximal reaction velocity and substrate Km values for pyruvate and oxaloacetate. Replacement of Pro101 with Asn reduced the activity of the L. pentosus enzyme toward these alternative substrates to a greater extent than the activity toward pyruvate. PMID:11114942

[Reconstruction of urban land space based on minimum cumulative resistance model: a case study of Xintang Town, Guangzhou City].

PubMed

Zhong, Shi-Yu; Wu, Qing; Li, Yu; Cheng, Jin-Ping

2012-11-01

Based on the source-sink landscape theory and the principles of ecosystem services, the minimum cumulative resistance (MCR) model was modified, where the urban center construction land was taken as the expansion source, and the contribution rate of ecological land ecosystem services value was considered as the resistance coefficient. With the modified MCR, the urban spatial expansion process of Xintang Town, Guangzhou City was successfully simulated, and, based on the protection of ecological security pattern, the optimum path for reconstructing urban land space was put forward. The simulated urban spatial expansion short path in 1988-2008 was in accordance with the real situation. By the modified MCR, the urban space was divided into four zones of high, higher, medium, and low resistance, with the area of 80.84, 78.90, 24.26, and 61.88 km2, respectively. The expansion path of the urban space was along the route from low to medium and then to high resistance zones successively. The land suitable for eco-protection and construction had an area of 159.74 km2 and 86.14 km2, while the ecological conflict area (17.37 km2) was mainly located in higher and high resistance zones, being 10.38 and 6.99 km2, respectively. The modified MCR could not only effectively reflect the distribution area of urban land use and the conflict relationship between urban construction and ecological protection, but also reasonably judge the best developmental short path for urban spatial expansion.

A determination and comparison of urease activity in feces and fresh manure from pig and cattle in relation to ammonia production and pH changes.

PubMed

Dai, Xiaorong; Karring, Henrik

2014-01-01

Ammonia emission from animal production is a major environmental problem and has impacts on the animal health and working environment inside production houses. Ammonia is formed in manure by the enzymatic degradation of urinary urea and catalyzed by urease that is present in feces. We have determined and compared the urease activity in feces and manure (a urine and feces mixture) from pigs and cattle at 25°C by using Michaelis-Menten kinetics. To obtain accurate estimates of kinetic parameters Vmax and K'm, we used a 5 min reaction time to determine the initial reaction velocities based on total ammoniacal nitrogen (TAN) concentrations. The resulting Vmax value (mmol urea hydrolyzed per kg wet feces per min) was 2.06±0.08 mmol urea/kg/min and 0.80±0.04 mmol urea/kg/min for pig feces and cattle feces, respectively. The K'm values were 32.59±5.65 mmol urea/l and 15.43±2.94 mmol urea/l for pig feces and cattle feces, respectively. Thus, our results reveal that both the Vmax and K'm values of the urease activity for pig feces are more than 2-fold higher than those for cattle feces. The difference in urea hydrolysis rates between animal species is even more significant in fresh manure. The initial velocities of TAN formation are 1.53 mM/min and 0.33 mM/min for pig and cattle manure, respectively. Furthermore, our investigation shows that the maximum urease activity for pig feces occurs at approximately pH 7, and in cattle feces it is closer to pH 8, indicating that the predominant fecal ureolytic bacteria species differ between animal species. We believe that our study contributes to a better understanding of the urea hydrolysis process in manure and provides a basis for more accurate and animal-specific prediction models for urea hydrolysis rates and ammonia concentration in manures and thus can be used to predict ammonia volatilization rates from animal production.

A Determination and Comparison of Urease Activity in Feces and Fresh Manure from Pig and Cattle in Relation to Ammonia Production and pH Changes

PubMed Central

Dai, Xiaorong; Karring, Henrik

2014-01-01

Ammonia emission from animal production is a major environmental problem and has impacts on the animal health and working environment inside production houses. Ammonia is formed in manure by the enzymatic degradation of urinary urea and catalyzed by urease that is present in feces. We have determined and compared the urease activity in feces and manure (a urine and feces mixture) from pigs and cattle at 25°C by using Michaelis-Menten kinetics. To obtain accurate estimates of kinetic parameters Vmax and K'm, we used a 5 min reaction time to determine the initial reaction velocities based on total ammoniacal nitrogen (TAN) concentrations. The resulting Vmax value (mmol urea hydrolyzed per kg wet feces per min) was 2.06±0.08 mmol urea/kg/min and 0.80±0.04 mmol urea/kg/min for pig feces and cattle feces, respectively. The K'm values were 32.59±5.65 mmol urea/l and 15.43±2.94 mmol urea/l for pig feces and cattle feces, respectively. Thus, our results reveal that both the Vmax and K'm values of the urease activity for pig feces are more than 2-fold higher than those for cattle feces. The difference in urea hydrolysis rates between animal species is even more significant in fresh manure. The initial velocities of TAN formation are 1.53 mM/min and 0.33 mM/min for pig and cattle manure, respectively. Furthermore, our investigation shows that the maximum urease activity for pig feces occurs at approximately pH 7, and in cattle feces it is closer to pH 8, indicating that the predominant fecal ureolytic bacteria species differ between animal species. We believe that our study contributes to a better understanding of the urea hydrolysis process in manure and provides a basis for more accurate and animal-specific prediction models for urea hydrolysis rates and ammonia concentration in manures and thus can be used to predict ammonia volatilization rates from animal production. PMID:25397404

Production, purification and biochemical characterization of two laccase isoforms produced by Trametes versicolor grown on oak sawdust.

PubMed

Martínez-Morales, Fernando; Bertrand, Brandt; Pasión Nava, Angélica A; Tinoco, Raunel; Acosta-Urdapilleta, Lourdes; Trejo-Hernández, María R

2015-02-01

Two laccase isoforms (lcc1 and lcc2) produced by Trametes versicolor, grown on oak sawdust under solid-state fermentation conditions, were purified and characterized. The two isoforms showed significant biochemical differences. Lcc1 and lcc2 had MWs of 60 and 100 kDa, respectively. Both isoforms had maximal activity at pH 3 with ABTS and 2,6-dimethyloxyphenol (DMP). Lcc1 was the most attractive isoform due to its greater affinity towards all the laccase substrates used. Lcc1 had Km values of 12, 10, 15 and 17 mM towards ABTS, DMP, guaiacol and syringaldazine, respectively. Lcc2 had equivalent values of 45, 47, 15 and 39 mM. The biochemical properties of lcc1 substantiate the potential of this enzyme for application in the treatment of contaminated water with low pH values and high phenolic content.

Net anthropogenic nitrogen accumulation in the Beijing metropolitan region.

PubMed

Han, Yuguo; Li, Xuyong; Nan, Zhe

2011-03-01

A rapid increase in anthropogenic nitrogen inputs has a strong impact on terrestrial and aquatic ecosystems. We have estimated net anthropogenic nitrogen accumulation (NANA) as an index of nitrogen (N) pollution potential in the Beijing metropolitan region, China. Our research provides a basis for understanding the potential impact of anthropogenic N inputs on environmental problems, such as nation-wide water quality degradation under the current rapid urban expansion in modern China. The NANA estimation is based on an inventory of atmospheric N deposition, N fertilizer use, consumption of human food and animal feed, N fixation, and riverine N import and export. We calculated N accumulation values for the years 1991, 1997, 2003, and 2007. The average NANA values for the urban and suburban areas from 1991 to 2007 were 24,038 and 13,090 kg N km(-2) year(-1), respectively. NANA is higher in eastern and southern areas than in northern and western areas, and higher in the urban area than in the suburban area. The overall average NANA in Beijing has a downward trend from 15,187 kg N km(-2) year(-1) in 1991 to 11,606 kg N km(-2) year(-1) in 2007, but is still two to five times as that of developed countries. N input from nitrogenous fertilizer is the largest source of NANA, accounting for 44.4% (6,764 kg N km(-2) year(-1)) of the total N input, followed by atmospheric N deposition and N in human food and animal feed. NANA is closely related to land use, on average 23,140 kg N km(-2) year(-1) in densely populated developed land, 17,904 kg N km(-2) year(-1) in agricultural land, and 10,445 kg N km(-2) year(-1) in forest land. Human population density is the best single predictor of NANA.

Kinetic characterization of arginine deiminase and carbamate kinase from Streptococcus pyogenes M49.

PubMed

Hering, Silvio; Sieg, Antje; Kreikemeyer, Bernd; Fiedler, Tomas

2013-09-01

Streptococcus pyogenes (group A Streptococcus, GAS) is an important human pathogen causing mild superficial infections of skin and mucous membranes, but also life-threatening systemic diseases. S. pyogenes and other prokaryotic organisms use the arginine deiminase system (ADS) for survival in acidic environments. In this study, the arginine deiminase (AD), and carbamate kinase (CK) from S. pyogenes M49 strain 591 were heterologously expressed in Escherichia coli DH5α, purified, and kinetically characterized. AD and CK from S. pyogenes M49 share high amino acid sequence similarity with the respective enzymes from Lactococcus lactis subsp. lactis IL1403 (45.6% and 53.5% identical amino acids) and Enterococcus faecalis V583 (66.8% and 66.8% identical amino acids). We found that the arginine deiminase of S. pyogenes is not allosterically regulated by the intermediates and products of the arginine degradation (e.g., ATP, citrulline, carbamoyl phosphate). The Km and Vmax values for arginine were 1.13±0.12mM (mean±SD) and 1.51±0.07μmol/min/mg protein. The carbamate kinase is inhibited by ATP but unaffected by arginine and citrulline. The Km and Vmax values for ADP were 0.72±0.08mM and 1.10±0.10μmol/min/mg protein and the Km for carbamoyl phosphate was 0.65±0.07mM. The optimum pH and temperature for both enzymes were 6.5 and 37°C, respectively. Copyright © 2013 Elsevier Inc. All rights reserved.

Comparison of Keratometry Obtained by a Swept Source OCT-Based Biometer with a Standard Optical Biometer and Scheimpflug Imaging.

PubMed

Asena, Leyla; Akman, Ahmet; Güngör, Sirel Gür; Dursun Altınörs, Dilek

2018-04-09

To assess agreement of a swept source-optical coherence tomography (SS-OCT) based Biometer with a standard IOLMaster device and Scheimpflug Imaging (SI) to acquire keratometric measurements in cataract patients. In this prospective comparative study, 101 eyes of 101 cataract surgery candidates, aged 24-81 years, were sequentially examined using three devices. Keratometry values at the flat (K1) and steep (K2) axis, mean corneal power (Km) and magnitude of corneal astigmatism as well as J0 and J45 vectoral components of astigmatism obtained with the SS-OCT based biometer (IOLMaster 700) were compared with those obtained with the IOLMaster 500 and SI. The agreement between measurements was evaluated by the Bland-Altman method, intraclass correlation coefficients (ICCs) and repeated-measures analysis of variance. Mean K1 values from the three devices were similar (p = 0.09). Mean K2 and Km values of IOLMaster 700 were higher than SI and lower than IOLMaster 500 (p = 0.04 for K2 and p = 0.02 for Km). There was a strong correlation between K1, K2, Km and magnitude of astigmatism obtained with all devices (r ≥ 0.80 and p < 0.01). The 95% limits of agreement (LoA) width for each keratometric value were highest for the comparison between IOLMaster 500 and SI and lowest for the comparison between IOLMaster 700 and 500. The mean differences (width of 95% LoA) for J0 and J45 vectoral components were 0.005 (2.19) and 0.12 (2.92) for the measurements obtained by IOLMaster 700 vs IOLMaster 500 and 0.06 (1.79) and 0.02 (1.58) for the measurements obtained by IOLMaster 700 vs SI, respectively. With ICCs close to 1, the agreement between all devices was excellent for keratometric measurements. Mean K2, Km and astigmatism measurements from IOLMaster 700 were lower than IOLMaster 500 and higher than SI. However, the differences were quite small and are not expected to affect the final IOL power.

Attenuation of coda waves in the Aswan Reservoir area, Egypt

NASA Astrophysics Data System (ADS)

Mohamed, H. H.; Mukhopadhyay, S.; Sharma, J.

2010-09-01

Coda attenuation characteristics of Aswan Reservoir area of Egypt were analyzed using data recorded by a local earthquake network operated around the reservoir. 330 waveforms obtained from 28 earthquakes recorded by a network of 13 stations were used for this analysis. Magnitude of these earthquakes varied between 1.4 and 2.5. The maximum epicentral distance and depth of focus of these earthquakes were 45 km and 16 km respectively. Single back-scattering method was used for estimation of coda Q ( Qc). The Q0 values ( Qc at 1 Hz) vary between 54 and 100 and frequency dependence parameter " n" values vary between 1 and 1.2 for lapse time varying between 15 s and 60 s. It is observed that coda Q ( Qc) and related parameters are similar at similar lapse times to those observed for those for Koyna, India, where reservoir induced seismicity is also observed. For both regions these parameters are also similar to those observed for tectonically active regions of the world, although Aswan is located in a moderately active region and Koyna is located in a tectonically stable region. However, Qc does not increase uniformly with increasing lapse time, as is observed for several parts of the world. Converting lapse time to depth/distance it is observed that Qc becomes lower or remains almost constant at around 70 to 90 km and 120 km depth/distance. This indicates presence of more attenuative material at those depth levels or distances compared to their immediate surroundings. It is proposed that this variation indicates presence of fluid filled fractures and/or partial melts at some depths/distance from the area of study. The Qc values are higher than those obtained for the Gulf of Suez and Al Dabbab region of Egypt at distances greater than 300 km from the study area by other workers. The turbidity decreases with depth in the study area.

European VLBI Network imaging of 6.7 GHz methanol masers

NASA Astrophysics Data System (ADS)

Bartkiewicz, A.; Szymczak, M.; van Langevelde, H. J.

2016-03-01

Context. Methanol masers at 6.7 GHz are well known tracers of high-mass star-forming regions. However, their origin is still not clearly understood. Aims: We aimed to determine the morphology and velocity structure for a large sample of the maser emission with generally lower peak flux densities than those in previous surveys. Methods: Using the European VLBI Network (EVN) we imaged the remaining sources from a sample of sources that were selected from the unbiased survey using the Torun 32 m dish. In this paper we report the results for 17 targets. Together they form a database of a total of 63 source images with high sensitivity (3σrms = 15-30 mJy beam-1), milliarcsecond angular resolution (6-10 mas) and very good spectral resolution (0.09 km s-1 or 0.18 km s-1) for detailed studies. Results: We studied in detail the properties of the maser clouds and calculated the mean and median values of the projected size (17.4 ± 1.2 au and 5.5 au, respectively) as well as the FWHM of the line (0.373 ± 0.011 km s-1 and 0.315 km s-1 for the mean and median values, respectively), testing whether it was consistent with Gaussian profile. We also found maser clouds with velocity gradients (71%) that ranged from 0.005 km s-1 au-1 to 0.210 km s-1 au-1. We tested the kinematic models to explain the observed structures of the 6.7 GHz emission. There were targets where the morphology supported the scenario of a rotating and expanding disk or a bipolar outflow. Comparing the interferometric and single-dish spectra we found that, typically, 50-70% of the flux was missing. This phenomena is not strongly related to the distance of the source. Conclusions: The EVN imaging reveals that in the complete sample of 63 sources the ring-like morphology appeared in 17% of sources, arcs were seen in a further 8%, and the structures were complex in 46% cases. The ultra-compact (UC) H II regions coincide in position in the sky for 13% of the sources. They are related both to extremely high and low luminosity masers from the sample. The catalogue of the complete sample is available via http://paulo.astro.uni.torun.pl/~pw/mmcat/

Tailpipe, resuspended road dust, and brake-wear emission factors from on-road vehicles

NASA Astrophysics Data System (ADS)

Abu-Allaban, Mahmoud; Gillies, John A.; Gertler, Alan W.; Clayton, Russ; Proffitt, David

Intensive mass and chemical measurements were performed at roadside locations in Reno, Nevada, and Durham/Research Triangle Park), North Carolina to derive tailpipe, resuspended road dust, and brake-wear emission factors from in-use vehicles. Continuous particulate matter (PM) data were utilized to derive total emission factors while integrated PM data were used to attribute the calculated emission factors to different mechanisms using chemical mass balance receptor modeling and scanning electron microscopy techniques. Resuspended road dust and tailpipe emissions were found to be the dominant mechanisms that contribute significantly to the total PM 10 and PM 2.5 emission factors, respectively. Small contributions from brake-wear were observed at locations where strong braking occurs, but no tire-wear was seen at any sampling location. PM 10 emission rates from light-duty spark ignition (LDSI) vehicles ranged from 40 to 780 mg/km, 10 to 70 mg/km, and 0 to 80 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively. PM 10 emission rates from heavy-duty vehicles ranged from 230 to 7800 mg/km, 60 to 570 mg/km, and 0 to 610 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively. PM 2.5 emission rates from LDSI vehicles ranged from 2 to 25 mg/km, 10 to 50 mg/km, and 0 to 5 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively. PM 2.5 emission rates from heavy-duty vehicles ranged from 15 to 300 mg/km, 60 to 480 mg/km, and 0 to 15 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively.

Active uptake of substance P carboxy-terminal heptapeptide (5-11) into rat brain and rabbit spinal cord slices.

PubMed

Nakata, Y; Kusaka, Y; Yajima, H; Segawa, T

1981-12-01

We previously reported that nerve terminals and glial cells lack an active uptake system capable of terminating transmitter action of substance P (SP). In the present study, we demonstrated the existence of an active uptake system for SP carboxy-terminal heptapeptide, (5-11)SP. When the slices from either rat brain or rabbit spinal cord were incubated with [3H](5-11)SP, the uptake of (5-11)SP into slices was observed. The uptake system has the properties of an active transport mechanism: it is dependent on temperature and sensitive to hypoosmotic treatment and is inhibited by ouabain and dinitrophenol (DNP). In the brain, (5-11)SP was accumulated by means of a high-affinity and a low-affinity uptake system. The Km and the Vmax values for the high-affinity system were 4.20 x 10(-8) M and 7.59 fmol/10 mg wet weight/min, respectively, whereas these values for the low-affinity system were 1.00 x 10(-6) M and 100 fmol/10 mg wet weight/min, respectively. In the spinal cord, there was only one uptake system, with a Km value of 2.16 x 10(-7) M and Vmax value of 26.2 fmol/10 mg wet weight/min. These results suggest that when SP is released from nerve terminals, it is hydrolysed into (5-11)SP before or after acting as a neurotransmitter, which is in turn accumulated into nerve terminals. Therefore, the uptake system may represent a possible mechanism for the inactivation of SP.

The Richter scale: its development and use for determining earthquake source parameters

USGS Publications Warehouse

Boore, D.M.

1989-01-01

The ML scale, introduced by Richter in 1935, is the antecedent of every magnitude scale in use today. The scale is defined such that a magnitude-3 earthquake recorded on a Wood-Anderson torsion seismometer at a distance of 100 km would write a record with a peak excursion of 1 mm. To be useful, some means are needed to correct recordings to the standard distance of 100 km. Richter provides a table of correction values, which he terms -log Ao, the latest of which is contained in his 1958 textbook. A new analysis of over 9000 readings from almost 1000 earthquakes in the southern California region was recently completed to redetermine the -log Ao values. Although some systematic differences were found between this analysis and Richter's values (such that using Richter's values would lead to underand overestimates of ML at distances less than 40 km and greater than 200 km, respectively), the accuracy of his values is remarkable in view of the small number of data used in their determination. Richter's corrections for the distance attenuation of the peak amplitudes on Wood-Anderson seismographs apply only to the southern California region, of course, and should not be used in other areas without first checking to make sure that they are applicable. Often in the past this has not been done, but recently a number of papers have been published determining the corrections for other areas. If there are significant differences in the attenuation within 100 km between regions, then the definition of the magnitude at 100 km could lead to difficulty in comparing the sizes of earthquakes in various parts of the world. To alleviate this, it is proposed that the scale be defined such that a magnitude 3 corresponds to 10 mm of motion at 17 km. This is consistent both with Richter's definition of ML at 100 km and with the newly determined distance corrections in the southern California region. Aside from the obvious (and original) use as a means of cataloguing earthquakes according to size, ML has been used in predictions of ground shaking as a function of distance and magnitude; it has also been used in estimating energy and seismic moment. There is a good correlation of peak ground velocity and the peak motion on a Wood-Anderson instrument at the same location, as well as an observationally defined (and theoretically predicted) nonlinear relation between ML and seismic moment. An important byproduct of the establishment of the ML scale is the continuous operation of the network of Wood-Anderson seismographs on which the scale is based. The records from these instruments can be used to make relative comparisons of amplitudes and waveforms of recent and historic earthquakes; furthermore, because of the moderate gain, the instruments can write onscale records from great earthquakes at teleseismic distances and thus can provide important information about the energy radiated from such earthquakes at frequencies where many instruments have saturated. ?? 1989.

Mg Isotope Evolution During Water-Rock Interaction in a Carbonate Aquifer

NASA Astrophysics Data System (ADS)

Zhang, Z.; Jacobson, A. D.; Lundstrom, C. C.; Huang, F.

2008-12-01

To better understand how Mg isotopes behave during weathering and aqueous transport, we used a Nu Plasma MC-ICP-MS to measure δ26Mg values (relative to DSM-3) in water samples along a 236 km flow path in the Madison aquifer of South Dakota, a confined carbonate aquifer recharging in the igneous Black Hills. We also analyzed local granite and dolomite samples to characterize the Mg isotope composition of source rocks constituting the recharge zone and aquifer, respectively. Repeated analyses of Mg standard solutions yielded external precisions (2σ) better than 0.1 permil for δ26Mg(CAM-1, - 2.584±0.071, n=13; UIMg-1, -2.217±0.087, n=9.). The Madison aquifer provides a unique opportunity to quantify Mg isotope effects during water-rock interaction because (1) fluids and rock have chemically equilibrated over a much longer timescale (up to ~15 kyr) than can be simulated in laboratory experiments and (2) previous studies have determined the rates and mass-balances of de- dolomitization and other geochemical reactions controlling solute evolution along the flow path. Reactions important for changing the concentration and isotope composition of Mg include dolomite dissolution, Mg-for- Na ion exchange, calcite precipitation, and isotope exchange. δ26Mg values within the recharge region (0-17 km along flow path) vary between -1.08 and -1.63 permil, and then remain essentially constant at -1.408±0.010 permil(1σ, 5 samples) from 17 to 189 km. A final sample at 236 km shows an increase to -1.09 permil. Either mixing between different recharge waters or rapid isotope exchange between infiltrating waters and dolomite could control δ26Mg variability between 0 and 17 km. Likewise, reactive transport modeling suggests that preferential uptake of 24Mg during Mg-for-Na ion exchange might cause an increase in δ26Mg between 189 and 236 km. However, unchanging δ26Mg values observed throughout most of the aquifer clearly demonstrate that Mg isotopes are not fractionated during reactive transport. This suggests that Mg isotopes can conservatively trace weathering inputs and groundwater flow in dolomite-rich aquifers.

Seismic b-value anomalies prior to the 3rd January 2016, Mw = 6.7 Manipur earthquake of northeast India

NASA Astrophysics Data System (ADS)

Borgohain, Jayanta Madhab; Borah, Kajaljyoti; Biswas, Rajib; Bora, Dipok K.

2018-04-01

Spatial variation of seismic b-value is estimated in the Indo-Myanmar subduction zone of northeast (NE) India using the homogeneous part of earthquake catalogue (1996-2015), recorded by International Seismological Center (ISC), consisting of 895 events of magnitude MW ≥ 3.9. The study region is divided into 1° × 1° square grids and b-values are estimated at each grid by maximum likelihood method. In this study, the b-value varies from 0.75 to 1.54 in the region. Significant variation of low b-value in the respective location may indicate high stress accumulation in that region. Spatial variation reveals intermediate b-value anomalies around the epicenter of the Mw = 6.7 Manipur earthquake which occurred on 3rd January at 23:05 UTC (4 January 2016 at 04:35 IST). The variations of b-values are also estimated with respect to depth. The low b-value associated with the depth range ∼15-55 km, which may imply crustal homogeneity and high stress accumulation in the crust. Since, NE India lies in the seismic zone V of the country; this study can be helpful to understand seismotectonics in the region.

Comparison of biochemical properties of liver arginase from streptozocin-induced diabetic and control mice.

PubMed

Spolarics, Z; Bond, J S

1989-11-01

Arginase activity is elevated in livers of diabetic animals compared to controls and there is evidence that this is due in part to increased specific activity (activity/mg arginase protein). To investigate the molecular basis of this increased activity, the physicochemical and kinetic properties of hepatic arginase from diabetic and control mice were compared. Two types of arginase subunits with molecular weights of 35,000 and 38,000 were found in both the diabetic and control animals and the subunits in these animals had similar, multiple ionic forms. Kinetic parameters of purified preparations of arginase for arginine (apparent Km and Vmax values) and the thermal stability of these preparations from diabetics and controls were also similar. Furthermore, no difference was found in the distribution of arginase activity among different subcellular liver fractions. Separation of basic and acidic oligomeric forms of arginase by fast-protein liquid chromatography resulted in a slightly different distribution of activity among the forms in the normal and diabetic group. The apparent Km values for Mn2+ of the basic form of the enzyme were 25 and 33 microM for the enzyme from normal and diabetic animals, respectively; for acidic forms, for which two apparent Km values were measured, the values were 8 and 197 microM for arginase from controls and 35 and 537 microM from diabetics. These results indicate that in diabetes, while no marked changes in the physicochemical characteristics of arginase are obvious, some changes are found in the interaction of arginase with its cofactor Mn.

Detection of Acoustic/Infrasonic/Seismic Waves Generated by Hypersonic Re-Entry of the HAYABUSA Capsule and Fragmented Parts of the Spacecraft

NASA Astrophysics Data System (ADS)

Yamamoto, Masa-Yuki; Ishihara, Yoshiaki; Hiramatsu, Yoshihiro; Kitamura, Kazuki; Ueda, Masayoshi; Shiba, Yasuo; Furumoto, Muneyoshi; Fujita, Kazuhisa

2011-10-01

Acoustic/infrasonic/seismic waves were observed during the re-entry of the Japanese asteroid explorer ``HAYABUSA'' at 6 ground sites in Woomera, Australia, on 2010 June 13. Overpressure values of infrasound waves were detected at 3 ground sites in a range from 1.3 Pa, 1.0 Pa, and 0.7 Pa with each distance of 36.9 km, 54.9 km, and 67.8 km, respectively, apart from the SRC trajectory. Seismic waveforms through air-to-ground coupling processes were also detected at 6 sites, showing a one-to-one correspondence to infrasound waves at all simultaneous observation sites. Audible sound up to 1 kHz was recorded at one site with a distance of 67.8 km. The mother spacecraft was fragmented from 75 km down to 38 km with a few explosive enhancements of emissions. A persistent train of HAYABUSA re-entry was confirmed at an altitude range of between 92 km down to 82 km for about 3 minutes. Light curves of 136 fragmented parts of the spacecraft were analyzed in detail based on video observations taken at multiple ground sites, being classified into three types of fragmentations, i.e., melting, explosive, and re-fragmented types. In a comparison between infrasonic waves and video-image analyses, regarding the generation of sonic-boom type shock waves by hypersonically moving artificial meteors, both the sample return capsule and fragmented parts of the mother spacecraft, at an altitude of 40 ± 1 km were confirmed with a one-to-one correspondence with each other.

Ultrasonic P- and S-Wave Attenuation and Petrophysical Properties of Deccan Flood Basalts, India, as Revealed by Borehole Studies

NASA Astrophysics Data System (ADS)

Vedanti, Nimisha; Malkoti, Ajay; Pandey, O. P.; Shrivastava, J. P.

2018-03-01

Petrophysical properties and ultrasonic P- and S-wave attenuation measurements on 35 Deccan basalt core specimens, recovered from Killari borehole site in western India, provide unique reference data-sets for a lesser studied Deccan Volcanic Province. These samples represent 338-m-thick basaltic column, consisting four lava flows each of Ambenali and Poladpur Formations, belonging to Wai Subgroup of the Deccan volcanic sequence. These basalt samples are found to be iron-rich (average FeOT: 13.4 wt%), but relatively poor in silica content (average SiO2: 47.8 wt%). The saturated massive basalt cores are characterized by a mean density of 2.91 g/cm3 (range 2.80-3.01 g/cm3) and mean P- and S-wave velocities of 5.89 km/s (range 5.01-6.50 km/s) and 3.43 km/s (range 2.84-3.69 km/s), respectively. In comparison, saturated vesicular basalt cores show a wide range in density (2.40-2.79 g/cm3) as well as P-wave (3.28-4.78 km/s) and S-wave (1.70-2.95 km/s) velocities. Based on the present study, the Deccan volcanic sequence can be assigned a weighted mean density of 2.74 g/cm3 and a low V p and V s of 5.00 and 3.00 km/s, respectively. Such low velocities in Deccan basalts can be attributed mainly to the presence of fine-grained glassy material, high iron contents, and hydrothermally altered secondary mineral products, besides higher porosity in vesicular samples. The measured Q values in saturated massive basalt cores vary enormously (Q p: 33-1960 and Q s: 35-506), while saturated vesicular basalt samples exhibit somewhat lesser variation in Q p (6-46) as well as Q s (5-49). In general, high-porosity rocks exhibit high attenuation, but we observed the high value of attenuation in some of the massive basalt core samples also. In such cases, energy loss is mainly due to the presence of fine-grained glassy material as well as secondary alteration products like chlorophaeite, that could contribute to intrinsic attenuation. Dominance of weekly bound secondary minerals might also be responsible for the generation of microcracks, which may generate squirt flow in saturated samples. Hence, we argue that the Deccan basalts attenuate seismic energy significantly, where its composition plays a major role.

Where does the plasmasphere begin? Revisit to topside ionospheric profiles in comparison with plasmaspheric TEC from Jason-1

NASA Astrophysics Data System (ADS)

Lee, Han-Byul; Kim, Yong Ha; Kim, Eunsol; Hong, Junseok; Kwak, Young-Sil

2016-10-01

Topside ionospheric profiles have been measured by Alouette 1 and ISIS 1/2 in the periods of 1962-1972 and 1972-1979, respectively. The profiles cover from the orbital altitude of 1000 km to the F2 peak and show large variations over local time, latitude, and seasons. We here analyze these variations in comparison with plasmaspheric total electron contents (pTECs) that were measured by Jason-1 satellite from the altitude of 1336 km to 20,200 km (GPS orbit). The scale heights of the profiles are generally smaller in the daytime than nighttime but show large day-to-day variations, implying that the ionospheric profiles at 1000 km are changing dynamically, rather than being in diffusive equilibrium. We also derived transition heights between O+ and H+, which show a clear minimum at dawn for low-latitude profiles due to decreasing O+ density at night. To compare with pTEC, we compute topside ionospheric total electron content (tiTEC) by integrating over 800-1336 km using the slope of the profiles. The tiTEC varies in a clear diurnal pattern from 0.3 to 1 and 3 total electron content unit (TECU, 1 TECU = 1016 el m-2) for low and high solar activity, respectively, whereas Jason-1 pTEC values are distributed over 2-6 TECU and 4-8 TECU for low and high solar activity, respectively, with no apparent diurnal modulation. Latitudinal variations of tiTEC show distinctive hemispheric asymmetry while that of Jason-1 pTEC is closely symmetric about the magnetic equator. The local time and latitudinal variations of tiTEC basically resemble those of the ionosphere but are characteristically different from those of Jason-1 pTEC. Based on the difference between tiTEC and pTEC variations, we propose that the region above 1300 km should be considered as the plasmasphere. Lower altitudes for the base of "plasmaspheric TEC," as used in some studies, would cause contamination of ionospheric influence.

Spatial variations in isostatic compensation mechanisms of the Ninetyeast Ridge and their tectonic significance

NASA Astrophysics Data System (ADS)

Sreejith, K. M.; Krishna, K. S.

2013-10-01

Ninetyeast Ridge (NER), one of the longest linear volcanic features on the Earth, offers an excellent opportunity of understanding the isostatic response to the interactions of mantle plume with the migrating mid-ocean ridge. Bathymetry, geoid, and gravity (shipborne and satellite) data along 72 closely spaced transects and 17 overlapping grids on the NER are analyzed and modeled to determine the effective elastic thickness (Te) beneath the entire ridge. The results of 2-D and 3-D flexural modeling of the NER show large spatial variations in Te values ranging from 4 to 35 km, suggesting that the ridge was compensated along its length by different isostatic mechanisms. The southern (south of 22°S latitude) and northern (north of 2°N latitude) parts of the NER have Te values of >10 and >23 km, respectively, revealing that the southern part was emplaced on a lithosphere of intermediate strength possibly on flank of the Indian plate, whereas the northern part was emplaced in an intraplate setting. In contrast, in the central part of the NER (between latitudes 22°S and 2°N), highly variable Te values (4-22 km) are estimated. The scattered Te values in the central NER suggest that this part may have evolved due to the occurrence of frequent ridge jumps caused by the interaction of Kerguelen hot spot with rapid northward migration of the Wharton spreading ridge. Residual Mantle Bouguer Anomaly (RMBA) map of the NER and adjacent basins reveals that the entire length of the NER is associated with a significant negative anomaly up to 200 mGal, indicating the presence of thickened crust or less dense mantle beneath the ridge. 3-D crustal thickness map of the NER, generated by inversion of the RMBA data, shows a thick crust ranging from 15 to 19 km. The present study clearly shows that NER possesses a highly segmented isostatic pattern with the occurrence of subcrustal underplating or subsurface loading.

Estimation of ground motion for Bhuj (26 January 2001; Mw 7.6 and for future earthquakes in India

USGS Publications Warehouse

Singh, S.K.; Bansal, B.K.; Bhattacharya, S.N.; Pacheco, J.F.; Dattatrayam, R.S.; Ordaz, M.; Suresh, G.; ,; Hough, S.E.

2003-01-01

Only five moderate and large earthquakes (Mw ???5.7) in India-three in the Indian shield region and two in the Himalayan arc region-have given rise to multiple strong ground-motion recordings. Near-source data are available for only two of these events. The Bhuj earthquake (Mw 7.6), which occurred in the shield region, gave rise to useful recordings at distances exceeding 550 km. Because of the scarcity of the data, we use the stochastic method to estimate ground motions. We assume that (1) S waves dominate at R < 100 km and Lg waves at R ??? 100 km, (2) Q = 508f0.48 is valid for the Indian shield as well as the Himalayan arc region, (3) the effective duration is given by fc-1 + 0.05R, where fc is the corner frequency, and R is the hypocentral distance in kilometer, and (4) the acceleration spectra are sharply cut off beyond 35 Hz. We use two finite-source stochastic models. One is an approximate model that reduces to the ??2-source model at distances greater that about twice the source dimension. This model has the advantage that the ground motion is controlled by the familiar stress parameter, ????. In the other finite-source model, which is more reliable for near-source ground-motion estimation, the high-frequency radiation is controlled by the strength factor, sfact, a quantity that is physically related to the maximum slip rate on the fault. We estimate ???? needed to fit the observed Amax and Vmax data of each earthquake (which are mostly in the far field). The corresponding sfact is obtained by requiring that the predicted curves from the two models match each other in the far field up to a distance of about 500 km. The results show: (1) The ???? that explains Amax data for shield events may be a function of depth, increasing from ???50 bars at 10 km to ???400 bars at 36 km. The corresponding sfact values range from 1.0-2.0. The ???? values for the two Himalayan arc events are 75 and 150 bars (sfact = 1.0 and 1.4). (2) The ???? required to explain Vmax data is, roughly, half the corresponding value for Amax, while the same sfact explains both sets of data. (3) The available far-field Amax and Vmax data for the Bhuj mainshock are well explained by ???? = 200 and 100 bars, respectively, or, equivalently, by sfact = 1.4. The predicted Amax and Vmax in the epicentral region of this earthquake are 0.80 to 0.95 g and 40 to 55 cm/sec, respectively.

Luffa aegyptiaca (Gourd) Fruit Juice as a Source of Peroxidase

PubMed Central

Yadav, R. S. S.; Yadav, K. S.; Yadav, H. S.

2011-01-01

Peroxidases have turned out to be potential biocatalyst for a variety of organic reactions. The research work reported in this communication was done with the objective of finding a convenient rich source of peroxidase which could be used as a biocatalyst for organic synthetic reactions. The studies made have shown that Luffa aegyptiaca (gourd) fruit juice contains peroxidase activity of the order of 180 enzyme unit/mL. The Km values of this peroxidase for the substrates guaiacol and hydrogen peroxide were 2.0 and 0.2 mM, respectively. The pH and temperature optima were 6.5 and 60°C, respectively. Like other peroxidases, it followed double displacement type mechanism. Sodium azide inhibited the enzyme competitively with Ki value of 3.35 mM. PMID:21804936

Luffa aegyptiaca (Gourd) Fruit Juice as a Source of Peroxidase.

PubMed

Yadav, R S S; Yadav, K S; Yadav, H S

2011-01-01

Peroxidases have turned out to be potential biocatalyst for a variety of organic reactions. The research work reported in this communication was done with the objective of finding a convenient rich source of peroxidase which could be used as a biocatalyst for organic synthetic reactions. The studies made have shown that Luffa aegyptiaca (gourd) fruit juice contains peroxidase activity of the order of 180 enzyme unit/mL. The K(m) values of this peroxidase for the substrates guaiacol and hydrogen peroxide were 2.0 and 0.2 mM, respectively. The pH and temperature optima were 6.5 and 60°C, respectively. Like other peroxidases, it followed double displacement type mechanism. Sodium azide inhibited the enzyme competitively with K(i) value of 3.35 mM.

Added value of high-resolution regional climate model over the Bohai Sea and Yellow Sea areas

NASA Astrophysics Data System (ADS)

Li, Delei; von Storch, Hans; Geyer, Beate

2016-04-01

Added value from dynamical downscaling has long been a crucial and debatable issue in regional climate studies. A 34 year (1979-2012) high-resolution (7 km grid) atmospheric hindcast over the Bohai Sea and the Yellow Sea (BYS) has been performed using COSMO-CLM (CCLM) forced by ERA-Interim reanalysis data (ERA-I). The accuracy of CCLM in surface wind reproduction and the added value of dynamical downscaling to ERA-I have been investigated through comparisons with the satellite data (including QuikSCAT Level2B 12.5 km version 3 (L2B12v3) swath data and MODIS images) and in situ observations, with adoption of quantitative metrics and qualitative assessment methods. The results revealed that CCLM has a reliable ability to reproduce the regional wind characteristics over the BYS areas. Over marine areas, added value to ERA-I has been detected in the coastal areas with complex coastlines and orography. CCLM was better able to represent light and moderate winds but has even more added value for strong winds relative to ERA-I. Over land areas, the high-resolution CCLM hindcast can add value to ERA-I in reproducing wind intensities and direction, wind probability distribution and extreme winds mainly at mountain areas. With respect to atmospheric processes, CCLM outperforms ERA-I in resolving detailed temporal and spatial structures for phenomena of a typhoon and of a coastal atmospheric front; CCLM generates some orography related phenomena such as a vortex street which is not captured by ERA-I. These added values demonstrate the utility of the 7-km-resolution CCLM for regional and local climate studies and applications. The simulation was constrained with adoption of spectral nudging method. The results may be different when simulations are considered, which are not constrained by spectral nudging.

b-value distribution in and around Mt. Tarumae, Japan

NASA Astrophysics Data System (ADS)

Chiba, K.

2017-12-01

Mt. Tarumae is an active volcano located in southeastern Shikotsu caldera, Hokkaido, Japan. Recently, crustal expansion occurred in 1999-2000 and 2013 near the summit of Mt. Tarumae, with a M5.6 earthquake recorded west of the summit on 8 July 2014. In this study, I determined hypocenter distributions and then performed b-value analysis for the period between 1 August 2014 and 12 August 2016 to improve our understanding of the magma system geometry beneath the summit of Mt. Tarumae. Hypocenters are mainly distributed in two regions: 3 - 5 km west of Mt. Tarumae, and beneath the volcano. I then determined b-value distributions. Regions with relatively high b-values ( 1.3) are located at depths of -0.5 to 2.0 km beneath the summit and at depths greater than 6.0 km in the northwestern part at about 1.5 - 3.0 km from the summit, while a region with relatively low b-values ( 0.6) is located at depths of 2.0 - 6.0 km beneath the summit. Compared the b-value distributions with other geophysical observations, it was found that the high b-value region from -0.5 to 2.0 km depth corresponds to regions of lower resistivity, positive self-potential anomaly, and an inflation source observed in 1999-2000. It is thus inferred that this region is generated by crustal heterogeneity, a decrease in effective normal stress, and change of a frictional property due to the development of faults and fissures, and the circulation of hydrothermal fluids. On the other hand, the inflation source observed in 2013 was located near the boundary between the low b-value region beneath the summit and the deeper high b-value region in the northwestern part at about 1.5 - 3.0 km from the summit. Studies of other volcanoes suggest that such a high-b-value region likely corresponds to a magma chamber. From the deeper high b-value region estimated in this study, I am able to point out that the magma chamber is located to depths greater than 6.0 km in the northwestern part at about 1.5 - 3.0 km from the summit. Thus, these findings contribute to our understanding of the magma plumbing system beneath the summit of Mt. Tarumae.

Stable isotope ratios of nonexchangeable hydrogen in organic matter of soils and plants along a 2100-km climosequence in Argentina: New insights into soil organic matter sources and transformations?

NASA Astrophysics Data System (ADS)

Ruppenthal, Marc; Oelmann, Yvonne; del Valle, Héctor Francisco; Wilcke, Wolfgang

2015-03-01

The quantitative contribution of shoot and root organic matter (OM) to the soil carbon (C) stock is still unknown, mainly because of methodological restrictions. The novel measurement of the nonexchangeable hydrogen (H) stable isotope ratio (δ2Hn) in bulk OM provides new opportunities to investigate the sources of soil C and its climate-dependent transformations. Our objectives were to test whether (I) there are systematic differences between δ2Hn values of aboveground and belowground plant OM and (II) δ2Hn values of litter and soil OM relate to climate and plant OM source δ2Hn signals. We determined δ2Hn values of bulk shoot, root, litter and demineralized soil OM from 20 sampling sites along a 2100-km climosequence from the Argentinean Pampas to the Patagonian steppe. The δ2Hn values of shoot and litter OM correlated closely with the aridity index (r = -0.83, p < 0.001 and r = -0.78, p < 0.001, respectively) because of H isotope fractionation during aridity-controlled transpiration in shoots. In contrast, δ2Hn values of root and soil OM showed a close correlation with modeled mean annual δ2H values of local precipitation (r = 0.91, p < 0.001 and r = 0.97, p < 0.001, respectively, root mean square error of 8.2‰ and 7.2‰, respectively) and thus mean annual temperature (r = 0.80, p < 0.001 and r = 0.88, p < 0.001, respectively). δ2Hn values of shoot and root OM differed markedly (no linear correlation) most likely because of biosynthetic exchange of C-bound H with ambient water in the roots. δ2Hn values of root and demineralized soil OM, however, were closely correlated (r = 0.91, p < 0.001) with a constant offset irrespective of climatic conditions, suggesting that root OM was a more important source of soil OM than shoot OM. A possible contribution of shoot OM to soil OM could only be explained if shoot OM underwent biosynthetic exchange of C-bound H with ambient water in soil during microbial and fungal decomposition. This mechanism is known for substrates processed through the microbial and fungal glycolysis-gluconeogenesis metabolic pathways. Our modeling suggested that the δ2Hn signature of soil OM is best explained under the assumption that root OM is the predominant source of soil OM, rather than shoot and litter OM.

Baseline climatology of extremely high vertical wind shears' values over Europe based on ERA-Interim reanalysis

NASA Astrophysics Data System (ADS)

Palarz, Angelika; Celiński-Mysław, Daniel

2017-04-01

The dominant role in the development of deep convection is played by kinematic and thermodynamic conditions, as well as atmospheric circulation, land cover and local relief. Severe thunderstorms are considerably more likely to form in environments with large values of convective available potential energy (CAPE) and significant magnitude of vertical wind shears (VWSs). According to the most recent research, the tropospheric wind shears have an important influence on intensity, longevity and organisation of the primary convective systems - bow echoes, squall lines and supercell thunderstorms. This study, in turn, examines the role of wind structure in controlling the spatial and temporal variability of VWSs over Europe. Considering the importance of the kinematic conditions for the convective systems formation, research is limited exclusively to 0-1 km, 0-3 km and 0-6 km wind shears. In order to compute the VWS' values, the data derived from ERA-Interim reanalysis for the period 1981-2015 was applied. It consisted of U and V wind components with 12-hourly sampling and horizontal resolution of 0.75×0.75°. The VWS' values were calculated as wind difference between two levels - this entails that the hodograph's shape was not considered (e.g. Clark 2013, Pucik et. al 2015). We have analysed both VWS' mean values (MN) and frequency of VWSs exceeding assumed thresholds (FQ). Taking into account previous studies (e.g. Rasmussen & Blanchard 1998, Schneider et al. 2006, Schaumann & Przybylinski 2012), the thresholds for extremely high values of vertical wind shears were set at 10 m/s for 0-1 km shear, 15 m/s for 0-3 km shear and 18 m/s for 0-6 km shear. Both MN and FQ values were characterised by strong temporal variability, as well as significant spatial differentiation over the research area. A clear diurnal cycle was identified in the case of 0-1 km shear, while seasonal variability was typical for 0-3 km and 0-6 km shears. Regardless of the season, 0-1 km shear reached higher MN and FQ values at 00 UTC than at 12 UTC. Moreover, its spatial distribution showed distinct differences linked to the underlying surface type. Surface energy budget seems to be an important factor contributing to the diurnal and spatial variability of VWSs - it generates the formation of local air circulation leading to modification of the wind direction and speed in the boundary layer. For 0-3 km and 0-6 km shears, a noticeable spatial differentiation between land and sea areas was not recognised. The significantly higher MN and FQ values over the land were found exclusively in the case of 0-3 km shear during the winter, particularly over the Mediterranean region. In the middle troposphere, the VWS' fluctuations (0-3 and 0-6 km shears) are primarily determined by the seasonal changes in atmospheric circulation patterns over the research area.

Crustal and uppermost mantle S-wave velocity below the East European Craton in northern Poland from the inversion of ambient-noise records

NASA Astrophysics Data System (ADS)

Lepore, Simone; Polkowski, Marcin; Grad, Marek

2018-02-01

The P-wave velocities (V p) within the East European Craton in Poland are well known through several seismic experiments which permitted to build a high-resolution 3D model down to 60 km depth. However, these seismic data do not provide sufficient information about the S-wave velocities (V s). For this reason, this paper presents the values of lithospheric V s and P-wave-to-S-wave velocity ratios (V p/V s) calculated from the ambient noise recorded during 2014 at "13 BB star" seismic array (13 stations, 78 midpoints) located in northern Poland. The 3D V p model in the area of the array consists of six sedimentary layers having total thickness within 3-7 km and V p in the range 1.85.3 km/s, a three-layer crystalline crust of total thickness 40 km and V p within 6.15-7.15 km/s, and the uppermost mantle, where V p is about 8.25 km/s. The V s and V p/V s values are calculated by the inversion of the surface-wave dispersion curves extracted from the noise cross correlation between all the station pairs. Due to the strong velocity differences among the layers, several modes are recognized in the 0.021 Hz frequency band: therefore, multimodal Monte Carlo inversions are applied. The calculated V s and V p/V s values in the sedimentary cover range within 0.992.66 km/s and 1.751.97 as expected. In the upper crust, the V s value (3.48 ± 0.10 km/s) is very low compared to the starting value of 3.75 ± 0.10 km/s. Consequently, the V p/V s value is very large (1.81 ± 0.03). To explain that the calculated values are compared with the ones for other old cratonic areas.

Carbonate clumped-isotope constraints on the burial and exhumation history of the Colorado Plateau

NASA Astrophysics Data System (ADS)

Ryb, U.; Lloyd, M. K.; Eiler, J. M.

2016-12-01

Reconstruction of the thermal history of rocks is key to study the geodynamic evolution of sedimentary basins. Carbonate clumped-isotope measurements of minerals formed or re-equilibrated at elevated temperatures can constrain thermal histories of rocks. Experimental constraints on solid state isotopic reordering in carbonates let us translate clumped-isotope measurements into quantitative statements about the thermal history, and thus burial and exhumation. We use this approach to constrain peak burial temperatures of Paleozoic rocks across the Colorado Plateau, sampled carbonate rocks from the southwestern Plateau margin and from borehole cores in the Plateau interior. We sub-sampled specific fabrics (fossils, cements, etc.), determined their calcite and dolomite proportions using XRD, and analyzed clumped-isotope compositions (reported as apparent temperatures using Stolper and Eiler's (2015) calibration) for pure calcite or dolomite samples (>97 wt.%). At the Plateau margin, calcite and dolomite apparent temperatures are 49-79°C and 67-97°C, respectively. The maximum apparent temperature constrains the minimum peak burial temperature. The distribution of calcite apparent temperatures independently constrains the maximum burial temperature as follows: If the "coldest" sample had an initial apparent temperature of 20°C, then its observed value can be explained by isotopic reordering to a peak temperature of 105-120°C. We therefore hypothesize peak temperature at the base of the Paleozoic was 97-120°C. At the Plateau interior, apparent temperatures of Mississippian calcite samples are depth-dependent: Samples cored from <2km depth have apparent temperatures of 54-68°C; similar samples from 3km depth have apparent temperatures of 105-165°C and a smaller variability between sub-samples, interpreted to result from isotopic reordering at >150°C. Assuming a surface temperature of 20°C and a thermal gradient of 25°C km-1, we calculate total overburden (above the Mississippian) and exhumation of 2.7-3.7 km and 1.8-2.8 km, respectively, at the Plateau margin; and total overburden and exhumation of 5.8-6.6 km, and 3-3.8 km, respectively, at the Plateau interior. Our findings are consistent with peak burial estimates based on thermochronometry and other proxies.

Impact of Cumulus Cloud Spacing on Landsat Atmospheric Correction and Aerosol Retrieval

NASA Technical Reports Server (NTRS)

Wen, Guoyong; Cahalan, Robert F.; Tsay, Si-Chee; Oreopoulos, Lazaros

2001-01-01

A Landsat-7 ETM+ image acquired over the Southern Great Plains DoE/ARM site during the ARESE II experiment is used to study the effect of clouds on reflected radiation in clear patches of a cumulus cloud field. The result shows that the apparent path radiance in the clear patches is enhanced by nearby clouds in both band 1 (blue) and band 3 (red) of ETM+. More importantly, the magnitude of the enhancement depends on the mean cloud-free distance in the clear patches. For cloud-free distance less than 0.5 km, the enhancement of apparent path radiance is more than 0.025 and 0.015 (reflectance units) in band 1 and band 3 respectively, which corresponds to an enhancement of apparent aerosol optical thickness of approximately 0.25 and approximately 0.15. Neglecting of the 3-D cloud effect would lead to underestimates of surface reflectance of approximately 0.025 and approximately 0.015 in the blue and red band respectively, if the true aerosol optical thickness is 0.2 and the surface reflectance is 0.05. The enhancement decreases exponentially with mean cloud-free distance, reaching asymptotic values of 0.09 for band 1 and 0.027 for band 3 at a mean cloud-free distance about 2 km. The asymptotic values are slightly larger than the mean path radiances retrieved from a completely clear region -- 0.086 and 0.024 for the blue and red band respectively.

Evaluating sourcing and fluvial integration of plant wax biomarkers from the Peruvian Andes to Amazonian lowlands

NASA Astrophysics Data System (ADS)

Wu, M. S.; Feakins, S. J.; Ponton, C.; West, A. J.; Galy, V.

2017-12-01

The carbon and hydrogen isotopic compositions (respectively δ13C and δD) of plant wax biomarkers have been widely used to reconstruct past climate and environment. To understand how leaf waxes are sourced within a river catchment, and how their isotopic signature is transferred from source to sink, we study δ13C and δD of C29 n-alkanes and C30 n-alkanoic acids in the Madre de Dios River catchment along the eastern flank of the Peruvian Andes. We sampled soils across a 3.5km elevation transect and find gradients in δ13Cwax (ca. +1.5‰/km) and δDwax (ca. -10 ‰/km) similar to gradients in tree canopy leaves (Feakins et al., 2016 GCA; Wu et al., 2017 GCA). We also collected river suspended sediment samples along the Madre de Dios River and its tributaries, which together drain an area of 75,400 km2 and 6 km of elevation. We utilize soil data and a digital elevation model to construct isoscapes, delineate catchments for each river sampling location, predict river values assuming spatial uniform integration, and compare our predictions with observed values. Although both compounds generally follow isotopic gradients defined by catchment elevations, the dual isotope and compound-class comparison reveals additional processes. For C30 n-alkanoic acid we find an up to 1km lower-than-expected catchment signal, indicating degradation of upland contributions in transit and replacement with lowland inputs. In contrast, mountain-front river locations are susceptible to upland-biases (up to 1km higher sourcing) in C29 n-alkane sourcing, likely due to enhanced erosion and higher leaf wax stock in Andean soil compared to the lowland, and greater persistence of n-alkanes than n-alkanoic acids. For both compounds, the bias is eliminated with several hundred km of river transit across the floodplain. In one location, we identify significant petrogenic contamination of n-alkanes but not n-alkanoic acids. These results indicate the power in combining dual compound classes and dual isotopes to analyze source-to-sink processes and to evaluate sourcing of river exported plant wax biomarkers.

Carrier-mediated uptake of nobiletin, a citrus polymethoxyflavonoid, in human intestinal Caco-2 cells.

PubMed

Kimura, Osamu; Ohta, Chiho; Koga, Nobuyuki; Haraguchi, Koichi; Kato, Yoshihisa; Endo, Tetsuya

2014-07-01

The mechanism of intestinal absorption of nobiletin (NBL) was investigated using Caco-2 cells. The uptake of NBL from the apical membranes of Caco-2 cells was rapid and temperature-dependent and the presence of metabolic inhibitors, NaN3 and carbonylcyanide p-trifluoromethoxyphenylhydrazone, did not cause a decrease in NBL uptake. The relationship between the initial uptake of NBL and its concentration was saturable, suggesting the involvement of a carrier-mediated process. The Km and uptake clearance (Vmax/Km) values for NBL were 50.6 and 168.1μl/mg protein/min, respectively. This clearance value was about 9-fold greater than that of the non-saturable uptake clearance (Kd: 18.5μl/mg protein/min). The presence of structurally similar compounds, such as quercetin and luteolin, competitively inhibited NBL uptake. These results suggest that uptake of NBL from the apical membranes of Caco-2 cells is mainly mediated by an energy-independent facilitated diffusion process. Copyright © 2013 Elsevier Ltd. All rights reserved.

Precipitable Water Vapour at the Canarian Observatories (Teide and Roque de los Muchachos) from routine GPS

NASA Astrophysics Data System (ADS)

Castro-Almazán, Julio A.; Muñoz-Tuñón, Casiana; García-Lorenzo, Begoña.; Pérez-Jordán, Gabriel; Varela, Antonia M.; Romero, Ignacio

2016-07-01

We are presenting two years (2012 and 2013) of preliminary statistical results of calibrated PWV values from the GPS geodesic antennas (LPAL and IZAN) at Teide and Roque de los Muchachos Observatories (OT and ORM), Canary Islands. To calibrate the PWV from both GPS antennas we have selected a set of simultaneous high vertical resolution radio-sounding profiles from the closest operational balloon station, Güímar (GUI-WMO 60018; ≍15 km distant from OT and ≍150 km from ORM). The calibrations showed a correlation of 0.994 and 0.970 for OT and ORM, respectively, with rmse of 0.44 and 0.70 mm. The calibrated PWV series brought median values of 3.5 mm at OT and 4.0 mm at ORM. The difference is explained by the 200 m of difference in height of the antennas (LPAL antenna is below the telescopes altitude). Twenty five percent of the time, PWV is less than 1.7 mm.

Propagation of Stationary Planetary Waves in the Upper Atmosphere under Different Solar Activity

NASA Astrophysics Data System (ADS)

Koval, A. V.; Gavrilov, N. M.; Pogoreltsev, A. I.; Shevchuk, N. O.

2018-03-01

Numerical modeling of changes in the zonal circulation and amplitudes of stationary planetary waves are performed with an accounting for the impact of solar activity variations on the thermosphere. A thermospheric version of the Middle/Upper Atmosphere Model (MUAM) is used to calculate the circulation in the middle and upper atmosphere at altitudes up to 300 km from the Earth's surface. Different values of the solar radio emission flux in the thermosphere are specified at a wavelength of 10.7 cm to take into account the solar activity variations. The ionospheric conductivities and their variations in latitude, longitude, and time are taken into account. The calculations are done for the January-February period and the conditions of low, medium, and high solar activity. It was shown that, during high-activity periods, the zonal wind velocities increases at altitudes exceeding 150 km and decreases in the lower layers. The amplitudes of planetary waves at high solar activity with respect to the altitude above 120 km or below 100 km, respectively, are smaller or larger than those at low activity. These differences correspond to the calculated changes in the refractive index of the atmosphere for stationary planetary waves and the Eliassen-Palm flux. Changes in the conditions for the propagation and reflection of stationary planetary waves in the thermosphere may influence the variations in their amplitudes and the atmospheric circulation, including the lower altitudes of the middle atmosphere.

Electrochemical quantification of the antioxidant capacity of medicinal plants using biosensors.

PubMed

Rodríguez-Sevilla, Erika; Ramírez-Silva, María-Teresa; Romero-Romo, Mario; Ibarra-Escutia, Pedro; Palomar-Pardavé, Manuel

2014-08-08

The working area of a screen-printed electrode, SPE, was modified with the enzyme tyrosinase (Tyr) using different immobilization methods, namely entrapment with water-soluble polyvinyl alcohol (PVA), cross-linking using glutaraldehyde (GA), and cross-linking using GA and human serum albumin (HSA); the resulting electrodes were termed SPE/Tyr/PVA, SPE/Tyr/GA and SPE/Tyr/HSA/GA, respectively. These biosensors were characterized by means of amperometry and EIS techniques. From amperometric evaluations, the apparent Michaelis-Menten constant, Km', of each biosensor was evaluated while the respective charge transfer resistance, Rct, was assessed from impedance measurements. It was found that the SPE/Tyr/GA had the smallest Km' (57 ± 7) µM and Rct values. This electrode also displayed both the lowest detection and quantification limits for catechol quantification. Using the SPE/Tyr/GA, the Trolox Equivalent Antioxidant Capacity (TEAC) was determined from infusions prepared with "mirto" (Salvia microphylla), "hHierba dulce" (Lippia dulcis) and "salve real" (Lippia alba), medicinal plants commonly used in Mexico.

The diameter of Pallas from its occultation of SAO 85009

NASA Technical Reports Server (NTRS)

Wasserman, L. H.; Millis, R. L.; Franz, O. G.; Bowell, E.; Giclas, H. L.; Martin, L. J.; Elliot, J. L.; Dunham, E.; Mink, D.; White, N. M.

1979-01-01

The May 29, 1978, occultation of SAO 85009 by Pallas was observed photoelectrically at seven widely spaced sites. The observations are well represented by an elliptical apparent limb profile having semimajor and semiminor axes of 279.5 + or - 2.9 and 262.7 + or - 4.5 km, respectively. Combining these results with published information on the light curve and rotational pole position, Pallas's mean diameter is found to be 538 + or - 12 km, which yields a mean density for Pallas of 2.8 + or - 0.5 g/cu cm and a visual geometric albedo of 0.103 + or - 0.005. The diameter of Pallas as determined from this occultation is significantly smaller than the values derived by radiometric, polarimetric, and double-image techniques.

A holistic water balance of Austria - how does the quantitative proportion of urban water requirements relate to other users?

PubMed

Vanham, D

2012-01-01

Traditional water use statistics only include the blue water withdrawal/consumption of municipalities, industry and irrigated agriculture. When, however, green water use of the agricultural sector is included as well as the virtual water use/water footprint (WF), water use quantity statistics become very different. In common water use statistics, Austria withdraws in total about 2.5 km(3) per year, only 3% of available resources (total discharge 81.4 km(3) = surface and ground water). The total water consumption (0.5 km(3)) is less than 1% of available resources. Urban (municipal) water requirements account for 27% of total withdrawal or 33% of consumption. When agricultural green water use (cropland) is included in statistics, the fraction of municipal water requirements diminishes to 7.6% of total withdrawal and 2.5% of total consumption. If the evapotranspiration of grassland and alpine meadows is also included in agricultural green water use, this fraction decreases to 3.2% and 0.9% respectively. When the WF is assessed as base value for water use in Austria, the municipal water use represents 5.8% of this value. In this globalized world, these traditional water use statistics are no longer recommendable. Only a holistic water balance approach really represents water use statistics.

Stable isotope and petrologic evidence for open-system degassing during the climactic and pre-climactic eruptions of Mt. Mazama, Crater Lake, Oregon

USGS Publications Warehouse

Mandeville, C.W.; Webster, J.D.; Tappen, C.; Taylor, B.E.; Timbal, A.; Sasaki, A.; Hauri, E.; Bacon, C.R.

2009-01-01

Evaluation of the extent of volatile element recycling in convergent margin volcanism requires delineating likely source(s) of magmatic volatiles through stable isotopic characterization of sulfur, hydrogen and oxygen in erupted tephra with appropriate assessment of modification by degassing. The climactic eruption of Mt. Mazama ejected approximately 50 km3 of rhyodacitic magma into the atmosphere and resulted in formation of a 10-km diameter caldera now occupied by Crater Lake, Oregon (lat. 43??N, long. 122??W). Isotopic compositions of whole-rocks, matrix glasses and minerals from Mt. Mazama climactic, pre-climactic and postcaldera tephra were determined to identify the likely source(s) of H2O and S. Integration of stable isotopic data with petrologic data from melt inclusions has allowed for estimation of pre-eruptive dissolved volatile concentrations and placed constraints on the extent, conditions and style of degassing. Sulfur isotope analyses of climactic rhyodacitic whole rocks yield ??34S values of 2.8-14.8??? with corresponding matrix glass values of 2.4-13.2???. ??34S tends to increase with stratigraphic height through climactic eruptive units, consistent with open-system degassing. Dissolved sulfur concentrations in melt inclusions (MIs) from pre-climactic and climactic rhyodacitic pumices varies from 80 to 330 ppm, with highest concentrations in inclusions with 4.8-5.2 wt% H2O (by FTIR). Up to 50% of the initial S may have been lost through pre-eruptive degassing at depths of 4-5 km. Ion microprobe analyses of pyrrhotite in climactic rhyodacitic tephra and andesitic scoria indicate a range in ??34S from -0.4??? to 5.8??? and from -0.1??? to 3.5???, respectively. Initial ??34S values of rhyodacitic and andesitic magmas were likely near the mantle value of 0???. Hydrogen isotope (??D) and total H2O analyses of rhyodacitic obsidian (and vitrophyre) from the climactic fall deposit yielded values ??f -103 to -53??? and 0.23-1.74 wt%, respectively. Values of ??D and wt% H2O of obsidian decrease towards the top of the fall deposit. Samples with depleted ??D, and mantle ??18O values, have elevated ??34S values consistent with open-system degassing. These results imply that more mantle-derived sulfur is degassed to the Earth's atmosphere/hydrosphere through convergent margin volcanism than previously attributed. Magmatic degassing can modify initial isotopic compositions of sulfur by >14??? (to ??34S values of 14??? or more here) and hydrogen isotopic compositions by 90??? (to ??D values of -127??? in this case). ?? 2009 Elsevier Ltd.

Projection of the change in future extremes over Japan using a cloud-resolving model: (2) Precipitation Extremes and the results of the NHM-1km experiments

NASA Astrophysics Data System (ADS)

Kanada, S.; Nakano, M.; Nakamura, M.; Hayashi, S.; Kato, T.; Kurihara, K.; Sasaki, H.; Uchiyama, T.; Aranami, K.; Honda, Y.; Kitoh, A.

2008-12-01

In order to study changes in the regional climate in the vicinity of Japan during the summer rainy season due to global warming, experiments by a semi-cloud resolving non-hydrostatic model with a horizontal resolution of 5km (NHM-5km) have been conducted from June to October by nesting within the results of the 10-year time-integrated experiments using a hydrostatic atmospheric general circulation model with a horizontal grid of 20 km (AGCM-20km: TL959L60) for the present and future up to the year 2100. A non-hydrostatic model developed by the Japan Meteorological Agency (JMA) (JMA-NHM; Saito et al. 2001, 2006) was adopted. Detailed descriptions of the NHM-5km are shown by the poster of Nakano et al. Our results show that rainy days over most of the Japanese Islands will decrease in June and July and increase in August and September in the future climate. Especially, remarkable increases in intense precipitations such as larger than 150 - 300 mm/day are projected from the present to future climate. The 90th percentiles of regional largest values among maximum daily precipitations (R-MDPs) grow 156 to 207 mm/day in the present and future climates, respectively. It is well-known that the horizontal distribution of precipitation, especially the heavy rainfall in the vicinity of Japan, much depends on the topography. Therefore, higher resolution experiments by a cloud-resolving model with a horizontal resolution of 1km (NHM-1km) are one-way nested within the results of NHM-5km. The basic frame and design of the NHM-1km is the same as those of the NHM-5km, but the topography is finer and no cumulus parameterization is used in the NHM-1km experiments. The NHM-1km, which treats the convection and cloud microphysics explicitly, can represent not only horizontal distributions of rainfall in detail but also the 3-dimensional structures of meso-beta-scale convective systems (MCSs). Because of the limitation of computation resources, only heavy rainfall events that rank in top 10 % of all rainfall events are selected for the NHM-1km experiments (Heavy rainfall events are defined by R-MDPs > 156 and 207 mm/day for the present and future climates, respectively, from the results of the NHM-5km). Tentative comparisons between the results of the NHM-1km and NHM-1km experiments reveal that the NHM-1km can re-produce more detailed and realistic horizontal distributions of rainfall in many cases. (This study is supported by the Ministry of Education, Culture, Sports, Science and Technology under the framework of the KAKUSHIN program. Numerical simulations are performed in the Earth Simulator)

Response of the mid-latitude D-region ionosphere to the total solar eclipse of 22 July 2009 studied using VLF signals in South Korean peninsula

NASA Astrophysics Data System (ADS)

Phanikumar, D. V.; Kwak, Y.-S.; Patra, A. K.; Maurya, A. K.; Singh, Rajesh; Park, S.-M.

2014-09-01

In this paper, we analyze VLF signals received at Busan to study the the D-region changes linked with the solar eclipse event of 22 July 2009 for very short (∼390 km) transmitter-receiver great circle path (TRGCP) during local noon time 00:36-03:13 UT (09:36-12:13 KST). The eclipse crossed south of Busan with a maximum obscuration of ∼84%. Observations clearly show a reduction of ∼6.2 dB in the VLF signal strength at the time of maximum solar obscuration (84% at 01:53 UT) as compared to those observed on the control days. Estimated values of change in Wait ionospheric parameters: reflection height (h‧) in km and inverse scale height parameter (β) in km-1 from Long Wave Propagation Capability (LWPC) model during the maximum eclipse phase as compared to unperturbed ionosphere are 7 km and 0.055 km-1, respectively. Moreover, the D-region electron density estimated from model computation shows 95% depletion in electron density at the height of ∼71 km. The reflection height is found to increase by ∼7 km in the D-region during the eclipse as compared to those on the control days, implying a depletion in the Lyman-α flux by a factor of ∼7. The present observations are discussed in the light of current understanding on the solar eclipse induced D-region dynamics.

Determination of ionospheric electron content from the Faraday rotation of geostationary satellite signals.

NASA Technical Reports Server (NTRS)

Titheridge, J. E.

1972-01-01

Observation that calculations of the integrated electron content up to the height of the satellite, using a wide range of model ionospheres (with a peak at 300 km) could be up to four times the value deduced from Faraday rotation measurements. However, using a fixed mean field height of 400 km, the observed Faraday rotation gives the electron content up to a height h sub F of 2000 km with an accuracy of plus or minus 3%. For observations at different magnetic and geographic latitudes, and geostationary satellites at different longitudes, the optimum value of h sub F varies by only plus or minus 200 km. Nighttime increases in the height of the ionosphere have little effect on h sub F, but increase the mean field height to about 470 km. Using a fixed value of 420 km, with h sub F = 2000 km, gives an accuracy of plus or minus 5% under most conditions.

Hα observations with DEFPOS

NASA Astrophysics Data System (ADS)

Sahan, M.

2011-02-01

A 7.5 cm, dual étalon Fabry-Pérot spectrometer called DEFPOS has been set up at Coudé focus of 150 cm RTT150 telescope at TUBITAK National Observatory (TUG, Antalya, Turkey) to investigate the physical properties of Diffuse Ionized Gas (DIG) in our Galaxy. The spectrometer, having a 4 arcmin circular field of view over a 200 km s-1 (4.4 Å) spectral window near Hα, has been used to observe H II regions and Planetary Nebulae (PNe) since May 2007 (Sahan et al. 2009). Early observations have been analyzed and physical and kinematic properties such as the intensity, the line width, and the LSR velocity are presented here. These values are compared with earlier results from different studies. In this study, I discuss some results obtained by DEFPOS, including two H II regions (Sh2-156, Sh2-157), and two PNe (NGC 1360, and NGC 6826). The Intensities, the radial velocities and the line widths of the Hα emission line vary from 101.4R to 149.97R (1 Rayleigh =106/4π photons cm-2 sr-1 s-1 = 2.41×10-7 erg cm-2 s-1 sr-1 at Hα), -41.19 km s-1 to +8.34 km s-1, and 39.55 km s-1 to 58.23 km s-1, respectively.

Active fire detection using a peat fire radiance model

NASA Astrophysics Data System (ADS)

Kushida, K.; Honma, T.; Kaku, K.; Fukuda, M.

2011-12-01

The fire fractional area and radiances at 4 and 11 μm of active fires in Indonesia were estimated using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images. Based on these fire information, a stochastic fire model was used for evaluating two fire detection algorithms of Moderate Resolution Imaging Spectroradiometer (MODIS). One is single-image stochastic fire detection, and the other is multitemporal stochastic fire detection (Kushida, 2010 - IEEE Geosci. Remote Sens. Lett.). The average fire fractional area per one 1 km2 ×1 km2 pixel was 1.7%; this value corresponds to 32% of that of Siberian and Mongolian boreal forest fires. The average radiances at 4 and 11 μm of active fires were 7.2 W/(m2.sr.μm) and 11.1 W/(m2.sr.μm); these values correspond to 47% and 91% of those of Siberian and Mongolian boreal forest fires, respectively. In order to get false alarms less than 20 points per 106 km2 area, for the Siberian and Mongolian boreal forest fires, omission errors (OE) of 50-60% and about 40% were expected for the detections by using the single and multitemporal images, respectively. For Indonesian peat fires, OE of 80-90% was expected for the detections by using the single images. For the peat-fire detections by using the multitemporal images, OE of about 40% was expected, provided that the background radiances were estimated from past multitemporal images with less than the standard deviation of 1K. The analyses indicated that it was difficult to obtain sufficient active-fire information of Indonesian peat fires from single MODIS images for the fire fighting, and that the use of the multitemporal images was important.

Assessing and mapping spatial associations among oral cancer mortality rates, concentrations of heavy metals in soil, and land use types based on multiple scale data.

PubMed

Lin, Wei-Chih; Lin, Yu-Pin; Wang, Yung-Chieh; Chang, Tsun-Kuo; Chiang, Li-Chi

2014-02-21

In this study, a deconvolution procedure was used to create a variogram of oral cancer (OC) rates. Based on the variogram, area-to-point (ATP) Poisson kriging and p-field simulation were used to downscale and simulate, respectively, the OC rate data for Taiwan from the district scale to a 1 km × 1 km grid scale. Local cluster analysis (LCA) of OC mortality rates was then performed to identify OC mortality rate hot spots based on the downscaled and the p-field-simulated OC mortality maps. The relationship between OC mortality and land use was studied by overlapping the maps of the downscaled OC mortality, the LCA results, and the land uses. One thousand simulations were performed to quantify local and spatial uncertainties in the LCA to identify OC mortality hot spots. The scatter plots and Spearman's rank correlation yielded the relationship between OC mortality and concentrations of the seven metals in the 1 km cell grid. The correlation analysis results for the 1 km scale revealed a weak correlation between OC mortality rate and concentrations of the seven studied heavy metals in soil. Accordingly, the heavy metal concentrations in soil are not major determinants of OC mortality rates at the 1 km scale at which soils were sampled. The LCA statistical results for local indicator of spatial association (LISA) revealed that the sites with high probability of high-high (high value surrounded by high values) OC mortality at the 1 km grid scale were clustered in southern, eastern, and mid-western Taiwan. The number of such sites was also significantly higher on agricultural land and in urban regions than on land with other uses. The proposed approach can be used to downscale and evaluate uncertainty in mortality data from a coarse scale to a fine scale at which useful additional information can be obtained for assessing and managing land use and risk.

Optical Maturity on the Walls of Lunar Craters

NASA Astrophysics Data System (ADS)

Sim, C. K.; Kim, S.; Lucey, P. G.; Garrick-Bethell, I.; Baek, G.; Choi, Y. J.

2016-12-01

Recent studies have found that the optical maturity (OMAT) and mean grain size of the lunar regolith have latitude dependences, probably because of the reduced flux of space-weathering agents at high latitudes. Here we extend our previous work (Jeong et al.) to the inner walls of lunar impact craters, dividing the wall into four quadrants. We consider the 1,872 craters whose diameter is between 5 km and 120 km in the Lunar Impact Crater Database 2015 from the LPI. We adopt the topography-corrected OMAT data from the Kaguya/MI observations. We find that at high latitudes, the equator-facing walls have generally smaller (more mature) OMAT values than the pole-facing walls. This is consistent with the global latitudinal dependence of the OMAT and values previously found. The overall mean value curve of [OMAT(E) - OMAT(W)] has a minimum and maximum near longitudes -60° and +60°, respectively. This is thought to be due to the shielding of solar wind particles during the Moon's passage through the Earth's magneto-tail. Because micrometeoroids are not affected by the magnetosphere passage, the longitudinal effect unambiguously discriminates between micrometeoroid and solar wind effects.

Neutrons from thunderstorms at low atmospheric altitudes and related doses at aircraft

NASA Astrophysics Data System (ADS)

Drozdov, A.; Grigoriev, A.

2013-02-01

We conduct a simulation of thunderstorm neutron flashes at the lowest atmospheric altitudes below 10 km. The neutron generation mechanism is based on the nowadays conventional idea of possibility for photonuclear reactions to proceed on the atmospheric components owing to TGF photons. Our modeling includes generation of neutrons from TGF and their further propagation with account of interaction with background nuclei. Using the calculation results we investigate the neutron flux properties with respect to problem of their registration, and predict the radiation environment caused by thunderstorm neutrons on altitudes of civil airflights. It is shown, that good conditions for the neutron flashes observation are provided from the 3 km altitude, and, possibly, the neutrons can be registered at ground level. We also found that thunderstorm-neutron-related effective dose can reach the value of 0.5 mSv in the region close to the TGF source if it is located at an altitude of 10 km.

Effect of Advection on Evaporative Fluxes and Vapor Isotopic Ratios: The Lake Size Effect

NASA Astrophysics Data System (ADS)

Feng, X.; Lauder, A. M.; Kopec, B. G.; Posmentier, E. S.

2015-12-01

It has been reported that advection of air from land can be identified hundreds of kilometers off shore. With advection, moisture builds up downwind, and the evaporative flux decreases and isotopic flux ratios increase with distance. If a lake is small relative to the equilibration distance, the fluxes of all water isotopologues averaged over the lake are different from those calculated using models without advection. The magnitude of the discrepancy depends on the lake size; we refer to this as the "lake size effect". In Kangerlussuaq, Greenland, we observed significant horizontal gradients in concentration, δD, and δ18O of vapor up to 5 km along the wind direction. Over a 0.5 km long lake, the observed average gradients were 1380 ppm/km for vapor content, 21‰/km for δD, 2.4‰/km for δ18O, and 5‰/km for d-excess. These gradients decreased with distance from the upwind shore. Over a stretch of another, much larger lake 4-5 km from the upwind shore, we observed gradients of 354 ppm/km, 1.5‰/km, 0.22‰/km and 0.3‰/km, for vapor concentration, δD, δ18O, and d-excess, respectively. These observations were modeled successfully using a two-dimensional (2-D, horizontal and vertical) steady state advection diffusion model. This model also computes evaporative fluxes. Using the model results, we assess the magnitude of the lake size effect and its impact on water balance calculations. Under the condition of our field observations and for lakes less than 500 m along the wind direction, the mean flux δ18O and δD were at least 2‰ lower than the corresponding values from a 1-D model (vertical only). If using biased isotopic flux values for water balance calculations, the lake size effect would lead to an underestimation of the lake I/E (input to evaporation) ratio. For example, if the lake effect is 1‰, the corresponding underestimation of the I/E ratio is about 10% if using δ18O, and less than 2% if using δD for the computation. This argues for advantageous use of δD over δ18O in water balance and paleoclimate studies when the lake size is small or changes significantly over time. Still greater accuracy in water balance assessment can be achieved by using the 2-D model to correct for the lake size effect under the environmental conditions at the location of interest.

A solvent-isotope-effect study of proton transfer during catalysis by Escherichia coli (lacZ) beta-galactosidase.

PubMed Central

Selwood, T; Sinnott, M L

1990-01-01

1. Michaelis-Menten parameters for the hydrolysis of 4-nitrophenyl beta-D-galactopyranoside and 3,4-dinitrophenyl beta-D-galactopyranoside Escherichia coli (lacZ) beta-galactosidase were measured as a function of pH or pD (pL) in both 1H2O and 2H2O. 2. For hydrolysis of 4-nitrophenyl beta-D-galactopyranoside by Mg2(+)-free enzyme, V is pL-independent below pL 9, but the V/Km-pL profile is sigmoid, the pK values shifting from 7.6 +/- 0.1 in 1H2O to 8.2 +/- 0.1 in 2H2O, and solvent kinetic isotope effects are negligible, in accord with the proposal [Sinnott, Withers & Viratelle (1978) Biochem. J. 175, 539-546] that glycone-aglycone fission without acid catalysis governs both V and V/Km. 3. V for hydrolysis of 4-nitrophenyl beta-D-galactopyranoside by Mg2(+)-enzyme varies sigmoidally with pL, the pK value shifting from 9.19 +/- 0.09 to 9.70 +/- 0.07; V/Km shows both a low-pL fall, probably due to competition between Mg2+ and protons [Tenu, Viratelle, Garnier & Yon (1971) Eur. J. Biochem. 20, 363-370], and a high-pL fall, governed by a pK that shifts from 8.33 +/- 0.08 to 8.83 +/- 0.08. There is a negligible solvent kinetic isotope effect on V/Km, but one of 1.7 on V, which a linear proton inventory shows to arise from one transferred proton. 4. The variation of V and V/Km with pL is sigmoid for hydrolysis of 3,4-dinitrophenyl beta-D-galactopyranoside by Mg2(+)-enzyme, with pK values showing small shifts, from 8.78 +/- 0.09 to 8.65 +/- 0.08 and from 8.7 +/- 0.1 to 8.9 +/- 0.1 respectively. There is no solvent isotope effect on V or V/Km for 3,4-dinitrophenyl beta-D-galactopyranoside, despite hydrolysis of the galactosyl-enzyme intermediate governing V. 5. Identification of the 'conformation change' in the hydrolysis of aryl galactosides proposed by Sinnott & Souchard [(1973) Biochem. J. 133, 89-98] with the protolysis of the magnesium phenoxide arising from the action of enzyme-bound Mg2+ as an electrophilic catalyst rationalizes these data and also resolves the conflict between the proposals and the 18O kinetic-isotope-effect data reported by Rosenberg & Kirsch [(1981) Biochemistry 20, 3189-3196]. It should be noted that the actual Km values were determined to higher precision than can be estimated from the Figures in this paper.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2114090

A solvent-isotope-effect study of proton transfer during catalysis by Escherichia coli (lacZ) beta-galactosidase.

PubMed

Selwood, T; Sinnott, M L

1990-06-01

1. Michaelis-Menten parameters for the hydrolysis of 4-nitrophenyl beta-D-galactopyranoside and 3,4-dinitrophenyl beta-D-galactopyranoside Escherichia coli (lacZ) beta-galactosidase were measured as a function of pH or pD (pL) in both 1H2O and 2H2O. 2. For hydrolysis of 4-nitrophenyl beta-D-galactopyranoside by Mg2(+)-free enzyme, V is pL-independent below pL 9, but the V/Km-pL profile is sigmoid, the pK values shifting from 7.6 +/- 0.1 in 1H2O to 8.2 +/- 0.1 in 2H2O, and solvent kinetic isotope effects are negligible, in accord with the proposal [Sinnott, Withers & Viratelle (1978) Biochem. J. 175, 539-546] that glycone-aglycone fission without acid catalysis governs both V and V/Km. 3. V for hydrolysis of 4-nitrophenyl beta-D-galactopyranoside by Mg2(+)-enzyme varies sigmoidally with pL, the pK value shifting from 9.19 +/- 0.09 to 9.70 +/- 0.07; V/Km shows both a low-pL fall, probably due to competition between Mg2+ and protons [Tenu, Viratelle, Garnier & Yon (1971) Eur. J. Biochem. 20, 363-370], and a high-pL fall, governed by a pK that shifts from 8.33 +/- 0.08 to 8.83 +/- 0.08. There is a negligible solvent kinetic isotope effect on V/Km, but one of 1.7 on V, which a linear proton inventory shows to arise from one transferred proton. 4. The variation of V and V/Km with pL is sigmoid for hydrolysis of 3,4-dinitrophenyl beta-D-galactopyranoside by Mg2(+)-enzyme, with pK values showing small shifts, from 8.78 +/- 0.09 to 8.65 +/- 0.08 and from 8.7 +/- 0.1 to 8.9 +/- 0.1 respectively. There is no solvent isotope effect on V or V/Km for 3,4-dinitrophenyl beta-D-galactopyranoside, despite hydrolysis of the galactosyl-enzyme intermediate governing V. 5. Identification of the 'conformation change' in the hydrolysis of aryl galactosides proposed by Sinnott & Souchard [(1973) Biochem. J. 133, 89-98] with the protolysis of the magnesium phenoxide arising from the action of enzyme-bound Mg2+ as an electrophilic catalyst rationalizes these data and also resolves the conflict between the proposals and the 18O kinetic-isotope-effect data reported by Rosenberg & Kirsch [(1981) Biochemistry 20, 3189-3196]. It should be noted that the actual Km values were determined to higher precision than can be estimated from the Figures in this paper.(ABSTRACT TRUNCATED AT 400 WORDS)

Kinetics of acyl transfer reactions in organic media catalysed by Candida antarctica lipase B.

PubMed

Martinelle, M; Hult, K

1995-09-06

The acyl transfer reactions catalysed by Candida antartica lipase B in organic media followed a bi-bi ping-pong mechanism, with competitive substrate inhibition by the alcohols used as acyl acceptors. The effect of organic solvents on Vm and Km was investigated. The Vm values in acetonitrile was 40-50% of those in heptane. High Km values in acetonitrile compared to those in heptane could partly be explained by an increased solvation of the substrates in acetonitrile. Substrate solvation caused a 10-fold change in substrate specificity, defined as (Vm/Km)ethyl octanoate/(Vm/Km)octanoic acid, going from heptane to acetonitrile. Deacylation was the rate determining step for the acyl transfer in heptane with vinyl- and ethyl octanoate as acyl donors and (R)-2-octanol as acyl acceptor. With 1-octanol, a rate determining deacylation step in heptane was indicated using the same acyl donors. Using 1-octanol as acceptor in heptane, S-ethyl thiooctanoate had a 25- to 30-fold lower Vm/Km value and vinyl octanoate a 4-fold higher Vm/Km value than that for ethyl octanoate. The difference showed to be a Km effect for vinyl octanoate and mainly a Km effect for S-ethyl thiooctanoate. The Vm values of the esterification of octanoic acid with different alcohols was 10-30-times lower than those for the corresponding transesterification of ethyl octanoate. The low activity could be explained by a low pH around the enzyme caused by the acid or a withdrawing of active enzyme by nonproductive binding by the acid.

Cyanide removal by Chinese vegetation--quantification of the Michaelis-Menten kinetics.

PubMed

Yu, Xiaozhang; Zhou, Puhua; Zhou, Xishi; Liu, Yunda

2005-07-01

Little is known about metabolism rates of environmental chemicals by vegetation. A good model compound to study the variation of rates among plant species is cyanide. Vascular plants possess an enzyme system that detoxifies cyanide by converting it to the amino acid asparagine. Knowledge of the kinetic parameters, the half-saturation constant (Km) and the maximum metabolic capacity (vmax), is very useful for enzyme characterization and biochemical purposes. The goal of this study is to find the enzyme kinetics (K(M) and vmax) during cyanide metabolism in the presence of Chinese vegetation, to provide quantitative data for engineered phytoremediation, and to investigate the variation of metabolic rates of plants. Detached leaves (1.0 g fresh weight) from 12 species out of 9 families were kept in glass vessels with 100 mL of aqueous solution spiked with potassium cyanide at 23 degrees C for 28 h. Four different treatment concentrations of cyanide were used, ranging from 0.44 to 7.69 mg CN/L. The disappearance of cyanide from the aqueous solution was analyzed spectrophotometrically. Realistic values of the half-saturation constant (KM) and the maximum metabolic capacity (vmax) were estimated by a computer program using non-linear regression treatments. As a comparison, Lineweaver-Burk plots were also used to estimate the kinetic parameters. The values obtained for K(M) and vmax varied with plant species. Using non-linear regression treatments, values of vmax and K(M) were found in a range between 6.68 and 21.91 mg CN/kg/h and 0.90 to 3.15 mg CN/L, respectively. The highest vmax was by Chinese elder (Sambucus chinensis), followed by upright hedge-parsley (Torilis japonica). The lowest Vmax was demonstrated by the hybrid willow (Salix matssudana x alba). However, the highest K(M) was found in the water lily (Nymphea teragona), followed by the poplar (Populus deltoides Marsh). The lowest K(M) was demonstrated by corn (Zea mays L.). The values of vmax were normally distributed with a mean of 13 mg CN/kg/h. Significant removal of cyanide from aqueous solution was observed in the presence of plant materials without phytotoxicity, even at high doses of cyanide. This gives rise to the conclusion that the Chinese plant species used in this study are all able to efficiently metabolize cyanide, although with different maximum metabolic capacities. A second conclusion is that the variation of metabolism rates between species is small. All these plants had a similar K(M), indicating the same enzyme is active in all plants. Detoxification of cyanide with trees seems to be a feasible option for cleaning soils and water contaminated with cyanide. For phytoremediation projects, screening appropriate plant species adapted to local conditions should be seriously considered. More chemicals should be investigated to find common principles of the metabolism of environmental chemicals by plants.

Spatial variations in the frequency-magnitude distribution of earthquakes at Mount Pinatubo volcano

USGS Publications Warehouse

Sanchez, J.J.; McNutt, S.R.; Power, J.A.; Wyss, M.

2004-01-01

The frequency-magnitude distribution of earthquakes measured by the b-value is mapped in two and three dimensions at Mount Pinatubo, Philippines, to a depth of 14 km below the summit. We analyzed 1406 well-located earthquakes with magnitudes MD ???0.73, recorded from late June through August 1991, using the maximum likelihood method. We found that b-values are higher than normal (b = 1.0) and range between b = 1.0 and b = 1.8. The computed b-values are lower in the areas adjacent to and west-southwest of the vent, whereas two prominent regions of anomalously high b-values (b ??? 1.7) are resolved, one located 2 km northeast of the vent between 0 and 4 km depth and a second located 5 km southeast of the vent below 8 km depth. The statistical differences between selected regions of low and high b-values are established at the 99% confidence level. The high b-value anomalies are spatially well correlated with low-velocity anomalies derived from earlier P-wave travel-time tomography studies. Our dataset was not suitable for analyzing changes in b-values as a function of time. We infer that the high b-value anomalies around Mount Pinatubo are regions of increased crack density, and/or high pore pressure, related to the presence of nearby magma bodies.

New constraints on micro-seismicity and stress state in the western part of the North Anatolian Fault Zone: Observations from a dense seismic array

NASA Astrophysics Data System (ADS)

Altuncu Poyraz, Selda; Teoman, M. Uğur; Türkelli, Niyazi; Kahraman, Metin; Cambaz, Didem; Mutlu, Ahu; Rost, Sebastian; Houseman, Gregory A.; Thompson, David A.; Cornwell, David; Utkucu, Murat; Gülen, Levent

2015-08-01

With the aim of extensively investigating the crustal structure beneath the western segment of the North Anatolian Fault Zone where it splays into northern and southern branches, a temporary seismic network (dense array for North Anatolia-DANA) consisting of 70 stations was deployed in early May 2012 and operated for 18 months in the Sakarya region during the FaultLab experiment. Out of 2437 events contaminated by explosions, we extracted 1371 well located earthquakes. The enhanced station coverage having a nominal station spacing of 7 km, lead to a minimum magnitude calculation of 0.1. Horizontal and vertical location uncertainties within the array do not exceed 0.8 km and 0.9 km, respectively. We observe considerable seismic activity along both branches of the fault where the depth of the seismogenic zone was mostly confined to 15 km. Using our current earthquake catalog we obtained a b-value of 1. We also mapped the b-value variation with depth and observed a gradual decrease. Furthermore, we determined the source parameters of 41 earthquakes with magnitudes greater than 1.8 using P-wave first motion polarity method. Regional Moment Tensor Inversion method was also applied to earthquakes with magnitudes greater than 3.0. Focal mechanism solutions confirm that Sakarya and its vicinity is stressed by a compressional regime showing a primarily oblique-slip motion character. Stress tensor analysis indicates that the maximum principal stress is aligned in WNW-ESE direction and the tensional axis is aligned in NNE-SSW direction.

Infrasonic array observations at I53US of the 2006 Augustine Volcano eruptions

USGS Publications Warehouse

Wilson, C.R.; Olson, J.V.; Szuberla, Curt A.L.; McNutt, Steve; Tytgat, Guy; Drob, Douglas P.

2006-01-01

The recent January 2006 Augustine eruptions, from the 11th to the 28th, have produced a series of 12 infrasonic signals that were observed at the I53US array at UAF. the eruption times for the signals were provided by the Alaska Volcanic Observatory at UAF using seismic sensors and a Chaparral microphone that are installed on Augustine Island. The bearing and distance of Augustine from I53US are, respectively, 207.8 degrees and 675 km. The analysis of the signals is done with a least-squares detector/estimator that calculates, from the 28 different sensor-pairs in the array, the mean of the cross-correlation maxima (MCCM), the horizontal trace-velocity and the azimuth of arrival of the signal using a sliding-window of 2000 data points. The data were bandpass filtered from 0.03 to 0.10 Hz. The data are digitized at a rate of 20 Hz. The average values of the signal parameters for all 12 Augustine signals are as follows: MCCM=0.85 (std 0.14), Trace-velocity=0.346 (std 0.016) km/sec, Azimuth=209 (std 2) deg. The celerity for each signal was calculated using the range 675 km and the individual travel times to I53US. The average celerity for all ten eruption signals was 0.27 (std 0.02) km/sec. Ray tracing studies, using mean values of the wind speed and temperature profiles (along the path) from NRL, have shown that there was propagation to I53US by both stratospheric and thermospheric ray paths from the volcano.

Visibility characteristics and the impacts of air pollutants and meteorological conditions over Shanghai, China.

PubMed

Xue, Dan; Li, Chengfan; Liu, Qian

2015-06-01

In China, visibility condition has become an important issue that concerns both society and the scientific community. In order to study visibility characteristics and its influencing factors, visibility data, air pollutants, and meteorological data during the year 2013 were obtained over Shanghai. The temporal variation of atmospheric visibility was analyzed. The mean value of daily visibility of Shanghai was 19.1 km. Visibility exhibited an obvious seasonal cycle. The maximum and minimum visibility occurred in September and December with the values of 27.5 and 7.7 km, respectively. The relationships between the visibility and air pollutant data were calculated. The visibility had negative correlation with NO2, CO, PM2.5, PM10, and SO2 and weak positive correlation with O3. Meteorological data were clustered into four groups to reveal the joint contribution of meteorological variables to the daily average visibility. Usually, under the meteorological condition of high temperature and wind speed, the visibility of Shanghai reached about 25 km, while visibility decreased to 16 km under the weather type of low wind speed and temperature and high relative humid. Principle component analysis was also applied to identify the main cause of visibility variance. The results showed that the low visibility over Shanghai was mainly due to the high air pollution concentrations associated with low wind speed, which explained the total variance of 44.99 %. These results provide new knowledge for better understanding the variations of visibility and have direct implications to supply sound policy on visibility improvement in Shanghai.

Formation and evolution of coronal rain observed by SDO/AIA on February 22, 2012

NASA Astrophysics Data System (ADS)

Vashalomidze, Z.; Kukhianidze, V.; Zaqarashvili, T. V.; Oliver, R.; Shergelashvili, B.; Ramishvili, G.; Poedts, S.; De Causmaecker, P.

2015-05-01

Context. The formation and dynamics of coronal rain are currently not fully understood. Coronal rain is the fall of cool and dense blobs formed by thermal instability in the solar corona towards the solar surface with acceleration smaller than gravitational free fall. Aims: We aim to study the observational evidence of the formation of coronal rain and to trace the detailed dynamics of individual blobs. Methods: We used time series of the 171 Å and 304 Å spectral lines obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO) above active region AR 11420 on February 22, 2012. Results: Observations show that a coronal loop disappeared in the 171 Å channel and appeared in the 304 Å line more than one hour later, which indicates a rapid cooling of the coronal loop from 1 MK to 0.05 MK. An energy estimation shows that the radiation is higher than the heat input, which indicates so-called catastrophic cooling. The cooling was accompanied by the formation of coronal rain in the form of falling cold plasma. We studied two different sequences of falling blobs. The first sequence includes three different blobs. The mean velocities of the blobs were estimated to be 50 km s-1, 60 km s-1 and 40 km s-1. A polynomial fit shows the different values of the acceleration for different blobs, which are lower than free-fall in the solar corona. The first and second blob move along the same path, but with and without acceleration, respectively. We performed simple numerical simulations for two consecutive blobs, which show that the second blob moves in a medium that is modified by the passage of the first blob. Therefore, the second blob has a relatively high speed and no acceleration, as is shown by observations. The second sequence includes two different blobs with mean velocities of 100 km s-1 and 90 km s-1, respectively. Conclusions: The formation of coronal rain blobs is connected with the process of catastrophic cooling. The different acceleration of different coronal rain blobs might be due to the different values in the density ratio of blob to corona. All blobs leave trails, which might be a result of continuous cooling in their tails. Two movies attached to Fig. 1 are available in electronic form at http://www.aanda.org

Remotely sensed MODIS wetland components for assessing the variability of methane emissions in Indian tropical/subtropical wetlands

NASA Astrophysics Data System (ADS)

Bansal, Sangeeta; Katyal, Deeksha; Saluja, Ridhi; Chakraborty, Monojit; Garg, J. K.

2018-02-01

Temperature and area fluctuations in wetlands greatly influence its various physico-chemical characteristics, nutrients dynamic, rates of biomass generation and decomposition, floral and faunal composition which in turn influence methane (CH4) emission rates. In view of this, the present study attempts to up-scale point CH4 flux from the wetlands of Uttar Pradesh (UP) by modifying two-factor empirical process based CH4 emission model for tropical wetlands by incorporating MODIS derived wetland components viz. wetland areal extent and corresponding temperature factors (Ft). This study further focuses on the utility of remotely sensed temperature response of CH4 emission in terms of Ft. Ft is generated using MODIS land surface temperature products and provides an important semi-empirical input for up-scaling CH4 emissions in wetlands. Results reveal that annual mean Ft values for UP wetlands vary from 0.69 (2010-2011) to 0.71(2011-2012). The total estimated area-wise CH4 emissions from the wetlands of UP varies from 66.47 Gg yr-1with wetland areal extent and Ft value of 2564.04 km2 and 0.69 respectively in 2010-2011 to 88.39 Gg yr-1with wetland areal extent and Ft value of 2720.16 km2 and 0.71 respectively in 2011-2012. Temporal analysis of estimated CH4 emissions showed that in monsoon season estimated CH4 emissions are more sensitive to wetland areal extent while in summer season sensitivity of estimated CH4 emissions is chiefly controlled by augmented methanogenic activities at high wetland surface temperatures.

Trends and future challenges of water resources in the Tigris-Euphrates Rivers basin in Iraq

NASA Astrophysics Data System (ADS)

Issa, I. E.; Al-Ansari, N. A.; Sherwany, G.; Knutsson, S.

2013-12-01

Iraq is one of the riparian countries within basins of Tigris-Euphrates Rivers in the Middle East region. The region is currently facing water shortage problems due to the increase of the demand and climate changes. In the present study, average monthly water flow measurements for 15 stream flow gaging stations within basins of these rivers in Iraq with population growth rate data in some of its part were used to evaluate the reality of the current situation and future challenges of water availability and demand in Iraq. The results showed that Iraq receives annually 70.29 km3 of water 45.4 and 25.52 km3 from River Tigris and Euphrates respectively. An amount of 18.04 km3 is supplied by its tributaries inside Iraq. The whole amount of water in the Euphrates Rivers comes outside the Iraqi borders. Annual decrease of the water inflow is 0.1335 km3 yr-1 for Tigris and 0.245 km3 yr-1 for Euphrates. This implies the annual percentage reduction of inflow rates for the two rivers is 0.294 and 0.960% respectively. Iraq consumes annually 88.89% (63.05 km3) of incoming water from the two rivers, where about 60.43 and 39.57% are from Rivers Tigris and Euphrates respectively. Water demand increases annually by 0.896 km3; of which 0.5271 and 0.475 km3 within Tigris and Euphrates basins respectively. The average water demand in 2020 will increase to 42.844 km3 yr-1 for Tigris basin and for Euphrates 29.225 km3 yr-1 (total 72.069 km3 yr-1), while water availability will decrease to 63.46 km3 yr-1. This means that the overall water shortage will be restricted to 8.61 km3.

An experiment to measure the one-way velocity of propagation of electromagnetic radiation

NASA Technical Reports Server (NTRS)

Kolen, P.; Torr, D. G.

1982-01-01

An experiment involving commercially available instrumentation to measure the velocity of the earth with respect to absolute space is described. The experiment involves the measurement of the one-way propagation velocity of electromagnetic radiation down a high-quality coaxial cable. It is demonstrated that the experiment is both physically meaningful and exceedingly simple in concept and in implementation. It is shown that with currently available commercial equipment one might expect to detect a threshold value for the component of velocity of the earth's motion with respect to absolute space in the equatorial plane of approximately 10 km/s, which greatly exceeds the velocity resolution required to detect the motion of the solar system with respect to the center of the galaxy.

[Estimation of average traffic emission factor based on synchronized incremental traffic flow and air pollutant concentration].

PubMed

Li, Run-Kui; Zhao, Tong; Li, Zhi-Peng; Ding, Wen-Jun; Cui, Xiao-Yong; Xu, Qun; Song, Xian-Feng

2014-04-01

On-road vehicle emissions have become the main source of urban air pollution and attracted broad attentions. Vehicle emission factor is a basic parameter to reflect the status of vehicle emissions, but the measured emission factor is difficult to obtain, and the simulated emission factor is not localized in China. Based on the synchronized increments of traffic flow and concentration of air pollutants in the morning rush hour period, while meteorological condition and background air pollution concentration retain relatively stable, the relationship between the increase of traffic and the increase of air pollution concentration close to a road is established. Infinite line source Gaussian dispersion model was transformed for the inversion of average vehicle emission factors. A case study was conducted on a main road in Beijing. Traffic flow, meteorological data and carbon monoxide (CO) concentration were collected to estimate average vehicle emission factors of CO. The results were compared with simulated emission factors of COPERT4 model. Results showed that the average emission factors estimated by the proposed approach and COPERT4 in August were 2.0 g x km(-1) and 1.2 g x km(-1), respectively, and in December were 5.5 g x km(-1) and 5.2 g x km(-1), respectively. The emission factors from the proposed approach and COPERT4 showed close values and similar seasonal trends. The proposed method for average emission factor estimation eliminates the disturbance of background concentrations and potentially provides real-time access to vehicle fleet emission factors.

Cytochrome P450 isoenzymes involved in rat liver microsomal metabolism of californine and protopine.

PubMed

Paul, Liane D; Springer, Dietmar; Staack, Roland F; Kraemer, Thomas; Maurer, Hans H

2004-02-06

Studies are described on the cytochrome P450 (CYP) isoenzyme dependence of the main metabolic steps of the Eschscholtzia californica alkaloids californine and protopine using rat liver microsomes. Preparations of E. californica are in use as phytopharmaceuticals and as herbal drugs of abuse. CYP isoenzyme dependences were studied using specific chemical inhibitors for CYP1A2, CYP2D1, and CYP3A2 (alpha-naphthoflavone, quinine, and ketoconazole, respectively). CYP2C11 was inhibited by specific antibodies for lack of specific chemical inhibitors. Californine N-demethylation was mainly catalyzed by CYP3A2 and to a minor extent by CYP1A2 and CYP2D1, but not by CYP2C11. CYP2D1 and CYP2C11 were shown to be mainly involved in demethylenation of both, californine and protopine, while CYP1A2 and CYP3A2 showed only minor contribution. Kinetic parameters of the reactions were established. K(m) and V(max) values for the californine N-demethylation were 4.5+/-4.7 microM and 22.9+/-13.7 min/mg protein (high affinity) and 161.3+/-16.7 microM and 311.8+/-39.4 min/mg protein (low affinity), respectively. Californine demethylenation and protopine demethylenation showed substrate inhibition and K(m) and V(max) values were 5.0+/-0.5 and 7.1+/-0.6 microM and 83.3+/-2.6 and 160.7+/-4.0 min/mg protein, respectively.

The role of CYP2D6 in primary and secondary oxidative metabolism of dextromethorphan: in vitro studies using human liver microsomes.

PubMed Central

Kerry, N L; Somogyi, A A; Bochner, F; Mikus, G

1994-01-01

1. The enzyme kinetics of dextromethorphan O-demethylation in liver microsomes from three extensive metabolisers (EM) with respect to CYP2D6 indicated high (Km1 2.2-9.4 microM) and low (Km2 55.5-307.3 microM) affinity sites whereas microsomes from two poor metabolisers (PM) indicated a single site (Km 560 and 157 microM). Similar differences were shown for 3-methoxymorphinan O-demethylation to 3-hydroxymorphinan (Km 6.9-9.6 microM in EM subjects; Km 307 and 213 microM in PM subjects). 2. Dextromethorphan O-demethylation was inhibited competitively by quinidine (Ki 0.1 microM), rac-perhexiline (Ki 0.4 microM), dextropropoxyphene (Ki 6 microM), rac-methadone (Ki 8 microM), and 3-methoxymorphinan (Ki 15 microM). These compounds were also potent inhibitors of 3-methoxymorphinan O-demethylation with IC50 values ranging from 0.02-12 microM. Anti-LKM1 serum inhibited both dextromethorphan and 3-methoxymorphinan O-demethylations in a titre-dependent manner. 3. The Michaelis-Menten constant for dextromethorphan N-demethylation to 3-methoxymorphinan (Km 632-977 microM) and dextrorphan N-demethylation to 3-hydroxymorphinan (Km 1571-4286 microM) did not differ between EM and PM microsomes. These N-demethylation reactions were not inhibited by quinidine and rac-methadone or LKM1 antibodies. 4. Dextromethorphan and 3-methoxymorphinan are metabolised by the same P450 isoform, CYP2D6, whereas the N-demethylation reactions are not carried out by CYP2D6. PMID:7826826

Water geochemistry of the Qiantangjiang River, East China: Chemical weathering and CO2 consumption in a basin affected by severe acid deposition

NASA Astrophysics Data System (ADS)

Liu, Wenjing; Shi, Chao; Xu, Zhifang; Zhao, Tong; Jiang, Hao; Liang, Chongshan; Zhang, Xuan; Zhou, Li; Yu, Chong

2016-09-01

The chemical composition of the Qiantangjiang River, the largest river in Zhejiang province in eastern China, was measured to understand the chemical weathering of rocks and the associated CO2 consumption and anthropogenic influences within a silicate-dominated river basin. The average total dissolved solids (TDS, 113 mg l-1) and total cation concentration (TZ+, 1357 μeq l-1) of the river waters are comparable with those of global major rivers. Ca2+ and HCO3- followed by Na2+ and SO42-, dominate the ionic composition of the river water. There are four major reservoirs (carbonates, silicates, atmospheric and anthropogenic inputs) contributing to the total dissolved load of the investigated rivers. The dissolved loads of the rivers are dominated by both carbonate and silicate weathering, which together account for about 76.3% of the total cationic load origin. The cationic chemical weathering rates of silicate and carbonate for the Qiantangjiang basin are estimated to be approximately 4.9 ton km-2 a-1 and 13.9 ton km-2 a-1, respectively. The calculated CO2 consumption rates with the assumption that all the protons involved in the weathering reaction are provided by carbonic acid are 369 × 103 mol km-2 a-1 and 273 × 103 mol km-2 a-1 by carbonate and silicate weathering, respectively. As one of the most severe impacted area by acid rain in China, H2SO4 from acid precipitation is also an important proton donor in weathering reactions. When H2SO4 is considered, the CO2 consumption rates for the river basin are estimated at 286 × 103 mol km-2 a-1 for carbonate weathering and 211 × 103 mol km-2 a-1 for silicate weathering, respectively. The results highlight that the drawdown effect of CO2 consumption by carbonate and silicate weathering can be largely overestimated if the role of sulfuric acid is ignored, especially in the area heavily impacted by acid deposition like Qiantangjiang basin. The actual CO2 consumption rates (after sulfuric acid weathering effect deduction) is only about 77% of the value calculated with the assumption that carbonic acid donates all the protons involved in the weathering reaction.

Model study of atmospheric transport using carbon 14 and strontium 90 as inert tracers

NASA Technical Reports Server (NTRS)

Kinnison, D. E.; Johnston, H. S.; Wuebbles, D. J.

1994-01-01

The observed excess carbon 14 in the atmosphere from 1963 to 1970 provides unique, but limited, data up to an altitude of about 35 km for testing the air motions calculated by 11 multidimensional atmospheric models. Strontium 90 measurements in the atmosphere from 1964 to mid-1967 provide data that have more latitude coverage than those of carbon 14 and are useful for testing combined models of air motions and aerosol settling. Model calculations for carbon 14 begin at October 1963, 9 months after the conclusion of the nuclear bomb tests; the initial conditions for the calculations are derived by three methods, each of which agrees fairly well with measured carbon 14 in October 1963 and each of which has widely different values in regions of the stratosphere where there were no carbon 14 measurements. The model results are compared to the stratospheric measurements, not as if the observed data were absolute standards, but in an effort to obtain new insight about the models and about the atmosphere. The measured carbon 14 vertical profiles at 31 deg N are qualitatively different from all of the models; the measured vertical profiles show a maximum mixing ratio in the altitude range of 20 to 25 km from October 1963 through July 1966, but all modeled profiles show mixing ratio maxima that increase in altitude from 20 km in October 1963 to greater than 40 km by April 1966. Both carbon 14 and strontium 90 data indicate that the models differ substantially among themselves with respect to stratosphere-troposphere exchange rate, but the modeled carbon 14 stratospheric residence times indicate that differences among the models are small with respect to transport rate between the middle stratosphere and the lower stratosphere. Strontium 90 data indicate that aerosol settling is important up to at least 35 km altitude. Relative to the measurements, about three quarters of the models transport carbon 14 from the lower stratosphere to the troposphere too rapidly, and all models with all three sets of initial conditions appear to sweep carbon 14 out of the midstratosphere (above 28 km) much more slowly than was observed from 1963 to 1970. Atmospheric dynamicists should seriously consider that the carbon 14 measurements imply with respect to advection in the midstratosphere.

Measurements of reactive nitrogen produced by tropical thunderstorms during BIBLE-C

NASA Astrophysics Data System (ADS)

Koike, M.; Kondo, Y.; Kita, K.; Takegawa, N.; Nishi, N.; Kashihara, T.; Kawakami, S.; Kudoh, S.; Blake, D.; Shirai, T.; Liley, B.; Ko, M.; Miyazaki, Y.; Kawasaki, Z.; Ogawa, T.

2007-09-01

The Biomass Burning and Lightning Experiment phase C (BIBLE-C) aircraft mission was carried out near Darwin, Australia (12°S, 131°E) in December 2000. This was the first aircraft experiment designed to estimate lightning NO production rates in the tropics, where production is considered to be most intense. During the two flights (flights 10 and 13 made on December 9 and 11-12, respectively) enhancements of NOx (NO + NO2) up to 1000 and 1600 parts per trillion by volume (pptv, 10-s data) were observed at altitudes between 11.5 and 14 km. The Geostationary Meteorological Satellite (GMS) cloud (brightness temperature) data and ground-based lightning measurements by the Global Positioning and Tracking System (GPATS) indicate that there were intensive lightning events over the coast of the Gulf of Carpentaria, which took place upstream from our measurement area 10 to 14 h prior to the measurements. For these two flights, air in which NOx exceeded 100 pptv extended over 620 × 140 and 400 × 170 km2 (wind direction × perpendicular direction), respectively, suggesting a significant impact of lightning NO production on NOx levels in the tropics. We estimate the amount of NOx observed between 11.5 and 14 km produced by the thunderstorms to be 3.3 and 1.8 × 1029 NO molecules for flights 10 and 13, respectively. By using the GPATS lightning flash count data, column NO production rates are estimated to be 1.9-4.4 and 21-49 × 1025 NO molecules per single flash for these two flight data sets. In these estimations, it is assumed that the column NO production between 0 and 16 km is greater than the observed values between 11.5 and 14 km by a factor of 3.2, which is derived using results reported by Pickering et al. (1998). There are however large uncertainties in the GPATS lightning data in this study and care must be made when the production rates are referred. Uncertainties in these estimates are discussed. The impact on the ozone production rate is also described.

Failure Wave in DEDF and Soda-Lime Glass During Rod Impact

NASA Astrophysics Data System (ADS)

Orphal, Dennis; Behner, Thilo; Anderson, Charles; Templeton, Douglas

2005-07-01

Investigations of glass by planar, and classical and symmetric Taylor impact experiments reveal that failure wave velocity U/F depends on impact velocity, geometry, and the type of glass. U/F typically increases with impact velocity to between ˜ 1.4 C/S and C/L (shear and longitudinal wave velocities, respectively). This paper reports the results of direct high-speed photographic measurements of the failure wave for gold rod impact from 1.2 and 2.0 km/s on DEDF glass (C/S = 2.0, C/L =3.5 km/s). The average rod penetration velocity, u, was measured using flash X-rays. Gold rods eliminated penetrator strength effects. U/F for gold rod impact on DEDF is ˜ 1.0-1.2 km/s, which is considerably less than C/S. The increase of u with impact velocity is greater than that of U/F. These results are confirmed by soda-lime glass impact on a gold rod at an impact velocity of 1300 m/s. Similar results are found in``edge-on-impact'' tests; U/F values of 1.4 km/s and 2.4-2.6 km/s in soda-lime glass are reported for W-alloy rod impact, considerably less than C/S (3.2 km/s) [1,2]. [1] Bless, et. al.(1990) AIP Proc. Shock Comp. Cond. Matter---1989, pp. 939-942 (1990) [2] E. L. Zilberbrand, et. al. (1999) Int. J. Impact Engng., 23, 995-1001 (1999).

Determining Cloud Parameters with the Curve-Of-Growth: Application Eta Car

NASA Technical Reports Server (NTRS)

Vieira, G. L.; Gull, T. R.; Bruhweiler, F.; Nielsen, K. E.; Verner, E. M.

2004-01-01

We have investigated the NUV part of the Eta Car spectrum, using data with high spatial and high spectral resolving power obtained with the HST/STIS under the Treasury Program. The NUV spectrum of Eta Car Shows a great contribution of absorption features from neutral and singly ionized elements along the line-of-sight. A large number of velocity systems have been observed. The two most prominent, with Doppler shifts corresponding to -146 and -513 km/s respectively, are shown to be useful for investigations of the gaseous environments responsible for the absorption. The -146 and the -513 km/s velocity systems display different characteristics regarding the ionization state and spectral line width, which suggest that they originate at different distances from the central object. We have investigated the absorption structures before the spectroscopic minimum, occurring during the summer of 2003, with a standard curve-of-growth. We have independently derived the column density and the b-value for the Fe II (-146 km/s) and Ti II (-513 km/s) velocity systems. The excitation temperature has been determined for the -146 km/s velocity system using the photo-ionization code \\textsc(cloudy). The -146 km/s velocity structure shows noticeable variation over the spectroscopic minimum. The sudden appearance and disappearance of Ti II and V II are astonishing. We have made an attempt to analyze these variations with the curve-of-growth method and will present preliminary results.

Preferential inhibition of xanthine oxidase by 2-amino-6-hydroxy-8-mercaptopurine and 2-amino-6-purine thiol.

PubMed

Kalra, Sukirti; Jena, Gopabandhu; Tikoo, Kulbhushan; Mukhopadhyay, Anup Kumar

2007-05-18

The anticancer drug, 6-mercaptopurine (6MP) is subjected to metabolic clearance through xanthine oxidase (XOD) mediated hydroxylation, producing 6-thiouric acid (6TUA), which is excreted in urine. This reduces the effective amount of drug available for therapeutic efficacy. Co-administration of allopurinol, a suicide inhibitor of XOD, which blocks the hydroxylation of 6MP inadvertently enhances the 6MP blood level, counters this reduction. However, allopurinol also blocks the hydroxylation of hypoxanthine, xanthine (released from dead cancer cells) leading to their accumulation in the body causing biochemical complications such as xanthine nephropathy. This necessitates the use of a preferential XOD inhibitor that selectively inhibits 6MP transformation, but leaves xanthine metabolism unaffected. Here, we have characterized two such unique inhibitors namely, 2-amino-6-hydroxy-8-mercaptopurine (AHMP) and 2-amino-6-purinethiol (APT) on the basis of IC50 values, residual activity in bi-substrate simulative reaction and the kinetic parameters like Km, Ki, kcat. The IC50 values of AHMP for xanthine and 6MP as substrate are 17.71 +/- 0.29 microM and 0.54 +/- 0.01 microM, respectively and the IC50 values of APT for xanthine and 6MP as substrates are 16.38 +/- 0.21 microM and 2.57 +/- 0.08 microM, respectively. The Ki values of XOD using AHMP as inhibitor with xanthine and 6MP as substrate are 5.78 +/- 0.48 microM and 0.96 +/- 0.01 microM, respectively. The Ki values of XOD using APT as inhibitor with xanthine and 6MP as substrate are 6.61 +/- 0.28 microM and 1.30 +/- 0.09 microM. The corresponding Km values of XOD using xanthine and 6MP as substrate are 2.65 +/- 0.02 microM and 6.01 +/- 0.03 microM, respectively. The results suggest that the efficiency of substrate binding to XOD and its subsequent catalytic hydroxylation is much superior for xanthine in comparison to 6MP. In addition, the efficiency of the inhibitor binding to XOD is much more superior when 6MP is the substrate instead of xanthine. We further undertook the toxicological evaluation of these inhibitors in a single dose acute toxicity study in mice and our preliminary experimental results suggested that the inhibitors were equally non-toxic in the tested doses. We conclude that administration of either APT or AHMP along with the major anti-leukemic drug 6MP might serve as a good combination cancer chemotherapy regimen.

Global carbonyl sulfide (OCS) measured by MIPAS/Envisat during 2002-2012

NASA Astrophysics Data System (ADS)

Glatthor, Norbert; Höpfner, Michael; Leyser, Adrian; Stiller, Gabriele P.; von Clarmann, Thomas; Grabowski, Udo; Kellmann, Sylvia; Linden, Andrea; Sinnhuber, Björn-Martin; Krysztofiak, Gisèle; Walker, Kaley A.

2017-02-01

We present a global carbonyl sulfide (OCS) data set covering the period June 2002 to April 2012, derived from FTIR (Fourier transform infrared) limb emission spectra measured with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on the ENVISAT satellite. The vertical resolution is 4-5 km in the height region 6-15 km and 15 at 40 km altitude. The total estimated error amounts to 40-50 pptv between 10 and 20 km and to 120 pptv at 40 km altitude. MIPAS OCS data show no systematic bias with respect to balloon observations, with deviations mostly below ±50 pptv. However, they are systematically higher than the OCS volume mixing ratios of the ACE-FTS instrument on SCISAT, with maximum deviations of up to 100 pptv in the altitude region 13-16 km. The data set of MIPAS OCS exhibits only moderate interannual variations and low interhemispheric differences. Average concentrations at 10 km altitude range from 480 pptv at high latitudes to 500-510 pptv in the tropics and at northern mid-latitudes. Seasonal variations at 10 km altitude amount to up to 35 pptv in the Northern and up to 15 pptv in the Southern Hemisphere. Northern hemispheric OCS abundances at 10 km altitude peak in June in the tropics and around October at high latitudes, while the respective southern hemispheric maxima were observed in July and in November. Global OCS distributions at 250 hPa (˜ 10-11 km) show enhanced values at low latitudes, peaking during boreal summer above the western Pacific and the Indian Ocean, which indicates oceanic release. Further, a region of depleted OCS amounts extending from Brazil to central and southern Africa was detected at this altitude, which is most pronounced in austral summer. This depletion is related to seasonally varying vegetative uptake by the tropical forests. Typical signatures of biomass burning like the southern hemispheric biomass burning plume are not visible in MIPAS data, indicating that this process is only a minor source of upper tropospheric OCS. At the 150 hPa level (˜ 13-14 km) enhanced amounts of OCS were also observed inside the Asian monsoon anticyclone, but this enhancement is not especially outstanding compared to other low latitude regions at the same altitude. At the 80 hPa level (˜ 17-18 km), equatorward transport of mid-latitude air masses containing lower OCS amounts around the summertime anticyclones was observed. A significant trend could not be detected in upper tropospheric MIPAS OCS amounts, which points to globally balanced sources and sinks. Simulations with the ECHAM-MESSy model reproduce the observed latitudinal cross sections fairly well.

Speed and heart-rate profiles in skating and classical cross-country skiing competitions.

PubMed

Bolger, Conor M; Kocbach, Jan; Hegge, Ann Magdalen; Sandbakk, Øyvind

2015-10-01

To compare the speed and heart-rate profiles during international skating and classical competitions in male and female world-class cross-country skiers. Four male and 5 female skiers performed individual time trials of 15 km (men) and 10 km (women) in the skating and classical techniques on 2 consecutive days. Races were performed on the same 5-km course. The course was mapped with GPS and a barometer to provide a valid course and elevation profile. Time, speed, and heart rate were determined for uphill, flat, and downhill terrains throughout the entire competition by wearing a GPS and a heart-rate monitor. Times in uphill, flat, and downhill terrain were ~55%, 15-20%, and 25-30%, respectively, of the total race time for both techniques and genders. The average speed differences between skating and classical skiing were 9% and 11% for men and women, respectively, and these values were 12% and 15% for uphill, 8% and 13% for flat (all P < .05), and 2% and 1% for downhill terrain. The average speeds for men were 9% and 11% faster than for women in skating and classical, respectively, with corresponding numbers of 11% and 14% for uphill, 6% and 11% for flat, and 4% and 5% for downhill terrain (all P < .05). Heart-rate profiles were relatively independent of technique and gender. The greatest performance differences between the skating and classical techniques and between the 2 genders were found on uphill terrain. Therefore, these speed differences could not be explained by variations in exercise intensity.

Low-Concentration Kinetics of Atmospheric CH4 Oxidation in Soil and Mechanism of NH4+ Inhibition

PubMed Central

Gulledge, Jay; Schimel, Joshua P.

1998-01-01

NH4+ inhibition kinetics for CH4 oxidation were examined at near-atmospheric CH4 concentrations in three upland forest soils. Whether NH4+-independent salt effects could be neutralized by adding nonammoniacal salts to control samples in lieu of deionized water was also investigated. Because the levels of exchangeable endogenous NH4+ were very low in the three soils, desorption of endogenous NH4+ was not a significant factor in this study. The Km(app) values for water-treated controls were 9.8, 22, and 57 nM for temperate pine, temperate hardwood, and birch taiga soils, respectively. At CH4 concentrations of ≤15 μl liter−1, oxidation followed first-order kinetics in the fine-textured taiga soil, whereas the coarse-textured temperate soils exhibited Michaelis-Menten kinetics. Compared to water controls, the Km(app) values in the temperate soils increased in the presence of NH4+ salts, whereas the Vmax(app) values decreased substantially, indicating that there was a mixture of competitive and noncompetitive inhibition mechanisms for whole NH4+ salts. Compared to the corresponding K+ salt controls, the Km(app) values for NH4+ salts increased substantially, whereas the Vmax(app) values remained virtually unchanged, indicating that NH4+ acted by competitive inhibition. Nonammoniacal salts caused inhibition to increase with increasing CH4 concentrations in all three soils. In the birch taiga soil, this trend occurred with both NH4+ and K+ salts, and the slope of the increase was not affected by the addition of NH4+. Hence, the increase in inhibition resulted from an NH4+-independent mechanism. These results show that NH4+ inhibition of atmospheric CH4 oxidation resulted from enzymatic substrate competition and that additional inhibition that was not competitive resulted from a general salt effect that was independent of NH4+. PMID:9797279

Lightning climatology in the Congo Basin: detailed analysis

NASA Astrophysics Data System (ADS)

Soula, Serge; Kigotsi, Jean; Georgis, Jean-François; Barthe, Christelle

2016-04-01

The lightning climatology of the Congo Basin including several countries of Central Africa is analyzed in detail for the first time. It is based on World Wide Lightning Location Network (WWLLN) data for the period from 2005 to 2013. A comparison of these data with the Lightning Imaging Sensor (LIS) data for the same period shows the WWLLN detection efficiency (DE) in the region increases from about 1.70 % in the beginning of the period to 5.90 % in 2013, relative to LIS data, but not uniformly over the whole 2750 km × 2750 km area. Both the annual flash density and the number of stormy days show sharp maximum values localized in eastern of Democratic Republic of Congo (DRC) and west of Kivu Lake, regardless of the reference year and the period of the year. These maxima reach 12.86 fl km-2 and 189 days, respectively, in 2013, and correspond with a very active region located at the rear of the Virunga mountain range characterised with summits that can reach 3000 m. The presence of this range plays a role in the thunderstorm development along the year. The estimation of this local maximum of the lightning density by taking into account the DE, leads to a value consistent with that of the global climatology by Christian et al. (2003) and other authors. Thus, a mean maximum value of about 157 fl km-2 y-1 is found for the annual lightning density. The zonal distribution of the lightning flashes exhibits a maximum between 1°S and 2°S and about 56 % of the flashes located below the equator in the 10°S - 10°N interval. The diurnal evolution of the flash rate has a maximum between 1400 and 1700 UTC, according to the reference year, in agreement with previous works in other regions of the world.

The slab thickness of the mid-latitude ionosphere.

NASA Technical Reports Server (NTRS)

Titheridge, J. E.

1973-01-01

The thickness of the peak of the ionosphere depends primarily on the temperature T sub n of the neutral gas, and corresponds approximately to an alpha-Chapman layer at a temperature of 0.87T sub n. The overall slab thickness, as given by Faraday rotation measurements, is then tau = 0.22T sub n + 7 km. Expansion of the topside ionosphere, and changes in the E- and F1-regions increase tau by about 20 km during the day in summer. Near solar minimum, tau is increased by a lowering of the O(+)/H(+) transition height; if the neutral temperature T sub n is estimated, this height can be obtained from observed values of tau. Hourly values of slab thickness were determined over a period of 6 yr at 34 and 42 S. Near solar maximum the nighttime values were about 260 km in all seasons. The corresponding neutral temperatures agree with satellite drag values; they show a semiannual variation of 14% and a seasonal change of 5%. Daytime values of tau were about 230 km in winter and 320 km in summer, implying a seasonal change of 30% in T sub n.

Vega: A rapidly rotating pole-on star

NASA Technical Reports Server (NTRS)

Gulliver, Austin F.; Hill, Graham; Adelman, Saul J.

1994-01-01

High-dispersion (2.4 A/mm), ultrahigh signal-to-noise ratio (3000:1) Reticon spectra of Vega revealed two distinct types of profiles. The strong lines exhibit classical rotational profiles with enhanced wings, but the weak lines have distinctly different, flat-bottomed profiles. Using ATLAS9 model atmopheres and SYNTHE synthetic spectra, Vega has been modeled as a rapidly rotating, pole-on star with a gradient in temperature and gravity over the photosphere. By fitting to the flat-bottomed line profiles of Fe 1 lambda 4528 and Ti 2 lambda 4529, we find least-squares fit values of V sin i = 21.8 plus or minus 0.2 km/sec polar T(sub eff) = 9695 plus or minus 25 K, polar log(base 10)g = 3.75 plus or minus 0.02 dex, V(sub eq) = 245 plus or minus 15 km/sec, and inclination 5 deg .1 plus or minus 0 deg .3. The variations in T(sub eff) and log(base 10)g over the photosphere total 390 K and 0.08 dex, respectively. Assuming V sin i = 21.8 km/sec, an independent fit to the observed continuous flux from 1200 to 10,500 A produced a similar set of values with polar T(sub eff) = 9595 plus or minus 20 K, polar log(base 10)g = 3.80 plus or minus 0.03 dex, and inclination 6 deg .0 plus or minus 0 deg .7.

Km and kcat. values for [6,6,7,7-2H]7,8(6H)-dihydropterin and 2,6-diamino-5-iminopyrimidin-4-one with dihydropteridine reductase.

PubMed Central

Armarego, W L; Randles, D; Taguchi, H

1983-01-01

The Km and kcat. values for [6,6,7,7-2H]7,8(6H)-dihydropterin and 2,6-diamino-5-iminopyrimidin-4-one were determined for dihydropteridine reductase (EC 1.6.99.10) from two sources. The parameters of the pterin are of the same order as those of the most effective substrates of dihydropteridine reductase. The Km values of the pterin are one order of magnitude smaller than those of the pyrimidinone, although the kcat. values are of the same order. PMID:6870836

Towards Monitoring Biodiversity in Amazonian Forests: How Regular Samples Capture Meso-Scale Altitudinal Variation in 25 km2 Plots

PubMed Central

Norris, Darren; Fortin, Marie-Josée; Magnusson, William E.

2014-01-01

Background Ecological monitoring and sampling optima are context and location specific. Novel applications (e.g. biodiversity monitoring for environmental service payments) call for renewed efforts to establish reliable and robust monitoring in biodiversity rich areas. As there is little information on the distribution of biodiversity across the Amazon basin, we used altitude as a proxy for biological variables to test whether meso-scale variation can be adequately represented by different sample sizes in a standardized, regular-coverage sampling arrangement. Methodology/Principal Findings We used Shuttle-Radar-Topography-Mission digital elevation values to evaluate if the regular sampling arrangement in standard RAPELD (rapid assessments (“RAP”) over the long-term (LTER [“PELD” in Portuguese])) grids captured patters in meso-scale spatial variation. The adequacy of different sample sizes (n = 4 to 120) were examined within 32,325 km2/3,232,500 ha (1293×25 km2 sample areas) distributed across the legal Brazilian Amazon. Kolmogorov-Smirnov-tests, correlation and root-mean-square-error were used to measure sample representativeness, similarity and accuracy respectively. Trends and thresholds of these responses in relation to sample size and standard-deviation were modeled using Generalized-Additive-Models and conditional-inference-trees respectively. We found that a regular arrangement of 30 samples captured the distribution of altitude values within these areas. Sample size was more important than sample standard deviation for representativeness and similarity. In contrast, accuracy was more strongly influenced by sample standard deviation. Additionally, analysis of spatially interpolated data showed that spatial patterns in altitude were also recovered within areas using a regular arrangement of 30 samples. Conclusions/Significance Our findings show that the logistically feasible sample used in the RAPELD system successfully recovers meso-scale altitudinal patterns. This suggests that the sample size and regular arrangement may also be generally appropriate for quantifying spatial patterns in biodiversity at similar scales across at least 90% (≈5 million km2) of the Brazilian Amazon. PMID:25170894

Size and Shape of Chariklo from Multi-epoch Stellar Occultations

NASA Astrophysics Data System (ADS)

Leiva, R.; Sicardy, B.; Camargo, J. I. B.; Ortiz, J.-L.; Desmars, J.; Bérard, D.; Lellouch, E.; Meza, E.; Kervella, P.; Snodgrass, C.; Duffard, R.; Morales, N.; Gomes-Júnior, A. R.; Benedetti-Rossi, G.; Vieira-Martins, R.; Braga-Ribas, F.; Assafin, M.; Morgado, B. E.; Colas, F.; De Witt, C.; Sickafoose, A. A.; Breytenbach, H.; Dauvergne, J.-L.; Schoenau, P.; Maquet, L.; Bath, K.-L.; Bode, H.-J.; Cool, A.; Lade, B.; Kerr, S.; Herald, D.

2017-10-01

We use data from five stellar occultations observed between 2013 and 2016 to constrain Chariklo’s size and shape, and the ring reflectivity. We consider four possible models for Chariklo (sphere, Maclaurin spheroid, triaxial ellipsoid, and Jacobi ellipsoid), and we use a Bayesian approach to estimate the corresponding parameters. The spherical model has a radius R = 129 ± 3 km. The Maclaurin model has equatorial and polar radii a=b={143}-6+3 {km} and c={96}-4+14 {km}, respectively, with density {970}-180+300 {kg} {{{m}}}-3. The ellipsoidal model has semiaxes a={148}-4+6 {km}, b={132}-5+6 {km}, and c={102}-8+10 {km}. Finally, the Jacobi model has semiaxes a = 157 ± 4 km, b = 139 ± 4 km, and c = 86 ± 1 km, and density {796}-4+2 {kg} {{{m}}}-3. Depending on the model, we obtain topographic features of 6-11 km, typical of Saturn icy satellites with similar size and density. We constrain Chariklo’s geometric albedo between 3.1% (sphere) and 4.9% (ellipsoid), while the ring I/F reflectivity is less constrained between 0.6% (Jacobi) and 8.9% (sphere). The ellipsoid model explains both the optical light curve and the long-term photometry variation of the system, giving a plausible value for the geometric albedo of the ring particles of 10%-15%. The derived mass of Chariklo of 6-8 × 1018 kg places the rings close to 3:1 resonance between the ring mean motion and Chariklo’s rotation period. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

Hydrostatic and non-hydrostatic simulations of dense waters cascading off a shelf: The East Greenland case

NASA Astrophysics Data System (ADS)

Magaldi, Marcello G.; Haine, Thomas W. N.

2015-02-01

The cascade of dense waters of the Southeast Greenland shelf during summer 2003 is investigated with two very high-resolution (0.5-km) simulations. The first simulation is non-hydrostatic. The second simulation is hydrostatic and about 3.75 times less expensive. Both simulations are compared to a 2-km hydrostatic run, about 31 times less expensive than the 0.5 km non-hydrostatic case. Time-averaged volume transport values for deep waters are insensitive to the changes in horizontal resolution and vertical momentum dynamics. By this metric, both lateral stirring and vertical shear instabilities associated with the cascading process are accurately parameterized by the turbulent schemes used at 2-km horizontal resolution. All runs compare well with observations and confirm that the cascade is mainly driven by cyclones which are linked to dense overflow boluses at depth. The passage of the cyclones is also associated with the generation of internal gravity waves (IGWs) near the shelf. Surface fields and kinetic energy spectra do not differ significantly between the runs for horizontal scales L > 30 km. Complex structures emerge and the spectra flatten at scales L < 30 km in the 0.5-km runs. In the non-hydrostatic case, additional energy is found in the vertical kinetic energy spectra at depth in the 2 km < L < 10 km range and with frequencies around 7 times the inertial frequency. This enhancement is missing in both hydrostatic runs and is here argued to be due to the different IGW evolution and propagation offshore. The different IGW behavior in the non-hydrostatic case has strong implications for the energetics: compared to the 2-km case, the baroclinic conversion term and vertical kinetic energy are about 1.4 and at least 34 times larger, respectively. This indicates that the energy transfer from the geostrophic eddy field to IGWs and their propagation away from the continental slope is not properly represented in the hydrostatic runs.

Synthesis and Evaluation of Chlorinated Substrate Analogues for Farnesyl Diphosphate Synthase

PubMed Central

Heaps, Nicole A.; Poulter, C. Dale

2011-01-01

Substrate analogues for isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), where the C3 methyl groups were replaced by chlorine, were synthesized and evaluated as substrates for avian farnesyl diphosphate synthase (FPPase). The IPP analogue (3-ClIPP) was a co-substrate when incubated with dimethylallyl diphosphate (DMAPP) or geranyl diphosphate (GPP) to give the corresponding chlorinated analogues of geranyl diphosphate (3-ClGPP) and farnesyl diphosphate (3-ClFPP), respectively. No products were detected in incubations of 3-ClIPP with 3-ClDMAPP. Incubation of IPP with 3-ClDMAPP gave 11-ClFPP as the sole product. Values of KM3-ClIPP (with DMAPP) and KM3-ClDMAPP (with IPP) were similar to those for IPP and DMAPP, however values of kcat for both analogues were substantially lower. These results are consistent with a dissociative electrophilic alkylation mechanism where the rate-limiting step changes from heterolytic cleavage of the carbon-oxygen bond in the allylic substrate to alkylation of the double bond of the homoallylic substrate. PMID:21344952

Spatial variations in the frequency-magnitude distribution of earthquakes at Soufriere Hills Volcano, Montserrat, West Indies

USGS Publications Warehouse

Power, J.A.; Wyss, M.; Latchman, J.L.

1998-01-01

The frequency-magnitude distribution of earthquakes measured by the b-value is determined as a function of space beneath Soufriere Hills Volcano, Montserrat, from data recorded between August 1, 1995 and March 31, 1996. A volume of anomalously high b-values (b > 3.0) with a 1.5 km radius is imaged at depths of 0 and 1.5 km beneath English's Crater and Chance's Peak. This high b-value anomaly extends southwest to Gage's Soufriere. At depths greater than 2.5 km volumes of comparatively low b-values (b-1) are found beneath St. George's Hill, Windy Hill, and below 2.5 km depth and to the south of English's Crater. We speculate the depth of high b-value anomalies under volcanoes may be a function of silica content, modified by some additional factors, with the most siliceous having these volumes that are highly fractured or contain high pore pressure at the shallowest depths. Copyright 1998 by the American Geophysical Union.

Well-behaved relativistic charged super-dense star models

NASA Astrophysics Data System (ADS)

Faruqi, Shahab; Pant, Neeraj

2012-10-01

A new class of charged super-dense star models is obtained by using an electric intensity, which involves a parameter, K. The metric describing the model shares its metric potential g 44 with that of Durgapal's fourth solution (J. Phys. A, Math. Gen. 15:2637, 1982). The pressure-free surface is kept at the density ρ b =2×1014 g/cm3 and joins smoothly with the Reissner-Nordstrom solution. The charge analogues are well-behaved for a wide range, 0≤ K≤59, with the optimum value of X=0.264 i.e. the pressure, density, pressure-density ratio and velocity of sound are monotonically decreasing and the electric intensity is monotonically increasing in nature for the given range of the parameter K. The maximum mass and the corresponding radius occupied by the neutral solution are 4.22 M Θ and 20 km, respectively for X=0.264. For the charged solution, the maximum mass and radius are defined by the expressions M≈(0.0059 K+4.22) M Θ and r b ≈-0.021464 K+20 km respectively.

An efficient ribitol-specific dehydrogenase from Enterobacter aerogenes.

PubMed

Singh, Ranjitha; Singh, Raushan; Kim, In-Won; Sigdel, Sujan; Kalia, Vipin C; Kang, Yun Chan; Lee, Jung-Kul

2015-05-01

An NAD(+)-dependent ribitol dehydrogenase from Enterobacter aerogenes KCTC 2190 (EaRDH) was cloned and successfully expressed in Escherichia coli. The complete 729-bp gene was amplified, cloned, expressed, and subsequently purified in an active soluble form using nickel affinity chromatography. The enzyme had an optimal pH and temperature of 11.0 and 45°C, respectively. Among various polyols, EaRDH exhibited activity only toward ribitol, with Km, Vmax, and kcat/Km values of 10.3mM, 185Umg(-1), and 30.9s(-1)mM(-1), respectively. The enzyme showed strong preference for NAD(+) and displayed no detectable activity with NADP(+). Homology modeling and sequence analysis of EaRDH, along with its biochemical properties, confirmed that EaRDH belongs to the family of NAD(+)-dependent ribitol dehydrogenases, a member of short-chain dehydrogenase/reductase (SCOR) family. EaRDH showed the highest activity and unique substrate specificity among all known RDHs. Homology modeling and docking analysis shed light on the molecular basis of its unusually high activity and substrate specificity. Copyright © 2015 Elsevier Inc. All rights reserved.

Identification of functional amino acid residues involved in polyamine and agmatine transport by human organic cation transporter 2.

PubMed

Higashi, Kyohei; Imamura, Masataka; Fudo, Satoshi; Uemura, Takeshi; Saiki, Ryotaro; Hoshino, Tyuji; Toida, Toshihiko; Kashiwagi, Keiko; Igarashi, Kazuei

2014-01-01

Polyamine (putrescine, spermidine and spermine) and agmatine uptake by the human organic cation transporter 2 (hOCT2) was studied using HEK293 cells transfected with pCMV6-XL4/hOCT2. The Km values for putrescine and spermidine were 7.50 and 6.76 mM, and the Vmax values were 4.71 and 2.34 nmol/min/mg protein, respectively. Spermine uptake by hOCT2 was not observed at pH 7.4, although it inhibited both putrescine and spermidine uptake. Agmatine was also taken up by hOCT2, with Km value: 3.27 mM and a Vmax value of 3.14 nmol/min/mg protein. Amino acid residues involved in putrescine, agmatine and spermidine uptake by hOCT2 were Asp427, Glu448, Glu456, Asp475, and Glu516. In addition, Glu524 and Glu530 were involved in putrescine and spermidine uptake activity, and Glu528 and Glu540 were weakly involved in putrescine uptake activity. Furthermore, Asp551 was also involved in the recognition of spermidine. These results indicate that the recognition sites for putrescine, agmatine and spermidine on hOCT2 strongly overlap, consistent with the observation that the three amines are transported with similar affinity and velocity. A model of spermidine binding to hOCT2 was constructed based on the functional amino acid residues.

A survey of the kinetic parameters of class C beta-lactamases. Penicillins.

PubMed Central

Galleni, M; Frère, J M

1988-01-01

The interaction between six class C beta-lactamases and various penicillins has been studied. All the enzymes behaved in a very uniform manner. Benzylpenicillin exhibited relatively low kcat. values (14-75 s-1) but low values of Km resulted in high catalytic efficiencies [kcat./Km = 10 X 10(6)-75 X 10(6) M-1.s-1]. The kcat. values for ampicillin were 10-100-fold lower. Carbenicillin, oxacillin cloxacillin and methicillin were very poor substrates, exhibiting kcat. values between 1 x 10(-3) and 0.1 s-1. The Km values were correspondingly small. It could safely be hypothesized that, with all the tested substrates, deacylation was rate-limiting, resulting in acyl-enzyme accumulation. PMID:3264154

Data Build-up for the Construction of Korean Specific Greenhouse Gas Emission Inventory in Livestock Categories.

PubMed

Won, S G; Cho, W S; Lee, J E; Park, K H; Ra, C S

2014-03-01

Many studies on methane (CH4) and nitrous oxide (N2O) emissions from livestock industries have revealed that livestock production directly contributes to greenhouse gas (GHG) emissions through enteric fermentation and manure management, which causes negative impacts on animal environment sustainability. In the present study, three essential values for GHG emission were measured; i.e., i) maximum CH4 producing capacity at mesophilic temperature (37°C) from anaerobically stored manure in livestock category (B0,KM, Korean livestock manure for B0), ii) EF3(s) value representing an emission factor for direct N2O emissions from manure management system S in the country, kg N2O-N kg N(-1), at mesophilic (37°C) and thermophilic (55°C) temperatures, and iii) Nex(T) emissions showing annual N excretion for livestock category T, kg N animal(-1) yr(-1), from different livestock manure. Static incubation with and without aeration was performed to obtain the N2O and CH4 emissions from each sample, respectively. Chemical compositions of pre- and post-incubated manure were analyzed. Contents of total solids (% TS) and volatile solid (% VS), and the ratio of carbon to nitrogen (C/N) decrease significantly in all the samples by C-containing biogas generation, whereas moisture content (%) and pH increased after incubation. A big difference of total nitrogen content was not observed in pre- and post-incubation during CH4 and N2O emissions. CH4 emissions (g CH4 kg VS(-1)) from all the three manures (sows, layers and Korean cattle) were different and high C/N ratio resulted in high CH4 emission. Similarly, N2O emission was found to be affected by % VS, pH, and temperature. The B0,KM values for sows, layers, and Korean cattle obtained at 37°C are 0.0579, 0.0006, and 0.0828 m(3) CH4 kg VS(-1), respectively, which are much less than the default values in IPCC guideline (GL) except the value from Korean cattle. For sows and Korean cattle, Nex(T) values of 7.67 and 28.19 kg N yr(-1), respectively, are 2.5 fold less than those values in IPCC GL as well. However, Nex(T) value of layers 0.63 kg N yr(-1) is very similar to the default value of 0.6 kg N yr(-1) in IPCC GLs for National greenhouse gas inventories for countries such as South Korea/Asia. The EF3(s) value obtained at 37°C and 55°C were found to be far less than the default value.

Mean dynamic topography over Peninsular Malaysian seas using multimission satellite altimetry

NASA Astrophysics Data System (ADS)

Abazu, Isaac Chidi; Din, Ami Hassan Md; Omar, Kamaludin Mohd

2017-04-01

The development of satellite altimeters (SALTs) has brought huge benefits, among which is the ability to more adequately sense ocean-surface topography. The radar altimeter database system was used to capture and process ENVISAT, CRYOSAT-2, SARAL, JASON-1, and JASON-2 SALT data of 5 years between 2011 and 2015. The time series of monthly multimission SALT data showed an estimated sea level trend of 1.0, 2.4, 2.4, 3.6, and 12.0 mm/year at Gelang, Port Kelang, Kukup, Cendering, and Keling. The correlation analysis for the selected tide gauge stations produced satisfying results of R-squared with 0.86, 0.89, 0.91, and 0.97 for Cendering, Sedili, Gelang, and Geting, respectively. The ITG-Grace2010s geoid model was used to compute the mean dynamic topography (MDT) and plot to a grid of 0.25 deg for the Malacca Strait and South China Sea of Peninsular Malaysia, with Keling, Port Kelang, Geting, Sedili, and Johor Bahru tide gauge stations having values determined by interpolation to be 1.14, 1.19, 1.26, 1.88, and 2.91 m, respectively. MDT is computed from the SALT with respect to Port Kelang, the north-south sea slope ranges between -0.64 and 0.29 m/50 km and -0.01 and 0.52 m/50 km along the east and west coasts of Peninsular Malaysia, respectively.

Energy cost of swimming of elite long-distance swimmers.

PubMed

Zamparo, P; Bonifazi, M; Faina, M; Milan, A; Sardella, F; Schena, F; Capelli, C

2005-08-01

The aim of this study was: (1) to assess the energy cost of swimming (C(s), kJ km(-1)) in a group of male (n = 5) and female (n = 5) elite swimmers specialised in long-distance competitions; (2) to evaluate the possible effect of a 2-km trial on the absolute value of C(s). C(s) was assessed during three consecutive 400-m trials covered in a 50-m pool at increasing speeds (v1, v2, v3). After these experiments the subjects swam a 2-km trial at the 10-km race speed (v2km) after which the three 400-m trials were repeated at the same speed as before (v5 = v1, v6 = v2, v7 = v3). C(s) was calculated by dividing the net oxygen uptake at steady state VO2ss by the corresponding average speed (v, m s(-1)). VO2ss was estimated by using back extrapolation technique from breath-to-breath VO2 recorded during the first 30 s of recovery after each test. C(s) increased (from 0.69 kJ m(-1) to 1.27 kJ m(-1)) as a function of v (from 1.29 m s(-1) to 1.50 m s(-1)), its values being comparable to those measured in elite short distance swimmers at similar speeds. In both groups of subjects the speed maintained during the 2-km trial (v2km) was on the average only 1.2% faster than of v2 and v6 (P>0.05), whereas C(s) assessed at the end of the 2-km trial (v2km) turned out to be 21 +/- 26% larger than that assessed at v2 and v6 (P<0.05); the average stroke frequency (SF, cycles min(-1)) during the 2-km trial turned to be about 6% (P<0.05) faster than that assessed at v2 and v6. At v5, C(s) turned out to be 19 +/- 9% (P<0.05) and 22 +/- 27% (0.1 < P = 0.05) larger than at v1 in male and female subjects (respectively). SF was significantly faster (P<0.05, in male subjects) and the distance per stroke (Ds = v/SF) significantly shorter (P<0.05) in female subjects at v5 and v6 than at v1 and v2. These data suggest that the increase of C(s) found after the 2-km trial was likely related to a decrease in propelling efficiency, since the latter is related to the distance per stroke.

Radiation-induced polymerization for the immobilization of penicillin acylase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boccu, E.; Carenza, M.; Lora, S.

The immobilization of Escherichia coli penicillin acylase was investigated by radiation-induced polymerization of 2-hydroxyethyl methacrylate at low temperature. A leak-proof composite that does not swell in water was obtained by adding the cross-linking agent trimethylolpropane trimethacrylate to the monomer-aqueous enzyme mixture. Penicillin acylase, which was immobilized with greater than 70% yield, possessed a higher Km value toward the substrate 6-nitro-3-phenylacetamidobenzoic acid than the free enzyme form (Km = 1.7 X 10(-5) and 1 X 10(-5) M, respectively). The structural stability of immobilized penicillin acylase, as assessed by heat, guanidinium chloride, and pH denaturation profiles, was very similar to that ofmore » the free-enzyme form, thus suggesting that penicillin acylase was entrapped in its native state into aqueous free spaces of the polymer matrix.« less

Comparative kinetics and reciprocal inhibition of nitrate and nitrite uptake in roots of uninduced and induced barley (Hordeum vulgare L.) seedlings

NASA Technical Reports Server (NTRS)

Aslam, M.; Travis, R. L.; Huffaker, R. C.

1992-01-01

Nitrate and NO2- transport by roots of 8-day-old uninduced and induced intact barley (Hordeum vulgare L. var CM 72) seedlings were compared to kinetic patterns, reciprocal inhibition of the transport systems, and the effect of the inhibitor, p-hydroxymercuribenzoate. Net uptake of NO3- and NO2- was measured by following the depletion of the ions from the uptake solutions. The roots of uninduced seedlings possessed a low concentration, saturable, low Km, possibly a constitutive uptake system, and a linear system for both NO3- and NO2-. The low Km system followed Michaelis-Menten kinetics and approached saturation between 40 and 100 micromolar, whereas the linear system was detected between 100 and 500 micromolar. In roots of induced seedlings, rates for both NO3- and NO2- uptake followed Michaelis-Menten kinetics and approached saturation at about 200 micromolar. In induced roots, two kinetically identifiable transport systems were resolved for each anion. At the lower substrate concentrations, less than 10 micromolar, the apparent low Kms of NO3- and NO2- uptake were 7 and 9 micromolar, respectively, and were similar to those of the low Km system in uninduced roots. At substrate concentrations between 10 and 200 micromolar, the apparent high Km values of NO3- uptake ranged from 34 to 36 micromolar and of NO2- uptake ranged from 41 to 49 micromolar. A linear system was also found in induced seedlings at concentrations above 500 micromolar. Double reciprocal plots indicated that NO3- and NO2- inhibited the uptake of each other competitively in both uninduced and induced seedlings; however, Ki values showed that NO3- was a more effective inhibitor than NO2-. Nitrate and NO2- transport by both the low and high Km systems were greatly inhibited by p-hydroxymercuribenzoate, whereas the linear system was only slightly inhibited.

The Advective Flux and Temporal Evolution of Aerosols from the Western Pacific Rim as Observed during TRACE-P

NASA Astrophysics Data System (ADS)

Anderson, B. E.; Jordan, C. E.; Grant, W. B.; Browell, E. V.; Hudgins, C. H.; Winstead, E. L.; Thornhill, K. L.

2002-12-01

The 2001, NASA Transport and Chemical Evolution over the Pacific (TRACE-P) experiment was conducted during late winter and early spring, the time of year when eastward transport of dust and pollution from southern and central Asia reaches a maximum. From bases of operation in Hong Kong, Japan, and Hawaii, extensive measurements of trace species concentrations and characteristics were made from aboard a P-3B and DC-8 aircraft as they flew coordinated sampling missions within air masses at varying distances from the Asian coast and at altitudes ranging from near surface to over 12 km. Data recorded aboard the DC-8 included total condensation nuclei (CN) number densities and fractional volatility; aerosol size distributions, composition and optical properties; and multi-wavelength profiles of polarized, aerosol backscatter. Examining these data in light of simultaneous meteorological and chemical species measurements, we have calculated the advective flux and mean values of aerosol mass and physical properties at various locations within the Western Pacific Basin. At distances >100 km offshore, we find that the highest fluxes of sub-micron particles occurred below 2 km in the region downwind of Shanghai. These air masses exhibited CN concentrations approaching 50,000 cm-3 and visible scattering coefficients in excess of 200 Mm-1. For near-shore sampling between 26° and 36°N within this height range, these parameters averaged ~8,000 cm-3 and 130 Mm-, respectively, . As a result of dilution, surface deposition, and precipitation scavenging, these values rapidly diminished during eastward transport so that parcels sampled at low altitudes >1500 km from land typically contained ~1000 cm-3 CN and exhibited scattering coefficients <30 Mm-1. Because of the decreased strength of loss processes and greater atmospheric stability, parcels sampled in the 2- to 7-km height range were more apt to maintain their initial aerosol signatures during long-range transport.

SSS variability inferred from recent SMOS reprocessing at CATDS

NASA Astrophysics Data System (ADS)

Boutin, Jacqueline; Vergely, Jean-Luc; Marchand, Stéphane; Tarot, Stéphane; Hasson, Audrey; Reverdin, Gilles

2017-04-01

The Soil Moisture and Ocean Salinity (SMOS) satellite mission has monitored sea surface salinity (SSS) over the global ocean for over 7 years. In this poster, we present results obtained at the LOCEAN/ACRI-st expertise center using recent CATDS (Centre Aval de Traitement des Données) SMOS RE05 reprocessing., We find that correction for systematic errors and removal of data contaminated by ice and radio frequency interferences in fresh regions (river mouths, high latitudes) has been improved with respect to SMOS CATDS RE04 reprocessing. We analyze SSS variability as observed by SMOS on a wide range of spatial and temporal scales using various statistical indicators such as mean, median, standard deviation, minimum, maximum values and spectral analysis. We compare them with ARGO interpolated fields (In Situ Analysis System fields) at global scale and with ship SSS transects from the GOSUD and ORE SSS data base. This allows us 1) to demonstrate and quantify the improvement of SMOS SSS fields with respect to earlier versions and 2) to study SSS variability, especially at spatial scales between 50km and 600km not well covered globally by in situ network. The complementarity of this information with respect to SMAP (Soil Moisture Active Passive) SSS fields will be discussed.

THE IMPORTANCE OF OBTAINING INFORMATION ON THE SPECIFIC CONTENT OF TISSUE ENZYMES METABOLIZING ORGANOPHOSPHORUS PESTICIDES, PRIOR TO DETERMINE VMAX, KM VALUES FOR USE IN PBPK MODELS

EPA Science Inventory

Physiological pharmacokinetic/pharmacodynamic models require Vmax, Km values for the metabolism of OPs by tissue enzymes. Current literature values cannot be easily used in OP PBPK models (i.e., parathion and chlorpyrifos) because standard methodologies were not used in their ...

THE IMPORTANCE OF OBTAINING INFORMATION ON THE SPECIFIC CONTENT OF TISSUE ENZYMES METABOLIZING ORGANOPHOSPHORUS PESTICIDES, PRIOR TO DETERMINING VMAX, KM VALUES FOR USE IN PBPK MODELS

EPA Science Inventory

Physiological pharmacokinetic\\pharmacodynamic models require Vmax, Km values for the metabolism of OPs by tissue enzymes. Current literature values cannot be easily used in OP PBPK models (i.e., parathion and chlorpyrifos) because standard methodologies were not used in their ...

The structure of Greater Caucasus in scales of sedimentary cover and crust, based on restored structural sections, which were obtained from study of fold-related strain

NASA Astrophysics Data System (ADS)

Yakovlev, Fedor

2015-04-01

Geological setting. Greater Caucasus (GC) belongs to a linear branch of the Alpine belt (Crimea, Caucasus, Kopet-Dag) which is not arc-like as the Alps. The main stripe of the Alpine deformations in GC occupies space about 1000 x 50 km between the Scythian plate and the Transcaucasian massif. Folded structure prevails and it is accompanied by almost total absence of thrust in a hinterland and by limited thrusts in forelands. The Paleozoic basement outcrops only in a northern half of this linear structure, occupying about 1/8 part of GC. Alpine sedimentary cover (J1 - Pg2) has 10-15 km thickness of flysch-like sequences of sands, argillites, limestones. These sediments formed numerous folds of 0.1 - 1.0 km width. Because each fold has information about strain, the existence of so rich material allows to restore geometry of a sedimentary cover from soil to its top. Method. Three regions were studied due based on 24 detailed structural sections of 510 km total actual length. Two kind of isometric objects of different scale were established: domains and structural cells. There were domains as associations of 2-5 folds; sections were split on 505 one. In these domains, three parameters of morphology were measured as elements of strain ellipsoid (ellipse): dip of axial plain, dip of envelope plain, value of shortening as interlimb angle [1, 2, 3]. It was possible to restore actual state of domain to its pre-folded state (from ellipse to circle) by sequence of three kinematic operations: by rotation to horizontal position of envelope plain, by horizontal simple shear to vertical axial plain and by vertical flattening (pure shear). Pre-folded state of whole section is forming by aggregation of pre-folded states of domains. "Structural cells" were formed by aggregation of 5-10 domains in each cell for correct measuring of shortening value in scale of whole sedimentary cover; there were 78 for three regions. "Stratigraphic models" from bottom to top of cover for each cell were found based on famous (outcropped) column and on some interpolations. It allow to find vertical positions (depth) of section lines inside models. Initial thickness of cover was reformed to new post-folded thickness and knowledge of section line depth allow to find a depth of cover bottom and virtual heigth position of cover top (uplift amplitude). Results. North-Western Caucasus (NWC) was studied on 250x50 km stripe in 11 sections and 42 cells [1]. Initial thickness of sedimentary cover was 13 km (7.3÷17.3 km). Shortening value for structural cells deviated from small (-10%, 2%) at pericline part to 15-67% and it has 35% in average. Actual depth of basement top (soil of sedimentary cover ) was -13 km (-2.2÷-31.7 km). Three sectors along strike of NWC were found: with central depression at pericline (-19, -23 km), with sinking of south part of structure (-27, -32 km) and with central depression again on East (-25 km). Amplitude of erosion has reasonable distribution on NWC: from small in average at pericline (3 km) to high value at center (15 km) with smaller values on edges of sections. Average value was 8.9 km (+0÷+22.2 km). Chiaur tectonic zone in South Ossetia (ChZ) and two zones in South-Eastern Caucasus - Tfan Zone (TZ) and Shakhdag zone (ShZ) have formed together the other part of Caucasus [3]. Initial and actual depths of sedimentary cover have had close values -15 (-21) km, -10 (-10) km, -13 (-12) km. Southern part of structure (ChZ) has had considerable actual subsidence of basement top (-13.6÷-26.3 km). The shortening values were found as 57% in average for ChZ (with deviations 46÷67%), 55% for TZ (36÷67%), 49% for ShZ (37÷62%). Amplitudes of erosion were calculated as 16 km for ChZ (10÷22), 19 km for TZ (12÷24), 10 km for ShZ (7÷12). On the southern border of GC, depths of basement top were found as -8 km for Trans-Caucasian massif (stable block) and -19 km for adjacent cell of ChZ (GC). It means that: 1) value of shortening of sedimentary cover of ChZ 57% is equal to shortening of basement, 2) regional detachment and thrusts in GC above basement cannot exist. Based on these data, calculation of vertical movements of former Moho (-40 km for beginning of J1) shows that actual position of these rocks may has depth about 110 km [3]. It means that considerable part of crust rocks should became "mantle" in density and this kind of rocks transformation is inescapable condition of folding formation for structure of GC. 1. Yakovlev F.L. // Izvestiya, Physics of the Solid Earth. 2009. 45. 11. 1023-1034. 2. Yakovlev F.L. // Comptes Rendus Geoscience. 2012. 344 (3-4). 125-137. 3. Yakovlev F.L. // Bulletin of "KRAESC". Earth Sciences. 2012. 1 (19). 191-214. (in Russian)

Ecosystem Health Assessment at County-Scale Using the Pressure-State-Response Framework on the Loess Plateau, China.

PubMed

Liu, Delin; Hao, Shilong

2016-12-22

Assessing ecosystem health is helpful to determine reasonable eco-environmental restoration and resource management strategies. Based on a pressure-state-response (PSR) framework, a set of comprehensive indicators including natural, social and economic aspects was proposed and applied for assessing the ecosystem health of Yuanzhou County, Loess Plateau, Ningxia Province, China. The basic data used to calculate the values of the assessment indicators include Landsat TM image and socio-economic data, and remote sensing (RS) and the geographic information system (GIS) were used to process image data. The results showed that the ecosystem health conditions of most townships in Yuanzhou County were at the moderately healthy level, three townships were at the healthy level, and only two townships were at the unhelathy level; the areas (percentage) at the unhealthy, moderately healthy and healthy levels were 443.91 km² (12.66%), 2438.75 km² (69.54%) and 624.50 km² (17.81%), respectively. The results could provide useful information for local residents and the government to take measures to improve the health conditions of their township ecosystem.

Ecosystem Health Assessment at County-Scale Using the Pressure-State-Response Framework on the Loess Plateau, China

PubMed Central

Liu, Delin; Hao, Shilong

2016-01-01

Assessing ecosystem health is helpful to determine reasonable eco-environmental restoration and resource management strategies. Based on a pressure-state-response (PSR) framework, a set of comprehensive indicators including natural, social and economic aspects was proposed and applied for assessing the ecosystem health of Yuanzhou County, Loess Plateau, Ningxia Province, China. The basic data used to calculate the values of the assessment indicators include Landsat TM image and socio-economic data, and remote sensing (RS) and the geographic information system (GIS) were used to process image data. The results showed that the ecosystem health conditions of most townships in Yuanzhou County were at the moderately healthy level, three townships were at the healthy level, and only two townships were at the unhelathy level; the areas (percentage) at the unhealthy, moderately healthy and healthy levels were 443.91 km2 (12.66%), 2438.75 km2 (69.54%) and 624.50 km2 (17.81%), respectively. The results could provide useful information for local residents and the government to take measures to improve the health conditions of their township ecosystem. PMID:28025518

Surface magnetometer experiments - Internal lunar properties

NASA Technical Reports Server (NTRS)

Dyal, P.; Daily, W. D.; Parkin, C. W.

1973-01-01

Magnetic fields have been measured on the lunar surface at the Apollo 12, 14, 15, and 16 landing sites. The remanent field values at these sites are respectively 38, 103 (maximum), 3, and 327 gamma (maximum). Simultaneous magnetic field and solar plasma pressure measurements show that the remanent fields at the Apollo 12 and 16 sites are compressed and that the scale size of the Apollo 16 remanent field is 5 less than or equal to L less than 100 km. The global eddy current fields, induced by magnetic step transients in the solar wind, have been analyzed to calculate an electrical conductivity profile. From nightside data it has been found that deeper than 170 km into the moon, the conductivity rises from .0003 mho/m to .01 mho/m at 1000 km depth. Analysis of dayside transient data using a spherically symmetric two-layer model yields a homogeneous conducting core with a radius equal to 0.9 lunar radius and a conductivity of .001 mho/m, surrounded by a nonconducting shell of thickness equal to 0.1 lunar radius.

Stratospheric aerosols from the Sarychev volcano eruption in the 2009 Arctic summer

NASA Astrophysics Data System (ADS)

Jégou, F.; Berthet, G.; Brogniez, C.; Renard, J.-B.; François, P.; Haywood, J. M.; Jones, A.; Bourgeois, Q.; Lurton, T.; Auriol, F.; Godin-Beekmann, S.; Guimbaud, C.; Krysztofiak, G.; Gaubicher, B.; Chartier, M.; Clarisse, L.; Clerbaux, C.; Balois, J. Y.; Verwaerde, C.

2013-02-01

Aerosols from the Sarychev volcano eruption (Kuril Islands, northeast of Japan) were observed in the Arctic lower stratosphere a few days after the strongest SO2 injection which occurred on 15 and 16 June 2009. From the observations provided by the Infrared Atmospheric Sounding Interferometer (IASI) an estimated 0.9 Tg of sulphur dioxide was injected into the Upper Troposphere and Lower Stratosphere (UTLS). The resultant stratospheric sulphate aerosols were detected by the Optical Spectrograph and Infrared Imaging System (OSIRIS) limb sounder and by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) satellite instruments. By the first week of July the aerosol plume had spread out over the entire Arctic region. The Sarychev-induced stratospheric aerosol over the Kiruna region (north of Sweden) was measured by the Stratospheric and Tropospheric Aerosol Counter (STAC) during eight balloon flights planned in August and September 2009. During this balloon campaign the Micro RADIomètre BALlon (MicroRADIBAL) and the Spectroscopie d'Absorption Lunaire pour l'Observation des Minoritaires Ozone et NOx (SALOMON) remote-sensing instruments also observed these aerosols. Aerosol concentrations returned to near-background levels by spring 2010. The effective radius, the Surface Area Density (SAD), the aerosol extinction, and the total sulphur mass from STAC in situ measurements are enhanced with mean values in the range 0.15-0.21 μm, 5.5-14.7 μm2 cm-3, 5.5-29.5×10-4 km-1, and 4.9-12.6×10-10 kg [S] kg-1 [air], respectively, between 14 km and 18 km. The observed and modelled e-folding time of sulphate aerosols from the Sarychev eruption is around 70-80 days, a value much shorter than the 12-14 months calculated for aerosols from the 1991 eruption of Mt. Pinatubo. The OSIRIS stratospheric Aerosol Optical Depth (AOD) at 750 nm is enhanced by a factor of 6 with a value of 0.02 in late July compared to 0.0035 before the eruption. The HadGEM2 and MIMOSA model outputs indicate that aerosol layers in polar region up to 14-15 km are largely modulated by stratosphere-troposphere exchange processes. The spatial extension of the Sarychev plume is well represented in the HadGEM2 model with lower altitudes of the plume being controlled by upper tropospheric troughs which displace the plume downward and upper altitudes around 18-20 km in agreement with lidar observations. A good consistency is found between the HadGEM2 sulphur mass density and the value inferred from the STAC observations with a maximum located about 1 km above the tropopause ranging from 1 to 2×10-9 kg [S] kg-1 [air], which is one order of magnitude higher than the background level.

Response of the low-latitude D region ionosphere to extreme space weather event of 14-16 December 2006

NASA Astrophysics Data System (ADS)

Kumar, Sushil; Kumar, Abhikesh; Menk, Frederick; Maurya, Ajeet K.; Singh, Rajesh; Veenadhari, B.

2015-01-01

response of the D region low-latitude ionosphere has been examined for extreme space weather event of 14-16 December 2006 associated with a X1.5 solar flare and an intense geomagnetic storm (Dst = -146 nT) using VLF signals from Northwest Cape, Australia (NWC) (19.8 kHz) and Lualualei, Hawaii (callsign NPM) (21.4 kHz) transmitters monitored at Suva (Geographic Coordinates, 18.10°S, 178.40°E), Fiji. Modeling of flare associated amplitude and phase enhancements of NWC (3.6 dB, 223°) and NPM (5 dB, 153°) using Long-Wave Propagation Capability code shows reduction in the D region reflection height (H') by 11.1 km and 9.4 km, and enhancement in ionization gradients described by increases in the exponential sharpness factor (β) by 0.122 and 0.126 km-1, for the NWC and NPM paths, respectively. During the storm the daytime signal strengths of the NWC and NPM signals were reduced by 3.2 dB on 15 and 16 December (for about 46 h) and recovered by 17 December. Modeling for the NWC path shows that storm time values of H' and β were reduced by 1.2 km and 0.06 km-1, respectively. Morlet wavelet analysis of signal amplitudes shows no clearly strong signatures of gravity wave propagation to low latitudes during the main and recovery phases. The reduction in VLF signal strength is due to increased signal attenuation and absorption by the Earth-ionosphere waveguide due to storm-induced D region ionization changes and hence changes in D region parameters. The long duration of the storm effect results from the slow diffusion of changed composition/ionization at D region altitudes compared with higher altitudes in the ionosphere.

Systematic Heat Flow Measurements Across the Wagner Basin, Northern Gulf of California

NASA Astrophysics Data System (ADS)

Neumann, F.; Negrete-Aranda, R.; Harris, R. N.; Contreras, J.; Sclater, J. G.; Gonzalez-Fernandez, A.

2017-12-01

A primary control on the geodynamics of rifting is the thermal regime. To better understand the geodynamics of rifting in the northern Gulf of California we systematically measured heat-flow across the Wagner Basin, a tectonically active basin that lies near the southern terminus of the Cerro Prieto fault. Seismic reflection profiles show sediment in excess of 5 s two-way travel time, implying a sediment thickness of > 7 km. The heat flow profile is 40 km long, has a nominal measurement spacing of 1 km, and is collocated with a seismic reflection profile. Heat flow measurements were made with a 6.5-m violin-bow probe. Most measurements are of good quality in that the probe fully penetrated sediments and measurements were stable enough to invert for heat flow and thermal properties. We have estimated corrections for environmental perturbations due to changes in bottom water temperature and sedimentation. The mean and standard deviation of heat flow across the western, central, and eastern parts of the basin are 220±60, 99±14, 1058±519 mW m-2, respectively. Corrections for sedimentation would increase measured heat flow across the central part of basin by 40 to 60%. We interpret the relatively high heat flow and large variability on the western and eastern flanks in terms of upward fluid flow at depth below the seafloor, whereas the lower and more consistent values across the central part of the basin are suggestive of conductive heat transfer. Based on an observed fault depth of 1.75 km we estimated the maximum Darcy velocities through the western and eastern flanks as 3 and 10 cm yr-1, respectively. Heat flow across the central basin is consistent with gabbroic underplating at a depth of 15 km and suggests that continental rupture here has not gone to completion.

Effects of Elastoplastic Material Properties on Shallow Fault Slip and Surface Displacement Fields

NASA Astrophysics Data System (ADS)

Nevitt, J. M.; Brooks, B. A.; Minson, S. E.; Lockner, D. A.; Moore, D. E.; Ericksen, T. L.; Hudnut, K. W.; Glennie, C. L.; Madugo, C. M.

2016-12-01

A primary control on the geodynamics of rifting is the thermal regime. To better understand the geodynamics of rifting in the northern Gulf of California we systematically measured heat-flow across the Wagner Basin, a tectonically active basin that lies near the southern terminus of the Cerro Prieto fault. Seismic reflection profiles show sediment in excess of 5 s two-way travel time, implying a sediment thickness of > 7 km. The heat flow profile is 40 km long, has a nominal measurement spacing of 1 km, and is collocated with a seismic reflection profile. Heat flow measurements were made with a 6.5-m violin-bow probe. Most measurements are of good quality in that the probe fully penetrated sediments and measurements were stable enough to invert for heat flow and thermal properties. We have estimated corrections for environmental perturbations due to changes in bottom water temperature and sedimentation. The mean and standard deviation of heat flow across the western, central, and eastern parts of the basin are 220±60, 99±14, 1058±519 mW m-2, respectively. Corrections for sedimentation would increase measured heat flow across the central part of basin by 40 to 60%. We interpret the relatively high heat flow and large variability on the western and eastern flanks in terms of upward fluid flow at depth below the seafloor, whereas the lower and more consistent values across the central part of the basin are suggestive of conductive heat transfer. Based on an observed fault depth of 1.75 km we estimated the maximum Darcy velocities through the western and eastern flanks as 3 and 10 cm yr-1, respectively. Heat flow across the central basin is consistent with gabbroic underplating at a depth of 15 km and suggests that continental rupture here has not gone to completion.

Model study of atmospheric transport using carbon 14 and strontium 90 as inert tracers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinnison, D.E.; Johnston, H.S.; Wuebbles, D.J.

1994-10-01

The observed excess carbon 14 in the atmosphere from 1963 to 1970 provides unique, but limited, data up to an altitude of about 35 km for testing the air motions calculated by 11 multidimensional atmospheric models. Strontium 90 measurements in the atmosphere from 1964 to mid-1967 provide data that have more latitude coverage than those of carbon 14 and are useful for testing combined models of air motions and aerosol settling. Model calculations for carbon 14 begin at October 1963, 9 months after the conclusion of the nuclear bomb tests; the initial conditions for the calculations are derived by threemore » methods, each of which agrees fairly well with measured carbon 14 in October 1963 and each of which has widely different values in regions of the stratosphere where there were no carbon 14 measurements. The model results are compared to the stratospheric measurements, not as if the observed data were absolute standards, but in an effort to obtain new insight about the models and about the atmosphere. The measured carbon 14 vertical profiles at 31 deg N are qualitatively different from all of the models; the measured vertical profiles show a maximum mixing ratio in the altitude range of 20 to 25 km from October 1963 through July 1966, but all modeled profiles show mixing ratio maxima that increase in altitude from 20 km in October 1963 to greater than 40 km by April 1966. Both carbon 14 and strontium 90 data indicate that the models differ substantially among themselves with respect to stratosphere-troposphere exchange rate, but the modeled carbon 14 stratospheric residence times indicate that differences among the models are small with respect to transport rate between the middle stratosphere and the lower stratosphere. Strontium 90 data indicate that aerosol settling is important up to at least 35 km altitude. (Abstract Truncated)« less

3D lithospheric mapping of the Iberian Peninsula and surrounding Atlantic and Mediterranean margins from 3D joint inversion of potential field and elevation data.

NASA Astrophysics Data System (ADS)

Torne, Montserrat; Zeyen, Hermann; Jimenez-Munt, Ivone; Fernandez, Manel; Vergés, Jaume

2017-04-01

We investigate the lithospheric density structure of the Iberian Peninsula and the surrounding Atlantic and Mediterranean margins from a 3D joint inversion of free-air, geoid and elevation data, based on a Bayesian approach. In addition, the crustal structure has been further constrained by incorporating about 750 Moho values from DSS investigations and RF analysis covering the entire region. Our preliminary results shows a significant lithospheric deformation along the plate boundaries, the Bay of Biscay-Pyrenees to the North and the Azores-Gibraltar to the south, where the CMB and LAB are located at depths more than 45 and 150 km, respectively. Noteworthy is the arcuate lithospheric thickening located at the westernmost end of the Gibraltar Arc system showing the presence of the NW-to-Westward retreated Gibraltar Arc slab that has given rise to the formation of the Betics-Rif Alpine belt system and the back arc Alboran basin. To the west, the stable-slightly deformed Iberian massif shows a quasi-flat CMB and LAB topography (30 to 32 km and about 110 km, respectively). The crust and mantle lithosphere thin towards the Mediterranean and Atlantic margins, with the exception of its northern margin where lithospheric thickening extends offshore to the Gulf of Biscay. In the western Mediterranean the SE-Neogene slab retreat has resulted in a significant thinning of the crust and mantle lithosphere. Thin lithosphere is also observed in the Tagus-Horseshoe abyssal plain region where the LAB shallows to less than 90 km. This work has been funded by the Spanish projects MITE (CGL2014-59516-P) and WEME-CSIC project 201330E11.

Orbital Solution for the Spectroscopic Binary in the GW Ori Hierarchical Triple

NASA Astrophysics Data System (ADS)

Prato, L.; Ruíz-Rodríguez, Dary; Wasserman, L. H.

2018-01-01

We present the first double-lined orbital solution for the close binary in the GW Ori triple system. Using 12 epochs of infrared spectroscopy, we detected the lines of both stars in the inner pair, previously known as single-lined only. Our preliminary infrared orbital solution has an eccentricity of e = 0.21 ± 0.10, a period of P = 241.15 ± 0.72 days, and a mass ratio of q = 0.66 ± 0.13. We find a larger semi-amplitude for the primary star, K1 = 6.57 ± 1.00 km s‑1, with an infrared-only solution compared to K1 = 4.41 ± 0.33 km s‑1 with optical data from the literature, likely the result of line blending and veiling in the optical. The component spectral types correspond to G3 and K0 stars, with v\\sin i values of 43 km s‑1 and 50 km s‑1, respectively. We obtained a flux ratio of α = 0.58 ± 0.14 in the H-band, allowing us to estimate individual masses of 3.2 and 2.7 M ⊙ for the primary and secondary, respectively, using evolutionary tracks. The tracks also yield a coeval age of 1 Myr for both components to within 1σ. GW Ori is surrounded by a circumbinary/circumtriple disk. A tertiary component has been detected in previous studies; however, we did not detect this component in our near-infrared spectra, probably the result of its relative faintness and blending in the absorption lines of these rapidly rotating stars. With these results, GW Ori joins the small number of classical T Tauri, double-lined spectroscopic binaries.

Effect of convection on the thermal structure of the troposphere and lower stratosphere including the tropical tropopause layer in the South Asian monsoon region

NASA Astrophysics Data System (ADS)

Muhsin, M.; Sunilkumar, S. V.; Venkat Ratnam, M.; Parameswaran, K.; Krishna Murthy, B. V.; Emmanuel, Maria

2018-04-01

Influence of convection on the thermal structure of Troposphere and Lower Stratosphere (TLS) is investigated using radiosonde data, obtained from Trivandrum (8.5°N, 76.9°E), Gadanki (13.5°N, 79.2°E), Bhubaneswar (20.25°N, 85.83°E), Kolkata (22.65°N, 88.45°E) and Singapore (1.37°N, 103.98°E), collected during different convective categories classified based on the altitude of deep convective cloud tops (CT) in the period 2008-2014. During deep convective events, the temperature showed lower tropospheric cooling, an upper tropospheric warming and an anomalous cooling (warming) below (above) the cold point tropopause (CPT) with respect to the clear-sky value. While warming in the upper troposphere is strongest (∼2-4 K) around 10-12 km, anomalous cooling (warming) below (above) the CPT is maximum around 15.5 km (17.5 km) with values in the range of-2 to -4 K (3-6 K). These temperature perturbations are observed 5-6 days prior to the convective events. In response to deep convection, surface cooling up to ∼ -4 K is also observed. This study showed that the magnitude of cold and warm anomalies increases with strength of convection. During deep convection, the potential temperature (θ) shows a decrease (<5 K) in the tropical tropopause layer (TTL) from the TTL-base up to CPT compared to that on clear-sky days, confirming the vertical mixing of convective air from the lower atmosphere to the TTL-levels. Correlation analysis between different TTL parameters suggests that, as the cloud top altitude increases, along with the adiabatic process, diabatic process also plays a major role in the TTL. An interesting feature observed during deep convection is the ascent of TTL-base by ∼1.5 km and descent of CPT and TTL-top by 0.5 km, which effectively thins the TTL by ∼2 km.

THE ION-TRAP RESULTS IN "EXPLORATION OF THE UPPER ATMOSPHERE WITH THE HELP OF THE THIRD SOVIET SPUTNIK"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whipple, E.C. Jr.

1961-01-01

In interpreting the ion-trap data obtained from Sputnik III, unexpectedly high electron temperatures were computed by Krassovskii. It was concluded, on the basis of experimental current-voltage characteristics of the collector, that the effective electron temperature at an altitude of 795 km was not less than 15,000 deg K, corresponding to a vehicle potential of -6.4 volts with respect to the plasma. lf, however, it is noted that a retarding potential corresponding to the average kinetic energy will stop only about half the incident ions, new values of 8800 deg K and -3.9 volts, respectively, are obtained. (auth)

Oxygen isotope heterogeneity and disequilibria of olivine crystals in large volume Holocene basalts from Iceland: Evidence for magmatic digestion and erosion of Pleistocene hyaloclastites

NASA Astrophysics Data System (ADS)

Bindeman, Ilya; Gurenko, Andrey; Sigmarsson, Olgeir; Chaussidon, Marc

2008-09-01

This work considers petrogenesis of the largest Holocene basaltic fissure eruptions of Iceland, which are also the largest in the world: Laki (1783-84 AD, 15 km 3), Eldgjá (934 AD, 18 km 3), Veidivötn (900, 1480 AD, multiple eruptions, >2 km 3), Núpahraun (ca. 4000 BP, >1 km 3) and Thjórsárhraun (ca 8000 BP, >20 km 3). We present oxygen isotope laser fluorination analyses of 55 individual and bulk olivine crystals, coexisting individual and bulk plagioclase phenocrysts, and their host basaltic glasses with average precision of better than 0.1‰ (1SD). We also report O isotope analyses of cores and rims of 61 olivine crystals by SIMS with average precision on single spots of 0.24‰ (1SD) in 13 samples coupled with electron microprobe data for major and trace elements in these olivines. Within each individual sample, we have found that basaltic glass is relatively homogeneous with respect to oxygen isotopes, plagioclase phenocrysts exhibit crystal to crystal variability, while individual olivines span from the values in equilibrium with the low-δ 18O matrix glass to those being three permil higher in δ 18O than the equilibrium. Olivine cores with maximum value of 5.2‰ are found in many of these basalts and suggest that the initial magma was equilibrated with normal-δ 18O mantle. No olivines or their intracrystalline domains are found with bulk or spot value higher than those found in MORB olivines. The δ 18O variability of 0.3-3‰ exists for olivine grains from different lavas, and variable core-to-rim oxygen isotopic zoning is present in selected olivine grains. Many olivines in the same sample are not zoned, while a few grains are zoned with respect to oxygen isotopes and exhibit small core-to-core variations in Fe-Mg, Ni, Mn, Ca. Grains that are zoned in both Mg# and δ 18O exhibit positive correlation of these two parameters. Electron microprobe analysis shows that most olivines equilibrated with the transporting melt, and thin Fe-richer rim is present around many grains, regardless of the degree of olivine-melt oxygen isotope disequilibrium. The preservation of isotopic and compositional zoning in selected grains, and subtle to severe Δ 18O (melt-olivine) and Δ 18O (plagioclase-olivine) disequilibria suggests rather short crystal residence times of years to centuries. Synglacially-altered upper crustal, tufaceous hyaloclastites of Pleistocene age serve as a viable source for low-δ 18O values in Holocene basalts through assimilation, mechanical and thermal erosion, and devolatilization of stoped blocks. Cumulates formed in response to cooling during assimilation, and xenocrysts derived from hyaloclastites, contribute to the diverse δ 18O crystalline cargo. The magma plumbing systems under each fissure are likely to include a network of interconnected dikes and sills with high magma flow rates that contribute to the efficacy of magmatic erosion of large quantities (10-60% mass) of hyaloclastites required by isotopic mass balance. Olivine diversity and the pervasive lack of phenocryst-melt oxygen isotopic equilibrium suggest that a common approach of analyzing bulk olivine for oxygen isotopes, as a proxy for the basaltic melt or to infer mantle δ 18O value, needs to proceed with caution. The best approach is to analyze olivine crystals individually and demonstrate their equilibrium with matrix.

NADP(+)-dependent D-xylose dehydrogenase from pig liver. Purification and properties.

PubMed

Zepeda, S; Monasterio, O; Ureta, T

1990-03-15

An NADP(+)-dependent D-xylose dehydrogenase from pig liver cytosol was purified about 2000-fold to apparent homogeneity with a yield of 15% and specific activity of 6 units/mg of protein. An Mr value of 62,000 was obtained by gel filtration. PAGE in the presence of SDS gave an Mr value of 32,000, suggesting that the native enzyme is a dimer of similar or identical subunits. D-Xylose, D-ribose, L-arabinose, 2-deoxy-D-glucose, D-glucose and D-mannose were substrates in the presence of NADP+ but the specificity constant (ratio kcat./Km(app.)) is, by far, much higher for D-xylose than for the other sugars. The enzyme is specific for NADP+; NAD+ is not reduced in the presence of D-xylose or other sugars. Initial-velocity studies for the forward direction with xylose or NADP+ concentrations varied at fixed concentrations of the nucleotide or the sugar respectively revealed a pattern of parallel lines in double-reciprocal plots. Km values for D-xylose and NADP+ were 8.8 mM and 0.99 mM respectively. Dead-end inhibition studies to confirm a ping-pong mechanism showed that NAD+ acted as an uncompetitive inhibitor versus NADP+ (Ki 5.8 mM) and as a competitive inhibitor versus xylose. D-Lyxose was a competitive inhibitor versus xylose and uncompetitive versus NADP+. These results fit better to a sequential compulsory ordered mechanism with NADP+ as the first substrate, but a ping-pong mechanism with xylose as the first substrate has not been ruled out. The presence of D-xylose dehydrogenase suggests that in mammalian liver D-xylose is utilized by a pathway other than the pentose phosphate pathway.

Identification, purification and characterization of furfural transforming enzymes from Clostridium beijerinckii NCIMB 8052.

PubMed

Zhang, Yan; Ujor, Victor; Wick, Macdonald; Ezeji, Thaddeus Chukwuemeka

2015-06-01

Generation of microbial inhibitory compounds such as furfural and 5-hydroxymethylfurfural (HMF) is a formidable roadblock to fermentation of lignocellulose-derived sugars to butanol. Bioabatement offers a cost effective strategy to circumvent this challenge. Although Clostridium beijerinckii NCIMB 8052 can transform 2-3 g/L of furfural and HMF to their less toxic alcohols, higher concentrations present in biomass hydrolysates are intractable to microbial transformation. To delineate the mechanism by which C. beijerinckii detoxifies furfural and HMF, an aldo/keto reductase (AKR) and a short-chain dehydrogenase/reductase (SDR) found to be over-expressed in furfural-challenged cultures of C. beijerinckii were cloned and over-expressed in Escherichia coli Rosetta-gami™ B(DE3)pLysS, and purified by histidine tag-assisted immobilized metal affinity chromatography. Protein gel analysis showed that the molecular weights of purified AKR and SDR are close to the predicted values of 37 kDa and 27 kDa, respectively. While AKR has apparent Km and Vmax values of 32.4 mM and 254.2 mM s(-1) respectively, using furfural as substrate, SDR showed lower Km (26.4 mM) and Vmax (22.6 mM s(-1)) values on the same substrate. However, AKR showed 7.1-fold higher specific activity on furfural than SDR. Further, both AKR and SDR were found to be active on HMF, benzaldehyde, and butyraldehyde. Both enzymes require NADPH as a cofactor for aldehydes reduction. Based on these results, it is proposed that AKR and SDR are involved in the biotransformation of furfural and HMF by C. beijerinckii. Copyright © 2015 Elsevier Ltd. All rights reserved.

Estimation of ground motion parameters

USGS Publications Warehouse

Boore, David M.; Joyner, W.B.; Oliver, A.A.; Page, R.A.

1978-01-01

Strong motion data from western North America for earthquakes of magnitude greater than 5 are examined to provide the basis for estimating peak acceleration, velocity, displacement, and duration as a function of distance for three magnitude classes. A subset of the data (from the San Fernando earthquake) is used to assess the effects of structural size and of geologic site conditions on peak motions recorded at the base of structures. Small but statistically significant differences are observed in peak values of horizontal acceleration, velocity and displacement recorded on soil at the base of small structures compared with values recorded at the base of large structures. The peak acceleration tends to b3e less and the peak velocity and displacement tend to be greater on the average at the base of large structures than at the base of small structures. In the distance range used in the regression analysis (15-100 km) the values of peak horizontal acceleration recorded at soil sites in the San Fernando earthquake are not significantly different from the values recorded at rock sites, but values of peak horizontal velocity and displacement are significantly greater at soil sites than at rock sites. Some consideration is given to the prediction of ground motions at close distances where there are insufficient recorded data points. As might be expected from the lack of data, published relations for predicting peak horizontal acceleration give widely divergent estimates at close distances (three well known relations predict accelerations between 0.33 g to slightly over 1 g at a distance of 5 km from a magnitude 6.5 earthquake). After considering the physics of the faulting process, the few available data close to faults, and the modifying effects of surface topography, at the present time it would be difficult to accept estimates less than about 0.8 g, 110 cm/s, and 40 cm, respectively, for the mean values of peak acceleration, velocity, and displacement at rock sites within 5 km of fault rupture in a magnitude 6.5 earthquake. These estimates can be expected to change as more data become available.

Nd-isotopes in selected mantle-derived rocks and minerals and their implications for mantle evolution

USGS Publications Warehouse

Basu, A.R.; Tatsumoto, M.

1980-01-01

The Sm-Nd systematics in a variety of mantle-derived samples including kimberlites, alnoite, carbonatite, pyroxene and amphibole inclusions in alkali basalts and xenolithic eclogites, granulites and a pyroxene megacryst in kimberlites are reported. The additional data on kimberlites strengthen our earlier conclusion that kimberlites are derived from a relatively undifferentiated chondritic mantle source. This conclusion is based on the observation that the e{open}Nd values of most of the kimberlites are near zero. In contrast with the kimberlites, their garnet lherzolite inclusions show both time-averaged Nd enrichment and depletion with respect to Sm. Separated clinopyroxenes in eclogite xenoliths from the Roberts Victor kimberlite pipe show both positive and negative e{open}Nd values suggesting different genetic history. A whole rock lower crustal scapolite granulite xenolith from the Matsoku kimberlite pipe shows a negative e{open}Nd value of -4.2, possibly representative of the base of the crust in Lesotho. It appears that all inclusions, mafic and ultramafic, in kimberlites are unrelated to their kimberlite host. The above data and additional Sm-Nd data on xenoliths in alkali basalts, alpine peridotite and alnoite-carbonatites are used to construct a model for the upper 200 km of the earth's mantle - both oceanic and continental. The essential feature of this model is the increasing degree of fertility of the mantle with depth. The kimberlite's source at depths below 200 km in the subcontinental mantle is the most primitive in this model, and this primitive layer is also extended to the suboceanic mantle. However, it is clear from the Nd-isotopic data in the xenoliths of the continental kimberlites that above 200 km the continental mantle is distinctly different from their suboceanic counterpart. ?? 1980 Springer-Verlag.

[Values of marine ecosystem services in Sanggou Bay].

PubMed

Zhang, Zhao-hui; Lü, Ji-bin; Ye, Shu-feng; Zhu, Ming-yuan

2007-11-01

A valuation study was conducted in Sanggou Bay, a typical and intensive coastal aquaculture area in China Yellow Sea. The results showed that the total value of ecosystem services (VES) in Sanggou Bay was 6.07 x 10(8) Yen in 2003, with an average unit VES being 4.24 x 10(6) Yen x km(-2). Within the total VES, the provision services, regulation services, and culture services accounted for 51.29%, 17.34%, and 31.37%, respectively. Among the eight primary and secondary services valuated in Sanggou Bay, food provision services held the highest value (50.45%), followed by tourism and entertainment services (29.89%) and climate regulation services (9.18%). Harmful organism and disease control services have the lowest value (0.0017%). The aquaculture activities had greater contributions to the local social economy, environmental regulation, and social culture. Aquaculture activities, especially macro-algae farming, are of significance in maintaining and enhancing the ecosystem services.

Complex N-S variations in Moho depth and Vp/Vs ratio beneath the western Tibetan Plateau as revealed by receiver function analysis

NASA Astrophysics Data System (ADS)

Murodov, Davlatkhudzha; Zhao, Junmeng; Xu, Qiang; Liu, Hongbing; Pei, Shunping

2018-04-01

We present herein detailed images of the Moho depth and Vp/Vs ratio along ANTILOPE-1 profile beneath the western Tibetan Plateau derived from receiver function analysis. Along the ANTILOPE -1 profile, a rapidly northward dipping Moho extends from ˜50 km below the Himalaya to ˜80 km across the Indus-Yarlung suture (IYS), shallowing to ˜66 km under the central Lhasa terrane. The Moho depth shows a dramatic increase from ˜66 km north of the Bangong-Nujiang suture (BNS) to ˜93 km beneath central Qiangtang terrane where it reaches the maximum depth observed along this profile before steeply rising to ˜73 km. We interpret both the 15 km and 20 km offsets of Moho depth occurring beneath the central Lhasa and central Qiangtang terranes as being related to the northern frontiers of the decoupled underthrusting Indian lower crust and lithospheric mantle, respectively. The Moho remains at a depth of ˜70 km with a slight undulation beneath the northern Qiangtang and Songpan-Ganzi terranes, and then abruptly shallows to ˜45 km near the Altyn Tagh Fault. The ˜25 km Moho offset observed at the conjunction of the Tarim Basin and the Altyn Tagh mountain range suggests that the crustal shortening is achieved by pure shear thickening without much underthrusting. The average crustal Vp/Vs ratio changes from 1.66 to 1.80 beneath the Himalaya, the Lhasa terrane and the Tarim Basin indicating a felsic-to-intermediate composition. However, higher Vp/Vs ratios between 1.76 and 1.83 (except for a few outlying low values) are found beneath the Qiangtang and Songpan-Ganzi terranes, which could be attributed to the joint effects of the more mafic composition and partial melt within the crust. The Moho depth and Vp/Vs ratio exhibit complex N-S variations along this profile, which can be attributed to the joint effects of Indian lower crust underthrusting, the low velocity zone of the mid-upper crust, crustal shortening and thickening and other involved dynamic mechanisms.

Herbal Supplement in a Buffer for Dry Eye Syndrome Treatment.

PubMed

Chen, Hung-Chang; Chen, Zhi-Yu; Wang, Tsung-Jen; Drew, Victor J; Tseng, Ching-Li; Fang, Hsu-Wei; Lin, Feng-Huei

2017-08-03

Dry eye syndrome (DES) is one of the most common types of ocular diseases. There is a major need to treat DES in a simple yet efficient way. Artificial tears (AT) are the most commonly used agents for treating DES, but are not very effective. Herbal extractions of ferulic acid (FA), an anti-oxidant agent, and kaempferol (KM), an anti-inflammatory reagent, were added to buffer solution (BS) to replace ATs for DES treatment. The cytotoxicity and anti-inflammatory effects were examined in vitro by co-culture with human corneal epithelial cells (HCECs) to obtain the optimal concentration of KM and FA for treating HCECs. Physical properties of BS, such as pH value, osmolality, and refractive index were also examined. Then, rabbits with DES were used for therapeutic evaluation. Tear production, corneal damage, and ocular irritation in rabbits' eyes were examined. The non-toxic concentrations of KM and FA for HCEC cultivation over 3 days were 1 µM and 100 µM, respectively. Live/dead stain results also show non-toxicity of KM and FA for treating HCECs. Lipopolysaccharide-stimulated HCECs in inflammatory conditions treated with 100 µM FA and 1 µM KM (FA100/KM1) showed lower IL-1B , IL-6 , IL-8 , and TNFα expression when examined by real-time PCR. The BS with FA100/KM1 had neutral pH, and a similar osmolality and refractive index to human tears. Topical delivery of BS + FA100/KM1 showed no irritation to rabbit eyes. The corneal thickness in the BS + FA100/KM1 treated group was comparable to normal eyes. Results of DES rabbits treated with BS + FA100/KM1 showed less corneal epithelial damage and higher tear volume than the normal group. In conclusion, we showed that the combination of FA (100 µM) and KM (1 µM) towards treating inflamed HCECs had an anti-inflammatory effect, and it is effective in treating DES rabbits when BS is added in combination with these two herbal supplements and used as a topical eye drop.

Investigation of surfactant/cosurfactant synergism impact on ibuprofen solubilization capacity and drug release characteristics of nonionic microemulsions.

PubMed

Djekic, Ljiljana; Primorac, Marija; Filipic, Slavica; Agbaba, Danica

2012-08-20

The current study investigates the performances of the multicomponent mixtures of nonionic surfactants regarding the microemulsion stabilisation, drug solubilization and in vitro drug release kinetic. The primary surfactant was PEG-8 caprylic/capric glycerides (Labrasol). The cosurfactants were commercially available mixtures of octoxynol-12 and polysorbate 20 without or with the addition of PEG-40 hydrogenated castor oil (Solubilisant gamma 2421 and Solubilisant gamma 2429, respectively). The oil phase of microemulsions was isopropyl myristate. Phase behaviour study of the pseudo-ternary systems Labrasol/cosurfactant/oil/water at surfactant-to-cosurfactant weight ratios (K(m)) 40:60, 50:50 and 60:40, revealed a strong synergism in the investigated tensides mixtures for stabilisation of microemulsions containing up to 80% (w/w) of water phase at surfactant +cosurfactant-to-oil weight ratio (SCoS/O) 90:10. Solubilization of a model drug ibuprofen in concentration common for topical application (5%, w/w) was achieved at the water contents below 50% (w/w). Drug free and ibuprofen-loaded microemulsions M1-M6, containing 45% (w/w) of water phase, were prepared and characterized by polarized light microscopy, conductivity, pH, rheological and droplet size measurements. In vitro ibuprofen release kinetics from the microemulsions was investigated using paddle-over-enhancer cell method and compared with the commercial 5% (w/w) ibuprofen hydrogel product (Deep Relief, Mentholatum Company Ltd., USA). The investigated microemulsions were isotropic, low viscous Bingham-type liquids with the pH value (4.70-6.61) suitable for topical application. The different efficiency of the tensides mixtures for microemulsion stabilisation was observed, depending on the cosurfactant type and K(m) value. Solubilisant gamma 2429 as well as higher K(m) (i.e., lower relative content of the cosurfactant) provided higher surfactant/cosurfactant synergism. The drug molecules were predominantly solubilized within the interface film. The amount of drug released from the formulations M3 (10.75%, w/w) and M6 (13.45%, w/w) (K(m) 60:40) was limited in comparison with the reference (22.22%, w/w) and follows the Higuchi model. Microemulsions M2 and M5 (K(m) 50:50) gave zero order drug release pattern and ∼15% (w/w) ibuprofen released. The release profiles from microemulsions M1 and M4 (K(m) 40:60) did not fit well with the models used for analysis, although the amounts of ibuprofen released (24.47%, w/w) and 17.99% (w/w), respectively) were comparable to that of the reference hydrogel. The drug release mechanism was related with the surfactant/cosurfactant synergism, thus the lower efficiency of the tensides corresponded to the faster drug release. Copyright © 2012 Elsevier B.V. All rights reserved.

Anomalous top layer in the inner core beneath the eastern hemisphere

NASA Astrophysics Data System (ADS)

Yu, W.; Wen, L.; Niu, F.

2003-12-01

Recent studies reported hemispheric variations in seismic velocity and attenuation in the top of the inner core. It, however, remains unclear how the inner core hemisphericity extends deep in the inner core. Here, we analyze PKPbc-PKIKP and PKiKP-PKIKP waveforms collected from the Global Seismographic Network (GSN), regional recordings from the German Regional Seismic Network (GRSN) and Graefenberg (GRF) sampling along the equatorial path (the ray path whose ray angle is larger than 35o from the Earth's rotation axis). The observed global and regional PKPbc-PKIKP differential traveltimes and PKIKP/PKPbc amplitude ratios suggest a simple W2 model (Wen/Niu:2002) in the western hemisphere with a constant velocity gradient of 0.049(km/sec)/100km and a Q value of 600 in the top 400 km of the inner core. In the eastern hemisphere, the data require a change of velocity gradient and Q value at about 235 km below the inner core boundary (ICB). Based on forward modeling, we construct radial velocity and attenuation models in the eastern hemisphere which can explain both the PKiKP-PKIKP and PKPbc-PKIKP observations. The inner core in the eastern hemisphere has a flat velocity gradient extending to about 235 km below the ICB. We test two solutions for the velocity models in the deeper portion of the inner core, with one having a first-order discontinuity at 235 km below the ICB with a velocity jump of 0.07(km/sec) followed by the PREM gradient, and the other having a gradual velocity transition with 0.1(km/sec)/100km gradient extended from 235 km to 375 km below the ICB followed by the PREM gradient. The observed traveltimes exclude the sharp discontinuity velocity model, as it predicts a kink in differential traveltimes at distance of 151o-152o which is not observed in the global and regional datasets. The observed PKIKP/PKPbc amplitude ratios can be best explained by a step function of attenuation with a Q value of 250 at the top 300 km and a Q value of 600 at 300-400 km below the ICB. The top portion of the inner core in the eastern hemisphere is anomalous compared to the rest of the inner core, in having a flat velocity gradient, higher velocities and higher attenuation.

The comparison of BRDF model and validation of MCD43 products by the 2013 Dunhuang Gobi experiments

NASA Astrophysics Data System (ADS)

Li, Yuan; Rong, Zhi-guo; Zhang, Li-jun; Sun, Ling; Xu, Na

2014-11-01

BRDF has numerous applications in on-orbit satellites vicarious calibration. The 2013 Dunhuang Gobi surface directional reflectance measurements experiment were held during Aug. 20 to Aug. 28. In order to match the spatial resolution (0.25-1.25km) of meteorological satellites, 3*3 sample points were selected covering the 10*10km area. All the data were measured during (3 hours before and after) the noon without taking into account the large sun zenith angle because of the lack of the satellite passing through. Totally 9 groups of directional reflectance (DREF) were measured by the use of ASD (350-2500nm), standard reference board and a portable DREF measurement system. At each point, DREF were measured by different observation zenith angle (0, 20, 40 and 60 degree) and azimuth angle (0, 45, 90, 135, 180, 225, 270, 315 and 360 degree) in 30 minutes. Different BRDF models were selected such as Walthall, Sine Walthall, Hapke, Roujean and Ross-Li. The model coefficients were derived corresponding to the observed data. The relative differences (RD) of the models with respect to the measured values were calculated. The accuracy of MCD43 products in the Julian day of 233 and 241 were also validated. Results showed that Ross-Li model had the smallest RD. The RD between the DREF from MCD43 products and the measured values were 10.26%(233) and 8.96% (241)@550nm, respectively.

Comparison of accelerated and conventional corneal collagen cross-linking for progressive keratoconus.

PubMed

Cınar, Yasin; Cingü, Abdullah Kürşat; Türkcü, Fatih Mehmet; Çınar, Tuba; Yüksel, Harun; Özkurt, Zeynep Gürsel; Çaça, Ihsan

2014-09-01

To compare outcomes of accelerated and conventional corneal cross-linking (CXL) for progressive keratoconus (KC). Patients were divided into two groups as the accelerated CXL group and the conventional CXL group. The uncorrected distant visual acuity (UDVA), corrected distant visual acuity (CDVA), refraction and keratometric values were measured preoperatively and postoperatively. The data of the two groups were compared statistically. The mean UDVA and CDVA were better at the six month postoperative when compared with preoperative values in two groups. While change in UDVA and CDVA was statistically significant in the accelerated CXL group (p = 0.035 and p = 0.047, respectively), it did not reach statistical significance in the conventional CXL group (p = 0.184 and p = 0.113, respectively). The decrease in the mean corneal power (Km) and maximum keratometric value (Kmax) were statistically significant in both groups (p = 0.012 and 0.046, respectively in the accelerated CXL group, p = 0.012 and 0.041, respectively, in the conventional CXL group). There was no statistically significant difference in visual and refractive results between the two groups (p > 0.05). Refractive and visual results of the accelerated CXL method and the conventional CXL method for the treatment of KC in short time period were similar. The accelerated CXL method faster and provide high throughput of the patients.

Similarities and Differences in Pacing Patterns in a 161-km and 101-km Ultra-Distance Road Race.

PubMed

Tan, Philip L S; Tan, Frankie H Y; Bosch, Andrew N

2016-08-01

Tan, PLS, Tan, FHY, and Bosch, AN. Similarities and differences in pacing patterns in a 161-km and 101-km ultra-distance road race. J Strength Cond Res 30(8): 2145-2155, 2016-The purpose of this study was to establish and compare the pacing patterns of fast and slow finishers in a tropical ultra-marathon. Data were collected from the Craze Ultra-marathon held on the 22nd and 21st of September in 2012 and 2013, respectively. Finishers of the 161-km (N = 47) and 101-km (N = 120) categories of the race were divided into thirds (groups A-C) by merit of finishing time. Altogether, 17 and 11 split times were recorded for the 161-km and 101-km finishers, respectively, and used to calculate the mean running speed for each distance segment. Running speed for the first segment was normalized to 100, with all subsequent splits adjusted accordingly. Running speed during the last 5 km was calculated against the mean race pace to establish the existence of an end spurt. A reverse J-shaped pacing profile was demonstrated in all groups for both distance categories and only 38% of the finishers executed an end spurt. In the 101-km category, in comparison with groups B and C, group A maintained a significantly more even pace (p = 0.013 and 0.001, respectively) and completed the race at a significantly higher percent of initial starting speed (p = 0.001 and 0.001, respectively). Descriptive data also revealed that the top 5 finishers displayed a "herd-behavior" by staying close to the lead runner in the initial portion of the race. These findings demonstrate that to achieve a more even pace, recreational ultra-runners should adopt a patient sustainable starting speed, with less competitive runners setting realistic performance goals whereas competitive runners with a specific time goal to consider running in packs of similar pace.

A possible YORP effect on C and S Main Belt Asteroids

NASA Astrophysics Data System (ADS)

Carbognani, A.

2011-01-01

A rotating frequency analysis in a previous paper, showed that two samples of C and S-type asteroids belonging to the Main Belt, but not to any families, present two different values for the transition diameter to a Maxwellian distribution of the rotation frequency, respectively 48 and 33 km. In this paper, after a more detailed statistical analysis, aiming to verify that the result is physically relevant, we found a better estimate for the transition diameter, respectively D C = 44 ± 2 km and D S = 30 ± 1 km. The ratio between these estimated transition diameters, D C/ D S = 1.5 ± 0.1, can be supported with the help of the YORP (Yarkovsky-O'Keefe-Radzievskii-Paddack) effect, although other physical causes cannot be completely ruled out. In this paper we have derived a simple scaling law for YORP which, taking into account the different average heliocentric distance, the bulk density, the albedo and the asteroid "asymmetry surface factor", has enabled us to reasonably justify the ratio between the diameters transition of C-type and S-type asteroids. The same scaling law can be used to estimate a new ratio between the bulk densities of S and C asteroids samples (giving ρ S/ ρ C ≈ 2.9 ± 0.3), and can explain why the asteroids near the transition diameter have about the same absolute magnitude. For C-type asteroids, using the found density ratio and other estimates of S-type density, it is also possible to estimate an average bulk density equal to 0.9 ± 0.1 g cm -3, a value compatible with icy composition. The suggested explanation for the difference of the transition diameters is a plausible hypothesis, consistent with the data, but it needs to be studied more in depth with further observations.

Ultramarathon trail running comparison of performance-matched men and women.

PubMed

Hoffman, Martin D

2008-09-01

To determine whether women matched with men for age and performance in a 50-km trail ultramarathon performed differently than the men in 80- and 161-km trail ultramarathons. Race results from 1990 to 2007 were examined to identify finishers of the Way Too Cool 50-km Race, the American River 80-km Race, and the 161-km Western States Endurance Run in the same year. Matching of women with men for age (mean difference = 1 yr) and 50-km finish time (mean absolute variation = 1.5%) yielded 86 unique pairs from which 161-km performances were compared. A subset of 39 pairs allowed for comparison of all three races. Mean ages of the men and women were 42-44 yr, and mean +/- SD of 50-km running speed was 152 +/- 20 m x min(-1) for both sexes. Mean +/- SD running speeds for the 80-km race (151 +/- 20 and 150 +/- 22 m x min(-1) for the women and men, respectively) and for the 161-km race (102 +/- 13 and 103 +/- 12 m x min(-1) for the women and men, respectively) were not different between the women and men. Women and men who are matched for 50-km trail running performance also perform similarly in trail runs of 80- and 161-km distances.

Rapid vertical trace gas transport by an isolated midlatitude thunderstorm

NASA Astrophysics Data System (ADS)

Hauf, Thomas; Schulte, Peter; Alheit, Reiner; Schlager, Hans

1995-11-01

During the cloud dynamics and chemistry field experiment CLEOPATRA in the summer of 1992 in southern Germany, the Deutsche Forschungsanstalt für Luft- und Raumfahrt (DLR) (German Aerospace Research Establishment) research aircraft Falcon traversed four times the anvil of a severe, isolated thunderstorm. The first two traverses were at 8 km altitude and close to the anvil cloud base, while the second two traverses were at 10 km. During the 8-km traverse, measured ozone mixing ratios dropped by 13 parts per billion by volume (ppbv) from the ambient cloud free environment to the anvil cloud, while water vapor increased by 0.3 g kg-1. At the 10-km traverses, ozone dropped by 25 ppbv, while water vapor increased by 0.18 g kg-1. Three-dimensional numerical thunderstorm simulations were performed to understand the cause of these changes. The simulations included the transport of two chemical inert tracers. Ozone was assumed to be one of them. The initial ozone profile was composed from an ozone routine sounding and the in situ Falcon measurements prior to the thunderstorm development. The second tracer is typical for a surface released pollutant with a nonzero, constant value in the boundary layer but zero above it. The redistribution of both tracers by the storm is calculated and compared with the observations. For the anvil penetration at 10 km, the calculated difference in ozone mixing ratios is 21 ppbv, while for water vapor an increase of 0.25 g kg-1 was found, in good agreement with the observations. To validate the model results, the radar reflectivity was calculated from simulated fields of cloud water, rain, graupel, hail, and snow and ice crystals and compared with observed values. With respect to maximum reflectivity values and spatial scales, again, excellent agreement was achieved. It is concluded that the rapid transport from the boundary layer directly into the anvil level is the most likely cause of the observed ozone decrease and water vapor increase. Entrainment of ozone-rich environmental air into the anvil cloud occurred but left a protected core with undiluted boundary layer air in the anvil cloud even at a distance of 120 km from the main updraft. Processes such as production of O3 by electrical discharges, chemical reactions of ozone with boundary layer-released or lightning-produced nitrogen compounds, scavenging by hydrometeors, and heterogeneous reactions at the surface of ice crystals may occur, but on the timescale of 0.5-1 hour seem to have a negligible influence on the observed ozone drop.

Nicotinamide riboside, an unusual, non-typical, substrate of purified purine-nucleoside phosphorylases.

PubMed

Wielgus-Kutrowska, B; Kulikowska, E; Wierzchowski, J; Bzowska, A; Shugar, D

1997-01-15

Nicotinamide 1-beta-D-riboside (Nir), the cationic, reducible moiety of the coenzyme NAD+, has been confirmed as an unusual substrate for purified purine-nucleoside phosphorylase (PNP) from a mammalian source (calf spleen). It is also a substrate of the enzyme from Escherichia coli. The Km values at pH 7, 1.48 mM and 0.62 mM, respectively, were 1-2 orders of magnitude higher than for the natural substrate inosine, but the Vmax values were comparable, 96% and 35% that for Ino. The pseudo first-order rate constants, Vmax/Km, were 1.1% and 2.5% for the calf spleen and E. coli enzymes. The aglycon, nicotinamide, was neither a substrate nor an inhibitor of PNP. Nir was a weak inhibitor of inosine phosphorolysis catalyzed by both enzymes, with Ki values close to the Km for its phosphorolysis, consistent with simple competitive inhibition; this was further confirmed by Dixon plots. Phosphorolysis of the fluorescent positively charged substrate 7-methylguanosine was also inhibited in a competitive manner by both Ino and Nir. Phosphorolysis of Nir by both enzymes was inhibited competitively by several specific inhibitors of calf spleen and E. coli PNP, with Ki values similar to those for inhibition of other natural substrates. The pH dependence of the kinetic constants for the phosphorolysis of Nir and of a variety of other substrates, was extensively investigated, particularly in the alkaline pH range, where Nir exhibited abnormally high substrate activity relative to the reduced reaction rates of both enzymes towards other anionic or neutral substrates. The overall results are discussed in relation to present concepts regarding binding and phosphorolysis of substrates by PNP based on crystallographic data of enzyme-inhibitor complexes, and current studies on enzymatic and nonenzymatic mechanisms of the cleavage of the Nir glycosidic bond.

Spatial Distribution of Stony Desertification and Key Influencing Factors on Different Sampling Scales in Small Karst Watersheds

PubMed Central

Zhang, Zhenming; Zhou, Yunchao; Wang, Shijie

2018-01-01

Karst areas are typical ecologically fragile areas, and stony desertification has become the most serious ecological and economic problems in these areas worldwide as well as a source of disasters and poverty. A reasonable sampling scale is of great importance for research on soil science in karst areas. In this paper, the spatial distribution of stony desertification characteristics and its influencing factors in karst areas are studied at different sampling scales using a grid sampling method based on geographic information system (GIS) technology and geo-statistics. The rock exposure obtained through sampling over a 150 m × 150 m grid in the Houzhai River Basin was utilized as the original data, and five grid scales (300 m × 300 m, 450 m × 450 m, 600 m × 600 m, 750 m × 750 m, and 900 m × 900 m) were used as the subsample sets. The results show that the rock exposure does not vary substantially from one sampling scale to another, while the average values of the five subsamples all fluctuate around the average value of the entire set. As the sampling scale increases, the maximum value and the average value of the rock exposure gradually decrease, and there is a gradual increase in the coefficient of variability. At the scale of 150 m × 150 m, the areas of minor stony desertification, medium stony desertification, and major stony desertification in the Houzhai River Basin are 7.81 km2, 4.50 km2, and 1.87 km2, respectively. The spatial variability of stony desertification at small scales is influenced by many factors, and the variability at medium scales is jointly influenced by gradient, rock content, and rock exposure. At large scales, the spatial variability of stony desertification is mainly influenced by soil thickness and rock content. PMID:29652811

Spatial Distribution of Stony Desertification and Key Influencing Factors on Different Sampling Scales in Small Karst Watersheds.

PubMed

Zhang, Zhenming; Zhou, Yunchao; Wang, Shijie; Huang, Xianfei

2018-04-13

Karst areas are typical ecologically fragile areas, and stony desertification has become the most serious ecological and economic problems in these areas worldwide as well as a source of disasters and poverty. A reasonable sampling scale is of great importance for research on soil science in karst areas. In this paper, the spatial distribution of stony desertification characteristics and its influencing factors in karst areas are studied at different sampling scales using a grid sampling method based on geographic information system (GIS) technology and geo-statistics. The rock exposure obtained through sampling over a 150 m × 150 m grid in the Houzhai River Basin was utilized as the original data, and five grid scales (300 m × 300 m, 450 m × 450 m, 600 m × 600 m, 750 m × 750 m, and 900 m × 900 m) were used as the subsample sets. The results show that the rock exposure does not vary substantially from one sampling scale to another, while the average values of the five subsamples all fluctuate around the average value of the entire set. As the sampling scale increases, the maximum value and the average value of the rock exposure gradually decrease, and there is a gradual increase in the coefficient of variability. At the scale of 150 m × 150 m, the areas of minor stony desertification, medium stony desertification, and major stony desertification in the Houzhai River Basin are 7.81 km², 4.50 km², and 1.87 km², respectively. The spatial variability of stony desertification at small scales is influenced by many factors, and the variability at medium scales is jointly influenced by gradient, rock content, and rock exposure. At large scales, the spatial variability of stony desertification is mainly influenced by soil thickness and rock content.

Detection of Coccolithophore Blooms in Ocean Color Satellite Imagery: a Generalized Approach for Use with Multiple Sensors

NASA Technical Reports Server (NTRS)

Moore, Timothy; Dowell, Mark; Franz, Bryan A.

2012-01-01

A generalized coccolithophore bloom classifier has been developed for use with ocean color imagery. The bloom classifier was developed using extracted satellite reflectance data from SeaWiFS images screened by the default bloom detection mask. In the current application, we extend the optical water type (OWT) classification scheme by adding a new coccolithophore bloom class formed from these extracted reflectances. Based on an in situ coccolithophore data set from the North Atlantic, the detection levels with the new scheme were between 1,500 and 1,800 coccolithophore cellsmL and 43,000 and 78,000 lithsmL. The detected bloom area using the OWT method was an average of 1.75 times greater than the default bloom detector based on a collection of SeaWiFS 1 km imagery. The versatility of the scheme is shown with SeaWiFS, MODIS Aqua, CZCS and MERIS imagery at the 1 km scale. The OWT scheme was applied to the daily global SeaWiFS imagery mission data set (years 19972010). Based on our results, average annual coccolithophore bloom area was more than two times greater in the southern hemisphere compared to the northern hemi- sphere with values of 2.00 106 km2 and 0.75 106 km2, respectively. The new algorithm detects larger bloom areas in the Southern Ocean compared to the default algorithm, and our revised global annual average of 2.75106 km2 is dominated by contributions from the Southern Ocean.

Crustal thickness and Vp/Vs beneath the southeastern United States: Constraints from receiver function stacking

NASA Astrophysics Data System (ADS)

Yang, Q.; Gao, S. S.; Liu, K. H.

2017-12-01

To provide new constraints on crustal structure and evolution models beneath a collage of tectonic provinces in the southeastern United States, a total of 10,753 teleseismic receiver functions recorded by 125 USArray and other seismic stations are used to compute crustal thickness and Vp/Vs values. The resulting crustal thicknesses range from 25 km at the coast to 51 km beneath the peak of the southern Appalachians with an average of 36.2 km ± 5.5 km. The resulting crustal thicknesses correlate well with surface elevation and Bouguer gravity anomalies. Beneath the Atlantic Coastal Plain, the crustal thicknesses show a clear eastward thinning with a magnitude of 10 km, from about 40 km beneath the western margin to 30 km beneath the coast. The Vp/Vs values for the entire study area range from 1.71 to 1.90 with a mean value of 1.80 ± 0.04. The mean Vp/Vs value is 1.82±0.035 in the southern Appalachian Mountain. The slightly larger than normal crustal Vp/Vs for this area might be the result of significant erosion of the felsic upper crust over the past 300 million years. Alternatively, it could also suggest the existence of pervasive magmatic intrusion into the Appalachian crust. The Vp/Vs measurements in the Atlantic Coastal Plain increase toward the east, ranging from 1.75 to 1.82, probably indicating a gradual increase of mafic magmatic intrusion into thinner crust during the development of the passive continental margin.

Impact Craters: Size-Dependent Degration Rates

NASA Astrophysics Data System (ADS)

Ravi, S.; Mahanti, P.; Meyer, H. M.; Robinson, M. S.

2017-12-01

From superposition relations, Shoemaker and Hackman (1) devised the lunar geologic timescale with Copernican and Eratosthenian as the most recent periods. Classifying craters into the two periods is key to understanding impactor flux and regolith maturation rates over the last 3 Ga. Both Copernican and Eratosthenian craters exhibit crisp morphologies (sharp rims, steep slopes), however, only the former exhibit high reflectance rays and ejecta (1). Based on the Optical Maturity Parameter (OMAT; 2), Grier et al. (3) classified 50 fresh craters (D >20 km) into 3 categories - young (OMAT >0.22), intermediate, and old (OMAT <0.16). In our previous work, Copernican craters (D > 10) were identified (4) from a catalogue of 11,875 craters (5). In this work; we compare two size ranges (D: 5 km - 10 km and 10 km to 15 km) of 177 Copernican craters based on the average OMAT, measured near the crater rim (3). OMAT is measured at the crater rim (as opposed to further away from the crater) to minimize the influence of spatial variation of OMAT (6) in our investigation. We found that OMAT values are typically lower for smaller craters (5km < D < 10km) in comparison to larger craters (10km < D < 15km). However, when compared against morphological freshness (as determined by d/D for simpler craters), the smaller craters were fresher (higher d/D value). Since the OMAT value decreases with age, craters with higher d/D value (morphologically fresher) should have higher OMAT, but this is not the case. We propose that quicker loss of OMAT (over time) for smaller craters compared to decrease in d/D with crater ageing, is responsible for the observed decreased OMAT for smaller craters. (1) Shoemaker and Hackman, 1962 (2) Lucey et al., 2000 (3) Grier et al., 2001 (4) Ravi et al., 2016 (5) Reinhold et al., 2015 (6) Mahanti et al., 2016

Investigation of tropical cirrus cloud properties using ground based lidar measurements

NASA Astrophysics Data System (ADS)

Dhaman, Reji K.; Satyanarayana, Malladi; Krishnakumar, V.; Mahadevan Pillai, V. P.; Jayeshlal, G. S.; Raghunath, K.; Venkat Ratnam, M.

2016-05-01

Cirrus clouds play a significant role in the Earths radiation budget. Therefore, knowledge of geometrical and optical properties of cirrus cloud is essential for the climate modeling. In this paper, the cirrus clouds microphysical and optical properties are made by using a ground based lidar measurements over an inland tropical station Gadanki (13.5°N, 79.2°E), Andhra Pradesh, India. The variation of cirrus microphysical and optical properties with mid cloud temperature is also studied. The cirrus clouds mean height is generally observed in the range of 9-17km with a peak occurrence at 13- 14km. The cirrus mid cloud temperature ranges from -81°C to -46°C. The cirrus geometrical thickness ranges from 0.9- 4.5km. During the cirrus occurrence days sub-visual, thin and dense cirrus were at 37.5%, 50% and 12.5% respectively. The monthly cirrus optical depth ranges from 0.01-0.47, but most (<80%) of the cirrus have values less than 0.1. Optical depth shows a strong dependence with cirrus geometrical thickness and mid-cloud height. The monthly mean cirrus extinction ranges from 2.8E-06 to 8E-05 and depolarization ratio and lidar ratio varies from 0.13 to 0.77 and 2 to 52 sr respectively. A positive correlation exists for both optical depth and extinction with the mid-cloud temperature. The lidar ratio shows a scattered behavior with mid-cloud temperature.

Preferential inhibition of xanthine oxidase by 2-amino-6-hydroxy-8-mercaptopurine and 2-amino-6-purine thiol

PubMed Central

Kalra, Sukirti; Jena, Gopabandhu; Tikoo, Kulbhushan; Mukhopadhyay, Anup Kumar

2007-01-01

Background The anticancer drug, 6-mercaptopurine (6MP) is subjected to metabolic clearance through xanthine oxidase (XOD) mediated hydroxylation, producing 6-thiouric acid (6TUA), which is excreted in urine. This reduces the effective amount of drug available for therapeutic efficacy. Co-administration of allopurinol, a suicide inhibitor of XOD, which blocks the hydroxylation of 6MP inadvertently enhances the 6MP blood level, counters this reduction. However, allopurinol also blocks the hydroxylation of hypoxanthine, xanthine (released from dead cancer cells) leading to their accumulation in the body causing biochemical complications such as xanthine nephropathy. This necessitates the use of a preferential XOD inhibitor that selectively inhibits 6MP transformation, but leaves xanthine metabolism unaffected. Results Here, we have characterized two such unique inhibitors namely, 2-amino-6-hydroxy-8-mercaptopurine (AHMP) and 2-amino-6-purinethiol (APT) on the basis of IC50 values, residual activity in bi-substrate simulative reaction and the kinetic parameters like Km, Ki, kcat. The IC50 values of AHMP for xanthine and 6MP as substrate are 17.71 ± 0.29 μM and 0.54 ± 0.01 μM, respectively and the IC50 values of APT for xanthine and 6MP as substrates are 16.38 ± 0.21 μM and 2.57 ± 0.08 μM, respectively. The Ki values of XOD using AHMP as inhibitor with xanthine and 6MP as substrate are 5.78 ± 0.48 μM and 0.96 ± 0.01 μM, respectively. The Ki values of XOD using APT as inhibitor with xanthine and 6MP as substrate are 6.61 ± 0.28 μM and 1.30 ± 0.09 μM. The corresponding Km values of XOD using xanthine and 6MP as substrate are 2.65 ± 0.02 μM and 6.01 ± 0.03 μM, respectively. The results suggest that the efficiency of substrate binding to XOD and its subsequent catalytic hydroxylation is much superior for xanthine in comparison to 6MP. In addition, the efficiency of the inhibitor binding to XOD is much more superior when 6MP is the substrate instead of xanthine. We further undertook the toxicological evaluation of these inhibitors in a single dose acute toxicity study in mice and our preliminary experimental results suggested that the inhibitors were equally non-toxic in the tested doses. Conclusion We conclude that administration of either APT or AHMP along with the major anti-leukemic drug 6MP might serve as a good combination cancer chemotherapy regimen. PMID:17511860

Identification of Functional Amino Acid Residues Involved in Polyamine and Agmatine Transport by Human Organic Cation Transporter 2

PubMed Central

Higashi, Kyohei; Imamura, Masataka; Fudo, Satoshi; Uemura, Takeshi; Saiki, Ryotaro; Hoshino, Tyuji; Toida, Toshihiko; Kashiwagi, Keiko; Igarashi, Kazuei

2014-01-01

Polyamine (putrescine, spermidine and spermine) and agmatine uptake by the human organic cation transporter 2 (hOCT2) was studied using HEK293 cells transfected with pCMV6-XL4/hOCT2. The Km values for putrescine and spermidine were 7.50 and 6.76 mM, and the Vmax values were 4.71 and 2.34 nmol/min/mg protein, respectively. Spermine uptake by hOCT2 was not observed at pH 7.4, although it inhibited both putrescine and spermidine uptake. Agmatine was also taken up by hOCT2, with Km value: 3.27 mM and a Vmax value of 3.14 nmol/min/mg protein. Amino acid residues involved in putrescine, agmatine and spermidine uptake by hOCT2 were Asp427, Glu448, Glu456, Asp475, and Glu516. In addition, Glu524 and Glu530 were involved in putrescine and spermidine uptake activity, and Glu528 and Glu540 were weakly involved in putrescine uptake activity. Furthermore, Asp551 was also involved in the recognition of spermidine. These results indicate that the recognition sites for putrescine, agmatine and spermidine on hOCT2 strongly overlap, consistent with the observation that the three amines are transported with similar affinity and velocity. A model of spermidine binding to hOCT2 was constructed based on the functional amino acid residues. PMID:25019617

Informatics and computational method for inundation and land use study in Arctic Sea eastern Siberia, Russia

NASA Astrophysics Data System (ADS)

Boori, Mukesh Singh; Choudhary, Komal; Kupriyanov, Alexander; Sugimoto, Atsuko

2016-11-01

Eastern Siberia, Russia is physically and socio-economically vulnerable to accelerated Arctic sea level rise due to low topography, high ecological value, harsh climatic conditions, erosion and flooding of coastal area and destruction of harbor constructions and natural coastal hazards. A 1 to 10m inundation land loss scenarios for surface water and sea level rise (SLR) were developed using digital elevation models of study site topography through remote sensing and GIS techniques by ASTER GDEM and Landsat OLI data. Results indicate that 10.82% (8072.70km2) and 29.73% (22181.19km2) of the area will be lost by flooding at minimum and maximum inundation levels, respectively. The most severely impacted sectors are expected to be the vegetation, wetland and the natural ecosystem. Improved understanding of the extent and response of SLR will help in preparing for mitigation and adaptation.

Cloning and functional characterization of the high-affinity K+ transporter HAK1 of pepper.

PubMed

Martínez-Cordero, M Angeles; Martínez, Vicente; Rubio, Francisco

2004-10-01

High-affinity K+ uptake in plants plays a crucial role in K+ nutrition and different systems have been postulated to contribute to the high-affinity K+ uptake. The results presented here with pepper (Capsicum annum) demonstrate that a HAK1-type transporter greatly contributes to the high-affinity K+ uptake observed in roots. Pepper plants starved of K+ for 3 d showed high-affinity K+ uptake (Km of 6 microM K+) that was very sensitive to NH and their roots expressed a high-affinity K+ transporter, CaHAK1, which clusters in group I of the KT/HAK/KUP family of transporters. When expressed in yeast ( Saccharomyces cerevisiae ), CaHAK1 mediated high-affinity K+ and Rb+ uptake with Km values of 3.3 and 1.9 microM, respectively. Rb+ uptake was competitively inhibited by micromolar concentrations of NH and Cs+, and by millimolar concentrations of Na+.

Engineering the Substrate Specificity of the DhbE Adenylation Domain by Yeast Cell Surface Display

PubMed Central

Zhang, Keya; Nelson, Kathryn M.; Bhuripanyo, Karan; Grimes, Kimberly D.; Zhao, Bo; Aldrich, Courtney C.; Yin, Jun

2013-01-01

SUMMARY The adenylation (A) domains of nonribosomal peptide synthetases (NRPSs) activate aryl acids or amino acids to launch their transfer through the NRPS assembly line for the biosynthesis of many medicinally important natural products. In order to expand the substrate pool of NRPSs, we developed a method based on yeast cell surface display to engineer the substrate specificities of the A-domains. We acquired A-domain mutants of DhbE that have 11- and 6-fold increases in kcat/Km with nonnative substrates 3-hydroxybenzoic acid and 2-aminobenzoic acid, respectively and corresponding 3- and 33-fold decreases in kcat/Km values with the native substrate 2,3-dihydroxybenzoic acid, resulting in a dramatic switch in substrate specificity of up to 200-fold. Our study demonstrates that yeast display can be used as a high throughput selection platform to reprogram the “nonribosomal code” of A-domains. PMID:23352143

Simulation of strong ground motion parameters of the 1 June 2013 Gulf of Suez earthquake, Egypt

NASA Astrophysics Data System (ADS)

Toni, Mostafa

2017-06-01

This article aims to simulate the ground motion parameters of the moderate magnitude (ML 5.1) June 1, 2013 Gulf of Suez earthquake, which represents the largest instrumental earthquake to be recorded in the middle part of the Gulf of Suez up to now. This event was felt in all cities located on both sides of the Gulf of Suez, with minor damage to property near the epicenter; however, no casualties were observed. The stochastic technique with the site-dependent spectral model is used to simulate the strong ground motion parameters of this earthquake in the cities located at the western side of the Gulf of Suez and north Red Sea namely: Suez, Ain Sokhna, Zafarana, Ras Gharib, and Hurghada. The presence of many tourist resorts and the increase in land use planning in the considered cities represent the motivation of the current study. The simulated parameters comprise the Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV), and Peak Ground Displacement (PGD), in addition to Pseudo Spectral Acceleration (PSA). The model developed for ground motion simulation is validated by using the recordings of three accelerographs installed around the epicenter of the investigated earthquake. Depending on the site effect that has been determined in the investigated areas by using geotechnical data (e.g., shear wave velocities and microtremor recordings), the investigated areas are classified into two zones (A and B). Zone A is characterized by higher site amplification than Zone B. The ground motion parameters are simulated at each zone in the considered areas. The results reveal that the highest values of PGA, PGV, and PGD are observed at Ras Gharib city (epicentral distance ∼ 11 km) as 67 cm/s2, 2.53 cm/s, and 0.45 cm respectively for Zone A, and as 26.5 cm/s2, 1.0 cm/s, and 0.2 cm respectively for Zone B, while the lowest values of PGA, PGV, and PGD are observed at Suez city (epicentral distance ∼ 190 km) as 3.0 cm/s2, 0.2 cm/s, and 0.05 cm/s respectively for Zone A, and as 1.3 cm/s2, 0.1 cm/s, and 0.024 cm respectively for Zone B. Also the highest PSA values are observed in Ras Gharib city as 200 cm/s2 and 78 cm/s2 for Zone A and Zone B respectively, while the lowest PSA values are observed in Suez city as 7 cm/s2 and 3 cm/s2 for Zone A and Zone B respectively. These results show a good agreement with the earthquake magnitude, epicentral distances, and site characterizations as well.

Regional analysis of distribution of pre and post 2015 Nepal Earthquake landslides

NASA Astrophysics Data System (ADS)

Valagussa, Andrea; Frattini, Paolo; Crosta, Giovanni; Valbuzzi, Elena

2016-04-01

A magnitude 7.8 earthquake struck Nepal on April 25, 2015. Three landslide inventories have been prepared in four districts: Dhading (1885 km2), Sindhupalchok (2488 km2), Rasuwa (1522 km2) and Nuwakot (1194 km2), that are located north of Kathmandu. These inventories extend 14 to 138 km SE from the epicenter of the main shock (April 25, 2015), 4.5 to 143 km NW from the epicenter of the main aftershock (May 12, 2015), and 34 to 136 km from the Main Frontal Thrust. The first inventory is a coseismic and post-seismic landslide inventory based on multi-temporal images (Google Earth, Google Crisis maps, Bing maps), and helicopter-based video. The second one is a pre-event shallow landslide inventory. In these two inventories the most abundant landslide types are: debris flows, shallow translational slides, and rockfalls. The third is a deep seated landslide inventory, in which the most represented landslide types are rock avalanches, slumps, rockslides and deep-seated gravitational slope deformations (DSGSD). All the landslides have been mapped as individual polygons. For the analysis we focus our attention on four districts: First we studied how the landslide frequency density changes as a function of topographic parameters (i.e. slope gradient, slope aspect, and elevation). The analyses have been based on the ASTER Global Digital Elevation Model (ASTER GDEM). For coseismic and post-seismic landslides we observed that the mean slope gradient at which the landslide occurs is higher with respect to the two other inventories (50° and 30/40° respectively). The slope aspect of coseismic and post-seismic landslides is also different, with a larger frequency of landslides towards SW, whereas in pre-event landslides the most common slope aspect is SE. This could be related to the direction of the seismic wave. At least the coseismic and post-seismic landslides occur, in mean, at an elevation lower than the pre-event landslides. We also analyzed the relationship between the landslide frequency density and the lithology in which each landslide occurs to better understand if a particular geological suite is more prone to give landslides, both in seismic and non-seismic conditions. The landslide density for the Deep Seated Landslides and the Pre-Event Shallow landslides does not shows particular changes with the lithology in which the landslide occurred. The Deep Seated Landslides seem to be more abundant in marbles with respect the others lithologies. The pre-event landslides seem to be more abundant in gneiss and shale. Different observations could be done for the coseismic and post-seismic landslides, which show a high value of density (5.13 landslides per km2) for schist, limestone and quartzite. Instead, the granites have a lower number of landslides, as observed for the two other inventories.

Evaluation of extreme ionospheric total electron content gradient associated with plasma bubbles for GNSS Ground-Based Augmentation System

NASA Astrophysics Data System (ADS)

Saito, S.; Yoshihara, T.

2017-08-01

Associated with plasma bubbles, extreme spatial gradients in ionospheric total electron content (TEC) were observed on 8 April 2008 at Ishigaki (24.3°N, 124.2°E, +19.6° magnetic latitude), Japan. The largest gradient was 3.38 TECU km-1 (total electron content unit, 1 TECU = 1016 el m-2), which is equivalent to an ionospheric delay gradient of 540 mm km-1 at the GPS L1 frequency (1.57542 GHz). This value is confirmed by using multiple estimating methods. The observed value exceeds the maximum ionospheric gradient that has ever been observed (412 mm km-1 or 2.59 TECU km-1) to be associated with a severe magnetic storm. It also exceeds the assumed maximum value (500 mm km-1 or 3.08 TECU km-1) which was used to validate the draft international standard for Global Navigation Satellite System (GNSS) Ground-Based Augmentation Systems (GBAS) to support Category II/III approaches and landings. The steepest part of this extreme gradient had a scale size of 5.3 km, and the front-normal velocities were estimated to be 71 m s-1 with a wavefront-normal direction of east-northeastward. The total width of the transition region from outside to inside the plasma bubble was estimated to be 35.3 km. The gradient of relatively small spatial scale size may fall between an aircraft and a GBAS ground subsystem and may be undetectable by both aircraft and ground.

Ionization Efficiency in the Dayside Martian Upper Atmosphere

NASA Astrophysics Data System (ADS)

Cui, J.; Wu, X.-S.; Xu, S.-S.; Wang, X.-D.; Wellbrock, A.; Nordheim, T. A.; Cao, Y.-T.; Wang, W.-R.; Sun, W.-Q.; Wu, S.-Q.; Wei, Y.

2018-04-01

Combining the Mars Atmosphere and Volatile Evolution measurements of neutral atmospheric density, solar EUV/X-ray flux, and differential photoelectron intensity made during 240 nominal orbits, we calculate the ionization efficiency, defined as the ratio of the secondary (photoelectron impact) ionization rate to the primary (photon impact) ionization rate, in the dayside Martian upper atmosphere under a range of solar illumination conditions. Both the CO2 and O ionization efficiencies tend to be constant from 160 km up to 250 km, with respective median values of 0.19 ± 0.03 and 0.27 ± 0.04. These values are useful for fast calculation of the ionization rate in the dayside Martian upper atmosphere, without the need to construct photoelectron transport models. No substantial diurnal and solar cycle variations can be identified, except for a marginal trend of reduced ionization efficiency approaching the terminator. These observations are favorably interpreted by a simple scenario with ionization efficiencies, as a first approximation, determined by a comparison between relevant cross sections. Our analysis further reveals a connection between regions with strong crustal magnetic fields and regions with high ionization efficiencies, which are likely indicative of more efficient vertical transport of photoelectrons near magnetic anomalies.

A comparative study of spherical and flat-Earth geopotential modeling at satellite elevations

NASA Technical Reports Server (NTRS)

Parrott, M. H.; Hinze, W. J.; Braile, L. W.; Vonfrese, R. R. B.

1985-01-01

Flat-Earth modeling is a desirable alternative to the complex spherical-Earth modeling process. These methods were compared using 2 1/2 dimensional flat-earth and spherical modeling to compute gravity and scalar magnetic anomalies along profiles perpendicular to the strike of variably dimensioned rectangular prisms at altitudes of 150, 300, and 450 km. Comparison was achieved with percent error computations (spherical-flat/spherical) at critical anomaly points. At the peak gravity anomaly value, errors are less than + or - 5% for all prisms. At 1/2 and 1/10 of the peak, errors are generally less than 10% and 40% respectively, increasing to these values with longer and wider prisms at higher altitudes. For magnetics, the errors at critical anomaly points are less than -10% for all prisms, attaining these magnitudes with longer and wider prisms at higher altitudes. In general, in both gravity and magnetic modeling, errors increase greatly for prisms wider than 500 km, although gravity modeling is more sensitive than magnetic modeling to spherical-Earth effects. Preliminary modeling of both satellite gravity and magnetic anomalies using flat-Earth assumptions is justified considering the errors caused by uncertainties in isolating anomalies.

[Modification of L-asparaginase with colominic acid and the new characteristics of the modified enzyme].

PubMed

Wang, Y D; Guo, L; Qian, S J; Meng, G Z; Zhang, S Z

2000-07-01

The colominic acid was covalently coupled to L-asparaginase molecule by reductive amination. Depending on the molar ratios of colominic acid-asparaginase (30:1, 50:1 and 100:1), a modified enzyme molecule contained 4.7, 7.2 and 12 colominic acid molecule, they retained 58%, 56% and 33.2% of the initial asparaginase activity, respectively. In comparison with the native enzyme, modified enzyme had lower immunogenicity and antigenicity, longer half-life time (in vitro), more resistance ability to trypsin proteolysis, and similar Km value for L-asparagine.

Radio Sounding of the Martian and Venusian Ionospheres

NASA Astrophysics Data System (ADS)

Paetzold, M.; Haeusler, B.; Bird, M. K.; Peter, K.; Tellmann, S.; Tyler, G. L.; Withers, P.

2011-12-01

The Mars Express Radio Science Experiment MaRS and the radio science experiment Vera on Venus Express sound the ionospheres of Mars and Venus, respectively, at two frequencies in the microwave band and cover altitudes from the base of the ionosphere at 80 km (100 km at Venus) to the ionopause at altitudes between 300 km and 600 km. In general, both ionospheres consists of a lower layer M1 (V1 at Venus) at about 110 km (115 km), and the main layer M2 (V2) at about 135 km (145 km) altitude, both formed mainly by solar radiation at X-ray and EUV, respectively. The specific derivation and interpretation of the vertical electron density profiles at two radio frequencies from radio sounding is demonstrated in detail. Cases of quiet and disturbed ionospheric electron density profiles and cases of potential misinterpretations are presented. The behavior of the peak densities and peak altitudes of both ionospheres as a function of solar zenith angle and phase of the solar cycle as seen with Mars Express and Venus Express will be compared with past observations, models and conclusions.

Occultations by 81 Terpsichore and 694 Ekard in 2009 at Different Rotational Phase Angles

NASA Astrophysics Data System (ADS)

Timerson, Brad; Durech, J.; Pilcher, F.; Albers, J.; Beard, T.; Berger, B.; Berman, B.; Breit, D.; Case, T.; Collier, D.; Dantowitz, R.; Davies, T.; Desmarais, V.; Dunham, D.; Dunham, J.; Garlitz, J.; Garrett, L.; George, T.; Hill, M.; Hughes, Z.; Jacobson, G.; Kozubal, M.; Liu, Y.; Maley, P.; Morgan, W.; Morris, P.; Mroz, G.; Pool, S.; Preston, S.; Shelton, R.; Welch, S.; Westfall, J.; Whitman, A.; Wiggins, P.

2010-10-01

During 2009, IOTA observers in North America reported about 250 positive observations for 94 asteroidal occultation events. For two asteroids this included observations of multiple chords on two different dates which allowed well-defined profiles to be obtained at different rotational phase angles. Occultations by 81 Terpsichore on 2009 November 19 and 2009 December 25 yielded best-fit ellipses of 134.0 x 108.9 km and 123.6 x 112.2 km, respectively. Observations of 694 Ekard on 2009 September 23 and 2009 November 8 yielded fitted ellipses of 124.9 x 88.0 km and 88.5 x 104.0 km, respectively.

Inter-Annual Variability of Burned Area in Brazil Based on a Synergistic use of Information Derived from MODIS and Landsat-TM

NASA Astrophysics Data System (ADS)

Libonati, R.; Dacamara, C. C.; Setzer, A. W.; Morelli, F.

2014-12-01

A procedure is presented that allows using information from the MODerate resolution Imaging Spectroradiometer (MODIS) sensor to improve the quality of monthly burned area estimates over Brazil. The method integrates MODIS derived information from two sources; the NASA MCD64A1 Direct Broadcast Monthly Burned Area Product and INPE's Monthly Burned Area MODIS product (AQM-MODIS). The latter product relies on an algorithm that was specifically designed for ecosystems in Brazil, taking advantage of the ability of MIR reflectances to discriminate burned areas. Information from both MODIS products is incorporated by means of a linear regression model where an optimal estimate of the burned area is obtained as a linear combination of burned area estimates from MCD64A1 and AQM-MODIS. The linear regression model is calibrated using as optimal estimates values of burned area derived from Landsat TM during 2005 and 2006 over Jalapão, a region of Cerrado covering an area of 187 x 187 km2. Obtained values of coefficients for MCD64A1 and AQM-MODIS were 0.51 and 0.35, respectively and the root mean square error was 7.6 km2. Robustness of the model was checked by calibrating the model separately for 2005 and 2006 and cross-validating with 2006 and 2005; coefficients for 2005 (2006) were 0.46 (0.54) for MCD64A1 and 0.35 (0.35) for AQM-MODIS and the corresponding root mean square errors for 2006 (2005) were 7.8 (7.4) km2. The linear model was then applied to Brazil as well as to the six Brazilian main biomes, namely Cerrado, Amazônia, Caatinga, Pantanal, Mata Atlântica and Pampa. As to be expected the interannual variability based on the proposed synergistic use of MCD64A1, AQM-MODIS and Landsat Tm data for the period 2005-2010 presents marked differences with the corresponding amounts derived from MCD64A1 alone. For instance during the considered period, values (in 103 km2) from the proposed approach (from MCD64A1) are 399 (142), 232 (62), 559 (259), 274 (73), 219 (31) and 415 (251). Values obtained with the proposed approach may be viewed as an improved alternative to the currently available products over Brazil.

Analysis of sex differences in open-water ultra-distance swimming performances in the FINA World Cup races in 5 km, 10 km and 25 km from 2000 to 2012

PubMed Central

2014-01-01

Background The present study investigated the changes in swimming speeds and sex differences for elite male and female swimmers competing in 5 km, 10 km and 25 km open-water FINA World Cup races held between 2000 and 2012. Methods The changes in swimming speeds and sex differences across years were analysed using linear, non-linear, and multi-level regression analyses for the annual fastest and the annual ten fastest competitors. Results For the annual fastest, swimming speed remained stable for men and women in 5 km (5.50 ± 0.21 and 5.08 ± 0.19 km/h, respectively), in 10 km (5.38 ± 0.21 and 5.05 ± 0.26 km/h, respectively) and in 25 km (5.03 ± 0.32 and 4.58 ± 0.27 km/h, respectively). In the annual ten fastest, swimming speed remained constant in 5 km in women (5.02 ± 0.19 km/h) but decreased significantly and linearly in men from 5.42 ± 0.03 km/h to 5.39 ± 0.02 km/h. In 10 km, swimming speed increased significantly and linearly in women from 4.75 ± 0.01 km/h to 5.74 ± 0.01 km/h but remained stable in men at 5.36 ± 0.21 km/h. In 25 km, swimming speed decreased significantly and linearly in women from 4.60 ± 0.06 km/h to 4.44 ± 0.08 km/h but remained unchanged at 4.93 ± 0.34 km/h in men. For the annual fastest, the sex difference in swimming speed remained unchanged in 5 km (7.6 ± 3.0%), 10 km (6.1 ± 2.5%) and 25 km (9.0 ± 3.7%). For the annual ten fastest, the sex difference remained stable in 5 km at 7.6 ± 0.6%, decreased significantly and linearly in 10 km from 7.7 ± 0.7% to 1.2 ± 0.3% and increased significantly and linearly from 4.7 ± 1.4% to 9.6 ± 1.5% in 25 km. Conclusions To summarize, elite female open-water ultra-distance swimmers improved in 10 km but impaired in 25 km leading to a linear decrease in sex difference in 10 km and a linear increase in sex difference in 25 km. The linear changes in sex differences suggest that women will improve in the near future in 10 km, but not in 25 km. PMID:24559049

Anomalously high b-values in the South Flank of Kilauea volcano, Hawaii: Evidence for the distribution of magma below Kilauea's East rift zone

USGS Publications Warehouse

Wyss, M.; Klein, F.; Nagamine, K.; Wiemer, S.

2001-01-01

The pattern of b-value of the frequency-magnitude relation, or mean magnitude, varies little in the Kaoiki-Hilea area of Hawaii, and the b-values are normal, with b = 0.8 in the top 10 km and somewhat lower values below that depth. We interpret the Kaoiki-Hilea area as relatively stable, normal Hawaiian crust. In contrast, the b-values beneath Kilauea's South Flank are anomalously high (b = 1.3-1.7) at depths between 4 and 8 km, with the highest values near the East Rift zone, but extending 5-8 km away from the rift. Also, the anomalously high b-values vary along strike, parallel to the rift zone. The highest b-values are observed near Hiiaka and Pauahi craters at the bend in the rift, the next highest are near Makaopuhi and also near Puu Kaliu. The mildest anomalies occur adjacent to the central section of the rift. The locations of the three major and two minor b-value anomalies correspond to places where shallow magma reservoirs have been proposed based on analyses of seismicity, geodetic data and differentiated lava chemistry. The existence of the magma reservoirs is also supported by magnetic anomalies, which may be areas of dike concentration, and self-potential anomalies, which are areas of thermal upwelling above a hot source. The simplest explanation of these anomalously high b-values is that they are due to the presence of active magma bodies beneath the East Rift zone at depths down to 8 km. In other volcanoes, anomalously high b-values correlate with volumes adjacent to active magma chambers. This supports a model of a magma body beneath the East Rift zone, which may widen and thin along strike, and which may reach 8 km depth and extend from Kilauea's summit to a distance of at least 40 km down rift. The anomalously high b-values at the center of the South Flank, several kilometers away from the rift, may be explained by unusually high pore pressure throughout the South Flank, or by anomalously strong heterogeneity due to extensive cracking, or by both phenomena. The major b-value anomalies are located SSE of their parent reservoirs, in the direction of motion of the flank, suggesting that magma reservoirs leave an imprint in the mobile flank. We hypothesize that the extensive cracking may have been acquired when the anomalous parts of the South Flank, now several kilometers distant from the rift zone, were generated at the rift zone near persistent reservoirs. Since their generation, these volumes may have moved seaward, away from the rift, but earthquakes occurring in them still use the preexisting complex crack distribution. Along the decollement plane at 10 km depth, the b-values are exceptionally low (b = 0.5), suggesting faulting in a more homogeneous medium. ?? 2001 Elsevier Science B.V. All rights reserved.

METABOLISM OF N-ALKYLATED SPERMINE ANALOGUES BY POLYAMINE AND SPERMINE OXIDASES

PubMed Central

Häkkinen, Merja R.; Hyvönen, Mervi T.; Auriola, Seppo; Casero, Robert A.; Vepsäläinen, Jouko; Khomutov, Alex R.; Alhonen, Leena; Keinänen, Tuomo A.

2010-01-01

SUMMARY N-alkylated polyamine analogues have potential as anticancer and antiparasitic drugs. However, their metabolism in the host has remained incompletely defined thus potentially limiting their utility. Here, we have studied the degradation of three different spermine analogues N,N′-bis-(3-ethylaminopropyl)butane-1,4-diamine (DESPM), N-(3-benzyl-aminopropyl)-N'-(3-ethylaminopropyl)butane-1,4-diamine (BnEtSPM) and N,N′-bis-(3-benzylaminopropyl)butane-1,4-diamine (DBSPM) and related mono-alkylated derivatives as substrates of recombinant human polyamine oxidase (APAO) and spermine oxidase (SMO). APAO and SMO metabolized DESPM to EtSPD (Km(APAO)=10μM, kcat(APAO)=1.1s−1 and Km(SMO)=28μM, kcat(SMO)=0.8s−1, respectively), metabolized BnEtSPM to EtSPD (Km(APAO)=0.9 μM, kcat(APAO)=1.1s−1 and Km(SMO)=51μM, kcat(SMO)=0.4s−1, respectively), and metabolized DBSPM to BnSPD (Km(APAO)=5.4μM, kcat(APAO)= 2.0s−1 and Km(SMO)=33μM, kcat(SMO)=0.3s−1, respectively). Interestingly, mono-alkylated spermine derivatives were metabolized by APAO and SMO to SPD (EtSPM Km(APAO)=16μM, kcat(APAO)=1.5s−1; Km(SMO)=25μM, kcat(SMO) =8.2s−1; BnSPM Km(APAO)=6.0μM, kcat(APAO)=2.8s−1; Km(SMO)=19μM, kcat(SMO)=0.8s−1, respectively). Surprisingly, E t S P D ( Km(APAO)=37μM, kcat(APAO)=0.1s−1; Km(SMO)=48μM, kcat(SMO)=0.05s−1) and BnSPD (Km(APAO)=2.5μM, kcat(APAO)=3.5s−1; Km(SMO)=60μM, kcat(SMO)=0.54s−1) were metabolized to SPD by both the oxidases. Furthermore, we studied the degradation of DESPM, BnEtSPM or DBSPM in the DU145 prostate carcinoma cell line. The same major metabolites EtSPD and/or BnSPD were detected both in the culture medium and intracellularly after 48 hours of culture. Moreover, EtSPM and BnSPM were detected from cell samples. Present data shows that inducible SMO parallel with APAO could play an important role in polyamine based drug action, i.e. degradation of parent drug and its metabolites, having significant impact on efficiency of these drugs, and hence for the development of novel N-alkylated polyamine analogues. PMID:20012116

Energy cost of physical activities in 12-y-old girls: MET values and the influence of body weight.

PubMed

Spadano, J L; Must, A; Bandini, L G; Dallal, G E; Dietz, W H

2003-12-01

Few data exist on the energy cost of specific activities in children. The influence of body weight on the energy cost of activity when expressed as metabolic equivalents (METs) has not been vigorously explored. To provide MET data on five specific activities in 12-y-old girls and to test the hypothesis that measured MET values are independent of body weight. In 17 12-y-old girls, resting metabolic rate (RMR) and the energy expended while sitting, standing, walking on a flat treadmill at 3.2 and at 4.8 km/h, and walking on a treadmill at a 10% incline at 4.8 km/h were measured using indirect calorimetry. MET values were calculated by dividing the energy expenditure of an activity by the subject's RMR. The influence of body weight was assessed using simple linear regression. The observed METs were more consistent with published values for similar activities in adults than those offered for children. Body weight was a statistically significant predictor of the MET of all three walking activities, but not the MET of sitting or standing. Body weight explained 25% of the variance in the MET value for walking at 3.2 km/h, 39% for walking at 4.8 km/h, and 63% for walking at a 10% incline at 4.8 km/h. METs for the three walking activities were not independent of body weight. The use of average MET values to estimate the energy cost of these three activities would result in an underestimation of their energy cost in heavier girls and an overestimation in lighter girls. These results suggest that the estimation of total energy expenditure from activity diary, recall, and direct observation data using average MET values may be biased by body weight.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Lijuan; Kelly, Kenneth; Walkowicz, Kevin

The National Renewable Energy Laboratory's (NREL's) Fleet Test and Evaluations team recently conducted chassis dynamometer tests of a class 8 conventional regional delivery truck over the Heavy Heavy-Duty Diesel Truck (HHDDT), West Virginia University City (WVU City), and Composite International Truck Local and Commuter Cycle (CILCC) drive cycles. A quantitative study was conducted by analyzing the impacts of various factors on fuel consumption (FC) and fuel economy (FE) by modeling and simulating the truck using NREL's Future Automotive Systems Technology Simulator (FASTSim). Factors used in this study included vehicle weight, and the coefficients of rolling resistance and aerodynamic drag. Themore » simulation results from a single parametric study revealed that FC was approximately a linear function of the weight, coefficient of aerodynamic drag, and rolling resistance over various drive cycles. Among these parameters, the truck weight had the largest effect on FC. The study of the impact of two technologies on FE suggested that, depending on the circumstances, it may be more cost effective to reduce one parameter (such as coefficient of aerodynamic drag) to increase fuel economy, or it may be more beneficial to reduce another (such as the coefficient of rolling resistance). It also provided a convenient way to estimate FE by interpolating within the parameter values and extrapolating outside of them. The simulation results indicated that the FC could be reduced from 38.70 L/100 km, 50.72 L/100 km, and 38.42 L/100 km in the baseline truck to 26.78 L/100 km, 43.14 L/100 km and 29.84 L/100 km over the HHDDT, WVU City and CILCC drive cycles, respectively, when the U.S. Department of Energy's three targeted new technologies were applied simultaneously.« less

Vertical profile of polarization over Vladivostok using horizon shadowing: Clues to understanding the altitude variation of reflectance of aerosol particles

NASA Astrophysics Data System (ADS)

Pavlov, Andrey N.; Zubko, Evgenij; Konstantinov, Oleg G.; Shmirko, Konstantin; Mayor, Alexander Yu.; Videen, Gorden

2018-01-01

We report polarimetric measurements of atmospheric aerosol in evening and morning twilight over Vladivostok (Russia) in late winter-early spring of 2017 using a horizon-shadowing technique. Motion of the Sun beneath the horizon changes the altitude of the boundary of the shadowed atmosphere h, making it possible to constrain the altitude of aerosol particles contributing to the polarimetric response. We investigate the degree of linear polarization P in aerosol particles at different altitudes, ranging from 0 km up to 17 km. In two out of four experiments we found significant variations of the polarimetric response (ΔP ∼ 10%) with altitude; whereas, in the other measurements, the polarization appeared nearly the same (ΔP ∼ 2-3%) throughout the entire range of the studied altitude. Polarization P was measured in the zenith direction with the scattering angle being θ ∼ 90° At such a scattering angle, the polarization is near its maximum value Pmax. We analyze our measurements using the Umov effect that describes an inverse correlation between Pmax and the geometric albedo A. On 2017-02-21, we estimate A ≈ 0.0120 ± 0.0004 at h = 0 km and A ≈ 0.0154 ± 0.0026 at h = 10 km. On 2017-02-27, we find the opposite trend, A ≈ 0.0108 ± 0.0003 (h = 0 km) and A ≈ 0.0084 ± 0.0006 (h = 10 km). On 2017-03-02 and 2017-03-03 we find A ≈ 0.0084 ± 0.0009 and A ≈ 0.0090 ± 0.0010, respectively. Conclusions drawn from polarimetric measurements appear in qualitative accordance with results of remote sensing with a three-wavelength lidar.

Magma intrusion near Volcan Tancitaro: Evidence from seismic analysis

DOE PAGES

Pinzon, Juan I.; Nunez-Cornu, Francisco J.; Rowe, Charlotte Anne

2016-11-17

Between May and June 2006, an earthquake swarm occurred near Volcan Tancítaro in Mexico, which was recorded by a temporary seismic deployment known as the MARS network. We located ~1000 events from this seismic swarm. Previous earthquake swarms in the area were reported in the years 1997, 1999 and 2000. We relocate and analyze the evolution and properties of the 2006 earthquake swarm, employing a waveform cross-correlation-based phase repicking technique. Hypocenters from 911 events were located and divided into eighteen families having a correlation coefficient at or above 0.75. 90% of the earthquakes provide at least sixteen phase picks. Wemore » used the single-event location code Hypo71 and the P-wave velocity model used by the Jalisco Seismic and Accelerometer Network to improve hypocenters based on the correlation-adjusted phase arrival times. We relocated 121 earthquakes, which show clearly two clusters, between 9–10 km and 3–4 km depth respectively. The average location error estimates are <1 km epicentrally, and <2 km in depth, for the largest event in each cluster. Depths of seismicity migrate upward from 16 to 3.5 km and exhibit a NE-SW trend. The swarm first migrated toward Paricutin Volcano but by mid-June began propagating back toward Volcán Tancítaro. In addition to its persistence, noteworthy aspects of this swarm include a quasi-exponential increase in the rate of activity within the first 15 days; a b-value of 1.47; a jug-shaped hypocenter distribution; a shoaling rate of ~5 km/month within the deeper cluster, and a composite focal mechanism solution indicating largely reverse faulting. As a result, these features of the swarm suggest a magmatic source elevating the crustal strain beneath Volcan Tancítaro.« less

Magma intrusion near Volcan Tancitaro: Evidence from seismic analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinzon, Juan I.; Nunez-Cornu, Francisco J.; Rowe, Charlotte Anne

Between May and June 2006, an earthquake swarm occurred near Volcan Tancítaro in Mexico, which was recorded by a temporary seismic deployment known as the MARS network. We located ~1000 events from this seismic swarm. Previous earthquake swarms in the area were reported in the years 1997, 1999 and 2000. We relocate and analyze the evolution and properties of the 2006 earthquake swarm, employing a waveform cross-correlation-based phase repicking technique. Hypocenters from 911 events were located and divided into eighteen families having a correlation coefficient at or above 0.75. 90% of the earthquakes provide at least sixteen phase picks. Wemore » used the single-event location code Hypo71 and the P-wave velocity model used by the Jalisco Seismic and Accelerometer Network to improve hypocenters based on the correlation-adjusted phase arrival times. We relocated 121 earthquakes, which show clearly two clusters, between 9–10 km and 3–4 km depth respectively. The average location error estimates are <1 km epicentrally, and <2 km in depth, for the largest event in each cluster. Depths of seismicity migrate upward from 16 to 3.5 km and exhibit a NE-SW trend. The swarm first migrated toward Paricutin Volcano but by mid-June began propagating back toward Volcán Tancítaro. In addition to its persistence, noteworthy aspects of this swarm include a quasi-exponential increase in the rate of activity within the first 15 days; a b-value of 1.47; a jug-shaped hypocenter distribution; a shoaling rate of ~5 km/month within the deeper cluster, and a composite focal mechanism solution indicating largely reverse faulting. As a result, these features of the swarm suggest a magmatic source elevating the crustal strain beneath Volcan Tancítaro.« less

Magma intrusion near Volcan Tancítaro: Evidence from seismic analysis

NASA Astrophysics Data System (ADS)

Pinzón, Juan I.; Núñez-Cornú, Francisco J.; Rowe, Charlotte A.

2017-01-01

Between May and June 2006, an earthquake swarm occurred near Volcan Tancítaro in Mexico, which was recorded by a temporary seismic deployment known as the MARS network. We located ∼1000 events from this seismic swarm. Previous earthquake swarms in the area were reported in the years 1997, 1999 and 2000. We relocate and analyze the evolution and properties of the 2006 earthquake swarm, employing a waveform cross-correlation-based phase repicking technique. Hypocenters from 911 events were located and divided into eighteen families having a correlation coefficient at or above 0.75. 90% of the earthquakes provide at least sixteen phase picks. We used the single-event location code Hypo71 and the P-wave velocity model used by the Jalisco Seismic and Accelerometer Network to improve hypocenters based on the correlation-adjusted phase arrival times. We relocated 121 earthquakes, which show clearly two clusters, between 9-10 km and 3-4 km depth respectively. The average location error estimates are <1 km epicentrally, and <2 km in depth, for the largest event in each cluster. Depths of seismicity migrate upward from 16 to 3.5 km and exhibit a NE-SW trend. The swarm first migrated toward Paricutin Volcano but by mid-June began propagating back toward Volcán Tancítaro. In addition to its persistence, noteworthy aspects of this swarm include a quasi-exponential increase in the rate of activity within the first 15 days; a b-value of 1.47; a jug-shaped hypocenter distribution; a shoaling rate of ∼5 km/month within the deeper cluster, and a composite focal mechanism solution indicating largely reverse faulting. These features of the swarm suggest a magmatic source elevating the crustal strain beneath Volcan Tancítaro.

Calculations of mechanisms for balance control during narrow and single-leg standing in fit older adults: A reliability study.

PubMed

Aberg, A C; Thorstensson, A; Tarassova, O; Halvorsen, K

2011-07-01

For older people balance control in standing is critical for performance of activities of daily living without falling. The aims were to investigate reliability of quantification of the usage of the two balance mechanisms M(1) 'moving the centre of pressure' and M(2) 'segment acceleration' and also to compare calculation methods based on a combination of kinetic (K) and kinematic (Km) data, (K-Km), or Km data only concerning M(2). For this purpose nine physically fit persons aged 70-78 years were tested in narrow and single-leg standing. Data were collected by a 7-camera motion capture system and two force plates. Repeated measure ANOVA and Tukey's post hoc tests were used to detect differences between the standing tasks. Reliability was estimated by ICCs, standard error of measurement including its 95% CI, and minimal detectable change, whereas Pearson's correlation coefficient was used to investigate agreement between the two calculation methods. The results indicated that for the tasks investigated, M(1) and M(2) can be measured with acceptable inter- and intrasession reliability, and that both Km and K-Km based calculations may be useful for M(2), although Km data may give slightly lower values. The proportional M(1):M(2) usage was approximately 9:1, in both anterio-posterior (AP) and medio-lateral (ML) directions for narrow standing, and about 2:1 in the AP and of 1:2 in the ML direction in single-leg standing, respectively. In conclusion, the tested measurements and calculations appear to constitute a reliable way of quantifying one important aspect of balance capacity in fit older people. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparison of tropospheric NO2 vertical columns in an urban environment using satellite, multi-axis differential optical absorption spectroscopy, and in situ measurements

NASA Astrophysics Data System (ADS)

Mendolia, D.; D'Souza, R. J. C.; Evans, G. J.; Brook, J.

2013-10-01

Tropospheric NO2 vertical column densities have been retrieved and compared for the first time in Toronto, Canada, using three methods of differing spatial scales. Remotely sensed NO2 vertical column densities, retrieved from multi-axis differential optical absorption spectroscopy and satellite remote sensing, were evaluated by comparison with in situ vertical column densities estimated using a pair of chemiluminescence monitors situated 0.01 and 0.5 km a.g.l. (above ground level). The chemiluminescence measurements were corrected for the influence of NOz, which reduced the NO2 concentrations at 0.01 and 0.5 km by an average of 8 ± 1% and 12 ± 1%, respectively. The average absolute decrease in the chemiluminescence NO2 measurement as a result of this correction was less than 1 ppb. The monthly averaged ratio of the NO2 concentration at 0.5 to 0.01 km varied seasonally, and exhibited a negative linear dependence on the monthly average temperature, with Pearson's R = 0.83. During the coldest month, February, this ratio was 0.52 ± 0.04, while during the warmest month, July, this ratio was 0.34 ± 0.04, illustrating that NO2 is not well mixed within 0.5 km above ground level. Good correlation was observed between the remotely sensed and in situ NO2 vertical column densities (Pearson's R value ranging from 0.72 to 0.81), but the in situ vertical column densities were 52 to 58% greater than the remotely sensed columns. These results indicate that NO2 horizontal heterogeneity strongly impacted the magnitude of the remotely sensed columns. The in situ columns reflected an urban environment with major traffic sources, while the remotely sensed NO2 vertical column densities were representative of the region, which included spatial heterogeneity introduced by residential neighbourhoods and Lake Ontario. Despite the difference in absolute values, the reasonable correlation between the vertical column densities determined by three distinct methods increased confidence in the validity of the values provided by each measurement technique.

Age and ultra-marathon performance - 50 to 1,000 km distances from 1969 - 2012.

PubMed

Romer, Tobias; Rüst, Christoph Alexander; Zingg, Matthias Alexander; Rosemann, Thomas; Knechtle, Beat

2014-01-01

We investigated age and performance in distance-limited ultra-marathons held from 50 km to 1,000 km. Age of peak running speed and running speed of the fastest competitors from 1969 to 2012 in 50 km, 100 km, 200 km and 1,000 km ultra-marathons were analyzed using analysis of variance and multi-level regression analyses. The ages of the ten fastest women ever were 40 ± 4 yrs (50 km), 34 ± 7 yrs (100 km), 42 ± 6 yrs (200 km), and 41 ± 5 yrs (1,000 km). The ages were significantly different between 100 km and 200 km and between 100 km and 1,000 km. For men, the ages of the ten fastest ever were 34 ± 6 yrs (50 km), 32 ± 4 yrs (100 km), 44 ± 4 yrs (200 km), and 47 ± 9 yrs (1,000 km). The ages were significantly younger in 50 km compared to 100 km and 200 km and also significantly younger in 100 km compared to 200 km and 1,000 km. The age of the annual ten fastest women decreased in 50 km from 39 ± 8 yrs (1988) to 32 ± 4 yrs (2012) and in men from 35 ± 5 yrs (1977) to 33 ± 5 yrs (2012). In 100 km events, the age of peak running speed of the annual ten fastest women and men remained stable at 34.9 ± 3.2 and 34.5 ± 2.5 yrs, respectively. Peak running speed of top ten runners increased in 50 km and 100 km in women (10.6 ± 1.0 to 15.3 ± 0.7 km/h and 7.3 ± 1.5 to 13.0 ± 0.2 km/h, respectively) and men (14.3 ± 1.2 to 17.5 ± 0.6 km/h and 10.2 ± 1.2 to 15.1 ± 0.2 km/h, respectively). In 200 km and 1,000 km, running speed remained unchanged. In summary, the best male 1,000 km ultra-marathoners were ~15 yrs older than the best male 100 km ultra-marathoners and the best female 1,000 km ultra-marathoners were ~7 yrs older than the best female 100 km ultra-marathoners. The age of the fastest 50 km ultra-marathoners decreased across years whereas it remained unchanged in 100 km ultra-marathoners. These findings may help athletes and coaches to plan an ultra-marathoner's career. Future studies are needed on the mechanisms by which the fastest runners in the long ultra-marathons tend to be older than those in shorter ultra-marathons.

Structure and rheology of the lithosphere below southeastern margin of India and Sri Lanka, and its conjugate segment of the east Antarctica: Implications on early breakup history and margin formation

NASA Astrophysics Data System (ADS)

Rao Gangumalla, Srinivasa; Radhakrishna, Munukutla

2014-05-01

The eastern continental margin of India has evolved as a consequence of rifting and breakup between India and east Antarctica during the early Cretaceous. Plate reconstruction models for the breakup of eastern Gondwanaland by many earlier workers have unambiguously placed the southeast margin of Sri Lanka and India together as a conjugate segment with the east Antarctica margin that extends from Gunnerus Ridge in the west to western Enderby basin in the east. In this study, we present results of integrated analysis of gravity, geoid, magnetic and seismic data from these two conjugate portions in order to examine the lithosphere structure and early seafloor spreading, style of breakup, continent-ocean boundary (COB) and rheological characteristics at these margins. The interpreted COB lies at a distance of 55-140 km on the side of southeast margin of Sri Lanka and India, whereas, it lies at a distance of 190-550 km on the side of east Antarctica margin. The seismic profiles and the constrained potential field models across these two segments do not show the existence of seaward dipping reflector sequences or magmatic underplating suggesting that these segments have not encountered major magmatic activity. While, significant crustal thinning/stretching is observed at the east Antarctic margin, the Cauvery offshore had experienced limited stretching with faulted Moho interface. Further, the conspicuous residual geoid low in the Cauvery offshore basin is inferred to be due to a continental crustal block. The modelled Lithosphere-Astenosphere Boundary (LAB) in these two margins is located around 110-120 km depth with slightly thicker lithosphere at the east Antarctica margin. In addition, the interpretation of magnetic anomalies provided structure of the oceanic crust generated through seafloor spreading processes with age and magnetization data constrained from the identified magnetic anomalies in the respective margins. Using the Bouguer coherence method, we computed spatial variations in effective elastic thickness (Te) at these margin segments. The estimated Te values at the Indian margin ranges between 5-8 km in the southeast of Sri Lanka to around 10-12 km in the Cauvery offshore which decrease further north to < 5 km in the Cauvery-Palar basin. Along the east Antarctic margin, the Te values ranges between 5-10 km in the Gunnerus ridge region, 35-40 km in the western Enderby basin which decrease further towards the central Enderby basin up to 20 km. In this study, the above results have been analyzed in terms of early breakup mechanism and subsequent evolution of these two conjugate segments.

3-D Vp/Vs Ratio Distribution in the Geothermal Reservoir at Basel, Switzerland, from Microseismic Data

NASA Astrophysics Data System (ADS)

Kummerow, J.; Reshetnikov, A.; Häring, M.; Asanuma, H.

2012-12-01

Thousands of microseismic events occurred during and after the stimulation of the 4.5km deep Basel 1 well at the Deep Heat Mining Project in Basel, Switzerland, in December 2006. The located seismicity extends about 1km in vertical direction and also 1km in NNW-SSE direction, consistent with the orientation of the maximum horizontal stress. In this study, we analyze 2100 events with magnitudes Mw>0.0, which were recorded by six borehole seismometers between December 2, 2006, and June 7, 2007. We first identify event multiplets based on waveform similarity and apply an automatic, iterative arrival time optimization to calculate high-precision P and S time picks for the multiplet events. Local estimates of the Vp/Vs ratio in the stimulated Basel geothermal reservoir are then obtained from the slope of the demeaned differential S versus P arrival times. The average value of Vp/Vs=1.70 is close to the characteristic reservoir value of 1.72, which was determined independently from sonic log measurements. Also, in the vicinity of the borehole, the depth distribution of Vp/Vs correlates well with the low-pass filtered sonic log data: Vp/Vs values are less than 1.70 at the top of the seismicity cloud at <3.9km depth, close to average at 4.0-4.4km depth, and exceed the value of 1.75 at larger depth (4.4-4.6km), consistent with the sonic log data. Furthermore, we observe a correlation of anomalous Vp/Vs values with zones of enhanced seismic reflectivity which were resolved by microseismic reflection imaging. Away from the borehole, increased Vp/Vs ratios also seem to correlate with domains of high event density, possibly indicating fluid migration paths.

A First Layered Crustal Velocity Model for the Western Solomon Islands: Inversion of Measured Group Velocity of Surface Waves using Ambient Noise Cross-Correlation

NASA Astrophysics Data System (ADS)

Ku, C. S.; Kuo, Y. T.; Chao, W. A.; You, S. H.; Huang, B. S.; Chen, Y. G.; Taylor, F. W.; Yih-Min, W.

2017-12-01

Two earthquakes, MW 8.1 in 2007 and MW 7.1 in 2010, hit the Western Province of Solomon Islands and caused extensive damage, but motivated us to set up the first seismic network in this area. During the first phase, eight broadband seismic stations (BBS) were installed around the rupture zone of 2007 earthquake. With one-year seismic records, we cross-correlated the vertical component of ambient noise recorded in our BBS and calculated Rayleigh-wave group velocity dispersion curves on inter-station paths. The genetic algorithm to invert one-dimensional crustal velocity model is applied by fitting the averaged dispersion curves. The one-dimensional crustal velocity model is constituted by two layers and one half-space, representing the upper crust, lower crust, and uppermost mantle respectively. The resulted thickness values of the upper and lower crust are 6.4 and 14.2 km, respectively. Shear-wave velocities (VS) of the upper crust, lower crust, and uppermost mantle are 2.53, 3.57 and 4.23 km/s with the VP/VS ratios of 1.737, 1.742 and 1.759, respectively. This first layered crustal velocity model can be used as a preliminary reference to further study seismic sources such as earthquake activity and tectonic tremor.

Black Sea impact on its west-coast land surface temperature

NASA Astrophysics Data System (ADS)

Cheval, Sorin; Constantin, Sorin

2018-03-01

This study investigates the Black Sea influence on the thermal characteristics of its western hinterland based on satellite imagery acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS). The marine impact on the land surface temperature (LST) values is detected at daily, seasonal and annual time scales, and a strong linkage with the land cover is demonstrated. The remote sensing products used within the study supply LST data with complete areal coverage during clear sky conditions at 1-km spatial resolution, which is appropriate for climate studies. The sea influence is significant up to 4-5 km, by daytime, while the nighttime influence is very strong in the first 1-2 km, and it gradually decreases westward. Excepting the winter, the daytime temperature increases towards the plateau with the distance from the sea, e.g. with a gradient of 0.9 °C/km in the first 5 km in spring or with 0.7 °C/km in summer. By nighttime, the sea water usually remains warmer than the contiguous land triggering higher LST values in the immediate proximity of the coastline in all seasons, e.g. mean summer LST is 19.0 °C for the 1-km buffer, 16.6 °C for the 5-km buffer and 16.0 °C for the 10-km buffer. The results confirm a strong relationship between the land cover and thermal regime in the western hinterland of the Black Sea coast. The satellite-derived LST and air temperature values recorded at the meteorological stations are highly correlated for similar locations, but the marine influence propagates differently, pledging for distinct analysis. Identified anomalies in the general observed trends are investigated in correlation with sea surface temperature dynamics in the coastal area.

Stratospheric aerosols from the Sarychev volcano eruption in the 2009 Arctic summer

NASA Astrophysics Data System (ADS)

Jégou, F.; Berthet, G.; Brogniez, C.; Renard, J.-B.; François, P.; Haywood, J. M.; Jones, A.; Bourgeois, Q.; Lurton, T.; Auriol, F.; Godin-Beekmann, S.; Guimbaud, C.; Krysztofiak, G.; Gaubicher, B.; Chartier, M.; Clarisse, L.; Clerbaux, C.; Balois, J. Y.; Verwaerde, C.; Daugeron, D.

2013-07-01

Aerosols from the Sarychev volcano eruption (Kuril Islands, northeast of Japan) were observed in the Arctic lower stratosphere a few days after the strongest SO2 injection which occurred on 15 and 16 June 2009. From the observations provided by the Infrared Atmospheric Sounding Interferometer (IASI) an estimated 0.9 Tg of sulphur dioxide was injected into the upper troposphere and lower stratosphere (UTLS). The resultant stratospheric sulphate aerosols were detected from satellites by the Optical Spectrograph and Infrared Imaging System (OSIRIS) limb sounder and by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and from the surface by the Network for the Detection of Atmospheric Composition Changes (NDACC) lidar deployed at OHP (Observatoire de Haute-Provence, France). By the first week of July the aerosol plume had spread out over the entire Arctic region. The Sarychev-induced stratospheric aerosol over the Kiruna region (north of Sweden) was measured by the Stratospheric and Tropospheric Aerosol Counter (STAC) during eight balloon flights planned in August and September 2009. During this balloon campaign the Micro Radiomètre Ballon (MicroRADIBAL) and the Spectroscopie d'Absorption Lunaire pour l'Observation des Minoritaires Ozone et NOx (SALOMON) remote-sensing instruments also observed these aerosols. Aerosol concentrations returned to near-background levels by spring 2010. The effective radius, the surface area density (SAD), the aerosol extinction, and the total sulphur mass from STAC in situ measurements are enhanced with mean values in the range 0.15-0.21 μm, 5.5-14.7 μm2 cm-3, 5.5-29.5 × 10-4 km-1, and 4.9-12.6 × 10-10 kg[S] kg-1[air], respectively, between 14 km and 18 km. The observed and modelled e-folding time of sulphate aerosols from the Sarychev eruption is around 70-80 days, a value much shorter than the 12-14 months calculated for aerosols from the 1991 eruption of Mt Pinatubo. The OSIRIS stratospheric aerosol optical depth (AOD) at 750 nm is enhanced by a factor of 6, with a value of 0.02 in late July compared to 0.0035 before the eruption. The HadGEM2 and MIMOSA model outputs indicate that aerosol layers in polar region up to 14-15 km are largely modulated by stratosphere-troposphere exchange processes. The spatial extent of the Sarychev plume is well represented in the HadGEM2 model with lower altitudes of the plume being controlled by upper tropospheric troughs which displace the plume downward and upper altitudes around 18-20 km, in agreement with lidar observations. Good consistency is found between the HadGEM2 sulphur mass density and the value inferred from the STAC observations, with a maximum located about 1 km above the tropopause ranging from 1 to 2 × 10-9 kg[S] kg-1[air], which is one order of magnitude higher than the background level.

Modeling of the strong ground motion of 25th April 2015 Nepal earthquake using modified semi-empirical technique

NASA Astrophysics Data System (ADS)

Lal, Sohan; Joshi, A.; Sandeep; Tomer, Monu; Kumar, Parveen; Kuo, Chun-Hsiang; Lin, Che-Min; Wen, Kuo-Liang; Sharma, M. L.

2018-05-01

On 25th April, 2015 a hazardous earthquake of moment magnitude 7.9 occurred in Nepal. Accelerographs were used to record the Nepal earthquake which is installed in the Kumaon region in the Himalayan state of Uttrakhand. The distance of the recorded stations in the Kumaon region from the epicenter of the earthquake is about 420-515 km. Modified semi-empirical technique of modeling finite faults has been used in this paper to simulate strong earthquake at these stations. Source parameters of the Nepal aftershock have been also calculated using the Brune model in the present study which are used in the modeling of the Nepal main shock. The obtained value of the seismic moment and stress drop is 8.26 × 1025 dyn cm and 10.48 bar, respectively, for the aftershock from the Brune model .The simulated earthquake time series were compared with the observed records of the earthquake. The comparison of full waveform and its response spectra has been made to finalize the rupture parameters and its location. The rupture of the earthquake was propagated in the NE-SW direction from the hypocenter with the rupture velocity 3.0 km/s from a distance of 80 km from Kathmandu in NW direction at a depth of 12 km as per compared results.

The YAK-AEROSIB transcontinental aircraft campaigns: new insights on the transport of CO2, CO and O3 across Siberia

NASA Astrophysics Data System (ADS)

Paris, J.-D.; Ciais, P.; Nédélec, P.; Ramonet, M.; Belan, B. D.; Arshinov, M. Yu.; Golitsyn, G. S.; Granberg, I.; Stohl, A.; Cayez, G.; Athier, G.; Boumard, F.; Cousin, J.-M.

2008-09-01

Two airborne campaigns were carried out to measure the tropospheric concentrations and variability of CO2, CO and O3 over Siberia. In order to quantify the influence of remote and regional natural and anthropogenic sources, we analysed a total of 52 vertical profiles of these species collected in April and September 2006, every ~200 km and up to 7 km altitude. CO2 and CO concentrations were high in April 2006 (respectively 385-390 ppm CO2 and 160-200 ppb CO) compared to background values. CO concentrations up to 220 ppb were recorded above 3.5 km over eastern Siberia, with enhancements in 500-1000 m thick layers. The presence of CO enriched air masses resulted from a quick frontal uplift of a polluted air mass exposed to northern China anthropogenic emissions and to fire emissions in northern Mongolia. A dominant Asian origin for CO above 4 km (71.0%) contrasted with a dominant European origin below this altitude (70.9%) was deduced both from a transport model analysis, and from the contrasted ΔCO/ΔCO2 ratio vertical distribution. In September 2006, a significant O3 depletion (~ -30 ppb) was repeatedly observed in the boundary layer, as diagnosed from virtual potential temperature profiles and CO2 gradients, compared to the free troposphere aloft, suggestive of a strong O3 deposition over Siberian forests.

The Ottaviano eruption of Somma-Vesuvio (8000 y B.P.): a magmatic alternating fall and flow-forming eruption

NASA Astrophysics Data System (ADS)

Rolandi, G.; Maraffi, S.; Petrosino, P.; Lirer, L.

1993-11-01

The Ottaviano eruption occurred in the late neolithic (8000 y B.P.). 2.40 km 3 of phonolitic pyroclastic material (0.61 km 3 DRE) were emplaced as pyroclastic flow, surge and fall deposits. The eruption began with a fall phase, with a model column height of 14 km, producing a pumice fall deposit (LA). This phase ended with short-lived weak explosive activity, giving rise to a fine-grained deposit (L1), passing to pumice fall deposits as the result of an increasing column height and mass discharge rate. The subsequent two fall phases (producing LB and LC deposits), had model column heights of 20 and 22 km with eruption rates of 2.5 × 10 7 and 2.81 × 10 7 kg/s, respectively. These phases ended with the deposition of ash layers (L2 and L3), related to a decreasing, pulsing explosive activity. The values of dynamic parameters calculated for the eruption classify it as a sub-plinian event. Each fall phase was characterized by variations in the eruptive intensity, and several pyroclastic flows were emplaced (F1 to F3). Alternating pumice and ash fall beds record the waning of the eruption. Finally, owing to the collapse of a eruptive column of low gas content, the last pyroclastic flow (F4) was emplaced.

Simple, direct drug susceptibility testing technique for diagnosis of drug-resistant tuberculosis in resource-poor settings.

PubMed

Kim, C-K; Joo, Y-T; Lee, E P; Park, Y K; Kim, H-J; Kim, S J

2013-09-01

The Korean Institute of Tuberculosis, Seoul, Republic of Korea. To develop a simple, direct drug susceptibility testing (DST) technique using Kudoh-modified Ogawa (KMO) medium. The critical concentrations of isoniazid (INH), rifampicin (RMP), kanamycin (KM) and ofloxacin (OFX) for KMO medium were calibrated by comparing the minimal inhibitory concentrations (MICs) against clinical isolates of Mycobacterium tuberculosis on KMO with those on Löwenstein-Jensen (LJ). The performance of the direct KMO DST technique was evaluated on 186 smear-positive sputum specimens and compared with indirect LJ DST. Agreement of MICs on direct vs. indirect DST was high for INH, RMP and OFX. KM MICs on KMO were ∼10 g/ml higher than those on LJ. The critical concentrations of INH, RMP, OFX and KM for KMO were therefore set at 0.2, 40.0, 2.0, and 40.0 g/ml. The evaluation of direct DST of smear-positive sputum specimens showed 100% agreement with indirect LJ DST for INH and RMP. However, the respective susceptible and resistant predictive values were 98.8% and 100% for OFX, and 100% and 80% for KM. Direct DST using KMO is useful, with clear advantages of a shorter turnaround time, procedural simplicity and low cost compared to indirect DST. It may be most indicated in resource-poor settings for programmatic management of drug-resistant tuberculosis.

Surface magnetometer experiments: Internal lunar properties

NASA Technical Reports Server (NTRS)

Dyal, P.; Parkin, C. W.; Daily, W. D.

1973-01-01

Magnetic fields have been measured on the lunar surface at the Apollo 12, 14, 15, and 16 landing sites. The remanent field values at these sites are respectively 38 gammas, 103 gammas (maximum), 3 gammas, and 327 gammas. Simultaneous magnetic field and solar plasma pressure measurements show that the remanent fields at the Apollo 12 and 16 sites are compressed and that the scale size of the Apollo 16 remanent field is 5 or = L 100 km. The global eddy current fields, induced by magnetic step transients in the solar wind, were analyzed to calculate an electrical conductivity profile. From nightside data it was found that deeper than 170 km into the moon, the conductivity rises from 0.0003 mhos/m to 0.01 mhos/m at 1000 km depth. Analysis of dayside transient data using a spherically symmetric two-layer model yields a homogeneous conducting core of radios 0.9 R and conductivity sigma = 0.001 mhos/m, surrounded by a nonconducting shell of thickness 0.1 R. This result is in agreement with a nonconducting profile determined from nightside data. The conductivity profile is used to calculate the temperature for an assumed lunar material of peridotite. In an outer layer the temperature rises to 850 to 1050 K, after which it gradually increases to 1200 to 1500 K at a depth of approximately 1000 km.

Source parameters for the 1952 Kern County earthquake, California: A joint inversion of leveling and triangulation observations

USGS Publications Warehouse

Bawden, G.W.

2001-01-01

Coseismic leveling and triangulation observations are used to determine the faulting geometry and slip distribution of the July 21, 1952, Mw 7.3 Kem County earthquake on the White Wolf fault. A singular value decomposition inversion is used to assess the ability of the geodetic network to resolve slip along a multisegment fault and shows that the network is sufficient to resolve slip along the surface rupture to a depth of 10 km. Below 10 km, the network can only resolve dip slip near the fault ends. The preferred source model is a two-segment right-stepping fault with a strike of 51?? and a dip of 75?? SW. The epicentral patch has deep (6-27 km) leftlateral oblique slip, while the northeastern patch has shallow (1-12.5 km) reverse slip. There is nearly uniform reverse slip (epicentral, 1.6 m; northeast, 1.9 m), with 3.6 m of left-lateral strike slip limited to the epicentral patch. The seismic moment is M0= 9.2 ?? 0.5 ?? 1019 N m (Mw= 7.2). The signal-to-noise ratio of the leveling and triangulation data is reduced by 96% and 49%, respectively. The slip distribution from the preferred model matches regional geomorphic features and may provide a driving mechanism for regional shortening across the Comanche thrust and structural continuity with the Scodie seismic lineament to the northeast.

Kinetic measurement of 2-aminopurine X cytosine and 2-aminopurine X thymine base pairs as a test of DNA polymerase fidelity mechanisms.

PubMed Central

Watanabe, S M; Goodman, M F

1982-01-01

Enzyme kinetic measurements are presented showing that Km rather than maximum velocity (Vmax) discrimination governs the frequency of forming 2-aminopurine X cytosine base mispairs by DNA polymerase alpha. An in vitro system is used in which incorporation of dTMP or dCMP occurs opposite a template 2-aminopurine, and values for Km and Vmax are obtained. Results from a previous study in which dTTP and dCTP were competing simultaneously for insertion opposite 2-aminopurine indicated that dTMP is inserted 22 times more frequently than dCMP. We now report that the ratio of Km values KCm/KTm = 25 +/- 6, which agrees quantitatively with the dTMP/dCMP incorporation ratio obtained previously. We also report that VCmax is indistinguishable from VTmax. These Km and Vmax data are consistent with predictions from a model, the Km discrimination model, in which replication fidelity is determined by free energy differences between matched and mismatched base pairs. Central to this model is the prediction that the ratio of Km values for insertion of correct and incorrect nucleotides specifies the insertion fidelity, and the maximum velocities of insertion are the same for both nucleotides. PMID:6959128

The Hetu'u Global Network: Measuring the Distance to the Sun with the Transit of Venus

NASA Astrophysics Data System (ADS)

Rodriguez, David; Faherty, J.

2013-01-01

In the spirit of historic astronomical endeavors, we invited school groups across the globe to collaborate in a solar distance measurement using the 2012 transit of Venus. In total, our group (stationed at Easter Island, Chile) recruited 19 school groups spread over 6 continents and 10 countries to participate in our Hetu’u Global Network. Applying the methods of French astronomer Joseph-Nicolas Delisle, we used individual second and third Venus-Sun contact times to calculate the distance to the Sun. Ten of the sites in our network had amiable weather; 8 of which measured second contact and 5 of which measured third contact leading to consistent solar distance measurements of 152+/-30 million km and 163+/-30 million km respectively. The distance to the Sun at the time of the transit was 152.25 million km; therefore, our measurements are also consistent within 1-sigma of the known value. The goal of our international school group network was to inspire the next generation of scientists using the excitement and accessibility of such a rare astronomical event. In the process, we connected hundreds of participating students representing a diverse, multi-cultural group with differing political, economic, and racial backgrounds.

The metabolism of 5-hydroxytryptamine and beta-phenylethylamine in perfused rat lung and in vitro.

PubMed Central

Bakhle, Y S; Youdim, M B

1979-01-01

1 Metabolism of 5-hydroxytryptamine (5-HT) and beta-phenylethylamine (PHE) by monoamine oxidase (MAO) was investigated in rat isolated lungs and in mitochondrial preparations from rat lung. 2. In perfused lungs 5-HT metabolism had an apparent Km of 2 microgram and PHE metaoblism a Km of 54 microgram, whereas in vitro the Km values were 330 microgram and 28 microgram respectively. 3 In vitro, MAO activity had substrate and inhibitor specificities compatible with the presence of A and B types of MAO. 4 In perfused lung, metabolism of 5-HT but not that of PHE was inhibited by desmethylimipramine. 5 These results show that PHE metabolism in perfused lung, unlike that of other metabolized amines, is not limited by transport and the transport process for PHE is unlike that of 5-HT or noradrenaline. 6 These results also show that the kinetic parameters obtained for MAO activity in vitro do not generally apply to the isolated lung where transport of substrate can be the deciding factor. This discrepancy emphasizes that the enzymic properties of the whole organ cannot relaibly be deduced from its enzymic content. PMID:32944

Ground Motion in Lima: Pisco Earthquake of August 15, 2007 (Mw7.9)

NASA Astrophysics Data System (ADS)

Bernal, I.; Tavera, H.

2008-05-01

On 15 of August of 2007 at 06h 40min, local time, the central region of Peru was shooked by an earthquake magnitude Mw=7.9 with epicenter at 13.49°S and -76.85°W; this is, 74 km west of the city of Pisco. The earthquake was recorded by a total of fourteen accelerometers that operate in the city of Lima which show clearly the development of a complex process of rupture formed by two sources (R1 and R2) separated by 60-70 seconds. Maximum acceleration registered in the city of Lima was of 115.2 cm/seg² (0.12g) in the Urb. The Rinconada of the district the Molina located 155 km northwest from the epicenter. The periods associated to the maximum spectral acceleration appear to be between 0.1 to 0.4s in RIN and MOL, both located in the La Molina District; for ANC, CSM, MAY located in the Ancon, Rímac and Ate Vitarte district, are within the range of 0.1-0.6s; for CER, ANR, PUCP, CLD-CIP located in the San Borja, Santiago de Surco, San Miguel and San Isidro district the range is of 0.1-1.2s, and for CAL in Callao it is of 0.1-1.6s. The predominant periods have values close to 0.1s in the Molina and San Miguel distric, of 0.2s in Ate Vitarte and Rimac, of 0.3s in the Molina, Rimac, Ate Vitarte and Ancon, and of 0.5s in Santiago de Surco disctrict. In the Molina district, two acelerometric stations are located at less than 2 km away from each other, and present predominant periods next to 0.1s and 0.3s, which implies a strong variation of the physical properties of the ground at short distances. Shear wave velocity estimates, using the unidimensional method at stations MOL, MAY and ANC, give values of 80 m/s (with thicknesses less than 2 m), 200 m/s (with thicknesses less than 9 m) and of 690 m/s for the halfspace, values that suggest a compacted ground with respect to the rest of stations. Stations CAL and RIN show velocities of 60 of m/s (with thicknesses of 11 and 3 m respectively), a second layer of 140 m/s (with thicknesses of 12 and 7 m) over a halfspace of 450 m/s. These values are interpreted as representing less compacted grounds.

Using a reactive transport model to elucidate differences between laboratory and field dissolution rates in regolith

NASA Astrophysics Data System (ADS)

Moore, Joel; Lichtner, Peter C.; White, Art F.; Brantley, Susan L.

2012-09-01

The reactive transport model FLOTRAN was used to forward-model weathering profiles developed on granitic outwash alluvium over 40-3000 ka from the Merced, California (USA) chronosequence as well as deep granitic regolith developed over 800 ka near Davis Run, Virginia (USA). Baseline model predictions that used laboratory rate constants (km), measured fluid flow velocities (v), and BET volumetric surface areas for the parent material (AB,mo) were not consistent with measured profiles of plagioclase, potassium feldspar, and quartz. Reaction fronts predicted by the baseline model are deeper and thinner than the observed, consistent with faster rates of reaction in the model. Reaction front depth in the model depended mostly upon saturated versus unsaturated hydrologic flow conditions, rate constants controlling precipitation of secondary minerals, and the average fluid flow velocity (va). Unsaturated hydrologic flow conditions (relatively open with respect to CO2(g)) resulted in the prediction of deeper reaction fronts and significant differences in the separation between plagioclase and potassium feldspar reaction fronts compared to saturated hydrologic flow (relatively closed with respect to CO2(g)). Under saturated or unsaturated flow conditions, the rate constant that controls precipitation rates of secondary minerals must be reduced relative to laboratory rate constants to match observed reaction front depths and measured pore water chemistry. Additionally, to match the observed reaction front depths, va was set lower than the measured value, v, for three of the four profiles. The reaction front gradients in mineralogy and pore fluid chemistry could only be modeled accurately by adjusting values of the product kmAB,mo. By assuming km values were constrained by laboratory data, field observations were modeled successfully with TST-like rate equations by dividing measured values of AB,mo by factors from 50 to 1700. Alternately, with sigmoidal or Al-inhibition rate models, this adjustment factor ranges from 5 to 170. Best-fit models of the wetter, hydrologically saturated Davis Run profile required a smaller adjustment to AB,mo than the drier hydrologically unsaturated Merced profiles. We attributed the need for large adjustments in va and AB,mo necessary for the Merced models to more complex hydrologic flow that decreased the reactive surface area in contact with bulk flow water, e.g., dead-end pore spaces containing fluids that are near or at chemical equilibrium. Thus, rate models from the laboratory can successfully predict weathering over millions of years, but work is needed to understand how to incorporate changes in what controls the relationship between reactive surface area and hydrologic flow.

Monitoring diffuse degassing in monogentic volcanic field during a quiescent period: the case of Cumbre Vieja (La Palma,Canary Islands, Spain)

NASA Astrophysics Data System (ADS)

Burns, F.; Cole, M.; Vaccaro, W.; Alonso Cótchico, M.; Melián, G.; Asensio-Ramos, M.; Padron, E.; Hernandez Perez, P. A.; Perez, N. M.

2017-12-01

Volcanic activity at La Palma (Canary Islands) in the last 123 ka has taken place exclusively at the southern part of the island, where Cumbre Vieja volcano, which is characterized by a main north-south rift zone 20 km long and up to 1950 m in elevation and covering an area of 220 km2 with vents located also at the northwest and northeast. Cumbre Vieja is the most active basaltic volcano in the Canaries with 7 historical eruptions being San Juan (1949) and Teneguía (1971) the most recent ones. Since no visible degassing (fumaroles, etc.) at Cumbre Vieja occurs, our geochemical program for the volcanic surveillance of Cumbre Vieja is mainly focused on diffuse degassing monitoring. Diffuse CO2 emission surveys are yearly performed in summer to minimize the influence of meteorological variations. About 570 sampling sites were selected for each survey to obtain a homogeneous distribution after taking into consideration the local geology, structure, and accessibility. Measurements of soil CO2 efflux were performed in situ by means of a portable non-dispersive infrared sensor following the accumulation chamber method. The soil CO2 efflux values of the 2017 survey ranged from non-detectable to 47.7 g m-2 d-1. Statistical-graphical analysis of the data show two different geocheleemical populations; background (B) and peak (P) represented by 98.2% and 1.8% of the total data, respectively. The geometric means of the B and P populations are 2.9 and 36.5 g m-2 d-1, respectively. Most of the area showed B values while the P values were mainly observed both flanks of the main N-S volcanic rift. To estimate the diffuse CO2 emission in metric tons per day released from Cumbre Vieja (220 km2) for the 2017 survey, we ran about 100 sGs simulations. The estimated 2017 diffuse CO2 output released to atmosphere by Cumbre Vieja was at 801 ± 27 t d-1, value relatively higher than the background average of CO2 emission estimated on 374 t d-1 and within the background range of 132 t d-1 (-1σ) and 1.254 t d-1 (+1σ) observed at Cumbre Vieja volcano during the period 2001-2013 (Padrón et al., 2015. Bull. Volcanol. 77:28). Monitoring the diffuse CO2 emission contributes to detect early warning signals of volcanic unrest at Cumbre Vieja volcano.

Extreme-event geoelectric hazard maps: Chapter 9

USGS Publications Warehouse

Love, Jeffrey J.; Bedrosian, Paul A.

2018-01-01

Maps of geoelectric amplitude covering about half the continental United States are presented that will be exceeded, on average, once per century in response to an extreme-intensity geomagnetic disturbance. These maps are constructed using an empirical parameterization of induction: convolving latitude-dependent statistical maps of extreme-value geomagnetic disturbances, obtained from decades of 1-minute magnetic observatory data, with local estimates of Earth-surface impedance obtained at discrete geographic sites from magnetotelluric surveys. Geoelectric amplitudes are estimated for geomagnetic waveforms having a 240-s (and 1200-s) sinusoidal period and amplitudes over 10 min (1 h) that exceed a once-per-century threshold. As a result of the combination of geographic differences in geomagnetic variation and Earth-surface impedance, once-per-century geoelectric amplitudes span more than two orders of magnitude and are a highly granular function of location. Specifically for north-south 240-s induction, once-per-century geoelectric amplitudes across large parts of the United States have a median value of 0.34 V/km; for east-west variation, they have a median value of 0.23 V/km. In Northern Minnesota, amplitudes exceed 14.00 V/km for north-south geomagnetic variation (23.34 V/km for east-west variation), while just over 100 km away, amplitudes are only 0.08 V/km (0.02 V/km). At some sites in the northern-central United States, once-per-century geoelectric amplitudes exceed the 2 V/km realized in Québec during the March 1989 storm.

Twilight ozone measurement by solar occultation from AE 5

NASA Technical Reports Server (NTRS)

Guenther, B.; Heath, D.; Dasgupta, R.

1977-01-01

The BUV on AE 5 was used for a solar occultation measurement of atmospheric ozone. An observation was carried out during the morning twilight near 5 deg N, December 17, 1976, at the fixed wavelength of 255.5 nm, and a profile between 49 and 82 km was obtained. The number densities determined by this measurement were 3.7 x 10 to the 10th cu cm at 50 km, 5.1 x 10 to the 9th at 60 km, 3.9 x 10 to the 8th at 70 km, and 3.0 x 10 to the 7th at 80 km. No evidence of a high altitude secondary maximum was found. These concentrations are between a factor of 4 and 20 smaller than those midnight results reported from a Copernicus measurement, and similar to the values from the Krueger-Minzer Mid-latitude Model above 55 km. These values may be as much as a factor of 2 less than the Krueger-Minzer model below 50.

Diverse strategies for ion regulation in fish collected from the ion-poor, acidic Rio Negro.

PubMed

Gonzalez, R J; Wilson, R W; Wood, C M; Patrick, M L; Val, A L

2002-01-01

We measured unidirectional ion fluxes of fish collected directly from the Rio Negro, an extremely dilute, acidic blackwater tributary of the Amazon. Kinetic analysis of Na(+) uptake revealed that most species had fairly similar J(max) values, ranging from 1,150 to 1,750 nmol g(-1) h(-1), while K(m) values varied to a greater extent. Three species had K(m) values <33 micromol L(-1), while the rest had K(m) values >or=110 micromol L(-1). Because of the extremely low Na(+) concentration of Rio Negro water, the differences in K(m) values yield very different rates of Na(+) uptake. However, regardless of the rate of Na(+) uptake, measurements of Na(+) efflux show that Na(+) balance was maintained at very low Na(+) levels (<50 micromol L(-1)) by most species. Unlike other species with high K(m) values, the catfish Corydoras julii maintained high rates of Na(+) uptake in dilute waters by having a J(max) value at least 100% higher than the other species. Corydoras julii also demonstrated the ability to modulate kinetic parameters in response to changes in water chemistry. After 2 wk in 2 mmol L(-1) NaCl, J(max) fell >50%, and K(m) dropped about 70%. The unusual acclimatory drop in K(m) may represent a mechanism to ensure high rates of Na(+) uptake on return to dilute water. As well as being tolerant of extremely dilute waters, Rio Negro fish generally were fairly tolerant of low pH. Still, there were significant differences in sensitivity to pH among the species on the basis of degree of stimulation of Na(+) efflux at low pH. There were also differences in sensitivity to low pH of Na(+) uptake, and two species maintained significant rates of uptake even at pH 3.5. When fish were exposed to low pH in Rio Negro water instead of deionized water (with the same concentrations of major ions), the effects of low pH were reduced. This suggests that high concentrations of dissolved organic molecules in the water, which give it its dark tea color, may interact with the branchial epithelium in some protective manner.

Single-dish high sensitivity determination of solar limb emission at 22 and 44 GHz

NASA Technical Reports Server (NTRS)

Costa, J. E. R.; Homor, J. L.; Kaufmann, P.

1986-01-01

A large number of solar maps were obtained with the use of Itapetinga 45 ft antenna at 22 GHz and 44 GHz. A statistical study of these maps, reduced using original techniques, permitted the establishment of the solar radius with great accuracy at the two frequencies. It is found that 22 GHz and 44 BHz radiation originates at 16,00 km and 12,500 km above the photosphere, respectively. Excess emission due to active regions was clearly identified at lower solar latitudes above and below the equator, extending up to 26,000 km and 16,500 km above the photosphere, at 22 GHs and 44 GHz, respectively.

Ketopantoyl-lactone reductase from Candida parapsilosis: purification and characterization as a conjugated polyketone reductase.

PubMed

Hata, H; Shimizu, S; Hattori, S; Yamada, H

1989-02-24

Ketopantoyl-lactone reductase (2-dehydropantoyl-lactone reductase, EC 1.1.1.168) was purified and crystallized from cells of Candida parapsilosis IFO 0708. The enzyme was found to be homogeneous on ultracentrifugation, high-performance gel-permeation liquid chromatography and SDS-polyacrylamide gel electrophoresis. The relative molecular mass of the native and SDS-treated enzyme is approximately 40,000. The isoelectric point of the enzyme is 6.3. The enzyme was found to catalyze specifically the reduction of a variety of natural and unnatural polyketones and quinones other than ketopantoyl lactone in the presence of NADPH. Isatin and 5-methylisatin are rapidly reduced by the enzyme, the Km and Vmax values for isatin being 14 microM and 306 mumol/min per mg protein, respectively. Ketopantoyl lactone is also a good substrate (Km = 333 microM and Vmax = 481 mumol/min per mg protein). Reverse reaction was not detected with pantoyl lactone and NADP+. The enzyme is inhibited by quercetin, several polyketones and SH-reagents. 3,4-Dihydroxy-3-cyclobutene-1,2-dione, cyclohexenediol-1,2,3,4-tetraone and parabanic acid are uncompetitive inhibitors for the enzyme, the Ki values being 1.4, 0.2 and 3140 microM, respectively, with isatin as substrate. Comparison of the enzyme with the conjugated polyketone reductase of Mucor ambiguus (S. Shimizu, H. Hattori, H. Hata and H. Yamada (1988) Eur. J. Biochem. 174, 37-44) and ketopantoyl-lactone reductase of Saccharomyces cerevisiae suggested that ketopantoyl-lactone reductase is a kind of conjugated polyketone reductase.

Persistent organic pollutants in fish tissue in the mid-continental great rivers of the United States

USGS Publications Warehouse

Blacksom, Karen A.; Walters, David M.; Jicha, Terri M.; Lazorchak, James M.; Angradi, Theodore R.; Bolgrien, David W.

2010-01-01

Great rivers of the central United States (Upper Mississippi, Missouri, and Ohio rivers) are valuable economic and cultural resources, yet until recently their ecological condition has not been well quantified. In 2004–2005, as part of the Environmental Monitoring and Assessment Program for Great River Ecosystems (EMAP-GRE), we measured legacy organochlorines (OCs) (pesticides and polychlorinated biphenyls, PCBs) and emerging compounds (polybrominated diphenyl ethers, PBDEs) in whole fish to estimate human and wildlife exposure risks from fish consumption. PCBs, PBDEs, chlordane, dieldrin and dichlorodiphenyltrichloroethane (DDT) were detected in most samples across all rivers, and hexachlorobenzene was detected in most Ohio River samples. Concentrations were highest in the Ohio River, followed by the Mississippi and Missouri Rivers, respectively. Dieldrin and PCBs posed the greatest risk to humans. Their concentrations exceeded human screening values for cancer risk in 27–54% and 16–98% of river km, respectively. Chlordane exceeded wildlife risk values for kingfisher in 11–96% of river km. PBDE concentrations were highest in large fish in the Missouri and Ohio Rivers (mean > 1000 ng g−1 lipid), with congener 47 most prevalent. OC and PBDE concentrations were positively related to fish size, lipid content, trophic guild, and proximity to urban areas. Contamination of fishes by OCs is widespread among great rivers, although exposure risks appear to be more localized and limited in scope. As an indicator of ecological condition, fish tissue contamination contributes to the overall assessment of great river ecosystems in the U.S.

Characterization of two Streptomyces enzymes that convert ferulic acid to vanillin.

PubMed

Yang, Wenwen; Tang, Hongzhi; Ni, Jun; Wu, Qiulin; Hua, Dongliang; Tao, Fei; Xu, Ping

2013-01-01

Production of flavors from natural substrates by microbial transformation has become a growing and expanding field of study over the past decades. Vanillin, a major component of vanilla flavor, is a principal flavoring compound used worldwide. Streptomyces sp. strain V-1 is known to be one of the most promising microbial producers of natural vanillin from ferulic acid. Although identification of the microbial genes involved in the biotransformation of ferulic acid to vanillin has been previously reported, purification and detailed characterization of the corresponding enzymes with important functions have rarely been studied. In this study, we isolated and identified 2 critical genes, fcs and ech, encoding feruloyl-CoA synthetase and enoyl-CoA hydratase/aldolase, respectively, which are involved in the vanillin production from ferulic acid. Both genes were heterologously expressed in Escherichia coli, and the resting cell reactions for converting ferulic acid to vanillin were performed. The corresponding crucial enzymes, Fcs and Ech, were purified for the first time and the enzymatic activity of each purified protein was studied. Furthermore, Fcs was comprehensively characterized, at an optimal pH of 7.0 and temperature of 30°C. Kinetic constants for Fcs revealed the apparent Km, kcat, and Vmax values to be 0.35 mM, 67.7 s(-1), and 78.2 U mg(-1), respectively. The catalytic efficiency (kcat/Km) value of Fcs was 193.4 mM(-1) s(-1) for ferulic acid. The characterization of Fcs and Ech may be helpful for further research in the field of enzymatic engineering and metabolic regulation.

A Chlorogenic Acid Esterase with a Unique Substrate Specificity from Ustilago maydis

PubMed Central

Haase-Aschoff, Paul; Kelle, Sebastian; Linke, Diana; Krings, Ulrich; Popper, Lutz; Berger, Ralf G.

2014-01-01

An extracellular chlorogenic acid esterase from Ustilago maydis (UmChlE) was purified to homogeneity by using three separation steps, including anion-exchange chromatography on a Q Sepharose FF column, preparative isoelectric focusing (IEF), and, finally, a combination of affinity chromatography and hydrophobic interaction chromatography on polyamide. SDS-PAGE analysis suggested a monomeric protein of ∼71 kDa. The purified enzyme showed maximal activity at pH 7.5 and at 37°C and was active over a wide pH range (3.5 to 9.5). Previously described chlorogenic acid esterases exhibited a comparable affinity for chlorogenic acid, but the enzyme from Ustilago was also active on typical feruloyl esterase substrates. Kinetic constants for chlorogenic acid, methyl p-coumarate, methyl caffeate, and methyl ferulate were as follows: Km values of 19.6 μM, 64.1 μM, 72.5 μM, and 101.8 μM, respectively, and kcat/Km values of 25.83 mM−1 s−1, 7.63 mM−1 s−1, 3.83 mM−1 s−1 and 3.75 mM−1 s−1, respectively. UmChlE released ferulic, p-coumaric, and caffeic acids from natural substrates such as destarched wheat bran (DSWB) and coffee pulp (CP), confirming activity on complex plant biomass. The full-length gene encoding UmChlE consisted of 1,758 bp, corresponding to a protein of 585 amino acids, and was functionally produced in Pichia pastoris GS115. Sequence alignments with annotated chlorogenic acid and feruloyl esterases underlined the uniqueness of this enzyme. PMID:25548041

The 1992 Tafilalt seismic crisis (Anti-Atlas, Morocco)

NASA Astrophysics Data System (ADS)

Bensaid, Ihsane; Cherkaoui, Taj-Eddine; Medina, Fida; Caldeira, Bento; Buforn, Elisa; Emran, Anas; Hahou, Youssef

2012-01-01

The Tafilalt region, located at the eastern end of the Anti-Atlas chain in Morocco, was shaken on 23 and 30 October 1992 by two moderate earthquakes of magnitude mb ˜ 5 and intensity ˜ VI MSK64, which caused two deaths and great damage in the area between Erfoud and Rissani. The review of data available on the seismic crisis allowed us to improve the knowledge on the macroseismic, instrumental and source parameters of the earthquakes. The main results of the present study are: (1) location of the epicentres with the help of data from a close portable network allowed us to propose new epicentral coordinates at 31.361° N, 4.182° W (23 October) and 31.286° N, 4.347° W (30 October); both events have focal depths of 2 km; (2) the shock of 30 October was followed by a series of 305 aftershocks, most of which were located west of Rissani; the 61 best-constrained events had focal depths of 5 to 19 km and magnitudes 0.7 to 3; (3) the largest damage was located in an area between the two epicentres within the Tafilalt valley and was probably amplified by site effects due to the proximity of the water table within the Quaternary sediments; (4) focal mechanisms of the main events correspond to strike-slip faulting with fault planes oriented N-S (left lateral) and E-W (right lateral); the only mechanism available for the aftershocks also corresponds to strike-slip faulting; (5) spectral analysis shows that the scalar seismic moment ( Mo) of the first event is slightly larger than the second; the corresponding values of Mw are 5.1 and 5.0, respectively; (6) the dimensions of the faults for a circular fault model are 7.7 ± 1.4 and 7.4 ± 1.2 km, respectively; the average displacement is 4 cm for the first event and 3.7 cm for the second; the stress drop is 0.4 and 0.3 MPa, respectively, in agreement with standard values; (7) the Coulomb Stress test performed for both earthquakes suggests a relationship between both events only when the used location is at the limit of the horizontal uncertainty; (8) finally, the occurrence of these shocks suggests that the Anti-Atlas is undergoing tectonic deformation in addition to thermal uplift as suggested by recent publications.

Kinetics of 3H-serotonin uptake by platelets in infantile autism and developmental language disorder (including five pairs of twins)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katsui, T.; Okuda, M.; Usuda, S.

The kinetics of 5-HT uptake by platelets was studied in cases of infantile autism and developmental language disorder (DLD) and normal subjects. Two patients of the autism group were twins, and the seven patients of the DLD group were members of four pairs of twins. The Vmax values (means +/- SD) for autism and DLD were 6.46 +/- .90 pmol 5-HT/10(7) cells/min and 4.85 +/- 1.50 pmol 5-HT/10(7) cells/min, respectively. These values were both significantly higher than that of 2.25 +/- .97 pmole 5-HT/10(7) cells/min for normal children. The Km values of the three groups were not significantly different. Datamore » on the five pairs of twins examined suggested that the elevated Vmax of 5-HT uptake by platelets was determined genetically.« less

Investigations on the links between rain intensity or reflectivity structures estimated from radar and drop size distributions

NASA Astrophysics Data System (ADS)

Hachani, Sahar; Boudevillain, Brice; Bargaoui, Zoubeida; Delrieu, Guy

2015-04-01

During the first Special Observation Period (SOP) of the Hydrological cycle in the Mediterranean Experiment (HyMeX, www.hymex.org) held in fall 2012 in the Northwestern Mediterranean region, an observation network dedicated to rain studies was implemented in the Cévennes region, France. It was mainly constituted by weather radars, micro rain radars, disdrometers and rain gauges. Observations are performed by a network of 25 OTT Parsivel optical disdrometers distributed with inter-distances ranging from a few meters up to about one hundred kilometers. This presentation focuses on the comparison of one optical disdrometer observations located at Villeneuve-de-berg to observations using weather Météo-France / ARAMIS radar located at Bollène which is in a neighborhood of 60 km from the disdrometer.The period from September to November 2012 is studied. To analyze the structure of the rain observed by radar, a window of investigation centered on the disdrometer was selected and the mean spatial values, standard deviation, gradients, and intermittency of radar reflectivity or rainfall intensity were computed for a time step of 5 minutes.Four different windowsizes were analyzed: 1 km², 25 km², 100 km² and 400 km². On the other hand, the total concentration of drops Nt, the characteristic diameter of drops Dc, and a Gamma distribution shape parameter µ were estimated. Gamma distribution for the DSD related to disdrometer observations was estimated according to the modeling framework proposed by Yu et al. (2014). Correlation coefficient between intensity R obtained by the disdrometer and windowaverage R estimated using radar data is nearly 0.70 whatever the window. The highest value is found for the window 25 km² (0.74). Correlation coefficients between Dc and window average R vary from 0.35 for the window 1 km² to 0.4 for the window 400 km². So, they areweak and not sensitive to the choice of the window. Contrarily, formean radar reflectivityZ, correlation coefficients with Dc, Nt and µ vary to some extent from the window size 1 km² to the window size 100 km². The most sensitive is the correlation coefficient between Z and Nt. However it presents the smallest correlations while the highest correlations are found for Dc (respectively 0.80 and 0.74). The overall of relations between the rainfall structure variables and DSD parameters will be presented in the communication with a special attention to the weather and/or rainfall types (orographic, stratiform, and convective). References: Yu, N., Delrieu, G., Boudevillain, B., Hazenberg, P., and Uijlenhoet, R., 2014: Unified formulation of single and multi-moment normalizations of the raindrop size distribution based on the gamma probability density function. Journal of Applied Meteorology and Climatology, 53, pp 166-179.

A Technique for Mapping Mangroves with Landsat TM Satellite Data and Geographic Information System

NASA Astrophysics Data System (ADS)

Long, Brian G.; Skewes, Timothy D.

1996-09-01

The mangroves in a 2845 km 2area in the Southern Gulf of Carpentaria, Australia, were mapped from Landsat TM satellite data. The mangroves were mapped by selecting 10 training set areas in dense mangrove (100% cover), and using the maximum and minimum training set values for green, red, near-infra-red (NIR) and NIR/red to map the remaining mangroves. The accuracy of the map was improved by using ecological information about mangroves—they are found in tidally inundated areas—to derive simple rules in a Geographic Information System, to subdivide the areas labelled ' mangrove ' from image processing of satellite data on the basis of nearness to water (next to water and not adjoining water), ground elevation [higher and lower than 10 m above mean sea level (MSL)] and distance from water (>2 and <2 km). Each zone was cross-checked with 1:50 000 panchromatic aerial photographs. Zones that were still mixed vegetation after applying these simple rules were further subdivided by eye. This process resulted in a map with zones identified as either 100% mangrove or 0% mangrove. The areas that were identified as mangrove were also subdivided on the basis of the three main river systems in the study area. The Norman, Bynoe and Flinders Rivers had 40·86, 10·09 and 5·42 km 2of mangroves, respectively. These areas combined with the 9·89 km 2of coastal mangrove to give a total of 66·25 km 2of mangrove in the study area.

Purification and kinetic analysis of cytosolic and mitochondrial thioredoxin glutathione reductase extracted from Taenia solium cysticerci.

PubMed

Plancarte, Agustin; Nava, Gabriela

2015-02-01

Thioredoxin glutathione reductases (TGRs) (EC 1.8.1.9) were purified to homogeneity from the cytosolic (cTsTGR) and mitochondrial (mTsTGR) fractions of Taenia solium, the agent responsible for neurocysticercosis, one of the major central nervous system parasitic diseases in humans. TsTGRs had a relative molecular weight of 132,000, while the corresponding value per subunit obtained under denaturing conditions, was of 62,000. Specific activities for thioredoxin reductase and glutathione reductase substrates for both TGRs explored were in the range or lower than values obtained for other platyhelminths and mammalian TGRs. cTsTGR and mTsTGR also showed hydroperoxide reductase activity using hydroperoxide as substrate. Km(DTNB) and Kcat(DTNB) values for cTsTGR and mTsTGR (88 µM and 1.9 s(-1); 45 µM and 12.6 s(-1), respectively) and Km(GSSG) and Kcat(GSSG) values for cTsTGR and mTsTGR (6.3 µM and 0.96 s(-1); 4 µM and 1.62 s(-1), respectively) were similar to or lower than those reported for mammalian TGRs. Mass spectrometry analysis showed that 12 peptides from cTsTGR and seven from mTsTGR were a match for gi|29825896 thioredoxin glutathione reductase [Echinococcus granulosus], confirming that both enzymes are TGRs. Both T. solium TGRs were inhibited by the gold compound auranofin, a selective inhibitor of thiol-dependent flavoreductases (I₅₀ = 3.25, 2.29 nM for DTNB and GSSG substrates, respectively for cTsTGR; I₅₀ = 5.6, 25.4 nM for mTsTGR toward the same substrates in the described order). Glutathione reductase activity of cTsTGR and mTsTGR exhibited hysteretic behavior with moderate to high concentrations of GSSG; this result was not observed either with thioredoxin, DTNB or NADPH. However, the observed hysteretic kinetics was suppressed with increasing amounts of both parasitic TGRs. These data suggest the existence of an effective substitute which may account for the lack of the detoxification enzymes glutathione reductase and thioredoxin reductase in T. solium, as has been described for very few other platyhelminths. Copyright © 2014 Elsevier Inc. All rights reserved.

Highly Efficient Synthesis of Fructooligosaccharides by Extracellular Fructooligosaccharide-Producing Enzymes and Immobilized Cells of Aspergillus aculeatus M105 and Purification and Biochemical Characterization of a Fructosyltransferase from the Fungus.

PubMed

Huang, Mei-Ping; Wu, Min; Xu, Qiang-Sheng; Mo, De-Jiao; Feng, Jia-Xun

2016-08-24

In this work, Aspergillus aculeatus M105 was obtained to produce high extracellular fructooligosaccharide-producing enzyme activity. The maximum yields of fructooligosaccharides produced by its extracellular enzymes and immobilized cells were 67.54 and 65.47% (w/w), respectively. A fructosyltransferase (FTase), AaFT32A, was purified from M105. The optimal pH and temperature of AaFT32A were pH 5.0-6.0 and 65 °C, respectively. The Km, Vmax, and kcat values for the transfructosylating activity of AaFT32A were 2267 mM, 1347 μmol/min/mg protein, and 1550.2 s(-1), respectively, and those values for the hydrolytic activity of AaFT32A were 6.10 mM, 32.44 μmol/min/mg protein, and 37.3 s(-1), respectively. The sequence of AaFT32A deduced from the cloned gene shared 99.4% identity with a FTase from Aspergillus japonicus CB05 and a fructofuranosidase from Aspergillus niger and 96.5% identity with a FTase (Aspacl_37092) from A. aculeatus ATCC 16872. The fungal strain and its FTase may have potential applications in the prebiotics industry.

Solar flare induced ionospheric D-region enhancements from VLF amplitude observations

NASA Astrophysics Data System (ADS)

Thomson, N. R.; Clilverd, M. A.

2001-11-01

Enhancements of D-region electron densities caused by solar flares are determined from observations of VLF subionospheric amplitude changes and these enhancements are then related to the magnitudes of the X-ray fluxes measured by the GOES satellites. The electron densities are characterised by the two traditional parameters, /H' and /β (being measures of the ionospheric height and the rate of increase of electron density with height, respectively), which are found by VLF radio modelling of the observed amplitudes using the NOSC Earth-ionosphere waveguide programs (LWPC and Modefinder) mainly on two paths, one short and one long. The short path measurements were made near Cambridge, UK, on the 18.3kHz signals from the French transmitter 617km to the south while the long path measurements were made near Dunedin, NZ, on the 24.8kHz signals from NLK in Seattle, USA, 12.3Mm across the Pacific Ocean. The observations include flares up to a magnitude of about M5 (5×10-5Wm-2 at 0.1-0.8nm) which gave VLF amplitude enhancements up to about 8dB; these corresponded, under near solar maximum conditions (1992), to a reduction in /H' from about 71km down to about 63km and an increase in /β from 0.43km-1 up to about 0.49km-1. The increased values of /β during a flare are caused by the solar X-rays dominating all sources of ionisation during the flare in contrast with the normal unperturbed daytime values of /β which are significantly lower than for a single solar UV or X-ray source due to the extra electrons from the normal galactic cosmic ray ionisation in the lowest parts of the D-region. This steady, normal (unperturbed) cosmic ray influence on /β, and hence unperturbed VLF attenuation, is more marked at times of reduced solar Lyman-/α flux in the D-region such as at solar minimum, high latitudes or early or late in the day, thus explaining the normal (unperturbed) higher VLF attenuation rates previously reported in these conditions.

H0 from cosmic chronometers and Type Ia supernovae, with Gaussian Processes and the novel Weighted Polynomial Regression method

NASA Astrophysics Data System (ADS)

Gómez-Valent, Adrià; Amendola, Luca

2018-04-01

In this paper we present new constraints on the Hubble parameter H0 using: (i) the available data on H(z) obtained from cosmic chronometers (CCH); (ii) the Hubble rate data points extracted from the supernovae of Type Ia (SnIa) of the Pantheon compilation and the Hubble Space Telescope (HST) CANDELS and CLASH Multy-Cycle Treasury (MCT) programs; and (iii) the local HST measurement of H0 provided by Riess et al. (2018), H0HST=(73.45±1.66) km/s/Mpc. Various determinations of H0 using the Gaussian processes (GPs) method and the most updated list of CCH data have been recently provided by Yu, Ratra & Wang (2018). Using the Gaussian kernel they find H0=(67.42± 4.75) km/s/Mpc. Here we extend their analysis to also include the most released and complete set of SnIa data, which allows us to reduce the uncertainty by a factor ~ 3 with respect to the result found by only considering the CCH information. We obtain H0=(67.06± 1.68) km/s/Mpc, which favors again the lower range of values for H0 and is in tension with H0HST. The tension reaches the 2.71σ level. We round off the GPs determination too by taking also into account the error propagation of the kernel hyperparameters when the CCH with and without H0HST are used in the analysis. In addition, we present a novel method to reconstruct functions from data, which consists in a weighted sum of polynomial regressions (WPR). We apply it from a cosmographic perspective to reconstruct H(z) and estimate H0 from CCH and SnIa measurements. The result obtained with this method, H0=(68.90± 1.96) km/s/Mpc, is fully compatible with the GPs ones. Finally, a more conservative GPs+WPR value is also provided, H0=(68.45± 2.00) km/s/Mpc, which is still almost 2σ away from H0HST.

Systematic heat flow measurements across the Wagner Basin, northern Gulf of California

NASA Astrophysics Data System (ADS)

Neumann, Florian; Negrete-Aranda, Raquel; Harris, Robert N.; Contreras, Juan; Sclater, John G.; González-Fernández, Antonio

2017-12-01

A primary control on the geodynamics of rifting is the thermal regime. To better understand the geodynamics of rifting in the northern Gulf of California we systematically measured heat-flow across the Wagner Basin, a tectonically active basin that lies near the southern terminus of the Cerro Prieto fault. The heat flow profile is 40 km long, has a nominal measurement spacing of ∼1 km, and is collocated with a seismic reflection profile. Heat flow measurements were made with a 6.5-m violin-bow probe. Although heat flow data were collected in shallow water, where there are significant temporal variations in bottom water temperature, we use CTD data collected over many years to correct our measurements to yield accurate values of heat flow. After correction for bottom water temperature, the mean and standard deviation of heat flow across the western, central, and eastern parts of the basin are 220 ± 60, 99 ± 14, 889 ± 419 mW m-2, respectively. Corrections for sedimentation would increase measured heat flow across the central part of basin by 40 to 60%. We interpret the relatively high heat flow and large variability on the western and eastern flanks in terms of upward fluid flow at depth below the seafloor, whereas the lower and more consistent values across the central part of the basin are suggestive of conductive heat transfer. Moreover, heat flow across the central basin is consistent with gabbroic underplating at a depth of 15 km and suggests that continental rupture here has not gone to completion.

Boundary-Layer Edge Conditions and Transition Reynolds Number Data for a Flight Test at Mach 20 (Reentry F)

NASA Technical Reports Server (NTRS)

Johnson, Charles B.; Stainback, P. Calvin; Wicker, Kathleen C.; Boney, Lillian R.

1972-01-01

A flight experiment, designated Reentry F, was conducted to measure heat-transfer rates for laminar, transitional, and turbulent boundary layers on a 5 deg half-angle cone 3.962 m (13 ft) long with a preflight nose radius of 2.54 mm (0.10 in.). Data were obtained over an altitude range from 36.58 to 18.29 km (120 000 to 60 000 ft) at a flight velocity of about 6.096 km/sec (20 000 ft/sec). The nominal values of the free-stream total enthalpy, sharp-cone Mach number, and the wall-to-total enthalpy ratio were 18 MJ/kg (8000 Btu/lb), 15, and 0.03, respectively. Calculated boundary-layer edge conditions that account for effects of the entropy layer and corresponding local transition Reynolds numbers are reported in the present paper. Fully developed turbulent flow occurred with essentially constant boundary-layer edge conditions near the sharp-cone values. Transition data were obtained with local edge Mach numbers ranging from about 5.55 to 15. Transition Reynolds numbers, based on local condition, were as high as 6.6 x 10(exp 7) with an edge Mach number of about 14.4 at an altitude of 24.38 km (80 000 ft). The transition could be correlated with previous flight data taken over a Mach number range from 3 to 12 in terms of parameters including the effects of local unit Reynolds number, boundary-layer wall-to-edge enthalpy ratio, and local Mach number.

A record of more than 500,000 years of large-volume travertine formation in the southwestern United States and links between paleohydrology, paleoclimate, and landscape evolution

NASA Astrophysics Data System (ADS)

Priewisch, A.; Crossey, L. J.; Embid, E.; Karlstrom, K. E.; Polyak, V.; Asmerom, Y.; Ricketts, J. W.

2011-12-01

CO2 springs and associated travertine deposits offer a unique tool to better understand Cenozoic paleohydrology and paleoclimate in the context of geomorphic and neotectonic evolution of the southwestern United States. Travertine accumulations represent places of persistent and significant mantle CO2 degassing in high discharge spring systems that are found along faults and above magmatic systems. They complement speleothem records from the same regions in that they can provide better links to the surface geomorphic and neotectonic systems. New Mexico and Arizona host several exceptionally well-preserved, large-volume travertine deposits that extend from 10 - 60 km2, with thicknesses ranging from 15 to more than 60 m. Precise U-series and stable isotope analyses are underway for large travertine platforms at Mesa del Oro, NM (~27 km2), Riley North and South Mesa, NM (~60 km2), Mesa Aparejo/Belen Quarries, NM (~13 km2), and Springerville, AZ (~30 km2). New ages for the travertine deposits at Mesa del Oro are 56 ka, 253 ka, 361 ka, and more than 500 ka. The travertine deposits at Riley North and South Mesa are older than 500 ka and 207/287 ka, respectively. At Mesa Aparejo, travertine ages are 312 ka and more than 500 ka. U/Th dates from Springerville, AZ show that major travertine accumulations occurred over several time intervals: 36-100 ka, 200-280 ka and 300-350 ka. Stable isotope analyses overlap substantially, exhibiting high δ13C values, +2.0% to +8.3%, and δ18O values that range from -13.5% to -4%. High δ13C values are interpreted to be caused by rapid CO2 degassing while the range of δ18O values is interpreted to represent changing water temperatures and mixing trends of groundwater. U-series data show that travertine deposition at all of these localities overlapped temporally and that major aggradation and high volume deposition was not steady, but occurred episodically at 36-100, 200-280, and 300-380 ka. Times of high accumulation rates are interpreted as times of high groundwater flow and hence as a proxy for regional paleohydrology/paleoclimate controls while the locations of the travertine occurrences (along faults of the Jemez lineament and Rio Grande rift) reflect more local CO2-discharge (tectonic) controls. These travertine occurrences are important indicators of the extent of past natural CO2 leakage that can inform carbon sequestration models both in areas of modern CO2 gas fields (Springerville) and at sites of potential paleo-gas fields. The travertine platforms now occupy positions high in the landscape (inverted topography) and also provide data on the scales and timing of regional landscape denudation.

Spatio-temporal analysis of Modified Omori law in Bayesian framework

NASA Astrophysics Data System (ADS)

Rezanezhad, V.; Narteau, C.; Shebalin, P.; Zoeller, G.; Holschneider, M.

2017-12-01

This work presents a study of the spatio temporal evolution of the modified Omori parameters in southern California in then time period of 1981-2016. A nearest-neighbor approach is applied for earthquake clustering. This study targets small mainshocks and corresponding big aftershocks ( 2.5 ≤ mmainshocks ≤ 4.5 and 1.8 ≤ maftershocks ≤ 2.8 ). We invert for the spatio temporal behavior of c and p values (especially c) all over the area using a MCMC based maximum likelihood estimator. As parameterizing families we use Voronoi cells with randomly distributed cell centers. Considering that c value represents a physical character like stress change we expect to see a coherent c value pattern over seismologically coacting areas. This correlation of c valus can actually be seen for the San Andreas, San Jacinto and Elsinore faults. Moreover, the depth dependency of c value is studied which shows a linear behavior of log(c) with respect to aftershock's depth within 5 to 15 km depth.

Lectins as endocytic ligands: an assessment of lectin binding and uptake to rabbit conjunctival epithelial cells.

PubMed

Qaddoumi, Mohamed; Lee, Vincent H L

2004-07-01

To investigate the binding and uptake pattern of three plant lectins in rabbit conjunctival epithelial cells (RCECs) with respect to their potential for enhancing cellular macromolecular uptake. Three fluorescein-labeled plant lectins (Lycoperison esculentum, TL; Solanum tuberosum, STL; and Ulex europaeus 1, UEA-1) were screened with respect to time-, concentration-, and temperature-dependent binding and uptake. Chitin (30 mg/ml) and L-alpha-fucose (10 mM) were used as inhibitory sugars to correct for nonspecific binding of TL or STL and UEA-1, respectively. Confocal microscopy was used to confirm internalization of STL. The binding and uptake of all three lectins in RCECs was time-dependent (reaching a plateau at 1-2 h period) and saturable at 1-h period. The rank order of affinity constants (km) was STL>TL>UEA-1 with values of 0.39>0.48>4.81 microM, respectively. However, maximal, specific binding/uptake potential was in the order UEA-1>STL>TL with values of 53.7, 52.3, and 15.0 nM/mg of cell protein, respectively. Lectins showed temperature dependence in their uptake, with STL exhibiting the highest endocytic capacity. Internalized STL was visualized by confocal microscopy to be localized to the cell membrane and cytoplasm. Based on favorable binding and uptake characteristics, potato lectin appears to be a useful candidate for further investigation as an ocular drug delivery system.

GRAM 88 - 4D GLOBAL REFERENCE ATMOSPHERE MODEL-1988

NASA Technical Reports Server (NTRS)

Johnson, D. L.

1994-01-01

The Four-D Global Reference Atmosphere program was developed from an empirical atmospheric model which generates values for pressure, density, temperature, and winds from surface level to orbital altitudes. This program can generate altitude profiles of atmospheric parameters along any simulated trajectory through the atmosphere. The program was developed for design applications in the Space Shuttle program, such as the simulation of external tank re-entry trajectories. Other potential applications are global circulation and diffusion studies; also the generation of profiles for comparison with other atmospheric measurement techniques such as satellite measured temperature profiles and infrasonic measurement of wind profiles. GRAM-88 is the latest version of the software GRAM. The software GRAM-88 contains a number of changes that have improved the model statistics, in particular, the small scale density perturbation statistics. It also corrected a low latitude grid problem as well as the SCIDAT data base. Furthermore, GRAM-88 now uses the U.S. Standard Atmosphere 1976 as a comparison standard rather than the US62 used in other versions. The program is an amalgamation of two empirical atmospheric models for the low (25km) and the high (90km) atmosphere, with a newly developed latitude-longitude dependent model for the middle atmosphere. The Jacchia (1970) model simulates the high atmospheric region above 115km. The Jacchia program sections are in separate subroutines so that other thermosphericexospheric models could easily be adapted if required for special applications. The improved code eliminated the calculation of geostrophic winds above 125 km altitude from the model. The atmospheric region between 30km and 90km is simulated by a latitude-longitude dependent empirical model modification of the latitude dependent empirical model of Groves (1971). A fairing technique between 90km and 115km accomplished a smooth transition between the modified Groves values and the Jacchia values. Below 25km the atmospheric parameters are computed by the 4-D worldwide atmospheric model of Spiegler and Fowler (1972). This data set is not included. GRAM-88 incorporates a hydrostatic/gas law check in the 0-30 km altitude range to flag and change any bad data points. Between 5km and 30km, an interpolation scheme is used between the 4-D results and the modified Groves values. The output parameters consist of components for: (1) latitude, longitude, and altitude dependent monthly and annual means, (2) quasi-biennial oscillations (QBO), and (3) random perturbations to partially simulate the variability due to synoptic, diurnal, planetary wave, and gravity wave variations. Quasi-biennial and random variation perturbations are computed from parameters determined by various empirical studies and are added to the monthly mean values. The GRAM-88 program is for batch execution on the IBM 3084. It is written in STANDARD FORTRAN 77 under the MVS/XA operating system. The IBM DISPLA graphics routines are necessary for graphical output. The program was developed in 1988.

Observational Characteristics of the Tropopause Inversion Layer derived from CHAMP/GRACE Radio Occultations and MOZAIC Aircraft Data

NASA Astrophysics Data System (ADS)

Schmidt, T.; Cammas, J.; Heise, S.; Wickert, J.; Haser, A.

2010-12-01

In this study we discuss characteristics of the northern hemisphere (NH) midlatitude (40°N-60°N) tropopause inversion layer (TIL) based on two datasets. First, temperature measurements from GPS radio occultation data (CHAMP and GRACE) for the time interval 2001-2009 are used to exhibit seasonal properties of the TIL bottom height defined here as the height of the squared buoyancy frequency minimum N2 below the thermal tropopause, the TIL maximum height as the height of the N2 maximum above the tropopause and the TIL top height as the height of the temperature maximum above the tropopause. Mean values of the TIL bottom, TIL maximum and TIL top heights relative to the thermal tropopause for the NH midlatitudes are (-2.08±0.35) km, (0.52±0.10) km and (2.10±0.23) km, respectively. A seasonal cycle of the TIL bottom and TIL top height is observed with values closer to the thermal tropopause during summer. Secondly, high-resolution temperature and trace gas profile measurements onboard commercial aircrafts (MOZAIC program) from 2001-2008 for the NH midlatitude (40°N-60°N) region are used to characterize the TIL as a mixing layer around the tropopause. Mean TIL bottom, TIL maximum and TIL top heights based on the MOZAIC temperature (N2) measurements confirm the results from the GPS data, even though most of the MOZAIC profiles used here are available under cyclonic situations. Further, we demonstrate that the mixing ratio gradients of ozone (O3) and carbon monoxide (CO) are suitable parameters for characterizing the TIL structure. Using O3-CO correlations we also show that on average the highest mixing occurs in a layer less than 1 km above the thermal tropopause, i.e., within the TIL.

Meteorological modeling of arrival and deposition of fallout at intermediate distances downwind of the Nevada Test Site.

PubMed

Cederwall, R T; Peterson, K R

1990-11-01

A three-dimensional atmospheric transport and diffusion model is used to calculate the arrival and deposition of fallout from 13 selected nuclear tests at the Nevada Test Site (NTS) in the 1950s. Results are used to extend NTS fallout patterns to intermediate downwind distances (300 to 1200 km). The radioactive cloud is represented in the model by a population of Lagrangian marker particles, with concentrations calculated on an Eulerian grid. Use of marker particles, with fall velocities dependent on particle size, provides a realistic simulation of fallout as the debris cloud travels downwind. The three-dimensional wind field is derived from observed data, adjusted for mass consistency. Terrain is represented in the grid, which extends up to 1200 km downwind of NTS and has 32-km horizontal resolution and 1-km vertical resolution. Ground deposition is calculated by a deposition-velocity approach. Source terms and relationships between deposition and exposure rate are based on work by Hicks. Uncertainty in particle size and vertical distributions within the debris cloud (and stem) allow for some model "tuning" to better match measured ground-deposition values. Particle trajectories representing different sizes and starting heights above ground zero are used to guide source specification. An hourly time history of the modeled fallout pattern as the debris cloud moves downwind provides estimates of fallout arrival times. Results for event HARRY illustrate the methodology. The composite deposition pattern for all 13 tests is characterized by two lobes extending out to the north-northeast and east-northeast, respectively, at intermediate distances from NTS. Arrival estimates, along with modeled deposition values, augment measured deposition data in the development of data bases at the county level; these data bases are used for estimating radiation exposure at intermediate distances downwind of NTS. Results from a study of event TRINITY are also presented.

Extreme-event geoelectric hazard maps

NASA Astrophysics Data System (ADS)

Love, J. J.; Bedrosian, P.

2017-12-01

Maps covering about half of the continental United States are presented of geoelectric field amplitude that will be exceeded, on average, once per century in response to extreme-intensity geomagnetic disturbance. These maps are constructed using an empirical parameterization of induction: convolving latitude-dependent statistical maps of extreme-value geomagnetic disturbance, obtained from decades of 1-minute magnetic observatory data, with local estimates of Earth-surface impedance, obtained at discrete geographic sites from magnetotelluric surveys. Geoelectric amplitudes are estimated for geomagnetic waveforms having 240-s (and 1200-s) sinusoidal period and amplitudes over 10 minutes (1-hr) that exceed a once-per-century threshold. As a result of the combination of geographic differences in geomagnetic variation and Earth-surface impedance, once-per-century geoelectric amplitudes span more than two orders of magnitude and are a highly granular function of location. Specifically: for north-south 240-s induction, once-per-century geoelectric amplitudes across large parts of the United States have a median value of 0.34 V/km; for east-west variation, they have a median value of 0.23 V/km. In Northern Minnesota, amplitudes exceed 14.00 V/km for north-south geomagnetic variation (23.34 V/km for east-west variation), while just over 100 km away, amplitudes are only 0.08 V/km (0.02 V/km). At some sites in the Northern Central United States, once-per-century geoelectric amplitudes exceed the 2 V/km realized in Quebec during the March 1989 storm. These hazard maps are incomplete over large parts of the United States, including major population centers in the southern United States, due to a lack of publically available impedance data.

Three-dimensional P-wave velocity structure derived from local earthquakes at the Katmai group of volcanoes, Alaska

USGS Publications Warehouse

Jolly, A.D.; Moran, S.C.; McNutt, S.R.; Stone, D.B.

2007-01-01

The three-dimensional P-wave velocity structure beneath the Katmai group of volcanoes is determined by inversion of more than 10,000 rays from over 1000 earthquakes recorded on a local 18 station short-period network between September 1996 and May 2001. The inversion is well constrained from sea level to about 6??km below sea level and encompasses all of the Katmai volcanoes; Martin, Mageik, Trident, Griggs, Novarupta, Snowy, and Katmai caldera. The inversion reduced the average RMS travel-time error from 0.22??s for locations from the standard one-dimensional model to 0.13??s for the best three-dimensional model. The final model, from the 6th inversion step, reveals a prominent low velocity zone (3.6-5.0??km/s) centered at Katmai Pass and extending from Mageik to Trident volcanoes. The anomaly has values about 20-25% slower than velocities outboard of the region (5.0-6.5??km/s). Moderately low velocities (4.5-6.0??km/s) are observed along the volcanic axis between Martin and Katmai Caldera. Griggs volcano, located about 10??km behind (northwest of) the volcanic axis, has unremarkable velocities (5.0-5.7??km/s) compared to non-volcanic regions. The highest velocities are observed between Snowy and Griggs volcanoes (5.5-6.5??km/s). Relocated hypocenters for the best 3-D model are shifted significantly relative to the standard model with clusters of seismicity at Martin volcano shifting systematically deeper by about 1??km to depths of 0 to 4??km below sea level. Hypocenters for the Katmai Caldera are more tightly clustered, relocating beneath the 1912 scarp walls. The relocated hypocenters allow us to compare spatial frequency-size distributions (b-values) using one-dimensional and three-dimensional models. We find that the distribution of b is significantly changed for Martin volcano, which was characterized by variable values (0.8 < b < 2.0) with standard locations and more uniform values (0.8 < b < 1.2) after relocation. Other seismic clusters at Mageik (1.2 < b < 2.2), Trident (0.5 < b < 1.5) and Katmai Caldera (0.8 < b < 1.8) had stable b-values indicating the robustness of the observations. The strong high b-value region at Mageik volcano is mainly associated with an earthquake swarm in October, 1996 that possibly indicates a shallow intrusion or influx of gas. The new velocity and spatial b-value results, in conjunction with prior gravity (Bouguer anomalies up to - 40??mgal) and interferometry (several cm uplift) data, provide strong evidence in favor of partially molten rock at shallow depths beneath the Mageik-Katmai-Novarupta region. Moderately low velocities beneath Martin and Katmai suggest that old, mostly solidified intrusions exist beneath these volcanoes. Higher relative velocities beneath the Griggs and Snowy vents suggest that no magma is resident in the shallow crust beneath these volcanoes. ?? 2006 Elsevier B.V.

National Centers for Environmental Prediction

Science.gov Websites

OPERATIONAL 00Z, .... 12Z ... EXPERIMENTAL Daily Comparisons between GFS/GEFS control & ECMWF/ECMWF control 00Z T382/38km GFS, 00Z T190/70km GEFS control 12Z T1279/16km ECMWF, 12Z T639/30km ECMWF ensemble control Daily Values of 500 hPa Height AC, RMS, Talagrand & Outliers Mean of 14 GFS, 10 ECMWF and 16

Assessment and Analysis of QuikSCAT Vector Wind Products for the Gulf of Mexico: A Long-Term and Hurricane Analysis.

PubMed

Sharma, Neha; D'Sa, Eurico

2008-03-18

The northern Gulf of Mexico is a region that has been frequently impacted in recent years by natural disasters such as hurricanes. The use of remote sensing data such as winds from NASA's QuikSCAT satellite sensor would be useful for emergency preparedness during such events. In this study, the performance of QuikSCAT products, including JPL's latest Level 2B (L2B) 12.5 km swath winds, were evaluated with respect to buoy-measured winds in the Gulf of Mexico for the period January 2005 to February 2007. Regression analyses indicated better accuracy of QuikSCAT's L2B DIRTH, 12.5 km than the Level 3 (L3), 25 km wind product. QuikSCAT wind data were compared directly with buoy data keeping a maximum time interval of 20 min and spatial interval of 0.1° (≈10 km). R² values for moderate wind speeds were 0.88 and 0.93 for L2B, and 0.75 and 0.89 for L3 for speed and direction, respectively. QuikSCAT wind comparisons for buoys located offshore were better than those located near the coast. Hurricanes that took place during 2002-06 were studied individually to obtain regressions of QuikSCAT versus buoys for those events. Results show QuikSCAT's L2B DIRTH wind product compared well with buoys during hurricanes up to the limit of buoy measurements. Comparisons with the National Hurricane Center (NHC) best track analyses indicated QuikSCAT winds to be lower than those obtained by NHC, possibly due to rain contamination, while buoy measurements appeared to be constrained at high wind speeds. This study has confirmed good agreement of the new QuikSCAT L2B product with buoy measurements and further suggests its potential use during extreme weather conditions in the Gulf of Mexico.

L-asparaginase activity in Aeromonas sp. isolated from freshwater mussel.

PubMed

Pattnaik, S; Kabi, R; Janaki Ram, K; Bhanot, K K

2000-11-01

Aeromonas sp. from Lamellidens marginalis produced L-asparaginase when grown at 37 degrees C. The optimum enzyme activity was at pH 9 when temperature was 45 degrees C. Half-life of partially purified enzyme at 50 degrees C and 55 degrees C was 35 and 20 min, respectively. Activation and deactivation energies of partially purified enzyme were 17.48 and 24.86 kcal mol-1 respectively. The enzyme exhibited a Km (L-asparagine) value of 4.9 x 10(-6) mol l-1 and a Vmax of 9.803 IU ml-1. Three metal ions inhibited the enzyme activity at 10-20 mumol l-1 concentrations. Catalytic activity was also inhibited by EDTA, iodoacetic acid, parachloromercuribenzoic acid and phenylmethylsulphonyl fluoride at 0.1 mumol l-1.

Purification and characterization of cathepsin L in arrowtooth flounder (Atheresthes stomias) muscle.

PubMed

Visessanguan, Wonnop; Benjakul, Soottawat; An, Haejung

2003-03-01

A predominant, heat-activated proteinase in muscle extract of arrowtooth flounder (Atheresthes stomias) was purified to 55-fold by heat treatment, followed by a series of chromatographic separations. The apparent molecular mass of the purified enzyme was 27 kDa by size exclusion chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The proteinase had high affinity and activity toward Z-Phe-Arg-NMec with K(m) and k(cat) values of 8.2 microM and 12.2/s, respectively. Activity was inhibited by sulfhydryl reagents and activated by reducing agents. The purified proteinase displayed optimal activity at pH 5.0-5.5 and 60 degrees C, respectively. Consistent with the properties of proteases from other species, the heat-activated proteinase in arrowtooth flounder can be identified as cathepsin L.

Seismic properties of Leg 195 serpentinites and their geophysical implications

USGS Publications Warehouse

Courtier, Anna M.; Hart, David J.; Christensen, Nikolas I.; Shinohara, Masanao; Salisbury, Matthew H.; Richter, Carl

2006-01-01

Knowledge of seismic velocities is necessary to constrain the lithologies encountered in seismic studies. We measured the seismic velocities, both compressional and shear wave, of clasts recovered during Ocean Drilling Program Leg 195 from a serpentine mud volcano, the South Chamorro Seamount. The compressional wave velocities of these clasts vary from a lower value of 5.5 km/s to an upper value of 6.1 km/s at a confining stress of 200 MPa. The shear wave velocities vary from a lower value of 2.8 km/s to an upper value of 3.3 km/s at a confining stress of 200 MPa. The densities of the samples vary from 2548 to 2701 kg/m3. These velocities and densities are representative of the highly serpentinized harzburgite and dunite mineralogy of the clasts. Velocities from a seismic study of the Izu-Bonin forearc wedge were used to calculate the degree of serpentinization in the forearc wedge. The seismic velocities of the forearc wedge are higher than the velocities of the clasts recovered from the South Chamorro Seamount, suggesting that the clasts are more serpentinized than the forearc wedge.

Seasonal variations of NO and O3 at altitudes of 18.3 and 21.3 km

NASA Technical Reports Server (NTRS)

Loewenstein, M.; Savage, H. F.; Whitten, R. C.

1975-01-01

Nitric oxide and ozone concentrations have been measured in situ from a high-altitude research aircraft. Data which show the variations of NO and O3 with the time of year are presented for altitudes of 18.3 and 21.3 km. The extreme values of the observed NO concentrations at 21.3 km are 1.2 billion per cu cm in summer and 0.2 billion per cu cm in winter. At 18.3 km the extreme values are 1.6 billion per cu cm in summer and 0.1 billion per cu cm in winter. The smoothed NO seasonal data show a variation of about a factor of 2.5 at 21.3 km and a factor of 4 at 18.3 km. The ozone data show the generally expected magnitude and seasonal variation. We have used a photochemical model employing the measured ozone concentrations, the mean solar zenith angle, and seasonal HNO3 data reported by others to predict the seasonal NO variation at 20 km. The result is a summer-to-winter NO ratio of 2.5 which is in fair agreement with the observed ratios.

Validation of satellite-retrieved MBL cloud properties using DOE ARM AMF measurements at the Azores

NASA Astrophysics Data System (ADS)

Xi, B.; Dong, X.; Minnis, P.; Sun-Mack, S.

2013-05-01

Marine Boundary Layer (MBL) cloud properties derived for the Clouds and the Earth's Radiant Energy System (CERES) Project using Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) data are compared with observations taken at the Atmospheric Radiation Measurement (ARM) AMF AZORES site from June 2009 through December 2010. Retrievals from ARM surface-based data were averaged over a 1-hour interval centered at the time of each satellite overpass, and the CERES-MODIS Ed4 cloud properties were averaged within a 30-km x 30-km box centered on the ARM AZORES site. Two datasets were analyzed: all of the single-layered unbroken decks (SL) and those cases without temperature inversions. The CERES-MODIS cloud top/base heights were determined from cloud top/base temperature by using a lapse rate method normalized to the 24-h mean surface air temperature. The preliminary results show: for all SL MBL at daytime, they are, on average, 0.148 km (cloud top) and 0.087 km (cloud base) higher than the ARM radar-lidar observed cloud top and base, respectively. At nighttime, they are 0.446 km (cloud top) and 0.334 km (cloud base). For those cases without temperature inversions, the comparisons are close to their SL counterparts. For cloud temperatures, the MODIS-derived cloud-top and -base temperatures are 1.6 K lower and 0.4 K higher than the surface values with correlations of 0.92 during daytime. At nighttime, the differences are slightly larger and correlations are lower than daytime comparisons. Variations in the height difference are mainly caused by uncertainties in the surface air temperatures and lapse rates. Based on a total of 61 daytime and 87 nighttime samples (ALL SL cases), the temperature inversion layers occur about 72% during daytime and 83% during nighttime. The difference of surface-observed lapse rate and the satellite derived lapse rate can be 1.6 K/km for daytime and 3.3K/km for nighttime. From these lapse rates, we can further analyze the surface air temperature difference that used to calculate these lapse rate, which are ~3K difference between surface-observed and the satellite derived during the daytime and 5.1 K during nighttime. Further studies of the cause of the temperature inversions that may help the cloud heights retrievals by satellite. The preliminary comparisons in MBL microphysical properties have shown that the averaged CERES-MODIS derived MBL cloud-droplet effective radius is only 1.5 μm larger than ARM retrieval (13.2 μm), and LWP values are also very close to each other (112 vs. 124 gm-2) with a relative large difference in optical depth (10.6 vs. 14.4).

Modeling of the Foca-Uzunada magnetic anomaly and thermal structure in the gulf of Izmir, western Turkey

NASA Astrophysics Data System (ADS)

Aydemir, Attila; Bilim, Funda; Cifci, Gunay; Okay, Seda

2018-05-01

The Gulf of Izmir (GoI) is one of the largest gulfs in the Aegean Sea, Turkey. There is a large magnetic anomaly extending in the NE-SW direction between Foca and Uzunada (Uzun Island) in the gulf. Previously, Curie Point Depth (CPD), geothermal gradient, heat-flow and radiogenic heat production maps of the onshore part of the Aegean region were constructed from the aeromagnetic data. In this study, the same maps except radiogenic heat production map are presented for the offshore part and the largest magnetic anomaly in the northern part of the gulf is focused, particularly. As a result, the thermal structure of GoI is clearly defined and according to the results of this study, CPD values were found from 7 km in the NE of Foca to 10 km through the south of the gulf. The geothermal gradient values vary between 50 and 80 °C/km. Maximum heat flow values around the anomaly are calculated as 200 and 215 mW/m2 according to the thermal conductivity coefficients of 2.5 W m-1 K-1 and 2.7 W m-1 K-1, respectively. Although the anomaly is located in the Izmir Gulf; CPD, geothermic gradient, heat flow anomalies are shifted through the north of Foca and Aliaga towns in the Candarli Bay. This prominent anomaly in the Gulf of Izmir is associated with the magmatics that were encountered at 969 m in the Foca-1 well although it was drilled about 2 km away from the outermost closed contour of the magnetic anomaly. The anomaly is also modeled three dimensionally (3D) in this study. In the model map, the top of the causative body is completely located in the outer part of the gulf, and is very shallow at about 0.5 km while its bottom is inclined through the west of Cigli and Menemen. From this viewpoint, it is possible to suggest that the causative body is inclined through the Foca Peninsula. However, its closed contours are in the NE direction, through the Candarli Bay. Top depth of the causative body is also calculated from the basement horizon on the seismic sections crossing this anomaly. Depth calculations are consistent in these sections and confirm the top depths from the modeling study. The basement geometry in the seismic sections also reflects the shape of 3D model geometry, and bottom depth of the magmatics is also verified by the basement depth calculations in seismic sections.

Clumped isotope thermometry of calcite and dolomite in a contact metamorphic environment

NASA Astrophysics Data System (ADS)

Lloyd, Max K.; Eiler, John M.; Nabelek, Peter I.

2017-01-01

Clumped isotope compositions of slowly-cooled calcite and dolomite marbles record apparent equilibrium temperatures of roughly 150-200 °C and 300-350 °C, respectively. Because clumped isotope compositions are sensitive to the details of T-t path within these intervals, measurements of the Δ47 values of coexisting calcite and dolomite can place new constraints on thermal history of low-grade metamorphic rocks over a large portion of the upper crust (from ∼5 to ∼15 km depth). We studied the clumped isotope geochemistry of coexisting calcite and dolomite in marbles from the Notch Peak contact metamorphic aureole, Utah. Here, flat-lying limestones were intruded by a pluton, producing a regular, zoned metamorphic aureole. Calcite Δ47 temperatures are uniform, 156 ± 12 °C (2σ s.e.), across rocks varying from high-grade marbles that exceeded 500 °C to nominally unmetamorphosed limestones >5 km from the intrusion. This result appears to require that the temperature far from the pluton was close to this value; an ambient temperature just 20 °C lower would not have permitted substantial re-equilibration, and should have preserved depositional or early diagenetic Δ47 values several km from the pluton. Combining this result with depth constraints from overlying strata suggests the country rock here had an average regional geotherm of 22.3-27.4 °C/km from the late Jurassic Period until at least the middle Paleogene Period. Dolomite Δ47 in all samples above the talc + tremolite-in isograd record apparent equilibrium temperatures of 328-12+13 °C (1σ s.e.), consistent with the apparent equilibrium blocking temperature we expect for cooling from peak metamorphic conditions. At greater distances, dolomite Δ47 records temperatures of peak (anchi)metamorphism or pre-metamorphic diagenetic conditions. The interface between these domains is the location of the 330 °C isotherm associated with intrusion. Multiple-phase clumped isotope measurements are complemented by bulk δ13C and δ18O dolomite-calcite thermometry. These isotopic exchange thermometers are largely consistent with peak temperatures in all samples within 4 km of the contact, indicating that metamorphic recrystallization can occur even in samples too low-grade to produce growth of conventional metamorphic index minerals (i.e., talc and tremolite). Altogether, this work demonstrates the potential of these methods to quantify the conditions of metamorphism at sub-greenschist facies.

Photochemical control of the distribution of Venusian water

NASA Astrophysics Data System (ADS)

Parkinson, Christopher D.; Gao, Peter; Esposito, Larry; Yung, Yuk; Bougher, Stephen; Hirtzig, Mathieu

2015-08-01

We use the JPL/Caltech 1-D photochemical model to solve continuity diffusion equation for atmospheric constituent abundances and total number density as a function of radial distance from the planet Venus. Photochemistry of the Venus atmosphere from 58 to 112 km is modeled using an updated and expanded chemical scheme (Zhang et al., 2010, 2012), guided by the results of recent observations and we mainly follow these references in our choice of boundary conditions for 40 species. We model water between 10 and 35 ppm at our 58 km lower boundary using an SO2 mixing ratio of 25 ppm as our nominal reference value. We then vary the SO2 mixing ratio at the lower boundary between 5 and 75 ppm holding water mixing ratio of 18 ppm at the lower boundary and finding that it can control the water distribution at higher altitudes. SO2 and H2O can regulate each other via formation of H2SO4. In regions of high mixing ratios of SO2 there exists a "runaway effect" such that SO2 gets oxidized to SO3, which quickly soaks up H2O causing a major depletion of water between 70 and 100 km. Eddy diffusion sensitivity studies performed characterizing variability due to mixing that show less of an effect than varying the lower boundary mixing ratio value. However, calculations using our nominal eddy diffusion profile multiplied and divided by a factor of four can give an order of magnitude maximum difference in the SO2 mixing ratio and a factor of a few difference in the H2O mixing ratio when compared with the respective nominal mixing ratio for these two species. In addition to explaining some of the observed variability in SO2 and H2O on Venus, our work also sheds light on the observations of dark and bright contrasts at the Venus cloud tops observed in an ultraviolet spectrum. Our calculations produce results in agreement with the SOIR Venus Express results of 1 ppm at 70-90 km (Bertaux et al., 2007) by using an SO2 mixing ratio of 25 ppm SO2 and 18 ppm water as our nominal reference values. Timescales for a chemical bifurcation causing a collapse of water concentrations above the cloud tops (>64 km) are relatively short and on the order of a less than a few months, decreasing with altitude to less than a few days.

47 CFR 73.807 - Minimum distance separation between stations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... and the right-hand column lists (for informational purposes only) the minimum distance necessary for...) Within 320 km of the Mexican border, LP100 stations must meet the following separations with respect to any Mexican stations: Mexican station class Co-channel (km) First-adjacent channel (km) Second-third...

A distance scale from the infrared magnitude/H I velocity-width relation. III - The expansion rate outside the local supercluster

NASA Astrophysics Data System (ADS)

Aaronson, M.; Mould, J.; Huchra, J.; Sullivan, W. T., III; Schommer, R. A.; Bothun, G. D.

1980-07-01

Infrared magnitudes and 21 cm H I velocity widths are presented for galaxies in the Pegasus I cluster (V ≍ 4000 km s-1), the Cancer cluster (V ≍ 4500 km s-1), cluster Zwicky 1400.4 ± 0949 (Z74-23) (V ≍ 6000 km s-1), and the Perseus supercluster (V ≍ 5500 km s-1). The data are used to determine redshift-independent distances from which values of the Hubble ratio can be derived. With a zero point based solely on the Sandage-Tammann distances to M3 1 and M33, the following results are obtained (zero-point error excluded): Pegasus I.--r = 42 ± 4 Mpc, V/r = 91 ± 8 km s-1 Mpc-1; Cancer.--r = = 49 ± 6 Mpc, V/r = 89 ± 11 km s-1 Mpc-1; Z74-23.--r = 6l ± 4 Mpc, V/r = 96 ± 7 km s-1 Mpc-1; Perseus supercluster.--r = 53 ± 2 Mpc, V/r = 104 ± 6 km s-1 Mpc-1; The closely similar value of the Hubble ratio found in the four independent samples suggests that the zero-point calibration in the IR/H I technique does not depend on environment. The difference between the mean of these Hubble ratios, V/r = 95 ± 4 km s-1 Mpc -1, and that measured for Virgo in Paper II, V/r = 65 ±4 km s-1 Mpc-1, is significant at a formal level of 5 σ. The simplest explanation of the discrepancy is to postulate a Local Group component of motion in the direction of Virgo. The resulting velocity perturbation is ΔV = 480 ± 75 km s-1. This value agrees well with recent observations of a dipole term in the 3 K microwave background, the only other anisotropy test for which a detection significance of 5 σ or more is claimed. We are thus led to a preliminary estimate for the value of the Hubble constant of H0 = 95 ± 4 km s-1 Mpc-1. If a zero point based on de Vaucouleurs's distances to M31 and M33 is adopted instead, all distances decrease by , and the Hubble constant increases by a similar amount. A variety of possible systematic errors which might affect the present conclusions are investigated, but we can find none that are relevant. In particular, because the galaxy samples are chosen from a cluster population which is generally all at the same distance, Malmquist bias does not occur. In fact, two of the clusters (Pegasus I and Z74-23) are sampled in both magnitude and velocity width to a level as deep as Virgo itself. Other observational data related to the value of H0 are examined, as are a number of previously used anisotropy tests, including color-luminosity relations, brightest cluster member(s), central surface brightnesses, and supernovae. We find that some of these tests support the present results, while contrary evidence is currently weak. A model in which Virgo gravitationally retards the Hubble flow of galaxies within the Local Supercluster provides a natural interpretation of our findings. A range of 1.5-3 in local density contrast then leads to a value of the density parameter Ω ≍ 0.7-0.2. The deceleration parameter q0 is then 0.35-0.1 for a simple Friedmann-type expanding universe.

Ab initio calculation of infrared intensities for hydrogen peroxide

NASA Technical Reports Server (NTRS)

Rogers, J. D.; Hillman, J. J.

1982-01-01

Results of an ab initio SCF quantum mechanical study are used to derive estimates for the infrared intensities of the fundamental vibrations of hydrogen peroxide. Atomic polar tensors (APTs) were calculated on the basis of a 4-31G basis set, and used to derive absolute intensities for the vibrational transitions. Comparison of the APTs calculated for H2O2 with those previously obtained for H2O and CH3OH, and of the absolute intensities derived from the H2O2 APTs with those derived from APTs transferred from H2O and CH3OH, reveals the sets of values to differ by no more than a factor of two, supporting the validity of the theoretical calculation. Values of the infrared intensities obtained correspond to A1 = 14.5 km/mol, A2 = 0.91 km/mol, A3 = 0.058 km/mol, A4 = 123 km/mol, A5 = 46.2 km/mol, and A6 = 101 km/mol. Charge, charge flux and overlap contributions to the dipole moment derivatives are also computed.

Ab initio calculation of infrared intensities for hydrogen peroxide

NASA Astrophysics Data System (ADS)

Rogers, J. D.; Hillman, J. J.

1982-04-01

Results of an ab initio SCF quantum mechanical study are used to derive estimates for the infrared intensities of the fundamental vibrations of hydrogen peroxide. Atomic polar tensors (APTs) were calculated on the basis of a 4-31G basis set, and used to derive absolute intensities for the vibrational transitions. Comparison of the APTs calculated for H2O2 with those previously obtained for H2O and CH3OH, and of the absolute intensities derived from the H2O2 APTs with those derived from APTs transferred from H2O and CH3OH, reveals the sets of values to differ by no more than a factor of two, supporting the validity of the theoretical calculation. Values of the infrared intensities obtained correspond to A1 = 14.5 km/mol, A2 = 0.91 km/mol, A3 = 0.058 km/mol, A4 = 123 km/mol, A5 = 46.2 km/mol, and A6 = 101 km/mol. Charge, charge flux and overlap contributions to the dipole moment derivatives are also computed.

Biochemical and molecular characterization of the isocitrate dehydrogenase with dual coenzyme specificity from the obligate methylotroph Methylobacillus Flagellatus.

PubMed

Romkina, Anastasia Y; Kiriukhin, Michael Y

2017-01-01

The isocitrate dehydrogenase (MfIDH) with unique double coenzyme specificity from Methylobacillus flagellatus was purified and characterized, and its gene was cloned and overexpressed in E. coli as a fused protein. This enzyme is homodimeric,-with a subunit molecular mass of 45 kDa and a specific activity of 182 U mg -1 with NAD+ and 63 U mg -1 with NADP+. The MfIDH activity was dependent on divalent cations and Mn2+ enhanced the activity the most effectively. MfIDH exhibited a cofactor-dependent pH-activity profile. The optimum pH values were 8.5 (NAD+) and 6.0 (NADP+).The Km values for NAD+ and NADP+ were 113 μM and 184 μM respectively, while the Km values for DL-isocitrate were 9.0 μM (NAD+), 8.0 μM (NADP+). The MfIDH specificity (kcat/Km) was only 5-times higher for NAD+ than for NADP+. The purified MfIDH displayed maximal activity at 60°C. Heat-inactivation studies showed that the MfIDH was remarkably thermostable, retaining full activity at 50°C and losting ca. 50% of its activity after one hour of incubation at 75°C. The enzyme was insensitive to the presence of intermediate metabolites, with the exception of 2 mM ATP, which caused 50% inhibition of NADP+-linked activity. The indispensability of the N6 amino group of NAD(P)+ in its binding to MfIDH was demonstrated. MfIDH showed high sequence similarity with bacterial NAD(P)+-dependent type I isocitrate dehydrogenases (IDHs) rather than with eukaryotic NAD+-dependent IDHs. The unique double coenzyme specificity of MfIDH potentially resulted from the Lys340, Ile341 and Ala347 residues in the coenzyme-binding site of the enzyme. The discovery of a type I IDH with double coenzyme specificity elucidates the evolution of this subfamily IDHs and may provide fundamental information for engineering enzymes with desired properties.

Comparative study of regulated and unregulated air pollutant emissions before and after conversion of automobiles from gasoline power to liquefied petroleum gas/gasoline dual-fuel retrofits.

PubMed

Yang, Hsi-Hsien; Chien, Shu-Mei; Cheng, Man-Ting; Peng, Chiung-Yu

2007-12-15

Liquefied petroleum gas (LPG) is increasingly being examined as an alternative to gasoline use in automobiles as interest grows in reducing air pollutant emissions. In this study, emissions of regulated (CO, THC, NO(x)) and unregulated air pollutants, including CO2, particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and BTEX (acronym for benzene, toluene, ethylbenzene, xylene), were measured before and after conversion of nine gasoline-powered automobiles to LPG/ gasoline dual-fuel retrofits. The tests were conducted on a standard chassis dynamometer in accordance with the United States Environmental Protection Agency FTP-75 test procedure, with the exception that all tests were conducted under hot-start driving conditions. The influences of LPG on air pollutant emission levels and carcinogenic potency were investigated and compared with gasoline. The results showed average emission factors of 0.14 g/km, 0.33 mg/km, 0.09 g/km, 0.44 g/km, and 197 g/km for CO, THC, NO(x), PM, and CO2, respectively, for LPG/ gasoline dual-fuel retrofits. Paired-sample t-test results indicated that the emissions of CO (p = 0.03), THC (p = 0.04), and CO2 (p = 4.6 x 10(-8)) were significantly reduced with the retrofit in comparison with gasoline-powered automobiles. The reduction percentages were 71%, 89%, and 14% for CO, THC, and CO2, respectively. The average total PAH emission factor for LPG was 217 microg/km, which is significantly lower than gasoline (863 microg/km; p = 0.05). The PAH corresponding carcinogenicities (BaP(eq)) were calculated via toxic equivalencies based on benzo(a)pyrene (BaP). Paired-sample t-test results fortotal BaP(eq) emissions showed no significant difference between gasoline (30.0 microg/km) and LPG (24.8 microg/km) at a confidence level of 95%. The discrepancy between PAH and BaP(eq) emissions resulted from the higher emission percentages of high molecular weight PAHs for LPG, which might be from lubricant oil. The average emission factors of benzene, toluene, ethylbenzene, and xylene were 351, 4400, 324, and 1100 microg/ km, respectively, with LPG as fuel, which were all significantly lower than those for gasoline (95% confidence level). The average reduction percentages were 78%, 61%, 57%, and 58% for benzene, toluene, ethylbenzene, and xylene, respectively.

Nucleoside pyrophosphatase activity associated with pig kidney alkaline phosphatase

PubMed Central

Wass, Milica; Butterworth, P. J.

1971-01-01

1. A study was made of the hydrolysis, at pH9.0, of ATP and ADP catalysed by pig kidney alkaline phosphatase. Both of these nucleoside pyrophosphates are substrates for the enzyme; Km values are 4×10−5m for ATP and 6.3×10−5m for ADP. Vmax. for ADP is approximately double that of ATP. 2. Above 0.1mm approximately, both ATP and ADP are inhibitory, but the inhibition is reversible by the addition of Mg2+ ions to form MgATP2− or MgADP− complexes. The complexes, besides being non-inhibitory, are also substrates for the enzyme with Km values identical with those of the respective free nucleotides. 3. Mg2+ ions are inhibitory when present in excess of ATP or ADP. The degree of inhibition is greater with ATP as substrate, but with both ATP and ADP a mixed competitive–non-competitive type of inhibition is observed. 4. It is suggested that under normal conditions the enzyme is inhibited by cellular concentrations of ATP plus ADP but that an increase in the concentration of Mg2+ ions stimulates activity by relieving nucleoside pyrophosphate inhibition. The properties may be of importance in the regulation of the transport of bivalent cations. PMID:4331861

Paleothermal structure of the Nankai inner accretionary wedge estimated from vitrinite reflectance of cuttings

NASA Astrophysics Data System (ADS)

Fukuchi, Rina; Yamaguchi, Asuka; Yamamoto, Yuzuru; Ashi, Juichiro

2017-08-01

The paleothermal structure and tectonic evolution of an accretionary prism is basic information for understanding subduction zone seismogenesis. To evaluate the entire paleotemperature profile of the Integrated Ocean Drilling Program (IODP) Site C0002 located in the off-Kumano region of the Nankai Trough and penetrate the inner accretionary wedge down to 3058.5 m below the seafloor (mbsf), we performed a vitrinite reflectance analysis for cuttings and core samples during IODP expeditions 338 and 348: Nankai Trough seismogenic zone experiment. Although vitrinite reflectance values (Ro) tend to increase with depth, two reversals of these values suggested the existence of thrust fault zones with sufficient displacements to offset the paleothermal structure. The estimated maximum paleotemperatures are 42-70°C at 1200-1300 mbsf, 44-100°C at 1600-2400 mbsf, and 56-115°C at 2600-3000 mbsf, respectively. These temperatures roughly coincide with estimated modern temperatures; however, at a smaller scale, the reconstructed partial paleogeothermal gradient (˜60-150°C/km) recorded at the hanging- and footwall of the presumed thrust fault zone is higher than the modern geothermal gradient (˜30-40°C/km). This high paleogeothermal gradient was possibly obtained prior to subduction, reflecting the large heat flow of the young Philippine Sea Plate.

Statistical analysis of the mesospheric inversion layers over two symmetrical tropical sites: Réunion (20.8° S, 55.5° E) and Mauna Loa (19.5° N, 155.6° W)

NASA Astrophysics Data System (ADS)

Bègue, Nelson; Mbatha, Nkanyiso; Bencherif, Hassan; Tato Loua, René; Sivakumar, Venkataraman; Leblanc, Thierry

2017-11-01

In this investigation a statistical analysis of the characteristics of mesospheric inversion layers (MILs) over tropical regions is presented. This study involves the analysis of 16 years of lidar observations recorded at Réunion (20.8° S, 55.5° E) and 21 years of lidar observations recorded at Mauna Loa (19.5° N, 155.6° W) together with SABER observations at these two locations. MILs appear in 10 and 9.3 % of the observed temperature profiles recorded by Rayleigh lidar at Réunion and Mauna Loa, respectively. The parameters defining MILs show a semi-annual cycle over the two selected sites with maxima occurring near the equinoxes and minima occurring during the solstices. Over both sites, the maximum mean amplitude is observed in April and October, and this corresponds to a value greater than 35 K. According to lidar observations, the maximum and minimum mean of the base height ranged from 79 to 80.5 km and from 76 to 77.5 km, respectively. The MILs at Réunion appear on average ˜ 1 km thinner and ˜ 1 km lower, with an amplitude of ˜ 2 K higher than Mauna Loa. Generally, the statistical results for these two tropical locations as presented in this investigation are in fairly good agreement with previous studies. When compared to lidar measurements, on average SABER observations show MILs with greater amplitude, thickness and base altitudes of 4 K, 0.75 and 1.1 km, respectively. Taking into account the temperature error by SABER in the mesosphere, it can therefore be concluded that the measurements obtained from lidar and SABER observations are in significant agreement. The frequency spectrum analysis based on the lidar profiles and the 60-day averaged profile from SABER confirms the presence of the semi-annual oscillation where the magnitude maximum is found to coincide with the height range of the temperature inversion zone. This connection between increases in the semi-annual component close to the inversion zone is in agreement with most previously reported studies over tropics based on satellite observations. Results presented in this study confirm through the use of the ground-based Rayleigh lidar at Réunion and Mauna Loa that the semi-annual oscillation contributes to the formation of MILs over the tropical region.

GRAM-86 - FOUR DIMENSIONAL GLOBAL REFERENCE ATMOSPHERE MODEL

NASA Technical Reports Server (NTRS)

Johnson, D.

1994-01-01

The Four-D Global Reference Atmosphere program was developed from an empirical atmospheric model which generates values for pressure, density, temperature, and winds from surface level to orbital altitudes. This program can be used to generate altitude profiles of atmospheric parameters along any simulated trajectory through the atmosphere. The program was developed for design applications in the Space Shuttle program, such as the simulation of external tank re-entry trajectories. Other potential applications would be global circulation and diffusion studies, and generating profiles for comparison with other atmospheric measurement techniques, such as satellite measured temperature profiles and infrasonic measurement of wind profiles. The program is an amalgamation of two empirical atmospheric models for the low (25km) and the high (90km) atmosphere, with a newly developed latitude-longitude dependent model for the middle atmosphere. The high atmospheric region above 115km is simulated entirely by the Jacchia (1970) model. The Jacchia program sections are in separate subroutines so that other thermosphericexospheric models could easily be adapted if required for special applications. The atmospheric region between 30km and 90km is simulated by a latitude-longitude dependent empirical model modification of the latitude dependent empirical model of Groves (1971). Between 90km and 115km a smooth transition between the modified Groves values and the Jacchia values is accomplished by a fairing technique. Below 25km the atmospheric parameters are computed by the 4-D worldwide atmospheric model of Spiegler and Fowler (1972). This data set is not included. Between 25km and 30km an interpolation scheme is used between the 4-D results and the modified Groves values. The output parameters consist of components for: (1) latitude, longitude, and altitude dependent monthly and annual means, (2) quasi-biennial oscillations (QBO), and (3) random perturbations to partially simulate the variability due to synoptic, diurnal, planetary wave, and gravity wave variations. Quasi-biennial and random variation perturbations are computed from parameters determined by various empirical studies and are added to the monthly mean values. The UNIVAC version of GRAM is written in UNIVAC FORTRAN and has been implemented on a UNIVAC 1110 under control of EXEC 8 with a central memory requirement of approximately 30K of 36 bit words. The GRAM program was developed in 1976 and GRAM-86 was released in 1986. The monthly data files were last updated in 1986. The DEC VAX version of GRAM is written in FORTRAN 77 and has been implemented on a DEC VAX 11/780 under control of VMS 4.X with a central memory requirement of approximately 100K of 8 bit bytes. The GRAM program was originally developed in 1976 and later converted to the VAX in 1986 (GRAM-86). The monthly data files were last updated in 1986.

Purification and Characterization of a Novel NAD(P)+-Farnesol Dehydrogenase from Polygonum minus Leaves.

PubMed

Ahmad-Sohdi, Nor-Ain-Shahajar; Seman-Kamarulzaman, Ahmad-Faris; Mohamed-Hussein, Zeti-Azura; Hassan, Maizom

2015-01-01

Juvenile hormones have attracted attention as safe and selective targets for the design and development of environmentally friendly and biorational insecticides. In the juvenile hormone III biosynthetic pathway, the enzyme farnesol dehydrogenase catalyzes the oxidation of farnesol to farnesal. In this study, farnesol dehydrogenase was extracted from Polygonum minus leaves and purified 204-fold to apparent homogeneity by ion-exchange chromatography using DEAE-Toyopearl, SP-Toyopearl, and Super-Q Toyopearl, followed by three successive purifications by gel filtration chromatography on a TSK-gel GS3000SW. The enzyme is a heterodimer comprised of subunits with molecular masses of 65 kDa and 70 kDa. The optimum temperature and pH were 35°C and pH 9.5, respectively. Activity was inhibited by sulfhydryl reagents, metal-chelating agents and heavy metal ions. The enzyme utilized both NAD+ and NADP+ as coenzymes with Km values of 0.74 mM and 40 mM, respectively. Trans, trans-farnesol was the preferred substrate for the P. minus farnesol dehydrogenase. Geometrical isomers of trans, trans-farnesol, cis, trans-farnesol and cis, cis-farnesol were also oxidized by the enzyme with lower activity. The Km values for trans, trans-farnesol, cis, trans-farnesol and cis, cis-farnesol appeared to be 0.17 mM, 0.33 mM and 0.42 mM, respectively. The amino acid sequences of 4 tryptic peptides of the enzyme were analyzed by MALDI-TOF/TOF-MS spectrometry, and showed no significant similarity to those of previously reported farnesol dehydrogenases. These results suggest that the purified enzyme is a novel NAD(P)+-dependent farnesol dehydrogenase. The purification and characterization established in the current study will serve as a basis to provide new information for recombinant production of the enzyme. Therefore, recombinant farnesol dehydrogenase may provide a useful molecular tool in manipulating juvenile hormone biosynthesis to generate transgenic plants for pest control.

Nitrification exhibits Haldane kinetics in an agricultural soil treated with ammonium sulfate or dairy-waste compost.

PubMed

Koper, Teresa E; Stark, John M; Habteselassie, Mussie Y; Norton, Jeanette M

2010-11-01

An agricultural soil was treated with dairy-waste compost, ammonium-sulfate fertilizer or no added nitrogen (control) and planted to silage corn for 6 years. The kinetics of nitrification were determined in laboratory-shaken slurry assays with a range of substrate concentrations (0-20 mM NH(4)(+)) over a 24-h period for soils from the three treatments. Determined concentrations of substrate and product were fit to Michaelis-Menten and Haldane models. For all the treatments, the Haldane model was a better fit, suggesting that significant nitrification inhibition may occur in soils under high ammonium conditions similar to those found immediately after fertilization or waste applications. The maximum rate of nitrification (V(max)) was significantly higher for the fertilized and compost-treated soils (1.74 and 1.50 mmol N kg(-1) soil day(-1)) vs. control soil (0.98 mmol kg(-1) soil day(-1)). The K(m) and K(i) values were not significantly different, with average values of 0.02 and 27 mM NH(4)(+), respectively. Our results suggest that both N sources increased nitrifier community size, but did not shift the nitrifier community structure in ways that influenced enzyme affinity or sensitivity to ammonium. The K(m) values are comparable to those determined directly in other soils, but are substantially lower than those from most pure cultures of ammonia-oxidizing bacteria. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. No claim to original US government works.

Enzymatic activity of Glucose Oxidase from Aspergillus niger IPBCC.08.610 On Modified Carbon Paste Electrode as Glucose Biosensor

NASA Astrophysics Data System (ADS)

Rohmayanti, T.; Ambarsari, L.; Maddu, A.

2017-03-01

Glucose oxidase (GOx) has been developed as glucose sensor for measuring blood glucose level because of its specificity to glucose oxidation. This research aimed to determine kinetic parameters of GOx activity voltametrically and further test its potential as a glucose biosensor. GOx, in this research, was produced by local fungi Aspergillus niger IPBCC.08.610 which was isolated from local vine in Tarakan, East Borneo, Indonesia. GOx was immobilized with glutaraldehyde, which cross-linked onto modified carbon paste electrode (MCPE) nanofiber polyaniline. Intracellular GOx activity was higher than extracellular ones. Immobilized GOx used glutaraldehyde 2.5% and dripped on the surface of MCPE nanofiber polyaniline. MCPE have a high conductance in copper with the diameter of 3 mm. The concentration of glucose in the lowest concentration of 0.2 mM generated a current value of 0.413 mA while 2 mM of glucose induced a current of 3,869 mA value. Km and Imax of GOx in MCPE activities polyaniline nanofiber were 2.88 mM and 3.869 mA,respectively, with turnover (Kcat) of 13 s-1. Sensitivity was 1.09 mA/mM and response time to produce a maximum peak current was 25 seconds. Km value was then converted into units of mg/dL and obtained 56.4 mg/dL. GOximmo-IPB|MCPE electrode is potential to be able to detect blood glucose level in a normal condition and hypoglycemia conditions

ACE-FTS ozone, water vapour, nitrous oxide, nitric acid, and carbon monoxide profile comparisons with MIPAS and MLS

NASA Astrophysics Data System (ADS)

Sheese, Patrick E.; Walker, Kaley A.; Boone, Chris D.; Bernath, Peter F.; Froidevaux, Lucien; Funke, Bernd; Raspollini, Piera; von Clarmann, Thomas

2017-01-01

The atmospheric limb sounders, ACE-FTS on the SCISAT satellite, MIPAS on ESA's Envisat satellite, and MLS on NASA's Aura satellite, take measurements used to retrieve atmospheric profiles of O3, N2O, H2O, HNO3, and CO. Each was taking measurements between February 2004 and April 2012 (ACE-FTS and MLS are currently operational), providing hundreds of profile coincidences in the Northern and Southern hemispheres, and during local morning and evening. Focusing on determining diurnal and hemispheric biases in the ACE-FTS data, this study compares ACE-FTS version 3.5 profiles that are collocated with MIPAS and MLS, and analyzes the differences between instrument retrievals for Northern and Southern hemispheres and for local morning and evening data. For O3, ACE-FTS is typically within ±5% of mid-stratospheric MIPAS and MLS data and exhibits a positive bias of 10 to 20% in the upper stratosphere - lower mesosphere. For H2O, ACE-FTS exhibits an average bias of -5% between 20 and 60 km. For N2O, ACE-FTS agrees with MIPAS and MLS within -20 to +10% up to 45 km and 35 km, respectively. For HNO3, ACE-FTS typically agrees within ±10% below 30 km, and exhibits a positive bias of 10 to 20% above 30 km. With respect to MIPAS CO, ACE-FTS exhibits an average -11% bias between 28 and 50 km, and at higher altitudes a positive bias on the order of 10% (>100%) in the winter (summer). With respect to winter MLS CO, ACE-FTS is typically within ±10% between 25 and 40 km, and has an average bias of -11% above 40 km.

Why even active people get fatter--the asymmetric effects ofincreasing and decreasing exercise

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Paul T.

2006-01-06

Background: Public health policies for preventing obesityneed guidelines for active individuals who are at risk due to exerciserecidivism. Methods: Changes in adiposity were compared to the runningdistances at baseline and follow-up in men and women whose reportedexercise increased (N=4,632 and 1,953, respectively) or decreased (17,280and 5,970, respectively) during 7.7 years of follow-up. Results: PerDelta km/wk, decreases in running distance caused over four-fold greaterweight gain between 0-8 km/wk (slope+-SE, males: -0.068+ -0.005 kg/m2,females: -0.080+-0.01 kg/m2) than between 32-48 km/wk (-0.017+-0.002 and-0.010+-0.005 kg/m2, respectively). In contrast, increases in runningdistance produced the smallest weight losses between 0-8 km/wk andstatistically significant weight loss onlymore » above 16 km/wk in males and 32km/wk in females. Above 32 km/wk (30 kcal/kg) in men and 16 km/wk (15kcal/kg) in women, weight loss from increasing exercise was equal to orgreater than weight gained with decreasing exercise, otherwise weightgain exceeded weight loss. Substantial weight gain occurred in runnerswho quit running, which would be mostly retained with resumed activity.Conclusion: Public health recommendations should warn against the risksof irreversible weight gain with exercise cessation. Weight gained due toreductions in exercise below 30 kcal/kg in men and 15 kcal/kg in womenmay not be reversed by resuming prior activity. Current IOM guidelines(i.e., maintain total energy expenditure at 160 percent of basal) agreewith the men s exercise threshold for symmetric weight change withchanging exercise levels.« less

Crustal Thickness Beneath Libya and the Origin of Partial Melt Beneath AS Sawda Volcanic Province From Receiver Function Constraints

NASA Astrophysics Data System (ADS)

Lemnifi, Awad A.; Elshaafi, Abdelsalam; Browning, John; Aouad, Nassib S.; El Ebaidi, Saad K.; Liu, Kelly K.; Gudmundsson, Agust

2017-12-01

This study investigates crustal thickness and properties within the Libyan region. Results obtained from 15 seismic stations belonging to the Libyan Center for Remote Sensing and Space Science are reported, in addition to 3 seismic stations publically available, using receiver functions. The results show crustal thicknesses ranging from 24 km to 36 km (with uncertainties ranging between ±0.10 km and ±0.90 km). More specifically, crustal thickness ranges from 32 km to 36 km in the southern portion of the Libyan territory then becomes thinner, between 24 km and 30 km, in the coastal areas of Libya and thinnest, between 24 km and 28 km, in the Sirt Basin. The observed high Vp/Vs value of 1.91 at one station located at the AS Sawda Volcanic Province in central Libya indicates the presence of either partial melt or an abnormally warm area. This finding suggests that magma reservoirs beneath the Libyan territory may still be partially molten and active, thereby posing significant earthquake and volcanic risks. The hypothesis of an active magma source is further demonstrated though the presence of asthenospheric upwelling and extension of the Sirt Basin. This study provides a new calculation of unconsolidated sediment layers by using the arrival time of the P to S converted phases. The results show sediments thicknesses of 0.4 km to 3.7 km, with the Vp/Vs values ranging from 2.2 to 4.8. The variations in crustal thickness throughout the region are correlated with surface elevation and Bouguer gravity anomalies, which suggest that they are isostatically compensated.

Geospatial characterization of deforestation, fragmentation and forest fires in Telangana state, India: conservation perspective.

PubMed

Sudhakar Reddy, C; Vazeed Pasha, S; Jha, C S; Dadhwal, V K

2015-07-01

Conservation of biodiversity has been put to the highest priority throughout the world. The process of identifying threatened ecosystems will search for different drivers related to biodiversity loss. The present study aimed to generate spatial information on deforestation and ecological degradation indicators of fragmentation and forest fires using systematic conceptual approach in Telangana state, India. Identification of ecosystems facing increasing vulnerability can help to safeguard the extinctions of species and useful for conservation planning. The technological advancement of satellite remote sensing and Geographical Information System has increased greatly in assessment and monitoring of ecosystem-level changes. The areas of threat were identified by creating grid cells (5 × 5 km) in Geographical Information System (GIS). Deforestation was assessed using multi-source data of 1930, 1960, 1975, 1985, 1995, 2005 and 2013. The forest cover of 40,746 km(2), 29,299 km(2), 18,652 km(2), 18,368 km(2), 18,006 km(2), 17,556 km(2) and 17,520 km(2) was estimated during 1930, 1960, 1975, 1985, 1995, 2005 and 2013, respectively. Historical evaluation of deforestation revealed that major changes had occurred in forests of Telangana and identified 1095 extinct, 397 critically endangered, 523 endangered and 311 vulnerable ecosystem grid cells. The fragmentation analysis has identified 307 ecosystem grid cells under critically endangered status. Forest burnt area information was extracted using AWiFS data of 2005 to 2014. Spatial analysis indicates total fire-affected forest in Telangana as 58.9% in a decadal period. Conservation status has been recorded depending upon values of threat for each grid, which forms the basis for conservation priority hotspots. Of existing forest, 2.1% grids had severe ecosystem collapse and had been included under the category of conservation priority hotspot-I, followed by 27.2% in conservation priority hotspot-II and 51.5% in conservation priority hotspot-III. This analysis complements assessment of ecosystems undergoing multiple threats. An integrated approach involving the deforestation and degradation indicators is useful in formulating the strategies to take appropriate conservation measures.

Design of broadband dispersion flattened fiber for DWDM system: Performance analysis using various modulation formats

NASA Astrophysics Data System (ADS)

Goel, Aditya; Pandey, Gaurav

2018-05-01

In this paper, unique design of an optimal broadband optical dispersion flattened fiber (DFF) is proposed, which is capable of supporting the data rate of the order of Tb/s. The analysis of the single mode fiber for the design of the proposed DFF has been carried out by employing the quadratic Finite Element Method (FEM) with generalized refractive index (R. I.) profile. The minimization of the dispersion with respect to various profile parameters within the specified wavelength band is the essential optimization criteria. Computations show that a DFF can be designed where the overall dispersion can be restricted within ± 1 ps/km-nm over the entire spectral span ranging from 1290 to 1540 nm (250 nm) exhibiting a very small maximum value of dispersion slope (± 0.02 ps / (nm2-km)) in particular. The detailed performance analysis of the proposed DFF with different modulation techniques has been carried out in order to critically evaluate the performance of the DFF with respect to various significant parameters. The results suggest an excellent design of broadband optical waveguide capable of supporting high-speed data rate (40 Tb/s) through the single DFF, ideally suitable for the long haul dense wavelength division multiplexing (DWDM) optical transmission systems.

The uptake of NO3-, NO2-, and NH4+ by intact wheat (Triticum aestivum) seedlings. I. Induction and kinetics of transport systems

NASA Technical Reports Server (NTRS)

Goyal, S. S.; Huffaker, R. C.

1986-01-01

The inducibility and kinetics of the NO3-, NO2-, and NH4+ transporters in roots of wheat seedlings (Triticum aestivum cv Yercora Rojo) were characterized using precise methods approaching constant analysis of the substrate solutions. A microcomputer-controlled automated high performance liquid chromatography system was used to determine the depletion of each N species (initially at 1 millimolar) from complete nutrient solutions. Uptake rate analyses were performed using computerized curve-fitting techniques. More precise estimates were obtained for the time required for the extent of the induction of each transporter. Up to 10 and 6 hours, respectively, were required to achieve apparent full induction of the NO3- and NO2- transporters. Evidence for substrate inducibility of the NH4+ transporters requiring 5 hours is presented. The transport of NO3- was mediated by a dual system (or dual phasic), whereas only single systems were found for transport of NO2- and NH4+. The Km values for NO3-, NO2-, and NH4+ were, respectively, 0.027, 0.054, and 0.05 millimolar. The Km for mechanism II of NO3- transport could not be defined in this study as it exhibited only apparent first order kinetics up to 1 millimolar.

Statistical Analysis of Seismicity in the Sumatra Region

NASA Astrophysics Data System (ADS)

Bansal, A.; Main, I.

2007-12-01

We examine the effect of the great M=9.0 Boxing day 2004 earthquake on the statistics of seismicity in the Sumatra region by dividing data from the NEIC catalogue into two time windows before and after the earthquake. First we determine a completeness threshold of magnitude 4.5 for the whole dataset from the stability of the maximum likelihood b-value with respect to changes in the threshold. The split data sets have similar statistical sampling, with 2563 events before and 3701 after the event. Temporal clustering is first quantified broadly by the fractal dimension of the time series to be respectively 0.137, 0.259 and 0.222 before, after and for the whole dataset, compared to a Poisson null hypothesis of 0, indicating a significant increase in temporal clustering after the event associated with aftershocks. To quantify this further we apply the Epidemic Type Aftershock Sequence (ETAS) model. The background random seismicity rate £g and the coefficient Ñ, a measure of an efficiency of a magnitude of an earthquake in generating its aftershocks, do not change significantly when averaged over the two time periods. In contrast the amplitude A of aftershock generation changes by a factor 4 or so, and there is a small but statistically significant increase in the Omori decay exponent p, indicating a faster decay rate of the aftershocks after the Sumatra earthquake. The ETAS model parameters are calculated for different magnitude threshold (i.e. 4.5, 5.0, 5.5) with similar results for the different magnitude thresholds. The Ñ values increases from near 1 to near 1.5, possibly reflecting known changes in the scaling exponent between scalar moment and magnitude with increasing magnitude. A simple relation of magnitude and span of aftershock activity indicates that detectable aftershock activity of the Sumatra earthquake may last up to 8.7 years. Earthquakes are predominantly in the depth range 30-40 km before 20-30 km after the mainshock, compared to a CMT centroid depth of the earthquake of 28.6 km.

Screening and Characterization of Polygalacturonase as Potential Enzyme for Keprok Garut Orange (Citrus nobilis var. chrysocarpa) Juice Clarification

NASA Astrophysics Data System (ADS)

Widowati, E.; Utami, R.; Kalistyatika, K.

2017-11-01

Use of thermostable enzyme from bacilli for industrial application is significant. This research aimed to isolate thermophilic pectinolytic bacteria from orange peel and vegetable waste which produced thermostable polygalacturonase, to investigate the polygalacturonase ability in clarifying keprok Garut orange juice, and to characterize polygalacturonase based on pH optimum, temperature optimum, enzyme stability, enzyme kinetics KM, and Vmax. Obtained, 14 isolates that further selected to 4 best isolates based on highest polygalacturonase activity and keprok Garut orange juice clarification ability. Four selected enzyme isolates were AR 2, AR 4, KK 4, and KK 5 had ability to increase juice transmittance, decrease juice viscosity and also reduce total soluble solid. Furthermore 4 selected isolates were partially purified by ammonium sulphate precipitation and dialysis method. Four partially purified enzymes were known that enzyme character of AR 2 optimum at pH 6; AR 4 optimum at pH 5.5; KK 4 optimum at pH 6; and KK 5 optimum at pH 4.5. Four enzymes were optimum at temperature 60°C thus stable at temperature 50-60°C, this characteristic indicate that enzymes were thermostable. AR 2 showed active activity stable at pH 4-7; AR 4 showed active activity stable at pH 6-7; KK 4 showed active activity stable at pH 4-6; however KK 5 stable at pH 4-5. Enzyme AR 2 and KK 4 was getting inactive at pH 11, thus AR 4 and KK 5 inactive at pH 12. KM value of AR 2, AR 4, KK 4, and KK 5 was 0.0959; 0.0974; 0.0966; and 0.178 mg/ml respectively. Vmax of AR 2, AR 4, KK 4, and KK 5 was 0.0203; 0.0202; 0.0185; and 0.0229 U/ml respectively. Enzyme AR 2 was the most compatible enzyme to be applied in keprok Garut orange juice clarification for it had the lowest KM value.

Towards the Moho depth and Moho density contrast along with their uncertainties from seismic and satellite gravity observations

NASA Astrophysics Data System (ADS)

Abrehdary, M.; Sjöberg, L. E.; Bagherbandi, M.; Sampietro, D.

2017-12-01

We present a combined method for estimating a new global Moho model named KTH15C, containing Moho depth and Moho density contrast (or shortly Moho parameters), from a combination of global models of gravity (GOCO05S), topography (DTM2006) and seismic information (CRUST1.0 and MDN07) to a resolution of 1° × 1° based on a solution of Vening Meinesz-Moritz' inverse problem of isostasy. This paper also aims modelling of the observation standard errors propagated from the Vening Meinesz-Moritz and CRUST1.0 models in estimating the uncertainty of the final Moho model. The numerical results yield Moho depths ranging from 6.5 to 70.3 km, and the estimated Moho density contrasts ranging from 21 to 650 kg/m3, respectively. Moreover, test computations display that in most areas estimated uncertainties in the parameters are less than 3 km and 50 kg/m3, respectively, but they reach to more significant values under Gulf of Mexico, Chile, Eastern Mediterranean, Timor sea and parts of polar regions. Comparing the Moho depths estimated by KTH15C and those derived by KTH11C, GEMMA2012C, CRUST1.0, KTH14C, CRUST14 and GEMMA1.0 models shows that KTH15C agree fairly well with CRUST1.0 but rather poor with other models. The Moho density contrasts estimated by KTH15C and those of the KTH11C, KTH14C and VMM model agree to 112, 31 and 61 kg/m3 in RMS. The regional numerical studies show that the RMS differences between KTH15C and Moho depths from seismic information yields fits of 2 to 4 km in South and North America, Africa, Europe, Asia, Australia and Antarctica, respectively.

A multi-criteria approach to identify favorable areas for goat production systems in Veracruz, México.

PubMed

Ramírez-Rivera, Emmanuel de Jesús; Lopez-Collado, Jose; Díaz-Rivera, Pablo; Ortega-Jiménez, Eusebio; Torres-Hernández, Glafiro; Jacinto-Padilla, Jazmín; Herman-Lara, Erasmo

2017-04-01

This research identifies favorable areas for goat production systems in the state of Veracruz, Mexico. Through the use of the analytic hierarchy process, layers of biophysical and soil information were combined to generate a model of favorability. Model validation was performed by calculating the area under the curve, the true skill statistic, and a qualitative comparison with census records. The results showed the existence of regions with high (4494.3 km 2 ) and moderate (2985.8 km 2 ) favorability, and these areas correspond to 6.25 and 4.15%, respectively, of the state territory and are located in the regions of Sierra de Huayacocotla, Perote, and Orizaba. These regions are characterized as mountainous and having predominantly temperate-wet or cold climates, and having montane mesophilic forests, containing pine, fir, and desert scrub. The reliability of the distribution model was supported by the area under the curve value (0.96), the true skill statistic (0.86), and consistency with census records.

Vertical variation of ice particle size in convective cloud tops.

PubMed

van Diedenhoven, Bastiaan; Fridlind, Ann M; Cairns, Brian; Ackerman, Andrew S; Yorks, John E

2016-05-16

A novel technique is used to estimate derivatives of ice effective radius with respect to height near convective cloud tops ( dr e / dz ) from airborne shortwave reflectance measurements and lidar. Values of dr e / dz are about -6 μ m/km for cloud tops below the homogeneous freezing level, increasing to near 0 μ m/km above the estimated level of neutral buoyancy. Retrieved dr e / dz compares well with previously documented remote sensing and in situ estimates. Effective radii decrease with increasing cloud top height, while cloud top extinction increases. This is consistent with weaker size sorting in high, dense cloud tops above the level of neutral buoyancy where fewer large particles are present, and with stronger size sorting in lower cloud tops that are less dense. The results also confirm that cloud-top trends of effective radius can generally be used as surrogates for trends with height within convective cloud tops. These results provide valuable observational targets for model evaluation.

Shuttle high resolution accelerometer package experiment results - Atmospheric density measurements between 60-160 km

NASA Technical Reports Server (NTRS)

Blanchard, R. C.; Hinson, E. W.; Nicholson, J. Y.

1988-01-01

Indirect or inferred values of atmospheric density encountered by the Shuttle Orbiter during reentry have been calculated from acceleration measurements made by the High Resolution Accelerometer Package (HiRAP) and the Orbiter Inertial Measurement Unit (IMU) liner accelerometers. The atmospheric density data developed from this study represent a significant gain with respect to the body of data collected to date by various techniques in the altitude range of 60 to 160 km. The data are unique in that they cover a very wide horizontal range during each flight and provide insight into the actual density variations encountered along the reentry flight path. The data, which were collected over about 3 years, are also characterized by variations in solar activity, geomagnetic index, and local solar time. Comparison of the flight-derived densities with various atmospheric models have been made, and analyses have attempted to characterize the data and to show correlation with selected physical variables.

Properties of lactate dehydrogenase from the isopod, Saduria entomon.

PubMed

Mulkiewicz, E; Zietara, M S; Stachowiak, K; Skorkowski, E F

2000-07-01

Saduria entomon lactate dehydrogenase (LDH-A4*) from thorax muscle was purified about 89 fold to specific activity 510 micromol NADH/min/mg using Cibacron Blue 3GA Agarose and Oxamate-Agarose chromatographies. The enzyme is a tetramer, with molecular weight of 140 kDa for the native enzyme and 36 kDa for the subunit. The isoelectric point was at pH 5.7. The enzyme possesses high heat stability (T50 = 71.5 degrees C). The optimum pH for pyruvate reduction reaction was 6.5, while for lactate oxidation one, the maximum activity was at pH 9.1. The Km for pyruvate was minimal at 5 degrees C, the average environmental temperature of the isopod. The Km values determined at 30 degrees C and optimal pH for pyruvate reduction and lactate oxidation were 0.18 and 90.04 mM, respectively. Amino acid compositional analyses showed the strongest resemblance of the isopod isoenzyme to cod (Gadus morhua) LDH-C4.

Ground-based microwave radiometry to determine stratospheric and mesospheric ozone profiles

NASA Astrophysics Data System (ADS)

Lobsiger, E.

1987-05-01

From April 1984 to April 1985 a microwave radiometer was operated at Bern measuring the thermal emission of the rotational ozone transition at 142.2 GHz to determine stratospheric and mesospheric ozone abundances in the range 25-75 km altitude. From a total of 334 retrieved daytime profiles, monthly mean ozone partial pressures for Umkehr layers 6-10 were calculated. On this basis ozone variations compare favorably with Umkehr data from the nearby Arosa station and with a monthly zonal mean model compiled from satellite data by Keating and Young (1985). From the microwave data, an annual mean ozone distribution was determined. The method retrieves somewhat larger ozone volume mixing ratios between 25 and 30 km altitude. For the rest of the measurement range of the sensor there is good agreement with 20-year annual mean ozone values from Arosa, with the Krueger and Minzner profile and with the respective annual mean data given by Keating and Young.

Plasma bullet current measurements in a free-stream helium capillary jet

NASA Astrophysics Data System (ADS)

Oh, Jun-Seok; Walsh, James L.; Bradley, James W.

2012-06-01

A commercial current monitor has been used to measure the current associated with plasma bullets created in both the positive and negative half cycles of the sinusoidal driving voltage sustaining a plasma jet. The maximum values of the positive bullet current are typically ˜750 µA and persist for 10 µs, while the peaks in the negative current of several hundred μA are broad, persisting for about 40 µs. From the time delay of the current peaks with increasing distance from the jet nozzle, an average bullet propagation speed has been measured; the positive and negative bullets travel at 17.5 km s-1 and 3.9 km s-1 respectively. The net space charge associated with the bullet(s) has also been calculated; the positive and negative bullets contain a similar net charge of the order of 10-9 C measured at all monitor positions, with estimated charged particle densities nb of ˜1010-1011 cm-3 in the bullet.

Vertical Variation of Ice Particle Size in Convective Cloud Tops

NASA Technical Reports Server (NTRS)

Van Diedenhoven, Bastiaan; Fridlind, Ann M.; Cairns, Brian; Ackerman, Andrew S.; Yorks, John E.

2016-01-01

A novel technique is used to estimate derivatives of ice effective radius with respect to height near convective cloud tops (dr(sub e)/dz) from airborne shortwave reflectance measurements and lidar. Values of dr(sub e)/dz are about -6 micrometer/km for cloud tops below the homogeneous freezing level, increasing to near 0 micrometer/km above the estimated level of neutral buoyancy. Retrieved dr(sub e)/dz compares well with previously documented remote sensing and in situ estimates. Effective radii decrease with increasing cloud top height, while cloud top extinction increases. This is consistent with weaker size sorting in high, dense cloud tops above the level of neutral buoyancy where fewer large particles are present and with stronger size sorting in lower cloud tops that are less dense. The results also confirm that cloud top trends of effective radius can generally be used as surrogates for trends with height within convective cloud tops. These results provide valuable observational targets for model evaluation.

Erratum: ``The Luminosity Function of IRAS Point Source Catalog Redshift Survey Galaxies'' (ApJ, 587, L89 [2003])

NASA Astrophysics Data System (ADS)

Takeuchi, Tsutomu T.; Yoshikawa, Kohji; Ishii, Takako T.

2004-05-01

We have mentioned that we normalized the parameters for the luminosity function by the Hubble constant H0=100 km s-1 Mpc-1 however, for the characteristic luminosity L* we erroneously normalized it by H0=70 km s-1 Mpc-1. As a result, we have proposed wrong numerical factors for L*. In addition, there is a typographic error in the exponent of equation (6) of the published manuscript. Correct values are as follows: L*=(4.34+/-0.86)×108 h-2 [Lsolar] for equation (4), and L*=(2.50+/-0.44)×109 h-2 [Lsolar] and L*=(9.55+/-0.20)×108 h-2 [Lsolar] for equations (5) and (6), respectively. All the other parameters are correct. The errors have occurred only in the final conversion, and they do not affect our discussions and conclusions at all. We thank P. Ranalli for pointing out the errors.

Radiation and chemistry in the stratosphere - Sensitivity to O2 absorption cross sections in the Herzberg continuum

NASA Technical Reports Server (NTRS)

Froidevaux, L.; Yung, Y. L.

1982-01-01

It is suggested that the discrepancies between observed and modeled vertical profiles of such halocarbons as CFCl3, as well as the problem of simultaneously fitting N2O, CH4, CF2Cl2 and CFCl3 profiles with a single eddy diffusion model, are due to an overestimation of the molecular oxygen absorption cross sections in the 200-220 nm spectral region. The replacement of current O2 cross sections in this range with values that are in better agreement with results for the compounds cited leads to N2O, CF2Cl2 and CFCl3 concentration reductions of factors 0.70, 0.62 and 0.19, respectively. Profiles of CH4, H2 and CO remain unchanged, and the predicted concentration of HNO3 above 30 km is reduced by about 50% for yet another improved fit with observations. It is noted that the correction proposed produces a 30% ozone increase near the 20-25 km peak.

ISEE-1 and 2 observations of field-aligned currents in the distant midnight magnetosphere

NASA Technical Reports Server (NTRS)

Elphic, R. C.; Kelly, T. J.; Russell, C. T.

1985-01-01

Magnetic field measurements obtained in the nightside magnetosphere by the co-orbiting ISEE-1 and 2 spacecraft have been examined for signatures of field-aligned currents (FAC). Such currents are found on the boundary of the plasma sheet both when the plasma sheet is expanding and when it is thinning. Evidence is often found for the existence of waves on the plasma sheet boundary, leading to multiple crossings of the FAC sheet. At times the boundary layer FAC sheet orientation is nearly parallel to the X-Z GSM plane, suggesting 'protrusions' of plasma sheet into the lobes. The boundary layer current polarity is, as expected, into the ionosphere in the midnight to dawn local time sector, and outward near dusk. Current sheet thicknesses and velocities are essentially independent of plasma sheet expansion or thinning, having typical values of 1500 km and 20-40 km/s respectively. Characteristic boundary layer current densities are about 10 nanoamps per square meter.

A High-Resolution Aerosol Retrieval Method for Urban Areas Using MISR Data

NASA Astrophysics Data System (ADS)

Moon, T.; Wang, Y.; Liu, Y.; Yu, B.

2012-12-01

Satellite-retrieved Aerosol Optical Depth (AOD) can provide a cost-effective way to monitor particulate air pollution without using expensive ground measurement sensors. One of the current state-of-the-art AOD retrieval method is NASA's Multi-angle Imaging SpectroRadiometer (MISR) operational algorithm, which has the spatial resolution of 17.6 km x 17.6 km. While the MISR baseline scheme already leads to exciting research opportunities to study particle compositions at regional scale, its spatial resolution is too coarse for analyzing urban areas where the AOD level has stronger spatial variations. We develop a novel high-resolution AOD retrieval algorithm that still uses MISR's radiance observations but has the resolution of 4.4km x 4.4km. We achieve the high resolution AOD retrieval by implementing a hierarchical Bayesian model and Monte-Carlo Markov Chain (MCMC) inference method. Our algorithm not only improves the spatial resolution, but also extends the coverage of AOD retrieval and provides with additional composition information of aerosol components that contribute to the AOD. We validate our method using the recent NASA's DISCOVER-AQ mission data, which contains the ground measured AOD values for Washington DC and Baltimore area. The validation result shows that, compared to the operational MISR retrievals, our scheme has 41.1% more AOD retrieval coverage for the DISCOVER-AQ data points and 24.2% improvement in mean-squared error (MSE) with respect to the AERONET ground measurements.

Stratospheric ozone variations in the equatorial region as seen in Stratiospheric Aerosol and Gas Experiment data

NASA Technical Reports Server (NTRS)

Shiotani, Masato; Hasebe, Fumio

1994-01-01

An analysis is made of equatorial ozone variations for 5 years, 1984-1989, using the ozone profile data derived from the Stratospheric Aerosol and Gas Experiment II (SAGE II) instrument. Attention is focused on the annual cycle and also on interannual variability, particularly the quasi-biennial oscillation (QBO) and El Nino-Southern Oscillation (ENSO) variations in the lower stratosphere, where the largest contribution to total column ozone takes place. The annual variation in zonal mean total ozone around the equator is composed of symmetric and asymmetric modes with respect to the equator, with maximum contributions being around 19 km for the symmetric mode and around 25 km for the asymmetric mode. The persistent zonal wavenumber 1 structure observed by the total ozone mapping spectrometer over the equator is almost missing in the SAGE-derived column amounts integrated in the stratosphere, suggesting a significant contribution from tropospheric ozone. Interannual variations in the equatorial ozone are dominated by the QBO above 20 km and the ENSO-related variation below 20 km. The ozone QBO is characterized by zonally uniform phase changes in association with the zonal wind QBO in the equatorial lower stratosphere. The ENSO-related ozone variation consists of both the east-west vacillation and the zonally uniform phase variation. During the El Nino event, the east-west contrast with positive (negative) deviations in the eastern (western) hemisphere is conspicuous, while the decreasing tendency of the zonal mean values is maximum at the same time.

Seismic velocity and attenuation structures in the Earth's inner core

NASA Astrophysics Data System (ADS)

Yu, Wen-Che

2007-12-01

I study seismic velocity and attenuation structures in the top 400 km of the Earth's inner core along equatorial paths, velocity-attenuation relationship, and seismic anisotropy in the top of the inner core beneath Africa. Seismic observations exhibit "east-west" hemispheric differences in seismic velocity, attenuation, and anisotropy. Joint modeling of the PKiKP-PKIKP and PKPbc-PKIKP phases is used to constrain seismic velocity and attenuation structures in the top 400 km of the inner core for the eastern and western hemispheres. The velocity and attenuation models for the western hemisphere are simple, having a constant velocity gradient and a Q value of 600 in the top 400 km of the inner core. The velocity and attenuation models for the eastern hemisphere appear complex. The velocity model for the eastern hemisphere has a small velocity gradient in the top 235 km, a steeper velocity gradient at the depth range of 235 - 375 km, and a gradient similar to PREM in the deeper portion of the inner core. The attenuation model for the eastern hemisphere has a Q value of 300 in the top 300 km and a Q value of 600 in the deeper portion of the inner core. The study of velocity-attenuation relationship reveals that inner core is anisotropic in both velocity and attenuation, and the direction of high attenuation corresponding to that of high velocity. I hypothesize that the hexagonal close packed (hcp) iron crystal is anisotropic in attenuation, with the axis of high attenuation corresponding to that of high velocity. Anisotropy in the top of the inner core beneath Africa is complex. Beneath eastern Africa, the thickness of the isotropic upper inner core is about 0 km. Beneath central and western Africa, the thickness of the isotropic upper inner core increases from 20 to 50 km. The velocity increase across the isotropic upper inner core and anisotropic lower inner core boundary is sharp, laterally varying from 1.6% - 2.2%. The attenuation model has a Q value of 600 for the isotropic upper inner core and 150 to 400 for the anisotropic lower inner core.

Evaluation of ML-MC as a Depth Discriminant in Yellowstone, USA and Italy

NASA Astrophysics Data System (ADS)

Li, Z.; Koper, K. D.; Burlacu, R.; Sun, D.; D'Amico, S.

2017-12-01

Recent work has shown that the difference between two magnitude scales, ML (local Richter magnitude) and MC (coda/duration magnitude), acts as a depth discriminant in Utah. Shallow seismic sources, such as mining induced earthquakes and explosions, have strongly negative ML-MC values, while deeper tectonic earthquakes have ML-MC values near zero. These observations imply that ML-MC might be effective at discriminating small explosions from deeper natural earthquakes at local distances. In this work, we examine seismicity catalogs for the Yellowstone region and Italy to determine if ML-MCacts as a depth discriminant in these regions as well. We identified 4,780 earthquakes that occurred in the Yellowstone region between Sept. 24, 1994 and March 31, 2017 for which both ML and MC were calculated. The ML-MC distribution is well described by a Gaussian function with a mean of 0.102 and a standard deviation of 0.326. We selected a subset of these events with accurate depths and determined mean ML-MC values in various depth bins. An event depth was considered accurate if the formal depth error was less than 2 km and either (1) the nearest station was within one focal depth or (2) the distance to the nearest station was smaller than the bin size. We find that ML-MC decreases as event depths become shallower than about 10 km. Similar to the results for Utah, the decrease is statistically significant and is robust with respect to small changes in bin size and the criteria used to define accurate depths. We used a similar process to evaluate whether ML-MC was a function of source depth for 63,555 earthquakes that occurred between April 16, 2005 and April 30, 2012 in Italy. The ML-MC values in Italy are also well described by a normal distribution, with a mean of -0.477 and standard deviation of 0.315. We again find a statistically significant decrease in ML-MC for shallow earthquakes. In contrast to the Yellowstone results, for Italy ML-MC decreases at a nearly constant rate as focal depths change from 30 km to 4 km, and then it flattens out for the shallowest events. Our results reinforce the idea that ML-MC acts as a depth discriminant, but because it appears to behave slightly differently in the two regions, more areas need to be evaluated in the future.

True Volumes of Slope Failure Estimated From a Quaternary Mass-Transport Deposit in the Northern South China Sea

NASA Astrophysics Data System (ADS)

Sun, Qiliang; Alves, Tiago M.; Lu, Xiangyang; Chen, Chuanxu; Xie, Xinong

2018-03-01

Submarine slope failure can mobilize large amounts of seafloor sediment, as shown in varied offshore locations around the world. Submarine landslide volumes are usually estimated by mapping their tops and bases on seismic data. However, two essential components of the total volume of failed sediments are overlooked in most estimates: (a) the volume of subseismic turbidites generated during slope failure and (b) the volume of shear compaction occurring during the emplacement of failed sediment. In this study, the true volume of a large submarine landslide in the northern South China Sea is estimated using seismic, multibeam bathymetry and Ocean Drilling Program/Integrated Ocean Drilling Program well data. The submarine landslide was evacuated on the continental slope and deposited in an ocean basin connected to the slope through a narrow moat. This particular character of the sea floor provides an opportunity to estimate the amount of strata remobilized by slope instability. The imaged volume of the studied landslide is 1035 ± 64 km3, 406 ± 28 km3 on the slope and 629 ± 36 km3 in the ocean basin. The volume of subseismic turbidites is 86 km3 (median value), and the volume of shear compaction is 100 km3, which are 8.6% and 9.7% of the landslide volume imaged on seismic data, respectively. This study highlights that the original volume of the failed sediments is significantly larger than that estimated using seismic and bathymetric data. Volume loss related to the generation of landslide-related turbidites and shear compaction must be considered when estimating the total volume of failed strata in the submarine realm.

Changes in the D region associated with three recent solar eclipses in the South Pacific region

NASA Astrophysics Data System (ADS)

Kumar, Sushil; Kumar, Abhikesh; Maurya, Ajeet K.; Singh, Rajesh

2016-06-01

We estimate D region changes due to 22 July 2009 total solar eclipse (SE), 13-14 November 2012 total SE, and 9-10 May 2013 annular SE, using VLF navigational transmitters signal observations at Suva, Fiji. The North West Cape (NWC) signal (19.8 kHz) showed an amplitude and phase decrease of 0.70 dB and 23° during November SE and 2.0 dB and 90° during May SE. The modeling using Long Wave Propagation Capability code for NWC-Suva path during November and May SEs showed an increase in average D region reflection height (H') and sharpness factor (β) by 0.6 and 0.5 km and 0.012 and 0.015 km-1, respectively. The July total SE for JJI-Suva path showed an increase in H' of 1.5 km and a decrease in β of 0.055 km-1. The decrease in the electron density calculated using SE time H' and β is maximum for July total SE and minimum for May annular SE. The effective recombination coefficient estimated from the decay and recovery of signal phase associated with May annular SE was higher (27%) than normal daytime value 5.0 × 10-7 cm-3 s-1 and varied between 1.47 × 10-6 and 1.15 × 10-7 cm-3 s-1 in the altitude 70 to 80 km. Morlet wavelet analysis of signals amplitude shows strong wave-like signatures (WLS) associated with three SEs with period ranging 24-66 min, but the intensity and duration of WLS show no clear dependence on SE magnitude and type. Apart from the cooling spot, the eclipse shadow can also generate WLS associated with atmospheric gravity waves.

Real-world fuel efficiency and exhaust emissions of light-duty diesel vehicles and their correlation with road conditions.

PubMed

Hu, Jingnan; Wu, Ye; Wang, Zhishi; Li, Zhenhua; Zhou, Yu; Wang, Haitao; Bao, Xiaofeng; Hao, Jiming

2012-01-01

The real-world fuel efficiency and exhaust emission profiles of CO, HC and NOx for light-duty diesel vehicles were investigated. Using a portable emissions measurement system, 16 diesel taxies were tested on different roads in Macao and the data were normalized with the vehicle specific power bin method. The 11 Toyota Corolla diesel taxies have very good fuel economy of (5.9 +/- 0.6) L/100 km, while other five diesel taxies showed relatively high values at (8.5 +/- 1.7) L/100 km due to the variation in transmission systems and emission control strategies. Compared to similar Corolla gasoline models, the diesel cars confirmed an advantage of ca. 20% higher fuel efficiency. HC and CO emissions of all the 16 taxies are quite low, with the average at (0.05 +/- 0.02) g/km and (0.38 +/- 0.15) g/km, respectively. The average NOx emission factor of the 11 Corolla taxies is (0.56 +/- 0.17) g/km, about three times higher than their gasoline counterparts. Two of the three Hyundai Sonata taxies, configured with exhaust gas recirculation (EGR) + diesel oxidation catalyst (DOC) emission control strategies, indicated significantly higher NO2 emissions and NO2/NOx ratios than other diesel taxies and consequently trigger a concern of possibly adverse impacts on ozone pollution in urban areas with this technology combination. A clear and similar pattern for fuel consumption and for each of the three gaseous pollutant emissions with various road conditions was identified. To save energy and mitigate CO2 emissions as well as other gaseous pollutant emissions in urban area, traffic planning also needs improvement.

Total solar eclipse effects on VLF signals: Observations and modeling

NASA Astrophysics Data System (ADS)

Clilverd, Mark A.; Rodger, Craig J.; Thomson, Neil R.; Lichtenberger, János; Steinbach, Péter; Cannon, Paul; Angling, Matthew J.

During the total solar eclipse observed in Europe on August 11, 1999, measurements were made of the amplitude and phase of four VLF transmitters in the frequency range 16-24 kHz. Five receiver sites were set up, and significant variations in phase and amplitude are reported for 17 paths, more than any previously during an eclipse. Distances from transmitter to receiver ranged from 90 to 14,510 km, although the majority were <2000 km. Typically, positive amplitude changes were observed throughout the whole eclipse period on path lengths <2000 km, while negative amplitude changes were observed on paths >10,000 km. Negative phase changes were observed on most paths, independent of path length. Although there was significant variation from path to path, the typical changes observed were ~3 dB and ~50°. The changes observed were modeled using the Long Wave Propagation Capability waveguide code. Maximum eclipse effects occurred when the Wait inverse scale height parameter β was 0.5 km-1 and the effective ionospheric height parameter H' was 79 km, compared with β=0.43km-1 and H'=71km for normal daytime conditions. The resulting changes in modeled amplitude and phase show good agreement with the majority of the observations. The modeling undertaken provides an interpretation of why previous estimates of height change during eclipses have shown such a range of values. A D region gas-chemistry model was compared with electron concentration estimates inferred from the observations made during the solar eclipse. Quiet-day H' and β parameters were used to define the initial ionospheric profile. The gas-chemistry model was then driven only by eclipse-related solar radiation levels. The calculated electron concentration values at 77 km altitude throughout the period of the solar eclipse show good agreement with the values determined from observations at all times, which suggests that a linear variation in electron production rate with solar ionizing radiation is reasonable. At times of minimum electron concentration the chemical model predicts that the D region profile would be parameterized by the same β and H' as the LWPC model values, and rocket profiles, during totality and can be considered a validation of the chemical processes defined within the model.

Trimethylamine-N-oxide counteracts urea effects on rabbit muscle lactate dehydrogenase function: a test of the counteraction hypothesis.

PubMed Central

Baskakov, I; Wang, A; Bolen, D W

1998-01-01

Trimethylamine-N-oxide (TMAO) in the cells of sharks and rays is believed to counteract the deleterious effects of the high intracellular concentrations of urea in these animals. It has been hypothesized that TMAO has the generic ability to counteract the effects of urea on protein structure and function, regardless of whether that protein actually evolved in the presence of these two solutes. Rabbit muscle lactate dehydrogenase (LDH) did not evolve in the presence of either solute, and it is used here to test the validity of the counteraction hypothesis. With pyruvate as substrate, results show that its Km and the combined Km of pyruvate and NADH are increased by urea, decreased by TMAO, and in 1:1 and 2:1 mixtures of urea:TMAO the Km values are essentially equivalent to the Km values obtained in the absence of the two solutes. In contrast, values of k(cat) and the Km for NADH as a substrate are unperturbed by urea, TMAO, or urea:TMAO mixtures. All of these effects are consistent with TMAO counteraction of the effects of urea on LDH kinetic parameters, supporting the premise that counteraction is a property of the solvent system and is independent of the evolutionary history of the protein. PMID:9591690

Joint transfer of time and frequency signals and multi-point synchronization via fiber network

NASA Astrophysics Data System (ADS)

Nan, Cheng; Wei, Chen; Qin, Liu; Dan, Xu; Fei, Yang; You-Zhen, Gui; Hai-Wen, Cai

2016-01-01

A system of jointly transferring time signals with a rate of 1 pulse per second (PPS) and frequency signals of 10 MHz via a dense wavelength division multiplex-based (DWDM) fiber is demonstrated in this paper. The noises of the fiber links are suppressed and compensated for by a controlled fiber delay line. A method of calibrating and characterizing time is described. The 1PPS is synchronized by feed-forward calibrating the fiber delays precisely. The system is experimentally examined via a 110 km spooled fiber in laboratory. The frequency stabilities of the user end with compensation are 1.8×10-14 at 1 s and 2.0×10-17 at 104 s average time. The calculated uncertainty of time synchronization is 13.1 ps, whereas the direct measurement of the uncertainty is 12 ps. Next, the frequency and 1PPS are transferred via a metropolitan area optical fiber network from one central site to two remote sites with distances of 14 km and 110 km. The frequency stabilities of 14 km link reach 3.0×10-14 averaged in 1 s and 1.4×10-17 in 104 s respectively; and the stabilities of 110 km link are 8.3×10-14 and 1.7×10-17, respectively. The accuracies of synchronization are estimated to be 12.3 ps for the 14 km link and 13.1 ps for the 110 km link, respectively. Project supported by the National Natural Science Foundation of China (Grant No. 61405227).

Evaluating the Sensitivity of Glacial Isostatic Adjustment to a Hydrous Melt at 410 km Depth

NASA Astrophysics Data System (ADS)

Hill, A. M.; Milne, G. A.; Ranalli, G.

2017-12-01

We present a sensitivity analysis aimed at testing whether observables related to GIA can support or refute the existence of a low viscosity partial melt layer located above the mantle transition zone, as required by the so-called "Transition Zone Water Filter" model (Bercovici and Karato 2003). In total, 400 model runs were performed sampling a range of melt layer thicknesses (1, 10 & 20 km) and viscosities (1015 - 1019 Pas) as well as plausible viscosity values in the upper and lower mantle. Comparing model output of postglacial decay times and j2, 18 of the considered viscosity models were found to be compatible with all of the observational constraints. Amongst these, only three `background' upper and lower mantle viscosities are permitted regardless of the properties of the melt layer: an upper mantle value of 3×1020 Pas and lower mantle values of 1022, 3×1022 and 5×1022 Pas. Concerning the properties of the melt layer itself, a thin (1 km) layer may have any of the investigated viscosities (1015 to 1019 Pas). For thicker melt layers, the viscosity must be ≥1018 Pas (20 km) or ≥1017 Pas (10 km). Our results indicate clear parameter trade-offs between the properties of the melt layer and the background viscosity structure. Given that the observations permit several values of lower mantle viscosity, we conclude that tightening constraints on this parameter would be valuable for future investigation of the type presented here. Furthermore, while decay times from both locations considered in this investigation (Ångerman River, Sweden; Richmond Gulf, Canada) offer meaningful constraints on viscosity structure, the value for Richmond Gulf is significantly more uncertain and so increasing its precision would likely result in improved viscosity constraints.

An intercomparison of stratospheric gravity wave potential energy densities from METOP GPS radio occultation measurements and ECMWF model data

NASA Astrophysics Data System (ADS)

Rapp, Markus; Dörnbrack, Andreas; Kaifler, Bernd

2018-02-01

Temperature profiles based on radio occultation (RO) measurements with the operational European METOP satellites are used to derive monthly mean global distributions of stratospheric (20-40 km) gravity wave (GW) potential energy densities (EP) for the period July 2014-December 2016. In order to test whether the sampling and data quality of this data set is sufficient for scientific analysis, we investigate to what degree the METOP observations agree quantitatively with ECMWF operational analysis (IFS data) and reanalysis (ERA-Interim) data. A systematic comparison between corresponding monthly mean temperature fields determined for a latitude-longitude-altitude grid of 5° by 10° by 1 km is carried out. This yields very low systematic differences between RO and model data below 30 km (i.e., median temperature differences is between -0.2 and +0.3 K), which increases with height to yield median differences of +1.0 K at 34 km and +2.2 K at 40 km. Comparing EP values for three selected locations at which also ground-based lidar measurements are available yields excellent agreement between RO and IFS data below 35 km. ERA-Interim underestimates EP under conditions of strong local mountain wave forcing over northern Scandinavia which is apparently not resolved by the model. Above 35 km, RO values are consistently much larger than model values, which is likely caused by the model sponge layer, which damps small-scale fluctuations above ˜ 32 km altitude. Another reason is the well-known significant increase of noise in RO measurements above 35 km. The comparison between RO and lidar data reveals very good qualitative agreement in terms of the seasonal variation of EP, but RO values are consistently smaller than lidar values by about a factor of 2. This discrepancy is likely caused by the very different sampling characteristics of RO and lidar observations. Direct comparison of the global data set of RO and model EP fields shows large correlation coefficients (0.4-1.0) with a general degradation with increasing altitude. Concerning absolute differences between observed and modeled EP values, the median difference is relatively small at all altitudes (but increasing with altitude) with an exception between 20 and 25 km, where the median difference between RO and model data is increased and the corresponding variability is also found to be very large. The reason for this is identified as an artifact of the EP algorithm: this erroneously interprets the pronounced climatological feature of the tropical tropopause inversion layer (TTIL) as GW activity, hence yielding very large EP values in this area and also large differences between model and observations. This is because the RO data show a more pronounced TTIL than IFS and ERA-Interim. We suggest a correction for this effect based on an estimate of this artificial EP using monthly mean zonal mean temperature profiles. This correction may be recommended for application to data sets that can only be analyzed using a vertical background determination method such as the METOP data with relatively scarce sampling statistics. However, if the sampling statistics allows, our analysis also shows that in general a horizontal background determination is advantageous in that it better avoids contributions to EP that are not caused by gravity waves.

Particle and carbon dioxide emissions from passenger vehicles operating on unleaded petrol and LPG fuel.

PubMed

Ristovski, Z D; Jayaratne, E R; Morawska, L; Ayoko, G A; Lim, M

2005-06-01

A comprehensive study of the particle and carbon dioxide emissions from a fleet of six dedicated liquefied petroleum gas (LPG) powered and five unleaded petrol (ULP) powered new Ford Falcon Forte passenger vehicles was carried out on a chassis dynamometer at four different vehicle speeds--0 (idle), 40, 60, 80 and 100 km h(-1). Emission factors and their relative values between the two fuel types together with a statistical significance for any difference were estimated for each parameter. In general, LPG was found to be a 'cleaner' fuel, although in most cases, the differences were not statistically significant owing to the large variations between emissions from different vehicles. The particle number emission factors ranged from 10(11) to 10(13) km(-1) and was over 70% less with LPG compared to ULP. Corresponding differences in particle mass emission factor between the two fuels were small and ranged from the order of 10 microg km(-1) at 40 to about 1000 microg km(-1) at 100 km h(-1). The count median particle diameter (CMD) ranged from 20 to 35 nm and was larger with LPG than with ULP in all modes except the idle mode. Carbon dioxide emission factors ranged from about 300 to 400 g km(-1) at 40 km h(-1), falling with increasing speed to about 200 g km(-1) at 100 km h(-1). At all speeds, the values were 10% to 18% greater with ULP than with LPG.

Functional traits help to explain half-century long shifts in pollinator distributions.

PubMed

Aguirre-Gutiérrez, Jesús; Kissling, W Daniel; Carvalheiro, Luísa G; WallisDeVries, Michiel F; Franzén, Markus; Biesmeijer, Jacobus C

2016-04-15

Changes in climate and land use can have important impacts on biodiversity. Species respond to such environmental modifications by adapting to new conditions or by shifting their geographic distributions towards more suitable areas. The latter might be constrained by species' functional traits that influence their ability to move, reproduce or establish. Here, we show that functional traits related to dispersal, reproduction, habitat use and diet have influenced how three pollinator groups (bees, butterflies and hoverflies) responded to changes in climate and land-use in the Netherlands since 1950. Across the three pollinator groups, we found pronounced areal range expansions (>53%) and modelled range shifts towards the north (all taxa: 17-22 km), west (bees: 14 km) and east (butterflies: 11 km). The importance of specific functional traits for explaining distributional changes varied among pollinator groups. Larval diet preferences (i.e. carnivorous vs. herbivorous/detritivorous and nitrogen values of host plants, respectively) were important for hoverflies and butterflies, adult body size for hoverflies, and flight period length for all groups. Moreover, interactions among multiple traits were important to explain species' geographic range shifts, suggesting that taxon-specific multi-trait analyses are needed to predict how global change will affect biodiversity and ecosystem services.

Environmental concern-based site screening of carbon dioxide geological storage in China.

PubMed

Cai, Bofeng; Li, Qi; Liu, Guizhen; Liu, Lancui; Jin, Taotao; Shi, Hui

2017-08-08

Environmental impacts and risks related to carbon dioxide (CO 2 ) capture and storage (CCS) projects may have direct effects on the decision-making process during CCS site selection. This paper proposes a novel method of environmental optimization for CCS site selection using China's ecological red line approach. Moreover, this paper established a GIS based spatial analysis model of environmental optimization during CCS site selection by a large database. The comprehensive data coverage of environmental elements and fine 1 km spatial resolution were used in the database. The quartile method was used for value assignment for specific indicators including the prohibited index and restricted index. The screening results show that areas classified as having high environmental suitability (classes III and IV) in China account for 620,800 km 2 and 156,600 km 2 , respectively, and are mainly distributed in Inner Mongolia, Qinghai and Xinjiang. The environmental suitability class IV areas of Bayingol Mongolian Autonomous Prefecture, Hotan Prefecture, Aksu Prefecture, Hulunbuir, Xilingol League and other prefecture-level regions not only cover large land areas, but also form a continuous area in the three provincial-level administrative units. This study may benefit the national macro-strategic deployment and implementation of CCS spatial layout and environmental management in China.

Enzymatic synthesis of dithiolopyrrolone antibiotics using cell-free extract of Saccharothrix algeriensis NRRL B-24137 and biochemical characterization of two pyrrothine N-acyltransferases in this extract.

PubMed

Saker, Safwan; Almousa Almaksour, Ziade; Chorin, Anne-Claire; Lebrihi, Ahmed; Mathieu, Florence

2014-01-01

Saccharothrix algeriensis NRRL B-24137 produces naturally different dithiolopyrrolone derivatives. The enzymatic activity of pyrrothine N-acyltransferase was determined to be responsible for the transfer of an acyl group from acyl-CoA to pyrrothine core. This activity was also reported to be responsible for the diversity of the dithiolopyrrolone derivatives. Based on this fact, nine dithiolopyrrolone derivatives were produced in vitro via the crude extract of Sa. algeriensis. Three of them have never been obtained before by natural fermentation: acetoacetyl-pyrrothine, hydroxybutyryl-pyrrothine, and dimethyl thiolutin (holomycin). Two acyltransferase activities, acetyltransferase and benzoyltransferase catalyzing the incorporation of linear and cyclic acyl groups to the pyrrothine core, respectively, were biochemically characterized in this crude extract. The first one is responsible for formation of acetyl-pyrrothine and the second for benzoyl-pyrrothine. Both enzymes were sensitive to temperature changes: For example, the loss of acetyltransferase and benzoyltransferase activity was 53% and 80% respectively after pre-incubation of crude extract for 60 min at 20°C. The two enzymes were more active in neutral and basal media (pH 7-10) than in the acidic one (pH 3-6). The optimum temperature and pH of acetyltransferase were 40°C and 7, with a Km value of 7.9 μM and a Vmax of 0.63 μM/min when acetyl-CoA was used as limited substrate. Benzoyltransferase had a temperature and a pH optimum at 55°C and 9, a Km value of 14.7 μM, and a Vmax of 0.67 μM/min when benzoyl- CoA was used as limited substrate.

A chlorogenic acid esterase with a unique substrate specificity from Ustilago maydis.

PubMed

Nieter, Annabel; Haase-Aschoff, Paul; Kelle, Sebastian; Linke, Diana; Krings, Ulrich; Popper, Lutz; Berger, Ralf G

2015-03-01

An extracellular chlorogenic acid esterase from Ustilago maydis (UmChlE) was purified to homogeneity by using three separation steps, including anion-exchange chromatography on a Q Sepharose FF column, preparative isoelectric focusing (IEF), and, finally, a combination of affinity chromatography and hydrophobic interaction chromatography on polyamide. SDS-PAGE analysis suggested a monomeric protein of ∼71 kDa. The purified enzyme showed maximal activity at pH 7.5 and at 37°C and was active over a wide pH range (3.5 to 9.5). Previously described chlorogenic acid esterases exhibited a comparable affinity for chlorogenic acid, but the enzyme from Ustilago was also active on typical feruloyl esterase substrates. Kinetic constants for chlorogenic acid, methyl p-coumarate, methyl caffeate, and methyl ferulate were as follows: Km values of 19.6 μM, 64.1 μM, 72.5 μM, and 101.8 μM, respectively, and kcat/Km values of 25.83 mM(-1) s(-1), 7.63 mM(-1) s(-1), 3.83 mM(-1) s(-1) and 3.75 mM(-1) s(-1), respectively. UmChlE released ferulic, p-coumaric, and caffeic acids from natural substrates such as destarched wheat bran (DSWB) and coffee pulp (CP), confirming activity on complex plant biomass. The full-length gene encoding UmChlE consisted of 1,758 bp, corresponding to a protein of 585 amino acids, and was functionally produced in Pichia pastoris GS115. Sequence alignments with annotated chlorogenic acid and feruloyl esterases underlined the uniqueness of this enzyme. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Effects of Bacterial Host and Dichloromethane Dehalogenase on the Competitiveness of Methylotrophic Bacteria Growing with Dichloromethane

PubMed Central

Gisi, Daniel; Willi, Laurent; Traber, Hubert; Leisinger, Thomas; Vuilleumier, Stéphane

1998-01-01

Methylobacterium sp. strain DM4 and Methylophilus sp. strain DM11 can grow with dichloromethane (DCM) as the sole source of carbon and energy by virtue of homologous glutathione-dependent DCM dehalogenases with markedly different kinetic properties (the kcat values of the enzymes of these strains are 0.6 and 3.3 s−1, respectively, and the Km values are 9 and 59 μM, respectively). These strains, as well as transconjugant bacteria expressing the DCM dehalogenase gene (dcmA) from DM11 or DM4 on a broad-host-range plasmid in the background of dcmA mutant DM4-2cr, were investigated by growing them under growth-limiting conditions and in the presence of an excess of DCM. The maximal growth rates and maximal levels of dehalogenase for chemostat-adapted bacteria were higher than the maximal growth rates and maximal levels of dehalogenase for batch-grown bacteria. The substrate saturation constant of strain DM4 was much lower than the Km of its associated dehalogenase, suggesting that this strain is adapted to scavenge low concentrations of DCM. Strains and transconjugants expressing the DCM dehalogenase from strain DM11, on the other hand, had higher growth rates than bacteria expressing the homologous dehalogenase from strain DM4. Competition experiments performed with pairs of DCM-degrading strains revealed that a strain expressing the dehalogenase from DM4 had a selective advantage in continuous culture under substrate-limiting conditions, while strains expressing the DM11 dehalogenase were superior in batch culture when there was an excess of substrate. Only DCM-degrading bacteria with a dcmA gene similar to that from strain DM4, however, were obtained in batch enrichment cultures prepared with activated sludge from sewage treatment plants. PMID:9546153

Mountain-Top-to-Mountain-Top Optical Link Demonstration. Part 1

NASA Technical Reports Server (NTRS)

Biswas, A.; Wright, M. W.

2002-01-01

A mountain-top-to-mountain-top optical link was demonstrated between JPL's Table Mountain Facility (TMF), Wrightwood, California, and Strawberry Peak (SP), Lake Arrowhead, California, during the months of June, August, and September of 2000. The bidirectional laser link was nearly horizontal at an altitude of 2 km and spanned a range of 46.8 km. The 780-nm beacon laser transmitted from TMF comprised eight co-propagating mutually incoherent laser beams. The normalized variance or scintillation index (SI) of the individual beacon lasers measured by recording the signal received through 8.50-cm-diameter spotting telescopes on three different nights (June 28-30, 2000) was 1.05 +/- 0.2, 1.76 +/- 0.6, and 0.96 +/- 0.24, respectively. These measurements agreed with values predicted by a heuristic model. The SI of the signal received at SP was found to decrease progressively with an increasing number of beams, and a factor of 3 to 3.5 reduction was achieved for all eight beams. The beam divergence determined by mapping out the point spread function of a few of the individual laser footprints received at SP was 85 to 150 microrad, compared to a design goal of 120 microrad. The 852-nm communications laser beam received at TMF through a 60-cm-diameter telescope on the nights of August 4 and September 14 and 15, 2000, yielded SI values of 0.23 +/- 0.04, 0.32 +/- 0.01, and 0.49 +/- 0.18, respectively, where the reduction was attributed to aperture averaging. The probability distribution functions of the received signal at either end, mitigated by multi-beam averaging in one direction and by aperture averaging in the other direction, displayed lognormal behavior. Consequently, the measured fade statistics showed good agreement with a lognormal model.

Kinetic Characterization and Allosteric Inhibition of the Yersinia pestis 1-Deoxy-D-Xylulose 5-Phosphate Reductoisomerase (MEP Synthase)

PubMed Central

Haymond, Amanda; Johny, Chinchu; Dowdy, Tyrone; Schweibenz, Brandon; Villarroel, Karen; Young, Richard; Mantooth, Clark J.; Patel, Trishal; Bases, Jessica; Jose, Geraldine San; Jackson, Emily R.; Dowd, Cynthia S.; Couch, Robin D.

2014-01-01

The methylerythritol phosphate (MEP) pathway found in many bacteria governs the synthesis of isoprenoids, which are crucial lipid precursors for vital cell components such as ubiquinone. Because mammals synthesize isoprenoids via an alternate pathway, the bacterial MEP pathway is an attractive target for novel antibiotic development, necessitated by emerging antibiotic resistance as well as biodefense concerns. The first committed step in the MEP pathway is the reduction and isomerization of 1-deoxy-D-xylulose-5-phosphate (DXP) to methylerythritol phosphate (MEP), catalyzed by MEP synthase. To facilitate drug development, we cloned, expressed, purified, and characterized MEP synthase from Yersinia pestis. Enzyme assays indicate apparent kinetic constants of KM DXP = 252 µM and KM NADPH = 13 µM, IC50 values for fosmidomycin and FR900098 of 710 nM and 231 nM respectively, and Ki values for fosmidomycin and FR900098 of 251 nM and 101 nM respectively. To ascertain if the Y. pestis MEP synthase was amenable to a high-throughput screening campaign, the Z-factor was determined (0.9) then the purified enzyme was screened against a pilot scale library containing rationally designed fosmidomycin analogs and natural product extracts. Several hit molecules were obtained, most notably a natural product allosteric affector of MEP synthase and a rationally designed bisubstrate derivative of FR900098 (able to associate with both the NADPH and DXP binding sites in MEP synthase). It is particularly noteworthy that allosteric regulation of MEP synthase has not been described previously. Thus, our discovery implicates an alternative site (and new chemical space) for rational drug development. PMID:25171339

Identification of the putrescine biosynthetic genes in Pseudomonas aeruginosa and characterization of agmatine deiminase and N-carbamoylputrescine amidohydrolase of the arginine decarboxylase pathway.

PubMed

Nakada, Yuji; Itoh, Yoshifumi

2003-03-01

Putrescine can be synthesized either directly from ornithine by ornithine decarboxylase (ODC; the speC product) or indirectly from arginine via arginine decarboxylase (ADC; the speA product). The authors identified the speA and speC genes in Pseudomonas aeruginosa PAO1. The activities of the two decarboxylases were similar and each enzyme alone appeared to direct sufficient formation of the polyamine for normal growth. A mutant defective in both speA and speC was a putrescine auxotroph. In this strain, agmatine deiminase (the aguA product) and N-carbamoylputrescine amidohydrolase (the aguB product), which were initially identified as the catabolic enzymes of agmatine, biosynthetically convert agmatine to putrescine in the ADC pathway: a double mutant of aguAB and speC was a putrescine auxotroph. AguA was purified as a homodimer of 43 kDa subunits and AguB as a homohexamer of 33 kDa subunits. AguA specifically deiminated agmatine with K(m) and K(cat) values of 0.6 mM and 4.2 s(-1), respectively. AguB was specific to N-carbamoylputrescine and the K(m) and K(cat) values of the enzyme for the substrate were 0.5 mM and 3.3 s(-1), respectively. Whereas AguA has no structural relationship to any known C-N hydrolases, AguB is a protein of the nitrilase family that performs thiol-assisted catalysis. Inhibition by SH reagents and the conserved cysteine residue in AguA and its homologues suggested that this enzyme is also involved in thiol-mediated catalysis.

Performance of the Multi-Radar Multi-Sensor System over the Lower Colorado River, Texas

NASA Astrophysics Data System (ADS)

Bayabil, H. K.; Sharif, H. O.; Fares, A.; Awal, R.; Risch, E.

2017-12-01

Recently observed increases in intensities and frequencies of climate extremes (e.g., floods, dam failure, and overtopping of river banks) necessitate the development of effective disaster prevention and mitigation strategies. Hydrologic models can be useful tools in predicting such events at different spatial and temporal scales. However, accuracy and prediction capability of such models are often constrained by the availability of high-quality representative hydro-meteorological data (e.g., precipitation) that are required to calibrate and validate such models. Improved technologies and products such as the Multi-Radar Multi-Sensor (MRMS) system that allows gathering and transmission of vast meteorological data have been developed to provide such data needs. While the MRMS data are available with high spatial and temporal resolutions (1 km and 15 min, respectively), its accuracy in estimating precipitation is yet to be fully investigated. Therefore, the main objective of this study is to evaluate the performance of the MRMS system in effectively capturing precipitation over the Lower Colorado River, Texas using observations from a dense rain gauge network. In addition, effects of spatial and temporal aggregation scales on the performance of the MRMS system were evaluated. Point scale comparisons were made at 215 gauging locations using rain gauges and MRMS data from May 2015. Moreover, the effects of temporal and spatial data aggregation scales (30, 45, 60, 75, 90, 105, and 120 min) and (4 to 50 km), respectively on the performance of the MRMS system were tested. Overall, the MRMS system (at 15 min temporal resolution) captured precipitation reasonably well, with an average R2 value of 0.65 and RMSE of 0.5 mm. In addition, spatial and temporal data aggregations resulted in increases in R2 values. However, reduction in RMSE was achieved only with an increase in spatial aggregations.

Na+/Taurocholate Cotransporting Polypeptide and Apical Sodium-Dependent Bile Acid Transporter Are Involved in the Disposition of Perfluoroalkyl Sulfonates in Humans and Rats

PubMed Central

Zhao, Wen; Zitzow, Jeremiah D.; Ehresman, David J.; Chang, Shu-Ching; Butenhoff, John L.; Forster, Jameson; Hagenbuch, Bruno

2015-01-01

Among the perfluoroalkyl sulfonates (PFASs), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) have half-lives of several years in humans, mainly due to slow renal clearance and potential hepatic accumulation. Both compounds undergo enterohepatic circulation. To determine whether transporters involved in the enterohepatic circulation of bile acids are also involved in the disposition of PFASs, uptake of perfluorobutane sulfonate (PFBS), PFHxS, and PFOS was measured using freshly isolated human and rat hepatocytes in the absence or presence of sodium. The results demonstrated sodium-dependent uptake for all 3 PFASs. Given that the Na+/taurocholate cotransporting polypeptide (NTCP) and the apical sodium-dependent bile salt transporter (ASBT) are essential for the enterohepatic circulation of bile acids, transport of PFASs was investigated in stable CHO Flp-In cells for human NTCP or HEK293 cells transiently expressing rat NTCP, human ASBT, and rat ASBT. The results demonstrated that both human and rat NTCP can transport PFBS, PFHxS, and PFOS. Kinetics with human NTCP revealed Km values of 39.6, 112, and 130 µM for PFBS, PFHxS, and PFOS, respectively. For rat NTCP Km values were 76.2 and 294 µM for PFBS and PFHxS, respectively. Only PFOS was transported by human ASBT whereas rat ASBT did not transport any of the tested PFASs. Human OSTα/β was also able to transport all 3 PFASs. In conclusion, these results suggest that the long half-live and the hepatic accumulation of PFOS in humans are at least, in part, due to transport by NTCP and ASBT. PMID:26001962

SAGE III solar ozone measurements: Initial results

NASA Technical Reports Server (NTRS)

Wang, Hsiang-Jui; Cunnold, Derek M.; Trepte, Chip; Thomason, Larry W.; Zawodny, Joseph M.

2006-01-01

Results from two retrieval algorithms, o3-aer and o3-mlr , used for SAGE III solar occultation ozone measurements in the stratosphere and upper troposphere are compared. The main differences between these two retrieved (version 3.0) ozone are found at altitudes above 40 km and below 15 km. Compared to correlative measurements, the SAGE II type ozone retrievals (o3-aer) provide better precisions above 40 km and do not induce artificial hemispheric differences in upper stratospheric ozone. The multiple linear regression technique (o3_mlr), however, can yield slightly more accurate ozone (by a few percent) in the lower stratosphere and upper troposphere. By using SAGE III (version 3.0) ozone from both algorithms and in their preferred regions, the agreement between SAGE III and correlative measurements is shown to be approx.5% down to 17 km. Below 17 km SAGE III ozone values are systematically higher, by 10% at 13 km, and a small hemispheric difference (a few percent) appears. Compared to SAGE III and HALOE, SAGE II ozone has the best accuracy in the lowest few kilometers of the stratosphere. Estimated precision in SAGE III ozone is about 5% or better between 20 and 40 km and approx.10% at 50 km. The precision below 20 km is difficult to evaluate because of limited coincidences between SAGE III and sondes. SAGE III ozone values are systematically slightly larger (2-3%) than those from SAGE II but the profile shapes are remarkably similar for altitudes above 15 km. There is no evidence of any relative drift or time dependent differences between these two instruments for altitudes above 15-20 km.

Comparison of ventilation threshold and heart rate deflection point in fast and standard treadmill test protocols.

PubMed

Vucetić, Vlatko; Sentija, Davor; Sporis, Goran; Trajković, Nebojsa; Milanović, Zoran

2014-06-01

The purpose of this study was to compare two methods for determination of anaerobic threshold from two different treadmill protocols. Forty-eight Croatian runners of national rank (ten sprinters, fifteen 400-m runners, ten middle distance runners and thirteen long distance runners), mean age 21.7 +/- 5.1 years, participated in the study. They performed two graded maximal exercise tests on a treadmill, a standard ramp treadmill test (T(SR), speed increments of 1 km x h(-1) every 60 seconds) and a fast ramp treadmill test (T(FR), speed increments of 1 km x h(-1) every 30 seconds) to determine and compare the parameters at peak values and at heart rate at the deflection point (HR(DP)) and ventilation threshold (VT). There were no significant differences between protocols (p > 0.05) for peak values of oxygen uptake (VO(2max), 4.48 +/- 0.43 and 4.44 +/- 0.45 L x min(-1)), weight related VO(2max) (62.5 +/- 6.2 and 62.0 +/- 6.0 mL x kg(-1) x min(-1)), pulmonary ventilation (VE(max), 163.1 +/- 18.7 and 161.3 +/- 19.9 L x min(-1)) and heart rate (HR(max), 192.3 +/- 8.5 and 194.4 +/- 8.7 bpm) (T(FR) and T(SR), respectively). Moreover, no significant differences between T(FR) and T(SR) where found for VT and HR(DP) when expressed as VO2 and HR. However, there was a significant effect of ramp slope on running speed at VO(2max) and at the anaerobic threshold (AnT), independent of the method used (VT: 16.0 +/- 2.2 vs 14.9 +/- 2.2 km x h(-1);HR(DP): 16.5 +/- 1.9 vs 14.9 +/- 2.0 km x h(-1) for T(FR) and T(SR) respectively). Linear regression analysis revealed high between-test and between-method correlations for VO2, HR and running speed parameters (r = 0.78-0.89, p < 0.01). The present study has indicated that the VT and HR(DP) for running (VO2, ventilation, and heart rate at VT/HR(DP)) are independent of test protocol, while there is a significant effect of ramp slope on VT and HR(DP) when expressed as running speed. Moreover, this study demonstrates that the point of deflection from linearity of heart rate may be an accurate predictor of the anaerobic threshold in trained runners, independently of the protocol used.

Monitoring groundwater storage changes in the highly seasonal humid tropics: Validation of GRACE measurements in the Bengal Basin

NASA Astrophysics Data System (ADS)

Shamsudduha, M.; Taylor, R. G.; Longuevergne, L.

2012-02-01

Satellite monitoring of changes in terrestrial water storage provides invaluable information regarding the basin-scale dynamics of hydrological systems where ground-based records are limited. In the Bengal Basin of Bangladesh, we test the ability of satellite measurements under the Gravity Recovery and Climate Experiment (GRACE) to trace both the seasonality and trend in groundwater storage associated with intensive groundwater abstraction for dry-season irrigation and wet-season (monsoonal) recharge. We show that GRACE (CSR, GRGS) datasets of recent (2003 to 2007) groundwater storage changes (ΔGWS) correlate well (r = 0.77 to 0.93, p value < 0.0001) with in situ borehole records from a network of 236 monitoring stations and account for 44% of the total variation in terrestrial water storage (ΔTWS); highest correlation (r = 0.93, p value < 0.0001) and lowest root-mean-square error (<4 cm) are realized using a spherical harmonic product of CSR. Changes in surface water storage estimated from a network of 298 river gauging stations and soil-moisture derived from Land Surface Models explain 22% and 33% of ΔTWS, respectively. Groundwater depletion estimated from borehole hydrographs (-0.52 ± 0.30 km3 yr-1) is within the range of satellite-derived estimates (-0.44 to -2.04 km3 yr-1) that result from uncertainty associated with the simulation of soil moisture (CLM, NOAH, VIC) and GRACE signal-processing techniques. Recent (2003 to 2007) estimates of groundwater depletion are substantially greater than long-term (1985 to 2007) mean (-0.21 ± 0.03 km3 yr-1) and are explained primarily by substantial increases in groundwater abstraction for the dry-season irrigation and public water supplies over the last two decades.

P and S velocity structure of the crust and the upper mantle beneath central Java from local tomography inversion

NASA Astrophysics Data System (ADS)

Koulakov, I.; Bohm, M.; Asch, G.; Lühr, B.-G.; Manzanares, A.; Brotopuspito, K. S.; Fauzi, Pak; Purbawinata, M. A.; Puspito, N. T.; Ratdomopurbo, A.; Kopp, H.; Rabbel, W.; Shevkunova, E.

2007-08-01

Here we present the results of local source tomographic inversion beneath central Java. The data set was collected by a temporary seismic network. More than 100 stations were operated for almost half a year. About 13,000 P and S arrival times from 292 events were used to obtain three-dimensional (3-D) Vp, Vs, and Vp/Vs models of the crust and the mantle wedge beneath central Java. Source location and determination of the 3-D velocity models were performed simultaneously based on a new iterative tomographic algorithm, LOTOS-06. Final event locations clearly image the shape of the subduction zone beneath central Java. The dipping angle of the slab increases gradually from almost horizontal to about 70°. A double seismic zone is observed in the slab between 80 and 150 km depth. The most striking feature of the resulting P and S models is a pronounced low-velocity anomaly in the crust, just north of the volcanic arc (Merapi-Lawu anomaly (MLA)). An algorithm for estimation of the amplitude value, which is presented in the paper, shows that the difference between the fore arc and MLA velocities at a depth of 10 km reaches 30% and 36% in P and S models, respectively. The value of the Vp/Vs ratio inside the MLA is more than 1.9. This shows a probable high content of fluids and partial melts within the crust. In the upper mantle we observe an inclined low-velocity anomaly which links the cluster of seismicity at 100 km depth with MLA. This anomaly might reflect ascending paths of fluids released from the slab. The reliability of all these patterns was tested thoroughly.

Normalization of elevated cardiac, kidney, and hemolysis plasma markers within 48 h in Mexican Tarahumara runners following a 78 km race at moderate altitude.

PubMed

Christensen, Dirk L; Espino, Diana; Infante-Ramírez, Rocío; Brage, Soren; Terzic, Dijana; Goetze, Jens P; Kjaergaard, Jesper

2014-01-01

The aim of this study was to examine to what extent extreme endurance exercise results in changes of plasma markers associated with cardiac and renal damage, as well as hemolysis in male, Mexican Tarahumara runners. Ten Tarahumara runners (mean (sd) age of 38 (12) years) participated in a 78 km race in Chihuahua, Mexico at 2,400 m above sea level. Cardiac, kidney, and hematology plasma markers were measured pre-race and <5 min, 1 h, 3 h, 6 h, 24 h, and 48 h post-race. Anthropometry, blood pressure, pulse rate, electrocardiography, HbA1c, hemoglobin and VO2max (estimated from heart rate following step test) were assessed pre-race, while physical activity energy expenditure and intensity were estimated during the race, and oxygen partial pressure saturation (SpO2 ) <30 min post-race. Estimated mean VO2max was 48 (9) mLO2 min(-1) kg(-1) and relative intensity during the race was 68 (11)%VO2 max. Mean SpO2 was 92 (3)% <30 min post-race. Plasma concentrations of especially total creatine kinase, creatine kinase-MB isoform, and haptoglobin changed significantly from pre-race values (P < 0.001) up to 24 h post-race, but had returned to pre-race values after 48 h. The plasma concentrations of mid-regional proatrial natiuretic peptide and copeptin returned to pre-race concentrations after 1 and 6 h, respectively. Altered cardiac, renal, and hemolysis plasma markers were normalized after 48 h following 78 km of running, suggesting that the impact of exercise-induced cardiac and kidney damage as well as hemolysis in the Mexican Tarahumara is low. © 2014 Wiley Periodicals, Inc.

Open-source sea ice drift algorithm for Sentinel-1 SAR imagery using a combination of feature-tracking and pattern-matching

NASA Astrophysics Data System (ADS)

Muckenhuber, Stefan; Sandven, Stein

2017-04-01

An open-source sea ice drift algorithm for Sentinel-1 SAR imagery is introduced based on the combination of feature-tracking and pattern-matching. A computational efficient feature-tracking algorithm produces an initial drift estimate and limits the search area for the pattern-matching, that provides small to medium scale drift adjustments and normalised cross correlation values as quality measure. The algorithm is designed to utilise the respective advantages of the two approaches and allows drift calculation at user defined locations. The pre-processing of the Sentinel-1 data has been optimised to retrieve a feature distribution that depends less on SAR backscatter peak values. A recommended parameter set for the algorithm has been found using a representative image pair over Fram Strait and 350 manually derived drift vectors as validation. Applying the algorithm with this parameter setting, sea ice drift retrieval with a vector spacing of 8 km on Sentinel-1 images covering 400 km x 400 km, takes less than 3.5 minutes on a standard 2.7 GHz processor with 8 GB memory. For validation, buoy GPS data, collected in 2015 between 15th January and 22nd April and covering an area from 81° N to 83.5° N and 12° E to 27° E, have been compared to calculated drift results from 261 corresponding Sentinel-1 image pairs. We found a logarithmic distribution of the error with a peak at 300 m. All software requirements necessary for applying the presented sea ice drift algorithm are open-source to ensure free implementation and easy distribution.

Observational characteristics of the tropopause inversion layer derived from CHAMP/GRACE radio occultations and MOZAIC aircraft data

NASA Astrophysics Data System (ADS)

Schmidt, T.; Cammas, J.-P.; Smit, H. G. J.; Heise, S.; Wickert, J.; Haser, A.

2010-12-01

In this study we discuss characteristics of the Northern Hemisphere (NH) midlatitude (40°N-60°N) tropopause inversion layer (TIL) based on two data sets. First, temperature measurements from GPS radio occultation data (CHAMP and GRACE) for the time interval 2001-2009 are used to exhibit seasonal properties of the TIL bottom height defined here as the height of the squared buoyancy frequency minimum N2 below the thermal tropopause, the TIL maximum height as the height of the N2 maximum above the tropopause, and the TIL top height as the height of the temperature maximum above the tropopause. Mean values of the TIL bottom, TIL maximum, and TIL top heights relative to the thermal tropopause for the NH midlatitudes are (-2.08 ± 0.35) km, (0.52 ± 0.10) km and (2.10 ± 0.23) km, respectively. A seasonal cycle of the TIL bottom and TIL top height is observed with values closer to the thermal tropopause during summer. Secondly, high-resolution temperature and trace gas profile measurements on board commercial aircrafts (Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) program) from 2001-2008 for the NH midlatitude (40°N-60°N) region are used to characterize the TIL as a mixing layer around the tropopause. Mean TIL bottom, TIL maximum, and TIL top heights based on the MOZAIC temperature (N2) measurements confirm the results from the GPS data, even though most of the MOZAIC profiles used here are available under cyclonic situations. Further, we demonstrate that the mixing ratio gradients of ozone (O3) and carbon monoxide (CO) are suitable parameters for characterizing the TIL structure.

Geospatial distribution modeling and determining suitability of groundwater quality for irrigation purpose using geospatial methods and water quality index (WQI) in Northern Ethiopia

NASA Astrophysics Data System (ADS)

Gidey, Amanuel

2018-06-01

Determining suitability and vulnerability of groundwater quality for irrigation use is a key alarm and first aid for careful management of groundwater resources to diminish the impacts on irrigation. This study was conducted to determine the overall suitability of groundwater quality for irrigation use and to generate their spatial distribution maps in Elala catchment, Northern Ethiopia. Thirty-nine groundwater samples were collected to analyze and map the water quality variables. Atomic absorption spectrophotometer, ultraviolet spectrophotometer, titration and calculation methods were used for laboratory groundwater quality analysis. Arc GIS, geospatial analysis tools, semivariogram model types and interpolation methods were used to generate geospatial distribution maps. Twelve and eight water quality variables were used to produce weighted overlay and irrigation water quality index models, respectively. Root-mean-square error, mean square error, absolute square error, mean error, root-mean-square standardized error, measured values versus predicted values were used for cross-validation. The overall weighted overlay model result showed that 146 km2 areas are highly suitable, 135 km2 moderately suitable and 60 km2 area unsuitable for irrigation use. The result of irrigation water quality index confirms 10.26% with no restriction, 23.08% with low restriction, 20.51% with moderate restriction, 15.38% with high restriction and 30.76% with the severe restriction for irrigation use. GIS and irrigation water quality index are better methods for irrigation water resources management to achieve a full yield irrigation production to improve food security and to sustain it for a long period, to avoid the possibility of increasing environmental problems for the future generation.

Use of Mechanistic Modeling to Assess Interindividual Variability and Interspecies Differences in Active Uptake in Human and Rat Hepatocytes

PubMed Central

Ménochet, Karelle; Kenworthy, Kathryn E.; Houston, J. Brian

2012-01-01

Interindividual variability in activity of uptake transporters is evident in vivo, yet limited data exist in vitro, confounding in vitro-in vivo extrapolation. The uptake kinetics of seven organic anion-transporting polypeptide substrates was investigated over a concentration range in plated cryopreserved human hepatocytes. Active uptake clearance (CLactive, u), bidirectional passive diffusion (Pdiff), intracellular binding, and metabolism were estimated for bosentan, pitavastatin, pravastatin, repaglinide, rosuvastatin, telmisartan, and valsartan in HU4122 donor using a mechanistic two-compartment model in Matlab. Full uptake kinetics of rosuvastatin and repaglinide were also characterized in two additional donors, whereas for the remaining drugs CLactive, u was estimated at a single concentration. The unbound affinity constant (Km, u) and Pdiff values were consistent across donors, whereas Vmax was on average up to 2.8-fold greater in donor HU4122. Consistency in Km, u values allowed extrapolation of single concentration uptake activity data and assessment of interindividual variability in CLactive across donors. The maximal contribution of active transport to total uptake differed among donors, for example, 85 to 96% and 68 to 87% for rosuvastatin and repaglinide, respectively; however, in all cases the active process was the major contributor. In vitro-in vivo extrapolation indicated a general underprediction of hepatic intrinsic clearance, an average empirical scaling factor of 17.1 was estimated on the basis of seven drugs investigated in three hepatocyte donors, and donor-specific differences in empirical factors are discussed. Uptake Km, u and CLactive, u were on average 4.3- and 7.1-fold lower in human hepatocytes compared with our previously published rat data. A strategy for the use of rat uptake data to facilitate the experimental design in human hepatocytes is discussed. PMID:22665271

Substrate recognition by the hetero-octameric ATP phosphoribosyltransferase from Lactococcus lactis†

PubMed Central

Champagne, Karen S.; Piscitelli, Elise; Francklyn, Christopher S.

2008-01-01

Two families of ATP phosphoribosyl transferases (ATP-PRT) join ATP and 5-phosphoribosyl-1 pyrophosphate (PRPP) in the first reaction of histidine biosynthesis. These consist of a homohexameric form found in all three kingdoms, and a hetero-octameric form largely restricted to bacteria. Hetero-octameric ATP-PRTs consist of four HisGS catalytic subunits related to periplasmic binding proteins, and four HisZ regulatory subunits that resemble histidyl-tRNA synthetases. To clarify the relationship between the two families of ATP-PRTs, and among phosphoribosyltransferases in general, we determined the steady state kinetics for the hetero-octameric form, and characterized the active site by mutagenesis. The Km PRPP (18.4 ± 3.5 μM) and kcat (2.7 ± 0.3 sec−1) values for the PRPP substrate are similar to those of hexameric ATP-PRTs, but the Km for ATP (2.7 ± 0.3 mM) is 4-fold higher, suggestive of tighter regulation by energy charge. Histidine and AMP were determined to be non-competitive (Ki = 81.1 μM) and competitive (Ki= 1.44 mM) inhibitors, respectively, with values that approximate their intracellular concentrations. Mutagenesis experiments investigating the side chains recognizing PRPP showed that 5′ phosphate contacts (T159A and T162A) had the largest (25- and 155-fold) decreases in kcat/Km, while smaller decreases were seen with mutants making cross subunit contacts (K50A and K8A) to the pyrophosphate moiety, or contacts to the 2′ OH. Despite their markedly different quaternary structures, hexameric and hetero-octameric ATRP-PRTs exhibit similar functional parameters, and employ mechanistic strategies reminiscent of the broader PRT superfamily. PMID:17154531

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Nicolas F.; Ibata, Rodrigo A.; Chambers, Kenneth C.

We present Keck II/DEIMOS spectroscopy of the three distant dwarf galaxies of M31 Lacerta I, Cassiopeia III, and Perseus I, recently discovered within the Pan-STARRS1 3π imaging survey. The systemic velocities of the three systems (v {sub r,} {sub helio} = –198.4 ± 1.1 km s{sup –1}, –371.6 ± 0.7 km s{sup –1}, and –326 ± 3 km s{sup –1}, respectively) confirm that they are satellites of M31. In the case of Lacerta I and Cassiopeia III, the high quality of the data obtained for 126 and 212 member stars, respectively, yields reliable constraints on their global velocity dispersions (σ{submore » vr} = 10.3 ± 0.9 km s{sup –1} and 8.4 ± 0.6 km s{sup –1}, respectively), leading to dynamical-mass estimates for both of ∼4 × 10{sup 7} M {sub ☉} within their half-light radius. These translate to V-band mass-to-light ratios of 15{sub −9}{sup +12} and 8{sub −5}{sup +9} in solar units. We also use our spectroscopic data to determine the average metallicity of the three dwarf galaxies ([Fe/H] = –2.0 ± 0.1, –1.7 ± 0.1, and –2.0 ± 0.2, respectively). All these properties are typical of dwarf galaxy satellites of Andromeda with their luminosity and size.« less

Trace element fluxes in sediments of an environmentally impacted river from a coastal zone of Brazil.

PubMed

da Silva, Yuri Jacques Agra Bezerra; Cantalice, José Ramon Barros; Singh, Vijay P; do Nascimento, Clístenes Williams Araújo; Piscoya, Victor Casimiro; Guerra, Sérgio M S

2015-10-01

Data regarding trace element concentrations and fluxes in suspended sediments and bedload are scarce. To fill this gap and meet the international need to include polluted rivers in future world estimation of trace element fluxes, this study aimed to determine the trace element fluxes in suspended sediment and bedload of an environmentally impacted river in Brazil. Water, suspended sediment, and bedload from both the upstream and the downstream cross sections were collected. To collect both the suspended sediment and water samples, we used the US DH-48. Bedload measurements were carried out using the US BLH 84 sampler. Concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were determined by inductively coupled plasma (ICP-OES). As and Hg were determined by an atomic absorption spectrophotometer (AA-FIAS). The suspended sediments contributed more than 99 % of the trace element flux. By far Pb and to a less extent Zn at the downstream site represents major concerns. The yields of Pb and Zn in suspended sediments were 4.20 and 2.93 kg km(2) year(-1), respectively. These yields were higher than the values reported for Pb and Zn for Tuul River (highly impacted by mining activities), 1.60 and 1.30 kg km(2) year(-1), respectively, as well as the Pb yield (suspended + dissolved) to the sea of some Mediterranean rivers equal to 3.4 kg km(2) year(-1). Therefore, the highest flux and yield of Pb and Zn in Ipojuca River highlighted the importance to include medium and small rivers-often overlooked in global and regional studies-in the future estimation of world trace element fluxes in order to protect estuaries and coastal zones.

CCD imaging and photometry of 46P/Wirtanen during October 1996

NASA Astrophysics Data System (ADS)

Fink, Uwe; Fevig, Ron A.; Tegler, Stephen C.; Romanishin, William

1997-11-01

During the period of 96 Oct. 7.16 to Oct. 12.14 comet P/Wirtanen was observed with our CCD system at the 154 cm Catalina Observatory telescope at a heliocentric distance near 2.1 AU. The comet exhibited a coma of about 7 in in diameter with a tail of about 14 in. The observed B, V and R magnitudes within a 9.3 in diameter aperture were 19.94, 19.11 and 18.73, respectively. The large majority of our observations were carried out with a filter combining the V and R passbands (V+R). The average V+R magnitudes for Oct. 7.16, 8.14, 9.12 and 10.15, respectively, were 18.91, 18.87, 18,87 and 18.86. The data did not allow the extraction of a lightcurve but hopefully can be used in conjunction with other observations to constrain the comet's rotation period. An attempt to separate the nucleus contribution from the coma resulted in an upper limit to the nuclear magnitude of ≈20.6 in V+R at a phase of 26° or ≈19.6 at 0° phase angle. This results in an upper limit of 1.2 km for the comet's radius assuming a geometric albedo of 0.04. Calculating the Afϱ yielded a value of 7 cm which is a factor of 170 smaller than P/Halley at a comparable heliocentric distance and phase angle. Making the simple assumption that the comet's activity is proportional to its surface area makes the surface area of Wirtanen about 2.4 km 2, equivalent to an effective radius of ≈0.44 km.

Tsunamis from strike-slip earthquakes in the Wharton Basin, northeast Indian Ocean: March 2016 Mw7.8 event and its relationship with the April 2012 Mw 8.6 event

NASA Astrophysics Data System (ADS)

Heidarzadeh, Mohammad; Harada, Tomoya; Satake, Kenji; Ishibe, Takeo; Takagawa, Tomohiro

2017-12-01

The Wharton Basin, off southwest Sumatra, ruptured to a large intraplate left-lateral strike-slip Mw 7.8 earthquake on 2016 March 2. The epicentre was located ∼800 km to the south of another similar-mechanism intraplate Mw 8.6 earthquake in the same basin on 2012 April 11. Small tsunamis from these strike-slip earthquakes were registered with maximum amplitudes of 0.5-1.5 cm on DARTs and 1-19 cm on tide gauges for the 2016 event, and the respective values of 0.5-6 and 6-40 cm for the 2012 event. By using both teleseismic body waves and tsunami observations of the 2016 event, we obtained optimum slip models with rupture velocity (Vr) in the range of 2.8-3.6 km s-1 belonging to both EW and NS faults. While the EW fault plane cannot be fully ruled out, we chose the best model as the NS fault plane with a Vr of 3.6 km s-1, a maximum slip of 7.7 m and source duration of 33 s. The tsunami energy period bands were 4-15 and 7-24 min for the 2016 and 2012 tsunamis, respectively, reflecting the difference in source sizes. Seismicity in the Wharton Basin is dominated by large strike-slip events including the 2012 (Mw 8.6 and 8.2) and 2016 (Mw 7.8) events, indicating that these events are possible tsunami sources in the Wharton Basin. Cumulative number and cumulative seismic-moment curves revealed that most earthquakes are of strike-slip mechanisms and the largest seismic-moment is provided by the strike-slip earthquakes in this basin.

Abundance analysis of the supergiant stars HD 80057 and HD 80404 based on their UVES Spectra

NASA Astrophysics Data System (ADS)

Tanrıverdi, T.; Baştürk, Ö.

2016-08-01

This study presents elemental abundances of the early A-type supergiant HD 80057 and the late A-type supergiant HD 80404. High resolution and high signal-to-noise ratio spectra published by the UVES Paranal Observatory Project (Bagnulo et al., 2003) were analyzed to compute their elemental abundances using ATLAS9 (Kurucz, 1993; 2005; Sbordone et al., 2004). In our analysis we assumed local thermodynamic equilibrium. The atmospheric parameters of HD 80057 used in this study are from Firnstein and Przybilla (2012), and that of HD 80404 are derived from spectral energy distribution, ionization equilibria of Cr I/II and Fe I/II, the fits to the wings of Balmer and Paschen lines as Teff = 7700 ± 150 K and log g = 1.60 ± 0.15 (in cgs). The microturbulent velocities of HD 80057 and HD 80404 have been determined as 4.3 ± 0.1 and 2.2 ± 0.0 km s^-1, respectively. The rotational velocities are 15 ± 1 and 7 ± 2 km s^-1 and their macroturbulence velocities are 24 ± 2 and 2 ± 1 km s^1. We have given the abundances of 25 ions of 19 elements for HD 80057 and 36 ions of 25 elements for HD 80404. The abundances are close to solar values, except for some elements (Na, Sc, Ti, V, Ba, and Sr). We have found the metallicities [M/H] for HD 80057 and HD 80404 as -0.16 ± 0.24 and -0.04 ± 0.16 dex, respectively. The evolutionary status of these stars are discussed and their nitrogen-to-carbon (N/C) and nitrogen-to-oxygen (N/O) ratios show that they are in their blue supergiant phase before the red supergiant region.

A new approach to geographic partitioning of probabilistic seismic hazard using seismic source distance with earthquake extreme and perceptibility statistics: an application to the southern Balkan region

NASA Astrophysics Data System (ADS)

Bayliss, T. J.

2016-02-01

The southeastern European cities of Sofia and Thessaloniki are explored as example site-specific scenarios by geographically zoning their individual localized seismic sources based on the highest probabilities of magnitude exceedance. This is with the aim of determining the major components contributing to each city's seismic hazard. Discrete contributions from the selected input earthquake catalogue are investigated to determine those areas that dominate each city's prevailing seismic hazard with respect to magnitude and source-to-site distance. This work is based on an earthquake catalogue developed and described in a previously published paper by the author and components of a magnitude probability density function. Binned magnitude and distance classes are defined using a joint magnitude-distance distribution. The prevailing seismicity to each city-as defined by a child data set extracted from the parent earthquake catalogue for each city considered-is divided into distinct constrained data bins of small discrete magnitude and source-to-site distance intervals. These are then used to describe seismic hazard in terms of uni-variate modal values; that is, M* and D* which are the modal magnitude and modal source-to-site distance in each city's local historical seismicity. This work highlights that Sofia's dominating seismic hazard-that is, the modal magnitudes possessing the highest probabilities of occurrence-is located in zones confined to two regions at 60-80 km and 170-180 km from this city, for magnitude intervals of 5.75-6.00 Mw and 6.00-6.25 Mw respectively. Similarly, Thessaloniki appears prone to highest levels of hazard over a wider epicentral distance interval, from 80 to 200 km in the moment magnitude range 6.00-6.25 Mw.

Formation of a paleothermal anomaly and disseminated gold deposits associated with the Bingham Canyon porphyry Cu-Au-Mo system, Utah

USGS Publications Warehouse

Cunningham, C.G.; Austin, G.W.; Naeser, C.W.; Rye, R.O.; Ballantyne, G.H.; Stamm, R.G.; Barker, C.E.

2004-01-01

The thermal history of the Oquirrh Mountains, Utah, indicates that hydrothermal fluids associated with emplacement of the 37 Ma Bingham Canyon porphyry Cu-Au-Mo deposit extended at least 10 km north of the Bingham pit. An associated paleothermal anomaly enclosed the Barneys Canyon and Melco disseminated gold deposits and several smaller gold deposits between them. Previous studies have shown the Barneys Canyon deposit is near the outer limit of an irregular distal Au-As geochemical halo, about 3 km beyond an intermediate Pb-Zn halo, and 7 km beyond a proximal pyrite halo centered on the Bingham porphyry copper deposit. The Melco deposit also lies near the outer limit of the Au-As halo. Analysis of several geothermometers from samples collected tip to 22 km north of the Bingham Canyon porphyry Cu-Au-Mo deposit indicate that most sedimentary rocks of the Oquirrh Mountains, including those at the gold deposits, have not been regionally heated beyond the "oil window" (less than about 150??C). For geologically reasonable heating durations, the maximum sustained temperature at Melco, 6 km north of the Bingham pit, and at Barneys Canyon, 7.5 km north of the pit, was between 100??C and 140??C, as indicated by combinations of conodont color alteration indices of 1.5 to 2, mean random solid bitumen reflectance of about 1.0 percent, lack of annealing of zircon fission tracks, and partial to complete annealing of apatite fission tracks. The pattern of reset apatite fission-track ages indicates that the gold deposits are located approximately on the 120??C isotherm of the 37 Ma paleothermal anomaly assuming a heating duration of about 106 years. The conodont data further constrain the duration of heating to between 5 ?? 104 and 106 years at approximately 120??C. The ??18O of quartzite host rocks generally increases from about 12.6 per mil at the porphyry to about 15.8 per mil approximately 11 km from the Bingham deposit. This change reflects interaction of interstitial clays in the quartzite with circulating meteoric water related to the Bingham Canyon porphyry system. The ??18O and ??13C values of limestone vary with respect to degree of recrystallization and proximity to open fractures. Recrystallized limestone at the Melco and Barneys Canyon gold deposits has the highest ??18O values (about 30???), whereas limestone adjacent to the porphyry copper deposit has the lowest values (about 10???). The high ??18O values for the recrystallized limestone at Barneys Canyon and Melco strongly suggest that mineralization was related to low temperature fluids with exceptionally high ??18OH2O values such as could be derived from water in a crater lake of an active volcano. The age of formation of the gold deposits has been interpreted to range from Jurassic to Eocene. The mineralized rocks at the Barneys Canyon and Melco deposits are likely the same age as the geochemically similar deposits that are present in north-striking, late faults that cut the Bingham Canyon porphyry. The patterns of apatite and zircon fission-track data, conodont color alteration indices, solid bitumen reflectivity, stable isotope data, and mineral zoning are consistent with the gold deposits being genetically related to formation of the 37 Ma Bingham porphyry deposit. We interpret the disseminated gold mineralization to be related to collapse of the Bingham Canyon hydrothermal system in which isotopically heavy, oxidizing, acidic waters, possibly from an internally draining acidic crater lake, mixed with and were entrained into reduced gold-bearing meteoric water fluids in the collapsing main-stage hydrothermal system. Most of this fluid mixing and cooling was probably located close to the hydrologic interface between the sedimentary basement rocks and overlying volcanic rocks. ??2004 by Economic Geology.

Neurospora crassa alpha-ketoglutarate dehydrogenase complex: description, resolution of components and catalytic properties.

PubMed

Bessam, H; Mareck, A M; Foucher, B

1989-01-27

A method is proposed for the purification of the Neurospora crassa alpha-ketoglutarate dehydrogenase complex, and the main points for preserving its activity, which seems to be particularly fragile in fungus, are discussed. Resolution of the constitutive enzymes was attempted and permitted the identification of the three protein bands resolved on SDS-polyacrylamide gel electrophoresis as E3, E1 and E2 with respective Mr values of 54,000, 53,000 and 49,000. Catalytic properties of the purified complex were established showing the importance of divalent cations in regulating the activity level. The role of Ca2+ in particular was investigated. It was shown that Ca2+ diminishes the Km value of the N. crassa alpha-ketoglutarate dehydrogenase complex for alpha-ketoglutarate in the physiological concentration range, as previously observed for the mammalian complexes.

Chandra Discovery of a Tree in the X-Ray Forest toward PKS 2155-304: The Local Filament?

NASA Astrophysics Data System (ADS)

Nicastro, Fabrizio; Zezas, Andreas; Drake, Jeremy; Elvis, Martin; Fiore, Fabrizio; Fruscione, Antonella; Marengo, Massimo; Mathur, Smita; Bianchi, Stefano

2002-07-01

We present the first X-ray detection of resonant absorption from warm/hot local gas either in our Galaxy, or in the intergalactic space surrounding our Galaxy, along the line of sight toward the blazar PKS 2155-304. The Chandra HRCS/LETG spectrum of this z=0.116 source clearly shows, at >=5 σ level, unresolved (FWHM<=800 km s-1 at a 2 σ confidence level) O VII Kα and Ne IX Kα resonant absorption lines at 21.603+0.014-0.024 and 13.448+0.022-0.024 Å (i.e., cz=14+190-330 km s-1 in the rest frame, from the O VII Kα line). O VIII Kα and O VII Kβ from the same system are also detected at a lower significance level (i.e., ~3 σ), while upper limits are set on O VIII Kβ, Ne X Kα, and Ne IX Kβ. The Far Ultraviolet Spectroscopic Explorer spectrum of this source shows complex O VI 2s-->2p absorption at the same redshift as the X-ray system, made by at least two components: one relatively narrow (FWHM=106+/-9 km s-1) and slightly redshifted (cz=36+/-6 km s-1), and one broader (FWHM=158+/-26 km s-1) and blueshifted (cz=-135+/-14 km s-1). We demonstrate that the physical states of the UV and X-ray absorbers are hard to reconcile with a single, purely collisionally ionized, equilibrium plasma. We propose instead that the X-ray and at least the broader and blueshifted UV absorber are produced in a low-density intergalactic plasma, collapsing toward our Galaxy, consistent with the predictions of a warm-hot intergalactic medium from numerical simulations. We find that any reasonable solution requires overabundance of Ne compared to O by a factor of ~2, with respect to the solar value. We propose several scenarios to account for this observation.

An analysis of the errors associated with the determination of atmospheric temperature from atmospheric pressure and density data

NASA Technical Reports Server (NTRS)

Minzner, R. A.

1976-01-01

A graph was developed for relating delta T/T, the relative uncertainty in atmospheric temperature T, to delta p/p, the relative uncertainty in the atmospheric pressure p, for situations, when T is derived from the slope of the pressure-height profile. A similar graph relates delta T/T to delta roh/rho, the relative uncertainty in the atmospheric density rho, for those cases when T is derived from the downward integration of the density-height profile. A comparison of these two graphs shows that for equal uncertainties in the respective basic parameters, p or rho, smaller uncertainties in the derived temperatures are associated with density-height rather than with pressure-height data. The value of delta T/T is seen to depend not only upon delta p or delta rho, and to a small extent upon the value of T or the related scale height H, but also upon the inverse of delta h, the height increment between successive observations of p or rho. In the case of pressure-height data, delta T/T is dominated by 1/delta h for all values of delta h; for density-height data, delta T/T is dominated by delta rho/rho for delta h smaller than about 5 km. In the case of T derived from density-height data, this inverse relationship between delta T/T and delta h applies only for large values of delta h, that is, for delta h 35 km. No limit exists in the fineness of usable height resolution of T which may be derived from densities, while a fine height resolution in pressure-height data leads to temperature with unacceptably large uncertainties.

Intercomparison of aerosol measurements performed with multi-wavelength Raman lidars, automatic lidars and ceilometers in the framework of INTERACT-II campaign

NASA Astrophysics Data System (ADS)

Madonna, Fabio; Rosoldi, Marco; Lolli, Simone; Amato, Francesco; Vande Hey, Joshua; Dhillon, Ranvir; Zheng, Yunhui; Brettle, Mike; Pappalardo, Gelsomina

2018-04-01

Following the previous efforts of INTERACT (INTERcomparison of Aerosol and Cloud Tracking), the INTERACT-II campaign used multi-wavelength Raman lidar measurements to assess the performance of an automatic compact micro-pulse lidar (MiniMPL) and two ceilometers (CL51 and CS135) in providing reliable information about optical and geometric atmospheric aerosol properties. The campaign took place at the CNR-IMAA Atmospheric Observatory (760 m a. s. l. ; 40.60° N, 15.72° E) in the framework of ACTRIS-2 (Aerosol Clouds Trace gases Research InfraStructure) H2020 project. Co-located simultaneous measurements involving a MiniMPL, two ceilometers and two EARLINET multi-wavelength Raman lidars were performed from July to December 2016. The intercomparison highlighted that the MiniMPL range-corrected signals (RCSs) show, on average, a fractional difference with respect to those of CNR-IMAA Atmospheric Observatory (CIAO) lidars ranging from 5 to 15 % below 2.0 km a.s.l. (above sea level), largely due to the use of an inaccurate overlap correction, and smaller than 5 % in the free troposphere. For the CL51, the attenuated backscatter values have an average fractional difference with respect to CIAO lidars < 20-30 % below 3 km and larger above. The variability of the CL51 calibration constant is within ±46 %. For the CS135, the performance is similar to the CL51 below 2.0 km a. s. l. , while in the region above 3 km a. s. l. the differences are about ±40 %. The variability of the CS135 normalization constant is within ±47 %.Finally, additional tests performed during the campaign using the CHM15k ceilometer operated at CIAO showed the clear need to investigate the CHM15k historical dataset (2010-2016) to evaluate potential effects of ceilometer laser fluctuations on calibration stability. The number of laser pulses shows an average variability of 10 % with respect to the nominal power which conforms to the ceilometer specifications. Nevertheless, laser pulses variability follows seasonal behavior with an increase in the number of laser pulses in summer and a decrease in winter. This contributes to explain the dependency of the ceilometer calibration constant on the environmental temperature hypothesized during INTERACT.

Health impact assessment of waste management facilities in three European countries

PubMed Central

2011-01-01

Background Policies on waste disposal in Europe are heterogeneous and rapidly changing, with potential health implications that are largely unknown. We conducted a health impact assessment of landfilling and incineration in three European countries: Italy, Slovakia and England. Methods A total of 49 (Italy), 2 (Slovakia), and 11 (England) incinerators were operating in 2001 while for landfills the figures were 619, 121 and 232, respectively. The study population consisted of residents living within 3 km of an incinerator and 2 km of a landfill. Excess risk estimates from epidemiological studies were used, combined with air pollution dispersion modelling for particulate matter (PM10) and nitrogen dioxide (NO2). For incinerators, we estimated attributable cancer incidence and years of life lost (YoLL), while for landfills we estimated attributable cases of congenital anomalies and low birth weight infants. Results About 1,000,000, 16,000, and 1,200,000 subjects lived close to incinerators in Italy, Slovakia and England, respectively. The additional contribution to NO2 levels within a 3 km radius was 0.23, 0.15, and 0.14 μg/m3, respectively. Lower values were found for PM10. Assuming that the incinerators continue to operate until 2020, we are moderately confident that the annual number of cancer cases due to exposure in 2001-2020 will reach 11, 0, and 7 in 2020 and then decline to 0 in the three countries in 2050. We are moderately confident that by 2050, the attributable impact on the 2001 cohort of residents will be 3,621 (Italy), 37 (Slovakia) and 3,966 (England) YoLL. The total exposed population to landfills was 1,350,000, 329,000, and 1,425,000 subjects, respectively. We are moderately confident that the annual additional cases of congenital anomalies up to 2030 will be approximately 2, 2, and 3 whereas there will be 42, 13, and 59 additional low-birth weight newborns, respectively. Conclusions The current health impacts of landfilling and incineration can be characterized as moderate when compared to other sources of environmental pollution, e.g. traffic or industrial emissions, that have an impact on public health. There are several uncertainties and critical assumptions in the assessment model, but it provides insight into the relative health impact attributable to waste management. PMID:21635784

Relationships between weekly walking distance and adiposity in27,596 women are nonlinear with respect to both distance andadiposity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Paul T.

2004-12-01

The cross-sectional relationships of weekly walking distance to BMI, body circumferences, and bra cup sizes are reported for 27,596 women. The percent reductions between walking 40-50 km/wk and < 10km/wk were greatest for BMI, substantial for waist circumference and cupsize, and least for hip and chest circumferences. The relationships between distance and adiposity were nonlinear with respect to both the independent (quadratic function of distance) and dependent variables(slope and curvilinearity depending upon the percentile of BMI, circumference, or cup size). The slope relating adiposity to km/wk were greatest (most negative) in overweight sedentary women and least in lean active women.more » For example, compared to women averaging 10 km/wk, the slope of BMI versus km/wk was 43 percent less at 25 km/wk and 87 percent less at 40 km/wk in overweight women (95th BMI percentile), but negligible at all distances in lean women (5th BMI percentile). The greater estimated decrease in BMI per km/wk in walkers than runners was largely accounted for (over 75 percent) by the walkers greater adiposity. Thus classical representations of the relationship between adiposity and moderate physical activity are inadequate for either statistical analyses or descriptive purposes. The clinical implications of these results and their statistical ramifications are discussed.« less

The velocity structure of the lunar crust.

NASA Technical Reports Server (NTRS)

Kovach, R. L.; Watkins, J. S.

1973-01-01

Seismic refraction data, obtained at the Apollo 14 and 16 sites, when combined with other lunar seismic data, allow a compressional wave velocity profile of the lunar near-surface and crust to be derived. The regolith, although variable in thickness over the lunar surface, possesses surprisingly similar seismic properties. Underlying the regolith at both the Apollo 14 Fra Mauro site and the Apollo 16 Descartes site is low-velocity brecciated material or impact derived debris. Key features of the lunar seismic velocity profile are: (1) velocity increases from 100 to 300 m/sec in the upper 100 m to about 4 km/sec at 5 km depth, (2) a more gradual increase from about 4 km/sec to about 6 km/sec at 25 km depth,(3) a discontinuity at a depth of 25 km, and (4) a constant value of about 7 km/sec at depths from 25 km to about 60 km.

Establish susceptibility and risk assessment models for rainfall-induced landslide: A case in Central Taiwan

NASA Astrophysics Data System (ADS)

Wu, Chunhung; Huang, Jyuntai

2017-04-01

Most of the landslide cases in Taiwan were triggered by rainfall or earthquake events. The heavy rainfall in the typhoon seasons, from June to October, causes the landslide hazard more serious. Renai Towhship is of the most large landslide cases after 2009 Typhoon Morakot (from Aug. 5 to Aug. 10, 2009) in Taiwan. Around 2,744 landslides cases with the total landslide area of 21.5 km2 (landslide ratio =1.8%), including 26 large landslide cases, induced after 2009 Typhoon Morakot in Renai Towhship. The area of each large landslides case is more than 0.1 km2, and the area of the largest case is around 0.96 km2. 58% of large landslide cases locate in the area with metamorphosed sandstone. The mean slope of 26 large landslide cases ranges from 15 degree to 56 degree, and the accumulated rainfall during 2009 Typhoon Morakot ranges from 530 mm to 937 mm. Three methods, including frequency ratio method (abbreviated as FR), weights of evidence method (abbreviated as WOE), and logistic regression method (abbreviated as LR), are used in this study to establish the landslides susceptibility in the Renai Township, Nantou County, Taiwan. Eight landslide related-factors, including elevation, slope, aspect, geology, land use, distance to drainage, distance to fault, accumulation rainfall during 2009 Typhoon Morakot, are used to establish the landslide susceptibility models in this study. The landslide inventory after 2009 Typhoon Morakot is also used to test the model performance in this study. The mean accumulated rainfall in Renai Township during 2009 typhoon Morakot was around 735 mm with the maximum 1-hr, 3-hrs, and 6-hrs rainfall intensity of 44 mm/1-hr, 106 mm/3-hrs and 204 mm/6-hrs, respectively. The range of original susceptibility values established by three methods are 4.0 to 20.9 for FR, -33.8 to -16.1 for WOE, and -41.7 to 5.7 for LR, and the mean landslide susceptibility value are 8.0, -24.6 and 0.38, respectively. The AUC values are 0.815 for FR, 0.816 for WOE, and 0.823 for LR. The study normalized the susceptibility value range of three landslide susceptibility models to 0 to 1 to deeply compare the model performance. The normalized landslide susceptibility value > 0.5 and ≦0.5 are regarded as predicted-landslide area and predicted-not-landslide area. The ratio of the area in the predicted-landslide area to the total area is 3.0% for FR, 71.4% for WOE, and 26.5% for LR. And the correct ratio is 65.5% for FR, 61.9% for WOE, 74.5% for LR. The study adopted 14 rainfall stations with more than 20 years daily rainfall data in Renai Township to estimate the 24 hrs accumulated rainfall with different RPYs. Landslide susceptibility map under 24 hrs accumulated rainfall distribution with different RPYs is used to estimate the landslide disaster location and scale. The landslide risk under different RPYs in Renai Township is calculated as 2.62 billion for 5 RPYs, 3.06 billion for 10 RPYs, 4.69 billion for 25 RPYs, 5.97 billion for 50 RPYs, 6.98 billion for 100 RPYs, and 8.23 billion for 200 RPYs, respectively.

Bio-oil transport by pipeline: a techno-economic assessment.

PubMed

Pootakham, Thanyakarn; Kumar, Amit

2010-09-01

Bio-oil, produced by fast pyrolysis of biomass, has high energy density compared to 'as received' biomass. The study assesses and compares the cost of transportation ($/liter of bio-oil) of bio-oil by pipeline and truck. The fixed and variable cost components of transportation of bio-oil at a pipeline capacity of 560 m(3)/day and to a distance of 100 km are 0.0423$/m(3) and 0.1201$/m(3)/km, respectively. Pipeline transportation of bio-oil costs less than transportation by liquid tank truck (load capacity 30 m(3)) and super B-train trailer (load capacity 60 m(3)) above pipeline capacities of 1000 and 1700 m(3)/day, respectively. When transportation distance is greater than 100 km, bio-oil must be heated at booster stations. When transporting bio-oil by pipeline to a distance of 400 km, minimum pipeline capacities of 1150 and 2000 m(3)/day are required to compete economically with liquid tank trucks and super B-train tank trailers, respectively. Copyright 2010 Elsevier Ltd. All rights reserved.

The adenosine triphosphate inhibition of the pyruvate kinase reaction and its dependence on the total magnesium ion concentration

PubMed Central

Holmsen, Holm; Storm, Eva

1969-01-01

1. The effects of ATP, PPi and EDTA on the skeletal-muscle pyruvate kinase reaction at various concentrations of magnesium (where `magnesium' refers to total Mg2+, both free and in the form of complexes) were investigated. The reaction rate was determined as the amount of pyruvate formed in a recorded time of incubation. 2. At 44mm-magnesium the Km values for ADP and phosphoenolpyruvate were unaltered by the presence of ATP up to 6·8mm in systems buffered with either tris–hydrochloric acid or glycylglycine–sodium hydroxide, but the Km values were different in these systems. The Km for one substrate was independent of the concentration of the second substrate. 3. At 10mm-magnesium in the tris–hydrochloric acid system ATP inhibited the reaction competitively with respect to ADP and phosphoenolpyruvate. In the glycylglycine–sodium hydroxide system the inhibition appeared to be non-competitive. At 10mm-magnesium the Km values were lower than at 44mm-magnesium and dependent on the system used. 4. In the tris–hydrochloric acid system the reaction rate rose with increasing magnesium concentration up to a maximum at a concentration 10–20 times that of ADP. Further increase inhibited the reaction and at 44mm-magnesium the rate was 25–50% of its maximum. This inhibition paralleled that produced by increasing trimethylammonium chloride concentrations and was not due to a specific effect of the Mg2+ ion. 5. In the presence of 6·8mm-ATP no reaction occurred below 4–6mm-magnesium, and further increase apparently abolished the inhibition as the reaction rate increased and became equal to those obtained in the absence of ATP at 10–25mm-magnesium. Further increase in magnesium concentration gave reaction rates that were slightly higher in the presence of ATP than in its absence. The maximal rate in the presence of ATP was distinctly lower than in its absence. When 6·8mm-PPi or 6·8mm-EDTA was present the variations in reaction rate with rising magnesium concentration were similar to that obtained in the presence of ATP below 6–8mm-magnesium but further increase in the magnesium concentration resulted in an increase in the rate up to a maximum comparable with that of the control. The effect of pure chelation was thus a displacement of the reaction maximum to higher magnesium concentrations without changing the maximal rate. When correction had been made for this effect, ATP gave inhibition at 44mm-magnesium that was competitive with respect to ADP (Ki 2·1×10−2m). This degree of inhibition is far less than was reported earlier and its importance for the mechanism of the pyruvate kinase reaction is discussed. PMID:4308294

Classification of X-ray solar flares regarding their effects on the lower ionosphere electron density profile

NASA Astrophysics Data System (ADS)

Grubor, D. P.; Ulić, D. M. Å.; Žigman, V.

2008-06-01

The classification of X-ray solar flares is performed regarding their effects on the Very Low Frequency (VLF) wave propagation along the Earth-ionosphere waveguide. The changes in propagation are detected from an observed VLF signal phase and amplitude perturbations, taking place during X-ray solar flares. All flare effects chosen for the analysis are recorded by the Absolute Phase and Amplitude Logger (AbsPal), during the summer months of 2004-2007, on the single trace, Skelton (54.72 N, 2.88 W) to Belgrade (44.85 N, 20.38 E) with a distance along the Great Circle Path (GCP) D≍2000 km in length. The observed VLF amplitude and phase perturbations are simulated by the computer program Long-Wavelength Propagation Capability (LWPC), using Wait's model of the lower ionosphere, as determined by two parameters: the sharpness (β in 1/km) and reflection height (H' in km). By varying the values of β and H' so as to match the observed amplitude and phase perturbations, the variation of the D-region electron density height profile Ne(z) was reconstructed, throughout flare duration. The procedure is illustrated as applied to a series of flares, from class C to M5 (5×10-5 W/m2 at 0.1-0.8 nm), each giving rise to a different time development of signal perturbation. The corresponding change in electron density from the unperturbed value at the unperturbed reflection height, i.e. Ne(74 km)=2.16×108 m-3 to the value induced by an M5 class flare, up to Ne(74 km)=4×1010 m-3 is obtained. The β parameter is found to range from 0.30-0.49 1/km and the reflection height H' to vary from 74-63 km. The changes in Ne(z) during the flares, within height range z=60 to 90 km are determined, as well.

The added value of stochastic spatial disaggregation for short-term rainfall forecasts currently available in Canada

NASA Astrophysics Data System (ADS)

Gagnon, Patrick; Rousseau, Alain N.; Charron, Dominique; Fortin, Vincent; Audet, René

2017-11-01

Several businesses and industries rely on rainfall forecasts to support their day-to-day operations. To deal with the uncertainty associated with rainfall forecast, some meteorological organisations have developed products, such as ensemble forecasts. However, due to the intensive computational requirements of ensemble forecasts, the spatial resolution remains coarse. For example, Environment and Climate Change Canada's (ECCC) Global Ensemble Prediction System (GEPS) data is freely available on a 1-degree grid (about 100 km), while those of the so-called High Resolution Deterministic Prediction System (HRDPS) are available on a 2.5-km grid (about 40 times finer). Potential users are then left with the option of using either a high-resolution rainfall forecast without uncertainty estimation and/or an ensemble with a spectrum of plausible rainfall values, but at a coarser spatial scale. The objective of this study was to evaluate the added value of coupling the Gibbs Sampling Disaggregation Model (GSDM) with ECCC products to provide accurate, precise and consistent rainfall estimates at a fine spatial resolution (10-km) within a forecast framework (6-h). For 30, 6-h, rainfall events occurring within a 40,000-km2 area (Québec, Canada), results show that, using 100-km aggregated reference rainfall depths as input, statistics of the rainfall fields generated by GSDM were close to those of the 10-km reference field. However, in forecast mode, GSDM outcomes inherit of the ECCC forecast biases, resulting in a poor performance when GEPS data were used as input, mainly due to the inherent rainfall depth distribution of the latter product. Better performance was achieved when the Regional Deterministic Prediction System (RDPS), available on a 10-km grid and aggregated at 100-km, was used as input to GSDM. Nevertheless, most of the analyzed ensemble forecasts were weakly consistent. Some areas of improvement are identified herein.

Spectroscopic analyses of the parent stars of extrasolar planetary system candidates

NASA Astrophysics Data System (ADS)

Gonzalez, Guillermo

1998-06-01

The stars rho () 1 Cnc, rho CrB, 16 Cyg B, 51 Peg, 47 UMa, 70 Vir, and HD 114762 have recently been proposed to harbor planetary mass companions based on small amplitude radial velocity variations. From spectroscopic analyses we derive the following values of [Fe/H] for these stars: 0.29, -0.29, 0.06, 0.21, 0.01, -0.03, and -0.60 (all with an uncertainty of 0.06 dex), respectively; the [Fe/H] value for 16 Cyg A is 0.11. The four 51 Peg-like systems, upsilon And, tau Boo, rho () 1 Cnc, and 51 Peg, have a mean [Fe/H] value of 0.25. Otherwise, the abundance patterns, expressed as [X/Fe], are approximately solar. We used Fourier analysis, supplemented by line profile synthesis, to derive the following v sin i values: <1.3, 1.4 +/- 0.3, 1.7 +/- 0.4, < 0.5, and < 1.5 km s(-1) for rho () 1 Cnc, 51 Peg, 47 UMa, 70 Vir, and HD 114762, respectively. A similar analysis of the spectrum of rho CrB (with a lower resolving power) yields a value of ~ 1.5 km s() -1. Combining these data with published estimates of v sin i and rotation periods and assuming that the radial velocity variations are due to the presence of planets, we derive the following masses for the companions: >0.66, 2.9(+13.6}_{-1.3) , 0.49+/-0.03, 3.4() +3.1_-1.1, >9.4, and >10.4 cal M_J for rho () 1 Cnc, rho CrB, 51 Peg, 47 UMa, 70 Vir, and HD 114762, respectively; the mass of 16 Cyg B b, calculated using a published estimate for sin i, is 2.0() +1.1_-0.3 cal M_J. The masses of the companions to upsilon And and tau Boo, which were analyzed in a previous paper, are 0.76() +0.19_-0.03 and 5.9() +43.9_-1.8 cal M_J, respectively. We confirm previous claims that rho () 1 Cnc appears to be a subgiant. However, the theoretical isochrone-derived age is much greater than the age of the universe. At this time we have insufficient data to determine the true nature of rho () 1 Cnc, but we suggest that it may be an unresolved stellar binary viewed nearly pole-on. A search for line profile variations might help to resolve this mystery. Our findings are consistent with a recently proposed mechanism whereby a gas giant migrates to within a few hundredths of an AU of its parent star during the formative epoch of the planetary system, and the material between the planet and the star is accreted onto the latter. If the accreted material is depleted in H and He, then the photospheric composition of the parent star might be altered significantly.

Floating plastic debris in the Central and Western Mediterranean Sea.

PubMed

Ruiz-Orejón, Luis F; Sardá, Rafael; Ramis-Pujol, Juan

2016-09-01

In two sea voyages throughout the Mediterranean (2011 and 2013) that repeated the historical travels of Archduke Ludwig Salvator of Austria (1847-1915), 71 samples of floating plastic debris were obtained with a Manta trawl. Floating plastic was observed in all the sampled sites, with an average weight concentration of 579.3 g dw km(-2) (maximum value of 9298.2 g dw km(-2)) and an average particle concentration of 147,500 items km(-2) (the maximum concentration was 1,164,403 items km(-2)). The plastic size distribution showed microplastics (<5 mm) in all the samples. The most abundant particles had a surface area of approximately 1 mm(2) (the mesh size was 333 μm). The general estimate obtained was a total value of 1455 tons dw of floating plastic in the entire Mediterranean region, with various potential spatial accumulation areas. Copyright © 2016 Elsevier Ltd. All rights reserved.

Upper mantle electrical conductivity for seven subcontinental regions of the Earth

USGS Publications Warehouse

Campbell, W.H.; Schiffmacher, E.R.

1988-01-01

Spherical harmonic analysis coefficients of the external and internal parts of the quiet-day geomagnetic field variations (Sq) separated for the 7 continental regions of the observatories have been used to determine conductivity profiles to depths of about 600 km by the Schmucker equivalent substitute conductor method. The profiles give evidence of increases in conductivity between about 150 and 350 km depth, then a general increase in conductivity thereafter. For South America we found a high conductivity at shallow depths. The European profile showed a highly conducting layer near 125 km. At the greater depths, Europe, Australia and South America had the lowest values of conductivity. North America and east Asia had intermediate values whereas the African and central Asian profiles both showed the conductivities rising rapidly beyond 450 km depth. The regional differences indicate that there may be considerable lateral heterogeneity of electrical conductivity in the Earth's upper mantle. -Authors

U.S. Standard Atmosphere, 1976

NASA Technical Reports Server (NTRS)

1976-01-01

Part 1 gives the basis for computation of the main tables of atmospheric properties, including values of physical constants, conversion factors, and definitions of derived properties, including values of physical constants, conversion factors, and definitions of derived properties. Part 2 describes the model and data used up to 85 km, in the first section; and the model and data used above 85 km in the second section. The theoretical basis of the high altitude model is given in an appendix. Part 3 contains information on minor constituents in the troposphere, stratosphere, and mesosphere. The main tables of atmospheric properties to 1000 km are given in Part 4. The international system of metric units is used.

An informative solution to a seismological inverse problem.

PubMed

Gilbert, F; Dziewonski, A; Brune, J

1973-05-01

Preliminary results are presented that infer that 2 sec should be added to the tabular values for P phases and 4 sec to the tabular values for S phases of seismic travel times. From seismic evidence, the radius of the inner core of the Earth is 1229-1250 km; the radius of the outer core is 3482-3485 km. Data are presented relating resolving power with error of measurement for the Earth's mantle.

Mapping Global Urban Dynamics from Nighttime Lights - 1992 to 2012

NASA Astrophysics Data System (ADS)

Xie, Yanhua

Accurate, up-to-date, and consistent information of urban extent is indispensable for numerous applications central to urban planning, ecosystem management, and environmental assessment and monitoring. However, current large-scale urban extent products are not uniform with respect to urban definition, spatial resolution, thematic representation, and temporal frequency. To fill this gap, this study proposed a method to update and backdate global urban extent from currently available urban maps by using nighttime light (NTL) as the main indicator. The method followed three steps: (1) exploring the spatiotemporal variation of NTL thresholds for mapping urban dynamics from NTL time series and developing an object-based thresholding method (i.e., NTL-OUT method, Xie & Weng, 2016b); (2) spatiotemporally enhancing time-series Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) NTL data for detecting broad-scale urban changes (Xie & Weng, 2017); and (3) detecting global urban dynamics during the period between 1992 and 2012 (i.e., 1992, 1997, 2002, 2007, and 2012) from enhanced OLS NTL time series by using the NTL-OUT method. The results show that global urban extent almost doubled during the period from 1992 to 2012, increasing from 0.52 million to 0.98 million km 2, which accounts for 0.39% and 0.72% of the total global land area, respectively. Regionally, the urbanization level varies by continent, with Europe being the most urbanized, followed by North America, Asia, South America, Africa, and Australia-Oceania. In 1992, the urban extent varied from only 0.1% of total continental land area in Australia-Oceania and Africa to 1.18% in Europe. While the proportion of urban extent in North America increased slightly from 1992 to 2002 (i.e., 0.07%), urban extent increased 0.1% for both Asia and South America. In 2012, over 0.7% of the total land was covered by the human built environment, with 0.2% in Africa and Australia-Oceania and around 0.9% in North America, followed by Asia at 0.84% and South America at 0.73%. The exception is the European urban extent, which was 1.82% of its total land mass. Asia has experienced the most rapid urbanization during the period, converting more than 9,000 km2 non-urban land covers/uses to urbanized land each year. Over 3,000 km2 of urban extent has been added annually to European and North American regions, respectively, followed by South America with over 3,000 km2, Africa with 1,700 km 2, and Australia-Oceania with 300 km2. In addition, the results demonstrate that most regions experienced a more rapid urbanization after the 21st century than the period from 1992 to 2002, especially for Asia and Africa. Accuracy assessment in the contiguous U.S.A. (CONUS) and China showed that the proposed method can update and backdate urban extent with reasonably high accuracy, yielding the mean city-scale RMSE (root mean square error) and Kappa: 27 and 23 km2 and 0.65 and 0.63 for CONUS, and 55 and 60 km2 and 0.59 and 0.60 for China, respectively. It was also revealed that spatial enhancement greatly improved the accuracy of urban updating and backdating by significantly decreasing RMSE and slightly increasing Kappa values; temporal enhancement further reduced RMSE and improved the spatial consistency between estimated and reference urban extent. The study generated time-series comparable urban extent maps from 1992 to 2012 with a 5-year interval, which can be used to explore global urbanization and address its impacts on urbanization-induced social and environmental problems.

Antioxidant and Inhibitory Effects of Saponin Extracts from Dianthus basuticus Burtt Davy on Key Enzymes Implicated in Type 2 Diabetes In vitro.

PubMed

Nafiu, Mikhail Olugbemiro; Ashafa, Anofi Omotayo Tom

2017-01-01

Dianthus basuticus is a plant of South African origin with various acclaimed pharmaceutical potentials. This study explored the antioxidant and antidiabetic activities of saponin extract from D. basuticus in vitro . Antioxidant activity of saponin was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (*NO)-free radical scavenging activity while antidiabetic potentials were measured by the α-amylase and α-glucosidase inhibitory activities of the saponin extract. The results showed that the saponin extract, compared with quercetin, displayed better DPPH (IC 50 = 6.95 mg/ml) and NO (IC 50 = 3.31 mg/ml) radical scavenging capabilities. Similarly, the saponin extracts elicited stronger α-glucosidase (IC 50 = 3.80 mg/ml) and moderate α-amylase (IC 50 = 4.18 mg/ml) inhibitory activities as compared to acarbose. Saponin exhibited a competitive mode of inhibition on α-amylase with same maximum velocity (Vmax) of 0.0093 mM/min for saponin compared with control 0.0095 mM/min and different the Michaelis constant (Km) values of 2.6 × 10 -6 mM and 2.1 × 10 -5 mM, respectively, while for α-glucosidase, the inhibition was uncompetitive, Vmax of 0.027 mM/min compared with control 0.039 mM/min and Km values of 1.02 × 10 -6 mM and 1.38 × 10 -6 mM, respectively. The gas chromatography-mass spectrometric analysis revealed the presence of bioactive like β- and α-amyrin, 3-O-methyl-D-glucose, methyl commate, and olean-12-en-3-beta-ol. Overall, the data suggested that the saponin extract from D. basuticus has potentials as natural antioxidants and antidiabetics. Saponin extract from Dianthus basuticus displayed promising antidiabetic and antioxidant activitySaponin competitively and uncompetitively inhibited a-amylase and a-glucosidase, respectivelyThe stronger inhibition of α-glucosidase and moderate inhibition of α-amylase by saponin extract from D. basuticus is promising good antidiabetes compared with existing drugs with associated side effects. Abbreviations used: DPPH: 2,2-diphenyl-1-picrylhydrazyl, Km: The Michaelis constant, Vmax: Maximum velocity, ROS: Reactive oxygen species, NIDDM: Non-insulin-dependent diabetes mellitus, UFS: University of the Free State, GC-MS: Gas chromatography-mass spectrometric, MS: Mass spectrometry, NIST: National Institute of Standards and Technology, DNS: 3,5-dinitrosalicylic acid, NO: Nitric oxide, RNS: Reactive nitrogen species, PNPG: p-Nitrophenyl-α-D-glucopyranoside.

Antioxidant and Inhibitory Effects of Saponin Extracts from Dianthus basuticus Burtt Davy on Key Enzymes Implicated in Type 2 Diabetes In vitro

PubMed Central

Nafiu, Mikhail Olugbemiro; Ashafa, Anofi Omotayo Tom

2017-01-01

Context: Dianthus basuticus is a plant of South African origin with various acclaimed pharmaceutical potentials. Aims: This study explored the antioxidant and antidiabetic activities of saponin extract from D. basuticus in vitro. Materials and Methods: Antioxidant activity of saponin was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (*NO)-free radical scavenging activity while antidiabetic potentials were measured by the α-amylase and α-glucosidase inhibitory activities of the saponin extract. Results: The results showed that the saponin extract, compared with quercetin, displayed better DPPH (IC50 = 6.95 mg/ml) and NO (IC50 = 3.31 mg/ml) radical scavenging capabilities. Similarly, the saponin extracts elicited stronger α-glucosidase (IC50 = 3.80 mg/ml) and moderate α-amylase (IC50 = 4.18 mg/ml) inhibitory activities as compared to acarbose. Saponin exhibited a competitive mode of inhibition on α-amylase with same maximum velocity (Vmax) of 0.0093 mM/min for saponin compared with control 0.0095 mM/min and different the Michaelis constant (Km) values of 2.6 × 10-6 mM and 2.1 × 10-5 mM, respectively, while for α-glucosidase, the inhibition was uncompetitive, Vmax of 0.027 mM/min compared with control 0.039 mM/min and Km values of 1.02 × 10-6 mM and 1.38 × 10-6 mM, respectively. The gas chromatography-mass spectrometric analysis revealed the presence of bioactive like β- and α-amyrin, 3-O-methyl-D-glucose, methyl commate, and olean-12-en-3-beta-ol. Conclusion: Overall, the data suggested that the saponin extract from D. basuticus has potentials as natural antioxidants and antidiabetics. SUMMARY Saponin extract from Dianthus basuticus displayed promising antidiabetic and antioxidant activitySaponin competitively and uncompetitively inhibited a-amylase and a-glucosidase, respectivelyThe stronger inhibition of α-glucosidase and moderate inhibition of α-amylase by saponin extract from D. basuticus is promising good antidiabetes compared with existing drugs with associated side effects. Abbreviations used: DPPH: 2,2-diphenyl-1-picrylhydrazyl, Km: The Michaelis constant, Vmax: Maximum velocity, ROS: Reactive oxygen species, NIDDM: Non-insulin-dependent diabetes mellitus, UFS: University of the Free State, GC-MS: Gas chromatography-mass spectrometric, MS: Mass spectrometry, NIST: National Institute of Standards and Technology, DNS: 3,5-dinitrosalicylic acid, NO: Nitric oxide, RNS: Reactive nitrogen species, PNPG: p-Nitrophenyl-α-D-glucopyranoside. PMID:29200716

A Climatology of Midlatitude Continental Clouds from the ARM SGP Central Facility. Part II; Cloud Fraction and Radiative Forcing

NASA Technical Reports Server (NTRS)

Dong, Xiquan; Xi, Baike; Minnis, Patrick

2006-01-01

Data collected at the Department of Energy Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) central facility are analyzed for determining the variability of cloud fraction and radiative forcing at several temporal scales between January 1997 and December 2002. Cloud fractions are estimated for total cloud cover and for single-layer low (0-3 km), middle (3-6 km), and high clouds (greater than 6 km) using ARM SGP ground-based paired lidar-radar measurements. Shortwave (SW), longwave (LW), and net cloud radiative forcings (CRF) are derived from up- and down-looking standard precision spectral pyranometers and precision infrared radiometer measurements. The annual averages of total, and single-layer, nonoverlapped low, middle and high cloud fractions are 0.49, 0.11, 0.03, and 0.17, respectively. Total and low cloud amounts were greatest from December through March and least during July and August. The monthly variation of high cloud amount is relatively small with a broad maximum from May to August. During winter, total cloud cover varies diurnally with a small amplitude, mid-morning maximum and early evening minimum, and during summer it changes by more than 0.14 over the daily cycle with a pronounced early evening minimum. The diurnal variations of mean single-layer cloud cover change with season and cloud height. Annual averages of all-sky, total, and single-layer high, middle, and low LW CRFs are 21.4, 40.2, 16.7, 27.2, and 55.0 Wm(sup -2), respectively; and their SW CRFs are -41.5, -77.2, -37.0, -47.0, and -90.5 Wm(sup -2). Their net CRFs range from -20 to -37 Wm(sup -2). For all-sky, total, and low clouds, the maximum negative net CRFs of -40.1, -70, and -69.5 Wm(sup -2), occur during April; while the respective minimum values of -3.9, -5.7, and -4.6 Wm(sup -2), are found during December. July is the month having maximum negative net CRF of -46.2 Wm(sup -2) for middle clouds, and May has the maximum value of -45.9 Wm(sup -2) for high clouds. An uncertainty analysis demonstrates that the calculated CRFs are not significantly affected by the difference between clear-sky and cloudy conditions. A more comprehensive cloud fraction study from both surface and satellite observations will follow.

Purification, gene cloning, and characterization of γ-butyrobetainyl CoA synthetase from Agrobacterium sp. 525a.

PubMed

Fujimitsu, Hiroshi; Matsumoto, Akira; Takubo, Sayaka; Fukui, Akiko; Okada, Kazuma; Mohamed Ahmed, Isam A; Arima, Jiro; Mori, Nobuhiro

2016-08-01

The report is the first of purification, overproduction, and characterization of a unique γ-butyrobetainyl CoA synthetase from soil-isolated Agrobacterium sp. 525a. The primary structure of the enzyme shares 70-95% identity with those of ATP-dependent microbial acyl-CoA synthetases of the Rhizobiaceae family. As distinctive characteristics of the enzyme of this study, ADP was released in the catalytic reaction process, whereas many acyl CoA synthetases are annotated as an AMP-forming enzyme. The apparent Km values for γ-butyrobetaine, CoA, and ATP were, respectively, 0.69, 0.02, and 0.24 mM.

Purification and characterization of a hygromycin B phosphotransferase from Streptomyces hygroscopicus.

PubMed

Zalacain, M; Pardo, J M; Jiménez, A

1987-01-15

A hygromycin B phosphotransferase activity from Streptomyces hygroscopicus has been highly purified by ammonium sulphate fractionation followed by affinity column chromatography through Sepharose-6B-hygromycin-B. The combined active fractions showed a single protein band (41 kDa) when subjected to polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. When gel electrophoresis was performed under non-denaturing conditions, the single protein band promoted in situ phosphorylation of hygromycin B, indicating that this protein corresponded to the purified hygromycin B phosphotransferase. The enzyme has been purified 236-fold and approximate Km values of 0.56 microM for hygromycin B and ATP, respectively, were deduced.

Chalcone dimethylallyltransferase from Morus nigra cell cultures. Substrate specificity studies.

PubMed

Vitali, Alberto; Giardina, Bruno; Delle Monache, Giuliano; Rocca, Filippo; Silvestrini, Andrea; Tafi, Andrea; Botta, Bruno

2004-01-16

A new prenyltransferase (PT) enzyme derived from the microsomal fractions of cell cultures of Morus nigra was shown to be able to prenylate exclusively chalcones with a 2',4'-dihydroxy substitution and the isoflavone genistein. Computational studies were performed to shed some light on the relationship between the structure of the substrate and the enzymatic activity. PT requires divalent cations, particularly Mg(2+), to be effective. The apparent K(m) values for gamma,gamma-dimethylallyldiphosphate and 2',4'-dihydroxychalcone were 63 and 142 microM, respectively. The maximum activity of the enzyme was expressed during the first 10 days of cell growth.

Intensity of emission lines of the quiescent solar corona: comparison between calculated and observed values

NASA Astrophysics Data System (ADS)

Krissinel, Boris

2018-03-01

The paper reports the results of calculations of the center-to-limb intensity of optically thin line emission in EUV and FUV wavelength ranges. The calculations employ a multicomponent model for the quiescent solar corona. The model includes a collection of loops of various sizes, spicules, and free (inter-loop) matter. Theoretical intensity values are found from probabilities of encountering parts of loops in the line of sight with respect to the probability of absence of other coronal components. The model uses 12 loops with sizes from 3200 to 210000 km with different values of rarefaction index and pressure at the loop base and apex. The temperature at loop apices is 1 400 000 K. The calculations utilize the CHIANTI database. The comparison between theoretical and observed emission intensity values for coronal and transition region lines obtained by the SUMER, CDS, and EIS telescopes shows quite satisfactory agreement between them, particularly for the solar disk center. For the data acquired above the limb, the enhanced discrepancies after the analysis refer to errors in EIS measurements.

Variability of Atmospheric CO2 over the western North Pacific: Influence of Asian outflow during March-April 2001

NASA Astrophysics Data System (ADS)

Vay, S. A.; Woo, J.; Anderson, B. E.; Thornhill, K. L.; Kiley, C.; Avery, M. A.; Sachse, G. W.; Blake, D. R.; Streets, D. G.; Nolf, S. R.

2002-12-01

We report here tropospheric CO2 measurements made as part of the airborne component of NASA's Transport and Chemical Evolution over the Pacific (TRACE-P) Mission during March and April in 2001. CO2 mixing ratios, sampled in the subtropics (23.5-45.5° N) west of 150° E, exhibited a decreasing trend with height (0.5-12 km), were highly correlated with latitude showing a distinct north to south gradient, and peaked between 35-40° N within the planetary boundary layer. Near the Asian continent, discrete plumes encountered below 4 km contained up to 393.6 ppmv CO2 and were augmented with the combustion and industrial tracers CO, C2H6, C3H8, CH3Cl, C2Cl4, and C6H6. A chemically based air mass classification scheme using the combustion products CO and C2H2 as tracers of continental source emissions was employed in this analysis. Results show an excellent positive correlation for CO2 (r2=0.98) with respect to this ratio in the lower to mid free troposphere (4-8 km) providing evidence of continental outflow. South of the Tropic of Cancer, mean and median CO2 values derived from samples obtained below 8 km are less than those calculated for the subtropics. However, within the upper troposphere (UT) of both regions, similar values were determined and enhancements in combustion-derived species in the 8-12 km altitude range were observed. The relationship revealed between CO2 and the C2H2/CO ratio, particularly for the tropics, suggests recent inputs from the surface to the UT. In order to elucidate the processes determining the variations of CO2 in the Asian Pacific rim region during TRACE-P, a CO2 emissions data base developed for Asia was examined in conjunction with the chemistry and 5 day backward trajectories in an attempt to link CO2 enhancements observed in pollution plumes to source regions. From these data acquired downwind of the Asian continent when CO2 concentrations at the surface were approaching their seasonal maximum, we estimate a net export flux on the order of 20 Tg C day-1 attributable to both anthropogenic emissions and the respiration of the terrestrial biosphere, animals, and humans.

An algorithm for the estimation of bounds on the emissivity and temperatures from thermal multispectral airborne remotely sensed data

NASA Technical Reports Server (NTRS)

Jaggi, S.; Quattrochi, D.; Baskin, R.

1992-01-01

The effective flux incident upon the detectors of a thermal sensor, after it has been corrected for atmospheric effects, is a function of a non-linear combination of the emissivity of the target for that channel and the temperature of the target. The sensor system cannot separate the contribution from the emissivity and the temperature that constitute the flux value. A method that estimates the bounds on these temperatures and emissivities from thermal data is described. This method is then tested with remotely sensed data obtained from NASA's Thermal Infrared Multispectral Scanner (TIMS) - a 6 channel thermal sensor. Since this is an under-determined set of equations i.e. there are 7 unknowns (6 emissivities and 1 temperature) and 6 equations (corresponding to the 6 channel fluxes), there exist theoretically an infinite combination of values of emissivities and temperature that can satisfy these equations. Using some realistic bounds on the emissivities, bounds on the temperature are calculated. These bounds on the temperature are refined to estimate a tighter bound on the emissivity of the source. An error analysis is also carried out to quantitatively determine the extent of uncertainty introduced in the estimate of these parameters. This method is useful only when a realistic set of bounds can be obtained for the emissivities of the data. In the case of water the lower and upper bounds were set at 0.97 and 1.00 respectively. Five flights were flown in succession at altitudes of 2 km (low), 6 km (mid), 12 km (high), and then back again at 6 km and 2 km. The area selected with the Ross Barnett reservoir near Jackson, Mississippi. The mission was flown during the predawn hours of 1 Feb. 1992. Radiosonde data was collected for that duration to profile the characteristics of the atmosphere. Ground truth temperatures using thermometers and radiometers were also obtained over an area of the reservoir. The results of two independent runs of the radiometer data averaged 7.03 plus or minus .70 for the first run and 7.31 plus or minus .88 for the second run. The results of the algorithm yield a temperature of 7.68 for the low altitude data to 8.73 for the high altitude data.

42 CFR 84.104 - Gas tightness test; minimum requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 1 1 Walks at 4.8 km. (3 miles) per hour 2 8 10 Pulls 20 kg. (45 pound) weight to 5 feet 30 times in... times respectively. Walks at 4.8 km. (3 miles) per hour 3 5 3 4 8 12 18 Sampling and readings 2 2 2 2 2 Walks at 4.8 km. (3 miles) per hour 3 5 8 12 18 Sampling and readings 2 2 2 2 2 Walks at 4.8 km. (3...

42 CFR 84.104 - Gas tightness test; minimum requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 1 1 Walks at 4.8 km. (3 miles) per hour 2 8 10 Pulls 20 kg. (45 pound) weight to 5 feet 30 times in... times respectively. Walks at 4.8 km. (3 miles) per hour 3 5 3 4 8 12 18 Sampling and readings 2 2 2 2 2 Walks at 4.8 km. (3 miles) per hour 3 5 8 12 18 Sampling and readings 2 2 2 2 2 Walks at 4.8 km. (3...

42 CFR 84.104 - Gas tightness test; minimum requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 1 1 Walks at 4.8 km. (3 miles) per hour 2 8 10 Pulls 20 kg. (45 pound) weight to 5 feet 30 times in... times respectively. Walks at 4.8 km. (3 miles) per hour 3 5 3 4 8 12 18 Sampling and readings 2 2 2 2 2 Walks at 4.8 km. (3 miles) per hour 3 5 8 12 18 Sampling and readings 2 2 2 2 2 Walks at 4.8 km. (3...

Water miscible mono alcohols' effect on the proteolytic performance of Bacillus clausii serine alkaline protease.

PubMed

Duman, Yonca Avci; Kazan, Dilek; Denizci, Aziz Akin; Erarslan, Altan

2014-01-01

In this study, our investigations showed that the increasing concentrations of all examined mono alcohols caused a decrease in the Vm, kcat and kcat/Km values of Bacillus clausii GMBE 42 serine alkaline protease for casein hydrolysis. However, the Km value of the enzyme remained almost the same, which was an indicator of non-competitive inhibition. Whereas inhibition by methanol was partial non-competitive, inhibition by the rest of the alcohols tested was simple non-competitive. The inhibition constants (KI) were in the range of 1.32-3.10 M, and the order of the inhibitory effect was 1-propanol>2-propanol>methanol>ethanol. The ΔG(≠) and ΔG(≠)E-T values of the enzyme increased at increasing concentrations of all alcohols examined, but the ΔG(≠)ES value of the enzyme remained almost the same. The constant Km and ΔG(≠)ES values in the presence and absence of mono alcohols indicated the existence of different binding sites for mono alcohols and casein on enzyme the molecule. The kcat of the enzyme decreased linearly by increasing log P and decreasing dielectric constant (D) values, but the ΔG(≠) and ΔG(≠)E-T values of the enzyme increased by increasing log P and decreasing D values of the reaction medium containing mono alcohols.

Travel Time Tomographic Imaging of Shallow Fore-arc Basin Structure at the Cascadia Subduction Zone Offshore Washington and Oregon

NASA Astrophysics Data System (ADS)

Azarm, R.; Carton, H. D.; Carbotte, S. M.; Han, S.; Canales, J. P.; Nedimovic, M. R.

2016-12-01

We conduct a P-wave tomography study of shallow fore-arc basin structure at the Cascadia subduction zone using first-arrival travel times from two multi-channel seismic (MCS) profiles acquired with an 8-km long streamer in the frame of the 2012 Juan de Fuca Ridge to Trench program. The first profile extends offshore Gray's Harbor in Washington and the second extends offshore Oregon at the latitude of Hydrate ridge, with the fore-arc basin imaged below ˜60 and ˜70-km long shallow water (< 500 m) portions of these profiles, respectively. We use the travel time tomography method of VanAvendonk et al. [2004], which is based on the shortest path method for ray tracing, and iterative inversions driven by gradual reduction of the chi-square misfit (root mean square value of the difference between predicted and observed travel times normalized by pick uncertainty). We construct our starting model by hanging from the seafloor a 1D velocity profile based on interval velocities derived from semblance analysis of MCS data. Resolvability of the final model is assessed using checkerboard pattern tests with different anomaly sizes. We then compare our tomographically-derived velocity models to coincident seismic reflection images post-stack time migrated and converted to depth using our results. On the Washington shelf, where the fore-arc basin is segmented into three sub-basins, ray coverage mostly extends to ˜1.2-1.5 km below seafloor. Velocities in the shallowmost sediments show, at the large scale, a gradual decrease towards the shelf edge (from 2.1 to 1.8 km/s). At depth, regions devoid of clear reflections such as an ˜5 km large anticline core are associated with lower velocities than that obtained within mildly deformed sedimentary layers on either side (2.3 vs 2.7 km/s, measured at 1.2 km depth), suggesting the presence of localized fluid-rich regions within the basin. Analysis of the Oregon line is ongoing and results will be presented at the meeting.

Corneal Anterior Power Calculation for an IOL in Post-PRK Patients.

PubMed

De Bernardo, Maddalena; Iaccarino, Stefania; Cennamo, Michela; Caliendo, Luisa; Rosa, Nicola

2015-02-01

After corneal refractive surgery, there is an overestimation of the corneal power with the devices routinely used to measure it. Therefore, the objective of this study was to determine whether, in patients who underwent photorefractive keratectomy (PRK), it is possible to predict the earlier preoperative anterior corneal power from the postoperative (PO) posterior corneal power. A comparison is made using a formula published by Saiki for laser in situ keratomileusis patients and a new one calculated specifically from PRK patients. The Saiki formula was tested in 98 eyes of 98 patients (47 women) who underwent PRK for myopia or myopic astigmatism. Moreover, anterior and posterior mean keratometry (Km) values from a Scheimpflug camera were measured to obtain a specific regression formula. The mean (±SD) preoperative Km was 43.50 (±1.39) diopters (D) (range, 39.25 to 47.05 D). The mean (±SD) Km value calculated with the Saiki formula using the 6 months PO posterior Km was 42.94 (±1.19) D (range, 40.34 to 45.98 D) with a statistically significant difference (p < 0.001). Six months after PRK in our patients, the posterior Km was correlated with the anterior preoperative one by the following regression formula: y = -4.9707x + 12.457 (R² = 0.7656), where x is PO posterior Km and y is preoperative anterior Km, similar to the one calculated by Saiki. Care should be taken in using the Saiki formula to calculate the preoperative Km in patients who underwent PRK.

A comparison of pipeline versus truck transport of bio-oil.

PubMed

Pootakham, Thanyakarn; Kumar, Amit

2010-01-01

Biomass-based energy and fuels are receiving attention because they are considered carbon neutral; i.e. the amount of CO(2) released during combustion of this biomass is nearly the same as that taken up by the plants during their growth. Bio-oil is a dark viscous liquid consisting of hydrocarbons. These are produced by fast pyrolysis of biomass. "As-is" biomass material has a low energy density (MJ m(-3)), hence, the cost of transporting this energy is high. Bio-oil has a high energy density as compared to "as-is" biomass material, consequently it helps in reducing the cost of energy transport. This study compares the life cycle assessment of transportation of bio-oil by pipeline with that by truck. The scope of the work includes the transportation of bio-oil by truck or pipeline from a centralized plant (supplied with forest biomass) to an end-user. Two cases are studied for pipeline transport of bio-oil: the first case considers a coal-based electricity supply for pumping the bio-oil through a pipeline; the second case considers an electricity supply from a renewable resource. The two cases of pipeline transport are compared to two cases of truck transport (truck trailer and super B-train truck). The life cycle greenhouse gas (GHG) emissions from the pipeline transport of bio-oil for the two cases of electricity supply are 345 and 17 g of CO(2) m(-3) km(-1), respectively. Similar values for transport by trailer (capacity - 30 m(3)) and super B-train truck (capacity - 60 m(3)) are 89 and 60 g of CO(2) m(-3) km(-1), respectively. Energy input for bio-oil transport is 3.95 MJ m(-3) km(-1) by pipeline, 2.59 MJ m(-3) km(-1) by truck and 1.66 MJ m(-3) km(-1) by super B-train truck. The results show that GHG emissions in pipeline transport are largely dependent on the source of electricity (higher for coal-based electricity). Substituting 250 m(3) day(-1) of pipeline-transported bio-oil for coal-based electricity can mitigate about 5.1 million tonnes of CO(2) per year. Overall, this study gives a comprehensive life cycle assessment of bio-oil transport comparing pipeline and truck transport.

VizieR Online Data Catalog: NGC 2264, NGC 2547 and NGC 2516 stellar radii (Jackson+, 2016)

NASA Astrophysics Data System (ADS)

Jackson, R. J.; Jeffries, R. D.; Randich, S.; Bragaglia, A.; Carraro, G.; Costado, M. T.; Flaccomio, E.; Lanzafame; Lardo, C.; Monaco, L.; Morbidelli, L.; Smiljanic, R.; Zaggia, S.

2015-11-01

File Table1.dat contains Photometric and spectroscopic data of GES Survey targets in clusters in NGC 2547, NGC 2516, NGC 22264 downloaded from the Edinburugh GES archive (http://ges/roe.ac.uk/) . Photometric data comprised the (Cousins) I magnitude and 2MASS J, H and K magnitudes. Spectroscopic data comprises the signal to noise ratio, S/N of the target spectrum, the radial velocity, RV (in km/s), the projected equatorial velocity, vsini (in km/s), the number of separate observations co-added to produce the target spectrum and the log of effective temperature (logTeff) of the template spectrum fitted to measure RV and vsini. The absolute precision in RV, pRV (in km/s) and relative precision vsini (pvsini) were estimated, as a function of the logTeff, vsini and S/N, using the prescription described in Jackson et al. (2015A&A...580A..75J, Cat. J/A+A/580/A75). File Table3.dat contains measured and calculated properties of cluster targets with resolved vsini and a reported rotation period. The cluster name, right ascension, RA (deg) and declination, Dec (deg) are given for targets with measured periods given in the literature. Dynamic properties comprise: the radial velocity, RV (in km/s), the absolute precision in RV, pRV (km/s), the projected equatorial velocity, vsini (in km/s), the relative precision in vsini (pvsini) and the rotational period (in days). Also shown are values of absolute K magnitude, MK log of luminosity, log L (in solar units) and probability of cluster membership estimated using cluster data given in the text. Period shows reported values of cluster taken from the literature Estimated values of the projected radius, Rsini (in Rsolar) and uncertainty in projected radius, e_Rsini (in Rsolar) are given for targets where vsini>5km/s and pvsini>0.2. The final column shows a flag which is set to 1 for targets in cluster NGC 2264 where a (H-K) versus (J-H) colour-colour plot indicates possible infra-red excess. Period shows reported values of cluster taken from the literature (2 data files).

Sprint profile of professional female soccer players during competitive matches: Female Athletes in Motion (FAiM) study.

PubMed

Vescovi, Jason D

2012-01-01

The aim of this study was to determine sprint profiles of professional female soccer players and evaluate how various speed thresholds impact those outcomes. Seventy-one professional players competing in full matches were assessed repeatedly during 12 regular season matches using a Global Positioning System (GPS). Locomotion ≥18 km · h⁻¹ was defined as sprinting and each event was classified into: Zone 1: 18.0-20.9 km· h⁻¹; Zone 2: 21.0-22.9 km · h⁻¹; Zone 3: 23.0-24.9 km · h⁻¹ and Zone 4: >25 km · h⁻¹. Outcomes included: duration (s), distance (m), maximum speed (km · h⁻¹), duration since previous sprint (min) and proportion of total sprint distance. In total 5,019 events were analysed from 139 player-matches. Mean sprint duration, distance, maximum speed and time between sprints were 2.3 ± 1.5 s, 15.1 ± 9.4 m, 21.8 ± 2.3 km· h⁻¹, and 2.5 ± 2.5 min, respectively. Mean sprint distances were 657 ± 157, 447 ± 185, and 545 ± 217 m for forwards, midfielders and defenders, respectively (P ≤ 0.046). Midfielders had shorter sprint duration (P = 0.023), distance (P ≤ 0.003) and maximum speed (P < 0.001), whereas forwards performed more sprints per match (43 ± 10) than midfielders (31 ± 11) and defenders (36 ± 12) (P ≤ 0.016). Forty-five percent, 29%, 15%, and 11% of sprints occurred in sprint Zones 1, 2, 3 and 4, respectively. This group of professional female soccer players covered 5.3 ± 2.0% of total distance ≥18 km · h⁻¹ with positional differences and percent decrements distinct from other previously identified elite players. These data should guide the development of high intensity and sprint thresholds for elite-standard female soccer players.

Storm impacts upon the composition of organic matrices in Nagara River--a study based on molecular weight and activated carbon adsorbability.

PubMed

Li, Fusheng; Yuasa, Akira; Chiharada, Hajime; Matsui, Yoshihiko

2003-09-01

The impacts of a heavy storm of rain on the composition of natural organic matter (NOM) in Nagara River water were studied in terms of molecular weights (MWs) and activated carbon (AC) adsorbabilities using six water samples collected during a critical Typhoon weather condition. The composition in MWs was analyzed using a HPSEC system and that in adsorbabilities was characterized using parameters devised to reflect NOMs average adsorptive strength (K(M)), adsorptive strength polydispersity (sigma), affinity to AC (1/n) and non-adsorbable fraction (C(non)/C(T0)), respectively. These parameters were determined by model description of observed isotherms with a distributed fictive component method. The heavy storm of rain brought higher content of larger organic components into the river source, thus causing changes of NOMs weight-averaged MWs in the range of 2962-3495 Dalton and MW polydispersity in the narrow range of 1.153-1.226. Comparison of K(M) and sigma values for all samples assessed with both indices of TOC and UV260 showed that large proportions of the storm-induced organic components had adsorptive strengths similar to those existent before the storm, with the presence levels for components revealing much strong and weak adsorbabilities being low. Among all organic components brought into the river by the storm of rain, the percentages of non-adsorbable ones was lower (smaller C(non)/C(T0) values); and the adsorbable ones had generally more affinity to the adsorbents used (smaller 1/n values).

Properties and mutation studies of a bacteriophage-derived chimeric recombinant staphylolytic protein P128

PubMed Central

Saravanan, Sanjeev Rajagopalan; Paul, Vivek Daniel; George, Shilpa; Sundarrajan, Sudarson; Kumar, Nirmal; Hebbur, Madhavi; Kumar, Naveen; Veena, Ananda; Maheshwari, Uma; Appaiah, Chemira Biddappa; Chidambaran, Muralidharan; Bhat, Anuradha Gopal; Hariharan, Sukumar; Padmanabhan, Sriram

2013-01-01

P128 is a chimeric anti-staphylococcal protein having a catalytic domain from a Staphylococcus bacteriophage K tail associated structural protein and a cell wall targeting domain from the Staphylococcus bacteriocin-lysostaphin. In this study, we disclose additional properties of P128 and compared the same with lysostaphin. While lysostaphin was found to get inactivated by heat and was inactive on its parent strain S. simulans biovar staphylolyticus, P128 was thermostable and was lytic towards S. simulans biovar staphylolyticus demonstrating a difference in their mechanism of action. Selected mutation studies of the catalytic domain of P128 showed that arginine and cysteine, at 40th and 76th positions respectively, are critical for the staphylolytic activity of P128, although these amino acids are not conserved residues. In comparison to native P128, only the R40S mutant (P301) was catalytically active on zymogram gel and had a similar secondary structure, as assessed by circular dichroism analysis and in silico modeling with similar cell binding properties. Mutation of the arginine residue at 40th position of the P128 molecule caused dramatic reduction in the Vmax (∆OD600 [mg/min]) value (nearly 270 fold) and the recombinant lysostaphin also showed lesser Vmax value (nearly 1.5 fold) in comparison to the unmodified P128 protein. The kinetic parameters such as apparent Km (Km APP) and apparent Kcat (KcatAPP) of the native P128 protein also showed significant differences in comparison to the values observed for P301 and lysostaphin. PMID:24251076

Experimental characterization of a coaxial plasma accelerator for a colliding plasma experiment

NASA Astrophysics Data System (ADS)

Wiechula, J.; Hock, C.; Iberler, M.; Manegold, T.; Schönlein, A.; Jacoby, J.

2015-04-01

We report experimental results of a single coaxial plasma accelerator in preparation for a colliding plasma experiment. The utilized device consisted of a coaxial pair of electrodes, accelerating the plasma due to J ×B forces. A pulse forming network, composed of three capacitors connected in parallel, with a total capacitance of 27 μF was set up. A thyratron allowed to switch the maximum applied voltage of 9 kV. Under these conditions, the pulsed currents reached peak values of about 103 kA. The measurements were performed in a small vacuum chamber with a neutral-gas prefill at gas pressures between 10 Pa and 14 000 Pa. A gas mixture of ArH2 with 2.8% H2 served as the discharge medium. H2 was chosen in order to observe the broadening of the Hβ emission line and thus estimate the electron density. The electron density for a single plasma accelerator reached peak values on the order of 1016 cm-3 . Electrical parameters, inter alia inductance and resistance, were determined for the LCR circuit during the plasma acceleration as well as in a short circuit case. Depending on the applied voltage, the inductance and resistance reached values ranging from 194 nH to 216 nH and 13 mΩ to 23 mΩ, respectively. Furthermore, the plasma velocity was measured using a fast CCD camera. Plasma velocities of 2 km/s up to 17 km/s were observed, the magnitude being highly correlated with gas pressure and applied voltage.

Seismic attenuation structure of the Seattle Basin, Washington State from explosive-source refraction data

USGS Publications Warehouse

Li, Q.; Wilcock, W.S.D.; Pratt, T.L.; Snelson, C.M.; Brocher, T.M.

2006-01-01

We used waveform data from the 1999 SHIPS (Seismic Hazard Investigation of Puget Sound) seismic refraction experiment to constrain the attenuation structure of the Seattle basin, Washington State. We inverted the spectral amplitudes of compressional- and shear-wave arrivals for source spectra, site responses, and one- and two-dimensional Q-1 models at frequencies between 1 and 40 Hz for P waves and 1 and 10 Hz for S waves. We also obtained Q-1 models from t* values calculated from the spectral slopes of P waves between 10 and 40 Hz. One-dimensional inversions show that Qp at the surface is 22 at 1 Hz, 130 at 5 Hz, and 390 at 20 Hz. The corresponding values at 18 km depth are 100, 440, and 1900. Qs at the surface is 16 and 160 at 1 Hz and 8 Hz, respectively, increasing to 80 and 500 at 18 km depth. The t* inversion yields a Qp model that is consistent with the amplitude inversions at 20 and 30 Hz. The basin geometry is clearly resolved in the t* inversion, but the amplitude inversions only imaged the basin structure after removing anomalously high-amplitude shots near Seattle. When these shots are removed, we infer that Q-1 values may be ???30% higher in the center of the basin than the one-dimensional models predict. We infer that seismic attenuation in the Seattle basin will significantly reduce ground motions at frequencies at and above 1 Hz, partially countering amplification effects within the basin.

Ecological Risk Assessment of Land Use Change in the Poyang Lake Eco-economic Zone, China

PubMed Central

Xie, Hualin; Wang, Peng; Huang, Hongsheng

2013-01-01

Land use/land cover change has been attracting increasing attention in the field of global environmental change research because of its role in the social and ecological environment. To explore the ecological risk characteristics of land use change in the Poyang Lake Eco-economic Zone of China, an eco-risk index was established in this study by the combination of a landscape disturbance index with a landscape fragmentation index. Spatial distribution and gradient difference of land use eco-risk are analyzed by using the methods of spatial autocorrelation and semivariance. Results show that ecological risk in the study area has a positive correlation, and there is a decreasing trend with the increase of grain size both in 1995 and 2005. Because the area of high eco-risk value increased from 1995 to 2005, eco-environment quality declined slightly in the study area. There are distinct spatial changes in the concentrated areas with high land use eco-risk values from 1995 to 2005. The step length of spatial separation of land use eco-risk is comparatively long—58 km in 1995 and 11 km in 2005—respectively. There are still nonstructural factors affecting the quality of the regional ecological environment at some small-scales. Our research results can provide some useful information for land eco-management, eco-environmental harnessing and restoration. In the future, some measures should be put forward in the regions with high eco-risk value, which include strengthening land use management, avoiding unreasonable types of land use and reducing the degree of fragmentation and separation. PMID:23343986

Moonlighting Glutamate Formiminotransferases Can Functionally Replace 5-Formyltetrahydrofolate Cycloligase*

PubMed Central

Jeanguenin, Linda; Lara-Núñez, Aurora; Pribat, Anne; Mageroy, Melissa Hamner; Gregory, Jesse F.; Rice, Kelly C.; de Crécy-Lagard, Valérie; Hanson, Andrew D.

2010-01-01

5-Formyltetrahydrofolate (5-CHO-THF) is formed by a side reaction of serine hydroxymethyltransferase. Unlike other folates, it is not a one-carbon donor but a potent inhibitor of folate enzymes and must therefore be metabolized. Only 5-CHO-THF cycloligase (5-FCL) is generally considered to do this. However, comparative genomic analysis indicated (i) that certain prokaryotes lack 5-FCL, implying that they have an alternative 5-CHO-THF-metabolizing enzyme, and (ii) that the histidine breakdown enzyme glutamate formiminotransferase (FT) might moonlight in this role. A functional complementation assay for 5-CHO-THF metabolism was developed in Escherichia coli, based on deleting the gene encoding 5-FCL (ygfA). The deletion mutant accumulated 5-CHO-THF and, with glycine as sole nitrogen source, showed a growth defect; both phenotypes were complemented by bacterial or archaeal genes encoding FT. Furthermore, utilization of supplied 5-CHO-THF by Streptococcus pyogenes was shown to require expression of the native FT. Recombinant bacterial and archaeal FTs catalyzed formyl transfer from 5-CHO-THF to glutamate, with kcat values of 0.1–1.2 min−1 and Km values for 5-CHO-THF and glutamate of 0.4–5 μm and 0.03–1 mm, respectively. Although the formyltransferase activities of these proteins were far lower than their formiminotransferase activities, the Km values for both substrates relative to their intracellular levels in prokaryotes are consistent with significant in vivo flux through the formyltransferase reaction. Collectively, these data indicate that FTs functionally replace 5-FCL in certain prokaryotes. PMID:20952389

P-wave Velocity Structure in the Lowermost 600 km of the Mantle beneath Western Pacific Inferred from Travel Times and Amplitudes Observed with NECESSArray

NASA Astrophysics Data System (ADS)

Tanaka, S.; Kawakatsu, H.; Chen, Y. J.; Ning, J.; Grand, S. P.; Niu, F.; Obayashi, M.; Miyakawa, K.; Idehara, K.; Tonegawa, T.; Iritani, R.; Necessarray Project Team

2011-12-01

NECESSArray is a large-scale broadband seismic array deployed in northeastern China. Although its primary aims are to reveal the fate of subducted Pacific plate and to address several tectonic issues, it is also useful as a large aperture array to look at deep Earth. Here, we examine P-wave travel times observed with NECESSArray to determine P-wave velocity structure in the lower mantle beneath Western Pacific. Relative travel times with respect to those predicted by PREM are measured on short period seismograms from 15 earthquakes occurred in Tonga, Fiji, and Kermadec regions since Sep. 2009 to April 2010, so far, by using adaptive stacking method [Rawlinson and Kennett, 2004]. The residuals are defined as fluctuations with respect to an average of the whole array for each event. Station correction is defined as a median value of the residuals at each station. After applying the station corrections and distance corrections for the surface focus, we synthesize all the residuals and finally obtain a characteristic residual variation as a function of epicentral distance from 80 to 95 degrees. The travel time residuals show an inverted V-pattern with the maximum delay of 0.2 s at 87 degrees compared from a reference level at 80 and 95 degrees. To simply interpret this pattern through Herglotz-Wiechert inversion, we assume that the velocity structure above 600 km above the core-mantle boundary (CMB) is identical to PREM and find that the difference of the P-wave velocities from those of PREM gradually increase with depth, and reach the maximum velocity reduction of 0.15% and suddenly increase to those being identical to PREM at 270 km above the CMB. Thickness of a small velocity gradient layer at the base of the mantle is reduced to be 130 km instead of 150 km that is PREM's value. P-wave amplitudes are used as supplementary data. Station corrections for amplitude are inferred from 6 deep Fiji earthquakes in the distance range 75 to 90 degrees, in which focal mechanisms are corrected with the Global CMT solutions and theoretical amplitude variations due to elastic and anelastic structures with the reflectivity method are considered. The corrected amplitude that are sensitive to the velocity structure just the above the CMB are obtained from 3 earthquakes occurred in Kermadec islands (their latitudes vary from 29.2 S to 31.6S) in the distance range from 86 to 96 degrees. Although they are closely located each other, the data from the southernmost event indicate significantly rapid amplitude decay, and those from the northernmost event indicate moderate amplitude decay, those from the middle event show a large scatter. This observation suggests that a rapid horizontal change of the D" structure exists in the southwestern edge of the sampled region.

Oxygen, pH, and mitochondrial oxidative phosphorylation.

PubMed

Wilson, David F; Harrison, David K; Vinogradov, Sergei A

2012-12-15

The oxygen dependence of mitochondrial oxidative phosphorylation was measured in suspensions of isolated rat liver mitochondria using recently developed methods for measuring oxygen and cytochrome c reduction. Cytochrome-c oxidase (energy conservation site 3) activity of the mitochondrial respiratory chain was measured using an artificial electron donor (N,N,N',N'-tetramethyl-p-phenylenediamine) and ascorbate to directly reduce the cytochrome c, bypassing sites 1 and 2. For mitochondrial suspensions with added ATP, metabolic conditions approximating those in intact cells and decreasing oxygen pressure both increased reduction of cytochrome c and decreased respiratory rate. The kinetic parameters [K(M) and maximal rate (V(M))] for oxygen were determined from the respiratory rates calculated for 100% reduction of cytochrome c. At 22°C, the K(M) for oxygen is near 3 Torr (5 μM), 12 Torr (22 μM), and 18 Torr (32 μM) at pH 6.9, 7.4, and 7.9, respectively, and V(M) corresponds to a turnover number for cytochrome c at 100% reduction of near 80/s and is independent of pH. Uncoupling oxidative phosphorylation increased the respiratory rate at saturating oxygen pressures by twofold and decreased the K(M) for oxygen to <2 Torr at all tested pH values. Mitochondrial oxidative phosphorylation is an important oxygen sensor for regulation of metabolism, nutrient delivery to tissues, and cardiopulmonary function. The decrease in K(M) for oxygen with acidification of the cellular environment impacts many tissue functions and may give transformed cells a significant survival advantage over normal cells at low-pH, oxygen-limited environment in growing tumors.

Fine-scale variability of isopycnal salinity in the California Current System

NASA Astrophysics Data System (ADS)

Itoh, Sachihiko; Rudnick, Daniel L.

2017-09-01

This paper examines the fine-scale structure and seasonal fluctuations of the isopycnal salinity of the California Current System from 2007 to 2013 using temperature and salinity profiles obtained from a series of underwater glider surveys. The seasonal mean distributions of the spectral power of the isopycnal salinity gradient averaged over submesoscale (12-30 km) and mesoscale (30-60 km) ranges along three survey lines off Monterey Bay, Point Conception, and Dana Point were obtained from 298 transects. The mesoscale and submesoscale variance increased as coastal upwelling caused the isopycnal salinity gradient to steepen. Areas of elevated variance were clearly observed around the salinity front during the summer then spread offshore through the fall and winter. The high fine-scale variances were observed typically above 25.8 kg m-3 and decreased with depth to a minimum at around 26.3 kg m-3. The mean spectral slope of the isopycnal salinity gradient with respect to wavenumber was 0.19 ± 0.27 over the horizontal scale of 12-60 km, and 31%-35% of the spectra had significantly positive slopes. In contrast, the spectral slope over 12-30 km was mostly flat, with mean values of -0.025 ± 0.32. An increase in submesoscale variability accompanying the steepening of the spectral slope was often observed in inshore areas; e.g., off Monterey Bay in winter, where a sharp front developed between the California Current and the California Under Current, and the lower layers of the Southern California Bight, where vigorous interaction between a synoptic current and bottom topography is to be expected.

Stratospheric ozone variations in the equatorial region as seen in Stratiospheric Aerosol and Gas Experiment data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiotani, M.; Hasebe, F.

1994-07-01

An analysis is made of equatorial ozone variations for 5 years, 1984-1989, using the ozone profile data derived from the Stratospheric Aerosol and Gas Experiment II (SAGE II) instrument. Attention is focused on the annual cycle and also on interannual variability, particularly the quasi-biennial oscillation (QBO) and El Nino-Southern Oscillation (ENSO) variations in the lower stratosphere, where the largest contribution to total column ozone takes place. The annual variation in zonal mean total ozone around the equator is composed of symmetric and asymmetric modes with respect to the equator, with maximum contributions being around 19 km for the symmetric modemore » and around 25 km for the asymmetric mode. The persistent zonal wavenumber 1 structure observed by the total ozone mapping spectrometer over the equator is almost missing in the SAGE-derived column amounts integrated in the stratosphere, suggesting a significant contribution from tropospheric ozone. Interannual variations in the equatorial ozone are dominated by the QBO above 20 km and the ENSO-related variation below 20 km. The ozone QBO is characterized by zonally uniform phase changes in association with the zonal wind QBO in the equatorial lower stratosphere. The ENSO-related ozone variation consists of both the east-west vacillation and the zonally uniform phase variation. During the El Nino event, the east-west contrast with positive (negative) deviations in the eastern (western) hemisphere is conspicuous, while the decreasing tendency of the zonal mean values is maximum at the same time.« less

Stratospheric ozone variations in the equatorial region as seen in Stratospheric and Gas Experiment data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masato Shiotani; Fumio Hasebe

1994-07-20

An analysis is made of equatorial ozone variations for 5 years, 1984-1989, using the ozone profile data derived from the Stratospheric Aerosol and Gas Experiment II (SAGE II) instrument. Attention is focused on the annual cycle and also on interannual variability, particularly the quasi-biennial oscillation (QBO) and El Nino-Southern Oscillation (ENSO) variations in the lower stratosphere, where the largest contribution to total column ozone takes place. The annual variation in zonal mean total ozone around the equator is composed of symmetric and asymmetric modes with respect to the equator, with maximum contributions being around 19 km for the symmetric modemore » and around 25 km for the asymmetric mode. The persistent zonal wavenumber 1 structure observed by the total ozone mapping spectrometer over the equator is almost missing in the SAGE-derived column amounts integrated in the stratosphere, suggesting a significant contribution from tropospheric ozone. Interannual variations in the equatorial ozone are dominated by the QBO above 20 km and the ENSO-related variation below 20 km. The ozone QBO is characterized by zonally uniform phase changes in association with the zonal wind QBO in the equatorial lower stratosphere. The ENSO-related ozone variation consists of both the east-west vacillation and the zonally uniform phase variation. During the El Nino event, the east-west contrast with positive (negative) deviations in the eastern (western) hemisphere is conspicuous, while the decreasing tendency of the zonal mean values is maximum at the same time. 28 refs., 13 figs.« less

Ice-front change and iceberg behaviour along Oates and George V Coasts, Antarctica, 1912-96

USGS Publications Warehouse

Frezzotti, M.; Cimbelli, A.; Ferrigno, J.G.

1998-01-01

Ice-front change may well be a sensitive indicator of regional climate change. We have studied the western Oates Coast from Cape Kinsey (158??50'E, 69??19'S) to Cape Hudson (153??45'E, 68??20'S) and the entire George V Coast, from Cape Hudson to Point Alden (142??02'E, 66??48'S). The glaciers here drain part of the Dome Charlie and Talos Dome areas (640 000 km2). A comparison between various documents, dated several years apart, has allowed an estimate of the surficial ice discharge, the ice-front fluctuation and the iceberg-calving flux during the last 50 years. The ice-front discharge of the studied coast has been estimated at about 90??12 km3 a-1 in 1989-91, 8.5 km3 a-1 for western Oates Coast and 82 km3 a-1 for George V Coast. From 1962-63 to 1973-74 the floating glaciers underwent a net reduction that continued from 1973-74 to 1989-91. On the other hand, from 1989-91 to 1996 the area of floating glaciers increased. Ninnis Glacier Tongue and the western part of Cook Ice Shelf underwent a significant retreat after 1980 and 1947, respectively. Satellite-image analysis of large icebergs has provided information about ice-ocean interaction and the existence of an 'iceberg trap' along George V Coast. A first estimate of the mass balance of the drainage basin of Mertz and Ninnis Glaciers shows a value close to zero or slightly negative.

The Cretaceous Okhotsk-Chukotka Volcanic Belt (NE Russia): Geology, geochronology, magma output rates, and implications on the genesis of silicic LIPs

NASA Astrophysics Data System (ADS)

Tikhomirov, P. L.; Kalinina, E. A.; Moriguti, T.; Makishima, A.; Kobayashi, K.; Cherepanova, I. Yu.; Nakamura, E.

2012-04-01

The Cretaceous Okhotsk-Chukotka volcanic belt (OCVB) is a prominent subduction-related magmatic province, having the remarkably high proportion of silicic rocks (ca. 53% of the present-day crop area, and presumably over 70% of the total volcanic volume). Its estimated total extrusive volume ranges between 5.5 × 105 km3 (the most conservative estimate) and over 106 km3. This article presents a brief outline of the geology of OCVB, yet poorly described in international scientific literature, and results of a geochronological study on the northern part of the volcanic belt. On the base of new and published U-Pb and 40Ar/39Ar age determinations, a new chronological model is proposed. Our study indicates that the activity of the volcanic belt was highly discontinuous and comprised at least five main episodes at 106-98 Ma, 94-91 Ma, 89-87 Ma, 85.5-84 Ma, and 82-79 Ma. The new data allow a semi-quantitative estimate of the volcanic output rate for the observed part of the OCVB (area and volume approximately 105 km2 and 2.5 × 105 km3, respectively). The average extrusion rate for the entire lifetime of the volcanic belt ranges between 1.6 and 3.6 × 10- 5 km3yr- 1 km- 1, depending on the assumed average thickness of the volcanic pile; the optimal value is 2.6 × 10- 5 km3yr- 1 km- 1. Despite imprecise, such estimates infer the time-averaged volcanic productivity of the OCVB is similar to that of silicic LIPs and most active recent subduction-related volcanic areas of the Earth. However, the most extensive volcanic flare-ups at 89-87 and 85.5-84 Ma had higher rates of over 9.0 × 10- 5 km3yr- 1 km- 1. The main volumetric, temporal and compositional parameters of the OCVB are similar to those of silicic LIPs. This gives ground for discussion about the geodynamic setting of the latters, because the widely accepted definition of a LIP implies a strictly intraplate environment. Considering the genesis of the OCVB and other large provinces of silicic volcanism, we propose that residual thermal energy preserved in the continental crust after a previous major magmatic event may have been one of major reasons for high proportion of felsic rocks in a volcanic pile. In this scenario, underplating of mantle-derived basalts causes fast and extensive melting of still hot continental crust and generation of voluminous silicic magmas.

Soil erosion rates (particulate and dissolved fluxes) variations in a temperate river basin

NASA Astrophysics Data System (ADS)

Cerdan, Olivier; Gay, Aurore; Négrel, Philippe; Pételet-Giraud, Emmanuelle; Salvador Blanes, Sébastien; Degan, Francesca

2015-04-01

Soil erosion is one of the major drivers of landscape evolution in Western Europe. However, depending on the land use characteristics and on the geological and topographical settings, miscellaneous forms of erosion may lead to a very diverse morphological evolution. To understand these landscape evolutions different scientific questions remain to be answered or quantified. The main difficulty arises from the nonlinear interactions between different erosional processes that act at different temporal and spatial scales. This study proposes to investigate different datasets describing particulate and dissolved sediment fluxes within a French River basin (The Loire River) at different spatial scales and at temporal scales ranging from the flood event to several decades. The particulate sediment load values at the outlet of the catchments range from 2.5 102 to 8.6 105 t yr-1, and the sediment yield values range from 2.9 to 32.4 t km 2 yr-1. Sediment exports from the Loire and Brittany river basins are low compared with mountainous regions and European exports. However, a strong spatial variability within this territory exists. The expected results on the sediment yield spatial pattern distribution and the correlation between SY values and basin sizes are not observed. An analysis of the sediment yield values at different time steps shows a strong effect of the seasonal availability of detached particles to be transported. High concentrations of suspended sediments during the winter and lower values during the summer and autumn are observed. Inter-annual variations are also observed, with export values varying by a factor 2 to 10 between years for one catchment. The influence of rainfall on the sediment exports is predominant, but investigations on physical characteristics of each catchment (e.g., lithology, slope, land use) are required to better understand the production and transfer processes within a drainage basin. These inter-annual variations imply that long-term data are required to provide mean SY values representative of the catchment functioning. From our calculations, 18 complete years of data are required to obtain a mean sediment yield value with less than 10% of variation on average around the mean. The specific dissolved fluxes vary from 13.7 to 199.9 t.km-2. t yr-1. Contrary to particulate matters, the impact of the lithology is illustrated by higher total dissolved solid fluxes on limestone catchments compared with graniteous or schisteous catchments. Nitrates and ammonium are indicators of anthropogenic perturbation and their fluxes vary respectively from 0.4 to 31.4 t.km-2. yr-1 and from 7.8*10-3 to 7.7 t.km-2. yr-1 and evolve differently according to land uses: nitrates fluxes are lower in the upstream Loire and higher downstream in the region where agricultural pressure is higher. The analysis of these datasets at different spatial and temporal scales permits to identify some of the dominant processes, and also to distinguish natural from anthropogenic influences. Concerning upland physical soil surface erosion rates, we find that the average travel distance of eroded particles may be limited, implying a strong decrease in physical erosion rates when moving from the local scale (m²) to the river basin scale (> 103 km²). Chemical erosion rates are less sensitive to scale and can either decrease or increase with increasing area in function of lithology, land management and topography. The results also highlight the predominant role of surface connectivity to characterize the fraction of sediment exported out of river drainage areas by physical soil surface erosion. For the export of dissolved sediment originating from weathering processes, the catchment physiography and connectivity does no longer play the dominant role. A direct link between soil production rates and exported dissolved fluxes tends to show that, contrary to the suspended particles, which are transport-limited, the dissolved matter seems to be supply-limited.

The long-term strength of Europe and its implications for plate-forming processes.

PubMed

Pérez-Gussinyé, M; Watts, A B

2005-07-21

Field-based geological studies show that continental deformation preferentially occurs in young tectonic provinces rather than in old cratons. This partitioning of deformation suggests that the cratons are stronger than surrounding younger Phanerozoic provinces. However, although Archaean and Phanerozoic lithosphere differ in their thickness and composition, their relative strength is a matter of much debate. One proxy of strength is the effective elastic thickness of the lithosphere, Te. Unfortunately, spatial variations in Te are not well understood, as different methods yield different results. The differences are most apparent in cratons, where the 'Bouguer coherence' method yields large Te values (> 60 km) whereas the 'free-air admittance' method yields low values (< 25 km). Here we present estimates of the variability of Te in Europe using both methods. We show that when they are consistently formulated, both methods yield comparable Te values that correlate with geology, and that the strength of old lithosphere (> or = 1.5 Gyr old) is much larger (mean Te > 60 km) than that of younger lithosphere (mean Te < 30 km). We propose that this strength difference reflects changes in lithospheric plate structure (thickness, geothermal gradient and composition) that result from mantle temperature and volatile content decrease through Earth's history.

Structural and Biochemical Characterization of AidC, a Quorum-Quenching Lactonase With Atypical Selectivity

PubMed Central

Mascarenhas, Romila; Thomas, Pei W.; Wu, Chun-Xiang; Nocek, Boguslaw P.; Hoang, Quyen Q.; Liu, Dali; Fast, Walter

2015-01-01

Quorum-quenching catalysts are of interest for potential application as biochemical tools to interrogate interbacterial communication pathways, as anti-biofouling agents, and as anti-infective agents in plants and animals. Herein, the structure and function of AidC, an N-acyl-L-homoserine (AHL) lactonase from Chryseobacterium, is characterized. Steady-state kinetics show that zinc-supplemented AidC is one of the most efficient wild-type quorum-quenching enzymes characterized to date, with a kcat/KM value of approximately 2 × 106 M−1s−1 for N-heptanoyl-L-homoserine lactone. The enzyme has stricter substrate selectivity and significantly lower KM values (ca. 50 μM for preferred substrates) than typical AHL lactonases (ca. > 1 mM). X-ray crystal structures of AidC alone, and with the product N-hexanoyl-L-homoserine were determined at resolutions of 1.09 and 1.67 Å, respectively. Each structure displays as a dimer, and dimeric oligiomerization was also observed in solution by size-exclusion chromatography coupled with multi-angle light scattering. The structures reveal two atypical features as compared to previously characterized AHL lactonases: a ‘kinked’ α-helix that forms part of a closed binding pocket which provides affinity and enforces selectivity for AHL substrates, and an active-site His substitution that is usually found in a homologous family of phosphodiesterases. Implications for the catalytic mechanism of AHL lactonases are discussed. PMID:26115006

Molecular and biochemical characterization of natural and recombinant phosphoglycerate kinase B from Trypanosoma rangeli.

PubMed

Villafraz, O; Rondón-Mercado, R; Cáceres, A J; Concepción, J L; Quiñones, W

2018-04-01

T. rangeli epimastigotes contain only a single detectable phosphoglycerate kinase (PGK) enzyme in their cytosol. Analysis of this parasite's recently sequenced genome showed a gene predicted to code for a PGK with the same molecular mass as the natural enzyme, and with a cytosolic localization as well. In this work, we have partially purified the natural PGK from T. rangeli epimastigotes. Furthermore, we cloned the predicted PGK gene and expressed it as a recombinant active enzyme. Both purified enzymes were kinetically characterized and displayed similar substrate affinities, with Km ATP values of 0.13 mM and 0.5 mM, and Km 3PGA values of 0.28 mM and 0.71 mM, for the natural and recombinant enzyme, respectively. The optimal pH for activity of both enzymes was in the range of 8-10. Like other PGKs, TrPGK is monomeric with a molecular mass of approximately 44 kDa. The enzyme's kinetic characteristics are comparable with those of cytosolic PGK isoforms from related trypanosomatid species, indicating that, most likely, this enzyme is equivalent with the PGKB that is responsible for generating ATP in the cytosol of other trypanosomatids. This is the first report of a glycolytic enzyme characterization from T. rangeli. Copyright © 2018 Elsevier Inc. All rights reserved.

Purification and characterization of a p-coumarate decarboxylase and a vinylphenol reductase from Brettanomyces bruxellensis.

PubMed

Godoy, Liliana; Martínez, Claudio; Carrasco, Nelson; Ganga, María Angélica

2008-09-30

The presence of Brettanomyces bruxellensis has been correlated with an increase of phenolic aromas in wine. The production of these aromas results from the metabolization of cinnamic acids, present in the wine, to their ethyl derivatives. Hence, the participation of two enzymes has been proposed: a p-coumarate decarboxylase (CD) and a vinylphenol reductase (VR). Both enzymes were purified and characterized from B. bruxellensis. In denaturing conditions, the CD enzyme had a molecular mass of 21 kDa, while in native conditions its mass was 41 kDa. The optimal activity was obtained at a temperature of 40 degrees C and a pH of 6.0. For p-coumaric acid, the Km value and Vmax were 1.22+/-0.08 mM and 98+/-0.15 micromol/min mg, respectively. The VR enzyme had a molecular mass of 37 kDa in SDS-PAGE, while in natural conditions its mass was 118 kDa. The Km value was > 3.37+/-2.05 mM and its Vmax was 107.62+/-50.38 micromol/min mg for NADPH used as a cofactor. Both enzymatic activities were stable at pH 3.4, but in the presence of ethanol the CD activity decreased drastically while the VR activity was more stable. This is the first report that shows the presence of a CD and a VR enzyme in B. bruxellensis.

Shinrin-yoku (forest-air bathing and walking) effectively decreases blood glucose levels in diabetic patients

NASA Astrophysics Data System (ADS)

Ohtsuka, Y.; Yabunaka, Noriyuki; Takayama, Shigeru

The influence of ''shinrin-yoku'' (forest-air bathing and walking) on blood glucose levels in diabetic patients was examined. Eighty-seven (29 male and 58 female) non-insulin-dependent diabetic patients [61 (SEM 1) years old] participated in the present study. Shinrin-yoku was performed nine times over a period of 6 years. The patients were divided into two parties. They then walked in the forest for 3 km or 6 km according to their physical ability and/or the existence of diabetic complications. The mean blood glucose level after forest walking changed from 179 (SEM 4) mg . 100 ml-1 to 108 (SEM 2) mg . 100 ml-1 (P<0.0001). The level of glycated haemoglobin A1c also decreased from 6.9 (SEM 0.2)% (before the first shinrin-yoku) to 6.5 (SEM 0.1)% (after the last shinrin-yoku; P<0.05). Blood glucose values declined by 74 (SEM 9) mg . 100 ml-1 and 70 (SEM 4) mg . 100 ml-1 after short- and long-distance walking respectively. There was no significant difference between these values. Since the forest environment causes changes in hormonal secretion and autonomic nervous functions, it is presumed that, in addition to the increased calorie consumption and improved insulin sensitivity, walking in a forest environment has other beneficial effects in decreasing blood glucose levels.

Accelerated cosmological expansion without tension in the Hubble parameter. Fast evolution of the Hubble parameter H(z)

NASA Astrophysics Data System (ADS)

van Putten, Maurice H. P. M.

2018-01-01

The H0-tension problem poses a confrontation of dark energy driving latetime cosmological expansion measured by the Hubble parameter H(z) over an extended range of redshifts z. Distinct values H0 ≃ 73 km s-1 Mpcs-1 and H0 ≃ 68 km s-1 Mpcs-1 obtain from surveys of the Local Universe and, respectively, ΛCBM analysis of the CMB. These are representative of accelerated expansion with H'(0) ≃ 0 by and, respectively, H'(0) > 0 in ΛCDM, where is a fundamental frequency of the cosmological horizon in a Friedmann-Robertson-Walker universe with deceleration parameter q(z) = -1 + (1+z)H-1 H'(z). Explicit solution H(z) = H0 and, respectively, H(z) = H0 are here compared with recent data on H(z) over 0 ≲ z ≲ 2.The first is found to be free of tension with H0 from local surveys, while the latter is disfavored at 2:7σ A further confrontation obtains in galaxy dynamics by a finite sensitivity of inertia to background cosmology in weak gravity, putting an upper bound of m ≲ 10-30 eV on the mass of dark matter. A C0 onset to weak gravity at the de Sitter scale of acceleration adS = cH(z), where c denotes the velocity of light, can be seen in galaxy rotation curves covering 0 ≲ z ≲ 2 Weak gravity in galaxy dynamics hereby provides a proxy for cosmological evolution.

Assessment of Wind Home System's Potential in Coastal Areas of Pakistan

NASA Astrophysics Data System (ADS)

Memon, Mujeebudin; Harijan, Khanji; Uqaili, Mohammad Aslam

2007-10-01

About 50 and 90 percent of the total population of rural coastal areas of Sindh and Balochistan provinces respectively have no access to electricity and meet lighting requirements through kerosene and LPG. The population density in rural coastal areas of Sindh and Balochistan provinces is about 100-150 and 10-50 persons per km2 respectively. Extension of existing centralized grid system to rural areas with very low population density and small-scattered loads is economically and technically unfeasible. In this situation, decentralized renewable electricity especially wind power appears to be one of the viable option. This paper presents the assessment of potential of wind home systems (WHS) for rural electrification in coastal areas of Pakistan using the wind speed data recorded by Pakistan Metrological Department (PMD) and power curve of a reference wind turbine. Pakistan has 1050 km long coastline, of which, 250 km is falling in Sindh and 800 km in Balochistan. A 150 Wp wind turbine could generate about 345 kWh and 250 kWh of electricity per year in coastal areas of Sindh and Balochistan respectively, which would be sufficient for meeting the electricity demand of a rural household. The average theoretical potential of WHS in the coastal area of Sindh and Balochistan is about 2245 and 1800 FLH respectively. The total installed capacity and technical potential of WHS in the coastal area of the country has been estimated as 63.75 MW and 135 GWh/year respectively.

Radar and Atmospheric Sounding observations around 23 TGFs

NASA Astrophysics Data System (ADS)

Chronis, T.; Briggs, M. S.; Priftis, G.

2014-12-01

This study employs 23 Terrestrial Gamma-ray Flashes (TGF) detected with NASA's Fermi Gamma-ray Burst Monitor (GBM) and collocated with the World Wide Lightning Location Network and the Earth Networks Total Lightning Network with 9 WSR-88D (NEXRAD) located in Brownsville and Corpus Christy (Texas), Lake Charles (Louisiana), Key West, Miami, Tampa and Eglin Air Force Base (Florida), San Juan (Puerto Rico) and Andersen Air Force Base (Guam). The NEXRAD Enhanced Echo Tops (EET) and Vertical Integrated Liquid Density (VILD) are traditional proxies to storm height and severity. To retrieve the storm characteristics we construct probability histograms of respective EET and VILD values around each TGF.Here we show that although high-topped storms are consistently present in the vicinity of TGFs, the VILD values indicate storms of disparate convective strengths. In particular, the majority of our TGF sample is encompassed by storms of high EET (>10-11 km) values and in their majority overall VILD < ~2.0 gr m-3.These EET and VILD values are common in summertime oceanic/coastal low-latitude thunderstorms where the main convective core is limited in the first few kilometres and the updrafts are weak and narrow. Qualitative observations from the temporal evolution of the volumetric radar reflectivity shows that in a few cases the TGF emission signals the dissipation stage of the main convective core, although this suggestion is tentative and requires more sophisticated and currently ongoing storm tracking techniques. The atmospheric soundings (where available in spatial and temporal proximity with the respective TGF) indicate that TGF producing storms can exhibit a significant variation in their respective thermodynamic environment and type (e.g. regular to high CAPE, pulse vs. high shear etc). The authors acknowledge the valuable contributions of the GBM Team, Bob Holtzworth (WWLLN) and Stan Heckman (ENTLN).

Disinfection by-products of chlorine dioxide (chlorite, chlorate, and trihalomethanes): Occurrence in drinking water in Qatar.

PubMed

Al-Otoum, Fatima; Al-Ghouti, Mohammad A; Ahmed, Talaat A; Abu-Dieyeh, Mohammed; Ali, Mohammed

2016-12-01

The occurrence of chlorine dioxide (ClO 2 ) disinfection by-products (DBPs) in drinking water, namely, chlorite, chlorate, and trihalomethanes (THMs), was investigated. Two-hundred-ninety-four drinking water samples were collected from seven desalination plants (DPs), four reservoirs (R), and eight mosques (M) distributed within various locations in southern and northern Qatar. The ClO 2 concentration levels ranged from 0.38 to <0.02 mg L -1 , with mean values of 0.17, 0.12, and 0.04 mg L -1 for the DPs, Rs, and Ms, respectively. The chlorite levels varied from 13 μg L -1 to 440 μg L -1 , with median values varying from 13 to 230 μg L -1 , 77-320 μg L -1 , and 85-440 μg L -1 for the DPs, Rs, and Ms, respectively. The chlorate levels varied from 11 μg L -1 to 280 μg L -1 , with mean values varying from 36 to 280 μg L -1 , 11-200 μg L -1 , and 11-150 μg L -1 in the DPs, Rs, and Ms, respectively. The average concentration of THMs was 5 μg L -1 , and the maximum value reached 77 μg L -1 However, all of the DBP concentrations fell within the range of the regulatory limits set by GSO 149/2009, the World Health Organization (WHO), and Kahramaa (KM). Copyright © 2016 Elsevier Ltd. All rights reserved.

Denudation rates of the Southern Espinhaço Range, Minas Gerais, Brazil, determined by in situ-produced cosmogenic beryllium-10

NASA Astrophysics Data System (ADS)

Barreto, Helen N.; Varajão, César A. C.; Braucher, Régis; Bourlès, Didier L.; Salgado, André A. R.; Varajão, Angélica F. D. C.

2013-06-01

To investigate denudation rates in the southern part of the Espinhaço Range (central-eastern Brazil) and to understand how this important resistant and residual relief has evolved in the past 1.38 My, cosmogenic 10Be concentrations produced in situ were measured in alluvial sediments from the three main regional basins, whose substratum is composed primarily of quartzites. The long-term denudation rates (up to 1.38 My) estimated from these measurements were compared with those that affect the western (São Francisco River) and eastern (Doce and Jequitinhonha Rivers) basins, which face the West San Francisco craton and the Atlantic, respectively. Denudation rates were measured in 27 samples collected in catchments of different sizes (6-970 km2) and were compared with geomorphic parameters. The mean denudation rates determined in the northern part are low and similar to those determined in the southern part, despite slightly different geomorphic parameter values (catchment relief and mean slope). For the southern catchments, the values are 4.91 ± 1.01 m My- 1 and 3.65 ± 1.26 m My- 1 for the Doce and São Francisco River basins, respectively; for the northern catchments, they are 4.40 ± 1.06 m My- 1 and 3.96 ± 0.91 m My- 1 for the Jequitinhonha and São Francisco River basins, respectively. These low values of denudation rates suggest no direct correlation if plotted against geomorphic parameters such as the catchment area, maximum elevation, catchment relief, average relief and mean slope gradients. These values show that the regional landscape evolves slowly and is strongly controlled by resistant lithology, with similar erosional rates in the three studied basins.

Elastic flexure controls magma trajectories and explains the offset of primary volcanic activity upstream of mantle plume axis at la Réunion and Hawaii hotspot islands

NASA Astrophysics Data System (ADS)

Gerbault, Muriel; Fontaine, Fabrice J.; Rabinowicz, Michel; Bystricky, Misha

2017-03-01

Surface volcanism at la Réunion and Hawaii occurs with an offset of 150-180 km upstream to the plume axis with respect to the plate motion. This striking observation raises questions about the forcing of plume-lithosphere thermo-mechanical interactions on melt trajectories beneath these islands. Based on visco-elasto-plastic numerical models handled at kilometric resolution, we propose to explain this offset by the development of compressional stresses at the base of the lithosphere, that result from elastic plate bending above the upward load exerted by the plume head. This horizontal compression adopts a disc shape centered around the plume axis: (i) it is 20 km thick, (ii) it has a 150 km radius, (iii) it lays at the base of the elastic part of the lithosphere, i.e., around ∼50-70 km depth where the temperature varies from ∼600 °C to ∼750 °C, (iv) it lasts for 5 to 10 My in an oceanic plate of age greater than 70 My, and (vi) it is controlled by the visco-elastic relaxation time at ∼50-70 km depth. This period of time exceeds the time during which both the Somalian/East-African and Pacific plates drift over the Reunion and Hawaii plumes, respectively. This indicates that this basal compression is actually a persistent feature. It is inferred that the buoyant melts percolating in the plume head pond below this zone of compression and eventually spread laterally until the most compressive principal elastic stresses reverse to the vertical, i.e., ∼150 km away from the plume head. There, melts propagate through dikes upwards to ∼35 km depth, where the plate curvature reverses and ambient compression diminishes. This 30-35 km depth may thus host a magmatic reservoir where melts transported by dykes pond. Only after further magmatic differentiation can dykes resume their ascension up to the surface and begin forming a volcanic edifice. As the volcano grows because of melt accumulation at the top of the plate, the lithosphere is flexed downwards, inducing extra tensile stress at 30-35 km depth and compression at ∼15 km depth (induced by the edifice load). It implies that now the melts pond at ∼15 km and form another magmatic reservoir lying just underneath the crust. These processes explain the ponding of primary (shield) melts at ∼35 km and ∼15 km depths as recorded below La Reunion, Mauritius or Hawaii volcanoes, all shifted by ∼150 km with respect to the plume axis.

Hα line measurements from ten diffuse galactic sources using the DEFPOS facility

NASA Astrophysics Data System (ADS)

Sahan, M.; Oflaz, F. M.; Yegingil, I.; Tel, E.

2015-08-01

The hydrogen Balmer-α emission line spectrum of ten diffuse ionization sources in the Milk Way - NGC 40 (WC8), NGC 2022, NGC 6210, NGC 6618 (M17, Sh2-45), NGC 6720 (M57), NGC 6781, NGC 6888 (Sh2-105), NGC 6992 (Sh2-103), NGC 7635 (Sh2-162,) and IC 1848 (Sh2-199) - has been investigated using a dual etalon Fabry-Pérot optical spectrometer (DEFPOS) aatached to the 150 cm RTT150 telescope at TUBITAK National Observatory (TUG, Antalya, Turkey: 36° 51' N; 30° 20' E; elevation: 2547 m). All of our galactic Hα observations discussed in this paper were carried out during the nights of 2013 June 21-24 with exposure time of 3600 s. As main results the intensity, the full width at half maximum, and the radial velocity with respect to the LSR have been determined for each data set. The intensities, the radial velocities, and the line widths of the Hα emission line vary from 59.15 to 8923.44 R, -46.72 to +54.07 km s-1, and 31.4 to 48.01 km s-1, respectively. The radial velocities and the half-widths of the H II regions and planetary nebulae determined from our measurements are found to be consistent with values given in literature, especially with those in Schneider et al. (1983) and Fich et al. (1990).

Comparison of Free and Immobilized L-asparaginase Synthesized by Gamma-Irradiated Penicillium cyclopium.

PubMed

El-Refai, Heba A; Shafei, Mona S; Mostafa, Hanan; El-Refai, Abdel-Monem H; Araby, Eman M; El-Beih, Fawkia M; Easa, Saadia M; Gomaa, Sanaa K

2016-01-01

Gamma irradiation is used on Penicillium cyclopium in order to obtain mutant cells of high L-asparaginase productivity. Using gamma irradiation dose of 4 KGy, P. cyclopium cells yielded L-asparaginase with extracellular enzyme activity of 210.8 ± 3 U/ml, and specific activity of 752.5 ± 1.5 U/mg protein, which are 1.75 and 1.53 times, respectively, the activity of the wild strain. The enzyme was partially purified by 40-60% acetone precipitation. L-asparaginase was immobilized onto Amberlite IR-120 by ionic binding. Both free and immobilized enzymes exhibited maximum activity at pH 8 and 40 degrees C. The immobilization process improved the enzyme thermal stability significantly. The immobilized enzyme remained 100% active at temperatures up to 60 degrees C, while the free asparaginase was less tolerant to high temperatures. The immobilized enzyme was more stable at pH 9.0 for 50 min, retaining 70% of its relative activity. The maximum reaction rate (V(max)) and Michaelis-Menten constant (K(m)) of the free form were significantly changed after immobilization. The K(m) value for immobilized L-asparaginase was about 1.3 times higher than that of free enzyme. The ions K+, Ba2+ and Na+ showed stimulatory effect on enzyme activity with percentages of 110%, 109% and 106% respectively.

Evaluation of Exhaust Emissions from Three Diesel-Hybrid Cars and Simulation of After-Treatment Systems for Ultralow Real-World NOx Emissions.

PubMed

Franco, Vicente; Zacharopoulou, Theodora; Hammer, Jan; Schmidt, Helge; Mock, Peter; Weiss, Martin; Samaras, Zissis

2016-12-06

Hybridization offers great potential for decreasing pollutant and carbon dioxide emissions of diesel cars. However, an assessment of the real-world emissions performance of modern diesel hybrids is missing. Here, we test three diesel-hybrid cars on the road and benchmark our findings with two cars against tests on the chassis dynamometer and model simulations. The pollutant emissions of the two cars tested on the chassis dynamometer were in compliance with the relevant Euro standards over the New European Driving Cycle and Worldwide harmonized Light vehicles Test Procedure. On the road, all three diesel-hybrids exceeded the regulatory NO x limits (average exceedance for all trips: +150% for the Volvo, +510% for the Peugeot, and +550% for the Mercedes-Benz) and also showed elevated on-road CO 2 emissions (average exceedance of certification values: +178, +77, and +52%, respectively). These findings point to a wide discrepancy between certified and on-road CO 2 and suggest that hybridization alone is insufficient to achieve low-NO x emissions of diesel powertrains. Instead, our simulation suggests that properly calibrated selective catalytic reduction filter and lean-NO x trap after-treatment technologies can reduce the on-road NO x emissions to 0.023 and 0.068 g/km on average, respectively, well below the Euro 6 limit (0.080 g/km).

Geoelectric hazard maps for the continental United States

NASA Astrophysics Data System (ADS)

Love, Jeffrey J.; Pulkkinen, Antti; Bedrosian, Paul A.; Jonas, Seth; Kelbert, Anna; Rigler, E. Joshua; Finn, Carol A.; Balch, Christopher C.; Rutledge, Robert; Waggel, Richard M.; Sabata, Andrew T.; Kozyra, Janet U.; Black, Carrie E.

2016-09-01

In support of a multiagency project for assessing induction hazards, we present maps of extreme-value geoelectric amplitudes over about half of the continental United States. These maps are constructed using a parameterization of induction: estimates of Earth surface impedance, obtained at discrete geographic sites from magnetotelluric survey data, are convolved with latitude-dependent statistical maps of extreme-value geomagnetic activity, obtained from decades of magnetic observatory data. Geoelectric amplitudes are estimated for geomagnetic waveforms having 240 s sinusoidal period and amplitudes over 10 min that exceed a once-per-century threshold. As a result of the combination of geographic differences in geomagnetic activity and Earth surface impedance, once-per-century geoelectric amplitudes span more than 2 orders of magnitude and are an intricate function of location. For north-south induction, once-per-century geoelectric amplitudes across large parts of the United States have a median value of 0.26 V/km; for east-west geomagnetic variation the median value is 0.23 V/km. At some locations, once-per-century geoelectric amplitudes exceed 3 V/km.

Geoelectric hazard maps for the continental United States

USGS Publications Warehouse

Love, Jeffrey J.; Pulkkinen, Antti; Bedrosian, Paul A.; Jonas, Seth; Kelbert, Anna; Rigler, Erin (Josh); Finn, Carol; Balch, Christopher; Rutledge, Robert; Waggel, Richard; Sabata, Andrew; Kozyra, Janet; Black, Carrie

2016-01-01

In support of a multiagency project for assessing induction hazards, we present maps of extreme-value geoelectric amplitudes over about half of the continental United States. These maps are constructed using a parameterization of induction: estimates of Earth surface impedance, obtained at discrete geographic sites from magnetotelluric survey data, are convolved with latitude-dependent statistical maps of extreme-value geomagnetic activity, obtained from decades of magnetic observatory data. Geoelectric amplitudes are estimated for geomagnetic waveforms having 240 s sinusoidal period and amplitudes over 10 min that exceed a once-per-century threshold. As a result of the combination of geographic differences in geomagnetic activity and Earth surface impedance, once-per-century geoelectric amplitudes span more than 2 orders of magnitude and are an intricate function of location. For north-south induction, once-per-century geoelectric amplitudes across large parts of the United States have a median value of 0.26 V/km; for east-west geomagnetic variation the median value is 0.23 V/km. At some locations, once-per-century geoelectric amplitudes exceed 3 V/km.

Status and trends in atmospheric deposition and emissions near Atlanta, Georgia, 1986-99

USGS Publications Warehouse

Peters, N.E.; Meyers, T.P.; Aulenbach, Brent T.

2002-01-01

Wet and dry atmospheric deposition were investigated from weekly data, 1986-99 (1986-97 for dry deposition) at the Panola Mountain Research Watershed (PMRW), a forested research site 25 km, southeast of Atlanta, Georgia. Furthermore, the wet deposition was compared to that at three adjacent National Atmospheric Deposition Program's National Trends Network (NTN) sites (GA41, 50 km south of PMRW; AL99, 175 km northwest; NC25, 175 km north-northeast) and dry deposition was compared to that at adjacent Clean Air Status and Trends Network (CASTNET) sites, co-located at the NTN sites. The pH of precipitation is acidic and the dominant acid anion is SO4; the pH (derived from the volume-weighted mean H concentration) averages 4.44 for 1986-99, and varies seasonally with average lowest values in summer (4.19) and highest in winter (4.63). From 1986-99, the annual wet deposition of sulfur (S) and nitrogen (N) averaged 400 and 300 eq ha-1 (6.4 and 4.2 kg ha-1), respectively. Inferential model estimates of annual dry S and N deposition from 1986-97 averaged 130 and 150 eq ha-1 (2.1 and 2.1 kg ha-1), respectively. From 1993-99, net S deposition (dry deposition plus canopy interactions) for coniferous and deciduous throughfall (throughfall minus wet-only deposition) averaged 400 and 150 eq ha-1 (6.4 and 2.1 kg ha-1), respectively. The annual wet deposition of S and N species at PMRW was comparable to that at NTN sites, with the exception of higher N species deposition at AL99 and relatively lower H, SO4 and NO3 deposition at GA41. Dry S deposition at PMRW differed markedly from the CASTNET sites despite similarity in S concentrations for all but NC25; the differences are attributed to differences in model parameters associated with the landscape and vegetation characteristics at the sites. At PMRW, atmospheric deposition trends were not detected for the entire sampling period, but were detected for shorter periods (4-5yr). Annual S and N deposition increased from 1986 to 1991, decreased to 1995 and then increased to 1999. SO2 emissions from seven major point sources within 120 km of PMRW decreased markedly from the late 1980s to 1995 and have remained relatively constant or increased slightly from 1995 to 1998 Annual wet and dry S deposition at PMRW significantly correlates (p < 0.01) with SO2 emissions, and the correlation is dominated by the large SO2 emissions decreases in the early 1990s, consistent with the implementation of Phase I of Title IV of the 1990 Clean Air Act Amendments.

Undergraduate Research Program in Atmospheric Science: Houston Ozone Studies

NASA Astrophysics Data System (ADS)

Morris, P. A.; Balimuttajjo, M.; Damon, D.; Herridge, A.; Hromis, A. G.; Litwin, D.; Wright, J. M.

2011-12-01

The Minority University Consortium for Earth and Space Sciences (MUCESS) composed of the University of Houston-Downtown (UHD), Medgar Evers College (City University of New York), South Carolina State University, is an undergraduate atmospheric science program funded by NSF. The program's goal is to increase the participation of minority universities in STEM activities and careers by providing students with the knowledge and skills needed to perform weather balloon launches, interpret ozone and temperature variations in the troposphere and stratosphere. Ozone profiles up to 30 km altitude are obtained via an instrument payload attached to a weather balloon. The payload instrumentation consists of an EN-SCI ECC ozonesonde and an iMET radiosonde. The data is transmitted to a base station in real time and includes pressure, temperature, humidity, and GPS coordinates This presentation is directed towards comparing our 2011 Houston data to data that either UHD or the University of Houston (UH) has collected. Our launches are primarily on Sunday, and UH's on Friday. Our primary objective is to identify ground level ozone variations on Sunday and compare with weekday levels as tropospheric ozone is largely controlled by anthropogenic activities. Ozone levels vary depending on the time of year, temperature, rain, wind direction, chemical plant activities, private and commercial traffic patterns.etc. Our limited Friday launches, supported by UH data, indicate that ground level ozone is generally elevated in contrast to Sunday data, For example, our Friday July 2011 launch detected elevated low-altitude ozone levels with ground level ozone levels of 42 nb that increased to 46 nb from 500 m to 1 km. Other peaks are at 2.7 km (44 nb) and 6km (41 nb), decreasing to 17 nb at the tropopause (12 km). Overall, Sunday low altitude ozone levels are generally lower. Our Sunday ground level ozone data ranges from a low of 25 nb on July 11 to a high of 50 nb on August 1. A combination of wind direction and industrial output variations are likely responsible for the these differences. On July 11, ozone levels decrease slightly from the ground-level values up to 2 km. Above this altitude, significant fluctuations in ozone values ranging from 20 to 40nb occur from 2 to 7 km. These fluctuations inversely correlate with humidity. Relative humidity of 20% corresponding to high ozone and 60% humidity values for low ozone. This probably reflects dilution of ozone with water vapor. In contrast, on August 1 ozone values decrease abruptly at 800 meters to 35 nb with only minor fluctuations with increasing altitude to the tropopause. For both days, the change from ground-level ozone values to the higher altitude patterns correlates with a slight temperature inversion. The Stratospheric ozone also shows a significant contrast on the two days. At 22 km altitude an ozone value of 150 nb is seen on August 1 cf the more typical 110 nb on July 11. The high value seen on August 1 is coincident with a major solar flare. These variations are typical of the range of stratospheric ozone levels seen throughout the year and may be attributable to short-term fluctuations in solar activity.

Velocity distribution of women's 30-km cross-country skiing during Olympic Games from 2002-2014.

PubMed

Erdmann, Wlodzimierz S; Dancewicz-Nosko, Dorota; Giovanis, Vasilios

2017-12-01

Within several investigated endurance sport disciplines the distribution of load of the best competitors has a manner of evenly or slightly rising velocity values. Unfortunately many other competitors have usually diminishing values or when they are very poor they have evenly values. The aim of this study was to investigate distribution of velocity within 30-km cross-country female skiers. Cross-country skiing runs were investigated of Olympic Games 2002-2014 (Salt Lake City, Turin, Vancouver, Sochi). At every race two 15 km or three 10 km loops of the same vertical profile were taken into account. The competitors were divided onto: A - winners, B - medallists, C - competitors who obtained places 4 to 10 at the finish line (medium runners), D - competitors who obtained places 11 to 30 at the finish line (poor runners). Velocity data presented on the web pages of several institutions were utilized. The competitors had their velocity distributed in a manner with usually diminishing values. While comparing velocity of sequential loops with the mean velocity the difference for the poor runners reached the value of almost 6 %, which was too high. There was significant (usually negative) correlation coefficient between values of velocity deviation for the first and second loops and the mean value of velocity for the entire distance for the better runners and mixed, i.e. positive and negative values for the poorer runners. It was postulated investigations of velocity distribution should be introduced in coaching in order to inform competitors about their running. This advise is especially important for the poorer runners. Up to now cross country skiers run for themselves. It should be discussed whether the tactics used by road and track runners, i.e. running with pace makers, can be introduced in cross country skiing. Also the use of a drone during training can be used in order to maintain proper pace.

Ozone profile measurements of McMurdo Station, Antarctica, during the spring of 1987

NASA Technical Reports Server (NTRS)

Hofmann, D. J.; Harder, J. W.; Rosen, J. M.; Hereford, J. V.; Carpenter, J. R.

1989-01-01

Ozone and temperature profiles were measured in 50 balloon flights at McMurdo Station (78 deg S) during the spring of 1987. Compared to similar data obtained in 1986, stratospheric temperatures were lower and the spring time Antarctic ozone reduction was greater in magnitude, extended to higher altitude, and proceeded at a higher rate in 1987. Ozone partial pressures reached values as low as 3 nbar (as compared to about 10 nbar in 1986) in the 16- to 18-km region in early and late October, down from about 150 nbar in late August. These low values suggest essentially complete removal of ozone in this region. The upper boundary of the depletion region was observed to be 2-3 km higher than in 1986, extending to altitudes as high as 24 km in mid-September. When averaged over September, the ozone mixing ratio at 18 km decayed with a half-life of only 12.4 days, as compared to about 28 days in 1986. Adiabatic vertical motions over 1- to 2-km intervals between 12 and 20 km with consequent ozone reductions were observed in association with the formation of nacreous clouds, indicating these to be rare events on a local scale probably associated with mountain lee waves.

How Well do State-of-the-Art Techniques Measuring the Vertical Profile of Tropospheric Aerosol Extinction Compare?

NASA Technical Reports Server (NTRS)

Schmid, B.; Ferrare, R.; Flynn, C.; Elleman, R.; Covert, D.; Strawa, A.; Welton, E.; Turner, D.; Jonsson, H.; Redemann, J.;

VizieR Online Data Catalog: RAVE open cluster pairs, groups and complexes (Conrad+, 2017)

NASA Astrophysics Data System (ADS)

Conrad, C.; Scholz, R.-D.; Kharchenko, N. V.; Piskunov, A. E.; Roeser, S.; Schilbach, E.; de Jong, R. S.; Schnurr, O.; Steinmetz, M.; Grebel, E. K.; Zwitter, T.; Bienayme, O.; Bland-Hawthorn, J.; Gibson, B. K.; Gilmore, G.; Kordopatis, G.; Kunder, A.; Navarro, J. F.; Parker, Q.; Reid, W.; Seabroke, G.; Siviero, A.; Watson, F.; Wyse, R.

2017-01-01

The presented tables summarize the parameters for the clusters and the mean values for the detected potential cluster groupings. The ages, distances and proper motions were taken from the Catalogue of Open Cluster Data (COCD; Kharchenko et al. 2005, Cat. J/A+A/438/1163, J/A+A/440/403), while additional radial velocities and metallicities were obtained from the Radial Velocity Experiment (RAVE; Kordopatis et al. 2013AJ....146..134K, Cat. III/272 ) and from the online compilation provided by Dias et al. (2002, See B/ocl). A description of the determination for the radial velocities and metallicities can be found in Conrad et al. 2014A&A...562A..54C. The potential groupings were identified using an adapted Friends-of-Friends algorithm with two sets of linking lengths, namely (100pc, 10km/s) and (100pc, 20km/s). The table clupar.dat (combining Tables A.1 and A.2 from the Appendix of our paper): Tables comprises the parameters collected for the final working sample of 432 clusters with available radial velocities, namely coordinates and proper motions in equatorial and galactic coordinates, distances, ages, metallicities, as well as Cartesian coordinates and velocities. The latter were computed through converting the spherical parameters to Cartesian space with the sun as point of origin. The tables grpar10.dat and grpar20.dat (listed as two parts in Table B.1 of the Appendix of our paper) contain the mean values for the identified potential open cluster groupings for two sets of linking lengths, 100pc and 10km/s (19 potential groupings) and 100pc and 20km/s (41 potential groupings), respectively. These were computed as simple mean, while the uncertainties were computed as simple rms. We list the counting number, the number of members, the COCD number and name for each member, The mean Cartesian coordinates and velocities, along with the uncertainties, the mean distances (with uncertainties), the mean logarithmic ages (with uncertainties) and the mean metallicities, where available (with uncertainties, if at least two measurement were used). (4 data files).

The scale of hydrothermal circulation of the Iheya-North field inferred from intensive heat flow measurements and ocean drilling

NASA Astrophysics Data System (ADS)

Masaki, Y.; Kinoshita, M.; Yamamoto, H.; Nakajima, R.; Kumagai, H.; Takai, K.

2014-12-01

Iheya-North hydrothermal field situated in the middle Okinawa trough backarc basin is one of the largest ongoing Kuroko deposits in the world. Active chimneys as well as diffuse ventings (maximum fluid temperature 311 °C) have been located and studied in detail through various geological and geophysical surveys. To clarify the spatial scale of the hydrothermal circulation system, intensive heat flow measurements were carried out and ~100 heat flow data in and around the field from 2002 to 2014. In 2010, Integrated Ocean Drilling Program (IODP) Expedition 331 was carried out, and subbottom temperature data were obtained around the hydrothermal sites. During the JAMSTEC R/V Kaiyo cruise, KY14-01 in 2014, Iheya-North "Natsu" and "Aki" hydrothermal fields were newly found. The Iheya-Noth "Natsu" and "Aki" sites are located 1.2 km and 2.6 km south from the Iheya-North original site, respectively, and the maximum venting fluid temperature was 317 °C. We obtained one heat flow data at the "Aki" site. The value was 17 W/m2. Currently, the relationship between these hydrothermal sites are not well known. Three distinct zones are identified by heat flow values within 3 km from the active hydrothermal field. They are high-heat flow zone (>1 W/m2; HHZ), moderate-heat-flow zone (1-0.1 W/m2; MHZ); and low-heat-flow zone (<0.1 W/m2; LHZ). With increasing distance east of the HHZ, heat flow gradually decreases towards MHZ and LHZ. In the LHZ, temperature at 37m below the seafloor (mbsf) was 6 °C, that is consistent with the surface low heat flow suggesting the recharge of seawater. However, between 70 and 90 mbsf, the coarser sediments were cored, and temperature increased from 25 °C to 40°C. The temperature was 905°C at 151 mbsf, which was measured with thermoseal strips. The low thermal gradient in the upper 40 m suggests downward fluid flow. We infer that a hydrothermal circulation in the scale of ~1.5 km horizontal vs. ~a few hundred meters vertical.

Three Dimensional P-Wave Velocity Structure Beneath Eastern Turkey by Local Earthquake Tomography (LET) Method

NASA Astrophysics Data System (ADS)

Teoman, U. M.; Turkelli, N.; Gok, R.

2005-12-01

Recently, crustal structure and the tectonic evolution of Eastern Turkey region was extensively studied in the context of Eastern Turkey Seismic Experiment (ETSE) from late 1999 to August 2001. Collision of the Arabian and Eurasian plates has been occurring along East Anatolian Fault Zone (EAFZ) and the Bitlis Suture, which made Eastern Turkey an ideal platform for scientific research. High quality local earthquake data from the ETSE seismic network were used in order to determine the 3-D P-wave velocity structure of upper crust for Eastern Turkey. Within the 32-station network, 524 well locatable earthquakes with azimuthal gaps < 200° and number of P-wave observations > 8 (corresponding to 6842 P-phase readings) were selected from the initial data set and simultaneously inverted. 1-D reference velocity model was derived by an iterative 1-D velocity inversion including the updated hypocenters and the station delays. The following 3-D tomographic inversion was iteratively performed by SIMULPS14 algorithm in a ``damped least-squares'' sense using the appropriate ray tracing technique, model parametrization and control parameters. As far as resolution is concerned, S waves were not included in this study due to strong attenuation, insufficient number of S phase readings and higher picking errors with respect to P phases. Several tests with the synthetic data were conducted to assess the solution quality, suggesting that the velocity structure is well resolved down to ~17km. Overall,resulting 3-D P-wave velocity model led to a more reliable hypocenter determination indicated by reduced event scattering and a significant reduction of %50 both in variance and residual (rms) values.With the influence of improved velocity model, average location errors did not exceed ~1.5km in horizontal and ~4km in vertical directions. Tomographic images revealed the presence of lateral velocity variations in Eastern Turkey. Existence of relatively low velocity zones (5.6 < Vp < 6.0 km/sec) along most of the vertical profiles possibly indicates the influence of major tectonic structures such as North Anatolian Fault Zone (NAFZ), East Anatolian Fault Zone (EAFZ) and the Bitlis thrust belt correlated with the seismicity. Low velocity anomalies extend deeper along EAFZ down to ~15km compared to a depth of ~10km along NAFZ. Arabian plate is generally marked by relatively higher velocities (Vp > 6.2 km/sec) in 10-15 km depth range.

Phytoremediation of Cadmium by Native Plants Grown on Mining Soil.

PubMed

Palutoglu, Mahmut; Akgul, Bunyamin; Suyarko, Vasily; Yakovenko, Myroslava; Kryuchenko, Nataliya; Sasmaz, Ahmet

2018-02-01

The Gümüsköy mining area is located about 25 km west of Kutahya and is the largest silver deposit in Turkey. The present study investigated translocation and accumulation of cadmium (Cd) from the soil into 11 native plants. Plant and soil samples were collected from the field, and Cd concentrations were analyzed by inductively coupled plasma mass spectroscopy. Mean Cd values in the soil, root, and shoot of native plants in the study area were 82.8 ± 5, 55.4 ± 6, and 43.5 ± 4 mg kg - 1 , respectively. Plants were separated into several groups according to the enrichment coefficients for shoot and root values of plants. These groups showed Carduus nutans and Phlomis could be potentially bioaccumulator plants useful for phytoremediation of mining soils contaminated by Cd.

Nitric oxide concentration near the mesopause as deduced from ionospheric absorption measurements

NASA Astrophysics Data System (ADS)

Lastovicka, J.

The upper-D-region NO concentration is calculated on the basis of published 2775-kHz-absorption, Lyman-alpha (OSO-5), and X-ray (Solrad-9) data obtained over Central Europe in June-August 1969, 1970, and 1972. Ionization-rate and radio-wave-absorption profiles for solar zenith angles of 60, 70 and 40 deg are computed, presented graphically, and compared with model calculations to derive the NO-concentration correction coefficients necessary to make the Lyman-alpha/X-ray flux ratios of the models of Meira (1971), Baker et al. (1977), Tohmatsu and Iwagami (1976), and Tisone (1973) agree with the observed ratios. Values of the corrected NO concentration include 6.5 and 8.5 x 10 to the 13th/cu m at 78 and 90 km, respectively. The values are shown to be higher than those of standard models but within the range of observed concentrations.

Depth dependent stress revealed by aftershocks

NASA Astrophysics Data System (ADS)

Narteau, C.; Shebalin, P.

2017-12-01

Aftershocks occur in response to perturbations of the state of stress induced either by earthquakes or human activities. Along major strike-slip fault segments of the San Andreas fault system, the time-delay before the onset of the power-law aftershock decay rate (the c-value) varies by three orders of magnitude in the first twenty kilometers below the surface. Despite the influence of the lithostatic stress, there is no continuous change in c-value with respect to depth. Instead, two decay phases are separated by an abrupt increase at an intermediate depth range of 2 to 5 km. This transitional regime is the only one observed in fluid-injection-induced seismic areas. This provides strong evidence for the role of fluid and a porosity reduction mechanism at depth of few kilometers in active fault zones. Aftershock statistics can then be used to predict the evolution the differential shear stress with depth until the brittle-ductile transition is reached.

Retrieval of O2(1Σ) and O2(1Δ) volume emission rates in the mesosphere and lower thermosphere using SCIAMACHY MLT limb scans

NASA Astrophysics Data System (ADS)

Zarboo, Amirmahdi; Bender, Stefan; Burrows, John P.; Orphal, Johannes; Sinnhuber, Miriam

2018-01-01

We present the retrieved volume emission rates (VERs) from the airglow of both the daytime and twilight O2(1Σ) band and O2(1Δ) band emissions in the mesosphere and lower thermosphere (MLT). The SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) onboard the European Space Agency Envisat satellite observes upwelling radiances in limb-viewing geometry during its special MLT mode over the range 50-150 km. In this study we use the limb observations in the visible (595-811 nm) and near-infrared (1200-1360 nm) bands. We have investigated the daily mean latitudinal distributions and the time series of the retrieved VER in the altitude range from 53 to 149 km. The maximal observed VERs of O2(1Δ) during daytime are typically 1 to 2 orders of magnitude larger than those of O2(1Σ). The latter peaks at around 90 km, whereas the O2(1Δ) emissivity decreases with altitude, with the largest values at the lower edge of the observations (about 53 km). The VER values in the upper mesosphere (above 80 km) are found to depend on the position of the sun, with pronounced high values occurring during summer for O2(1Δ). O2(1Σ) emissions show additional high values at polar latitudes during winter and spring. These additional high values are presumably related to the downwelling of atomic oxygen after large sudden stratospheric warmings (SSWs). Accurate measurements of the O2(1Σ) and O2(1Δ) airglow, provided that the mechanism of their production is understood, yield valuable information about both the chemistry and dynamics in the MLT. For example, they can be used to infer the amounts and distribution of ozone, solar heating rates, and temperature in the MLT.

Preliminary study of crust-upper mantle structure of the Tibetan Plateau by using broadband teleseismic body waveforms

NASA Astrophysics Data System (ADS)

Zhu, Lu-Pei; Zeng, Rong-Sheng; Wu, Francis T.; Owens, Thomas J.; Randall, George E.

1993-05-01

As part of a joint Sino-U.S. research project to study the deep structure of the Tibetan Plateau, 11 broadband digital seismic recorders were deployed on the Plateau for one year of passive seismic recording. In this report we use teleseimic P waveforms to study the seismic velocity structure of crust and upper mantle under three stations by receiver function inversion. The receiver function is obtained by first rotating two horizontal components of seismic records into radial and tangential components and then deconvolving the vertical component from them. The receiver function depends only on the structure near the station because the source and path effects have been removed by the deconvolution. To suppress noise, receiver functions calculated from events clustered in a small range of back-azimuths and epicentral distances are stacked. Using a matrix formalism describing the propagation of elastic waves in laterally homogeneous stratified medium, a synthetic receiver function and differential receiver functions for the parameters in each layer can be calculated to establish a linearized inversion for one-dimensional velocity structure. Preliminary results of three stations, Wen-quan, Golmud and Xigatze (Coded as WNDO, TUNL and XIGA), located in central, northern and southern Plateau are given in this paper. The receiver functions of all three stations show clear P-S converted phases. The time delays of these converted phases relative to direct P arrivals are: WNDO 7.9s (for NE direction) and 8.3s (for SE direction), TUNL 8.2s, XIGA 9.0s. Such long time delays indicate the great thickness of crust under the Plateau. The differences between receiver function of these three station shows the tectonic difference between southern and north-central Plateau. The waveforms of the receiver functions for WNDO and TUNL are very simple, while the receiver function of XIGA has an additional midcrustal converted phase. The S wave velocity structures at these three stations are estimated from inversions of the receiver function. The crustal shear wave velocities at WNDO and TUNL are vertically homogeneous, with value between 3.5 3.6 km/s down to Moho. This value in the lower crust is lower than the normal value for the lower crust of continents, which is consistent with the observed strong Sn attenuation in this region. The velocity structure at XIGA shows a velocity discontinuity at depth of 20 km and high velocity value of 4.0 km/s in the midcrust between 20 30 km depth. Similar results are obtained from a DSS profile in southern Tibet. The velocity under XIGA decreases below a depth of 30 km, reaching the lowest value of 3.2 km/s between 50 55 km. depth. This may imply that the Indian crust underthrusts the low part of Tibetan crust in the southern Plateau, forming a “double crust”. The crustal thickness at each of these sites is: WNDO, 68 km; TUNL, 70 km; XI-GA, 80 km.

Statistical characterization of high-to-medium frequency mesoscale gravity waves by lidar-measured vertical winds and temperatures in the MLT

NASA Astrophysics Data System (ADS)

Lu, Xian; Chu, Xinzhao; Li, Haoyu; Chen, Cao; Smith, John A.; Vadas, Sharon L.

2017-09-01

We present the first statistical study of gravity waves with periods of 0.3-2.5 h that are persistent and dominant in the vertical winds measured with the University of Colorado STAR Na Doppler lidar in Boulder, CO (40.1°N, 105.2°W). The probability density functions of the wave amplitudes in temperature and vertical wind, ratios of these two amplitudes, phase differences between them, and vertical wavelengths are derived directly from the observations. The intrinsic period and horizontal wavelength of each wave are inferred from its vertical wavelength, amplitude ratio, and a designated eddy viscosity by applying the gravity wave polarization and dispersion relations. The amplitude ratios are positively correlated with the ground-based periods with a coefficient of 0.76. The phase differences between the vertical winds and temperatures (φW -φT) follow a Gaussian distribution with 84.2±26.7°, which has a much larger standard deviation than that predicted for non-dissipative waves ( 3.3°). The deviations of the observed phase differences from their predicted values for non-dissipative waves may indicate wave dissipation. The shorter-vertical-wavelength waves tend to have larger phase difference deviations, implying that the dissipative effects are more significant for shorter waves. The majority of these waves have the vertical wavelengths ranging from 5 to 40 km with a mean and standard deviation of 18.6 and 7.2 km, respectively. For waves with similar periods, multiple peaks in the vertical wavelengths are identified frequently and the ones peaking in the vertical wind are statistically longer than those peaking in the temperature. The horizontal wavelengths range mostly from 50 to 500 km with a mean and median of 180 and 125 km, respectively. Therefore, these waves are mesoscale waves with high-to-medium frequencies. Since they have recently become resolvable in high-resolution general circulation models (GCMs), this statistical study provides an important and timely reference for them.

Assessing Controls on the Geometry and Dimensions of Modern Barrier Islands

NASA Astrophysics Data System (ADS)

Mulhern, J.; Johnson, C. L.; Martin, J. M.

2015-12-01

Barrier islands are highly ephemeral features, shaped by wave, tide, and storm energy. The processes that govern the size, shape, and motion of barrier islands are not well constrained, yet central to coastal dynamics. While the global distribution of barrier islands has been mapped and assessed, there is little consensus on the forces controlling barrier island formation, motion, or preservation. This study presents a new semi-global database of modern barrier islands to better understand their morphology and spatial distribution. We have mapped, in Google Earth, the subaerial extent of >350 barrier islands and spits, measuring spatial characteristic such as exposed area, perimeter, length, and width. These objects are cross-referenced with parameters that potentially control morphology, including tidal range, wave height, climate, distance from the continental shelf, proximity to fluvial output, and tectonic setting. This approach provides a more optimal framework to assess controls on coastal features, including barrier island morphology, and to investigate potential geometric scaling relationships. Preliminary analysis shows trends in the spatial characteristics of barrier islands. There is a strong linear relationship between the perimeter and length (y= -0.59 + 0.42x, R2=0.95). Linear trends also relate length to area when the data are separated by tidal range to wave height ratio. Assessment of barrier island shape supports the hypothesis of Hayes (1979) that barrier islands in wave-dominated settings are long and linear while those in mixed energy setting are more rounded. The barrier islands of the Texas Gulf of Mexico are larger than the global average for the database, with distinctly longer length values (41.16 km vs. 15.77 km respectively) and larger areas (103.81 km2 vs. 42.14 km2 respectively). Initial assessment shows that tidal range and wave height are primary controls barrier island dimensions. Future work will consider climate, latitude, fluvial input, and tectonic regime as additional factors. Assessing modern barrier islands will lend insight into potential paleomorphodynamic relationships and help determine how islands are transferred into the rock record, with implications for sequence stratigraphy, subsurface reservoirs, etc.

High-performance thermoelectric minerals: Colusites Cu26V2M6S32 (M = Ge, Sn)

NASA Astrophysics Data System (ADS)

Suekuni, Koichiro; Kim, Fiseong S.; Nishiate, Hirotaka; Ohta, Michihiro; Tanaka, Hiromi I.; Takabatake, Toshiro

2014-09-01

We report thermoelectric (TE) properties of dense samples of colusites Cu26V2M6S32 (M = Ge, Sn), most of which are composed of earth-abundant elements; Cu and S. The combination of p-type metallic conduction and large thermopowers greater than 200 μV/K leads to high TE power factors of 0.61 and 0.48 mW/K2 m at 663 K for M = Ge and Sn samples, respectively. Furthermore, the lattice thermal conductivity is smaller than 0.6 W/Km over the temperature range from 350 K to 663 K due to the structural complexity. As a consequence, the values of dimensionless TE figure of merit ZT for M = Ge and Sn reach 0.73 and 0.56 at 663 K, respectively. Thus, the colusites are promising candidates for environmental friendly TE materials usable in the range of 500-700 K.

Spectral analysis of the gravity and topography of Mars

NASA Technical Reports Server (NTRS)

Bills, Bruce G.; Frey, Herbert V.; Kiefer, Walter S.; Nerem, R. Steven; Zuber, Maria T.

1993-01-01

New spherical harmonic models of the gravity and topography of Mars place important constraints on the structure and dynamics of the interior. The gravity and topography models are significantly phase coherent for harmonic degrees n less than 30 (wavelengths greater than 700 km). Loss of coherence below that wavelength is presumably due to inadequacies of the models, rather than a change in behavior of the planet. The gravity/topography admittance reveals two very different spectral domains: for n greater than 4, a simple Airy compensation model, with mean depth of 100 km, faithfully represents the observed pattern; for degrees 2 and 3, the effective compensation depths are 1400 and 550 km, respectively, strongly arguing for dynamic compensation at those wavelengths. The gravity model has been derived from a reanalysis of the tracking data for Mariner 9 and the Viking Orbiters, The topography model was derived by harmonic analysis of the USGS digital elevation model of Mars. Before comparing gravity and topography for internal structure inferences, we must ensure that both are consistently referenced to a hydrostatic datum. For the gravity, this involves removal of hydrostatic components of the even degree zonal coefficients. For the topography, it involves adding the degree 4 equipotential reference surface, to get spherically referenced values, and then subtracting the full degree 50 equipotential. Variance spectra and phase coherence of orthometric heights and gravity anomalies are addressed.

Hemispheric Dichotomy in Lithosphere Thickness on Mars Caused by Differences in Crustal Structure and Composition

NASA Astrophysics Data System (ADS)

Thiriet, Mélanie; Michaut, Chloé; Breuer, Doris; Plesa, Ana-Catalina

2018-04-01

Estimates of the Martian elastic lithosphere thickness suggest small values of ˜25 km during the Noachian for the southern hemisphere and a large present-day difference below the two polar caps (≥300 km in the north and >110 km in the south). In addition, young lava flows suggest that Mars has been volcanically active up to the recent past. We run Monte Carlo simulations using a 1-D parameterized thermal evolution model to investigate whether a north/south hemispheric dichotomy in crustal properties and composition can explain these constraints. Our results suggest that 55-65% of the bulk radioelement content are in the crust, and most of it (43-51%) in the southern one. The southern crust can be up to 480 kg/m3 less dense than the northern one and might contain a nonnegligible proportion of felsic rocks. Our models predict a dry mantle and a wet or dry crustal rheology today. This is consistent with a mantle depleted in radioelements and volatiles. We retrieve north/south surface heat flux of 17.1-19.5 mW/m2 and 24.8-26.5 mW/m2, respectively, and a large difference in lithospheric temperatures between the two hemispheres (170-304 K in the shallow mantle). This difference could leave a signature in the seismic signals measured by the future InSight mission.

Characteristics and mechanism of deep mesoscale variability south of the Kuroshio Extension

NASA Astrophysics Data System (ADS)

Miyamoto, Masatoshi; Oka, Eitarou; Yanagimoto, Daigo; Fujio, Shinzou; Mizuta, Genta; Imawaki, Shiro; Kurogi, Masao; Hasumi, Hiroyasu

2017-05-01

To clarify the characteristics and mechanism of mesoscale variability in the deep ocean, we analyzed historical mooring observations conducted at Site R (30°N, 147°E) south of the Kuroshio Extension during 1978-85 and the 10-year output of an eddy-resolving ocean general circulation model. The power spectral density (PSD) of current velocity at a depth of 5000 m had a peak at periods of 45-75 days at two mooring stations that were zonally 98 km apart and at 54 days at Site R in the model. In the model, the PSD at 54 days at 5000 m had a horizontal maximum 100 km north of Site R as well as in the Kuroshio Extension region 500 km north of Site R. Within the high-PSD region near Site R, variability in the velocity was coherent, and its phase propagation was characterized by zonal and meridional wavenumbers of -2.9×10-5 and 0.1×10-5 rad m-1, respectively, the former of which was comparable to the value of -2.6×10-5 rad m-1 obtained from the mooring observations. Such wavenumbers matched well with the dispersion relation of barotropic topographic Rossby waves (TRWs). Backward ray tracing and PSD distribution suggested that the barotropic TRWs at Site R were generated in the Kuroshio Extension region, and their energy propagated southward.

Spatial Distribution of Conventional Air Pollutant and GHGs from Land Transportation in Two Developing Cities and Main Co-Benefit Actions For Reducing It.

NASA Astrophysics Data System (ADS)

Huboyo, Haryono S.; Sutrisno, Endro; Sutrisno, Ana M.; Tiarani, Velida L.

2018-02-01

Surakarta and Yogyakarta are the emerging cities which now struggle to manage its pollution from transport sector. This study aims to calculate the emission, to describe spatial distribution and to analyze existing co-benefit actions related to land transportation in Surakarta and Yogyakarta in 2015. The main method used for this analysis comes from Ministry of Environment and Forestry. The VKT values were aggregated for Surakarta city and Yogyakarta city and it showed 27.36 km/day, 37.52 km/day and 27.71 km/day for motorcycle, car and truck respectively. At Surakarta city, the emission load from transport sector in 2014 were 449.95 tons/ year (TSP), 5134 ton/ year(NOx), 243 ton/year (SO2), 50,605 ton /year (CO) and 421,594 tons/year (CO2e). Villages of Kemlayan, Timuran and Keprabon showed the highest emission. While in Yogyakarta city in 2014, the burden of TSP was 58,409 tons/year, NOx was 8,058 tons/year, SO2 was 285.37 ton/year, CO was 75,008 tons/year and CO2e by 601,068 tons/year. The village of Pringgokusuman and Sosromeduran showed the highest emission. Several programs were adopted in Yogyakarta city and Surakarta city for mitigating air pollution i.e ITS-ATCS, BRT system, car free day.

Prediction of the potential geographic distribution of the ectomycorrhizal mushroom Tricholoma matsutake under multiple climate change scenarios.

PubMed

Guo, Yanlong; Li, Xin; Zhao, Zefang; Wei, Haiyan; Gao, Bei; Gu, Wei

2017-04-10

Effective conservation and utilization strategies for natural biological resources require a clear understanding of the geographic distribution of the target species. Tricholoma matsutake is an ectomycorrhizal (ECM) mushroom with high ecological and economic value. In this study, the potential geographic distribution of T. matsutake under current conditions in China was simulated using MaxEnt software based on species presence data and 24 environmental variables. The future distributions of T. matsutake in the 2050s and 2070s were also projected under the RCP 8.5, RCP 6, RCP 4.5 and RCP 2.6 climate change emission scenarios described in the Special Report on Emissions Scenarios (SRES) by the Intergovernmental Panel on Climate Change (IPCC). The areas of marginally suitable, suitable and highly suitable habitats for T. matsutake in China were approximately 0.22 × 10 6  km 2 , 0.14 × 10 6  km 2 , and 0.11 × 10 6  km 2 , respectively. The model simulations indicated that the area of marginally suitable habitats would undergo a relatively small change under all four climate change scenarios; however, suitable habitats would significantly decrease, and highly suitable habitat would nearly disappear. Our results will be influential in the future ecological conservation and management of T. matsutake and can be used as a reference for studies on other ectomycorrhizal mushroom species.

Prediction of the potential geographic distribution of the ectomycorrhizal mushroom Tricholoma matsutake under multiple climate change scenarios

NASA Astrophysics Data System (ADS)

Guo, Yanlong; Li, Xin; Zhao, Zefang; Wei, Haiyan; Gao, Bei; Gu, Wei

2017-04-01

Effective conservation and utilization strategies for natural biological resources require a clear understanding of the geographic distribution of the target species. Tricholoma matsutake is an ectomycorrhizal (ECM) mushroom with high ecological and economic value. In this study, the potential geographic distribution of T. matsutake under current conditions in China was simulated using MaxEnt software based on species presence data and 24 environmental variables. The future distributions of T. matsutake in the 2050s and 2070s were also projected under the RCP 8.5, RCP 6, RCP 4.5 and RCP 2.6 climate change emission scenarios described in the Special Report on Emissions Scenarios (SRES) by the Intergovernmental Panel on Climate Change (IPCC). The areas of marginally suitable, suitable and highly suitable habitats for T. matsutake in China were approximately 0.22 × 106 km2, 0.14 × 106 km2, and 0.11 × 106 km2, respectively. The model simulations indicated that the area of marginally suitable habitats would undergo a relatively small change under all four climate change scenarios; however, suitable habitats would significantly decrease, and highly suitable habitat would nearly disappear. Our results will be influential in the future ecological conservation and management of T. matsutake and can be used as a reference for studies on other ectomycorrhizal mushroom species.

Differential absorption lidar measurements of atmospheric water vapor using a pseudonoise code modulated AlGaAs laser. Thesis

NASA Technical Reports Server (NTRS)

Rall, Jonathan A. R.

1994-01-01

Lidar measurements using pseudonoise code modulated AlGaAs lasers are reported. Horizontal path lidar measurements were made at night to terrestrial targets at ranges of 5 and 13 km with 35 mW of average power and integration times of one second. Cloud and aerosol lidar measurements were made to thin cirrus clouds at 13 km altitude with Rayleigh (molecular) backscatter evident up to 9 km. Average transmitter power was 35 mW and measurement integration time was 20 minutes. An AlGaAs laser was used to characterize spectral properties of water vapor absorption lines at 811.617, 816.024, and 815.769 nm in a multipass absorption cell using derivative spectroscopy techniques. Frequency locking of an AlGaAs laser to a water vapor absorption line was achieved with a laser center frequency stability measured to better than one-fifth of the water vapor Doppler linewidth over several minutes. Differential absorption lidar measurements of atmospheric water vapor were made in both integrated path and range-resolved modes using an externally modulated AlGaAs laser. Mean water vapor number density was estimated from both integrated path and range-resolved DIAL measurements and agreed with measured humidity values to within 6.5 percent and 20 percent, respectively. Error sources were identified and their effects on estimates of water vapor number density calculated.

Influence of weather conditions on the flight of migrating black storks

PubMed Central

Chevallier, D.; Handrich, Y.; Georges, J.-Y.; Baillon, F.; Brossault, P.; Aurouet, A.; Le Maho, Y.; Massemin, S.

2010-01-01

This study tested the potential influence of meteorological parameters (temperature, humidity, wind direction, thermal convection) on different migration characteristics (namely flight speed, altitude and direction and daily distance) in 16 black storks (Ciconia nigra). The birds were tracked by satellite during their entire autumnal and spring migration, from 1998 to 2006. Our data reveal that during their 27-day-long migration between Europe and Africa (mean distance of 4100 km), the periods of maximum flight activity corresponded to periods of maximum thermal energy, underlining the importance of atmospheric thermal convection in the migratory flight of the black stork. In some cases, tailwind was recorded at the same altitude and position as the birds, and was associated with a significant rise in flight speed, but wind often produced a side azimuth along the birds' migratory route. Whatever the season, the distance travelled daily was on average shorter in Europe than in Africa, with values of 200 and 270 km d−1, respectively. The fastest instantaneous flight speeds of up to 112 km h−1 were also observed above Africa. This observation confirms the hypothesis of thermal-dependant flight behaviour, and also reveals differences in flight costs between Europe and Africa. Furthermore, differences in food availability, a crucial factor for black storks during their flight between Europe and Africa, may also contribute to the above-mentioned shift in daily flight speeds. PMID:20427337

Prediction of the potential geographic distribution of the ectomycorrhizal mushroom Tricholoma matsutake under multiple climate change scenarios

PubMed Central

Guo, Yanlong; Li, Xin; Zhao, Zefang; Wei, Haiyan; Gao, Bei; Gu, Wei

2017-01-01

Effective conservation and utilization strategies for natural biological resources require a clear understanding of the geographic distribution of the target species. Tricholoma matsutake is an ectomycorrhizal (ECM) mushroom with high ecological and economic value. In this study, the potential geographic distribution of T. matsutake under current conditions in China was simulated using MaxEnt software based on species presence data and 24 environmental variables. The future distributions of T. matsutake in the 2050s and 2070s were also projected under the RCP 8.5, RCP 6, RCP 4.5 and RCP 2.6 climate change emission scenarios described in the Special Report on Emissions Scenarios (SRES) by the Intergovernmental Panel on Climate Change (IPCC). The areas of marginally suitable, suitable and highly suitable habitats for T. matsutake in China were approximately 0.22 × 106 km2, 0.14 × 106 km2, and 0.11 × 106 km2, respectively. The model simulations indicated that the area of marginally suitable habitats would undergo a relatively small change under all four climate change scenarios; however, suitable habitats would significantly decrease, and highly suitable habitat would nearly disappear. Our results will be influential in the future ecological conservation and management of T. matsutake and can be used as a reference for studies on other ectomycorrhizal mushroom species. PMID:28393865

The effects of river run-off on water clarity across the central Great Barrier Reef.

PubMed

Fabricius, K E; Logan, M; Weeks, S; Brodie, J

2014-07-15

Changes in water clarity across the shallow continental shelf of the central Great Barrier Reef were investigated from ten years of daily river load, oceanographic and MODIS-Aqua data. Mean photic depth (i.e., the depth of 10% of surface irradiance) was related to river loads after statistical removal of wave and tidal effects. Across the ∼25,000 km(2) area, photic depth was strongly related to river freshwater and phosphorus loads (R(2)=0.65 and 0.51, respectively). In the six wetter years, photic depth was reduced by 19.8% and below water quality guidelines for 156 days, compared to 9 days in the drier years. After onset of the seasonal river floods, photic depth was reduced for on average 6-8 months, gradually returning to clearer baseline values. Relationships were strongest inshore and midshelf (∼12-80 km from the coast), and weaker near the chronically turbid coast. The data show that reductions in river loads would measurably improve shelf water clarity, with significant ecosystem health benefits. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Voyager 2 radio science observations of the Uranian system Atmosphere, rings, and satellites

NASA Technical Reports Server (NTRS)

Tyler, G. L.; Eshleman, V. R.; Hinson, D. P.; Marouf, E. A.; Simpson, R. A.; Sweetnam, D. N.; Anderson, J. D.; Campbell, J. K.; Levy, G. S.; Lindal, G. F.

1986-01-01

The results of preliminary analyses of radio occultation data obtained by Voyager 2 as it passed Uranus are described. The occultations took place between 2-7 deg S latitude and yielded atmospheric temperature profiles between pressure levels of 10-900 mbar, an altitude range of 100 km. The mole fractions of hydrogen and helium in the tropopause were estimated, in conjunction with IR data, to about 0.85 and 0.10-0.20, respectively. Radio signal intensity data indicated the presence of a cloud deck of CH4 ice at a pressure level of 1300 mbar and a temperature of 81 K, implying a CH4 mole fraction of 0.02 at very low altitudes. The ionosphere extended upward, in two levels, to more than 10,000 km altitude. The ring system was different than the one around Saturn and possessed cylindrical substructures. The radio data also permitted mass density estimates for the five major moons, i.e., about 1.40 gr/cu cm, a value which rules out cometary origins.

A new digital elevation model of Antarctica derived from CryoSat-2 altimetry

NASA Astrophysics Data System (ADS)

Slater, Thomas; Shepherd, Andrew; McMillan, Malcolm; Muir, Alan; Gilbert, Lin; Hogg, Anna E.; Konrad, Hannes; Parrinello, Tommaso

2018-05-01

We present a new digital elevation model (DEM) of the Antarctic ice sheet and ice shelves based on 2.5 × 108 observations recorded by the CryoSat-2 satellite radar altimeter between July 2010 and July 2016. The DEM is formed from spatio-temporal fits to elevation measurements accumulated within 1, 2, and 5 km grid cells, and is posted at the modal resolution of 1 km. Altogether, 94 % of the grounded ice sheet and 98 % of the floating ice shelves are observed, and the remaining grid cells north of 88° S are interpolated using ordinary kriging. The median and root mean square difference between the DEM and 2.3 × 107 airborne laser altimeter measurements acquired during NASA Operation IceBridge campaigns are -0.30 and 13.50 m, respectively. The DEM uncertainty rises in regions of high slope, especially where elevation measurements were acquired in low-resolution mode; taking this into account, we estimate the average accuracy to be 9.5 m - a value that is comparable to or better than that of other models derived from satellite radar and laser altimetry.

Radiometry with nighttime DMSP images in digital form. [satellite earth observations

NASA Technical Reports Server (NTRS)

Croft, T. A.

1981-01-01

The USAF Defense Meteorological Satellite Program (DMSP) spacecraft sends images to earth in the form of numbers. It has been common practice to erase the only digital records, the magnetic tapes, for reuse, after films (resembling photographs) have been created from the numbers. While the DMSP images have been widely used, their application in research has been hindered by both the lack of digital data and the lack of an authoritative source of related technical information. The character of the digital form is considered. Each image is essentially a three-dimensional list (X,Y,Z) in which X and Y represent the position coordinates of a pixel and Z is its associated radiance. Only the value of Z is given and the X-Y position must be deduced from adjunct information. Each original scan composed of 1464 pixels represents an area on the earth's surface about 3 km wide and 3000 km long. Strengths and weaknesses of the system with respect to research applications are considered, and concepts for the design of a nocturnal imager are discussed.

Finite-fault slip model of the 2011 Mw 5.6 Prague, Oklahoma earthquake from regional waveforms

USGS Publications Warehouse

Sun, Xiaodan; Hartzell, Stephen

2014-01-01

The slip model for the 2011 Mw 5.6 Prague, Oklahoma, earthquake is inferred using a linear least squares methodology. Waveforms of six aftershocks recorded at 21 regional stations are used as empirical Green's functions (EGFs). The solution indicates two large slip patches: one located around the hypocenter with a depth range of 3–5.5 km; the other located to the southwest of the epicenter with a depth range from 7.5 to 9.5 km. The total moment of the solution is estimated at 3.37 × 1024 dyne cm (Mw 5.65). The peak slip and average stress drop for the source at the hypocenter are 70 cm and 90 bars, respectively, approximately one half the values for the Mw 5.8 2011 Mineral, Virginia, earthquake. The stress drop averaged over all areas of slip is 16 bars. The relatively low peak slip and stress drop may indicate an induced component in the origin of the Prague earthquake from deep fluid injection.

Analysis of the perihelic passages of the comet 1P/Halley in 1910 and in 1986

NASA Astrophysics Data System (ADS)

Voelzke, Marcos Rincon

2016-07-01

This work is based on a systematic analysis of images of 1P/Halley comet collected during its penultimate and ultimate approaches, i.e., in 1910 and in 1986. The present research basically characterised, identified, classified, measured and compared some of the tail structures of comet 1P/Halley like DEs, wavy structures and solitons. The images illustrated in the Atlas of Comet Halley 1910 II (Donn et al., 1986), which shows the comet in its 1910 passage, were compared with the images illustrated in The International Halley Watch Atlas of Large-Scale Phenomena (Brandt et al., 1992), which shows the comet in its 1986 passage. While two onsets of DEs were discovered after the perihelion passage in 1910, the average value of the corrected cometocentric velocity Vc was (57 ± 15) km/s; ten were discovered after the perihelion passage in 1986 with an average of corrected velocities equal to (130 ± 37) km/s. The mean value of the corrected wavelength of wavy structures, in 1910, is equal to (1.7 ± 0.1) x 10 ^{6} km and in 1986 is (2.2 ± 0.2) x 10 ^{6} km. The mean value of the amplitude A of the wave, in 1910, is equal to (1.4 ± 0.1) x 10 ^{5} km and in 1986 it is equal to (2.8 ± 0.5) x 10 ^{5} km. The goals of this research are to report the results obtained from the analysis of the P/Halleýs 1910 and 1986 images, to provide empirical data for comparison and to form the input for future physical/theoretical work.

Comparative analysis of images of comet 1P/Halley in their perihelion passages in 1910 and 1986

NASA Astrophysics Data System (ADS)

Voelzke, Marcos Rincon

This work is based on a systematic analysis of images of 1P/Halley comet collected during its penultimate and ultimate approaches, i.e., in 1910 and in 1986. The present research basically characterised, identified, classified, measured and compared some of the tail structures of comet 1P/Halley like DEs, wavy structures and solitons. The images illustrated in the Atlas of Comet Halley 1910 II (Donn et al., 1986), which shows the comet in its 1910 passage, were compared with the images illustrated in The International Halley Watch Atlas of Large-Scale Phenomena (Brandt et al., 1992), which shows the comet in its 1986 passage. While two onsets of DEs were discovered after the perihelion passage in 1910, the average value of the corrected cometocentric velocity Vc was (57 ± 15) km s (-1) ; ten were discovered after the perihelion passage in 1986 with an average of corrected velocities equal to (130 ± 37) km s (-1) .The mean value of the corrected wavelength of wavy structures, in 1910, is equal to (1.7 ± 0.1) x 10 (6) km and in 1986 is (2.2 ± 0.2) x 10 (6) km. The mean value of the amplitude A of the wave, in 1910, is equal to (1.4 ± 0.1) x 10 (5) km and in 1986 it is equal to (2.8 ± 0.5) x 10 (5) km. The goals of this research are to report the results obtained from the analysis of the P/Halleýs 1910 and 1986 images, to provide empirical data for comparison and to form the input for future physical/theoretical work.

Analysis of the morphological structures of comet 1P/Halley in their perihelion passages in 1910 and 1986

NASA Astrophysics Data System (ADS)

Voelzke, Marcos Rincon

2015-08-01

This work is based on a systematic analysis of images of 1P/Halley comet collected during its penultimate and ultimate approaches, i.e., in 1910 and in 1986. The present research basically characterised, identified, classified, measured and compared some of the tail structures of comet 1P/Halley like DEs, wavy structures and solitons. The images illustrated in the Atlas of Comet Halley 1910 II (Donn et al., 1986), which shows the comet in its 1910 passage, were compared with the images illustrated in The International Halley Watch Atlas of Large-Scale Phenomena (Brandt et al., 1992), which shows the comet in its 1986 passage. While two onsets of DEs were discovered after the perihelion passage in 1910, the average value of the corrected cometocentric velocity Vc was (57 ± 15) km/s ; ten were discovered after the perihelion passage in 1986 with an average of corrected velocities equal to (130 ± 37) km/s .The mean value of the corrected wavelength of wavy structures, in 1910, is equal to (1.7 ± 0.1) x 106 km and in 1986 is (2.2 ± 0.2) x 106 km. The mean value of the amplitude A of the wave, in 1910, is equal to (1.4 ± 0.1) x 105 km and in 1986 it is equal to (2.8 ± 0.5) x 105 km. The goals of this research are to report the results obtained from the analysis of the P/Halleýs 1910 and 1986 images, to provide empirical data for comparison and to form the input for future physical/theoretical work.

Genetic and Biochemical Characterization of a Novel Metallo-β-Lactamase, TMB-1, from an Achromobacter xylosoxidans Strain Isolated in Tripoli, Libya

PubMed Central

El Salabi, Allaaeddin; Borra, Pardha Saradhi; Toleman, Mark A.; Samuelsen, Ørjan

2012-01-01

An Achromobacter xylosoxidans strain from the Tripoli central hospital produced a unique metallo-β-lactamase, designated TMB-1, which is related to DIM-1 (62%) and GIM-1 (51%). blaTMB-1 was embedded in a class 1 integron and located on the chromosome. The TMB-1 β-lactamase has lower kcat values than both DIM-1 and GIM-1 with cephalosporins and carbapenems. The Km values were more similar to those of GIM-1 than those of DIM-1, with the overall kcat/Km values being lower than those for GIM-1 and DIM-1. PMID:22290947

Applications of Hybrid Algorithm (Successive Over Relaxation and Inverse Distance Weighting) for Interpolating Rainfall Data Obtained from a Dense Network of Meteorological Stations in Metro Manila, Philippines

NASA Astrophysics Data System (ADS)

Yao, J. G.; Lagrosas, N.; Ampil, L. J. Y.; Lorenzo, G. R. H.; Simpas, J.

2016-12-01

A hybrid piecewise rainfall value interpolation algorithm was formulated using the commonly known Inverse Distance Weighting (IDW) and Gauss-Seidel variant Successive Over Relaxation (SOR) to interpolate rainfall values over Metro Manila, Philippines. Due to the fact that the SOR requires boundary values for its algorithm to work, the IDW method has been used to estimate rainfall values at the boundary. Iterations using SOR were then done on the defined boundaries to obtain the desired results corresponding to the lowest RMSE value. The hybrid method was applied to rainfall datasets obtained from a dense network of 30 stations in Metro Manila which has been collecting meteorological data every 5 minutes since 2012. Implementing the Davis Vantage Pro 2 Plus weather monitoring system, each station sends data to a central server which could be accessed through the website metroweather.com.ph. The stations are spread over approximately 625 sq km of area such that each station is approximately within 25 sq km from each other. The locations of the stations determined by the Metro Manila Development Authority (MMDA) are in critical sections of Metro Manila such as watersheds and flood-prone areas. Three cases have been investigated in this study, one for each type of rainfall present in Metro Manila: monsoon-induced (8/20/13), typhoon (6/29/13), and thunderstorm (7/3/15 & 7/4/15). The area where the rainfall stations are located is divided such that large measured rainfall values are used as part of the boundaries for the SOR. Measured station values found inside the area where SOR is implemented are compared with results from interpolated values. Root mean square error (RMSE) and correlation trends between measured and interpolated results are quantified. Results from typhoon, thunderstorm and monsoon cases show RMSE values ranged from 0.25 to 2.46 mm for typhoons, 1.55 to 10.69 mm for monsoon-induced rain and 0.01 to 6.27 mm for thunderstorms. R2 values, on the other hand, are 0.91, 0.89 and 0.76 for typhoons, monsoon-induced rain and thunderstorms, respectively. This study has shown that the method of approximating rainfall works and can be used in improved prediction, analysis and real time flood map generation.

42 CFR 84.104 - Gas tightness test; minimum requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Section 84.104 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL... times respectively. Walks at 4.8 km. (3 miles) per hour 3 5 3 4 8 12 18 Sampling and readings 2 2 2 2 2 Walks at 4.8 km. (3 miles) per hour 3 5 8 12 18 Sampling and readings 2 2 2 2 2 Walks at 4.8 km. (3...

42 CFR 84.104 - Gas tightness test; minimum requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Section 84.104 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL... times respectively. Walks at 4.8 km. (3 miles) per hour 3 5 3 4 8 12 18 Sampling and readings 2 2 2 2 2 Walks at 4.8 km. (3 miles) per hour 3 5 8 12 18 Sampling and readings 2 2 2 2 2 Walks at 4.8 km. (3...

Ps mantle transition zone imaging beneath the Colorado Rocky Mountains: Evidence for an upwelling hydrous mantle

NASA Astrophysics Data System (ADS)

Zhang, Zhu; Dueker, Kenneth G.; Huang, Hsin-Hua

2018-06-01

We analyze teleseismic P-to-S conversions for high-resolution imaging of the mantle transition zone beneath the Colorado Rocky Mountains using data from a dense PASSCAL seismic broadband deployment. A total of 6,021 P-to-S converted receiver functions are constructed using a multi-channel minimum-phase deconvolution method and migrated using the common converted point technique with the 3-D teleseismic P- and S-wave tomography models of Schmandt and Humphreys (2010). The image finds that the average depths of the 410-km discontinuity (the 410) and 660-km discontinuity (the 660) at 408 ± 1.9 km and 649 ± 1.6 km respectively. The peak-to-peak topography of both discontinuities is 33 km and 27 km respectively. Additionally, prominent negative polarity phases are imaged both above and below the 410. To quantify the mean properties of the low-velocity layers about 410 km, we utilize double gradient layer models parameterization to fit the mean receiver function waveform. This waveform fitting is accomplished as a grid-search using anelastic synthetic seismograms. The best-fitting model reveals that the olivine-wadsleyite phase transformation width is 21 km, which is significantly larger than anhydrous mineral physics prediction (4-10 km) (Smyth and Frost, 2002). The findings of a wide olivine-wadsleyite phase transformation and the negative polarity phases above and below the 410, suggest that the mantle, at least in the 350-450 km depth range, is significantly hydrated. Furthermore, a conspicuous negative polarity phase below the 660 is imaged in high velocity region, we speculate the low velocity layer is due to dehydration flux melting in an area of convective downwelling. Our interpretation of these results, in tandem with the tomographic image of a Farallon slab segment at 800 km beneath the region (Schmandt and Humphreys, 2010), is that hydrous and upwelling mantle contributes to the high-standing Colorado Rocky Mountains.

Recent Seismic Experiments of OBS in the South China Sea

NASA Astrophysics Data System (ADS)

Ruan, A.; Li, J.; Wu, Z.

2012-12-01

Since 2006 some research institutions of China have carried out some important seismic experiments by using ocean bottom seismometer(OBS) in the South China Sea (SCS) and obtained many concrete progresses in modeling the crustal structure of SCS and also in understanding of its formation and evolution as well. In 2006 three wide-angle profiles were completed in the northern margin, named OBS2006-1 across the northwestern sub-basin, OBS2006-2 parallel to the sea basin boundary and OBS2006-3 across the Dongsha Rise and Chaoshan Depression respectively. In 2010 two wide- angle profiles were completed, named OBS2010-1 and OBS 2010-2 both perpendicular to the northern off-shore faulting system. During 2009-2011 four wide-angle profiles were completed in the southern margin, named OBS973-1 from southern margin to the southwestern sub-basin, OBS973-2 from Liyue Bank to the southwestern sub-basin and OBS973-3 from Xisha to the southwestern sub-basin, OBS2011-2 from Xisha to Hainan Island respectively. In 2011 two 3D seismic array of OBS were completed in the Zhongnan-Changlong sea mount chain and Huangyan-Zhenbei sea mount chain respectively. Here we present some primary but important results as follows. (1) The velocity model of OBS2006-1 indicates that the crust under the continental slope decreases from 21km to 11km, and to 7.7km in the northwestern sub-basin with Moho depth ascends from 21km to 11km. The tectonic geometry and velocity structure of the northwestern sub-basin and its margins on both sides shows symmetrical and conjugate and indicates pure shear mode of continental margin rifting mechanism. (2) The velocity model of OBS2006-3 reveals remarkable thickness with maximum 8 km of the Mesozoic sediment in Chaoshan Depression in which velocity increases downward from 4.4 km/s at top to 5.3 km/s at the bottom. The buried depth of Moho decreases from 24-25 km under Dongsha Rise to 17 km in the lower slope and an obviously velocity abnormal is detected in the upper crust of the Dongsha Rise and its velocity raises to 6.9 km/s due to the mantle underplating and magma activities. A high velocity layer (HVL) of 3-12 km thick is found in the lower crust, and its velocity is 7.1-7.4 km/s. (3) The wide angle seismic profile-OBS973-2 that extends in NW-SE direction 369km long from the northeastern Liyue Bank to the central sub-basin. It indicates that there are some small volcanoes on the top of crust in Liyue Bank and P wave velocities downward increase from 5.5~6.4km/s in the upper crust (9~10km thick) to 6.6~7.1km/s in the lower crust (11km thick). In the transition zone and sea basin P wave velocities downward increase from 5.9~6.1km/s in the upper curst (4~5km thick) to 6.6~6.9km/s in the lower crust (2~4km thick). The buried depth of Moho is 23km in Liyue Bank and 8~12km in the sea basin. The comparison of profile OBS973-2 with profile OBS2006-1 in the northern margin shows remarkable similarity between them and suggests a possibility of conjugation relationship between Liyue Bank and Zhongsha Massif. Acknowledgements This work was supported by the National Natural Science Foundation of China (91028006,40876035,41106053 and 41176046) and the National Basic Research Program of China (2007CB411701) .

SAM II aerosol profile measurements, Poker Flat, Alaska; July 16-19, 1979

NASA Technical Reports Server (NTRS)

Mccormick, M. P.; Chu, W. P.; Mcmaster, L. R.; Grams, G. W.; Herman, B. M.; Pepin, T. J.; Russell, P. B.; Swissler, T. J.

1981-01-01

SAM II satellite measurements during the July 1979 Poker Flat mission, yielded an aerosol extinction coefficient of 0.0004/km at 1.0 micron wavelength, in the region of the stratospheric aerosol mixing ratio peak (12-16 km). The stratospheric aerosol optical depth for these data, calculated from the tropopause through 30 km, is approximately 0.001. These results are consistent with the average 1979 summertime values found throughout the Arctic.

A Laccase with Antiproliferative and HIV-I Reverse Transcriptase Inhibitory Activities from the Mycorrhizal Fungus Agaricus placomyces

PubMed Central

Sun, Jian; Chen, Qing-Jun; Cao, Qing-Qin; Wu, Ying-Ying; Xu, Li-Jing; Zhu, Meng-Juan; Ng, Tzi-Bun; Wang, He-Xiang; Zhang, Guo-Qing

2012-01-01

A novel 68 kDa laccase was purified from the mycorrhizal fungus Agaricus placomyces by utilizing a procedure that comprised three successive steps of ion exchange chromatography and gel filtration as the final step. The monomeric enzyme exhibited the N-terminal amino acid sequence of DVIGPQAQVTLANQD, which showed only a low extent of homology to sequences of other fungal laccases. The optimal temperature for A. placomyces laccase was 30°C, and optimal pH values for laccase activity towards the substrates 2,7′-azinobis[3-ethylbenzothiazolone-6-sulfonic acid] diammonium salt (ABTS) and hydroquinone were 5.2 and 6.8, respectively. The laccase displayed, at 30°C and pH 5.2, Km values of 0.392 mM towards hydroquinone and 0.775 mM towards ABTS. It potently suppressed proliferation of MCF 7 human breast cancer cells and Hep G2 hepatoma cells and inhibited human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) activity with an IC50 of 1.8 μM, 1.7 μM, and 1.25 μM, respectively, signifying that it is an antipathogenic protein. PMID:23093860

Evaluation of altimetry-derived surface current products using Lagrangian drifter trajectories in the eastern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Liu, Yonggang; Weisberg, Robert H.; Vignudelli, Stefano; Mitchum, Gary T.

2014-05-01

Lagrangian particle trajectory models based on several altimetry-derived surface current products are used to hindcast the drifter trajectories observed in the eastern Gulf of Mexico during May to August 2010 (the Deepwater Horizon oil spill incident). The performances of the trajectory models are gauged in terms of Lagrangian separation distances (d) and a nondimensional skill score (s), respectively. A series of numerical experiments show that these altimetry-based trajectory models have about the same performance, with a certain improvement by adding surface wind Ekman components, especially over the shelf region. However, their hindcast skills are slightly better than those of the data assimilative numerical model output. After 3 days' simulation the altimetry-based trajectory models have mean d values of 75-83 and 34-42 km (s values of 0.49-0.51 and 0.35-0.43) in the Gulf of Mexico deep water area and on the West Florida Continental Shelf, respectively. These satellite altimetry data products are useful for providing essential information on ocean surface currents of use in water property transports, offshore oil and gas operations, hazardous spill mitigation, search and rescue, etc.

Hydrocarbon gas seeps of the convergent Hikurangi margin, North Island, New Zealand

USGS Publications Warehouse

Kvenvolden, K.A.; Pettinga, J.R.

1989-01-01

Two hydrocarbon gas seeps, located about 13 km apart, have distinctive molecular and isotopic compositions. These seeps occur within separate tectonic melange units of narrow parallel trending and structurally complex zones with incorporated upper Cretaceous and Palaeogene passive continental margin deposits which are now compressively deformed and imbricated along the convergent Hikurangi margin of North Island, New Zealand. At Brookby Station within the Coastal High, the seeping hydrocarbon gas has a methane/ethane ratio of 48 and ??13C and ??D values of methane of -45.7 and -188???, respectively (relative to the PDB and SMOW standards). Within the complex core of the Elsthorpe Anticline at Campbell Station seep, gas has a methane/ethane ratio of about 12000, and the methane has ??13C and ??D values of -37.4 and -170???, respectively. The source of the gases cannot be positively identified, but the gases probably originate from the thermal decomposition of organic matter in tectonically disturbed upper Cretaceous and/or lower Tertiary sedimentary rocks of passive margin affinity and reach the surface by migration along thrust faults associated with tectonic melange. The geochemical differences between the two gases may result from differences in burial depths of similar source sediment. ?? 1989.

2003 AZ84: Size, shape, albedo and first detection of topographic features

NASA Astrophysics Data System (ADS)

Dias-Oliveira, Alex; Sicardy, Bruno; Ortiz, Jose-Luis; Braga-Ribas, Felipe; Vieira-Martins, Roberto; BENEDETTI Rossi, Gustavo; camargo, julio; Assafin, Marcelo; Gomes-Júnior, Altair; Baug, Tapas; Chandrasekhar, Thyagarajan; Duffard, Rene; Ergang, Zhao; Ganesh Ganesh, Shashikiran; Ikari, Yasukazu; Irawati, Puji; Jain, Rajmal; Liying, Zhu; Richichi, Andrea; Shengbang, Qian; Behrend, Raoul; Benkhaldoun, Zouhair; Brosch, Noah; Daassou, Ahmed; Gal-Yam's, Avishay; Garcia-Lozano, Rubén; Gillon, Michael; Jehin, Emmanuel; Kaspi, Shai; Klotz, Alain; Lecacheux, Jean; Mahasena, Putra; Manfroid, Jean; Manulis, Ilan; Maury, Alain; Mohan, Vijay; Morales, Nicolas; Rinner, Claudine; Roques, françoise; Sharma, Amar; Sposetti, Stefano; Tanga, Paolo; Thirouin, Audrey; Vachier, Frederic; Widemann, Thomas

2016-10-01

We analyze two multi-chord stellar occultations by the Trans-Neptunian Object (TNO) 2003 AZ84 observed on February 3, 2012 and November 15, 2014.They provide different elliptical limb fits that are consistent to within their respective error bars, but could also suggest a possible precession of the object (assumed here to be a Maclaurin spheroid). The derived equatorial radius and oblateness are Re = 393 ± 7 km and ɛ = 0.057 in 2014 and Re = 414 ± 13 km and ɛ = 0.165 in 2012, respectively. Those results are consistent with single-chord events observed in January 2011 and December 2013. The figures above provide geometric visual albedos of pV(2014) = 0.112 ± 0.008 and pV(2012) = 0.114 ± 0.020. Using the Maclaurin assumption, combined with possible rotational periods of 6.67 h and 10.56 h, we estimate density upper limits of 1.89 ± 0.16g/cm3 and 0.77 ± 0.07g/cm3 for the two dates, respectively.The 2014 event provides (for the first time during a TNO occultation) a grazing chord with a gradual disappearance of the star behind 2003AZ84's limb that lasts for more than 10 seconds. We rule out the possibility of a localized dust concentration as it would imply very high optical depth for that cloud. We favor a local topographic feature (chasm) with minimum width and depth of 22 ± 2.5 km and 7 ± 2.0 km, respectively. Features with similar depths are in fact observed on Pluto's main satellite, Charon, which has a radius of about 605 km, comparable to that of 2003AZ84.

The velocity ellipsoid in the Galactic disc using Gaia DR1

NASA Astrophysics Data System (ADS)

Anguiano, Borja; Majewski, Steven R.; Freeman, Kenneth C.; Mitschang, Arik W.; Smith, Martin C.

2018-02-01

The stellar velocity ellipsoid of the solar neighbour (d < 200 pc) is re-examined using intermediate-old mono-abundance stellar groups with high-quality chemistry data together with parallaxes and proper motions from Gaia DR1. We find the average velocity dispersion values for the three space velocity components for the thin and thick discs of (σU, σV, σW)thin = (33 ± 4, 28 ± 2, 23 ± 2) and (σU, σV, σW)thick = (57 ± 6, 38 ± 5, 37 ± 4) km s-1, respectively. The mean values of the ratio between the semi-axes of the velocity ellipsoid for the thin disc are found to be σV/σU = 0.70 ± 0.13 and σW/σU is 0.64 ± 0.08, while for the thick disc σV/σU = 0.67 ± 0.11 and σW/σU is 0.66 ± 0.11. Inputting these dispersions into the linear Strömberg relation for the thin disc groups, we find the Sun's velocity with respect to the Local Standard of Rest in Galactic rotation to be V⊙ = 13.9 ± 3.4 km s-1. A relation is found between the vertex deviation and the chemical abundances for the thin disc, ranging from -5 to +40° as iron abundance increases. For the thick disc we find a vertex deviation of luv ˜- 15°. The tilt angle (luw) in the U-W plane for the thin disc groups ranges from -10 to +15°, but there is no evident relation between luw and the mean abundances. However, we find a weak relation for luw as a function of iron abundances and α-elements for most of the groups in the thick disc, where the tilt angle decreases from -5 to -20° when [Fe/H] decreases and [α/Fe] increases. The velocity anisotropy parameter is independent of the chemical group abundances and its value is nearly constant for both discs (β ˜ 0.5), suggesting that the combined disc is dynamically relaxed.

High-level expression of a novel thermostable and mannose-tolerant β-mannosidase from Thermotoga thermarum DSM 5069 in Escherichia coli

PubMed Central

2013-01-01

Background Mannan is one of the primary polysaccharides in hemicellulose and is widely distributed in plants. β-Mannosidase is an important constituent of the mannan-degrading enzyme system and it plays an important role in many industrial applications, such as food, feed and pulp/paper industries as well as the production of second generation bio-fuel. Therefore, the mannose-tolerant β-mannosidase with high catalytic efficiency for bioconversion of mannan has a great potential in the fields as above. Results A β-mannosidase gene (Tth man5) of 1,827 bp was cloned from the extremely thermophilic bacterium Thermotoga thermarum DSM 5069 that encodes a protein containing 608 amino acid residues, and was over-expressed in Escherichia coli BL21 (DE3). The results of phylogenetic analysis, amino acid alignment and biochemical properties indicate that the Tth Man5 is a novel β-mannosidase of glycoside hydrolase family 5. The optimal activity of the Tth Man5 β-mannosidase was obtained at pH 5.5 and 85°C and was stable over a pH range of 5.0 to 8.5 and exhibited 2 h half-life at 90°C. The kinetic parameters Km and Vmax values for p-nitrophenyl-β-D-mannopyranoside and 1,4-β-D-mannan were 4.36±0.5 mM and 227.27±1.59 μmol min-1 mg-1, 58.34±1.75 mg mL-1 and 285.71±10.86 μmol min-1 mg-1, respectively. The kcat/Km values for p-nitrophenyl-β-D-mannopyranoside and 1,4-β-D-mannan were 441.35±0.04 mM-1 s-1 and 41.47±1.58 s-1 mg-1 mL, respectively. It displayed high tolerance to mannose, with a Ki value of approximately 900 mM. Conclusions This work provides a novel and useful β-mannosidase with high mannose tolerance, thermostability and catalytic efficiency, and these characteristics constitute a powerful tool for improving the enzymatic conversion of mannan through synergetic action with other mannan-degrading enzymes. PMID:24099409

Evolving lithospheric flexure and paleotopography of the Pyrenean Orogen from 3D flexural modeling and basin analysis

NASA Astrophysics Data System (ADS)

Curry, M. E.; van der Beek, P.; Huismans, R. S.; Muñoz, J. A.

2017-12-01

The Pyrenees are an asymmetric, doubly-vergent orogen with retro- and pro- foreland basins that preserve a record of deformation since the Mesozoic. The extensive research and exploration efforts on the mountain belt and flanking foreland basins provide an exceptional dataset for investigating geodynamics and surface processes over large spatial and temporal scales in western Europe. We present the results of a numerical modeling study investigating the spatio-temporal variation in lithospheric flexure in response to the developing orogen. We employ a finite element method to model the 3D flexural deformation of the lithosphere beneath the Pyrenean orogen since the onset of convergence in the late Cretaceous. Using subsurface, geophysical, and structural data, we describe the evolving geometry of both the French Aquitaine and Spanish Ebro foreland basins at the present (post-orogenic), the mid-Eocene (peak orogenic), the Paleocene (early orogenic), and the end of the Cretaceous (pre- to early orogenic). The flexural modeling provides insight into how both the rigidity of the lithosphere and the paleotopographic load have varied over the course of orogenesis to shape the basin geometry. We find that the overriding European plate has higher rigidity than the subducting Iberian plate, with modern Effective Elastic Thickness (EET) values of 20 ± 2 and 12 ± 2 km, respectively. Modeling indicates that the modern rigidity of both plates decreases westward towards the Bay of Biscay. The lithospheric rigidity has increased by 50% since the Mesozoic with early Cenozoic EET values of 13 ± 2 and 8 ± 1 km for the European and Iberian plates, respectively. The topographic load began increasing with convergence in the late Cretaceous, reaching modern levels in the central and eastern Pyrenees by the Eocene. In contrast, the topographic load in the western Pyrenees was 70% of the modern value in the Eocene, and experienced topographic growth through the Oligo-Miocene. The westward propagation of topographic growth and erosion is supported by subsidence analysis and low-temperature thermochronology data. These results have implications for surface processes and foreland basin development of the Pyrenean Orogen, inheritance of Hercynian crustal properties, and the geodynamic evolution of western Europe.

Optimized extraction by cetyl trimethyl ammonium bromide reversed micelles of xylose reductase and xylitol dehydrogenase from Candida guilliermondii homogenate.

PubMed

Cortez, Ely Vieira; Pessoa, Adalberto; das Graças de Almeida Felipe, Maria; Roberto, Inês Conceição; Vitolo, Michele

2004-07-25

The intracellular enzymes xylose reductase (XR, EC 1.1.1.21) and xylitol dehydrogenase (XD, EC 1.1.1.9) from Candida guilliermondii, grown in sugar cane bagasse hydrolysate, were separated by reversed micelles of cetyl trimethyl ammonium bromide (CTAB) cationic surfactant. An experimental design was employed to optimize the extraction conditions of both enzymes. Under these conditions (temperature = 5 degree C, hexanol: isooctane proportion = 5% (v/v), 22 %, surfactant concentration = 0.15M, pH = 7.0 and electrical conductivity = 14 mScm(-1)) recovery values of about 100 and 80% were achieved for the enzymes XR and XD, respectively. The purity of XR and XD increased 5.6- and 1.8-fold, respectively. The extraction process caused some structural modifications in the enzymes molecules, as evidenced by the alteration of K(M) values determined before and after extraction, either in regard to the substrate (up 35% for XR and down 48% for XD) or cofactor (down 29% for XR and up 11% for XD). However, the average variation of V(max) values for both enzymes was not higher than 7%, indicating that the modified affinity of enzymes for their respective substrates and cofactors, as consequence of structural modifications suffered by them during the extraction, are compensated in some extension. This study demonstrated that liquid-liquid extraction by CTAB reversed micelles is an efficient process to separate the enzymes XR and XD present in the cell extract, and simultaneously increase the enzymatic activity and the purity of both enzymes produced by C. guilliermondii.

Potential of multispectral synergism for observing tropospheric ozone by combining IR and UV measurements from incoming LEO (EPS-SG) and GEO (MTG) satellite sensors

NASA Astrophysics Data System (ADS)

Costantino, Lorenzo; Cuesta, Juan; Emili, Emanuele; Coman, Adriana; Foret, Gilles; Dufour, Gaëlle; Eremenko, Maxim; Chailleux, Yohann; Beekmann, Matthias; Flaud, Jean-Marie

2017-04-01

Satellite observations offer a great potential for monitoring air quality on daily and global basis. However, measurements from currently in orbit sensors do not allow to probe surface concentrations of gaseous pollutants such as tropospheric ozone (Liu et al., 2010). Using single-band approaches based on spaceborne measurements of either thermal infrared radiance (TIR, Eremenko et al., 2008) or ultraviolet reflectance (UV, Liu et al., 2010) only ozone down to the lower troposphere (3 km) may be observed. A recent multispectral method (referred to as IASI+GOME-2) combining the information of IASI and GOME-2 (both onboard MetOp satellites) spectra, respectively from the TIR and UV, has shown enhanced sensitivity for probing ozone at the lowermost troposphere (LMT, below 3 km of altitude) with maximum sensitivity down to 2.20 km a.s.l. over land, while sensitivity for IASI or GOME-2 only peaks at 3 to 4 km at lowest (Cuesta et al., 2013). Future spatial missions will be launched in the upcoming years on both low and geostationary orbits, such as EPS-SG (EUMETSAT Polar System Second Generation) and MTG (Meteosat Third Generation), carrying respectively IASI-NG (for IR) and UVNS (for UV), and IRS (for IR) and UVN (Sentinel 4, for UV). This new-generation sensors will enhance the capacity to observe ozone pollution and particularly by synergism of multispectral measurements. In this work we develop a pseudo-observation simulator and evaluate the potential of future EPS-SG and MTG satellite observations, through IASI-NG+UVNS and IRS+UVN multispectral methods to observe near-surface O3. The pseudo-real state of atmosphere (nature run) is provided by MOCAGE (MOdèle de Chimie Atmosphérique à Grande Échelle) chemical transport model. Simulations are calibrated by careful comparisons with real data, to ensure the best coherence between pseudo-reality and reality, as well as between the pseudo-observation simulator and existing satellite products. We perform full and accurate forward and inverse radiative transfer calculations for a period of 4 days (8-11 July 2010) over Europe. For what concerns EPS-SG mission results, there is a remarkable agreement in the geographical distribution of LMT ozone partial columns, between IASI-NG+UVNS and the corresponding MOCAGE output. With respect to synthetic IASI+GOME-2 products, IASI-NG+UVNS shows a higher correlation between pseudo-observations and pseudo-reality, enhanced by about 11%. The bias on high ozone retrieval is reduced and the average accuracy increases by 22%. The sensitivity to LMT ozone is enhanced in average with 154% (from 0.29 to 0.75, over land) and 208% (from 0.21 to 0.66, over ocean) higher degrees of freedom. The mean height of maximum sensitivity for the LMT peaks at 1.43 km over land and 2.02 km over ocean, respectively 1.03 km and 1.30 km below that of IASI+GOME-2. IASI-NG+UVNS shows also good retrieval skill in the surface-2km altitude band with a mean DOF (degree of freedom) of 0.52 (land) and 0.42 (ocean), and an average altitude of maximum sensitivity of 1.29 km (land) and 1.96 km (ocean). For what concerns the MTG mission, the strongest gain of IRS+UVN with respect to existing spaceborne sensors will consist in a hourly observation of LMT ozone over Europe, providing O3 products with unprecedented temporal and vertical resolution.

Physical properties and Consolidation behavior of sediments from the N. Japan subduction zone

NASA Astrophysics Data System (ADS)

Valdez, R. D., II; Lauer, R. M.; Ikari, M.; Kitajima, H.; Saffer, D. M.

2013-12-01

Sediment hydraulic properties, consolidation state, and ambient pore pressure development are key parameters that affect fluid migration, deformation, and the slip behavior and mechanical strength of subduction zone megathrusts. In order to better understand the dynamics and mechanisms of large subduction earthquakes, Integrated Oceanic Drilling Program (IODP) Expedition 343, drilled into the toe of the Japan Trench subduction zone in a region of large shallow slip in the M 9.0 Tohoku earthquake, as part of the Japan Trench Fast Drilling Project (J-FAST). Here, we report on two constant rate of strain (CRS) uniaxial consolidation experiments and two triaxial deformation experiments on bedded claystone and clayey mudstone core samples collected from the frontal prism and subducted sediment section cored at Site C0019, 2.5 km landward of the Japan Trench, from depths of 697.18 and 831.45 mbsf. The goals of our experiments were: (1) to define the hydraulic and acoustic properties of sediments that host the subduction megathrust fault that slipped in the M 9.0 Tohoku earthquake; and (2) to constrain in-situ consolidation state and its implications for in-situ stress. The permeability-porosity trends are similar for the two samples, and both exhibit permeability that decreases systematically with increasing effective stress and decreasing porosity, and which varies log-linearly with porosity. Permeabilities of material from the frontal prism decrease from 5×10-18 m2 at 5 MPa effective stress, to 3.0×10-19 m2 at 70 MPa, and porosities decrease from 51% to 29%, while permeabilities of the subducted sediment sample decrease from 5×10-18 m2 at 5 MPa to 3.6×10-19 m2 at 90 MPa, and porosities decrease from 49% to 36%. In-situ permeabilities for the prism and underthrust sediment samples, estimated using laboratory defined permeability-porosity relationships, are 4.9×10-18 m2 and 3.7×10-18 m2, respectively. Elastic wavespeeds increase systematically with increasing effective stress. P-wave velocities (Vp) in the frontal prism sample increase from 2.1 km/s at 8 MPa to 2.7 km/s at 55 MPa effective stress, and velocities in the underthrust sediment sample increase from 2.3 km/s at 6 MPa to 3.0 km/s at 76.5 MPa. Estimated in-situ Vp for the frontal prism and underthrust sediment sample are 2.1 km/s and 2.4 km/s, respectively. This is slightly higher than both the logging while drilling (LWD) measurements and shipboard velocity measurements on discrete samples. We also estimated pre-consolidation pressures (Pc) for each sample using the work-stress method. Comparing Pc with the present day in-situ vertical stress calculated from shipboard bulk density data, we find that both samples are severely overconsolidated. We report this in terms of overconsolidation ratio (OCR), defined as the ratio of Pc to the in-situ stress expected for the case of normal consolidation. Values of OCR for the prism and underthrust samples are 3.95 and 4.28, respectively. This overconsolidation is broadly consistent with fully drained (non-overpressured) conditions, and may reflect uplift and unroofing of the sediments following peak burial greater than their current depth, a significant contribution from lateral tectonic stresses leading to an effective stress far greater than expected for the case of uniaxial burial, or cementation that leads to apparent overconsolidation.

Petrological and Geochemical characterization of central Chihuahua basalts: a possible local sign of rifting activity

NASA Astrophysics Data System (ADS)

Espejel-Garcia, V. V.; Garcia-Rascon, M.; Villalobos-Aragon, A.; Morton-Bermea, O.

2012-12-01

The central part of the mexican state, Chihuahua, is the oriental border of the Sierra Madre Occidental (silicic large igneous province), which consist of series of ignimbrites divided into two volcanic groups of andesites and rhyolites. In the central region of Chihuahua, the volcanic rocks are now part of the Basin and Range, allowing the presence of mafic rocks in the lower areas. The study area is located approximately 200 km to the NW of Chihuahua city near to La Guajolota town, in the Namiquipa County. There are at least 5 outcrops of basalts to the west of the road, named Puerto de Lopez, Malpaises, El Tascate, Quebrada Honda, and Carrizalio, respectively. These outcrops have only been previously described by the Mexican Geologic Survey (SGM) as thin basaltic flows, with vesicles filled with quartz, and phenocrystals of labradorite, andesine, oligoclase and olivine. Petrologically, the basalts present different textures, from small phenocrysts of plagioclase in a very fine matrix to large, zoned and sometimes broken phenocrysts of plagioclase in a coarser matrix. All samples have olivine in an advanced state of alteration, iddingsite. The geochemical analyses report that these basaltic flows contain characteristics of rift basalts. The rocks have a normative olivine values from 5.78 to 27.26 and nepheline values from 0 to 2.34. In the TAS diagram the samples straddle the join between basalt and trachy-basalt, reflecting a high K2O content. The Mg# average is 0.297, a value that suggests that the basalts do not come from a primitive magma. The basalts have high values of Ba (945-1334 ppm), Cu (54-147 ppm), and Zn (123-615 ppm). The contents of Rb (23-57 ppm), Sr (659-810 ppm), Y (26-33 ppm), Zr (148-217 ppm) and Cr (79-98 ppm) are characteristics of rift basalts. Using discrimination diagrams, the basalts plot in the field of within plate, supporting the rifting origin. Outcrops of other basalts, at about 80 to 100 km to the east of the study area, Lomas El Gusano and Rancho El Milagro, report an age of 28.7 ± 0.6 and 28.4 Ma respectively, but it is possible that the basalts of La Guajolota are younger, for being considered as small local eruptions.

Potential air pollutant emission from private vehicles based on vehicle route

NASA Astrophysics Data System (ADS)

Huboyo, H. S.; Handayani, W.; Samadikun, B. P.

2017-06-01

Air emissions related to the transportation sector has been identified as the second largest emitter of ambient air quality in Indonesia. This is due to large numbers of private vehicles commuting within the city as well as inter-city. A questionnaire survey was conducted in Semarang city involving 711 private vehicles consisting of cars and motorcycles. The survey was conducted in random parking lots across the Semarang districts and in vehicle workshops. Based on the parking lot survey, the average distance private cars travelled in kilometers (VKT) was 17,737 km/year. The machine start-up number of cars during weekdays; weekends were on average 5.19 and 3.79 respectively. For motorcycles the average of kilometers travelled was 27,092 km/year. The machine start-up number of motorcycles during weekdays and weekends were on average 5.84 and 3.98, respectively. The vehicle workshop survey showed the average kilometers travelled to be 9,510 km/year for motorcycles, while for private cars the average kilometers travelled was 21,347 km/year. Odometer readings for private cars showed a maximum of 3,046,509 km and a minimum of 700 km. Meanwhile, for motorcycles, odometer readings showed a maximum of 973,164 km and a minimum of roughly 54.24 km. Air pollutant emissions on East-West routes were generally higher than those on South-North routes. Motorcycles contribute significantly to urban air pollution, more so than cars. In this study, traffic congestion and traffic volume contributed much more to air pollution than the impact of fluctuating terrain.

Persistent Longitudinal Variations of Plasma Density and DC Electric Fields in the Low Latitude Ionosphere Observed with Probes on the C/NOFS Satellite

NASA Technical Reports Server (NTRS)

Pfaff, R.; Freudenreich, H.; Klenzing, J.; Rowland, D.; Liebrecht, C.; Bromund, K.; Roddy, P.

2010-01-01

Continuous measurements using in situ probes on consecutive orbits of the C/N0FS satellite reveal that the plasma density is persistently organized by longitude, in both day and night conditions and at all locations within the satellite orbit, defined by its perigee and apogee of 401 km and 867 km, respectively, and its inclination of 13 degrees. Typical variations are a factor of 2 or 3 compared to mean values. Furthermore, simultaneous observations of DC electric fields and their associated E x B drifts in the low latitude ionosphere also reveal that their amplitudes are also strongly organized by longitude in a similar fashion. The drift variations with longitude are particularly pronounced in the meridional component perpendicular to the magnetic field although they are also present in the zonal component as well. The longitudes of the peak meridional drift and density values are significantly out of phase with respect to each other. Time constants for the plasma accumulation at higher altitudes with respect to the vertical drift velocity must be taken into account in order to properly interpret the detailed comparisons of the phase relationship of the plasma density and plasma velocity variations. Although for a given period corresponding to that of several days, typically one longitude region dominates the structuring of the plasma density and plasma drift data, there is also evidence for variations organized about multiple longitudes at the same time. Statistical averages will be shown that suggest a tidal "wave 4" structuring is present in both the plasma drift and plasma density data. We interpret the apparent association of the modulation of the E x B drifts with longitude as well as that of the ambient plasma density as a manifestation of tidal forces at work in the low latitude upper atmosphere. The observations demonstrate how the high duty cycle of the C/NOFS observations and its unique orbit expose fundamental processes at work in the low latitude, inner regions of geospace.

Earth's gravity field mapping requirements and concept. [using a supercooled gravity gradiometer

NASA Technical Reports Server (NTRS)

Vonbun, F. O.; Kahn, W. D.

1981-01-01

A future sensor is considered for mapping the Earth's gravity field to meet future scientific and practical requirements for earth and oceanic dynamics. These are approximately + or - 0.1 to 10 mgal over a block size of about 50 km and over land and an ocean geoid to 1 to 2 cm over a distance of about 50 km. To achieve these values requires a gravity gradiometer with a sensitivity of approximately 10 to the -4 power EU in a circular polar orbiting spacecraft with an orbital altitude ranging 160 km to 180 km.

Modelling trends in tropical column ozone with the UKCA chemistry-climate model

NASA Astrophysics Data System (ADS)

Keeble, James; Bednarz, Ewa; Banerjee, Antara; Abraham, Luke; Harris, Neil; Maycock, Amanda; Pyle, John

2016-04-01

Trends in tropical column ozone under a number of different emissions scenarios are explored with the UM-UKCA coupled chemistry climate model. A transient 1960-2100 simulation was run following the RCP6 scenario. Tropical averaged (10S-10N) total column ozone values decrease from the 1970s, reaching a minimum around 2000, and return to their 1980 values around 2040, consistent with the use and emission of ozone depleting substances, and their later controls under the Montreal Protocol. However, when the total column is subdivided into three partial columns, extending from the surface to the tropopause, the tropopause to 30km, and 30km to 50km, significant differences to the total column trend are seen. Modelled tropospheric column values increase from 1960-2000 before remaining steady throughout the 21st Century. Lower stratospheric column values decrease rapidly from 1960-2000, remain steady until 2050 before slowly decreasing to 2100, never recovering to their 1980s values. Upper stratospheric values decrease from 1960-2000, before rapidly increasing throughout the 21st Century, recovering to 1980s values by ~2020 and are significantly increased above the 1980s values by 2100. Using a series of idealised model simulations with varying concentrations of greenhouse gases and ozone depleting substances, we assess the physical processes driving the partial column response in the troposphere, lower stratosphere and upper stratosphere, and assess how these processes change under different emissions scenarios. Finally, we present a simple, linearised model for predicting tropical column ozone values based on greenhouse gas and ozone depleting substance scenarios.

Application of the [3H]Leucine Incorporation Technique for Quantification of Bacterial Secondary Production Associated with Decaying Wetland Plant Litter

PubMed Central

Gillies, Jane E.; Kuehn, Kevin A.; Francoeur, Steven N.; Neely, Robert K.

2006-01-01

The radiolabeled leucine incorporation technique for quantifying rates of bacterial production has increased in popularity since its original description for bacterioplankton communities. Prior studies addressing incorporation conditions (e.g., substrate saturation) for bacterial communities in other habitats, such as decaying plant litter, have reported a wide range of final leucine concentrations (400 nM to 50 μM) required to achieve saturation-level uptake. We assessed the application of the [3H]leucine incorporation procedure for measuring bacterial production on decaying wetland plant litter. Substrate saturation experiments (nine concentrations, 10 nM to 50 μM final leucine concentration) were conducted on three dates for microbial communities colonizing the submerged litter of three emergent plant species (Typha angustifolia, Schoenoplectus validus, and Phragmites australis). A modified [3H]leucine protocol was developed by coupling previously described incubation and alkaline extraction protocols with microdialysis (500 molecular weight cutoff membrane) of the final radiolabeled protein extract. The incorporation of [3H]leucine into protein exhibited a biphasic saturation curve, with lower apparent Km values ranging from 400 nM to 4.2 μM depending on the plant species studied. Upper apparent Km values ranged from 1.3 to 59 μM. These results suggest differential uptake by litter-associated microbial assemblages, with the lower apparent Km values possibly representing bacterial uptake and higher apparent Km values representing a combination of both bacterial and nonbacterial (e.g., eukaryotic) uptake. PMID:16957215

Catalysis of concerted reactions by antibodies: the Claisen rearrangement.

PubMed Central

Hilvert, D; Carpenter, S H; Nared, K D; Auditor, M T

1988-01-01

Monoclonal antibodies were prepared against a transition state analog inhibitor of chorismate mutase (EC 5.4.99.5). One of the antibodies catalyzes the rearrangement of chorismate to prephenate with rate accelerations of more than 2 orders of magnitude compared to the uncatalyzed reaction. Saturation kinetics were observed, and at 25 degrees C the values of kcat and Km were 1.2 X 10(-3) s-1 and 5.1 X 10(-5) M respectively. The transition state analog was shown to be a competitive inhibitor of the reaction with Ki equal to 0.6 microM. These results demonstrate the feasibility of using rationally designed immunogens to generate antibodies that catalyze concerted reactions. PMID:3393525

A surface brightness correlation between carbon monoxide and nonthermal radio continuum emission in the galaxy

NASA Technical Reports Server (NTRS)

Allen, R. J.

1992-01-01

The relation between the projected face-on velocity-integrated CO (1-0) brightness ICO and the 20 cm nonthermal radio continuum brightness T20 is examined as a function of radius in the Galactic disk. Averaged in 1 kpc annuli, the ratio ICO/T20 is nearly constant with a mean value of 1.51 +/- 0.34 km/s from 2 to 10 kpc. The manner in which ICO and T20 are derived for the Galaxy is different in several significant respects from the more direct observational determinations possible in nearby galaxies. The fact that the Galaxy also follows this correlation further strengthens the generality of the result.

Precise measurement of single-mode fiber lengths using a gain-switched distributed feedback laser with delayed optical feedback.

PubMed

Wada, Kenji; Matsukura, Satoru; Tanaka, Amaka; Matsuyama, Tetsuya; Horinaka, Hiromichi

2015-09-07

A simple method to measure single-mode optical fiber lengths is proposed and demonstrated using a gain-switched 1.55-μm distributed feedback laser without a fast photodetector or an optical interferometer. From the variation in the amplified spontaneous emission noise intensity with respect to the modulation frequency of the gain switching, the optical length of a 1-km single-mode fiber immersed in water is found to be 1471.043915 m ± 33 μm, corresponding to a relative standard deviation of 2.2 × 10(-8). This optical length is an average value over a measurement time of one minute under ordinary laboratory conditions.

Selenium, fluorine, and arsenic in surficial materials of the conterminous United States

USGS Publications Warehouse

Shacklette, Hansford T.; Boerngen, Josephine G.; Keith, John R.

1974-01-01

Concentrations of selenium, fluorine, and arsenic in 912, 911, and 910 samples, respectively, of soils and other regoliths from sites approximately 50 miles (80 km) apart throughout the United States are represented on maps by symbols showing five ranges of values. Histograms of the concentrations of these elements are also given. The geometric-mean concentrations (ppm) in the samples, grouped by area, are as follows: Selenium-- Entire United States, 0.31; Western United States, 0.25; and Eastern United States, 0.39. Fluorine-- Entire United States, 180; Western United States, 250; and Eastern United States, 115. Arsenic-- Entire United States, 5.8; Western United States, 6.1; and Eastern United States, 5.4.

Earth GRAM-99 and Trace Constituents

NASA Technical Reports Server (NTRS)

Justus, C. G.; Duvall, Aleta; Keller, Vernon W.

2004-01-01

Global Reference Atmospheric Model (GRAM-99) is an engineering-level model of Earth's atmosphere. It provides both mean values and perturbations for density, temperature, pressure, and winds, as well as monthly- and geographically-varying trace constituent concentrations. From 0-27 km, GRAM thermodynamics and winds are based on National Oceanic and Atmospheric Administration Global Upper Air Climatic Atlas (GUACA) climatology. Above 120 km, GRAM is based on the NASA Marshall Engineering Thermosphere (MET) model. In the intervening altitude region, GRAM is based on Middle Atmosphere Program (MAP) climatology that also forms the basis of the 1986 COSPAR International Reference Atmosphere (CIRA). Atmospheric composition is represented in GRAM by concentrations of both major and minor species. Above 120 km, MET provides concentration values for N2, O2, Ar, O, He, and H. Below 120 km, species represented also include H2O, O3, N2O, CO, CH4, and CO2. At COSPAR 2002 a comparison was made between GRAM constituents below 120 km and those provided by Naval Research Laboratory (NRL) climatology. No current need to update GRAM constituent climatology in that height range was identified. This report examines GRAM (MET) constituents between 100 and 1000 km altitudes. Discrepancies are noted between GRAM (MET) constituent number densities and mass density or molecular weight. Near 110 km altitude, there is up to about 25% discrepancy between MET number density and mass density (with mass density being valid and number densities requiring adjustment). Near 700 km altitude there is also up to about 25% discrepancy between MET number density and mean molecular weight (with molecular weight requiring adjustment). In neither case are MET mass density estimates invalidated. These discrepancies have been traced to MET subroutines SLV (which affects 90-170 km height range) and SLVH (which affects helium above 440 km altitude). With these discrepancies corrected, results are presented to illustrate GRAM (MET) constituent mole fractions in terms of height-latitude cross sections from 100 to 1000 km altitude, and latitude-longitude 'maps' at 450 km (approximate height of International Space Station). Plans are discussed for an update of MET (and GRAM) to correct these constituent inconsistencies and to incorporate several new thermospheric model features.

System analysis to estimate subsurface flow: from global level to the State of Minnesota

NASA Astrophysics Data System (ADS)

Shmagin, Boris A.; Kanivetsky, Roman

2002-06-01

Stream runoff data globally and in the state of Minnesota were used to estimate subsurface water flow. This system approach is based, in principal, on unity of groundwater and surface water systems, and it is in stark contrast to the traditional deterministic approach based on modeling. In coordination with methodology of system analysis, two levels of study were used to estimate subsurface flow. First, the global stream runoff data were assessed to estimate the temporal-spatial variability of surface water runoff. Factor analysis was used to study the temporal-spatial variability of global runoff for the period from 1918 to 1967. Results of these analysis demonstrate that the variability of global runoff could be represented by seven major components (factor scores) that could be grouped into seven distinct independent grouping from the total of 18 continental slopes on the Earth. Computed variance value in this analysis is 76% and supports such analysis. The global stream runoff for this period is stationary, and is more closely connected with the stream flow of Asia to the Pacific Ocean as well as with the stream runoff of North America towards the Arctic and Pacific Oceans. The second level examines the distribution of river runoff (annual and for February) for various landscapes and the hydrogeological conditions in the State of Minnesota (218,000 km2). The annual and minimal monthly rate of stream runoff for 115 gauging stations with a period of observation of 47 years (1935-1981) were used to characterize the spatio-temporal distribution of stream runoff in Minnesota. Results of this analysis demonstrate that the annual stream runoff rate changes from 6.3, towards 3.95, and then to 2.09 l s-1 km-2 (the difference is significant based on Student's criteria). These values in Minnesota correspond to ecological provinces from a mixed forest province towards the broadleaf forest and to prairie province, respectively. The distribution of minimal monthly stream runoff rate (February runoff) is controlled by hydrogeological systems in Minnesota. The difference between the two hydrogeological regions, Precambrian crystalline basement and Paleozoic artesian basin of 0.83 and 2.09 l/s/km2, is statistically significant. Within these regions, the monthly minimal runoff (0.5 and 1.68, and 0.87 and 3.11 l s-1 km-2 for February, respectively) is also distinctly different for delineated subregions, depending on whether or not the Quaternary cover is present. The spatio-temporal structure that emerges could thus be used to generate river runoff and subsurface flow maps at any scale - from the global level to local detail. Such analysis was carried out in Minnesota with the detailed mapping of the subsurface flow for the Twin Cities Metropolitan area.

System analysis to estimate subsurface flow: From global level to the State of Minnesota

USGS Publications Warehouse

Shmagin, B.A.; Kanivetsky, R.

2002-01-01

Stream runoff data globally and in the state of Minnesota were used to estimate subsurface water flow. This system approach is based, in principal, on unity of groundwater and surface water systems, and it is in stark contrast to the traditional deterministic approach based on modeling. In coordination with methodology of system analysis, two levels of study were used to estimate subsurface flow. First, the global stream runoff data were assessed to estimate the temporal-spatial variability of surface water runoff. Factor analysis was used to study the temporal-spatial variability of global runoff for the period from 1918 to 1967. Results of these analysis demonstrate that the variability of global runoff could be represented by seven major components (factor scores) that could be grouped into seven distinct independent grouping from the total of 18 continental slopes on the Earth. Computed variance value in this analysis is 76% and supports such analysis. The global stream runoff for this period is stationary, and is more closely connected with the stream flow of Asia to the Pacific Ocean as well as with the stream runoff of North America towards the Arctic and Pacific Oceans. The second level examines the distribution of river runoff (annual and for February) for various landscapes and the hydrogeological conditions in the State of Minnesota (218,000 km2). The annual and minimal monthly rate of stream runoff for 115 gauging stations with a period of observation of 47 years (1935-1981) were used to characterize the spatio-temporal distribution of stream runoff in Minnesota. Results of this analysis demonstrate that the annual stream runoff rate changes from 6.3, towards 3.95, and then to 2.09 1 s-1 km-2 (the difference is significant based on Student's criteria). These values in Minnesota correspond to ecological provinces from a mixed forest province towards the broadleaf forest and to prairie province, respectively. The distribution of minimal monthly stream runoff rate (February runoff) is controlled by hydrogeological systems in Minnesota. The difference between the two hydrogeological regions, Precambrian crystalline basement and Paleozoic artesian basin of 0.83 and 2.09 1/s/km2, is statistically significant. Within these regions, the monthly minimal runoff (0.5 and 1.68, and 0.87 and 3.11 1 s-1 km-2 for February, respectively) is also distinctly different for delineated subregions, depending on whether or not the Quaternary cover is present. The spatio-temporal structure that emerges could thus be used to generate river runoff and subsurface flow maps at any scale - from the global level to local detail. Such analysis was carried out in Minnesota with the detailed mapping of the subsurface flow for the Twin Cities Metropolitan area.

MAX-DOAS NO2 observations over Guangzhou, China; ground-based and satellite comparisons

NASA Astrophysics Data System (ADS)

Drosoglou, Theano; Elissavet Koukouli, Maria; Kouremeti, Natalia; Bais, Alkiviadis F.; Zyrichidou, Irene; Balis, Dimitris; van der A, Ronald J.; Xu, Jin; Li, Ang

2018-04-01

In this study, the tropospheric NO2 vertical column density (VCD) over an urban site in Guangzhou megacity in China is investigated by means of MAX-DOAS measurements during a campaign from late March 2015 to mid-March 2016. A MAX-DOAS system was deployed at the Guangzhou Institute of Geochemistry of the Chinese Academy of Sciences and operated there for about 1 year, during the spring and summer months. The tropospheric NO2 VCDs retrieved by the MAX-DOAS are presented and compared with space-borne observations from GOME-2/MetOp-A, GOME-2/MetOp-B and OMI/Aura satellite sensors. The comparisons reveal good agreement between satellite and MAX-DOAS observations over Guangzhou, with correlation coefficients ranging between 0.795 for GOME-2B and 0.996 for OMI. However, the tropospheric NO2 loadings are underestimated by the satellite sensors on average by 25.1, 10.3 and 5.7 %, respectively, for OMI, GOME-2A and GOME-2B. Our results indicate that GOME-2B retrievals are closer to those of the MAX-DOAS instrument due to the lower tropospheric NO2 concentrations during the days with valid GOME-2B observations. In addition, the effect of the main coincidence criteria is investigated, namely the cloud fraction (CF), the distance (d) between the satellite pixel center and the ground-based measurement site, as well as the time period within which the MAX-DOAS data are averaged around the satellite overpass time. The effect of CF and time window criteria is more profound on the selection of OMI overpass data, probably due to its smaller pixel size. The available data pairs are reduced to half and about one-third for CF ≤ 0.3 and CF ≤ 0.2, respectively, while, compared to larger CF thresholds, the correlation coefficient is improved to 0.996 from about 0.86, the slope value is very close to unity ( ˜ 0.98) and the mean satellite underestimation is reduced to about half (from ˜ 7 to ˜ 3.5 × 1015 molecules cm-2). On the other hand, the distance criterion affects mostly GOME-2B data selection, because GOME-2B pixels are quite evenly distributed among the different radii used in the sensitivity test. More specifically, the number of collocations is notably reduced when stricter radius limits are applied, the r value is improved from 0.795 (d ≤ 50 km) to 0.953 (d ≤ 20 km), and the absolute mean bias decreases about 6 times for d ≤ 30 km compared to the reference case (d ≤ 50 km).

Correlation of new hypervelocity impact data by threshold penetration relations

NASA Technical Reports Server (NTRS)

Hayduk, R. J.; Gough, P. S.; Alfaro-Bou, E.

1973-01-01

Threshold penetration data are established by impacting spherical projectiles onto 2024 aluminum single-wall targets. Nylon and cadmium projectiles were used at impacting velocities from 3.0 to 6.8 km/s and 7.9 to 8.5 km/s respectively. These data are combined with existing data and compared with three threshold relations to assess their respective validities over a wide range of projectile densities. Two of these relations were validated over the extended range of projectile densities.